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Biomedical subjects

H K Yap

Publications and source records attributed to H K Yap.

At least 73 records · Page 4Linked to original sources
PubMed1989

Kawasaki syndrome in Chinese children.

A retrospective analysis of the clinical features and outcome of 39 Chinese children with Kawasaki syndrome was made. The mean age of onset was 2.7 years (range: 0.2-13 years). The male:female ratio was 2.9:1. One child presented with nephrotic syndrome. This renal manifestation has not been described in Kawasaki disease. Ten (32%) out of 31 patients were found to have coronary aneurysms by cross-sectional echocardiography. The only significant risk factor detected in this group of patients was anaemia (P less than 0.007). There was one (2.5%) death from acute myocardial infarction and the rest of the patients were clinically well with a mean follow-up period of 1 year (mean: 5-40 days). This study indicates that there is a high incidence of coronary aneurysm complicating Kawasaki syndrome in Chinese comparable with that reported in Japanese children.

Child, Preschool↗
PubMed1989

Nephrotic syndrome in Kawasaki disease.

Renal manifestations in Kawasaki disease are rare, and nephrotic syndrome in this disorder has not been described previously. We report a 3 month old infant with Kawasaki disease, presenting with nephrotic syndrome which responded to steroid therapy. The patient, however, developed coronary aneurysms and died of acute myocardial infarction.

Acute Disease↗
PubMed1989

Protein selectivity: a prognostic index in IgA nephritis.

Among 98 patients with IgA nephritis who had protein selectivity studies performed, 54% had nonselective proteinuria and the remaining 46% had selective proteinuria. Patients with nonselective proteinuria had a higher incidence of glomerulosclerosis. At the end of a 4-year follow-up period, patients with nonselective proteinuria had lower creatinine clearance, higher incidence of hypertension and chronic renal failure when compared to patients with selective proteinuria. Six out of eleven patients (55%) in the study who had the nephrotic syndrome had selective proteinuria. Among these 6 patients, 1 had spontaneous remission and 5 responded to steroid or cyclophosphamide therapy. The remaining 5 patients with nonselective proteinuria did not respond to therapy. In the patients who had selectivity studies repeated, the data showed that the selectivity index (SI) can fluctuate depending on the clinical course of the patients. SI can therefore be used to monitor the progress of patients on long-term follow-up. Protein selectivity appears to be a useful prognostic index in IgA nephritis. For patients with the nephrotic syndrome it may serve as a guide to therapy.

Adult↗
PubMed1989

Pattern of glomerulonephritis in Singapore children--a renal biopsy perspective.

This study was aimed at determining the pattern of glomerulonephritis (GN) in Singapore children from a histopathological perspective. Fifty-seven consecutive children, aged between 10 weeks to 16 years, who underwent a renal biopsy at the Departments of Paediatrics, National University of Singapore and Singapore General Hospital over an 8 year period were studied. The main indications for biopsy were nephrotic syndrome (67%), recurrent gross haematuria (16%), nephritic syndrome (7%), and renal failure (10%). Primary GN occurred in 81%, while secondary GN was seen in 19%, the most common being lupus nephritis. Of the primary GN, minor abnormalities was the most common (22%), followed by focal global sclerosis (20%), focal segmental glomerulosclerosis (17%), diffuse mesangial proliferative GN (11%), focal mesangial proliferative GN (9%), membranous GN (7%), diffuse endocapillary GN (4%), diffuse sclerosing GN (4%), diffuse mesangial sclerosis (4%), and diffuse crescentic GN (2%). Immunofluorescent examination was performed in 50 children. IgA nephropathy was diagnosed in 17% of the patients with primary GN. Of the children with primary nephrotic syndrome due to minimal change disease or focal global sclerosis, about half had IgM mesangial deposits. Of 47 patients who were followed up, 9 developed chronic renal failure, of which 7 reached end-stage disease (4 have died, while 3 are on chronic dialysis). Three other patients died of other complications. The histopathological findings influenced the therapeutic decision in 49% of our patients. In summary, the pattern of GN in our cohort of patients tended to reflect more severe glomerular lesions, mainly due to our criteria of selection for renal biopsy.

Adolescent↗
PubMed1988

Anti-vascular endothelial cell antibodies in patients with IgA nephropathy: frequency and clinical significance.

This study examined the frequency of anti-vascular endothelial cell (VEC) antibodies (Ab) in 72 patients with IgA nephropathy (IgAN), and their possible relationship to clinical and histological parameters of the disease. An enzyme immunoassay was developed to measure the binding of sera to endothelial cells grown to a confluent monolayer. Thirty-two percent of IgAN patients had serum anti-VEC activity as compared to 4% of controls (P = 0.004) and 9% of patients with other primary glomerulonephritis (P = 0.017). This was shown to be due to anti-HLA class I Abs in 6 of the 23 IgAN patients, and in the 1 control positive for anti-VEC activity. Hence 17 IgAN patients had anti-VEC Abs, predominantly of the IgA subclass. Stimulation of the endothelial cells with interferon-gamma and interleukin 1 did not increase the binding of these Abs. There was no correlation with circulating immune complex (IC) levels, and removal of ICs in positive sera by ultracentrifugation did not decrease anti-VEC binding. Significant correlations were found between anti-VEC Abs and proteinuria greater than 1 g/day (P = 0.044), as well as IgA anti-VEC Abs and C3 or IgA deposition in renal arterioles (P = 0.048). These IgA Abs may be an important marker of pathogenetic activity in IgAN.

Adolescent↗
PubMed1988

Controlled therapeutic trial of IgA nephritis with follow-up renal biopsies.

Forty-eight patients with IgA nephritis entered a 3 year controlled prospective trial using a combination regimen of cyclophosphamide for 6 months and dipyridamole and low dose warfarin for 36 months. Those in the treatment group (n = 27) had stable renal function and a significant decrease in proteinuria (p less than 0.01) but in the controlled group (n = 21) there was a significant fall in creatinine clearance (p less than 0.01) and rise in serum creatinine (p less than 0.02) with no change in proteinuria. The data suggested that the above treatment resulted in a significant reduction of proteinuria and more stable renal function. Eleven patients in the treatment group and 10 patients in the controlled group had repeat renal biopsies after the trial. Eight parameters were used in the evaluation of the renal biopsies: mesangial hypercellularity, crescents, tuft adhesion, segmental sclerosis, global sclerosis, tubular atrophy, interstitial fibrosis and vascular sclerosis. Each lesion was graded from 0 to 3 and a total scoring system used for evaluation of histological severity. In the treatment group there was no significant histological deterioration but in the controlled group there was progressive histological deterioration. Mean total histological score was 3.7 +/- 2.6 before the trial and 6.5 +/- 3.1 after the trial (p less than 0.05). This histological progression appeared to run parallel with the clinical course.

Biopsy, Needle↗
PubMed1987

Detection of bovine serum albumin in the circulating IgA immune complexes of patients with IgA nephropathy.

Alimentary antigenic challenge has been postulated to have a role in the genesis of IgA circulating immune complexes (CIC), resulting in mesangial IgA disease. In this study, we examined the relationship between bovine serum albumin (BSA) and IgA CIC in patients with IgA nephropathy. Of the 47 patients studied, elevated IgA CIC levels were found in 32% by the F(ab')2 anti-C3 and Raji cell enzyme immunoassays (EIA). Elevated IgA anti-BSA antibody levels were found in 9 patients, and there was a positive correlation between these levels and IgA CIC as measured in the Raji cell EIA (R = 0.60, P less than 0.001). In 4 patients with elevation of both IgA CIC and IgA anti-BSA antibody levels, solubilization experiments were done to demonstrate the presence of BSA antigen in the IgA CIC. Using the Raji cell EIA, the IgA CIC levels decreased significantly after preincubating the sera with serial concentrations of excess BSA. No corresponding effect was seen with human serum albumin used as control. Hence, BSA may be the antigenic stimulus in the formation of IgA CIC in selected patients with IgA nephropathy. The pathogenic capacity of these IgA-BSA CIC remains to be determined.

Adolescent↗
PubMed1987

Hernias: a frequent complication in children treated with continuous peritoneal dialysis.

The course of 93 children, treated with continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD) over a total of 1,819 months, was evaluated retrospectively regarding hernia development. Thirty-seven patients (40%) developed 60 hernias (one per 30 patient-months), of which 36 were ventral, 7 umbilical, 14 inguinal, and 3 scrotal. Hernia occurrence was inversely correlated to patient's age and duration of CAPD/CCPD. The rate of hernia development was highest within the first 3 months following initiation of CAPD/CCPD with a subsequent rapid decrease. The dialysate inflow volume was not related to hernia development. The only complication due to the presence of a hernia was one episode of incarceration of the small bowel that required immediate surgical intervention. Surgical repair was the treatment performed in 75% of the cases. The remaining hernias were managed with volume reduction, conversion from CAPD to CCPD, or discontinuation of the daytime dialysate dwell in patients undergoing CCPD. Our observations suggest that hernia development is a frequent complication in children treated with CAPD/CCPD.

Adolescent↗
PubMed1987

A 10 year review of systemic lupus erythematosus in Singapore children.

A 10 year retrospective analysis of the clinical features and survival of 24 Singapore children with systemic lupus erythematosus was made. The female to male sex ratio was 11:1. The median age at diagnosis was 9.3 years (range: 3.5-17.6 years), and the median duration of follow-up was 3.6 years (range: 3 months-10 years). The common modes of presentation were prolonged fever and malar rash (both 46%). Renal involvement (71%) was frequent. There were six deaths, three from chronic renal failure, two from infection, and one from carditis. The overall survival at 5 years was 0.800 (s.e.m. = 0.090), and at 10 years 0.698 (s.e.m. = 0.103). The survival for lupus nephritis was 0.727 at 5 years (s.e.m. = 0.116), and 0.586 at 10 years (s.e.m. = 0.130). Although the 5 year survival rate is comparable with other series, there were more deaths after the first 5 years, and morbidity from the disease as well as from therapy was considerable.

Adolescent↗
PubMed1987

Acute renal allograft rejection. Comparative value of ultrasound versus magnetic resonance imaging.

Both magnetic resonance imaging (MRI) and ultrasound (US) have been reported to be useful in differentiating between acute allograft rejection and other causes of graft dysfunction in renal transplantation. The aim of this study was to evaluate the comparative usefulness of these techniques in the assessment of patients with acutely rising serum creatinine levels. Seventeen patients with 19 episodes of acute serum creatinine elevations were evaluated for the presence of acute rejection. The ultimate diagnoses of acute rejection were based on either renal pathological findings, or the response to standard antirejection therapy. Clinical, US and MRI diagnoses were assessed independently, without knowledge of the results of the other evaluation techniques. We found that US alone was useful in diagnosing acute rejection (x2 = 4.95, P less than 0.05), and when taken in the clinical setting was an added advantage (x2 = 6.68, P less than 0.01). MRI did not increase the diagnostic accuracy significantly.

Adolescent↗
PubMed1987

Effects of triple therapy on the progression of mesangial proliferative glomerulonephritis.

Fifty-two pairs of patients with idiopathic diffuse mesangial proliferative glomerulonephritis entered a controlled 3-year prospective trial of a combination regimen of cyclophosphamide, dipyridamole and warfarin. In the treatment group proteinuria decreased significantly (p less than 0.01) and renal function remained stable, but in the control group there was no change in proteinuria and creatinine clearance (Ccr) decreased significantly (p less than 0.01). The time patients with renal impairment in the control group and those in the treatment group took to reach end stage renal failure was significantly different (6.1 years versus 8.9 years, p less than 0.02). Among the patients with IgA nephritis, those in the treatment group (n = 27) had stable renal function and a significant decrease in proteinuria (p less than 0.01) but in the control group (n = 21) there was a significant fall in Ccr (p less than 0.01) and rise in serum creatinine (p less than 0.02) with no change in proteinuria. Among 23 pairs of patients in the study who were matched for renal function and degree of glomerulosclerosis, those in the treatment group had stable renal function and decrease in proteinuria (p less than 0.01) whereas those in the control group had decreased Ccr (p less than 0.01) but no change in proteinuria.

Adult↗
PubMed1985

Glucose tolerance test and insulin levels in children with transfusion-dependent thalassaemia.

Blood glucose and serum immunoreactive insulin levels were measured following an oral glucose load in 20 unrelated children with multiple transfused thalassaemia. Results suggest that even though overt diabetes and glucose intolerance are uncommon before the age of 13 years, the presence of insulin resistance is evident, especially in those who have been splenectomized.

Adolescent↗
PubMed1985

Estimation of glomerular filtration rate in children using 99m-technetium DTPA. A comparison with 51-chromium EDTA clearance.

The usefulness of radionuclide imaging studies with 99m-technetium diethylenetriaminepentaacetic acid (Tc-DTPA) for quantitating the glomerular filtration rate (GFR) in children was studied. This was compared to the conventional methods for measuring GFR using 51-chromium-EDTA clearance (Cr-EDTA), creatinine clearance and a height/plasma creatinine formula. In the 22 children studied, the correlation coefficient between renal uptake of DTPA and Cr-EDTA was 0.90 (p less than 0.001). In contrast, there was a poorer correlation between Cr-EDTA and creatinine clearance (r = 0.69) or the derived GFR using height/creatinine formula (r = 0.83). The regression line between Tc-DTPA uptake and Cr-EDTA clearance was used to derive a formula for calculating the predicted GFR. This was tested in 10 additional children, and the correlation between the predicted GFR and measured GFR (using Cr-EDTA clearance studies) was 0.92 (p less than 0.001). Quantitative estimation of the GFR during renal imaging studies is a feasible and convenient method of assessing renal function.

Adolescent↗