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Biomedical subjects

T Kauppinen

Publications and source records attributed to T Kauppinen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cancer risk in laboratory workers: an emphasis on biological research.

BACKGROUND: At the end of the 1980s, several cancer clusters were observed in biological research laboratories. Over time, biological research and the technologies used have been diverse and have involved a wide range of mutagenic or carcinogenic chemical, physical and biological agents. METHODS: We reviewed 45 published studies on cancer risk among biological research personnel and workers in closely related fields, and numerous reports based on routinely collected data. RESULTS: Biological research could be associated with an elevated risk for pancreatic cancer, brain tumors, and certain hemopathies. A common limitation of available studies was low statistical power and the absence or inaccuracy of data on individual past exposure. CONCLUSIONS: Overall, this study suggests a low overall risk of cancer, albeit a higher risk may be suggested for cancers of the pancreas (risk ratios ranging from 0.5 to 6.3) and brain (0.7-9.4), and for non-Hodgkin's lymphoma (0.6-51.5). We suggest ways in which multiple past exposures could be assessed more precisely and emphasize a pressing need to take into account known confounders.

Biological Science Disciplines↗
PubMed2000

Improvement of brain perfusion SPET using iterative reconstruction with scatter and non-uniform attenuation correction.

Filtered back-projection (FBP) is generally used as the reconstruction method for single-photon emission tomography although it produces noisy images with apparent streak artefacts. It is possible to improve the image quality by using an algorithm with iterative correction steps. The iterative reconstruction technique also has an additional benefit in that computation of attenuation correction can be included in the process. A commonly used iterative method, maximum-likelihood expectation maximisation (ML-EM), can be accelerated using ordered subsets (OS-EM). We have applied to the OS-EM algorithm a Bayesian one-step late correction method utilising median root prior (MRP). Methodological comparison was performed by means of measurements obtained with a brain perfusion phantom and using patient data. The aim of this work was to quantitate the accuracy of iterative reconstruction with scatter and non-uniform attenuation corrections and post-filtering in SPET brain perfusion imaging. SPET imaging was performed using a triple-head gamma camera with fan-beam collimators. Transmission and emission scans were acquired simultaneously. The brain phantom used was a high-resolution three-dimensional anthropomorphic JB003 phantom. Patient studies were performed in ten chronic pain syndrome patients. The images were reconstructed using conventional FBP and iterative OS-EM and MRP techniques including scatter and nonuniform attenuation corrections. Iterative reconstructions were individually post-filtered. The quantitative results obtained with the brain perfusion phantom were compared with the known actual contrast ratios. The calculated difference from the true values was largest with the FBP method; iteratively reconstructed images proved closer to the reality. Similar findings were obtained in the patient studies. The plain OS-EM method improved the contrast whereas in the case of the MRP technique the improvement in contrast was not so evident with post-filtering.

Brain↗
PubMed2000

Relationships between hostility and physiological coronary heart disease risk factors in young adults: the moderating influence of depressive tendencies.

BACKGROUND: We examined whether the relationships between hostility and physiological coronary heart disease (CHD) risk factors differ as a function of depressive tendencies (DT). METHODS: The participants were 672 randomly selected healthy young adults who self-reported their hostility (anger, cynicism, and paranoia) and DT. The physiological CHD risk factors studied were systolic blood pressure, diastolic blood pressure, body-mass index, serum high-density lipoprotein cholesterol, serum low-density lipoprotein cholesterol and serum triglycerides. RESULTS: We found that hostility was negatively associated with the physiological CHD risk factors among individuals exhibiting high DT while hostility was positively associated with, or unrelated to, the physiological risk factors among individuals showing low DT. The Hostility x DT interaction explained 2 to 5 % of the variance in the physiological parameters. CONCLUSION: The findings suggest that DT have a moderating influence on the relationships between hostility and CHD risk. Despite the established risk factor status of hostility, lack of anger and hostility, when combined with high DT, may represent the most severe exhaustion where the individual has given up. Disregard of this fact may explain some null findings in the research on hostility and CHD risk.

Adolescent↗
PubMed2000

Occupational exposure to carcinogens in the European Union.

OBJECTIVES: To construct a computer assisted information system for the estimation of the numbers of workers exposed to established and suspected human carcinogens in the member states of the European Union (EU). METHODS: A database called CAREX (carcinogen exposure) was designed to provide selected exposure data and documented estimates of the number of workers exposed to carcinogens by country, carcinogen, and industry. CAREX includes data on agents evaluated by the International Agency for Research on Cancer (IARC) (all agents in groups 1 and 2A as of February 1995, and selected agents in group 2B) and on ionising radiation, displayed across the 55 industrial classes. The 1990-3 occupational exposure was estimated in two phases. Firstly, estimates were generated by the CAREX system on the basis of national labour force data and exposure prevalence estimates from two reference countries (Finland and the United States) which had the most comprehensive data available on exposures to these agents. For selected countries, these estimates were then refined by national experts in view of the perceived exposure patterns in their own countries compared with those of the reference countries. RESULTS: About 32 million workers (23% of those employed) in the EU were exposed to agents covered by CAREX. At least 22 million workers were exposed to IARC group 1 carcinogens. The exposed workers had altogether 42 million exposures (1.3 mean exposures for each exposed worker). The most common exposures were solar radiation (9.1 million workers exposed at least 75% of working time), environmental tobacco smoke (7.5 million workers exposed at least 75% of working time), crystalline silica (3.2 million exposed), diesel exhaust (3.0 million), radon (2.7 million), and wood dust (2.6 million). CONCLUSION: These preliminary estimates indicate that in the early 1990s, a substantial proportion of workers in the EU were exposed to carcinogens.

Carcinogens↗
PubMed2000

Statistical modelling of the determinants of historical exposure to bitumen and polycyclic aromatic hydrocarbons among paving workers.

INTRODUCTION: An industrial hygiene database has been constructed for the exposure assessment in a study of cancer risk among asphalt workers. AIM: To create models of bitumen and polycyclic aromatic hydrocarbons (PAH) exposure intensity among paving workers. METHODS: Individual exposure measurements from pavers (N = 1581) were collected from 8 countries. Correlation patterns between exposure measures were examined and factors affecting exposure were identified using statistical modelling. RESULTS: Inhalable dust appeared to be a good proxy of bitumen fume exposure. Bitumen fume and vapour levels were not correlated. Benzo(a)pyrene level appeared to be a good indicator of PAH exposure. All exposures steadily declined over the last 20 years. Mastic laying, re-paving, surface dressing, oil gravel paving and asphalt temperature were significant determinants of bitumen exposure. Coal tar use dictated PAH exposure levels. DISCUSSION: Bitumen fume, vapour and PAH have different determinants of exposure. For paving workers, exposure intensity can be assessed on the basis of time period and production characteristics.

Databases, Factual↗
PubMed2000

Risk of pancreatic cancer and occupational exposures in Spain. PANKRAS II Study Group.

The objective of the study was to analyse the relationship between occupational exposures and risk of pancreatic cancer. Incident cases of pancreatic cancer and hospital controls were prospectively identified and interviewed during the hospital stay. Occupational history was obtained by direct interview with the patient, and was available for 164 (89%) of 185 pancreatic cancer cases, and 238 (90%) of 264 controls. Two industrial hygienists evaluated exposures to 22 suspected carcinogens previously associated with pancreatic cancer. Occupational exposures were also assessed using the Finnish job-exposure matrix (FINJEM). For each type of pesticide group, moderately increased odds ratios (OR) were apparent in the high-intensity category, highest for arsenical pesticides (OR=3.4; 95% CI 0.9-12.0), and 'other pesticides' (OR=3.17; 95% CI 1.1-9.2). ORs for aniline derivatives, and dyes and organic pigments, were also higher for high-intensity exposure, and increased when lagged and restricted to long duration of exposure. ORs above 3 were observed for the following agents evaluated by FINJEM: pesticides, benzo[a]pyrene, lead, volatile sulphur compounds, and sedentary work. Whilst generally negative, results lend moderate support to the hypothesis of an association between exposure to some pesticides and pancreatic cancer. Larger studies could address the potential for these compounds to modify the carcinogenic risk of other environmental exposures. Suggestive increases in risk from aniline derivatives, dyes and organic pigments, and benzo[a]pyrene may also deserve further attention.

Aged↗
PubMed2000

Nonuniform transmission in brain SPECT using 201Tl, 153Gd, and 99mTc static line sources: anthropomorphic dosimetry studies and influence on brain quantification.

UNLABELLED: Nonuniform attenuation correction in brain SPECT can be done routinely by means of additional gamma transmission CT (TCT) measurements, using different commercially available line-source isotopes, 201Tl, 153Gd, and 99mTc are among the most commonly used isotopes, depending on practical and cost-effectiveness issues. We have measured additional radiation burden from static uncollimated brain SPECT transmission sources for these isotopes. The influence of the transmission isotope on brain quantification was also measured and compared with uniform attenuation correction for phantom and human data. Full iterative transmission and emission reconstruction were compared with filtered backprojection techniques. METHODS: Rod sources with 201Tl, 153Gd, and 99mTc were used on a triple-head gamma camera. Dosimetry was performed using LiF TLD-100 pellets and an anthropomorphic RANDO phantom. Effective dose equivalents were calculated on the basis of measured and extrapolated absorbed doses. For brain activity measurements, a Hoffman phantom was used. Images were corrected for scatter (triple-energy window) and were reconstructed by Chang attenuation correction and filtered backprojection as well as full iterative reconstruction (ordered-subsets expectation maximization [OSEM]). To study the effect of inhomogeneous bone attenuation, realistic measurements were performed on 10 young, healthy volunteers with 153Gd TCT. After stereotactic image realignment, a volume-of-interest analysis normalized to total counts was performed. RESULTS: Brain SPECT-TCT using 201Tl, 153Gd, and 99mTc produced total effective dose-rate equivalents of 50.3 +/- 11.2, 32.0 +/- 2.7, and 71.1 +/- 7.1 microSv/GBq x h, respectively, representing dose equivalents of 18.6, 11.9, and 26.3 microSv for a typical 20-min brain SPECT scan at maximal used source strength. Standardized quantification resulted in insignificant differences between the isotopes and methods (Chang versus OSEM) used for nonuniform correction. Iterative reconstruction enhanced image contrast and provided more accurate gray-to-white matter ratios. Between nonuniform and uniform attenuation with an optimized attenuation coefficient, slight central discrepancies were found for volunteer studies. Significantly lower intersubject variation was found for nonuniform corrected values in infratentorial and posterior brain regions. CONCLUSION: Brain transmission scanning using 201Tl, 153Gd, or 99mTc results in limited effective radiation dose equivalents compared with the typical radiation burden. Relative brain perfusion quantification is not significantly different for the various nonuniform TCT isotopes. Iterative reconstruction improves gray-to-white contrasts but has no significant influence on brain perfusion semiquantification. Nonuniform attenuation correction decreases intersubject variability in the posterior brain regions that were compared, which may lead to improved sensitivity toward clinical applications.

Adult↗
PubMed1999

Breast cancer and occupational exposures in women in Finland.

BACKGROUND: The etiology of breast cancer is not fully understood. Environmental and occupational exposures may contribute to breast cancer risk. METHODS: We linked 324 job titles from the 1970 census of 892,591 Finnish women with incidence of breast cancer (23,638 cases) during 1971-1995. We converted job titles to 31 chemical and two ergonomic agents through a measurement-based, period-specific, national job-exposure matrix. Poisson regression models were fit to the data, with adjustment for birth cohort, follow-up period, socioeconomic status, mean number of children, mean age at first delivery, and turnover rate. RESULTS: For premenopausal breast cancer, medium/high level of occupational exposure to ionizing radiation was associated with a standardized incidence ratio (SIR) of 1.3 (95% confidence interval (CI) 0.7-2.5; trend P = 0.03). For postmenopausal breast cancer, we found on SIR of 1.2 (1.1-1.3) for low level and 1.4 (1.1-1.8) for medium/high level of ionizing radiation (trend P = 0.001); and an SIR 1.3 (1.1-1.7) for medium/high levels of both asbestos and man-made vitreous fibers. Aromatic hydrocarbon solvents showed a significant trend for a modest excess of postmenopausal breast cancer. CONCLUSIONS: Our study indicates that occupational exposure to ionizing radiation may be associated with an increased risk of female breast cancer. High-quality studies on environmental and occupational etiology of breast cancer are needed for further elucidation of risk factors.

Adult↗
PubMed1999

Ovarian cancer and occupational exposures in Finland.

BACKGROUND: No single occupational or environmental agent has been established as causing ovarian cancer, existing studies often being based on ecologic or proportional mortality data in which potential confounders related to reproductive history have not been taken into account. METHODS: This study linked 324 job titles of occupationally active Finnish women (n = 892,591) at 1970 census with incidence of ovarian cancer (Finnish Cancer Registry, 5,072 cases) during 1971-1995 (over 15 million person-years). The job titles were converted into indicators of exposure to 33 agents, using a national job-exposure matrix based on measurements and surveys (FINJEM). Poisson regression analyses were performed with stratification by birth cohort, follow-up period, and socioeconomic status, and adjusted for mean number of children, mean age at first delivery, and turnover rate for each job title. RESULTS: We found indications of elevated risks for aromatic hydrocarbon solvents (standardized incidence ratio 1.3 (95% CI 1.0-1.7), leather dust (1.4; 0.7-2.7), man-made vitreous fibers (1.3; 0.9-1.8), and high levels of asbestos (1.3; 0.9-1.8), and diesel (1.7; 0.7-4.1), and gasoline (1.5; 1.0-2.0) engine exhausts). Previously reported findings for hairdressers and women in the printing industry were supported in our data, but not for women in dry cleaning jobs. CONCLUSIONS: Given the various drawbacks in linkage studies and job-exposure matrices, the excesses found in this study need confirmation in individual-level studies.

Adult↗
PubMed1999

Incidence of cancer among Finnish patients with asbestos-related pulmonary or pleural fibrosis.

OBJECTIVES: To study the asbestos-associated risk of lung cancer according to the histological type of cancer, the time of and time since diagnosis of asbestosis, the asbestos-associated risk for cancers other than lung cancer or mesothelioma, and the predictive value of asbestos-related pleural abnormalities as regards the risk of cancer. METHODS: Finnish patients with asbestosis (n = 1,376) or asbestos-related benign pleural disease (n = 4,887) notified as an occupational disease since 1964 were followed-up through the Finnish Cancer Registry for cancer in 1967-95. RESULTS: Compared with the total cancer incidence in Finland, men with asbestosis had a raised risk of lung cancer (standardized incidence ratio [SIR] = 6.7; 95% confidence interval [CI] = 5.6-7.9), mesothelioma (SIR = 32, CI = 14-60) and cancer of the larynx (SIR = 4.2, CI = 1.4-9.8). The risk of lung cancer was similarly raised for all histological types of lung cancer (the highest in insulators) and did not change markedly over time of notification or duration of follow-up. Men with benign pleural disease had a raised risk of mesothelioma (SIR = 5.5, CI = 1.5-14) and a slightly elevated risk of lung cancer (SIR = 1.3, CI = 1.0-1.8). Among women with asbestosis, significant excess was found for lung cancer and mesothelioma. CONCLUSION: Asbestosis and asbestos-related benign pleural disease seem to possess different predictive values as regards the risk of lung cancer.

Adult↗
PubMed1999

Evaluation of scatter correction using a single isotope for simultaneous emission and transmission data. Phantom and clinical patient studies.

UNLABELLED: Photon scatter is one of the most important factors degrading the quantitative accuracy of SPECT images. Many scatter correction methods have been proposed. The single isotope method was proposed by us. AIM: We evaluate the scatter correction method of improving the quality of images by acquiring emission and transmission data simultaneously with single isotope scan. METHOD: To evaluate the proposed scatter correction method, a contrast and linearity phantom was studied. Four female patients with fibromyalgia (FM) syndrome and four with chronic back pain (BP) were imaged. Grey-to-cerebellum (G/C) and grey-to-white matter (G/W) ratios were determined by one skilled operator for 12 regions of interest (ROIs) in each subject. RESULTS: The linearity of activity response was improved after the scatter correction (r = 0.999). The y-intercept value of the regression line was 0.036 (p < 0.0001) after scatter correction and the slope was 0.954. Pairwise correlation indicated the agreement between nonscatter corrected and scatter corrected images. Reconstructed slices before and after scatter connection demonstrate a good correlation in the quantitative accuracy of radionuclide concentration. G/C values have significant correlation coefficients between original and corrected data. CONCLUSION: The transaxial images of human brain studies show that the scatter correction using single isotope in simultaneous transmission and emission tomography provides a good scatter compensation. The contrasts were increased on all 12 ROIs. The scatter compensation enhanced details of physiological lesions.

Back Pain↗
PubMed1999

Health and hazard surveillance--needs and perspectives.

Health and hazard surveillance is the on-going collection, analysis, evaluation, and dissemination of information aimed at improving the health, work ability, and well-being of workers. Hazard surveillance supplemented by quantitative risk assessment is the most prevention-oriented domain of surveillance. However, information on exposures and stress factors is often lacking. Computer-assisted expert judgment is a new approach to improve knowledge on hazards. Surveillance of work organizations and psychosocial factors is a challenging area which still requires research. Statistics on occupational injuries and diseases are available, but nonspecific coding and insufficient interpretation often limit their usefulness. Systematic surveys of new types of cases and the linking of different data bases are becoming more feasible. Methodological work is needed to develop indicators of work ability and work-related symptoms. Among the many possibilities to develop surveillance are the use of information technology, the application of hazard communication principles, and the development of practical aids for surveillance at the company level.

Data Collection↗
PubMed1998

From cross-tabulations to multipurpose exposure information systems: a new job-exposure matrix.

Previous job-exposure matrices (JEM) have usually cross-tabulated classified exposure information by chemical agent and occupational class. A new Finnish job-exposure matrix (FINJEM) was constructed for exposure assessment in large register-based studies. Unlike most other JEMs, FINJEM was designed to contain definitions, inferences, exposure data, and references. This documentation enables FINJEM to be applied also as a general exposure information system for hazard control, risk quantification and hazard surveillance. The system includes, e.g., workforce data, and it provides information on the numbers of exposed workers in Finland by agent, occupation, and level of exposure. The exposures of FINJEM cover major physical, chemical, microbiological, ergonomic, and psychosocial factors. The assessment period is 1945-1997, divided into several subperiods. Exposure is described by the prevalence of exposure and the level of exposure among the exposed, both estimated mainly on continuous scales. The user may also define the final criteria of exposure, and thereby influence the magnitude of misclassification.

Environmental Monitoring↗
PubMed1998

Exposure to dioxin and nonneoplastic mortality in the expanded IARC international cohort study of phenoxy herbicide and chlorophenol production workers and sprayers.

The authors studied noncancer mortality among phenoxyacid herbicide and chlorophenol production workers and sprayers included in an international study comprising 36 cohorts from 12 countries followed from 1939 to 1992. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin or higher chlorinated dioxins (TCDD/HCD) was discerned from job records and company questionnaires with validation by biologic and environmental measures. Standard mortality ratio analyses suggested a moderate healthy worker effect for all circulatory diseases, especially ischemic heart disease, among both those exposed and those not exposed to TCDD/HCD. In Poisson regression analyses, exposure to TCDD/HCD was not associated with increased mortality from cerebrovascular disease. However, an increased risk for circulatory disease, especially ischemic heart disease (rate ratio [RR] 1.67, 95% confidence interval [Cl] 1.23-2.26) and possibly diabetes (RR 2.25, 95% Cl 0.53-9.50), was present among TCDD/HCD-exposed workers. Risks tended to be higher 10 to 19 years after first exposure and for those exposed for a duration of 10 to 19 years. Mortality from suicide was comparable to that for the general population for all workers exposed to herbicides or chlorophenols and was associated with short latency and duration of exposure. More refined investigations of the ischemic heart disease and TCDD/HCD exposure association are warranted.

Adult↗
PubMed1998

Occurrence, trends and environment etiology of pancreatic cancer.

This review summarizes data on the occurrence, the trends, and the life-style, environmental, occupational and genetic determinants of pancreatic cancer. Epidemiologic evidence implicates tobacco smoking as one cause. The evidence regarding alcohol consumption is inconsistent. Although both positive and inconclusive findings are encountered, the bulk of the evidence on coffee consumption is negative. Fat intake is linked with obesity and diabetes mellitus, which are risk factors for pancreatic cancer. Fruit and vegetable consumption appears to be protective. No occupational or environmental agent has been confirmed to increase the risk, but epidemiologic evidence is inconsistent, Little is known about the role of genetic polymorphisms of metabolic enzymes in pancreas carcinogenesis. Pancreatic cancer shows high rates of mutations of Ki-ras and losses or mutations of tumor suppressor genes (p53, p16INK4A, and SMAD4/DPC-4). Ki-ras mutations have been associated with life-style factors in relation to pancreatic cancer, but the evidence is still scant and inconsistent.

Female↗
PubMed1997

Cancer mortality in workers exposed to phenoxy herbicides, chlorophenols, and dioxins. An expanded and updated international cohort study.

The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dioxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) was higher than expected from national mortality rates. Mortality from all malignant neoplasms (710 deaths; SMR = 1.12, 95% CI 1.04-1.21), non-Hodgkin's lymphoma (24 deaths; SMR = 1.39, 95% CI 0.89-2.06), and lung cancer (225 deaths; SMR = 1.12, 95% CI 0.98-1.28) was slightly elevated. Risks for all neoplasms, for sarcomas, and for lymphomas increased with time since first exposure. In workers exposed to phenoxy herbicides with minimal or no contamination by TCDD and higher chlorinated dioxins, mortality from all neoplasms (398 deaths; SMR = 0.96, 95% CI 0.87-1.06), non-Hodgkin's lymphoma (9 deaths; SMR = 1.00), and lung cancer (148 deaths; SMR = 1.03) was similar to that expected, and mortality from soft-tissue sarcoma was slightly elevated (2 deaths; SMR = 1.35). In a Poisson regression analysis, workers exposed to TCDD or higher chlorinated dioxins had an increased risk for all neoplasms (rate ratio = 1.29, 95% CI 0.94-1.76) compared with workers from the same cohort exposed to phenoxy herbicides and chlorophenols but with minimal or no exposure to TCDD and higher chlorinated dioxins. These findings indicate that exposure to herbicides contaminated with TCDD and higher chlorinated dioxins may be associated with a small increase in overall cancer risk and in risk for specific cancers.

Australia↗
PubMed1997

International data base of exposure measurements in the pulp, paper and paper product industries.

An international data base of exposure measurements in the pulp, paper and paper product industries was constructed to be used in exposure assessment for epidemiology studies and hazard control. Industrial hygiene and biological monitoring data were collected from countries participating in the multicentric study of the International Agency for Research on Cancer. Each measurement was characterized by country, mill type and number, department, job, agent measured, sampling method, measurement result in the standard unit, duration and date of sampling, assessment of representativeness, measurer, purpose of measurements, and remarks (e.g. on measurement sites and biases). Over 31,000 measurement results on 246 different chemical agents from 13 countries were available from pulp (45% of measurements), paper/paperboard/recycling (12%) and paper product (11%) mills or from their non-production departments (23%). Most measurements (82%) were carried out after 1980. The most frequently measured group of agents was inorganic gases (35%), followed by organic compounds (25%), solvents (18%), mineral dusts (12%), metals (6%) and bioaerosols (3%). Over 90% of the measurements were without an obvious bias, but their true representativeness is difficult to assess. Concentrations of various agents, including sulfur dioxide, chlorine dioxide, carbon monoxide, nitrogen dioxide, ozone, ammonia, formaldehyde and some solvents, often exceeded current occupational exposure limits. This data base summarizes a great deal of previously unpublished exposure data, provides a unique opportunity to study exposure patterns at the international level and identifies exposure situations that require further attention and investigation.

Bias↗