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Biomedical subjects

A Thiede

Publications and source records attributed to A Thiede.

At least 109 records · Page 6Linked to original sources
PubMed2000

[The role of growth factors in wound healing].

Growth factors are mediators with essential importance for undisturbed repair process after wounding. The well coordinated concert of these substances is necessary for healing with complete restoration of function and morphology. These complex mechanisms are disturbed during secondary and delayed repair. The result is protracted healing course and inferior scar quality--either hypo- or hypertrophic. Local and systemic application of these growth factors seems to add important instruments for therapeutic use in the treatment of chronic wounds. Knowledge from experimental research is encouraging, although the exact mechanisms of synergistic action are not completely understood. However, the results from clinical use in controlled studies do not meet these expectations by far. The main reasons for this dilemma are thought to be little understanding in the complex interactions of these substances. In fact, different wound entities seem to reveal different cytokine profiles during the course of repair. Further intensive research therefore is required for the rational use of growth factors in the clinical setting.

Animals↗
PubMed2000

[Ambulant treatment of wounds by vacuum sealing].

The treatment of chronic wounds by vacuum sealing as an outpatient procedure is a new method of wound conditioning before closing the defect. The quality of life for the patient in his usual surrounding is maintained. Financial aspects also play a role in this treatment since costs for the health care system can be reduced. Various vacuum pumps, drainages and polymere foams are available and suitable for the outpatient treatment. The most important condition is to regularly check the vacuum. This can performed by the patient, the relatives or nursing staff. The main complication consists in loss of vacuum but technical and local or systemic complications can also appear. Individually applied vacuum dressings (polyvinyl foam, drainage tube and polymere foil) are practical. The ideal pump systems for the outpatient treatment are still not trial.

Ambulatory Care↗
PubMed1999

Videomicroscopic imaging of graft mucosa for monitoring immunosuppressive therapy after small intestinal transplantation in rats.

BACKGROUND: Early diagnosis of rejection and effective immunosuppressive treatment are essential after small intestinal transplantation. To date little is known about microscopic alterations of the intestinal mucosa of the graft during rejection. We attempted to determine whether videomicroscopic imaging of the graft mucosa is a suitable method for monitoring immunosuppressive therapy. METHODS: Real-time videomicroscopic imaging of an ileostoma was performed daily after allogeneic heterotopic small bowel transplantation in the rat (BN to LEW) with and without FK506 immunosuppression. Subsequently, the videomicroscopic findings were compared with the histologically determined grade of rejection. RESULTS: A semiquantitative staging system was established for the intravital mucosal changes during graft rejection. The earliest changes related to rejection appeared on POD 6 in the untreated allogeneic group. The mucosa developed patchy paleness and the mucosal architecture was interrupted in places. The crypts were slightly widened and their color turned dark red (stage I). These alterations spread progressively over the mucosa on POD 7 (stage II). On POD 9 the mucosa appeared pale, the villi were shortened, and the crypts appeared wide and rounded (stage III). In the animals treated with FK506 similar changes were observed, but with a delayed onset. When FK506 was administered as antirejection therapy at the onset of rejection, a temporary improvement of mucosal alterations was observed (stage II --> stage I). The video-microscopic stages correlated with the histological grade of rejection. CONCLUSIONS: The introduction of videomicroscopy has made computer-based high resolution imaging of mucosal microarchitecture possible. With videomi-croscopy beginning rejection can be detected, although it can still be reversed with antirejection therapy. This is a new noninvasive technique that might be of high clinical relevance.

Acute Disease↗
PubMed1999

Noninvasive videomicroscopic monitoring of rat small-bowel rejection.

Successful small-bowel transplantation requires an early diagnosis of graft rejection. To date, little is known about macroscopic mucosal alterations during rejection. In the present study, these changes were analyzed in detail. Videomicroscopic monitoring of an enterostoma was performed after allogeneic heterotopic small-bowel transplantation in the rat (BN to LEW). Up to postoperative day (POD) 3 a mucosal edema was noticed (stage I of videomicroscopical alterations). The earliest changes related to rejection appeared on POD 6. The mucosa of the grafted intestine developed patchy paleness and interruptions in mucosal architecture. Crypts were slightly widened and their color turned to dark red (stage IIa). Progressively, these alterations spread over the mucosa on POD 7 (stage IIb). On POD 9, the mucosa appeared pale, villi were shortened, and crypts appeared wide and rounded. The mucosal surface was coated with fibrinous membranes (stage III). The videomicroscopic findings were closely related to the histological grading of rejection. We regard this technique of mucosal monitoring a simple and noninvasive method of detecting allograft rejection.

Animals↗
PubMed1999

Comparison of different J-pouches vs. straight and side-to-end coloanal anastomoses: experimental study in pigs.

PURPOSE: Functional results after low anterior resection with straight coloanal anastomosis are poor. Although certain functional aspects are improved with coloanal J-pouch anastomosis, evacuation difficulties are encountered in some of these patients. The aim of the study was to investigate the functional results of different reconstruction methods after low anterior resection in a standardized pig model. METHODS: Thirty-two adult Göttinger mini pigs were randomly assigned either to straight end-to-end (Group 1), side-to-end (Group 2), small (4-cm limb length) J-pouch (Group 3), or large (8-cm limb length) J-pouch (Group 4) coloanal anastomosis after low rectal excision. The animals were investigated 12 weeks after the operation by measuring neorectal compliance and ceruletide-induced defecation. Eight pigs without operation were used as controls (Group 5). RESULTS: Compliance was lowest in Groups 1 and 2, which were significantly different compared with both pouch designs and controls. Neorectal compliance of pigs with either small or large pouches did not differ significantly compared with one another or controls. Defecation was significantly impaired in pigs with a large pouch compared with all other groups. Pigs with side-to-end anastomoses had as rapid an evacuation as animals with straight coloanal reconstruction. CONCLUSION: Coloanal J-pouch reconstruction adequately restores reservoir capacity after low anterior resection of the rectum. From a functional point of view, side-to-end is not superior to straight coloanal anastomosis. Compared with small pouches, a large pouch design does not lead to better neorectal compliance in the pig model, whereas pouch evacuation seems to be considerably compromised.

Anal Canal↗
PubMed1999

Curative-intent radiation therapy in anal carcinoma: quality of life and sphincter function.

In 22 colostomy-free survivors of curative-intent radiation therapy or chemoradiation for anal carcinoma, measurement of the Gastrointestinal Quality of Life Index (GIQLI) revealed a mean 114 of a maximum 144 points, as compared to 121 in healthy volunteers (n = 150) and 113 in patients with benign anorectal diseases (n = 325). Sixteen patients underwent anorectal manometry to determine anal sphincter length (SL), resting pressure (RP), maximum squeeze pressure (MSP), rectal compliance (RC) and relaxation of the internal anal sphincter (RIAS). SL, RP and MSP were significantly lower in anal carcinoma patients than in healthy volunteers. Complete continence was detected in 56% of patients.

Adult↗
PubMed1999

Long-term results after 75 anastomoses in the upper extraperitoneal rectum with the biofragmentable anastomosis ring.

BACKGROUND: Anastomoses in the rectum have a higher risk for complications compared with other gastrointestinal regions. Stapling devices and sophisticated developments in surgical suture materials did not lead to a substantial decrease of local complications. The bioabsorbable anastomosis ring (BAR) is a new alternative technique for creating gastrointestinal anastomoses. Accordingly, the aim of this prospective study was to evaluate the postoperative course and long-term results of patients after anterior rectum resection using BAR. METHODS: From 1991 to 1996 75 BAR anastomoses were performed in the upper rectum at the Department of Surgery, University Hospital Würzburg. Thirty-eight patients suffered from malignant, 37 from benign disease. Mean age was 61.4 years with no relevant differences in the gender. Mean follow-up was 31 months (4-63 months). The clinical course was evaluated, a questionnaire completed and/or a 3-monthly reevaluation with endoscopy conducted. Mortality, anastomostic bleeding, leakage and development of anastomotic stenosis were evaluated. RESULTS: Sixty-seven patients could be reexamined. There was no postoperative mortality and no anastomotic bleeding. Six patients (8%) developed an anastomotic leakage, of whom 3 (4%) required reoperation. None of the patients revealed a detectable stenosis in the anastomotic region during follow-up. CONCLUSION: The BAR procedure is a safe and suitable anastomotic technique after anterior rectum resection.

Absorbable Implants↗
PubMed1999

[Transplantation of porcine Langerhans islets for therapy of type I diabetes. The way to clinical application].

Transplantation of isolated pancreatic islets provides an interesting alternative to the present cure for diabetes: insulin injections and pumps. These are characterized by an insufficient glucose haemostasis and in the long run can induce kidney failure, blindness, heart failure, and amputations. Up to now more than 293 allogeneic islet transplantations have been performed in diabetics with chronical kidney failure. Despite some success, no real breakthrough has been yet achieved, though great efforts are being made to improve the various methodological steps on the way to clinical transplantation. The use of animal (xenogeneic) organs could be a solution to overcome the shortage of allogeneic donors. The current experimental and clinical research focuses on the use of pigs as organ donors, which have a number of advantages over the immunologically more compatible primates. This article reports on success and open questions concerning the efforts to isolate porcine islets for future clinical transplantation: the search for a suitable pig breed, the various isolation steps, purification and in vitro culture, transplantation models using-small and large animals, first clinical trials, and immunological reactions against the xenogeneic tissue. In addition, strategies to circumvent tissue rejection and future perspectives are discussed.

Alginates↗
PubMed1999

[From Murphy's button to the Valtrac Ring. 100 years in search of a paradigm].

In the context of continuous development in the area of anastomotic sutures leading to exceptional results in surgical practice, the biofragmentable anastomosis ring (BAR) described in 1985 by Hardy et al. represents a breakthrough in a 100 years' search of a paradigm. The first anastomotic button created in 1892 by J.B. Murphy was at once accepted as a quick and safe method of intestinal anastomosis. In 1896 Czerny demanded the following: "The task of technology is ... to create buttons with material that is entirely or partly dissolved in the intestinal lumen." Polyglycolic acid--developed in the sixties and now in widespread use for resorbable surgical sutures--was the material to fulfill the requirements already stated in the relevant literature 100 years ago, namely in the form of Hardy's BAR, which represents a redesigned Murphy button exploiting the recent biotechnological developments of this century.

Anastomosis, Surgical↗
PubMed1999

[Possible enterostomy techniques].

Various techniques for colostomies and ileostomies have been described using both conventional and laparoscopic surgical techniques. The stoma should be placed in a lower quadrant of the abdomen through the rectus muscle below the umbilicus to be cared for properly. The support of an enterostomy therapist may be helpful for the patient.

Colostomy↗
PubMed1999

[Functional diagnosis of pelvic floor insufficiency--consequences for surgery].

Functional tests allow for the qualification and quantification of underlying function defects in the diagnosis of pelvic floor incompetence. However, the results of these instrumental investigations alone do not suffice for a therapeutic decision. The decision for a surgical therapy should therefore always be based on the clinical presentation, the extent of subjective impairment, and the degree of the causative pathophysiologic defect detected in the function tests.

Fecal Incontinence↗
PubMed1999

[Endosonographic imaging of anal fistulas in infants].

Anorectal endosonography is established as a diagnostic tool in anorectal fistulas, today. Yet, there is still little experience with the use of this method in small children. We could visualize three intershincteric fistulas in children at an age of 6, 7 and 14 months. The procedure is well tolerated and even children under the age of one year can be examined with a special probe.

Contrast Media↗
PubMed1999

[Open surgical therapy of constipation].

This paper reviews diagnostic criteria, indications, and selection criteria for surgical therapy in chronic constipation. Special emphasis is laid on surgical therapy of pelvic outlet obstruction. Colonic resection may be considered as last surgical resort in those few cases where conventional therapeutic measures have been exhausted and an extensive diagnostic protocol based on clearly defined criteria has been followed. This may offer a justifiable therapeutic alternative only in cases where highly symptomatic and refractory colonic inertia (slow transit constipation) is confirmed, and associated outlet obstruction has been excluded.

Chronic Disease↗
PubMed1999

[Billroth I anastomosis with biodegradable anastomosis ring in the animal model].

In the present study, the Billroth-I anastomosis with the biofragmentable anastomosis ring was examined in dogs. 24 dogs were randomized into a group of manual suturing (n = 12) and a BAR-group (n = 12). In the group of manual suturing, a distal gastric resection and gastroduodenostomy with sero-submucous suture was performed. In the BAR-group, the distal gastric resection was done with the linear stapler PLC-75, whereby the BAR gastroduodenostomy crossed the stapling line. The dogs were evaluated on p.o. days 4, 14, and 30 and tested for bursting strength and bursting location, appearance of mucosa, hydroxyprolin concentration, and histologic features. There was no functional disorder in the gastrointestinal transit in any animal; in summary with regard to the various parameters, the crossing of BAR and stapling line does not represent any additional risk factor in the Billroth-I anastomosis in dogs.

Anastomosis, Surgical↗