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J Menzel

Publications and source records attributed to J Menzel.

At least 19 recordsLinked to original sources
PubMed2006

Excimer laser pumped by an intense, high-energy heavy-ion beam.

High-energy heavy ions are an ideal tool to generate homogeneously excited, extended volumes of nonthermal plasmas. Here, the high-energy loss (dE/dx) and absolute power deposition of heavy ions interacting with matter has been used to pump an ultraviolet laser. A pulsed 70 MeV/u 238U beam with up to 2.5 x 10(9) particles in approximately 100 ns beam bunches was stopped in a 1.2 m long laser cell filled with a 1.6 bar Ar-Kr-F2 mixture (typically 50%:49.9%:0.1%). Laser effect on the 248 nm KrF* excimer transition is clearly demonstrated.

Journal Article↗
PubMed2005

Endosonographic and histopathological staging of extrahepatic bile duct cancer: time to leave the present TNM-classification?

OBJECTIVES: The discrepancy between high rates of sensitivity, specificity, and accuracy for intraductal ultrasonography (IDUS) in extrahepatic bile duct carcinoma and the failure to depict different wall layers as defined by the TNM classification have not yet been elucidated sufficiently. METHODS: In a prospective study, endosonographic images were correlated with histomorphology including immunohistochemistry. Using IDUS, we examined fresh resection specimens of patients who had undergone pancreato-duodenectomy. For histological analysis, the formalin-fixed and paraffin-embedded specimens were stained by hematoxylin-eosin, elastica-van-Gieson, and immunohistochemically by smooth muscle-actin. To confirm our hypothesis, further cases from the archives were analyzed histopathologically and immunohistochemically. RESULTS: The various wall layers of the extrahepatic bile duct as described by the International Union Against Cancer are neither histomorphologically nor immunohistochemically consistently demonstrable. Especially, a clear differentiation between tumor invasion beyond the wall of the bile duct (T2) and invasion of the pancreas (T3) by histopathological means is often not possible. Endosonographic images using high-resolution miniprobes similarly confirm the difficulty in imaging various layers in the bile duct wall. CONCLUSIONS: Most adaptations made by the sixth edition of the TNM classification accommodate to the endosonographic and most of the histopathological findings as demonstrated in our study. In contrast to the new edition, however, our findings suggest to combine T2- and T3-staged tumors into one single class leading to clarification, and improved reproducibility of histopathological staging.

Aged↗
PubMed2004

[Requirements and recommendations for performing endosonographies].

For improvement of quality the working group of the Society of Gastroenterology in Nordrhein-Westfalen (Germany) was engaged with the questions, which apparative, personal and training conditions for endoscopic ultrasound are useful. The following proposals were preliminarily presented at the annual Congress of the DGVS (German Society of Digestive and Metabolic Diseases) 2001. They are thought to be subject of discussion for guidelines to be elaborated by this national society.

Biopsy, Needle↗
PubMed2003

Papillary mesothelioma of the peritoneum in the absence of asbestos exposure.

BACKGROUND: Malignant mesothelioma of the peritoneum is a very rare neoplasm, commonly associated with asbestos exposure and often rapidly fatal. Well Differentiated Papillary Mesothelioma of the Peritoneum (WDPMP) is regarded as a less aggressive variety of the tumor. Progressive ascites is often the only clinical manifestation of the disease and differentiation of WDPMP from benign mesothelial hyperplasia or adenocarcinoma is difficult. PATIENTS AND METHODS: Here we report the case of a 45-year-old patient who presented with ascites but without evidence of portal hypertension, liver disease or abdominal malignancy. On diagnostic laparoscopy small tumor nodules were found to cover the parietal peritoneum and the greater omentum and histopathologically corresponded to papillary mesothelial hyperplasia with minimal nuclear atypia. Histochemically biopsies were positive for Calretinin, Cytokeratins and Epithelial Membrane Antigen (EMA). Based on these findings the diagnosis of WDPMP was made and the patient was closely followed without primary cytostatic therapy. CONCLUSIONS: Progressive ascites was the only clinical symptom in this patient, while liver disease, portal hypertension and gastrointestinal malignancies were ruled out by clinical, laboratory and imaging techniques. Laparoscopic biopsy revealed WDPMP to be the underlying disease. Immunocytochemistry is required to establish the diagnosis of this rare malignant disorder which is even more uncommon in the absence of a history of asbestos exposure. Due to the indolent course of WDPMP therapy should only be initiated when signs of rapid tumor progression become apparent.

Asbestosis↗
PubMed2003

Pancreatic intraductal ultrasonography (IDUS) allows early diagnosis of pancreatic carcinoma in situ: a case report.

A 66-year-old woman was admitted with diarrhea, weight loss, slight recurrent abdominal pain, and raised serum amylase and lipase. Lactose intolerance was diagnosed, and treatment was begun. The symptoms diminished. However, slight back pain and elevated serum amylase and lipase levels persisted. A pancreatic tumor was then suspected. Ultrasound, spiral computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance cholangiopancreatography (MRCP) examinations were inconclusive. Endoscopic retrograde cholangiopancreatography (ERCP) showed a slight narrowing of the pancreatic duct within the pancreatic body, and endoscopic ultrasound (EUS) revealed a 10 mm intrapancreatic lesion. Finally, intraductal ultrasonography (IDUS) reliably identified a small pancreatic tumor. The tumor was resected, and histology confirmed a well-differentiated adenocarcinoma in situ (UICC stage 0, TisN0M0). This case shows that using high-resolution imaging techniques such as EUS plus IDUS, small malignant pancreatic lesions can be detected at an early stage, when curative action is possible.

Aged↗
PubMed2003

[Endoscopic ultrasound in the long-term follow-up of primary lymphomas of the stomach under conservative therapy].

BACKGROUND AND AIMS: The stomach is the main site of primary extranodular manifestation of non-Hodgkin's lymphomas. Besides clinical staging additional to histological diagnoses, the endoscopic ultrasound (EUS) also becomes more important during follow-up courses of conservative therapy regimens (e. g. H.p. eradication; radiochemotherapy). The aim of the present study was to assess the impact of EUS during long-term observation of primary gastric lymphomas and to outline possible changes of the gastric wall. PATIENTS AND METHODS: Within the scope of 2 prospective multicenter study on primary gastrointestinal non-Hodgkin's lymphomas (GIT-NHL), which were performed at Muenster University Hospital, 26 patients undergoing conservative treatment were examined with endoscopic ultrasound at a three-month interval between 01/1992 and 11/1998. The mean survey period was 28 months (range 7-62). RESULTS: In 22 patients over a period of 21 months (range 4-51) a histological proven complete remission (CR) was found. In 2 patients only a partial remission (PR) was achieved within a time period of seven respectively eight months of survey. Two other patients developed early relapse of non-Hodgkin's lymphoma. In patients with CR the endoscopic ultrasound showed a highly significant decrease of gastric wall thickness 7 and 12 months after therapy was started. On average after 4.6 months enlarged lymph nodes were no more detectable, after 5.5 months thickness of the gastric wall and finally after 6.6 month the previous abolished layering of the gastric wall returned to normal. CONCLUSION: In patients with gastric non-Hodgkin's lymphomas endoscopic ultrasound seems to be the only valid method which demonstrates early changes of the gastric wall and its layering in an appropriate way and might therefore in addition be capable to differentiate between CR, recurrent or refractory non-Hodgkin's lymphoma.

Adult↗
PubMed2002

Generation of GW radiation pulses from a VUV free-electron laser operating in the femtosecond regime.

Experimental results are presented from vacuum-ultraviolet free-electron laser (FEL) operating in the self-amplified spontaneous emission (SASE) mode. The generation of ultrashort radiation pulses became possible due to specific tailoring of the bunch charge distribution. A complete characterization of the linear and nonlinear modes of the SASE FEL operation was performed. At saturation the FEL produces ultrashort pulses (30-100 fs FWHM) with a peak radiation power in the GW level and with full transverse coherence. The wavelength was tuned in the range of 95-105 nm.

Journal Article↗
PubMed2002

High-dose interferon alpha-2a with ribavirin and amantadine in naïve chronic hepatitis C patients--results of a randomized, prospective, pilot study.

BACKGROUND: Hepatitis C viral kinetic studies have demonstrated the increased anti-viral effect of higher than standard dosages of interferon and of daily treatment schedules. AIM: To compare, in a prospective, randomized, controlled trial, the efficacy and safety of high-dose interferon-alpha therapy vs. standard-dosage interferon-alpha therapy, in a triple therapy combination with ribavirin and amantadine. METHODS: Previously untreated patients with chronic hepatitis C were randomized to the standard interferon-alpha group (n = 15), receiving thrice weekly 6 MU interferon-alpha for 12 weeks, followed by 3 MU interferon-alpha for 36 weeks, or the high-dose interferon-alpha group (n = 15), receiving daily 9 MU interferon-alpha for 4 weeks, followed by 6 MU (weeks 5-8), 3 MU (weeks 9-12) and 1.5 MU (weeks 13-48) interferon-alpha. All patients were given ribavirin (1000-1200 mg) and amantadine (200 mg) daily for 48 weeks. RESULTS: At the end of treatment and after the 24-week follow-up period, serum hepatitis C virus RNA was undetectable in eight (53%) and six (40%) patients treated with standard-dosage interferon-alpha, respectively, compared with 11 (73%) and 10 (67%) treated with high-dose interferon-alpha, respectively (not significant). The safety profile of both treatment regimens was similar. Severe adverse events leading to withdrawal from the study occurred in one patient (7%) in each group, and in both groups one patient (7%) was lost during therapy for unknown reasons. CONCLUSIONS: The findings suggest that, although the difference between the response rates of standard and high-dose interferon-alpha regimens (within a triple anti-viral therapy combination) did not reach statistical significance, there was a clear trend towards a higher response with high-dose interferon-alpha therapy and an equal safety profile.

Adult↗
PubMed2002

[The value of magnetic resonance imaging (MRI) for the follow-up of patients with transjugular intrahepatic portosystemic shunts (TIPS)].

PURPOSE: To prospectively determine the value of magnetic resonance imaging (MRI) with flow quantification in the portal vein for the follow-up of patients with transjugular intrahepatic portosystemic shunt (TIPS). METHODS: Thirty-six patients with TIPS (23 m, 13 f) were evaluated with MR of the liver parenchyma and quantification of flow in the portal vein. MR examinations were correlated with Doppler sonography and conventional angiography including measurement of the portal pressure gradient (PPG). In cases of re-interventions (dilatation/stent application) additional examinations with MRI and Doppler sonography were performed. RESULTS: MR flow measurements in the portal vein correlated with Doppler sonography (r = 0.69) whereas no correlation of both methods with the PPG was found. No threshold velocity in the portal vein could be determined to predict shunt stenosis. All shunt occlusions (n = 5) were diagnosed correctly by MRA. Thirty measurements before and after successful angiographic interventions revealed a significant increase in portal flow velocity and a significant decrease of the PPG. Magnetic resonance images enabled a reliable detection of procedural complications (parenchymal bleedings, n = 31; extra and subcaspular hematomas, n = 2 each) and newly occurring hepatocellular carcinomas (n = 2) in the follow-up period. CONCLUSION: Magnetic resonance imaging in the follow-up of TIPS enables a morphological assessment of the liver and an accurate velocity mapping, but is not suited to predict shunt dysfunction as a single method.

Aged↗
PubMed2002

[Decompressive craniectomy for severe intracranial hypertension due to cerebral infarction or meningoencephalitis].

We describe the clinical course and outcome following decompressive craniectomy in six patients. Five patients suffered from severe intracranial hypertension due to middle cerebral artery infarction. In one patient the cause was bacterial meningoencephalitis. Acute clinical and neuroradiological signs of intracranial hypertension were seen in all cases. Following ineffective conventional brain edema therapy, decompressive craniectomy was undertaken. In five cases intracranial pressure was sufficiently lowered. One patient developed transtentorial herniation with subsequent brain death. Four patients with middle artery infarction showed moderate neurological disorders and one patient with bacterial meningoencephalitis recovered completely after treatment. Craniectomy in malignant middle artery infarction should be taken into consideration if conventional brain edema therapy does not sufficiently reduce critically raised intracranial pressure. Craniectomy provides development of brain herniation. This treatment may reduce high lethality rate and high frequency of severe neurological disorders.

Adolescent↗
PubMed2002

Endoscopic transpapillary biopsies and intraductal ultrasonography in the diagnostics of bile duct strictures: a prospective study.

BACKGROUND: In bile duct strictures, examination of wall layers by intraductal ultrasonography (IDUS) performed during endoscopic retrograde cholangiopancreatography (ERCP) may be diagnostically useful. METHODS: In the present study 60 patients with bile duct strictures of unknown aetiology were examined preoperatively by ERCP, including transpapillary biopsies and IDUS. Histopathological correlation was available for all patients undergoing these procedures. RESULTS: Postoperative diagnosis revealed 30 pancreatic carcinomas, 17 bile duct cancers, three gall bladder cancers, and 10 benign bile duct strictures. Using endoscopic transpapillary forceps biopsies (ETP), a correct preoperative diagnosis was achieved in 36 of 60 patients (60% of cases). Among the 50 malignant tumours, preoperative diagnosis by ETP revealed a sensitivity of 52% and a specificity of 100%. ERCP supplemented by IDUS allowed for correct preoperative diagnosis in 83% of cases (50 of 60 patients), which was significantly higher than the accuracy of ETP (p=0.008). By combining ETP with IDUS, a correct preoperative diagnosis was made in 59 of 60 patients resulting in an accuracy rate of 98%. CONCLUSIONS: Because of its low accuracy, exclusive use of ETP is not a reliable diagnostic tool for a definitive preoperative diagnosis of bile duct strictures. By combining IDUS and ETP with ERCP however, preoperative diagnostic accuracy can be improved substantially.

Adolescent↗
PubMed2001

[Fulminant liver failure after administration of the herbal antidepressant Kava-Kava].

HISTORY AND CLINICAL FINDINGS: A 60 year-old woman was admitted to hospital because of jaundice, fatigue, weight loss over several months and icteric skin. Because of progressive liver failure, concomitant renal failure and progressive encephalopathy she was transferred to an intensive care unit. INVESTIGATIONS: Biochemical tests revealed acute liver failure with high levels of total and conjugated bilirubin (30 mg/dl) as well as aspartate aminotransferase (921 IU/l) and alanine aminotransferase (1350 IU/l) concentrations. Prothrombin time was less than 10 %. Serological tests could rule out viral hepatitis, metabolic or autoimmune causes of liver failure. On abdominal computed tomography and ultrasonography no pathological changes were detected. Above all portal vein thrombosis, ascites, focal lesions of the liver and extrahepatic cholestasis could be excluded. Liver histology showed extensive hepatocellular necrosis with intrahepatic cholestasis. TREATMENT AND CLINICAL COURSE: The patient's physical condition deteriorated. She had to be intubated because of respiratory insufficiency and encephalopathy stage IV. Because of progressive liver failure under conservative treatment the patient received an orthotopic liver transplant 11 days after admission. CONCLUSIONS: The exclusion of other causes and the histological diagnosis made Kava-Kava as the cause of acute liver failure most likely. This is the 18th case of Kava-Kava induced liver failure reported to the European regulatory authorities.

Alanine Transaminase↗
PubMed2001

Intraductal ultrasound in the biliary tract.

Although endoscopic ultrasonography (EUS) represents a major advance in endoscopic imaging, endosonography using dedicated echoendoscopes has some serious drawbacks, including the diameter of the echoendoscope (12 to 13 mm), the lack of intraluminal examination of the pancreatobiliary duct system due to the size of the instrument, unsatisfactory image quality and resolution for small lesions, and the need for a second examination separate from the previous routine endoscopy. Recently developed ultrasonographic miniprobes (diameter, about 2 mm; frequency, 12 to 20 MHz) can be passed through the working channel of standard endoscopes to provide high-frequency ultrasound images. These miniprobes may overcome some of the noted drawbacks and add to the safety and convenience of patients. Moreover, in various diseases of the gastrointestinal tract and the pancreatobiliary ductal system, the diagnostic accuracy of miniprobe ultrasonography has been proven to be superior to that of EUS. Miniprobe ultrasonography is a promising tool that adds new capabilities to the armamentarium of gastroenterologic diagnostic assessment.

Biliary Tract↗
PubMed2001

Helicobacter pylori-negative gastric ulcerations associated with celiac disease at first presentation.

Ulcers of the small bowel have repeatedly been described as a late complication of celiac disease and they are considered a signum mali ominis. We report a case of a 53-year-old woman presenting with diarrhea, epigastric pain and abdominal distensions for a period of few weeks. At upper GI endoscopy, biopsies were taken showing complete atrophy of the villi and colonization of the small bowel mucosa. Additionally, uncommon multilocular peptic ulcers were seen in the gastric antrum. These ulcers proved to be Helicobacter pylori-negative with no evidence of Zollinger-Ellison syndrome. Biopsies of gastric ulcers showed signs of a lymphocytic gastritis with an extensive infiltration of the lamina propria by almost exclusively CD3- and CD45R0-positive T-lymphocytes. Intraepithelial T-lymphocytes were found to be increased in the antral as well as the corpus mucosa. Typing the patient for human leukocyte antigens showed a DQA1*0501 and DQB1*0201 phenotype. According to the present report, gastric peptic ulcers seem to be another phenomenon associated with celiac disease. In the case presented here, ulcers were diagnosed together with celiac disease already at first presentation of the patient.

Biopsy↗
PubMed2001

Impact of miniprobes compared to conventional endosonography in the staging of low-grade gastric malt lymphoma.

BACKGROUND AND STUDY AIMS: In patients with low-grade gastric MALT lymphoma, conventional endoscopic ultrasonography (EUS) is considered to be the most accurate modality for locoregional staging. The aim of this study was to evaluate the diagnostic role of ultrasonic miniprobes as part of routine clinical staging. PATIENTS AND METHODS: A total of 39 patients who were histologically diagnosed with low-grade MALT lymphoma were reviewed retrospectively before treatment (n = 15) and during follow-up (n = 24). Assessment of tumor penetration into the gastric wall was based on the TNM system. Pathological lymph-node involvement was suggested by the presence of inhomogeneous hypoechoic echo patterns, with clearly demarcated borders. All examinations were carried out using a mechanical miniprobe (Olympus; diameter 2.4 mm, 12 MHz) introduced through the working channel of the endoscope. Ultrasonic miniprobe findings were compared with conventional EUS data and histology. RESULTS: Using pretreatment endoscopic ultrasonography, gastric lymphomas presented endoscopically with an ulcer (in five of 15 patients) or a diffuse infiltrative pattern (ten of 15 patients). The ultrasonic miniprobe identified a T1 lesion in 53 % (T2, 33 %) and EUS in 60 % (T2, 20 %) of cases. Pathological lymph-node involvement in T1-T2 lesions was diagnosed with the ultrasonic miniprobe in 53 % of cases and with EUS in 60 %. Using endoscopic ultrasonography during the follow-up period, in patients with normal miniprobe ultrasonography (n = 15), the histological examination confirmed a complete remission in all patients. Hypoechoic thickening of the mucosa or submucosa, or both, was seen in nine patients. Endoscopic biopsies in four of these nine patients revealed recurrent lymphoma. CONCLUSIONS: The ultrasonic miniprobe can be recommended as part of routine care in patients with gastric MALT lymphoma, both initially and during the follow-up period. The clinical significance of ultrasonic miniprobe examinations is that they can be performed as a single-step procedure during diagnostic endoscopy.

Adult↗