RESUMEN

Pregnancy may increase signs of renovascular stress. We compared pregnant sham operated (S) and 5/6 nephrectomy (NX) rats to examine the effect of pregnancy on reduced nephron number. Blood pressure (BP), heart rate (HR), body weight (BW), food/water intake, serum creatinine (Cr), urinalyses were assessed weekly, and end pregnancy renal histology examined. NX showed decreased BW, elevated BP and Cr, and proteinuria. Histology revealed increased glomerular volume, increased tubular diameter and interstitial inflammation and fibrosis. This pilot shows that a pregnant 5/6th nephrectomy rat is a reliable model in which to evaluate renovascular stress with reduced nephrons.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

Timely and accurate identification and determination of the antimicrobial susceptibility of uropathogens is central to the management of UTIs. Urine dipsticks are fast and amenable to point-of-care testing, but do not have adequate diagnostic accuracy or provide microbiological diagnosis. Urine culture with antimicrobial susceptibility testing takes 2-3 days and requires a clinical laboratory. The common use of empirical antibiotics has contributed to the rise of multidrug-resistant organisms, reducing treatment options and increasing costs. In addition to improved antimicrobial stewardship and the development of new antimicrobials, novel diagnostics are needed for timely microbial identification and determination of antimicrobial susceptibilities. New diagnostic platforms, including nucleic acid tests and mass spectrometry, have been approved for clinical use and have improved the speed and accuracy of pathogen identification from primary cultures. Optimization for direct urine testing would reduce the time to diagnosis, yet these technologies do not provide comprehensive information on antimicrobial susceptibility. Emerging technologies including biosensors, microfluidics, and other integrated platforms could improve UTI diagnosis via direct pathogen detection from urine samples, rapid antimicrobial susceptibility testing, and point-of-care testing. Successful development and implementation of these technologies has the potential to usher in an era of precision medicine to improve patient care and public health.

Asunto(s)

Asunto(s)

RESUMEN

PURPOSE: Renal dimensions are an important assessment of the genitourinary tract used to evaluate critical aspects of renal growth and development. Understanding the effect of patient position is important to use and interpret these parameters. In this prospective study we determined the effect of patient position and general body habitus on renal length and parenchymal area in children undergoing renal ultrasound. MATERIALS AND METHODS: Between October 2010 and January 2011 children underwent renal ultrasound while prone and supine. Bilateral renal length and renal parenchymal area were measured. Pearson and Bland-Altman statistical analyses were used to examine correlations, measurement bias and the degree of agreement between methods. RESULTS: Renal length measurements in both positions were complete for 201 right and 196 left kidneys. Parenchymal area measurements were complete for both kidneys in 177 children. When compared individually, supine and prone measures of renal length and parenchymal area highly correlated on Pearson analysis (greater than 0.96 and greater than 0.89, respectively). When compared by method, Bland-Altman analyses of differences vs means showed greater than 50% variance, representing wide limits of agreement with poor interrelation. Neither persistent systematic bias nor body habitus influenced results. CONCLUSIONS: While Pearson analysis showed high correlation for supine and prone renal measurements, Bland-Altman analysis of renal length and parenchymal area demonstrated wide limits of agreement, not allowing interchangeable use of prone and supine measurements. As such, renal ultrasound should specify standardized positions and benchmarks. These results provide guidance to standardize renal ultrasound measurements when renal size is used as an indicator of kidney health.

Asunto(s)

RESUMEN

PURPOSE: The incidence of pregnancies complicated by hyperglycemia and hypertension is increasing along with associated morbidities to mother and offspring. The high fructose diet is a well-studied model that induces hyperglycemia and hypertension in male rodents, but may not affect females. We hypothesized that the physiologic stress of pregnancy may alter metabolic responses to dietary fructose. MATERIALS AND METHODS: In this study female Sprague-Dawley rats were divided into two gestational dietary groups: (1) 60% carbohydrate standard rat chow (Pregnant-S-controls) and (2) 60% fructose enriched chow (Pregnant-F). Body weight, blood pressure, blood glucose, triglycerides, and insulin were measured in pregnancy and during the post-partum period. Maternal organ weight and histological changes were also assessed after delivery. RESULTS: By midpregnancy Pregnant-F rats had increased weight, elevated blood pressure, higher fasting glucose, and elevated triglycerides compared with Pregnant-S rats. Both groups demonstrated elevated gestational insulin levels with signs of insulin resistance (increased HOMA-IR). Pregnant-F rats showed significant histopathologic hepatic steatosis and renal tubular changes characterized by tubular dilation and glomerulosclerosis. CONCLUSION: Our study provides a model in which dietary change during pregnancy can be examined. We demonstrate, moreover, that high dietary fructose ingestion in pregnant rats may result in profound systemic and pathologic changes not appreciated during routine pregnancy.

Asunto(s)

RESUMEN

PURPOSE: Testosterone affects male development, maturation and aging but limited data exist on testosterone effects on the juvenile genitourinary system. We hypothesized that testosterone has bladder and kidney developmental effects, and investigated this in juvenile male rats. MATERIALS AND METHODS: To examine the testosterone effect 21-day-old prepubertal male Wistar rats were divided into 3 groups of 12 each, including sham orchiectomy as controls, and bilateral orchiectomy with vehicle and bilateral orchiectomy with testosterone. Starting at age 28 days (week 0) testosterone enanthate (5 mg/100 gm) or vehicle was injected weekly. Testosterone was measured at study week 0 before injection, and at weeks 1, 6 and 16. Whole bladders and kidneys were evaluated for androgen receptor, bladder collagen-to-smooth muscle ratio, and renal morphometry and immunohistochemistry. RESULTS: Testosterone was not detectable at week 0 in all groups. It remained undetectable at weeks 1, 6 and 16 in the orchiectomy plus vehicle group. Testosterone levels were physiological in controls and rats with orchiectomy plus testosterone but levels were higher in the latter than in the former group. Rats with orchiectomy plus testosterone had increased bladder-to-body and kidney-to-body weight ratios (p<0.01 and <0.05, respectively), and decreased collagen-to-smooth muscle ratio than the orchiectomy plus vehicle and control groups. Rats with orchiectomy plus testosterone had a lower renal total glomerular count (p<0.01) but increased androgen receptor density. CONCLUSIONS: In juvenile male rats testosterone was associated with increased bladder and renal mass, and increased bladder smooth muscle. Testosterone associated kidneys also appeared to have fewer but larger glomeruli. These data support an important role for sex hormones in structural and functional development of the bladder and kidney.

Asunto(s)

RESUMEN

PURPOSE: To create a reliable rat model with small renal cortical scars and evaluate the accuracy and sensitivity of dynamic contrast-enhanced MRI in detecting the kinds of lesions that are associated with reflux nephropathy. MATERIALS AND METHODS: In 16 rats, three unilateral renal cortical lesions were created using either electrocautery or pure alcohol with the contralateral kidney serving as control. MRI on a 1.5 Tesla GE Signa was performed 10-14 days after surgery. After bolus injection of 0.2 mM/Kg Gd-DTPA, sequential MRI acquisitions were performed using a 4-inch quadrature birdcage coil. Renal and scar volumes and pathology were compared after scanning and killing. RESULTS: Of the 48 points of injury, 40 (83%) in the 16 rats were detected grossly. Under microscopy, 36 injuries (75%) were detected on mid-kidney cross-sections. The average lesion was 4.2 mm(3) corresponding to 0.5% of the kidney volume. Using pathological findings as the gold standard, the sensitivity and specificity of scar detection using MRI was 69% and 93%, respectively. CONCLUSION: A rat model was created to demonstrate the sensitivity of dynamic contrast-enhanced MRI for detecting renal scars. Alcohol and electrocautery created reliable renal scars that were confirmed pathologically. MRI detected these lesions that averaged 4.2 mm(3) (0.5% total renal volume) with sensitivity and specificity of 69% and 93%, respectively.

Asunto(s)

RESUMEN

The process of certification, recertification, and maintenance of certification is mandated by the American Board of Urology as a member Board of the American Board of Medical Specialties. The history of maintenance of certification parallels that of private regulation of medical schools and postgraduate medical education (residency) and other nonmedical areas in which public trust is involved. Current trends in information technology that allow data gathering that measure medical practice and recognition of failure mandate that urologists practice with current knowledge. This will be documented in the maintenance of certification process.

Asunto(s)

RESUMEN

Wilms tumor is the most common renal malignancy in children. In the 1930s, overall survival for children with Wilms tumor was approximately 30%. Use of multidisciplinary therapy, guided by results from multi-institutional, randomized trials, has substantially improved overall survival to about 90%. Management of Wilms tumor differs substantially between Europe and the US. In Europe, the International Society of Pediatric Oncology protocols call for management of patients with presumptive Wilms tumor with neoadjuvant chemotherapy followed by nephrectomy and further chemotherapy. In the US, protocols developed by the National Wilms Tumor Study Group advise primary nephrectomy followed by a chemotherapy regimen tailored to the pathologic tumor stage. Despite these disparate strategies, overall survival is similar in patients managed according to European and US protocols. Patients with Wilms tumor now have excellent survival. Therefore, current goals aim to reduce the morbidity associated with therapy. Important complications of treatment for Wilms tumor include cardiomyopathy, renal failure, and increased risk of a secondary malignancy. Currently, the role of laparoscopic surgery in management of Wilms tumor remains extremely limited.

Asunto(s)

RESUMEN

BACKGROUND: A 17-year-old male, with a history of bladder augmentation enterocystoplasty 7 years earlier, presented with nausea, emesis and acute abdomen. INVESTIGATIONS: Physical examination, blood and urine culture, and abdominal and pelvic CT cystography. DIAGNOSIS: Acute abdomen from perforation of bladder augmentation. MANAGEMENT: Support and stabilization, bladder decompression, and broad-spectrum intravenous antibiotics, followed by immediate exploratory laparotomy with repair of enterocystoplasty and peritoneal lavage.

Asunto(s)

RESUMEN

OBJECTIVE: To evaluate the effects of oestrogen, progesterone and pregnancy on bladder dynamics, and assess the associated histological and structural changes in the bladder wall in a rat model. MATERIALS AND METHODS: Adult female Sprague-Dawley rats were divided into groups and treated as follows: nonpregnant controls (NC); pregnant (PG); oophorectomized and treated with oestrogen (ES); oophorectomized and treated with progesterone (PR); and oophorectomized controls (OO). Simultaneous and continuous renal pelvic and bladder pressures were recorded during bladder filling and emptying. Connective tissue and smooth muscle were analysed morphometrically and quantitatively, and immunohistochemistry used to evaluate the distribution and expression of collagen types I, III and IV. RESULTS: PG rats had significantly greater bladder compliance than NC, OO and PR rats (P < 0.05). This correlated with the morphometric analysis, with bladders of PG and PR rats having lower connective tissue to smooth muscle ratios than NC, ES and OO rats (P < 0.05). Collagen I was increased in the lamina propria of PG and ES rats, and the detrusor muscle layer showed greater localization of collagen III in the interfascicular space in the PG and PR rats than in the other groups. There was no change in the distribution of collagen IV. CONCLUSION: PG and PR rats had the highest bladder compliance and the changes paralleled structural changes in the bladders, specifically in the ratio of connective tissue to smooth muscle, and the distribution and expression of collagens I and III. These changes have age-related implications in the urinary tract.

Asunto(s)

RESUMEN

The urinary tract is a relatively common site of infection in infants and young children. Urinary tract infection (UTI) may result in significant acute morbidity, as well as longterm medical complications. Recent advances elucidating the pathogen-host interaction have broadened the understanding of the pathogenesis and clinical progression of pediatric UTI. This article focuses on the epidemiology and pathogenesis of pediatric UTI, and briefly discusses UTI-related complications.

Asunto(s)

RESUMEN

OBJECTIVES: When a partially obstructed kidney becomes infected, more rapid and extreme renal parenchymal damage appears to occur than might result from either infection or obstruction alone. Previously, we showed that either bacteriuria or partial obstruction in congenital unilateral hydronephrosis causes elevated renal pelvic pressures in a rat model. In this same model, we examined the combined effects of partial upper tract obstruction and bacteriuria on renal pelvic and bladder pressures. METHODS: Female rats from an inbred colony in which more than one half are born with unilateral obstructive hydronephrosis were studied. Type 1 piliated Escherichia coli was instilled into the bladder. Two to 6 days later, the bladder and renal pelvic pressures were measured during varying urinary flows (less than 2 to more than 30 mL/kg/hr). All animals were killed and the kidneys and bladder grossly and histologically assessed. Hydronephrosis was determined at pathologic examination. RESULTS: Eight rats had congenital unilateral hydronephrosis; five were normal. Acute inflammation was found in all bladder and renal specimens. In hydronephrotic, infected kidneys, the renal pelvic pressures exceeded those in nonhydronephrotic, infected kidneys at all urinary flow rates. Bladder capacity and pressures did not differ between the two groups. CONCLUSIONS: This model demonstrates that the combination of infection and obstructive hydronephrosis in this model causes renal pelvic pressure elevation that is higher than that associated with either infection or obstructive hydronephrosis alone. These data demonstrate the compound effect that infection and obstruction may have on the kidney and offers an explanation for why this clinical situation is more likely to be associated with greater renal parenchymal injury than either alone.

Asunto(s)

RESUMEN

PURPOSE: Few quantitative parameters allow for comparison of serial studies in children with prenatally detected genitourinary abnormalities. We establish the first ultrasonographically based fetal renal parenchymal growth curve that could serve as a standard for fetal renal growth assessment. MATERIALS AND METHODS: Longitudinal ultrasounds of 246 normal fetal kidneys from 16 to 38 weeks of gestation were scanned with renal parenchymal area calculated and growth curves plotted. Our previously determined nomogram from birth to adolescence was then combined with this fetal nomogram to produce a composite renal growth curve. Data were plotted as mean parenchymal area +/- 2 SD using lines determined by polynomial regression. RESULTS: Renal growth curves were constructed independently for the right and left fetal kidneys as well as the total fetal renal parenchymal area. The polynomial regression equation for the right renal parenchymal area was y = -0.0076x(2) + 0.7141x - 8.5344 (r(2) = 0.91). The polynomial regression equation for the left renal parenchymal area was y = -0.0036x(2) + 0.5161x - 6.2337 (r(2) = 0.96). The polynomial regression equation for the total fetal renal parenchymal area was y = -0.0113x(2) + 1.234x - 14.814 (r(2) = 0.95). CONCLUSIONS: We propose a new quantitative standard to evaluate appropriate fetal kidney size the prenatal renal parenchymal area growth curve. Renal parenchymal growth curves for the normal fetal kidney may serve as a valuable tool to assess fetal renal pathology.

Asunto(s)

RESUMEN

Girls with incontinence may have minor irritative conditions or undiagnosed anatomic abnormalities that may require surgery. These abnormalities can be identified during a comprehensive history and physical examination that focuses on voiding signs and symptoms. Urinary tract infection and constipation if present should be identified. Most girls with daytime wetting will respond to conservative therapy using timed voiding, dietary changes, and anticholinergic medication. Uroflowmetry with a postvoid residual urine measurement can identify girls who may benefit from biofeedback to treat pelvic floor dysfunction. Formal urodynamics and spinal magnetic resonance imaging should be done in girls refractory to treatment. Instruments and tools to quantify dysfunctional voiding symptoms are being developed. Because most dysfunctional voiding will be treated clinically, these validated tools will be useful in documenting severity of symptoms and clinical outcomes.

Asunto(s)

RESUMEN

Urinary tract infections (UTIs) are common and generally benign conditions among healthy, sexually active young women without long-term medical sequelae. In contrast, UTIs are more complicated among those individuals at either end of the age spectrum: infants/young children and geriatrics. UTI in children younger than 2 years has been associated with significant morbidity and long-term medical consequences, necessitating an extensive and somewhat invasive imaging evaluation to identify possible underlying functional or anatomic abnormalities. Pediatric UTI should be considered complicated until proved otherwise, and treatment should reflect the severity of signs and symptoms. Management in the acutely ill child frequently involves parenteral broad-spectrum antimicrobial agents, and less ill children can be treated with trimethoprim- sulfamethoxazole (TMP-SMX), beta-lactams, and cephalosporins.UTI among older patients (>65 years) may be complicated by comorbidities, the baseline presence of asymptomatic bacteriuria, and benign urinary symptoms that can complicate diagnosis. The etiology of UTI encompasses a broader spectrum of infecting organisms than is seen among younger patients and includes more gram-positive organisms. Symptomatic UTI is generally more difficult to treat than among younger populations. Management should be conservative, of longer treatment durations, and cover a broad spectrum of possible uropathogens. Oral or parenteral treatment with a fluoroquinolone for 7 days is the preferred empiric approach. TMP-SMX can also be considered a first-line agent in women only, but only if the pathogen is known to be TMP-SMX sensitive.

Asunto(s)

RESUMEN

The authors have prospectively documented that men who undergo orthotopic bladder substitution more frequently experience bacteriuria than do normal men [19] or men with carcinoma of the prostate scheduled to have radical prostatectomy (see Table 1). Because the frequency of bacteriuria in men after prostatectomy was also lower than that after orthotopic bladder substitution (see Table 1), removal of the prostate and any of its presumed antibacterial properties probably does not account for this difference. Furthermore, the authors' data (see Table 5 ) and that of Woodside and associates [23] demonstrate that intestine incorporated into the genitourinary tract generates a local antibody response against urinary bacteria. Although others have suggested that the incorporation of bowel in the urinary tract may be associated with increased bacteriuria, this effect has never been documented prospectively. The mechanism of this increased frequency of bacteriuria is unknown. Because the anatomy of the male secretory genitourinary system may be altered after radical prostatectomy and orthotopic bladder substitution, the authors evaluated local antibody production before and after these operations. More than 20 years ago, Burdon [5] found that the initial portion of the VB1 sample in men had significantly higher levels of IgA compared with the VB2 specimen, whereas the levels of IgG were similar in the two portions. This latter finding was confirmed by Shorliffe and co-workers [22] when they examined prostatic secretion. Other investigators have found high levels of IgA in human prostatic tissue and fluid. [24,25]. On the basis of these findings, it was believed that, in men, the prostate produces most of the urinary IgA, whereas the bladder or upper urinary tracts make most of the urinary IgG. Although the authors' study confirms that most local urinary tract IgG is produced by the bladder or upper urinary tracts, this study documents that the prostate is not the only source of urethral IgA in men. Despite almost complete removal or prostate secretory epithelium by radical prostatectomy, as evidenced by a dramatic fall in postoperative VB1 and VB2 PSA compared with preoperative levels (Table 3). men who had this operation had only slightly decreased IgA levels after the operation (Table 4, Fig I). The source of this IgA must be urethral because the VB1 urinary stream contains more IgA than the VB2 urine even after radical prostatectomy. The authors have not determined whether the urinary IgA concentrations observed after radical prostatectomy are the true baseline values for a man without a prostate, or whether they actually reflect abnormal production of local IgA stimulated by radical prostatectomy. Because post-prostatectomy bacteriuris occurred frequently during urethral catheter drainage, the authors screened for postoperative IgA titers to mix 1 and mix 2 to determine whether specific production of antibody against gram-negative organisms might account for some of the postoperative IgA measured. Postradical prostatectomy mix 1 and mix 2 titers were not elevated, compared with preoperative measurements. Because urethral glandular tissue other than prostatic tissue is present in the male urethra, these glands also might be responsible for significant local antibody production. The high levels of urinary IgA and IgG after cystoprostatectomy with ileal orthotopic bladder substitution document that intestine incorporated into the urinary tract is still capable of producing local antibody. This observation corresponds with the findings of Mansson and associated [26] of elevated IgA and IgG in ileal reservoir urine compared with normal urinary tracts. It has been estimated that 1 m of intestine may secrete up to 780 mg/d of IgA [27], indicating that normal intestine production of antibody alone can account for the high IgA and IgG levels found in the patients who underwent bladder substitution. Interestingly, the ratio of IgA to IgG concentration in smal intestine fluid is 2:129, similar to the ratio of IgA to IgG in bladder substitution urine (2.92.1:52, Table 4). Because mix 1 and mix 2 IgA concentrations were elevated in VB1 and VB2 urine after ileal bladder substitution (see Table 5), some of this antibody was produced by the ileal bladder substitution in response to the inevitable bacteriuria that occurs during the prolonged postoperative catheter drainage. The findings is absent after radical prostatectomy alone. In addition, some of this increased antibody might be a result of the increased bacteriuria noted in the patients who underwent ileal bladder substitution after the initial postoperative period. The significance of the increased bacteriuria and elevated antibody levels after ileal bladder substitution is unclear. Because most of these episodes of bacteriuria were asymptomatic, whether they represent clinical infections that should be treated is not known. Bishop and associates [28] found that the bacterial flora of ileal conduits with asymptomatic bacteriuria had bacterial counts of 1000 or fewer colonies, and they noted that the healthy ileum in situ may contain more than 10,000 organisms per milliliter [29]. Because the normal urinary tract is usually sterile, it is possible that the bacteriuria found by the authors after ileal bladder substitution represents some form of bowel colonization more commonly associated with the bowel rather than clinical urinary tract infection and has limited clinial importance. Trinchieri and associated [30] found that urinary from patients with ileocystoplasty prevented attachment of E. coli to human uroepithelial cells more effectively that urine from patients with recurrent urinary infections. This observation suggests that the relatively large quantities of Iga produced by the ileal bladder substitution may, in fact, prevent clinical infection by preventing tissue invasion by the bacteria. Only long-term follow-up of patients with ileocystoplasty or ileal bladder substitution will determine the clinical significance of the bacteriuria. The authors' study had documented an increased incidence of bacteriuria in men after ileal bladder substitution and no such increase after radical prostatectomy. Analysis of the data shows that male sources other than the prostate--probably urethral glands-- must produce significant quantities of local urinary tract IgA. After ileal bladder substitution, the incorporated ileum may produce volumes of local antibody that may exceed the amounts ordinarily produce by the normal urinary tract. The clinical significance of the increased incidence of bacteriuria and elevated antibody levels in patients after illeal bladder substitution is unclear.

Asunto(s)