Time course and mechanisms of left ventricular systolic and diastolic dysfunction in monocrotaline-induced pulmonary hypertension

Although pulmonary hypertension (PH) selectively overloads the right ventricle (RV), neuroendocrine activation and intrinsic myocardial dysfunction have been described in the left ventricle (LV). In order to establish the timing of LV dysfunction development in PH and to clarify underlying molecular changes, Wistar rats were studied 4 and 6 weeks after subcutaneous injection of monocrotaline (MCT) 60 mg/kg (MCT-4, n = 11; MCT-6, n = 11) or vehicle (Ctrl-4, n = 11; Ctrl-6, n = 11). Acute single beat stepwise increases of systolic pressure were performed from baseline to isovolumetric (LVPiso). This hemodynamic stress was used to detect early changes in LV performance. Neurohumoral activation was evaluated by measuring angiotensin-converting enzyme (ACE) and endothelin-1 (ET-1) LV mRNA levels. Cardiomyocyte apoptosis was evaluated by TUNEL assay. Extracellular matrix composition was evaluated by tenascin-C mRNA levels and interstitial collagen content. Myosin heavy chain (MHC) composition of the LV was studied by protein quantification. MCT treatment increased RV pressures and RV/LV weight ratio, without changing LV end-diastolic pressures or dimensions. Baseline LV dysfunction were present only in MCT-6 rats. Afterload elevations prolonged τ and upward-shifted end-diastolic pressure dimension relations in MCT-4 and even more in MCT-6. MHC-isoform switch, ACE upregulation and cardiomyocyte apoptosis were present in both MCT groups. Rats with severe PH develop LV dysfunction associated with ET-1 and tenascin-C overexpression. Diastolic dysfunction, however, could be elicited at earlier stages in response to hemodynamic stress, when only LV molecular changes, such as MHC isoform switch, ACE upregulation, and myocardial apoptosis were present. J. Correia-Pinto and T. Henriques-Coelho contributed equally to this work.     

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目的探讨扇形切口在重唇手术中的应用。方法选择2009年5月至2010年5月郑州大学口腔医学院口腔颌面外科收治的重唇患者6例,采用扇形切口行重唇手术,观察临床疗效。结果术后6例患者的唇部形态及功能均良好。结论扇形切口是重唇整复术的可行性切口。     

颈夹脊穴长针深刺法治疗神经根型颈椎病的研究

目的观察长针深刺颈夹脊穴治疗神经根型颈椎病的疗效.方法采用长针深刺颈夹脊穴为主治疗神经根型颈椎病45例,同时设温针组35例进行对照观察.结果长针深刺组疗效优于温针组(P<0.05),其疗程明显短于温针组(P<0.01),临床症状的改善也优于温针组(P<0.05).结论神经根型颈椎病的疗效优劣与针刺深度和针感是否传至病变部位有关.     

A muscle-specific transgenic reporter line of the sea anemone,Nematostella vectensis

The sea anemone, Nematostella vectensis, has become an attractive new model organism for comparative genomics and evolutionary developmental biology. Over the last few years, many genes have been isolated and their expression patterns studied to gain insight into their function. More recently, functional tools have been developed to manipulate gene function; however, most of these approaches rely on microinjection and are limited to early stages of development. Transgenic lines would significantly enhance the tractability of the system. In particular, the study of gene- or tissue-specific promoters would be most useful. Here we report the stable establishment of a transgenic line using the I-SceI meganuclease system to facilitate integration into the genome. We isolated a 1.6-kb fragment of the regulatory upstream region of the Myosin Heavy Chain1 (MyHC1) gene and found that the transgene is specifically expressed in the retractor and tentacle muscles of Nematostella polyps, faithfully reproducing the expression of the endogenous MyHC1 gene. This demonstrates that the 1.6-kb fragment contains all of the regulatory elements necessary to drive correct expression and suggests that retractor and tentacle muscles in Nematostella are distinct from other myoepithelial cells. The transgene is transmitted through the germline at high frequency, and G₁ transgenic polyps have only one integration site. The relatively high frequency of transgenesis, in combination with gene- or tissue-specific promoters, will foster experimental possibilities for studying in vivo gene functions in gene regulatory networks and developmental processes in the nonbilaterian sea anemone, Nematostella vectensis.     

Persistent geotropic nystagmus—a different kind of cupular pathology and its localizing signs

Abstract

Conclusion. A persistent geotropic positional nystagmus indicates a dysfunction in the lateral semicircular canal with a cupula of less specific weight than the surrounding endolymph. It is possible to determine the side of the affected cupula by recording the nystagmus pattern in yaw and pitch plane. Objectives. To identify the clinical features in patients with a persistent geotropic positional nystagmus, establish lateralizing signs and relate the findings to a pathophysiologic mechanism. Patients and methods. Six patients with acute onset vertigo of a peripheral origin and persistent geotropic nystagmus were examined with videonystagmoscopy and the nystagmus characteristics in different positions of the head in yaw and pitch plane were studied. Results. Besides the persistent geotropic nystagmus, a zero zone was found with no nystagmus, beyond which the nystagmus changed direction when the head of the patient in supine position was gradually rotated from side to side. The zero zone was present when the head was turned slightly towards one side and is thought to represent a position where the affected cupula is aligned with the gravitational vertical. With the head bent forwards the nystagmus direction was to the non-affected side and when the head was bent backwards to the affected side.     

Phosphocreatine as a marker of contractile activity in single muscle fibres

ATP and phosphocreatine (PCr) were measured in randomly selected single fibres from control, 1- and 8-day low-frequency-stimulated rabbit tibialis anterior muscles. The fibres were classified according to their myosin heavy chain (MHC) complement as type I, IIA or IID. In 1-day stimulated muscle, which has previously been shown to exhibit a steep decline in force output, two fibre populations could be distinguished according to either normal or markedly depressed PCr levels. The fibre population exhibiting normal PCr levels encompassed a major fraction (65%) of type IID fibres and a minor fraction (35%) of IIA fibres. The population with reduced PCr levels comprised type I fibres (@50% reduced), the majority of type IIA fibres (@80% reduced), and a minor fraction of type IID fibres (@70% reduced). Levels of ATP were unaltered in type I and IIA fibres, but were @ 20% reduced in those IID fibres that exhibited low PCr levels. Assuming that those fibres that displayed reduced PCr levels were contracting, the IID and IIA fibres with normal PCr levels were regarded as metabolically recovering, non-contracting fibres. As previously shown, these fibres are transiently refractory during the early phase of low-frequency stimulation. After 8 days of chronic low-frequency stimulation, when force was shown to rise again, most fibres appeared more uniform with regard to reduced PCr and ATP levels. Our results suggest that PCr can be used as a sensitive measure of the degree of activity in single-fibre studies. Received: 14 January 1999 / Received after revision and accepted 21 April 1999     

12C6+重离子诱导可溶性TRAIL表达增强及其抗肿瘤作用的实验研究

目的构建可被辐射诱导激活的表达载体pEgr-sTRAIL,研究其体外瞬时转染联合不同剂量的^12C^6＋离子辐照对人宫颈癌HeLa细胞凋亡和增殖活性的影响。方法SOEing PCR法克隆可溶性TRAIL基因,测序正确后连入pcDNA3.1-Egr质粒,构建pEgr-sTRAIL表达载体;采用GeneCompanionTM聚阳离子转染试剂体外瞬时转染人宫颈癌HeLa细胞;接受不同剂量的^12C^6＋照射后,RT-PCR法检测目的基因 mRNA水平的表达,流式细胞术检测细胞凋亡,克隆形成实验检测细胞增殖存活。结果成功构建了辐射诱导表达载体pEgr-sTRAIL;瞬时转染联合^12C^6＋离子照射可在mRNA水平上诱导sTRAIL表达增强;随照射剂量的增加,转染pEgr-sTRAIL的HeLa细胞凋亡率明显增加,克隆形成率明显下降。结论^12C^6＋离子可诱导重组质粒pEgr-sTRAIL在被转染的HeLa细胞中表达增高,体外基因-^12C^6＋离子联合治疗可诱导肿瘤细胞凋亡明显增多,具有显著的肿瘤抑制作用。     

蛋白转导结构域介导乙型肝炎病毒聚合酶末端蛋白重链可变区抗体体外抑制病毒的复制

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.     

Brown Trout and European Minnow as Target Species for Genotoxicity Tests: Differential Sensitivity to Heavy Metals

Brown trout (Salmo trutta) and European minnow (Phoxinus phoxinus) were evaluated as target species to carry out genotoxicity tests. Assessment was made of their relative abundance in wild; their distribution areas; and their sensitivity to heavy metals, intraperitoneally exposing individuals of both species to a low dose (1.7 mg/kg body weight) of different heavy metals. Micronuclei were scored in renal erythrocytes 24 h after treatment. Cadmium chloride significantly induced micronuclei in both species whereas mercury nitrate induced micronuclei increase only in brown trout. Brown trout is abundant, present in all studied freshwater ecosystems, and more sensitive to toxic heavy metals than minnow; therefore it is presented as a target species for studies on heavy metal genotoxicity.