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1.
J Hosp Infect ; 127: 7-14, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35594987

RESUMO

BACKGROUND: The prevention of healthcare-associated infections requires continuous effort. In order to achieve better practical results, the control of environmental microbial biofilms with effective disinfection strategies should be addressed. AIM: To test the efficacy of different time cycles of nebulized hydrogen peroxide (H2O2) against bacterial and yeast dry biofilms. METHODS: The efficacies of a standard cycle (SC) and a fast cycle (FC) of nebulized H2O2 were compared. Microbial biofilms were grown on different material coupons. The metabolic activity of biofilms was determined by XTT assay, and the total biomass of biofilms was determined by crystal violet assay. FINDINGS: Regarding the efficacy of nebulized H2O2 against biofilms, the mean reduction in metabolic activity for the SC was 55.2% [standard deviation (SD) 19.4%], compared with 50.4% (SD 17.7%) for the FC. The mean reduction in total biomass for the SC was 45.5% (SD 22.7%), compared with 46.7% (SD 21.7%) for the FC. No significant differences were found between the tested cycles and materials. CONCLUSION: H2O2 nebulization was found to exhibit good efficacy against healthcare-associated microbial dry biofilms. Moreover, similar efficacies were found between the SC and the FC.


Assuntos
Infecção Hospitalar , Peróxido de Hidrogênio , Biofilmes , Desinfecção/métodos , Humanos , Peróxido de Hidrogênio/farmacologia , Saccharomyces cerevisiae
2.
Animal ; 14(9): 1987-1998, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32290896

RESUMO

Chitosan (CHI) is a natural biopolymer with antimicrobial, anti-inflammatory, antioxidant and digestive modulatory effects, which can be used in the ruminant diet to replace antibiotics. The aim of this study was to evaluate the effects of CHI on lamb growth traits, nutrients digestibility, muscle and fatty deposition, meat fatty acid (FA) profile, meat quality traits and serum metabolome. Thirty 30-month-old male lambs, half Suffolk and half Dorper, with an average BW of 21.65 ± 0.86 kg, were fed in a feedlot system for a total of 70 days. The lambs were separated into two groups according to the diet: the control (CON) group which received the basal diet and the CHI group which received the basal diet with the addition of CHI as 2 g/kg of DM in the diet. Lambs supplemented with CHI had a greater (P < 0.05) final BW, DM intake, final body metabolic weight (P < 0.05) and lower residual feed intake than the CON group. Animals fed CHI had a greater (P < 0.05) starch digestibility at 14 and 28 days, average daily gain at 14, 42 and 56 days, greater feed efficiency at 28 days and feed conversation at 14 and 42 days in feedlot. Most of the carcass traits were not affected (P > 0.05) by the treatment; however, the CHI supplementation improved (P < 0.05) dressing and longissimus muscle area. The treatments had no effect (P > 0.05) on the meat colour and other quality measurements. Meat from the CHI-fed lambs had a greater concentration (P < 0.05) of oleic-cis-9 acid, linoleic acid, linolenic-trans-6 acid, arachidonic acid and eicosapentaenoic acid. According to the variable importance in projection score, the most important metabolites to differentiate between the CON and the CHI group were hippurate, acetate, hypoxanthine, arginine, malonate, creatine, choline, myo-inositol, 2-oxoglutarate, alanine, glycerol, carnosine, histidine, glutamate and 3-hydroxyisobutyrate. Similarly, fold change (FC) analysis highlighted succinate (FC = 1.53), arginine (FC = 1.51), hippurate (FC = 0.68), myo-inositol (FC = 1.48), hypoxanthine (FC = 1.45), acetate (FC = 0.73) and malonate (FC = 1.35) as metabolites significantly different between groups. In conclusion, the present data showed that CHI changes the muscle metabolism improving muscle mass deposition, the lamb's performance and carcass dressing. In addition, CHI led to an alteration in the FA metabolism, changes in the meat FA profile and improvements in meat quality.


Assuntos
Quitosana , Ração Animal/análise , Animais , Composição Corporal , Dieta/veterinária , Masculino , Carne , Ovinos , Carneiro Doméstico
3.
Reumatismo ; 71(2): 75-80, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31309777

RESUMO

The objective was to determine the reduction of tophi in patients undergoing drug therapy in correlation with urate serum levels through ultrasound examination. A total of 31 male patients, between the ages of 33 to 77 years, with tophaceous gout were evaluated between 2005 and 2009, 11 of which were selected. Ultrasound examinations of visible tophi and evaluations of serum uric acids levels were performed annually on each patient. There was a statistically significant difference between measurements 1, 2, 3 and measurement 4 and between measurements 4 and 5. A strong significant positive association was seen between variation of tophus size and the reduction of serum uric acid levels.


Assuntos
Gota/sangue , Gota/diagnóstico por imagem , Ácido Úrico/sangue , Adulto , Idoso , Correlação de Dados , Gota/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
4.
Sci Total Environ ; 678: 793-800, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31085495

RESUMO

In recent years, the Stockholm Convention has listed an additional set of persistent organic pollutants (POPs) for elimination or restricted use/release. Data on the occurrence of these contaminants in food is scarce. Validated analytical methodology was developed to investigate the occurrence of hexachlorobutadiene (HCBD), pentachlorobenzene (PCBz), hexachlorobenzene (HCB) pentachlorophenol (PCP) and polychlorinated naphthalenes (PCNs) in 120 retail foods and 19 total diet study samples. The foods covered the range of commonly consumed dietary items including dairy products, eggs (hen and other species), poultry, meat, fish, vegetables, etc. HCBD showed a low frequency of detection, whereas PCBz, HCB and PCNs occurred in most samples (ranges: <0.01 to 0.19 µg/kg; <0.01 to 3.16 µg/kg and 0.1 to 166 ng ΣPCNs/kg respectively). PCP (<0.01 to 1.9 µg/kg) was detected more frequently in meat products, offal and eggs. Fish, shellfish, eggs from all species, animal fats, meat, offal and meat products showed higher contamination levels, which is normal when investigating lipophilic POPs. These levels of occurrence are similar to more recently reported literature levels but perhaps lower, relative to historic data. This is not unexpected, given the restrictions/limitations on these chemicals within the UK and Western Europe. The estimated human exposure to population groups through dietary intake is correspondingly low and based on current toxicological knowledge, the levels in the examined samples do not suggest a cause for health concern. The data also provide a current baseline for HCBD, PCBz and PCP, and update existing data for PCN and HCB occurrence in foods.


Assuntos
Exposição Dietética/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Contaminação de Alimentos/análise , Animais , Reino Unido
5.
Sci Total Environ ; 667: 359-370, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30831370

RESUMO

The potential for contaminant uptake from recycled materials used in livestock farming, to animal tissues and organs, was investigated in three practical modular studies involving broiler chickens, laying chickens and pigs. Six types of commercially available recycled materials were used either as bedding material for chickens or as fertilizer for cropland that later housed outdoor reared pigs. The contaminants studied included regulated contaminants e.g. polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins) and polychlorinated biphenyls (PCBs), but related contaminants such as polybrominated diphenylethers (PBDEs), hexabrominated cyclododecane (HBCDD), polychlorinated naphthalenes (PCNs), polybrominated dioxins (PBDD/Fs) and perfluoroalkyl substances (PFAS) were also investigated. Contaminant occurrence in the recycled materials was verified prior to the studies and the relationship to tissue and egg concentrations in market ready animals was investigated using a weights of evidence approach. Contaminant uptake to animal tissues and eggs was observed in all the studies but the extent varied depending on the species and the recycled material. PCBs, PBDEs, PCDD/Fs, PCNs and PFAS showed the highest potential to transfer, with laying chickens showing the most pronounced effects. PBDD/Fs showed low concentrations in the recycled materials, making it difficult to evaluate potential transfer. Higher resulting occurrence levels in laying chickens relative to broilers suggests that period of contact with the materials may influence the extent of uptake in chickens. Bio-transfer factors (BTFs) estimated for PCDD/F and PCBs showed a greater magnitude for chicken muscle tissue relative to pigs with the highest values observed for PCBs in laying chickens. There were no significant differences between BTFs for the different chicken tissues which contrasted with the high BTF values for pigs liver relative to muscle. The study raises further questions which require investigation such as the effects of repeated or yearly application of recycled materials as fertilizers, and the batch homogeneity/consistency of available recycled materials.


Assuntos
Agricultura/métodos , Ração Animal/análise , Monitoramento Ambiental , Poluentes Ambientais/análise , Contaminação de Alimentos/análise , Animais , Dibenzofuranos Policlorados/análise , Gado , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Reciclagem
6.
Br J Oral Maxillofac Surg ; 57(3): 251-254, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30904203

RESUMO

Hyperplasia of the mandibular condyle is self-limiting, but can lead to facial asymmetry, malocclusion, pain, and dysfunction of the temporomandibular joint (TMJ). Bone scintigraphy, particularly with single photon emission computed tomography (SPECT), is effective in assessing relative condylar uptake, but we know of no standardised methods or values. Our aim, therefore was to validate the values currently used to measure relative condylar uptake in our population. Between December 2015 and June 2018 44 patients had skull SPECT (15 male and 29 female patients, whose ages ranged from 4-33 years). They were having bone scans (hydroxydiphosphonate (HDP) -99MTc, 740 MBq ev) for unrelated reasons and had no known abnormalities of the head, facial asymmetry, or symptoms of the TMJ. Two research workers measured the relative uptake between the condyles using the summed transaxial images. The Hospital Ethics Committee approved the investigation. The maximum difference in condylar uptake was 8.33% with research worker 1 and 8.77% with research worker 2, and the mean (SD) differences were 3.03 (0.17) % and 3.29 (0.18) %, respectively. Data were tested for normality, and the t test and one-way ANOVA were used to assess the significance of differences. None was found in total counts either between sexes or age groups, and there were none between the total counts measured by the two research workers. We conclude that our results are within the published ranges, and the variation in condylar uptake was less than 5% in 37/44 patients, and in none was it 9% or more. When the results indicate less than 10%, but there is a high clinical suspicion of active hyperplasia, surgeons should use their clinical judgement to decide whether condylar surgery is required.


Assuntos
Côndilo Mandibular , Adolescente , Adulto , Criança , Pré-Escolar , Assimetria Facial , Feminino , Humanos , Hiperplasia , Masculino , Medronato de Tecnécio Tc 99m , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Adulto Jovem
7.
Virology ; 525: 192-199, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30292963

RESUMO

Domestic dogs share habitats with human, a fact that makes them a potential source of zoonotic viruses. Moreover, knowledge regarding possible bloodborne pathogens is important due to the increasing application of blood transfusion in dogs. In the present study, we evaluated the serum virome of 520 dogs using throughput sequencing (HTS). The serum samples were pooled and sequenced using an Illumina MiSeq platform. Our unbiased method identified prevalent canine pathogens as canine protoparvovirus 1 (canine parvovirus 2), undersearched agents as canine bocaparvovirus 1 (minute virus of canines) and canine circovirus, circular viruses closely related to viruses recently found in human samples, and new parvovirus and anelloviruses. The dog virome described in the present work furthers the knowledge concerning the viral population in domestic animals. The present data includes information regarding viral agents that are potentially transmitted through blood transfusion among dogs.


Assuntos
Doenças do Cão/virologia , Viroses/veterinária , Vírus/isolamento & purificação , Animais , Brasil/epidemiologia , Doenças do Cão/sangue , Doenças do Cão/epidemiologia , Cães , Viroses/sangue , Viroses/epidemiologia , Viroses/virologia , Vírus/classificação
8.
Adv Colloid Interface Sci ; 260: 85-94, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30177215

RESUMO

Polyphenols are secondary metabolites found in all vascular plants and constitute a large group of at least 10,000 unique compounds. Particular attention is currently being paid to polyphenols attributed to their beneficial effects in the protection and prevention of several diseases. While their use in food, pharmaceutical and cosmetic industries is largely documented, several environmental conditions (e.g. light, temperature or oxygen) may affect the physicochemical stability of polyphenols, compromising their bioactivity in vivo. To overcome these limitations, the loading of polyphenols into nanoparticles has been proposed aiming at both increasing their bioavailability and reducing eventual side effects. Lipid nanoparticles offer several advantages, namely their biodegradability and low toxicity, with the additional capacity to modify the release profile of loaded drugs. This paper is a review of the recent advances of lipid nanocarriers commonly used for the encapsulation of polyphenols, highlighting their added value to increase bioavailability and bioactivity of this group of compounds as well as their application in several diseases.


Assuntos
Portadores de Fármacos/química , Lipídeos/química , Nanopartículas/química , Polifenóis/química , Animais , Emulsões/química , Humanos
9.
Environ Int ; 114: 219-230, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29522986

RESUMO

The occurrence of a range of regulated and emerging organic environmental contaminants was investigated in 182 samples of edible marine fish sampled mainly from UK marine regions, but extending northerly to the coast of Norway and south to the Algarve. These species (sprats, mackerel, turbot, halibut, herring, grey mullet, sea bass, grey mullet, sardines, etc.) are among those considered to be at the highest risk of contamination with regulated contaminants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins), and polychlorinated biphenyls (PCBs), but the occurrence of polybrominated diphenylethers (PBDEs) and polybrominated biphenyls (PBBs) was also investigated. Sub-sets of samples (50-75) were also analysed for emerging contaminants: polychlorinated naphthalenes (PCNs), polybrominated and mixed halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls (PBDD/Fs, PXDD/Fs and PXBs) and perfluoroalkyl substances (PFAS). Contaminant occurrence varied with species and location, but all measured contaminants were detected, with sprats, sea bass, sardines, mackerel, and herring showing higher tissue concentrations. The concentrations of the different contaminants in the various samples were mapped utilising the GPS coordinate data of the capture locations to visualise spatial distribution levels. In terms of catch location, fish sampled from the coasts of southern Britain, north-western France and the Irish Sea appeared to contain proportionately higher levels of some contaminants - e.g. samples from the Irish Sea tended to show higher PCN concentrations, whereas higher levels of PCBs were observed in some fish sampled off the coasts of northern France. Similarly, samples of mullet from the southeast coast of UK showed much higher concentrations of BDE-99 than the other regions. In terms of occurrence trends, PCDD/F and PCB concentrations show a modest decline over the last decade but where limited background data is available for emerging contaminants, there is no evidence of downward trends.


Assuntos
Dioxinas e Compostos Semelhantes a Dioxinas/análise , Peixes/fisiologia , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Oceanos e Mares , Reino Unido
10.
Colloids Surf B Biointerfaces ; 166: 24-28, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29529505

RESUMO

The clinical use of poorly water-soluble drugs has become a big challenge in pharmaceutical development due to the compromised bioavailability of the drugs in vivo. Nanocrystals have been proposed as a formulation strategy to improve the dissolution properties of these drugs. The benefits of using nanocrystals in drug delivery, when compared to other nanoparticles, are related to their production facilities, simple structure, and suitability for a variety of administration routes. High pressure homogenization (HPH) is the most promising production process, which can be employed at low or high temperatures. Ibuprofen nanocrystals with a mean size below 175 nm, and polydispersity below 0.18, have been produced by melt-emulsification, followed by HPH. Two nanocrystal formulations, differing on the surfactant composition, have been produced, their in vitro ibuprofen release tested in Franz diffusion cells and adjusted to several kinetic models (zero order, first order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, Baker-Lonsdale and Weibull model). Cell viability was assessed at 3, 6 and 24 h of incubation on human epithelial colorectal cells (Caco-2) by AlamarBlue® colorimetric assay. For both formulations, Caco-2 cells viability was dependent on the drug concentration and time of exposure.


Assuntos
Ibuprofeno/química , Nanopartículas/química , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Humanos , Ibuprofeno/farmacologia , Cinética
11.
Biomed Pharmacother ; 101: 137-144, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29482059

RESUMO

Silver nanoparticles (AgNPs) were prepared by GREEN chemistry relying on the reduction of AgNO3 by phytochemicals present in black tea extract. AgNPs were fully characterized by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy ((UV-vis)), X-ray diffraction (XRD) and energy dispersive absorption spectroscopy (EDS). The synthesized AgNPs induced a decrease of the cell viability in a dose-dependent manner with a low IC50 (0.5 ±â€¯0.1 µM) for an ovarian carcinoma cell line (A2780) compared to primary human fibroblasts (IC50 5.0 ±â€¯0.1 µM). The DNA binding capability of CT (calf thymus) DNA was investigated using electronic absorption and fluorescence spectroscopies, circular dichroism and viscosity titration methods. Additionally, the AgNPs strongly quench the intrinsic fluorescence of BSA, as determined by synchronous fluorescence spectra.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Química Verde/métodos , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/toxicidade , Prata/toxicidade , Animais , Bovinos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Células HCT116 , Humanos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Soroalbumina Bovina/metabolismo , Prata/metabolismo , Chá/metabolismo , Chá/toxicidade
13.
Int J Organ Transplant Med ; 8(2): 104-109, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28828170

RESUMO

BACKGROUND: Natural history of HCV-infected renal transplant recipients is about to change with the invention of new drugs available for the treatment of HCV. OBJECTIVE: To analyze the evolution of renal transplant recipients infected with HCV in 30 years of activity of a Renal Transplantation Unit. METHODS: We studied 1334 patients who underwent renal transplantation between 1985 and 2015. RESULTS: 189 (14.2%) of these 1334 were found HCV seropositive. 60 were HCV RNA-positive for >6 months. 5 died with a functioning graft; 19 lost their graft and resumed dialysis. Most of the rejections occurred within the first year of the transplantation and none resulted in immediate loss of the graft. In post-transplantation period, 14 patients developed clinical hepatic disease, 10 manifested new-onset diabetes after transplantation, and 4 had de novo neoplasia, none of them had hepatocellular carcinoma. The outcomes of the different variables analyzed were similar between patients with HCV-infection and those with HCV and HBV co-infection. The median survival time was 13.4 (95% CI: 10.7-16.1) years; the median survival time of patients without HCV infection was 14.6 (95% CI: 13.8-15.4) years (p=0.23). CONCLUSION: In the era before the availability of new anti-HCV drugs, our experience with HCV-infected renal transplant recipients revealed similar post-transplantation complications, graft and patient survival as those not infected with HCV.

14.
Haemophilia ; 23(5): 660-672, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28574216

RESUMO

The purpose of this review was to summarize the current knowledge on the utilization of magnetic resonance imaging (MRI) and ultrasound (US) for assessing arthropathy in children and adolescents with haemophilia and to recognize the limitations of each imaging modality and pitfalls in the diagnosis of soft tissue and osteochondral abnormalities. Awareness of MRI and US limitations and pitfalls in the assessment of joints in persons with haemophilia is essential for accurate diagnosis and optimal management of haemophilic arthropathy.


Assuntos
Hemartrose/diagnóstico por imagem , Hemartrose/etiologia , Hemofilia A/complicações , Hemofilia B/complicações , Hemartrose/patologia , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Ultrassonografia/normas
16.
Vet Comp Oncol ; 15(4): 1537-1542, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28150469

RESUMO

BACKGROUND: Despite continuous efforts, the treatment of canine cancer has still to deliver effective strategies. For example, traditional chemotherapy with doxorubicin and/or docetaxel does not significantly increase survival in dogs with canine mammary tumors (CMTs). AIMS: Evaluate the efficiency of two metal compounds [Zn(DION)2 ]Cl (TS262, DION = 1,10-phenanthroline-5,6-dione) and [CoCl(H2 O)(DION)2 ][BF4 ] (TS265) and novel nanovectorizations designed to improve the anti-cancer efficacy of these compounds in a new CMT derived cell line (FR37-CMT). MATERIALS AND METHODS: FR37-CMT cells were exposed to different concentrations of TS262 and TS265 and two new nanoparticle systems and cellular viability was determined. These nanosystems are composed of polyethylene-glycol, bovine-serum-albumin and TS262 or TS265 (NanoTS262 or NanoTS265, respectively). RESULTS: In FR37-CMT, TS262 and TS265 displayed IC50 values well below those displayed by doxorubicin and cisplatin. The nanovectorizations further decreased the IC50 values. DISCUSSION: TS262 and TS265 proved to be effective against FR37-CMT cells and more effective than of doxorubicin and cisplatin. The Nanosystems efficiently delivered the cytotoxic cargo inducing a significant reduction of cell viability in FR37-CMT cell line when compared to the free compounds. CONCLUSIONS: TS262 and TS265 are compounds with potential in the treatment of CMTs. NanoTS262 and NanoTS265 demonstrate that such simple nanovectorization via gold nanoparticles shows tremendous potential as anti-cancer formulations, which may easily be expanded to suit other cargo.


Assuntos
Antineoplásicos/uso terapêutico , Cobalto/uso terapêutico , Doenças do Cão/tratamento farmacológico , Ouro/uso terapêutico , Neoplasias Mamárias Animais/tratamento farmacológico , Nanopartículas Metálicas/uso terapêutico , Compostos de Zinco/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Cobalto/administração & dosagem , Cães , Feminino
17.
Saudi Pharm J ; 25(1): 99-103, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28223869

RESUMO

Paracetamol (PAR), phenylephrine hydrochloride (PHE) and chlorpheniramine maleate (CPM) are commonly used in clinical practice as antipyretic and analgesic drugs to ameliorate pain and fever in cold and flu conditions. The present work describes the use of thermal analysis for the characterization of the physicochemical compatibility between drugs and excipients during the development of solid dosage forms. Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) were used to study the thermal stability of the drug and of the physical mixture (drug/excipients) in solid binary mixtures (1:1). DSC thermograms demonstrated reproducible melting event of the prepared physical mixture. Starch, mannitol, lactose and magnesium stearate influence thermal parameters. Information recorded from the derivative thermogravimetric (DTG) and TGA curves demonstrated the decomposition of drugs in well-defined thermal events, translating the suitability of these techniques for the characterization of the drug/excipients interactions.

18.
Saudi Pharm J ; 25(8): 1117-1124, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166898

RESUMO

The reduction of the particle size of drugs of pharmaceutical interest down to the nano-sized range has dramatically changed their physicochemical properties. The greatest disadvantage of nanocrystals is their inherent instability, due to the risk of crystal growth. Thus, the selection of an appropriate stabilizer is crucial to obtain long-term physicochemically stable nanocrystals. High pressure homogenization has enormous advantages, including the possibility of scaling up, lack of organic solvents and the production of small particles diameter with low polydispersity index. The sequential use of high shear homogenization followed by high pressure homogenization, can modulate nanoparticles' size for different administration routes. The present study focuses on the optimization of the production process of two formulations composed of different surfactants produced by High Shear Homogenization followed by hot High Pressure Homogenization. To build up the surface response charts, a 22 full factorial design experiment, based on 2 independent variables, was used to develop optimized formulations. The effects of the production process on the mean particle size and polydispersity index were evaluated. The best ibuprofen nanocrystal formulations were obtained using 0.20% Tween 80 and 1.20% PVP K30 (F1) and 0.20% Tween 80 and 1.20% Span 80 (F2). The estimation of the long-term stability of the aqueous suspensions of ibuprofen nanocrystals was studied using the LUMISizer. The calculated instability index suggests that F1 was more stable when stored at 4 °C and 22 °C, whereas F2 was shown to be more stable when freshly prepared.

19.
Vet Comp Oncol ; 15(3): 952-967, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27140424

RESUMO

Here we describe the establishment of a new canine mammary tumour (CMT) cell line, FR37-CMT that does not show dependence on female hormonal signaling to induce tumour xenografts in NOD-SCID mice. FR37-CMT cell line has a stellate or fusiform shape, displays the ability to reorganize the collagen matrix, expresses vimentin, CD44 and shows the loss of E-cadherin which is considered a fundamental event in epithelial to mesenchymal transition (EMT). The up-regulation of ZEB1, the detection of phosphorylated ERK1/2 and the downregulation of DICER1 and miR-200c are also in accordance with the mesenchymal characteristics of FR37-CMT cell line. FR37-CMT shows a higher resistance to cisplatin (IC50 >50 µM) and to doxorubicin (IC50 >5.3 µM) compared with other CMT cell lines. These results support the use of FR37-CMT as a new CMT model that may assist the understanding of the molecular mechanisms underlying EMT, CMT drug resistance, fostering the development of novel therapies targeting CMT.


Assuntos
Doenças do Cão/patologia , Neoplasias Mamárias Animais/patologia , Animais , Linhagem Celular Tumoral , Colágeno/metabolismo , Cães , Feminino , Receptores de Hialuronatos/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Vimentina/metabolismo
20.
Dalton Trans ; 45(47): 19127-19140, 2016 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-27868117

RESUMO

The limitations of platinum complexes in cancer treatment have motivated the extensive investigation into other metal complexes such as ruthenium. We herein present the synthesis and characterization of a new family of ruthenium compounds 1a-5a with the general formula [Ru(bipy)2L][CF3SO3]2 (bipy = 2,2'-bipyridine; L = bidentate ligand: N,N; N,P; P,P; P,As) which have been characterized by elemental analysis, ES-MS, 1H and 31P-{1H} NMR, FTIR and conductivity measurements. The molecular structures of four Ru(ii) complexes were determined by single crystal X-ray diffraction. All compounds displayed moderate cytotoxic activity in vitro against human A2780 ovarian, MCF7 breast and HCT116 colorectal tumor cells. Compound 5a was the most cytotoxic compound against A2780 and MCF7 tumor cells with an IC50 of 4.75 ± 2.82 µM and 20.02 ± 1.46 µM, respectively. The compounds showed no cytotoxic effect on normal human primary fibroblasts but rather considerable selectivity for A2780, MCF7 and HCT116 tumor cells. All compounds induce apoptosis and autophagy in A2780 ovarian carcinoma cells and some nuclear DNA fragmentation. All compounds interact with CT-DNA with intrinsic binding constants in the order 1a > 4a > 2a > 3a > 5a. The observed hyperchromic effect may be due to the electrostatic interaction between positively charged cations and the negatively charged phosphate backbone at the periphery of the double helix-CT-DNA. Interestingly, compound 1a shows a concentration dependent DNA double strand cleavage. In addition in vivo toxicity has been evaluated on zebrafish embryos unveiling the differential toxicity between the compounds, with LC50 ranging from 8.67 mg L-1 for compound 1a to 170.30 mg L-1 for compound 2a.


Assuntos
2,2'-Dipiridil , Antineoplásicos , Complexos de Coordenação , Rutênio , 2,2'-Dipiridil/química , 2,2'-Dipiridil/farmacologia , 2,2'-Dipiridil/toxicidade , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/toxicidade , DNA/química , Fragmentação do DNA , Embrião não Mamífero/efeitos dos fármacos , Humanos , Dose Letal Mediana , Estrutura Molecular , Rutênio/química , Rutênio/farmacologia , Rutênio/toxicidade , Peixe-Zebra
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