线粒体DNA突变相关疾病的基因治疗

mtDNA是动物细胞染色体外唯一存在的遗传物质,mtDNA突变相关疾病正越来越为人们所认识,但目前尚无有效的治疗手段。应用亲脂质阳离子,构建靶向线粒体PNA,转线粒体移植手段。以及构建mtDNA样质粒,都可能是今后的研究方向。     

女孩性早熟患者中检出一种新的雌激素受体基因突变

对收集的16例未见血液雌激素水平升高的临床女孩性早熟患者的外周血样本,利用PCR-SSCP方法筛查了雌激素受体基因编码区的可能突变。结果在1例患者发现：其雌激素受体基因8号外显子编码精氨酸的548位密码子,1个C→T转换导致精氨酸残基被半胱氨酸所替代;这一突变使DNA序列中产生1个BtsⅠ酶切位点,通过PCR-RFLP实验证明此患者为Arg548/Cys548杂合体。为证明该突变在性早熟发生中的作用,构建了一个雌激素受体反应元件报道质粒pGL3-promoter-ERE;成功将野生型ESR1基因定点突变,并克隆于PCR3.1真核表达质粒。报道质粒和表达质粒共转染CMF-7细胞,Cys548突变能够增加萤火虫荧光素酶的产生。结果证明该突变雌激素受体在体外具有高活性特征,因而推测在体内也可能具有相应的过高活性,从而导致女孩的性早熟。     

女孩性早熟患者中检出一种新的雌激素受体基因突变

对收集的16例未见血液雌激素水平升高的临床女孩性早熟患者的外周血样本,利用PCR—SSCP方法筛查了雌激素受体基因编码区的可能突变。结果在1例患者发现：其雌激素受体基因8号外显子编码精氨酸的548位密码子,1个C—T转换导致精氨酸残基被半胱氨酸所替代;这一突变使DNA序列中产生1个BtsⅠ酶切位点,通过PCR—RFLP实验证明此患者为Arg548／Cys548杂合体。为证明该突变在性早熟发生中的作用,构建了一个雌激素受体反应元件报道质粒pGL3-promoter—ERE;成功将野生型ESR1基因定点突变,并克隆于PCR3．1真核表达质粒。报道质粒和表达质粒共转染CMF-7细胞,Cys548突变能够增加萤火虫荧光素酶的产生。结果证明该突变雌激素受体在体外具有高活性特征,因而推测在体内也可能具有相应的过高活性,从而导致女孩的性早熟。     

Risks and Benefits of Early Antithrombotic Therapy after Thrombolytic Treatment in Patients with Acute Stroke

Background

Current guidelines recommend withholding antithrombotic therapy (ATT) for at least 24 h in patients with acute ischemic stroke treated with thrombolytic therapy. Herein, we report a retrospective analysis of a single-centre experience on the safety and efficacy of antithrombotic therapy (ATT) started before or after 24 h of intravenous thrombolysis in a cohort of acute ischemic stroke patients.

Methods

A total of 139 patients (Rapid ATT group) received antithrombotic therapy before 24 h of thrombolysis, and 33 patients (Standard ATT group) after 24 h. The brain parenchyma and vessel status were assessed using simple CT scan on admission, multimodal CT scan at the end of thrombolysis, and angio-CT/MRI scan at day 3. Functional outcome was scored using the modified Rankin Scale (mRS) at day 90.

Results

The two ATT groups had similar demographics, stroke subtypes, baseline NIHSS, thrombolytic strategies, vessel-patency rates at the end of thrombolysis, and incidence of bleeding complications at follow up. At day 3, the Rapid ATT group had a non-significant improved vessel-patency rate than the Standard ATT group. At day 90, a greater proportion of patients in the rapid ATT group had shifted down the mRS, and had improved in the NIHSS score.

Conclusions

ATT initiated before 24 h of intravenous thrombolytic therapy in acute stroke patients disclosed no safety concerns compared with a conventional antithrombotic therapy delay of 24 h and showed better functional outcome at follow up. The value of early initiation of ATT after thrombolysis deserves further assessment in randomized controlled trials.     

The Ocular Benefits of Estrogen Replacement Therapy: A Population-Based Study in Postmenopausal Korean Women

Purpose

To elucidate the prevalence of cataract, glaucoma, pterygia, and diabetic retinopathy among Korean postmenopausal women with or without estrogen replacement therapy (ERT).

Methods

A cross-sectional, nationally representative sample from the 4th Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007–2009) was used. Participants were interviewed for the determination of socioeconomic and gynecologic factors. Each woman also underwent an ophthalmologic examination and provided a blood sample for risk factor assessment.

Results

Of 3968 postmenopausal women enrolled, 3390 had never received estrogen, and 578 were undergoing estrogen treatment. After adjusting for age, diabetes, hypertension, high cholesterol levels, and high low-density lipoprotein levels, the prevalence of anterior polar cataract, retinal nerve fiber layer (RNFL) defect, and flesh pterygium was higher in the non-ERT group (OR, 3.24; 95% CI, 1.12–9.35, OR 1.70; 95% CI, 1.04–2.78, OR 3.725; 95% CI, 1.21–11.45, respectively). Further, the prevalence of atrophic pterygium was lower in the non-ERT group compared to that in the ERT group (OR, 0.21, 95% CI, 0.07–0.63).

Conclusions

These data suggest that ERT has a protective effect against the development of anterior polar cataract, flesh pterygium, and RNFL defect.     

Clinical Experience with U500 Insulin: Risks and Benefits

ObjectiveTo describe our clinical experience with U500 insulin in insulin-resistant patients, including change in glucose control, body weight, insulin dose, and hypoglycemic episodes.MethodsIn September 2010, we undertook a retrospective chart review of patients who had U500 insulin in their medication list in the preceding 2 years who were treated in the endocrinology section at Dartmouth Hitchcock Medical Center. Glycosylated hemoglobin (A1C), body weight, and insulin dosage were documented before U500 insulin introduction, after 6 months of U500 insulin use, and at the last clinic visit when the patient was still taking U500 insulin. Hypoglycemic episodes and number of daily injections were recorded.ResultsRecords of 53 patients were analyzed, one of the largest reports of U500 insulin use published to date. The mean A1C level decreased from 10.1% before U500 insulin was initiated to 9.1% after 6 months of U500 use to 8.6% at the last follow-up visit (mean follow-up was 36.6 ± 24 months). At the last charted visit, body weight increased by a mean of 6.8 kg and insulin dosage increased by a mean of 0.44 units/kg. We observed a significant increase in the number of nonsevere hypoglycemic episodes and a decrease in the number of daily injections.ConclusionPatients with uncontrolled, severely insulin-resistant diabetes can be satisfactorily treated with U500 insulin with the potential to improve glycemic control. An increase in body weight, insulin dosage, and the number of nonsevere hypoglycemic episodes was observed. (Endocr Pract. 2012;18:56-61)     

Segregating Sites in a Gene Conversion Model with Mutation

Formulae for the expectation and variance of the number of segregating and homogeneous sites in a sample of two chromosomes are found. The model includes gene conversion and infinitely-many-alleles mutation in a coalescent framework. The corresponding infinitely-many-sites model limits are also found. The formulae for the expectation are extended to any sample size. Comparisons are drawn between the pure mutation model and the model where gene conversion has been added.     

猪雌激素受体基因（ESR）点突变的PCR－SSCP检测

雌激素受体基因(ESR)是控制猪高产仔数的主效基因之一,具有明显的基因效应:BB型比AA型母猪胎总产仔数和产活仔数分别高出1.40～3.37和0.63～3.58头,是目前商品猪育种和生产中重点检测的主要基因之一。常规采用PCR－RFLPs方法区分该基因由点突变造成的3种不同的基因型。本研究建立1种基于PCR的SSCP(single－stranded conformation polymorphism)方法对猪ESR该位置的点突变进行检测,具有操作简便、灵敏度高和不需要酶切等优点,可以在育种实践中广泛应用。 Abstract:ESR is a major gene controlling litter size in swine.The sows of BB genotype produce 1.40～3.37 more piglets of the total number born and 1.07～2.40 piglets of the number born alive respectively comparing with those of AA genotype.ESR has been one of the widely detected genes in pig breeding and production.Usually the point mutation of ESR gene was detected by PCR-RFLP approach.The present study established a novel method based on PCR-SSCP,with the advantage of easy maniputation,high sensitivity and no necessity for restriction enzyme digestion.This method may be applied for commercial detection of the point mutation of ESR gene in swine breeding.     

肺癌的表皮生长因子受体分子靶向治疗与基因突变

肺癌分子靶向治疗近年来取得较大进展,特别是针对表皮生长因子受体（EGFR）分子靶向药物表现出确定的临床效果。临床应用表明,EGFR基因酪氨酸激酶域体细胞突变与非小细胞肺癌患者对酪氨酸激酶抑制剂吉非替尼的敏感性相关,本文就相关的研究进行了简述。     

Successful Estrogen Therapy for Post-Adrenalectomy Relapses of Breast Cancer

Four postmenopausal women are described in whom breast cancer responded both to bilateral adrenalectomy and bilateral oophorectomy, and subsequently, after relapse, to estrogen therapy. This paradoxical finding demonstrates the complexity of the response of breast carcinoma to hormone manipulations. Simple estrogen dependence and estrogen suppression of pituitary mammotrophins are seen to be inadequate explanations of this phenomenon. Seven fundamental observations are listed that have to be accounted for by hypotheses concerning the endocrinology of breast cancer. It is suggested that in the past we have perhaps overlooked (1) the difficulty of extrapolating observations on experimental animal tumours to spontaneous human neoplasms, (2) the fact that there may be more than one type of breast cancer, and (3) the important role that must be played by the different tissues bearing the metastases.     

The Association of Factor V Leiden and Prothrombin Gene Mutation and Placenta-Mediated Pregnancy Complications: A Systematic Review and Meta-analysis of Prospective Cohort Studies

Background

Factor V Leiden (FVL) and prothrombin gene mutation (PGM) are common inherited thrombophilias. Retrospective studies variably suggest a link between maternal FVL/PGM and placenta-mediated pregnancy complications including pregnancy loss, small for gestational age, pre-eclampsia and placental abruption. Prospective cohort studies provide a superior methodologic design but require larger sample sizes to detect important effects. We undertook a systematic review and a meta-analysis of prospective cohort studies to estimate the association of maternal FVL or PGM carrier status and placenta-mediated pregnancy complications.

Methods and Findings

A comprehensive search strategy was run in Medline and Embase. Inclusion criteria were: (1) prospective cohort design; (2) clearly defined outcomes including one of the following: pregnancy loss, small for gestational age, pre-eclampsia or placental abruption; (3) maternal FVL or PGM carrier status; (4) sufficient data for calculation of odds ratios (ORs). We identified 322 titles, reviewed 30 articles for inclusion and exclusion criteria, and included ten studies in the meta-analysis. The odds of pregnancy loss in women with FVL (absolute risk 4.2%) was 52% higher (OR = 1.52, 95% confidence interval [CI] 1.06–2.19) as compared with women without FVL (absolute risk 3.2%). There was no significant association between FVL and pre-eclampsia (OR = 1.23, 95% CI 0.89–1.70) or between FVL and SGA (OR = 1.0, 95% CI 0.80–1.25). PGM was not associated with pre-eclampsia (OR = 1.25, 95% CI 0.79–1.99) or SGA (OR 1.25, 95% CI 0.92–1.70).

Conclusions

Women with FVL appear to be at a small absolute increased risk of late pregnancy loss. Women with FVL and PGM appear not to be at increased risk of pre-eclampsia or birth of SGA infants. Please see later in the article for the Editors'' Summary     

重组腺相关病毒：很有潜力的基因治疗载体

腺相关病毒(AAV)是细小病毒家族的一员,为无包膜的线性单链DNA病毒.由于AAV具有长期潜伏于人体而不具有任何明显致病性等优点,人们对AAV作为一种理想的基因治疗载体给予了很大期望.但是,近来发现,这类载体在应用上有许多明显的缺陷,包括某些细胞膜上病毒受体数量极少,重组AAV载体位点特异性整合不足,AAV衣壳成分和转基因产物引起宿主的免疫反应等等.这些缺陷促使人们加大对AAV生物学特性和转染过程的研究,从而更好地对AAV载体进行改进,使新一代重组AAV载体具备基因治疗所必需的安全性、高效性和靶向性,以期更广泛地应用于临床.     

Towards a Molecular Taxonomy for Protists: Benefits,Risks, and Applications in Plankton Ecology

The increasing use of genetic information for the development of methods to study the diversity, distributions, and activities of protists in nature has spawned a new generation of powerful tools. For ecologists, one lure of these approaches lies in the potential for DNA sequences to provide the only immediately obvious means of normalizing the diverse criteria that presently exist for identifying and counting protists. A single, molecular taxonomy would allow studies of diversity across a broad range of species, as well as the detection and quantification of particular species of interest within complex, natural assemblages; goals that are not feasible using traditional methods. However, these advantages are not without their potential pitfalls and problems. Conflicts involving the species concept, disagreements over the true (physiological/ecological) meaning of genetic diversity, and a perceived threat by some that sequence information will displace knowledge regarding the morphologies, functions and physiologies of protistan taxa, have created debate and doubt regarding the efficacy and appropriateness of some genetic approaches. These concerns need continued discussion and eventual resolution as we move toward the irresistible attraction, and potentially enormous benefits, of the application of genetic approaches to protistan ecology.     

Risk of Budd-Chiari Syndrome Associated with Factor V Leiden and G20210A Prothrombin Mutation: A Meta-Analysis

Background

Various studies have demonstrated that factor V Leiden (FVL) and G20210A prothrombin mutation contribute to the risk of Budd-Chiari syndrome (BCS), while other studies provided conflicting findings. In order to derive more precise estimations of the relationships, a meta-analysis was performed.

Methods

Eligible articles were identified through search of databases including Pubmed, Chinese Biomedical Database (CBM, Chinese), and Chinese National Knowledge Infrastructure (CNKI, Chinese). Odd ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed- model.

Results

Finally, twelve studies were included for FVL and nine studies were included for G20210A prothrombin mutation. With respect to FVL, significantly increased BCS risk was found in the overall population (OR = 6.29, 95%CI = 4.23–9.36). Subgroup analyses suggested that FVL was associated with an increased risk of BCS in the population with high background mutation prevalence (>1% in the normal population). No significant association was found between BCS and G20210A prothrombin mutation (OR = 1.78, 95%CI = 0.77–4.11).

Conclusion

The presence of FVL should be evaluated in patients with BCS. Conversely, G20210A prothrombin mutation is not significantly associated with risk of BCS. Large-scale well designed studies are necessary to be conducted to further confirm or refute the observed association.