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N Becker

Publications and source records attributed to N Becker.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Concept and implementation of model projects for mammography screening in Germany].

The carriers of the German Statutory Health Care System have recognized that only mammographic screening according to the European Guidelines for the Quality Assurance of Mammography Screening will permit early detection of breast cancer with an acceptable risk/benefit ratio. In the German pilot projects, regional mammography screening programmes according to the European guidelines are being tested in the framework of the German health care system. The European guidelines require comprehensive quality assurance of all relevant steps in the chain of events involved in screening, from invitation on to therapy and follow-up. Such comprehensive quality assurance involves several medical specialities and other professional groups dealing with out-patient and in-patient health care and requires long-term cooperation with public institutions (population registries, cancer registries). The objective of the pilot projects is to test the organizational and legal conditions essential to introduction of a mammographic screening programme according to the European quality assurance guidelines in Germany.

Breast Neoplasms↗
PubMed2001

[Development of the incidence and mortality of breast cancer].

In Germany, breast cancer is still the most frequent cancer site with approximately 45.000 incident cases and 18.000 deaths annually. After a continuous increase of mortality for decades and a short period of stagnation, a decline can be observed since a couple of years. However, this turnaround has not been preceded by an analogous evolution of breast cancer incidence. A similar development can also be observed in other countries. The conditions under which this changing trend has occurred indicate that it might have been caused mainly by better treatment and only to a low extent by altered prevalence of risk factors or the implementation of screening programmes. Due to the expected latency, an influence of organized screening on mortality can be expected only at the end of the 1990s, i.e., at the end of the period for which data is available or later. In the discussion about implementation of quality-controlled screening in Germany, it should be kept in mind that the quality of the entire programme--starting with screening and ending with therapy--will decide to what extent breast cancer mortality can be reduced.

Breast Neoplasms↗
PubMed2001

Asbestos exposure and malignant lymphomas--a review of the epidemiological literature.

There has been a significant number of case reports on the occurrence of lymphomas in people previously exposed to asbestos. This raises the question of whether corresponding results are available from analytical epidemiological studies. In the present review of the epidemiological literature, we describe the results of the six cohort and 16 case-control studies that - according to our research - were published up to 1999 and, directly or indirectly. shed light on the above question. In summarizing the results of these studies, we have distinguished between non-Hodgkin lymphoma (NHL), chronic lymphatic leukemia (CLL) and plasmocytoma/ multiple myeloma (MM). A causal relationship between asbestos exposure and the subsequent development of lymphomas cannot be derived from the available results. However, since quite a number of studies and the combined analysis indicate a (weakly) increased risk, this question should be considered directly in future epidemiological studies. Such studies should address separately the various sub-entities, employing the latest internationally agreed classification, and should also use the latest methods of quantifying exposure.

Asbestos↗
PubMed2001

Epidemiologic aspects of cancer prevention in Germany.

In Germany, as in other highly industrialized countries, cancer is the second most common cause of death. With approximately 210,000 individuals dying each year from malignant tumours, roughly one in four deaths in Germany can currently be attributed to cancer. Only in the past few years has there been a slow decline in the age-standardized mortality rates for cancer, even among men. This follows a long period of some decades, during which the mortality steadily increased and then persisted at a high level. The reversal, however, does not mean that the situation is no longer a cause for concern. In fact, for the most common cause of death, namely the cardiovascular diseases, a much greater decrease in mortality has been observed for many years now. If this trend continues, cancer could become the largest killer in another 15 to 20 years. On the other hand, we have been aware since the end of the 1960s that the majority of cancers are caused by environmental influences and are thus, in principle, avoidable. In the present contribution we present: (a) the fundamental arguments to support the thesis that a large proportion of cancers, and of cancer deaths, could be avoided; and (b) an estimate for Germany of both the theoretical potential of primary cancer prevention and also the practically attainable potential. The estimates are based on very conservative assumptions. They yield, for the theoretical potential, values in the range 43-65% and for the reduction actually obtainable in the medium term due to primary prevention, values of 18-31%.

Alcohol Drinking↗
PubMed2001

Cancer mortality in the United States and Germany.

PURPOSE: The USA and Germany are currently two of the world's leading industrial nations with comparable standards of living and considerable similarities in lifestyle. Fifty years ago, i.e., in the years following the Second World War, the living conditions in the two countries were completely different. If it is true that the major part of cancer occurrence is lifestyle-related, we should see corresponding discrepancies and assimilations on the level of cancer occurrence. METHODS: As an exercise in descriptive epidemiology, we compare the time trends in German and US cancer mortality in order to examine whether they parallel indeed the differences and changes in lifestyle factors of the two countries. RESULTS: Overall, we found the cancer mortality of the two countries converging to rather similar rates. However, in detail, the data indicate various inconsistencies between the patterns of lifestyle factors and cancer mortality in the two countries: similar lung cancer rates, despite rather different patterns of cigarette consumption, or decreasing rectal cancer mortality, despite increasing prevalence of risk factors, are examples. CONCLUSIONS: Promising changes with regard to relevant risk factors indicate that the recent decline of cancer mortality in both countries will continue. Nevertheless, vigorous action towards primary prevention in Germany and more effective screening programs in both countries appear recommendable.

Adult↗
PubMed2001

Cross-sectional study on cytokine polymorphisms, cytokine production after T-cell stimulation and clinical parameters in a random sample of a German population.

We investigated, in a random sample of a German population, the association of polymorphisms in the genes encoding the cytokines interleukin 2 (IL-2), interleukin 4 receptor (IL-4R), interleukin 6 (IL-6), interleukin 10, interferon gamma (IFNG), tumor necrosis factor (TNF) and intercellular adhesion molecule 1 (ICAM-1) with (1) secreted levels of the respective proteins after T-cell stimulation and (2) data on selected diseases obtained from a questionnaire. The scope of this investigation was to further the understanding of the genetic background of allergies and common colds and the observed heterogeneity of many immune responses in the human population. In contrast to previous reports that showed associations of promoter polymorphisms of cytokine genes with the production of the corresponding protein, we did not find associations with protein release after T-cell stimulation in vitro. Among the correlations with the clinical parameters, we observed an increased risk of allergies (odds ratio, OR= 4.1; confidence interval, CI: 1.6-10.4), particularly hay fever (OR=5.6, CI: 1.8-17.1) in individuals homozygous for IFNG 13 CA-repeats. In combination with the TNF wildtype, the risk for hay fever increased to OR=8.4 (CI: 2.7-25.6). Furthermore, individuals with a combination of IL2, IL6 and ICAM-1 polymorphisms tended to have higher frequencies of reported common colds than individuals with the alternate genotypes. As these are results of an explorative investigation, these findings require confirmation in material from a different source. If confirmed, these relationships could contribute to a better characterisation of the genetic component of allergies.

Aged↗
PubMed2001

Exposure to armament wastes and leukemia: a case-control study within a cluster of AML and CML in Germany.

An unusually high incidence of acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) concentrated in a specific locality of a region in Germany motivated a descriptive incidence study in that region which showed a near 10-fold increased risk of CML among males but not among females (Kolb G, Becker N, Scheller S, Zugmaier G, Pralle H, Wahrendorf J, Havemann K. Increased risk of acute myelogenous leukemia (AML) and chronic myelogenous leukemia (CML) in a County of Hesse, Germany, Soc Prev Med 1993;38:190-195). Since a serious environmental contamination of areas in this locality with armament wastes containing toluene-derivatives has been known for a long time, the hypothesis arose that TNT production and the related severe contamination of soil and water might be responsible for the observed higher risk. We carried out a case-control study within the cluster to test this hypothesis. Overall, the results do not confirm the hypothesis. There is an indication of a relationship of an increased odds ratio with the exposure for a small group of persons who lived at a particular site in one of the two communities involved during the peak phase of TNT production during the 1940s. However, this finding is spurious and cannot explain the large majority of cases which occurred in that area in the 1980s. At the moment, no other explanation can be given for the increased risk of leukemias in that area.

Adult↗
PubMed2001

Statistical issues of quality control in organised breast cancer screening.

BACKGROUND: European guidelines for breast-cancer screening recommend an integrated approach of mammography screening with subsequent assessment and biopsy, if required, in one screening unit under permanent quality control, for which target values are released. Although the calculation of the respective rates (e.g. for participation, assessment, biopsy, or cancer detection) appears trivial, the statistical assessment of their compatibility with the target values is less obvious. This is especially true if subjects with a positive diagnostic result leave the screening-assessment chain prematurely, and information about further diagnostic results outside the organised screening is lacking. METHOD: Statistical models for the basic situation, in which complete information about the screening and assessment outcome is available, as well as for when information is incomplete, are presented. The statistical methods for obtaining the confidence limits, statistical tests and sample sizes needed to obtain a desired power of tests for the process parameters of interest are also given. RESULTS: The sample-size calculations indicate that large numbers of enrolled subjects are required to obtain reasonably narrow confidence limits, and that incomplete information about the outcome of diagnostic procedures among screening positives considerably worsens the feasibility of quality control. CONCLUSIONS: Although the methodology is specified for breast-cancer screening, it should be adaptable easily to other screening issues.

Breast Neoplasms↗
PubMed2001

Nuclear corepressor and silencing mediator of retinoic and thyroid hormone receptors corepressor expression is incompatible with T(3)-dependent TRH regulation.

Ligand-independent repression by thyroid hormone (T(3)) receptors on positive T(3)-responsive genes requires corepressor proteins. However, the role of corepressors in regulating genes such as hypothalamic TRH, which are under negative control by T(3), is largely unknown. We examined the expression of mRNAs encoding the corepressors NCoR (nuclear corepressor) and SMRT (silencing mediator of retinoic and thyroid hormone receptors) in the TRH-producing paraventricular nucleus of the mouse hypothalamus. Further, we carried out in vivo functional studies by overexpression of both corepressors. Three lines of evidence show that NCoR and SMRT expression is incompatible with physiological regulation of TRH. First, Northern blotting revealed TRH and NCoR mRNA expressions to be inversely correlated during postnatal development and as a function of thyroid status. Second, in situ hybridization showed that NCoR and SMRT mRNA expression profiles in the paraventricular nucleus were distinct from that of TRH mRNA. Third, over-expression of full length NCoR and SMRT in the hypothalamus abolished T(3)-dependent repression of TRH-luciferase. However, over-expression of NCoR or SMRT did not affect either T(3)-independent activation of TRH-luciferase transcription, or transcription from a positively regulated T(3)-response element. We conclude that T(3) -dependent feedback on TRH expression is unlikely to involve the corepressors NCoR or SMRT.

Aging↗
PubMed2001

Influence of dietary fatty acid, vegetable, and vitamin intake on etheno-DNA adducts in white blood cells of healthy female volunteers: a pilot study.

Etheno-DNA adducts such as 1,N(6)-ethenodeoxyadenosine (epsilondA) and N(2),3-ethenodeoxycytidine (epsilondC) are formed as result of oxidative stress and lipid peroxidation via reactive alkenals (J. Nair et al., Mutat. Res., 424:59-69, 1999). High pi-6 polyunsaturated fatty acid intake markedly increased levels of WBCs in female volunteers on a controlled diet (J. Nair et al., Cancer Epidemiol. Biomark. Prev., 6:591-601, 1997). In healthy female volunteers we investigated possible correlations between dietary fatty acid intake (by questionnaire), concentration of linoleic acid (LA) and oleic acid (OA) in serum (n = 34), and etheno-DNA adduct levels in WBC (n = 42). Two groups of samples were selected according to dietary intake >15 g (group A) or <5 g (group B) LA/day. Serum samples were analyzed for free OA and LA by gas chromatography-mass spectroscopy and WBC-DNA for epsilondA and epsilondC adducts by immunoaffinity (32)P postlabeling. On a group level, serum LA and OA concentrations were higher in group A than group B, whereas the LA/OA ratios were similar. The mean epsilondA and epsilondC levels did not significantly differ in groups A and B, but a third of the individuals had more than twice the mean adduct levels than the rest. Correlation analyses revealed a significant inverse correlation for epsilondA in WBC-DNA and vegetable or vitamin E consumption. We conclude that etheno-DNA adduct levels are not determined by LA intake alone but might depend on the ratio of pi-6 polyunsaturated fatty acid:other fatty acids and of antioxidants consumed in the diet. This pilot study also indicated a protective effect of dietary vitamin E and vegetables against miscoding, lipid peroxidation-induced DNA lesions.

Adult↗
PubMed2000

Treatment outcome of chronic non-malignant pain patients managed in a danish multidisciplinary pain centre compared to general practice: a randomised controlled trial.

This randomised controlled study investigated the effect of outpatient multidisciplinary pain centre treatment (MPT) compared with treatment by a general practitioner after initial supervision by a pain specialist (GP-group) and with a group of patients waiting for 6 months before treatment was initiated (WL-group). One-hundred-and-eighty-nine chronic non-malignant pain patients were studied. At referral, and after 3 and 6 months patients filled in questionnaires evaluating pain intensity, health related quality of life (HRQL) and use of analgesics. HRQL was evaluated using the Medical Outcome Study-Short Form (SF-36), the Hospital Anxiety and Depression scale (HAD) and the Psychological General Well-being Scale (PGWB). After 6 months patients allocated to MPT (n=63) reported statistically significant reduction in pain intensity (VAS-score, P<0.001), improvement in psychological well-being (PGWB, P<0.001), quality of sleep (P<0.05) and physical functioning (SF-36-Phycical Functioning, P<0.05). No improvements were seen in the GP-group (n=63). In the WL-group (n=63) a statistically significant deterioration was observed in PGWB-scores, HAD-scores and in 6 of 8 SF-36-subscores (P </= 0.05). A reduction in use of opioids administered on demand was obtained in the group receiving MPT (P<0.001). In the MPT- and GP-groups a decrease in the use of short acting opioids was observed (P<0.01). No change in use of analgesics was seen in the WL-group. The study showed that (i) in the MPT-group there was a significant reduction in pain intensity and improvement of HRQL compared to the WL-group, and (ii) the mere establishment of a pain diagnosis and a pain management plan by a pain specialist was not sufficient to enable the referring GP to manage severely chronic pain patients.

Adult↗
PubMed2000

Rapid crossing of the pulmonary endothelial barrier by polyethylenimine/DNA complexes.

Intravenous administration could become a delivery route of choice for prophylactic and curative gene therapies on condition that genes cross the capillary barrier and reach target tissues without being degraded. We investigated the kinetics and process of transgene delivery through mouse lung capillaries following DNA complexation with linear polyethylenimine (L-PEI) and intravenous injection. Using digoxin-labeled DNA we followed the cellular localization of DNA at different times after injection and correlated these findings with cell markers and transgene expression. At 2 h after injection some DNA was still localized on the interior of the capillary lumen, but other complexes had already crossed the barrier and resulted in gene expression. At 24 h after injection most labeled DNA was localised in pulmonary cells, as was transgene expression. Only rarely was transgene expression found in endothelial cells, suggesting that the complexes cross the capillary barrier rapidly. Levels of caspase-1-like activity did not increase following transfection implying that L-PEI/DNA complexes are transported across cellular barriers by a non-damaging, physiological process, without causing inflammation. The high levels of expression of different transgenes in pneumocytes indicates that transport of L-PEI/DNA complexes through the endothelial barrier does not affect their transfection capacity. These findings open up new possibilities for gene delivery and its application to the lung.

Animals↗
PubMed2000

SMR analysis of historical follow-up studies with missing death certificates.

The evaluation of epidemiological follow-up studies is frequently based on a comparison of the number O of deaths observed in the cohort from a specified cause with the expected number E calculated from person years in the cohort and mortality rates from a reference population. The ratio SMR = 100 x O/E is called the standardized mortality ratio (SMR). While person years can easily be calculated from the cohort and reference rates are generally available from the national statistical offices or the World Health Organization (WHO), problems can arise with the accessibility of the causes of death of the deceased study participants. However, the information that a person has died may be available, e.g., from population registers. In this paper, a statistical model for this situation is developed to derive a maximum likelihood (ML) estimator for the true (but unknown) number O* of deaths from a specified cause, which uses the known number O of deaths from this cause and the proportion p of all known causes of death among all decreased participants. It is shown that the standardized mortality ratio SMR* based on this estimated number is just SMR* = SMR/p. Easily computable confidence limits can be obtained by dividing the usual confidence limits of the SMR by the opposite limit of the proportion p. However, the confidence level alpha has to be adjusted appropriately.

Biometry↗