关键词： Diatom-bacteria interactions   Transparent exopolymer particles   TEP   Dissolved organic carbon   Nutrient limitation   Lectin staining   Marino bacter adhaerens   Thalassiosira weissflogii  

摘要： In the ocean, exopolymer accumulation and the resulting aggregation of marine phytoplankton drive the flux of sinking organic matter. Little is known about the contribution of bacteria to the release and build-up of such exudates. We describe an in-depth investigation of exopolymer production under differing nutrient conditions using a diatom-bacteria model system. Responses of the marine diatom Thalassiosira weissflogii to different nutrient regimes and the impact of the co-incubated bacterium Marinobacter adhaerens on algal exudation were evaluated by analyzing quantity and quality of exudation products. Cultures of T. weissflogii were grown at nutrient-balanced conditions (Redfield ratio N:P = 16) as well as at nitrogen- or phosphorus-depleted conditions (N:P = 1 and N:P = 95, respectively) in the presence or absence of M. adhaerens. The impact of M. adhaerens on the concentration of dissolved organic carbon and transparent exopolymer particles (TEP), as well as on the composition of amino acids and carbohydrates, depended on the nutrient regime. Under nutrient-balanced conditions, M. adhaerens stimulated both T. weissflogii growth and TEP production. Under nutrient-depleted conditions, TEP production was enhanced regardless of whether bacteria were present. Phosphorus limitation resulted in an appreciable change in the %mol composition of dissolved amino acids in xenic and axenic treatments. Differential lectin staining revealed that the presence of M. adhaerens enhanced and modified the production of specific extracellular substances. A better understanding of the effects of diatom-bacteria interactions on the accumulation of exudation products is crucial in modelling and predicting consequences of environmental changes on oceanic organic matter and nutrient cycling.

关键词： 拷贝数变异   α地中海贫血   荧光定量PCR   分子筛查  

摘要： 一、α珠蛋白基因拷贝数变异的检测方法研究 拷贝数变异(Copy number variants, CNVs)是一种重要的结构变异,可通过改变基因的剂量或影响基因表达来改变表型或导致疾病。CNV在人类基因组中的分布非常普遍,可影响基因组中超过10%的序列。然而受限于检测手段,这类遗传变异直到最近几年才为研究者所重视并迅速成为当前人类遗传学研究的热点。 以我们熟悉的α珠蛋白基因为例,可以看到该基因的拷贝数变异与α地中海贫血(简称α地贫)的临床表型间存在密切联系。正常个体中存在4个α珠蛋白基因。当1～4个α珠蛋白基因相继发生缺失时,可分别导致以下几种不同的临床表型：其中1个基因缺失时为“静止型”,没有可检测的临床症状,无明显血液学改变；2个基因缺失时为“标准型”,表现为典型的小细胞、低色素性贫血；3个基因缺失时为“中间型”,表现为血红蛋白病即HbH病,有明显的甚至严重的贫血症状,患儿从1岁左右即出现贫血,严重者肝脾肿大及黄疸,面黄肌瘦并伴骨骼变化,靠输血维持生命；4个基因都缺失时为“重型”,表现为致死性巴氏水肿胎综合症,是最严重的一种,生下来就是死胎或很快就死亡。除缺失外,α珠蛋白基因的重复会产生5个拷贝的α珠蛋白基因(αααanti3.7/αα或αααanti4.2/αα),这一额外的α珠蛋白基因会导致β地贫患者的临床症状加重。我们通过对α珠蛋白基因拷贝数的定量来确定基因型,直接筛查出地中海贫血的高危人群。不仅如此,还可以α珠蛋白基因为模型,探索出一种适用于其它靶基因位点拷贝数检测的通用方法,以满足目前对CNV-疾病间关系研究的需要。 近年来,多种基于芯片的高通量方法用于识别全基因范围内的CNV,如芯片比较基因组杂交(Array comparative genomic hybridization, Array CGH)、SNP分型芯片(SNP genotyping arrays)以及深度测序方法(Deep sequencing-based approaches)。这些方法具有较高的分辨率,主要应用于全基因组范围CNV图谱的构建和疾病的关联分析,但并不适用于诊断针对某种疾病的特定基因位点的拷贝数变异。而针对靶基因位点CNV的检测方法有以下几种：多重可扩增探针杂交(Multiplex amplifiable probe hybridization, MAPH),多重连接探针扩增(Multiplex ligation-dependent probe amplification, MLPA),短荧光片段多重定量PCR (Quantitative multiplex PCR of short fluorescent fragments, QMPSF)以及实时荧光定量PCR(Real-time quantitative PCR)。作为筛查和诊断的目的,这几种方法都存在各自的优缺点。以目前应用较广泛的MLPA方法为例,该方法高效、特异,在一次反应中可以同时检测40多个靶序列拷贝数的改变。不足之处在于：1、开放式检测平台,容易造成污染;2、其设计的长探针不能通过普通的化学方法合成,需要通过M13载体克隆的方法获得；3、杂交步骤耗时过长(约16小时)。这些都限制了其作为分子筛查方法的推广和应用。 实时荧光定量PCR是比较受欢迎的检测平台,因为操作简便,快速高效,具有很高的敏感性和特异性；其次,是在封闭的体系中完成扩增并进行实时测定,有效的避免污染,而且直接检测结果,无需扩增后操作；另外,多荧光通道允许在同一反应体系中同时对多个靶序列进行扩增。该方法已广泛应用于针对特定位点进行拷贝数定量,对已知的CNV进行确认。但是多重PCR本身存在一些问题。如不同引物对之间的错配扩增,不同靶序列扩增效率不一致导致效率低的靶点被扩增效率较高的靶点所抑制,这些都会影响拷贝数定量分析。 为了更好的利用实时定量PCR的优势,同时又避免多重PCR扩增效率不一致的缺点,我们建立了一种基于多重加尾引物扩增的巢式实时荧光定量PCR的新方法。我们选择α珠蛋白基因作为建立该方法的候选基因。该方法的建立,有助于在人群中大规模筛查α珠蛋白基因的重复和缺失,建立一种可靠的分子筛查方法。在此基础上,有望成为一种适用于其它疾病相关的CNV进行快速分型的通用方法。 本方法的研究原理是针对特异位点序列设计加尾引物,包括上游引物和下游引物。经过有限循环的扩增后,扩增产物包含完整的基因组短片段序列及加尾序列。这样就将位点的起始拷贝数等比例转化为可供扩增的加尾产物的数目。然后加入通用引物及荧光检测探针,对不同位点的加尾产物同时扩增并记录荧光曲线Cq值。本研究将涉及到上述拷贝数变异的α1珠蛋白基因(简称α1)和α2珠蛋白基因(简称α2)作为待检基因,看家基因

关键词： Cardiac iron overload   Diagnostic power   Thalassemia major   Tissue doppler echocardiography  

摘要： Background and Aim: Iron overload in patients with thalassemia major is one of the most important complications of this disease and its cardiac complications are the most important causes of death in these *** T2 is the perfect device to assess the amount of iron deposited in the heart of thalassemia patients, but it causes waste of time and also is an expensive diagnostic method. Tissue Doppler echocardiography is the newer method for this ***, this study was conducted to determine efficacy and specificity of tissue Doppler echocardiography in the assessment of heart iron overload in patients with thalassemia major. Materials & Methods: It was a diagnostic power assessment research performed on 50 patients with thalassemia major aged ≥ 15 years old that had been visited in BoualiSina Hospital in sari, Iran. After the study was explained and patients agreed to participate, written informed consent was obtained. All the patients underwent MRI T2* and tissue Doppler echocardiography results were obtained. The collected data were processed with SPSS 16 and specificity and efficacy of tissue Doppler echocardiography were obtained. In all analysis, P value< 0.05 was considered statistically significant. Result: Patients were divided into four groups: normal amount of iron in the heart tissue, mild, moderate and severe. There was a good compatibility between results of MRI T2* and tissue Doppler echocardiography. Conclusion: we can offer that tissue Doppler echocardiography is a worthy method for evaluating cardiac complications of iron overload in patients with thalassemia major.

关键词： THALASSEMIA -- Genetic aspects   GENETIC testing   METHODOLOGY   HIGH performance liquid chromatography   MUTATION (Biology)   CHILDREN  

摘要： A response by Susan Goodness to a letter to the editor about his article 'Relationship between neonatal screening results by high performance liquid chromatography and the number of alpha-thalassaemia gene mutations - consequences for the cut-off' is presented.

关键词： beta- thalassemia   deferiprone   deferasirox  

摘要： Background Myocardial iron overload is the leading cause of death in patients with beta-thalassemia major. Combined therapy with deferiprone(DFP) and desferrioxamine (DFO) were suggested to be more effective than deferasirox(DFX) for removing heart iron. Deferasirox has recently been made available, but its long-term efficacy on cardiac function has not yet been established. Our study aimed to compare the effectiveness of deferiprone and desferrioxamine with deferasiroxon ventricular function in thalassemia major patients. Materials and Methods In this clinical trial study, 72 thalassemia major (TM) patients were randomised to receive either deferiprone combined with desferrioxamine and deferasirox, and thencardiac functions were evaluated. Data were analysed for left ventricular ejection fractions(LVEF) at baselinebyechocardiograpy, following 12 months of treatment. Results 72 TM patientswere enrolled in this study lasting 12 months, 36 TMwere placed on DFP/DFO (DFP, 50-86 mg/kg body weight;DFO, 24-52 mg/kg body weigh), 36 received DFX (range 18-40 mg/kg body weight). In 36 patients receiving combined therapy, left ventricular ejection fraction increased from 59.3+/-5.7% to 63.7+/-5.1% (p= 0.001) over 12 months [baseline LVEF values 56-61%]. Deferasirox showed no change in LVEF (p = 0.93). We found improvement of left ventricular ejection fractionsin the deferiprone combined with desferrioxamine versus the deferasirox group (P = 0.008). Conclusion The patients treated with combined therapy with deferiprone and desferrioxamine showed better systolic ventricular function compared to the patients treated with deferasirox. The patients treated with combined therapy with deferiprone and desferrioxamine showed better systolic ventricular function compared to the patients treated with deferasirox.

关键词： 红细胞脆性   平均红细胞体积   地中海贫血  

摘要： 目的分析红细胞脆性和平均红细胞体积在新生儿地贫筛查中的价值应用。方法通过血红蛋白电泳和PCR技术诊断,对48例确诊为地中海贫血患儿进行分析,包括血红蛋白电泳、基因型、血液学指标等项目。结果地中海贫血组的血红蛋白低于对照组的血红蛋白,且地中海贫血组的MCV明显较低,两组婴儿的网织红细胞计数、MCHC、MCH的差异无统计学意义(P>0.05)。α-地中海贫血与β-地中海贫血的Ret、Hb、MCHC、MCV、MCH、红细胞脆性比较差异无统计学意义。结论通过红细胞脆性和平均红细胞体积的有效运用,能够对新生儿地中海贫血患者进行快速的筛查,使相关并发症得到有效避免。

关键词： 血清铁蛋白   糖尿病   胰岛素分泌指数   胰岛素抵抗指数   空腹血糖受损  

摘要： 目的：调查广西重型β-地中海贫血患者糖尿病的患病率；探讨重型β-地中海贫血患者导致糖尿病发生的发病机制。 方法： 1、纳入本研究的重型β-地中海贫血患者125例,测定其中血清铁蛋白(SF)、空腹血糖(FBG)、空腹胰岛素(FINS)、糖化血红蛋白(HbAlc)。通过公式计算出胰岛素抵抗指数(HOMA-IR)、胰岛素分泌指数(HOMA-B)。采用pearson correlation相关分析铁蛋白(SF)与空腹血糖(FBG)、空腹胰岛素(FINS)、胰岛素分泌指数(HOMA-B)、胰岛素抵抗指数(HOMA-IR)之间的相关分析。采用多重线性回归分析评估各因素对血清铁蛋白的影响,并建立回归方程。同时对所有患者分为地贫组及地贫合并血糖异常组,对两组之间的FBG、HbAlc、FINS、HOMA-B、HOMA-IR,采用两样本的T-test进行比较. 2、按血清铁蛋白浓度分3组：A组：SF<2500ng/L;B组：SF≥2500ng/L,<5000ng/L;C组：SF>5000ng/L三组应用完全随机设计的方差分析(One-Way ANOVA)并做S-N-K两两比较各因素之间的差别。 结果： 1、重型β-地中海贫血糖尿病的发病率随着年龄逐渐升高,10-15岁患儿发病率最高,在这个阶段空腹血糖受损患病率为20.9%,糖尿病患病率是23.1%。 2、对125例重型B-地中海贫血患者糖化血红蛋白与年龄做pearson correlation相关分析,r=0.24p=000<0.01,随着年龄的增长,糖化血红蛋白也越来越高,有明显的正相关. 3、血清铁蛋白(SF)水平与胰岛素抵抗指数(HOMA-IR)、空腹血糖(FBG)呈正相关,具有统计学意义(P<0.01),但与胰岛素分泌指数负相关(P<0.01)。 4、地贫合并血糖异常与地贫无血糖异常的两组患者进行比较,空腹血糖、空腹胰岛素、胰岛素分泌指数、胰岛素抵抗指数有明显差异(P<0.01),但两组间的糖化血红蛋白无明显差别(P<0.05)。 结论： 1.广西重型B-地中海贫血患者糖尿病的发病率为4%,空腹血糖受损率为16%,重型β-地中海贫血患者糖尿病的发病率随年龄逐渐升高,10-15岁患儿发病率最高,在这个阶段空腹血糖受损患病率为20.9%,糖尿病患病率是23.1%。 2.重型β-地中海贫血患者糖尿病患者的铁过载对机体造成胰岛素抵抗及胰岛素的分泌功能下降,可能是糖尿病发病的主要发病机制。

关键词： 异基因造血干细胞移植   重型β-地中海贫血   单倍体   肝静脉闭塞综合病   出血性膀胱炎   移植物抗宿主病   侵袭性真菌感染   口腔黏膜炎   巨细胞病毒感染  

摘要： 目的 异基因造血干细胞移植（allo-hematopoietic stem cell transplantation, allo-HSCT）是目前根治重型p-地中海贫血的唯一方法。人类主要组织相容性抗原（human leucocyte antigen,HLA）全相合的亲缘相关或无关供者是allo-HSCT最合适的供者,然而仅有20%～30%的患者能找到HLA相合的亲缘供者,在无关人群中找到相合供者的概率是1/5万～1/10万,甚至更低,而且需要消耗很长的时间去骨髓库检索。若进行HLA单倍体造血干细胞移植,则将有90%的患者能够找到供者,解决供者难找的问题,进而为更多需接受移植治疗而无HLA相合供者的患者带来福音,但是单倍体移植面临着造血重建延迟、移植物抗宿主病重、免疫重建延迟、感染及移植失败的诸多问题。目前有关HLA单倍体治疗地中海贫血的研究较少,主要为白血病方面的研究,本课题将通过回顾性分析探讨单倍体移植治疗重型β-地中海贫血的临床疗效,更好的指导我们今后的工作。 方法 1999年8月至2011年10月我移植中心对21例患重型β-地中海贫血（以下简称地贫）的患者行单倍体造血干细胞移植。分为两组：08年以前移植的地贫患者11人,患者年龄2岁～13岁,中位年龄6岁,男孩9人,女孩2人,地贫临床分度：Ⅰ-Ⅱ度7例,Ⅲ度4例,HLA配型均为高分辨1个位点不合。干细胞来源为父母的骨髓（BM）,其中单个核细胞数中位数为2.5×108/kg（1.94-5.4×108/kg）,其中2例第一次移植失败后3个月内分别进行了第二及第三次移植,结局都是移植失败。08年以后移植的地贫患者10人,患者年龄3岁-11岁,中位年龄5.5岁,男孩,4人,女孩6人。地贫临床分度：Ⅰ～Ⅱ度9例,Ⅲ度1例,HLA配型高分辨1个位点不合有8例,HLA配型高分辨全相合2例。干细胞来源为父母外周血造血干细胞（PBSC）。输注外周干细胞的单个核细胞数为中位数8.62（8～9）×108/Kg,其中1例移植后进行供者淋巴细胞输注（DLI）3次。 1、预处理方案：08年以前预处理方案以马法兰（Bu）+环磷酰胺（Cy）+抗人胸腺兔免疫球蛋白（ATG-F）为主。在此基础上加用氟达拉滨（Flud）或者全身放疗（TBI）。其中1例第二次移植用马法兰（Bu）+环磷酰胺（Cy）+抗人胸腺兔免疫球蛋白（ATG-F）+氟达拉滨（Flud）,第三次移植采用环磷酰胺（Cy）+足叶乙甙（Vpl6）+全身放疗（TBI）。另外1例第二次移植采用环磷酰胺（Cy）+全身放疗（TBI）。08年以后预处理方案均采用静脉马法兰（Bu）+环磷酰胺（Cy）+氟达拉滨（Flud）+塞替派（TT）+抗人胸腺兔免疫球蛋白（ATG-F）方案。 2、移植物抗宿主病（graft-versus-host disease GVHD）的预防：08年以前移植患者采用环孢素A（CsA）+霉酚酸酯（MMF）,再此基础上加或不加“短疗程”甲氨蝶呤（MTX）,出现GVHD者给予达利珠单抗（赛尼哌）或抗CD25单抗（舒莱）。08年以后移植患者采用环孢素A（CsA）+霉酚酸酯（MMF）+“短疗程”甲氨蝶呤（MTX）。用法：08年以前CsA在移植前一天开始维持20小时静脉注射,监测血药浓度维持在150～250ug/L之间,MTX在移植后+1day、+3day、+6day、+llday应用,剂量分别为15mg/m2、10mg/m2、10mmg/m2、10mg/m2;MMF在移植后6小时开始按30mg/***口服应用。08年以后移植患者CsA在预处理开始（1.5mg/***）当天即给予20小时持续静脉注射,移植前一天开始（3mg/***）维持20小时静脉注射,监测血药浓度维持在150-250ug/L之间,MTX在移植后+1day、+3day、+6day应用,剂量分别为15mg/m2、10mg/m2、10mg/m;MMF在移植后6小时开始按30mg/***口服应用。 3、肝静脉闭塞病（HVOD）的预防：08年以前移植患者在移植后第1天开始静脉应用肝素钠（100～150U/***）、质脂体前列素E1（10～30ug/d）。08年以后移植患者在预处理开始即开始给予肝素钠（100U/***）、质脂体前列素E1（10～30ug/d）和熊去氧胆酸（12mg/Kg.d）口服。期间监测肝功能及凝血功能,若无显著肝静脉闭塞病表现则在移植后20天停药。 4、出血性膀胱炎（HC）的预防：在预处理期间水化碱化尿液,保证每小时尿量大于60～100ml/m2：同时应用美司钠：在第一剂环磷酰胺前半小时开始,加入生理盐水中持续静脉注射24小时;每天美斯钠的剂量=1.25×每天CY量,治疗主要采用采用水化+血小

关键词： 地中海贫血   筛查   预防   出生缺陷  

摘要： 地中海贫血又称海洋性贫血,是一种较为常见的遗传性疾病。据相关研究表明,地中海贫血与出生缺陷有着极为密切的联系。本文就产前地中海贫血筛查与预防出生缺陷之间的关系进行了研究,对地中海贫血的病因、诊断和筛查方法,以及产前地中海贫血筛查的作用等几个方面进行综述。

关键词： Bangladesh   anemia   iron-deficiency   thalassemia   women  

摘要： Iron deficiency was absent in a recent population assessment of rural Bangladeshi women exhibiting anemia (57%), suggesting other causes of low hemoglobin. We assessed the relative influence on anemia of thalassemia, groundwater arsenic and iron, and diet among women of reproductive age living in rural Bangladesh. Women (n=207) sampled from a previous antenatal nutrient intervention trial in rural Bangladesh were visited during two seasons in 2008. Collected data included 7-day dietary and 24-hour drinking water intake recalls, 7-day morbidity recall, anthropometry, and drinking water arsenic and iron concentrations. Capillary blood was analyzed for iron (plasma ferritin, soluble transferrin receptor), inflammation (C-reactive protein) and thalassemia thalassemia and Hb E) status. In stratified, adjusted analyses, only parity was associated with anemia (odds ratio, OR (95% CI): 11.34 (1.94, 66.15)) for those with thalassemia (28% prevalent). In contrast, groundwater iron intake (>30 mg/d, 0.48 (0.24, 0.96)) and wasting (2.32 (1.17, 4.62)) were associated with anemia among those without thalassemia. Elevated groundwater arsenic (>50 mu g/L, 12% of tubewells) and a diverse diet were unrelated to anemia regardless of thalassemia diagnosis (p>0.70 and >0.47, respectively). Among women in this typical rural Bangladeshi area, the prevalence of thalassemia was high and, unlike iron deficiency which was absent most likely due to high iron intake from groundwater, contributed to the risk of anemia. In such settings, the influence of environmental sources of iron and the role of thalassemias in contributing to anemia at the population level may be underappreciated.