Computational Design and Analysis of a Multi-epitope Against Influenza A virus

International Journal of Peptide Research and Therapeutics - Influenza A viruses are among the most studied viruses, however no effective prevention against influenza infection has been developed....     

Establishment of rat brain endothelial cells susceptible to rat cytomegalovirus ALL-03 infection

Endothelial cells have been implicated as key cells in promoting the pathogenesis and spread of cytomegalovirus (CMV) infection. This study describes the isolation and culture of rat brain endothelial cells (RBEC) and further evaluates the infectious potential of a Malaysian rat CMV (RCMV ALL-03) in these cultured cells. Brain tissues were mechanically fragmented, exposed to enzymatic digestion, purified by gradient density centrifugation, and cultured in vitro. Morphological characteristics and expression of von Willebrand factor (factor VIII-related antigen) verified the cells were of endothelial origin. RBEC were found to be permissive to the virus by cytopathic effects with detectable plaques formed within 7 d of infection. This was confirmed by electron microscopy examination which proved the existence of the viral particles in the infected cells. The susceptibility of the virus to these target cells under the experimental conditions described in this report provides a platform for developing a cell-culture-based experimental model for studies of RCMV pathogenesis and allows stimulation of further studies on host cell responses imposed by congenital viral infections.     

How Long Depends on How Fast—Perceived Flicker Dilates Subjective Duration

How do humans perceive the passage of time and the duration of events without a dedicated sensory system for timing? Previous studies have demonstrated that when a stimulus changes over time, its duration is subjectively dilated, indicating that duration judgments are based on the number of changes within an interval. In this study, we tested predictions derived from three different accounts describing the relation between a changing stimulus and its subjective duration as either based on (1) the objective rate of changes of the stimulus, (2) the perceived saliency of the changes, or (3) the neural energy expended in processing the stimulus. We used visual stimuli flickering at different frequencies (4–166 Hz) to study how the number of changes affects subjective duration. To this end, we assessed the subjective duration of these stimuli and measured participants'' behavioral flicker fusion threshold (the highest frequency perceived as flicker), as well as their threshold for a frequency-specific neural response to the flicker using EEG. We found that only consciously perceived flicker dilated perceived duration, such that a 2 s long stimulus flickering at 4 Hz was perceived as lasting as long as a 2.7 s steady stimulus. This effect was most pronounced at the slowest flicker frequencies, at which participants reported the most consistent flicker perception. Flicker frequencies higher than the flicker fusion threshold did not affect perceived duration at all, even if they evoked a significant frequency-specific neural response. In sum, our findings indicate that time perception in the peri-second range is driven by the subjective saliency of the stimulus'' temporal features rather than the objective rate of stimulus changes or the neural response to the changes.     

Feasibility of Tomotherapy-Based Image-Guided Radiotherapy to Reduce Aspiration Risk in Patients with Non-Laryngeal and Non-Pharyngeal Head and Neck Cancer

Purpose

The study aims to assess the feasibility of Tomotherapy-based image-guided radiotherapy (IGRT) to reduce the aspiration risk in patients with non-laryngeal and non-hypopharyngeal cancer. A retrospective review of 48 patients undergoing radiation for non-laryngeal and non-hypopharyngeal head and neck cancers was conducted. All patients had a modified barium swallow (MBS) prior to treatment, which was repeated one month following radiotherapy. Mean middle and inferior pharyngeal dose was recorded and correlated with the MBS results to determine aspiration risk.

Results

Mean pharyngeal dose was 23.2 Gy for the whole group. Two patients (4.2%) developed trace aspiration following radiotherapy which resolved with swallowing therapy. At a median follow-up of 19 months (1–48 months), all patients were able to resume normal oral feeding without aspiration.

Conclusion and Clinical Relevance

IGRT may reduce the aspiration risk by decreasing the mean pharyngeal dose in the presence of large cervical lymph nodes. Further prospective studies with IGRT should be performed in patients with non-laryngeal and non-hypopharyngeal head and neck cancers to verify this hypothesis.     

Protein structure prediction assisted with sparse NMR data in CASP13

CASP13 has investigated the impact of sparse NMR data on the accuracy of protein structure prediction. NOESY and ¹⁵N-¹H residual dipolar coupling data, typical of that obtained for ¹⁵N,¹³C-enriched, perdeuterated proteins up to about 40 kDa, were simulated for 11 CASP13 targets ranging in size from 80 to 326 residues. For several targets, two prediction groups generated models that are more accurate than those produced using baseline methods. Real NMR data collected for a de novo designed protein were also provided to predictors, including one data set in which only backbone resonance assignments were available. Some NMR-assisted prediction groups also did very well with these data. CASP13 also assessed whether incorporation of sparse NMR data improves the accuracy of protein structure prediction relative to nonassisted regular methods. In most cases, incorporation of sparse, noisy NMR data results in models with higher accuracy. The best NMR-assisted models were also compared with the best regular predictions of any CASP13 group for the same target. For six of 13 targets, the most accurate model provided by any NMR-assisted prediction group was more accurate than the most accurate model provided by any regular prediction group; however, for the remaining seven targets, one or more regular prediction method provided a more accurate model than even the best NMR-assisted model. These results suggest a novel approach for protein structure determination, in which advanced prediction methods are first used to generate structural models, and sparse NMR data is then used to validate and/or refine these models.     

Up-regulation of Arl4a gene expression by broccoli aqueous extract is associated with improved spermatogenesis in mouse testes

Introduction: Broccoli (Brassica oleracea) is well known for its properties as an anticancer, antioxidant, and scavenger of free radicals. However, its benefits in enhancing spermatogenesis have not been well established.Objective: To study broccoli aqueous extract effects on sperm factors and the expression of genes Catsper1, Catsper2, Arl4a, Sox5, and Sox9 in sperm factors in mice.Material and methods: Male mice were divided randomly into six groups: (1) Control; (2) cadmium (3 mg/kg of mouse body weight); (3) orally treated with 200 µl broccoli aqueous extract (1 g ml^-1); (4) orally treated with 400 µl of broccoli aqueous extract; (5) orally treated with 200 broccoli aqueous extract plus cadmium, and (6) orally treated with 400 µl of broccoli aqueous extract plus cadmium. We analyzed the sperms factors and Catsper1, Catsper2, Arl4a, Sox5, and Sox9 gene expression.Results: An obvious improvement in sperm count and a slight enhancement in sperm motility were observed in mice treated with broccoli extract alone or with cadmium. Sperm viability was reduced by broccoli extract except for the 200 µl dose with cadmium, which significantly increased it. Interestingly, Arl4a gene expression increased in the 400 µl broccoli- treated group. Likewise, the Arl4a mRNA level in mice treated with cadmium and 200 µl of broccoli extract was higher than in the cadmium-treated mice. Furthermore, broccoli extract enhanced the mRNA level of Catsper2 and Sox5 genes in mice treated with 200 µl and 400 µl broccoli extract plus cadmium compared with the group treated solely with cadmium.Conclusion: The higher sperm count in broccoli-treated mice opens the way for the development of pharmaceutical products for infertile men.     

Fish as Bioreactors: Transgene Expression of Human Coagulation Factor VII in Fish Embryos

A plasmid containing human coagulation factor VII (hFVII) complementary DNA regulated by a cytomegalovirus promoter was microinjected into fertilized eggs of zebrafish, African catfish, and tilapia. The active form of hFVll was detected in the fish embryos by various assays. This positive expression of human therapeutic protein in fish embryos demonstrates the possibility of exploitation of transgenic fish as bioreactors.     

Antioxidant enzyme gene expression in congestive heart failure following mycardial infarction

Increased oxidative stress and reduction in antioxidant enzymes have been suggested to be involved in the pathophysiology of congestive heart failure subsequent to myocardial infarction (MI). The objective of the present study was to characterize changes in the mRNA abundance and protein levels for the enzymatic antioxidants, superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase during the sequelae of congestive heart failure in rats. MI was produced by the ligation of the left coronary artery and hearts from controls and 1, 4 and 16 week PMI groups were analyzed. Losartan treatment (2 mg/ml in drinking water, daily) was started at 4 weeks and continued for 12 weeks. The mRNA levels for SOD were reduced by about 40% at 1-week PMI, were near to the control levels at 4-week PMI and at 16 weeks PMI, the levels were reduced by about 73% below the controls. GSHPx mRNA levels remained unchanged at all time points. The mRNA levels for catalase remained unchanged at 1 and 4 weeks PMI and were significantly reduced by about 44% at 16 weeks PMI as compared to the controls. The protein levels for MnSOD, CuZnSOD, GSHPx at 1 and 16 weeks remained unchanged in treated and untreated PMI groups. However, the protein levels for catalase was significantly increased in the control and PMI groups treated with Losartan. It is concluded that changes in the SOD and catalase activities during severe heart failure correlated with changes in mRNA for these enzymes. The precise mechanism/s for the improvement in antioxidant reserve and protein levels after Losartan treatment is/are unclear at this time.     

Skeletal muscle ECF pH error signal for exercise ventilatory control

Evans, Allison B., Larry W. Tsai, David A. Oelberg, HomayounKazemi, and David M. Systrom. Skeletal muscle ECF pH error signalfor exercise ventilatory control. J. Appl.Physiol. 84(1): 90-96, 1998.An autonomic reflexlinking exercising skeletal muscle metabolism to central ventilatorycontrol is thought to be mediated by neural afferents having freeendings that terminate in the interstitial fluid of muscle. Todetermine whether changes in muscle extracellular fluid pH(pH_e) can provide an errorsignal for exercise ventilatory control,pH_e was measured duringelectrically induced contraction by³¹P-magnetic resonancespectroscopy and the chemical shift of a phosphorylated, pH-sensitivemarker that distributes to the extracellular fluid (phenylphosphonicacid). Seven lightly anesthetized rats underwentunilateral continuous 5-Hz sciatic nerve stimulation in an 8.45-Tnuclear magnetic resonance magnet, which resulted in a mixed lacticacidosis and respiratory alkalosis, with no net change in arterial pH.Skeletal muscle intracellular pH fell from 7.30 ± 0.03 units atrest to 6.72 ± 0.05 units at 2.4 min of stimulation and then roseto 7.05 ± 0.01 units (P < 0.05), despite ongoing stimulation and muscle contraction.Despite arterial hypocapnia, pH_eshowed an immediate drop from its resting baseline of 7.40 ± 0.01 to 7.16 ± 0.04 units (P < 0.05)and remained acidic throughout the stimulation protocol. During the on-and off-transients for 5-Hz stimulation, changes in the pH gradientbetween intracellular and extracellular compartments suggestedtime-dependent recruitment of sarcolemmal ion-transport mechanisms.pH_e of exercising skeletal musclemeets temporal and qualitative criteria necessary for a ventilatorymetaboreflex mediator in a setting where arterial pH doesnot.