胚胎发育基因Twist与妇科肿瘤研究

胚胎发育基因Twist属于螺旋-环-螺旋蛋白家族中高度保守的转录因子,在肿瘤发生、转移、耐药和血管形成中发挥重要作用,近年来研究发现,妇科肿瘤的发生发展与细胞Twist基因表达异常相关,提示它的激活有可能成为一种新的妇科肿瘤预后判断指标和肿瘤治疗的新靶点.     

胚胎发育基因Twist与妇科肿瘤研究

胚胎发育基因Twist属于螺旋-环-螺旋蛋白家族中高度保守的转录因子,在肿瘤发生、转移、耐药和血管形成中发挥重要作用,近年来研究发现,妇科肿瘤的发生发展与细胞Twist基因表达异常相关,提示它的激活有可能成为一种新的妇科肿瘤预后判断指标和肿瘤治疗的新靶点.     

Twist基因介导肿瘤细胞耐药的研究进展

Twist属于高度保守的碱性螺旋-环-螺旋(basichelix-loop-helix,bHLH)结构的转录因子家族,在动物和人的胚胎发育、诱导细胞迁移以及组织塑形中起重要作用.Twist基因具有癌基因特征,在多种恶性肿瘤中高表达,不仅参与肿瘤的发生、侵袭和转移,而且与肿瘤细胞产生耐药性密切相关.Twist基因可以通过抗细胞凋亡、干扰抗微管类药物、诱发上皮-间质转型、诱导产生肿瘤干细胞样特性及影响肿瘤微环境等促使肿瘤细胞耐药,因此有望成为逆转肿瘤耐药的新靶点.     

乳腺癌多药耐药细胞MCF-7/ADR中Twist的表达与EMT现象的实验研究

目的：观察乳腺癌多药耐药细胞MCF-7／ADR中Twist表达及上皮-间质转化现象．探讨其与MCF-7／ADR侵袭转移能力增强的相关性。方法：分别以RT-PCR法、链霉亲和素-生物素酶复合物（Strept avidin biotin complex，SABC）免疫组织化学方法和Western blot法检测乳腺癌细胞系MCF-7及其多药耐药株MCF-7／ADR中介导EMT发生的转录因子Twist、上皮性标记基因E-钙粘素（E—cadherin）和间质性标记基因N-钙粘素（N—cadherin）表达的改变情况。结果：亲本细胞MCF-7中E—cadherin mRNA的表达和蛋白水平的表达均为阳性，Twist和N—cadherin表达阴性；多药耐药株MCF-7／ADR中E—cadherin mRNA和蛋白表达缺失，而在亲本细胞MCF-7中不表达的Twist和N—cadherin表达阳性。结论：在多药耐药乳腺癌细胞MCF-7／ADR中．其侵袭力增强可能与Twist介导的EMT发生有关。     

棘霉素对肝癌SMMC7721细胞凋亡相关基因影响的研究

目的：探讨棘霉素诱导肝癌SMMC7721细胞的凋亡作用及对转录因子Twist、p53、Survivin和hTERT（人端粒酶）基因的影响。方法：采用MTT法测定棘霉素对肝癌细胞的生长抑制率；半定量逆转录聚合酶链反应（RT-PCR）检测与肝癌的发生和转移密切相关的转录因子Twist，与细胞增殖和凋亡联系紧密的p53、Survivin和hTERT的mRNA表达水平的改变；利用Westernblot方法分析棘霉素治疗后上述基因的蛋白表达情况。结果：体外实验证实，棘霉素浓度〉10．0ng／mL各组对细胞的生长抑制均显著增加，P〈0．05，随棘霉素药物浓度增加，细胞抑制率明显增大。棘霉素抑制肝癌细胞株SMMC7721的作用呈剂量一时间依赖性。RT-PCR方法证实，随着棘霉素剂量的增加，肝癌SMMC7721细胞株中Twist、Survivin和hTERTmRNA表达水平逐渐下调，P〈0．01，p53mRNA表达水平微弱上调，P〈0．05。Westernblot检测显示，Twist、Survivin和hTERT蛋白的表达量呈递减趋势，P〈0．01，p53蛋白的表达微弱上调，P〈0．01。结论：随着棘霉素剂量的增加，细胞凋亡率显著增加。棘霉素能够抑制与肝癌生长密切相关基因的Twist、Survivin和hTERTmRNA表达，促进p53mRNA表达上调，相应蛋白的表达呈下调和上调。棘霉素可能通过抑制肝癌细胞的生长、转移和促进肝癌细胞的凋亡起到抑制肿瘤生长的作用。     

Twist基因与肿瘤转移和耐药

Twist是碱性螺旋-环-螺旋(bHLH)转录因子家族成员,是上皮间质转化(EMT)过程中的关键调控因子.Twist在胚胎发育及肿瘤的发生发展、侵袭转移过程中发挥重要作用,并与肿瘤耐药密切相关.     

T=G+E(肿瘤发生模型)

一切事物都是由内因和外因决定的。生物的一切表现型都是遗传和环境因素相互作用的产物[1]。对于肿瘤发生这一生物学性状可以从T＝G＋E的模型进行讨论。T代表一切肿瘤；G代表肿瘤基因，它是肿瘤发生的内在因素；E表示影响肿瘤发生、发展的环境综合因素，它的影响可导致机体细胞恶变，也可使恶变细胞恢复正常化，是肿瘤发生的外因。肿瘤发生的遗传学因素──G一、肿瘤基因的整套性肿瘤的发生是一个极为复杂的过程。从机体可形成的肿瘤表现型来看：种类繁多，形式各异。但所有的肿瘤都具有一定的共性和个性，如细胞异型增生、侵润、转移及…     

AEG-1与消化系统肿瘤关系的研究进展

星形细胞上调基因1(AEG-1)是一种癌基因,研究表明它在多种肿瘤的发生发展中发挥着重要的功能。本文就AEG-1在消化系统肿瘤的细胞增殖、侵袭转移、血管生成及化疗耐药等方面的研究进展做一综述。     

上皮-间质转化及其干性作用与肿瘤

上皮-间质转化（EMT）参与肿瘤转移过程,Twist作为关键调控因子在EMT中发挥重要作用,放疗、化疗和多种细胞因子均可诱导Twist介导的EMT。研究表明,肿瘤细胞可能通过EMT转变为肿瘤干细胞样细胞,并进一步导致放化疗抵抗、肿瘤血管形成及远处转移,对肿瘤的预后产生巨大影响,EMT有望成为肿瘤治疗的重要靶点。     

转录因子Snail与肿瘤的上皮细胞间质化

肿瘤对人体的危害极大,其引起的死亡大多是因为肿瘤转移。肿瘤的转移是一个十分复杂的过程,它是多种基因参与的结果,不仅仅是遗传性状的改变,还包括细胞与细胞之间、细胞与细胞外基质之间的相互作用。一些在胚胎发育中起着重要作用的基因常常在癌组织中重新激活,提示其可能有促进肿瘤发生和/或转移的作用。肿瘤的浸润和转移是通过细胞粘附分子的改变而实现的,这些粘附分子也是许多致癌因素最终的作用位     

Ringworm in animals in a farm in Assiut

Bericht über das Auftreten von Hautmykosen bei Tieren auf der Farm der Landwirtschaftlichen Fakultät der Universität Assiut. Von 70 Kälbern waren 42 pilzkrank, davon 22 durch T. mentagrophytes, 20 durch T. verrucosum. Von 180 Kühen waren 8 pilzbefalien, sämtlich durch T. mentagrophytes. Von 2 kranken Bullen wurde T. verrucosum isoliert. Auch die 3 Pferde und 2 Maultiere der Farm waren pilzinfiziert; Erreger war in diesen Fällen T. equinum. Auch ein Kalb war von T. equinum befallen. Die gleiche Pilzart wurde ferner von 3 Tierpflegern isoliert, die Pilzherde am Hals und an den Armen aufwiesen.     

Statistical challenges in preprocessing in microarray experiments in cancer

Many clinical studies incorporate genomic experiments to investigate the potential associations between high-dimensional molecular data and clinical outcome. A critical first step in the statistical analyses of these experiments is that the molecular data are preprocessed. This article provides an overview of preprocessing methods, including summary algorithms and quality control metrics for microarrays. Some of the ramifications and effects that preprocessing methods have on the statistical results are illustrated. The discussions are centered around a microarray experiment based on lung cancer tumor samples with survival as the clinical outcome of interest. The procedures that are presented focus on the array platform used in this study. However, many of these issues are more general and are applicable to other instruments for genome-wide investigation. The discussions here will provide insight into the statistical challenges in preprocessing microarrays used in clinical studies of cancer. These challenges should not be viewed as inconsequential nuisances but rather as important issues that need to be addressed so that informed conclusions can be drawn.     

Trends in zygomycosis in children

Zygomycosis, or mucormycosis, is associated with significant morbidity and mortality in both children and adults. Studies in adults have shown an increase in the incidence of zygomycosis, particularly among haemtopoietic stem cell transplant (HSCT) recipients and patients with haematologic malignancies. There is a paucity of data on the epidemiology of zygomycosis in children. We performed a retrospective analysis to describe trends in zygomycosis between 1 January 2003 and 31 December 2010. We used the Pediatric Health Information System (PHIS) database to identify paediatric patients who were diagnosed with zygomycosis during the study period. Administrative data on diagnoses, demographics, underlying conditions and clinical experiences were collected. Summary statistics were calculated and tests for trend were conducted. We identified 156 unique patients with zygomycosis. The prevalence of zygomycosis did not significantly increase over time (P=0.284). The most common underlying condition was malignancy (58%) and over half received intensive care. Voriconazole utilisation among all hospitalised children significantly increased during the period (P=0.010). Our study demonstrates that the incidence of zygomycosis is not significantly increasing. During the time period there was a significant increase in the use of voriconazole among children.     

Hemoglobin in lymphogranulomatosis in children

The peculiarities of hemoglobin content and properties in lymphogranulomatosis were studied in children by different methods. In most patients the content of fetal hemoglobin and methhemoglobin was found to increase and the rate of ferricyanide oxidation of hemoglobin also increases. Simultaneously, the rate of non-homogenicity of basic hemoglobin fractions was observed to increase on account of immunologically different components.     

Dermatomycosis in Goats in India

Summary: In an extensive survey involving 2176 goats 1.56% of goats manifested clinical lesions of ringworm infection. Animals below the age of 6 months were affected most (4.20%). The incidence of infection was higher during the winter months. T. verrucosum, T. mentagrophytes and M. gypseum were isolated from the skin scrapings of 12, 4, and 2 goats respectively. It is suggested that the infected animals could be a source of disease to human population in which the zoophilic dermatophyte invasion is characterized by severe inflammatory lesions of the skin. The zoonotic importance of different dermatophytes is stressed.
Zusammenfassung: In einer ausgedehnten Untersuchung an 2176 Ziegen wurden bei 1,56% klinische Zeichen einer Hautmykose festgestellt. Tiere, die jühger als 6 Monate alt waren, zeigten mit 4,20% am häfigsten Krankheitssymptome. In den Wintermonaten war die Erkrankungshäufigkeit am gröBten. T. vermcosum, T. mentagrophytes and M. gypseum wurden jeweils von 12,4 bzw. 2 Ziegen isoliert. Die inflzierten Tiere köinnen eine Infektionsquelle für die menschliche Bevölkerung darstellen und dort Mykosen mit stark entzündlichen Veränderungen auslösen. Die Bedeutung verschiedener Dermatophyten als Erreger von Zoonosen wird hervorgehoben.     

Sex hormones in women in rural China and in Britain

Plasma concentrations of certain hormones linked to breast cancer risk were measured in age-pooled samples from 3,250 rural Chinese women in 65 counties, and 300 British women, all aged 35-64. In age-groups 35-44, 45-54 and 55-64 respectively, mean oestradiol concentrations were 36% (P = 0.043), 90% (P less than 0.001) and 171% (P = 0.001) higher in the British than in the Chinese women, and mean testosterone concentrations were 48% (P less than 0.001), 68% (P less than 0.001) and 53% (P = 0.001) higher in the British than in the Chinese women. The difference in testosterone concentrations between the two countries appeared to be due largely to the lower average body weight in the Chinese women. Sex hormone binding globulin did not differ significantly between the two countries in age groups 35-44 and 45-54, but was 15% (P = 0.002) lower in the British than in the Chinese women at ages 55-64. Prolactin concentrations did not differ significantly between the two countries in any age group.     

Temozolomide treatment in glioma--experiences in two university hospitals in Finland

Thirty-two patients with relapsing glioma were treated with temozolomide in two university hospitals in Finland. One patient (3%) had complete response and 9 (28%) partial response, with 8 patients (25%) showing stable disease. Median progression-free survival for these 18 patients (56%) was 7 months (range 2-11+). The remaining either had progressive disease (25%) or only clinical evaluation (19%). Karnofsky score improved in 34% of patients and decreased in 3%. Symptoms were alleviated in 44% and deteriorated in 9%. Grade 3-4 toxicity was detected in 9% of the patients. Only 4% of the days in treatment were spent in hospital. An average 1.8 neuroradiological investigations, 6.9 laboratory visits, and 5.3 visits to the oncologist were made. This study confirms that temozolomide has positive effects on the outcome of often heavily pretreated glioma patients. High drug costs are compensated by prolonged home care and even the possibility to maintain working capacity.