251 research outputs found

    Genetic aspects of lactation curve traits and persistency indices in Friesian cows

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    SUMMARY A total of 4769 lactation records of 995 Friesian cows mated by 109 sires during the period from 1988 to 2008 were used to estimate lactation curve and breeding values (BV) for 305day milk yield (305dMY), lactation period (LP), peak yield (PY) and persistency indices (P 1 , P 2 and P 3 ). Data were analyzed using General Linear Model of SAS to determine the significant fixed effects. A Multi-trait animal model with Derivative-Free Restricted Maximum Likelihood procedures was used to estimate genetic and phenotypic parameters and breeding values for different traits studied. Month and year of calving, parity, and farm were considered as fixed effects in the analytical model, while animal, permanent environmental and residuals were included in the model as random effects. Means of 305-dMY, LP, PY, P 1 , P 2 and P 3 were 3407 kg, 292 d, 440 kg, 1.17, 5.66 and 10.8, respectively. Heritability estimates for the same traits were 0.30, 0.24, 0.29, 0.55, 0.67 and 0.39, respectively. Genetic correlations between different traits studied were positive and ranged from 0.87 to 0.97 for production traits, from 0.98 to 1.00 for persistency indices and from 0.29 to 0.78 between production traits and persistency indices. Average breeding values were 1678.19 kg for 305-dMY, 146.24 days for LP, 121.40 kg for PY, 1.03 for P 1 , 8.23 for P 2 and 14.15 for P 3 , respectively. Product moment correlation between BV estimates of different traits studied was positive and ranged from 0.55 to 0.80 for production traits, from 0.33 to 0.71 for persistency indices and production traits and from 0.95 to 0.98 for persistency indices. According to the moderate heritability estimate for milk traits, the high product correlations between BV for persistency indices estimates, it could be concluded that genetic improvement in milk production can be achieved through a selective breeding program. Selecting cows for peak yield will improve persistency and lactation curve traits in Friesian cows

    Is immersion in mint oil or apple vinegar solution a valid antifungal approach for acrylic soft liners?

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    Objectives: In-vitro assessment of the validity of immersion in mint oil or apple vinegar solutions as antifungal approach for acrylic soft liners. Materials and methods: Sixty disc-shaped specimens: 9mm in diameter and 2mm in length, and sixty cylinders: 12.5mm in diameter and 20mm in length of Vertex-Dental Heat-cured acrylic soft liner were prepared for antifungal activity and resilience measurements respectively. Specimens were divided into three groups; twenty in each, for immersion in mint oil, apple vinegar and distilled water (control). The groups were divided into four subgroups, five in each, for the different immersion periods: one day, one week, three weeks and six weeks. For each group, the daily immersion protocol was 8 h of immersion in the testing solution followed by 16 h in artificial saliva. This was repeated for each immersion period. Antifungal activity was assessed using disc diffusion method by measuring the inhibition zone for each disc twice: after 24 and 48 h incubation. Modulus of resilience was determined using a universal testing machine, where a stress-strain curve was obtained for each specimen and the area under the elastic portion of the curve was calculated. Results: A significantly higher antifungal activity was revealed following immersion in mint oil compared to apple vinegar solution. The immersion period was a significant variable for the antifungal activity measured after 24 h following immersion in either solution whereas it was an insignificant variable for the antifungal activity measured after 48 h following immersion in apple vinegar solution. A significant reduction in the antifungal activity was noted as the incubation period was increased from 24 to 48 h except after six weeks immersion in apple vinegar solution. Modulus of resilience of the acrylic soft liner was adversely affected by immersion in mint oil solution for more than one day and in apple vinegar solution for more than one week. Conclusions: Mint oil and Apple vinegar represent possible natural antifungal immersion solutions for acrylic soft liner provided that the immersion protocol is implemented properly

    Modulatory effects of perindopril on cisplatin-induced nephrotoxicity in mice: Implication of inflammatory cytokines and caspase-3 mediated apoptosis

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    Cisplatin-induced nephrotoxicity limits its anticancer effectiveness, thus this study’s aim was to assess the potential modulatory effect of perindopril on cisplatin-induced nephrotoxicity and to elucidate the possible underlying mechanisms. Renal dysfunction was induced in mice by a single injection of cisplatin (10 mg kg–1, i.p.) and perindopril was administered orally (2 mg kg–1, once daily) for 5 days. Perindopril remarkably ameliorated cisplatin-induced perturbations in renal histology, renal levels of tumor necrosis factor-alpha, interleukin-6 and interleukin-10, apoptosis-regulating protein expressions (Bax and Bcl2), and partially normalized Bax to Bcl2 ratio and active caspase 3 protein expression. Conversely, perindopril had no significant effect on cisplatin-induced elevations in serum creatinine and urea, microalbuminuria, kidney to body weight ratio, lipid peroxidation marker, superoxide dismutase and catalase activities and reduced glutathione content. In conclusion, perindopril may be safely used with cisplatin in mice since it ameliorated cisplatin-induced histopathological changes, inflammation and apoptosis without affecting renal biomarkers or oxidative stress

    Antisense oligonucleotide inhibition of hepatitis C virus genotype 4 replication in HepG2 cells

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    BACKGROUND: Hepatitis C (HCV) viral infection is a serious medical problem in Egypt and it has a devastating impact on the Egyptian economy. It is estimated that over 15% of Egyptians are infected by the virus and thus finding a cure for this disease is of utmost importance. Current therapies for hepatitis C virus (HCV) genotype 4 with interferon/ribavirin have not been successful and thus the development of alternative therapy for this genotype is disparately needed. RESULTS: Although previous studies utilizing viral subgenomic or full cDNA fragments linked to reporter genes transfected into adhered cells or in a cell free system showed promise, demonstration of efficient viral replication was lacking. Thus, we utilized HepG2 cells infected with native HCV RNA genomes in a replication competent system and used antisense phosphorothioate Oligonucleotides (S-ODN) against stem loop IIId and the AUG translation start site of the viral polyprotein precursor to monitor viral replication. We were able to show complete arrest of intracellular replication of HCV-4 at 1 uM S-ODN, thus providing a proof of concept for the potential antiviral activity of S-ODN on native genomic replication of HCV genotype 4. CONCLUSION: We have successfully demonstrated that by using two S-ODNs [(S-ODN1 (nt 326–348) and S-ODN-2 (nt 264–282)], we were able to completely inhibit viral replication in culture, thus confirming earlier reports on subgenomic constructs and suggesting a potential therapeutic value in HCV type 4

    Soluble egg antigen of Schistosoma Haematobium induces HCV replication in PBMC from patients with chronic HCV infection

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    BACKGROUND: This study was conducted to examine, in vitro , the effect of soluble egg antigen (SEA) of S. haematobium on intracellular HCV RNA load in peripheral mononuclear cells (PBMC) as well as on cell proliferation in patients with chronic HCV infection. METHODS: PBMC from 26 patients with chronic HCV infection were cultured for 72 hours in presence and absence of 50 μg SEA/ml medium. Intracellular HCV RNA quantification of plus and minus strands was assessed before and after stimulation. PBMC from five healthy subjects were cultured for 7 days, flow cytometric analysis of DNA content was used to assess the mitogenic effect of SEA on PBMC proliferation compared to phytoheamaglutinine (PHA). RESULTS: Quantification of the intracellular viral load showed increased copy number/cell of both or either viral strands after induction with SEA in 18 of 26 patients (69.2%) thus indicating stimulation of viral replication. Flow cytometric analysis showed that mean ± S.D. of percent values of cell proliferation was induced from 3.2 ± 1.5% in un-stimulated cells to 16.7 ± 2.5 % and 16.84 ± 1.7 % in cells stimulated with PHA and SEA respectively. CONCLUSION: the present study supports earlier reports on SEA proliferative activity on PBMC and provides a strong evidence that the higher morbidity observed in patients co-infected with schistosomiasis and HCV is related, at least in part, to direct stimulation of viral replication by SEA

    The effect of size, orientation and alloying on the deformation of AZ31 nanopillars

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    We conducted uniaxial compression of single crystalline Mg alloy, AZ31 (Al 3% wt. and Zn 1% wt.) nanopillars with diameters between 300–5000 nm with two distinct crystallographic orientations: (1) along the [0001] c-axis and (2) at an acute angle away from the c-axis, nominally oriented for basal slip. We observe single slip deformation for sub-micron samples nominally oriented for basal slip with the deformation commencing via a single set of parallel shear offsets. Samples compressed along the c-axis display an increase in yield strength compared to basal samples as well as significant hardening with the deformation being mostly homogeneous. We find that the “smaller is stronger” size effect in single crystals dominates any improvement in strength that may have arisen from solid solution strengthening. We employ 3D-discrete dislocation dynamics (DDD) to simulate compression along the [0001] and [1122] directions to elucidate the mechanisms of slip and evolution of dislocation microstructure. These simulations show qualitatively similar stress strain signatures to the experimentally obtained stress-strain data. Simulations of compression parallel to the [1122] direction reveal the activation and motion of only -type dislocations and virtually no dislocation junction formation. Computations of compression along [0001] show the activation and motion of both and dislocations along with a significant increase in the formation of junctions corresponding to the interaction of intersecting pyramidal planes. Both experiments and simulation show a size effect, with a differing exponent for basal and pyramidal slip. We postulate that this anisotropy in size effect is a result of the underlying anisotropic material properties only. We discuss these findings in the context of the effective resolved shear stress relative to the unit Burgers vector for each type of slip, which reveal that the mechanism that governs size effect in this Mg-alloy is equivalent in both orientations

    Antimicrobial activity of nature-inspired molecules against multidrug-resistant bacteria

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    Multidrug-resistant bacterial infections present a serious challenge to global health. In addition to the spread of antibiotic resistance, some bacteria can form persister cells which are tolerant to most antibiotics and can lead to treatment failure or relapse. In the present work, we report the discovery of a new class of small molecules with potent antimicrobial activity against Gram-positive bacteria and moderate activity against Gram-negative drug-resistant bacterial pathogens. The lead compound SIMR 2404 had a minimal inhibitory concentration (MIC) of 2 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate Staphylococcus aureus (VISA). The MIC values against Gram-negative bacteria such as Escherichia coli and Actinobacteria baumannii were between 8–32 μg/mL. Time-kill experiments show that compound SIMR 2404 can rapidly kill tested bacteria. Compound SIMR 2404 was also found to rapidly kill MRSA persisters which display high levels of tolerance to conventional antibiotics. In antibiotic evolution experiments, MRSA quickly developed resistance to ciprofloxacin but failed to develop resistance to compound SIMR 2404 even after 24 serial passages. Compound SIMR 2404 was not toxic to normal human fibroblast at a concentration of 4 μg/mL which is twice the MIC concentration against MRSA. However, at a concentration of 8 μg/mL or higher, it showed cytotoxic activity indicating that it is not ideal as a candidate against Gram-negative bacteria. The acceptable toxicity profile and rapid antibacterial activity against MRSA highlight the potential of these molecules for further studies as anti-MRSA agents
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