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Biomedical subjects

G Feifel

Publications and source records attributed to G Feifel.

At least 19 recordsLinked to original sources
PubMed1992

Distribution pattern of capillary and venular red blood cell velocity following ischemia-reperfusion in striated muscle.

Ischemia-reperfusion induced changes in distribution pattern of RBC-velocity of nutritive capillaries and postcapillary venules was analyzed in striated muscle using intravital fluorescence microscopy in awake hamsters. Four hours of ischemia to striated muscle contained in the dorsal skinfold preparation (n = 10) revealed a significant (p < 0.01) decrease of capillary, but only a slight decrease of mean venular RBC-velocity during the entire reperfusion period. However, analysis of distribution pattern of single values revealed a shift of the histograms to the left, including pronounced skewness as mean values approached zero. This characteristic phenomenon may be due to an increase of microvascular hematocrit and/or decrease in deformability of red blood cells during ischemia-reperfusion. Beside other factors, the impairment of flow properties and flow conditions of the blood may contribute to the development of microvascular reperfusion injury.

Animals↗
PubMed1992

Influence of cryopreservation on viability and nutritional microcirculation of islets of Langerhans.

Isolated pancreatic islets of Syrian golden hamsters were cryopreserved for 1 and 10 weeks, respectively. Following thawing islet mass was found more than 90%. Analysis of viability of these islets by dithizone staining revealed 94 +/- 4% (1 week cryopreservation) and 96 +/- 3% (10 weeks cryopreservation) positively stained islets. After implantation into dorsal skin-fold chambers of syngeneic animals, intravital fluorescence microscopy (5% FITC-dextran, i.v.) showed a regular microvascular network 10 days after implantation. The total diameter of the microvascular network was found similar in cryopreserved islets (day 10: 420.8 +/- 55.2 microns (1 week preservation) and 406.5 +/- 25.2 (10 weeks preservation)) as compared to non-preserved controls (day 10: 411.7 +/- 53.9 microns). Therefore we conclude that cryopreservation of hamster islet isografts for 1 and 10 weeks, respectively, does not alter viability as well as the potential for revascularization. Cryopreservation seems to be an adequate technique for long time storage prior to free transplantation.

Animals↗
PubMed1992

Endosonographic differentiation of mucosal and transmural nonspecific inflammatory bowel disease.

Thirty-seven patients with nonspecific inflammatory bowel disease were examined with an ultrasonic colonoscope and the inflammation classified as mucosal or transmural. Mucosal inflammation was characterized by preservation of the five-layer structure of the wall with thickening of the submucosa. Transmural inflammation was endosonographically defined as sectional interruption or loss of the five-layer structure. In 14 of the 37 patients a colectomy was performed. Examination of 3 of the 14 resected specimens revealed inflammation confined to the mucosa. This was consistent in all three cases with the preoperative endosonographic evaluation. Eleven of the 14 resected specimens showed sectional transmural inflammation. Ultrasonographically all of the 11 patients fulfilled the criteria for transmural inflammation, whereas endoscopic and microscopic signs were consistent with transmural inflammation in 9 of the 11. Endosonography of the colon enables definition of mucosal inflammation thus providing criteria for selection of patient for ileoanal pouch construction.

Colon↗
PubMed1992

Cryopreservation of islets of Langerhans does not affect angiogenesis and revascularization after free transplantation.

Cryopreservation of isolated islets of Langerhans will be a necessary procedure if pancreatic islet transplantation crosses the threshold for clinical treatment of diabetes mellitus. Although successful cryopreservation of rodent, canine, porcine and human islets has been documented in the past few years, little is known about the influence of the freeze-thaw procedure on the islet's potential to induce angiogenesis and revascularization, a process which is of crucial importance after free transplantation. We have analyzed the process of revascularization of 1- and 10-week-cryopreserved hamster islet isografts using intravital fluorescence microscopy. First signs of angiogenesis of cryopreserved islet grafts were observed on day 2 after transplantation, characterized by the protrusion of capillary sprouts. During the following days these sprouts formed a microvascular network, and revascularization was completed on day 10 after transplantation. Quantitative analysis of functional capillary density, capillary red blood cell velocity, capillary diameter and flow of individual capillaries did neither show differences between 1- and 10-week-cryopreserved islets, nor differences between cryopreserved islets and islets transplanted without cryopreservation were observed. From these results we conclude that cryopreservation of isolated pancreatic islet grafts is an adequate technique for long-term storage prior to transplantation.

Animals↗
PubMed1991

[Initial experiences with a new monoclonal antibody in diagnosis of malignant melanomas].

In a study of 17 patients with malignant melanomas in the extremities the sensitivity and specificity of a new monoclonal antibody directed at melanoma cells (BW 575, Behring) were investigated. The specificity was 100%, but the sensitivity 70%. In 3 cases known foci could not be detected. All nodular melanomas and their metastases were detected (9 patients). Repeated examination during the first 24 h after injection of the Tc-99m-marked antibody, and two-plane investigations made it possible to detect even small tumors less than 1 cm in diameter and subcutaneous lesions where the melanomas absorbed the antibodies. Due to its high specificity, the antibody seems to be a promising aid in deciding the operative strategy.

Adult↗
PubMed1991

[Limited surgical radicality in occult cancer of Vater's papilla].

Nine histologically proven benign adenomas of the papilla of Vater were consecutively treated by transduodenal full thickness excision and simultaneous staging of regional lymph nodes without severe postoperative complications. 4 patients had a small well differentiated (pT1 GIpN0) carcinoma, although there was neither macroscopically nor by frozen sections any suspicion of a malignant tumour. A more radical pancreatoduodenectomy was not carried out and the 4 patients are without tumour recurrence or metastases 1-8 years postoperatively.

Adenoma↗
PubMed1991

[Ileostomy--stabilization by stapler technique].

In order to prevent nipple-sliding of the everted small bowel, conventional Brooke ileostomies in 26 patients were stabilized on both sides of the mesentery by longitudinal rows of staples. There were no early complications. With respect to historical controls with unstapled ileostomies, late complications (retraction, prolapse) could be reduced from about 16 to 0% in a median observation time of 2 years. The ileostomies were stable in size and form and therefore appliances were facilitated.

Crohn Disease↗
PubMed1991

[Changes in cell-mediated immune reactions in Crohn's disease].

In a prospective study the effect on cell-mediated immunity (Mérieux-Multitest), nutritional state and parameters of inflammation was compared in conservatively (n = 21) and surgically (n = 20) treated patients with Crohn's disease. Before therapy both groups showed a significantly lower immune response compared with healthy controls. The therapeutical effect was similar in both groups concerning normalization of parameters of inflammation, CDAI and state of nutrition. In contrast, normalization of immune response in skin test was only observed after bowel resection, while conservatively treated patients remained in hyperergy. In conclusion, the impairment of the cell mediated immunity in Crohn's disease must be secondary. Excluding patients with steroid therapy there was no correlation between preoperative annergy or hyperergy and postoperative complications.

Adult↗
PubMed1991

[Endosonography of the rectum].

Endorectal ultrasound is proving to be a very accurate method for the preoperative staging of cancer. The tumor penetration depth is assessed with an accuracy of more than 90% for all T stages. The preoperative endosonographic evaluation of lymph nodes is superior to other imaging modalities, being more than 80% accurate in comparison to CT and lymphoscintigraphy. It is relatively easy to perform and inexpensive compared with other imaging modalities. It has proved its influence on decision making, selection for local therapy, planning of radiotherapy and reoperation of early tumor recurrencies.

Humans↗
PubMed1991

[Complete reconstruction of the natural anus in complicated rectal prolapse].

In a 44-year old woman a severe case of prolapse of the rectum was complicated by complete incontinence and rectal stenosis. Continence was restored by colo-anal anastomosis between an oral smooth-muscle-plasty and the anal skin introduced in a newly created anal canal by a distal voluntary muscle-plasty. The successfully applied one-stage technique in reestablishing non-voluntary and voluntary muscular continence is described in detail.

Adult↗
PubMed1990

[Mixing results of prospective and retrospective studies by objective decision analysis: evaluating probability by healthy human minds?].

The major shortcomings of formal decision analysis derive from the complexity of the clinical problem, behavioral qualities of the investigator and the method itself. It seems difficult to translate study results into a probability estimate for the problem in an individual patient. Therefore, probability assessments from the medical literature, one's own clinical experience and data sources should be combined. Decision analysis is not itself clinical reality but provides a model for thinking explicitly about the problem.

Clinical Competence↗
PubMed1979

[Sensitivity of the haemoccult test in colorectal tumours (author's transl)].

157 patients with histologically investigated colorectal tumours from 5 hospitals of the University of Munich were tested with the Haemoccult test. In 30 (35.7%) of 84 patients with malignancy of the colon and in 31 (58.5%) of 53 patients with adenomas or polyps the correctly performed test was negative. The test result showed no dependency on age or sex of the patient, nor on size, stage or localisation of the tumour. A problem-orientated history lowered the rate of false negative tests to 2.4%. The high rate of false negative results was not attributable to organisational or technical errors.

Adenoma↗
PubMed1979

[The insulin test].

Since its introduction through Hollander 30 years ago the interpretation of the value of the insulin test following vagotomy have been discussed. For the individual patient no correlation between the incidence of ulcer recurrence and the result of the insulin test has been found. In addition, the risk of hypoglycemia seems to be too high for diagnostic purposes. Therefore, to evaluate the outcome after vagotomy basal acid output, pentagastrin stimulated acid secretion and endoscopy are emphasized as reliable methods.

Endoscopy↗