Search PubMed⌕ Search

Biomedical subjects

S D Wilson

Publications and source records attributed to S D Wilson.

103 records · Page 6Linked to original sources
PubMedDate not supplied

Diminished expression of the alpha 5 beta 1 integrin (fibronectin receptor) by invasive clones of a human follicular thyroid cancer cell line.

Altered adhesion plaques have been observed in transformed cell lines and are associated with enhanced metastatic potential. The prototypical adhesion plaque is formed by alpha 5 beta 1 fibronectin receptors (FnRs) interacting with the cellular actin network. We have found differences in the actin networks of noninvasive (FTC-133) and invasive (FTC-236, FTC-238) clones of a human follicular thyroid cancer cell line. Furthermore, thyroid-stimulating hormone (TSH) induces stress fibers in FTC-133. In order to investigate differences in adhesion plaques, expression of fibronectin (FN) and its receptor by these cells was analyzed. For these studies FTC-133, FTC-236, and FTC-238 were cultured in serum-depleted DME-H21 medium for 24 hours before the addition of TSH 30 mU/ml. No quantitative differences were noted in FN expression on Western blot in either the conditioned medium or cellular extracts. Western blots and immunohistochemical studies indicated that TSH induced secretion of FN only in FTC-133. Flow cytometry with an alpha 5 antibody demonstrated a 52% and 45% reduction (p < 0.01) in expression of FnR by FTC-236 and FTC-238, respectively, compared to FTC-133; this finding was supported by immunohistochemistry results. TSH treatment did not alter FnR expression. From these studies, we conclude that invasive clones of FTC decrease their expression of FnRs without changing their expression of FN. Furthermore, TSH treatment may promote FN secretion by FTC-133, although it does not seem to affect FnR or absolute FN expression. The diminished expression of FnR adhesion plaques may enhance metastatic potential in some follicular thyroid cancers.

Adenocarcinoma, Follicular↗
PubMedDate not supplied

Two types of mutants affecting voltage-sensitive sodium channels in Drosophila melanogaster.

Voltage-sensitive sodium channels have a key role in the genesis of propagated action potentials. Mutations that affect these channels might be used like specific pharmacological agents in studies of channel structure and regulation. We have found that mutations which cause a reversible, temperature-induced paralysis in the fruit fly Drosophila melanogaster often affect the voltage-sensitive sodium channel. Using 3H-saxitoxin binding to membrane preparations, we have now identified two types of presumptive sodium channel mutants. One mutation, seizurets-2 (seits-2), appears to alter saxitoxin-binding sites structurally. The second, no-action-potential (napts) (refs 5, 6), reduces the number of saxitoxin-binding sites, but appears not to alter the receptor structure.

Animals↗
PubMedDate not supplied

Hormone producing pancreatic islet cell carcinoma: changing clinical presentation.

A patient with pancreatic islet cell carcinoma demonstrated spontaneous remission and recurrence of hyperinsulinism and disappearance of elevated plasma motilin levels. Despite evidence for gastrin production by the tumor initially, the Zollinger-Ellison syndrome was not diagnosed until three years after initial presentation. Diarrhea and steatorrhea could be attributed to hyperchlorhydria rather than to direct intestinal effects of elevated cirulating gastrin, gastric inhibitory peptide or motilin. Pancreatic islet cell carcinomas, considered as a type a APUD cell proliferation, frequently produce more than one hormone; the pattern of hormone secretion may differ with time and clinical manifestations may change accordingly.

Adenoma, Islet Cell↗
PubMedDate not supplied

CT evaluation of parathyroid adenomas: diagnostic criteria and pitfalls.

Sixty-three patients with biochemically proven primary hyperparathyroidism underwent CT of the neck and upper chest prior to surgery. All examinations were prospectively evaluated. Parathyroid adenomas were correctly identified on CT in 81% of patients. Thyroid adenomas, tortuous vessels, the esophagus, and atypical parathyroid adenomas may be potential sources of error in the diagnosis of parathyroid adenomas.

Adenoma↗
PubMedDate not supplied

Pediatric hospitalists: quality care for the underserved?

Despite the rapid growth in pediatric hospitalist services, there is little empiric information about the impact of pediatric hospitalists. This study compared process and outcome variables related to the inpatient care of 182 pediatric patients, half of whom were cared for by hospitalists and half by their primary care providers (PCP). Results indicated that, while hospitalists cared for patients of substantially lower socioeconomic status, they delivered care more economically for patients with asthma, with no significant differences in rates of return to the emergency room or rehospitalizations. Children in both services demonstrated equivalent levels of returning to their PCP for follow-up visits and were in equally good health 1 month after discharge. Additionally, no negative impact was evident on patient satisfaction at discharge; in fact, the hospitalists' patients were more satisfied with aspects of their care. Hospitalists may, therefore, provide a vital service by ensuring quality inpatient care for low-income children.

Analysis of Variance↗