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Biomedical subjects

C Swanson

Publications and source records attributed to C Swanson.

At least 55 records · Page 3Linked to original sources
PubMed1993

Saturated fat intake and lung cancer risk among nonsmoking women in Missouri.

BACKGROUND: Although the vast majority of lung cancer cases in women are caused by smoking, 9%-20% of cases occur in nonsmokers. Previous epidemiologic research on the relationship between lung cancer and diet has shown that fruit and vegetable consumption may confer a protective effect against lung cancer, while a diet rich in cholesterol and fat may increase risk. PURPOSE: The purpose of this case-control study was to examine the effects of a broad range of dietary factors on the risk of lung cancer in a population of nonsmoking white women 30-84 years of age. METHODS: A telephone-administered questionnaire was used to determine and/or verify eligibility with regard to age, gender, race, and smoking status. In a second interview at the participant's home, a widely used food frequency questionnaire was filled out, and logistic regression was subsequently used to analyze the responses. We obtained dietary information on 429 case subjects who had a diagnosis of lung cancer reported to the Missouri Cancer Registry between June 1, 1986, and June 1, 1991, and 1021 control subjects. If a case subject had died or was too ill to be interviewed, next-of-kin familiar with the woman's diet were interviewed instead. Of the 429 women with lung cancer, 211 (49%) had lung adenocarcinoma. RESULTS: A strongly increasing trend in lung cancer risk was observed with increased saturated fat consumption among these non-smoking women; the relative risk was more than sixfold greater for the highest quintile of consumption than for the lowest quintile. The effect of saturated fat was more pronounced for adenocarcinoma than for other cell types. Weekly servings of beans and peas were significantly related to decreased lung cancer risk, while citrus fruit and juice showed a twofold increase in risk; this trend was also significant. CONCLUSION: By focusing on non-smoking women with lung cancer, including a large number with adenocarcinoma, we observed a clear association with saturated fat consumption that may have been masked in earlier studies of lung cancer involving a high percentage of smokers.

Adult↗
PubMed1993

Clinical and laboratory markers of hypersensitivity to trimethoprim-sulfamethoxazole in patients with Pneumocystis carinii pneumonia and AIDS.

A group of clinical, immunologic, and virologic variables was examined to determine if any predicted the development of hypersensitivity to trimethoprim-sulfamethoxazole (TMP-SMZ) during treatment of Pneumocystis carinii pneumonia in patients with human immunodeficiency virus (HIV) infection. Hypersensitivity occurred in 39 (27%) of 143 patients, who had significantly higher total lymphocyte and CD4+ and CD8+ cell counts and CD4:CD8 ratios than did those who did not develop hypersensitivity. Regression analysis identified having a CD4:CD8 ratio > 0.10 (95% confidence interval [CI], 1.75-3.94; P = .02) and treatment for < 14 days (95% CI, 1.57-3.75; P = .04) as independently predictive of hypersensitivity. Use of corticosteroids tended to reduce the frequency of hypersensitivity (7% vs. 30%; P = .07). T lymphocytes may be important in the pathogenesis of these hypersensitivity reactions. As the frequency of hypersensitivity declines with disease progression, T lymphocytes could be effector cells in these reactions or their sensitivity to TMP-SMZ may decline with HIV disease progression.

AIDS-Related Opportunistic Infections↗
PubMed1993

Quality assessment and improvement in group psychotherapy.

OBJECTIVE: The authors sought a practical means of monitoring and evaluating group psychotherapy, using existing clinical resources, for purposes of quality improvement and education on a large general hospital psychiatric service. METHOD: Monitoring indicators were developed which addressed 1) the integration of group psychotherapy into treatment planning and 2) the competence and technique of group psychotherapists. The second indicator was assessed by skilled observers using a newly constructed Group Psychotherapy Rating Scale in direct observation of group psychotherapy sessions. The rating scale was examined for interrater reliability and, as a measure of construct validity, for its ability to distinguish the performance of professional staff therapists from that of trainees. RESULTS: The indicators provided useful monitors of the use and quality of group psychotherapy. The rating scale had satisfactory interrater reliability and construct validity. The immediate constructive educational critique given by the observers of the therapy groups was highly valued by group therapists. CONCLUSIONS: The monitoring and evaluation program proved to be a practical, positive, and inexpensive means of assuring and improving the quality of group psychotherapy in a clinical setting.

Humans↗
PubMed1992

Dihydrolipoic acid--a universal antioxidant both in the membrane and in the aqueous phase. Reduction of peroxyl, ascorbyl and chromanoxyl radicals.

Thioctic (lipoic) acid is used as a therapeutic agent in a variety of diseases in which enhanced free radical peroxidation of membrane phospholipids has been shown to be a characteristic feature. It was suggested that the antioxidant properties of thioctic acid and its reduced form, dihydrolipoic acid, are at least in part responsible for the therapeutic potential. The reported results on the antioxidant efficiency of thioctic and dihydrolipoic acids obtained in oxidation models with complex multicomponent initiation systems are controversial. In the present work we used relatively simple oxidation systems to study the antioxidant effects of dihydrolipoic and thioctic acids based on their interactions with: (1) peroxyl radicals which are essential for the initiation of lipid peroxidation, (2) chromanoxyl radicals of vitamin E, and (3) ascorbyl radicals of vitamin C, the two major lipid- and water-soluble antioxidants, respectively. We demonstrated that: (1) dihydrolipoic acid (but not thioctic acid) was an efficient direct scavenger of peroxyl radicals generated in the aqueous phase by the water-soluble azoinitiator 2,2'-azobis(2-amidinopropane)-dihydrochloride, and in liposomes or in microsomal membranes by the lipid-soluble azoinitiator 2,2'-azobis(2,4-dimethylvaleronitrile); (2) both dihydrolipoic acid and thioctic acid did not interact directly with chromanoxyl radicals of vitamin E (or its synthetic homologues) generated in liposomes or in the membranes by three different ways: UV-irradiation, peroxyl radicals of 2,2'-azobis(2,4-dimethylvaleronitrile), or peroxyl radicals of linolenic acid formed by the lipoxygenase-catalyzed oxidation; and (3) dihydrolipoic acid (but not thioctic acid) reduced ascorbyl radicals (and dehydroascorbate) generated in the course of ascorbate oxidation by chromanoxyl radicals. This interaction resulted in ascorbate-mediated dihydrolipoic acid-dependent reduction of the vitamin E chromanoxyl radicals, i.e. vitamin E recycling. We conclude that dihydrolipoic acid may act as a strong direct chain-breaking antioxidant and may enhance the antioxidant potency of other antioxidants (ascorbate and vitamin E) in both the aqueous and the hydrophobic membraneous phases.

Animals↗
PubMed1992

The effect of transplantation site and islet mass on long-term survival and metabolic and hormonal function of canine purified islet autografts.

Determination of the long-term function of islet transplantation in relation to the implantation site and the numbers of islets is of scientific interest and, with human islet transplant trials in progress, is a pressing clinical question. In this study, highly purified canine islets were isolated by collagenase digestion and Ficoll purification, and autotransplanted into either the spleen (in 10 dogs) or the liver (in 12 dogs). Dogs transplanted with islets into the spleen or liver received 264,300 +/- 20,300 (mean +/- SEM) and 158,600 +/- 15,000 islet equivalents (150-microns-sized islets) respectively. Graft survival at 1 yr was 86% in intrasplenic islet autografts (ISTx) and 50% in intraportal islet autografts (IPTx). Intravenous glucose tolerance tests and mixed meal-oral glucose tests were performed 1-12 mo from islet transplantation. Compared to controls, ISTx and IPTx dogs showed a similar decrease of glucose tolerance after both intravenous glucose tolerance tests and mixed meal-oral glucose tests. On intravenous glucose tolerance tests, plasma insulin levels were lower in ISTx than in IPTx dogs and controls. On mixed meal-oral glucose tests, insulin values were higher in IPTx dogs than in controls. There was a positive correlation (r = .56, p < 0.05) between the number of transplanted islet equivalents and the K values. These results demonstrate that, in dogs with islet transplant: 1) long-term islet survival can be achieved in the spleen better than in the liver; 2) islet survival is related to the mass of transplanted islets in the spleen, but not in the liver, where other factors probably affect islet survival; 3) the ability of metabolizing glucose is reduced after both intrasplenic and intraportal islet autografts; 4) both reduced insulin secretion (predominant in ISTx dogs on intravenous glucose tolerance testing) and insulin resistance (predominant in IPTx dogs on mixed meal-oral glucose tests) are the probable causes of the decreased glucose tolerance.

Animals↗
PubMed1991

Effects of amiodarone on myocardial performance in normal canine hearts and canine hearts with infarcts.

The effects of IV administered amiodarone, a class-III antiarrhythmic agent, on myocardial contractility, early myocardial relaxation, and hemodynamic variables were evaluated in normal canine hearts and those with infarcts. In the normal canine heart, amiodarone had important, but relatively mild, depressant effects on left ventricular contractility (assessed by maximal positive first derivative of left ventricular pressure (+dP/dtmax) and maximal elastance (Emax)) and heart rate when given IV at a dose of 10 mg/kg of body weight. An effect on contractility or active relaxation (assessed by maximal negative first derivative of left ventricular pressure (-dP/dtmax) and the time constant of isovolumic pressure decrease) was not identified with smaller doses. Myocardial infarction itself caused a predictable and marked depressant effect on myocardial contractility, as indicated by decreases in +dP/dtmax, ejection fraction, Emax, and -dP/dtmax, and elevation in end diastolic pressure. Additional depressive effects on contractility and active relaxation resulted when 10 mg of amiodarone/kg was administered to dogs with myocardial infarction and these effects were sufficient to worsen acute myocardial infarction-induced heart failure. Significant changes attributable to heart rate alone could not be identified. On the basis of our findings, we suggest that amiodarone administered IV should be used with caution in dogs with compromised ventricular function.

Amiodarone↗
PubMed1989

Sexual practices and condom usage in a cohort of homosexual men in relation to human immunodeficiency virus status.

Between January 1, and October 31, 1987, 420 homosexual men who participated in a cohort study of infection with the human immunodeficiency virus (HIV) completed a questionnaire that examined their sexual practices during the previous six months. Of the subjects, 205 (48.8%) men were HIV-seropositive and 215 (51.2%) men were HIV-seronegative. Although there was an appreciable level of condom usage in both groups, 13.5% of the HIV-seronegative men had engaged in unprotected receptive anal intercourse and 6.3% of the HIV-seropositive men had engaged in unprotected insertive anal intercourse. Condom breakage was reported on approximately 6% of occasions by a minority of subjects. Among subjects who were in a relationship with a regular male sexual partner, the most commonly reported sexual practices were deep kissing, mutual masturbation and receptive oral intercourse without ejaculation. No HIV-seronegative man engaged in unprotected receptive and/or insertive anal intercourse, receptive oral intercourse with ejaculation or receptive and/or insertive "fisting" with a regular partner who was HIV-seropositive. No HIV-seropositive man engaged in unprotected insertive anal intercourse to ejaculation with an HIV-seronegative partner, although they did so with partners who were HIV-seropositive or of unknown status. On multivariate analyses the subject's antibody status was found to be associated with receptive anal intercourse with a condom (P = 0.007) and mutual masturbation (P = 0.001), with HIV-seronegative men being more likely to practise either; no significant independent effect was associated with the partner's antibody status. These findings provide important information on the types and levels of sexual practices in a group of homosexual men after the recognition of the acquired immunodeficiency syndrome in this country.

Adult↗
PubMed1989

Neonatal hyperviscosity association with lower achievement and IQ scores at school age.

A longitudinal study was conducted to determine whether the early neurologic and motor impairment observed in children with neonatal polycythemia and hyperviscosity persisted into school age. Forty-nine children who had neonatal polycythemia and hyperviscosity were evaluated at a mean age of 7 years. Of these, 21 (group 1) received a partial plasma exchange transfusion, whereas 28 (group 2) received symptomatic care. Forty control children (group 3) with a normal neonatal hematocrit were also evaluated. Testing consisted of a battery of measures to evaluate IQ, achievement, neuromotor function, and gross and fine motor skills. Maternal education and IQ were also assessed to avoid potential confounding by differences in the home environment. The neonatal course of the children with polycythemia and hyperviscosity was characterized by an increased number of problems, including hypoglycemia and cyanosis. At 7 years of age, the 49 children who had hyperviscosity (groups 1 and 2) had significantly lower "spelling" and arithmetic achievement test results and gross motor skill scores. Scores for reading, visual motor integration, and neurologic signs did not differ significantly from group 3. Maternal IQ scores were similar for both groups. Left-hand preference was seen in 14% of group 1 and 2 children and 7% of group 3 children (not significant). The scores for IQ, achievement, neuromotor function, and visual motor integration were compared for the hyperviscosity group (groups 1 and 2) and the control group (group 3) by multivariate analysis of variance with sex and hyperviscous group as independent variables and maternal education and maternal IQ as covariates (P = .040).(ABSTRACT TRUNCATED AT 250 WORDS)

Achievement↗
PubMed1988

Chemotherapy of advanced head and neck cancer: updated results of a randomized trial of the order of administration of sequential methotrexate and 5-fluorouracil.

One hundred and twenty-seven patients with advanced or recurrent squamous cell carcinoma of the head and neck (HNC) were randomized to treatment with methotrexate (MTX) followed 1 hour later by 5-fluorouracil (5-FU) (sequence MF), or 5-fluorouracil followed after 1 hour by methotrexate (sequence FM). One hundred and seventeen patients were evaluable for response. There was no significant difference in response rates between the MF and FM sequences. Overall, 8 patients (6.8%) achieved complete response (CR) and 46 (39.3%) partial response (PR). In 95 previously untreated patients, the overall response rate (CR + PR) was 50%, compared with 31% for previously treated patients (P = 0.02). Survival duration significantly favored the FM sequence in univariate analyses (P = 0.04). Stepwise multivariate Cox model analysis showed that poor performance status (Eastern Cooperative Oncology Group) at study entry (P less than 0.001) and prior radiotherapy (P = 0.03) were significant adverse predictors for survival. When allowance was made for these factors, a survival difference in favor of the FM sequence remained (P = 0.003). Sequential MTX followed 1 hour later by 5-FU is not recommended for treatment of HNC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Prediction of long-term survival by flow cytometric analysis of cellular DNA content in patients with advanced ovarian cancer.

The prognostic value of cellular DNA content in ovarian cancer (malignant common epithelial tumors) was investigated by flow cytometric analysis of paraffin-embedded tumor blocks from 128 previously untreated patients with International Federation of Gynecology and Obstetrics (FIGO) stage III and IV ovarian cancer entered in a prospective clinical trial of combination v sequential therapy with chlorambucil and cisplatin. Seventy-three percent of tumors were aneuploid and 27% were diploid. Multivariate analysis using a Cox model showed that cellular DNA content (P less than .001) and FIGO stage (P less than .02) were the only significant independent prognostic variables. The median survival was 13 months for patients with aneuploid tumors and 60 months for patients with diploid tumors (P less than .0001). Further analysis indicated that the good prognosis associated with diploid tumors was limited to patients with stage III disease, all patients with stage IV (spread beyond the peritoneal cavity or liver metastases) disease having a poor prognosis irrespective of ploidy. On pathological review, nine borderline ovarian tumors (of low malignant potential) were identified, and seven of these were diploid. These tumors have an unusually favorable prognosis, despite apparent dissemination within the peritoneal cavity, a paradox which is often difficult to explain using conventional histological criteria. Although the vast majority of tumors in this study (93%) were classified as invasive epithelial ovarian cancers, it is possible that some of the patients with stage III diploid tumors may have had malignancies that were predominantly of low malignant potential, thus accounting in part for the prognostic significance of DNA content. By incorporating flow cytometric DNA analysis with careful histopathological assessment, it may be possible to better identify patients with an inherently good prognosis. This assumes particular importance, as the relatively favorable prognosis of patients with stage III diploid ovarian tumors appears to be independent of the type of treatment.

Antineoplastic Combined Chemotherapy Protocols↗