PubMed Health⌕ Search

Biomedical subjects

Ithaar Derweesh

Publications and source records attributed to Ithaar Derweesh.

7 recordsLinked to original sources

Partial nephrectomy for renal urothelial tumors: clinical update.

OBJECTIVES: To evaluate the contemporary indications and outcome after partial nephrectomy for renal urothelial cancer. Partial nephrectomy is an established treatment for renal cell cancer but its use for renal urothelial tumors has been studied less extensively. METHODS: Records were reviewed for patients undergoing partial nephrectomy for renal urothelial tumors between January 1990 and December 2001. Partial nephrectomy was selected for those with a solitary kidney, chronic renal insufficiency, or bilateral synchronous tumors. Partial nephrectomy was performed according to the principles of partial nephrectomy. Follow-up included ultrasonography, intravenous urography, computed tomography, metastatic workup, and renal function evaluation. RESULTS: This study included 12 patients (12 kidneys, 10 solitary) with a mean age of 68.5 +/- 21 years and a mean follow-up of 40.8 +/- 32 months. The pathologic T stage was Tis in 1 patient, T1 in 3, T2 in 2, and T3 in 6 patients. Of the 12 patients, 6 had negative surgical margins, and 4 of the 12 patients (30%) were tumor free after a mean follow-up of 57.7 months. Of the 6 patients with positive surgical margins (Stage T1 in 2 and T3 in 4), 1 developed recurrence and 3 developed metastasis; 4 died after a mean of 31.3 months. Overall recurrence was seen in 5 (42%) and progression (metastasis) in 6 (50%) patients. Of the 12 patients, 6 were alive, 4 of them were well (mean serum creatinine 1.83 mg/dL) at 62 months of follow-up. Two patients required dialysis. The overall long-term survival rate was 50%. CONCLUSIONS: Partial nephrectomy for renal urothelial tumors is feasible and should be considered in a select population. Dialysis or renal replacement can be delayed or avoided in most of these patients, but strict surveillance remains mandatory.

Aged↗

Expression of EphA2 is prognostic of disease-free interval and overall survival in surgically treated patients with renal cell carcinoma.

Whereas normally expressed at sites of cell-to-cell contact in adult epithelial tissues, recent studies have shown that the receptor tyrosine kinase EphA2 is overexpressed in numerous epithelial-type carcinomas, with the greatest level of EphA2 expression observed in metastatic lesions. In the current study, we have assessed EphA2 expression in archived renal cell carcinoma (RCC) tissues as it relates to patient disease course. Using specific anti-EphA2 monoclonal antibody 208 and immunohistochemistry, we evaluated EphA2 protein expression levels in RCC specimens surgically resected from 34 patients (including 30 conventional clear-cell RCC, 3 papillary, and 1 chromophobic RCC cases) resulting in clinical cures. Regardless of histopathologic subtype, RCC lesions expressing higher levels of EphA2 tended to be of a higher grade (P < 0.05) and larger (P = 0.093), more-highly-vascularized tumors (P = 0.005). Perhaps most notable, the degree of EphA2 overexpression (versus normal matched autologous kidney tissue) seemed predictive of short-term (<1 year) versus longer-term (> or =1 year) disease-free interval (P < 0.001) and of overall survival (P < 0.001) among the RCC patients evaluated. These data suggest that EphA2 expression level may serve as a useful prognostic tool in the clinical management of patients who have been successfully treated with surgery, but who are at greater risk for accelerated disease recurrence and who have a poorer prognosis.

Adult↗

Degradation of NF-kappa B in T cells by gangliosides expressed on renal cell carcinomas.

T cells from cancer patients are often functionally impaired, which imposes a barrier to effective immunotherapy. Most pronounced are the alterations characterizing tumor-infiltrating T cells, which in renal cell carcinomas includes defective NF-kappaB activation and a heightened sensitivity to apoptosis. Coculture experiments revealed that renal tumor cell lines induced a time-dependent decrease in RelA(p65) and p50 protein levels within both Jurkat T cells and peripheral blood T lymphocytes that coincided with the onset of apoptosis. The degradation of RelA/p50 is critical for SK-RC-45-induced apoptosis because overexpression of RelA in Jurkat cells protects against cell death. The loss of RelA/p50 coincided with a decrease in expression of the NF-kappaB regulated antiapoptotic protein Bcl-xL at both the protein and mRNA level. The disappearance of RelA/p50 protein was mediated by a caspase-dependent pathway because pretreatment of T lymphocytes with a pan caspase inhibitor before coculture with SK-RC-45 blocked RelA and p50 degradation. SK-RC-45 gangliosides appear to mediate this degradative pathway, as blocking ganglioside synthesis in SK-RC-45 cells with the glucosylceramide synthase inhibitor, PPPP, protected T cells from tumor cell-induced RelA degradation and apoptosis. The ability of the Bcl-2 transgene to protect Jurkat cells from RelA degradation, caspase activation, and apoptosis implicates the mitochondria in these SK-RC-45 ganglioside-mediated effects.

Adjuvants, Immunologic↗

Factors related to delayed graft function after laparoscopic live donor nephrectomy.

PURPOSE: Delayed graft function after live donor transplantation affects 5% to 10% of recipients regardless of procurement technique. This delay in function is associated with an increased risk of rejection and decreased graft survival. In the present study we critically assess allograft recovery to identify the risk factors related to delayed graft function. MATERIALS AND METHODS: We retrospectively reviewed donor and recipient medical records from 100 consecutive laparoscopic live donor nephrectomies from August 1997 to October 2001. Four criteria were used to classify delayed graft function: I) requirement of dialysis in postoperative week 1, II) creatinine 2.5 mg/dl or greater at postoperative day 5, III) time to half peak activity (mercaptoacetyltriglycine renal scan) at postoperative day 5 greater than 12.2 minutes (normal range 1 to 12.2) and IV) time to peak activity (mercaptoacetyltriglycine renal scan) at day 5 greater than 6.5 minutes (normal range 2.1 to 6.5). Patients could qualify for multiple outcome categories. Patients who did not match any of these criteria were classified as having normal renal function (outcome 0). RESULTS: The number of patients in the delayed graft function categories were 5 with outcome I, 14 with outcome II, 39 with outcome III and 24 with outcome IV. There were 23 patients represented in more than 1 category and 59 patients were classified as having normal function. Recipient age, donor/recipient gender relationship, unrelated highly mismatched donors and cold/total preservation time were identified as risk factors related to impaired early renal function recovery. None of the variables related to the laparoscopic technique itself represented risk factors for delayed graft function. CONCLUSIONS: Female donor kidneys into male recipients and highly HLA mismatched donors represent factors that may be controlled by donor selection when feasible. All attempts should be made to decrease cold ischemia time and, therefore, total preservation time. Prolonged carbon dioxide pneumoperitoneum, warm ischemia time, renal artery length or use of right kidney did not adversely affect the functional outcome of the allografts procured laparoscopically.

Adult↗

The influence of various maintenance immunosuppressive drugs on lymphocele formation and treatment after kidney transplantation.

PURPOSE: We compared the incidence of lymphocele formation and treatment in kidney transplant recipients given 3 immunosuppressive drug regimens. MATERIALS AND METHODS: Consecutive series of adult kidney only recipients, including group 1-152 who received sirolimus/mycophenolate mofetil (MMF)/prednisone (P), group 2-168 who received cyclosporine/MMF/P and group 3-193 who received cyclosporine/azathioprine/P, were analyzed for post-transplantation lymphocele formation. All available records and imaging studies were reviewed, such as ultrasound, computerized tomography, magnetic resonance imaging etc, for peritransplant fluid collections greater than 2.5 cm. Demographic characteristics and the risk factors for lymphocele were compared in these 513 recipients using univariate and multivariate analysis. RESULTS: The overall incidence of lymphocele formation was 174 of 513 cases (33.9%) and the incidence of treated lymphoceles was 81 of 513 (15.7%). In groups 1 to 3 the incidence was 45.5%, 33.9% and 24.7%, respectively. These differences were significantly higher in group 1 vs groups 2 or 3 (p = 0.014) but they were not significantly different between groups 2 and 3. Similarly the incidence of treated lymphoceles was 23%, 12.5% and 12.9%, respectively. Findings were again statistically higher in group 1 vs groups 2 and 3 (p = 0.003) but not statistically significant between groups 2 and 3. A greater number of group 1 patients required surgical interventions compared with those in groups 2 and 3 (13.8% vs 4.7% and 4.8%, respectively, p = 0.019). In addition, acute rejection (p = 0.001) and body mass index greater than 32 (p = 0.02) were significant risk factors on multivariate analysis. CONCLUSIONS: The combination of sirolimus/MMF/P, obesity with a body mass index of greater than 30 kg/m and acute rejection are independent risk factors for lymphocele formation and treatment after kidney transplantation. Patients should be counseled and consideration should be given to prophylactic measures in this higher risk renal transplant population.

Adult↗

The impact of sirolimus, mycophenolate mofetil, cyclosporine, azathioprine, and steroids on wound healing in 513 kidney-transplant recipients.

BACKGROUND: The aim of this study was to determine whether there has been an increase in the incidence or severity of wound-healing complications that can be attributed to the introduction of newer immunosuppressive drugs. METHODS: Consecutive series of adult kidney-only transplant recipients were selected from our Unified Transplant Database backward from September 2002. There were 513 patients divided into groups on the basis of their maintenance immunosuppression given for at least the first 30 days posttransplant. Group I (152) was given sirolimus, mycophenolate mofetil, and prednisone (SRL/MMF/P) between March 2000 and September 2002; group II (168) was given cyclosporine A (CsA)/MMF/P between January 1999 and July 2002; and group III (193) was given azathioprine (AzA)/CsA/P between January 1993 and December 1997. A classification system for wound-healing problems was developed, and each of the three groups was analyzed by univariate and multivariate analysis. RESULTS: From groups III to II to I, there was a significant increase in mean age (42.4 vs. 49 years), percent of patients diabetic (17% vs. 29%), mean body mass index (BMI) (24.2 vs. 27.1 kg/m2), and percent BMI greater than 30 (13.5% vs. 27%). The cumulative percentage of all wound-healing problems between group I (19.7%) vs. group II (16.1%) and group III (15.6%) was not significantly different. The most significant risk factor was a recipient BMI greater than 30 (P=0.0012) and delayed graft function (P=0.0041). CONCLUSIONS: During a 10-year period marked by changing recipient demographics, the introduction of MMF and SRL did not result in a significant increase in transplant wound-healing complications. The most significant risk factor associated with transplant wound-healing complications remains body weight, which was the major influence for each of the immunosuppressive drug combinations described.

Adrenal Cortex Hormones↗