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关键词： 实验教学   虚拟仿真   生物化学  

摘要： 生物化学是医学检验技术专业的基础课程,本文在医学检验专业临床模拟实验室概念提出的基础上,构建"虚拟+真实"生物化学实验教学平台,并借助该平台开展生物化学的实验教学,提高生物化学实验教学的效果。

摘要： 《生物化学》是医学专业课程的基础,所以提升生物化学课程的教学效果非常重要。本文总结了医学院校《生物化学》教学的现状,结合本校实际,在《生物化学》课程中开展了混合式教学的方法,并建立过程式课程考核评价体系,旨在提升《生物化学》课程的教学质量和教学效果,为其他相关临床医学专业课程的学习奠定基础。

摘要： 范海延,1974年4月生,汉族,吉林省怀德县人,中共党员,沈阳农业大学教授,博士生导师,生物化学与分子生物学学科带头人,生物科学技术学院副院长,中国植物生理与分子生物学学会理事、辽宁省生命科学学会园艺植物专业委员会主任委员。入选辽宁省"百千万人才工程"百人层次和沈阳市领军人才,曾获第十二届霍英东青年教师奖、辽宁省高等学校优秀人才支持计划、

关键词： 医学生物化学   混合式教学   线上课程   线下面授课程   教学效果  

摘要： 目前,高校医学生物化学课程学时减少严重,而医学执业资格考试涉及的内容逐年增加,线上线下混合式教学在解决"严重缩水的课程学时与丰富的教学内容之间的难题"中起着重要作用。通过实验组和对照组的教学实践比较发现,混合式医学生物化学教学不仅在学生学习成绩、学习兴趣、自学能力等方面与对照组存在差异,而且能增强师生互动性、活跃课堂气氛,教学效果明显优于传统的线下面授课程教学。

关键词： Biochemical findings   Buffalo   Haematology findings   Reticular diaphragmatic hernia   Survival rate  

摘要： This prospective study was conducted on 42 buffaloes diagnosed with reticular diaphragmatic hernia (RDH). The common clinical findings were depressed demeanor, chronic inappetance or anorexia, dehydration, recurrent or persistent tympany, scanty faeces, mushy rumen with normal or increased motility, tachypnea, abdominal distension, and gradual reduction in milk yield. The presence of reticular foreign bodies seemed to be the major predisposing factor. Neutrophil and lymphocyte counts were significantly (p < 0.05) higher and lower than the control values. Total bilirubin, AST, BUN, creatinine glucose, lactate, and fibrinogen were significantly (p < 0.05) higher, and total protein, albumin, albumin-globulin ratio, triglycerides, fibrinogen ratio, sodium chloride, calcium, and phosphorus were significantly (p < 0.05) lower than the control values. The haemoglobin, packed cell volume (PCV), white blood count (WBC), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), cholesterol, and magnesium did not differ significantly (p < 0.05) from control values. RDH can lead to vagal indigestion, and rumen motility will depend upon the stage of vagal indigestion and presence of the reticular adhesions. Out of 26 buffaloes that underwent laparorumenotomy and herniorrhaphy, 14 died within a week, three died after 3–4 weeks, nine recovered within 1–2 weeks, and survived upto full follow-up period of 2 years. The non-survivors had significantly (p < 0.05) higher age, number of calvings, WBC and neutrophil count, PCV, and GGT than the survivors. The hernial ring size ≥ 12.5 cm, with or without reticular adhesions, was associated with poor prognosis. Long time survival rate was 34.6%. It was concluded that the preoperative haematology and rumenotomy findings can be used to predict the prognosis of RDH in buffaloes. © 2021, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.

关键词： Proteins  

摘要： The characterization of protein-protein interactions (PPIs) is an important step toward the development of therapeutic strategies. In this regard, the use of quantum calculations combined with protein fragmentation schemes can offer an opportunity to obtain high quality data and identify key interactions. The mechanistic target of rapamycin (mTOR) protein assembles with partner proteins, such as mLST8, to form two complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), with distinct roles in the coordination of cellular metabolism, growth and survival. Imbalances in this pathway is highly related to cancer risk and recent reports have linked mLST8 upregulation with colon, prostate and liver cancers, demonstrating that the knockout of mLST8 genes in these cells makes them more vulnerable than healthy ones. Such upregulation seems to affect preferentially tumour cells, making this mechanism a pathway for emerging therapeutic strategies. In this work in silico approaches were employed to describe the interaction energy between each amino acid residue at the mTOR-mLST8 interface. PPI calculations were performed at the quantum level, within the density functional theory (DFT) framework, to identify hotspots at the interface side of both proteins. The calculated relative total interaction energy is -195.2 (-179.5) kcal mol(-1) for the crystallographic (MD) structure, with the strongest contribution from a portion at the C-terminal lobe, which is known for forming the binding site for mLST8. Calculated interactions identified the main residues at the mTOR interface as Met2281, Met2271, Glu2285, Glu2288 and His2277, whilst the main residues at the mLST8 interface are Tyr20, Tyr222 and Trp272. This work identifies for the first time, using quantum calculations, the key residues controlling the interaction between mTOR and its partner protein mLST8 and may represent the first step towards designing and probing new compounds to treat cancer through the disruption/modul

关键词： enzyme structure   glycobiology   microbiome   microbiology   pectin methylesterase   Bacteroides thetaiotaomicron   enzyme   BT1017   rhamnogalacturonan II  

摘要： Pectins are a major dietary nutrient source for the human gut microbiota. The prominent gut microbe Bacteroides thetaiotaomicron was recently shown to encode the founding member (BT1017) of a new family of pectin methylesterases essential for the metabolism of the complex pectin rhamnogalacturonan-II (RG-II). However, biochemical and structural knowledge of this family is lacking. Here, we showed that BT1017 is critical for the metabolism of an RG-II-derived oligosaccharide Delta BT1017oligoB generated by a BT1017 deletion mutant (Delta BT1017) during growth on carbohydrate extract from apple juice. Structural analyses of Delta BT1017oligoB using a combination of enzymatic, mass spectrometric, and NMR approaches revealed that it is a bimethylated nonaoligosaccharide (GlcA-beta 1,4-(2-O-Me-Xyl-alpha 1,3)-Fuc-alpha 1,4-(GalA-beta 1,3)-Rha-alpha 1,3-Api-beta 1,2-(Araf-alpha 1,3)-(GalA-alpha 1,4)-GalA) containing components of the RG-II backbone and its side chains. We showed that the catalytic module of BT1017 adopts an alpha/beta-hydrolase fold, consisting of a central twisted 10-stranded beta-sheet sandwiched by several alpha-helices. This constitutes a new fold for pectin methylesterases, which are predominantly right-handed beta-helical proteins. Bioinformatic analyses revealed that the family is dominated by sequences from prominent genera of the human gut microbiota, including Bacteroides and Prevotella. Our re-sults not only highlight the critical role played by this family of enzymes in pectin metabolism but also provide new insights into the molecular basis of the adaptation of B. thetaiotaomicron to the human gut.

关键词： guanylate cyclase (guanylyl cyclase)   retinal degeneration   cyclic GMP (cGMP)   GUCY2D   photoreceptor   vision   calcium-binding proteins   RetGC   GCAP   RD3   signal transduction   stationary night blindness   cone–   rod dystrophy   cyclic nucleotide   retina   neurodegenerative disease   congenital blindness  

摘要： Mutations in the GUCY2D gene coding for the dimeric human retinal membrane guanylyl cyclase (RetGC) isozyme RetGC1 cause various forms of blindness, ranging from rod dysfunction to rod and cone degeneration. We tested how the mutations causing recessive congenital stationary night blindness (CSNB), recessive Leber's congenital amaurosis (LCA1), and dominant cone-rod dystrophy-6 (CORD6) affected RetGC1 activity and regulation by RetGC-activating proteins (GCAPs) and retinal degeneration-3 protein (RD3). CSNB mutations R666W, R761W, and L911F, as well as LCA1 mutations R768W and G982VfsX39, disabled RetGC1 activation by human GCAP1, -2, and -3. The R666W and R761W substitutions compromised binding of GCAP1 with RetGC1 in HEK293 cells. In contrast, G982VfsX39 and L911F RetGC1 retained the ability to bind GCAP1 in cyto but failed to effectively bind RD3. R768W RetGC1 did not bind either GCAP1 or RD3. The co-expression of GUCY2D allelic combinations linked to CSNB did not restore RetGC1 activity in vitro. The CORD6 mutation R838S in the RetGC1 dimerization domain strongly dominated the Ca2+ sensitivity of cyclase regulation by GCAP1 in RetGC1 heterodimer produced by co-expression of WT and the R838S subunits. It required higher Ca2+ concentrations to decelerate GCAP-activated RetGC1 heterodimer-6-fold higher than WT and 2-fold higher than the Ser(838)-harboring homodimer. The heterodimer was also more resistant than homodimers to inhibition by RD3. The observed biochemical changes can explain the dominant CORD6 blindness and recessive LCA1 blindness, both of which affect rods and cones, but they cannot explain the selective loss of rod function in recessive CSNB.

关键词： Filaments   Peptides and proteins   Mixtures   Cell and molecular biology   Post-translational modification  

摘要： The phosphorylated and unphosphorylated forms of tropomyosin Tpm1.1(alpha) are prepared from adult rabbit heart and compared biochemically. Electrophoresis confirms the high level of enrichment of the chromatography fractions and is consistent with a single site of phosphorylation. Covalently bound phosphate groups at position 283 of Tpm1.1(alpha) increase the rate of digestion at Leu-169, suggestive of a conformational rearrangement that extends to the midregion. Such a rearrangement, which is supported by ellipticity measurements between 25 and 42 degrees C, is consistent with a phosphorylation-mediated tightening of the interaction between various myofilament components. In a nonradioactive, co-sedimentation assay [30 mM KCl, 1 mM Mg(II), and 4 degrees C], phosphorylated Tpm1.1(a) displays a higher affinity for F-actin compared to that of the unphosphorylated control (K-d , 0.16 mu M vs 0.26 mu M). Phosphorylation decreases the concentration of thin filaments (pCa 4 plus ATP) required to attain a half-maximal rate of release of product from a pre-power stroke complex [myosin-S1-2-deoxy-3-O-(N-methylanthraniloyl)ADP-P-1], as investigated by double-mixing stopped-flow fluorescence, suggestive of a change in the proportion of active (turned on) and inactive (turned off) conformers, but similar maximum rates of product release are observed with either type of reconstituted thin filament. Phosphorylated thin filaments (pCa 4 and 8) display a higher affinity for myosin-S1(ADP) versus the control scenario without affecting isotherm steepness. Specific activities of ATP and Tpm1.1 (alpha) are determined during an in vitro incubation of rat cardiac tissue [12 day-old, 50% phosphorylated Tpm1.1(alpha)] with [P-32]orthophosphate. The incorporation of an isotope into tropomyosin lags behind that of ATP by a factor of approximately 10, indicating that transfer is a comparatively slow process.