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Biomedical subjects

S P Yeung

Publications and source records attributed to S P Yeung.

5 recordsLinked to original sources
PubMed1994

Clinical and histological correlations of decline in renal function in diabetic patients with proteinuria.

In 47 patients with diabetic nephropathy (29 type I, 18 type II) renal function and blood pressure (BP) (treated with or without an angiotensin-converting enzyme [ACE] inhibitor, enalapril [10 mg], in 38 hypertensive patients) were followed over 4 years. A percutaneous renal biopsy was performed in all patients initially and repeated in a representative 19 patients with treated hypertension after 4 years. Mean glomerular volume (MGV), interstitial fibrosis (IF), capillary volume, and sclerosed glomeruli (GS) were measured histomorphometrically. Mean fall in creatinine clearance (CCr) was 11.8% after 4 years with no difference between treatment groups or type of diabetes. BP both initially and during treatment correlated with initial and final serum creatinine and CCr (P < 0.01). There were no histomorphometric differences between type I and type II patients or hypertension treatment groups. Initial IF correlated with initial and final serum creatinine and CCr (P < 0.05) in all patients and type I patients alone, MGV correlated inversely with CCr in type I patients (P < 0.05). After 4 years, IF (24.8 vs. 30.0%, P < 0.01) and GS (26 vs. 37%, P < 0.05) increased significantly, and increase in IF correlated with fall in CCr (P < 0.01). Proteinuria and HbA1 did not correlate with indexes of function or structure. In this longitudinal study of patients with diabetic nephropathy, there was a close relation between BP and renal function but no difference between treatment with enalapril and other hypertensive agents. The correlations between renal function and histology at entry and after 4 years suggest that IF is a co-determinant of renal function in diabetic nephropathy.

Adolescent↗
PubMed1990

Follicular fluid renin concentration and IVF outcome.

Total renin protein concentration (TRC) was measured in stored follicular fluid (FF) samples from 42 women. Samples were selected according to their origin from follicles either without recovered ova ('empty', n = 38) or fertilized but with failed implantation ('failed', n = 36) or successful deliveries ('deliveries', n = 71). Ratios of number of embryos transferred to number of infants delivered were 2:1, 3:1 or 4:2 but 1:1 was not available. Non-parametric testing was applied to FF-TRC, volume and outcome. TRC was significantly higher in the delivery than the failed (P = 0.001) or empty (P = 0.002) categories. Assuming that the range of renin in failed follicles can identify the sub-population of unsuccessful follicles in the delivery category, then elevated FF-TRC was clearly associated with successful outcome. For individual women, the odds of infant delivery increased 17-fold as a function of average FF-TRC between 10,000 and 25,000 microIU/ml. For failed and delivery but not empty follicles, higher renin levels occurred in the smaller follicles, consistent with a burst of renin synthesis associated with the presence of an oocyte. The results suggest that FF-TRC relates to ovum viability with ovarian hyperstimulation and may have predictive use in IVF programmes.

Female↗
PubMed1989

Lambda-light-chain-mediated anti-GBM disease.

A 77-year-old man presented with macroscopic haematuria and oligo-anuric renal failure. A renal biopsy showed moderate linear glomerular basement membrane (GBM) staining with lambda light chains alone, but both circulating IgG and lambda light chain activity were present. There was no evidence of a serum or urinary paraprotein and a bone marrow biopsy was normal. Serum lambda light chains did not bind to renal GBM when examined by indirect immunofluorescence. This case suggests that light chains are capable of binding directly to epitopes in the GBM and may initiate injury although by a different mechanism from the IgG anti-GBM molecule.

Aged↗
PubMed1989

Two ELISAs to detect anti-neutrophil cytoplasm antibodies (ANCA) in various vasculitides.

Anti-neutrophil cytoplasm antibodies (ANCA) are present in the serum of patients with Wegener's granulomatosis, microscopic polyarteritis, and some other small vessel vasculitides. There are at least 2 different anti-neutrophil cytoplasm antibodies identified by their distinctive cytoplasmic staining patterns on indirect immunofluorescence examination. The only antigen identified to date is myeloperoxidase which has a perinuclear distribution on alcohol-fixed neutrophils and monocytes. We have established an ELISA that detects all anti-neutrophil cytoplasm antibodies and one specific for anti-myeloperoxidase antibodies. In the ELISA for anti-neutrophil cytoplasm antibodies, all sera with diffuse cytoplasmic or perinuclear neutrophil staining on indirect immunofluorescence examination bound at levels greater than the normal range (34%, m + 4SD). Three convalescent sera that were negative by indirect immunofluorescence examination were also negative in the assay. Positive sera could be detected at a dilution of 2 and inhibition studies showed that the binding was specific for the neutrophil extract. However, the presence of anti-neutrophil antibodies (ANA), anti-mitochondrial antibodies or immune complexes resulted occasionally in binding in the positive range. Where positive binding was noted in non-vasculitic segmental necrotizing glomerulonephritis, the binding could not be inhibited by pre-incubation with the neutrophil extract. The ELISA for ANCA is a sensitive, objective screening technique that can be performed in parallel with the assay for anti-glomerular basement antibodies to exclude the presence of anti-neutrophil cytoplasm antibodies in patients presenting with rapidly progressive glomerulonephritis. The ELISA for anti-myeloperoxidase antibodies may identify a subset of patients with distinct clinical or prognostic features.

Cytoplasm↗