Expression of arginyl-tRNA synthetase in rats with focal cerebral ischemia.

Aminoacyl-tRNA syntheses (AARS) can catalyze the adenosine triphosphate (ATP)-dependent acylation of their cognate tRNA(s) with a specific amino acid. They can be seen as an index to reflect the energy metabolic rate of ischemic brain cells in ischemic penumbra. This study examined the relationship between arginyl-tRNA synthetase (ArgRS), one of the AARS, and cerebral ischemia in rats. The model of middle cerebral artery occlusion (MCAO) was established in rats. The expression levels of ArgRS protein and mRNA were detected in rat brain tissues at different time points following MCAO by Western blotting and RT-PCR, respectively. The results showed that the MCAO model was successfully established. Western blotting and RT-PCR analysis revealed that the ArgRS protein and mRNA were expressed in brain cells in both ischemic and normal penumbra tissues. The expression levels of ArgRS protein and mRNA peaked at 6 h after MCAO and decreased gradually. At 24 h, the expression levels of ArgRs protein and mRNA in ischemic penumbral tissues were lower than those in normal tissues. The expression levels of ArgRS mRNA and protein in ischemic penumbra varied with ischemic time, suggesting that the energy metabolism of brain cells in penumbra changed dynamically after ischemia to ensure the endogenous self-protection of the body. The brain oxygen supply should be improved as soon as possible, especially within 6-12 h after ischemia, so as to meet the demand for energy metabolism in ischemic penumbra and make sure the cell structure remains stable.

Health-related quality-of-life after traumatic brain injury: a 2-year follow-up study in Wuhan, China.

OBJECTIVE: To assess health-related quality-of-life (HRQoL) 2 years after traumatic brain injury (TBI) among a group of Chinese. METHODS: A total of 358 adult patients with moderate-to-severe TBI based on Glasgow Coma Scale score were recruited in a large trauma centre in Wuhan, China during May 2005 to April 2008. They were followed up for 2 years and the Medical Outcome Short Form 36 was used to measure HRQoL. RESULTS: After a 2-year follow-up, there were 312 (87.2%) survivors. All domains of HRQoL had the lowest scores at discharge, greatly improved over the first 6 months and showed continued improvement. Patients with TBI still had significantly lower scores in every domain than the reference group 2 years after discharge. Female patients had lower MCS scores than the males (OR = 1.8, 95% CI: 1.1-2.9). Patients older than 30 had lower scores in PCS (OR = 1.7, 95% CI: 1.1-2.6). Patients with severe TBI had lower scores in both PCS (OR = 1.9, 95% CI: 1.2-3.1) and MCS (OR = 1.6, 95% CI: 1.0-2.6) compared with those with moderate TBI. CONCLUSIONS: HRQoL of a group of Chinese patients with TBI improved during 2 years after discharge. Age, sex and severity of TBI were significantly associated with physical or mental HRQoL after discharge.

A ratiometric fluorescent sensing of proanthocyanidins by MnO2 nanosheets simultaneously tuning the photoluminescence of Au/AgNCs and thiamine.

By simultaneously regulating the photoluminescence of alloy Au/Ag nanoclusters (NCs) and thiamine (VB1) through MnO2 nanosheets (MnO2 NS), a novel ratiometric fluorescent probe (RF-probe) was established for sensitively and selectively monitoring proanthocyanidins (PAs). The introduction of Ag (I) ions could enhance significantly the quantum yields (QYs, 11.1%) of AuNCs based on the synthetic method of UVI (UV irradiation) combined with MWH (microwave heating). MnO2 NS could quench the fluorescence (FL) of Au/AgNCs mainly coming from Förster resonance energy transfer (FRET), while it could act as a nanozyme catalyst for directly catalyzing the oxidation of VB1 to produce highly fluorescent oxVB1. In the presence of PAs, MnO2 was reduced to Mn2+, which caused that its quenching capacity and oxidase-like activity were vanished, thus the FL of oxVB1 and Au/AgNCs was reduced and recovered. The concentration of PAs could be monitored by the RF-probe with a linear range of 0.27-22.4 µmol L-1 and corresponding limit of detection (LOD) and limit of quantification (LOQ) were calculated to be 75.9 and 250.5 nmol L-1. Furthermore, the RF-probe was successfully used for the determination of PAs in mineral water, PAs additive and PAs capsule with satisfactory results compared to the standard HPLC method.

Polymorphisms in DNA repair gene XRCC1 and increased genetic susceptibility to glioma.

BACKGROUND: The XRCC1 gene encodes the XRCC1 protein, which complexes with three other DNA repair enzymes involved in the base-excision repair (BER) pathways. Different XRCC1 polymorphisms may increase the risk of cancers by impairing interaction with other enzymatic proteins and consequently altering DNA repair activity, and result in carcinogenesis. Our study aimed to investigate any association between three polymorphisms of the XRCC1 gene at codon 194, 280 and 399 and potential glioma risk. METHODS: We collected 127 patients with primary glioma and 249 controls who requested general health examinations from Union Hospital of Tongji Medical College hospital from March 2007 to September 2010. A total of 5 ml venous blood was drawn from each subject. The polymorphisms of XRCC1 gene at codons 194, 280 and 399 were analyzed based on duplex polymerase-chain-reactions with the confronting-two-pair primer (PCR-CTPP) method. RESULTS: The homozygous Trp/Trp and heterozygotes Arg/Trp variants of codon 194 had a 2.12 fold and 1.46 fold increased risk of glioma compared to the homozygous Arg/Arg wide genotypes. The same effect was found in codon 399, the codon 399 Gln/Gln and Arg/Gln genotypes being associated with a 2.24 fold and 1.67 fold increased risk in glioma. When comparing the codon 194 Arg/Arg and 399 Arg/Arg genotypes, the combination of codon 194 Trp allele and 399 Gln allele had a heavy increase in glioma risk (OR=2.87, 95%CI=1.56-6.73). CONCLUSION: The present study provided evidence of a potential role for XRCC1 codon 194 and 399 polymorphisms in genetic predisposition to glioma among the Chinese population. This analysis of correlation of DNA repair genes and glioma may provide a deeper insight into the genetic and environment factors for cancer risk.