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Biomedical subjects

S C Stevens

Publications and source records attributed to S C Stevens.

9 recordsLinked to original sources

Pelvic fractures diagnosed by bone scintigraphy in patients with normal radiographs after a fall.

When elderly patients present with pain and difficulty walking after a fall, hip fracture is often suspected. If the x ray shows no abnormality early mobilisation is encouraged. When these patients continue to experience pain and are unable to walk, bone scintigraphy may reveal pelvic fractures. We present three illustrative cases and a retrospective review of 50 consecutive patients with pelvic fractures diagnosed by bone scintigraphy.

Accidental Falls↗

Human chorionic gonadotropin and malignant mesothelioma.

A 56-year-old male presented with ascites and gynecomastia. Laparoscopy demonstrated peritoneal tumors which were biopsied. Conventional histology and electron microscopy revealed the tumor to be a malignant mesothelioma. The ascitic fluid and tumor cell lysate, but not serum, contained hCG by specific assay, and the immunoreactive hCG had characteristics similar to purified hCG in filtration on Sephadex G-100. Malignant mesothelioma is a tumor which may be associated with elevated hCG concentrations. Demonstration of hCG in ascitic fluid should suggest the presence of neoplasm.

Ascitic Fluid↗

Estrogen receptor assay of mammary carcinomas. Effects of testosterone-estradiol-binding globulin (TeBG) and serum estradiol-17 beta.

To test the hypothesis that the serum sex steroid-binding protein, TeBG, might contaminate mammary carcinoma cytosols sufficiently to interfere with assay for estrogen receptor (ER), studies of tritiated estradiol-17 beta (3H-E2) binding were done following saturation with steroid hormones or after heat treatment of cytosol. Cytosols with appreciable 3H-E2 binding consistently showed a high degree of saturability with nonradioactive E2 and diethylstilbestrol (DES), and much less saturability with 5 alpha-dihydrotestosterone (DHT). Furthermore, they manifested heat-lability of 3H-E2 binding. These characteristics indicated that little, if any, TeBG was being detected in most cytosols, and that the amounts of TeBG present were not sufficient to interfere with the ER assay. Study of the relationship between serum E2 concentration at time of removal of the carcinoma and results of ER assay confirmed the need to interpret negative ER assays obtained for premenopausal women cautiously when serum E2 levels exceed approximately 300 pg/ml.

Adult↗

Estrogen receptor assay of carcinomas of the breast by a simplified dextran--charcoal method.

Carcinomas of the breast from 352 women were assayed for binding of tritiated estradiol by tumor cytosol with dextran--charcoal adsorption, saturation analysis, and two-point Scatchard plots; the level of saturable binding defined a cytosol as positive or negative for estrogen receptor. Valid assays were obtained on specimens as small as 120 mg. Assays of replicate samples of a cytosol were more reproducible than assays of replicate samples of the tumor itself. Occasional disparity of results between a primary mammary carcinoma and its axillary metastases could be related to differences in tumor cellularity. Saturable binding consistent with the presence of estrogen receptor was found in 59% of 305 primary carcinomas and in 57% of 47 metastatic or recurrent carcinomas. There was a significant negative correlation between the patient's age and saturable estrogen binding in the tumor. Serum estradiol levels of less than 250 pg/ml appeared to have a negligible effect on estrogen receptor content. A small subgroup of high-binding carcinomas had high dissociation constants, but the significance of this observation is not clear.

Age Factors↗

S-phase fractions of breast carcinomas. Relationships to morphology, estrogen and progesterone receptors, and early recurrence.

Analysis of the S-phase fractions (SPF) measured by in vitro thymidine labeling, morphological appearances, and estrogen receptor (ER) assays of primary invasive breast carcinomas demonstrated several interrelationships. Lobular, mucinous, tubular, and adenocystic carcinomas consistently had low SPF and were usually positive for ER. The same was true for the carcinomas of no special histologic type [the not otherwise specified (NOS) group of E. R. Fisher including "infiltrating ductal" and undifferentiated carcinomas] with minimal anaplasia. Medullary, atypical medullary, and morphologically unclassifiable carcinomas with marked nuclear anaplasia nearly always had high SPF and were usually negative for ER. High SPF was associated with advanced stages of carcinoma initially or with early recurrence following mastectomy.

Anaplasia↗

Low incidence of estrogen receptor in breast carcinomas with rapid rates of cellular replication.

The results of assay for estrogen receptor (ER) in the tumor cytosol and thymidine labeling indices (TLI) of 63 primary invasive carcinomas of the breast were analyzed. The ER assay was performed by using dextran-charcoal to adsorb unbound tritiated estradiol-17beta (E2) in cytosol. The TLI was measured as the number per hundred of neoplastic cell nuclei labeled by tritiated thymidine. A significant association between low TLI and presence of ER was found. Wereas all 19 tumors with TLI less than 2.5 contained ER in the primary lesion or in axillary metastases and ER was found in 25 of 30 tumors with TLI between 2.5 and 10, only 4 of 14 tumors with TLI greater 10 contained ER (p less than 0.001). TLI and saturable binding of E2 were significantly negatively correlated (r=-0.436,P. less than 0.001). It is concluded that dedifferentiation in breast carcinomas is associated with both high TLI and absence of ER, and suggested that the carcinomas with the most rapid proliferative rates will include the highest proportion of tumors unresponsive to hormonal therapy.

Adult↗