Physiological and Genomic Consequences of Intermittent Hypoxia: Selected Contribution: Chemoreflex responses to CO2 before and after an 8-h exposure to hypoxia in humans

The ventilatorysensitivity to CO₂, in hyperoxia, is increased after an 8-hexposure to hypoxia. The purpose of the present study was to determinewhether this increase arises through an increase in peripheral orcentral chemosensitivity. Ten healthy volunteers each underwent 8-hexposures to 1) isocapnic hypoxia, with end-tidalPO₂ (PET_O2) = 55 Torr and end-tidal PCO₂(PET_CO2) = eucapnia; 2)poikilocapnic hypoxia, with PET_O2 = 55 Torr and PET_CO2 = uncontrolled;and 3) air-breathing control. The ventilatory response toCO₂ was measured before and after each exposure with theuse of a multifrequency binary sequence with two levels of PET_CO2: 1.5 and 10 Torr above the normalresting value. PET_O2 was held at 250 Torr.The peripheral (Gp) and the central (Gc) sensitivities were calculatedby fitting the ventilatory data to a two-compartment model. There wereincreases in combined Gp + Gc (26%, P < 0.05),Gp (33%, P < 0.01), and Gc (23%, P = not significant) after exposure to hypoxia. There were no significant differences between isocapnic and poikilocapnic hypoxia. We conclude that sustained hypoxia induces a significant increase inchemosensitivity to CO₂ within the peripheral chemoreflex.

     

The delayed effect of mustard gas on housekeeping gene expression in lung biopsy of chemical injuries

ObjectiveSulfur mustard (SM) was used as a chemical weapon in Iraq-Iran war. Exposed people have major complications in important organs such as pulmonary system. Some studies have shown that SM could affect the expression of endogenous genes and non-housekeeping genes, time dependently. To understand the accurate molecular mechanism of the delayed effect of SM, the identification of the gene expression pattern in these patients is essential. Hence, we have evaluated mRNA expression of four common housekeeping genes (ACTIN, PGK1, β2m, GAPDH) in SM-exposed and non-exposed (control) formalin-fixed, paraffin-embedded (FFPE) human lung tissues.MethodParaffin block of lung biopsy of SM-exposed people (11 cases) and people without exposure to SM as control group (9 cases) have been selected. The mRNA expression of four endogenous control genes has been evaluated by qRT-PCR. The stability value of each gene was calculated by different methods.ResultIt was found that ACTIN mRNA has the highest expression (30.26±2.87) and PGK1 has the lowest standard deviation (SD) (30.885±2.215) between pooled groups. The best correlation was between ACTIN and PGK1 expressions. The M value has shown that ACTIN and then PGK1 are the most stable housekeeping genes among. The results obtained from the GeNorm and NormFinder have indicated that the pair ACTIN- PGK1 is the most suitable choice for endogenous control genes.ConclusionACTIN and PGK1 genes are stable in studied lung tissues and are the better than two other housekeeping genes. In addition, mustard gas does not affect their expression in long term.     

Hilyses®, fermented Saccharomyces cerevisiae, enhances the growth performance and skin non-specific immune parameters in rainbow trout (Oncorhynchus mykiss)

Effects of Hilyses^®, fermented Saccharomyces cerevisiae (S. cerevisiae), on growth, body composition and skin mucus immune components in rainbow trout were quantified. Ninety rainbow trout (105 ± 5 g) were randomly assigned to 2 groups in triplicates and fed dietary Hilyses^® (5 g kg^?1) or control diet without Hilyses^® for 50 days. Results of this study demonstrated that growth performance increased significantly by the dietary yeast supplement; however body composition was not affected in treatment group. At the 45th and 50th day of feeding trial, results of mucus samples demonstrated that yeast supplementation in treatment group significantly promoted enzyme activities, namely lysozyme, protease, alkaline phosphatase and esterase compared to control group. Significant increases were also observed in hemagglutination and antibacterial activity against Yersinia ruckeri in fish fed treatment diet. The present study suggests that fermented S. cerevisiae may effectively promote the growth performance and skin non-specific immune parameters in rainbow trout.     

Potential applications of sheep oocytes as affected by vitrification and in vitro aging

The present study was carried out to investigate how the interactions between aging, vitrification and post-warming interval affect the credibility of sheep MII-oocytes for in vitro fertilization (IVF), intracytoplasmic injection (ICSI), and parthenogenetic activation (PA). According to our results, aged oocytes had significantly higher rates of chromosome and spindle abnormalities compared to young oocytes. However after vitrification-warming, the total rates of these abnormalities were not significantly different between aged and young oocytes. Unvitrified-aged, and vitrified young and aged oocytes had comparable ultrastructural characteristics, whereas they were completely dissimilar in compared with unvitrified-young oocytes. Although mRNA abundance was reduced during vitrification-warming in both aged and young oocytes, the post-warming interval could improve the relative mRNA abundance. Aged oocytes had lower capacity for IVF and ICSI in compared with young oocytes, but had similar pattern for PA process. The vitrification process decreased developmental competence of both aged and young oocytes in compared with young ones, particularly when warmed oocytes were rested for 2 h before IVF, ICSI and PA. The results of the present study showed that in vitro aged oocytes had higher capacity to be used for parthenogenetic studies rather than IVF and ICSI. Furthermore, it was shown that vitrified oocytes had a time-dependent decline in quality and developmental potential. Notably, the speed of this decline was higher in vitrified-young oocytes, indicating that the vitrified oocytes do not require to be rested post warming. Conclusively, the results of this study can be useful in preserving in vitro aged oocytes to provide a valuable and easy access source of oocytes for research purposed studies.     

Effects of sodium alginate elicitation on secondary metabolites and antioxidant activity of safflower genotypes under in vitro salinity stress

The present study was aimed at investigating the effects of different concentrations of sodium alginate (NaAlg) (0.075 and 0.15% (w/v)) on the production of secondary metabolites (SMs) and antioxidant activity of seven safflower genotypes under in vitro salinity stress. The results showed that total phenolic content (TPC), total flavonoids (TFD), total flavonols (TFL), anthocyanin (Ant), total antioxidant capacity (TAC), phenylalanine ammonia-lyase (PAL), catalase (CAT) activity, and lipid peroxidation significantly increased under salinity stress consisting of the concentration of 1.5% (w/v) of NaCl, but callus growth traits decreased. The highest amount of TPC, Ant, and callus growth traits was observed under the elicitation of the sample with the concentration of 0.075(%) NaAlg under salinity stress, but the highest amount for TFD, TFL, CAT, PAL, and TAC was observed under elicitation of the sample with the concentration of 0.15% of NaAlg under salinity stress. This indicated the superiority of NaAlg for elicitation to increase SMs in safflower under salinity stress. Overall, the results showed that genotypes of Mex.22-191 and GE₆₂₉₁₈ could be processed to produce SMs by eliciting NaCl in safflower as an important medicinal plant at cellular level. A positive and significant correlation between CAT and TPC was observed and indicates that phenolic compounds are the major contributors to the antioxidant potential in safflower. This new elicitor introduced new ways to select and exploit the best NaAlg concentration to develop SMs that are of tremendous importance in terms of commercial purposes along with medical features in safflower at cellular level.

     

Comparison of Cytokine Expression in Human PBMCs Stimulated with Normal and Heat-Shocked Lactobacillus plantarum Cell Lysate

Probiotics and Antimicrobial Proteins - Regulation of immune responses is among the beneficial effects of probiotic bacteria on human health. In this study, we aim to investigate the effect of...     

Alteration of gene expression in reactive astrocytes induced by Aβ1-42 using low dose of methamphetamine

Molecular Biology Reports - Alzheimer's disease (AD) is a degenerative brain disorder. Due to the relationship between the functional loss of astrocytes and AD, the present study aims to...     

Cytogentic analysis of human dermal fibroblasts (HDFs) in early and late passages using both karyotyping and comet assay techniques

Human dermal fibroblasts (HDFs) are a potential source of somatic cells for genetic manipulation and tissue engineering. Confirmation of cytogenetic stability of these cells is an essential step for cell nuclear transfer and generation of a suitable and functional induced pluripotent stem cells line. HDF cells were isolated and cultured from human foreskin samples. Cytogenetic stability of these cells was evaluated in early (3–4) and late (10–15) passages using karyotype test and alkaline comet assay techniques. HDF cells in early and late passages showed normal karyotype but by comet assay abnormality and DNA damages in late passages of HDFs were observed. Also, the parameters of alkaline comet assay in early passages of HDFs compared with late passages and positive control groups more significantly were different (p < 0.05). These findings indicate that single-strand breaks or DNA damage after many passages may have occurred in HDF cells. Our results demonstrate that only early passages of HDF cells maintain cytogenetic stability and are good candidates for gene reprogramming. In conclusion, karyotype testing alone can not be used for detection of all signs of cytogenetic abnormality and DNA damages of cells. So, for precise evaluation of DNA damage and cytogenetic instability of fibroblast cells comet assay and karyotype techniques could complement each other.     

Bioceramic-collagen scaffolds loaded with human adipose-tissue derived stem cells for bone tissue engineering

The combination of bioceramics and stem cells has attracted the interest of research community for bone tissue engineering applications. In the present study, a combination of Bio-Oss^® and type 1 collagen gel as scaffold were loaded with human adipose-tissue derived mesenchymal stem cells (AT-MSCs) after isolation and characterization, and the capacity of them for bone regeneration was investigated in rat critical size defects using digital mammography, multi-slice spiral computed tomography imaging and histological analysis. 8 weeks after implantation, no mortality or sign of inflammation was observed in the site of defect. According to the results of imaging analysis, a higher level of bone regeneration was observed in the rats receiving Bio-Oss^®-Gel compared to untreated group. In addition, MSC-seeded Bio-Oss-Gel induced the highest bone reconstruction among all groups. Histological staining confirmed these findings and impressive osseointegration was observed in MSC-seeded Bio-Oss-Gel compared with Bio-Oss-Gel. On the whole, it was demonstrated that combination of AT-MSCs, Bio-Oss and Gel synergistically enhanced bone regeneration and reconstruction and also could serve as an appropriate structure to bone regenerative medicine and tissue engineering application.