189 research outputs found
Studies on length-weight relationship of Gerres filamentosus Cuvier from the estuaries of the southern Karnataka coast
Random samples of Gerres filamentosus Cuvier from the Netravathi-Gurpur, Mulky, Kallayanapura, Mabukala and Kundapura estuaries of the southern Karnataka Coast were collected in the years 2000, 2001 and 2002, and length-weight relationships for each estuary were derived using multiple linear regression technique with one dummy variable. Hence, combined or sex-wise length-weight relationships were obtained after testing for homogeneity and isometric growth condition of fishes for each estuary by t-test. The extent of closeness of length-weight relationships between sexes and among estuaries for different years is explained by a trend line graph. The whole process of multiple linear regression analysis with one dummy variable is a better substitute for the analysis of covariance technique
Chandipura virus: a major cause of acute encephalitis in children in North Telangana, Andhra Pradesh, India
A hospital-based surveillance was undertaken between May 2005 and April 2006 to elucidate the contribution of Chandipura virus (CHPV) to acute viral encephalitis cases in children, seroconversion in recovered cases and to compare the seroprevalences of anti-CHPV IgM and N antibodies in areas reporting cases with those without any case of acute viral encephalitis. During this period, 90 cases of acute encephalitis were hospitalized in the pediatric wards of Mahatma Gandhi Memorial (MGM) Hospital, Warangal. There were 49 deaths (Case Fatality Rate, i.e., CFR of 54.4%). Clinical samples and records were obtained from 52 suspected cases. The cases were below 15 years, majority in 0-4 years (35/52, 67.3%). Computerized tomography (CT) scans and cerebro-spinal fluid (CSF) picture favored viral etiology. No neurological sequelae were observed. CHPV etiology was detected in 25 cases (48.1%, n = 52; RNA in 20, IgM in 3 and N antibody seroconversion in 2). JEV etiology was detected in 5 cases (IgM in 4 cases and seroconversion in 1 case). Anti-CHPV IgM seroprevalence in contacts (26/167, 15.6%) was significantly higher (P < 0.05) than in non-contacts (11/430, 2.6%); which was also observed in children < 15 years (19/90, 21.1% vs. 3/109, 2.7%). Anti-CHPV N antibody seroprevalence in <15 years contacts (66/90, 73.3%) and non-contacts (77/109, 70.6%) was significantly lower (P < 0.05) than in contacts (75/77, 97.4%) and non-contacts (302/321, 94.1%) more than 15 years respectively. CHPV appears to be the major cause of acute viral encephalitis in children in endemic areas during early monsoon months
SERCA2a gene therapy restores microRNA-1 expression in heart failure via an Akt/FoxO3A-dependent pathway
Microparticles: major transport vehicles for distinct microRNAs in circulation
AIMS: Circulating microRNAs (miRNAs) have attracted major interest as biomarkers for cardiovascular diseases. Since RNases are abundant in circulating blood, there needs to be a mechanism protecting miRNAs from degradation. We hypothesized that microparticles (MP) represent protective transport vehicles for miRNAs and that these are specifically packaged by their maternal cells. METHODS AND RESULTS: Conventional plasma preparations, such as the ones used for biomarker detection, are shown to contain substantial numbers of platelet-, leucocyte-, and endothelial cell-derived MP. To analyse the widest spectrum of miRNAs, Next Generation Sequencing was used to assess miRNA profiles of MP and their corresponding stimulated and non-stimulated cells of origin. THP-1 (monocytic origin) and human umbilical vein endothelial cell (HUVEC) MP were used for representing circulating MP at a high purity. miRNA profiles of MP differed significantly from those of stimulated and non-stimulated maternal THP-1 cells and HUVECs, respectively. Quantitative reverse transcription-polymerase chain reaction of miRNAs which have been associated with cardiovascular diseases also demonstrated significant differences in miRNA profiles between platelets and their MP. Notably, the main fraction of miRNA in plasma was localized in MP. Furthermore, miRNA profiles of MP differed significantly between patients with stable and unstable coronary artery disease. CONCLUSION: Circulating MP represent transport vehicles for large numbers of specific miRNAs, which have been associated with cardiovascular diseases. miRNA profiles of MP are significantly different from their maternal cells, indicating an active mechanism of selective 'packaging' from cells into MP. These findings describe an interesting mechanism for transferring gene-regulatory function from MP-releasing cells to target cells via MP circulating in blood
MicroRNAs in pulmonary arterial remodeling
Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH
Profiling of circulating microRNAs: from single biomarkers to re-wired networks
The recent discovery that microRNAs (miRNAs) are present in the circulation sparked interest in their use as potential biomarkers. In this review, we will summarize the latest findings on circulating miRNAs and cardiovascular disease but also discuss analytical challenges. While research on circulating miRNAs is still in its infancy, high analytical standards in statistics and study design are a prerequisite to obtain robust data and avoid repeating the mistakes of the early genetic association studies. Otherwise, studies tend to get published because of their novelty despite low numbers, poorly matched cases and controls and no multivariate adjustment for conventional risk factors. Research on circulating miRNAs can only progress by bringing more statistical rigour to bear in this field and by evaluating changes of individual miRNAs in the context of the overall miRNA network. Such miRNA signatures may have better diagnostic and prognostic value
PB1-F2 Proteins from H5N1 and 20th Century Pandemic Influenza Viruses Cause Immunopathology
With the recent emergence of a novel pandemic strain, there is presently intense interest in understanding the molecular signatures of virulence of influenza viruses. PB1-F2 proteins from epidemiologically important influenza A virus strains were studied to determine their function and contribution to virulence. Using 27-mer peptides derived from the C-terminal sequence of PB1-F2 and chimeric viruses engineered on a common background, we demonstrated that induction of cell death through PB1-F2 is dependent upon BAK/BAX mediated cytochrome c release from mitochondria. This function was specific for the PB1-F2 protein of A/Puerto Rico/8/34 and was not seen using PB1-F2 peptides derived from past pandemic strains. However, PB1-F2 proteins from the three pandemic strains of the 20th century and a highly pathogenic strain of the H5N1 subtype were shown to enhance the lung inflammatory response resulting in increased pathology. Recently circulating seasonal influenza A strains were not capable of this pro-inflammatory function, having lost the PB1-F2 protein's immunostimulatory activity through truncation or mutation during adaptation in humans. These data suggest that the PB1-F2 protein contributes to the virulence of pandemic strains when the PB1 gene segment is recently derived from the avian reservoir
Endothelial Mesenchymal Transition: Comparative Analysis of Different Induction Methods
Lack of Effective Anti-Apoptotic Activities Restricts Growth of Parachlamydiaceae in Insect Cells
The fundamental role of programmed cell death in host defense is highlighted by the multitude of anti-apoptotic strategies evolved by various microbes, including the well-known obligate intracellular bacterial pathogens Chlamydia trachomatis and Chlamydia (Chlamydophila) pneumoniae. As inhibition of apoptosis is assumed to be essential for a successful infection of humans by these chlamydiae, we analyzed the anti-apoptotic capacity of close relatives that occur as symbionts of amoebae and might represent emerging pathogens. While Simkania negevensis was able to efficiently replicate within insect cells, which served as model for metazoan-derived host cells, the Parachlamydiaceae (Parachlamydia acanthamoebae and Protochlamydia amoebophila) displayed limited intracellular growth, yet these bacteria induced typical features of apoptotic cell death, including formation of apoptotic bodies, nuclear condensation, internucleosomal DNA fragmentation, and effector caspase activity. Induction of apoptosis was dependent on bacterial activity, but not bacterial de novo protein synthesis, and was detectable already at very early stages of infection. Experimental inhibition of host cell death greatly enhanced parachlamydial replication, suggesting that lack of potent anti-apoptotic activities in Parachlamydiaceae may represent an important factor compromising their ability to successfully infect non-protozoan hosts. These findings highlight the importance of the evolution of anti-apoptotic traits for the success of chlamydiae as pathogens of humans and animals
miR-199a-5p Is Upregulated during Fibrogenic Response to Tissue Injury and Mediates TGFbeta-Induced Lung Fibroblast Activation by Targeting Caveolin-1
As miRNAs are associated with normal cellular processes, deregulation of miRNAs is thought to play a causative role in many complex diseases. Nevertheless, the precise contribution of miRNAs in fibrotic lung diseases, especially the idiopathic form (IPF), remains poorly understood. Given the poor response rate of IPF patients to current therapy, new insights into the pathogenic mechanisms controlling lung fibroblasts activation, the key cell type driving the fibrogenic process, are essential to develop new therapeutic strategies for this devastating disease. To identify miRNAs with potential roles in lung fibrogenesis, we performed a genome-wide assessment of miRNA expression in lungs from two different mouse strains known for their distinct susceptibility to develop lung fibrosis after bleomycin exposure. This led to the identification of miR-199a-5p as the best miRNA candidate associated with bleomycin response. Importantly, miR-199a-5p pulmonary expression was also significantly increased in IPF patients (94 IPF versus 83 controls). In particular, levels of miR-199a-5p were selectively increased in myofibroblasts from injured mouse lungs and fibroblastic foci, a histologic feature associated with IPF. Therefore, miR-199a-5p profibrotic effects were further investigated in cultured lung fibroblasts: miR-199a-5p expression was induced upon TGFβ exposure, and ectopic expression of miR-199a-5p was sufficient to promote the pathogenic activation of pulmonary fibroblasts including proliferation, migration, invasion, and differentiation into myofibroblasts. In addition, we demonstrated that miR-199a-5p is a key effector of TGFβ signaling in lung fibroblasts by regulating CAV1, a critical mediator of pulmonary fibrosis. Remarkably, aberrant expression of miR-199a-5p was also found in unilateral ureteral obstruction mouse model of kidney fibrosis, as well as in both bile duct ligation and CCl4-induced mouse models of liver fibrosis, suggesting that dysregulation of miR-199a-5p represents a general mechanism contributing to the fibrotic process. MiR-199a-5p thus behaves as a major regulator of tissue fibrosis with therapeutic potency to treat fibroproliferative diseases. © 2013 Lino Cardenas et al
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