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Biomedical subjects

R G Slavin

Publications and source records attributed to R G Slavin.

At least 91 records · Page 5Linked to original sources
PubMed1983

Immune response in experimentally induced uremia. V. Description of a model for chronic uremia in the rat that produces a long-term suppressive effect on T cell responses to mitogens.

This study describes a model for chronic uremia in the rat that produces a long-term suppressive effect on T cell responses to mitogens. We have found that (1) chronically uremic rats have significantly higher serum creatine levels than control rats and lymphocytopenia at all intervals tested after induction of uremia up to 4 1/2 months; (2) at all times tested after induction of uremia, the response of spleen cells from uremic rats to the T cell mitogens ConA and PHA was significantly suppressed as compared to control rats; (3) the severely suppressed response to PHA at all intervals tested after induction of uremia was eliminated by the removal of adherent spleen cells; and (4) adherent spleen cells, PMø, and AMø from chronically uremic rats are significantly more suppressive to control T cells than the corresponding control cells at all intervals tested after induction of uremia. Thus this animal model for chronic uremia is stable for at least 4 1/2 months and the effect of uremia on the response of lymphocytes to mitogens as well as on regulatory cells is not transient. Therefore this animal model can be used to study the effect of chronic uremia on the various parameters of the immune response.

Animals↗
PubMed1983

A fatal case of theophylline intoxication.

A fatal case of theophylline intoxication is presented in which a number of factors leading to a decrease in theophylline clearance and the patient's death were possibly operative. These included advanced age, chronic lung disease, liver disease, and administration of cimetidine. Since early symptoms of the toxic effects of theophylline can mimic peptic ulcer disease, cimetidine might be prescribed for the gastrointestinal symptoms with subsequent worsening of theophylline poisoning. Theophylline plasma concentration should be determined whenever drugs affecting theophylline clearance are administered simultaneously.

Aged↗
PubMed1982

Lymphocyte kinetics in acute uremia: redistribution of circulating lymphocytes to the bone marrow.

The mechanism(s) responsible for the peripheral blood lymphocytopenia found in uremia was investigated. Inbred Magnum guinea pigs were made uremic by ureteral ligation, and 1 day later injected with chromium (Cr)51-labeled syngeneic lymphocytes intravenously. 1 day later, the animals were sacrificed and organs counted for radioactivity. Sham-operated animals served as controls. Radioactivity in the lung and liver was the same or greater in the sham-operated animals than in uremic animals. In the blood and spleen, radioactivity was slightly higher in the uremic animals, while in the long bones this was significantly higher. In uremia therefore, there appears to be a redistribution of circulating lymphocytes to the bone marrow. The resultant lymphocytopenia may play a role in the immunologic incompetence seen in uremia.

Animals↗
PubMed1982

Immune response in experimentally induced uremia. IV. Characterization of suppressor peritoneal macrophages in the uremic rat.

The effect of unstimulated uremia PM phi on the response of syngeneic control NA spleen cells to mitogens was examined. Nonstimulated PM phi purified from uremic rats were found to be significantly more suppressive than similar numbers of control PM phi. It was found that indomethacin treatment, as well as anti-la treatment, only partially reverses the suppressive activity of uremic PM phi as compared to control PM phi, thus indicating that uremic suppressor PM phi have different characteristics from control PM phi. In addition, uremic PM phi suppress via a suppressor factor released to the supernatant over 24 hr incubation. The enhanced suppressor activity of uremic PN phi as well as their different characteristics may have relevance to the severely suppressed cell-mediated immunity observed in uremia.

Animals↗
PubMed1981

Skin tests in a primate model of allergic bronchopulmonary aspergillosis.

We have previously reported producing a primate model of allergic bronchopulmonary aspergillosis in which monkey precipitating IgG and transfused human IgE antibodies against Aspergillus fumigatus (AF) combined with aerosolized AF to produce an inflammatory response in the lung. In this study we attempt to demonstrate similar changes in the skin. Immunized and unimmunized monkeys with and without IgG precipitating antibody to AF were injected at multiple sites intradermally with normal human serum or human serum rich in IgE against AF. 1 day later each site was injected with AF. Serial skin biopsies were taken at intervals of 15 min, 1, 2, 6, 12, 24, and 48 h and light microscopic, immunofluorescent, and electron microscopic studies were performed. The most profound changes were associated with simian antibody (IgG) and human antibody (IgE) directed against AF and consisted or perivascular and interstitial neutrophilic infiltration at 2 h, eosinophils at 6 h, and mononuclear cells at 24 h. Immunofluorescent staining for fibrin-fibrinogen, IgM, and C3 was present and diapedesis of cells to extra-vascular dermal areas was evident. The skin appear to mirror the inflammatory changes seen in the lung in this primate model of allergic bronchopulmonary aspergillosis and should afford a useful model for further studies.

Animals↗
PubMed1981

Passive smoking. Effects on bronchial asthma.

Ten patients with bronchial asthma and ten control subjects were exposed to sidestream cigarette smoke (passive smoking) for one hour in an environmental chamber. All subjects showed the same increase in carboxyhemoglobin as a result of the exposure: 0.40 percent. The asthmatic group demonstrated a significant linear decrease in pulmonary function during this exposure. After one hour of smoke, FEV1 decreased 21.4 percent, FEF25-75% decreased 19.2 percent, and FVC decreased 20.0 percent in the asthmatic patients. These alterations were readily reversible in all subjects when given inhalations of metaproterenol following the exposure. The control subjects showed no change in pulmonary function when exposed to identical conditions. These data show that nonsmokers with bronchial asthma are at risk when exposed to sidestream cigarette smoke in an environmental chamber.

Adult↗
PubMed1981

Immune response in experimentally induced uremia. II. Suppression of PHA response in uremia is mediated by an adherent, Ia-negative and indomethacin-insensitive suppressor cell.

The characteristics of the adherent suppressor cell in uremic rats were examined. We found that: 1) adherent spleen cells from uremic rats display a more potent suppressor activity than do control adherent cells; 2) the suppression that is mediated by uremic adherent spleen cells cannot be eliminated by pretreatment with indomethacin, whereas the suppression that is mediated by naturally present adherent cells in the control rat is reversed by pretreatment with indomethacin; 3) the uremic adherent suppressor cell does not have Ia antigens that can be detected by the monoclonal antibodies OXL, whereas control adherent cells have Ia antigens on their surface; 4) both the control and uremic adherent suppressor cells are insensitive to mitomycin C and do not have any detectable levels of Thy 1 antigens on their surface. It appears that immune suppression in uremic rats is mediated by an adherent cell that differs from adherent cells present in control animals. The suppression in uremic rats is either not mediated by prostaglandins or may be mediated by preformed prostaglandin synthetase products.

Animals↗
PubMed1980

Multicenter study of flunisolide aerosol in adult patients with steroid-dependent asthma.

Seventy-three adult, steroid-dependent asthmatic patients participated in a 16-wk, double-blind study testing the efficacy of flunisolide aerosol. Forty received flunisolide, and 33 received placebo. The mean daily prednisone requirement of patients receiving flunisolide fell 59.2% during the testing period, and that of the patients receiving placebo fell 19.7%. The median daily prednisone dose dropped 74.4% in the flunisolide group and 4.2% in the placebo group (p = 0.006). In the flunisolide group 75% tapered use of oral steroids 50% or more, and 27.5% stopped taking oral steroids completely. In the placebo group 36% tapered use of oral steroids 50% or more, and only 12% stopped taking them completely. Despite their reduction in systemic steroids, those patients receiving flunisolide achieved significantly greater reduction in the daily severity of wheezing (p = 0.014) and frequency of asthma attacks (p = 0.049) than did those receiving placebo. In the final evaluation of therapeutic response, 70% of patients receiving flunisolide were rated as having a very good or good response, and 30% were rated as having a fair or poor response. In contrast 33% of patients receiving placebo were rated as very good or good, and 67% were rated as fair or poor (p = 0.0009). No serious reactions were reported. Plasma cortisols showed an average increase of 42.9% in the flunisolide group but no change in the placebo group. Flunisolide aerosol is a well-tolerated and effective agent in the treatment of steroid-dependent asthma.

Adolescent↗
PubMed1978

Asthma in adults III: occupational asthma.

Recognition of the disease may be difficult, since symptoms may be atypical and a temporal association with exposure is often obscure. Attention is given to the ways of differentiating the truly allergic in origin from other types of occupational asthma.

Air Pollutants, Occupational↗