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Biomedical subjects

M Swanson

Publications and source records attributed to M Swanson.

At least 55 records · Page 3Linked to original sources
PubMed1989

The mutagenic potential of high flash aromatic naphtha.

Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--high-flash aromatic naphtha. A program was initiated to assess the toxicological properties of high-flash aromatic naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted partly to assess the potential for mutagenic activity and also to assist in an assessment of carcinogenic potential. The specific tests utilized included the Salmonella/mammalian microsome mutagenicity assay, the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) forward mutation assay in CHO cells, in vitro chromosome aberration and sister chromatid exchange (SCE) assays in CHO cells, and an in vivo chromosome aberration assay in rat bone marrow.

Administration, Inhalation↗
PubMed1989

Cholangitis due to Blastomyces dermatitidis.

A 70-yr-old woman presented with nonspecific complaints and had findings of a cholestatic liver enzyme pattern and a dilated left intrahepatic ductal system by radiographic imaging. Endoscopic retrograde cholangiopancreatography revealed multiple irregular flat stones and a fixed filling defect of the left hepatic duct. At the time of surgery a stonelike lesion of this ductal orifice was found along with a miliary pattern of infection of the left liver lobe. Histologic and microbiologic studies confirmed an infection by Blastomyces dermatitidis. Therapy with amphotericin B resulted in eradication of this infection. Despite their rarity, fungal infections of the biliary tree need to be considered in the differential diagnosis of biliary tract disease in the elderly and immunocompromised patient.

Aged↗
PubMed1988

Dietary epidemiology of cancer of the colon in western New York.

The authors interviewed 428 pathologically confirmed cases of colon cancer and controls matched on age, sex, race, and neighborhood in the New York counties containing the cities of Buffalo, Niagara Falls, and Rochester. Risk of colon cancer in both males and females, studied separately, appeared to increase with the amount of total fats and total calories ingested. In addition, we found the risk to increase with increases in the Quetelet index of relative weight (weight (kg)/height (m)2). Dietary fiber was only equivocally associated with risk. Fats and Quetelet index were associated with increased risk in a regression analysis adjusting each factor for the other, as well as for fiber, age, and socioeconomic status. The same was true for calories and Quetelet index. Future efforts to clarify a possible protective role for fiber and to disentangle the effects of fats and calories need to be undertaken. The fact that calories ingested and obesity are each associated with increased risk suggests the importance of studying calorie expenditure.

Body Height↗
PubMed1987

Expression of human gamma-globin genes in human erythroleukemia (K562) cells.

K562 cells express embryonic (epsilon) and fetal (gamma) globins and hemoglobins but not adult (beta) globin. To define the cis acting regulatory elements involved in the discrimination between gamma and beta genes, we have constructed chimeric genes composed of portions of gamma and beta and evaluated their expression in stable K562 transfectants. A gamma beta fusion gene containing gamma 5' sequences to the EcoRI site in exon 3 and beta sequences 3' is expressed at 10-40% that of the endogenous gamma level. In 50% of the lines, this fusion gene appropriately increases its expression in response to hemin, an inducer of endogenous globin gene expression in K562 cells. In contrast, a beta gamma fusion gene, containing beta sequences 5' to the EcoRI site in exon 3 and gamma sequences 3', is neither expressed nor correctly initiated. A beta gene containing gamma-intervening sequence (IVS) 2 accumulates an mRNA transcript when analyzed with a 3' beta probe. However, no correctly initiated beta mRNA is observed. A gamma gene with beta-IVS 2 is only inducible in one of six expressing clones. All the results are consistent with the presence of stage-specific trans acting factors in K562 cells that stimulate expression of gamma genes and suggest a significant role for gamma-IVS 2 in gamma gene expression.

Cell Line↗
PubMed1987

Gastric bypass.

The success of gastric bypass probably depends on factors other than merely the restrictive size of the gastric pouch and outlet. Postoperative dumping and a mild degree of malabsorption derived from the redirection of intestinal contents contribute to long-term success. Thus, gastric bypass combines some elements of both malabsorptive and gastric restrictive procedures.

Adult↗
PubMed1986

Multifocal eosinophilic granuloma. Response of a patient to etoposide.

A 60-year-old man with a history of diabetes insipidus presented with a left groin mass, leg edema, and retroperitoneal adenopathy. Biopsy results of the involved lymph nodes were typical of eosinophilic granuloma. The patient was treated with etoposide and prednisone and had a complete regression of his lymphadenopathy and edema. This response suggests that etoposide may be a useful agent in the management of histiocytosis X.

Eosinophilic Granuloma↗
PubMed1986

Cigarette smoking in women with cancers of the breast and reproductive organs.

This case-control study addressed the relationship between cigarette smoking and cancers of the breast (1,741 cases), endometrium (476 cases), uterine cervix (1,174 cases), and ovary (296 cases). The lifetime smoking history of cases was compared with that of 2,128 controls, and relative risks (odds ratios) for smoking were estimated using multiple logistic regression to adjust for potential confounding by age, marital status, number of pregnancies, and Quetelet's index. With increasing amount smoked there was a statistically significant decrease in endometrial cancer risk and a statistically significant increase in cervical cancer risk. In the highest smoking category (greater than or equal to 15 pack-yr), the endometrial cancer relative risk was 0.57 [95% confidence interval (CI) of 0.37, 0.86] and the cervical cancer relative risk was 1.81 (95% CI of 1.47, 2.22). There was no apparent relationship between smoking and cancers of the breast or ovary.

Adult↗
PubMed1985

Occupation and lung cancer risk. An analysis by histologic subtypes.

The relationships between cigarette smoking, occupational exposures, dietary vitamin A and lung cancer is explored in a case-control study. The study is based on 1002 primary lung cancers among white men and 1119 white male controls between 35 and 79 years of age admitted to Roswell Park Memorial Institute from 1957 to 1965. Four hundred sixty-four lung cancer cases were classified as one of the three major histologic cell types: squamous, small cell, or adenocarcinoma. Each of the three main histologic types displayed a statistically significant trend of increasing risk associated with increasing consumption of cigarettes with the strongest relationship being seen for small cell carcinoma (odds ratio for 40+ pack-years = 17.5) and the weakest with adenocarcinoma (odds ratio for 40+ pack-years = 6.7). Increasing risk for squamous cell cancer was seen with increasing duration of exposure to all lung carcinogens, asbestos, and aromatic hydrocarbons. Small cell carcinomas were not associated with any of the occupational exposure categories studied with the exception of asbestos exposure in light smokers. Increasing risk of adenocarcinoma was seen with increasing duration of employment in occupations with potential exposure, but only for light smokers. Dietary vitamin A consumption did not confound the occupational associations. Hypotheses have been generated regarding interplay of risk factors in the etiology of different histologic subtypes of lung cancer. Studies of specific histologic types of lung cancer are needed to elucidate the role of various environmental and occupational risk factors.

Adenocarcinoma↗
PubMed1984

Dietary vitamin A and lung cancer risk: an analysis by histologic subtypes.

A case-control study was conducted based on 427 white males with lung cancer of the squamous, small cell, and adenocarcinoma histologic subtypes and 1,094 white male controls admitted to Roswell Park Memorial Institute between the years 1957 and 1965. The relation between selected dietary factors and lung cancer risk was examined for each histologic subtype while controlling for past cigarette use. Dietary vitamin A was found to be negatively associated with risk for squamous cell and small cell carcinoma, but not for adenocarcinoma of the lung. No significant association was observed, however, between dietary vitamin C, fats, or fiber and any of the lung cancer subtypes. These results suggest that the apparent protective effect of vitamin A in lung cancer may be histologic type-specific.

Adenocarcinoma↗
PubMed1983

Diet and smoking in the epidemiology of cancer of the cervix.

This study of 513 white cervical cancer patients and 490 white hospitalized controls considered, with adjustment for marital history and parity, the effects of smoking and dietary characteristics on the relative risk of developing cervical cancer. Although smoking was shown to be positively associated with risk, no dose-response relationship was evident. The frequency of consumption of cruciferous vegetables was positively associated with risk. Respondent reports of the frequency of prior ingestion of several food items were used in constructing crude indices of exposure to basic nutrients; the index of beta-carotene exposure was negatively associated with risk, whereas the index of fat consumption was positively associated with risk.

Alcohol Drinking↗
PubMed1983

A case-control study of dietary and nondietary factors in ovarian cancer.

A case-control study is presented that estimates ovarian cancer risk for various factors, including diet. Data collected by interview between 1957 and 1965 for 274 white women aged 30-79 years with epithelial carcinoma of the ovary are compared to data similarly collected for 1,034 hospital controls. Relative risk estimates are presented for the total group as well as for premonopausal (ages 30-49) and postmenopausal (ages 50-79) are groups. In the total group, cancer risk increased with increasing age at first marriage (P less than .01) and previous history of benign breast disease (P less than 0.1), and risk decreased with increasing number of previous pregnancies (P less than .01). In the 50- to 79-year age group, a marginally significant trend for decreasing risk with increasing obesity was observed (P less than .10). There was no significant risk (i.e., P less than .10) associated with the consumption of alcohol, cigarettes, coffee, tea, total dietary protein, vitamin C, or fat at any age. In the 30- to 49-year age group only, increased risk (P less than .01) was seen in women reporting diets low in fiber and vitamin A from fruit and vegetable sources. Multiple regression analysis demonstrated that the apparent protective effect of vitamin A in the 30- to 49-year age group (but not dietary fiber) was independent of the nondietary factors analyzed in this study (P less than .05).

Adult↗
PubMed1982

Sex partners and herpes simplex virus type 2 in the epidemiology of cancer of the cervix.

The authors examined the interaction of exposure to various numbers of sex partners and evidence of antibodies to herpes simplex virus type 2 (HSV-2) in cervical neoplasia in 181 cases of cervical dysplasia, carcinoma in situ and cancer of the cervix and 130 control patients in Los Angeles County, California hospitals, in 1974-1979. Studies by the authors and other investigators have found that risk of cancer of the cervix was enhanced with numbers of sex partners, frequency and duration of using the vaginal douche, early age at first pregnancy, and antibodies to HSV-2 as measured by radioimmunoassay. In this study, it was found that for women with only one or no sex partner in their history, risk was elevated if evidence of antibodies to HSV-2 were present. The same was true for women with two or more sex partners. The risk associated with two or more sex partners was not higher than that for women with one sex partner among those positive for HSV-2, and among those negative for HSV-2. Thus, although this inquiry needs replication on larger numbers of women, whatever the other microorganisms or carcinogens patients were exposed to with multiple sex partners, there was no apparent effect beyond the fact that HSV-2 raises the risk of cancer of the cervix. This may strengthen credence in the hypothesis that HSV-2 is an etiologic factor in cervical cancer.

Adult↗
PubMed1982

Caffeine consumption and benign breast disease: a case-control comparison.

In this case-control comparison of 323 women with benign breast disease and 1,458 controls, no differences were noted in the coffee and tea consumption patterns of the cases and controls. These findings do not support the recent suggestion of Minton, et al, that methylxanthine ingestion is causally related to benign breast disease or breast cancer.

Adult↗