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1.
Dermatol Online J ; 29(4)2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37921813

RESUMEN

Chordoma is an uncommon, indolent malignant tumor arising from notochordal remnants. The incidence of distant metastasis varies between 30 and 40% in different series. Even though local involvement of the skin by direct invasion of chordoma is common, distant skin metastasis are rare, with less than 30 cases reported in the literature. The present clinical case illustrates the slow-growing natural history of a sacral chordoma, which evolved with lung metastasis, followed three years later by skin metastasis, thus giving us the opportunity to review the diagnostic approach, as well as the clinical and histopathological characteristics of this rare tumor.


Asunto(s)
Cordoma , Neoplasias Pulmonares , Neoplasias Cutáneas , Neoplasias de la Columna Vertebral , Humanos , Cordoma/patología , Cordoma/secundario , Sacro/patología , Neoplasias de la Columna Vertebral/patología , Neoplasias Cutáneas/patología , Neoplasias Pulmonares/patología
2.
Environ Res ; 195: 110308, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33068573

RESUMEN

The Estuarine-Lagoon Complex of Iguape-Cananéia (ELCIC), a Marine Protected Area (MPA) in Brazil, was the focus of this study that aimed to relate external levels of exposure to contaminants to toxic effects on Gobioides broussonnetii fish. Different anthropogenic contaminants such as metals, polycyclic aromatic hydrocarbons (PAHs) and pharmaceuticals and personal care products (PPCPs) were analyzed in the sediments; and biochemical, histopathological and genotoxicity biomarkers evaluated in fish; in two different seasons at three sites of the estuarine region. Higher contamination of the sediments was observed near the main urban center (Iguape city - IG). Metal concentrations were considered low to moderate, while PAHs concentrations were considered low. The concentrations of PPCPs increased due to the anthropogenic presence and were higher near IG and the Cananéia Island (CI). Contributions from historical mining, agriculture, nautical activities, oil, sewage and waste disposal, biomass and fossil fuels combustion were identified. Higher concentrations of metals and PPCPs were observed during the cold-dry season, suggesting influences of the lower hydrodynamics during the season of lower precipitation. Higher PAHs concentrations occurred in the hot-rainy season, indicating influences of greater human presence in summer. In fish, biological responses followed the same spatial and seasonal pattern. More pronounced changes in antioxidant, biotransformation, histopathological and genotoxic biomarkers were observed in IG and CI. The multivariate analysis and the integrated biomarkers response index (IBR) also evidenced worse environmental conditions in these sites. This result can indicate a negative influence of anthropogenic activities on the contamination of sediments and on the biological responses of fish. This study presented the first ecotoxicological data for the species and suggested that these chronic exposures can cause adverse effects on this fish population. The data contribute to the understanding of local environmental quality and can be applied in the future to the environmental and social management of marine protected areas.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Brasil , Ciudades , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
3.
Proc Natl Acad Sci U S A ; 114(8): 1789-1794, 2017 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-28179565

RESUMEN

Intercellular communication via chemical signaling proceeds with both spatial and temporal components, but analytical tools, such as microfabricated electrodes, have been limited to just a few probes per cell. In this work, we use a nonphotobleaching fluorescent nanosensor array based on single-walled carbon nanotubes (SWCNTs) rendered selective to dopamine to study its release from PC12 neuroprogenitor cells at a resolution exceeding 20,000 sensors per cell. This allows the spatial and temporal dynamics of dopamine release, following K+ stimulation, to be measured at exceedingly high resolution. We observe localized, unlabeled release sites of dopamine spanning 100 ms to seconds that correlate with protrusions but not predominately the positive curvature associated with the tips of cellular protrusions as intuitively expected. The results illustrate how directionality of chemical signaling is shaped by membrane morphology, and highlight the advantages of nanosensor arrays that can provide high spatial and temporal resolution of chemical signaling.


Asunto(s)
Técnicas Biosensibles/métodos , Comunicación Celular/fisiología , Dopamina/metabolismo , Células-Madre Neurales/fisiología , Transducción de Señal/fisiología , Imagen Individual de Molécula/métodos , Animales , Técnicas Biosensibles/instrumentación , Membrana Celular/fisiología , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Electrodos , Fluorescencia , Microscopía , Modelos Neurológicos , Nanotubos de Carbono , Células PC12 , Ratas , Imagen Individual de Molécula/instrumentación , Análisis Espectral
4.
J Infect Dis ; 219(1): 110-120, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30534974

RESUMEN

Background: In pregnancy, Plasmodium falciparum parasites express the surface antigen VAR2CSA, which mediates adherence of red blood cells to chondroitin sulfate A (CSA) in the placenta. VAR2CSA antibodies are generally acquired during infection in pregnancy and are associated with protection from placental malaria. We observed previously that men and children in Colombia also had antibodies to VAR2CSA, but the origin of these antibodies was unknown. Here, we tested whether infection with Plasmodium vivax is an alternative mechanism of acquisition of VAR2CSA antibodies. Methods: We analyzed sera from nonpregnant Colombians and Brazilians exposed to P. vivax and monoclonal antibodies raised against P. vivax Duffy binding protein (PvDBP). Cross-reactivity to VAR2CSA was characterized by enzyme-linked immunosorbent assay, immunofluorescence assay, and flow cytometry, and antibodies were tested for inhibition of parasite binding to CSA. Results: Over 50% of individuals had antibodies that recognized VAR2CSA. Affinity-purified PvDBP human antibodies and a PvDBP monoclonal antibody recognized VAR2CSA, showing that PvDBP can give rise to cross-reactive antibodies. Importantly, the monoclonal antibody inhibited parasite binding to CSA, which is the primary in vitro correlate of protection from placental malaria. Conclusions: These data suggest that PvDBP induces antibodies that functionally recognize VAR2CSA, revealing a novel mechanism of cross-species immune recognition to falciparum malaria.


Asunto(s)
Antígenos de Protozoos/inmunología , Antígenos de Superficie/inmunología , Reacciones Cruzadas/inmunología , Malaria Falciparum/inmunología , Malaria Vivax/inmunología , Plasmodium falciparum/inmunología , Plasmodium vivax/inmunología , Proteínas Protozoarias/inmunología , Receptores de Superficie Celular/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Antiprotozoarios/sangre , Niño , Sulfatos de Condroitina , Colombia , Eritrocitos/parasitología , Euterios/inmunología , Femenino , Humanos , Inmunidad , Embarazo
5.
Cytogenet Genome Res ; 158(4): 213-224, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31352441

RESUMEN

Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chromosomes, and the species of each subgenus share the same characteristics in relation to heterochromatin regions, DAPI/CMA3 fluorophores, and the number and distribution of 18S rDNA sites. Microsatellites were observed only in euchromatin regions, whereas the (TTAGG)6 repeats were found at telomeric sites in both groups. Our data indicate that in addition to the chromosome number, the karyotypes in Melipona could be separated into 2 groups that are characterized by conserved cytogenetic features and patterns that generally are shared by species within each subgenus, which may reflect evolutionary constraints. Our results agree with the morphological separation of the Melipona into 4 subgenera, suggesting that they must be independent evolutionary lineages.


Asunto(s)
Abejas/clasificación , Abejas/genética , Mapeo Cromosómico , Análisis Citogenético , Secuencias Repetitivas de Ácidos Nucleicos/genética , Animales , Cromatina , Cromosomas de Insectos/genética , Diploidia , Heterocromatina , Cariotipificación , Filogenia
6.
Clin Oral Investig ; 23(7): 2941-2949, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30613870

RESUMEN

OBJECTIVE: This study aimed to prospectively observe gustatory and neurosensory alterations following surgical removal of mandibular third molars. MATERIAL AND METHODS: A prospective clinical study was conducted with patients who required mandibular third molar extraction, recruited from the Division of Oral and Maxillofacial Surgery at the Federal University of Ceará (Brazil). Age, sex, and radiographic signs were recorded. The outcome variables were the presence or absence of gustatory and neurosensory alterations. The patients were observed preoperatively and at 7, 30, 90, and 180 days postoperatively by using gustatory and neurosensory tests. RESULTS: The response to sweet (p = 0.509) and sour (p = 0.078) stimulus did not alter significantly over time. The salty threshold significantly increased from the preoperative to 7- and 30-day postoperative periods, returning to baseline values at 90 days postoperatively (p = 0.038). The bitter threshold increased significantly from the preoperative to 7-day postoperative period, returning to baseline values at 30 days after surgery (p < 0.001). Regarding neurosensory evaluation, there was an altered response to stimulus at 7 days postoperatively in specific studied areas, returning to baseline values 30 days after surgery (p < 0.05). CONCLUSION: The present study shows that mandibular third molar removal was associated with slight sensory disturbances related to mechanical, tactile, and gustatory perception. Regarding the recovery period, all patients returned to normal function without intervention, over a period ranging from 30 to 90 days. CLINICAL RELEVANCE: This study highlighted the importance of a sensory evaluation following removal of third molars, notably regarding mechanical perception and gustatory threshold assessment.


Asunto(s)
Tercer Molar , Trastornos del Gusto/etiología , Extracción Dental , Diente Impactado , Traumatismos del Nervio Trigémino , Femenino , Humanos , Masculino , Mandíbula , Diente Molar , Tercer Molar/cirugía , Estudios Prospectivos , Sensación , Diente Impactado/cirugía
7.
Microb Pathog ; 124: 152-162, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30142463

RESUMEN

The Alpinia purpurata inflorescence contains a lectin (ApuL), which has immunomodulatory activities on human cells. In the present work, it was evaluated the antibacterial and antifungal effects of ApuL against human pathogens. ApuL showed bacteriostatic activity against non-resistant (UFPEDA-02) and an oxacillin-resistant isolate (UFPEDA-672) of Staphylococcus aureus with minimal inhibitory concentrations (MIC50) of 50 and 400 µg/mL, respectively. In addition, it showed bactericidal effect on the non-resistant isolate (minimal bactericidal concentration: 200 µg/mL). For Candida albicans and Candida parapsilosis, ApuL showed fungistatic effect (MIC50: 200 and 400 µg/mL, respectively). The lectin was able to impair the viability of the microorganism cells, as indicated by propidium iodide (PI) staining. Analysis of growth curves, protein leakage, and ultrastructural changes supported that ApuL acts through distinct mechanisms on S. aureus isolates. Ultrastructural analysis of ApuL-treated Candida cells revealed malformations with elongations and bulges. ApuL-oxacillin combination showed synergistic effect on the oxacillin-resistant isolates UFPEDA-670 and 671, which were not sensitive to lectin alone. Synergism was also detected for ApuL-ceftazidime against a multidrug-resistant isolate of Pseudomonas aeruginosa. Synergistic action of ApuL-fluconazole was detected for C. parapsilosis, which was insensitive to the drug alone. Biofilm formation by S. aureus non-resistant isolate and C. albicans was remarkably inhibited by ApuL at sub-inhibitory concentrations. In conclusion, ApuL showed differential effects on non-resistant and resistant bacterial isolates, was active against Candida species, and showed synergistic action in combination with antibiotics.


Asunto(s)
Alpinia/química , Antibacterianos/farmacología , Antifúngicos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Lectinas/farmacología , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/aislamiento & purificación , Antifúngicos/aislamiento & purificación , Candida albicans/crecimiento & desarrollo , Candida albicans/fisiología , Sinergismo Farmacológico , Lectinas/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/fisiología
8.
J Bioenerg Biomembr ; 49(6): 473-483, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29147831

RESUMEN

Chagas disease is caused by the Trypanosoma cruzi affecting millions of people, and widespread throughout Latin America. This disease exhibits a problematic chemotherapy. Benznidazole, which is the drug currently used as standard treatment, lamentably evokes several adverse reactions. Among other options, natural products have been tested to discover a novel therapeutic drug for this disease. A lot of plants from the Brazilian flora did not contain studies about their biological effects. Restinga de Jurubatiba from Brazil is a sandbank ecosystem poorly studied in relation to plant biological activity. Thus, three plant species from Restinga de Jurubatiba were tested against in vitro antiprotozoal activity. Among six extracts obtained from leaves and stem parts and 2 essential oils derived from leave parts, only 3 extracts inhibited epimastigote proliferation. Substances present in the extracts with activity were isolated (quercetin, myricetin, and ursolic acid), and evaluated in relation to antiprotozoal activity against epimastigote Y and Dm28 Trypanosoma cruzi strains. All isolated substances were effective to reduce protozoal proliferation. Essentially, quercetin and myricetin did not cause mammalian cell toxicity. In summary, myricetin and quercetin molecule can be used as a scaffold to develop new effective drugs against Chagas's disease.


Asunto(s)
Antiprotozoarios/aislamiento & purificación , Ecosistema , Extractos Vegetales/toxicidad , Trypanosoma cruzi/efectos de los fármacos , Animales , Antiprotozoarios/química , Antiprotozoarios/toxicidad , Brasil , Línea Celular , Enfermedad de Chagas/prevención & control , Flavonoides/toxicidad , Humanos , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Quercetina/toxicidad
9.
Eur Neurol ; 77(1-2): 75-79, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27931037

RESUMEN

BACKGROUND/AIMS: Previous studies demonstrated an alteration of diaphragmatic excursion on the paretic side after stroke; however, it is unclear if this change has clinical repercussions. We aimed to determine if there was an association between the paretic side and the laterality of pneumonia after stroke. METHODS: A retrospective analysis of a consecutive cohort of patients admitted to a stroke unit from 2008 to May 2016 was performed. Patients with the diagnosis of acute stroke and pneumonia were included. The laterality of pneumonia was determined through the blinded observation of chest X-rays. Fisher's exact test was applied to study the association between the side of paresis and pneumonia. RESULTS: One hundred and five patients were included. Sixty one percent (n = 64) had an ischemic stroke, 39% (n = 41) had brain hemorrhage, and 49.5% (n = 52) had right side paresis. We did not find in general an association between the side of paresis and the side of pneumonia (p = 1.00); however, we found a statistically significant association in patients with severe lower limb paresis (Medical Research Council, MRC ≤2; p = 0.035). CONCLUSION: We found an association between severe paresis of the lower limb (MRC ≤2) and ipsilateral pneumonia. We hypothesize that the proximity between the diaphragmatic and inferior limb corticospinal pathways could be the reason for this association.


Asunto(s)
Neumonía/etiología , Neumonía/patología , Accidente Cerebrovascular/complicaciones , Adulto , Anciano , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Paresia/complicaciones , Estudios Retrospectivos
10.
J Neurosci Res ; 93(2): 268-84, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25306914

RESUMEN

Quinolinic acid (QUIN) is an endogenous metabolite of the kynurenine pathway involved in several neurological disorders. Among the several mechanisms involved in QUIN-mediated toxicity, disruption of the cytoskeleton has been demonstrated in striatally injected rats and in striatal slices. The present work searched for the actions of QUIN in primary striatal neurons. Neurons exposed to 10 µM QUIN presented hyperphosphorylated neurofilament (NF) subunits (NFL, NFM, and NFH). Hyperphosphorylation was abrogated in the presence of protein kinase A and protein kinase C inhibitors H89 (20 µM) and staurosporine (10 nM), respectively, as well as by specific antagonists to N-methyl-D-aspartate (50 µM DL-AP5) and metabotropic glutamate receptor 1 (100 µM MPEP). Also, intra- and extracellular Ca(2+) chelators (10 µM BAPTA-AM and 1 mM EGTA, respectively) and Ca(2+) influx through L-type voltage-dependent Ca(2+) channel (10 µM verapamil) are implicated in QUIN-mediated effects. Cells immunostained for the neuronal markers ßIII-tubulin and microtubule-associated protein 2 showed altered neurite/neuron ratios and neurite outgrowth. NF hyperphosphorylation and morphological alterations were totally prevented by conditioned medium from QUIN-treated astrocytes. Cocultured astrocytes and neurons interacted with one another reciprocally, protecting them against QUIN injury. Cocultured cells preserved their cytoskeletal organization and cell morphology together with unaltered activity of the phosphorylating system associated with the cytoskeleton. This article describes cytoskeletal disruption as one of the most relevant actions of QUIN toxicity in striatal neurons in culture with soluble factors secreted by astrocytes, with neuron-astrocyte interaction playing a role in neuroprotection.


Asunto(s)
Astrocitos/fisiología , Comunicación Celular/fisiología , Cuerpo Estriado/citología , Citoesqueleto/metabolismo , Homeostasis/efectos de los fármacos , Neuronas/efectos de los fármacos , Ácido Quinolínico/farmacología , Animales , Animales Recién Nacidos , Astrocitos/química , Comunicación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quelantes/farmacología , Técnicas de Cocultivo , Medios de Cultivo Condicionados/farmacología , Relación Dosis-Respuesta a Droga , Ácido Egtácico/análogos & derivados , Ácido Egtácico/farmacología , Inhibidores Enzimáticos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Femenino , Fosforilación/efectos de los fármacos , Embarazo , Ratas , Ratas Wistar , Valina/análogos & derivados , Valina/farmacología
11.
Exp Cell Res ; 322(2): 313-23, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24583400

RESUMEN

Quinolinic acid (QUIN) is a glutamate agonist which markedly enhances the vulnerability of neural cells to excitotoxicity. QUIN is produced from the amino acid tryptophan through the kynurenine pathway (KP). Dysregulation of this pathway is associated with neurodegenerative conditions. In this study we treated striatal astrocytes in culture with QUIN and assayed the endogenous phosphorylating system associated with glial fibrillary acidic protein (GFAP) and vimentin as well as cytoskeletal remodeling. After 24h incubation with 100 µM QUIN, cells were exposed to (32)P-orthophosphate and/or protein kinase A (PKA), protein kinase dependent of Ca(2+)/calmodulin II (PKCaMII) or protein kinase C (PKC) inhibitors, H89 (20 µM), KN93 (10 µM) and staurosporin (10nM), respectively. Results showed that hyperphosphorylation was abrogated by PKA and PKC inhibitors but not by the PKCaMII inhibitor. The specific antagonists to ionotropic NMDA and non-NMDA (50 µM DL-AP5 and CNQX, respectively) glutamate receptors as well as to metabotropic glutamate receptor (mGLUR; 50 µM MCPG), mGLUR1 (100 µM MPEP) and mGLUR5 (10 µM 4C3HPG) prevented the hyperphosphorylation provoked by QUIN. Also, intra and extracellular Ca(2+) quelators (1mM EGTA; 10 µM BAPTA-AM, respectively) prevented QUIN-mediated effect, while Ca(2+) influx through voltage-dependent Ca(2+) channel type L (L-VDCC) (blocker: 10 µM verapamil) is not implicated in this effect. Morphological analysis showed dramatically altered actin cytoskeleton with concomitant change of morphology to fusiform and/or flattened cells with retracted cytoplasm and disruption of the GFAP meshwork, supporting misregulation of actin cytoskeleton. Both hyperphosphorylation and cytoskeletal remodeling were reversed 24h after QUIN removal. Astrocytes are highly plastic cells and the vulnerability of astrocyte cytoskeleton may have important implications for understanding the neurotoxicity of QUIN in neurodegenerative disorders.


Asunto(s)
Citoesqueleto de Actina/efectos de los fármacos , Astrocitos/citología , Cuerpo Estriado/citología , Ácido Quinolínico/farmacología , Citoesqueleto de Actina/metabolismo , Animales , Apoptosis/efectos de los fármacos , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Western Blotting , Calcio/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Glutamatos/metabolismo , Técnicas para Inmunoenzimas , Fosforilación/efectos de los fármacos , Embarazo , Ratas , Ratas Wistar , Vimentina/metabolismo
12.
Acta Cardiol ; 70(6): 647-52, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26717212

RESUMEN

AIMS: Myocardial perfusion scintigraphy (MPS) is an important diagnostic tool in the management of patients with suspected coronary artery disease (CAD). However, the presence of mild-moderate perfusion defects can be challenging and may lead to unnecessary cardiac catheterization. Coronary computed tomography angiography (CCTA) is a method with excellent accuracy in the evaluation of CAD, but its role in this setting of patients has not been fully defined. This study aims to assess the potential of CCTA in the prediction of cardiac adverse events in patients with suspected CAD with non-significant perfusion defects by MPS. METHODS AND RESULTS: We conducted a cohort study in 292 patients presenting with non-significant perfusion defects by MPS undergoing a CCTA. The patients were followed for a mean of 34 months for occurrence of major cardiac adverse events - MACE. The majority of the patients (64.7%) were male, with a mean age of 57.9 ± 12.6 years. During the follow-up there were 37 MACE. In multivariate Cox proportional hazards model, hypertension and CCTA were independent predictors of MACE. The patients who presented a significant coronary obstruction by CCTA had a high risk of MACE (HR 15.3; 95% CI 4.06 to 57.90; P < 0.001). Kaplan-Meier curve showed a significant difference (log-rank χ²; P < 0.001) using CCTA in predicting MACE. CONCLUSION: CCTA carries a powerful prognostic value in predicting adverse events in patients with suspected CAD and MPS with mild-moderate perfusion defects and may be useful in risk stratification of these patients.


Asunto(s)
Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Circulación Coronaria/fisiología , Tomografía Computarizada de Emisión de Fotón Único/métodos , Tomografía Computarizada por Rayos X/métodos , Enfermedad de la Arteria Coronaria/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos
13.
J Am Chem Soc ; 136(2): 713-24, 2014 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-24354436

RESUMEN

Temporal and spatial changes in neurotransmitter concentrations are central to information processing in neural networks. Therefore, biosensors for neurotransmitters are essential tools for neuroscience. In this work, we applied a new technique, corona phase molecular recognition (CoPhMoRe), to identify adsorbed polymer phases on fluorescent single-walled carbon nanotubes (SWCNTs) that allow for the selective detection of specific neurotransmitters, including dopamine. We functionalized and suspended SWCNTs with a library of different polymers (n = 30) containing phospholipids, nucleic acids, and amphiphilic polymers to study how neurotransmitters modulate the resulting band gap, near-infrared (nIR) fluorescence of the SWCNT. We identified several corona phases that enable the selective detection of neurotransmitters. Catecholamines such as dopamine increased the fluorescence of specific single-stranded DNA- and RNA-wrapped SWCNTs by 58-80% upon addition of 100 µM dopamine depending on the SWCNT chirality (n,m). In solution, the limit of detection was 11 nM [K(d) = 433 nM for (GT)15 DNA-wrapped SWCNTs]. Mechanistic studies revealed that this turn-on response is due to an increase in fluorescence quantum yield and not covalent modification of the SWCNT or scavenging of reactive oxygen species. When immobilized on a surface, the fluorescence intensity of a single DNA- or RNA-wrapped SWCNT is enhanced by a factor of up to 5.39 ± 1.44, whereby fluorescence signals are reversible. Our findings indicate that certain DNA/RNA coronae act as conformational switches on SWCNTs, which reversibly modulate the SWCNT fluorescence. These findings suggest that our polymer-SWCNT constructs can act as fluorescent neurotransmitter sensors in the tissue-compatible nIR optical window, which may find applications in neuroscience.


Asunto(s)
Colorantes Fluorescentes/química , Microscopía Fluorescente/métodos , Nanotubos de Carbono/química , Neurotransmisores/análisis , Adsorción , Estructura Molecular
14.
Exp Cell Res ; 319(3): 89-104, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23142028

RESUMEN

Hyperprolinemia is an inherited disorder of proline (Pro) metabolism and patients affected by this disease may present neurological manifestations. However, the mechanisms of neural excitotoxicity elicited by hyperprolinemia are far from being understood. Considering the pivotal role of cytoskeletal remodeling in several neurodegenerative pathologies and the potential links between cytoskeleton, reactive oxygen species production and cell death, the aim of the present work was to study the effects of Pro on astrocyte and neuron cytoskeletal remodeling and the possible oxidative stress involvement. Pro induced a shift of actin cytoskeleton in stress fibers together with increased RhoA immunocontent and ERK1/2 phosphorylation/activation in cortical astrocytes. Unlike astrocytes, results evidenced little susceptibility of neuron cytoskeleton remodeling, since Pro-treated neurons presented unaltered neuritogenesis. We observed increased hydrogen peroxide production characterizing oxidative stress together with decreased superoxide dismutase (SOD) and catalase (CAT) activities in cortical astrocytes after Pro treatment, while glutathione peroxidase (GSHPx) activity remained unaltered. However, coincubation with Pro and Trolox/melatonin prevented decreased SOD and CAT activities in Pro-treated astrocytes. Accordingly, these antioxidants were able to prevent the remodeling of the actin cytoskeleton, RhoA increased levels and ERK1/2 phosphorylation in response to high Pro exposure. Taken together, these findings indicated that the cytoskeleton of cortical astrocytes, but not of neurons in culture, is a target to Pro and such effects could be mediated, at least in part, by redox imbalance, RhoA and ERK1/2 signaling pathways. The vulnerability of astrocyte cytoskeleton may have important implications for understanding the effects of Pro in the neurotoxicity linked to inborn errors of Pro metabolism.


Asunto(s)
Astrocitos/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Prolina/farmacología , Errores Innatos del Metabolismo de los Aminoácidos/metabolismo , Errores Innatos del Metabolismo de los Aminoácidos/patología , Animales , Animales Recién Nacidos , Antioxidantes/metabolismo , Astrocitos/metabolismo , Astrocitos/fisiología , Astrocitos/ultraestructura , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Corteza Cerebral/metabolismo , Corteza Cerebral/ultraestructura , Citoesqueleto/metabolismo , Citoesqueleto/fisiología , Embrión de Mamíferos , Estrés Oxidativo/fisiología , Prolina/efectos adversos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo
15.
Tumori ; : 3008916241257099, 2024 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-38825833

RESUMEN

BACKGROUND: Induction chemotherapy has been described as an option in locally advanced oral cavity squamous cell carcinoma when the surgical morbidity is expected to be high. This work aimed to evaluate the outcome and safety of induction chemotherapy in this setting. METHODS: We performed a retrospective and observational study including patients with oral cavity squamous cell carcinoma, treated with induction chemotherapy between January 2010 and December 2018. Outcomes included induction chemotherapy toxicity, treatment response, disease-free survival and overall survival. RESULTS: A total of 108 oral cavity squamous cell carcinoma patients were included. Ninety-six (88.9%) had stage IV disease, while 12 (11.1%) had stage III. Eighty-four patients (80.8%) achieved at least a partial response to induction chemotherapy at clinical evaluation, and 75 (72.1%) at radiological evaluation. Seventy-eight patients have been proposed for subsequent definitive treatments, with no differences obtained in prognosis, when comparing surgical to non-surgical approaches. In patients treated with definitive treatments, improved five-year disease-free survival was obtained if at least a clinical (56.3%; p=0.001) or radiological (52.9%; p=0.001) partial response was achieved after induction chemotherapy. Similarly, superior five-year overall survival was verified for those achieving at least clinical (51.1%; p<0.0001) or radiological (52.6%; p=0.001) partial response. Also, accomplishing a pathologic complete response (n=22.6%) significantly improved disease-free survival (p=0.039) and overall survival (p=0.005). Grade 3 and 4 toxicities were observed in 52 patients (41.8%). CONCLUSION: Responses to induction chemotherapy predicted prognosis in our population, however important toxicities were observed. Further studies are necessary to identify induction chemotherapy response predictors and subgroups who may benefit from this approach.

16.
Artículo en Inglés | MEDLINE | ID: mdl-38198376

RESUMEN

This study aimed to determine the antibiotic profile of microorganisms isolated from urine samples of patients with community urine tract infections (UTI) admitted to the University Hospital of the Federal University of Sao Carlos to support an appropriate local empirical treatment. A retrospective cross-sectional study was conducted from October 2018 to October 2020. Data from 1,528 positive urine cultures for bacterial pathogens and antibiograms were tabulated. Bacterial species prevalence and their resistance profile were analyzed and compared by sex and age. For Gram-negative fermenting bacteria, resistance rates were compared between patients with previous hospitalization and the total of infections caused by this group. For comparisons, the Chi-square test was performed, using Fisher's exact test when necessary (BioEstat program, adopting p ≤ 0.05). A multivariate analysis was applied to assess the effect of the studied variables in predicting multidrug resistance. Infections were more prevalent in women and older adults. Gram-negative bacteria represented 90.44% of total cultures. In both sexes, E. coli prevalence was significantly higher in adults compared with older adults (p < 0.0001). For several antibiotics, resistance rates were higher in the older adults compared with other ages and in patients with Gram-negative fermenting infections and previous hospitalization compared with the total of infections by this group of bacteria. The closer to the hospitalization, the higher the number of antibiotics with superior resistance rates. Resistance rates for aminoglycosides, carbapenems, ceftazidime, nitrofurantoin, piperacillin+tazobactam, and fosfomycin were less than 20%, considered adequate for empirical treatment. Only hospitalization in the previous 90 days was statistically significant in predicting infections by multidrug-resistant bacteria.


Asunto(s)
Antibacterianos , Infecciones Urinarias , Masculino , Humanos , Femenino , Anciano , Antibacterianos/farmacología , Brasil/epidemiología , Estudios Transversales , Escherichia coli , Prevalencia , Estudios Retrospectivos , Farmacorresistencia Bacteriana , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/epidemiología , Hospitalización , Hospitales Universitarios
17.
Environ Sci Pollut Res Int ; 31(31): 43927-43940, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38913262

RESUMEN

The caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae) is a prevalent pest in soybean plantations, managed using both natural and synthetic chemical products. However, the emergence of resistance in some populations emphasizes the need to explore alternative insecticides. Flupyradifurone, a neurotoxic insecticide, has not been previously used for controlling A. gemmatalis. This study evaluated the potential of flupyradifurone in the management of A. gemmatalis. Initially, the toxicity and anti-feeding effects, as well as histopathological and cytotoxic impacts, of flupyradifurone on A. gemmatalis were evaluated. Subsequently, the indirect effects of flupyradifurone on the midgut and fat body of the predator Podisus nigrispinus (Hemiptera: Pentatomidae) were verified. The results indicate the susceptibility of caterpillars to flupyradifurone, with an LC50 of 5.10 g L-1. Furthermore, the insecticide adversely affects survival, induces an anti-feeding response, and inflicts damage on the midgut of the caterpillars. However, flupyradifurone also leads to side effects in the predator P. nigrispinus through indirect intoxication of the caterpillars, including midgut and fat body damage. While flupyradifurone demonstrates toxicity to A. gemmatalis, suggesting its potential for the chemical control of this pest, the indirect negative effects on the predator indicate the need for its controlled use in integrated pest management programs with the insecticide and the predator.


Asunto(s)
Insecticidas , Animales , Insecticidas/toxicidad , Larva/efectos de los fármacos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/toxicidad , Heterópteros/efectos de los fármacos , Mariposas Nocturnas/efectos de los fármacos , Lepidópteros/efectos de los fármacos , Piridinas
19.
J Arrhythm ; 40(1): 124-130, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38333395

RESUMEN

Background: Programmed ventricular stimulation (PVS) during electrophysiological study (EPS), is a globally accepted tool for risk stratification of sudden cardiac death (SCD) in some specific clinical situations. The aim of this study was to evaluate the prognosis of ventricular arrhythmia induction in a cohort of patients with syncope of undetermined origin (SUO). Methods: This is a historical cohort study in a population of patients with SUO referred for EPS between the years 2008-2021. In this interval, 575 patients underwent the procedure. Results: Patients with induced ventricular arrhythmias had a higher occurrence of structural heart disease (36.7% vs. 76.5%), ischemic heart disease (28.2 vs. 57.1%), heart failure (15.5% vs. 34.4%), and lower left ventricular ejection fraction (59.16% vs. 47.51%), when compared to the outcome with a negative study. PVS triggered ventricular arrhythmias in 98 patients, 62 monomorphic and 36 polymorphic. During a median follow-up of 37.6 months, 100 deaths occurred. Only the induction of sustained ventricular arrhythmias showed a significant association with the primary outcome (all-cause mortality) with a p value <.001. After the performance of EPS, 142 patients underwent cardioverter-defibrillator (ICD) implantation. At study follow-up, 30 patients had therapies by the device. Only the induction of sustained monomorphic ventricular arrhythmia showed statistically significant association with appropriate therapies by the device (p = .012). Conclusion: In patients with SUO, the induction of sustained monomorphic ventricular arrhythmia after programmed ventricular pacing is related to a worse prognosis, with a higher incidence of mortality and appropriate therapies by the ICD.

20.
Metab Brain Dis ; 28(3): 429-38, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23378107

RESUMEN

Carbonyl compounds such as methylglyoxal (MGO) seem to play an important role in complications resulting from diabetes mellitus, in aging and neurodegenerative disorders. In this study, we are showing, that MGO is able to suppress cell viability and induce apoptosis in the cerebral cortex and hippocampus of neonatal rats ex-vivo. These effects are partially related with ROS production, evaluated by DCFH-DA assay. Coincubation of MGO and reduced glutathione (GSH) or Trolox (vitamin E) totally prevented ROS production but only partially prevented the MGO-induced decreased cell viability in the two brain structures, as evaluated by the MTT assay. Otherwise, L-NAME, a nitric oxide (NO) inhibitor, partially prevented ROS production in the two structures but partially prevented cytotoxicity in the hippocampus. Pharmacological inhibition of Erk, has totally attenuated MGO-induced ROS production and cytotoxicity, suggesting that MEK/Erk pathway could be upstream of ROS generation and cell survival. Otherwise, p38MAPK and JNK failed to prevent ROS generation but induced decreased cell survival consistent with ROS-independent mechanisms. We can propose that Erk, p38MAPK and JNK are involved in the cytotoxicity induced by MGO through different signaling pathways. While Erk could be an upstream effector of ROS generation, p38MAPK and JNK seem to be associated with ROS-independent cytotoxicity in neonatal rat brain. The cytotoxic damage progressed to apoptotic cell death at MGO concentration higher than those described for adult brain, suggesting that the neonatal brain is resistant to MGO-induced cell death. The consequences of MGO-induced brain damage early in life, remains to be clarified. However, it is feasible that high MGO levels during cortical and hippocampal development could be, at least in part, responsible for the impairment of cognitive functions in adulthood.


Asunto(s)
Encéfalo/patología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Piruvaldehído/toxicidad , Animales , Animales Recién Nacidos , Anexina A5/metabolismo , Antioxidantes/farmacología , Western Blotting , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Supervivencia Celular/efectos de los fármacos , Colorantes , Colorantes Fluorescentes , Técnicas In Vitro , L-Lactato Deshidrogenasa/metabolismo , MAP Quinasa Quinasa 4/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Piruvaldehído/antagonistas & inhibidores , Piruvaldehído/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Sales de Tetrazolio , Tiazoles , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
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