Analysis of human T-lymphotrophic virus sequences in multiple sclerosis tissue

Several observations suggest that retroviral infection is involved in the pathogenesis of the human demyelinating disease multiple sclerosis (MS). First, lymphadenopathy-associated virus/human T-lymphotropic virus type III (LAV/HTLV-III), the agent of acquired immune deficiency syndrome (AIDS), has been shown to be neurotropic in man. Second, the genetic organization of the lentivirus visna, which causes a chronic demyelinating disease of sheep, closely resembles that of LAV/HTLV-III. Recently, Koprowski and colleagues reported that MS is associated both with raised levels of circulating antibodies to HTLV-I and with the presence of HTLV-I-specific RNA within cell lines derived from the cerebrospinal fluid (CSF). Here we report that no HTLV-I-like or LAV/HTLV-III-like sequences can be detected, by in situ hybridization, in central nervous system (CNS) tissues from MS patients, and that nonspecific HTLV-I-like signal in peripheral blood mononuclear cells or in CSF cell lines is characteristic of MS. Furthermore, enzyme-linked immunosorbent assay (ELISA) analysis of circulating and CSF antibodies for HTLV-I reactivity fails to distinguish between MS and control groups.     

Developmental regulation of human fetal-to-adult globin gene switching in transgenic mice

Transgenic mice containing a human fetal (gamma-) or adult (beta-) globin gene linked to the beta-globin gene locus activation region (LAR) express the gene throughout development. By contrast, transgenic mice containing LAR linked to both a fetal and an adult globin gene display the normal developmental switch from fetal to adult gene expression. This suggests that the human fetal-to-adult globin gene switch is controlled through a mutually exclusive interaction between LAR and either the gamma- or beta-globin gene, resulting in the expression of only one gene at any given moment.     

用近红外光谱检测人体组织氧含量

为防止病人因组织缺氧而产生各种临床并发症 ,需要检测病人的组织氧。红外组织氧含量检测技术是一种新的无损检测技术 ,相对于脉搏氧饱和度检测 ,可以检测局部人体组织的氧合状况。用自行设计的近红外组织氧含量检测仪 ,进行了前臂阻断实验、婴儿脑氧实验和肌氧实验。检测中考虑了近红外传感器与人体的耦合 ,合理选择了光源与检测器的距离以及检测器的数目。用该仪器测量结果与生理变化相符。结果表明 :近红外方法可以实时无损地检测人体组织的氧合状况     

Synchrotron refractive-index microradiography of human liver cancer tissue

Three human liver tissue samples （-5 mm × 40 mm × 20 mm） were excised from a cancer patient＇s liver during surgery. The microradiology analysis was performed with a non-standard approach on a synchrotron. High-resolution refractive-index edge-enhanced microradiographs that cover a larger volume of the liver tissue sample were obtained. The cancer tissue and normal tissue could be clearly identified and distinguished based on their different textures. Furthermore, new blood vessel hyperplasia was found near the cancer area. Blood vessels with a diameter smaller than 20 μm could be identified. These findings were fully consistent with the histopathological examination or the same area. Microradiographs of the newly formed blood vessels at different angles were also obtained. This result shows that it is possible to further develop this approach into a technique of microradiographic imaging for clinic diagnosis of liver cancer at the early stage.