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Biomedical subjects

J Wallace

Publications and source records attributed to J Wallace.

At least 19 recordsLinked to original sources
PubMed1992

Modulation of leukocyte adhesion in rat mesenteric venules by aspirin and salicylate.

Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and number of adherent and emigrated leukocytes were measured in postcapillary venules both before and during superfusion of rat mesentery with either aspirin or sodium salicylate. In some experiments, animals were treated with either a leukotriene (LT)-synthesis inhibitor (L-663,536), an LTD4 antagonist (MK-571), an LTB4 antagonist (SC-41930), misoprostol, or prostaglandin (PG) I2, then the aspirin protocol was repeated. Superfusion of aspirin but not sodium salicylate resulted in increased leukocyte adherence and a reduced leukocyte rolling velocity but did not affect leukocyte emigration. Aspirin-induced leukocyte adhesion was effectively prevented by the LT-synthesis inhibitor and LTB4 antagonist but not by the LTD4 antagonist. Misoprostol and PGI2 also prevented the aspirin-induced adhesion responses. Superfusion of the mesentery with either platelet-activating factor (PAF) or LTB4 enhanced leukocyte adherence and emigration while reducing leukocyte rolling velocity. Sodium salicylate prevented all of the adhesion responses elicited by LTB4. Although salicylate did not affect the PAF-induced leukocyte adherence and rolling responses, it completely prevented the increased leukocyte emigration. These results indicate that aspirin promotes, whereas sodium salicylate inhibits, leukocyte-endothelial cell adhesive interactions at therapeutically relevant concentrations.

Animals↗
PubMed1992

Force-length properties and functional demands of cat gastrocnemius, soleus and plantaris muscles.

The purpose of this study was to measure isometric force-length properties of cat soleus, gastrocnemius and plantaris muscle-tendon units, and to relate these properties to the functional demands of these muscles during everyday locomotor activities. Isometric force-length properties were determined using an in situ preparation, where forces were measured using buckle-type tendon transducers, and muscle-tendon unit lengths were quantified through ankle and knee joint configurations. Functional demands of the muscles were assessed using direct muscle force measurements in freely moving animals. Force-length properties and functional demands were determined for soleus, gastrocnemius and plantaris muscles simultaneously in each animal. The results suggest that isometric force-length properties of cat soleus, gastrocnemius and plantaris muscles, as well as the region of the force-length relation that is used during everyday locomotor tasks, match the functional demands.

Animals↗
PubMed1992

Increases in soluble CD8 antigen in plasma, and CD8+ and CD8+CD38+ cells in human immunodeficiency virus type-1 infection.

Increases in plasma levels of soluble CD8 (SCD8) antigen and expansion of the CD8+ CD38+ lymphocyte compartment were early immunologic alterations frequently observed prior to detection of antibodies against human immunodeficiency virus type 1 (HIV-1) and diminution of CD4+ cells in subjects at risk to develop AIDS. These increases identified in the 49 seronegative homosexual men were manifest in all 164 homosexual subjects and 45 intravenous drug users (IVDU) positive for HIV-1 antibodies (HIV-1+), 19 patients with ARC, and 29 AIDS patients. Augmentation of plasma sCD8 antigen correlated with increases in both CD8+ and CD8+ CD38+ cells in HIV-1(-) homosexual men (r = 0.35, P less than 0.013; r = 0.48, P less than 0.0005; respectively) and the 258 HIV-1+ subjects (r = 0.25, P less than 0.0003; r = 0.33, P less than 0.0001, respectively). In vitro examination of unstimulated peripheral blood lymphocytes from HIV-1+ homosexuals and IVDU confirmed the fivefold higher constitutive levels of cellular release of sCD8 antigen in these subjects compared to heterosexual controls. Inclusion of radiolabeled amino acids during the 3-day culture period in the presence or absence of phytohemagglutinin resulted in negligible levels of radioactivity associated with the sCD8 antigen indicative of a lack of de novo synthesis. Throughout clinical progression to AIDS, sCD8 antigen levels continued to escalate relative to the numbers of CD8+ cells bearing CD38+ antigen. The data confirm the interrelationship between sCD8+ antigen and CD8+ and CD8+ CD38+ cells.

ADP-ribosyl Cyclase↗
PubMed1992

Long-term treatment with gabapentin for partial epilepsy.

Gabapentin was studied as an open-label 'add-on' antiepileptic drug in 35 patients with partial seizures. Follow-up at 6 months, 12 months, 18 months, and 24 months is reported. There was a trend toward improvement in simple (SPS) and complex partial seizures with it reaching significance for SPS at 12 and 24 months and for the weighted combination of seizures at 3 months. Five of nine patients were subsequently successfully converted to gabapentin monotherapy. Of those five, one is now seizure free and three are significantly improved since baseline. One remains with unchanged seizure frequency compared to baseline, but is experiencing less toxicity than at that time. This long-term observation suggests that the short-term effect demonstrated in blinded studies continues and that indeed some patients with refractory epilepsy can be maintained on gabapentin alone. Based on these findings, double-blind monotherapy trials of this drug are presently being conducted.

Acetates↗
PubMed1992

Increases in depressive symptomatology in the rural elderly: results from a cross-sectional and longitudinal study.

Depressive symptomatology was examined in a large sample of noninstitutionalized older adults using the Center for Epidemiological Studies-Depression scale (CES-D). Both cross-sectional and longitudinal data showed age-related increases in mean CES-D scores and increases in the percentage of respondents scoring at or above the cutoff score of 16. Variables collected at baseline in the longitudinal study from 2,032 participants 65 years of age and older were significant predictors of depressive symptomatology 3 and 6 years later. Baseline CES-D scores accounted for the largest proportion of the variance.

Activities of Daily Living↗
PubMed1992

Reduction of airborne allergenic urinary proteins from laboratory rats.

Allergy and asthma caused by proteins of laboratory animals, particularly rats and mice, are the most important occupational health hazards for the scientists and technicians who work with such animals. The influence of different cage litters, cage design, and stock density on measured rat urinary aeroallergen (RUA) concentrations has been examined in a room housing male rats, to determine practical means to reduce allergen concentration in animal laboratories. Eight hour static air samples were taken at 2 1/min and the RUA concentrations measured by radioallergosorbent test (RAST) inhibition. High RUA concentrations occurred when the animals were housed on wood based, contact litter (geometric mean (GM) sawdust 7.79 micrograms/m3; woodchip 6.16 micrograms/m3). The use of noncontact absorbent pads was associated with a significant decrease in RUA concentrations (GM 2.47 micrograms/m3; p less than 0.0001). Rat urinary aeroallergen concentrations fell more than fourfold when the animals were housed on woodbased, contact litter in filter top cages rather than conventional open top cages (GM filter top 0.33 micrograms/m3; open top 1.43 micrograms/m3; p less than 0.0001). The number of rats (stock density) strongly influenced the RUA concentration and a linear relation was found between the log(e) allergen concentration and stock density under these study conditions. The measurement of airborne particle size on cleaning out days showed that all litter types generated similar sized particles: more than 80% of the RUA was carried on particles larger than 8 microns in diameter for all litter types. The findings suggest that the exposure of animal husbandry personnel to RUA may be substantially reduced by the avoidance of contact litter, the use of filter top cages (where suitable), and by keeping stock density to a minimum.

Air↗
PubMed1992

Indomethacin-induced leukocyte adhesion in mesenteric venules: role of lipoxygenase products.

Although the pathogenetic mechanisms underlying indomethacin-induced mucosal injury remain undefined, the results from recent studies suggest that leukocyte adherence in gastric microvessels may be an important component of this injury process. The objective of this study was to determine whether clinically relevant plasma concentrations of indomethacin promote leukocyte-endothelial cell adhesive interactions in postcapillary venules. Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and the number of adherent (stationary for greater than or equal to 30 s) and emigrated leukocytes were measured in rat mesenteric venules. Repeat measurements of all parameters were obtained within 20 min after addition of either 2.5 or 25 micrograms/ml indomethacin to the mesenteric superfusate. In some experiments, rats were pretreated with either a leukotriene (LT) synthesis inhibitor (L 663,536), an LTD4 (MK-571) or LTB4 (SC 41930) receptor antagonist, misoprostol, or prostacyclin (PGI2). Indomethacin alone increased the number of adherent leukocytes, reduced both leukocyte rolling velocity and venular shear rate, but did not promote leukocyte emigration. L 663,536 and SC 41930 prevented all of the adhesive and hemodynamic alterations induced by indomethacin; misoprostol and PGI2, but not MK-571, exerted similar beneficial effects. These results indicate that indomethacin promotes leukocyte adherence in postcapillary venules through an LTB4-dependent mechanism.

Animals↗
PubMed1992

A modified anaesthetic induction chamber for rats.

The anaesthetic induction chamber for rats described in this paper has been designed for use in conjunction with a controlled delivery of halothane/O2 mixture and an anaesthetic scavenger system. Using this system rapid induction of anaesthesia is achieved using low levels of anaesthetic vapour without risk to the operator.

Anesthesia, Inhalation↗
PubMed1992

Effects of the nursing Mutual Participation Model of Care on parental stress in the pediatric intensive care unit--a replication.

The pediatric intensive care unit (PICU) hospitalization of a child is stressful for parents. Helping parents to decrease their stress is warranted so that they can function in a vital role that is therapeutic to them and their critically ill child. Although many interventions have been recommended to help parents decrease their stress, only the Nursing Mutual Participation Model of Care (NMPMC) has been tested in the clinical setting. This article reports a study that expands on Curley's original work by investigating the effects of the NMPMC on parental stress when implemented by PICU staff nurses. Fifty-six parents participated in the study, which used a quasi-experimental design. Sequential sampling placed the first 31 subjects into the control group and the next 25 subjects in the experimental group. The experimental group received care from staff nurses instructed in the NMPMC. The dependent measure was the Parental Stressor Scale:Pediatric Intensive Care Unit (PSS:PICU) administered within 24 to 48 hours of PICU admission, every 48 hours thereafter, and 24 hours after PICU discharge. The results indicated that parents in the experimental group perceived less stress than the control group, specifically the stress related to alterations in parental role in the PICU setting. Implications for nursing care are discussed.

Adult↗
PubMed1991

Human immunodeficiency virus type 1 (HIV-1) genomic sequences and distinct changes in CD8+ lymphocytes precede detectable levels of HIV-1 antibodies in high-risk homosexuals.

Polymerase chain reaction (PCR) identified regions of the gag, LTR, and env genes of human immunodeficiency virus type 1 (HIV-1) in 5 (13%) of 38 high-risk homosexual men who were negative for HIV-1 antibodies by Western blot (WB). Significant increases in CD8+ cells, particularly those bearing activation CD8+CD38+ and CD8+Ia+ antigens, and marked reductions in CD4+ cells were detected in WB-PCR+ subjects compared with 33 WB-PCR- homosexuals. WB-PCR+ subjects had impaired B cell but not T cell functions. Immunologic characteristics of WB-PCR+ homosexuals were indistinguishable from those of 17 WB+PCR+ subjects. Subjects progressing from WB-PCR- to WB-PCR+ to WB+PCR+ showed sequential phenotypic and functional alterations in their B and T cell compartments. These changes and the presence of HIV-1 genomic sequences were the first indications of HIV-1 infection and together with p24 antigenemia signified an inevitable progression to AIDS.

Adult↗
PubMed1991

Intrapleural tetracycline for spontaneous pneumothorax in acquired immunodeficiency syndrome.

Spontaneous pneumothorax is occurring in patients with the acquired immunodeficiency syndrome and Pneumocystis carinii infection with increasing frequency. These patients are typically poor surgical candidates. Conservative management using tetracycline sclerosis was performed with good results in a patient with acquired immunodeficiency syndrome and recurrent pneumothorax.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Gabapentin.

Explore the source record for details and available documents.

Acetates↗
PubMed1990

Diet composition, energy intake, and exercise in relation to body fat in men and women.

This study examined the relationships among body fat, diet composition, energy intake, and exercise in adults. Male (n = 107) and female (n = 109) adults aged 18-71 y (36.6 +/- 1.0 y, means +/- SEM) were hydrostatically weighed to determine body fat (5.7-49.0% of total weight). Diet and exercise behaviors were determined by use of a questionnaire. As body fat increased, percent of energy intake derived from fat increased (p less than 0.001) whereas the percent from carbohydrate decreased (p less than 0.001). There was no relationship between energy intake and adiposity although leanness and exercise were related (p less than 0.001). When subgroups of lean and obese subjects were compared, the lean subjects derived approximately 29% of their energy from fat and 53% from carbohydrate vs 35% and 46%, respectively, for the obese subjects. No differences were found between groups for energy intake but the lean individuals exercised more often than did the obese individuals. These data suggest that diet composition may play as important a role in fat deposition as do energy intake and lack of exercise.

Adipose Tissue↗
PubMed1990

The new disease model of alcoholism.

The new biopsychosocial disease model of alcoholism is examined from the perspective of recent biologic research. Studies of animal and human genetic predispositions suggest the presence of genetic influences over drinking behavior as well as biologic risk factors related to deficiencies in various neurochemicals. Ethanol affects the fluidity of cell membrane lipids, eventually causing membrane dysfunction. It also adversely affects the activity of two enzymes, monoamine oxidase and adenylate cyclase, that have important functions in the information processing system of the brain. Research on condensation products formed in the brain after alcohol consumption has provided clues to the development of alcoholism, but many questions remain unanswered. Alcoholism is clearly a multidimensional phenomenon in which biologic, psychological, and sociocultural factors interact to produce illness.

Alcoholism↗