Search PubMed⌕ Search

Biomedical subjects

B Wiebecke

Publications and source records attributed to B Wiebecke.

At least 37 records · Page 2Linked to original sources
PubMed1995

Rectal suction biopsy: can it be sufficient to diagnose neuronal intestinal dysplasia?

Rectal suction biopsy is the diagnostic procedure of choice in aganglionosis even if only mucosal tissue is obtained. In neuronal intestinal dysplasia it is essential to include parts of the submucous layer. Therefore some biopsies are unsuitable because they lack submucous tissue. In a retrospective analysis (1991-1993) this occurred in 34.9% of our biopsies. These samples were taken without attention to the level of suction. Prospectively we compared suction biopsies taken by a standard suction level (250-300 cm water column) with excision biopsies taken by scissors under speculum exposure in ten consecutive patients. Submucosa was missed in only one biopsy each, but two excision biopsies were made useless by mechanical traumatization. We conclude a correctly practised rectal suction biopsy still remains the procedure of choice for diagnostic screening in malformations of the enteric nervous system.

Biopsy↗
PubMed1995

Unconjugated secondary bile acids in the serum of patients with colorectal adenomas.

A positive association between deoxcholic acid (DCA) in the serum and colorectal adenomas, the precursors of colorectal cancer has recently been found, which supported the hypothesis of a pathogenic role of DCA in colonic carcinogenesis. This approach was based on the hypothesis that DCA formed in the colon is absorbed into the portal venous blood and exhibits a constant spillover to the systemic circulation. To further substantiate this hypothesis this study investigated whether in the serum of adenoma patients DCA was higher in the unconjugated fraction, which originates directly from the colon. DCA was found to be 2.8-fold higher in the unconjugated fraction of patients with colorectal adenomas than in controls (0.89 v 0.32 mumol/l, p < 0.0025), 1.9-fold in the total DCA fraction (1.89 v 0.95 mumol/l, p < 0.0001), and 1.4-fold in the conjugated fraction (0.67 v 0.47 mumol/l, p < 0.05). It was further found that the bacterial isomerisation product 3 beta-DCA was twofold higher in the unconjugated fraction of adenoma patients than in controls (0.08 v 0.04 mumol/l, p = 0.27), 1.8-fold in the total iso-DCA fraction (0.11 v 0.06 mumol/l, p < 0.05), and 1.5-fold in the conjugated iso-DCA fraction (0.03 v 0.02 mumol/l, p = 0.68). The data suggest that the positive association between the serum DCA concentration and colorectal adenoma as described previously results from the DCA fraction that is absorbed from the colon. This further supports a pathogenic role of DCA in the carcinogenesis of colorectal cancer.

Adenoma↗
PubMed1993

Decreased high-density lipoprotein cholesterol and increased low-density cholesterol levels in patients with colorectal adenomas.

OBJECTIVE: To study the relation between serum lipoprotein levels and the frequency of colorectal adenomas, the benign precursors of colorectal cancer. DESIGN: Cross-sectional. SETTING: University hospital in Germany. PATIENTS: The study included 822 of 1124 consecutive patients who underwent colonoscopy at our institution (302 patients were excluded because of malignant disease, chronic inflammatory bowel disease, familial polyposis, partial colectomy, or other chronic diseases). Of the 822 study patients, 194 had colorectal adenoma. MEASUREMENTS: Serum cholesterol fractions (high-density lipoprotein [HDL], low-density lipoprotein [LDL], and very low-density lipoprotein [VLDL]) and presence or absence of adenomas; univariate and logistic regression analyses were carried out to evaluate the association between serum HDL, LDL, and VLDL cholesterol levels and the frequency of colorectal adenoma. RESULTS: Univariate analysis of the total patient group showed that the HDL cholesterol level was inversely related to the frequency of colorectal adenoma (odds ratio, 0.36; 95% Cl, 0.21 to 0.62) and that LDL and VLDL cholesterol levels were positively associated with adenoma frequency (odds ratio, 2.31 [Cl, 1.36 to 3.92] and 1.72 [Cl, 1.03 to 2.86], respectively). Univariate analysis of the subgroup of 89 patients with high-risk adenomas showed an inverse association between such adenomas and HDL cholesterol (odds ratio, 0.37; Cl, 0.18 to 0.76). A logistic regression analysis that included age and body mass index showed an association between lipoprotein levels and the presence of adenomas. The relative strength (in descending order) of these associations was as follows: HDL, LDL, VLDL, and total serum cholesterol. A logistic regression analysis of patients with high-risk adenoma showed a significant association between such adenomas and the HDL cholesterol level. CONCLUSIONS: Patients with colorectal adenomas have lower HDL cholesterol levels and higher LDL and VLDL cholesterol levels; these lipoproteins may have prognostic significance for the development of colorectal adenomas.

Adenoma↗
PubMed1993

Increased risk of 'high-risk' colorectal adenomas in overweight men.

BACKGROUND: Epidemiologic studies have suggested that the incidence of colorectal carcinoma may be related to overnutrition, but retrospective analysis of its relation to the body mass index (BMI: kg/m2) has produced conflicting data. METHODS: To avoid as many sources of statistical bias as possible, the relation between BMI and the presence of colorectal adenomas was investigated in a cross-sectional study. RESULTS: Two thousand twelve consecutive colonoscoped patients were investigated (532 patients with malignancies or other conditions associated with weight loss were excluded). The relation between BMI and observed colorectal adenomas was evaluated by a logistic model controlling for other prognostic factors such as age, sex, and serum cholesterol level. The subgroup of "high-risk" adenomas with an increased risk of malignant transformation was positively associated with the BMI in men of the age group 50.5-68.1 years (quintiles III and IV: odds ratio for the top quintile vs. the lowest quintile, 3.21; 95% confidence interval, 1.15-8.98). CONCLUSIONS: It was concluded that the risk of developing high-risk adenomas tends to be increased in men who are overweight and that this association is independent of the positive association with the serum cholesterol level recently described.

Adenoma↗
PubMed1993

Increased serum deoxycholic acid levels in men with colorectal adenomas.

BACKGROUND: Epidemiological and animal studies have suggested that the secondary bile acid deoxycholic acid is cocarcinogenic in colorectal cancer, but this hypothesis was not confirmed by case-control studies investigating fecal bile acids. METHODS: Individual serum bile acid concentrations were investigated in 25 men and 25 women with colorectal adenomas and in an equal number of age- and sex-matched controls by gas-liquid chromatography. RESULTS: Deoxycholic acid levels were significantly higher in the sera of men with colorectal adenomas (1.70 +/- 0.59 vs. 1.16 +/- 0.39 mumol/L, P < 0.0005) and in a combined analysis of both sexes (1.47 +/- 0.78 vs. 1.08 +/- 0.39 mumol/L, P < 0.0025). Six- and 12-month follow-up measurements of deoxycholic acid concentrations in a subgroup of 22 men and 17 women showed higher serum levels in men with adenomas, indicating that measurement of deoxycholic acid concentration may be a reliable parameter to investigate its pathogenetic role in colonic neoplasia. CONCLUSIONS: The data of this study support the hypothesis that deoxycholic acid may play a role in the pathogenesis of colorectal cancer.

Adenoma↗
PubMed1993

New morphological findings in so-called negative appendectomies.

Appendices of children operated on because of clinical signs of acute appendicitis and presenting normal histological findings were revised by means of special assays. These findings were then compared with appendectomies during abdominal surgery, catarrhal and early phlegmonous appendicitis. We found pathological changes of the epithelium and the lymphatic tissue in more than two thirds of the specimens originally classified as normal. Therefore the term of "negative appendectomy" has to be redefined.

Acute Disease↗
PubMed1993

[Increasing the survival rate of endangered free microvascular tissue transplants using a prostacyclin derivative].

Free flap transplantations and replantations of extremities are threatened by venous occlusion due to haematomas, contusions, and secondary healing of the surrounding tissues. In an experimental investigation in 18 Sprague-Dawley-rats, the influence of the Prostacyclin analogue Iloprost on temporary ischemia by venous occlusion was tested. Free groin flaps were transplanted to the neck of these animals with microanastomoses of the nutrient superficial epigastric vessels to the carotid artery and the jugular vein. On the first postoperative day the vein was temporarily clamped. In the control group there was always a total loss of the flap by haemorrhagic necrosis. The intraarterial flap perfusion by Iloprost was able to diminish the effects of the secondary ischemia. In some cases shortly after the perfusion and always on the next day, positive oxygen pressures were measurable. 80% of the flaps survived.

Animals↗
PubMed1993

[Experimental studies of the no-reflow phenomenon with prostacyclin].

The no-reflow phenomenon is a dreaded complication in free tissue transplantations. After a critical period of warm ischemia, insufficient reflow is observed after vessel anastomosis and opening of the artery. In an experimental study in 72 rats, groin flaps were harvested with the nutrient superficial epigastric vessels and transplanted to the neck using a microvascular technique with anastomoses to the carotid artery and jugular vein. Before transplantation, the isolated flaps were perfused either with saline solution, with Iloprost, with and without heparin, or the nutrient vessels were simply flushed with heparin solution. After saline perfusion, there was no venous reflow, after pure Iloprost perfusion, there was venous return in 26% of the flaps, after Heparin-Iloprost perfusion in 88% and after flushing with heparin alone in 93%. The addition of heparin to Iloprost seems to improve the reflow rate. The most effective protection against a no-reflow phenomenon, however, is flushing the nutrient vessels with a heparin solution.

Anastomosis, Surgical↗
PubMed1992

Ursodeoxycholic acid for treatment of primary sclerosing cholangitis: a placebo-controlled trial.

The efficacy and safety of ursodeoxycholic acid for the treatment of primary sclerosing cholangitis were evaluated in a prospective, randomized, double-blind, placebo-controlled trial. Fourteen patients with primary sclerosing cholangitis documented by cholestatic serum enzyme pattern, liver histological appearance and endoscopic retrograde cholangiography were included in the trial. Six patients received ursodeoxycholic acid (13 to 15 mg/kg body wt/day), and eight patients received placebo. Two patients had to be withdrawn from the study, one because of UDCA-related diarrhea and the other because of worsening of the disease during placebo treatment. Patients in the ursodeoxycholic acid group improved significantly during 1 yr of treatment with respect to serum levels of bilirubin (median = -50%), alkaline phosphatase (median = -67%), gamma-glutamyltransferase (median = -53%), AST (median = -54%) and ALT (median = -36%) compared with the placebo group, but not with respect to serum levels of hydrophobic bile acids. During ursodeoxycholic acid treatment, histopathological features also improved significantly, as evaluated by multiparametric score. Expression of human leukocyte antigen class I molecules appeared to be markedly reduced on liver cells after ursodeoxycholic acid treatment. We conclude that ursodeoxycholic acid is beneficial in reducing disease activity in patients with primary sclerosing cholangitis.

Adolescent↗
PubMed1992

Excessive collagen formation in fibrolamellar carcinoma of the liver: a morphological and biochemical study.

We have studied the excessive deposition of extracellular matrix in a patient with fibrolamellar carcinoma of the liver. The collagen matrix was predominantly composed of collagens I, III, and V. Since specific mRNAs for collagens I and III were detected by in situ hybridization, we also provide evidence that the fibroblastoid stromal cells were the major source of this collagen. Occasionally, also tumor cells could be shown to express collagen III-mRNA. Furthermore, some tumor cells showed positive signals for TGF-beta 1, while isolated stromal cells expressed interleukin-6. This cytokine expression may probably be related to the altered control of collagen gene expression.

Adolescent↗
PubMed1992

[Crohn disease in advanced age].

Crohn's disease of late onset (greater than 65 years) is rare condition. Typical features are the localisation in the distal gastrointestinal tract and the presence of associated diseases such as cardiovascular disorders and/or diverticulitis. In about 25% of the cases mild intestinal hemorrhage occurs. Delay in diagnosis is sometimes due to coexistent diverticulitis. Ischemia has been suggested to be responsible for the development of the histological changes which occur in Crohn's colitis. Therefore, we carried out a retrospective analysis of our patients treated between 1978-1988 to reevaluate the resected specimens. 10 patients (6.2% of all surgical patients with Crohn's disease) were at least 65 years old at the time of primary operation. In 5 cases hematochezia was one of the symptoms before operation, two patients presented with massive hemorrhage of the lower GI-tract. Granulomas were seen only in 5 patients, whereas in all specimens transmural inflammation was detected. In 8 out of 10 patients vascular lesions were seen, among those thickening of the intimal and medial layers, thrombosis or bleeding. Our findings support the thesis that ischemia might play a role in the pathogenesis of Crohn's disease of late onset.

Aged↗
PubMed1991

Frequent down-regulation of major histocompatibility class I antigen expression on individual micrometastatic carcinoma cells.

An astoundingly high frequency of micrometastatic cells have been found in bone marrow aspirates of patients with colon carcinomas (G. Schlimok et al., J. Clin. Oncol., 8:831-837, 1990), although these tumors very rarely metastasize to the skeleton. This observation has raised questions about the malignant potential of such cells. In a first attempt to characterize this potential, we have assessed the expression of major histocompatibility complex (MHC) class I antigens on bone marrow micrometastases, inasmuch as down-regulation of these molecules is a potential mechanism to escape from MHC class I-restricted lysis by cytotoxic T-cells. The two groups of cancer patients compared were those with tumors known to rarely (stomach and colon cancer) or frequently (breast cancer) manifest skeleton metastases. Bone marrow aspirates taken from these patients were probed for individual disseminated tumor cells using the immunoalkaline phosphatase technique with monoclonal antibody CK2 to the epithelial differentiation antigen cytokeratin 18 (CK-18), as described previously (G. Schlimok et al., Proc. Natl. Acad. Sci. USA, 84:8672-8676, 1987). Specimens containing CK18-positive cells were colabeled with monoclonal antibody W6/32 directed to a framework (or nonpolymorphic) antigenic determinant of MHC class I heavy chains associated with beta 2-microglobulin. W6/32-positive CK-18-positive cells could be detected in 25 of 54 patients (46.3%) with significantly higher incidences in 26 breast cancer patients (61.9%) as compared to 28 patients with carcinomas of the stomach and colon (27.3 and 29.4%). Independent from the origin of the primary carcinoma, the incidence of W6/32-negative CK18-positive cells was positively correlated to both the differentiation grade of the primary tumor (P less than 0.05) and appeared to be linked to the occurrence of regional lymph node metastases (statistically not significant) determined by conventional histological examination. The present results demonstrate for the first time that down-regulation of MHC expression on individual micrometastatic cells correlates to the differential pattern of metastasis obtained by comparing breast and gastrointestinal carcinomas. This finding together with the suggestive link to clinical risk factors supports the significance of reduced MHC class I expression for the survival of residual metastatic cells which is a major determinant of prognosis for patients with solid tumors.

Adenocarcinoma↗
PubMed1991

[Leiomyosarcoma of the external ear canal].

We report on a 45-year-old male patient with the signs of exophytic, obstructive and painless tumour of the right external auditory canal developed within a period of about 3 months. The tumour was completely removed in local anaesthesia and histologically found to be a leiomyosarcoma. The only possible origin of this lesion might be the smooth muscle cells of the local blood vessels or the mm. arrectores pilorum.

Ear Canal↗
PubMed1991

Klinefelter's syndrome and liver adenoma.

We describe the occurrence of a liver adenoma in a young patient with Klinefelter's syndrome, diagnosed by classic 47,XXY karyotype in all investigated cells and a sex hormone imbalance. To our knowledge, this is the first report of such an association, which might suggest a simple coincidence. However, a pathogenetic link between Klinefelter's syndrome and liver adenoma can be suggested in view of the following facts: Liver adenoma mostly affects women of child-bearing age using oral contraceptives. It is very rare in men, and affected men frequently have been treated with androgens. Both groups are characterized by a sex hormone imbalance. Also, the risk of breast cancer, another hormone-sensitive tumor, is greatly elevated in men with Klinefelter's syndrome, possibly due to sex hormone imbalance.

Adult↗