RESUMEN
Depletion forces are fundamental for determining the phase behavior of a vast number of materials and colloidal dispersions and have been used for the manipulation of in- and out-of-equilibrium thermodynamic states. The entropic nature of depletion forces is well understood; however, most theoretical approaches, and also molecular simulations, work quantitatively at moderate size ratios in much diluted systems since large size asymmetries and high particle concentrations are difficult to deal with. The existing approaches for integrating out the degrees of freedom of the depletant species may fail under these extreme physical conditions. Thus, the main goal of this contribution is to introduce a general physical formulation for obtaining the depletion forces even in those cases where the concentration of all species is relevant. We show that the contraction of the bare forces uniquely determines depletion interactions. Our formulation is tested by studying depletion forces in binary and ternary colloidal mixtures. We report here results for dense systems with total packing fractions of 45% and 55%. Our results open up the possibility of finding an efficient route to determine effective interactions at a finite concentration, even under non-equilibrium thermodynamic conditions.
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Entropía , TermodinámicaRESUMEN
OBJECTIVE: It is important for health care education materials to be easily understood by caretakers of children requiring craniofacial surgery. This study aimed to analyze the readability of Google search results as they pertain to "Cleft Palate Surgery" and "Palatoplasty." Additionally, the study included a search from several locations globally to identify possible geographic differences. DESIGN: Google searches of the terms "Cleft Palate Surgery" and "Palatoplasty" were performed. Additionally, searches of only "Cleft Palate Surgery" were run from several internet protocol addresses globally. MAIN OUTCOME MEASURES: Flesch-Kincaid Grade Level and Readability Ease, Gunning Fog Index, Simple Measure of Gobbledygook (SMOG) index, and Coleman-Liau Index. RESULTS: Search results for "Cleft Palate Surgery" were easier to read and comprehend compared to search results for "Palatoplasty." Mean Flesch-Kincaid Grade Level scores were 7.0 and 10.11, respectively (P = .0018). Mean Flesch-Kincaid Reading Ease scores were 61.29 and 40.71, respectively (P = .0003). Mean Gunning Fog Index scores were 8.370 and 10.34, respectively (P = .0458). Mean SMOG Index scores were 6.84 and 8.47, respectively (P = .0260). Mean Coleman-Liau Index scores were 12.95 and 15.33, respectively (P = .0281). No significant differences were found in any of the readability measures based on global location. CONCLUSIONS: Although some improvement can be made, craniofacial surgeons can be confident in the online information pertaining to cleft palate repair, regardless of where the search is performed from. The average readability of the top search results for "Cleft Palate Surgery" is around the seventh-grade reading level (US educational system) and compares favorably to other health care readability analyses.
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Fisura del Paladar , Alfabetización en Salud , Cirugía Bucal , Niño , Fisura del Paladar/cirugía , Comprensión , Humanos , Internet , EsmogRESUMEN
OBJECTIVE: The aim: To investigate the clinical and pathogenetic peculiarities of formation and course of CCP and the relationship between clinical, hemodynamic and neurohumoral factors of comorbidity development in COPD combined with arterial hypertension (AH). PATIENTS AND METHODS: Materials and methods: The object of the study were 484 patients with COPD. Among them, 350 patients with CCP as a result of cardiac insufficiency/severe congestive heart failure (COPD III-IV) out of aggravation, combined with AH II stage (non-symptomatic organ damage) and 1 - 3 grades, including 55 patients (43 men, 12 women) with compensated CCP (average age 43.7 ± 3.4 years), and 295 patients (212 men and 83 women) with decompensated CCP and chronic heart failure (CHF), average age 63.2 ± 8.9 years. RESULTS: Results: It was found that the development and progression of the left and right CHF in patients with CCP combined with AH occurs due to the disorders of the central hemodynamic, progression of pulmonary hypertension, bronchial obstruction syndrome, neurohumoral and systemic immunoinflammatory activation, disorders of endothelial regulation of vascular tension, overproduction of epithelial and mitogenic growth factors, inducers of apoptosis, and is accompanied by increasing levels of natriuretic peptides. CONCLUSION: Conclusions: The main pathogenetic formation mechanisms of the heart failure on the background of CCP combined with AH are: neurohumoral and systematic immune-inflammatory activation with the development of endothelial dysfunction and (neo)angiogenesis, induction of pathological apoptosis, increase in the intrathoracic pressure, and deposition of blood in the extrathoracic tissues, which result in pulmonary and systemic hypertension, metabolic and hemodynamic remodelling and heart dysfunction.
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Insuficiencia Cardíaca , Hipertensión Pulmonar , Hipertensión , Enfermedad Pulmonar Obstructiva Crónica , Adulto , Anciano , Femenino , Insuficiencia Cardíaca/complicaciones , Hemodinámica , Humanos , Hipertensión/complicaciones , Hipertensión Pulmonar/complicaciones , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/complicacionesRESUMEN
The iron chelator, deferoxamine (DFO), has been shown to potentially improve dermal radiation-induced fibrosis (RIF) in mice through increased angiogenesis and reduced oxidative damage. This preclinical study evaluated the efficacy of two DFO administration modalities, transdermal delivery and direct injection, as well as temporal treatment strategies in relation to radiation therapy to address collateral soft tissue fibrosis. The dorsum of CD-1 nude mice received 30 Gy radiation, and DFO (3 mg) was administered daily via patch or injection. Treatment regimens were prophylactic, during acute recovery, post-recovery, or continuously throughout the experiment (n = 5 per condition). Measures included ROS-detection, histology, biomechanics and vascularity changes. Compared with irradiated control skin, DFO treatment decreased oxidative damage, dermal thickness and collagen content, and increased skin elasticity and vascularity. Metrics of improvement in irradiated skin were most pronounced with continuous transdermal delivery of DFO. In summary, DFO administration reduces dermal fibrosis induced by radiation. Although both treatment modalities were efficacious, the transdermal delivery showed greater effect than injection for each temporal treatment strategy. Interestingly, the continuous patch group was more similar to normal skin than to irradiated control skin by most measures, highlighting a promising approach to address detrimental collateral soft tissue injury following radiation therapy.
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Deferoxamina/farmacología , Dermis/metabolismo , Dermis/patología , Dermis/efectos de la radiación , Radiación Ionizante , Animales , Biomarcadores , Dermis/irrigación sanguínea , Susceptibilidad a Enfermedades , Femenino , Fibrosis , Ratones , Microvasos/diagnóstico por imagen , Microvasos/metabolismo , Estrés Oxidativo , Síndrome de Fibrosis por Radiación/etiología , Síndrome de Fibrosis por Radiación/metabolismo , Síndrome de Fibrosis por Radiación/patología , Especies Reactivas de Oxígeno/metabolismoRESUMEN
The aim of this study was to explore the therapeutic effects of fat grafting on radiation-induced hind limb contracture. Radiation therapy (RT) is used to palliate and/or cure a range of malignancies but causes inevitable and progressive fibrosis of surrounding soft tissue. Pathological fibrosis may lead to painful contractures which limit movement and negatively impact quality of life. Fat grafting is able to reduce and/or reverse radiation-induced soft tissue fibrosis. We explored whether fat grafting could improve extensibility in irradiated and contracted hind limbs of mice. Right hind limbs of female 60-day-old CD-1 nude mice were irradiated. Chronic skin fibrosis and limb contracture developed. After 4 weeks, irradiated hind limbs were then injected with (a) fat enriched with stromal vascular cells (SVCs), (b) fat only, (c) saline, or (d) nothing (n = 10/group). Limb extension was measured at baseline and every 2 weeks for 12 weeks. Hind limb skin then underwent histological analysis and biomechanical strength testing. Irradiation significantly reduced limb extension but was progressively rescued by fat grafting. Fat grafting also reduced skin stiffness and reversed the radiation-induced histological changes in the skin. The greatest benefits were found in mice injected with fat enriched with SVCs. Hind limb radiation induces contracture in our mouse model which can be improved with fat grafting. Enriching fat with SVCs enhances these beneficial effects. These results underscore an attractive approach to address challenging soft tissue fibrosis in patients following RT.
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Tejido Adiposo/trasplante , Contractura/etiología , Miembro Posterior/patología , Traumatismos Experimentales por Radiación/terapia , Animales , Femenino , Humanos , Ratones , Ratones DesnudosRESUMEN
Depletion interactions between colloidal particles surrounded by smaller depletants are typically characterized by a strong attraction at contact and a moderately repulsive barrier in front of it that extends at distances similar to the size of the depletants; the appearance and height of the barrier basically depend on the concentration and, therefore, the correlation between depletants. From a thermodynamic point of view, the former can drive the system to phase separation or toward non-equilibrium states, such as gel-like states, but its effects on both local and global properties may be controlled by the latter, which acts as a kind of entropic gate. However, the latter has not been entirely analyzed and understood within the context of colloidal mixtures mainly driven by entropy. In this contribution, we present a systematic study of depletion forces in ternary mixtures of hard spherical particles with two species of depletants, in two and three dimensions. We focus the discussion on how the composition of the depletants becomes the main physical parameter that drives the competition between the attractive well and the repulsive barrier. Our results are obtained by means of the integral equation theory of depletion forces and techniques of contraction of the description adapted to molecular dynamics computer simulations.
RESUMEN
In this study, six curcuminoids containing a tert-butoxycarbonyl (Boc) piperidone core were successfully synthesized, five of them are novel compounds reported here for the first time. These compounds were prepared through an aldolic condensation by adding tetrahydropyranyl-protected benzaldehydes or substituted benzaldehyde to a reaction mixture containing 4-Boc-piperidone and lithium hydroxide in an alcoholic solvent. A 44-94% yield was obtained supporting the developed methodology as a good strategy for the synthesis of 4-Boc-piperidone chalcones. Cytotoxic activity against LoVo and COLO 205 human colorectal cell lines was observed at GI50 values that range from 0.84 to 34.7⯵g/mL, while in PC3 and 22RV1 human prostate cancer cell lines, GI50 values ranging from 17.1 to 22.9⯵g/mL were obtained. Results from biochemical assays suggest that the cytotoxicity of the 4-Boc-piperidone chalcones can be linked to their ability to induce apoptosis, decrease the activity of NFκB and cellular proliferation. Our findings strongly support the potential of Boc-piperidone chalcones as novel cytotoxic agents against highly-metastatic cancer cells.
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Antineoplásicos/uso terapéutico , Chalconas/síntesis química , Neoplasias/tratamiento farmacológico , Piperidonas/síntesis química , Antineoplásicos/farmacología , Línea Celular Tumoral , Humanos , Relación Estructura-ActividadRESUMEN
Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.
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Antiprotozoarios/farmacología , Organismos Acuáticos/química , Productos Biológicos/farmacología , Infecciones por Euglenozoos/tratamiento farmacológico , Malaria Falciparum/tratamiento farmacológico , Enfermedades Desatendidas/tratamiento farmacológico , Animales , Antiprotozoarios/uso terapéutico , Productos Biológicos/uso terapéutico , Descubrimiento de Drogas , Resistencia a Medicamentos , Infecciones por Euglenozoos/parasitología , Ensayos Analíticos de Alto Rendimiento , Humanos , Malaria Falciparum/parasitología , Enfermedades Desatendidas/parasitología , Plasmodium falciparum/efectos de los fármacos , Plasmodium malariae/efectos de los fármacos , Plasmodium malariae/patogenicidad , Trypanosomatina/efectos de los fármacosRESUMEN
Bacterial conjugation is a key mechanism by which bacteria acquire antibiotic resistance. Therefore, conjugation inhibitors (COINs) are promising compounds in the fight against the spread of antibiotic resistance genes among bacteria. Unsaturated fatty acids (uFAs) and alkynoic fatty acid derivatives, such as 2-hexadecanoic acid (2-HDA), have been reported previously as being effective COINs. The traffic ATPase TrwD, a VirB11 homolog in plasmid R388, is the molecular target of these compounds, which likely affect binding of TrwD to bacterial membranes. In this work, we demonstrate that COINs are abundantly incorporated into Escherichia coli membranes, replacing palmitic acid as the major component of the membrane. We also show that TrwD binds palmitic acid, thus facilitating its interaction with the membrane. Our findings also suggest that COINs bind TrwD at a site that is otherwise occupied by palmitic acid. Accordingly, molecular docking predictions with palmitic acid indicated that it shares the same binding site as uFAs and 2-HDA, although it differs in the contacts involved in this interaction. We also identified 2-bromopalmitic acid, a palmitate analog that inhibits many membrane-associated enzymes, as a compound that effectively reduces TrwD ATPase activity and bacterial conjugation. Moreover, we demonstrate that 2-bromopalmitic and palmitic acids both compete for the same binding site in TrwD. Altogether, these detailed findings open up a new avenue in the search for effective synthetic inhibitors of bacterial conjugation, which may be pivotal for combating multidrug-resistant bacteria.
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Adenosina Trifosfatasas/metabolismo , Alquinos/farmacología , Antibacterianos/farmacología , Conjugación Genética/efectos de los fármacos , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Ácidos Grasos Insaturados/farmacología , Ácido Palmítico/farmacología , Alquinos/química , Sitios de Unión , Cristalografía por Rayos X , Escherichia coli/efectos de los fármacos , Simulación del Acoplamiento MolecularRESUMEN
The brain-specific tyrosine phosphatase, STEP (STriatal-Enriched protein tyrosine Phosphatase) is an important regulator of synaptic function. STEP normally opposes synaptic strengthening by increasing N-methyl D-aspartate glutamate receptor (NMDAR) internalization through dephosphorylation of GluN2B and inactivation of the kinases extracellular signal-regulated kinase 1/2 and Fyn. Here we show that STEP61 is elevated in the cortex in the Nrg1+/- knockout mouse model of schizophrenia (SZ). Genetic reduction or pharmacological inhibition of STEP prevents the loss of NMDARs from synaptic membranes and reverses behavioral deficits in Nrg1+/- mice. STEP61 protein is also increased in cortical lysates from the central nervous system-specific ErbB2/4 mouse model of SZ, as well as in human induced pluripotent stem cell (hiPSC)-derived forebrain neurons and Ngn2-induced excitatory neurons, from two independent SZ patient cohorts. In these selected SZ models, increased STEP61 protein levels likely reflect reduced ubiquitination and degradation. These convergent findings from mouse and hiPSC SZ models provide evidence for STEP61 dysfunction in SZ.
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Proteínas Tirosina Fosfatasas/fisiología , Esquizofrenia/metabolismo , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurregulina-1/genética , Neuronas/metabolismo , Fosforilación , Proteínas Tirosina Fosfatasas/genética , Ratas , Receptores de N-Metil-D-Aspartato/metabolismo , Esquizofrenia/genética , UbiquitinaciónRESUMEN
Vegetation health assessment by using airborne multispectral images throughout crop production cycles, among other precision agriculture technologies, is an important tool for modern agriculture practices. However, to really take advantage of crop fields imagery, specialized analysis techniques are needed. In this paper we present a geographic object-based image analysis (GEOBIA) approach to examine a set of very high resolution (VHR) multispectral images obtained by the use of small unmanned aerial vehicles (UAVs), to evaluate plant health states and to generate cropland maps for Capsicum annuum L. The scheme described here integrates machine learning methods with semi-automated training and validation, which allowed us to develop an algorithmic sequence for the evaluation of plant health conditions at individual sowing point clusters over an entire parcel. The features selected at the classification stages are based on phenotypic traits of plants with different health levels. Determination of areas without data dependencies for the algorithms employed allowed us to execute some of the calculations as parallel processes. Comparison with the standard normalized difference vegetation index (NDVI) and biological analyses were also performed. The classification obtained showed a precision level of about 95 % in discerning between vegetation and non-vegetation objects, and clustering efficiency ranging from 79 % to 89 % for the evaluation of different vegetation health categories, which makes our approach suitable for being incorporated at C. annuum crop's production systems, as well as to other similar crops. This methodology can be reproduced and adjusted as an on-the-go solution to get a georeferenced plant health estimation.
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Capsicum/fisiología , Productos Agrícolas/fisiología , Geografía , Procesamiento de Imagen Asistido por Computador , Análisis Espectral , Algoritmos , Funciones de Verosimilitud , Mortierella/crecimiento & desarrollo , Fenotipo , Reproducibilidad de los Resultados , SueloRESUMEN
OBJECTIVE: Introduction: Modern strategies of STEMI/NSTEMI management, that include revascularization by coronary stenting, bypass grafting, nowadays are used in 30-40% of urgent patients of such category. The prevalent part of patients is treated by administration of the optimal drug therapy. The aim of the research was to study the influence of trimetazidine and levocarnitine on the clinical course of STEMI/NSTEMI. PATIENTS AND METHODS: Materials and methods: 100 patients with STEMI/NSTEMI were included into the research. Depending on the therapy scheme, patients were divided into three groups and the control one. Determination of the key parameters was performed initially after hospitalization and at the day of patient discharge. RESULTS: Results: Promising results were shown while slowing the myocardial fibrosing. Limiting of the infarcted and `stunned` myocardium area resulted in ejection fraction increase, increase of the myocardial reserve, measured by echocardiographic indexes. CONCLUSION: Conclusions: Decreasing of myocardial fibrosing can be potentiated by the pharmacological postconditioning as well as limiting of the necrotic myocardium area and increase of viable myocardium area. Pharmacological postconditioning is effective and save, that can be proved by the absence of any serious complications.
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Infarto del Miocardio , Fibrosis , Humanos , Resultado del Tratamiento , TrimetazidinaRESUMEN
The increasing bacterial resistance against conventional antibiotics has led to the search for new antimicrobial drugs with different modes of action. Cationic antimicrobial peptides (AMPs) and lipopeptides are promising candidates to treat infections because they act on bacterial membranes causing rapid destruction of sensitive bacteria. In this study, a decapeptide named A2 (IKQVKKLFKK) was conjugated at the N-terminus with saturated, unsaturated, methoxylated and methyl -branched fatty acids of different chain lengths (C8 - C20), the antimicrobial and structural properties of the lipopeptides being then investigated. The attachment of the fatty acid chain significantly improved the antimicrobial activity of A2 against bacteria, and so, endowed it with moderated antifungal activity against yeast strains belonging to genus Candida. Lipopeptides containing hydrocarbon chain lengths between C8 and C14 were the best antibacterial compounds (MIC = 0.7 to 5.8 µM), while the most active compounds against yeast were A2 conjugated with methoxylated and enoic fatty acids (11.1 to 83.3 µM). The improvement in antimicrobial activity was mainly related to the amphipathic secondary structure adopted by A2 lipopeptides in the presence of vesicles that mimic bacterial membranes. Peptide conjugation with long hydrocarbon chains (C12 or more), regardless of their structure, significantly increased toxicity towards eukaryotic cells, resulting in a loss of selectivity. These findings suggest that A2-derived lipopeptides are potential good candidates for the treatment of infectious diseases caused by bacteria and opportunistic pathogenic yeast belonging to genus Candida. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
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Antibacterianos/química , Antifúngicos/química , Péptidos Catiónicos Antimicrobianos/química , Ácidos Grasos/química , Lipopéptidos/química , Secuencia de Aminoácidos , Antibacterianos/farmacología , Antifúngicos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Candida/efectos de los fármacos , Candida/crecimiento & desarrollo , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/crecimiento & desarrollo , Hemólisis/efectos de los fármacos , Humanos , Lipopéptidos/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Secundaria de Proteína , Especificidad de la Especie , Relación Estructura-ActividadRESUMEN
The first synthesis of C5-curcumin-fatty acid (C5-Curc-FA) conjugates was successfully performed. Through a two-step synthetic route, 10 analogs were synthesized for a structure-activity relationship (SAR) study. It was found that C5-Curc-FA conjugates containing either decanoic acid or palmitic acid moieties were cytotoxic against colorectal adenocarcinoma cell (CCL-229) at IC50s ranging from 22.5 to 56.1µg/mL, being 5c the most active C5-Curc-FA conjugate. Our results strongly suggests that a decanoic acid moiety at the meta position in C5-Curc-FA conjugates is important for their anticancer activity effect. Possible mechanisms for the anticancer activity of C5-Curc-FA conjugates were also investigated including apoptosis induction, mitochondrial damage and caspases activation. It was shown that 5c inhibited the luminescence activity of NFκB, a key signaling molecule involved in cell apoptosis and cell proliferation, at IC50=18.2µg/mL. In addition, it was demonstrated that 5c displayed significant apoptotic effect at GI50=46.0µg/mL in colorectal adenocarcinoma cell line (ATCC CCL-222), which can be explained by the significant mitochondrial membrane permeabilization and caspases 3 and 7 activation effect of 5c. Finally, it was investigated that C5-Curc-FA conjugates can affect the replication process of cancer cells, since compounds 5c, 5e, and 6c inhibited the relaxing activity of the human DNA topoisomerase I at minimum inhibitory concentrations (MICs) that range from 50 to 250µg/mL. Our results strongly support the hypothesis that the inhibition of both NFκB and DNA topoisomerase I by C5-Curc-FA conjugates is associated with their anticancer activity.
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Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Curcumina/química , Ácidos Grasos/química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , HumanosRESUMEN
The first total synthesis of a C5-curcumin-2-hexadecynoic acid (C5-Curc-2-HDA, 6) conjugate was successfully performed. Through a three-step synthetic route, conjugate 6 was obtained in 13% overall yield and tested for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Our results revealed that 6 was active against eight MRSA strains at MICs that range between 31.3 and 62.5 µg/mL. It was found that the presence of 2-hexadecynoic acid (2-HDA, 4) in conjugate 6 increased 4-8-fold its antibacterial activity against MRSA strains supporting our hypothesis that the chemical connection of 4 to C5-curcumin (2) increases the antibacterial activity of 2 against Gram-positive bacteria. Combinational index (CIn) values that range between 1.6 and 2.3 were obtained when eight MRSA strains were treated with an equimolar mixture of 2 and 4. These results demonstrated that an antagonistic effect is taking place. Finally, it was investigated whether conjugate 6 can affect the replication process of S. aureus, since this compound inhibited the supercoiling activity of the S. aureus DNA gyrase at minimum inhibitory concentrations (MIC) of 250 µg/mL (IC50=100.2±13.9 µg/mL). Moreover, it was observed that the presence of 4 in conjugate 6 improves the anti-topoisomerase activity of 2 towards S. aureus DNA gyrase, which is in agreement with results obtained from antibacterial susceptibility tests involving MRSA strains.
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Alquinos/farmacología , Antibacterianos/farmacología , Curcumina/análogos & derivados , ADN Superhelicoidal/química , ADN Superhelicoidal/farmacología , Ácidos Grasos Insaturados/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Alquinos/química , Animales , Antibacterianos/síntesis química , Antibacterianos/toxicidad , Chlorocebus aethiops , Curcumina/síntesis química , Curcumina/farmacología , Curcumina/toxicidad , Girasa de ADN/química , Escherichia coli/efectos de los fármacos , Ácidos Grasos Insaturados/química , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Staphylococcus aureus/enzimología , Inhibidores de Topoisomerasa II/síntesis química , Inhibidores de Topoisomerasa II/farmacología , Inhibidores de Topoisomerasa II/toxicidad , Células VeroRESUMEN
CD44 is a complex family of molecules, associated with aggressive malignancies and cancer stem cells. However, the role of CD44 variants in tumor progression and treatment resistance is not clear. In this study, the expression of CD44 and its variants was assessed in head and neck squamous cell carcinomas (HNSCC). Furthermore, subpopulations of cells expressing high amounts of CD44 variants were identified and characterized, for e.g., cell cycle phase and radioresistance. Results revealed high and homogenous CD44 and CD44v7 expression in four cell lines and CD44v4 and CD44v6 in three cell lines. CD44v3 was highly expressed in two cell lines, whereas CD44v5, CD44v7/8, CD44v10, CD133, and CD24 demonstrated no or moderate expression. Moreover, a subpopulation of very high CD44v4 expression was identified, which is independent of cell phase, demonstrating increased proliferation and radioresistance. In cell starvation experiments designed to enrich for cancer stem cells, a large population with dramatically increased expression of CD44, CD44v3, CD44v6, and CD44v7 was formed. Expression was independent of cell phase, and cells demonstrated increased radioresistance and migration rate. Our results demonstrate that the heterogeneity of tumor cells has important clinical implications for the treatment of HNSCC and that some of the CD44 variants may be associated with increased radioresistance. Highly expressed CD44 variants could make interesting candidates for selective cancer targeting.
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Carcinoma de Células Escamosas/metabolismo , Neoplasias de Cabeza y Cuello/metabolismo , Receptores de Hialuranos/metabolismo , Línea Celular Tumoral , Separación Celular , Citometría de Flujo , Humanos , Isoformas de Proteínas , Tolerancia a Radiación/fisiologíaRESUMEN
The malaria parasite Plasmodium goes through two life stages in the human host, a non-symptomatic liver stage (LS) followed by a blood stage with all clinical manifestation of the disease. In this study, we investigated a series of 2-alkynoic fatty acids (2-AFAs) with chain lengths between 14 and 18 carbon atoms for dual in vitro activity against both life stages. 2-Octadecynoic acid (2-ODA) was identified as the best inhibitor of Plasmodium berghei parasites with ten times higher potency (IC50=0.34 µg/ml) than the control drug. In target determination studies, the same compound inhibited three Plasmodium falciparum FAS-II (PfFAS-II) elongation enzymes PfFabI, PfFabZ, and PfFabG with the lowest IC50 values (0.28-0.80 µg/ml, respectively). Molecular modeling studies provided insights into the molecular aspects underlying the inhibitory activity of this series of 2-AFAs and a likely explanation for the considerably different inhibition potentials. Blood stages of P. falciparum followed a similar trend where 2-ODA emerged as the most active compound, with 20 times less potency. The general toxicity and hepatotoxicity of 2-AFAs were evaluated by in vitro and in vivo methods in mammalian cell lines and zebrafish models, respectively. This study identifies 2-ODA as the most promising antiparasitic 2-AFA, particularly towards P. berghei parasites.
Asunto(s)
Antimaláricos/farmacología , Acido Graso Sintasa Tipo II/antagonistas & inhibidores , Ácidos Grasos Insaturados/farmacología , Malaria/tratamiento farmacológico , Malaria/parasitología , Plasmodium berghei/enzimología , Plasmodium falciparum/enzimología , Animales , Antimaláricos/síntesis química , Antimaláricos/química , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Acido Graso Sintasa Tipo II/metabolismo , Ácidos Grasos Insaturados/síntesis química , Ácidos Grasos Insaturados/química , Humanos , Modelos Moleculares , Plasmodium berghei/efectos de los fármacos , Plasmodium falciparum/efectos de los fármacos , Relación Estructura-Actividad , Pez CebraRESUMEN
The environmental impact of agricultural waste from the processing of food and feed crops is an increasing concern worldwide. Concerted efforts are underway to develop sustainable practices for the disposal of residues from the processing of such crops as coffee, sugarcane, or corn. Coffee is crucial to the economies of many countries because its cultivation, processing, trading, and marketing provide employment for millions of people. In coffee-producing countries, improved technology for treatment of the significant amounts of coffee waste is critical to prevent ecological damage. This mini-review discusses a multi-stage biorefinery concept with the potential to convert waste produced at crop processing operations, such as coffee pulping stations, to valuable biofuels and bioproducts using biochemical and thermochemical conversion technologies. The initial bioconversion stage uses a mutant Kluyveromyces marxianus yeast strain to produce bioethanol from sugars. The resulting sugar-depleted solids (mostly protein) can be used in a second stage by the oleaginous yeast Yarrowia lipolytica to produce bio-based ammonia for fertilizer and are further degraded by Y. lipolytica proteases to peptides and free amino acids for animal feed. The lignocellulosic fraction can be ground and treated to release sugars for fermentation in a third stage by a recombinant cellulosic Saccharomyces cerevisiae, which can also be engineered to express valuable peptide products. The residual protein and lignin solids can be jet cooked and passed to a fourth-stage fermenter where Rhodotorula glutinis converts methane into isoprenoid intermediates. The residues can be combined and transferred into pyrocracking and hydroformylation reactions to convert ammonia, protein, isoprenes, lignins, and oils into renewable gas. Any remaining waste can be thermoconverted to biochar as a humus soil enhancer. The integration of multiple technologies for treatment of coffee waste has the potential to contribute to economic and environmental sustainability.
Asunto(s)
Biocombustibles , Residuos Industriales , Biotecnología/métodos , Biotransformación , Café , Manipulación de Alimentos/métodos , Kluyveromyces/crecimiento & desarrollo , Kluyveromyces/metabolismo , Rhodotorula/crecimiento & desarrollo , Rhodotorula/metabolismo , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Saccharum , Yarrowia/crecimiento & desarrollo , Yarrowia/metabolismo , Zea maysRESUMEN
Chromobacterium violaceum is commonly found in soil and freshwater within tropical and subtropical regions. Although not a common occurrence, this bacterium has the potential to cause severe diseases in humans and animals, such as liver and lung abscesses and septicemia. Herein we report the synthesis of novel N-acyl homoserine lactones (HSLs) to evaluate their effectiveness as antiquorum sensing (anti-QS) agents in C. violaceum. The HSLs were prepared through three synthetic approaches, where hexanoic acid, decanoic acid, 6-decynoic acid, or 2-hexadecynoic acid (2-HDA) was treated with commercially available l-homoserine lactone (HSL) hydrobromide in either dichloromethane or tetrahydrofuran in the presence of EDC and DMAP. The effectiveness of HSLs as anti-QS agents was assessed through susceptibility tests and violacein quantification. The most effective anti-QS inhibitor among all N-acyl-HSLs tested was the N-(2-hexadecynoyl)-l-homoserine lactone (HSL 4). Further experimental approaches, such as quantification of acyl-homoserine lactones and biofilm inhibitory tests, were carried out to determine the effect of HSL 4 on these QS-dependent mechanisms. These experiments showed that HSL 4 was highly effective at inhibiting the production of HSLs and biofilm in C. violaceum at 0.25, 0.50, and 1 mg/mL. In addition, the cytotoxicity activity was evaluated against Vero cells to determine the selectivity of HSL 4 as a nontraditional antibacterial agent. HSL 4 was not toxic against Vero cells at concentrations ranging from 0.0039 to 1 mg/mL. Molecular docking experiments were conducted to study the interactions between novel HSLs and CviR (PDB ID 3QP5), a receptor that plays a significant role in C. violaceum QS. In silico studies indicate that HSL 4 exhibits better interactions with Leu 72 and Gln 95 of the CviR binding pocket when compared to the other analogs. These results validate previous in vitro studies, such as susceptibility tests and violacein production assays. The findings above indicate that novel acetylenic HSLs may potentially be agents that combat bacterial communication and biofilm formation. However, further investigation is necessary to expand the spectrum of bacterial strains capable of resisting antibiotics through QS and evaluate the compounds' cytotoxicity in other cell lines.
RESUMEN
Skin fibrosis is a clinical problem with devastating impacts but limited treatment options. In the setting of diabetes, insulin administration often causes local dermal fibrosis, leading to a range of clinical sequelae including impeded insulin absorption. Mechanical forces are important drivers of fibrosis and, clinically, physical tension offloading at the skin level using an elastomeric patch significantly reduces wound scarring. However, it is not known whether tension offloading could similarly prevent skin fibrosis in the setting of pro-fibrotic injections. Here, we develop a porcine model using repeated local injections of bleomycin to recapitulate key features of insulin-induced skin fibrosis. Using histologic, tissue ultrastructural, and biomechanical analyses, we show that application of a tension-offloading patch both prevents and rescues existing skin fibrosis from bleomycin injections. By applying single-cell transcriptomic analysis, we find that the fibrotic response to bleomycin involves shifts in myeloid cell dynamics from favoring putatively pro-regenerative to pro-fibrotic myeloid subtypes; in a mechanomodulatory in vitro platform, we show that these shifts are mechanically driven and reversed by exogenous IL4. Finally, using a human foreskin xenograft model, we show that IL4 treatment mitigates bleomycin-induced dermal fibrosis. Overall, this study highlights that skin tension offloading, using an FDA cleared, commercially available patch, could have significant potential clinical benefit for the millions of patients dependent on insulin.