正常人各年龄组染色体着丝粒点(Cd)研究

本文运用本室改良的Cd-NOR银染技术对80例4个年龄组的正常中国人的Cd变化进行了较系统的研究, 结果表明:(1)正常人随年龄增加,Cd消失的频率、Cd变异及Cd-NOR融合频率也相应增加,特别是Ⅲ、Ⅳ组(中、老年组)增加的频率尤为显著;(2)首次对Cd消失的过程提出了独特的观点,即Cd消失首先表现为Cd变小, 随着变小程度的加大,最终导致Cd消失;(3)在本研究中首次观察到单个Cd的现象,作者认为是细胞分裂中期染色体着丝一分为二的延迟现象。各年龄组间单Cd出现频率无统计学差异,同一年龄组中,2号染色体和1号染色体上单Cd出现频率显著高于理论值;(4)随年龄增高,Cd各项观察值的增高在男性与女性间未见明显的差异。 Abstract:The Cd variation of human chromosome in four groups of different age has been investigated.The result shows that the frequencies of Cd disappearing,size variation and Cd-NOR fusion increased with the age rising,especially in the group of aged people.We suggest that the variation of Cd shows the size changes first,and then disappears completely.We also observed some cells in which a few chromosomes shows only a single Cd in centromeric region.Cd variation in different age groups has no significant difference between the male and the female.     

银杏速生早实示范栽培试验

本研究是在我区银杏主产区兴安进行的８０多亩,３０００多株的示范栽培试验。其综合技术措施是选用良种嫁接苗、适当密植、配置雄株、整形修剪、合理施肥、防治病虫害及促花早实等。种后５—６年取得速生、早实、高产的良好效果。     

稻—萍—鱼系统中红萍氮素吸收利用及有效性研究

本文报道以红萍为饵料,鱼类对红萍氮素消化吸收、转化情况。试验结果表明:草鱼和尼罗罗非鱼对红萍氮素的消化和吸收率约为60％,其中30％红萍氮素转化为鱼体动物蛋白,另外约30％氮素排出体外。在田间条件下,尼罗罗非鱼摄食红萍,每季平均增长率约为41—40％。稻田养鱼,以萍喂鱼,鱼粪肥田,萍体氮素得以吸收利用,效益明显。在稻萍鱼体系中,当季红萍氮素的总利用率可达45—50％,而红萍单作肥料处理其利用率仅为30—36％,第二季作物对红萍残留氮素回收率可达7.83—9.64％,比红萍单作肥料处理高3.33—4.11％。第二季残效明显优于红萍压施处理,晚季稻谷产量的增产率可达13—25％,比压施红萍作肥料处理高7—8％。     

发展生态渔业,保护水域环境——朱湖水体生态农业初探

渔业是大农业的一环。在充分合理的利用好水体自然资源,大力发展水产品生产的同时,认真保护好水域生态环境,这不仅是渔业的问题,也完全符合环保这项基本国策。研究渔业生态,发展生态渔业也是当今水产养殖发展的主要方向。“水体生态农业”是依据生态学原理,生态     

An isotope edited classical Raman difference spectroscopic study of the interactions of guanine nucleotides with elongation factor Tu and H-ras p21

We have measured the Raman spectrum of GDP bound to the elongation factor protein, EF-Tu, and the c-Harvey-ras protein, p21, two proteins of the guanine nucleotide binding family. In order to separate the Raman spectrum of the nucleotide from the much more intense protein spectrum, we investigate the feasibility of "tagging" the normal modes of the nucleotide by isotopic substitution, here by incoporating deuterium-labeled guanine at the C8 position into the active site. A difference spectrum between the labeled and unlabeled protein-nucleotide complex shows the changes in the Raman spectrum of the bound nucleotide that arise from the isotopic exchange. We find that surprisingly good Raman spectra of bound ligands can be obtained with this method and that the method can be easily generalized to other systems. The data show that the guanine amino group of the nucleotide interacts differently with both EF-Tu and p21 than it does with water, showing a change in hydrogen-bonding properties upon binding. On the other hand, no change in hydrogen bonding is observed at guanine's N7. The data strongly suggest that the conformation of the nucleotide when bound to EF-Tu and that p21 is the C2' endo pucker of the ribose ring and anti about the glycosidic bond. These results are compared to previous structural and chemical studies.     

Preparation of enteric-coated microspheres of Mycoplasma hyopneumoniae vaccine with cellulose acetate phthalate: The effect of swine serum on micromeritic properties

Summary Cellulose acetate phthalate was used to prepare the Mycoplasma hyopneumoniae vaccine (MHV) microspheres using a solvent evaporation method. Swine serum was used as an additive in the antigen to form the core materials. The addition of serum had a significant effect on surface topography of the MHV microspheres. By using this modified solvent evaporation method, the recoveries of antigens in the MHV microspheres were generally over 90% of the weight and antigenicity of antigens originally added in the formulation.     

Effect of increased gas density on pulmonary gas exchange in man.

Pulmonary gas exchange was measured in seven resting supine subjects breathing air or a dense gas mixture containing 21% O2 in sulfur hexafluoride (SF6). The mean value of the alveolar-arterial oxygen difference (AaDO2) decreased from 12.4 on air to 7.0 on SF6 (P less than 0.01), and increased again to 13.4 when air breathing resumed (P less than 0.01). No differences occurred between gas mixtures for O2 consumption, respiratory quotient, minute ventilation, breathing frequency, heart rate, or blood pressure, and the improved oxygen transfer could not be attributed to changes in cardiac output or mixed venous oxygen content in the one subject in which they were measured. These results are best explained by an altered distribution of ventilation during dense gas breathing, so that the ventilation-perfusion ratio (VA/Q) variance was reduced. Of several considered mechanisms, we favor one in which SF6 promotes cardiogenic gas mixing between peripheral parallel units having different alveolar gas concentrations. This mechanism allows for observed increases in arterial carbon dioxide tension and dead space-to-tidal volume ratio during dense gas breathing, and suggests that intraregional VA/Q variance accounts for at least one-half of the resting AaDO2 in healthy supine young men.     

Early and late replicative chromosomal banding patterns of Gallus domesticus.

Early and late replicating chromosomal banding patterns of Gallus domesticus were investigated by cell synchronization and incorporation of 5'-bromodeoxyuridine during early and late DNA synthesis. The early replicating chromosomal banding patterns observed, as revealed by either acridine orange or Hoechst 33258/propidium iodide staining, were similar to the structural G-banding patterns obtained by trypsin digestion and Giemsa staining. Late replicating chromosomal banding showed extensive reverse band complementarity to the G-banding pattern. Cell synchronization increased the number of prometaphase and metaphase plates available for analysis. G-banding obtained by Hoechst 33258/propidium iodide staining was investigated due to the fact that it is compatible with chromosomal in situ hybridization procedures that use nonisotopically-labeled DNA probes. Standard replicative G-banded and R-banded idiograms, as obtained after cell synchronization, are proposed.     

An infrared probe of iro n porphyrin oxidation state and axial ligation.

Carbonyl stretching frequencies of acyl groups conjugated with porphyrin rings are useful probes of the effective electronegativities of corrdinated iron atoms in iron porphyrins. Acetyl carbonyl stretching frequencies for 2,4-diacetyldeuteroporphyrin IX dimethyl ester derivatives exhibit both metal oxidation state and axial ligand effects. Infrared spectra of chloroform and pyridine solutions, corrected for solvation, showed the sequences of acetyl carbonyl stretching frequencies: dipyridine iron(II) less than mu-oxo bisiron(III) less than bromo iron(III) approximately equal to chloro iron(III) and dipyridine nickel(II) less than nickel(II). Applications of the probe to the study of hemeproteins are indicated.     

Neobavaisoflavone inhibits osteoclastogenesis through blocking RANKL signalling‐mediated TRAF6 and c‐Src recruitment and NF‐κB,MAPK and Akt pathways

Psoralea corylifolia (P corylifolia) has been popularly applied in traditional Chinese medicine decoction for treating osteoporosis and promoting fracture healing since centuries ago. However, the bioactive natural components remain unknown. In this study, applying comprehensive two‐dimensional cell membrane chromatographic/C18 column/time‐of‐flight mass spectrometry (2D CMC/C18 column/TOFMS) system, neobavaisoflavone (NBIF), for the first time, was identified for the bioaffinity with RAW 264.7 cells membranes from the extracts of P corylifolia. Here, we revealed that NBIF inhibited RANKL‐mediated osteoclastogenesis in bone marrow monocytes (BMMCs) and RAW264.7 cells dose dependently at the early stage. Moreover, NBIF inhibited osteoclasts function demonstrated by actin ring formation assay and pit‐formation assay. With regard to the underlying molecular mechanism, co‐immunoprecipitation showed that both the interactions of RANK with TRAF6 and with c‐Src were disrupted. In addition, NBIF inhibited the phosphorylation of P50, P65, IκB in NF‐κB pathway, ERK, JNK, P38 in MAPKs pathway, AKT in Akt pathway, accompanied with a blockade of calcium oscillation and inactivation of nuclear translocation of nuclear factor of activated T cells cytoplasmic 1 (NFATc1). In vivo, NBIF inhibited osteoclastogenesis, promoted osteogenesis and ameliorated bone loss in ovariectomized mice. In summary, P corylifolia‐derived NBIF inhibited RANKL‐mediated osteoclastogenesis by suppressing the recruitment of TRAF6 and c‐Src to RANK, inactivating NF‐κB, MAPKs, and Akt signalling pathways and inhibiting calcium oscillation and NFATc1 translocation. NBIF might serve as a promising candidate for the treatment of osteoclast‐associated osteopenic diseases.