The ureteral access system: a review of the immediate results in 43 cases

The ureteral access set was used 43 times during an 18-month period between 1984 and 1985. Stones lodged throughout the ureter and in the renal pelvis were extracted with a success rate of 51 per cent. Of the upper tract strictures 92 per cent were dilated successfully. Filling defects were diagnosed in 88 per cent of the cases. Foreign bodies were retrieved, Double-J stents were placed and biopsies were successful in each case. Ureteral perforation in 28 per cent of the cases was caused by the dilator in 8 of 12 (19 per cent over-all). The technique and short-term results are discussed. Long-term followup data are not yet available.     

Epithelial secretion of vinblastine by human intestinal adenocarcinoma cell (HCT-8 and T84) layers expressing P-glycoprotein.

P-glycoprotein expression was demonstrated in two human intestinal adenocarcinoma cell-lines (HCT-8, ileocaecal and T84, colonic) by immunoprecipitation of a 170-180 kDa protein with monoclonal antibody JSB-1. Both HCT-8 and T84 formed functional epithelial cell layers of high transepithelial electrical resistance (greater than 700 omega.cm2) when grown on permeable matrices. These epithelial layers demonstrated vectorial secretion (net vinblastine fluxes in the basal-to-apical direction of 0.135 and 0.452 pmol h-1 cm-2 in HCT-8 and T84 cell layers, respectively, from bathing solutions containing 10 nM vinblastine). These vectorial vinblastine secretions were sensitive to inhibition by verapamil. Passive transepithelial vinblastine permeation was limited by the presence of intercellular (tight) junctions, as demonstrated by the high transepithelial electrical resistance, and verapamil increased this passive vinblastine permeation concomitant with a reduction in the electrical resistance. Cellular vinblastine loading was significantly greater from the basal side, and this was also susceptible to inhibition by basal verapamil. The demonstration of vectorial transport of vinblastine in human intestinal colonic adenocarcinoma cell layers is direct evidence in favour of the hypothesis that the function of mdr1 in epithelial from the gastrointestinal tract is to promote detoxification by a process of epithelial secretion. This study also highlights that cellular vinblastine accumulation depends not only upon P-glycoprotein function, but also upon differential apparent membrane permeabilities and the presence of intercellular (tight) junctions that may restrict drug permeation and cellular accumulation to apical or basal membrane domains.     

Audiologic evaluation of the otitis media patient

Because of the complexity and variability in the expression of otitis media, its effects on auditory function are diverse. The various influences of otitis media on auditory function are described within this article, including acoustic reflex, audiometry, and tympanometry.     

The impact of lower urinary tract symptoms on general health status and on the use of prostatectomy

Our objective was to determine the extent to which lower urinary tract symptoms affect the general health status of men and contribute to the decision to undergo surgery. A cross-sectional population survey using postal questionnaires was conducted in the North West Thames health region, followed by a prospective cohort study of men undergoing prostatectomy (North West Thames and Oxford regions). The subjects in the first survey were 221 men aged 55 and over with previously reported mild, moderate or severe urinary symptoms; subjects in the second study were 388 men undergoing prostatectomy. Main outcome measures were selfreported symptom severity, bothersomeness and general health status (Nottingham Health Profilie, Part 1). The response rate among eligible responders in the population survey was 85.7%. Increasing symptom severity was associated with worsening NHP scores for energy, emotional reactions, sleep and physical mobility (p<0.01). Increasing bother-someness of symptoms was associated with emotional reactions, sleep and pain (p<0.05). Men undergoing surgery reported worse health status than men in the population with the same severity of symptoms as regards emotional reactions, energy and pain. For a given level of symptom severity, the impact of those symptoms on aspects of a man's general health status may be the determinant of seeking and undergoing surgery. Greater understanding of the factors that affect a man's response to his symptoms is needed in interpreting the decision to seek and accept treatment.     

Handling of asymmetrical dimethylarginine and symmetrical dimethylarginine by the rat kidney under basal conditions and during endotoxaemia.

BACKGROUND: Asymmetrical dimethylarginine (ADMA) is capable of inhibiting nitric oxide synthase enzymes, whereas symmetrical dimethylarginine (SDMA) competes with arginine transport. The potential role of inflammation in the metabolism of ADMA has been elucidated in an in vitro model using tumour necrosis factor-alpha, resulting in a decreased activity of the ADMA-degrading enzyme dimethylarginine dimethylaminohydrolase (DDAH). The kidney probably plays a crucial role in the metabolism of ADMA by both urinary excretion and degradation by DDAH. We aimed to further elucidate the role of the kidney in a rat model under basal conditions and during endotoxaemia. METHODS: Twenty-five male Wistar rats weighing 275-300 g were used for this study. The combination of arteriovenous concentration differences and kidney blood flow allowed calculation of net organ fluxes. Blood flow was measured using radiolabelled microspheres according to the reference sample method. Concentrations of ADMA, SDMA and arginine were measured by high-performance liquid chromatography. RESULTS: The kidney showed net uptake of both ADMA and SDMA and fractional extraction rates were 35% and 31%, respectively. Endotoxaemia resulted in a lower systemic ADMA concentration (P = 0.01), which was not explained by an increased net renal uptake. Systemic SDMA concentrations increased during endotoxaemia (P = 0.007), which was accompanied by increased creatinine concentrations. CONCLUSIONS: The rat kidney plays a crucial role in the regulation of concentrations of dimethylarginines, as both ADMA and SDMA were eliminated from the systemic circulation in substantial amounts. Furthermore, evidence for the role of endotoxaemia in the metabolism of dimethylarginines was obtained as plasma levels of ADMA were significantly lower in endotoxaemic rats.     

Pseudoinvasion with high-grade dysplasia in a colonic adenoma. Distinction from adenocarcinoma

High-grade dysplasia was found to extend to an area of pseudoinvasion in the submucosa of a colonic adenoma mimicking invasive carcinoma. The presence of both benign and cytologically malignant epithelium and residual foci of lamina propria among the submucosal glands distinguishes this entity from adenocarcinoma arising in an adenomatous polyp.     

骨质疏松的药物治疗进展

◆概述 随着年龄变化,由于在维持骨骼质地、强度的塑形和重建两方面出现异常,人的骨骼逐渐变得松脆。当在妇女绝经后骨骼的重塑形速度加快,以及在成年人继发性甲状旁腺机能亢进时,骨组织中的矿物质含量减少,成熟骨被幼稚骨所替代,其强度逐渐降低。 在每一个骨骼重塑形出现不平衡的部位都可以出现骨结构的破坏。这种不平衡是由于骨吸收量的增加和较少的骨重建所造成的。在骨骼的重塑形过程中,网状结构的缺损导致皮质骨变薄、空隙增大,骨小梁变稀疏,其连接强度降低。