Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
World J Urol ; 42(1): 77, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38340266

RESUMO

OBJECTIVE: To assess safety, urinary symptoms, and feasibility of JJ stent removal with exteriorized threads through the percutaneous tract after percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Prospective, transversal, comparative, experimental, randomized 1-to-1 cohort study in 52 patients who underwent "tubeless" PCNL from October 2020 to November 2022. Group A with threads through the urethra and Group B through the percutaneous tract. The validated USSQ (Ureteral Stent Symptom Questionnaire) was applied in the Urology office a week after the procedure, and the JJ stent was withdrawn by pulling the threads. Hemoglobin and urine culture, and pre- and post-surgery were evaluated. RESULTS: There is a statistically significant difference in favor of group B when comparing urinary symptoms (p = 0.008), body pain (p = 0.009), and general condition (p = 0.042), mainly for non-urgency incontinence, frequency of analgesic use, and dysuria. There were significant differences between groups (p = 0.028, p = 0.026, p = 0.027, respectively). There is no association with urinary infections (p = 0.603) nor an increased risk of bleeding (p = 0.321). CONCLUSION: The removal of the JJ stent with exteriorized threads through the percutaneous tract after PCNL in the office is a feasible and safe procedure if it is removed before 8 days and has better tolerance regarding the urinary symptoms.


Assuntos
Cálculos Renais , Nefrolitotomia Percutânea , Nefrostomia Percutânea , Humanos , Nefrolitotomia Percutânea/efeitos adversos , Nefrolitotomia Percutânea/métodos , Cálculos Renais/etiologia , Nefrostomia Percutânea/métodos , Estudos de Coortes , Estudos Prospectivos , Stents/efeitos adversos , Resultado do Tratamento
2.
Mol Genet Metab ; 141(3): 108144, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38277989

RESUMO

Glycogen storage disease type Ib (GSD Ib, biallelic variants in SLC37A4) is a rare disorder of glycogen metabolism complicated by neutropenia/neutrophil dysfunction. Since 2019, the SGLT2-inhibitor empagliflozin has provided a mechanism-based treatment option for the symptoms caused by neutropenia/neutrophil dysfunction (e.g. mucosal lesions, inflammatory bowel disease). Because of the rarity of GSD Ib, the published evidence on safety and efficacy of empagliflozin is still limited and does not allow to develop evidence-based guidelines. Here, an international group of experts provides 14 best practice consensus treatment recommendations based on expert practice and review of the published evidence. We recommend to start empagliflozin in all GSD Ib individuals with clinical or laboratory signs related to neutropenia/neutrophil dysfunction with a dose of 0.3-0.4 mg/kg/d given as a single dose in the morning. Treatment can be started in an outpatient setting. The dose should be adapted to the weight and in case of inadequate clinical treatment response or side effects. We strongly recommend to pause empagliflozin immediately in case of threatening dehydration and before planned longer surgeries. Discontinuation of G-CSF therapy should be attempted in all individuals. If available, 1,5-AG should be monitored. Individuals who have previously not tolerated starches should be encouraged to make a new attempt to introduce starch in their diet after initiation of empagliflozin treatment. We advise to monitor certain safety and efficacy parameters and recommend continuous, alternatively frequent glucose measurements during the introduction of empagliflozin. We provide specific recommendations for special circumstances like pregnancy and liver transplantation.


Assuntos
Compostos Benzidrílicos , Glucosídeos , Doença de Depósito de Glicogênio Tipo I , Neutropenia , Humanos , Neutrófilos/metabolismo , Consenso , Doença de Depósito de Glicogênio Tipo I/complicações , Doença de Depósito de Glicogênio Tipo I/tratamento farmacológico , Doença de Depósito de Glicogênio Tipo I/genética , Neutropenia/tratamento farmacológico , Neutropenia/etiologia , Proteínas de Transporte de Monossacarídeos , Antiporters/metabolismo
3.
ACS Omega ; 8(27): 24601-24614, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37457461

RESUMO

A new copper(II) coordination polymer was synthesized from the l-isoleucine-Schiff base and characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, single-crystal X-ray diffraction (XRD) analysis, electronic paramagnetic resonance, and thermogravimetric analysis. XRD analysis confirmed the square planar coordination geometry of metallic centers and a zipper-like polymer structure. Vibrational, electronic, and paramagnetic spectroscopies and thermal analysis were consistent with the crystal structure. A Hirshfeld surface (HS) and density functional theory (DFT) analyses were employed to gain additional insight into interactions responsible for complex packing. The quantitative examination of two-dimensional (2D) fingerprint plots revealed, among other van der Waals forces, the dominating participation of H···H and H···Cl interactions in the molecular packing. The use of computational methods provided great help in detailing the supramolecular interactions occurring in the crystal, which were mainly van der Waals attractions. The electronic transition analysis helped corroborate the electronic transitions observed experimentally in the absorption spectrum. The frequency and vibrational mode analysis gave a deeper insight into the characterization of the CuLCL complex.

4.
JIMD Rep ; 64(3): 252-258, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37151361

RESUMO

In patients with glycogen storage disease type Ib (GSD Ib), quality of life is severely hampered by neutropenia and neutropenia-associated symptoms. SGLT2 inhibitors are a new treatment option and have shown improved medical outcomes in more than 120 patients so far. The aim of this international questionnaire study was to assess patient-reported outcomes of this new treatment in GSD Ib patients. Patients and caregivers of pediatric patients were invited to complete a web-based questionnaire. This was designed to evaluate treatment effects of the SGLT2 inhibitor empagliflozin on clinical symptoms and important aspects of daily life including physical performance, sleep, social and work life, traveling, socioeconomic aspects, and quality of life. The questionnaire was completed by 73 respondents from 17 different countries. The mean duration of treatment was 15 months, the cumulative treatment time was 94.8 years. More than 80% of patients reported an improved quality of life. The number of hospitalizations was reduced (66% of patients), as well as the number of days absent from school or work. Granulocyte colony-stimulating factor (G-CSF) treatment could be stopped in 49% of patients and reduced in another 42%. Clear improvement of neutropenia and all neutropenia-associated symptoms was reported by the majority of patients. Additionally, patients or caregivers reported positive effects on appetite (63%), level of activity (75%), overall well-being (96%), and sleep (63%). Empagliflozin positively impacts many aspects of daily life including work and social life and thereby significantly improves quality of life of patients and caregivers.

5.
Dalton Trans ; 51(46): 17671-17687, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36342366

RESUMO

Since the interfacial binding strength and structural integrity have a strong influence on the active sites of nanocomposites, this study focused on exploring the structural and electronic properties at the interface between the implanted metal ion and host support. For this, nanocomposites of gold embedded in CeO2-ZrO2 and CeO2-Al2O3 matrices were fabricated, and their structural and morphological properties were investigated using ICP-OES, UV-vis, XRD, Raman, HRTEM, and high-resolution XPS studies and compared. From the results, it was found that the deposition of gold is highly favored over CeO2-ZrO2 (3.99 atomic %) than CeO2-Al2O3 (1.21 atomic %); however, the same amount of gold was used for the synthesis of both nanocomposites, as befits it. The HRTEM images of Au/CeO2-ZrO2 displayed well-organized yarn textured particles with less than 5 nm size, which lacks in Au/CeO2-Al2O3. The reason for this less systematized and less Au embedding in the presence of alumina in CeO2-Al2O3 was verified with the high-resolution XPS studies of both nanocomposites and an elevated binding energy due to the mobility of Au particles over CeO2-Al2O3 was observed, while for Au/CeO2-ZrO2, a very small binding energy shift of gold states (Au 4f5/2 0.39; Au 4f7/2 0.17 eV) and the CeO2-ZrO2 matrix that favored an increased intermolecular force between gold and the supporting host was observed. This agrees well with UV-vis electronic spectrum analysis, which revealed that the incorporation of gold nanoparticles narrowed the band gap more significantly in Au/CeO2-ZrO2 (4.2 eV) than Au/CeO2-Al2O3 (4.94 eV) suggesting the elevated electron transfer from the conduction band of CeO2-ZrO2 to Au interfaces. In addition, XRD and Raman studies of Au/CeO2-ZrO2 showed a pronounced phase transformation of Ce4+ to Ce3+ in the presence of homovalent Zr4+ ions with an increased structural disorder in CeO2 promoting the localized surface plasmon resonance (LSPR) in the lattice of CeO2-ZrO2, which was less detected in Au/CeO2-Al2O3 due to the interference of less-desired γ-Al2O3 phases. These characteristics of Au/CeO2-ZrO2 ensured its performance as a promised photocatalyst for thioanisole degradation without using any harmful oxidants, and its stability towards different irradiation conditions, such as visible, ultraviolet, and solar light.

6.
J Am Chem Soc ; 144(24): 10743-10751, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35671395

RESUMO

Ammonia is a promising liquid-phase carrier for the storage, transport, and deployment of carbon-free energy. However, the realization of an ammonia economy is predicated on the availability of green methods for the production of ammonia powered by electricity from renewable sources or by solar energy. Here, we demonstrate the synthesis of ammonium from nitrate powered by a synergistic combination of electricity and light. We use an electrocatalyst composed of gold nanoparticles, which have dual attributes of electrochemical nitrate reduction activity and visible-light-harvesting ability due to their localized surface plasmon resonances. Plasmonic excitation of the electrocatalyst induces ammonium synthesis with up to a 15× boost in activity relative to conventional electrocatalysis. We devise a strategy to account for the effect of photothermal heating of the electrode surface, which allows the observed enhancement to be attributed to non-thermal effects such as energetic carriers and charged interfaces induced by plasmonic excitation. The synergy between electrochemical activation and plasmonic activation is the most optimal at a potential close to the onset of nitrate reduction. Plasmon-assisted electrochemistry presents an opportunity for conventional limits of electrocatalytic conversion to be surpassed due to non-equilibrium conditions generated by plasmonic excitation.

7.
Molecules ; 26(23)2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34885882

RESUMO

Two new glycine-Schiff base copper(II) complexes were synthesized. Single crystal X-ray diffraction (SCXRD) allowed us to establish the structure of both complexes in the solid state. The glycine-Schiff base copper(II) complex derived from 2'-hydroxy-5'-nitroacetophenone showed a mononuclear hydrated structure, in which the Schiff base acted as a tridentate ligand, and the glycine-Schiff base copper(II) complex derived from 2'-hydroxy-5'-methylacetophenone showed a less common tetranuclear anhydrous metallocyclic structure, in which the Schiff base acted as a tetradentate ligand. In both compounds, copper(II) had a tetracoordinated square planar geometry. The results of vibrational, electronic, and paramagnetic spectroscopies, as well as thermal analysis, were consistent with the crystal structures. Both complexes were evaluated as catalysts in the olefin cyclopropanation by carbene transference, and both led to very high diastereoselectivity (greater than 98%).


Assuntos
Aminoácidos/química , Complexos de Coordenação/química , Cobre/química , Bases de Schiff/química , Catálise , Cristalografia por Raios X , Ligantes , Modelos Moleculares
8.
Micromachines (Basel) ; 12(5)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069654

RESUMO

Micro/nanomachines (MNMs) correspond to human-made devices with motion in aqueous solutions. There are different routes for powering these devices. Light-driven MNMs are gaining increasing attention as fuel-free devices. On the other hand, Plasmonic nanoparticles (NPs) and their photocatalytic activity have shown great potential for photochemistry reactions. Here we review several photocatalyst nanosystems, with a special emphasis in Plasmon induced photocatalytic reactions, as a novel proposal to be explored by the MNMs community in order to extend the light-driven motion of MNMs harnessing the visible and near-infrared (NIR) light spectrum.

9.
World J Urol ; 39(9): 3579-3585, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33646346

RESUMO

PURPOSE: The ultrasound-guided (US) puncture in percutaneous nephrolithotomy (PCNL) has demonstrated advantages over traditional fluoroscopy access. The aim of this study was to demonstrate the reduction of fluoroscopy time using this technique during PCNL as the surgeon gained experience. METHODS: Transversal study performed on 30 consecutive patients undergoing PCNL from March to November 2019. All punctures were performed with US guidance. The patients were divided into 2 groups of 15 each according to the chronological order of the intervention. Demographic data, preoperative parameters, puncture time, fluoroscopy time, stone-free rate and complications were analyzed. RESULTS: The time of fluoroscopy was considerably reduced as the experience in the number of cases increased, reducing from 83.09 ± 47.8 s in group 1 to 22.8 ± 10.3 s in group 2 (p < 0.01), the time required to perform the puncture was reduced of 108.1 ± 68.9 s in group 1, to 92.6 ± 94.7 s in group 2 (p < 0.67). Stone free rate of 83.3% was obtained globally. CONCLUSION: US percutaneous renal access is safe and reproducible technique; the main advantage is to reduce exposure to radiation without compromising clinical results and has a short learning curve for urologists with prior experience in PCNL.


Assuntos
Fluoroscopia/métodos , Nefrolitotomia Percutânea/métodos , Punções/métodos , Radiação Ionizante , Cirurgia Assistida por Computador , Ultrassonografia de Intervenção , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
10.
Molecules ; 25(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233564

RESUMO

Doxorubicin (Dox) is the most widely used chemotherapeutic agent and is considered a highly powerful and broad-spectrum for cancer treatment. However, its application is compromised by the cumulative side effect of dose-dependent cardiotoxicity. Because of this, targeted drug delivery systems (DDS) are currently being explored in an attempt to reduce Dox systemic side-effects. In this study, DDS targeting hepatocellular carcinoma (HCC) has been designed, specifically to the asialoglycoprotein receptor (ASGPR). Dox-loaded albumin-albumin/lactosylated (core-shell) nanoparticles (tBSA/BSALac NPs) with low (LC) and high (HC) crosslink using glutaraldehyde were synthesized. Nanoparticles presented spherical shapes with a size distribution of 257 ± 14 nm and 254 ± 14 nm, as well as an estimated surface charge of -28.0 ± 0.1 mV and -26.0 ± 0.2 mV, respectively. The encapsulation efficiency of Dox for the two types of nanoparticles was higher than 80%. The in vitro drug release results showed a sustained and controlled release profile. Additionally, the nanoparticles were revealed to be biocompatible with red blood cells (RBCs) and human liver cancer cells (HepG2 cells). In cytotoxicity assays, Dox-loaded nanoparticles decrease cell viability more efficiently than free Dox. Specific biorecognition assays confirmed the interaction between nanoparticles and HepG2 cells, especially with ASGPRs. Both types of nanoparticles may be possible DDS specifically targeting HCC, thus reducing side effects, mainly cardiotoxicity. Therefore, improving the quality of life from patients during chemotherapy.


Assuntos
Albuminas/química , Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Lactose/química , Nanopartículas/química , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Preparações de Ação Retardada , Modelos Animais de Doenças , Liberação Controlada de Fármacos , Eritrócitos/efeitos dos fármacos , Hemólise , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Tamanho da Partícula
11.
PeerJ ; 8: e8956, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32341898

RESUMO

Synthetic molecules that mimic the function of natural enzymes or molecules have untapped potential for use in the next generation of drugs. Cyclic compounds that contain aromatic rings are macrocyclic cyclophanes, and when they coordinate iron ions are of particular interest due to their antioxidant and biomimetic properties. However, little is known about the molecular responses at the cellular level. This study aims to evaluate the changes in immune gene expression in human cells exposed to the cyclophanes Fe2PO and Fe2PC. Confluent human embryonic kidney cells were exposed to either the cyclophane Fe2PO or Fe2PC before extraction of RNA. The expression of a panel of innate and adaptive immune genes was analyzed by quantitative real-time PCR. Evidence was found for an inflammatory response elicited by the cyclophane exposures. After 8 h of exposure, the cells increased the relative expression of inflammatory mediators such as interleukin 1; IRAK, which transduces signals between interleukin 1 receptors and the NFκB pathway; and the LPS pattern recognition receptor CD14. After 24 h of exposure, regulatory genes begin to counter the inflammation, as some genes involved in oxidative stress, apoptosis and non-inflammatory immune responses come into play. Both Fe2PO and Fe2PC induced similar immunogenetic changes in transcription profiles, but equal molar doses of Fe2PC resulted in more robust responses. These data suggest that further work in whole animal models may provide more insights into the extent of systemic physiological changes induced by these cyclophanes.

12.
Molecules ; 24(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581425

RESUMO

The Cu2+, Mn2+, and Fe3+ complexes of a 14 membered macrocycle were synthesized and their antioxidant capacities were evaluated against ABTS and DPPH radicals, with the objective of collecting insights into the biomimetic role of the central metal ions. The macrocycle, abbreviated as H2L14, is a derivative of EDTA cyclized with 1,4-diamine, and the moderately flexible macrocyclic frame permits the formation of [ML14·H2O] chelates with octahedral coordination geometries common among the metal ions. The metal complexes were characterized by electrospray-ionization mass spectrometry, Fourier transform infrared spectroscopy, and Raman and X-ray photoelectron spectroscopic methods, as well as thermogravimetric analysis; the octahedral coordination geometries with water coordination were optimized by DFT calculations. The antioxidant assays showed that [FeL14·H2O]+ was able to scavenge synthetic radicals with moderate capacity, whereas the other metal chelates did not show significant activity. The Raman spectrum of DPPH in solution suggests that interaction was operative between the Fe3+ chelate and the radical so as to cause scavenging capability. The nature of the central metal ions is a controlling factor for antioxidant capacity, as every metal chelate carries the same coordination geometry.


Assuntos
Antioxidantes/síntese química , Complexos de Coordenação/síntese química , Ácido Edético/química , Compostos Macrocíclicos/síntese química , Antioxidantes/química , Complexos de Coordenação/química , Cobre/química , Teoria da Densidade Funcional , Ferro/química , Compostos Macrocíclicos/química , Manganês/química , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
13.
Nanoscale ; 11(6): 2829-2839, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30676594

RESUMO

Herein, a series of N-doped carbon nanotube (CNx) samples were obtained by modifying the synthesis temperature. Consequently, the proportion of graphitic nitrogen (Ngraph) in the samples was systematically increased as a function of temperature. This allowed evaluation of the role of the CNx graphitic nitrogen in the oxygen reduction reaction (ORR). A correlation between the Ngraph content and the ORR onset potential was observed, which shifted to more positive potentials with an increase in kinetic current density (jk); this showed that Ngraph played a significant catalytic role in the ORR. The samples with high Ngraph content favored the two-electron pathway for the ORR not only in basic media (pH = 13) but also in neutral media (pH = 7), representing an attractive alternative for wastewater remediation through the on-site generation of H2O2. The energetic calculations showed that the formation of H2O2 must be favorable in the presence of graphitic nitrogen sites. Finally, the performance of the buckypaper arrangement was evaluated, and the CNx buckypaper showed a higher cathodic current peak as compared to CNx traditional ink dispersions. Overall, this study not only sheds light on the role of Ngraph in the ORR, but also demonstrates that CNx buckypaper is an efficient 3D electrode for electrocatalytic applications.

14.
ACS Omega ; 4(27): 22487-22496, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31909331

RESUMO

With the objective of studying the conformational and macrocyclic effects of selected metal chelates on their peroxidase activities, Cu2+ and Fe3+ complexes were synthesized with a macrocyclic derivative of ethylenediaminetetraacetic acid and o-phenylenediamine (abbreviated as edtaodH2) and its new open-chain analogue (edtabzH2). The Fe3+ complex of edtaodH2 has a peroxidase-like activity, whereas the complex of edtabzH2 does not. The X-ray study of the former shows the formation of a dimeric molecule {[Fe(edtaod)]2O} in which each metal with an octahedral coordination is overposed over the macrocyclic cavity, as a result of rigid macrocyclic frame, to form an Fe-O-Fe bridge; the exposure of the central metal to the environment facilitates the capture of oxygen to drive the biomimetic activity. The peroxidase-inactive Fe3+ complex consists of a mononuclear complex ion [Fe(edtabz)(H2O)]+, the metal ion of which is suited in a distorted pentagonal bipyramid to be protected from environmental oxygen. The copper(II) complexes, which have mononuclear structures with high thermodynamic stability compared with the iron(III) complexes, show no peroxidase activity. The steric effects play a fundamental role in the biomimetic activity.

15.
J Bioenerg Biomembr ; 47(5): 431-40, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26315341

RESUMO

Nucleotide phosphorylation is a key step in DNA replication and viral infections, since suitable levels of nucleotide triphosphates pool are required for this process. Deoxythymidine monophosphate (dTMP) is produced either by de novo or salvage pathways, which is further phosphorylated to deoxythymidine triphosphate (dTTP). Thymidyne monophosphate kinase (TMK) is the enzyme in the junction of both pathways, which phosphorylates dTMP to yield deoxythymidine diphosphate (dTDP) using adenosine triphosphate (ATP) as a phosphate donor. White spot syndrome virus (WSSV) genome contains an open reading frame (ORF454) that encodes a thymidine kinase and TMK domains in a single polypeptide. We overexpressed the TMK ORF454 domain (TMKwssv) and its specific activity was measured with dTMP and dTDP as phosphate acceptors. We found that TMKwssv can phosphorylate dTMP to yield dTDP and also is able to use dTDP as a substrate to produce dTTP. Kinetic parameters K M and k cat were calculated for dTMP (110 µM, 3.6 s(-1)), dTDP (251 µM, 0.9 s(-1)) and ATP (92 µM, 3.2 s(-1)) substrates, and TMKwssv showed a sequential ordered bi-bi reaction mechanism. The binding constants K d for dTMP (1.9 µM) and dTDP (10 µM) to TMKwssv were determined by Isothermal Titration Calorimetry. The affinity of the nucleotidic analog stavudine monophosphate was in the same order of magnitude (K d 3.6 µM) to the canonical substrate dTMP. These results suggest that nucleotide analogues such as stavudine could be a suitable antiviral strategy for the WSSV-associated disease.


Assuntos
Núcleosídeo-Fosfato Quinase/química , Fases de Leitura Aberta , Proteínas Virais/química , Vírus da Síndrome da Mancha Branca 1/enzimologia , Núcleosídeo-Fosfato Quinase/antagonistas & inibidores , Núcleosídeo-Fosfato Quinase/genética , Estrutura Terciária de Proteína , Especificidade por Substrato/fisiologia , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/genética , Vírus da Síndrome da Mancha Branca 1/genética
16.
Mem Inst Oswaldo Cruz ; 108(5): 616-22, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23903978

RESUMO

The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Giardia lamblia/imunologia , Proteínas de Protozoários/imunologia , Animais , Western Blotting , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Giardíase/imunologia , Giardíase/parasitologia , Camundongos
17.
Mem. Inst. Oswaldo Cruz ; 108(5): 616-622, ago. 2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-680767

RESUMO

The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.


Assuntos
Animais , Camundongos , Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Giardia lamblia/imunologia , Proteínas de Protozoários/imunologia , Western Blotting , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Giardíase/imunologia , Giardíase/parasitologia
18.
J Bioenerg Biomembr ; 45(6): 511-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23873077

RESUMO

Arginine kinase (AK) is a key enzyme for energetic balance in invertebrates. Although AK is a well-studied system that provides fast energy to invertebrates using the phosphagen phospho-arginine, the structural details on the AK-arginine binary complex interaction remain unclear. Herein, we determined two crystal structures of the Pacific whiteleg shrimp (Litopenaeus vannamei) arginine kinase, one in binary complex with arginine (LvAK-Arg) and a ternary transition state analog complex (TSAC). We found that the arginine guanidinium group makes ionic contacts with Glu225, Cys271 and a network of ordered water molecules. On the zwitterionic side of the amino acid, the backbone amide nitrogens of Gly64 and Val65 coordinate the arginine carboxylate. Glu314, one of proposed acid-base catalytic residues, did not interact with arginine in the binary complex. This residue is located in the flexible loop 310-320 that covers the active site and only stabilizes in the LvAK-TSAC. This is the first binary complex crystal structure of a guanidine kinase in complex with the guanidine substrate and could give insights into the nature of the early steps of phosphagen biosynthesis.


Assuntos
Arginina Quinase/química , Arginina/química , Penaeidae/enzimologia , Animais , Arginina/metabolismo , Arginina Quinase/metabolismo , Cristalografia por Raios X , Modelos Moleculares , Conformação Proteica , Especificidade por Substrato
19.
Molecules ; 18(2): 1762-74, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23434862

RESUMO

The cyclophanes 2,9,25,32-tetraoxo-4,7,27,30-tetrakis(carboxymethyl)-1,4,7,10, 24,27,30,33-octaaza-17,40-dioxa[10.1.10.1]paracyclophane (PO) and 2,9,25,32-tetraoxo-4,7,27,30-tetrakis(carboxymethyl)-1,4,7,10,24,27,30,33-octaaza[10.1.10.1]paracyclophane (PC) were coordinated with iron to form cationic binuclear Fe(III) Fe2PO and Fe2PC complexes, respectively. Their antioxidant capacity, superoxide dismutase and peroxidase mimetic activity, as well as their toxicity toward peripheral blood mononuclear cells (PBMCs) were evaluated. Both Fe2PO and Fe2PC are interesting biomimetics with antioxidant capacity similar to that of ascorbic acid that prevent mortality in cultured PBMCs, with the potential to have bioactive and protective functions in disease animal models.


Assuntos
Antioxidantes/farmacologia , Complexos de Coordenação/farmacologia , Éteres Cíclicos/farmacologia , Ferro/farmacologia , Absorção , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Citoproteção/efeitos dos fármacos , Espectroscopia de Ressonância de Spin Eletrônica , Elétrons , Éteres Cíclicos/síntese química , Éteres Cíclicos/química , Humanos , Concentração de Íons de Hidrogênio , Ferro/química , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Espectrometria de Massas , Oxirredução/efeitos dos fármacos , Peroxidase/metabolismo , Prótons , Espectrofotometria Infravermelho , Superóxido Dismutase/metabolismo
20.
J Bioenerg Biomembr ; 44(3): 325-31, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22528393

RESUMO

Biosynthesis of nucleoside triphosphates is critical for bioenergetics and nucleic acid replication, and this is achieved by nucleoside diphosphate kinase (NDK). As an emerging biological model and the global importance of shrimp culture, we have addressed the study of the Pacific whiteleg shrimp (Litopenaeus vannamei) NDK. We demonstrated its activity and affinity towards deoxynucleoside diphosphates. Also, the quaternary structure obtained by gel filtration chromatography showed that shrimp NDK is a trimer. Affinity was in the micro-molar range for dADP, dGDP, dTDP and except for dCDP, which presented no detectable interaction by isothermal titration calorimetry, as described previously for Plasmodium falciparum NDK. This information is particularly important, as this enzyme could be used to test nucleotide analogs that can block white spot syndrome virus (WSSV) viral replication and to study its bioenergetics role during hypoxia and fasting.


Assuntos
Nucleosídeo NM23 Difosfato Quinases/metabolismo , Animais , Domínio Catalítico , Modelos Moleculares , Nucleosídeo NM23 Difosfato Quinases/química , Nucleosídeo NM23 Difosfato Quinases/genética , Proteínas Oncogênicas/química , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Frutos do Mar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...