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Biomedical subjects

H K Koch

Publications and source records attributed to H K Koch.

At least 19 recordsLinked to original sources
PubMed2003

[Histopathological diagnosis of Barrett's mucosa and associated neoplasias. Results of a consensus conference of the Working Group for "Gastroenterological Pathology of the German Society for Pathology" on 22 September 2001].

There are a number of difficulties regarding the diagnosis of Barrett's mucosa and the varying grades of neoplasia that may be associated with it. It was therefore the aim of a consensus conference of the "Working Group for Gastroenterological Pathology within the German Society of Pathology" to achieve standardization regarding the following issues: definition and diagnostic criteria for Barrett's mucosa and its discrimination from intestinal metaplasia of the cardia, diagnostic criteria for intraepithelial neoplasia, number of biopsies necessary to establish the diagnosis, significance of additional immunohistochemical and/or molecular biological methods as well as importance of a second opinion in the diagnosis of intraepithelial neoplasia.

Barrett Esophagus↗
PubMed1998

Efficacy of tetracycline and metronidazole alone or with ranitidine on the healing of duodenal ulcer and eradication of Helicobacter pylori. A randomized controlled multicenter study. Tetra-Metro-Ran Study Group.

In almost all eradication regimens, which contain antibiotics and bismuth derivatives, the administration of acid suppressing drugs for 4-6 weeks is recommended for healing of duodenal ulcer. The aim of this multicenter double blind study is to elucidate the effect of two classic antibiotics tetracycline (CAS 60-54-8) and metronidazole (CAS 443-48-1) alone or combined with ranitidine (CAS 66357-35-5) on the healing of duodenal ulcer and eradication of Helicobacter Pylori. Patients with duodenal ulcer were randomized to two treatment groups: group A received either ranitidine 4 x 150 mg or tetracycline 4 x 500 mg or metronidazole 3 x 250 mg for 2 weeks. Group B received 4 x placebo + tetracycline and metronidazole as in group A for 2 weeks. A final endoscopy was performed after 8 weeks. Four biopsy specimens were obtained from the antrum (two) and corpus (two) for both urease test and hematoxylin stain for detection of H. pylori. Out of 201 patients entering the study 156 completed the study (78 in A and 78 in B). The healing rate of duodenal ulcer was 98.7% in group A and 97.5 in group B. The eradication rate was only 33.3% in group B but 64% in group A (p < 0.001), when additionally ranitidine was given. The present study shows that treatment with the two antibiotics tetracycline and metronidazole alone results in a very low H. pylori eradication, but almost complete healing of duodenal ulcer after 8 weeks. Prolonged administration of antisecretory drugs in eradication regimens containing two antibiotics is not necessary for duodenal ulcer healing. However, the addition of H2-receptor antagonists or proton pump inhibitors to antibiotics increases the eradication rate.

Anti-Bacterial Agents↗
PubMed1994

The use of proliferating cell nuclear antigen (PCNA) expression and intraepithelial lymphocyte count in the differential diagnosis of inflammatory bowel disease.

Colonic biopsies of 283 patients with Crohn's disease (CD), ulcerative colitis (UC), infectious colitis (IC) lymphocytic colitis (LC) and controls for patients with either CD or UC, matched for age and sex, were evaluated with respect to the number of intraepithelial lymphocytes (IEL) and PCNA (cyclin) positive crypt epithelia. The IEL count of patients with LC differed significantly from all other patient groups, indicating that this condition bears no relation to the other diseases. Our patients with histologic diagnosis of LC had no uniform clinical presentation and the significance of this characteristic increase in IEL is unclear. The mean value of PCNA positive crypt epithelia in the lower crypt half was significantly higher in UC patients than in CD patients. PCNA counts in patients with IC or LC were not different from values in UC patients. PCNA counts in CD patients overlapped frequently with those in UC patients. This parameter thus fails to distinguish between CD and UC in individual patients and, though not investigated by us, is unlikely to be effective in the differential diagnosis in patients with a provisional diagnosis of indeterminate colitis.

Adult↗
PubMed1992

Serodiagnosis of Helicobacter pylori infections with an enzyme immunoassay using the chromatographically purified 120 kilodalton protein.

A membrane-associated 120 kDa protein of Helicobacter pylori with known species-specificity was isolated and used in an enzyme immunoassay (EIA) for the detection of Helicobacter pylori-specific IgG antibodies in patient sera. The EIA was compared with two other methods used for serodiagnosis of Helicobacter pylori infections: an EIA using sonicated whole Helicobacter pylori cell antigen and Western immunoblot. In a prospective study 127 unselected patients (76 patients with antrum gastritis, 51 patients without gastritis) who underwent gastroscopy were studied histologically and serologically. The EIA using the purified 120 kDa protein had the highest specificity (92%) compared with the EIA using a whole cell sonicate of a single Helicobacter pylori strain as antigen (60.7%) and the immunoblot (90.2%). The sensitivity was 96%, 100% and 92%, respectively. Sera of three control patients reacted strongly in all three methods, indicating possible Helicobacter pylori infection with negative histological findings. The EIA using the 120 kDa protein as antigen was shown to be a specific and sensitive technique for the serodiagnosis of Helicobacter pylori infections.

Adult↗
PubMed1991

A simple and rapid method for the detection of RNA in formalin-fixed, paraffin-embedded tissues by PCR amplification.

A simple and rapid method for the extraction, reverse transcription and PCR amplification of RNA from formalin-fixed, paraffin-embedded tissue is described. The procedure can be completed within 24 hours. In a first application of this method we detect human albumin mRNA in liver tissue, demonstrating the feasibility to retrospectively analyze gene expression and RNA viruses in fixed tissue.

Albumins↗
PubMed1990

An evaluation of gastric dysplasia in the years 1986 and 1987.

Since the fate and significance of gastric mucosal dysplasia is still largely unknown we have started a follow-up study for patients with dysplasia in the years 1986 and 1987. In this paper the short term results are reported. Dysplasia grade II was found in 2% of all patients and dysplasia grade III in 0.5%. The following results suggest a close-possibly sequential relationship of dysplasia and gastric cancer: dysplasia and gastric cancer are preferentially located in distal parts of the stomach; sex distribution of dysplasia and gastric cancer (especially intestinal type) are similar; considering the mean age of patients with dysplasia or gastric cancer we have observed that patients with dysplasia II were younger than patients with dysplasia III and both were younger than patients with gastric cancer of the intestinal type; during the short term follow-up (12-24 months) 4-8% of patients with dysplasia II and 18-20% of patients with dysplasia III showed a progression; of 26 carcinomas detected by follow-up of patients with dysplasia III 10 were early gastric cancer, 11 resectable with curative intent, 2 were metastatic and 3 without sufficient information for staging. We conclude therefore that gastric dysplasia is probably a true precancerous lesion that helps to identify high risk patients and thus contributes to the objective of an early diagnosis of gastric cancer.

Aged↗
PubMed1990

Malignant pleural mesothelioma: some aspects of epidemiology, differential diagnosis and prognosis. Histological and immunohistochemical evaluation and follow-up of mesotheliomas diagnosed from 1964 to January 1985.

64 diffuse pleural mesotheliomas diagnosed between 1964 and January 1985 at the Institute of Pathology of the University of Freiburg were analyzed. Since 1980 an increase from one case to 10 cases per year has been observed. The tumor was 3 to 4 times more frequent in men than in women. The age distribution showed a peak between the age of 50 and 60. In 26 cases evidence of exposure to asbestos was detected. In one patient radiotherapy of Hodgkin's disease may have been of etiological significance. The median survival time was 13 months. The five-year survival rate was only 4%. Histologic reevaluation was only possible in cases diagnosed after 1975. Of 43 cases thus evaluated 26 were pure mesothelial, 15 biphasic and 2 of the spindle-cell subtype. A median survival time of 23 months for pure mesothelial mesothelioma in comparison to 13 months for the biphasic mesothelioma indicated a better prognosis for pure mesothelial mesothelioma. Although no other primary tumors were detected, in 10 cases the differential diagnosis of adenocarcinoma had to be considered, and in 3 cases tumors of non-epithelial origin had to be excluded. 35 of 43 mesothelioma were CEA-negative, 38 out of 43 cytokeratin-positive, and 33 out of 43 were EMA-positive. Factor-VIII-related antigen was not demonstrated. 12 of 43 mesotheliomas showed PAS-positive staining, 29 of 43 were stained with Alcian blue. 7 of these 29 showed a positive digestion with hyaluronidase. Although CEA may not be negative in every mesothelioma, this marker seems to be a valid tool for the differential diagnosis of adenocarcinoma. In order to safeguard against a mistaken diagnosis of pleural mesothelioma, the exclusion of other tumors is always indispensable.

Adult↗
PubMed1990

Prevalence of Campylobacter pylori as demonstrated by histology or CLO-test in different types of gastritis. A study in 5 clinically predefined groups of patients.

The prevalence of Campylobacter pylori infection as detected by histology was studied in 5 predefined groups of patients. The associated histologic and endoscopic findings were registered. Validity of CLO-test was tested against the histologic detection. The following groups of patients were studied: A) Non-ulcer dyspepsia (defined by one or all of three symptoms: heartburn, nausea/inappetence, halitosis/belching) B) control group (no specific symptoms, no ulcer, no history of gastric surgery) C) Duodenal ulcer D) Gastric ulcer E) Billroth I or II resection of the stomach. 200 patients were recruited for group A-C, in group D 134 patients and in group E 113 patients were studied. A mean prevalence of 60% was observed. Prevalence was highest in patients with duodenal ulcer (86%). In group D a prevalence of 65%, in A and E a prevalence of 54%, and in B of 40% were seen. The overall test sensitivity of the CLO-test compared against the histologic detection rate was 75%, the specificity 81%. Sensitivity was reduced in group A (69%) and E (53%) and in patients with inactive chronic gastritis (67%). In all groups patients with active forms of gastritis showed the highest prevalence of C. pylori infection. The specificity of the CLO-test was reduced in patients with duodenal ulcer (46%) and gastric ulcer (48%). Decreased specificity observed after therapy with histamin receptor (H2) blockers may explain this finding. The relationship of C. pylori infection with active types of gastritis or gastro-duodenal ulcer hints at a causal relation but is no definite proof of its etiologic role. The validity of the CLO-test seems questionable in patients with gastroduodenal ulcer or operated stomach.

Antacids↗
PubMed1986

Benign circumscribed lesions of the liver diagnosed by ultrasonically guided fine-needle biopsy.

Cytologic evaluation of aspirates obtained by ultrasonically guided puncture of circumscribed lesions leads to the diagnosis of a malignant lesion when tumor cells are detected. In the absence of tumor cells, it remains uncertain whether the focus had been biopsied correctly, since the histologic diagnosis of a benign focal lesion can only occasionally be made by means of cytologic smears. Cases are presented showing circumscribed lesions of the liver. With a cut-biopsy fine needle, small cylinders of tissue were obtained under ultrasonic guidance and examined after histologic preparation. In each case, a benign focal lesion could be diagnosed, proving that the observed lesion had been correctly biopsied.

Adult↗
PubMed1985

Drug-induced liver injury in liver biopsies of the years 1981 and 1983, their prevalence and type of presentation.

Based on the histological picture of liver biopsies examined in the years 1981 and 1983, drug-induced liver injury has been suspected in 131 and 170 cases. In relation to the total number of the examined liver biopsies this accounted for 6 and 9.6%, respectively. In only 20 (i.e. 15%), respectively 17 (i.e. 10%) of the cases, a drug-induced injury could be clinically excluded. However, a drug-induced injury was doubtlessly secured in 21 (16%) and 28 (16.5%) of the cases. The histological phenotype seen in association with the incriminated drug is presented. In 90 (68.7%) and 125 (73.5%) of the cases it was neither possible to secure nor to exclude the drug as cause of this damage, either because in 32/72 cases the clinical work-up was incomplete or because the drug-induced damage was clinically suspected, but not sufficiently documented by follow-up examinations after drug-withdrawal.

Adolescent↗
PubMed1985

[Hemorrhage into a liver adenoma associated with long-term use of oral contraceptives].

A 39-year-old woman was evaluated for acute midepigastric pain. The patient was never severely ill; her only medication was an oral contraceptive (OC) which she took regularly over the last 12 years. Abdominal ultrasonography and computed tomography revealed bleeding into a liver tumor. At laparoscopy, 3 adenomas of the liver were detected. Bleeding was restricted to 1 tumor and did not require surgical intervention. OC medication was discontinued, and the patient was followed over more than 3 years. The patient was doing very well; ultrasonographically, the liver tumors became gradually smaller.

Biology↗
PubMed1984

[A new fine needle biopsy technic in histologic diagnosis--preliminary case report].

Sonographically guided puncture of intra-abdominal and retro-peritoneal masses for cytological diagnostic is widely employed. However, processing of cytological material may result in artifacts and in the case of certain malignant tumours, of benign tumours or diffuse organ changes, cytology is only relatively reliable. Special experience on the part of the investigato is therefore required. Hence, in far-reaching therapeutic decisions such as operation, cytostatic therapy or radiotherapy, diagnosis based on histological findings is preferred. Preliminary experience with a new type of fine needle (Schneidbiopsiekanüle) suitable for obtaining histological material is presented.

Adult↗
PubMed1983

[Gluten-sensitive enteropathy--in the light of new clinical and pathogenetic aspects].

The corn protein gluten causes the gluten-sensitive enteropathy in susceptible persons (HLA-antigens). The diagnosis is made on the basis of the morphological criteria of villous atrophy of the jejunal mucosa and the clinical observation that the malabsorption can be healed by a gluten-free diet. The disease, which occurs in children and adults, is a distinct entity. Life-long adherence to a gluten-free diet is difficult. Intentional or unintentional reintroduction of gluten often causes masked disease states. These are best classified on the basis of electron-microscopy study of the jejunal biopsy. We propose a new classification of the phases of remission. A group of diseases exist which are closely related to gluten-sensitive enteropathy. Frequently villous atrophy is detectable. However, the disease does not respond to a gluten-free diet. The pathophysiology of these diseases is at present unclear. Diseases involving autoimmune processes also appear to be associated with gluten-sensitive enteropathy. The common factor is probably an immuno-genetic defect. This is supported by the existence of common HLA-antigen constellations. Gluten has been characterised in vitro as a lectin with oligomannose specificity. This provides a new pathomechanism for the gluten induced enterocytic destruction.

Celiac Disease↗
PubMed1982

[The effect of diatrizoate (Angiografin) on the aortic endothelium of the rat in shock].

Investigations have been carried out on the endothelial damage produced by diatrizoate (Angiografin) during the course of endotoxin shock. A single injection was given directly into the aorta of 1 ml of the contrast medium, with an iodine content of 300 mg/ml. The increased proliferation of the aortic endothelium could be shown to be due to the endotoxin shock, but was not further increased by administration of the contrast medium.

Animals↗
PubMed1982

Follow-up of treated adult celiac disease: clinical and morphological studies.

A follow-up study of 18 patients with celiac disease is reported. Adherence to the diet, blood chemistry and serum amino acid concentration were investigated in all patients. In addition, HLA blood group typing was performed. Ten patients agreed to undergo jejunal biopsy, xylose test and X-ray of the small intestine. The jejunal mucosa showed no complete restitution even in patients on a strict diet and function tests were abnormal, too. In this study HLA typing demonstrated an association with HLA-B8, HLA-DR3, and HLA-DR7. The results of the follow-up study are discussed with special reference to therapeutic aim and definition of therapeutic success of the gluten-free diet. In addition, a case of jejunal adenocarcinoma complicating celiac disease is presented.

Adenocarcinoma↗