RENAL FUNCTION TESTS IN NONACUTE RECURRENT URINARY TRACT INFECTIONS IN CHILDREN

The clinical value of various renal function tests in recurrent urinary tract infections in children has been examined. The study also includes an evaluation of glomerular capacity versus tubular capacity in recurrent urinary tract infections. There was no good correlation between blood urea nitrogen concentration and serum creatinine concentration within the normal limits for these two parameters. When blood urea nitrogen concentration and/or serum creatinine concentration were elevated, a highly significant correlation between the two parameters was found. When relating blood urea nitrogen concentration to the clearance of inulin an elevation of blood urea nitrogen concentration was not found until the filtration rate was below 50 ml/min/1.73 m² b.s. The tubular functions were examined by studies of (a) the concentrating capacity, (b) the diluting capacity, (c) sodium reabsorption and id) renal acid-base regulation. The concentrating capacity was determined by two screening tests, maximal urine osmolality after 19 hours of fluid and food deprivation with or without injection of pitressin tannate, and by free water reabsorption. The administration of exogenous pitressin had no significant effect on maximal urine osmolality. There was a highly significant correlation between free water reabsorption and maximal urine osmolality. A highly significant correlation was also found between free water reabsorption and glomerular filtration rate. Diluting capacity was evaluated by determining minimum urine osmolality and free water clearance. A highly significant correlation between minimum urine osmolality and free water clearance was obtained. There was a good correlation between free water clearance and glomerular filtration rate. When sodium reabsorption is depressed below normal, urine sodium concentration during hydropenia is abnormally low. A normal standard bicarbonate level does not exclude a defect in renal acidifying mechanisms. A defect renal acidifying capacity could be found even in patients with normal filtration rates indicating that renal acidifying capacity might be the first sign of renal damage in children with recurrent urinary tract infections.     

Chronic renal failure in methylmalonic acidaemia

The renal function of 12 patients with non vitamin B₁₂ responsive methylmalonic acidaemia has been investigated. Eight patients had reduced glomerular filtration rates, but the plasma creatinine concentration was only raised in those with values of less than 40ml/min per 1.73m² surface area. The reduction in glomerular filtration was a function of the age and the severity of the disease. Plasma urate concentrations were increased in four patients but this may be secondary to the renal disease rather than its cause.Abbreviations 51 Cr-EDTA 51-chromium ethylenediamine tetraacetic acid - GFR glomerular filtration rate - MMA methylmalonic acidaemia - SA surface area - TRP tubular reabsorption of phosphate - Ua/Uc urinary albumin/creatinine concentration ratio - Ul/Uc urinary lysozyme/creatinine concentration ratio     

Renal tubular dysfunction following treatment with anti-epileptic drugs

To evaluate renal side-effects of anti-epileptic medication in children, we performed a cross-sectional study of various aspects of renal function. We studied 59 patients from our outpatient clinic. They had been on anti-epileptic monotherapy for at least 3 months. None had a history of renal disease. Twenty-three healthy children of the same age group served as controls. After collecting 24-h urine samples, glomerular function was derived from creatinine clearance and from the excretion of albumin. Proximal tubular function was investigated by the urinary excretion of 1-microglobulin and of the tubular enzymes N-acetyl-ß-D-glucosaminidase, alamine-amino-peptidase and fructose-1,6-di-phosphatase. Distal tubular function was examined by the 24-h excretion of Tamm-Horsfall protein. On treatment with carbamazepine (n=27) and phenytoin (n=8), the excretion of 1-microglobulin was significantly increased, as compared with the healthy controls. On valproate (n=20), ethosuximide (n=9) and phenytoin (n=8), therapies significantly increased excretion of N-acetyl-ß-D-glucosaminidase. This must be interpreted as an indication of a functional disturbance of the proximal tubulus. The other parameters, indicating function of the glomerulus, loop of Henle and distal tubules did not differ from normal.Patients on anti-epileptic treatment with therapeutic drug levels may demonstrate minor signs of tubular dysfunction. These are probably insignificant from a clinical standpoint, but they should be considered in drug overdose.     

SERUM PROLACTIN LEVELS IN RENAL INSUFFICIENCY IN CHILDREN

Abstract. Ijaiya, K., Roth, B. and Schwenk, A. (The University Children's Hospital, University of Cologne, Cologne, Federal Republic of Germany). Serum porlactin levels in renal insufficiency in children. Acta Paediatr Scand, 69: 299, 1980.—Basal prolactin concentrations in forty-eight children with acute or chronic renal disease have been compared with those in thirty-four healthy control subjects. Elevated basal prolactin levels and an abnormal prolactin response to intravenous thyrotropin-releasing hormone were found in children with chronic renal failure on maintenance intermittent haemodialysis. No significant change in plasma prolactin concentrations and osmolality was observed before and after haemodialysis, despite a fall in plasma creatinine concentrations. The elevated prolactin levels fell to normal in three patients after successful renal transplantation. It is suggested that the kidney has an important role to play in prolactin metabolism.     

Urinary arginine vasopressin (AVP) measurement in children: Water deprivation test incorporating urinary AVP

The value of a water deprivation test incorporating urinary arginine vasopressin (AVP) measurement was investigated in 13 patients with polydipsia and/or polyuria (complete central diabetes insipidus [CCDI] in four; incomplete central diabetes insipidus [ICDI] in five; secondary nephrogenic diabetes insipidus [NDI] in three; compulsive water drinking [CWD] in one) and a group of 25 control subjects (C). Urine samples were collected after water deprivation during sleep and the urinary osmolalities and AVP concentrations were measured. Analysis of the results of 104 urine samples from the 25 control subjects demonstrated a close correlation between urinary osmolality and AVP (r = 0.89, P < 0.001). After water deprivation during sleep, the respective mean maximal urinary osmolalities and AVP concentrations were: 127.4±34.4 mOsm/kgand 1.1±0.5 pg/mL in the patients with CCDI (14 samples, four children); 410.3±101.8 and 6.1±3.5 in those with ICDI (16 samples, five children); 348.7±71.2 and 100 + 45.1 in those with NDI (nine samples, three children); 541.5±143.5 and 43.6±33.2 in the patient with CWD (two samples, one child) and 898.8±186.3 and 97.4±50.4 in group C (54 samples, 18 children). Furthermore, the urinary AVP level relative to the osmolality in each patient varied depending on the AVP secretion status and renal concentrating ability. Each patient, except the one with CWD, could be discriminated from the normal subjects using this test. It seems that this test is easy to perform and useful for diagnosis and follow-up of patients with partial/complete posterior pituitary function defects and those with renal concentration impairment.     

Soluble receptors to tumour necrosis factor and interleukin-6 in urine during acute pyelonephritis

We compared the urinary concentrations of soluble TNF-I (sTNF-RI), TNF-II receptors, and soluble IL-6 receptor (sIL-6R) standardized to urinary creatinine concentrations, in children with acute pyelonephritis, in children with non-renal fever and in healthy controls. These levels were related to the acute inflammatory response in the kidneys and later renal scarring, as determined by acute and 1-y follow-up with ^99mTC-dimercaptosuccinic acid scintigraphy (DMSA). The concentrations of the soluble receptors were measured using enzyme immunoassay (EIA). The urinary levels of sTNF-RI were significantly higher in children with acute pyelonephritis (median 1320 pg/mmol) than in children with non-renal fever, children 6 weeks after acute pyelonephritis and healthy controls (873, 251 and 477 pg/μmol, respectively). Median sTNF-RII urine levels were also higher in acute pyelonephritis (4123 p/μmol) than in the three control groups (2000, 964 and 1850 pg/μmol, respectively). In contrast, the highest urinary sIL-6R concentrations were found in healthy children (median 420 pg/μmol). compared to those with acute pyelonephritis (235 pg/μmol), children with non-renal fever and children 6 weeks after pyelonephritis (137 and 50 pg/μmol, respectively). No significant difference was found in any of the urinary soluble receptor levels in children with or without DMSA uptake defects at the acute or the 1-y follow-up scintigraphy. In conclusion, although the urinary soluble TNF receptor levels were higher during acute pyelonephritis, this observation was not useful for deciding which children needed follow-up after acute pyelonephritis.     

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目的分析无症状尿检异常患儿的肾脏病理,了解无症状尿检异常患儿的病理改变和临床表现的关系。方法回顾性分析上海交通大学医学院附属新华医院儿内肾脏科2004年1月至2010年12月172例无症状尿检异常患儿临床资料,根据尿检结果分为单纯性血尿组(149例,86.6%)、单纯性蛋白尿组(7例,4.1%)和血尿合并蛋白尿组(16例,9.3%),所有患儿排除感染、结石、肿瘤及继发性肾炎并进行肾活检作光镜、免疫病理和电镜检查。结果 172例患儿的病理分型显示:肾小球轻微病变115例(66.9%)、局灶节段性肾小球硬化22例(12.8%)、IgA肾病13例(7.6%)、局灶球性肾小球硬化11例(6.4%)、薄基膜病4例(2.3%)、其他7例(4.1%)。血尿合并蛋白尿组中肾小球轻微病变占31.3%,IgA肾病占50%。单纯性血尿组中肉眼血尿患儿的肾脏病理中肾小球轻微病变和局灶节段性肾小球硬化分别占56.3%和25.0%。结论幼儿园入园尿检和入学尿检有利于早期发现慢性肾脏疾病。尿检异常中单纯性血尿需要密切随访,血尿合并蛋白尿和肉眼血尿患儿的应尽早进行肾组织穿刺活检。     

Antenatal hydronephrosis and fetal urine sampling

The aim of this study is to evaluate the significance of renal pelvis aspiration (RPA) in the management of antenatal hydronephrosis (AHN). This study enrolled 15 AHN cases (one twin pregnancy) that necessitated RPA for AHN. Chromosomal abnormalities, gene disorders, and additional life-threatening congenital abnormalities were eliminated prior to intrauterine interventions. Urine analysis were performed for the evaluation of renal function. Normal renal function was observed in six neonates/infants (40%) (group 1), whereas impaired renal function and various type of urinary system anomalies were observed in 9 neonates/infants (60%) (group 2) during the short-term and longitudinal follow-up periods. There were statistically significant differences in the oligohydroamniosis rate, mean fetal urine sodium value, mean fetal urine β2-microglobulin, mean gestational week at birth, and mean birthweight values between the groups (P = 0.007, P < 0.001, P = 0.035, P < 0.001, and P = 0.001, respectively). Renal pelvis aspiration and urine analysis were substantial for the management of AHN in necessary cases. β2-microglobulin and sodium are clinically useful markers to detect the presence of severe renal damage due to obstructive uropathy and thus, important adjuvants in the proper selection of fetuses for further antenatal interventions.     

Intra-patient variability in tacrolimus trough concentrations and renal function decline in pediatric renal transplant recipients

Prytula AA, Bouts AH, Mathot RAA, van Gelder T, Croes LK, Hop W, Cransberg K. Intra‐patient variability in tacrolimus trough concentrations and renal function decline in pediatric renal transplant recipients. Abstract: High intra‐patient variability in TCL exposure is a risk factor for allograft loss and late acute rejection. We hypothesized that a higher intra‐patient variability leads to a faster decline in GFR in pediatric renal transplant patients and that adolescents have a higher intra‐patient variability due to poorer adherence. We included 69 children aged 3.5–18 yr who had undergone renal transplantation between April 1996 and May 2009 in two pediatric nephrology centers in the Netherlands. We analyzed TCL trough concentrations over a period of one yr and calculated TCL trough concentrations variability using VC. We investigated the correlation between the TCL trough concentrations variability and the decline in estimated GFR over four yr. The median intra‐patient variability in TCL concentrations was 30.1% (range 8.6–77.6) and the mean GFR slope ?3.8 mL/min/1.73 m²/yr. The VC correlated neither with the GFR slope, nor with the patients’ age. However, children with late acute rejection had higher VC (p = 0.045). We were unable to provide evidence that a high variability in TCL exposure leads to a faster decline in renal function, although children with late acute rejection have a higher variability in TCL exposure. Adolescents do not have a higher intra‐patient variability in TCL trough concentrations than younger children.     

Quantitation of renal antigen excretion in the urine of normal children and of children with various renal diseases. I. Quantitation of renal antigens in random urine samples.

This study reports a serologic method for the measurement of kidney-derived antigens in the urine of healthy children and of children with renal diseases. Two hundred twenty patients were studied. Four groups were recognized: group A, patients with no evidence of renal disease; group B, patients with past history of active urinary tract infection; group C, patients with active urinary tract infection; group D, patients with other renal diseases. Urinary renal antigen concentration was tested by the complement fixation method, in which titers of antigens in the urine were compared with a standard human renal antigen extract. The distribution of renal antigen concentrations in group C differed significantly (P(X2Y less than 0.001) from the other three groups. About 85% of patients in groups A, B, and D had levels below 0.6 mg/ml, whereas in group C only 53% of patients had similar concentrations. After factoring the results by the urinary concentration of creatinine, 85% of patients in group C had antigen levels above 0.6 mg/ml as opposed to 24%, 44%, and 27% in groups A, B, and D, respectively. The results of the study are consistent with the assumption that the rate of discharge of renal antigenic material in the urine is accelerated in certain renal diseases.     

Iodine status in pre‐school children prior to mandatory iodine fortification in Australia

The iodine status of children between the ages of 5 and 15 years has been routinely assessed in many countries, but few studies have examined iodine status in pre‐school children. We conducted a cross‐sectional study of pre‐school children living in Adelaide, South Australia, between 2005 and 2007. Children 1–5 years old were identified using a unique sampling strategy to ensure that the study population was representative. A 3‐day weighed diet record, a blood sample and a urine sample were obtained from each child. The median urinary iodine concentration (UIC) of the children (n = 279) was 129 µg L^?1, indicating iodine sufficiency (normal range: 100–199 µg L^?1), but 35% of the children had a UIC < 100 µg L^?1. The median thyroglobulin concentration of children (n = 217) was 24 µg L^?1 and thyroglobulin concentration declined with increasing age (P = 0.024). The mean daily iodine intake was 76 µg. The intake of iodine was lower than expected and highlights difficulties in accurately assessing iodine intakes. Further studies are needed to monitor dietary changes and iodine status in this age group since the implementation of mandatory fortification of bread with iodised salt in Australia in 2009.     

Acute obstructive uropathy —a rare complication of circumcision

We report a rare complication of of ritual circumcision in an 8-week-old boy. He presented 1 week after the procedure with reduced urine output, a grossly distended bladder and marked bilateral hydroureteronephrosis on ultrasonography. The acute partial urinary obstruction was due to the dressing which was applied after surgical removal of the foreskin and to oedema of the glans. He had abnormal renal function (creatinine 85 mol/l, urea 8.5 mmol/l) and a hyperkalaemic metabolic acidosis with hyponatraemia (Na 127 mmol/l, K 6.9 mmol/l, HCO₃ 16 mmol/l), which were attributed to obstructive uropathy. Because of prolonged secondary bladder dysfunction he required urinary catheterisation for 1 week. There was significant post obstructive diuresis and parenteral fluid therapy was given for 7 days. Whilst urinary retention is a well recognised complication of circumcision, this is the first report of significant obstructive uropathy and renal impairment due to surgical excision of the foreskin.     

Renal function and cardiac angiography

Objective: To study the effect of non-ionic contrast medium on renal function in children with cardiovascular disease.Methods: Analysis of renal function in 98 children with cardiovascular disease before and after the use of lopamidol, lohexol, and loversol was done for angiography. Serum creatinine (s-Cre), urinary N-acetyl-beta-D-glucosaminase (u-NAG), urinary beta 2-microglobulin (u-BMG), and urinary alpha 1-microglobulin (u-AMG) levels were evaluated.Results: Although s-Cre levels remained unchanged, u-NAG/Cre, u-AMG/Cre and u-BMG/Cre significantly increased 12 hours after angiography. Levels of u-NAG/Cre, u-BMG/Cre, and u-AMG/Cre after angiography were significantly higher in neonates and infants (age<12-Months, n=32) than in children (age>1-year, n=61), in patients with more than 5 ml/kg of contrast medium (n=25) than in those with less than 5 ml/kg (n=70) and in cyanotic patients (n=13) than in non-cyanotic (n=80) patients.Conclusion: Transient renal tubular dysfunction occurred in all of these three non-ionic contrast mediums. Although renal tubular function was intact on a long-term basis, one should be careful of contrast medium-induced nephropathy, especially in neonates and infants, in patients receiving more than 5 ml/kg of contrast mediums in total, and in patients with cyanotic heart disease in using non-ionic contrast mediums.     

Stable long‐term renal function after pediatric liver transplantation

Herlenius G, Hansson S, Krantz M, Olausson M, Kullberg‐Lindh C, Friman S. Stable long‐term renal function after pediatric liver transplantation.
Pediatr Transplantation 2010: 14:409–416. © 2010 John Wiley & Sons A/S. Abstract: Long‐term exposure to calcineurin inhibitors increases the risk of CKD in children after LT. The aims of this study were to study renal function by measuring GFRm before and yearly after LT, to describe the prevalence of CKD (stage III: GFR 30–60 mL/min/1.73 m²) and to investigate if age and underlying liver disease had an impact on long‐term renal function. Thirty‐six patients with a median age of 2.9 years (0.1–16 yr) were studied. Median follow‐up was 6.5 (2–14 yr). GFRm decreased significantly during the first six months post‐transplantation with 23% (p < 0.001). Thereafter renal function stabilized. At six months, 17% (n = 5) of the children presented CKD stage III and at five yr the prevalence of CKD III was 18% in 29 children. However, in 13 children with a 10‐year follow‐up it was 0%. None of the children required renal replacement therapy after LT. When analyzing renal function of those children younger than two yr (n = 14) and older than two yr (n = 17) at the time of transplantation, we found that in both cohorts the filtration rate remained remarkably stable during the five‐yr observational period. However, there was a statistically significant (p < 0.05) difference in the percentual decrease in GFRm between the groups during the first six months after LT 13% and 31%, respectively. Baseline GFRm according to diagnosis did not differ between the groups. During the first six months after LT, patients transplanted for hepatic malignancy (n = 6) and those with metabolic liver disease (n = 4) had a percentage loss of GFRm of 32% and 35%, respectively. The corresponding loss of GFRm in patients with other diseases was 10‐19%. Six months post‐transplantation mean GFRm in the group with malignant liver disease was 65 ± 15 mL/min/1.73 m² and in the group with other diseases (n = 24) 82 ± 17 mL/min/1.73 m² (p < 0.05). At one, three and five yr post‐transplantation there was no longer a statistically significant difference between these cohorts. Our findings suggest that there can be a long‐term recovery of renal function after LT in children.     

Medical management of congenital anomalies of the kidney and urinary tract

Renal damage in children has been found to be more congenital in origin than was previously thought. Congenital anomalies of the kidney and urinary tract (CAKUT) involve renal dysplasia, renal hypoplasia, urinary tract obstruction and vesicoureteral reflux. CAKUT are sometimes bilateral and different types often coexist. Depending on their types and severity, children with CAKUT often have varying degrees of a reduced number of nephrons at birth. CAKUTare now the leading cause of renal failure in children. Children with renal dysplasia or obstructive uropathy may have abnormal renal tubules, and tend to lose essential water and sodium in urine. This can lead to poor body growth unless they are supplemented with water and sodium. Children with severe ureteric reflux often develop urinary infection and renal scarring. Renal scarring can further increase the risk of renal failure in children who already have other CAKUTand fewer nephrons than normal. Hypertension and proteinuria may develop in children with renal dysplasia and further aggravate renal function unless they are treated. Recent advances in the understanding and management of CAKUT make it possible for children with CAKUT to grow normally, have fewer complications such as urinary infection, have longer renal survival, and survive even with end-stage renal diseases through renal replacement therapy.     

过敏性紫癜患儿尿中中性粒细胞明胶酶相关脂质运载蛋白、尿胱抑素C水平测定及其意义

目的 检测过敏性紫癜(HSP)患儿尿中中性粒细胞明胶酶相关脂质运载蛋白(NGAL)、尿胱抑素C(Cys C)、尿β<,2>-微球蛋白(β<,2>-MG)水平及24 h尿蛋白定量,探讨尿NGAL、Cys C在检测HSP患儿肾小管间质损伤中的临床意义.方法 选择临床诊断为HSP的患儿60例.根据24 h尿蛋白定量将患儿分为尿检末见异常组(A组,20例)、尿检轻度异常组(B组,20例)、尿检重度异常组(C组,20例)、治疗后病情好转组(D组,15例,均为C组治疗后患儿).选取在本院儿童保健门诊体榆健康儿章20例为健康对照组.其中15例患儿(B组5例,C组10例)行肾脏病理检查,并对肾小管间质进行病理评分.30例患儿(B组10例,C组20例)行尿蛋白电泳检查.设立尿NGAL、Cys C、β<,2>-MG的正常参考值上限,高于此值者视为异常,并计算异常率.结果 1.A、B、C组尿NGAL及Cys C水平升高,且呈递增趋势;D组尿NGAL水平与健康对照组比较无明显差异,尿Cys C水平较B组降低,但高于健康对照组.2.B组尿NGAL的异常率高于尿β<,2>-MG,尿Cys C的异常率与尿β<,2>-MG比较无明显差异;D组尿β<,2>-MG的异常率高于尿NGAL.3.尿NGAL、Cys C、β<,2>-MG水平与肾小管间质病理评分、尿蛋白电泳结果均呈正相关(r=0.638、0.471;0.661、0.321;0.405、0.342,P<,a><0.05).C组患儿小管间质病例评分、尿蛋白电泳(小管性)结果均高于 B组(P<,a><0.05).结论 尿NGAL、Cys C可作为监测HSP患儿早期肾小管间质损伤的指标,具有较高的灵敏度和特异性,优于传统指标尿β<,2>-MG.     

Interleukin-1α and interleukin-1 receptor antagonist in the urine of children with acute pyelonephritis and relation to renal scarring

Urinary concentrations of interleukin-lα (IL-lα) and interleukin-l receptor antagonist (IL-Ira) standardized to urinary creatinine concentrations were studied. The median standardized IL-1α creatinine quotient in children with first-time acute pyelonephritis was 3.6 pg/μmol, but was non-detectable in children with recurrent pyelonephritis, children with non-renal febrile conditions and children convalescent after acute pyelonephritis ( p < 0.05–0.01). IL-lra levels were also significantly higher in children with acute first-time pyelonephritis (median of 239 pglpmol) compared to these three groups of children ( p < 0.01–0.001). The highest urinary 1L-lra levels, however, were found in the healthy controls (median value 1.019; p < 0.001). Both cytokines were higher among children younger than one year compared to older children. The acute IL-lα creatinine quotients were lowest in children with uptake defects on ^99mTC-dimercaptosuccinic acid (DMSA) scintigraphy both during the acute infection (reflecting the acute inflammation) ( p < 0.001) and 1 year after the acute infection (reflecting permanent kidney scarring) ( p < 0.01). In conclusion, persisting high urinary levels of 1L-lα were associated with less renal inflammation and scarring.     

COMBINED SUPRAPUBIC ASPIRATION AND CLEAN-VOIDED URINE EXAMINATION IN INFANTS AND CHILDREN

In 120 infants and children a comparison was made between suprapubic aspiration urine and concomitantly obtained clean-voided urine. The following conclusions could be made from this study: (1) By performing suprapubic aspiration of urine, true bacteriuria could be diagnosed. 31 false positive and 8 false negative clean-voided urine samples were disclosed. (2) Furthermore, by the combined procedure of urinary collection, it was possible to elucidate the diagnostic value of accurately performed leucocyte counting in uncentrifuged urine. In infants leucocyte counts above 250/ mm³ in clean-voided urine and above 10/mm³ in suprapubic aspiration urine always accompanied a urinary infection, whereas the degree of leucocyturia in children was inconclusive.     

Plasma and urinary soluble adhesion molecule expression is increased during first documented acute pyelonephritis

Background: The degree of inflammatory reaction and leucocyte trafficking during acute pyelonephritis has been related to the risk of developing renal parenchymal scarring. Adhesion molecules play a central role in leucocyte recruitment during inflammation. Aims: (1) To determine whether circulating and urinary concentrations of E-selectin and intercellular adhesion molecule 1 (ICAM-1) were abnormal during first documented acute pyelonephritis; (2) to investigate whether circulating or urinary concentrations were predictive for the development of abnormalities on DMSA imaging. Methods: Plasma and urine samples were collected from 40 children with a first episode of acute pyelonephritis within one week of infection (acute sample) and at six weeks (late sample). Control samples were collected from 21 healthy age matched controls and 18 age matched controls with febrile illness not secondary to urinary tract infection. Results: Plasma and urinary sE-selectin were higher in acute samples (median 176.3 ng/ml and 0.12 ng/mmol respectively) compared with late (97.8 ng/ml and 0.029 ng/mmol) and both control (65.6 ng/ml and 0 ng/mmol) and febrile control (urine 0 ng/mmol) samples. Plasma sICAM-1 was higher in acute samples (428 ng/ml) than controls (365.2 ng/ml), and acute sICAM-1 urine concentrations were higher than febrile control concentrations (3.2 v 0.7 ng/mmol). No correlations were detected between sE-selectin or sICAM-1 and acute or late DMSA scan changes. Conclusion: Plasma and urinary sE-selectin and sICAM-1 are significantly increased during acute pyelonephritis, though no correlation exists between the presence of high plasma or urine concentrations and DMSA scan changes, both during acute infection and six weeks post-infection.     

Renal functional measurements in young rats with chronic inhibition of nitric oxide synthase

The purpose of the present study was to examine renal functional changes caused by chronic blockade of nitric oxide (NO) synthesis in young rats. Two types of NO synthase inhibitor were used: N^G-nitro-L-arginine methyl ester (L-NAME) as a non-selective inhibitor and aminoguanidine (AG) as a selective inhibitor of the inducible isoform. Oral administration of L-NAME (20–80 mg/dL of drinking water), not AG (400 mg/dL), for 4 weeks induced systemic hypertension in the treated rats. Both inhibitors caused a significant reduction in urinary excretion of NO₂^?/NO₃^?. Rats treated with L-NAME developed proteinuria and tubular enzymuria (high excretion of N-acetyl-β-D-glucosaminidase) in a dose-dependent fashion, with normal serum levels of creatinine, albumin and cholesterol. Chronic AG administration did not alter the urinary levels of protein and N-acetyl-β-D-glucosaminidase or serum laboratory values. Overall, these observations highlight the importance of the continuous generation of NO by the constitutive isoform in the control of vascular tone and the maintenance of renal glomerular and tubular function. Oral administration of L-NAME may serve as a model of chronic NO-deficient hypertension with renal injury in young rats.