Gamma chain required for naïve CD4+ T cell survival but not for antigen proliferation

Lymphoid homeostasis is required to ensure immune responsiveness and to prevent immunodeficiency. As such, the immune system must maintain distinct populations of na?ve T cells that are able to respond to new antigens as well as memory T cells specific to those antigens it has already encountered. Though both na?ve and memory T cells reside in and traffic through secondary lymphoid organs, there is growing evidence that the two populations may be regulated differently. We show here that na?ve T cell survival and memory T cell survival have different requirements for cytokines (including the interleukins IL-2, IL-4, IL-7, IL-9 and IL-15) that use the common cytokine receptor gamma chain (gamma c). Using monoclonal populations of antigen-specific CD4+ T cells, we found that na?ve T cells cannot survive without gamma c, whereas memory T cells show no such requirement. In contrast, neither na?ve nor gamma c-deficient memory T cells were impaired in their ability to proliferate and produce cytokines in response to in vivo antigenic stimulation. These data call into question the physiological role of gamma c-dependent cytokines as T cell growth factors and show that na?ve and memory CD4+ T cell survival is maintained by distinct mechanisms.     

Allergy to house dust and storage mites in children: epidemiologic observations

One hundred and fifty-two children affected by respiratory syndromes, probably due to allergy, underwent skin testing to a range of extracts including several different species of mites. The incidence of positive reactions to different allergens was studied in two groups: below and over 4 years, each including both outpatients and inpatients. The aetiologic role of mites has been evaluated considering positive skin tests to single species between and within families.     

Reference values for vital capacity and flow-volume curves from a general population study

A longitudinal epidemiological respiratory study has been started in the North of Italy to investigate the natural history of obstructive airways disease and the long-term effect of SO2 exposure. The first cross-sectional study was completed in this unpolluted area before the activation of a thermoelectric power plant (500 tons of SO2 produced daily). Follow-up surveys are planned after pollution emission starts for a period of ten years. A sample (n = 3289) representative of the general population was drawn from the villages of the area according to the different risks of pollution exposure. Subjects completed questionnaires and performed lung function tests, including forced expiratory (FVC) manoeuvres. For 801 'normal' subjects, prediction equations have been derived in age/sex groups for slow vital capacity (VC) and variables from the FVC manoeuvre. Comparisons with predictions of other studies are reported. Differences among FVC predictions were found, indicating that the use of different criteria for determination of the FVC manoeuvre end-point can affect results. In 'normals' VC was higher than FVC in older subjects. The difference between VC and FVC may be hypothesized as an epidemiological indication of the ageing effect on the mechanical properties of the ventilatory system.     

Effects of CD8 depletion on retinal soluble antigen induced experimental autoimmune uveoretinitis.

During the later stages of soluble-antigen (sAg)-induced experimental autoimmune uveoretinitis (EAU), an increase in the relative number of CD8+ lymphocytes has been observed at the site of inflammation in the retina. It has been suggested that these late-appearing CD8+ cells might down-regulate this acute disease process. To determine the role of the CD8+ cells in EAU, Lewis rats were depleted of CD8+ cells prior to and during disease and the enucleated eyes examined histologically. The spleen cells from CD8-depleted rats were also examined for their ability to respond to concanavalin A (Con A) and to allogeneic targets as determined by mixed lymphocyte reaction (MLR) and cytotoxicity assays. The results suggest that depleting CD8+ cells had no effect on the course of disease and that CD8+ cells do not play a crucial role in the immunoregulation of EAU.     

老年冠心病慢性闭塞病变的介入治疗探讨

目的探讨老年冠心病患者采用经皮冠状动脉介入(PCI)治疗的中短期疗效。方法对102例住院老年患者采用股动脉穿刺后,行球囊扩张,造影显示扩张满意后植入合适支架。术后随访6-32个月。结果102例患者术后临床症状均完全或基本完全缓解。本组患者有19例多支病变患者至少有一支慢性完全闭塞血管经努力而未能开通,无法植入支架。102例患者通过随访6-32个月,其中32例患者接受了冠脉造影复查,有17例患者分别于术后6个月至16个月又出现胸痛、胸闷症状。超声心动图检查射血分数(EF),心功能术后较术前明显改善,P<0.05。结论对冠状动脉慢性完全闭塞的老年患者,无论核素或超声检查是否存在存活心肌,均应尽量进行闭塞病变的介入治疗,以期改善患者的远期预后。     

旋入式髓内钉治疗肱骨干骨折

目的介绍和总结旋入式髓内钉治疗肱干骨折的方法及疗效.方法自2000年6月～2003年10月采用旋入式髓内钉顺行植入治疗肱骨干骨折12例,术后不用外固定,一周后进行适当功能锻炼;粉碎性骨折石膏固定6周后,开始功能锻炼.结果本组1 2例,均经3个月～2年随访,获得愈合,无并发症出现.按Neer功能评分标准,优良率100%.结论旋入式髓内钉治疗肱骨干骨折,固定牢靠,并发症少,愈合率高,功能恢复良好,是一种有效的治疗方法.     

豚鼠耳蜗Hensen细胞的分离、活性鉴定及其胞内静态游离Ca~(2+)分布

使用酶消化法及机械分离法对 Hensen细胞进行分离 ,置于倒置显微镜下用碘化丙啶及钙敏荧光染料 Fluo-3进行细胞活性鉴定并在激光扫描共聚焦显微镜下观察静息状态 Hensen细胞内的游离 Ca2 +的时空分布。结果证明 ,每个豚鼠耳蜗可以得到单离的 Hensen细胞 5～ 12个。细胞活性良好 ,可保持 5～ 6h。当细胞变性、坏死时可见一系列的形态学变化。对此得出几点判断 Hensen细胞活性的标准 :(1)细胞体呈卵圆形或椭圆形 ,大小可不一致 ;(2 )细胞膜完整 ,细胞边界清楚 ,折光现象明显 ;(3 )细胞浆清澈透明 ,无布朗运动 ,无溢出 ;(4 )细胞浆内的脂滴清晰可辨 ,折光现象明显 ;(5 )细胞无水肿 (即无气球样变 )。在静息状态下 ,Hensen细胞内的 Ca2 + 在细胞内分布不均匀 ,脂滴所在部位没有 Ca2 + 的分布。随时间延长 ,细胞内的 [Ca2 + ] i可小幅度振荡 ,但基本处于一种稳定状态。本工作为进一步对 Hensen细胞的其他特性进行研究打下了基础     

同种与异种骨基质明胶修复颅骨缺损的实验研究

以家兔颅顶骨直径１０ｍｍ园形骨缺损作为动物模型，分别植入同种（兔）、异种（人、猪、羊）的骨基质明胶。植入后４、８、１２、１６ｗ进行ｘ线摄片和组织学检查。结果显示，同种骨基质明胶无免疫排斥反应，具有良好的骨诱导作用，术后１２ｗ骨缺损完全修复；异种骨基质明胶植入早期，存在着不同程度的排斥反应，植骨后期（１２～１６ｗ），随着排斥反应的减轻，亦出现了诱导成骨。结果说明，如能改进异种骨基质明胶的制作方法，降低其抗原性，将具有重要的临床应用价值。     

促肝细胞生长素诱导人肝癌细胞（BEL－7402）凋亡

本文从细胞学、ＤＮＡ凝胶电泳、流式细胞术三方面研究促肝细胞生长素（ｐＨＧＦ）在体外对肝癌细胞增殖活性的影响。结果表明：ｐＨＧＦ对肝癌ＢＥＬ－７４０２细胞增殖有抑制作用，并存在剂量和时间相关性。其４８ｈ的半数抑制浓度（ＩＤ５０）为０．３７ｍｇ／ｍｌ±０．０４ｍｇ／ｍｌ。而３７℃灭活的ｐＨＧＦ对ＢＥＬ－７４０２细胞增殖在１５ｈ无抑制作用，在２４和４８ｈ抑制作用很弱（ＩＤ５０＞１．５ｍｇ／ｍｌ）。ＤＮＡ凝胶电泳结果表明，ｐＨＧＦ可诱导ＢＥＬ７４０２细胞产生细胞凋亡（Ａｐｏｐｔｏｓｉｓ）。流式细胞术（ＦＣＭ）结果显示：ｐＨＧＦ抑制ＢＥＬ－７４０２细胞增殖过程是先使细胞停留在Ｇ０／Ｇ１期，继而诱导细胞产生凋亡。后两项结果均显示ｐＨＧＦ对人肝癌细胞凋亡的诱导里时间和剂量相关性。     

额外小染色体与原发闭经(附4例报告)

我们发现4例原发闭经伴额外小染色体病例,其核型分别为;46,XX/47,XX mar;46,X,del(X)/47,X,del(X) mar;47,XX, mar;45,X/46,X, mar/46,X r.作者讨论了mar的发生率、起源、诊断、临床表现及产前诊断等问题.