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Biomedical subjects

V Shah

Publications and source records attributed to V Shah.

At least 127 records · Page 7Linked to original sources
PubMed1993

Sodium-lithium countertransport and family history of hypertension in childhood.

We have studied the relationship between sodium-lithium countertransport, determined in childhood, and family history of hypertension. Countertransport was measured in healthy children and those with secondary hypertension. There was no significant difference in countertransport between these two groups. In the normal children (n = 52, median age 6.8 years), there was a positive relationship between body mass index and countertransport (rs = 0.34, p < 0.02). A positive relationship between family history of hypertension using a ranked scoring system, and countertransport, not related to age, body mass or blood pressure (n = 34, rs = 0.63, p < 0.001) was also found. There was no significant relationship between intracellular sodium concentration and countertransport. These data confirm that countertransport in normal children is related to body mass index and indicate that a genetic predisposition to primary hypertension marked by sodium-lithium countertransport is identifiable in childhood.

Adolescent↗
PubMed1993

Tubular proteinuria in steroid sensitive multi-relapsing nephrotic syndrome.

The urinary excretion of N-acetyl-beta-D-glucosaminidase (UNAG) and retinol binding protein (URBP) was studied in 65 children with steroid sensitive multirelapsing nephrotic syndrome (MRNS): 28 on cyclosporin A (CyA) therapy, 22 on prednisolone (P), 15 off-treatment and in 32 normal children to assess renal tubular damage or dysfunction. The urinary protein excretion was expressed in relation to that of creatinine (UNAG/UC in mumol pnp/h/mmol; URBP/UC in microgram/mmol). There was a weak but significantly negative correlation between age and both, UNAG/UC (r = -0.38, p < 0.01) and URBP/UC (r = -0.50, p < 0.05) in normal children, but not in nephrotics. In normals and in patients off steroids an association between these two proteins was found (r = 0.38, p < 0.05; r = 0.56, p < 0.05 respectively). Geometric mean UNAG/UC was significantly higher in nephrotics on CyA therapy (26.5 +/- 4.0), and on P (37.0 +/- 7.9) as well as in those off-treatment (16.3 +/- 3.1) compared to normal children (9.3 +/- 3.4). There was a further increase in those with raised urinary albumin: creatinine ratio (UA/UC) (> 0.1 mg/mg). URBP/UC was not increased in any of the groups of children with MRNS. Raised NAG in urine may therefore indicate active nephrotic syndrome rather than being due to the drug therapy.

Acetylglucosaminidase↗
PubMed1993

Reduction of cerebral perfusion precedes rise of intracranial pressure in rats with ischemic fulminant liver failure.

In fulminant liver failure, brain edema may progress to intracranial hypertension. However, the rise in intracranial pressure is a late event in this sequence. We investigated the relationship between cerebral perfusion and development of intracranial hypertension in a well-characterized model of fulminant liver failure, the rat subjected to hepatic devascularization (n = 11). In addition, we examined the effects of hyperglycemia on the development of brain edema because high blood glucose level can exacerbate other forms of brain edema, as seen in stroke. Intracranial pressure was continuously monitored with a cisterna magna catheter; relative changes in blood flow were continuously assessed with a Doppler flow probe on the internal carotid artery. Cerebral perfusion decreased by 62%, with the greatest reduction before the onset of increased intracranial pressure. Intracranial pressure did not change until 2 hr before death, at which time it increased exponentially. Brain water in fulminant liver failure rats was significantly increased compared with that in controls. Hyperglycemia (200 to 220 mg/dl) had no effect on time elapsed until loss of corneal reflex, percentage of brain water, maximal intracranial pressure or pattern of change in cerebral perfusion compared with euglycemia (80 to 100 mg/dl). Sham-operated animals showed no changes in measured parameters. We conclude that a linear reduction in cerebral perfusion precedes the rise of intracranial pressure in this model, a decrease that may reflect changes in brain metabolic activity at the time that brain edema develops. Carotid blood flow monitoring may be a useful noninvasive tool for the detection of cerebral events in fulminant liver failure.

Animals↗
PubMed1992

Urinary endothelin (ET1) in complete ureteric obstruction in the miniature pig.

Segmental renal scarring occurs in experimental obstructive uropathy in the multipapillary porcine kidney, and segmental abnormalities in renal perfusion are likely to be responsible. This preliminary study examines the urinary excretion of the potent locally active vasoconstrictor endothelin 1 (ET 1) in a pig model of renal obstruction and subsequent relief. Significant urinary excretion of ET 1 from the postobstructive kidney was found to occur after longstanding obstruction. Preglomerular arteriolar stenosis may be the cause of the renal ischaemia in obstruction that is at first reversible but later becomes irreversible if the stimulus persists. ET 1 may be implicated in the pathogenesis of this injury.

Animals↗
PubMed1992

Neutrophil activation in the haemolytic uraemic syndrome: free and complexed elastase in plasma.

There is evidence of neutrophil involvement in the pathogenesis of the haemolytic uraemic syndrome (HUS), and neutrophil release products are thought to cause endothelial cell damage. Elastase is the major lysosomal proteinase liberated by activated neutrophils. In this study we measured both free and complexed elastase. No free elastase activity could be detected in the plasma of patients with diarrhoea-associated (D+) HUS using a specific substrate. However, there was a marked increase in alpha 1-antitrypsin (alpha 1-AT) complexed elastase as measured by a newly developed enzyme-linked immunosorbent assay not only in D+ HUS, but also in non-diarrhoea-associated (D-) HUS. This finding is independent of either a high polymorphonuclear leucocyte count or renal failure. This increase in bound elastase together with our sequential data which demonstrate raised alpha 1-AT complexed elastase levels early in the disease process further support the theory that neutrophil activation is one of the key events in the pathophysiology of this disorder.

Adult↗
PubMed1992

Aging persons' estimates of vehicular motion.

Estimated arrival times of moving autos were examined in relation to viewer age, gender, motion trajectory, and velocity. Direct push-button judgments were compared with verbal estimates derived from velocity and distance, which were based on assumptions that perceivers compute arrival time from perceived distance and velocity. Experiment 1 showed that direct estimates of younger Ss were most accurate. Older women made the shortest (highly cautious) estimates of when cars would arrive. Verbal estimates were much lower than direct estimates, with little correlation between them. Experiment 2 extended target distances and velocities of targets, with the results replicating the main findings of Experiment 1. Judgment accuracy increased with target velocity, and verbal estimates were again poorer estimates of arrival time than direct ones, with different patterns of findings. Using verbal estimates to approximate judgments in traffic situations appears questionable.

Acceleration↗
PubMed1992

Interleukin-8 and polymorphoneutrophil leucocyte activation in hemolytic uremic syndrome of childhood.

Polymorphoneutrophil leucocytes (PMNLs) are implicated in the pathogenesis of diarrhea-associated hemolytic uremic syndrome (D+ HUS). We investigated mechanisms of PMNL involvement by measuring tumor necrosis factor alpha (TNF alpha) and the novel cytokine, interleukin-8 (IL-8), a potent activator of neutrophils, together with alpha 1- antitrypsin-complexed elastase (alpha 1-AT-E) as a marker of neutrophil degranulation, and anti-neutrophil cytoplasmic antibodies (ANCA). IL-8 was not detected in the 17 normal children, but was significantly elevated in 20 of 25 D+ HUS children (P less than 0.005), and in three of nine children with non-diarrhea-associated (D-) HUS. Sequential data showed that IL-8 peaked transiently in the circulation, reaching a maximum just before a more protracted burst of alpha 1-AT-E. The IL-8 levels correlated significantly with circulating alpha 1-AT-E concentrations (r = 0.50, P less than 0.05). In D+ HUS IL-8 levels also correlated with the PMNL count (r = 0.63, P less than 0.005), and the highest values were seen in those children who died in the acute phase of the disease. TNF alpha was raised in only 1 of 16 D+ HUS children and in no patients were ANCA detected. The data suggest that PMNLs in HUS are recruited by IL-8, that this cytokine plays a key role in the PMNL activation which occurs, and that agents which suppress this recruitment and activation might play a therapeutic role in this disorder.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1992

Survival prospects of extremely preterm infants: a 10-year experience in a single perinatal center.

During a 10-year period, 1977 to 1986, 233 (53%) of 442 inborn live births between 23 and 28 weeks' gestation survived; their 1-year survival rate was 7% at 23 weeks, 30% at 24 weeks, 31% at 25 weeks, 55% at 26 weeks, 67% at 27 weeks, and 71% at 28 weeks. No significant change in survival rate was observed over the years. Twelve percent of pregnancies and 20% of infants were multiple gestations. Singleton births had significantly higher survival rates compared with multiple births (58% versus 41%). The obstetric intervention rate, as measured by the frequency of cesarean section, increased significantly over the years: from 15% in 1977-1978 to 33% in 1985-1986. The neonatal intervention rate, as measured by the frequency of live births offered neonatal intensive care, remained unchanged. Ten percent were not treated: 4% had major malformations and 6% were considered "nonviable." Active perinatal management, which assumed fetal-neonatal viability, accounted for better survival rates compared with centers with a more passive management policy. Information on survival based on gestational cohorts plays an important role in helping obstetricians, neonatologists, and parents make appropriate management decisions.

Cesarean Section↗
PubMed1991

Long term renal outcome of childhood haemolytic uraemic syndrome.

OBJECTIVE: To evaluate the long term outcome of renal function in infants and children after diarrhoea associated haemolytic uraemic syndrome. SETTING: The Hospital for Sick Children, Great Ormond Street, and the Royal Free Hospital, London. SUBJECTS: 103 children with the syndrome who presented between 1966 and 1985; 88 attended for follow up investigations (40 male, 48 female) with a mean age 11.6 (range 5.2-22.6) years and a mean duration of follow up of 8.5 (range 5.1-21.3) years. MAIN OUTCOME MEASURES: Blood pressure, ratio of early morning urine albumin to creatinine concentration, glomerular filtration rate, and plasma renin activity. RESULTS: The mean (SD) systolic blood pressure standard deviation score was 0.38 (0.67) and diastolic blood pressure SD score was 0.10 (0.76). The geometric mean ratio of overnight urine albumin to creatinine concentration was 1.27 (range 0.03-48.2), significantly higher than the value observed in 77 normal children (0.32 (0.05-1.95), p less than 0.0001). Glomerular filtration rate estimated from the plasma clearance of chromium-51 EDTA was 95.1 (22.7) ml/min/1.73 m2 surface area, and 16 children had a rate of less than or equal to 80 ml/min/1.73 m2. Significant negative correlations were found between glomerular filtration rate and urinary albumin to creatinine ratio (r = -0.41, p less than 0.0001) and glomerular filtration rate and systolic blood pressure SD score (r = -0.48, p less than 0.0001). A significant positive correlation was found between urinary albumin to creatinine ratio and systolic blood pressure SD score (r = 0.25, p = 0.02). CONCLUSIONS: After an acute episode of diarrhoea associated haemolytic uraemic syndrome 31% (27/88) of children had an increased albumin excretion, 18% (16/88) had a reduced glomerular filtration rate and 10% (9/88) had both, in association with a higher systolic blood pressure, indicating considerable residual nephropathy in this group.

Adolescent↗
PubMed1991

Duration of hospitalization in extremely preterm infants.

This study reports the age at hospital discharge of 233 survivors and age at death of 209 infants who were born at 23-28 weeks gestation over a 10 year period, 1977-86. The mean duration of hospitalization of survivors was 95 days and was inversely related to maturity at birth; those born at 23-25 weeks remained in hospital on average 1-2 weeks beyond term while those born at 26-28 weeks went home on average at term or 1 week before term. The mean age at death was 12 days: 53% within 1 day, 23% between 2 and 7 days, 15% between 8 and 28 days and 9% between 28 days and 1 year. The proportions of death in the post-neonatal period for infants born at 23-24 weeks, 25-26 weeks and 27-28 weeks were 2, 9 and 16% respectively. There was no significant trend in prolonged hospitalization of survivors or postponement of neonatal deaths to the post-neonatal period over the 1977-86 period. Nevertheless, both neonatal and post-neonatal mortality should continually be monitored in this extremely preterm group.

Gestational Age↗
PubMed1991

Prediction of blood pressure from plasma renin activity in reflux nephropathy.

As there is a 10% risk of hypertension developing in children with reflux nephropathy and the renin-angiotensin system has been implicated in its aetiology, a long term prospective study has been undertaken to explore the relationship between plasma renin activity (PRA) and blood pressure in such patients. In 1978, of 100 normotensive children with reflux nephropathy 8% were shown to have PRA above normal. Five years later of 85 subjects suitable for analysis 13% had increased PRA and it was shown that PRA and blood pressure SD scores significantly increased. The present study refers to the 10 year follow up in which 95 of the original group were traced but eight of these were unavailable for study and 28 others were excluded from analysis because of extraneous factors that might influence blood pressure or PRA. Results therefore on 59 have been analysed. PRA was above normal in 13/59 (20%) subjects, and PRA and blood pressure SD scores had further increased. The data continue to support the role of the renin-angiotensin system in the observed rise of blood pressure in reflux nephropathy, but individual PRA measurements do not appear so far to predict reliably the onset of hypertension in affected patients.

Adolescent↗
PubMed1991

Elevated activity of low molecular weight insulin-like growth factor-binding proteins in sera of vitamin C-deficient and fasted guinea pigs.

We have previously reported that scorbutic and fasted guinea pig sera contain an insulin-like growth factor-I (IGF-I)-reversible inhibitor of collagen, proteoglycan, and DNA synthesis in cultured cells. Here we report that IGF-binding protein (IGFBP) activity is increased in serum containing the inhibitor [125I]IGF-I or -II bound to these sera was eluted in the 30- to 50-kDa region of an S200 gel column. [125I]IGF-I affinity cross-linking analysis revealed that a 38-kDa cross-linked species increased markedly in fasted and scorbutic sera, with a lesser increase in a 34-kDa species, while scorbutic sera also yielded a 44-kDa species. Gel filtration of unlabeled sera showed a 10-fold increase in the activity of two proteins in the 30- to 50-kDa region from the experimental sera. Their activity correlated with their ability to inhibit binding of [125I]IGF-I to its cellular receptor, suggesting that they have the potential to inhibit IGF-I-dependent functions. Ligand blotting showed that 29 and 35-kDa IGFBPs were almost undetectable in normal serum, but were dramatically induced by scurvy and fasting, so that they accounted for close to 40% of the total circulating BPs. Total IGFBP-3 in the experimental sera was increased about 30%, while there was little effect of scurvy or fasting on the level of BP-3 activity isolated by acid extraction of the high mol wt region of the S200 column. An IGF-I analog with normal affinity for the 30- to 50-kDa BPs from fasted and scorbutic sera, but with reduced affinity for the cell receptor, was equivalent to IGF-I in reversing the inhibition of collagen synthesis by scorbutic guinea pig serum in human fibroblasts. Thus, reversal of inhibition appears to require initial saturation of IGFBPs. The overall results suggest that two circulating IGFBPs with unoccupied binding sites are induced in vitamin C-deficient or fasted guinea pigs and may be responsible for inhibition of IGF-I-dependent functions by sera from these animals.

Animals↗
PubMed1990

Glycemic index of traditional Indian carbohydrate foods.

The glycemic index (GI) was determined in 36 non-insulin-dependent diabetes mellitus patients who were fed 50 g carbohydrate portions of six Indian conventional foods, including rice, a combination of rice-legume (Bengalgram, peas, and greengram), and a combination of rice-dal (greengram dal and redgram dal -- dal is dehusked and split legume). In addition to the GI, triglyceride (TG) responses of these foods were also determined. A higher GI was obtained for rice and for rice with peas; all other combinations yielded lower glycemic indices. However, all the foods produced significantly lower blood glucose response 2 hours postprandially as compared with blood glucose responses to a 50 g glucose load for the same group. No significant difference was observed for TG responses to the different foods.

Blood Glucose↗
PubMed1990

Red cell membrane sodium transport: possible genetic role and use in identifying patients at risk of essential hypertension.

To investigate the influence of a family history of essential hypertension on abnormalities of red cell membrane sodium transport, 28 hypertensive children and their families were studied. In 15 families one or both parents had either essential hypertension or a strong family history. In 13 families neither parent had essential hypertension or a positive family history. There were significant differences between the children with a positive family history of essential hypertension compared with those without. Values are expressed as mean (SD): intracellular sodium concentration (mmol/l cells) 8.19 (2.18) compared with 6.41 (0.98); sodium efflux rate constant 0.4873 (0.1379) compared with 0.5831 (0.1104); and numbers of sodium-potassium ATPase pump sites (BMax) (nmol/l cells) 7.96 (1.71) compared with 9.56 (1.7). Significant differences were also found when the index hypertensive children were excluded and the normotensive siblings with and without hypertensive family histories were compared. These data suggest that abnormal red cell membrane sodium transport has a familial component, and although it is not caused by the hypertension it may be the earliest pathophysiological step in its development, perhaps allowing the identification of children at risk of essential hypertension.

Adolescent↗
PubMed1990

Plasma renin activity in fetal disease.

Fetal plasma renin activity (PRA) was measured in 42 pregnancies. Compared to control fetuses, PRA was elevated in three of four hypoxemic fetuses, in two of five with hydrops and in two of five with uropathies. PRA did not change with transfusion in seven alloimmunized fetuses. This study demonstrates PRA in human fetuses and suggests that the renin-angiotensin system can respond to stimuli in fetal life.

Fetal Diseases↗
PubMed1990

Purification and properties of alpha-galactosidase from Klebsiella Sp. No. PG-2.

alpha-Galactosidase has been purified from Klebsiella Sp. No. PG-2, a bacterium isolated from rat small intestine, using calcium phosphate gel, DEAE-cellulose column chromatography and gel filtration technique. About 130-fold increase in specific activity was observed, the pH optimum of 6.5-7.0 characterizes the enzyme as neutral alpha-galactosidase. The optimum temperature was 37 degrees C and the energy of activation was 11,856 cal/mole. Km values obtained for raffinose, mellibose, stachyose and p-nitrophenyl-alpha-D-galactopyranoside were 20.0, 6.6 33.3 and 4.0 mM respectively. The activity was inhibited by p-CMB; iodoacetate, Ag2+, Hg2+, Cu2+, Pb2+ and galactose. Examination of the enzyme activity indicated that the enzyme is cytosolic and is inducible in nature.

Galactosidases↗