三层式nCHAC/PLGA复合膜体外降解行为的研究

目的探讨引导组织再生性复合膜-纳米碳羟磷灰石/胶原/聚乳酸羟基乙酸复合膜(nCHAC/PLGA) 在体外的生物降解行为。方法根据牙周治疗的特点,功能分级材料nCHAC/PLGA膜制备成三层,即8wt％ nCHAC PLGA/4wt％nCHAC PLGA/PLGA。其中一面为多孔结构,利于细胞在其上生长;另一面表面光滑,籍此抑制细胞的粘附。以纯聚乳酸羟基乙酸(PLGA)膜作为对照,将样本浸泡在37℃人工唾液中,比较两者生物降解行为。结果膜重量持续减轻,nCHAC/PLGA三层式功能分级复合膜在4周后重量减少23．1％, 12周后减少88％;单层纯聚乳酸羟基乙酸膜在4周后重量减轻30．7％,12周后减轻98．9％。处理4周后,因纳米碳羟磷灰石的降解,介质中钙离子浓度显著增加。另外,浸泡nCHAC/PLGA膜的溶液pH值略高于浸泡纯PLGA膜者,提示nCHAC复合物可能对溶液中PLGA酸性产物具中和作用。实验过程中,测试样本整体原形能维持4周,8周和12周时变成粉末状。扫描电镜结果显示,随着浸泡时间延长,膜的8wt％ nCHAC PLGA多孔疏松面增加,PLGA致密光滑面亦出现小孔结构。结论复合膜的降解过程符合牙周修复的实际过程;此外,复合膜表面形成新的矿物结构,将对体内新骨再生起积极效应。     

γ干扰素cDNA在胃癌细胞中的表达研究

实验用构建的正向连入人ＩＦＮ－γｃＤＮＡ片段的重组表达载体ｐＭＡＭｎｅｏ－γ－ＩＦＮ，以Ｌｉｐｏ－ｆｅｃｔｉｎ介导法将重组载体转染入胃癌细胞７９０１中，挑选出Ｇ４１８抗性克隆，地塞米松诱导其分泌ＩＦｔＩ－γ经活性测定筛选出高分泌ＩＦＮ－γ的细胞株ＲＰＭ７９０１－７（１７２５ＩＵ／ｍｌ），Ｓｏｕｔｈｅｒｎｂｌｏｔ证实ＩＦＮ－γｃＤＮＡ确已导入该细胞株中。体外培养过程中，ＲｐＭ７９０１细胞与转染了对照质粒ｐＭＡＭｎｅｏ的细胞ｐＭ７９０１及野生型７９０１细胞在形态，生长能力等方面无明显差别，而经地塞米松诱导的ＲpＭ７９０１细胞则与之有显著差异。裸鼠体内接种显示，经诱导的ＲｐＭ７９０１细胞在致瘤性上显著低于野生型７９０１细胞及ｐＭ７９０１细胞。经基因转移后可高分泌ＩＦＮ－γ的肿瘤细胞为肿瘤的基因治疗提供了资料。     

顺行交锁髓内钉治疗肱骨骨折

目的探讨顺行交锁髓内钉治疗肱骨骨折的手术要点和治疗效果。方法回顾性分析2003年10月～2005年10月23例顺行肱骨交锁髓内钉治疗肱骨干中上段骨折。结果全部病例随访6个月～1年3个月,平均11个月。所有病例均骨性愈合,平均临床愈合时间为2.4个月。所有关节活动度均可。结论顺行交锁髓内钉治疗肱骨中段或中上段骨折,效果良好。     

用非同位素原位杂交组化在光镜和电镜水平观察前阿黑皮素mRNA在垂体的分布

用地高辛标记反意前阿黑皮素(pro-opiomelanocortin,POMC)cRNA探针原位杂交组化在光镜和电镜水平观察了POMC mRNA在大鼠垂体的分布,并比较了碱性磷酸酶(AKP)显色系统和辣根过氧化酶(HRP)显色系统在光镜水平上的敏感性.结果:POMC mRNA广泛地分布于垂体的中间叶和前叶.中间叶全部细胞均为POMC mRNA阳性.前叶中除前叶的腹侧缘和前叶与中间叶交界处阳性细胞较少外,都有较多的POMC mRNA阳性细胞分布.AKP显色系统比HRP显色系统敏感.在电镜水平,POMC mRNA主要分布于粗面内质网,少数分泌颗粒可能呈阳性反应,胞核未见阳性反应沉淀.文内还就阳性分泌颗粒在调节细胞合成功能方面可能起的作用进行了讨论.     

Antigen-specific production of interleukin (IL)-13 and IL-5 cooperate to mediate IL-4Ralpha-independent airway hyperreactivity

The pathogenesis of human asthma and the development of key features of pulmonary allergy in mouse models has been critically linked to IL-13. Analyses of the receptor components employed by IL-13 have shown that delivery of this cytokine to the airways of naive IL-4Ralpha gene targeted (IL-4Ralpha(-/-)) mice fails to induce disease, suggesting that this membrane protein is critical for transducing IL-13-mediated responses. The current study demonstrates that, in contrast to naive mice, T helper 2 bias, airways hyperreactivity (AHR) and tissue eosinophilia develop in Ovalbumin-sensitized IL-4Ralpha(-/-) mice and that these responses can be inhibited by the IL-13 antagonist sIL-13Ralpha2Fc. Therefore, antigen stimulation induces an IL-13-regulated response that is independent of IL-4Ralpha. To determine the role of IL-5 and eosinophils in the development of disease in antigen-exposed IL-4Ralpha(-/-) mice, pulmonary allergy was examined in mice deficient in both factors. IL-4Ralpha/IL-5(-/-) mice were significantly defective in their ability to produce IL-13 and failed to develop AHR, suggesting that IL-5 indirectly regulates AHR in allergic IL-4Ralpha(-/-) mice by an IL-13-dependent mechanism. Collectively, these results demonstrate that IL-13-dependent processes regulating the development of AHR and T helper bias persist in the in the lungs of allergic IL-4Ralpha(-/-) mice.     

精氨酸加压素对实验性神经细胞老化过程中细胞周期和细胞总蛋白的影响

采用小鼠神经母细胞瘤细胞无血清培养，建立神经细胞老化实验研究模型。以流式细胞光度术观察精氨酸加压素（ＡＶＰ）对老化过程中实验性神经细胞的细胞周期和细胞总蛋白的影响。结果发现ＡＶＰ可产生延缓细胞老化的细胞周期和细胞总蛋白的变化。提示ＡＶＰ通过使细胞周期、ＤＮＡ和细胞总蛋白等发生变化来发挥其延缓实验性神经细胞老化的作用。     

基于小波的海洛因成瘾者脉象异常分析

利用小波变换的方法，对15例海洛因成瘾者和15例正常人的脉搏信号的时频特征予以分析，根据用于显示离散二进小波变换的三维图形及等高线图，海洛因成瘾者与正常人脉象信号间时频特征的显著差异予以揭示，由此得出了初步的判据。根据该判据，15例海洛因成瘾者全部被检测出来，正常人有2例误检。研究结果表明，基于小波的多分辨率分析是提取脉搏信号特征的一种非常有效的方法。本文对于海洛因成瘾者的诊疗具有一定的价值。     

桥粒斑蛋白II在肿瘤组织中的表达

桥粒斑蛋白ＩＩ（ＤＰＩＩ）是一种新的上皮和上皮性肿瘤标记物。我们应用针对石蜡切片的抗ＤＰＩＩ单抗和抗细胞角蛋白（ＣＫ）单抗对２ｌ７例肿瘤作了免疫组织化学ＡＢＣ法染色的研究，结果：在１６３例上皮性肿瘤和双向分化的肿瘤中，１４７例表达ＤＰＩＩ，占９０．７％，９２例表达ＣＫ，占５６．４％。ＣＫ阳性染色全部位于细胞浆内，ＤＰＩＩ阳性染色则同时分布在细胞交界面上和细胞浆中。其他５４例不含桥粒的肿瘤均无ＤＰＩＩ和ＣＫ表达。结果表明，ＤＰＩＩ单抗是有用的含桥粒肿瘤的免疫组化探针。因ＤＰＩＩ不存在于一切含桥粒肿瘤，故在鉴别上皮性肿瘤时，ＤＰＩＩ单抗尚需与其他上皮标记物的抗体合并使用。     

The prevalence of dementia and Alzheimer's disease in Shanghai, China: impact of age, gender, and education

We report the prevalence rates for dementia and Alzheimer's disease (AD) obtained from a probability sample survey of 5,055 noninstitutionalized older persons in Shanghai, China. A two-stage procedure was used for case finding and case identification. A Chinese version of the Mini-Mental State Examination was used to determine cases of possible dementia. Three different cutoff points on this mental status test were used depending on the respondent's level of education. Clinical evaluations, based on functional assessments and psychiatric interview, medical and neurological examinations, three standardized mental status tests, and a selected group of psychometric tests, were made in the second stage of the study to ascertain the clinical diagnosis of dementia and AD utilizing the Diagnostic and Statistical Manual for Mental Disorders, edition 3 and National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, respectively. The prevalence rate of dementia in persons 65 years and older was 4.6%. Clinically diagnosed AD accounted for 65% of the subjects with dementia. These findings indicate that the prevalence of dementia in Shanghai is very much higher than figures published earlier for China and Japan, and at the lower part of the range of values reported for community residents in the United States and other Western countries, but less than half of that reported in the recently published survey of the elderly in East Boston. Increasing age, gender (female), and low education are each highly significant and independent risk factors for dementia. One hypothesis to explain the increased prevalence in elderly women who had received no formal education invokes the possibility of an effect of early deprivation, perhaps lowering brain "reserve," allowing the symptoms of dementia to appear at an earlier date during disease progression.     

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

Summary An immunoconjugate composed of natural interferon (nIFN) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN on the injected tumors. Further enhancement was obtained when nIFN or nIFN together with Mc5 (at a dose 10 times larger than that present in nIFN/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of¹²⁵I-nIFN/Mc5 by the tumors was greater and its elimination slower than for¹²⁵I-nIFN alone or conjugated to irrelevant mouse IgG₁. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.