Elevated plasma concentrations of transforming growth factor-beta 1 in patients with unilateral ureteral obstruction

We measured plasma concentrations of TGF-beta 1 in patients with obstructive ureteral calculi and compared them with the plasma concentrations of healthy volunteers. The present study was a prospective study containing a homogenous group of patients with unilateral ureteral obstruction (UUO). The study consisted of patients with ureteral stones less than 7 mm in diameter that caused mild to moderate obstruction. All patients were referred by the emergency department of our hospital and examined between April 2003 and April 2004. The presence and characteristics of both stone and obstruction were determined by plain abdominal x-ray and gray-scale ultrasonography (US). Blood samples were collected from both patients and control individuals on admission and 1 week after conservative follow-up. The plasma TGF-beta 1 concentration was determined using a quantitative sandwich enzyme immunoassay specific for TGF-beta 1. There were 35 patients with 20 women and 15 men (average age 26.8±5.9 years), and 15 volunteers in the control group, with nine women and six men (average age 24.2±4.5 years). Average stone size was 5.6 mm±1.2 mm (range 3.5–7) for the patient group. US showed the presence of mild hydronephrosis in 24 and moderate hydronephrosis in 11 patients. Plasma concentrations of TGF-beta 1 in patients with ureteral obstruction (1,117±5.8 ng/ml, range 36–2,442 ng/ml) were significantly higher than those in the healthy control group (32±4 ng/ml) on admission (P<0.001). There was a significant increase in TGF-beta 1 plasma concentrations in the patient group (33,525±6.8 ng/ml, range 1,107–73,288 ng/ml) after 1 week follow-up (P<0.001). Ureteral obstruction increases plasma TGF-beta 1 concentrations in patients with ureteral stones as in UUO models in animal studies. A concomitant treatment with an anti-fibrotic agent may reduce the incidence of renal injury during obstruction.     

Pyridoxamine lowers oxalate excretion and kidney crystals in experimental hyperoxaluria: a potential therapy for primary hyperoxaluria

In order to prevent kidney stones and nephrolithiasis in hyperoxaluria, a new treatment that specifically reduces oxalate production and therefore urinary oxalate excretion would be extremely valuable. Pyridoxamine(PM) could react with the carbonyl intermediates of oxalate biosynthesis, glycolaldehyde and glyoxylate, and prevent their metabolism to oxalate. In PM treated rats, endogenous urinary oxalate levels were consistently lower and became statistically different from controls after 12 days of experiment. In ethylene glycol-induced hyperoxaluria, PM treatment resulted in significantly lower (by ~50%) levels of urinary glycolate and oxalate excretion compared to untreated hyperoxaluric animals, as well as in a significant reduction in calcium oxalate crystal formation in papillary and medullary areas of the kidney. These results, coupled with favorable toxicity profiles of PM in humans, show promise for the therapeutic use of PM in primary hyperoxaluria and other kidney stone diseases.     

Oxalate and its handling in a low stone risk vs a stone-prone population group

Despite hyperoxalurogenic eating habits relative to white subjects, South African blacks have urinary oxalate excretions, Tiselius risk indices (AP_CaOx) and calcium oxalate saturations, which do not differ significantly from those of their white counterparts. The present study was undertaken to establish whether the BONN-Risk-Index (BRI) might discriminate between the urines of the two population groups and whether differences might exist in their respective gastrointestinal absorption rates of oxalate. Participants (n=15 in each group) provided 24 h urines on their free diets for BRI determination. Gastrointestinal oxalate absorption was measured using the [¹³C₂]oxalate absorption test. Results showed that BRI values were significantly lower in black subjects (2.04 vs 4.90, P=0.034), but that there was no difference in the oxalate absorption between the groups (10.30 vs 9.95%, P=0.87). These results suggest that South African black subjects handle dietary oxalate more efficaciously than white subjects and that this occurs via some endogenous mechanism, which has not yet been identified or characterized.     

Analysis of the soluble organic matrix of five morphologically different kidney stones

Our aims were to analyze the protein composition of the organic matrix of urinary stones and to investigate the role of albumin in its constitution. Five different morphological types of stones were studied. Proteins extracted from the stone were submitted to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by immunoblotting with antibodies to 13 urinary proteins. Nine of the 13 proteins were found in all types of stone: human serum albumin (HSA), ₁-acid glycoprotein (₁-GP), ₁-microglobulin (₁-M), immunoglobulins (Igs), apolipoprotein A1 (apo-A1), transferrin (Tr), ₁-antitrypsin (₁-T), retinol-binding protein (RBP) and renal lithostathine (RL). The ₂-microglobulin (₂-M) was present only in calcium oxalate and uric acid stones. In contrast, ceruloplasmin, haptoglobin and Tamm-Horsfall protein (THP) were detected in none of them. Because HSA appeared as the major protein component in all stones, we wondered whether it might play a specific role in the constitution of the stone matrix. Association of HSA with urinary proteins that were present in stones was demonstrated by showing that proteins present in the matrix comigrated with HSA on gel filtration, whereas proteins that were absent did not. Moreover, HSA induced the binding of stone matrix proteins to an albumin-specific affinity column. Finally, we evidenced HSA binding to calcium oxalate monohydrate (COM) crystals in a solution similar to urine. It was concluded that (1) only a subset of urinary proteins is present in stone matrix, (2) the same proteins are found in all types of stones, (3) HSA shows significant affinity for several proteins of the matrix, but not for proteins absent from stones and, (4) HSA also displays significant affinity for COM crystals.     

Ureteral Obstruction: Is the Full Metallic Double-Pigtail Stent the Way to Go?

Background

The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo.

Objective

The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction.

Design, setting, and participants

In total, 50 patients with extrinsic malignant obstruction (n = 25), benign ureteral obstruction (n = 18), and previously obstructed mesh metal stents (n = 7) were prospectively evaluated.

Intervention

All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities.

Measurements

We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation.

Results and limitations

The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2–12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents.

Conclusions

The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study.     

Intraperitoneal Rupture of the Ureter as a Cause of Generalized Peritonitis: Report of a Case

We report a rare case of generalized peritonitis caused by nontraumatic, intraperitoneal rupture of the ureter. An 80-year-old woman with a history of bilateral vesicoureteral reflux and long-term urethral indwelling catheter drainage presented with a very distended abdomen. Computed tomography showed massive ascites and intraperitoneal free gas. We performed an emergency laparotomy, assuming a gastrointestinal perforation; but could not find a cause of generalized peritonitis. Postoperatively, she presented with anuria and massive peritoneal drainage. The findings of a cystogram confirmed intraperitoneal ureteral rupture. She was managed successfully with ureteral stenting. The diagnosis of this condition requires a high degree of clinical suspicion, along with radiographic evidence and peritoneal fluid analysis. Image-guided interventions play a crucial role in the management of ureteral urine leaks after a correct diagnosis has been made.     

Holmium:YAG laser treatment of ureteral calculi: a 5-year experience

The purpose of this study was to provide an account of the 5-year experience we have gained using holmium:yttrium–aluminium–garnet (Ho:YAG) lasertripsy in the treatment of ureteral stones. One-hundred thirty-seven transurethral ureterolithotripsies were performed in 131 patients. A Ho:YAG laser device, fibres with diameters of 360 and 550 μm, a video camera as well as semi-rigid and flexible ureterorenoscopes were used. Results showed that the direct success rates—which meant stone-free ureters on the first post-operative day—in the upper, middle and lower ureters were 84.6, 88.7 and 94.8%, respectively. The final success rates—which meant stone-free ureters 4 weeks after the operation without a second intervention—were 84.6, 96.7 and 96.7%, respectively. The pulsatile Ho:YAG laser beam fragmented all kinds of stones easily. No ureteral stricture or reflux was identified during the follow-up period. The advantages of Ho lasertripsy outweighed its disadvantages. Based on our experience, the Ho:YAG laser is one of the most effective and safest energy sources in the treatment of ureteral calculi.     

The use of risk indices: do they predict recurrence?

A risk index which would reliably predict the likelihood of stone recurrence in the patient with renal calculi would help the clinician to select appropriate preventative therapy. However, none of the indices developed to date combines easy applicability in usual clinical settings with sufficient predictive power to be useful to the clinician in making treatment decisions.     

Ablation of Diaphragmatic Annular Ureteral Valve with Holmium Laser

We report laser ablation of a diaphragmatic ureteral valve. Annular diaphragmatic ureteral valves are a rare cause of ureteral obstruction. We believe this to be the first reported case of laser ablation of a ureteral valve. Follow-up at 2 years revealed preserved renal function and unobstructed drainage.     

Corticosteroids and Tamsulosin in the Medical Expulsive Therapy for Symptomatic Distal Ureter Stones: Single Drug or Association?

OBJECTIVES: To assess the clinical role of corticosteroids in the medical expulsive therapy of symptomatic distal ureteral stones. METHODS: Between January 2004 and September 2005, 114 patients with symptomatic distal ureteral stones with a >/=5mm diameter were enrolled in this prospective study and divided into four groups based on the urologist (of four) who treated them in the emergency unit. Group A (33 patients) received tamsulosin (0.4mg daily), group B (24 patients) received deflazacort (30mg daily), group C (33 patients) received both (0.4mg tamsulosin+30mg deflazacort daily), and control group D (24 patients) received only analgesics. The treatment duration was 10 d to prevent the side-effects of prolonged corticosteroid therapy. The end points were the expulsion rate, analgesic consumption, number of ureteroscopies, and safety. RESULTS: The groups were comparable in terms of age, sex, and stone location. The stone diameter was 5.96+/-0.33mm for group A, 5.83+/-0.4mm for group B, 5.88+/-0.23mm for group C, and 5.71+/-0.5mm (p>0.05) for group D. The rates of expulsion for the four groups were 60%, 37.5%, 84.8%, and 33.3%, respectively. There was a significant difference between group C and the other groups (p<0.001). The mean analgesic consumption was 42.5+/-0.4mg for group A, 50+/-0.3mg for group B, 27.3+/-0.5mg for group C, and 81+/-0.33mg for group D, with a significant difference between group C and the other groups (p<0.001). During the treatment period, only two cases of drug side-effects related to tamsulosin (without any drop-outs) were recorded. CONCLUSION: When the medical expulsive therapy for symptomatic distal ureteral stones is considered, the use of steroids (deflazacort) proves efficient only when administered together with alpha(1)-blockers (tamsulosin). In addition, tamsulosin used on its own as a medical expulsive therapy can be considered as an alternative treatment for those patients who are not suitable for steroid therapy, as it is generally efficient.