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Biomedical subjects

S Riley

Publications and source records attributed to S Riley.

32 records · Page 2Linked to original sources
PubMed1995

p53 protein accumulation in tumors of the ampulla of Vater.

BACKGROUND: Accurate preoperative diagnosis of tumors of the ampulla of Vater is difficult because ampullary biopsies have a high false-negative rate. Recently, it has been suggested that p53 mutations in tumors of the ampulla of Vater are associated with the transformation of adenomas and low grade carcinomas to high grade carcinomas. The purpose of this study was to determine the extent of p53 protein accumulation in tumors of the ampulla of Vater, and to determine whether p53 accumulation can be detected in false-negative biopsies. METHODS: Using a monoclonal anti-p53 antibody, sections of 4 normal ampullas, 5 adenomas, 17 carcinomas, and 9 initial biopsies of 9 of the tumors of the ampulla of Vater that had no morphologic evidence of carcinoma were immunostained. RESULTS: None of the 4 normal ampullas (0%), 2 of 5 adenomas (40%), and 16 of 17 carcinomas (94%) were positive for p53. This p53 positivity was present through all stages of ampullary carcinoma. Of the nine initial biopsies negative for carcinoma, seven were positive for p53 and, of these, six (86%) were found to be carcinomas upon resection. CONCLUSIONS: 1) The molecular events leading to p53 accumulation in tumors of the ampulla of Vater occur early in the neoplastic process. 2) Tumors of the ampulla of Vater with biopsies negative for malignancy but positive for p53 are very likely to be carcinomas.

Adenoma↗
PubMed1989

Floating dislocated elbow: case report and review of the literature.

A 59-year-old shrimper sustained ipsilateral fractures of the midshafts of the humerus, ulna, and radius, as well as an ipsilateral posterior dislocation of the elbow. The mechanism of this unusual injury involved the winch system of a shrimpboat. Closed reduction of the dislocation along with open reduction and internal fixation of the fractures allowed early elbow motion. The resulting final range of motion and function were good.

Accidents, Occupational↗
PubMed1988

Isotype, VH genes, and antigen-binding analysis of hybridomas from newborn normal BALB/c mice.

In this study we report on the characterization of a panel of 62 hybridomas generated by fusing unstimulated spleen cells from neonatal (less than 24 hr old) normal BALB/c mice with the non-secreting Sp 2/0 cell line. The vast majority (98%) of these hybridomas secreted Ig but only 20% produced IgM. The isotype of the remaining hybridomas was determined as being IgG2b. Interestingly, when splenocytes from 1-day-old mice were stimulated with LPS for 48 h prior to the fusion event, 84% of the hybridomas were secreting IgM. The hybridoma supernatants were screened either by ELISA or RIA for binding reactivity using a panel of 17 Ag, proportionally divided between self and non-self. A binding reactivity could be assigned in 44% of cases. Of these, 29% were monoreactive, i.e., reactivity occurred with one Ag only, while the remaining 15% were multireactive. The majority (21 of 27) of hybridomas with a defined reactivity were directed against self-Ag. These included autologous red blood cells, DNA, histone H1, thyroglobulin, and Ag of the cell surface of T cells. The frequency of utilization of VH genes was determined using DNA probes for eight VH gene families. While all VH gene families appeared to have been used, one, VH 7183, had a slight but significant (p less than 0.02) higher utilization than expected by random expression. The frequency of all the other VH gene families was not significantly different from random utilization. No correlation was found between Ag reactivity in the supernatants and the utilization of a particular VH gene family. These findings indicate that early in the ontogeny the predominant reactivity of B cells is for self-Ag and, unlike what it is commonly believed, the IgM isotype is not dominant within these endogenously activated B cells at this time of ontogeny when genes from all VH families are utilized.

Animals↗
PubMed1984

The effects of hypocapnia on intracellular pH and bicarbonate.

The intracellular pH (pHi) and bicarbonate concentration ([HCO3-]icw) of cardiac and skeletal muscles were monitored during respiratory alkalosis in order to further elucidate the homeostatic processes which operate in these tissues to ameliorate deviations from normal acid-base status. Rats were mechanically hyperventilated to induce hypocapnia, pHi was determined by the DMO method, and [HCO-3]icw was calculated from the Henderson-Hasselbalch equation using pHi and the partial pressure of carbon dioxide of vena caval blood. A significant intracellular alkalosis occurred in both cardiac and skeletal muscles during hypocapnia, but the changes in pHi were less in the heart than in skeletal muscle. The decreases in cardiac [HCO-3]icw were greater than those attributable to the physicochemical buffering of the heart. These data are consistent with an intramyocardial source of protons other than physicochemical buffering during respiratory alkalosis. The decreases in skeletal muscle [HCO-3]icw were less than those due to physicochemical buffering. These data are consistent with a net extrusion from skeletal muscles cells of the protons derived from physicochemical buffering during respiratory alkalosis.

Acid-Base Equilibrium↗
PubMedDate not supplied

Comparison of two transdermal nitroglycerin systems: Transderm-Nitro and Nitro-Dur.

Sixty-four patients with stable angina pectoris were enrolled in a four-week, multicenter, office-based study to compare the adhesive properties of an patients' preferences for two transdermal nitroglycerin systems, Transderm-Nitro (TDN) and Nitro-Dur (ND). Each patient simultaneously wore one 0.2 mg/hr (formerly 5 mg/24 hr) TDN patch and one 0.2 mg/hr ND patch. At the first and last study visits, patients completed questionnaires that assessed preferences based on ease of application, handling, and removal; ease of removing the backing; overall adhesion; adhesion under certain conditions; comfort; curling or rolling; and skin irritation. Each day of the study, patients recorded the number of anginal episodes experienced, frequency of sublingual nitroglycerin use, patch adhesion, and problems at the sites of application or any other medical problems. Differences in adhesive properties were statistically significant in favor of TDN over ND (P less than or equal to 0.001). Of the TDN patches, 98.5% adhered completely, compared with 81.8% of the ND patches. No serious or unexpected adverse reactions occurred. Overall, patients preferred TDN to ND by a statistically significant margin (P = 0.0002).

Adhesives↗