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Biomedical subjects

C R Ball

Publications and source records attributed to C R Ball.

At least 19 recordsLinked to original sources
PubMed1982

Insulin reversal of diabetes-induced inhibition of vascular contractility in the rat.

Contractures induced by 10(-9)-10(-4) M phenylephrine (PE) or 10-70 mM KCl were observed in aortas isolated from untreated and insulin-treated streptozotocin-diabetic rats. The experiments were conducted at 2-wk intervals for a 12-wk period after the induction of diabetes. Diabetes caused an average decrease of 58 and 60% in the K and PE contractures, respectively. Although the PE contractures in aortas from the insulin-treated diabetic animals (81%) were significantly greater than those in aortas from the untreated diabetic animals (60%), they were significantly less than those in control tissues (100%). Insulin treatment completely reversed the diabetes-induced decrease in the K contracture (102%). It appears that the diabetes-induced decreases in tension may result from an altered sensitivity of the tissues to KCl but not PE. Histological examination of the tissues revealed that the diminished contractions were not due to any detectable change in mural structure. The data indicate that diabetes-induced inhibition of the mechanisms involved in mediating the K contracture are completely reversible by insulin treatment, whereas those mediating the PE contracture are only partially reversible.

Animals↗
PubMed1981

Diet-induced atrial endothelial damage--a scanning electron-microscopic study.

A semipurified diet containing 28% fat (as lard), but no known atherogenic substances such as cholesterol, was fed to a group of Swiss stock mice. A group of similar mice was fed laboratory chow as controls. Within six weeks of diet feeding, experimental mice developed atrial thrombosis. In scattered areas of atria where thrombi were not present, the scanning electron microscope showed an endothelial response to the high-fat diet in the form of holes and crater-like lesions. In extreme cases, a whole endothelial cell might be almost totally destroyed. Clusters of leucocytes mixed with platelets and fibrin attached to the larger holes, suggesting the initiating mechanism of thrombogenesis, were also observed.

Animals↗
PubMed1979

Observations on the results of specific histochemical techniques and empirical staining methods on several tissue/organ types using a variety of fixing fluids.

Several histotechniques (Harris hematoxylin and alcoholic eosin, Gomori's reticulum method, Verhoeff's elastic stain; Gomori's trichrome, Mallory's aniline blue collagen stain and the Cameron and Steele method) were each used with a number of fixatives (Lavdowsky's chromic acid, Karnovsky's glutaraldehyde/paraformaldehyde, neutral buffered formalin, Lavdowsky's formalinacetic acid-alcohol, Zenker's and Helley's). Lavdowsky's chromic acid fixative provided superior results as compared to the other fixing fluids and its use was critical with respect to the trichrome or connective tissue staining procedures. The Cameron and Steele modification used with Lavdowsky's chromic acid fixative gave the best differentiation of tissue types and was also the most reproducible.

Aging↗
PubMed1975

Transplantable colon tumors as chemotherapy screening models.

A series of transplantable murine colon tumors have been developed from primary tumors induced by dimethylhydrazine. They are moderately- to well-differentiated adenocarcinomas which retain their histologic appearance and growth characteristics through successive transplant generations. The sensitivity of two tumor lines to 11 standard drugs is reported and some correlation shown with the sensitivity of human colorectal tumors to the same drugs. Therapeutic indices are low and each tumor has an individual pattern of sensitivity. The models have potential as secondary drug screening systems and for investigation of factors affecting drug sensitivity.

Adenocarcinoma, Mucinous↗
PubMed1975

Transplantation of adenocarcinomas of the colon in mice.

1, 2-Dimethylhydrazine treatment induced multiple colon tumors in 100% of NMRI mice. Many of these tumors were transplanted and yielded five serially transplantable tumor lines. These subcutaneously transplanted neoplasms were all adenocarcinomas varying in degree of differentiation and mucin production. No evidence of dedifferentiation or change in growth rate has been seen in up to six transplant generations. These tumor lines appeared to provide relatively stable, well-differentiated models for colorectal cancer.

Adenocarcinoma↗