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1.
Phys Chem Chem Phys ; 23(47): 26674-26679, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34668906

RESUMO

Fe-N-C electrocatalysts hold a great promise for Pt-free energy conversion, driving the electrocatalysis of oxygen reduction and evolution, oxidation of nitrogen fuels, and reduction of N2, CO2, and NOx. Nevertheless, the catalytic role of iron carbide, a component of nearly every pyrolytic Fe-N-C material, is at the focus of a heated controversy. We now resolve the debate by examining a broad range of Fe3C sites, spanning across many typical size distributions and carbon environments. Removing Fe3C selectively by a non-oxidizing acid reveals its inactivity towards two representative reactions in alkaline media, oxygen reduction and hydrazine oxidation. The activity is assigned to other pre-existing sites, most probably Fe-Nx. DFT calculations prove that the Fe3C surface binds O and N intermediates too strongly to be catalytic. By settling the argument on the catalytic role of Fe3C in alkaline electrocatalysis, we hope to spur innovation in this critical field.

2.
Isr Med Assoc J ; 21(10): 671-675, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599509

RESUMO

BACKGROUND: Recently, Israel established the first national-level adult cardiac surgery database, which was linked to the Society of Thoracic Surgeons (STS). OBJECTIVES: To validate and compare the STS predicted risk of mortality (PROM) to logistic EuroSCORE I (LESI) and EuroSCORE II (ESII) in Israeli patients undergoing cardiac surgery. METHODS: We retrospectively studied 1279 consecutive patients who underwent cardiac surgeries with a calculable PROM. Data were prospectively entered into our database and used to calculate PROM, LESI, and ESII. Scores were normalized and correlated using linear regression and Pearson's test. To examine model calibration, we plotted the total observed versus expected mortality for each score and across five risk-score subgroups. Model discrimination was assessed by measuring the area under the receiver operating curves. RESULTS: The observed 30-day operative mortality was 1.95%. The median (IQ1; IQ3) PROM, LESI, and the ESII scores were 1.45% (0.69; 3.22), 4.54% (2.28; 9.27), and 1.88% (1.18; 3.54), respectively, with observed over expected ratios of 0.63 (95% confidence interval [95%CI] 0.42-0.93), 0.59 (95%CI 0.40-0.87), and 0.24 (95%CI 0.17-0.36), respectively, (STS vs. ESII P = 0.36, STS vs. LESI P = 0.0001). There was good correlation among all scores. All models overestimated mortality. Model discrimination was high and similar for all three scores. Model calibration of the STS, PROM, and ESII were more accurate than the LESI, particularly in higher risk subgroups. CONCLUSIONS: All scores overestimated mortality. In Israeli patients, the STS, PROM, and ESII risk-scores were more reliable metrics than LESI, particularly in higher risk patients.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Gestão de Riscos/métodos , Gestão de Riscos/estatística & dados numéricos , Idoso , Bases de Dados Factuais , Feminino , Humanos , Israel , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Fatores de Risco , Índice de Gravidade de Doença , Sociedades Médicas , Cirurgia Torácica
5.
J Heart Valve Dis ; 25(3): 349-355, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27989046

RESUMO

BACKGROUND AND AIM OF THE STUDY: The prosthetic valve of choice in patients with carcinoid valve disease (CVD) remains controversial due to the limited life expectancy of patients with advanced-stage neuroendocrine tumors (NETs) on the one hand, and concerns regarding structural valve deterioration (SVD) on the other hand. METHODS: The records of 17 patients (11 females, seven males; mean age 65 ± 11 years; undergoing 18 operations) with primarily right heart failure due to CVD were reviewed. All patients received somatostatin analogs perioperatively. Hospital and follow up data (acquired via direct patient contact and echocardiography) collected included baseline characteristics, procedural details, and clinical outcomes. RESULTS: The primary NET site was the ileum (n = 11), lungs (n = 2) and stomach, colon and appendix (n = 1 each). In one patient the primary tumor location could not be identified. Preoperative urinary levels of 5-hydroxyindole acetic acid (5-HIAA; 61 ± 36 mg/24 h) and serum levels of chromogranin A (2926 ± 4057 ng/ml) were 10- and 50-fold greater than normal, respectively. A total of 23 valves was implanted: five tricuspid valve replacements (TVR; four tissue and one mechanical), TVR and pulmonary valve replacements (PVR; three tissue and one mechanical), and TVR and mitral valve replacements (MVR; one tissue and two mechanical). The 30-day mortality was 11% (n = 2). No patient experienced a carcinoid crisis. The mean follow up was 24 ± 21 months (range: 4-85 months). Four patients (receiving seven valves) developed SVD at 12, 14, 15, and 20 months after surgery, and all of these patients died. The actuarial four-year survival and freedom from SVD were 23 ± 14% and 43 ± 15%, respectively. CONCLUSIONS: The data acquired suggested that the main advantage of tissue valve prostheses, namely to avoid lifelong, intense anticoagulation, might be offset by accelerated SVD. The use of mechanical valves should be considered in CVD patients with a large primary tumor mass and persistent high urinary levels of 5-HIAA, and who are unresponsive to therapy.


Assuntos
Doença Cardíaca Carcinoide/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Valvas Cardíacas/cirurgia , Tempo para o Tratamento , Idoso , Anticoagulantes/uso terapêutico , Doença Cardíaca Carcinoide/diagnóstico por imagem , Doença Cardíaca Carcinoide/mortalidade , Doença Cardíaca Carcinoide/fisiopatologia , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/mortalidade , Doenças das Valvas Cardíacas/fisiopatologia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Valvas Cardíacas/diagnóstico por imagem , Valvas Cardíacas/fisiopatologia , Humanos , Israel , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Desenho de Prótese , Estudos Retrospectivos , Fatores de Risco , Texas , Fatores de Tempo , Resultado do Tratamento
6.
Bratisl Lek Listy ; 117(2): 106-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26830042

RESUMO

OBJECTIVES: Cisplatin (cis-diamminedichloroplatinum (II)) is a widely-used platinum-based chemotherapeutic agent which has dose-limiting side-effects. Also, the drug resistance is another instance that decreases treatment success in cisplatin chemotherapy. The growing body of evidence suggests that curcumin, a polyphenolic compound extracted from the spice turmeric, may exert synergistic effects and sensitize malign cells to cisplatin, while alleviating cytotoxicity-related side-effects. The present study was aimed to investigate mood-associated interactions between cisplatin and curcumin. MATERIALS AND METHODS: Thirty-four adult male Wistar albino rats were randomly assigned to four groups as control, curcumin (300 mg/kg/day, p.o. for 5 weeks), cisplatin (5 mg/kg/week, i.p. for 5 weeks), and curcumin plus cisplatin (same doses as above). The open field, elevated plus maze, and forced swim tests were engaged to evaluate mood-associated behaviors. RESULTS: We demonstrated that depression- and anxiety-like behaviors were not altered by the administration of curcumin along with the chronic cisplatin treatment. CONCLUSION: According to the results of the present study, we concluded that curcumin might be regarded as a safe adjuvant in cisplatin chemotherapy in terms of the mood-associated behaviors (Fig. 4, Ref. 41).


Assuntos
Comportamento Animal/efeitos dos fármacos , Cisplatino , Curcumina , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Curcumina/administração & dosagem , Curcumina/efeitos adversos , Modelos Animais de Doenças , Sinergismo Farmacológico , Masculino , Ratos , Ratos Wistar
7.
J Cell Mol Med ; 19(8): 1887-99, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25754218

RESUMO

Vascular endothelial cell (VEC) senescence is considered an early event in the development of atherosclerotic lesions. Stressful stimuli, in particular oxidative stress, have been linked to premature senescence in the vasculature. Foam cells are a major source of reactive oxygen species and may play a role in the induction of VEC senescence; hence, we investigated their involvement in the induction of VEC senescence in a co-culture transwell system. Primary bovine aortic endothelial cells, exposed to the secretome of THP-1 monocyte-derived foam cells, were analysed for the induction of senescence. Senescence associated ß-galactosidase activity and the expression of p16 and p21 were increased, whereas phosphorylated retinoblastoma protein was reduced. This senescent phenotype was mediated by 4-hydroxnonenal (4-HNE), a lipid peroxidation product secreted from foam cells; scavenging of 4-HNE in the co-culture medium blunted this effect. Furthermore, both foam cells and 4-HNE increased the expression of the pro-oxidant thioredoxin-interacting protein (TXNIP). Molecular manipulation of TXNIP expression confirmed its involvement in foam cell-induced senescence. Previous studies showed that peroxisome proliferator-activated receptor (PPAR)δ was activated by 4-hydroalkenals, such as 4-HNE. Pharmacological interventions supported the involvement of the 4-HNE-PPARδ axis in the induction of TXNIP and VEC senescence. The association of TXNIP with VEC senescence was further supported by immunofluorescent staining of human carotid plaques in which the expression of both TXNIP and p21 was augmented in endothelial cells. Collectively, these findings suggest that foam cell-released 4-HNE activates PPARδ in VEC, leading to increased TXNIP expression and consequently to senescence.


Assuntos
Aldeídos/farmacologia , Proteínas de Transporte/metabolismo , Senescência Celular/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Espumosas/metabolismo , Animais , Biomarcadores/metabolismo , Bovinos , Linhagem Celular , Técnicas de Cocultura , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Imunofluorescência , Células Espumosas/citologia , Células Espumosas/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Modelos Biológicos , PPAR delta/metabolismo , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia
8.
Mol Cell Biochem ; 400(1-2): 57-68, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25351341

RESUMO

In the management of type 2 diabetes mellitus, Dapagliflozin (DAPA) is a newly introduced selective sodium-glucose co-transporter 2 inhibitor which promotes renal glucose excretion. Little is known about the effects of DAPA on the electromechanical function of the heart. This study investigated the effects of DAPA on ventricular myocyte shortening and intracellular Ca(2+) transport in streptozotocin (STZ)-induced diabetic rats. Shortening, Ca(2+) transients, myofilament sensitivity to Ca(2+) and sarcoplasmic reticulum Ca(2+), and intracellular Ca(2+) current were measured in isolated rats ventricular myocytes by video edge detection, fluorescence photometry, and whole-cell patch-clamp techniques. Diabetes was characterized in STZ-treated rats by a fourfold increase in blood glucose (440 ± 25 mg/dl, n = 21) compared to Controls (98 ± 2 mg/dl, n = 19). DAPA reduced the amplitude of shortening in Control (76.68 ± 2.28 %, n = 37) and STZ (76.58 ± 1.89 %, n = 42) ventricular myocytes, and reduced the amplitude of the Ca(2+) transients in Control and STZ ventricular myocytes with greater effects in STZ (71.45 ± 5.35 %, n = 16) myocytes compared to Controls (92.01 ± 2.72 %, n = 17). Myofilament sensitivity to Ca(2+) and sarcoplasmic reticulum Ca(2+) were not significantly altered by DAPA in either STZ or Control myocytes. L-type Ca(2+) current was reduced in STZ myocytes compared to Controls and was further reduced by DAPA. In conclusion, alterations in the mechanism(s) of Ca(2+) transport may partly underlie the negative inotropic effects of DAPA in ventricular myocytes from STZ-treated and Control rats.


Assuntos
Compostos Benzidrílicos/administração & dosagem , Diabetes Mellitus Experimental/tratamento farmacológico , Glucose/metabolismo , Glucosídeos/administração & dosagem , Miócitos Cardíacos/metabolismo , Animais , Glicemia , Cálcio/metabolismo , Diabetes Mellitus Experimental/patologia , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Técnicas de Patch-Clamp , Ratos , Estreptozocina/toxicidade
9.
Biotechnol Appl Biochem ; 62(1): 132-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24847915

RESUMO

A low-cost, portable, and disposable paper-type tyrosinase biosensor was developed for determination of phenolic compounds, using a paper-strip absorption method. Tyrosinase and a chromophore (3-methyl-2-benzothiazolinone hydrazone) were immobilized on paper strips to manufacture the biosensor, which was tested on a nontoxic substrate (l-dopamine). The biosensor was responsive to phenolic compounds such as 4-chlorophenol, catechol, m-cresol, and p-cresol. The sensor showed stability for 70 days. The developed biosensor can be used for remote on-site qualitative monitoring of phenolic compounds in wastewater samples.


Assuntos
Técnicas Biossensoriais/métodos , Monofenol Mono-Oxigenase/metabolismo , Papel , Fenóis/análise , Agaricales/enzimologia , Benzotiazóis/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Hidrazonas/química , Cinética , Limite de Detecção , Monofenol Mono-Oxigenase/química , Fenóis/química
10.
J Obstet Gynaecol ; 35(7): 696-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25692404

RESUMO

The aim of this study was to evaluate the relationship between placental localisation and perinatal outcomes. This study was performed in a tertiary centre hospital by retrospectively analysing the medical records of patients who were followed up and underwent delivery in the same hospital. The patients were divided into two groups according to the placental locations (central and lateral) in their routine sonographic findings between the 18 and 24 weeks' gestation. Out of 1,057 patients, 87.4% (n = 919) had centrally located placentas and 12.6% (n = 133) had laterally located placentas. Preeclampsia was found to be significantly higher in the lateral placental location group (4.5% vs. 1.6%; p = 0.027). There was a significant correlation with foetal growth restriction (FGR), preterm birth rates, low Apgar scores and need for neonatal intensive care unit in the lateral placental location group (p < 0.05). The pregnant women with laterally located placentas should be followed up promptly with special care for the risk of preeclampsia and FGR, and poor neonatal outcomes.


Assuntos
Retardo do Crescimento Fetal/epidemiologia , Placenta/diagnóstico por imagem , Pré-Eclâmpsia/epidemiologia , Nascimento Prematuro/epidemiologia , Adulto , Índice de Apgar , Feminino , Humanos , Incidência , Terapia Intensiva Neonatal , Oligo-Hidrâmnio/epidemiologia , Placenta/patologia , Gravidez , Estudos Retrospectivos , Ultrassonografia Pré-Natal , Adulto Jovem
11.
Clin Exp Obstet Gynecol ; 42(6): 801-4, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26753490

RESUMO

OBJECTIVE: The aim of this study was to determine the value of amniotic fluid interleukin-6 (IL-6) and C-reactive protein (CRP) levels in the prediction of preterm delivery in singleton pregnancies without any known risk factors for preterm delivery in Turkish women. MATERIALS AND METHODS: Patients in the present perinatology department who underwent mid-trimester genetic amniocentesis due to evidence of increased risk of aneuploidy in their prenatal serum screening tests were included in the study. A sample of amniotic fluid from each patient was assessed for IL-6 and CRP. Concentrations of IL-6 and CRP in the amniotic fluid of preterm delivery and term delivery groups were compared. RESULTS: Of 151 singleton pregnancies, 142 participants were included in the study. The participants were assigned to either the preterm or term delivery group based on pregnancy outcome. IL-6 levels in the amniotic fluid were significantly higher in the preterm delivery group, and there was a statistically significant negative correlation between IL-6 concentrations in the amniotic fluid and gestational age at delivery (correlation coefficient (CC): -18.5%, p < 0.05). A negative correlation was also detected between CRP levels in the amniotic fluid and gestational age at delivery, but the correlation was not statistically significant (p = 0.068). CONCLUSION: Measuring IL-6 in the amniotic fluid can identify women at risk of preterm delivery. Because it is not acceptable to perform amniocentesis for this screening, it is more convenient for patients in whom genetic amniocentesis is performed.


Assuntos
Líquido Amniótico/metabolismo , Proteína C-Reativa/metabolismo , Interleucina-6/metabolismo , Trabalho de Parto Prematuro/diagnóstico , Adolescente , Adulto , Amniocentese , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Pessoa de Meia-Idade , Trabalho de Parto Prematuro/prevenção & controle , Valor Preditivo dos Testes , Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal , Estudos Prospectivos , Fatores de Risco , Sensibilidade e Especificidade , Turquia , Adulto Jovem
12.
Bratisl Lek Listy ; 116(8): 494-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26350090

RESUMO

OBJECTIVE: The effects of Rho-kinase inhibitors on vasodilatation induced by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor rosuvastatin (10-9-10-4M) on 5-HT-precontracted calf cardiac vein and the role of endothelium in these effects were analyzed. MATERIAL AND METHODS: Cardiac vein ring preparations were suspended in organ baths containing 25 ml of Krebs-Henseleit solution, maintained at 37 °C and continuously gassed with 95% O2-5% CO2. At the end of the resting period, the cardiac vein preparations were contracted with 10(-6) M 5-HT. After the contraction had reached a steady state, rosuvastatin was added to the organ bath cumulatively (10(-9)-10(-4) M). RESULTS: Rosuvastatin relaxed the cardiac vein rings in general while the degree of relaxation was greater in those with endothelium and lower in those without it. HA1077 [1-(5-isoquinolinesulfonyl)-homopiperazine] (Fasudil, 10(-6) M) and Y-27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide dihydrochloride] (10(-6) M) incubation increased the rosuvastatin-induced relaxation only in the presence of endothelium. CONCLUSIONS: The results demonstrate for the first time that in calf cardiac vein, rosuvastatin induced endothelium-dependent relaxations while Rho-kinase inhibition increased these relaxations in the presence of endothelium layer (Fig. 3, Ref. 44).


Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , Vasos Coronários/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Rosuvastatina Cálcica/farmacologia , Vasodilatação/efeitos dos fármacos , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Animais , Bovinos , Vasos Coronários/enzimologia , Técnicas In Vitro , Quinases Associadas a rho/antagonistas & inibidores
13.
Exp Physiol ; 99(6): 881-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24681897

RESUMO

There has been a spectacular rise in the global prevalence of type 2 diabetes mellitus (T2DM), and cardiovascular disease is the major cause of morbidity and mortality in diabetic patients. A variety of diastolic and systolic dysfunctions have been demonstrated in type 2 diabetic heart. The consumption of sugar-sweetened beverages has been linked to rising rates of obesity, which in turn is a risk factor for development of T2DM. In this study, the effects of a sucrose-enriched diet on the pattern of gene expression, contraction and Ca(2+) transport in the Goto-Kakizaki T2DM rat heart were investigated. Genes encoding cardiac muscle proteins (Myh7, Mybpc3, Myl1, Myl3 and Mylpf), intercellular proteins (Gja4), cell membrane transport (Atp1b1), calcium channels (Cacna1c, Cacna1g and Cacnb1) and potassium channels (Kcnj11) were upregulated and genes encoding potassium channels (Kcnb1) were downregulated in GK compared with control rats. Genes encoding cardiac muscle proteins (Myh6, Mybpc3 and Tnn2), intercellular proteins (Gja1 and Gja4), intracellular Ca(2+) transport (Atp2a1 and Ryr2), cell membrane transport (Atp1a2 and Atp1b1) and potassium channel proteins (Kcnj2 and Kcnj8) were upregulated and genes encoding cardiac muscle proteins (Myh7) were downregulated in control rats fed sucrose compared with control rats. Genes encoding cardiac muscle proteins (Myh7) and potassium channel proteins (Kcnj11) were downregulated in control and GK rats fed sucrose compared with control and GK rats, respectively. The amplitude of shortening was reduced in myocytes from the control-sucrose group compared with control rats and in the GK-sucrose group compared with GK rats. The amplitude of the Ca(2+) transient was increased in myocytes from control-sucrose compared with control rats and decreased in GK-sucrose compared with GK rats. Subtle alterations in the pattern of expression of genes encoding a variety of cardiac muscle proteins are associated with changes in shortening and intracellular Ca(2+) transport in ventricular myocytes from GK T2DM and control rats fed a sucrose-enriched diet.


Assuntos
Cálcio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Sacarose Alimentar/efeitos adversos , Regulação da Expressão Gênica , Contração Miocárdica/fisiologia , Miócitos Cardíacos/metabolismo , Animais , Transporte Biológico/fisiologia , Células Cultivadas , Diabetes Mellitus Tipo 2/fisiopatologia , Masculino , Ratos , Ratos Wistar
14.
Bratisl Lek Listy ; 115(12): 757-60, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25520223

RESUMO

OBJECTIVE: Preemptive analgesia is an antinociceptive treatment that prevents central sensitization. Antinociceptive effects of diclofenac are well-known. The aim of this study was to investigate preemptive analgesic effects of curcumin and diclofenac, before acute and inflammatory induced pain in rat model. MATERIAL AND METHODS: Fourty eight old female (n = 6 in each group) Wistar Albino rats were included in the study. Paw movements in response to paw flinching in response to formalin injection or thermal stimulation were compared after curcumin (400 mg kg-(1), p.o.) and diclofenac (10 mg kg(-1), i.p.) administration. Saline was used as a control. The solvent ethanol was administered in another group of rats. Preemptive analgesic effect was significant in both tests when curcumin and diclofenac was administrated before the pain stimuli. RESULTS: Oral administration of curcumin and intraperitoneal injection of diclofenac increase the response time in hot plate test and decrease the number of flinches in formalin test (p < 0.001 vs p < 0.05). CONCLUSION: These results suggest that curcumin had preemptive analgesic effects on acute thermal, and inflammatory induced pain in rats as diclofenac (Fig. 2, Ref. 35).


Assuntos
Analgésicos/uso terapêutico , Curcumina/uso terapêutico , Diclofenaco/uso terapêutico , Dor Pós-Operatória/prevenção & controle , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Feminino , Injeções Intraperitoneais , Medição da Dor , Ratos Wistar
15.
Bratisl Lek Listy ; 115(7): 416-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25077364

RESUMO

BACKGROUND: To investigate the effects of exercise preconditioning on oxidative injury in the intestinal tissue of rats. METHODS: Sixty male Wistar rats were randomly divided into six groups as sham (n = 10), ischemia-reperfusion (n = 10), exercise (n = 10), exercise plus ischemia-reperfusion (n = 10), ischemic preconditioning (n = 10), and ischemic preconditioning plus ischemia-reperfusion groups (n = 10). Tissue levels of malondialdehyde and activities of myeloperoxidase and superoxide dismutase, and serum levels of tumor necrosis factor-alpha and interleukin-6 were measured. Intestinal tissue histopathology was also evaluated by light microscopy. RESULTS: Tumor necrosis factor-alpha concentrations significantly decreased in the exercise group compared to the sham group (p < 0.05). Myeloperoxidase activity significantly increased and superoxide dismutase activity significantly decreased in ischemia-reperfusion group compared to the sham group (p < 0.05). Superoxide dismutase activity in the ischemic preconditioning and ischemic preconditioning plus ischemia-reperfusion groups were significantly higher compared to the ischemia-reperfusion and exercise groups (p < 0.05). Histopathologically, intestinal injury significantly attenuated in the exercise plus ischemia-reperfusion group compared to the ischemia-reperfusion group. CONCLUSIONS: The results of the present study indicate that exercise training seems to have a protective role against intestinal ischemia-reperfusion injury (Tab. 3, Fig. 1, Ref. 35).


Assuntos
Intestinos/irrigação sanguínea , Intestinos/patologia , Precondicionamento Isquêmico , Condicionamento Físico Animal/fisiologia , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/fisiopatologia , Animais , Humanos , Interleucina-6/sangue , Intestinos/lesões , Masculino , Malondialdeído/sangue , Estresse Oxidativo/fisiologia , Peroxidase/sangue , Distribuição Aleatória , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Superóxido Dismutase/sangue , Fator de Necrose Tumoral alfa/sangue
16.
Curr Opin Biotechnol ; 88: 103150, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38810302

RESUMO

Nutrient availability and efficient use are critical for crop productivity. Current agricultural practices rely on excessive chemical fertilizers, contributing to greenhouse gas emissions and environmental pollution. Rhizosphere microbes facilitate plant nutrient acquisition and contribute to nutrient use efficiency. Thus, engineering plant-microbe communication within the rhizosphere emerges as a promising and sustainable strategy to enhance agricultural productivity. Recent advances in plant engineering have enabled the development of plants capable of selectively enriching beneficial microbes through root exudates. At the same time, synthetic biology techniques have produced microbes capable of improving nutrient availability and uptake by plants. By engineering plant-microbe communication, researchers aim to harness beneficial soil microbes, thereby offering a targeted and efficient approach to optimizing plant nutrient use efficiency.

17.
J Am Chem Soc ; 135(11): 4398-402, 2013 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-23414346

RESUMO

Though unfunctionalized mesoporous carbon consisting of weakly Brønsted acidic OH-defect sites depolymerizes cellulose under mild conditions, the nature of the active site and how this affects hydrolysis kinetics--the rate-limiting step of this process--has remained a puzzle. Here, in this manuscript, we quantify the effect of surface OH-defect site density during hydrolysis catalysis on the rate of reaction. Our comparative approach relies on synthesis and characterization of grafted poly(1→4-ß-glucan) (ß-glu) strands on alumina. Grafted ß-glu strands on alumina have a 9-fold higher hydrolysis rate per glucan relative to the highest rate measured for ß-glu strands on silica. This amounts to a hydrolysis rate per grafted center on alumina that is 2.7-fold more active than on silica. These data are supported by the lower measured activation energy for hydrolysis of grafted ß-glu strands on alumina being 70 kJ/mol relative to 87 kJ/mol on silica. The observed linear increase of hydrolysis rate with increasing OH-defect site density during catalysis suggests that the formation of hydrogen bonds between weakly Brønsted acidic OH-defect sites and constrained glycosidic oxygens (i.e., those juxtaposed adjacent to the surface) activates the latter for hydrolysis catalysis. Altogether, these data elucidate crucial structural requirements for glucan hydrolysis on surfaces and, when coupled with our recent demonstration of long-chain glucan binding to mesoporous carbon, present a unified picture, for the first time, of adsorbed glucan hydrolysis on OH-defect site-containing surfaces, such as unfunctionalized mesoporous carbon.


Assuntos
Óxido de Alumínio/química , beta-Glucanas/química , Catálise , Ligação de Hidrogênio , Hidrólise , Dióxido de Silício/química , Propriedades de Superfície
18.
Mol Cell Biochem ; 380(1-2): 83-96, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23620341

RESUMO

Although, several novel forms of intervention aiming at newly identified therapeutic targets are currently being developed for diabetes mellitus (DM), it is well established that physical exercise continues to be one of the most valuable forms of non-pharmacological therapy. The aim of the study was to investigate the effects of exercise training on excitation-contraction coupling and related gene expression in the Goto-Kakizaki (GK) type 2 diabetic rat heart and whether exercise is able to reverse diabetes-induced changes in excitation-contraction coupling and gene expression. Experiments were performed in GK and control rats aged 10-11 months following 2-3 months of treadmill exercise training. Shortening, [Ca(2+)]i and L-type Ca(2+) current were measured in ventricular myocytes with video edge detection, fluorescence photometry and whole cell patch clamp techniques, respectively. Expression of mRNA was assessed in ventricular muscle with real-time RT-PCR. Amplitude of shortening, Ca(2+) transients and L-type Ca(2+) current were not significantly altered in ventricular myocytes from GK sedentary compared to control sedentary rats or by exercise training. Expression of mRNA encoding Tpm2, Gja4, Atp1b1, Cacna1g, Cacnb2, Hcn2, Kcna3 and Kcne1 were up-regulated and Gja1, Kcnj2 and Kcnk3 were down-regulated in hearts of sedentary GK rats compared to sedentary controls. Gja1, Cav3 and Kcnk3 were up-regulated and Hcn2 was down-regulated in hearts of exercise trained GK compared to sedentary GK controls. Ventricular myocyte shortening and Ca(2+) transport were generally well preserved despite alterations in the profile of expression of mRNA encoding a variety of cardiac muscle proteins in the adult exercise trained GK diabetic rat heart.


Assuntos
Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Expressão Gênica , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Condicionamento Físico Animal/fisiologia , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/fisiologia , Caveolina 3/genética , Forma Celular , Células Cultivadas , Conexina 43/genética , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Espaço Intracelular , Masculino , Potenciais da Membrana , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Proteínas do Tecido Nervoso/genética , Técnicas de Patch-Clamp , Canais de Potássio de Domínios Poros em Tandem/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Analyst ; 138(15): 4255-9, 2013 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-23730687

RESUMO

In this study, combining the nanoparticle embedded sensors with lateral flow assays, a novel strategy for ensuring the quality of signalling in lateral flow assays (LFAs) was developed. A LFA for reactive oxygen species (ROS) is reported that is based on horse radish peroxidase (HRP) which is co-entrapped with Texas Red dextran inside porous polyacrylamide nanoparticles. In this system, enzymes are protected in the porous matrix of polyacrylamide which freely allows the diffusion of the analyte. The sensor is rapid and sensitive for quantification of hydrogen peroxide concentrations. A test solution of hydrogen peroxides was quantified with this novel LFA-ROS sensor to obtain a linear range between 1 and 25 µM. Nanoparticle embedding of enzymes is proposed here as a general strategy for developing enzyme-based lateral flow assays, eliminating adverse effects associated with biological samples.


Assuntos
Técnicas Biossensoriais/métodos , Peroxidase do Rábano Silvestre/química , Nanopartículas/química , Peroxidase do Rábano Silvestre/análise , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Nanopartículas/análise
20.
Genet Mol Res ; 12(4): 5310-20, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24301792

RESUMO

We conducted SSR analyses of 59 accessions, including 29 traditional plum (Prunus domestica), 24 sweet cherry (Prunus avium), and 1 sour cherry (Prunus cerasus) selected from East Anatolian gene sources and 3 plum and 2 cherry reference accessions for molecular characterization and investigation of genetic relationships. Eight SSR loci [1 developed from the apricot (UDAp-404), 4 from the peach (UDP96-010, UDP96-001, UDP96-019, Pchgms1) and 3 from the cherry (UCD-CH13, UCD-CH17, UCD-CH31) genome] for plum accessions and 9 SSR loci [5 developed from the cherry (PS12A02, UCD-CH13, UCD-CH17, UCD-CH31, UCD-CH21), 3 from the peach (Pchgms1, UDP96-001, UDP96-005) and 1 from the plum (CPSCT010) genome] for cherry accessions were used for genetic identification. A total of 66 and 65 alleles were obtained in the genetic analyses of 31 plum and 28 cherry accessions, respectively. The number of alleles revealed by SSR analysis ranged from 4 to 14 alleles per locus, with a mean value of 8.25 in plum accessions, and from 5 to 10 alleles per locus with a mean value of 7.2 in cherry accessions. Only one case of synonym was identified among the cherry accessions, while no case of synonym was observed among the plum accessions. Genomic SSR markers used in discrimination of plum and cherry accessions showed high cross-species transferability in the Prunus genus. Because of their appreciable polymorphism and cross species transferability, the SSR markers that we evaluated in this study will be useful for studies involving fingerprinting of cherry and plum cultivars.


Assuntos
Loci Gênicos , Repetições de Microssatélites , Prunus/genética , Alelos , Frequência do Gene , Genótipo , Filogenia , Prunus/classificação
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