Search PubMed⌕ Search

Biomedical subjects

J Weinberg

Publications and source records attributed to J Weinberg.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Nutritional issues in perinatal alcohol exposure.

Animal models are important in perinatal alcohol research because they provide an opportunity to study the effects of alcohol while controlling for biological, social and environmental factors which are difficult to control in human studies. One of the variables which has often been overlooked in animal studies, however, is nutrition. Even when there has been an awareness of the need for nutritional controls, such controls have been particularly difficult to implement because alcohol and nutrition interact at so many levels. In this review the interactions of alcohol and nutrition are discussed and some of the methods used to separate effects of alcohol from effects of alcohol-induced malnutrition are considered. In particular, the issues of method of alcohol administration as well as effects of alcohol on nutrient intake, nutrient digestion, absorption and utilization, and nutrient requirements are reviewed. Potentiation of ethanol effects by dietary deficiencies during pregnancy, and possible synergistic effects of alcohol and nutritional deficiencies are described. Finally, the problems inherent in pair-feeding and ad lib feeding control procedures, as well as the issues of diet composition and feeding schedule are discussed.

Alcoholism↗
PubMedDate not supplied

Neuromotor development and response inhibition following prenatal ethanol exposure.

Pregnant rats were given liquid diet with ethanol ad lib, liquid control diet pair-fed to Group 1, or pelleted control diet ad lib. No differences were found in offspring birth weight or rate of growth over 5 postnatal weeks. Upper and lower incisors erupted earlier and palmar grasp disappeared earlier in pair-fed and alcohol animals, while all groups were alike in eye opening, ear unfolding, negative geotaxis, auditory startle, surface righting, cliff avoidance, free-fall righting and mesh climbing. However, ethanol exposed animals showed deficits in orienting ability at 2-7 days of age and in response inhibition in a punished step-down task at 35 days of age. Furthermore, preweaning handling eliminated the deficit in response inhibition. Taken together, these data indicate that without the confounding variable of undernutrition, prenatal ethanol exposure may differentially affects the development of systems involving sensory perception, motivation or inhibition, while systems involving physical, reflex, and locomotor development remain unaltered.

Animals↗
PubMedDate not supplied

Prenatal ethanol exposure: pituitary-adrenal activity in pregnant dams and offspring.

Pregnant Sprague-Dawley females were assigned to one of three treatments: liquid diet with ethanol (5.5% w/v), ad lib; liquid control diet, pair-fed to alcohol group; pelleted control diet, ad lib. On day 19 of gestation females consuming ethanol exhibited greater corticoid elevations than controls at 30 min following stress. Pair-fed females were similar to controls at 30 min, but did not exhibit the return toward basal levels shown by both ethanol and control females at 90 min following stress. Thus ethanol consumption during pregnancy produced an enhanced stress response, while pair-feeding during pregnancy produced prolonged corticoid activation following stress. In offspring tested at 39 days of age, no sex differences occurred in the plasma corticoid stress response of nonhandled animals from any of the 3 diet groups. However in handled animals, it was observed that females prenatally exposed to ethanol exhibited higher corticosterone levels than alcohol-exposed males. Thus prenatal dietary treatment appeared to interact with postnatal handling experience to influence the development of the pituitary-adrenal system.

Animals↗
PubMedDate not supplied

Hospitals and plastics. Dioxin prevention and medical waste incinerators.

CHLORINATED DIOXINS and related compounds are extremely potent toxic substances, producing effects in humans and animals at extremely low doses. Because these compounds are persistent in the environment and accumulate in the food chain, they are now distributed globally, and every member of the human population is exposed to them, primarily through the food supply and mothers' milk. An emerging body of information suggests that dioxin contamination has reached a level that may pose a large-scale, long-term public health risk. Of particular concern are dioxin's effects on reproduction, development, immune system function, and carcinogenesis. Medical waste incineration is a major source of dioxins. Polyvinyl chloride (PVC) plastic, as the dominant source of organically bound chlorine in the medical waste stream, is the primary cause of "iatrogenic" dioxin produced by the incineration of medical wastes. Health professionals have a responsibility to work to reduce dioxin exposure from medical sources. Health care institutions should implement policies to reduce the use of PVC plastics, thus achieving major reductions in medically related dioxin formation.

Bioethics↗
PubMedDate not supplied

Evaluation of diaphragm electromyogram contamination during progressive inspiratory maneuvers in humans.

The diaphragm electromyogram (EMGdi) is susceptible to contamination by non-diaphragm related electrical signals such as the ECG, electrode motion artifacts, and other sources of noise. It is difficult to distinguish between these contaminating signals and those that are representative of the non-contaminated EMGdi, especially during periods when the EMGdi amplitude is relatively small, as during mild contractions of the diaphragm. The aim of the present study was to evaluate how contaminating signals influence the EMGdi power spectrum center frequency (CF) during progressive inspiratory maneuvers. EMGdi and transdiaphragmatic pressure (Pdi) were measured via an esophageal electrode in eight patients with cervical cord injury performing inspiratory capacity (IC) maneuvers. The influence of the contaminating sources on CF was evaluated by two spectral deformation indices, one which is sensitive to both high and low frequency spectral deformation (omega index), and the other which is sensitive to high frequency deformation only (CF1000/CF500 index). The results indicated that EMGdi CF values scattered over a wide frequency range, particularly when the signals were obtained at Pdi levels less than 15% of Pdimax, or at lung volumes less than 30% of IC. When the spectral deformation indices were applied, the scattering in CF values was drastically reduced. This was expressed by a factor of 4 reduction in the coefficient of variation of the CF values. The majority of the excluded EMGdi signals (i.e. not satisfying the spectral deformation index inclusion levels), had low CF values mainly due to the presence of electrode motion artifacts. It was concluded that: 1) The majority of EMGdi power spectrums are deformed early on during unloaded inspirations, and their CF values should be carefully interpreted as being representative of diaphragm function. 2) The relative contribution of contaminating signals in the EMGdi decreases proportionally throughout the first two thirds of an inspiration to IC. 3) The use of visual inspection of the signal in the time domain is questionable as a method to discriminate non-contaminated signals. 4) Analysis of the signal in the frequency domain makes it possible to detect the influence of signal contamination.

Adult↗