Molecular cloning of invasion genes from Yersinia and Salmonella.
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Alkaline Phosphatase↗
Biomedical subjects
B J Stone
Publications and source records attributed to B J Stone.
Occupation and hematopoietic and lymphoproliferative malignancies among women: a linked registry study.
Using a nationwide linked registry, we evaluated the incidence of several hematopoietic and lymphoproliferative (HLP) malignancies among Swedish women from 1961 to 1979 by industry and occupation. The risks of one or more types of HLP cancers (including the leukemias, non-Hodgkin's lymphoma, multiple myeloma, and mycosis fungoides) were significantly increased among women working in the agriculture and textile industries, housekeepers, and post office employees. Limitations of these linked-registry data include lack of detailed information on specific exposures and duration of employment, and the relatively small sizes of specific occupational cohorts. Nevertheless, as the proportion of women entering the workforce continues to increase, this data resource may provide additional clues to occupational determinants of HLP and other malignancies.
Female↗
Mouse T lymphocytes that express a gamma delta T-cell antigen receptor contribute to resistance to Salmonella infection in vivo.
Mice depleted of lymphocytes expressing the alpha beta or the gamma delta T-cell receptor for antigen (TCR) by antibody treatment were infected orally with Salmonella enteritidis. In both groups of treated mice, the 50% lethal dose decreased, suggesting that both the alpha beta TCR+ and the gamma delta TCR+ subsets contribute to resistance to oral infection. These data provide further evidence for the contribution of gamma delta T cells in the response to bacterial infections.
Animals↗
Occupational risks for colon cancer in Sweden.
Using the Cancer-Environment Registry of Sweden, which links census information (1960) with cancer incidence data (1961 to 1979), we conducted a systematic, population-based assessment of colon cancer incidence among cohorts defined by industry and occupation for all employed persons in Sweden. Small but statistically significant excesses of colon cancer were observed among white-collar occupations, including administrators, professionals, and clerical and sales workers, whereas a reduction in incidence was found among workers in agricultural and related jobs, such as farmers, fishermen, and hunters. Analysis by subsite within the colon revealed little difference in results. The observed risk patterns are consistent with previous reports on colon cancer risk and occupational physical activity levels, ie, elevated risk among sedentary white-collar workers and reduced risk among agricultural workers. Few craftsman and production processing jobs were linked to colon cancer, although statistically significant excesses were observed among shoe and leather workers, metal smiths, and foundry workers in the metal manufacturing industry. The findings indicate that occupation in general is likely to play a relatively small role in colon cancer etiology, with perhaps its major contribution an indirect one via physical activity.
Cohort Studies↗
Occupation and lung cancer risk among women in northern China.
Lifetime occupational histories were obtained in a case-control study of 965 female lung cancer patients and 959 controls selected from the general population in Shenyang and Harbin, People's Republic of China, where most women have worked outside the home. After adjusting for smoking, we found a significantly increased risk of lung cancer associated with employment involving the manufacture of transportation equipment (OR = 1.6, 95% CI = 1.0, 2.6), in particular the manufacturing of automobiles (OR = 3.0, 95% CI = 1.4, 6.4). Metal smelting and treatment workers were at an increased risk of lung cancer (OR = 1.5, 95% CI = 1.0, 2.1); the highest risks were observed among metal surfacers (OR = 3.1, 95% CI = 1.1, 9.0) and currently employed foundry workers (OR = 13.0, 95% CI = 1.7, 99.4). On the other hand, about a 50% decreased risk of lung cancer was observed among those employed in textile industries or as leaders of state and party organizations. Based on self-reports, exposures to coal dust and smoke from burning fuel at the workplace were also significant risk factors. The findings were similar when the analyses were confined to nonsmokers and were comparable across the major cell types of lung cancer.
Adenocarcinoma↗
Bias in learning disabilities placement.
A nationally representative sample of 20,614 eighth grade students was examined for bias in placement decisions for children said to have learning disabilities. Factors investigated for bias were race, sex, and socioeconomic status. Path analysis showed significant and direct paths from sex and race to placement, controlling for socioeconomic status, academic ability, and behavioral competency. Boys were overrepresented in such classes beyond what their somewhat lower academic and behavioral competencies would predict. Caucasians were similarly overrepresented controlling for other variables in the model. It appears that boys and Caucasians are overrepresented in learning disabilities placements on a national scale even when other contributing factors are controlled.
Bias↗
Renal cell cancer among architects and allied professionals in Sweden.
The Swedish Cancer-Environment Registry was used to evaluate a recent report of a large excess risk of renal cell cancer among architects in Los Angeles. We identified 131 renal cell cancers among male Swedish architects and allied professionals during a 19-year follow-up period (1961-1979). Compared with the Swedish population, there was no significant excess of renal cell cancer among architects and allied professionals (standardized incidence ratio (SIR) = 1.15; 131 cases). Although it was not possible to estimate the risk for architects alone, the SIR was only 1.06 (16 cases) in a subset of professionals employed in architectural and engineering firms. However, a significant increase in risk (SIR = 1.38) was observed in a related group of workers employed as engineers and construction supervisors in the home construction industry.
Architecture↗
Mortality among dust-exposed Chinese mine and pottery workers.
A cohort study of approximately 68,000 persons employed during 1972 to 1974 at metal mines and pottery factories in south central China was conducted to evaluate mortality from cancer and other diseases among workers exposed to different levels of silica and other dusts. A follow-up of subjects through December 31, 1989 revealed 6,192 deaths, a number close to that expected based on Chinese national mortality rates. There was, however, a nearly 6-fold increase in deaths from pulmonary heart disease (standard mortality ratio, 581; 95% confidence interval 538 to 626), and a 48% excess of mortality from nonmalignant respiratory diseases (standard mortality ratio, 148; 95% confidence interval, 139 to 158), primarily because of a more than 30-fold excess of pneumoconiosis. Pulmonary heart disease and noncancerous respiratory disease rates rose in proportion to dust exposure. Cancer mortality overall was not increased among the miners or pottery workers. There was no increased risk of lung cancer, except among tin miners, and trends in risk of this cancer with increasing level of dust exposure were not significant. Risks of lung cancer were 22% higher among workers with than without silicosis. The findings indicate that respiratory disease continues to be an occupational hazard among Chinese miners and pottery workers, but that cancer risks are not as yet strongly associated with work in these dusty trades.
Air Pollutants, Occupational↗
Identification of novel loci affecting entry of Salmonella enteritidis into eukaryotic cells.
There are an estimated 2 million cases of salmonellosis in the United States every year. Unlike the incidence of many infectious diseases, the incidence of salmonellosis in the United States and other developed countries has been rising steadily over the past 30 years, and the disease now accounts for 10 to 15% of all cases of acute gastroenteritis in the United States. The infecting organism is ingested and must traverse the intestinal epithelium to reach its preferred site for multiplication, the reticuloendothelial system. Despite several recent studies, the genetic basis of the invasion process is poorly understood. An emerging theme from these studies is that wild-type Salmonella organisms probably have several chromosomal loci that are required for the most efficient level of invasion. In this study, we have identified and characterized 13 TnphoA insertion mutants of Salmonella enteritidis CDC5 that exhibit altered invasion phenotypes. The mutants were identified by screening a bank of TnphoA insertions in S. enteritidis CDC5str for their invasion phenotype in three tissue culture cell lines (HEp-2, CHO, and MDCK). These 13 mutants were separated into six classes based on their invasive phenotypes in the tissue culture cell lines. Several mutants were defective for entry of some cell lines but not for others, while two mutants (SM6 and SM7) were defective for entry into all three tissue culture cell lines. This suggests that Salmonella spp. may express more than one invasion pathway. Southern analysis and chromosomal mapping indicated that as many as nine chromosomal loci may contribute to the invasion phenotype. It is becoming clear that the invasive phenotype of Salmonella spp. is multifactorial and more complex than that of some other invasive members of the family Enterobacteriaceae.
Animals↗
Therapeutic radiation at a young age is linked to secondary thyroid cancer. The Late Effects Study Group.
We estimated the risk of thyroid cancer among 9170 patients who had survived 2 or more years after the diagnosis of a cancer in childhood. As compared with the general population, patients had a 53-fold increased risk (95% confidence interval, 34-80). Risk increased significantly with time since treatment for the initial cancer (P = 0.03). Detailed treatment data were obtained for 23 cases and 89 matched controls from the childhood cancer cohort. Sixty-eight % of the thyroid cancers arose within the field of radiation. Radiation doses to the thyroid of greater than 200 cGy were associated with a 13-fold increased risk (95% confidence interval, 1.7-104). The risk of thyroid cancer rose with increasing dose (P less than 0.001), but this was derived almost entirely from the increase from less than 200 to greater than 200 cGy. The risk of thyroid cancer did not decrease, however, at radiation doses as high as 6000 cGy.
Adolescent↗
Incidence of childhood cancer in twins.
The incidence of childhood cancer in twins was evaluated by linking a roster of 30,925 twins born in Connecticut (United States) between 1930 and 1969 with the Connecticut Tumor Registry. Cancer, exclusive of nonmelanoma skin cancer, was identified in 19 females and 12 males under 15 years of age. The incidence rate among twins was 7.9 cancers per 100,000 person-years (PY) overall, and 9.7 and 6.1 per 100,000 PYs for females and males, respectively. Four of 13 leukemias occurred in two female twin pairs, representing concordance rates of 18 percent overall and 29 percent for like-sex pairs, which are somewhat higher than values reported previously. The number of cancers expected was computed on the assumption that twins experienced the same sex-, age-, and calendar time-specific cancer rates as recorded for all Connecticut-born children. Because active follow-up of individuals was not conducted, an adjustment to person-years of observation was made to account for childhood mortality, including the high perinatal mortality characteristic of twins. Childhood cancer was 30 percent less frequent than expected (standardized incidence ratio [SIR] = 0.7; 95 percent confidence interval [CI] = 0.5-0.9), a deficit that is marginally greater than those found in previous studies. Both leukemia (SIR = 0.8; CI = 0.4-1.4), and all other cancers combined (SIR = 0.6; CI = 0.3-0.9) occurred less often than expected. The deficit was greater among males (SIR = 0.5; CI = 0.2-0.8) than among females (SIR = 0.9; CI = 0.5-1.4) and was especially pronounced among males younger than five years (SIR = 0.2; CI = 0.0-0.7). The data support the view that twins, particularly male twins, have a lower risk of childhood cancer than single-born children. Any added risk for twins associated with their greater frequency of exposure to prenatal X-rays appears to have been insufficient to offset an 'effect' of twinning per se. Possible explanations for this finding include (i) the low birthweight distribution of twins, or (ii) selective early mortality of twin fetuses or neonates who would otherwise have developed a clinical cancer.
Adolescent↗
Correlates of liver cancer mortality in China.
To provide clues to the causes of liver cancer in China, we studied the correlation of certain dietary and biochemical markers with liver cancer mortality across 65 Chinese counties. Mortality rates were significantly linked to the county-wide prevalence of hepatitis-B surface antigen positivity. Rates were also higher in counties with high plasma levels of total cholesterol and high consumption of liquor, rapeseed oil, and mouldy corn, while inverse associations were observed for wheat consumption. All of the observed associations, except those with cholesterol and rapeseed oil, were more pronounced in men than in women. No significant correlations with liver cancer mortality were found for consumption of several other foods; plasma levels of retinol, beta-carotene, alpha-tocopherol, selenium, zinc and ferritin; or urine levels of aflatoxin B1. Although causal inferences cannot be derived, this ecological study suggests that chronic infection with hepatitis-B virus contributes to the substantial variation in liver cancer mortality in China, and provides leads for further studies into the role of dietary and nutritional determinants.
Adult↗
Environmental determinants of lung cancer in Shenyang, China.
To investigate determinants of the high rates of lung cancer in Shenyang, an industrial city in north-eastern China, a case-control study was conducted. Interviews with 1249 lung cancer patients and 1345 population-based controls revealed that cigarette smoking was the main cause of lung cancer. Smoking accounted for 55% of the lung tumours in men and 37% in women. In addition, air pollution from coal-burning heating and cooking devices was significantly linked to lung cancer, with risks rising in proportion to duration of exposure to indoor pollutants. Measurement of benzo[a]pyrene revealed average wintertime levels in air that were nearly 60 times the recommended upper limit for US cities, with even higher concentrations indoors in traditional single-storey homes using coal-burning kang (stoves). Occupational factors were also involved, the risk being elevated by three fold among smelter workers. Soil levels of arsenic and other metals rose with increasing proximity to the Shenyang copper smelter, and elevated risks of lung cancer were found among men, but not women, living within 1 km of its central stacks. Prior nonmalignant lung disease was common and was reported more often among the lung cancer patients than among controls. The findings suggest that cigarette smoking and environmental pollutants combine to account for most of the excess risk of lung cancer in this population.
Adult↗
Indoor radon and lung cancer in China.
Radon has long been known to contribute to risk of lung cancer, especially in undergound miners who are exposed to large amounts of the carcinogen. Recently, however, lower amounts of radon present in living areas have been suggested as an important cause of lung cancer. In an effort to clarify the relationship of low amounts of radon with lung cancer risk, we placed alpha-track radon detectors in the homes of 308 women with newly diagnosed lung cancer and 356 randomly selected female control subjects of similar age. Measurements were taken after 1 year. All study participants were part of the general population of Shenyang, People's Republic of China, an industrial city in the northeast part of the country that has one of the world's highest rates of lung cancer in women. The median time of residence in the homes was 24 years. The median household radon level was 2.3 pCi/L of air; 20% of the levels were greater than 4 pCi/L. Radon levels tended to be higher in single-story houses or on the first floor of multiple-story dwellings, and they were also higher in houses with increased levels of indoor air pollution from coal-burning stoves. However, the levels were not higher in homes of women who developed lung cancer than in homes of controls, nor did lung cancer risk increase with increasing radon level. No association between radon and lung cancer was observed regardless of cigarette-smoking status, except for a nonsignificant trend among heavy smokers. No positive associations of lung cancer cell type with radon were observed, except for a nonsignificant excess risk of small cell cancers among the more heavily exposed residents. Our data suggest that projections from surveys of miners exposed to high radon levels may have overestimated the overall risks of lung cancer associated with levels typically seen in homes in this Chinese city. However, further studies in other population groups are needed to clarify the carcinogenic potential of indoor radon.
Adult↗
Lung cancer among women in north-east China.
A case-control study of lung cancer involving interviews with 965 female patients and 959 controls in Shenyang and Harbin, two industrial cities which have among the highest rates of lung cancer in China, revealed that cigarette smoking is the main causal factor and accounted for about 35% of the tumours among women. Although the amount smoked was low (the cases averaged eight cigarettes per day), the percentage of smokers among women over age 50 in these cities was nearly double the national average. Air pollution from coal burning stoves was implicated, as risks of lung cancer increased in proportion to years of exposure to 'Kang' and other heating devices indigenous to the region. In addition, the number of meals cooked by deep frying and the frequency of smokiness during cooking were associated with risk of lung cancer. More cases than controls reported workplace exposures to coal dust and to smoke from burning fuel. Elevated risks were observed for smelter workers and decreased risks for textile workers. Prior chronic bronchitis/emphysema, pneumonia, and recent tuberculosis contributed significantly to lung cancer risk, as did a history of tuberculosis and lung cancer in family members. Higher intake of carotene-rich vegetables was not protective against lung cancer in this population. The findings were qualitatively similar across the major cell types of lung cancer, except that the associations with smoking and previous lung diseases were stronger for squamous/oat cell cancers than for adenocarcinoma of the lung.
Adult↗
Smoking, air pollution, and the high rates of lung cancer in Shenyang, China.
A case-control study involving interviews with 1,249 patients with lung cancer and 1,345 population-based controls was conducted in Shenyang, an industrial city in northeastern China, where mortality rates are high among men and women. Cigarette smoking was found to be the principal cause of lung cancer in this population, accounting for 55% of the lung cancers in males and 37% in females. The attributable risk percentage among females is high compared to elsewhere in China, largely because of a higher prevalence of smoking among women. After adjustment for smoking, there were also significant increases in lung cancer risk associated with several measures of exposure to air pollutants. Risks were twice as high among those who reported smoky outdoor environments, and increased in proportion to years of sleeping on beds heated by coal-burning stoves (kang), and to an overall index of indoor air pollution. Threefold increases in lung cancer risk were found among men who worked in the nonferrous smelting industry, where heavy exposures to inorganic arsenic have been reported. The associations with both smoking and indoor air pollution were stronger for squamous cell and small cell carcinomas than for adenocarcinoma of the lung. Risks due to smoking or air pollution were not greatly altered by adjustment for consumption of fresh vegetables or sources of beta carotene or retinol, prior chronic lung diseases, or education level. The findings suggest that smoking and environmental pollution combine to account for the elevated rates of lung cancer mortality in Shenyang.
Adenocarcinoma↗
Occupation and leukemia: response to Dr. William E. Morton.
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Health Occupations↗
The Danish case-control study of cutaneous malignant melanoma. III. Hormonal and reproductive factors in women.
The relationship between cutaneous malignant melanoma in women and reproductive and hormonal factors was investigated in a population-based case-control study including a total of 280 cases and 536 controls from East Denmark. Patients with lentigo maligna melanoma were not included. No association was found between risk of melanoma and age at menarche, duration of menstrual life, age at natural menopause, age at first pregnancy, or number of pregnancies, live births or miscarriages. There was no evidence of an association between melanoma and use, duration of use or type of oral contraceptives. The use of menopausal replacement therapy was not a risk factor for melanoma. There was no difference in risk associated with hormonal factors between superficial spreading melanoma and nodular melanoma. Our findings suggest that neither reproductive nor hormonal factors increase the risk of melanoma in women in Denmark.
Contraceptives, Oral↗