Use of response surface methodology to study the effect of media composition on aflatoxin production by Aspergillus flavus

Aflatoxins are one of the most important secondary metabolites. These extrolites are produced by a number of Aspergillus fungi. In this study, we demonstrate the effect of media components and enhanced aflatoxin yield shown by A. flavus using response surface methodology in response to different nutrients. Different components of a chemically defined media that influence the aflatoxin production were monitored using Plackett–Burman experimental design and further optimized by Box–Behnken factorial design of response surface methodology in liquid culture. Interactions were studied with five variables, namely sorbitol, fructose, ammonium sulfate, KH₂PO₄, and MgSO₄.7H₂O. Maximum aflatoxin production was envisaged in medium containing 4.94 g/l sorbitol, 5.56 g/l fructose, 0.62 g/l ammonium sulfate, 1.33 g/l KH₂PO₄, and 0.65 g/l MgSO₄·7H₂O using response surface plots and the point prediction tool of the DESIGN EXPERT 8.1.0 (Stat-Ease, USA) software. However, a production of 5.25 μg/ml aflatoxin production was obtained, which was in agreement with the prediction observed in verification experiment. The other component (MgSO₄.7H₂O) was found to be an insignificant variable.     

Dating the “red beds” of the Eastern Moroccan High Plateaus: Evidence from late Late Cretaceous charophytes and dinosaur eggshells

A new locality in the poorly known “red beds” of Tendrara (High Plateaus, Morocco) has yielded four charophytes species (Feistiella anluensis, Lamprothamnium stipitatum, Peckisphaera portezueloensis, Platychara caudata) and dinosaur eggshells (Pseudomegaloolithus atlasi). These red beds, which overly the Cenomanian-Turonian marine deposits, generally assigned to “Senonian” based on geometric position, are directly dated by these fossils: the charophytes species and dinosaur oospecies association indicates a Campano-Maastrichtian or Maastrichtian age for these calm floodplain deposits.     

Involvement of the glutamate receptor AtGLR3.3 in plant defense signaling and resistance to Hyaloperonospora arabidopsidis

Like their animal counterparts, plant glutamate receptor‐like (GLR) homologs are intimately associated with Ca²⁺ influx through plasma membrane and participate in various physiological processes. In pathogen‐associated molecular patterns (PAMP)‐/elicitor‐mediated resistance, Ca²⁺ fluxes are necessary for activating downstream signaling events related to plant defense. In this study, oligogalacturonides (OGs), which are endogenous elicitors derived from cell wall degradation, were used to investigate the role of Arabidopsis GLRs in defense signaling. Pharmacological investigations indicated that GLRs are partly involved in free cytosolic [Ca²⁺] ([Ca²⁺]_cyt) variations, nitric oxide (NO) production, reactive oxygen species (ROS) production and expression of defense‐related genes by OGs. In addition, wild‐type Col‐0 plants treated with the glutamate‐receptor antagonist 6,7‐dinitriquinoxaline‐2,3‐dione (DNQX) had a compromised resistance to Botrytis cinerea and Hyaloperonospora arabidopsidis. Moreover, we provide genetic evidence that AtGLR3.3 is a key component of resistance against H. arabidopsidis. In addition, some OGs‐triggered immune events such as defense gene expression, NO and ROS production are also to different extents dependent on AtGLR3.3. Taken together, these data provide evidence for the involvement of GLRs in elicitor/pathogen‐mediated plant defense signaling pathways in Arabidopsis thaliana.     

Mesenchymal stem cell transfusion for desensitization of positive lymphocyte cross‐match before kidney transplantation: outcome of 3 cases

Objectives

Donor specific antibodies (DSA) and a positive cross‐match are contraindications for kidney transplantation. Trials of allograft transplantation across the HLA barrier have employed desensitization strategies, including the use of plasmapheresis, intravenous immunoglobulins, anti‐B‐cell monoclonal antibodies and splenectomy, associated with high‐intensity immunosuppressive regimens. Our case 1 report suffered from repeatedly positive lymphocyte cross match after 1st renal transplantation. Graft nephrectomy could not correct the state of sensitization. Splenectomy was done in a trial to get rid of the antibody producing clone. Furthermore plasmapheresis with low dose IVIG could not as well revert the state of sensitization for the patient.

Material and methods

About 50 millions donor specific MSCs were injected to the patient.

Results

MSCs transfusion proved to be the only procedure which could achieve successful desensitization before performing the second transplantation owing to their immunosuppressive properties.

Conclusion

This case indicates that DS‐MSCs is a potential option for anti‐HLA desensitization. In cases 2 and 3 IV DS‐MSCs transfusion was selected from the start as a successful line of treatment for pre renal transplantation desensitization to save other unnecessary lines of treatment that were tried in case 1.

     

The removal of ρ-chlorophenol in aqueous cultures with free and alginate-immobilized cells of the microalga Tetraselmis suecica

The present study aimed at evaluating the ability of some isolated cyanobacterial and microalgal strains for the removal of ρ-chlorophenol (ρ-CP), an environmentally harmful contaminant. To identify the most efficient species, a screening program was carried out using 15 microalgal and cyanobacterial strains. Among them, Tetraselmis suecica was able to remove 67 % of the ρ-chlorophenol at an initial concentration of 20 mg L^?1 from the medium within a 10-day period. The efficacy of the process was dependent on the ρ-chlorophenol concentration. At concentrations above 60 mg L^?1 of the pollutant, no removal was observed due to the inhibitory effect of ρ-chlorophenol on the T. suecica cells. The effect of cell immobilization in alginate beads on T. suecica removal capacity was also examined. Using this technique, the removal efficacy for the initial ρ-CP concentration of 20 mg L^?1 increased up to 94 %.     

Aldose Reductase Inhibition Prevents Allergic Airway Remodeling through PI3K/AKT/GSK3β Pathway in Mice

Background

Long-term and unresolved airway inflammation and airway remodeling, characteristic features of chronic asthma, if not treated could lead to permanent structural changes in the airways. Aldose reductase (AR), an aldo-sugar and lipid aldehyde metabolizing enzyme, mediates allergen-induced airway inflammation in mice, but its role in the airway remodeling is not known. In the present study, we have examined the role of AR on airway remodeling using ovalbumin (OVA)-induced chronic asthma mouse model and cultured human primary airway epithelial cells (SAECs) and mouse lung fibroblasts (mLFs).

Methods

Airway remodeling in chronic asthma model was established in mice sensitized and challenged twice a week with OVA for 6 weeks. AR inhibitor, fidarestat, was administered orally in drinking water after first challenge. Inflammatory cells infiltration in the lungs and goblet cell metaplasia, airway thickening, collagen deposition and airway hyper-responsiveness (AHR) in response to increasing doses of methacholine were assessed. The TGFβ1-induced epithelial-mesenchymal transition (EMT) in SAECs and changes in mLFs were examined to investigate AR-mediated molecular mechanism(s) of airway remodeling.

Results

In the OVA-exposed mice for 6 wks inflammatory cells infiltration, levels of inflammatory cytokines and chemokines, goblet cell metaplasia, collagen deposition and AHR were significantly decreased by treatment with AR inhibitor, fidarestat. Further, inhibition of AR prevented TGFβ1-induced altered expression of E-cadherin, Vimentin, Occludin, and MMP-2 in SAECs, and alpha-smooth muscle actin and fibronectin in mLFs. Further, in SAECs, AR inhibition prevented TGFβ1- induced activation of PI3K/AKT/GSK3β pathway but not the phosphorylation of Smad2/3.

Conclusion

Our results demonstrate that allergen-induced airway remodeling is mediated by AR and its inhibition blocks the progression of remodeling via inhibiting TGFβ1-induced Smad-independent and PI3K/AKT/GSK3β-dependent pathway.     

Effects of the adsorption of alkali metal oxides on the electronic,optical, and thermodynamic properties of the Mg<Subscript>12</Subscript>O<Subscript>12</Subscript>nanocage: a density functional theory study

The effect of alkali metal oxides M _n O (M?=?Li, Na, K; n?=?2, 3, 4) on the geometric, electronic, and linear and nonlinear optical properties of the Mg₁₂O₁₂ nanocage was investigated by density-functional-based methods. According to the computational results, these alkali metal oxides are adsorbed on the Mg₁₂O₁₂ nanocage because this adsorption reduces its energy gap. The static first hyperpolarizability (β ₀) of the nanocage is dramatically increased in the presence of the alkali metal oxides, with the greatest increase seen in the presence of the superalkalis (i.e., M₃O; M?=?Li, Na, and K). The highest first hyperpolarizability (β ₀?≈?600,000 a.u.) was calculated for K₃O@Mg₁₂O₁₂, which was considerably more than that for Mg₁₂O₁₂. The thermodynamic properties and relative stabilities of these inorganic compounds are discussed.

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Graphical Abstract Optimized structure and DOS spectrum of K₃O(e@Mg₁₂O₁₂)

     

Exploring Managers’ Perspectives on MNCH Program in Pakistan: A Qualitative Study

Background

Pakistan’s Maternal, Newborn and Child Health (MNCH) Program is faced with multiple challenges in service delivery, financial and logistic management, training and deployment of human resources, and integration within the existing health system. There is a lack of evidence on managerial aspects of the MNCH program management and implementation.

Methods and Findings

This study used qualitative methods to explore the challenges national, provincial and district program managers have faced in implementing a community midwifery program in province of Punjab while also exploring future directions for the program under a devolved health system. While the program had been designed in earnest, the planning lacked critical elements of involving relevant stakeholders in design and implementation, socio-demographic context and capacity of the existing health system. Financial limitations, weak leadership and lack of a political commitment to the problem of maternal health have also had an impact on program implementation.

Conclusions

Our study results suggest that there is a need to re-structure the program while ensuring sustainability and collaboration within the health sector to increase uptake of skilled birth attendance and improve maternal health care in Pakistan.     

A hidden aggregation‐prone structure in the heart of hypoxia inducible factor prolyl hydroxylase

Prolyl hydroxylase domain‐containing protein 2 (PHD2), as one of the most important regulators of angiogenesis and metastasis of cancer cells, is a promising target for cancer therapy drug design. Progressive studies imply that abnormality in PHD2 function may be due to misfolding. Therefore, study of the PHD2 unfolding pathway paves the way for a better understanding of the influence of PHD2 mutations and cancer cell metabolites on the protein folding pathway. We study the unfolding of the PHD2 catalytic domain using differential scanning calorimetry (DSC), fluorescence spectroscopy, and discrete molecular dynamics simulations (DMD). Using computational and experimental techniques, we find that PHD2 undergoes four transitions along the thermal unfolding pathway. To illustrate PHD2 unfolding events in atomic detail, we utilize DMD simulations. Analysis of computational results indicates an intermediate species in the PHD2 unfolding pathway that may enhance aggregation propensity, explaining mutation‐independent PHD2 malfunction. Proteins 2016; 84:611–623. © 2016 Wiley Periodicals, Inc.