[External validity of a relevant model for Irritable Bowel Syndrome (IBS) using chronic stress by water avoidance in Wistar rats]. / Validez externa de un modelo experimental para síndrome de intestino irritable (SII) mediante estrés crónico por evitación al agua en ratas Wistar.

BACKGROUND: Development of animal models has been one of the most remarkable achievements for Irritable Bowel Syndrome (IBS) research. These models need to exhibit face validity, construct and predictive validity, as well as internal (replicability) and external validity (generalizability). Among these models, chronic stress induced by water avoidance exposure (WA) has been validated in rats through increasing visceral hypersensitivity, motility impairment, anxiety and, colonic immune activity, all related to IBS. OBJECTIVE: To assess the external validity of WA indirectly on colonic motility in Wistar rats. METHOD: Ten male-Wistar rats were exposed to WA and compared with ten Wistar rats not exposed (controls). At the end of each exposure, the quantity of fecal pellets were determined and considered as a sign of autonomic regulation of colonic motility. Data was analyzed with a general linear model for repeated measures. RESULTS: Rats exposed to WA had higher number or pellets than controls: 7.46 ± 0.45 (95%CI: 6.51, 8.41) vs. 2.88 ± 0.45 (1.93, 3.83), p < 0.001. The higher number of pellets was related to WA exposure as there were no other significant interactions. In both groups, the number of pellets was higher during the first day and then decreased progressively. CONCLUSIONS: Chronic stress induced through WA in Wistar rats, exhibits external validity as an experimental model for IBS research and our findings of increased number of fecal pellets coincide with the appearance hypermotility related to IBS. The model is optimum for research studies on this disorder.

[Communication based on the P300 component of event-related potentials: a proposal for a matrix with images]. / Comunicación basada en el componente P300 de los potenciales relacionados con eventos: propuesta de una matriz con imágenes.

INTRODUCTION: For more than two decades, several research groups have tried to build a device called "brain computer interface" (BCI) to make it available for people having several disabilities such as the locked in syndrome through the use of the recording of electroencephalography activity while the patients are being visually stimulated. AIM. To obtain a P300 component elicited by intensifications of images arranged in a matrix in an oddball paradigm in two selection modes: assigned and free. SUBJECTS AND METHODS: A 5 x 5 matrix for communication purposes was used to visually stimulate 12 volunteers while their event related potentials were recorded in three leads (Fz, Cz and Pz). Off-line analyses were performed to obtain the P300 component which was elicited by targets images intensified randomly by rows or columns. RESULTS: In both modalities assigned and free, all volunteers generated a reliable P300 component. Confirmation of the selected images was made through a comparison of the P300 when each target, row and column matched. In the free selection mode, higher amplitude and a broader activation including frontal leads was observed. No significant differences in the P300 latency were found. CONCLUSION: In all volunteers the elicited P300 allows the identification of the selected images in the 5 x 5 matrix. In the present study the use of drawings representing ideas instead of letters might increase the communication rate in a P300-based BCI.

Leiomyoma of bladder.

A case of leiomyoma of the bladder is presented. The symptoms of this rare benign tumor depend on the size, location, or associated urinary tract infection. The diagnosis may be confirmed by transurethral biopsy, and, since these tumors are well encapsulated, the treatment of choice is total enucleation from the vesical wall. Transurethral resection as a definitive modality of treatment should be attempted only in small tumors.

Staghorn calculis: its clinical presentation, complications and management.

There were 95 patients (105 kidneys) with staghorn calculi evaluated clinically and 84 kidneys were studied on a pathologic basis. Only 1 percent of the patients could be defined as having a silent stone calculus. Clinical complications occurred in 53 per cent of the patients. Of 84 kidneys submitted for a pathoanatomic study (surgical evaluation and/or histopathology) pyonephrosis was found in 20 per cent, xanthogranulomatous pyelonephritis in 8 per cent, end stage pyelonephritic kidney in 6 per cent, end state hydronephrotic kidney in 7 per cent, severe pyelonephritic changes in 7 per cent and a perinephric abscess in 5 per cent. The kidney was considered to be relatively undamaged in 51 per cent of the cases. Complete removal of the calculus and appropriate medical adjunctive therapy should be done early in the course of the disease in an attempt to prevent complications and renal deterioration. The results of treatment are discussed and compared to those obtained in a group of patients who initially were managed conservatively.

Adrenal hemangioma.

This constitutes the twelfth case of adrenal hemangioma reported to date. The clinical presentation, radiographic characteristics, and management are reviewed. Although rare, these tumors should be part of the differential diagnosis in adrenal neoplasms.

Experimental use of fluoroalkyl cyanoacrilate in ureteral anastomosis.

A fluorinated tissue adhesive Fluoroalkyl Cyanoacrilate has been used in end-to-end ureteral anastomoses as an adjunct to suture material to avoid urinary extravasation in seven dogs. A similar number of dogs served as controls. The urinary tracts were evaluated grossly, radiographically, and histologically after 3 to 12 months. Better anatomical results and less inflammatory reaction and fibrosis were found in the group submitted to the tissue adhesive.

Pyeloileovesical diversion in a case of prune belly syndrome.

A case of prune belly syndrome that was managed at birth with cutaneous ureterostomies and later reconstructed with a pyeloileovesical diversion (reversed 7) is presented. This constitutes the first report of such treatment in this anomaly. The indications, operative procedure and results after long-term followup are discussed.

Renocolic fistula.

A case of left renocolic fistula secondary to chronic pyonephrosis has been reported. Neprectomy, excision of the fistulous tract, and closure of the colon is the treatment of choice. This was accomplished in this case with excellent results.