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Biomedical subjects

R J Sharbaugh

Publications and source records attributed to R J Sharbaugh.

At least 37 records · Page 2Linked to original sources

An evaluation of the efficacy of a hospital infection control program.

To establish the credibility of the hospital infection control program at a major southeastern medical university hospital, the incidence rates of nosocomial infections were analyzed statistically following the implementation of an extensive infection control program. Continuous hospital-wide surveillance included documentation of all detected nosocomial infections by both site and service. Chi-square analysis of the incidence of infection during the years 1977 to 1979 revealed significant decreases in several distinct areas. The overall incidence rate of infection steadily declined from 100.8/1000 admissions in 1977 to 59.9/1000 in 1979. Decreases in the incidence of urinary tract, respiratory tract, and surgical wound infections were primarily involved. Analysis of incidence rates by service revealed that general surgery was responsible for much of the observed decrease. In contrast, none of the intensive care units exhibited a significant decline in morbidity rates over the 3-year period. It is concluded that involvement of infection control personnel at all levels of patient care as a part of a sophisticated hospital infection control program can result in a significant reduction in the incidence of nosocomial infections.

Cross Infection↗

Brief note. Induction of experimental allergic encephalomyelitis in sheep with purified bovine basic protein and adjuvant.

A large animal model for the induction of experimental allergic encephalomyelitis to study the immunological disease parameters through closed-circuit extracorporeal thoracic duct filtration was successfully produced in two different strains of sheep. This study demonstrates the advantages of using a well-defined antigen to obtain both rapid onset of disease and a higher percentage of animals succumbing to the illness.

Animals↗

Architectural alteration of lymphatic tissue produced by extracorporeal thoracic duct filtration.

Removal of recirculating lymphocytes from the lymph of calves by extracorporeal thoracic duct filtration results in a state of immunounresponsiveness. Accompanying this is histological evidence of lymphocyte depletion from the lymph organs and structures of the body. Lymph nodes, spleen, hemolymph nodes, Peyer's patches, and thymus appear depleted of the recirculating small lymphocyte. We find this closed model of lymphocyte depletion effective and free of seyere problems with infections and physiological alterations as experienced in mechanical removal, extracorporeal irradiation, and open thoracic duct fistulas.

Animals↗

Effect of cyclophosphamide on in vitro phagocytosis of Staphylococcus aureus.

An increase in susceptibility to infection in an untoward effect common to nearly all immunosuppressive agents. The present investigation was designed to examine potential causes of this decreased resistance to disease. Rats were treated with low dosages of cyclophosphamide, and the effect of such therapy on the in vitro phagocytic capabilities of polymorphonuclear leukocytes was examined. Intracellular destruction of phagocytized bacteria was not significantly altered as a result of treatment. However, the ingestion of Staphylococcus aureus was significantly impaired in the presence of serum from treated animals. Enzymatic analyses for various hydrolytic enzymes associated with reticuloendothelial tissue were also undertaken. Decreased levels of acid phosphatase within alveolar tissue was the only significant change noted as a result of treatment. The reduced phagocytic powers and enzyme levels observed in this investigation offer a partial explanation for the increased susceptibility to disease after treatment with cyclophosphamide.

Acid Phosphatase↗

Selective elimination of the delayed-type hypersensitivity response by extracorporeal thoracic duct filtration.

Calves were sensitized to tuberculin and histoplasmin. The delayed-type hypersensitivity skin response to these antigens was produced and the diameter of induration measured. Repeated skin tests prior to filtration demonstrated that the amount of induration produced by these skin tests was closely reproducible. Histoplasmin or tuberculin-coated columns were then introduced into a closed circuit extracorporeal thoracic duct circulation. A significant (P is less than 0.01) reduction or ablation of the delayed-type hypersensitivity response was obtained to the antigen used to coat the column. In contrast, no significant reduction occurred in the skin test response to the other antigen. Repeated skin tests to both antigens after the cessation of filtration showed a gradual rise toward prefiltration levels in the skin test to the filtered antigen. The results of these experiments indicate that a selective population of T lymphocytes can be removed from an in vivo system. The removal of these cells can selectively reduce a delayed-type hypersensitivity skin test response to a particular antigen. These results are consistent with the hypothesis that a type of in vivo selective immunosuppression can be produced by antigen-coated columns when they are placed in an extracorporeal thoracic duct lymph circulation system.

Absorption↗

Lack of effect of azathioprine on phytohemagglutinin-induced lymphocyte transformation and established delayed cutaneous hypersensitivity.

The effect of experimental long-term azathioprine administration on pre-existing in vitro and in vivo manifestations of delayed hypersensitivity was examined. Adult ewes were administered 3 mg/kg/day azathioprine for periods of up to 28 days. Neither phytohemagglutinin (PHA)-induced nor tuberculin-induced lymphocyte transformation was affected. Similarly, pre-existing skin test positivity to tuberculin showed no observable change following drug therapy. These results agree with the majority of those involving clinical situations and indicate that immunosuppression with azathiprine cannot be effectively monitored by either the lymphocyte transformation response to PHA or by changes in the in vivo or in vitro manifestations of pre-existing delayed cutaneous hypersensitivity.

Animals↗

In vitro response of bovine thoracic duct lymphocyte to phytohaemagglutinin following adult thymectomy.

The effect of adult thymectomy on the thoracic duct lymphocyte population of yearling calves has been investigated. Four to 6 weeks after thymectomy animals showed significantly reduced thoracic duct lymphocyte concentrations when compared to non-thymectomized controls. In addition, phytohaemagglutinin responsiveness of thoracic duct lymphocytes, measured by (3H) thymidine uptake, was significantly decreased following adult thymectomy. However, this decreased response to PHA was not accompanied by a change in spontaneous isotope incorporation. It is concluded that adult thymectomy in the bovine probably leads to a reduction in the number of PHA responsive T cells in the thoracic duct lymph.

Animals↗

Serum prognostic indicators in experimental Bacteroides peritonitis.

Serum lysozyme and hemolytic complement (CH100) levels were measured in dogs with experimental Bacteroides peritonitis. The CH100 levels showed little change in surviving animals. Nonsurvivors showed a moderate decrease in complement levels shortly after contamination. Both surviving and nonsurviving animals showed a slight initial decrease in lysozyme levels shortly after contamination. In surviving dogs this was followed by an increase to normal levels. In nonsurvivors, levels continued to increase, reaching a threefold magnification just prior to death. As a result of antibiotic therapy, CH100 levels exhibited no major changes; however, dogs deprived of antibiotic showed noticeable and persistent increases in lysozyme levels while treated animals showed only a mild elevation in lysozyme levels. The changes in the level of serum lysozyme may be a good indicator of antibiotic efficacy and approaching death from Bacteroides peritonitis.

Animals↗