Multiple regression analysis of pharmacogenetic variability of carvedilol disposition in 54 healthy Japanese volunteers

The aim of this study was to evaluate the pharmacogenetic variability in the disposition of carvedilol in the Japanese population. Five or 10 mg of carvedilol was orally administered to 54 healthy Japanese subjects (22-44 years old), and blood samples were taken at 2 and 6 h after dosing. We determined the polymorphic alleles of CYP2D6, CYP2C9, CYP2C19, CYP3A5, UGT2B7, and MDR1 in each subject. The whole blood concentration of R- and S-carvedilol was measured by an HPLC method. The pharmacokinetic parameters in individual subjects were estimated by the Bayesian method using the nonlinear mixed effects model (NONMEM) program. We then examined the effect of the genetic polymorphisms on the variability in the pharmacokinetics of carvedilol using a multiple regression analysis. The oral clearance (CL/F) and also apparent volume of distribution (V/F) of both enantiomers were significantly lower in the subjects with the CYP2D6*10 allele than those with the CYP2D6*1/*1, *1/*2, or *2/*2 genotype, confirming our previous finding that the bioavailability (F) and systemic clearance (CL) of R- and S-carvedilol in the liver is significantly altered in Japanese with the CYP2D6*10 allele. On the other hand, CYP2C9*3, CYP2C19*2, CYP2C19*3, CYP3A5*3, UGT2B7*2, and MDR1 C3435T did not significantly affect the pharmacokinetics of carvedilol in Japanese subjects.     

Effectiveness of antiadhesion barriers in preventing adhesion after myomectomy in patients with uterine leiomyoma

BACKGROUND: Myomectomy often causes adhesion formation and decreases subsequent fertility. The purpose of the present study was to evaluate the effectiveness of several antiadhesion barrier materials in preventing adhesion after myomectomy. METHODS: We prospectively classified 63 women undergoing myomectomy alone into four groups according to the type of antiadhesion material used: Hyaluronic acid-carboxymethylcellulose film (Seprafilm) (n = 21, Group 1), Dextran 40 (10% Dextran 40 Low Injection) (n = 17, Group 2), factor 13 with fibrinogen (Beriplast) (n = 12, Group 3) and control (n = 13, Group 4). We performed early second-look laparoscopy after the seventh post-operative day in all patients and examined adhesion formation in the abdominal cavity. The incidence of adnexal adhesions was evaluated according to the American Fertility Association (AFS) adhesion score. RESULTS: The incidence of uterine adhesion was 14.3% in Group 1, 70.6% in Group 2, 75.0% in Group 3 and 76.9% in Group 4. Adhesion formation in Group 1 was significantly less than that in Group 2 (p = 0.0004), Group 3 (p = 0.0005) and Group 4 (p = 0.0003). The incidence of peritoneal adhesion was 14.3% in Group 1, 29.4% in Group 2, 41.6% in Group 3 and 69.2% in Group 4. Adhesion formation in Group 1 was significantly less than that in Group 4 (p = 0.001). AFS scores in Groups 1-4 were 0.38+/-1.02, 4.58 +/- 7.02, 0.83 +/- 1.99 and 8.53 +/- 8.79 (mean +/- S.D.), respectively. Group 1 had the lowest AFS score and the difference between Group 1 and Group 4 was significant (p < 0.0001). The AFS score in Group 3 was also significantly less than that of Group 4 (p = 0.0009). CONCLUSION: Seprafilm was highly effective and was superior to the other antiadhesion materials tested in preventing uterine adhesions after myomectomy.     

Transforming growth factor-beta1 induces LMO7 while enhancing the invasiveness of rat ascites hepatoma cells

We have previously shown that transforming growth factor-beta1 (TGF-beta1) markedly stimulates the invasive capacity of rat ascites hepatoma AH130 W1 cells in vitro and in vivo. A differential hybridization procedure was used to isolate genes that were specifically up-regulated in TGF-beta1 treated W1 cells. Among ten independent cDNA clones, we focused on LMO7 and a variant isoform, LMO7S, that was generated by alternative splicing. LMO7 had PDZ and LIM domains, while LMO7S had only PDZ domain. TGF-beta1 up-regulated expression levels of LMO7 and LMO7S. LMO7 expression was up-regulated in the highly metastatic clone MM1.     

Stereoselective metabolism of carvedilol by the beta-naphthoflavone-inducible enzyme in human intestinal epithelial Caco-2 cells

Treatment of Caco-2 cells with beta-naphthoflavone (beta-NF) and 1alpha,25-dihydroxyvitamin D(3) (VD(3)) induces UDP-glucuronosyltransferases (UGTs) and cytochrome P450 (CYP) 3A4, respectively. In the present study, we evaluated the metabolism of carvedilol in beta-NF- and VD(3)-treated Caco-2 cells. The metabolism of R-carvedilol was not significant in non-treated Caco-2 cells, whereas S-carvedilol was significantly metabolized in the cells. The metabolism of R- and S-carvedilol was significantly increased by the treatment of Caco-2 cells with 50 microM beta-NF for 3 d. In contrast, the treatment of Caco-2 cells with 250 nM VD(3) for 2 weeks did not induce a significant change in the metabolism of R- and S-carvedilol. The metabolism of carvedilol in beta-NF-treated Caco-2 cells was markedly inhibited by a substrate of UGTs, baicalein. In addition, the expression of UGT1A1, 1A6, and 1A9 mRNA was increased in beta-NF-treated Caco-2 cells as compared with non-treated cells. These findings indicated that carvedilol was metabolized stereoselectively by the beta-NF-inducible enzyme in Caco-2 cells. The UGT1A subfamily in intestinal epithelial cells may be partly responsible for first-pass (presystemic) metabolism of the drug.     

Endothelial progenitor thrombospondin-1 mediates diabetes-induced delay in reendothelialization following arterial injury

Delayed reendothelialization contributes to restenosis after angioplasty and stenting in diabetes. Prior data have shown that bone marrow (BM)-derived endothelial progenitor cells (EPCs) contribute to endothelial recovery after arterial injury. We investigated the hypothesis that the EPC contribution to reendothelialization may be impaired in diabetes, resulting in delayed reendothelialization. Reendothelialization was significantly reduced in diabetic mice compared with nondiabetic mice in a wire-induced carotid denudation model. The EPC contribution to neoendothelium was significantly reduced in Tie2/LacZ BM-transplanted diabetic versus nondiabetic mice. BM from diabetic and nondiabetic mice was transplanted into nondiabetic mice, revealing that reendothelialization was impaired in the recipients of diabetic BM. To examine the relative roles of denuded artery versus EPCs in diabetes, we injected diabetic and nondiabetic EPCs intravenously after arterial injury in diabetic and nondiabetic mice. Diabetic EPCs recruitment to the neoendothelium was significantly reduced, regardless of the diabetic status of the recipient mice. In vitro, diabetic EPCs exhibited decreased migration and adhesion activities. Vascular endothelial growth factor and endothelial NO synthase expressions were also significantly reduced in diabetic EPCs. Notably, thrombospondin-1 mRNA expression was significantly upregulated in diabetic EPCs, associating with the decreased EPC adhesion activity in vitro and in vivo. Reendothelialization is impaired by malfunctioning EPCs in diabetes. Diabetic EPCs have phenotypic differences involving thrombospondin-1 expression compared with nondiabetic EPCs, revealing potential novel mechanistic insights and therapeutic targets to improve reendothelialization and reduce restenosis in diabetes.     

Proposal of new uncertainty factor application to derive tolerable daily intake

We propose new uncertainty factors (UFs) and a new subdivision of default factors in chemical risk assessment using a probabilistic approach based on the latest applicable information. Rounded values of 150 for mice, 100 for hamsters and rats, and 40 for rabbits, monkeys and dogs for inter- and intra-species differences (UF_AH) were derived from the probabilistic combination of two log-normal distributions. Further calculation of additional UFs when chronic data (UF_S) or NOAEL (UF_L) are lacking was conducted using available log-normal distribution information. The alternative UF_S and UF_L values of 4 are considered to be appropriate for both cases where data are lacking. The default contributions of inter-species difference (UF_A) and intra-species difference (UF_H) to the UF_AH of 100 for hamsters and rats as an example are considered to be 25 and 4, respectively. The UF_A of 25 was subdivided into 25^0.6 (i.e., 7.0) for pharmacokinetics (PK) (UF_A,PK) and 25^0.4 (i.e., 3.6) for pharmacodynamics (PD) (UF_A,PD), and the UF_H of 4 was evenly subdivided into 4^0.5 (i.e., 2) (UF_H,PK and UF_H,PD), to account for chemical-specific difference data between humans and laboratory animals for PK and/or PD. These default UFs, which come from actual experimental data, may be more appropriate than previous default UFs to derive tolerable daily intake values.