58 research outputs found

    Physiological and biotechnological studies on the microalga Dunaliella, the bacterium Halomonas, and the cyanobacteria Arthrospira and Spirulina.

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    A bacterial isolate and a microalga were identified to the genus level using 16S and 18S rRNA gene sequences respectively and· phylogenetic trees were constructed. The bacterial isolate belonged to the genus Halomonas and it was called Halomonas sp. NAH1, whereas the microalga was confirmed as belonging to the species Dunalie/la salina GGAP 19/30 which was the source of 18S rRNA gene. Glycerol production by three strains of the unicellular microalga Dunalie/la (D. parva 19/9, D. parva 19/10, and D. salina 19/30) was explored. The strains were grown in batch cultures in a range of salinities (0.1 4.0 M NaCI). Both intracellular and extracellular glycerol concentrations were measured. All three strains grew well over the range of salinities with optimum growth for all strains at 0.1 to 0.4 M NaC1. All strains leak significant amounts of glycerol in batch cultures. Significant leakage of glycerol into the growth medium was found to be an intrinsic property of the three strains tested. Two strains of Dunalie/la salina (GGAP 19/18 and 19/30) were grown in batch cultures and aerated with different concentrations of G02. Strain 19/18 accumulated large amounts of ~-carotene under nitrogen limitation whereas the strain 19/30 did not. Halomonas sp. NAH1 grew optimally at 1.0 M NaCI and utilised glucose, glycerol or betaine as the sole source of carbon. Glucose supported the most rapid growth rate. Sensitivity of NAH1 to antibiotics was determined and tetracycline had the most inhibitory effect on growth. The cyanobacteria Arthrospira fusiformis GGAP 1475/8 and Spirulina platensis UTEX LB 2340 were shown to be only slightly halotolerant with optimum growth for S. platensis at 0.1 M NaC1 and for A. fusiformis at 0.5 M NaC1. Phycobiliprotein content was very low in both strains, but very high protein content (92.9% of the dry weight biomass) was obtained for S. platensis. This strain looks very promising for mass cultivation for food and/or feed purposes. Glucosyl-glycerol was found to be the compatible solute in both A. fusiformis and S. platensis

    Association between Paraoxonases Gene Expression and Oxidative Stress in Hepatotoxicity Induced by CCl 4

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    Objectives. The purpose of the study is to evaluate the hepatoprotective effect of rutin in carbon tetrachloride- (CCl4-) induced liver injuries in rat model. Methods. Forty male Wistar albino rats were divided into four groups. Group I was the control group and received dimethyl sulphoxide (DMSO) and olive oil. Group II received rutin. Groups III was treated with CCl4. Group IV was administered rutin after 48 h of CCl4 treatment. Liver enzymes level, lipid profile, lipid peroxidation, and hydrogen peroxide were measured. The genes expression levels were monitored by real time RT-PCR and western blot techniques. Results. CCl4 group showed significant increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST), thiobarbituric acid reactive substances (TBAR), hydrogen peroxide (H2O2), and lipid profile and a significant decrease in glutathione peroxidase (GPx), glutathione S transferase (GST), catalase (CAT), paraoxonase-1 (PON-1), paraoxonase-3 (PON-3), peroxisome proliferator activated receptor delta (PPAR-δ), and ATP-binding cassette transporter 1 (ABAC1) genes expression levels. Interestingly, rutin supplementation completely reversed the biochemical and gene expression levels induced by CCl4 to control values. Conclusion. CCl4 administration causes aberration of genes expression levels in oxidative stress pathway resulting in DNA damage and hepatotoxicity. Rutin causes hepatoprotective effect through enhancing the antioxidant genes

    Downregulation of Oxidative and Nitrosative Apoptotic Signaling by L-Carnitine in Ifosfamide-Induced Fanconi Syndrome Rat Model

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    It is well documented that ifosfamide (IFO) therapy is associated with sever nephropathy in the form of Fanconi syndrome. Although oxidative stress has been reported as a major player in IFO-induced Fanconi syndrome, no mechanism for this effect has been ascertained. Therefore, this study has been initiated to investigate, on gene expression level, the mechanism of IFO-induce nephrotoxicity and those whereby carnitine supplementation attenuates this serious side effect of IFO. To achieve the ultimate goals of this study, adult male rats were assigned to one of four treatment groups, namely, control, L-carnitine, IFO, and IFO plus L-carnitine. Administration of IFO for 5 days significantly increased serum creatinine, blood urea nitrogen (BUN), and total nitrate/nitrite (NOx) production in kidney tissues. In addition, IFO significantly increased mRNA expression of inducible nitric oxide synthase (iNOS), caspase-9, and caspase-3 and significantly decreased expression of glutathione peroxides (GPx), catalase (CAT), and Bcl2 in kidney tissues. Administration of L-carnitine to IFO-treated rats resulted in a complete reversal of the all biochemical and gene expression changes, induced by IFO, to the control values. Data from this study suggest that L-carnitine prevents the development of IFO-induced nephrotoxicity via downregulation of oxidative and nitrosative apoptotic signaling in kidney tissues

    Emerging risks in recycling and waste: Perfluorinated compounds in plastic pellets and nanomaterials in contaminated soil

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    Ponencia presentada en la Final RISKCYCLE conference, titulada "Risk-Based Management of Chemicals and Products in a circular economy at a global scale",celebrada en Dresden (Alemania) el 8 y 8 de mayo de 2012.According to the European Parliament over 1.8 billion tonnes of waste are generated each year in Europe (3.5 tonnes per person) and less than a third of it is recycled. United States produces approximately 200 million tons of garbage each year, according to the Environmental Protection Agency.Peer reviewe

    Detecting early signs of heat and drought stress in Phoenix dactylifera (date palm)

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    Plants adapt to the environment by either long-term genome evolution or by acclimatization processes where the cellular processes and metabolism of the plant are adjusted within the existing potential in the genome. Here we studied the adaptation strategies in date palm, Phoenix dactylifera, under mild heat, drought and combined heat and drought by transcriptomic and metabolomic profiling. In transcriptomics data, combined heat and drought resembled heat response, whereas in metabolomics data it was more similar to drought. In both conditions, soluble carbohydrates, such as fucose, and glucose derivatives, were increased, suggesting a switch to carbohydrate metabolism and cell wall biogenesis. This result is consistent with the evidence from transcriptomics and cis-motif analysis. In addition, transcriptomics data showed transcriptional activation of genes related to reactive oxygen species in all three conditions (drought, heat, and combined heat and drought), suggesting increased activity of enzymatic antioxidant systems in cytosol, chloroplast and peroxisome. Finally, the genes that were differentially expressed in heat and combined heat and drought stresses were significantly enriched for circadian and diurnal rhythm motifs, suggesting new stress avoidance strategies.Peer reviewe

    Evaluation of inhaled nitric oxide (iNO) treatment for moderate-to-severe ARDS in critically ill patients with COVID-19: A multicenter cohort study

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    Background: Inhaled nitric oxide (iNO) is used as rescue therapy in patients with refractory hypoxemia due to severe COVID-19 acute respiratory distress syndrome (ARDS) despite the recommendation against the use of this treatment. To date, the effect of iNO on the clinical outcomes of critically ill COVID-19 patients with moderate-to-severe ARDS remains arguable. Therefore, this study aimed to evaluate the use of iNO in critically ill COVID-19 patients with moderate-to-severe ARDS. Methods: This multicenter, retrospective cohort study included critically ill adult patients with confirmed COVID-19 treated from March 01, 2020, until July 31, 2021. Eligible patients with moderate-to-severe ARDS were subsequently categorized into two groups based on inhaled nitric oxide (iNO) use throughout their ICU stay. The primary endpoint was the improvement in oxygenation parameters 24 h after iNO use. Other outcomes were considered secondary. Propensity score matching (1:2) was used based on the predefined criteria. Results: A total of 1598 patients were screened, and 815 were included based on the eligibility criteria. Among them, 210 patients were matched based on predefined criteria. Oxygenation parameters (PaO2, FiO2 requirement, P/F ratio, oxygenation index) were significantly improved 24 h after iNO administration within a median of six days of ICU admission. However, the risk of 30-day and in-hospital mortality were found to be similar between the two groups (HR: 1.18; 95% CI: 0.77, 1.82; p = 0.45 and HR: 1.40; 95% CI: 0.94, 2.11; p= 0.10, respectively). On the other hand, ventilator-free days (VFDs) were significantly fewer, and ICU and hospital LOS were significantly longer in the iNO group. In addition, patients who received iNO had higher odds of acute kidney injury (AKI) (OR (95% CI): 2.35 (1.30, 4.26), p value = 0.005) and hospital/ventilator-acquired pneumonia (OR (95% CI): 3.2 (1.76, 5.83), p value = 0.001). Conclusion: In critically ill COVID-19 patients with moderate-to-severe ARDS, iNO rescue therapy is associated with improved oxygenation parameters but no mortality benefits. Moreover, iNO use is associated with higher odds of AKI, pneumonia, longer LOS, and fewer VFDs

    Integrative multi‐omics analyses of date palm (Phoenix dactylifera) roots and leaves reveal how the halophyte land plant copes with sea water

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    Date palm (Phoenix dactylifera L.) is able to grow and complete its life cycle while being rooted in highly saline soils. Which of the many well-known salt-tolerance strategies are combined to fine-tune this remarkable resilience is unknown. The precise location, whether in the shoot or the root, where these strategies are employed remains uncertain, leaving us unaware of how the various known salt-tolerance mechanisms are integrated to fine-tune this remarkable resilience. To address this shortcoming, we exposed date palm to a salt stress dose equivalent to seawater for up to 4 weeks and applied integrative multi-omics analyses followed by targeted metabolomics, hormone, and ion analyses. Integration of proteomic into transcriptomic data allowed a view beyond simple correlation, revealing a remarkably high degree of convergence between gene expression and protein abundance. This sheds a clear light on the acclimatization mechanisms employed, which depend on reprogramming of protein biosynthesis. For growth in highly saline habitats, date palm effectively combines various salt-tolerance mechanisms found in both halophytes and glycophytes: “avoidance” by efficient sodium and chloride exclusion at the roots, and “acclimation” by osmotic adjustment, reactive oxygen species scavenging in leaves, and remodeling of the ribosome-associated proteome in salt-exposed root cells. Combined efficiently as in P. dactylifera L., these sets of mechanisms seem to explain the palm's excellent salt stress tolerance

    Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm

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    <p>Abstract</p> <p>Background</p> <p><it>Costus speciosus </it>(Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used<b/>to treat mental disorders.</p> <p>Method</p> <p>Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory <b>Concentration </b>(MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds</p> <p>Results</p> <p>Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of <it>C.speciosus </it>showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 μg/ml against <it>Trichophyton mentagrophytes</it>, 62. μg/ml against <it>T. simii</it>, 31.25 μg/ml against <it>T. rubrum </it>296, 62.5 μg/ml against <it>T. rubrum </it>57, 125 μg/ml against <it>Epidermophyton floccosum</it>, 250 μg/ml against <it>Scopulariopsis </it>sp, 250 μg/ml against <it>Aspergillus niger</it>, 125 μg/ml against <it>Curvulari lunata</it>, 250 μg/ml against <it>Magnaporthe grisea</it>.</p> <p>Conclusion</p> <p>Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.</p

    Stress amongst male teachers in state schools in Saudi Arabia

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    There has been increasing professional and public interest in issues related to occupational stress carried out during the last two decades. While a number of studies have been carried out in developed countries on such issues, few studies have been conducted in Saudi Arabia, particularly in the field of education. This study is therefore important because there has been virtually no research that has focused on teacher stress in the country and no study, to-date, has compared teachers' stress at the primary, intermediate, and secondary school stages. This study therefore aims to fill the research gap and to conduct an investigation into an issue that is currently raising serious concerns in the education field.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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