Comparison of laparoscopic and open pyeloplasty in 100 patients with pelvi-ureteric junction obstruction.

BACKGROUND: This study aimed to determine whether the morbidity and outcome rates for laparoscopic transperitoneal dismembered pyeloplasty are different from those for dismembered pyeloplasty, to analyze the learning curve of laparoscopic pyeloplasty, and to determine whether preoperative stent placement affects outcome. METHODS: For this study, 49 laparoscopic pyeloplasties (period 2000-2005) and 51 open pyeloplasties (period 1992-2003) were reviewed. RESULTS: Compared with open procedures, laparoscopic procedures were associated with a longer mean operating time (159 vs 91 min; p < 0.001), a shorter mean time to normal diet (38 vs 72 h; p < 0.001), and a similar mean hospital stay (5 days; p = 0.6). The operative complication rates were 17% for primary laparoscopic pyeloplasties and 24% for primary open pyeloplasties. The rates were higher for secondary procedures. The success rates for primary and secondary procedures were, respectively, 98% (41/42) and 57% (4/7) for laparoscopy and 96% (46/48) and 67% (2/3) for open surgery. Failed procedures showed no improvement in loin pain or obstruction. At the 6-month follow-up evaluation, 29% of the open surgery patients but none of the laparoscopic surgery patients reported wound pain. CONCLUSIONS: The efficacy of laparoscopic pyeloplasty is equivalent to that of open pyeloplasty, with less wound pain at 6 months. The outcome for secondary procedures is inferior. There was a trend toward a reduction in complications and the conversion rates with time, suggesting that there may be a learning curve of approximately 30 laparoscopic pyeloplasty cases. Preoperative stent insertion did not seem to affect any objective measures of outcome for laparoscopic pyeloplasty.

Normal and pathological erectile function: the potential clinical role of endothelin-1 antagonists.

Erectile dysfunction (ED) is a common problem, particularly in older men. The production of penile erection involves an interplay between autonomic nerves and locally released vasoactive mediators. Endothelin-1 (ET-1) is a peptide released from endothelium in the corpus cavernosum, which causes smooth muscle contraction. Recent studies have investigated the physiological significance of ET-1 in the control of erectile function and it may play a role in detumescence. There is also much evidence to link ET-1 to risk factors for ED. ET-1 antagonists may prove beneficial in the treatment of ED and also in prevention of long term deterioration of erectile function. These antagonists may also find a role when used in combination with agents, which are established for the treatment of ED.

Sequential development of the liver lesions in new-born lambs infected with Rift Valley fever virus. II. Ultrastructural findings.

The macroscopic and microscopic lesions in livers of new-born lambs experimentally infected with Rift Valley fever virus and killed at various intervals between 6-53 h after inoculation, were described in a previous paper. This communication gives an overview of the ultrastructural changes affecting hepatocytes, sinusoids and spaces of Disse, biliary tree and portal triads as well as observations on the morphology and morphogenesis of the virus. Hepatocytes were those primarily affected, while inflammatory and architectural changes were secondary. The changes included prominent nuclear alterations, fragmentation or disintegration of necrotic hepatocytes, focal cytoplasmic degradation and sequestration, and the presence of acidophilic bodies. The ultrastructure and origin of the intranuclear inclusions are discussed.

ATP release from the human ureter on distension and P2X(3) receptor expression on suburothelial sensory nerves.

It is not clear how the increase in intraluminal pressure behind an obstructing ureteric calculus causes an increase in action potential frequency in ureteric sensory nerves so the pain messages are transmitted to the brain. It has been proposed that ureteric distension causes urothelial release of ATP, which activates purinoceptors on suburothelial nociceptive sensory nerves. The purpose of this study was to determine whether distension of the human ureter results in the release of ATP and whether the nociceptive P2 receptor, P2X(3), is expressed on suburothelial sensory nerves in the human ureter. Human ureter segments were perfused with Krebs solution and intermittently distended to a range of pressures. Samples of perfusate were collected throughout and the ATP concentration ([ATP]) was determined using a luciferin-luciferase assay. Sections of ureter were stained using antibodies against P2X(3) and capsaicin receptors (TRPV1). [ATP] rose to more than 10 times baseline levels after distension beyond a threshold of 25-30 cmH(2)O. Immunofluorescence studies on consecutive frozen sections showed that suburothelial nerves stained positively for P2X(3) and capsaicin receptors, with no staining in controls. These findings are consistent with the hypothesis that purinergic signalling is involved in human ureteric mechanosensory transduction, leading to nociception.

Alterations in cholinergic and purinergic signaling in a model of the obstructed bladder.

PURPOSE: There is increasing evidence that purinergic signaling may have a role in the generation of detrusor contractions in the pathologically unstable human bladder. However, study of the rabbit model of partial bladder outlet obstruction showed a loss in cholinergic and purinergic innervation after 3 months. We examined changes in the cholinergic and purinergic components contributing to nerve mediated detrusor contraction in a rabbit model of detrusor instability secondary to bladder outlet obstruction during the early hypertrophic stage. MATERIALS AND METHODS: Partial bladder outlet obstruction was surgically induced in adult male rabbits. At 3 weeks detrusor strips were obtained and contractions were produced by electrical field stimulation in the presence of 1 microM. atropine and/or 30 microM. of the P2-purinoceptor antagonist pyridoxalphosphate-6-azophenyl-2'4'-disulfonic acid, and after adding 1 microM. tetrodotoxin. Purinergic and cholinergic components were calculated and compared with those from sham operated controls. RESULTS: The cholinergic or atropine sensitive component was frequency dependent, that is smaller at lower frequencies. The cholinergic component was decreased in the early obstructed bladder. The pyridoxalphosphate-6-azophenyl-2'4'-disulfonic acid sensitive purinergic component was frequency dependent, that is larger at lower frequencies. The purinergic component was increased in the early obstructed bladder. The overall electrical field stimulation response or the response to KCl was unaltered in the obstructed group. There was no difference in the response in strips from the bladder neck and dome. CONCLUSIONS: The purinergic component of nerve mediated detrusor contraction is increased and the cholinergic component is decreased in early stages of bladder obstruction in this rabbit model.