Reduction of hypertension in hypovolaemia.
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Biomedical subjects
Publications and source records attributed to T M Barratt.
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We describe six infants, from consanguineous marriages, with a new syndrome comprising the Fanconi syndrome, ichthyosis, musculoskeletal abnormalities, jaundice and diarrhoea. In addition two of the infants were found to have abnormal platelet morphology--the grey platelet syndrome. No evidence of a recognised metabolic disorder was found in any of the six infants, nor did they appear to be typical of any previously described syndromes. Their progress was poor: they required high fluid and bicarbonate intakes and all died by the age of 6 months of dehydration, acidosis and sepsis.
The clinicopathologic and radiologic features of 12 children with complete and incomplete forms of Drash syndrome are reported. Their common denominator was a nephropathy. Four had the full triad, consisting of nephropathy, Wilms tumor, and genital abnormalities; five had nephropathy and genital abnormalities, and three had nephropathy and Wilms tumor. Of the 11 children who had proteinuria, eight had the nephrotic syndrome. Of the 10 whose condition progressed to end-stage renal failure, seven were less than 3 years of age. The histologic features of Wilms tumor were favorable in all seven children, and the tumor was bilateral in three. Of the nine patients who had genital abnormalities, eight had 46,XY karyotype and either ambiguous genitalia (six patients) or normal female phenotype (two). One other patient had a normal 46,XX female karyotype and phenotype but had both müllerian and wolffian structures and a streak ovary. Nine patients had a distinct pelvicaliceal abnormality not previously reported as a feature of this syndrome. Other congenital abnormalities were aniridia, mental retardation, deafness, nystagmus, and cleft palate. This syndrome must be considered in any infant with unexplained nephropathy, particularly in young phenotypic female infants and in those children with ambiguous genitalia or Wilms tumor with an early presentation.
A total of 112 patients (142 kidneys) presented with hydronephrosis consistent with ureteropelvic junction obstruction that had been diagnosed by prenatal ultrasound. The kidneys were classified as having poor, moderate or good function based on isotope imaging at 3 months after birth. Of 9 kidneys that showed poor function 3 recovered sufficient function on pigtail drainage to justify preservation and these patients underwent pyeloplasty. Of 27 kidneys with moderate function 23 also underwent pyeloplasty and 14 of these demonstrated improvement in function postoperatively. Of the 100 kidneys in the good function group that were followed conservatively 23 underwent pyeloplasty during followup primarily because of an observed decrease in function. We propose that there is no indication for immediate pyeloplasty in infants with prenatally diagnosed hydronephrosis who demonstrate good function postnatally.
We evaluated the effect of dipyridamole (5 mg/kg/day) for 12 months on renal and platelet function in 53 children with insulin dependent diabetes mellitus (IDDM) in a prospective double blind placebo controlled trial. Urine albumin excretion (expressed as the geometric mean albumin to creatinine concentration ratio (UA/UC) was measured every three months throughout the study. At 12 months, the geometric mean UA/UC was no different in diabetic children receiving dipyridamole, 0.60 mg/mmol, when compared with those receiving placebo, 0.87 mg/mmol. Glomerular filtration rate, urinary excretion of retinol binding protein, and N-acetyl-beta-D-glucosaminidase (NAG), blood pressure, and spontaneous platelet aggregation in response to stirring whole blood did not differ between the two groups at 12 months. Subgroup analysis to include only those children with high UA/UC before entry into the study also failed to show an effect of the drug on UA/UC. Eleven children had either persistently high UA/UC (n = 8: four on dipyridamole, four on placebo) or progression to high UA/UC (n = 3: two on dipyridamole, one on placebo). These children had significantly higher urinary excretion of retinol binding protein and NAG, bigger kidneys, and higher diastolic blood pressure both before and after treatment than the remaining 42 children, whereas there was no difference in spontaneous platelet aggregation between the two groups. These observations on the associations between UA/UC and other parameters of renal function suggest that measurement of 'tubular' proteins and diastolic blood pressure as well as UA/UC may contribute to the identification of those at risk of developing nephropathy.
Since 1960 we have diagnosed phaeochromocytoma (paraganglioma) in 10 children. The cases include a 15 year old girl who over a three year period presented with multiple paragangliomata and an associated malignant carotid body tumour. All children were hypertensive, eight of 10 presenting with severe headaches. Diagnosis was based on finding a raised urinary vanillylmandelic acid excretion and plasma noradrenaline concentration. In addition six of eight children were hypercalcaemic with raised plasma calcitonin concentrations; plasma parathyroid hormone concentrations were high in two of seven and four out of eight children had raised plasma renin activities on presentation. No child, however, was found to have a multiple endocrine neoplasia syndrome. Despite the introduction of newer techniques for the detection of catecholamine producing tumours we found that selective arteriography and venous catecholamine sampling were superior for tumour localisation compared with ultrasound scanning, computed tomography, and metaiodo-benzyl-guanidine (MIBG) scanning.
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Neutrophil leucocytosis is associated with a poor outcome in the haemolytic uraemic syndrome (HUS). This study tested the hypothesis that neutrophils from HUS patients are activated and through release of their intracellular contents damage endothelium. The proportion of neutrophils adhering to endothelium in culture was twice as high for HUS patients' neutrophils as for control neutrophils (n = 12). In addition, these neutrophils induced endothelial injury, assessed morphologically by degradation of endothelial cell fibronectin. In an attempt to inhibit neutrophil adhesion and subsequent endothelial damage the hyperadhesive neutrophils from HUS patients were incubated with a CD18 antibody directed against the common beta chain of the leucocyte integrin molecules. The CD18 antibody was able to abrogate endothelial damage in four of the ten subjects studied. These observations suggest that the neutrophil is of prime pathophysiological importance in HUS, and that methods aimed at reducing neutrophil adhesion and neutrophil-mediated endothelial damage are likely to be beneficial.
Autosomal dominant (or possibly X-linked) inheritance of familial hypoplastic glomerulocystic kidneys is described in a mother and son who both had stable, chronic renal failure, cystic kidneys by ultrasound examination, glomerular cysts as demonstrated histologically, and malformed renal calyces. There was no evidence of other congenital abnormalities apart from prognathism, small stature and pyloric stenosis. Hepatic fibrosis was not evident in a liver biopsy specimen. These findings add further confirmation to the existence of the syndrome of familial hypoplastic glomerulocystic kidney disease with dominant inheritance.
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 40 ml/min per 1.73 m2 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.
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The variability of urine albumin excretion (UAE) was studied in normal and diabetic children and, in addition, the best method of expressing the data was investigated. In 39 timed overnight urine samples from diabetic children, the urine albumin creatinine clearance ratio (CA/CC) was compared with the urine albumin creatinine concentration ratio (UA/UC), the urine albumin excretion rate (UAER) and the urine albumin concentration (UA). UA/UC predicted CA/CC (r = 0.95) better than either UAER (r = 0.83, P less than 0.02) or UA (r = 0.90), 0.1 greater than P greater than 0.05). The within-individual and the between-individual variability in overnight UA/UC in 171 urine samples from 73 normal children was compared with that of 406 urine samples from 119 diabetic children, using a "random effects type 2 nested analysis of variance" model. Geometric mean (range) UA/UC (mg/mmol) in diabetic children, 0.55 (0.04-6.90), was greater than in normal children, 0.33 (0.05-2.10, P less than 0.01), and 18% of diabetics had a value of UA/UC above the normal range. Within-individual variance was the same in normals (0.12) and diabetics (0.12), but between-individual variance in diabetics (0.18) was much greater than in normals (0.03). These data show that within-individual observations for both normals and diabetics are highly but equally variable. Furthermore, from these data, it is possible to infer that a minimum of five estimations are necessary per individual to estimate the true mean value of urine albumin excretion with reasonable confidence.
Acute renal failure (ARF) is not listed as a usual form of presentation in hypoxanthine-guanine phosphoribosyltransferase deficiency, despite the gross uric acid overproduction in the defect. We found that a third of such patients may present in ARF when the urinary uric acid/creatinine ratio may be normal, not raised, and the defect may be suspected from the disproportionate increase in plasma uric acid. This is important in view of the potential confusion of uric acid with 2,8-dihydroxyadenine, the even more insoluble purine excreted in the other salvage enzyme disorder, adenine phosphoribosyltransferase deficiency. In that disorder, presentation in ARF is well recognized, the uric acid/creatinine ratio is also normal, but plasma urate is not raised. Our combined experience in these two disorders underlines the importance of early recognition and treatment with carefully adjusted doses of allopurinol, which may reverse or postpone renal failure.
Studies using cationic probes have suggested that a reduction in glomerular anionic sites, composed principally of the glycosaminoglycan heparan sulphate, is responsible for the abnormal glomerular permeability in the congenital nephrotic syndrome (CNS). We therefore analysed the glycosaminoglycan content of the glomerular basement membrane (GBM) from an infant who died of CNS and from an infant who died of unrelated causes. We also measured the urinary excretion of glycosaminoglycans in children with nephrotic syndrome, both congenital and acquired, and in healthy children. Heparan sulphate constituted 59% of the glycosaminoglycan content of the GBM in the normal infant, the other principal glycosaminoglycan being chondroitin sulphate. In the GBM from the infant with CNS the heparan sulphate was greatly reduced, constituting only 3% of total glycosaminoglycans. The urinary excretion of heparan sulphate was significantly increased in CNS (expressed both in relation to creatinine and to chondroitin sulphate) compared with normal children and to those with acquired nephrotic syndrome. Diminished GBM content of heparan sulphate may be responsible for the abnormal glomerular permeability in CNS and may be a consequence of defective incorporation of heparan sulphate into the GBM with subsequent loss into the urine.
Review of data from 79 children with the haemolytic uraemic syndrome (HUS) showed that the polymorphonuclear leucocyte (PMN) count at presentation in childhood HUS predicts outcome. Logistic regression analysis of several features at presentation identified only the PMN count and the presence of a diarrhoeal prodrome as having a significant effect on the outcome (P less than 0.01 and P less than 0.001 respectively). The geometric mean PMN count was significantly raised in 70 children who had typical HUS following a diarrhoeal prodrome (D+ cases) compared with that of 9 children who had atypical disease without diarrhoea (D- cases) (t-test on log-transformed data, P less than 0.005). Fifty-seven children with D+ HUS who recovered completely had a significantly lower geometric mean PMN count than D+ cases with a bad outcome (P less than 0.001). Four of these patients, who died in the acute stage of the disease, had a significantly higher mean count than the rest of the D+ patients (P less than 0.001). Multiple regression analysis demonstrated that the PMN count in D+ cases was not significantly influenced by haemoglobin concentration, platelet count, length of the prodrome, or the administration of antibiotics in the prodromal period. A high PMN count at presentation in D+ HUS indicates a poor prognosis. The data emphasise the heterogeneity of HUS and suggest that PMN participate in the pathogenesis of the disorder in typical D+ cases but not in atypical D- cases.
The clinical features of 55 cases of autosomal recessive polycystic kidney disease (ARPCKD) have been reviewed. Each had evidence of ARPCKD. The outcomes of 87% were known; 24 had died. Twenty-four of 31 were seen between 1980 and 1986; 7 could not be traced. Forty-five percent presented under 1 month; 38% between 1 month and 1 year; and 9 cases over 1 year. Hyponatraemia occurred in 15 out of 19 aged less than 3 months; hypertension occurred in 65%; splenomegaly in 47% of those surviving more than 3 months. Portocaval shunts were done in 5 aged 2-12 years. Thirteen died of renal failure, 6 under 1 year, and 7 between 1 year and 13 years. Life-table survival rates calculated from birth revealed that 86% were alive at 3 months, 79% at 1 year, 51% at 10 years, and 46% at 15 years. Calculations based on patients who survived to 1 year of age showed that 82% were alive at 10 years and 79% at 15 years. These results reveal an improved prognosis for a condition once assumed to be fatal.
We postulated that the reduction of surface negative charge on the glomerular capillary wall, which is believed to underlie the proteinuria of steroid-responsive nephrotic syndrome (SRNS), might be due to the presence of a cationic substance which binds to and neutralizes the negative charge on cells and membranes. Using a method to detect charge neutralizing substances based on inhibition of binding of the cationic dye Alcian blue 8GX to heparin, plasma and urine from children with SRNS were found to contain a protease-sensitive charge-neutralizing factor, which was not present in plasma or urine of healthy individuals. This factor has been partially purified from SRNS plasma and urine by ion exchange chromatography on QAE Sephadex, gel filtration on Sephadex G150, and FPLC on Mono-S. This cationic protein, which binds to and neutralizes the charge on heparin, may also neutralize the negative charge on the glomerular capillary wall and may thus be involved in the pathogenesis of SRNS.
The urinary extraction of albumin, retinol binding protein, and N-acetyl-beta-D-glucosaminidase were studied in 60 children with insulin dependent diabetes mellitus and in 45 normal children to find out whether the renal tubules played a part in causing the early increase in urinary excretion of albumin that occurs in diabetes mellitus. Two overnight urine samples were collected and the protein excretion measured and expressed as the geometric mean of the protein to creatinine ratio (urinary albumin:creatinine ratio, urinary retinol binding protein:creatinine ratio, and urinary N-acetyl-beta-D-glucosaminidase:creatinine ratio, respectively). The excretion of all three proteins was significantly higher in the diabetic children with 15 (25%) of urinary albumin:creatinine ratio, 16 (27%) of urinary retinol binding protein:creatinine ratio, and 43 (72%) of urinary N-acetyl-beta-D-glucosaminidase:creatinine ratio values being above the normal range. Significant correlations were observed between urinary albumin:creatinine ratio and urinary retinol binding protein:creatinine ratio, urinary albumin:creatinine ratio and urinary N-acetyl-beta-D-glucosaminidase:creatinine ratio, and urinary retinol binding protein:creatinine ratio and urinary N-acetyl-beta-D-glucosaminidase:creatinine ratio. There were also significant correlations between glycated haemoglobin 1c (HbA1c) and these proteins, especially N-acetyl-beta-D-glucosaminidase. No correlations were observed with the fractional excretion of sodium, flow rate of urine, glomerular filtration rate, or blood pressure. These data show that tubular abnormalities are present early in the course of insulin dependent diabetes mellitus and suggest that the early increase in urinary excretion of albumin may be at least partly tubular in origin, and that glycaemic control may influence this aspect of proximal tubular function.