Mitochondrial DNA polymorphisms in Yunnan nationalities in China

Nucleotide sequences of the D-loop region of human mitochondrial DNA from four Yunnan nationalities, Dai, Wa, Lahu, and Tibetan, were analyzed. Based on a comparison of 563-bp sequences in 99 people, 66 different sequence types were observed. Of these, 64 were unique to their respective populations, whereas only 2 types were shared between the Lahu and Wa nationalities. The D-loop sequence variation and phylogenetic analysis suggested that the 99 mtDNA lineages were classified into eight clusters in the phylogenetic tree. All lineages that had a 9-bp deletion in the COII/tRNA^Lys intergenic region appeared in one cluster in the D-loop tree, suggesting a single event of the deletion in the Yunnan nationalities studied. Genetic distances, based on net nucleotide diversities between populations including Han Chinese and mainland Japanese, revealed that the Dai, Wa, Lahu, and Han Chinese are closely related to each other, while Tibetan and mainland Japanese formed a single cluster. The bootstrap probabil-ity of separation between the Dai-Wa-Lahu-Chinese clade and the Tibetan-Japanese clade was 99%, indicating that there are at least two different origins among minority groups in Yunnan province. Although the genetic distance between Tibetan and Japanese within the clade is rather long, the results may shed light on the origins of mainland Japanese. Received: December 22, 2000 / Accepted: January 18, 2001     

Kupffer cell-mediated cytotoxicity against hepatoma cells occurs through production of nitric oxide and adhesion via ICAM-1/CD18

Rat Kupffer cell (KC)-mediated cytotoxicity against both thesyngeneic hepatoma cell line AH70 and hepatocytes was evaluatedby changes in mitochondrial function, and the possible roleof ICAM-1/CD18 in the interaction between the cells was studied.Rhodamine 123 fluorescence, a marker of the mitochondrial membranepotential, decreased in AH70 cells after co-culture with KC,while that in hepatocytes was unchanged by co-culture. Thisdecrease was blocked by anti-ICAM-1, anti-CD18 and the Inhibitionof nitric oxide synthesis. Cytometric studies demonstrated thatICAM-1 expression on AH70 cells increased after addition ofIFN-, IL-1ß, tumor necrosis factor (TNF)- or KC, whilein hepatocytes ICAM-1 was not increased. Anti-ICAM-1 pretreatmentinhibited the increase in ICAM-1 expression and the decreasein rhodamine 123 fluorescence on AH70 cells after co-culturewith KC. CD18 on KC was increased only after co-culture withAH70. TNF- but not IFN- was detected in the supernatant of co-culturebetween KC and AH70 cells, and this production was partiallyinhibited by anti-ICAM-1 and anti-CD18. The activity of Induciblenitric oxide synthase in Kupffer cells and the levels of nitritesand nitrates in the co-culture supernatant increased over time,and this increase was attenuated either by addition of NO synthesisinhibitors, anti-ICAM-1 or anti-CD18. These results indicatethat the rat KC causes mitochondrial dysfunction in cancer cellsvia the production of NO and cell-to-cell adhesion via ICAM-1/CD18has an Important role in this cytotoxic process.     

大鼠孤束核内NT-LI成分生后发育和衰老变化的光镜和电镜观察

用免疫细胞化学和电镜相结合技术,在光镜和电镜水平对生后4天、15天、30天、90天、300天和760天6组大鼠孤束核内神经降压肽样免疫反应(NT-LI)成分的生后发育和衰老变化进行了定量研究。光镜下孤束核内NT-LI胞体和终末主要分布于最后区平面,多见于背侧亚核、内侧亚核和连合核内。电镜下内侧亚核内可见NT-LI胞体、树突、轴突及终末。6组大鼠孤束核内NT-LI细胞均数和内侧亚核内NT-LI终末密度及其突触密度均以生后4天至15天间增长最快,NT-LI细胞数在生后15天达到最高,NT-LI终末及突触密度在生后90天达到最高。三者在生后300天时均明显减少。发育期内侧亚核内NT-LI终末构成的突触以Gray Ⅰ型为主,至老年期则变为Gray Ⅱ型占优势。发育期内侧亚核内以含清亮囊泡伴颗粒囊泡的NT-LI终末为主,老年期此类终末明显减少。只含清亮囊泡的NT-LI终末从生后至老年变化不明显。     

DICOM数据的三维重建与协同可视化系统的开发

复杂手术常需多科医生协商制定综合性治疗方案,网络协同三维可视化软件可使方案制定直观而精确。我们采用VTK工具包对DICOM格式CT图像数据进行三维重建并作网格简化,将结果所得多边形网格模型无缝集成到用HOOPS/3DAF所开发的图形系统进行显示,并用HOOPS/Stream工具包转成适合网络传输的HSF无损压缩流文件,再用HOOPS/NET工具包实现基于Client/Server架构的协同三维交互可视化系统。所得三维重建结果清晰,协同三维可视化操作实时度高。本研究实现了一个协同手术仿真开发平台,该架构易于进一步添加模拟手术操作与修复体设计功能。     

No allelic association between Parkinson's disease and dopamine D2, D3, and D4 receptor gene polymorphisms

Parkinson's disease is thought to be caused by a combination of unknown environmental, genetic, and degenerative factors. Evidence from necropsy brain samples and pharmacokinetics suggests involvement of dopamine receptors in the pathogenesis or pathophysiology of Parkinson's disease. Genetic association studies between Parkinson's disease and dopamine D2, D3 and D4 receptor gene polymorphisms were conducted. The polymorphism was examined in 71 patients with Parkinson's disease and 90 controls. There were no significant differences between two groups in allele frequencies at the D2, D3, and D4 dopamine receptor loci. Our findings do not support the hypothesis that susceptibility to Parkinson's disease is associated with the dopamine receptor polymorphisms examined. © 1994 Wiley-Liss, Inc.     

Approaches to functional genomics: potential of matrix-assisted laser desorption ionization--time of flight mass spectrometry combined with separation methods for the analysis of DNA in biological samples

MALDI-TOF MS has potential as a valuable technique in DNA mapping studies and may well be complementary to other approaches to DNA analysis such as gel electrophoresis and sequencing. This study used 2,6-dihydroxyacetophenone (DHAP) mixed with diammonium hydrogen citrate (DAHC) as the matrix. In addition, recent technical advances such as time lag focussing (TLF) and better selection of matrices (such as 3-hydroxypicolinic acid (3 HPA) and picolinic acid (PA)) extended the range of DNA fragments that can be studied by this approach. The following samples were investigated: Poly-T mixture (dT 15, 19, 20, 25, 74 and 75), plasmid pBR322 derived oligonucleotides (10, 11, 12, 13, 14, 15, 19, 20 and 50 nucleotides long) and DNA fragments of 25, 36 and 37 base pairs corresponding to a fragment in the restriction map for the gene corresponding to the hexon protein of Adenovirus 2 and 5. The results were contrasted with similar analyses performed by ion-paired reversed-phase HPLC coupled to on-line electrospray mass spectrometry.     

Bone-particle-impregnated bone cement: an in vivo weight-bearing study

To evaluate an experimental inorganic-bone-particle-impregnated bone cement, canine hip prostheses were implanted in dogs using a regular bone cement on one side and the experimental bone cement on the other. In a preliminary feasibility study, bone ingrowth into the resorbed bone-particle spaces was established 3 months after implantation in three dogs. In a more detailed study, twenty-eight (28) dogs were divided in four groups to delineate the effects of time on the phenomena of bony ingrowth. One month after implantation, active bone ingrowth into the bone cement was obvious. By 3 months postimplantation, the ingrowth appeared to have traversed the thickness of the bone-particle-impregnated cement. By the fifth month, most of the interconnected inorganic bone particles were replaced by new bone. At the end of a year, the ingrown bone was mature and negligible new bone activity was present. Biomechanical pushout tests closely corroborated the histologic observations. The maximum shear strength of the cement/bone interface of the experimental side reached 3.6 times that of the control side at 5 months postimplantation. No further improvements were seen at 12 months postimplantation. A viable bone/cement interface may result in a better orthopedic implant fixation system by combining the advantages of both cement for immediate rigidity and biological ingrowth for longterm stability.