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Biomedical subjects

A Griffin

Publications and source records attributed to A Griffin.

89 records · Page 5Linked to original sources
PubMed1985

Dynamics of collagen accumulation and polymorphism in murine Schistosoma japonicum.

The dynamics of hepatic collagen biosynthesis and degradation were studied in mice infected with Schistosoma japonicum. Hepatic fibrosis, the major clinical manifestation of disease, increased during acute infection (0-15 wk). The majority of proline incorporation into hydroxyproline, which was reflective of collagen synthesis, was found within hepatic egg granulomas. As the disease became chronic (20-30 wk) there was a decrease in collagen synthesis and a maintenance of total collagenolytic activity, which resulted in decreased accumulations of both total hepatic and granuloma-associated collagen. In addition to these quantitative decreases in extracellular collagen there was a qualitative change in the type of hepatic collagen synthesized. Early in infection, type I collagen was the predominant biosynthetic product, whereas late in infection type III collagen became the dominant isotype. A similar switch was seen in the substrate specificity of the constitutive collagenolytic activity, with decreasing type I activity and increasing type III activity as the disease progressed from acute (10 wk) to chronic (30 wk). These changes in the quantity and makeup of extracellular collagen may lead to amelioration of disease and potential reversibility of fibrosis.

Animals↗
PubMed1984

Prostaglandin production and platelet reactivity of small-diameter grafts.

This article examines the relationship of platelet deposition to thromboxane and prostacyclin (PGI2) production in arterial autografts (n = 8), para-anastomotic native artery (n = 40), nonseeded control (n = 6), and endothelial cell-seeded (n = 17) small-diameter Dacron grafts implanted in the carotid and femoral arteries of dogs. Platelet deposition was measured by a dual-isotope subtraction platelet-imaging technique that expresses platelet deposition as percent indium excess (%IE). PGI2 and thromboxane assays were performed with the use of an immunoreactive assay. The %IE in the nonseeded grafts was significantly higher than in the seeded prostheses (p less than 0.001). Arterial autografts accumulated significantly less platelets than did seeded grafts (p less than 0.05) or nonseeded grafts (p less than 0.001). The thromboxane A2 (TXA2) production in nonseeded grafts was significantly higher than in seeded grafts (p less than 0.001), arterial autografts (p less than 0.001), or in para-anastomotic native artery (p less than 0.001). The PGI2 production by the arterial autografts was significantly higher than by the nonseeded grafts (p less than 0.005), seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). The PGF1 alpha/TXB2 ratio was significantly higher in the arterial autografts when compared with the nonseeded grafts (p less than 0.001), endothelial cell-seeded grafts (p less than 0.001), or para-anastomotic native artery (p less than 0.025). We conclude that platelet deposition can be significantly decreased by endothelial cell seeding of small-diameter grafts. The transmural production of TXA2 by native arteries and prosthetic grafts may have an important influence on platelet deposition and patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Restraint stress-induced suppression of major histocompatibility complex class II expression by murine peritoneal macrophages.

The macrophage plays a central role in the development of immune responses. Macrophages take up and process antigen which is presented to antigen-responsive T lymphocytes in association with major histocompatibility complex class II (Ia) glycoproteins. We have investigated the effect of restraint stress on Ia expression by murine peritoneal macrophages. Stress resulted in a suppression of Ia expression which coincided with an increase in plasma corticosterone levels. In vitro experiments indicate that suppression of Ia expression can occur within 2 h after exposure to corticosterone. The suppression of this important aspect of macrophage function by stressors has important implications regarding the possible immunosuppressive effects of stress on the response of lymphocytes to antigens that depend on intact macrophage function.

Animals↗
PubMedDate not supplied

Holism in nursing: its meaning and value.

The term holism implies the integration of parts to achieve harmony. What can this ideal mean in a world which is fragmented and in a nursing context constrained by resources? Holism has some valuable applications for nursing and some warnings too.

Holistic Health↗