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Biomedical subjects

M Koch

Publications and source records attributed to M Koch.

At least 19 recordsLinked to original sources
PubMed2007

[Influence of thyroid cartilage ossification in laryngeal ultrasound].

BACKGROUND: Topological features of the larynx and hypopharynx may be depicted during sonographic examination of the neck, although ultrasound is seen of minor diagnostic importance. The varying extend of thyroid cartilage ossification appears to be the major limiting factor. We intended to assess the sonographic accessability of laryngeal structures with high end resolution ultrasound devices. METHODS AND PATIENTS: We examined 101 patients endoscopically and by ultrasound. Normal laryngeal findings and pathologies were examined and analysed considering limitations by thyroid cartilage ossification. RESULTS: Despite varying grades of ossification, the majority of laryngeal structures were clearly displayed by ultrasound. Ossification was increasing in the elderly. In 16 cases (16 %) ossification prevented a successful evaluation. In 9 cases of malignant tumor and one laryngocele sonographic assessment was able to contribute additional diagnostic information. CONCLUSIONS: Ultrasound of the larynx requires methodical experience of the operator but is capable to depict relevant anatomic structures, even with presence of thyroid cartilage ossification, thus being able to increase diagnostic impact and may save additional imaging modalities.

Adult↗
PubMed2006

The mitochondrial genomes of Campodea fragilis and Campodea lubbocki (Hexapoda: Diplura): High genetic divergence in a morphologically uniform taxon.

Complete mitochondrial genome sequences are presented from two dipluran hexapods (i.e., a group of "primarily wingless insects") of the genus Campodea and compared to those of other arthropods. Their gene order is the same as in most other hexapods and crustaceans. Structural changes have occurred in tRNA-C, tRNA-R, tRNA-S1 and tRNA-S2 as well as in both ribosomal RNAs. These mtDNAs have striking biases in nucleotide and amino acid composition. Although the two Campodea species are morphologically highly similar, their genetic divergence is larger than expected, suggesting a long evolutionary history, perhaps under stable ecological conditions.

Animals↗
PubMed2006

[Long-term experiences in the therapy of esthesioneuroblastoma].

BACKGROUND: Esthesioneuroblastoma is a rare and clinically variable tumor of nasal sinus and skull base and challenging for modern multidisciplinary therapy. There are no generally known prognostic factors or generally accepted standard therapy regimens. PATIENTS AND METHODS: Between 1975 and 2001 26 patients were treated after the diagnosis of esthesioneuroblastoma was established. The cases were evaluated retrospectively. According to the classification of Kadish 1 patient (4 %) had stage A, 16 patients (53 %) stage B and 11 cases (43 %) had stage C tumors. Hyams grading could be obtained in 22 cases (81 %). Tumors were in 12 patients (52 %) graded I or II and in 10 cases tumors had grade III or IV (48 %). Operative therapy was performed in 23 patients (88.5 %), being in 5 patients a single mode therapy. In 18 cases combined therapy was performed (surgery and radiotherapy or radiotherapy and chemotherapy). RESULTS: Actuarial survival was 61.5 % (16/26). Disease specific 10- and 15-year-survival according to the estimation of Kaplan-Meier was 76.2 %. Patients with small tumors (Kadish A/B) had a 15-year-survival of 86.7 % compared to 63.6 % in cases with advanced tumors (Kadish C). In 7 cases (26.9 %) recurrences developed. Salvage therapy was performed in 5 cases (71.4 %) with a success rate and a 15-year survival each of 60 %. CONCLUSIONS: Therapy of esthesioneuroblastoma is challenging because of rarity and biologic variability of the tumor and and because of lack of a standard therapy. An interdisciplinary multimodal therapeutic approach is necessary especially in case of advanced tumors with promising results. Histopathological grading according to Hyams and tumor stage are important factors for survival and prognosis. Although recurrence can occur with high frequency even after prolonged time interval, long time survival can be improved after aggressive salvage therapy. Therefore longterm follow up is mandatory.

Adolescent↗
PubMed2006

[Measurement uncertainty in drinking water analysis. Conclusions from interlaboratory tests].

The problems of measurement uncertainty, its estimation and the connection with the requirements of the drinking water legislation on the analytical methods are described. The difficulties with these requirements are shown. On the basis of numerous interlaboratory test data, the concentration dependences of the reproducibility standard deviation for 75 drinking water parameters were calculated using a variance function described in DIN 38402-45. From this function means of standard deviation at the legal limit could be calculated with high confidence. These values are compared with the requirements of the legislation. These data can be used on the one hand for the estimation of uncertainties in the laboratories or the plausibility check of uncertainties already estimated. On the other hand these data can be helpful for deriving an official interpretation or creating new requirements for the drinking water legislation.

European Union↗
PubMed2006

[Online continuing medical education based on national disease management guidelines. The e-learning platform leitlinien-wissen.de].

Effective translation of relevant knowledge into clinical practice is essential for modern health care systems. National Disease Management Guidelines (NDMG) are considered relevant instruments to support this transfer. To implement NDMG Internet-based continuing medical education (CME), modules and online case-based learning objects were designed and published. To ensure high quality the contents are based on NDMG and subjected to multi-step review processes. Presentation on the web was realized through a modified content management system. To obtain a CME certificate, completing an online questionnaire using a four-point Likert scale was mandatory. Between June 2003 and April 2005, 3,105 physicians were registered and used the platform: 95% of the physicians expressed positive feedback in the evaluation questionnaire, and 35% actually used the corresponding NDMG in practice. This prompted the development of interactive medical case-based learning objects as a second learning pathway. An Internet platform for CME including case-based learning objects can be a helpful tool to assure the provision of scientific knowledge for patient care.

Certification↗
PubMed2006

[Neuroendocrine tumors of the larynx].

BACKGROUND: The location of neuroendocrine tumors in the larynx (NETL) is atypical and relatively rare. It has become possible to determine increasing numbers of these tumors in recent years owing to improvements in immunohistological methods. Extensive recommendations were made with regard to diagnostics and treatment by the "European Neuroendocrine Tumor Group" in 2004. These recommendations relate mainly to the very much more frequent gastroenteropancreatic neuroendocrine tumors and cannot be applied directly to NET of the larynx. This is why precise scientific investigations of NETL and publications of new cases are important. METHODS: Retrospective review of all laryngeal malignancies treated from 1994 to 2004 revealed a NETL in three of about 1000 patients. These patients were evaluated with regard to clinical symptoms, tumor locations, immunohistological findings and the clinical courses. RESULTS: Evaluation of the patients (incidence 0.23%: average age 58 years: female to male 1:2) revealed a poorly differentiated neuroendocrine carcinoma in two patients and a moderately differentiated neuroendocrine carcinoma in one patient. After surgical treatment and radiochemotherapy, the patients with a poorly differentiated carcinoma survived for seven and 17 months respectively and the patient with a moderately differentiated carcinoma survived for 30 months. The patients investigated showed findings consistent with those of previously published cases with regard to the parameters investigated. CONCLUSIONS: NETL require more extensive staging investigations and a specific treatment adapted to the subtyping. Treatment at specialized centers with publication of individual cases is desirable to extend and deepen knowledge.

Diagnosis, Differential↗
PubMed2006

Laparoscopic surgery for colorectal cancer.

Traditionally open surgical resection has been recommended for colorectal tumours, but recently, laparoscopic surgery has gained popularity. This review summarizes the published data on laparoscopic colorectal cancer surgery with emphasis on recently published trials. For colon cancer laparoscopic resection appears to be associated with the same outcome as open surgery. However, whilst short-term outcome was better in the laparoscopic group in most of the randomized trials, when comparing laparoscopic with fast-track open surgery, no differences could be demonstrated in a randomized control trial. For rectal cancer the data are less clear. It seems that it may be feasible to resect at least small rectal cancers laparoscopically. Clearly the role of the laparoscopic technique needs to be better defined in rectal cancer. It has been well documented that short- and long-term outcome of colorectal cancer surgery depends on the quality and experience of the team treating the patient. Therefore, the major future challenge in laparoscopic colorectal cancer surgery will be to provide and structure adequate training and introduce quality control measures.

Colectomy↗
PubMed2006

C4d in acute rejection after liver transplantation--a valuable tool in differential diagnosis to hepatitis C recurrence.

Hepatitis C is the most common indication for liver transplantation. Recurrence of HCV is universal leading to graft failure in up to 40% of all patients. The differentiation between acute rejection and recurrent hepatitis C is crucial as rejection treatments are likely to aggravate HCV recurrence. Histological examination of liver biopsy remains the gold standard for diagnosis of acute rejection but has failed in the past to distinguish between acute rejection and recurrent hepatitis C. We have recently reported that C4d as a marker of the activated complement cascade is detectable in hepatic specimen in acute rejection after liver transplantation. In this study, we investigate whether C4d may serve as a specific marker for differential diagnosis in hepatitis C reinfection cases. Immunohistochemical analysis of 97 patients was performed. A total of 67.7% of patients with acute cellular rejection displayed C4d-positive staining in liver biopsy whereas 11.8% of patients with hepatitis C reinfection tested positive for C4d. In the control group, 6.9% showed C4d positivity. For the first time we were able to clearly demonstrate that humoral components, represented by C4d deposition, play a role in acute cellular rejection after LTX. Consequently C4d may be helpful to distinguish between acute rejection and reinfection after LTX for HCV.

Acute Disease↗
PubMed2006

Plasma homocysteine levels in multiple sclerosis.

BACKGROUND: There is evidence that homocysteine contributes to various neurodegenerative disorders, and elevated plasma homocysteine levels have been observed in patients with multiple sclerosis (MS). OBJECTIVE: To investigate if and why plasma homocysteine levels are increased in MS, and whether they play a role in the disease course. METHODS: We compared plasma levels of homocysteine in 88 patients with MS and 57 healthy controls. In the MS group, 28 had a benign course, 37 were secondary progressive, and 23 primary progressive. To explore the underlying mechanisms, we measured serum levels of vitamins B6 and B12, folate, interleukin (IL)-12, tumour necrosis factor (TNF)-alpha, leukocyte nitric oxide production, and plasma diene conjugate levels (measure of oxidative stress). RESULTS: Mean (SD) plasma homocysteine concentration was higher in patients (13.8 (4.9) micromol/l) than in controls (10.1 (2.5) micromol/l; p<0.0001). However, there were no significant differences in homocysteine levels between the three clinical subgroups of MS. Serum concentrations of vitamin B6, vitamin B12, and folate were not different between patients with MS and controls. In the MS group, there were no correlations between plasma homocysteine levels and the serum concentrations of IL-12 or TNF-alpha, leukocyte nitric oxide production, or plasma diene conjugate levels. CONCLUSIONS: Elevated plasma homocysteine occurs in both benign and progressive disease courses of MS, and seems unrelated to immune activation, oxidative stress, or a deficiency in vitamin B6, vitamin B12, or folate.

Aged↗
PubMed2006

Specific immune recognition of pancreatic carcinoma by patient-derived CD4 and CD8 T cells and its improvement by interferon-gamma.

Pancreatic carcinoma is a very aggressive disease and little is known about its immunobiology. We here describe the presence in pancreatic cancer patients of spontaneously induced functional CD4 and CD8 memory/effector T cells reactive to autologous tumor cells or to the pancreatic cancer associated antigen, MUC-1. Such specific cells were present in the bone marrow or peripheral blood of most of the 23 tested patients. Low dose stimulation of primary cultures of pancreatic cancer cells with 500 IU/ml IFN-gamma for 72 h enhanced HLA-I expression and induced the de novo expression of HLA-II molecules. This led to a much better immune recognition by autologous HLA-I restricted and purified CD8 T cells and allowed tumor cell recognition by HLA-II restricted purified CD4 T-helper cells. Thus, interferon-gamma appears to be a useful adjuvant cytokine to enhance the immunogenicity of a patients' tumor cells and their recognition by tumor reactive immune cells.

Aged↗
PubMed2006

Successful maintenance of continuous ambulatory peritoneal dialysis in a patient after fungal peritonitis and dialysate leakage.

Fungal peritonitis (FP) and dialysate leakage have often been reported in association with continuous ambulatory peritoneal dialysis (CAPD), which has to be discontinued in many cases due to these complications. This report describes the first case of dialysate leakage into the urinary bladder of a 70-year-old male patient, after the area of the left ureteral ostium had been very deeply resected. The leakage probably led to severe fungal peritonitis developing 1 day after the ostium resection. The ostium resection was performed in November 2003 after detection of a carcinoma in situ (Cis) in this area and after previous bilateral nephroureterectomies due to multifocal urothelial carcinoma in the kidneys, ureters and bladder. In spite of prior fungal peritonitis and dialysate leakage, CAPD could be successfully initiated 41 days after biochemical manifestation of peritonitis and could be maintained in the patient because of the following reasons: early and effective treatment of FP with fluconazole and voriconazole, spontaneous occlusion of the slitted ostium area, allowance of enough healing time after 2 major abdominal surgeries, during which the patient was placed on extracorporal hemodialysis (which had been started 1 day after nephroureterectomy and ended after the antimycotic treatment) and thorough monitoring of the patient after starting CAPD. In January 2004, the patient could be placed on a cycler peritoneal dialysis and was fully rehabilitated 1 year later.

Aged↗
PubMed2005

Organic pollutants in sediment cores of NE-Germany: comparison of the marine Arkona Basin with freshwater sediments.

During a contamination survey in NE-Germany sediment cores were sampled at 5 locations with freeze-coring devices and conventional box-coring systems. In total more than 40 samples were analysed for several organic compounds (136 PCDD/F, 33 PCB, 39 PAH, 10 DDX, 4 HCH, 4 CB), sedimentological parameters (TOC,TC,TIC,LOI), some total trace metals (Pb,Cd,Cr,Cu,Zn) and dated by measurement of the (210)Pb and (137)Cs activity. The deepest segment of the cores from the Arkona Basin and the freshwater lakes were dated back to the end of the 19th century. A comparison of marine versus freshwater data is presented. The contamination levels of Arkona Basin were often lower than anthropogenically influenced freshwater sediments and more similar to a freshwater sediment core only influenced by deposition, with an additional Oder River inflow. Differences in patterns and contamination levels are discussed.

Environmental Monitoring↗
PubMed2005

Evolution of clinical behaviour in Crohn's disease: predictive factors of penetrating complications.

BACKGROUND AND AIMS: Crohn's disease is a heterogeneous entity. The Vienna Classification defines three different clinical patterns: 'non-stricturing, non-penetrating', 'stricturing' and 'penetrating'. Aim of this study was to assess the change in clinical behaviour over time and to evaluate whether an evolution towards penetrating complications can be predicted. METHODS: A total of 139 patients with non-penetrating behaviour at the time of diagnosis were included. The mean follow-up was 4.84 years (range 1-23.2 years). The clinical behaviour, according to the Vienna Criteria, was assessed at the diagnosis and at the end of follow up. Statistical analysis was performed by means of the Kaplan-Meier method and standard logistic regression analysis. RESULTS: The cumulative probability of a change in clinical behaviour was 22, 38 and 63% at 3, 6 and 12 years, respectively, and the cumulative probability of developing penetrating complications was 22, 33 and 55% at 3, 6 and 12 years, respectively. Young age at diagnosis (<40 years) and a stricturing behaviour are independent risk factors of developing major penetrating complications (internal fistula, mass or abscess): OR=6.0, 95% CI 1.1-30.5; OR=4.0, 95% CI 1.5-10.9, respectively, but not perianal disease. CONCLUSIONS: The behavioural classification of Crohn's disease is a dynamic model in which each status should be considered as not fixed but evolutive. Perianal disease should be considered a distinct pattern of penetrating behaviour.

Adult↗
PubMed2005

[Dose-effect relation in revision surgery for consecutive strabismus divergens in adults].

BACKGROUND: The aim of this study was to establish a dose-effect relationship between the reduction of the angle of deviation and the millimeters of the reoperation performed in patients with consecutive exotropia. PATIENTS AND METHODS: A total of 46 patients who had undergone reoperation for consecutive exotropia (group 1: advancement of the former recessed medial rectus muscle and group 2: additional rececession of the lateral rectus muscle) were reexamined. RESULTS: The dose-effect relationship was 2 degrees /mm in group 1 and1.6 degrees /mm far distance and 1.8 degrees /mm near in group 2. Within the first 4 months after the reoperation we found an exodrift of up to 6 degrees , which remained stable; 98% of our patients reported that their quality of life had improved. CONCLUSION: In cases of consecutive exotropia we consider the postoperative exdodrift in the planing of our reoperation. During the ensuing years patients can expect stability of the results achieved by the reoperation.

Adult↗
PubMed2005

[Introduction].

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Antineoplastic Agents↗
PubMed2005

[Acronycine revisited: development of benzo[b]acronycine antitumor agents].

The acridone alkaloid acronycine, isolated from several Sarcomelicopespecies (Rutaceae) was shown to exhibit a promising activity against a broad spectrum of solid tumors. Nevertheless, subsequent clinical trials gave limited results, probably due to the moderate potency and poor water solubility of this drug. The isolation of the unstable acronycine epoxide from several New-Caledonian Sarcomelicope led to a hypothesis of bioactivation of acronycine by transformation of the 1,2-double bond into the corresponding oxirane in vivo. Consequently, we synthesized a series of cis-1,2-dihydroxy-1,2-dihydroacronycine diesters which exhibited interesting antitumor properties with a broadened spectrum of activity and an increased potency when compared with acronycine. The demonstration that acronycine should interact with DNA prompted us to develop benzo[b]acronycine analogs possessing an additional aromatic ring linearly fused on the natural alkaloid basic skeleton. In vivo, 1,2-dihydroxy-1,2-dihydrobenzo[b]acronycine esters and diesters, exemplified by cis-1,2-diacetoxy-1,2-dihydrobenzo[b]acronycine developed under the code S 23906-1, demonstated a marked antitumor activity in human orthotopic models of lung, ovarian and colon cancers xenografted in nude mice. The cytotoxic and antitumor activities of these compounds were strongly correlated with their ability to give covalent adducts with purified as well as genomic DNA. Such adducts involve reaction between the exocyclic N-2 amino group of guanines exposed in the minor groove of double helical DNA and the leaving ester group at the benzylic position 1 of the drug.

Animals↗