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Biomedical subjects

U Alon

Publications and source records attributed to U Alon.

At least 73 records · Page 4Linked to original sources
PubMed1990

The value of ultrasound in Schoenlein-Henoch purpura.

We report the results of ultrasound studies on 11 children with Schoenlein-Henoch purpura. In 8 children the ultrasound examination was normal. In two of three patients with macroscopic haematuria, haemorrhagic cystitis, a previously undescribed finding in Schoenlein-Henoch purpura, was found. In one case the gall bladder wall and the wall of several adjacent loops of bowel were markedly thickened. Follow up examinations after clinical recovery demonstrated complete resolution of these abnormalities. Our observations demonstrate that diagnostic ultrasound may have an important role before more expensive and invasive procedures are employed in patients with Schoenlein-Henoch purpura.

Child↗
PubMed1990

Acute increase in serum tonicity following exchange transfusion. Increased risk for the very low birthweight infant during the first 48 hours of life.

We analysed the data of difference in serum sodium (DIFNA) and glucose (DIFGLU) concentrations and difference in serum tonicity (DIFTON) following exchange transfusion (ET) with CPD blood during 122 consecutive procedures performed in 82 newborn infants. Mean (+/- SE) gestational age (GA) was 30.8 +/- 0.45 weeks, mean birthweight was 1,568.6 +/- 81.4 g. and mean age at time of ET (AGEH) was 60.6 +/- 4.3 h. Following the ET, mean serum sodium concentration increased in 110 cases, by 5.4 +/- 0.7 mmol/l, and the mean DIFTON rose by 14.6 +/- 1.46 mOsm/kg H2O. Mean DIFGLU rose in 11 cases by 3.8 +/- 0.3 mmol/l. Significant correlations were found between DIFNA and AGEH (p less than 0.02), and between DIFTON and AGEH (p less than 0.02). ET performed less than 48 h after birth produced higher DIFTON values than later transfusions (21.2 vs. 8.2 mOsm/kg H2O, p less than 0.001) particularly in the VLBW infants (31.1 in less than 28 weeks vs. 15.1 mOsm/kg H2O in greater than 28 weeks). VLBW neonates appear to be at greatest risk of developing extreme increments in serum tonicity following ET performed within the first 48 h of life.

Blood Glucose↗
PubMed1989

Protein intake and renal function in children.

To evaluate the effects of protein intake on renal tubular functions, seven metabolic studies were performed on five adolescents with mild, chronic renal insufficiency. After equilibration, patients were randomly assigned to two periods of four days each on either a high-protein diet (HPD) or a low-protein diet (LPD), with energy intakes remaining the same during both periods. High protein intake resulted in significantly higher mean (+/- SD) daily creatinine excretion and clearance rates. The HPD was associated with significantly increased excretion rates of potassium, phosphate, sulfate, and calcium. Net acid excretion with the HPD was nearly threefold higher than that observed with the LPD. These differences were unassociated with urinary pH, which remained similar with both diets. We conclude that different protein intakes affect urinary excretion of creatinine, potassium, phosphate, sulfate, calcium, and net acid.

Adolescent↗
PubMed1989

Familial distal renal tubular acidosis with neurosensory deafness: early nephrocalcinosis.

Nephrocalcinosis was observed in 3 children of one family with distal renal tubular acidosis (dRTA). At presentation, all 3 patients had failure to thrive, rickets, hyperchloremic metabolic acidosis, hypokalemia, hypophosphatemia and hypercalciuria. At a later age, sensorineural hearing impairment was detected. Nephrocalcinosis was diagnosed in the index case at the age of 5 years, when a plain abdominal roentgenogram was first made; in the younger brother and sister, nephrocalcinosis was detected earlier at the age of 4 months and 5 weeks, respectively. All 3 patients required large doses of alkali (7.5-9.5 mEq/kg body weight/day) during infancy and early childhood to correct the acidosis and to prevent progression of the nephrocalcinosis. Contrary to the current notion that in children with dRTA, nephrocalcinosis is observed only after the age of 3 years, it appears that in some instances nephrocalcinosis may develop in early infancy. The occurrence of nephrocalcinosis at a very young age may be a manifestation of a severe genetically transmitted variant of dRTA and emphasizes the need for early diagnosis and optimal treatment of these patients from the first days of life.

Acidosis, Renal Tubular↗
PubMed1989

Intravenous pyelography in children with urinary tract infection and vesicoureteral reflux.

In a previous study of the radiologic evaluation of children with urinary tract infection it was recommended that IVP be performed in all patients with either abnormal ultrasonographic or voiding cystourethrographic findings. However, the benefit from IVP was believed to be questionable in children with normal ultrasonography findings and vesicoureteral reflux of only a low grade (I or II of V). To gain a better understanding of the need for IVP in the radiologic evaluation of such children, the database was expanded and the findings concerning ultrasonography and IVP were analyzed in 52 children with urinary tract infection and vesicoureteral reflux seen during the last 3 years. Of a total of 72 instances of reflux, 44 (61.1%) were of low grade (I or II), 14 of medium grade (III), and 14 of high grade (IV or V). Of the 44 urinary systems with low-grade reflux, results were as follows: renal ultrasonography appeared normal in 38 and in 34 of these, the IVP also appeared normal; in the other four, only minor and negligible changes were seen with IVP. Surgical intervention was not necessary in any of these 38 urinary systems. In six systems with low-grade vesicoureteral reflux but with abnormal ultrasonography findings, IVP results were also abnormal, and surgery was necessary in two instances. Of the 14 urinary systems with medium-grade reflux, ultrasonography appeared normal in ten but in six of these the IVP appeared abnormal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Immunoregulation with levamisole in children with frequently relapsing steroid responsive nephrotic syndrome.

The immunological and clinical effects of levamisole were studied in 10 children with frequently relapsing steroid responsive nephrotic syndrome (SRNS). The efficacy of the drug was tested during remission of the disease with all patients on alternate day steroid therapy. The lymphocyte proliferative response to phytohemagglutinin (PHA), concanavalin-A (Con-A) and pokeweed mitogen (PWM) were normal. The Con-A induced suppressor T-lymphocyte activity of 7 patients was low before treatment with levamisole 8 +/- 3.7% and increased to normal values during therapy 34 +/- 6%; p less than 0.001 (control 32 +/- 5%). In these 7 children prednisolone dosage could be decreased significantly or discontinued altogether (44.1 +/- 5.3%). Patients without immunoregulatory abnormalities did not respond to levamisole. In 3 out of 4 children tested the percentage of OKT8+ cells rose during levamisole therapy from 19.7 +/- 2.1 to 37 +/- 2.3 (p less than 0.001), thus correcting the elevated pre-treatment OKT4+/OKT8+ ratio from 3.1 +/- 0.2 to 1.5 +/- 0.2; p less than 0.001 (control 1.47 +/- 0.2). These data support the hypothesis that abnormal immunoregulation may play a role in the pathogenesis of SRNS. Treatment with levamisole can be useful in some patients with the frequently relapsing form of the disease.

Adolescent↗
PubMed1988

Effective peritoneal dialysis in an infant with extensive resection of the small intestine.

Acute renal failure and pulmonary edema developed in a 1-month-old baby with necrotizing enterocolitis and hypovolemic shock. Following resection of 93% of her small intestine and mesentery, peritoneal dialysis was started; it was terminated 96 h later with complete recovery of renal and pulmonary functions. Two weeks later, while on total parenteral nutrition, the infant developed fulminant septicemia and died. Postmortem examination showed normal kidneys. Surface measurement of the abdominal wall and viscera revealed that the actual peritoneal surface area of the patient was 671 cm2, only 44% of her calculated normal peritoneal surface area. We conclude that effective peritoneal dialysis is feasible in infants with acute renal failure even after marked reduction of the peritoneal surface area.

Edema↗
PubMed1988

Percutaneous kidney needle biopsy in children is less traumatic than in adults.

Hemorrhagic complications following percutaneous kidney needle biopsy were prospectively assessed in 20 children and adolescents (age 2-17 years) undergoing a total of 22 biopsies. Macroscopic hematuria was observed in 1 case and hematocrit reduction of more than 3% in 2. Gray-scale ultrasonography performed in all patients 48 h after the biopsy detected peri- and intrarenal hematomas in 2 cases. Based on these data and those from another study on children, comparison to three similar studies in adults showed a 9.3% mean incidence of macroscopic hematuria in children versus 36.2% in adults (p less than 0.01), a 9.1 versus 31.3% mean incidence of hematocrit reduction of more than 3% (p less than 0.05), and a mean incidence of only 10.9% in children versus 65.6% in adults of radiologically detected peri- and intrarenal hematomas (p less than 0.001). We conclude that percutaneous kidney needle biopsy in children is less traumatic than in adults. Hence when relating to hemorrhagic complications of the procedure, the two populations have to be addressed separately.

Adolescent↗
PubMed1988

Role of renal prostaglandins in bile-induced diuresis in the dog.

To clarify the possible role of renal prostaglandins (PGs) in the phenomenon of bile-induced diuresis in the dog, we studied the effect of in situ unilateral infusion of bile on kidney function and PGs excretion, before and after PG-synthetase inhibitor administration in anesthetized dogs. The contralateral intact kidney served as control. In the first group of 6 dogs, infusion of bile diluted 1:20 resulted in a significant increase in urinary flow (117%; p less than 0.05), sodium (61%; p less than 0.01), potassium (26%; p less than 0.05), PGE2 (240%; p less than 0.05) and PGF2 alpha (137%; p less than 0.05) excretion rates. Further significant increases in urinary flow, sodium and PGE2 excretion rates were noted with infusion of bile diluted 1:10. All parameters returned to basal levels upon cessation of bile infusion. Significant linear correlation coefficients (p less than 0.005) were found between PGE2 excretion rates and urinary flow (r = 0.72), sodium (r = 0.91) and potassium (r = 0.88) excretion rates. In a second group of 6 dogs, intravenous administration of PG-synthetase inhibitor abolished the increase in renal PGs excretion and the increments in the rates of urinary flow and solute excretion in response to bile infusion. These findings support the notion that the acute diuretic and natriuretic effect of bile, and presumably that of cholemia is mediated, in part, through stimulation of renal PGs synthesis.

Animals↗
PubMed1987

Post-obstructive urinary concentrating defect. A case study in the role of prostaglandins.

A child with post-obstructive urinary concentrating defect was studied for the possible pathophysiological role of prostaglandins and an eventual therapeutic approach. Increased urinary excretion of prostaglandins was corrected by indomethacin, with resultant increased nephrogenous cyclic AMP and partial improvement in the concentrating defect. The addition of a thiazide restored urinary concentration. These results add clinical support to the conception of the important role of prostaglandins in the mechanism of post-obstructive hyposthenuria. This therapeutic regimen is advocated for prolonged post-obstructive concentrating defect.

Child, Preschool↗
PubMed1987

Five-year survey of changing patterns of susceptibility of bacterial uropathogens to trimethoprim-sulfamethoxazole and other antimicrobial agents.

We analyzed the antibiotic susceptibility of 5,348 urinary isolates of Escherichia coli, "Klebsiella aerogenes," and Proteus mirabilis grown in three laboratories from 1980 to 1985. A continuous rise in resistance to trimethoprim-sulfamethoxazole was observed; 63% of the strains from inpatients in 1984 and 51% of those from outpatients in 1985 were resistant to this drug. Isolates from outpatients in 1985 were mostly susceptible to nitrofurantoin (mean susceptibility, 92%) and to oral cephalosporins (mean susceptibility, 84%). As for isolates from inpatients, none of the antimicrobial agents now used was satisfactory for initial chemotherapy, indicating a need for new antibacterial strategies.

Ampicillin↗