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1.
Nature ; 606(7914): 475-478, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35705818

RESUMEN

Galaxy protoclusters, which will eventually grow into the massive clusters we see in the local Universe, are usually traced by locating overdensities of galaxies1. Large spectroscopic surveys of distant galaxies now exist, but their sensitivity depends mainly on a galaxy's star-formation activity and dust content rather than its mass. Tracers of massive protoclusters that do not rely on their galaxy constituents are therefore needed. Here we report observations of Lyman-α absorption in the spectra of a dense grid of background galaxies2,3, which we use to locate a substantial number of candidate protoclusters at redshifts 2.2 to 2.8 through their intergalactic gas. We find that the structures producing the most absorption, most of which were previously unknown, contain surprisingly few galaxies compared with the dark-matter content of their analogues in cosmological simulations4,5. Nearly all of the structures are expected to be protoclusters, and we infer that half of their expected galaxy members are missing from our survey because they are unusually dim at rest-frame ultraviolet wavelengths. We attribute this to an unexpectedly strong and early influence of the protocluster environment6,7 on the evolution of these galaxies that reduced their star formation or increased their dust content.

2.
Mar Drugs ; 22(6)2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38921579

RESUMEN

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.


Asunto(s)
Péptidos , Humanos , Péptidos/química , Péptidos/farmacología , Péptidos/aislamiento & purificación , Actinobacteria/química , Actinobacteria/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Organismos Acuáticos , Productos Biológicos/farmacología , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Línea Celular Tumoral , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/aislamiento & purificación
3.
Int J Mol Sci ; 25(4)2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38397022

RESUMEN

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.


Asunto(s)
Depsipéptidos , Piridazinas , Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo , Familia de Multigenes , Depsipéptidos/genética , Depsipéptidos/metabolismo , Aminoácidos/metabolismo
4.
J Nurs Scholarsh ; 55(1): 56-66, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36102356

RESUMEN

AIMS AND OBJECTIVES: The aim of the present study is to investigate the professional grief suffered by nurses in various medical units, after coping with the COVID-19 pandemic for the last 18 months. BACKGROUND: Addressing and acknowledging the reality of professional grief is of fundamental importance to nurses' mental health, as this condition has both professional and personal consequences. DESIGN: A qualitative, content analysis approach was taken. METHODS: Based on 25 interviews with nursing professionals working in different health centers units were performed. The following sampling schemes were used: first, convenience sampling, then nominated sampling, and finally theoretical sampling. RESULTS: From our analysis of the data obtained, three main themes were identified: the impact on nurses of COVID-19 outcomes; the symptoms of professional grief; and cognitive reactions. These core elements interacted with 12 subtopics, including symptoms of grief and the cognitive impact produced. CONCLUSIONS: A large proportion of the nurses consulted in this study have suffered and suffered professional grief and report many related symptoms. In response to the present pandemic and any future occurrence, the question of professional grief needs to be addressed. RELEVANCE TO CLINICAL PRACTICE: To help them cope better with this type of situation, nurses should receive appropriate training. Moreover, healthcare institutions should be made aware of the problem and be encouraged to offer assistance to address the impact produced on nurses by the deaths of their patients. CLINICAL RELEVANCE: This study shows the impact of professional grief on nurses in the context of the COVID-19 pandemic. Nurses are affected personally by the deaths of patients and by alterations to their working conditions. In many cases, this grief remains unresolved and its various symptoms persist.


Asunto(s)
COVID-19 , Enfermeras y Enfermeros , Humanos , Pandemias , Salud Pública , Pesar , Investigación Cualitativa
5.
Int J Mol Sci ; 24(9)2023 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-37175904

RESUMEN

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.


Asunto(s)
Antibacterianos , Streptomyces , Antibacterianos/química , Factores de Transcripción/metabolismo , Familia de Multigenes , Genes Reguladores , Streptomyces/genética , Streptomyces/metabolismo , Hidroxibenzoatos/metabolismo
6.
Wilderness Environ Med ; 34(4): 536-542, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37586947

RESUMEN

Long-distance "thru-hiking" has extraordinary physical demands and has become increasingly popular. This report describes a man (55 y) who thru-hiked the Pacific Crest Trail in 2021 and was at risk of developing the relative energy deficiency in sport (RED-S) syndrome. Hiking distance was 3767 km over 128 d. Eighty-eight days (69%) were full days of hiking, covering 38±8 km/d (mean±SD) in 7.9±1.6 h/d. Exercise energy expenditure above rest (heart rate vs indirect calorimetry regression method) was 2834±1518 kcal/d, total energy expenditure was 5702±1323 kcal/d, and energy intake was 4141 kcal/d. Body mass decreased by 9%, and fat mass (dual-energy X-ray absorptiometry) decreased by 46%. Energy availability (energy intake minus exercise energy expenditure) was 19.3 kcal/d/kg fat-free mass, indicating low energy availability (defined as <30 kcal/d/kg). Dual-energy X-ray absorptiometry-measured spine bone mineral density (BMD) decreased by 8.6%, with little to no decrease in total hip (-1.0%) and femoral neck (-1.5%) BMD. Total cholesterol, low-density lipoprotein cholesterol, and triglycerides increased by 24, 39, and 57%, respectively. Within 8 mo after the hike, BMD and serum lipids nearly or fully returned to baseline. No changes in high-density lipoprotein cholesterol, glycemia, or blood pressure were observed. According to guidelines, these observations are consistent with a moderate risk of RED-S, and a medical evaluation and treatment plan are advisable in order to avoid clinical manifestations (eg, stress fractures, anemia, psychological disturbances). To minimize RED-S risk, it may be prudent for thru-hikers to optimize energy availability by moderating daily hiking distances and/or increasing food intake.


Asunto(s)
Densidad Ósea , Deficiencia Relativa de Energía en el Deporte , Masculino , Humanos , Densidad Ósea/fisiología , Ingestión de Energía , Absorciometría de Fotón , Metabolismo Energético , Colesterol
7.
Appl Environ Microbiol ; 88(1): e0183921, 2022 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-34669429

RESUMEN

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.


Asunto(s)
Sintasas Poliquetidas , Streptomyces , Familia de Multigenes , Péptido Sintasas/genética , Filogenia , Sintasas Poliquetidas/genética , Streptomyces/genética
8.
J Am Acad Dermatol ; 87(3): 623-631, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-32592878

RESUMEN

BACKGROUND: Transition from pediatric to adult care is a critical component of health care for children with long-term needs. The characteristics of epidermolysis bullosa (EB) demand higher than average levels of provider support. There is consensus among health care professionals regarding the importance of transition; however, there is a scarcity of practical information regarding models for patients with EB. OBJECTIVE: To review transition of care programs in varying specialties. Highlight practical considerations to facilitate the development of programs for patients with EB and other complex dermatologic conditions. METHODS: Articles were identified via MEDLINE and EMBASE health literature databases and screened for relevance to transition of care. RESULTS: Various models for transition exist. A well-executed formal transition program, early introduction, interdisciplinary collaboration, and psychosocial support were themes associated with successful outcomes. LIMITATIONS: Transition of care programs that have not been described in the literature are not reflected in this review. CONCLUSIONS: Patients with EB have unique needs that affect transition and span expertise across traditional boundaries, such as dependency on others for daily skin care, failure to thrive, and risk of squamous cell carcinoma. Given the rarity of the disease, patients with EB will benefit from collaborative efforts to develop programs to optimize successful transition.


Asunto(s)
Epidermólisis Ampollosa , Transición a la Atención de Adultos , Adulto , Niño , Consenso , Bases de Datos Factuales , Epidermólisis Ampollosa/complicaciones , Epidermólisis Ampollosa/terapia , Humanos , Transferencia de Pacientes
9.
Anal Bioanal Chem ; 414(28): 8063-8070, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36194241

RESUMEN

The determination of amino acid chirality in natural peptides is typically addressed by Marfey's analysis. This approach relies on the complete hydrolysis of the peptide followed by the reaction of the resulting amino acid pool with Marfey's reagent, a chiral derivatizing agent which turns amino acid enantiomers into diastereomeric pairs which can be resolved by conventional reversed-phase HPLC. However, for certain amino acids possessing a second chiral centre at Cß, the discrimination between the two possible epimers may still be challenging due to the lack of chromatographic resolution. Such is the case of isoleucine and threonine which can also be found in natural nonribosomal peptides as their allo-diastereomers. We describe a new approach based on the extension of Marfey's analysis using HPLC-SPE-NMR to sort out this challenge. Marfey's derivatives of these epimeric amino acids at Cß can be differentiated by their distinct NMR spectra. Thus, simple comparison of the NMR spectra of trapped HPLC peaks with the corresponding spectra of standards enables the unambiguous assignment of the absolute configuration at the second chiral centre in such cases. The general applicability of this approach is showcased for two model cyclic peptides bearing L-Ile and L-Thr.


Asunto(s)
Isoleucina , Treonina , Cromatografía Líquida de Alta Presión/métodos , Aminoácidos/análisis , Estereoisomerismo , Péptidos/química , Aminas
10.
Public Health Nutr ; : 1-7, 2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35356855

RESUMEN

OBJECTIVE: The purpose of the current study was to cross-culturally adapt and validate an online questionnaire to assess eating habits and physical activity of university students under confinement due to coronavirus disease (COVID-19). DESIGN: Generation of a cross-sectional online survey to university students conducted during confinement due to COVID-19. The study was divided into two phases. SETTINGS: Students, Chile. PARTICIPANTS: Phase 1 considered the process of translation and back translation, expert panel, cultural adaptation and the generation of a pilot to validate a preliminary format of the questionnaire. In Phase 2, information from the instrument was collected from two hundred and sixty-eight university students, ages 16 to 30 years old, with a mean age of 21·6 (3·3) The major proportion of participants were female (82 %). RESULTS: The adapted questionnaire was statistically validated in three dimensions: (A) eating habits and behaviours during quarantine, (B) perception of risk and (C) physical activity changes during the quarantine. The reliability of Cronbach's α for dimensions A, B and C was 0·59, 0·85 and 0·97, respectively. The complete questionnaire obtained 0·61 in internal consistency and 0·61 (0·58-0·67) ICC reliability. A statistically significant positive correlation matrix was observed. CONCLUSIONS: This questionnaire is a practical tool to obtain accurate information about the relation of COVID-19 confinement on people's eating habits and physical activity. Therefore, it could contribute to establishing appropriate strategies to prevent negative effects on people's health.

11.
Int J Mol Sci ; 23(18)2022 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-36142411

RESUMEN

The protozoan parasite Leishmania, responsible for leishmaniasis, is one of the few aerobic organisms that cannot synthesize the essential molecule heme. Therefore, it has developed specialized pathways to scavenge it from its host. In recent years, some proteins involved in the import of heme, such as LHR1 and LFLVCRB, have been identified, but relevant aspects regarding the process remain unknown. Here, we characterized the kinetics of the uptake of the heme analogue Zn(II) Mesoporphyrin IX (ZnMP) in Leishmania major promastigotes as a model of a parasite causing cutaneous leishmaniasis with special focus on the force that drives the process. We found that ZnMP uptake is an active, inducible, and pH-dependent process that does not require a plasma membrane proton gradient but requires the presence of the monovalent cations Na+ and/or K+. In addition, we demonstrated that this parasite can efflux this porphyrin against a concentration gradient. We also found that ZnMP uptake differs among different dermotropic or viscerotropic Leishmania species and does not correlate with LHR1 or LFLVCRB expression levels. Finally, we showed that these transporters have only partially overlapping functions. Altogether, these findings contribute to a deeper understanding of an important process in the biology of this parasite.


Asunto(s)
Leishmania major , Leishmaniasis Cutánea , Porfirinas , Hemo/metabolismo , Humanos , Leishmania major/metabolismo , Leishmaniasis Cutánea/parasitología , Metaloporfirinas , Porfirinas/metabolismo , Protones
12.
Int J Mol Sci ; 23(11)2022 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-35682786

RESUMEN

Sleeping sickness or African trypanosomiasis is a serious health concern with an added socio-economic impact in sub-Saharan Africa due to direct infection in both humans and their domestic livestock. There is no vaccine available against African trypanosomes and its treatment relies only on chemotherapy. Although the current drugs are effective, most of them are far from the modern concept of a drug in terms of toxicity, specificity and therapeutic regime. In a search for new molecules with trypanocidal activity, a high throughput screening of 2000 microbial extracts was performed. Fractionation of one of these extracts, belonging to a culture of the fungus Amesia sp., yielded a new member of the curvicollide family that has been designated as curvicollide D. The new compound showed an inhibitory concentration 50 (IC50) 16-fold lower in Trypanosoma brucei than in human cells. Moreover, it induced cell cycle arrest and disruption of the nucleolar structure. Finally, we showed that curvicollide D binds to DNA and inhibits transcription in African trypanosomes, resulting in cell death. These results constitute the first report on the activity and mode of action of a member of the curvicollide family in T. brucei.


Asunto(s)
Tripanocidas , Trypanosoma brucei brucei , Tripanosomiasis Africana , Animales , Hongos , Humanos , Tripanocidas/química , Tripanocidas/farmacología , Tripanosomiasis Africana/tratamiento farmacológico
13.
Angew Chem Int Ed Engl ; 61(23): e202203175, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35325497

RESUMEN

By limiting the nitrogen source to glutamic acid, we isolated cyclic peptides from Euglena gracilis containing asparagine and non-proteinogenic amino acids. Structure elucidation was accomplished through spectroscopic methods, mass spectrometry and chemical degradation. The euglenatides potently inhibit pathogenic fungi and cancer cell lines e.g., euglenatide B exhibiting IC50 values of 4.3 µM in Aspergillus fumigatus and 0.29 µM in MCF-7 breast cancer cells. In an unprecedented convergence of non-ribosomal peptide synthetase and polyketide synthase assembly-line biosynthesis between unicellular species and the metazoan kingdom, euglenatides bear resemblance to nemamides from Caenorhabditis elegans and inhibited both producing organisms E. gracilis and C. elegans. By molecular network analysis, we detected over forty euglenatide-like metabolites in E. gracilis, E. sanguinea and E. mutabilis, suggesting an important biological role for these natural products.


Asunto(s)
Euglena gracilis , Microalgas , Animales , Caenorhabditis elegans , Euglena gracilis/metabolismo , Agua Dulce , Péptidos Cíclicos/metabolismo , Péptidos Cíclicos/farmacología
14.
Chembiochem ; 22(12): 2087-2092, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33440038

RESUMEN

The absolute configuration of the constituent amino acids in microbial nonribosomal peptides is typically determined by Marfey's method after total hydrolysis of the peptide. A challenge to structure elucidation arises when both d and l enantiomeric configurations of an amino acid are present. Determining the actual position of each amino acid enantiomer within the peptide sequence typically requires laborious approaches based on peptide partial hydrolysis or even total synthesis of the possible diastereomers. Herein, an alternative solution is discussed based on the homogeneous backbone chirality that governs all peptides biosynthesized by a common nonribosomal peptide synthetase. The information on configuration provided by Marfey's analysis of co-occurring minor congeners can reveal unequivocally the stereochemical sequence of the whole peptide family.


Asunto(s)
Aminoácidos/metabolismo , Péptidos/metabolismo , Aminoácidos/química , Estructura Molecular , Péptido Sintasas/metabolismo , Péptidos/química , Estereoisomerismo
15.
Biomacromolecules ; 22(4): 1374-1388, 2021 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-33724003

RESUMEN

The latest trends in cancer research and nanomedicine focus on using nanocarriers to target cancer stem cells (CSCs). Specifically, lipid liquid nanocapsules are usually developed as nanocarriers for lipophilic drug delivery. Here, we developed olive oil liquid NCs (O2LNCs) functionalized by covalent coupling of an anti-CD44-fluorescein isothiocyanate antibody (αCD44). First, O2LNCs are formed by a core of olive oil surrounded by a shell containing phospholipids, a nonionic surfactant, and deoxycholic acid molecules. Then, O2LNCs were coated with an αCD44 antibody (αCD44-O2LNC). The optimization of an αCD44 coating procedure, a complete physicochemical characterization, as well as clear evidence of their efficacy in vitro and in vivo were demonstrated. Our results indicate the high targeted uptake of these αCD44-O2LNCs, and the increased antitumor efficacy (up to four times) of paclitaxel-loaded-αCD44-O2LNC compared to free paclitaxel in pancreatic CSCs (PCSCs). Also, αCD44-O2LNCs were able to selectively target PCSCs in an orthotopic xenotransplant in vivo model.


Asunto(s)
Nanocápsulas , Neoplasias Pancreáticas , Humanos , Células Madre Neoplásicas , Aceite de Oliva , Paclitaxel/farmacología , Neoplasias Pancreáticas/tratamiento farmacológico
16.
Malar J ; 20(1): 457, 2021 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-34865639

RESUMEN

BACKGROUND: Malaria is a global health problem for which novel therapeutic compounds are needed. To this end, a recently published novel family of antiplasmodial macrolides, strasseriolides A-D, was herein subjected to in vivo efficacy studies and preclinical evaluation in order to identify the most promising candidate(s) for further development. METHODS: Preclinical evaluation of strasseriolides A-D was performed by MTT-based cytotoxicity assay in THLE-2 (CRL-2706) liver cells, cardiotoxicity screening using the FluxOR™ potassium assay in hERG expressed HEK cells, LC-MS-based analysis of drug-drug interaction involving CYP3A4, CYP2D6 and CYP2C9 isoforms inhibition and metabolic stability assays in human liver microsomes. Mice in vivo toxicity studies were also accomplished by i.v. administration of the compounds (vehicle: 0.5% HPMC, 0.5% Tween 80, 0.5% Benzyl alcohol) in mice at 25 mg/kg dosage. Plasma were prepared from mice blood samples obtained at different time points (over a 24-h period), and analysed by LC-MS to quantify compounds. The most promising compounds, strasseriolides C and D, were subjected to a preliminary in vivo efficacy study in which transgenic GFP-luciferase expressing Plasmodium berghei strain ANKA-infected Swiss Webster female mice (n = 4-5) were treated 48 h post-infection with an i.p. dosage of strasseriolide C at 50 mg/kg and strasseriolide D at 22 mg/kg for four days after which luciferase activity was quantified on day 5 in an IVIS® Lumina II imager. RESULTS: Strasseriolides A-D showed no cytotoxicity, no carditoxicity and no drug-drug interaction problems in vitro with varying intrinsic clearance (CLint). Only strasseriolide B was highly toxic to mice in vivo (even at 1 mg/kg i.v. dosage) and, therefore, discontinued in further in vivo studies. Strasseriolide D showed statistically significant activity in vivo giving rise to lower parasitaemia levels (70% lower) compared to the controls treated with vehicle. CONCLUSIONS: Animal efficacy and preclinical evaluation of the recently discovered potent antiplasmodial macrolides, strasseriolides A-D, led to the identification of strasseriolide D as the most promising compound for further development. Future studies dealing on structure optimization, formulation and establishment of optimal in vivo dosage explorations of this novel compound class could enhance their clinical potency and allow for progress to later stages of the developmental pipeline.


Asunto(s)
Antimaláricos , Ascomicetos/química , Macrólidos , Malaria/tratamiento farmacológico , Plasmodium berghei/efectos de los fármacos , Animales , Antimaláricos/química , Antimaláricos/farmacología , Antimaláricos/toxicidad , Evaluación Preclínica de Medicamentos , Femenino , Macrólidos/química , Macrólidos/farmacología , Macrólidos/toxicidad , Ratones
17.
Cell Mol Life Sci ; 77(9): 1827-1845, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31372684

RESUMEN

Leishmaniasis comprises a group of neglected diseases caused by the protozoan parasite Leishmania spp. As is the case for other trypanosomatid parasites, Leishmania is auxotrophic for heme and must scavenge this essential compound from its human host. In mammals, the SLC transporter FLVCR2 mediates heme import across the plasma membrane. Herein we identify and characterize Leishmania major FLVCRb (LmFLVCRb), the first member of the FLVCR family studied in a non-metazoan organism. This protein localizes to the plasma membrane of the parasite and is able to bind heme. LmFLVCRb levels in Leishmania, which are modulated by overexpression thereof or the abrogation of an LmFLVCRb allele, correlate with the ability of the parasite to take up porphyrins. Moreover, injection of LmFLVCRb cRNA to Xenopus laevis oocytes provides these cells with the ability to take up heme. This process is temperature dependent, requires monovalent ions and is inhibited at basic pH, characteristics shared by the uptake of heme by Leishmania parasites. Interestingly, LmFLVCRb is essential as CRISPR/Cas9-mediated knockout parasites were only obtained in the presence of an episomal copy of the gene. In addition, deletion of just one of the alleles of the LmFLVCRb gene markedly impairs parasite replication as intracellular amastigotes as well as its virulence in an in vivo model of cutaneous leishmaniasis. Collectively, these results show that Leishmania parasites can rescue heme through plasma membrane transporter LFLVCRb, which could constitute a novel target for therapeutic intervention against Leishmania and probably other trypanosomatid parasites in which FLVCR genes are also present.


Asunto(s)
Hemo/metabolismo , Leishmania major/metabolismo , Leishmaniasis/parasitología , Macrófagos/parasitología , Proteínas de Transporte de Membrana/metabolismo , Porfirinas/metabolismo , Proteínas Protozoarias/metabolismo , Receptores Virales/metabolismo , Secuencia de Aminoácidos , Animales , Transporte Biológico , Membrana Celular/metabolismo , Células Cultivadas , Humanos , Leishmania major/patogenicidad , Leishmaniasis/metabolismo , Macrófagos/metabolismo , Proteínas de Transporte de Membrana/genética , Oocitos/metabolismo , Oocitos/parasitología , Proteínas Protozoarias/genética , Receptores Virales/genética , Homología de Secuencia , Virulencia , Xenopus laevis
18.
Pediatr Dermatol ; 38(1): 239-241, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33169884

RESUMEN

Continuous subcutaneous insulin infusion (CSII), or insulin pumps, with or without continuous glucose monitoring (CGM) devices have become the standard of care for patients with type 1 diabetes. While increasingly popular, a wide range of reported skin reactions to CSII and CGM devices was found. We present this case of a pyogenic granuloma-like neutrophilic and granulomatous response to an insulin pump to increase awareness of a previously uncharacterized cutaneous adverse reaction at insulin pump infusion sites.


Asunto(s)
Diabetes Mellitus Tipo 1 , Glucemia , Automonitorización de la Glucosa Sanguínea , Niño , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , Hipoglucemiantes/efectos adversos , Sistemas de Infusión de Insulina
19.
Pediatr Dermatol ; 38(3): 602-605, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33724504

RESUMEN

BACKGROUND/OBJECTIVE: To characterize the relationship between the presence of enteroviral skin infection, defined as a positive skin polymerase chain reaction (PCR) test, and the nasopharyngeal (NP) respiratory pathogen panel (RPP) PCR test which includes enterovirus/rhinovirus as an analyte. METHODS: A retrospective chart review was performed on 543 subjects, age 18 years or younger, who had enterovirus (EV) skin swabs performed at an academic medical center in New York City between September 2014 and November 2019. Those patients with positive EV skin PCR were considered to have an enteroviral skin infection, and those with a negative EV skin PCR were considered not to have an enteroviral skin infection. Of those 543 children who had EV skin PCR, 170 also had an NP swab RPP performed. These NP swab RPP results were characterized as positive or negative, and if positive, it was noted if the patient was positive or negative for enterovirus/rhinovirus. The positive predictive value (PPV), negative predictive value (NPV), specificity, and sensitivity of a NP swab RPP for enteroviral skin infection were then calculated. RESULTS: An enterovirus/rhinovirus NP swab RPP had a NPV of 95%, PPV of 43%, sensitivity of 90%, and specificity of 62% for cutaneous enterovirus infection. CONCLUSION: The enteroviral skin PCR test is an assay that was validated at this institution. In clinically suspicious cases of EV, a positive NP swab RPP for enterovirus/rhinovirus is a sensitive test. A negative test is highly predictive of not having EV on the skin. Although further data are needed, given that NP swab RPP is readily available, these data may suggest that an NP swab RPP, when appropriately utilized, can support or exclude a clinical diagnosis of cutaneous enterovirus in the pediatric population.


Asunto(s)
Infecciones por Enterovirus , Enterovirus , Adolescente , Niño , Enterovirus/genética , Infecciones por Enterovirus/diagnóstico , Humanos , Lactante , Ciudad de Nueva York , Reacción en Cadena de la Polimerasa , Estudios Retrospectivos
20.
J Adv Nurs ; 77(2): 869-878, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33150622

RESUMEN

AIM: To explore the emotional impact and experiences of geriatric nurses working in nursing homes and caring for patients with coronavirus 2019 disease (COVID-19). DESIGN: This is a qualitative study with phenomenological method and data were gathered through in-depth interview. METHODS: The experiences and expectations that nurses are facing during their care duties were explored via video conference, using a semi-structured interview guide. We have followed the Consolidated criteria for reporting qualitative research COREQ. RESULTS: Interviews (N=24) were conducted with nurses from four countries (Spain, Italy, Peru, and Mexico) during April 2020. Three main categories were extracted: fear of the pandemic situation, the sense of duty and professional commitment, and emotional exhaustion. CONCLUSIONS: Regardless of the country and situation, in the face of the pandemic, dramatic situations have been experienced in nursing homes worldwide, with nursing staff feeling exhausted and overwhelmed, and reflection is urged on a global level to consider the most appropriate model of care in nursing homes.


Asunto(s)
COVID-19/epidemiología , COVID-19/enfermería , COVID-19/psicología , Enfermería Geriátrica , Atención de Enfermería/psicología , Casas de Salud , Personal de Enfermería en Hospital/psicología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Italia/epidemiología , Masculino , México/epidemiología , Persona de Mediana Edad , Pandemias , Perú/epidemiología , Investigación Cualitativa , SARS-CoV-2 , España/epidemiología
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