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[目的]建立国境口岸不同蚊种的细胞色素C氧化酶亚基I(COI)分子和氨基酸鉴定方法并分析其系统进化关系。[方法]设计1对扩增COI部分编码区的PCR引物,对广州机场、江门和湛江等国境口岸采集的致倦库蚊、三带喙库蚊、白纹伊蚊、中华按蚊、骚扰阿蚊等成蚊和实验室喂养的蚊幼虫进行PCR扩增和序列测定,分析COI核苷酸和氨基酸的系统进化关系。[结果]5种蚊种的COI基因扩增片断长度均为415bp,A+T含量为68.77%-70.6%。同源性比较表明,不同蚊种间COI片断碱基变异颠换数都明显高于转化数,核苷酸序列及其编码的氨基酸序列同源性分别为85.1%-93.7%和92.0%-99.3%。COI核苷酸系统进化关系显示,所有蚊虫的COI分子鉴定与其形态学结果吻合,但骚扰阿蚊位于一单独的分支上,其亲缘关系与其它蚊种最远。COI基因编码的氨基酸系统进化与蚊虫形态学亲缘关系一致,库蚊属、伊蚊属、阿蚊属聚类为库蚊亚科,中华按蚊与其它蚊种的亲缘关系最远。[结论]建立的COI核苷酸和氨基酸鉴别技术可成功地应用于国境口岸范围内成蚊和幼蚊的属和种的区分,后者更能区分高级分类阶元亚科和正确反映蚊虫的系统发育关系。这可以弥补蚊虫形态特征信息量的不足等传统分类系统的缺点,为广东口岸和其它国境口岸范围内外来的或新发现的蚊种的鉴别提供了分子水平的技术依据。 相似文献
855.
鄂西香茶菜Rabdosia henryi(Hemsl.)Hara为唇形科香茶菜属植物,广泛分布于河南、湖北、四川、贵州、陕西、山西、河北等省。全草具有抗菌、消炎等作用,民间用于治疗急性黄疸型肝炎、急性胆囊炎、跌打损伤、毒蛇咬伤、脓疱疹等。其药理作用未见报道。本课题组对鄂西香茶菜粗制剂进行了药理作用的研究,结果表明其对体内和体外的艾氏腹水癌(Ehrlichascites carcinoma,ECA)肿瘤细胞有明显的抑制作用。从鄂西香茶菜中提取的单体鄂西香茶菜素(简称鄂西素)属于二萜类化合物[1]。笔者采用多种动物移植性肿瘤模型,观察鄂西素对动物肿瘤的抑制作用,… 相似文献
856.
Influence of tap water quality and household water use activities on indoor air and internal dose levels of trihalomethanes 总被引:3,自引:0,他引:3
Nuckols JR Ashley DL Lyu C Gordon SM Hinckley AF Singer P 《Environmental health perspectives》2005,113(7):863-870
Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre-water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and post-activity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities. 相似文献
857.
Morgan MK Sheldon LS Croghan CW Jones PA Robertson GL Chuang JC Wilson NK Lyu CW 《Journal of exposure analysis and environmental epidemiology》2005,15(4):297-309
As part of the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study, we investigated the exposures of preschool children to chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol (TCP) in their everyday environments. During this study, the participants were still able to purchase and apply chlorpyrifos at their homes or day care centers. Participants were recruited randomly from 129 homes and 13 day care centers in six North Carolina counties. Monitoring was performed over a 48-h period at the children's homes and/or day care centers. Samples that were collected included duplicate plate, indoor and outdoor air, urine, indoor floor dust, play area soil, transferable residues (PUF roller), and surface wipes (hand, food preparation, and hard floor). The samples were extracted and analyzed by gas chromatography/mass spectrometry. Chlorpyrifos was detected in 100% of the indoor air and indoor floor dust samples from homes and day care centers. TCP was detected at homes and day care centers in 100% of the indoor floor dust and hard floor surface wipe, in >97% of the solid food, and in >95% of the indoor air samples. Generally, median levels of chlorpyrifos were higher than those of TCP in all media, except for solid food samples. For these samples, the median TCP concentrations were 12 and 29 times higher than the chlorpyrifos concentrations at homes and day care centers, respectively. The median urinary TCP concentration for the preschool children was 5.3 ng/ml and the maximum value was 104 ng/ml. The median potential aggregate absorbed dose (ng/kg/day) of chlorpyrifos for these preschool children was estimated to be 3 ng/kg/day. The primary route of exposure to chlorpyrifos was through dietary intake, followed by inhalation. The median potential aggregate absorbed dose of TCP for these children was estimated to be 38 ng/kg/day, and dietary intake was the primary route of exposure. The median excreted amount of urinary TCP for these children was estimated to be 117 ng/kg/day. A full regression model of the relationships among chlorpyrifos and TCP for the children in the home group explained 23% of the variability of the urinary TCP concentrations by the three routes of exposure (inhalation, ingestion, dermal absorption) to chlorpyrifos and TCP. However, a final reduced model via step-wise regression retained only chlorpyrifos through the inhalation route and explained 22% of the variability of TCP in the children's urine. The estimated potential aggregate absorbed doses of chlorpyrifos through the inhalation route were low (median value, 0.8 ng/kg/day) and could not explain most of the excreted amounts of urinary TCP. This suggested that there were other possible sources and pathways of exposure that contributed to the estimated potential aggregate absorbed doses of these children to chlorpyrifos and TCP. One possible pathway of exposure that was not accounted for fully is through the children's potential contacts with contaminated surfaces at homes and day care centers. In addition, other pesticides such as chlorpyrifos-methyl may have also contributed to the levels of TCP in the urine. Future studies should include additional surface measurements in their estimation of potential absorbed doses of preschool children to environmental pollutants. In conclusion, the results showed that the preschool children were exposed to chlorpyrifos and TCP from several sources, through several pathways and routes. . 相似文献
858.
Antiherpetic activities of flavonoids against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2)in vitro 总被引:2,自引:0,他引:2
Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant, anticancer, bactericidal, and anti-inflammatory. We carried out anti-herpetic assays on 18 flavonoids in five classes and a virus-induced cytopathic effect (CPE) inhibitory assay, plaque reduction assay, and yield reduction assay were performed. When flavonoids were applied at various concentrations to Vero cells infected by HSV-1 and 2, most of the flavonoids showed inhibitory effects on virus-induced CPE. Among the flavonoids, EC, ECG (flavanols), genistein (isoflavone), naringenin (flavanone), and quercetin (flavonol) showed a high level of CPE inhibitory activity. The antiviral activity of flavonoids were also examined by a plaque reduction assay. EC, ECG, galangin, and kaempferol showed a strong antiviral activity, and catechin, EGC, EGCG, naringenin, chrysin, baicalin, fisetin, myricetin, quercetin, and genistein showed moderate inhibitory effects against HSV-1. In these experiments, flavanols and flavonols appeared to be more active than flavones. Furthermore, treatment of Vero cells with ECG and galangin (which previously showed strong antiviral activities) before virus adsorption led to a slight enhancement of inhibition as determined by a yield reduction assay, indicating that an intracellular effect may also be involved. 相似文献
859.
The use of evoked potentials for clinical correlation and surgical outcome in cervical spondylotic myelopathy with intramedullary high signal intensity on MRI 总被引:3,自引:0,他引:3
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Lyu RK Tang LM Chen CJ Chen CM Chang HS Wu YR 《Journal of neurology, neurosurgery, and psychiatry》2004,75(2):256-261
OBJECTIVE: To investigate the use of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) for clinical significance and surgical outcome in patients with cervical spondylotic myelopathy (CSM) with intramedullary high signal intensity on T2 weighted MRI. METHODS: Forty nine patients were scored according to the modified Japanese Orthopaedic Association (JOA) score for cervical myelopathy. MEP and SEP studies were performed and the results were categorised as normal or abnormal. Thirty nine patients who had received surgical decompression were re-evaluated after 6 months. Surgical outcome was represented by the recovery ratio of the JOA score. RESULTS: Abnormal MEPs were observed in 44 patients (arm: 43; leg: 30). Abnormal SEPs were found in 32 patients: (median: 24; tibial: 23). Patients with abnormal SEPs had a worse JOA score than those with normal SEPs. Thirty nine patients received surgical treatment. Patients younger than 55 had better recovery ratios than those who were 55 or older (p = 0.005, two sample Student's t test). Patients with normal median SEPs also had better recovery ratios than those with abnormal median SEPs (p = 0.007, two sample Student's t test). Among median SEP variables, only N9-20 was significantly associated with recovery ratio (p = 0.016, stepwise linear regression), with age factor controlled (p = 0.025, stepwise linear regression). CONCLUSION: Arm MEP was the most sensitive EP test for detecting myelopathy in patients with chronic CSM. Median and tibial SEPs correlated well with the severity of myelopathy while normal median SEPs correlated with good surgical outcome. Among median SEP variables, only N9-20 correlated with surgical outcome. 相似文献
860.
Lyu LC Hsu CY Yeh CY Lee MS Huang SH Chen CL 《The American journal of clinical nutrition》2003,78(4):690-701
BACKGROUND: Gout has been a significant metabolic disorder for Chinese men in Taiwan; however, there is insufficient information on diet and lifestyle risk factors in this population. OBJECTIVE: The purpose of this case-control study was to explore potential dietary and lifestyle risk factors associated with gout in Chinese men. DESIGN: Between 1998 and 1999, we recruited and conducted face-to-face interviews with patients from outpatient clinics in Taipei who had incident gout (n = 92) and with their healthy coworkers (controls; n = 92). RESULTS: Systolic blood pressure, diastolic blood pressure, waist-to-hip ratio, waist-to-height ratio, and body mass index were significantly higher in cases than in controls. Family histories of gout and diabetes mellitus were strong risk factors for gout. Frequencies of vegetable and fruit consumption were significantly lower in cases than in controls. Logistic regression analyses showed that high alcohol intake and low intakes of fiber, folate, and vitamin C increased the risk of gout, but no association was found with purine intake. After covariates were controlled for, the adjusted odds ratios for the middle and highest tertiles of waist-to-height ratio (0.50-0.54 and >/==" BORDER="0"> 0.55, respectively) were 3.89 (95% CI: 1.32, 11.46) and 4.37 (1.18, 16.22), respectively, but no linear association was found for waist-to-hip ratio and waist circumference. CONCLUSIONS: Consumption of alcohol, but not of purine, may be a significant dietary risk factor for gout. Food sources rich in dietary fiber, folate, and vitamin C, such as fruit and vegetables, protect against gout. Waist-to-height ratio, which indicates central obesity, has a significant linear effect on gout occurrence, independent of body mass index. 相似文献