Search PubMed⌕ Search

Biomedical subjects

I Jahn

Publications and source records attributed to I Jahn.

At least 19 recordsLinked to original sources
PubMed2006

Serum immunoglobulin free light chain assessment in rheumatoid arthritis and primary Sjogren's syndrome.

BACKGROUND: B cell activation may result in an increased secretion of immunoglobulin free light chains (FLCs) in autoimmune diseases. OBJECTIVE: To analyse serum FLC levels in patients with rheumatoid arthritis and in those with primary Sjögren's syndrome (pSS). PATIENTS AND METHODS: Blood samples were collected from 80 healthy blood donors, 50 patients with rheumatoid arthritis and 139 patients with pSS. Serum FLC level was measured using a new quantitative immunoassay. RESULTS: Mean (standard error (SE)) serum kappa and lambda FLC levels were significantly higher in patients with rheumatoid arthritis and in those with pSS than in controls (kappa : 18.9 (1.1) and 16.3 (1.4) v 10.5 (0.4) mg/l, p<0.001 and p = 0.001, respectively; lambda: 16.7 (1.2) and 19.3 (1.5) v 11.6 (0.6) mg/l, p<0.001 for both). 18 (36%) patients with rheumatoid arthritis and 31 (22.3%) patients with pSS had abnormal serum FLC levels (increased kappa or lambda levels and abnormal ratio of kappa:lambda). Serum kappa and lambda levels were correlated with other B cell activation markers in both diseases. FLC levels increased with disease activity, because, unlike total gammaglobulin and immunoglobulin G levels, they were significantly correlated with Disease Activity Score 28 in patients with rheumatoid arthritis (p = 0.004 for kappa, p = 0.05 for lambda) and with extraglandular involvement in pSS (p = 0.01 for kappa, p = 0.04 for lambda). CONCLUSION: FLC levels are increased and correlate with disease activity in patients with rheumatoid arthritis and in those with pSS, two diseases in which increased risk of lymphoma could result from persistent B cell activation and disease activity. Further studies are required to determine whether FLC assessment could represent a relevant biomarker for response to treatment (especially B cell depletion) and for the risk of lymphoma in autoimmune diseases.

Adult↗
PubMed2005

[Taking into consideration gender and sex. New chances to improve the quality of epidemiological and health research].

Researchers who apply for project funding at the European level or at German Federal Ministries must take into account the gender aspects of their proposals as well as in the realization of these projects (gender mainstreaming) more and more often. The promotion of gender equality in research and science is becoming a "mainstream" task as well as a sign of the quality of the project. In practice, however, the process of carrying out gender sensitive research must still gain momentum. This article focuses on central questions and problems: Which are the gender aspects of a certain subject? In what way do we have to design studies and research methods to be able to apprehend and discover gender aspects properly? Which strategies of evaluation are adequate? What is the best way to analyze, interpret, and communicate data? The basics will be clarified (e. g. terms like sex/gender, doing gender, the role of the "gender" category in the context of social differentiation, causes and forms of gender bias). In addition, methodological/methodical hints and instruments to avoid distortion due to the inadequate consideration of gender category in the course of research will be introduced (diagnostic brief-questionnaire according to Eichler, gender-matrix, five challenges according to Doyal, gender adequate speech and publication).

Data Interpretation, Statistical↗
PubMed2002

Asbestos fibreyears and lung cancer: a two phase case-control study with expert exposure assessment.

AIMS: To assess the cumulative effect of asbestos on lung cancer risk where the exposure is assessed by an expert rating. METHODS: 1678 male cases and controls were enrolled in a population based matched case-control study, focused on occupational risk factors, carried out in West Germany. The exposure to asbestos was computed as lifelong working hours. For a validation subsample of 164 matched pairs from this study the intensity of asbestos exposure was further assessed by a panel of experts in order to obtain an estimate of the cumulative exposure on a time by intensity scale (fibreyears). The information on duration of asbestos exposure in the original study was combined with the fibreyears following the two phase case control study paradigm. RESULTS: The number of exposed subjects in the validation subsample was 75 cases and 71 controls. The percentage of subjects with a cumulative exposure < or =1, 1 to < or =10, and >10 fibreyears was 16%, 15%, and 15% for the cases and 18%, 16%, and 9% respectively for the controls. The smoking adjusted odds ratios for the fibreyears based on an unconditional logistic regression were 0.81, 1.02, and 1.60 respectively with increasing exposure categories (not significant). The coefficient (beta) for a log transformed trend was 1.156. Applying the two phase paradigm, these odds ratios became 0.86, 1.33, and 1.94; the latter reached significance and the beta coefficient was 1.178. CONCLUSIONS: The two phase paradigm allowed us to obtain a more precise estimate of the effect of asbestos on lung cancer. Results are consistent with a doubling of the lung cancer risk with 25 fibreyears asbestos exposure.

Adult↗
PubMed2001

Undescended testis and the risk of testicular cancer: importance of source and classification of exposure information.

BACKGROUND: The strength of the association between undescended testis and testicular cancer varies considerably across studies. Here we report the effect of various classifications of self-reported history of undescended testis and different data sources on the estimates of the risk of testicular cancer from a case-control study. METHODS: We performed a population-based case-control study including 269 testicular cancer cases and 797 controls matched on age and region. Medical history was assessed by interviews (index persons) and mailed questionnaires (mothers). We used conditional logistic regression to calculate odds ratios (OR) and kappa coefficients to assess agreement between different sources of information. RESULTS: Odds ratios for testicular cancer ranged between 2.4 and 5.4 based on the sons' self-reports and between 1.1 and 1.9 based on the mothers' reports. The agreement between the sons and mothers on undescended, gliding or retractile testis was fair (kappa 0.53) and was good when these conditions were treated by surgery (kappa 0.89). The rating of a history of undescended testis by two urologists was fair (kappa 0.54). CONCLUSIONS: The questionnaire design, the classifications of undescended testis and data sources have an important impact on the OR for the association of undescended testis and testicular cancer. These factors may partially explain the heterogeneity of the OR for this association in case-control studies relying on self-reports.

Adolescent↗
PubMed2000

[Risk factors and surgery rates in gallstones. Results of a population-based study].

STUDY OBJECTIVE: The prevalence of gallstone disease, time trends in the frequency of cholecystectomies and risk factors for the occurrence of cholelithiasis were examined in a cross-sectional population study. METHODS: The survey was based on a random sample from the populations of 4 regions in Germany, stratified by region, age and sex. Information on the frequency of gallstone disease and on potential risk factors were collected by standardized interviews. For the statistical analysis, multiple logistic regression was used. RESULTS: Overall, 1,085 persons were interviewed. The age-standardized prevalence of known gallstones was 4.2% for men and 14.5% for women. The frequency of cholecystectomy almost tripled in women from 1985 to 1994 as compared to 1975 to 1984 despite a decreasing trend in gallstone diagnoses in the same time period. No such trend was apparent in men. In men, age, body weight, changes in body weight, diabetes and use of corticosteroids were identified as risk factors for gallstone disease. In women, gallstone disease was also associated with body weight, changes in body weight and age, and, in addition, the number of births. An inverse association with gallstone disease was found for use of oral contraceptives and level of education in women.

Adolescent↗
PubMed2000

Aggregation of lung cancer in families: results from a population-based case-control study in Germany.

The authors investigated familial aggregation of lung cancer by means of a population-based case-control study, conducted in Germany between 1988 and 1993. They compared lung cancer prevalence in first degree relatives of 945 patients and 983 controls, accounting for various potential risk factors using logistic regression and generalized estimating equations. Some 83% of the study participants were male, and about 14% were below age 51 (young age group). Overall, lung cancer in parents or siblings was associated with a 1.67-fold (95% confidence interval (CI): 1.11, 2.52) increase in lung cancer risk. For the young participants, this risk was 4.75 (95% CI: 1.20, 18.77). Having multiple affected relatives (two or more) was related to a threefold risk elevation (odds ratio (OR) = 2.99, 95% CI: 0.32, 27.55). Paternal (OR = 1.64, 95% CI: 0.91, 2.96) but not maternal (OR = 0.91, 95% CI: 0.32, 2.61) lung cancer was associated with an increased risk of the disease. Lung cancer risk from smoking was particularly pronounced in the parents of cases (OR = 12.20, 95% CI: 3.34, 44.62 vs. OR = 7.93, 95% CI: 2.43, 25.91 in parents of controls). No risk elevation was detected for other smoking-related and other cancers in general. Results confirm previous findings and support the etiologic role of a genetic predisposition to lung cancer.

Adult↗
PubMed2000

Occupational lung cancer risk for men in Germany: results from a pooled case-control study.

Occupational exposures such as crystalline silica, diesel engine exhaust, polycyclic aromatic hydrocarbons, and man-made mineral fibers are strongly suspected to increase lung cancer risk. Two case-control studies in Germany conducted between 1988 and 1996 were pooled for a joint analysis. A total of 3,498 male cases and 3,541 male population controls, frequency matched for age and region, were included in the study. The lifelong history of all jobs and industries was coded and occupational exposures were evaluated by expert rating. Odds ratios, crude and adjusted for smoking and asbestos exposure, were calculated by conditional logistic regression. Job-related evaluation showed a statistically significant increased odds ratio adjusted for smoking among farmers; forestry workers, fishermen, and livestock workers; miners and quarrymen; chemical processors; cabinet makers and related wood workers; metal producers and processors; bricklayers and carpenters; road construction workers, pipelayers and well diggers; plasterers, insulators, and upholsterers; painters and lacquerers; stationary engine and heavy equipment operators; transport workers and freight handlers; and service workers. With regard to specific occupational exposures, elevated odds ratios (OR) (95% confidence intervals (CI)) for lung cancer risk adjusted for smoking and asbestos exposure were observed for man-made mineral fibers (OR = 1.48, 95% CI 1.17, 1.88); crystalline silica (OR = 1.41, 95% CI 1.22, 1.62); diesel engine exhaust (OR = 1.43, 95% CI 1.23, 1.67); and polycyclic aromatic hydrocarbons (OR = 1.53, 95% CI 1.14, 2.04). The risk of asbestos exposure, adjusted for smoking was also increased (OR = 1.41, 95% CI 1.24, 1.60).

Case-Control Studies↗
PubMed2000

Lung cancer and exposure to man-made vitreous fibers: results from a pooled case-control study in Germany.

BACKGROUND: To investigate the association between lung cancer and occupational exposure to man-made vitreous fibers (MMVF), a pooled analysis of two case-control studies was conducted in the years 1988-1994. METHODS: The case series consisted of 3498 males who were histologically or cytologically verified primary lung cancer cases. 3541 male population controls were drawn at random from the general population and matched to cases by sex, age, and place of residence. To examine the relationship between MMVF and lung cancer we asked all study subjects who worked for at least 6 months as construction and installation workers whether they ever installed or removed insulations and what kind of insulation material they used. RESULTS: Some 304 (8.7%) cases and 170 (4.8%) controls reported to have insulated with glass wool or mineral wool mats. Coded as ever/never exposed, the odds ratio was 1.48 (95% CI: 1.17-1.88), adjusted for smoking and asbestos. To be sure to exclude any confounding effect of asbestos, we tried to identify those cases and controls who insulated with glass wool or mineral wool mats only and never reported any asbestos exposure. For this group we calculated an odds ratio of 1.56 (95% CI: 0.92-2.65), after adjustment for smoking. An elevated risk was also estimated on the basis of an expert rating which was done for a subgroup of cases and controls. Ever exposure to MMVF (but not to asbestos) in this subgroup yielded an odds ratio of 1.30 (95% CI: 0.82-2.07). CONCLUSIONS: Our study provides some indication for an excess risk of man-made vitreous fibers. This result also persists after adjustment for smoking and asbestos.

Asbestos↗
PubMed2000

Sorting the hype from the facts in testicular cancer: is testicular cancer related to trauma?

PURPOSE: The rate of testicular cancer is increasing. Trauma severe enough to cause testicular atrophy is a putative risk factor for testicular cancer but the epidemiological evidence is not conclusive. A population based, multicenter case-control study was performed from 1995 to 1997 to investigate potential risk factors for gonadal and extragonadal germ cell cancer. MATERIALS AND METHODS: The study was done in 5 German regions. Interviews were performed with 269 eligible male patients with a histologically verified diagnosis and 797 controls. Detailed information on medical and family history was collected at personal interviews. RESULTS: We identified a significantly elevated risk for testicular cancer in relation to testis and/or groin trauma (odds ratio 2.5, 95% confidence interval [CI] 1.51 to 4.20). After introducing a lag time by excluding reports of trauma within the last 12 months before diagnosis or interview the corresponding odds ratio was 2.1 (95% CI 1.24 to 3.61). Analysis of the circumstances and the reported types of injury allowed us to restrict the study to testis trauma specifically, which had an odds ratio of 3.49 (95% CI 1.78 to 6.81). To account for a potential reporting bias analysis was restricted to traumatic episodes for which medical attention was sought. This restriction resulted in an odds ratio of 0.70 (95% CI 0.19 to 2.63) after excluding from study trauma reports within the last 12 months. CONCLUSIONS: The results of our study do not support the hypothesis that testicular trauma is an important risk factor for testicular cancer. The possibility of recall bias should be considered.

Adolescent↗
PubMed1999

Cigar and pipe smoking and lung cancer risk: a multicenter study from Europe.

BACKGROUND: Because limited information is available on the quantitative association between consumption of tobacco products other than cigarettes and lung cancer risk, we undertook a case-control study of this relationship. METHODS: We investigated lung cancer risk among smokers of cigars and/or cigarillos only and of pipes only and compared these risks with the risk of smokers of cigarettes only in a case-control study conducted in seven European areas. Our study population consisted of 5621 male case patients with lung cancer and 7255 male control subjects. Each subject or his proxy was interviewed with respect to the subject's smoking history and other risk factors for lung cancer. RESULTS: The odds ratio (OR) for smoking cigars and cigarillos only was 9.0 (95% confidence interval [CI] = 5.8-14.1), based on 43 exposed case patients and 77 exposed control subjects, and the OR for smoking a pipe only was 7.9 (95% CI = 5.3-11.8), representing 61 case patients and 129 control subjects. The OR for smoking cigarettes only was 14.9 (95% CI = 12.3-18.1), based on 4204 case patients and 3930 control subjects. A dose-response relationship was present for duration of use and cumulative consumption both for cigars and cigarillos and for pipe tobacco. An effect was also suggested for inhalation of cigar and cigarillo smoke. The dose-response relationships between lung cancer risk and either duration of smoking or average and cumulative consumption were similar for cigar and cigarillo smoking, pipe smoking, and cigarette smoking. CONCLUSION: Our results suggest that smoking of European cigars, cigarillos, and pipe tobacco might exert a carcinogenic effect on the lung comparable to that of cigarettes.

Age Factors↗
PubMed1999

Occupational risk factors for lung cancer in women: results of a case-control study in Germany.

BACKGROUND: To investigate the association between lung cancer and occupational factors in women. METHODS: Six hundred eighty-six women with lung cancer and 712 controls matched for age and region were interviewed to gather occupational histories and information about other risk factors and confounders. Odds ratios (OR) and 95%-confidence intervals (CI) were calculated. RESULTS: There were 11 cases and 2 controls who reported occupational asbestos exposure. Significantly elevated risks (P < 0.05, smoking-adjusted), were observed in the following industries: chemical, oil (OR 3.7), pottery, glass (OR 2.5), engine, vehicle building (OR 2.2), paper, wood, print (OR 1.9), cleaning service, hairdressing, housekeeping, waste disposal (OR 1.5); and occupations: assemblers, unskilled metal workers (OR 2.5), stock clerks, etc. (OR 1.6), restaurant owners and hoteliers (OR 2.7), as well as waitresses and travel attendants (OR 2.6). CONCLUSIONS: The study provides evidence that both occupations previously observed as hazardous in males, and occupations of particular significance for women only, play a role in the risk of lung cancer in women.

Adult↗
PubMed1999

[Female life courses and health--results of a study of national survey data of 50-69-year-old women in East and West Germany].

The aim of the study was to examine the impact of different forms of combining family and paid work on the health status of women. The study was a secondary analysis of cross-sectional data from the National Health Survey and included 1530 women, aged 50 to 69 years, from East and West Germany. Three groups were composed to describe different forms of family and occupation in the life course (family or occupational career, combination of family and occupation). Additionally, aspects of the social situation, resources and burdens as well as indicators of health behaviour were included in the analyses. The most remarkable result was a significantly worse state of health of employed and childless women (occupational career), aged 50 to 59 years. This finding remained after adjustment for different potential factors of influence. Considering the increasing proportion of women without children in modern societies, longitudinal analyses would be necessary to investigate the long term effect of familial and occupational factors on the health status of women.

Aged↗
PubMed1998

Occupational risk factors for lung cancer: a case-control study in West Germany.

BACKGROUND: The aim of this study is to evaluate carcinogens and occupations suspected to cause lung cancer and to generate new hypotheses about occupational risks. METHODS: In a hospital-based study 1004 incident lung cancer cases and the same number of population controls matched for region, sex and age were interviewed between 1988 and 1993 for their smoking and occupational history. Exposure assessment was based on 33 job-specific supplementary questionnaires. Conditional logistic regression was used to calculate odds ratios (OR) and to control for smoking and occupational asbestos exposure. RESULTS: Lifelong prevalence of exposure to asbestos was 20.5% for exposure of more than 940 lifetime working hours among controls, corresponding to an OR of 1.62 (95% confidence interval [CI] : 1.28-2.05) that was reduced to 1.45 after adjustment for smoking (P < 5%). Statistically elevated risks after adjustment for smoking and asbestos were seen in metal production and processing workers, transportation workers and freight handlers, in the rubber and plastics industry, in metal production, in engine and vehicle building, and installation. Significantly increased OR after adjustment for smoking and asbestos that deserve further attention were seen in plastics processing workers (OR = 3.49), and sheet and structural metal workers (OR = 2.01 and 2.37, respectively). CONCLUSIONS: The results of the study confirm previously described occupational risks. Because of the possibility of controlling for occupational asbestos exposure, the study gives clear indications for prevention and further research.

Adult↗
PubMed1997

[Occupationally-induced lung cancer--a quantitative evaluation for the North Germany area].

The aim of the study was to estimate the proportion of occupation-related lung cancer for males and females in Northern Germany. 1004 lung cancer cases (839 males, 165 females) were enrolled into an epidemiological case-control study in the study areas Bremen, the surroundings of Bremen and the Frankfurt/Main area. Population controls were matched for sex and region of residence. All patients born after 1913 of German nationality and with a histologically or cytologically verified carcinoma of the lung, the diagnosis not older than 3 months at the date of interview, were eligible. All individuals were personally interviewed with respect to their smoking and job history. Based on a published list of all jobs and branches of industries with sufficient evidence for lung carcinogenity (based on the reviews by IARC), the so called A-List, all individuals were classified regarding their lifelong occupational history. The same procedure was applied with regard to jobs and branches of industries with a suspected risk of lung cancer (List-B). The statistical analysis used conditional logistic regression, controlled for smoking. Being employed in a job of List-A for at least half a year was associated with a statistically significant odds ratio (OR) of 1.63 (p < 0.0001) and resulting attributable risk (AR) of 16% in males. For the B-List an OR of 1.34 and an AR of 10% resulted in males. The estimates of the attributable risk for jobs and branches of industry with a sufficient evidence of lung cancer risk is comparable to the estimates obtained by Doll and Peto for the US. If additionally jobs and branches of industries with a suspected risk for lung cancer is considered, it must be anticipated that approximately one quarter of all newly diagnosed male lung cancer cases in the study region may be caused by occupational risk factors. This should prompt to minimise occupational exposure.

Adult↗
PubMed1995

DNA methylation and the origin of complement factor B polymorphism.

BF is a polymorphic complement component encoded in the MHC. In each of two frequent alleles of BF, BF*FA and BF*FB, the difference in relation to the major allele BF*S has been shown to consist in the nonsynonymous substitution of only one base of the coding sequence. Both substitutions occur within the same codon and affect contiguous positions, corresponding to the dinucleotide CpG in BF*S. We propose here that BF*FA and BF*FB arose independently from BF*S by the frequently described transition mutations associated with cytosine methylation at CpG sites. By probing sperm DNA with methylation-sensitive restriction enzymes, we obtained experimental evidence of germ line methylation of the CpG site considered. The dinucleotide of the BF gene probably constitutes a site for recurrent mutation, and this is of relevance for the use of BF as a genetic marker, and the origin of forms of the protein with altered functional properties.

Base Sequence↗
PubMed1995

Occupational life course and lung cancer risk in men. Findings from a socio-epidemiological analysis of job-changing histories in a case-control study.

Psychosocial factors in general, and the social and psychological conditions of work and occupation in particular, have attracted little attention to the epidemiological investigation into the occupational-related causes of lung cancer. There is some evidence available concerning the impact of loss events--including job losses--on cancer development. During our research presented in this article, we examined job changes and job transitions in the occupational biography of men with regard to their circumstances in terms of (in-)voluntariness both as individual events and the job-changing histories of individuals. We expected the job-changing histories of lung cancer cases to be more involuntary than those of population controls, and vice versa. Our sample contains 391 male case-control pairs. Cases are defined as newly-diagnosed men of German nationality with a histologically- or cytologically-confirmed diagnosis of primary lung cancer. Population controls were drawn randomly from the municipality records of residents and individuals matched to cases 1:1 by age and region. Occupational histories were reconstructed, and information about other classical and suspected risk factors was collected during standardized interviews by trained interviewers. We categorized the reported reasons for job changes, and classified them with respect to voluntariness on a seven-stepped rating scale from -3 'very involuntary' to +3 'very voluntary', defining relations within the empirically established categories. The job-changing histories of individuals are described by using the average score of voluntariness. We measured the degree of voluntariness for the occupational history: (1) by the rounded average score; and (2) by the quintiles of the average score. On the basis of individuals matched odds ratios (OR) estimates are derived for the score of voluntariness unadjusted and adjusted for smoking, asbestos exposure and socio-economic group by conditional logistic regression. The investigation into job-changing histories using the average score of voluntariness lead to similar results for both measuring methods for the total study group. When the rounded score was used, job-changing histories which were assessed as 'very involuntary' and 'involuntary' (score -3 and -2) showed an elevated odds ratio of adjusted 1.41 (95%-CI: 0.57; 3.48), and when they were assessed as 'moderately involuntary' (score -1) the adjusted odds ratio was 1.59 (95%-CI: 1.02; 2.48), as compared with job-changing histories assessed as neutral (score 0). When the degree of voluntariness was measured by quintiles, the first quintile (score -3- < -0.6) showed an elevated risk of adjusted OR 1.36 (95%-CI: 0.79; 2.36) as compared to the third quintile (score -0.2- < -0.1).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

[Not Available].

Explore the source record for details and available documents.

Botany↗