Two LINE 1 repeats in rat

One LINE 1 repeat has been located 661 bp downstream from the last albumin exon and another approx. 10 kbp downstream from the last alpha-fetoprotein exon in the rat genomic DNA. The LINE 1 repeat following the albumin gene is truncated at its 5' end and is 1204 nucleotides long. The 5' end of the longer repeat downstream from the alpha-fetoprotein gene has not been determined. The two repeats have 95% homology with each other, with the exception of a short diverse 3' end sequence just preceding the putative polyadenylation signal.     

小麦间期集缩染色质的超微结构研究

本文以普通小麦(Triticum aestivum L.)根端分生组织为材料,在透射电镜下对间期细胞核内的集缩染色质的高层次结构进行了研究。在其中观察到直径约为20—25nm、50nm及110—120nm 的不同等级染色线,并且发现直径110—120nm 的染色线是由50nm 的染色线组成的,而直径约50nm 的染色线是由20—25nm 的染色线组成的。对这三个层次染色质结构之间的集缩方式进行了讨论。     

Regulation of gene expression in rat prostate by androgen and beta-adrenergic receptor pathways

Denervation of rat ventral prostate has been accomplished by excising prostatic tissue fragments and implanting them under the renal capsules of intact syngeneic rats. This resulted in a substantial reduction of expression of a major organ-specific secretory protein, prostatic binding protein (PBP). The depressed level of PBP and its subunits and mRNAs could be restored, however, to as much as 80% of control levels by the administration of a pharmacological dose of exogenous androgen, testosterone propionate (TP), and/or a beta-adrenergic agonist, isoproterenol (ISO). Furthermore, compared to ascorbate-treated controls, TP and ISO increased the synthesis of total cellular protein and PBP by the prostatic renal implants. TP and/or ISO also remodelled the luminal epithelial structure and elevated secretory functions. ISO alone had no effect, however, in castrated animals, indicating that androgen plays a dominant role in the restoration of tissue PBP content. Concomitant to increased PBP content and remodelling of prostatic histomorphology, androgen was also found to raise the depressed levels of beta 2-adrenergic and androgen receptors in the prostatic isografts maintained in intact hosts. In contrast, although an established rat prostatic epithelial cell line (NbE-1) contains high affinity androgen receptor, androgen failed to restore beta-adrenergic receptor as well as PBP content in this cultured cell line. These results, taken together, suggest that a tight coupling between androgen receptor and beta 2-adrenergic receptor pathways may be a prerequisite for PBP expression and functional differentiation in the rat ventral prostate gland.     

SC9-4和棕榈油的比较分析研究

SC_9-4是以植物油为原料研制成功的一种高速冷轧工艺润滑油。经武钢高速冷轧机轧制性能鉴定,它的高速轧制性能优于棕榈油。我们使用高效液相色谱比较分析鉴定了SC_9-4和棕榈油的甘油三酯组成。分析结果:SC_9-4:的主要甘油三酯是POP(42.8％)和PPP(14.6％),而棕榈油的主要甘油三酯是POP(31.3％)、POO(20.1％)、PLP(12.2％)和PLO(11.6％)。我们初步探讨甘油三酯组成与轧制性能关系认为,SC_9-4的高速轧制性能优于棕榈油,可能是和SC_9-4含PPP、PPS和PSS的含量(18.8％)高于棕榈油(9.9％)有关。     

植物单盐毒害和离子拮抗机理研究Ⅰ.单盐和混合盐对植物原生质体膜某些特性、超氧物歧化酶和过氧化氢酶活性的影响

单盐(KCl, CaCl_2或MgCl_2)和混合盐(KC_1+CaCl_2或KCl+MgCl_2)对植物原生质体完整率、存活率和膜透性等均有明显影响。K~+、Ca~(2+)或Mg~(2+)等单种阳离子明显降低原生质体膜完整率和存活率而增加其物质渗漏量,其中以单价阳离子K~+的影响为甚。上述单种阳离子还明显降低小麦幼叶超氧物歧化酶(SOD)和过氧化氢酶活性。只有由单价和二价阳离子组成的平衡混合盐才能使原生质体维持较高的完整率、存活率和较正常的膜透性.并能使细胞维持较高的SOD和过氧化氢酶活性。 认为单盐毒害机理可能是首先引起细胞膜发生不正常的膜相变或细胞累积较多的有害氧自由基,引起膜脂发生过氧化或脱酯化而破坏膜结构。在离子平衡混合盐作用下,膜系才能维持正常液晶相,具有较高活性的SOD和过氧化氢酶等生物保护性酶系是离子拮抗作用之原因。     

桂西壮族手皮纹的分析

本文对广西西部500例健康壮族大、中学生的手皮纹进行了观察分析,计算出各型指纹频率、指纹脊线总数、指纹频度指数、atd角度、a-b脊线数、τ距比、主线横向指数、皮纹花样出现率、掌褶纹出现率共九项基本参数,并将这些数值与汉族作了比较,桂西壮族的手纹与汉族既有相似之处,又有本民族的特点。     

Production and characterization of a monoclonal antibody cross-reactive with most group A trichothecenes

A monoclonal antibody cross-reactive with most group A trichothecenes was produced by fusion of P3/NS-1/1-AG4-1 myeloma cells with spleen cells isolated from a BALB/c mouse that had been immunized with 3-acetyl-neosolaniol-hemisuccinate conjugated to bovine serum albumin. One stable clone, H159B1D5, which produced monoclonal antibody that bound with both T-2 toxin and diacetoxyscirpenol (DAS) was obtained after subcloning. Enzyme-linked immunosorbent assay (ELISA) revealed that the antibody belongs to the immunoglobulin G1 (kappa chain) isotype and had binding constants of 2.81 x 10(9), 1.05 x 10(9), and 1.57 x 10(8) liters per mole for T-2 tetraol tetraacetate, T-2 toxin, and DAS, respectively. The relative cross-reactivities of the antibody with T-2 tetraol tetraacetate, T-2 toxin, and DAS were 200, 100, and 20, respectively, with tritiated T-2 toxin as the marker ligand. The relative cross-reactivities for the above toxins were 667, 100, and 73, respectively, with tritiated DAS as the marker ligand. No cross-reaction with HT-2 and deoxynivalenol triacetate was observed in either system. By using this monoclonal antibody, an indirect ELISA for analysis of T-2 toxin was also developed. The linear portion of the standard curve for analysis of T-2 toxin in each analysis by radioimmunoassay and ELISA was in the range of 0.1 to 2 ng and 0.05 to 1.0 ng, respectively.     

Effects of traces of rare earth elements on the protozoanBlepherisma and on mice

The growth of the protozoanBlepherisma is stimulated by Lanthanum (La) at concentrations as low as 0.32 ppm. In mice Yttrium (Y) and Ytterbium (Yb) are absorbed, accumulated, and metabolized. Both rare earth elements (RE) exhibit a high affinity for teeth and bones, accumulation occurs and metabolism is slow. In the livers of RE-exposed mice, concentrations are variable. The liver is apparently capable of absorbing and discharging RE in a manner depending on metabolic activity. The main route of discharge for ingested REs is the alimentary canal. Exposure of pregnant mice to RE leads to rapid placental transfer of RE; 14.1% of the total amount of RE administered was detected in newborn mice. Young, developing organisms appear to be especially susceptible to RE accumulation.     

Cross-reactivity of antibodies against T-2 with deepoxide T-2 toxin

Two types of antibodies raised against T-2 toxin, namely anti-T-2-HS-BSA and anti-3 -Ac -NEOS-HS -BSA, showed good cross-reactivity with deepoxy T-2 toxin. Our results indicate that the epoxide is not an important epitope for the production of antibody against T-2 toxin