Influences of medium consistency and shoot density on in vitro shoot proliferation of Populus alba × P. grandidentata

The in vitro shoot proliferation of Populus alba × P. grandidentata was affected by the medium consistency and shoot density, but not by three sizes of vessels. After 4 weeks of culture, the fresh weight and number of shoots per explant on liquid medium were significantly greater than those on agar-solidified medium. In particular, 3.2 shoots, 7 mm or longer per explant, were produced on liquid medium compared with 1.6 shoots per explant or agar-solidified medium. The fresh weight per explant after 4 weeks of culture on liquid medium and agar-solidified medium were 0.68 and 0.25 g, respectively. Increasing the number of shoots per vessel slowed the growth of the explants as measured by fresh weight and the number of shoots produced. There was little difference in the number of shoots produced between vessels with 1 or 2 shoots per vessel, but there were many fewer shoots produced when 3 shoots were placed in each vessel.Journal Paper No. J-11977 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project 2210.     

Typing of Nontypable Staphylococci by Lysogeny

Strains of coagulase-positive staphylococci which were nontypable with the routine typing set of phages could be typed by lysogeny with phage-propagating strains as indicators and with ultraviolet induction. About 10% of the strains could be typed without induction. About 36% of them could be typed by this method when ultraviolet irradiation was used as an inducing agent. The phage groups from which the majority of the nontypable staphylococci originated were easily identified by this method of typing.     

Islet-cell Carcinoma (Zollinger—Ellison Syndrome) with Fulminating Adrenocortical Hyperfunction and Hypokalemia

The production of ACTH-like material by tumours arising in non-endocrine tissue may initiate severe adrenocortical hyperfunction. The pathogenesis and clinical and laboratory features of Cushing''s syndrome associated with such tumours are characteristic. The autonomous production by the tumour of ACTH-like material cannot be suppressed by exogenous corticoids. The onset of clinical symptoms is rapid; muscle wasting, general weakness, thirst and peripheral edema predominate, and the classical signs of Cushing''s syndrome may be absent. High levels of plasma 17-hydroxycorticosteroids and urinary 17-hydroxycorticosteroids and 17-ketosteroids, usually with normal levels of urinary aldosterone, commonly occur. Hypokalemic alkalosis unresponsive to replacement therapy may cause death. In the case reported herein, the intriguing possibility exists that two hormone-like substances were produced by the primary growth and its metastases: one, ACTH-like, to account for the adrenal hyperplasia and Cushing''s syndrome; and another, gastrin-like, giving rise to the ulcerogenic diathesis.     

嗜冷和冷育微生物的研究 Ⅲ.地丝霉属一新种,光滑地丝霉

在研究食品冷库中嗜冷微生物区系时,获得很多冷育型真菌。地丝霉和金孢菌类在这些菌中占优势。其中一菌在PYE上于18℃培养14天,菌落白色,厚毡状,中央常有淡黄色渗出液滴,菌落直径33mm,背面浅黄褐色,有辐射沟纹,老后仍为白色。菌丝分隔,直径1.0—2.0μm。该菌有明显的分生孢子梗,直立,宽度1.0—2.0μm,长10—25(—35)μm,无色或淡黄色,分生孢子梗具分枝,由分枝产分生孢子。分生孢子无色或淡黄色,顶端者为梨形、倒卵形或楔状,间生者矩椭圆形或桶状,1.5—2.5×2.5—3.5(—4.0)μm,光滑、1—3成链。该菌生长温度范围为0—25℃,最适温度为18℃,30℃不生长。此菌产生果胶酶,但是不分解角朊。该菌从冷库中生霉的蒜苗上分离得。其特征与Carmichael(1962),Domsch等(1980)所订正的金孢菌属(Chrysosporium Corda)中各种,以及Sigler和Carmichael(1976),Oorschot(1980)所订正的地丝霉属(Geomyces Traaen)中各种均有显著的差异,而其性状符合地丝霉属的特征集要。故命名为光滑地丝霉Geomyces laevis Z.Q.Li et Cui。模式:菌株AS 3.4605为模式菌株,保藏在中国科学院微生物研究所菌种保藏研究室;模式标本HMAS No.54875保存在该研究所真菌标本室。     

吗啡耐受大鼠心房心钠素的释放及其基因转录

本工作应用心钠素放射免疫测定和分子杂交技术首次发现,吗啡耐受大鼠血浆心钠素水平显著降低,心房内心钠素含量明显升高,同时心房内心钠素特异性mRNA水平也相应提高,提示在吗啡耐受时大鼠心房内心钠素的合成和贮存增加,释放减少。     

甘蔗幼叶切段培养中的体细胞胚胎发生

本文从形态学和组织学方面研究了甘蔗幼叶胚性愈伤组织发生及体细胞胚胎的形成过程。甘蔗幼叶片切段培养于含2.4—D1.5mg/1的MS培养基上,4—6天后切段开始形成愈伤组织,约10天后愈伤组织表面出现白色颗粒状结构。将含有白色颗粒状结构的愈伤组织转移至不含激素的培养基中,7—10天后可见有小植株长出。组织学和形态学观察表明,甘蔗离体再生植株是通过体细胞胚胎发生途径。     

Genetic Interactions between Reg1/Hex2 and Glc7, the Gene Encoding the Protein Phosphatase Type 1 Catalytic Subunit in Saccharomyces Cerevisiae

Mutations in GLC7, the gene encoding the type 1 protein phosphatase catalytic subunit, cause a variety of abberrant phenotypes in yeast, such as impaired glycogen synthesis and relief of glucose repression of the expression of some genes. Loss of function of the REG1/HEX2 gene, necessary for glucose repression of several genes, was found to suppress the glycogen-deficient phenotype of the glc7-1 allele. Deletion of REG1 in a wild-type background led to overaccumulation of glycogen as well as slow growth and an enlarged cell size. However, loss of REG1 did not suppress other phenotypes associated with GLC7 mutations, such as inability to sporulate or, in cells bearing the glc7(Y-170) allele, lack of growth at 14°. The effect of REG1 deletion on glycogen accumulation is not simply due to derepression of glucose-repressed genes, although it does require the presence of SNF1, which encodes a protein kinase essential for expression of glucose-repressed genes and for glycogen accumulation. We propose that REG1 has a role in controlling glycogen accumulation.     

正常小鼠高频心电图时域值和功率谱的研究

本文用南京新博公司生产的ＮＨＥ－１０００型心电高频信息检测分析仪研究了正常小鼠（昆明种）高频心电图（ＨＦ－ＥＣＧ）的时域值和ＱＲＳ波群的功率谱。主要结果如下（以正导为例,－Ｘ±ＳＤ）：心率６０３±８８次／ｍｉｎ（ｎ＝７４）;Ｐ－Ｒ间期相对较长。为３４．９±４．７ｍｓ（ｎ＝５８）,占心动周期的３４．９±４．９％,这与人类有很大的不同;ＱＲＳ波宽９．２±１．２ｍｓ,占心动周期的９．２±１．４％（ｎ＝７４）,这一结果与以前的文献报道相差较大。Ｔ波宽１０．３±３．２ｍｓ,占心动周期的１０．３±３．２％;Ｑ－Ｔ间期１９．４±３．２ｍｓ,占心动周期的１９．５±３．６％;ＱＲＳ波群峰－峰值（Ｖｐ－ｐ）为１．４５６±０．４８０ｍＶ;Ｔ波高０．３３６±０．１１５ｍＶ;７３只动物Ⅱ导联高频切迹总数只有３个,扭挫２６个。Ⅱ导联ＱＲＳ波群的功率谱特点：０—８０Ｈｚ的相对能量为４５．４８±１５．３２％;８０—２００Ｈｚ为４３．９７±９．９５％;２００—３００Ｈｚ为８．８９±７．３８％;３００—１０００Ｈｚ为１．６６±２．７４％。     

肝再生的调控及原癌基因表达

肝脏再生过程中受到多种体液因素的调控。肝细胞生长因子（ＨＧＦ）、肝刺激因子（ＨＳＳ）等对肝细胞有促分裂作用;转化生长因子β１（ＴＧＦβ１）等则具有抑制作用。此外,肝再生还需要去甲肾上腺素（ＮＥ）、胰岛素等辅助分裂原的存在,共同调节肝再生。肝细胞分裂增殖与原癌基因表达密切相关。肝细胞从静息期进入细胞周期,以及在整个细胞周期中,某些原癌基因有特征性的表达。