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Biomedical subjects

R P Davis

Publications and source records attributed to R P Davis.

At least 37 records · Page 2Linked to original sources
PubMed1984

Isolation and characterization of a novel thermophilic, freshwater methanogen.

A novel thermophilic, coccoid methanogen isolated from nonthermal freshwater sediments is described. Hydrogen plus carbon dioxide and formate were substrates for methanogenesis, and methane production was stimulated by yeast extract, Casamino Acids, and tryptose. Growth also occurred autotrophically. Elevated levels of sodium chloride were not required for maximum growth and were inhibitory above 2%. The minimum doubling time occurred at 57 degrees C, and the upper and lower limits for methane production were 62 and 26 degrees C, respectively. The optimum pH for growth was between 7.0 and 7.5. Inhibitory antibiotics included metronidazole, anisomycin, chloramphenicol, and lasalocid. Colonies were circular, dark yellow, shiny, and convex with entire edges. Cells were 1 to 2.5 mum in diameter, nonmotile, occurring singly or in pairs, and fimbriated. Cells were lysed by pronase or trypsin digestion, glass-distilled water, and 1% sodium dodecyl sulfate. Electron micrographs of thin sections showed a monolayered cell wall ca. 20 nm thick. The DNA base ratio was 49.2 mol% guanine plus cytosine. The whole cell protein pattern differed from that of other named coccoid methanogens.

Journal Article↗
PubMed1984

Management of solitary nonparasitic liver cyst.

Solitary nonparasitic liver cysts are clinically rare and mostly nonsymptomatic. Occasionally, cases present with symptoms mainly because of the presence of a large cyst. In this report, the clinical features, diagnostic modalities, and current management of such cysts are described.

Cysts↗
PubMed1983

Gastrointestinal lipomas.

We reviewed 15 years of experience with gastrointestinal (GI) lipomas at our institution. A series of eight patients was included, six of whom had lipomas in the colon and two, in the stomach. All eight patients were symptomatic. The diagnosis was not made preoperatively in seven cases, which accounted for surgical intervention in these patients. Colonoscopy was helpful in the diagnosis and treatment of the eighth patient. Advances in the diagnosis and treatment of GI lipomas include the use of computed tomographic scanning and colonoscopy.

Adult↗
PubMed1979

Experience with lobular carcinoma of the breast. Emphasis on recent aspects of management.

A total of 105 patients with lobular carcinoma of the breast were seen at two hospitals between 1966 and 1978. Mammography was found to be of limited value in the preoperative assessment of these patients. As reported by others, there was a high incidence of bilateral lobular neoplasia. In the patients with lobular carcinoma in situ for whom follow-up data were available, all were alive and well. In contrast to this, infiltrating lobular carcinoma was found to be as malignant a lesion as any other infiltrating breast cancer regardless of the operative procedure performed. These latter tumors were found to bind substantial levels of estrogen receptor proteins. From the information gained, it is suggested that early hormonal manipulation and/or chemotherapy may be advantageous in the patient with recurrent infiltrating lobular carcinoma in particular.

Adult↗
PubMed1977

The fungal flora of loganberries in relation to storage and spoilage.

Botrytis cinerea, Cladosporium spp., Penicillium spp., Aureobasidium pullulans, Mucor mucedo, Phoma state of Didymella applanata, Cryptococcus laurentii var. laurentii, C. albidus var. albidus, Candida sake and Sporobolomyces roseus were consistently present on freshly harvested loganberries. Botrytis cinerea was the main spoilage organism with Mucor mucedo of minor importance. The importance of benomyl-resistant strains of B. cinerea is discussed.

Ascomycota↗
PubMed1976

Scleroderma of the colon with obstruction: report of a case.

A case of a patient who had colonic obstruction caused by scleroderma is described. The obstruction initially was treated by means of a colostomy, and later subtotal colectomy was carried out. This is the fifth report of a patient with symptomatic colonic scleroderma successfully treated by colonic resection. A review of colonic scleroderma is included.

Adult↗
PubMed1975

Vagotomy and double pyloroplasty for peptic ulcer.

Seventy patients with peptic ulcers (55 duodenal and 15 gastric) were treated by truncal vagotomy and doulbe pyloroplasty during the past four years. Clinical and experimental data as presented lead us to believe that transecting the pylorus twice produces an incontinent pyloric sphincter and a larger gastric outlet than is found in other methods of pyloroplasty. This decreases gastric stasis and has led to a lower ulcer recurrence rate (1.5%). In addition the untoward postoperative sequelae are minimal. The 70 patients treated (for the most pare consecutive cases) exhibited the usual complications of peptic ulcer disease. Thirty-three had intractable pain, 23 bleeding (15 massive), 13 obstruction, and one acute perforation. There were no operative or postoperative deaths and the only serious postoperative complication was unrelated to the double pyloroplasty. During the followup period four patients have died of unrelated diseases. Of the remaining 66 patients one developed a probable recurrent peptic ulcer which has responded to medical management. Four patients have intermittent dumping, three have mild diarrhea and one has failed to gain weight, Constipation and weight gain are more common complaints. It would appear that vagotomy with double pyloroplasty is a safe and effective operation for peptic ulcers and that further clinical trials are warranted.

Humans↗
PubMed1975

The metabolism and binding properties of 3H-aldosterone in plasma and its sex dependence in adrenalectomized rats.

The rates of clearance of plasma 3-H radioactivitivity following intravenous injection of 3-H aldosterone was demonstrated to be sex-dependent in adrenalectomized rats. The perchantage plasma radioactivity which is CH-2CL-2extractable is greater in female than in male rats from 5 min to 90 min postinjection; however the quantities of CH2-CL2-extractable label are not significantly different until 60 min postinjection. The quantities of nonextractable, water-soluble metabolites of adosterone (NEPD), which are markedly greater in the plasma of males, reach peak levels 30 min after injections of aldosterone, during the latent period of the hormone.N females, these polar metabolites (NEPD)are rapidly cleared from the blood. The quantities of 3-H-radioactivity associated with the plasma binding proteins are similar in both males and females. The unbound levels of aldosterone and its metabolities are significantly greater in the plasma of males. These findings indicate that the sex hormones may influence not only the metabolism of aldosterone in rats, but also the plasma levels of unmetabolized aldosterone and its metabolites.

Adrenal Glands↗