Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
J Trace Elem Med Biol ; 81: 127349, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38006813

RESUMO

BACKGROUND: Doping was reported to improve the photo catalytic performance, antioxidant, antibacterial and other biological properties of nanoparticles. While, improving the nanoparticle properties, doping could change toxicity profile to living organism. Hence, the aim of this work was to assess the effects of samarium doped zinc oxide nanoparticles (Sm doped ZnO NPs) on the edible mussel Mytilus galloprovincialis. METHODS: Sm doped ZnO nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) techniques. 156 mussels were exposed during 7 days to a low, intermediate and high concentration of Sm doped ZnO NPs (0.5, 1 and 1.5 mg/L, respectively). The filtration rates were assessed after 1 and 2 h. Histopathological alterations were determined in gills, digestive glands and gonads using a quantitative analysis. RESULTS: The filtration rates decreased in all individuals exposed to Sm doped ZnO NPs, a significant decrease was noted with the low and intermediate concentration (0.5 and 1 mg/L) of Sm doped ZnO NPs after 1 and 2 h, respectively. The histopathological index (Ih) estimated for gills, digestive glands and gonads showed differences depending on the organ and the nanoparticle concentration. The highest Ih were reported for digestive glands and female gonads exposed to the intermediate concentration (1 mg/L) of Sm doped ZnO NPs. As for gills and male gonads, the highest Ih were noted with the high concentration (1.5 mg/L) of Sm doped ZnO NPs. CONCLUSION: Results from this study revealed the toxicity of Sm doped ZnO NPs in Mytilus galloprovincialis gills, digestive glands and gonads. The toxicity induced by this nanoparticle varies depending on the organ and the concentration.


Assuntos
Nanopartículas Metálicas , Metais Terras Raras , Mytilus , Nanopartículas , Óxido de Zinco , Animais , Feminino , Masculino , Humanos , Zinco/farmacologia , Óxido de Zinco/farmacologia , Samário/farmacologia , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
2.
Sci Rep ; 13(1): 8252, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37217773

RESUMO

This work was conducted to study positive and negative impacts of cerium (Ce) and samarium (Sm) on two cultivars (Arta and Baharan) in wheat plant. Symbols of stress such as proline, malondialdehyde (MDA) and antioxidant enzymes, which may be complicated in the suppression responses of plants, were also studied. Wheat plants were exposed to 0, 2500, 5000, 7500, 10,000 and 15,000 µM of Ce and Sm for 7 days. The growth enhanced in plants treated with lesser Ce and Sm concentration (2500 µM) and declined in plants treated with upper concentrations as compared to untreated plants. The treatment with 2500 µM of Ce and Sm increased dry weigh in Arta by 68.42 and 20% and in Baharan by 32.14% and 27.3%. Thus, Ce and Sm had hormesis effect on growth in wheat plants. According to plant's growth parameter patterns, Arta cultivar had more sensitive to Sm than to Ce, whereas Baharan cultivar had sensitive to Ce than to Sm. Our results indicated impact of Ce and Sm on proline accumulation depended on the dosage of Ce and Sm. It was observed that Ce and Sm accumulated in wheat plants at higher exposure doses. Increment of MDA content by Ce and Sm treatments showed that these metals caused oxidative stress in wheat plants. Ce and Sm blocked enzymatic antioxidant system (superoxide dismutases, peroxidase and polyphenol peroxidase) in wheat. In wheat plants treated with lower Ce and Sm concentrations higher amounts of non-enzymatic antioxidant metabolites were detected. Thus, we showed the potential negative impact of unsuitable utilization of REEs in plants and suggested growth and interruption in physiological and biochemical mechanisms as a possible factor to recognize the underlying toxicological processes.


Assuntos
Antioxidantes , Cério , Antioxidantes/metabolismo , Triticum/metabolismo , Samário/metabolismo , Samário/farmacologia , Cério/farmacologia , Peroxidase/metabolismo , Plantas/metabolismo , Prolina/metabolismo
3.
Inorg Chem ; 61(6): 2768-2782, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35099955

RESUMO

Trivalent europium-based monochromatic red light-emitting phosphors are an essential component to realize high-performance smart lighting devices; however, the concentration and thermal quenching restrict their usage. Here, we report a series of efficient Eu3+-substituted Li3Y3BaSr(MoO4)8 red-emitting phosphors based on a stratified scheelite structure with negligible concentration and thermal quenching. All of the host and phosphor compositions crystallize in monoclinic crystal structure (space group C2/c). All of the phosphor compositions produce narrow-band red emission (FWHM ∼6 nm), which is highly apparent to the human eyes, and lead to exceptional chromatic saturation of the red spectral window. Concurrently, detailed investigations were carried out to comprehend the concentration and thermal quenching mechanism. Absolute quantum yields as high as 88.5% were obtained for Li3Y0.3Eu2.7BaSr(MoO4)8 phosphor with virtuous thermal stability (at 400 K, retaining 87% of its emission intensity). The light-emitting diodes were constructed by coupling Li3BaSrY0.3Eu2.7(MoO4)8 red phosphor with a near-UV LED chip (395 nm) operated at 20 mA forward bias, and the hybrid white LED (an organic yellow dye + red Li3Y3BaSr(MoO4)8:Eu3+ phosphor integrated with an NUV LED chip) showed a low CCT (6645 K), high CRI (83) values, and CIE values of x = 0.303; y = 0.368, which indicated that the synthesized phosphors can be a suitable red component for white LEDs. In addition, we have systematically investigated the Sm3+ and Sm3+, Eu3+ activation in Li3Y3BaSr(MoO4)8 to display the latent use of the system in plant growth applications and establish that the phosphor exhibits orange red emission with an intense deep-red emission (645 nm (4G5/2 → 6H9/2)). The phytochrome (Pr) absorption spectrum well matched the fabricated deep-red LED (by integrating a NUV LED + Li3Y3BaSr(MoO4)8:Sm3+ and Eu3+ phosphor) spectral lines.


Assuntos
Cor , Luz , Substâncias Luminescentes/farmacologia , Plantas/efeitos dos fármacos , Bário/química , Bário/farmacologia , Európio/química , Európio/farmacologia , Humanos , Lítio/química , Lítio/farmacologia , Substâncias Luminescentes/química , Medições Luminescentes , Molibdênio/química , Molibdênio/farmacologia , Fósforo/química , Fósforo/farmacologia , Samário/química , Samário/farmacologia , Estrôncio/química , Estrôncio/farmacologia , Temperatura
4.
J Fluoresc ; 32(2): 613-627, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35020114

RESUMO

Six crimson samarium (III) complexes based on ß-ketone carboxylic acid and ancillary ligands were synthesized by adopting the grinding technique. All synthesized complexes were investigated via elemental analysis, infrared, UV-Vis, NMR, TG/DTG and photoluminescence studies. Optical properties of these photostimulated samarium (III) complexes exhibit reddish-orange luminescence due to 4G5/2 → 6H7/2 electronic transition at 606 nm of samarium (III) ions. Further, energy bandgap, color purity, CIE color coordinates, CCT and quantum yield of all complexes were determined accurately. Replacement of water molecules by ancillary ligands enriched these complexes (S2-S6) with decay time, quantum yield, luminescence, energy bandgap and biological properties than parent complex (S1). Interestingly, these efficient properties of complexes may find their applications in optoelectronics and lighting systems. In addition to these, the antioxidant and antimicrobial assays were also investigated to explore the applications in biological assays.


Assuntos
Complexos de Coordenação/síntese química , Equipamentos e Provisões , Luminescência , Dispositivos Ópticos , Samário/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Colorimetria , Complexos de Coordenação/química , Análise Diferencial Térmica , Transferência de Energia , Samário/farmacologia , Análise Espectral
5.
Tumour Biol ; 42(3): 1010428320909999, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32129155

RESUMO

Cancer is the leading cause of death and exhausts human and economic resources for treatment and protection. Zinc oxide nanoparticles play an effective role in tumor treatment but with some cautions, such as overexpression of cytochrome P450, hepatic overload, and the mammalian target of rapamycin pathway resistance. Although lanthanides have antitumor activity, their use is limited. Therefore, the current study aims to improve the effectiveness of zinc oxide nanoparticle via doping with lanthanides, such as samarium. In vitro study revealed that samarium doped with zinc oxide showed more antitumor activity than the other lanthanides, and the antitumor activity depends on the concentration of samarium in the nanocomposite. The in vivo experiment on mice bearing Ehrlich solid tumor revealed that intramuscular injection of samarium/zinc oxide downregulates the expressions of CXCR4 and PI3K/Akt/mammalian target of rapamycin pathway in respect to Ehrlich solid tumor group. Regarding the apoptotic biomarkers, samarium/zinc oxide upregulates the apoptotic biomarker; Bax accompanied with the mitotic catastrophe which was indicated by cell cycle arrest in G2 phase. Moreover, samarium:zinc oxide nanoparticles exhibited minimum toxicity which was indicated by suppressed activities of cytochrome P450 and hepatic enzymes, including alanine transaminase and aspartate transaminase. In addition, the histopathological finding, as well as immunophenotyping results, appreciated the biochemical finding. Therefore, samarium:zinc oxide might be offered a new approach to improve the effectiveness of zinc oxide nanoparticles along with lower toxic effect. Also, samarium:zinc oxide nanoparticles can be a candidate as a new antitumor compound to detect its mode of action.


Assuntos
Antineoplásicos/farmacologia , Inibidores das Enzimas do Citocromo P-450/farmacologia , Receptores CXCR4/antagonistas & inibidores , Samário/farmacologia , Óxido de Zinco/farmacologia , Animais , Regulação para Baixo , Feminino , Camundongos , Nanopartículas , Receptores CXCR4/genética , Samário/efeitos adversos , Óxido de Zinco/efeitos adversos
6.
Mater Sci Eng C Mater Biol Appl ; 99: 1257-1273, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889661

RESUMO

Lithium (Li+) ion due to its excellent bioactivity is one of the most well-studied element in bone-tissue engineering. In this study, we fabricated nanohydroxyapatite (nHAp) doped with Li+ ions (5 mol% Li+:nHAp) and co-doped with lanthanide ions. We investigated the effects of nHAp, 5 mol% Li+:nHAp or Li+ alone, on osteogenic differentiation of human Adipose Tissue-derived Stem Cells (hASCs), their proliferation, mitochondrial dynamics and apoptosis. Moreover, we monitored cell proliferation after treatment with samarium (III) (Sm3+) and europium (III) (Eu3+) ions co-doped 5 mol% Li+:nHAp as well as their luminescent property. The hASCs treated with 5 mol% Li+:nHAp and Li+ ions proliferated more rapidly and differentiated effectively than control cells without undergoing apoptosis. Both, 5 mol% Li+:nHAp and Li+ ions improved osteogenic differentiation of hASCs. Moreover they decreased expression of glycogen synthase kinase 3ß (GSK3ß) while increased ß-catenin mRNA level. In addition, Li+, nHAp and 5 mol% Li+:nHAp improved mitochondrial dynamics and enhanced expression of neural differentiation marker genes. Collectively, the study indicates on pro-osteogenic and anti-apoptotic properties of nHAp doped with Li+ and Li+ alone. Moreover, unique properties of 5 mol% Li+:nHAp and 5 mol% Li+:nHAp co-doped with rare earth ions, such as Sm3+ and Eu3+ have shed a promising light on their potential application in theranostics.


Assuntos
Durapatita/química , Európio/farmacologia , Lítio/farmacologia , Células-Tronco Mesenquimais/metabolismo , Nanopartículas/química , Osteogênese/efeitos dos fármacos , Samário/farmacologia , Nanomedicina Teranóstica , Apoptose , Biomarcadores/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Humanos , Íons , Leptina/genética , Leptina/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , MicroRNAs/genética , MicroRNAs/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Nanopartículas/ultraestrutura , Nestina/genética , Nestina/metabolismo , Proteínas de Neurofilamentos/genética , Proteínas de Neurofilamentos/metabolismo , Osteogênese/genética , Osteopontina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
7.
Adv Biosyst ; 3(2): e1800241, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-32627378

RESUMO

Engineering functional nanomaterials to have both high therapeutic efficacy and minimal side-effects has become a promising strategy for next-generation cancer treatments. Herein, an adenosine triphosphate (ATP) depletion and reactive oxygen species-enhanced combination chemotherapy platform is introduced whereby therapeutic samarium (Sm3+ ) ions and (-)-epicatechin (EC) are integrated via a metal-phenolic network (SmIII -EC). The independent pathway between Sm3+ and EC can achieve a synergistic therapeutic effect through the mitochondrial dysfunction process. SmIII -EC nanoparticles cause a significant reduction of viability of C26 murine colon carcinoma cells while with lower systemic toxic effects on normal cell lines. SmIII -EC nanoparticles are used to directly compare with a clinic anticancer drug 5-fluorouracil. SmIII -EC nanoparticles not only decrease the tumor volume but also do not affect the body weight of mice and normal organs, showing significant advantages over clinic counterpart. These facts suggest that SmIII -EC nanoparticles represent a clinically promising candidate for colon cancer treatment with a targeted therapeutic effect and minimum side toxicity.


Assuntos
Antineoplásicos , Catequina , Neoplasias do Colo/metabolismo , Nanopartículas Metálicas/química , Samário , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Catequina/química , Catequina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Fenóis , Samário/química , Samário/farmacologia
8.
Parasitol Res ; 117(5): 1409-1417, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29532220

RESUMO

This work investigated the anti-amoebic activity of two samarium (Sm) complexes, the acyclic complex [bis(picrato)(pentaethylene glycol)samarium(III)] picrate-referred to as [Sm(Pic)2(EO5)](Pic)-and the cyclic complex [bis(picrato)(18-crown-6)samarium(III)] picrate-referred to as [Sm(Pic)2(18C6)](Pic). Both Sm complexes caused morphological transformation of the protozoa Acanthamoeba from its native trophozoite form carrying a spine-like structure called acanthopodia, to round-shaped cells with loss of the acanthopodia structure, a trademark response to environmental stress. Further investigation, however, revealed that the two forms of the Sm complexes exerted unique cytotoxicity characteristics. Firstly, the IC50 of the acyclic complex (0.7 µg/mL) was ~ 10-fold lower than IC50 of the cyclic Sm complex (6.5 µg/mL). Secondly, treatment of the Acanthamoeba with the acyclic complex caused apoptosis of the treated cells, while the treatment with the cyclic complex caused necrosis evident by the leakage of the cell membrane. Both treatments induced DNA damage in Acanthamoeba. Finally, a molecular docking simulation revealed the potential capability of the acyclic complex to form hydrogen bonds with profilin-a membrane protein present in eukaryotes, including Acanthamoeba, that plays important roles in the formation and degradation of actin cytoskeleton. Not found for the cyclic complex, such potential interactions could be the underlying reason, at least in part, for the much higher cytotoxicity of the acyclic complex and also possibly, for the observed differences in the cytotoxicity traits. Nonetheless, with IC50 values of < 10 µg/mL, both the acyclic and cyclic Sm complexes feature a promising potential as cytotoxic agents to fight amoebic infections.


Assuntos
Acanthamoeba/efeitos dos fármacos , Amebicidas/farmacologia , Apoptose/efeitos dos fármacos , Membrana Celular/patologia , Dano ao DNA/efeitos dos fármacos , Samário/química , Samário/farmacologia , Ceratite por Acanthamoeba/tratamento farmacológico , Ceratite por Acanthamoeba/parasitologia , Animais , Simulação de Acoplamento Molecular , Trofozoítos/efeitos dos fármacos
9.
Support Care Cancer ; 26(3): 751-758, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28920149

RESUMO

PURPOSE: The purpose of this study is to assess the efficacy of 153Sm-EDTMP (Quadramet®) in a clinical setting. METHODS: We have conducted a retrospective study of all consecutive patients (pts) treated with 153Sm-EDTMP for painful bone metastases. At each visit (before and after treatment), four parameters were collected: (i) pain assessment according to the 10-step visual analogue scale (VAS), (ii) sleep disturbance related to pain, (iii) dose of analgesic medication, and (iv) answer to the following closed question "Do you think you obtained a benefit from treatment?" Success of treatment was defined by the combination of these four parameters. RESULTS: Three hundred seventy consecutive 153Sm-EDTMP treatments for painful bone metastases were given. Patients had the following primary tumors: breast carcinoma (153), prostate carcinoma (155), lung carcinoma (27), or other cancers (35). Fifty-eight percent of the patients had received previous external osseous radiotherapy. Ninety-seven percent of the patients were treated with concomitant analgesics and 61% were treated with diphosphonates. A clinical benefit was described in 55.0% of cases at D30. Treatment was more effective in cases of breast and prostate cancers compared with other types of primary cancers. Patients described a benefit at D30 in 62, 58, 6, and 38% of cases of breast, prostate, lung, and other cancers. The subjective efficacy was accompanied by a decrease in analgesic intake in 35.0% of cases. CONCLUSION: 153Sm-EDTMP therapy is an effective supportive treatment in patients who suffer from bone metastases, especially in patients with breast or prostate cancer.


Assuntos
Neoplasias Ósseas/secundário , Dor/tratamento farmacológico , Radioisótopos/uso terapêutico , Samário/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioisótopos/farmacologia , Estudos Retrospectivos , Samário/farmacologia , Resultado do Tratamento
10.
J Colloid Interface Sci ; 466: 1-11, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26692538

RESUMO

Ln-based complexes can be used as T1-enhanced contrast agents of magnetic resonance (MR) imaging in clinical field. Herein, we present a facile and feasible biomineralization process to fabricate Gd/Eu-codoped SmPO4 nanorods (NRs) with silk fibroin (SF) peptides (codoped SF-NRs) as T1-enhanced contrast agents, which possess paramagnetic property, photoluminescence (PL), better cyto-/tissue-compatibility and longer half-life in blood due to SF coating on their surface. Their bio-distributions in TB-N mice via tail-vein injection indicated that, although SF-NRs could be safely cleared away through renal and fecal excretion, SF-NRs easily permeated and aggregated in tumors. The results of in vitro MR imaging demonstrate that the longitudinal relaxivity r1 value of codoped SF-NRs (0.31 Sm-Gd mM(-1) s(-1)) is not only significantly higher than those of Gd-doped and Eu-doped SmPO4 SF-NRs, but also higher than those of codoped pure NRs. The tests of in vivo T1 weighted MR imaging via intro-tumor injection and tail-vein injection confirm that, compared to the pure NRs, the codoped SF-NRs exhibited higher positive signal-enhancement ability. Furthermore, the better luminescence imaging of living cells under the fluorescence microscope (94% stronger than that of the NRs without SF). A formation mechanism of codoped SF-NRs is proposed, to explain the synergistic effect of Gd/Eu codoping and SF coating on their enhanced bio-compatibility, half-life in blood, T1-weighted MR imaging and PL imaging.


Assuntos
Meios de Contraste/química , Európio/química , Gadolínio/química , Imageamento por Ressonância Magnética , Nanotubos/química , Imagem Óptica , Fosfatos/química , Samário/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Európio/farmacologia , Fibroínas/química , Gadolínio/farmacologia , Células Hep G2 , Humanos , Luminescência , Camundongos , Camundongos Nus , Neoplasias Experimentais/diagnóstico , Tamanho da Partícula , Peptídeos/química , Fosfatos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Samário/farmacologia , Seda/química , Propriedades de Superfície
11.
Artigo em Inglês | MEDLINE | ID: mdl-25579799

RESUMO

Trivalent lanthanide complexes of the type [Ln(L)Cl(H2O)2] (where Ln=Nd(III) or Sm(III) and LH2=Schiff bases derived by the condensation of 3-(phenyl/substitutedphenyl)-4-amino-5-mercapto-1,2,4-triazole with diacetyl/benzil) have been synthesized by the reactions of anhydrous lanthanide(III) chloride with Schiff bases in methanol. The structures of the complexes have been proposed on the basis of elemental analysis, electrical conductance, magnetic moment, spectroscopic measurements (IR, 1H, 13C NMR and UV-vis spectra) and X-ray diffraction studies. The spectral data reveal that the Schiff base ligands behave as dibasic tetradentate chelating agents having coordination sites at two thiol sulfur atoms and two azomethine nitrogen atoms. The presence of coordinated water in metal complexes was confirmed by thermal and IR data of the complexes. All the Schiff bases and their metal complexes have also been screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus and antifungal activities against Aspergillus niger, Curvularia pallescens and Colletotrichum capsici.


Assuntos
Antibacterianos/química , Antifúngicos/química , Complexos de Coordenação/química , Neodímio/química , Samário/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Fungos/efeitos dos fármacos , Humanos , Ligantes , Testes de Sensibilidade Microbiana , Micoses/tratamento farmacológico , Neodímio/farmacologia , Samário/farmacologia , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Análise Espectral , Temperatura , Triazóis/síntese química , Triazóis/química , Triazóis/farmacologia
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 131: 388-97, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24835942

RESUMO

The complexes of Sm(III) and Tb(III) with 2-aminobenzoic acid (anthranilic acid, AA) and 2-amino-5-chlorobenzoic acid (5-chloroanthranilic acid, AACl) were synthesized and characterized based on elemental analysis, IR and mass spectroscopy. The data are in accordance with 1:3 [Metal]:[Ligand] ratio. On the basis of the IR analysis, it was found that the metals were coordinated to bidentate anthranilic acid via the ionised oxygen of the carboxylate group and to the nitrogen of amino group. While in 5-chloroanthranilic acid, the metals were coordinated oxidatively to the bidentate carboxylate group without bonding to amino group; accordingly, a chlorine-affected coordination and reactivity-diversity was emphasized. Thermal analyses (TGA) and biological activity of the complexes were also investigated. Density Functional Theory (DFT) calculations at the B3LYP/6-311++G (d,p)_ level of theory have been carried out to investigate the equilibrium geometry of the ligand. The optimized geometry parameters of the complexes were evaluated using SDDALL basis set. Moreover, total energy, energy of HOMO and LUMO and Mullikan atomic charges were calculated. In addition, dipole moment and orientation have been performed and discussed.


Assuntos
Anti-Infecciosos/química , Complexos de Coordenação/química , Samário/química , Térbio/química , ortoaminobenzoatos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Complexos de Coordenação/farmacologia , Fungos/efeitos dos fármacos , Halogenação , Humanos , Modelos Moleculares , Micoses/tratamento farmacológico , Teoria Quântica , Samário/farmacologia , Térbio/farmacologia , ortoaminobenzoatos/farmacologia
13.
Nat Prod Commun ; 8(7): 889-96, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23980417

RESUMO

A simple and straightforward synthetic approach was developed to access a biologically important class of alpha-aminomethyl-gamma-butyrolactones via a beta-lactam synthon strategy involving successive ring-opening and lactonization processes from alpha-hydroxyethyl-substituted beta-lactams that were elaborated by SmI2-mediated reductive coupling reaction.


Assuntos
Lactonas/síntese química , beta-Lactamas/química , 4-Butirolactona/análogos & derivados , Iodetos/farmacologia , Lactonas/química , Espectroscopia de Ressonância Magnética , Oxirredução , Samário/farmacologia
14.
PLoS One ; 8(2): e57432, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23451229

RESUMO

Currently, there are no versatile and established methods for improving stability of proteins. In an entirely different approach from conventional techniques such as mutagenesis, we attempted to enhance enzyme stability of α-amylase from Aspergillus oryzae using a heavy-atom derivatization technique. We evaluated changes in stability using differential scanning calorimetry (DSC). Candidate heavy atoms were identified using the Heavy-Atom Database System HATODAS, a Web-based tool designed to assist in heavy-atom derivatization of proteins for X-ray crystallography. The denaturation temperature of α-amylase derivatized with gadolinium (Gd) or samarium (Sm) ions increased by 6.2 or 5.7°C, respectively, compared to that of the native protein (60.6°C). The binding of six Gd ions was confirmed by X-ray crystallography of the enzyme at 1.5 Å resolution. DSC and dynamic light-scattering data revealed a correlation between stability and the aggregation state upon addition of Gd ions. These results show that HATODAS search is an effective tool for selecting heavy atoms for stabilization of this protein.


Assuntos
Aspergillus oryzae/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Gadolínio/farmacologia , Samário/farmacologia , alfa-Amilases/química , alfa-Amilases/metabolismo , Aspergillus oryzae/efeitos dos fármacos , Varredura Diferencial de Calorimetria/métodos , Cristalografia por Raios X/métodos , Estabilidade Enzimática , Calefação , Termodinâmica
15.
Haemophilia ; 19(4): 632-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23534894

RESUMO

Most countries still do not achieve 1 IU of factor VIII/capita sufficient for survival. Although primary prophylaxis prevents synovitis, is not universally used. Chronic synovitis is treated with arthroscopy at expense of considerable amount of coagulation factors, and specialized surgeons. Radioactive synovectomy (RS) is a minimally invasive and cost effective alternative to arthroscopy, often considered first the option for persistent synovitis. Even without established causation with cancer, RS is avoided by some, due to this concern. We aim contributing to the understanding of RS safety regarding malignancy, presenting a large number of treated patients, and a single case of cancer. Three centres in Brazil applied RS with (90) Yttrium Citrate, (90) Yttrium hydroxyapatite or (153) Samarium hydroxyapatite in haemophilic joints and performed a survey addressing cancer in these patients. Four hundred and eighty eight patients (ages 3-51) received 1-3 RS (total 842) and follow-up was 6 months to 9 years. One patient aged 14 years presented Ewing sarcoma, 11 months after RS. The tumour was treated successfully with surgery and chemotherapy. Causality of cancer by RS is improbable in this case. Accordingly, latency here is far below minimum 5-10 years for radio-induction of solid tumours. Moreover, ES is not a typically radio-induced tumour, even at high doses. In agreement with others, though recognizing limitations, this study suggests RS is safe regarding cancer induction. Synovitis is a known burden for patients. The decision of making reasonable usage of RS should be outweighed with the risks of leaving synovitis untreated.


Assuntos
Hemofilia A/diagnóstico por imagem , Hidroxiapatitas/efeitos adversos , Hidroxiapatitas/uso terapêutico , Articulações/diagnóstico por imagem , Articulações/patologia , Samário/efeitos adversos , Samário/uso terapêutico , Membrana Sinovial/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Inquéritos Epidemiológicos , Humanos , Hidroxiapatitas/farmacologia , Masculino , Pessoa de Meia-Idade , Neoplasias/induzido quimicamente , Cintilografia , Samário/farmacologia , Adulto Jovem , Radioisótopos de Ítrio/efeitos adversos
16.
Urol Clin North Am ; 39(4): 533-46, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23084529

RESUMO

In men, prostate cancer is the most common non-cutaneous malignancy and the second most common cause of cancer death. Skeletal complications occur at various points during the disease course, either due to bone metastases directly, or as an unintended consequence of androgen deprivation therapy (ADT). Bone metastases are associated with pathologic fractures, spinal cord compression, and bone pain and can require narcotics or palliative radiation for pain relief. ADT results in bone loss and fragility fractures. This review describes the biology of bone metastases, skeletal morbidity, and recent advances in bone-targeted therapies to prevent skeletal complications of prostate cancer.


Assuntos
Neoplasias Ósseas/prevenção & controle , Neoplasias da Próstata/patologia , Antagonistas de Androgênios/efeitos adversos , Antagonistas de Androgênios/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Neoplasias Ósseas/complicações , Neoplasias Ósseas/fisiopatologia , Neoplasias Ósseas/secundário , Ensaios Clínicos como Assunto , Ácido Clodrônico/farmacologia , Ácido Clodrônico/uso terapêutico , Denosumab , Difosfonatos/efeitos adversos , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Fraturas Espontâneas/etiologia , Humanos , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Masculino , Osteoclastos/efeitos dos fármacos , Osteoclastos/fisiologia , Osteoporose/induzido quimicamente , Pamidronato , Qualidade de Vida , Samário/farmacologia , Samário/uso terapêutico , Toremifeno/farmacologia , Toremifeno/uso terapêutico , Ácido Zoledrônico
17.
Appl Radiat Isot ; 69(1): 80-4, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20933431

RESUMO

INTRODUCTION: Novel 1-hydroxy-1,1-bisphosphonates derived from indazole and substituted at the C-3 position were labeled with the radionuclides (46)Sc and (153)Sm. Several parameters such as molar ligand concentration, pH, reaction time and temperature were studied. The radiolabelling yield, reaction kinetics and stability were assessed and radiocomplexes were evaluated by in vitro and in vivo experiments. METHODS: The radionuclides (46)Sc and (153)Sm were obtained by neutron irradiation of natural Sc(2)O(3) and enriched (152)Sm(2)O(3) (98.4%) targets at the neutron flux of 3 × 10(14) n cm(-2)s(-1). The radiolabelling yield, reaction kinetics and stability were accomplished by ascending instant thin layer chromatography. The radiocomplexes were submitted to in vitro experiments (hydroxyapatite binding and lipophilicity) and biodistribution studies in animal models. RESULTS: The radionuclides (46)Sc and (153)Sm were produced with specific activities of 100 and 430 MBq mg(-1), respectively. High radiochemical yields were achieved and the hydrophilic radiocomplexes have shown high degree of binding to hydroxyapatite. Biodistribution studies at 1, 3 and 24h of the 4 radiocomplexes under study, have showed a similar biodistribution profile with a relatively high bone uptake, slow clearance from blood and a very slow rate of total radioactivity excretion from the whole animal body. CONCLUSION: We have developed a new class of indazolebisphosphonates complexes with radioisotopes of samarium and scandium. All complexes have shown high degree of binding to hydroxyapatite, which could be attributed to the ionized phosphonate groups. The bone uptake and the bone-to-muscle ratios were relatively low.


Assuntos
Doenças Ósseas/radioterapia , Difosfonatos/química , Indazóis/química , Radioisótopos/química , Compostos Radiofarmacêuticos/síntese química , Samário/química , Escândio/química , Animais , Difosfonatos/farmacologia , Feminino , Humanos , Indazóis/farmacologia , Camundongos , Radioisótopos/farmacologia , Compostos Radiofarmacêuticos/farmacologia , Ratos , Samário/farmacologia , Escândio/farmacologia
18.
Clin Rheumatol ; 30(1): 77-85, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21120562

RESUMO

The aim of the present study was to investigate the long-term effectiveness of and tolerance to Yttrium-90 and Samarium-153-particulate hydroxyapatite radiation synovectomy in patients with rheumatoid arthritis (RA) and chronic knee synovitis. Eight-four patients (90 knees) with chronic knee synovitis and RA (according to the American College of Rheumatology criteria) participated in a controlled, double-blinded trial. Patients were randomized to receive an intra-articular injection with either 5 mCi Yttrium-90 plus 40 mg of triamcinolone hexacetonide (Y/TH Group), 15 mCi Samarium-153 hydroxyapatite plus 40 mg of triamcinolone hexacetonide (Sm/TH Group), or 40 mg triamcinolone hexacetonide alone (Control Group). Blinded examination at baseline, 1, 4, 12, 32, and 48 weeks post-intervention included a visual analog scale for joint pain and swelling, morning stiffness, range of motion, knee circumference, Likert scale, percentage of improvement, Stanford Health Assessment Questionnaire, Lequesne index, use of non-steroidal anti-inflammatory drugs and corticosteroids, events and adverse effects, calls to the physician, and hospital visits. There were three withdrawals prior to the injections. Regarding the pain, there was a significantly better response in the Y/TH Group versus the Sm/TH Group at T1 (p = 0.025) and versus TH alone at T48 (p = 0.026). The Sm/TH group had more adverse effects (p = 0.042), but these were mild and transitory. For the pain parameter alone, Yttrium-90 radiosynovectomy associated to TH proved superior to Samarium-153 hydroxyapatite radiosynovectomy associated to TH at T1 and to synovectomy with TH at T48. No other statistically significant inter-group differences were detected.


Assuntos
Artrite Reumatoide/metabolismo , Durapatita/química , Articulação do Joelho/metabolismo , Radioisótopos/farmacologia , Samário/farmacologia , Sinovite/metabolismo , Radioisótopos de Ítrio/farmacologia , Doença Crônica , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Sinovite/patologia , Triancinolona Acetonida/análogos & derivados , Triancinolona Acetonida/farmacologia
19.
Exp Dermatol ; 19(8): e124-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20002171

RESUMO

We previously demonstrated that the electrical state of the skin surface influences epidermal permeability barrier homeostasis. At the interface between different materials, electrons are localized heterogeneously and induce electrical potential. In the present study, we evaluated the effects of metals on the barrier recovery. When we put pure gold plate on skin immediately after tape stripping, the barrier recovery rate was faster than the control. The acceleration of barrier recovery was blocked when the plate was earthed (grounded). When a plastic membrane was sandwiched between the plate and the skin, the recovery was delayed in comparison with the control. We then used a germanium diode to regulate the current flow between the plate and the earth. When the current was blocked, the barrier recovery was accelerated, but when the current was not blocked, the recovery was not accelerated. These results suggest that localization of electron might affect for the barrier recovery rate. The level of interfacial electric potential would be different due to the electrochemical property of metal. Thus, we next evaluated the effects of other metals. With samarium, zirconium, iridium and silver, the barrier recovery rate was faster than in the case of gold, while a platinum plate induced slower recovery than in the case of gold. There was a significant correlation between work function of each metal and barrier recovery rate. These results suggest that electron donation from outside accelerated the skin barrier recovery.


Assuntos
Homeostase/efeitos dos fármacos , Metais/farmacologia , Pele/efeitos dos fármacos , Animais , Ouro/farmacologia , Homeostase/fisiologia , Irídio/farmacologia , Masculino , Camundongos , Camundongos Pelados , Modelos Animais , Permeabilidade/efeitos dos fármacos , Samário/farmacologia , Pele/metabolismo , Zircônio/farmacologia
20.
Med Phys ; 36(4): 1219-29, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19472629

RESUMO

Absolute activity evaluation is fundamental for internal radionuclide dosimetry when patient-specific therapy optimization is wanted. Often, quantification is attempted with 3D SPECT image based (IB) methods, but the true concentration values can be underestimated due to the partial volume effect (PVE). This is especially true when small diffuse lesions are present. In this paper, we describe a 3D region of interest (ROI) based quantification method (LS-ROI), which estimates the ROI concentration values directly from the projection data acquired in the tomographic scan once ROIs have been segmented on a CT and/or a SPECT image. The method, which has inherent PVE correction capabilities, was applied both on simulated and on real phantom data. Simulations reflected the case of a patient with bone metastases treated with 153Sm-EDTMP: Both the activity in the metastases and the total retention in the skeleton were evaluated. Thirty noisy data sets were produced in order to evaluate the accuracy and precision of the method. The effect of region segmentation errors on estimated concentrations was thoroughly investigated. Real data were acquired on a NEMA phantom, where a cylindrical central region (283 cm3) simulated the bone and two spheres (10.3 and 25.5 cm3) simulated the metastases. The results obtained with the LS-ROI method were compared with those of a conventional 3D IB method and those of a quantitative conjugate view approach derived from LS-ROI and applied to the anterior and posterior views acquired in the tomographic scan (LS-ROI anterior-posterior: LS-ROI-AP). Simulations showed that when the geometry of regions is known, the LS-ROI method recovered the simulated concentration values within 20%, while the IB method underestimated the concentration in high activity small lesions by as much as 49%. Segmentation errors, up to 44% of the true region volume, produced a higher variation in LS-ROI estimates than in IB ones; however, the overall bias of the LS-ROI estimates (< or = 25%) remained lower than that of IB estimates. In the case of the evaluation of the total retention in the skeleton, the LS-ROI method recovered the simulated value within 2%, while IB underestimated it up to 13%. In all the cases, the LS-ROI-AP method showed an accuracy comparable with that of the LS-ROI one, and a worse precision just because of the lower number of counts used in the analysis. However, a worsening of LS-ROI-AP performances was demonstrated in the case of strong overlap of regions: In this case, a bias of up to 40% was observed. The results obtained on real phantom data confirmed the simulation results: The IB method underestimated activity up to 47% in the smallest sphere, while the bias was reduced to 13% with LS-ROI and LS-ROI-AP estimates. The good quantification capabilities of the LS-ROI method can be useful for absolute activity quantification in the case of small active diffused lesions and constitute the basis for the development of an accurate patient-specific planning strategy in internal radionuclide treatments, provided there is a reliable segmentation of lesions.


Assuntos
Imageamento Tridimensional/métodos , Compostos Organometálicos , Compostos Organofosforados , Radioisótopos/farmacologia , Samário/farmacologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Algoritmos , Simulação por Computador , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador , Metástase Neoplásica , Reconhecimento Automatizado de Padrão , Imagens de Fantasmas , Radiometria/métodos , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA