Biomedical subjects

W A Sands

Publications and source records attributed to W A Sands.

7 recordsLinked to original sources

PubMed1996

Is the induction of apoptosis the mechanism of the protective effects of TNF alpha in helminth infection?

Tumour necrosis factor alpha has been implicated in protective immune responses to a number of parasitic helminths. However, the final effector mechanisms resulting in death or expulsion of the parasite are unclear. Here we suggest that, by employing phylogenetically conserved mechanisms, the mammalian immune system is able to interfere with helminth development directly and that the protective effects of TNF alpha in helminth infections may operate via the induction of parasite apoptosis.

Animals↗

PubMed1995

A comparison of subtalar joint maximal eversion while jogging on the minitrampoline and floor.

The jogging minitrampoline is a common tool for exercise and rehabilitation that is lauded as helpful in reducing lower extremity stresses. The deformable bed of the minitrampoline may result in altered jogging mechanics of the subtalar joint, potentially leading to uncharacteristic mechanics of the lower extremity. The purpose of this study was to examine eversion of the subtalar joint in subjects jogging on the minitrampoline vs. a wooden floor surface. Subjects were instrumented with a flexible electrogoniometer (elgon) taped from the heel to the gastrocnemius along the Achilles tendon. The elgon was interfaced to a personal computer. Data were examined for the average maximal eversion values of five steps during jogging in two experiments. Results of the first experiment (N = 27) indicated significantly greater mean maximal eversion angles while jogging on the minitrampoline than on the floor. The second experiment involved 10 male and 10 female subjects jogging for 20 minutes with a counterbalanced sequence of jogging conditions, alternating between the floor and the minitrampoline. The second experiment indicated that maximal eversion angles were significantly greater on the minitrampoline than on the floor and increasing jogging time resulted in greater eversion angles and a significant interaction between jogging condition and time. Results suggest that people who should avoid valgus deviations to the lower leg should not jog on the jogging minitrampoline.

Adult↗

PubMed1994

The role of a phosphatidylcholine-specific phospholipase C in the production of diacylglycerol for nitric oxide synthesis in macrophages activated by IFN-gamma and LPS.

Murine macrophages activated by interferon (IFN)-gamma and bacterial lipopolysaccharide (LPS) produce large amounts of nitric oxide (NO), which is a critical mediator for a variety of biological functions. The expression of this inducible NO synthase (iNOS) involves a protein kinase C (PKC)-dependent pathway, but the mechanism for the PKC activation in this system is unclear. Through analysis of diacylglycerol (DAG) synthesis and choline metabolism in activated macrophages, direct evidence is provided that NO synthesis involves the activation of an unusual phosphatidylcholine-specific phospholipase C (PC-PLC) and not a phosphatidylinositol-specific phospholipase C (PI-PLC) or phospholipase D (PLD).

Amino Acid Oxidoreductases↗

PubMed1994

Inhibition of nitric oxide synthesis by interleukin-4 may involve inhibiting the activation of protein kinase C epsilon.

The murine macrophage cell line, J774, when activated with interferon-gamma (IFN-gamma), expressed high level of inducible nitric oxide synthase (iNOS) and bound significantly more [3H]-phorbol-dibutyrate (PBu2) compared to non-activated cells. The increased PBu2 binding to the particulate fraction of the cells is a measure of activation and translocation of protein kinase C (PKC). Both the expression of iNOS and the enhanced. PBU2 binding in the activated J774 cells were significantly inhibited by the pretreatment of the cells with murine recombinant interleukin-4 (IL-4). Stimulation of J774 cells by IFN-gamma and lipopolysaccharide results in the translocation predominantly of the epsilon isoform of PKC (PKC-epsilon), and this is inhibited by IL-4. The inhibition of PKC activation was also evident by measuring the PKC activity in the cytosolic-fraction of the IL-4-treated cells. Activated J774 cells pretreated with IL-4 or a PKC-specific inhibitor (RO31-8220) failed to express mRNA of iNOS analyzed by PCR. These results, therefore, suggest that the inhibition of nitric oxide synthesis in activated murine macrophages by IL-4 is at the transcriptional level and may involve the inhibition of the activation of PKC-epsilon.

Amino Acid Oxidoreductases↗

PubMed1994

Kinesiological motion expert system.

Kinesiology builds on anatomical information by establishing which muscles contribute to human motion and to what extent. This 'body as machine' approach seeks to identify particular muscles as contractile 'engines'. The learning of muscular contributions to human motions based on long tables of origins, insertions, innervations, and actions is tedious and often incomplete based on author judgments of which muscles and motions to include. The kinesiological motion expert system (KMES) was developed so that students could easily select joints, actions, and tension types and receive computerized output listing the muscles that could contribute to the motion requested. In addition, a student can select a particular muscle and tension type and the program will return all of the motions that the selected muscle might contribute. The KMES was written in PDC Prolog and has a knowledge base of 1583 movements. Implementation of the KMES in kinesiology classes resulted in an increase in average student final scores of approximately 15% (F(3,190) = 12.11, P < 0.0001).

Anatomy↗

PubMed1992

Changes in the lateral diffusion of fluorescent lipid analogues in the surface membrane of adult male Schistosoma mansoni.

The effect of serotonin on the fluidity of the tegumental membranes of adult male Schistosoma mansoni was assessed by the fluorescence recovery after photobleaching technique. It was demonstrated that the translational diffusion of 5-N'-octadecanoyl aminofluorescein is reduced by a mechanism involving G-protein coupled activation of adenylate cyclase and lowering of intracellular calcium concentration. Furthermore, the lateral diffusion coefficient and the mobile fraction appear to be controlled by calcium and cAMP dependent pathways respectively. No change in the diffusion of the fluorescent phospholipid N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-phosphatidyl choline was observed, suggesting the two probes used here partition into two different domains that are under independent control. An increase in the amount of protein associating with a membrane cytoskeleton is also demonstrated.

Animals↗

PubMedDate not supplied

Women's gymnastics injuries. A 5-year study.

A 5-year prospective study on the time course of women's gymnastics injuries was conducted on a successful NCAA Division I team. Gymnasts recorded injuries on a computer terminal or via computer dot sheets immediately before each training session, including the injured body part, the event or activity, and the date of the injury. The definition of injury was "any damaged body part that would interfere with training." Athletes recorded injuries on the 1st day of onset and subsequently until the injury was healed. The initial onset of injury was considered a new injury. Subsequent records of the injury were considered continuing injury. Thirty-seven athletes participated through five collegiate seasons. They accounted for 5602 total training exposures with an average of 151.4 exposures per athlete. The analyses showed that gymnasts trained with an injury approximately 71% of the exposures, and a new injury could be expected from a gymnast during approximately 9% of the exposures. The largest number of injuries were of the repetitive stress syndrome type. The time series information showed that total injuries tended to increase until the middle of the competitive season, while new injuries showed prominent increases during specific training periods and during competition preparation and performance.

Adult↗