Metabolic activation of methyl-hydroxylated derivatives of 7,12- dimethylbenz[a]anthracene by human liver dehydroepiandrosterone-steroid sulfotransferase

Methyl-hydroxylated metabolites of the potent carcinogen, 7,12- dimethylbenz[a]anthracene (DMBA), namely, 7-hydroxymethyl-12- methylbenz[a]anthracene (7-OH-DMBA), 7-methyl-12- hydroxymethylbenz[a]anthracene (12-OH-DMBA) and 7,12- dihydroxymethylbenz[a]anthracene (7,12-diOH-DMBA), were examined as substrates for sulfotransferase bioactivation in different human tissue cytosols. Hepatic cytosols, which were able to catalyze the 3'- phosphoadenosine 5'-phosphosulfate (PAPS)-dependent DNA binding of 7-OH- DMBA, 12-OH-DMBA and 7,12-diOH-DMBA, were highly sensitive to inhibition by dehydroepiandrosterone (DHEA), a specific substrate for human DHEA-steroid sulfotransferase (IC50 = 5 microM). By comparison, 2,6-dichloro-4-nitrophenol, a potent inhibitor of the thermostable (TS)- phenol and estrogen sulfotransferases, did not have an appreciable inhibitory effect. Neither p-nitrophenol, a high affinity substrate for human TS-phenol and estrogen sulfotransferases, nor dopamine, a specific substrate for the thermolabile (TL)-phenol sulfotransferase, significantly inhibited the DNA binding of 12-OH-DMBA catalyzed by hepatic cytosols. Inter-subject variation (n = 12) of the PAPS- dependent DNA binding of 12-OH- and 7,12-diOH-DMBAs also correlated well with DHEA-sulfotransferase activity (r = 0.90; P < 0.00001 and r = 0.92; P < 0.00001, respectively). This sulfation-dependent metabolic activation was not detected in cytosols from human colon, pancreas, larynx or mammary gland. Both TS- and TL-phenol sulfotransferases were active in human liver and colon but only liver contained DHEA- sulfotransferase activity. These results indicate that the sulfotransferase-mediated activation of the methyl-hydroxylated DMBAs is predominantly catalyzed by DHEA-steroid sulfotransferase in human liver and that TS- and TL-phenol sulfotransferases and estrogen sulfotransferase are not involved in the catalysis.      

高效毛细管电泳/前沿分析及其在手性药性药物-蛋白结合研究中的应用

目的：综述了高效毛细管电泳／前沿分析（HPCE／FA）方法的原理、特点、及其在手性药物－蛋白结合研究中的应用。方法：采用HPCE／FA方法。结果：不同的手性药物对映体与蛋白结合可能存在判别,同一药物对映体之间与不同蛋白结合率可能存在差别,HPCE／FA仅需极少量样品即可同时测定手性药物各对映体在蛋白结合中的游离浓度。结论：HPCE／FA是一种高效、分析迅速、样本用量极少的研究蛋白结合方法,特别是对于手性药物与昂贵不易获得的蛋白结合研究。     

1，1－二烷基－4－（3－溴丙酰基）－哌嗪溴化物的合成及生物活性研究

设计合成了七种新的１，１－二烷基－４－（３－溴丙酰基）哌嗪季铵盐溴化物，通过ＩＲ，￣１ＨＮＭＲ和元素分析证实其结构。初步生物活性试验结果表明，Ⅵａ，Ⅵｃ和Ⅵｅ～ｇ有明显的镇痛活性，Ⅵｅ～ｇ还有较好的抗氧化ＳＯＤ活性，但未发现有抗肿瘤作用。     

Persistently normal alanine aminotransferase levels in HIV/HCV-coinfected patients: the role of steatosis

Objective

The frequency and significance of, and liver biopsy findings associated with, a persistently normal alanine aminotransferase (ALT) level in HIV/hepatitis C virus (HCV)‐coinfected patients are poorly characterized. We analysed factors associated with persistently normal ALT levels, defined as at least three consecutive normal ALT values over a 6‐month period, in a group of 381 HIV/HCV‐coinfected patients.

Methods

Patients were categorized into two groups according to ALT values: group 1, patients with persistently normal ALT levels; and group 2, patients with elevated ALT values. Possible interactions with host factors, HIV and HCV viral factors, antiretroviral treatment and histological features were examined.

Results

Thirty‐six patients (9.4%) had persistently normal ALT levels. None of the 36 patients had cirrhosis. Seven patients (19.4%) had a METAVIR fibrosis score of F3. In multivariate analysis, a lower mean METAVIR inflammation score [odds ratio (OR) 0.50, 95% confidence interval (CI) 0.28–0.89; P=0.017], the absence of steatosis (OR 0.43, 95% CI 0.20–0.90; P=0.026) and HCV genotype 4 infection (OR 2.81, 95% CI 1.15–6.68; P=0.023) were associated with persistently normal ALT levels.

Conclusion

The slower progression of chronic hepatitis in patients with persistently normal ALT levels could be related, in part, to a lower frequency of steatosis

     

Outcomes of extended versus limited indications for patients undergoing a liver resection for colorectal cancer liver metastases

Background

Currently, resection criteria for colorectal cancer liver metastases (CRCLM) are only limited by remnant liver function. Morbidity and survival after a partial hepatectomy with limited or extended indication criteria were compared.

Methods/Design

Between 1991 and 2010, patients undergoing a liver resection for CRCLM with limited (n = 169) or extended indication criteria (n = 129) were retrospectively identified in a prospectively collected single-centre database. Limited indication criteria were defined as less than three unilateral, not centrally located liver metastases in the absence of extra hepatic metastases. The extended criteria were only limited by predicted remnant liver volume and patients fitness. Data on co-morbidity, resection margin, short- and long-term morbidity, disease-free (DFS) and overall survival were compared.

Results

Patients with limited indications had less major complications (19.5% vs. 33.1%, P < 0.01), longer overall survival of 68.8 months [confidence interval (CI) 46.5–91.1] vs. 41.4 months (CI 33.4–49.0, P ≤ 0.001) and longer median DFS of 22.0 months [confidence interval (CI) 15.8–28.2] vs 10.2 months (CI 8.4–11.9, P < 0.001) compared with the extended indication group. Cure rates, defined as 10-year DFS, were 35.5% and 15.8%, respectively. Fewer patients in the extended indication group underwent an R0 resection (92.9% vs. 77.5%, P < 0.001). Only 17% of all R1 resected patients had recurrences at the transection plane.

Conclusion

A partial hepatectomy for CRCLM with extended indications seems justified but is associated with higher complication rates, earlier recurrence and lower overall survival compared with limited indications. However, the median 5-year survival was substantial and a cure was achieved in 15.8% of patients.     

Mechanical properties of prosthetic limbs: adapting to the patient.

Lower-limb amputees have identified comfort and mobility as the two most important characteristics of a prosthesis. While these in turn depend on a multitude of factors, they are strongly influenced by the biomechanical performance of the prosthesis and the loading it imparts to the residual limb. Recent years have seen improvements in several prosthetic components that are designed to improve patient comfort and mobility. In this paper, we discuss two of these: VSAP and prosthetic foot-ankle systems; specifically, their mechanical properties and impact on amputee gait are presented.     

Single-strand conformation polymorphism analysis is a rapid and effective method for the identification of mutations and polymorphisms in the gene for glycoprotein IIIa

Glanzmann thrombasthenia (GT) is the most common inherited disorder of platelets. Most of the molecular defects previously identified in GT have been caused by point (or other small) mutations in the genes for glycoprotein (GP) IIb or GPIIIa. We have used single-strand conformation polymorphism (SSCP) analysis to rapidly identify single- base changes in the GPIIIa gene. Using genomic DNA from normal individuals and patients with GT, each GPIIIa exon and a short stretch of flanking intronic sequence was amplified, heat-denatured, and separated in nondenaturing acrylamide gels. Only those fragments with an abnormal migration pattern were isolated and the nucleotide sequence determined. Using SSCP, we detected the polymorphism in the HPA-1 (P1A) system and all three known silent polymorphisms in the GPIIIa gene. Screening 14 GPIIIa exons from 5 patients with GT, one mutant allele was identified. The nucleotide sequence of the abnormal 240-bp SSCP fragment was determined and a G-->A substitution in the splice donor site of exon iv was identified. Analysis of platelet RNA resulting from this mutation showed two mRNA species: one contained a deletion of exon iv, whereas the other had a 27-bp addition to exon iv due to the use of a cryptic splice site in the downstream intron. Single-base substitutions are the most common mutation in GT and often result in abnormal mRNA splicing. SSCP is a rapid and sensitive technique for identifying mutations or polymorphisms in the GPIIIa gene.     

Budd‐Chiari syndrome in Sweden: epidemiology,clinical characteristics and survival – an 18‐year experience

Background: The exact incidence and prevalence of Budd‐Chiari syndrome (BCS) is unknown in the general population. Published reports differ in terms of the clinical characteristics, effects of therapy and survival. Aims: To investigate the epidemiology, clinical presentation and survival in patients with BCS. Methods: Retrospective multicentre study in Sweden reviewing the medical records of all patients with BCS 1986–2003, identified from the computerised diagnosis database of 11 hospitals, including all university hospitals and liver transplantation centres. Results: Forty‐three patients with BCS were identified, of whom nine (21%) had concomitant portal vein thrombosis. The mean age‐standardised incidence and prevalence rates in 1990–2001 were calculated to be 0.8 per million per year and 1.4 per million inhabitants respectively. Myeloproliferative disorders (38%), thrombophilic factors (31%) and oral contraceptives (30%) were common aetiological factors. Two or more risk factors were present in 44%. In 23%, no risk factor was evident. The median follow‐up time was 2.7 years. Seventy‐two percent were on anticoagulant therapy during follow‐up. Transjugular intrahepatic portosystemic shunting, surgical shunting procedures and liver transplantation were performed in 4, 6 and 18 patients respectively. Nineteen patients died. The overall transplantation‐free survival at 1, 5 and 10 years was 47, 28 and 17% respectively. Conclusions: Budd‐Chiari syndrome is a rare disorder; the mean age‐standardised incidence and prevalence rates in Sweden in 1990–2001 were calculated to be 0.8 per million per year and 1.4 per million inhabitants respectively. The presence of a myeloproliferative disorder was a common aetiological factor in our cohort and about half of the patients had a multifactorial aetiology. The transplantation‐free survival was poor.