Evaluation of aroma active compounds in <Emphasis Type="Italic">Tuber</Emphasis> fruiting bodies by gas chromatography–olfactometry in combination with aroma reconstitution and omission test

The aroma active compounds of three Tuber fruiting bodies (i.e., Tuber himalayense, Tuber indicum, and Tuber sinense) were firstly systematically evaluated by instrumental gas chromatography–olfactometry combining with quantitative analysis, aroma reconstitution, and omission tests. Twelve aroma active compounds were characterized by aroma extract dilution analysis, and 3-(methylthio) propanal, 3-methylbutanal, and 1-octen-3-ol with the highest flavor dilution (FD) factor (i.e., 1,024–2,048) were suggested as key contributors to the aroma. Odor activity value (OAV) was employed to determine the relative contribution of each compound to the aroma, and the compound with the highest FD factor also had the highest OAV (i.e., 10,234–242,951). Then, the synthetic blends of odorants (aroma reconstitution) were prepared with OAV larger than 15, and their aromas were very similar to the originals. Omission tests were carried out to verify the significance of 3-(methylthio) propanal, 1-octen-3-ol, and 3-methylbutanal as key compounds in the aroma of tested Tuber fruiting bodies.     

Precise Reconstruction of Veins and Bile Ducts in Rat Liver Transplantation

Rat orthotopic liver transplantation (ROLT) remains a technically demanding procedure, especially regarding the reconstruction of the suprahepatic vena cava (SHVC). In this study, a new microsuture technique was developed for anastomosis of the SHVC, and a special single-groove cuff and blade-cut stent were introduced. With these modified techniques, we aimed to make a precise anastomosis of the SHVC and to provide optimal cuffs and stents for the reconstruction of the veins and bile ducts. According to different microsuture techniques for the SHVC and different types of cuffs and stents, three ROLT groups were created to compare the operation times and prognoses. Sham operations were performed as controls in the fourth group. The time expenditures with each step were compared among the transplantation groups. Biochemical parameters were tested at the end of a 1-month observation period. The short- and long-term survival rates of the transplantation groups were recorded and compared. Our new microsuture technique was faster than the conventional continuous suture technique for SHVC anastomosis (P < 0.05). The use of a single-groove cuff for reconstruction of the portal vein and the infrahepatic vena cava shortened the anastomotic time (P < 0.05). The use of blade-cut stents resulted in fewer biliary complications and better survival over the short and long terms (P < 0.05). Our new microsuture technique and the single-groove cuffs proved to be a precise method for venous reconstruction which shortened the anhepatic time and the anastomotic time significantly. The blade-cut stents apparently reduced the incidence of biliary complications. In summary, with this precise microsuture technique and delicate cuffs and stents, excellent long-term survival can be achieved easily and stably for ROLT.     

转化生长因子-β对基质金属蛋白酶及其组织抑制因子调控的研究进展

基质金属蛋白酶 (MMPs) 及其组织抑制因子 (TIMPs) 参与调控胞外基质 (ECM) 的降解与重建,二者的协同作用以及表达的动态平衡保证组织的生理/病理形态结构建成,并完成生长、分化、维持、降解的往复周期. 转化生长因子-β(TGF-β)通过对MMPs和TIMPs家族成员因细胞类型而异的基因表达调控作用,表现出调节ECM重建的生物学效应. TGF-β可通过激活Smad通路、促分裂原活化蛋白激酶 (MAPK) 通路,以及刺激激活蛋白-1(AP-1)复合体的形成,完成对MMPs和TIMPs基因表达的调控功能.     

0.21nm分辨率BO-(L-精氨酸)牛胰岛素晶体结构研究

应用差值Fourier技术,立体化学最小二乘技术和XPLOR程序并辅以电子密度图的人工拟合,以三方二锌猪胰岛素模型为起点,解析了0.21nm分辨率BO-(L-精氨酸)牛胰岛素的晶体结构,最终R因子为18.2%,与标准键长与键角的均方根偏差分别为0.0022nm和 4.3°.从电子密度图与模型的拟合来看,独立区两个分子中B链N端加长的L-精氨酸清晰可见.相对于三方二锌猪胰岛素分子,B链N端晶体学微环境发生了变化.     

A modified cornish pasty method for ex ovo culture of the chick embryo development

Chick embryos grown in ex ovo culture by the modified Cornish pasty method reported in Nagai, Lin and Sheng in this issue.     

帕金森病的临床治疗概况

帕金森病(Parkinson's disease, PD),在医学上称为"原发性震颤麻痹",又称"震颤麻痹",是一种中枢神经系统变性疾病,主要是因位于中脑部位"黑质"中的多巴胺(DA)能神经元病理性改变后,多巴胺的合成减少,对与其功能相互拮抗的乙酰胆碱的抑制功能降低,则乙酰胆碱的兴奋作用相对增强。两者失衡的结果便出现了"震颤麻痹"。本综述先从PD发病机制方向总结归纳目前临床常用的西医药物(包括左旋多巴、DA降解酶抑制剂、DA受体激动剂、抗胆碱能药物)、基因治疗靶点、手术治疗(脑深部电刺激术)及物理疗法,又从中医角度整体介绍了目前中医中药治疗以及针灸治疗等。因PD对患者的日常生活及身心健康造成了严重影响,我们希望通过本综述为PD综合治疗提供更广阔的临床思路及更好的方案。     

Primary structure and expression of a sodium channel characteristic of denervated and immature rat skeletal muscle

The alpha subunit of a voltage-sensitive sodium channel characteristic of denervated rat skeletal muscle was cloned and characterized. The cDNA encodes a 2018 amino acid protein (SkM2) that is homologous to other recently cloned sodium channels, including a tetrodotoxin (TTX)-sensitive sodium channel from rat skeletal muscle (SkM1). The SkM2 protein is no more homologous to SkM1 than to the rat brain sodium channels and differs notably from SkM1 in having a longer cytoplasmic loop joining domains 1 and 2. Steady-state mRNA levels for SkM1 and SkM2 are regulated differently during development and following denervation: the SkM2 mRNA level is highest in early development, when TTX-insensitive channels predominate, but declines rapidly with age as SkM1 mRNA increases; SkM2 mRNA is not detectable in normally innervated adult skeletal muscle but increases greater than 100-fold after denervation; rat cardiac muscle has abundant SkM2 mRNA but no detectable SkM1 message. These findings suggest that SkM2 is a TTX-insensitive sodium channel expressed in both skeletal and cardiac muscle.     

The C9orf72-SMCR8-WDR41 complex is a GAP for small GTPases

ABSTRACT

Massive expansions of the hexanucleotide in C9orf72 are the primary genetic origins of familial amyotrophic lateral sclerosis (ALS) and frontal temporal dementia (FTD). Current studies have found that this repeat sequence participates in the disease process by producing neurotoxic substances and reducing the level of C9orf72 protein; however, the progress in the functional study of C9orf72 is slow. Recently, a stable complex, consisting of C9orf72, SMCR8, and WDR41, has been implicated in regulating membrane trafficking and macroautophagy. We reported the cryo-electron microscopy (cryo-EM) structure of the C9orf72-SMCR8-WDR41 complex (CSW complex), unveiling that the CSW complex is a dimer of heterotrimers. Intriguingly, in the heterotrimer of the C9orf72-SMCR8-WDR41, C9orf72 interacts with SMCR8 in a manner similar to the FLCN-FNIP2 complex. Nevertheless, WDR41 is connected to the DENN domain of SMCR8 through its N-terminal β-strand and C-terminal helix but does not directly interact with C9orf72. Notably, the C9orf72-SMCR8 complex was demonstrated to act as a GAP for RAB8A and RAB11A in vitro.