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Biomedical subjects

W Timmermann

Publications and source records attributed to W Timmermann.

At least 55 records · Page 3Linked to original sources
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

Helical CT cholangiography for the detection and localization of bile duct leakage.

OBJECTIVE: We describe the use of helical CT cholangiography or helical CT after administration of biliary i.v. contrast material to verify and localize bile duct leakage. CONCLUSION: Helical CT cholangiography revealed bile leaks in seven patients after penetrating trauma or liver or gallbladder surgery and excluded bile leaks in two patients with blunt liver trauma. Endoscopic retrograde cholangiography was performed in only one of seven patients with bile leakage and was avoided in an additional two patients in whom CT cholangiography excluded leakage. The method is a feasible, noninvasive tool for the detection and localization of bile leaks and may help avoid endoscopic retrograde cholangiography.

Adult↗
PubMed1999

[Arterial reconstruction in arteriopathic diabetic perforating ulcer--is it effective? Revascularization in diabetes mellitus and peripheral arterial occlusive disease].

OBJECTIVE: In the present study long-term patency and limb-salvage rates of femoro-distal bypasses were compared for patients suffering from PAOD stage III and IV with and without DM. METHODS: Between 1990 and 1994, some 192 femoro-crural bypass procedures were performed; 132 reconstructions were carried out on patients with PAOD, 60 bypasses on patients with PAOD and DM. The two groups did not differ significantly regarding age, gender and risk pattern. RESULTS: The comparison of the two groups showed a significant advantage for the diabetic patients regarding the limb-salvage rate. In both groups there was also a significant difference regarding patency in favour of the diabetics. CONCLUSION: Patients suffering from DM and PAOD profit from femoro-distal bypasses. An aggressive vasosurgical reconstructive therapy is indicated for these patients.

Aged↗
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↗
PubMed1998

Apoptosis of T lymphocytes in liver and/or small bowel allografts during tolerance induction.

BACKGROUND: Apoptosis of parenchymal cells has been described during allograft rejection. Immunologically privileged tissue in the mouse has been found to prevent rejection by initiating apoptosis of infiltrating lymphocytes. The aim of this study was to investigate whether apoptosis may play a role in T-cell regulation during rejection and subsequent tolerance induction after liver transplantation (LTx) and combined liver/small bowel transplantation (LSBTx). METHODS: LTx and LSBTx (Brown Norway-->Lewis) were performed without immunosuppression. Cell migration, activation, and apoptosis were investigated by means of sequential histology, immunohistochemistry, and the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling assay. Donor (Brown Norway) and third-party (Dark Agouti) cardiac allografts were transplanted into LSBTx recipients to determine specific tolerance. RESULTS: Transient acute cellular rejection occurred after LTx and LSBTx and was followed by specific tolerance. The kinetics of apoptosis were similar in liver allografts after LTx and LSBTx, but differed from the processes in small bowel allografts after LSBTx. Apoptosis of parenchymal cells in the grafted livers correlated directly with interleukin-2 receptor expression of the infiltrating T cells. During the late phase of rejection, a peak of apoptosis in the lymphocyte infiltrate was demonstrated, characterized as predominantly apoptotic CD8+ T lymphocytes. CONCLUSIONS: These results demonstrate that specific tolerance is achieved in both LTx and LSBTx after a transient rejection crisis. Apoptosis is involved in graft rejection and tolerance induction. Activation of T lymphocytes correlates with parenchymal cell apoptosis in the allograft. T-cell inactivation seems to result in apoptosis of cytotoxic T cells and tolerance, which appears to be unique to the liver allograft.

Animals↗
PubMed1998

[Selective immunosuppression with monoclonal antibodies against ICAM-1 and LFA-1 with FK 506 after experimental small intestine transplantation in the rat].

Prevention of allograft rejection remains a major problem after small bowel transplantation (SBT) and requires potent immunosuppressive regimens. In a variety of transplant models, e.g. liver or heart transplantation, the supplementary application of monoclonal antibodies (mabs) against adhesion molecules is effective in both prolonging graft survival and inducing long-term graft acceptance or tolerance in some cases. In this study anti ICAM-1 (1A29) and anti LFA-1 (WT1) mabs were used in combination with a subtherapeutic dose of FK 506 for 13 days after allogeneic SBT in the rat. The results of this study indicate that in contrast to the induction of allospecific tolerance after liver transplantation, the addition of anti ICAM-1 and/or of anti LFA-1 mabs after SBT reverses the FK 506 effect and results in early graft rejection. It has been shown that higher dosages of these mabs, given alone or in combination with CsA or FK 506, result in long-term survival of cardiac allografts in both, rats and mice [4-8]. Graft survival after pancreas transplantation is prolonged [6]. However, these negative therapeutic effects of the mabs 1A29 and WT1 after SBT have to be critically reevaluated and further analysed.

Animals↗
PubMed1998

Arterial reconstruction in diabetes and peripheral arterial occlusive disease: results in 192 patients.

OBJECTIVE: In the present study long-term patency and limb-salvage rates of femoro-distal bypasses were compared for patients with and without diabetes mellitus. METHODS: Between 1990 and 1994, some 192 femoro-crural bypass procedures were performed; 132 reconstructions were carried out on patients with peripheral arterial occlusive disease (PAOD), 60 bypasses on patients with PAOD and diabetes mellitus (DM). The two groups did not differ significantly regarding age, gender and risk pattern. RESULTS: The comparison of the two groups showed a significant advantage for the diabetic patients regarding the limb-salvage rate. In both groups there was also a significant difference regarding patency in favour of the diabetics. CONCLUSION: Patients suffering from diabetes and PAOD profit from femoro-distal bypasses. An aggressive vasosurgical reconstructive therapy is indicated for these patients.

Adolescent↗
PubMed1997

[Treatment of increased intracranial pressure in craniocerebral trauma].

The management of trauma patients with increased intracranial pressure is based on maintaining a normal "milieu interne", i.e. avoiding posttraumatic hypoxia and hypotension and applying specific treatment modalities, if indicated. If there are clinical signs of increased intracranial pressure or signs of cerebral edema in the CT scan, monitoring of intracranial pressure is indicated. ICP above 20 mmHg should be treated and the cerebral perfusion pressure should be maintained between 60 and 70 mmHg. Accepted treatment modalities of increased ICP are: 1) analgosedation, 2) head elevation, 3) hyperventilation, 4) osmotherapy, 5) barbiturate therapy, and 6) THAM (tris puffer).

Brain Edema↗
PubMed1997

[Effect of modern instrumental diagnosis on surgical indications for resection of colorectal liver metastases].

In order to select those patients with colorectal liver metastases who may have benefit from an operation, preoperative detection and localization of tumors in the liver is necessary. In this study, the specificity and sensitivity of a CT arterial portography and magnetic resonance imaging with contrast media was compared with the results of operative findings and intraoperative ultrasonography. The combination of both preoperative methods led to an accuracy rate of more than 90%, and all patients who underwent laparotomy were resected or treated with an arterial infusion port system. Negative laparotomies were excluded completely.

Colorectal Neoplasms↗
PubMed1996

[The risk of needle-stick-injuries during abdominal closure].

A randomized study is being presented, which compares closure of laparotomy with 2 different needles (sharp: HR48, blunt: HR48PP = protect point). Handling and glove perforation rate is to be compared. 400 gloves in 100 laparotomies have been tested. Slightly more effort was reported from the surgeon to perforate the fascia with the blunt needle, but there was also a significantly lower perforation rate in the glove of his non-dominant hand. To avoid a contamination during operation the use of blunt needles has to be recommended.

Abdomen↗
PubMed1995

[Combined liver-islet transplantation after epigastric exenteration in carcinoma of Vater's ampulla].

A 44 year old female underwent an upper abdominal exenteration because of an adenocarcinoma of the pancreas with liver metastases (T1 N1 M1). Reconstruction was performed by orthotopic liver transplantation and intraportal islet transplantation. Due to initial non function of the first liver graft, a second liver transplantation was performed. Thereafter, the patient received 375,000 islet equivalents of the primary liver donor in addition to 295,400 islet equivalents of another donor. Six months postoperatively, the patient is off insulin except irregular injections of 4-6 units of insulin to protect her from hyperglycemia after lunch. CT scans of the liver do not show any signs of tumor recurrence. Upper abdominal exenteration with consecutive islet transplantation offers a good method of reconstruction after radical surgery in the upper abdomen. The oncological aspects of the procedure have to be further investigated.

Adenocarcinoma↗
PubMed1995

[Is ion-selective measurement of the liver surface for detection of cell damage suitable?--A study of the rat liver transplantation model].

UNLABELLED: Aim of the study is to detect a reperfusion injury in rat liver transplantation by the Ion-selective Surface-Measurement (OMS). METHODS: Lewis rats served as models for 30 liver transplantations with 1, 6 or 12 hrs of cold ischemia respectively. Directly before, during and after transplantation potassium- and hydrogen-concentrations were measured with the OMS and compared to transaminase values on day 1, 3 and 7 as well as to biopsies on day 3. RESULTS: Transaminase values and histology show ischemic cell injuries correlating to the length of ischemia, whereas potassium- and hydrogen-concentrations on the organ surface do not. CONCLUSIONS: Ischemic cell injury in the rat liver cannot be detected by the Ion-selective Measurement.

Acid-Base Equilibrium↗