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Main Causative Agent (main + causative_agent)
Selected AbstractsDevelopment of RNA interference (RNAi) as potential antiviral strategy against enterovirus 70JOURNAL OF MEDICAL VIROLOGY, Issue 6 2008Eng Lee Tan Abstract Enterovirus 70 (EV70) is recognized as the main causative agent of acute hemorrhagic conjunctivitis (AHC), a highly contagious viral infection of the eye. Currently, there is no available treatment for EV70 infections. In this study, we developed a potential intervention strategy using RNA interference (RNAi) against EV70 infection in an in vitro system. Two synthetic 19-mer siRNAs, si-3D1 and si-3D2, were designed to target the 3Dpol region of the EV70 genome. Significant dosage dependent inhibition of EV70 in rhabdomyosarcoma cell line, as shown by reduction of viral RNA and VP1 production, was observed. Both siRNAs prevented EV70 replication in RD cells when transfected into these cells 48 hr prior to virus infection. Introduction of these siRNAs into RD cells 1,3 hr after infection with EV70 reduced production of viral RNA by approximately 60%. Thus, RNAi is a promising strategy to prevent EV70 infections and may have therapeutic potential. J. Med. Virol. 80:1025,1032, 2008. © 2008 Wiley-Liss, Inc. [source] Involvement of trichothecenes in fusarioses of wheat, barley and maize evaluated by gene disruption of the trichodiene synthase (Tri5) gene in three field isolates of different chemotype and virulenceMOLECULAR PLANT PATHOLOGY, Issue 6 2006FRANK J. MAIER SUMMARY Fusarium graminearum is the main causative agent of Fusarium head blight on small grain cereals and of ear rot on maize. The disease leads to dramatic yield losses and to an accumulation of mycotoxins. The most dominant F. graminearum mycotoxins are the trichothecenes, with deoxynivalenol and nivalenol being the most prevalent derivatives. To investigate the involvement of trichothecenes in the virulence of the pathogen, the gene coding for the initial enzyme of the trichothecene pathway was disrupted in three field isolates, differing in chemotype and in virulence. From each isolate three individual disruption mutants were tested for their virulence on wheat, barley and maize. Despite the different initial virulence of the three wild-type progenitor strains on wheat, all disruption mutants caused disease symptoms on the inoculated spikelet, but the symptoms did not spread into other spikelets. On barley, the trichothecene deficient mutants showed no significant difference compared to the wild-type strains: all were equally aggressive. On maize, mutants derived from the NIV-producing strain caused less disease than their wild-type progenitor strain, while mutants derived from DON-producing strains caused the same level of disease as their progenitor strains. These data demonstrate that trichothecenes influence the virulence of F. graminearum in a highly complex manner, which is strongly host as well as moderately chemotype specific. [source] Epidemiology of Bovine Venereal Campylobacteriosis: Geographic Distribution and Recent Advances in Molecular Diagnostic TechniquesREPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2010GD Mshelia Contents Bovine venereal campylobacteriosis (BVC) is a major cause of economic loss to the cattle industries in different parts of the world. Camplylobacter fetus subsp. venerealis (Cfv), the main causative agent of BVC, is highly adapted to the genital tract of cattle and is transmitted by carrier bulls. However, infertility and abortions can also be caused by the intestinal pathogens C. fetus subsp. fetus (Cff), and C. jenuni, which are not venereally transmitted. Bovine venereal campylobacteriosis, caused by Cfv associated with lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancy rates and extended calving intervals, has the highest prevalence in developing countries where natural breeding in cattle is widely practised. The epidemiology, pathogenesis and diagnosis of the disease have been the subject of previous reviews. The main focus of this review is to highlight the epidemiology of this disease with particular reference to geographical distribution and recent advances in molecular diagnostic techniques. It is hoped that further research interest of scientists will be stimulated with a view to finding lasting solutions to the reproductive problems associated with the disease for better livestock productivity, particularly in developing endemic countries. [source] Underarm cosmetics and breast cancerJOURNAL OF APPLIED TOXICOLOGY, Issue 2 2003P. D. Darbre Abstract Although risk factors are known to include the loss of function of the susceptibility genes BRCA1/BRCA2 and lifetime exposure to oestrogen, the main causative agents in breast cancer remain unaccounted for. It has been suggested recently that underarm cosmetics might be a cause of breast cancer, because these cosmetics contain a variety of chemicals that are applied frequently to an area directly adjacent to the breast. The strongest supporting evidence comes from unexplained clinical observations showing a disproportionately high incidence of breast cancer in the upper outer quadrant of the breast, just the local area to which these cosmetics are applied. A biological basis for breast carcinogenesis could result from the ability of the various constituent chemicals to bind to DNA and to promote growth of the damaged cells. Multidisciplinary research is now needed to study the effect of long-term use of the constituent chemicals of underarm cosmetics, because if there proves to be any link between these cosmetics and breast cancer then there might be options for the prevention of breast cancer. Copyright © 2003 John Wiley & Sons, Ltd. [source] Eleven-year study of causes of neonatal bacterial meningitis in Ahvaz, IranPEDIATRICS INTERNATIONAL, Issue 3 2010Mohammad Hasan Aletayeb Abstract Background:, Bacterial meningitis is a devastating infection with a high mortality rate, especially in neonates. The aim of this study was to determine the causative agents that cause bacterial meningitis in Khuzestan province in the south-western region of Iran. Methods:, A descriptive, cross-sectional study was carried out from 1997 to 2007 at the neonatal ward of a university teaching hospital (Emam Khomeini hospital) in Ahvaz. All infants younger than 29 days old who suffered from meningitis were included. Laboratory tests included Gram stain, culture, and biochemical tests. Cases were defined as meningitis if the cerebrospinal fluid culture was positive. Results:, Based on cerebrospinal fluid culture, 31 infants were identified as having bacterial meningitis. Eleven (35.5%) of these cases were caused by Klebsiella pneumoniae, nine (29%) were caused by Enterobacter spp., three (9.6%) were caused by Escherichia coli, three (9.6%) were caused by Enterococcus spp., two (6.4%) were caused by Acinetobacter, and one case each (3.2%) was caused by Staphylococcus aureus, Pseudomonas aeruginosa and nontypeable Haemophilus influenzae. The male-to-female ratio was 2 : 1 (67.7% were male). The birthweights of 20 (64.5%) patients were under 2500 g and 11 (35.4%) patients had normal birthweights. Thirteen (42%) were early-onset cases and 18 (58%) were late-onset cases. More than half of the cases (54.8%) acquired the infection from the hospital. Blood cultures were positive for 18 (58%) patients. Thirty-two percent of cases died in spite of treatment. Conclusions:,Klebsiella pneumoniae and Enterobacter spp. were the two main causative agents that caused neonatal bacterial meningitis, and nosocomial meningitis was the most common type in our ward. [source] | |||||||||||||