PTP-MEG2 regulates quantal size and fusion pore opening through two distinct structural bases and substrates.

Tyrosine phosphorylation of secretion machinery proteins is a crucial regulatory mechanism for exocytosis. However, the participation of protein tyrosine phosphatases (PTPs) in different exocytosis stages has not been defined. Here we demonstrate that PTP-MEG2 controls multiple steps of catecholamine secretion.

Muscarinic inhibition of nicotinic transmission in rat sympathetic neurons and adrenal chromaffin cells.

Little is known about the interactions between nicotinic and muscarinic acetylcholine receptors (nAChRs and mAChRs). Here we report that methacholine (MCh), a selective agonist of mAChRs, inhibited up to 80% of nicotine-induced nAChR currents in sympathetic superior cervical ganglion neurons and adrenal chromaffin cells. The muscarine-induced inhibition (MiI) substantially reduced ACh-induced membrane currents through nAChRs and quantal neurotransmitter release.

RNAi-based knockdown of multidrug resistance-associated protein 1 is sufficient to reverse multidrug resistance of human lung cells.

Up-regulation of multidrug resistance-associated protein 1 (MRP1) is regarded as one of the main causes for multidrug resistance (MDR) of tumor cells, leading to failure of chemotherapy-based treatment for a multitude of cancers. However, whether silencing the overexpressed MRP1 is sufficient to reverse MDR has yet to be validated. This study demonstrated that RNAi-based knockdown of MRP1 reversed the increased efflux ability and MDR efficiently.

[Current situation related to antiretroviral therapy and related influential factors on HIV infected injection drug users in the methadone maintenance treatment clinics].

Objective: To find out the current coverage of antiretroviral therapy (ART) among HIV positive subjects and to identify the major influential factors associated with the participation in ART among them.

Methods: 291 HIV positive subjects from 6 methadone maintenance treatment (MMT) clinics in Guangxi and Yunnan province were surveyed by questionnaires.

Results: 217 males (74.

[Factors associated with overdose-caused mortality of HIV-positive patients who were on methadone maintenance treatment program].

Objective: To study the factors that associated with the mortality of overdose on methadone maintenance treatment(MMT)among HIV-positive patients.

Methods: A 1 : 1 matched case-control design was used to identify the relationship between factors related to demography, drug use, characteristics of treatment and the mortality of overdose. 110 HIV-positive patients who died of drug overdose from March 2004 to September 2012 were defined as cases.

Real-time endocytosis imaging as a rapid assay of ligand-GPCR binding in single cells.

Most G protein-coupled receptors (GPCRs) do not generate membrane currents in response to ligand-receptor binding (LRB). Here, we describe a novel technique using endocytosis as a bioassay that can detect activation of a GPCR in a way analogous to patch-clamp recording of an ion channel in a living cell. The confocal imaging technique, termed FM endocytosis imaging (FEI), can record ligand-GPCR binding with high temporal (second) and spatial (micrometer) resolution.

[Characteristics and associated factors of long-term retention for methadone maintenance treatment patients].

Objective: To describe the characteristics and factors associated with long-term retention for methadone maintenance treatment (MMT) patients.

Methods: This study was conducted in eight MMT clinics located in Sichuan, Yunnan, Guangxi, Guizhou and Zhejiang provinces. Five hundred and thirty-nine MMT patients who enrolled in MMT clinics in 2004 and retained in treatment by June 2010 were selected as study subjects.

[Evaluation on the long-term effectiveness among the first set eight methadone maintenance treatment clinics in China].

Objective: To evaluate the long-term effectiveness of the first set 8 methadone maintenance treatment (MMT) clinics in China.

Methods: Repeated cross-sectional surveys were conducted on the first month after the enrollment and 5 years later, among drug users who received MMT, using a standard questionnaire. Data on demographic characteristics, HIV-related high-risk behaviors, criminal records associated with drug use and related family/social functions were collected and analyzed.

[Conserved motifs in voltage sensing proteins].

This paper was aimed to study conserved motifs of voltage sensing proteins (VSPs) and establish a voltage sensing model. All VSPs were collected from the Uniprot database using a comprehensive keyword search followed by manual curation, and the results indicated that there are only two types of known VSPs, voltage gated ion channels and voltage dependent phosphatases. All the VSPs have a common domain of four helical transmembrane segments (TMS, S1-S4), which constitute the voltage sensing module of the VSPs.

Validation and application by HPLC for simultaneous determination of vitexin-2″-O-glucoside, vitexin-2″-O-rhamnoside, rutin, vitexin, and hyperoside.

A simple, precise, and rapid high-performance liquid chromatographic method was developed and validated for the simultaneous determination of vitexin-2″-O-glucoside, vitexin-2″-O-rhamnoside, rutin, vitexin, and hyperoside. The HPLC separation was performed using a Shim-pack VP-ODS C column (250 mm×4.6 mm i.

[Determination of supermolecular inclusion constants of hydroxylpropyl-beta-cylcodextrin with imperatorin and isoimperatorin by phase solubility method].

Objective: To study the supermolecular interaction between different concentrations of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and imperatorin (IM) and isoimperatorin (ISO) using phase solubility analysis.

Methods: Different concentrations of hydroxypropyl-beta-cyclodextrin were prepared, added overdose of imperatorin or isoimperatorin, made a phase solubility diagram.

Results: The relationship of phase solubility was approximatively linear and the model of inclusion compound was AL and the inclusion ratio of IM, ISO versus HP-beta-CD was 1: 1.

Two distinct vesicle pools for depolarization-induced exocytosis in somata of dorsal root ganglion neurons.

The somata of dorsal root ganglion (DRG) neurons release neurotransmitters and neuropeptides. In addition to the conventional Ca2+-dependent secretion (CDS), Ca2+-independent but voltage-dependent secretion (CIVDS) also occurs in the somata of DRG neurons. Electrical stimulation induces both CDS and CIVDS, which differ in size and are coupled with different types of endocytosis contributed by CIVDS and CDS, respectively.

Co-transfection and tandem transfection of HEK293A cells for overexpression and RNAi experiments.

pIRES2-EGFP was employed and a non-target shRNA expressing plasmid was constructed to simulate overexpression and RNAi (RNA interference) experiments. Transfection of pIRES2-EGFP into HEK293A cells by cationic lipids VigoFect demonstrated that transfection efficiency increased in a dose-dependent manner with amount of DNA plasmid used, and optimal transfection time and cell density should be identified to reach a compromise of higher transfection efficiency and lower toxicity. Co-transfection experiments indicated that the two co-transfected plasmids were equivalently delivered into the same cells, and the co-transfection efficiency was rarely affected by cell density and proportion of the two plasmids.

[Risk factors which were associated with heroin use during the methadone maintenance treatment among 1301 patients in 9 cities of China.].

Objective: To determine the proportion of heroin use among patients who were involved in community-based methadone maintenance treatment (MMT) program and to identify the risk factors associated with heroin use.

Methods: This study was conducted in 9 MMT clinics within 3 provinces. Thirteen hundred and one patients who met the study criteria were selected from each of the five groups with different dosages of methadone users.

The use of solid lipid nanoparticles to target a lipophilic molecule to the liver after intravenous administration to mice.

Taspine solid lipid nanoparticles (Ta-SLN) and taspine solid lipid nanoparticles modified by galactoside (Ta-G2SLN) were prepared by the film evaporation-extrusion method. The nanoparticles were spherical or near-spherical particles with smooth surface, small size and high encapsulation efficiency. Ta-G2SLN and Ta-SLN showed significant inhibition on 7721 cell growth.

[Evaluation of first 8 pilot methadone maintenance treatment clinics in China].

Objective: To evaluate the effectiveness of the first eight pilot methadone maintenance treatment (MMT) clinics in China.

Methods: A questionnaire survey of the clients at the 8 pilot MMT clinics was performed at entry, 6 month and 12 month follow-up. Drug using behaviors, drug related crime behaviors, and relationships in families were compared among at entry, 6 and 12 months follow-up.