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Biomedical subjects

S Davis

Publications and source records attributed to S Davis.

At least 433 records · Page 24Linked to original sources
PubMed1982

Carcinoembryonic antigen in nonhuman primates.

Blood levels of carcinoembryonic antigen (CEA) have been measured in several nonhuman primate species. Only gorillas and chimpanzees were found to have significant elevations of CEA-like activity in their blood compared to the normal values of less than 2.5 ng/ml in humans. The average CEA level in 134 chimpanzees was 25.2 ng/ml (range, 4.2--95 ng/ml) and in 13 gorillas it was 32 ng/ml (range, 12.4--61.9 ng/ml). These levels were not related to sex. Blood levels repeatedly taken over a 1 1/2-year period remained relatively stable in both species. Analysis of parallelism of immunologic reactivity showed chimpanzee CEA to be similar to but not identical with human CEA. The molecular size of chimpanzee CEA was also similar to that of human CEA.

Animals↗
PubMed1982

Retention of carcinoembryonic antigen on Sephadex G-50 and acrylamide gel buffer-exchange columns.

We compared the degree of retention of carcinoembryonic antigen on two types of buffer-exchange columns, Sephadex G-50 and acrylamide gel. Both types retained trace amounts of the antigen applied in the form of a perchloric acid extract, as measured by its release into plasma samples subsequently processed through the same columns, Cross contamination, resulting in values falsely high by greater than 1 microgram/L, was observed when columns were re-used after processing plasma samples with carcinoembryonic antigen concentrations greater than 700 micrograms/L.

Blood Chemical Analysis↗
PubMed1981

Sideroblastic anemia associated wtih hairy cell leukemia.

A patient with leukemic reticuloendotheliosis ("hairy cell" leukemia) with sideroblastic anemia and an epinephrine-induced platelet-aggregation abnormality is presented. Immunologic membrane marker studies supported a B-lymphocyte origin of the hairy cells. It is hypothesized that a defect in the pluripotent marrow stem cell may be responsible for the hairy cell leukemia and for the intrinsic abnormalities in erythrocytes and platelets.

Aged↗
PubMed1981

Small-cell carcinoma of the lung--survival according to histologic subtype: a Veterans Administration Lung Group Study.

Six-hundred-twenty cases of small-cell carcinoma of the lung entered into the Veterans Administration Lung Group protocols 9-15 were retrospectively subdivided into histologic subtype, as proposed by the WHO (1977). Medium survival was greater for subtype No. 21 (lymphocyte-like) than for subtype No. 22 (intermediate) (17.2 vs. 12.6 weeks; P = .005). Patients with extensive disease survived longer with subtype No. 21 than subtype No. 22 (14.5 vs. 10.9 weeks; P = .026). However, no median survival difference was seen with limited disease. Survival for subtype 21 was greater than No. 22 (P = .016) for patients with poor initial performance status (IPS; Karnofsky 70 or less); for ambulatory patients (IPS 80-100) a survival advantage was seen for subtype No. 21 compared with No. 22, but did not quite reach statistical significance (P = .09). Survival in subtype No. 21 was better than in subtype No. 22 (24.3 vs. 14.7 weeks; P = .001) when no weight loss (less than 10 pounds over the six-month period prior to therapy) was documented. However, with weight loss (greater than 10 pounds) survival in each subtype was similar.

Body Weight↗
PubMed1981

An experimental model for treatment of mesothelioma.

A peritoneal mesothelioma was induced by asbestos in a hamster, and was established in serial transfer to new hosts by injection of peritoneal effusion containing tumor cells. Biologically and histopathologically, this tumor is similar to its human counterpart. Three drugs were tested for efficacy using this model. Survival time was used as the only parameter of response and was compared with survival time of controls. Survival time increased 25 to 50% after short regimens of doxorubicin or 5-fluorouracil. Survival time increased up to 308% after long-continued treatments with cyclophosphamide. No cures were achieved.

Animals↗
PubMed1981

Malignant interstitial cell carcinoma of the testis: report of two cases with steroid synthetic profiles, response to therapy, and review of the literature.

Two cases of malignant interstitial cell carcinoma of the testis are reported. The first patient had no evidence of a virilizing syndrome. Basal plasma testosterone (T) was decreased, whereas plasma luteinizing hormone, estrone (E1), and androstenedione were elevated. These findings were diagnostic of a defect in T secretion as a result of a partial 17-hydroxysteroid dehydrogenase deficiency as seen in male pseudohermaphroditism. In the second patient, showing gynecomastia and atrophic testis, endocrine studies revealed high plasma T and estradiol (E2); all measured delta 4 and delta 5 precursors of T were elevated resembling the pattern seen in virilizing adrenal carcinomas. Both patients were treated with radiotherapy without demonstrable effect. Chemotherapy--consisting of a combination of cis-platinum, vinblastine, and bleomycin; then cyclophosphamide, doxorubicin, and vincristine; and finally o,p'-DDD--was unsuccessful in reducing tumor bulk. Since malignant Leydig cell carcinomas are rare, this paper reviews the literature and makes recommendations concerning treatment.

17-Ketosteroids↗
PubMed1981

Evaluation of lingual artery hemodynamics in stroke patients using Doppler ultrasound.

Doppler blood flow studies were carried out on deep lingual arteries of young adults and stroke patients to see how the hemodynamics of this artery would be altered in the stroke group, who were selected on the basis of their having carotid atherosclerosis. The healthy controls exhibited a consistent and characteristic velocity pulse profile, which included a distinctive dichrotic notch and significant diastolic flow. The stroke group especially lacked these two critical parameters, and some exhibited amorphous flow patterns and cardiac arrhythmias. Implications of these findings in relationship to atherosclerosis are discussed.

Adolescent↗
PubMed1981

Androgen metabolism in male and female breast tissue.

Incubation studies have been carried out using normal breast tissue and breast tissue from patients with gynecomastia, mammary dysplasia and breast carcinoma to determine the pattern of androstenedione metabolism. All tissues formed estrone (E1) and testosterone (T) in all incubations. Estradiol (E2) was isolated in incubations of tissue from 1 of 6 patients with mammary dysplasia, 5 of 6 patients with gynecomastia and in all incubations with normal and carcinoma tissue. Estrone formation was lowest in mammary dysplasia and gynecomastia, and higher in apparently normal breast tissue. The greatest E1 formation was found in incubations with breast carcinoma tissue, although there was considerable variation within this tissue group. Estradiol formation was low in all tissues, with the highest conversion rates in carcinoma tissue. Testosterone formation in carcinoma tissue was greater than in mammary dysplasia or gynecomastia, but similar to apparently normal tissue. These results indicate that breast tissue from different pathological states varies in its capacity to aromatize androstenedione (A) to estrogenic products and to convert it to other androgens. They have also shown that the pattern of metabolism is distinctive for the nature of the pathological abnormality.

Adolescent↗
PubMed1981

Immunological and biochemical characteristics of acid citrate eluates from tumour cells: a major non-immunoglobulin component.

Using competitive double-antibody radioimmunoassays we have shown that immunoglobulin (especially IgA) can be recovered in pH 3.5, 0.12M acid citrate eluates of freshly excised CCH1 tumour-cell suspensions. Studies with 125I-labelled eluates indicate that such preparations exhibit a variable, but appreciable, degree of non-specific binding to unrelated syngeneic tumour and normal tissues. PAGE/SDS gel electrophoresis of the labelled eluates revealed the presence of a major non-immunoglobulin component of 33-36K dalton which could account in part for the non-specific binding observed. This component was also detected in similar eluates from cultured CCH1 tumour and in all other tumour-cell eluates examined to date. In contrast, preliminary data suggest that it is less prevalent in acid citrate eluates from normal tissue, with the exception of peritoneal-exudate cells. The possible origins, nature and significance of this non-immunoglobulin component are discussed.

Animals↗
PubMed1981

Hypoxanthine-guanine phosphoribosyltransferase activity in normal and leukaemic lymphocytes.

The levels of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) were determined in lymphocytes from normal people and patients with chronic lymphocytic leukaemia (CLL). The HGPRT level in the total lymphocyte population from patients with CLL was lower than that from normal subjects. The HGPRT activity was higher in normal non-T cells than normal T cells. The enzyme activity in CLL B cells was lower than in CLL T cells. The HGPRT level was higher in CLL T cells than in normal T cells; these data suggest CLL T cells differ biochemically from their normal counterparts.

Aged↗