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Biomedical subjects

S W Ross

Publications and source records attributed to S W Ross.

13 recordsLinked to original sources
PubMed2001

Physiological (antioxidant) responses of estuarine fishes to variability in dissolved oxygen.

Cycles of dissolved oxygen (DO) in estuaries can range from anoxia to various levels of supersaturation (200-300%) over short time periods. Aerobic metabolism causes formation of damaging reactive oxygen species (ROS), a process exacerbated by high or low DO. Fish can generate physiological defenses (e.g. antioxidant enzymes) against ROS, however, there are little data tying this to environmental conditions. We investigated physiological defenses generated by estuarine fishes in response to high DO and various DO cycles. We hypothesized that chemical defenses and/or oxidative damage are related to patterns of DO supersaturation. Specific activities of antioxidants in fish tissues should be positively correlated with increasing levels of DO, if high DO levels are physiologically stressful. We caged common benthic fishes (longjaw mudsucker, Gillichthys mirabilis, and staghorn sculpin, Leptocottus armatus, in CA and spot, Leiostomus xanthurus and pinfish, Lagodon rhomboides, in NC) during summer 1998 in two estuarine sites in southern North Carolina and two in central California. At each site a water quality meter measured bottom DO, salinity, temperature, depth, pH and turbidity at 30 min intervals throughout the study. These sites exhibited a wide variety of dissolved oxygen patterns. After 2 weeks in the cages, fish gills and livers were analyzed for antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase) and the metabolite glutathione. All fish exhibited antioxidant enzyme activity. There was a significant site-dependent effect on all enzyme activities at the NC sites, with the most activity at the site with the highest DO cycling and the most DO supersaturation. There was a trend towards higher enzyme activities under high DO levels at the CA sites.

Adaptation, Physiological↗
PubMed1997

Teniposide (VM-26) as a single drug treatment for patients with extensive small cell lung carcinoma: a Phase II study of the Southwest Oncology Group.

BACKGROUND: Teniposide (VM-26) was reported to have activity in small cell lung carcinoma (SCLC). The authors performed a Phase II study of teniposide as a treatment for patients with previously untreated extensive SCLC. METHODS: The study was open to patients with a histologic or cytologic diagnosis of extensive SCLC who had not received prior radiation or chemotherapy. Patients with hematologic values below normal were considered eligible if the impaired bone marrow function was directly attributable to disease involvement. Treatment consisted of teniposide 60 mg/m2 given intravenously (i.v.) on Days 1-5 every 3 weeks. RESULTS: This study opened on September 15, 1988, closed permanently on November 15, 1990, and accrued 45 patients identified at 19 academic, military, and Community Clinical Oncology Program institutions affiliated with the Southwest Oncology Group. Of the 45 registered patients, 41 were eligible. Twenty eight (68%) were males and 13 (32%) were females; the median age was 64 years (minimum, 46 years; maximum, 83 years). Twenty-four patients (59%) had a performance status (PS) on the Zubrod scale of 0-1 and 17 cases (41%) had a PS of 2. Of the 41 eligible patients, 10 had confirmed partial responses (24%) (95% confidence interval, 12-40%). The median survival was 7 months. The significant toxicities noted were Grade 4 leukopenia and/or granulocytopenia, experienced by 15 patients; 1 of these patients also had Grade 4 hyponatremia. One patient died of a respiratory infection. CONCLUSIONS: When administered according to the dosage and schedule selected for this study (60 mg/m2 i.v. on Days 1-5 every 3 weeks), teniposide as a single agent had modest activity in extensive small cell lung carcinoma. The toxicities observed in this study were acceptable.

Actuarial Analysis↗
PubMed1996

Phase II trial of trimetrexate in advanced esophageal cancer: a southwest oncology group study.

Trimetrexate (TMQ) is a synthetic folate antagonist that has demonstrated non-cross resistance with methotrexate in preclinical screens. A phase II trial was performed with TMQ given to patients with advanced squamous cell carcinoma of the esophagus. TMQ was administered as an i.v. bolus on a daily x 5 schedule, every 3 weeks; a starting dose of 12 mg/m2 was used for patients with no prior irradiation, and of 8 mg/m2 for patients with prior irradiation. Twenty-four patients were entered onto study, with 23 patients eligible, and a median of 2 courses of TMQ administered per patient. Twenty-three patients were evaluable for toxicity. Toxicities of SWOG grade > or = 3 included granulocytopenia (9 patients), leukopenia (7 patients), thrombocytopenia (4 patients), anemia (3 patients), mucositis (3 patients), nausea and vomiting (2 patients), dermatitis (1 patient), diarrhea (1 patient), and fever (1 patient). Fifteen patients had some hematologic toxicity, and eleven patients had hematologic toxicity of grade > or = 3. Two treatment related deaths occurred in association with myelosuppression. One patient achieved a complete response and one patient achieved a partial response, with response durations of 8.5 months and 6 months, respectively. The overall response rate was 8% [95% confidence interval of 1 to 28%], with a median survival for the 23 eligible patients of 5.1 months.

Antimetabolites, Antineoplastic↗
PubMed1995

Centromeric instability of chromosome 1 resulting in multibranched chromosomes, telomeric fusions, and "jumping translocations" of 1q in a human immunodeficiency virus-related non-Hodgkin's lymphoma.

BACKGROUND: Acquired immunodeficiency syndrome-related non-Hodgkin's lymphomas are associated with the B-cell chromosomal translocation t(8;14)(q24; q32). The most common secondary chromosome aberrations in these patients involve 1q and are believed to be associated with tumor progression. A mechanism for the origin of these 1q aberrations has not been demonstrated. To their knowledge, the authors report the first human immunodeficiency virus (HIV)-positive patient to have centromeric decondensation and multibranched chromosome aberrations of chromosomes 1 and 16 resulting in telomeric associations and "jumping translocations" of 1q. METHODS: Tumor cells from peritoneal fluid of an HIV-positive patient were cultured for 24, 48, and 72 hours and analyzed by both conventional G-banding and fluorescence in situ hybridization. RESULTS: G-band analysis showed a stemline with t(8;14)(q24;q32), but also showed the progression from centromeric decondensation to multibranched chromosome configurations of chromosomes 1 and 16. The interchange and duplications of chromosome arms resulted in the gain of extra copies of 1q material on a number of different chromosomes, but also the loss of 16q in at least one sideline and the formation of micronuclei. Fluorescence in situ hybridization analysis demonstrated that micronuclei predominantly involved chromosome 1 and, to a lesser extent, chromosome 16. CONCLUSIONS: The cytogenetic findings in this unique case suggest that immunodeficiency may be a factor involved in centromeric instability, multibranching, and the progression to the subsequent formation of telomeric fusions and multiple unbalanced translocations of 1q (jumping translocations). The striking similarity of the centromeric instability in this patient to those with ICF syndrome (variable immunodeficiency, centromeric heterochromatin instability, and facial anomalies) suggests hypomethylation as the etiologic mechanism for the chromosome instability.

Adult↗
PubMed1987

Glycemic index of processed wheat products.

Our aim was to determine the in vivo glycemic and insulin responses and in vitro starch digestibility of seven processed wheat products (shortbread biscuits, custard, quick-cooking wheat, wholemeal bread, water biscuits, puffed wheat, and puffed crispbread). The degree of starch gelatinization in the foods was measured. Fifty-gram carbohydrate portions of the foods were fed to eight volunteers after an overnight fast. The calculated glycemic indices (GI) (mean +/- SEM) ranged from 43 +/- 10 for custard to 81 +/- 9 for puffed crispbread. Insulin responses paralleled the glycemic responses. The GI correlated positively with the percentage of starch digested in vitro (p less than 0.05). The degree of starch gelatinization ranged from 0.4 to 60% and correlated positively with the percentage starch digested in vitro (p less than 0.05). Differences in the glycemic and insulin responses to wheat products may be explained in part by the extent of processing and the degree of gelatinization achieved.

Blood Glucose↗