Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
1.
Sci Prog ; 107(3): 368504241261844, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39051508

RESUMO

PURPOSE: Physical inactivity is considered an important risk factor for osteoporosis, however, some athletes performing extremely high training volumes can also develop bone mass loss. Moreover, the effect of total body mass or body surface area on bone mineral density remains controversial. Therefore, the aim of this study was to compare the absolute bone mineral density and bone mineral density adjusted to body surface area between amateur triathletes and nonactive women. METHODS: Forty-two healthy women (23 amateur triathletes and 19 nonactive individuals) were evaluated for body composition using a dual-energy X-ray absorptiometry system. RESULTS: Compared to nonactive women, amateur triathletes exhibited lower body mass index (p < 0.001), lower bone mineral density (p < 0.001), and body surface area (p < 0.001). However, bone mineral density adjusted by body surface area in the triathletes was higher than in the nonactive women (p = 0.03). CONCLUSION: These findings showed that amateur triathles presented lower absolute bone mineral density, but higher bone mineral density adjusted to body surface area. Future studies are recommended to identify if the higher bone mineral density adjusted to body surface area are associated with a lower bone fragility.


Assuntos
Absorciometria de Fóton , Atletas , Densidade Óssea , Humanos , Densidade Óssea/fisiologia , Feminino , Estudos Transversais , Adulto , Pessoa de Meia-Idade , Composição Corporal/fisiologia , Índice de Massa Corporal , Natação/fisiologia , Osteoporose/fisiopatologia , Osteoporose/diagnóstico por imagem
2.
Pharmaceutics ; 16(3)2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38543245

RESUMO

Floating controlled systems seek to extend the gastric retention time (GRT) of solid pharmaceutical forms by sustaining buoyancy in the stomach without affecting gastric emptying rates. This investigation aimed to evaluate a magnetic floating drug delivery system (MFDDS) under diverse physiological conditions (pressure and viscosity) using an Alternating Current Biosusceptometry (ACB) system by conducting assessments in vitro and in vivo. For in vitro experiments, MFDDSs were placed under different pressures (760, 910, and 1060 mmHg) and viscosities (1, 50, 120, and 320 mPa·s) for evaluation of floating lag time (FLT). For in vivo experiments, eight healthy volunteers participated in two phases (fasting and fed) for gastric parameters (GRT, FLT, and OCTT-orocaecal transit time) assessment, employing the ACB system. The results indicated that pressure, viscosity, and FLT were directly proportional in the in vitro assay; in addition, increases in the OCTT (fasting = 241.9 ± 18.7; fed = 300 ± 46.4), GRT (fasting = 139.4 ± 25.3; fed = 190.2 ± 47.7), and FLT (fasting = 73.1 ± 16.9; fed = 107.5 ± 29.8) were detected in vivo. Our study emphasizes that the ACB system is a valuable technique, and it is capable of tracking and imaging MFDDS in in vitro and in vivo experiments.

3.
Med. oral patol. oral cir. bucal (Internet) ; 29(2): e288-e296, Mar. 2024. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-231233

RESUMO

Background: Collagen is a component of Pyogenic Granuloma (PG) and Peripheral Ossifying Fibroma (POF) and performs different functions in these lesions. The objective of this study is to evaluate the role of collagen and immunostaining for Transforming Growth Factor beta (TGF-β) in the clinical and microscopic findings of PG and POF. Material and Methods: PG (n=20) and POF (n=20) were selected for clinical evaluation (sex, age, localization, size and evolution time) and microscopic analysis (picrosirius red staining for collagen analysis and immunohistochemistry for TGF-β) performed in the superficial and deep areas of the two lesions. ANOVA/Bonferroni and t-test, Pearson correlation and χ2 were used to compare the sites and parameters analyzed (p<0.05, GraphPad Prism 5.0). Results: The depth of PG presented the highest amount of collagen (p<0.001), and its surface showed the lowest amount of type 1 collagen (yellow-red strong birefringence). Type 1 collagen gradually increased in depth of PG, surface and depth of POF (p<0.001). The number of TGF-β+ cells was lower on the surface of PG compared with the depth of PG and the two areas of POF (p<0.001). Sex and localization did not affect these parameters, but the profile of collagen and immunostaining for TGF-β suffered from modifications by the time of evolution and the size of the lesion. Conclusions: Although PG and POF are reactive gingival lesions, the expression of TGF-β and its role in collagen showed different biological behaviors in these lesions, suggesting different biological origins for its components. (AU)


Assuntos
Humanos , Colágeno , Fibroma Ossificante , Sexo , Ferimentos e Lesões , Células
4.
Braz. J. Pharm. Sci. (Online) ; 60: e23717, 2024. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1557201

RESUMO

Constipation is a disorder of the gastrointestinal (GI) and some of the main etiological mechanisms are directly related to changes in GI physiology. The capacity to carry out paired assessments and measure GI parameters under the influence of constipation is a relevant point in selecting a suitable methodology. We aimed to perform a non-invasive investigation of gastrointestinal motility in constipated rats using the alternating current biosusceptometry system (ACB). The animals were split into two groups: the pre-induction stage (CONTROL) and post-induction loperamide stage (LOP). We assessed GI motility parameters using the ACB system. Colon morphometric and immunohistochemical analyses were performed for biomarkers (C-kit) for interstitial cells of Cajal (ICC). Our results showed a significant increase in gastrointestinal transit in the LOP group in addition to a reduction in the dominant frequency of gastric contraction and an arrhythmic profile. A change in colonic contractility profiles was observed, indicating colonic dysmotility in the LOP group. We found a reduction in the number of biomarkers for intestinal cells of Cajal (ICC) in the LOP group. The ACB system can evaluate transit irregularities and their degrees of severity, while also supporting research into novel, safer, and more efficient treatments for constipation.


Assuntos
Animais , Masculino , Ratos , Trato Gastrointestinal/anormalidades , Motilidade Gastrointestinal , Loperamida/efeitos adversos , Constipação Intestinal/induzido quimicamente , Células Intersticiais de Cajal/classificação
5.
J Trace Elem Med Biol ; 81: 127343, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38035449

RESUMO

BACKGROUND: Coal and coal ash present inorganic elements associated with negative impacts on environment and human health. The objective of this study was to compare the toxicity of coal and coal ash from a power plant, assess their inorganic components, and investigate the biological impacts and potential mechanisms through in vitro and in vivo testing. METHODS: Particle-Induced X-ray Emission method was used to quantify inorganic elements and the toxicity was evaluated in Caenorhabditis elegans and Daphnia magna in acute and chronic procedures. The genotoxic potential was assessed using alkaline and FPG-modified Comet assay in HepG2 cells and mutagenicity was evaluated using Salmonella/microsome assay in TA97a, TA100, and TA102 strains. RESULTS: Inorganic elements such as aluminum (Al) and chromium (Cr) were detected at higher concentrations in coal ash compared to coal. These elements were found to be associated with increased toxicity of coal ash in both Caenorhabditis elegans and Daphnia magna. Coal and coal ash did not induce gene mutations, but showed genotoxic effects in HepG2 cells, which were increased using the FPG enzyme, indicating DNA oxidative damage. CONCLUSIONS: The combined findings from bioassays using C. elegans and D. magna support the higher toxicity of coal ash, which can be attributed to its elevated levels of inorganic elements. The genotoxicity observed in HepG2 cells confirms these results. This study highlights the need for continuous monitoring in areas affected by environmental degradation caused by coal power plants. Additionally, the analysis reveals significantly higher concentrations of various inorganic elements in coal ash compared to coal, providing insight into the specific elemental composition contributing to its increased toxicity.


Assuntos
Caenorhabditis elegans , Cinza de Carvão , Animais , Humanos , Cinza de Carvão/toxicidade , Cinza de Carvão/análise , Carvão Mineral/toxicidade , Carvão Mineral/análise , Dano ao DNA , Ensaio Cometa
6.
J Pharm Pharmacol ; 75(12): 1560-1568, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-37831664

RESUMO

OBJECTIVES: This study aimed to evaluate the effects of prucalopride, a prokinetic agent that acts as a potent serotonin agonist of 5-HT4 receptors, on gastric emptying and small bowel transit and assess its impact on the absorption of metronidazole. METHODS: Six healthy volunteers, three men and three women, aged between 20 and 27 years, with a body weight ranging from 50 to 80 kg, were enrolled in this study. The pharmacokinetics and gastrointestinal transit parameters were evaluated simultaneously through pharmacomagnetography assessment, combining alternating current biosusceptometry and blood analysis. KEY FINDINGS: The results showed that prucalopride enhances gastric emptying and small bowel transit when administered orally and significantly impacts the rate of metronidazole absorption, leading to enhanced bioavailability and rapid therapeutic response. CONCLUSION: Pharmacomagnetography assessment allows simultaneous tracking of transit by images and is a valuable method for analysing drug absorption using multiple instruments.


Assuntos
Esvaziamento Gástrico , Metronidazol , Masculino , Humanos , Feminino , Adulto Jovem , Adulto , Metronidazol/farmacologia , Trânsito Gastrointestinal
7.
Sci Adv ; 9(35): eadg9204, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37656782

RESUMO

Despite the considerable morbidity and mortality of yellow fever virus (YFV) infections in Brazil, our understanding of disease outbreaks is hampered by limited viral genomic data. Here, through a combination of phylogenetic and epidemiological models, we reconstructed the recent transmission history of YFV within different epidemic seasons in Brazil. A suitability index based on the highly domesticated Aedes aegypti was able to capture the seasonality of reported human infections. Spatial modeling revealed spatial hotspots with both past reporting and low vaccination coverage, which coincided with many of the largest urban centers in the Southeast. Phylodynamic analysis unraveled the circulation of three distinct lineages and provided proof of the directionality of a known spatial corridor that connects the endemic North with the extra-Amazonian basin. This study illustrates that genomics linked with eco-epidemiology can provide new insights into the landscape of YFV transmission, augmenting traditional approaches to infectious disease surveillance and control.


Assuntos
Febre Amarela , Vírus da Febre Amarela , Humanos , Vírus da Febre Amarela/genética , Filogenia , Brasil/epidemiologia , Febre Amarela/epidemiologia , Surtos de Doenças , Genômica
8.
Arch Oral Biol ; 155: 105793, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37633029

RESUMO

OBJECTIVE: To evaluate the healing potential of Nile tilapia skin collagen using a rat model with experimentally induced traumatic oral ulcers. DESIGN: Male Wistar rats were segregated into three experimental groups (n = 8/group/euthanasia day). Ulcers were induced using a dermatological punch on the left buccal mucosa. The rats were then euthanized on days 1, 5, 10, 15, and 20 (ntotal=120 rats). Each group received topical treatment, 2x/day, with 1 % Nile tilapia skin collagen orabase (experimental group), only orabase (negative control), or Oncilom-A® orabase (positive control). Ulcer area, closure percentage, and body mass variation were measured. Slides were prepared for histological analysis, which included Picrosirius red staining (collagen analysis), and immunohistochemistry (platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta). RESULTS: On day 15, the experimental and positive control groups displayed smaller ulcer areas, a higher percentage of closure, complete re-epithelialization, superior histological repair scores, and a reduced count of polymorphonuclear cells in comparison to the negative control group (p < 0.05). Additionally, the experimental group exhibited an increased number of blood vessels, total collagen (types I and III) and expression of platelet endothelial cell adhesion molecule, alpha-smooth muscle actin, and transforming growth factor-beta relative to the negative and positive control groups (p < 0.05). By day 20, the experimental group showed a more significant weight gain compared to the other groups (p < 0.0001). CONCLUSIONS: Nile tilapia skin collagen orabase optimizes the healing of traumatic ulcers by stimulating re-epithelialization, angiogenesis, and collagenesis. Transforming growth factor-beta plays a significant role in this process.


Assuntos
Ciclídeos , Úlceras Orais , Ratos , Masculino , Animais , Cicatrização/fisiologia , Úlcera/metabolismo , Úlceras Orais/tratamento farmacológico , Ratos Wistar , Actinas/metabolismo , Pele , Colágeno/metabolismo , Fatores de Crescimento Transformadores/metabolismo , Moléculas de Adesão Celular/metabolismo
9.
Plants (Basel) ; 12(11)2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37299061

RESUMO

Future predictions due to climate change are of decreases in rainfall and longer drought periods. The search for new tolerant crops is an important strategy. The objective of this study was to evaluate the effect of water stress on the physiology and productivity of crops with potential for growing in the off-season period in the Cerrado, and evaluate correlations with the temperature of the canopy obtained by means of thermography. The experiment was conducted under field conditions, with experimental design in randomized blocks, in a split-plot scheme and four replications. The plots were: common bean (Phaseolus vulgaris); amaranth (Amaranthus cruentus); quinoa (Chenopodium quinoa); and buckwheat (Fagopyrum esculentum). The subplots were composed of four water regimes: maximum water regime (WR 535 mm), high-availability regime (WR 410 mm), off-season water regime (WR 304 mm) and severe water regime (WR 187 mm). Under WR 304 mm, the internal concentration of CO2 and photosynthesis were reduced by less than 10% in amaranth. Common bean and buckwheat reduced 85% in photosynthesis. The reduction in water availability increased the canopy temperature in the four crops and, in general, common bean was the most sensitive species, while quinoa had the lowest canopy temperatures. Furthermore, canopy temperature correlated negatively with grain yield, biomass yield and gas exchange across all plant species, thus thermal imaging of the canopy represents a promising tool for monitoring crop productivity for farmers, For the identification of crops with high water use management for research.

10.
J Vet Behav ; 60: 37-43, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36531836

RESUMO

The COVID-19 pandemic changed the routines of people, consequently changing the daily lives of their pets. Behavioral and emotional changes caused by the stress resulting from restrictions of social isolation and their consequences in the human-animal relationship have been discussed. However, there are still no studies that identify the factors that affect behavior and which are the most susceptible groups. The purpose of this study is to identify behavioral and emotional changes on dogs during the COVID-19 pandemic and their effects on the quality of life of animals and their owners. The methodology used was online questionnaires, which were posted on social networks aimed to dog owners in Rio de Janeiro state, Brazil. The results showed that age, sex, dog size, type of home, and restrictions imposed differently affected the type of behavioral change. However, the most frequent type of change was the worsening of previous conditions. Neutered behaviors directly interfered in the lives of owners and their pets, as owners managed the situation and sought information without guidance from a veterinarian, with the possibly consequence of worsening the situation in the future. Veterinarians should actively investigate behavioral changes that have occurred through anamnesis to avoid abandonment and instability in the human-animal relationship.

11.
Rev. bras. educ. méd ; 47(3): e091, 2023. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1449625

RESUMO

Abstract: Introduction: Typical medical care has been characterized by professional and disease-centered attitudes, with little concern for focusing on the patient's psychosocial context and expectations. However, the medical care that seeks to more globally encompass the patient's perspective has shown to bring greater benefits. Objective: To evaluate the attitudes of medical students regarding the physician-patient relationship. Methods: This is a cross-sectional study that evaluated the attitudes of students in the 4th semester of the medical course in relation to patient care based on the application of the Patient-Practitioner Orientation Scale and a questionnaire with sociodemographic and curricular characteristics. Data were analyzed using the Statistical Package for Social Science (SPSS) software and the Mann-Whitney test, Kruskal-Wallis test with Dunn's post hoc, and Chi-square test. Results: A total of 83 medical students participated in the study, with a prevalence of female students (74.7%), and those who declared a family income of less than US$ 2,140 (43.0%), as well as those who professed the Catholic religion (53.0%). The majority of students (85.5%) had attitudes centered on the physician and the disease (mean PPOS scores <4.57), with scores in the caring domain higher than those in the sharing domain. The variables gender, family income, student financial aid, and religion showed a positive association (p≤0.05) with PPOS scores related to patient-centered attitudes. There were no statistically significant associations of PPOS scores with the variables age group, city of origin, undergraduate research activities, extracurricular internships, artistic activities, personal and family history of serious illness, and parental level of schooling. Conclusion: The present study showed that the assessed medical students had attitudes centered on the physician and on the disease, with mean PPOS scores below the range related to attitudes of humanized medicine.


Resumo: Introdução: O atendimento médico usual tem sido caracterizado por atitudes centradas no profissional e na doença, pouco se preocupando em focar o contexto psicossocial e as expectativas do paciente. Entretanto, o atendimento médico que procura abranger mais globalmente a perspectiva do paciente tem se mostrado mais eficiente ao promover maiores benefícios. Objetivo: Este estudo teve como objetivo avaliar as atitudes de estudantes de Medicina a respeito da relação médico-paciente. Método: Trata-se de um estudo transversal que avaliou as atitudes de acadêmicos do quarto período de Medicina em relação à atenção aos pacientes a partir da aplicação da Escala de Orientação Médico-Paciente (EOMP) e de questionário com características sociodemográficas e curriculares. Os dados foram analisados no software Statistical Package for Social Science (SPSS), e utilizaram-se o teste de Mann-Whitney, o teste de Kruskall-Wallis com post hoc de Dunn e o teste de qui-quadrado. Resultado: Participaram do estudo 83 estudantes de Medicina, com prevalência maior de alunos do sexo feminino (74,7%) e que declararam renda familiar inferior a dez salários mínimos (43,0%), bem como a religião católica (53,0%). A maioria dos acadêmicos (85,5%) apresentou atitudes centradas no médico e na doença (média de escores da EOMP < 4,57), com escores do domínio cuidar superiores aos do domínio compartilhar. As variáveis sexo, renda familiar, bolsa de auxílio financeiro estudantil e religião apresentaram associação positiva (p ≤ 0,05) com os escores da EOMP relacionados às atitudes centradas no paciente. Não foram observadas associações estatisticamente significativas dos escores da EOMP entre as variáveis faixa etária, cidade de procedência, realização de atividades de iniciação científica, estágios extracurriculares, atividades artísticas, antecedentes pessoais e familiares de doença grave, e escolaridade dos pais. Conclusão: O presente estudo demonstrou que os acadêmicos de Medicina avaliados apresentaram atitudes centradas no médico e na doença, com média de escores da EOMP abaixo do intervalo relacionado às atitudes da medicina humanizada.

12.
Mar Pollut Bull ; 185(Pt B): 114339, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36395712

RESUMO

Many studies investigated the presence and effects of microplastics in marine species, but data about sponges are still incipient. We quantified these pollutants in a population of the tropical sponge Cinachyrella alloclada, comparing museum specimens sampled in 1981 with specimens sampled in 2017. The mean number of microplastics in specimens collected decades ago was one order of magnitude lower (0.13 ± 0.40/g of sponge tissue) than those sampled more recently (1.37 ± 0.94/g). We observed microplastics in only 10 % of the specimens collected in 1981 but in 80 % of those from 2017. According to Raman spectroscopy, fibers in C. alloclada consisted of polypropylene. Our results reinforce the importance of natural history collections to reduce the gap of knowledge on the interaction between marine sponges and microplastics.


Assuntos
Poluentes Ambientais , Poríferos , Animais , Microplásticos , Plásticos , Conhecimento
13.
J Biol Eng ; 16(1): 25, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36221096

RESUMO

BACKGROUND: Non-invasive magnetic imaging techniques are necessary to assist magnetic nanoparticles in biomedical applications, mainly detecting their distribution inside the body. In Alternating Current Biosusceptometry (ACB), the magnetic nanoparticle's magnetization response under an oscillating magnetic field, which is applied through an excitation coil, is detected with a balanced detection coil system. RESULTS: We built a Multi-Channel ACB system (MC-ACB) containing nineteen pick-up coils and obtained 2D quantitative images of magnetic nanoparticle distributions by solving an inverse problem. We reconstructed the magnetic nanoparticles spatial distributions in a field of view of 14 × 14 cm2 with a spatial resolution of 2.0 cm and sensitivity in the milligram scale. A correlation coefficient between quantitative reconstructed and nominal magnetic nanoparticle distributions above 0.6 was found for all measurements. CONCLUSION: Besides other interesting features such as sufficient large field of view dimension for mice and rat studies, portability, and the ability to assess the quantitative magnetic nanoparticles distributions in real-time, the MC-ACB system is a promising tool for quantitative imaging of magnetic nanoparticles distributions in real-time, offering an affordable setup for easy access in clinical or laboratory environments.

14.
Plants (Basel) ; 11(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36079581

RESUMO

Coffee farmers have faced problems due to drought periods, with irrigation being necessary. In this sense, this study aimed to evaluate the responses to different levels and durations of water deficit in arabica coffee genotypes in the Cerrado region. The experiment consisted of three Coffea arabica genotypes and five water regimes: full irrigation (FI 100 and FI 50-full irrigation with 100% and 50% replacement of evapotranspiration, respectively), water deficit (WD 100 and WD 50-water deficit from June to September, with 100% and 50% replacement of evapotranspiration, respectively) and rainfed (without irrigation). The variables evaluated were gas exchange, relative water content (RWC) and productivity. The results showed that during stress, plants under the FI water regime showed higher gas exchange and RWC, differently from what occurred in the WD and rainfed treatments; however, after irrigation, coffee plants under WDs regained their photosynthetic potential. Rainfed and WD 50 plants had more than 50% reduction in RWC compared to FIs. The Iapar 59 cultivar was the most productive genotype and the E237 the lowest. Most importantly, under rainfed conditions, the plants showed lower physiological and productive potential, indicating the importance of irrigation in Coffea arabica in the Brazilian Cerrado.

15.
Pharmaceutics ; 14(9)2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36145654

RESUMO

Since magnetic nanoparticles (MNPs) have been used as multifunctional probes to diagnose and treat liver diseases in recent years, this study aimed to assess how the condition of cirrhosis-associated hepatocarcinogenesis alters the biodistribution of hepatic MNPs. Using a real-time image acquisition approach, the distribution profile of MNPs after intravenous administration was monitored using an AC biosusceptometry (ACB) assay. We assessed the biodistribution profile based on the ACB images obtained through selected regions of interest (ROIs) in the heart and liver position according to the anatomical references previously selected. The signals obtained allowed for the quantification of pharmacokinetic parameters, indicating that the uptake of hepatic MNPs is compromised during liver cirrhosis, since scar tissue reduces blood flow through the liver and slows its processing function. Since liver monocytes/macrophages remained constant during the cirrhotic stage, the increased intrahepatic vascular resistance associated with impaired hepatic sinusoidal circulation was considered the potential reason for the change in the distribution of MNPs.

16.
Materials (Basel) ; 15(6)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35329574

RESUMO

Once administered in an organism, the physiological parameters of magnetic nanoparticles (MNPs) must be addressed, as well as their possible interactions and retention and elimination profiles. Alternating current biosusceptometry (ACB) is a biomagnetic detection system used to detect and quantify MNPs. The aims of this study were to evaluate the biodistribution and clearance of MNPs profiles through long-time in vivo analysis and determine the elimination time carried out by the association between the ACB system and MnFe2O4 nanoparticles. The liver, lung, spleen, kidneys, and heart and a blood sample were collected for biodistribution analysis and, for elimination analysis, and over 60 days. During the period analyzed, the animal's feces were also collectedd. It was possible to notice a higher uptake by the liver and the spleen due to their characteristics of retention and uptake. In 60 days, we observed an absence of MNPs in the spleen and a significant decay in the liver. We also determined the MNPs' half-life through the liver and the spleen elimination. The data indicated a concentration decay profile over the 60 days, which suggests that, in addition to elimination via feces, there is an endogenous mechanism of metabolization or possible agglomeration of MNPs, resulting in loss of ACB signal intensity.

17.
Sensors (Basel) ; 21(21)2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34770373

RESUMO

The use of magnetic nanoparticles (MNPs) in biomedical applications requires the quantitative knowledge of their quantitative distribution within the body. AC Biosusceptometry (ACB) is a biomagnetic technique recently employed to detect MNPs in vivo by measuring the MNPs response when exposed to an alternate magnetic field. The ACB technique presents some interesting characteristics: non-invasiveness, low operational cost, high portability, and no need for magnetic shielding. ACB conventional methods until now provided only qualitative information about the MNPs' mapping in small animals. We present a theoretical model and experimentally demonstrate the feasibility of ACB reconstructing 2D quantitative images of MNPs' distributions. We employed an ACB single-channel scanning approach, measuring at 361 sensor positions, to reconstruct MNPs' spatial distributions. For this, we established a discrete forward problem and solved the ACB system's inverse problem. Thus, we were able to determine the positions and quantities of MNPs in a field of view of 5×5×1 cm3 with good precision and accuracy. The results show the ACB system's capabilities to reconstruct the quantitative spatial distribution of MNPs with a spatial resolution better than 1 cm, and a sensitivity of 1.17 mg of MNPs fixed in gypsum. These results show the system's potential for biomedical application of MNPs in several studies, for example, electrochemical-functionalized MNPs for cancer cell targeting, quantitative sensing, and possibly in vivo imaging.


Assuntos
Nanopartículas de Magnetita , Animais , Diagnóstico por Imagem , Campos Magnéticos , Magnetismo , Cintilografia
18.
Nanomedicine (Lond) ; 16(24): 2189-2206, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34533056

RESUMO

Background: We evaluated the impacts of corona protein (CP) formation on the alternating current biosusceptometry (ACB) signal intensity and in vivo circulation times of three differently coated magnetic nanoparticles (MNP): bare, citrate-coated and bovine serum albumin-coated MNPs. Methods: We employed the ACB system, gel electrophoresis and mass spectrometry analysis. Results: Higher CP formation led to a greater reduction in the in vitro ACB signal intensity and circulation time. We found fewer proteins forming the CP for the bovine serum albumin-coated MNPs, which presented the highest circulation time in vivo among the MNPs studied. Conclusion: These data showed better biocompatibility, stability and magnetic signal uniformity in biological media for bovine serum albumin-coated MNPs than for citrate-coated MNPs and bare MNPs.


Assuntos
Nanopartículas de Magnetita , Coroa de Proteína , Materiais Biocompatíveis , Magnetismo , Soroalbumina Bovina
19.
Pharmaceutics ; 13(8)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34452233

RESUMO

Pharmacomagnetography involves the simultaneous assessment of solid dosage forms (SDFs) in the human gastrointestinal (GI) tract and the drug plasmatic concentration, using a biomagnetic technique and pharmacokinetics analysis. This multi-instrumental approach helps the evaluation, as GI variables can interfere with the drug delivery processes. This study aimed to employ pharmacomagnetography to evaluate the influence of omeprazole on the drug release and absorption of metronidazole administered orally in magnetic-coated tablets. Magnetic-coated tablets, coated with Eudragit® E-100 (E100) and containing 100 mg of metronidazole, were produced. For the in vivo experiments, 12 volunteers participated in the two phases of the study (placebo and omeprazole) on different days to assess the bioavailability of metronidazole. The results indicated a shift as the pH of the solution increased and a delay in the dissolution of metronidazole, showing that the pH increase interferes with the release processes of tablets coated with E100. Our study reinforced the advantages of pharmacomagnetography as a tool to perform a multi-instrumental correlation analysis of the disintegration process and the bioavailability of drugs.

20.
Rev. bras. ciênc. vet ; 28(3): 126-131, jul./set. 2021. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1491713

RESUMO

Este estudo objetivou avaliar o comportamento de cães de responsáveis brasileiros, através do Canine Behavioral Assessment and Research Questionnaire (C-BARQ) e estabelecer se estes comportamentos apresentam relação significativa com a idade, sexo e castração do animal. O questionário foi respondido pelos participantes entre novembro de 2018 a abril de 2020. As amostras foram divididas de acordo com o sexo (fêmeas ou machos), a idade (um ano ou menos, de um a três anos, de três a sete anos, de sete a dez anos ou mais de dez anos) e o status reprodutivo do animal (castrados ou inteiros). Para cada questionário respondido, foram calculados os escores das 14 categorias de comportamento investigados pelo C-BARQ e, através do programa Biostat 5.3, utilizou-se o coeficiente de correlação de Spearman com nível de significância de 5% para avaliar a correlação entre estes escores com os fatores idade, sexo e status reprodutivo dos animais. Os resultados sugerem maiores escores de comportamentos agressivos em cães mais velhos e em cães castrados. A castração também obteve associação com maiores escores de medo de outros cães. Os achados evidenciam necessidade de estudos que busquem investigar de que modo a castração se vincula com estes comportamentos que podem comprometer a convivência entre o responsável e seu cão.


This study investigated Brazilian’s dogs behavior through the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) and establish if these behaviors have a significant relationship with the age, sex and neutering status of the animal. The questionnaire was answered by owners between November 2018 and April 2020. The sample was divided according to sex (female or male), age (one year or less, from one to three years, from three to seven years, from seven to ten years or more than ten years) and the reproductive status of the animal (neutered or not). For each questionnaire answered, the scores of the 14 behavior categories investigated by C-BARQ were calculated and Spearman’s correlation coefficient with a significance level of 5% was used to assess the correlation between these scores with the factors age, sex and reproductive status of the animals (Biostat 5.3 program). The results suggest higher scores for aggressive behavior in older dogs and in neutered dogs. Neutering was also associated with higher scores of fear from other dogs. The findings suggest the need for studies that seek to investigate how castration is linked to these behaviors that can deteriorate the owner-dog relationship.


Assuntos
Masculino , Feminino , Animais , Cães , Castração/veterinária , Comportamento Animal , Cães , Distribuição por Idade e Sexo , Fenômenos Reprodutivos Fisiológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...