Visual sampling after lesions of the superior colliculus in rats. In two separate experiments, rats with bilateral lesions of the superior colliculus showed significantly poorer relearning of a horizontal/vertical stripe discrimination than control animals. In Experiment 1, all animals showed disruption of performance when a stimulus--response (S--R) separation was introduced by raising the stimuli above the site of responding. However, the colliculectomized rats were much more disturbed by the S--R separation than were animals in the control group. In Experiment 2, all animals showed lower performance levels when conflicting patterns were introduced into the upper portion of the stimulus doors, but this time the rats with collicular lesions were less disturbed than the control animals. It is suggested (a) that when the stimulus and response sites are discontiguous, animals must make an appropriate orienting response in order to effectively sample the visual stimuli and (b) that lesions of the superior colliculus alter performance by interfering with this orienting behavior. The impairment in relearning is tentatively attributed to the absence of preoperative overtraining on the discrimination task.


Regulation of energy balance in two models of reversible obesity in the rat. Adult male rats were made obese either by tube feeding varying fractions (34%, 47%, 68% or 75%) of their normal food intake or by offering them a varied and palatable diet (cafeteria diet). After 17--30 days of these regimens, the treatments were withdrawn, and the animals were allowed free access to the normal stock diet. Tube-fed animals precisely adjusted voluntary food intake to compensate for the energy delivered by tube but nevertheless became obese as a result of an increased metabolic efficiency. Cafeteria-fed rats were hyperphagic and became obese without any apparent change in metabolic efficiency. Recovery from obesity was more rapid in the cafeteria animals and was due to a pronounced increase in heat production as well as concomitant hypophagia. Animals previously made obese by tube feeding exhibited hypophagia and returned to normal weight without any change in heat production. The relevance of these results to the concept of lipostasis and the relative roles of energy intake and expenditure in the regulation of energy balance are discussed.


Electrophysiological responses to ethanol, pentobarbital, and nicotine in mice genetically selected for differential sensitivity to ethanol. Cortical electroencephalographic (EEG) changes induced by ethanol (4.3 and 1.4 g/kg, ip), pentobarbital (50 and 16 mg/kg), and nicotine (1.0 g/kg) were examined in long-sleep (LS) and short-sleep (SS) mice that were genetically selected for differential sleep times induced by a hypnotic dosage of ethanol. Ethanol (4.3 g/kg) caused EEG changes that paralleled the behavioral differences, whereas no differences between selected lines were observed following the activating dose (1.4 g/kg). Data support the notion that the known difference in ethanol sleep times is due not to greater SS sensitivity to ethanol activation but rather to greater LS sensitivity to ethanol hypnosis. No differences between selected lines were observed following 50 mg/kg pentobarbital, which again parallels previous behavioral data. The SS mice were more responsive to pentobarbital activation (16 mg/kg). Nicotine more severely reduced EEG power and heart rate in LS mice; a continuous iv infusion of nicotine elicited a distinct pattern of behavioral stereotypy for each selected line, with more profound motor and reflex depression in LS mice. The lines do not differ in rate of nicotine metabolism, hence they must differ in central nervous system sensitivity to nicotine. Thus, lines of mice selectively bred for differential sensitivity to ethanol also display marked differences in electrophysiological and behavioral responses to nicotine.


Differential effects on body weight of central 6-hydroxydopamine lesions in obese (ob/ob) and diabetes (db/db) mice. Obese (ob/ob) and diabetes (db/db) mice are genetic mutants that have been shown to have altered levels of central catecholamines as well as syndromes of obesity, hyperphagia, and hyperglycemia. Because of catecholamines, and particularly norepinephrine (NE), are implicated in the control of feeding, levels of central catecholamines were experimentally reduced in ob/ob and db/db mice to investigate the role of the catecholamines in these cases of spontaneously occurring obesity. Lesions produced by 6-hydroxydopamine (6-OHDA) were used to produce large depletions of NE and dopamine (DA) in both ob/ob and db/db mice and in lean control mice of the same background strains. In the db/db but not the ob/ob, central catecholamine depletion was accompanied by a significant and persistent weight loss and by a reduction in plasma glucose levels when compared with vehicle-infused controls. Treatment with the NE uptake blocker desmethylimipramine (DMI) prior to 6-OHDA infusions attenuated NE but not DA depletion. Diabetes mice that received DMI pretreatment showed a weight loss and decrease in plasma glucose proportional to the amount of NE depletion. Lean mice that received the 6-OHDA treatments showed only a transient weight loss and no significant change in blood glucose. It is concluded that abnormalities in central noradrenergic systems may account for part of the obesity syndrome observed in the diabetes mouse.


Ontogenetic changes in the modulation of taste aversion learning by home environmental cues in rats. Eight experiments using 611 rats as subjects were conducted to define and analyze an age-related phenomenon of conditioned taste aversion. When consumption of sucrose solution was followed by LiCl-induced illness in the animals' home, acquisition of the aversion to sucrose solution was retarded in preweanling (18-day-old) rats. This effect was not found in adults or in slightly older (21-day-old) rats. Place of testing had no effect in the younger two age-groups, but in adults manifestation of the acquired aversion was retarded when they were tested in the home. There was no interaction between place of conditioning and testing for any age. The locus of the environmental influence on conditioning in preweanling rats was found to be the place of tasting rather than place of illness, retention interval, or testing. Also, the effect was found to be invariant under minor variations in familiarization of the animal with the non-home environment. The principle emerging from these data and others is that the home environment can have a significant influence on learning and conditioning in the immature rat.


Brain transections selectively alter ingestion and behavioral activation in neonatal rats. Food-deprived neonatal rats actively ingest milk that is infused into their mouths through intraoral cannulas. This ingestion is accompanied by behavioral activation. The involvement of various brain regions in ingestion and activation was examined by making transections along the neuraxis from the olfactory bulbs to the anterior pons in 2-day-old rats. Following a 24-hr deprivation period, a series of oral milk infusions was given, and milk intake and activity were measured. Intake was severely reduced only in animals with diencephalic transections. Cuts in front of or behind the diencephalon resulted in normal or slightly decreased intake. In contrast, activity tended to decline as the level of the transection became more caudal. Thus ingestion and its accompanying behavioral activation could be separated neuroanatomically. These results suggest that two brain mechanisms are involved in the ingestive response of the infant rat, one in the diencephalon and another caudal to the mesencephalon. However, behavioral activation appears less discretely organized, involving most of the neuraxis.


Differentiating ganglionic function in the earthworm. Traditional formulations of the roles of supra- and subpharyngeal ganglia in the earthworm's behavior were reinvestigated with the use of saline rather than light as the aversive stimulus. Eight different operated groups were tested in a modified T-maze eliciting four classes of unconditioned responses. The factorial design used specifically contrasted a "mass condition" (degree of neural damage) with a "locus condition" (proximity of the ablation to either the supra- or subpharyngeal ganglion); changes over postoperative days were also investigated. The number of changes in head orientations during arm choice were found to be greatest after dorsal anterior ablation and fewest after ventral posterior ablation (both a mass and a locus effect). Contrary to the traditional view, interference with subpharyngeal processing did not reduce backing capacity; rather, backing propensity after aversive stimulation was increased relative to other ablations (a locus effect). In addition, a large, time-dependent increase in nonstarts was found primarily associated with ventral transection of the circumpharyngeal connectives; a 2-day delay in the appearance of this effect suggests that it is of neurohumoral origin.


Performance of rats on the Maier three-table task following septal lesions occurring 24 hours after birth. The purpose of this study was to determine whether behavioral sparing would be demonstrated when septal lesions occurred prior to the age at which the tested behavior first appears in normal rats. Rats given septal lesions at 1 day or 7 days after birth performed at approximately chance on the Maier three-table task when tested at 90 days of age. Rats that had control electrode insertions at the same ages performed at a level similar to normal animals. Animals given septal lesions at either age explored significantly more than did control animals. Results are discussed in terms of the constancy over time of the septal contribution to performance on the three-table task and the involvement of the septum and hippocampus in the processing of spatial information.


Habituation and the human evoked potential. Habituation of human scalp-recorded cerebral evoked potentials was studied in response to auditory and visual repetitive stimuli of different intensities. Changes in magnitudes of evoked potentials with stimulus repetition were examined according to the parametric characteristics of habituation, generalization, and dishabituation. In addition, tests of the predictions of two theories of habituation were made regarding the degree and direction of intensity generalization of habituation. Both auditory and visual evoked potentials exhibited decrements in response magnitudes across the repetitive stimuli consistent with the parametric criteria of habituation. Early evoked potential peak components showed a pattern of intensity generalization of habituation consistent with the predictions of the dual-process theory of habituation. Intensity generalization of late evoked potential peak components occurred in a manner more consistent with the predictions of the stimulus comparator theory of habituation. These results provide further evidence that evoked potentials can be used as electrophysiological indexes of plasticity in humans.


Social chemosignals in five Belontiidae (Pisces) species. Approach behaviors toward conspecific chemical stimuli of the opposite sex were examined in five Belontiidae species: Betta splendens, Macropodus opercularis, Colisa labiosa, C. lalia, and Trichogaster trichopterus. Approach was measured by (a) preference for section 1 of a three-section tank, which contained a vertical tube that introduced the stimulus water, and (b) occupancy of the tube. Experiments 1A and 1B showed that (a) approach behaviors were displayed by the isolated male Betta only to ripe-female stimulus water, (b) group-housed males of the remaining four species were not attracted to female-conditioned water, and (c) socially isolated males of these four species preferred section 1 during presentation of either ripe- or nonripe-female-inhabited water but occupied the tube only during exposure to ripe-female-conditioned water. The findings of Experiment 2A were that (a) the female Betta, regarless of physiological state, showed approach behaviors to male-inhabited water and (b) only ripe females of the remaining species indicated a preference for section 1 during male-water exposure but performed no tube entries. Results of Experiment 2B indicated that social isolation of the females, especially ripe females, facilitated their approach behaviors.


Transection of direct anterior thalamic afferents from the hippocampus: effects on activity and active avoidance in rats. This investigation demonstrates the importance of the direct hippocampo-anterior thalamic component of the postcommissural fornix in the control of general locomotion and active avoidance. Transection of anterior thalamic afferents from the hippocampal formation (subicular cortex), at the point where they exit from the fornix posterior to the septum, is sufficient to enhance bidirectional active avoidance acquisition and increase general activity. This transection may also interrupt fibers to or from other thalamic nuclei and the anterior septum. However, destruction of connections of the anterior septum with the hippocampus, habenula, and thalamus by transection in the coronal plane anterior to the descending fornix columns, without damage to the subiculothalamic fibers, increases general activity levels without damage to the subiculothalamic fibers, increases general activity levels without affecting active avoidance behavior. The activity increase in this case resembles that seen after septal lesions rather than that seen after hippocampal lesions. Thus, destruction of a single fornix component contributing afferents to the anterior thalamic nuclei reproduces at least part of the hippocampal syndrome. This suggests that these fibers contribute significantly to the control of these behaviors and may mediate active avoidance changes resulting from hippocampal and fornix damage.


Ultrastructure of the fibrous substance in the keratinocytes of the epidermis in healthy individuals. The present findings in the epidermis of healthy individuals suggest that the fibrous substance in the keratinocytes is subjected to an individual differentiation as the cells move from stratum basale through strata spinosum and intermedium to stratum coreum. In the basal cells the fibrous substance consists of opaque tonofilaments, mostly aggregated in dense tonofibrils, but also occurring randomly scattered and in loose tonofibrils (fibrous substance of basal-cell type). In most cells the fibrous substance undergoes differentiation: a) in stratum spinosum into compact tonofibrils with no individual tonofilaments visible (fibrous substance of spinous-cell type), b) in stratum inter-medium into compact tonofibrils with intensely stained regions or keratohyalin (fibrous substance of intermediate-cell type), and c) in stratum corneum into tonofibrils with a keratin pattern (fibrous substance of horny-cell type). There are also keratinocytes in which the fibrous substance undergoes only an incomplete differentiation, with the appearance of horny cells with a fibrous substance of spinous-cell type, intermediate-cell type or horny-cell type with keratohyalin. Finally, there are keratinocytes in which the fibrous substance does not undergo any differentiation at all, but which display a fibrous substance of basal-cell type throughout the entire epidermis.


Ultrastructural and cell surface changes of human psoriatic skin following Goeckerman therapy. Ultrastructural and cell surface studies of skin in psoriatic patients prior to and after Goeckerman therapy (crude coal tar and UVB-light) have demonstrated significant cellular changes following this treatment: hyperactivity of melanocytes with melanosome polymorphism, increase of desmosomes, tonofilaments, keratohyaline granules, a decrease in mitochondria, keratinosomes, polysomes, dark cells and a reduction in size of nuclei and nucleoli. The enlargement of intercellular spaces and the redundancy of basement membrane were also reduced. Langerhans cells were moderately decreased and exhibited a normal ultrastructural pattern. No significant changes in cutaneous nerve distribution or morphology were observed in these cases. Scanning electron microscopy following treatment revealed a regular surface and orientation of corneocytes, with flattened surfaces; and a reduction of their ridges on the surfaces, as well as of the intercellular spaces and red blood cells. These findings indicate that Goeckerman therapy restored the ultrastructural and cell surface pattern in the psoriatic skin by inducing orthokeratinogenesis, development of the tonofibrillar-desmosome system, and decrease in mitochondria, nuclei and nucleoli.


Prurigo nodularis: a reappraisal of the clinical and histologic features. Study of 14 patients with prurigo nodularis revealed that clinically the lesions were multiple, verrucous, and discrete and were set in normal-appearing skin. Microscopically, the lesions showed a vascular acanthomatous mass. The dermal nerves showed a tendency toward hyperplasia in parallel with the epidermal and vascular changes, but no evidence of neuroma formation was seen. Electron microscopic examination showed disorganization of the normal pattern of the myelin sheaths and axons of the dermal papillary nerves. The presence of epidermal mast cells was noted in the biopsy specimens of prurigo nodules from eight of the 14 patients.


Ultraviolet light in familial benign chronic pemphigus. Ultraviolet light (UV) tests with high irradiation doses from a dysprosium lamp were performed on the normal appearing skin of seven patients with benign familial chronic pemphigus (FBCP). The skin of the patients showed a more severe vulnerability when compared with the reactivity of the skin of four healthy control persons. In each case the damaged skin of the patients had, in addition to the destructive features, the diagnostic histological acantholysis of FBCP. There was great variation in individual responses to the provocative irradiation and thus the test cannot be considered practical for accurate diagnostic purposes.


Disrupted desmosomes in induced lesions of familial benign chronic pemphigus. An occlusive dressing was applied to the unaffected skin of the back of a patient with familial benign chronic pemphigus (FBCP). Small lesions of FBCP appeared after 48 h, and the ultrastructure of successive biopsies was studied. It was concluded that: (a) the initial phenomenon in FBCP is the result of an insufficiency of cellular adhesion. This confirms several previous reports. (b) desmosomes are separated in two halves, invaginated in vacuoles and later deeply included in the cell. The particular fate of these disrupted desmosomes has already been observed after the action of several enzymes on the epidermis and in Darier's disease.


Basal cell epitheliomas in usual and unusual sites. 2,126 consecutively diagnosed basal cell epitheliomas (BCE) were studied for unusual sites of occurrence. A small number of BCE occurred in unexpected locations and presented some difficulty in clinical diagnosis.


Spontaneous regression in basal cell carcinomas. Evidence of previous spontaneous regression was found in 6% of 400 randomly selected basal cell carcinomas. A further 14% showed small foci of active regression usually less than 1 high power field in area and characterized by a lymphocytic infiltrate of tumor nests associated with many apoptotic tumor cells. Spontaneous regression of basal cell carcinomas has been paid scant attention in the past.


Pilar sheath acanthoma. A new benign follicular tumor. Pilar sheath acanthoma is a recently recognized entity. The tumor is a benign follicular neoplasm, occurring on the skin of the upper lip. This paper reports the 10th recorded case.


Trichilemmal tumor undergoing specific keratinization: "keratinizing trichilemmoma". Numerous tumors with follicle-like direction of differentiation have been described. At least three of them connected to the overlying epidermis are related to the outer root sheath or trichilemma: the tumor of follicular infundibulum (Mehregan & Butler 1961) and the inverted follicular keratosis (Helwig 1955) or follicular poroma (Duperrat & Mascaro 1963) have been related to the infundibulum, the tricholemmoma (Headington & French 1961) to the lower outer root sheath. On the occasion of a case first diagnosed as proliferating trichilemmal cyst of the scalp, we think we have individualized a tumor exhibiting ability to undergo trichilemmal keratinization. We describe its histogenesis and stress its peculiarties compared with other lesions showing trichilemmal keratinization.


Acid nonspecific esterase in human Langerhans cells. Epidermal dendritic cells showing a diffuse activity of acid nonspecific esterase were observed in three cases of mycosis fungoides stage I. As these cells by their appearance and localization resemble Langerhans cells, and dermal histiocytes and macrophages react in the same manner, this is another enzyme cytochemical suggestion of a relationship between Langerhans cells and the monocyte-macrophage-system.


Cell proliferation in a malignant angioendothelioma during sequential chemotherapy. The rate of cellular proliferation was studied in the neoplastic cells of a malignant angioendothelioma and in its inflammatory infiltrate by means of optical radioautography after incorporation ex vivo of tritiated thymidine. One third of the normal looking, as well as the atypical, endothelial cells were engaged in the cell cycle of proliferation. This large pool has been effectively suppressed during subsequent chemotherapy which resulted in partial regression of the neoplasm. The proliferative activity of the infiltrate was higher inside the neoplasm than at its periphery.


Dermatomyositis with universal calcinosis. A histopathological and electron optic study. Biopsies from a 5-year-old girl with dermatomyositis and universal calcinosis were studied histopathologically and by means of electron optical techniques. The dermis was infiltrated by fibroblasts, lymphocytes and plasma cells. In the lower part of the dermis, dense basophilic areas were present. In the vicinity of these areas irregular elastic fibers appeared. In the electron microscope these elastic fibers appeared mineralized to varying degrees. The mineral part was identified as calcium apatite (either calcium-hydroxy-apatite or calcium fluoroapatite) by X-ray microanalysis and selected area diffraction. No calcification was observed outside the elastic fibers.


Subcutaneous fat necrosis in pancreatitis. A case of subcutaneous fat necrosis as the initial manifestation of an attack of acute pancreatitis is presented. The accompanying features of respiratory distress syndrome, leukemoid reaction, shock, pleural effusions, and arthritis due to necrosis of periarticular fat are described. Autopsy findings are pancreatic pseudocyst, serofibrinous peritonitis, pleuritis, and pericarditis and fat necrosis not only in the subcutaneous fat but also in the pericardial, pleural, mediastinal, mesenteric, retroperitoneal, and pericalyceal fat.


Divided nevus spilus and divided form of spotted grouped pigmented nevus. Two cases of divided nevus spilus and a case of divided form of spotted grouped pigmented nevus are reported. In this group, flat melanotic macules around the eyes were located on the opposite parts of the upper and lower eyelids. The macules were divided by the palpebral fissure when the lids were open, and the two halves of the lesions formed a unit when the lids were closed. Case presentation as such may be intriguing in the clarification of the developmental relation between aberrantly differentiated melanin synthesizing cells and normal melanocytes.


Furuncle.

Furuncle. Microscopic pictures of furuncles are rare in dermatologic literature. This report illustrates features of a furuncle that was completely excised. There was destruction of the epidermis, remnants of the involved hair follicle within an area of tissue necrosis, a large abscess with many polymorphonuclear leukocytes and small clusters of Staphylococci. The contrast with an uninvolved hair follicle observed in the vicinity of the furuncle was striking.


Muscarinic receptor regulation of NG108-15 adenylate cyclase: requirement for Na+ and GTP. Cholinergic agonists inhibit the basal and PGE1-activated adenylate cyclase activity in membranes isolated from the mouse neuroblastoma x glioma hybrid cell NG108-15. Inhibition is observed with acetylcholine, acetyl-beta-methylcholine and carbachol and is blocked by two specific muscarinic antagonists, atropine and quinuclydinylbenzilate. Inhibition of basal and PGE1-activated activity is only partial. Carbachol-directed inhibition has an apparent Km of 6 microM in the presence or absence of PGE1. Both the guanine nucleotide GTP and the monovalent cation Na+ are required for this muscarinic inhibition of basal and PGE1-activated NG108-15 adenylate cyclase. The selectivity observed for monovalent cations (all chloride salts) in this process is Na+ congruent to Li+ greater than K+ greater than Choline+ with the ED50 for Na+ congruent 40 microM. Of the nucleotides tested, only IT (and not ATP, UTP or CTP) replaces GTP in this process. GTP at 10 microM represents a saturating nucleotide concentration. Opiate-directed inhibition of NG108-15 adenylate cyclase has recently been shown to exhibit a similar requirement for GTP and Na+ [Blume, A. J., Lichtshtein, D. and Boone, G. (1979) Proc. National Academy of Sciences, USA, in press]. The data presented here therefore support the hypothesis that the general transfer of inhibitory information from membrane receptors to adenylate cyclase involves both a Na+ and GTP-sensitive process.


Speech perception in early infancy: perceptual constancy for spectrally dissimilar vowel categories. While numerous studies on infant perception demonstrate the infant's ability to discriminate individual speech-sound pairs, very few demonstrate the infant's ability to recognize the similarity among phonetic units when they occur in different phonetic contexts, in different positions in a syllable, or when they are spoken by different talkers. In two studies, six-month-old infants demonstrated the ability to distinguish two spectrally dissimilar vowel categories (/a/ and /i/) in which the vowel tokens were generated to simulate tokens produced by a male, a female, and a child talker. In experiment I, the infants were initially trained to discriminate the /a/ and /i/ tokens produced by the computer-simulated male voice. They were then gradually exposed to a number of novel tokens in a progressive transfer-of-learning task. In experiment II, the infants were initially trained to discriminate the same vowell contrast, but were then immediately tested with all of the tokens in both vowel categories. In both experiments the infants demonstrated rapid transfer of learning from the training tokens produced by the male talker to the tokens produced by female and child talkers. Both experiments provide strong evidence that the six-month-old infant recognizes acoustic categories that conform to the vowel categories perceived by adult speakers of English.


Some effects of deafness on the generation of voice. Glottal volume-velocity waveform data were collected from twenty male and female hearing-impaired adolescents by means of a reflectionless tube. The subjects each provided samples of phonation in normal- and soft-voice modes and in a three-syllable word with primary stress on the medial syllable. Analysis of the data, in comparison with characteristics of phonation produced by normally hearing subjects, indicates that deafness affects primarily the time-varying characteristics of the glottal source. Among the hearing-impaired subjects, the following abnormalities were noted; diplophonia and creaky-voice episodes at the onset or middle of phonation, and irregular patterns of change in the frequency and intensity of the glottal waveform. For some subjects, the period-to-period changes of frequency and intensity may be greater than normal. For the hearing-impaired subjects, the shape of the isolated glottal pulse and its spectrum are similar or identical to normal, while striking abnormalities may be seen in the way the glottal pulse changes over time. The effect of deafness is thus that it may prevent a speaker from learning the phonatory consequences of the muscular gestures which maintain and alter vocal-fold tension and subglottal air pressure dynamically in the production of voice.


Formant frequency patterns in Russian VCV utterances. Previous studies have sought to establish the significance of various parameters in the determination of the patternings of Russian formant frequency trajectories in vowel-consonant-vowell (VCV) syllables. In the present study, 9600 measurements of first and second formant frequency were made on Russian VCV nonsense words. Variance for speakers was controlled through regression. Stepwise multiple regression was employed to determine the relative contributions of six predictors to the explanation of the patternings of first and second formant frequency in the test words. The six predictors included the height of the first and second vowels, the fron/back dimensionality of the first and second vowels, the place of articulation of the consonant, and the palatalization or nonpalatalization of the consonant. Results of the regression analyses are summarized. The regression coefficients for the useful predictors of the various dependent variables comprise a model of formant frequency patterns in Russian VCV utterances.


Analysis of stop consonant production errors in developmentally dysphasic children. The speech production skills of 12 dysphasic children and of 12 normal children were compared. The dysphasic children were found to have significantly greater difficulty than the normal children in producing stop consonants. In addition, it was found that seven of the dysphasic children, who had difficulty in perceiving initial stop consonants, had greater difficulty in producing stop consonants than the remaining five dysphasic children who showed no such perceptual difficulty. A detailed phonetic analysis indicated that the dysphasic children seldom omitted stops or substituted nonstop for stop consonants. Instead, their errors were predominantly of voicing or place of articulation. Acoustic analyses suggested that the voicing errors were related to lack of precise control over the timing of speech events, specifically, voice onset time for initial stops and vowel duration preceding final stops. The number of voicing errors on final stops, however, was greater than expected on the basis of lack of differentiation of vowel duration alone. They appeared also to be related to a tendency in the dysphasic children to produce final stops with exaggerated aspiration. The possible relationship of poor timing control in speech production in these children and auditory temporal processing deficits in speech perception is discussed.


A system for evaluating auditory function from 8000--20 000 Hz. A system for the measurement of auditory function from 8000--20 000 Hz is described. This system introduces advances in: (a) maximum power output, (b) signal fidelity, and (c) transducer characteristics. Two case studies are presented to illustrate the clinical information gained from the measurement of high-frequency auditory sensitivity, which is not readily apparent in conventional threshold assessment.


Forward masking with equal-energy maskers. Temporal masking of chicks by noise was investigated using a forward-masking paradigm. The temporal separation delta T between the click and the noise ranged from 0.03 to 100 msec. The duration of the noise varied from 3 to 500 msec while its energy remained fixed. For fixed delta T (delta T greater than 3 msec), the masking effect may actually increase for the longer, less intense noises despite the fact that, for long maskers, there is less masker energy near the signal in time. These results are interpreted in terms of the modified version of the running-average hypothesis [M. J. Penner, J. Acoust. Soc. Am. 63, 195--201 (1978)] in which it is argued that the auditory system compresses the intensity of the stimulus prior to integrating it. If the temporal integrator depends on stimulus intensity, then these results may be easily predicted. As an alternative explanation we show that compression may reduce the effective intensity of short maskers to such an extent that they do less masking than the longer ones. Such reduction in masking effectiveness will occur if the time between the masker and the signal is long enough so that the effects of compression and integrator shape do not counterbalance each other.


Psychophysical frequency resolution in the cat as determined by simultaneous masking and its relation to auditory-nerve resolution. Critical bandwidths were measured behaviorally at 1 and 2 kHz by simultaneous masking in four cats. Three methods were used. They were (i) the masking of a tone by noise of variable bandwidth, (ii) the masking of a narrow-band signal by two tones, and (iii) the masking of a tone by noise of rippled spectrum. The three methods agreed closely and gave a mean critical bandwidth of 410 Hz at 1 kHz and 690 Hz at 2 kHz. These values were about three times as great as the electrophysiologically-determined effective bandwidths of single fibers of the auditory nerve at the same frequencies, both as measured in other animals, and in one of the animals that had been tested behaviorally as well. Psychophysical tuning curves were also determined behaviorally; in contrast, they agreed closely with auditory-nerve fibers in both bandwidth and slope. The results suggest that the critical band as measured by simultaneous masking is not a close relation of the frequency-threshold curve of auditory-nerve fibers, but that the psychophysical tuning curve possibly may be. Possible reasons and implications are discussed.


Discrimination of symmetric time-intensity traded binaural stimuli. Experiments were conducted to determine the extent to which listeners can discriminate between different combinations of interaural time and intensity for binaural stimulus configurations which eliminate loudness, lateralization, and image-diffuseness cues. A two-interval forced choice paradigm was used, and the task of the subject was to determine the order of two stimuli, each of which was a slowly gated 500-Hz tone with a combination of interaural time and intensity differences that resulted in a centered primary spatial image. The two stimuli to be discriminated were symmetric in that they differed only in the polarity of their interaural differences. Also, in order to reduce artifacts introduced by variations in the coupling of the earphones to the head, acoustic monitoring and compensation was performed both before and after each experimental run. The performance of the two most highly trained subjects is consistent with previous experimental results that indicate an incomplete trading of interaural time and intensity information. The subjective perceptions of these observers are not consistent with previous studies that describe a "time image" and a "time-intensity traded" spatial image.


A neural-counting model incorporating refractoriness and spread of excitation. I. Application to intensity discrimination. We consider in detail a new mathematical neural-counting model that is remarkably successful in predicting the correct detection law for pure-tone intensity discrimination, while leaving Weber's law intact for other commonly encountered stimuli. It incorporates, in rather simple form, two well-known effects that become more marked in the peripheral auditory system as stimulus intensity is increased: (1) the spread of excitation along the basilar membrane arising from the tuned-filter characteristics of individual primary afferent fibers and (2) the saturation of neural counts due to refractoriness. For sufficiently high values of intensity, the slope of the intensity-discrimination curve is calculated from a simplified (crude saturation) model to be 1-1/4N, where N is the number of poles associated with the tuned-filter characteristic of the individual neural channels. Since 1 less than or equal to N less than infinity, the slope of this curve is bounded by 3/4 and 1 and provides a theoretical basis for the "near miss" to Weber's law.


Measurements of binaural echo suppression. The notion of binaural echo suppression that has persisted through the years states that when listening binaurally, the effects of reverberation (spectral modulation or coloration) are less noticeable than when listening with one ear only. This idea was tested in the present study by measuring thresholds for detection of an echo of a diotic noise masker with the echo presented with either a zero or a 500-musec interaural delay. With echo delays less than 5-10 msec, thresholds for the diotic echo were about 10 dB lower than for the dichotic signal, a finding opposite that of the usual binaural masking-level difference but consistent with the notion of binaural echo suppression. Additional echo-threshold measurements were made with echoes of interaurally reversed polarity, producing out-of-phase spectral modulations. The 10-15 dB increase in thresholds for the reverse-polarity echo, over those for the same-polarity echo, indicated that the apparent "hollowness" associated with spectral modulations can be partially canceled centrally. Overall, the results of this study are consistent with a model in which: (1) the monaural representations of spectral magnitude are nonlinearly compressed prior to being combined centrally; and (2) neither monaural channel can be isolated in order to perform the detection task.


Spectral properties of fricative consonants in children. Twenty-one preadolescent children were asked to produce stimulus words with the fricatives /f/, /v/, /s/, /z/, /s/, and /3/ in various phonetic environments. Results indicated that the major resonances were higher than values reported for both male and female adult speakers. Also significant differences existed among the major resonances of the consonants studied.


Cognitive abilities and disabilities in infantile autism: a review. The literature on various aspects of learning and performance in autistic children is reviewed and interpreted as indicating very little that is specific to autism. Inadequate and inconsistent methodology precludes generalizations concerning the nature of the disorder. It is suggested that future research should be particularly concerned with controlling for developmental influences on performance, and with investigation of the higher functioning autistic children who are less governed by retardation factors. The current evidence is considered to support a hypothesis concerning abnormal hemisphere functioning in this group of children.


The evaluation of an intervention program for young schoolchildren with acting-out problems. The rationale and nature of a program to train nonprofessional child-aides for helping interactions with young acting-out school children are described. Pre/post teacher measures of children's problems and competencies, aide measures of problem behavior, and school mental health professionals' change in behavior estimates were used to evaluate the program's effectiveness. Children seen by trained aides showed significantly greater reductions both in acting-out problems and in overall maladjustment than did similar children seen by comparable aides who did not have additional training, or by themselves before training. Implications were considered for optimizing outcomes both in the specific school intervention project in question and in other, broader types of clinical interventions.


Early intervention for female sexual identity disturbance: self-monitoring of play behavior. This study is the first experimental demonstration of sex-typed play behavior change in a young girl with sexual identity disturbance. The 8-year-old child was treated with a self-monitoring procedure combined with a behavioral prompting technique that was gradually faded out. Self-monitoring in the clinic resulted in a high, stable rate of appropriate sex-typed play, and this effect generalized to a different set of sex-typed toys over time. The treatment effects did not generalize to the home environment. The self-regulation intervention was subsequently adapted to the home setting, resulting in a replication of the treatment effects across settings. After the removal of the self-monitoring interventions, a high level of feminine sex-typed play persisted. Pretreatment, posttreatment, and follow-up psychological testing demonstrated a reversal of a pronounced cross-gender identity to a normal female sexual identity.


Hyperactive boys in their classroom: assessment of teacher and peer perceptions, interactions, and classroom behaviors. Teacher ratings, peer perceptions, peer interactions, and classroom behaviors of 17 hyperactive and 17 active elementary school-age boys, nominated by their teachers, were compared using multivariate analyses and planned comparisons in order to better describe and assess hyperactivity in its most probable setting--the classroom. Hyperactive boys were found to be significantly different from actives on measures from all data sources in that they were perceived and interacted more negatively. Cluster analyses of teacher ratings of 90 hyperactives from a clinical sample and 17 hyperactives from the current sample were used to discriminate among different types of hyperactives. Four types were named anxious, conduct problems, inattentive, and low problem hyperactives. The fact that six conduct problem hyperactives were found to be more disruptive and have higher activity level ratings than six inattentive hyperactives, when observed in their classrooms, points to the need to study and treat hyperactives as heterogeneous groups.


Discrimination learning of delinquent boys as a function of reinforcement contingency and delinquent subtype. Previous research has demonstrated the effectiveness of contingency management as a means of behavioral resocialization with delinquent boys on an individual basis. The present study was designed to examine and clarify systematically verbal and token reward and/or punishment. The principal findings of the study were: (1) Neurotic subjects performed at the highest level for punishment, at the lowest level for reward, and at an intermediate level for a combination of reward and punishment, regardless of verbal or token contingency modality. (2) Psychopathic subjects performed best for the joint verbal reward and punishment contingency, but they did not learn over trials for the joint token reward and punishment contingency. Their performance was undifferentiated at asymptote under the separate verbal and token reward or punishment contingencies. (3) Neurotic subjects performed at a significantly higher level than did psychopathic subjects for verbal and token punishment, while psychopathic subjects performed at a significantly higher level than neurotic subjects for verbal and token reward.


Analyses of changes in verbal behavior following a cognitive-behavioral treatment for impulsivity. Analyses were conducted to examine further the results of a cognitive-behavioral treatment for impulsivity in emotionally disturbed children (Kendall & Finch, 1978). The verbal behaviors of treated impulsive children, impulsive controls, and reflective children, recorded during MFF performance at pretreatment, posttreatment, and follow-up, were examined. The results indicated nonsignificant effects for several specific codes; however, the impulsive children that had received treatment evidenced a significant increase in total on-task verbal behavior at posttreatment. Discussion includes a consideration of these findings in regard to the efficacy of the cognitive-behavioral treatment and the need for research on the assessment of cognitive variables in children.


Congenital correlates of distractibility. The present research reports correlations between ratings of distractibility and minor physical anomalies and gross motor incoordination. For an original and two replication samples of preschool children, there were significant average weighted correlations between distractibility and both minor physical anomalies and gross motor incoordination for boys. Also, the magnitude of the correlation between distractibility and the congenital characteristics was significantly higher for boys. Although neither parental rejection nor parental restrictiveness was related to boys' distractibility, parental rejection was marginally related to girls' distractibility.


Effects of methylphenidate (Ritalin) on selective attention in hyperactive children. This study investigated the effect of methylphenidate (Ritalin) on the selective attention of hyperactive children designated as favorable or adverse responders to stimulant medication. Using a type II incidental learning paradigm, it was found that children in the drug condition recalled more central and less incidental stimuli than those children in the placebo condition. While no differential effects on recall were found for responder type, methylphenidate did affect the spontaneous overt labeling of central stimuli by the favorable responder group. Results were interpreted in terms of the role of methylphenidate in narrowing the focus of attention. Implications for the classification of hyperactive children as favorable and adverse responders were also discussed.


Social perspective-taking and teacher ratings of peer interaction in hyperactive boys. Hyperactive and matched control boys at two age levels were compared on teacher ratings of peer interaction and three measures of social perspective-taking. The teachers' ratings of peer interaction discriminated between the hyperactive children and their controls. In addition, a significant interaction effect indicated that teachers rated the older hyperactive group as more deviant with peers than both their younger hyperactive counterparts and their age-matched controls. In a structured laboratory setting, the hyperactive children did not differ from control children on the three measures of social perspective-taking. The perspective-taking measures did, however, show differences across age groups. Implications for treatment are examined.


Behavior problems of educationally handicapped and normal pupils. Male pupils identified as behaviorally disordered, learning disabled, and educable mentally retarded, as well as nonidentified normal boys, were rated by their teachers on the Behavior Problem Checklist. Analyses of the ratings indicated significant differences for pupil category, Behavior Problem Checklist dimension, and category by dimension interaction, but no significant differences for age alone or in interaction with other factors. Categories of pupils were best discriminated from one another on the basis of Conduct Disorder and Personality Problem dimensions of the Behavior Problem Checklist. Results were discussed in terms of some implications for special education and further research suggested by the present findings.


Primary eye care for the pediatric patient. The primary care needs of the pediatric patient include the measurement of norms and deviations in the newborn (neonate) and subsequently, developmental milestones. Considerations of such norms and deviations must include familial and hereditary implications, systemic conditions and general health status. Deviations from the expected norms in the newborn and during development must be evaluated by the parent (as the true primary pediatric provider) and responsible health and eye care professionals. Such evaluation should include a sensitivity and awareness of the ocular and visual status, identification of norms and deviations and appropriate courses of action.


Ocular manifestations of systemic childhood diseases: some systemic diseases are no respecters of age. Many diseases commonly thought to affect the older population may be present in children. Examples are given of conditions which might be unsuspected in children and which might, therefore, be undiagnosed until severe, irreversible damage is done.


Heredity in congenital esotropia.

Heredity in congenital esotropia. As an approach to the problem of familial tendency for congenital esotropia, four families were selected because of proband (index case) who had congenital esotropia. Available family members were evaluated for strabismus and other anomalies of vision. Several possible risk factors were evaluated and the presence of high accommodative convergence-to-accommodation ratio was remarkable. Increased prevalence of congenital esotropia was found among family members as compared to the general population, but with no consistent pattern of Mendelian (single gene) inheritance. These findings are consistent with but not proof of a multifactorial (polygenic and environmental interaction) model. The implication for practicing optometrists is that families with one member affected with congenital esotropia represent a group with increased risk for recurrence.


Cosmetic contact lenses in the care of the child. As their name implies, cosmetic contact lenses are used to hide or cover blemishes or disfigurements of the iris, cornea, or sclera. A wide variety of options are available to the optometrist in attempting to aid a child with an ocular disfigurement. The customized artist-painted scleral shell is ideal in many cases, but a surprising number of defects can be adequately camouflaged with corneal lenses presently available from laboratories. The future use of cosmetic soft lenses is promising, and since many conditions involving the need for optical correction are capable of provoking future visual disorders, infants today can look forward to better vision when a cosmetic contact lens is fitted early in life.


Fixational eye movements in amblyopia and strabismus. Horizontal eye position was monitored using a photoelectric method during monocular and binocular fixation in four patients having amblyopia without strabismus, thirteen patients having constant strabismus with amblyopia, and five patients having intermittent strabismus. Four abnormalities of fixation were found: increased drift, saccadic intrusions, manifest nystagmus, and latent nystagmus. Increased drift was related to the presence of amblyopia, while saccadic intrusions and nystagmus were related to the presence of strabismus. Understanding dynamic aspects of oculomotor control can provide insight into clinical assessment of fixation in amblyopia and strabismus.


Managing the low vision patient.

Managing the low vision patient. The low vision child has long been neglected by the professional community. A self-analysis of the usefulness of optometric service must be made as to professional attitudes and the understanding of the low vision aids as well as the patient that is expected to wear them. Once these hurdles are overcome, the optometrist is more able to help the low vision child become a productive, contributing member of society.


Contact lenses in the case of the very young child. Many hereditary congenital and infectious ocular conditions affecting young infants and children if diagnosed early enough are no longer untreatable. Special contact lenses are now available and have been specifically developed to prevent blindness, amblyopia and establish binocular vision. Different types of contact lenses and materials from which they may be fashioned are discussed and clinical considerations outlined for treatment. Visual rehabilitation of a high order is possible with proper understanding of the particular problems affecting babies at birth, later and in early infancy.


Implications of central retinal artery occlusion. The purpose of this paper, was to discuss central retinal artery occlusion and its role in the patient's overall health. Several different causes of occlusion such as cardiovascular diseases, carotid artery disease, aortic arch disease and giant cell arteritis are discussed along with their symptomatology and clinical manifestations. Because of the importance of a proper diagnosis, the more common ophthalmoscopic pictures that are confused with the central retinal artery occlusions are also included. A case report of a central retinal artery occlusion secondary to a carotid artery stenosis is presented to acquaint the optometrist to the need of further testing after a vascular accident to the eye.


The influence of pilocarpine and atropine on pentobarbital-induced nystagmus in the New Zealand white rabbit. Nystagmus, induced by intravenous pentobarbital in rabbits, increased in frequency and amplitude as a result of intravenous pilocarpine administration. In seven of nine animals anesthetized with pentobarbital but not showing eye movements, pilocarpine injection elicited nystagmus. In all rabbits, nystagmus was terminated by subsequent intravenous administration of atropine, indicating that the parasympathetic nervous system contributes to nystagmus observed in barbiturate treated animals. The results reported here are of value in their implication for an understanding of the physiologic mechanisms which underlie eye movement disorders commonly observed in barbituarate intoxicated individuals.


A definition of progressive power in ophthalmic lenses. Practitioners may now prescribe several progressive addition lenses. This article discusses and compares some individual progressive addition lenses available in America with regard to the important aspect of intermediate area vision, lateral boundaries and lateral distortions. Included are tips for comparing the wearability of different brands of lenses from viewing photographs of uniform grids as seen through the various progressive addition lenses.


The visual evoked responses: reliability revisited. To examine the reliability of VER data, responses were obtained from 9 normal subjects. For steady state and transient displays, 7 consecutive VERs were obtained using 10, 25, 50, 75 and 100 ensemble averaged 384 ms activity samples each. Data from the 7 VERs were averaged by considering the first 3, the first 5, and all 7 VERs. For each display, maximum reliability was obtained by averaging at least 5 VERs with each consisting of 50 or more ensemble averaged samples. The steady state display produced more reliable data than did the transient display, but when each display system was used in a refraction format, the transient display produced refractions with narrower uncertainty ranges.


The blindspot syndrome.

The blindspot syndrome. Constant esotropia, with its accompanying sensorial anomalies, generally presents a poor prognosis for functional recovery of binocular vision. The blindspot syndrome presents an exception to this. The present paper suggests methods for the diagnosis and an approach to the management of this condition.


[Scanning electron microscopy in malignant uveal melanomas (author's transl)]. Four malignant uveal melanomas, of which two were of fascicular (subtype B) type one of epithelioid type and one of mixed-type, were examined under a scanning electron microscope. Within the tumors, we can distinguish cells having long cytoplasmatic processes and cells without processes, which correspond to the fusiform and epithelioid cells respectively. The cells also show a more or less marked development of the microvillosities of the cell surface.


[Use of timolol in treatment of increased intra-ocular pressure following surgery of congenital glaucoma (author's transl)]. In 16 patients from 9 to 34 year old, whose intraocular pressure remained elevated after a surgical procedure against congenital glaucoma, a timolol collyriam of 0.25 or 0.50 concentration was used as first topic treatment. Success was obtained only in 15% of the cuses. Better result followed systemic use of sulfonamid together with timolol. Nevertheless, medical treatment of these residual overpressures is still difficult. It showld be controlled every three months, paying much attention to the diary intraocular pressure curve.


[The allergic conjunctivitis (author's transl)]. The authors report the study of 51 cases of conjunctivitis which the allergic character has been showed. They emphasize: 1. the special frequency with the young person (between 20 and 30 years for allergic conjunctivitis, generally before 7 years for vernal conjunctivitis); 2. the importance of atopic ground; 3. the weak incidence of business; 4. the difficulty of diagnosis, because the monosensibilisations are uncommon; 5. the favourable result of treatment.


[Study of colour vision and visual evoked responses in multisclerosis diagnosis (author's transl)]. In a patient with suspected Multisclerosis (M.S.), the discovery of a lesion in the anterior optic tracks is of considerable diagnostic importance. If none of the classical clinical signs of optic neuritis can be found, the study of visual evoked responses (VER) and of colour vision is useful evidence for diagnosis. In a population of 102 patients having "possible", "probable" or "confirmed" M.S, we have compared the information provided by both these methods. 27 patients had MS with a known optic neuritis: the VER and colour vision of all of them was altered, either unilaterally or bilaterally. 75 patients had "possible" or "probable" MS without a history of optic neuritis. For 34,7%, the discovery of a dyschromatopsia showed a lesion in the optic nerve. In 68%, only the increased latency in VER demonstrated an optic neuritis. It should be noted that for all the patients with "probable" or "confirmed" MS, the VER latency was increased. The study of colour vision is therefore in our opinion, an excellent way of investigating anterior optic tracks lesions. When the study of colour vision is not sufficient, the recording of VER is a reliable technique and a very valuable acquisition in neuro-ophthalmology.


[Experimental alpha-chymotrypsin model of glaucoma in the rabbit: histopathological studies (author's transl)]. The injection of alpha-chymotrypsin into the posterior chamber of the eye is known to produce an experimental ocular hypertension of long duration in animals. The present study reports the pathological changes which occur in the eye during the first nine months after the ocular injection of alpha-chymotrypsin in rabbits. Six weeks after treatment most of the eyes showed a buphthalmia and an intraocular pressure elevation which varied greatly from animal to animal. The anterior chamber angle of the treated eyes showed a progressive enlargement. Several days after the enzyme injection a transient increase in thickness of the cornea and Descemet membrane was noted. Cupping of the optic disc, characterized by a total disappearance of the optic nerve head fibers and an excavation beginning at margins of the retina appeared after four months and in most cases were present seven months after the treatment. More or less prominent retinal degeneration was also evidenced three months after enzyme injection. The results indicate alpha-chymotrypsin-induced occular hypertension in the rabbit leads after several months to pathological change in the eye analogous to that observed in human glaucoma.


Accountability in health care: an essay on mechanisms, muddles, and mires. This paper presents a critical evaluation of several theories of accountability and their applicability to health care concerns. The authors first provide a preliminary refinement of the imprecise concept of accountability itself and then examine four major types (political; bureaucratic; professional; and economic-consumer). Then, by using disciplinary perspectives provided by several schools of thought in political science (legislative supremacy; general manager theory; government by bureaucracy; objective responsibility; citizen participation), they discuss the degree of accountability presently found in various American health policies. After identifying the inherent dilemmmas within any credible accountability approach to health care programs as now utilized in the United States, the authors recommend that all types of accountability be integrated and strengthened by relying more explicitly on practices characteristic of development administration.


The politics of hospital payment.

The politics of hospital payment. This paper analyzes the politics of hospital payment over the last decade. The authors explain how provider interests and judgments became a standard for appropriate hospital payment: the impact of that standard on hospital costs; and the political obstacles to imposing an alternative standard and controlling hospital costs. The authors draw lessons from this experience, here and in other countries, to propose an alternative approach to hospital payment that would allow policymakers, accountable to the public, to make explicit choices about the level and nature of hospital expenditures.


Ideology, class and the National Health Service. Since the start of the British National Health Service, disputes between the government and the medical profession have become formalized battles with well-recognized rules. But between 1974 and 1976 the consensus underlying the conflict was challenged by the Labour Government's policy on private practice and pay beds. This paper examines the course of the conflict and analyzes the factors underlying the eruption of this issue. It draws attention to the role of the trade-unions in activating the Labour Party's latent ideological commitment on private practice. Although the issue appears to conform to a class-conflict model, this simple symmetry becomes blurred on closer analysis. In conclusion the paper argues that while socio-structural factors extrinsic to the health service explain the appearance of private practice on the political agenda, it is factors endogenous to the NHS which explain the outcome of the dispute. In turn, however, these endogenous factors have little to do with the fact that the NHS is delivering a commodity called "health." Instead, what is important is that the NHS is a complex organization and, as such, depends on the co-operation of a variety of groups--ranging from the medical profession to laundry workers. The analysis, therefore, concludes that the power of the medical profession derives not from its elite status but from its position as an organized group in a complex industry.


Public capabilities and health care effectiveness: implications from a comparative perspective. This article examines inter-relationship between "centers" and "peripheries" within political, professional and health care systems. It seeks to determine which conditions tend to improve the capacity of public authorities to further such measures of effectiveness as access to, quality of, and complementarity of health care delivery. Examples are selected from the experience of the United States and West European countries.


Diagnosis and the dole: the function of illness in American distributive politics. This article argues that the concept of illness has certain properties that make it a convenient administrative device for managing a need-based redistributive system in a society whose primary distributive system is based on work. These properties--cultural acceptance of illness as a legitimate excuse for not working, objective standards for identifying illness, and restrictiveness--have led to the widespread use of illness as an eligibility criterion for many social benefits, including cash transfers, services, privileges and exemptions. Paradoxically, the traditional rationales for using illness as one of the keystones of categorical welfare policy are eroding, yet welfare programs based on illness certification are growing rapidly. To explain this anomaly, the author suggests that medical certification as a distributive mechanisms serves certain latent political functions, such as allowing welfare programs to be responsive to political unrest, siphoning off opposition to controversial policies by the granting of medical exemptions to intense opponents, are reducing political conflict by using physicians as arbiters.


Why is regulation introduced in the health sector? A look at occupational licensure. Economic theories suggest that the introduction of regulation can be analyzed in terms of the magnitude and distribution of its economic impact. This article uses this approach to consider the introduction of licensure in the health sector for clinical laboratory personnel. At the micro level, there is no evidence of active consumer support for licensure and it seems to have been introduced mainly at the behest of members of the occupation and bureaucrats involved in the regulation of laboratories. Bureaucrats appear to have acted largely on their own initiative and are the single most important group involved in the introduction of licensure. The large role of the occupation supports a "producer protection" model of licensure over a "consumer protection" model. But the independent role of bureaucrats suggests that actors in the public sector are also a major interest group who need to be included in any model of regulation. Their motives are complex, but in the past one of the attractions of licensure seems to have been low direct administrative costs, despite large indirect costs to consumers. At the macro level, recent changes in social policy, which may reflect broad class interests, have shifted these indirect costs increasingly to the public sector through programs like Medicare. These changes in the distribution of costs may explain a growing concern by bureaucrats about the efficiency of licensure and a shift away from this type of regulation.


Podocytes in aminonucleoside glomerulonephritis investigated ultrastructurally with concanavalin A. Peroxidase labeled concanavalin A (Con A) permits the detection of some saccharide determinants. This histochemical technique permits the visualization of cellular pathological modifications not observed with other methods. Its use in an ultrastructural study of nephritis induced by a single injection of aminonucleoside demonstrated the following in podocytes. The Con A positive endoplasmic reticulum (ER), essentially the rough ER, lost its normal linear and network appearance to take on a dot dash pattern. ER contents but not attached ribosomes and membranes were Con A positive. The dot dash pattern, due to a fragmentation of the ER, appeared prior to the onset of proteinuria and was attenuated before the disappearance of proteinuria. These changes of the ER were not observed in other proteinuric states. This suggests that aminonucleoside can damage the synthesis apparatus of podocytes, revealed by the Con A method.


Separation of resting and proliferating granulocytic precursors. We have obtained cells in various stages of granulocytic development by a combination of isopycnic separation and electronic cell sorting. Not only were immature cells (blast cells, promyelocytes and myelocytes) separated from mature cells (bands and polys), but the immature cells were separated into proliferating (S + G2 + M) and resting (Go/G1) compartments of the cell cycle. This permits the study of the morphological and biochemical changes associated with development apart from those changes associated with proliferation.


Prediction of symptoms and illness behaviour from measures of life change and verbalized depressive themes. A new measure of depressiveness in speech content and the Schedule of Recent Experiences are used to predict illness reports and clinic use in two samples of subjects. The results suggest that the more life change the subjects reported, the more depressiveness they verbalized, and that both life change and depressiveness scores predict illness reports and health service users. Multivariate combinations of the measures of life change and depressivenss gave better predictions than either measure alone, and the measure of depressiveness for the most part gave somewhat better predictions than the life change measure. This suggest that it is important to quantify reactions to life events. In addition, it suggests that the two longstanding currents of interest in psychosomatic medicine which concern the importance of life events on the one hand and of affective and intrapsychic events on the other can profitably be integrated.


Interpersonal interaction and cardiovascular response in type A subjects and coronary patients. The present study tested the hypothesis that Type A subjects respond with greater cardiovascular response than Type B subjects during the structured interview used to assess the Type A pattern. Coronary patients (n = 31) and patient controls (n = 33) were subjected to the interview and a history quiz while ECG and blood pressure were monitored. As predicted, Type A relative to Type B subjects evidenced significantly greater increases in both systolic and diastolic blood pressure, which were sustained over the course of the entire 12-15 minute interview. Type A subjects compared with B's also showed significantly greater blood pressure elevations during the quiz. Coronary patients displayed significantly greater Type A attributes than control subjects and tended to show greater blood pressure elevations than controls during the interview. In addition, the quiz induced significant elevations in the blood pressure of coronary patients, but not patient controls, over that displayed during the interview, despite the presence of beta-adrenergic blocking medication. Implications of the findings for coronary-prone behavior and coronary heart disease are discussed.


Psychosocial modifiers of response to stress. The impact of stress upon an organism is far more complex than the simple design of most stress research implies. We offer an expanded model for studying the relation of stressors to pathological outcomes, which takes into account both the adaptive capacity of the organism before the stressor occurs and the defenses marshalled in response to the stressor. The model also distinguishes among the initial responses of alarm, sustained defensive behaviors, and the relatively irreversible endstates which remain after resistance has ended. Realizing that only a multidiscomplinary approach can begin to capture the wholeness of human experience, this research paradigm anticipates that stressors, adaptive capacities, defenses, alarm reactions, and pathologial end-states will take place at the biological, psychological, interpersonal and sociocultural levels simultaneously and successively. Data on life change stress and psychological health outcomes gathered as part of the Air Traffic Controller Health Change Study are analyzed to illustrate the use of the model in identifying psychosocial and biological modifiers of response to stress.


The type A behavior pattern: a critical assessment. Research on the Type A (coronary-prone)behavior pattern has proliferated at a rapid rate in recent years. With the cardiovascular risk value of Type A behavior well established, many studies have focused on reliability, validity, and other essentially psychological and psychometric issues. These studies are evaluated, along with the fundamental assumptions underlying the construct. Further research is suggested which examines the comparative predictive validity of Type A behavior and its defining criteria across diverse populations and the interaction of stress and behavior pattern.


Food and cancer.

Food and cancer. There are good reasons to suspect that the quantity and quality of food influence both the overall risk of development of many forms of cancer and the types of cancer which occur most commonly. The evidence is briefly reviewed and the kinds of mechanisms that may be responsible listed. The striking effects of dietary restriction on cancer risk in laboratory rats and mice and the possibility that dietary restraint may be beneficial in man are discussed. Recent laboratory evidence that carcinogens may be formed in food during cooking is mentioned. Finally, the importance of avoiding mineral imbalance when conducting animal studies designed to evaluate the safety of food constituents and additives is stressed in relation to urinary-calculus formation and bladder-tumour risk.


EEC food policies.

EEC food policies. The EEC common agricultural policy (CAP) is examined as a food policy, including the adequacy of its response to consumers' needs; the suggestion is made that, although some successes can be claimed, the overall picture is not satisfactory. Some of the work on food standards within the EEC is recorded, and attention is drawn to the nutritional aspects of CAP and to the implications of EEC actions for world food policy.


Developing new food products.

Developing new food products. Stages of developing a new food product - market research, product development, adaptation to factory production, test marketing, national marketing, and advertising--are described. It is shown that no product is successful if not liked by potential purchasers. If the dietitian wishes to market nutrition education successfully this must be done by taking food habits into consideration, influencing them perhaps, but not attempting to reverse trends.


The dietetic and nutritional significance of textured vegetable protein (TVP). A review of the limited success attained by TVP implies that it may be due partly to the failure of those manufacturing it to attain a sufficiently appealing aesthetic standard and partly to the fact that since its invention it has become apparent that protein deficiency, which would justify its incorporation in the diet, is comparatively rare among the communities where TVP can profitably be marketed.


Restriction of weight gain in pregnancy: is it justified? The management of pregnant women seems always to have contained a component of dietary constraint, but today two claims are made for restricting weight gain: that it reduces the risk of pre-eclampsia, and of middle-aged obesity. Neither claim can be sustained and there would appear to be no case for the technically difficult effort required to limit weight gain in pregnancy.


A sensitive microassay for the murine alternative complement pathway. A microhemolytic assay for measurement of murine alternative complement pathway activity is described. The assay uses 51Cr release from neuraminidase-treated rabbit erythrocytes incubated with Mg2+ EGTA-chelated murine serum. Neuraminidase pretreatment of rabbit erythrocytes increases the sensitivity of the assay 8--10-fold, enable the use of small volumes of individual mouse sera. The assay affords a simple, sensitive and reproducible method for measuring murine alternative complement pathway activity. Significant differences were found between strains alternative complement pathway activity of serum from various inbred murine lines was measured.


A microprocessor-controlled assay for the estimation of human placental lactogen. A radioimmunoassay for human placental lactogen (HPL) is described using the KEMTEK 3000, which is a modular radioimmunoassay apparatus controlled by a microprocessor. Operation of the KEMTEK 3000 is largely automatic and it requires minimal intervention from the operator. It is capable of 300 reactions per hour so that a large number of estimations can readily be performed. HPL was assayed by a double antibody method on serum samples from pregnant women and patients with trophoblastic tumours.


Use and functional properties of peripheral blood lymphocytes in mice. Peripheral blood lymphocytes (PBL) were isolated and examined for their ability to respond in vitro to H-2 and H-Y antigens and also to hapten conjugated syngeneic cells. In addition, these lymphocytes were tested as antigen and target cells in in vitro mixed lymphocyte reaction and in chromium release cell mediated lympholysis respectively, as well as serving as targets for the H-2 typing of chimeric mice. Two methods were used to isolate the lymphocytes: a density gradient separation and a double water lysis technique. PBL, prepared by either method compared favourably with splenic lymphocytes in all aspects of anti-H-2 cytotoxicity but could not be used as responder for anti-H-Y cytotoxicity. In addition a method has been developed using PBL as targets for H-2 typing of both allophenic and irradiation chimeric mice. The small numbers of cells required for each of these procedures allows for the preselection of suitable mice and/or multiple experimental determinations on individual mice.


Quantitation of the membrane attack complex of complement in an air-driven ultracentrifuge. A sensitive assay of complement (C) activation via either the classical or alternative pathway was developed by evaluating assembly of the terminal complexes (C5b-9)2 or SC5b-9. Activation of serum containing [125I]C7 resulted in the formation of a stable, radiolabeled complex which was separable from its precursors by sedimentation in an air-driven ultracentrifuge. The radioactivity in the sediment was directly proportional to the amount of complex formed and assembly of the complex could be detected after C activation by aggregated IgG in concentrations as low as 10 micrograms/ml. Mild detergents such as Triton X-100 could be included in the reaction mixture, because they affected neither the assembly nor the integrity of the complexes. The assay, which detects both assembly of the membrane attack complex (MAC or (C5b-9)2) on target membranes and formation of SC5b-9 in fluid phase, measures the potential of certain substances to trigger the cytolytic phase of C regardless of whether the classical or alternative pathway was activated. However, by using serum depleted of either factor B or C1q, activation of either pathway can be assessed individually.


Genetic control of survival in epidemics. Descendants of Dutch colonists, who emigrated to Surinam in the last century and survived epidemics of typhoid and yellow fever with a total mortality of about 60%, were tested for twenty-six polymorphisms. The gene frequencies were compared with those of a large Dutch control sample. An analysis of drift indicated that the variations in gene frequencies observed for C3, Gm, HLA-B, and GLO were unlikely to be due to drift. Therefore these data might indicate selection through genetic control of survival in these epidemics.


Two apparently healthy Japanese individuals of type MkMk have erythrocytes which lack both the blood group MN and Ss-active sialoglycoproteins. A Japanese blood donor (H. T.) and his brother (M. S.) are the first homozygous MkMk individuals described; their red cells lack, as expected, known antigens of the MNSs blood group system and also have no demonstrable MN-active and Ss-active glycoproteins. Both MkMk individuals have a naturally occurring atypical antibody in their serum. The antibody in the serum of H. T. is inhibited by MNSs-active glycoprotein preparations from normal erythrocytes.


H-Y antigen: genetic control of the expression as detected by host-versus-graft popliteal lymph node enlargement assay maps between the T and H-2 complexes. We are using the terms 'low' and 'high' expression when the H-Y antigen on thymocytes of mouse parental strains is, respectively, weakly and strongly immunogenic for F1 hybrids in a host-versus-graft popliteal lymph node enlargement assay. Using this assay we attempted to locate the genetic factor(s) responsible for the control of H-Y expression within chromosome 17 since our previous study indicated linkage with the H-2 complex. We produced to this aim recombinants from (B10.T X C3H/Di)F1 hybrids where crossing over took place between H-2 and T complexes. In this way we were able to locate a gene denoted Hye (for H-Y expression) whose 'high' and 'low' alleles originated, respectively, from the B10 and C3H/Di strains. In the recombinants, the expression did not follow the H-2 haplotype, but obviously depended on the position of crossing over between H-2 and T. This pointed to the Hye gene mapping proximally from the H-2 complex.


Thymus and the endocrine system: ovarian dysgenesis in neonatally thymectomized rats. By 10 days after neonatal thymectomy, the areas of lymphocytic depletion were being repopulated by plasma or reticular cells. Subsequently, ovarian dysgenesis was observed in 50-day-old thymectomized female rats as hyperplasia of ovarian interstitial cells an an enhanced degeneration of follicles. Thymectomized rats at 130 and 170 days of age showed complete ovarian dysgenesis, testicular atrophy, hypertrophy of pituitary beta-cells with pronounced cytoplasmic haloes, and lymphocytic infiltration in the pituitary, thyroid and prostate glands. These results suggest that neonatal thymectomy may initially influence the lymphoid organs (i.e. the immune system) and that changes in the immune system may result in the autoimmune-like damage in the endocrine organs and the prostate gland. Associated with these changes, the concentrations of plasma progesterone and 17 alpha-hydroxyprogesterone were significantly reduced in 130-day-old thymectomized female rats with respect to the sham-thymectomized controls. The concentration of plasma oestradiol-17 beta in thymectomized female rats was the same as in sham-thymectomized female rats. These results suggest that gestagens may normally suppress immune responses but that, in the case of thymectomized female rats, the reduced levels of gestagens may lead to enhanced immune responses.


Somatomedin-like activity in plasma after foetal hypophysectomy or nephrectomy and in experimental intra-uterine growth retardation in sheep. Plasma samples from pregnant ewes and their foetuses during the last quarter of gestation were assayed for somatomedin-like activity (SLA) using the procine costal cartilage assay. In maternal plasma, the mean potency (compared with pooled serum from six sheep) was 0.84 +/- 0.05 (S.E.M.) units/ml (n = 15). Somatomedin-like activity in the plasma of five control foetuses (0.91 +/- 0.1 units/ml) was similar to the maternal levels and did not change with gestational age. After foetal hypophysectomy the SLA in foetal plasma (0.37 +/- 0.05 units/ml, n = 4) was significantly less than in control animals. In two nephrectomized foetuses, the mean SLA in plasma (0.08 and 0.51 units/ml respectively) was less than in control animals. Retardation of intra-uterine foetal growth was induced by removal of endometrial caruncles before pregnancy in four sheep. The SLA in plasma from these foetuses was 0.38 +/- 0.05 units/ml (P less than 0.01 v. control animals). The results suggest that SLA in the foetus may be important in the regulation of foetal growth, but they also indicate that factors other than growth hormone may be important in the control of SLA in foetal plasma.


Serum prolactin levels in castrated rams at various times of the year and during treatment with androgens or oestrogen. Prolactin concentrations were measured in serum from wethers at various times of the year before and during treatment with testosterone proprionate, dihydrotestosterone propionate, 19-hydroxytestosterone dipropionate and oestradiol dipropionate. Levels of prolactin in serum were lower in untreated wethers during short (October) than during long (April-August) days. Seasonal differences persisted throughout the experiment but became less obvious during tretment with oestradiol dipropionate and 19-hydroxytestosterone dipropionate, both of which raised prolactin concentrations. Neither testosterone propionate nor dihydrotestosterone propionate altered the levels of prolactin.


Serum prolactin in the male mouse from birth to maturity. The pattern of prolactin secretion was determined throughout the development of the male mouse. Levels of prolactin were at their lowest from birth to 20 days of age. A dramatic increase in serum prolactin occurred during pubertal maturation coincident with rapid growth of the accessory organ system. These events preceded the pubertal rise in the level of serum testosterone that is characteristics of this species.


Concentration of 5-methoxytryptophol in pineal gland and plasma of the rat. 5-Methoxytryptophol, a serotonin metabolite, was measured by gas chromatography-mass spectrometry in pineal glands, plasma and control tissues (cerebral cortex and salivary glands) from male rats kept in a controlled lighting environment. In the pineal gland the level of 5-methoxytryptophol was significantly higher during the dark period than during the light, the absolute levels being an order of magnitude less than those of melatonin. In the plasma, the levels showed a reverse situation with respect to lighting conditions. No correlation was found between the 5-methoxytryptophol levels in plasma and the pineal gland in individual animals. These results suggest that there is no obvious correlation between pineal content and pineal activity. This may be due to a combination of rapid turnover, secretion and/or peripheral conversion of another 5-methoxyindole to 5-methoxytryptophol.


Hormone replacement therapy in the menopause: a suitable animal model. Female CBA mice, aged 11 months, were treated cyclically with oral ethynyl oestradiol or oestrone sulphate for 3 months. The ovaries of all animals appeared to be atrophied. Target tissues throughout the genital tract showed a response to both oestrogens. Electron microscopy of both the endometrium and the urothelium demonstrated morphological changes characteristic of increased cellular metabolic activity in the treated mice. Endometrial hyperplasia developed in both treatment groups but more pronounced epithelial changes occurred with oestrone sulphate. This hyperplasia was accompanied by a doubling in the number of uterine cytoplasmic oestrogen receptors. A 50% fall in serum levels of luteinizing hormone in the treated mice revealed that the hypothalamic-pituitary system was still intact. Both oestrogens improved skeletal balance by changes in cortical-endosteal bone remodelling. The results suggest that the CBA strain of mouse is a suitable model for the study of the human climacteric and its response to hormone replacement therapy.


Measurement of the integrated concentration of prolactin in normal subjects and patients with hyperprolactinaemia. To determine whether the fluctuations in the concentration of prolactin in plasma of man affect diagnostic procedures, the integrated concentration of prolactin has been compared with a basal concentration. A continuous sampling apparatus was used to study nine normal subjects and 12 subjects with features of the hyperprolactinaemia syndrome. Small differences were demonstrated, which were, however, neither statistically significant nor likely to influence clinical decisions. It is concluded that single estimations of the concentration of prolactin in blood, taken under resting conditions, are adequate for routine diagnostic use.


Concentrations of 6-oxo-prostaglandin F 1 alpha in the maternal and foetal plasma of sheep during spontaneous and induced parturition. The concentrations of 6-oxo-prostaglandin F 1 alpha (6-oxo-PGF 1 alpha) have been determined in maternal and foetal plasma from nine chronically catheterized sheep during late pregnancy and parturition. Labour occurred either spontaneously (three sheep) or was induced by continous intrafoetal infusion of Synacthen (ACTH 1-24; 0.24 mg/24 h; three sheep) or dexamethasone (1 mg/24 h; three sheep). During spontaneous and Synacthen-induced parturition, concentrations of 6-oxo-PGF 1 alpha in maternal and foetal plasma remained at basal levels until 24 h before delivery. At varying times during the 24 h before delivery, levels of 6-oxo-PGF 1 alpha in maternal and foetal plasma were generally increased. When parturition was induced with dexamethasone, however, no increase was observed in the foetal plasma although the concentration of 6-oxo-PGF 1 alpha in maternal plasma was raised close to delivery.


Action of oestrogens and antioestrogens on oestrogen-inducible cytoplasmic and androgen-inducible microsomal activity of 3 alpha-hydroxysteroid dehydrogenase in male rat kidney. The influence of steroidal and non-steroidal antioestrogenic compounds on the effect of systemically administered oestradiol (OE2) and diethylstilboestrol (DES) was investigated in adult male rats with intact gonads. In this animal model, oestrogens induced the NADP-dependent cytoplasmic activity and prevented the inductive action of androgens on NADP-dependent microsomal activity of renal 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSDH). Simultaneous administration of tamoxifen (0.5 mg/day) with OE2 (5 microgram/day) or DES (10 microgram/day) for 10 days completely blocked the inductive effect of OE2 on cytoplasmic 3 alpha-HSDH, whereas, in the case of the microsomal enzyme, the repressive effects of OE2 and DES were antagonized only to 28 and 16% respectively. Simultaneous administration of 5 alpha-dihydrotestosterone (DHT; 0.5 mg/day) for 10 days antagonized the inductive effect of OE2 on the cytoplasmic enzyme activity to 86% and completely by-passed the repressive effects of OE2 and DES on the microsomal enzyme activity. It is concluded that oestrogenic induction of renal cytoplasmic 3 alpha-HSDH involves an oestrogen receptor mechanism which, in this animal model, can be antagonized by tamoxifen. In contrast, oestrogenic repression of renal microsomal 3 alpha-HSDH is obviously the consequence of the strong antigonadotrophic activity of oestrogens leading to subsequent repression of testicular androgen secretion by mechanisms which can be only weakly antagonized by tamoxifen. Exogenous DHT, even in the presence of OE2 or DES, completely compensates for this centrally mediated deficit of peripheral androgen.


Relaxin inhibits spontaneous and prostaglandin-driven myometrial activity in anaesthetized rats. Porcine relaxin (250 guinea-pig units/mg) infused intravenously into anaesthetized rats at 20 micrograms/h reversibly abolished spontaneous intra-uterine pressure cycles yet left the myometrium responsive to oxytocin in doses of 4--8 mu. The inhibition was found to be primarily of the frequency, rather than of the amplitude, of pressure cycles. Relaxin (5 or 10 micrograms) was capable of completely suppressing uterine activity driven by prostaglandin F2 alpha infusion in oestrogen-treated ovariectomized rats. Whereas the beta-adrenergic blocker, propranolol, had no effect on relaxin-induced inhibition, phentolamine, an alpha-blocker, significantly delayed the relaxin effect. It is unlikely, however, that relaxin operates through an alpha-inhibitory receptor. The results show that relaxin acts primarily as a frequency modulator and is capable of antagonizing an exogenous myometrial stimulant.


Effect of neonatal administration of thyroxine on the rate of sebum production in rats. Newborn Sprague-Dawley rats of both sexes were treated with 28 micrograms thyroxine (T4) daily for the first week of life. At the age of 80 days, the secretion rate of sebum was measured from the amount of skin-surface lipids extractable by acetone and which had been produced during 2 days. Treatment with such excess amounts of T4 during the early postnatal period significantly reduced the production of sebum in both male and female rats when compared with control rats and with rats deprived of food early in life. The thyroid, the pituitary gland, the testes and the seminal vesicles were significantly smaller but the weights of the ovaries and uteri remained relatively unaffected. There was a similar ratio of sex difference in the rate of sebum secretion irrespective of treatment. It is suggested that a reduction of sebaceous response in rats made thyrotoxic with large doses of T4 early in life was probably due to a decreased secretion of thyroid hormone which is required to maintain normal activity of the sebaceous glands.


Metabolism of testosterone by the epithelium and mesenchyme of the rat urogenital sinus. Testosterone metabolism was measured in separated epithelium and mesenchyme from the urogenital sinuses of 17- and 19-day-old male and female rat embryos and compared with testosterone metabolism in the intact sinus. Both the epithelium and the mesenchyme converted testosterone to 5 alpha-dihydrotestosterone. The epithelium produced much more androstanedione and androsterone but less 3 alpha, 17 beta-androstanediol than did the mesenchyme. The whole sinus synthesized all four metabolites, but in different proportions, producing relatively more androsterone than either of its two component tissues. These data suggest that androsterone is formed by the joint action of epithelium and mesenchyme. Metabolism of testosterone did not differ with sex or foetal age in either of the separated tissues or in the intact sinus, implying that the failure of urogenital mesenchyme from 19-day-old female foetuses to induce prostatic morphogenesis is not due to the loss of 5 alpha-reductase. It is suggested that this lack of inductive capacity may be attributable to a decline in androgen levels with age in female mesenchyme.


Stimulation of cartilage zones of the calf costochondral growth plate in vitro by growth hormone dependent rat plasma somatomedin activity. The actions of rat plasma somatomedin activity dependent on growth hormone were investigated in vitro on separated zones of cartilage from the calf costochondral junction. Plasma somatomedin maximally stimulated the uptake of[3H]thymidine into cartilage cells of the proliferating region. Cartilage deeper in the growth plate possessed the highest uptake of [35S]sulphate which was also stimulated by somatomedin. Somatomedin, therefore, appears to promote both cell replication and matrix synthesis throughout the growth plate cartilage although the two processes were greatest in different cartilage regions. Growth hormone or tri-iodothyronine did not directly alter the uptake of either isotope into the growth plate cartilage.


Acute effects of aldosterone on water and electrolyte transport in the colon and coprodeum of the domestic fowl (Gallus domesticus) in vivo. White Leghorn laying hens were maintained on commercial poultry food (medium-Na+ diet) and fresh water. High-Na+ diet birds received, in addition, 10 ml 9% (w/v) NaCl/kg by stomach load for 2 days before perfusion experiments. The lumen of the coprodeum and colon of anaesthetized birds was perfused with a hyperosmotic solution resembling ureteral urine. Transmural solute and water fluxes and potential difference (p.d.) values were measured for 2.5 h before and for 8 h after i.v. injection of aldosterone (120 microgram/kg). After administration of aldosterone, the lag, increasing and stabilized plateau phases were identified for Na+, K+ and Cl- fluxes (which together formed an electroneutral ion-exchange system); plateau flux values were significantly greater than preinjection values and were comparable to values for birds maintained on low-Na+ diets in parallel experiments. Ammonium, phosphate and water fluxes were unresponsive to aldosterone and p.d. values showed a transient increase in medium-Na+ diet birds only. In parallel experiments on birds on low sodium diets the ammonium flux and p.d. increased but the osmotic flow and phosphate transfer did not respond. Therefore acute injection of aldosterone reproduced some but not all of the responses to dietary Na+ restriction in fowls.


Chronic aldosterone therapy and the control of transepithelial transport of ions and water by the colon and coprodeum of the domestic fowl (Gallus domesticus) in vivo. White Leghorn laying hens were maintained on commercial poultry food (medium-Na+ diet) and fresh water. Birds maintained on a high-Na+ diet received, in addition, 10 ml 9% (w/v) NaCl/kg by stomach load for 2 days before the perfusion experiments. Some birds on each dietary Na+ level also received aldosterone injections (60 micrograms/kg per day, i.m.) for 2 days before the perfusion experiments. The lumen of the coprodeum and colon of anaesthetized birds was perfused with solutions resembling ureteral urine, with systematically varied Na+, NH4+, Cl- and osmotic concentrations. Aldosterone enhanced net Na+ absorption (JNa) and associated net Cl- absorption and K+ secretion, and induced (in birds on medium- but not on high-Na+ diets) the appearance of a saturable JNa component dependent on the luminal concentration of Na+. Aldosterone enhanced net absorption of NH4+ and decreased the transmural potential difference in birds on a high-Na+ diet only; water and phosphate fluxes were not affected. Disparities between aldosterone- and Na+-depletion-induced effects suggested that one or more factors (in addition to aldosterone) are involved in the normal mediation of the responses of the lower intestine of the domestic fowl to varied Na+ intake.


A sexually dimorphic rhythm in oestradiol-activated lordosis behaviour in the rat. Ovariectomized rats exposed to constant plasma levels of oestradiol showed a daily rhythm in lordosis behaviour, with high levels of lordosis occurring during the dark portion of the daily light: darkness cycle and low levels during the light period. Similarly treated male rats failed to show a rhythm in lordosis behaviour. However, neonatal castration permitted the expression of the lordosis rhythm in male rats; conversely, an injection of 1.25 mg testosterone propionate on day 4 of life abolished the rhythm in female rats. Pinealectomy, adrenalectomy or depletion of brain 5-hydroxytryptamine levels did not affect the periodicity in lordosis behaviour but lesions in the suprachiasmatic nuclei of the hypothalamus disrupted the rhythm. It is suggested that the daily rhythm in lordosis behaviour participates in the control of the termination of heat in the female rat and that the perinatal hormone milieu may exert permanent effects on periodic functions.


Ultrastructural studies of lethal c25H/C25H mouse embryos. Mouse embryos which are homozygous for the c25H deletion at the albino locus are developmentally arrested at the 2- to 6-cell cleavage stages. This study reveals that the mutant embryos cease development before they can be distinguished ultrastructurally from their normal litter-mates. After prolonged developmental delay (24--48 h), the nuclei of the mutant embryos become extremely aberrant in shape, whereas other subcellular organelles remain normal and there are no signs of pyknosis. Eventually, the mutant embryos do become pyknotic and begin to degenerate. The striking effects of this deletion on nuclear ultrastructure of cleavage-stage embryos are discussed in relation to biochemical and ultrastructural defects caused by other lethal deletions at the albino locus.