Ultrasensitive detection of unstained proteins in acrylamide gels by native UV fluorescence

Visualization of proteins inside acrylamide and other gels usually relies on different staining methods. To omit the protein-staining procedure, we visualized unstained proteins inside acrylamide gels by laser excitation with ultraviolet (UV) light (280 nm, 35 mJ/cm2) and directly detected native UV fluorescence. In one-dimensional gels, a detection limit as low as 1 ng for bovine serum albumin and 5 ng for other proteins with a linear dynamic range (2.7 orders of magnitude) comparable to state of the art fluorescent dyes could be achieved. In addition, the application of this method to 20 microg of a whole cell lysate separated in a two-dimensional gel showed more than 600 spots. Since protein labeling always represents a serious obstacle in protein identification technologies, the working efficiency with our procedure can be considered as a significant improvement for protein visualization and reproducibility in proteomics.     

Highlights of the Fourteenth Annual Summer Meeting of the American Orthopaedic Foot and Ankle Society, Boston, Massachusetts, July 24-26, 1998

Immunohistochemical-labeling for the neurochemicals gamma-aminobutyric acid (GABA) and enkephalin are abundant in the ventromedial nucleus of the hypothalamus (VMN). In VMN, both GABA and enkephalin may function to regulate feeding behavior, as well as other hormone-controlled behaviors. Importantly, in several brain areas, enkephalin is often thought to modulate GABAergic neurotransmission. Therefore, we used dual-labeling immunohistochemistry with electron microscopic analysis to study the circuitry of neurons containing GABA- and/or enkephalin-labeling within the VMN. Somato-dendritic profiles containing GABA-labeling were three fold more abundant than GABA-labeled axon terminals (117 soma or dendrites vs. 34 axons). In addition, axon terminals containing GABA-labeling sometimes synapsed onto GABA-labeled somata or dendrites (25% or 9/34). In contrast, under these conditions labeling for enkephalin was primarily restricted to axon terminals, which were very abundant throughout VMN. Enkephalin-containing terminals accounted for a large fraction (25% 23/92) of the axons in contact with GABA-labeled dendrites, although they also contacted unlabeled dendrites. These observations suggest that a population of VMN neurons are GABAergic. These may be either local circuit 'interneurons' or projection neurons. In addition, GABA-labeled VMN neurons may be regulated by either enkephalin or GABA. These morphologic observations provide the basis for disinhibitory mechanisms to function within the VMN.     

Macrolevel approaches to improve the availability of complementary foods

Large numbers of infants and young children suffer from the short- and long-term health effects of poor breastfeeding and complementary feeding practices. Strategies to improve the availability of and access to low-cost fortified complementary foods can play an important corresponding role to that of behavior change in improving nutritional status of young children. However, the nutritional quality of complementary foods used in publicly funded programs is not always optimal, and such programs are costly and reach only a tiny fraction of those who could benefit. To broadly reach the target population, such foods need to be commercially available at affordable prices and promoted in a way that generates demand for their purchase. A sensible long-term policy for the promotion of low-cost fortified complementary foods calls for attention to their nutritional formulations and cost, the economics of production, and the legislative, regulatory, and competitive framework in which marketing occurs. This paper provides information on how to improve the nutritional formulations of fortified complementary foods and outlines the necessary conditions for a market approach to their production and promotion.     

Interaction of dietary intake and diarrheal disease in child growth

There is evidence in the literature of the negative effects of diarrheal disease, and of the positive effects caused by food supplementation in postnatal growth. The present study analyzes the nature of the relationship between the effects of diarrheal disease and food supplementation on the growth of children of a rural area of Guatemala. The data analyzed were collected in a longitudinal study on food supplementation carried out by INCAP during the period comprised between 1969 and 1977. An important negative effect of diarrheal disease on growth was found on children three to 36 months of age with low dietary intake. Nevertheless, it was found that the negative effect of diarrheal disease on growth was lower in children whose dietary intake had important increments. In contrast, as compared with a study carried out in Colombia, where the supplementary feeding effect was restricted to groups with higher incidence of diarrhea, the supplementation effect on growth of Guatemalan children was found to be present at all levels of prevalence of diarrheal diseases. This article discusses the possible causes of the different results found in the Colombian study, as compared with those derived from the present study.     

Environmental Policy Analysis, Peer Reviewed: UV-B Screening by Tropospheric Ozone: Implications for the National Ambient Air Quality Standard

Air Quality.     

Thromboembolism after foot and ankle surgery. A multicenter study

Thromboembolic disease presents a potentially fatal complication to patients undergoing orthopaedic surgery. Although the incidence after hip and knee surgery has been studied and documented, its incidence after surgery of the foot and ankle is unknown. For this reason, a prospective multicenter study was undertaken to identify patients with clinically evident thromboembolic disease to evaluate potential risk factors. Two thousand seven hundred thirty-three patients were evaluated for preoperative risk factors and postoperative thromboembolic events. There were six clinically significant thromboembolic events, including four nonfatal pulmonary emboli, after foot and ankle surgery. The incidence of deep vein thrombosis was six of 2733 (0.22%) and that of nonfatal pulmonary emboli was four of 2733 (0.15%). Factors found to correlate with an increased incidence of deep vein thrombosis were nonweightbearing status and immobilization after surgery. On the basis of these results, routine prophylaxis for thromboembolic disease after foot and ankle surgery probably is not warranted.     

Numerical solution of the 2D-neutron diffusion equations of a non-rectangular computational area with the wave digital concept

In this paper, the neutron diffusion equations in two energy groups are dealt with. The underlying parabolic differential equations are “hyperbolised”, and solved using the wave digital concept. In contrast to other simulations using the wave digital concept, the computational area is not rectangular.