Biomedical subjects

H Becher

Publications and source records attributed to H Becher.

At least 19 recordsLinked to original sources

PubMed1996

The association of leukocyte count, fibrinogen and C-reactive protein with vascular risk factors and ischemic vascular diseases.

In 154 subjects (age 63 +/- 11 years; 63 women and 91 men) randomly selected from the population, we tested the hypothesis that inflammatory parameters are associated with vascular risk factors and particularly with a history of ischemic vascular diseases. The subjects were part of the control group (n = 197) in a case-control study investigating recent infection as a risk factor for acute cerebrovascular ischemia and had been matched for sex and age with patients suffering from acute ischemic stroke or transient ischemic attack. Subjects with malignant or inflammatory diseases, with recent trauma, surgery or vascular diseases (n = 43) were excluded from the present analysis. In multivariate analysis, current smoking, diabetes mellitus, age > or = 65 years, and a history of stroke independently increased the leukocyte count. Hypertriglyceridemia, peripheral arterial disease, and diabetes mellitus were positively associated with C -reactive protein (CRP). Age > or = 65 years and diabetes mellitus independently increased fibrinogen. (p < 0.05, respectively) Subjects with a history of cerebrovascular, cardiovascular or peripheral arterial disease had higher leukocyte counts, fibrinogen and CRP than subjects without vascular risk factors and higher leukocytes and fibrinogen than subjects with one or more risk factors. Subjects under the age of 65 with vascular risk factors but without ischemic diseases had higher leukocyte count, fibrinogen and CRP and subjects older than 65 with risk factors had higher CRP than subjects without risk factors or ischemic diseases in the same age group. (p < 0.05, respectively) These results support the hypotheses that low-grade inflammation is associated with vascular risk factors and that inflammatory mechanisms may contribute to the risk of organ ischemia.

Adolescent↗

PubMed1996

Estimating disease risks for individuals with a given family history in different populations with an application to breast cancer.

For many chronic diseases, including most of the common cancers, a family history is known to be a strong independent risk factor. For breast cancer, estimation of risk as a function of family history is considered to provide useful risk assessment for women with a family history of breast cancer. Detailed tables that predict the cumulative risk of breast cancer at specific ages based on various combinations of family history have been constructed for the American white population. Most chronic diseases, however, have a multiple etiology, with multiple genetic and environmental factors. Family history can thus be a result of different susceptibility loci and the aggregation of sporadic cases by chance. Since the relative contribution of the genetic factor may differ in different populations, these tables may not be directly applicable to other populations. We present a method to decompose available estimates of risk based on family history for an arbitrary disease into probabilities for genotype frequency given a particular family history and for disease probabilities by genotype carrier status. These can be reconstructed to obtain risk estimates for different populations. Implicit assumptions are made in the estimation process. These are based on the current state of knowledge and can be updated as further knowledge accumulates.

Adult↗

PubMed1996

Cancer mortality in German male workers exposed to phenoxy herbicides and dioxins.

In an occupational cohort study, the relation between exposure to phenoxy herbicides, and contaminants (dioxins and furans) and cancer mortality was investigated. A total of 2,479 workers from four plants in Germany were included, with a mortality follow-up until the end of 1989 (for one cohort, until the end of 1992). A total of 484 deaths were recorded yielding a standardized mortality ratio (SMR) of 101 (95 percent confidence interval [CI] = 92-111) for total mortality, and an SMR of 119 (CI = 100-141) for all malignant diseases. A variety of herbicides was produced, including those which are known to have been contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). High dioxin and furan exposure (in particular, exposure to TCDD, but also to higher chlorinated dioxins) had occurred in two of the four plants as shown by blood-fat measurements in a sample of workers. Mortality from all neoplasms increased with latency and was highest in the largest plant where the highest TCDD blood levels were recorded. An increased mortality in the total cohort from respiratory cancer (SMR = 154, CI = 115-202), cancer of the buccal cavity and pharynx (SMR = 295, CI = 135-560), and non-Hodgkin's lymphoma (SMR = 326, CI = 119-710) was observed. Our findings are consistent with results from other cohorts which showed an increased overall cancer mortality and mortality of respiratory cancer after long-term exposure to these phenoxy herbicides and dioxins.

Adipose Tissue↗

PubMed1996

Elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in occupationally exposed persons.

The elimination of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) was investigated in a group of n = 43 exposed workers with 2 blood measurements and n = 5 workers with 3 measurements. Under the assumption of a one-compartment, first-order kinetic model the median half-life for 2,3,7,8-TCDD was 7.2 yr, while for the other dioxins the estimates were between 3.7 yr for 1,2,3,4,6,7,8-HpCDD (hepta-chlorinated) and 15.7 yr for 1,2,3,7,8-PCDD (penta-chlorinated). For the furans median half-lives between 3.0 yr for 1,2,3,4,6,7,8-HpCDF and 19.6 yr for 2,3,4,7,8-PCDF were observed. There was no indication for a deviation from a first-order kinetic. Increasing age and percent body fat were associated with increasing half-life for most of the congeners. Smokers in general had a faster decay than non- and ex-smokers. In summary, the higher chlorinated PCDD/F like TCDD appear to be highly persistent in humans with half-lives ranging between 4 and 12 yr.

Adipose Tissue↗

PubMed1995

Clinical evaluation of left heart Doppler contrast enhancement by a saccharide-based transpulmonary contrast agent. The Levovist Cardiac Working Group.

OBJECTIVES: A multicenter study was carried out to evaluate the efficacy with which SHU 508A enhances left heart Doppler signals and improves the clinical quantification of valve disease. BACKGROUND: Poor signal-to-noise ratio often limits the Doppler interrogation of left heart flows. This problem may be resolved by the enhancement of Doppler signals by an ultrasound contrast agent capable of pulmonary transmission, such as the recently developed SHU 508A. METHODS: Left heart contrast enhancement was tested for 1) continuous wave Doppler evaluation in 51 patients with aortic stenosis, 2) pulsed Doppler transthoracic evaluation of pulmonary venous flow in 85 patients, and 3) color Doppler evaluation of mitral regurgitation in 60 patients. Studies were performed immediately before and during the intravenous administration of SHU 508A (16 ml of 200 mg/ml) and compared with unenhanced transesophageal data in representative subsets of patients. RESULTS: SHU 508A had no serious adverse effects. A significant increase in left heart Doppler signal intensity lasted for 30 to 300 s. The continuous wave Doppler velocity envelope was enhanced for all jets, but Doppler peak velocity was not altered in high quality baseline studies. However, Doppler contrast enhancement resulted in higher measured peak gradients (p < 0.001) in 29 patients with aortic stenosis who had poor quality baseline studies. This improved the overall correlation with invasive pressure measurements (r = 0.73 vs. r = 0.89, p < 0.01). The enhanced pulsed Doppler traces of transthoracic pulmonary venous flow allowed quantitative analysis in 92% patients (vs. 27% at baseline) and correlated well with peak velocities and velocity profiles obtained by transesophageal echocardiography (r = 0.91, p < 0.001). The enhanced color Doppler display of regurgitant jets increased jet area with a high interindividual variability (mean 276%), resulting in almost identical jet areas as unenhanced transesophageal values (r = 0.97, p < 0.001). CONCLUSIONS: SHU 508A is a safe transpulmonary contrast agent that significantly enhances both spectral and color Doppler signals in the left heart. In specific patient subsets, the increase in signal-to-noise ratio improved the quantitative assessment of aortic stenosis, pulmonary venous flow and mitral regurgitation.

Aortic Valve Stenosis↗

PubMed1995

Lung cancer deaths attributable to indoor radon exposure in West Germany.

BACKGROUND: There is substantial epidemiological and experimental evidence that exposure to radon at levels found in underground mines can cause lung cancer. Although radon levels measured in homes are normally substantially lower, there is concern about the presence of a known lung carcinogen in a residential setting. METHODS: Using national survey data on radon concentrations in homes in the former West Germany, the proportion and absolute numbers of lung cancer deaths attributable to radon are estimated. As lung cancer risk models derived directly from residential radon studies are not yet available, the risk model developed recently by Lubin et al. from a joint analysis of 11 underground miners' studies is applied. For an estimate of the impact of smoking on radon-attributable lung cancers, three different approaches are used and compared. RESULTS: Our analysis shows that after adjusting for dosimetry differences between mines and homes about 7% of all lung cancer deaths in the western part of Germany may be due to residential radon. This corresponds to a total of about 2000 deaths (95% CI: 500-8200), 400 in females and 1600 in males. Adjusting for the intermediate relationship for smoking and radon, the attributable risk is estimated to be about 4-7% for smokers and 14-22% in non-smokers. CONCLUSIONS: Our analysis basically confirms the results of former calculations with regard to the total number of lung cancer deaths attributable to radon in West Germany. However, we show that the standard practice that applies the same model to smokers and non-smokers may result in biased estimates for these groups.

Air Pollution, Indoor↗

PubMed1995

Recent infection as a risk factor for cerebrovascular ischemia.

BACKGROUND AND PURPOSE: Previous infection is discussed as a risk factor for ischemic stroke in children and younger adults. We tested the hypothesis that the role of recent infection in cerebrovascular ischemia is not restricted to younger patients and investigated which infections are mainly relevant in this respect. METHODS: We performed a case-control study with 197 patients aged 18 to 80 years with acute cerebrovascular ischemia and 197 randomly selected control subjects matched for sex, age, and area of residence. RESULTS: Infection within 1 week before ictus or examination was significantly more common among patients (38 of 197) than control subjects (10 of 197; odds ratio [OR], 4.5; 95% confidence interval [CI], 2.1 to 9.7). Patients more often had febrile and subfebrile infections (> or = 37.5 degrees C) than control subjects (29 of 197 versus 5 of 197; OR, 7.0; 95% CI, 2.5 to 20). Respiratory tract infections were most common in both groups. Bacterial infections dominated among patients but not among control subjects. Infection increased the risk for cerebrovascular ischemia in all age groups; this reached significance for patients aged 51 to 60 and 61 to 70 years. The profile of vascular risk factors was similar in patients with and patients without previous infection. Infection remained a significant risk factor when previous stroke, hypertension, diabetes mellitus, coronary heart disease, and current smoking were included as covariates in a logistic model (OR, 4.6; 95% CI, 1.9 to 11.3). CONCLUSIONS: Recent infection, primarily of bacterial origin, may be a risk factor for cerebrovascular ischemia in older as well as younger patients.

Adolescent↗

PubMed1995

Soft tissue sarcoma and non-Hodgkin's lymphoma in workers exposed to phenoxy herbicides, chlorophenols, and dioxins: two nested case-control studies.

We examined the effect of exposure to chemicals present in the production and spraying of phenoxy herbicides or chlorophenols in two nested case-control studies of soft tissue sarcoma and non-Hodgkin's lymphoma. Eleven sarcoma and 32 lymphoma cases occurring within an international cohort were matched for age, sex, and country of residence with 55 and 158 controls, respectively. Exposures to 21 chemicals or mixtures were estimated by three industrial hygienists who were blind to the subject's case-control status. Excess risk of soft tissue sarcoma was associated with exposure to any phenoxy herbicide [odds ratio (OR) = 10.3; 95% confidence interval (CI) = 1.2-91] and to each of the three major classes of phenoxy herbicides (2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and 4-chloro-2-methylphenoxyacetic acid), to any polychlorinated dibenzodioxin or furan (OR = 5.6; 95% CI = 1.1-28), and to 2,3,7,8-tetrachlorodibenzo-p-dioxin (OR = 5.2; 95% CI = 0.85-32). Sarcoma risk was not associated with exposure to raw materials or other process chemicals. In the non-Hodgkin's lymphoma study, associations were generally weaker than those found in the study on sarcoma. These findings indicate that workers exposed to phenoxy herbicides and their contaminants are at a higher risk of soft tissue sarcoma.

Case-Control Studies↗

PubMed1995

[Risk assessment for familial occurrence of breast cancer].

There is now unequivocal evidence that an estimated 5% of breast cancer cases is inherited in families. Inherited predisposition of cancer in these families is thought to be the result of a mutation in one of several highly penetrant autosomal dominant genes such as BRCA1 or BRCA2. The BRCA1 gene which is localized on chromosome 17 q was recently isolated and at about the same time BRCA2 was localized to chromosome 13 q. A number of other genetic mutations is also associated with predisposition to breast cancer but accounts for a very small proportion of inherited breast cancer. Many women want to know whether they have inherited a gene predisposing to breast cancer. Those with a family history of breast cancer are particularly concerned about their risk of disease. Currently the assessment of an individual's risk of breast cancer can be undertaken using prediction models based on family history and can be further refined when molecular genetic investigations became available. Without molecular characterisation the Claus tables derived from the Cancer and Steroid Hormone Study data set are best suited to predict breast cancer risk based on age of onset of affected relatives. Direct screening for mutations in breast cancer genes in not yet generally available. Testing for inherited susceptibility is currently being offered to selected families where multiple cases of breast and/or ovarian cancer are diagnosed at an early age (younger than 45 years) as part of research protocols. In these families the so-called indirect gene analysis for linkage of disease to BRCA1 and BRCA2 or the direct analysis of mutations with functional significance in the BRCA1 gene allows relatively refined risk assessment for non-diseased female family members. Some examples will be presented to illustrate risk assessment in different familial and individual situations. Risk assessment including test result interpretation and counselling can be appropriately provided directly to the patient by physicians and genetic counsellors in a coordinated genetic counselling setting.

Adult↗

PubMed1995

[Occupational exposure and histologic differentiation of lung cancer. Retrospective assessment in Cracow].

A population-based case-control study was performed in Cracow, Poland. Male cases and controls were identified from the Cracow Death Register. Information were obtained by mailed questionnaire from next-of-kin on smoking, occupational branch, occupational exposures and other pertinent variables. Response rates were 73.5% in cases and 72.0% in controls. For cases that underwent a bronchial biopsy or surgical excision the histological diagnosis of the tumor was obtained from clinical records. The case group contained 343 subjects with squamous cell carcinomas, 151 small cell carcinomas and 106 adenocarcinomas. 27 cases showed other histological types (large cell carcinoma and not classifiable). Analysis was performed separately by histological type for occupational exposure variables adjusted for smoking. Long-term exposure to mineral dust and metal dust (20 years or more) was found to be a significant risk factor for small cell and squamous cell carcinoma. The effect was more pronounced if the analysis was restricted to the age groups "less than 70 years". The highest relative risk due to occupational exposures was found for squamous cell carcinoma and mineral dust exposure for more than 20 years (RR = 2.45, 95% CI 1.43-4.19). The estimated effect of mineral dust on small cell carcinoma and adenocarcinoma was slightly lower (RR = 2.29, 95% CI 1.16-4.53 and RR = 2.04, 95% CI 0.89-4.64, respectively). The effect of metal dust and fumes appeared to be about the same for squamous and small cell carcinoma.

Adenocarcinoma↗

PubMed1995

[Epidemiological risk assessment for chemical substances].

Epidemiological risk assessment for chemicals is usually based on analytical studies like case-control or cohort studies. Both study types have a number of specific advantages and disadvantages which are outlined. The evaluation of a substance is done on the basis of the results of these studies either qualitatively or quantitatively. For quantitative risk assessment reliable data are needed for the dose of the substance to which the individuals in the study were exposed. For a number of chemical sufficient data are available. Among these are experimental pollutants like arsenic, benzene or radon. As an example the possibilities of risk assessment for dioxin are outlined. The knowledge on the carcinogenicity of dioxin has significantly improved during the last years. Some research groups currently use data of a number of cohort studies to perform a quantitative risk assessment.

Carcinogens↗

PubMed1995

Do the nonsmoking daughters of smokers tend to marry smokers? Implications for epidemiological research on environmental tobacco smoke: the IARC collaborative study.

The IARC collaborative study on exposure to environmental tobacco smoke (ETS) involved collecting interview data and biochemical indicators of exposure from 1369 nonsmoking women in 13 centers in 10 countries. Information on childhood and adulthood exposure to other people's smoke and duration of this exposure from both parents and spouse was gathered at the interview. Of the 900 women whose husbands smoked (current or exsmokers), 71.3% had one or both parents who smoked (predominantly the father), whereas among the 277 women married to never-smokers, only 60.3% had at least one parent who smoked. The odds ratio for the daughter of a smoker to marry a smoker was, therefore, 1.64 (95% confidence interval = 1.24-2.17; P > 0.001), and there was an exposure-response relation between the number of years of childhood exposure to ETS from the parents and the likelihood of being married to a smoker. These results show that nonsmoking women married to smokers are more likely to have been exposed to tobacco pollution during their whole life. Because the duration of exposure is known to be important in the genesis of lung cancer, some of the excess risk of lung cancer in nonsmoking women married to smokers may be due exposure to ETS from parents during childhood.

Adolescent↗

PubMed1994

Evidence for cardiovascular remodeling in a patient with Bartter's syndrome.

In a 56-year-old normotensive white male subject with a 12-year history of hypokalemic alkalosis, hyperreninemia, and aldosteronism, the diagnosis of Bartter's syndrome was established on the basis of an impaired maximal renal diluting capacity and decreased distal fractional chloride absorption [CH2O/(CH2O+CCl)]. Negative urine analysis for diuretics suggested that this renal tubular defect was not secondary to diuretic (ab)use. In this normotensive patient with hyperreninemia and secondary aldosteronism, significant cardiovascular remodeling could be observed. Thus, in spite of normal arterial blood pressure and normal left ventricular systolic function (ejection fraction > 70%), impaired left ventricular diastolic function was observed using pulsed-wave Doppler echocardiography. Moreover, duplex analysis of the common carotid artery revealed significant intima-media hypertrophy with an average intima-media diameter of 0.9 mm (normal < or = 0.6 mm). Also, forearm venous occlusion plethysmography revealed an abnormally high minimal forearm vascular resistance following a 10-min period of forearm ischemia handgrip exercise suggesting remodeling within the peripheral arterioles. Thus, in a patient with Bartter's syndrome and activated neurohormonal systems such as the renin-angiotensin system, cardiac and vascular remodeling can be observed in the absence of hypertension. In analogy to the results of experimental studies showing that angiotensin II and noradrenaline act as growth factors on cardiac and vascular cells, cardiovascular remodeling present in our patient with Bartter's syndrome may be explained by increased activity of angiotensin II and/or noradrenaline.

Arteries↗

PubMed1994

Nitrate in drinking water. A case-control study on primary brain tumours with an embedded drinking water survey in Germany.

BACKGROUND: Nitrate is known to be a precursor in the endogenous formation of N-nitroso compounds which are thought to be associated with the development of brain tumours. METHODS: We conducted a population-based case-control study on the aetiology of primary brain tumours in adults in which the nitrate concentration in drinking water was investigated as a quantitative variable. For this purpose, an additional drinking water survey was performed. RESULTS: Analysis of 173 incident cases and 418 controls did not show any relationship between exposure to nitrate in drinking water and risk of developing primary brain tumours. We found mean nitrate concentrations of 15.98 mg/l (SD 15.61) in the drinking water history of the cases and of 16.16 mg/l (SD 15.72) for controls. In addition, we compared the quantitative history of nitrate contamination of the study participants to a semi-quantitative assessment by a stick method. Although we found good agreement between these methods we would recommend the use of detailed water surveys for retrospective studies on contaminants in drinking water. CONCLUSION: The results suggest the absence of an association between nitrate levels in drinking water and the risk of brain tumours. However in order to draw definite conclusions quantitative prospective studies are needed.

Adult↗

PubMed1994

Doppler enhancement with SH U 508A in multiple vascular regions.

PURPOSE: To determine the magnitude and duration of peripheral vascular and cardiac Doppler signal enhancement after intravenous administration of contrast agent SH U 508A. MATERIALS AND METHODS: Suboptimal cardiac or peripheral vascular Doppler examinations were evaluated. A total of 75 intravenous bolus injections were made in 30 patients. Spectral audio Doppler intensity was measured throughout the duration of contrast effect. RESULTS: No clinically relevant adverse effects were noted, and Doppler enhancement was apparent in all cases. The diagnostic confidence of the investigators when scored before and after Doppler enhancement improved from 35% to 91% (P < .05). Doppler intensity increased more than 16 dB in all vascular regions investigated (P < .05). The contrast effect lasted for more than 120 seconds in the peripheral vascular and cardiac groups at equivalent doses. CONCLUSION: Intravenously administered SH U 508A is effective in markedly increasing cardiac, femoral arterial, and transcranial (cerebral arterial) Doppler signal intensity. The effect improves the clinical diagnostic confidence in cases of suboptimal unenhanced Doppler examinations.

Cerebral Arterial Diseases↗

PubMed1994

[The importance of genetic factors for development of breast cancer].

It is well documented that breast cancer aggregates in certain families suggesting a genetic etiology for this cancer. Numerous epidemiologic studies have shown that women with a first degree relative (mother, sister) with breast cancer have double the risk of developing this cancer when compared to women in the general population. More recent studies have shown that the magnitude of the risk of developing breast cancer is dependent on the age at diagnosis and the number of relatives affected. Aggregation of breast cancer in families in itself does not clarify the true nature of the underlying factors which could be genetic or due to familial resemblance in other risk factors. Complex segregation analyses of breast cancer families suggest that breast cancer susceptibility is inherited in some families as an autosomal dominant trait. Recently, a breast cancer susceptibility gene, BRCA1, has been mapped to chromosome 17q12-q21 through linkage analyses. BRCA1 appears to play a role in families with a large number of breast cancer cases who have developed breast cancer before the age 45, and/or who have breast and ovarian cancer cases. The risk of cancer for female carriers of the BRCA1 mutation has been estimated to be 87% for breast cancer and 44% for ovarian cancer by the age of 70. BRCA1 seems to play a role in only a proportion of affected families and it is likely that other genes are also involved. In the majority of breast cancer families with two or three cases, BRCA1 appears to play a small role.

Adult↗

PubMed1994

Efficacy SH U 508 A (Levovist) as blood pool enhancer in the Doppler evaluation of multiple vascular regions.

SH U 508 A (Levovist) as a blood pool enhancer to investigate multiple vascular regions with Doppler ultrasonography. Thirty patients with sub-optimal cardiac or peripheral vascular Doppler exams received 75 intravenous contrast bolus injections in all to investigate the intensity and the duration of Doppler signal enhancement after the i.v. administration of an echo contrast agent - i.e., SH U 508 A (Levovist) by Schering AG, Berlin, Germany. All cases exhibited Doppler enhancement and the investigator's "diagnostic confidence" increased from 35% (precontrast) to 91% (post-contrast) (p < 0.05). Audio Doppler intensity was measured quantitatively and more than 16 dB enhancement was demonstrated in all the vascular regions under investigation (p < 0.05). Enhancement lasted more than 60 seconds in the peripheral vessels and 120 seconds in the heart vessels. No clinically relevant adverse reactions were ever observed. To conclude, i.v., -administered SH U 508 A (Levovist) is a valuable means of increasing cardiac, femoral arterial and transcranial (cerebral arterial) Doppler signal intensity. Enhancement is durable and improves the clinical diagnostic confidence in the patients with suboptimal Doppler findings.

Adult↗

PubMed1993

Chemical exposure in manufacture of phenoxy herbicides and chlorophenols and in spraying of phenoxy herbicides.

Exposure patterns are reported for manufacturing and sprayer cohorts incorporated in the "IARC International Register of Workers exposed to Phenoxy Herbicides and Contaminants." Information was based on company questionnaires, company reports, plant visits, and serum 2, 3, 7, 8-TCDD measurements. In addition to phenoxy herbicides and chlorophenols, workers in manufacturing plants may have been exposed to raw materials, process chemicals, other agents synthesized or formulated, and impurities of all these agents. Sprayers also had a complex exposure pattern, including phenoxy herbicides and some other pesticides, their carriers and additives, and residues of chemicals formed during manufacture. Occurrence of agents, including dioxins, varied between countries. Biological monitoring and industrial hygiene data were rarely available, most since the late 1970s. Exposure of workers depended mainly on the jobs they performed, but several factors influenced level of exposure. A quantitative exposure classification is not feasible in this study. Semiquantitative exposure estimates may be derived through a critical interpretation of biological monitoring and industrial hygiene data together with individual work histories.

2-Methyl-4-chlorophenoxyacetic Acid↗