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The clinical course of COVID-19 may show severe presentation, potentially involving dynamic cytokine storms and T cell lymphopenia, which are leading causes of death in patients with SARS-CoV-2 infection. Plasma exchange therapy (PLEX) effectively removes pro-inflammatory factors, modulating and restoring innate and adaptive immune responses. This clinical trial aimed to evaluate the impact of PLEX on the survival of patients with severe SARS-CoV-2 and the effect on the cytokine release syndrome. Hospitalized patients diagnosed with SARS-CoV-2 infection and cytokine storm syndrome were selected to receive 2 sessions of PLEX or standard therapy. Primary outcome was all-cause 60-days mortality; secondary outcome was requirement of mechanical ventilation, SOFA, NEWs-2 scores modification, reduction of pro-inflammatory biomarkers and hospitalization time. Twenty patients received PLEX were compared against 40 patients receiving standard therapy. PLEX reduced 60-days mortality (50% vs 20%; OR 0.25, 95%CI 0.071-0.880; p = 0.029), and this effect was independent from demographic variables and drug therapies used. PLEX significantly decreased SOFA, NEWs-2, pro-inflammatory mediators and increased lymphocyte count, accompanied with a trend to reduce affected lung volume, without effect on SatO2/FiO2 indicator or mechanical ventilation requirement. PLEX therapy provided significant benefits of pro-inflammatory clearance and reduction of 60-days mortality in selected patients with COVID-19, without significant adverse events.
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COVID-19 , Humanos , COVID-19/terapia , Tratamiento Farmacológico de COVID-19 , Intercambio Plasmático , Respiración Artificial , SARS-CoV-2RESUMEN
In the past decade, new strategies have been developed to control the Aedes aegypti (Diptera: Culicidae) mosquito vector, as well as a broad range of arboviral agents. Vector control surveillance programmes in Puerto Rico and Australia have implemented the Centers for Disease Control and Prevention autocidal gravid ovitrap (AGO), which has had an impact on vector density and, consequently, the epidemiology of arboviral infections. Colombia intends to establish the AGO as a new tool for the surveillance and control of the A. aegypti vector. AGOs were evaluated in a hyperendemic area for dengue virus during an 8-week period in Villavicencio city, eastern Colombia. The results indicated that the AGOs detect a high density of A. aegypti, with positive results for these traps of over 80% and an average catch of six individuals per trap per week. Acceptance of AGOs in the community exceeded 95%, and adherence was around 89%. This study's results demonstrate, for the first time in Colombia, that traps are a useful tool for the surveillance of A. aegypti. Future studies must consider the implementation of AGOs in the region.
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Aedes , Control de Mosquitos/métodos , Aedes/virología , Animales , Colombia/epidemiología , Dengue/transmisión , Virus del Dengue , Mosquitos Vectores/virologíaRESUMEN
RESUMEN Introducción: Uno de los parámetros más importantes asociados a la producción de leche y su transformación es contar con condiciones higiénico-sanitarias adecuadas que permitan mejorar las condiciones del productor y empresas transformadoras y, por ende, garantizar inocuidad alimentaria al consumidor garantizando su bienestar y salud. Objetivo: Se evaluaron características composicionales, microbiológicas y sanitarias de leche cruda durante el segundo tercio de lactancia en vacas lecheras. Materiales y métodos: Se tomaron muestras de leche por duplicado cada 10 días a siete vacas lecheras durante su segundo tercio de lactancia. Posteriormente, se realizaron las siguientes pruebas: análisis composicional, adulterantes, presencia de antibióticos, recuento de células somáticas (RCS/ ml), identificación de Staphylococcus aureus y antibiograma por el método de Kirby-Bauer. Resultados: Se detectó la presencia de Staphylococcus aureus en el 66,2% de las muestras y 4,6% resultaron positivas para Listeria sp. No hubo presencia de antibióticos, peróxidos y almidones. Se evidenciaron muestras positivas para cloruros y neutralizantes, además se determinó que por cada kilogramo de leche se obtiene 30, 25 y 84 g de proteína, caseína y sólidos no grasos (SNG), respectivamente; donde la caseína representó el 83% de la proteína. Para el caso del RCS/ml se encontraron valores superiores a un millón de RCS/ml. Conclusiones: Para el caso estudiado la calidad composicional, sanitaria y microbiológica de la leche cruda en el segundo tercio de lactancia en vacas lecheras no es adecuada debido a que se obtuvieron valores que sobrepasan algunos lineamientos de la Norma Técnica Colombiana (NTC) 399 de 2002, en la cual se establece un conteo de mesófilos y de células somáticas (RCS/ml) máximo de 700.000/ml de leche cruda, a partir del cual se debe descartar el consumo de leche o su transformación.
ABSTRACT Introduction: One of the most important parameters associated with the production of milk and its transformation, is to have adequate hygienic-sanitary conditions in terms of milk quality that allow improving the conditions of the producer and processing companies, and therefore to provide food safety to the consumers, guaranteeing their well-being and health. Objetive: Compositional, microbiological and sanitary characteristics of raw milk were evaluated during the second third of lactation in dairy cows. Materials and methods: Two milk samples were taken every 10 days from 7 dairy cows during their second third of lactation. Then the following tests were carried out: compositional analysis, adulterants, presence of antibiotics, somatic cell count (SCC/mL), identification of Staphylococcus aureus and antibiogram by the Kirby-Bauer method. Results: Staphylococcus aureus was evidenced in 66.2% of the samples, and 4.6% of them gave positive for Listeria sp. No traces of antibiotics, peroxides and starches were found. Positive samples were found for chlorides and neutralizers, and it was determined that for each kilogram of milk, 30, 25 and 84 grams of protein, casein and non-fatty solids (NFS) were obtained, with 83% of the protein formed by casein. In the case of SCC/mL, values higher than one million SCC/mL were found. Conclusions: The compositional, sanitary and microbiological quality of the studied raw milk in the second third of lactation in dairy cows was not adequate, because values found lied above the Colombian technical standard 399 of 2002, which establishes a maximum of mesophile and somatic cell count (SCC/ mL) of 700000/ml in raw milk, therefore not allowing its consumption and transformation.
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In this work we present a systematic study of ZnO micro and nanostructures grown by spray pyrolysis (SP) and by physical vapour transport (PVT) on glass and c-sapphire substrates at low temperatures. Optimised growth conditions have allowed to obtain homogeneous ZnO nanolayers composed of quasi-spherical nanoparticles in the range 2 to 8 nm by spray pyrolysis, while by PVT the selected growth conditions allow to produce a wide variety of morphologies (tripods, grains, arrows and wires) of nano and microsize dimension. Grazing incidence X-ray diffraction, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDX) were used as characterization techniques in the investigation of structural, morphological and compositional nature of these nanostructures in relation with the growth method.
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The aims of this study were to test a locally applied carvacrol gel and determine its efficacy preventing alveolar bone loss in experimental periodontitis in rats by regular methodology to validate applicability the atomic force microscopy (AFM) as a novel morphology method on this model. Wistar rats were subjected to ligature around second, upper-left molars. Animals were treated carvacrol gel topically (CAG), immediately after Experimental Periodontitis Disease induction for 1' three-times/day for 11 days. A vehicle gel was utilized as control. The periodontium and the surrounding gingivae were examined at regular histopathology and by AFM method; the neutrophil influx into the gingivae was also assayed using myeloperoxidase activity. The bacterial flora was assessed through culture of the gingival tissue. Alveolar bone loss was significantly inhibited by CAG group compared to the Vehicle (V) group, the carvacrol gel treatment reduced tissue lesion at histopathology, with preservation of the periodontium, coupled to decreased myeloperoxidase activity in gingival tissue and also prevented the proliferation of periodontal microorganisms and the weight loss. The GAC treatment preserved alveolar bone resorption and showed anti-inflammatory and antibacterial activities in experimental periodontitis. Topographical changes in histological sections were seen bringing into high relief the periodontal structures, being a simple and cost-effective method for periodontal evaluation with ultrastructural resolution.
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Pérdida de Hueso Alveolar/prevención & control , Antibacterianos/uso terapéutico , Antiinflamatorios/uso terapéutico , Encía/efectos de los fármacos , Monoterpenos/uso terapéutico , Periodontitis/tratamiento farmacológico , Periodoncio/efectos de los fármacos , Administración Tópica , Animales , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antiinflamatorios/administración & dosificación , Antiinflamatorios/farmacología , Bacterias/efectos de los fármacos , Cimenos , Modelos Animales de Enfermedad , Geles , Encía/microbiología , Encía/patología , Ligadura , Masculino , Microscopía de Fuerza Atómica/métodos , Diente Molar , Monoterpenos/administración & dosificación , Monoterpenos/farmacología , Infiltración Neutrófila/efectos de los fármacos , Periodontitis/microbiología , Periodontitis/patología , Periodoncio/patología , Peroxidasa/metabolismo , Ratas , Ratas WistarRESUMEN
OBJECTIVES: Activation of SMAD-independent p44/42 MAPK (ERK1/2) signalling by TGFbeta has been recently reported in various cell types. However, the mechanisms for the linkage between the SMAD-dependent and -independent pathways are poorly understood. In this study, we investigated whether TGF-beta activates the ERK pathway and how TGFbeta communicates with the MAP kinase signals induced by a mitogen, in human myeloid leukaemia cells. MATERIALS AND METHODS AND RESULTS: TGFbeta dramatically suppressed proliferation of MV4-11 and TF-1 cells without detectable phosphorylation of ERK1/2 and MEK1/2 for the duration of 48 h, as detected by MTT assay and Western blot analysis, respectively. In contrast, GM-CSF induced rapid and transient phosphorylation of MEK1/2 and ERK1/2 and up-regulated cell proliferation. Both GM-CSF-induced ERK1/2 activation and cell proliferation were significantly inhibited by TGFbeta. GM-CSF also induced transient phosphorylation of the p85 subunit of PI3-kinase. Corresponding to this change, phosphorylated p85 was found to bind to the GM-CSF receptor-alpha subunit, as detected by immunoprecipitation and Western blot analysis. PD98059, a selective inhibitor of MEK, blocked GM-CSF-induced phosphorylation of MEK and ERK but not p85. However, TGFbeta and LY294002, a potent inhibitor of PI3-kinase, significantly inhibited phosphorylation of both p85 and ERK1/2. CONCLUSIONS: These studies thus indicate that TGFbeta does not activate the ERK pathway but turns off the GM-CSF-induced ERK signal via inhibition of the PI3-kinase-Akt pathway, in these human leukaemia cells.
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Factor Estimulante de Colonias de Granulocitos y Macrófagos/antagonistas & inhibidores , Leucemia Mieloide/enzimología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Factor de Crecimiento Transformador beta/farmacología , Western Blotting , Línea Celular Tumoral , Proliferación Celular , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Humanos , Inmunoprecipitación , Leucemia Mieloide/patología , Fosforilación , Proteínas Recombinantes/farmacología , Transducción de SeñalRESUMEN
MicroRNAs (miRNAs) are involved in the post-transcriptional regulation of gene expression during development. This study was performed to determine gestational age-dependent changes in miRNA expression in the chorioamniotic membranes and to assess the significance of miRNAs in human pregnancy and parturition. The expression profile of 455 miRNAs was compared between patients at term without labour (TNL: n = 10), in labour (TL: n = 10), and preterm labour (PTL: n = 10) using microarrays. A total of 39 miRNAs were differentially expressed between term and preterm cases, of which 31 (79.5%) were down-regulated at term. Expression of ten miRNAs, including miR-338, differentially expressed between PTL and TL groups was decreased at term. Computational analyses using miRBase Targets have identified PLA2G4B, a phospholipase implicated in parturition, as a putative target of miR-338. Inhibition of endogenous miR-338 with anti-miR-338 increased the mRNA and protein expression of PLA2G4B in decidual cells. Luciferase assay with reporter constructs confirmed that the suppression of PLA2G4B occurs through binding of miR-338 to the 3UTR of PLA2G4B. Interestingly, the expression of Dicer, a key miRNA-processing enzyme, was markedly decreased at term, particularly with labour in the chorioamniotic membranes. Collectively, the novel findings reported herein strongly suggest that post-transcriptional regulation of genes by miRNAs, coupled with the changes of miRNA processing machinery in the chorioamniotic membranes, plays a role in pregnancy and parturition. Furthermore, the expression level of Dicer in the chorioamniotic membranes dichotomizes pathological preterm labour and physiological spontaneous labour at term.
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Amnios/metabolismo , Corion/metabolismo , MicroARNs/metabolismo , Embarazo/genética , Adolescente , Adulto , Secuencia de Bases , Peso al Nacer , Decidua/metabolismo , Regulación hacia Abajo , Femenino , Perfilación de la Expresión Génica/métodos , Edad Gestacional , Fosfolipasas A2 Grupo IV/biosíntesis , Fosfolipasas A2 Grupo IV/genética , Humanos , Cariotipificación , MicroARNs/fisiología , Datos de Secuencia Molecular , Trabajo de Parto Prematuro/genética , Trabajo de Parto Prematuro/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Parto/genética , Parto/metabolismo , Embarazo/metabolismo , Proteínas Gestacionales/genética , Proteínas Gestacionales/metabolismo , Ribonucleasa III/metabolismo , Adulto JovenRESUMEN
In Brazilian folk medicine, Lippia sidoides (Ls) and Myracrodruon urundeuva (Mu) have gained popularity and reputation as effective antimicrobial and anti-inflammatory agents. This work aimed to evaluate the effect of topical herbal gel from Ls 0.5% (v/w) and Mu 5% (w/w) in experimental periodontal disease (EPD) in rats. Wistar rats were subjected to ligature placement around the second upper left molars. Animals were treated topically with Ls and/or Mu-based gel, immediately after EPD induction and three times/day for 11 days until the rats were sacrificed (11th day). Saline-based gel was utilized as control for all experiments and doxycycline based gel 10% (w/w) was utilized as reference substance. Animals were weighed daily. Alveolar bone loss was measured as the difference (in millimeters) between the cusp tip and the alveolar bone. The periodontum and the surrounding gingivae were examined at histopathology, as well as the neutrophil influx into the gingivae was assayed using myeloperoxidase activity and cytokine production mainly tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels by ELISA method. The local bacterial flora was assessed through culture of the gingival tissue in standard aerobic and anaerobic media. Alveolar bone loss was significantly inhibited by Ls and Mu combined treatment compared to the saline control group. Ls and Mu combined treatment reduced tissue lesion at histopathology, with partial preservation of the periodontum, coupled to decreased myeloperoxidase activity as well as significantly inhibited TNF-alpha and IL-1beta production in gingival tissue compared to the saline control group. Ls and Mu combined treatment also prevented the growth of oral microorganisms and the weight loss. Ls and Mu combined based gel treatment preserved alveolar bone resorption and demonstrated anti-inflammatory and antibacterial activities in experimental periodontitis.
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Pérdida de Hueso Alveolar/tratamiento farmacológico , Anacardiaceae/química , Lippia/química , Periodontitis/tratamiento farmacológico , Aceites de Plantas/uso terapéutico , Pérdida de Hueso Alveolar/inmunología , Pérdida de Hueso Alveolar/patología , Animales , Candida albicans/efectos de los fármacos , Candida albicans/aislamiento & purificación , Geles/uso terapéutico , Encía/efectos de los fármacos , Encía/inmunología , Encía/microbiología , Interleucina-1beta/inmunología , Masculino , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Periodontitis/inmunología , Periodontitis/patología , Peroxidasa/inmunología , Extractos Vegetales/uso terapéutico , Ratas , Ratas Wistar , Streptococcus/efectos de los fármacos , Streptococcus/aislamiento & purificación , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.
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Antiinfecciosos/farmacología , Candida albicans/efectos de los fármacos , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Streptococcus/efectos de los fármacos , Cimenos , Evaluación Preclínica de Medicamentos , Cromatografía de Gases y Espectrometría de Masas , Lippia/química , Pruebas de Sensibilidad Microbiana , Monoterpenos/química , Aceites Volátiles/aislamiento & purificación , Aceites de Plantas/aislamiento & purificación , Timol/químicaRESUMEN
Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7 percent) and carvacrol (16.7 percent). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.
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Humanos , Antiinfecciosos/farmacología , Candida albicans/efectos de los fármacos , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Streptococcus/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Lippia/química , Pruebas de Sensibilidad Microbiana , Monoterpenos/química , Aceites Volátiles/aislamiento & purificación , Aceites de Plantas/aislamiento & purificación , Timol/químicaRESUMEN
An innovative and efficient genetic transformation protocol for European chestnut is described in which embryogenic cultures are used as the target material. When somatic embryos at the globular or early-torpedo stages were cocultured for 4 days with Agrobacterium tumefaciens strain EHA105 harbouring the pUbiGUSINT plasmid containing marker genes, a transformation efficiency of 25% was recorded. Murashige and Skoog culture medium containing 150 mg/l of kanamycin was used as the selection medium. The addition of acetosyringone was detrimental to the transformation efficiency. Transformation was confirmed by a histochemical beta-glucuronidase (GUS ) assay, PCR and Southern blot analyses for the uidA (GUS) and nptII (neomycin phosphotransferase II) genes. At present, 93 GUS-positive chestnut embryogenic lines are being maintained in culture. Low germination rates (6.3%) were recorded for the transformed somatic embryos. The presence of the transferred genes in leaves and shoots derived from the germinated embryos was also verified by the GUS assay and PCR analysis.
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Fagaceae/genética , Rhizobium/genética , Semillas/genética , Transformación Genética/efectos de los fármacos , Acetofenonas/farmacología , Antibacterianos/farmacología , Técnicas de Cocultivo , ADN de Plantas/análisis , Europa (Continente) , Fagaceae/crecimiento & desarrollo , Marcadores Genéticos , Técnicas Genéticas/normas , Plásmidos , Reproducibilidad de los Resultados , Semillas/crecimiento & desarrolloRESUMEN
The bacterial enzyme MurA catalyzes the transfer of enolpyruvate from phosphoenolpyruvate (PEP) to uridine diphospho-N-acetylglucosamine (UNAG), which is the first committed step of bacterial cell wall biosynthesis. From high-throughput screening of a chemical library, three novel inhibitors of the Escherichia coli MurA enzyme were identified: the cyclic disulfide RWJ-3981, the purine analog RWJ-140998, and the pyrazolopyrimidine RWJ-110192. When MurA was preincubated with inhibitor, followed by addition of UNAG and PEP, the 50% inhibitory concentrations (IC(50)s) were 0.2 to 0.9 microM, compared to 8.8 microM for the known MurA inhibitor, fosfomycin. The three compounds exhibited MICs of 4 to 32 microg/ml against Staphylococcus aureus; however, the inhibition of DNA, RNA, and protein synthesis in addition to peptidoglycan synthesis by all three inhibitors indicated that antibacterial activity was not due specifically to MurA inhibition. The presence of UNAG during the MurA and inhibitor preincubation lowered the IC(50) at least fivefold, suggesting that, like fosfomycin, the three compounds may interact with the enzyme in a specific fashion that is enhanced by UNAG. Ultrafiltration and mass spectrometry experiments suggested that the compounds were tightly, but not covalently, associated with MurA. Molecular modeling studies demonstrated that the compounds could fit into the site occupied by fosfomycin; exposure of MurA to each compound reduced the labeling of MurA by tritiated fosfomycin. Taken together, the evidence indicates that these inhibitors may bind noncovalently to the MurA enzyme, at or near the site where fosfomycin binds.
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Transferasas Alquil y Aril/metabolismo , Inhibidores Enzimáticos/farmacología , Escherichia coli/enzimología , Purinas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Compuestos de Sulfhidrilo/farmacología , Proteínas Bacterianas/biosíntesis , Cristalografía por Rayos X , Inhibidores Enzimáticos/metabolismo , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Fosfomicina/química , Fosfomicina/metabolismo , Fosfomicina/farmacología , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Datos de Secuencia Molecular , Purinas/metabolismo , Pirazoles/metabolismo , Pirimidinas/metabolismo , Relación Estructura-Actividad , Compuestos de Sulfhidrilo/metabolismoRESUMEN
Beta-lactam antibiotics such as the cephalosporins and penicillins have diminished clinical effectiveness due to the hydrolytic activity of diverse beta-lactamases, especially those in molecular classes A and C. A structure activity relationship (SAR) study of a high-throughput screening lead resulted in the discovery of a potent and selective non-beta-lactam inhibitor of class C beta-lactamases.
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Inhibidores Enzimáticos/síntesis química , Rodanina/análogos & derivados , Inhibidores de beta-Lactamasas , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Estructura Molecular , Piperacilina/antagonistas & inhibidores , Piperacilina/farmacología , Rodanina/síntesis química , Rodanina/química , Rodanina/farmacología , Relación Estructura-Actividad , beta-Lactamasas/clasificaciónRESUMEN
A multitude of extended spectrum beta-lactamases (ESBLs) have evolved in response to the use of late generation cephalosporins. In those hospitals where Klebsiella pneumoniae and other bacteria possessing these enzymes flourish, many interventions have been applied to reduce this trend. We instituted a policy of class restriction of cephalosporins in our hospital in 1996 that led to a 44% reduction in ceftazidime-resistant K. pneumoniae hospital-wide and an 87% decrease in the surgical intensive care unit. Another interesting outcome of this strategy was the identification of multiresistant K. pneumoniae, which was now susceptible to ceftazidime. Characterization of these novel isolates demonstrated that the TEM-26 enzyme, which was responsible for ceftazidime resistance in our earlier described outbreak, was lacking in most of the isolates examined. Among the remaining ceftazidime-resistant K. pneumoniae, TEM-26 was also absent, and new enzymes that hydrolyze ceftazidime were detected. Loss of ceftazidime-hydrolyzing beta-lactamases was observed after in vitro passage of ceftazidime-resistant K. pneumoniae on antibiotic-free media. These findings suggest that class restriction of cephalosporins may increase susceptibility among extended-spectrum beta-lactamase-producing pathogens.
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Ceftazidima/farmacología , Cefalosporinas/farmacología , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , beta-Lactamasas/genética , Ceftazidima/uso terapéutico , Cefalosporinas/uso terapéutico , Infección Hospitalaria/microbiología , Farmacorresistencia Microbiana/genética , Resistencia a Múltiples Medicamentos/genética , Electroforesis en Gel de Campo Pulsado , Humanos , Focalización Isoeléctrica , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/fisiología , beta-Lactamasas/metabolismoRESUMEN
A new member of the pluramycin class of antibiotics, gamma-indomycinone [1], has been isolated along with the known compounds rubiflavinone C-1 [2] and beta-indomycinone [3] from the culture broth of a Streptomyces sp. obtained from a deep-sea sediment core. Each compound is composed of an anthraquinone-gamma-pyrone nucleus, but bears a different side-chain. Compounds 2 and 3 were identified by comparison of their spectral data with published data, while gamma-indomycinone [1] was characterized using 1H-nmr and mass spectrometry.
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Antibióticos Antineoplásicos/aislamiento & purificación , Streptomyces/química , Antraquinonas/aislamiento & purificación , Antraquinonas/farmacología , Antibióticos Antineoplásicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Pironas/aislamiento & purificación , Pironas/farmacología , Células Tumorales CultivadasRESUMEN
An actinomycete strain designated LL-31F508 was isolated from an intertidal sediment sample collected in Key West, Florida. Culture LL-31F508 was assigned to the Streptomyces genus based on the presence of LL-diaminopimelic acid (DAP) in the cell wall and observations of spiny spores using scanning electron microscopy (SEM). Excellent antimicrobial activity against Staphylococcus and Enterococcus spp. were detected in both the supernatant and cell extract samples from fermentations of culture LL-31F508. Production of antibiotic activity peaked at 48-50 hours and closely paralleled cell growth, during which time glucose was more rapidly assimilated than dextrin. A series of new antibiotics called the bioxalomycins was identified as the antibacterial products from fermentations of this culture. Fermentation conditions for production of bioxalomycin alpha differed substantially from those required for production of a related compound, naphthyridinomycin, by the reference culture Streptomyces lusitanus NRRL 8034.
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Antibacterianos/biosíntesis , Oxazoles/aislamiento & purificación , Streptomyces/metabolismo , Antibacterianos/farmacología , Fermentación , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Oxazoles/farmacología , Streptomyces/clasificación , Streptomyces/ultraestructuraRESUMEN
Actinomycete culture LL-D37187 has been found to produce the new polyether antibiotic martinomycin. Taxonomic studies, including morphological, physiological, and cell wall chemistry analyses, revealed that culture LL-D37187 is a novel streptomycete species, and the proposed name is Streptomyces salvialis. Martinomycin exhibits activity against the Southern Army Worm (Spodoptera eridania) and Gram-positive bacteria.
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Antibacterianos/biosíntesis , Streptomyces/metabolismo , Animales , Antibacterianos/farmacología , Artemia/efectos de los fármacos , Éteres/farmacología , Fermentación , Bacterias Grampositivas/efectos de los fármacos , Insecticidas/farmacología , Microscopía Electrónica de Rastreo , Estructura Molecular , Spodoptera , Streptomyces/clasificación , Streptomyces/ultraestructuraRESUMEN
The new glycothiohexide antibiotics, which are related to nosiheptide, were identified in fermentations of an actinomycete belonging to the genus "Sebekia". Strain LL-14E605 was classified as a "Sebekia" based on the presence of both mesodiaminopimelic acid and madurose in the cell wall and the presence of pseudosporangia encasing the spores. Culture LL-14E605 was successfully fermented in 10 to 3,000 liters of a complex medium. Antibiotic activity closely followed cell mass accumulation and usually peaked after 4 to 5 days of incubation. Glycothiohexide alpha demonstrated excellent in vitro activity against Gram-positive bacteria with MICs of 0.03 to 0.06 microgram/ml against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. However, glycothiohexide alpha failed to protect mice against a lethal challenge with Staphylococcus aureus Smith unless it was administered prior to challenge.