Cornucoryphe schirmi n. gen. n. sp., an unusual conocoryphid trilobite from the Middle Cambrian of Spain

Cornucoryphe n. gen. from the Middle Cambrian of the Cantabrian Mountains and Aragón is a unicornianConocoryphe with pronounced alae.     

Immunolocalization of extensin and potato tuber lectin in carrot, tomato and potato

Tissue-specific expression of two members of the cell wall hydroxyproline-rich glycoprotein (HRGP) family, extensin and potato tuber lectin, was examined by immunolocalization at the light microscope level in various organs (leaves, stems, roots, fruit, tuber) of carrot ( Daucus carota cv. Thumbelina), tomato ( Lycopersicon esclentum cv. Pixie Hybrid II), and potato ( Solanum tuberosum cv. Kennebec). Extensin was prominently expressed in vascular tissue, particularly xylem and also phloem, although virtually all cells displayed some degree of staining which varied as a function of the tissue, organ, and plant under study. Antibodies against potato tuber lectin (PTL) displayed a localization pattern similar to that observed for extensin; notably PTL did not stain cambium but did stain epithelial cells lining secretory cavities. These distribution patterns are consistent with a role for extensin, and possibly PTL, in providing mechanical support in tissues subjected to compression or torsional stress imparted by vascular growth, or by similar stress brought about by transport of vascular fluids.     

自养黄杆菌合成羟基丁酸和羟基戊酸共聚体的发酵研究

采用本实验室从土壤中分离到的一株自养黄杆菌进行了羟基丁酸和羟基戊酸共聚体〔P(HB-co-HV)〕的发酵试验。实验结果表明,该菌株是自养黄杆菌葡萄糖运输突变株,可以葡萄糖、果糖、蔗糖、麦芽糖、乙酸盐、乳酸盐和苹果酸盐作为唯一碳源,尤以葡萄糖和果糖效果最佳。硫酸铵、氯化铵和蛋白胨等不同氮源不影响其生长,却影响细胞中P(HB-co-HV)的含量和P(HB-co-HV)中HV/HB的比例。应用两阶段控制方式,经42h的补料分批发酵,细胞浓度达34.9g·L~(-1),P(HB-co-HV)浓度达25.28g·L~(-1)。细胞和P(HB-co-HV)生产速率系数分别为0.83g·L~(-1)”·h~(-1)和0.61g·L~(-1)·h~(-1)。以基质为基准的细胞得率系数(Yx/s)、产物得率系数(Yp/s)和以干细胞为基准的产物得率系数(Yp/x)分别为0.283(g/g)、0.174(g/g)和0.73(g/g)。改变培养基中碳氮源组分可将P(HB-co-HV)中HB的含量调节在24％～78％之间。     

15N resonance assignments of oxidized and reducedChromatium vinosum high-potential iron protein

The¹⁵N resonances in reduced and oxidizedChromatium vinosum high-potential iron protein have been assigned by use of¹H-¹H COSY spectra and¹H-¹⁵N HMQC, HMQC-COSY, and HMQC-NOESY spectra. Unambiguous assignment of 70 of 85 backbone¹⁵N resonances in the reduced protein and 62 of 85 resonances in the oxidized protein are made, as are 12 of 21 side-chain¹⁵N resonances.     

植物血细胞凝集素对小鼠脾脏淋巴细胞γ－谷氨酰基转肽酶活性的影响

本文就植物血细胞凝集素（ＰＨＡ）作用的不同时间对小鼠脾脏淋巴细胞γ－谷氨酰基转肽酶（γ－ＧＴ）活性的影响进行了观察。结果表明,脾脏淋巴细胞转化率随给予ＰＨＡ时间的延长而上升,对照组＜２４ｈ组＜４８ｈ组＜７２ｈ组;淋巴细胞γ－ＧＴ活性于２４ｈ明显强于对照组（Ｐ＜０．００１）,随着ＰＨＡ作用时间的延长其γ－ＧＴ活性逐渐下降,即４８ｈ组与对照组已无显著差异,而７２ｈ组却低于对照组（Ｐ＜０．００１）。可见ＰＨＡ在小鼠体内对γ－ＧＴ活性有很大影响。     

猴B病毒相关抗体及B病毒抗体检测的比较研究

本文比较了用ＨＳＶ－１（ＩＥＡ）和Ｂ病毒（ＩＦＡ）的方法检查猴Ｂ病毒相关抗体和Ｂ病毒抗体的结果：ＩＥＡ检查出的Ｂ病毒相关抗体阴性猴,经ＩＦＡ检查,全部为Ｂ病毒抗体阴性。用ＩＦＡ检查了Ｂ病毒相关抗体阴性的恒河猴,在单笼隔离饲养六个月后,有９８．３％的动物Ｂ病毒相关抗体仍为阴性,表明ＩＲＡ的阴性结果有较好的一致性。本文讨论了建立无Ｂ病毒感染猴群的可行性。     

人粒细胞集落刺激因子（hG－CSF）cDNA3′－UTR对其表达的影响

利用人粒细胞集落刺激因子（ｈＧ－ＣＳＦ）ｃＤＮＡ３′端非翻译区（３′－ＵＴＲ）中存在的ＤｒａⅠ酶切位点,通过部分酶切与完全酶切,删除３′－ＵＴＲ不同长度,构建了四种ｈＧ－ＣＳＦｃＤＮＡ瞬时重组表达质粒。转染ＣＯＳ－７细胞后,生物活性测定结果提示,ｈＧ－ＣＳＦｃＤＮＡ３′－ＵＴＲ对其表达起负调控作用,其关键性序列位于紧接终止密码子ＴＧＡ下游的６５ｂｐ范围内,３′－ＵＴＲ对ｈＧ－ＣＳＦｃＤＮＡ表达的影响与转录水平的差别有一定关系。     

大瓶螺碱性磷酸酶的分离纯化及部分性质研究

大瓶螺碱性磷酸酶的分离纯化及部分性质研究李清漪,曾和期（西南师范大学生物系,重庆６３０７１５）碱性磷酸酶（ＥＣ３．１．３．１,简称ＡＫＰ）是广泛存在于动物组织中的水解酶。对软体动物中ＡＫＰ的研究仅有少数报道［１,２］,对属于单壳贝类的水生食用螺──大...     

人鼻咽癌细胞基因组中瘤基因Ha－ras－1的Dnase Ⅰ超敏感位点的初步研究

ＤＮａｓｅⅠ超敏感位点的研究能够发现潜在的调控基因转录活化的位点,比较正常人外周血有核细胞,淋巴瘤细胞株Ｐ３ＨＲ１和人鼻咽癌低分化磷癌细胞株ＨＯｎＥ１和ＨＮＥ２中Ｈａ－ｒａｓ－１瘤基因的ＤＮａｓｅⅠ超敏感位点发现,只有ＨＯＮＥ１和ＨＮＥ２细胞基因组中存在一个ＤＮａｓｅⅠ超敏感位点,位于第一个外显子上游０．３７ｋｂ处,上述结果提示正常白细胞和Ｐ３ＨＲ１细胞中Ｈａ－ｒａｓ－１基因处于失活状态,而在鼻咽癌细胞基因组中则处于活化状态,它的活化可能与０．３７ｋｂ处的ＤＮＡ序列有密切的关系。     

Oxytocin induced a biphasic increase in the intracellular Ca2+ concentration of porcine myometrial cells: Participation of a pertussis toxin—insensitive G-protein,inositol 1,4,5-trisphosphate—sensitive Ca2+ pool,and Ca2+ channels

This study investigated the underlying mechanisms of oxytocin (OT)-induced increases in intracellular Ca²⁺ concentrations ([Ca²⁺]_i) in acutely dispersed myometrial cells from prepartum sows. A dosedependent increase in [Ca²⁺]_i was induced by OT (0.1 nM to 1 μM) in the presence and absence of extracellular Ca²⁺ ([Ca²⁺]_e). [Ca²⁺]_i was elevated by OT in a biphasic pattern, with a spike followed by a sustained plateau in the presence of [Ca²⁺]_e. However, in the absence of [Ca²⁺]_e, the [Ca²⁺]_i response to OT became monophasic with a lower amplitude and no plateau, and this monophasic increase was abolished by pretreatment with ionomycin, a Ca²⁺ ionophore. Administration of OT (1 μM) for 15 sec increased inositol 1,4,5-trisphosphate (IP₃) formation by 61%. Pretreatment with pertussis toxin (PTX, 1 μg/ml) for 2 hr failed to alter the OT-induced increase in [Ca²⁺]_i and IP₃ formation. U-73122 (30 nM to 3 μM), a phospholipase C (PLC) inhibitor, depressed the rise in [Ca²⁺]_i by OT dose dependently. U-73122 (3 μM) also abolished the OT-induced IP₃ formation. Thapsigargin (2 μM), an inhibitor of Ca²⁺-ATPase in the endoplasmic reticulum, did not increase [Ca²⁺]_i. However, it did time-dependently inhibit the OT-induced increase in [Ca²⁺]_i. Nimodipine (1 μM), a Voltage-dependent Ca²⁺ channel (VDCC) blocker, inhibited the OT-induced plateau by 26%. La³⁺ (1 μM), a nonspecific Ca²⁺ channel blocker, abrogated the OT-induced plateau. In whole-cell patch-clamp studies used to evaluate VDCC activities, OT (0.1 μM) increased Ca²⁺ Current (I_ca) by 40% with no apparent changes in the current-voltage relationship. The OT-induced increase in I_ca reached the maximum in 5 min, and the increase was abolished by nimodipine (1 μM). These results suggested that (1) activation of OT receptors in porcine myometrium evokes a cascade in the PTX-insensitive G-protein–PLC-IP₃ signal transduction, resulting in an increase in [Ca²⁺]_i; (2) the OT-induced increase in [Ca²⁺]_i is characterized by a biphasic pattern, in which the spike is predominately contributed by the intracellular Ca²⁺ release from the IP₃-sensitive pool, and to a lesser extent by Ca²⁺ influx, whereas the plateau is from increased Ca²⁺ influx; and (3) the influx is via VDCC and receptor-operated Ca²⁺ channels. © 1995 Wiley-Liss, Inc.