The Urine Albumin-to-Creatinine Ratio and Kidney Function after Nephrectomy.

PURPOSE: Patients with kidney cancer are at risk for chronic kidney disease after radical and partial nephrectomy. We determined if the urine albumin-to-creatinine ratio is independently associated with progressive chronic kidney disease after nephrectomy. MATERIALS AND METHODS: We performed a cohort study based within a large, integrated health care system. We identified patients who underwent radical or partial nephrectomy from 2004 to 2014 with urine albumin-to-creatinine ratio measured in the 12 months before surgery. We fit multivariable models to determine if the urine albumin-to-creatinine ratio was associated with the time to chronic kidney disease progression (defined as reaching stage 4 or 5 chronic kidney disease, estimated glomerular filtration rate less than 30 ml/minute/1.73 m2). We performed a parallel analysis measuring the time to stage 3b, 4 or 5 chronic kidney disease (estimated glomerular filtration rate less than 45 ml/minute/1.73 m2) among patients with normal or near normal preoperative kidney function (estimated glomerular filtration rate 60 ml/minute/1.73 m2 or greater). We also examined the association between urine albumin-to-creatinine ratio and survival. RESULTS: A total of 1,930 patients underwent radical or partial nephrectomy and had preoperative urine albumin-to-creatinine ratio and preoperative and postoperative estimated glomerular filtration rate. Of these patients 658 (34%) and 157 (8%) had moderate (urine albumin-to-creatinine ratio 30 to 300 mg/gm) or severe albuminuria (urine albumin-to-creatinine ratio greater than 300 mg/gm), respectively. Albuminuria severity was independently associated with progressive chronic kidney disease after radical (moderate albuminuria HR 1.7, 95% CI 1.4-2.2; severe albuminuria HR 2.3, 95% CI 1.7-3.1) and partial nephrectomy (moderate albuminuria HR 1.8, 95% CI 1.2-2.7; severe albuminuria HR 4.3, 95% CI 2.7-7.0). Albuminuria was also associated with survival following radical and partial nephrectomy. CONCLUSIONS: In patients undergoing radical or partial nephrectomy the severity of albuminuria can stratify risk of progressive chronic kidney disease.

The Effect of Calcium and Vitamin B6 Supplementation on Oxalate Excretion in a Rodent Gastric Bypass Model of Enteric Hyperoxaluria.

OBJECTIVE: To test the effect of calcium and vitamin B6 therapies on urinary oxalate excretion in a rodent model of enteric hyperoxaluria after Roux-en Y gastric bypass (RYGB) surgery. METHODS: Obese male Sprague-Dawley rats underwent sham (n = 7) or RYGB (n = 10). Animals were maintained on low oxalate (1.5%) and fat (10%; LOF), normal calcium (0.6 %) diet for 8 weeks and then completed a 2-phase crossover metabolic study. In the first 2-week phase, animals were fed a Low oxalate and fat (LOF), high calcium (2.4%; HC) diet. After a 2-week washout, rats were fed a LOF/normal calcium diet highly enriched with vitamin B6. Urine was collected before and after each intervention. Plasma pyridoxal 5'-phosphate (PLP) and metabolites were measured baseline and 11 weeks after sham or RYGB. RESULTS: Compared to baseline, sham animals on LOF/HC diet doubled their urinary calcium excretion but not oxalate. RYGB animals on LOF/HC diet decreased urinary oxalate excretion 28% (P = .001) without a significant rise in urinary calcium. Vitamin B6 supplementation decreased RYGB urinary oxalate by approximately 15% (P = .06), and serum PLP explained 63% of urinary oxalate variability. CONCLUSION: Based on the findings in this model, calcium supplementation appears to be a reasonable therapy to decrease urinary oxalate in RYGB patients who maintain a low fat and oxalate diet. Serum PLP had a fair correlation to urinary oxalate excretion and may be a useful screening tool in hyperoxaluric RYGB patients. Further experimental human studies after RYGB are necessary to determine whether these commonly employed supplements truly provide a benefit in enteric hyperoxaluria.

Nerve Growth Factor Levels are Associated with Overactive Bladder Symptoms and Long-Term Treatment Outcome after Transurethral Resection of the Prostate in Patients with Benign Prostatic Hyperplasia.

PURPOSE: We investigated changes in urinary nerve growth factor in patients with benign prostatic hyperplasia after transurethral prostate resection. We also assessed the association between nerve growth factor and changes of overactive bladder symptoms and long-term treatment outcomes after surgery. MATERIALS AND METHODS: This was a prospective study of 178 patients at Peking University People's Hospital with benign prostatic hyperplasia between January 2011 and January 2013. Urinary nerve growth factor levels were determined preoperatively using a commercial enzyme-linked immunosorbent assay kit. We also determined prostate volume, I-PSS (International Prostate Symptom Score), quality of life, OABSS (Overactive Bladder Symptom Score), ultrasound estimated post-void residual urine and urodynamics before surgery. Urinary nerve growth factor levels, I-PSS and OABSS were assessed again 1 year after transurethral prostate resection. RESULTS: Urinary nerve growth factor/creatinine levels differed between patients with moderate and severe lower urinary tract symptoms (mean ± SD 10.513 ± 4.255 vs 12.334 ± 4.048 pg/µmol, p = 0.002). There was no significant difference between patients with grades III/IV and V/VI bladder outlet obstruction (mean 11.285 ± 4.069 vs 11.781 ± 4.437 pg/µmol, p = 0.354). However, differences were significant for urinary nerve growth factor/creatinine levels in patients without overactive bladder, and mild, moderate and severe overactive bladder (mean 8.132 ± 3.489, 10.128 ± 3.817, 13.232 ± 3.290 and 14.029 ± 3.820 pg/µmol, respectively, p <0.001). One year after transurethral prostate resection we noted a decrease vs baseline in mean urinary nerve growth factor/creatinine (8.978 ± 4.022 pg/µmol, p <0.001), and I-PSS and OABSS (10.2 ± 5.4 and 4.3 ± 3.7, respectively, each p <0.001). Compared with the good outcome group, the fair/poor group had higher mean baseline urinary nerve growth factor/creatinine (12.319 ± 4.017 vs 11.015 ± 4.298 pg/µmol, p = 0.045), higher mean 1-year urinary nerve growth factor/creatinine (10.847 ± 4.267 vs 7.850 ± 3.419 pg/µmol, p <0.001) and a lesser mean postoperative change in urinary nerve growth factor/creatinine (1.472 ± 4.928 vs 3.165 ± 4.863 pg/µmol, p = 0.031). CONCLUSIONS: Nerve growth factor was associated with overactive bladder symptoms in patients with benign prostatic hyperplasia as well as with the assessment of successful long-term treatment outcome of bladder outlet obstruction with symptoms of overactive bladder.

Enteric hyperoxaluria secondary to small bowel resection: use of computer simulation to characterize urinary risk factors for stone formation and assess potential treatment protocols.

BACKGROUND AND PURPOSE: We used computer modeling to investigate the influence of physicochemical stone risk factors on urinary supersaturation (SS) of calcium oxalate (CaOx) in patients with severe hyperoxaluria, relative hypocalciuria, hypocitraturia, and CaOx nephrolithiasis after extensive small bowel resection, usually performed for Crohn's disease. We also simulated different treatment strategies, including oral calcium supplements and citrate, in such patients. MATERIALS AND METHODS: A baseline urine model was derived by consolidating data acquired by ourselves with those from another patient cohort. Calcium and oxalate excretions in this model were altered to obtain an extreme case. For comparison, additional models were based on published urine data from normal subjects (N) and idiopathic CaOx stone formers (SF). The Joint Expert Speciation System was used to simulate different urine situations based on reported compositional values. RESULTS: [Ca(2+)][Ox(2-)] ionic concentration products and SS(CaOx) are substantially higher in enteric hyperoxaluric patients than in N and SF, despite their relatively lower calcium excretions. Molar Ca:Ox ratios are substantially lower in enteric hyperoxalurics than in N and SF. Oral calcium supplements can reduce SS(CaOx), but monitoring is required to avoid exceeding a safe dosing threshold. A simple calculation can alert the clinician that this threshold is being approached or even exceeded. Increasing urinary pH and citrate decreases SS(CaOx) but not to the same extent as decreasing Ox excretion. CONCLUSIONS: Calcium supplements can help reduce stone risk in patients with severe enteric hyperoxaluria, but initial efforts should be directed toward reducing urinary oxalate by reducing dietary oxalate. Citrate therapy that increases both urine pH and urinary citrate provides an additional therapeutic benefit.

Interstitial laser coagulation for benign prostatic hyperplasia: preliminary clinical results.

We report our early experience in the clinical application of interstitial laser coagulation of the prostate (ILCP) in the treatment of benign prostatic hyperplasia (BPH). Neodymium: YAG laser energy is transmitted via a specially designed interstitial thermotherapy light-guide. The light guides were inserted transurethrally into each lobe of the prostate by direct puncture, under direct visualization. The prostatic urethra is preserved during the procedure. From December 1993 to March 1994, 37 patients with symptomatic BPH were treated with ILCP. Treatment outcome was evaluated by the International Prostatic Symptom Score (I-PSS), flow rate, postvoided residual urine volume and quality of life score. Significant improvement in I-PSS and peak flow rate was observed at 3 months: I-PSS decreased from a mean of 19.3 to 10.4, and the peak flow rate increased from a mean of 7.2 to 9.4 ml/sec (p < 0.0001). The mean postvoided residual urine volume significantly decreased from 91 to 47 ml (p < 0.01). Two days after ILCP the serum prostate-specific antigen had increased by 860%, evidence of the significant tissue damage produced by laser irradiation. The quality of life score significantly decreased from a mean of 4.8 to 2.1 (p < 0.0001). No serious side-effects were observed. The early clinical results suggest that ILCP is safe and effective as a treatment of BPH and is less invasive than some other methods.

[Effects of intermittent muscle stimulation on muscle catabolism in patients immobilized in the ICU]. / Effets des stimulations musculaires intermittentes sur le catabolisme musculaire des malades immobilisés en réanimation.

Are muscular contractions obtained by electrical stimulation able to reduce muscle catabolism in immobilized patients? Ten patients (65 to 79 yr old), hospitalized in an intensive care unit for postoperative failure or cerebral infarction, were studied during nine days. Artificial nutrition was the same for each patient during the study. Two periods of four days where defined and randomized for each patient, separated by one day; during the stimulation period (S), intermittent electrical stimulation of the muscles of the legs (external electrodes) was performed daily 2 X 30 min; during the non-stimulation period (NS), muscular stimulation was not performed. Urinary excretion of nitrogen (micro-Kjeldhal digestion and Nessler procedure), creatinine (Jaffé reaction) and 3-methylhistidine were measured every day. Results (X +/- SD) are as follows: the nitrogen balance (g/d) was -1.29 +/- 1.26 during the NS period and 1.43 +/- 1.10 during the S period (NS); 3-methylhistidine (mumol/kg/d) was 3.78 +/- 0.37 during the NS period and 3.15 +/- 0.32 during the S period (p less than 0.01); creatinine (mumol/kg/d) was 92.9 +/- 6.8 during the NS period and 72.9 +/- 25 during the S period (p less than 0.01). It is concluded that a significant decrease in 3-methylhistidine and creatinine excretions is observed during the S period. In intensive care unit patients, muscle protein breakdown may be influenced by intermittent electrical muscle stimulation.