[Trapping array-based preparative two-dimensional liquid chromatography for the purification of four components in tobacco leaves].

Two-dimensional liquid chromatography (2D-LC) has gained increased attention because of its high peak capacity for separating complex samples. However, preparative 2D-LC aimed at isolating compounds is significantly different compared with one-dimensional liquid chromatography (1D-LC) in terms of method development and system configuration; thus, it is less developed than its analytical counterpart. The use of 2D-LC in large-scale product preparation has rarely been reported. Hence, a preparative 2D-LC system was developed in this study. The system was composed of one set of preparative LC modules as a separation system, with a dilution pump, switch valves, and trap column array as the interface, to enable the simultaneous isolation of several compounds. Tobacco was used as a sample, and the developed system was applied to isolate nicotine, chlorogenic acid, rutin, and solanesol. The chromatographic conditions were developed by investigating the trapping efficiency of different types of trap column packings, and chromatographic behaviors under different overload conditions. The four compounds were isolated in one 2D-LC run with high purity. The developed system features low cost because it employs medium-pressure isolation, excellent automation owing to its use of an online column switch, high stability, and capability for large-scale production. The isolation of chemicals from tobacco leaves as pharmaceutical raw materials could aid in the development of the tobacco industry and promote the local agricultural economy.

Nitric Oxide Signaling Pathway in Ventral Tegmental Area is Involved in Regulation of 7,8-Dihydroxyflavone on Alcohol Consumption in Rats.

We recently reported that intraperitoneal injection of 7,8-dihydroxyflavone (7,8-DHF), a brain-derived neurotrophic factor-mimicking small compound, could attenuate alcohol-related behaviors in a two-bottle choice ethanol consumption procedure (IA2BC) in rats via tropomyosin receptor kinase B in the ventral tegmental area (VTA), which is closely related to alcohol use disorder. However, the detailed mechanisms underlying the regulation of 7,8-DHF on alcohol drinking behavior remain elusive. In this study, we determined the role of nitric oxide (NO), a pleiotropic signaling molecule, in the VTA in the action of 7,8-DHF upon alcohol drinking behavior. Intermittent alcohol exposure led to the overexpression of NO in the VTA, especially 72 h after withdrawal from four weeks of ethanol exposure in IA2BC rats. A higher amount of alcohol intake was also found at the same time point, consistent with the overexpression of NO in the VTA. Microinjection of NG-Nitro-l-Arginine Methyl Ester, (NO synthase inhibitor) or 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NO scavenger) into the VTA inhibited alcohol intake, whereas application of S-Nitroso-N-acetyl-DL-penicillamine (SNAP, the NO donor) in the VTA further enhanced alcohol consumption in IA2BC rats. Interestingly, either 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (a sGC inhibitor) or KT5823 [a selective protein kinase G (PKG) inhibitor] blocked NO's enhancing effect on ethanol intake. Intraperitoneal injection of 7,8-DHF reduced the overexpression of NO; SNAP microinjected into the VTA reversed the inhibitory effects of 7,8-DHF on alcohol consumption. Our findings suggest that NO-cGMP-PKG might be involved in regulation of 7,8-DHF on alcohol consumption in IA2BC rats.

Efficiently capturing tobacco specific nitrosamines with Hß zeolite in solution.

The high-efficiency capture of Tobacco Specific Nitrosamines by Hß zeolite in solution is reported for the first time, along with the adsorption of 4-methylnitrosamino-1-3-pyridyl-1-butanone in aqueous solution. Different from other zeolites such as NaZSM-5, the specific pore size of Hß exerted a crucial function endowing the zeolite a higher removal of TSNA and selectivity of NNK. The adsorption thermodynamics of NNK by Hß in aqueous adsorption was fitted to Temkin adsorption model with a linearly decreasing isosteric heat of adsorption. In addition, the adsorptive capacity of Hß zeolite for NNK reached over 70 mg g-1, offering a powerful sorbent of TSNA to protect environment.

Transoral laser microsurgery versus radiotherapy for T1 glottic carcinoma: a systematic review and meta-analysis.

Transoral laser microsurgery (TLM) and radiotherapy (RT) are both accepted treatment modalities for glottic cancer. The objective of the study was to assess the oncologic outcomes and life quality of TLM in comparison with RT for T1 glottic carcinoma. We searched Medline/PubMed, Web of knowledge, EMBASE, the Cochrane Library, the Wiley online library, Springer, Google, China National Knowledge Infrastructure (CNKI), etc. We screened the literature, assessed the quality of the studies, and extracted the relevant data through the establishment of inclusion and exclusion criteria. Meta-analysis was done using the Cochrane collaboration' s RevMan 5.0 for data analysis. A total of 11 studies were included in this meta-analysis. The laryngeal preservation for patients undergoing TLM was significantly better than that for RT (P < 0.00). The laser surgery significantly improved the overall survival of patients with T1 glottic carcinoma (P = 0.04). No statistically significant differences were found between TLM and RT regarding the local control (P = 0.91). The funnel plot demonstrates no apparent publication bias in the overall survival and laryngeal preservation comparison. Our meta-analysis suggested that laser surgery was a preferred method than radiotherapy with respect to significantly better overall survival and laryngeal preservation. But the local control was not significant different. Further prospective randomized controlled studies will be needed.