大麦芽发酵物化学成分的鉴别分离及其抗缺氧效果研究

目的研究鉴别大麦芽发酵物的成分组成,分离其抗缺氧有效成分,为建立药物有效成分提取分离工艺及减少服药剂量提供科学依据.方法按药典方法测定发酵物的理化指标;发酵物分别用水和乙醇提取分离后,通过纸层析法和试管法,用特异显色剂进行化学成分鉴别;采用溶剂极性梯度、乙醇浓度梯度、酸性溶剂三种方法,分别对大麦芽发酵物搅拌回流提取两次,离心分离,回收溶剂,浓缩,低温干燥作试样;溶剂不溶物低温干燥后也作试样;选雄性健康小白鼠,按体重随机分组,每组20只.腹腔注射0.2ml药液,给药40min后,置125ml广口瓶中以橡皮塞密闭进行抗缺氧实验,观察记录动物死亡时间,同时设原发酵物和蒸馏水空白两个对照组.最后统计实验组与对照组的动物存活时间增加率,并对组间结果进行t检验.结果大麦芽发酵物含蛋白质18.99%,总糖17.50%,总酸度9.01%;纸层析法和试管法定性鉴别试样中蛋白质、糖类、有机酸、酚性物和油脂均呈阳性;不同溶剂提取物的动物密闭抗缺氧效果均非常显著高于水对照组(P＜0.01),但却明显低于原发酵物对照组.而不同溶剂不溶物的抗缺氧效果则显著优于原发酵物(P＜0.05).结论发酵物含蛋白质、肽类、氨基酸、单糖、还原糖、多糖类、有机酸、酚性物和油脂等成分.其抗缺氧有效成分可能是一类弱极性化学物质.     

Cholinesterases and peanut agglutinin binding related to cell proliferation and axonal growth in embryonic chick limbs

Embryonic cholinesterases are assigned important functions during morphogenesis. Here we describe the expression of butyrylcholinesterase and acetylcholinesterase, and the binding of peanut agglutinin, and relate the results to mitotic activity in chick wing and leg buds from embryonic day 4 to embryonic day 9. During early stages, butyrylcholinesterase is elevated in cells under the apical ectodermal ridge and around invading motoraxons, while acetylcholinesterase is found in the chondrogenic core, on motoraxons and along the ectoderm. Peanut agglutinin binds to the apical ectodermal ridge and most prominently to the chondrogenic core. Measurements of thymidine incorporation and enzyme activities were consistent with our histological findings. Butyrylcholinesterase is concentrated near proliferative zones and periods, while acetylcholinesterase is associated with low proliferative activity. At late stages of limb development, acetylcholinesterase is concentrated in muscles and nonexistent within bones, while butyrylcholinesterase shows an inverse pattern. Thus, as in other systems, in limb formation butyrylcholinesterase is a transmitotic marker preceding differentiation, acetylcholinesterase is found on navigating axons, while peanut agglutinin appears in non-invaded regions. These data suggest roles for cholinesterases as positive regulators and peanut-agglutinin-binding proteins as negative regulators of neural differentiation.     

Propolis allergy

87% of the propolis product "LB-1", originally reported to be 1,1-dimethyl-allyl caffeic acid ester, was shown by GC/MS analysis to consist of 3 isomeric pentenyl caffeates, 63% of which are 1,1-dimethylallyl caffeate. These pentenyl caffeates proved to be the major sensitizers of propolis and of poplar bud secretion in our previous study. In addition, 3 further minor allergens have now been investigated. Experimental sensitization indicates that phenylethyl caffeate is as strong a sensitizer as the major allergen "LB-1", while benzyl salicylate is a moderate sensitizer. Benzyl cinnamate plays only a subordinate role. At least 3 further esters of caffeic acid or cinnamic acid remain to be studied. Interestingly, relationships between propolis and balsam of Peru were found. 8 compounds are common to both materials. Thus "cross-reactions" or concomitant reactions in propolis-sensitive individuals to balsam of Peru are explainable.     

Mathematical modelling of the growth processes in the developing chick wing bud

This paper illustrates how a simple geometric model resembling the shape of the chick wing bud at an early growth stage can be mathematically expanded to simulate subsequent growth characteristics of the developing bud. The model was tested against several sets of experimental data and gave an acceptable representation of growth over the range considered. Representing growth patterns in this form enables the determination of differential growth characteristics in different parts of the bud and provides boundary constraints which will play an important part in the eventual evaluation of internal growth mechanisms.     

The regulative potential of the limb region in 11.5-day rat embryos following the amputation of the fore-limb bud

Summary The regulative potential of the fore-limb region following the removal of the limb bud was investigated in 11.5-day rat embryos. Fore-limb buds were amputated from a total of 54 embryos. Five embryos were immediately examined via scanning electron microscopy (SEM) to assess the quality of the operation and the reproducibility of the technique. In all cases, the forelimb bud and adjacent tissues extending down to the celomic cavity at the same level were completely removed. The remaining 49 operated embryos were cultured in vitro and examined at different time intervals. Gross inspection of embryos which had been cultured for 24 h, revealed that 24 out of 37 had developed a pair of limb bud-like protrusions at the operation site. Twelve formed only a single protrusion, while nothing was found in the remaining embryo. These protrusions were examined in greater detail under SEM and light microscopy. SEM observations showed that these protrusions were covered with an intact layer of ectoderm. In embryos with a pair of protrusions, these outgrowths developed opposite somites 7 to 13. The failure of either one of these two outgrowths to form, produced our second type of experimental embryo, those which had just a single protrusion. Histological examination revealed that an apical ectodermal ridge (AER) was discernible on the protrusions of 36% of the embryos. Finally, we have established how these protrusions were constructed from SEM observations of operated embryos cultured for 6 h and 10 h.     

The effects of high dose of parathyroid hormone on fetal osteoclasts and their precursors in vivo: An ultrastructural-cytochemical study

Background: It is not well known how the immediate precursors of osteoclast develop into osteoclasts in the fetus. This ultrastructural-cytochemical study was designed to clarify the formation process of the osteoclasts and their increased activities in the fetal mouse limb buds after administration of high dose parathyroid hormone (PTH). Methods: Twenty-four or forty-eight hours after the high doses of PTH were injected into amniotic fluid of the pregnant C₃H mice, the femoral limb buds of embryos were dissected out. Tartrate-resistant acid phosphatase (TRAP) reactions were performed while preparing specimens for electron microscopy. Results: Both control and PTH-given preosteoclasts and osteoclasts exhibited TRAP-positivities in dense bodies and vesicles. As effects of PTH, a binucleated preosteoclast of tandem fashion was observed. More osteoclastic hyperactivities were observed in the diaphyseal bone marrow. An osteoclast with a large cytoplasm exhibited two sets of clear zones and ruffled borders. Some osteoclasts demonstrated prominent amoeboid figures, while other osteoclasts developed large cytoplasmic vacuoles, which contained pieces of calcified chondroid bars. Conclusions: Our results revealed the progression of maturation from young preosteoclasts to osteoclasts. An existence of a peculiar binucleated preosteoclasts suggested one of the processes for multinucleation of the osteoclast. Quite remarkable osteoclastic hyperactivities were obviously the effects of high dose PTH. Our results also indicated the endophagocytic ability of the osteoclast. How PTH affected the osteoclasts and their precursors in the diaphyseal bone marrow can be speculated. © 1995 Wiley-Liss, Inc.     

Inhibition of prostaglandin synthesis reduces cyclic AMP levels and inhibits chondrogenesis in cultured chick limb mesenchyme

The present study investigated effects of inhibiting the synthesis of prostaglandins (PGs) on cyclic AMP concentrations and chondrogenesis in cultured chick limb mesenchyme. Indomethacin produced concentration-dependent inhibition of both PGE₂ synthesis and chondrogenesis over a concentration range of 50--200 M. Half maximal inhibition of PGE₂ was achieved with 50 M concentrations of the drug which also produced visibly reduced amounts of cartilage matrix in cell cultures as evaluated by Alcian green staining on day 6 of culture. The inhibitory effects of indomethacin on chondrogenesis were largely reversed by addition of 1 mM dibutyryl cAMP, indicating that cells could still respond to cyclic AMP stimulation. Endogenous levels of cyclic AMP, which increased by 6 fold during the six days of culture in control cells, did not increase significantly from dissociated cells at the time of plating (day 0) in indomethacin-treated cultures. The results indicate that inhibition of the prechondrogenic rise in PGE₂ concentrations in limb mesenchyme prevents the increase in cyclic AMP levels which occur during this same period resulting in inhibition of chondrogenesis. The data provide further support for the hypothesis that PGE₂, through its effects on the adenylate cyclase-cAMP system, plays an important role in the differentiation of cartilage.     

翅果油树休眠芽和种子的试管萌发

目的：为了扩大珍稀濒危植物翅果油树组织培养的取材范围和研究其种子休眠的原因。方法：以翅果油树一年生枝条的休眠芽（分别于10,11,12,1,2,3,月份取材）和当年生种子为材料,采用MS为基本培养基,附加6－BA,NAA,GA3等外源激素进行试管苗萌发研究。结果：1．休眠芽的萌发率表现为从秋季到冬季逐渐下降和从冬季到春季逐渐提高的规律性变化。其中以3月份取材最佳,休眠芽可萌发为小苗。2．对种子进行试管内和试管外萌发研究,表明翅果油树种子休眠的原因有：中果皮坚硬,种皮革质化,透水透气性差,中果皮和种皮内有抑制物质存在;种仁营养丰富,易引起土壤,空气中微生物的繁殖而烂种;此外,裸露的种仁在试管中的萌发率高达70％,可发育为无菌苗。结论：3月份取材的休眠芽和种仁无菌萌发的实生苗可为组织培养提供新的材料来源。     

天麻的组织培养及快速繁殖

目的：利用组织培养方法快速繁殖成米麻作为种麻,为寻找出一简便可行的快繁天麻种麻的新途径提供理论依据。方法：天麻块茎或茎尖无菌离体培养,米麻块茎诱导培养基为1／2MS＋6－BA 1mg/L NAA0.5mg/L＋香蕉50mg/L;箭麻茎尖诱导培养基为1／2MS＋6－BA2mg/L NAAO.2mg/L。结果：小米麻经50d无菌培养后开始生长出新米麻,70d后原小米麻块茎上生长出多个分枝的新米麻;箭麻茎尖超过140d组织培养,茎尖分化、诱导形成原球茎,超过160d培养原球长大并开花。结论：天麻可以用组织培养方法快速繁殖成米麻作为种麻。     

五氧化二钒的体外发育毒性研究

采用胚胎肢芽细胞进行原代微团培养 ,培养物经不同浓度的五氧化二钒 (V2 O5 )对细胞肢芽细胞经 5天增减形成细胞集落 ,V2 O5 对体外肢芽细胞的分化有明显抑制作用 ,并有较明显的剂量 -效应关系 ,其半数生长抑制浓度(ICV5 0 )和半分化抑制浓度 (ICD5 0 )分别为 12 .6和 1.6μg ml,V D值为 7.9。表明抑制细胞分化可能是V2 O5 致发育危害的重要作用机理