Triterpenoid saponins from Platycodon grandiflurum.

A new bisdesmosidic saponin, named deapio-platycoside E (1), together with two known triterpenoid saponins (2, 3) were isolated from the roots of Platycodon grandiflorum (Jacq.) A. D.C. Their structures were elucidated by spectroscopic and chemical methods.

Racial differences in survival of patients on dialysis.

BACKGROUND: Recent studies have documented racial differences in the crude mortality rates of patients on dialysis. However, proper interpretation of these findings requires adjustment for potential confounders and comorbid risk factors between the racial groups. METHODS: We examined the clinical data on 3752 Caucasian patients, 451 Southeast Asian patients, 322 South Asian patients, and 319 black patients who were treated with hemodialysis or peritoneal dialysis under a Universal Health Care system in Toronto and prospectively followed between 1981 and 1995. In all patients, a number of comorbid risk factors for survival was assessed at the start of dialysis and was reassessed with their outcome status (that is, continued dialysis, transplantation, death, or loss to follow-up) at least every six months. Cox proportional hazards analysis was used to fit multivariate models predicting patient survival. Pairwise comparisons of the relative hazards of death between the racial groups were performed after stratifying for cardiovascular disease, diabetes mellitus, and hypertension at the start of dialysis, and were adjusted for differences in other comorbid risk factors. RESULTS: The risk of death in Caucasian patients was significantly increased when compared with Southeast Asian patients, South Asian patients, and black patients [multivariate relative hazards (95% CI): 1.63 (1.36 to 1.97), 1.36 (1.07 to 1.73), 1.34 (1.07 to 1.67), respectively]. Additionally, we detected an interaction between race and cigarette smoking (P < 0. 004), suggesting that in the dialysis patients who smoked, whites had a higher mortality risk compared with non-whites. CONCLUSIONS: Differences in patient survival on dialysis exist between racial groups. However, the genetic and environmental determinants that underlie these differences are presently unknown.

Angiotensin converting enzyme gene polymorphism and renal hemodynamic function in early diabetes.

An insertion/deletion (I/D) of the human angiotensin converting enzyme (ACE) gene is a major determinant of circulating ACE levels. Recent studies suggest that the ACE I/D polymorphism may influence the risk of developing nephropathy in patients with insulin dependent diabetes mellitus (IDDM), although the mechanism responsible for the effect is unknown. Since an early increase in glomerular filtration rate (GFR) may also be a risk factor for the development of diabetic nephropathy, we sought to determine if the ACE I/D polymorphism influenced renal hemodynamic function in patients with IDDM. Genomic DNA was obtained from 39 normotensive male and female patients with uncomplicated IDDM (mean duration 3.4 years; range 1 to 6 years), and from 20 non diabetic control subjects. The ACE I/D polymorphism was determined using the polymerase chain reaction. Subjects were divided into three groups based on their ACE genotype. Values for GFR, renal plasma flow (ERPF), filtration fraction, and renal vascular resistance were determined in both groups using classic inulin and paraaminohippurate clearance techniques. Blood glucose was maintained between 4 to 6 mmol/liter in the patients with IDDM using a modified euglycemic clamp technique. Mean values for GFR were significantly greater in patients homozygous for the I allele (143 +/- 7 ml/min/1.73 m2) compared to patients homozygous for the D allele (121 +/- 3 ml/min/1.73 m2, P < 0.01), while the mean GFR values for the heterozygous patients were intermediate. ERPF was also significantly greater in patients homozygous for the I allele (850 +/- 103 ml/min/1.73 m2) compared to patients homozygous for the D allele (672 +/- 31 ml/min/1.73 m2, P < 0.04), while there were no differences in the values for mean arterial pressure, glycosylated hemoglobin, or albumin excretion rates amongst the groups. There was no dominant effect of the ACE gene I/D polymorphism in the control group. These results suggest that: (1) the ACE gene I/D polymorphism influences glomerular filtration and renal plasma flow rates in patients with early uncomplicated IDDM; and (2) differences in renal hemodynamic function do not appear to explain the protection against the development of diabetic nephropathy offered by the I allele.

[Structure determination of korepimedoside A and korepimedoside B from Epimedium koreanum Nakai].

Two new flavonol glycosides were isolated from the aerial parts of Epimedium koreanum Nakai. On the basis of spectroscopic and chemical evidence, they were elucidated as anhydroicaritin 3-O-beta-D-(6-acetyl) glucopyranosyl (1-->3)-alpha-L-(4-acetyl) rhamnopyranoside and anhydroicaritin 3-O-beta-D-(2, 6-diacetyl) glucopyranosyl (1-->3)-alpha-L-(4-acetyl) rhamnopyranoside-7-O-beta-D-glucopyranoside, which were named korepimedoside A and korepimedoside B respectively.

A comparison of rabbit antithymocyte serum and OKT3 as prophylaxis against renal allograft rejection.

A total 166 first cadaveric renal allograft recipients were randomly assigned to receive either rabbit antithymocyte serum (RATS) (n = 83) or OKT3 (n = 83) for 10 to 14 days after transplant as prophylaxis against rejection. Both groups were similar with respect to age, sex, donor age, diabetes, time on dialysis, panel-reactive antibody, HLA matching, and transfusion before transplantation. All patients were followed for 1 year after transplantation. A comparison of the rejection rates between the 2 groups of patients showed that patients receiving OKT3 had a rate of first rejection 1.87 times higher than those receiving RATS (95% confidence interval 1.18-2.8, P = 0.007). Twenty-five steroid-resistant rejections occurred in OKT3-treated patients as compared with 12 in the RATS-treated group (P < 0.05). There was no significant difference in early or late renal function between the 2 groups of patients. Actuarial 1-year graft survival for the RATS group was 78% and for the OKT3 group, 80.7% (P = NS). Actuarial 1-year patient survival was similar: 89.5% in the RATS group and 94.6% in the OKT3 group (P = NS). Total hospitalization time was 29.8 +/- 19.9 days for RATS vs. 39.5 +/- 22.1 days for those treated with OKT3 (P < 0.006). A number of infections were observed but there were no significant differences between the groups. We conclude that RATS provides better prophylaxis than OKT3 in first cadaveric renal transplants because it is associated with fewer rejection episodes, less hospitalization, and no additional morbidity or mortality.

[A new minor saponin from the leaves of Panax ginseng C. A. Meyer].

Two minor compounds isolated from the leaves of Panax ginseng C. A. Meyer were characterized as 20(R)-protopanaxadiol (I) and 3 beta, 6 alpha, 12 beta-trihydroxydammar-20 (22), 24-diene-6-O-alpha-L-rhamnosyl-(1----2)-beta-D-glucopyranoside (II) on the basis of spectral analysis and chemical evidences. I was isolated for the first time from the leaves; II was shown to be a new saponin and was named as ginsenoside-Rg4.