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Biomedical subjects

R C Brown

Publications and source records attributed to R C Brown.

At least 253 records · Page 14Linked to original sources

Leiomyoma of vesicovaginal septum causing urinary retention.

A case of leiomyoma of the vesicovaginal septum causing acute urinary retention and an unusual radiographic filling defect in the flood of the bladder is presented. This is a rare lesion which can be the source of confusion. It has similar microscopic appearance to lesions which the patient had previously in the esophagus and stomach, left labia, and the uterus. Microscopically, all of the tumors were benign.

Acute Disease↗

Analysis of tumor-associated alkyldiacylglycerols and other lipids during radiation-induced thymic leukemogenesis.

Lipid composition of thymuses investigated during the development of thymic leukemogenesis induced by exposing C57BL/6J mice to gamma radiation led to the following conclusions. 1. Alkyldiacylglycerols, a class of lipids that are generally elevated in most neoplastic tissues, occurred only in small quantities (less than 1% of the total lipids) in the thymuses of both control and irradiated mice. However, we found a 3- to 8-fold increase in this fraction in thymic tumors of mice at 5 mo after irradiation when compared to controls of similar age. However, the small quantity of this lipid class in thymic leukemia and the fact that similar levels were found in some samples of involuted thymuses of mice 3 days after irradiation, suggests to us that the level of alkyldiacylglycerols is not sufficiently specific or sensitive for detecting early stages of thymic leukemogenesis. 2. Thymuses 3 days after irradiation and leukemic thymuses contain 2- to 3-fold greater quantities of cholesterol esters than control thymuses. No major differences were found in the distribution of acyl moieties in the cholesterol esters of the various thymus samples from the same aged mice except that in thymic tumors the quantity of 18:1 esters was increased by about 25% over that of the controls. The apparent lack of specificity of increased cholesterol esters for neoplasia indicates that its measurement would not provide a suitable indicator of early neoplastic transformation. 3. Acyl composition of the triacylglycerols of thymuses revealed an increase in the 18:1 and a decrease in the 18:2 acids at 3 days after irradiation when compared to the same aged controls. However, thymic tumors occurring at 5 mo after irradiation contained less 14:0, 16:0, and 16:1 acids and increased amounts of 18:1 and 18:2 acids esterified as triacylglycerols compared to controls. The fatty acid distribution in the phospholipid fraction of thymuses was not altered by the appearance of leukemia.

Animals↗

Evaluation of irradiation-plus-urethan-induced murine leukemia virus "release" using a new method for quantitation of oncornaviruses in tissues.

The quantity of C-type RNA tumor viruses in homogenate-sonicates of thymus-bone marrow tissues of C57BL/6J and RFM/Un mice 10 days after irradiation (X-rays or gamma-rays)-plus-urethan treatments is no greater than that in thymus-bone marrow homogenates from nontreated control mice. These results indicate that the leukemogenic activity, shown to be present in such thymus-bone marrow homogenates at this time after irradiation-plus-urethan treatment, is not due to change in quantity of C-type viruses as has been proposed. Virus quantity in tissues was evaluated by a new procedure that includes use of a microchamber with the sides situated on rotor radii so as to produce a uniform virus-containing sediment of tissue homogenate-sonicate that is evaluated by electron microscopic examination of this sections cut perpendicular to the membrane surface. Samples containing as little as 105 to 106 viruses can be relatively easily counted. Semipurified or purified viruses can also be counted after mixing with a tissue homogenate-bovine serum albumin diluent.

Animals↗

Methyldopa liver damage.

Twenty patients are described in whom liver damage appeared to be directly related to the administration of methyldopa. Sixteen had hepatitic syndromes from which they recovered on stopping methyldopa; four of these patients had recurrences of jaundice after a second course of the drug. Features suggestive of active chronic hepatitis were found in two patients. There were two deaths attributed to methyldopa, one of these being in a patient with pre-existing undiagnosed macronodular cirrhosis.

Adult↗