Immunomodulatory effects of umbilical cord‐derived mesenchymal stem cells

Umbilical cord blood (UCB) is of great interest as a source of stem cells for use in cellular therapies. The immunomodulatory effect of mesenchymal stem cells (MSCs) originating from bone marrow, adipose tissue and amniotic membrane has previously been reported. In this study, MSCs were isolated from UCB with the aim of evaluating their immunomodulatory effects on proliferation of PB lymphocytes by two different techniques; namely, 5‐bromo‐2‐deoxyuridine ELISA and a carboxy fluorescein diacetate succinimidyl ester flow cytometric technique. MSCs were isolated from UCB, propagated until Passage four, and then characterized for cell surface markers by flow cytometry and ability to differentiate towards osteocytes and adipocytes. Immunosuppressive effects on PB lymphocytes were examined by co‐culturing mitomycin C‐treated UCB MSCs with mitogen‐stimulated lymphocytes for 72 hr. Thereafter, proliferation of lymphocytes was detected by CFSE flow cytometry and colorimetric ELISA. The titers of cytokines in cell culture supernatant were also assayed to clarify possible mechanisms of immunomodulation. UCB MSCs suppressed mitogen‐stimulated lymphocyte proliferation, which occurs via both cell‐cell contact and cytokine secretion. Titers of transforming growth factor beta and IL 10 increased, whereas that of IFN‐γ decreased in the supernatants of co‐cultures. Thus, UCB MSCs suppress the proliferation of mitogen‐stimulated lymphocytes. However further in vivo studies are required to fully evaluate the immunomodulatory effects of UCB MSCs.     

Influence of interleukin-2 and interferon-gamma in murine schistosomiasis

Schistosoma mansoni-infected mice were administered at the time of parasite residency in the lung with recombinant murine interleukin (IL)-2 or interferon-gamma (IFN-gamma), to evaluate the impact of cytokines in host responses to primary schistosomiasis. S. mansoni lung-stage schistosomula did not affect plasma lipids levels in BALB/c, while elicited significant (p<0.05) increase in free fatty acids (FA) and decrease in cholesterol plasma levels in C57BL/6 and CD1 mice, and stimulated expression of mRNA for Th2 cytokines in BALB/c and Th1 cytokines in C57BL/6 and CD1 mice. Production of specific antibodies was negligible in the 3 strains. Interleukin-2 treatment elicited significant (p<0.001) decrease in triglycerides (TG) in CD1, and decrease in TG and cholesterol plasma levels and down-regulation of TNF-alpha mRNA expression in C57BL/6 mice. Induction of type 2 cytokines and/or IFN-gamma mRNA expression did not lead to increase in percentage of specific antibody responders in any mouse strain. Exogenous IL-2-related reduction in cholesterol plasma levels and TNF-alpha mRNA expression in C57BL/6 mice was associated with significant (p<0.05) decrease in adult worm recovery and egg count. Treatment with IFN-gamma elicited significant (p<0.05) free FA plasma levels increase in BALB/c and C57BL/6 and decrease in CD1 mice. Expression of type 2 cytokines mRNA was stimulated in BALB/c and CD1 mice, yet was not accompanied with increase in humoral responses. Exogenous IFN-gamma-related reduction in free FA plasma levels and IFN-gamma mRNA response, and up-regulation of TNF-alpha mRNA expression in CD1 mice were associated with significant increase in adult worm burden and egg load. The data were discussed in an attempt to define host factors predictive of resistance to schistosome infection.     

Downregulation of leukotriene biosynthesis by thymoquinone attenuates airway inflammation in a mouse model of allergic asthma

Chronic airway inflammation is a key feature of bronchial asthma. Leukotrienes are potent inflammatory mediators that play a role in the pathophysiology of asthma, and their levels are elevated in the airways in response to allergen challenge. We examined the anti-inflammatory effect of thymoquinone (TQ), the active principle in the volatile oil of Nigella sativa seeds, on leukotriene (LT) biosynthesis in a mouse model of allergic asthma. Mice sensitized and challenged with ovalbumin (OVA) antigen had an increased amounts of leukotriene B4 and C4, Th2 cytokines, and eosinophils in bronchoalveolar lavage (BAL) fluid. In addition, there was also a marked increase in lung tissue eosinophilia and goblet cell numbers. Administration of TQ before OVA challenge inhibited 5-lipoxygenase, the main enzyme in leukotriene biosynthesis, expression by lung cells and significantly reduced the levels of LTB4 and LTC4. This was accompanied by a marked decrease in Th2 cytokines and BAL fluid and lung tissue eosinophilia, all of which are characteristics of airway inflammation. These results demonstrate the anti-inflammatory effect of TQ in experimental asthma.     

Human Fidgetin is a microtubule severing the enzyme and minus-end depolymerase that regulates mitosis

Fidgetin is a member of the AAA protein superfamily with important roles in mammalian development. Here we show that human Fidgetin is a potent microtubule severing and depolymerizing the enzyme used to regulate mitotic spindle architecture, dynamics and anaphase A. In vitro, recombinant human Fidgetin severs taxol-stabilized microtubules along their length and promotes depolymerization, primarily from their minus-ends. In cells, human Fidgetin targets to centrosomes, and its depletion with siRNA significantly reduces the velocity of poleward tubulin flux and anaphase A chromatid-to-pole motion. In addition, the loss of Fidgetin induces a microtubule-dependent enlargement of mitotic centrosomes and an increase in the number and length of astral microtubules. Based on these data, we propose that human Fidgetin actively suppresses microtubule growth from and attachment to centrosomes.     

Corrugation Architecture Enabled Ultraflexible Wafer‐Scale High‐Efficiency Monocrystalline Silicon Solar Cell

Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large‐scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon‐based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor‐based integration strategy where corrugation architecture enables ultraflexible and low‐cost solar cell modules from bulk monocrystalline large‐scale (127 × 127 cm²) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 µm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon‐based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 µm of the back contacts is shown that carries the solar cells segments.     

Mathematical and computational modeling in biology at multiple scales

A variety of topics are reviewed in the area of mathematical and computational modeling in biology, covering the range of scales from populations of organisms to electrons in atoms. The use of maximum entropy as an inference tool in the fields of biology and drug discovery is discussed. Mathematical and computational methods and models in the areas of epidemiology, cell physiology and cancer are surveyed. The technique of molecular dynamics is covered, with special attention to force fields for protein simulations and methods for the calculation of solvation free energies. The utility of quantum mechanical methods in biophysical and biochemical modeling is explored. The field of computational enzymology is examined.     

Morphological and biochemical changes in two parsley varieties upon water stress

The study was carried out to determine the responses of two parsley (Petroselinum crispum L.) hybrids; plain and curly- leafed to water stress. Besides the control, three irrigation treatments (10, 30 and 50 % of control water amount) were applied. Plant yield (leaf area, stem length and diameter, number of leaves) and quality (fresh and dry weights and concentrations of chlorophyll, carotenes, anthocyanins and vitamin C) were measured. The responses of plant yield and quality varied according to the hybrid and water treatment. The high quality was observed in curly- leafed parsley if compared to plain- leafed parsley, which had higher yield (stem length and diameter, leaf area). Moreover, water stress improved quality but decreased yield parameters in both hybrids.     

Lipid lowering activity of novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats

Abstract

Context: Dyslipidemia is a major risk factor for the development of cardiovascular diseases. Many dyslipidemic patients do not achieve their target lipid levels with the currently available medications, and most of them may experience many side effects.

Objective: The present work aimed toward identifying a new class of novel nicotinic acid-carboxamide derivatives as promising antihyperlipidemic compounds.

Materials and methods: Six novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives were synthesized using acid chloride pathways. All structures were confirmed using ¹H-NMR, ¹³C-NMR, IR, and HRMS. The evaluation of biological activity was conducted using Triton WR-1339-induced hyperlipidemic rats model.

Results: This study revealed that some of the newly synthesized novel N-(benzoylphenyl)pyridine-3-carboxamide derivatives mainly C4 and C6 possessed significant antihyperlipidemic activities on lipid components TG and TC (p value?<0.05).

Discussion and conclusion: This research opens the door for new potential antihyperlipidemic compounds derived from nicotinic acid that need further optimization of their biological activities.     

Improvement of rifemycins production by Amycolatopsis mediterranei in batch and fed-batch cultures

The production of rifamycins B and SV using glucose as main C-source by Amycolatopsis mediterranei in batch and fed-batch culture was investigated. Fed-batch culture using glucose as mono feeding substrate either in the form of pulse addition, in case of shake flask, or with constant feeding rate, in bioreactor level, proved to be an alternative production system with a significant increase in both volumetric and specific antibiotic production. The maximal concentrations of about 1146 mg/l and 2500 mg/l of rifamycins B and SV, respectively, was obtained in fed-batch culture in bioreactor level under non-oxygen limitation. On the other hand, the rate of rifamycins production was increased from 6.58 to 12.13 mg/l x h for rifamycin B and from 9.47 to 31.83 mg/l x h for rifamycin SV on the bioprocess transfer and improvement from the conventional batch cultivation in shake flask to fed-batch cultivation in stirred tank bioreactor.     

Comparing Different Classifiers in Sensory Motor Brain Computer Interfaces

A problem that impedes the progress in Brain-Computer Interface (BCI) research is the difficulty in reproducing the results of different papers. Comparing different algorithms at present is very difficult. Some improvements have been made by the use of standard datasets to evaluate different algorithms. However, the lack of a comparison framework still exists. In this paper, we construct a new general comparison framework to compare different algorithms on several standard datasets. All these datasets correspond to sensory motor BCIs, and are obtained from 21 subjects during their operation of synchronous BCIs and 8 subjects using self-paced BCIs. Other researchers can use our framework to compare their own algorithms on their own datasets. We have compared the performance of different popular classification algorithms over these 29 subjects and performed statistical tests to validate our results. Our findings suggest that, for a given subject, the choice of the classifier for a BCI system depends on the feature extraction method used in that BCI system. This is in contrary to most of publications in the field that have used Linear Discriminant Analysis (LDA) as the classifier of choice for BCI systems.