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1.
J Exp Biol ; 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39422000

RESUMO

Marine heatwaves (MHW) have recently been proposed as more relevant in driving population changes than the continuous increase in average temperatures associated with climate change. The causal processes underpinning MHW effects in sharks are unclear but may be linked to changes in fitness caused by physiological trade-offs that influence the immune response. Considering the scarcity of data about the immune response of sharks under anomalous warming events, the present study analyzed several fitness indices and characterized the immune response (in the blood, epigonal organ, liver, spleen, and intestine) of temperate adult small-spotted catsharks (Scyliorhinus canicula) after a 30-day exposure to a Category II MHW. The results indicated that adult small-spotted catsharks have developed coping strategies for the MHW. Specifically, among the 35 parameters investigated, only the gonad-to-body ratio (GBR) and plasma glucose showed significant increases. In contrast, igm and tumor necrosis factor receptor (tnfr) gene expression in blood cells, tnfr in the epigonal organ, and the number of monocytes significantly decreased. Although a decline in immune function in small-spotted catsharks was revealed following the MHW exposure, energy mobilization restored homeostasis and indicated a shift in energy allocation towards reproduction. Group resilience may be due to the variable tolerance of individuals, the phenotypic plasticity of cellular immunity, thermal imprinting, and/or metabolic capacity of the individuals.

2.
Molecules ; 21(8)2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27483224

RESUMO

We previously reported that prenylated chalcone 2 (PC2), the O-prenyl derivative (2) of 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (1), induced cytotoxicity of tumor cells via disruption of p53-MDM2 interaction. However, the cellular changes through which PC2 exerts its cytotoxic activity and its antitumor potential, remain to be addressed. In the present work, we aimed to (i) characterize the effect of PC2 on mitotic progression and the underlying mechanism; and to (ii) explore this information to evaluate its ability to sensitize tumor cells to paclitaxel in a combination regimen. PC2 was able to arrest breast adenocarcinoma MCF-7 and non-small cell lung cancer NCI-H460 cells in mitosis. All mitosis-arrested cells showed collapsed mitotic spindles with randomly distributed chromosomes, and activated spindle assembly checkpoint. Live-cell imaging revealed that the compound induced a prolonged delay (up to 14 h) in mitosis, culminating in massive cell death by blebbing. Importantly, PC2 in combination with paclitaxel enhanced the effect on cell growth inhibition as determined by cell viability and proliferation assays. Our findings demonstrate that the cytotoxicity induced by PC2 is mediated through antimitotic activity as a result of mitotic spindle damage. The enhancement effects of PC2 on chemosensitivity of cancer cells to paclitaxel encourage further validation of the clinical potential of this combination.


Assuntos
Chalcona , Mitose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Paclitaxel/farmacologia , Prenilação , Chalcona/síntese química , Chalcona/química , Chalcona/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células MCF-7 , Neoplasias/metabolismo , Fuso Acromático/metabolismo
3.
Vet Res Commun ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39259416

RESUMO

Lyme disease (LD) is a globally distributed zoonotic multisystemic condition caused by gram-negative spirochete bacteria of the Borrelia burgdorferi complex, transmitted through tick bites. Research on LD in domestic animals in Portugal is limited, potentially leading to underestimating its prevalence. This disease affects many species, including humans, making it a critical public health issue. In domestic animals, LD often presents subclinically or with non-specific clinical signs, complicating its diagnosis. Nevertheless, veterinarians should always consider LD in cases with a history of tick exposure and compatible clinical signs. Diagnostic confirmation can be achieved through serological and other complementary tests. Treatment involves eradicating the bacterial infection and managing clinical signs using a combination of antibiotics, analgesics, anti-inflammatories, and other medications. Effective prevention primarily relies on tick control measures. This review aims to provide an up-to-date state-of-the-art LD, particularly in Portugal.

4.
Vet Clin Pathol ; 52(2): 324-333, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36975170

RESUMO

A 9-year-old neutered male cat, previously test-positive for feline immunodeficiency virus (FIV), was presented with an history of vomiting, hyporexia, and weight loss. Panleukopenia was identified on complete blood counts, and bone marrow evaluation revealed ineffective granulocytic hyperplasia and rare neutro-, erythro-, and rubriphagocytosis. Prednisolone was initiated with no response, and progression to pancytopenia occurred. On abdominal ultrasonographic examination, splenomegaly was present. PCR testing was positive for Candidatus Mycoplasma haemominutum and IgG antibodies against Toxoplasma gondii were detected (titer 1:2560). Treatment with antibiotics, feline recombinant interferon-ω, chlorambucil, mycophenolate, and raltegravir was implemented with no clinical improvement, and splenectomy was performed. Cytologic evaluation of splenic aspirates revealed exuberant neutro-, erythro-, and rubriphagocytosis. Histopathology of the spleen also showed many erythrophagocytic macrophages with no evidence of malignancy, and a diagnosis of hemophagocytic syndrome (HS) was made. The WBC count and hematocrit reached reference values 1 day and 3 months, respectively, after splenectomy. The cat was treated with cyclosporine and lomustine. Disease progression led to the development of septic hepatitis, and the cat was euthanized. To our knowledge, this is the first case of presumptive HS in cats that might have been associated with FIV, Toxoplasma gondii, and Candidatus Mycoplasma haemominutum co-infection.


Assuntos
Doenças do Gato , Coinfecção , Vírus da Imunodeficiência Felina , Linfo-Histiocitose Hemofagocítica , Infecções por Mycoplasma , Mycoplasma , Toxoplasma , Animais , Gatos , Masculino , Linfo-Histiocitose Hemofagocítica/complicações , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/veterinária , Coinfecção/diagnóstico , Coinfecção/veterinária , Infecções por Mycoplasma/complicações , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/veterinária , Doenças do Gato/diagnóstico
5.
J Imaging ; 8(3)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35324627

RESUMO

This article compares measurements of particle shape parameters from three-dimensional (3D) X-ray micro-computed tomography (µCT) and two-dimensional (2D) dynamic image analysis (DIA) from the optical microscopy of a coastal bioclastic calcareous sand from Western Australia. This biogenic sand from a high energy environment consists largely of the shells and tests of marine organisms and their clasts. A significant difference was observed between the two imaging techniques for measurements of aspect ratio, convexity, and sphericity. Measured values of aspect ratio, sphericity, and convexity are larger in 2D than in 3D. Correlation analysis indicates that sphericity is correlated with convexity in both 2D and 3D. These results are attributed to inherent limitations of DIA when applied to platy sand grains and to the shape being, in part, dependent on the biology of the grain rather than a purely random clastic process, like typical siliceous sands. The statistical data has also been fitted to Johnson Bounded Distribution for the ease of future use. Overall, this research demonstrates the need for high-quality 3D microscopy when conducting a micromechanical analysis of biogenic calcareous sands.

6.
Animals (Basel) ; 12(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36496958

RESUMO

The purpose of this study was to investigate stressful responses during a 6-week training protocol in young Lusitano horses used for dressage. The hypothesis was that the proposed training protocol would improve fitness and ensure the welfare of the animals by reducing stress predictors. Nine 4-year-old horses were evaluated before (M1) and six weeks after (M2) beginning a training protocol. The training program was performed six times per week and included 40−80 min of individually intensity-adjusted preparatory exercises for dressage. For both moments, the horses were examined before (T0) and after (T1) dressage simulation tests (DST), and at 30 (T2) and 240 min (T3) during the recovery period. Blood samples were taken to determine the horses' cortisol levels, total WBC, and neutrophil and lymphocyte counts. All variables were analyzed by one-way ANOVA and Tukey tests, with p ≤ 0.05. After training, there was a significant reduction in cortisol (p = 0.0133), HR (p = 0.0283), total WBC (p < 0.0001), and neutrophil (p < 0.0001) and lymphocyte (p = 0.0341) counts. Other findings included an increase in HRV parameters related to a cardiac vagal modulation. In conclusion, the chosen training protocol led to better fitness as the horses worked more intensively with lower cardiovascular requirements, and they showed blunted cortisol responses at M2. Such data can be used to evaluate performance, but also to predict the welfare of athletic horses.

7.
Vet Rec ; 187(5): 189, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32444507

RESUMO

INTRODUCTION: Respiratory diseases account for the highest number of clinical problems in horses compared with other body systems. While microbiological culture and sensitivity testing is essential for certain cases, knowledge of the most likely bacterial agents and their susceptibilities is necessary to inform empirical antibiotic choices. METHODS: A retrospective study of microbiological and cytological results from upper and lower respiratory samples (n=615) processed in a commercial laboratory between 2002 and 2012 was carried out. A further study of lower respiratory samples from horses with clinical signs of lower respiratory disease from May to June 2012 was undertaken. RESULTS: Both studies revealed Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa, Pasteurella species, Escherichia coli and Bordetella bronchiseptica as the most frequently isolated species. S equi subspecies zooepidemicus and subspecies equi were susceptible to ceftiofur (100 per cent) and erythromycin (99 per cent). Resistance to penicillin (12.5 per cent of S equi subspecies equi from upper respiratory tract samples) and tetracycline (62.7 per cent) was also detected. Gram-negative isolates showed resistance to gentamicin, trimethoprim-sulfamethoxazole and tetracycline but susceptibility to enrofloxacin (except Pseudomonas species, where 46.2 per cent were resistant). Multiple drug resistance was detected in 1 per cent of isolates. CONCLUSION: Resistance to first-choice antibiotics in common equine respiratory tract bacteria was noted and warrants continued monitoring of their susceptibility profiles. This can provide information to clinicians about the best empirical antimicrobial choices against certain pathogenic bacteria and help guide antibiotic stewardship efforts to converse their efficacy.


Assuntos
Farmacorresistência Bacteriana , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/microbiologia , Doenças Respiratórias/veterinária , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Feminino , Cavalos , Masculino , Doenças Respiratórias/tratamento farmacológico , Doenças Respiratórias/microbiologia , Estudos Retrospectivos , Reino Unido
8.
Sci Rep ; 10(1): 5325, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210337

RESUMO

Ocean acidification and warming (OA-W) result mainly from the absorption of carbon dioxide and heat by the oceans, altering its physical and chemical properties and affecting carbonate secretion by marine calcifiers such as gastropods. These processes are ongoing, and the projections of their aggravation are not encouraging. This work assesses the concomitant effect of the predicted pH decrease and temperature rise on early life stages of the neogastropod Tritia reticulata (L.), a common scavenger of high ecological importance on coastal ecosystems of the NE Atlantic. Veligers were exposed for 14 days to 12 OA-W experimental scenarios generated by a factorial design of three pH levels (targeting 8.1, 7.8 and 7.5) at four temperatures (16, 18, 20 and 22 °C). Results reveal effects of both pH and temperature (T °C) on larval development, growth, shell integrity and survival, individually or interactively at different exposure times. All endpoints were initially driven by pH, with impaired development and high mortalities being recorded in the first week, constrained by the most acidic scenarios (pHtarget 7.5). Development was also significantly driven by T °C, and its acceleration with warming was observed for the remaining exposure time. Still, by the end of this 2-weeks trial, larval performance and survival were highly affected by the interaction between pH and T °C: growth under warming was evident but only for T °C ≤ 20 °C and carbonate saturation (pHtarget ≥ 7.8). In fact, carbonate undersaturation rendered critical larval mortality (100%) at 22 °C, and the occurrence of extremely vulnerable, unshelled specimens in all other tested temperatures. As recruitment cohorts are the foundation for future populations, our results point towards the extreme vulnerability of this species in case tested scenarios become effective that, according to the IPCC, are projected for the northern hemisphere, where this species is ubiquitous, by the end of the century. Increased veliger mortality associated with reduced growth rates, shell dissolution and loss under OA-W projected scenarios will reduce larval performance, jeopardizing T. reticulata subsistence.


Assuntos
Água do Mar/química , Caramujos/crescimento & desenvolvimento , Ácidos , Animais , Oceano Atlântico , Dióxido de Carbono , Carbonatos , Mudança Climática , Ecossistema , Gastrópodes/crescimento & desenvolvimento , Aquecimento Global , Temperatura Alta , Concentração de Íons de Hidrogênio , Larva/crescimento & desenvolvimento , Oceanos e Mares , Temperatura
9.
ACS Appl Mater Interfaces ; 11(9): 8969-8981, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30693751

RESUMO

Inorganic-polymer composites have become promising materials to be processed by printing technologies because of their unique properties that allow the fabrication of flexible wearable electronics at reduced manufacturing costs. In the present work, a complete methodological process of assembling a flexible microthermoelectric generator based on inorganic-polymer materials is presented. The used microparticles were prepared by a top-down approach beginning with a previously prepared material by solid-state reaction and later scaled down through the use of ball milling. It was found that the necessity to proceed with a chemical treatment with HCl to reduce Bi2O3 present on the surface of the microparticle leads to a power factor (PF) of 2.29 µW K-2 m-1, which is two times higher than that of the untreated sample. On the fabrication of flexible inorganic-organic thermoelectric thick films based on Bi2Te3 microparticles (<50 µm) and the poly(vinyl alcohol) (PVA) polymer with different thicknesses ranging from 11 to 265 µm and with different Bi2Te3 weight percentages (wt %), we found that PVA allowed achieving a homogeneous dispersion of the parent inorganic thermoelectric materials, while still maintaining their high performance. The best produced ink was obtained with 25 wt % of PVA and 75 wt % of chemically treated Bi2Te3 micropowder with a Seebeck coefficient of -166 µV K-1 and a PF of 0.04 µW K-2 m-1. For this optimized concentration, a flexible thermoelectric device was fabricated using n-type thermoelectric inks, which constitutes a major advantage to be applied in printing techniques because of their low curing temperature. The device architecture was composed of 10 stripes with 0.2 × 2.5 cm2 each in a one-leg configuration. This prototype yielded a power output up to ∼9 µW cm-2 with a 46 K temperature gradient (Δ T), and the results were combined with numerical simulations showing a good match between the experimental and the numerical results. The thermoelectric devices studied in this work offer easy fabrication, flexibility, and an attractive thermoelectric output for specific power requirements such as for environmental health monitoring.

10.
J Colloid Interface Sci ; 504: 790-799, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28623704

RESUMO

An electrochromic nanocomposite based on a nickel-salen polymeric film - poly[Ni(3-Mesalen)], Mesalen=N,N'-bis(3-methylsalicylideneiminate) - and graphene nanoplatelets (GFNPs) with enhanced electrochromic stability was successfully prepared by anodic electropolymerization. Although the electrochemical processes typical of the polymer film were not changed by the presence of graphene, higher electroactive surface coverages could be obtained for nanocomposite films, which suggest the incorporation of GFNPs into the polymeric network. The nanocomposite showed multi-electrochromic behavior, with color changes between yellow (reduced state) and green (oxidized state). The inclusion of GFNPs into the poly[Ni(3-Mesalen)] structure accelerates the switching process, with the response time for green coloration decreasing by 50.7% and for yellow coloration by 60.0%, for films prepared with 30 electropolymerization cycles. In terms of electrochemical stability, after 10,000 electrochemical cycles the loss of charge was 7% for the graphene nanocomposite. The nanocomposite film was used as electrochromic material to assemble a flexible solid-state electrochromic device (ECD), which exhibited an outstanding electrochemical stability - only 3% of charge loss after 15days of continuous activity.

11.
ACS Appl Mater Interfaces ; 8(22): 14231-43, 2016 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-27175794

RESUMO

We report the application of two poly[Ni(salen)]-type electroactive polymer films as new electrochromic materials. The two films, poly[Ni(3-Mesalen)] (poly[1]) and poly[Ni(3-MesaltMe)] (poly[2]), were successfully electrodeposited onto ITO/PET flexible substrates, and their voltammetric characterization revealed that poly[1] showed similar redox profiles in LiClO4/CH3CN and LiClO4/propylene carbonate (PC), while poly[2] showed solvent-dependent electrochemical responses. Both films showed multielectrochromic behavior, exhibiting yellow, green, and russet colors according to their oxidation state, and promising electrochromic properties with high electrochemical stability in LiClO4/PC supporting electrolyte. In particular, poly[1] exhibited a very good electrochemical stability, changing color between yellow and green (λ = 750 nm) during 9000 redox cycles, with a charge loss of 34.3%, an optical contrast of ΔT = 26.2%, and an optical density of ΔOD = 0.49, with a coloration efficiency of η = 75.55 cm(2) C(-1). On the other hand, poly[2] showed good optical contrast for the color change from green to russet (ΔT = 58.5%), although with moderate electrochemical stability. Finally, poly[1] was used to fabricate a solid-state electrochromic device using lateral configuration with two figures of merit: a simple shape (typology 1) and a butterfly shape (typology 2); typology 1 showed the best performance with optical contrast ΔT = 88.7% (at λ = 750 nm), coloration efficiency η = 130.4 cm(2) C(-1), and charge loss of 37.0% upon 3000 redox cycles.

12.
Int J Infect Dis ; 32: 76-80, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25809760

RESUMO

Tuberculosis still remains a global health emergency, claiming 1.5 million lives in 2013. The bacterium responsible for this disease, Mycobacterium tuberculosis (M.tb), has successfully survived within hostile host environments, adapting to immune defence mechanisms, for centuries. This has resulted in a disease that is challenging to treat, requiring lengthy chemotherapy with multi-drug regimens. One explanation for this difficulty in eliminating M.tb bacilli in vivo is the disparate action of antimicrobials on heterogeneous populations of M.tb, where mycobacterial physiological state may influence drug efficacy. In order to develop improved drug combinations that effectively target diverse mycobacterial phenotypes, it is important to understand how such subpopulations of M.tb are formed during human infection. We review here the in vitro and in vivo systems used to model M.tb subpopulations that may persist during drug therapy, and offer aspirations for future research in this field.


Assuntos
Antituberculosos/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Animais , Humanos , Modelos Biológicos , Tuberculose/microbiologia
13.
Curr Cancer Drug Targets ; 15(4): 272-81, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25731686

RESUMO

Breast cancer is the most common malignancy in women worldwide and the second leading cause of cancer deaths after lung cancer. As in other malignancies, aneuploidy is a common feature of breast cancer and influences its behavior. Aneuploidy has been linked to inappropriate activity of the spindle assembly checkpoint (SAC), a surveillance mechanism that, in normal cells, prevents anaphase onset until correct alignment of all chromosomes at the metaphase is achieved. Interestingly, the widely used anti-microtubule drugs, vinca alkaloids and taxanes, kill cancer cells through chronic arrest in mitosis as a consequence of chronic SAC activation. Deregulated SAC has been reported in breast cancer in many reports and presents an attractive therapeutic strategy. We present here a review of the current knowledge on the SAC defects and the underlying molecular mechanisms in breast cancer, and discuss the potential of SAC components as targets for breast cancer therapies.


Assuntos
Antimitóticos/farmacologia , Neoplasias da Mama , Proteínas de Ciclo Celular/genética , Pontos de Checagem da Fase M do Ciclo Celular , Mitose/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Aneuploidia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase M do Ciclo Celular/genética
15.
Biomed Res Int ; 2014: 145289, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24995269

RESUMO

Abnormal chromosome number, or aneuploidy, is a common feature of human solid tumors, including oral cancer. Deregulated spindle assembly checkpoint (SAC) is thought as one of the mechanisms that drive aneuploidy. In normal cells, SAC prevents anaphase onset until all chromosomes are correctly aligned at the metaphase plate thereby ensuring genomic stability. Significantly, the activity of this checkpoint is compromised in many cancers. While mutations are rather rare, many tumors show altered expression levels of SAC components. Genomic alterations such as aneuploidy indicate a high risk of oral cancer and cancer-related mortality, and the molecular basis of these alterations is largely unknown. Yet, our knowledge on the status of SAC components in oral cancer remains sparse. In this review, we address the state of our knowledge regarding the SAC defects and the underlying molecular mechanisms in oral cancer, and discuss their therapeutic relevance, focusing our analysis on the core components of SAC and its target Cdc20.


Assuntos
Proteínas Cdc20/genética , Pontos de Checagem da Fase M do Ciclo Celular/genética , Neoplasias Bucais/genética , Aneuploidia , Proteínas Cdc20/metabolismo , Proteínas de Ciclo Celular/genética , Instabilidade Genômica , Humanos , Neoplasias Bucais/patologia , Oócitos/patologia
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