五种海桑属红树植物叶片的结构及其生态适应

对海桑属五种红树植物的叶片进行解剖学的观察和研究。结果表明:海桑属红树植物的叶片上、下均有栅栏组织,栅栏组织与叶片厚的比值在0.3375～0.4349之间,属等面叶;表皮的角质膜厚1.88～7.63μm;输导组织发达;多数种类的栅栏组织中有分泌腔,而海绵组织中有单宁异细胞分布。说明了海桑属红树植物叶片的结构具有很强的耐旱及抗腐蚀能力。     

山东滨海盐生植物叶结构的比较研究

通过对１１科１４属１４种滨海盐生植物的叶焉结构的比较研究表明：（１）生长在同一盐生环境中的１４种植物,其中片具有许多结构的共同适应特征,如表皮细胞大小不等,外切向壁外突;栅栏组织发达;存在结晶细胞,单宁细胞和贮水细胞;机械绷带和维管组织都不发达等。     

石蒜属12种植物叶片比较解剖学研究

对石蒜属（Lycoris Herb．）12种植物叶片的比较解剖学研究表明：（1）石蒜属植物叶片横切面的端部、中部及基部的轮廓基本呈浅“W”或“V”字型,有些种的表皮细胞上具有明显的尖刺状乳突;（2）石蒜属植物均为异面叶,叶肉组织有一定的栅栏组织和海绵组织分化,但二者的厚度、叶肉中所占比例及栅栏组织的细胞层数在种间有一定的差异;（3）海绵组织发达、具有大而明显的薄壁细胞或细胞裂溶后形成空腔（分泌腔或气腔）;（4）叶片中维管束数目大多为奇数,叶脉维管束鞘由薄壁细胞组成;（5）石蒜属植物横切面上叶缘的形状分为圆弧形和楔形两种类型。石蒜属植物叶的解剖结构具有许多相似特征;同时又具有一定的种间差异,可为石蒜属槽物的种间关系和开发利用提供有价值的信息。     

太白山5种杜鹃属植物叶片光合特性及解剖结构的生态适应性研究

对分布于太白山海拔2 000～3 700 m的5种杜鹃属植物的叶片光合特性和形态解剖结构进行了研究.结果显示:头花杜鹃分布于高山灌丛,光饱和点、光补偿点高,强光适应性好,耐荫性差;爬枇杷分布于3 000～3 400 m的太白红杉林下,光饱和点较低,光补偿点最高,利用强光能力较弱,生态幅较窄;金背杜鹃、药枇杷、秀雅杜鹃分布于2 000～3 200 m的红桦、牛皮桦林下,光补偿点低,耐荫性强,生态幅宽.在形态结构上,5种杜鹃的栅海组织比均远小于1,属耐荫植物.头花杜鹃叶表密被鳞片,栅栏组织发达,通气组织发达;爬枇杷栅栏组织发达,排列紧密;金背杜鹃叶下表皮密被毛,气孔密度最高,海绵组织排列疏松;秀雅杜鹃叶上下表皮密被鳞片;药枇杷的栅栏组织厚度最小,栅海组织比最低.研究表明,5种杜鹃属植物叶片结构特征的形成是对生境条件长期适应的结果.     

新疆10种沙生植物旱生结构的解剖学研究

新疆１０种沙生植物的形态解剖研究表明,它们为适应沙生环境形态结构发生变化。叶器官的形态呈三种类型：叶片退化成膜质或鳞片状,而由同化枝执行光合功能;叶片上下都具栅栏组织,表皮角质膜厚,表皮毛发达,气孔下陷,输导组织和机械组织都发达;叶片肉质化,叶肉组织不分化,贮水组织发达而输导组织不发达。轴器官中厚壁组织发达,围绕维管组织,维管组织内部也有发达的厚壁组织。根中普遍具有周皮,一些植物存在异常的维管组织,部分植物还具有粘液细胞或结晶。沙生植物形成各种旱生结构,以不同的方式适应沙生环境。     

石蒜属12 种植物叶片比较解剖学研究

 对石蒜属( Lycoris Herb. ) 12 种植物叶片的比较解剖学研究表明: (1) 石蒜属植物叶片横切面的端部、中部及基部的轮廓基本呈浅“W”或“V”字型, 有些种的表皮细胞上具有明显的尖刺状乳突; ( 2)石蒜属植物均为异面叶, 叶肉组织有一定的栅栏组织和海绵组织分化, 但二者的厚度、叶肉中所占比例及栅栏组织的细胞层数在种间有一定的差异; (3) 海绵组织发达、具有大而明显的薄壁细胞或细胞裂溶后形成空腔(分泌腔或气腔); (4) 叶片中维管束数目大多为奇数, 叶脉维管束鞘由薄壁细胞组成; (5) 石蒜属植物横切面上叶缘的形状分为圆弧形和楔形两种类型。石蒜属植物叶的解剖结构具有许多相似特征; 同时又具有一定的种间差异, 可为石蒜属植物的种间关系和开发利用提供有价值的信息。     

新疆四种补血草属植物叶片的解剖学研究

利用叶片离析法和石蜡切片法研究了补血草属4种植物叶片的形态结构。结果表明:(1)4种植物的叶片有许多共同的结构适应特征,表皮细胞排列紧密,表面有厚的角质层;气孔类型均为不等型,气孔位置为平置或略微下陷;上下表皮还具有多细胞构成的盐腺;栅栏组织发达,多为等面叶;存在粘液细胞和单宁细胞;机械组织和维管组织都不发达等。(2)不同种间有不同的结构适应特征,如表皮细胞的形状、大小、垂周壁饰样,气孔密度,盐腺密度,叶片厚度和栅栏组织厚度等。通过叶的结构特征反映出盐生植物与旱生植物的不同。     

安徽产两种山罗花属植物及其居群叶的微形态比较

利用离析法、扫描电镜和石蜡切片法对安徽产2种3居群山罗花属植物的叶进行了微形态比较研究,结果表明：该属植物叶表皮细胞形状为不规则形,垂周壁呈波状、深波状至重波状;表皮细胞内含叶绿体;角质层具条状纹饰;表皮上有表皮毛和腺毛分布,扫描电镜下表皮毛具瘤状突起的纹饰;栅栏组织只有1层,排列比较疏松,海绵组织有发达的胞间隙;气孔器多为无规则型,极少数仅有一个副卫细胞,仅分布于下表皮,扫描电镜下气孔外拱盖内缘近光滑或浅波状。2种植物在垂周壁式样、表皮毛密度、气孔器长宽比、栅栏组织和海绵组织的厚度比以及中脉的结构特征等具有明显的差异,而山罗花3居群间的差异不明显。     

两种寄生植物营养器官结构的研究

研究了槲寄生和北桑寄生茎、叶和吸器的结构,结果表明：槲寄生三年生茎稍肉质化,无周皮,有极厚的角质层;皮层有7个纤维束,薄壁组织发达;木质部中亦含有大量薄壁组织;韧皮部发达;簇晶及大量粘稠物质在茎中广泛分布。槲寄生叶肉质化,厚1.44 mm; 角质层发达,厚度为9.06～13.4 μm;叶肉无栅栏组织和海绵组织的分化。北桑寄生茎与正常木本植物茎的结构相似,木质部为典型的环孔材;韧皮部含有石细胞;髓部细胞壁厚,单纹孔明显。北桑寄生叶较薄,叶脉发达,无栅栏组织和海绵组织的分化。两种植物的吸器结构相似,由薄壁组织和螺纹导管组成,它们的螺纹导管长度相同,但槲寄生导管的直径是北桑寄生的2.5倍。     

大豆属Soja亚属不同进化型植物叶片演化结构研究

为了探讨大豆属(Glycine)Soja亚属植物的系统演化规律,采用石蜡切片法对产自吉林省的大豆属Soja亚属4种植物的叶片结构进行显微观察。结果显示,Soja亚属中的野生大豆(Glycine sojaSeib.et Zucc.)、半野生大豆(semi-wild soybean)、半栽培大豆(semi-cultured soybean)、栽培大豆(Glycine max(L.)Merrill.)叶片的部分结构特征差异显著;从野生大豆到栽培大豆,其叶片和主脉逐渐加厚、表皮毛数量增多,主脉维管束中导管分子列数增多且逐渐演化出异型维管束,栅栏组织层数逐渐增多,CTR(栅栏组织/叶片厚)和SR(海绵组织/叶片厚)值也有增高的趋势;栽培大豆栅栏组织最发达,已演化出4层栅栏组织细胞。大豆属Soja亚属4种植物(野生大豆、半野生大豆、半栽培大豆、栽培大豆)叶片间的解剖结构差异表现出明显的进化趋势。     

Neuroendocrine properties of macrophage migration inhibitory factor (MIF)

The cytokine macrophage migration inhibitory factor (MIF) is produced by neuroendocrine and immune tissues and possesses several features that allow it to be characterized as a neuroendocrine mediator. Its pro-inflammatory action and its pathogenic role in inflammatory diseases, such as septic shock, arthritis and other diseases, have clearly been demonstrated and may be based in part on neuroendocrine mechanisms. Macrophage migration inhibitory factor possesses glucocorticoid-antagonist properties within the immune system and participates in the regulation of several endocrine circuits. This review summarizes the current state of MIF research and focuses on MIF expression and function in nervous and endocrine tissues.     

MULTIPLE FORMS OF MONOAMINE OXIDASE IN DEVELOPING BRAIN: TISSUE AND SUBSTRATE SPECIFICITIES

Brains, hearts and livers from newborn and adult rats were assayed for monoamine oxidase activity using gel electrophoretic techniques. The results suggest that each of the tissues possesses multiple forms (isoenzymes) of monoamine oxidase and that these forms are different for the various tissues. Further, the forms of monoamine oxidase in the neonatal tissues differ from those in the corresponding adult tissue. These different forms of monoamine oxidase have different substrate specificities. Using 5-hydroxy[¹⁴C]tryptamine as substrate, we have demonstrated that the monoamine oxidase patterns appearing on the gel do indeed possess monoamine oxidase activity.     

Forced expression of murine IL-17E induces growth retardation, jaundice, a Th2-biased response, and multiorgan inflammation in mice.

IL-17 is a proinflammatory cytokine, and its in vivo expression induces neutrophilia in mice. IL-17E is a recently described member of an emerging family of IL-17-related cytokines. IL-17E has been shown to bind IL-17Rh1, a protein distantly related to the IL-17R, suggesting that IL-17E probably possesses unique biological functions. In this study, we have identified the murine ortholog of IL-17E and developed transgenic mice to characterize its actions in vivo. Biological consequences of overexpression of murine (m)IL-17E, both unique to IL-17E and similar to IL-17, were revealed. Exposure to mIL-17E resulted in a Th2-biased response, characterized by eosinophilia, increased serum IgE and IgG1, and a Th2 cytokine profile including elevated serum levels of IL-13 and IL-5 and elevated gene expression of IL-4, IL-5, IL-10, and IL-13 was observed in many tissues. Increased gene expression of IFN-gamma in several tissues and elevated serum TNF-alpha were also noted. In addition, IL-17E induces G-CSF production in vitro and mIL-17E-transgenic mice had increased serum G-CSF and exhibit neutrophilia, a property shared by IL-17. Moreover, exposure to mIL-17E elicited pathological changes in multiple tissues, particularly liver, heart, and lungs, characterized by mixed inflammatory cell infiltration, epithelial hyperplasia, and hypertrophy. Taken together, these findings suggest that IL-17E is a unique pleiotropic cytokine and may be an important mediator of inflammatory and immune responses.     

Comparative levels between enzymes of the glycolytic pathway from erythrocytes and somatic tissues of the chicken Gallus gallus domesticus

A comparative study on the glycolytic enzymes from chicken erythrocytes and somatic tissues has been carried out, the results being shown as active units per mg protein in supernatants of 1085, 12,100 and 106,000 g fractionated centrifugation. The profiles of the glycolytic enzymes have been analyzed in terms of their activity relative to hexokinase and as the ratios between pairs of enzymes bearing a product-substrate relationship. Chicken erythrocyte displays a very peculiar profile of glycolytic enzymes. It possesses a FruP2-activated pyruvate kinase of the L isoenzyme type, which does not seem to be the predominant isoenzyme together with the M type, the content in glycolytic enzymes being much lower than in the somatic tissues.     

Identification of a second major site for CD46 binding in the hemagglutinin protein from a laboratory strain of measles virus (MV): potential consequences for wild-type MV infection

Natural or wild-type (wt) measles virus (MV) infection in vivo which is restricted to humans and certain monkeys represents an enigma in terms of receptor usage. Although wt MV is known to use the protein SLAM (CD150) as a cell receptor, many human tissues, including respiratory epithelium in which the infection initiates, are SLAM negative. These tissues are CD46 positive, but wt MV strains, unlike vaccinal and laboratory MV strains, are not thought to use CD46 as a receptor. We have identified a novel CD46 binding site at residues S548 and F549, in the hemagglutinin (H) protein from a laboratory MV strain, which is also present in wt H proteins. Our results suggest that although wt MV interacts with SLAM with high affinity, it also possesses the capacity to interact with CD46 with low affinity.     

Partial purification and characterization of an aldohexose 1-P phosphatase from pig skeletal muscle

An enzyme with a molecular weight of 54,000 which possesses phosphatase activity acting on glucose 1-P, galactose 1-P and mannose 1-P has been partially purified and characterized from pig skeletal muscle. The enzyme is free of phosphoglucomutase and galactokinase activities, and it possesses a neutral optimum pH. Pi acts as an inhibitor; glucose, galactose and mannose do not produce any effect. Divalent cations are required for activity, Mg2+ being the most effective activator. Micromolar levels of fluoride and millimolar levels of chloride act as inhibitors; however, vanadate does not produce any effect. The enzyme may have an important role when galactose accumulates in tissues; for example, in galactosemic patients and in young animals ingesting high-galactose diets.     

Tissue-selective expression of alpha-dystrobrevin is determined by multiple promoters

alpha-Dystrobrevin, the mammalian orthologue of the Torpedo 87-kDa postsynaptic protein, is a dystrophin-associated and dystrophin-related protein. Knockout of the gene in the mouse results in muscular dystrophy. The control of the alpha-dystrobrevin gene in the various tissues is therefore of interest. Multiple dystrobrevin isoforms differing in their domain content are generated by alternative splicing of a single gene. The data presented here demonstrate that expression of alpha-dystrobrevin from three promoters, that are active in a tissue-selective manner, also plays a role in the function of the protein in different tissues. The most proximal promoter A is active in brain and to a lesser extent in lung, whereas the most distal promoter B, which possesses several Sp1 binding sites, is restricted to brain. Promoter C, which contains multiple consensus myogenic binding sites, is up-regulated during in vitro myoblast differentiation. Interestingly, the organization and the activity of the alpha-dystrobrevin promoters is reminiscent of those in the dystrophin gene. Taken together we suggest that the multipromoter system, distributed over a region of 270 kilobases at the 5'-end of the alpha-dystrobrevin gene, has been developed to allow the regulation of this gene in different cell types and/or different developmental stages.     

Wounding enhances expression of AtSUC3, a sucrose transporter from Arabidopsis sieve elements and sink tissues

The Arabidopsis AtSUC3 gene encodes a sucrose (Suc) transporter that differs in size and intron number from all other Arabidopsis Suc transport proteins. Each plant species analyzed so far possesses one transporter of this special type, and several functions have been discussed for these proteins, including the catalysis of transmembrane Suc transport, and also Suc sensing and regulation of other Suc transporters. Here, we show that the AtSUC3 protein is localized in the sieve elements of the Arabidopsis phloem and is not colocalized with the companion cell-specific AtSUC2 phloem loader. Even stronger AtSUC3 expression is observed in numerous sink cells and tissues, such as guard cells, trichomes, germinating pollen, root tips, the developing seed coat, or stipules. Moreover, AtSUC3 expression is strongly induced upon wounding of Arabidopsis tissue. The physiological role of AtSUC3 in these different cells and tissues is discussed.