Selection of antibiotic-resistant mutants with enhanced isoamylase activity in Pseudomonas amyloderamosa

Summary Isoamylase-hyperproducing strains of Pseudomonas amyloderamosa were bred by mutagenesis with UV light and N-methyl-N-nitro-N-nitrosoguanidine (NTG). The selection criterion for such strains was based on the formation of large turbid zones around the bacterial colonies in agar medium containing antibiotics and 1% waxy corn starch. Mutant WN6410 was obtained by treating P. amyloderamosa JD210 with five cycles of 1 × 10⁴ J UV light and one cycle of NTG. P. amyloderamosa WN6410 had 22-fold increase in isoamylase activity when compared to wild-type strain SB15 and the maximal enzyme activity, 5,100 U/ml, could be achieved within 48 h in 2.5 L fed-batch fermentation.     

罕见的46，X，inv(Xq)伴原发闭经一例

X染色体数目及结构异常是原发性闭经的重要原因。在各类X染色体结构异常中,未见有关X染色体长臂的臂内倒位方面的报道。我室在1555例(男832例,女723例)染色体检查的患者中发现了一例,现予报告。     

金粟兰科的起源,演化及其分布

本文利用形态解剖,孢粉学及化石资料,讨论了金粟兰科的系统;并对其起源,演化和现代分布格局形成等问题做了合理推测,主要结果如下：（１）Ｓａｒｃａｎｄｒａ和Ｃｈｌｏｒａｎｔｈｕｓ的亲缘关系最接近,而Ａｓｃａｒｉｎａ和Ｈｅｄｙｏｓｍｕｍ的系统位置最靠近。Ｓａｒｃａｎｄｒａ是金粟兰科中最原始的属,而Ｈｅｄｙｏｓｍｕｍ则是最进化的属。（２）金粟兰科可能于白垩纪最早期起源于木质部无导管的,具简单两性虫媒花的祖     

不同钾水平对钾饥饿墨兰碳水化合物和蛋白质含量的影响

墨兰（Ｃｙｍｂｉｄｉｕｍｓｉｎｅｎｓｅ（Ａｎｄｒ．）Ｗｉｌｌｄ）植株经过钾饥饿后,无上栽培于不同钾浓度的培养液中．随着钾浓度的升高（５ｍｍｏｌ／Ｌ）,体内可溶性糖、淀粉、纤维素和蛋白质含量比对照分别增加１２５、１１７、１２７和４１％,而还原糖和游离氨基酸含量则比对照分别下降４４％和２４％．假球茎是贮藏还原糖、可溶性糖、淀粉、游离氨基酸和蛋白质的主要器官,叶片是纤维素最多的器官．钾供应充足时,叶片丙酮酸激酶活性明显加强（比对照强１５倍）,而硝酸还原酶活性也加强（比对照强０．８倍）．本文对钾促进墨兰生长发育和抗病等原因加以讨论．并初步提出诊断墨兰体内钾状况的三种生理指标．     

降血脂药物（DEHP）对酰基CoA氧化酶基因反式作用因子的影响

从对照和用ＤＥＨＰ处理的大鼠肝脏提取核蛋白,以含酰基ＣｏＡ氧化酶（ＡＯＸ）基因表达调控部位的ＤＮＡ片段和该基因的不同蛋白结合位点的ＤＮＡ片段作为核蛋白结合反应的探针,通过凝胶电泳迁移率改变实验和Ｓｏｕｔｈｗｅｓｔｅｒｎ印迹分析检查了ＤＥＨＰ对ＡＯＸ基因反式作用因子的影响。结果表明,降血脂药物ＤＥＨＰ可显著增加ＡＯＸ基因反式作用因子的含量和（或）与基因的结合活性,在转录水平上促进基因的表达。     

Inhibition of thyrotropin-stimulated DNA synthesis by microinjection of inhibitors of cellular Ras and cyclic AMP-dependent protein kinase.

Microinjection of a dominant interfering mutant of Ras (N17 Ras) caused a significant reduction in thyrotropin (thyroid-stimulating hormone [TSH])-stimulated DNA synthesis in rat thyroid cells. A similar reduction was observed following injection of the heat-stable protein kinase inhibitor of the cyclic AMP-dependent protein kinase. Coinjection of both inhibitors almost completely abolished TSH-induced DNA synthesis. In contrast to TSH, overexpression of cellular Ras protein did not stimulate the expression of a cyclic AMP response element-regulated reporter gene. Similarly, injection of N17 Ras had no effect on TSH-stimulated reporter gene expression. Moreover, overexpression of cellular Ras protein stimulated similar levels of DNA synthesis in the presence or absence of the heat-stable protein kinase inhibitor. Together, these results suggest that in Wistar rat thyroid cells, a full mitogenic response to TSH requires both Ras and cyclic APK-dependent protein kinase.     

在中国壮族家系中发现的一例-α~T/-α~Q复合β~0β~0珠蛋白基因型

本文报道在我国广西隆林壮族中发现一个罕見的HbQ复合α,β地中海贫血家系。先证者女,18岁,贫血面容,肝脾肿大。化学结构分析确证本Hb变异体为HbQ Thailand[α74(EF3)Asp→His]。血红蛋白组成以及α和β珠蛋白基因分析结果表明,先证者的珠蛋白基因型为-α~Q/-α~T复合β°/β°(IVSI-1G→T/Codon17A→T);先证者父的基因型为-‘α~Q/-复合β~O/β~A(IVSI-1G→T/β~A);先证母的基因型为-α~T/αα复合β~O/β~A(Codon17A→T/β~A)。     

岭南垛基果林湿地土壤碳组分特征

岭南垛基果林湿地是珠三角地区典型的湿地类型之一,其对土壤碳汇的贡献值得关注。为探讨果林种植类型对土壤有机碳的影响,对广州垛基果林湿地内种植黄皮(Clausenalansium)(HP),龙眼(Dimocarpuslongan)(LY)、杨桃(Averrhoa carambola)(YT),龙眼和黄皮间种(LH),杨桃、龙眼和黄皮间种(YLH)共5种种植类型下的表层(0～20 cm)土壤碳组分进行研究。结果表明,不同的植被类型对土壤的总有机碳(SOC)、可溶性有机碳(DOC)、微生物生物量碳(MBC)、易氧化有机碳(ROC)、惰性碳(NLC)含量都有影响,LY的SOC含量最高(22.6 g/kg),显著高于YLH (P<0.05),且NLC含量显著高于LH和YLH (P<0.05)。NLC含量与土壤养分呈正相关,与土壤容重呈负相关。YT的MBC含量显著高于LY、HP、LH (P<0.05),且MBC/SOC显著高于HP、LY(P<0.05)。YLH模式下,土壤DOC含量和DOC/SOC显著高于其他植被类型(P<0.05)。LH的ROC/SOC显著高于HP和L...