Role of calcium in differentiation of murine erythroleu-kemia cells

Calcium plays a crucial role in the normal and abnomal cell metabolism.The role of calcium in the differentiation process of murine erythroleukemia cells(MELC)remains controversial.Here,based upon quantitative measurement of fluorescence in single cells,a method was developed to investigate the intracellular free calcium[Ca^2 ]i concentration and DNA contents simultaneously,by employing the fluorescent probe,fluo-3 acetoxymethyl ester and DNA dye Hoechst 33342.During MELC differentiation.[Ca^2 ]i concentration incresed.We also demonstrated that calcium ionophore,A23187,enhanced the HMB-induced MELC differentiation,while verapamil,an inhibitor of calcuim uptake,slightly reduced differentiation.These results suggested that an increase in the [Ca^2 ]i level was an essential step in HMBA-induced MELC differentiation.     

变黄黑文衣,中国黑文衣属地衣一新记录种

通过对文字衣科黑文衣属形态学、解剖学、化学与分子生物学的研究,发现中国新记录种1种,即变黄黑文衣(Phaeographis flavescens Dal-Forno&Eliasaro),该种主要特征为地衣体壳状,表面浅黄绿色,无光泽,光滑;子囊盘弯曲,多分支,聚生于假子座中;盘缘黑色,相邻线盘之间有小缝隙,盘面较平坦,黑色,覆有白色粉霜;子囊层无色透明,侧丝顶端分支;子囊含8个子囊孢子;子囊孢子褐色,横隔透镜型,(4～)6胞室,大小19～25.5μm×6～7μm,I+紫红色。该种分布于云南和福建,该研究丰富了对中国黑文衣属物种组成与分布的认知。     

六种鼠苹果酸脱氢酶,血浆蛋白质和血红蛋白的变异分析

本文分析了家鼠属（Ｒａｔｔｕｓ）４种鼠和姬鼠属（Ａｐｏｄｅｍｕｓ）２种鼠的苹果酸脱氢酶、血浆中β１区和β２区蛋白质、血浆清蛋白、前清蛋白以及红细胞中血红蛋白的变异。结果表明,ＭＤＨ在进化上是比较保守的,其中ＭＤＨｍ和ＭＤＨｓ２带在各鼠间位于同一泳动线上,仅ＭＤＨｓ１带的泳动速度出现属间和种间的微小差异;血浆中β１区和β２区的蛋白质带、清蛋白带以及前清蛋白带各鼠间出现明显的变异,表现为黑线姬鼠和社鼠在β１区出现２种多态型区带,褐家鼠在β２区也有２种多态型带;各鼠间的血红蛋白变异比较明显,主要表现在区带数和主成分的泳动度显著不同,而且社鼠的Ｈｂ出现３种多态型,黄毛鼠出现２种多态型,其余各鼠的Ｈｂ皆为单态性。上述１６项生化特性按相似和相异进行配对比较,初步表明黄毛鼠与褐家鼠亲缘上比较相近,白腹巨鼠要比其他３种鼠亲缘上更接近于黑线姬鼠,而社鼠与白腹巨鼠之间进化分歧相对地较大。     

板齿鼠种群数量中长期预测的时间序列模型

本文利用时间序列方法（三次指数平滑法）,并结合季节指数法,建立了板齿鼠种群数量中长期预测（６个月～１年）的时间序列模型,依据１９９１年１１月～１９９３年１２月在广东省博罗县石湾镇里波水管理区对板齿鼠种群数量动态的调查数据,分别预测了１９９４年和１９９５年板齿鼠种群数量的发生,预测准确率达到了８６．５６％。     

单爪螯蜂属二新种：膜翅目：螯蜂科;单爪螯蜂亚科

本文记述单爪螯蜂属二新种;梳垫单瓜螯蜂Ａｎｔｅｏｎ ｐｅｃｔｉｎａｒｏｌｉｕｍ,ｓｐ．ｎｏｖ。和滑盾单爪螯蜂Ａｎｔｅｏｎ ｂｌａｎｄｕｓｃｕｔｕｍ,ｓｐ．ｎｏｖ。新种的模式标本保存在浙江农业大学植物保护系。     

远交系小鼠胚胎干细胞系的建立及嵌合鼠的获得

ＥＳ细胞（ＥｍｂｒｙｏｎｉｃＳｔｅｍＣｅｌｌｓ）是来源于小鼠早期胚胎的多潜能干细胞,它可以在体外大量培养。并以单细胞的形式注射到早期胚胎里,发育为嵌合体。到目前为止,通常使用的１２９小鼠品系是来源于近交系（ｉｎｂｒｅｄ）小鼠的胚胎．与之相比,远交系小鼠应当具有较强的生命力和抗病能力。曾有人报道过建成了远交系小鼠胚胎干细胞系,但是尚没有见到获得嵌合鼠的报道。有人甚至认为：由于不同品系小鼠所具有的遗传背景不同,有的小鼠不能建成ＥＳ细胞系。最近,本实验室在这方面做了有益的探索,成功地建成了远交系小鼠胚胎干细胞系,并在这里报导首例用远交系小鼠胚胎干细胞系培育成功嵌合体小鼠。采用源于Ｓｗｉｓｓ小鼠远交群的昆明（ＫＭ）品系小鼠囊胚建成了三个小鼠胚胎干细胞系（ＫＥ１．ＫＥ２．ＫＥ５）。核型正常率均达到７０％以上。自第八代起分批冻存,复苏后,培养至第１２代,消化成单细胞,通过囊胚显微注射,将其注射到６１５品系小鼠胚胎。在幸存的幼鼠中获得了一只来源于ＫＥ１细胞的嵌合鼠（Ｔａｂｌｅ１）．其毛色表现为受体鼠（６１５）的白色中嵌合有供体鼠（ＫＭ）的黑褐色（ＰｌａｔｅＩ－Ａ）．嵌合鼠与受体鼠的杂交后代鼠中仍然出现了受体鼠的毛色类型（     

Desaturation and oxygenation of 1,2-dihydronaphthalene by toluene and naphthalene dioxygenase.

Bacterial strains expressing toluene and naphthalene dioxygenase were used to examine the sequence of reactions involved in the oxidation of 1,2-dihydronaphthalene. Toluene dioxygenase of Pseudomonas putida F39/D oxidizes 1,2-dihydronaphthalene to (+)-cis-(1S,2R)-dihydroxy-1,2,3,4-tetrahydronaphthalene, (+)-(1R)-hydroxy-1,2-dihydronaphthalene, and (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. In contrast, naphthalene dioxygenase of Pseudomonas sp. strain NCIB 9816/11 oxidizes 1,2-dihydronaphthalene to the opposite enantiomer, (-)-cis-(1R,2S)-dihydroxy-1,2,3,4-tetrahydronaphthalene and the identical (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. Recombinant Escherichia coli strains expressing the structural genes for toluene and naphthalene dioxygenases confirmed the involvement of these enzymes in the reactions catalyzed by strains F39/D and NCIB 9816/11. 1-Hydroxy-1,2-dihydronaphthalene was not formed by strains expressing naphthalene dioxygenase. These results coupled with time course studies and deuterium labelling experiments indicate that, in addition to direct dioxygenation of the olefin, both enzymes have the ability to desaturate (dehydrogenate) 1,2-dihydronaphthalene to naphthalene, which serves as a substrate for cis dihydroxylation.     

Desaturation, dioxygenation, and monooxygenation reactions catalyzed by naphthalene dioxygenase from Pseudomonas sp. strain 9816-4.

The stereospecific oxidation of indan and indene was examined with mutant and recombinant strains expressing naphthalene dioxygenase of Pseudomonas sp. strain 9816-4. Pseudomonas sp. strain 9816/11 and Escherichia coli JM109(DE3)[pDTG141] oxidized indan to (+)-(1S)-indanol, (+)-cis-(1R,2S)-indandiol, (+)-(1S)-indenol, and 1-indanone. The same strains oxidized indene to (+)-cis-(1R,2S)-indandiol and (+)-(1S)-indenol. Purified naphthalene dioxygenase oxidized indan to the same four products formed by strains 9816/11 and JM109(DE3)[pDTG141]. In addition, indene was identified as an intermediate in indan oxidation. The major products formed from indene by purified naphthalene dioxygenase were (+)-(1S)-indenol and (+)-(1R,2S)-indandiol. The results show that naphthalene dioxygenase catalyzes the enantiospecific monooxygenation of indan to (+)-(1S)-indanol and the desaturation of indan to indene, which then serves as a substrate for the formation of (+)-(1R,2S)-indandiol and (+)-(1S)-indenol. The relationship of the desaturase, monooxygenase, and dioxygenase activities of naphthalene dioxygenase is discussed with reference to reactions catalyzed by toluene dioxygenase, plant desaturases, cytochrome P-450, methane monooxygenase, and other bacterial monooxygenases.     

不同环境下家蚕产量构成因素的通径分析及育种对策的探讨

利用52个家蚕品种在春秋两个季节的试验资料,对万头茧层量及其构成因素作了通径分析。结果表明:不同环境下,诸因素对万头茧层量的作用不完全相同,主要表现为幼虫生命率和茧层率在不同季节中的作用相对地变化。结合育种实践指出:(1)春用蚕品种的选育应在保证生命率的前提下努力提高茧层率和全茧量,而夏秋用品种的选育应在保证茧层率的前提下努力提高生命率和全茧量。 (2)为提高选择效果,春蚕期育种应以选择茧层率为主,夏秋期育种应以选择生命率为主。     

Psychosocial Concerns and Health-Compromising Behaviors among Overweight and Nonoverweight Adolescents

Objective: To compare weight-specific and global psychosocial concerns and health-compromising behaviors among overweight and nonoverweight youth across gender and ethnicity. Methods: A cross-sectional school-based survey of 31,122 adolescents in grades 7 to 12. Based on self-reported heights and weights, respondents were categorized as nonoverweight (body mass index (BMI) <85th percentile), moderately overweight (85th percenile <BMI <95th percentile), or severely overweight (BMI >95th percentile). Results: Global psychosocial concerns, such as emotional well-being, suicidal ideation, future job concerns, and peer concerns, did not differ greatly between nonoverweight, moderately overweight, and severely overweight adolescents. Substance abuse behaviors were equally or less prevalent among the overweight group. Overweight girls were significantly less likely to consume alcohol, whereas overweight boys were at lower risk for marijuana use. In contrast, overweight youth were more likely to perceive their health as only fair or poor and were more likely to express weight-specific concerns and engage in behaviors such as chronic dieting and binge eating than nonoverweight youth. Overweight American Indian girls perceived their physical health more positively than nonoverweight American Indian girls. Strong associations were found between overweight status and chronic dieting among African American boys and girls. Conclusions: Nutritional counseling and educational programs need to address the weight-specific concerns and behaviors of overweight adolescents. However, assumptions regarding global psychosocial concerns and health-compromising behaviors among overweight adolescents of different genders and ethnicities should be avoided. These broad issues need to be explored in more depth at both the research and intervention levels.