Urine citrate and renal stone disease.

Calcium stone disease is attributable to supersaturation of the urine with calcium and other salts, the presence of substances that promote crystallization and a deficiency of inhibitors of crystallization. Citrate is a potent inhibitor of calcium oxalate and calcium phosphate stone formation whose excretion is diminished in some patients with stone disease owing to idiopathic causes or secondary factors such as bowel disease and use of thiazides. The pH within the proximal tubule cells is an important determinant of citrate excretion. Multivariate analysis has shown that the urine concentrations of calcium and citrate are the most important factors in stone formation. In uncontrolled studies potassium citrate, which increases urinary citrate excretion, appears to be promising as a therapeutic agent for patients with stone disease and hypocitraturia refractory to other treatment. On the other hand, there are potential drawbacks to sodium alkali therapy, such as the precipitation of calcium phosphates.     

Clinical comparison of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy in treating renal calculi.

STUDY OBJECTIVE: To compare extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy for efficacy in treating renal calculi. DESIGN: Non-randomised multicentre cohort study with 3 month follow up and 13 month data collection period. SETTING: Lithotripter centre in London, tertiary referral hospital, and urological clinics in several secondary and tertiary care centres. PATIENTS: 933 of 1001 patients treated by lithotripsy at the lithotripter centre were compared with 195 treated by nephrolithotomy. Missing patients were due to incomplete collection of data. Age and sex distributions and characteristics of the stones were similar in the two treatment groups. Two patients died in the lithotripsy group. Three month follow up was achieved in about 84% of both groups (783/933 for lithotripsy; 163/195 for nephrolithotomy). INTERVENTIONS: The nephrolithotomy group had surgical nephrolithotomy alone. In the lithotripsy group 83% (774/933) had lithotripsy alone, 11% (103/933) had combined lithotripsy and nephrolithotomy, and 6% (56/933) had lithotripsy plus ureteroscopy. Single and combined lithotripter treatments were analysed as one group and compared with nephrolithotomy. END POINT: Presence of stones three months after treatment. MEASUREMENTS AND MAIN RESULTS: Presence of residual stones was assessed by plain radiography, ultrasonography, or intravenous urography. After adjustment for age and size and position of stone for patients with single stones the likelihood of being free of stones three months after treatment was significantly greater in the nephrolithotomy group than the lithotripsy group (odds ratio 6.6; 95% confidence interval 3.0 to 14.6) and the response was particularly pronounced with staghorn calculi (62% (8/13) v 15% (141/96) patients free of stones after nephrolithotomy and lithotripsy, respectively). OTHER FINDINGS: 19%(146/775) of patients who had had lithotripsy had to be readmitted within three months after treatment compared with 14%(23/162) who had nephrolithotomy; and 64%(94/146) of readmissions after lithotripsy were for complications compared with 30%(7/23) of readmissions after nephrolithotomy. CONCLUSIONS: Nephrolithotomy may be preferable to lithotripsy for treating renal stones and it may not be wise to invest heavily in lithotripsy facilities.     

Elimination of active trachoma after two topical mass treatments with azithromycin 1.5% eye drops

Background

Following an epidemiological study carried out in 2006 showing a high prevalence of blinding trachoma in the Far North Region of Cameroon, a trachoma elimination programme using the SAFE strategy was initiated: three yearly trachoma mass treatments were to be performed.

Methodology/Principal Findings

The entire district population (120,000 persons) was treated with azithromycin 1.5% eye drops in February 2008 and January 2009. To assess the effect of treatment on the prevalence of active trachoma, three epidemiological studies were conducted on a representative sample of children aged between 1 and 10 years. The first study was performed just prior to the first treatment, the second just prior to the 2nd treatment and the third one, one year later. The prevalence of active forms of trachoma (TF + TI) dropped from 31.5% (95%CI 26.4–37.5) before treatment to 6.3% (95%CI 4.1–9.6) one year after first treatment; a reduction of nearly 80%. One year after the second treatment, the prevalence decreased to 3.1% (95%CI 2.0–4.9), a total reduction of 90%. Furthermore, there were no more TI cases (only TF). There was no report of serious or systemic side effects. Tolerance was excellent.

Conclusions/Significance

Active trachoma mass treatment with azithromycin 1.5% eye drops is feasible, well tolerated, and effective.     

Immunohistochemical identification of tubular segments in percutaneous renal biopsies.

To identify the renal cortical tubular segments involved in tubulo-interstitial disease in formalin-fixed, paraffin-embedded percutaneous kidney biopsies, we developed multiple immunolabeling protocols using segment-specific tubular markers. The present study of biopsies from patients with minimal change or thin basement membrane nephropathy provides a baseline for interpretation of histopathology. Proximal tubules were stained either by the PAS reaction or by the biotinylated Phaseolus vulgaris erythroagglutinin (PHA-E)-streptavidin-gold-silver system (brush borders black). The anti-Tamm-Horsfall (THP) antibody-immunoperoxidase (aminoethylcarbazole, AEC-IPO), and anti-epidermal cytokeratins (ECK) antibodies-immunoalkaline-Fast Blue BB methods marked the distal straight tubules and the cortical collecting system red-brown and blue, respectively. When these immunolabelings were combined, the coapplication of AEC-PO-labeled peanut agglutinin (PNA) or anti-epithelial membrane antigen antibody-AEC-IPO technique (both are markers for distal nephron) visualized the apical membranes of distal convoluted tubules. In the protocol PHA-E + PNA + THP + ECK, the tubular basement membranes were outlined by the anti-laminin antibody-AEC-IPO staining, carried out simultaneously. The protocol PNA + THP + ECK + PAS was found to be quite appropriate multiple immunolabeling method for the tubules, and is recommended for use as a tool in the study of tubulo-interstitial diseases.     

Characterization of a renal medium chain acyl-CoA synthetase responsible for glycine conjugation in mouse kidney mitochondria.

Glycine conjugation of a series of benzoic acid derivatives was investigated in mouse kidney mitochondria. The chlorine and methyl substitutions in the para- and meta-positions of the benzene ring yielded an increase in glycine conjugation. The acids with a methoxy group showed a low degree of glycine conjugation. In addition, the acids with nitro or amino groups were conjugated to a slight extent with glycine. The in vitro conjugation of salicylic acid with glycine occurred not in liver but in kidney. The specificity of the renal medium chain acyl-CoA synthetase catalyzing the first reaction of glycine conjugation was also examined. The enzyme accepted not only medium chain fatty acids but also aromatic and arylacetic acids. The highest activity was shown with hexanoic acid. High activities were observed for benzoic acid derivatives with alkyl and alkoxyl groups in the para- and meta-positions of the benzene ring. An ortho-substituted acid exhibited no activity. In addition, the enzyme was less active with valproic acid, tranexamic acid, indomethacin and ketoprofen. The enzyme was inhibited by diflunisal, 2-hydroxydodecanoic acid and salicylic acid, which did not act as substrates. There was a poor correlation between the activity of the medium chain acyl-CoA synthetase and glycine conjugation of eleven substituted benzoic acids. These findings suggest that the present medium chain acyl-CoA synthetase is involved in glycine conjugation of the substituted acids in mouse kidney mitochondria, but there may be a larger contribution of another isoenzyme.     

B超引导经皮肾镜气压弹道联合超声碎石术治疗开放手术后复发肾结石

目的:探讨B超引导经皮肾镜气压弹道联合超声碎石术治疗开放手术后复发肾结石的可行性与疗效.方法:对46例开放手术后复发肾结石患者施以经皮肾镜气压弹道联合超声碎石术治疗,其中全鹿角状结石13例,部分鹿角状结石26例.多发性结石7例.结果:46例手术均成功,平均手术时间92rain;30例一期取净结石(65.2%),5例因穿刺出血仅建立经皮肾通道,12例接受二期PCNL,术后结石清率82.6%.7例术后发热,2例需要输血,1例气胸,经保守治疗均好转.结论:经皮肾镜气压弹道联合超声碎石术治疗开放手术后肾结石创伤小、并发症少、恢复快、结石清除率高,可以作为开放手术后复发肾结石的首选治疗方案.     

Sodium gradient dependence of proline and glycine uptake in rat renal brush-border membrane vesicles.

The sodium-dependent entry of proline and glycine into rat renal brush-border membrane vesicles was examined. The high Km system for proline shows no sodium dependence. The low Km system for glycine entry is strictly dependent on a Na+ gradient but shows no evidence of the carrier system having any affinity for Na+. The low Km system for proline and high Km system for glycine transport appear to be shared. Both systems are stimulated by a Na+ gradient and appear to have an affinity for the Na+. The effect of decreasing the Na+ concentration in the ionic gradient is to alter the Km for amino acid entry and, at low Na+ concentrations, to inhibit the V for glycine entry.     

Treatment of Bowen disease using the ultrasonic surgical aspirator.

In most cases, patients with Bowen disease lesions can be easily treated by surgical excision and direct closure; however, the ultrasonic surgical aspirator, an instrument in common use in many fields, offers a good treatment alternative with few drawbacks for patients with lesions that are large and/or located in joint areas, areas that are hard to heal, or areas that are surgically problematic such as the ears, nose, eyelids, and mucous membranes. The clinical application of the ultrasonic surgical aspirator in the treatment of Bowen disease promises considerable benefit in terms of patient comfort because removal of the lesion is easy, is noninvasive, and does not require hospitalization or result in restricted mobility. All of these factors, although benefiting patients, particularly the elderly, can also substantially lower the cost of treatment.