Vertebroplasty increases trabecular microfractures in elderly female cadaver spines.

UNLABELLED: This study assessed whether vertebroplasty increases trabecular bone microfractures in adjacent vertebrae of elderly female cadavers. Results indicated microfractures were almost two times greater in superior adjacent vertebrae for vertebroplasty treated spines compared to non-treated controls. This finding may aid in developing improved treatments for osteoporotic women with vertebral fractures. INTRODUCTION: Although vertebroplasty may stabilize compression fractures and reduce pain, subsequent vertebral fractures occur in approximately 25 % of patients, reducing the overall safety of this procedure. This is particularly a concern in vertebrae surrounding the treated level where bone cement may cause abnormal transfer of forces to adjacent spinal structures. Therefore, the objective of this study was to quantify the effects of vertebroplasty on local trabecular bone damage in adjacent vertebrae. METHODS: Five level motion segments (T11-L3) from osteopenic/osteoporotic female cadaver spines (T-score -2.9 ± 1.0) were assigned into either vertebroplasty or control (no vertebroplasty) groups (n = 10/group) such that T-score, trabecular microarchitecture, and age were similar between groups. Compression fractures were created in the L 1 vertebra of all specimens and PMMA bone cement was injected into the fractured vertebra of vertebroplasty specimens. All spine segments were subjected to cyclic axial compression (685-1370 N) for 115,000 cycles. Post-testing, trabecular cubes were cut from adjacent (T12 and L2) vertebral bodies and histologically processed. Trabecular microfractures were identified and normalized by bone area in each section. RESULTS: There were significantly more trabecular microfractures (p < 0.001) in superior adjacent vertebral bodies of the vertebroplasty group (0.091 ± 0.025 microfractures/mm(2)) when compared to the control group (0.049 ± 0.018 microfractures/mm(2)). However, there was no difference in trabecular microfractures (p = 0.835) between vertebroplasty (0.045 ± 0.022 microfractures/mm(2)) and control groups (0.035 ± 0.013 microfractures/mm(2)) for inferior adjacent vertebral bodies. CONCLUSIONS: Vertebroplasty specifically impacts the superior adjacent vertebrae of elderly female spines resulting in almost two times more trabecular microfractures when compared to non-treated controls.

The traditional and emerging role of nuts in healthful diets.

Throughout history, nuts have been a staple food providing energy, protein, essential fatty acids, vitamins, and minerals. Today, nuts are classified as part of the USDA Food Guide Pyramid's Meat/ Meat Alternate Group. Foods in this group contribute protein as well as important vitamins and minerals to the diet. Nuts are also being studied for their potential health benefits. Research suggests that there may be a connection between frequent nut consumption and a reduced incidence of coronary heart disease. Thus, tradition and promising scientific evidence combine to support the role of nuts in healthful eating.

[Prevention of AIDS: experience with adolescents from a state elementary school in Porto Allegre]. / Prevenção da AIDS: experiência participativa com adolescentes de uma escolal estadual de 1. grau em Porto Alegre.

This article refers to a participating experience in AIDS prevention with teenagers from 5th to 8th grade of a state elementary school, through workshops. This working method uses participating technics to allow relaxation, discussion and theme reflection by the group. The results obtained with this work of information and health education indicate the possibility of stimulating preventive acting development through reflection on the health-disease process, which involves HIV virus infection and comprehension of the disease extension and gravity for public health.

Filter screening of antibody Fab fragments secreted from individual bacterial colonies: specific detection of antigen binding with a two-membrane system.

Recently antibody fragments have been expressed in a functional form from bacteria. We have devised a simple method to detect the binding of antigen to antibody Fab fragments secreted by bacterial colonies. Bacteria harboring plasmid vectors that direct the secretion of Fab fragments into the bacterial periplasm are grown on one membrane. The secreted fragments are allowed to diffuse to a second "capture" membrane coated with anti-globulin, and are probed with antigen. Using enzyme or colloidal gold conjugates, the binding of antigen is detected on the second membrane as a colored spot. The colonies can be regrown on the first membrane, and the antigen binding signal on the second membrane is free of noise contributed by bacterial debris.

Colony assays for antibody fragments expressed in bacteria.

This paper describes procedures for the detection and selection of bacterial colonies expressing antibody fragments of desired antigen specificity. Fab and Fv fragments are detected in a filter assay in which bacterial colonies are grown on a master filter in contract with a second, antigen-coated filter. Ab fragments diffusing onto the second filter bind antigen directly and specifically and are detected with a monoclonal antibody directed against a myc-tag sequence fused to the carboxy-terminal end of the light chain or heavy chain (direct assay). Single-chain Fv (scFv) in which the VH and V1 sequences are joined by a short linker peptide are detected by a modified procedure in which scFv are immobilized on filters coated with the anti-myc-tag sequence and subsequently detected by specific binding to radiolabeled antigen (indirect assay). A single positive bacterial colony expressing antigen-specific Fv (or scFv) can be recovered among at least 10,000 negative colonies using the procedures described. The direct assay has been successfully used to discriminate Fv fragments which express point mutations known to increase the binding affinity of antibodies to the hapten 2-phenyl-oxazolone. The procedures described may thus prove generally useful for the selection of antigen-specific clones expressed in bacteria and/or higher-affinity variants of such antibodies.

Down-regulation of phorbol diester binding to NG115-401L neuronal cells is dependent on structure, concentration and time.

The down-regulation of [3H]PDBu binding to a neural cell line, NG115-401L, has been examined in response to two biologically active phorbol diesters, PDBu and PMA. Chronic treatment with PDBu or PMA causes a concentration- and time-dependent loss of specific [3H]PDBu binding. The action of PMA is biphasic with respect to both concentration and time dependence.

Starch digestibility of foods: a nutritional perspective.

Dietary starch varies greatly in digestibility and its effects on the utilization of other nutrients. The variation appears to be due to differences in starch components and their crystallinity. Processing treatments, storage conditions, chemical modification, and genetic breeding influence the digestibility of starch. Cereal starches are generally more digestible than root/tuber and legume starches. Although cooking often significantly improves the digestibility of poor and intermediately digestible starches, some foods such as bananas with starches of these types are consumed uncooked. The efficient digestion of starch is especially important to specific groups of people such as infants under 6 months of age. Ruminants must also be provided with highly digestible starch to assure maximum production efficiency. Poor digestibility of starch may have negative effects on the utilization of protein and minerals but is likely to have positive effects on the availability of certain vitamins. Decreases in the rate of starch digestion may have therapeutic application. Most clinical studies have reported that starch blockers do not elicit a significant decrease in the digestion of starch in humans. Much remains to be learned, clarified, and understood about starch digestion and its effects on diabetes and weight control.