Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Appl Mater Interfaces ; 15(35): 41666-41679, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37582254

RESUMO

The development of solution-processable n-type molecular semiconductors that exhibit high electron mobility (µe ≥ 0.5 cm2/(V·s)) under ambient conditions, along with high current modulation (Ion/Ioff ≥ 106-107) and near-zero turn on voltage (Von) characteristics, has lagged behind that of other semiconductors in organic field-effect transistors (OFETs). Here, we report the design, synthesis, physicochemical and optoelectronic characterizations, and OFET performances of a library of solution-processable, low-LUMO (-4.20 eV) 2,2'-(2,8-bis(3-alkylthiophen-2-yl)indeno[1,2-b]fluorene-6,12-diylidene)dimalononitrile small molecules, ß,ß'-Cn-TIFDMTs, having varied alkyl chain lengths (n = 8, 12, 16). An intriguing correlation is identified between the solid-isotropic liquid transition enthalpies and the solubilities, indicating that cohesive energetics, which are tuned by alkyl chains, play a pivotal role in determining solubility. The semiconductors were spin-coated under ambient conditions on densely packed (grafting densities of 0.19-0.45 chains/nm2) ultrathin (∼3.6-6.6 nm) polystyrene-brush surfaces. It is demonstrated that, on this polymer interlayer, thermally induced dispersive interactions occurring over a large number of methylene units between flexible alkyl chains (i.e., zipper effect) are critical to achieve a favorable thin-film crystallization with a proper microstructure and morphology for efficient charge transport. While C8 and C16 chains show a minimal zipper effect upon thermal annealing, C12 chains undergo an extended interdigitation involving ∼6 methylene units. This results in the formation of large crystallites having lamellar stacking ((100) coherence length ∼30 nm) in the out-of-plane direction and highly favorable in-plane π-interactions in a slipped-stacked arrangement. Uninterrupted microstructural integrity (i.e., no face-on (010)-oriented crystallites) was found to be critical to achieving high mobilities. The excellent crystallinity of the C12-substituted semiconductor thin film was also evident in the observed crystal lattice vibrations (phonons) at 58 cm-1 in low-frequency Raman scattering. Two-dimensional micrometer-sized (∼1-3 µm), sharp-edged plate-like grains lying parallel with the substrate plane were observed. OFETs fabricated by the current small molecules showed excellent n-channel behavior in ambient with µe values reaching ∼0.9 cm2/(V·s), Ion/Ioff ∼ 107-108, and Von ≈ 0 V. Our study not only demonstrates one of the highest performing n-channel OFET devices reported under ambient conditions via solution processing but also elucidates significant relationships among chemical structures, molecular properties, self-assembly from solution into a thin film, and semiconducting thin-film properties. The design rationales presented herein may open up new avenues for the development of high-electron-mobility novel electron-deficient indenofluorene and short-axis substituted donor-acceptor π-architectures via alkyl chain engineering and interface engineering.

2.
Nat Commun ; 12(1): 6119, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34675208

RESUMO

Molecular engineering via functionalization has been a great tool to tune noncovalent intermolecular interactions. Herein, we demonstrate three-dimensional highly crystalline nanostructured D(C7CO)-BTBT films via carbonyl-functionalization of a fused thienoacene π-system, and strong Raman signal enhancements in Surface-Enhanced Raman Spectroscopy (SERS) are realized. The small molecule could be prepared on the gram scale with a facile synthesis-purification. In the engineered films, polar functionalization induces favorable out-of-plane crystal growth via zigzag motif of dipolar C = O···C = O interactions and hydrogen bonds, and strengthens π-interactions. A unique two-stage film growth behavior is identified with an edge-on-to-face-on molecular orientation transition driven by hydrophobicity. The analysis of the electronic structures and the ratio of the anti-Stokes/Stokes SERS signals suggests that the π-extended/stabilized LUMOs with varied crystalline face-on orientations provide the key properties in the chemical enhancement mechanism. A molecule-specific Raman signal enhancement is also demonstrated on a high-LUMO organic platform. Our results demonstrate a promising guidance towards realizing low-cost SERS-active semiconducting materials, increasing structural versatility of organic-SERS platforms, and advancing molecule-specific sensing via molecular engineering.

3.
Toxicol Mech Methods ; 31(8): 600-608, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34420476

RESUMO

The aim of this study was to investigate the cellular mechanisms that cause valproic acid (VPA)-induced liver damage and the therapeutic effect of Vitamin U (Vit U) on these mechanisms. Female Sprague Dawley rats were randomly divided into four groups: intact control animals, animals that received Vit U (50 mg/kg/day), animals given VPA (500 mg/kg/day), and animals given both VPA and Vit U. The rats in the Vit U + VPA group were administered Vit U by gavage an hour before VPA administration every day for 15 days. Liver tissues were evaluated through histopathological, biochemical, immunohistochemical, and Western blotting techniques. Administration of Vit U with VPA resulted in (i) prevention of histopathological changes caused by VPA; (ii) blockage of the decrease in catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities; prevention of the elevation in gamma-glutamyl transferase (GGT) activity and advanced oxidation protein products (AOPP) level; (iii) increased in the levels of interleukin-1 beta (IL-1ß), active caspase-3, and cytoplasmic cytochrome c; (iv) increase in cleaved poly (ADP-ribose) polymerase (PARP) level and decrease in LC3B (II/I) ratio; (v) increase in the number of proliferating cells nuclear antigen (PCNA) positive hepatocytes. These findings show that Vit U prevents liver damage caused by VPA through increasing the antioxidant enzyme capacity and hepatocyte proliferation by triggering inflammation and apoptosis. These findings suggest that Vit U provides its protective effects against VPA-induced liver damage by stimulating homeostasis and regeneration.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Vitamina U , Animais , Antioxidantes , Apoptose , Proliferação de Células , Feminino , Hepatócitos , Inflamação/induzido quimicamente , Inflamação/prevenção & controle , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Ácido Valproico/toxicidade
4.
Oncol Lett ; 21(3): 209, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33574948

RESUMO

In anticancer therapy, the effectiveness of therapeutics is limited by mutations causing drug resistance. KRAS mutations are the only determinant for cetuximab resistance in patients with colorectal cancer (CRC). However, cetuximab treatment has not been fully successful in the majority of patients with wild-type (WT) KRAS. Therefore, it is important to determine new predictive mutations in CRC treatment. In the present study, the association between AKT1/ß-catenin (CTNNB1) mutations with the drug resistance to cetuximab and other chemotherapeutics used in the CRC treatment was investigated by using site-directed mutagenesis, transfection, western blotting and cell proliferation inhibition assay. Cetuximab resistance was higher in the presence of AKT1 E17K, E49K and L52R mutations, as well as CTNNB1 T41A, S45F and S33P mutations compared with that of respective WT proteins. AKT1/CTNNB1 mutations were also associated with oxaliplatin, irinotecan, SN-38 and 5-fluorouracil resistance. Furthermore, mutant cell viability in oxaliplatin treatment was more effectively inhibited compared with that of the other chemotherapeutic drugs. In conclusion, AKT1/CTNNB1 mutations may be used as an important predictive biomarker in CRC treatment.

5.
ACS Appl Mater Interfaces ; 11(47): 44474-44486, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31609580

RESUMO

The development of solution-processable fluorescent small molecules with highly efficient deep-blue electroluminescence is of growing interest for organic light-emitting diode (OLED) applications. However, high-performance deep-blue fluorescent emitters with external quantum efficiencies (EQEs) over 5% are still scarce in OLEDs. Herein, a novel highly soluble oligo(p-phenyleneethynylene)-based small molecule, 1,4-bis((2-cyanophenyl)ethynyl)-2,5-bis(2-ethylhexyloxy)benzene (2EHO-CNPE), is designed, synthesized, and fully characterized as a wide band gap (2.98 eV) and highly fluorescent (ΦPL = 0.90 (solution) and 0.51 (solid-state)) deep-blue emitter. The new molecule is functionalized with cyano (-CN)/2-ethylhexyloxy (-OCH2CH(C2H5)C4H9) electron-withdrawing/-donating substituents, and ethynylene is used as a π-spacer to form an acceptor (A)-π-donor (D)-π-acceptor (A) molecular architecture with hybridized local and charge transfer (HLCT) excited states. Physicochemical and optoelectronic characterizations of the new emitter were performed in detail, and the single-crystal structure was determined. The new molecule adopts a nearly coplanar π-conjugated framework packed via intermolecular "C-H···π" and "C-H···N" hydrogen bonding interactions without any π-π stacking. The OLED device based on 2EHO-CNPE shows an EQEmax of 7.06% (EQE = 6.30% at 200 cd/m2) and a maximum current efficiency (CEmax) of 5.91 cd/A (CE = 5.34 cd/A at 200 cd/m2) with a deep-blue emission at CIE of (0.15, 0.09). The electroluminescence performances achieved here are among the highest reported to date for a solution-processed deep-blue fluorescent small molecule, and, to the best of our knowledge, it is the first time that a deep-blue OLED is reported based on the oligo(p-phenyleneethynylene) π-framework. TDDFT calculations point to facile reverse intersystem crossing (RISC) processes in 2EHO-CNPE from high-lying triplet states to the first singlet excited state (T2/T3 → S1) (hot-exciton channels) that enable a high radiative exciton yield (ηr ∼ 69%) breaking the theoretical limit of 25% in conventional fluorescent OLEDs. These results demonstrate that properly designed fluorescent oligo(p-phenyleneethynylenes) can be a key player in high-performance deep-blue OLEDs.

6.
Lasers Med Sci ; 32(3): 591-599, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28116535

RESUMO

Photobiomodulation (PBM) describes light-induced photochemical reactions achieved by the application of red or near infrared lasers/LED light with low energy densities. This noninvasive and painless method has been used in some clinical areas but controversial outcomes demand a skeptical look for its promising and potential effects. In this detailed in vitro study, the osteoblast cells were irradiated with 635 and 809 nm diode lasers at energy densities of 0.5, 1, and 2 J/cm2. Cell viability, proliferation, bone formation, and osteoblast differentiation were evaluated by methylthiazole tetrazolium (MTT) assay, Alamar Blue assay, acridine orange/propidium iodide staining, alkaline phosphatase (ALP) activity, Alizarin red staining, and reverse-transcription polymerase chain reaction (RT-PCR) to test the expression of collagen type I, ALPL, and osteocalcin. The results indicate that studied energy doses have a transient effect (48 h after laser irradiation) on the osteoblast viability and proliferation. Similarly, laser irradiation did not appear to have any effect on ALP activity. These results were confirmed by RT-PCR analysis of osteoblast markers. This study suggests that several irradiation parameters and variations in the methods should be clearly established in the laboratory before laser treatment becomes a postulated application for bone tissue regeneration in clinical level.


Assuntos
Lasers , Terapia com Luz de Baixa Intensidade , Osteoblastos/efeitos da radiação , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica/efeitos da radiação , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Osteoblastos/citologia , Osteoblastos/metabolismo , Coloração e Rotulagem
7.
Toxicol Ind Health ; 32(6): 1143-52, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25415872

RESUMO

This study was designed to evaluate the protective effect of water extract of Amaranthus lividus L. (A. lividus) (Amaranthaceae) on carbon tetrachloride (CCl4)-induced toxicity in kidneys of rats. For this purpose, male albino Wistar rats were pretreated with A. lividus (250 and 500 mg/kg body weight (b.w.)) daily for 9 days and a single dose of CCl4 was applied intraperitoneally (50% in olive oil; 1.5 mL/kg b.w.) on the 10th day. All rats were killed 24 h after CCl4 administration, and kidneys were excised and used for determination of histopathological and biochemical parameters. CCl4 administration caused a remarkable increase in lipid peroxidation (LPO) and glutathione levels and glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, myeloperoxidase (MPO) activities and a decrease in catalase (CAT) activity when compared to the control group. Pretreatment with A. lividus (250 and 500 mg/kg b.w.) significantly prevented the elevation in LPO level and MPO activity as well as protected the decrease in CAT activity but did not alter other biochemical parameters. The protective effect of A. lividus was further evident through the decreased histological alterations in kidneys. In conclusion, this study has indicated that A. lividus possesses protective and antioxidant effects against CCl4-induced oxidative kidney damage.


Assuntos
Amaranthus/química , Tetracloreto de Carbono/toxicidade , Nefropatias/tratamento farmacológico , Rim/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Antioxidantes/farmacologia , Catalase/metabolismo , Modelos Animais de Doenças , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Rim/patologia , Nefropatias/induzido quimicamente , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Substâncias Protetoras/farmacologia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
8.
J Food Drug Anal ; 23(1): 57-62, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28911446

RESUMO

In this study, the antioxidant and antiacetylcholinesterase activities of Sorbus torminalis (L.) Crantz fruits were evaluated. Total phenolic and flavonoid compounds, 2,2'-azino-bis (3-ethylbenzothioazoline-6-sulfonic acid), 2,2'-diphenyl-1-picrylhydrazyl, and superoxide anion radicals scavenging activities and ferric-reducing antioxidant power of water, ethyl acetate, acetone, and methanol extracts were determined for the measurement of the antioxidant activity. Quercetin and α-tocopherol were used as standard antioxidants. The inhibitory effect of the water extract on acetylcholinesterase (AChE) was evaluated using the Ellman method and galantamine was used as a standard. Water extract had the highest total phenolic concentration and the strongest antioxidant activity followed by ethyl acetate and acetone extracts whereas methanol extract has the lowest phenolics and weakest antioxidant activity. Moreover, water extract showed moderate ability to inhibit AChE. It was concluded that fruits of S. torminalis have antioxidant and anti-AChE activities and that the plant might be a natural source of antioxidants and AChE inhibitors.

9.
Indian J Pharmacol ; 46(3): 322-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24987181

RESUMO

OBJECTIVES: The aim of this study was to investigate the antibacterial, anti-inflammatory, and antioxidant activities and probable toxic effects of Aloe vera (AV) in a rat peritonitis model. MATERIALS AND METHODS: RATS WERE DIVIDED INTO FIVE GROUPS: (1) Control group, (2) AV group, (3) peritonitis group (P), (4) peritonitis + AV group (P + AV), and (5) peritonitis + antibiotherapy group (P + Ab). Ultrafiltration (UF) rates were determined and colony and leukocyte counts were calculated in the dialysate. Glucose, blood urea nitrogen (BUN), creatinine levels, and alanine transaminase (ALT) activities were studied in blood. Glucose, interleukins (IL-1ß, IL-6), and prostaglandin E2 (PGE2) were studied in dialysate and peritoneal tissue for the assessment of the anti-inflammatory effect. Copper/zinc superoxide dismutase (Cu, Zn-SOD), malondialdehyde (MDA), and nitric oxide (NO) were also investigated in peritoneal tissue. RESULTS: Aloe vera increased the UF rate and lowered leukocyte numbers in the peritonitis group. There was no significant difference in blood and dialysate glucose, BUN, creatinine levels and ALT activity among control and AV groups. AV decreased IL-1ß, IL-6 and PGE2 in peritonitis, showing good anti-inflammatory effect. AV showed antioxidant effect on the chosen antioxidant parameters Cu, Zn-SOD, MDA, and NO. CONCLUSION: It was concluded that, AV might be used in peritonitis for its probable UF increasing, anti-inflammatory, and antioxidant effects.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Peritonite/tratamento farmacológico , Preparações de Plantas/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Aloe , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Carga Bacteriana , Soluções para Diálise/metabolismo , Dinoprostona/metabolismo , Modelos Animais de Doenças , Géis , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Contagem de Leucócitos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Óxido Nítrico/metabolismo , Peritônio/metabolismo , Peritonite/metabolismo , Peritonite/patologia , Folhas de Planta , Preparações de Plantas/farmacologia , Ratos Wistar , Infecções Estafilocócicas/metabolismo , Infecções Estafilocócicas/patologia , Staphylococcus aureus/isolamento & purificação , Superóxido Dismutase/metabolismo
10.
Bosn J Basic Med Sci ; 14(2): 105-9, 2014 05.
Artigo em Inglês | MEDLINE | ID: mdl-24856383

RESUMO

Between their broad spectrum of action, vanadium compounds are shown to have insulin mimetic/enhancing effects. Increasing evidence in experimental and clinical studies suggests that oxidative stress plays a major role in the pathogenesis of diabetes and on the onset of diabetic complications. Thus, preventive therapy can alleviate the possible side effects of the disease. The aim of the present study was to investigate the effect of vanadyl sulfate supplementation on the antioxidant system in the stomach tissue of diabetic rats. Male Swiss albino rats were randomly divided into 4 groups: control; control+vanadyl sulfate; diabetic; diabetic+vanadyl sulfate. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ; 65 mg/kg body weight). Vanadyl sulfate (100 mg/kg body weight) was given daily by gavage for 60 days. At the last day of the experiment, stomach tissues were taken and homogenized to make a 10% (w/v) homogenate. Catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), myeloperoxidase (MPO), carbonic anhydrase (CA), glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) activities were determined in the stomach tissue. CAT, SOD, GR, GPx, GST, CA, G6PD and LDH activities were increased in diabetic rats when compared to normal rats. Vanadium treatment significantly reduced the elevated activities of GR, GPx, GST compared with the diabetic group whereas the decreases in CAT, SOD, CA, G6PD and LDH activities were insignificant. No significant change was seen for MPO activity between the groups. It was concluded that vanadium could be used for its ameliorative effect against oxidative stress in diabetes.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Hipoglicemiantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estômago/efeitos dos fármacos , Compostos de Vanádio/farmacologia , Administração Oral , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Masculino , Oxirredutases/metabolismo , Ratos , Estômago/enzimologia , Compostos de Vanádio/uso terapêutico
11.
Gene ; 540(2): 226-31, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24566004

RESUMO

Identification of risk factors for osteoporosis has been essential for understanding the development of osteoporosis. The collagen type I alpha1 (COL1A1) gene is suggested to be implicated in reduced bone mineral density (BMD) in osteoporosis. In the present study, the investigation of the effects of Sp1 polymorphic variants of COL1A1 gene on BMD values, and the determination of the association between COL1A1 Sp1 gene variants and osteoporosis risk factors in the context of gene-environment interaction in Turkish postmenopausal women were aimed. For the detection of COL1A1 Sp1 polymorphism, PCR-RFLP techniques have been used. BMD for lumbar spine (L1-L4) and hip (femoral neck and total hip) was measured by DXA. This study was carried out using a sample of 254 postmenopausal women. We observed a trend decrease in BMD values in the subjects with "ss" genotype having lower BMD of lumbar spine, femoral neck and total hip than those with "SS" and "Ss" genotype, however the differences did not reach statistical significance (P>0.05). We also found that the frequencies of the BMD under mean values at the femoral neck (57.5%) and total hip (76.2%) increased considerably in the subjects carrying "Ss/ss" genotypes in combination of having family history of osteoporosis (61.5% for femoral neck) and smoking history (90.0% for total hip). This population-based study indicates that COL1A1 Sp1 polymorphism may contribute to the development of osteoporosis in combination of osteoporosis risk factors in Turkish postmenopausal women.


Assuntos
Densidade Óssea/genética , Colágeno Tipo I/genética , Osteoporose Pós-Menopausa/genética , Polimorfismo Genético , Idoso , Cadeia alfa 1 do Colágeno Tipo I , Feminino , Colo do Fêmur/patologia , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Quadril/patologia , Humanos , Vértebras Lombares/patologia , Pessoa de Meia-Idade , Análise Multivariada , Ossos Pélvicos/patologia , Pós-Menopausa , Fatores de Risco , Turquia
12.
J Enzyme Inhib Med Chem ; 29(4): 457-68, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23738950

RESUMO

In this study, 5-chloro-3H-spiro-[1,3-benzothiazole-2,3'-indole]-2'(1'H)-one derivatives 3a-l were synthesized by the reaction of 1H-indole-2,3-diones 1a-l with 2-amino-4-chlorothiophenol 2 in ethanol. 3a-l were tested for their abilities to inhibit lipid peroxidation (LP), scavenge DPPH(•) and ABTS(•+) radicals, and to reduce Fe(3+) to Fe(2+). Most of the tested compounds exhibited potent scavenging activities against ABTS(•+) radical, reducing powers and strong inhibitory capacity on LP. 3 a, 3 d, 3 e, 3h, 3 j and 3 k chosen as prototypes were evaluated in the National Cancer Institute's in vitro primary anticancer assay. The greatest growth inhibitions were observed against a non-small cell lung cancer cell line HOP-92 for R1-fluoro substituted 3 d and a renal cancer cell line RXF-393 for R-chloro substituted 3 e in the primary screen.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Benzotiazóis/farmacologia , Compostos de Bifenilo/antagonistas & inibidores , Radicais Livres/antagonistas & inibidores , Indóis/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Picratos/antagonistas & inibidores , Compostos de Espiro/farmacologia , Ácidos Sulfônicos/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Antioxidantes/síntese química , Antioxidantes/química , Benzotiazóis/antagonistas & inibidores , Benzotiazóis/síntese química , Benzotiazóis/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/síntese química , Indóis/química , Estrutura Molecular , Compostos de Espiro/síntese química , Compostos de Espiro/química , Relação Estrutura-Atividade
13.
Mol Biol Rep ; 40(11): 6519-24, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24057271

RESUMO

There is increasing evidence of a biochemical link between oxidative stress and bone metabolism. Oxidative stress has been shown to be involved in bone resorption as it causes loss of bone mineral density (BMD). Paraoxonase 1 (PON1), can prevent these effects of the oxidative stress on bone formation. It has been suggested that the PON1 gene as possibly implicated in reduced BMD in bone fragility cases. It has been hypothesized that PON1 gene polymorphisms may influence both the risk of osteoporosis and osteopenia occurrence and prognosis. The aim of our study is to evaluate the relationship between PON1 polymorphisms and bone fragility development. Seventy-four osteoporotic, 121 osteopenic and 79 nonosteoporotic postmenopausal women were recruited. For detection of the polymorphisms, polymerase chain reaction-restriction fragment length polymorphism techniques have been used. BMD was measured at the lumbar spine and hip by dual-energy X-ray absorptiometry. Distributions of PON1 (PON 192 and PON 55) polymorphisms in study groups were not significantly different. But, there was medium strength connection between in the osteopenic with control groups regarding PON1 55-PON1 192 haplotypes and we found a power strength connection between in the osteoporosis with control groups regarding PON1 55-PON1 192 haplotypes. Furthermore, subjects with PON1 192RR and PON1 55LL genotypes had lower PON activity values of osteoporotic subject compared to healthy control and this difference was statistically significant (p < 0.05). This result suggest that PON1 genotypes could be higher risk for osteoporosis, as determined by reduced BMD.


Assuntos
Arildialquilfosfatase/sangue , Arildialquilfosfatase/genética , Doenças Ósseas Metabólicas/sangue , Doenças Ósseas Metabólicas/genética , Polimorfismo de Nucleotídeo Único , Idoso , Alelos , Densidade Óssea/genética , Estudos de Casos e Controles , Ativação Enzimática , Feminino , Frequência do Gene , Genótipo , Humanos , Pessoa de Meia-Idade , Osteoporose/sangue , Osteoporose/genética , Turquia
14.
Mol Biol Rep ; 39(6): 6723-30, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22311020

RESUMO

It has been suggested that the estrogen receptor alpha (ERα) and vitamin D receptor (VDR) genes as possibly implicated in reduced bone mineral density (BMD) in osteoporosis. The present study investigated the relation of ERα PvuII/XbaI polymorphisms and VDR FokI/TaqI polymorphisms with BMD in Turkish postmenopausal women. Eighty-one osteoporotic and 122 osteopenic postmenopausal women were recruited. For detection of the polymorphisms, polymerase chain reaction-restriction fragment lenght polymorphism techniques have been used. BMD was measured at the lumbar spine and hip by dual-energy X-ray absorptiometry. Distributions of ERα (PvuII dbSNP: rs2234693, XbaI dbSNP: rs9340799) and VDR genotypes (FokI dbSNP rs10735810, TaqI dbSNP: rs731236) were similar in study population. Although overall prevalence of osteoporosis had no association with these genotypes, the prevalence of decreased femoral neck BMD values were higher in the subjects with ERα PvuII "PP" and ERα XbaI "XX" genotypes than in those with "Pp/pp" genotypes and "xx" genotype, respectively (P < 0.05). Furthermore, subjects with VDR FokI "FF" genotype had lower BMD values of femoral neck and total hip compared to those with "Ff" genotype (P < 0.05). In the logistic regression analysis, we confirmed the presence of relationships between the VDR FokI "FF" genotypes, BMI ≤ 27.5, age ≥ 55 and the increased risk of femoral neck BMD below 0.8 value in postmenopausal women. The present data suggests that the ERα PvuII/XbaI and VDR FokI polymorphisms may contribute to the determination of bone mineral density in Turkish postmenopausal women.


Assuntos
Densidade Óssea/genética , Receptor alfa de Estrogênio/genética , Osteoporose Pós-Menopausa/genética , Polimorfismo de Nucleotídeo Único , Receptores de Calcitriol/genética , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/patologia , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Quadril/diagnóstico por imagem , Quadril/patologia , Humanos , Modelos Logísticos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/patologia , Pós-Menopausa , Radiografia , Fatores de Risco , Turquia
15.
Genet Test Mol Biomarkers ; 16(4): 229-33, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22081934

RESUMO

AIM: In this study, we investigated whether monocyte chemotactic protein 1 (MCP-1) and CC chemokine receptor 2 (CCR2) gene polymorphisms account for an increased risk of osteoporosis or osteopenia. METHODS: Three hundred three postmenopausal women, 80 osteoporotic, 123 osteopenic, and 100 unrelated age-matched healthy controls, were included in the study. Genotyping of MCP-1 A2518G and CCR2 V64I gene polymorphisms were detected by PCR-RFLP. RESULTS: We, for the first time, demonstrated the positive association of MCP-1 GG, CCR2 Val/Ile, and CCR2 Val+ genotype with osteoporosis risk. However, CCR2 Ile/Ile genotype frequencies were high in the control group compared with those of the patients with osteoporosis and osteopenia. Haplotype analysis confirmed the association of MCP-1/CCR2 gene variants with osteopenia and revealed that the frequency of MCP-1 A:CCR2 Val haplotype was significantly higher in patients when compared with controls. CONCLUSIONS: In conclusion, our findings have suggested that MCP-1 and CCR2 gene variants were risk factors for osteoporosis and osteopenia.


Assuntos
Doenças Ósseas Metabólicas/genética , Quimiocina CCL2/genética , Variação Genética , Osteoporose/genética , Receptores CCR2/genética , Adulto , Idoso , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Pós-Menopausa
16.
Biometals ; 24(5): 943-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21479831

RESUMO

In recent years, the role of free radical damage consequent to oxidative stress is widely discussed in diabetic complications. In this aspect, the protection of cell integrity by trace elements is a topic to be investigated. Vanadium is a trace element believed to be important for normal cell function and development. The aim of the present study was to investigate the effect of vanadyl sulfate supplementation on the antioxidant system in the muscle tissue of diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) to male Swiss albino rats. The rats were randomly divided into 4 groups: Group I, control; Group II, vanadyl sulfate control; Group III, STZ-diabetic untreated; Group IV, STZ-diabetic treated with vanadyl sulfate. Vanadyl sulfate (100 mg/kg) was given daily by gavage for 60 days. At the last day of the experiment, rats were killed, muscle tissues were taken, homogenized in cold saline to make a 10% (w/v) homogenate. Body weights and blood glucose levels were estimated at 0, 30 and 60th days. Antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), as well as carbonic anhydrase (CA), myeloperoxidase (MPO) activities and protein carbonyl content (PCC) were determined in muscle tissue. Vanadyl sulfate administration improved the loss in body weight due to STZ-induced diabetes and decreased the rise in blood glucose levels. It was shown that vanadium supplementation to diabetic rats significantly decrease serum antioxidant enzyme levels, which were significantly raised by diabetes in muscle tissue showing that this trace element could be used as preventive for diabetic complications.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Suplementos Nutricionais , Músculo Esquelético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Compostos de Vanádio/administração & dosagem , Animais , Antioxidantes/metabolismo , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/induzido quimicamente , Masculino , Músculo Esquelético/metabolismo , Ratos , Estreptozocina , Compostos de Vanádio/farmacologia
17.
Nat Prod Res ; 24(6): 580-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20397108

RESUMO

In this work we report the isolation and characterisation of seven flavonoids, the levels of total phenolics, flavonoids and proanthocyanidins, and the antioxidant activity of the leaf extract of Rosa agrestis Savi (Rosaceae). The results showed that the R. agrestis leaf extract exhibited significant antioxidative activity as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) (EC(50) = 47.4 microg mL(-1)), inhibited both beta-carotene bleaching and deoxyribose degradation, quenched a chemically generated superoxide anion in vitro and showed high ferrous ion chelating activity. Reactivity towards 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation and ferric-reducing antioxidant power (FRAP) values were equivalent to 2.30 mM L(-1) Trolox, the water soluble alpha-tocopherol analogue, and 1.91 mM L(-1) Fe(2+), respectively. The high antioxidant activity of the extract appeared to be attributed to its high content of total phenolics, flavonoids and proanthocyanidins. The flavonoids isolated from R. agrestis leaves were diosmetin, kaempherol, quercetin, kaempherol 3-glucoside (astragalin), quercetin 3-rhamnoside (quercitrin), quercetin 3-xyloside and quercetin 3-galactoside (hyperoside). Diosmetin (5,7,3'-trihydroxy-4'-methoxyflavone) was isolated for the first time from Rosa species.


Assuntos
Flavonoides/análise , Sequestradores de Radicais Livres/análise , Quelantes de Ferro/análise , Rosa/química , Compostos de Bifenilo , Compostos Férricos , Radical Hidroxila , Ácido Linoleico , Fenóis/análise , Picratos , Folhas de Planta/química , Proantocianidinas/análise , Superóxidos , beta Caroteno
18.
Phytother Res ; 21(11): 1070-5, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17685385

RESUMO

In this study, the prophylactic effect of the main lectin present in Aloe vera leaf pulp extract (Aloctin I) was assayed against Ehrlich ascites tumours in mice. The lectin administered prophylactically before tumour implantation regressed tumour size, however, this activity was less potent than that of the A. vera leaf pulp extract previously shown in our laboratory. Accordingly, serum sialic acid and tumour necrosis factor alpha (TNFalpha) levels, chosen as tumour markers, were decreased significantly by the prophylactic administration of the lectin. The increase in spleen and thymus weights in the group given only Aloctin I, could be explained by the immunomodulatory and mitogenic effects of lectins. These findings, along with lymphoid hyperplasia observed in spleen and thymus, suggest that the tumour preventive effect of Aloctin I could be due to its immunomodulatory activity.


Assuntos
Aloe/química , Carcinoma de Ehrlich/prevenção & controle , Folhas de Planta/química , Lectinas de Plantas/uso terapêutico , Animais , Carcinoma de Ehrlich/sangue , Carcinoma de Ehrlich/patologia , Contagem de Leucócitos , Masculino , Camundongos , Ácido N-Acetilneuramínico/sangue , Tamanho do Órgão/efeitos dos fármacos , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia , Baço/efeitos dos fármacos , Baço/patologia , Timo/efeitos dos fármacos , Timo/patologia , Fator de Necrose Tumoral alfa/sangue
19.
Eur J Cancer Prev ; 16(2): 151-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17297391

RESUMO

Among the various known therapeutic effects of Aloe vera (L.) Burm. fil., a few recent studies have shown that preparations of the plant leaves can prevent or regress the growth of certain tumours. In this study, undertaken with A. vera leaf pulp extract against Ehrlich ascites tumours in mice, the animals were separated into five groups: I - healthy control, II - tumour control, III - experiment 1 (extract given before tumour inoculation), IV - experiment 2 (extract given with tumour inoculation) and V - experiment 3 (extract given after tumour inoculation). Ehrlich ascites tumours (0.33 ml) were injected subcutaneously into groups II-V. Aloe extract was injected at 55 mg protein/kg, twice a week for 21 days. Tumour size, thymus and spleen weights were measured, as well as leucocyte count, tumour necrosis factor-alpha and sialic acid as tumour markers. The best inhibitory effect on tumour growth was obtained with the extract given prophylactically before tumour implantation (experiment 1), although Aloe extract also regressed tumour sizes when given simultaneously with (experiment 2), or therapeutically after (experiment 3), tumour implantation. Accordingly, serum sialic acid and tumour necrosis factor-alpha levels, chosen as tumour markers, which were raised in the tumour control group, were significantly decreased by the prophylactic administration of the extract. The increase in leucocyte count seen in experiment 1 and 2 groups, along with lymphoid hyperplasia observed in spleen and thymus necroscopy, lead us to think that the tumour preventive effect of Aloe could be due to its immunomodulatory activity. According to our results, A. vera could be proposed as a prophylactic for cancer prevention.


Assuntos
Aloe , Carcinoma de Ehrlich/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Folhas de Planta , Animais , Masculino , Camundongos
20.
Tuberk Toraks ; 55(4): 418-28, 2007.
Artigo em Turco | MEDLINE | ID: mdl-18224514

RESUMO

Allergic bronchopulmonary aspergillosis (ABPA) occurs in approximately 1-7.6% of patients with asthma. This incidence is low enough not to be considered in the differential diagnosis but also high enough to be an important disease. Since the symptoms and laboratory tests are not specific for ABPA, the diagnosis may be delay for years. However the failure to diagnose and treat ABPA for long term may result in fibrotic lung disease. This article focuses on the clinical and the laboratory aspects, and the management of ABPA in the light of three cases.


Assuntos
Aspergilose Broncopulmonar Alérgica/diagnóstico , Adulto , Aspergilose Broncopulmonar Alérgica/diagnóstico por imagem , Aspergilose Broncopulmonar Alérgica/patologia , Árvores de Decisões , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...