Central IL-1 differentially regulates peripheral IL-6 and TNF synthesis

Centrally given interleukin (IL)-1 is known to induce a rapid rises in blood IL-6. To extend this and to examine the mechanism by which this occurs, the effects of intracerebroventricular (icv) injection of human recombinant IL-1β on mRNA expression of IL-6 and tumour necrosis factor (TNF) in the spleen and liver were examined in rats. Icv injection of IL-1 produced a rapid rise of the tissue mRNA levels of IL-6 and TNF in both organs, prior to and/or in parallel with an increase in their serum levels. Pretreatment with chlorisondamine, a ganglionic blocking agent, inhibited the IL-6 responses, while it had little influence on the TNF responses. The results suggest that brain IL-1 induces peripheral production of IL-6, but not of TNF, through autonomic nervous system activation. Received 27 October 1997; received after revision 15 December 1997; accepted 12 January 1998     

Shrinkage Properties of Wool and Acrylic/Wool Plain Knitted Fabrics Treated with DC109

This paper examines the effects of shrink - resist treatment, washing cycle and fabric tightness on the shrinkage properties of plain knitted fabrics made from 100% wool, acrylic/wool (50/50) and acrylic/wool (70/30). It was found that shrinkages of both treated and untreated wool fabrics were negatively correlated to fabric tightness and exceeded the IWS shrinkage limits (5% in length and 8 % in area) after 2 - 5A washing cycle. The effect of tightness was not as obvious with acrylic/wool (A/W) fabrics, but the shrinkage was seen to increase with stages of washing cycle for untreated A/W fabrics with some exceeding IWS standard. By applying the DC 109 shrink - resist solvent treatment, it was identified that by with higher percentage of acrylic fibre blended with wool, shrinkage could be reduced considerably and within acceptable limits.     

Mutations in RECQL4 cause a subset of cases of Rothmund-Thomson syndrome.

Rothmund-Thomson syndrome (RTS; also known as poikiloderma congenitale) is a rare, autosomal recessive genetic disorder characterized by abnormalities in skin and skeleton, juvenile cataracts, premature ageing and a predisposition to neoplasia. Cytogenetic studies indicate that cells from affected patients show genomic instability often associated with chromosomal rearrangements causing an acquired somatic mosaicism. The gene(s) responsible for RTS remains unknown. The genes responsible for Werner and Bloom syndromes (WRN and BLM, respectively) have been identified as homologues of Escherichia coli RecQ, which encodes a DNA helicase that unwinds double-stranded DNA into single-stranded DNAs. Other eukaryotic homologues thus far identified are human RECQL, Saccharomyces cerevisiae SGS1 and Schizosaccharomyces pombe rqh1. We recently cloned two new human helicase genes, RECQL4 at 8q24.3 and RECQL5 at 17q25, which encode members of the RecQ helicase family. Here, we report that three RTS patients carried two types of compound heterozygous mutations in RECQL4. The fact that the mutated alleles were inherited from the parents in one affected family and were not found in ethnically matched controls suggests that mutation of RECQL4 at human chromosome 8q24.3 is responsible for at least some cases of RTS.     

QSHR中理化参数描述矩阵的病态参数剔除

在定量构效关系（ＱＳＡＲ）研究中各理化参数ｘｉ构成的描述矩阵，由于参数之间的相关性往往呈病态性或奇异性，由此获得的ＱＳＡＲ回归方程则不稳定，本文提出了一种新方法即病态指标剔除法：选择一个适当的临界值α∈（０，１），找出相关系数大于或等于该临界值所涉及的指标，剔除部分病态指标；再作逐步回归从而获得稳定优良的ＱＳＡＲ回归方程，可望在ＱＳＡＲ中广泛应用．     

面心立方萤石结构Ce_（1－x）Tb_xO_（2－δ）固溶体的氧缺欠研究

以热重量法研究了Ｃｅ１－ｘＴｂｘＯ２－δ（ｘ＝０．３，０．４，０．５）的缺氧分数６值．发现δ值随组成、环境氧分压和温度的不同在０．０６—０．４范围内变化．样品ＣＴ３０和ＣＴ５０于６５０℃以上温度在空气中失氧形成氧空位的反应热熔经估算分别为３６．０和４０．６ｋＪ／ｍｏｌ．研究表明，该数值主要由Ｔｂ离子的反应性决定，该复合氧化物中Ｃｅ离子的还原反应热焓显著小于它在纯ＣｅＯ２－δ中的数值．     

Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana

The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.     

Production of functional rat liver PSP protein in Escherichia coli

An efficient Escherichia coli expression system for the production of a perchloric acid-soluble protein (PSP) has been constructed. Complementary DNA encoding PSP was inserted into an inducible bacterial expression vector pGEX-4T-1. After the plasmid introduced into E. coli was expressed by isopropyl 1-thio-β-D-galactopyranoside (IPTG), the recombinant product was purified by glutathione-Sepharose 4B affinity chromatography. The purified product showed the expected NH₂-terminal sequence, but the translation inhibitory activity of this product was 10 times lower compared with that of authentic PSP isolated from rat liver. Received 8 October 1998; received after revision 6 November 1998; accepted 6 November 1998     

Sexual behavior mutants revisited: molecular and cellular basis of Drosophila mating

The study of Drosophila melanogaster by a combination of forward genetics with specific mutants, and reverse genetics, in which a given gene is expressed in an appropriate brain area to test its effect on behavior, provides a unique opportunity to explore the causal relationship between a particular gene, its function in the cell and the behavioral outcome at the organismic level. Enhanced male-to-male courtship has been shown to occur as a result of mutations in several different genes. For example, the Voila mutant exhibits intense GAL4 reporter expression in the tarsal gustatory sensilla, suggesting the importance of tapping by a male on the female abdomen with his forelegs. Feminization of parts of the antennal lobe and mushroom body by targeted expression of a female-determining gene transformer ⁺ (tra ⁺) drives the male to court other males. Mutations in the tra target gene fruitless (fru), which is expressed in the antennal lobe as well as the suboesophageal ganglion (the gustatory inputs are processed here), also induce homosexual courtship in males. These results suggest that sensory inputs mediated and/or processed by the tarsal receptors, suboesophageal ganglion, antennal lobe and mushroom body contribute to the regulation of male–female courtship. Mosaic analysis localized the neural center for male courtship behavior to the posterior dorsal brain, in which the sensory information processed by the aforementioned neural structures may be integrated. Another mosaic study mapped the neural center for female sexual behavior, as measured by her receptiveness to copulation, to the anterior dorsal brain. The issue as to how the mutations that reduce female sexual receptiveness, e.g. dissatisfaction (dsf), spinster (spin) and chaste (cht), affect the structure and/or function of this neural center deserves to be addressed urgently. Received 27 April 1999; received after revision 21 June 1999; accepted 8 July 1999     

The in vitro antiapoptotic effect of dehydroepiandrosterone sulfate in mouse thymocytes and its relation to caspase-3/caspase-6

The effects of dehydroepiandrosterone sulfate (DHEAS) on thymocyte apoptosis induced by dexamethasone (DEX) were investigated. Apoptosis was measured by using agarose gel electrophoresis of DNA, the terminal deoxynucleotidyltransferase (TdT)- mediated dUTP nick end labeling (TUNEL) assay and flow cytometry. Our results showed that preincubation with 1×10⁻⁴ M DHEAS protected thymocytes from DEX-induced apoptosis in vitro. Moreover, we found no blocking effect on the DEX-induced activation of caspase-3 and caspase-6 by the preincubation of thymocytes with DHEAS. This may be interpreted to mean that the antagonism of DHEAS to DEX-induced apoptosis is not related to the activation of these downstream caspases which play a critical role in the execution of apoptosis. Received 25 June 1999; received after revision 1 September 1999; accepted 13 September 1999