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Biomedical subjects

G Staehler

Publications and source records attributed to G Staehler.

At least 73 records · Page 4Linked to original sources

Extracorporeal shock wave treatment raises blood pressure in borderline hypertensive rats.

The long-term sequelae on kidney function and blood pressure of renal shock wave treatment were studied in normotensive Wistar rats, contralaterally nephrectomized Wistar rats and borderline hypertensive F1-hybrids bred from stroke-prone spontaneously hypertensive rats and Wistar-Kyoto rats. Renal shock wave treatment raised arterial blood pressure in borderline hypertensive, but not in normotensive, rats. A concomitant impairment of ipsilateral renal function or perfusion was not seen despite macroscopic and microscopic evidence of a loss of functioning parenchyma. We conclude that extracorporeal shock wave treatment, by way of its detrimental effects on the kidney, has the potential to provoke arterial hypertension in rats, provided that a genetic predisposition exists.

Animals↗

[Spontaneous kidney ruptures--a complication of panarteritis nodosa].

Besides renal cell carcinomas and angiomyolipomas panarteritis nodosa (PAN) is a common underlying disorder for spontaneous perirenal hematomas (SPH). Herein we report on 3 cases with PAN associated kidney ruptures where diagnosis of PAN was not known before in 2 instances. The hematoma was identified by computerized tomography (CT) in all patients, nevertheless CT failed to reveal the underlying disorder in any case. In this situation angiography was extremely valuable visualizing multiple renal microaneurysms that are typical for PAN. Operative exploration and drainage of the hematoma was necessary in two patients because of hemodynamic instability. In one patient bleeding could be controlled after an immediate immunosuppressive therapy with prednisone and cyclophosphamide. Due to the high incidence of PAN associated spontaneous perirenal hematomas angiography should be performed in all cases with unclear SPH after CT evaluation. In our opinion an immediate surgical intervention is only indicated in cases with hemodynamic instability. Otherwise a conservative approach including immediate immunosuppression seems justified. Nephrectomy should be avoided whenever possible.

Adolescent↗

IL-6 independent monocyte/B cell defect in renal transplant recipients with long-term stable graft function.

We showed previously that the B cell response in renal transplant recipients with long-term stable graft function (ST patients) is significantly affected by T suppressor activity. To further assess the role of the monocyte/B cell compartment in B cell regulation, we tested B cell responses in 30 ST patients (> 1 year after transplant) and 15 patients with chronic rejection (CR patients). PWM was used for T cell-dependent B cell stimulation in an allogeneic coculture system, and SAC I for T cell- and monocyte-independent B cell stimulation. B cell responses were assessed in a reverse hemolytic plaque assay and by ELISA determination of IgM, IgG, and IL-6 in culture supernatants. In PWM-stimulated cultures of ST patients, we found a diminished immunoglobulin-secreting cell (ISC) formation (P < 0.0001 and P < 0.05, compared with controls and CR patients, respectively) and diminished IgM secretion (P = 0.06 and P < 0.01, respectively), whereas CR patients and controls were not significantly different. Two of 35 (6%) controls and 3 of 15 (20%) CR patients, in contrast to 20 of 30 (67%) ST patients, displayed defective ISC formation (P < 0.0001). This defective B cell response may be the result of reduced CD36+ monocyte counts in ST patients (P < 0.005), as PWM-stimulated B cell responses and CD36+ cell counts were significantly associated (P < 0.05, ISC and IgM response). A role of monocytes in the impairment of B cell function is further supported by decreased plasma neopterin levels in ST compared with CR patients (P = 0.0001), a significant association between plasma neopterin and PWM-stimulated B cell responses (P < 0.05, ISC response; P = 0.0001, IgM response), and by the finding that B cell responses in ST patients after monocyte-independent stimulation with SAC I were unaffected. ST and CR patients showed no significant differences in B cell subsets, plasma IL-6, or IL-6 responses of mitogen-stimulated cultures. Our data indicate that an IL-6-independent monocyte or B cell defect plays a role in the maintenance of stable transplant function.

Adult↗

Prolongation of discordant renal xenograft survival by depletion of complement. Comparative effects of systemically administered cobra venom factor and soluble complement receptor type 1 in a guinea-pig to rat model.

There is an increasing body of evidence to suggest that inhibition of complement activation may be a valuable approach to avert hyperacute rejection. In our study, the guinea-pig to rat discordant kidney xenograft model was adapted for the investigation of renal transplant function and an attempt was made to delay the hyperacute rejection using systemically administered cobra venom factor (CVF) and soluble complement receptor type 1 (sCR1). The saline-treated control recipients experienced a rapid transplant rejection with a xenograft survival averaging 10.5 +/- 2.1 min. Administration of a single 60 U/kg i.v. bolus of CVF significantly prolonged renal graft survival to 20.4 +/- 2.5 h, and by a single bolus of sCR1 (50 mg/kg) a prolongation of graft survival to 18.8 +/- 2.3 h was achieved. The grafts functioned only over periods of 2.5 +/- 0.3 and 2.3 +/- 0.2 h, respectively. No complications of sCR1 were noted. We concluded that complement inhibition by sCR1 may be an important component in the therapeutic approach aiming at the prevention of hyperacute rejection in human organ transplantation.

Animals↗

[The value of diagnostic imaging in benign prostatic hyperplasia and prostatic cancer].

Diseases of the prostate are of high socioeconomic importance owing to their high incidence and prevalence rates. Benign prostatic hyperplasia (BPH) can be detected in 80% of males over the age of 80. Clinical symptoms do not correlate with organ enlargement. Only 10% of patients with BPH need surgical treatment. The decision for surgical treatment is made as a result of objective findings and the symptoms reported by the patient. Preoperative evaluation of BPH must include digital rectal examination (DRE), measurement of peak flow rate, sonographic estimation of residual urine, transrectal ultrasound (TRUS), urethrocystography and the assessment of subjective complaints using symptom scores. Prostatic carcinoma is the most common malignancy in men. An abnormal DRE, increased PSA level and/or hypoechogenic lesions in TRUS are indications for prostate biopsy. The sensitivity of TRUS is superior to that of CT and MRI. New MRI techniques are promising with regard to local tumour extent. Whereas CT and MRI are not useful in screening of patients, these methods are valuable diagnostic tools in the follow-up of prostate cancer.

Humans↗

[Kidney transplantation in children].

Renal transplantation has become an established form of therapy for children with endstage renal disease. Evaluation and elimination of potential risk factors, standardization of operative technique and better immunosuppressive regimens improved the outcome in paediatric patients. A shortage or organs means that transplantations cannot always be offered to children for whom it would be the treatment of choice. Kidney donation by living relatives opens up the potential for optimal rehabilitation of patients in the paediatric age group.

Adolescent↗

[Separation of urological tumor cells by means of a cell saver combined with a membrane filter. A new technique for autotransfusion?].

Three long duration cancer cell lines were marked with radioactive methionine S and mixed with a defined quantity of concentrated red cells. The mixture was separated according to a standardized method with cell saver and two membrane filters. The marked cancer cells were counted with a liquid scintillation cell counter. After separation, only 0.027% of the initial radioactivity was retrieved. If this result can be confirmed in a clinical setting, this technique would be highly promising for intraoperative automatic autotransfusions, especially in the field of tumour surgery. Despite the quality of conserved blood, heterotransfusion still involves considerable risk for the receiver.

Blood Transfusion, Autologous↗

[Local recurrence after organ saving kidney tumor surgery].

Although excellent survival rates for nephron-sparing surgery in mandatory indications (solitary kidney, bilateral renal neoplasms) have been documented, parenchymasparing surgery in elective indications (normal contralateral kidney) is a point of controversy. Local tumor recurrence is the most important argument against this approach. From January 1971 to December 1989, 107 patients suffering from renal cell carcinoma in solitary kidneys or bilateral renal carcinoma underwent nephron-sparing surgery. Thirteen patients (12%) suffered from local recurrence between 4 and 112 months after tumor resection. A high proportion of these recurrences were seen within the first 2 years after resection, followed by a almost linear increase thereafter. Thus-there are possibly two different entities for local recurrence. A correlation between tumor grade and interval from resection to local recurrence could be found, with a long average interval for grade 1 tumors--longer than the published follow-up times for patients undergoing elective tumor resections. Although most of the patients described in this report do not fulfil the surgical criteria for elective resection, we cannot recommend parenchyma-sparing surgery in elective indications.

Adult↗

[Intraoperative electron irradiation (IORT) of urologic tumors. Initial results of a pilot study of local recurrences of renal cell cancers].

The efficacy of radiotherapy of renal cell carcinomas is limited by its side effects. To avoid gastrointestinal problems the dose must not exceed 45 Gy, but with corresponding protocols no effect has been seen in curative and adjuvant trials. A new three-step protocol combining surgery with intraoperative radiotherapy focussed on the tumor bed fading out the intestine (IORT) and external boost radiotherapy (40 Gy) was used in six patients with local recurrences after tumor nephrectomy. No increase in morbidity was induced by IORT. One year after radiotherapy no recurrences have been seen in the radiation field. We recommend this protocol for patients with solitary local recurrences and for tumors of clinical stage T3 and T4.

Adult↗

[Tumor involvement of the vena cava in renal cell carcinoma. Surgical technique, results and prognosis].

In 45 patients with a vena cava tumor thrombus secondary to renal cell carcinoma we present the diagnostic and operative management and relevant data on the extent of the thrombus (classified into 4 stages), postoperative complications and patient survival. Extensive thrombi of the vena cava were removed surgically in hypothermia and with extracorporeal circulation. The importance of an interdisciplinary approach involving cardiac and urologic surgeons is therefore emphasized. With due consideration for relevant prognostic parameters such as tumor differentiation or spread, we estimated a 5-year survival of 29% for our Heidelberg patients. Neither the extent of the tumor thrombus nor tumor infiltration of the perirenal adipose tissue had any influence on patient survival.

Adult↗

[Effect of intraoperative fibrin gluing on lymph flow and lymphocele formation after kidney transplantation].

In a randomized prospective study we examined 100 renal transplant patients including 20 children, to test the hypothesis that intraoperative application of clotting factors (in the form of fibrin glue) reduces the postoperative lymph flow and the frequency of lymphocele formation. The study showed that the use of fibrin glue during renal transplantation did not reduce the postoperative production of drainage fluid or lymphocele formation. The postoperative lymph flow was not related to the formation of lymphoceles. In adults the use of higher doses of immunosuppressants seems to increase the risk of lymphocele formation. On the other hand children have a very low rate of lymphocele formation even when high doses of immunosuppressants are used. The postoperative lymph has a constant composition of erythrocytes and leucocytes. The plasma protein extravasation decreased postoperatively and was influenced by the plasma protein content. From these results we conclude that the postoperative frequency of lymphocele formation cannot be reduced by intraoperative use of fibrin glue in the chosen protocol.

Adolescent↗