以杯[4]芳烃衍生物为载体的钾离子选择电极的研究

目的：研制新的以杯[4]芳烃衍生物为载体的PVC膜钾离子选择电极。方法：以3种杯[4]芳烃衍生物为载体，癸二酸二辛酯或邻苯二甲酸二辛酯为增塑剂，四（4－氯）苯硼钾为离子定域体制得了PVC膜钾离子选择电极，测试了该类电极对钾离子的响应性能和对7种阳离子的选择性系数。结果：以5，11，17，23－四叔丁基－25，26，27，28－四[2-(乙氧基羰基）苄氧基]杯[4]芳烃为载体所制得的电极（电极Ⅰ）对钾离子有良好的能斯特响应，该电极的选择性系数优于电极Ⅱ和Ⅲ。分别用电极Ⅰ，Ⅱ，Ⅲ对青霉素V钾中的钾含量进行了测定，其结果均与原子吸收法基本一致。结论：所制得的上述电极是一类新的钾离子选择电极，有实用价值。     

与时俱进 全面开展生活方式教育

该文从疾病谱和死因谱的改变、医学模式的转变、卫生经费的降低、自我保健意识的改变四个角度,论述了全面开展 生活方式教育的必要性和重要性;从以社区为依托、以医院为基础、以生活方式为指导三个方面,探讨了生活方式教 育的工作模式.     

Expression and biological effects of high levels of serum IgE in epsilon heavy chain transgenic mice

We have generated and examined transgenic mice carrying a rearranged immunoglobulin transgene coding for the heavy chain of an IgE antibody. These mice produce the secreted form of the recombinant epsilon heavy chain. Serum IgE levels were increased at least 100-fold over control values. Transgenic epsilon mRNA was detected in spleen and thymus, not in liver and heart. Transgenic epsilon production in vitro was slightly up-regulated by T cells, but not affected by interleukin 4 in vitro or Nippostrongylus infestation in vivo. The B cell and T cell compartments and antigen-specific IgE, IgG1 and IgM responses as well as the increase in endogenous IgE after Nippostrongylus infestation in transgenic mice were normal. These data indicate that the presence of high levels of transgenic IgE did not induce class-specific suppressive mechanisms. Transgenic IgE bound to Fc epsilon receptor type I and Fc epsilon receptor type II and mediated histamine release from mast cells in vitro and an allergic skin reaction in vivo. It inhibited an ovalbumin-specific skin reaction in ovalbumin-immunized transgenic mice only during the initial phases of the immune response. This result has a bearing on the feasibility of immune therapy of allergic diseases with substances that block binding of IgE to its receptors.     

Quantitative SPECT leads to improved performance in discrimination tasks related to prodromal Alzheimer's disease.

We investigated the impact of the quantitation and reconstruction protocol on clinical tasks. The performance of standard clinical reconstruction procedures in discrimination tasks related to the diagnosis of prodromal Alzheimer's disease (AD) was compared with the performance of a quantitative approach incorporating improved corrections for scatter, attenuation, intrinsic spatial resolution, and distance-dependent spatial resolution. METHODS: Seventeen normal controls (normal group), 56 subjects who did not have dementia, who did have memory problems, but who did not develop AD within 5 y of follow-up (questionable group), and 27 subjects who did not have dementia, who did have memory problems, and who did develop AD over the follow-up period (converter group) were considered in this study. (99m)Tc-hexamethylpropyleneamine oxime SPECT and MRI studies were performed for each subject at baseline. The standard quantitation protocol (STD), routinely used in our clinic, consisted of Compton window scatter correction followed by filtered backprojection with attenuation correction using a uniform attenuation map. In the improved quantitative approach (QUAN), projections were corrected for scatter by use of a general spectral method and reconstructed by use of ordered-subset(s) expectation maximization, incorporating corrections for collimator response and attenuation using both a uniform attenuation map (QUANunif) and a nonuniform attenuation map (QUANnonunif). Mean SPECT activity concentration and MRI volume were estimated for 7 structures: rostral anterior cingulate gyrus, caudal anterior cingulate gyrus, posterior cingulate gyrus, hippocampus, basal forebrain, amygdala, and the banks of the superior temporal sulcus. Data were analyzed by pairwise discriminant analysis, and performance in binary group discrimination was measured by correlated receiver-operating-characteristic analysis. RESULTS: The use of QUANnonunif yielded a small but systematic improvement in discrimination accuracy for normal versus converter groups (accuracy or area under the receiver-operating-characteristic curve [Az], 0.965), normal versus questionable groups (Az, 0.973), and questionable versus converter groups (Az, 0.881) compared with the results obtained with QUANunif (Az, 0.955, 0.962, and 0.866, respectively). Discrimination performance was significantly lower (P < 0.05) with STD than with QUAN in all 3 tasks (Az with STD, 0.906, 0.878, and 0.768, respectively). MRI volume estimation led to a lower overall performance in all 3 tasks than did QUANnonunif (Az with MRI, 0.947, 0.917, and 0.872, respectively). CONCLUSION: Improved quantitative image reconstruction with accurate compensation for scatter, attenuation, and variable collimator response led to significantly better performance in discrimination tasks related to the diagnosis of prodromal AD than did standard clinical reconstruction procedures. The use of a nonuniform brain attenuation map yields a small improvement in discrimination accuracy.     

Tuberculosis in healthcare workers caring for a congenitally infected infant.

OBJECTIVE: To assess the extent of nosocomial transmission of tuberculosis among infants, family members, and healthcare workers (HCWs) who were exposed to a 29-week-old premature infant with congenital tuberculosis, diagnosed at 102 days of age. DESIGN: A prospective exposure investigation using tuberculin skin test (IST conversion was conducted. Contacts underwent two skin tests 10 to 12 weeks apart. Clinical examination and chest radiographs were performed to rule out disease. Isoniazid prophylaxis was administered to exposed infants at higher risk. SETTING: A neonatal intensive care unit in an urban hospital in Brussels, Belgium. PARTICIPANTS: Ninety-seven infants, 139 HCWs, and 180 visitors. RESULTS: Newly positive TST results occurred in HCWs who had been in close contact with the infant. Six (19%) of 32 primary care nurses and physicians had TST conversions and received treatment. Among the 97 exposed infants, 85 were screened and 34 were identified as at higher risk of infection. Of these, 27 received preventive isoniazid. None of the infants and none of the 93 other infants' family members evaluated were infected. CONCLUSIONS: Congenital tuberculosis in an infant poses a risk for nosocomial transmission to HCWs. Delayed diagnosis of this rare disease and close proximity are the most important factors related to transmission.     

结肠回肠反流与回肠黏膜结肠化相关性的实验研究

目的探讨结肠回肠反流后回肠末端黏膜结肠化的机制.方法取SD大鼠60只,均为雄性,体重25¨3∞g,随机分为实验组和对照组,分别进行末端回肠-盲肠侧侧吻合术或回肠末端手术缝线,2个月后处死动物并取组织进行观察.结果实验组术后一般状况良好.大体形态学观察:实验组回肠末端黏膜表现为绒毛萎缩、间距增宽、沟变浅、光滑性增强.病理组织学:实验组表现为黏膜绒毛萎缩、间距增宽、沟变浅、上皮细胞变短、杯状细胞增多.电镜观察:实验组可见绒毛变小、变短或脱落;微绒毛变短、分布不均匀;杯状细胞数目在非坏死区增多.结论结肠-回肠反流后可导致回肠末端黏膜结肠化的变化,它可能是慢性末端回肠炎的发病基础或前期表现.     

人源化抗体构建过程中假链的产生及应对策略

目的在人源化抗体构建过程中，采用方便、快捷的分子克隆手段。消除SP2／0内源性畸形轻链转录本以获得正确的轻链cDNA。方法在mRNA抽提时，不用常规的TRIZOL法抽提总RNA，而采用经腹腔培养。生长状态良好的杂交瘤细胞。用QIAGEN公司Oligotex Direct mRNA Purification Kit，将polyA^＋的mRNA富集。可有效减少畸变转录本的含量，提高功能型mRNA的丰度。利用polyA^＋RNA。采用RT-PCR，我们成功地克隆到了轻链可变区序列，序列分析证实读码框完全正确，属于轻链可变区基因。结果NCBI数据库BLAST显示。克隆的基因序列符合小鼠lg可变区特征，具有正确的CDR和FR功能区及VJ连接区。结论采用polyA^＋ mRNA富集技术，成功克隆获得阻断型抗人CD154 mAb（4F1）单克隆抗体的轻链、重链可变区基因，成功地消除了SP2／0内源性畸形转录本对免疫球蛋白功能性轻链基因的影响。