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Biomedical subjects

R K Wagner

Publications and source records attributed to R K Wagner.

At least 37 records · Page 2Linked to original sources
PubMed1980

quality control in steroid hormone receptor analyses.

In this paper, standards for steroid hormone receptor determinations in cancer tissue have been outlined. Standardization of methods for receptor extraction and receptor assay are equally important; and it is a condition sine qua non, if comparable receptor values between different centers for multilocal studies are required. Immediate and proper cooling of the tissue samples after removal, homogenization at the temperatures of the liquid nitrogen (as well as the presence of a sulfhydryl-protecting agent in the extraction medium), and the use of a simple, reproducible assay procedure are most important. As a standard procedure for ER- and PR-assays, the charcoal adsorption method combined with a scatchard-plot has been suggested. Reference procedures, like protein with DNA-assays, must also be standardized. Quality control experiments can be performed with lyophylized calf uterus homogenates. Additional determination of the nuclear estradiol in the high-speed sediments by radioimmunoassay is highly recommended.

Adult↗
PubMed1980

The histopathological evaluation of human breast cancers in correlation with estrogen receptor values.

A detailed histopathological review of 140 primary breast cancers analyzed for estrogen receptor protein (ERP) was carried out and a variety of morphological features correlated with ERP results. ERP in cytosols was incubated with [3H]estradiol in the presence and absence of cold estradiol and assayed by agargel electrophoresis. Tumors binding greater than 10 fmol estradiol/mg tissue protein were classified as receptor-positive. Seventy-seven percent of the 116 infiltrating duct carcinomas were ERP-positive. The well-differentiated tumors of this group had a higher incidence of ERP-positivity than the poorly differentiated ones. The ten predominantly or exclusively intraductal carcinomas and the seven medullary tumors were less frequently positive than the main group of infiltrating ductal cancers. The three colloid, two tubular, and two lobular carcinomas in this series were all ERP-positive. When receptor measurements are evaluated, consideration should be given to the degree of differentiation and the histological type of tumor, in addition to other factors known to influence receptor levels such as menopausal status and seasonal variation.

Adenocarcinoma, Mucinous↗
PubMed1978

The occurrence of steroid-free, "activated" estrogen receptor in target cell nuclei.

New techniques for the adrenalectomy of pigs and for the isolation of pig uterus nuclei are described. The isolated nuclei were analysed for their content of estradiol and of estradiol receptor. The concentration of the latter exceeded that of the hormone in extracts of uterine nuclei from ovariectomized pigs by ratios of 1.8--10.3. Substantial amounts of both monomer and "activated" dimer receptor but no estradiol at all were extracted from uterine nuclei of ovariectomized/adrenalectomized pigs. The mechanism of action of steroid hormones is discussed on the basis of these results.

Adrenal Cortex↗
PubMed1976

Ovarian-independent fluctuations of estradiol receptor levels in mammalian tissues.

Three types of periodic fluctuation in tissue concentrations of estradiol receptor protein have been observed. A seasonal variation is described in the uteri of 12-16-week-old calves and of ovariectomized pigs, and in mammary tumor tissue obtained from postmenopausal women. A circadian rhythm has been demonstrated in uteri of ovariectomized rats. An irregular periodic fluctuation has been found in uteri of ovariectomized and of ovariectomized/hypophysectomized rats, with the period varying from 9 to 15 days. These observations establish that a substantial turnover of receptor occurs in the absence of hormone and that 'normal' baseline values of receptor concentration do not exist.

Animals↗
PubMed1976

Oestradiol- and dihydrotestosterone receptors in normal and neoplastic human mammary tissue.

Human mammary gland and tumours derived from it contain individual receptors for oestradiol) and for dihydrotestosterone. Analysis of 97 mammary cancers by agargel electrophoresis revealed a widely varying pattern of simultaneous occurrence in different concentration ratios (46), sole presence of oestradiol receptor (23) or dihydrotestosterone receptor (8) and absence of both receptors (18). The relevance of the results is discussed and the need for an extensive cooperative study is emphasized.

Adult↗
PubMedDate not supplied

Cost consequences of elimination of the routine group B streptococcus culture at a teaching hospital.

OBJECTIVE: To evaluate the cost consequence of the elimination of routine Group B streptococcus (GBS) cultures in pregnancy utilizing risk factor assessment management recommendations of the Center for Disease Control. METHODS: This retrospective study cohort population included all delivering patients from June 1, 1996, to May 31, 1997, managed by the Morbidity Mortality Weekly Report (MMWR) guidelines May 31, 1996, for GBS in pregnancy compared to the previous 29 months cohort from January 1, 1994, to May 31, 1996, managed with routine GBS cultures done at 35-37 weeks. RESULTS: Of the 7,681 culture management control cohort patients, there were four neonates with culture-positive GBS sepsis (1/1,900). The cost for detection of a single positive culture in an affected neonate was $8,627 ($34,509/4) and there were 2,875 personnel hours expended. In contrast, of the 2,011 patients in the risk factor management cohort, there were two cases of neonatal GBS sepsis ($111,005). The cost for detection of a positive culture in an affected neonate was $1,579 ($3,159/2) and there were 263 personnel hours expended in the risk factor management group. In spite of these significant laboratory savings, we noted a concurrent increase in the total cost in the newborn nursery for septic work-ups and treatment from $2.4 million to $3.1 million. CONCLUSION: Risk assessment management of GBS provided a savings of both money ($7,048/positive neonatal culture) and laboratory time (586 personnel hours/positive neonatal culture). However, these savings were more than offset by cost increases occurring in the newborn nursery ($400,000), demonstrating the necessity of practice patterns to undergo concurrent evaluation to verify cost savings and prevent shifting of expenses.

Cohort Studies↗
PubMedDate not supplied

Effects of lipopolysaccharide on interleukin-6 production in perfused human placental cotyledons.

OBJECTIVE: To determine if lipopolysaccharide (LPS) alters production of interleukin-6 (IL-6) or vascular tone in perfused placental cotyledons. METHODS: Control and study cotyledons from nine placentas were perfused for 3 h. Study cotyledons received LPS in concentrations of 0.01 mcg/ml (n = 3), 0.1 mcg/ml (n = 3), or 1.0 mcg/ml (n = 3). Effluents were collected at 30, 60, 120, and 180 min following infusion with LPS. IL-6 concentrations were measured by enzyme-linked immunosorbant assay. Perfusion pressures were recorded at 10-min intervals. Data were analyzed using ANOVA for repeated measures. RESULTS: IL-6 production significantly increased over time in both the study and control cotyledons (P = 0.002). LPS treatment did not affect IL-6 production (P = 0.85) and there were no observable dose effects (P = 0.13). Perfusion pressures did not differ (P = 0.16). CONCLUSIONS: The isolated perfused placental cotyledon produces IL-6 and concentrations increase over time. LPS does not alter production of IL-6 or fetoplacental vascular tone.

Dose-Response Relationship, Drug↗