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991.
Chen Yang Hou Xuewen Yang Yifeng Ge Qianqian Zhou Yan Nie Shengdong 《Journal of digital imaging》2023,36(2):688-699
Journal of Digital Imaging - Lung cancer manifests as pulmonary nodules in the early stage. Thus, the early and accurate detection of these nodules is crucial for improving the survival rate of... 相似文献
992.
Zahid Hussain Saima Rani Fanshu Ma Wenjing Li Wenqi Shen Tian Gao Jine Wang Renjun Pei 《Reviews in medical virology》2023,33(2):e2425
Dengue illness can range from mild illness to life-threatening haemorrhage. It is an Aedes-borne infectious disease caused by the dengue virus, which has four serotypes. Each serotype acts as an independent infectious agent. The antibodies against one serotype confer homotypic immunity but temporary protection against heterotypic infection. Dengue has become a growing health concern for up to one third of the world's population. Currently, there is no potent anti-dengue medicine, and treatment for severe dengue relies on intravenous fluid management and pain medications. The burden of dengue dramatically increases despite advances in vector control measures. These factors underscore the need for a vaccine. Various dengue vaccine strategies have been demonstrated, that is, live attenuated vaccine, inactivated vaccine, DNA vaccine, subunit vaccine, and viral-vector vaccines, some of which are at the stage of clinical testing. Unfortunately, the forefront candidate vaccine is less than satisfactory, and its performance depends on serostatus and age factors. The lessons from clinical studies depicted ambiguity concerning the efficacy of dengue vaccine. Our study highlighted that viral structural heterogeneity, epitope accessibility, autoimmune complications, genetic variants, genetic diversities, antigen competition, virulence variation, host-pathogen specific interaction, antibody-dependent enhancement, cross-reactive immunity among Flaviviruses, and host-susceptibility determinants not only influence infection outcomes but also hampered successful vaccine development. This review integrates dengue determinants allocated necessities and challenges, which would provide insight for universal dengue vaccine development. 相似文献
993.
鼻咽癌放疗后局部复发和纤维化的增强CT鉴别诊断价值 总被引:16,自引:0,他引:16
目的探讨鼻咽癌放疗后出现块影时,CT检查对鉴别肿瘤局部复发和放射性纤维化的价值。方法收集159例经CT检查的鼻咽癌,其中放疗后局部复发(RT)37例,放射性纤维化(RF)54例,以68例未经放疗的鼻咽癌(PT)作对比。使用ELScintsprint2000型CT机,测量放疗后出现的块影平扫和强化的CT值,用统计学的方差分析法处理增强前后的CT值差异。结果RT组平扫CT值为50.40±8.10Hu,增强为73.74±7.37Hu;RF组平扫为48.62±10.15Hu,增强为56.74±8.69Hu;对照组(PT)病变区平扫为48.32±9.20Hu,增强为72.38±7.75Hu。测量表明RT组有明显强化,RT组与RF组强化后CT值差异有非常显著性(P<0.01)。结论鼻咽癌放疗后出现块影时,CT增强扫描可作为鉴别诊断的重要方法。 相似文献
994.
农村饮水水质现状分析 总被引:9,自引:0,他引:9
在全国26个省、市、自治区的180个县进行农村饮水卫生监测,监测区总人口为8939万人。其中以地下水为饮用水源的占69.6%,集中式供水的人口占47.1%。按照《农村实施〈生活饮用水卫生标准〉准则》进行分级,饮用不合格水的人口占42.7%。12项监测指标中,微生物指标超标严重,总大肠菌群超过3个/L的供水人口占51.8%;细菌总数超过1×105个/L(100个/ml)的供水人口占39.1%。有机污染普遍存在,饮水耗氧量超过3mg/L的供水人口占21.5%。部分地区氟化物含量过高,天津市所辖农村饮用氟化物大于1.0mg/L水的人口比例超过70%。 相似文献
995.
Ping Gao Yinglin Lu Xueming Ge Wenhong Fan Shengfa Fu Shuang Liu Heping Yang 《中国癌症研究》1997,9(3):192-194
In order to investigate TGFβ1 gene expression and its effect on murine tumor growth following direct intratumoral injection
of naked plasmid DNA encoding human TGFβ1, LM3 murine lung adenocarcinoma cells were inoculated subcutaneously to T739 mice and grew to tumor nodules in 2 weeks. Multiple direct intratumoral injection of plasmid DNA, PMAMneo- TGFβ1, were given
and compared with saline or vector plasmid administration groups. The growth of tumor was observed till the 8th week when
the mice were killed for Northern blot analysis and histopathological study of tumoral tissue. The results showed that the
growth of tumor was boosted in the TGFβ1 gene treated mice as compared with the control groups, whereas there was no significant
difference in the metastatic behavior. Northern blot showed efficient expression of TGFβ1 mRNA in the treated group. The present
study indicated that TGFβ1 may stimulate tumor growthin vivo through certain mechanisms. And direct intra-tumoral injection of nude plasmid DNA may be a promising gene transfer strategyin vivo.
This work was supported by the National Natural Science Foundation of China (No. 39370761). 相似文献
996.
用51只Wistar大鼠建立了新的大鼠原位肝移植手术模型,手术成功率为92.1%,周存活率为86.27%。手术要点是术前供肝冷灌注;受体肝只建立门静脉血供,静脉吻合分别采用“双袖套”式吻合和“8”字外翻缝合;胆管重建采用单管支架总胆管对端吻合法。移植术后肝细胞超微结构动态观察表明:术后2周是控制免疫排斥反应的关键时期,术后8周实验鼠产生免疫耐受性,移植肝脏成活。 相似文献
997.
Tao Van Tran Carlos Auer Yan Guex-Crosier Nancy Pittet Carl P. Herbort 《International ophthalmology》1994,18(5):293-298
Since January 1990, data from uveitis patients have been systematically stored in a computer data bank. During the period from January 1990 to March 1993, 435 new patients (185 female and 250 male, mean age 43 years; range 6–92) were seen at the Uveitis Clinic of the Hopital Jules Gonin. These 435 patients (630 eyes) were subdivided into anterior uveitis (268 patients — 62%), intermediate uveitis (47 patients — 11%), posterior uveitis (89 patients — 20%) and panuveitis (31 patients — 7%). The incidence of uveitis for the referral area considered was calculated to be 17 per 100,000 inhabitants per year. A specifie diagnosis was found in 312 cases (72%). The most frequently diagnosed entities were HLA-B27-associated acute anterior uveitis (67 cases — 15.4%), uveitis associated with acute herpes zoster ophthalmicus (40 cases — 9.2%), toxoplasmosis (39 cases — 9%), typical pars planitis (29 cases — 6.7%), sarcoidosis (29 cases — 6.7%), Fuchs' heterochromic cyclitis (27 cases — 6.2%), herpetic anterior uveitis (21 cases — 4.8%) and acute retinal necrosis (11 cases — 2.5%). Incidence and distribution of most disease entities correspond to those of other European series. 相似文献
998.
Kenneth V. Honn Dean G. Tang Xiang Gao Igor A. Butovich Bin Liu Jozsef Timar Wolfgang Hagmann 《Cancer metastasis reviews》1994,13(3-4):365-396
Arachidonic acid metabolites have been implicated in multiple steps of carcinogenesis. Their role in tumor cell metastasis, the ultimate challenge for the treatment of cancer patients, are however not well-documented. Arachidonic acid is primarily metabolized through three pathways, i.e., cyclooxygenase, lipoxygenase, and P450-dependent monooxygenase. In this review we focus our attention on one specific lipoxygenase, i.e., 12-lipoxygenase, and its potential role in modulating the metastatic process. In mammalian cells there exist three types of 12-lipoxygenases which differ in tissue distribution, preferential substrates, and profile of their metabolites. Most of these 12-lipoxygenases have been cloned and sequenced, and the molecular and biochemical determinants responsible for catalysis of specific substrates characterized. Solid tumor cells express 12-lipoxygenase mRNA, possess 12-lipoxygenase protein, and biosynthesize 12(S)-HETE [12(S)-hydroxyeicosatetraenoic acid], as revealed by numerous experimental approaches. The ability of tumor cells to generate 12(S)-HETE is positively correlated to their metastatic potential. A large collection of experimental data suggest that 12(S)-HETE is a crucial intracellular signaling molecule that activates protein kinase C and mediates the biological functions of many growth factors and cytokines such as bFGF, PDGF, EGF, and AMF. 12(S)-HETE plays a pivotal role in multiple steps of the metastatic cascade encompassing tumor cell-vasculature interactions, tumor cell motility, proteolysis, invasion, and angiogenesis. The fact that 12-lipoxygenase is expressed in a wide diversity of tumor cell lines and 12(S)-HETE is a key modulatory molecule in metastasis provides the rationale for targeting these molecules in anti-cancer and anti-metastasis therapeutic protocols. 相似文献
999.
H. Suga I. Uyeda J. Yan K. Murao I. Kimura E. R. Tiongco P. Cabautan H. Koganezawa 《Archives of virology》1995,140(8):1503-1509
Summary Genomic heterogeneity of genome segment 9 (S9) of rice ragged stunt virus (RRSV) was investigated and a point mutation was found to be responsible for an electrophoretic mobility shift of S9 on polyacrylamide gel electrophoresis (PAGE). A new form of S9 (S9L) which migrated slightly faster than natural S9 (S9U) had the same length with AC transversion at nt 843. Synthetic S9 with a C:G pair at nt 843 migrated slightly faster than that with an A:U pair. Therefore, we conclude that the single point mutation shifts the electrophoretic mobility. Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), we could detect S9U and S9L alone or mixture in insect vectors after acquisition as well as in infected rice plants. 相似文献
1000.
Crystals of the C2-acetate analog of paclitaxel, grown from a mixture of isopropyl alcohol and methanol, belong to the space group P2l with a = 9.058(3), b = 18.306(5), c = 15.043(1) , = 97.09(1)°, Z = 2, V = 2475.1(9)3, D
calc = 1.269 gcm–3 and µ = 0.75 cm–1. The structure was determined by direct methods and refined to R(F) = 0.054 and wR(F) = 0.057 for 605 variables and 3496 observed reflections. The paclitaxel side chain possesses a conformation similar to that observed in the crystal structure of docetaxel (Taxotere®). A three dimensional network of hydrogen bonds is formed through solvent molecules and stabilizes the crystal lattice. 相似文献