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Biomedical subjects

A Knipper

Publications and source records attributed to A Knipper.

41 records · Page 3Linked to original sources

[Experimental study on the pathogenesis of anastomotic ulcers (author's transl)].

Various forms of operative duodenal exclusion with or without duodenogastric reflux were performed on 54 male Wistar rats. It was demonstrated that after duodenal exclusion with reflux peptic ulcers regularly occur at the site of anastomosis. Continuous reflux of bile and pancreatic secretion is the decisive factor in the development of ulcer at the anastomotic border between stomach and jejunum. Stasis in the excluded duodenum (syndrome of the afferent loop) promotes the ulcerogenic reflux effect. If there is no pylorus, reflux and stasis are potentiated to the highest incidence of ulcer (more than 90%). These results indicate that operations with duodenal exclusion and reflux (Billroth II) should be discontinued.

Animals↗

[A special closure system of the gastrointestinal tract of the rat (author's transl)].

As a result of animal experiments, morpho-histologic and surgical findings, the presence of a new closure system of the gastrointestinal tract is described. The mode of action is different from that of all the known muscle sphincters. It is found in the ascending colon of the rat and consists of a specially arranged and adjustable mucosal folds with aunique vascularisation. A functional unit which comosed of a pair of folds and a vascular plexus constitute the valvular mechanism. We, therefore, consider appropriate to call it the Angioplical Closure System. Surgical reversion of even a very small portion of the system causes a lethal ileus.

Ampulla of Vater↗

[Medium-term results in cement-free endoprosthetics: the Lord prosthesis].

In a clinical and radiological follow up 64 Lord-endoprostheses could be controlled after a meantime of 8.5 years. The positive judgement of the patients, which is caused by the reduction of pain, is in contrast to the poor improvement of gait and mobility. Radiological findings are suspicious for a higher rate of loosening of the cup and fractures of the shaft.

Activities of Daily Living↗

Haematopoietic transplant potential of unrelated and related cord blood: the first six years of the EUROCORD/NETCORD Bank Germany.

To date, human umbilical cord blood (CB) has been employed successfully in well over 1000 allogeneic (unrelated and sibling) stem cell transplantations. Because of primary limitations in volume and cell numbers, over 90% of these transplantations were performed in children. Therefore requests for well standardised cord blood units of high quality are now increasing constantly. Examination and standardisation of unrelated and related cord blood stem cell preparations and banking as well as their biological characterisation was already initiated in Düsseldorf in 1992. Hitherto a total of 3236 CB samples with a mean volume of 89 +/- 25 ml, a mean total number of nucleated cells (NC) of 10 +/- 5 x 10(8) and a mean number of CFU-GM of 6 +/- 5 x 10(5) have also been validated by haematological, immunological and microbiological criteria. In addition to that, 97 directed CB donations of siblings with a clinical indication have been characterised and banked along the same lines. All CB units were collected from the umbilical cord vein immediately after vaginal full term delivery or caesarean section, then frozen and stored in liquid nitrogen. 1940 CB units were stored unseparated, the other 1296 were volume reduced using Hetastarch (HES) with a mean recovery of 85 +/- 13% of the nucleated cells, 86 +/- 12% and 84 +/- 13% for CFC and CD34+ cells, respectively. Only 5.0 ml of a CB sample is required for routine laboratory testing as there are HLA-class I typing, HLA-class II typing by sequence specific oligonucleotide probes (PCR-SOP), ABO typing, sterility control, assessment of progenitor and stem cells by colony forming assays, and CD34+ status as well as certain viral infections such as CMV, Hepatitis B, C, HIV, Parvo B19 by PCR technology before releasing the CB unit for transplantation. For apparent viral infections, maternal sera obtained at birth were tested for HBsAg, anti-HBc, anti-HCV, -HAV-(IgG, IgM), -HIV-1-2, -EBV- (IgG, IgM), -HTLVI-II, -CMV (IgM, IgG), toxoplasmosis and syphilis. Within the last three years a total of 4860 preliminary searches and 680 extended unit reports were submitted to the CB bank Düsseldorf by fax or World Wide Web. So far 68 unrelated and 3 related CB units were delivered. From these 70 have been transplanted in 30 different transplant centres world-wide. Until now the evaluation of the first 53 unrelated CB-transplantations was performed together with the EUROCORD transplant registry. Three patients were excluded from the analysis, since they received an unrelated CB-transplant for non-engraftment after previous allotransplants. The median patient age of these 50 patients was 5.0 years (range 0.3-44), the median weight 18 kg (range 4-70 kg). The majority of the patients transplanted for malignancies (66%) suffered from ALL (n = 19), AML (n = 7), CML (n = 4) and lymphoma (n = 2) with two third (75%) in an intermediate (2nd CR) or advanced stage of disease (> 2nd CR); 13 patients had metabolic diseases and immunodeficiencies and three had aplastic anaemia. All CB samples as well as the patients' blood samples were typed in Düsseldorf for HLA-class I by serology confirmed by PCR-SSP and by high resolution DNA typing for HLA-DRB1 and HLA-DQB1 alleles. 96% of the 50 patients receiving unrelated CB were mismatched at one or more HLA-antigens. 41 of the 50 patients transplanted with unrelated CB from Düsseldorf were evaluable for engraftment with an overall engraftment rate of 83%. According to the defined criteria of EUROCORD, 9 of the 50 patients were not evaluable for engraftment, since they died before day 60. The present median follow-up time is 14 months (1.4-38). The Kaplan-Meier estimate of survival at one year is 42 percent. The three paediatric patients after sibling CB transplantations (ALL, amegakaryocytic thrombocytopenia and CML) are alive with a follow-up time of 350, 379 days and 531 days. (ABSTRACT TRUNCATED)

Adolescent↗