Humeral skeletal development and plasma constituent changes in fetuses of ewes maintained on a low calcium diet from 60 days of gestation

Summary The objective of this study was to evaluate the effects of a long-term, low-calcium diet on fetal calcium metabolism and fetal skeleton skeleton development in ewes. Eleven pregnant sheep were assigned to two groups, fed either a diet low in calcium (0.26% total dry matter) or normal in calcium (0.8% total dry matter) for 2 months, starting at 60 days gestational age. The ewes fed the low calcium diet showed lower plasma levels of calcium and higher plasma levels of hydroxyproline, parathyroid hormone, and 1,25 (OH)₂D compared with the ewes fed the normal calcium diet. There were no differences in these variables between the two groups of fetuses. These observations suggest that the plasma components of calcium homeostasis measured in the fetal lamb in the present study are independent of the ewe and are not significantly affected by the presence of lowere maternal calcium for many weeks during pregnancy. Despite the ability of the fetus of the ewe on the low calcium diet to maintain relatively normal circulating plasma components of calcium homeostasis, long-term maternal hypocalcemia delayed fetal skeletal ossification as shown by histological examination of the fetal humerus. The fetal humerus from low calcium-fed ewes showed a lower proportion of bone versus cartilage (45.6±5.9 versus 57.4±4.6%, mean ±SD) lower ash content (15.4±1.5 versus 17.4±1.0%), and lower specific gravity (1.19±0.2 versus 1.22±0.02) (P<0.05) than the humerus from fetuses of normal calcium-fed ewes. This study shows that the long-term calcium intake of the ewe does affect fetal skeletal development, despite a lack of observable effects on fetal plasma concentrations of calcium or known calcium regulating hormones such as 1,25(OH)₂D or parathyroid hormone.     

Clonidine pretreatment modifies the growth hormone secretory pattern induced by shortterm continuous GRF infusion in normal man

OBJECTIVE: The aim of this study was to investigate the effect of a single dose of clonidine on the pattern of GH release in response to a 10-hour continuous GRF infusion in normal man. DESIGN: Plasma GH was analysed in samples withdrawn at 20-minute intervals, from 0900 to 1900 h, according to the following protocols: in a control study, a placebo was given at 1000 h; in other experiments, clonidine (300 micrograms, orally) was given at 1000 h, alone or together with a continuous intravenous infusion of GRF 1-29 (0.3 micrograms/kg/h) starting at this time. In another experiment, the continuous infusion of GRF 1-29 was preceded by placebo administration at 1000 h. PATIENTS: Eight normal volunteers (four women and four men), aged 19-24 years were studied. MEASUREMENTS: Plasma GH levels were measured by RIA. Analysis of the pattern of GH secretion was performed using cluster analysis. RESULTS: Clonidine induced a slight but significant increase in plasma GH values, peaking 60 to 120 minutes later; however, no significant changes were observed in indices of total and pulsatile GH release for the whole sampling period in this study. Continuous GRF administration led to increased episodic GH secretion, by augmenting GH peak amplitude, although peak frequency was not modified. An increase in interpulse GH values was also observed during GRF infusion. Pretreatment with clonidine clearly changed the pattern of GH release during GRF infusion: the amount of GH secreted was significantly higher, the number of GH peaks significantly increased, and almost all the GH was secreted within them. CONCLUSIONS: These data concord with our previous demonstration that clonidine disrupts the hypothalamic-somatotroph rhythm by inhibiting the hypothalamic release of somatostatin. Given that clonidine pretreatment induced a more physiological episodic pattern of GRF-induced GH release, the possibility of combining clonidine and GRF therapy for short stature in children is envisaged.     

Do weekly and fast-rotating shiftwork schedules differentially affect duration and quality of sleep?

 Characteristics of shiftwork schedules can have distinct impacts on workers’ sleep. This report presents comparisons of the effects of two different shiftwork schedules on duration and quality of the main sleep episodes in comparable worker populations at two different petrochemical plants. No significant differences were found for sleep duration in comparing the two plants. However, within each plant’s shift cycles, morning and night shifts showed shorter sleep durations than all other workdays and days off. Quality of sleep was perceived as lowest for night shifts of both plant schedules, and of lesser quality for weekly than for fast-rotating shifts. These results support recommendations for reducing the number of consecutive nights of shiftwork. However, before recommending any optimal shift schedule, interactions of sleep duration and quality with shift schedules need much further evaluation. Received: 18 December 1995/Accepted: 18 July 1996     

An open-label efficacy pilot study with pimecrolimus cream 1% in adults with facial seborrhoeic dermatitis infected with HIV

BACKGROUND: Seborrhoeic dermatitis (SD) is a common dermatosis in human immunodeficiency virus (HIV)-positive patients, many of whom do not respond satisfactorily to conventional topical treatments such as corticosteroids and antifungals. OBJECTIVE: A pilot study to investigate the efficacy and tolerability of pimecrolimus cream 1% in HIV-positive patients with facial SD. METHODS: In a single-centre study, 21 HIV-infected patients with mild to severe SD were treated twice daily with pimecrolimus cream 1% for 14 days. Thereafter, treatment was discontinued and patients followed up for 5 weeks. Skin involvement at baseline and on days 7, 14, 21, 35 and 49 was assessed using a four-point clinical score and digital photography. MAIN OUTCOME MEASURES: Efficacy and safety of pimecrolimus cream 1% treatment and incidence of relapse in the follow-up phase. Results Marked improvement was seen in clinical parameters at day 7, with >or= 90% patients clear of symptoms at day 14. Relapse was observed at day 35 but signs were milder than at baseline. All patients responded to therapy, despite their immunological status. Pimecrolimus did not alter CD4(+) and CD8(+) T-cell counts or viral load during the treatment period. CONCLUSION: Pimecrolimus cream represents a new, effective therapeutic option for facial SD in HIV patients.     

Sub-acute intoxication by Senna occidentalis seeds in rats.

Senna occidentalis (So) is a weed that grows in pastures along fences and in fields cultivated with cereals such as corn and soybean, and many reports have been showing intoxication with this plant in different animal species. It is also used in many medicinal purposes. The objective of the present study was to better evaluate the toxic effects of prolonged administration of So seeds to rats. Forty male Wistar rats were divided into four groups of 10 animals each, three of them respectively fed rations containing 1%, 2% and 4% So seeds, and the last one (control) fed commercial ration for a period of 2 weeks. Fourteen rats were also used in a pair-feeding (PF) experiment. The rats of the experimental groups showed lethargy, weakness, recumbency, depression and emaciation. Two rats of the 4% group and two of the PF group died during the experiment. Histopathological study showed fiber degenerations in the skeletal (Tibial, pectoral and diaphragm) and cardiac muscles. In the liver parenchyma, was observed vacuolar degeneration and, in the kidney, mild nefrosis in the proximal convoluted tubules. All of these alterations occurred in a dose-dependent fashion. Moderate to severe degeneration and spongiosis in the central nervous system, especially in cerebellum. Electron microscopy revealed mitochondrial lesions in all analyzed tissues.     

Comparative cytotoxicity of 2,3,9-trimethoxypterocarpan in leukemia cell lines (HL-60, Jurkat,Molt-4, and K562) and human peripheral blood mononuclear cells

The purpose of this study was to investigate the antiproliferative activity of 2,3,9-trimethoxypterocarpan, a known pterocarpan with cytotoxic activity against many tumor cell lines, in a panel of four leukemia cell lines (HL-60, Molt-4, Jurkat, and K562) and on human peripheral blood mononuclear cells (PBMC). The pterocarpan showed IC₅₀ ranging from 0.1 to 0.5 μg/ml at leukemic cells after 72 h of incubation, with K562 being the most resistant cell line. This compound seemed to be selective to tumor cell lines, since at a concentration of 10 μg/ml after 72 h, it only reduced 19% of viable peripheral mononuclear cells.     

Differential effect of taurine and serotonin on the outgrowth from explants or isolated cells of the retina

The sulfur amino acid taurine and the indoleamine serotonin increases and decreases, respectively, the outgrowth from goldfish retinal explants. Taurine seems to be acting, at least partially, through an increase in calcium fluxes, and the serotonin-inhibiting effect appears to be mediated by serotonin_1A receptors and cAMP. Isolated cells of postcrush goldfish retina and of retina from 5-day-old rats were cultured in the presence of taurine or serotonin. In the goldfish, the classical morphology of postcrush ganglion cells was observed. An antibody against the glycoprotein Thy-1 labelled three types of cells in the cultures of goldfish retina. The number of cells outgrowing and the length of the main neurite was measured at 5 days in culture in both species. The number of cells presenting neurites was increased in the goldfish retina by the addition of taurine, and decreased by serotonin. However, the length of the neurites was unaffected by the addition of the modulators. In the rat, only a slight decrease in the number of cells outgrowing was observed in the presence of serotonin. The incorporation of [³H]thymidinewas not modified after 5 days in culture in the presence of taurine or serotonin, either in the goldfish or in the rat retina. The antibody Thy 1.1 can label retinal cells of the goldfish invitro, one of them being ganglion cells. The trophic effect exerted by taurine in the postcrush goldfish retina needs the integrity of the tissue favoring the interaction of cells and factors, because outgrowth increases in retinal explants, but not in isolated cells.     

Concurrent medical and psychiatric disorders among schizophrenic and neurotic outpatients

The records of two groups of patients (358 schizophrenics and 69 neurotics), attending the community mental health center of the Johns Hopkins Hospital, were reviewed to assess the extent and severity of reported medical problems. Results indicate that 38% of the schizophrenics and 53% of the neurotics report medical problems, but schizophrenics present with serious medical problems more often than do the neurotics. The authors draw attention to the need for properly assessing the severity of these medial problems and for adequately coordinating psychiatric and medical care. Strategies to overcome these difficulties are suggested.