Simultaneous determination of BGT-002 and its acyl glucuronide metabolite ZM326E-M2 in human plasma by liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study.

BGT-002, a new type of ATP-citrate lyase inhibitor, is a promising therapeutic for treatment of hypercholesterolemia. After an oral administration of BGT-002 to subjects, it underwent extensive metabolism and an acyl monoglucuronide (ZM326E-M2) on 1- carboxylic acid group was the major circulating metabolite. In this study, an LC-MS/MS method was developed and validated for the simultaneous determination of BGT-002 and ZM326E-M2 in plasma and the evaluation of their pharmacokinetic characteristics in humans. After extraction from the plasma by acetonitrile-induced protein precipitation, the analytes were separated on a Waters ACQUITY UPLC® BEH C18 column using acetonitrile and 2 mM ammonium acetate containing 0.1% formic acid as the mobile phase for gradient elution. Negative electrospray ionization was performed using multiple reaction monitoring (MRM) of m/z 501.3→325.4 for ZM326E-M2 and m/z 507.3→331.2 for D6-ZM326E-M2, and pseudo-MRM of m/z 325.3→325.3 for BGT-002 and m/z 331.3→331.3 for D6-ZM326E, respectively. The method was validated with respect to accuracy, precision, linearity, stability, selectivity, matrix effect, and recovery. The analytical range in human plasma was linear over a concentration range of 0.0500-50.0 µg/mL for BGT-002 and 0.0100-10.0 µg/mL for ZM326E-M2. The pharmacokinetic results showed that after a single oral administration of 100 mg BGT-002, the parent drug was rapidly absorbed with a mean time to peak concentration (tmax) of 1.13 h, compared with BGT-002, the tmax (4.00 h) of ZM326E-M2 was significantly delayed. The peak concentration and plasma exposure of ZM326E-M2 were about 14.1% and 19.5% of the parent drug, suggesting that attention should be paid to the safety and efficacy of ZM326E-M2 in clinical research.

Genome-wide identification and functional analysis of the cellulose synthase-like gene superfamily in common oat (Avena sativa L.).

Hemicelluloses constitute approximately one-third of the plant cell wall and can be used as a dietary fiber and food additive, and as raw materials for biofuels. Although genes involved in hemicelluloses synthesis have been investigated in some model plants, no comprehensive analysis has been conducted in common oat at present. In this study, we identified and systematically analyzed the cellulose synthase-like gene (Csl) family members in common oat and investigated them using various bioinformatics tools. The results showed that there are 76 members of the oat Csl gene family distributed on 17 chromosomes, and phylogenetic analysis indicated that the 76 Csl genes belong to the CslA, CslC, CslD, CslE, CslF, CslH, and CslJ subfamilies. A total of 14 classes of cis-acting elements were identified in the promoter regions, including hormone response, light response, cell development, and defense stress elements. The collinearity analysis identified 28 pairs of segmentally duplicated genes, most of which were found on chromosomes 2D and 6A. Expression pattern analysis showed that oat Csl genes display strong tissue-specific expression; of the 76 Csl genes, 33 were significantly up-regulated in stems and 30 were up-regulated in immature seeds. The expression of most members of the AsCsl gene family is repressed by abiotic stress, while the expression of some members is up-regulated by light. Immunoelectron microscopy shows that the product of AsCsl61, a member of CslF subfamily, mediates (1,3; 1,4)-ß-D-glucan synthesis in transgenic Arabidopsis. These findings provide a fundamental understanding of the structural, functional, and evolutionary features of the oat Csl genes and may contribute to our general understanding of hemicellulose biosynthesis. Moreover, this information will be helpful in designing experiments for genetic manipulation of mixed-linkage glucan (MLG) synthesis with the goal of quality improvement in oat.

LncRNA SNHG4 sponges miR-200b to inhibit cell apoptosis in diabetic retinopathy.

This study aimed to investigate the role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 4 (SNHG4) in diabetic retinopathy (DR). We found that SNHG4 was downregulated in DR. SNHG4 could directly interact with miR-200b, while overexpression of miR-200b did not affect the expression of SNHG4 in human retinal pigment epithelial cells ARPE-19. In contrast, overexpression of SNHG4 led to the upregulation of oxidation resistance 1 (Oxr1), a target of miR-200b. Cell apoptosis analysis showed that overexpression of miR-200b increased the apoptotic rate of ARPE-19 cells under high glucose treatment. Oxr1 and SNHG4 played opposite roles and reduced the effects of overexpression of miR-200b. In conclusion, SNHG4 may sponge miR-200b to inhibit cell apoptosis in DR by upregulating Oxr1.

Application of oblique nerve coaptation in autologous nerve transplantation.

BACKGROUND: Autologous nerve transplantation has become the gold standard for other nerve repair methods. But conventional epineurial sutures is prone to misaligned sutures, erroneous axonal growth, and unsatisfactory repair. Finding a new, more effective nerve coaptation method to improve the efficacy of peripheral nerve repair remains an urgent clinical challenge. In this study, the repair efficacies of oblique nerve coaptations for sciatic nerve injury at various angles were observed, providing a theoretical foundation for further clinical applications. METHODS: Sixty-four Sprague-Dawley rats were randomized into four groups of 16. The autologous nerve transplantation model was established by severing and rejoining in situ a 10-mm segment of the sciatic nerve trunk at the angle of 30° (group A), 45° (group B), 60° (group C), or 90° (group D). Sciatic function index (SFI) measurement, measurement of the recovery rate of the wet weight of the triceps surae, electrophysiological examination of nerves, histological examinations, and image analysis were carried out 12 weeks after surgery. RESULTS: The SFI, the recovery rate of the wet weight of the triceps surae, the electrophysiological function of nerves, histological examinations, and image analysis 12 weeks after surgery indicated that all indices of groups A and B were significantly better than those of groups C and D (P<0.05). There was no significant difference between groups A and B or between groups C and D (P>0.05), although group C exhibited a trend of better recovery than group D. CONCLUSIONS: Oblique nerve coaptation at 30-45° in autologous nerve transplantation may significantly enhance nerve regeneration.

The Fluorescence Enhancement of Mercury Detected in Food Based on Rhodamine Derivatives.

Recently, the problem of food security is more and more serious, and people pay attention to mercury because of the toxic of it. A new approach for the determination of mercury content in foodstuff is devised. In this paper, first, we design and synthesis a new kind of fluorescent probe whose matrix based on rhodamine B, hydrazine hydrate and hydroxy benzaldehyde. Through the analysis of H-NMR spectra of the synthesized product L1, we confirm that the synthetic substance is the adjacent carboxyl benzaldehyde hydrazone structure generation of rhodamine B. Then, we measure the fluorescence signal intensity of the probe with different concentrations of mercury ions fully upon complexation by fluorescence spectrometer and we can study the relationship between the mercury ion concentration and the fluorescence intensity and draw the standard working curve. Following, It's time to discuss the microwave digestion processing of tea, after digestion we use the synthetic probe Li for determination of mercury content in tea. The experimental results show that the maximum excitation wavelength of the probe and coordination compound are 568. 05 and 560. 00 nm, the maximum emission wavelength are 587. 94 and 580. 00 nm. Then we can find the best testing conditions to improve the degree of accuracy, that is: room temperature, 50% the methanol solution, 3. 0 mL pH 4. 0 buffer solution, in the extent of 30 min. The experimental results show that Na+, K+, Ca2+, Cu2+, Zn2+, Al3+ have little impact on the fluorescence intensity of the:probe. Fe3+, Mg2+, Ba2+ has a weak enhancement to the fluorescence intensity of the probe. While a low concentrations of Hg2+ have an obviously enhanced effect on the fluorescence intensity of the probe. In contrast to other metal ions, the probe for Hg2+ has a good selectivity. Linear relationship between the magnitude of increase in fluorescence intensity and concentration of mercury ion was in the range of 5~20 ng . L-1 with detection limit (3S/N) of 1. 9 ng . L-1. The proposed method was applied to determination of mercury ion in samples of tea and sausage and the obtained result and sample recovery were all satisfactory. The methods of analysis instrument has the advantages of simple structure, sensitivity, high accuracy, good selectivity and less volume of simple, without the need for enrichment, being very practical.

Capillary electrophoresis applied to screening of trypsin inhibitors using microreactor with trypsin immobilized by glutaraldehyde.

An efficient and durable online capillary immobilized trypsin microreactor was successfully established to study the enzyme kinetics of trypsin and screen its inhibitors from natural extracts through capillary electrophoresis (CE). In this procedure, trypsin was immobilized on the inner wall at the inlet of the capillary treated with 3-aminopropyltrimethoxy silane (3-APTES), producing a trypsin microreactor via cross-linking of glutaraldehyde with 3-APTES and trypsin. The rest of the capillary was selected as a channel for separating the generated product and unreacted substrate of the trypsin enzymatic reaction. The parameters affecting the separation efficiency and activity of immobilized trypsin were evaluated systematically. The optimized conditions were as follows: 50 mM Tris-HCl (pH 8.0), 15 kV, 37 °C, 10 mM substrate, incubation for 2 min. Under optimal conditions, separation of the product and substrate was achieved through CE within 3.5 min. The obtained results of Michaelis constant, inhibition kinetics constant, and half-maximal inhibitory concentration for the immobilized trypsin using benzamidine hydrochloride hydrate as a model inhibitor were 1.56, 1.79 and 3.98 mM, respectively. The proposed method was successfully applied for screening of trypsin inhibitors from 19 kinds of natural extracts.

The controlled release of tilmicosin from silica nanoparticles.

The aim of this study was to use silica nanoparticles as the carrier for controlled release of tilmicosin. Tilmicosin was selected as a drug model molecule because it has a lengthy elimination half-life and a high concentration in milk after subcutaneous administration. Three samples of tilmicosin-loaded silica nanoparticles were prepared with different drug-loading weight. The drug-loading weight in three samples, as measured by thermal gravimetric analysis, was 29%, 42%, and 64%, respectively. With increased drug-loading weight, the average diameter of the drug-loaded silica nanoparticles was increased from 13.4 to 25.7 nm, and the zeta potential changed from-30.62 to-6.78 mV, indicating that the stability of the drug-loaded particles in the aqueous solution decreases as drug-loading weight increases. In vitro release studies in phosphate-buffered saline showed the sample with 29% drug loading had a slow and sustained drug release, reaching 44% after 72 h. The release rate rose with increased drug-loading weight; therefore, the release of tilmicosin from silica nanoparticles was well-controlled by adjusting the drug loading. Finally, kinetics analysis suggested that drug released from silica nanoparticles was mainly a diffusion-controlled process.