云南山楂茎尖的离体培养及其无性系快速繁殖

用云南山楂(Crataegus scabrifolia(Franch.)Rehd.)成年树茎尖和实生芽两种不同发育阶段的材料为外殖体,诱导它们休眠芽萌动,丛生芽条并诱导芽条生根。实验结果如下:1.以成年态的云南山楂侧芽为外植体,培养在附加IAA 0.1—0.5mg/l+6-BA 1-2mg/l的MS培养基上可诱导芽的萌发;将芽继代培养在附加0.5—1mg/l 6-BA的SH或MS培养基上,40天后芽数增殖4—6倍;将芽条截下置于1/2MS培养基上,附加不同浓度的IAA或IBA,可得到50—80％的生根率。2.以实生芽为外殖体,在相同条件下,则20天后芽数增殖便可获4—6倍;98％以上生根。结果表明:云南山楂的幼年态要比成年态易脱分化和再分化。     

香荚兰种子的无菌萌发试验

香荚兰(Vanilla planifolia)是兰科、香荚兰属植物,主产于湿热地区。香荚兰的果实是国际上重要的食用香料的原料。大约在1960年,我国引入香荚兰试栽。生产上,通常用扦插法繁殖;但如用种子繁殖,虽然结实较晚(约7至8年开始结实,较扦插苗晚4—5年),但结实期长,盛产期可维持约15年。而且,在杂交育种过程中,一定要用种子繁殖。     

The lipopolysaccharide of the green sulfur bacterium Chlorobium vibrioforme f. thiosulfatophilum

The cell wall lipopolysaccharide of the green sulfur bacterium Chlorobium vibrioforme f. thiosulfatophilum was obtained by the phenol-chloroform-petroleum ether and the hot phenol-water methods, respectively. It contained mannose, glucose, galacturonic acid, glucosamine, glycine, and small amounts of rhamnose, galactose and glucuronic acid. In addition to d-glycero-d-mannoheptose, the corespecific constituents 2-keto-3-deoxyoctonate and l-glycero-d-mannoheptose were found. Polyacrylamide gel-electrophoresis in the presence of sodium deoxycholate gave no indication for the presence of O-specific repeating units. Degradation of the lipopolysaccharide required 10% acetic acid (100° C, 2 h). The lipid A moiety contained the total of glucosamine of the lipopolysaccharide as well as small amounts of 2,3-diamino-2,3-dideoxy-glucose. It was phosphate-free. The fatty acid spectrum comprised 3-OH-14:0, 3-OH-16:0, and iso-3-OH-18:0 besides little 12:0, 14:0 and 16:0. Hydroxylaminolysis and sodium methylate treatment revealed all of the three hydroxy fatty acids to be amidebound.Abbreviations DOC sodium deoxycholate - PAGE polyacrylamide gel-electrophoresis     

Manganese-binding proteins of the oxygen-evolving complex

The extrinsic 33-kDa protein (P33) was cross-linked covalently to the binding site on P33-depleted PSII preparations which is responsible for reconstitution of photosynthetic water oxidation after PSII preparations have been washed with 1 M CaCl2. Conditions were found in which more than half of the cross-linked protein complexes formed in the PSII preparations retained the ability to catalyze the oxidation of water. The complex is composed of the P33 cross-linked to the D1 and D2 proteins and a 34-kDa protein, which is present in lower abundance than the other three proteins. After solubilization of the membranes with SDS and purification by preparative SDS-PAGE, the complex retains bound manganese and can catalyze the conversion of H2O2 to O2. Calcium and chloride increased the catalase activity of the purified cross-linked complex while lanthanum or hydroxylamine abolished the activity. By use of the specific activity of the H2O2-dependent reaction to follow the extent of purification of the cross-linked complex, the most highly purified complex was determined to contain 0.34 microgram of manganese/180 micrograms of protein. The mole ratio of Mn/protein was calculated to range from 3.6 to 4.5 depending on the assumed stoichiometry of the protein subunits. The results presented here provide direct evidence that one or more of the three proteins that have cross-linked to the P33 are responsible for binding the manganese of the oxygen-evolving complex.     

The lipopolysaccharide of the phototrophic bacterium Ectothiorhodospira vacuolata

The lipopolysaccharide of Ectothiorhodospira vacuolata was obtained by the phenol-water procedure. It contained a 3-O-methyl-hexose, glucose, galacturonic and glucuronic acids. The finding of d-glycero-d-mannoheptose and 2-keto-3-deoxyoctonate (tentatively identified) suggested a core-structure. The lipid fraction of the lipopolysaccharide contained phosphate and both, 2,3-diamino-2,3-dideoxy-d-glucose and d-glucosamine. The major fatty acids were amine-bound 3-OH-10:0 and 3-OH-12:0 and esterbound 14:0 and 16:0 Sodium deoxycholate gel-electrophoresis, showing a single band only, indicated R-type character of the lipopolysaccharide of Ectothiorhodospira vacuolata.Abbreviations DOC sodium deoxycholate - GC/MS combined gasliquid chromatography - PAGE polyacrylamide gel-electrophoresis     

Enterochromaffin-like cells in the rat stomach: effect of α-fluoromethylhistidine-evoked histamine depletion

Summary In the rat, gastric histamine is stored predominantly in the enterochromaffin-like (ECL) cells, which are located basally in the oxyntic mucosa. The functional significance of histamine in the ECL cells is a matter of speculation. In this study the effect of depletion of histamine on the properties and ultrastructure of the ECL cells was examined. Histamine synthesis was inhibited with -fluoromethylhistidine (3 mg·kg^-1·h^-1) given via osmotic minipumps over a period of 24 h. The treatment reduced the histidine decarboxylase activity (approximately 20% remaining) and histamine concentration (less than 20% remaining) in the oxyntic mucosa, as well as the intensity of histamine- and chromogranin A-immunostaining in the ECL cells, compared to control rats. The cytoplasmic (secretory) granules/vesicles were greatly reduced in number and size following -fluoromethylhistidine administration. The histamine immunostaining of the mast cells, which occurs at the mucosal surface and in the submucosa, appeared unaffected. We conclude that ECL cell histamine accounts for at least 80% of the total oxyntic mucosal histamine in the rat and that it represents a more mobile pool than mast cell histamine. The reduction in the number and size of the ECL cell granules/vesicles following histamine depletion is in accord with the idea that they represent the storage site for histamine.     

电损毁海马CA3区及连合前穹窿对大鼠血浆胰岛素水平...

Bilateral electrical lesioning of the hippocampal CA3 region (HCA3-EL) or anterior commissura hippocampi (ACHF-EL) caused marked elevations in plasma basal levels of insulin. 2 weeks later, fasting blood glucose levels were also augmented with decreased glucose tolerance. In contrast, the secretory response of pancreatic B cells to glucose stimulation was markedly enhanced. Following intravenous glucose tolerance test (IVGTT), the relative amounts of glucagon-like and insulin-like immunoreactants were reduced in the pancreatic islets of both HCA3-EL and ACHF-EL rats in comparison with the controls. In the HCA3-EL group, the relative amounts of somatostatin-like immunoreactants and gross numbers of such immunostained cells in islets were also decreased as compared with the control. No difference was seen in pancreatic-polypeptide-like immunoreactivities as assessed by immunohistochemistry plus microphotometry method. The above results suggest strongly that HCA3 and ACHF exert a tonic inhibitory action on the insulin secretion in the rat.     

活性氧对巨噬细胞呼吸爆发影响及云芝多糖的保护作用

用化学发光法观察到叔丁基氢过氧化物对培养的小鼠腹腔巨噬细胞呼吸爆发有强烈的抑制作用。云芝多糖经腹腔注射后,能增强巨噬细胞呼吸爆发功能对叔丁基氢过氧化物损伤的抵抗力。云芝多糖处理的巨噬细胞谷胱甘肽过氧化物酶基础活力显著提高,在叔丁基氢过氧化物作用下,云芝多糖处理的巨噬细胞仍有较高的谷胱甘肽过氧化物酶活力。说明巨噬细胞的免疫功能与谷胱甘肽过氧化物酶活力有关,非特异性免疫多糖可提高细胞抗氧化能力,减轻活性氧损伤作用。