Search PubMed⌕ Search

Biomedical subjects

H Becher

Publications and source records attributed to H Becher.

At least 19 recordsLinked to original sources
PubMed2006

A simple method to estimate tobacco-related lung cancer deaths based on smoking prevalence data.

OBJECTIVE: Tobacco is the major cause of cancer and a relevant risk factor for several other chronic diseases. Due to the epidemiological transition in developing countries with overall increasing life expectancy there is an increasing relevance of chronic diseases to the total burden of diseases. Furthermore, there are indications for a rise in the consumption of tobacco products in developing countries. Since in Africa data on smoking prevalence are scarce and cancer diagnosis is often imprecise or missing, it is difficult to estimate the current and future number of cancer cases attributable to tobacco smoking. In this paper, we present an approach to estimate the effects of smoking on lung cancer in selected developing countries in Africa. METHODS: We combined data on smoking prevalence from different African countries with estimates on age-specific lung cancer rates in smokers and non-smokers from industrialized countries and data on age and sex distribution in African countries. We perform a sensitivity analysis to evaluate the effect of the assumptions necessary for the procedure. RESULTS: If the smoking prevalence in African countries will remain on the current level, we estimate age-specific lung cancer rates lower than those in Germany. Despite the relatively small proportion of adults aged 50 and more which is the age when most cancer cases occur, there is an appreciable number of deaths from lung cancer that could be prevented when smoking prevalence could be reduced. Depending on assumptions we estimate up about 50,000 lung cancer deaths per year in Africa, most of which could be prevented. CONCLUSIONS: Efforts for smoking prevalence reduction are much more needed in the developing world. Better and more comprehensive data on smoking are needed for more precise estimates.

Adolescent↗
PubMed2005

Semi-automatic boundary detection to improve reporting of regional left ventricular function.

AIMS: The reporting of regional left ventricular function is based on subjective assessment of endocardial motion and thickening and has a significant learning curve. We hypothesized that the use of an semi-automatic boundary detection system generating images with superimposed moving endocardial borders and a fixed end-diastolic reference border could improve the reporting of regional function. METHODS: We obtained 58 resting contrast images of 15 patients and using a new boundary detection system (Quamus), generated images with superimposed endocardial borders. The contrast images, images with additional Quamus borders and Quamus borders alone were assessed by two level 1 and two level 2 echocardiographers. They scored regional function and results were compared to two level 3 experienced stress echocardiography readers. RESULTS: The addition of borders improved the agreement of level 1 echocardiographers (weighted Kappa increased from 0.55 to 0.64) but did not change for level 2 echocardiographers (0.63 to 0.64) and has the potential to be a useful training tool.

Contrast Media↗
PubMed2005

Absolute temperature, temperature changes and stroke risk: a case-crossover study.

Studies suggest that there is an association between weather patterns and ischemic stroke risk. Exposure to a sudden decrease in temperature may increase stroke risk through altering blood viscosity and/or by triggering infections. We investigated the association between ischemic stroke risk and change in temperature. We used a case-crossover study design with 303 consecutive patients admitted to Heidelberg University, Department of Neurology over a one and a half year period (Aug 1998-Jan 2000). We used one day before stroke as the hazard (case) period matched to two control periods 2-7 days before and after stroke onset and took both ambient maximum temperature and the 24-hour difference in maximum temperature as exposure. There was no risk associated with ambient maximum temperature at all lag times and in all subgroup analyses. For the 24-hour difference, large changes in temperature (>5 degrees C) were associated with an increased risk of acute ischemic stroke regardless of whether the change was negative or positive. The odds ratio for temperature increases >5 degrees C compared to no change in temperature was 2.0 (95% confidence interval (CI): 0.7-5.9) at a lag time of 3 days. We found no relevant relation between temperature and stroke risk. The results suggest that the risk of ischemic stroke may increase with large day-to-day variations upwards or downwards in temperature.

Adolescent↗
PubMed2005

Current indications for contrast echocardiography imaging.

UNLABELLED: The assessment of regional ventricular function is dependent on good endocardial definition. Suboptimal images can be converted to diagnostic recordings in the majority of patients by contrast agents, which have become an indispensable aid in rest and stress echocardiography. In particular for stress echocardiography image quality is essential and contrast administration is of great importance. However this diagnostic procedure must be performed following the indications which reflect the risks of the procedure and consider the benefits of an accurate diagnosis on further patient management. The contraindications recently introduced in the use of the echo-contrast agent SonoVue for acute cardiac patients reflect the same contraindications which have been applied in stress echocardiography for several years. Clinical trials and post-marketing surveillance have demonstrated that this approach is safe with no fatalities reported. For all ultrasound contrast media, side effects have been reported but they are usually mild. However, rare allergic and potentially life threatening reactions may occur and the investigators have to be prepared for such an event with appropriate drugs stored in the echo department. In a recent retrospective analysis in 751 consecutive stress echocardiograms the use of contrast during dobutamine stress echocardiography was not associated with an increased risk of side effects. The incidence of side effects was very low and different in patients receiving Optison, SonoVue or without contrast agent. CONCLUSION: Ultrasound contrast agents are licensed for improvement of endocardial border definition. Data from clinical trials and wide clinical experience indicate an excellent risk/benefit ratio if the current contraindications are applied.

Echocardiography↗
PubMed2005

Stress echocardiography for the diagnosis and risk stratification of patients with suspected or known coronary artery disease: a critical appraisal. Supported by the British Society of Echocardiography.

Stress echocardiography today has matured into a robust and reliable technique not only for the diagnosis of suspected coronary artery disease (CAD) but also for the accurate risk stratification of patients with suspected and established CAD. This is mainly because of rapid advances in image acquisition, digital display, and the development of harmonic and contrast imaging. Stress echocardiography today is also utilised in patients with heart failure both for assessing the cause of heart failure and determining the extent of hibernating myocardium. With advances in myocardial perfusion imaging, stress echocardiography now allows simultaneous assessment of myocardial function and perfusion. Tissue Doppler imaging allows quantitation of wall motion. Ready availability and reliability makes stress echocardiography a cost effective technique for the assessment of CAD.

Aged↗
PubMed2004

Estimation of vasodilator response by analysis of Doppler intensity kinetics with myocardial contrast echocardiography using an intravenous standardized bolus administration.

HYPOTHESIS: Myocardial perfusion can be analyzed by the first pass of Doppler intensity (DI) signals in the myocardium by myocardial contrast echocardiography with triggered power Doppler harmonic imaging (PDHI). METHODS AND RESULTS: DI versus time plots during 1:1 triggering was acquired during a mechanically standardized intravenous bolus application of Levovist (400 mg ml(-1); 3 ml min(-1)) at rest and during vasodilator stress with dipyridamole. Data were analyzed in 21 patients (pts) with normal coronary arteries and in 6 pts with left anterior descending artery (LAD) stenosis. Transthoracic distal LAD-flow velocities could be determined in 7 normal pts. At stress the DI wash-in rate and the DI plateau increased (3.14+/-0.3 versus 5.06+/-0.4 DI s(-1); 24.6+/-2.5 versus 30.8+/-1.8 DI, respectively). To analyze the effect of heart rate on the DI versus time plots investigations were performed in 7 additional controls at rest and during rapid pacing. Heart rates below 100 bpm did not disturb the DI kinetics at 1:1 triggering. CONCLUSIONS: Myocardial perfusion can be assessed by the analysis of the first pass DI kinetics using Levovist. The estimation of vasodilator response by PDHI seems to be an alternative to the determination of coronary flow reserve.

Aged↗
PubMed2004

Myocardial contrast echocardiography demonstrates myocardial hypoperfusion in the LAD territory in patients with acute chest pain at rest--a prospective study using power Doppler harmonic imaging with intravenous bolus application.

AIMS: Using a previously published algorithm we hypothesize that myocardial contrast echocardiography (MCE) with power Doppler harmonic imaging (PDHI) is able to detect regional hypoperfusion within the territory of the left anterior descending artery (LAD) using intravenous (i.v.) injection of contrast in patients (pts) with coronary syndrome at rest. METHODS AND RESULTS: Forty-seven consecutive patients (pts) were prospectively evaluated using a standardized i.v. bolus application of OPTISON. MCE data were acquired within 2 h before angiography. Cut-off Doppler intensity (DI)-values determined in the apical, mid, and basal septum were distinguished between normal and hypoperfused myocardium (e.g. 23.5 and 22.5 dB for maximum DI of the apical or mid-septum triggering on every third heart cycle). Seventeen of 42 pts were classified as normal and the remaining 25 pts as pathologic (10 of these 25 pts had elevated troponines). Angiography detected open vessels or TIMI-III-flow in 15 pts of the normal MCE group, significant stenosis (>70%) or reduced TIMI-flow in 22 pts of the pathologic MCE group. The highest sensitivities (83-92%) were found in the apical septum. CONCLUSION: Assessment of the myocardial perfusion deficits in the LAD territory of pts with acute coronary syndrome is feasible with MCE with PDHI using an i.v. bolus protocol.

Acute Disease↗
PubMed2004

[Determination of the renal blood flow in macro- and microcirculation by means of pulse inversion imaging].

PURPOSE: To evaluate whether real-time and intermittent pulse inversion technology (PI) allows the analysis of blood flow in renal macro- and microcirculation. MATERIALS AND METHODS: The experiments were performed in a kidney perfusion phantom as an experimental model for the assessment of contrast replenishment in vascular regions of high flow velocity (medulla) and low flow velocity (cortex). During continuous infusion (0.03 ml/min) of Optison, contrast replenishment kinetics were assessed with intermittent PI at high emission power (MI: 1.3, with increasing trigger intervals) and with real-time PI at low emission power (MI: 0.09) at variable renal arterial blood flow (15 - 65 ml/min), using an HDI-5000 ultrasound unit (Philips Medical Systems). Regions of interest were placed in the major arteries of the medulla and the renal cortex to obtain replenishment curves of the macro- and microcirculation. Non-linear curve fitting was performed using the mathematical model y = A (1-e (-beta t)) with A as the parameter describing blood volume and beta as the parameter describing the speed of contrast replenishment. RESULTS: Replenishment curves could be obtained in all analyzed renal segments. For intermittent and real-time PI a strong linear correlation was found between renal arterial blood flow and A*beta (intermittent PI: cortex: R = 0.97; medulla: R = 0.98; real-time PI: cortex: R = 0.99; medulla: R = 0.96). The differences between the slopes of the regression lines (cortex: high power vs. low power, p = 0.844; medulla: high power vs. low power, p = 0.444) were not significant. CONCLUSION: Intermittent and real-time PI allows the assessment of renal blood flow in different vessel compartments.

Albumins↗
PubMed2004

Prospective molecular epidemiological study on transmission of pulmonary Tuberculosis and Migration (MuT study) -- an interim report.

INTRODUCTION: In Western Europe prevalence and incidence of tuberculosis in the indigenous population is declining and TB in migrants from high prevalence countries is becoming a major issue of TB control. Resulting changes in transmission patterns need to be investigated to adapt control strategies. The MuT (Migration and Tuberculosis) study a co-operation among federal and local public health services (ODG), the National Surveillance Center (RKI) and the University has been established in Baden-Wuerttemberg to address these issues. OBJECTIVES: The goal of this ongoing study is to determine the transmission dynamics of TB in Baden-Wuerttemberg. Here, we present the first set of data on TB cases and their contacts and discuss strategies to overcome arising difficulties. METHODS: Prospective data collection of culture positive pulmonary tuberculosis cases and their contacts. Analysis of (1) routine data, (2) spatial data, (3) social interaction data, (4) molecular typing data, and (5) observational data of the implementation phase. RESULTS: The study demonstrates the capability of the study consortium to identify clusters. It provides valuable insights into current case detection and case management procedures and shows ways to improve. A set of factors has been identified that (a) facilitate and (b) discourage study participation. CONCLUSION: Collaboration among federal and local public health services (OGD), National Surveillance Center (RKI) and the University is a promising approach to investigate and improve TB control. This model has potentials for other infectious disease control.

Epidemiologic Studies↗
PubMed2004

Interaction effects and population-attributable risks for smoking and alcohol on laryngeal cancer and its subsites. A case-control study from Germany.

OBJECTIVES: To assess the joint effect of smoking and alcohol consumption on laryngeal risk on tumor subsites. METHODS: Population-based case-control study in South-West Germany with 257 histologically confirmed cases (236 males, 21 females), age 37 to 80 years, and 769 population controls (702 males, 67 females), 1:3 frequency matched by age and sex. RESULTS: Half of the tumors (50.6%) were glottic or subglottic, 17.5% were supraglottic. Due to advanced stage, the subsite of 31.9% of the tumors could not be determined clearly. There is a strong increase in risk with increasing tobacco consumption with an odds ratio (OR) of 59.8 (95% confidence interval (CI) 21.3-167.3) for heavy smoking (>80 packyears (py)), all cases combined. In comparison to current smokers, cancer risk is reduced for ex-smoking (>2 years) OR=0.36, 95% CI 0.24-0.53. The risks were higher for supraglottic than for glottic and subglottic tumors. The effect of alcohol is not as strong. A significantly increased odds ratio of 2.0, 95% CI (1.0-3.9) results for 75-100 g ethanol/day only for glottic and subglottic tumors. The OR rises from 2.2, 95% CI (1.1-4.3) for 100-150 g ethanol/day to 4.3, 95% CI (1.4-13.2) for more than 150 g ethanol/day (all models adjusted for education). The joint effect of smoking and alcohol results appears sub-multiplicative but super-additive. Almost 90% of the tumors can be attributed to both factors. CONCLUSION: Contrary to earlier investigations we observed a sub-multiplicative effect of smoking and alcohol. The risk for persons with both high alcohol and tobacco consumption is extremely high which indicates the importance of intervention.

Aged↗
PubMed2003

Myocardial contrast echocardiography for assessment of myocardial perfusion at rest in a patient with left main coronary artery stenosis.

The present case will focus on the potential of hypoperfusion detection with myocardial contrast echocardiography (MCE) using power Doppler harmonic imaging (PDHI). PDHI is normally performed in a triggered mode. Microbubbles were destroyed by the ultrasound energy in the myocardium, and myocardium has to be refilled with microbubbles within the time interval between the ultrasound pulses to obtain repetitive information about perfusion. Using the contrast agent Levovist, however, real-time PDHI also results in myocardial opacification presumably due to perfusion signals of the arteriolar microbubble passage. A 45-year-old woman with typical stress-induced angina was admitted to our department for cardiac catheterization. Prior to the angiography a conventional echocardiogram showed normal left ventricular function. Tissue Doppler, however, demonstrated postsystolic longitudinal shortening of the septal, anterior, and lateral wall regions. Myocardial contrast echocardiography with triggered PDHI showed complete opacification of the myocardium at rest. Using real-time PDHI with Levovist, the septum could not be opacified. The consecutive angiography documented a severe unprotected main coronary artery stenosis. After angioplasty and stent implantation, MCE measurements were repeated. Repetitive intravenous bolus injections of Optison during triggered PDHI showed no differences to the investigation prior to the angioplasty. Using real-time PDHI with Levovist, however, there was a marked difference in comparison to the pre-interventional analysis. A complete opacification of the apical septum was observed. The present case suggests that different MCE techniques can analyze different compartments of the myocardial vasculature in clinical practice. This methodological comparison between triggered and real-time PDHI shows obviously differences in the DI signal detection due to the different microbubble behavior. Clinicians should be aware of the potentials of MCE to improve noninvasive diagnostic procedures in patients with ischemic heart disease.

Albumins↗
PubMed2003

Assessment of regional myocardial hypoperfusion with myocardial contrast echocardiography using intravenous bolus application in patients with acute chest pain: a double case report.

Myocardial contrast echocardiography using power Doppler harmonic imaging is able to document myocardial hypoperfusion. Two case reports demonstrate the potential of intravenous bolus application of microbubbles in patients with acute chest pain due to myocardial ischaemia to detect regional low flow conditions. The case reports will focus on the necessity to present Doppler intensity kinetics by Doppler intensity vs time plots or coloured M-modes to present the data more objectively. In addition, the hypoperfusion detected with myocardial contrast echocardiography via bolus injection of microbubbles can only be proven by changes of regional perfusion between repetitive myocardial contrast echocardiography measurements or by additional perfusion analysis, e.g. by scintiscanning.

Acute Disease↗
PubMed2003

Primary cardiac lymphoma.

We present a case of primary cardiac lymphoma, which is a rare condition compared with secondary metastatic involvement and is associated with poor prognosis. This case demonstrates the use of transthoracic echocardiography for the assessment of tumour regression in response to chemotherapy.

Aged↗
PubMed2003

Intravenous myocardial contrast echocardiography during angioplasty.

Myocardial contrast echocardiography (MCE) using power Doppler harmonic imaging (PDHI) has been reported to document regional myocardial perfusion. Two case reports demonstrate the potential of intravenous myocardial contrast echocardiography during angioplasty.

Angioplasty, Balloon↗
PubMed2003

Effect of zinc supplementation on growth in West African children: a randomized double-blind placebo-controlled trial in rural Burkina Faso.

OBJECTIVE: To analyse the effects of zinc supplementation on growth parameters in a representative sample of young children in rural Burkina Faso. Design Randomized, double-blind, placebo-controlled efficacy trial. Setting Eighteen villages in rural northwestern Burkina Faso. Subjects In all, 709 children aged 6-31 months were enrolled; 685 completed the trial. Intervention Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for 6 days a week for 6 months. Outcomes Weight, length/height, mid-arm circumference, and serum zinc. RESULTS: In a representative subsample of study children, 72% were zinc-deficient at baseline. After supplementation, serum zinc increased in zinc-supplemented but not in control children of the subsample. No significant differences between groups were observed during follow-up regarding length/height, weight, mid-arm circumference, and z scores for height-for-age, weight-for-age, and weight-for-height. CONCLUSIONS: We conclude that zinc supplementation does not have an effect of public health importance on growth in West African populations of young children with a high prevalence of malnutrition. Multinutrient interventions are likely to be more effective.

Anthropometry↗