90 research outputs found
Nitric Oxide Enhances Desiccation Tolerance of Recalcitrant Antiaris toxicaria Seeds via Protein S-Nitrosylation and Carbonylation
The viability of recalcitrant seeds is lost following stress from either drying or freezing. Reactive oxygen species (ROS) resulting from uncontrolled metabolic activity are likely responsible for seed sensitivity to drying. Nitric oxide (NO) and the ascorbate-glutathione cycle can be used for the detoxification of ROS, but their roles in the seed response to desiccation remain poorly understood. Here, we report that desiccation induces rapid accumulation of H2O2, which blocks recalcitrant Antiaris toxicaria seed germination; however, pretreatment with NO increases the activity of antioxidant ascorbate-glutathione pathway enzymes and metabolites, diminishes H2O2 production and assuages the inhibitory effects of desiccation on seed germination. Desiccation increases the protein carbonylation levels and reduces protein S-nitrosylation of these antioxidant enzymes; these effects can be reversed with NO treatment. Antioxidant protein S-nitrosylation levels can be further increased by the application of S-nitrosoglutathione reductase inhibitors, which further enhances NO-induced seed germination rates after desiccation and reduces desiccation-induced H2O2 accumulation. These findings suggest that NO reinforces recalcitrant seed desiccation tolerance by regulating antioxidant enzyme activities to stabilize H2O2 accumulation at an appropriate concentration. During this process, protein carbonylation and S-nitrosylation patterns are used as a specific molecular switch to control antioxidant enzyme activities
Rapid plant rehydration initiates permanent and adverse changes in the photosynthetic apparatus of triticale
Biotechnological Perspective of Reactive Oxygen Species (ROS)-Mediated Stress Tolerance in Plants
All environmental cues lead to develop secondary stress conditions like osmotic and oxidative stress conditions that reduces average crop yields by more than 50% every year. The univalent reduction of molecular oxygen (O2) in metabolic reactions consequently produces superoxide anions (O2•−) and other reactive oxygen species (ROS) ubiquitously in all compartments of the cell that disturbs redox potential and causes threat to cellular organelles. The production of ROS further increases under stress conditions and especially in combination with high light intensity. Plants have evolved different strategies to minimize the accumulation of excess ROS like avoidance mechanisms such as physiological adaptation, efficient photosystems such as C4 or CAM metabolism and scavenging mechanisms through production of antioxidants and antioxidative enzymes. Ascorbate-glutathione pathway plays an important role in detoxifying excess ROS in plant cells, which includes superoxide dismutase (SOD) and ascorbate peroxidase (APX) in detoxifying O2•−radical and hydrogen peroxide (H2O2) respectively, monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) involved in recycling of reduced substrates such as ascorbate and glutathione. Efficient ROS management is one of the strategies used by tolerant plants to survive and perform cellular activities under stress conditions. The present chapter describes different sites of ROS generation and and their consequences under abiotic stress conditions and also described the approaches to overcome oxidative stress through genomics and genetic engineering
Omalizumab Therapy for Allergic Bronchopulmonary Aspergillosis in Children with Cystic Fibrosis: A Synthesis of Published Evidence
Allergic bronchopulmonary aspergillosis (ABPA) complicating cystic fibrosis (CF) is treated with corticosteroids. Since elevated IgE is a cardinal abnormality, anti-IgE has been used sporadically as adjuvant treatment. In eight case reports, 13 children with CF and ABPA received anti-IgE resulting in improved FEV1, fewer respiratory symptoms and decreased corticosteroid use. Pediatr Pulmonol. 2014; 49:503-507. (c) 2013 Wiley Periodicals, Inc
Sweet cherry fruit cracking: follow-up testing methods and cultivar-metabolic screening
Background
Rain-induced fruit cracking is a major physiological problem in most sweet cherry cultivars. For an in vivo cracking assay, the ‘Christensen method’ (cracking evaluation following fruit immersion in water) is commonly used; however, this test does not adequately simulate environmental conditions. Herein, we have designed and evaluated a cracking protocol, named ‘Waterfall method’, in which fruits are continuously wetted under controlled conditions.
Results
The application of this method alone, or in combination with ‘Christensen method, was shown to be a reliable approach to characterize sweet cherry cracking behavior. Seventeen cherry cultivars were tested for their cracking behavior using both protocols, and primary as well as secondary metabolites identification was performed in skin tissue using a combined GC–MS and UPLC-MS/MS platform. Significant variations of some of the detected metabolites were discovered and important cracking index–metabolite correlations were identified.
Conclusions
We have established an alternative/complementary method of cherry cracking characterization alongside to Christiansen assay
Exhaled NO may predict loss of asthma control: the effect of concomitant allergic rhinitis
Nasal continuous positive airway pressure treatment reduces systemic oxidative stress in patients with severe obstructive sleep apnea syndrome
Objective: To evaluate whether nasal continuous positive airway pressure (nCPAP) reduces oxidative stress in patients with severe obstructive sleep apnea (OSA) syndrome. Materials and methods: Forty-six patients with severe OSA (AHI >= 30) requiring nasal CPAP treatment and 46 controls (subjects without OSA and with mild OSA as defined by all AHI < 15) were enrolled. Oxidative stress was evaluated in blood samples with a commercially available automated spectrophotometric assay (D-ROMs test, Diacron, Grosseto, Italy), Blood samples were collected the evening before (10:00 p.m.) and the morning after (07:00 a.m.) a diagnostic polysomnography. Patients with severe OSA syndrome were Subsequently submitted to a second polysomnography with nasal CPAP titration the following night. Using the same schedule we collected blood samples from the patients the morning after the nCPAP titration and after two months of nCPAP treatment. Results: Patients with severe OSA presented higher levels of oxidative stress than patients with AHI < 15 in the evening and in the morning (357.57 +/- 13.07 UCarr vs. 319.28 +/- 12.66 UCarr, p = 0.038, and 371.83 +/- 12.83 UCarr vs. 328.09 +/- 11.76 UCarr, p = 0.014, respectively). Patients with severe OSA presented a significant reduction the levels of oxidative stress the morning after the nCPAP titration Study (371.83 +/- 12.83 UCarr vs. 298.21 +/- 9.62 UCarr, p = 0.001) and this reduction was further preserved after a period of two months of nCPAP treatment (293.72 +/- 6.55 UCarr, p = 0.001 vs. baseline). Statistically significant correlations were observed between levels of oxidative stress and nocturnal polysomnography (NPSG) markers as oxygen desaturation index (ODI), arousal index (AI), lowest oxygen saturation of hemoglobin, and mean oxygen saturation or hemoglobin. Conclusions: Patients with severe OSA syndrome presented increased systemic oxidative stress. A single night of nCPAP treatment significantly reduced the levels of oxidative stress in patients with severe OSA syndrome, and this reduction was maintained at least after two months of nCPAP treatment. (C) 2007 Elsevier B.V. All rights reserved
Portable exhaled nitric oxide as a screening tool for asthma in young adults during pollen season
Background: The fraction of exhaled NO (FeNO) is valuable for the follow-up of asthmatic patients. However, its usefulness as a screening tool for asthma is not established. Methods: We screened a population of 961 university students with a modified European Community Respiratory Health Survey questionnaire that has been previously used for the screening of respiratory symptoms related to asthma. All subjects with a positive answer to at least one question (n = 149) were submitted to FeNO measurement with a portable nitric oxide analyzer. Subsequently, they were submitted to spirometry and evaluated by a physician blinded to FeNO measurements. Seventy students with no respiratory symptoms served as control subjects. Results: Asthma was diagnosed in 63 subjects, and allergic rhinitis was diagnosed in 57 subjects. Asthmatics presented higher FeNO values than control subjects (median, 20 parts per billion [ppb]; interquartile range, 14 to 31 ppb; vs median, 11 ppb; interquartile range, 7 to 13 ppb, respectively; p 19 ppb presented 85.2% specificity and 52.4% sensitivity for the diagnosis of asthma (area under the curve [AUC], 0.723). The diagnostic performance of FeNO was better in nonsmokers (AUC, 0.805), yet FeNO values > 25 ppb were characterized by specificity > 90% for the diagnosis of asthma both in smokers and in nonsmokers. However, FeNO was not a good marker for the differentiation between asthma and allergic rhinitis. Conclusions: FeNO measurement with a portable analyzer is useful for the screening for asthma in young adults. Significant confounding factors are allergic rhinitis and current smoking
Matrix Metalloproteinases in Respiratory Diseases: From Pathogenesis to Potential Clinical Implications
Matrix metalloproteinases (MMPs) are zinc-endopeptidases responsible for degradation of the extracellular matrix (ECM) components including basement membrane collagen, interstitial collagen, fibronectin, and various proteoglycans, during normal remodeling and repair processes. The turnover and remodeling of ECM must be tightly regulated since excessive or inappropriate expression of MMPs may contribute to the pathogenesis of tissue destructive processes associated with lung inflammation and disease. Despite the fact that our knowledge in the field of MMP biology is rapidly expanding, the role of MMPs in the pathogenesis of lung diseases is still not clear. The aim of the present review is to present the basic principles of MMP biology and, subsequently, to focus on the clinical and experimental evidence related to MMP activity in various lung disorders, including lung cancer, pleural effusions, chronic obstructive pulmonary disease, asthma, acute respiratory distress syndrome and interstitial lung diseases
Study of Greek children and youths with cystic fibrosis identifies immunisation gaps and delays
Aim: Data about immunisation rates in cystic fibrosis (CF) patients are scarce. We estimated the rates and timeliness of immunisations in CF patients aged 0.55–22 years. Methods: We studied 122 subjects at a hospital in Greece in 2014. A standard questionnaire was used to collect data and parents' opinions about immunisations. Results: The complete immunisation rates were 92.6% for diphtheria–tetanus–acellular pertussis-inactivated poliomyelitis-Haemophilus influenzae (DTaP-IPV-Hib), 96.7% for hepatitis A, 97.4% for hepatitis B, 97.4% for measles–mumps–rubella, 85.1% for the varicella zoster virus, 85.1% for the meningococcus C conjugate, 84.3% for the pneumococcus conjugate and 58.9% for the bacillus Calmette-Guérin vaccine. Immunisation rates in youths were 64.4% for DTaP-IPV, 26.8% for the tetravalent meningococcus conjugate vaccine and 54.1% for the human papilloma virus vaccine. In addition, 30.1% received the 23-valent pneumococcal polysaccharide vaccine and 45.6% received annual influenza vaccines. Complete, up-to-date immunisation rates fell from 61.4% at 12 months of age to 14.5% at six and 12 years. All vaccines experienced delays. Most parents believed vaccines were necessary to protect their child's health. Conclusion: Our study of children with CF found immunisation gaps with no catch-up immunisations and these need to be administered at follow-up visits. ©2016 Foundation Acta Pædiatrica. Published by John Wiley & Sons Lt
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