Novel Active Chrysanthemic Esters

The rates of recycling and turnover of glucose in 5-day- and 21-day-old lambs and adult sheep were measured by the method of single simultaneous injection of glucose-6-³H and glucose-6-¹⁴C. The ³H/¹⁴C ratio decreased linearly with time and was 0.58 and 0.60 in lambs of 5-day- and 21-day-old, respectively, and 0.82 in adult sheep at 120 min after injection of the labeled glucose. The pool size and turnover rate of glucose considerably decreased with age. The rate of glucose recycling was significantly higher in lambs of both ages (22.0 and 26.2%, respectively) than in adult sheep (11.1 %).     

大蒜中生理活性物质对致病细菌的体外抑制作用

目的：从鲜蒜中提取蒜氨酸、蒜氨酸酶和蒜素,测定了蒜氨酸、蒜氨酸酶、蒜氨酸＋蒜氨酸酶、蒜素和蒜汁对10种致病细菌的抑菌作用及最低抑菌浓度。方法：采用平板打孔法和液体2倍稀释法。结果：蒜氨酸酶、蒜氨酸＋蒜氨酸酶、蒜素和蒜汁对金黄色葡萄球菌、大肠杆菌、鲍曼不动杆菌等10种菌株的抑菌环直径均大于7mm。蒜氨酸＋蒜氨酸酶对鲍曼不动杆菌的抑菌作用是50mg／mL氨苄青霉素的1．5倍。蒜氨酸＋蒜氨酸酶对金黄色葡萄球菌、类产碱假单胞菌和福氏志贺氏菌的MIC为0．19mg/mL。结论：蒜氨酸酶、蒜氨酸＋蒜氨酸酶、蒜素和蒜汁在体外具有明显的抑菌作用。     

Structure of a Physiologically Active Polysaccharide Produced by Bacillus polymyxa S-4

The structure of an acidic polysaccharide elaborated by Bacillus polymyxa S-4 was investigated in relation to its physiological activity, particularly, its hypocholesterolemic effect on experimental animals. The polysaccharide is composed of d-glucose, d-mannose, d-galactose, d-glucuronic acid, and d-mannuronic acid (molar ratio 3:3:1: 2:1). Methylation and fragmentation analyses, such as Smith degradation and partial acid hydrolysis showed that the polysaccharide has a complicated, highly branched structure, consisting mainly of (1 → 3)- and (1 → 4)-d-glycosidic linkages. The backbone chain containing d-glucuronic acid, d-mannose, and d-galactose residues is attached at the C-3, C-4, and C-4 positions, respectively, with side chains of single or a few carbohydrate units, which are terminated with d-glucose or d-mannose residues.     

A C-Terminal Phosphatase Module Conserved in Vertebrate CMP-Sialic Acid Synthetases Provides a Tetramerization Interface for the Physiologically Active Enzyme

The biosynthesis of sialic acid-containing glycoconjugates is crucial for the development of vertebrate life. Cytidine monophosphate-sialic acid synthetase (CSS) catalyzes the metabolic activation of sialic acids. In vertebrates, the enzyme is chimeric, with the N-terminal domain harboring the synthetase activity. The function of the highly conserved C-terminal domain (CSS-CT) is unknown. To shed light on its biological function, we solved the X-ray structure of murine CSS-CT to 1.9 Å resolution. CSS-CT is a stable shamrock-like tetramer that superimposes well with phosphatases of the haloacid dehalogenase superfamily. However, a region found exclusively in vertebrate CSS-CT appears to block the active-site entrance. Accordingly, no phosphatase activity was observed in vitro, which points toward a nonenzymatic function of CSS-CT. A computational three-dimensional model of full-length CSS, in combination with in vitro oligomerization studies, provides evidence that CSS-CT serves as a platform for the quaternary organization governing the kinetic properties of the physiologically active enzyme as demonstrated in kinetic studies.     

Low Vitamin D Status and Suicide: A Case-Control Study of Active Duty Military Service Members

Objective

Considering that epidemiological studies show that suicide rates in many countries are highest in the spring when vitamin D status is lowest, and that low vitamin D status can affect brain function, we sought to evaluate if a low level of 25-hydroxyvitamin D [25(OH)D] could be a predisposing factor for suicide.

Method

We conducted a prospective, nested, case-control study using serum samples stored in the Department of Defense Serum Repository. Participants were previously deployed active duty US military personnel (2002–2008) who had a recent archived serum sample available for analysis. Vitamin D status was estimated by measuring 25(OH) D levels in serum samples drawn within 24 months of the suicide. Each verified suicide case (n = 495) was matched to a control (n = 495) by rank, age and sex. We calculated odds ratio of suicide associated with categorical levels (octiles) of 25(OH) D, adjusted by season of serum collection.

Findings

More than 30% of all subjects had 25(OH)D values below 20 ng/mL. Although mean serum 25(OH)D concentrations did not differ between suicide cases and controls, risk estimates indicated that subjects in the lowest octile of season-adjusted 25(OH)D (<15.5 ng/mL) had the highest risk of suicide, with subjects in the subsequent higher octiles showing approximately the same level of decreased risk (combined odds ratio compared to lowest octile  = 0.49; 95% C.I.: 0.315–0.768).

Conclusions

Low vitamin D status is common in active duty service members. The lowest 25(OH)D levels are associated with an increased risk for suicide. Future studies could determine if additional sunlight exposure and vitamin D supplementation might reduce suicide by increasing 25(OH) D levels.     

Antioxidative and Prooxidative Abilities of some Biological Substances and Physiologically Active Substances on the Oxidation of Unsaturated Fatty Acids

Some biological substances and physiologically active substances such as amino acids, hormones, vitamins, medicines and the other substances were added into the linoleic acid solution; and antioxidative and prooxidative abilities of these substances, the abilities to act as electron donors or acceptors, were tested. Many substances were effective as the antioxidant and some others showed prooxidative effects. These facts suggested the possibility of the occurrence of many reactions involving the transfer of an electron among biological processes.     

活性维生素D3对大鼠系膜增生性肾炎PCNA的影响

目的:研究活性维生素D3对大鼠系膜增生性肾小球肾炎的作用及机制.方法:应用抗大鼠胸腺细胞免疫血清(Anti-thymocyte serum,ATS)抗体一次性尾静脉注射复制大鼠系膜增生性肾小球肾炎(Mesangial Proliferative Glomerulonephritis,MsPGN)模型,将实验大鼠分为三组对照组(A组)、模型组(B组)、活性维生素D3治疗组(C组),分别与1、3、7、14天每组各处死6只大鼠,并采用Envision免疫组化法、RT-PCR法,观察PCNA蛋白、PCNAmRNA及中性粒细胞在肾小球中的表达情况.结果:肾炎组增殖细胞核抗原(Proliferating cell nuclear Antigen,PCNA)蛋白、PCNAmRNA及肾小球中中性粒细胞计数明显高于对照组(p＜0.01),并随着时间延长逐渐增高,到第7天达到高峰,第14天有下降的趋势.活性维生素D3治疗组PCNA蛋白、PCNAmRNA及肾小球中中性粒细胞计数的表达均较低(p＜0.01),其中第3、7、14天表达均显著减少(p＜0.05).PCNA蛋白、PCNAmRNA、中性粒细胞计数各指标之间呈均成正相关.结论:活性维生素D3可以抑制系膜细胞的增生,其作用机制可能是抑制炎症细胞浸润、PCNAmRNA及其蛋白的表达.     

微生物转化制备活性维生素D_3的研究进展

活性维生素D类药物作为一类高效原料药,采用化学合成方法,制备复杂,限制了其广泛应用。采用微生物转化法条件温和,操作简单,对于活性维生素D3的制备具有重要意义。从甾体羟化菌株,生物转化制备不同活性维生素D3、基因工程在生物转化上的应用及转化率的影响因素等方面综述了其研究进展,并对该领域的发展趋势进行了展望。     

A New Crystalline form of Monosodium l-Glutamate

A new crystalline form of monosodium l-glutamate, which is different from the known monosodium l-glutamate monohydrate crystal in external appearance, density, X-ray diffraction pattern, solubility, and water of crystallization, has been crystallized from ca. 73 weight per cent aqueous methanol solution at ca. 18°C. It was identified as the dihydrate from the determination of water of crystallization based on Karl Fischer′s method. The newly found crystals are extremely unstable in air, aqueous solution, and the mother liquor, because of rapid transformation into the stable monohydrate, whereas they can be kept in a considerably stable condition in absolute ethanol and acetone.     

A Crystalline P-Protein in Gmelina arborea

In a light microscope study of the secondary phloem in Gmelinaarborea (Verbenaceae) many sieve elements were found to possessbar-shaped cytoplasmic inclusions of proteinaceous nature Itis suggested that these inclusions represent a type of crystallineP-protein not reported in the family Verbenaceae before Crystalline P-protein, phloem, sieve element inclusion     

Increased 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Activity in Shoots of Flooded Tomato Plants Raises Ethylene Production to Physiologically Active Levels

Soil flooding increased 1-aminocyclopropane-1-carboxylic (ACC) acid oxidase activity in petioles of wild-type tomato (Lycopersicon esculentum L.) plants within 6 to 12 h in association with faster rates of ethylene production. Petioles of flooded plants transformed with an antisense construct to one isoform of an ACC oxidase gene (ACO1) produced less ethylene and had lower ACC oxidase activity than those of the wild type. Flooding promoted epinastic curvature but did so less strongly in plants transformed with the antisense construct than in the wild type. Exogenous ethylene, supplied to well-drained plants, also promoted epinastic curvature, but transformed and wild-type plants responded similarly. Flooding increased the specific delivery (flux) of ACC to the shoots (picomoles per second per square meter of leaf) in xylem sap flowing from the roots. The amounts were similar in both transformed and wild-type plants. These observations demonstrate that changes in ACC oxidase activity in shoot tissue resulting from either soil flooding or introducing ACC oxidase antisense constructs can influence rates of ethylene production to a physiologically significant extent. They also implicate systemic root to shoot signals in regulating the activity of ACC oxidase in the shoot.     

Vitamin A Reserves of Canadians

—A survey of vitamin A and carotene stores of Canadians at five major centres across Canada was completed. Vitamin A and carotene analyses were performed on approximately 100 human liver specimens obtained at necropsy from each location.Age influenced liver vitamin A stores. Children between 1 and 10 years of age had the highest vitamin A stores while a trend toward lower liver stores occurred between 20 and 40 years of age. Females had higher liver carotene stores than males but there was no such difference in vitamin A stores.Subjects from all locations were classified according to cause of death: accidental, heart and coronary artery diseases, cancer, respiratory diseases and a miscellaneous disease group. The mean liver vitamin A and carotene stores of the accidental death group differed only from the cancer group. In contrast to the disease groups, no case with undetectable vitamin A was found in the accidental death group.The mean vitamin A and carotene stores of Vancouver subjects were generally higher than those for the other locations. Montreal showed more values in the 0-40 μg. per g. range than the other locations. Vancouver had the least number (15%), with Halifax, Ottawa and Winnipeg being intermediate (32%). These data suggest the need for improved nutrition, prophylactic treatment in disease states and the need for further research on the utilization and metabolism of vitamin A.