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1.
Eur J Immunol ; 52(1): 149-160, 2022 01.
Article in English | MEDLINE | ID: mdl-34695227

ABSTRACT

During the COVID-19 pandemic, Portugal has experienced three distinct SARS-CoV-2 infection waves. We previously documented the prevalence of SARS-CoV-2 immunity, measured by specific antibodies, in September 2020, 6 months after the initial moderate wave. Here, we show the seroprevalence changes 6 months later, up to the second week of March 2021, shortly following the third wave, which was one of the most severe in the world, and 2 months following the start of the vaccination campaign. A longitudinal epidemiological study was conducted, with a stratified quota sample of the Portuguese population. Serological testing was performed, including ELISA determination of antibody class and titers. The proportion of seropositives, which was 2.2% in September 2020, rose sharply to 17.3% (95% CI: 15.8-18.8%) in March 2021. Importantly, circulating IgG and IgA antibody levels were very stable 6 months after the initial determination and up to a year after initial infection, indicating long-lasting infection immunity against SARS-CoV-2. Moreover, vaccinated people had higher IgG levels from 3 weeks post-vaccination when compared with previously infected people at the same time post-infection.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Serological Testing , COVID-19 , Immunoglobulin A/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adolescent , Adult , COVID-19/epidemiology , COVID-19/immunology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Portugal/epidemiology , Prevalence , Time Factors
2.
Proc Biol Sci ; 290(2011): 20231739, 2023 Nov 29.
Article in English | MEDLINE | ID: mdl-37989240

ABSTRACT

Predicting the spatial occurrence of wildlife is a major challenge for ecology and management. In Latin America, limited knowledge of the number and locations of vampire bat roosts precludes informed allocation of measures intended to prevent rabies spillover to humans and livestock. We inferred the spatial distribution of vampire bat roosts while accounting for observation effort and environmental effects by fitting a log Gaussian Cox process model to the locations of 563 roosts in three regions of Peru. Our model explained 45% of the variance in the observed roost distribution and identified environmental drivers of roost establishment. When correcting for uneven observation effort, our model estimated a total of 2340 roosts, indicating that undetected roosts (76%) exceed known roosts (24%) by threefold. Predicted hotspots of undetected roosts in rabies-free areas revealed high-risk areas for future viral incursions. Using the predicted roost distribution to inform a spatial model of rabies spillover to livestock identified areas with disproportionate underreporting and indicated a higher rabies burden than previously recognized. We provide a transferrable approach to infer the distribution of a mostly unobserved bat reservoir that can inform strategies to prevent the re-emergence of an important zoonosis.


Subject(s)
Chiroptera , Rabies virus , Rabies , Animals , Humans , Rabies/epidemiology , Rabies/veterinary , Rabies/prevention & control , Zoonoses , Latin America , Livestock
3.
BMC Pregnancy Childbirth ; 23(1): 661, 2023 Sep 13.
Article in English | MEDLINE | ID: mdl-37704954

ABSTRACT

INTRODUCTION: Birth weight is described as one of the main determinants of newborns' chances of survival. Among the associated causes, or risk factors, the mother's nutritional status strongly influences fetal growth and birth weight outcomes of the concept. This study evaluates the association between food deserts, small for gestational age (SGA), large for gestational age (LGA) and low birth weight (LBW) newborns. DESIGN: This is a cross-sectional population study, resulting from individual data from the Live Birth Information System (SINASC), and commune data from mapping food deserts (CAISAN) in Brazil. The newborn's size was defined as follows: appropriate for gestational age (between 10 and 90th percentile), SGA (< 10th percentile), LGA (> 90th percentile), and low birth weight < 2,500 g. To characterize food environments, we used tertiles of the density of establishments which sell in natura and ultra-processed foods. Logistic regression modeling was conducted to investigate the associations of interest. RESULTS: We analyzed 2,632,314 live births in Brazil in 2016, after appropriate adjustments, women living in municipalities with limited availability of fresh foods had a higher chance of having newborns with SGA [OR2nd tertile: 1.06 (1.05-1.07)] and LBW [OR2nd tertile: 1.11 (1.09-1.12)]. Conversely, municipalities with greater availability of ultra-processed foods had a higher chance of having newborns with SGA [OR3rd tertile: 1.04 (1.02-1.06)] and LBW [OR2nd tertile: 1.13 (1.11-1.16)]. Stratification by race showed that Black and Mixed/Brown women had a higher chance of having newborns with SGA [OR3rd tertile: 1.09 (1.01-1.18)] and [OR3rd tertile: 1.06 (1.04-1.09)], respectively, while Mixed-race women also had a higher chance of having newborns with LBW [OR3rd tertile: 1.17 (1.14-1.20)]. Indigenous women were associated with LGA [OR3rd tertile: 1.20 (1.01-1.45)]. CONCLUSION: The study found that living in areas with limited access to healthy foods was associated with an increased risk of SGA and low birth weight among newborns, particularly among Black and Mixed/Brown women. Therefore, urgent initiatives aimed at reducing social inequalities and mitigating the impact of poor food environments are needed in Brazil.


Subject(s)
Fetal Development , Food , Infant, Newborn , Pregnancy , Female , Humans , Brazil/epidemiology , Birth Weight , Cross-Sectional Studies
4.
Sensors (Basel) ; 23(10)2023 May 19.
Article in English | MEDLINE | ID: mdl-37430815

ABSTRACT

The early detection of fire is of utmost importance since it is related to devastating threats regarding human lives and economic losses. Unfortunately, fire alarm sensory systems are known to be prone to failures and frequent false alarms, putting people and buildings at risk. In this sense, it is essential to guarantee smoke detectors' correct functioning. Traditionally, these systems have been subject to periodic maintenance plans, which do not consider the state of the fire alarm sensors and are, therefore, sometimes carried out not when necessary but according to a predefined conservative schedule. Intending to contribute to designing a predictive maintenance plan, we propose an online data-driven anomaly detection of smoke sensors that model the behaviour of these systems over time and detect abnormal patterns that can indicate a potential failure. Our approach was applied to data collected from independent fire alarm sensory systems installed with four customers, from which about three years of data are available. For one of the customers, the obtained results were promising, with a precision score of 1 with no false positives for 3 out of 4 possible faults. Analysis of the remaining customers' results highlighted possible reasons and potential improvements to address this problem better. These findings can provide valuable insights for future research in this area.

5.
Pharmacol Res ; 175: 106026, 2022 01.
Article in English | MEDLINE | ID: mdl-34890775

ABSTRACT

The growing incidence of skin cancer (SC) has prompted the search for additional preventive strategies to counteract this global health concern. Mutant p53 (mutp53), particularly with ultraviolet radiation (UVR) signature, has emerged as a promising target for SC prevention based on its key role in skin carcinogenesis. Herein, the preventive activity of our previously disclosed mutp53 reactivator SLMP53-2 against UVR-induced SC was investigated. The pre-treatment of keratinocyte HaCaT cells with SLMP53-2, before UVB exposure, depleted mutp53 protein levels with restoration of wild-type-like p53 DNA-binding ability and subsequent transcriptional activity. SLMP53-2 increased cell survival by promoting G1-phase cell cycle arrest, while reducing UVB-induced apoptosis through inhibition of c-Jun N-terminal kinase (JNK) activity. SLMP53-2 also protected cells from reactive oxygen species and oxidative damage induced by UVB. Moreover, it enhanced DNA repair through upregulation of nucleotide excision repair pathway and depletion of UVB-induced DNA damage, as evidenced by a reduction of DNA in comet tails, γH2AX staining and cyclobutane pyrimidine dimers (CPD) levels. SLMP53-2 further suppressed UVB-induced inflammation by inhibiting the nuclear translocation and DNA-binding ability of NF-κB, and promoted the expression of key players involved in keratinocytes differentiation. Consistently, the topical application of SLMP53-2 in mice skin, prior to UVB irradiation, reduced cell death and DNA damage. It also decreased the expression of inflammatory-related proteins and promoted cell differentiation, in UVB-exposed mice skin. Notably, SLMP53-2 did not show signs of skin toxicity for cumulative topical use. Overall, these results support a promising protective activity of SLMP53-2 against UVB-induced SC.


Subject(s)
Neoplasms, Radiation-Induced , Radiation-Protective Agents , Skin Neoplasms , Tumor Suppressor Protein p53 , Ultraviolet Rays , Animals , Female , Humans , Mice , Carcinogenesis , Cell Cycle Checkpoints/drug effects , Cell Differentiation/drug effects , Cell Line , Cell Survival/drug effects , DNA Repair , Interleukin-6/immunology , Keratinocytes/drug effects , Keratinocytes/radiation effects , Mutation , Neoplasms, Radiation-Induced/immunology , Neoplasms, Radiation-Induced/pathology , Neoplasms, Radiation-Induced/prevention & control , Radiation-Protective Agents/pharmacology , Radiation-Protective Agents/therapeutic use , Skin/immunology , Skin/pathology , Skin Neoplasms/immunology , Skin Neoplasms/pathology , Skin Neoplasms/prevention & control , Tumor Suppressor Protein p53/genetics
6.
Eur J Clin Microbiol Infect Dis ; 41(12): 1371-1385, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36198878

ABSTRACT

Nowadays, fungal infections affect millions of people across the world. Candida auris, a new emergent yeast, is a worrisome pathogen because it associates with a high rate of incidence and prevalence, including in the nosocomial environment. The hard identification, the phenotypic plasticity, and the easy adaptation to stressful conditions are some of the C. auris traits that render this latest yeast singular challenging. C. auris infections have already been reported from more than 30 countries and are associated with high mortality rates. This is the result from rapid transmission and the difficulty of prevention, control, and eradication. There are several factors related to the high virulence of C. auris, such as the multidrug resistance, biofilm development, and the ability to escape the response of the innate immune system. So, C. auris infections are a serious and alarming problem, not only because of the high pathogenicity of the fungal agent but also because of the low effectiveness of the treatments available. Although new formulations have been developed against C. auris strains, a better understanding is essential to efficiently treat, prevent, and control C. auris infections.


Subject(s)
Candida auris , Candida , Humans , Saccharomyces cerevisiae , Biofilms , Virulence , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Microbial Sensitivity Tests
7.
Drug Chem Toxicol ; 45(4): 1787-1795, 2022 Jul.
Article in English | MEDLINE | ID: mdl-33494633

ABSTRACT

Vitex megapotamica (Spreng.) Moldenke is a plant with medicinal properties popularly used in Brazil to treat diabetes and obesity. Despite the promising use of this plant, are still incipient toxicology studies on prolonged periods of treatment. The aim of this study was to evaluate the repeated dose 90-day oral toxicity study of V. megapotamica methanolic extract (VMME) in male and female Wistar rats. Different groups of rats (n = 8) were treated daily with three different doses of VMME (100, 300, and 900 mg/kg) or vehicle (filtered water). Body weight, water, and feed consumption, and clinical and behavioral changes were monitored daily. At the end of the experimental period, blood samples were obtained for hematological and biochemical analyzes. After euthanasia, the vital organs were removed for the determination of relative weight and for histopathological analysis. No clinical signs of toxicity or mortality were found during the experimental period. Treatment with VMME did not induce any change in body weight gain, eating patterns, and behavior. We found no statistically significant changes in the different hematological and biochemical parameters evaluated. The relative weight of the organs and histopathological analysis did not show any significant change when compared to animals treated with the vehicle. The data obtained in this study allow us to conclude that the VMME obtained from V. megapotamica is safe after a repeated-dose 90-day oral toxicity study in male and female Wistar rats.


Subject(s)
Vitex , Administration, Oral , Animals , Body Weight , Female , Male , Methanol , Plant Extracts/chemistry , Plant Leaves/chemistry , Rats , Rats, Wistar , Toxicity Tests, Acute , Vitex/chemistry , Water
8.
Emerg Infect Dis ; 27(11): 2878-2881, 2021 11.
Article in English | MEDLINE | ID: mdl-34437830

ABSTRACT

In September 2020, we tested 13,398 persons in Portugal for antibodies against severe acute respiratory syndrome coronavirus 2 by using a quota sample stratified by age and population density. We found a seroprevalence of 2.2%, 3-4 times larger than the official number of cases at the end of the first wave of the pandemic.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Pandemics , Portugal/epidemiology , Prevalence , Seroepidemiologic Studies
9.
Photochem Photobiol Sci ; 20(8): 1027-1032, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34292539

ABSTRACT

The search for new materials that can be applied in the treatment of injured human tissues has led to the development of new dressings. Membranes have potential as dressing materials because they can be fitted to and interact with the tissue surface. In this study, we analyze the morphological properties and wettability of latex membranes, along with the incorporation of the photosensitizer methylene blue, in the context of the utility of the membranes in curative applications involving photodynamic therapy (PDT). It was observed that deposition of the photosensitizer into latex membranes increased both the surface roughness and wettability. Antifungal testing indicated that antimicrobial PDT assisted by the latex membranes incorporating methylene blue effectively inactivated Candida albicans.


Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Coloring Agents/chemistry , Latex , Membranes, Artificial , Methylene Blue/chemistry , Methylene Blue/pharmacology , Candida albicans/drug effects , Candida albicans/radiation effects , Photochemotherapy
10.
Drug Chem Toxicol ; 44(4): 380-385, 2021 Jul.
Article in English | MEDLINE | ID: mdl-31060457

ABSTRACT

Malaria is a global public health problem that causes approximately 445 000 deaths annually worldwide, especially in underdeveloped countries. Because of the high prevalence and mortality of the disease, new and less toxic therapeutic agents need to be developed, such as MEFAS, a low-cost hybrid salt that consists of artesunate and mefloquine. However, the efficacy of MEFAS has been systematically demonstrated, its safety requires further investigation. This study investigated the acute toxicity of MEFAS and its precursors, artesunate, and mefloquine. A total of 42 female Swiss mice were divided into seven groups (n = 6/group) that were treated orally by gavage with vehicle (filtered water, negative control), MEFAS (50, 500, and 1000 mg/kg), and 1:1 concentrations of artesunate + mefloquine (50, 500, and 1000 mg/kg). Clinical signs of toxicity were observed for 14 d after treatment. On day 15, the animals were weighed, deeply anesthetized with isoflurane, and euthanized for subsequent collection of the liver, spleen, and kidneys. The relative organ weights were determined, followed by histopathological analysis. Artesunate + mefloquine produced toxic effects compared with the negative control group, reflected by changes in clinical signs, relative organ weights, and histopathological alterations. In MEFAS-treated animals, no changes were observed compared with the negative control group. These findings demonstrate that MEFAS is safer than artesunate + mefloquine after acute administration in mice.


Subject(s)
Antimalarials/toxicity , Artesunate/toxicity , Mefloquine/toxicity , Animals , Antimalarials/administration & dosage , Artesunate/administration & dosage , Dose-Response Relationship, Drug , Drug Combinations , Drug Therapy, Combination , Female , Mefloquine/administration & dosage , Mice
11.
Sensors (Basel) ; 21(17)2021 Aug 26.
Article in English | MEDLINE | ID: mdl-34502630

ABSTRACT

In the last few years, many works have addressed Predictive Maintenance (PdM) by the use of Machine Learning (ML) and Deep Learning (DL) solutions, especially the latter. The monitoring and logging of industrial equipment events, like temporal behavior and fault events-anomaly detection in time-series-can be obtained from records generated by sensors installed in different parts of an industrial plant. However, such progress is incipient because we still have many challenges, and the performance of applications depends on the appropriate choice of the method. This article presents a survey of existing ML and DL techniques for handling PdM in the railway industry. This survey discusses the main approaches for this specific application within a taxonomy defined by the type of task, employed methods, metrics of evaluation, the specific equipment or process, and datasets. Lastly, we conclude and outline some suggestions for future research.


Subject(s)
Industry , Machine Learning , Surveys and Questionnaires
12.
Diabetologia ; 63(4): 825-836, 2020 04.
Article in English | MEDLINE | ID: mdl-31873789

ABSTRACT

AIMS/HYPOTHESIS: Type 1 diabetes is characterised by a progressive decline in beta cell mass. This is also observed following implantation of pancreatic islet allografts, but there is no reliable information regarding the time course of beta cell loss. This is due to the limited availability of non-invasive pancreatic islet imaging techniques. We have previously described that dipeptidyl peptidase 6 (DPP6) is an alpha and beta cell-specific biomarker, and developed a camelid antibody (nanobody '4hD29') against it. We demonstrated the possibility to detect DPP6-expressing cells by single-photon emission computed tomography (SPECT)/ computed tomography (CT), but the correlation between the number of cells grafted and the SPECT signal was not assessed. Here, we investigate whether the 4hD29 nanobody allows us to detect different amounts of human pancreatic islets implanted into immune-deficient mice. In addition, we also describe the adaptation of the probe for use with positron emission tomography (PET). METHODS: DPP6 expression was assessed in human samples using tissue arrays and immunohistochemistry. The effect of the 4hD29 nanobody on cell death and glucose-stimulated insulin secretion was measured in EndoC-ßH1 cells and in human islets using Hoechst/propidium iodide staining and an anti-insulin ELISA, respectively. We performed in vivo SPECT imaging on severe combined immunodeficient (SCID) mice transplanted with different amounts of EndoC-ßH1 cells (2 × 106, 5 × 106 and 10 × 106 cells), human islets (1000 and 3000) or pancreatic exocrine tissue using 99mTc-labelled 4hD29 nanobody. This DPP6 nanobody was also conjugated to N-chlorosuccinimide (NCS)-1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), radiolabelled with either 67Ga (SPECT) or 68Ga (PET) and used in a proof-of-principle experiment to detect DPP6-expressing cells (Kelly neuroblastoma) grafted in SCID mice. RESULTS: The DPP6 protein is mainly expressed in pancreatic islets. Importantly, the anti-DPP6 nanobody 4hD29 allows non-invasive detection of high amounts of EndoC-ßH1 cells or human islets grafted in immunodeficient mice. This suggests that the probe must be further improved to detect lower numbers of islet cells. The 4hD29 nanobody neither affected beta cell viability nor altered insulin secretion in EndoC-ßH1 cells and human islets. The conversion of 4hD29 nanobody into a PET probe was successful and did not alter its specificity. CONCLUSIONS/INTERPRETATION: These findings suggest that the anti-DPP6 4hD29 nanobody may become a useful tool for the quantification of human islet grafts in mice and, pending future development, islet mass in individuals with diabetes.


Subject(s)
Cell Tracking/methods , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/immunology , Insulin-Secreting Cells/metabolism , Islets of Langerhans Transplantation , Islets of Langerhans/diagnostic imaging , Single-Domain Antibodies/pharmacology , Animals , Cell Count , Cells, Cultured , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/antagonists & inhibitors , Female , Gallium Radioisotopes/analysis , Gallium Radioisotopes/pharmacokinetics , Heterografts , Humans , Insulin-Secreting Cells/cytology , Islets of Langerhans/cytology , Islets of Langerhans/metabolism , Mice , Mice, Inbred C57BL , Mice, SCID , Mice, Transgenic , Molecular Imaging/methods , Organotechnetium Compounds/chemistry , Organotechnetium Compounds/pharmacokinetics , Radioactive Tracers , Single Photon Emission Computed Tomography Computed Tomography/methods , Single-Domain Antibodies/analysis , Single-Domain Antibodies/chemistry
13.
Biotechnol Appl Biochem ; 66(3): 419-425, 2019 May.
Article in English | MEDLINE | ID: mdl-30758071

ABSTRACT

Fructooligosaccharides (FOS) are fructose-based oligosaccharides employed as additives to improve the nutritional and technological properties of foods. The rhizosphere of inulin-accumulating plants from the Cerrado (Brazilian savanna) harbor fungi capable of synthesizing FOS from sucrose through the transfructosylating activity of ß-fructosyltransferases and/or ß-fructofuranosidases. Here, we investigated the ability of Penicillium janczewskii Zaleski CCIBt 3352, a fungus isolated from the rhizosphere of Chrysolaena obovata (Asteraceae), to produce FOS in a medium supplemented with sucrose concentrations of 30, 100, or 150 g L-1 . Hydrolytic activity on sucrose was observed in culture filtrates; however, at 150 g L-1 sucrose, the accumulation of 8 g L-1 1-kestose (inulin-type FOS) and 7.3 g L-1 neokestose (neolevan-type FOS) was observed, the latter being a type of FOS not commonly produced by filamentous fungi. In addition, minor amounts of four unidentified oligosaccharides, with a high degree of polymerization, were detected. The production of FOS was also observed in enzymatic assays, indicating the presence of extracellular enzymes with transfructosylating activity in the culture filtrates. Our findings demonstrate the feasibility of isolating promising microorganisms, for the production of FOS-synthesizing enzymes, from the rhizosphere of fructan-producing plants of the Brazilian Cerrado.


Subject(s)
Fructans/metabolism , Inulin/metabolism , Oligosaccharides/biosynthesis , Oligosaccharides/chemistry , Penicillium/metabolism , Asteraceae/microbiology , Brazil , Fructans/chemistry , Inulin/chemistry , Molecular Structure , Oligosaccharides/metabolism , Penicillium/chemistry , Penicillium/growth & development
14.
Int J Mol Sci ; 20(16)2019 Aug 10.
Article in English | MEDLINE | ID: mdl-31405112

ABSTRACT

Carcinogenesis induced by high-risk human papillomavirus (HPV) involves inflammatory phenomena, partially mediated by cyclooxigenase-2. In pre-clinical models of HPV-induced cancer, cyclooxygenase-2 inhibitors have shown significant efficacy, but also considerable toxicity. This study addresses the chemopreventive effect and hepatic toxicity of a specific cyclooxigensase-2 inhibitor, parecoxib, in HPV16-transgenic mice. Forty-three 20 weeks-old female mice were divided into four groups: I (HPV16-/-, n = 10, parecoxib-treated); II (HPV16-/- n = 11, untreated); III (HPV16+/-, n = 11, parecoxib-treated) and IV (HPV16+/-, n = 11, untreated). Parecoxib (5.0 mg/kg once daily) or vehicle was administered intraperitoneally for 22 consecutive days. Skin lesions were classified histologically. Toxicological endpoints included genotoxic parameters, hepatic oxidative stress, transaminases and histology. Parecoxib completely prevented the onset of epidermal dysplasia in HPV16+/- treated animals (0% versus 64% in HPV16+/- untreated, p = 0.027). Parecoxib decreases lipid peroxidation (LPO) and superoxide dismutase (SOD) activity and increases the GSH:GSSG ratio in HPV16+/- treated animals meaning that oxidative stress is lower. Parecoxib increased genotoxic stress parameters in wild-type and HPV16-transgenic mice, but didn't modify histological or biochemical hepatic parameters. These results indicate that parecoxib has chemopreventive effects against HPV16-induced lesions while maintaining an acceptable toxicological profile in this model.


Subject(s)
Anticarcinogenic Agents/therapeutic use , Cyclooxygenase 2 Inhibitors/therapeutic use , Human papillomavirus 16/isolation & purification , Isoxazoles/therapeutic use , Skin Neoplasms/prevention & control , Skin Neoplasms/virology , Animals , Anticarcinogenic Agents/adverse effects , Cyclooxygenase 2 Inhibitors/adverse effects , Female , Human papillomavirus 16/genetics , Isoxazoles/adverse effects , Mice , Mice, Transgenic , Papillomavirus Infections/complications , Papillomavirus Infections/pathology , Skin/drug effects , Skin/pathology , Skin/virology , Skin Neoplasms/pathology
15.
Planta Med ; 84(17): 1271-1279, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29929207

ABSTRACT

Excess weight and dyslipidemia are among the most serious health problems in Western societies. These conditions enhance the risk of cardiac disease and have been linked with a higher prevalence of cardiac arrhythmias and sudden death. The present study investigated the cardioprotective effects of Echinodorus grandiflorus on ventricular remodeling in rabbits that were fed a 1% cholesterol-rich diet. We first obtained an ethanol-soluble fraction of E. grandiflorus and performed a detailed phytochemical study by liquid chromatography-DAD/ESI-MS. For 60 days, male rabbits were fed the cholesterol-rich diet or a diet without the addition of cholesterol. After 30 days, different groups of rabbits were treated with the ethanol-soluble fraction of E. grandiflorus (10, 30, and 100 mg/kg, p. o.), simvastatin (2.5 mg/kg), or vehicle once daily for 30 days. At the end of 60 days, the serum lipoprotein ratio, electrocardiographic profile, histopathological alterations, and the cardiac antioxidant defense system were investigated. Echocardiographic analysis showed morphological and functional alterations in cholesterol-rich diet-fed animals, indicating left ventricle hypertrophy. The total cholesterol/high-density lipoprotein ratio and low-density lipoprotein/high-density lipoprotein ratio were significantly higher in cholesterol-rich diet-fed rabbits. Myocardial flaccidity, fatty degeneration, and concentric left ventricular hypertrophy were observed. An increase in lipid peroxidation levels, a decrease in superoxide dismutase activity, and a decrease in reduced glutathione levels were observed in the myocardium of all cholesterol-rich diet-fed rabbits. Treatment with the ethanol-soluble fraction of E. grandiflorus, especially the highest dose, significantly reduced all of these alterations, thus demonstrating the cardioprotective effect of the ethanol-soluble fraction of E. grandiflorus on cardiac changes that are induced by a cholesterol-rich diet.


Subject(s)
Alismataceae , Atherosclerosis/drug therapy , Cardiotonic Agents/therapeutic use , Cholesterol, Dietary/antagonists & inhibitors , Plant Extracts/therapeutic use , Animals , Atherosclerosis/pathology , Cholesterol, Dietary/adverse effects , Cholesterol, Dietary/pharmacology , Disease Models, Animal , Electrocardiography , Heart/anatomy & histology , Heart/drug effects , Lipoproteins/blood , Male , Rabbits
16.
Sensors (Basel) ; 18(9)2018 Aug 21.
Article in English | MEDLINE | ID: mdl-30134569

ABSTRACT

Optical fiber tweezers have been gaining prominence in several applications in Biology and Medicine. Due to their outstanding focusing abilities, they are able to trap and manipulate microparticles, including cells, needing any physical contact and with a low degree of invasiveness to the trapped cell. Recently, we proposed a fiber tweezer configuration based on a polymeric micro-lens on the top of a single mode fiber, obtained by a self-guided photopolymerization process. This configuration is able to both trap and identify the target through the analysis of short-term portions of the back-scattered signal. In this paper, we propose a variant of this fabrication method, capable of producing more robust fiber tips, which produce stronger trapping effects on targets by as much as two to ten fold. These novel lenses maintain the capability of distinguish the different classes of trapped particles based on the back-scattered signal. This novel fabrication method consists in the introduction of a multi mode fiber section on the tip of a single mode (SM) fiber. A detailed description of how relevant fabrication parameters such as the length of the multi mode section and the photopolymerization laser power can be tuned for different purposes (e.g., microparticles trapping only, simultaneous trapping and sensing) is also provided, based on both experimental and theoretical evidences.


Subject(s)
Equipment Design , Optical Tweezers , Polymers , Single-Cell Analysis/instrumentation , Single-Cell Analysis/methods , Lasers , Lenses , Optical Fibers , Yeasts/cytology
17.
Sensors (Basel) ; 18(3)2018 Feb 27.
Article in English | MEDLINE | ID: mdl-29495502

ABSTRACT

Recent trends on microbiology point out the urge to develop optical micro-tools with multifunctionalities such as simultaneous manipulation and sensing. Considering that miniaturization has been recognized as one of the most important paradigms of emerging sensing biotechnologies, optical fiber tools, including Optical Fiber Tweezers (OFTs), are suitable candidates for developing multifunctional small sensors for Medicine and Biology. OFTs are flexible and versatile optotools based on fibers with one extremity patterned to form a micro-lens. These are able to focus laser beams and exert forces onto microparticles strong enough (piconewtons) to trap and manipulate them. In this paper, through an exploratory analysis of a 45 features set, including time and frequency-domain parameters of the back-scattered signal of particles trapped by a polymeric lens, we created a novel single feature able to differentiate synthetic particles (PMMA and Polystyrene) from living yeasts cells. This single statistical feature can be useful for the development of label-free hybrid optical fiber sensors with applications in infectious diseases detection or cells sorting. It can also contribute, by revealing the most significant information that can be extracted from the scattered signal, to the development of a simpler method for particles characterization (in terms of composition, heterogeneity degree) than existent technologies.

18.
Drug Chem Toxicol ; 40(3): 281-285, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27482986

ABSTRACT

The prevalence of the use of herbal medicines is on the rise across the world, especially amongst pregnant women. A fact that draws attention is that many species commonly used by pregnant women, including the Tropaeolum majus L. (Tropaeolaceae), also present inhibitory activity on the angiotensin-converting enzyme (ACE). Herein, we have investigated the effects of T. majus extract (HETM) on fetal development, evaluating its relationship with possible ACE inhibitory activity. Pregnant Wistar rats were treated with different HETM doses (3, 30 and 300 mg/kg/day) from gestational days 8-20. Rats were sacrificed on the day 20 of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights, maternal ACE activity and aldosterone levels, live fetuses mean; dead fetuses percentage, fetus weight, and fetal malformation. All pregnant rats treated with high HETM doses showed significant reduction in plasma ACE activity accompanied by a decrease in serum aldosterone levels. Moreover, significant changes in fetal development were observed, including growth retardation and renal damage after 20 days of gestation. Thus, data presented demonstrate the significant effects of the use of HETM on fetal development during pregnancy.


Subject(s)
Abnormalities, Drug-Induced/etiology , Angiotensin-Converting Enzyme Inhibitors/toxicity , Fetal Development/drug effects , Fetal Growth Retardation/chemically induced , Plant Extracts/toxicity , Tropaeolum/chemistry , Angiotensin-Converting Enzyme Inhibitors/isolation & purification , Animals , Dose-Response Relationship, Drug , Female , Gestational Age , Maternal Exposure/adverse effects , Plant Extracts/isolation & purification , Pregnancy , Rats, Wistar
19.
Opt Lett ; 41(10): 2137-40, 2016 May 15.
Article in English | MEDLINE | ID: mdl-27176946

ABSTRACT

This Letter reports a new method for the generation of optical vortices using a micropatterned optical fiber tip. Here, a spiral phase plate (2π phase shift) is micromachined on the tip of an optical fiber using a focused ion beam. This is a high resolution method that allows milling the fibers with nanoscale resolution. The plate acts as a beam tailoring system, transforming the fundamental guided mode, specifically a Gaussian mode, into the Laguerre-Gaussian mode (LG01), which carries orbital angular momentum. The experimental results are supported by computational simulations based on the finite-difference time-domain method.

20.
An Acad Bras Cienc ; 87(2): 797-812, 2015.
Article in English | MEDLINE | ID: mdl-26062118

ABSTRACT

Among the compounds stored by plants, several functions are assigned to fructans, such as source of energy and protection against drought and extreme temperatures. In the present study we analyzed the anatomy and distribution of fructans in vegetative organs of Dimerostemma vestitum (Asteraceae), an endemic species from the Brazilian campos rupestres. D. vestitumhas amphistomatic and pubescent leaves, with both glandular and non-glandular trichomes. In the basal aerial stem the medulla has two types of parenchyma, which differ from the apical portion. The xylopodium has mixed anatomical origin. Interestingly, although inulin-type fructans with high degree of polymerization were found in all analyzed organs except the leaves, the highest amount and maximum degree of polymerization were detected in the xylopodium. Inulin sphero-crystals were visualized under polarized light in the medulla and in the vascular tissues mainly in the central region of the xylopodium, which has abundant xylem parenchyma. Secretory structures accumulating several compounds but not inulin were identified within all the vegetative organs. The presence of these compounds, in addition to inulin, might be related to the strategies of plants to survive adverse conditions in a semi-arid region, affected seasonally by water restriction and frequently by fire.


Subject(s)
Asteraceae/anatomy & histology , Asteraceae/metabolism , Fructans/metabolism , Adaptation, Physiological , Asteraceae/classification , Brazil , Fructans/analysis , Seasons
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