Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
Front Vet Sci ; 11: 1393039, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756505

RESUMO

Reports of renal neoplasia are rare in neotropical wildcats. Ocelots (Leopardus pardalis) are medium-sized wildcats living in America's tropical forests. A 12-year-old captive ocelot was diagnosed with a renal mass occupying approximately 25% of the total right kidney volume. The tissue was stained with routine hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS). Immunohistochemistry with the following markers was performed: cytokeratin (CK) AE1/AE3, CK19, CK 7, CD10, vimentin, Melan A, HMB45, Pax-8, and Wilms' tumor 1 (WT1). Histopathology revealed a well-differentiated epithelial tubular neoplasia with less than one mitotic figure per 2.37mm2 field. Vimentin and Pax-8 were the only positive markers. Immunohistochemically, neoplasia was diagnosed as a renal adenoma. Renal adenomas are seldom reported in neotropical wildcats. Reports on wild species are valuable for properly establishing a clinical prognosis for captive species. To the best of our knowledge, this is the first report that provides detailed microscopic and immunohistochemical descriptions of renal adenoma in a captive ocelot.

2.
Adv Biol (Weinh) ; 8(6): e2400069, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38548661

RESUMO

Engagement in physical activity, across various sports, promotes a diverse microbiota in active individuals. This study examines the gut microbiota of Colombian athletes, specifically weightlifters (n = 16) and road cyclists (n = 13), compared to non-athletes (n = 15). Using Kruskal-Wallis tests, the physical activity level of a group of non-athletic individuals and the sports experience of a group of professional athletes is analyzed. The median age of participants is 24 years, comprising 25 men and 19 women. The microbiota is collected using fecal samples. Participants provided these samples during their pre-competitive stage, specifically during the concentration phase occurring two weeks prior to national competitions. This timing is chosen to capture the microbial composition during a period of heightened physical preparation. Questionnaire responses and microbial composition assessments identify disparities among groups. Microbial composition analysis explores core microbiome, abundance, and taxonomy using Pavian, MicrobiomeAnalyst 2.0, and GraPhlAn. ANCOM-BC2 reveals differentially abundant species. Road cyclists exhibit decreased Bacteria and increased Archaea abundance. Phylum-level variations included Planctomycetes, Acidobacteria, and Proteobacteria, while Bacteroidetes prevailed. Key families influencing gut microbiota are Bacteroidaceae, Muribaculaceae, and Selenomonadaceae. Weightlifters exhibit unique viral and archaeal community connections, while cyclists showed specialized microbial interplay influenced by endurance exercise. Correlation network analysis emphasizes distinctive microbial interactions within athlete groups, shedding light on the impact of physical activities on gut microbiota and athlete health.


Assuntos
Archaea , Atletas , Bactérias , Ciclismo , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/fisiologia , Masculino , Feminino , Colômbia , Adulto , Atletas/estatística & dados numéricos , Archaea/isolamento & purificação , Adulto Jovem , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/genética , Levantamento de Peso/fisiologia , Fezes/microbiologia
3.
Rev Sci Instrum ; 94(5)2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37140340

RESUMO

Image reconstruction in optoacoustic tomography (OAT) is a trending learning task highly dependent on measured physical magnitudes present at sensing time. A large number of different settings and also the presence of uncertainties or partial knowledge of parameters can lead to reconstruction algorithms that are specifically tailored and designed to a particular configuration, which could not be the one that will ultimately be faced in a final practical situation. Being able to learn reconstruction algorithms that are robust to different environments (e.g., the different OAT image reconstruction settings) or invariant to such environments is highly valuable because it allows us to focus on what truly matters for the application at hand and discard what are considered spurious features. In this work, we explore the use of deep learning algorithms based on learning invariant and robust representations for the OAT inverse problem. In particular, we consider the application of the ANDMask scheme due to its easy adaptation to the OAT problem. Numerical experiments are conducted showing that when out-of-distribution generalization (against variations in parameters such as the location of the sensors) is imposed, there is no degradation of the performance and, in some cases, it is even possible to achieve improvements with respect to standard deep learning approaches where invariance robustness is not explicitly considered.

4.
Arch Soc Esp Oftalmol (Engl Ed) ; 97(8): 473-476, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35914891

RESUMO

PURPOSE: To show the results of a trocar spacer for pediatric vitreoretinal surgery with a 3D printed trocar spacer in 2 cases. METHODS: We used standard 27 gauge (ga) and 25 ga trocars and cannulae, and prototyped 1.5 mm × 3 mm spacers with a Prusa MK3 3D printer (0.4 mm nozzle) with Fuse deposition melting (FDM) technology. Parts were printed with a 50 µm layer height in polylactic acid or polylactide (PLA). The spacer was placed in two places: between the blade's base and the trocar, and between the trocar and the sclera depending on the desired amount of shortening. This prototype was used in 2 vitrectomy cases in pediatric patients. RESULTS: We used this trocar spacer in 2 cases with positive results. CONCLUSIONS: This 3D printed spacer has proved to effectively shorten the introduced trocar into two different small eyes. More studies are needed to validate the efficacy and safety of this spacer in clinical practice.


Assuntos
Cirurgia Vitreorretiniana , Criança , Humanos , Impressão Tridimensional , Esclera , Instrumentos Cirúrgicos , Vitrectomia
10.
Rev Sci Instrum ; 92(11): 114901, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852518

RESUMO

For photoacoustic image reconstruction, certain parameters such as sensor positions and speed of sound have a major impact on the reconstruction process and must be carefully determined before data acquisition. Uncertainties in these parameters can lead to errors produced by a modeling mismatch, hindering the reconstruction process and severely affecting the resulting image quality. Therefore, in this work, we study how modeling errors arising from uncertainty in sensor locations affect the images obtained by matrix model-based reconstruction algorithms based on time domain and frequency domain models of the photoacoustic problem. The effects on the reconstruction performance with respect to the uncertainty in the knowledge of the sensors location are compared and analyzed both in a qualitative and quantitative fashion for both time and frequency models. Ultimately, our study shows that the frequency domain approach is more sensitive to this kind of modeling errors. These conclusions are supported by numerical experiments and a theoretical sensitivity analysis of the mathematical operator for the direct problem.


Assuntos
Processamento de Imagem Assistida por Computador , Técnicas Fotoacústicas , Algoritmos , Imagens de Fantasmas , Som , Tomografia , Tomografia Computadorizada por Raios X
11.
Med. infant ; 27(2): 92-100, Diciembre 2020. Tab, ilus
Artigo em Espanhol | LILACS, UNISALUD, BINACIS | ID: biblio-1147907

RESUMO

Introducción: La incidencia de ACV (Accidente Cerebrovascular) en niños es de 2-13/100.000 niños por año, siendo una de las 10 causas más frecuentes de muerte en la infancia. La misma varía entre 6-40% dependiendo de las series publicadas y de los subtipos de ACV. Existen diferencias importantes entre el ACV en niños y adultos, ya que las características neurológicas y de la hemostasia son muy distintas en cada grupo. En niños deben ser investigados múltiples factores de riesgo que a menudo se superponen entre sí. Materiales y métodos: Trabajo descriptivo retrospectivo por revisión de historias clínicas, de una población de niños con diagnóstico de ACV ingresados en UCIP en un período de 10 años. Resultados: Se confirmó el diagnóstico de ACV en un total de 84 pacientes. El 70,24% de la población correspondía a ACVH (Accidente Cerebrovascular Hemorrágico) y un 29,76% ACVI (Accidente Cerebrovascular Isquémico). El 60,71 % eran masculinos. La mediana del tiempo entre el inicio de los síntomas y el ingreso a UCIP, en ambos grupos fue de 1 día con rango entre 1-17 días para los ACVH y 1-9 para los ACVI. Se evaluaron variables clínicas, de diagnóstico y de tratamiento según ambos tipos de ACV. Conclusión: El ACV requiere de un abordaje multidisciplinario. La realización de neuro-imágenes es un pilar fundamental para el diagnóstico y no debe ser pospuesto. El monitoreo y tratamiento está enfocado en minimizar el daño en el parénquima cerebral circundante (AU)


Introduction: The incidence of stroke in children is 2-13/100,000 children a year, being one of the 10 most common causes of death in childhood. Mortality varies between 6 and 40% depending on the series reported and according to the different subtypes of stroke. There are important differences between childhood and adult stroke, as the neurological features and characteristics of hemostasis vary greatly. In children, multiple risk factors that often overlap should be investigated. Material and methods: A retrospective descriptive review of the clinical records of a series of patients with stroke admitted to the pediatric intensive care unit (PICU) over a period of 10 years was conducted. Results: The diagnosis of stroke was confirmed in 84 patients; 70.24% had hemorrhagic and 29.76% ischemic stroke. Overall, 60.71% were boys. Median time between symptom onset and admission to the PICU was one day in both groups, ranging from 1-17 días for those with hemorrhagic and from 1-9 days for those with ischemic stroke. Clinical, diagnostic, and treatment variables were evaluated for both types of stroke. Conclusion: Stroke requires a multidisciplinary approach. Neuroimaging is essential for the diagnosis and should not be postponed. Monitoring and treatment is focused on minimizing damage to the surrounding brain parenchyma (AU)


Assuntos
Humanos , Lactente , Pré-Escolar , Criança , Adolescente , Unidades de Terapia Intensiva Pediátrica , Hemorragia Cerebral , Isquemia Encefálica , Acidente Vascular Cerebral/cirurgia , Acidente Vascular Cerebral/classificação , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/diagnóstico por imagem , Estudos Retrospectivos
13.
Waste Manag ; 87: 108-118, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31109509

RESUMO

Three kinds of waste resulting from woods from the Colombian industry were selected (PinusPátula, Tectona Grandis and Acacia Mangium) in order to assess their energy potential. Several techniques of physicochemical characterization were used to predict the most appropriate energy exploitation process in each case; which was validated at laboratory scale by carrying out the torrefaction, gasification and combustion process. Results allowed us to the identification of the high energy potential of such wood waste as well as their feasibility to generate torrefied products and synthesis gas as products with greater added values. As a special case, the species Tectona Grandis displayed the greatest conversion and synthesis gas quality on the basis of the gasification process, due to its physicochemical characteristics. These samples can be torrefacted in order to get a new product with higher energy potential than the original sample. Experimental study carried out, allowed us to demonstrate that there is a relationship between biomass chemical composition, yield, and process products. In addition, applying an additivity law of individual effects of the component, it is not possible to predict the process performances.


Assuntos
Resíduos Industriais , Madeira , Biomassa , Fenômenos Físicos
14.
Toxicol Appl Pharmacol ; 366: 96-103, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30703381

RESUMO

Diethyldithiophosphate (DEDTP) is a metabolite produced by the degradation of organophosphorus pesticides and a dialkylphosphate that is chemically synthesized with widespread commercial use. DEDTP is a stable compound, and most studies considered it harmless. However, some studies found adverse effects in vitro, including toxicity in different human cell types. However, there are no in vivo studies characterizing the toxicological effects of DEDTP. Therefore, we investigated the genotoxicity and immunotoxicity of DEDTP in a murine model. We used C57BL/6J and Balb/c mice (6-8-weeks-old) exposed to DEDTP i.p. We established that the medium lethal dose (LD50) of DEDTP was 0.537 g/kg. DEDTP was genotoxic in vivo because it increased the frequency of micronuclei in polychromatic erythrocytes in peripheral blood at 0.05 g/kg. DEDTP showed immunotoxic effects on T and Natural Killer cells and immunomodulatory effects on macrophages, especially M2 type that increased 1000% after 20 days of exposure to 0.01 g/kg. These effects modified the response to a tumoural challenge. DEDTP exposure increased tumour size and reduced the response of lymphocytes to tumoural antigen stimulation. We conclude that exposure to DEDTP produced genotoxic and immunomodulatory effects at environmentally relevant concentrations, which affected the growth of tumours in vivo. These results suggest that DEDTP might reduce the quality of life in exposed individuals, and it exhibits genotoxicity and immunotoxicity despite its stability.


Assuntos
Eritrócitos/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Fatores Imunológicos/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Organofosfatos/toxicidade , Organotiofosfatos/toxicidade , Praguicidas/toxicidade , Animais , Biomarcadores/sangue , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocinas/sangue , Eritrócitos/patologia , Feminino , Sistema Imunitário/metabolismo , Sistema Imunitário/patologia , Dose Letal Mediana , Masculino , Neoplasias Mamárias Experimentais/imunologia , Neoplasias Mamárias Experimentais/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Testes para Micronúcleos , Medição de Risco , Fatores de Tempo , Testes de Toxicidade Aguda , Carga Tumoral/efeitos dos fármacos
15.
Biochem Pharmacol ; 155: 141-149, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29935959

RESUMO

Several studies have identified the aryl hydrocarbon receptor (AhR) as a negative regulator of the innate and adaptive immune responses. However, the molecular mechanisms by which this transcription factor exerts such modulatory effects are not well understood. Interaction between AhR and RelA/p65 has previously been reported. RelA/p65 is the major NFκB subunit that plays a critical role in immune responses to infection. The aim of the present study was to determine whether the activation of AhR disrupted RelA/p65 signaling in mouse peritoneal macrophages by decreasing its half-life. The data demonstrate that the activation of AhR by TCDD and ß-naphthoflavone (ß-NF) decreased protein levels of the pro-inflammatory cytokines TNF-α, IL-6 and IL-12 after macrophage activation with LPS/IFNγ. In an AhR-dependent manner, TCDD treatment induces RelA/p65 ubiquitination and proteosomal degradation, an effect dependent on AhR transcriptional activity. Activation of AhR also induced lysosome-like membrane structure formation in mouse peritoneal macrophages and RelA/p65 lysosome-dependent degradation. In conclusion, these results demonstrate that AhR activation promotes RelA/p65 protein degradation through the ubiquitin proteasome system, as well as through the lysosomes, resulting in decreased pro-inflammatory cytokine levels in mouse peritoneal macrophages.


Assuntos
Mediadores da Inflamação/metabolismo , Lisossomos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Fator de Transcrição RelA/metabolismo , Ubiquitina/metabolismo , Animais , Células Cultivadas , Feminino , Interferon gama/toxicidade , Lipopolissacarídeos/toxicidade , Lisossomos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
16.
J Phys Condens Matter ; 30(27): 274005, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29799435

RESUMO

Surface pattern formation on amorphous SiO2 substrates by implantation of 1.0 MeV Si+ ions at a current of 1.3 µA at 70° angle is reported. Surface micrometer sized ripples perpendicular to the ion beam direction are formed, observed by scanning electron microscopy and atomic force microscopy. The morphological features are more or less similar for different fluences. The formation of surface ripples at this energy is discussed in terms of ion stopping mechanisms and patterns obtained within the low- and medium-energy ranges.

17.
Gen Comp Endocrinol ; 259: 154-160, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29174867

RESUMO

Taeniids tapeworms are hermaphroditic helminths that gradually develop testis and ovaries in their reproductive units. The larval stage of the tapeworms named cysticercus is a vesicle that contains the scolex and proliferates asexually in the abdominal cavity of mice. Once in the host, they evaginate, attach to the gut and develop into an adult organism, the tapeworm. We have previously reported reported that T. crassiceps ORF and solium cysticerci transform steroid precursors to androgens and estrogens. Taenia crassiceps WFU cysticerci can also synthesize corticosteroids. The aim of the present work is to investigate the relationship between steroid synthesis ability and the developmental stage of the parasite T. crassiceps WFU. To this purpose, cysticerci were obtained from the abdominal cavity of female mice, manually separated in invaginated (IC) and evaginated parasites (EC) and preincubated for 24 h in DMEM plus antibiotics/antimycotics. Next step consisted in incubation for different periods in the fresh media added with tritiated androstenedione (3H-A4) or progesterone (3H-P4) and incubated for different periods. Taenia crassiceps WFU tapeworms were recovered from the intestine of golden hamsters that had been orally infected with cysticerci. The worms were pre-cultured in DMEM plus FBS and antibiotics, and then incubated without FBS for different time periods, in the presence of 3H-A4 or 3H-P4. At the end of the experiments the media from cysticerci and tapeworms were analyzed by thin layer chromatography. Results showed that testosterone synthesis was significantly higher in the evaginated cysticerci and increased with time in culture. The invaginated and evaginated cysticerci also synthesized small quantities of 17ß-estradiol (E2) and estrone. The evaginated cysticerci synthesized twice more 3H-deoxycorticosterone (3H-DOC) than the invaginated parasites, the production increased significantly with time in culture. Taenia crassiceps WFU tapeworms synthesized significant quantities of 3H-testosterone and small amounts of estrone after only 3 h of culture in the presence of 3H-A4. The tapeworms also transformed 3H-P4 to 3H-DOC and increased its synthesis after 24 h in culture. In summary, our data show the pathways that T. crassiceps WFU cysticerci use to synthesize sexual steroids in both larval developmental stages and reveals the steroidogenic capacity of the tapeworms.


Assuntos
Parasitos/crescimento & desenvolvimento , Esteroides/metabolismo , Androstenodiona/metabolismo , Animais , Cysticercus , Feminino , Camundongos , Taenia
18.
Toxicol Appl Pharmacol ; 335: 6-15, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28943391

RESUMO

Jacareubin is a xanthone isolated from the heartwood of Calophyllum brasiliense with antibacterial and gastroprotective properties and the intention for clinical use as an anti-cancer treatment (due to the similar chemical structure to other anti-neoplastic drugs) requires an investigation of whether this compound can generate adverse effects on non-transformed cells. Jacareubin (0.5-1000µM in DMSO) was more cytotoxic on phytohemagglutinin (PHA)-stimulated normal human peripheral blood mononuclear cells (PBMCs; IC50 at 72h by MTT: 85.9µM) than on G0 phase-PBMCs (IC50 315.6µM) using trypan blue exclusion and formazan metabolism assays. Jacareubin had lower toxicity on PBMCs than Taxol (1µM). Jacareubin presented cytostatic activity because it inhibited PHA-stimulated PBMCs proliferation (from 2.5µM; CFSE dilution and replication index). Jacareubin induced PBMCs arrest in G0/G1 phase of the cell cycle (from 5µM) as evaluated by DNA content. Moreover, Jacareubin generated genotoxicity by breaking DNA strands selectively in PHA-stimulated PBMCs (from 5µM) rather than on resting PBMCs using the single-cell gel electrophoresis assay and increasing the frequency of micronucleated (MN) PBMCs in vitro (from 5µM) and frequency of hypodiploid cells (from 10µM). When 100mg/kg Jacareubin was injected i.p. into mice (a fifth of the LD50; 0.548g/kg. Approximately to 300µM in vitro), we observe no increase in the MN level in bone marrow cells. Jacareubin can be consider for further anti-tumoural activity due to its preferential genotoxic, cytotoxic and cytostatic actions on proliferating cells rather than on resting cells and the lack of in vivo genotoxicity.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Calophyllum/química , Dano ao DNA , Eritrócitos/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Extratos Vegetais/farmacologia , Xantonas/farmacologia , Adulto , Aneuploidia , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/toxicidade , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Eritrócitos/patologia , Humanos , Concentração Inibidora 50 , Leucócitos Mononucleares/patologia , Masculino , Camundongos Endogâmicos BALB C , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Medição de Risco , Fatores de Tempo , Xantonas/isolamento & purificação , Xantonas/toxicidade , Adulto Jovem
19.
Phys Chem Chem Phys ; 19(10): 7215-7227, 2017 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-28233880

RESUMO

We present a combined experimental and theoretical study dedicated to analyzing the structural stability and chemical reactivity of single walled carbon nanotubes (SWCNTs) in the presence of air and nitrogen atmospheres in the temperature interval of 300-1000 K. The temperature dependence of the radial breathing mode (RBM) region of the Raman spectra is irreversible in the presence of air, but it is reversible up to 1000 K in a nitrogen atmosphere. Our density functional theory (DFT) calculations reveal that irreversibility is due to partial degradation of SWCNTs produced by dissociative chemical adsorption of molecular oxygen on intrinsic defects of the nanotube surface. Oxygen partially opens the nanotubes forming semi-tubes with a non-uniform diameter distribution observed by Raman scattering. In contrast, heating CNTs in a nitrogen atmosphere seems to lead to the formation of nitrogen-doped SWCNTs. Our DFT calculations indicate that in general the most common types of nitrogen doping (e.g., pyridinic, pyrrolic, and substitutional) modify the location of the RBM frequency, leading also to frequency shifts and intensity changes of the surrounding modes. However, by performing a systematic comparison between calculated and measured spectra we have been able to infer the possible adsorbed configurations adopted by N species on the nanotube surface. Interestingly, by allowing previously nitrogen-exposed SWCNTs to interact with air at different temperatures (up to 1000 K) we note that the RBM region remains nearly unperturbed, defining thus our nitrogen-pretreated SWCNTs as more appropriate carbon nanostructures for high temperature applications in realistic environments. We believe that we have implemented a post-growth heat-treatment process that improves the stability of carbon nanotubes preserving their diameter and inducing a defect-healing process of the carbon wall.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA