Structural elucidation of in vivo metabolites of penehyclidine in rats by the method of liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry and isotope ion cluster

The structural elucidation of metabolites of penehyclidine in rats, a novel anti-cholinergic drug, by the method of liquid chromatography-electrospray ionization mass spectrometry, gas chromatography-mass spectrometry with electron impact ion source and stable isotope ion cluster was described. Identification and elucidation of the phase I and phase II metabolites were performed by comparing the daughter ion pairs of stable isotope cluster, changes of the protonated molecular masses, full scan MS(n) spectra and retention times with those of the parent drug, penehyclidine and penehyclidine deuterium-labeled. Penehyclidine was easily biotransformed by the pathways of oxidative, hydroxylated, methoxylated and phase II conjugated reactions to form several metabolites that retained the some features of the parent molecules. Twelve metabolites (penehyclidine monoxide, hydroxypenehyclidine, penehyclidine dioxide, hydroxypenehyclidine monoxide, dihydroxypenehyclidine, dihydroxypenehyclidine (position isomer), dihydroxypenehyclidine monoxide, trihydroxypenehyclidine, methoxypenehyclidine dioxide, dimethoxypenehyclidine, trihydroxymethoxypenehyclidine and glucuronide conjugated hydroxypenehyclidine) were identified. The results from electrospray ion and electron impact ion data with the stable isotope cluster showed the qualitative differences in the mass spectral patterns, suggesting that these technologies should be used in parallel to ensure comprehensive metabolites detection and characterization. The described method has wide applicability to rapidly screen and provide structural information of metabolites.     

Molecular survey and characterization of Theileria annulata and Ehrlichia ruminantium in cattle from Northwest China

Theileriosis and ehrlichiosis are two important tick-borne diseases affecting cattle farming in China. However, limited information is available regarding prevalence and molecular characterization of Theileria annulata and Ehrlichia ruminantium in cattle in Xinjiang Uygur Autonomous Region (XUAR), northwestern China. In this study, a total of 176 blood samples of cattle from three rural areas of XUAR were collected in June 2017 and were tested by nested-PCR. A total of 34 (19.3%) samples were found to be infected with one or two pathogens. The overall prevalence rates of T. annulata and E. ruminantium were 18.2% and 1.7%, respectively. Phylogenetic analyses revealed that the E. ruminantium isolates from XUAR were located in the same clade but diverged from the isolates from African countries using pCS20 gene while T. annulata isolates from XUAR revealed differences in the genotypes using Tams1 sequences. To our knowledge, this is the first report of E. ruminantium infection in cattle in China. It also provides the first genetic characterization of T. annulata in cattle in XUAR. The current findings are important for understanding the distribution of agents of theileriosis and ehrlichiosis and in designing measures for the prevention and control of tick-borne diseases in cattle, other animals, and humans.     

Vascular endothelial growth factor-B: Impact on physiology and pathology

Angiogenesis plays an important role in controlling tissue development and maintaining normal tissue function. Dysregulated angiogenesis is implicated in the pathogenesis of a variety of diseases, particularly diabetes, cancers, and neurodegenerative disorders. As the major regulator of angiogenesis, the vascular endothelial growth factor (VEGF) family is composed of a group of crucial members including VEGF-B. While the physiological roles of VEGF-B remain debatable, increasing evidence suggests that this protein is able to protect certain type of cells from apoptosis under pathological conditions. More importantly, recent studies reveal that VEGF-B is involved in lipid transport and energy metabolism, implicating this protein in obesity, diabetes and related metabolic complications. This article summarizes the current knowledge and understanding of VEGF-B in physiology and pathology, and shed light on the therapeutic potential of this crucial protein.     

Dissection of two quantitative trait loci with pleiotropic effects on plant height and spike length linked in coupling phase on the short arm of chromosome 2D of common wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Key message

Two QTL with pleiotropic effects on plant height and spike length linked in coupling phase on chromosome 2DS were dissected, and diagnostic marker for each QTL was developed.

Abstract

Plant height (PHT) is a crucial trait related to plant architecture and yield potential, and dissection of its underlying genetic basis would help to improve the efficiency of designed breeding in wheat. Here, two quantitative trait loci (QTL) linked in coupling phase on the short arm of chromosome 2D with pleiotropic effects on PHT and spike length, QPht/Sl.cau-2D.1 and QPht/Sl.cau-2D.2, were separated and characterized. QPht/Sl.cau-2D.1 is a novel QTL located between SNP makers BS00022234_51 and BobWhite_rep_c63957_1472. QPht/Sl.cau-2D.2 is mapped between two SSR markers, SSR-2062 and Xgwm484, which are located on the same genomic interval as Rht8. Moreover, the diagnostic marker tightly linked with each QTL was developed for the haplotype analysis using diverse panels of wheat accessions. The frequency of the height-reduced allele of QPht/Sl.cau-2D.1 is much lower than that of QPht/Sl.cau-2D.2, suggesting that this novel QTL may be an attractive target for genetic improvement. Consistent with a previous study of Rht8, a significant difference in cell length was observed between the NILs of QPht/Sl.cau-2D.2. By contrast, there was no difference in cell length between NILs of QPht/Sl.cau-2D.1, indicating that the underlying molecular mechanism for these two QTL may be different. Collectively, these data provide a new example of QTL dissection, and the developed diagnostic markers will be useful in marker-assisted pyramiding of QPht/Sl.cau-2D.1 and/or QPht/Sl.cau-2D.2 with the other genes in wheat breeding.

     

Synthesis of hydroxyethyl starch 200/0.5-loaded albumin nanoparticles: biocompatibility and interaction mechanism

We aimed to synthesize hydroxyethyl starch (HES) 200/0.5-loaded bovine serum albumin nanoparticles (HBNs) and investigate the compatibility and binding mechanism in simulated physiological environments. Here, to elucidate the morphology, biocompatibility, and formation mechanism of HBNs, techniques such as scanning electron microscopy, haemolysis test, fluorescence, and circular dichroism spectroscopy were applied. The thermodynamic parameters at body temperature (ΔS° = −26.7 J·mol⁻¹·K⁻¹, ΔH° = −3.20 × 10⁴ J·mol⁻¹, and ΔG = −2.35 × 10⁴ J·mol⁻¹) showed a 1:1 binding stoichiometry, which was formed by hydrogen bonds and van der Waals interactions. In addition, the conformational analysis showed that the microenvironment of fluorophores was altered with the adaptational protein secondary structural changes. Energy transfer occurred from the fluorophores to HES with a high possibility. All these results provided accurate and complete primary data for demonstrating the interaction mechanisms of HES with BSA, which helps to understand its pharmaceutical effects in blood.     

Whistle characteristics of a newly recorded Indo-Pacific humpback dolphin (Sousa chinensis) population in waters southwest of Hainan Island,China, differ from other humpback dolphin populations

Indo-Pacific humpback dolphins (Sousa chinensis) use whistles to communicate with their conspecifics. Little is known about the acoustic repertoire of Indo-Pacific humpback dolphins in waters southwest of Hainan Island, a newly recorded population in 2014. In this study, whistles of Hainan humpback dolphin population were collected by using autonomous acoustic recorders. The fundamental frequencies and durations of whistles were in ranges of 0.71–21.35 kHz and 0.06–2.22 s, respectively. Significant intraspecific differences in duration and frequency of whistles were found between the Hainan population and the other geographically neighboring populations (in Chinese waters) or the population in Malaysia waters. Compared with other Sousa species, significant interspecific differences were also observed. Based on clustering analysis, the whistle parameters of neighboring populations were likely similar to each other. Significant differences were found between humpback dolphins in waters southwest of Hainan Island and those dolphins in the neighboring areas, supporting the hypothesis that this population may be independent. Ambient noise measurements in waters of Hainan Island, Zhanjiang, and Sanniang Bay showed that humpback dolphin populations may use whistles with longer duration, lower frequency, and fewer inflection points for more effective communication to adapt to a noisier environment.     

小家鼠(Mus musculus)种群动态预测及机制的探讨

我国学者夏武平(1966)用9月铗日捕获率预测东北棕背(鼠平)(Clethrionomys rufocanus)数量以来,严志堂等(1983)应用种群年龄结构的回归方程预测新疆天山北麓农区塔西河地区的小家鼠(Mus musculus)种群密度获初步成功,并根据该文提供的一个改进公式M₁₀=5.60x+5.80(x表示种群年龄的成亚比,M₁₀表示小家鼠10月数量,即年内最高数量),提前11个月预测该地的小家鼠种群最高数量。