Effect of clozapine on the oxygen, glucose uptake and oxidative phosphorylation of rat brain in vitro

Clozapine, a neuroleptic drug isostere of the phenothiazines, at a dose of 10(-3) M decreased the oxygen consumption of rat brain slices and homogenates. However, this effect was not potentiated when brain slices were incubated with 100 mM potassium or in a calcium-free medium, the uncoupling of brain mitochondrial oxidative phosphorylation by 10(-3) M clozapine can also be rulled out.     

Lack of effect on ovariectomy on the metabolism of vitamin D and intestinal calcium-binding protein in female rats

A 20-year-old woman lost all useful vision over a 2 1/2-month period as a result of a necrotizing and occlusive vasculitis of the retina. Treatment with prednisone, immunosuppressants, and aspirin was unsuccessful. No systemic manifestations of the disease were found and no cause was discovered. Kodachromes and fluorescein angiograms showed the progression in one eye from normal to near total retinal necrosis. The process began with a mild venous dilation and peripheral arteritis that progressed into an obliterative vasculitis with abrupt vessel dilation, hemorrhages, and retinal swelling. This was followed by necrosis and sloughing of the retina into the vitreous. Vitreous contraction and necrotic retina produced unrepairable retinal detachments.     

Are perinatal risk factors helpful in predicting and optimizing treatment strategies for transient hypothyroxinemia in very-low-birth-weight infants?

Transient hypothyroxinemia is common in premature infants and has been associated with intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), poor neurodevelopmental outcomes, and mortality. Recent trials have failed to show that supplemental thyroid hormone improves overall neurodevelopmental outcome. The objective of this article is too determine perinatal risk factors for transient hypothyroxinemia (TH). We studied a cohort of infants born between July 1993 and July 2000 who were less than 1500 g and who received a newborn screening for thyroid function ( n = 932). Total serum thyroxine (T(4)) was collected routinely on the fifth day of life. T (4) was correlated with gestational age (R = 0.59, p < 0.01). After controlling for potential confounding variables, gestational age, dopamine, and mechanical ventilation were found to be independently associated with low T (4) (overall model: r(2) = 0.41, p < 0.01). Number needed to treat (NNT) analysis showed treating all infants less than 27 weeks would lead to treating 6.3 infants for every one with a subsequent T(4) < 5 microg/dL. By combining gestational age and need for dopamine support, NNT = 2.4 for every one infant with subsequent T(4) < 5 microg/dL. Low gestational age, mechanical ventilation, and need for dopamine were associated with low T(4) levels and may be helpful in optimizing treatment strategies for TH.     

Graphitization effects of CH4 addition on NCD growth by first and second Raman spectra and by X-ray diffraction measurements

Nanocrystalline diamond (NCD) films were grown on silicon substrates by hot filament chemical vapour deposition in Ar/H₂/CH₄ gas mixtures. In the current study, the methane volume concentration varied from 0.5 to 3.5 vol.% in order to estimate its effect on nanodiamond morphology and structure. Film micrograph obtained from scanning electron microscopy showed diamond grain agglomerate, also called ballas diamond, which presented the grain size variation as a function of methane concentration increase. The transition from diamond agglomerate to graphite structure was also observed when CH₄ concentration is higher than 2.0 vol.%, confirmed from second order Raman measurements. The film local stress was estimated from the G-peak shift analyses and showed critical values necessary for the graphite/diamond phase formation. Structural investigations carried out by X-ray diffraction measurements for films deposited from 0.5 up to 2.0 vol.% CH₄ presented characteristic diamond diffraction peaks corresponding to 〈111〉, 〈220〉 and 〈311〉. A preferential orientation, changed from 〈110〉 to 〈111〉, was observed during NCD film deposition as a function of the methane concentration.     

What is a specialist? The role of board certification in occupational medicine

A shortage of occupational medicine physicians exists for which a number of solutions have been proposed. The lack of board-certified specialists to address the increasingly complex issues encountered in this area of medicine has contributed to a credibility and identity crisis within the occupational medicine community. This article will review the significance of board certification and its importance for enhancing and preserving the specialty of occupational medicine.     

Detection of apoptosis in human and rat ovarian follicles

OBJECTIVE: The purpose of this study was to determine whether cells acquired from individual human preovulatory follicles undergo apoptosis (physiologic cell death) and, if so, to correlate the degree of apoptosis with characteristics of the follicles or the oocytes derived from the follicles. METHODS: We devised a sensitive nonradioactive method for detecting apoptotic DNA fragmentation in small numbers of cells derived from rat atretic follicles and follicular aspirates of patients undergoing assisted reproductive technologies. RESULTS: Using this method, apoptotic DNA was detected in rat atretic follicles, with optimal detection at 10-100 ng. Furthermore, apoptotic DNA was detected in some, but not all individual human follicular aspirates from several patients, and was found in follicles that produced oocytes that fertilized and developed into embryos. CONCLUSION: Apoptosis occurs in cells from human ovarian preovulatory follicles and may be a normal physiologic process of the follicle during luteinization.