Identification of novel biomarkers in the early diagnosis of malignant melanoma by untargeted liquid chromatography coupled to high-resolution mass spectrometry-based metabolomics: a pilot study.

BACKGROUND: Malignant melanoma (MM) is a highly aggressive form of skin cancer whose incidence continues to rise worldwide. If diagnosed at an early stage, it has an excellent prognosis, but mortality increases significantly at advanced stages after distant spread. Unfortunately, early detection of aggressive melanoma remains a challenge. OBJECTIVES: To identify novel blood-circulating biomarkers that may be useful in the diagnosis of MM to guide patient counselling and appropriate disease management. METHODS: In this study, 105 serum samples from 26 healthy patients and 79 with MM were analysed using an untargeted approach by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to compare the metabolomic profiles of both conditions. Resulting data were subjected to both univariate and multivariate statistical analysis to select robust biomarkers. The classification model obtained from this analysis was further validated with an independent cohort of 12 patients with stage I MM. RESULTS: We successfully identified several lipidic metabolites differentially expressed in patients with stage I MM vs. healthy controls. Three of these metabolites were used to develop a classification model, which exhibited exceptional precision (0.92) and accuracy (0.94) when validated on an independent sample. CONCLUSIONS: These results demonstrate that metabolomics using LC-HRMS is a powerful tool to identify and quantify metabolites in bodily fluids that could serve as potential early diagnostic markers for MM.

Melanoma is a type of skin cancer that can be deadly if it is not detected at an early stage. Unfortunately, the early detection of melanoma is challenging. Our team has developed a model that could be used to predict whether a person has stage I malignant melanoma based on blood serum analysis. The model was trained on data from a group of people with melanoma and it was found to be accurate in predicting melanoma at an early stage. This means that the model could be used to identify people who have skin cancer before it progresses and becomes more complicated to treat. Although the researchers recommend that further studies are conducted to validate the model in a larger population of people, this research could help with the early diagnosis of melanoma and work toward improving survival rates.

Unveiling the bioactive potential of Actinomycetota from the Tagus River estuary.

The increase in global travel and the incorrect and excessive use of antibiotics has led to an unprecedented rise in antibiotic resistance in bacterial and fungal populations. To overcome these problems, novel bioactive natural products must be discovered, which may be found in underexplored environments, such as estuarine habitats. In the present work, estuarine actinomycetotal strains were isolated with conventional and iChip techniques from the Tagus estuary in Alcochete, Portugal, and analysed for different antimicrobial bioactivities. Extracts were produced from the isolated cultures and tested for bioactivity against Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Aspergillus fumigatus ATCC 240305, Candida albicans ATCC 10231 and Trichophyton rubrum FF5. Furthermore, bioactive extracts were subjected to dereplication by high-performance liquid chromatography (HPLC) and high-resolution mass spectrometry (HRMS) to putatively identify their chemical components. In total, 105 isolates belonging to 3 genera were obtained. One which was isolated, MTZ3.1 T, represents a described novel taxon for which the name Streptomyces meridianus was proposed. Regarding the bioactivity testing, extracts from 12 strains proved to be active against S. aureus, 2 against E. coli, 4 against A. fumigatus, 3 against C. albicans and 10 against T. rubrum. Dereplication of bioactive extracts showed the presence of 28 known bioactive molecules, 35 hits have one or more possible matches in the DNP and 18 undescribed ones. These results showed that the isolated bacteria might be the source of new bioactive natural products.

Uncovering the biotechnological capacity of marine and brackish water Planctomycetota.

An appealing strategy for finding novel bioactive molecules in Nature consists in exploring underrepresented and -studied microorganisms. Here, we investigated the antimicrobial and tumoral anti-proliferative bioactivities of twenty-three marine and estuarine bacteria of the fascinating phylum Planctomycetota. This was achieved through extraction of compounds produced by the Planctomycetota cultured in oligotrophic medium followed by an antimicrobial screening against ten relevant human pathogens including Gram-positive and Gram-negative bacteria, and fungi. Cytotoxic effects of the extracts were also evaluated against five tumoral cell lines. Moderate to potent activities were obtained against Enterococcus faecalis, methicillin-sensitive and methicillin-resistant Staphylococcus aureus and vancomycin-sensitive and vancomycin-resistant Enterococcus faecium. Anti-fungal effects were observed against Trichophyton rubrum, Candida albicans and Aspergillus fumigatus. The highest cytotoxic effects were observed against human breast, pancreas and melanoma tumoral cell lines. Novipirellula caenicola and Rhodopirellula spp. strains displayed the widest spectrum of bioactivities while Rubinisphaera margarita ICM_H10T affected all Gram-positive bacteria tested. LC-HRMS analysis of the extracts did not reveal the presence of any known bioactive natural product, suggesting that the observed activities are most likely caused by novel molecules, that need identification. In summary, we expanded the scope of planctomycetal species investigated for bioactivities and demonstrated that various strains are promising sources of novel bioactive compounds, which reenforces the potential biotechnological prospects offered by Planctomycetota.

The use of the eye-fixation-related potential to investigate visual perception in professional domains with high attentional demand: a literature review.

INTRODUCTION: Visual attention is a cognitive skill related to visual perception and neural activity, and also moderated by expertise, in time-constrained professional domains (e.g., aviation, driving, sport, surgery). However, the contribution of both perceptual and neural processes on performance has been studied separately in the literature. DEVELOPMENT: We defend an integration of visual and neural signals to offer a more complete picture of the visual attention displayed by professionals of different skill levels when performing free-viewing tasks. Specifically, we propose to zoom the analysis in data related to the quiet eye and P300 component jointly, as a novel signal processing approach to evaluate professionals' visual attention. CONCLUSION: This review highlights the advantages of using portable eye trackers and electroencephalogram systems altogether, as a promising technique for a better understanding of early cognitive components related to attentional processes. Altogether, the eye-fixation-related potentials method may provide a better understanding of the cognitive mechanisms employed by the participants in natural settings, revealing what visual information is of interest for participants and distinguishing the neural bases of visual attention between targets and non-targets whenever they perceive a stimulus during free viewing experiments.

Cellulamides: A New Family of Marine-Sourced Linear Peptides from the Underexplored Cellulosimicrobium Genus.

Bioprospecting the secondary metabolism of underexplored Actinomycetota taxa is a prolific route to uncover novel chemistry. In this work, we report the isolation, structure elucidation, and bioactivity screening of cellulamides A and B (1 and 2), two novel linear peptides obtained from the culture of the macroalga-associated Cellulosimicrobium funkei CT-R177. The host of this microorganism, the Chlorophyta Codium tomentosum, was collected in the northern Portuguese coast and, in the scope of a bioprospecting study focused on its associated actinobacterial community, strain CT-R177 was isolated, taxonomically identified, and screened for the production of antimicrobial and anticancer compounds. Dereplication of a crude extract of this strain using LC-HRMS(/MS) analysis unveiled a putative novel natural product, cellulamide A (1), that was isolated following mass spectrometry-guided fractionation. An additional analog, cellulamide B (2) was obtained during the chromatographic process and chemically characterized. The chemical structures of the novel linear peptides, including their absolute configurations, were elucidated using a combination of HRMS, 1D/2D NMR spectroscopy, and Marfey's analysis. Cellulamide A (1) was subjected to a set of bioactivity screenings, but no significant biological activity was observed. The cellulamides represent the first family of natural products reported from the Actinomycetota genus Cellulosimicrobium, showcasing not only the potential of less-explored taxa but also of host-associated marine strains for novel chemistry discovery.

Unearthing a Cryptic Biosynthetic Gene Cluster for the Piperazic Acid-Bearing Depsipeptide Diperamycin in the Ant-Dweller Streptomyces sp. CS113.

Piperazic acid is a cyclic nonproteinogenic amino acid that contains a hydrazine N-N bond formed by a piperazate synthase (KtzT-like). This amino acid, found in bioactive natural products synthesized by non-ribosomal peptide synthetases (NRPSs), confers conformational constraint to peptides, an important feature for their biological activities. Genome mining of Streptomyces strains has been revealed as a strategy to identify biosynthetic gene clusters (BGCs) for potentially active compounds. Moreover, the isolation of new strains from underexplored habitats or associated with other organisms has allowed to uncover new BGCs for unknown compounds. The in-house "Carlos Sialer (CS)" strain collection consists of seventy-one Streptomyces strains isolated from the cuticle of leaf-cutting ants of the tribe Attini. Genomes from twelve of these strains have been sequenced and mined using bioinformatics tools, highlighting their potential to encode secondary metabolites. In this work, we have screened in silico those genomes, using KtzT as a hook to identify BGCs encoding piperazic acid-containing compounds. This resulted in uncovering the new BGC dpn in Streptomyces sp. CS113, which encodes the biosynthesis of the hybrid polyketide-depsipeptide diperamycin. Analysis of the diperamycin polyketide synthase (PKS) and NRPS reveals their functional similarity to those from the aurantimycin A biosynthetic pathway. Experimental proof linking the dpn BGC to its encoded compound was achieved by determining the growth conditions for the expression of the cluster and by inactivating the NRPS encoding gene dpnS2 and the piperazate synthase gene dpnZ. The identity of diperamycin was confirmed by High-Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR) and by analysis of the domain composition of modules from the DpnP PKS and DpnS NRPS. The identification of the dpn BGC expands the number of BGCs that have been confirmed to encode the relatively scarcely represented BGCs for depsipeptides of the azinothricin family of compounds and will facilitate the generation of new-to-nature analogues by combinatorial biosynthesis.

Predicting ICU Mortality in Acute Respiratory Distress Syndrome Patients Using Machine Learning: The Predicting Outcome and STratifiCation of severity in ARDS (POSTCARDS) Study.

OBJECTIVES: To assess the value of machine learning approaches in the development of a multivariable model for early prediction of ICU death in patients with acute respiratory distress syndrome (ARDS). DESIGN: A development, testing, and external validation study using clinical data from four prospective, multicenter, observational cohorts. SETTING: A network of multidisciplinary ICUs. PATIENTS: A total of 1,303 patients with moderate-to-severe ARDS managed with lung-protective ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We developed and tested prediction models in 1,000 ARDS patients. We performed logistic regression analysis following variable selection by a genetic algorithm, random forest and extreme gradient boosting machine learning techniques. Potential predictors included demographics, comorbidities, ventilatory and oxygenation descriptors, and extrapulmonary organ failures. Risk modeling identified some major prognostic factors for ICU mortality, including age, cancer, immunosuppression, Pa o2 /F io2 , inspiratory plateau pressure, and number of extrapulmonary organ failures. Together, these characteristics contained most of the prognostic information in the first 24 hours to predict ICU mortality. Performance with machine learning methods was similar to logistic regression (area under the receiver operating characteristic curve [AUC], 0.87; 95% CI, 0.82-0.91). External validation in an independent cohort of 303 ARDS patients confirmed that the performance of the model was similar to a logistic regression model (AUC, 0.91; 95% CI, 0.87-0.94). CONCLUSIONS: Both machine learning and traditional methods lead to promising models to predict ICU death in moderate/severe ARDS patients. More research is needed to identify markers for severity beyond clinical determinants, such as demographics, comorbidities, lung mechanics, oxygenation, and extrapulmonary organ failure to guide patient management.

A blood microRNA classifier for the prediction of ICU mortality in COVID-19 patients: a multicenter validation study.

BACKGROUND: The identification of critically ill COVID-19 patients at risk of fatal outcomes remains a challenge. Here, we first validated candidate microRNAs (miRNAs) as biomarkers for clinical decision-making in critically ill patients. Second, we constructed a blood miRNA classifier for the early prediction of adverse outcomes in the ICU. METHODS: This was a multicenter, observational and retrospective/prospective study including 503 critically ill patients admitted to the ICU from 19 hospitals. qPCR assays were performed in plasma samples collected within the first 48 h upon admission. A 16-miRNA panel was designed based on recently published data from our group. RESULTS: Nine miRNAs were validated as biomarkers of all-cause in-ICU mortality in the independent cohort of critically ill patients (FDR < 0.05). Cox regression analysis revealed that low expression levels of eight miRNAs were associated with a higher risk of death (HR from 1.56 to 2.61). LASSO regression for variable selection was used to construct a miRNA classifier. A 4-blood miRNA signature composed of miR-16-5p, miR-192-5p, miR-323a-3p and miR-451a predicts the risk of all-cause in-ICU mortality (HR 2.5). Kaplan‒Meier analysis confirmed these findings. The miRNA signature provides a significant increase in the prognostic capacity of conventional scores, APACHE-II (C-index 0.71, DeLong test p-value 0.055) and SOFA (C-index 0.67, DeLong test p-value 0.001), and a risk model based on clinical predictors (C-index 0.74, DeLong test-p-value 0.035). For 28-day and 90-day mortality, the classifier also improved the prognostic value of APACHE-II, SOFA and the clinical model. The association between the classifier and mortality persisted even after multivariable adjustment. The functional analysis reported biological pathways involved in SARS-CoV infection and inflammatory, fibrotic and transcriptional pathways. CONCLUSIONS: A blood miRNA classifier improves the early prediction of fatal outcomes in critically ill COVID-19 patients.

Depression and anxiety in systemic lupus erythematosus: A case-control study on prevalence and associated factors in a single-center cohort.

OBJECTIVES: To evaluate the prevalence of self-perceived depression and anxiety in patients with systemic lupus erythematosus (SLE) and to explore associated factors. METHODS: Cross-sectional study of unselected patients with SLE (ACR-97 criteria) and controls with chronic inflammatory rheumatic diseases. Both completed the Hospital Anxiety and Depression Scale (HADS). Demographic and clinical characteristics, comorbidity, and treatments were collected, and a multivariate analysis was performed to explore factors associated with depression and anxiety in SLE. RESULTS: The study population comprised 172 patients and 215 controls. Women accounted for 93% of the patients with SLE. Fibromyalgia was recorded in 12.8% and a history of depression in 17%. According to HADS, 37.2% fulfilled the diagnostic criteria for depression and 58.7% those for anxiety; prevalence was similar in the controls (32.6% and 55.1%, respectively). Up to a third of patients with self-perceived depression were not receiving antidepressants. There was no concordance between a previous history of depression and current depression. In the multivariate model, current depression was associated with single marital status (OR 2.69; 95% CI: 1.17-6.42; p = .022), fibromyalgia (7.69; 2.35-30.72; p = .001), smoking (3.12; 1.24-8.07; p = .016), severity of SLE (0.76; 0.6-0.94; p = .016), and organ damage (1.27; 1.01-1.61; p = .042). Current anxiety was only associated with fibromyalgia (3.97; 1.21-17.98; p = .036). CONCLUSIONS: Depression and anxiety are most likely underdiagnosed in SLE. Prevalence appears to be similar to that of other chronic inflammatory rheumatic diseases. Anxiety is associated with fibromyalgia, while depression is also associated with single marital status, smoking, organ damage, and severity of SLE.

New Phocoenamicin and Maklamicin Analogues from Cultures of Three Marine-Derived Micromonospora Strains.

Antimicrobial resistance can be considered a hidden global pandemic and research must be reinforced for the discovery of new antibiotics. The spirotetronate class of polyketides, with more than 100 bioactive compounds described to date, has recently grown with the discovery of phocoenamicins, compounds displaying different antibiotic activities. Three marine Micromonospora strains (CA-214671, CA-214658 and CA-218877), identified as phocoenamicins producers, were chosen to scale up their production and LC/HRMS analyses proved that EtOAc extracts from their culture broths produce several structurally related compounds not disclosed before. Herein, we report the production, isolation and structural elucidation of two new phocoenamicins, phocoenamicins D and E (1-2), along with the known phocoenamicin, phocoenamicins B and C (3-5), as well as maklamicin (7) and maklamicin B (6), the latter being reported for the first time as a natural product. All the isolated compounds were tested against various human pathogens and revealed diverse strong to negligible activity against methicillin-resistant Staphylococcus aureus, Mycobacterium tuberculosis H37Ra, Enterococcus faecium and Enterococcus faecalis. Their cell viability was also evaluated against the human liver adenocarcinoma cell line (Hep G2), demonstrating weak or no cytotoxicity. Lastly, the safety of the major compounds obtained, phocoenamicin (3), phocoenamicin B (4) and maklamicin (7), was tested against zebrafish eleuthero embryos and all of them displayed no toxicity up to a concentration of 25 µM.

Interactions of Different Streptomyces Species and Myxococcus xanthus Affect Myxococcus Development and Induce the Production of DK-Xanthenes.

The co-culturing of microorganisms is a well-known strategy to study microbial interactions in the laboratory. This approach facilitates the identification of new signals and molecules produced by one species that affects other species' behavior. In this work, we have studied the effects of the interaction of nine Streptomyces species (S. albidoflavus, S. ambofaciens, S. argillaceus, S. griseus, S. lividans, S. olivaceus, S. parvulus, S. peucetius, and S. rochei) with the predator bacteria Myxococcus xanthus, five of which (S. albidoflavus, S. griseus, S. lividans, S. olivaceus, and S. argillaceus) induce mound formation of M. xanthus on complex media (Casitone Yeast extract (CYE) and Casitone tris (CTT); media on which M. xanthus does not form these aggregates under normal culture conditions. An in-depth study on S. griseus-M. xanthus interactions (the Streptomyces strain producing the strongest effect) has allowed the identification of two siderophores produced by S. griseus, demethylenenocardamine and nocardamine, responsible for this grouping effect over M. xanthus. Experiments using pure commercial nocardamine and different concentrations of FeSO4 show that iron depletion is responsible for the behavior of M. xanthus. Additionally, it was found that molecules, smaller than 3 kDa, produced by S. peucetius can induce the production of DK-xanthenes by M. xanthus.

Uncovering the Cryptic Gene Cluster ahb for 3-amino-4-hydroxybenzoate Derived Ahbamycins, by Searching SARP Regulator Encoding Genes in the Streptomyces argillaceus Genome.

Genome mining using standard bioinformatics tools has allowed for the uncovering of hidden biosynthesis gene clusters for specialized metabolites in Streptomyces genomes. In this work, we have used an alternative approach consisting in seeking "Streptomyces Antibiotic Regulatory Proteins" (SARP) encoding genes and analyzing their surrounding DNA region to unearth cryptic gene clusters that cannot be identified using standard bioinformatics tools. This strategy has allowed the unveiling of the new ahb cluster in Streptomyces argillaceus, which had not been retrieved before using antiSMASH. The ahb cluster is highly preserved in other Streptomyces strains, which suggests a role for their encoding compounds in specific environmental conditions. By combining overexpression of three regulatory genes and generation of different mutants, we were able to activate the ahb cluster, and to identify and chemically characterize the encoded compounds that we have named ahbamycins (AHBs). These constitute a new family of metabolites derived from 3-amino-4-hydroxybenzoate (3,4-AHBA) known for having antibiotic and antitumor activity. Additionally, by overexpressing three genes of the cluster (ahbH, ahbI, and ahbL2) for the synthesis and activation of 3,4-AHBA, a new hybrid compound, AHB18, was identified which had been produced from a metabolic crosstalk between the AHB and the argimycin P pathways. The identification of this new BGC opens the possibility to generate new compounds by combinatorial biosynthesis.

Analysis of ANRIL Isoforms and Key Genes in Patients with Severe Coronary Artery Disease.

ANRIL (Antisense Noncoding RNA in the INK4 Locus), also named CDKN2B-AS1, is a long non-coding RNA with outstanding functions that regulates genes involved in atherosclerosis development. ANRIL genotypes and the expression of linear and circular isoforms have been associated with coronary artery disease (CAD). The CDKN2A and the CDKN2B genes at the CDKN2A/B locus encode the Cyclin-Dependent Kinase inhibitor protein (CDKI) p16INK4a and the p53 regulatory protein p14ARF, which are involved in cell cycle regulation, aging, senescence, and apoptosis. Abnormal ANRIL expression regulates vascular endothelial growth factor (VEGF) gene expression, and upregulated Vascular Endothelial Growth Factor (VEGF) promotes angiogenesis by activating the NF-κB signaling pathway. Here, we explored associations between determinations of the linear, circular, and linear-to-circular ANRIL gene expression ratio, CDKN2A, VEGF and its receptor kinase insert domain-containing receptor (KDR) and cardiovascular risk factors and all-cause mortality in high-risk coronary patients before they undergo coronary artery bypass grafting surgery (CABG). We found that the expression of ANRIL isoforms may help in the prediction of CAD outcomes. Linear isoforms were correlated with a worse cardiovascular risk profile while the expression of circular isoforms of ANRIL correlated with a decrease in oxidative stress. However, the determination of the linear versus circular ratio of ANRIL did not report additional information to that determined by the evaluation of individual isoforms. Although the expressions of the VEFG and KDR genes correlated with a decrease in oxidative stress, in binary logistic regression analysis it was observed that only the expression of linear isoforms of ANRIL and VEGF significantly contributed to the prediction of the number of surgical revascularizations.

Madurastatins with Imidazolidinone Rings: Natural Products or Side-Reaction Products from Extraction Solvents?

Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our search for new potential antiparasitic metabolites from natural sources, we studied the acetone extracts from a culture of Actinomadura sp. CA-135719. The LC/HRMS analysis of this extract identified the presence of the known madurastatins C1 (1), D1 (4), and D2 (5) together with additional members of the family that were identified as the new madurastatins H2 (2) and 33-epi-D1 (3) after isolation and spectroscopic analysis. The planar structures of the new compounds were established by HRMS, ESI-qTOF-MS/MS, and 1D and 2D NMR data, and their absolute configuration was proposed using Marfey's and bioinformatic analyses of the biosynthetic gene cluster (BGC). A revision of the absolute configuration of madurastatins D1 and D2 is proposed. Additionally, madurastatins containing imidazolidinone rings are proved to be artifacts originating during acetone extraction of the bacterial cultures.

Patients with severe mental illness and hepatitis C virus infection benefit from new pangenotypic direct-acting antivirals: Results of a literature review.

INTRODUCTION: Hepatitis C virus (HCV) infection is a global health problem that can results in cirrhosis, hepatocellular carcinoma and even death. HCV infection is 3-20-fold more prevalent among patients with versus without severe mental illness (SMI), such as major depressive disorder, personality disorder, bipolar disorder and schizophrenia. Treatment options for HCV were formerly based on pegylated interferon alpha, which is associated with neuropsychiatric adverse events, and this contributed to the exclusion of patients with SMI from HCV treatment, elimination programmes, and clinical trials. Moreover, the assumption of poor adherence, scant access to healthcare and the stigma and vulnerability of this population emerged as barriers and contributed to the low rates of treatment and efficacy. METHODS: This paper reviews the literature published between December 2010 and December 2020 exploring the epidemiology of HCV in patients with SMI, and vice versa, the effect of HCV infection, barriers to the management of illness in these patients, and benefits of new therapeutic options with pangenotypic direct antiviral agents (DAAs). RESULTS: The approval of DAAs has changed the paradigm of HCV infection treatment. DAAs have proven to be an equally efficacious and safe option that improves quality of life (QoL) in patients SMI. CONCLUSIONS: Knowledge of the consequences of the HCV infection and the benefits of treatment with new pangenotypic DAAs among psychiatrists can increase screening, referral and treatment of HCV infection in patients with SMI.

High SARS-CoV-2 Viral Load and Low CCL5 Expression Levels in the Upper Respiratory Tract Are Associated With COVID-19 Severity.

Mucosal immune response in the upper respiratory tract is crucial for initial control of viral replication, clearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and progression of coronavirus disease 2019 (COVID-19). We analyzed SARS-CoV-2 RNA load and expression of selected immune genes in the upper respiratory tract (nasopharynx) of 255 SARS-CoV-2-infected patients and evaluated their association with severe COVID-19. SARS-CoV-2 replication in nasopharyngeal mucosa induces expression of several innate immune genes. High SARS-CoV-2 viral load and low CCL5 expression levels were associated with intensive care unit admission or death, although CCL5 was the best predictor of COVID-19 severity.

Validation of thrombotic risk factors in 1381 patients with essential thrombocythaemia: A multicentre retrospective real-life study.

Thrombosis and haemorrhage are frequent in patients with essential thrombocythaemia (ET). The 2016 revised International Prognostic Score for Thrombosis in Essential Thrombocythaemia-thrombosis (r-IPSET-t) score stratifies patients into very-low- (VLR), low- (LR), intermediate- (IR) and high-risk (HR) groups. We validated the r-IPSET-t in the biggest population of patients with ET (n = 1381) to date and found it to be a better fit than the earlier IPSET-t score. With an average follow-up of 87.7 months, there were 0.578 thrombotic events/person-year and 0.286 bleeding events/person-year after diagnosis. The 10-year thrombosis-free survival was 88% and 99% for the r-IPSET-t LR and VLR groups (p < 0.001). Cytoreduction was a thrombotic risk factor in younger patients (aged <60 years, hazard ratio 9.49, p = 0.026; aged ≥60 years, hazard ratio 1.04, p = 0.93). In multivariable Cox regression analysis, anti-aggregation after diagnosis was protective for thrombosis (hazard ratio 0.31, p = 0.005) but a risk factor for major bleeding (hazard ratio 10.56, p = 0.021). Of the IPSET-t HR and LR groups, 132/780 and 249/301 were re-classified as LR and VLR respectively (p < 0.001). The European LeukemiaNET (ELN) does not recommend aspirin for VLR patients but in this real-life analysis 83.1% of VLR patients received it. Our results validate the r-IPSET-t score as more predictive for thrombosis than the ELN-recommended IPSET-t and raise concerns about unnecessary cytoreductive and anti-aggregative therapy.

Low anti-SARS-CoV-2 S antibody levels predict increased mortality and dissemination of viral components in the blood of critical COVID-19 patients.

BACKGROUND: Anti-SARS-CoV-2 S antibodies prevent viral replication. Critically ill COVID-19 patients show viral material in plasma, associated with a dysregulated host response. If these antibodies influence survival and viral dissemination in ICU-COVID patients is unknown. PATIENTS/METHODS: We studied the impact of anti-SARS-CoV-2 S antibodies levels on survival, viral RNA-load in plasma, and N-antigenaemia in 92 COVID-19 patients over ICU admission. RESULTS: Frequency of N-antigenaemia was >2.5-fold higher in absence of antibodies. Antibodies correlated inversely with viral RNA-load in plasma, representing a protective factor against mortality (adjusted HR [CI 95%], p): (S IgM [AUC ≥ 60]: 0.44 [0.22; 0.88], 0.020); (S IgG [AUC ≥ 237]: 0.31 [0.16; 0.61], <0.001). Viral RNA-load in plasma and N-antigenaemia predicted increased mortality: (N1-viral load [≥2.156 copies/ml]: 2.25 [1.16; 4.36], 0.016); (N-antigenaemia: 2.45 [1.27; 4.69], 0.007). CONCLUSIONS: Low anti-SARS-CoV-2 S antibody levels predict mortality in critical COVID-19. Our findings support that these antibodies contribute to prevent systemic dissemination of SARS-CoV-2.

Colibrimycins, Novel Halogenated Hybrid Polyketide Synthase-Nonribosomal Peptide Synthetase (PKS-NRPS) Compounds Produced by Streptomyces sp. Strain CS147.

The improvement of genome sequencing techniques has brought to light the biosynthetic potential of actinomycetes due to the large number of gene clusters they present compared to the number of known compounds. Genome mining is a recent strategy in the search for novel bioactive compounds, which involves the analysis of sequenced genomes to identify uncharacterized natural product biosynthetic gene clusters, many of which are cryptic or silent under laboratory conditions, and to develop experimental approaches to identify their products. Owing to the importance of halogenation in terms of structural diversity, bioavailability, and bioactivity, searching for new halogenated bioactive compounds has become an interesting issue in the field of natural product discovery. Following this purpose, a screening for halogenase coding genes was performed on 12 Streptomyces strains isolated from fungus-growing ants of the Attini tribe. Using the bioinformatics tools antiSMASH and BLAST, six halogenase coding genes were identified. Some of these genes were located within biosynthetic gene clusters (BGCs), which were studied by construction of several mutants for the identification of the putative halogenated compounds produced. The comparison of the metabolite production profile of wild-type strains and their corresponding mutants by ultrahigh-performance liquid chromatography-UV and high-performance liquid chromatography-mass spectrometry allowed us the identification of a novel family of halogenated compounds in Streptomyces sp. strain CS147, designated colibrimycins. IMPORTANCE Genome mining has proven its usefulness in the search for novel bioactive compounds produced by microorganisms, and halogenases comprise an interesting starting point. In this work, we have identified a new halogenase coding gene that led to the discovery of novel lipopetide nonribosomal peptide synthetase/polyketide synthase (NRPS/PKS)-derived natural products, the colibrimycins, produced by Streptomyces sp. strain CS147, isolated from the Attini ant niche. Some colibrimycins display an unusual α-ketoamide moiety in the peptide structure. Although its biosynthetic origin remains unknown, its presence might be related to a hypothetical inhibition of virus proteases, and, together with the presence of the halogenase, it represents a feature to be incorporated in the arsenal of structural modifications available for combinatorial biosynthesis.

Immunogenomic identification and characterization of granulocytic myeloid-derived suppressor cells in multiple myeloma.

Granulocytic myeloid-derived suppressor cells (G-MDSCs) promote tumor growth and immunosuppression in multiple myeloma (MM). However, their phenotype is not well established for accurate monitoring or clinical translation. We aimed to provide the phenotypic profile of G-MDSCs based on their prognostic significance in MM, immunosuppressive potential, and molecular program. The preestablished phenotype of G-MDSCs was evaluated in bone marrow samples from controls and MM patients using multidimensional flow cytometry; surprisingly, we found that CD11b+CD14-CD15+CD33+HLADR- cells overlapped with common eosinophils and neutrophils, which were not expanded in MM patients. Therefore, we relied on automated clustering to unbiasedly identify all granulocytic subsets in the tumor microenvironment: basophils, eosinophils, and immature, intermediate, and mature neutrophils. In a series of 267 newly diagnosed MM patients (GEM2012MENOS65 trial), only the frequency of mature neutrophils at diagnosis was significantly associated with patient outcome, and a high mature neutrophil/T-cell ratio resulted in inferior progression-free survival (P < .001). Upon fluorescence-activated cell sorting of each neutrophil subset, T-cell proliferation decreased in the presence of mature neutrophils (0.5-fold; P = .016), and the cytotoxic potential of T cells engaged by a BCMA×CD3-bispecific antibody increased notably with the depletion of mature neutrophils (fourfold; P = .0007). Most interestingly, RNA sequencing of the 3 subsets revealed that G-MDSC-related genes were specifically upregulated in mature neutrophils from MM patients vs controls because of differential chromatin accessibility. Taken together, our results establish a correlation between the clinical significance, immunosuppressive potential, and transcriptional network of well-defined neutrophil subsets, providing for the first time a set of optimal markers (CD11b/CD13/CD16) for accurate monitoring of G-MDSCs in MM.