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Biomedical subjects

B Wiebecke

Publications and source records attributed to B Wiebecke.

At least 55 records · Page 3Linked to original sources
PubMed1990

Increased epidermal growth factor receptors in gastric carcinomas.

The epidermal growth factor and the homologous alpha-tumor growth factor are mitogenic polypeptides that act by binding to the epidermal growth factor receptor. The present study investigated whether increased production of epidermal growth factor/alpha-tumor growth factor or increased density of epidermal growth factor receptors may occur in gastric carcinomas as compared with normal mucosa from the same individuals. Epidermal growth factor receptors were measurable by (125I)EGF-binding assays in 13 of 15 normal mucosas and in 15 of 15 carcinomas. The epidermal growth factor-binding capacity was significantly higher in carcinomas than in mucosa. A comparison of pairs of mucosa and carcinomas showed an increase of epidermal growth factor receptors in 9 of 15 carcinomas, no change in 3, and a decrease in 2 carcinomas. One mucinous adenocarcinoma contained extreme numbers of epidermal growth factor receptors (2445 fmol/mg protein) corresponding to a 320-fold increase over normal mucosa. Epidermal growth factor-like activity was increased in 2 of 22 carcinomas compared with mucosa. We conclude that relative overexpression of epidermal growth factor receptors occurs in a fraction of gastric carcinomas. Whether increased expression of epidermal growth factor receptors is associated with particular patterns of tumor progression needs to be investigated.

Adult↗
PubMed1989

Epidermal growth factor receptors and epidermal growth factor-like activity in colorectal mucosa, adenomas and carcinomas.

The epidermal growth factor (EGF) and alpha-tumor growth factor are mitogenic proteins which bind to the EGF-receptor and may play a role in carcinogenesis or tumor progression. Our study investigated whether colorectal carcinomas and adenomas express altered levels of EGF-receptors or overproduce EGF-like activity by comparing histologically normal mucosa to carcinomas resected from the same patients. EGF-receptors were characterized by radioligand binding studies. Carcinomas contained unchanged or decreased levels of EGF-receptors in 13/16 and moderately increased levels in 3/16 patients as compared to normal mucosa. Adenomas obtained from 2 patients with familial polyposis coli and from a third patient with a coincident carcinoma had similar numbers of EGF-receptors as normal mucosa. EGF-like growth factors, in contrast, were significantly elevated in carcinoma extracts as compared to extracts from normal mucosa of the same patients. Adenomas did not contain elevated levels of EGF-like activity. We conclude that increased expression of EGF-receptors is infrequent in colonic adenocarcinomas. Increased production of EGF-like growth factors may frequently occur but seems to be associated with tumor progression rather than with premalignant lesions as represented by adenomas.

Adenomatous Polyposis Coli↗
PubMed1989

First description of "Indian childhood cirrhosis" in a non-Indian infant in Europe.

The first female child of healthy German parents, breast-fed for 5 weeks, developed progressive abdominal distension due to hepatosplenomegaly at the age of 7 months and died from acute liver failure 3 months later. Histology showed destruction of liver architecture with extreme hepatocellular copper storage, characteristic of "Indian childhood cirrhosis" (ICC). The family received drinking water from a well via copper pipes. The copper level of the water was extremely elevated (430 and 5510 micrograms/l) so that exogenous copper intake during the first months of life may have induced the fatal liver disease, probably in association with an unproven genetic disposition. This is the first description of a case of ICC in a member of a non-Indian family in Europe.

Copper↗
PubMed1988

Inverse relationship between colonic (Na+ + K+)-ATPase activity and degree of mucosal inflammation in inflammatory bowel disease.

In inflammatory bowel disease (IBD), mucosal damage and loss of colonic function are regarded as major consequences of inflammation. Decreased colonic (Na+ + K+)-ATPase activities with diminished reabsorption of sodium and water have been found in active stages of ulcerative colitis. In this study, we report an inverse relationship between colonic (Na+ + K+)-ATPase activity and the degree of mucosal inflammation in 19 patients with IBD of mild to moderate disease activity. Various macroscopic and histologic types of mucosal lesions were differently associated with the (Na+ + K+)-ATPase activities. 5'-nucleotidase activity was not associated with the degree of mucosal inflammation or the kind of macroscopic or histologic lesions. Our findings support the view that, in contrast to 5H-nucleotidase, (Na+ + K+)-ATPase activity may better reflect the severity of mucosal damage and the degree of inflammation in IBD.

5'-Nucleotidase↗
PubMed1988

Copper storage disease of the liver and chronic dietary copper intoxication in two further German infants mimicking Indian childhood cirrhosis.

A severe copper storage disease of the liver with micronodular cirrhosis resembling Indian childhood cirrhosis (ICC) was found in two siblings of a German family leading to death in one infant at the age of 13 months. The fatal outcome correlated with severe ballooning of hepatocytes and excessive formation of Mallory bodies. The copper content of the liver was 698 micrograms per gramme wet weight (control 5 micrograms) in the living patient and 2154 micrograms per gramme dry weight (controls 39, 54 micrograms) in the dead infant. In both cases copper was stored not only in hepatocytes but also to a high degree in mesenchymal cells. Chronic contamination of drinking water supplied from a well via copper pipes could be verified as the cause of copper intoxication, lending further support to ICC as an environmental, acquired disorder. Accumulation of exogenic copper already very early in infancy appears most important for the development of the disease, as both the parents and one child not exposed to copper intoxication during the first 9 months of its life are clinically healthy.

Chemical and Drug Induced Liver Injury↗
PubMed1988

Thorotrast-induced oro- and hypopharyngeal fibrosis with recurrent bleeding.

Thorium dioxide, widely used as a contrast material, is a producer of alpha particle radiation. This is well demonstrated by autoradiography. The case described illustrates that life-threatening, thorium dioxide-induced pharyngeal haemorrhage may occur even with an occluded carotid artery. The radiation exposure caused an intense foreign body reaction with a marked cell-deficient fibrosis. The alpha particles are well demonstrated by autoradiography. In addition, we were able to show a defect in the wall of the carotid artery due to the Thorotrast injection, which was closed by cell-depleted connective tissue. As the radioactivity of the nuclides of thorium dioxide peaks 30-40 years after its first application, the morbidity will increase and the disease has to be taken into careful consideration in head and neck tumour lesions.

Aneurysm↗
PubMed1988

Distribution of tissue polypeptide antigen (TPA) in normal mucosa, in colitis ulcerosa, in adenomas and in carcinomas of the human colorectum. An immunohistochemical study.

65 carcinomas with their normal resection margins, 30 adenomas of the colorectum, and also ulcerative colitis biopsies from 10 cases were analysed immunohistochemically for pattern and intensity of expression of Tissue Polypeptide Antigen (TPA). In normal colon, and in well- and moderately-differentiated carcinomas, a cell membrane type staining pattern was predominant. In ulcerative colitis, in carcinoma cell groups within mucus of mucinous carcinomas or in single cells at the invasion front of all grades of carcinomas, a strong cytoplasmic type staining pattern was found. The cytoplasmic pattern was also found in poorly differentiated carcinomas, but with weaker staining intensity. The relationship between staining intensity and pattern and carcinoma grade was significant, whereas a similar relationship with the Dukes stages was not significant.

Adenoma↗
PubMed1988

[Microvascular architecture of the all-layer free inferior abdominal wall flap].

The authors dissected all layers of the inferior abdominal wall to study the possibility of free transplantation to close combined skin and mucosal defects. They perfused these flaps with a special solution of lead oxide and gelatin (Rees and Taylor 1986). After fixation in formalin the flaps were dissected in their layers and radiographs of these were taken. Networks of small vessels, which originate in the inferior epigastric artery, were found preperitoneally in the deepest compartment, in the muscular compartment and, nourished by perforators via the ventral rectus fascia, epifascially and subdermally in the subcutaneous tissue. On this basis free microvascular transplantation of a full-thickness abdominal wall flap seems to be possible to close combined mucosal and cutaneous defects. To thin this flap the subcutaneous middle third could be removed taking care to protect the epifascial and subdermal plexus of vessels. An isolated pre- and peritoneal microvascular flap also seems to be possible.

Abdominal Muscles↗
PubMed1987

Fatal copper storage disease of the liver in a German infant resembling Indian childhood cirrhosis.

A female child of non-consanguineous, healthy German parents fell ill at the age of 7 months with a progressive liver disease leading to irreversible hepatic failure 3 months later. Histological examination revealed severe liver cell necrosis, excessive Mallory body formation and veno-occlusive-like changes associated with massive storage of copper, similar to Indian childhood cirrhosis (ICC). Chronic copper contamination of drinking water was the only detectable aetiological factor. The study illustrates that ICC most probably is an environmental disease, also occurring outside the Indian subcontinent, and is likely to be underdiagnosed in the Western world.

Child↗
PubMed1987

Improvement of endoscopic laser therapy in gastrointestinal ulcer bleeding by tissue infiltration. Basic experiments on the dog stomach in vivo.

The therapeutic effect of Nd-YAG laser coagulation in arterial ulcer bleeding seems to be improved by local epinephrine infiltration. The purpose of this animal study was to evaluate the safety of this new therapeutic modality. The effect of Nd-YAG laser on normal and on infiltrated gastric mucosa was compared in acute and chronic experiments on 14 beagle dogs. On exposed normal gastric wall, perforation time and power output were inversely correlated. The required energies are nearly constant at different power levels. After infiltration of sodium chloride as well as of epinephrine into the mucosa, however, perforation time increased four- to five-fold. Volumes of mucosa defects and of the coagulation zones were also lower after pretreatment by infiltration. The results encourage further clinical use of this new therapeutic approach.

Animals↗
PubMed1987

[Vascular ultrastructure of the scapular flap].

The authors dissected fourteen cadaveric scapular flaps to study isolated free fascial and subcutaneous tissue transfer. They perfused these flaps with a special solution of lead oxide and gelatin (Rees and Taylor 1986). After fixation in formaldehyde, the flaps were dissected in three layers and radiographs were made of these compartments. In the basal layer, which comprises 40% of the flap thickness, an epifascial network of small vessels was found. In the most superficial, subdermal compartment which makes up 30% of the flap, a similar network was found. Therefore, it should be possible to dissect isolated fasciocutaneous or deep subcutaneous microvascular flaps. To thin a scapular flap, the subcutaneous middle third should be removed to protect these plexus of vessels.

Arteries↗
PubMed1986

Relation between the frequency of colorectal adenoma and the serum cholesterol level.

Several investigators have reported an association between low serum cholesterol levels and an increased frequency of colorectal cancer. Because low cholesterol levels may be a result of an established cancer, we have investigated the relation between serum cholesterol levels and the frequency of colorectal adenomas, which are thought to be precursors of colon cancer. We prospectively studied 1083 consecutive patients who underwent colonoscopy (241 of whom were excluded because of malignant disease, chronic inflammatory bowel disease, familial polyposis, or partial colectomy). In the remaining 842 patients, analysis of covariance was performed to evaluate the contribution of serum cholesterol to the risk of colorectal adenoma. Serum cholesterol levels were significantly and positively associated with the frequency of colorectal adenoma in subjects of both sexes. After adjustment for age and body-mass index, this positive association remained significant between the top quintile and the lowest quintile for serum cholesterol, with regard to the total study group (odds ratio, 2.0; 95 percent confidence limits, 1.1 and 3.6) and men only (odds ratio, 2.2; 95 percent confidence limits, 1.0 and 4.8). We conclude that there is not an inverse correlation between serum cholesterol levels and the risk of colorectal adenomas; on the contrary, there appears to be a small positive association.

Adenoma↗