Ethanol stimulates triglyceride synthesis by the intestine

In vivo ethanol given acutely or chronically by two dietary means resulted in significant increases in [1-(14)C]palmitate incorporation into triglyceride by intestinal slices or microsomes derived from intestinal slices. In vitro, 2.6 percent ethanol, an amount comparable to that found in t..e intestinal lumen of social drinkers, also resulted in significant increases in [1-(14)C]palmitate incorporation into triglyceride. Pyrazole, an inhibitor of alcohol dehydrogenase, diminished the stimulatory effect of ethanol both in vivo and in vitro. These data may provide a new insight into the effects of alcohol, and specifically on the possible contribution of intestinal triglyceride synthesis to alcoholic hyperlipemia and the alcohol-induced fatty liver.     

拟南芥花粉体外和体内2种萌发差异的比较研究

[目的]比较拟南芥花粉体外和体内2种萌发的差异。[方法]以模式植物拟南芥作为研究对象,采用荧光显微镜观察比较2种体外萌发培养基的萌发率差异并比较体外萌发率和体内萌发率的差异。[结果]花粉在固体培养基上的萌发率平均为51.01%,而在液体培养基上萌发率平均为83.97%;在体外,液体萌发培养基优于固体萌发培养基,液体培养基萌发率较固体培养基萌发率高,稳定;体内萌发较体外萌发稳定,萌发率高,平均萌发率为94.00%。[结论]研究结果为检测花粉活力提供了一个有效的检测标准,为拟南芥花粉的生物学研究提供理论与方法。     

Biosynthesis of chick hemoglobins

In vivo studies of the biosynthesis of chick hemoglobins 1 and 2 showed an over-all higher incorporation of glycine-2-C(14), valine-4-C(14), valine-1-C(14), leucine-G-C(14), and histidine-(2-ring)-C(14) in hemoglobin 2; in vitro studies made with intact nucleated chick erythrocytes showed the higher incorporation of glycine-2-C(14), valine-1-C(14), and histidine-(2-ring)-C(14) in hemoglobin 1. Hybridization of chick hemoglobins produced an electrophoretically distinguishable new component.     

鼻咽癌患者与不同IgA/VCA抗体滴度者外周血单个核细胞对EB病毒感染的早期免疫反应

本文用本室建立的EB病毒(EBV)体外感染外周血单个核细胞(PBMC)早期反应综合检测观察系统,测定了鼻咽癌(NPC)患者、IgA/VCA高滴度者、低滴度和阴性者3组人的PBMC体外感染EBV的早期免疫反应。发现在EBV感染PBMC早期,NPC组的EBNA阳性细胞数、~3H-TdR掺入量和免疫球蛋白(IgG、IgG、IgG)分泌量最低,IgA/VCA低滴度和阴性组最高,两组间所有指标差异均有显著或非常显著性,而IgA/VCA高滴度组的多数指标与NPC组接近.结果表明,在EBV体外感染PBMC所引起的早期免疫反应中,NPC患体者和IgA/VCA高滴度者EBV活化的B细胞功能较IgA/VCA低滴度和阴性者降低.这对了解NPC发生发展过程中EBV感染活化B细胞的功能在体内外变化的关系方面具有一定意义.     

小鼠子宫内膜诱导蜕膜化的研究

[目的]建立体内和体外诱导小鼠子宫内膜蜕膜化的方法。[方法]利用假孕小鼠子宫角注油和激素处理体外分离的4周龄小鼠子宫内膜基质细胞进行诱导蜕膜化,通过半定量PCR和实时定量PCR检测蜕膜化标志分子蜕膜/滋养层泌乳雌激素相关蛋白。[结果]假孕第4天子宫角注油和雌激素与孕酮联合处理小鼠子宫内膜基质细胞都可显著提高蜕膜化标志分子的mRNA水平,可诱导产生蜕膜化。[结论]建立了体内和体外诱导蜕膜化的方法,为验证小鼠蜕膜化芯片奠定了基础。     

Experience strengthening transmission by driving AMPA receptors into synapses

The mechanisms underlying experience-dependent plasticity in the brain may depend on the AMPA subclass of glutamate receptors (AMPA-Rs). We examined the trafficking of AMPA-Rs into synapses in the developing rat barrel cortex. In vivo gene delivery was combined with in vitro recordings to show that experience drives recombinant GluR1, an AMPA-R subunit, into synapses formed between layer 4 and layer 2/3 neurons. Moreover, expression of the GluR1 cytoplasmic tail, a construct that inhibits synaptic delivery of endogenous AMPA-Rs during long-term potentiation, blocked experience-driven synaptic potentiation. In general, synaptic incorporation of AMPA-Rs in vivo conforms to rules identified in vitro and contributes to plasticity driven by natural stimuli in the mammalian brain.     

酶解去除抗原蛋白饲料对仔猪生产性能的影响

分别选用18日龄和24日龄断奶的长太杂交仔猪,采用单因子试验设计,分两个试验研究了复合酶体外预处理、不预处理去除抗原蛋白的豆粕和生大豆不同类型日粮对不同断奶日龄仔猪生产性能和生化参数的影响。结果表明:酶解预处理能有效去除豆粕抗原蛋白,极显著提高18日龄断奶仔猪生长速度和饲料利用效率(P<0 01),豆粕加酶预处理提高仔猪免疫力;24日龄断奶仔猪加酶去除抗原蛋白豆粕饲料其生产性能显著优于豆粕对照组(P<0 05),利用体外酶解预处理去除抗原蛋白豆粕饲料显著提高饲料利用率,饲料的品质越好,动物年龄越大,加酶去除豆粕抗原蛋白不同处理方式对仔猪生产性能的影响差异不显著(P>0 05);生大豆加酶预处理不宜作为18日龄断奶仔猪饲料的唯一蛋白源补充料;18日龄和24日龄断奶仔猪用酶解预处理大豆蛋白作单一蛋白补充料均不产生过敏反应。酶解预处理去除抗原蛋白是一种合理利用大豆产品资源的有效方法。     

人参须超微粉水提液体内外抗肿瘤药理作用研究

[目的]观察人参须超微粉水提液体内外抗肿瘤活性及其对免疫器官的影响。[方法]用MTT法观察人参须超微粉水提液对CNE-2Z瘤株的体外抗肿瘤作用;以荷瘤小鼠瘤重、抑瘤率为考察指标,检测人参须超微粉水提液对小鼠移植性肿瘤S180的抑制作用;以胸腺重量、肝脏重量、脾脏重量、白细胞数等为考察指标,观察人参须超微粉水提液对免疫器官的影响。[结果]人参须超微粉水提液对CNE-2Z瘤株有显著的体外抗肿瘤作用,对荷瘤小鼠S180在体内也有抗肿瘤活性。[结论]人参须超微粉水提液具有一定的体内外抗肿瘤活性,没有发现对免疫功能有明显抑制作用。     

水分胁迫下钙对甘蔗幼苗抗氧化酶活性的影响

选取甘蔗福农95-1702为材料,结合钙离子螯合剂EGTA预处理,对水分胁迫下Ca2 与甘蔗幼苗抗氧化酶类活性的关系进行研究,探讨逆境信号转导第二信使Ca2 在甘蔗抗旱性中的作用。结果表明,1￣3mmol/L的EGTA预处理对正常生长条件下甘蔗幼苗的相对生长率、可溶性蛋白含量及抗氧化酶活性均无显著影响。但30%PEG处理下,1￣3mmol/L的EGTA预处理降低了甘蔗幼苗的相对生长量,加剧了可溶性蛋白含量的下降:在处理的24小时,处理1E D(1mmol/LEGTA 30%PEG)及3E D(3mmol/LEGTA 30%PEG)中的可溶性蛋白含量分别比处理D(30%PEG)降低了40.2%和54.3%。同时,EGTA预处理抑制了PEG胁迫下超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的升高,加剧了过氧化氢酶(CAT)活性的降低:在处理的24小时,处理1E D及3E D中的SOD活性分别比处理D降低了26.5%和29.9%;而POD活性则比处理D分别降低了31.3%和23.2%;处理3E D的CAT酶活性比处理D降低了27.2%。这些结果暗示Ca2 可能参与了水分胁迫下甘蔗幼苗抗氧化酶系统的调节,Ca2 信号和活性氧(ROS)所介导的信号转导途径存在交叉互作。     

甲硫基腺苷对小鼠黑色素瘤B16F10细胞系的抑制作用

应用细胞培养技术研究了甲硫基腺苷对小鼠黑色素瘤B16F10细胞系体外增殖和体内增长的抑制作用。结果表明:甲硫基腺苷抑制了小鼠黑色素瘤B16F10细胞系的体外增殖(IC50为10μmol/L,P<0.01)和体内增长(抑瘤率为30.8%,P<0.05)。     

Major urinary protein complex of normal mice: origin

Mouse serum contains protein having the same charge density and molecular size as the major urinary protein complex of mice. Mouse liver (but not eight other tissues examined) incorporated amino acids labeled with carbon-14 into the complex in vitro. The degree of incorporation was greater in livers from males than from females, and was internmediate in livers from females treated with testosterone.     

瞬时弹射式蒸汽爆破对玉米秸秆微贮营养成分和牛瘤胃营养物质消失率的影响

为研究干黄玉米秸秆经瞬时弹射式蒸汽爆破(ICSE)预处理后微贮产品营养成分及奶牛瘤胃营养物质消失率的变化规律,使用气压2.0MPa保持150s、气压1.8MPa保持200s和气压1.2MPa保持200s3组预处理条件,每组4个重复,用ICSE技术对玉米秸秆进行预处理,并接种乳酸菌在厌氧条件下微贮60d;微贮后的秸秆产品进行氨基酸成分分析、主要营养成分测定和真菌毒素含量检测;采用尼龙袋法测定并评价微贮秸秆产品的奶牛瘤胃干物质消失率。结果表明:1.8 MPa 200s预处理后微贮饲料的品质最佳,其中粗蛋白质含量10.85%,是2.0MPa 150s预处理组(5.99%)近两倍(P0.05),高于对照组(8.38%)和1.2 MPa 200s预处理组(10.46%);1.8MPa 200s预处理组的奶牛瘤胃干物质消失率也最高,达到77.36%,极显著高于对照组和1.2MPa 200s预处理组(P0.01),显著高于2.0MPa 150s预处理组(P0.05)。综上,瞬时弹射式蒸汽爆破预处理结合乳酸菌微贮后的干黄玉米秸秆品质较好,在反刍动物养殖中具有一定应用价值。     

Enhanced CpG mutability and tumorigenesis in MBD4-deficient mice

The mammalian protein MBD4 contains a methyl-CpG binding domain and can enzymatically remove thymine (T) or uracil (U) from a mismatched CpG site in vitro. These properties suggest that MBD4 might function in vivo to minimize the mutability of 5-methylcytosine by removing its deamination product from DNA. We tested this hypothesis by analyzing Mbd4-/- mice and found that the frequency of of C --> T transitions at CpG sites was increased by a factor of three. On a cancer-susceptible Apc(Min/+) background, Mbd4-/- mice showed accelerated tumor formation with CpG --> TpG mutations in the Apc gene. Thus MBD4 suppresses CpG mutability and tumorigenesis in vivo.     

Association of human papillomavirus types 16 and 18 E6 proteins with p53

Human papillomavirus type 16 (HPV-16) is a DNA tumor virus that is associated with human anogenital cancers and encodes two transforming proteins, E6 and E7. The E7 protein has been shown to bind to the retinoblastoma tumor suppressor gene product, pRB. This study shows that the E6 protein of HPV-16 is capable of binding to the cellular p53 protein. The ability of the E6 proteins from different human papillomaviruses to form complexes with p53 was assayed and found to correlate with the in vivo clinical behavior and the in vitro transforming activity of these different papillomaviruses. The wild-type p53 protein has tumor suppressor properties and has also been found in association with large T antigen and the E1B 55-kilodalton protein in cells transformed by SV40 and by adenovirus type 5, respectively, providing further evidence that the human papillomaviruses, the adenoviruses, and SV40 may effect similar cellular pathways in transformation.     

山羊转基因克隆胚在体内和体外发育的研究

探讨了体内/外成熟卵母细胞、体内/外培养系统、输卵管液和输卵管上皮细胞共培养系统对转基因克隆胚发育的影响。结果表明:体内/外成熟卵母细胞对转基因克隆胚各阶段发育率无显著影响。体内/外培养系统中,转基因克隆胚2～3-细胞、4-细胞、8-细胞发育率差异不显著;16-细胞和桑/囊胚发育率差异显著。对照组和20%输卵管液中,转基因克隆胚2～3-细胞、4-细胞、8-细胞发育率均显著高于50%输卵管液;在20%输卵管液中16-细胞的发育率显著高于对照组和50%输卵管液。转基因克隆胚在输卵管上皮细胞共培养系统和SOF培养系统中培养,2～3-细胞和4-细胞发育率无显著差异;8-细胞、16-细胞和桑/囊胚的发育率差异显著。     

Expanding the genetic code of Escherichia coli

A unique transfer RNA (tRNA)/aminoacyl-tRNA synthetase pair has been generated that expands the number of genetically encoded amino acids in Escherichia coli. When introduced into E. coli, this pair leads to the in vivo incorporation of the synthetic amino acid O-methyl-l-tyrosine into protein in response to an amber nonsense codon. The fidelity of translation is greater than 99%, as determined by analysis of dihydrofolate reductase containing the unnatural amino acid. This approach should provide a general method for increasing the genetic repertoire of living cells to include a variety of amino acids with novel structural, chemical, and physical properties not found in the common 20 amino acids.     

Antimalarials: effects on in vivo and in vitro protein synthesis

The antimalarials quinine, chloroquine, primaquine, and quinacrine inhibited the uptake and incorporation of amino acids in vivo, but these drugs had considerably less effect on cell-free protein synthesis. The results indicate that the primary effect of the four drugs on protein synthesis is blocking of amino acid uptake by the cells.     

Sparing of the brain in neonatal undernutrition: amino acid transport and incorporation into brain and muscle

Rates of tyrosine and lysine transport and incorporation into protein were measured in control and undernourished weanling rats. Undernutrition was induced by feeding lactating dams a low protein diet (12 percent casein) from birth to day 21. At weaning, body and brain weights of undernourished rats were 50 percent and 88 percent, respectively, of control values. Lysine and tyrosine transport rates into skeletal muscle were reduced by over 75 percent, more than twice the reduction seen in brain. Rates of amino acid incorporation into muscle protein were reduced by approximately 50 percent; the change in rate of incorporation into brain protein was not statistically significant. These data indicate that, in spite of marked retardation of amino acid transport into brain, the brain seems fully capable of maintaining normal rates of protein synthesis.     

Protein-synthesizing activity of the anucleate polar lobe of the mud snail Ilyanassa obsoleta

Polar lobes of eggs of the mud snail Ilyanassa obsoleta, detached at the "trefoil" stage of the first cleavage, are capable of incorporating labeled amino acid into protein. The rate of incorporation per unit volume is about half that of the whole egg. The ability to incorporate at a similar rate persists for at least 24 hours after isolation. The sum of the incorporation of isolated lobes and lobeless fragments approximates that of the whole egg. The results extend to this material (the anucleate polar lobe) evidence for long-lived messenger RNA. They suggest also that the demonstrated morphogenetic influence of the lobe, which is exerted primarily during cleavage, may be correlated with its ability to synthesize protein.