Hemolytic-uremic syndrome.

The hemolytic-uremic syndrome (HUS) has been recognized for more than 45 years and consists of the combination of hemolytic anemia, thrombocytopenia, and acute renal failure. HUS occurs predominantly in children younger than 4 years of age. It is the most frequent cause of acute renal failure in children. The most common form of the syndrome (D+ HUS) occurs in healthy young children (>6 mo to <5 y of age) and is preceded by watery diarrhea that can evolve to hemorrhagic colitis. The diarrhea precedes the hemolysis and thrombocytopenia by 5 to 7 days; oliguria/anuria follows several days later. Although the pathogenesis is unknown, available evidence strongly suggests that endothelial cell damage is necessary. The outcome for most patients who have D+ HUS is favorable: 65% to 85% recover completely, 5% to 10% die (usually during the acute illness), recurrence is uncommon, and only a few patients slowly progress to end-stage renal disease (ESRD).

Apparent progression of acute glomerulonephritis to dense deposit disease.

One week after the diagnosis of meningococcal meningitis, an 8-year-old boy presented with acute renal failure and hypocomplementemia. A renal biopsy showed "postinfectious glomerulonephritis" and acute tubular necrosis. Hematuria, proteinuria, and low complement levels persisted, and 2 years later a follow-up renal biopsy revealed dense deposit disease. The apparent progression of postinfectious glomerulonephritis to dense deposit disease as observed in this patient has not been previously described.

[Standards, options and recommendations for good practice in hemoculture in cancerology]. / Standards, Options et Recommandations pour une bonne pratique des hémocultures en cancérologie.

Excepting emergency and aplasia: two to three blood samples should be draw for culture an hour apart within a 24 period (standard). For emergency or aplasia: two to three blood samples should be drawn for culture before initiating early antibiotic therapy. The delay between samples drawn from different sites should be less than one hour (standard). For patients on antibiotics: four to six blood samples should be drawn for culture within 48 hours, outside ongoing antibiotic administration. If the patient is given corticosteroids, it is recommended to draw two or three blood samples in case of deterioration (agreement of the experts). Rigorous aseptic techniques must be used (standard). Culture media are chosen according to the institution's microbial ecology (standard). The volume of blood drawn should be adapted to the system used (standard). Culture positivity is determined at 24 to 48 hours.

Increased tacrolimus levels in a pediatric renal transplant patient attributed to chronic diarrhea.

Tacrolimus is an immunosuppressant used to prevent rejection of transplanted organs. It is metabolized in both the gut and the liver by the cytochrome P450 (CYP) 3A4 enzyme system and is a substrate for the P-glycoprotein (P-gp) drug efflux pump. As CYP3A4 enzymes and P-gp are present at differing concentrations throughout the gastrointestinal tract, the bioavailability of tacrolimus may be influenced by changes in gastrointestinal transit time in addition to changes in hepatic metabolism. We report the case of a pediatric renal transplant patient who experienced a three-fold increase in serum tacrolimus concentrations during an episode of gastroenteritis with chronic diarrhea.

Oxybutynin lowers elevated renal pelvic pressures in a rat congenital unilateral hydronephrosis.

We investigated whether oxybutynin could lower elevated renal pelvic pressures measured in a rat with an inbred unilateral congenital hydronephrosis. Simultaneous renal pelvic and bladder pressures were measured in 8 hydronephrotic rats and compared to those of 10 hydronephrotic rats treated with intravenous injection of 1.6 mg./kg. oxybutynin. Pressures were recorded at different urinary flow rates and during bladder filling and emptying. Hydronephrotic rats not given oxybutynin showed significantly higher renal pelvic pressures (e.g. p-bladder at 50% capacity = 8.9 +/- 3.1 cm. H2O, corresponding p-pelvis = 20.8 +/- 2.1 at very high urinary flow rates) than rats treated with oxybutynin. The latter had renal pelvic pressures similar to rats with normal non-hydronephrotic kidneys (e.g. p-bladder at 50% capacity = 10.1 +/- 3.5 cm. H2O, corresponding p-pelvis = 6.3 +/- 1.1 at very high urinary flow rates). Renal pelvic pressures were, moreover, lower than corresponding bladder pressures in contrast to the untreated hydronephrotic pelvic pressure that exceeded bladder pressure. This effect of oxybutynin in lowering elevated renal pelvic pressures in the obstructed kidney has not been described before and suggests a possible role for oxybutynin in this condition.

Office evaluation of the child with hematuria.

Most children with an identifiable cause of hematuria will be properly diagnosed if an appropriate evaluation is completed. However, some children with persistent hematuria will not have an identifiable cause. This article provides clinical advice on properly diagnosing the child.

The quest for living-related kidney donors for children with end-stage renal disease.

In a pediatric renal transplant program that actively seeks living-related kidney donors, we achieved a living donor rate of 55% in 119 children. This approximates the national average but is less than an idealized goal. For black children, the living-donor transplant rate was 41%, a disconcertingly low rate. In an attempt to define factors that negatively affected living-related donor availability, we analyzed our evaluation process by distinct phases (interview, histocompatibility testing and medical evaluation). We classified our families on the basis of locale (urban, suburban and rural), family unit (two or less parents, adult sibs or other relatives presenting at interview) and economic status (designating only economic-disadvantaged and other). While histoincompatibility is predictably a negative factor, the negative impacts of medical illness in the donor pool, economic disadvantage and single parent family are striking and cumulative. Our data validate the relative success of an aggressive recruitment policy in a patient population that includes many economically disadvantaged families. For pediatric renal transplant programs with low living-related donor rates, our data should encourage review and possible modification of the donor recruitment process.

Nutritional management of the child with mild to moderate chronic renal failure.

1. The best way to prevent early growth failure in children with renal disease is by the use of specified nutrition and appropriate buffer, activated vitamin D, and calcium-containing phosphate binders as needed. With prenatal diagnosis of anatomically abnormal kidneys available, this type of early intervention may be much more feasible in the 1990s. 2. Supplemental sodium and water in children with polyuria and intravascular volume depletion may prevent growth failure. Cow milk is detrimental in this group of individuals because of high solute and protein load, often causing intravascular volume depletion, hyperphosphatemia, and acidosis. 3. Children with acquired glomerular disease may need sodium restriction and, if treated with steroids, a diet low in saturated fat. 4. Children with nephrotic syndrome and severe edema should be evaluated for malabsorption and subsequent malnutrition. Protein intake should be supplemented only at the RDA and to replace ongoing losses. Long-term sodium restriction is appropriate. Hyperlipidemia should be monitored: if nephrosis is chronic, a low saturated fat diet should be instituted. Angiotensin-converting enzyme inhibitors can decrease urinary protein loss and may ameliorate hyperlipidemia. Children resistant to therapy can have very high morbidity. 5. Children with <50 % of normal creatinine clearance should have PTH measured and activated vitamin D therapy should be started if PTH is elevated more than two to three times normal. Thereafter careful monitoring of calcium, phosphorus, and PTH is crucial to prevent renal osteodystrophy, low turnover bone disease, and hypercalcemia with hypercalciuria and nephrocalcinosis. 6. Children with tubular defects with severe polyuria also may benefit from low-solute, high-volume feedings. 7. All physicians caring for children with renal disease should have pediatric nephrology consultation available. Prevention of growth failure is much more cost effective than pharmacologic therapy. Before initiating growth hormone treatment for growth retardation, assiduous treatment of co-existing renal osteodystrophy and provision of optimal nutritional intake should be accomplished.

[Bacteriology of the nose and sinuses]. / Bactériologie rhino-sinusienne.

The authors, on the basis of 140 cases, analyze the bacterial flora of essentially chronic rhino-sinusitis observed in hospital consultations at the Pellegrin Hospital, the referral centre of the Aquitaine region. Samples taken in the operating theatre from 100 cases, by aspiration and mucosal biopsy, were studied in aerobic and anaerobic media. The results marked by the scarcity of sterile samples and of anaerobic germs, evidence the predominance of an aerobic flora, with in particular Haemophilus influenzae, Staphylococcus aureus and beta-hemolytic Streptococci. No significant difference was recorded between the bacteriology of acute sinusitis as against chronic sinusitis. The flora of sinusitis appear to depend more on the age factor than on the pathogenic type. Branhamella catharralis is present only in patients under 30. The enterobacteria appear in the adult 30-50 year-old age group and, as from the age of 50, are combined by Pseudomonas aeruginosa, which account for 18% of the strains. These two types of germs then appear to be predominant over the Staphylococci and the Haemophilus.

Four years of natural history of HIV-1 infection in african women: a prospective cohort study in Kigali (Rwanda), 1988-1993.

Clinical features and mortality due to human immunodeficiency virus type-1 (HIV-1) infection in women are described as part of a prospective 4-year cohort study on perinatal transmission of HIV in Kigali, Rwanda. Two hundred fifteen HIV-seropositive (HIV+) and 216 HIV-seronegative (HIV-) pregnant women were enrolled at delivery between November 1988 and June 1989. Clinical information collected during systematic quarterly examinations was compared. HIV antibody tests were performed at delivery and CD4/CD8 lymphocyte counts at 15 days' postpartum. HIV--women who seroconverted during the follow-up period were excluded from the analysis of the comparison group starting at the date of seroconversion. At enrollment, all HIV+ women were asymptomatic for acquired immune deficiency syndrome (AIDS). Incidence of tuberculosis was 2.9 per 100 women-years (WY) after 4 years of follow-up in HIV+ women versus 0.2 per 100 WY among HIV- women (relative risk, 18.2; 95% confidence interval 2.4-137.0). Among HIV+ women, the incidence of AIDS (World Health Organization clinical AIDS definition) was 3.5 per 100 WY. The mortality rate was 4.4 per 100 WY among HIV+ women versus 0.5 per 100 WY among HIV- women. Clinical AIDS was present in only half of the fatalities. Tuberculosis was a major cause of morbidity and mortality in these HIV+ African women. An early diagnosis and an appropriate treatment or prevention of tuberculosis should improve the quality of life of HIV-infected patients in Africa.

Congenital unilateral hydronephrosis in a rat model: continuous renal pelvic and bladder pressures.

We investigated a rat model with inbred unilateral congenital hydronephrosis. Simultaneous bladder and renal pelvic pressures were measured during different urinary flows, and during bladder filling and voiding in these congenitally hydronephrotic rats (approximately 45 days old) and normal nonhydronephrotic rats from the same colony. Differential pressures between pelvis and proximal ureter were determined. Upon termination of the experiment the urinary tract was removed and processed for histological examination. Hydronephrotic rats had significantly higher renal pelvic pressures throughout bladder filling at all urinary flow rates than normal rats. These elevated renal pelvic pressures exceeded bladder pressures at high flows (for example bladder pressure at 50% capacity was 8.9 +/- 3.1 cm. water and corresponding pelvic pressure was 20.8 +/- 2.1 [hydronephrosis] versus pelvic pressure 7.4 +/- 1.1 [control]). While pressures in the proximal ureter were higher than in the pelvis in normal rats the hydronephrotic rats showed significantly higher pressures in the pelvis, suggesting that the site of obstruction is the ureteropelvic junction. Histological evaluation of the excised kidneys revealed only minimal tubular changes. This study represents a unique animal model with unilateral hydronephrosis from a partially obstructing ureteropelvic junction. Moreover, the data indicate that partial urinary obstruction and the associated renal pelvic pressures should be defined with reference to bladder fullness and urinary flow rates.

Ultrafast contrast enhanced magnetic resonance imaging of congenital hydronephrosis in a rat model.

Since new ultrafast magnetic resonance imaging (MRI) might offer unique advantages for evaluating renal blood flow, anatomy and urinary excretion, we used this technique to characterize a rat model with congenital partial ureteropelvic junction obstruction. MRI of 9 rats from an inbred colony with unilateral congenital (nonsurgical) hydronephrosis was compared with the contralateral nonhydronephrotic kidney serving as control. Our new imaging technique consisted of a 1-minute ultrafast gradient recalled imaging sequence during the first minute (64 images per imaging time 960 milliseconds) after contrast bolus injection with gadolinium-diethylenetriaminepentaacetic acid for assessment of renal blood flow followed by a 30-minute period with image acquisition every 30 seconds to study contrast distribution and excretion. Signal intensities were analyzed continuously over selected, different regions of interest. Anatomic analysis of MRI noncontrast studies showed precise delineation of the hydronephrotic pelvis and corticomedullary junction. After contrast gadolinium-diethylenetriaminepentaacetic acid injection signal intensity from the region of interest from hydronephrotic kidneys differed from nonhydronephrotic kidneys by showing less cortical decrease, suggesting decreased blood flow, less medullary decrease and delayed contrast excretion. Clear contrast distribution among the cortex, medulla and collecting system allowed selective estimation of different regions of interest and excellent anatomic evaluation. Renal anatomy and renal pelvic pressures were confirmed after scans were completed. Ultrafast contrast enhanced MRI allows simultaneous assessment of renal morphology, blood flow and function. In hydronephrotic partially obstructed kidneys distinct flow and excretion patterns measured with contrast enhanced MRI allow differentiation between the obstructed and nonobstructed kidney on physiological rather than purely anatomic means. This imaging technique may provide a useful method of evaluating congenital hydronephrosis obviating the need for multiple different diagnostic procedures.

A prospective, double-blind study of growth failure in children with chronic renal insufficiency and the effectiveness of treatment with calcitriol versus dihydrotachysterol. The Growth Failure in Children with Renal Diseases Investigators.

Because controlled trials in adults have shown accelerated deterioration of renal function in a small number of patients receiving calcitriol for renal osteodystrophy, we initiated a prospective, randomized, double-blind study of the use of calcitriol versus dihydrotachysterol in children with chronic renal insufficiency. We studied children aged 1 1/2 through 10 years, with a calculated glomerular filtration rate between 20 and 75 ml/min per 1.73 m2, and with elevated serum parathyroid hormone concentrations. Ninety-four patients completed a mean of 8.0 months of control observations and were randomly assigned to a treatment period; 82 completed the treatment period of at least 6 months while receiving a calcitriol dosage (mean +/- SD) of 17.1 +/- 5.9 ng/kg per day or a dihydrotachysterol dosage of 13.8 +/- 3.3 micrograms/kg per day. With treatment the height z scores for both calcitriol- and dihydrotachysterol-treated groups showed no differences between the two groups. In relation to cumulative dose, there was a significant decrease in glomerular filtration rate for both calcitriol and dihydrotachysterol; for calcitriol the rate of decline was significantly steeper (p = 0.0026). The treatment groups did not differ significantly with respect to the incidence of hypercalcemia (serum calcium concentration > 2.7 mmol/L (> 11 mg/dl)). We conclude that careful follow-up of renal function is mandatory during the use of either calcitriol or dihydrotachysterol because both agents were associated with significant declines in renal function. There was no significant difference between calcitriol and dihydrotachysterol in promoting linear growth or causing hypercalcemia in children with chronic renal insufficiency. Dihydrotachysterol, the less costly agent, can be used with equal efficacy.

Angiotensin or thromboxane receptor antagonism in rats with congenital hydronephrosis.

A technique for the measurement of GFR without collection of urine in rats was experimentally validated and applied to experiments designed to: (1) evaluate the degree of reduction of GFR in rats with congenital, unilateral hydronephrosis; and (2) to determine if the reduction in renal function is mediated by angiotensin II and/or thromboxane A2 mechanisms. Simultaneous measurements of GFR by a constant-infusion technique and the traditional inulin clearance technique in rats with either one or two normal kidneys were highly correlated (r = 0.934; P < 0.001; N = 17). GFR was approximately 24% lower (P < 0.001) in rats with congenital unilateral hydronephrosis than in rats with a normal kidney. The GFR in rats with hydronephrosis infused with a receptor blocker for either angiotensin II or thromboxane A2 was greater than the GFR in hydronephrotic kidneys without blockade and was not significantly different (P > 0.05) from that in rats with normal kidneys. These results indicate that a constant inulin infusion technique without urine collections can be used to accurately measure GFR in congenitally hydronephrotic kidneys, rendering values free from possible residual pelvic volume artifact. In addition, these results also indicate that a significant 24% reduction in GFR occurs in congenital unilateral hydronephrosis and is mediated by angiotensin II and thromboxane A2 mechanisms.

Reversible myopathy due to labetalol.

A severe, generalized myopathy developed in 2 children treated with labetalol. An 11-year-old girl and a 14-year-old boy demonstrated proximal weakness and markedly elevated creatine kinase levels during labetalol therapy. Clinical improvement began immediately when labetalol administration was halted; muscle strength was normal within 2 months. Muscle biopsies were consistent with rhabdomyolysis.

Estimation of parenteral fluid requirements.

This article reviews the normal physiologic losses of water and electrolytes from the body, the source of the loss, and the increased body loss of water associated with fever. The three different methods for estimating replacement of water and electrolyte losses are described in this review.