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Dive into the research topics where Wolfgang Kratzer is active.

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Featured researches published by Wolfgang Kratzer.


Journal of Clinical Ultrasound | 1999

Prevalence of gallstones in sonographic surveys worldwide

Wolfgang Kratzer; Richard Andrew Mason; Volker Kächele

The use of diagnostic sonography allows determination of the prevalence of gallstones in a representative sample of the general population. The objective of this article is to review the reports of sonographically based studies of gallstone prevalence in the world literature. All available published epidemiologic studies on the prevalence of cholecystolithiasis as determined by diagnostic sonography are summarized. The sonographically based studies published to date confirm that there are significant regional differences in the prevalence of gallstones. Certain risk factors, notably age and heredity, are present worldwide.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2005

Rapid Effects of Rosiglitazone Treatment on Endothelial Function and Inflammatory Biomarkers

J. Hetzel; Bernd Balletshofer; Kilian Rittig; Daniel Walcher; Wolfgang Kratzer; Vinzenz Hombach; Hans-Ulrich Häring; Wolfgang Koenig; Nikolaus Marx

Background—Antidiabetic thiazolidinediones (TZDs), like rosiglitazone or pioglitazone, improve endothelial function in patients with type 2 diabetes or metabolic syndrome, but it is currently unknown, whether these beneficial effects of TZDs depend on their metabolic action or may be caused by direct effects on the endothelium. Therefore, the present study examined whether short-term rosiglitazone treatment influences endothelium-dependent vasodilation as well as serum levels of vascular disease biomarkers in healthy, nondiabetic subjects. Methods and Results—Short-term treatment (21 days) of healthy subjects (n=10) did not significantly change blood glucose levels or lipid profile. In contrast, rosiglitazone significantly increased flow-mediated, endothelium-dependent vasodilation already within the first day from 5.3±2.7% at baseline to 7.8±2.6%, further increasing it to 9.4±3.0% at day 21. In addition, the early improvement of endothelium-dependent vasodilation was paralleled by a rapid reduction of serum levels of the biomarkers C-reactive protein (CRP), serum amyloid A (SAA), and sE-selectin. Moreover, after drug withdrawal all markers remained suppressed for the whole follow-up period of 7 days. In contrast, rosiglitazone treatment did not significantly affect tumor necrosis factor (TNF)-&agr;, interleukin (IL)-6, sICAM-1, sVCAM-1, and sCD40L levels. Conclusions—Our study suggests a direct effect of TZD treatment on endothelial function and inflammatory biomarkers of arteriosclerosis, promoting the concept that TZDs, independent of their metabolic action, may exhibit protective effects in the vessel wall.


Hepatology | 2004

Structured treatment interruption in patients with alveolar echinococcosis

Stefan Reuter; Andreas K. Buck; Burkhard J. Manfras; Wolfgang Kratzer; Hanns M. Seitz; Kassa Darge; Sven N. Reske; Peter Kern

In human alveolar echinococcosis (AE), benzimidazoles are given throughout life because they are only parasitostatic. It has been a longstanding goal to limit treatment, and recent reports suggest that, in selected cases, benzimidazoles may be parasitocidal. Previously, we showed that positron –emission tomography (PET) using [18F]fluoro‐deoxyglucose discriminates active from inactive lesions in AE. We have now performed a 3‐year prospective study in 23 patients and conducted a structured treatment interruption in those without signs of PET activity. Disease progression was further assessed by ultrasound, computerized tomography, laboratory parameters, and clinical examination.We found PET‐negative lesions in 15 of 23 patients and benzimidazoles were discontinued in these patients. After 18 months, patients were reevaluated, and, of the 15 initially PET‐negative patients, 8 showed either new activity on PET (n = 6) or signs of clinical progression (n = 2). Reinitiation of benzimidazoles halted parasite growth again. No further progression was detected after 36 months. PET had a sensitivity of 91% for the detection of active lesions. In conclusion, despite successful suppression of metabolic activity, in most cases benzimidazoles do not kill the parasite. PET is a reliable tool for assessing metabolic activity and for timely detection of relapses. Neither duration of treatment, kind of treatment, lesion size, calcifications, or regressive changes reliably indicate parasite death. We discourage the discontinuation of benzimidazoles in inoperable AE even after many years of treatment. However, patients with a poor compliance of benzimidazole intake or patients suffering from side effects to benzimidazoles might be assessed for PET negativity. If permanent discontinuation of benzimidazoles is attempted, the course of disease should be followed by PET. (HEPATOLOGY 2004;39:509–517.)


BMC Public Health | 2006

Overweight, physical activity, tobacco and alcohol consumption in a cross-sectional random sample of German adults

Mark Martin Haenle; Stefan O. Brockmann; Martina Kron; Ursula Bertling; Richard Andrew Mason; Gerald Steinbach; Bernhard O. Boehm; Wolfgang Koenig; Peter Kern; Isolde Piechotowski; Wolfgang Kratzer

BackgroundThere is a current paucity of data on the health behaviour of non-selected populations in Central Europe. Data on health behaviour were collected as part of the EMIL study which investigated the prevalence of infection with Echinococcus multilocularis and other medical conditions in an urban German population.MethodsParticipating in the present study were 2,187 adults (1,138 females [52.0%]; 1,049 males [48.0%], age: 18–65 years) taken from a sample of 4,000 persons randomly chosen from an urban population. Data on health behaviour like physical activity, tobacco and alcohol consumption were obtained by means of a questionnaire, documentation of anthropometric data, abdominal ultrasound and blood specimens for assessment of chemical parameters.ResultsThe overall rate of participation was 62.8%. Of these, 50.3% of the adults were overweight or obese. The proportion of active tobacco smokers stood at 30.1%. Of those surveyed 38.9% did not participate in any physical activity. Less than 2 hours of leisure time physical activity per week was associated with female sex, higher BMI (Body Mass Index), smoking and no alcohol consumption. Participants consumed on average 12 grams of alcohol per day. Total cholesterol was in 62.0% (>5.2 mmol/l) and triglycerides were elevated in 20.5% (≥ 2.3 mmol/l) of subjects studied. Hepatic steatosis was identified in 27.4% of subjects and showed an association with male sex, higher BMI, higher age, higher total blood cholesterol, lower HDL, higher triglycerides and higher ALT.ConclusionThis random sample of German urban adults was characterised by a high prevalence of overweight and obesity. This and the pattern of alcohol consumption, smoking and physical activity can be considered to put this group at high risk for associated morbidity and underscore the urgent need for preventive measures aimed at reducing the significantly increased health risk.


Journal of Pediatric Gastroenterology and Nutrition | 2006

Prevalence of gallbladder stone disease in obese children and adolescents: influence of the degree of obesity, sex, and pubertal development.

Volker Kaechele; Martin Wabitsch; Dorothee Thiere; Alexandra Lydia Kessler; Mark Martin Haenle; Hermann Mayer; Wolfgang Kratzer

Objectives: The objective of the present study was to investigate the prevalence of gallbladder stone disease (GD) in a collective of obese children and adolescents and to assess the role of potential influencing factors such as the degree of obesity, sex, age, and pubertal development. Methods: Four hundred ninety-three obese children and adolescents (body mass index standard deviation score [BMI-SDS] > 2.0p) aged 8 to 19 years (218 males, 275 females) were included in the study and underwent ultrasound for detection of GD. Results: Gallbladder stones were detected in 10 of 493 (2.0%; 8 girls, 2 boys) subjects studied. None of the 95 prepubertal children examined were found to suffer from GD. Patients with GD were more severely obese (BMI-SDS 3.4 ± 0.5 vs. 2.7 ± 0.4; P < 0.001) and older (16.1 ± 1.5 vs.13.9 ± 2.0 years; P < 0.008) than children and adolescents without GD. Conclusions: Compared with published data for unselected children an adolescents, the prevalence of GD (2.0%) in obese children and adolescents, previously treated with diet for obesity, is high. Obesity and female sex appear even in children and adolescents to be risk factors for the development of GD. The occurrence of prepubertal GD is rare.


Infection | 2001

Alveolar liver echinococcosis: a comparative study of three imaging techniques.

S. Reuter; K. Nüssle; O. Kolokythas; U. Haug; A. Rieber; P. Kern; Wolfgang Kratzer

AbstractBackground: We compared the imaging findings in patients with alveolar liver echinococcosis using ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI) in a prospective study. Patients and Methods: 30 patients with alveolar echinococcosis (AE) were examined with the above imaging techniques. Results: 30 lesions were detected with all three methods and most lesions (n = 55) were detected with CT. Calcifications were seen in 15 lesions with US, in 21 with CT and in 16 with MRI. MRI best detected necrotic areas and multivesicular structures. Conclusion: US is the screening method of choice and should primarily be complemented by CT due to its ability to detect the greatest number of lesions and clear demarcation of the characteristic calcifications. MRI may facilitate the diagnosis in uncertain cases with noncalcified or partially calcified lesions by showing the characteristic multivesicular structure, necrotic areas and proximity to vascular structures.


Alimentary Pharmacology & Therapeutics | 2003

Therapy of osteoporosis in patients with Crohn's disease: a randomized study comparing sodium fluoride and ibandronate

C. Von Tirpitz; Jochen Klaus; Martin Steinkamp; Lorenz C. Hofbauer; Wolfgang Kratzer; Richard Andrew Mason; B. O. Boehm; Guido Adler; Max Reinshagen

Background : Osteoporosis is a frequent complication in Crohns disease. Although the efficacy of both sodium fluoride and aminobisphosphonates in postmenopausal osteoporosis has been investigated in long‐term therapy studies, no long‐term results are available regarding the effect of these agents in the management of osteoporosis in patients with Crohns disease.


Gastroenterology | 2010

Loci From a Genome-Wide Analysis of Bilirubin Levels Are Associated With Gallstone Risk and Composition

Stephan Buch; Clemens Schafmayer; Henry Völzke; Marcus Seeger; Juan Francisco Miquel; Silvia Sookoian; Jan Hendrik Egberts; Alexander Arlt; Carlos J. Pirola; Markus M. Lerch; Ulrich John; Andre Franke; Oliver von Kampen; Mario Brosch; Michael Nothnagel; Wolfgang Kratzer; Bernhard O. Boehm; Dieter C. Bröring; Stefan Schreiber; Michael Krawczak; Jochen Hampe

BACKGROUND & AIMS Genome-wide association studies have mapped loci that are associated with serum levels of bilirubin. Bilirubin is a major component of gallstones so we investigated whether these variants predict gallstone bilirubin content and overall risk for gallstones. METHODS Loci that were identified in a meta-analysis to attain a genome-wide significance level of a P value less than 1.0×10(-7) (UGT1A1, SLCO1B1, LST-3TM12, SLCO1A2) were analyzed in 1018 individuals with known gallstone composition. Gallstone risk was analyzed in 2606 German choleystecomized individuals and 1121 controls and was replicated in 210 cases and 496 controls from South America. RESULTS By using the presence of bilirubin as a phenotype, variants rs6742078 (UGT1A1; P = .003), rs4149056 (SLCO1B1; P = .003), and rs4149000 (SLCO1A2; P = .015) were associated with gallstone composition. In regression analyses, only UGT1A1 and SLCO1B1 were independently retained in the model. UGT1A1 (rs6742078; P = .018) was associated with overall gallstone risk. In a sex-stratified analysis, only male carriers of rs6742078 had an increased risk for gallstone disease (P = 2.1×10(-7); odds ratio(recessive), 2.34; P(women) = .47). The sex-specific association of rs6742078 was confirmed in samples from South America (P(men) = .046; odds ratio(recessive), 2.19; P(women) = .96). CONCLUSIONS The UGT1A1 Gilbert syndrome variant rs6742078 is associated with gallstone disease in men; further studies are required regarding the sex-specific physiology of bilirubin and bile acid metabolism. Variants of ABCG8 and UGT1A1 are the 2 major risk factors for overall gallstone disease, they contribute a population attributable risk of 21.2% among men.


Scandinavian Journal of Gastroenterology | 2005

Contrast-enhanced wideband harmonic imaging ultrasound (SonoVue®): A new technique for quantifying bowel wall vascularity in Crohn's disease

Wolfgang Kratzer; Stefan A. Schmidt; Christoph Mittrach; Mark Martin Haenle; Richard Andrew Mason; Christian von Tirpitz; Sandra Pauls

Objective. To assess the possibility of quantitative determination of bowel wall vascularity using contrast-enhanced (SonoVue®) wideband harmonic imaging ultrasound and the HDI-Lab software in patients with Crohns disease. Material and methods. Twenty-one patients (13 F, 8 M, average age 33.8±12.7 years, range 21–60 years) with histologically confirmed Crohns disease and bowel wall thickness ≥5 mm were recruited for the study. All ultrasound examinations were performed using a Philips HDI 5000 scanner. Bowel wall vascularity was determined at the site of maximum bowel wall thickness at baseline and at 30, 60, 90 and 120 s following application of the contrast enhancer SonoVue (1.2 ml) using the HDI-Lab software. Results. The mean length of bowel segments exhibiting increased wall thickness was 122.3 mm (range: 23–350±74.7 mm), with a mean wall thickness of 7.6±1.2 mm. Onset of echo enhancement secondary to contrast medium application was observed after an average 13.4 s (range 7–19±4.2 s). Echo intensity corresponding to maximum vascularity was measured 30 s after application of contrast medium. Maximum average contrast medium uptake was 217.5% (range 118–466±100.1%). Conclusions. It is possible to quantify bowel wall vascularity accurately in patients with Crohns disease using contrast-enhanced pulse inversion ultrasound (low-MI).


Digestive Diseases and Sciences | 1998

Gallstone Prevalence in Germany: The Ulm Gallbladder Stone Study

Wolfgang Kratzer; V. Kachele; Richard Andrew Mason; V. Hill; B. Hay; C. Haug; Gail K. Adler; K. Beckh; R. Muche

The Ulm Gallbladder Stone Study is the first ultrasound-based epidemiologic survey of cholecystolithiasis in the former West Germany. A study population of 1116 blood donors (656 men, age 38.0 ± 12.0 years; 460 women, age 34.1 ± 11.2 years) at the Central Blood Bank of the German Red Cross in Ulm was examined between April 1994 and February 1995. Based on age, subjects were assigned to one of four groups (18-30, 31-40, 41-50, and 51-65 years). Following a structured interview of each study subject, an ultrasound examination was carried out and a blood sample obtained for laboratory study. Overall, 6.0% (95% (95% CI: 4.8%-7.6%) of all study subjects (5.8% of the men and 6.3% of the women) exhibited evidence of current or past gallbladder disease (cholelithiasis or history of cholecystectomy). The prevalence of gallbladder disease correlated positively with age, reaching a maximum of 13.7% (9.5-20.0) in the 51- to 65-year-old age group, and also correlated as with body mass index (BMI). Female subjects with previous full-term pregnancies showed a higher prevalence of cholelithiasis, but this difference was not statistically significant for age-adjusted analysis. Subjects with a family history of cholelithiasis were found to suffer from gallstones in 11.5% (8.0-16.7) of cases compared with 4.6% (3.4%-6.3%) of subjects without such family history. Autopsy studies conducted in Germany have shown the prevalence of gallstones to be about 13.1% in men and 33.8% in women. Our sonographic data are relatively low in comparison. This may be due, in part, to the specific selection characteristics inherent in retrospective autopsy studies, such as age distribution and the presence of other pathologic factors associated with increased risk for cholelithiasis. The Ulm data rank in the lower third of the prevalence range reported for European sonographic studies to date. Age, positive family history, and increased BMI all correlated positively with the prevalence of gallbladder disease (P < 0.05). For the study population as a whole, there was no gender-specific increased risk for the development of gallstones.

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Bernhard O. Boehm

Nanyang Technological University

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