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1.
Eur J Prosthodont Restor Dent ; 31(4): 398-406, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37382338

RESUMO

INTRODUCTION: Adjustments with diamond burs on the ceramic surface can affect its roughness and decrease flexural strength. This study evaluated the effect of polishing or glazing on the surface roughness and biaxial flexural strength of a zirconia-reinforced lithium silicate glass-ceramic upon adjustment with diamond burs. METHODS: Seventy disks were prepared according to ISO 6872 and divided into seven groups (n = 10) according to different adjustments and finishing processes. Surface roughness was measured prior to biaxial flexural strength testing. The topography was analyzed using an atomic force microscope , fracture markings were identified using a stereomicroscope and representative specimens were analyzed using scanning electron microscopy. RESULTS: The use of diamond burs significantly increased the surface roughness and decreased the strength of the evaluated ceramic (p⟨0.05). Polishing reduced the ceramic's roughness but resulted in flexural strength similar to that of the groups with wear (p⟩0.05). The glaze-treated specimens showed flexural strength statistically similar to the control group (p>0.05) but higher roughness, similar to those with wear. CONCLUSIONS: Polishing reduced the surface roughness but did not affect the biaxial flexural strength of the ZLS ceramic. At the same time, the application of glaze after wear increased the strength.


Assuntos
Cerâmica , Polimento Dentário , Teste de Materiais , Propriedades de Superfície , Polimento Dentário/métodos , Zircônio , Diamante , Porcelana Dentária
2.
Palliat Support Care ; 20(4): 496-504, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34581266

RESUMO

INTRODUCTION: There is a growing interest in the emotional state of cancer patients. The main objective of this pilot study is to assess the feasibility, acceptability, and preliminary efficacy of Meaning-Centered Psychotherapy and Essential Care (MCP-EC) in patients with advanced cancer compared with usual psychological support. We define "Essential Care" as the promotion of patient care and self-care through the recall of good care experiences and discussion of the concepts: responsibility, self-compassion, kindness, and attitude. METHOD: Pilot, single-center, and prospective study of 30 patients with advanced cancer and emotional distress. Our adaptation consisted in three session Meaning-Centered Psychotherapy-Palliative Care, plus a fourth session named "Essential Care". The study was carried out in two phases. First, 20 patients were randomized to one of the two arms: individual MCP-EC (experimental, n = 10) or usual psychological supportive (control, n = 10). In a second phase, 10 patients were assigned consecutively to Group MCP-EC (n = 10). All patients were evaluated at baseline (pre-) and post-intervention with questionnaires for sociodemographic data and clinical scales. RESULTS: Nineteen patients completed the 4 sessions of MCP-EC, 9 individual format and 10 group format. Usual supportive intervention was delivered to 10 control patients. Total 28 patients completed pre- and post-treatment evaluations. There were no pre- vs. post-differences in the evaluations of the control group. In the experimental group, significant pre- vs. post-differences were found in EQ-5D-3L, HADS, FACIT, DM, HAI, SCS-SF, and TD questionnaires. These results indicated that MCP-EC reduced anxiety and depression symptoms, hopelessness, demoralization, as well as increased spiritual well-being and sense of meaning. Participants were satisfied and found the MCP-EC intervention positively. CONCLUSIONS: This pilot study suggests that the MCP-EC has feasibility, acceptability, and preliminary efficacy reducing the emotional distress in advanced cancer patients. Larger studies are warranted to clarify the strengths and limitations of this psychotherapy.


Assuntos
Neoplasias , Psicoterapia de Grupo , Humanos , Neoplasias/complicações , Neoplasias/psicologia , Neoplasias/terapia , Cuidados Paliativos/métodos , Projetos Piloto , Estudos Prospectivos , Psicoterapia/métodos , Psicoterapia de Grupo/métodos
3.
Clin Radiol ; 76(12): 941.e1-941.e10, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34579865

RESUMO

The cervical spine is part of the axial skeleton and is responsible for protecting vital structures, such as the spinal cord and the vertebral arteries and veins. Traumatic injury to the cervical spine occurs in approximately 3% of blunt trauma injuries, and approximately 80% are below the level of C2. The AO Spine society divides the spine into four segments: the upper cervical spine (C0-C2), subaxial spine (C3-C7), thoracolumbar spine, and sacral spine. Various classifications have been proposed for the subaxial segment since that of Allen and Ferguson in 1982; however, none is universally accepted, and treatment remains controversial. The complex anatomy and biomechanics of the subaxial spine and the lack of a widely accepted classification system make these injuries difficult to evaluate on imaging. The Subaxial Injury Classification System (SLIC) uses fracture morphology, the integrity of discoligamentous complex, and neurological status to score the patient and determine between operative and non-operative management; however, other factors may influence management, such as time for immobilisation, osteoporosis, surgeon's experience, and hospital circumstances. SLIC classifies fracture morphology in a crescent order of severity based on Allen and Ferguson's classification. Compression fractures are the simpler ones, while both distraction injuries and translation/rotation are severe injuries, which are always associated with some degree of discoligamentous complex (DLC) injury. This article will review the indications for imaging, the basis of the SLIC classification, the different types of fracture morphology, evaluation of the DLC, and other features important in decision making in subaxial spine trauma.


Assuntos
Vértebras Cervicais/lesões , Traumatismos da Coluna Vertebral/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Traumatismos da Coluna Vertebral/classificação , Traumatismos da Coluna Vertebral/etiologia , Tomografia Computadorizada por Raios X
4.
Int Endod J ; 54(8): 1342-1352, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33724486

RESUMO

AIM: To establish an experimental model combining chronic stress and apical periodontitis by assessing the development of periapical lesions in rats in three different time points. METHODOLOGY: Forty-eight male Wistar rats were randomly assigned into two equal groups: Apical periodontitis (AP) and AP + Stress (AP + S). The animals of the AP group were not exposed to stressful conditions whereas the AP + S group were exposed to a variety of stressors on a daily basis until the end of the experiment. After three weeks of chronic unpredictable stress, apical periodontitis was induced in both groups by exposing the pulpal tissue of the mandibular first molar to the oral environment. Each group was further subdivided into three subgroups according to the euthanasia period: 14, 21 and 28 days after pulp exposure. The animals were weighed, and the blood was collected for corticosterone serum dosage by radioimmunoassay. The mandibles were removed and submitted to histopathological and microtomography analyses to assess the inflammatory response and the progression of periapical lesions. Comparisons between the AP and AP + S groups were performed using Student's t-test and Mann-Whitney U-test for parametric and nonparametric data, respectively. The one-way anova test followed by Tukey's test (parametric data) and Kruskal-Wallis followed by Dunn's test (nonparametric data) were used for comparisons between the three time points within the same group (P < 0.05). RESULTS: The AP + S group had a significantly lower average percentage of weight gain at 14 days and 21 days after AP induction (P < 0.05). Significantly higher levels of corticosterone were found in the AP + S group at 21 days (P < 0.05). The AP + S group had a significantly greater intensity and extension of inflammatory infiltrate with larger areas of bone loss compared to the AP groups at 21 days (P < 0.05). The volume of the periapical lesions in the AP + S group was significantly larger than that of the AP group 21 days following pulp exposure (P < 0.05). CONCLUSIONS: The chronic unpredictable stress model applied for 6 weeks exacerbated the inflammatory response and increased bone loss associated with AP, especially 21 days after its induction. This model appears to be suitable for investigating the bidirectional relationship between apical periodontitis and chronic stress.


Assuntos
Periodontite Periapical , Animais , Masculino , Periodontite Periapical/diagnóstico por imagem , Ratos , Ratos Wistar , Aumento de Peso
5.
Int Endod J ; 54(1): 61-73, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32896000

RESUMO

AIM: To investigate the presence of resolvins E1 (RvE1) and D2 (RvD2) in teeth with primary endodontic infections and apical periodontitis, and to assess the influence of calcium hydroxide medication [Ca(OH)2 ], in association with 2% chlorhexidine gel (2% CHX gel), and N-acetylcysteine (NAC) on the levels of RvE1 and RvD2 in periapical tissues. METHODOLOGY: Thirty-six single-rooted teeth with primary endodontic infections and apical periodontitis were selected and randomly divided into three groups according to the medication: [Ca(OH)2 ] + saline solution (SSL) [Ca(OH)2  + SSL group] (n = 12), Ca(OH)2  + 2% chlorhexidine gel [Ca(OH)2  + 2% CHX gel group] (n = 12) and NAC [NAC group] (n = 12). Samples were collected from the periapical interstitial fluid at two different sampling times: before (S1) and after 14 days of intracanal medications (S2). Resolvins were measured using the enzyme-linked immunosorbent assay. Data were analysed using paired t-test, Wilcoxon test and Kruskal-Wallis test, followed by Dunn's post hoc test; all statistical tests were performed at a significance level of 5%. RESULTS: RvE1 and RvD2 were detected in 100% of the samples (36/36) at S1 and S2. Ca(OH)2 medication did not increase the levels of RvE1 or RvD2 (both P > 0.05); however, NAC significantly increased the levels of RvE1 and RvD2 after 14 days of treatment (P < 0.05). CONCLUSIONS: RvE1 and RvD2 were detected in periapical tissues from teeth with root canal infections. Moreover, calcium hydroxide medication did not increase the levels of resolvins in apical periodontitis. In contrast, the use of NAC intracanal medication significantly increased the levels of RvE1 and RvD2 after 14 days of treatment.


Assuntos
Hidróxido de Cálcio , Periodontite Periapical , Acetilcisteína , Clorexidina , Cavidade Pulpar , Humanos , Periodontite Periapical/tratamento farmacológico , Irrigantes do Canal Radicular , Preparo de Canal Radicular
6.
J Clin Pediatr Dent ; 44(4): 228-233, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33167014

RESUMO

AIM: To assess the association between probable sleep bruxism (PSB) and other occlusal characteristics in children and teenagers with Cerebral Palsy (CP). STUDY DESIGN: A cross-sectional study was carried out with 148 participants (74 with CP and 74 without special needs) aged between 2 and 14 years old. Participants underwent an oral clinical examination to evaluate the occlusal characteristics. Parents/caregivers filled out a questionnaire with information related to the typical sounds of PSB, sociodemographic factors and the presence of harmful oral habits in the study participants. Data analysis was carried out, using Chi-square or Fisher's exact test and Odds Ratio (p<0.05). RESULTS: PSB and malocclusion (68.9% and 95.9%, respectively) were more prevalent in participants with CP than in participants without CP. The association between PSB and the presence of a wear facet was statistically significant (p < 0.001) in participants with CP. In this group, 64.8% of participants with PSB presented tooth wear. CONCLUSION: Presence of dental wear facets was significantly associated with PSB in individuals with cerebral palsy.


Assuntos
Paralisia Cerebral , Má Oclusão , Bruxismo do Sono , Adolescente , Paralisia Cerebral/complicações , Paralisia Cerebral/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Humanos , Fatores de Risco , Bruxismo do Sono/complicações , Bruxismo do Sono/epidemiologia
7.
Int Endod J ; 51(1): 41-57, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28439952

RESUMO

AIM: To establish an SV40 T-Ag-transfected cell line of human pulp-derived cells in order to compare the cytotoxicity, genotoxicity and to investigate the activities of immunological biomarkers of several endodontic sealers. METHODOLOGY: Primary human pulp cells and transfected cells were cultured. Cell morphology and proliferation were analysed, and the expression of cell-specific gene transcripts and proteins was detected by RT-PCR and immunohistochemistry. Transfection of human pulp-derived cells resulted in an immortalized cell line retaining phenotypic characteristics from the primarily cells tested. The SV40 T-Ag-transfected cells were cultured and stimulated by sealers (Apexit Plus, Real Seal, AH Plus, and EndoREZ) to evaluate the cytotoxicity and genotoxicity by MTT and MTN assays, respectively. Immunological inflammatory biomarkers (IL6, IL8 and TNF-α) were determined by ELISA assay. The differences between median values were statistically analysed using Kruskal-Wallis and Dunn's tests at 5% significance level. RESULTS: The cytotoxicity assay revealed that multimethacrylate (Real Seal) was the most cytotoxic sealer (P < 0.05) and exhibited the highest inflammatory potential against the SV40 T-Ag-transfected cells (P < 0.05). All root canal sealers tested were able to stimulate the immortalized pulp cells to produce IL-6, IL-8 and TNF-α, with differences in relation to the control group (P < 0.05). Higher levels of IL-6, IL-8 and TNF-α were found in cell supernatant after stimulation with multimethacrylate (Real Seal) compared to all other sealers tested (P < 0.05). No differences were found comparing epoxy resin-based sealer (AHPlus), single-methacrylate sealer (EndoREZ) and calcium hydroxide-based sealer (Apexit Plus), regardless of the cytokine investigated (all P > 0.05). CONCLUSIONS: A SV40 T-Ag-transfected cell line of human pulp-derived cells was established. The methacrylate resin-based sealer (Real Seal) exhibited the greatest cytoxicity and inflammatory potential against immortalized pulp cells compared to an epoxy resin-based sealer (AH Plus), a methacrylate-based sealer (EndoRez) and a calcium hydroxide-based sealer (Apexit).


Assuntos
Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/toxicidade , Biomarcadores/análise , Células Cultivadas , Citocinas/análise , Humanos , Teste de Materiais , Transfecção
8.
Photochem Photobiol Sci ; 15(5): 654-65, 2016 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-27101527

RESUMO

Beetle luciferases, the enzymes responsible for bioluminescence, are special cases of CoA-ligases which have acquired a novel oxygenase activity, offering elegant models to investigate the structural origin of novel catalytic functions in enzymes. What the original function of their ancestors was, and how the new oxygenase function emerged leading to bioluminescence remains unclear. To address these questions, we solved the crystal structure of a recently cloned Malpighian luciferase-like enzyme of unknown function from Zophobas morio mealworms, which displays weak luminescence with ATP and the xenobiotic firefly d-luciferin. The three dimensional structure of the N-terminal domain showed the expected general fold of CoA-ligases, with a unique carboxylic substrate binding pocket, permitting the binding and CoA-thioesterification activity with a broad range of carboxylic substrates, including short-, medium-chain and aromatic acids, indicating a generalist function consistent with a xenobiotic-ligase. The thioesterification activity with l-luciferin, but not with the d-enantiomer, confirms that the oxygenase activity emerged from a stereoselective impediment of the thioesterification reaction with the latter, favoring the alternative chemiluminescence oxidative reaction. The structure and site-directed mutagenesis support the involvement of the main-chain amide carbonyl of the invariant glycine G323 as the catalytic base for luciferin C4 proton abstraction during the oxygenase activity in this enzyme and in beetle luciferases (G343).


Assuntos
Besouros/química , Proteínas de Insetos/química , Luciferases/química , Oxigenases/química , Sequência de Aminoácidos , Animais , Coenzima A Ligases/química , Coenzima A Ligases/metabolismo , Besouros/enzimologia , Besouros/metabolismo , Cristalografia por Raios X , Esterificação , Proteínas de Insetos/metabolismo , Luciferases/metabolismo , Modelos Moleculares , Oxigenases/metabolismo , Conformação Proteica , Domínios Proteicos
9.
J Dairy Sci ; 99(11): 8831-8846, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27614839

RESUMO

The response of transition dairy cows to dietary supplementation with fat sources of various fatty acid profiles could affect hepatic fat metabolism differently. Twenty-eight Holstein cows were blocked for similar calving date 4wk before expected parturition to compare the effects of feeding sources of n-3 and n-6 fatty acids on milk production and composition, plasma metabolites, and liver parameters. Cows within each block were assigned to 1 of 3 isonitrogenous and isoenergetic diets: control with a source of calcium salts of palm oil (MEG; 1.1 and 2.6% of the dry matter in prepartum and postpartum diets, respectively); n-3 fatty acids supplied as whole flaxseed (WFL; 4.8 and 7.7% of the dry matter in prepartum and postpartum diets, respectively); and n-6 fatty acids supplied as whole linola (WLO; 4.8 and 7.7% of the dry matter in prepartum and postpartum diets, respectively). Diets were fed until wk 14 of lactation. Contrasts of WFL versus WLO and polyunsaturated fatty acids versus MEG were compared. Cows fed polyunsaturated fatty acids increased dry matter intake over time at a greater extent than those fed MEG, which resulted in enhanced energy balance. Cows fed MEG produced more milk compared with those fed polyunsaturated fatty acids, and there was no difference between those fed WFL and WLO. We found no effect on body condition score and body weight. Plasma concentrations of glucose, fatty acids, and BHB were similar among diets. There was no effect of diet on concentration of glycogen and activities of superoxide dismutase and glutathione peroxidase in the liver. We observed higher concentrations of hepatic lipids and triacylglycerol in cows fed MEG compared with those fed polyunsaturated fatty acids, and no difference between WFL and WLO. Hepatic catalase activity tended to be higher on wk 4 after calving for cows supplemented with WFL compared with those fed WLO. Feeding linoleic and linolenic acids as unprotected oilseeds increased dry matter intake over time at a greater extent for cows fed MEG, improved the energy status, and lowered hepatic lipids and triacylglycerol contents, which may contribute to enhance the health status of transition dairy cows.


Assuntos
Linho/metabolismo , Leite , Animais , Bovinos , Dieta/veterinária , Metabolismo Energético , Feminino , Lactação , Metabolismo dos Lipídeos
10.
Indian J Lepr ; 88(3): 137-46, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30207439

RESUMO

This study has been carried out to investigate the frequency of musculoskeletal symptoms in people affected by leprosy and correlate this to their functional capacity to perform daily living and working activities and to their degree of disability. This cross-sectional study was performed on 100 clients who answered a questionnaire on personal and clinical data, the Nordic Musculoskeletal (QNSO), and the shoulder, arm and hand dysfunction (DASH) questionnaires. The mean age was 53.63 years and there was a predominance of men (67%), low education (53%), and multibacillary disease (84%). Physical impairment affected 95% of respondents and 92% indicated pain and/or paresthesia in the arms that interfered in functional capacity.Respondents with musculoskeletal symptoms have more difficulty to perform daily living and working activities compared to those without musculoskeletal symptoms (p-value<0.05). The presence of physical disabilities was not associated with difficulties to perform daily living (p-value=0.29) and labor activities (p-value=0.87). The majority of patients experienced pain and/or paresthesia of the arms, and this was associated with difficulties to perform daily living and working activities. However, the presence of physical disability does not seem to cause major impediments or limitations to perform these activities.


Assuntos
Atividades Cotidianas , Avaliação da Deficiência , Pessoas com Deficiência , Hanseníase/complicações , Adulto , Idoso , Estudos Transversais , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Inquéritos e Questionários
11.
Clin Exp Allergy ; 45(9): 1459-71, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25944185

RESUMO

BACKGROUND: Allergic asthma is a chronic pulmonary disease characterized by a Th2 inflammatory response. The modulation of a Th2 immune response based on immune deviation to a Th1 pattern or induction and migration of regulatory T cells to the lungs constitutes one of the major therapeutic approaches that is being investigated for the treatment of allergic asthma. The potentials of Mycobacterium leprae 65-kD heat-shock protein or Toll-like receptor 9 ligand (CpG oligodeoxynucleotides) as immune modulators for the treatment of airway allergic disease have been studied individually. OBJECTIVE: Mycobacterial protein combined with CpG was used as immunotherapy for airway allergy. METHODS: Using an ovalbumin-induced asthma model, mice were sensitized and challenged, and then treated with mycobacterial heat-shock protein (Hsp65) combined with CpG. RESULTS: The treatment of mice with established allergy led to the attenuation of eosinophilia, Th2 cytokines and airway hyperresponsiveness. Hsp65 plus CpG treatment also induced an increase in OVA-specific IFN-γ levels and in the frequency of lung inflammatory monocytes. Moreover, we show that the reduction of eosinophilia and the recruitment of inflammatory monocytes to the lungs required early triggering of TLR9, IFN-γ and CCR2 by immunotherapy components. CONCLUSION: In addition to immune deviation to a Th1 response in the modulation of Th2 allergic inflammation, our findings also attribute an important role to the innate response mediated by TLR9, associated with the recruitment of CCR2-dependent monocytes. CLINICAL RELEVANCE: Our findings show that the Hsp65/CpG treatment is a promising strategy for consideration in translational studies.


Assuntos
Asma/tratamento farmacológico , Proteínas de Bactérias/farmacologia , Chaperonina 60/farmacologia , Interferon gama/imunologia , Mycobacterium leprae , Oligodesoxirribonucleotídeos/farmacologia , Receptores CCR2/imunologia , Transdução de Sinais/efeitos dos fármacos , Receptor Toll-Like 9/imunologia , Animais , Asma/genética , Asma/imunologia , Imunoterapia , Interferon gama/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Receptores CCR2/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/patologia , Receptor Toll-Like 9/genética
12.
Genet Mol Res ; 14(1): 464-73, 2015 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-25729980

RESUMO

The Malpighian tubules play a key role in insect osmoregulation. Although a transcriptional analysis has been done for the Malpighian tubules in Drosophila melanogaster (Diptera), no functional genomics analysis has yet been carried out for any Coleoptera species. Recently, we constructed a cDNA library from Malpighian tubules of larval Zophobas morio, a close relative of Tribolium castaneum, and cloned the cDNA for an AMP/CoA-ligase with luciferase-like enzyme properties. Using this cDNA library, we randomly isolated, partially sequenced and analyzed ca. 540 clones, obtaining the first transcriptional profile of the most representative expressed genes, and associated them with their possible biological functions. A high percentage of mitochondrial genes was found, which is consistent with the high metabolic activity required by this organ during the formation of primary urine. Common transcripts included those for enzymes involved in osmoregulation, such as solute transporters and ATPases, and in detoxification and excretion, such as cytochrome P450, glutathione S-transferase, alcohol dehydrogenase. The presence of AMP/CoA-ligases, which activate exogenous carboxylic acids such as firefly D-luciferin suggests their participation in important new xenobiotic excretion/detoxification roles in Malpighian tubule physiology.


Assuntos
Besouros/genética , Túbulos de Malpighi/metabolismo , Transcrição Gênica , Animais , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/genética , Mitocôndrias/metabolismo
13.
Anal Bioanal Chem ; 406(2): 611-20, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24253412

RESUMO

A simple method for the simultaneous determination of glufosinate and its metabolites in plants based on liquid chromatography-ultraviolet (LC-UV) absorption detection after derivatization with fluorenylmethoxycarbonyl chloride (FMOC-Cl) of some analytes to facilitate separation is reported here. Nonavailable standard metabolites were identified by LC-TOF/mass spectrometry (MS), which also confirmed all target analytes. Ultrasound-assisted extraction was used for sample preparation (power of 70 W and duty cycle of 0.7 s/s for 10 min) with subsequent evaporation of the extractant, reconstitution and filtration as the cleanup/concentration step prior to derivatization, and chromatographic separation and detection at 270 nm for underivatized analytes and 340 nm for those that were derivatized. The chromatographic analysis was completed in 40 min using a Luna® column (C18 phase). The analytical characteristics of the method were linear dynamic range of the calibration curves within 0.047-700 µg/mL with a regression coefficient (rc) of 0.999 for glufosinate, 0.077-700 µg/mL with a rc of 0.998 for N-acetyl-glufosinate, and 0.116-600 µg/mL with a rc of 0.998 for 3-(methylphosphinico)propanoic acid. The precision for the determination of glufosinate (studied at two levels, 0.1 and 5 µg/mL) was 2.7 and 6.0 % for repeatability and 4.7 and 7.2 % for within-laboratory reproducibility, respectively. Identification and confirmatory analysis of the presence of glufosinate and metabolites in the extracts from treated plants was carried out by LC-TOF/MS in high-resolution mode for the precursor ion. The method was validated by analyzing wheat (Triticum aestivum) samples (resistant and susceptible biotypes) treated with 300 g of glufosinate/ha following conventional agronomical practices.


Assuntos
Aminobutiratos/análise , Herbicidas/análise , Extratos Vegetais/química , Triticum/química , Calibragem , Propionatos/análise , Reprodutibilidade dos Testes , Sonicação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Anal Bioanal Chem ; 406(2): 611-20, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24555202

RESUMO

A simple method for the simultaneous determination of glufosinate and itsmetabolites in plants based on liquid chromatography­ultraviolet (LC­UV) absorption detection after derivatization with fluorenylmethoxycarbonyl chloride (FMOC-Cl) of some analytes to facilitate separation is reported here. Nonavailable standard metabolites were identified by LC­TOF/mass spectrometry (MS), which also confirmed all target analytes. Ultrasound-assisted extraction was used for sample preparation (power of 70 Wand duty cycle of 0.7 s/s for 10 min) with subsequent evaporation of the extractant, reconstitution and filtration as the cleanup/concentration step prior to derivatization, and chromatographic separation and detection at 270 nm for underivatized analytes and 340 nm for those that were derivatized. The chromatographic analysis was completed in 40 min using a Luna® column (C18 phase). The analytical characteristics of the method were linear dynamic range of the calibration curves within 0.047­700 µg/mL with a regression coefficient (rc) of 0.999 for glufosinate, 0.077­700 µg/mL with a rc of 0.998 for N-acetyl-glufosinate, and 0.116­600 µg/mL with a rc of 0.998 for 3-(methylphosphinico)propanoic acid. The precision for the determination of glufosinate (studied at two levels, 0.1 and 5 µg/mL) was 2.7 and 6.0 % for repeatability and 4.7 and 7.2%for within-laboratory reproducibility, respectively. Identification and confirmatory analysis of the presence of glufosinate and metabolites in the extracts from treated plants was carried out by LC­TOF/MS in high-resolution mode for the precursor ion. The method was validated by analyzing wheat (Triticum aestivum) samples (resistant and susceptible biotypes) treated with 300 g of glufosinate/ha following conventional agronomical practices.


Assuntos
Aminobutiratos/análise , Herbicidas/análise , Extratos Vegetais/química , Triticum/química , Calibragem , Propionatos/análise , Reprodutibilidade dos Testes , Sonicação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
Biochemistry ; 52(23): 3963-73, 2013 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-23705763

RESUMO

The origin of luciferases and of bioluminescence is enigmatic. In beetles, luciferases seem to have evolved from AMP-CoA-ligases. How the new oxygenase luminogenic function originated from AMP-ligases leading to luciferases is one of the most challenging mysteries of bioluminescence. Comparison of the cloned luciferase-like enzyme from the nonluminescent Zophobas morio mealworm and beetle luciferases showed that the oxygenase activity may have emerged as a stereoselective oxidative drift with d-luciferin, a substrate that cannot be easily thioesterified to CoA as in the case of the l-isomer. While the overall kcat displayed by beetle luciferases is orders of magnitude greater than that of the luciferase-like enzyme, the respective oxidation rates and quantum yields of bioluminescence are roughly similar, suggesting that the rate constant of the AMP-ligase activity exerted on the new d-luciferin substrate in beetle protoluciferases was the main enzymatic property that suffered optimization during the evolution of luciferases. The luciferase-like enzyme and luciferases boost the rate of luciferyl-adenylate chemiluminescent oxidation by factors of 10(6) and 10(7), respectively, as compared to the substrate spontaneous oxidation in buffer. A similar enhancement of luciferyl-adenylate chemiluminescence is provided by nucleophilic aprotic solvents, implying that the peptide bonds in the luciferin binding site of beetle luciferase could provide a similar catalytically favorable environment. These data suggest that the luciferase-like enzyme and other similar AMP-ligases are potential alternative oxygenases. Site-directed mutagenesis studies of the luciferase-like enzyme and the red light-producing luciferase of Phrixotrix hirtus railroadworm confirm here a critical role for T/S345 in luciferase function. Mutations such as I327T/S in the luciferase-like enzyme, which simultaneously increases luciferase activity and promotes blue shifts in the emission spectrum, could have been critical for evolving functional bioluminescence from red-emitting protoluciferases. Through the combination of I327T/S mutations and N-terminal fusion, the luminescence activity of this enzyme was increased to visible levels, with the development of a totally new orange-emitting luciferase. These results open the possibility of engineering luciferase activity in a set of AMP-CoA-ligases.


Assuntos
Coenzima A Ligases/química , Proteínas de Insetos/química , Luciferases/química , Acil Coenzima A/biossíntese , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Domínio Catalítico , Coenzima A Ligases/genética , Evolução Molecular , Luciferina de Vaga-Lumes/química , Corantes Fluorescentes/química , Proteínas de Insetos/genética , Cinética , Luciferases/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Naftalenossulfonatos/química , Ligação Proteica , Tenebrio/enzimologia
16.
Gene Ther ; 18(8): 827-34, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21390072

RESUMO

Malignant melanoma is one of the deadliest forms of skin cancer and its incidence is expected to rise over the next two decades. At present, there are no effective therapies for advanced melanoma. We have previously shown that administration of whole recombinant yeast expressing human MART-1 (hMART-IT) induces protective antimelanoma immunity in a B16F10 transplantable mouse model. In this study, we examine the effectiveness of the hMART-IT vaccine in a congenic strain of genetically engineered mouse model of melanoma, which recapitulates both the underlying genetics and the proper tumor microenvironment of naturally occurring melanoma. Subcutaneous administration of hMART-IT induced cytotoxicity against melanoma cells and antigen-specific production of Th1-specific cytokines by splenocytes. Weekly administration of hMART-IT significantly delayed the development of melanoma and prolonged the survival of mice compared with controls. Although histological analysis demonstrated diffuse infiltration of CD4(+) T cells and CD8(+) T cells, no reduction of regulatory T cells was observed, suggesting that hMART-IT cannot prevent immunotolerance in the tumor microenvironment. This study provides a proof of concept that genetically engineered mouse models lend valuable insights into immunotherapeutics being tested in the preclinical setting.


Assuntos
Vacinas Anticâncer/uso terapêutico , Modelos Animais de Doenças , Engenharia Genética , Melanoma Experimental/terapia , Vacinas Sintéticas/uso terapêutico , Animais , Citotoxicidade Imunológica , Antígeno MART-1/imunologia , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Saccharomyces cerevisiae/imunologia
17.
Photochem Photobiol Sci ; 10(7): 1226-32, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21505686

RESUMO

The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.


Assuntos
Luciferina de Vaga-Lumes/química , Corantes Fluorescentes/química , Luciferases/química , Tenebrio/enzimologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sítios de Ligação , Evolução Molecular , Vaga-Lumes/enzimologia , Luciferina de Vaga-Lumes/metabolismo , Luciferases/genética , Luciferases/metabolismo , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Estrutura Terciária de Proteína , Alinhamento de Sequência , Estereoisomerismo
18.
Prenat Diagn ; 31(6): 543-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21425298

RESUMO

OBJECTIVE: To evaluate the usefulness of first trimester fetal head and trunk volume (FHTV) in predicting growth disturbance in twin pregnancy. METHODS: We studied 46 twin pairs from 11 and 14 weeks to delivery. There were 35 dichorionic (76%) and 11 monochorionic (24%) pregnancies. FHTV was assessed by VOCALTM. An inter-twin discrepancy in FHTV, crown-rump length (CRL) and birthweight (BW) were defined by an inter-twin difference greater than 15%. Growth retardation was defined as BW of at least one twin below the 10th percentile. RESULTS: There were 17 cases (37%) of FHTV discrepancy. BW discrepancy and growth retardation were more significantly frequent in cases with FHTV discrepancy than without [11/17 (64.7%) vs 4/29 (13.8%), P = 0.0004 and 7/17 (41.2%) vs 3/29 (10.3%), P = 0.02, respectively]. The detection of BW discordance and growth retardation were significantly higher when using FHTV discordance than CRL discrepancy in the first trimester [11/15 (73%) vs 2/15 (13.3%), P = 0.00001 and 7/10 (70%) vs 1/10 (10%), P = 0.0001, respectively]. CONCLUSION: FHTV discrepancy is a predictor for growth disturbance in twins.


Assuntos
Doenças em Gêmeos/diagnóstico por imagem , Retardo do Crescimento Fetal/diagnóstico por imagem , Cabeça/diagnóstico por imagem , Primeiro Trimestre da Gravidez , Tórax/diagnóstico por imagem , Adulto , Estudos de Coortes , Estatura Cabeça-Cóccix , Feminino , Cabeça/embriologia , Humanos , Estudos Longitudinais , Tamanho do Órgão , Gravidez , Gravidez Múltipla , Prognóstico , Tórax/embriologia , Gêmeos , Ultrassonografia Pré-Natal
19.
Commun Agric Appl Biol Sci ; 76(4): 909-14, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22702207

RESUMO

Lake Tota (Boyaca, Colombia) supplies water for human consumption, agriculture and industry for more than 500.000 people. Oxadixyl and Tebuconazole are fungicides used in onion crops in the lake catchment area. The mobility of pesticides in soil, bioavailability and transfer to other environmental compartments depend on sorption and desorption kinetics and mechanisms. An understanding of these processes is essential for transport modeling and the rational design of corrective measures against pollution. A displacement study was performed on a hand packed soil column in laboratory conditions. A pulse of 0,01 M CaCl2 solution, containing a tracer (Bromide) and the fungicides Oxadixyl y Tebuconazole, was injected. Column experiment was performed at 0.078 cmh(-1) flow rate under unsaturated conditions. Eluates were collected in flasks at constant intervals and the volumes of eluate were recorded. After rainfall simulation, the soil from the column was sliced into six successive sections (5 cm). Methanol extraction was used to determine the fungicide in each soil section. Samples were measured by HPLC. Only Oxadixyl was recovered in leachates. Unlike bromide breakthrough curve, Oxadixyl was asymmetrical, with early breakthrough and increased tailing. The percentage eluted was 96.7% after ten pore volumes. Tebuconazole showed the highest retention in the first five cm of soil layer. The results suggest that oxadyxil presents highs risk to leachate through the soil profile and that Tebuconazole is strongly absorbed in Colombian soil.


Assuntos
Acetamidas/química , Fungicidas Industriais/química , Oxazóis/química , Triazóis/química , Poluentes Químicos da Água/química , Colômbia , Monitoramento Ambiental
20.
Braz J Biol ; 82: e231742, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33787710

RESUMO

The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm2, 13.19 mW/cm2 and 603.44 J/cm2, 27.93 mW/cm2 respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos , Humanos , Luz , Pseudomonas aeruginosa
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