Augmentation cystoplasty in children without preoperative mechanical bowel preparation

OBJECTIVE

To retrospectively assess early postoperative complications in augmentation cystoplasty without preoperative mechanical bowel preparation (MBP).

MATERIAL AND METHODS

Between May 1987 and May 2006, 162 cystoplasties were performed in 158 children. The segments used were: sigmoid colon (81.5%), ileum (13%), and ileocecum (5.5%). The mean age was 8.65 years (range 2.1-22.7 years). No preoperative MBP of any kind was used in any of the patients and all of them received antibiotics preoperatively and postoperatively.

RESULTS

No intraoperative complications related to the procedure were reported. The mean hospital stay was 9.48 days (range 4-30 days). The mean time to intake of oral fluids was 94.77 h (range 48-288 h). Postoperative complications occurred in 9.87%: urinary fistula was the most common (2.4%); only 3 patients presented wound infection (1.85%); 5 patients required reoperative surgery (hemoperitoneum, patch necrosis and 3 cases of urinary peritonitis); 1 patient presented an intra-abdominal abscess that resolved with antibiotic treatment.

CONCLUSIONS

Preoperative MBP can be omitted in children that require augmentation cystoplasty without an increased risk of infectious or anastomotic complications. Further prospective, randomized clinical trials should be carried out in order to validate our findings in the pediatric population.

Renal autotransplantation for the treatment of renovascular hypertension in the pediatric population

PURPOSE

To evaluate the effectiveness of renal autotransplantation (RA) for the treatment of renovascular hypertension (RVH) in a selected group of children in whom medical care, a percutaneous transluminal angioplasty or vascular reconstruction failed or was technically impossible, in addition to the short-term and long-term morbidity.

MATERIALS AND METHODS

A retrospective case review of 13 pediatric patients with severe or complicated RVH who underwent RA between May 1993 and August 2008 was conducted. We defined blood pressure (BP) response as follows: Cured: normal BP values with no need of antihypertensive medication (AM); Improved: normal BP values with AM requirements; Failed: abnormal BP values despite treatment with AM.

RESULTS

16 RA were performed in 7 female and 6 male patients. Bilateral RA were performed in 2 females and in 1 male. The average age at consultation for hypertension was 8.5 years (range 4-12 years) and the time of transplantation was 9.12 years (range 6-13 years). Etiological diagnoses were: Takayasu disease (n = 5); renal artery fibrodysplasia (n = 3); mid-aortic syndrome (n = 3) and neurofibromatosis type I (n = 2). Results after RA were: Cured: 61.5%; Improved: 38.5%. No patient presented therapeutic failure during follow up time (median = 53.4 months). Only 1 case presented a postoperative complication.

CONCLUSIONS

RA is a procedure with no mortality and low morbidity rates that renders very satisfactory therapeutic results in the pediatric population.

[Botulinic toxin type A in the treatment of children with neurogenic bladder]

INTRODUCTION. Botulinum toxin A (BoNTA) is an alternative in children with neurogenic bladder refractory to anticholinergics. OBJECTIVE. To evaluate the initial effects of BoNTA in neurogenic bladders. PATIENTS AND METHODS 12 patients (9 myelomeningoceles, 1 tethered cord, 1 medullary astrocytoma, 1 Ewing's sarcoma) were studied. The pretreatment evaluation included: voiding diary, incontinence score, renovesical ultrasound, cystourethrography and urodynamic parameters. Patients received 300 UI of BoNTA via detrusor injections. They were re-evaluated at months 1, 3 and 6. After the third control, if improvement was confirmed, patients were injected again. Otherwise, surgery was indicated.

RESULTS

After the initial injection, 50% of patients achieved complete continence and 20% remained with minimal leaks. The mean maximum bladder capacity increased from 264 +/- 117 ml to 324 +/- 170 ml (P = 0.322). The mean detrusor pressure decreased from 46 +/- 17 cm H2O to 42 +/- 14 cm H2O (P=0.596). The mean bladder compliance increased from 7.6 +/- 5.9 ml/cm H2O to 10.4 +/- 6.4 ml/cm H2O (P = 0.290). The reflex voiding contractions disappeared in 2 patients; 8 presented trabeculae. Ten patients were reinjected and two underwent surgery.

CONCLUSION

70% urinary continence was achieved after the initial injection. No significant urodynamic changes were observed. A longer follow-up with subsequent injections is needed.

Deficiency of the autoimmune regulator AIRE in thymomas is insufficient to elicit autoimmune polyendocrinopathy syndrome type 1 (APS-1)

Thymomas are thymic epithelial neoplasms, associated with a variety of autoimmune disorders (especially myasthenia gravis), that apparently result from aberrant intra-tumourous thymopoiesis and export of inefficiently tolerized T-cells to the periphery. The autoimmune regulator (AIRE) drives the expression of self-antigens in the thymic medulla and plays an essential role in 'central' tolerance in both humans and mice. However, while inactivating AIRE mutations result in the 'autoimmune polyendocrinopathy syndrome type 1' (APS-1), its major features are not well reproduced in AIRE-knock-out mice. Therefore, alternative human disease scenarios with concomitant AIRE deficiency may be valuable tools to test conclusions drawn from mouse models. Here we show, in a large series, that approximately 95% of thymoma patients are 'chimeric'; expression of AIRE and major AIRE-related autoantigens (eg insulin) were undetectable in their tumours but maintained in their remnant thymic tissue and lymph nodes. Notably, despite the AIRE-deficient thymopoiesis in thymomas, disorders and autoantibodies typical of APS-1 were distinctly uncommon in these patients. The one striking similarity was in the recently observed neutralizing anti-type I interferon (IFN) antibodies, which are found at diagnosis in 100% of patients with APS-1 and in approximately 60% of patients with thymomas, as we show here. We conclude that APS-1 type autoantigens must be protected from autoimmunity by mechanisms that do not extend to the muscle autoantigens so frequently targeted in thymoma patients but so rarely recognized in APS-1. Thus our findings argue strongly for a tolerogenic function of AIRE beyond its role in negative T-cell selection in human thymopoiesis, and/or for specific autoimmunization against muscle in thymomas.

Checkpoint kinase 1 (CHK1) protein and mRNA expression is downregulated in aggressive variants of human lymphoid neoplasms

CHK1: gene encodes for a serine/threonine kinase involved in the regulation of cell cycle progression and DNA damage checkpoints. To determine the role of CHK1 in the pathogenesis of lymphoid neoplasms and its relationship to other DNA damage response genes, we have analyzed the gene status, protein, and mRNA expression in a series of tumors and nonneoplastic lymphoid tissues. CHK1 protein and mRNA expression levels were very low in both reactive tissues and resting lymphoid cells, whereas tumor samples showed a variable pattern of expression related to their proliferative activity. However, seven aggressive tumors showed a dissociate pattern of extremely low or negative protein expression in spite of a high proliferative activity. Four of these tumors were diffuse large B-cell lymphomas (DLCLs) with concordant reduced levels of mRNA, whereas one blastoid mantle cell lymphoma (B-MCL) and two DLCLs had relatively normal levels of mRNA. No gene mutations, deletions, or hypermethylation of the promoter region were detected in any of these cases. In all these tumors ATM, CHK2, and p53 genes were wild type. These findings suggest that CHK1 inactivation in NHLs occurs by loss of protein expression in a subset of aggressive variants alternatively to ATM, CHK2, and p53 alterations.

The role of ceramide in receptor- and stress-induced apoptosis studied in acidic ceramidase-deficient Farber disease cells

The activation of sphingomyelinases leading to the generation of ceramide has been implicated in various apoptotic pathways. However, the role of ceramide as an essential death mediator remains highly controversial. In the present study, we investigated the functional relevance of ceramide in a genetic model by using primary cells from a Farber disease patient. These cells accumulate ceramide as the result of an inherited deficiency of acidic ceramidase. We demonstrate that Farber disease lymphocytes and fibroblasts underwent apoptosis induced by various stress stimuli, including staurosporine, anticancer drugs and gamma-irradiation, equally as normal control cells. In addition, caspase activation by these proapoptotic agents occurred rather similarly in Farber disease and control fibroblasts. Interestingly, Farber disease lymphoid cells underwent apoptosis induced by the CD95 death receptor more rapidly than control cells. Our data therefore suggest that ceramide does not play an essential role as a second messenger in stress-induced apoptosis. However, in accordance with a role in lipid-rich microdomains, ceramide by altering membrane composition may function as an amplifier in CD95-mediated apoptosis.

The transcript release factor PTRF augments ribosomal gene transcription by facilitating reinitiation of RNA polymerase I

Termination of murine rDNA transcription by RNA polymerase I (Pol I) requires pausing of Pol I by terminator-bound TTF-I (transcription termination factor for Pol I), followed by dissociation of the ternary complex by PTRF (Pol I and transcript release factor). To examine the functional correlation between transcription termination and initiation, we have compared transcription on terminator-containing and terminator-less rDNA templates. We demonstrate that terminated RNA molecules are more efficiently synthesized than run-off transcripts, indicating that termination facilitates reinitiation. Transcriptional enhancement is observed in multiple- but not single-round transcription assays measuring either promoter-dependent or promoter-independent Pol I transcription. Increased synthesis of terminated transcripts is observed in crude extracts but not in a PTRF-free reconstituted transcription system, indicating that PTRF-mediated release of pre-rRNA is responsible for transcriptional enhancement. Consistent with PTRF serving an important role in modulating the efficiency of rRNA synthesis, PTRF exhibits pronounced charge heterogeneity, is phosphorylated at multiple sites and fractionates into transcriptionally active and inactive forms. The results suggest that regulation of PTRF activity may be an as yet unrecognized means to control the efficiency of ribosomal RNA synthesis.