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1.
Mem Inst Oswaldo Cruz ; 115: e190469, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32638832

RESUMO

BACKGROUND Oxidative stress is responsible for generating DNA lesions and the 8-oxoguanine (8-oxoG) is the most commonly lesion found in DNA damage. When this base is incorporated during DNA replication, it could generate double-strand DNA breaks and cellular death. MutT enzyme hydrolyzes the 8-oxoG from the nucleotide pool, preventing its incorporation during DNA replication. OBJECTIVES To investigate the importance of 8-oxoG in Leishmania infantum and L. braziliensis, in this study we analysed the impact of heterologous expression of Escherichia coli MutT (EcMutT) enzyme in drug-resistance phenotype and defense against oxidative stress. METHODS Comparative analysis of L. braziliensis and L. infantum H2O2 tolerance and cell cycle profile were performed. Lines of L. braziliensis and L. infantum expressing EcMutT were generated and evaluated using susceptibility tests to H2O2 and SbIII, cell cycle analysis, γH2A western blotting, and BrdU native detection assay. FINDINGS Comparative analysis of tolerance to oxidative stress generated by H2O2 showed that L. infantum is more tolerant to exogenous H2O2 than L. braziliensis. In addition, cell cycle analysis showed that L. infantum, after treatment with H2O2, remains in G1 phase, returning to its normal growth rate after 72 h. In contrast, after treatment with H2O2, L. braziliensis parasites continue to move to the next stages of the cell cycle. Expression of the E. coli MutT gene in L. braziliensis and L. infantum does not interfere in parasite growth or in susceptibility to SbIII. Interestingly, we observed that L. braziliensis EcMutT-expressing clones were more tolerant to H2O2 treatment, presented lower activation of γH2A, a biomarker of genotoxic stress, and lower replication stress than its parental non-transfected parasites. In contrast, the EcMutT is not involved in protection against oxidative stress generated by H2O2 in L. infantum. MAIN CONCLUSIONS Our results showed that 8-oxoG clearance in L. braziliensis is important to avoid misincorporation during DNA replication after oxidative stress generated by H2O2.


Assuntos
Antimônio/toxicidade , Proteínas de Escherichia coli/genética , Escherichia coli , Guanina/análogos & derivados , Leishmania braziliensis/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Pirofosfatases , Superóxido Dismutase/metabolismo , Animais , Antiprotozoários/farmacologia , Proteínas de Escherichia coli/metabolismo , Guanina/farmacologia , Humanos , Peróxido de Hidrogênio/toxicidade , Leishmania braziliensis/enzimologia , Leishmania infantum/enzimologia , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Pirofosfatases/genética , Pirofosfatases/metabolismo , Coelhos , Ratos , Superóxido Dismutase/genética
2.
Am J Vet Res ; 81(8): 642-650, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32700996

RESUMO

OBJECTIVE: To determine effects of PCV on blood glucose (BG) concentration measurements obtained with a human portable blood glucometer (HPBG) and a veterinary portable blood glucometer (VPBG) on canine (cVPBG) and feline (fVPBG) settings (test methods) when used in rabbits and to develop correction formulas to mitigate effects of PCV on such measurements. SAMPLE: 48 resuspended blood samples with known PVCs (range, 0% [plasma] to 92% [plasma and packed RBCs]) from 6 healthy research rabbits (experimental sample set) and 252 historic measurements of BG concentration and PCV in 84 client-owned rabbits evaluated at a veterinary hospital (validation data set). PROCEDURES: Duplicate measurements of BG concentration with each test method and of PCV were obtained for each sample in the experimental sample set, and the mean results for each variable for each test method and sample were compared with results from a clinical laboratory analyzer (reference method) used to determine the true BG concentration for each sample. Mean ± SD differences in measurements between the reference and test methods were calculated. Linear regression and modified Clarke error grid analysis were used to develop correction formulas for the test methods given known PCVs, and these formulas were evaluated on the validation data set with linear regression and a modified Clarke error grid. RESULTS: Blood glucose concentrations were falsely low for cVPBG and fVPBG used on samples with PCV < 31% and were falsely high for all test methods used on samples with PCV > 43%. Compared with original measurements, formula-corrected measurements overall had better agreement with reference method measurements for the experimental sample set; however, only the formula-corrected HPBG measurements had improved agreement for the validation data set. CONCLUSIONS AND CLINICAL RELEVANCE: Findings indicated that, in rabbits, HPBG measurements had improved accuracy with the use of the correction formula HPBG measurement of BG concentration + ([0.75 × PCV] - 15); however, the correction formulas did not improve the accuracy of VPBG measurements, and we believe that neither the cVPBG nor fVPBG should be used in rabbits.


Assuntos
Glicemia , Sistemas Automatizados de Assistência Junto ao Leito , Animais , Automonitorização da Glicemia/veterinária , Gatos , Tamanho Celular , Cães , Modelos Lineares , Coelhos
3.
Vaccine ; 38(35): 5653-5658, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32651113

RESUMO

The COVID-19 outbreak has become a global pandemic responsible for over 2,000,000 confirmed cases and over 126,000 deaths worldwide. In this study, we examined the immunogenicity of CHO-expressed recombinant SARS-CoV-2 S1-Fc fusion protein in mice, rabbits, and monkeys as a potential candidate for a COVID-19 vaccine. We demonstrate that the S1-Fc fusion protein is extremely immunogenic, as evidenced by strong antibody titers observed by day 7. Strong virus neutralizing activity was observed on day 14 in rabbits immunized with the S1-Fc fusion protein using a pseudovirus neutralization assay. Most importantly, in <20 days and three injections of the S1-Fc fusion protein, two monkeys developed higher virus neutralizing titers than a recovered COVID-19 patient in a live SARS-CoV-2 infection assay. Our data strongly suggests that the CHO-expressed SARS-CoV-2 S1-Fc recombinant protein could be a strong candidate for vaccine development against COVID-19.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/imunologia , Fragmentos Fc das Imunoglobulinas/química , Macaca/imunologia , Pneumonia Viral/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Animais , Células CHO , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Cricetulus , Feminino , Células HEK293 , Humanos , Imunização Passiva , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Masculino , Camundongos , Pandemias , Coelhos
4.
Acta Cir Bras ; 35(4): e202000405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555937

RESUMO

PURPOSE: To investigate the effects of Chemically Extracted Acellular Nerves (CEANs) when combined with Adipose-Derived mesenchymal Stem Cell (ADSC) transplantation on the repair of sciatic nerve defects in rabbits. METHODS: A total of 71 six-month-old Japanese rabbit were used in this study. Twenty rabbits served as sciatic nerve donors, while the other 51 rabbits were randomly divided into Autologous Nerve Transplantation Group (ANT, n=17), CEAN group (n=17) and CEAN-ADSCs group (n=17). In all these groups, the rabbit's left sciatic nerves were injured before the experiment, and the uninjured sciatic nerves on their right side were used as the control (CON). Electrophysiological tests were carried out and sciatic nerves were prepared for histomorphology and stretch testing at 24 weeks post-transplant. RESULTS: There were significant differences between ANT and Con groups in amplitude (AMP): P=0.031; motor nerve conduction velocity (MNCV): P=0.029; Maximum stress: P=0.029; and Maximum strain P=0.027. There were also differences between the CEAN and CEAN+ADSCs groups in AMP: P=0.026, MNCV: P=0.024; Maximum stress: P=0.025 and Maximum strain: P=0.030. No significant differences in these parameters were observed when comparing the ANT and CEAN+SACN groups (MNCV: P=0.071) or the CEAN and ANT groups (Maximum stress: P=0.069; Maximum strain P=0.077). CONCLUSION: Addition of ADSCs has a significant impact on the recovery of nerve function, morphology, and tensile mechanical properties following sciatic nerve injury.


Assuntos
Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais , Tecido Nervoso/transplante , Neuropatia Ciática/fisiopatologia , Neuropatia Ciática/cirurgia , Animais , Fenômenos Biomecânicos , Eletromiografia , Masculino , Regeneração Nervosa/fisiologia , Tecido Nervoso/citologia , Coelhos , Valores de Referência , Reprodutibilidade dos Testes , Nervo Isquiático/fisiopatologia , Nervo Isquiático/cirurgia , Resultado do Tratamento
5.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(3): 240-244, 2020 Jun 01.
Artigo em Chinês | MEDLINE | ID: mdl-32573128

RESUMO

OBJECTIVE: This study aimed to compare the cartilage regeneration of the stromal vascular fraction (SVF) cells and adipose-derived mesenchymal stem cells (ASCs) cocultured with chondrocytes seeded on the scaffolds. METHODS: The cellular morphologies and proliferation capabilities on the scaffolds were evaluated. The scaffolds with the cocul-ture of ASCs/SVF and chondrocytes were implanted into the full thickness cartilage defective rabbit joints for 10 weeks. RESULTS: The cells seeded into the scaffolds showed good adhesion and proliferation. Implantation with SVF and chondrocytes revealed desirable in vitro healing outcomes. CONCLUSIONS: The SVF cells were better than ASCs in terms of the formation of cartilage matrix in a coimplantation model. Without in vitro expansion, the SVF cells are good cell sources for cartilage repair.


Assuntos
Cartilagem , Condrócitos , Tecido Adiposo , Animais , Técnicas de Cocultura , Coelhos , Regeneração
6.
BMC Infect Dis ; 20(1): 426, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32552685

RESUMO

BACKGROUND: A previous phase 2 study demonstrated the immunogenicity of a single dose of meningococcal A, C, W, Y-tetanus toxoid conjugate (MenACWY-TT) or polysaccharide (MenACWY-PS) vaccine for up to 5 years in individuals aged 11-55 years. This follow-up study evaluated long-term antibody persistence up to 10 years and the immunogenicity and safety of a single MenACWY-TT booster dose given 10 years after primary vaccination. METHODS: Blood draws were conducted annually in Years 7-10. At Year 10, all subjects received a MenACWY-TT booster dose. Blood was drawn at 1 month and safety data were collected ≤6 months postbooster. Study endpoints included immunogenicity during the persistence phase (primary), and immunogenicity and safety during the booster phase (secondary). Statistical analyses were descriptive. RESULTS: A total of 311 subjects were enrolled in the persistence phase (MenACWY-TT, 235; MenACWY-PS, 76); 220 were enrolled in the booster phase (MenACWY-TT, 164; MenACWY-PS, 56). Descriptive analyses indicated that at Years 7-10, the percentages of subjects achieving serum bactericidal antibody assay using baby rabbit complement (rSBA) titers ≥1:8 and ≥1:128 were higher for serogroups A, W, and Y in the MenACWY-TT versus MenACWY-PS group; percentages were similar across groups for serogroup C. rSBA geometric mean titers (GMTs) for serogroups A, W, and Y were higher in the MenACWY-TT group and slightly higher in the MenACWY-PS group for serogroup C. One month postbooster, all primary MenACWY-TT and ≥98.1% of primary MenACWY-PS recipients had rSBA titers ≥1:8. For all serogroups, rSBA GMTs postbooster were higher in the MenACWY-TT versus MenACWY-PS group. Most local and general reactogenicity events were similar between groups and mild to moderate in severity. Adverse events at 1 month postbooster were 9.1% for the MenACWY-TT and 3.6% for the MenACWY-PS groups; all were nonserious. CONCLUSIONS: Immune responses to a single MenACWY-TT primary dose administered at age 11-55 years persisted in >70% of individuals evaluated at Years 7-10. A MenACWY-TT booster dose administered at Year 10 was safe and immunogenic with no new safety signals observed. These results provide important insights regarding long-term protection from primary vaccination and the benefits of booster dosing. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01934140. Registered September 2013.


Assuntos
Anticorpos Antibacterianos/sangue , Vacinas Meningocócicas/imunologia , Adolescente , Adulto , Animais , Criança , Proteínas do Sistema Complemento , Hipersensibilidade a Drogas , Feminino , Seguimentos , Humanos , Imunização Secundária , Masculino , Pessoa de Meia-Idade , Neisseria meningitidis/imunologia , Coelhos , Sorogrupo , Fatores de Tempo , Vacinas Conjugadas/imunologia , Adulto Jovem
7.
Int J Nanomedicine ; 15: 3433-3445, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523342

RESUMO

Background: Reconstituted lipoproteins (rLips) based on endogenous lipid nanostructures has been increasingly regarded as an excellent and promising antitumor drug delivery. However, some problems relating to the main component, apolipoprotein, for instance, rare source, unaffordable price, and low specificity of relevant receptor expression, become chief obstacles to its broad development and application. Purpose: The primary aim of this study is to develop biomimetic rLips by utilizing folic acid (FA)-modified bovine serum albumin (BSA) as a replacement for apolipoprotein and demonstrate its tumor targeting and antitumor efficacy. Methods: The amino groups of BSA were covalently conjugated with FA through the amide reaction. PTX-loaded nanostructured lipid carrier (termed as P-NLC) consisting of phospholipid, cholesteryl ester, triglyceride and cholesterol was prepared by the emulsification-evaporation method and utilized as the lipid core. FA-modified BSA (FA-BSA) was characterized for the protein substitute degree and attached with NLC by incubation-insert method to form the lipoprotein-mimic nanocomplex (termed as PFB-rLips). The morphology of nanoparticles was observed under transmission electron microscopy (TEM), and the particle size and zeta potential were determined using dynamic light scattering. In vitro release behavior of PTX from PFB-rLips was investigated with the dialysis method. Hemolysis tests were conducted to evaluate the biosecurity of PFB-rLips. Cell uptake and cytotoxicity assays were performed on human hepatocytes (LO2) and human hepatoma cells (HepG2). Tumor targeting was assessed using in vivo imaging system in H22 tumor-bearing mice model. Antitumor efficacy in vivo was investigated and compared between Taxol® (paclitaxel) formulation and PTX-incorporated nanoparticles in the same tumor model. Results: A fixed molar ratio 50:1 of FA to BSA was chosen as the optimal input ratio based on the balance between appropriate degree of protein substitution and amphiphilicity of FA-BSA. The morphology of FB-rLips exhibited as a homogeneous spherical structure featured by lipid cores surrounded with a cloudy protein shell observed under TEM. The particle size, zeta potential and encapsulation efficiency were 174.6±3.2 nm, -17.26±0.9 mV and 82.2±2.4%, respectively. In vitro release behavior of PTX from PFB-rLips was slow and sustained. The uptake of FB-rLips was much higher in HepG2 cells than in LO2 cells. Furthermore, the uptake of FB-rLips was significantly higher than that of rLips without FA involved (termed as B-rLips) and NLC in HepG2 cells. Hemolysis and cytotoxicity assays showed good biocompatibility of FB-rLips. The internalization mechanism of FB-rLips mainly depended on clathrin-mediated and caveolin-mediated endocytosis coupling with energy consumption, and FA receptors expressed on tumor cells played a critical role in cellular uptake process. CCK-8 studies demonstrated that PFB-rLips exhibited significantly better tumor killing ability than Taxol® (paclitaxel) formulation in vitro. Moreover, FB-rLips produced more excellent tumor-targeting properties than NLC through in vivo imaging assays. On the basis of this, PTX-loaded FB-rLips also performed more remarkable anticancer activity than other therapy groups in H22 tumor-bearing mice. Conclusion: FB-rLips would serve as a potential nanocarrier for improving tumor-targeting and therapeutic efficacy while reducing the side effects on normal tissues and organs.


Assuntos
Portadores de Fármacos/química , Ácido Fólico/uso terapêutico , Lipoproteínas/química , Nanopartículas/química , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Ácido Fólico/síntese química , Ácido Fólico/química , Hemólise/efeitos dos fármacos , Humanos , Camundongos , Nanopartículas/ultraestrutura , Neoplasias/patologia , Paclitaxel/química , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Tamanho da Partícula , Coelhos , Soroalbumina Bovina/química , Eletricidade Estática
8.
Sci Transl Med ; 12(550)2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32513867

RESUMO

Multiple vaccine candidates against SARS-CoV-2 based on viral spike protein are under development. However, there is limited information on the quality of antibody responses generated with these vaccine modalities. To better understand antibody responses induced by spike protein-based vaccines, we performed a qualitative study by immunizing rabbits with various SARS-CoV-2 spike protein antigens: S ectodomain (S1+S2; amino acids 16 to 1213), which lacks the cytoplasmic and transmembrane domains (CT-TM), the S1 domain (amino acids 16 to 685), the receptor binding domain (RBD) (amino acids 319 to 541), and the S2 domain (amino acids 686 to 1213, lacking the RBD, as control). Resulting antibody quality and function were analyzed by enzyme-linked immunosorbent assay (ELISA), RBD competition assay, surface plasmon resonance (SPR) against different spike proteins in native conformation, and neutralization assays. All three antigens (S1+S2 ectodomain, S1 domain, and RBD), but not S2, generated strong neutralizing antibodies against SARS-CoV-2. Vaccination-induced antibody repertoire was analyzed by SARS-CoV-2 spike genome fragment phage display libraries (SARS-CoV-2 GFPDL), which identified immunodominant epitopes in the S1, S1-RBD, and S2 domains. Furthermore, these analyses demonstrated that the RBD immunogen elicited a higher antibody titer with five-fold higher affinity antibodies to native spike antigens compared with other spike antigens, and antibody affinity correlated strongly with neutralization titers. These findings may help guide rational vaccine design and facilitate development and evaluation of effective therapeutics and vaccines against COVID-19 disease.


Assuntos
Anticorpos Antivirais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Formação de Anticorpos/imunologia , Antígenos Virais/imunologia , Epitopos/imunologia , Feminino , Imunização , Testes de Neutralização , Coelhos
9.
Int J Nanomedicine ; 15: 3953-3964, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32581539

RESUMO

Objective: To construct an ideal theranostic nanoplatform (LIP3); to clarify its physicochemical properties; to confirm its characteristics of dual-modality imaging, active-targeting, and cascade amplification therapy for mammary carcinoma; and to perform a preliminary exploration of the cytotoxicity mechanism. Design: A self-prepared liposome nanosystem, LIP3, can actively target 4T1 cells because the surface is linked with C-RGD. Haematoporphyrin monomethyl ether (HMME), an excellent sonosensitizer entrapped in the lipid bilayer, can function in photoacoustic imaging. Low-intensity focused ultrasound (LIFU) of ultrasound-targeted microbubble destruction (UTMD) promotes localized drug delivery into tumours because PFH, a phase-change substance, is loaded in the LIP3 core, achieving visualization of targeted drug release, and sonodynamic therapy (SDT) can kill tumour cells. SDT provides a favourable environment for AQ4N, resulting in amplification of LIP3 treatment. Therefore, LIP3 shows targeted aggregation and targeted release, integrating dual-mode imaging and precise treatment. Results: The self-prepared lipid nanosystem, LIP3, meets the above expectations and has ideal physicochemical properties, with a regular sphere with uniform distribution. Contrast-enhanced ultrasound (CEUS), photoacoustic imaging, and bimodal imaging were effective in vitro. In 4T1 cell experiments, the cell capacity was as high as 42.9%, and the cytotoxicity to 4T1 was more than 5 times that of LIP1 (containing AQ4N only) and more than 2 times that of LIP2 (containing only HMME), achieving comparable results as cascade therapy for mammary cancer. Conclusion: LIP3, a theranostic nanoplatform, was successfully constructed and conformed to the physicochemical characterization of ideal nanoparticles, with active-targeting, dual-modality imaging, visualized drug release, and precise treatment under the action of LIFU. SDT provides a favourable environment for AQ4N, resulting in amplification of LIP3 treatment. Therefore, LIP3 shows targeted aggregation and targeted release, integrating dual-mode imaging, and precise cascade treatment. This unique theranostic NPS with multiple capabilities is expected to be a favourable anti-cancer method in the future.


Assuntos
Neoplasias da Mama/terapia , Nanopartículas/química , Nanomedicina Teranóstica/métodos , Animais , Neoplasias da Mama/diagnóstico por imagem , Linhagem Celular Tumoral , Meios de Contraste/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Feminino , Hematoporfirinas/química , Humanos , Lipídeos/química , Lipossomos/química , Camundongos Nus , Nanopartículas/uso terapêutico , Oligopeptídeos/química , Coelhos , Ultrassonografia de Intervenção/métodos
10.
Zhonghua Yi Xue Za Zhi ; 100(21): 1662-1667, 2020 Jun 02.
Artigo em Chinês | MEDLINE | ID: mdl-32486603

RESUMO

Objective: To observe the effect of different modes of mechanical ventilation on patient-ventilator synchrony and diaphragm function in rabbits with acute respiratory distress syndrome(ARDS). Methods: Eighteen New Zealand rabbit models of ARDS were induced by intratracheal infusion hydrochloric acid until the oxygenation index (PaO(2)/FiO(2)) was less than 200 mmHg, and then divided into three groups with random number: assisted-controlled mechanical ventilation (A/C) group, pressure support ventilation (PSV) group and neurally adjusted ventilatory assist (NAVA) group. All of them were ventilated for four hours with the targeted tidal volume (V(T)) (6 ml/kg) and the positive end-expiratory pressure (PEEP) titrated with the maximum oxygenation method. Gas exchange, pulmonary mechanics and patient-ventilator synchrony were determined during 4 h of ventilation and the concentrations of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) in diaphragm were measured after 4 h of ventilation. The q test was used for the multiple comparison of the sample mean. Results: There were no significant differences in PaO(2)/FiO(2) between three groups during ventilation 1-4 h (F=1.029, P>0.05). The V(T) in NAVA group was obviously lower than that in PSV group and the respiratory rate (RR) and the electrical activity of diaphragm(EAdi) were higher than those in A/C group(all P<0.05).The trigger delay and off cycle delay the in NAVA group were markedly lower than those in A/C and PSV group during ventilation 1-4 h(F=14.312, 9.342, both P<0.05). Asynchrony index in NAVA group (3.1%±1.0%) was obviously lower than those in A/C group (22.3%±5.2%) and PSV group(8.4%±2.3%) (F=7.192, P<0.05). In NAVA group, peak EAdi (EAdi(peak)) and peak airway pressure (Ppeak) were markedly correlated (r=0.97±0.16, P<0.05), while Ppeak delivery in A/C and PSV group was not correlated to EAdi(peak) (r=0.38±0.13,0.46±0.15, both P>0.05).Compared with A/C group, the concentration of MDA in the diaphragm in NAVA group was obviously lower(P<0.05). SOD and GSH level inthe diaphragm in NAVA group were both obviously higher than those in A/C group (both P<0.05). Conclusions: It is helpful to avoid eccentric contraction of diaphragm, lessen oxidative stress and alleviate ventilator-related diaphragm dysfunction by keeping spontaneous breathing as far as possible and subject-ventilator synchrony when ventilation in ARDS with NAVA.


Assuntos
Diafragma , Síndrome do Desconforto Respiratório do Adulto , Animais , Humanos , Coelhos , Respiração Artificial , Ventiladores Mecânicos
11.
Vet Rec ; 186(18): 612, 2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32527906
12.
Acta Cir Bras ; 35(4): e202000403, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578723

RESUMO

PURPOSE: To collect data capable of pointing out the effects of the ultracavitation treatment on the liver of rabbits after adipose tissue application, by means of histological analyses of the liver and hematological and biochemical exams. METHODS: This is an experimental study with 12 albino rabbits as sample, which were divided into 3 groups and submitted to a hypercaloric diet for one month. Subsequently, subjects underwent UCV treatment: 3 minutes, 30 W, continuous mode at 100%, every 2 ERAS = 441.02 J/cm2, intensity of 10w/cm2. They were then euthanized and underwent biopsy after 24 hours. RESULTS: After 48 hours from the ultracavitation treatment, the animals' livers presented greater amount of fat infiltration if compared to the amount presented 96 hours after the treatment. However, laboratory tests showed no alterations. Values were maintained within normal parameters of cholesterol, triglycerides, liver enzymes, hemoglobin and hematocrit levels. CONCLUSIONS: This study has identified that infiltrates may appear on livers after the treatment, despite high hematological and biochemical tests results. The fat infiltrates reduction 96 h after treatment suggests lower risks to animal health, if the period between applications is respected.


Assuntos
Tecido Adiposo/patologia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Lipodistrofia/patologia , Lipodistrofia/terapia , Fígado/patologia , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Colesterol/sangue , Feminino , Hematócrito , Hemoglobinas/análise , Ablação por Ultrassom Focalizado de Alta Intensidade/efeitos adversos , Lipodistrofia/sangue , Masculino , Coelhos , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Resultado do Tratamento , Triglicerídeos/sangue
13.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(3): 564-569, 2020 Jun 18.
Artigo em Chinês | MEDLINE | ID: mdl-32541993

RESUMO

OBJECTIVE: To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics. METHODS: The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility. RESULTS: In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time. CONCLUSION: In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.


Assuntos
Materiais Biocompatíveis/metabolismo , Animais , Regeneração Óssea , Tecido Conjuntivo , Mucosa Intestinal , Intestino Delgado , Membranas Artificiais , Coelhos
14.
J Oral Sci ; 62(3): 340-343, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32493867

RESUMO

Interleukin-1α (IL-1α) is produced inside cells in its precursor form (pIL-1α). Enzymatic cleavage yields mature (mIL-1α) and the propiece of IL-1α (ppIL-1α), which are thought to be localized in the nucleus, because of the presence of nuclear localizing signals. Studies of ppIL-1α function have been hampered by the lack of a ppIL-1α-specific antibody (Ab). In the present study, the authors generated anti-ppIL-1α Ab by using recombinant histidine-tagged ppIL-1α (His-ppIL-1α) as an immunogen. Rabbits were immunized with His-ppIL-1α, and affinity-purified Ab was obtained. Ab reactivity and specificity were examined by Western blotting. The antibody successfully recognized transfectant-derived green fluorescence protein (GFP)-tagged ppIL-1α but not GFP. A sandwich enzyme-linked immunosorbent assay (ELISA) system established by biotinylating the anti-ppIL-1α Ab successfully detected GFP-ppIL-1α. The Ab and ELISA system allows functional analysis of ppIL-1α and improves understanding of ppIL-1α.


Assuntos
Interleucina-1alfa , Animais , Western Blotting , Ensaio de Imunoadsorção Enzimática , Coelhos
15.
J Oral Implantol ; 46(3): 221-226, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32582918

RESUMO

The aim of this study was to evaluate the effect of autogenous tooth bone graft (ATBG) combined with platelet-rich fibrin (PRF) on bone healing in rabbit peri-implant osseous defects. Eighteen New Zealand rabbits were divided into 3 groups. Bone defects were prepared in each rabbit, and then an implant cavity was created in the defects. Dental implants were placed, and the peri-implant bone defects were treated with the following 3 methods: no graft material was applied in the control group, bone defects were treated with ATBG in the ATBG group, and bone defects were treated with ATBG combined with PRF in the ATBG+PRF group. After 28 days, the rabbits were sacrificed, and the dental implants with surrounding bone were removed. New bone formation and the percentage of bone-to-implant contact (BIC) were determined with histomorphometric evaluations. New bone formation was significantly higher in the ATBG+PRF group than the control and ATBG groups (P < .05). In addition, BIC was significantly higher in the ATBG+PRF group than in the control and ATBG groups (P < .05). The combination of ATBG with PRF contributed to bone healing in rabbits with peri-implant bone defects.


Assuntos
Implantes Dentários , Fibrina Rica em Plaquetas , Animais , Regeneração Óssea , Transplante Ósseo , Fibrina , Coelhos
16.
Sci Immunol ; 5(48)2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32527802

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that first emerged in late 2019 is responsible for a pandemic of severe respiratory illness. People infected with this highly contagious virus can present with clinically inapparent, mild, or severe disease. Currently, the virus infection in individuals and at the population level is being monitored by PCR testing of symptomatic patients for the presence of viral RNA. There is an urgent need for SARS-CoV-2 serologic tests to identify all infected individuals, irrespective of clinical symptoms, to conduct surveillance and implement strategies to contain spread. As the receptor binding domain (RBD) of the spike protein is poorly conserved between SARS-CoVs and other pathogenic human coronaviruses, the RBD represents a promising antigen for detecting CoV-specific antibodies in people. Here we use a large panel of human sera (63 SARS-CoV-2 patients and 71 control subjects) and hyperimmune sera from animals exposed to zoonotic CoVs to evaluate RBD's performance as an antigen for reliable detection of SARS-CoV-2-specific antibodies. By day 9 after the onset of symptoms, the recombinant SARS-CoV-2 RBD antigen was highly sensitive (98%) and specific (100%) for antibodies induced by SARS-CoVs. We observed a strong correlation between levels of RBD binding antibodies and SARS-CoV-2 neutralizing antibodies in patients. Our results, which reveal the early kinetics of SARS-CoV-2 antibody responses, support using the RBD antigen in serological diagnostic assays and RBD-specific antibody levels as a correlate of SARS-CoV-2 neutralizing antibodies in people.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Epitopos Imunodominantes/imunologia , Pneumonia Viral/diagnóstico , Domínios Proteicos/imunologia , Glicoproteína da Espícula de Coronavírus/química , Zoonoses/sangue , Animais , Anticorpos Monoclonais , Anticorpos Neutralizantes , Infecções por Coronavirus/sangue , Infecções por Coronavirus/virologia , Humanos , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/virologia , Ligação Proteica , Coelhos , Vírus da SARS/química , Vírus da SARS/imunologia , Testes Sorológicos , Zoonoses/virologia
17.
Am J Vet Res ; 81(7): 565-571, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32584181

RESUMO

OBJECTIVE: To determine whether luteinizing hormone receptors (LHRs) are expressed in canine femoral head subchondral bone (FHSB), hip joint round ligament (RL), cranial cruciate ligament (CCL), and femorotibial joint synovium (FJS) specimens. SAMPLE: 1 specimen each of the FHSB, RL, CCL, and FJS obtained from the left hind limbs of 19 fresh canine cadavers. PROCEDURES: 1 section of each FHSB, RL, CCL, and FJS specimen was processed with rabbit polyclonal IgG anti-human LHR antibody, and 1 section was treated with negative control reagents. Percentage immunoexpression of LHRs in FHSB and FJS sections was analyzed by assessment of 100 bone marrow cells or synoviocytes in 3 adjacent hpf (400×). In each RL and CCL section, immunoexpression of LHRs in fibrocytes was semiquantitatively analyzed on the basis of the mean of the product of percentage staining score (from 0 [no staining] to 3 [> 50% of cells stained]) and staining intensity score (from 0 [no staining] to 2 [moderate to strong staining]) for 3 adjacent hpf. RESULTS: All tissues examined had variable LHR expression. Expression of LHRs in FHSB, CCL, or FJS specimens did not differ between sexes or between sexually intact and gonadectomized dogs. However, RL specimens from female dogs had significantly greater LHR expression scores, compared with findings for male dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that LHRs are expressed in structural support tissues of canine hip and femorotibial joints. Further research is required to determine the LHRs' function, mechanism of action, and potential contribution to the pathogenesis of hip dysplasia or CCL rupture in dogs.


Assuntos
Lesões do Ligamento Cruzado Anterior/veterinária , Doenças do Cão , Animais , Ligamento Cruzado Anterior , Cães , Feminino , Masculino , Coelhos , Receptores do LH , Ruptura/veterinária
18.
Medicine (Baltimore) ; 99(20): e20091, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32443319

RESUMO

This study aims to evaluate the changes of fragility and ultrastructure of amniotic membrane after cross-linking by UVA/riboflavin.Forty-nine fresh amniotic membranes were randomly divided into 3 groups. Eighteen were in group A (CX group) and immersed in 0.1% riboflavin solution for 10 min for UVA/riboflavin cross-linking. Sixteen were in group B (B2 group), soaked for 10 min with 0.1% riboflavin. After soaking, membranes in group A and B were transferred into corneal preservation solution. Fifteen pieces were in group C, directly into corneal preservation solution. The biomechanical and ultrastructural changes of the amniotic tissue before and after cross-linking were examined (CX group = 13, B2 group = 11, C group = 15). The amniotic membrane tissue of group A (n = 5) and B (n = 5) was transplanted into 16 eyes of the rabbits, respectively, and the dissolution time of the amniotic membrane tissue was investigated.After cross-linking, compared with the control group, the elastic modulus of the low-stress area of the amniotic membrane (Elow) was higher, while the elastic modulus of the high-stress area of the amniotic membrane (Ehigh) was lower, with no significant difference in the tensile strength. Also, the collagen fibers showed coarse and bamboo-like changes. In group A, amniotic membranes began to dissolve 4 weeks after conjunctiva transplantation, and all amniotic membranes were dissolved and absorbed 6 weeks after conjunctiva transplantation. In group B, some amniotic membrane tissues were still visible 6 weeks after conjunctiva transplantation.This study suggested that after amniotic membrane cross-linking, the brittleness was increased, the hardness was enhanced, and the morphology of the collagen fiber was changed. The cross-linked amniotic membrane showed resistance to tissue dissolution.


Assuntos
Âmnio/fisiologia , Âmnio/ultraestrutura , Reagentes para Ligações Cruzadas , Riboflavina , Transplante , Raios Ultravioleta , Implantes Absorvíveis , Âmnio/efeitos dos fármacos , Âmnio/transplante , Animais , Colágeno/efeitos dos fármacos , Colágeno/efeitos da radiação , Módulo de Elasticidade , Olho , Humanos , Procedimentos Cirúrgicos Oftalmológicos , Soluções para Preservação de Órgãos , Coelhos , Distribuição Aleatória
19.
Int J Nanomedicine ; 15: 2885-2902, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32425522

RESUMO

Purpose: Poor site-specific delivery and insufficient intracellular drug release in tumors are inherent disadvantages to successful chemotherapy. In this study, an extraordinary polymeric micelle nanoplatform was designed for the efficient delivery of paclitaxel (PTX) by combining dual receptor-mediated active targeting and stimuli response to intracellular reduction potential. Methods: The dual-targeted redox-sensitive polymer, folic acid-hyaluronic acid-SS-vitamin E succinate (FHSV), was synthesized via an amidation reaction and characterized by 1H-NMR. Then, PTX-loaded FHSV micelles (PTX/FHSV) were prepared by a dialysis method. The physiochemical properties of the micelles were explored. Moreover, in vitro cytological experiments and in vivo animal studies were carried out to evaluate the antitumor efficacy of polymeric micelles. Results: The PTX/FHSV micelles exhibited a uniform, near-spherical morphology (148.8 ± 1.4 nm) and a high drug loading capacity (11.28% ± 0.25). Triggered by the high concentration of glutathione, PTX/FHSV micelles could quickly release their loaded drug into the release medium. The in vitro cytological evaluations showed that, compared with Taxol or single receptor-targeted micelles, FHSV micelles yielded higher cellular uptake by the dual receptor-mediated endocytosis pathway, thus leading to significantly superior cytotoxicity and apoptosis in tumor cells but less cytotoxicity in normal cells. More importantly, in the in vivo antitumor experiments, PTX/FHSV micelles exhibited enhanced tumor accumulation and produced remarkable tumor growth inhibition with minimal systemic toxicity. Conclusion: Our results suggest that this well-designed FHSV polymer has promising potential for use as a vehicle of chemotherapeutic drugs for precise cancer therapy.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Micelas , Paclitaxel/administração & dosagem , Polímeros/química , Animais , Antineoplásicos Fitogênicos/farmacocinética , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Feminino , Ácido Fólico/química , Glutationa/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Ácido Hialurônico/química , Células MCF-7 , Camundongos , Terapia de Alvo Molecular , Células NIH 3T3 , Oxirredução , Paclitaxel/farmacocinética , Coelhos , Ensaios Antitumorais Modelo de Xenoenxerto , alfa-Tocoferol/química
20.
Am J Vet Res ; 81(6): 521-526, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32436789

RESUMO

OBJECTIVE: To establish a method for evaluation of the efficacy of a classical swine fever virus (CSFV) subunit vaccine in rabbits as determined via humoral immune responses to the virus. ANIMALS: 40 specific pathogen-free rabbits. PROCEDURES: Rabbits were randomly assigned to 4 groups (10 rabbits/group) for SC injection of 0.05, 0.1, and 0.2 mL of a CSFV subunit E2 vaccine (representing 1.15, 2.3, or 4.6 µg of E2 protein/dose, respectively) or saline (0.9% NaCl) solution. Blood samples were collected 21 days after vaccination for measurement of the antibody response against CSFV via ELISA and virus neutralization methods. On the same day, the CSFV Chinese (C) strain was injected into an ear vein. Vaccine efficacy was determined by monitoring of rabbits for pyrexia for 4 days and measurement of viral copies in spleen lysates at the end of the study. Reproducibility of the antibody response was tested with 2 other batches of the vaccine at the minimum immunization dose identified for the initially tested batch. RESULTS: The E2 protein dose of the initially tested vaccine was positively correlated with the antibody response and protection rate in rabbits. The identified minimum immunization dose per rabbit was 0.1 mL, representing an E2 protein content of approximately 2.3 µg, and reproducibility of the antibody response to vaccination with the 2 other batches at this dose was good. CONCLUSIONS AND CLINICAL RELEVANCE: A method was established in rabbits for evaluation of the efficacy of a CSFV subunit vaccine that could help in the optimization of later large-scale vaccine production and quality control processes as well as in the clinical application of the vaccine.


Assuntos
Vírus da Febre Suína Clássica , Peste Suína Clássica , Vacinas Virais , Animais , Anticorpos Antivirais , Coelhos , Reprodutibilidade dos Testes , Suínos , Vacinas de Subunidades , Proteínas do Envelope Viral
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