血红细胞超氧化物歧化酶(SOD)制备工艺的研究初报

本文报告了本实验室设计的由血红细胞自溶液60℃热变性, 乙醇——氯仿法除血红蛋白,旋转蒸发法减压浓缩抽去氯仿、乙醇,硫酸铵分级盐析法沉降SOD,Sepbadex G-75层析提纯SOD等步骤构成的一条成本低、设计合理、简便实用的分离纯化SOD的工艺路线。     

The APOA4 Thr347→Ser347 Polymorphism Is Not a Major Risk Factor of Obesity

Objective: The goal of this study was to assess the association between the APOA4 Thr₃₄₇→Ser₃₄₇ polymorphism and BMI and obesity. Research Methods and Procedures: Men and women (n = 3320), randomly recruited in three independent population surveys from the north, east, and south of France, were genotyped for the APOA4 Thr₃₄₇→Ser₃₄₇ polymorphism. Results: There were 1327 overweight (825 men, 502 women) and 611 obese (313 men, 298 women) subjects. The prevalences of subjects carrying at least one Ser₃₄₇ allele (*/Ser₃₄₇) were 36.5%, 33.8%, and 34.3% in controls, overweight, and obese subjects, respectively (not significant), and those of the Ser₃₄₇/Ser₃₄₇ genotype were 4.5%, 3.0%, and 2.2%, respectively (not significant). In both men and women, mean BMI and body weight were not significantly different among APOA4 genotypes. There was no evidence of heterogeneity among centers, smoking status, alcohol intake, physical activity, and educational level categories. In men, mean waist girth was lower in Ser₃₄₇/Ser₃₄₇ (92.2 ± 9.4 cm) than in Thr₃₄₇ carriers (95.9 ± 10.9 cm; p = 0.01), and plasma triglycerides levels were lower in Ser₃₄₇ (1.41 ± 1.04 mM) than in Thr₃₄₇/Thr₃₄₇ carriers (1.55 ± 1.23 mM; p = 0.01). Discussion: These results suggest that the APOA4 347Ser allele is not a major risk factor for obesity or overweight.     

Cigarette Smoking and Fat Distribution in 21, 828 British Men and Women: A Population‐based Study

Objective: To examine the relationship between cigarette smoking habits and fat distribution in a population‐based cohort of men and women. Research Methods and Procedures: We analyzed cross‐sectional data from 21, 828 men and women who were 45 to 79 years of age, residents in Norfolk, United Kingdom, and were recruited between 1993 and 1997. Cigarette smoking habits and other lifestyle factors were assessed using self‐reported questionnaires. Anthropometric measures were obtained during a health examination. Results: Waist‐hip ratio was highest among current smokers and least among never smokers after adjusting for age, BMI, alcohol intake, total energy intake, physical activity, and education. Higher waist‐hip ratio was directly associated with higher smoking pack‐years in current and former smokers and inversely with duration since quitting smoking in former smokers. Adjusting for age, BMI, and other covariates, current smokers had higher waist circumference but lower hip circumference compared with former or never smokers. Discussion: Cigarette smoking habits seem to influence fat distribution patterns. Although smokers have lower mean BMI compared with nonsmokers, they have a more metabolically adverse fat distribution profile, with higher central adiposity. The explanation for this association may help elucidate the mechanisms underlying the adverse health consequences of cigarette smoking and abdominal obesity.     

Molecular Requirements for Bi-directional Movement of Phagosomes Along Microtubules

Microtubules facilitate the maturation of phagosomes by favoring their interactions with endocytic compartments. Here, we show that phagosomes move within cells along tracks of several microns centrifugally and centripetally in a pH- and microtubuledependent manner. Phagosome movement was reconstituted in vitro and required energy, cytosol and membrane proteins of this organelle. The activity or presence of these phagosome proteins was regulated as the organelle matured, with “late” phagosomes moving threefold more frequently than “early” ones. The majority of moving phagosomes were minus-end directed; the remainder moved towards microtubule plus-ends and a small subset moved bi-directionally. Minus-end movement showed pharmacological characteristics expected for dyneins, was inhibited by immunodepletion of cytoplasmic dynein and could be restored by addition of cytoplasmic dynein. Plus-end movement displayed pharmacological properties of kinesin, was inhibited partially by immunodepletion of kinesin and fully by addition of an anti-kinesin IgG. Immunodepletion of dynactin, a dynein-activating complex, inhibited only minus-end directed motility. Evidence is provided for a dynactin-associated kinase required for dyneinmediated vesicle transport. Movement in both directions was inhibited by peptide fragments from kinectin (a putative kinesin membrane receptor), derived from the region to which a motility-blocking antibody binds. Polypeptide subunits from these microtubule-based motility factors were detected on phagosomes by immunoblotting or immunoelectron microscopy. This is the first study using a single in vitro system that describes the roles played by kinesin, kinectin, cytoplasmic dynein, and dynactin in the microtubule-mediated movement of a purified membrane organelle.     

From fresh vegetables to the harvest of wheat plants grown in the "SVET" space greenhouse onboard the MIR orbital station

Researchers report the results of experiments conducted onboard MIR in 1990, 1995, and 1996 in raising edible crops. In the 1990 experiment, radishes and Chinese cabbage were grown successfully, though the experimental plants were up to four times smaller than controls at harvest. The 1995 experiment in growing wheat through a complete life cycle was not completed. The 1996 experiment was successful in growing wheat through a complete life cycle to the seed stage. No seeds developed on any of the 279 ears harvested in that experiment. Reasons for the seedless development are explored.