10 resultados para Magnetite modified by oleic acid
em Repositório da Produção Científica e Intelectual da Unicamp
Resumo:
Valproic acid (VPA) and trichostatin A (TSA) are known histone deacetylase inhibitors (HDACIs) with epigenetic activity that affect chromatin supra-organization, nuclear architecture, and cellular proliferation, particularly in tumor cells. In this study, chromatin remodeling with effects extending to heterochromatic areas was investigated by image analysis in non-transformed NIH 3T3 cells treated for different periods with different doses of VPA and TSA under conditions that indicated no loss of cell viability. Image analysis revealed chromatin decondensation that affected not only euchromatin but also heterochromatin, concomitant with a decreased activity of histone deacetylases and a general increase in histone H3 acetylation. Heterochromatin protein 1-α (HP1-α), identified immunocytochemically, was depleted from the pericentromeric heterochromatin following exposure to both HDACIs. Drastic changes affecting cell proliferation and micronucleation but not alteration in CCND2 expression and in ratios of Bcl-2/Bax expression and cell death occurred following a 48-h exposure of the NIH 3T3 cells particularly in response to higher doses of VPA. Our results demonstrated that even low doses of VPA (0.05 mM) and TSA (10 ng/ml) treatments for 1 h can affect chromatin structure, including that of the heterochromatin areas, in non-transformed cells. HP1-α depletion, probably related to histone demethylation at H3K9me3, in addition to the effect of VPA and TSA on histone H3 acetylation, is induced on NIH 3T3 cells. Despite these facts, alterations in cell proliferation and micronucleation, possibly depending on mitotic spindle defects, require a longer exposure to higher doses of VPA and TSA.
Resumo:
To determine the effects of radiotherapy on salivary BPIFA expression and to investigate the role of BPIFA in the development of known radiotherapy side effects. Unstimulated whole-mouth saliva was collected from 45 cancer patients (1 week before treatment, during the treatment, and 1 week after completion of radiotherapy) and from 20 controls. BPIFA1 and BPIFA2 expression was detected by western blotting and analyzed along with clinicopathologic data and side effects from the radiotherapy. A facial radiation field was associated with lower salivary flow during and after radiotherapy and correlated with side effects, mainly mucositis. Salivary BPIFA1 expression levels were similar between the control group and the patient group before treatment. On the other hand, BPIFA2 levels were higher in the patient group before treatment compared with the control group. BPIFA concentration was modified by radiotherapy as BPIFA1 levels increased (P = .0081) and BPIFA2 decreased (P < .0001). Higher levels of BPIFA1 were associated with the presence of mucositis (P = .0363) and its severity (P = .0500). The present study found that levels of BPIFA1 and glycosylated forms of BPIFA2 are affected by radiotherapy, suggesting that these proteins may play a role in the oral microenvironment in irradiated patients with head and neck cancer.
Resumo:
Recent data suggests that cholesteryl ester transfer protein (CETP) activity may interact with acute stress conditions via inflammatory-oxidative response and thrombogenesis. We investigated this assumption in patients with ST-elevation myocardial infarction (STEMI). Consecutive patients with STEMI (n = 116) were enrolled <24-h of symptoms onset and were followed for 180 days. Plasma levels of C-reactive protein (CRP), interleukin-2 (IL-2), tumor necrosis factor (TNFα), 8-isoprostane, nitric oxide (NOx) and CETP activity were measured at enrollment (D1) and at fifth day (D5). Flow-mediated dilation (FMD) was assessed by ultrasound and coronary thrombus burden (CTB) was evaluated by angiography. Neither baseline nor the change of CETP activity from D1 to D5 was associated with CRP, IL-2, TNFα, 8-isoprostane levels or CTB. The rise in NOx from D1 to D5 was inferior [3.5(-1; 10) vs. 5.5(-1; 12); p < 0.001] and FMD was lower [5.9(5.5) vs. 9.6(6.6); p = 0.047] in patients with baseline CETP activity above the median value than in their counterparts. Oxidized HDL was measured by thiobarbituric acid reactive substances (TBARS) in isolated HDL particles and increased from D1 to D5, and remaining elevated at D30. The change in TBARS content in HDL was associated with CETP activity (r = 0.72; p = 0.014) and FMD (r = -0.61; p = 0.046). High CETP activity at admission was associated with the incidence of sudden death and recurrent MI at 30 days (OR 12.8; 95% CI 1.25-132; p = 0.032) and 180 days (OR 3.3; 95% CI 1.03-10.7; p = 0.044). An enhanced CETP activity during acute phase of STEMI is independently associated with endothelial dysfunction and adverse clinical outcome.
Resumo:
To assess the value of vaginal screening cytology after hysterectomy for benign disease. This cross-sectional study used cytology audit data from 2,512,039 screening tests in the metropolitan region of Campinas from 2000 to 2012; the object was to compare the prevalence of abnormal tests in women who had undergone a hysterectomy for benign diseases (n=53,891) to that of women who had had no hysterectomy. Prevalence ratios (95% confidence intervals, 95% CI) were determined, and chi-square analysis, modified by the Cochrane-Armitage test for trend, was used to investigate the effects of age. The prevalence of atypical squamous cells (ASC), low-grade squamous intraepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion or squamous-cell carcinoma (HSIL/SCC) was 0.13%, 0.04% and 0.03%, respectively, in women who had undergone hysterectomy, and 0.93%, 0.51% and 0.26% in women who had not undergone hysterectomy. The prevalence ratios for ASC, LSIL and HSIL/SCC were 0.14 (0.11-0.17), 0.08 (0.06-0.13) and 0.13 (0.08-0.20), respectively, in women with a hysterectomy versus those without. For HSIL/SCC, the prevalence ratios were 0.09 and 0.29, respectively, for women <50 or ≥50years. The prevalence rates in women with a previous hysterectomy showed no significant variation with age. The prevalence rates of ASC, LSIL and HSIL/SCC were significantly lower in women with a previous hysterectomy for benign disease compared with those observed in women with an intact uterine cervix. This study reinforces the view that there is no evidence that cytological screening is beneficial for women who have had a hysterectomy for benign disease.
Resumo:
The recombinant Rhizopus oryzae lipase (1-3 positional selective), immobilized on Relizyme OD403, has been applied to the production of biodiesel using single cell oil from Candida sp. LEB-M3 growing on glycerol from biodiesel process. The composition of microbial oil is quite similar in terms of saponifiable lipids than olive oil, although with a higher amount of saturated fatty acids. The reaction was carried out in a solvent system, and n-hexane showed the best performance in terms of yield and easy recovery. The strategy selected for acyl acceptor addition was a stepwise methanol addition using crude and neutralized single cell oil, olive oil and oleic acid as substrates. A FAMEs yield of 40.6% was obtained with microbial oils lower than olive oil 54.3%. Finally in terms of stability, only a lost about 30% after 6 reutilizations were achieved.
Resumo:
The interactions of carbon nanotubes with pesticides, such as carbofuran, classical contaminants (e.g., pesticides, polyaromatic hydrocarbons, heavy metals, and dyes) and emerging contaminants, including endocrine disruptors, are critical components of the environmental risks of this important class of carbon-based nanomaterials. In this work, we studied the modulation of acute carbofuran toxicity to the freshwater fish Nile tilapia (Oreochromis niloticus) by nitric acid treated multiwalled carbon nanotubes, termed HNO3-MWCNT. Nitric acid oxidation is a common chemical method employed for the purification, functionalisation and aqueous dispersion of carbon nanotubes. HNO3-MWCNT were not toxic to Nile tilapia at concentrations ranging from 0.1 to 3.0 mg/L for exposure times of up to 96 h. After 24, 48, 72 and 96 h, the LC50 values of carbofuran were 4.0, 3.2, 3.0 and 2.4 mg/mL, respectively. To evaluate the influence of carbofuran-nanotube interactions on ecotoxicity, we exposed the Nile tilapia to different concentrations of carbofuran mixed together with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, and 96 h of exposure, the LC50 values of carbofuran plus nanotubes were 3.7, 1.6, 0.7 and 0.5 mg/L, respectively. These results demonstrate that HNO3-MWCNT potentiate the acute toxicity of carbofuran, leading to a more than five-fold increase in the LC50 values. Furthermore, the exposure of Nile tilapia to carbofuran plus nanotubes led to decreases in both oxygen consumption and swimming capacity compared to the control. These findings indicate that carbon nanotubes could act as pesticide carriers affecting fish survival, metabolism and behaviour.
Resumo:
The durability of the cellulose-cement composites is a decisive factor to introduce such material in the market. Polymers have been used in concrete and mortar production to increase its durability. The goal of this work was the physical and mechanical characterization of cellulose-cement composites modified by a polymer and the subsequent durability evaluation. The work also evaluated the dispersion of acrylic polymer in composites made of Pinus caribaea residues. The physical properties observed were water absorption by immersion and bulk density. Rupture modulus and toughness were determined by flexural test. The specimens were obtained from pads, produced by pressing and wet curing. Samples were subjected to accelerated aging tests by repeated wetting and drying cycles and hot-water bath and natural aging. The scanning electron microscopy (SEM) allowed verifying the fiber and composite characteristics along the time. For the composite range analyzed, it was observed the polymer improved the mechanical properties of composites besides a significant decreasing in water absorption. The use of polymer improved the performance of vegetable fiber-cement composites when compared to the conventional mortar, due to water absorption decreasing.
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação Física
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação Física
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação Física