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Biomedical subjects

G Sussman

Publications and source records attributed to G Sussman.

23 records · Page 2Linked to original sources

Production of a suppressor factor by CD8+ lymphocytes activated by mycobacterial components.

The lipid component present in high-molecular-mass fractions with molecular masses of greater than 200 kDa derived from Mycobacterium tuberculosis extracts passaged through Sephacryl S.200 columns activate CD8+ lymphocytes to suppress lymphocyte blastogenesis. Suppression is mediated by the release of suppressor molecules by these CD8+ lymphocytes. Release of suppressor molecules occurs as early as 2 h following pulsing with the high-molecular-mass mycobacterial components and is maximal at 24 h, after which their release declines rapidly. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblotting indicates that the active components are carbohydrate moieties with approximate molecular masses of 122 to 148 kDa. Our results suggest a mechanism of interaction between mycobacteria and host mononuclear cells such that mycobacterial lipids, once exposed, activate CD8+ suppressor lymphocytes. Activation of these lymphocytes results in the release of carbohydrate-containing molecules that ultimately inhibit the blastogenesis of other lymphocytes.

Antigens, Differentiation, T-Lymphocyte↗

Controlled trial of H1 antagonists in the treatment of chronic idiopathic urticaria.

The efficacy of astemizole, diphenhydramine, and hydroxyzine hydrochloride in the treatment of chronic idiopathic urticaria was evaluated in this 3-month double-blind, randomized, parallel group study. Thirty-six adult patients were randomly assigned, 13 to the astemizole group (10 mg daily), 12 to the diphenhydramine group (25 mg t.i.d.), and 11 to the hydroxyzine hydrochloride group (25 mg t.i.d.). Demographic data were statistically similar for all variables assessed in the three treatment groups. Seven (58%) of the diphenhydramine patients withdrew before the end of the study, six because of lack of efficacy and one because of drowsiness. Two (18%) of the hydroxyzine hydrochloride patients withdrew, one because of lack of efficacy and one because of drowsiness. Two patients (15%) in the astemizole group withdrew, one because of adverse reaction, and the other because of lack of efficacy. Mean total symptom scores and mean individual symptom scores were lower in the astemizole group than in the other two groups. Wheal area measurements (0.1 mg/mL histamine challenge) decreased more in the astemizole and hydroxyzine hydrochloride groups than in the diphenhydramie group (P = .02). With regard to symptoms, 12/13 patients in the astemizole group improved clinically during their treatment period, versus 8/11 in the hydroxyzine hydrochloride group and 5/12 in the diphenhydramine group. The mean time to first observed therapeutic effect (maintained for three consecutive days) was 5.5 days in the astemizole group, 10.9 days in the hydroxyzine hydrochloride group, and 7.2 days in the diphenhydramine group. In this study, astemizole was as effective as hydroxyzine in patients treated for chronic idiopathic urticaria.

Adult↗

Hypersensitivity to natural latex.

Rubber hypersensitivity is well described but usually as a contact dermatitis caused by chemicals added during the process of making natural latex or synthetic rubber. IgE-mediated reactions, mainly contact urticaria, have rarely been reported in Europe. We report a case of immediate hypersensitivity to latex. A 34-year-old female operating room nurse developed hand eczema to natural latex. On two occasions, while she was gloving for surgery, she had the following reactions: flushing, tachycardia, urticaria, angioedema, wheezing, and light-headedness. Prick and patch testing to thiuram mix, mercaptobenzothiazole, phenylenediamine mix, and carbamate mix (common rubber additives) were negative. Prick tests to natural latex elicited a 4+ reaction associated with immediate flushing, tachycardia, urticaria, and light-headedness. Five control subjects did not react. IgE antibodies to latex by RAST demonstrated 17.7% binding (control, 4%). This case demonstrates that natural latex can cause IgE-mediated symptoms. The route of exposure was cutaneous absorption of relevant latex allergens. As the use of latex rubber products continues to escalate, more cases are likely to occur.

Adult↗

Considerations of hospital viability in rural Texas.

The rural hospitals in Texas face the same situation as rural hospitals throughout the country. Unfortunately, little data are available to define the scope or possible duration of the problem. However, rural hospital administrators currently believe that their facilities are being hurt by increased government regulation and that today's figures on average daily census indicate that the problem could threaten their hospital's long-term viability. Initial investigations have shown that the problem of casualty is a complex one; multiple factors interact to exacerbate the situation, such as more stringent enforcement of Medicare certification standards, review of claims and quality of care by PROs, and the use of PPS. Other factors cited include the economic recession, the exodus of young people from rural areas to urban areas, the high cost of technology, and the preadmission review by insurance companies. A study that will both sample and survey rural hospital viability using financial ratio analysis and service utilization data is presently being undertaken to provide some responses to these concerns. Further, it will later examine how rural hospital administrators are responding to the problem of decreased hospital viability. It is possible that new coping strategies may be developed from the study results that will change present modes of health care delivery and result in regional networks and more diversified health care services.

Cost Control↗

Suppression of cytokine production by supernatants from CD8+ lymphocytes activated by mycobacterial fractions: the role of interleukins 4 and 6.

Supernatants derived from CD8+ lymphocytes treated with mycobacterial components, or the partially purified carbohydrates from these supernatants, increased the production of IL-4 and IL-6 by mononuclear cells. The addition of anti-IL4 or anti-IL6 antibodies to LPS stimulated MN cells incubated with supernatants from CD8+ lymphocytes or carbohydrates resulted in the restoration of other cytokine production by these MN cells. Recombinant IL-4 and IL-6 on their own suppressed the production of IL-1 beta, TNF-alpha, IL-2 and IFN-gamma by mononuclear cells. Such suppression could be reversed with antibodies to IL-4 and IL-6. The addition of rIL-4 and rIL-6 did not increase the suppression of cytokine production induced by suppressor supernatants or carbohydrates. Interleukin 4 decreased the production of IL-6 by MN cells; whilst IL-6 suppressed IL-4 production in a dose dependent manner. Both effects could be reversed with the appropriate antisera. Our results suggest that mycobacteria could evade host immunity by inducing the production of IL-4 and IL-6 by host mononuclear cells. These cytokines, in turn, would suppress the production of other cytokines necessary for effective cellular immunity.

CD8-Positive T-Lymphocytes↗