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941.
Viral myocarditis is an important potential precursor to idiopathic dilated cardiomyopathy. An understanding of its pathogenesis has evolved with the recent clarification of the role of immune mechanisms, which appears to have both protective and autodestructive effects. In animal models immune modulation has led to paradoxical worsening of the disease, and clinical trials of immunosuppression have not shown any beneficial effects. Through the use of molecular diagnostic techniques, a possible direct role for the virus itself is now increasingly recognized in human disease. This is supported by animal models demonstrating viral cytopathic effects and chronic persistence of virus within the myocardium. A novel contribution from microvascular ischemia has also recently been demonstrated; this may play a particularly important role in the evaluation and treatment of dilated cardiomyopathy. These changing concepts in pathogenesis will have an impact on diagnosis; myocardial biopsy will be used for molecular diagnosis of viral infection, in addition to providing important histological information. Therapy for viral myocarditis will also evolve in parallel to include trials of antiviral agents, targeted immune modulators, and anti-ischemic or vasodilator therapy. With new tools of molecular diagnosis in myocarditis complementing the traditional morphological and immunological assessments, we now have avenues of opportunity to explore in depth the pathogenesis, epidemiology, and prognosis of this challenging disease. 相似文献
942.
为了寻找和研究新的人类基因cDNA,本实验以T7DNA聚合酶对一DXFD52相关人肝细胞cDNA(DE)进行了分段部分测定,并将所测各部分序列分别在EMBL(欧洲分子生物学库)中进行核酸同源性检索,结果在库中没有找到任何具有同源性的人类基因或DNA片段。因此,我们初步认为DE为一新的人类基因cDNA片段。同时为初步探讨DE的功能,我们还成功地将DE构建于反转录病毒载体PLXSN上。 相似文献
943.
944.
Chen T Hutts RC Mei N Liu X Bishop ME Shelton S Manjanatha MG Aidoo A 《Environmental and molecular mutagenesis》2005,45(5):409-418
A growing number of studies suggest that isoflavones found in soybeans have estrogenic activity and may safely alleviate the symptoms of menopause. One of these isoflavones, genistein, is commonly used by postmenopausal women as an alternative to hormone replacement therapy. Although sex hormones have been implicated as an important risk factor for the development of hepatocellular carcinoma, there are limited data on the potential effects of the estrogens, including phytoestrogens, on chemical mutagenesis in liver. Because of the association between mutation induction and the carcinogenesis process, we investigated whether endogenous estrogen and supplemental genistein affect 7,12-dimethylbenz[a]anthracene (DMBA)-induced mutagenesis in rat liver. Intact and ovariectomized female Big Blue rats were treated with 80 mg DMBA/kg body weight. Some of the rats also received a supplement of 1,000 ppm genistein. Sixteen weeks after the carcinogen treatment, the rats were sacrificed, their livers were removed, and mutant frequencies (MFs) and types of mutations were determined in the liver cII gene. DMBA significantly increased the MFs in liver for both the intact and ovariectomized rats. While there was no significant difference in MF between the ovariectomized and intact control animals, the mutation induction by DMBA in the ovariectomized groups was significantly higher than that in the intact groups. Dietary genistein did not alter these responses. Molecular analysis of the mutants showed that DMBA induced chemical-specific types of mutations in the liver cII gene. These results suggest that endogenous ovarian hormones have an inhibitory effect on liver mutagenesis by DMBA, whereas dietary genistein does not modulate spontaneous or DMBA-induced mutagenesis in either intact or ovariectomized rats. 相似文献
945.
本文通过对17483例甲状腺肿大中五种甲状腺病病例的收集、分析、整理、统计与提炼,确定了诊断原则,建立了知识库、病例库和正反双向混合推理机制,完成了用Turbo-Prolog语言编制。采用适用于表示医学产生式知识表示方法所开发的专家诊断与咨询系统,为教学、临床工作及家庭保健提供了有价值的软件。经临床病例验证,该软件准确、可靠、有很强的实用价值,对人工智能的研究、临床及教学的现代化,提高人们的保健水 相似文献
946.
计算机嗓音测试参数的特点及临床意义 总被引:5,自引:0,他引:5
电子计算机嗓音测试及频谱分析已成为嗓音客观检查的重要手段。其测试参数为喉部疾病诊断、疗效评价的主要指标。但嗓音的声学参数是一种多维函数,与声带振动的生物力学密切相关。为了更好的理解和掌握嗓音的声学参数,对嗓音测试的参数进行详细的分析。以便于准确地选用和科学、客观地评价嗓音。 相似文献
947.
利用旋转壁式生物反应器(Rotating wall vessel,RWV)体外培养脐带血干细胞,使其大量扩增,以满足临床应用对造血干/祖细胞的数量与质量要求。从脐带血分离得到的单个核细胞(Mononuclear cells,MNC)在T-flask中培养24h,之后接种到RWV反应器中,培养200h。每24h细胞计数,测量培养基的pH和渗透压变化;在144h和197h测CD34 细胞含量并做CFU-GM半固体培养。有核细胞(Nucleated cells,NC)与CD34 细胞在第197h,分别扩增了435.5±87.6倍和32.7±15.6倍,CFU-GM(Colony-forming unit-granulocyte/macrophage)细胞扩增了21.7±4.9倍。整个培养过程中,RWV反应器中的pH和渗透压都保持在造血细胞最佳的扩增条件内,pH基本保持在7.2~7.4之间,渗透压基本保持在290~310mmol/kg之间。由于旋转壁式生物反应器(RWV)结构上的特殊性,可以保证细胞在悬浮流动的状态下生长,很好地模拟了脐带中的造血微环境,使脐带血造血干细胞在该反应器中短期内得到大量扩增。 相似文献
948.
获得性免疫缺陷综合征(AIDS)合并播散性弓形虫病尸检的病理学研究 总被引:3,自引:0,他引:3
报道美国纽约地区9例播散性弓形虫病尸检材料,均有脑部病变,8例累及心脏,4例累及肺脏,尚见胰腺、消化道、甲状腺、淋巴结、泌尿生殖器官等受累。其中弓形虫性脑炎9例,心肌炎4例,肺炎3例,胰腺炎2例。仅脑炎、肺炎产牛症状,经脑CT扫描、弓形虫抗体测定提示本病,并经涂片、骨髓活检和尸检证实,以查见弓形虫为依据。临床以神经精神症状和肺部感染症状为主。病变分为静止(潜伏)、组织坏死、炎症反应及增生修复四种状态,强调囊型弓形虫形态学识别的诊断意义。 相似文献
949.
Anterograde and retrograde trafficking of brain-derived neurotrophic factor (BDNF) was examined in streptozotocin-diabetic and galactose-fed rats by measuring accumulation of endogenous neurotrophin proximal and distal to two constricting sciatic nerve ligatures and by direct injection of radiolabeled neurotrophin into the sciatic nerve. Compared to controls, accumulation of endogenous BDNF proximal and distal to the ligatures as well as basal levels in non-ligated nerve segments were decreased in streptozotocin-diabetic and galactose-fed rats. Neither streptozotocin diabetes nor galactose intoxication affected the amount of 125I-labeled BDNF retrogradely transported to the DRG after injection into the sciatic nerve. These results suggest that reduced anterograde and retrograde accumulations of BDNF in experimental diabetes are not a result of impaired capacity for receptor-mediated transport. 相似文献
950.
Intracytoplasmic sperm injection in the mouse 总被引:9,自引:0,他引:9
Ron-El R.; Liu J.; Nagy Z.; Joris H.; Van den Abbeel E.; Van Steirteghem A. 《Human reproduction (Oxford, England)》1995,10(11):2831-2834
Intracytoplasmic sperm injection (ICSI) into mouse oocytes involvesa very low survival rate. This study was designed to determinewhy ICSI frequently fails in mice. Metaphase II oocytes wereobtained from superovulated 46 week old F1 hybrid mice.Spermatozoa were retrieved from the epididymis of 1214week old F1 hybrid mice. The spiked microinjection pipette usedto inject a spermatozoon into the ooplasm had outer and innerdiameters of 10 and 8 µm respectively. The oocytes usedin the first part of the study were not activated (group 1).Some oocytes were incubated with calcium ionophore for 5 min(group 2). The injected oocytes were evaluated 6, 20, 48 and72 h after injection. A total of 143 eggs in each group underwentICSI. In group 1, sperm heads escaped into the perivitellinespace. In all, 63 (47%) of the remaining oocytes were damagedduring the injection or had degenerated by the first evaluation.The survival rate was 53%, but fertilization did not occur.In group 2, 31 oocytes (22%) were damaged during microinjectionor soon degenerated. Two oocytes underwent accidental subzonalinsemination. Six oocytes were fertilized (4.2%) among the 78%of survivors. After injection, the sperm tail was found in thecytoplasm (27 and 31% in groups 1 and 2 respectively), the perivitellinespace (45% in both groups) or protruding through the zona pellucida(28 and 23% respectively). More oocytes degenerated when thetail remained in the cytoplasm, i.e. 78% in group 1 and 36%in group 2. 相似文献