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991.
《JACC: Cardiovascular Imaging》2022,15(10):1799-1820
Although it is the tool used by most interventional cardiologists to assess the severity of coronary artery disease and guide treatment, coronary angiography has many limitations because it is a shadowgraph, depicting planar projections of the contrast-filled lumen that are often foreshortened rather than imaging the diseased vessel itself. Currently available intravascular imaging technologies include grayscale intravascular ultrasound (IVUS), optical coherence tomography (OCT) (the light analogue of IVUS), and near-infrared spectroscopy that detects lipid within the vessel wall and that has been combined with grayscale IVUS in a single catheter as the first combined imaging device. They provide tomographic or cross-sectional images of the coronary arteries that include the lumen, vessel wall, plaque burden, plaque composition and distribution, and even peri-vascular structures—information promised, but rarely provided angiographically. Extensive literature shows that these tools can be used to answer questions that occur during daily practice as well as improving patient outcomes. Is this stenosis significant? Where is the culprit lesion? What is the anatomy of an unusual or ambiguous angiographic lesion? What is the right stent size and length? What is the likelihood of distal embolization or periprocedural myocardial infarction during stent implantation? Has the intervention been optimized? Why did this stent thrombose or restenose? This review summarizes these uses of intravascular imaging as well as the outcomes data supporting their incorporation into routine clinical practice. 相似文献
992.
BACKGROUND AND OBJECTIVES: This study was carried out to determine the frequency of hepatitis B virus (HBV) core promoter variants (nucleotide positions 1762, 1764) and precore variants (nucleotide position 1896) in hepatitis B surface antigen (HBsAg)-positive Scottish blood donors. HBV genotypes present in this population were also identified. MATERIALS AND METHODS: A total of 85 HBsAg-positive blood donor samples were included in the study. Of these, 79 were polymerase chain reaction (PCR) positive and had sequence and mutation information. They were divided into two groups: group 1 (23 individuals) were hepatitis B e antigen (HBeAg)-positive and negative for antibody to HBe (anti-HBe); and group 2 (56 individuals) were HBeAg negative and positive for anti-HBe. A line probe assay was used to detect mutations, and a comparison was made by using direct sequence analysis. A different line probe assay was used to identify HBV genotype. RESULTS: The frequencies of mutations in group 1 were 22% each for mutations 1762, 1764 and 1896, increasing to 26%, 35% and 55% in group 2, respectively. By contrast, direct sequence analysis failed to identify 70% of wild-type/mutant mixes. The prevalence of viral genotypes was 41% for genotype A, 12% for genotype B, 5% for genotype C, 30% for genotype D and 12% for mixed-genotype infections. Precore mutations were seen in 10%, 88%, 25% and 74% of genotypes A, B, C and D, respectively. CONCLUSIONS: The results indicate that core promoter and/or precore mutants may be under-reported. The combination of HBV PCR and line probe assays is useful for supplementing HBV serological tests. Non-Caucasian genotypes are present in the UK blood-donating population and will therefore affect the demographics of HBV infection. 相似文献
993.
目的:评估流动性双重固化复合树脂核材料在短时超高强度照射下的聚合效果.方法:将双重固化流动性复合树脂核材料(regular dentine,Para core)注满单端开口的长方体形不透光硅橡胶模具中,将光固化灯紧贴开口端,以1000 mW/cm2持续照射10、20 s或以3200 mW/cm2持续照射3、6s.试件避光保存1h后取出,测量试件纵断面距照射光源1~10 mm间,以1 mm为间隔共10个深度的努氏显微硬度以判断聚合效果.试件继续避光保存24 h后,重复上述测量.采用SPSS 16.0软件包对数据进行统计学分析.结果:除3200 mW/cm2、3s光照射条件无法引发光固化反应外,在其余光照射条件下,试件在光影响深度内的硬度值在光照后24 h都显著高于单纯化学固化产生的硬度值,但光照射对试件的影响深度有限.在试件的光影响深度内,随着光照射时间的延长,试件的硬度值得到显著提高;而试件在3200 mW/cm2、6 s和1000 mW/em2、20 s条件下光照射后24 h的硬度值无显著差异.结论:3200 mW/cm2光强度照射时间必须延长到6s,才能保证引发流动性复合树脂核材料的光固化反应,并获得合适的聚合效果. 相似文献
994.
995.
目的探讨乙型肝炎病毒(HBV)前核心区(前C区,nt1896)及基本核心启动子(BCP,nt1762/1764)变异在慢性HBV感染者疾病谱的分布及对患者疾病谱的影响。方法416例血清HBsAg阳性、HBVDNA定量大于1.0×104拷贝/毫升的患者,采用微流基因芯片检测HBV前C区及BCP变异。结果416例HBV感染者中302例为HBeAg(-)患者,其中248例(82.12%)有前C区或BCP变异,41.06%为前C区变异,31.12%BCP变异,2种同时变异为9.94%。HBeAg(-)的慢性乙型肝炎和肝硬化患者前C区变异分别为64.72%和83.33%(x2=0.89,P>0.05),均大于HBeAg(-)无症状携带者的28.47%(x2=54.20,P<0.01;x2=5.29,P<0.05);而HBeAg(-)无症状携带者BCP变异达77.19%,大于HBeAg(-)慢性乙型肝炎和肝硬化患者(x2=69.73,P<0.01;x2=10.58,P<0.01)。而在114例HBeAg(+)患者中28.95%有前C区或BCP变异。结论前C区或BCP变异在慢性HBV感染者疾病谱的分布不同,在HBeAg(-)/HBVDNA(+)与HBeAg(+)/HBVDNA(+)患者变异率差异显著。HBV前C区可能是该病变反复及加重的一个重要原因,但BCP变异临床意义不明确。 相似文献
996.
Comparative study of genotype B and C hepatitis B virus-induced chronic hepatitis in relation to the basic core promoter and precore mutations 总被引:7,自引:0,他引:7
Watanabe K Takahashi T Takahashi S Okoshi S Ichida T Aoyagi Y 《Journal of gastroenterology and hepatology》2005,20(3):441-449
BACKGROUND: The clinicopathological profiles and outcome of chronic hepatitis B can differ by hepatitis B virus (HBV) genotypes. In Japan, genotype B and C are two major HBV genotypes. The basic core promoter and precore mutations are other known viral factors for disease activity, although the relationship between HBV genotypes and these mutations is not fully understood. METHODS: The HBV genotypes in 90 patients with chronic hepatitis B were determined using an ELISA. Obtained data were correlated with clinicopathological parameters, basic core promoter, precore and the nucleotide 1858 mutations of the HBV genome. RESULTS: Among 90 cases, 20 (22.2%) had genotype B and 70 (77.8%) had genotype C HBV. Genotype B patients were older than genotype C patients (44.0 +/- 13.9 vs 34.7 +/- 11.0 P = 0.0022). The HBeAg was more prevalent in genotype C than B patients (P = 0.0008) while anti-HBe was more common in genotype B than C patients (P = 0.0002). Serum aspartate aspartate aminotransferase/alanine aminotransferase levels (B: 220.7 +/- 612.8/257.0 +/- 498.0 IU/L vs C: 111.3 +/- 122.8/201.6 +/- 229.4 IU/L, P = 0.16/0.48) and HBV viral loads in blood (B: 6.1 +/- 3.1 log genome equivalent [LGE]/mL vs C: 6.7 +/- 2.3 LGE/mL, P = 0.42) were equivalent. The seroconversion from HBeAg to anti-HBe occurred significantly earlier in genotype B than C patients (62 +/- 53 months vs 136 +/- 54 months, P = 0.0028) during the mean observation period of 149 +/- 82 months even under various therapeutic modalities. The categories III and IV of the histological activity index in genotype C were higher (III: P < 0.005, IV: P < 0.05, n = 68) than that in B patients whereas category II was higher in genotype B than C patients (P < 0.05). The double mutation (1762T/1764A) in the basic core promoter was more frequently found in genotype C than in B HBV (P = 0.0068), whereas the precore mutation (1896A) was more common in genotype B than C HBV (P = 0.0233). The incidence of 1858C that was complementary to the precore mutation site in the stem-loop structure in, was equally rare in both genotype B and C HBV. CONCLUSIONS: Genotype B patients were older, had earlier HBeAg seroconversion and exhibited more severe lobular necroinflammation, less portal inflammation and fibrosis than genotype C patients. This genotypic difference is related to the basic core promoter and precore mutations irrespective of 1858C. (c) 2004 Blackwell Publishing Asia Pty Ltd. 相似文献
997.
Distinction in the immunoreactivities of two calcium‐binding proteins and neuronal birthdates in the first and higher‐order somatosensory thalamic nuclei of mice: Evolutionary implications
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Yuan‐Yuan Gao Chao‐Xi Xue‐Bo Zhang Xin‐Wen Zhang Shao‐Ju Zeng 《The Journal of comparative neurology》2015,523(18):2738-2751
Comparative embryonic studies are the most effective way to discern phylogenetic changes. To gain insight into the constitution and evolution of mammalian somatosensory thalamic nuclei, we first studied how calbindin (CB) and parvalbumin (PV) immunoreactivities appear during embryonic development in the first‐order relaying somatosensory nuclei, i.e., the ventral posteromedial (VPM) and posterolateral (VPL) nuclei, and their neighboring higher‐order modulatory regions, including the ventromedial or ventrolateral nucleus, posterior, and the reticular nucleus. The results indicated that cell bodies that were immunoreactive for CB were found earlier (embryonic day 12 [E12]) in the dorsal thalamus than were cells positive for PV (E14), and the adult somatosensory thalamus was characterized by complementary CB and PV distributions with PV dominance in the first‐order relaying nuclei and CB dominance in the higher‐order regions. We then labeled proliferating cells with [3H]‐thymidine from E11 to 19 and found that the onset of neurogenesis began later (E12) in the first‐order relaying nuclei than in the higher‐order regions (E11). Using double‐labeling with [3H]‐thymidine autoradiography and CB or PV immunohistochemistry, we found that CB neurons were born earlier (E11–12) than PV neurons (E12–13) in the studied areas. Thus, similar to auditory nuclei, the first and the higher‐order somatosensory nuclei exhibited significant distinctions in CB/PV immunohistochemistry and birthdates during embryonic development. These data, combined with the results of a cladistic analysis of the thalamic somatosensory nuclei, are discussed from an evolutionary perspective of sensory nuclei. J. Comp. Neurol. 523:2738–2751, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
998.
目的 研究不同类型核材料与二氧化锆陶瓷树脂间的粘接强度及耐久性。方法 二氧化锆陶瓷盘经研磨后通过2种自粘接型树脂水门汀(Clearfil SA Luting和RelyX U100)与不同核材料包括流动型复合树脂核材料、充填型复合树脂、钴铬合金以及牙本质进行粘接,组成个8实验组。每个实验组再分成2个亚组,分别接受0、10 000次冷热循环后进行剪切粘接强度测试。结果 核材料、树脂水门汀材料及老化条件均会对粘接强度产生明显影响(P<0.001)。冷热循环后,只有Clearfil SA Luting与钴铬合金的粘接强度没有明显降低(P>0.05),并高于其余各核材料组(P<0.05);Clearfil SA Luting与钴铬合金、流动型复合树脂核材料及充填型复合树脂间的粘接强度均明显高于RelyX U100相对应的粘接强度(P<0.05),而Clearfil SA Luting和RelyX U100与牙本质间的粘接强度的差异无统计学意义(P>0.05)。结论 不同类型核材料和树脂水门汀材料能够对二氧化锆陶瓷树脂粘接耐久性产生明显影响。 相似文献
999.
1000.
Martín Caserío Valea Victor Alonso de la Peña 《Journal of the American Dental Association (1939)》2017,148(2):75-80