The effect of lithium chloride on morphine-induced tolerance and dependence in isolated guinea pig ileum

The chronic use of opioids is often accompanied by the development of tolerance and/or dependence upon these agents due to the adaptive changes in the response of the subject to the agent. On cellular level, these phases of altered responsiveness have been shown to be the sequelae of a combination of multiple independent components acting in concert. Changes in the number, affinity, or membrane trafficking of opioids receptors, the coupling of receptors to G-proteins or in associated second messenger systems have been implicated in underlying the aforementioned phenomena. Several observations have been shown that lithium is able to contradict the expected response in animals pre-treated with morphine. These facts clearly manifest the involvement of lithium in at least one of the diverse pathways that lead to morphine dependence and/or tolerance. The aim of the present study was to investigate the effect of lithium on acute morphine-induced tolerance and dependence in an in vitro model of isolated guinea pig ileum which has been extensively used for the assessment of these effects of opioids. Morphine inhibited electrically stimulated twitch of ileum in a concentration-dependent manner (pD(2)=7.27+/-0.16). Tolerance to this effect was induced by the incubation of ileum with 2xIC(50) of morphine for 2 h that induced a degree of tolerance of 14.7. The co-incubation of ileum with morphine along lithium chloride (1 mM) reduced the degree of tolerance significantly (P<0.001) and restored the sensitivity of ileum to the morphine inhibitory effect. Lithium chloride can also reduce the expression of tolerance to morphine significantly (P<0.01). Dependence was induced by incubation with 4xIC(50) of morphine for 2 h and was assessed based on naloxone-induced contractions (10(-5 )M). Lithium chloride (1 mM) can attenuate the development but not the expression of dependence to morphine as shown by the significant decrease in naloxone-induced contractions (P<0.05). These results suggest that lithium chloride can reduce the development and expression of acute tolerance to and development of dependence on morphine in the myenteric plexus of guinea pig ileum.     

Apparent clearance of sirolimus in heart transplant recipients: impact of primary diagnosis and serum lipids

The study was aimed to identify factors affecting sirolimus apparent clearance (CL/F) in de novo heart transplant recipients using a population pharmacokinetic approach. A total of 31 patients (7 female and 24 male) originally included in a formal clinical trial, contributed 524 sirolimus blood concentrations with the time after dose ranging from 11.08 to 31.83 hours. Sirolimus concentrations were measured using liquid chromatography-tandem mass spectrometry and data analysis was carried out using NONMEM (Globomax LLC, Hanover, MD) software. Factors screened included age, weight, gender, primary diagnosis, biochemical and hematological indices, cyclosporine dose, days post-transplant and potential interacting medications. The predictive performance of the final model was evaluated using a data-splitting method. Sirolimus apparent clearance (CL/F) was decreased by 20.8% for every 100 mg increase in cyclosporine daily dose and was 62.1% lower in patients with primary diagnosis of ischemic heart disease (IHD). Sirolimus apparent clearance was 37.8% lower when triglyceride was greater than 2 mmol/L. Based on the final model, the average values for sirolimus CL/F and apparent volume of distribution were 7.09 and 1350 L/h, respectively. Inter-subject variability in CL/F was 27.5% and residual random error was 24.1%. This study identified cyclosporine dose, hypertriglyceridemia and primary diagnosis of IHD as the most important factors affecting sirolimus CL/F. This information may assist in dose individualization of sirolimus in heart transplant recipients.     

High-performance liquid chromatography method for the determination of mycophenolic acid and its acyl and phenol glucuronide metabolites in human plasma

Measuring the concentration of the pharmacologically active metabolite of mycophenolic acid (MPA), acyl-MPAG (AcMPAG), in addition to the pharmacologically inactive phenol glucuronide metabolite (MPAG) may prove useful in the therapeutic drug monitoring of MPA. A simple high-performance liquid chromatography method with ultraviolet detection (HPLC-UV) was established for simultaneous determination of MPA, AcMPAG, and MPAG in human plasma. The method utilizes 2 internal standards (IS), phenolphthalein glucuronic acid (PGA) for MPAG and a carboxy butoxy derivative of MPA (MPAC) for AcMPAG and MPA. The method consists of solid-phase extraction of the analytes followed by analysis over a Zorbax Rx C8 column (150 x 4.6 mm, 5 mum) at 254 nm. The analytes were separated with a gradient mixture of methanol and 0.1% phosphoric acid over a run time of 14 minutes at a flow rate of 1 mL/min. The assay was linear in the concentration range from 0.2 to 50 mg/L for MPA, 0.5 to 25 mg/L for AcMPAG, and 2 to 500 mg/L for MPAG. The mean +/- SD interday accuracy and %CV for MPA were 100.3 +/- 5.7 and 5.7%, for AcMPAG, 102.6 +/- 5.7 and 5.6%, and for MPAG 100.5 +/- 5.3 and 5.3%, respectively. The average +/- SD of MPA, MPAG, and AcMPAG maximum concentrations (Cmax) in 23 kidney transplant recipients on 500 or 1000 mg twice daily mycophenolate mofetil were 11.77 +/- 9.43, 88.15 +/- 46.4, and 3.01 +/- 1.73 mg/L, respectively, and the predose trough (Cmin morning) concentrations were 2.24 +/- 3.11, 55.44 +/- 29.55, and 1.42 +/- 0.74 mg/L, respectively. The method described is robust, sensitive, reproducible, and will be useful in therapeutic drug monitoring or pharmacokinetic studies of MPA.     

A single nucleotide polymorphism chip-based method for combined genetic and epigenetic profiling: validation in decitabine therapy and tumor/normal comparisons

Progress on several unresolved issues in cancer epigenetics will benefit from rapid and standardized methods for profiling DNA methylation genome-wide. In the area of epigenetic therapy, the demethylating drug decitabine (5-aza-2'-deoxycytidine) is increasingly used to treat acute myelogenous leukemia and myelodysplastic syndrome, but the mechanisms of its anticancer activity have remained unclear. Given the clinical efficacy of decitabine and the uncertainties about its mode of action, it will be useful to optimize methods for following DNA methylation as a biochemical response in individual patients. Here, we describe a single nucleotide polymorphism (SNP) chip-based method (MSNP) for profiling DNA methylation. Using this procedure, the extent of demethylation in bone marrow aspirates from patients with leukemia receiving decitabine can be assessed genome-wide using commercially available (Affymetrix) SNP chips. We validated the accuracy of MSNP by comparing the results with combined bisulfite restriction analysis and by sequencing cloned PCR products from bisulfite-converted DNA. We further validated MSNP in a Wilms' tumor/normal kidney comparison, comparing the results with methylation-sensitive Southern blotting. MSNP simultaneously detects aberrations in DNA copy number and loss of heterozygosity, making it a generally useful approach for combined genetic and epigenetic profiling in tissue samples from cancer patients.     

Lymphatic and vascular origin of Kaposi's sarcoma spindle cells during tumor development

The histogenesis of Kaposi's sarcoma (KS) tumor spindle cells (SC) remains controversial but several immunohistochemical studies favor a lymphatic origin. Twenty KS surgical biopsies were analyzed for the coexpression of LANA, CD34, LYVE-1, D2-40, VEGFR-2, VEGFR3 by using double or triple immunostaining. Most of the SC in both early and late KS expressed the lymphatic markers LYVE-1, D2-40 and VEGFR-3 and the blood vascular endothelial/endothelial precursor cell markers CD34 and endothelial stem cell marker VEGFR-2. All the LANA+ SC in early and late KS were LYVE-1+, but only 75% of these LANA+ cells were CD34(+). The CD34(+)/LANA+ cells increased from early- (68.8%) to late-stage KS (82.2%). However, approximately 18% of the LANA+ SC in early KS were CD34(-) but were LYVE-1+, suggesting that resident lymphatic endothelial cells (LEC) are targeted for primary infection by human herpesvirus-8. This LANA+/LYVE-1+/CD34(-) (resident LEC) cell population clearly decreased during the development of KS from early (18.7%) to late KS (2.9%). Thus, in late stages of KS, most SC were LANA+/CD34(+)/LYVE-1+. However, in both early- and late-stage KS, approximately 18% of the SC were CD34(+)/LANA-/LYVE-1 -- and could represent newly recruited endothelial precursor cells, which become infected in the lesion and eventually undergo a phenotype switch expressing LEC markers. Our study apparently indicates that KS represents a unique variant of tumor growth with continues recruitment of tumor precursor cells as well as proliferation and decreased apoptosis of SC.     

Sustainability in local public health nutrition programmes: beyond nutrition education, towards community collaboration

The present paper presents the approach, results and outcome of an innovative piece of action research amongst professionals (health and non-health) and the public (women and young people from low-income families in one of the deprived areas of Birmingham, UK). A cooperative inquiry approach was used and data were collected on concerns about health of professionals (n 15) and the public (n 19), as well as dietary practices, smoking pattern and access to healthy foods amongst the public (n 49). The methods of data collection were: desk research; observation; semi-structured individual and focus-group interviews; structured individual interviews. The findings highlight diverse views and expectations about health amongst the public and the professionals, and suggest the existence of tensions between the partnership and the ownership of inter-agency collaboration. It argues the importance of having a shared vision amongst health and non-health professionals regarding health strategy and the way forward for working together to promote the public's health. It recommends that by using the tenet of action research, and adapting a cooperative inquiry approach, members of a partnership project could learn through reflection on action and achieve personal development and social action.     

Physical trauma and substance abuse: a comparative study on substance abuse in patients with physical trauma versus general population

AIM: To evaluate the prevalence of substance abuse in a sample of patients with acute physical trauma in comparison with the general population. METHOD: Prospective study using structured interview based on DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th ed) criteria for substance dependence and abuse. SETTING: Hospitals at Shiraz University of Medical Sciences, and the general population in Shiraz. PARTICIPANTS: 1,324 subjects selected randomly (324 subjects from patients with acute physical trauma, and 1,000 subjects from general population). RESULTS: The mean age was 37 (SD=15.5, age range=15-83 yr.) In the general population, the mean age was 36.5 (SD=14.29, age range=15-83). Substance use was much more prevalent among patients with acute physical trauma than in the general population. It should be mentioned that drug use precedes the trauma in the patient population and may contribute to the occurrence of trauma or disease. CONCLUSIONS: Substance use was significantly more prevalent in males than in females. Cultural attitudes toward usage of substances were found to affect the type and amount of the used substance. These findings should be considered when planning preventive and therapeutic programs.     

Shock wave induced cytoskeletal and morphological deformations in a human renal carcinoma cell line

Effects of shock waves on the morphology and cytoskeleton of a human renal carcinoma cell line (ACHN) were investigated in vitro. ACHN monolayer cultured on a cover slide glass was treated with 10 shots of focused underwater shock waves, with 16 MPa peak pressure at the focal area of a piezoceramic shock wave generator. After exposure to the shock wave, based on the severity of morphological deformations of the treated cells, the monolayer was divided into three morphological areas; focal, marginal and intact. Morphological deformations were found to be associated with disorganization of the intracellular cytoskeletal filaments. Deformation of the cytoskeletal proteins in the treated cells were separately studied with respect to the location of the cells within the three morphological areas. Among three major cytoskeletal proteins, actin and tubulin, but not vimentin, were affected by the shock waves. The deformed cells reorganized their cytoskeletal network within 3 h with a pattern similar to the control, indicating the transient characteristic of the shock wave induced cytoskeletal damage in the surviving cells. The remaining cell fragments on the slide glass, which contained short actin filaments, indicated the important role of shear stress in damaging the cytoskeletal fibers by shock waves.