PubMed HealthSearch

Biomedical subjects

A Andersen

Publications and source records attributed to A Andersen.

At least 19 recordsLinked to original sources

Is there an association between an increase in c-myc RNA steady state levels and c-myc methylation in HL-60 cells treated with 3-deaza-(+/-)-aristeromycin, an indirect inhibitor of methylation?

Alteration in gene expression of the proto-oncogene c-myc in HL-60 cells is associated with differentiation of these cells. We have studied the steady state levels of c-myc transcripts, the levels of transmethylation metabolites S-adenosylmethionine and S-adenosyl-homocysteine and the methylation pattern of the c-myc gene after treatment of HL-60 cells with the transmethylation inhibitor and granulocytic inducer, 3-deaza-(+/-)-aristeromycin. A transient increase in c-myc RNA levels after 45 min of drug exposure was observed which was accompanied by changes in the ratio of transmethylation metabolites in both whole cells and nuclei. The changes in transmethylation metabolites in whole cells, although compatible with levels frequently associated with hypomethylation of cellular components, caused no changes in methylation of c-myc DNA sequences of the HL-60 cells as detected by HpaII or MspI digestion and Southern blotting.

Adenosine

Incidence of cancer in Norwegian workers potentially exposed to electromagnetic fields.

The risk of cancer was investigated in a cohort of 37,945 male Norwegian electrical workers for whom information on job description was collected from 1960 census data and linked to the 1970 census data. The standardized incidence ratio was calculated for all cancer sites in the overall cohort by comparison with national incidence rates for economically active men at the 1960 census. The standardized incidence ratios for cancers of the breast, pleura (mesothelioma), larynx, and bladder and for soft tissue sarcoma were elevated, while those for non-Hodgkins and Hodgkins lymphoma were lower. The standardized incidence ratio for leukemia for electrical workers with 10 or more economically active years was 1.41. The standardized incidence ratio for brain tumors in this subgroup of electrical workers was 1.14. These results from a large, national, population-based study at the Cancer Registry of Norway give support to previous findings of a possible association between electrical work and the risk of leukemia.

Adult

A cohort study on cancer incidence in offspring of male printing workers.

We used multistep register linkage to measure the occurrence of cancer in offspring of male members of the Oslo unions of printers. A file of their children was established through linkage with the Central Population Register. Children born 1950-1987 (N = 12,440) were traced for cancer during 1965-1987 in the Cancer Registry of Norway (193,406 person-years). We found 33 cases of cancer. The standardized incidence ratio was near expected for person-years after age 14 (25 cases observed) but lower than expected for person-years in the age group 0-14 years (eight cases observed, standardized incidence ratio 0.58, 95% confidence interval 0.25-1.14). This negative association was stronger when more precise criteria for time of exposure were applied, especially for children 0-14 years with fathers in categories exposed to lead 1 year before the child's birth. Methodologic problems with this approach are nondifferential exposure misclassification and the need for large data sets. The method could serve as an alternative to the case-control design in reproductive epidemiology.

Adolescent

Lung cancer mortality among workers in the European production of man-made mineral fibers--a Poisson regression analysis.

One hundred and eighty-one lung cancer deaths among workers during 301,085 person-years in European man-made mineral fiber production between 1930-1955 and 1982 were analyzed according to Poisson regression models including age, calendar period, country, and exposure variables. Time since first employment was the variable most strongly associated with lung cancer risk in both the rock-slag wool and glass wool subcohorts. Workers in the early technological phase were at higher risk than those in other categories, particularly in rock-slag wool production. No clear trend with duration of employment was suggested. No major changes occurred in the interpretation of the results when workers with less than one year of employment or less than 20 years since first exposure were excluded. The original results, based on analyses for standardized mortality ratios, were confirmed, and workers with a short duration of employment or a short time since first employment did not need to be excluded from the analysis.

Air Pollutants, Occupational

Cancer incidence among creosote-exposed workers.

Cancer incidence was studied among 922 creosote-exposed impregnators at 13 plants in Sweden and Norway. The subjects had been impregnating wood (eg, railroad cross-ties and telegraph poles), but no data on individual exposures were available. The study population was restricted to men employed during the period 1950-1975, and their cancer morbidity was checked through the cancer registries. The total cancer incidence was somewhat lower than expected, 129 cases versus 137 expected [standardized incidence ratio (SIR) 0.94]. Increased risks in both countries combined were observed for lip cancer (SIR 2.50, 95% confidence interval (95% CI) 0.81-5.83), skin cancer (SIR 2.37, 95% CI 1.08-4.50), and malignant lymphoma (SIR 1.9, 95% CI 0.83-3.78). Exposure to sunlight may have contributed to the risk of lip and skin cancer. The small number of cancer cases does not permit valid conclusions. The findings indicate that impregnating wood with creosote in earlier decades increased the risk of skin cancer.

Cohort Studies

The risk of cancer at all sites following gastric operation for benign disease. A cohort study of 4,224 patients.

This report represents the results of a historical cohort analysis of 3,360 males and 864 females who had a gastric resection or gastroenterostomy for benign disease between 1990 and 1969. Within the period 1970 to 1988 the cohort was cross-checked with the data files at the Cancer Registry of Norway to identify the patients in whom cancer had been diagnosed. When analyzed according to cancer sites, increased risk was recorded for the oropharynx, stomach, colon, pancreas, liver, biliary tract, larynx, lungs, urinary bladder and non--melanomatous cancers of the skin in males. In females, increased risk was only observed for the oropharynx, but was close to a statistically significant level also for cancer of the stomach. A lower number of tumors of the central nervous system than expected was observed in both males and females. The increased risk of cancer of the lungs, larynx and urinary bladder in males can be regarded as evidence of the high prevalence of smokers in the cohort. We suggest that the increased risk of cancer of digestive organs is mainly related to life-style factors, particularly tobacco-specific nitrosamines whose effect is enhanced by surgical sequelae.

Cohort Studies

Cancer incidence among asbestos-exposed chemical industry workers: an extended observation period.

A previous study on the incidence of cancer in a cohort of 286 asbestos-exposed electrochemical industry workers observed from 1953 through 1980 has been extended with another 8 years of follow-up. The incidence of cancer was derived from the Cancer Registry of Norway, and the expected figures were calculated by a life table method. During the extended follow-up period from 1981 through 1988, among the cohort members there were 12 new cancer cases versus 14.2 expected (SIR 85, 95% CI 44-158). In a lightly exposed sub-cohort, the extended follow-up revealed 4 cases of lung cancer or pleural mesothelioma (ICD, 7th revision 162-163) versus 1.6 cases expected (SIR 256, 95% CI71-654). In a heavily exposed sub-cohort, the corresponding figures were 3 and 0.5 (SIR 588, 95% CI 118-1,725).

Asbestos

Delayed gastrointestinal transit times in anorexia nervosa and bulimia nervosa.

Anorectic and bulimic patients frequently report symptoms of constipation, bloating, and abdominal pain suggestive of abnormal gastrointestinal motility or transit. However, except for studies of gastric emptying, gastrointestinal motility and transit in these eating disorders have not been investigated. Ten anorectic and 18 bulimic inpatients were compared with 10 healthy controls. Whole-gut transit was tested by the radiopaque marker technique, and mouth-to-cecum transit time was assessed by the lactulose breath test. All anorectics and 67% of bulimics complained of constipation. Whole-gut transit time was significantly delayed in both anorectics (66.6 +/- 29.6 hours) and bulimics (70.2 +/- 32.4 hours) compared with controls (38.0 +/- 19.6 hours). Mouth-to-cecum transit time also tended to be longer in anorectics (109.0 +/- 33.5 minutes) and bulimics (106.2 +/- 24.5 minutes) than in controls (84.0 +/- 27.7 minutes), but these differences were not statistically significant. Delayed transit could contribute to or perpetuate the eating disorders by (a) causing the patient to feel bloated, thereby exacerbating fear of fatness, or (b) causing rectal distention, which may reflexly inhibit gastric emptying.

Adolescent

Nutritional value of yeast for Dermatophagoides pteronyssinus (Acari: Epidermoptidae) and the antigenic and allergenic composition of extracts during extended culturing.

Cultures of European house dust mite, Dermatophagoides pteronyssinus (Trouessart), were evaluated with respect to yeast nutritional value, together with an assessment of the antigenic and allergenic composition. CIE analysis of extracts illustrated that yeast contributes many antigens throughout the rearing period. However, there is an indication of the consumption of only one particular yeast antigen by the mites. Total protein content profile of the mite cultures is shown in addition to the total allergen activity (RAST determinations). The allergenic activity of the extracts steadily increased during the mite culturing period; this may be due to the accumulation of fecal particles containing the major allergen.

Allergens

A historical prospective study of European stainless steel, mild steel, and shipyard welders.

A multicentre cohort of 11,092 male welders from 135 companies located in nine European countries has been assembled with the aim of investigating the relation of potential cancer risk, lung cancer in particular, with occupational exposure. The observation period and the criteria for inclusion of welders varied from country to country. Follow up was successful for 96.9% of the cohort and observed numbers of deaths (and for some countries incident cancer cases) were compared with expected numbers calculated from national reference rates. Mortality and cancer incidence ratios were analysed by cause category, time since first exposure, duration of employment, and estimated cumulative dose to total fumes, chromium (Cr), Cr VI, and nickel (Ni). Overall a statistically significant excess was reported for mortality from lung cancer (116 observed v 86.81 expected deaths, SMR = 134). When analysed by type of welding an increasing pattern with time since first exposure was present for both mild steel and stainless steel welders, which was more noticeable for the subcohort of predominantly stainless steel welders. No clear relation was apparent between mortality from lung cancer and duration of exposure to or estimated cumulative dose of Ni or Cr. Whereas the patterns of lung cancer mortality in these results suggest that the risk of lung cancer is higher for stainless steel than mild steel welders the different level of risk for these two categories of welding exposure cannot be quantified with precision. The report of five deaths from pleural mesothelioma unrelated to the type of welding draws attention to the risk of exposure to asbestos in welding activities.

Europe

A collaborative study of cancer incidence and mortality among vinyl chloride workers.

A large European multicentric cohort study has been coordinated by the International Agency for Research on Cancer with the objectives of investigating the dose-response relationship between liver cancer and exposure to vinyl chloride and assessing cancer risk for sites other than the liver. A nearly threefold increase in liver cancer was detected on the basis of 24 observed deaths and 8.4 expected (standardized mortality ratio 286, 95% confidence interval 186-425). The excess from liver cancer was clearly related to time since first exposure, duration of employment, and estimated ranked and quantitative exposures. Other cancer sites investigated on the basis of a priori hypotheses were either not in excess (lung) or apparently unrelated to the exposure variables (brain and lymphoma).

Adult

Risk for cancer of the urinary bladder among hairdressers in the Nordic countries.

Several studies have indicated an increased risk for cancer of the urinary bladder among hairdressers. In a Danish linkage between census data and cancer register data both male and female hairdressers have an elevated risk for bladder cancer. The risk for lung cancer is close to unity, indicating that occupational factors rather than smoking, may be responsible for the increased risk for bladder cancer among hairdressers. To evaluate this hypothesis we conducted a collaborative analysis of data from similar linkages in Finland, Norway, and Sweden. The combination of high risk for bladder cancer and low or no risk for lung cancer was not found in the other Nordic countries; however, statistically significant increased risks for both bladder and lung cancer were found among male hairdressers in both Norway and Sweden. The relative risks for bladder cancer were of the same magnitude as the relative risks for lung cancer.

Adolescent

Morbidity and mortality in talc-exposed workers.

Cancer incidence and cause-specific mortality were studied in a male cohort of 94 talc miners and 295 talc millers, exposed to non-asbestiform talc with low quartz content. No excess risk was found compared with national age-specific incidence. Six cases of lung cancer occurred versus 6.49 expected (miners: observed 2, expected 1.27; millers: observed 4, expected 5.22). There were 3 deaths due to non-malignant respiratory disease against 10.9 expected (miners: observed 1, expected 2.5; millers: observed 2, expected 8.4). Mesothelioma, tuberculosis, or pneumoconiosis were not recorded as causes of death. Pneumoconiosis was noted as a contributory cause in three cases (silicosis two, talcosis one). Further follow-up will reduce any potential impact of "healthy worker" selection.

Cause of Death