Structural and mutational analysis of a conserved gene (DGSI) from the minimal DiGeorge syndrome critical region

The majority of patients with DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome (CTAFS) and some individuals with familial or sporadic conotruncal cardiac defects have hemizygous deletions of chromosome 22. Most patients with these disorders share a common large deletion, spanning > 1.5 Mb within 22q11.21-q11.23. Recently, the smallest region of deletion overlap has been narrowed to a 250 kb area, the minimal DGS critical region (MDGCR), which includes the locus D22S75 (N25). We have isolated and characterized a novel, highly conserved gene, DGSI, within the MDGCR. DGSI has 10 exons and nine introns encompassing 1702 bp of cDNA sequence and 11 kb of genomic DNA. The encoded protein has 476 amino acids with a predicted mol. wt of 52.6 kDa. The intron-exon boundaries have been analyzed and conform to the consensus GT/AG motif. The corresponding murine Dgsi has been isolated and localized to proximal mouse chromosome 16. The mouse gene contains the same number of exons and introns, and the predicted protein has 479 amino acids with 93.2% identity to that of the human DGSI gene. By database searching, both genes have significant homology to a Caenorhabditis elegans hypothetical protein, F42H10.7. Further, mutation analysis has been performed in 16 patients, who have no detectable 22q11.2 deletion and some of the characteristic clinical features of DGS/VCFS. We have detected eight sequence variants in DGSI. These occurred in the 5'- untranslated region, the coding region and the intronic regions adjacent to the intron-exon boundaries of the gene. Seven of the eight variants were also present in normal controls or unaffected family members, suggesting they may not be of etiologic significance.      

Functional correction of short-chain acyl-CoA dehydrogenase deficiency in transgenic mice: implications for gene therapy of human mitochondrial enzyme deficiencies

We report the therapeutic effects of liver-specific expression of a short-chain acyl-CoA dehydrogenase (SCAD) transgene in the SCAD- deficient mouse model. Transgenic mice were produced with a rat albumin promoter/enhancer driving a mouse SCAD minigene (ALB-SCAD) on both the SCAD normal genetic background and a SCAD-deficient background. In three transgenic lines produced on the SCAD-deficient background, recombinant SCAD activity and antigen in liver mitochondria were found up to 7-fold of normal control values. All three lines showed a markedly reduced organic aciduria and fatty liver, which are sensitive indicators of the metabolic abnormality seen in this disease found in children. We found no detrimental effects of high liver SCAD expression in transgenic mice on either background. These studies provide important basic and practical therapeutic information for the potential gene therapy of nuclear-encoded mitochondrial enzyme deficiencies, as well as insights into the mechanisms of the disease.      

Clostridium difficile-Associated diarrhoea in uremic patients

An outbreak of 94 episodes of Clostridium difficile-associated diarrhoea in 62 patients in a nephrology ward over a two-year period was investigated. Quantitative stool cultures were performed on ten uremic patients not on antibiotics and without diarrhoea and on ten healthy controls. All diarrhoeal episodes were associated with Clostridium difficile,and no other bacterial pathogens were isolated. Thirty-two relapses occurred in 16 patients, fourteen of the relapses without preceding antibiotic exposure.Clostridium difficile could not be isolated from the environment of the patients. Uremic patients, who had a significantly increased number of Clostridium spp. in their stools, are predisposed to Clostridium difficile infections.     

Genetics of multiple sclerosis [published erratum appears in Hum Mol Genet 1997 Nov;6(12):2189]

Multiple Sclerosis (MS) is a common chronic central nervous system disease in young adults. Relative familial risk appears to be determined largely by genes while population risk is strongly influenced by environmental factors. This is supported by genetic epidemiological studies which also suggest an oligogenic inheritance of susceptibility. The HLA DRB1*1501, DQA1*0102, DQB1 0602 haplotype is associated with the disease but HLA contributes only modestly to overall susceptibility. The results of three genomic searches are concordant with the genetic epidemiology and imply a number of genes with interacting effects will be found. Importantly, no single region has been identified with a major influence on familial risk.      

丙氧鸟苷对转TK基因的人外周血单个核细胞的毒性作用

目的 探讨减少异体干细胞移植中移植抗宿主病（GVHD）,同时最大限度提高移植抗白血病（GVL）效应的有效方法。方法 采用逆转录病毒介导的基因转移方法将I型单纯疱疹病毒胸苷激酶（HSV－TK）基因、绿色荧光蛋白（GFP）基因及抗新霉素（NeoR）基因插入人外周血单个核细胞（PBMC）,MTT法测定丙氧鸟苷（GCV）对转化细胞抑制率。结果 转化细胞表达GFP,且主要为T淋巴细胞,占11．4％,而且被转化的T淋巴细胞中,CD4阳性细胞转化率较高,占7．6％,CD8,CD19,CD33阳性细胞转化率分别为2．9％,2．1％和4．7％,PCR鉴定表明,转染的人外周血单个核细胞DNA中整合中有NeoR基因,MTT法测定丙氧鸟苷（GCV）对转化细胞与未转化细胞抑制率,显示转化细胞生长明显受抑。结论 异体干细胞移植后,如产生严重GVHD应用GCV选择性清除HSV－TK基因转导的T淋巴细胞,使控制GVHD已成可能。     

Effect of Transforming Growth Factor-β_2 on Phagocytosis in Cultured Bovine Trabecular Meshwork Cells

A gradual loss of cells occurs within the humantrabecular meshwork (TM) during normal aging andappears to be increased in patients with primary openangle glaucoma (POAG) [1] .The exactmechanism bywhich cells are lost in either condition is not known,however phagocytosis has been suggested[2 ] .It hasbeen found that,when compared with the non- POAGpatients,the level of transforming growth factor- β2(TGF- β2 ) which may be involved in the pathogenesisof POAG increased in the aqueous humo…