Structure screening and performance restoration of chiral separation materials based on chitosan derivatives.

In order to screen chiral selector structure and find structure-property relationship, ten chitosan 3,6-bis(phenylcarbamate)-2-(cyclopropylformamide)s were synthesized from which corresponding chiral stationary phases were prepared. Enantioseparation capability and mobile phase tolerability of the chiral stationary phases were evaluated. The chiral selectors with 3-chloro-4-methylphenyl, 4-chlorophenyl, 3-chlorophenyl, 3,5-dichlorophenyl and 4-trifluoromethoxyphenyl groups demonstrated powerful enantioseparation capability. Enantioseparation capability was found to be dependent on a match between the substituent at C2 and the one attached to phenyl group at C3/C6 of glucose unit in the chitosan derivatives. Moreover, the tolerability tests revealed that the developed chiral stationary phases were highly tolerable to pure ethyl acetate, pure acetone and n-hexane/tetrahydrofuran of various ratios. In addition, n-hexane/tetrahydrofuran was found to be a modifier to adjust suprastructure of the chitosan derivatives, resulting in an improvement or restoration in enantioseparation. This observation implies n-hexane/tetrahydrofuran may make a damaged chiral selector restore its enantioseparation capability.

N-Acylated chitosan bis(arylcarbamate)s: A class of promising chiral separation materials with powerful enantioseparation capability and high eluents tolerability.

In order to comprehensively understand the influence of coordination of the substituent at 2-position with those at 3- and 6-positions on the properties of chitosan derivatives, a series of chitosan 3,6-bis(arylcarbamate)-2-(amide)s (CACAs) and the related chiral stationary phases (CSPs) were prepared and reported in the present study. Specifically, chitosan was N-acylated with carboxylic acid anhydrides, and then further derivatized with various aryl isocyanates to afford CACAs, from which a class of coated-type CSPs were prepared. When the substituent introduced on the acyl group at 2-position and those on the phenyl group of the carbamates at 3- and 6-positions were fittingly combined, these prepared CACAs based CSPs would exhibit powerful chiral recognition ability, further resulting in a class of promising chiral separation materials with excellent enantioseparation performance. Meanwhile, these newly developed materials with suitable molecular weight also bear a high tolerability towards organic solvents, even including pure tetrahydrofuran, thus broadening their application in enantiomeric separation.

LYAR promotes colorectal cancer cell mobility by activating galectin-1 expression.

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. However, the molecular mechanisms of CRC pathogenesis are not fully understood. In this study, we report the characterization of LYAR (Ly-1 antibody reactive clone) as a key regulator of the migration and invasion of human CRC cells. Immunohistochemistry analysis demonstrated that LYAR is expressed at a higher level in metastatic CRC tissues. We found that LYAR promoted the migratory and invasive capabilities of CRC cells. Gene expression profile analysis of CRC cells showed that LGALS1, which encodes the galectin-1 protein, was a potential target of LYAR. The ChIP assay and gene reporter assays indicated that LYAR directly bound to the LGALS1 promoter. The ectopic expression of galectin-1 partially restored the mobile potential of LYAR knocked-down cells, which suggests that galectin-1 contributed to the LYAR-promoted cell migration and invasion of CRC cells. Thus, this study revealed a novel mechanism by which the transcription factor LYAR may promote tumor cell migration and invasion by upregulating galectin-1 gene expression in CRC.

The Uptake of Prevention of Mother-to-Child HIV Transmission Programs in China: A Systematic Review and Meta-Analysis.

BACKGROUND: No systematic review of prevention of mother to child transmission (PMTCT) in China has been performed. We aimed to estimate the uptake of PMTCT programs services in China. METHODS: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, and Wanfang (Chinese) to identify research studies. Only descriptive epidemiological studies were eligible for this study. RESULTS: A total of 57 eligible cross-section studies were finally included. We estimated that the mean HIV-positive rate of exposed infants was 4.4% (95% CI = 3.2-5.5), and more than 33% of exposed infants had not undergone HIV diagnostic testing. The percentage of initiating antiretroviral therapy (ART) in HIV-positive women was 71.0% (95% CI = 66.3-75.8), and that for initiating antiretroviral prophylaxis (ARP) in exposed infants was 78.3% (95% CI = 74.9-81.8); also, 31.3% (95% CI = 15.5-47.0) of women with HIV and < 1% of exposed infants received the combination of three antiretroviral drugs. There were bigger gap of uptake of PMTCT programs between income levels, and cities with a low income level had a higher percentage of initiating ART in HIV-positive women (80%) and ARP in exposed infants (85%) compared to cities with high-middle income (57% and 65%, respectively) (P<0.05). CONCLUSIONS: This paper highlights the need to further scale up PMTCT services in China, especially in regions with the lowest coverage, so that more women can access and utilize them. However, some estimated outcome should be interpreted with caution due to the high level of heterogeneity and the small number of studies.

Gene diagnosis for nine Chinese patients with DMD/BMD by multiplex ligation-dependent probe amplification and prenatal diagnosis for one of them.

This study aims to perform gene diagnosis for nine patients with Duchenne/Becker muscular dystrophy (DMD/BMD) and their parents with multiplex ligation-dependent probe amplification (MLPA), and to carry out prenatal gene diagnosis for one of them. Genomic DNA of the peripheral blood and fetal amniotic fluid cell was extracted from the pedigrees' members with DMD/BMD. Gene diagnosis was performed for theses pedigrees' members using a SALSA KIT. Short tandem repeats (STR) genotyping and X-linkage analysis were performed for the pedigree members of the fetus, which was used in the prenatal diagnosis. MLPA analysis results show that five of nine patients (DMD-1, DMD-2, DMD-4, DMD-8, and DMD-9) with DMD/BMD were found to have several hemizygous exon deletions in the dystrophin gene. The other patients and the fetus did not have any hemizygous deletion or duplication of any exons. The genomic DNA of the fetus was not contaminated by his mother's DNA as identified by STR genotyping. In addition, X-linkage analysis results show that the only X chromosome of the fetus comes from one of his mother's normal X chromosomes. Combined with STR genotyping and X-linkage analysis, MLPA is a convenient, highly effective and reliable gene diagnosis technique for congenital genetic disease.

An HPLC method for the determination of ng mifepristone in human plasma.

An HPLC method was developed and validated for the determination of mifepristone in human plasma. C(18) solid-phase extraction cartridges were used to extract plasma samples. Separation was by C(18) column; mobile phase, methanol-acetonitrile-water (50:25:25, v/v/v); flow rate, 0.8 ml/min; UV detection at 302 nm. The calibration curve was linear in the concentration range of 10 ng/ml to 20 microg/ml (r=0.9991). Within- and between-day variability were acceptable. The limit of detection for the assay was 6 ng/ml. Plasma samples were stable for at least 7 days in the state of plasma or residue treated at -20 degrees C. The method was simple, sensitive and accurate, and allowed to determine ng mifepristone in human plasma. It could be applied to assess the plasma level of mifepristone in women receiving low oral doses of mifepristone.