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INTRODUCTION: Neurodevelopmental disorders (NDDs) are diverse and can be explained by either genomic aberrations or single nucleotide variants. Most likely due to methodological approaches and/or disadvantages, the concurrence of both genetic events in a single patient has hardly been reported and even more rarely the pathogenic variant has been regarded as the cause of the phenotype when a chromosomal alteration is initially identified. CASE PRESENTATION: Here, we describe a NDD patient with a 6p nonpathogenic paracentric inversion paternally transmitted and a de novo pathogenic variant in the GRIN2B gene. Molecular-cytogenetic studies characterized the familial 6p inversion and revealed a paternal 9q inversion not transmitted to the patient. Subsequent whole-genome sequencing in the patient-father dyad corroborated the previous findings, discarded inversions-related cryptic genomic rearrangements as causative of the patient's phenotype, and unveiled a novel heterozygous GRIN2B variant (p.(Ser570Pro)) only in the proband. In addition, Sanger sequencing ruled out such a variant in her mother and thereby confirmed its de novo origin. Due to predicted disturbances in the local secondary structure, this variant may alter the ion channel function of the M1 transmembrane domain. Other pathogenic variants in GRIN2B have been related to the autosomal dominant neurodevelopmental disorder MRD6 (intellectual developmental disorder, autosomal dominant 6, with or without seizures), which presents with a high variability ranging from mild intellectual disability (ID) without seizures to a more severe encephalopathy. In comparison, our patient's clinical manifestations include, among others, mild ID and brain anomalies previously documented in subjects with MRD6. CONCLUSION: Occasionally, gross chromosomal abnormalities can be coincidental findings rather than a prime cause of a clinical phenotype (even though they appear to be the causal agent). In brief, this case underscores the importance of comprehensive genomic analysis in unraveling the wide-ranging genetic causes of NDDs and may bring new insights into the MRD6 variability.
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Streptomyces, the main source of antibiotics essential for human health, are widely distributed in nature among terrestrial, oceanic and atmospheric environments. New trends in antibiotic discovery are focused in the search for novel bioactive strains in unexplored habitats. We provide here evidence of the presence of diverse Streptomyces populations in wild bird feathers, such as the seagull, Larus michahellis, collected at Northern Spain; the sparrow, Passer domesticus, and the hoopoe, Upupa epops, both collected in Southern Spain. Taxonomic identification of fourteen bioactive strains, by sequencing their 16S rRNA gene and phylogenetic analyses, revealed that all of them are homologous to a total of 10 different Streptomyces. Strains from seagull samples are homologous to other antibiotic producers previously isolated from atmospheric, marine and terrestrial environments in the Cantabrian Sea region, Northern Spain. Isolates form Southern feather samples, from a house sparrow and a Eurasian hoopoe, are homologues to Streptomyces strains previously isolated mainly from soils along the Mediterranean region. The most relevant feature is that they are producers of diverse antibiotics with activity against Gram-positive, Gram-negative bacteria and fungi. We report here the successful activation of silent antibiotic biosynthetic pathways in response to changes in environmental conditions, such as incubation temperature and salinity of the culture medium, in agreement with the OSMAC approach, One Strain Many Compounds. The finding of bioactive Streptomyces in bird's plumage might be of relevance, not only in the ecology of Streptomyces-birds associations, but also in medicine and biotechnology since they can be regarded as a potential source for novel antibiotics.
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Antibacterianos , Streptomyces , Animales , Humanos , Antibacterianos/farmacología , Antibacterianos/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Plumas , Bacterias Grampositivas/genética , Bacterias Gramnegativas/genética , AvesRESUMEN
The International Initiative on Thrombosis and Cancer is an independent academic working group of experts aimed at establishing global consensus for the treatment and prophylaxis of cancer-associated thrombosis. The 2013, 2016, and 2019 International Initiative on Thrombosis and Cancer clinical practice guidelines have been made available through a free, web-based mobile phone application. The 2022 clinical practice guidelines, which are based on a literature review up to Jan 1, 2022, include guidance for patients with cancer and with COVID-19. Key recommendations (grade 1A or 1B) include: (1) low-molecular-weight heparins (LMWHs) for the initial (first 10 days) treatment and maintenance treatment of cancer-associated thrombosis; (2) direct oral anticoagulants for the initial treatment and maintenance treatment of cancer-associated thrombosis in patients who are not at high risk of gastrointestinal or genitourinary bleeding, in the absence of strong drug-drug interactions or of gastrointestinal absorption impairment; (3) LMWHs or direct oral anticoagulants for a minimum of 6 months to treat cancer-associated thrombosis; (4) extended prophylaxis (4 weeks) with LMWHs to prevent postoperative venous thromboembolism after major abdominopelvic surgery in patients not at high risk of bleeding; and (5) primary prophylaxis of venous thromboembolism with LMWHs or direct oral anticoagulants (rivaroxaban or apixaban) in ambulatory patients with locally advanced or metastatic pancreatic cancer who are treated with anticancer therapy and have a low risk of bleeding.
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COVID-19 , Neoplasias , Trombosis , Tromboembolia Venosa , Anticoagulantes/efectos adversos , COVID-19/complicaciones , Hemorragia/inducido químicamente , Heparina de Bajo-Peso-Molecular/efectos adversos , Humanos , Neoplasias/inducido químicamente , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Guías de Práctica Clínica como Asunto , Trombosis/inducido químicamente , Trombosis/complicaciones , Trombosis/tratamiento farmacológico , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/etiología , Tromboembolia Venosa/prevención & controlRESUMEN
BACKGROUND: The awake prone positioning strategy for patients with acute respiratory distress syndrome is a safe, simple and cost-effective technique used to improve hypoxaemia. We aimed to evaluate intubation and mortality risk in patients with coronavirus disease 2019 (COVID-19) who underwent awake prone positioning during hospitalisation. METHODS: In this retrospective, multicentre observational study conducted between 1 May 2020 and 12 June 2020 in 27 hospitals in Mexico and Ecuador, nonintubated patients with COVID-19 managed with awake prone or awake supine positioning were included to evaluate intubation and mortality risk through logistic regression models; multivariable and centre adjustment, propensity score analyses, and E-values were calculated to limit confounding. RESULTS: 827 nonintubated patients with COVID-19 in the awake prone (n=505) and awake supine (n=322) groups were included for analysis. Fewer patients in the awake prone group required endotracheal intubation (23.6% versus 40.4%) or died (19.8% versus 37.3%). Awake prone positioning was a protective factor for intubation even after multivariable adjustment (OR 0.35, 95% CI 0.24-0.52; p<0.0001, E=2.12), which prevailed after propensity score analysis (OR 0.41, 95% CI 0.27-0.62; p<0.0001, E=1.86) and mortality (adjusted OR 0.38, 95% CI 0.26-0.55; p<0.0001, E=2.03). The main variables associated with intubation among awake prone patients were increasing age, lower baseline peripheral arterial oxygen saturation/inspiratory oxygen fraction ratio (P aO2 /F IO2 ) and management with a nonrebreather mask. CONCLUSIONS: Awake prone positioning in hospitalised nonintubated patients with COVID-19 is associated with a lower risk of intubation and mortality.
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COVID-19 , Insuficiencia Respiratoria , COVID-19/terapia , Humanos , Oxígeno/uso terapéutico , Posición Prona , Insuficiencia Respiratoria/terapia , Estudios Retrospectivos , SARS-CoV-2 , VigiliaRESUMEN
Numerous reports of neuropsychiatric symptoms highlighted the pathologic potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its relationship the onset and/or exacerbation of mental disease. However, coronavirus disease 2019 (COVID-19) treatments, themselves, must be considered as potential catalysts for new-onset neuropsychiatric symptoms in COVID-19 patients. To date, immediate and long-term neuropsychiatric complications following SARS-CoV-2 infection are currently unknown. Here we report on five patients with SARS-CoV-2 infection with possible associated neuropsychiatric involvement, following them clinically until resolution of their symptoms. We will also discuss the contributory roles of chloroquine and dexamethasone in these neuropsychiatric presentations.
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Tratamiento Farmacológico de COVID-19 , COVID-19 , Trastornos Mentales , COVID-19/complicaciones , Cloroquina/uso terapéutico , Humanos , Trastornos Mentales/complicaciones , SARS-CoV-2RESUMEN
INTRODUCTION: Liver disease accounts for approximately 2 million deaths per year worldwide. The majority of liver diseases are due to complications of cirrhosis, viral hepatitis, and hepatocellular carcinoma. Increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) may indicate liver disease. Moreover, there are additional noninvasive liver fibrosis indices that help to estimate liver damage, including AST-to-ALT ratio, AST-to-platelet ratio index (APRI), fibrosis-4 (FIB-4) score, and nonalcoholic fatty liver disease (NAFLD) fibrosis score. The aims of the present study were to (1) perform an association analysis of the patatin-like phospholipase domain containing 3 (PNPLA3) I148M (rs738409) variant with ALT, AST, and various liver fibrosis indices, and (2) determine whether there are gender-related differences in these associations. METHODS: We obtained demographic, anthropometric, and metabolic phenotypes from Latino adult participants (n = 503, 64% female, 36.4 ± 0.5 years) from the Arizona Insulin Resistance (AIR) registry. SNP genotyping of I148M was performed using the TaqMan allelic discrimination assay. We used linear regression for the association analyses of the genotypes with ALT, AST, and the various liver fibrosis indices. We included genotype, age, body mass index, and alcohol status in the linear regression model. RESULTS: The variant I148M was in Hardy-Weinberg equilibrium, with genotype distribution: non-risk CC 118, heterozygous CG 246, and risk GG 139. The G allele was significantly associated with increased ALT and AST levels (p = 7.8 × 10-7 and p = 9.7 × 10-6, respectively). Moreover, we showed that the G allele was significantly associated with higher APRI (p = 3.7 × 10-7) and FIB-4 score (p = 4.1 × 10-3). When we analyzed the data by gender, we observed similar significant trends for ALT, AST, and APRI (all, p < 0.01). In females, the G allele was significantly associated with increased FIB-4 score (p = 6.9 × 10-3), which was not observed in the males (p > 0.05). There was no association of the I148M variant with AST/ALT ratio nor NAFLD risk score, whether analyzed in all adults or by gender. DISCUSSION/CONCLUSION: Our findings provide additional evidence of an association of PNPLA3 I148M with several liver disease biomarkers in male and female Latinos residing in the Southwest of the United States.
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Lipasa , Enfermedad del Hígado Graso no Alcohólico , Biomarcadores , Femenino , Predisposición Genética a la Enfermedad , Hispánicos o Latinos/genética , Humanos , Lipasa/genética , Masculino , Proteínas de la Membrana/genética , Enfermedad del Hígado Graso no Alcohólico/genética , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.
La leucemia mieloide aguda (LMA) comprende un grupo heterogéneo de neoplasias de células hematopoyéticas de linaje mieloide que surgen de la expansión clonal de sus precursores en la médula ósea, interfiriendo con la diferenciación celular, lo que conlleva a un síndrome de falla medular. La LMA es una consecuencia de cambios genéticos y epigenéticos (mutaciones puntuales, rearreglos de genes, deleciones, amplificaciones y arreglos en cambios epigenéticos que influyen en la expression del gen) en las células hematopoyéticas precursoras, la cual crea una clona de células anormales que son capaces de proliferar, pero no se pueden diferenciar en células hematopoyéticas maduras ni sufrir una muerte celular programada. El diagnostic requiere más del 20% de blastos mieloides en médula ósea y ciertas anormalidades citogénicas. El tratamiento dependerá de la edad, comorbilidades, riesgo citogenético entre las más frecuentes.
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Leucemia Mieloide Aguda , Diferenciación Celular , Consenso , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , MéxicoRESUMEN
BACKGROUND: The wide variation in bifurcation anatomy has generated an ongoing search for stents explicitly designed for coronary bifurcations, and to date, results have been underachieved. METHODS: The POLBOS I and POLBOS II were international, multicentre, randomized, open-label, controlled trials. Patients were randomly assigned to BiOSS Expert (in POLBOS I, biodegradable polymer eluting paclitaxel)/BiOSS LIM (in POLBOS II, biodegradable polymer eluting sirolimus) stent implantation or regular drug-eluting stent (rDES) deployment. A provisional T-stenting strategy was the default treatment option. The primary endpoint of this pooled data study was the cumulative rate of major adverse cardiovascular events (MACE) consisting of cardiac death, myocardial infarction (MI) and target lesion revascularization (TLR). Telephone follow-up was performed annually up to 72 months. (ClinicalTrials.gov Identifier: POLBOS I-NCT02192840, POLBOS II-NCT02198300). RESULTS: The total study population consisted of 445 patients, 222 patients in the BiOSS group and 223 patients in the rDES group. The follow-up rate was 93.7% in the BiOSS group and 91.9% in the rDES group. At 72 months, there was no significant difference between BiOSS and rDES groups regarding MACE (25.7% vs 25.1%, HR 1.06, 95% CI 0.73-1.52), cardiac death (3.1% vs 4.0%, HR 0.94, 95% CI 0.43-2.34), MI (3.6% vs 4.9%, HR 0.76, 95% CI 0.32-2.89), TLR (18.9% vs 16.1%, HR 1.17, 95% CI 0.75-1.83) and stent thrombosis rates (0.9% vs 0.5%, HR 1.21, 95CI 0.75-2.09). CONCLUSIONS: At the 6-year follow-up, clinically significant clinical events did not differ between BiOSS stents and rDES.
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Implantes Absorbibles , Vasos Coronarios/patología , Stents Liberadores de Fármacos , Anciano , Stents Liberadores de Fármacos/clasificación , Femenino , Cardiopatías , Insuficiencia Cardíaca/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Sirolimus/uso terapéuticoRESUMEN
The development of an efficient method for the synthesis of polysubstituted isoindolinones from 1,3-dicarbonyl Ugi-4CR adducts, employing an aromatic radical cyclization process promoted by tetrabutylammonium persulfate and 2,2,6,6-tetramethyl-1-piperidine 1-oxyl (TEMPO), is described. The protocol allowed the construction of a library of isoindolinones bearing a congested carbon in good to excellent yields under mild conditions and in short reaction times.
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INTRODUCTION: Neutrophil-to-lymphocyte (NLR) and lymphocyte-to-C-reactive protein (LCR) ratios are used to predict severity and mortality in various infections. OBJECTIVE: To establish the best NLR and LCR cutoff point to predict mortality in patients hospitalized for COVID-19 in Mexico. METHOD: Analytical cross-sectional study of patients hospitalized for severe COVID-19 in a specialty hospital. RESULTS: Out of 242 analyzed patients, 34 % died. The deceased subjects were older (62 vs. 51 years; p < 0.001), had a higher prevalence of > 10 years with systemic arterial hypertension (59.4 vs. 45.1 %, p = 0.022), as well as a higher NLR (17.66 vs. 8.31, p < 0.001) and lower LCR (0.03 vs. 0.06, p < 0.002) with regard to those who survived. The cutoff points to predict mortality were NLR > 12 and LCR < 0.03. The combination of NLR/LCR had a sensitivity of 80 %, specificity of 74 %, positive predictive value of 46.15 %, negative predictive value of 93.02 % and an odds ratio of 11.429 to predict mortality. CONCLUSION: NLR > 12 and LCR < 0.03 are useful biomarkers to evaluate the risk of mortality in Mexican patients with severe COVID- 19. INTRODUCCIÓN: Los índices neutrófilo/linfocito (INL) y linfocito/proteína C reactiva (ILR) se usan para predecir severidad y mortalidad en diversas infecciones. OBJETIVO: Establecer en México el mejor punto de corte de INL e ILR para predecir la mortalidad en pacientes hospitalizados por COVID-19. MÉTODO: Estudio transversal analítico de pacientes hospitalizados por COVID-19 grave en un hospital de especialidades. RESULTADOS: Falleció 34 % de 242 pacientes analizados. Los sujetos fallecidos tenían mayor edad (62 versus 51 años, p < 0.001), mayor prevalencia de hipertensión arterial sistémica > 10 años (59.4 versus 45.1 %, p = 0.022), así como INL más alto (17.66 versus 8.31, p < 0.001) e ILR más bajo (0.03 versus 0.06, p < 0.002) respecto a quienes sobrevivieron. Los puntos de corte para predecir mortalidad fueron INL > 12 e ILR < 0.03. La combinación de INL e ILR tuvo sensibilidad de 80 %, especificidad de 74 %, valor predictivo positivo de 46.15 %, valor predictivo negativo de 93.02 % y razón de momios de 11.429 para predecir la mortalidad. CONCLUSIÓN: INL > 12 e ILR < 0.03 son biomarcadores útiles para evaluar el riesgo de mortalidad en pacientes mexicanos con COVID-19 grave.
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Proteína C-Reactiva/metabolismo , COVID-19/fisiopatología , Linfocitos/metabolismo , Neutrófilos/metabolismo , Adulto , Anciano , COVID-19/mortalidad , Estudios Transversales , Femenino , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Índice de Severidad de la EnfermedadRESUMEN
The development of a novel protocol for the fast introduction of the picolinamide directing group in aliphatic ketones by using the ammonia-Ugi 4-CR reaction and the subsequent evaluation of the Pd-mediated γ-C(sp3)-H bond activation is described. The methodology allows the efficient construction of a series of γ-arylated α-aminoamides bearing a congested carbon in two steps.
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The isolation and structural elucidation of a structurally new desertomycin, designated as desertomycin G (1), with strong antibiotic activity against several clinically relevant antibiotic resistant pathogens are described herein. This new natural product was obtained from cultures of the marine actinomycete Streptomyces althioticus MSM3, isolated from samples of the intertidal seaweed Ulva sp. collected in the Cantabrian Sea (Northeast Atlantic Ocean). Particularly interesting is its strong antibiotic activity against Mycobacterium tuberculosis clinical isolates, resistant to antibiotics in clinical use. To the best of our knowledge, this is the first report on a member of the desertomycin family displaying such activity. Additionally, desertomycin G shows strong antibiotic activities against other relevant Gram-positive clinical pathogens such as Corynebacterium urealyticum, Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecium, Enterococcus faecalis, and Clostridium perfringens. Desertomycin G also displays moderate antibiotic activity against relevant Gram-negative clinical pathogens such as Bacteroides fragilis, Haemophilus influenzae and Neisseria meningitidis. In addition, the compound affects viability of tumor cell lines, such as human breast adenocarcinoma (MCF-7) and colon carcinoma (DLD-1), but not normal mammary fibroblasts.
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Antibióticos Antineoplásicos/farmacología , Antituberculosos/farmacología , Macrólidos/farmacología , Microalgas/microbiología , Mycobacterium tuberculosis/efectos de los fármacos , Streptomyces/química , Productos Biológicos/química , Productos Biológicos/farmacología , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Microalgas/clasificación , Pruebas de Sensibilidad MicrobianaRESUMEN
OBJECTIVE: To gather opinions from medical schools regarding the existence of public policies on the health workforce (human resources for health) and whether sufficient public financing and regulatory mechanisms are in place for undergraduate medical education; and to identify areas of opportunity to improve the availability of general practitioners in the Region of the Americas. METHODS: Cross-sectional, descriptive study conducted with 105 medical schools (51 public and 54 private) in 17 countries. A questionnaire with a Likert scale was used to explore three dimensions (political, economic, and regulatory contexts) composed of 4, 2, and 4 variables each, respectively, and validated with the Delphi method. Frequencies of responses to the questions were estimated. A frequency analysis was performed, as well as a bivariate analysis to identify differences between public and private schools, applying the Chi-square test to compare percentages. RESULTS: The political context was considered favorable by 64% of the schools; the economic context, by 37%; and the regulatory context, by 23%. The only significant differences between public and private schools were in the financial resources they administer. CONCLUSIONS: It is necessary to strengthen public policies, public investment, and the regulation of medical education in order to improve the education and availability of general practitioners in the countries of the Region.
OBJETIVO: Conhecer a opinião das faculdades de medicina sobre o volume de políticas públicas e financiamento público e mecanismos reguladores para graduação médica e identificar áreas que possibilitem aumentar o número de clínicos gerais na Região das Américas. MÉTODOS: Estudo transversal descritivo realizado com 105 faculdades de medicina (51 públicas e 54 particulares) em 17 países. Um questionário com uma escala tipo Likert foi usado para explorar três dimensões (contexto político, contexto econômico e regulamentação), contendo 4, 2 e 4 variáveis cada, e foi validado com o método Delphi. As frequências de respostas às perguntas do questionário foram calculadas e analisadas. A fim de identificar diferenças entre as faculdades públicas e particulares, uma análise bivariada com teste qui-quadrado foi realizada para comparar porcentagens. RESULTADOS: O contexto político foi considerado favorável por 64% das faculdades; o contexto econômico por 37%; e a regulamentação por 23%. Apenas foi observada diferença significativa entre as faculdades públicas e particulares na variável recursos financeiros geridos. CONCLUSÕES: É necessário fortalecer as políticas públicas, o investimento público e a regulamentação da educação médica para melhorar a formação e aumentar o número de clínicos gerais nos países da Região.
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The potent antimicrobial extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-169 was fractionated by reversed phase flash chromatography and preparative HPLC to yield the new Gram-positive antibiotic, anthracimycin B (1), together with its congener, anthracimycin (2). The structure of the new compound was established by analysis of its ESI-TOF MS and 1D and 2D NMR spectra, and comparison with data published for anthracimycin and anthracimycin BII-2619 (3). Notably, anthracimycin seemed to be the major and almost unique component of the extract detected by HPLC-UV-MS, making our S. cyanofuscatus strain an excellent candidate for further biosynthetic studies of this potent antibiotic.
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Bacterias Grampositivas/efectos de los fármacos , Policétidos/química , Policétidos/farmacología , Streptomyces/química , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Organismos Acuáticos/química , Pruebas de Sensibilidad Microbiana , Filogenia , Policétidos/aislamiento & purificación , Streptomyces/genéticaRESUMEN
Fractionation of the bioactive extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-157 led to the isolation of the known 3-hydroxyquinaldic acid (4), its amide (5) and three new derivatives (1â»3) containing different amino acid residues. The structures of the new molecules (1â»3), including their absolute configuration, were determined by the analysis of their ESI-TOF MS and one-dimensional (1D) and two-dimensional (2D) NMR spectra and advanced Marfey's analysis of their hydrolyzation products. Compound 3 spontaneously dimerized in solution to give the disulfide derivative 6. Unfortunately, none of the new compounds isolated confirmed the antimicrobial activity found in the bacterial extract, perhaps indicating that such antibacterial activity might be due to presence in the extract at the trace level of larger bioactive 3-hydroxyquinaldic acid derivatives from which compounds 1â»3 are biosynthetic precursors. Cytotoxicity tests confirmed the moderate and weak IC50 values of 15.6 and 51.5 µM for compounds 5 and 1, respectively.
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Actinobacteria/química , Antibacterianos/química , Organismos Acuáticos/química , Ácido Quinurénico/análogos & derivados , Streptomyces/química , Ácido Quinurénico/química , Espectroscopía de Resonancia Magnética/métodos , Pruebas de Sensibilidad Microbiana/métodosRESUMEN
Marine Actinobacteria are emerging as an unexplored source for natural product discovery. Eighty-seven deep-sea coral reef invertebrates were collected during an oceanographic expedition at the submarine Avilés Canyon (Asturias, Spain) in a range of 1500 to 4700 m depth. From these, 18 cultivable bioactive Actinobacteria were isolated, mainly from corals, phylum Cnidaria, and some specimens of phyla Echinodermata, Porifera, Annelida, Arthropoda, Mollusca and Sipuncula. As determined by 16S rRNA sequencing and phylogenetic analyses, all isolates belong to the phylum Actinobacteria, mainly to the Streptomyces genus and also to Micromonospora, Pseudonocardia and Myceligenerans. Production of bioactive compounds of pharmacological interest was investigated by high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) techniques and subsequent database comparison. Results reveal that deep-sea isolated Actinobacteria display a wide repertoire of secondary metabolite production with a high chemical diversity. Most identified products (both diffusible and volatiles) are known by their contrasted antibiotic or antitumor activities. Bioassays with ethyl acetate extracts from isolates displayed strong antibiotic activities against a panel of important resistant clinical pathogens, including Gram-positive and Gram-negative bacteria, as well as fungi, all of them isolated at two main hospitals (HUCA and Cabueñes) from the same geographical region. The identity of the active extracts components of these producing Actinobacteria is currently being investigated, given its potential for the discovery of pharmaceuticals and other products of biotechnological interest.
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Actinobacteria/química , Actinobacteria/clasificación , Actinobacteria/aislamiento & purificación , Antozoos/microbiología , Productos Biológicos/farmacología , Filogenia , Actinobacteria/genética , Animales , Antibacterianos/farmacología , Antineoplásicos/farmacología , Bacterias/efectos de los fármacos , Secuencia de Bases , Biodiversidad , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Bioprospección , Línea Celular Tumoral/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Clasificación , Arrecifes de Coral , ADN Bacteriano , Ecosistema , Cromatografía de Gases y Espectrometría de Masas , Genes Bacterianos , Invertebrados/microbiología , Biología Marina , Extractos Vegetales , ARN Ribosómico 16S/genética , Agua de Mar , Metabolismo Secundario , España , Streptomyces/clasificación , Streptomyces/aislamiento & purificaciónRESUMEN
A synthetic approach to the 6-methyl-3,4-dihydropyrazinone core from Ugi adducts is described. This methodology relies on the regioselective C-N bond formation between an allenamide moiety at C-ß and an amide anion formed under base-mediated conditions. This protocol allows easy access to tricyclic systems such as pyrazino[2,1-a]isoindole and pyrazino[2,1-a]isoquinoline nuclei.
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Two new antibiotics, branimycins B (2) and C (3), were produced by fermentation of the abyssal actinobacterium Pseudonocardia carboxydivorans M-227, isolated from deep seawater of the Avilés submarine Canyon. Their structures were elucidated by HRMS and NMR analyses. These compounds exhibit antibacterial activities against a panel of Gram-positive bacteria, including Corynebacterium urealyticum, Clostridium perfringens, and Micrococcus luteus, and against the Gram-negative bacterium Neisseria meningitidis. Additionally, branimycin B displayed moderate antibacterial activity against other Gram-negative bacteria such as Bacteroides fragilis, Haemophilus influenzae, and Escherichia coli, and branimycin C against the Gram-positive Enterococcus faecalis and methicillin-sensitive and methicillin-resistant Staphylococcus aureus.
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Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Macrólidos/aislamiento & purificación , Macrólidos/farmacología , Antibacterianos/química , Enterococcus faecalis , Bacterias Gramnegativas , Bacterias Grampositivas , Haemophilus influenzae , Macrólidos/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
The present article describes the isolation of a new natural product of the lobophorin family, designated as lobophorin K (1), from cultures of the marine actinobacteria Streptomyces sp. M-207, previously isolated from the cold-water coral Lophelia pertusa collected at 1800 m depth during an expedition to the submarine Avilés Canyon. Its structure was determined using a combination of spectroscopic techniques, mainly ESI-TOF MS and 1D and 2D NMR. This new natural product displayed cytotoxic activity against two human tumor cell lines, such as pancreatic carcinoma (MiaPaca-2) and breast adenocarcinoma (MCF-7). Lobophorin K also displayed moderate and selective antibiotic activity against pathogenic Gram-positive bacteria such as Staphylococcus aureus.
Asunto(s)
Antozoos/microbiología , Antineoplásicos/farmacología , Macrólidos/química , Macrólidos/farmacología , Streptomyces/metabolismo , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Macrólidos/metabolismo , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Filogenia , Streptomyces/genéticaRESUMEN
The present article describes a structurally novel natural product of the paulomycin family, designated as paulomycin G (1), obtained from the marine strain Micromonospora matsumotoense M-412, isolated from Cantabrian Sea sediments collected at 2000 m depth during an oceanographic expedition to the submarine Avilés Canyon. Paulomycin G is structurally unique since-to our knowledge-it is the first member of the paulomycin family of antibiotics lacking the paulomycose moiety. It is also the smallest bioactive paulomycin reported. Its structure was determined using HRMS and 1D and 2D NMR spectroscopy. This novel natural product displays strong cytotoxic activities against different human tumour cell lines, such as pancreatic adenocarcinoma (MiaPaca_2), breast adenocarcinoma (MCF-7), and hepatocellular carcinoma (HepG2). The compound did not show any significant bioactivity when tested against a panel of bacterial and fungal pathogens.