Complete mitochondrial genome of Coelomactra antiquata (Mollusca: Bivalvia): The first representative from the family Mactridae with novel gene order and unusual tandem repeats

The complete mitochondrial genome plays an important role in the accurate inference of phylogenetic relationships among metazoans. Mactridae, also known as trough shells or duck clams, is an important family of marine bivalve clams in the order Veneroida. Here we present the complete mitochondrial genome sequence of the Xishishe Coelomactra antiquata (Mollusca: Bivalvia), which is the first representative from the family Mactridae. The mitochondrial genome of C. antiquata is of 17,384 bp in length, and encodes 35 genes, including 12 protein-coding, 21 transfer RNA, and 2 ribosomal RNA genes. Compared with the typical gene content of animal mitochondrial genomes, atp8 and tRNAS₂ are missing. Gene order of the mitochondrial genome of C. antiquata is unique compared with others from Veneroida. In the mitochondrial genome of the C. antiquata, a total of 2189 bp of non-coding nucleotides are scattered among 26 non-coding regions. The largest non-coding region contains one section of tandem repeats (99 bp × 11), which is the second largest tandem repeats found in the mitochondrial genomes from Veneroida. The phylogenetic trees based on mitochondrial genomes support the monophyly of Veneridae and Lucinidae, and the relationship at the family level: ((Veneridae + Mactridae) + (Cardiidae + Solecurtidae)) + Lucinidae. The phylogenetic result is consistent with the morphological classification. Meanwhile, bootstrap values are very high (BP = 94–100), suggesting that the evolutionary relationship based on mitochondrial genomes is very reliable.     

Analysis of the Relationships between Clinicopathologic Factors and Survival in Gallbladder Cancer following Surgical Resection with Curative Intent

Background

This study elucidated the relationships between various clinicopathologic factors and the outcome of patients with gallbladder cancer (GBC) treated by surgical resection with curative intent.

Methods

Between January 2003 and January 2011, 76 patients with GBC underwent surgical resection with curative intent at our department. We then conducted a retrospective analysis of clinicopathologic data. Fourteen clinicopathological variables were selected for univariate and multivariate analysis to evaluate their influence on the outcome.

Results

The actuarial 1-, 3-, and 5-year survival rates in the 76 resected cases were 56.6%, 32.7%, and 23.8%, respectively. The univariate analysis revealed that curative resection (P<0.001), lymph node metastasis (P<0.001), AJCC stage (P = 0.030), tumor location (P = 0.008), histologic differentiation (P = 0.028), intraoperative blood loss (P = 0.011), and preoperative jaundice (P = 0.012) were significant risk factors for survival. Multivariate analysis revealed that noncurative resection and tumor location on gallbladder neck were significant risk factors for poor outcome. Among jaundiced patients, we discovered that gallbladder carcinoma with tumor thrombus in common bile duct (CBD) was very rare but with relatively special clinical manifestation and characteristic radiography manifestation. The prognosis of gallbladder carcinoma with tumor thrombus in CBD after surgical procedure was apparently better than gallbladder carcinoma with invasion of hilar tissues.

Conclusions

Curative surgical resection remains the only effective approach to the treatment of GBC. This series confirm that jaundice is a poor prognostic factor. However, the presence of jaundice does not preclude resection, especially in highly selected patients (when R0 resection is achievable). Gallbladder carcinoma with tumor thrombus in CBD has special clinical characteristics, which need to be awared by radiologists and clinicians.     

中国被毛孢和蝙蝠蛾拟青霉小鼠免疫功能调节作用的比较

目的观察中国被毛孢和蝙蝠蛾拟青霉对小鼠免疫功能的影响。方法分别给予中国被毛孢和蝙蝠蛾拟青霉后,测定观察对小鼠碳粒廓清功能、迟发性变态反应、溶血素抗体、淋巴细胞增殖和NK细胞活性等的影响。结果3．0g／kg中国被毛孢和蝙蝠蛾拟青霉可显著提高小鼠吞噬指数和半数溶血值（P〈0．01）、显著提高T、B淋巴细胞增殖能力（P〈0．01,P〈0．05）、显著提高NK细胞活性（P〈0．05）,0．5～1．5g／kg中国被毛孢都能显著抑制小鼠耳廓肿胀（P〈0．01,P〈0．05）,同时还能抑制脾脏和胸腺增大（P〈0．01,P〈0．05）。结论中国被毛孢和蝙蝠蛾拟青霉均具有免疫调节作用,而中国被毛孢免疫抑制及增强天然免疫系统作用要优于蝙蝠蛾拟青霉,而对适应性免疫系统增强作用蝙蝠蛾拟青霉优于中国被毛孢。     

ORP2 Delivers Cholesterol to the Plasma Membrane in Exchange for Phosphatidylinositol 4, 5-Bisphosphate (PI(4,5)P2)

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思维导图模型在分子生物学教学环节中的应用

“分子生物学”是中医院校为医学生开设的专业基础课,课程特征是逻辑性强、核心概念多、生物过程复杂。为加强学生对教学内容的理解和应用,培养学生高阶思维能力,我们探索了将思维导图模型融入教学的课前、课中、课后3个环节中：通过“九宫分析法”模型提出教学问题、“六顶思考帽”模型创新课堂教学及“金字塔原理”模型复盘教学内容帮助学生构建思考力闭环。以相关知识内联和发散为指导思想,通过思维可视化加强学生对知识点的理解。根据问卷调查,有91%的同学认为思维导图模型的应用是一种有效的教学方法,可实现提高课堂效率、提升教学效果的目的,有76%的同学尝试将这种方法用于其他课程的学习,认为对个体思考力的提高有帮助。据此,思维导图模型应用于教学环节对培养学生高阶思维能力有重要意义,为高校课程教学提供一种新思路。     

GHR is involved in gastric cell growth and apoptosis via PI3K/AKT signalling

Growth hormone receptor (GHR), the cognate receptor of growth hormone (GH), is a membrane bound receptor that belongs to the class I cytokine receptor superfamily. GH binding GHR induces cell differentiation and maturation, initiates the anabolism inside the cells and promotes cell proliferation. Recently, GHR has been reported to be associated with various types of cancer. However, the underlying mechanism of GHR in gastric cancer has not been defined. Our results showed that silence of GHR inhibited the growth of SGC-7901 and MGC-803 cells, and tumour development in mouse xenograft model. Flow cytometry showed that GHR knockout significantly stimulated gastric cancer cell apoptosis and caused G1 cell cycle arrest, which was also verified by Western blot that GHR deficiency induced the protein level of cleaved-PARP, a valuable marker of apoptosis. In addition, GHR deficiency inhibited the activation of PI3K/AKT signalling pathway. On the basis of the results, that GHR regulates gastric cancer cell growth and apoptosis through controlling G1 cell cycle progression via mediating PI3K/AKT signalling pathway. These findings provide a novel understanding for the role of GHR in gastric cancer.     

HPLC‐Fluorescence Method for the Enantioselective Analysis of Propranolol in Rat Serum Using Immobilized Polysaccharide‐Based Chiral Stationary Phase

A stereoselective high‐performance liquid chromatographic (HPLC) method was developed and validated to determine S‐(?)‐ and R‐(+)‐propranolol in rat serum. Enantiomeric resolution was achieved on cellulose tris(3,5‐dimethylphenylcarbamate) immobilized onto spherical porous silica chiral stationary phase (CSP) known as Chiralpak IB. A simple analytical method was validated using a mobile phase consisted of n‐hexane‐ethanol‐triethylamine (95:5:0.4%, v/v/v) at a flow rate of 0.6 mL min^‐1 and fluorescence detection set at excitation/emission wavelengths 290/375 nm. The calibration curves were linear over the range of 10–400 ng mL^‐1 (R = 0.999) for each enantiomer with a detection limit of 3 ng mL^‐1. The proposed method was validated in compliance with ICH guidelines in terms of linearity, accuracy, precision, limits of detection and quantitation, and other aspects of analytical validation. Actual quantification could be made for propranolol isomers in serum obtained from rats that had been intraperitoneally (i.p.) administered a single dose of the drug. The proposed method established in this study is simple and sensitive enough to be adopted in the fields of clinical and forensic toxicology. Molecular modeling studies including energy minimization and docking studies were first performed to illustrate the mechanism by which the active enantiomer binds to the β‐adrenergic receptor and second to find a suitable interpretation of how both enantiomers are interacting with cellulose tris(3,5‐dimethylphenylcarbamate) CSP during the process of resolution. The latter interaction was demonstrated by calculating the binding affinities and interaction distances between propranolol enantiomers and chiral selector. Chirality 26:194–199, 2014. © 2014 Wiley Periodicals, Inc.     

Hydrogen sulfide is involved in maintaining ion homeostasis via regulating plasma membrane Na+/H+ antiporter system in the hydrogen peroxide-dependent manner in salt-stress Arabidopsis thaliana root

Hydrogen sulfide (H₂S) and hydrogen peroxide (H₂O₂) function as the signaling molecules in plants responding to salt stresses. The present study presents a signaling network involving H₂S and H₂O₂ in salt resistance pathway of the Arabidopsis root. Arabidopsis roots were sensitive to 100 mM NaCl treatment, which displayed a great increase in electrolyte leakage (EL) and Na⁺/K⁺ ratio under salt stress. The treatment of H₂S donors sodium hydrosulfide (NaHS) enhanced the salt tolerance by maintaining a lower Na⁺/K⁺ ratio. In addition, the inhibition of root growth under salt stress was removed by H₂S. Further studies indicated that H₂O₂ was involved in H₂S-induced salt tolerance pathway. H₂S induced the production of the endogenous H₂O₂ via regulating the activities of glucose-6-phosphate dehydrogenase (G6PDH) and plasma membrane (PM) NADPH oxidase, with the treatment with dimethylthiourea (DMTU, an ROS scavenger), diphenylene iodonium (DPI, a PM NADPH oxidase inhibitor), or glycerol (G6PDH inhibitor) removing the effect of H₂S. Treatment with amiloride (an inhibitor of PM Na⁺/H⁺ antiporter) and vanadate (an inhibitor of PM H⁺-ATPase) also inhibited the activity of H₂S on Na⁺/K⁺ ratio. Through an analysis of quantitative real-time polymerase chain reaction and Western blot, we found that H₂S promoted the genes expression and the phosphorylation level of PM H⁺-ATPase and Na⁺/H⁺ antiporter protein level. However, when the endogenous H₂O₂ level was inhibited by DPI or DMTU, the effect of H₂S on the PM Na⁺/H⁺ antiporter system was removed. Taken together, H₂S maintains ion homeostasis in the H₂O₂-dependent manner in salt-stress Arabidopsis root.