122 research outputs found

    Modulation of macrophage functions by sheeppox virus provides clues to understand interaction of the virus with host immune system

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    BACKGROUND: Poxviruses encode a range of immunomodulatory genes to subvert or evade the challenges posed by the innate and adaptive immune responses. However, the inactivated poxviruses possessed immunostimulating capacity and were used as a prophylactic or metaphylactic application that efficiently reduced susceptibility to infectious diseases in different species. This fact is intensively studied in different genera of poxviruses. However, little is known about the basic mechanisms adopted by sheeppox virus (SPPV). SPPV causes an acute disease of sheep that recently, has been observed to reinfect its host in spite of vaccination. RESULTS: By injecting inactivated or attenuated sheeppox virus SPPV vaccine in adult male Swiss mice, SPPV was found to reduce macrophages' functions in a local event that occurs at the site of application 12 h after vaccine administration as indicated by increased level of IL-10 and decreased level of SOD from cultured peritoneal macrophages. In contrast increased levels of IL-12, and SOD activity from cultured splenic macrophages, lymphocyte response to PHA-P, and in-vivo response to T-dependant Ag were detected. These effects were observed in both attenuated and inactivated SPPV, but more prominent in attenuated one. CONCLUSION: The results of this study help to elucidate, the phenomenon of existence natural SPPV infections in sheep instead of vaccination and the basic mechanisms responsible for the immunostimulating capacity of sheeppox virus. Locally, SPPV shows evidence for an immune escape mechanism that alleviates the host's immune response. Later and systemically, the virus protects the host from any fatal consequences of the immune system suppression

    A ring-connected dual active bridge based DC-DC multiport converter for EV fast-charging stations

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    This paper proposes a multiport DC-DC converter for EV fast-charging stations. The proposed converter is comprised of Ring-Connected Dual Active Bridge (RCDAB) DC-DC converters, where the connection point between every two adjacent DABs provides a DC port. Bypass switches are added to each DAB to eliminate unnecessary power processing stages in the event of idle ports (no EVs) (open circuit ports). The nature of the ring connection of the RCDAB theoretically allows infinite internal power flow solutions within the ring to satisfy a certain power flow scenario at the DC ports, hence, the optimal power flow solution can be selected to minimize total RMS current and losses. Single-phase shift control is applied to this optimization problem to make it simple. A novel closed-loop control scheme using Bisection optimization is developed to minimize the total RMS current. A control-hardware-in-the-loop (CHiL) validation is carried out for a 5-port network of the proposed topology to investigate the converter efficiency and fault tolerance/availability characteristics. Also, an experimental hardware validation is implemented for a 3-port network where different scenarios for power flow and faults are performed. Finally, a comparative discussion between the proposed topology and other multiport topologies in literature is presented revealing the superior performance of the RCDAB topology

    S1 gene sequence analysis of a nephropathogenic strain of avian infectious bronchitis virus in Egypt

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    BACKGROUND: Infectious bronchitis is highly contagious and constitutes one of the most common and difficult poultry diseases to control. IBV is endemic in probably all countries that raise chickens. It exists as dozens of serotypes/genotypes. Only a few amino acid differences in the S1 protein of vaccine and challenge strains of IBV may result in poor protection. Tropism of IBV includes the respiratory tract tissues, proventriculus and caecal tonsils of the alimentary tract, the oviduct and the kidney. RESULTS: Infectious bronchitis virus (IBV) strain closely related to Massachusetts (Mass) serotype was isolated from broiler chickens suffering from severe renal and respiratory distresses. The isolate was serologically identified by Dot-ELISA and further characterized by RT-PCR then genotyped using S1 gene sequence analysis. Alignment of the S1 sequence of the isolate with 16 IBV strains revealed high homology to isolates related to Mass serotype. Inoculation with the strain reproduced the disease in experimental 1-day-old chickens and resulted in 20% mortality, severe renal and moderate respiratory distresses. Marked histopathological changes in both kidney and trachea were observed in experimentally infected chickens. A protection study using the H120 live attenuated vaccine showed low protection rate in spite of high S1 sequence homology (97%). Protection based criteria were: virus re-isolation attempts from trachea, tracheal and renal histopathology as well as IBV antigens detection by immunofluorescent antibody technique in kidney sections. CONCLUSION: Periodical evaluation of cross-protective capabilities of IBV vaccine(s) versus recently recovered field isolates should be performed to ensure optimum control of IBV

    Immunohistochemistry for detection of avian infectious bronchitis virus strain M41 in the proventriculus and nervous system of experimentally infected chicken embryos

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    <p>Abstract</p> <p>Background</p> <p>Infectious bronchitis virus primarily induces a disease of the respiratory system, different IBV strains may show variable tissue tropisms and also affect the oviduct and the kidneys. Proventriculitis was also associated with some new IBV strains. Aim of this study was to investigate by immunohistochemistry (IHC) the tissue tropism of avian infectious bronchitis virus (IBV) strain M41 in experimentally infected chicken embryos.</p> <p>Results</p> <p>To this end chicken embryos were inoculated in the allantoic sac with 10<sup>3 </sup>EID<sub>50 </sub>of IBV M41 at 10 days of age. At 48, 72, and 120 h postinoculation (PI), embryos and chorioallantoic membranes (CAM) were sampled, fixed, and paraffin-wax embedded. Allantoic fluid was also collected and titrated in chicken embryo kidney cells (CEK). The sensitivity of IHC in detecting IBV antigens in the CAM of inoculated eggs matched the virus reisolation and detection in CEK. Using IHC, antigens of IBV were detected in nasal epithelium, trachea, lung, spleen, myocardial vasculature, liver, gastrointestinal tract, kidney, skin, sclera of the eye, spinal cord, as well as in brain neurons of the inoculated embryos. These results were consistent with virus isolation and denote the wide tissue tropism of IBV M41 in the chicken embryo. Most importantly, we found infection of vasculature and smooth muscle of the proventriculus which has not seen before with IBV strain M41.</p> <p>Conclusion</p> <p>IHC can be an additional useful tool for diagnosis of IBV infection in chickens and allows further studies to foster a deeper understanding of the pathogenesis of infections with IBV strains of different virulence. Moreover, these results underline that embryonic tissues in addition to CAM could be also used as possible source to generate IBV antigens for diagnostic purposes.</p

    The Potential Role of Azadirachta indica

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    Azadirachta indica A. Juss. (neem, family: Meliaceae) is perhaps the most commonly used traditional medicinal plant of India. In this study we investigated the protective effect of methanolic neem leaves extract (MNLE; 500 mg/Kg bwt) on rats treated with cisplatin (CDDP)-induced hepatotoxicity. Adult rats were randomly divided into four groups. CDDP was given to rats by intraperitoneal injection, while MNLE was given by oral gavage for 5 days after the CDDP injection. The injury and oxidative stress caused by CDDP on the liver and the effect of MNLE were evaluated by measuring (a) histological changes, (b) tissue biochemical oxidant and antioxidant parameters, and (c) investigating apoptosis markers immunohistochemically and by real time PCR. After treatment with MNLE, the histological damage and apoptosis induction caused by cisplatin were improved. Malondialdehyde and nitric oxide were significantly decreased; the antioxidant system, namely, glutathione content, glutathione-S-transferase, glutathione peroxidase, catalase, and superoxide dismutase activities were significantly elevated. In conclusion, MNLE may have a potential role when combined with cisplatin in chemotherapy to alleviate cisplatin-induced damage and oxidative stress in liver

    The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

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    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (Fragaria ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds

    World Society for Virology first international conference: Tackling global virus epidemics

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    This communication summarizes the presentations given at the 1st international conference of the World Society for Virology (WSV) held virtually during 16–18 June 2021, under the theme of tackling global viral epidemics. The purpose of this biennial meeting is to foster international collaborations and address important viral epidemics in different hosts. The first day included two sessions exclusively on SARS-CoV-2 and COVID-19. The other two days included one plenary and three parallel sessions each. Last not least, 16 sessions covered 140 on-demand submitted talks. In total, 270 scientists from 49 countries attended the meeting, including 40 invited keynote speakers.Peer reviewe

    Evaluation of growth and nutritional value of Brassica microgreens grown under red, blue and green LEDs combinations

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    39 p.-7 fig.-2 tab.-9 tab. supl.Microgreens are rich functional crops with valuable nutritional elements that have health benefits when used as food supplements. Growth characterization,nutritional composition profile of 21 varieties representing five species of the Brassica genus asmicrogreens were assessed under light-emitting diodes(LEDs) conditions. Microgreens were grown under four different LEDs ratios(%); red:blue 80:20 and 20:80 (R80:B20 and R20:B80), or red:green:blue 70:10:20 and 20:10:70 (R70:G10:B20 and R20:G10:B70). Results indicated that supplemental lighting with green LEDs (R70:G10:B20) enhanced vegetative growth and morphology, while blue LEDs (R20:B80) increased the mineral and vitamin contents. Interestingly, by linking the nutritional content with the growth yield to define the optimal LEDs setup, we found that the best lighting to promote the microgreen growth was the green LEDs combination (R70:G10:B20). Remarkably, under the green LEDs combination (R70:G10:B20) conditions,the microgreens of Kohlrabi purple, Cabbage red, Broccoli, Kale Tucsan, Komatsuna red, Tatsoi and Cabbage green, which can benefit human health in conditions with limited food, had the highest growth and nutritional content.This research work is a part of a project received seed funding from the Dubai Future Foundation through the Guaana.com open research platform(grant no. MBR026). Dr. Mortaza is supported from ERDF project “Plants as a tool from sustainable global development” No. CZ.02.1.01/0.0/0.0/16_019/0000827.Peer reviewe
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