Since March 2020, Spain (along with many other countries) has been severely affected by the ongoing coronavirus disease 19 (COVID‐19) pandemic caused by the rapid spread of a new virus (severe acute ...respiratory syndrome coronavirus 2; SARS‐CoV‐2). As part of global efforts to improve disease surveillance, we investigated how readily SARS‐CoV‐2 RNA could be detected in environmental samples collected from an isolated rural community in Spain with a high COVID‐19 prevalence (6% of the population of 883 inhabitants). The first diagnosis of COVID‐19‐compatible symptoms in the village was recorded on 3 March 2020, and the last known active case resolved on 5 June 2020. By 15 May, two months after strict movement constraints were imposed (‘lockdown’), and the cumulative number of symptomatic cases had increased to 53. Of those cases, 22 (41%) had been tested and confirmed by RT‐PCR. On 13 May and 5 June, samples were collected from high‐use surfaces and clothes in the homes of 13 confirmed cases, from surfaces in nine public service sites (e.g. supermarket and petrol station) and from the wastewater of the village sewage system. SARS‐CoV‐2 RNA was detected in 7 of 57 (12%) samples, including three households and three public sites. While there is not yet sufficient evidence to recommend environmental surveillance as a standard approach for COVID‐19 epidemiology, environmental surveillance research may contribute to advance knowledge about COVID‐19 by further elucidating virus shedding dynamics and environmental contamination, including the potential identification of animal reservoirs.
Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) still poses a challenge for biomedicine and public health. To advance the development of effective diagnostic, prognostic, and preventive ...interventions, our study focused on high‐throughput antibody binding epitope mapping of the SARS‐CoV‐2 spike RBD protein by IgA, IgM and IgG antibodies in saliva and sera of different cohorts from healthy uninfected individuals to SARS‐CoV‐2‐infected unvaccinated and vaccinated asymptomatic, recovered, nonsevere, and severe patients. Identified candidate diagnostic (455‐LFRKSNLKPFERD‐467), prognostic (395‐VYADSFVIRGDEV‐407‐C‐KLH, 332‐ITNLCPFGEV‐342‐C‐KLH, 352‐AWNRKRI‐358‐C‐KLH, 524‐VCGPKKSTNLVKN‐536‐KLH), and protective (MKLLE‐487‐NCYFPLQSYGFQPTNGVG‐504‐GGGGS‐446‐GGNYNYLYRLFRKSNLKPFERD‐467) epitopes were validated with sera from prevaccine and postvaccine cohorts. The results identified neutralizing epitopes and support that antibody recognition of linear B‐cell epitopes in RBD protein is associated with antibody isotype and disease symptomatology. The findings in asymptomatic individuals suggest a role for anti‐RBD antibodies in the protective response against SARS‐CoV‐2. The possibility of translating results into diagnostic interventions for the early diagnosis of asymptomatic individuals and prognosis of disease severity provides new tools for COVID‐19 surveillance and evaluation of risks in hospitalized patients. These results, together with other approaches, may contribute to the development of new vaccines for the control of COVID‐19 and other coronavirus‐related diseases using a quantum vaccinomics approach through the combination of protective epitopes.
Recognition of linear B‐cell epitopes in SARS‐CoV‐2 Spike protein is associated with antibody isotype and disease symptomatology. Antibody isotype mapping identified reactive immunodominant epitopes in infected individuals from asymptomatic to severe cases. These results may translate into diagnostic and prognostic interventions for COVID‐19 surveillance and development of new vaccines.
The COVID-19 pandemic caused by SARS-CoV-2 challenges the understanding of factors affecting disease progression and severity. The identification of prognostic biomarkers and physiological processes ...associated with disease symptoms is relevant for the development of new diagnostic and therapeutic interventions to contribute to the control of this pandemic. To address this challenge, in this study, we used a quantitative proteomics together with multiple data analysis algorithms to characterize serum protein profiles in five cohorts from healthy to SARS-CoV-2-infected recovered (hospital discharge), nonsevere (hospitalized), and severe at the intensive care unit (ICU) cases with increasing systemic inflammation in comparison with healthy individuals sampled prior to the COVID-19 pandemic. The results showed significantly dysregulated proteins and associated biological processes and disorders associated to COVID-19. These results corroborated previous findings in COVID-19 studies and highlighted how the representation of dysregulated serum proteins and associated BPs increases with COVID-19 disease symptomatology from asymptomatic to severe cases. The analysis was then focused on novel disease processes and biomarkers that were correlated with disease symptomatology. To contribute to translational medicine, results corroborated the predictive value of selected immune-related biomarkers for disease recovery Selenoprotein P (SELENOP) and Serum paraoxonase/arylesterase 1 (PON1), severity Carboxypeptidase B2 (CBP2), and symptomatology Pregnancy zone protein (PZP) using protein-specific ELISA tests. Our results contributed to the characterization of SARS-CoV-2–host molecular interactions with potential contributions to the monitoring and control of this pandemic by using immune-related biomarkers associated with disease symptomatology.
Nitrosative stress in plants Valderrama, Raquel; Corpas, Francisco J.; Carreras, Alfonso ...
FEBS letters,
February 06, 2007, Letnik:
581, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Nitrosative stress has become a usual term in the physiology of nitric oxide in mammalian systems. However, in plants there is much less information on this type of stress. Using olive leaves as ...experimental model, the effect of salinity on the potential induction of nitrosative stress was studied. The enzymatic
l-arginine-dependent production of nitric oxide (NOS activity) was measured by ozone chemiluminiscence. The specific activity of NOS in olive leaves was 0.280
nmol NO
mg
−1 protein
min
−1, and was dependent on
l-arginine, NADPH and calcium. Salt stress (200
mM NaCl) caused an increase of the
l-arginine-dependent production of nitric oxide (NO), total
S-nitrosothiols (RSNO) and number of proteins that underwent tyrosine nitration. Confocal laser scanning microscopy analysis using either specific fluorescent probes for NO and RSNO or antibodies to
S-nitrosoglutathione and 3-nitrotyrosine, showed also a general increase of these reactive nitrogen species (RNS) mainly in the vascular tissue. Taken together, these findings show that in olive leaves salinity induces nitrosative stress, and vascular tissues could play an important role in the redistribution of NO-derived molecules during nitrosative stress.
ABSTRACT
Growth of pea (Pisum sativum L.) plants with 50 µm CdCl2 for 15 d produced a reduction in the number and length of lateral roots, and changes in structure of the principal roots affecting ...the xylem vessels. Cadmium induced a reduction in glutathione (GSH) and ascorbate (ASC) contents, and catalase (CAT), GSH reductase (GR) and guaiacol peroxidase (GPX) activities. CuZn‐superoxide dismutase (SOD) activity was also diminished by the Cd treatment, although Mn‐SOD was slightly increased. CAT and CuZn‐SOD were down‐regulated at transcriptional level, while Mn‐SOD, Fe‐SOD and GR were up‐regulated. Analysis of reactive oxygen species (ROS) and nitric oxide (NO) levels by fluorescence and confocal laser microscopy (CLM) showed an over‐accumulation of O2.− and H2O2, and a reduction in the NO content in lateral and principal roots. ROS overproduction was dependent on changes in intracellular Ca+2 content, and peroxidases and NADPH oxidases were involved. Cadmium also produced an increase in salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) contents. The rise of ET and ROS, and the NO decrease are in accordance with senescence processes induced by Cd, and the increase of JA and SA could regulate the cellular response to cope with damages imposed by cadmium.
We used primary care data to retrospectively describe the entry, spread, and impact of COVID-19 in a remote rural community and the associated risk factors and challenges faced by the healthcare ...team. Generalized linear models were fitted to assess the relationship between age, sex, period, risk group status, symptom duration, post-COVID illness, and disease severity. Social network and cluster analyses were also used. The first six cases, including travel events and a social event in town, contributed to early infection spread. About 351 positive cases were recorded and 6% of patients experienced two COVID-19 episodes in the 2.5-year study period. Five space–time case clusters were identified. One case, linked with the social event, was particularly central in its contact network. The duration of disease symptoms was driven by gender, age, and risk factors. The probability of suffering severe disease increased with symptom duration and decreased over time. About 27% and 23% of individuals presented with residual symptoms and post-COVID illness, respectively. The probability of developing a post-COVID illness increased with age and the duration of COVID-associated symptoms. Carefully registered primary care data may help optimize infection prevention and control efforts and upscale local healthcare capacities in vulnerable rural communities.
NADPH is an important molecule in the redox balance of the cell. In this paper, using olive tissue cultures as a model of the function of the NADPH-generating dehydrogenases in the mechanism of ...oxidative stress induced by severe salinity conditions was studied. When olive (Olea europaea) plants were grown with 200 m smallcapital m NaCl, a 40% reduction in leaf fresh weight was produced. The content of non-enzymatic antioxidants such as ascorbate and glutathione was diminished between 20% to 39%, whereas the H₂O₂ content was increased threefold. In contrast, the analysis of the activity and protein contents of the main antioxidative enzymes showed a significant increase of catalase, superoxide dismutase and glutathione reductase. Overall, these changes strongly suggests that NaCl induces oxidative stress in olive plants. On the other hand, while the content of glucose-6-phosphate was increased almost eightfold in leaves of plants grown under salt stress, the content of NAD(P)H (reduced and oxided forms) did not show significant variations. Under salt stress conditions, the activity and protein contents of the main NADPH-recycling enzymes, glucose-6-phosphate dehydrogenase (G6PDH), isocitrate dehydrogenase (ICDH), malic enzyme (ME) and ferrodoxin-NADP reductase (FNR) showed an enhancement of 30-50%. In leaves of olive plants grown with 200 m smallcapital m NaCl, analysis of G6PDH by immunocytochemistry and confocal laser scanning microscopy showed a general increase of this protein in epidermis, palisade and spongy mesophyll cells. These results indicate that in olive plants, salinity causes reactive oxygen species (ROS)-mediated oxidative stress, and plants respond to this situation by inducing different antioxidative enzymes, especially the NADPH-producing dehydrogenases in order to recycle NADPH necessary for the protection against oxidative damages. These NADP-dehydrogenases appear to be key antioxidative enzymes in olive plants under salt stress conditions.
In the last two years, the coronavirus disease 19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a scientific and social challenge worldwide. ...Vaccines have been the most effective intervention for reducing virus transmission and disease severity. However, genetic virus variants are still circulating among vaccinated individuals with different disease symptomatology. Understanding the protective- or disease-associated mechanisms in vaccinated individuals is relevant to advances in vaccine development and implementation. To address this objective, serum-protein profiles were characterized by quantitative proteomics and data-analysis algorithms in four cohorts of uninfected and SARS-CoV-2-infected vaccinated individuals with asymptomatic, non-severe, and severe disease symptomatology. The results show that immunoglobulins were the most overrepresented proteins in infected cohorts when compared to PCR-negative individuals. The immunoglobulin profile varied between different infected cohorts and correlated with protective- or disease-associated capacity. Overrepresented immunoglobulins in PCR-positive individuals correlated with protective response against SARS-CoV-2, other viruses, and thrombosis in asymptomatic cases. In non-severe cases, correlates of protection against SARS-CoV-2 and HBV together with risk of myasthenia gravis and allergy and autoantibodies were observed. Patients with severe symptoms presented risk for allergy, chronic idiopathic thrombocytopenic purpura, and autoantibodies. The analysis of underrepresented immunoglobulins in PCR-positive compared to PCR-negative individuals identified vaccine-induced protective epitopes in various coronavirus proteins, including the spike receptor-binding domain RBD. Non-immunoglobulin proteins were associated with COVID-19 symptoms and biological processes. These results evidence host-associated differences in response to vaccination and the possibility of improving vaccine efficacy against SARS-CoV-2.
The long-term effects of 50
μM CdCl
2 on the enzymatic and non-enzymatic antioxidative defences of pea (
Pisum sativum L.) plants was studied in terms of activity, protein content and transcripts ...levels. Cadmium caused a reduction of the total glutathione content (GSH+GSSG), with the reduced form of glutathione (GSH) being most affected. The content of ascorbic acid (ASC) was also decreased by the treatment. The transcript levels of catalase (CAT) and monodehydroascorbate reductase (MDHAR) showed a Cd-dependent increase, although CAT activity and its protein content were depressed, which suggests a posttranslational modification of this protein induced by cadmium. Glutathione reductase (GR), and ascorbate peroxidase (APX) did not change significantly, either in activity or accumulation of transcript. However, cadmium treatment provoked a strong reduction in mRNA, protein level and activity of CuZn-superoxide dismutase (SOD), being the most negatively affected antioxidative enzyme, and in less extent of Mn-SOD. Transcriptome analysis of the antioxidative enzymes in leaves of pea plants grown with cadmium and treated with some modulators of the signal transduction cascade suggested that at least Ca
2+ channels, phosphorylation/dephosphorylation processes, nitric oxide, cGMP, salicylic acid (SA) and H
2O
2 were involved in some steps between the cadmium signal and transcript expression of CuZn-SOD, CAT and MDHAR. This indicated the existence of cross-talk between these elements and reactive oxygen species (ROS) metabolism during cadmium stress.
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