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C Doehn

Publications and source records attributed to C Doehn.

54 records · Page 3Linked to original sources

Treatment of posttransplant hypertension by laparoscopic bilateral nephrectomy?

BACKGROUND: Hypertension is an important risk factor for the development of chronic graft failure and decreased graft and patient survival after renal transplantation. METHODS: Between September 1994 and August 1996, 14 patients underwent laparoscopic bilateral nephrectomy for treatment of drug-resistant hypertension after successful renal transplantation. Common causes of hypertension were largely excluded before bilateral nephrectomy. A scoring system was developed for comparison of different antihypertensive regimes. In this system, points were given according to type and dosage of each antihypertensive drug. RESULTS: At 6-month follow-up, all patients showed well-controlled blood pressure (median of mean arterial pressure: 104 vs. 130 mmHg preoperatively, P<0.001, n=14), and significantly fewer antihypertensive drugs were needed according to the scoring system (48.9+/-20.9 points vs. 105.9+/-23.5 points preoperatively, P<0.001, n=14). During laparoscopy, three conversions to open surgery were necessary. Postoperatively, four complications occurred. After laparoscopy, immunosuppression and other oral medication were given continuously. The hospital stay ranged between 3 and 6 days (median: 5 days). CONCLUSIONS: The results indicate that bilateral nephrectomy using the laparoscopic technique can be an effective alternative method for a selected group of patients with severe hypertension, which is unresponsive to conservative management after successful renal transplantation with regard to improving the long-term graft survival.

Adult↗

Laparoscopic nephrectomy: comparison of dialysis and non-dialysis patients.

BACKGROUND: Laparoscopy is believed to result in possible clinical benefits for the patient. We report our experience with renal laparoscopy in dialysis patients and compare the results with those from non-dialysis patients. METHODS: Between December 1994 and April 1997, 19 dialysis patients underwent laparoscopic nephrectomy or nephroureterectomy at our hospital. The group consisted of 11 female and eight male patients (mean age 45 years). In nine patients the indication for nephrectomy was chronic pyelonephritis. Nephroureterectomy for vesicoureteral reflux with recurrent episodes of pyelonephritis or analgesic nephropathy for exclusion of transitional cell carcinoma of the upper urinary tract was considered in nine other patients. Laparoscopic bilateral nephrectomy for drug-resistant hypertension was performed in one patient. In comparison, a consecutive group of non-dialysis patients who had undergone renal laparoscopy was reviewed. RESULTS: In the dialysis group, one patient had to be converted to open nephrectomy due to bleeding. Six dialysis patients required blood transfusions compared with none in the non-dialysis group. There were four complications in the dialysis group and two in the non-dialysis group. Both groups had comparable results for operative times, analgesic consumption, postoperative start of oral intake and mobilization, and duration of hospitalization and convalescence. CONCLUSIONS: Laparoscopic nephrectomy in dialysis patients has acceptable results. The higher transfusion rate is probably due to a lower preoperative haemoglobin and is not aggravated by possible affects of the clotting system in patients with chronic uraemia.

Adult↗

Comparison of laparoscopic and open nephroureterectomy for benign disease.

PURPOSE: We report our experience with laparoscopic nephroureterectomy for benign disease and compare the results to a contemporary group of patients undergoing open nephroureterectomy. MATERIALS AND METHODS: Between October 1994 and March 1997, 12 women and 4 men with a mean age of 50 years (range 22 to 70) underwent laparoscopic nephroureterectomy at our hospital. Indications for operation were nonfunctioning kidneys due to vesicoureteral reflux with recurrent episodes of pyelonephritis or analgesic nephropathy before a planned renal transplantation. In comparison 11 women and 4 men with a mean age of 40 years (range 18 to 64) underwent open nephroureterectomy for various benign diseases. RESULTS: Laparoscopic and open nephroureterectomy had no significant differences regarding operative times (100 versus 124 minutes) and complication rates (25 versus 20%). In the laparoscopy group conversion to open surgery was not necessary. Patients who underwent laparoscopic nephroureterectomy had significantly less consumption of morphine equivalent for postoperative pain control (12 versus 40 mg.), shorter time to achieve mobilization and oral intake (11 versus 39 hours), shorter hospital stay (6 versus 12.7 days) and faster return to normal activities (21 versus 39 days). CONCLUSIONS: Laparoscopic nephroureterectomy in patients with benign disease has similar operative results but obvious postoperative advantages compared to the open approach.

Adolescent↗

Treatment of recurrent penile condylomata acuminata with external application and intraurethral instillation of bacillus Calmette-Guerin.

PURPOSE: Condylomata acuminata are caused by human papillomavirus infection. Despite numerous treatment modalities these patients often demonstrate recurrent disease. We report initial experience with bacillus Calmette-Guerin (BCG) therapy in patients not responding to standard treatment. MATERIALS AND METHODS: Between October 1994 and March 1997, 6 men with rapidly recurrent external and intraurethral condylomata acuminata underwent BCG therapy after initial laser treatment. External application and intraurethral instillation of BCG were performed 6 times in weekly intervals. Followup studies included examination and endoscopic inspection of the urethra and bladder. RESULTS: Of the patients 3 completed 1 course of BCG and had no relapse of condylomata acuminata, 2 underwent a second course of BCG and 1 had relapse, and 1 had relapse after discontinuing therapy due to penile edema. The annual recurrence rate decreased from 3.2 before to 0.75 after BCG therapy (p < 0.05, test of equality of 2 percentages). CONCLUSIONS: Immunotherapy with BCG is accepted treatment for superficial transitional cell carcinoma. The BCG induced immune response appears to reduce the recurrence rate in patients with condylomata acuminata.

Adjuvants, Immunologic↗

Laparoscopic nephropexy: 3-year experience.

PURPOSE: Operative treatment of nephroptosis is rarely performed and is indicated only in select patients. Postoperatively approach related symptoms and morbidity often limit therapeutic success. We evaluated the technique and outcome of laparoscopic nephropexy in patients with symptomatic nephroptosis. For comparison the records of patients who underwent open nephropexy were reviewed. MATERIALS AND METHODS: Since 1993, 22 women and 1 man 16 to 56 years old (mean age 29) underwent laparoscopic nephropexy at our hospital. Preoperatively excretory urography and radioisotope renography were performed with the patient supine and erect, and careful pain evaluation was also done. For laparoscopic nephropexy the transperitoneal approach was used in all patients. The kidney was completely mobilized by dissection of the perirenal fat. The upper pole and convexity of the kidney were fixed to the muscle using single nonabsorbable sutures and an extracorporeal technique for tying. Between 1984 and 1994, 12 patients underwent open nephropexy at our hospital. The results of this group were reviewed and compared with those treated by laparoscopy. RESULTS: Mean operative time in the laparoscopy and control groups was 61 (range 40 to 85) and 49 minutes (range 28 to 70), respectively. In patients who underwent laparoscopic nephropexy mean analgesic use was 15 mg. morphine equivalent intravenously and 550 mg. ibuprofen orally. Postoperatively 3 minor complications (13%) were noted. Hospital stay was 3.7 days (range 2 to 9) and patients returned to work after 19 days (range 4 to 30). Six weeks after nephropexy excretory urography showed a correctly positioned kidney. At a mean 13-month followup pain intensity had improved in 21 patients (91%). According to these parameters laparoscopic nephropexy was superior to the open approach except for operative time. CONCLUSIONS: Laparoscopic nephropexy is safe and effective in the select group of patients in whom nephropexy is indicated.

Adolescent↗

Laparoscopic bilateral nephrectomy: results in 11 renal transplant patients.

PURPOSE: We report our experience with bilateral laparoscopic nephrectomy after renal transplantation. MATERIALS AND METHODS: Between August 1994 and October 1995, 11 patients who had previously undergone renal transplantation underwent bilateral laparoscopic nephrectomy at our hospital due to poorly controlled hypertension. The records of 10 patients undergoing bilateral open nephrectomy were reviewed for comparison. RESULTS: Mean operative time in the laparoscopy group was 195 minutes (range 125 to 270). Mean blood loss was 345 ml. and 1 patient required conversion to an open operation. Oral intake and mobilization were begun 1 day postoperatively. Mean postoperative morphine equivalent consumption was 14 mg., mean hospital stay was 4.2 days (range 3 to 6) and mean return to normal activities was 14 days. At a mean followup of 10.4 months blood pressure had improved significantly in 8 patients (73%). Mean operative time in the open surgery group was 145 minutes (range 115 to 170) and mean postoperative morphine equivalent required was 44 mg. Compared to the laparoscopy group the interval to resumption of oral intake (3.5 days), duration of hospital stay (10.7 days) and return to normal activities (36 days) were prolonged in the open surgery group. CONCLUSIONS: According to our results, bilateral laparoscopic nephrectomy could be an effective alternative for the treatment of severe hypertension after renal transplantation. Compared to open nephrectomy most patients benefit from the laparoscopic approach.

Adult↗

Laparoscopy in renal transplant patients.

OBJECTIVES: To evaluate the use of laparoscopic techniques in patients with a renal transplant. METHODS: Since 1992, 358 patients have undergone urologic laparoscopy at our hospital. Among these, 37 procedures (10.4%) were performed in patients with a renal transplant: 14 bilateral nephrectomies for severe drug-resistant hypertension, 9 marsupializations of symptomatic lymphoceles, 6 renal allograft biopsies in patients with clotting abnormalities, 6 unilateral nephrectomies, and 2 nephroureterectomies for recurrent episodes of pyelonephritis and symptomatic vesicoureteral reflux, respectively. RESULTS: Five complications (14%) and three conversions (8%) occurred. Patients who underwent successful laparoscopic operations began mobilization and oral intake on the day after the operation. The hospital stay ranged from 1 to 6 days. In the nephrectomy groups, perioperative urine outputs remained stable and post-operative urine outputs were increased as compared with those in the perioperative period (P < 0.05). Post-operatively, serum creatinine remained stable or improved in patients who underwent nephrectomy or marsupialization of lymphocele. CONCLUSIONS: Our results indicate that laparoscopic techniques are safe and effective in the treatment of patients with a renal transplant. Renal allograft function apparently is not affected by laparoscopic procedures.

Adult↗

1,25-dihydroxycholecalciferol enhances the expression of MHC class II antigens and intercellular adhesion molecule-1 by human renal tubular epithelial cells.

PURPOSE: Beside its role in calcium and phosphorus metabolism, 1,25-dihydroxycholecalciferol (1,25-D3) exerts multiple effects on cytokine and major histocompatibility complex (MHC) class II expression in monocytes and lymphocytes. In different renal diseases tubular epithelial cells express MHC class II molecules and cell adhesion molecules,, such as intracellular adhesion molecule-1 (ICAM-1). Therefore, modulation of MHC class II and ICAM-1 expression in renal tubular epithelial cells by 1,25-D3 may be relevant to lymphocyte adhesion to tubular epithelial cells and immune mediated renal injury. However, the expression of MHC class II antigens and cellular adhesion molecules by renal tubular epithelial cells in response to 1,25-D3 has not been investigated. MATERIALS AND METHODS: We generated human renal tubular epithelial cells and SV40 transfected tubular epithelial cells to investigate immune modulation of 1,25 on renal epithelial cells. Major histocompatibility complex class II molecules and ICAM-1 were detected by a specific enzyme linked immunoassay. RESULTS: We found a dose-dependent increase of both constitutive and induced MHC class II and ICAM-1 expression in tubular epithelial cells stimulated with 1,25-D3. Dose-dependent stimulation of MHC class II and ICAM-1 expression was not restricted to primary human renal tubular epithelial cells but was also detected in SV40 transfected cells. CONCLUSIONS: Expression of MHC class II and ICAM-1 is crucial for antigen presentation by and lymphocyte adhesion to renal tubular epithelial cells. Modulatory effects of 1,25-D3 on immune accessory function of renal tubular epithelial cells may be of clinical significance in renal diseases.

Calcitriol↗

Preoperative application of glucocorticosteroids efficaciously reduces the primary immunological response in kidney transplantation.

Early acute rejection episodes have a considerable influence on long-term prognosis of renal transplants. Therefore the aim of primary immunosuppressive therapy must be effective suppression of the immunological response following antigen recognition. Owing to their pharmacological properties, intravenously given glucocorticosteroids are suitable for the alteration of the primary immunological response. However, even after intravenous administration, glucocorticosteroids have a latency of hours prior to reaching maximum activity. In a prospective clinical study, 111 patients undergoing renal transplantation were preoperatively treated with 500 mg methylprednisolone for immunosuppressive induction. A historical group of 40 patients who had received the same dose as intraoperative bolus, was used for comparison. Postoperative immunosuppression did not substantially differ between the two groups. The incidence of acute rejections within 30 d after transplantation was a clinical parameter of the study. The mitogenic cytokine induction was measured in blood samples which were collected intraoperatively and on days 1, 2, and 5 after transplantation. Cytokine release served as an in vitro parameter for the immunological responsiveness of the transplant recipient. In the group under study, the incidence of acute rejections was 21% (23/111) and, in contrast, 43% (17/30) in the historical group (p < 0.05). 89% of the patients in the group being studied showed normal renal function after 1 yr, compared to 78% in the reference group (n.s.). Following preoperative (mean 5.09 h) administration of glucocorticosteroids, mitogenic cytokine induction (IL-1 beta, IL-2, sIL-2R and IFN-gamma) was almost completely blocked at the time of transplantation. A prospective, randomized study has just been started to evaluate the effect of preoperative administered glucocorticosteroids on the incidence of acute rejections and long-term allograft survival.

Adult↗

S fimbriae of uropathogenic Escherichia coli bind to primary human renal proximal tubular epithelial cells but do not induce expression of intercellular adhesion molecule 1.

We have recently reported an increase of expression of the intercellular adhesion molecule 1 by renal carcinoma cells in response to S fimbriae of Escherichia coli. Now we demonstrate that E. coli expressing S and P fimbriae strongly binds to human proximal tubular epithelial cells. However, in primary and simian virus 40-transfected renal tubular epithelial cells S fimbriae do not enhance the expression of intercellular adhesion molecule 1.

Bacterial Adhesion↗

Differences in cytokine secretion by intestinal mononuclear cells, peripheral blood monocytes and alveolar macrophages from HIV-infected patients.

Mononuclear cells of the lamina propria (LpMNC), isolated from endoscopically taken biopsies of the large bowel from AIDS patients, were analysed for their ability to secrete tumour necrosis factor-alpha (TNF-alpha), IL-1 beta and IL-6. Stimulation of LpMNC from normal controls with pokeweed mitogen (PWM) led to a time- and dose-dependent enhancement of TNF-alpha, IL-1 beta and IL-6 secretion. In contrast, PWM stimulation of LpMNC from AIDS patients resulted in only a small increase in TNF-alpha release. Constitutive secretion of IL-1 beta and IL-6 in these patients was already increased to the concentration range of stimulated cells from normal controls and could not be further increased, probably due to maximal in vivo stimulation. Secretion of TNF-alpha, IL-1 beta and IL-6 by peripheral blood monocytes (PBM) and alveolar macrophages from AIDS patients was elevated with or without stimulation compared with normal controls. Obviously, the regulation of TNF-alpha secretion is dependent on the microenvironment. Since it is known that interferon-gamma (IFN-gamma) may induce the production of TNF-alpha, the secretion of this cytokine was examined. Release of IFN-gamma was constitutively and under stimulation lowered in LpMNC from AIDS patients compared with normal controls. Addition of IFN-gamma to LpMNC did not result in enhanced TNF-alpha secretion. Our data indicate a defective function of intestinal mononuclear cells in AIDS patients as shown by the diminished TNF-alpha secretion.

HIV Infections↗

Feasibility of the adoptive transfusion of allogenic human leukocyte antigen-matched natural killer cells in patients with renal cell carcinoma.

Patients with metastasized renal cell carcinoma have a poor prognosis with conventional therapies. The feasibility and safety of donating purified natural killer (NK) cells without additional cytokines were evaluated. In contrast to all previous studies, the NK cells were derived from allogenic donors. The NK cell donors were HLA-C matched to enable NK cell inhibition via killer cell inhibitory receptors and HLA-C. This should obviate a graft-versus-host reaction against nonmalignant HLA-expressing tissues in the allogenic constellation. The average number of cells applied per transfusion was 1.02 +/- 0.265 x 10(9). The purity of the NK cells was 85% to 95%, and most of the contaminating cells were monocytes. Twenty-six transfusions given to 11 patients did not cause any minor or major adverse effects, with the exception of one episode of transient fever. One patient had an objective regression of his lung metastases that had been progressing continuously before. No cytotoxic HLA antibodies could be detected 3 weeks after the transfusions. The observed tolerance to this therapeutic regimen suggests the need for further studies with increased doses of cytokine-activated NK cells.

Adoptive Transfer↗

1,25-Dihydroxycholecalciferol stimulates the expression of intercellular adhesion molecule-1 in renal carcinoma cells.

1,25-Dihydroxycholecalciferol (1,25-D3) is a potent immunomodulatory vitamin modulating major histocompatibility complex class-II expression in monocytes and epithelial cells. However, the impact of 1,25-D3 on the expression of adhesion molecules in epithelial cells has not been investigated. Human renal tubular epithelial and renal carcinoma cells express intercellular adhesion molecule-1 (ICAM-1), a ligand of the leukocyte-function-associated antigen-1 (LFA-1). Therefore, we addressed the question whether 1,25-D3 modulates ICAM-1 expression by renal carcinoma cells. Using an enzyme-linked immunoassay we detected an increase in ICAM-1 expression by a renal carcinoma cell line (ACHN) cultured in the presence of 1,25-D3. Also, in ACHN cells stimulated with gamma-IFN a significant stimulatory effect of 1,25-D3 was evident. ICAM-1 is crucial for the adhesion of LFA-1-expressing lymphocytes and is involved in antigen presentation. In addition, ICAM-1 may be of significance in lymphocyte lysis of tumor cells. Therefore, the impact of 1,25-D3 on ICAM-1 expression by renal and non-renal and non-renal carcinoma cells and renal tubular epithelial cells may be of clinical importance.

Animals↗