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Biomedical subjects

R R Watson

Publications and source records attributed to R R Watson.

At least 127 records · Page 7Linked to original sources
PubMed1992

Modification of lymphoid subsets by chronic ethanol consumption in C57Bl/6 mice infected with LP-BM5 murine leukemia virus.

The relatively high incidence of infectious disease in alcoholics is attributed to the immunosuppressive effects of alcohol. The potential role of alcohol as cofactor in HIV infection and in the development and expression of AIDS is suggested but unknown. In order to understand better the contribution of alcohol to immune dysfunction following HIV infection, we assessed the presence of specific markers on thymus and spleen cells in C57B1/6 mice infected with LP-BM5 murine leukemia virus and fed ethanol-containing diets. In the first experiments, mice were fed diets containing 0, 4.5, 5.5, and 6% (v/v) ethanol for 14 weeks. High ethanol exposure (6%) resulted in severe dehydration and death after 7 weeks. Although moderately low intakes of ethanol did not significantly modify percentages of T and B cells, they increased the absolute number of mature T, B, and CD4+ cells and decreased percentages of Thy 1.2+ cells. In the second experiment, mice were infected with LP-BM5 murine leukemia retrovirus and fed diets containing 5% ethanol in a regimen of 5 days of ethanol diet and 2 days of diet without alcohol for 12 weeks. Ethanol exposure in the retrovirally infected mice showed a marked decrease in Thy 1.2+ (P < 0.05). Moderate decreases in percentages of CD4+, CD8+, CD5+ cells and an increase in Ia+ cells were also observed in the retrovirus/infected ethanol-treated mice. Moderate ethanol consumption during retroviral infection induced mild/moderate changes on lymphoid cells. Ethanol consumption may accelerate the progression of murine AIDS through such changes in the lymphoid cells of the spleen.

Alcoholism↗
PubMed1992

Influence of the level of dietary ethanol in mice with murine AIDS on resistance to Streptococcus pneumoniae.

Chronic ethanol consumption impairs cellular immune functions. This may explain the increased occurrence of various opportunistic infections in heavy ethanol users. Immunological alterations associated with Acquired Immune Deficiency Syndrome (AIDS) also permit more opportunistic infections. In this study, we used a murine model of retrovirus infection induced by LP-BM5 murine leukemia virus. The combined effects of ethanol use and early retroviral infection (prior to the development of AIDS) on resistance to Streptococcus pneumoniae were investigated. Consumption of ethanol by non-retrovirus-infected mice resulted in decreased resistance to S. pneumoniae. However, retrovirus-infected mice fed a diet containing high concentrations of ethanol (6 and 7% v/v) exhibited a greater resistance to S. pneumoniae infection than retrovirus-infected mice fed diets with lower concentrations (5%) or no ethanol. The total number of white blood cells also decreased as serum ethanol levels increased. There were also fewer lymphocytes and more neutrophils and monocytes in retrovirus-infected mice fed ethanol. Diet consumption decreased as the concentration of ethanol increased in the diet. Consumption was dependent upon the dark-light cycle. The highest diet consumption was observed during the first 4 hr of the dark period. The level of ethanol in serum was influenced by the amount of the diet consumed and its ethanol concentration. Both retrovirus infection and ethanol consumption effected survival after S. pneumoniae infection.

AIDS-Related Opportunistic Infections↗
PubMed1991

The effects of 13-cis-retinoic acid and beta-carotene on cellular immunity in humans.

Deficiency of vitamin A and/or its precursors has been associated with increased cancer risk in animals and humans. Therapeutic trials of vitamin A and related compounds have demonstrated activity in several cancerous and precancerous conditions. The authors measured the effects of a retinoid, 13-cis-retinoic acid, and a carotenoid, beta-carotene, on the human immune system in vivo in conjunction with their use in ongoing clinical trials. Immune cell subpopulations were analyzed by quantifying the expression of markers using flow cytometric study. Both compounds produced significant effects on immune cell populations. 13-cis-Retinoic acid resulted in an increase in the percentage of peripheral blood lymphoid cells expressing surface markers for T-helper cells with only minimal effect on natural killer cell marker expression. In contrast, beta-carotene produced an increase in the percentage of cells expressing natural killer cell markers with smaller effect on T-helper markers. Modest increases in the percentage of cells expressing Ia antigen, transferrin, and interleukin-2 receptors were produced by both drugs. These results suggest that retinoids and carotenoids can produce major changes in immune cellular marker expression in vivo in humans at doses relevant to their potential clinical use.

Adult↗
PubMed1991

Modulation of tumor necrosis factor and gamma interferon production by cocaine and morphine in aging mice infected with LP-BM5, a murine retrovirus.

The actions of retroviral infections, aging, and cocaine and morphine injection on cytokine production were investigated in C57BL/6 female mice. Retroviral infection with LP-BM5 murine leukemia virus was further developed as a model of murine acquired immunodeficiency syndrome (AIDS). The effects of cocaine and morphine on gamma-interferon (IFN) and tumor necrosis factor (TNF) production in vivo and with isolated spleen cells were measured by a sandwich enzyme-linked immunosorbent assay (ELISA) method. Serum IFN was generally not detected in any group except mice injected with saline and young mice infected with LP-BM5 virus. Splenocytes from mice with murine AIDS produced less IFN when stimulated in vitro by ConA. In aged mice, IFN production by spleen cells was severely suppressed by retroviral infection. Cocaine had a tendency to suppress IFN production by stimulated cells in vitro. Morphine tended to reduce IFN production by spleen cells from retrovirally infected animals. The serum TNF level in mice with murine AIDS was elevated creating higher levels in morphine and morphine plus cocaine treated uninfected mice while cocaine injection eliminated serum TNF. When stimulated in vitro by lipopolysaccharides (LPS), splenocytes from mice with murine AIDS also produced more TNF than uninfected controls. TNF production in vitro and in vivo was significantly increased by retroviral infection. Therefore, results indicate that cocaine and retroviral infection modulate TNF and IFN production.

Aging↗
PubMed1991

AIDS, drugs of abuse and the immune system: a complex immunotoxicological network.

Two of the most interesting questions often asked about AIDS is why many people do not become immunodeficient or get complicating disease when first infected with Human Immunodeficiency Virus (HIV) and what are the "risk factors" making some individuals more susceptible to the disease. A large majority of people with AIDS have a well established history of drug and alcohol abuse. Both drugs of abuse and alcohol have immunotoxic properties as evidenced by a number of studies. These include marked changes in the cellular, humoral and other components of the immune defense mechanism. Such a compromise of the immune system can render it susceptible to the development of AIDS after HIV infection. This paper reviews the evidence suggesting possible links between substance abuse and its immunotoxicology, and their possible roles in the pathogenesis of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Splenocyte subsets in normal and protein malnourished mice after long-term exposure to cocaine or morphine.

An experimental model which resembles human drug addiction was developed to study the effect of chronic drug (cocaine or morphine) administration on the immune system. As malnutrition has been associated with drug use, a low protein diet has been evaluated for its contribution to the impairment of the immune system during cocaine/morphine addiction. Female C57BL/6 mice that received a 20% or 4% casein diet were studied. Both drugs were administered intraperitoneally daily for 11 weeks and drugs were administered in increasing daily doses, beginning after 3 weeks of diet consumption. Doses of cocaine began with 5 mg/kg body weight and reached the maximum dose of 40 mg/kg/day at the fourth week. Doses of morphine gradually increased from 10 mg/kg to 75 mg/kg body weight with the maximum dose reached after 5 weeks of treatment. Cocaine administration reduced body weight, particularly in the low protein diet group, and spleen weight in protein malnourished mice. Cocaine as well as saline injected mice showed a decrease in the percentage of CD4+ CD8+ and Mac-1+ cells and an increase in B cells in the spleens of well nourished mice. Morphine-treated mice showed similar results to those observed in cocaine or saline treated mice. These results suggest that cocaine, morphine or saline injection can alter the percentage of cells that express a defined phenotype independently of the nutritional status of the subject. Moreover, the effect appears dependent on a stress mediated process.

Animals↗
PubMed1991

Marijuana components stimulate human peripheral blood mononuclear cell secretion of interferon-gamma and suppress interleukin-1 alpha in vitro.

We investigated the in vitro effects of both psychoactive and nonpsychoactive marijuana components on leukocyte secretion of the immunoregulatory cytokines interleukin-1 alpha (IL-1), tumor necrosis factor alpha (TNF), interferon-gamma (IFN) and interleukin-2 (IL-2). Psychoactive delta-9-tetrahydrocannabinol (THC) and nonpsychoactive cannabidiol (CBD) were added to cultures of mitogen-activated human peripheral blood mononuclear cells (PBMC) and the concentrations of IL-1, TNF, IFN and IL-2 in culture supernatants were measured by ELISA systems. Concentrations of THC and CBD, comparable to plasma levels found after smoking marijuana (10-100 ng/ml), increased the concentration of measurable IFN (139 and 68%), while high concentrations of both cannabinoids (5-20 micrograms/ml) completely blocked synthesis and/or release of this cytokine. CBD was also shown to decrease the measurable quantity of both IL-1 and TNF. In contrast to the effects on IFN, IL-1 and TNF, both cannabinoids, had no effect on IL-2 secretion. This report suggests that both psychoactive and nonpsychoactive components of marijuana are immunomodulating and can potentially alter cytokine secretion of human PBMC.

Adult↗
PubMed1991

Cocaine immunotoxicity: abnormal cytokine production in Hispanic drug users.

Peripheral blood lymphocytes from 47 Hispanic poly-drug users with a history of cocaine abuse were analyzed for in vitro production of interleukin-1 (IL-1), interleukin-2 (IL-2), gamma-interferon (IFN) and plasma levels of soluble IL-2 receptor (SIL-2R). Cocaine use was confirmed and quantified by analysis of hair and urine samples, and subjects were grouped into 3 based on the extent of cocaine metabolites detected. No significant differences in IL-1 and IFN production were seen between the 3 groups. However, subjects with higher levels of cocaine in hair also showed higher levels of IL-2. In addition, a positive correlation was seen between cocaine concentrations and IL-2 levels. A corresponding negative correlation was seen between cocaine levels and levels of plasma SIL-2R. These findings suggest modulation of the IL-2 network by cocaine in poly-drug users.

Adolescent↗
PubMed1991

Stimulation of natural killer cell activity by murine retroviral infection and cocaine.

The effects of cocaine and murine AIDS on natural killer (NK) cell activity in C57BL/6 mice was studied. Cocaine may play a major role in the development and progression to AIDS in the human population. Chronic intraperitoneal injection of cocaine was shown to cause an increase in NK cell activity over those of saline-treated animals. Infection with LP-BM5 murine leukemia retrovirus was also shown to increase NK cell activity. NK cell activity was increased in retrovirally infected mice treated with cocaine beyond that of mice treated with cocaine alone. This study indicates an important immunomodulatory effect of cocaine on NK cell activity, especially when combined with the effects caused by retroviral infection.

Adjuvants, Immunologic↗
PubMed1991

Immunotoxicity of poly-drug use: abnormalities in the active and high-affinity CD2 antigen (E-rosette receptor) bearing T-lymphocytes.

The E-rosetting profiles of T-cells were studied in 47 subjects with a history of poly-drug and alcohol abuse, and compared with 15 normal controls. No change was evident in numbers of total rosette-forming cells (TRFC). However, there was reduction in active and high-affinity rosette-forming cells (ARFC and HARFC). These two subsets of CD2-antigen-bearing T-cells are considered as immunocompetent surveillance cells. Thus the abnormality associated with them could be due to the combined immunotoxic effects of substance abuse, modulating the immune status of drug users.

Adult↗
PubMed1991

Effect of beta-carotene on lymphocyte subpopulations in elderly humans: evidence for a dose-response relationship.

The effects of various doses (0, 15, 30, 45, and 60 mg/d) of supplementary beta-carotene were evaluated. The percentage of lymphoid cells with surface markers for T-helper and natural killer (NK) cells and cells with interleukin 2 (IL-2) and transferrin receptors were significantly and substantially increased in peripheral blood mononuclear cells collected from older human adult volunteers after supplementation with greater than or equal to 30 mg beta-carotene/d for 2 mo. The increase in the percentage of cells with markers of NK cells and in expression of IL-2 receptors was dose dependent. The plasma concentrations of beta-carotene were also elevated significantly; however, there was no increase in the amount of retinol present in plasma. This indicated that immunomodulation induced by beta-carotene may be due to the carotenoid rather than to an increased amount, and hence actions, of vitamin A. These results support the role of immunostimulation as a potential mechanism of action of beta-carotene with cancer-prevention potential.

Aged↗
PubMed1991

Cryptosporidiosis facilitated by murine retroviral infection with LP-BM5.

LP-BM5 murine leukemia virus infection caused alterations in splenic T cell subsets in adult C57BL/6 female mice. Prolonged infection resulted in increased immunosuppression and a concomitant decreased resistance to Cryptosporidium parvum infection. Significant Cryptosporidium colonization of the intestinal villi was seen 10 days after oral challenge in mice infected with murine retrovirus for 3 months but not in non-virally infected controls. Parasite numbers per villus of retrovirally infected mice were 20-fold higher than in controls, which showed only occasional parasites. Feces from most virally infected mice but none from controls contained oocysts. Cryptosporidium infection in mice after 4 and 5 months of retroviral infection was accompanied by severe immunosuppression and parasite levels 50-5000 times higher than in controls. A high level of infection persisted 21 days after Cryptosporidium challenge in virally infected mice, while controls cleared their transient and marginal infection. These results further characterize LP-BM5 infection as a murine model of retrovirally induced acquired immune deficiency.

Animals↗