胎球蛋白—胶体金探针的制备

本文用柠檬酸钠还原法制备胶体金，以光吸收法和琼脂糖电泳法检测胎球蛋白－胶体金探针的稳定性，为胶体金探针的制备探索最佳条件。实验结果表明：ｐＨ在２～３．５时，探针稳定性较差；ｐＨ在５～１０时，需要较少量胎球蛋白即可获得稳定探针，在电场中也可稳定存在，ｐＨ在６～１０之间探针的电泳行为相似。实验表明，琼脂糖电泳有可望成为鉴定和分离胶体金探针的简易途径。     

花背蟾蜍角膜早期发育期间胎球蛋白结合位点的分布

本文用酶标胎球蛋白作为探针，在光镜水平对花背蟾蜍角膜早期发育中胎球蛋白结合位点（ＦＢＳ）进行组化定位，结果表明ＦＢＳ主要分布在角膜上皮层，胚胎发育至２０期，ＦＢＳ开始出现；在２２期和２３期，基底细胞中ＦＢＳ减少，在基膜附近大量密集；２４期ＦＢＳ在基底细胞中再度增加而均一分布在上皮层，表层细胞游离面在２５期在出现无ＦＢＳ的区带，纤毛细胞中始终无ＦＢＳ分布，而只在２５期时其游离面出现ＦＢＳ，认为ＦＢＳ     

提高抗人球蛋白试验

在确保临床输血安全和临床鉴别诊断溶血性贫血的工作中,血型血清学实验室项目抗人球蛋白试验(库姆试验)具有非常重要的意义。这项试验是检查待检者血清中和细胞上存在的不完全抗体,分直接和间接抗人球蛋白试验两种方法。直接抗人球蛋白试验是检查被检者红细胞上有无不完人抗体,临床用于检验新生儿溶血病(患儿红细胞在胎内已被母亲的抗体致敏;溶血性输血反应输入不相合的红细胞被受血者的抗体致敏);药物诱发性溶血性贫血;自身免疫性溶血性贫血(患者红细胞被自身抗体致敏)等疾病诊断依据。间接抗人球蛋白试验是用抗体筛选谱细胞检查血清中有无游离的不完全抗体,临床用于血型系统免疫抗体筛选、交叉配血等试验,但某些血型,如D~U、Duffy、Kell及Kidd等血型,也需用此法检查。 抗人球蛋白试验是将抗人球蛋白血清加     

新疆绵羊β-乳球蛋白(BLG)5′端调控区的克隆与序列测定

用聚合酶链式反应(PCR)技术,从新疆绵羊全血中扩增了β-乳球蛋白5′端调控区890bp的片段.通过T4 DNA连接酶将其连接于质粒载体pGEM-T上,转化至受体菌DH5α中.提取质粒经PCR扩增、酶切鉴定,证明重组质粒pT-BLG中含有β-乳球蛋白5′端调控区基因片段.经核苷酸序列测定,克隆的片段与发表的基因序列高度一致.     

中华大蟾蜍蝌蚪发生类坏死的皮肤在恢复过程中Con A受体的变化研究

本研究以中华大蟾蜍后肢芽期的蝌蚪为材料,以0.001/molL 氨水处理皮肤使之发生类坏死.运用荧光标记的凝集素刀豆球蛋白 A(Con A)结合半薄切片技术观察了皮肤发生类坏死后恢复过程中 Con A 受体的变化.结果发现:正常皮肤表面细胞质膜下,细胞质和基膜中有一些Con A 受体分布.经类坏死处理后,表面细胞内出现了一层团块状分布的 Con A 受体,基底细胞膨大,一类膨大的细胞中仅细胞核和质膜上有 Con A 受体分布,另一类细胞中核和质均有 Con A受体分布.类坏死处理后1h,表面细胞内团块状分布的 Con A 受体变成小颗粒排列在质膜下,表皮细胞质中 Con A 受体较多,基膜中也出现较多的 Con A 受体;类坏死处理3h 表面细胞,基底细胞和基膜中 GonA 受体的分布和1h 的相似:类坏无处理后5h,Con A 受体逐渐减少并恢复正常.结果表明,生发类坏死的皮肤在恢复过程中 Con A 受体对保持结构的完整性及正常的生理功能具有重要的意义.     

麦洼牺牲占和犏牛乳蛋白的遗传多态性

用聚丙烯酰胺凝胶电泳分析了５４头麦洼牦牛和１９头牦牛乳蛋白的遗传多态性。结果显示，牦牛和犏牛的α－乳清蛋白均呈ＢＢ型，β－乳球蛋白在犏牛中为ＡＢ型，在牦牛中型β－乳球蛋白在凝胶上梁色通常极弱。     

西藏嘉黎,亚东牦牛血清蛋白含量及组成分析

采用Ｂｒａｄｆｏｒｄ比色法测定西藏嘉黎、亚东两地区牦牛血清总蛋白含量，通过醋酸纤维薄膜电泳分离其血清蛋白各组成，并以ＣＤＳ２００型计算机控光密度仪进行扫描．测得４９头嘉黎牦牛的血清总蛋白含量为６．２８±０．３４ｇ／１００ｍｌ血清，其中各组成的百分含量分别是：白蛋白４５．５９±０．９２，α１球蛋白１７．０６±０．４０，α２球蛋白８．９７±０．６８，β球蛋白１０．５１±０．５０，γ球蛋白１７．７５±０．７０，清球蛋白比值（Ａ／Ｇ）为０．８４±０．０２；３６头亚东牦牛的血清总蛋白含量为６．４５±０．２０ｇ／１００ｍｌ血清，其中各组成的百分含量分别是：白蛋白４６．６６±１．１０，α１球蛋白１７．４８±１．０２，α２球蛋白８．８５±０．６６，β球蛋白９．６３±０．７４，γ球蛋白１７．４２±０．９８，清球蛋白比值（Ａ／Ｇ）为０．８８±０．０４．经ｔ检验分析，两地区牦牛血清蛋白组成中只有β球蛋白含量具有显著差异（Ｐ＜０．０５），其余均无显著性差异（Ｐ＞０．０５）．     

胎肝Sca-1+细胞治疗STZ诱导小鼠糖尿病的实验研究

目的探讨小鼠胎肝组织中的干细胞抗原1阳性的细胞(Sca-1+细胞)治疗链脲佐菌素(STZ)诱导糖尿病鼠的潜能.方法取14.5 d的C57BL/6J小鼠胎肝,制作细胞悬液,用单克隆免疫磁珠细胞分离技术分离Sca-1+细胞,将2×105个雄性小鼠Sca-1+细胞输注到STZ诱导的C57BL/6J雌性小鼠体内,以后每7 d定时测定小鼠血糖,第38 d处死受体小鼠取胰腺组织固定、切片,免疫组化观察胰腺组织中胰岛素阳性的β细胞变化.结果小鼠胎肝Sca 1+细胞能够有效抑制STZ诱导小鼠血糖的持续升高,明显降低糖尿病鼠的死亡率.受体小鼠胰岛细胞结构清楚,其中可见表达胰岛素的β细胞,荧光原位杂交显示小鼠胰岛内有Y染色体阳性杂交点.结论小鼠胎肝Sca-1+细胞具有一定的治疗小鼠糖尿病的作用.     

小鼠胎肝间充质干细胞体内向骨骼肌样细胞分化的研究

目的:了解小鼠胎肝间充质干细胞在体内向骨骼肌细胞分化的潜能。方法:无菌条件下将C57BL/6 J胎鼠肝脏制成单细胞悬液,雄性胎肝悬液体外贴壁培养纯化,传3代后将贴壁细胞移植于心肌毒素(card iotoxin)造成的雌鼠骨骼肌损伤部位,2月后处死受鼠,取相应骨骼肌组织固定、制片;用免疫组织化学染色和荧光原位杂交检测雌性受体小鼠骨骼肌组织内供体小鼠胎肝间充质干细胞向骨骼肌样细胞分化情况。结果:在骨骼肌组织内发现存在Y染色体阳性的供体来源的细胞,同时呈现骨骼肌组织的部分特征,表型为desm in /F lt-1-/CD4-5/F4-/80。结论:胎肝中分离出的间充质干细胞在体内可以分化为骨骼肌样细胞。     

Rh系抗E抗体所引起HDN2例

例1，患儿刘某．男，4天，出生后第2天巩膜出现黄染．并逐渐加重，第3天全身皮肤出现黄集，无抽搐。化验检查：Hb93g／L，RBC2．70×1012／L，肝功能正常。第4天到我堂做新生儿溶血病试验检查证实为m系统抗E抗体所引起的HDN。患儿血型为B，CcDce；其父亲血型为B，CcDEE型；其母亲血型为B，thDbo型．汉族，无担血史，怀孕2次，第一胎妊娠足月死股，本例患儿为第2胎．于1995年3月5日足月剖因产取股术．结束妊娠。患儿新生儿溶血病三项试验结果：直接抗火球蛋白试验阳性；游离抗体试验阳性；释放抗体试验阳性r’）。患儿释放浪和母亲…     

Receptive fields in the body-surface map in adult cortex defined by temporally correlated inputs

Receptive fields (RFs) obtained at specific cortical sites can be used to define a topographic map of the body surface in adult mammalian somatosensory cortex. This map is not static, and RFs at particular cortical sites can change in size and location throughout adult life. Conversely, the cortical loci at which a given skin surface is represented can shift hundreds of micrometres across the cortex in the koniocortical field, area 3b (refs 1-12). This plasticity suggests that RFs derive not from rigid anatomical connections, but by the selection of a subset of a large number of inputs. We have proposed that inputs are selected on the basis of temporal correlation 11-15. Here we test this idea by altering the correlation of inputs from two adjacent digits on the adult owl monkey hand by surgically connecting the skin surfaces of the two fingers (the formation of syndactyly). This manipulation increases the correlation of inputs from skin surfaces of adjacent fingers. The striking discontinuity between the zones of representation of adjacent digits on the somatosensory cortex disappeared. These results support the hypothesis that the topography of the body-surface map in the adult cortex is influenced by the temporal correlations of afferent inputs.     

The role of clonal selection and somatic mutation in autoimmunity

Polyclonal activation has been proposed as the reason that autoantibodies are produced during autoimmune disease. This model denies a role for specific antigen selection of B cells and predicts instead a multiclonal population of unmutated or randomly mutated autoantibodies. We have found that the genetic features and clonal composition of spontaneously derived immunoglobulin G (IgG) antiself-IgG (rheumatoid factor (RF] autoantibodies derived from the autoimmune MRL/lpr mouse strain are inconsistent with both the predictions of this model and the actual outcome of experimental polyclonal activation. Instead we have found that MRL/lpr RFs are oligoclonal or even monoclonal in origin. They harbour numerous somatic mutations which are distributed in a way that suggests immunoglobulin-receptor-dependent selection of these mutations. In this sense, the MRL/lpr RFs resemble antibodies elicited by exogenous antigens after secondary immunization. The parallels suggest that, like secondary immune responses, antigen stimulation is important in the generation of MRL/lpr RFs.     

几种类风湿关节炎吸附剂的制备及吸附性能比较

制备了5种不同的类风湿关节炎吸附剂.用它们与类风湿关节炎病人血清作静态吸附实验,EL ISA检测吸附前后血清中RF s的浓度变化.实验发现,以纤维素球为载体,环氧氯丙烷活化后固定苯丙氨酸为配基的吸附剂综合吸附效果最好.该吸附剂对病人血清中IgGRF,IgM RF,IgARF的吸附中分别为39.3%,56.0%,28.1%.血液相容性实验结果显示,该吸附剂的血液相容性良好,能够满足临床应用要求.本文还研究了手臂对吸附剂吸附性能的影响,静态吸附实验结果显示PEG 4000为手臂的吸附剂吸附性能要高于以1,4-丁二醇二缩水甘油醚为手臂的吸附剂.     

自体细胞来源的组织工程皮肤及其实验研究

利用患者自体来源的皮肤细胞,在经过短时间的体外培养后构建组织工程皮肤,并对其移植后的转归进行动物实验观察.分离培养头皮中的角质形成细胞及创面来源的成纤维细胞,并在体外进行传代扩增.利用三维立体培养系统构建复合细胞膜片,移植于裸鼠背部全层缺损创面,以单层细胞膜片为对照,对其转归进行大体及病理学观察.体外分离培养的皮肤细胞在体外扩增2周后即可用于构建复合细胞膜片,在移植覆盖裸鼠全层皮肤创面后,伤口愈合良好,移植2月后的病理结果显示皮肤结构明显优于单层膜片移植.证明利用患者自体来源的皮肤细胞可快速构建组织工程皮肤,有望成为治疗大面积深度烧伤患者的途径之一.     

Visualization of release factor 3 on the ribosome during termination of protein synthesis

Termination of protein synthesis by the ribosome requires two release factor (RF) classes. The class II RF3 is a GTPase that removes class I RFs (RF1 or RF2) from the ribosome after release of the nascent polypeptide. RF3 in the GDP state binds to the ribosomal class I RF complex, followed by an exchange of GDP for GTP and release of the class I RF. As GTP hydrolysis triggers release of RF3 (ref. 4), we trapped RF3 on Escherichia coli ribosomes using a nonhydrolysable GTP analogue. Here we show by cryo-electron microscopy that the complex can adopt two different conformational states. In 'state 1', RF3 is pre-bound to the ribosome, whereas in 'state 2' RF3 contacts the ribosome GTPase centre. The transfer RNA molecule translocates from the peptidyl site in state 1 to the exit site in state 2. This translocation is associated with a large conformational rearrangement of the ribosome. Because state 1 seems able to accommodate simultaneously both RF3 and RF2, whose position is known from previous studies, we can infer the release mechanism of class I RFs.     

ConA或PHA对鮎(Silurus asotus)皮肤和鳃粘液细胞密度的影响

用阿利新蓝-过碘酸雪夫氏试剂染色法(AB-PAS),对鲇(Silurus asotus)皮肤和鳃粘液细胞进行分类,研究ConA或PHA浸泡和注射刺激对鲇皮肤和鳃粘液细胞密度变化的影响.结果表明:(1)除鳃丝软骨Ⅴ型粘液细胞密度经浸泡刺激无显著增加外,无论采取ConA或PHA浸泡刺激还是注射刺激,皮肤中的Ⅰ型,Ⅳ型粘液细胞和鳃中的Ⅱ型和Ⅲ型粘液细胞密度都有显著增加.(2)经ConA注射或浸泡刺激后,皮肤中粘液细胞密度分别增加了64.2%和145%,鳃丝中粘液细胞密度分别提高了173%和220%;经PHA注射或浸泡刺激后,皮肤粘液细胞密度分别增加了67.8%和142%,鳃丝粘液细胞密度分别增加了108%和196%;经ConA或者PHA注射刺激,鳃丝软骨的粘液细胞密度都有显著增加,分别增加了68.8%和13.2%,浸泡刺激对粘液细胞密度都没有显著影响(3)ConA刺激较PHA刺激效果明显,浸泡刺激较注射刺激效果明显.     

A cryo-electron microscopic study of ribosome-bound termination factor RF2

Protein synthesis takes place on the ribosome, where genetic information carried by messenger RNA is translated into a sequence of amino acids. This process is terminated when a stop codon moves into the ribosomal decoding centre (DC) and is recognized by a class-1 release factor (RF). RFs have a conserved GGQ amino-acid motif, which is crucial for peptide release and is believed to interact directly with the peptidyl-transferase centre (PTC) of the 50S ribosomal subunit. Another conserved motif of RFs (SPF in RF2) has been proposed to interact directly with stop codons in the DC of the 30S subunit. The distance between the DC and PTC is approximately 73 A. However, in the X-ray structure of RF2, SPF and GGQ are only 23 A apart, indicating that they cannot be at DC and PTC simultaneously. Here we show that RF2 is in an open conformation when bound to the ribosome, allowing GGQ to reach the PTC while still allowing SPF-stop-codon interaction. The results indicate new interpretations of accuracy in termination, and have implications for how the presence of a stop codon in the DC is signalled to PTC.     

BMSCs对大鼠放射性皮肤损伤的治疗研究

目的探讨通过BMSCs(骨髓间充质干细胞)移植治疗放射性皮肤损伤。方法将放射性皮肤损伤的模型大鼠随机分为干细胞治疗组、阳性药治疗组和对照组。取BMSCs经体外培养后,加于Ⅲ度放射性皮肤损伤的异体大鼠创面上,以平均愈合时间和平均愈合速度为指标,观察各组动物损伤皮肤的修复情况。结果干细胞治疗组皮肤修复速度为(32.37士3.16)mm2/d;平均愈合时间为(20.03士3.95)/d,明显高于其他两组。且组织结构完整、瘫痕小。经统计学处理干细胞治疗组与对照组相比差异有统计学意义(P0.05)。结论利用同种异体动物干细胞培养物,进行放射性皮肤损伤的治疗有明显的效果,为放射性皮肤损伤的临床治疗提供了一条新途径。     

Variable expression of Ia antigens on the vascular endothelium of mouse skin allografts

Ia antigens are membrane-bound glycoproteins that play a part in antigen recognition and subsequent cell-cell interactions in the immune response. In the mouse they are coded for by the I region of the major histocompatibility complex H-2 and have been demonstrated on B lymphocytes, monocytes, activated T cells, macrophages and dendritic cells, including Langerhans cells. Ia-like antigens have also been detected on the vascular endothelium in man and on epidermal keratinocytes in rats but expression on the latter cells was induced by a graft-versus-host reaction or by contact hypersensitivity. In the mouse, previous studies have suggested that Ia antigens in skin are restricted to epidermal Langerhans cells and it was thought that these were the targets for Ia-dependent rejection of skin allografts. The results presented here show that Ia antigens in mouse allografts are also present on the vascular endothelium but their expression is variable and dependent on the immunological status of the recipient. These findings suggest that vascular endothelial cells can act as targets in Ia-incompatible skin allograft rejection.     

Analysis of T-cell subsets in rejection of Kb mutant skin allografts differing at class I MHC

The T-cell subpopulations which initiate and mediate tissue allograft rejection remain controversial. In the present study we attempted to identify the phenotype and function of the T-cell subset(s) primarily responsible for the rejection of skin allografts differing at a single class I locus in the major histocompatibility complex (MHC). We found that the rejection rates by B6 mice (H-2b) of four different class I mutant (Kbm) skin allografts form a distinct hierarchy. This hierarchy correlates strikingly and uniquely with the relative precursor frequencies of Lyt2+ interleukin-2-secreting T-helper cells reactive against the various Kbm mutants. To investigate the role of Lyt2+ T cells in the rejection of class I-disparate skin allografts directly, H-2b nude mice were engrafted with Kbm skin allografts and then reconstituted with L3T4+ or Lyt2+ T-cell subpopulations from syngeneic H-2b mice. Lyt2+ T cells were observed to be both necessary and sufficient for the rejection of class I-disparate Kbm skin allografts, whereas L3T4+ T cells were neither necessary nor sufficient. These results identify the Lyt2+ interleukin-2-secreting T-cell subset as the critical cell type determining the rejection rate of class I-disparate Kbm skin allografts.