油凝胶剂──G－1的合成

油凝胶剂──Ｇ－１的合成李忠义（大连理工大学化工学院１１６０１２）关键词：凝胶作用；酰化；谷氨酸／油凝胶剂，Ｎ－月桂酰谷氨酸分类号：Ｏ６２３．７３６；Ｘ７４长碳链脂酸氨基酸的酸胺类、酯类化合物具有能使动、植物油，矿物油和非极性、极性小的且在水中溶解度...     

SLAM (CDw150) is a cellular receptor for measles virus

Measles virus continues to be a major killer of children, claiming roughly one million lives a year. Measles virus infection causes profound immunosuppression, which makes measles patients susceptible to secondary infections accounting for high morbidity and mortality. The Edmonston strain of measles virus, and vaccine strains derived from it, use as a cellular receptor human CD46 (refs 3, 4), which is expressed on all nucleated cells; however, most clinical isolates of measles virus cannot use CD46 as a receptor. Here we show that human SLAM (signalling lymphocyte-activation molecule; also known as CDw150), a recently discovered membrane glycoprotein expressed on some T and B cells, is a cellular receptor for measles virus, including the Edmonston strain. Transfection with a human SLAM complementary DNA enables non-susceptible cell lines to bind measles virus, support measles virus replication and develop cytopathic effects. The distribution of SLAM on various cell lines is consistent with their susceptibility to clinical isolates of measles virus. The identification of SLAM as a receptor for measles virus opens the way to a better understanding of the pathogenesis of measles virus infection, especially the immunosuppression induced by measles virus.     

Molecular structure of r(GCG)d(TATACGC): a DNA--RNA hybrid helix joined to double helical DNA

The molecule r(GCG)d(TATACGC) is self-complementary and forms two DNA--RNA hybrid segments surrounding a central region of double helical DNA; its molecular structure has been solved by X-ray analysis. All three parts of the molecule adopt a conformation which is close to that seen in the 11-fold RNA double helix. The conformation of the ribonucleotides is partly determined by water molecules bridging between the ribose O2' hydroxyl group and cytosine O2. The hybrid-DNA duplex junction contains no structural discontinuities. However, the central DNA TATA sequence has some structural irregularities.     

毛木耳油疤病病原菌的生长条件研究

对毛木耳油疤病病原菌新种毛木耳柱霉(Scytalidium auricola W.H.Peng)的生物学特性研究结果显示,在5℃～35℃范围内,随着温度升高,菌丝生长速度逐渐加快,最适温度范围为25℃～30℃;在pH 4～12范围内,随着pH升高菌丝生长速度逐渐降低,菌株具有嗜酸的特性,在pH 4～5时生长速度最快;毛木耳柱霉对碳源、氮源的利用能力较强,可广泛利用各类单糖、双糖和多糖,以及多种铵态氮和氨基酸;光照对菌丝生长和孢子形成具有促进作用.适当降低菌袋培养温度和遮光培养有利于降低病害发生.     

The SIL gene is required for mouse embryonic axial development and left-right specification.

The establishment of the main body axis and the determination of left-right asymmetry are fundamental aspects of vertebrate embryonic development. A link between these processes has been revealed by the frequent finding of midline defects in humans with left-right anomalies. This association is also seen in a number of mutations in mouse and zebrafish, and in experimentally manipulated Xenopus embryos. However, the severity of laterality defects accompanying abnormal midline development varies, and the molecular basis for this variation is unknown. Here we show that mouse embryos lacking the early-response gene SIL have axial midline defects, a block in midline Sonic hedgehog (Shh) signalling and randomized cardiac looping. Comparison with Shh mutant embryos, which have axial defects but normal cardiac looping, indicates that the consequences of abnormal midline development for left-right patterning depend on the time of onset, duration and severity of disruption of the normal asymmetric patterns of expression of nodal, lefty-2 and Pitx2.     

Mal (MyD88-adapter-like) is required for Toll-like receptor-4 signal transduction.

The recognition of microbial pathogens by the innate immune system involves Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns. Different TLRs recognize different pathogen-associated molecular patterns, with TLR-4 mediating the response to lipopolysaccharide from Gram-negative bacteria. All TLRs have a Toll/IL-1 receptor (TIR) domain, which is responsible for signal transduction. MyD88 is one such protein that contains a TIR domain. It acts as an adapter, being involved in TLR-2, TLR-4 and TLR-9 signalling; however, our understanding of how TLR-4 signals is incomplete. Here we describe a protein, Mal (MyD88-adapter-like), which joins MyD88 as a cytoplasmic TIR-domain-containing protein in the human genome. Mal activates NF-kappaB, Jun amino-terminal kinase and extracellular signal-regulated kinase-1 and -2. Mal can form homodimers and can also form heterodimers with MyD88. Activation of NF-kappaB by Mal requires IRAK-2, but not IRAK, whereas MyD88 requires both IRAKs. Mal associates with IRAK-2 by means of its TIR domain. A dominant negative form of Mal inhibits NF-kappaB, which is activated by TLR-4 or lipopolysaccharide, but it does not inhibit NF-kappaB activation by IL-1RI or IL-18R. Mal associates with TLR-4. Mal is therefore an adapter in TLR-4 signal transduction.     

X-linkage of steroid sulphatase in the mouse is evidence for a functional Y-linked allele

In the human there is an X-linked gene affecting steroid sulphatase (STS) activity which, when deficient, is associated with X-linked congenital ichthyosis. The gene (STS) is located on the distal tip of the short arm and is only partially inactivated when it is on the inactive X-chromosome. In the mouse, the genetics of STS are not clear; the results of one study using XX:X0 oocyte comparisons indicated X-linkage, but three other studies using STS variants have produced segregation data compatible with autosomal linkage of murine STS. Here we present the results of STS assays of crosses of deficient C3H/An male mice to normal X0 animals which demonstrate X-linkage of STS in the mouse and indirectly indicate the existence of a functional STS allele on the Y-chromosome which undergoes obligatory recombination during meiosis with the X-linked allele.     

Conservation of cytoplasmic poly (A)-containing RNA in mouse and rat.

By comparing the melting temperature of DNA-DNA duplexes between related species, it is shown that total single-copy DNA evolves at a faster rate that DNA which is transcribed into poly (A)-containing RNA. Such a comparison suggests that at least 70% of rat single-copy DNA does not code for protein.     

Peripheral SMN restoration is essential for long-term rescue of a severe spinal muscular atrophy mouse model

Spinal muscular atrophy (SMA) is a motor neuron disease and the leading genetic cause of infant mortality; it results from loss-of-function mutations in the survival motor neuron 1 (SMN1) gene. Humans have a paralogue, SMN2, whose exon 7 is predominantly skipped, but the limited amount of functional, full-length SMN protein expressed from SMN2 cannot fully compensate for a lack of SMN1. SMN is important for the biogenesis of spliceosomal small nuclear ribonucleoprotein particles, but downstream splicing targets involved in pathogenesis remain elusive. There is no effective SMA treatment, but SMN restoration in spinal cord motor neurons is thought to be necessary and sufficient. Non-central nervous system (CNS) pathologies, including cardiovascular defects, were recently reported in severe SMA mouse models and patients, reflecting autonomic dysfunction or direct effects in cardiac tissues. Here we compared systemic versus CNS restoration of SMN in a severe mouse model. We used an antisense oligonucleotide (ASO), ASO-10-27, that effectively corrects SMN2 splicing and restores SMN expression in motor neurons after intracerebroventricular injection. Systemic administration of ASO-10-27 to neonates robustly rescued severe SMA mice, much more effectively than intracerebroventricular administration; subcutaneous injections extended the median lifespan by 25 fold. Furthermore, neonatal SMA mice had decreased hepatic Igfals expression, leading to a pronounced reduction in circulating insulin-like growth factor 1 (IGF1), and ASO-10-27 treatment restored IGF1 to normal levels. These results suggest that the liver is important in SMA pathogenesis, underscoring the importance of SMN in peripheral tissues, and demonstrate the efficacy of a promising drug candidate.     

Poly(ADP-ribose) is required for spindle assembly and structure

The mitotic spindle is typically thought of as an array of microtubules, microtubule-associated proteins and motors that self-organizes to align and segregate chromosomes. The major spindle components consist of proteins and DNA, the primary structural elements of the spindle. Other macromolecules including RNA and lipids also associate with spindles, but their spindle function, if any, is unknown. Poly(ADP-ribose) (PAR) is a large, branched, negatively charged polymeric macromolecule whose polymerization onto acceptor proteins is catalysed by a family of poly(ADP-ribose) polymerases (PARPs). Several PARPs localize to the spindle in vertebrate cells, suggesting that PARPs and/or PAR have a role in spindle function. Here we show that PAR is enriched in the spindle and is required for spindle function--PAR hydrolysis or perturbation leads to rapid disruption of spindle structure, and hydrolysis during spindle assembly blocks the formation of bipolar spindles. PAR exhibits localization dynamics that differ from known spindle proteins and are consistent with a low rate of turnover in the spindle. Thus, PAR is a non-proteinaceous, non-chromosomal component of the spindle required for bipolar spindle assembly and function.     

cDNA sequence of human apolipoprotein(a) is homologous to plasminogen

Lipoprotein(a) is an LDL-like lipoprotein whose concentration in plasma is correlated with atherosclerosis. The characteristic protein component of lipoprotein(a) is apolipoprotein(a) which is disulphide-linked to apolipoprotein B-100. Sequencing of cloned human apolipoprotein(a) complementary DNA shows that it is very similar to human plasminogen. It contains a serine protease domain and two types of plasminogen-like kringle domains, one of which is present in 37 copies.     

Smooth muscle alpha-action is a transformation-sensitive marker for mouse NIH 3T3 and Rat-2 cells

Heteroploid mouse NIH 3T3 fibroblasts and several rat fibroblast strains (Rat-1, Rat-2 and REF-52) are cell lines of special interest in the field of carcinogenesis because of their extensive use as normal cells in transformation assays for putative cancer-causing genes. Exposure of these cells to carcinogenic chemicals or oncogenic DNA produces anchorage-independent cells with retracted cytoplasms that lack actin cables. All human fibroblast strains, normal and transformed, synthesize two electrophoretic forms of actin (beta- and gamma-actin). In contrast, we discovered that early-passage mouse and rat strains synthesize abundant amounts of each of the three electrophoretic forms of actin (alpha-, beta- and gamma-actin) but mouse and rat cancer cells express only beta- and gamma-actins. We now show that in NIH 3T3 and Rat-2 fibroblasts a third actin, the smooth muscle alpha isoform, is abundantly co-expressed with beta- and gamma-actin. In every instance tested following transformation to tumorigenicity, the accumulation of alpha-actin messenger RNA and alpha-actin synthesis was greatly inhibited. Shutdown of alpha-actin expression thus appears to be a reproducible transformation-sensitive marker in rodent fibroblasts.     

A cellular oncogene (c-Ki-ras) is amplified, overexpressed, and located within karyotypic abnormalities in mouse adrenocortical tumour cells

The cellular oncogene c-Ki-ras is amplified 30- to 60-fold in cells of the mouse adrenocortical tumour Y1. The amplified oncogene is located in double minute chromosomes and in a homogeneously staining chromosomal region, common karyotypical anomalies of tumour cells. The amounts of c-Ki-ras specific mRNA and of the protein (p21) encoded by the amplified gene are correspondingly elevated. Amplification and enhanced expression of cellular oncogenes may contribute to the genesis and/or maintenance of at least some naturally occurring tumours.     

硒化蓖麻酸对肿瘤细胞DNA合成的影响

大量的研究报道表明,克山病、大骨节病与缺硒有关,多种肿瘤的发生率也与周围环境硒含量呈负相关,说明微量元素硒具有多种生物学功能.补硒能预防并抑制肿瘤发生和发展;自60年代起,就有关于不饱和脂肪酸抗肿瘤的报道.笔者将硒与一种不饱和脂肪酸——蓖麻酸共价结合,使之形成硒化蓖麻酸,并对其体内外抗肿瘤活性进行了研究,结果表明:硒化蓖麻酸具有较强的抗肿瘤活性.其作用机理及对肿瘤