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Biomedical subjects

R R Watson

Publications and source records attributed to R R Watson.

244 records · Page 14Linked to original sources
PubMedDate not supplied

Cocaine metabolite (benzoylecgonine) in hair and urine of drug users.

Two methods of drug detection, urinalysis and hair analysis, were compared with respect to the efficiency of identification of drug use in a population of men living on the Arizona-Mexico border. The standard curve of cannabinoids in urine was linear to 20 ng/mL. The GC/MS levels for all cannabinoids combined in urine were very similar to that obtained by radioimmunoassay (RIA), 91% concordance. Similar results were obtained from samples analyzed dually for the cocaine metabolite benzoylecgonine (BE) after spiking. As determined by RIA of urine, 74% of the subjects were positive for cannabinoids. The majority were in the range of 100-1000 ng/mg creatinine. The pattern of excretion of THC metabolites with respect to the verbally reported time of first use was fairly normal, with the peak rate of elimination 13-24 hours following the last reported use. Washed hair samples were extracted by overnight acid hydrolysis. Urine samples and neutralized hair extracts were analyzed for cocaine and BE by RIA. Of the hair samples, 55% contained cocaine/BE, as compared with only 4.3% of the urine samples. Most hair samples contained cocaine/BE in the range of 25-100 ng/sample (100 mg hair). All hair samples testing negative for cocaine/BE by RIA also tested negative by GC/MS, and four samples containing the highest amounts of cocaine and BE by RIA were similarly found to contain the highest amounts by GC/MS. Hair analysis, therefore, gives a wider window of detection of drug use than does urinalysis and shows merit in the confirmation of cocaine use in small clinical research studies.

Adolescent↗
PubMedDate not supplied

Cellular immune functions, endorphins, and alcohol consumption in males.

The effects of alcohol abuse on cellular immune functions were measured by various levels of alcohol use in adult men. Total lifelong abstainers were used as controls. Previous abusers, current abusers, and patients with alcoholic cirrhosis or pancreatitis were age-matched to controls. T-lymphocyte mitogenesis stimulated by phytohemagglutinin and concanavalin A was generally reduced in peripheral blood lymphocytes of current and previous alcohol consumers, although the decrease was not statistically significant. B-cell mitogenesis stimulated by pokeweed mitogen was not changed by previous alcohol consumption. The number of T-cells was not changed by either previous or current alcohol abuse. T-helper cells were significantly increased and T-suppressor cells increased only in the patients with alcoholic cirrhosis or pancreatitis. The percentage of T-lymphocytes with T-suppressor characteristics in controls was 27% while in alcoholic cirrhosis or pancreatitis subjects it was 16%. Plasma corticosteroid levels were significantly increased in people currently consuming alcohol (12.1 +/- 1.1 mg/dl) compared to controls (7.7 +/- 1.1). The corticosteroid levels were also higher in previous alcohol abusers although not statistically significant. Plasma endorphin levels were increased by severe alcohol abuse in the patients with cirrhosis or pancreatitis to 25.03 +/- 6.74 from 11.85 +/- 2.48 pg/ml in controls.

Adult↗
PubMedDate not supplied

Suppression of resistance to Giardia muris and cytokine production in a murine model of acquired immune deficiency syndrome.

Peyer's patch (PP) T cells through the production of appropriate cytokines foster the development of immunity to the intestinal protozoan parasites such as Giardia. T cell destruction by the human immunodeficiency virus precedes the development of acquired immune deficiency syndrome. Thus, HIV may increase susceptibility to intestinal parasite infections. Therefore, we measured the resistance and T cell cytokine responses to Giardia in C57B1/6 mice infected with the retrovirus LP-BM5 which produces a murine AIDS (MAIDS). Mice with MAIDS and controls were intragastrically challenged with 1 x 10(5) G. muris cysts. Fecal counts were measured weekly following challenge. Also, PP T cell production of interleukin (IL)2, IL3, IL4, and Interferon-gamma in response to G. muris trophozoite antigens displayed on antigen presenting cells were measured at these times. Prior to day 14 of the infection, the number of Giardia cysts in the retrovirus group paralleled that in controls. However, by day 21 after Giardia infection, mice with MAIDS failed to clear the Giardia cysts from the intestine while the control mice were completely free of cysts. IL2 and IL4 production in response to Giardia trophozoites by unfractionated PP lymphocytes were severely depressed in the retrovirus infected group, while IFN-gamma production was increased. Depressed cytokine production was most likely due to depressed PP T cell numbers. When fractionated enriched T cells were adjusted to a uniform concentration in in vitro immunization cultures, the production of IL2 and IL4/IL5 were similar between retrovirus infected compared with control mice. Recoverable PP T cells were lower in mice with MAIDS.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Suppressed mucosal lymphocyte populations by LP-BM5 murine leukemia virus infection producing murine AIDS.

LP-BM5 murine leukemia virus (MuLV) infection induces an immunodeficient state in susceptible strains of mice. It has been previously characterized at the level of spleen and peripheral lymph nodes. We recently demonstrated that LP-BM5 MuLV-infected mice lost intestinal host resistance to common opportunistic pathogens. In this article we investigated how murine retroviral infection alters the differentiation of IgA B cell precursors in Peyer's patches (PP), mesenteric lymph nodes (MLN), and the intestinal lamina propria (ILP). After 4 months of LP-BM5 MuLV infection, there was a significant decrease in the absolute numbers of Thy1+, CD4+, and CD8+ cells in PP with a concomitant decrease in the percentage and in the absolute numbers of surface IgA+--(sIgA+) and surface IgM+--bearing (sIgM+) cells. Infection also produced an enlarged MLN with a six-fold increase in cell numbers and a decrease in the relative percentage of sIgA+, cytoplasmic IgA+, and cytoplasmic IgM+ cells. However, murine retrovirus infection caused no significant changes in the percentages of Thyl+, CD4+, CD8+, and CD5+ cells in the MLN. After 4 months of murine retrovirus infection cIgA+ cells from MLN were not able to populate the intestinal lamina propria as the number of IgA plasma cells was significantly decreased. Moreover, there was a concomitant decrease in the number of CD4+ cells per field in the ILP. These results suggest that murine retrovirus infection favors the expansion of IgA B cell precursors at the level of MLN, while simultaneously interfering with the terminal differentiation step and thus preventing IgA plasma cell precursors from seeding the ILP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Immunization outreach using individual need assessments of adults at an army hospital.

A comprehensive assessment of the immunization status of 2,451 adults was carried out at Walter Reed Army Medical Center's Allergy-Clinical Immunology Service, Washington, DC, during an influenza immunization program from October 1985 through February 1986. More than 66 percent of those screened needed either immunization other than for influenza, or an immunologic test, a decline from 72 percent noted during a 1984-85 influenza immunization program. The mean number of interventions was 2.00 per patient in the 1985-86 program and 2.26 during the previous program. Of patients screened in the period 1985-86, 20.5 percent received diphtheria-tetanus toxoids, 15.7 percent received pneumococcal vaccine, and 23.1 percent received a tuberculin skin test. Vaccination or titers for measles were ordered for 10.4 percent, for rubella for 10.9 percent, and for hepatitis B for 20.3 percent. Assessment of those who came to the clinic for influenza vaccination in the second program demonstrated that the needs of some patients had been met in the first program. However, a general lack of immune protection existed in the majority of patients screened in the second program. In both programs, those older than 59 years needed pneumococcal vaccine and diphtheria-tetanus toxoids more frequently than the general population. The means of the numbers of interventions and the percentages of patients needing intervention other than influenza vaccine declined from the first program to the second, suggesting progress in meeting some individual immunization needs in a large and changing ambulatory population.

Adult↗
PubMedDate not supplied

Nutrition and immunity.

Severe protein deficiencies such as kwashiorkor result in immunosuppression of humoral cellular and mucosal immune systems. These suppressions result in a greater incidence of disease in animals and humans and create increased risks of morbidity and mortality due to infectious disease or neoplasias. The effect of moderate protein-calorie deficiency on immuno-competence appears to be highly variable in studies with experimental animals. In young animals, some parts of the host-defense systems are stimulated while other are inhibited. These effects appear to result in long life-spans. This may be due to slower maturation and, hence, a slower decline of host-defense systems in the moderately malnourished animals.

Adult↗
PubMedDate not supplied

The kinetics of cytokine secretion and proliferation by mesenteric lymph node cells during the progression to murine AIDS, caused by LP-BM5 murine leukemia virus infection.

A murine acquired immunodeficiency syndrome (MAIDS) is induced in genetically susceptible strains of mice inoculated with LP-BM5 murine leukemia virus. It is characterized by progressive lymphoproliferation, profound immunodeficiency, and the subsequent loss of resistance to opportunistic pathogens, including intestinal pathogens. Cellular and/or humoral immunity of gut-associated lymphoid tissues may play a key role in the elimination of these pathogens. We have previously demonstrated reductions in the number of mucosal T and B cells in MAIDS. In this study, the cytokine production by mesenteric lymph nodes (MLN) cells and their proliferative response to mitogens during MAIDS were investigated. Alterations were observed in the kinetics of MLN cell proliferation and cytokine secretion by in vitro mitogen-stimulated MLN cells during the retrovirus infection. Cytokine production was abnormally changed, with a gradual decrease in interleukin-2 (IL-2) production as well as an increase in IL-5 and IL-6 secretion. Interferon-gamma production was increased during the progression to MAIDS. The dysregulated release of cytokines by MLN cells due to retrovirus infection could lead to immune dysfunction. These data indicate that dysregulated cytokine secretion by MLN cells may be responsible for impaired mucosal immunity in AIDS, explaining the dramatic increase of opportunistic intestinal pathogens in individuals with AIDS.

Animals↗
PubMedDate not supplied

Is vitamin E supplementation a useful agent in AIDS therapy?

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by a retrovirus infection, representing the end point in a progressive sequence of immunosuppressive changes. The literature is briefly summarized as to immunological, nutritional and other pathological modifications caused by AIDS, and properties of immunoenhancing, anti-oxidant and undernutrition-restoration of vitamin E supplementation. All these abnormalities in AIDS are similar to those that are stimulated or restored by intake of high doses of vitamin E. The drawbacks of pharmacological therapy like zidovudine (AZT), e.g. deleterious toxic side effects, inability to improve the immune dysfunctions and undernutrition initiated by the retrovirus infection, and finding of AZT-resistant HIV strains, necessitate new strategies for the clinical trials of novel therapies to treat AIDS with the existing medical therapies. Low toxicity nutritional agents with immunoenhancing and antioxidant activities like vitamin E may help to normalize retrovirus-induced immune dysfunctions, undernutrition and other pathological symptoms, thereby retarding the progression of the disease to AIDS. To address this vitamin E therapeutic role in HIV-positive individuals, This paper presents a review of vitamin E-related therapeutic roles in animals and humans, thereby showing why vitamin E supplementation could be used as a useful therapeutic agent in human AIDS therapy. Since there is a paucity of information available regarding the nutritional therapy in AIDS individuals, our purpose is to provide evidence from animal models or humans of the potential therapeutic role of vitamin E supplementation in the treatment of AIDS individuals.

Acquired Immunodeficiency Syndrome↗