Fluvial riparian vegetation (RV) links fluvial and terrestrial ecosystems. It is under significant pressure from anthropogenic activities, and, therefore, the management and restoration of RV are ...increasingly important worldwide. RV has been investigated from different perspectives, so knowledge on its structure and function is widely distributed. An important step forward is to convert existing knowledge into an overview easily accessible—for example, for use in decision-making and management. We aim to provide an overview of ecosystem services provided by RV by adopting a structured approach to identify the ecosystem services, describe their characteristics, and rank the importance of each service. We evaluate each service within four main riparian vegetation types adopting a global perspective to derive a broad concept. Subsequently, we introduce a guided framework for use in RV management based on our structured approach. We also identify knowledge gaps and evaluate the opportunities an ecosystem service approach offers to RV management.
Metformin is a widely used antidiabetic drug whose anticancer effects, mediated by the activation of AMP-activated protein kinase (AMPK) and reduction of mTOR signaling, have become noteworthy. ...Chemotherapy produces genotoxic stress and induces p53 activity, which can cross-talk with AMPK/mTOR pathway. Herein, we investigate whether the combination of metformin and paclitaxel has an effect in cancer cell lines.
Human tumors were xenografted into severe combined immunodeficient (SCID) mice and the cancer cell lines were treated with only paclitaxel or only metformin, or a combination of both drugs. Western blotting, flow cytometry, and immunohistochemistry were then used to characterize the effects of the different treatments.
The results presented herein show that the addition of metformin to paclitaxel leads to quantitative potentialization of molecular signaling through AMPK and a subsequent potent inhibition of the mTOR signaling pathway. Treatment with metformin and paclitaxel resulted in an increase in the number of cells arrested in the G(2)-M phase of the cell cycle, and decreased the tumor growth and increased apoptosis in tumor-bearing mice, when compared with individual drug treatments.
We have provided evidence for a convergence of metformin and paclitaxel induced signaling at the level of AMPK. This mechanism shows how different drugs may cooperate to augment antigrowth signals, and suggests that target activation of AMPK by metformin may be a compelling ally in cancer treatment.
We identified the main changes in serum metabolites associated with severe (n = 46) and mild (n = 19) COVID-19 patients by gas chromatography coupled to mass spectrometry. The modified metabolic ...profiles were associated to an altered amino acid catabolism in hypoxic conditions. Noteworthy, three α-hydroxyl acids of amino acid origin increased with disease severity and correlated with altered oxygen saturation levels and clinical markers of lung damage. We hypothesize that the enzymatic conversion of α-keto-acids to α- hydroxyl-acids helps to maintain NAD recycling in patients with altered oxygen levels, highlighting the potential relevance of amino acid supplementation during SARS-CoV-2 infection.
It is well known that the presence of comorbidities and age-related health issues may hide biochemical and metabolic features triggered by SARS-CoV-2 infection and other diseases associated to ...hypoxia, as they are by themselves chronic inflammatory conditions that may potentially disturb metabolic homeostasis and thereby negatively impact on COVID-19 progression. To unveil the metabolic abnormalities inherent to hypoxemia caused by COVID-19, we here applied gas chromatography coupled to mass spectrometry to analyze the main metabolic changes exhibited by a population of male patients less than 50 years of age with mild/moderate and severe COVID-19 without pre-existing comorbidities known to predispose to life-threatening complications from this infection. Several differences in serum levels of particular metabolites between normal controls and patients with COVID-19 as well as between mild/moderate and severe COVID-19 were identified. These included increased glutamic acid and reduced glutamine, cystine, threonic acid, and proline levels. In particular, using the entire metabolomic fingerprint obtained, we observed that glutamine/glutamate metabolism was associated with disease severity as patients in the severe COVID-19 group presented the lowest and higher serum levels of these amino acids, respectively. These data highlight the hypoxia-derived metabolic alterations provoked by SARS-CoV-2 infection in the absence of pre-existing co-morbidities as well as the value of amino acid metabolism in determining reactive oxygen species recycling pathways, which when impaired may lead to increased oxidation of proteins and cell damage. They also provide insights on new supportive therapies for COVID-19 and other disorders that involve altered redox homeostasis and lower oxygen levels that may lead to better outcomes of disease severity.
SARS-CoV-2 infection represents a global health problem that has affected millions of people. The fine host immune response and its association with the disease course have not yet been fully ...elucidated. Consequently, we analyze circulating B cell subsets and their possible relationship with COVID-19 features and severity.
Using a multiparametric flow cytometric approach, we determined B cell subsets frequencies from 52 COVID-19 patients, grouped them by hierarchical cluster analysis, and correlated their values with clinical data.
The frequency of CD19
B cells is increased in severe COVID-19 compared to mild cases. Specific subset frequencies such as transitional B cell subsets increase in mild/moderate cases but decrease with the severity of the disease. Memory B compartment decreased in severe and critical cases, and antibody-secreting cells are increased according to the severity of the disease. Other non-typical subsets such as double-negative B cells also showed significant changes according to disease severity. Globally, these differences allow us to identify severity-associated patient clusters with specific altered subsets. Finally, respiratory parameters, biomarkers of inflammation, and clinical scores exhibited correlations with some of these subpopulations.
The severity of COVID-19 is accompanied by changes in the B cell subpopulations, either immature or terminally differentiated. Furthermore, the existing relationship of B cell subset frequencies with clinical and laboratory parameters suggest that these lymphocytes could serve as potential biomarkers and even active participants in the adaptive antiviral response mounted against SARS-CoV-2.
Non-valvular atrial fibrillation (NVAF) is the most common cardiac arrhythmia in the general population, and its prevalence increases among patients with chronic kidney disease (CKD) undergoing ...hemodialysis. This population presents high risk of both hemorrhagic and thrombotic events, with little evidence regarding the use of oral anticoagulation treatment (OAT) and multiple complications arising from it; however, stroke prevention with percutaneous left atrial appendage closure (LAAC) is an alternative to be considered. We retrospectively describe the safety and efficacy of percutaneous LAAC in eight patients with NVAF and CKD on hemodialysis during a 12-month follow-up. The mean age was 78.8 years (range 64-86; SD ± 6.7), and seven patients were male. The mean CHA
DS
-VAS
and HAS-BLED scores were high, 4.8 (SD ± 1.5) and 3.8 (SD ± 1.3), respectively. Seventy-five percent of the patients were referred for this intervention due to a history of major bleeding, with gastrointestinal bleeding being the most common type, while the remaining twenty-five percent of the patients were referred because of a high risk of bleeding. The percutaneous LAAC procedure was successfully completed in 100% of the patients, with complete exclusion of the appendage without complications or leaks exceeding 5 mm. There was one death not related to the procedure four days after the intervention. Among the other seven patients, no deaths, cardioembolic events or major bleeding were reported during the follow-up period. In our sample, percutaneous LAAC appears to be a safe and effective alternative to anticoagulation in patients with NVAF and CKD on hemodialysis.
Background: Little is known about the duration of precancerous cervical lesions in relation to human papillomavirus (HPV) infection. We estimated rates of progression and regression and sojourn times ...of cervical squamous intraepithelial lesions (SILs) according to HPV status. Methods: We used data from a longitudinal study of HPV infection and cervical neoplasia in São Paulo, Brazil. Cervical specimens were taken from 2404 women for Pap cytology and polymerase chain reaction–based HPV testing every 4–6 months over a period of 8 years. We used actuarial and non-actuarial analyses to measure time to and rates of lesion progression and regression according to status and type of HPV infection. Results: During follow-up, 118 low-grade SIL (LSIL), 24 high-grade SIL (HSIL), and 173 atypical squamous cells of undetermined significance (ASCUS) events were detected. Mean time to progression from ASCUS to LSIL or worse and from LSIL to HSIL or worse was shorter in women with oncogenic HPV types than in women with no HPV infection (mean times for ASCUS progression were 67.0 and 88.0 months, respectively, in women with oncogenic HPV and no HPV, difference = 21.0 months, 95% confidence interval CI = 11.3 to 30.7 months; mean times for LSIL progression were 73.3 and 83.5 months, respectively, difference = 10.2 months, 95% CI = –0.15 to 20.6 months). Half of the LSILs regressed to normal or ASCUS within 6 months. Mean times for regression from ASCUS to normal, from LSIL to ASCUS or normal, and from HSIL/cervical intraepithelial neoplasia 2 to ASCUS or normal were longer for women with oncogenic HPV types (16.8 months, 95% CI = 7.5 to 26.2 months; 13.8 months, 95% CI = 8.8 to 18.7 months; and 17.1 months, 95% CI = 4.1 to 30.1 months, respectively) than for women with non-oncogenic HPV types (7.7 months, 95% CI = 5.2 to 10.2 months; 7.8 months, 95% CI = 5.3 to 10.2 months; 8.9 months, 95% CI = 3.3 to 14.6 months) or for women with no HPV infection (7.6 months, 95% CI = 6.9 to 8.4 months; 7.6 months, 95% CI = 6.4 to 8.7 months; and 7.0 months, 95% CI = 5.0 to 8.9 months, respectively). Conclusion: Precursor lesions of the cervix persist longer and progress more quickly in women with oncogenic HPV infections than in women with non-oncogenic infections or without HPV. Testing cervical lesions for oncogenic HPVs may help identify those that are likely to progress rapidly.
Wood-feeding termites effectively degrade plant biomass through enzymatic degradation. Despite their high efficiencies, however, individual glycoside hydrolases isolated from termites and their ...symbionts exhibit anomalously low effectiveness in lignocellulose degradation, suggesting hereto unknown enzymatic activities in their digestome. Herein, we demonstrate that an ancient redox-active enzyme encoded by the lower termite Coptotermes gestroi , a Cu/Zn superoxide dismutase ( Cg SOD-1), plays a previously unknown role in plant biomass degradation. We show that Cg SOD-1 transcripts and peptides are up-regulated in response to an increased level of lignocellulose recalcitrance and that Cg SOD-1 localizes in the lumen of the fore- and midguts of C. gestroi together with termite main cellulase, Cg EG-1-GH9. Cg SOD-1 boosts the saccharification of polysaccharides by Cg EG-1-GH9. We show that the boosting effect of C g SOD-1 involves an oxidative mechanism of action in which Cg SOD-1 generates reactive oxygen species that subsequently cleave the polysaccharide. SOD-type enzymes constitute a new addition to the growing family of oxidases, ones which are up-regulated when exposed to recalcitrant polysaccharides, and that are used by Nature for biomass degradation.
A new species of toxic benthic dinoflagellate is described based on laboratory cultures isolated from two locations from Brazil, Rio de Janeiro and Bahia. The morphology was studied with SEM and LM. ...Cells are elliptical in right thecal view and flat. They are 37–44μm long and 29–36μm wide. The right thecal plate has a V shaped indentation where six platelets can be identified. The thecal surface of both thecal plates is smooth and has round or kidney shaped and uniformly distributed pores except in the central area of the cell, and a line of marginal pores. Some cells present an elongated depression on the central area of the apical part of the right thecal plate. Prorocentrum caipirignum is similar to Prorocentrum lima in its morphology, but can be differentiated by the general cell shape, being elliptical while P. lima is ovoid. In the phylogenetic trees based on ITS and LSU rDNA sequences, the P. caipirignum clade appears close to the clades of P. lima and Prorocentrum hoffmannianum. The Brazilian strains of P. caipirignum formed a clade with strains from Cuba, Hainan Island and Malaysia and it is therefore likely that this new species has a broad tropical distribution. Prorocentrum caipirignum is a toxic species that produces okadaic acid and the fast acting toxin prorocentrolide.
The toxin profile and hemolytic activity of a strain of Ostreopsis cf. ovata (UFBA013) isolated from Todos os Santos Bay (northeastern Brazil) were evaluated under different levels of N and P. ...Phylogenetic analyses based on ITS rDNA region (ITS1-5.8S-ITS2) placed UFBA013 within the Atlantic/Mediterranean/Pacific clade of O. cf. ovata. Growth experiments were conducted in f/2 medium modified by adding N and P (P: 0–36 μM; N: 0–882 μM). The growth kinetics was adequately described by logistic equations. The best growth (highest Gm) was recorded under levels of N/P = 0/18, 129/5 and 441/36, while one of the lowest Gm was obtained under P-depletion. The maximum and specific maximum growth rates (as vm; cells mL−1 d−1 and μm; d−1) were achieved with N limitation (N/P = 441/36) and P-limitation/depletion (753/5.3 and 441/0) and are the highest values reported in the literature, most similar to isolates from Pacific and Mediterranean areas. The control experiment (N/P = 441/18) also yielded similar values to those from some Mediterranean isolates, but higher than formerly reported for Brazilian isolates. In all conditions assayed, no palytoxin (PLTX) was detected. The ovatoxins (OVTXs) a, b, c, d and e did not show significant differences in cell quota between exponential and stationary phases. A significant relationship was detected between OVTXs concentration and hemolytic activity.
•Nutrient influences on cell growth and toxin production of O. cf. ovata.•ITS rDNA phylogeny placed tropical O. cf. ovata in Atlantic/Med/Pacific clade.•LC-HRMS analyses revealed the presence of OVXTs -a to -e and absence of PLTX.•Growth rates affected by nutrient conditions but no clear trends in toxins.
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