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Biomedical subjects

D W Scott

Publications and source records attributed to D W Scott.

At least 217 records · Page 12Linked to original sources
PubMed1980

A new approach for evaluating risk factors in coronary artery disease: a study of lipid concentrations and severity of disease in 1847 males.

Using recently developed statistical techniques, we estimated joint probability density functions for plasma cholesterol and plasma triglyceride concentrations in 12 subgroups of 1847 males with angiographically demonstrated coronary artery disease. The subjects were grouped by patterns of age, history of hypertension, history of smoking and severity of disease. From the estimated joint probability density functions, we determined the way in which the risk of severe vs moderate coronary artery disease varied with the joint variation of plasma lipids for given combinations of the other risk factors. The patterns of risk that we found are evidence of the complicated way in which the relationship between plasma lipids and the severity of coronary artery disease is affected by other risk factors.

Adolescent↗
PubMed1980

The comparative pathology of non-viral bullous skin diseases in domestic animals.

In a review of non-viral bullous skin diseases of domestic animals and a 4-year study of cases presented to the New York State College of Veterinary Medicine, we found 15 diseases: pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, bullous pemphigoid, systemic lupus erythematosus, dermatitis herpetiformis, toxic epidermal necrolysis, drug eruption, epidermolysis bullosa, epidermolysis bullosa simplex, familial acantholysis, bovine congenital porphyria, impetigo and subcorneal pustular dermatosis. The 15 diseases were placed in five categories: autoimmune, immune-mediated, hereditary, bacterial and idiopathic. A histologic classification of these disorders based on the site of blister formation and other important clinicopathologic, histologic and immunopathologic findings was developed.

Acantholysis↗
PubMed1980

Addition of potassium supplements to milk-based tube feeds.

For an intragastric tube feeding regimen to meet the complete nutritional needs of the individual patient, it will often require the addition of extra potassium, to commercially available feeds. Potassium supplements in a suitable form can be added to milk-based feeds to concentrations of at least 175 mmol K+ per litre without any apparent coagulation. Supplements in the form of effervescent preparations are not suitable as the citric-acid content can cause severe coagulation of the feed.

Animals↗
PubMed1980

Cellular events in tolerance. VIII. Analysis of the proliferative capacity of antigen-binding cells isolated from normal or tolerant spleens.

Previous studies in our laboratory have demonstrated that hapten-binding lymphocytes (ABC) can be isolated from the spleens of mice rendered tolerant to the hapten. These cells are reduced in PFC precursor frequency when stimulated with either specific antigen or mitogen (Reference 6). In the present studies, we have combined antigen-specific cell isolation and an analysis of thymidine uptake by purified B cells to determine whether hapten-binding B cells in tolerant mice can be stimulated to proliferate in response to specific antigen. Compared with normal ABC, "tolerant" ABC showed a significantly reduced thymidine incorporation responsiveness in vitro. This suggests that unresponsiveness in adult mice can result in an impairment of clonal proliferation. Hence, these "tolerant" ABC appear to be functionally though not physically, deleted.

Animals↗
PubMed1980

Functional differentiation of T-cell precursors. II. Recovery of immunocompetence in lethally irradiated bone marrow reconstituted mice.

The recovery of T-cell immunocompetence in irradiated mice repopulated with syngeneic bone marrow cells has been studied. Both thymocytes and spleen cells from irradiated recipients were tested for Concanavalin A mitogen responsiveness, mixed lymphocyte reactivity, generation of trinitrophenyl-hapten-modified self cytotoxicity and helper cell carrier function. Responsiveness in the thymus reaches peak levels between 3-5 wk after marrow transfer, while splenic reactivity peaks at least 2-3 wk later, presumably a reflection of emigration from the thymus to peripheral lymphoid organs. Most T-cell functions reappeared at approximately the same time, though Con A responsiveness appeared first and helper activity for indirect IgG formation last. Since we have previously demonstrated that helper cell precursors in the marrow can be rendered tolerant, these studies will now allow definition of specificity in other T-cell subsets.

Animals↗
PubMed1980

Creation and properties of histocompatibility antigen-cell conjugates. II. Antibody tolerance after treatment with donor histocompatibility antigen chemically coupled to recipient spleen cells.

Histocompatibility (HC) antigens from Lewis (RT-11) and ACI (RT-1a) rats were solubilized and their tolerogenic potential alone or when conjugated to cellular carriers was investigated. The tolerogenic carrier potential of whole cells, crude membranes, and deoxycholate (DOC)-solubilized membranes was first determined by conjugating trinitrophenyl (TNP) groups to them and measuring their ability to prevent an anti-TNP plaque-forming cell response in rats after immunogenic challenge. Since whole lymphoid cells proved to be most effective in this system, DOC-solubilized allogeneic histocompatibility antigens were coupled to syngeneic lymphocytes, using carbodiimide cross-linking. Animals pretreated with this conjugate produced no alloantibody upon challenge with allogeneic cells. These results suggest that tolerance to allogeneic histocompatibility antigen can be produced by association of alloantigens on a tolerogenic self-carrier.

Animals↗
PubMed1980

Role of self carriers in the immune response and tolerance. VI. Induction and reversal of TNP-modified self unresponsiveness in vitro.

The involvement of T-suppressor cells in hapten-modified self unresponsiveness induced in vivo is well established. However, TNP-modified syngeneic spleen cells (TNP-SC) can block the anti-TNP PFC response of normal or nude spleen cells to TNP-immunogen in vitro, an effect that is apparently T cell-independent. In this study, we have used a 2-stage culture system in which both the induction of tolerance by irradiated syngeneic TNP-SC and the subsequent challenge with TNP-immunogen take place in vitro to dissect the cellular events that lead to unresponsiveness. Our results show that not only are spleen cells precultured with TNP-SC tolerant to challenge, but that these cells are able to specifically suppress the response of freshly prepared normal spleen cells to the T-independent antigens TNP-POL or TNP-LPS. Irradiation of the precultured cells abrogates the suppressor activity and rules out hapten carryover as the mechanism of suppression. Suppressor cells were able to inhibit the response of anti-Ba theta and C-treated spleen cells, suggesting that suppressor function is directed toward the B cell and/or accessory cells. Anti-Ba theta and C treatment of spleen cells before preculture with TNP-SC prevented the induction of both tolerance and suppression. Nylon wool-enriched T cells, on the other hand, could generate suppressor cells in response to TNP-SC. These results demonstrate that, like the in vivo situation, T cells are involved in the generation of this form of B cell tolerance in vitro. Implications relevant to the mechanisms of tolerance induction are discussed.

Animals↗
PubMed1979

Some effects of short-term methylprednisolone therapy in normal cats.

Four normal cats were treated weekly for 4 weeks with repositol methylprednisolone. Hemograms, serum chemistry panels, urinalyses, 24 hour water consumption, physical and constitutional parameters, and blood cortisol responses to ACTH stimulation were monitored before and during a day were done prior to steroid therapy on each cat. Clinicopathologic abnormalities induced by steroid therapy were, on the whole, inconsistent and minor. The most important findings were: (1) marked steroid-induced suppression of blood cortisol responses to ACTH, and (2) a circadian rhythm of blood cortisol production that was opposite to that of humans and dogs.

Adrenocorticotropic Hormone↗
PubMed1979

Role of self carriers in the immune response and tolerance. IV. Active T cell suppression in the maintenance of B cell tolerance to a "T-independent" antigen.

Previous studies indicated that T cells are required for tolerance induction by hapten-modified syngeneic spleen cells (TNP-SC) in vivo. The role of T cells in the maintenance of this unresponsive state has been examined herein. By three criteria--limiting dilution precursor analysis, removal of T cells by anti-Thy-1 + C, and direct mixing experiments--we show that T cells are required for the continued suppression of the B cell response to the T-independent antigen, TNP-POL. Suppressor cells can also be induced by TNP-teratoma cells, which lack detectable H-2 antigens. Both anti-Ly-1 + C and anti-Ly-2 + C treatment reversed suppression induced by TNP-SC. These results demonstrate that normal B cell reactivity is present in the spleens of mice rendered tolerant by haptenated self, but that Ly-1,2,3 or Ly-1 + Ly-2,3 suppressor T cells prevent their responsiveness.

Animals↗
PubMed1979

Dermatohistopathologic changes in bovine congenital porphyria.

Congenital porphyria was diagnosed in 4 crossbred cattle. All had pink-brown discoloration of the teeth and amber colored urine, which fluoresced bright orange with exposure to ultraviolet light. Elevated levels of uroporphyrin and coproporphyrin were found in the urine of all 4 cattle. Skin biopsies taken from 2 of the cattle revealed subepidermal blister formation and thickening of upper dermal blood vessel walls with deposition of a PAS-positive, hyaline-like material.

Animals↗
PubMed1979

Lymphoreticular neoplasia in a dog resembling malignant histiocytosis (histiocytic medullary reticulosis) in man.

Malignant histiocytosis was diagnosed in a 4-year-old-dog. Major clinicopathologic findings included multiple cutaneous tumors, peripheral lymphadenopathy, hepatomegaly, lytic bone lesions, anemia, thrombocytopenia, and monoclonal IgA gammopathy. Pathologic findings included multi-systemic infiltration of erythrophagocytic malignant histiocytes. Chemotherapy was unsuccessful.

Animals↗