Biomedical subjects

J Tai

Publications and source records attributed to J Tai.

93 records · Page 6Linked to original sources

PubMedDate not supplied

Evaluation of Micro-Bumintest reagent tablets for screening of microalbuminuria.

The presence of significant microalbuminuria is an important predictor of early diabetic nephropathy. Currently methods available to detect microalbuminuria are not suitable for routine screening. This study assessed the performance of Micro-Bumintest reagent tablets (Ames Laboratory) as a visual screening test for qualitative measurement of urinary albumin. 150 urine specimens from type 1 diabetic patients with a disease duration of less than 1-19 years were assayed over 15 runs using quantitative albumin (radioimmunoassay) and total protein assays. In parallel, 600 determinants were made with the tablets. Each sample was assessed by two readers using a color chart with patterns illustrating typical negative and positive color reactions with a grading from 1 to 7. Urinary protein was determined with an Ames Clinitek 10 urine chemistry analyzer and the Multistix 10 SG reagent strips. The results revealed that as the albumin concentration increased, the percentage of specimens detected visually as presumptive positive (grading = 3) reactions and positive reactions (grading greater than 3) increased. A positive Micro-Bumintest reaction was obtained with an albumin concentration of greater than 40 micrograms/ml. Presumptive positive reactions occur more than 50% of the time at protein concentrations greater than 14 mg/dl. The tablet test is more sensitive than the Clinitek 10/Multistix 10 SG strip system. These data show that the Micro-Bumintest reagent tablets are a sensitive and convenient screening test for detection of microalbuminuria.

Albuminuria↗

PubMedDate not supplied

The long-term effect of pancreatic islet allotransplantation on glomerular basement membrane thickening in experimental diabetes.

Pancreatic islet cells were intraportally allotransplanted into rats 2 weeks after the induction of diabetes mellitus by streptozotocin. The effect of successful transplantation on glomerular basement membrane thickening was examined 14 months later. Four groups of animals were available for study; rats with accepted pancreatic islet transplants, rats in whom graft rejection was induced, diabetic nontransplanted rats, and age-matched normal controls. Animals with accepted grafts showed no significant basement membrane thickening when compared with age-matched normal controls, while animals with rejected grafts and nontransplanted diabetic animals showed significant glomerular basement membrane thickening compared with the other groups but were not significantly different from each other. The ability of early intraportal pancreatic islet cell allotransplantation to prevent glomerular basement membrane thickening indicates that the glycemic control achieved by this approach is superior to glycemic control by traditional insulin therapy. The results of this study confirm that early pancreatic islet allotransplantation can prevent the development of glomerular basement membrane thickening in diabetic recipient rats.

Animals↗

PubMedDate not supplied

Endothelin-1 is not involved in hemoglobin associated vasoactivities.

This study tested the hypothesis: is hemoglobin (Hb) associated vasoconstriction mediated by endothelins (ET)? Two millimeter segments of the thoracic aorta with intact endothelium were obtained from Sprague-Dawley rats (200-350g) and suspended in oxygenated Krebs buffer (37C, pH 7.4). The vessels were equilibrated at 2g of imposed tension for 1 hour. After submaximal tone was induced with norepinephrine (50nM), the presence of functional endothelium was verified by an acetylcholine (33uM) dilation test. The vessel rings were then treated with either ET-1 (3nM) or human stroma-free Hb (SFH; 2.2uM) and vascular response characteristics observed. Subsequently, the vessel rings were treated with BQ-123 (15uM), an ET-1 receptor antagonist, to test whether the ET-1 pathway is involved in the Hb associated vasoconstriction. Both ET-1 and SFH elicited contractory responses in aortic rings; the maximal tension increases at the doses tested were 54.8 +/- 8.5% and 39.2 +/- 22.5%, respectively, over the pretreatment values. The contractory response characteristics were, however, distinct; ET-1 caused a slow (time to maximal response; TMR = 28.8 +/- 6.4 min, N = 6) but prolonged contraction (> 30 min) while SFH caused a faster contraction (TMR = 7.2 +/- 1.7 min, N = 6) with a shorter duration (< 30 min). The TMR of ET-1 treated rings were significantly longer than that of SFH (P < 0.0005, t-test). Treatment with BQ-123 caused an immediate reversal of the SFH induced contraction but had no significant effect on the SFH induced contraction. If the Hb associated vasoconstriction were mediated by ET-1, BQ-123 should have also reversed the contraction. These results suggest that ET-1 pathway is not involved in the Hb mediated vasoconstriction.

Animals↗