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Biomedical subjects

R Goldstein

Publications and source records attributed to R Goldstein.

394 records · Page 22Linked to original sources
PubMedDate not supplied

The effects of polyunsaturated fatty acids (PUFAs) on the sleep parameters of the rat pups.

In order to verify the hypothesis that at least during perinatal life the amount of active sleep (AS) is dependent on the level of the brain maturation, newborn rats received by an i.p. route for 6 days, a polyunsaturated fatty acid (PUFAs) preparation (Vitamin F) in doses of 1, 10 and 100 mg/day. In comparison with diluent alone injected controls, the PUFAs-injected animals presented a decrease in the AS percentage, decrease which was proportional with the dose. In parallel, it was noted a dose-dependent increase in mortality from 10% for 1 to 90% for 100 mg of PUFAs. We concluded that the PUFAs which greatly stimulate the synaptogenesis, enhance the release of a membrane component with a strong AS inhibiting effect, and, at least during perinatal life, the AS could be modulated by this factors and not by the classical neurotransmitters.

Animals↗
PubMedDate not supplied

Sleep-induced GH release in otherwise GH deficient children having short stature; a possibly new variant of GH neurosecretory dysfunction (GHND).

Sleep and exercise are considered physiologic stimuli of growth hormone (GH) release from the pituitary. They were used to some extent for the assessment of GH reserve in growth disorders of supposedly pituitary origin. In order to better establish the diagnostic value of the sleep test, we studied 34 children of both sexes aged 6-14 having various degrees of shortness of stature associated with bone age retardation (range of the latter: 3-10 years). Eight healthy controls of the same age were also subjected to the sleep test. The latter was begun at 10:00-11:00 a.m. generally in a dark room under polygraphic control. The subjects were fed a standard breakfast at 8:00-8:30 a.m. After thirty minutes of steep or after reaching the IVth stage of slow-wave sleep, the children were awakened and samples of venous blood for GH determinations were drawn. Two other GH reserve tests were also performed in other days, usually insulin-induced hypoglycemia and glycine intravenous loading. Except sleep, no other GH provocative tests were performed in controls. In normal GH reserve children (21/34) according to other tests, the sleep test was positive (i.e. peak values greater than 15 microU/ml) in 7 cases and the mean GH response was not significantly smaller than the peak recorded after insulin-induced hypoglycemia. In abnormal GH reserve, presumably hypopituitary children (13/34) according to other tests, the sleep confirmed the other tests in 8 cases. In five cases of clinically and endocrinologically "hypopituitary" dwarfism, the sleep test revealed a normal response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Intestinal fat malabsorption in the uremic rat.

In the past we have shown that patients with chronic renal failure (CRF) on hemodialysis show evidence of intestinal malabsorption of fat. The present study was designed to verify this finding in an animal model. Male rats weighing +/- 200 g were studied. Uremia (U) was induced by 2-stage subtotal (5/6) nephrectomy. Control (C) animals were sham-operated. Fat absorption was studied after 6 weeks of uremia with the oral fat loading test. Twenty percent intralipid (0.25 g/100 gBW) was given by gastric tube feeding to fasting animals and the appearance of chylomicrons (CHYL) and the rise of triglycerides (TG) in the serum was followed for 5 hrs. In order to isolate the effect of fat absorption, an additional group of U and C animals was pretreated with orotic acid and triton, thus blocking hepatic TG synthesis and neutralizing peripheral lipoprotein lipase activity. The absorption of CHYL was significantly (p less than 0.01) impaired in all U animals and averaged 43 and 70 percent of that of the C animals, 1 and 2 hrs after the load respectively. The rise in serum TG did not differ from C in mildly U animals (Scr 1.0 +/- 0.04). In the more severely uremic animals (Scr 2.6 +/- 0.2), however, pretreated with orotic acid and triton, the rise in serum TG was far less (p less than 0.01) than in C animals (111 +/- 26-903 +/- 111 delta % V.780 +/- 170-5032 +/- 746 delta %) 1 and 5 hrs after the load.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

REM sleep rebound after its suppression by vasotocin in cats.

Extremely small amounts (10(-4) pg) of synthetic arginine vasotocin (AVT) injected into the pineal recess of unanesthetized cats induced a continuous NREM sleep for about 60 minute and completely suppressed REM sleep for about 5 hours. The reappearance of the REM sleep following AVT administration occurred with a marked rebound, lasting for more than one hour. Since neither vasopressin nor oxytocin, at the same doses, were able to affect significantly the REM sleep, it is concluded that AVT is specifically involved in the modulation and/or circadian organization of the REM sleep.

Animals↗
PubMedDate not supplied

Effects of melatonin on maturational indices of the brain in rats.

In order to investigate the effects of the pineal indole melatonin upon the brain maturation, groups of 40 Wistar rats were treated (for 6 days) either with melatonin (100 micrograms/0.1 ml) or with diluent alone (0.1 ml). The brain development was investigated by following the weight, total lipids as well as the water content of the brain in rats of 12, 30, 40 days or of adult age. Whether in rats of 12 days of age, melatonin produced no significant effects on brain maturation, beginning with the 30th day of age, it increases the weight, total lipids as well as the water content of the brain. It is concluded that, since these effects are opposite to those reported for the pineal hormone arginine vasotocin, not only as aspect but also in the age of their appearance, the maturation of the rat brain could be under a double tonic control, one inhibitory (the fetal and neonatal pineal arginine vasotocin) and another stimulatory (the postnatal pineal melatonin).

Animals↗
PubMedDate not supplied

Vasotocin involvement in the maturation of the rat brain.

In order to investigate the effects of arginine vasotocin (AVT), (a pineal nonapeptide hormone) on the brain maturation, the sleep-wake cycle, the day of eyelids opening and the total brain lipids level were followed up in new-born rats receiving daily (between day 2 and 8 of life) 100 ng of synthetic AVT, arginine-vasopressin (AVP), oxytocin (OT) or 0.1 ml saline solution. While AVP and OT had no effect, AVT induced: 1) an increase in the amount of active sleep (AS); 2) a decrease in the brain weight and the total brain lipids, and 3) a delay in the eyelids opening. These findings demonstrate that chronic administration of AVT induces a delay in the brain maturation of the new-born rats. Association of low brain lipids with a high percentage of AS is a very useful index of brain maturation. It is suggested that the drop in the endogenous brain levels of AVT below a critical threshold might represent a hormonal signal for triggering the beginning of brain maturation in mammals.

Age Factors↗
PubMedDate not supplied

The Wolf-Hirschhorn syndrome. New endocrine data.

A little girl with the Wolf-Hirschhorn syndrome showing a characteristic essential insomnia was examined clinically, genetically and hormonally. The values of arginin-vasotocin (AVT) implied in producing paradoxical sleep were normal. The relationship between AVT and insomnia is discussed.

Child, Preschool↗
PubMedDate not supplied

Middle components of human auditory averaged electroencephalic response: waveform variations during averaging.

The bases for variations of the middle-component (8-50 ms) auditory averaged electroencephalic response (AER) to clicks during the averaging process were explored by examining (1) the trend of the mean variance of the averaged waveform, (2) averaged waveforms generated by successive blocks of stimuli fractioned from a total of 512 stimuli, and (3) averaged waveforms generated by successive, but partially overlapping, blocks of responses recorded for a train of 512 stimuli. These analyses indicated no systematic changes in peak latencies or peak-to-peak amplitudes as stimulation progressed. Fluctuations in middle AER waveform are more readily explained by non-stationarity of the background electrophysiologic noise. Previously reported amplitude reduction with increasing stimulus number possibly can be explained by progressive reduction of the background noise on which the consistent-amplitude middle components are superimposed.

Acoustic Stimulation↗
PubMedDate not supplied

HIV and hepatitis B infection and risk behavior in young gay and bisexual men.

OBJECTIVES: To estimate the prevalence of and identify risk factors for human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV) infections and unprotected anal intercourse among young homosexual and bisexual men. METHODS: The authors performed a cross-sectional analysis of data from a prospective cohort of 508 young gay and bisexual men ages 18-29. RESULTS: HIV-1 seroprevalence was 2.4%, with five (1.3%) of 390 college students and seven (6.0%) of 117 non-students infected. After adjusting for confounders, HIV-1 infection was associated with having a history of a sexually transmitted disease other than HIV-1 or hepatitis B. The prevalence of hepatitis B markers in unvaccinated men was 12.9%. The presence of hepatitis B markers in unvaccinated men was significantly associated with Asian ethnicity, off-campus residence, and history of a sexually transmitted disease other than HIV-1 or hepatitis B and inversely associated with recent non-intravenous drug use. Eighteen percent of the participants reported having had sex with women during the previous 12 months, and 26.4% reported a history of unprotected anal intercourse during the previous six months. Men who reported unprotected anal intercourse were more likely to have at least one steady partner, to have met their partners in anonymous settings, and to be identified as probably alcohol dependent. CONCLUSIONS: Although the prevalence of HIV-1 infection among young homosexual and bisexual men in Boston was relatively low, the high rates of unprotected anal intercourse suggest a potential for future HIV-1 and hepatitis B transmission. Interventions should focus on young men with histories of sexually transmitted diseases, alcohol abuse, and depression.

Adolescent↗