远程医疗会诊车应用情况及改进建议

介绍了远程医疗会诊车的性能特点、使用方法、功能及应用范围并提出了改进建议。     

Higher-order organization and compartmentalization of satellite DNA PIM357 in species of the coleopteran genus Pimelia

The PIM357 satellite DNA family is present in 26 Pimelia taxa (Tenebrionidae, Coleoptera) with endemic congeneric species from the Canary Islands showing higher interrepeat variability than continental ones. In this paper, we compare the repetitive DNA sequences of a Canarian species that has distinct subfamilies of repeat units, P. radula ascendens, with another without such subfamilies, P. sparsa sparsa. The chromosomal localization of the repeat units and the comparison of the variability of randomly cloned monomers to the one estimated by comparing repeat units from dimers and trimers suggest the absence of satellite subfamilies in P. sparsa sparsa. Hence, the repeat units of this species seem to be uniformly and randomly distributed throughout all chromosomes out of one chromosomal pair. On the contrary, P. radula ascendens shows four divergent subfamilies of repeat units supported by several diagnostic nucleotide substitutions. These subfamilies seem to form four distinct repeat units: monomer subfamily 1, monomer subfamily 4 and two higher-order units (dimer linking subfamily 1 and 4, and dimer linking subfamily 2 and 3). Moreover, monomers of subfamily 1 are present in three chromosomal pairs only. We discuss the effect of different potential factors acting in the concerted evolution and the genomic organization of stDNA sequences in these taxa. This revised version was published online in July 2006 with corrections to the Cover Date.     

细胞移植治疗心肌梗死的研究与展望

细胞移植是治疗心肌梗死的一种新策略,本文对目前应用于临床研究的骨骼肌卫星细胞移植及骨髓干细胞移植治疗心肌梗死的进展进行综述。上述两种细胞移植均具有来源丰富、无排斥反应的特点,而且通过研究观察表明,上述两种细胞移植后,心脏功能均能得到改善,故具有美好发展前景。但二者亦均具有不足之处和需要解决的问题,还需进一步研究与探索。     

离心作用测定细胞与材料间的粘附力及其初步应用

目的：介绍一种简单易行的检测细胞与材料间黏附力的方法。方法：本方法的建立基于离心力在转速一定时与半径成正比的原理。医用石膏制备培养皿固定装置，于培养皿底制备材料薄膜（包括有PLGA，PLGA COLI，PLGA COL I FN），待大鼠骨骼肌卫星细胞悬液与其作用一定时间后，一定转速开动离心机。测定未脱落细胞斑的半径R,取均值。结果：上述三种材料表面未脱落大鼠骨骼肌卫星细胞圆斑半径（R）分别为7.96、15.11、26.10mm，三组间有显著性差异。结论：（1）R的变化可反映细胞与材料间粘附力的改变。（2）利用离心作用检测细胞与材料间的粘附力是可行的，尤其适用于同一种细胞与不同材料间粘附力的比较。（3）COL I和FN的使用可以增加大鼠骨骼肌卫星细胞与PLGA间的粘附。     

5-Azacytidine produces differential undercondensation of alpha,beta and classical human satellite DNAs

Fluorescencein situ hybridization employing human alphoid, beta and classical satellite DNA probes was performed on 5-azacytidine treated and untreated chromosomes obtained from human lymphocytes. The individual used in this study presented a polymorphism of constitutive heterochromatin of chromosomes 1 and 9 as revealed byin situ digestion with the restriction endonucleaseAlul. Neither the alphoid nor the beta satellite DNA domains were susceptible to condensation-inhibition by 5-azacytidine. Only the classical satellite localized on chromosome 9 was affected. The constitutive heterochromatin size polymorphism was shown to depend mainly on variations of the classical satellite DNA domain. Therefore, condensation-inhibition, as a phenomenon which may modify the natural folding of the chromatin fibre, regionally affects human constitutive heterochromatin and seems to be dependent on the heterochromatic family.     

Satellite cells express the trophic factor IGF-I in regenerating skeletal muscle

The expression of insulin-like growth factor I (IGF-I, somatomedin C) was studied in regenerating skeletal muscle. Irreversible damage to skeletal muscle cells was induced in the extensor digitorum longus muscle (EDL) of adult rats by ischaemia, preceded by glycogen depletion, and the regeneration process was studied for periods up to 14 days after injury. The IGF-I was demonstrated by indirect immunofluorescence. Immunoreactivity against ribonucleotide reductase (RR) was used as a marker for DNA synthesis, that is, cell proliferation. Increased IGF-I immunoreactivity could be demonstrated within 24h after injury in satellite cells, intramuscular nerves and in blood vessels. The IGF-I immunoreactivity remained virtually unchanged in the contralateral, undamaged EDL. An increasing number of satellite cells, expressing high IGF-I immunoreactivity, could be demonstrated in the injured EDL, and within 72 h myoblasts, expressing high IGF-I and RR immunoreactivity, were formed. Small immature muscle cells, displaying high IGF-I immunoreactivity, were observed 4 days after injury. Increased IGF-I immunoreactivity was still obvious in the regenerated muscle cells 14 days after injury while RR immunoreactivity was seen only in scattered satellite cells. It is concluded that IGF-I may act as a trophic factor during regeneration of skeletal muscle after injury.     

Muscle satellite (stem) cell activation during local tissue injury and repair

In post-mitotic tissues, damaged cells are not replaced by new cells and hence effective local tissue repair mechanisms are required. In skeletal muscle, which is a syncytium, additional nuclei are obtained from muscle satellite (stem) cells that multiply and then fuse with the damaged fibres. Although insulin-like growth factor-I (IGF-l) had been previously implicated, it is now clear that muscle expresses at least two splice variants of the IGF-I gene: a mechanosensitive, autocrine, growth factor (MGF) and one that is similar to the liver type (IGF-IEa). To investigate this activation mechanism, local damage was induced by stretch combined with electrical stimulation or injection of bupivacaine in the rat anterior tibialis muscle and the time course of regeneration followed morphologically. Satellite cell activation was studied by the distribution and levels of expression of M-cadherin (M-cad) and related to the expression of the two forms of IGF-I. It was found that the following local damage MGF expression preceded that of M-cad whereas IGF-IEa peaked later than M-cad. The evidence suggests therefore that an initial pulse of MGF expression following damage is what activates the satellite cells and that this is followed by the later expression of IGF-IEa to maintain protein synthesis to complete the repair.     

Recently amplified satellite DNA inCallithrix argentata (Primates,Platyrrhini)

A satellite DNA has been cloned from the neotropical primateCallithrix argentata and designated CarB. The presence of the satellite was assayed in New and Old World primates by blot hybridization: CarB is highly amplified in the genomes of all three species belonging to theC. argentata species group (C. argentata, C. emiliae, C. humeralifer), but is either absent, or present in only minor amounts, in other primates, including the closely related species,C. jacchus. A completely sequenced CarB monomeric unit was 1528 bp in length and mapped to the telomeric C-band-positive regions of manyC. argentata species group chromosomes. Sequence data from eight CarB clones indicated an average difference of 3.5% when base substitutions alone were counted. The hybridization and sequence data suggest that this satellite underwent a period of amplification and dispersal in the genome of a recent ancestor of theC. argentata species group.     

The distribution of binding sites for centromere protein B (CENP-B) is partly conserved among diverged higher order repeating units of human chromosome 6-specific alphoid DNA

We previously reported the isolation of alphoid satellite clones from a human genomic library using a DNA immunoprecipitation with centromere protein B (CENP-B). Here, we have characterized the distribution of CENP-B-binding sites on the 3-kb BamHI repeats of the cos2 clone. Using in situ hybridization, this alphoid satellite was located primarily at the centromeric region of chromosome 6. The functional binding sites were mapped by precipitating the restriction fragments with recombinant CENP-B in vitro. One repeat (2B3-11) consisted of 19 copies of alphoid monomer, eight of which possessed the binding sites, while another (2B3-9) consisted of 18 copies of the monomer, seven of which possessed the binding sites. The distribution of the sites was well conserved between them, except for the terminus. A similar analysis with the remaining 6-kb region suggested the presence of a continuous 1-kb region with regular spacing of EcoRI sites and the CENP-B-binding sites. When the nucleotide sequence of 2B3-11 was compared with that of another chromosome 6-specific alphoid repeat (p308) that had been described previously, this 1-kb region was highly conserved between them. The distribution of the CENP-B binding sites and the order of alphoid monomers might define the folding of alphoid repeats in the centromeric region.This revised version was published online in November 2005 with corrections to the Cover Date.     

河南食管癌高发区居民食管癌变过程中微卫星LOH的特征

目的微卫星（microsatellite）是广泛分布于生物基因组中的DNA重复序列，与许多重要基因紧密连锁。本研究旨在探讨食管癌变多阶段演进过程中微卫星DNA杂合缺失（loss of heterozygosity，LOH）的特征及其意义。方法采用微卫星DNA多态分析法，选取染色体3p、5q、6p、9p、13q、17p、17q和18q的15个多态微卫星位点，对32例食管癌前病变和癌组织进行LOH分析。结果食管各级癌前病变组织和癌组织均出现不同程度的微卫星DNALOH，其频率随病变程度加重而明显升高（除D9S1752位点外，P均〈0．05）；其中D9S171、D13S260和TP53位点在癌阶段，LOH频率均超过60％。各级癌前病变组织和癌组织中发生LOH的位点不尽相同，同一个体从基底细胞过度增生→间变→原位癌→鳞状细胞癌，均发生LOH的位点是：D3S1234和TP53。结论基因水平的改变发生在食管癌变的早期阶段，随病变程度加重，基因组不稳定性增强，可能是导致食管癌前病变持续向癌的方向发展的重要机制之一。