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Biomedical subjects

N Senninger

Publications and source records attributed to N Senninger.

At least 19 recordsLinked to original sources

[Prognosis of malignant melanoma following dissection regional lymph node metastases].

BACKGROUND: Malignant melanomas usually metastasize in the regional lymph nodes. This generally leads to a worsening of prognosis. Survival probability after extirpation of the tumorous regions is conditioned by various factors. Until now, the basis for differentiated therapy has been the precise understanding of the TNM classification. Clinical parameters are also relevant to therapy and of decisive importance to the further course of disease. QUESTION: Which clinical parameters are important to the prognosis of patients with regional melanoma and lymph node disease? PATIENTS AND METHODS: This study is a retrospective analysis of patients at the Clinic and Polyclinic of General Surgery of the University Hospital in Münster,Germany, together with a review of the literature. Included were 137 patients who received curative resection of lymph node metastases from malignant melanomas between 1974 and 1996. From the literature, 6,694 cases were found which allowed the establishment of 13 different prognosis parameters following lymph node metastasis resection These parameters were compared with our own results concerning established, relevant parameters. RESULTS: The cumulative 5-year survival rate for patients studied was 50.7%. The 5-year survival rates relating to characteristics varied between 12.9% and 80.0%. Of the 13 variables from the literature relevant to prognosis that were included in this analysis, four were found to be significant: Breslow penetration depth, standardized age and age at primary tumor diagnosis, recurrence, and location of the primary tumor. Considering these significant characteristics, one can arrive at a detailed prognostic classification of patient and history. This is indispensable for correctly tailoring therapy to disease stage.

Adult↗

[Rectal carcinoma in a patient with familial adenomatous polyposis coli after colectomy with ileorectal anastomosis and consecutive chemoprevention with sulindac suppositories].

Surgery is the definitive treatment in familial adenomatous polyposis coli (FAP). Proctocolectomy with ileal pouch anal anastomosis is recommended for the majority of FAP patients. Only in patients with attenuated FAP, is a colectomy with ileorectal anastomosis (IRA) accepted, although the risk for rectum carcinoma remains increased. Sulindac, a chemoprophylactic agent, regresses colorectal adenomas in patients with FAP. Under systemic Sulindac-therapy, three carcinomas in the rectum after colectomy with IRA have been described. We report the first known case of rectum carcinoma in a patient with FAP, 51 months after IRA and local Sulindac therapy.

Adenocarcinoma↗

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↗

ICAM-1 and VCAM-1 antisense oligonucleotides attenuate in vivo leucocyte adherence and inflammation in rat inflammatory bowel disease.

BACKGROUND: Recruitment of circulating cells to the inflamed intestine is modulated by adhesion molecules expressed on the surface of both leucocytes and endothelial cells. AIMS: The objective of this study was to test whether 2'-O-methoxyethyl chimeric antisense oligonucleotides directed against endothelial intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) can downregulate leucocyte-endothelial interactions and thereby attenuate inflammation in rat experimental ileitis. METHODS: Indomethacin (7.5 mg/kg ) was injected subcutaneously into Sprague-Dawley rats 48 and 24 hours prior to intravital microscopy. Animals were treated with either ICAM-1 (ISIS 17470), VCAM-1 (ISIS 18155), or scrambled control antisense oligonucleotides administered subcutaneously or intravenously in parallel with indomethacin. Leucocyte trafficking was observed in ileal submucosal collecting venules. Macroscopic and histological grades of inflammation were measured 48 hours after the first indomethacin application. ICAM-1 and VCAM-1 expression in ileal submucosal venules was detected by immunohistochemistry. RESULTS: Intravenous administration of ICAM-1 oligonucleotides 2 mg/kg (rolling leucocytes 5.7 (2.4)/0.01 mm(2) endothelial surface, adherent leucocytes 0.8 (1.1)) and VCAM-1 oligonucleotides 8 mg/kg (9.2 (4.4), 0.6 (0.8)) significantly reduced leucocyte adhesion compared with diseased controls (27.8 (5.3), 14 (4.4)) in a dose dependent manner whereas subcutaneous treatment did not. Correspondingly, macroscopic and histological inflammation was significantly decreased. ICAM-1 oligonucleotides markedly reduced endothelial ICAM-1 expression while VCAM-1 oligonucleotides clearly diminished endothelial VCAM-1 expression. CONCLUSIONS: Both ICAM-1 and VCAM-1 2'-O-methoxyethyl chimeric antisense oligonucleotides attenuate rat ileitis by downregulation of leucocyte adherence and thus are potential candidates for anti-inflammatory treatment in inflammatory bowel disease.

Animals↗

An XML-based system for the flexible classification and retrieval of clinical practice guidelines.

Beneficial effects of clinical practice guidelines (CPGs) have not yet reached expectations due to limited routine adoption. Electronic distribution and reminder systems have the potential to overcome implementation barriers. Existing electronic CPG repositories like the National Guideline Clearinghouse (NGC) provide individual access but lack standardized computer-readable interfaces necessary for automated guideline retrieval. The aim of this paper was to facilitate automated context-based selection and presentation of CPGs. Using attributes from the NGC classification scheme, an XML-based metadata repository was successfully implemented, providing document storage, classification and retrieval functionality. Semi-automated extraction of attributes was implemented for the import of XML guideline documents using XPath. A hospital information system interface was exemplarily implemented for diagnosis-based guideline invocation. Limitations of the implemented system are discussed and possible future work is outlined. Integration of standardized computer-readable search interfaces into existing CPG repositories is proposed.

Information Systems↗

[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↗

Protective role of an endothelin-converting enzyme inhibitor (FR901533) in hepatic ischemia/reperfusion injury.

INTRODUCTION: There is evidence that endothelin (ET) contributes to disturbances of the hepatic microcirculation after warm ischemia/reperfusion (I/R) by causing vasoconstriction and by enhancing leukocyte endothelium interactions. The aim of this study was to investigate a possible protective role of the endothelin converting enzyme (ECE) inhibitor FR901533 in this setting. METHODS: In an in vivo model (42 Wistar rats), hepatic ischemia was induced for 30 min by Pringle's maneuver. Sham operated (I), untreated ischemic (II), and treatment (III) groups with FR901533 (1 mg/kg bw iv) were investigated. The effect of FR901533 in I/R was assessed by in vivo microscopy (30-90 min after reperfusion), measurement of local tissue pO2 (30 and 60 min after reperfusion), and determination of AST/ALT levels (2 h, 6 h, and 2, 6, and 14 days after reperfusion). RESULTS: In the untreated ischemic group (II) sinusoidal constriction to 76.3 +/- 4.2% of basic diameters was observed, leading to significant decreases in perfusion rate (82.3 +/- 3.6% of sham group) and in liver tissue pO(2) (43.5 +/- 3.2% of sham group) (P < 0.05). In addition, we found an increased percentage of stagnant leukocytes in sinusoids (138.3 +/- 9.8) and sticking leukocytes in postsinusoidal venules (155.2 +/- 3.3% of sham group) (P < 0.05). Hepatocellular damage (AST/ALT increase to 430.6 +/- 47.7 U/L/200.2 +/- 23.8 U/L, pre: 27.4 +/- 2.7 U/L/28.1 +/- 2.7 U/L) was detected 6 h after reperfusion (P < 0.05). Administration of the ECE inhibitor before ischemia significantly reduced I/R injury. Sinusoidal diameters were maintained (102.2 +/- 1.7%), while perfusion rate (93.1 +/- 1.8%) and tissue pO2 (105.3 +/- 2.7%) increased significantly (P < 0.05). Hepatocellular damage was decreased (AST/ALT levels after 6 h of reperfusion: 166.6 +/- 26.3 U/L/132.4 +/- 22.5 U/L, P < 0.05) and leukocyte sticking and rolling were significantly reduced (P < 0.05). CONCLUSION: Our results provide evidence that the new therapeutic approach with an ECE inhibitor is effective in reducing hepatic I/R injury.

Angiotensin-Converting Enzyme Inhibitors↗

[Management of biliary complications after orthotopic liver transplantation].

In this retrospective analysis we report our results after liver transplantation regarding biliary complications (bc) and the effectiveness of endoscopic therapy. In the last 4 1/2 years we found 13 biliary leaks (7 in combination with a stenosis, 3 at the T tube insertion site), 9 biliary stenosis, 3 papillary stenosis, 2 biliary aggregates and one case of ischemic type biliary lesion, resulting in an overall complication rate of 30%. 10 (36%) "bc" could be treated successfully endoscopically, whereas 8 (32%) patients are still under observation with an endoprosthesis in the biliary tract. 10 endoscopic trials were without the desired effect, requiring a surgical reintervention. In 4 cases a thrombosis of the hepatic artery was responsible for the unwanted course.

Adolescent↗

Increased expression of metallothionein in inflammatory bowel disease.

OBJECTIVE: Metallothioneins (MT) are cytoprotective against the damaging effects of oxygen-derived free radicals. Therefore MT may be involved in defence mechanisms to counter Crohn's disease (CD) and ulcerative colitis (UC). MATERIALS: 107 routinely processed tissue samples from 22 patients with CD and 48 patients with UC were tested with the monoclonal anti-MT antibody E9. METHODS: Immunohistochemistry was used to assess MT staining in a semiquantitative manner. Chi-square test was used for statistical analysis. RESULTS: MT overexpression was found in the fibroblasts of all ulcerative and/or fissural lesions in UC and CD. MT overexpression in intestinal epithelial cells of 40% of UC and CD lesions correlated significantly with the grade of inflammation. CONCLUSIONS: MT-immunoreactivity in fibroblasts supports a protective role for MT in inflammatory bowel disease. It remains unclear whether MT overexpression in epithelial cells is also important in this protection.

Humans↗

[Long-term outcomes in oncological surgery: influence of individual prognostic factors].

In addition to tumor stage there are factors influencing the long-term outcome of an oncological operation. Age per se is not a risk factor; however, comorbidity coinciding with increased age definitely must be regarded as a decisive risk factor. The best prediction of the operative risk is achieved by the ASA classification. Frequently used scores such as ECOG and the Karnofsky index are of little help. Since most elderly patients are excluded from prospective, controlled and randomized studies, only individualized assessments concerning the risk profile are useful at present. However, the overall operative competence of a center is most relevant in the treatment of the so-called "risk patient".

Adult↗

[Role of FDG-PET in oncological surgery].

Fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) allows in vivo analysis of tissue metabolic activity. Based on the observation that most malignant tumors display a higher metabolic activity than benign tissues, [18F]FDG-PET offers an interesting option for the diagnosis of primary and recurrent malignant tumors. For the oncological surgeon [18F]FDG-PET is particularly helpful for the diagnosis of tumors of the pancreas, colorectum, lung and esophagus. This short review describes the biological basis of [18F]FDG-PET and gives a critical discussion of its role in oncological surgery.

Blood Glucose↗

[How are beginning students in surgery selected? Results of a survey of German consultant surgeons].

AIM: After finishing medical school it is getting more and more difficult for medical students to get one of the rare positions in a surgical training program. Only a good career plan and an intelligent strategy for the first steps in surgical life seem to be an advantage for that competition. On the other hand the selection of basic surgical trainees only based on the curriculum vitae and brief interviews may not be satisfying. The aim of this investigation was to answer the following questions: 1. How do consultant surgeons select their basic trainees? 2. How important is the applicant's record and the interview? 3. Which educational and personal criteria are important for the selection? 4. How can medical students improve their chance of getting a position in a surgical training program. METHODS: Using an anonymous and standardized questionnaire 39 chiefs of university departments of surgery and 44 consultant surgeons each from general and local hospitals were interviewed concerning their selection process and criteria required for application in their training program. The candidates were chosen from an official address list (Deutsche Chirurgie 98, Berufsverband der Deutschen Chirurgen). The questionnaire was sent to the candidates by official postal service together with a prepaid return envelope. RESULTS: Twenty-eight chiefs of university departments of surgery (71.8%) and 29 (65.9%) and 20 (45.5%) of the interviewed consultant surgeons in general and local hospitals responded to the 89-item questionnaire. It turned out that the majority of applications were send to the clinics at the applicant's initiation. Personal relationships or networks are important. Position advertisements are not important. 85.1% of the responders are satisfied with their procedure of selection, nevertheless, 43.4% are interested in recruiting markets. In detail, chiefs of surgical departments in university clinics get a mean of 12.3 (5-50) applications for basic surgical training per month, consultant surgeons in general hospitals 6.5 (4-20), those in local hospitals 5.6 (2-10). The completion and the contents of the doctor's thesis, former research efforts, foreign languages, computer knowledge and other qualifications are the most important criteria in the selection process. Reliability, loyalty, physical and psychological stability, organising and planning ability, stamina, sociability and independence are the most valued personal skills. CONCLUSIONS: Despite the satisfaction with the established common selection process, the high rate of participation in our study shows how important this subject is ranked by leading surgeons. It turned out that besides professional qualification, personal skills are a major criterion in the selection of basic surgical trainees.

Clinical Competence↗

The anastomosis between renal polar arteries and arteria epigastrica inferior in kidney transplantation: an option to decrease the risk of ureter necrosis?

Ureteral necrosis after renal transplantation is often the result of impaired perfusion due to loss of donor polar arteries. A way of preserving polar arteries is their anastomosis with the A. epigastrica inferior. In three cases (aged 49-, 58-, and 63 years), 9.3 % of 33 living donors, we detected donor polar arteries on both sides, and anastomosed the polar artery to the A. epigastrica inferior with microsurgical methods. Intraoperatively, the flow was measured by flowmeter, in the postoperative course duplexsonography and MR-angiography was performed. In all three cases we noted a bluish, ischemic parenchym mass of 10-25 % of the kidney and ureter. It recovered immediately, however, after the polar artery had been reconstructed. Intraoperative measurement showed a high flow on the polar- and the main renal artery. Duplexsonography and MR-angiography documented a good flow on the A. epigastrica anastomosis. There have been no signs of ureteral problems at all. After a mean follow-up time of 26 months, the mean creatinine level is 1.46 mg/ml. Ureteral necrosis after kidney transplantation is mostly the result of a lack of perfusion of the polar arteries of the lower kidney pole. If arteriosclerotic lesions inhibit an anastomosis with the renal artery, the anastomosis with the A. epigastrica inferior seems to be a useful alternative.

Anastomosis, Surgical↗

Outcome of surgical intervention for rectoneovaginal fistulas in Mayer-Rokitansky-Kuester-Hauser syndrome.

Creation of a neovagina to treat vaginal atresia or aplasia in Mayer-Rokitansky-Kuester-Hauser syndrome must always be followed by long-term application of dilators to avoid shrinkage. However, rectoneovaginal fistulas are caused by chronic alteration and consecutive necrosis of the posterior neovaginal wall. We evaluated retrospectively the postoperative outcome of rectal wall and neovaginal reconstruction using a standardized surgical technique in an exclusive collection of women. Eight women with a mean age of 28 years (range 22-31 years) were treated for rectoneovaginal fistulas in our clinic. Preoperatively, proctoscopy, sphincter manometry, endoluminal rectal ultrasonography, and colonoscopy were performed; and regular postoperative follow-up by digital examination and rectoscopy were obligate. The standard surgical procedure via a perineal approach included fistulectomy and closure of the mucosa and rectal wall followed by a levatorplasty. All but one woman had a temporary colostomy. After 2 weeks the patients were allowed to wear vaginal dilators of a smaller size. Within the mean follow-up period of 20 months, reintervention was necessary twice because of late fistula relapse detected by proctoscopy, barium enema, and subjective symptoms. Morbidity was 25% (n = 2) due to secondary superficial wound healing or urinary tract infection. The average time of the hospital stay was 13 days (10-14 days). One patient complained of vaginal shrinkage and underwent local estrogen therapy with a good functional result 3 months later. Proper fistulectomy and surgical reconstruction with interpositioning of well perfused muscle layers achieved good functional outcome with an acceptable number of minor morbidities. Local estrogen treatment is helpful for avoiding scarification and decreasing the neovaginal size.

Adult↗

Acetyl-11-keto-beta-boswellic acid, a constituent of a herbal medicine from Boswellia serrata resin, attenuates experimental ileitis.

The gum resin extract from Boswellia serrata (H15), an herbal product, was recently shown to have positive therapeutic effects in inflammatory bowel disease (IBD). However, the mechanisms and constituents responsible for these effects are poorly understood. This study examined the effect of the Boswellia extract and its single constituent acetyl-11-keto-beta-boswellic acid (AKBA) on leukocyte-endothelial cell interactions in an experimental model of IBD. Ileitis was induced by two subcutaneous injections of indomethacin (7.5 mg/kg) in Sprague-Dawley rats 24 h apart. Rats also received oral treatment with the Boswellia extract (H15) or AKBA at two different doses (low and high) equivalent to recommendations in human disease over 2 days. Controls received only the carriers NaHCO3 (subcutaneously) and tylose (orally). Effects of treatment were assessed by intravital microscopy in ileal submucosal venules for changes in the number of rolling and adherent leukocytes and by macroscopic and histological scoring. Increased leukocyte-endothelial cell adhesive interactions and severe tissue injury accompanied indomethacin-induced ileitis. Treatment with the Boswellia extract or AKBA resulted in a dose-dependent decrease in rolling (up to 90%) and adherent (up to 98%) leukocytes. High-dose Boswellia extract as well as both low- and high-dose AKBA significantly attenuated tissue injury scores. Oral therapy with the Boswellia extract or AKBA significantly reduces macroscopic and microcirculatory inflammatory features normally associated with indomethacin administration, indicating that the anti-inflammatory actions of the Boswellia extract in IBD may be due in part to boswellic acids such as AKBA.

Animals↗