Ingestions- und NBT-Reduktionskapazität neutrophiler Granulocyten bei Trisomie 21

Zusammenfassung Mit Hilfe eines modifizierten NBT-Testes wurden neutrophile Granulocyten von 30 Patienten mit Trisomie 21 im Alter von 3 Monaten bis 21 Jahren untersucht. Sowohl die Ingestions- wie auch die NBT-Reduktionskapazität der neutrophilen Granulocyten zeigten eine altersabhängige Verminderung. Es wird angenommen, daß beide Störungen die Gefährdung der Trisomie 21-Patienten durch Infektionen mitbedingen.     

地塞米松促进卵巢癌细胞系p21/WAF1和TβR-II的表达

探讨人工合成糖皮质激素地塞米松 (Dex)抑制人卵巢癌细胞系HO 8910增殖的分子机理。采用RT PCR测定细胞周期蛋白依赖性激酶抑制剂p2 1 WAF1,转化生长因子 β1 (TGF β1 )及其I型受体 (TβR I)和II型受体 (TβR II)的mRNA表达水平 ,免疫细胞化学方法分析TβR II的蛋白表达水平。发现Dex能够诱导HO 8910细胞p2 1 WAF1mR NA的表达 ,10 - 7mol LDex处理细胞 8h组比对照组p2 1 WAF1mRNA表达增加 2 84倍 (P <0 0 1)。并且证明Dex亦可上调TβR IImRNA的表达水平 ,10 - 7mol LDex处理 8h使TβR IImRNA的表达量比对照升高 1 2倍 (P <0 0 1) ;Dex也引起TβR II蛋白表达的增加。这些效应均可被糖皮质激素受体 (GR)拮抗剂RU4 86逆转。而TGF β1 和TβR ImRNA的表达不受Dex的影响。以上结果提示 ,Dex通过GR介导而促进p2 1 WAF1和TβR II的表达 ,可能参与其抑制人卵巢癌细胞HO 8910增殖过程     

The CR2/CD19 complex on human B cells contains the src-family kinase Lyn

The complement receptor 2 (CR2 or CD21) can be found in non-covalentassociation with the Blymphocyte specific CD19 complex at thesurface of mature human B cells. Upon ligation of the B cellantigen receptor complex (BCR), members of the CR2-CD19 complexmay associate with membrane immunoglobulin (mlg). Moreover,CD19 and CD21 ligands, either murine mAb, C3d fragments or Epstein—Barrvirus, are known to have profound effects on B cell activation.We here show that CD19 is tightly linked to the non-receptorsrc kinase Lyn and that the CD19 glycoprotein itself servesas a substrate for a yet undefined serine/threonine kinase presentwithin the complex. In the process of antigen recognition, mlgand the CR2-CD19 complex may bind different sites of a complement-opsonizedantigenic particle. We hypothesize that in this process, approximationto the BCR allows CD19-associated Lyn kinase to phosphorylatepotential substrates within the antigen—receptor complex,thereby effecting its coupling to the intracellular compartment.     

FISH characterization of a supernumerary r(1)(::cen→q22::q22→sq21::) chromosome associated with multiple anomalies and bilateral cataracts

We describe the case of a 15‐year‐old girl with multiple congenital anomalies, dysmorphic features, severe kyphoscoliosis, growth and mental retardation, and the absence of speech, in whom 35% of the cells carried a supernumerary ring chromosome 1. Fluorescence in situ hybridization (FISH) analysis using YAC/BAC clones spanning the region from 1p13 to 1q21 made it possible to determine the genomic content and structure of the ring(1), which was found to consist of the cytogenetic bands 1q21–22. A complex structure was delineated in the ring chromosome with a partial inverted duplication delimited by markers WI‐7732 and WI‐607, with WI‐7396 and WI‐8386 being the boundaries of the single copy segment. Comparison of the clinical signs of other patients with mosaic r(1) reported in the literature allowed the identification of a patient sharing a number of clinical signs including cataracts. Given that mutations of the GJA8 gene encoding connexin 50 (Cx50) and mapping to 1q21 have been associated with the presence of cataracts, it is possible that a gain in copy number or a rearrangement of GJA8 may contribute to cataractogenesis.     

Differential expression of cdk inhibitors p16, p21cip1, p27kip1, and cyclin E in cervical cytological smears prepared by the ThinPrep method

Our objective was to correlate p16, p21cip1, p27kip1, and cyclin E protein expression with the degree of dysplasia on ThinPrep Papanicolaou (Pap) smears using a modified immunoperoxidase staining. Smears read as normal, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion (LSIL), or high-grade SIL (HSIL) were identified and tested for high-risk human papillomavirus (HR-HPV). Additional smears were processed for immunoperoxidase for p16, p21cip1, p27kip1, and cyclin E. Thirty-four smears were satisfactory for study. The p16 was positive in all nine HSIL, in four of nine LSIL, and in one of seven ASC-US. The p27kip1 was positive in all nine HSIL, in eight of nine LSIL, and in one of seven ASC-US. The p21cip1 was positive in all nine HSIL, in one of nine LSIL, and in one of seven ASC-US. Cyclin E was positive in seven of nine HSIL and in one of nine LSIL and in none of the ASC-US smears. Normal smears were negative for all the antigens. There was poor correlation of protein expression and HR-HPV infection. We concluded that p16, p21cip1, p27kip1, and cyclin E can be demonstrated on Pap smears and they are expressed differentially in dysplastic cells, with highest expression in HSIL. The p21cip1 and cyclin E showed the greatest correlation with HSIL.     

HIV-1感染引起组蛋白乙酰化和增加p21WAF1表达

目的：DNA甲基化和组蛋白乙酰化是基因表达调控的主要形式。人类免疫缺陷病毒（HIV-1）可引起T淋巴细胞DNA甲基化酶上调。本文旨在明确HIV-1对细胞周期依赖刺激酶抑制剂p21^WAF1表达的影响。方法：建立HIV-1感染的Hut78细胞系；以RT-PCR和Westem blotting 分析p21^WAF1表达情况；以亚硫酸氢钠修饰DNA和基因测序，研究p21^WAF1基因启动子甲基化，以Western blot-ting 和染色体免疫测定探究总组蛋白和与p21^WAF1基因启动子相关的组蛋白乙酰化水平。并以GST pull-down和免疫沉淀分析HIV-1导致乙酰化及乙酰化引起p21^WAF1过表达的可能机理。结果：HIV-1感染后，其反式激活蛋白Tat与辅助转录因子P/CAF、hGCN5结合，共同刺激组蛋白H3乙酰化。尽管p21^WAF1启动子部分区域有甲基化发生，但p21^WAF1表达仍上调。这可能与E2A对p21^WAF1的作用有关。结论：HIV-1感染可引起T淋巴细胞p21^WAF1基因的甲基化和乙酰化紊乱，导致p21^WAF1表达增强。     

双基因共表达在血管再狭窄研究中的应用

目的 观察携带反义凝血酶受体(ATR)和p21的双基因载体共表达后对血管平滑肌细胞增殖的抑制作用，为再狭窄基因治疗寻求新途径。方法 以携带ATR或/和p21的单、双基因载体重组腺病毒伴随病毒(rAAV)感染培养的人主动脉平滑肌细胞(hASMC)，用半定量RT-PCR检测各基因的整合与表达，MTT法测定病毒感染后不同时间点的细胞存活率。将携带AP双基因的rAAV导入WKY大鼠拉伤侧的颈总动脉，免疫组织化学法分别检测凝血酶受体(TR)和p21两基因在动脉壁中的表达。结果 RT-PCR结果显示，TR单基因的mRNA表达降低，p2l单基因表达升高，AP双基因得到了共表达；MTT法测定的生长曲线显示，双基因对hASMC增殖的抑制作用大于两个单基因；免疫组织化学证实，AP双基因导入后，TR基因的表达受到完全抑制，p2l基因的表达明显增加，血管新生内膜与平滑肌细胞的增殖受到了抑制。结论 ATR和p21双基因共表达在体外可明显抑制ASMC的增殖，在体内可明显抑制血管内膜新生和中膜的增生。     

p53 expression in CMV-infected cells: association with the alternative expression of the p53 transactivated genes p21/WAF1 and MDM2

The p53 tumour suppressor gene is a cell cycle regulator, able to induce cell cycle arrest to allow DNA repair or apoptosis. The molecular mechanisms underlying p53 action imply transactivation of p53 dependent genes such as WAF1 (for wild type p53 associated fragment 1) and the murine double minute (MDM2) gene. In some cases, inactivation of the p53 gene results from p53 gene mutations leading to p53 protein accumulation, but in others it may results from mechanisms other than mutation, such as interaction with viral or cellular proteins. The expression of p53 protein and p53 transactivated gene proteins p21/WAF1 and MDM2, combined with in situ detection of apoptosis, was studied in specimens of CMV-infected patients as an in vivo model of p53 alteration not due to point mutation. p53 positivity was found in CMV + cells in different tissues, in cells with typical inclusion bodies, and in in situ hybridization and immunohistochemistry CMV + cells without inclusions (hidden infection). Although this p53 reactivity was accompanied by the expression of MDM2 and p21/WAF1 proteins, the patterns of MDM2 and p21/WAF1 protein expression were mutually exclusive, and were associated with the presence or absence of inclusion bodies. Nuclei bearing inclusion bodies were usually MDM2 +, p21/WAF1?, while hidden infected cells were usually MDM2?, p21/WAF1 +. Apoptosis was not detected in any tissue section from CMV-infected patients. Two alternative patterns were found in CMV-infected tissues: p53 +, p21/WAF1 +, MDM2?, or p53 +, p21/WAF1?, MDM2 + protein expression. These may represent examples of p53 dependent alternative effects in the course of CMV infection. Early stages are represented by CMV + cells without inclusion bodies, which display p53 and p21/WAF1 expression, suggesting that p53 could be acting as a growth suppressor protein. Late CMV infection is represented by cells harbouring inclusion bodies. These cells showed a p53 +, p21/WAF1?, MDM2 + profile, consistent with MDM2 mediated p53 inactivation. The absence of p21/WAF1 expression and lack of apoptosis suggest that the p53 protein expressed by MDM2 + cells could be functionally inactivated in CMV-infected cells with inclusion bodies. Previous studies have suggested that p53 inactivation by MDM2 over-expression occurs in sarcomas and lymphomas. Our observations seem to indicate that this mechanism of MDM2 mediated p53 inactivation may play a role in the late phase of CMV infection.     

Further characterization of 19 cases of rea(21q21q) and delineation as isochromosomes or robertsonian translocations in down syndrome

We have used 9 conventional RFLPs and 6 dinucleotide repeat polymorphisms on chromosome 21q to demonstrate that 17 of 19 cases of rea(21q21q) were consistent with isochromosomes i(21q) with the remaining 2 being true Robertsonian translocations. Eight of the 17 isochromosomes were of maternal origin and 9 cases were paternally derived. The 2 Robertsonian translocations were both maternally derived. Of the 17 isochromosomes, 7 were dicentric Wc(21q)I and 10 were monocentric M21q)l. Both rob(21q21q) were monocentric. Our findings agree with those made in 17 previously published cases of rea(21q21q). The parental origins of the i(21q) were equally divided between maternal (n = 17) and paternal (n = 15) origins. All 4 true rob(21q21q) reported to date are of maternal origin. Collectively, it appears that most homologous rearrangements of chromosome 21 are isochromosomes and only a small proportion are consistent with true Robertsonian translocations. © 1993 Wiley-Liss, Inc.