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Biomedical subjects

H Becker

Publications and source records attributed to H Becker.

At least 37 records · Page 2Linked to original sources

[Significance of occult lymphatic tumor spread in pancreatic cancer].

PURPOSE: The aim of this study was to determine the frequency and effect on prognosis of occult tumor cells in regional lymph nodes judged to be tumor-free in conventional histopathology of pancreatic cancer patients. PATIENTS AND METHODS: Among 115 patients who underwent pancreatic resection for pancreatic (n=84) or distal common bile duct malignancy (n=12) or carcinoma of the papilla (n=19), 48 (42%) were staged pN0. Archival paraffin blocks of 271 resected regional lymph nodes of 41 pN0 patients were reevaluated for occult tumor cells using monoclonal antibody Ber-EP4. Cases with or without isolated tumor cells were compared regarding the distribution of various clinicopathological factors. RESULTS: Of 41 pN0 patients, 16 (39%) exhibited single Ber-Ep4 immunoreactive cells or small cell clusters in at least one lymph node. The occurrence of occult tumor cells was not dependent on other clinicopathological factors such as pT stage, grading, or curative resection. However, those cells were encountered more frequently in common bile duct carcinomas (100%) than in pancreatic (36%) or papilla (20%) carcinomas (P=0.009). Occult tumor cells impaired prognosis significantly in uni- and multivariate analyses (estimated 5-year survival 53% for pN0((i-)) vs 10% for pN0((i+)) and 9% for pN1/N2; P=0.0047). CONCLUSION: Occult tumor cells are frequent in apparently tumor-free lymph nodes of pancreatic cancer patients and often overlooked in conventional histopathology. They are encountered even in limited stages of disease and they impair prognosis, which is comparable to that of patients with true lymphatic metastases. Occult tumor cells in lymph nodes of pancreatic cancer patients could be used to stratify adjuvant therapy.

Aged↗

[Cardiovascular monitoring of patients with systemic lupus erythematosus].

Accelerated atherosclerotic cardiovascular disease is increasingly recognized as a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Cardiac manifestations of SLE are frequent and can involve almost all components of the heart. Pulmonary hypertension often develops during the course of SLE. The high incidence of cardiovascular complications may justify a screening of SLE patients in order to ensure early diagnosis and therapy. Results of diagnostic procedures that detect coronary insufficiency, surrogates of atherosclerotic burden and echocardiographic findings are often abnormal in SLE. However, evidence to support a routine screening for cardiovascular disease is currently not available. Therefore, based on the recommendations that have been proposed for other conditions associated with cardiovascular disease, we suggest assessment of risk factors and the performance of echocardiography at least annually in asymptomatic SLE patients. If two or more risk factors are present, an exercise ECG is recommended. The benefit, however, of screening SLE patients for cardiovascular disease has to be confirmed in prospective studies.

Cardiovascular Diseases↗

[Nocturnal long-term recording of breath sounds in patients with bronchial asthma -- a reasonable diagnostic option?].

Alterations in normal breath sounds are an important indication of pathophysiological processes in the bronchial system and the lung. In the presence of non-specific symptoms like dyspnea, wheezing or cough while sleeping it seems reasonable to make a nocturnal long-term recording of breath sounds. Thus specific auscultation phenomena can be recorded qualitative and particularly quantitative in the course. A mobile recording system provides a non-invasive monitoring at home which is independent of vigilance. Furthermore it can be used for follow-up examinations of medical interventions.

Asthma↗

Mood and affect during detoxification of opiate addicts: a comparison of buprenorphine versus methadone.

Twenty-six in-patients with Diagnostic and Statistical Manual version IV (DSM-IV) criteria for opioid dependence were selected at random to receive either a combination of an 11-day low-dose buprenorphine and a 14-day carbamazepine regimen (n = 14) or a combination of an 11-day methadone and a 14-day carbamazepine regimen (n = 12) in a double-blind, randomized 14-day in-patient detoxification treatment. Patients with buprenorphine and carbamazepine showed a significantly better psychological state after the first and second weeks of treatment. Above all, the buprenorphine-treated patients demonstrated a less marked tiredness, sensitiveness and depressive state as well as a more prominent elevated mood during the detoxification process. Seven non-completers (after 7 days: four of 12 = 33.3%; after 14 days: seven of 12 = 58.3%) were treated with methadone and carbamazepine and five non-completers (after 7 days: two of 14 = 14.3%; after 14 days: five of 14 = 35.7%) received buprenorphine and carbamazepine. The difference in the overall dropout rate after day 14 was not significant. The present study supports the hypothesis that the combination of buprenorphine and carbamazepine leads to a better clinical outcome than does a combination of methadone and carbamazepine in the detoxification of opioid addicts with additional multiple drug abuse. The buprenorphine and carbamazepine-regimen provides a more effective short-term relief of affective disturbances than does methadone and carbamazepine. No severe side effects occurred during the treatment period in both groups.

Adult↗

Autofluorescence bronchoscopy with white light bronchoscopy compared with white light bronchoscopy alone for the detection of precancerous lesions: a European randomised controlled multicentre trial.

BACKGROUND: The potential of autofluorescence bronchoscopy (AFB) to detect precancerous lesions in the central airways and its role in lung cancer screening is uncertain. A study was undertaken to evaluate the prevalence of moderate/severe dysplasia (dysplasia II-III) and carcinoma in situ (CIS) using a newly developed AFB system in comparison with conventional white light bronchoscopy (WLB) alone. METHODS: In a prospective randomised multicentre trial, smokers > or = 40 years of age (> or = 20 pack-years) were stratified into four different risk groups and investigated with either WLB+AFB (arm A) or WLB alone (arm B). RESULTS: 1173 patients (916 men) of mean age 58.7 years were included. Overall (arms A and B), preinvasive lesions (dysplasia II-III and CIS) were detected in 3.9% of the patients. The prevalence of patients with preinvasive lesions in the WLB arm was 2.7% compared with 5.1% in the WLB+AFB arm (p = 0.037). For patients with dysplasia II-III, WLB+AFB increased the detection rate by a factor of 2.1 (p = 0.03), while for CIS the factor was only 1.24 (p = 0.75). The biopsy based sensitivity of WLB alone and WLB+AFB for detecting dysplasia II-III and CIS was 57.9% compared with 82.3% (1.42-fold increase). The corresponding specificity was 62.1% compared with 58.4% (0.94-fold decrease). CONCLUSIONS: This first randomised study of AFB showed that the combination of WLB+AFB was significantly superior to WLB alone in detecting preneoplastic lesions. Our findings do not support the general use of AFB as a screening tool for lung cancer, but suggest that it may be of use in certain groups. The precise indications await further study.

Adult↗

Apoptosis inducing activity of viscin, a lipophilic extract from Viscum album L.

Detection of antiproliferative activity and bioactivity-guided fractionation of viscin, a lipophilic extract from Viscum album L., led to the isolation of betulinic acid, oleanolic acid and ursolic acid as active components. Viscin, betulinic acid, oleanolic acid and ursolic acid inhibited growth and induced apoptotic cell death in Molt4, K562 and U937 leukaemia cells. The growth inhibitory effect of viscin was more pronounced in Molt4 and U937 cells (IC50 (concentration that inhibited cell proliferation by 50%): 118 +/- 24 and 138 +/- 24 microg mL(-1)) than in K562 cells (IC50: 252 +/- 37 microg mL(-1)). Oleanolic acid was the least effective in all cell lines (7.5-45.5% inhibition at 10 microg mL(-1)) and ursolic acid the most active in Molt4 and U937 cells (81.8 and 97.8% inhibition, respectively, at 5 microg mL(-1)). A dose-dependent loss of membrane phospholipid asymmetry associated with apoptosis was induced in all cell lines as shown in flow cytometry by the externalization of phosphatidylserine and morphological changes in cell size and granularity. There were differences in individual cell lines' response towards the apoptosis-inducing effect of viscin, betulinic acid, oleanolic acid and ursolic acid. The triterpenoids beta-amyrin, beta-amyrinacetate, lupeol, lupeolacetate, beta-sitosterol and stigmasterol, and the fatty acids oleic acid, linoleic acid, palmitic acid and stearic acid were also present in the lipophilic extract.

Antineoplastic Agents, Phytogenic↗

Influence of proportional assist ventilation on diaphragmatic activity in normal subjects.

In six awake healthy adults we studied the physiological effects of mechanical unloading of the respiratory muscles during increased ventilatory demand. We were interested in whether respiratory muscle activity is down regulated and if this is mainly a consequence of chemical factors, i.e. CO2-reduction, or non-chemical neuromuscular inhibition. With 33 mmHg inspiratory CO2 we induced modest hyperpnea of 24.4 +/- 3.9 L/min. Proportional assist ventilation (PAV) was applied with flow-related assist of 2.5 cm H2O/L/s and volume-related assist of 6 cm H2O/L. Respiratory muscle activity was measured by transdiaphragmatic pressure. Unloading caused a 57 percent reduction of the inspiratory transdiaphragmatic pressure-time product (p<0.05), while tidal volume, breathing frequency, and breathing pattern did not significantly change. These observations suggest that during increased ventilatory requirements, PAV results in down regulation of respiratory muscle activity and that this effect is mainly a consequence of neuromechanical inhibition.

Adult↗

Prognosis factors in incisional hernia surgery: 25 years of experience.

BACKGROUND: Incisional hernia underwent a change from conventional techniques to mesh implantation. The relevance of different factors, like operative technique, mesh material, and patient-related parameters concerning the outcome following mesh repair, are still under debate. METHODS: In a comparative retrospective study of 421 incisional hernia operations on 348 patients, we investigated 241 Mayo procedures and 180 mesh repairs over a 25-year period. In addition to the quality of life following mesh implantation, the prognostic relevance of demographic, preoperative and intraoperative parameters, surgical technique, mesh material, and the surgeon's experience were analysed, both in a univariate and multivariate manner. RESULTS: With a mean follow-up of 9.7+/-8.8 years, the total recurrence rate following Mayo overlap was 37%, in contrast to 15% after mesh implantation (P=0.001). Mesh size was the only significant prognostic factor concerning quality of life following mesh implantation, and 86% of the patients with mesh repair were satisfied. The complication rate was determined significantly by patients' risk factors, size of hernia, operative technique, and the surgeon's experience, whereas the rate of recurrences was significantly influenced by the parameters obesity (BMI>25), size of hernia, and surgical experience. The recurrence rate decreased significantly with surgeon's experience-a minimum of 16 mesh repairs led to a recurrence rate of less than 10%. CONCLUSIONS: Only the mesh repair revealed acceptable recurrence rates with high patient comfort. From a surgical point of view, the most important prognostic factor following mesh repair is the surgeon's experience.

Female↗

Impact of vasoactive intestinal polypeptide and gastrin-releasing peptide on small bowel microcirculation and mucosal injury after hepatic ischemia/reperfusion in rats.

BACKGROUND AND AIMS: Alterations in microvascular perfusion of the intestine after hepatic ischemia/reperfusion have been suggested as an important cause of postoperative septic complications. We therefore investigated small bowel microcirculation and mucosal injury after liver ischemia/reperfusion in a rat model. Furthermore, we analyzed the effects of the regulatory peptides vasoactive intestinal polypeptide and gastrin-releasing peptide for their splanchnic vasoactivity. METHODS: Hepatic ischemia was induced by clamping of the left hepatic artery and vein for 40 min, followed by 60 min of reperfusion. The control group was treated similarly, but without clamping of the liver vessels. Ten minutes after clamping of the hepatic vessels, vasoactive intestinal polypeptide or gastrin-releasing peptide, respectively, were continuously infused intravenously in the experimental groups. Small bowel microcirculation and mucosal injury were assessed using intravital microscopy and the Chiu-score, respectively. RESULTS: The functional capillary density of the small intestine following ischemia and reperfusion of the left hepatic lobe significantly decreased compared to normal controls in both the mucosa and the smooth intestinal muscle. Red blood cell velocity decreased, whereas leukocyte-endothelium adherence, stasis index and the mucosal injury score increased. Administration of vasoactive intestinal polypeptide resulted in an increase of functional capillary density in the mucosa and of the red blood cell velocity and a decrease in the stasis index. The mucosal injury score was significantly higher in reperfused animals without treatment. The application of gastrin-releasing peptide resulted in an isolated increase of the red blood cell velocity. Leukocyte adherences could not be altered by the regulatory peptides. CONCLUSION: We conclude that hepatic ischemia/reperfusion injury leads to significant alterations of small bowel microcirculation and mucosal injury. Vasoactive intestinal polypeptide and gastrin-releasing peptide attenuate the damage in a different manner.

Animals↗

Microcirculation and excretory function of the liver under conditions of carbon dioxide pneumoperitoneum.

BACKGROUND: To date, the effects of increased abdominal pressure, as given during carbon dioxide (CO(2)) pneumoperitoneum, on hepatic microcirculation and biliary excretion are unknown. METHODS: Using a custom-made peritoneal cavity chamber, we performed intravital microscopy of the left liver lobe under conditions of CO(2) pneumoperitoneum in a rat model. In addition, biliary excretion was assessed. RESULTS: The establishment of a CO(2) pneumoperitoneum of 4 or 8 mmHg resulted in sinusoidal perfusion failure that was more pronounced in the periportal regions than in the midzonal and pericentral regions of the liver acinus. Biliary excretion was considerably reduced at an intraabdominal pressure of 8 mmHg. Leukocyte-endothelial cell interactions increased significantly in both hepatic sinusoids and postsinusoidal venules. CONCLUSION: Alterations in hepatic microcirculation and liver function must be taken into consideration in any kind of laparoscopic surgery and may be of particular clinical relevance in patients with liver pathology.

Animals↗

[Visualization of symmetric striopallidodentate calcinosis by using high-resolution susceptibility-weighted MR imaging. An account of the impact of different diagnostic methods of M. Fahr].

Bilateral striopallidodentate calcinosis, also known as Fahr's disease, is characterized by symmetric calcifications of the basal ganglia, thalami, dentate nuclei of the cerebellum and white matter of the cerebral hemispheres. Besides the common idiopathic etiology of bilateral intracerebral calcinosis, alterations of calcium metabolism are present in rare cases, which are especially caused by hormonal dysfunction of the parathyroids. Advanced imaging techniques, such as CT and MRI, demonstrate increasing relevance regarding diagnosis of bilateral striopallidodentate calcinosis. Intracranial calcifications are routinely observed with high sensitivity by CT. On MR images calcifications exhibit different signal intensities, which depend on the stage of the disease, differences in calcium metabolism and the compound of these calcifications. Application of a new high-resolution, susceptibility-weighted MR sequence allows detailed visualization of the intracerebral calcifications in Fahr's disease. Further diagnostic methods and important aspects regarding clinical manifestation of bilateral striopallidodentate calcinosis are also discussed.

Basal Ganglia Diseases↗

Effect of peracetic acid and aldehyde disinfectants on biofilm.

The effects of two aldehyde (Cidex, Endosporine) and four peracetic acid (PAA) (Nu Cidex, Anioxyde 1000, Hydraseptic, Peralkan) disinfectants on an Escherichia coli biofilm model were studied. The biofilm was prepared in glass tubes, and evaluated indirectly using a colourimetric method. The ability of the disinfectants to fix or remove the biofilm from tubes was determined by their detergent activity (DA). The two aldehyde derivatives and two of the PAA (Nu Cidex, Anioxyde 1000) agents fixed the biofilm. However, the effects of Hydraseptic and Peralkan were equivalent to the control (sterile water). Regardless of their disinfectant activity, PAA agents display different DAs that could be used to select the weakest biofilm-fixing agents. Users should be concerned about the efficiency of the cleaning stage of medical devices, and when choosing a PAA product, non-fixing ability should be considered in addition to antimicrobial activity.

Biofilms↗

Acute impairment of hepatic microcirculation and recruitment of nonparenchymal cells by intrasplenic hepatocyte transplantation.

BACKGROUND/PURPOSE: Over the last 20 years, hepatocyte transplantation (HcTx) has advanced from the experimental to the clinical stage. To date, HcTx has been performed in 30 patients in the United States. Regardless whether hepatocytes are transplanted into the spleen and migrate to the liver or are injected directly into the portal vein, transplanted liver cells will, to some extent, congest the recipient liver microcirculation. The potential negative consequences of intrasplenic HcTx were the subject of this study. METHODS: By using intravital microscopy, the authors investigated whether intrasplenic HcTx of 20 x 10(6) allogenic hepatocytes would influence liver perfusion, excretory liver function, and nonparenchymal cells (Kupffer and Ito cells) in vivo. RESULTS: The sinusoidal perfusion rate declined significantly from 94% (control) to 84% on day 1 and 76% on day 7. Bile acid excretion decreased in a similar fashion from 0.924 mg/h (control) to 0.669 mg/h on day 7. The authors observed a significant increase of Ito cells from 81.1 cells per microscopic field (control) to 97.1 (day 1) and an increase of Kupffer cells (KC; 6.1 cells per microscopic field on day 1 v 3.8 on control). CONCLUSIONS: This study shows an acute impairment of hepatic microcirculation and hepatucellular function along with an recruitment and activation of nonparenchymal cells in the early posttransplantation period after intrasplenic HcTx. Kupffer cell recruitment indicates an activation of local host defense, and Ito cell activation implies the initiation of liver repair mechanisms owing to ischemia-related cell damage.

Animals↗

[Tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for sonographically guided vacuum-assisted biopsy of mammographically occult breast tumors].

PURPOSE: To assess the guidance of tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for vacuum assisted biopsies of suspicious breast lesions compared to fundamental B-mode ultrasound-guided biopsies. MATERIAL AND METHODS: In 550 patients, ultrasound examinations of the breast were performed prospectively using fundamental B-scan, THI, and CHI. Focal lesions were documented in comparable projections for all three ultrasound modes. As contrast agent, a dose of 0.5 milliliters of Perflutren Protein-Type A microspheres ( Optison) was injected. An ultrasound-guided biopsy was performed in 38 focal lesions. Three radiologists experienced in breast imaging retrospectively assessed the lesions on the ultrasound images. RESULTS: Thirty-eight suspicious focal lesions [size 4 - 15 mm; median 8 mm] were detected by ultrasound. Of these, 29 were detected by fundamental B-scan images, 34 by THI, and 38 by CHI. Ultrasound-guided biopsy was performed on all of these lesions. No complications related to the biopsy were observed. In 25/38 cases, invasive carcinomas were found; in 6/38 ductal carcinomas in situ; in 3 cases metastases of already known invasive ductal carcinomas; and in 4 cases fibroadenomas. The size of the lesion was best identified using THI, smaller lesions (< 10 mm) using CHI. CONCLUSION: THI and CHI can help to detect focal lesions in dense breasts. Both modes can make it easier to perform ultrasound-guided biopsies of focal breast lesions.

Biopsy, Needle↗

[3D-Visualisation of the middle ear by computer-assisted post-processing of helical multi-slice CT data].

Post-processing of CT-data allows non-invasive 3D-Visualisation of the middle ear for diagnosis and surgical planning. In this study different post-processing techniques and the clinical application of a 3D-postprocessing algorithm in a large number of patients are presented. 20 normal patients, 6 dissected temporal bones and 213 patients with suspected middle ear pathology were examined using a low-dosage Multi-Slice CT protocol. Virtual endoscopic views of the middle ear and 3D-images of the ossicles were generated using a standardised algorithm. Evaluation of the image quality was performed. The virtual views of the dissected temporal bones were compared to real views. In 32 patients high-quality 3D-models of the individual anatomical structures were generated and displayed using different visualisation techniques. The standardised and evaluated method enabled visualisation of the normal middle ear anatomy. Assessment of different pathologies, especially malformation, trauma, implants and postoperative alterations, was facilitated. The high-quality 3D-models allowed precise imaging of the anatomical structures. 3D-Visualisation of the middle ear using CT-data is beneficial for radiological diagnosis and surgical planning in cases of complex middle ear pathology as a complementary examination technique.

Adolescent↗

Dissection of the brain supplying arteries over the life span.

Cervical artery dissection (CAD) is being increasingly diagnosed due to improved neuroimaging methods. The mean age of patients with CAD is about 40 years, with a peak between 40 and 45 years of age. Proven data on the incidence of CAD in older patients are missing. Therefore, whether CAD should also be considered as a probable cause of cerebral ischemic events in the elderly was investigated. All consecutive patients referred to our clinic with a diagnosis of cerebral ischemia from January 1999 until June 2000 were thoroughly assessed for the presence of CAD. In addition, the records of all stroke patients treated in our department from January 1995 to December 1998 were analysed retrospectively for a diagnosis of CAD. A total of 34 patients (11 women) had suffered from internal carotid (n = 29) or vertebral artery (n = 5) dissection. Their mean (SD) age was 50.3 (14.6) years, with 32.4% being older than 60 years. Clinical presentation of CAD did not differ depending on the patients' age. The results show that CAD is a possible cause of cerebral ischemia in the elderly and thus has also to be considered in the diagnostic investigation in this patient group.

Adult↗