Auto- and cross-correlation analysis of subthalamic nucleus neuronal activity in neostriatal- and globus pallidal-lesioned rats. Statistical analyses (autocorrelation and first-order interstimulus interval) were conducted on the spontaneous activity of over 420 subthalamic neurons recorded in 5 groups (control, large globus pallidus kainic acid lesion, partial globus pallidus kainic acid lesion, partial globus pallidus ibotenic acid lesion and neostriatal lesion) of anesthetized rats. Cross-correlation and peristimulus time histogram (to frontal motor cortex stimulation at 0.7 mA) analyses were conducted on pairs (n = 58) of subthalamic neurons recorded simultaneously on a single microelectrode. Lesion of the globus pallidus increased spontaneous firing rate as compared to controls and shifted the pattern of spontaneous activity from either a regular or irregular pattern to a markedly bursting pattern. Neostriatal lesion reduced firing rate and reduced the likelihood of highly regular firing. In control, neostriatal and partial lesioned animals, approximately 1 in 3 pairs of neurons showed correlated firing. The correlations were joint increased probabilities of firing over intervals of 200-400 ms, suggesting a shared excitatory input. No short-interval (less than 10 ms) correlations were seen. Large globus pallidus lesion increased the likelihood of correlated firing (12 of 16 pairs). In all groups of animals the peristimulus time histograms (PSTHs) to motor cortex stimulation were more similar than would be expected by chance and pairs of neurons showed the same increases in response following globus pallidus lesion. Thus adjacent neurons share common cortical inputs and responsiveness to those inputs. These changes indicate that the globus pallidus influences the spontaneous firing rate and pattern of subthalamic neurons as well as the degree of correlated firing of adjacent neurons.


Biochemical characterization of independent olfactory receptor sites for 5'-AMP and taurine in the spiny lobster. To understand the initial events in chemosensory transduction (i.e. binding of odorants to olfactory receptor sites), we have utilized a radioligand-receptor binding assay on a tissue preparation that is enriched in dendritic membrane from olfactory receptor cells in the spiny lobster Panulirus argus. Radioligands used were tritiated adenosine 5'-monophosphate (AMP) and taurine, which are two of the most excitatory compounds for spiny lobsters. Our results indicate the existence of two independent types of binding sites--a taurine binding site and an AMP binding site. For both the taurine and AMP binding sites, odorant binding is rapid, reversible, and saturable. KD values for the taurine and AMP binding sites are 2.3 and 2.0 microM, respectively, and Bmax values are 159 and 3.2 fmol/micrograms protein, respectively. The fact that the specificity, affinity, and independence of these two binding sites as defined in these biochemical studies are in agreement with those from electrophysiological studies suggests that these binding sites are olfactory receptor sites involved in sensory transduction.


Symmetric synapses formed by callosal afferents in rat visual cortex. Following an electron microscopic examination of 437 degenerating terminals of callosally projecting axons in layer II/III at the 17/18a border, it has been found that some of these terminals form symmetric synapses with dendritic shafts (1.83%), pyramidal cell bodies (1.37%) and dendritic spines (0.46%). The remainder of the axon terminals (96.33%) form asymmetric synapses, mainly with dendritic spines although a few form synapses with dendrites. These results suggest that in the rat visual cortex the corpus callosum is a source of both inhibitory and excitatory input to the contralateral hemisphere.


Ultrastructural immunolocalization of rat oxytocin-neurophysin in transgenic mice expressing the rat oxytocin gene. Cell-specific expression of the rat oxytocin (OT)-neurophysin transgene in mice was achieved using a construct containing both OT and vasopressin genes (Young III, W.S., Reynolds, K., Shepard, E.A., Gainer, H. and Castel, M., Cell-specific expression of the rat oxytocin gene in transgenic mice, J. Neuroendocrinol., 2 (1990) 1-9). The present study describes the distribution of the protein products of these genes in various regions of the cell, and determines whether the transgenic rat and endogenous mouse OT-neurophysins are colocalized within the same neurosecretory granules. Two monoclonal antibodies against OT-neurophysins were used: PS38 which can react with both rat and mouse OT-neurophysin (pan-specific), and PS67 which is specific for rat OT-neurophysin only. Various approaches to double immunolabeling at the ultrastructural level were employed; these included: (1) pre-embedding immunoperoxidase followed by post-embedding immunogold; (2) post-embedding immunolabeling using gold particles of different sizes; and (3) labeling of consecutive ultrathin sections with different antibodies. Results from each of these approaches showed that both in the transgenic mouse and in the rat (used as control), immunocytochemical labeling for both PS38 and PS67 occurred in the same OT-ergic neurosecretory granules. In the control mouse, only PS38 elicited labeling. Hence, it may be concluded that the protein and peptide products of the transgene and the endogenous gene for OT-neurophysin are being processed similarly in the cell and finally concentrated together in the same neurosecretory granules.


Further studies on interactions between periaqueductal gray, nucleus accumbens and habenula in antinociception. Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop.


TNF alpha induces IL-6 production by astrocytes but not by microglia. Astrocytes and microglia, both produced interleukin-6 (IL-6) in culture by lipopolysaccharide (LPS) stimulation. IL-6 activity was detected 3-5 h after LPS stimulation and reached a maximum at 10 h. Microglia responded faster than astrocytes. Tumor necrosis factor alpha and interleukin 1 also induced IL-6 mRNA and biological activity in astrocytes, but not in microglia. Among these stimuli, LPS was the most potent inducer of IL-6 production by astrocytes. Our results suggest that different regulatory mechanisms for cytokine production exist in glial cells. The possible roles of astrocytes and microglia in CNS immune responses are also discussed.


Neurochemical effects of vagus nerve stimulation in humans. An implanted stimulating device chronically stimulated the left cervical vagus nerve in epileptic patients. Cerebrospinal fluid concentrations of free and total gamma-aminobutyric acid, homovanillic acid, 5-hydroxyindoleacetic acid, aspartate, glutamate, asparagine, serine, glutamine, glycine, phosphoethanolamine, taurine, alanine, tyrosine, ethanolamine, valine, phenylalanine, isoleucine, vasoactive intestinal peptide, beta-endorphin, and somatostatin were measured before and after 2 months of chronic stimulation in six patients. Significant increases were seen in homovanillic acid and 5-hydroxyindoleacetic acid in three patients, and significant decreases in aspartate were seen in five patients. These changes were associated with a decrease in seizure frequency.


Effect of age on [3H]nisoxetine binding to uptake sites for norepinephrine in the locus coeruleus of humans. [3H]Nisoxetine ([3H]NIS) was used to measure uptake sites for norepinephrine (NE) in the locus coeruleus (LC) of humans. Regression analysis demonstrated an inverse correlation between age and the binding of [3H]NIS to NE uptake sites in the LC (r = -0.6; P less than 0.01). Since considerable cell loss has been reported to occur with age in the human LC, the decreased binding of [3H]NIS probably reflects loss of LC cells rather than a down-regulation of these sites.


Olfactory bulb output neurons excited from a basal forebrain magnocellular nucleus. We present intracellular data which demonstrates a unique facilitatory centrifugal influence on the output cells of the olfactory bulb; the source being the lateral component of the nucleus of the horizontal limb of the diagonal band (HDB), part of the basal forebrain magnocellular complex. Damage to this facilitatory HDB influence may explain the loss of olfactory sensitivity seen early in Alzheimer's disease in which pathological changes occur in the basal forebrain.


Involvement of hypothalamic noradrenergic systems in the modulation of intestinal motility in rats. Selective lesions of the noradrenergic systems of the paraventricular nucleus (PVN) of the hypothalamus with 6-hydroxydopamine (6-OHDA) lengthen the periodicity of the migrating myoelectric complex (MMC), an index of intestinal motility, in rats. These lengthening effects resemble those obtained after lesions of the locus coeruleus (LC), thus suggesting that noradrenergic terminals from LC to the PVN are involved in this modulation.


A double-label study demonstrating that all serotonin-like immunoreactive amacrine cells in the larval tiger salamander retina express GABA-like immunoreactivity. A previous study localized serotonin-like immunoreactivity to amacrine cell populations in the larval tiger salamander retina. The present double-label immunocytochemical analysis of the tiger salamander retina was performed to determine if gamma-aminobutyric acid (GABA)-like immunoreactivity is expressed by serotonin-immunoreactive amacrine cells. More than 3,000 serotonin-amacrine cells were observed in double-label preparations, and all were found to express GABA-like immunoreactivity. This finding extends previous studies of serotonin-GABA coexistence in the retina by providing the first report of the co-localization of endogenous serotonin and GABA-like compounds in a retinal neuron.


Identification of an AII(3-8) [AIV] binding site in guinea pig hippocampus. A unique angiotensin binding site specific for the hexapeptide, AII(3-8), has been identified in guinea pig hippocampus. This binding site, which is present in the pyramidal cell layer of CA1, CA2, CA3 of the hippocampus and dentate gyrus, binds AII(3-8) with high affinity (KD = 1.29 +/- 0.18 nM) in a saturable manner (Bmax = 449 +/- 62 fmol/mg protein). The N-terminal structure of the binding ligand is paramount in determining the binding affinity. The C-terminal requirements seem less stringent as evidenced by the binding affinity of AII(3-7) (KD = 20.9 +/- 2.1 nM). Neither AII, AIII,Sar1, Ile8-AII, Dup 753 nor CGP42112A appear to bind, indicating that this binding site is neither the AT1 nor AT2 sites described for AII/AIII. Autoradiographic analysis of hippocampus binding confirms the inability of Sar1,Ile8-AII to compete for [125I]AII(3-8) binding. Conversely AII(3-8) was unable to displace [125I]Sar1,Ile8-AII binding.


The magnocellular arginine-vasopressin mRNA responds differently to food deprivation between the supraoptic and paraventricular nuclei of the hypothalamus in adrenalectomized rats with low corticosterone replacement. We previously reported that food deprivation significantly decreased arginine-vasopressin (AVP) mRNA levels in the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus and also greatly stimulated the pituitary-adrenocortical system in rats. In this study, we deprived adrenalectomized rats with subcutaneously implanted low-dose corticosterone pellets (ADX + B) of food for 3 days to investigate the involvement of corticosteroid feedback regulation in the food deprivation-induced decrease in AVP mRNA in both the SON and the PVN. The plasma corticosterone levels in these animals were maintained at low levels constantly over 24 h. The ACTH concentration in the morning plasma was markedly increased in the food-deprived ADX + B rats as compared to the fed ADX + B rats. Food deprivation significantly decreased the corticotropin-releasing hormone (CRH) content in the median eminence and increased the CRH and AVP content in the neurointermediate lobe of the pituitary. Semiquantitative in situ hybridization histochemistry revealed that AVP mRNA levels were decreased in the SON but, inversely, increased in magnocellular as well as parvocellular subdivisions of the PVN following food deprivation. These results suggest that: (1) AVP mRNA responds differently to food deprivation between the SON and the PVN; (2) the glucocorticoid feedback can exert on AVP mRNA in the PVN but not in the SON in the food-deprived rats; and (3) food deprivation affects the neurohypophysial levels of CRH and AVP.


Effects of inorganic constituents of saliva on taste responses of the rat chorda tympani nerve. The effects of saliva on the taste responses of the chorda tympani nerve to the 4 standard chemical stimuli (sucrose, NaCl, HCl, and quinine hydrochloride) and water were investigated in anesthetized rats. When the tongue was adapted to pilocarpine-stimulated whole saliva (pH 8.7), the magnitude of neural response to sucrose was about 2 times that obtained when the tongue was adapted to distilled water. Under saliva-adapted conditions, the magnitude of responses to other taste stimuli was reduced by 10-30%, and the water response appeared. These changes were dependent on the concentration of electrolytes (Na+, K+, Cl-, and HCO3-) and on the pH of the saliva. When the tongue was adapted to 10-30 mM NaHCO3 (pH 8.4-8.6), taste and water responses were similar to those under saliva-adapted conditions. Single fiber analyses revealed that the enhancement of the sucrose response after adaptation to NaHCO3 was produced by an increased overall activity of sucrose-responsive fibers. The correlation coefficients of the magnitude of the taste responses between the 4 taste stimuli remained unchanged, but the water response showed a high correlation to HCl and quinine hydrochloride responses after adaptation. Possible mechanisms for the effects of saliva on taste and water responses were discussed.


Frequency selectivity is related to temporal processing in parallel thalamocortical auditory pathways. Lemniscal and non-lemniscal parallel thalamocortical auditory pathways have been identified with the ventral medial geniculate body (MGB) vs. the dorsal and medial MGB, respectively. Lemniscal neurons have narrow frequency tuning and provide highly specific frequency information to the auditory cortex whereas non-lemniscal neurons generally have broader tuning and greater response lability, including plasticity of frequency receptive fields during learning. To determine if frequency selectivity is related to temporal fidelity of response, we measured both the breadth of tuning and neuronal excitability in a paired tone paradigm for single neurons throughout the MGB. Excitability to the second tone of a pair was directly correlated with frequency selectivity: the narrower the frequency tuning, the greater the excitability. Cells with broad tuning based on multiple-peak response areas also were less excitable than cells with single-peak RAs. Cells in the ventral MGB showed greater temporal fidelity of response (greater excitability) than cells in the dorsal and medial MGB. These findings show that high degrees of both frequency selectivity and temporal response fidelity are characteristic of the lemniscal, but not the non-lemniscal, thalamocortical auditory system.


Hippocampal cholinergic alterations and related behavioral deficits after early exposure to phenobarbital. Mice were exposed to phenobarbital (PhB) prenatally and neonatally. Prenatal exposure was accomplished by feeding the mother PhB (3 g/kg milled food) on gestation days 9-18. Neonatal exposure was accomplished by daily injections of 50 mg/kg sodium PhB directly to the pups on days 2-21. Long-term biochemical alterations in the pre- and postsynaptic septohippocampal system, as well as related behavioral deficits, were assessed in the treated animals. Significant increase in B(max) values for binding of [3H]QNB to muscarinic cholinergic receptors was obtained on both ages 22 and 50 in prenatally (40-90%, respectively, p less than 0.001) and neonatally exposed (58-89%, p less than 0.001) mice whereas Kd remained normal. Similarly, a significant increase of inositol phosphate (IP) formation in response to carbachol was found after both prenatal and neonatal exposure to PhB (p less than 0.05). No alterations in choline acetyltransferase (ChAT) activity were observed in the prenatally or neonatally treated animals. The early exposed mice showed deficits in the performance in Morris water maze, a behavior related to the septohippocampal pathway. The results suggest that early exposure to PhB induces alterations in postsynaptic components of the hippocampal cholinergic system and concomitantly to impairment in hippocampus-related behavior.


Neural circuit computation: complex patterns in the olfactory bulb. The olfactory bulb principal neurons show complex responses during olfactory stimulation that are characterized by periods of profound suppression, temporal patterns of activity, and nonmonotonic intensity response functions. The model presented here suggests that these features may arise from changing spatial patterns of activity across the bulbar surface due to restricted (chemotopic) activation in bulbar glomeruli. The model is based on a simplified version of the bulbar neural circuit as it is presently known from anatomical and physiological investigations and provides explanations for several anomalous bulbar response patterns.


Facilitation of sexual behavior shortly after electrolytic lesion of the medial preoptic area: what does it mean? To analyze the behavioral effects of an unphysiological manipulation of the medial preoptic area (MPOA), sexually experienced male rats received small bilateral electrolytic lesions within this area. Thirty-five percent of the lesioned animals showed a drastic facilitation of sexual behavior when tested 3 h after lesion. The number of intromissions, ejaculation latency, and postejaculatory interval were drastically reduced. The mean number of ejaculations was significantly higher in lesioned animals that displayed the behavior in comparison both to an intact group and a sham-lesioned group. Neither the size of the lesion nor its exact location could be correlated with the facilitation of sexual behavior. However, animals that showed facilitation tended to have the lesion located in the ventral part of the MPOA. Lesions rostral or dorsal to the MPOA were ineffective. It is suggested that the small electrolytic lesions in the MPOA produced iron deposits that stimulated the remaining intact preoptic region, resulting in the drastic facilitation of sexual behavior. The results of the present study support the hypothesis suggesting that the MPOA is involved in the mechanisms related to the initiation and execution of sexual behavior.


Coexistence of autonomic and somatic mechanisms in the pressor areas of medulla in cats. The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes.


Hypothalamic neuronal responses to interleukin-6 in tissue slices: effects of indomethacin and naloxone. We recently reported that human recombinant interleukin-6 (hrIL-6) microinjected into the preoptic area (POA) of guinea pigs induced fever at high doses, suggesting that IL-6 may be another endogenous pyrogen. This study was undertaken to determine whether hrIL-6 affects the single-unit activity of thermosensitive and thermally insensitive neurons in hypothalamic tissue slices and whether indomethacin (Indo) or naloxone (Nal), a cyclooxygenase inhibitor and a mu-opioid receptor antagonist, respectively, influences the effects of hrIL-6 on those neurons. hrIL-6 (2 x 10(3)-8 x 10(3) U/ml) depressed the activity in 50 (83%) of 60 warm-sensitive (W) neurons and excited all 4 cold-sensitive (C) neurons found. It had no effect, however, on 14 (48%) of 29 thermally insensitive (I) neurons, albeit 7 and 8 I neurons decreased and increased their firing rates, respectively. Indo (0.05-1 mg/ml) blocked the effect of hrIL-6 on 22 of 24 W neurons and 2 C neurons tested. Nal(0.1-1 mg/ml) blocked or reduced the effect of hrIL-6 on 21 of 25 W neurons and 1 C neuron recorded. These drugs induced no neuronal response per se. Nal at 2-5 mg/ml, which increased the activity of four W neurons by itself, reversed their depressed response to hrIL-6. These results support the possibility that IL-6-induced fevers may be mediated through an effect on thermosensitive neurons in the POA and that opioids and prostaglandin E may both be involved in this process.


Elevated content and secretion of gut GLI in VMH-lesioned rats. Gut glucagon-like immunoreactivity (GLI), a supposed intestinal growth factor in the plasma and gastrointestinal tract, and weight of the gastrointestinal tract, an intestinal growth indicator, were examined in ventromedial hypothalamic (VMH)-lesioned rats 1 week after VMH lesions. Postprandial plasma gut GLI in VMH-lesioned rats was significantly higher than that in control rats. The content of gut GLI in all gastrointestinal sections except the duodenum in VMH-lesioned rats was significantly greater than that in control rats. Gel chromatography in the lower portion of the small intestine in which GLI content was the highest of all sections revealed the same pattern in both VMH-lesioned and control rats with two peaks of similar molecular size. Weight of all gastrointestinal sections except the cecum in VMH-lesioned rats significantly increased. These results demonstrated that both gut GLI secretion and production were enhanced in VMH-lesioned rats. The elevated gut GLI release may accelerate growth of the gastrointestinal tract in these animals.


Airflow receptors in the lip and buccal mucosa. Airflow receptor afferents in the oral mucosa responding to changes in intraoral air pressure during blowing were found to be innervated by the infraorbital nerve. They provided one response corresponding to the onset of blowing, a second related to an increase in air pressure, a third corresponding to the cessation of blowing, and a fourth that exhibited little change throughout sustained blowing. Intraoral air pressure in the cavity between the lips and the velopharyngeal portal may be monitored by these receptors, and the data they provide may contribute to the control of phonation.


Intracerebroventricular LHRH relieves behavioral deficits due to vomeronasal organ removal. Contact between the sexes in many species is known to produce hormonal changes in the male [increases in serum luteinizing hormone (LH) and/or testosterone] that can be interpreted as due to an intracerebral release of LH-releasing hormone (LHRH). In some circumstances, these hormonal changes appear to depend on an intact vomeronasal sensory system. Exogenous LHRH is also known to facilitate mating behavior in several species. We show here that LHRH delivered into the cerebral ventricles can restore some mating behavior lost when the vomeronasal organs are removed from sexually inexperienced male hamsters. The results are consistent with our working hypothesis that intracerebral LHRH release is an intermediate in the facilitation of mating behavior by vomeronasal sensory input.


Implantation of genetically modified mesencephalic fetal cells into the rat striatum. Transplantation of dopamine (DA) cells into the rat model of hemiparkinsonism induced by intranigral 6-hydroxydopamine (6-OHDA) injections has so far focused mainly on DA replacement via a pump-like mechanism. In the present study, we employed a model of hemiparkinsonism that uses an intrastriatal approach to lesioning the nigrostriatal DA pathway to assess the possibility of using cell transplantation to cause regeneration of that system. Toward that end, we transplanted two types of cells on the side of the 6-OHDA-induced lesions: 1) nonmodified fetal mesencephalic cells and 2) fetal mesencephalic cells that have been infected with a retrovirus vector containing a PKC beta 1 cDNA. Both types of cells cause behavioral improvement although the changes were more prominent and occurred earlier in the PKC-modified groups. Tyrosine hydroxylase (TH) immunocytochemistry revealed significantly cell survival in both groups of animals; in situ hybridization studies confirmed the continuous expression of TH mRNA in both groups. Interestingly, long TH-positive axons were observed only in the striata of animals implanted with PKC-modified cells. More importantly, surviving endogenous nigral TH-positive cell bodies were found only on the lesioned side in the latter group. The observations in these animals were associated with significantly smaller decreases in [3H]mazindol-labeled DA uptake sites in both the striata and substantia nigra pars compacta on the side ipsilateral to the 6-OHDA-induced lesions. Furthermore, immunohistochemical studies revealed increased gliosis in the striata of animals grafted with the PKC-modified cells. When taken together, these results indicate that transplantation of normal fetal mesencephalic cells can cause behavioral improvement by providing DA to the host striata whereas PKC-modified cells can, in addition, prevent the progressive degeneration of or cause regeneration of the dying nigrostriatal DA neurons in this model of hemiparkinsonism. These results are discussed in terms of their support for a role for second messenger systems and glial cells, as well as extracellular matrix molecules in the regeneration of the CNS.


Subnuclear organization of the human caudal nucleus of the solitary tract. The caudal human nucleus of the solitary tract (NTS) is composed of 10 subnuclei. The commissural subnucleus spans the midline below the obex, merging rostrally into the medial subnucleus. The other subnuclei of the NTS are best seen just above the obex. The ventrolateral subnucleus contains large, darkly staining neurons. The interstitial subnucleus consists of neurons lying in groups intermingled with the fibers of the tract. The lateral subnucleus is small at caudal levels, merging with the interstitial subnucleus more rostrally. The dorsal subnucleus contains large melanotic neurons and encircles the substantia gelatinosus, a round, cell-poor subnucleus. The ventromedial subnucleus curls around the medial and ventral edge of the tract. The intermediate subnucleus, laying ventrolateral to the dorsal motor nucleus of the vagus, also contains melanotic neurons. The subpostremal subnucleus separates the area postrema from the NTS proper. The medial subnucleus is the largest subnucleus in the caudal NTS, containing medium-sized fusiform neurons. Adoption of a uniform cytoarchitectural map of the caudal NTS will permit more accurate comparisons between human and nonhuman studies.


[Rupture of abdominal aorta aneurysms. Study of 92 cases operated on over a ten year period (1980-1989)]. From January 1980 to December 1989, 92 ruptured abdominal aortic aneurysms (AAA) were operated upon in emergency at our institution. During the same period, 747 AAA were operated in election or in the absence of rupture. The mean age of patients was 72.8 +/- 9.1 (52-95). There were 81 men and 11 women. Etiology of the AAA was common degenerative in all cases except in one case of aortic dissection and one case of infectious aneurysm. 27 (29.3%) patients presented antecedents of bronchopathy, 31 (33.7%) antecedents of hypertension and 36 (39.1%) antecedents of coronary heart disease. All patients were operated upon under general anesthesia, in two (2.1%) cases through a thoraco-abdominal exposure, in one case through a lombotomy, in one case, using exclusion and an extra anatomic bypass and through a midline transperitoneal laparotomy in all 88 (96.9%) other cases. The mean diameter of the AAA was 9 +/- 3.9 (4-25) cm. The rupture was intra-peritoneal in 26 (28.3%) cases, intra caval in 5 (5.4%) cases, intra duodenal in 2 (2.2%) cases and retro peritoneal in all the other 59 (64.1%) cases. The aorta was cross clamped above the renal arteries in 15 (16.3%) cases, under the renal arteries in 48 (52.2%) cases and at both levels in 29 (31.5%) cases. Surgical treatment consisted in an aorto-aortic tubular graft in 45 (48.9%) cases, a bifurcated aortic graft in 32 (34.8%) cases, an exclusion with extra anatomic bypass in one (1%) case and could not be completed before the death of the patient in 14 (15.3%) cases. There were 56 (60.9%) deaths, 27 (29.4%) in the per operative and 29 (31.5%) in the post operative periods after a mean time of 5.7 +/- 9.2 (0-36) days. The cause of the death was hemorrhage in 25 (44.4) cases, cardiac complications in 28 (50%) cases, renal insufficiency in 1 (2%) case, pulmonary complications in 1 (2%) case and septic complications in one (2%) case. During the period of the present study, rupture of an AAA remained, in our institution as in other institutions an often fatal condition. This condition could probably be avoided with a policy of early detection and surgical treatment.


[Human placental implantation].

[Human placental implantation]. Like malignant tumor cells, cells of the trophoblast, of the blastocyst and of the hemochorial placenta are highly invasive. This invasiveness is essential for implantation and penetration of the epithelial and connective tissues of the endometrium. According to Hertig's data and the observations (henceforth classical) of the Carnegie Foundation, it is commonly admitted that trophoblastic cells penetrate rapidly the blood vessels of the maternal endometrium, open them and allow the establishment of a communication between maternal circulation and fetal tissues from the 20th day after fertilization. As suggested in the classical textbooks of Embryology, the hemochorial placentation would be established very early in human pregnancy. These observations (essentially histological) are actually contradicted by clinical observations performed by Doppler contact echography and by dynamic observations with a microvideo camera implanted in the intervillous placental chamber. Echographic observations coupled with the study of Doppler signals suggest the absence of placental maternal vascularization during the first trimester of pregnancy. It is possible to mount an optical system between the membranes and the uterine wall up to the placental tissue to observe the placental circulation. This direct observation concludes to the absence of maternal vascularization in the intervillous chamber during the first trimester of pregnancy. At the beginning of the 13th week of gestation, uterine arteries open directly into the intervillous chamber ensuring the direct perfusion of placental villi. These informations allow to suggest that the placenta becomes hemochorial at the beginning of the second trimester of pregnancy.


[Coronary disease in black Africans: epidemiology, risk factors, clinical symptomatology and coronarography, evolution]. The study of the epidemiological data (published since 1952) seems to show an increasing frequency of the coronary disease for 15 last years. But this incidence seems to reach a stable level about 6 to 7% of the cardiovascular diseases at the Abidjan Institute of Cardiology; and 3.17% in a study in 13 countries but without coronarography (except at the Abidjan Institute). The study of the risk factors show that they are the same ones than in Europa. The risk index in Black Africa was 2.1 to 2.7 risk factor patient. These numbers are lesser than the risk index noted in France (3.6 in coronary patients and 1.9 in non-coronary subjects). The signs of the disease show that myocardial infarctions were frequent (48.8%) and often were the first manifestations of the coronary disease (40%). Angina pectoris was observed in 32.2%, an ischemic cardiomyopathy in 6.6% and a ventricular aneurysm in 6.6%. A silent ischemia was observed in 5.5% among at risk diabetic patients. The in-hospital mortality after myocardial infarction was 15% and was the same in European and African patients. But the mortality in Africans was greater than in Europeans the next years. Coronarography showed that 18.8% of the patients with coronary disease had normal coronary arteries. The arteries were also normal in 19.9% of the patients examined after an infarction. These high percentages can be related to coronary arterial spasms or to recanalized thrombosis. A spontaneous spasm was observed in 6.6% of the patients (a provoked coronary arterial spasm was not studied. The coronary arterial lesion was an one artery disease in 38.8% of the coronary patients and 50% of the patients with infarction. The stenosis were frequently proximal (82.6%) and the anterior descending artery was interested in 45.6%. Ventricular aneurysms were observed in 56.6% and the ejection fraction was lower than 0.50 in 63.3%. These data permit to compare the myocardial infarction of Blacks with the myocardial infarction of the young occidental men. We can think that thrombolysis or angioplasty would be very useful but they are often impossible in the Black African conditions.


[Intraluminal transport of vitamin B12]. Since the existence of vitamin B12 was suggested by Castle in the first few decades of this century, vitamin B12 has been the subject of many studies which have proved the high complexity of it assimilation by the organism. Over the last few years the marked progress in functional digestive exploration methods and the physical and the chemical characteristics of biological molecules have revived the established idea of the vitamin's intraluminal transit. Our recent studies have been concentrated on the bilioduodenopancreatic stage of the vitamin B12 transport. In nature, vitamin B12 is only exceptionally met in its free form it is always associated with a binder. Like a ball being tossed from one player to another, it moves between binders. Alimentary vitamin B12 released from its protein complexes by culinary preparation and gastric secretions, is combined with haptocorrin. Around the duodenum the transfer of B12 on intrinsic factor is due to partial degradation of haptocorrin by pancreatic enzymes and intraluminal pH balance. This combined with intrinsic factor the vitamin can be caught by the ileal receptor. The partial degradation haptocorrin joins vitamin B12 analogs from excreted bile or synthesized by the intestinal microorganisms.


[Analytic study of noise].

[Analytic study of noise]. This analysis examines the definition, origin, category, acoustic and psycho-acoustic properties and the quantitative and qualitative measurements of noise, allowing one to delineate the problems associated with such a disturbance. There are several definitions of sound, depending on the angle at which one considers the phenomenon: social, acoustic, psycho-acoustic or medical. The acoustic aspect determines its physical characteristics; the psycho-acoustic aspect deals specifically with its effect on the human ear. Noise assumes very different aspects: ambient, stable, fluctuating, intermittent, pulsing. It presents a disturbance depending on different factors: intensity, frequency, length of exposure, mode of arrival, evolution in time, acoustic characteristics. Over and above all these is added a factor of personal sensitivity, varying from one individual to another. Measurement of noise is performed with the help of an instrument called a sonometer, which records the level of the acoustic pressure, i.e. intensity. From this point, one can evaluate the magnitude of auditive disturbance, Leq. Measurement of human hearing has also been established. This is called audiometry. It allows one to assess the auditive value by drawing a graph: the audiogram. AFNOR has established a classification of noises to be found related to social life. Two broad categories: indoor noises, related to the activity in an apartment building and within the lives of its inhabitants, and outdoor noises, linked to traffic noise and its different forms, and to economic and social activity and noise produced by recreational pursuits.


[Noise and hearing].

[Noise and hearing]. The injuries induced by noise to auditory system affect above all the inner ear. Thus the hair cells forming the most fragile structures of the sensorial neuro-epithelium will suffer from hair disturbances. As a result these lesions will reduce hearing acuity and sensitivity leading to noise induced hearing loss. There are two types of hearing loss. The sudden hearing loss, called acute sonorous trauma, or the insidious one due to industrial-like noises. On the other hand, noisy environments may have some effects on the intelligibility known as effects on the recognition of speech. To conclude, the epidemiological studies carried on all sections of the population, including teen-agers, revealed a worrying yielding of their hearing performances, probably resulting from excessive level of noisy surroundings as supposed some years ago by Glorig.


[Non-auditory responses to noise. Objective estimation. Experimental and individual analyses]. The physiological reactions to a strong noise are immediate and transitory: start, arousal reactions, postural oculo-cephalo-motor response, cardiovascular reactions with tachycardia and peripheral vasoconstriction, mydriasis. The chronic reactions to an occupational permanent noise are mostly a state of fatigue, lowering of the psychotechnic ability, aggressivity, transitory tachycardia and elevation of blood pressure, mainly diastolic. The best argument in favour of a correlation between these reactions and the noise is their reversibility with the cessation of the nuisance. The non-auditive responses to noise--including blood pressure variation--described for stimuli of moderate intensity considered as environmental nuisances are less evident. Among inhabitants of a town the neurophysiological examination of the modifications due to different demonstrate the evident perturbation of the sleep organisation: difficulties to fall asleep, need of a complementary rest. The epidemiological inquiries in noisy zones indicate however that, within a common population, 10% of the subjects feel very uncomfortable, but that 30% of them declare to be normal. The revendications and the trials against the factors of noise let us recommend to associate the efforts of physicians and of physiologists to those of acousticians experts. The different sonometric assays, the methods used in order to decide if a noise is a nuisance are described and should be widely used to demarcate very quiet territories (climatic areas) and sectors to be improved.


[Cardiovascular effects of noise].

[Cardiovascular effects of noise]. The circulatory response to noise is dominated by a peripheral blood vessels vasoconstriction, of greater magnitude when asleep than awake. Noise of lower frequency seems more able to produce this response. With repetition of the noise, adaptation and tolerance to it quickly appears. Meanwhile prolonged high level noise exposition induces an increasing prevalence of arterial hypertension among industrial workers. This increase is also clearly found in residential communities living near airports. Long-term exposure to noise is a dangerous nuisance, that can lead to an increase in arterial blood pressure and favour coronary artery disease development.


[Noise, sleep and behavior].

[Noise, sleep and behavior]. The negative effects of noise on sleep and behaviour have been related to three mechanisms: a physiological arousal (above a certain threshold of noise), an aversive reaction and an interference with non auditive neurophysiological and mental processes. The perturbation of verbal communication and the effects of sleep are the directly observable consequences. The negative effects of noise above a certain threshold on sleep have been demonstrated both in experimental conditions and in real life. They concern length, EEG pattern, and subjective quality and produce an increase of irritability and tiredness. There is no habituation. In all populations studied, strong discomfort is expressed by 50% of the subjects living in an area with an Ldn of 75 dB in the case of air traffic noise, the same results being obtained with ground traffic for a 5-15 dB higher level. Objective expressions of discomfort: use of aural protections, closing the windows, staying indoor, changing residence, increase linearly with the intensity of noise. Noise influences the incidence of stress-related disorders: hypertension, related cardio-vascular diseases, psychosomatic and psychological disorders. It has been shown by the use of different techniques (epidemiological studies based on the frequency of medical contacts, on the diagnoses made by general practitioners, on the use of specific drugs, and on the examination of the whole population) that the prevalence increases in relation with the level of noise in the vicinity of airports.(ABSTRACT TRUNCATED AT 250 WORDS)


[Noise: neuro-endocrine aspects].

[Noise: neuro-endocrine aspects]. Experimental study of neuro-endocrinological effects of noise stress shows neuro-mediator modifications. Exposure to stress induces a marked stimulation of the adrenergic structures which increases plasma concentrations of ACTH and glucosteroids. The increased secretion of the cortico-releasing factor (CRT) from the hypothalamo-hypophyseal system mediates a complex cascade in which other neuro-modulators also participate. Within the CNS, CRF activates the sympathetic nervous system, raising plasma concentrations of epinephrine and nor-epinephrine. These neuro-mediator and endocrine variations modify the activity of central nervous structures, mainly hypothalamic (endocrine) and hippocampic (emotion) formations, inducing many homeostatic perturbations. Stress also causes marked alterations in the immune function. In chronically noise-stressed patients, a comparative clinical study showed a significant increase of the plasmatic STH, but no modification of others biological parameters. Some psychosomatic disorders and also a psychological unbalance were seen in these patients. The final response to a stressful event will either be no or certain specific chemical and physiological changes which will depend greatly on the ability of the individual to cope with the outside stimuli.


[Legal aspect: regulation].

[Legal aspect: regulation]. We gather, under the expression of regulation, both Parliament Acts and general texts emanating from executive Authorities. The analysis must be made according to the source of noise. So we have successively examined noisy equipment, industrial, commercial and agricultural activities producing noise, noisy material, carriage, leisure activities, building and neighbourhood noises, and after all the protection of working people. We have also studied the organization of the fight against noise, since it depends on law. Finally, this regulation is already very rich, including both texts directly concerning the fight against noise and other texts belonging to wider regulations (protection of environment or protection of working people). On the whole it seems to be well adapted to its objective, the prevention, even if it may be completed. The main thing is a better application to matters concerning everyday life and striking opinion, such as neighbourhood and traffic noises. It will be surely evolutive, first by connection with related and wider regulations, and above all according to the progress of our scientific and technical knowledge. Thus it will be constantly adapted, if exactly applied, to the needs of prevention.


[Is nutritional intervention influencing lipid allowances beneficial?]. An earlier study (consumption study) has shown that in subjects eating normally: 1) the amount of fat consumed per day corresponds to 4/5 of the fat contained in the portions served; 2) the distribution of the fatty acids (FA) consumed is unfavorable because of the use of saturated FA for food preparation and cooking and because of the elimination of mono- and polyunsaturated FA in the unconsumed food. In order to determine whether a simple nutritional intervention might favorably modify the distribution of FA consumed, a computer simulation of a decrease in allowances of saturated FA in exchange for an increase in mono- and polyunsaturated FA was tested. The laboratory results were compared to those of the computer program. Comparison of the intervention study with the consumption study revealed that: 1) the fat content was identical; 2) there were the same number of total calories, but there were more lipidic calories consumed during the intervention (38% instead of 35%); 3) the distribution of FA more nearly approached the recommended amounts: 40% saturated FA (-25%), 39% monounsaturated FA (+8%), 21% polyunsaturated FA (+91%) and a P/S ratio of .60 (instead of .21); 4) these proportions can be explained by a decrease in palmitic (-30%) and stearic (-20%) acids and by an increase in linoleic (+100%) and linolenic (+40%) acids; 5) the allowances of elaidic acid was on the average 4.3 g per day and had little influence on the P/S ratio; 6) the omega 6/omega 3 ratio (ratio of 7) was higher than that of the consumption study (ratio of 5); 7) there was a 16% decrease in cholesterol intake (260 mg instead of 310 mg). The laboratory findings corresponded on the whole to those of the computer program that only faulted by overestimating lipid and cholesterol allowances.


[Antibiotic residues and digestive microflora]. Can antibiotic residues modify the human gut flora, and select drug resistant bacteria? In volunteers given ampicillin (1.5 mg/d) or oxytetracycline (2 mg/d), the fecal excretion of resistant enterobacteria was not changed significantly. However a possible effect would be hidden in human beings by the huge day to day fluctuations in the resistant bacterial populations. Heteroxenic mice (i.e. germfree mice associated with the flora of a human donor) and dixenic mice (i.e. mice harboring 2 isogenic strains, one of which carries an R-plasmid) are possible models to study the gut flora in vivo without contaminations and interfering factors. Minimum selecting doses in these models are between 0.5 and 10 mg antibiotic per liter of drinking water. These doses are smaller than what a consumer could ingest in food. Last, fecal resistant enterobacteria directly come from contaminated food, as shown by their clearance from stools of volunteers eating a sterile diet. Hence antibiotic residues do not modify significantly the gut flora.


[Advertisements for the treatment of obesity or deceit without limits]. In magazines the advertisements for slimming diets or products are more and more frequent. The study of these advertisements shows that most of them do not give any indication on the composition of products or on the nature of the proposed methods. The selling arguments are the most often fallacious: freely diminution of body weight without dieting and physical activities, lack of checks, no successive increase of body weight, dramatic and quick slimming, debatable informations on the mechanisms of actions. In addition these treatments are followed without medical supervision. They are the antithesis of the right therapeutics of obesities. The diffusion of these methods as that of the numerous books on the slimming diets or technics in various European countries requires a study in order to protect the patients against their exploitation and a proposal of legislation for the European Countries in the whole which will make up the future Great European Community.


[Iatrogenic illness observed in the hospital environment. I. A report of 109 cases collected in a cross-sectional APNET study]. In an "on a given day" study, we analysed the prevalence and causes of drug-related and non-drug-related iatrogenic illnesses for educational and preventive purposes. Forty-three hospital departments of various specialties and involving 62 APNET members participated in the study. From a total of 112 cases reported, 109 were considered iatrogenic illnesses on the basis of the French criteria for adverse effects. Four major types of iatrogenic illness were defined, as follows: I--drug-related cases (n = 83); II--miscellaneous cases (n = 6); III--cases due to therapeutic instrumentation (n = 16); IV--cases due to diagnostic instrumentation (n = 4). Overall, 6.28% of the patients admitted presented an iatrogenic illness; 67 (61.46%) of the 109 cases concerned women and 66 (60.55%) concerned patients aged 65 years or more. The types of illness in the "drug-induced" and "miscellaneous" categories were endocrine and metabolic disturbances (n = 14), gastrointestinal conditions (n = 13) and hematological disorders (11 cases of bone marrow aplasia). Instrument-related iatrogenic illnesses comprised cardiovascular conditions (n = 6), locoregional anatomic lesions (n = 5), infectious complications (n = 3), bleeding (n = 3) and others (n = 3). Seventeen incidents were benign, 38 dangerous and 51 serious; there were three deaths. The main drug categories concerned in the 89 cases of "drug-related" and "miscellaneous" iatrogenic illnesses were as follows: cardiovascular agents (n = 20), antiinflammatory and analgesic drugs (n = 18), hormone and nutritional treatments (n = 11) and neuropsychiatric drugs (n = 11). Instrument-related iatrogenic illnesses chiefly involved venous approaches (n = 8), surgery (n = 4), intensive care procedures (n = 2), renal dialysis (n = 2) and radiation therapy (n = 2). The main causes of drug-related iatrogenic illnesses were self-treatment (n = 8), poor compliance (n = 8), and therapeutic errors (n = 27) [non-respect of a contraindication (n = 2), wrong indication (n = 6), excessive dose (n = 13), over-prolonged treatment (n = 2) and other errors (n = 4). A cost-analysis of 74 of the 109 cases gave a minimum figure of 2 million French francs. The human and financial costs of iatrogenic illnesses show that risk-prevention measures are required; these will be dealt with in a later paper, but should be based on stricter regulations and educational programmes aimed at doctors, patients, the general public, the pharmaceutical industry and the health authorities.


[Pheochromocytoma. Study of a personal series of 85 cases]. The study of a personal series of 85 cases observed by the same endocrinologist over a period of 40 years shows the modifications of clinical presentation and biological methods of diagnosis and treatment. There is a striking increase in the percentage of patients without any cardiac or vascular manifestations. The methoxyamines assay has the best sensitivity and specificity even in asymptomatic tumors. The recent development of this assay in the blood is very efficient. The tumor may be found with an abdominal CT scan. The use of NMR is not fruitful. The 131I MIBG scintigraphy is necessary if the CT scan is not informative and in malignant forms. The malignancy is more frequent (16.5%) than classical according to the long duration of the disease. The quite good prognosis is improved by the administration of 131I MIBG. The surgery was safer and without mortality over the last 15 years.


[Endemic goiter in the La Kara region (Togo). Analysis of etiologic factors]. Among 6,035 people living in 3 villages from the area of La Kara (Togo), 984 randomized subjects were investigated to evaluate goiter prevalence and related etiologic factors. Creatinine and thiocyanates (SCN-) were measured in urine, thyroid hormones and TSH in plasma. Iodine was evaluated in urine, water, salt, soil, millet and sorgho. The amount of cassava was evaluated in food. Mean goiter prevalence was 32%, reaching to 45.9% in one village; urinary iodine remained in a low range (27.2 +/- 2.18 micrograms/g creatinine in adults, 34.3 +/- 6.7 in children--m +/- SEM) independently of the presence of endemic goiter. Urinary SCN- was increased. Low iodine values were found in food, salt, soil and water which contained few mineral elements except flour which was increased in the samples collected in one of the 3 villages. Cretinism was absent, T4, T3, TSH remained in a normal range. This study confirms a high prevalence of endemic goiter in the area of La Kara with iodine deficiency, leading to an urgent iodine supplementation.


[A new regulatory mechanism of the action of corticosteroid hormones: cellular 11beta-hydroxycorticosteroid dehydrogenase]. Eleven-beta-hydroxysteroid dehydrogenase (11 beta OHSD) protects the aldosterone receptor (MR) against its occupancy by glucocorticoid hormones. We examined the intrarenal distribution of 11 beta OHSD, as compared to that of MR. MR were localized in histological sections from rabbit kidney, using immunohistochemical methods with an anti-MR monoclonal antibody. 11 beta OHSD activity was measured in isolated tubular segments from rabbit, rat and mouse kidneys. Tubules were incubated in the presence of tritiated corticosterone (3H-B:2 x 10(-8)M). Then the rate of degradation of 3H-B into 3H-11-dehydrocorticosterone (3H-A) was determined by HPLC. MR was immunodetected in the distal tubule and the collecting duct. No positive staining was present in the proximal tubule. The conversion rate of 3H-B into 3H-A was high (approximately 80%) in the distal and collecting tubule. It was low in the proximal tubule (less than 15%) except in the rat (approximately 50%). These results indicate that MR and 11OHSD are colocalized along the mammalian nephron. This colocalization constitutes a strong argument in favor of the MR-protective role of 11 beta OHSD, and of a role of a defect of this enzyme in the genesis of some types of arterial hypertension.


The burden of oral disorders in a population of older adults. This paper describes the burden of oral disorders in a population of adults aged 50 years and over living independently in the community. In so doing it uses clinical, functional, experiential and psychosocial impact measures to document the oral health status of this section of the population. The data reveal that substantial proportions of subjects report that their quality of life was compromised in some way by oral problems. Although only 24.1 per cent were edentulous, 30.5 per cent were unable to chew one or more foods; 37.2 per cent reported oral or facial pain in the previous four weeks and 67.5 per cent experienced one or more other oral symptoms. One third reported problems with eating and communication--social interaction, 18.7 per cent worried a great deal about their oral health and 30.8 per cent were dissatisfied with some aspect of their oral health status. Income was consistently associated with all health status measures examined, demonstrating the scope of inequalities in oral health. In addition, regression analysis showed that low income groups had higher scores on a psychosocial impact scale after controlling for clinical, functional and experiential oral health indicators. The paper illustrates the utility of a model of disease and its consequences derived from the international classification of impairments, disabilities and handicaps in exploring oral health.


Dental anxiety and oral health in young Israeli male adults. Dental anxiety may be a serious limiting factor in providing adequate dental treatment. The present study sought to define the prevalence of dental anxiety in a cross-section of young Israeli adults (389 male Israeli army recruits) to correlate anxiety scores with their oral health status and to compare the findings with existing data. The main stimuli triggering anxiety were found to be in the following descending order: seeing the needle, feeling the drill, and feeling pain despite local anaesthesia. A positive correlation was found between the degree of anxiety and the dental status; the highest percentage of untreated patients was found in the high anxiety group. It is concluded that young adult Israeli males manifest dental anxiety in a manner similar to that reported in the United States and Sweden. Dental anxiety may be an important factor in the avoidance of seeking dental care.


Two critical confounding factors in periodontal epidemiology. The prevalence and severity of periodontitis is considerably lower than was previously estimated. The available epidemiological methods are based on the premise that loss of periodontal attachment is a unique sign of periodontitis. However, additional factors resulting in loss of periodontal attachment confound data obtained from modern studies. The physiological process of continuous tooth eruption results in loss of periodontal attachment over a lifetime, at an approximate rate of 0.1 mm/year. Anthropological and clinical evidence for continuous tooth eruption is reviewed. The position of the alveolar crest appears to be stable; loss of periodontal attachment occurs as the teeth erupt and less of the root is embedded in bone. Retrograde periodontitis caused by pulpal disease is a known cause of severe, localised destruction of periodontal tissues. Its signs and symptoms include periodontal pocket formation, purulent inflammatory exudates, angular bone loss, swelling and bleeding of the gingival tissues and increased tooth mobility. Anthropological, experimental and clinical evidence for retrograde periodontitis is discussed. Misdiagnosis of angular (hemiseptal), furcal and other forms of localised periodontal damage as periodontitis has probably resulted because of the inability to determine the quality of pulpal health and the assumption of a gingivitis-periodontitis continuum. New epidemiological methods need to be developed in which physiological and all pathological conditions which affect the periodontal attachment are recognised and appropriately categorised.


Tooth surface loss and associated factors among factory workers in Finland and Tanzania. The relative importance of various factors in the occurrence of tooth surface loss was explored in a, cross-sectional study using blind dental examinations. Two samples were drawn; one from Finland, comprising 186 workers from four factories and another from Tanzania of 180 workers from two factories. Among the 326 dentate individuals who participated, 164 were exposed to acid fumes and 162 were not. In Finland, people with tooth surface loss were older and smoked cigarettes less frequently. In Tanzania, those with tooth surface loss were also older and the proportion of subjects with the condition was significantly higher among people not using a commercial toothbrush and those exposed to acids. Among the Tanzanians, exposure to acids increased the probability of tooth surface loss to a high level of significance, and increasing age increased its probability, both among the Finns and the Tanzanians. Both anterior and posterior teeth were affected. It can be concluded that if the exposure to acids from the air breathed is high, the probability of tooth surface loss will increase. It seems that explanatory factors for tooth surface loss from one society cannot be extrapolated to another.


A comparison between the dental health of 3-year-old children living in fluoridated Huddersfield and non-fluoridated Dewsbury in 1989. A study was undertaken to compare the prevalence of dental caries and developmental defects of enamel between 3-year-old children who were lifelong residents of fluoridated areas of Huddersfield (1 ppm F) and non-fluoridated Dewsbury (less than 0.3 ppm F). An interview was also conducted with the parents of the children to provide information regarding previous dental experiences. The study populations were identified using the national child health system. The mean dmft was 0.30 in Huddersfield and 0.74 in Dewsbury. The percentage of children who had experienced dental caries and the percentage with carious teeth were significantly lower in the fluoridated area. The Dewsbury children had suffered more toothache. There was a significantly higher number of children in Huddersfield with diffuse enamel defects on their upper and lower first molars. This study has also demonstrated that the national child health system provides a method for obtaining a random sample of pre-school children from the general population, thus avoiding the problems associated with studies using selected populations. Fluoridation in Huddersfield ceased in October 1989 and it is hoped that this decision will be reversed as soon as possible.


Provision of crowns in Scotland--a ten year longitudinal study. The annual reports of the Scottish Dental Practice Board have shown a dramatic increase in the number of crowns provided in the general dental service between the years 1978 and 1988. This paper investigates the changes in crown provision for a sample of dentate adults in Scotland whose dental treatment records have been monitored longitudinally. One hundred and sixteen out of a sample of 720 patients received one or more crowns over the ten year period between 1978 and 1988. A total of 213 crowns were placed, the majority of which were constructed of porcelain. Forty eight of them were replacements for crowns which had been supplied prior to or during the study period. A preliminary life table analysis estimates the median survival time of the crowns to be at least 10 years.


The oral health status and health behaviour of 12 and 15 year-old adolescents in Jakarta, Indonesia. Indonesia is a developing country with few dental services and a population at risk to deteriorating oral health. Five hundred and ninety-one 12 and 15 year-old children drawn from a low fluoride (F- less than 0.1 ppm) urban area of Jakarta, Indonesia were examined for dental caries, fluorosis, and periodontal diseases. In addition, a questionnaire was administered investigating socio-demographic background, use of dental services, and preventive oral care. Although the severity of dental caries experience was moderate, untreated caries on the occlusal surface formed the highest proportion of the dental caries experience. CPITN examination revealed a large proportion of the subjects had calculus as their highest score, combined with a substantial number of sites which exhibited bleeding on probing. Questionnaire data revealed a high home use of fluoridated toothpaste by the subjects but a predominant use of dental services for pain relief. Findings from this study suggest a need for primary preventive programmes focusing on occlusal sealants and plaque control.


The uptake and completion of dental treatment using a mobile clinic in central Birmingham, UK. The provision of a mobile dental service at a primary school in a socially deprived, multi-ethnic area markedly increased the uptake and completion of treatment after a school dental inspection. Eighty one per cent of children who were offered treatment in the mobile clinic accepted it and 91 per cent of these completed it. In the previous year, when care was offered at a health centre within half a mile of the school, the corresponding figure was 43 and 4 per cent. Over half the children seen in the mobile clinic had not previously visited a dentist.


Mechanisms and patient compliance of dust-mite avoidance regimens in dwellings of mite-allergic rhinitic patients. We report on the mechanisms, the environmental changes and patient compliance with regard to conventional and new dust and mite avoidance measures to prevent allergic symptoms caused by mite allergens, taking into account both allergen contamination and the developmental success of pyroglyphid Acari. Twenty patients with persisting rhinitic complaints were selected and matched. Although the patients had performed some conventional dust and mite avoidance measures (patient compliance was 90%), the dwellings proved to be a stimulus for mite development. Moisture problems due to faulty construction and excessive moisture production were common. Since humidity conditions could not be changed at short notice, the 20 homes were subjected to the new variants of mite allergen avoidance based on intensive cleaning without (control) and with an acaricide incorporated (acaricidal cleaner [Acarosan]). After the carrying out of conventional avoidance measures, these patients still had allergic symptoms, and dust from only 23 to 52% of their textile objects was under the proposed guanine (mite faeces indicator) risk level. Only the acaricidal cleaner was able to decrease the allergenic mite load (and the burden of the patients) significantly in this 12 month period. With respect to mite-extermination, acaricidal cleaning was 88% better than intensive cleaning. Reduction of guanine was 38% better in the Acarosan treatment group. Clinical results have been reported elsewhere. A significant difference in favour of the acaricidal cleaning was seen in both subjective (as regards symptoms) and in objective data (total IgE). Another 50 patients were questioned.(ABSTRACT TRUNCATED AT 250 WORDS)


Low dose fenoterol aerosol protects against histamine-induced bronchoconstriction in mild asthmatics: a dose response study. Sixteen subjects with mild stable asthma participated in a randomized double blind study on the effects of low dose fenoterol against histamine induced bronchoconstriction. Fenoterol aerosol at concentrations of 10, 50 and 200 micrograms and placebo were delivered at random through a metered dose inhaler as a single dose 30 min before histamine challenges on four separate occasions. Compared to placebo a fenoterol dose of 10 micrograms provided significant bronchodilatation (sRaw [s.d.] 8.3 [2.73] vs 6.3 [1.74] cm H2O* s [P less than 0.05]) and protection (PC100 sRaw [s.e.m.] 0.72 (1.31) vs 1.45 (1.39) mg/ml). The bronchodilatory and protective actions of fenoterol were more pronounced after the inhalation of 200 micrograms (P less than 0.05) with no difference between 10 and 50 micrograms fenoterol aerosol. The magnitude of bronchodilatation and protection was not correlated (r = 0.15). The results from this acute study may suggest that fenoterol at doses up to 20 times lower than routinely recommended may be an effective treatment in mild asthmatics.


Specific immunological and bronchopulmonary responses following intradermal sensitization to free trimellitic anhydride in guinea pigs. We have developed a guinea pig model of trimellitic anhydride-induced airway hypersensitivity responses. In one group of guinea pigs, injected intradermally with 0.1 ml 30% trimellitic anhydride (TMA), we examined the specificity of the bronchopulmonary response to TMA comparing the effect of intravenous TMA conjugated to guinea pig serum albumin (GPSA) with a control hapten (procion dye) protein conjugate (PD-GPSA). A significant increase in pulmonary inflation pressure (PIP) was provoked in sensitized animals following intravenous injection with TMA-GPSA (20%; 0-400, median; range) as compared to intravenous injection of PD-GPSA. In the second group we compared three different methods of sensitization: single injection of 0.1 ml of 0.3% TMA; four injections of 0.1 ml of 0.1% TMA; and a single high dose injection of 30% TMA. Following intravenous TMA-GPSA guinea pigs sensitized with a single injection 0.3% TMA had an increase in PIP of 395%; 220-600, while those given four repeat injections of 0.1% TMA had an increase in PIP of 343%; 315-490. These results were significantly higher than the increase in PIP (160%; 0-220) which occurred in guinea pigs sensitized with a single dose of 30% TMA. Four of 11 guinea pigs given low dose injections of TMA had bronchopulmonary responses to inhaled TMA-GPSA. All sensitized guinea pigs had specific IgG1 antibodies demonstrated by enzyme linked immunosorbent assay (ELISA) and confirmed by ELISA inhibition. Four guinea pigs sensitized by low dose injections of TMA had IgE antibodies demonstrated by passive cutaneous anaphylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)


Dynamics of mast cells in the nasal mucosa of patients with allergic rhinitis and non-allergic controls: a biopsy study. Mast cell degranulation is thought to be an important component of the pathogenesis of allergic rhinitis. Quantitative studies on mast cells in nasal mucosa after allergen exposure have given widely divergent results, ranging from an overall decrease via redistribution to an overall increase. We investigated this problem by employing a combination of anti-IgE and toluidine blue staining of biopsy specimens. In allergic patients anti-IgE was found to identify all mast cells and toluidine blue to detect mast cells that were not (totally) degranulated. The study was composed of two parts done in different patient groups. In the first part of the study biopsies were performed in 23 patients with isolated grass-pollen allergy, once during natural provocation in the summer and once in the winter. Biopsies were also performed in 12 controls. Non-allergic controls were found to have the same number of mast cells in the lamina propria as asymptomatic allergic patients. The controls seldom have mast cells in the epithelium. The patients with isolated grass-pollen allergy showed an increase in the numbers of mast cells in the lamina propria during natural provocation and the same seemed to occur in the epithelium as well. During natural provocation almost all of the mast cells in the epithelium and half of those in the lamina propria were degranulated. In the second part of the study 17 patients with isolated grass-pollen allergy and four controls were challenged daily with allergen extract during a 2-week period in the winter. During this period biopsies were performed at eight different occasions, i.e. once before, six occasions during and once after the provocation period. The results of this part of the study showed that during provocation mast cells migrate to the surface of the nasal mucosa, where they become degranulated, and that the pool of mast cells in the lamina propria was apparently replenished by migration of mast cells from the vessels in the lamina propria. The total number of mast cells in the lamina propria remained approximately the same while the mast cells residing in an increasingly thick layer measured from the basal membrane into the lamina propria became degranulated. After 2 weeks, 82% of the mast cells in the lamina propria was degranulated and it was only in the deepest layers that some toluidine blue positive cells were found.(ABSTRACT TRUNCATED AT 400 WORDS)


Getting patients to say yes: effective case presentations. Getting patients to say yes to recommended treatment requires the dedication of each team member. It demands a commitment to educating patients and motivating them to turn their dental needs into dental wants, as well as providing financial options to make treatment affordable. When the dental team takes the time to nurture the case presentation process, the results can be dramatic. Patients embrace treatment and the practice provides it. It is nothing short of a win-win scenario.


The dental practice purchase/sale--creating a win-win transaction. The importance of the dentist-patient/client relationship makes the dental practice purchase/sale unique compared with other business transactions. Dental practice goodwill can be easily lost, but establishing mutual trust between purchaser and vendor can lead to a win-win transaction through maximizing practice goodwill and minimizing associated taxes. Tax planning for the purchase/sale is complex, and, although this article has provided some basic information, professional advice is recommended.


Oral pathology in Canada: a survey.

Oral pathology in Canada: a survey. The Canadian Academy of Oral Pathology conducted a survey of its active members to obtain information on their demographics, professional activities and university affiliations, and to assess Canada's present and future oral pathology needs. Data were also collected on Canadian oral pathology diagnostic biopsy services. This paper reports the salient findings of the survey, and discusses their implications for the specialty of oral pathology as well as for the Canadian dental community.


Vital tooth bleaching: review and current status. Vital tooth bleaching refers to the clinical application of a chemical solution to a tooth surface in order to achieve a lightening effect. This article reviews the available literature to address the following questions: What are the methods of vital bleaching? How does vital bleaching work and is it effective? What effects are there on the teeth, dental restorative materials, soft tissues and systemic health? The techniques used in the application of dentist-applied and patient-applied bleaching systems are described. Generally, vital tooth bleaching has been found to be effective, however, relapse does occur. The literature suggests that bleaching agents may have transient effects on the tooth itself, and may affect some dental materials. Soft tissues exposed to hydrogen peroxide for prolonged periods show changes consistent with inflammation or hyperplasia. Hydrogen peroxide may also potentiate the carcinogenic effect of known carcinogens. However, more clinically relevant studies are needed. Until long-term safety data becomes available, the dental practitioner should approach the use of in-home bleaches with caution. The U.S. Food and Drug Administration (FDA) recently classified these products as "new drug." However, dentist-applied bleaching gel systems are a viable alternative and deserve further consideration. They are simple to use, require little armamentarium, and limit the exposure of the bleaching agent to the teeth only. Vital tooth bleaching refers to the clinical application of a chemical solution to a tooth surface in order to achieve a lightening effect. There was a resurgence of interest in vital bleaching with the recent introduction of the in-home bleaching technique.(ABSTRACT TRUNCATED AT 250 WORDS)


A preliminary comparative study of the retentive properties of four post and core systems in etched preparations. Post and core systems anchored and supported by endodontic files, Para Posts, Boston Posts and Flexi Posts were subjected to tensile testing in an Instron testing machine. All forces were applied to the cores until the post-core system was removed. The test results revealed no statistically significant difference among post and core systems built up with Para Posts, Boston Posts or Flexi Posts. The endodontic files proved to be significantly less retentive than the other post systems evaluated. Under the conditions of this study, the use of endodontic files as retentive posts is not supported.


Perinatal supraventricular tachycardia.

Perinatal supraventricular tachycardia. To determine the incidence, therapy required and prognosis of perinatal supraventricular tachycardia (SVT). Retrospective chart review of eight years. Tertiary level perinatal and pediatric centres in Halifax, Nova Scotia. All newborn infants who developed SVT either in utero or in the first 30 days of life. SVT was present in 33 neonates, with a male:female ratio of 2.7:1 and an incidence of 1:4347. Fetal SVT was recorded in nine (group I) but these patients did not differ from those with postnatal SVT (group II) in birthweight, noncardiac illnesses and associated heart disease. Thirty-one of the babies (94%) received digoxin and eight (24%) also required propranolol. All were asymptomatic after 48 h. One late death occurred due to renal failure unrelated to the dysrhythmia. No major congenital heart disease was found in either group. Follow-up over 44 months revealed four late relapses requiring prolonged therapy. Perinatal SVT is a common disorder in a tertiary centre and may represent a transient adaptation phenomenon. It is usually benign, easily treated and rarely associated with major congenital heart disease.


Slow rehydration improves the recovery of dried bacterial populations. Slow rehydration of bacteria from dried inoculant formulations provided higher viable counts than did rapid rehydration. Estimates were higher when clay and peat powder formulations of Rhizobium meliloti, Rhizobium leguminosarum biovar trifolii, and Pseudomonas putida, with water activities between 0.280 and 0.650, were slowly rehydrated to water activities of approximately 0.992 before continuing the dilution plating sequence. Rhizobium meliloti populations averaged 6.8 x 10(8) cfu/g and 1328 cfu/alfalfa seed greater when slowly rehydrated from bulk powder and preinoculated seeds, respectively. Bulk powder samples were slowly rehydrated to 0.992 water activity by the gradual addition of diluent, followed by a 10-min period for moisture equilibration. Preinoculated seed samples were placed in an environmental chamber at 24 degrees C with relative humidity greater than 80% for 1 h to allow moisture absorption. "Upshock," osmotic cellular stresses that occur during rehydration, was reduced when dried microbial formulations were slowly rehydrated and equilibrated before becoming fully hydrated in the dilution plating sequence. These procedures may also be applicable when estimating total viable bacterial populations from dried soil or other dry formulations.


Migration and imaging of 111Indium-labelled lymphocytes in cardiac allograft rejection. The diagnosis of cardiac allograft rejection is based on routine endomyocardial biopsy. To study an alternative method the authors evaluated the migration and scintigraphic imaging of 111Indium-labelled lymphocytes in a model of acute heart allograft rejection. Cervical heterotopic heart transplantation was performed in 10 dogs. Blood samples were harvested at 24 and 48 h after surgery for labelling of 36 +/- 6 x 10(6) lymphocytes with 6.62 +/- 0.56 MBq of 111Indium. Daily blood samples and heart biopsies were obtained for nuclear counting on the next three days; animals were sacrificed and both donor and native hearts were studied. Between 20 and 31% of autologous labelled lymphocytes remained in circulation until 72 h after injection. Maximal plasma 111Indium activity was 315 +/- 90 compared with 5513 +/- 1483 cpm/mL in whole blood (P less than 0.05). An average of 10,176 +/- 3444 labelled lymphocytes per gram of tissue were present in allograft biopsies while histological evaluation showed mild to moderate acute rejection. The ratio of tissue biopsy to blood 111Indium counts varied from 0.7 +/- 0.2, 6 h after autologous injection to 8.5 +/- 3.8 48 h later (P less than 0.05). At autopsy, 298 +/- 66 labelled cells per gram of tissue were present in native hearts compared with 2686 +/- 711 in allografts (P less than 0.05). Scintigraphic imaging using holospectral acquisition was performed; six lateral projections showed an indium activity ratio (transplanted heart to background tissue) of 2.8, 24 to 72 h after autologous injection of labelled cells. Labelling of a small number of lymphocytes with 111Indium gave a stable population of circulatory lymphocytes for studying migration of labelled cells into allografts and a noninvasive scintigraphic approach to diagnose cardiac allograft rejection.


Synthesis of the ferredoxin-like protein FdxN from Rhizobium meliloti bacteroids as a fusion protein in Escherichia coli. To analyze the overexpression of the Rhizobium meliloti fdxN gene in Escherichia coli, different translational and transcriptional fusions were constructed. The translational signals of R. meliloti fdxN were recognized in E. coli as demonstrated by the use of in-frame lac fusions. Translational fusions consisting of the lacZ or the lpp gene fused in frame to the 3' end of the entire fdxN gene were expressed at high levels in E. coli. In contrast, the wild-type R. meliloti FdxN protein without a C-terminal fusion could only be detected using the very sensitive T7 promoter-polymerase system and not in immunoblots with antibodies against an FdxN-LacZ hybrid protein. Evidently, translational fusions to the 3' end of fdxN had a stabilizing effect on the expression of the fdxN gene. A constitutively expressed transcriptional fdxN fusion, which did not mediate detectable amounts of FdxN protein either in E. coli or in free-living R. meliloti cells, complemented the Fix- phenotype of an R. meliloti fdxN::[Tc] mutant strain to wild-type levels. Therefore, either low amounts of the wild-type FdxN protein are sufficient for symbiotic nitrogen fixation or there are stabilizing factors, which are present only in R. meliloti bacteroids but not in free-living R. meliloti cells. Fusion proteins consisting of FdxN and LacZ or a partial Lpp protein restored the Fix- phenotype of an R. meliloti fdxN mutant to 3 and 11%, respectively, indicating that a C-terminal fusion did not completely abolish the function of FdxN.


Annulo-aortic ectasia extending to the arch: composite graft repair with circulatory arrest. To examine the results of surgery performed in patients with annulo-aortic ectasia extending to the arch. Retrospective hospital record review. A Canadian teaching hospital. Five patients (mean age 57 years) had annulo-aortic ectasia with severe aortic insufficiency, a maximum aneurysmal diameter ranging from 6.5 to 13 cm at the root or ascending aortic level, and extending into the arch with a diameter of at least 5 cm at the innominate artery level. They all had reconstruction with a composite prosthetic valve and Dacron tube graft employing standard techniques of aortic root replacement as well as aortic arch reconstruction with a single bevelled anastomosis in a state of profound hypothermia and circulatory arrest. No perioperative deaths, neurological complications nor significant cardiac complications. At a median follow-up period of 46 months all patients are alive, free from cardiovascular symptoms and show no evidence of aortic aneurysmal disease. This safe, effective and durable repair should be applied to selected patients with annulo-aortic ectasia which extends to the arch.


Similarities between legume-rhizobium communication and steroid-mediated intercellular communication in vertebrates. Regulation of the actions of flavonoids and Nod factors in legume-rhizobia communication has several interesting similarities with that of steroid-mediated actions in vertebrates. Oxidation or reduction of flavonoids and Nod factors modifies their biological activity just as, for example, oxidation of an alcohol at C11 on hydrocortisone regulates its biological activity. Second, some flavonoids are anti-inducers, functioning like steroid antagonists to negate the actions of inducer flavonoids. Amino acid sequence analyses show that human 17 beta-hydroxysteroid dehydrogenase, which catalyzes the interconversion of the alcohol and ketone at C17 on estrogens and androgens, and rat 11 beta-hydroxysteroid dehydrogenase, which catalyzes the interconversion of the alcohol and ketone at C11 of glucocorticoids, and Rhizobium meliloti NodG and Bradyrhizobium japonicum. FixR are derived from a common ancestor. Just as steroid-metabolizing enzymes can regulate steroid-mediated gene transcription, enzymes that modify substituents on flavonoids and Nod factors may have a similar role in regulating signalling between legumes and rhizobia. The enzymes that modify flavonoids and Nod factors have not yet been identified. However, NodG and FixR are two likely candidates to have this role in regulating legume-rhizobia signalling.


In vitro interactions between low density lipoprotein from hyperapobetalipoproteinemic plasma and arterial wall proteoglycans. To examine the interactions of low density lipoprotein-B (LDL-B) with proteoglycans (PG) in vitro. The PG were isolated from human aortas, removed at autopsy by a combination of extraction with 4M guanidine-Tris buffer containing protease inhibitors and fractionation on a DEAE-Sephacel ion-exchange chromatography column. LDL and LDL-B from healthy or hyperapobetalipoproteinemic sera, respectively, were isolated by standard density flotation techniques followed by radioiodination. Radiolabelled lipoproteins (LP) were incubated with proteoglycans at 4 or 37 degrees C in a low ionic strength buffer with or without addition of polyethylene glycol (PEG) which was used to enhance precipitation of the resulting LP-PG complexes. Data revealed that a specific ratio of LP to PG is a prerequisite for optimal interactions between these macromolecules. Further, it was observed that LDL-B forms fewer precipitable complexes than normal LDL at 4 degrees C. However, at physiological temperature or with the addition of PEG, precipitation of the two LDLs was equal. LDL and LDL-B showed equal reactivity with PG in terms of precipitable complexes.


Overexpression of the dctA gene in Rhizobium meliloti: effect on transport of C4 dicarboxylates and symbiotic nitrogen fixation. Symbiotic nitrogen fixation may be limited by the transport of C4 dicarboxylates into bacteroids in the nodule for use as a carbon and energy source. In an attempt to increase dicarboxylate transport, a plasmid was constructed in which the Rhizobium meliloti structural transport gene dctA was fused to a tryptophan operon promoter from Salmonella typhimurium, trpPO. This resulted in a functional dctA gene that was no longer under the control of the dctBD regulatory genes, but the recombinant plasmid was found to be unstable in R. meliloti. To stably integrate the trpPO-dctA fusion, it was recloned into pBR325 and recombined into the R. meliloti exo megaplasmid in the dctABD region. The resultant strain showed constitutive dctA-specific mRNA synthesis which was about 5-fold higher than that found in fully induced wild-type cells. Uptake assays showed that [14C]succinate transport by the trpPO-dctA fusion strain was constitutive, and the transport rate was the same as that of induced control cells. Acetylene reduction assays indicated a significantly higher rate of nitrogen fixation in plants inoculated with the trpPO-dctA fusion strain compared with the control. Despite this apparent increase, the plants had the same top dry weights as those inoculated with control cells.


The antiarrhythmic effect of the ACE inhibitor captopril in patients with congestive heart failure largely is due to its potassium sparing effects. To evaluate the mechanisms by which the angiotensin converting enzyme (ACE) inhibitor captopril may modify the presence of ventricular arrhythmias in patients with chronic heart failure. Forty-seven patients with chronic stable congestive heart failure. Twenty-four hour Holter monitoring was done prior to and after one month of therapy with the ACE inhibitor captopril. In a first group of 25 patients, changes in the incidence of ventricular arrhythmias were correlated with changes in cardiac hemodynamics (assessed invasively). In a second group of 22 patients, changes in ventricular arrhythmias were correlated with changes in echocardiographic measurements. In all patients serum potassium was kept constant, and changes in exercise tolerance and serum noradrenaline levels were assessed prior to and after captopril. One month of captopril therapy caused an improvement in cardiac hemodynamics and in exercise tolerance. It also led to a tendency for improved echocardiographic measurements and serum noradrenaline levels, similar to those already published by others. However, no change in the incidence or severity of ventricular arrhythmias was detected. No correlation could be found between changes in ventricular arrhythmias and any of the variables measured. As the only obvious difference between this and previous studies that documented a decrease in ventricular arrhythmias when ACE inhibitors were started in patients with congestive heart failure is a lack of change in serum potassium in this study, the current results suggest that the major antiarrhythmic effect of ACE inhibitors in patients with congestive hear failure is the result of their potassium sparing effects.


[Reintegration to work in persons having survived a myocardial infarction: current review and ways of development for clinical interventions]. The main purpose of this article is to update the state of knowledge regarding work reintegration following myocardial infarction. Occupational perspectives have greatly evolved during the second half of this century. This can be attributed mainly to a better understanding of the pathology itself and to a development of new therapeutic avenues which are part of a more global vision of the bio-psycho-social characteristics of the patient. The authors did not intend to realize an extensive review of the literature on the subject, but analysed the most significant articles published over the past 20 years. They were selected because of their frequent citation on the scientific literature which seems to confirm their significance and credibility. Following the analysis of the articles selected, the authors conclude that the scientific community has reached a consensus to the effect that the general evolution of the patient post myocardial infarction is greatly determined by psychosocial factors. It follows that comprehensive rehabilitation programs despite their limited impact in an experimental setting offer some stimulating perspectives. They suggest that some research effort be oriented towards the evaluation of the actual long term outcomes of rehabilitative programs especially on quality of life in general and on quality of life at work more specifically.


Opioid receptor agonists D-Ala-2-Me-Phe-4-Met-(O)-ol enkephalin and ethylketocyclazocine in the brain accentuate digoxin-induced arrhythmias. To examine the potential effects of two opioid receptor agonists in the brain on digoxin-induced cardiac arrhythmias and to explore cholinergic mechanisms in any potential effect on arrhythmias. Digoxin-induced arrhythmias were produced in guinea pigs (weighing between 280 and 350 g) that received digoxin 50 micrograms/kg intravenous bolus plus digoxin 500 micrograms/kg/h intravenously. Animals received D-Ala-2-Me-Phe-4-Met-(O)-ol enkephalin (FK 33,824) (50 or 100 micrograms/kg), ethylketocyclazocine (EKC) (50, 10 or 1 micrograms/kg) or saline (control) into the lateral cerebroventricle prior to digoxin. FK 33,824 produced significant (P less than 0.05) dose-dependent reductions in the threshold for digoxin-induced arrhythmias. The mean digoxin dosage at the development of fatal arrhythmias after the 100 micrograms/kg of FK 33,824 was 30% lower than the control group. EKC also produced significant (P less than 0.05) dose-dependent reductions in the threshold for digoxin-induced arrhythmias and the mean dose at development of fatal arrhythmias was 67% lower than the control group after 50 micrograms/kg of EKC. In the absence of digoxin, the highest dosages of each of these opioids did not produce arrhythmias. Changes in blood pressure and heart rate were unlikely explanations for the observed actions of these opioids because D-Ala-2-Me-Phe-4-Met-(O)-ol enkephalin accentuated the increase in blood pressure that accompanied digoxin while EKC reduced the blood pressure response to digoxin and neither altered the heart rate response to digoxin. In the control group, fatal digoxin-induced arrhythmias were ventricular tachyarrhythmias in two-thirds of cases and complete heart block in the remainder. These opioids accentuated the development of complete heart block. The role of the cholinergic system was explored for only EKC because both opioids produce similar effects on arrhythmias, using atropine sulphate which crosses the blood brain-barrier and atropine methylnitrate which does not enter the central nervous system. Atropine sulphate, but not atropine methylnitrate, slightly blunted but did not reverse the action of EKC. These data indicate that: two opioids in the brain--D-Ala-2-Me-Phe-4-Met-(O)-ol enkephalin and EKC--alter the threshold for development of digoxin-induced arrhythmias, specifically accentuating development of complete heart block produced by digoxin; and cholinergic mechanisms play only a small role in modulating the action of EKC on digoxin-induced bradyarrhythmias.


Epidemiology of dental diseases in the elderly. The aging of the American population will have enormous social ramifications, among which will be a greater focus on the elderly patient. Traditionally, the dental status of this group has been extracted teeth and full dentures, but that is now steadily changing. There were 41.1% of Americans aged 65 or older who were edentulous in 1985 to 1986, but a good proportion of them have been edentulous for many years. The prevalence of total tooth loss will continue to decline with time. The growth of a dentate elderly population, however, leaves more of that group at risk of caries. Caries, once seen as a disease of childhood, is now clearly a lifelong disease. Elderly persons are particularly at risk of root caries, which follows as a consequence of periodontitis. Total tooth loss and severe caries are both associated with lower socioeconomic status. Although cross-sectional survey data invariably show, on average, a greater extent of periodontitis among older than among younger persons, periodontitis is not considered a disease of aging. The age difference in surveys is not because of greater susceptibility among the elderly but represents disease accumulated over time. Limited longitudinal data suggest that rapid loss of periodontal attachment, serious enough to threaten the dentition, is found in 7% to 15% of any population. But this group exhibits the disease when young. Those who have retained a more-or-less intact dentition into old age rarely exhibit a sudden onset of periodontitis. If such a change is seen it could be indicative of broader changes in the immune system.


Epidemiology of nondental oral disease in the elderly. This article presents the descriptive epidemiology, risk factors, and clinical highlights of the oral mucosal lesions that are most common or of greatest concern among the elderly. Leukoplakia, oral cancer, candidiasis, lichen planus, and RAU have not been studied extensively among the elderly. Recent efforts to standardize definitions and research methods should greatly enhance future information. The paucity of research on oral lesions such as herpes zoster, epulis, and oral medication reactions is surprising, given that these are common problems among the elderly.


Oral sequelae of common geriatric diseases, disorders, and impairments. The oral cavity is responsible for two essential functions: the production of speech and the initiation of alimentation. All of the specialized oral tissues and sensory systems that allow for the execution of these functions are susceptible to age-, disease-, and treatment-related changes, and alterations in any one or more function may result in deleterious consequences to the host and impact on the quality of life. Oral physiology is generally believed to be age-stable in healthy individuals; however, in the presence of single or multiple medical diseases and their treatment, these functions deteriorate. This article focuses on the influence of common geriatric diseases, disorders, and impairments on oral health and function. Data are presented to suggest that oral health is altered in the presence of heart, cerebrovascular, liver, and renal diseases, cancer, COPD, diabetes, pneumonia, and influenza. Arthritic, hearing, visual, orthopedic, and speech impairments multiple medical problems. Finally, adjustments in treatment and management strategies may be necessary for older patients with these diseases and impairments.


Salivary gland dysfunction.

Salivary gland dysfunction. Clinically significant declines of salivary output are not a function of aging. Complaints of oral dryness (xerostomia) are common in the elderly patient, however. This complaint is most often a consequence of medications; tricyclic antidepressants, certain antihypertensives, and anticholinergics can cause marked decreases in salivary flow rates. Other medications such as diuretics may cause xerostomia without decreasing salivary output. Systemic diseases such as Sjögren's syndrome can destroy salivary glands. Specific serologic, ophthalmologic, and salivary findings are necessary for the diagnosis of Sjögren's syndrome. Radiation therapy for treatment of head and neck cancers also can damage salivary glands permanently. Infectious agents such as mycobacteria, Epstein-Barr virus, and various oral bacteria can infect human salivary glands. Diminished salivary output can lead to serious oral sequelae. Rapidly progressing dental caries and oral candidiasis are found frequently in this age group. Close supervision of the geriatric patient's oral and dental health is essential.


Oral candidiasis.

Oral candidiasis. Candida spp. can frequently cause oral infections in the elderly. A number of factors, including yeast virulence factors and compromised host defenses, contribute to outcomes of clinical disease. Precise mechanisms that determine the varied clinical appearances of oral candidiasis have not been delineated fully. Oral candidiasis should be suspected at the clinical level when oral mucosal lesions consistent with the various presentations of candidiasis are observed in patients at risk. Culture remains the gold standard for assessment, although results may be equivocal. Topical or systemic antifungal therapy may result in resolution of symptoms and lesions, but lesions may recur if underlying risk factors remain.