心房颤动患者血清脑钠肽水平变化的临床研究

目的：探讨患者心房颤动（房颤,AF）发作时对血清脑钠肽水平的影响。方法：选择阵发性房颤组、持续性房颤组、对照组（窦性心律）患者各30例,观察各组血清脑钠肽水平;并对阵发性房颤组中心室率≤100 beats/min与心室率〉100 beats/min的患者进行亚组分析;观察阵发性房颤组复律后24 h和30 d血清脑钠肽水平。结果：阵发性房颤组和持续性房颤组血清脑钠肽水平明显高于对照组（P〈0.01）,房颤复律后血清脑钠肽水平很快下降。结论：血清脑钠肽水平在房颤发作时明显升高,血清脑钠肽水平的升高与房颤的发作有关。     

Genomic DNA methylation changes in response to folic acid supplementation in a population-based intervention study among women of reproductive age

Folate is a source of one-carbons necessary for DNA methylation, a critical epigenetic modification necessary for genomic structure and function. The use of supplemental folic acid is widespread however; the potential influence on DNA methylation is unclear. We measured global DNA methylation using DNA extracted from samples from a population-based, double-blind randomized trial of folic acid supplementation (100, 400, 4000 μg per day) taken for 6 months; including a 3 month post-supplementation sample. We observed no changes in global DNA methylation in response to up to 4,000 μg/day for 6 months supplementation in DNA extracted from uncoagulated blood (approximates circulating blood). However, when DNA methylation was determined in coagulated samples from the same individuals at the same time, significant time, dose, and MTHFR genotype-dependent changes were observed. The baseline level of DNA methylation was the same for uncoagulated and coagulated samples; marked differences between sample types were observed only after intervention. In DNA from coagulated blood, DNA methylation decreased (-14%; P<0.001) after 1 month of supplementation and 3 months after supplement withdrawal, methylation decreased an additional 23% (P<0.001) with significant variation among individuals (max+17%; min-94%). Decreases in methylation of ≥25% (vs. <25%) after discontinuation of supplementation were strongly associated with genotype: MTHFR CC vs. TT (adjusted odds ratio [aOR] 12.9, 95%CI 6.4, 26.0). The unexpected difference in DNA methylation between DNA extracted from coagulated and uncoagulated samples in response to folic acid supplementation is an important finding for evaluating use of folic acid and investigating the potential effects of folic acid supplementation on coagulation.     

菠萝果实发育相关RFD1基因的克隆及表达

Blast菠萝果实不同发育时期的cDNA文库测序结果,并用信息生物学软件和相关网站进行拼接和分析,设计特异引物RT-PCR．得到一个2750bp、编码761个氨基酸的全长基因序列,命名NRFD1。预测该蛋白是一个亲水性、且具有多个磷酸化位点的分泌性蛋白,可能位于叶绿体中。半定量PCR分析发现RFD1基因表达量在果实发育期不断增加,70d达到最高：而在70d果实的不同部位并没有显著差异性,仅果实外部略有增高。     

Four new coccidia (Apicomplexa: Eimeriidae) from the Plateau zokor,Myospalax baileyi Thomas (Rodentia: Myospalacinae), a subterranean rodent from Haibei area,Qinghai Province,China

Thirty-eight faecal samples from the Plateau zokor, Myospalax baileyi Thomas, collected in the Haibei Area, Qinghai Province, China, were examined for the presence of coccidia (Apicomplexa: Eimeriidae). Seventeen of 38 faecal samples (44.7%) were found to contain coccidian oöcysts representing four new species of Eimeria Schneider, 1875, and four of 17 (23.5%) infected zokors were concurrently infected with two or three of these eimerian species. The sporulated oöcysts of Eimeria myospalacensis n. sp. are ovoidal, 9.5–17.0 × 8.0–13.0 (mean 13.0 × 10.4) μm; a polar granule is present, oöcyst residuum is absent; sporocysts are ovoidal, 4.5–7.5 × 3.0–5.0 (mean 6.3 × 4.2) μm and have both a Stieda body and residuum. Oöcysts of Eimeria fani n. sp. are ellipsoidal to cylindroidal, 12.5–16.0 × 8.0–11.0 (mean 14.6 × 9.9) μm; a polar granule is present, but micropyle and residuum are lacking; sporocysts are ovoidal, 4.5–7.5 × 3.0–5.3 (mean 6.7 × 4.4) μm; a residuum and a Steida body are present. Oöcysts of Eimeria baileyii n. sp. are ellipsoidal, 15.0–23.0 × 12.0–18.0 (mean 18.2 × 13.7) μm; a polar granule is present but oöcyst residuum is absent; sporocysts are ovoidal, 8.0–11.0 × 5.0–7.0 (mean 9.5 × 5.9) μm and have both a Stieda body and residuum. Oöcysts of Eimeria menyuanensis n. sp. are ovoidal, 12.5–21.0 × 11.0–18.0 (mean 17.1 × 14.6) μm, with a distinct micropyle c.2.5 μm wide; a polar granule is present but a residuum is absent; sporocysts are ovoidal, 8.0–12.0 × 5.0–7.0 (mean 10.2 × 6.4) μm, and have both a Stieda body and residuum.     

食管癌前细胞DNA、端粒酶含量及多基因表达产物的定量检测

为探讨食管癌高发区人群食管上皮癌变过程中的早期分子改变及早期癌变机理.应用流式细胞术和免疫荧光技术及碘化丙啶DNA荧光染色方法,对食管上皮癌前细胞的DNA含量、端粒酶含量和多个基因p53、p16、cyclin D1蛋白质表达进行了定量检测.检测结果发现,DNA含量在癌变形成时明显增加,异倍体率为87.9%;p53蛋白积聚发生在癌变早期,在癌细胞组的阳性率为100%（5/5）;抑癌基因p16在癌变早期有明显缺失;癌基因cyclin D1及端粒酶阳性率在癌细胞组都为100%（分别为6/6,7/7）.研究结果表明：在癌变早期,DNA含量及异倍体率增加,癌基因cyclin D1表达增高,抑癌基因p16缺失及p53蛋白积聚,端粒酶含量也明显增高,在癌形成时已有多个分子事件发生.     

回转模拟失重对心肌成纤维细胞Ⅰ型胶原代谢的影响

为探讨模拟失重对心肌成纤维细胞Ⅰ型胶原代谢的影响 ,本研究采用回转器模拟失重效应 ,通过免疫细胞化学和反转录聚合酶链式反应 (RT PCR)研究了回转模拟失重对原代培养的新生大鼠心肌成纤维细胞Ⅰ型胶原蛋白及mRNA表达 ,以及胶原降解抑制物———金属蛋白酶组织抑制因子 (Tissueinhibitorofmetallopro teinase ,TIMP)mRNA表达的影响。免疫细胞化学染色显示回转组Ⅰ型胶原蛋白沉积增加 ;RT PCR分析显示Ⅰ型胶原α1链 (TypeⅠcollagenα1chain ,ColⅠA1)mRNA表达没有明显变化 ,TIMP 1、TIMP 2及TIMP 3的mRNA表达均增强。提示在回转模拟失重条件下 ,心肌成纤维细胞Ⅰ型胶原蛋白沉积增加 ,作为胶原降解抑制物的TIMP可能是造成胶原沉积的原因     

用激光共聚焦扫描技术研究昆虫触角叶的雌雄异构性

【目的】本研究探讨用激光共聚焦扫描显微镜对昆虫触角叶内结构的扫描技术。【方法】选取鳞翅目斜纹夜蛾Spodoptera litura, 蜚蠊目美洲大蠊Periplaneta americana和鞘翅目松墨天牛Monochamus alternatus, 仔细解剖得到昆虫完整脑组织, 经过Lucifer yellow染色、戊二醛固定、梯度酒精脱水和透明等一系列处理后, 用激光共聚焦扫描显微镜对昆虫触角叶结构进行分层扫描。【结果】结果显示: 经该方法处理后在激发光488 nm下能清晰扫描出昆虫触角内典型结构神经纤维球, 并且可清晰看到这3种昆虫雄性触角叶结构内的扩大型神经纤维球复合体(macroglomerular complex, MGC), 而在相应雌性昆虫体内都没有此复合体。另外通过5 μm分层扫描得到斜纹夜蛾、美洲大蠊和松墨天牛的触角叶平均厚度分别为130, 235和115 μm, 神经纤维球数量分别为35, 59和39个。【结论】激光共聚焦扫描技术是获得昆虫触角叶内部结构的一个可行方法。     

Hypomethylation of Serum Blood Clot DNA,but Not Plasma EDTA-Blood Cell Pellet DNA,from Vitamin B12-Deficient Subjects

Vitamin B12, a co-factor in methyl-group transfer, is important in maintaining DNA (deoxycytidine) methylation. Using two independent assays we examined the effect of vitamin B12-deficiency (plasma vitamin B12<148 pmol/L) on DNA methylation in women of childbearing age. Coagulated blood clot DNA from vitamin B12-deficient women had significantly (p<0.001) lower percentage deoxycytidine methylation (3.23±0.66%; n = 248) and greater [3 H]methyl-acceptance (42,859±9,699 cpm; n = 17) than DNA from B12-replete women (4.44±0.18%; n = 128 and 26,049±2,814 cpm; n = 11) [correlation between assays: r = –0.8538; p<0.001; n = 28]. In contrast, uncoagulated EDTA-blood cell pellet DNA from vitamin B12-deficient and B12-replete women exhibited similar percentage methylation (4.45±0.15%; n = 77 vs. 4.47±0.15%; n = 47) and [3 H]methyl-acceptance (27,378±4,094 cpm; n = 17 vs. 26,610±2,292 cpm; n = 11). Therefore, in simultaneously collected paired blood samples, vitamin B12-deficiency was associated with decreased DNA methylation only in coagulated samples. These findings highlight the importance of sample collection methods in epigenetic studies, and the potential impact biological processes can have on DNA methylation during collection.     

鞭角华扁叶蜂对自然生境柏木挥发物释放的影响

植物挥发物（Volatile organic compounds;VOCs）在植物抵御害虫侵袭的过程中具有重要作用。本研究以重庆市云阳县长江林场人工林中健康和受害柏木为研究对象,通过VOCs测定分析发现鞭角华扁叶蜂虫害发生之前,两种柏木共计有37种VOCs成分,主要为萜类化合物,其次为醇、酯、醛、烷烃等类化合物;其中健康柏木特有驱赶作用的2-莰醇（龙脑）,受害柏木特有吸引作用的顺式-2-癸烯醛,其余35种为共有成分;各成分浓度在两种柏木中存在较大差异。虫害发生之后,两种柏木共计有32种VOCs成分,而2-莰醇、顺式-2-癸烯醛、薄荷醇、臭樟脑和α-石竹烯等5种成分消失;许多成分的浓度变化趋势与虫害发生前的相反。结果表明健康与受害柏木VOCs释放的差异可能是柏木能否抵御鞭角华扁叶蜂侵害的主要防御机制之一,这将为优良抗虫柏木选育提供理论依据和参考指标。