恶性疟原虫裂殖子表面蛋白-2 DNA疫苗诱导小鼠T淋巴细胞的增殖

目的 探讨疟原虫FCC-1／HN株泉殖子表面蛋白-2(MSP-2)DNA疫苗在小鼠体内诱导免疫应答的特性及抗感染的保护性免疫机制。方法 将重组真核表达质粒PBK／MSP-2经骨骼肌注射BALB／c小鼠。小鼠经DNA疫苗免疫8周后，用流式细胞仪分析脾脏T淋巴细胞的分化，并体外培养脾脏细胞，用夹心ELISA法测定IFN-γ和IL-2的产生。结果 与对照组相比，疫苗组CD4^ CD8^ 淋巴细胞有显著性的增高，体外培养的脾脏细胞IFN-γ有高浓度的分泌。结论 恶性疟原虫FCC-1／HN MSP-2 DNA疫苗诱导了一个TH1的免疫疫答类型。     

高效抗逆转录病毒治疗对AIDS患者MCP-1和MSP水平的影响

目的:研究高效抗逆转录病毒治疗(HAART)对AIDS患者血清中MCP-1、MSP水平的影响。方法:采用ELISA法检测40例经HAART3个月的国内AIDS患者及84例经HAART3至6年的德国患者血清MCP-1、MSP的水平,荧光定量PCR测定HIV-RNA滴度,流式细胞术检测CD4 T细胞计数。结果:HIV-1感染者血清MCP-1的水平显著高于正常人群(P<0.01),MSP则显著低于正常人群(P<0.01);经短期HAART(3月)后,MCP-1水平下降(P<0.01),MSP无明显改变;长期HAART(3至6年)后MCP-1水平显著升高(P<0.01),而MSP显著下降(P<0.01),MCP-1和MSP水平的变化呈负相关(r=-0.99,P=0.029)。结论:MCP-1、MSP与AIDS病程进展有密切关系,HAART对AIDS患者MCP-1、MSP水平有显著的改变,进而改善患者病程进展。     

Epigenetic and genetic alterations in duodenal carcinomas are distinct from biliary and ampullary carcinomas

BACKGROUND & AIMS: Carcinomas of the extrahepatic bile ducts, ampulla of Vater, and duodenum are uncommon, and their epigenetic and genetic alterations are not well characterized. METHODS: We therefore compared the methylation profile and genetic alterations in 18 extrahepatic biliary, 9 ampullary, and 12 duodenal carcinomas. We evaluated methylation at p16, p14, and human Mut L homologue (hMLH1) by methylation- specific PCR (MSP), and at cyclooxygenase 2 (COX2), O(6)-methyl-guanine methyltransferase (MGMT), estrogen receptor (ER), retinoic acid receptor beta 2 (RAR beta), and T-type calcium channel (CACNA1G) genes, and methylated in tumor 1 (MINT1), MINT2, MINT25, MINT27, and MINT31 loci by combined bisulfite restriction analysis (COBRA); mutation of K-ras, p53, p16, and p14 genes by sequencing; loss of heterozygosity of chromosome 9p; and microsatellite instability (MSI). RESULTS: Duodenal carcinomas were methylated more frequently or had increased methylation densities than biliary carcinomas at p14 (P = 0.04), hMLH1 (P = 0.04), MGMT (P = 0.01), MINT1 (P = 0.01), MINT25 (P = 0.01), MINT27 (P = 0.001), RAR beta (P = 0.03), and ER (P = 0.001), and than ampullary carcinomas at RAR beta (P = 0.02) and ER (P = 0.03). In contrast, the methylation profiles of biliary and ampullary carcinomas were not statistically different. Simultaneous methylation of 3 or more CpG islands (CpG island methylator phenotype-high) was more common in duodenal cancers (P = 0.004). MGMT methylation was associated with G-to-A mutation in K-ras (P = 0.006), and hMLH1 methylation was associated with MSI-high (P = 0.01). CONCLUSIONS: Our findings indicate that the methylation profile and genetic alterations of duodenal carcinomas are distinct from biliary and ampullary carcinomas, and that tumor-specific methylation is associated with gene mutation and MSI.     

Naturally acquired antibody responses to the components of the Plasmodium falciparum merozoite surface protein 1 complex

Merozoite surface protein 6 (MSP6) and 7 (MSP7) of Plasmodium falciparum are peripheral membrane proteins whose cleaved products, MSP636, MSP722 and MSP719, are found on the merozoite surface as components of a non-covalently bound complex which also contains four polypeptides derived from merozoite surface protein 1 (MSP1). We have expressed both the precursor regions and the processed mature products of MSP6 and MSP7 in Escherichia coli and showed that these recombinant proteins react with human immune sera. In a set of sera collected from individuals living in malaria-endemic areas of Southern-central Vietnam, antibodies to the mature polypeptides of MSP636 and MSP722 were detected in 50.6 and 85.6% of the serum samples, whereas antibodies to the precursor regions of MSP6 and MSP7 were detected in only 12.1 and 42.5% of the serum samples, respectively. The predominant subclass of anti-MSP6 antibodies was IgG1, whereas the predominant subclass of anti-MSP7 antibodies was IgG3. In the same set of serum samples, the antibody responses to MSP119 are predominantly IgGI, whereas antibodies to merozoite surface protein 4 (MSP4) are mainly IgG3. This data is consistent with the proposition that, during malaria infection, variable proteins induce responses that are predominantly of the IgG3 isotype, and conserved proteins induce responses that are predominantly IgG1. The antibodies to MSP6, MSP7 and MSP119 all decreased at the time of infection, but increased during the convalescent period. No correlation was observed between the antibodies at the commencement of the study and absence of parasitaemia during surveillance in this population.     

Sporadic Colon Cancer: Mismatch Repair Immunohistochemistry and Microsatellite Instability in Omani Subjects

Background Colorectal carcinoma (CRC) is the most common gastrointestinal malignancy in the world, and there are suggestions of a particularly high incidence in the Middle East, including those of African origin. Defects in DNA mismatch repair (MMR) systems are involved in the carcinogenesis of both sporadic and inherited human cancers. We assessed colonic cancers in an attempt to identify tumors with DNA MMR deficiency and microsatellite instability (MSI). Additionally, we tested the ability of cell cycle regulator p16 that effects cell proliferation and can be abrogated by hypermethylation of the promoter region. Methods We reviewed the charts of 756 patients who were referred to the Oman major colonoscopy unit of the Sultan Qaboos University Hospital and Royal Hospital from the years 2000 to 2004. Colon cancer tissue was assayed using immunohistochemistry for expression of hMLH1 and hMSH2, and a panel of five pairs of microsatellite primers (NR21, NR22, NR24, BAT25, and BAT26) for MSI-H analysis and additional dinucleotide markers (D17S250, D5S346, and D2S123) used for MSI-L. The expression status of MMR genes and MSI was correlated with cancer stage, location, and histology. A total of 49 tumors were analyzed for histopathology, MSI, and hMLH1/hMSH2 protein expression analysis. The methylation status of the p16 promoter was determined by methylation-specific polymerase chain reaction (PCR). Results The mean age for the carcinomas was 52.2 years and 53% of the patients were male. The majority of the tumors were left-sided. The information currently available indicates that there is an incidence of 4.7% colon cancer (49/1036) and 12.1% (126/1290) colon adenoma among the cases who underwent colonoscopy at these centers. The rate of MSI-H was 12.2% (n = 6), which appears to be the same as previously reported in literature. Eight of 49 tumors (16.3%) were MMR defective by IHC. Defects in the mismatch repair genes hMLH1 and hMSH2 were found in four (66.7%) and two (33.3%) of CRCs MSI-H cases, respectively. Defects in hMLH1 expression in tumors were commonly associated with moderate differentiation. The p16 promoter was methylated in 4% of tumors. Conclusion This is the first genetic study of CRC in this region of the world to demonstrate the incidence of MSI, p16 methylation, and hMLH1 and MSH2 expression in the Omani population. In addition, a relatively high frequency of CRC in younger age groups was noted, which is an important observation. The left-sided preponderance of MMR defective tumors was mostly associated with hMLH1, and with possible loss of hMSH2 expression, an observation that differs from studies on other populations. In conclusion, although the overall rate of CRC is unknown in this region, the frequency of MSI in CRC in this region appears to be the same as in Caucasians in the USA.     

基于SD卡的动态心电系统研究

目的：研制使用SD卡作为存储介质的动态心电系统。方法：使用MSP430F449单片机采集3通道的心电信号,通过同步通讯接口,记录在SD卡上,在计算机上进行数据的回放和分析。结果：构建了基于SD卡的便携式动态心电系统。使用SD卡,可以提高动态心电系统的存储能力。结论：提供了一个低成本、高性能的动态心电系统的解决方案。     

无线式病房体温监测仪的设计

目的:设计一种无线遥测式电子温度计,可以使医护人员在不接触患者的情况下监测患者的体温.方法:该系统以新型单片机MSP430F413为核心;温度采集传感器采用热敏电阻;模数转换时利用单片机内的比较器和定时器进行斜边A/D转换;无线通讯部分使用NRF2401芯片;系统与计算机之间采用串行通信方式进行通讯.结果:该系统在-40～85℃范围内工作,在体温范围内精度达到0.1℃.结论:该系统可以准确地测量体温,同时通过无线通讯方式把数据传送到接收端,再通过串行通讯方式传递给计算机.计算机记录体温变化曲线提供给医护人员参考.     

应力性骨折动物模型建立方法的研究及评价

目的：研制一种动物疲劳性训练实验系统,以期快速建立应力性骨折动物模型。方法：采用MSP430F4270单片机控制高压发生器输出频率和时长可调的高压脉冲,迫使实验兔进行跳跃运动;训练周期结束后,采用骨闪烁显像术对建模方法进行评价。结果：应用该系统成功地建立了兔应力性骨折模型。结论：该系统能方便地调节实验动物的训练强度和训练量,工作稳定,可靠性高,具有建模时间短、成功率高等优点。     

提高电子血压计个体适应性检测能力的研究

本文首先分析了基于示波法的电子血压计存在的局限性．在脉搏信号特点分析的基础上提出了利用小波变换对信号特征点进行识别的方法．并且根据心率调整重采样率,提高了固定尺度下特征点识别的能力。经样机试验证明,该方法使电子血压计测量具有较好的个体适应性和稳定性。     

一种新型的阻抗式呼吸检测系统

介绍了一种新型的阻抗式呼吸检测方法的设计与实现。系统采用生物阻抗法．在空间上通过增加电极．将多路呼吸信号进行空域叠加滤波．以提高信号的信噪比．并通过传统的软硬件滤波进一步增强抗干扰能力。样机系统基于MSP430单片机．实现了便携式低功耗设计。对样机的人体实验表明,其抗心动、血流和运动等干扰的性能较好,系统运行稳定。