莫匹罗星软膏和重组人成纤维细胞生长因子治疗大面积烧伤残余创面的疗效研究

目的　探讨应用莫匹罗星软膏和重组人成纤维细胞生长因子 (rh -bFGF)治疗大面积深度烧伤残余肉芽创面的疗效。方法　对 36例大面积烧伤患者残余创面分两组进行自身对照 :治疗组 (36例 )用莫匹罗星软膏和重组人成纤维细胞生长因子治疗 ,对照组 (32例 )用聚维酮碘软膏治疗 ,比较两组残余创面细菌清除率和创面愈合情况。结果　金黄色葡萄球菌 (包括MRSA)和表皮葡萄球菌 (包括MRSE)为残余肉芽创面感染的主要细菌 ;治疗组细菌清除率为 86 0 % ,对照组为 37 1% ,两组间差别有显著性意义 (P <0 0 5 ) ;治疗组创面平均愈合时间为 (15 7± 3 8)d,对照组为 (2 3 9± 7 4 )d,二者间差别有显著性意义 (P <0 0 1)。结论　应用莫匹罗星软膏和rh -bFGF治疗大面积深度烧伤残余肉芽创面 ,能有效地清除残余创面感染的主要细菌 (金黄色葡萄球菌和MRSA) ,加快创面愈合。     

The orientation of gene maps by recombination of flanking markers for the am locus of Neurospora crassa

Fincham (1967), Smyth (1973b) and Rambosek and Kinsey (1983) have each generated fine-structure maps of the am gene of Neurospora crassa. Each map had a consistent linear order of alleles but the assignment of an orientation with respect to other linkage group-V loci differed. Fincham found the end marked by the am ₆ allele to be at the distal end of the locus, Smyth found am ₆ to be at the proximal end while the data of Rambosek and Kinsey did not suggest an orientation. Smyth's orientation has been adopted as the standard, but not unreservedly. We have aligned the genetic and physical maps of the am gene, showing that am ₆ is at the distal end, supporting Fincham's orientation. However, we suggest that an assumption used to orient fine structure genetic maps is flawed and that the conflicting orientation between these three studies follows from the different choice of flanking markers.     

Maize mitochondrial DNA rearrangements between the normal type,the Texas male sterile cytoplasm,and a fertile revertant cms-T regenerated plant

Summary The maize mitochondrial DNA (mtDNA) from the cytoplasmic male sterile type T (cms-T) contains a 6.6 kb XhoI fragment not found in the normal type (N) or the fertile revertant (V3). Analysis of the fragment in cms-T mtDNA and homologous regions in N and V3 mtDNAs reveals that a number of events are necessary to explain the formation of the 6.6 kb XhoI fragment in T mtDNA and its subsequent loss in V3 mtDNA. This includes the formation and the loss of a 4 kb repeat and various recombinational events. It is interesting to note that a recombinational event that has occurred in the fertile revertant genome reconstitutes a sequence arrangement identical to one found in the normal genome.     

Coexistence of Unverricht-Lundborg disease and congenital deafness: Molecular resolution of a complex comorbidity

Purpose :  We report on genetic analysis of a complex condition in a Serbian family of four siblings, wherein two had progressive myoclonic epilepsy (PME) and congenital deafness (CD), one had isolated congenital deafness (ICD), and one was healthy.
Methods and Results :  Molecular diagnosis performed by Southern blotting confirmed Unverricht-Lundborg disease in the available sibling with PME/CD. In the sibling with ICD (heterozygote for expansion mutation in CSTB ) we demonstrated recombination event between the D21S2040 marker and the CSTB gene and identified c.207delC (p.T70Xfs) mutation in the fourth exon of the transmembrane protease, serine-3 (TMPRSS3) gene (maps in close proximity to CSTB), responsible for nonsyndromic deafness in the sibling with PME/CD as well.
Discussion :  To the best of our knowledge this is the first genetic confirmation of the coexistence of these two mutations.     

中国东北部延边地区丙型肝炎病毒1a型感染研究

目的初步探讨东北部延边地区HCV基因型分布和1a型的感染状况。方法对44例来自延边地区的HCVRNA阳性样本进行HCV5’非编码区（5’NCR）复合酶切分型分析。将分型结果为1a型的4例样品（分别为Y2、Y4、Y6、Y8）进行5’NCR和NS5B区的扩增,测序,然后与27个HCV全基因参考序列（均来自GenBank）比对并构建遗传进化树。结果44例样品中1a／1b混合型19例（43．1％）,1b型12例（27．3％）,2a／1b混合型8例（18．2％）,1a型4例（9．1％）,2a型1例（2．3％）,2b型以及3～6型未检出。其中,1a型的4例样品Y2、Y4、Y6、Y8分别与各基因型的全基因参考序列相比较,在5’NCR与1a型参考序列HC—J1的同源性最高,分别为0．990、0．990、0．990、0．990,进化树分析也证实为1a型;在NS5B区与1b型参考序列HC—J4的同源性最高,分别为0．936、0．957、0．936、0．936,进化树分析表明为1b型。结论延边地区以1a／1b型混合感染为主,1b型和1b／2a型感染次之,与中国其他地区存在明显差异。对4例1a型HCV病毒株的分析发现,存在HCV5’NCR与NS5B分型结果不一致现象。分析推测可能是HCV基因组在生物进化过程中自然重组的表现,但尚需进一步研究证实。     

Vaccine derived bi- and multi-recombinant Sabin strains

A retrospective analysis of five Sabin intertypic recombinant strains, isolated from human feacal specimens during the time period 1978–1985 in Greece, was performed by RT-PCR, Restriction Fragment Length Polymorphism (R.F.L.P.) and sequencing. Of the studied strains, three (EPA, EPB, EPC) were found to be bi-recombinant Sabin3/Sabin2/Sabin3 (S3/S2/S3), one strain was characterized as a probable S3/S2- CAV18 or CAV21-S2/S1 multi-recombinant (EDP11) and one was identified as a tripartite one S3/S2/S1 (EDP12). Samples EPA, EPB and EPC presented a common recombination junction in the 2C genomic region. Moreover, strains EPA and EPB shared also the second recombination site in the 3D genomic region, whereas the second recombination of EPC was also determined in 3D but in a different nucleotide position. Strains EDP11 and EDP12 presented both identical recombination motifs and recombination sites. The first was detected in the 2C genomic region and the second in the 3D region. Strain EDP11 presented an interesting feature since a sequence of 120 nucleotides seems to have derived from a member of human enteroviruses species C (CAV18 or CAV21). This finding is of great importance, considering that this strain (EDP11) was isolated from an area and time period, where no Coxsackie A virus or poliovirus epidemics occurred. Our study underlines the role of specific positions and motifs of the poliovirus genomic sequences involved in recombination events and prompts that Coxsackie A viruses belonging to human enterovirus species C (genetically closely related to PV) are considered as the possible counterparts of the recombination.     

Molecular features of new Peach Latent Mosaic Viroid variants suggest that recombination may have contributed to the evolution of this infectious RNA

Nucleotide sequences of a broad range of Peach Latent Mosaic Viroid (PLMVd) variants were determined. The variants were isolated from peach, pear, and almond tree samples collected in Tunisia. Sequence analysis confirmed the high variability of PLMVd, as no less than 119 new variants were identified. Variations included new polymorphic positions, insertions of 11 to 14 nucleotides, and new mutations within the hammerhead self-cleavage motifs. We provide the first covariation-based evidence for certain stems within the proposed secondary structure. Our covariation analysis also strengthens the view that a pseudoknot closes the replication domain. On the basis of phylogenetic tree studies and informative positions, PLMVd variants are proposed to cluster into groups and subgroups likely to have resulted from recombination events. PLMVd thus emerges as a suitable viroid for retracing the evolution of an RNA genome.     

The repetitive portion of the Xenopus IgH Mu switch region mediates orientation-dependent class switch recombination

Vertebrates developed immunoglobulin heavy chain (IgH) class switch recombination (CSR) to express different IgH constant regions. Most double-strand breaks for Ig CSR occur within the repetitive portion of the switch regions located upstream of each set of constant domain exons for the Igγ, Igα or Igϵ heavy chain. Unlike mammalian switch regions, Xenopus switch regions do not have a high G-density on the non-template DNA strand. In previous studies, when Xenopus Sμ DNA was moved to the genome of mice, it is able to support substantial CSR when it is used to replace the murine Sγ1 region. Here, we tested both the 2 kb repetitive portion and the 4.6 kb full-length portions of the Xenopus Sμ in both their natural (forward) orientation relative to the constant domain exons, as well as the opposite (reverse) orientation. Consistent with previous work, we find that the 4.6 kb full-length Sμ mediates similar levels of CSR in both the forward and reverse orientations. Whereas, the forward orientation of the 2 kb portion can restore the majority of the CSR level of the 4.6 kb full-length Sμ, the reverse orientation poorly supports R-looping and no CSR. The forward orientation of the 2 kb repetitive portion has more GG dinucleotides on the non-template strand than the reverse orientation. The correlation of R-loop formation with CSR efficiency, as demonstrated in the 2 kb repetitive fragment of the Xenopus switch region, confirms a role played by R-looping in CSR that appears to be conserved through evolution.