Changes in P300 latency and amplitude in schizophrenic patients and healthy controls during the examination. In 30 schizophrenic patients (sixteen of the paranoid subtype, 14 of the nonparanoid) and healthy controls (n = 30) event-related potentials were obtained with a somatosensory reaction-time (RT) version of the "oddball paradigm" by stimulating the right (first run) and the left (second run) median nerve. Variations of P300 amplitude and latency and of RT within the average (30 trials) were studied by fractionating off-line the original averages in three subaverages. After stimulation of the right median nerve oscillations on P300 amplitude and latency were observed. After stimulation of the left median nerve there was a trend toward a decrease of the P300 amplitude that reached significance at the electrode P3 for patients (p = 0.014) and at the electrode P4 for controls (p = 0.025). The P300 latency showed variations for patients and controls. The mean-RT was prolonged across the subaverages only for schizophrenics, reaching significance after stimulation of the right median nerve. Paranoid and nonparanoid schizophrenic patients showed similar results on P300 and RT parameters across the subaverages. These results are discussed in terms of the influence of motivation and task involvement on the P300 amplitude. These could be unspecific factors that account for the habituation of the P300 along the examination.


Functional relationship between brain regions in schizophrenia evaluated with Pearson's correlation between event-related potentials. As part of a study of the somatosensory P300 event-related potential (ERP) in paranoid and nonparanoid schizophrenic patients (8) Pearson's product-moment correlations between ERP waveforms were calculated to study the functional relationship between brain areas. ERP were recorded from F3, F4, P3 and P4; interhemispheric (F3 to F4; P3 to P4) and intrahemispheric (F3 to P3; F4 to P4) correlations were obtained. There was no significant difference among the paranoid and nonparanoid patients and healthy controls for both the interhemispheric and the intrahemispheric correlations. The lack of disruption of functional relationship between brain areas on the patients do not support the hypofrontality and the laterality hypothesis of schizophrenia. However, the use of neuroleptics by the patients, the study of the whole waveforms and not parts of them and the use of linked-ears reference could account for these negative results.


The relation between motor evoked potential and clinical motor status in stroke patients. Forty-one stroke patients and 41 normal controls of matched age, sex and body height were studied by magnetic stimulation of the motor cortex and lower cervical area. The cortical and cervical motor evoked potentials (MEPs) were detected from the abductor pollicis brevis muscle. The amplitudes and latencies of cortical MEPs, central conduction time (CCT), and interside difference of bilateral CCT (DCCT) in stroke patients showed significant difference in comparison with normal controls. The degree of motor weakness was statistically correlated with the severity of cortical MEP findings, but not with the deep tendon reflex and Babinski sign. The abnormal rate of cortical MEP was higher in patients with hemorrhage than in those with infarction. Six out of 17 patients with hemorrhage had prolonged CCT or DCCT, but only 3 out of 24 patients with infarction had the same findings. The cortical MEP findings in putaminal hemorrhage were more severe than in thalamic hemorrhage. In instances of infarction involving total middle cerebral artery territory (cortical and subcortical areas), the cortical MEP was absent in all cases (4/4). It was concluded that cortical MEP findings in stroke patients examined by magnetic stimulation showed good correlation both with the lesion radiologically and the motor deficit clinically. This is an acceptable method for quantitative evaluation of motor system function in stroke.


Flexor reflex for assessment of common interneurone activity in spasticity. The purpose of this investigation was to evaluate the alterations of flexor reflex parameters in spasticity and the possibilities to take advantage of them as a method for assessment of common interneurone activity. Clinical and electromyographical examinations were performed on 120 patients with spastic hemiparesis after stroke. The flexor reflex was obtained after supramaximal electrostimulation of the tibial nerve behind the ankle. The stimulus consisted of 50 msec train of 1 msec duration pulses given at 100 Hz. The reflex activity was recorded from the tibialis anterior muscle. As all patients were with hemiparesis the healthy side was used as a control. The patients were subdivided into four groups, each treated with different myorelaxants (Baclofen, Sirdalud, Myolastan and electroacupuncture). After about 25 days treatment the clinical and electromyographic examinations were repeated. The flexor reflex was recorded with two clearly distinguishable responses on the healthy, as well as on the spastic side. On the spastic side a reflex with prolonged latencies and durations, as well as with decreased amplitudes and thresholds of both reflex responses was found. On the spastic side the first reflex response had higher threshold than the second one, while on the healthy side it was vice versa. Moderate correlations were found between most of the reflex parameters. No correlations were found between the reflex parameters and the degree of spasticity. Only after Baclofen treatment all reflex parameters tended to normalized. After treatment with Myolastan, Sirdalud and electroacupuncture only the second response's duration shortened. In conclusion the flexor reflex is a sensitive method for assessment of altered common interneurone activity in spasticity.(ABSTRACT TRUNCATED AT 250 WORDS)


F-wave elicited during voluntary contraction as a monitor of upper motor neuron disorder. Since electrophysiological techniques for assessment of upper motor neuron disorders have yet to be standardized, the potential of employing F-waves to monitor this condition was examined. Subjects were 32 normal adults, 54 patients with upper motor neuron disorder and 20 patients with lower motor neuron disorder. F-waves were recorded from the abductor digiti minimi muscle at rest and under weak voluntary contraction. F-wave amplitudes expressed as a percentage of maximum M-wave were 1.98 +/- 0.83% at rest and 3.73 +/- 1.25% during voluntary contraction in normal group, compared to 3.69 +/- 1.81% and 3.62 +/- 1.68% in the upper motor neuron disorder group, 2.08 +/- 1.45% and 3.52 +/- 1.83% in the lower motor neuron disorder group, respectively. Analysing individual data, 69% of patients with upper motor neuron disorder showed an F-wave at rest within normal limits (+/- 2.5 standard deviation from normal). Voluntary muscle contraction enlarged the F-wave amplitude in normal subjects and patients with lower motor neuron disorder, but the facilitation did not occur in patients with upper motor neuron disorder. Combining F-wave amplitudes at rest and during voluntary contraction revealed differences between the upper motor neuron disorder group and the normal and lower motor neuron disorder groups. It was therefore concluded that F-waves can be used as a monitor of upper motor neuron disorder.


Passive long-latency event-related potentials in mental retardation. Long-latency auditory event-related potentials (ERPs) were passively recorded in ten mental retardates and ten age-matched normal controls. Patients were mildly to moderately retarded and had epilepsy controlled with monotherapy, ERPs were recorded from CA-A1+A2, with 1000 and 3000 Hz tones in an "oddball" paradigm. Latency and amplitude of N1, N2, P2, and P3 components were compared in controls and retardates. All ten patients had reproducible AEPs, but these were attenuated in amplitude in four, although amplitudes did not differ significantly from controls. P3 was prolonged in latency in four patients, but patients and controls did not differ significantly. AEP latency and amplitude was not correlated with degree of retardation. These findings suggest that "cognitive" evoked potentials an be recorded passively in persons with impaired cognition, but are not correlated with intellectual ability and may not reflect specific cognitive functions.


Reinforcing and punishing consequences of kindling. The motivational consequences of kindling were examined in the conditioned place preference paradigm. In a distinctive environment, rats received stimulation of the amygdala that triggered afterdischarge (AD) alone or AD and generalized seizures. After 4 conditioning trials, preference for the conditioning environment or a control environment was measured. Amygdaloid ADs associated with nonconvulsive seizures (stage 0) produced a conditioned decrease in time spent in the initially preferred chamber by rats receiving stimulation there, and they produced a conditioned increase in time spent in the initially nonpreferred chamber by rats receiving stimulation there. These effects were not large, in that there was no overall mean shift from preference to avoidance, or vice versa; but they were reliable and significant. Similarly, stage 5 seizures produced a small and nonsignificant decrease in time spent in the conditioning chamber in which seizures were triggered. It appears that amygdaloid AD produces weak effects that are either reinforcing or punishing, depending on the behavioral baseline, and that generalized amygdaloid seizures are, at most, mildly punishing.


Effects of valproate and E-2-en-valproate on functional and morphological parameters of rat liver. I. Biochemical, histopathological and pharmacokinetic studies. E-2-en-Valproate (E-2-en-VPA; trans-2-en-VPA) and VPA were studied for potential hepatotoxicity in young male Sprague-Dawley rats. Both drugs were administered daily at 750 mg/kg i.p. (divided into three doses a day) for 7 consecutive days. Clinical chemistry parameters were studied before and after the period of treatment. Furthermore, the drug pharmacokinetics and metabolism were analyzed at onset and end of the prolonged administration. Treatment with VPA induced hyperammonemia and other alterations in liver function tests which were not observed after treatment with E-2-en-VPA, although plasma levels of both drugs were comparable. The pharmacokinetics of VPA and E-2-en-VPA in young rats were similar, but analysis of metabolites by gas chromatography-mass spectrometry indicated marked differences in the metabolite profile, e.g., a lack of the suspected hepatotoxic metabolite 4-en-VPA in plasma of rats treated with E-2-en-VPA. Histopathological examination of liver sections showed that VPA and E-2-en-VPA did not induce degenerative liver lesions or significant alterations in hepatic content and distribution of lipids and glycogen at the doses administered. Only one of the VPA treated rats showed fatty infiltration (microvesicular steatosis). The data demonstrate that, although E-2-en-VPA is more potent than VPA as an anticonvulsant in rats, it does not exert more potent hepatotoxic effects and does not alter ammonia metabolism. Thus the data substantiate previous experimental studies that E-2-en-VPA might be a valuable substitute for VPA.


Lack of changes in seizure susceptibility during the estrous cycle in kindled rats. The threshold and pattern of focal and generalized seizures in fully kindled rats during the estrous cycle were investigated. Two groups of rats were studied; one was kindled from stimulation of the basolateral amygdala, the other from stimulation of the anterior portion of the posterior piriform cortex. Determinations of the threshold for focal afterdischarges were either carried out in the morning (between 8 and 9 a.m.) or in the afternoon (between 2 and 3 p.m.). In all experiments, stable and reproducible afterdischarge thresholds were obtained during the different stages of the estrous cycle. The only significant alteration was a reduced seizure duration during metestrus and/or the first day of diestrus in amygdala kindled rats. The data indicate that the natural changes in sex hormone levels during the estrous cycle in rats do not affect seizure susceptibility, at least in the kindling model of epilepsy.


Influence of electrical stimulus parameters on afterdischarge thresholds in the rat hippocampus. The influence of electrical stimulus parameters on focal seizure production was studied. Stimulations and recordings were carried out with bipolar electrodes stereotactically positioned in the ventral hippocampus of kindled rats. After discharge thresholds were determined for stimulus trains with different combinations of train durations (0.5, 1, 2, 5, 10 s), intratrain frequencies (10, 20, 50, 60, 100 Hz), and pulse widths (0.5 and 1.0 ms). For a given combination of pulse width and intratrain frequency, thresholds decreased as train duration increased; the effect was profound with shorter durations but markedly attenuated with train durations > or = 5 s. For a particular train duration and pulse width, thresholds varied inversely with intratrain frequency; the degree of variation in the thresholds with frequency was greater the shorter the train. For the train durations studied, thresholds were lower with 1.0-ms pulses for intratrain frequencies > or = 20 Hz. However, for 10 Hz, the 0.5-ms pulses were more effective for 2-, 5- and 10-s trains. After discharge thresholds were found to also vary with the number of pulses in the stimulus trains. For stimuli with fewer pulses, thresholds were higher and showed marked variation with train duration, intratrain frequency, and pulse width. For stimuli with more pulses, thresholds fell to a lower limit and the influence of train duration was substantially lessened. This study provides a systematic examination of the influence of stimulus parameters on generation of focal seizures and should prove useful in designing and interpreting future experiments studying the neurobiology of seizures in the hippocampus and related structures and helpful in antiepileptic drug testing.


Intravenous valproate: onset and duration of anticonvulsant activity against a series of electroconvulsions in comparison with diazepam and phenytoin. A series of 5 generalized tonic-clonic seizures within 30 min was induced by repeated transauricular electrical stimulation in mice. In this model, the anticonvulsant potency of intravenous valproate was compared with diazepam and phenytoin. All 3 drugs proved capable of rapidly suppressing the seizures after intravenous bolus injection. Potent anticonvulsant activity of diazepam and valproate was already obtained after 30 s, while phenytoin's onset of action was somewhat slower. In contrast to diazepam, valproate and phenytoin suppressed the seizures at non-sedative doses. ED50s for blockade of generalized tonic-clonic seizures throughout the 30-min period of repeated electrical stimulation were 6.6 mg/kg for diazepam, 28 mg/kg for phenytoin and 212 mg/kg for valproate. Determination of valproate in plasma and brain demonstrated that the rapid onset of anticonvulsant action after intravenous bolus injection was related to rapid drug penetration into brain tissue. The data indicate that an intravenous formulation of valproate might be a useful alternative to phenytoin as a non-sedative anticonvulsant for diazepam-resistant status epilepticus.


Kainic acid-induced thalamic seizure in cats--a possible model of petit mal seizure. Bipolar depth electrodes were implanted stereotaxically in the thalamus, hippocampus and midbrain reticular formation of cats. Cortical screw electrodes were placed over the bilateral sensorimotor cortex. A guide cannula with an inner injection cannula was inserted unilaterally into the posterolateral ventral nuclei (VPL) of the thalamus. Eight days after the procedures, kainic acid (2.0 micrograms) was injected unilaterally into the VPL via the injection cannula in freely moving animals and electro-clinical observations were made. About 1 h after the kainic acid injection, multiple spikes were observed in the VPL (injection site), which propagated to the subcortical structures. These seizures finally propagated bilaterally to the cortex about 2 h after the injection. About 3-4 h after the injection, small spike and wave complexes repeatedly appeared for a short period of time in cortical leads and cats exhibited behavioral arrest with unresponsiveness during the seizures. About 24 h after the injection, generalized small spike and wave complexes were observed intermittently in cortical and subcortical structures. They persisted for 4-5 s and were associated with behavioral arrest and staring. The results demonstrate that a unilateral microinjection of kainic acid into VPL induced petit mal-like seizure, and suggest that VPL plays an important role in the generation or transfer of spike and wave complexes.


Plasma urea and ammonia in epileptic patients and their relatives. The plasma levels of urea and ammonia were examined in patients with primary generalized epilepsy, patients with partial epilepsy and in the first-degree relatives of these subjects. The results show a significant decrease in plasma urea in both groups of patients and their first-degree relatives as compared to the non-epileptic controls. The plasma ammonia concentrations were significantly higher in both groups of patients and in the relatives of generalized epilepsy patients as compared to the controls. The observed changes in plasma urea and ammonia were found not to be due to the effect of anticonvulsant drugs. The data suggest that a metabolic defect in urea synthesis may constitute one of the genetic components in the multifactorial etiologies of primary generalized and partial epilepsies.


Conventional and controlled release valproate in children with epilepsy: a cross-over study comparing plasma levels and cognitive performances. We studied plasma levels and behavioural effects of a newly developed controlled release formulation of valproate (VPA-CR) in children with epilepsy. Valproate plasma levels and performances in attention and vigilance tasks were monitored during a 12-h period (daytime), both during monotherapy of conventional valproate (VPA) and 4 weeks after switching to a similar dosage of VPA-CR taken once daily. There was no significant difference between the two formulations with respect to mean diurnal trough and peak valproate plasma levels, and to mean fluctuation. The significantly higher Cmax/Cmin ratio during VPA-CR seems mainly due to low valproate plasma levels early in the morning. Neuropsychological assessment showed no significant differences, either between patients and controls, or within patients and controls when comparing the results obtained on the VPA and VPA-CR day. During both VPA and VPA-CR treatment, no correlation was found between cognitive performance and valproate plasma levels. The advantage of VPA-CR is that the once daily regimen may increase compliance and is more convenient for schoolchildren.


Light chain ratios and concentrations of serum immunoglobulins in children with epilepsy. Serum immunoglobulin G, A and M concentrations and their respective kappa/lambda (kappa/lambda) light chain ratios were studied in 26 children with epilepsy. Fifteen had cryptogenic West syndrome or Lennox-Gastaut syndrome and 11 had other forms of childhood epilepsy. The results were compared to the data of a reference group of healthy children. The mean serum IgG and IgM concentrations were respectively 2.2 g/l (P = 0.007) and 0.4 g/l (P = 0.016) higher in the 26 children with epilepsy compared to the reference group. The kappa/lambda ratios of total serum immunoglobulins, IgG and IgM were respectively 0.10 (P = 0.057), 0.20 (P = 0.001) and 0.14 (P = 0.005) lower in the children with epilepsy than in the reference group. IgA concentration and IgA kappa/lambda ratio were not affected. There were no significant differences between the kappa/lambda ratios of the West and Lennox-Gastaut epilepsy and the other types of childhood epilepsies. The results are further evidence of reciprocal interaction between the nervous system and the immune system in childhood epilepsy.


Peroxisomes in digestive gland cells of the mussel Mytilus galloprovincialis Lmk. Biochemical, ultrastructural and immunocytochemical characterization. The present study was undertaken because of the paucity of information on peroxisomes in molluscs and the increasing importance of these organisms as sensitive indicators of environmental pollution. Peroxisomes were identified by electron microscopy in all three main cell types of the digestive gland of the bivalve mollusc Mytilus galloprovincialis Lmk. They stained weakly with the alkaline diaminobenzidine reaction but showed distinct immunolabeling with an antibody against mammalian catalase by the postembedding protein A-gold procedure. In addition, mussel digestive gland peroxisomes were isolated by differential and metrizamide-density gradient centrifugation, and a 30-fold enrichment of catalase and a 20-fold enrichment of palmitoyl-CoA oxidase was obtained over the initial homogenate. By Western blotting, isolated peroxisomes crossreacted with antibodies to catalase and, furthermore, specific and prominent labeling of isolated peroxisomes was also demonstrated in thin sections incubated with anti-catalase antibodies. These observations establish that peroxisomes in molluscan digestive gland contain the peroxisomal marker enzymes catalase and acyl-CoA oxidase and that they can be labeled by cytochemical and immunocytochemical techniques. Further studies of alterations of molluscan peroxisomes by environmentally relevant xenobiotics are warranted.


Brefeldin A inhibits the formation of constitutive secretory vesicles and immature secretory granules from the trans-Golgi network. The effects of brefeldin A (BFA) on membrane traffic between the trans-Golgi network (TGN) and the plasma membrane were investigated in intact PC12 cells and in a cell-free system derived from PC12 cells. In intact cells, BFA caused a virtually complete block of constitutive secretion, as indicated by the lack of release from, and accumulation in, the cells of a [35S]sulfate-labeled heparan sulfate proteoglycan (hsPG). Pulse-chase experiments with [35S]sulfate followed by subcellular fractionation showed that this block was due to the inhibition of formation of constitutive secretory vesicles (CSVs) from the TGN. BFA did not block the depolarization-induced release of [35S]sulfate-labeled chromogranin B (CgB) and secretogranin II (SgII) from secretory granules formed prior to the addition of the drug, showing that BFA does not block secretory granule fusion with the plasma membrane. The presence of BFA did, however, prevent the appearance of [35S]sulfate-labeled CgB and SgII in secretory granules, indicating that the drug inhibits the formation of secretory granules from the TGN. Evidence for a direct block of vesicle formation by BFA was obtained using a cell-free system derived from [35S]sulfate-labeled PC12 cells. In this system, low concentrations of BFA (5 micrograms/ml) inhibited the formation of the hsPG-containing CSVs and that of the SgII-containing secretory granules from the TGN to the same extent (50-60%) as, and in a non-additive manner with, the nonhydrolyzable GTP analogue GTP gamma S. Consistent with the inhibitory effects of BFA on vesicle formation from the TGN, BFA treatment of intact PC12 cells led to the hypersialylation of CgB, which presumably was due to the increased residence time of the protein in the TGN. In conclusion, our data are consistent with, and allow the generalization of, the concept that the BFA-induced block of anterograde membrane traffic results from the inhibition of vesicle formation from a donor compartment.


Acidification slows the transport but does not influence the polarity of secretion of gp80 in the polarized epithelial cell MDCK. Madin-Darby canine kidney (MDCK) cells stably transfected with a recombinant chicken lysozyme gene were used to examine the effect of cytoplasmic acidification on the secretion of the endogenous gp80 glycoprotein complex and lysozyme. The effect was examined by pulse-chase and immunofluorescence analysis. If filter-grown monolayers were incubated at pH 5.8 the secretion of gp80 was retarded, and the transport of lysozyme was completely inhibited. The immunofluorescence analysis revealed an enrichment of both proteins in the endoplasmic reticulum. The transport block was reversible for both proteins upon transferring the filter-grown monolayer back into medium at pH 7.4.


NSP1 depletion in yeast affects nuclear pore formation and nuclear accumulation. The essential yeast nuclear pore protein NSP1 was placed under the control of the regulatable GAL10 promoter. GAL::NSP1 cells grow normally in galactose medium, but arrest in growth upon glucose-induced repression of the GAL::nsp1 gene. During NSP1 depletion, nuclear accumulation of two reporter proteins Mat alpha 2-lacZ and PHO2-lacZ is inhibited, and the chimeric proteins appear in the cytoplasm of GAL::nsp1 cells. Furthermore, the nuclear pore density decreases within the nuclear membrane during early NSP1 depletion. Upon reinduction of the NSP1 gene after NSP1 depletion, NSP1 is targeted to the nuclear envelope, the nuclear pore density increases, and nuclear accumulation of reporter proteins is restored.


Cytochemical characterization of two types of nuclear bodies in Cicer arietinum L. The present study was carried out to characterize two distinct types of nuclear bodies, the nucleolus-associated bodies (NABs) and the satellites (SATs) using some specific staining, enzyme and immunogold labeling techniques in Cicer arietinum L. These bodies are of interest as the functional components of plant nucleus. DNA-specific staining and labeling with anti-DNA, a monoclonal antibody, were employed to verify the presence of DNA in NABs as well as in SATs. The enzyme-gold labeling technique was used to compare the relative amounts of RNase-gold and protease-gold labeling over the NABs. In NABs, RNase-gold labeling was relatively low compared to the protease-gold labeling. Ag-NOR staining revealed a similar content of NOR-silver proteins in both NABs and granular zone of the nucleolus. The NABs do not contain any DNA as they show negative response to DNA-specific stains and also when incubated with anti-DNA, only few gold particles are found over these structures. The SATs, on the other hand, react positively with DNA-specific stains, and high labeling is recorded with anti-DNA along with the dense chromatin masses.


The effects of transforming growth factor-beta and serum on proteoglycan synthesis by tendon fibrocartilage. The effects of transforming growth factor-beta (TGF-beta) and serum on proteoglycan synthesis by tissue explants from the fibrocartilaginous region of adult bovine tendon and by cells in culture from this region were assessed. The most characteristic effect of added TGF-beta on both explant tissue and cells in culture was enhanced synthesis of one small proteoglycan-biglycan. Lowered serum concentration diminished incorporation of Na2 35SO4 into proteoglycans. Added TGF-beta (1 ng/ml) stimulated cell proliferation, increased overall proteoglycan synthesis, and increased the length of glycosaminoglycan chains on all secreted proteoglycans. The effect of TGF-beta on cells in culture was highly consistent whereas explants from different animals showed greater variability in the response. It was concluded that TGF-beta did not specifically promote or maintain the cartilaginous nature of this tissue because supplementing medium with TGF-beta did not significantly alter the ratio of large/small proteoglycans synthesized by tissue explants. However, the observation of enhanced biglycan synthesis by TGF-beta suggests that TGF-beta could be involved in differentiation of regions of tendon subjected to compression, because compressed tendon contains both decorin and biglycan small proteoglycans whereas tensional tendon contains primarily decorin. Excess decorin added to cell culture medium did not affect the ability of TGF-beta to enhance synthesis of biglycan.


Molecular characterization of vascular smooth muscle decorin: deduced core protein structure and regulation of gene expression. Two overlapping clones containing sequences homologous to bovine, human and chicken decorin have been recovered from poly A+ RNA isolated from rat vascular smooth muscle cells (VSMC) using cDNA cloning and reverse transcription-polymerase chain reaction (PCR) methodologies. Results of nucleotide sequence analysis performed on these clones demonstrated that they encode the complete mature rat decorin protein expressed by VSMC. Within the coding region, rat decorin exhibits 76% nucleotide sequence homology to human and bovine decorin, and 69% homologous to chicken decorin indicating a significant level of conservation among these species. This level of conservation among species was also maintained at the protein level with rat decorin being 77% homologous to its human, bovine and chicken homologues. As previously observed its human homologue, rat decorin, is made up of seven, tandem, leucine-rich repeat sequences. Furthermore, within the core of these repeats was the consensus protein sequence NKISK which has been proposed to be the fibronectin binding region of decorin (G. Schmidt et al., Biochem. J. 280, 411-414 (1991)). The vast majority of amino acid substitutions within rat decorin were of the conservative type. The highest frequency of amino acid substitutions were found to be localized within a hypervariable region located near the amino terminus of the decorin core protein. Unlike rat biglycan, rat decorin mRNA levels were found to increase significantly in density-arrested VSMC cultures. In contrast to rat biglycan gene expression, no quantitative differences in rat decorin mRNA levels were observed between proliferating VSMC and VSMC made quiescent through serum depletion. Finally, specific extracellular matrix (ECM) proteins were able to regulate the expression of decorin at the mRNA level in a slightly different manner than previously observed for biglycan.


Molecular organization and antiproliferative domains of arterial tissue heparan sulfate. Heparan sulfate isolated from mammalian arterial tissue inhibits the growth of homologous arterial smooth muscle cells when added to subconfluent cell cultures at a concentration of 50 to 100 micrograms/ml culture medium. Disintegration of the heparan sulfate molecule by hydrazinolysis that deacetylates N-acetylglucosaminyl residues and by subsequent treatment with nitrous acid at pH 3.9 results in the formation of a mixture of oligosaccharides which was further resolved into sulfate-enriched oligosaccharides with antiproliferative activity in an in vitro bioassay system. A decasaccharide and dodeca/tetradecasaccharide fraction had a significantly higher antiproliferative effect on arterial smooth muscle cells than the native heparan sulfate molecule. The antiproliferative oligosaccharides have a sulfate content of 0.9 to 1.2 sulfate groups/disaccharide unit and consist of 60 to 70% monosulfated, disulfated, and trisulfated disaccharide units. Up to 32% of the sulfate groups were in 2-position of the uronic acid. In contrast, nitrous acid degradation of heparan sulfate at pH 1.5, which cleaves glycosidic linkages of N-sulfoglucosaminyl residues, results in the formation of sulfate-poor or sulfate-free oligosaccharides without antiproliferative potency. The results indicate that (a) heparan sulfate has a heterogeneous molecular organization where sulfate-rich domains are separated by sulfate-poor sequences and that (b) the antiproliferative activity of heparan sulfate resides in domains enriched with 2-O-sulfated uronic acid residues.


Cell-associated proteoheparan sulfate mediates binding and uptake of thrombospondin in cultured porcine vascular endothelial cells. [125I]Thrombospondin (TSP) binds to porcine endothelial cells in a specific, saturable and time-dependent fashion and is endocytosed by a receptor-mediated process. The N-terminal heparin-binding domain is necessary for the interaction with the cell surface. Binding and uptake is inhibited by heparin and to a much smaller extent by other vascular glycosaminoglycans. Chemical modification of lysine and arginine residues of TSP, but not treatment of the molecule with neuraminidase, resulted in a pronounced loss of binding at the cell surface. Treatment of cells with heparitinase but not with chondroitin ABC lyase caused inhibition of binding and uptake of TSP. Inhibition of sulfation of proteoglycans on the cell surface by chlorate leads to a dose and time-dependent inhibition of binding and degradation of TSP. In the presence of chlorate, newly synthesized TSP is not incorporated into the cell matrix but mainly released into the culture medium, whereas localization and incorporation of newly synthesized fibronectin is not altered. A cell surface proteoheparan sulfate was identified as TSP binding macromolecule by affinity chromatography. The data emphasize the role of heparan sulfate proteoglycan as a receptor-like molecule for the specific interaction with thrombospondin.


Tissue-specific expression of type XIV collagen--a member of the FACIT class of collagens. The collagens represent a highly diverse superfamily of extracellular matrix proteins that can be divided into several distinct families. One of the families, called FACIT (fibril-associated collagens with interrupted triple-helices) family, contains molecules that appear to be associated with cross-striated fibrils composed of members of the fibrillar collagen family. We have determined a portion of the primary structure of a recently discovered member of the FACIT family, chicken alpha 1(XIV) collagen, based on cloning and sequencing cDNAs. A synthetic oligopeptide from within the carboxy-terminal non-triple-helical domain of the alpha 1(XIV) chain has been used for generating specific polyclonal antibodies. The antiserum, PS1, recognizes a 220 kDa polypeptide in immunoblots of extracts of chicken skin, tendons, and cartilage. Sequencing of a tryptic peptide generated from purified, immunoreactive material, gives a sequence identical to that derived from cDNA sequencing, providing strong support for the type XIV-specificity of PS1. We have examined the expression of type XIV collagen in developing chick embryos by immunostaining of sections from 12-day-old embryos with PS1 and by Northern blot analysis of RNA from several tissues from both 12- and 17-day-old embryos. The results show that type XIV collagen is prevalent within relatively dense connective tissues such as dermis, tendons, perichondrium, perimysium, the stroma of lungs and liver, and blood vessels.


Membrane-associated proteoglycans produced by Sertoli cells are not randomly distributed on the cell surface. Sertoli cells in culture synthesize two membrane-associated proteoglycans (PGs) containing as glycosaminoglycan (GAG) moieties either chondroitin sulfate (CS) or CS and heparan sulfate (HS); the latter PG is, therefore, referred to as the mixed PG. To determine if these PGs are randomly distributed on the cell surface, Sertoli cell monolayers were treated with chondroitinase ABC, and then the remaining PGs were analyzed by DEAE-Sephacel chromatography. The results obtained with Sertoli cell monolayers show that the CS of the mixed PG is degraded by chondroitinase, while the CS-PG is not degraded. In contrast, chondroitinase treatment of Sertoli cells in suspension shows that both the mixed PG and the CS-PG are degraded. From this, it is inferred that the mixed PG is apically oriented and the CS-PG is basolaterally oriented. Studies of the adhesion of germ cells to Sertoli cell monolayers give further support to the apical location of the mixed PG and suggest that its HS moiety is involved in the attachment of germ cells to Sertoli cells.


Eosinophil cationic protein alters proteoglycan metabolism in human lung fibroblast cultures. Eosinophil cationic protein (ECP), a highly basic protein secreted from eosinophilic granulocytes, has been shown to take part in the inflammatory reaction. The involvement of ECP in fibroblast activation was therefore investigated in cell culture. Production of proteoglycans, hyaluronan and collagen in the presence of ECP was measured after incorporation of radioactive precursors and separation into different proteoglycan classes using gel and ion exchange chromatography and hydrophobic interaction chromatography. Proteoglycan accumulation in the cell layer was increased two- to fivefold at an ECP-concentration of 10 micrograms/ml. No effect on collagen, other proteins or hyaluronan was noted. Furthermore, no effect was observed on cell proliferation. The increased proteoglycan accumulation could be inhibited by addition of heparin or of antibodies to ECP. The effect could not be mimicked by the two basic peptides protamine and poly-L-lysine, speaking in favor of specificity. The increase in proteoglycan material was seen exclusively in the intracellular pool. No change of proteoglycans in the medium or the cell surface-associated pool was noted. The increase in the cell layer was accounted for by a two- to fivefold increase in free chains of heparan sulfate and dermatan sulfate. No change was seen in the proteoglycan pattern. No effect on proteoglycan synthesis or on endocytosis was noted. The increased accumulation of polysaccharide was caused by inhibited degradation of glycosaminoglycans. The half-lives of large and small heparan sulfate proteoglycans/glycosaminoglycans and dermatan sulfate proteoglycans/glycosaminoglycans in the cell layer are increased four- to sevenfold. We conclude that ECP inhibits proteoglycan degradation in fibroblasts, which indicates a role for the eosinophil in generation of fibrosis.


Chicken gizzard 5'-nucleotidase functions as a binding protein for the laminin/nidogen complex. Soluble and reconstituted 5'-nucleotidase were used in the binding assays to the laminin/nidogen complex. They both are shown to interact specifically and in a saturable manner with the laminin/nidogen complex using a solid-phase binding assay. Dissociation constants in the region of 10(-8) M were determined for the association of soluble and membrane-bound 5'-nucleotidase. Scatchard analysis of the binding data indicate a stoichiometry of about 2.7 of the homodimeric soluble 5'-nucleotidase to the laminin/nidogen complex. The association of 5'-nucleotidase with laminin/nidogen occurs in the absence of divalent metal ions and does not require N-linked carbohydrate moieties of both laminin/nidogen and 5'-nucleotidase. 5'-Nucleotidase also associates with isolated laminin although with reduced affinity. No binding to isolated nidogen was observed. Peptides containing the RGD sequence did not influence the binding reaction. Monoclonal and polyclonal antibodies directed against 5'-nucleotidase and laminin specifically perturb the association of the reconstituted enzyme to laminin/nidogen. Sulfated polysaccharides such as heparinsulfate and dermatansulfate modulate the interaction of 5'-nucleotidase and laminin/nidogen in a complex biphasic manner and might also regulate the binding reaction in vivo. Immunohistochemistry shows a close spatial correlation of 5'-nucleotidase and laminin also in the epithelium of the small intestine pointing to an in vivo interaction of both glycoproteins.


Detection of binding sites for biotinylated neoglycoproteins and heparin (endogenous lectins) during cerebellar ontogenesis in the rat: an ultrastructural study. In a previous paper (Kuchler et al., Eur. J. Cell Biol. 52, 87-97 (1990)), endogenous carbohydrate-binding sites were studied at the optical level during rat cerebellar development on sections of fixed tissue using synthetic tools, biotinylated neoglycoproteins, in conjunction with subsequent avidin-peroxidase staining. It was shown that these tools were capable of revealing carbohydrate-binding sites during development of the rat cerebellum. The staining pattern with the individual probes disclosed variable developmental regulation and consequently suggested that recognition processes during cerebellar development may include several types of carbohydrate determinants. However, studies at the light microscope could not give information on potential membrane-bound localization of carbohydrate-binding sites and therefore discern the possible involvement of these molecules in cell adhesion processes. Furthermore, nuclear staining was suggested at the optical level. In order to elucidate these points, we examined the localization of mannose-, fucose- and heparin-binding sites at the electron microscopic level. Ultrastructural studies demonstrate that these tools are very efficient in detecting intracellular carbohydrate-binding sites, but failed to detect most of them expressed at the cell surface when using immunocytochemical techniques for known receptors, probably because of the interaction of these carbohydrate-binding sites with endogenous membrane-bound ligands. The significance of the nuclear staining and of part of the nucleolus found with fucose-containing neoglycoprotein and of the nuclear staining found with heparin are discussed.


Fibronectin shedding by Leishmania may influence the parasite-macrophage interaction. Fibronectin (FN) is a large extracellular matrix protein involved in the endocytosis of several types of particles by different phagocytes. Here we investigated the role of FN in the entry and destruction of Leishmania amazonensis promastigotes (flagellated form) by murine resident peritoneal macrophages. We also studied the lateral mobility of this protein on the surface of the parasite cells using a immunogold technique. We compared the effects of addition and depletion of FN on infective and non-infective populations of Leishmania promastigotes. The invasion by the latter but not by the former, was increased by FN, and the uptake of these cells was more sensitive to FN depletion from the culture medium. We also observed enhanced killing of intracellular infective promastigotes upon FN addition to the macrophage cultures. Immunocytochemical localization of FN on the surface of the flagellates revealed that the parasite cells released bound FN by membrane shedding in a constitutive fashion. Therefore we conclude that FN removal by shedding may be part of a physiological mechanism by which the parasites evade intracellular destruction by host cells.


Endocytosed transferrin in African trypanosomes is delivered to lysosomes and may not be recycled. It has been shown in mammalian systems that the passage of transferrin-colloidal gold (Tf-Au) through the endocytic system is influenced by the size of the gold colloid (Neutra, M. R. et al., J. Histochem. Cytochem. 33, 1134-1144 (1985); Woods, J. W. et al., Eur. J. Cell Biol. 50, 132-143 (1989)). However, in both Trypanosoma brucei brucei and Trypanosoma congolense, widely varying sizes of Tf-Au (Tf-Au5 and Tf-Au15) have been shown to proceed to lysosomes (Webster, P., Eur. J. Cell Biol. 49, 295-302 (1989); Webster, P., D. Grab, J. Cell Biol. 106, 279-288 (1988)). Using an affinity-purified anti-bovine transferrin IgG we have demonstrated that, in both T. brucei and T. congolense, native transferrin, like Tf-Au, is found in the flagellar pocket, coated vesicles, tubular structures, and lysosome-like organelles where it appears to be concentrated. The presence of Tf in the lysosomes was confirmed in colocalization experiments using T. congolense, where native bovine transferrin colocalized with a trypanosome lysosomal marker, a cysteine protease. The data suggest that, unlike the situation in mammalian cells where most transferrin is recycled to the cell surface, in African trypanosomes transferrin is routed into lysosomes and may not, therefore, be recycled.


Microneme secretion in Coccidia: confocal laser scanning and electron microscope study of Sarcocystis muris in cell culture. A monoclonal antibody (mcab) raised against a subcellular fraction of Sarcocystis muris cystozoites was used to localize microneme antigens before, during and after invasion of cultured cells. The mcab recognized a 20 and 22 kDa protein under reducing and non-reducing conditions on Western blots and localized an antigen in cystozoites in the apical part of the parasites. Confocal laser scanning microscopy of invading cystozoites revealed the secretion of a microneme antigen at the apical tip of the parasite. The secreted microneme antigen was attached to the host cell surface at the invasion site and spread along the surface of the infected cells. Electron microscopy using immunogold labeling showed that the microneme antigen was distributed in patches on the surface of infected cells and present on infected cells more than 60 min post-infection. The function of microneme antigens during parasite-host cell interactions is discussed.


Functional and structural damage in Leishmania mexicana exposed to the cationic peptide dermaseptin. The effect of dermaseptin (DS), a 34 amino acid residue cationic peptide isolated from Phyllomedusa sauvagii skin, has been studied on promastigotes of Leishmania mexicana growing in vitro. Within 5 min of incubation in the presence of DS, the flagellated parasites lost their motility. DS inhibited promastigote growth by 50% at a concentration of 3 microM and by 100% at 10 microM. Immunocytochemical, freeze fracture, label fracture and electron microscopic observations have shown that the amphipathic peptide generates perturbations of the lipid bilayer leading to altered permeability of the surface membrane and death of the parasite.


Distribution of glutamylated alpha and beta-tubulin in mouse tissues using a specific monoclonal antibody, GT335. A monoclonal antibody (GT335) directed against polyglutamylated tubulin was obtained by immunization with a synthetic peptide which mimics the structure of the polyglutamylated site of alpha-tubulin. This peptide corresponds to the C-terminal sequence Glu441-Gly448 and was chemically modified by the addition of two glutamyl units at Glu445. The specificity of GT335 was assayed by direct and competitive enzyme-linked immunosorbent assay (ELISA) against tubulin and several synthetic peptides differing either by the structure of the added polyglutamyl chain or by their amino acid sequence. Further characterization was carried out by immunoblotting detection after one- or two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The epitope appears to be formed by at least two constituents: a basic motif of monoglutamylation which is retained in the polyglutamylated forms independent of their degree of glutamylation, and some elements of the polypeptide chain close to the site of glutamylation. Given the specificity of GT335 and the delineation of its epitope, our results indicate that, in addition to alpha and beta' (class III)-tubulin, other beta-tubulin isotypes are also glutamylated. This antibody has been used to analyze the cell and tissue distributions of glutamylated tubulin. In mouse brain extracts, GT335 reacts strongly with alpha-tubulin and, to a lesser extent, with beta' (class III) and beta-tubulin. The same reactivity is also observed with cultured neurons whereas astroglial cells exhibit only low levels of glutamylated tubulin. In non-nervous mouse tissues such as spleen, lung or testis, glutamylation was shown to involve only beta-tubulin, but at far lower levels than in brain.


Binding between mammalian spermatid-ectoplasmic specialization complexes and microtubules. Ectoplasmic specializations (ESs) are submembrane specializations that consist of Sertoli cell plasma membrane linked by an ordered array of actin filaments to a cisterna of endoplasmic recticulum (ESER). They are thought to function in the spermatid-Sertoli cell adhesion junction. Microtubules occur adjacent to the cytoplasmic face of the ESER and are oriented parallel to the long axis of the Sertoli cell, the direction of spermatid translocation during spermatogenesis. Our hypothesis that spermatid orientation and translocation in the seminiferous epithelium is microtubule dependent predicts that microtubules bind to ESs. To test for binding between microtubules and ESs, we have developed an in vitro assay in which spermatid-ES complexes were isolated from the seminiferous epithelium and incubated with bovine brain microtubules that were labeled with [3H]GTP and stabilized with taxol. Binding was determined by scintillation counts from gradient fractions enriched for spermatid-ES complexes and depleted of unbound microtubules by differential centrifugation. Our data indicate that microtubules bind to spermatid-ES complexes in a substrate concentration-dependent manner and can be released with 5 mM GTP or 10 mM MgATP. Binding is competitively reduced with excess unlabeled microtubules and is inhibited by 100 microM vanadate and 2 mM N-ethylmaleimide (NEM). The amount of binding is unchanged by 10 microM vanadate, 2 mM erythro-(2-hydroxy-3-nonyl)adenine (EHNA) or 1 mM 5'-adenylylimidodiphosphate (AMP-PNP). Immunofluorescence and autoradiographic data confirm that labeled microtubules bind to ES locations on spermatid-ES complexes. These data are consistent with the hypothesis that spermatid translocation is a microtubule-based transport event.


Interleukin-1 is a motility factor for human breast carcinoma cells in vitro: additive effect with interleukin-6. Interleukin-1 beta (Il-1 beta) and interleukin-1 alpha (Il-1 alpha) were shown to act as motility factors for the human breast carcinoma cell lines SK-BR-3 and ZR-75-1 in vitro. Both cytokines induced transition from the stationary to the motile phenotype (spreading). Il-1 beta stimulated translocation, shape change and random migration (chemokinesis) of SK-BR-3 cells as demonstrated by time-lapse video recordings and by a modified Boyden chamber assay. Interleukin-6 (Il-6) stimulated spreading of the SK-BR-3 cells; an additive effect with Il-1 beta on spreading and fast plasma membrane movements was evidenced. In the SK-BR-3 cell line, the signal transduction of Il-1 beta and Il-6 differed, since only the effect of Il-6 on spreading was sensitive to pertussis toxin. Both Il-1 beta and Il-6 required protein synthesis to stimulate spreading, since cycloheximide inhibited the effect of the cytokines. Induction of an autocrine loop of Il-6 in the SK-BR-3 cells by Il-1 beta was unlikely, since after stimulation with Il-1 beta, no induction of Il-6 activity was measured, nor was inhibition of stimulated spreading seen in the presence of an antiserum against Il-6. Addition of Il-8 or of an antiserum against Il-8 did not affect spreading. We concluded that Il-1 and Il-6 could act as motility factors for human breast carcinoma cells, in both an independent and an additive way.(ABSTRACT TRUNCATED AT 250 WORDS)


Interleukin-1 from baboon peripheral blood monocytes: altered response to endotoxin (lipopolysaccharide) and Staphylococcus aureus stimulation compared with human monocytes. The baboon Papio ursinus does not elicit a febrile response upon injection with endotoxin, but fever is produced when injected with Staphylococcus aureus particles (Zurowsky, Y., H. Laburn, D. Mitchell, Can. J. Physiol. Pharmacol. 65, 1402-1407 (1987)). We address the question whether baboon peripheral blood monocytes produce interleukin-1 (IL-1) when stimulated with endotoxin or S. aureus particles in culture. Results show that little IL-1 biological activity was produced from endotoxin-stimulated baboon peripheral blood monocytes, compared with S. aureus-stimulated cells. Measurements of IL-1 beta by radioimmunoassay supported these data. This is contrary to data from human monocytes, which show greater sensitivity to endotoxin. Examination of IL-1 beta mRNA from endotoxin-stimulated and S. aureus-stimulated baboon monocytes, however, showed that more mRNA for IL-1 beta was present in endotoxin-stimulated monocytes than in cells stimulated with S. aureus. This illustrates the possibility that the production and/or the secretion of IL-1 beta is not as efficient in baboon monocytes as it is in human monocytes.


Cardiac pacing and aviation.

Cardiac pacing and aviation. Certain applicants with stable disturbances of rhythm or conduction requiring cardiac pacing, in whom no other disqualifying condition is present, may be considered fit for medical certification restricted to multi-crew operations. The reliability of modern pacing systems appears adequate to permit restricted certification even in pacemaker dependent subjects except for certain models of pacemakers and leads known to be at increased risk of failure. These are to be avoided. There is little evidence to suggest that newer devices are any more reliable than their predecessors. Single and dual chamber systems appear to have similar reliability up to 4 years, after which time significant attrition of dual chamber devices occurs, principally due to battery depletion. All devices require increased scrutiny as they approach their end of life as predicted from longevity data and pacing characteristics. Unipolar and bipolar leads are of similar reliability, apart from a number of specific bipolar polyurethane leads which have been identified. Atrial leads, particularly those without active fixation, are less secure than ventricular leads and applicants who are dependent on atrial sensing or pacing should be denied certification. Bipolar leads are to be preferred due to the lower risk of myopotential and exogenous EMI. Sensor-driven adaptive-rate pacing systems using active sensors may have reduced longevity and require close scrutiny. Activity-sensing devices using piezoelectric crystal sensors may be subject to significant rate rises in rotary wing aircraft. The impracticality of restricted certification in helicopters will, in any event, preclude certification. Such devices would best be avoided in hovercraft (air cushioned vehicle) pilots. Only minor rate rises are likely in fixed-wing aircraft which are unlikely to be of significance. Anti-tachycardia devices and implanted defibrillators are inconsistent with any form of certification to fly.


Hypertension and the probability of an incapacitating event over a defined period: impact of treatment. (1) The risks of coronary heart disease, cerebrovascular disease and all-cause mortality associated with increasing levels of pressure are graded and continuous from the lowest to the highest levels. (2) Data from several large prospective studies allow evaluation of individual risk based on blood pressure level but may require modification in the context of aircrew. (3) Because cardiovascular risk factors appear to interact and 'cluster' in hypertensives, a broadened approach to the evaluation of risk for the individual and the management of hypertension is necessary and appropriate. (4) Anti-hypertensive treatment has been shown in trials to reduce the incidence of stroke but appears much less effective at reducing coronary events. It may be that a management policy which involves an assessment of and intervention on all risk factors together, incorporating the use of anti-hypertensive drugs which do not have adverse metabolic effects will be more effective in this context. Evaluation of such a policy in a long-term morbidity and mortality trial is however urgently required.


Late results following coronary artery bypass grafting. Coronary bypass surgery is well into its third decade. The randomized trials of saphenous vein grafting together with the various registries[57-60] have provided us with a wealth of information not only on the effects of surgery but also on the natural history of coronary heart disease itself. Numerous improvements have been introduced, the most notable being the use of the IMA as an arterial conduit. Thus the results of the randomized trials which significantly influence our clinical decisions may not accurately reflect what modern surgery can now offer, especially to the type of patient being operated upon in the 1970s. Nevertheless the decision about whom to operate on probably will not change, at least in terms of clinical variables affected by the coronary anatomy and left ventricular function. But there is every expectation that the long-term clinical results of surgery will be better since graft patency has already been shown to have improved as a result of anti-platelet therapy and, most of all, by the IMA. We will never have a randomized trial to prove this, but experience to date justifies this conclusion. The other great change that has occurred during the last decade is angioplasty and hopefully the randomized trials will put this technique in perspective. But practice has already changed and surgery for single vessel disease is now much less commonly performed given the greater appreciation of the good prognosis with which this lesion is associated and the ease with which angioplasty can alleviate the symptoms it causes.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of penicillin on the clinical course of streptococcal pharyngitis in general practice. The aim of the study was to explore whether penicillin was superior to placebo in altering the clinical course of proven streptococcal pharyngitis. A randomised, parallel, double blind placebo controlled trial of 10 days duration was undertaken in 42 general practices in the Gent region (Flemish part of Belgium). Phenoxymethylpenicillin (adults 250 mg t.i.d. and children 125 mg t.i.d.) or placebo were administrated to 173 patients, aged 5 to 50 y, with acute sore throat and a positive culture for Group A beta-haemolytic streptococci. Penicillin and placebo tablets were identical. Patient compliance was monitored by assay of penicillin in urine (Sarcina lutea method). The primary outcome variable was sore throat as recorded by the physician on Day 3. The experiences of the patients themselves over the 10 day period were also assessed. Secondary outcome variables were other local and general symptoms and signs of streptococcal throat infection. In the penicillin group on Day 3, 23.2% of the patients still complained of sore throat versus 65.9% in the placebo group: difference 42.7% (C.I. 29.4%, 56.1%). This finding was confirmed by survival analysis of the symptom 'sore throat', as recorded by the patients. The physicians recorded on Day 3 a significant positive effect on another symptom (malaise: P < 0.04) and certain clinical signs (abnormal throat: P < 0.07; and redness of throat: P < 0.003). Penicillin had more adverse effects than placebo (P < 0.007). It also inhibited the rise in ASLO (P < 0.001). In this study in general practice, penicillin had a slight but definitive positive effect on the clinical evolution of streptococcal pharyngitis.(ABSTRACT TRUNCATED AT 250 WORDS)


24-hour anti-ischaemic action with once daily nifedipine. Experience obtained with a fatty-alcohol matrix tablet in patients with coronary artery disease. The ability of a fatty-alcohol matrix, slow-release tablet of nifedipine 60 mg to maintain a 24-hour anti-ischaemic action in the fixed dose of 60 mg once daily has been investigated in a randomised, placebo-controlled, double-blind trial. 12 normotensive patients with angiographically proven coronary artery disease (stenosis of at least one major vessel > or = 70%) were studied. The anti-ischaemic response was assessed over a period of 4 days as changes in the exercise-induced ST-segment depression 6 h and 24 h post-dose, and ST-segment changes in 24-h ambulatory ECGs. A measurable anti-ischaemic response was observed in 8 of the 12 patients. Exercise-induced ST-segment depression 6 h after the administration of nifedipine was reduced by 30% compared to placebo, and there was still a measurable anti-ischaemic response 24-h post-dosing. Both responses were independent of changes in exercise blood pressure. In 7 patients with ischaemic episodes in the 24-h ECGs, nifedipine treatment had only a minor effect on the intensity and duration of ischaemia. It is concluded that a significant anti-ischaemic effect lasting 24 h could be demonstrated using effort-induced ST-segment changes in patients with angiographically proven coronary heart disease, who were treated once daily with nifedipine 60 mg as a fatty-alcohol slow release tablet.


Salmeterol protects against hyperventilation-induced bronchoconstriction over 12 hours. To study the dose-response relationship of salmeterol for protection against a naturally occurring stimulus, isocapnic hyperventilation tests of cold air were done in 16 asthmatic patients. The subjects inhaled either 50 micrograms salmeterol, salbutamol 200 micrograms, or placebo in a double-blind, randomised, cross-over study. The FEV1 was measured prior to medication and the provocative ventilation (PV20) required to induce a 20% fall in FEV1 was calculated by linear interpolation from ventilation-response curves obtained 0.5, 4, 8, and 12 h after medication. Following salbutamol, the mean FEV1 were 4.11, 3.89, 3.58, and 3.55 l, with a significant difference from placebo up to 4 h. Following salmeterol, mean FEV1 values were 3.95, 4.10, 3.93, and 3.88 l, with a significant difference from placebo up to 12 h. The mean PV20FEV1 after salbutamol was 78.8, 58.5, 52.7, and 48.4 l.min-1, the 0.5 h value being significantly different from placebo. After salmeterol, the mean PV20FEV1 values were 84.6, 82.5, 67.8, and 65.8 l.min-1, with a significant difference from placebo up to 12 h. We conclude that, besides its long-lasting bronchodilating effect, salmeterol protects against hyperventilation-induced bronchoconstriction for at least 12 h.


The effects of acute and repeated doses of zolpidem on subjective sleep, psychomotor performance and cognitive function in elderly volunteers. We gave 24 healthy elderly volunteers with a perceived sleep onset of at least 30 minutes zolpidem 5 mg, zolpidem 10 mg, or placebo for 7 days in a double-blind, three-way, crossover study. The morning after nocturnal dosing, psychomotor performance and cognitive ability were measured using tests which are sensitive to the residual effects of hypnotics and to the effects of drugs on various indicators of sleep quality. The tests were: Choice Reaction Time; Tracking; Critical Flicker Fusion Threshold; Memory Scanning; Word Recognition; the Leeds Sleep Evaluation Questionnaire and Line Analogue Rating Scales. Zolpidem produced a subjective improvement in sleep but did not impair performance the following day. Furthermore, during repeated administration, there was no tolerance to the effects of sleep latency and quality of sleep, nor adverse effects on task performance.


The effects of temazepam and ethanol on human psychomotor performance. We have studied the effects of temazepam, alone and in combination with ethanol, on psychomotor performance in six healthy men and women using a battery of five microcomputer-based tasks before and 30, 90, and 150 min after treatment. The tests were pursuit tracking, divided attention, two four-choice reaction time tests and tapping rate. The entire battery required 25 min. The subjects also reported their mood at each testing time using a computerized bipolar mood scales test. Temazepam (15 mg) plus ethanol (peak blood concentration of 11 mmol.l-1) significantly impaired divided attention, tracking, and reaction time over a 3 h period. There was significant impairment versus placebo for each drug alone on some of the tests. Plasma and urine concentrations of temazepam and temazepam glucuronide were measured, but there was no significant temporal correlation between impairment and drug or metabolite concentration in either plasma or urine. The subjects knew when they had taken ethanol, but could not discriminate temazepam from ethanol whether alone or in combination. The subjects rated their performance similarly after each of the four treatment conditions. The performance on the tracking, divided attention, and PAB reaction time tasks used in this study was impaired by a combination of temazepam and ethanol in doses which may not cause impairment when each is given alone.


Prevalence of drug-treated diabetes mellitus in Belgium. Results of a study with the collaboration of a network of pharmacies. Within the framework of a European concerted action on diabetes mellitus (EURODIAB SubArea C), an epidemiological study was established in Belgium in 1990 in order to estimate the prevalence of drug-treated diabetes mellitus. An assessment was made of the sales of insulin and oral antidiabetic drugs and the average daily dose used. A sample of people with diabetes, clients of 107 pharmacies, provided the data to establish average daily doses. Those pharmacies, spread over the 9 provinces of the country, represent 2% of all private pharmacies in Belgium. Over a 2 month period each pharmacist presented a questionnaire to each client receiving an antidiabetic drug. In 1990, 164 per 10,000 inhabitants were treated with antidiabetic drugs, which means that there were approximately 163,000 drug-treated diabetics in Belgium. At the time of the survey 65% of the diabetics in the sample were 60 years or older. Overall, 38% of drug-treated diabetics took insulin, and 30% of them took only human insulin. Treatment type varied by the province where the pharmacy was located. The provinces of Hainaut and Luxembourg-Namur had a higher percentage of diabetics on oral treatment. This is the first description in Belgium of the prevalence of drug-treated diabetes and of the pattern of prescribing of these drugs.


Acetylator phenotypes of Jordanian diabetics. The acetylator phenotype was determined in 31 insulin-dependent (IDDM) and 110 noninsulin-dependent (NIDDM) Jordanian diabetics, and was compared to that of 160 healthy volunteers of the same ethnic group. Dapsone was used as the test drug. The rapid acetylator phenotype was slightly less frequent in IDDM and slightly more frequent in NIDDM. Neither of the differences was significant. When acetylator status in the two types of diabetes mellitus was compared, there was a significant difference among the two groups. Patients with IDDM had a higher percentage of the slow acetylator phenotype when compared to NIDDM patients. The association between acetylator status and IDDM in Jordanians, which agrees with that reported for the Saudi Arabian population, is the reverse of what is found in European populations. The results demonstrate ethnic differences in acetylator status among IDDM patients.


Heating and cooling of the nitroglycerin patch application area modify the plasma level of nitroglycerin. 19 healthy volunteers wore a nitroglycerin patch releasing 10 mg per 24 h for 2 h. Subsequently, the skin area surrounding the patch was exposed to 15 min of local heating with an infrared bulb (Group A, n = 10), or local cooling with an ice-pack (Group B, n = 9). The patch was protected by an insulating shield (Styrofoam). After 10 min of heating, the median (Walsh) plasma nitroglycerin level increased from 3.1 to 7.6 nmol.l-1. Body temperature remained constant. After 15 min of cooling the median plasma level had dropped from 2.1 to 1.4 nmol.l-1. The results demonstrate that changes in skin temperature may cause extensive short-term changes in the bioavailability of nitroglycerin. Presumably, a subcutaneous or cutaneous reservoir builds up during transdermal treatment, and changes in regional cutaneous blood flow affect the rate of drainage from the reservoir into the systemic circulation.


The sensitivity of human blood platelets to the aggregating agent ADP during different dietary sodium intakes in healthy men. We have investigated the effect of varying sodium intake on the renin-angiotensin system, ADP-induced platelet aggregation in vitro, and blood 5-HT concentrations in 9 male volunteers. Systolic blood pressure was slightly reduced during a low sodium diet, whereas the diastolic pressure remained unchanged. Plasma renin activity and aldosterone concentration both fell significantly when sodium intake was increased; plasma angiotensin II concentration also fell, but not significantly. There was a significant fall in haematocrit after an increased sodium intake, but there was no change in the whole-blood platelet count after correcting for this. There were no significant changes in either total (i.e. PRP) or platelet 5-HT concentrations. The extent of platelet aggregation induced by 5 and 20 mumol.l-1 of ADP increased significantly when dietary sodium intake was increased. When compared with low or normal sodium intakes, lower concentrations of ADP were required to produce 50% of maximum aggregation after a high sodium intake. The 5-HT2 receptor antagonist ketanserin (1 mumol.l-1 in vitro) reduced the extent of aggregation induced by 5 mumol.l-1 ADP after the volunteers had taken a high sodium diet, whereas the angiotensin II receptor antagonist saralasin (1 nmol.l-1) increased the rate of aggregation after the low sodium diet. Thus, during a high sodium intake, human platelets become more sensitive to the aggregating agent ADP. It is possible that this effect is mediated via platelet 5-HT2 receptors, since ketanserin abolished the increase in salt-induced aggregation seen with 5 mumol.l-1 ADP.


Failure of N-acetylcysteine to reduce low-density lipoprotein oxidizability in healthy subjects. We have studied the effects of N-acetylcysteine, which is thought to have antioxidant properties, on the susceptibility of low-density lipoprotein to oxidation and on whole-blood glutathione concentrations in six healthy volunteers. N-acetylcysteine was given orally in a dosage of at 1.2 g per day for 4 weeks, followed by 2.4 g per day for a further two weeks. The susceptibility of low-density lipoprotein to in vitro Cu(2+)-oxidation was determined by continuously measuring the formation of conjugated dienes. Whole-blood concentrations of reduced and oxidized glutathione were also determined. N-acetylcysteine had no effect on the susceptibility of LDL to oxidation. Concentrations of vitamin E in the serum and in low-density lipoprotein were not changed. Compared with controls the concentration of glutathione in N-acetylcysteine treated subjects was reduced (-48%) and the concentration of oxidized glutathione was higher (+80%). The GSH/GSSG-ratio, a marker of oxidative stress was 83% lower. The results do not support the supposed antioxidative action of N-acetylcysteine. It seems more likely that N-acetylcysteine acts as a pro-oxidant in the dosage used.


Influence of oral contraceptive agents on kidney function and protein metabolism. The present study was an investigation of the effect of oral contraceptives on kidney function as well as a brief examination of protein metabolism, since glomerular filtration rate depends to a large extent on daily protein intake. 28 healthy women not taking contraceptives and 46 healthy women (aged 20-28 y) on one of three different types of oral contraceptive (combination preparations) were investigated [Minulet/Femovan, Marvelon, Diane]. In all groups on oral contraceptives the endogenous creatinine clearance was significantly increased. The potassium excretion rate was significantly elevated in the groups taking Marvelon and Diane, and the sodium excretion rate was significantly increased in those on Minulet/Femovan and Diane. In all groups on contraceptives the albumin excretion rate was numerically but not significantly elevated. No significant differences were found in the daily oral protein intake or the nitrogen excretion rate on comparing the groups taking contraceptives with the control group. However, the ratio nitrogen excretion rate/daily protein intake was significantly increased in those on Minulet/Femovan and Diane. The study has shown that besides their various effects on renal tubular function, oral contraceptives are able to increase the glomerular filtration rate, and certain types have a protein catabolic effect.


Pharmacokinetics and effects of atrial natriuretic factor during hypothermic cardiopulmonary bypass. The pharmacokinetics of a bolus dose of synthetic atrial natriuretic factor (ANF) 50 micrograms and its effects on urine output, blood pressure and plasma renin activity have been studied in 5 patients undergoing hypothermic cardiopulmonary bypass for cardiac surgery. The half-lives of the fast and slow components were 2.4 min and 14.2 min, respectively. The volume of the central compartment was 16.7 l and the volume of distribution at steady-state was 38.9 l. The total plasma clearance was 3.8 l.min-1. ANF significantly increased urine output and decreased blood pressure, but it did not affect plasma renin activity.


Yohimbine pharmacokinetics and interaction with the sympathetic nervous system in normal volunteers. The pharmacokinetics of yohimbine and its effects on sympathoadrenal function were studied in 13 young, healthy, male volunteers after an IV bolus dose of 0.25 or 0.5 mg.kg-1. Pharmacokinetic analysis showed that distribution was rapid, with a half life between 0.4 and 18 min, and the elimination half life ranged between 0.25 and 2.5 h. The volume of distribution (Vss) was 74 l, (range 26 to 127 l). Only 0.5 to 1% of unchanged yohimbine was found in the urine, indicating that the major part of the drug was eliminated by hepatic clearance. Total plasma clearance was 117 l.h-1, which exceeds the hepatic plasma flow. This means that yohimbine is a high extraction drug with considerable extra-hepatic metabolism. Fractional urine sampling revealed that 0.5-1% of unchanged yohimbine was excreted in urine in a biphasic manner. The data also suggested the existence of a slower elimination phase, with a half life of 13 h. The venous plasma concentration of noradrenaline (NA) increased 3-fold within 15 min after the yohimbine injection while plasma adrenaline (A) and neuropeptide Y-like immunoreactivity (NPY-LI) remained unchanged. The plasma concentration-effect relationship of the changes in circulating NA followed counter-clockwise hysteresis. The results show that the hyperadrenergic state elicited by therapeutic doses of the alpha 2-adrenergic autoreceptor antagonist, yohimbine, is due to an interaction with NA but not to release of A or NPY in man.


Pharmacokinetics of temocapril hydrochloride, a novel angiotensin converting enzyme inhibitor, in renal insufficiency. The pharmacokinetics of temocapril hydrochloride, a novel prodrug-type angiotensin-I converting enzyme (ACE) inhibitor, has been studied in patients with mild (Group II) to severe (Group III) renal insufficiency in comparison with subjects with normal renal function (Group I). The pharmacokinetic parameters of the active diacid metabolite, including Cmax, AUC and half-life (t1/2), showed only slight changes between the three groups: AUC (0-inaffinity) was significantly larger in Group III than Group I, and t1/2 tended to be prolonged in Group III, but the change was not significant. The urinary recovery of the diacid was significantly decreased in Group III. (Group I, 28.1%, Group II, 21.6%, Group III, 12.8%). Compared with other ACE inhibitors, which are mainly excreted through the kidney, the plasma concentration of the active diacid metabolite was hardly influenced by renal function. It was speculated that lowering of the dose of temocapril might be recommended only in patients with severe renal insufficiency.


Single-dose and steady-state pharmacokinetics of sabeluzole in senile dementia of Alzheimer type patients. The single- and repeated-dose pharmacokinetics of sabeluzole have been determined in six elderly patients with [senile] dementia of the Alzheimer type. After a single oral dose of 10 mg sabeluzole, the peak plasma concentration was attained at 1 to 4 h; it averaged 42 ng.ml-1. On repeated dosing (10 mg b.d.), steady-state was virtually attained after 3 days of treatment. Steady-state mean trough and peak plasma concentrations fluctuated between 53 and 94 ng.ml-1. The mean terminal half-life after a single dose and at steady-state was of the order of 33 h. Sabeluzole was well tolerated and at the end of treatment, no systematic changes in blood haematology, biochemistry or urinalysis were seen.


The pharmacokinetics of the beta 2-adrenoceptor agonist fenoterol in healthy women. We have studied the pharmacokinetics of fenoterol in healthy women during and after a 3 h intravenous infusion of different doses within the therapeutic range for tocolysis (0.5 microgram.min-1, 1.0 micrograms.min-1, and 2.0 micrograms.min-1). A specific and sensitive radioimmunoassay was used for the determination of fenoterol. For compartmental analysis the plasma concentration time data were fitted with the TOPFIT program, assuming two exponentials. The total clearance of fenoterol increased with dose (1299 ml.min-1 at 0.5 microgram.min-1, 1483 ml.min-1 at 1.0 micrograms.min-1, and 1924 ml.min-1 at 2.0 micrograms.min-1), as did the apparent volume of distribution (from 49 l at the lowest to 85 l at the highest dose). In contrast, the apparent half-lives were not dose-dependent, with t1/2.lambda 1 4.8 min and t1/2.lambda z 52 min.


TGF-beta 3 protects normal human hematopoietic progenitor cells treated with 4-hydroperoxycyclophosphamide in vitro. In this study we have investigated the ability of transforming growth factor-beta 3 (TGF-beta 3, 1000 pM) to protect hematopoietic bone marrow (BM) progenitor cells from the cytotoxic activity of 4-hydroperoxycyclophosphamide (4-HC, 100 microM) in vitro. Hematopoietic progenitors were purified by negative depletion of accessory and maturing cells or enriched by positive (CD 34+ cells) selection. For comparison the same treatment was tested on three different lymphoid cell lines CEM, SK-DHL-2, and LY-16. The experimental protocol was designed to mimic ex vivo purging conditions. Therefore, tumor cells and enriched hematopoietic precursors were mixed with irradiated BM cells. Our results demonstrated that preincubation of enriched progenitor cells with TGF-beta 3 for up to 72 h followed by 4-HC treatment resulted in an increased survival of colonies derived from granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) colony-forming cells, whereas a substantially lower number of colonies was observed in the control group. Similar results were observed when BM cells were first treated with 4-HC followed by TGF-beta 3 incubation for 24 or 48 h. In contrast, TGF-beta 3 provided no protection to the 4-HC cytotoxicity toward the lymphoma and leukemia cell lines. Three to four log of tumor cell killing was induced by 4-HC in the presence or absence of preincubation with TGF-beta 3. These data suggest that TGF-beta 3 is able to protect normal BM progenitors from the cytotoxic activity of an alkylating agent (4-HC) in vitro, whereas it does not offer any protection to lymphoma cell lines. These findings will have important implications for developing better purging conditions for autologous GM transplantation.


Hematopoietic growth factors in anemia of Belgrade laboratory (b/b) rats. In this study, the extent to which growth factor production and microenvironment might be responsible for defective erythropoiesis and granulopoiesis in anemic b/b rats is investigated. Radioimmunoassay-determined serum erythropoietin (Epo) levels are high in b/b rats and closely related to degree of anemia. The low number of erythroid progenitors in b/b rats despite a high Epo level suggested that the defective erythropoiesis could be due to a low level of burst-promoting activity (BPA). A pokeweed mitogen-stimulated medium (PWM-SCM) was prepared with b/b rat spleen cells and used in normal and anemic rat bone marrow and spleen cultures to determine BPA and other growth factor levels. No erythroid burst-forming unit-derived colonies were found but granulocyte-macrophage colony-forming units were counted in significant number, suggesting that the production of growth factors that supports the growth of granulopoietic progenitors is not significantly disturbed. Because BPA is produced mainly by T-lymphocytes, the low BPA level in b/b rat PWM-SCM raised the question of the functional capacity of T-lymphocytes. Investigations showed a decrease in the proliferative activity of b/b rat spleen mitogen-activated T-lymphocytes to about 20% of controls as well as a decrease in interleukin-2 activity in b/b rat spleen cell supernatants. These results point to defective T-lymphocytes. A study of bone marrow fibroblastoid cell colonies (CFU-F) revealed significantly lower CFU-F counts in the b/b rats. This finding is indicative of a disturbed microenvironment, which could also to some extent be responsible for decreased growth factor production and depressed hematopoiesis in the b/b rat.


Synthesis and deposition of glycosaminoglycans in the murine hemopoietic stromal line S17: modulators of the hemopoietic microenvironment. The murine hemopoietic stromal cell line S17 can support either myelopoiesis or lymphopoiesis depending on the culture conditions (i.e., the presence of steroid or mercaptoethanol). The glycosaminoglycans are important components of the extracellular matrix, which influence hemopoietic cell proliferation. Accordingly, glycosaminoglycans have been compared under different growth conditions. Under myeloid conditions (with steroid) a higher proportion of the sulfated glycosaminoglycans was incorporated into the cell layer and the extracellular matrix was increased, whereas synthesis was reduced under lymphoid conditions (with mercaptoethanol). The inclusion of steroid or mercaptoethanol did not alter the nature of the heparan sulfate synthesized as shown by DEAE anion-exchange chromatography, cleavage with specific enzymes and resolution of the digestion products by gel electrophoresis (oligomapping), and glycosaminoglycan size. The major species of sulfated proteoglycan synthesized under the different growth conditions (200 and 110 kd for the culture supernatant and 110, 71, and 38 kd for the cell layer) were shown to be very similar by polyacrylamide gel electrophoresis. Although no qualitative difference was found biochemically between the major glycosaminoglycans/proteoglycans, scanning electron microscopy revealed major differences in the pattern of deposition of the glycosaminoglycans. Under myeloid conditions, a rich fibrous matrix covered the cell layer, whereas under lymphoid conditions glycosaminoglycan was sparsely deposited. The arrangement of the extracellular matrix may have important consequences for myelo- and lymphopoiesis.


Pluripotent hematopoietic stem cells of low and high density can repopulate W/Wv mice. We have studied several features of pluripotent hematopoietic stem cells (PHSC) and day-12 spleen colony-forming units (CFU-S12) in murine bone marrow. C57BL/6J marrow cell suspensions were separated by elutriation and fractions were obtained at flow rates (FR) of 25 ml/min, 29/30 ml/min, 35 ml/min, and with the rotor off. All four fractions contained PHSC that could repopulate W/Wv mice, but significant numbers of CFU-S12 were found only in the three higher FR fractions. Cells in the FR29/30 fraction were shown to have almost three-fold more repopulating activity than fresh marrow in a competitive repopulation assay. The PHSC in fractions separated by elutriation were enriched by depleting cells expressing specific lineage markers with monoclonal antibodies and magnetic immunobeads. As few as 10(4) lineage negative (lin-) cells from FR35 or 10(5) lin--cells from FR25 conferred long-term multilineage repopulation in W/Wv mice, as demonstrated by Southern blot analysis of DNA from recipient thymus and bone marrow. We conclude that PHSC are heterogeneous for cell size and density and that the highest concentration of PHSC resides in the subset of intermediate density present in the FR29/30 fraction.


Constitutive expression of a megakaryocytic functional property by murine erythroleukemia (Friend) cells: the incorporation of serotonin. Murine Friend-derived erythroleukemia cells (MEL) are generally believed to be unipotential progenitors inducible to terminal erythroid differentiation. However, we found that MEL can constitutively incorporate significant amounts of radiolabeled serotonin ([3H]5-HT). Because this process is typical of cells belonging to the megakaryocytic lineage, we investigated the significance and mechanisms of 5-HT incorporation in the MEL system. We observed that: 1) normal murine erythroid cells and erythroid progenitors do not incorporate [3H]5-HT, as well as normal murine myeloid cells and the human myeloid cell line HL-60; on the other hand, the human erythroleukemia cell lines K562 and HEL, which have been shown to constitutively express megakaryocytic features, were able to incorporate [3H]5-HT; 2) MEL incorporated 5-HT by an active and saturable mechanism, dependent on temperature and sodium concentration in the medium; and 3) 5-HT uptake was very rapid. Moreover, because about 65% of cell-associated radioactivity was no longer displaced by the cold substrate, we assumed it to represent "true" cytoplasmic internalization. Finally, 5-HT incorporation by MEL was inhibited by clomipramine, ouabain, and reserpine, which are known inhibitors of 5-HT uptake in platelets. The commitment of MEL to terminal erythroid differentiation by hexamethylene bisacetamide or dimethyl sulfoxide greatly reduced the capacity to incorporate [3H]5-HT. These results seem to suggest that the MEL system, although mainly erythroid as regards its differentiation capability, constitutively expresses features of the megakaryocytic lineage, possibly disclosed by the ability to incorporate 5-HT. This hypothesis was further supported by the findings that 30%-40% of uninduced MEL were labeled by a polyclonal antibody raised against murine platelets that selectively recognized megakaryocytes in murine bone marrow smears.


The effect of AS101 on the reconstitution of T-cell reactivity following irradiation or cyclophosphamide treatment. AS101 (ammonium trichloro[dioxyethylene-O-O']tellurate) is a new synthetic compound previously described by us as having immunomodulating properties and minimal toxicity. Phase II clinical trials are currently in progress with AS101 on cancer patients. AS101 has been recently found to have both radioprotective and chemoprotective effects on hemopoiesis of irradiated mice or mice treated with cyclophosphamide (CYP). In this study the effect of AS101 on the recovery of the immune system from sublethal irradiation or CYP treatment was assessed. Mice were injected once with AS101 24 h before being irradiated with 450 cGy or treated with 250 mg/kg body weight CYP. At various time points after treatment the functional capacity of the immune system was determined. It was found that AS101 could significantly reduce the decrease in the number of spleen cells and thymocytes, the decrease in the proliferation rate of these cells to the T-cell mitogen concanavalin A, and the decrease of interleukin 2 secretion by spleen cells. AS101 could initially protect these functions because they were increased over control levels immediately 24 h after treatment. AS101 was also shown to normalize the distribution of T-cell subsets that was impaired following both treatments. These results suggest an immunoregulatory role for AS101 in counteracting chemotherapy and radiation-induced immunological suppression as well as its usefulness as an adjunct treatment of cancer when used in combination with CYP or irradiation.


Trigeminal excitation of dorsal neck motoneurones in the cat. Excitation of dorsal neck motoneurones evoked by electrical stimulation of primary trigeminal afferents in the Gasserian ganglion has been investigated with intracellular recording from alpha-motoneurones in the cat. Single stimulation in the Gasserian ganglion ipsi- and contralateral to the recording side evoked excitatory postsynaptic potentials (EPSPs) in motoneurones innervating the lateral head flexor muscle splenius (SPL) and the head elevator muscles biventer cervicis and complexus (BCC). The gasserian EPSPs were composed of early and late components which gave the EPSPs a hump-like shape. A short train of stimuli, consisting of two to three volleys, evoked temporal facilitation of both the early and late EPSP components. The latencies of the gasserian EPSPs ranged from 1.6 to 3.6 ms in SPL motoneurones and from 1.6 to 5.8 ms among BCC motoneurones. A rather similar latency distribution between 1.6 and 2.4 ms was found for ipsi- and contralateral EPSPs in SPL and BCC motoneurones, which is compatible with a minimal disynaptic linkage between primary trigeminal afferents and neck motoneurones. Systematic transections of the ipsi- and contralateral trigeminal tracts were performed in the brain stem between 3 and 12 mm rostral to the level of obex. The results demonstrate that both the ipsi- and contralateral disynaptic and late gasserian EPSPs can be mediated via trigeminospinal neurones which take their origin in the nucleus trigeminalis spinalis oralis. Transection of the midline showed that the contralateral trigeminospinal neurones cross in the brain stem. Systematic tracking in and around the ipsilateral trigeminal nuclei demonstrated that the axons of ipsilateral trigeminospinal neurones descend just medial to and/or in the medial part of the nucleus. Spinal cord lesions revealed a location of the axons of the ipsilateral trigeminospinal neurones in the lateral and ventral funiculi. Interaction between the ipsi- and contralateral gasserian EPSPs showed complete summation of the disynaptic EPSP component, while the late components were occluded by about 45%. These results show that the disynaptic EPSPs are mediated by separate trigeminospinal neurones from the ipsi- and contralateral side, while about half of the late EPSPs are mediated by common neurones which receive strong bilateral excitation from commissural neurones in the trigeminal nuclei. Spatial facilitation was found in the late gasserian EPSP but not in the disynaptic gasserian EPSP by conditioning stimulation of cortico- and tectofugal fibres. Disynaptic pyramidal and tectal EPSPs, which are mediated by reticulospinal neurones, were facilitated by a single stimulation in the gasserian ganglion at an optimal interval of 2 ms.(ABSTRACT TRUNCATED AT 400 WORDS)


Anatomical pathways from the optic tectum to the spinal cord subserving orienting movements in the barn owl. Electrical stimulation of the optic tectum in many vertebrate species elicits eye, head or body orienting movements in the direction of the receptive field location recorded at the site of stimulation; in the barn owl, tectal stimulation produces short latency saccadic head movements (du Lac and Knudsen 1990). However, the barn owl, like other avians, lacks a direct projection from the tectum to the spinal cord, implying that less direct connections underlie tectally mediated head movements. In order to determine the pathways by which the tectum gains access to spinal cord circuitry, we searched for overlap regions between tectal efferent projections and the locations of cells afferent to the spinal cord. Tectal efferent pathways and terminal fields were revealed by anterograde labeling using horseradish peroxidase (HRP) or tritiated amino acids injected into the optic tectum. Cells afferent to the spinal cord were identified by means of retrograde labeling using HRP, rhodamine, or rhodamine-coupled latex beads injected into the cervical spinal cord. A comparison of results from the anterograde and retrograde labeling experiments demonstrated several areas of overlap. All of the cell groups that both received heavy tectal input and contained a high proportion of cells projecting to the spinal cord were located in the medial half of the midbrain and rhombencephalic tegmentum, and included the red nucleus, the interstitial nucleus of Cajal, the medial reticular formation, the nucleus reticularis pontis giganto-cellularis, and the nucleus reticularis pontis oralis. All of these cell groups receive their tectal input from the medial efferent pathway, one of three major output pathways from the tectum. The other two output pathways (the rostral and the caudal) project to regions containing no more than a few scattered cells that are afferent to the spinal cord. Based on these data and on the functions of homologous cell groups in other vertebrates, we hypothesize that the medial efferent pathway and its brainstem target nuclei are primarily responsible for tectally mediated orienting head movements in the barn owl.


Neural basis for eye velocity generation in the vestibular nuclei of alert monkeys during off-vertical axis rotation. Activity of "vestibular only" (VO) and "vestibular plus saccade" (VPS) units was recorded in the rostral part of the medial vestibular nucleus and caudal part of the superior vestibular nucleus of alert rhesus monkeys. By estimating the "null axes" of recorded units (n = 79), the optimal plane of activation was approximately the mean plane of reciprocal semicircular canals, i.e., lateral canals, left anterior-right posterior (LARP) canals or right anterior-left posterior (RALP) canals. All units were excited by rotation in a direction that excited a corresponding ipsilateral semicircular canal. Thus, they all displayed a "type I" response. With the animal upright, there were rapid changes in firing rates of both VO and VPS units in response to steps of angular velocity about a vertical axis. The units were bidirectionally activated during vestibular nystagmus (VN), horizontal optokinetic nystagmus (OKN), optokinetic after-nystagmus (OKAN) and off-vertical axis rotation (OVAR). The rising and falling time constants of the responses to rotation indicated that they were closely linked to velocity storage. There were differences between VPS and VO neurons in that activity of VO units followed the expected time course in response to a stimulus even during periods of drowsiness, when eye velocity was reduced. Firing rates of VPS units, on the other hand, were significantly reduced in the drowsy state. Lateral canal-related units had average firing rates that were linearly related to the bias or steady state level of horizontal eye velocity during OVAR over a range of +/- 60 deg/s. These units could be further divided into two classes according to whether they were modulated during OVAR. Non-modulated units (n = 5) were VO types and all modulated units (n = 5) were VPS types. There was no significant difference between the bias level sensitivities relative to eye velocity of the units with and without modulation (P > 0.05). The modulated units had no sustained change in firing rate in response to static head tilts and their phases relative to head position varied from unit to unit. The phase did not appear to be linked to the modulation of horizontal eye velocity during OVAR. The sensitivities of unit activity to eye velocity were similar during all stimulus modalities despite the different gains of eye velocity vs stimulus velocity during VN, OKN and OVAR. Therefore, VO and VPS units are likely to carry an eye velocity signal related to velocity storage.(ABSTRACT TRUNCATED AT 400 WORDS)


Effect of corticotectal tract lesions on relative motion selectivity in the monkey superior colliculus. Many cells in the superficial layers of the monkey superior colliculus are sensitive to the relative motion between a small target moving through the classic receptive field and a textured, moving background pattern that fills the visual field beyond the classic receptive field. The cells respond well when motion of the target differs from that of the background, but their responses are suppressed when the target moves in phase with the background. To determine whether this relative motion sensitivity depends on input to the colliculus from visual cortex, we studied colliculus cells in immobilized, anesthetized monkeys after unilateral thermocoagulation, or anesthetic blockade, of the corticotectal tract at the level of the pulvinar. In the colliculus ipsilateral to the corticotectal tract lesions, relative motion sensitivity was significantly reduced when compared either with the colliculus in intact animals or with the colliculus contralateral to the lesion. However, a moving-background stimulus still had a modest suppressive effect compared with a stationary background ("background motion sensitivity"), as is the case for intact animals. Anesthetic blockade of the corticotectal tract had similar effects; relative motion sensitivity, but not background motion sensitivity, was lost following injection of mepivacaine or bupivacaine. Pulvinar cell loss alone, induced by kainic acid injection, had no effect on relative motion sensitivity in the colliculus. The corticotectal tract lesions, but not the anesthetic injections, also had minor effects on flash-evoked responses and spontaneous discharge rates; these effects may reflect a retrograde response of some tectopulvinar cells to injury of their axons by the corticotectal tract lesions. In the colliculus opposite the corticotectal tract lesion, relative motion sensitivity was similar to that in normal animals. However, responses in the presence of a moving background were enhanced, suggesting that removal of cortical input to one colliculus may disinhibit the contralateral colliculus, a phenomenon reminiscent of the Sprague effect in the cat. We conclude that while cortical input to the colliculus may contribute little to the classic receptive field properties of superficial-layer cells, it clearly does contribute to relative motion sensitivity.