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The renin-angiotensin (Ang) system (RAS) is a complex hormonal system present locally in several tissues such as cardiovascular organs. RAS deregulation through overactivation of the classical arm [Ang-converting enzyme (ACE)/Ang-II/Ang type 1 receptor (AT1R)] has been linked to the development of cardiovascular diseases and activation of endoplasmic reticulum (ER) stress pathways. The ER stress is a condition that, if unresolved, might lead to heart failure, atherosclerosis, hypertension, and endothelial dysfunction. Accumulated evidence has shown that the RAS modulates the UPR activation. Several studies reported increased ER stress markers in response to Ang-II treatment, in both in vivo and in vitro models. Evidence has also pointed that targeting the RAS classical arm through RAS blockers, gene silencing or genetic models leads to lower levels of ER stress markers. Few studies demonstrated protective effects of the counter-regulatory arm (ACE-2/Ang-(1-7)/Mas receptor) over ER stress. However, the crosstalk mechanisms between the arms of the RAS and ER stress remain unclear. In this review, we sought to explore the classical arm of the RAS as a key mechanism in UPR activation and to suggest a possible protective role of the counter-regulatory arm in mitigating ER stress., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Plasma membrane repair (PMR) is an important process for cell homeostasis, especially for cells under constant physical stress. Repair involves a sequence of Ca 2+ -dependent events, including lysosomal exocytosis and subsequent compensatory endocytosis. Cholesterol sequestration from plasma membrane causes actin cytoskeleton reorganization and polymerization, increasing cell stiffness, which leads to exocytosis and reduction of a peripheral pool of lysosomes involved in PMR. These changes in mechanical properties are similar to those observed in cells exposed to oxidized Low Density Lipoprotein (oxLDL), a key molecule during atherosclerosis development. Using a human umbilical vein endothelial cell line (EAhY926) we evaluated the influence of mechanical modulation induced by oxLDL in PMR and its effect in endothelial fragility. Similar to MβCD (a drug capable of sequestering cholesterol) treatment, oxLDL exposure led to actin reorganization and de novo polymerization, as well as an increase in cell rigidity and lysosomal exocytosis. Additionally, for both MβCD and oxLDL treated cells, there was an initial increase in endocytic events, likely triggered by the peak of exocytosis induced by both treatments. However, no further endocytic events were observed, suggesting that constitutive endocytosis is blocked upon treatment and that the reorganized cytoskeleton function as a mechanical barrier to membrane traffic. Finally, the increase in cell rigidity renders cells more prone to mechanical injury. Together, these data show that mechanical modulation induced by oxLDL exposure not only alters membrane traffic in cells, but also makes them more susceptible to mechanical injury, which may likely contribute to the initial steps of atherosclerosis development., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Recently, the scientific community became aware of the potential ability of nanoparticles to cause toxicity in living organisms. Therefore, many of the implications for aquatic ecosystems and its effects on living organisms are still to be evaluated and fully understood. In this study, the toxicity of nanodiamonds (NDs) was assessed in the freshwater bivalve (Corbicula fluminea) following exposure to different nominal concentrations of NDs (0.01, 0.1, 1, and 10 mg l(-1)) throughout 14 days. The NDs were characterized (gravimetry, pH, zeta potential, electron microscopy, and atomic force microscopy) confirming manufacturer information and showing NDs with a size of 4-6 nm. Oxidative stress enzymes activities (glutathione-S-transferase, catalase) and lipid peroxidation were determined. The results show a trend to increase in GST activities after seven days of exposure in bivalves exposed to NDs concentrations (>0.1 mg l(-1)), while for catalase a significant increase was found in bivalves exposed from 0.01 to 1.0 mg l(-1) following an exposure of 14 days. The histological analysis revealed alterations in digestive gland cells, such as vacuolization and thickening. The lipid peroxidation showed a trend to increase for the different tested NDs concentrations which is compatible with the observed cellular damage., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Oral bacteria have been detected in atherosclerotic plaques at a variable frequency; however, the connection between oral health and vascular and oral bacterial profiles of patients with vascular disease is not clearly established. The aim of this study was to evaluate the presence of oral bacterial DNA in the mouth and atherosclerotic plaques, in addition to assessing the patients' caries and periodontal disease history., Methods: Thirty samples of supragingival and subgingival plaque, saliva and atherosclerotic plaques of 13 patients with carotid stenosis or aortic aneurysm were evaluated, through real-time polymerase chain reaction, for the presence of Streptococcus mutans (SM), Prevotella intermedia (PI), Porphyromonas gingivalis (PG) and Treponema denticola (TD). All patients were submitted to oral examination using the DMFT (decayed, missing and filled teeth) and PSR (Periodontal Screening and Recording) indexes. Histopathological analysis of the atherosclerotic plaques was performed., Results: Most of the patients were edentulous (76.9%). SM, PI, PG and TD were detected in 100.0%, 92.0%, 15.3% and 30.7% of the oral samples, respectively. SM was the most prevalent targeted bacteria in atherosclerotic plaques, detected in 100% of the samples, followed by PI (7.1%). The vascular samples were negative for PG and TD. There was a statistically significant difference (p<0.05) between the presence of PG and TD in the oral cavity and vascular samples., Conclusion: SM was found at a high frequency in oral and vascular samples, even in edentulous patients, and its presence in atherosclerotic plaques suggests the possible involvement of this bacterium in the disease progression., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Chitosan-montmorillonite (KSF-CTS) beads were prepared by crosslinking with pentasodium tripolyphosphate (TPP). Montmorillonite (KSF-Na), CTS and KSF-CTS biocomposite were used to remove Cu(II) from aqueous solutions. These materials were characterized before and after copper adsorption by XRD, FTIR and thermogravimetry (TG). The data indicated that the adsorption process proceeds kinetically according to a pseudo-second-order model. The adsorption processes were adjusted to the Langmuir model for KSF-Na and CTS and to the Temkin model for KSF-CTS. The maximum adsorption capacity followed the order CTS>KSF-CTS>KSF-Na. Percentages desorption of copper ions from the KSF-CTS composite after three desorption cycles were 86%, 85% and 84%, respectively, using EDTA as regeneration agents., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Aim: The aim of this study was to determine the antimetastatic potential of biflorin using in vivo and in vitro approaches., Main Methods: Biflorin was isolated from Capraria biflora collected in Fortaleza, Ceará, Brazil. Adhesion, migration and invasion assays were performed to avail of the antimetastatic potential of this quinone. Experimental metastasis was performed to avail of the antimetastatic potential of bilflorin using in vivo assay., Key Findings: Treatment with biflorin (25 and 50mg/kg/day) was shown to be effective in reducing B16-F10 melanoma metastasis in C57BL/6 mice. The administration of biflorin at 25mg/kg/day intraperitoneally inhibited the formation of metastases by about 57% compared to untreated control animals. When the animals were treated with 50mg/kg/day intraperitoneally, there was a 71% decrease in the number of lung metastases. Morphological assays showed the presence of hemosiderin and erythrocytes in the lung parenchyma, indicating the occurrence of hemorrhage, probably a side effect of biflorin. Biflorin at non-toxic concentrations (0.5, 1.0 and 1.5g/mL) was tested directly on B16-F10 cells in vitro, and it inhibited cell adhesion to type I collagen and cell motility using the wound-healing assay., Significance: These data suggest that biflorin has a promising antimetastatic potential, as shown by its anti-adhesion, anti-migration and anti-invasion properties against a metastatic melanoma cell line. However, further studies are essential to elucidate its mechanism of action., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Primary cardiac angiosarcoma is an extremely rare malignant tumor. Distant metastases are common at the time of diagnosis but have never been reported in the jaw. A 45-year-old female patient with primary cardiac angiosarcoma was referred for dental care due to pain in the mandibular alveolar ridge. Oral examination revealed a red-violet lesion that was soft on palpation and had been present for 3 months. Histological analysis confirmed the diagnosis of metastatic cardiac angiosarcoma. The patient died of multiple metastases., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The present study evaluated microstructure, microhardness and wear resistance of experimental titanium alloys containing zirconium and tantalum. Alloys were melted in arc melting furnace according to the following compositions: Ti-5Zr, Ti-5Ta and Ti-5Ta-5Zr (%wt). Hemispheres and disks were obtained from wax patterns that were invested and cast by plasma. Microstructures were evaluated using optical microscopy and X-ray diffraction (XRD) analysis and also Vickers microhardness was measured. Hemispherical samples and disks were used for 2-body wear tests, performed by repeated grinding of the samples. Wear resistance was assessed as height loss after 40,000 cycles. The data were compared using ANOVA and post-hoc Tukey test. Ti-5Zr presented a Widmanstätten structure and the identified phases were α and α' while Ti-5Ta and Ti-5Ta-5Zr presented α, β, α' and α" phases, but the former presented a lamellar structure, and the other, acicular. The microhardness of Ti-5Zr was significantly greater than other materials and cp Ti presented wear resistance significantly lower than experimental alloys. It was concluded that wear resistance was improved when adding Ta and Zr to titanium and Zr increased microhardness of Ti-5Zr alloy., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: The objective of this study was to analyze the frequency and distribution of odontogenic tumors in Fortaleza, Brazil, and compare the findings with those reported in the literature., Study Design: A total of 6231 oral lesions retrieved from 5 anatomic pathology services in Fortaleza, Brazil, over a 5-year period, were reviewed. In addition, the literature was searched for studies on odontogenic tumors (OTs) according to the 2005 WHO classification., Results: Within the total 6231 oral lesions, 185 (2.97%) were OTs, all benign. OTs presented a female predilection, with a male:female ratio of 0.62:1.00. These neoplasms occurred over a wide range of ages (1 to 78 years), with a mean of 30.5 years. Ameloblastomas, keratocystic odontogenic tumors, and odontomas were the most frequent OT types., Conclusions: OTs are rare neoplasms and appear to show geographic variations. In Fortaleza, Brazil, they are more common in female patients, with ameloblastoma followed by keratocystic odontogenic tumors as the most frequent OTs., (Copyright © 2011 Mosby, Inc. All rights reserved.)

The cytotoxicity of nine naphthoquinones (NQ) was assayed against HL-60 (leukaemia), MDA-MB-435 (melanoma), SF-295 (brain) and HCT-8 (colon), all human cancer cell lines, and peripheral blood mononuclear cells (PBMC), as representatives of normal cells, after 72h of incubation. 5-Methoxy-1,4-naphthoquinone was the most active compound, showing IC(50) values in the range of 0.31 (1.7microM) in HL-60 to 0.88microg/mL (4.7microM) in SF-295 and IC(50) of 0.69microg/mL (3.7microM) against PBMC. With the introduction of a bromo-substituent in position 2 or 3 of juglone, the IC(50) significantly decreased, regardless of the position on the NQ moiety. However, compared with juglone methyl ether, the halogen substitution decreased the activity. To further understand the mechanism underlying the cytotoxicity of 5-methoxy-1,4-naphthoquinone, studies involving DNA fragmentation, cell cycle analysis, phosphatidyl serine externalization, mitochondrial depolarization and activation of caspases 8 and 3/7 were performed in HL-60 cell line, using doxorubicin as a positive control. The results indicate that the cytotoxic 5-methoxy-1,4-naphthoquinone activates caspases 8 and 3/7 and thus induces apoptosis independent of mitochondria.

Withaphysalins are C(28)-steroidal lactones structurally based on the ergostane skeleton that possess antiproliferative activity against tumor cell lines. In the present study, the antileukemic actvity of withaphysalin O (1), M (2), and N (3) isolated from Acnistus arborescens, against two leukemic cell lines, HL-60 and K562, was evaluated, and the cytotoxicity compared with the effects on peripheral blood mononuclear cells (PBMC). All tested compounds reduced the number of viable cells of the tumor cell lines after 24 h of exposure, except for compound 2 against the K562 cell line. The reduction was time-and concentration-dependent, and the IC(50) values ranged from 0.7 to 3.5 microM after 72 h of incubation. In addition to the growth inhibitory properties, the drugs decreased DNA synthesis after 24 h of drug exposure evaluated by the 5-bromo-2 -deoxyuridine incorporation method. None of the tested compounds reduced the number of PBMC (IC(50)>20 microM) after 72 h of incubation, in contrast to doxorubicin that decreased viable cells and increased non-viable cells even after 24 h of incubation. Morphological analysis of treated cells using hematoxylin/eosin staining indicated the presence of necrotic cells for all tested compounds in HL-60, confirmed by the use of acridine orange/ethidium bromide staining. In addition to necrotic cells, K562 cells showed morphological alterations consistent with apoptosis.

An on-line system for preconcentration and determination of copper at mug l(-1) level by flame atomic absorption spectrometry (FAAS) is proposed. Amberlite XAD-2 functionalized with 3,4-dihydroxybenzoic acid packed in a minicolumn was used as sorbent. Copper(II) ions were sorbed in the minicolumn, from which it could be eluted by hydrochloric acid solution directly to the nebulizer-burner system of the FAAS. Eluent solution was carried by water at a flow rate of 5.00 ml min(-1). Signals were measured as peak height by using an instrument software. Achieved sampling rate was 27 samples per hour. Analytical parameters were evaluated and the results demonstrated that copper can be determined, with acetate buffer to adjust the sample pH at 6.0, preconcentration time of 120 s and a sample flow rate of 6.50 ml min(-1). The desorption was carried out with 30 mul of a 1.0 mol l(-1) hydrochloric acid solution. An enrichment factor of 33 in 13.00 ml of sample (120 s preconcentration time) was achieved by using the time-based technique. The detection limit (DL) (3 s) was 0.27 mug l(-1) and the precision (assessed as the relative standard deviation) reached values of 5.7-1.1% in copper solutions of 5.00 to 50.00 mug l(-1) concentration, respectively. The accuracy of procedure was confirmed by copper determination in certified reference materials. Recoveries of spike additions (1.0 or 2.0 mug g(-1)) to food samples were quantitative (90.0-110.0%). These results proved also that the procedure is not affected by matrix interference and can be applied satisfactorily for copper determination in rice flour and starch samples.