Recent advances in preclinical in vitro approaches towards quantitative prediction of hepatic clearance and drug-drug interactions involving organic anion transporting polypeptide (OATP) 1B transporters

Hepatic uptake mediated by organic anion transporting polypeptide (OATP) 1B1 and 1B3 can serve as a major elimination pathway for various anionic drugs and as a site of drug-drug interactions (DDIs). This article provides an overview of the in vitro approaches used to predict human hepatic clearance (CL_h) and the risk of DDIs involving OATP1Bs. On the basis of the so-called extended clearance concept, in vitro–in vivo extrapolation methods using human hepatocytes as in vitro systems have been used to predict the CL_h involving OATP1B-mediated hepatic uptake. CL_h can be quantitatively predicted using human donor lots possessing adequate OATP1B activities. The contribution of OATP1Bs to hepatic uptake can be estimated by the relative activity factor, the relative expression factor, or selective inhibitor approaches, which offer generally consistent outcomes. In OATP1B1 inhibition assays, substantial substrate dependency was observed. The time-dependent inhibition of OATP1B1 was also noted and may be a mechanism underlying the in vitro–in vivo differences in the inhibition constant of cyclosporine A. Although it is still challenging to quantitatively predict CL_h and DDIs involving OATP1Bs from only preclinical data, understanding the utility and limitation of the current in vitro methods will pave the way for better prediction.     

Investigation of non-linear Mate1-mediated efflux of trimethoprim in the mouse kidney as the mechanism underlying drug-drug interactions between trimethoprim and organic cations in the kidney

The purpose of this study was to elucidate the involvement of Mate1 in the tubular secretion of trimethoprim and saturation of Mate1-mediated efflux to address the mechanisms underlying the pharmacokinetic drug interactions with trimethoprim. Trimethoprim is a more potent inhibitor of MATE2-K than MATE1 with K_i values (μM) of 0.030–0.28 and 2.4–5.9, respectively. Trimethoprim is a substrate of human MATE1 and MATE2-K with K_m values of 2.3 ± 0.9 and 0.018 ± 0.004 μM, and mouse Mate1, but not human OCT2, mouse Oct1 and Oct2. Pyrimethamine significantly reduced the renal clearance (CL_R) of trimethoprim (mL/min/kg) from 40.0 ± 5.1 to 20.1 ± 3.7 (p < 0.05). Trimethoprim was given to mice at three infusion rates (150, 500, and 1500 nmol/min/kg). Together with an increase in the plasma concentrations of trimethoprim, the CL_R (mL/min/kg) of trimethoprim decreased to 25.9 ± 3.2, 13.5 ± 5.7, and 8.92 ± 1.50 at the respective rates. Trimethoprim decreased the CL_R of rhodamine 123 in an infusion rate-dependent manner: 11.5 ± 1.3 (control), 5.17 ± 1.55, 1.31 ± 0.50, and 0.532 ± 0.180. These results suggest that Mate1 mediates the tubular secretion of trimethoprim, and at therapeutic doses, MATEs-mediated efflux can be saturated, and thereby, cause drug interactions with other MATE substrates.     

On the Edge: a drama‐based mental health education programme on early psychosis for schools

Aims: On the Edge is a mental health education programme designed to support early intervention by increasing knowledge and understanding of early psychosis, reducing the stigma associated with mental health issues and improving awareness of avenues of help. The target audience was young people aged 14–22 years in schools and colleges. Methods: An interactive drama programme was developed through collaborative working across psychiatry, applied drama and those with direct experience of psychosis. A national tour engaged 2500 students in 71 performances that took place in 51 schools and colleges. The programme was evaluated against its aims with data collected both during and after the tour. Results: Quantitative and qualitative evaluation found significant gains with respect to all three aims. Thirty‐one schools developed supportive links with local mental health services. Conclusions: This programme shows the value and effectiveness of delivering health education on early psychosis through the medium of applied drama, and offers a model for a programme that can be incorporated into early intervention services. Lessons learned through delivering this programme are a valuable contribution towards future developments of mental health education programmes for schools.     

The First‐Episode Psychosis Outcome Study: premorbid and baseline characteristics of an epidemiological cohort of 661 first‐episode psychosis patients

Aims: Studies conducted in first‐episode psychosis (FEP) samples avoid many biases. However, very few studies are based on epidemiological cohorts treated in specialized FEP services. The aim of this file audit study was to examine premorbid and baseline characteristics of a large epidemiological sample of FEP. Methods: File audit study of all patients admitted to the Early Psychosis Prevention and Intervention Centre between 1998 and 2000 using a specialized questionnaire. Results: There were 661 patient files included in the study. Premorbid evaluation revealed high rates of substance use disorder (74.1%), history of psychiatric disorder (47.5%), past traumatic events (82.7%) suicide attempts (14.3%) and family history of psychiatric illness (55.6%). Baseline characteristics revealed high intensity of illness (mean CGI 5.5), high prevalence of lack of insight (62%) and high rate of comorbidity (70%). Conclusion: High rates of traumatic events or episodes of mental illness before treatment for FEP must be considered when designing treatment approaches because a too narrow focus on positive psychotic symptoms will inevitably lead to incomplete treatment. Additionally, early intervention programmes need sufficient range of resources to address the multiple challenges presented by FEP patients such as high severity of illness, comorbidities and functional impairment. Finally, observation of an important degree of functional impairment despite short duration of untreated psychosis suggests that while early detection of FEP is a necessary step in early intervention, it may not be sufficient to improve functional recovery in psychosis and that efforts aimed at identifying people during the prodromal phase of psychotic disorders should be pursued.     

有机锗对环磷酸胺抗移植肝癌作用的影响

用有机锗（Ge－132）试验治疗荷移植肝癌小鼠。结果：De－132高剂量（12．5mg/次）治疗组的抑癌率为用31．0％，移植肝癌白细胞（WBC）浸润（＋＋＋）占72．7％、血清超氧化物歧化酶（SOD）活性为121Nu／ml，而生理盐水对照治疗组相应的后两项指标分别为用36．4％及81Nu／ml，两组比较有显著性差异（P＜0．05）；环磷酰胺（CTX）治疗组的抑癌率为37.0％，癌体WBC浸润（＋＋＋）为27.3％，血清SOD活性为102Nu／ml；ge-132高剂量与CTX2联合治疗组的抑癌率为45．0％，癌体WBC浸润（＋＋＋）为54．5％，血清SOD活性为142Nu/ml，两组比较，后二项指标有显著性差异（P＜0．05）。由此提示Ge-132高剂量能明显增强荷移植肝癌小鼠的细胞免疫及血清SOD活性，并有一定的抗移植肝癌作用。     

Occupational hydrocarbon exposure and chronic nephropathy

This review aims at discussing the questions raised by the hydrocarbon-related chronic nephropathy and its possible consequence, the hydrocarbon-related chronic renal failure. It has been attempted to adopt the point of view of the clinician. Therefore, the most important part of the review is devoted to a presentation and an analysis of the available data on humans. The main features of the available studies on human subjects are presented, their conclusions discussed in the light of the possible methodological flaws, and practical conclusions drawn. After a discussion of the main difficulties encountered for selecting the suitable exposure indicator, the studies are discussed in order of decreasing quality of the study design (cohort, case-control, cross-sectional studies, and the case reports). It is concluded that a great deal of controversies about chronic hydrocarbon-related nephropathy is explained by differences in the study design and that hydrocarbon-induced nephropathy is probably more than a mere hypothesis, although a causal relationship has not yet been proven. Finally, some practical consequences for dealing with a hydrocarbon-exposed patient diagnosed with a kidney disease and the need for further research are discussed.     

饮水有机浓集物致突变活性影响因素的研究

本文探讨饮水有机物浓集流速及加氯量对致突变活性的影响。试验表明，饮水有机物浓集流速控制在每分钟２倍树脂柱床体积时，可获得最佳致突变效果。当加氯量≥２０ｍｇ／Ｌ时，对ＴＡ９８±Ｓ９和ＴＡ１００—Ｓ９菌株有致突变活性，≤２ｍｇ／Ｌ时对ＴＡ９８±Ｓ９和ＴＡ１００±Ｓ９菌株无致突变活性。为最大限度减少致突变效应，在净水过程中保证流行病学安全前提下，减少加氯量和加氯次数是十分必要的。