Renal allograft accumulation of technetium-99m sulfur colloid as a predictor of graft rejection.

Differentiation between rejection (the most common cause) and many other possibilities for detrimental effects on graft function represents a difficult issue to diagnose the cause of renal allograft dysfunction. This study was designed to determine whether technetium-99m sulfur colloid (TSC) accumulation predicted graft rejection. We prospectively studied 54 episodes of allograft dysfunction in 53 kidney transplant recipients who underwent TSC scintiscanning and graft biopsy. Visual analysis of TSC uptake compared uptake, in the allograft with that in the marrow of the fifth lumbar vertebra (L5). A 3+ result meant that allograft uptake was greater than L5 marrow uptake; 2+, the same; 1+, less and finally 0, no allograft uptake. Transplant accumulation of 2+ or more was considered consistent with rejection (P = .01). Allograft biopsies interpreted based on the Banff Working Classification showed rejection in 45 of 54 renal biopsies with 42 the biopsy-proven rejection episodes showing at least 2+ graft uptake. Furthermore, this nuclear medicine technique had a sensitivity of 93.3%, a specificity of 44.4%, a positive predictive value of 89.3%, a negative value of 57.1% and an efficiency of 83.3% for the diagnosis of renal allograft rejection.

Transureteral lithotripsy in pediatric practice.

PURPOSE: The present study reviews ureteroscopy intervention for the treatment of ureteral stones in pediatric patients in the last 6 years at three institutions in Iran. PATIENTS AND METHODS: Sixty-six ureteroscopies were performed in 66 prepubertal patients (mean age 9 years; range 2-15 years) with a male/female ratio of 31/35. Ultrasonography, plain film, or intravenous urography was performed in all cases. The mean stone size was 8 mm (range 5-15 mm). All the interventions were performed under general anesthesia with semirigid ureteroscopes of 8F to 11.5F. The stone was located in the left ureter in 32 patients and in the right in 34 patients. Stones were located in the distal ureter in 59 patients, in the midureter in 5, and in the proximal ureter in 2. Before ureteroscopy, ureteral dilatation with a balloon was done to 12F if necessary. If the calculus could not be removed with the basket (stone.8 mm), lithotripsy using ultrasonic, electrohydraulic (EHL), or pneumatic equipment was performed. RESULTS: Ureteroscopy with an 11.5F, 9F, 8.5F, or 8F ureteroscope were performed in 26, 14, 5, and 21 patients, respectively, and ureteral dilatation was necessary in 23, 0, 0, and 2 cases, respectively. We were unable to introduce the ureteroscope into the ureter in three patients (two boys with an 11.5F ureteroscope and one girl with an 8.5F ureteroscope) with distal ureteral stones. The stones moved to the kidney in four patients. Stone management was with basketing alone in 14, EHL in 3, ultrasonic lithotripsy in 8, and ballistic lithotripsy in 34 patients. The stone-free rate was 88% (58 patients) at 48 hours postprocedure. The complication rate was 23% and included renal colic (1), gross hematuria (11), and pyelonephritis (3). No patient had obvious perforation or stricture of the ureter at 3-month follow-up. CONCLUSION: Our series demonstrates the high success rate that can be achieved with ureteroscopic removal of ureteral calculi in children. Ureteroscopic treatment, especially with a small-caliber ureteroscope, should be considered the first choice for treatment of calculi in the distal ureter in children.

Fas/Fas ligand deficiency results in altered localization of anti-double-stranded DNA B cells and dendritic cells.

Autoantibodies directed against dsDNA are found in patients with systemic lupus erythematosus as well as in mice functionally deficient in either Fas or Fas ligand (FasL) (lpr/lpr or gld/gld mice). Previously, an IgH chain transgene has been used to track anti-dsDNA B cells in both nonautoimmune BALB/c mice, in which autoreactive B cells are held in check, and MRL-lpr/lpr mice, in which autoantibodies are produced. In this study, we have isolated the Fas/FasL mutations away from the autoimmune-prone MRL background, and we show that anti-dsDNA B cells in Fas/FasL-deficient BALB/c mice are no longer follicularly excluded, and they produce autoantibodies. Strikingly, this is accompanied by alterations in the frequency and localization of dendritic cells as well as a global increase in CD4 T cell activation. Notably, as opposed to MRL-lpr/lpr mice, BALB-lpr/lpr mice show no appreciable kidney pathology. Thus, while some aspects of autoimmune pathology (e.g., nephritis) rely on the interaction of the MRL background with the lpr mutation, mutations in Fas/FasL alone are sufficient to alter the fate of anti-dsDNA B cells, dendritic cells, and T cells.

Alterations in splenic architecture and the localization of anti-double-stranded DNA B cells in aged mice.

Aging is characterized by a decline in humoral immunity and a concommitant increased incidence of anti-DNA and other autoantibodies. To define how the regulation of autoreactive B cells is altered with age, we have used BALB/c mice with an Ig heavy H chain transgene to track the fate of anti-double-stranded (ds) DNA B cells in vivo. In young adult mice, anti-dsDNA B cells are developmentally arrested and excluded from the splenic B cell follicle, whereas in most aged mice they are mature and localize within the B cell follicle. Furthermore, we have detailed global changes in lymphoid architecture that accompany aging: CD4(+) T cells are found not only in the periarteriolar lymphoid sheath, but also in the B cell follicles. Strikingly, these disruptions are similar to those that precede serum anti-dsDNA antibody expression in autoimmune MRL-lpr/lpr mice.

The origin of anti-nuclear antibodies in bcl-2 transgenic mice.

bcl-2 transgenic mice develop anti-double-stranded (ds) DNA antibodies similar to those present in systemic lupus erythematosus. To begin to understand where a breakdown in the regulation of autoreactive lymphocytes is occurring, we have used a bcl-2 transgene (Tg) in conjunction with an Ig Tg that allows us to identify and track anti-dsDNA B cells. Previously, we have shown that anti-dsDNA B cells are actively tolerized in BALB/c mice as manifested by their developmental arrest, follicular exclusion, increased in vivo turnover rate and lack of their antibody in the serum. The bcl-2 Tg mice increased the lifespan of anti-dsDNA B cells, but did not alter the other features of tolerance, indicating that the anergy of the anti-dsDNA B cells is independent of their reduced lifespan. Furthermore, these data suggest that the serum anti-dsDNA antibodies in bcl-2 transgenic mice are not due to a breakdown in the induction or maintenance of B cell anergy; rather they may originate from B cells that have transited through a germinal center.

Functional consequences of the developmental arrest and follicular exclusion of anti-double-stranded DNA B cells.

Anti-dsDNA B cells are actively tolerized in nonautoimmune BALB/c mice, as manifested by their developmental arrest, follicular exclusion, and rapid turnover rate. Previously, we have documented changes in the maturation status and follicular localization of anti-dsDNA B cells in autoimmune-prone MRL (+/+ and lpr/lpr) mice. To determine whether these differences in developmental status and follicular localization affect the functional capacity of anti-dsDNA B cells, we have now compared their in vivo life spans and their responses to in vitro stimuli. Our study shows that although anti-dsDNA B cells from both BALB/c and MRL-+/+ mice are localized to the T/B interface, only those in BALB/c mice have a rapid turnover rate. Therefore, the immature status and not the exclusion from the B cell follicle correlates with a shortened life span. Interestingly, apoptotic anti-dsDNA B cells were not detected at the T/B interface in BALB/c mice, suggesting that they are not dying there. This study also demonstrates that anti-dsDNA B cells, regardless of maturation status or follicular localization, are able to proliferate and up-regulate the costimulatory molecule B7-2 in response to CD40 ligand and IL-4. Therefore, one of the critical in vivo differences between anti-dsDNA B cells in BALB/c and MRL-+/+ mice compared with MRL-lpr/lpr mice may be the availability of T cell help.

Proper use of gastrointestinal tract to achieve continent urinary diversion in 73 patients.

Different segments of the gastrointestinal tract have been used to reconstruct the bladder and all have been reviewed in regard to achieving urinary continence. In 53 patients with detubularized ileocecal cystoplasty, the continence rate, both during the day and night, was 88%, while 95% of the patients were continent during the daytime. In nine patients in whom an ileocecal continent reservoir was made, 100% had dry stoma on intermittent catheterization, both during the day and night. We conclude that detubularization of the right colon has a significant effect in achieving urinary control and making a good low pressure pouch. This has helped us to avoid conduits with their inherent problems. Also, the right colon by virtue of the ileocecal valve has good versatility for use in both anti-incontinence or anti-reflux procedures as needed.