隐球菌性脑膜脑炎诊治进展

隐球菌病严重危害人类健康,中枢感染是高死亡率的主要原因,隐球菌性脑膜脑炎(Cryptococcal Meningoencephalitis,CM,简称"隐脑")早期诊断和有效治疗至关重要,本文就隐球菌性脑膜脑炎诊治进展进行综述。     

AQP4对隐球菌性脑膜脑炎脑水肿发生机制的研究进展

隐球菌性脑膜脑炎的发病率逐年提高,对人类健康危害大,死亡率高,颅内压增高是其最危险的临床表现之一,这主要与发病后炎症所致的脑水肿有关.本文就隐球菌性脑膜脑炎的病因、发病机制及其研究进展进行综述.     

隐球菌感染动物模型

动物模型在隐球菌研究中具有重要作用,其不仅是研究宿主感染隐球菌后病理生理、遗传免疫等反应的途径,也是研究宿主作用后隐球菌自身发生的生理学、细胞学及分子生物学变化的重要手段.隐球菌可以从许多动物分离到,如鸟类、禽类、啮齿类、灵长类等,其中部分如鸽类等并不处于疾病状态.     

侧脑室引流术在隐球菌性脑膜脑炎早期治疗中的应用

目的观察侧脑室引流术在隐球菌性脑膜脑炎早期治疗中的临床效果,探讨其有效性与安全性。方法对近年来我科治疗的5例初发隐球菌性脑膜脑炎伴高颅压患者的临床资料进行回顾性分析。结果 5例患者经早期行侧脑室引流后临床症状迅速缓解,撤除引流管后症状无加重;5例患者中无一例发生感染等并发症。联合抗真菌治疗后早期真菌学指标好转,长期随访中,4例患者临床治愈,无复发,1例死亡。结论侧脑室引流是隐球菌性脑膜脑炎早期治疗中快速、安全缓解头痛症状及减少并发症的有效手段。     

以新生隐球菌脑膜脑炎及梅毒为首发的艾滋病1例报道

艾滋病患者细胞免疫显著低下,艾滋病患者合并各种感染率显著增高,据报道约5%~15%的艾滋病患者发生隐球菌性脑膜脑炎[1],非洲艾滋病患者中隐球菌病的发生率可高达30%,美国6%~10%[2]。现将我院2007年1月4日收治的1例以隐球菌性脑膜脑炎和梅毒为首发表现的AIDS分析如下。1临床资料     

隐球菌性脑膜炎的诊断与治疗

隐球菌性脑膜炎是由隐球菌属,特别是新生隐球菌及格特隐球菌引起的机会性感染,在免疫抑制者及正常人群均可发病。隐球菌性脑膜炎早期诊断困难,即便接受治疗,患者死亡率仍然很高。在过去几年中,快速及时的检测及早期隐球菌抗原检查取得了重大进展。对晚期HIV感染者行血隐球菌荚膜抗原筛查并进行抢先治疗,有望阻止其进展为临床感染。目前抗真菌药物主要包括多烯类、唑类及氟胞嘧啶,未来药物研究的重点是疗效更好、毒性更小的新型口服抗真菌药。本文总结近几年隐球菌性脑膜炎的相关诊断及治疗进展,旨在对隐脑患者诊疗提供帮助。     

儿童隐球菌性脑膜炎早期诊断的研究进展

<正>隐球菌性脑膜炎(简称隐脑)是隐球菌由呼吸道感染后经血行播散至中枢神经系统引起的脑膜炎症,重者合并脑炎,预后差,死亡率高。隐球菌为条件致病性真菌,常继发于免疫力下降的人群,如艾滋病、淋巴瘤、糖尿病、营养不良及长期应用免疫抑制剂者。近年来,结核病、慢性肝炎等合并隐脑已有不少文献报道[1],同时由于艾滋病的流行日渐增多和免疫抑制剂的广泛应用,该病有明显增多趋势。儿童隐脑是严重的颅内感染性疾病,严重危害儿童健康,而且由于缺乏临床特异性及脑脊液检出率低,极易造成误诊及延误治疗,从而导致儿童的致残及死亡。因此早期诊断和及时有效     

慢性粒细胞性白血病并发新生隐球菌性脑膜脑炎1例

慢性粒细胞性白血病并发新生隐球菌性脑膜脑炎临床较少见,作者在临床工作中诊治本病患者1例,取得了满意疗效,报告如下:1资料与方法1.1临床资料患者女,29岁,因反复腹泻3年,头晕、乏力、左前臂斑片状淤斑2d于2004年7月3日就诊外院血液科。查血常规:白细胞28.37×109/L,中性幼稚细     

隐球菌病的诊治进展

隐球菌通常感染免疫功能低下的患者,荚膜多糖是其主要的致病因子,隐球菌主要通过肺进入机体从而引起肺隐球菌病,但因其嗜神经的特性,中枢神经系统也是隐球菌的主要靶器官。隐球菌感染的主要危险因素包括H IV感染和器官移植。由于感染部位的不同和患者的免疫功能的差异,其临床症状也多种多样,轻者无症状,重者危及生命。治疗方案主要由患者的免疫状态和病情的严重程度决定,主要包括多烯类和咪唑类抗真菌药物的治疗。即使经过抗真菌治疗,H IV患者隐球菌病的病死率仍较高,而CME(隐球菌性脑膜炎/脑膜脑炎)患者的临床治疗失败率之高让人难以接受。现介绍近年来隐球菌病在诊断和治疗方面的进展,并对未来治疗的发展趋势作简要的评价。     

新生隐球菌的AFLP分析

目的评估AFLP-DNA指纹技术在新生隐球菌分类中应用情况。方法新生隐球菌基因组DNA用双酶酶切,双链接头连于其酶切末端,用与接头和酶切位点互补的引物扩增DNA片段,其产物在高分辨的变性聚丙酰胺凝胶上电泳分离,然后进行银染。结果分析来自5种血清型和临床分离株的18株新生隐球菌,可见有30多条大小在30～500bp的DNA-AFLP指纹,相同的血清型有不同的指纹图谱,来自同一患者不同病期的两株分离株和来自同一患者患者的不同部位的两株分离株都显示出相同的带型。结论显示了AFLP的高分辨率,是适用于新生隐球菌流行病学调查的有力工具。     

The pursuit of cryptococcal pathogenesis: heterologous hosts and the study of cryptococcal host-pathogen interactions

Analysis of the molecular mechanisms by which a pathogen interacts with the human host is most commonly performed using a mammalian model of infection. However, several virulence-related genes previously shown to be involved in mammalian infection with Cryptococcus neoformans have also been shown to play a role in the interaction of these pathogens with invertebrates, such as Acanthamoeba castellanii, Caenorhabditis elegans, Dictyostelium discoideum, Drosophila melanogaster and Galleria mellonella. The study of host-pathogen interactions using these model hosts has allowed rapid screening of mutant libraries and can be used for the study of evolutionarily preserved aspects of microbial virulence and host response.     

病毒分子生物学诊断方法的应用进展

作为病毒诊断实验室必备的一种手段 ,PCR相关的病毒分子生物学诊断技术准确、快速、敏感、简便 ,对指导临床治疗十分重要。本文对近年来 PCR技术方法学研究与应用研究及生物传感器诊断病毒等方面的一些进展进行了综述     

铜绿假单胞菌随机扩增多态性DNA分子流行病学研究

目的了解医院感染的铜绿假单胞菌(Pa)的基因分型情况,为临床及时提供流行病学资料。方法采用随机扩增多态性DNA(RAPD)基因分型方法对从住院患者临床标本中分离的21株Pa进行分析。结果21株Pa共得14型,分型率为100.0%;以周为时限,Pa医院感染爆发流行有2起。结论RAPD技术可快速、准确地监控医院感染的流行株。     

Detection and identification of probable endemic fungal pathogen, Cryptococcus gattii, and worldwide pathogen, Cryptococcus neoformans, by real-time PCR

A real-time PCR method for detection and identification of Cryptococcus neoformans and Cryptococcus gattii was developed and evaluated using DNA from single-colony or koala nasal smears. Two TaqMan minor groove binder probes that distinguished between these species were designed corresponding to the internal sequences of the CAP59 gene for both species. The real-time PCR assay had 100% specificity, as assessed using 13 reference strains and 300 environmental strains. Twelve smear samples from healthy koalas were analyzed by direct real-time PCR. This method successfully detected C. gattii and C. neoformans in one and three koalas, respectively.     

分子生物学技术在双翅目实蝇科昆虫系统发育研究中的应用

分子生物学技术如同工酶电泳、RFLP、RAPD、核酸序列分析、微卫星DNA和探针杂交等,在实蝇科昆虫系统发育研究中具有重要作用。利用这些技术对实蝇种群进行系统发育研究,揭示其亲缘及进化关系,从生命本质上寻找实蝇种群间的内在联系。文章综述上述几种分子生物学技术在实蝇科昆虫核酸结构、种内和种间的亲缘及进化关系等方面的研究进展,分析在应用中存在的问题,展望这些分子生物学技术在实蝇科昆虫系统发育中的应用前景。     

DNA-binding study of anticancer drug cytarabine by spectroscopic and molecular docking techniques

The interaction of anticancer drug cytarabine with calf thymus DNA (CT-DNA) was investigated in vitro under simulated physiological conditions by multispectroscopic techniques and molecular modeling study. The fluorescence spectroscopy and UV absorption spectroscopy indicated drug interacted with CT-DNA in a groove-binding mode, while the binding constant of UV-vis and the number of binding sites were 4.0 ± 0.2 × 10⁴ L mol^?1 and 1.39, respectively. The fluorimetric studies showed that the reaction between the drugs with CT-DNA is exothermic. Circular dichroism spectroscopy was employed to measure the conformational change of DNA in the presence of cytarabine. Furthermore, the drug induces detectable changes in its viscosity for DNA interaction. The molecular modeling results illustrated that cytarabine strongly binds to groove of DNA by relative binding energy of docked structure ?20.61 KJ mol^?1. This combination of multiple spectroscopic techniques and molecular modeling methods can be widely used in the investigation on the interaction of small molecular pollutants and drugs with biomacromolecules for clarifying the molecular mechanism of toxicity or side effect in vivo.     

Quantitative evaluation of cryptococcal pathogenesis and antifungal drugs using a silkworm infection model with Cryptococcus neoformans

Aims: To develop an in vivo system that could quantitatively evaluate the therapeutic effects of antifungal drugs using a silkworm infection model with Cryptococcus neoformans. Methods and Results: Silkworms reared at 37°C died after an injection of viable serotype A C. neoformans fungus into the haemolymph. The serotype A C. neoformans, which is known to have higher mammal pathogenicity than the serotype D, was also more virulent against the silkworm. Furthermore, the deletion mutants of genes gpa1, pka1 and cna1, which are genes known to be necessary for the pathogenesis in mammals, showed an increase in the number of fungal cells necessary to kill half of the silkworm population (LD₅₀ value). Antifungal drugs, amphotericin B, flucytosine, fluconazole and ketoconazole, showed therapeutic effects in silkworms infected with C. neoformans. However, amphotericin B was not therapeutically effective when injected into the silkworm intestine, comparable to the fact that amphotericin B is not absorbed by the intestine in mammals. Conclusions: The silkworm–C. neoformans infection model is useful for evaluating the therapeutic effects of antifungal drugs. Significance and Impact of the Study: The silkworm infection model has various advantages for screening antifungal drug candidates. We can also elucidate the cryptococcal pathogenesis and evaluate the in vivo pharmacokinetics and toxicity of each drug.     

单分子测序技术在肿瘤诊断中的应用研究进展

肿瘤的发生发展通常与多个基因的遗传突变、表达异常有关,全面深入地分析肿瘤基因组、转录组及表观遗传组学对于快速剖析疾病特定基因簇及修饰位点至关重要。之前,研究者们主要采用第二代测序技术进行有效信息的挖掘,然而随着研究的不断深入,第二代测序技术表现出诸如序列拼接困难、低丰度难以检出等缺点。因此,单分子测序技术以其独特的优势应运而生,文中主要对单分子测序技术在几种常见肿瘤中的研究现状进行了综述,并展望了其在临床诊断中的应用前景。     

Orientation of DNA on a surface from simulation

DNA orientation near surfaces determines many properties related to hybridization efficiency. We performed a 40-ns molecular dynamics simulation to study the structure and orientation of a 12-base-pair DNA duplex tethered to a neutral, epoxide-coated silica surface. Starting with a canonical B-form tethered in an up-right position, normal to the surface, the DNA tilted to over 55 degrees and back. The time scale was a few nanoseconds for tilting events. The linker between the DNA and the surface went from standing upright to tilted, and finally collapsed on the surface. Although the DNA conformation fluctuated, it remained closed to B-form for the entire 40 ns. Calculations of helical parameters of the DNA show that the tethered end of the DNA changed its conformation noticeably when attracted to the surface.     

Characterization of the binding of paylean and DNA by fluorescence,UV spectroscopy and molecular docking techniques

The interaction of paylean (PL) with calf thymus DNA (ctDNA) was investigated using fluorescence spectroscopy, UV absorption, melting studies, ionic strength, viscosity experiments and molecular docking under simulated physiological conditions. Values for the binding constant K_a between PL and DNA were 5.11 × 10³, 2.74 × 10³ and 1.74 × 10³ L mol^–1 at 19, 29 and 39°C respectively. DNA quenched the intrinsic fluorescence of PL via a static quenching procedure as shown from Stern–Volmer plots. The relative viscosity and the melting temperature of DNA were basically unchanged in the presence of PL. The fluorescence intensity of PL–DNA decreased with increasing ionic strength. The value of K_a for PL with double‐stranded DNA (dsDNA) was larger than that for PL with single‐stranded DNA (ssDNA). All the results revealed that the binding mode was groove binding, and molecular docking further indicated that PL was preferentially bonded to A–T‐rich regions of DNA. The values for ΔH, ΔS and ΔG suggested that van der Waals forces or hydrogen bonding might be the main acting forces between PL and DNA. The binding distance was determined to be 3.37 nm based on the theory of Förster energy transference, which indicated that a non‐radiation energy transfer process occurred. Copyright © 2015 John Wiley & Sons, Ltd.