Effects of muscle CHO-loading manipulations on hormonal responses during prolonged exercise

This study examined the effects of a pre-experimental period of muscle carbohydrate (CHO)-loading manipulations followed by a 24-h CHO-poor diet, intended to increase muscle glycogen content and reduce hepatic glycogen levels, on substrate and endocrine responses during a period of prolonged exercise. Seven subjects pedaled a cycle ergometer for 70 min at 64% leg VO2max (1) after normal CHO intake (CHON) and (2) after leg muscle CHO loading (CHOL), both of these procedures being followed by a period of arm exercise (70 min; 70% arm VO2max) and 24 h CHO-poor intake. CHON, as compared to CHOL condition, resulted in greater blood concentrations of free fatty acids (1.8 vs 1.3 mmol X L-1), glycerol (0.41 vs 0.28 mmol X L-1), norepinephrine (2.2 vs 1.5 ng X ml-1), epinephrine (0.90 vs 0.27 ng X ml-1), and cortisol (47 vs 23 g X dl-1) at min 70 of exercise. Insulin concentrations during exercise showed a strong tendency to be lower in CHON than in CHOL condition, although the differences were not significant. There were no significant differences between the two conditions in blood glucose, lactate, and glucagon concentrations. These data indicate that muscle CHO-loading manipulations intended to specifically increase the muscle glycogen content are associated with the difference in metabolic adaptation and hormonal changes during exercise.     

Smoking cessation during pregnancy: strategies used by Michigan family physicians

This study reports the attitudes and strategies of members of the Michigan Academy of Family Physicians about their antismoking interventions for pregnant smokers. Of the 978 physicians surveyed, 607 (62 percent) returned completed questionnaires. Three hundred twenty-three (53 percent) were not practicing obstetrics. The remaining 284 physicians currently practicing obstetrics constituted the study group. Ninety-four percent of these physicians routinely assessed smoking status at the first prenatal visit. Ninety-eight percent advised pregnant smokers to quit smoking during pregnancy. The most frequently used method of intervention was personal counseling (97 percent), followed by referral to smoking cessation clinics (40 percent), and behavior modification (20 percent). Fifty-seven percent of the physicians reported using antismoking pamphlets, and 30 percent used antismoking posters designed for pregnant women. Only 11 percent of the physicians surveyed were generally satisfied with the effectiveness of their current methods. Nonetheless, 97 percent were convinced that the benefits of smoking cessation during pregnancy merited their efforts. The physicians in this sample consistently have advised their pregnant smokers to quit, but most believe there is a need for more effective smoking cessation methods.     

The entorhinal cortex: an examination of cyto- and myeloarchitectonic organization in humans

The entorhinal cortex (ERC) has been implicated in the pathophysiology of Alzheimer's disease, schizophrenia and other disorders affecting cognitive functions. While powerful anatomical and histochemical methods (immunohistochemistry, in situ hybridization, etc.) may be applied (although with limitations) to postmortem human brain, each analysis should utilize a cytoarchitectonic approach to provide appropriate comparisons within the subdivisions of the ERC. Accordingly, we describe here the normal cyto- and myeloarchitecture of the human ERC as a prerequisite for the accompanying study of this region in schizophrenia. Our parcellation of this cortex differs from previous treatments in three ways. First, we adopted specific criteria of inclusion to define each subdivision of the region. Although distinctive ERC features are most prominent in the intermediate portion of this region, at least one of these features was considered the minimum necessary criterion to include adjacent tissue in the entorhinal area. Second, we used morphometric measurements (neuronal size and density as well as subdivisional volume and laminar thickness) to support our qualitative evaluation. Third, we have applied to the human ERC the conventional cytoarchitectonic nomenclature of the entorhinal cortex used previously in studies of non-human primates. This allows a more accurate extrapolation of the available numerous experimental anatomical, physiological and psychological data on this region to the human. As in the monkey, the five main subareas were recognized in the human (prorhinal, lateral, intermediate, sulcal and medial) but three required further subdivision (intermediate, sulcal and medial). The morphometric results obtained suggested a progression of the human entorhinal cortex from the peripheral to the central subareas, with the intermediate subarea (281) as the most complete entorhinal subdivision. Compared with non-human primates, the human ERC not only retains the basic periallocortical organization but also demonstrates further evolution. Taken together with available experimental data on the connectivity of this brain region, these results provide an anatomical basis for evaluating the ERC in human behavior.      

Whither RDS? An investigation of Respondent Driven Sampling as a method of recruiting mainstream marijuana users

Background  

An important challenge in conducting social research of specific relevance to harm reduction programs is locating hidden populations of consumers of substances like cannabis who typically report few adverse or unwanted consequences of their use. Much of the deviant, pathologized perception of drug users is historically derived from, and empirically supported, by a research emphasis on gaining ready access to users in drug treatment or in prison populations with higher incidence of problems of dependence and misuse. Because they are less visible, responsible recreational users of illicit drugs have been more difficult to study.