Publications by authors named "Fernanda Visioli"

70 Publications

The brief methylprednisolone administration is crucial to mitigate cardiac dysfunction after myocardial infarction.

An Acad Bras Cienc 2021 22;93(suppl 4):e20210297. Epub 2021 Oct 22.

Universidade Federal do Rio Grande do Sul, Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, R. Sarmento Leite, 500, 90050-170 Porto Alegre, RS, Brazil.

Acute myocardial infarction (AMI) is one of the major causes of heart failure and mortality. Glucocorticoids administration post-infarction has long been proposed, but it has shown conflicting results so far. This controversy may be associated with the glucocorticoid type and the period when it is administered. To elucidate these, the present aims to evaluate if the brief methylprednisolone acetate administration is determinant for heart adaptation after AMI. Male Wistar rats were divided into 3 groups: sham-operated (SHAM); infarcted (AMI); infarcted treated with methylprednisolone acetate (AMI+M). Immediately after surgery, the AMI+M group received a single dose of methylprednisolone acetate (40 mg/kg i.m.). After 56 days, the cardiac function was assessed and lungs, liver and heart were collected to determine rates of hypertrophy and congestion. Heart was used for oxidative stress and metalloproteinase activity analyses. Methylprednisolone acetate attenuated matrix metalloproteinase-2 activity, cardiac dilatation, and prevented the onset of pulmonary congestion, as well as avoided cardiac hypertrophy. Our data indicate that administration of methylprednisolone acetate shortly after AMI may be a therapeutic alternative for attenuation of detrimental ventricular remodeling.
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http://dx.doi.org/10.1590/0001-3765202120210297DOI Listing
October 2021

Physicochemical and biological evaluation of a triazine-methacrylate monomer into a dental resin.

J Dent 2021 Sep 21;114:103818. Epub 2021 Sep 21.

Department of Dental Materials, School of Dentistry, Federal University of Rio Grande do Sul. Ramiro Barcelos Street, 2492, Rio Branco, 90035-003, Porto Alegre, RS, Brazil. Electronic address:

Objectives: This study aimed to (1) formulate blend resins with 2.5 or 5 wt.% of the methacrylate monomer 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT), and (2) to evaluate the blend resins regarding the physicochemical and biological properties.

Methods: The base resin was formulated mixing 60 wt.% of bisphenol A glycol dimethacrylate and 40 wt.% of triethylene glycol dimethacrylate with photoinitiator/co/initiator system. TAT was added at 2.5 (G) or 5 (G) wt.%, and a group without TAT was used as control (G). The resins were analyzed for degree of conversion (DC), Knoop hardness (KHN), softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle, surface free energy (SFE), antibacterial activity against Streptococcus mutans biofilm formation, and cytotoxicity against human keratinocytes.

Results: There was no difference for the DC (p = 0.676). The addition of TAT at 5 wt.% induced higher KHN (p<0.001), higher resistance against softening in solvent (p<0.001), and higher UTS (p = 0.04). There were no statistically significant differences for contact angle with water (p = 0.106), α-bromonaphtalene (p = 0.454), and SFE (p = 0.172). The higher the TAT concentration, the higher the antibacterial activity (p<0.001). G showed no cytotoxicity compared to G (p>0.05), and G induced lower cell viability (p<0.05).

Conclusions: The addition of 2.5 wt.% of TAT is suitable for conveying antibacterial activity for dental resins without changing the physicochemical properties or impairing the cytotoxic effect.

Clinical Relevance: Methacrylate monomers that decrease bacterial viability and copolymerize with the resin matrix are exciting approaches to developing therapeutic materials. TAT showed promising properties to may hamper and prevent carious lesions when incorporated into dental materials. Further evaluations with higher cariogenic challenges will be carried to analyze the formulated materials.
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http://dx.doi.org/10.1016/j.jdent.2021.103818DOI Listing
September 2021

Thioredoxin system activation is associated with the progression of experimental pulmonary arterial hypertension.

Life Sci 2021 Nov 31;284:119917. Epub 2021 Aug 31.

Laboratory of Cardiovascular Physiology and Reactive Oxygen Species, Physiology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. Electronic address:

In addition to being an antioxidant, thioredoxin (Trx) is known to stimulate signaling pathways involved in cell proliferation and to inhibit apoptosis. The aim of this study was to explore the role of Trx in some of these pathways along the progression of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male rats were first divided into two groups: monocrotaline (MCT - 60 mg/kg i.p.) and control (received saline), that were further divided into three groups: 1, 2, and 3 weeks. Animals were submitted to echocardiographic analysis. Right and left ventricles were used for the measurement of hypertrophy, through morphometric and histological analysis. The lung was prepared for biochemical and molecular analysis. One week after MCT injection, there was an increase in thioredoxin reductase (TrxR) activity, a reduction in glutathione reductase (GR) activity, and an increase in Trx-1 and vitamin D3 up-regulated protein-1 (VDUP-1) expression. Two weeks after MCT injection, there was an increase in VDUP-1, Akt and cleaved caspase-3 activation, and a decrease in Trx-1 and Nrf2 expression. PAH-induced by MCT promoted a reduction in Nrf2 and Trx-1 expression as well as an increase in Akt and VDUP-1 expression after three weeks. The increase in pulmonary vascular resistance was accompanied by increased TrxR activity, suggesting an association between the Trx system and functional changes in the progression of PAH. It seems that Trx-1 activation was an adaptive response to MCT administration to cope with pulmonary remodeling and disease progression, suggesting a potential new target for PAH therapeutics.
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http://dx.doi.org/10.1016/j.lfs.2021.119917DOI Listing
November 2021

Efficacy of topical non-steroidal immunomodulators in the treatment of oral lichen planus: a systematic review and meta-analysis.

Clin Oral Investig 2021 Sep 3;25(9):5149-5169. Epub 2021 Aug 3.

Oral Pathology and Oral Medicine Department, School of Dentistry, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Porto Alegre, RS, 90035-003, Brazil.

Objectives: The aim of this systematic review was to assess the efficacy and safety of topical non-steroidal immunomodulators (TNSIs) for oral lichen planus (OLP) treatment.

Materials And Methods: A search strategy designed for this purpose retrieved 1156 references. After analysis of titles and abstracts, 75 studies were selected for full-text analysis. Only randomized controlled clinical trials were selected, resulting in 28 studies included for qualitative and quantitative analysis.

Results: The meta-analysis showed similar benefits in clinical response and symptom resolution between tacrolimus 0.1% and pimecrolimus 1% in comparison to topical steroids (TS). Pimecrolimus showed superior efficacy of clinical response but not for symptom resolution compared to placebo. Tacrolimus and pimecrolimus showed better performance preventing symptom relapse, while pimecrolimus also prevented clinical relapse better than TS. Cyclosporine was superior to placebo; however, TS showed better efficacy of clinical response. Thalidomide and retinoid were assessed in only one trial each, and both showed similar efficacy to TS. Rapamycin also presented similar clinical response to TS; however, the later showed greater reduction of symptoms. Mycophenolate mofetil 2% mucoadhesive was no better than placebo. No serious adverse effects have been reported. Cyclosporine showed a higher frequency and variety of adverse effects.

Conclusions: Topical tacrolimus and pimecrolimus are safe and effective alternatives for OLP treatment.

Clinical Relevance: TS are usually the first choice for OLP treatment. Because some oral lesions may have a low response to treatment with TS, more topical therapeutic options, such as TNSIs, should be considered before systemic steroids are used.
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http://dx.doi.org/10.1007/s00784-021-04072-7DOI Listing
September 2021

EGFRvIII peptide nanocapsules and bevacizumab nanocapsules: a nose-to-brain multitarget approach against glioblastoma.

Nanomedicine (Lond) 2021 08 27;16(20):1775-1790. Epub 2021 Jul 27.

Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, Porto Alegre, RS 90610-000, Brazil.

To evaluate the antitumor efficacy of bevacizumab-functionalized nanocapsules in a rat glioblastoma model after the pretreatment with nanocapsules functionalized with a peptide-specific to the epidermal growth factor receptor variant III. Nanocapsules were prepared, physicochemical characterized and intranasally administered to rats. Parameters such as tumor size, histopathological characteristics and infiltration of CD8 T lymphocytes were evaluated. The strategy of treatment resulted in a reduction of 87% in the tumor size compared with the control group and a higher infiltration of CD8 T lymphocytes in tumoral tissue. The block of two different molecular targets using nose-to-brain delivery represents a new and promising approach against glioblastoma.
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http://dx.doi.org/10.2217/nnm-2021-0169DOI Listing
August 2021

Polybutylene-adipate-terephthalate and niobium-containing bioactive glasses composites: Development of barrier membranes with adjusted properties for guided bone regeneration.

Mater Sci Eng C Mater Biol Appl 2021 Jun 19;125:112115. Epub 2021 Apr 19.

Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address:

This study aimed to develop bioactive guided bone regeneration (GBR) membranes by manufacturing PBAT/BAGNb composites as casting films. Composites were produced by melt-extrusion, and BAGNb was added at 10 wt%, 20 wt%, and 30 wt% concentration. Pure PBAT membranes were used as a control (0wt%BAGNb). FTIR and thermogravimetric analysis characterized the composites. Barrier membranes were produced by solvent casting, and their mechanical and surface properties were assessed by tensile strength test and contact angle analysis, respectively. The ion release and cell behavior were evaluated by pH, cell proliferation, and mineralization. Composites were successfully produced, and the chemical structure showed no interference of BAGNb in the PBAT structure. The addition of BAGNb increased the stiffness of the membranes and reduced the contact angle, increasing the roughness in one side of the membrane. Sustained pH increment was observed for BAGNb-containing membranes with increased proliferation and mineralization as the concentration of BAGNb increases. The incorporation of up to 30 wt% of BAGNb into PBAT barrier membranes was able to maintain adequate chemical-mechanical properties leading to the production of materials with tailored surface properties and bioactivity. Finally, this biomaterial class showed outstanding potential and may contribute to bone formation in GBR procedures.
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http://dx.doi.org/10.1016/j.msec.2021.112115DOI Listing
June 2021

The paradox of autophagy in Tuberous Sclerosis Complex.

Genet Mol Biol 2021 5;44(2):e20200014. Epub 2021 Apr 5.

Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.
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http://dx.doi.org/10.1590/1678-4685-GMB-2020-0014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8022228PMC
April 2021

Ionic liquid-loaded microcapsules doped into dental resin infiltrants.

Bioact Mater 2021 Sep 12;6(9):2667-2675. Epub 2021 Feb 12.

Department of Dental Materials, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, 90035-003, Porto Alegre, RS, Brazil.

Resin infiltrants have been effectively applied in dentistry to manage non-cavitated carious lesions in proximal dental surfaces. However, the common formulations are composed of inert methacrylate monomers. In this study, we developed a novel resin infiltrant with microcapsules loaded with an ionic liquid (MC-IL), and analyzed the physical properties and cytotoxicity of the dental resin. First, the ionic liquid 1--butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf) was synthesized. BMI.NTf has previously shown antibacterial activity in a dental resin. Then, MC-IL were synthesized by the deposition of a preformed polymer. The MC-IL were analyzed for particle size and de-agglomeration effect via laser diffraction analysis and shape via scanning electron microscopy (SEM). The infiltrants were formulated, and the MC-IL were incorporated at 2.5%, 5%, and 10 wt%. A group without MC-IL was used as a control. The infiltrants were evaluated for ultimate tensile strength (UTS), contact angle, surface free energy (SFE), and cytotoxicity. The MC-IL showed a mean particle size of 1.64 (±0.08) μm, shriveled aspect, and a de-agglomeration profile suggestive of nanoparticles' presence in the synthesized powder. There were no differences in UTS among groups (p > 0.05). The incorporation of 10 wt% of MC-IL increased the contact angle (p < 0.05), while the addition from 5 wt% reduced the SFE in comparison to the control group (p < 0.05). The human cell viability was above 90% for all groups (p > 0.05). The incorporation of microcapsules as a drug-delivery system for ionic liquids may be a promising strategy to improve dental restorative materials.
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http://dx.doi.org/10.1016/j.bioactmat.2021.02.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7895677PMC
September 2021

Titanium dioxide nanotubes with triazine-methacrylate monomer to improve physicochemical and biological properties of adhesives.

Dent Mater 2021 02 24;37(2):223-235. Epub 2020 Nov 24.

Dental Materials Department, School of Dentistry, Federal University of Rio Grande do Sul. Ramiro Barcelos Street, 2492, Rio Branco, 90035-003, Porto Alegre, RS, Brazil. Electronic address:

Objective: Formulate experimental adhesives containing titanium dioxide nanotubes (nt-TiO) or titanium dioxide nanotubes with a triazine-methacrylate monomer (nt-TiO:TAT) and evaluate the effect of these fillers on the physical, chemical, and biological properties of the adhesives.

Methods: First, nt-TiO were synthesized via a hydrothermal method. The nt-TiO were mixed with a triazine-methacrylate monomer (TAT) to formulate nt-TiO:TAT, which were characterized by transmission electron microscopy (TEM). The nt-TiO, TAT, and nt-TiO:TAT were evaluated via Fourier Transform Infrared, Ultraviolet-visible, and micro-Raman spectroscopies. An experimental adhesive resin was formulated with bisphenol A glycerolate dimethacrylates, 2-hydroxyethyl methacrylate, and photoinitiator/co-initiator system. nt-TiO or nt-TiO:TAT were incorporated at 2.5 wt.% and 5 wt.% in the adhesive. The base resin without nt-TiO or nt-TiO:TAT was used as a control group. The adhesives were evaluated for antibacterial activity, cytotoxicity, polymerization kinetics, degree of conversion (DC), Knoop hardness, softening in solvent (ΔKHN%), ultimate tensile strength (UTS), 24 h- and 1 year- microtensile bond strength (μ-TBS).

Results: TEM confirmed the nanotubular morphology of TiO. FTIR, UV-vis, and micro-Raman analyses showed the characteristic peaks of each material, indicating the impregnation of TAT in the nt-TiO. Adhesives with nt-TiO:TAT showed antimicrobial activity against biofilm formation compared to control (p < 0.05), without differences in the viability of planktonic bacteria (p > 0.05). All groups showed high percentages of pulp cell viability. The polymerization kinetics varied among groups, but all presented DC above 50%. The addition of 5 wt.% of nt-TiO and both groups containing nt-TiO:TAT showed higher values ​​of Knoop hardness compared to the control (p < 0.05). The groups with nt-TiO:TAT presented lower ΔKHN% (p < 0.05) and higher UTS (p < 0.05) than the control group. After one year, the group with 5 wt.% of nt-TiO, as well as both groups containing nt-TiO:TAT, showed higher μ-TBS than the control (p < 0.05).

Significance: The mixing of a triazine-methacrylate monomer with the nt-TiO generated a filler that improved the physicochemical properties of the adhesive resins and provided antibacterial activity, which could assist in preventing carious lesions around tooth-resin interfaces. The set of physical, chemical, and biological properties of the formulated polymer, together with the greater stability of the bond strength over time, make nt-TiO:TAT a promising filler for dental adhesive resins.
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http://dx.doi.org/10.1016/j.dental.2020.11.004DOI Listing
February 2021

Periodontal condition and treatment in a patient with rare systemic condition: A case report for acid sphingomyelinase deficiency.

Spec Care Dentist 2021 Jan 12;41(1):103-110. Epub 2020 Nov 12.

Department of Conservative Dentistry - Periodontology, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Background: Acid sphingomyelinase deficiency (ASMD) is a rare group of autosomal recessive disorders. This report provides the first detailed description of the periodontal condition and treatment response in a patient with chronic visceral ASMD.

Case Description: A 49-year-old white woman with ASMD showed elevated visible plaque index (VPI), gingival bleeding index (GBI), and bleeding on probing (BOP) at 100% of sites. Periodontal pocket depths (PPD) were mostly shallow to moderate (at 96% of sites), whereas the loss of clinical attachment (CAL) was moderate to severe (54% and 46% of sites, respectively, at 4-6 mm and ≥7 mm categories). Periapical radiographs revealed the presence of furcation involvement and intra-bony defects. The periodontal diagnosis was periodontitis stage IV, generalized, grade C. Ninety days after the end of the supra and subgingival control (e.g., cause-related therapy), marked reduction was observed for all periodontal indicators: VPI (-83%), GBI (-79%), BOP (-85%), elimination of sites PPD ≥7 mm, 27% increase in sites PPD 1-3 mm (from 64% to 91%), and gain of clinical attachment (gain of 11% CAL 1-3 mm and 25% CAL 4-6 mm; and a reduction of 36% CAL ≥7 mm).

Practical Implications: Despite the severity of the initial periodontal condition, the patient with chronic visceral ASMD responded well to the non-surgical periodontal treatment.
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http://dx.doi.org/10.1111/scd.12540DOI Listing
January 2021

The progression of pulmonary arterial hypertension induced by monocrotaline is characterized by lung nitrosative and oxidative stress, and impaired pulmonary artery reactivity.

Eur J Pharmacol 2021 Jan 5;891:173699. Epub 2020 Nov 5.

Laboratory of Cardiovascular Physiology and Reactive Oxygen Species, Physiology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. Electronic address:

The time-course of pulmonary arterial hypertension in the monocrotaline (MCT) model was investigated. Male rats were divided into two groups: MCT (received a 60 mg/kg i.p. injection) and control (received saline). The MCT and control groups were further divided into three cohorts, based on the follow-up interval: 1, 2, and 3 weeks. Right ventricle (RV) catheterization was performed and RV hypertrophy (RVH) was estimated. The lungs were used for biochemical, histological, molecular, and immunohistochemical analysis, while pulmonary artery rings were used for vascular reactivity. MCT promoted lung perivascular edema, inflammatory cells exudation, greater neutrophils and lymphocytes profile, and arteriolar wall thickness, compared to CTR group. Increases in pulmonary artery pressure and in RVH were observed in the MCT 2- and 3-week groups. The first week was marked by the presence of nitrosative stress (50% moderate and 33% accentuated staining by nitrotyrosine). These alterations lead to an adaptation of NO production by NO synthase activity after 2 weeks. Oxidative stress was evident in the third week, probably by an imbalance between endothelin-1 receptors, resulting in extracellular matrix remodeling, endothelial dysfunction, and RVH. Also, it was found a reduced pulmonary arterial vasodilatory response to acetylcholine after 2 (55%) and 3 (45%) weeks in MCT groups. The relevance of this study is precisely to show that nitrosative and oxidative stress predominate in distinct time windows of the disease progression.
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http://dx.doi.org/10.1016/j.ejphar.2020.173699DOI Listing
January 2021

Imbalanced cellular metabolism compromises cartilage homeostasis and joint function in a mouse model of mucolipidosis type III gamma.

Dis Model Mech 2020 11 18;13(11). Epub 2020 Nov 18.

Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany

Mucolipidosis type III (MLIII) gamma is a rare inherited lysosomal storage disorder caused by mutations in encoding the γ-subunit of GlcNAc-1-phosphotransferase, the key enzyme ensuring proper intracellular location of multiple lysosomal enzymes. Patients with MLIII gamma typically present with osteoarthritis and joint stiffness, suggesting cartilage involvement. Using knockout ( ) mice as a model of the human disease, we showed that missorting of a number of lysosomal enzymes is associated with intracellular accumulation of chondroitin sulfate in chondrocytes and their impaired differentiation, as well as with altered microstructure of the cartilage extracellular matrix (ECM). We also demonstrated distinct functional and structural properties of the Achilles tendons isolated from and knock-in ( ) mice, the latter displaying a more severe phenotype resembling mucolipidosis type II (MLII) in humans. Together with comparative analyses of joint mobility in MLII and MLIII patients, these findings provide a basis for better understanding of the molecular reasons leading to joint pathology in these patients. Our data suggest that lack of GlcNAc-1-phosphotransferase activity due to defects in the γ-subunit causes structural changes within the ECM of connective and mechanosensitive tissues, such as cartilage and tendon, and eventually results in functional joint abnormalities typically observed in MLIII gamma patients. This idea was supported by a deficit of the limb motor function in mice challenged on a rotarod under fatigue-associated conditions, suggesting that the impaired motor performance of mice was caused by fatigue and/or pain at the joint.This article has an associated First Person interview with the first author of the paper.
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http://dx.doi.org/10.1242/dmm.046425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687858PMC
November 2020

Improvement in the chemical structure and biological activity of surface titanium after exposure to UVC light.

Odontology 2021 Jan 25;109(1):271-278. Epub 2020 Sep 25.

Department of Surgery and Orthopedics, Dentistry College, Federal University of Rio Grande Do Sul (UFRGS), Ramiro Barcelos, Porto Alegre, 90035-003, Brazil.

Ultraviolet (UV) irradiation has been proposed as a method to reverse the aging process of titanium. However, the intensity, exposure time and wavelength that provide the best results have not yet been determined. The objective of this study was to evaluate the effects of photocatalysis by ultraviolet C light on the time-dependent aging of titanium and to analyze the irradiated titanium for changes in structure and in vitro biological activity, with regard to different exposure times. A titanium photofunctionalization device was developed with characteristics different from those on the market. The sample was composed of titanium disks irradiated for different times of exposure to ultraviolet C light (0, 15, 30 and 60 min). The disks were tested for surface wettability (water contact angle), topography (scanning electron microscopy-SEM) and chemical composition (X-ray photoelectron spectroscopy), and effects on cell adhesion (cell culture and SEM) and cell viability by sulforhodamine B (SRB). Ultraviolet C treatment caused changes in titanium surface characteristics, such as increased wettability and removal of hydrocarbons from the surface after 15 min of exposure in the chamber developed. The biological characteristics of the material also appear to have changed, with improved cell adhesion and viability. Photofunctionalization of titanium proved to be effective for the treatment of aged surfaces, with significant modifications in the surface chemical structure and biological activity of the material.
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http://dx.doi.org/10.1007/s10266-020-00540-wDOI Listing
January 2021

Zinc-based particle with ionic liquid as a hybrid filler for dental adhesive resin.

J Dent 2020 11 17;102:103477. Epub 2020 Sep 17.

Department of Dental Materials, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, 90035-003, Porto Alegre, RS, Brazil. Electronic address:

Objectives: The aim of this study was to evaluate the effect of a zinc-based particle with ionic liquid as filler for an experimental adhesive resin.

Methods: The ionic liquid 1-n-butyl-3-methylimidazolium chloride (BMI.Cl) and zinc chloride (ZnCl) were used to synthesize 1-n-butyl-3-methylimidazolium trichlorozincate (BMI.ZnCl), which was hydrolyzed under basic conditions to produce the simonkolleite (SKT) particles. SKT was analyzed by scanning electron microscopy and transmission electron microscopy. An experimental adhesive resin was formulated and SKT was incorporated at 1, 2.5, or 5 wt.% in the adhesive. One group without SKT was a control group. The antibacterial activity against Streptococcus mutans, cytotoxicity, degree of conversion (DC), ultimate tensile strength (UTS), softening in solvent, and microtensile bond strength (μ-TBS) were investigated.

Results: SKT prepared from the ionic liquid BMI.ZnCl presented a hexagonal shape in the micrometer scale. SKT addition provided antibacterial activity against biofilm formation of S.mutans and planktonic bacteria (p < 0.05). There were no differences in pulp cells' viability (p > 0.05). The DC ranged from 62.18 (±0.83)% for control group to 64.44 (±1.55)% for 2.5 wt.% (p > 0.05). There was no statistically significant difference among groups for UTS (p > 0.05), softening in solvent (p > 0.05), and 24 h or 6 months μ-TBS (p > 0.05).

Conclusions: The physicochemical properties of adhesives were not affected by SKT incorporation, and the filler provided antibacterial activity against S. mutans without changes in the pulp cells' viability. This hybrid zinc-based particle with ionic liquid coating may be a promising filler to improve dental restorations.

Clinical Relevance: A filler based on a zinc-derived material coated with ionic liquid was synthesized and added in dental adhesives, showing antibacterial activity and maintaining the other properties analyzed. SKT may be a promising filler to decrease the biofilm formation around resin-based restorative materials.
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http://dx.doi.org/10.1016/j.jdent.2020.103477DOI Listing
November 2020

Oral, dental, and craniofacial features in chronic acid sphingomyelinase deficiency.

Am J Med Genet A 2020 12 18;182(12):2891-2901. Epub 2020 Sep 18.

Department of Oral Pathology, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.

The aim of this study was to evaluate the oral, dental, and craniofacial features of individuals affected by the chronic forms of acid sphingomyelinase deficiency (ASMD). This study comprised a sample of adult and pediatric patients (n = 8) with chronic ASMD. The individuals underwent oral examinations to evaluate the occurrence of caries, as well as full-mouth periodontal examinations, to assess the occurrence and severity of periodontal diseases. Panoramic and profile radiographs were obtained to analyze dental conditions and craniofacial parameters. Participants also answered questionnaires to identify systemic impairment, parafunctional habits, and bruxism. Dental anomalies of size, shape, and number were found, with agenesis and microdontia being the predominant findings. The average of caries experience was 11.75 (±8.1). Only one patient had periodontal health and all adult individuals had periodontitis at different stages and degrees. Bruxism was found in 87.5% of the sample. The convex profile and maxillary and mandibular retrusion were the most relevant findings in the cephalometric analysis. It is concluded that individuals with chronic ASMD, in addition to several systemic manifestations, present significant modifications in their oral health, from a greater occurrence of dental anomalies, caries, periodontal disease, in addition to skeletal changes.
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http://dx.doi.org/10.1002/ajmg.a.61871DOI Listing
December 2020

Chemical, Mechanical and Biological Properties of an Adhesive Resin with Alkyl Trimethyl Ammonium Bromide-loaded Halloysite Nanotubes.

J Adhes Dent 2020 ;22(4):399-407

Purpose: The aim of this study was to evaluate the chemomechanical properties, antibacterial activity, and cytotoxicity of an experimental adhesive resin containing halloysite nanotubes (HNT), doped with alkyl trimethyl ammonium bromide (ATAB).

Materials And Methods: A filler of HNT doped with ATAB was obtained (ATAB:HNT) and incorporated (5 wt%) into a resin blend made of bisphenol A glycerolate dimethacrylate, 2-hydroxyethyl methacrylate and a photoinitiator/co-initiator system (GATAB:HNT). The same resin blend without ATAB:HNT was used as control (Ctrl). The ATAB:HNT filler was assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The two tested adhesives were evaluated for degree of conversion (DC) in vitro and in situ, softening in alcohol, dentin microtensile bond strength (µTBS), antibacterial activity, and cytotoxicity (n = 5).

Results: SEM showed that the nanotubes had a characteristic tubular-needle morphology, while the TEM analysis confirmed the presence of ATAB inside the lumens of HNT. The incorporation of ATAB:HNT induced no reduction (p > 0.05) of the DC either in situ or in vitro. No difference was encountered after the softening challenge test (p > 0.05) and no difference was found in µTBS between the two adhesives, both at 24 h (p > 0.05) and after 6 months of storage in distilled water (p > 0.05). However, ATAB:HNT reduced Streptococcus mutans viability (p < 0.05) without a cytotoxic effect on pulp cells (p > 0.05).

Conclusions: GATAB:HNT adhesive demonstrated appropriate polymerization without significant differences in softening after solvent immersion, while concomitantly maintaining reliable bond strength after 6 months of water aging. Moreover, the ATAB:HNT filler can provide antibacterial activity to the adhesive resin without affecting pulp cell viability.
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http://dx.doi.org/10.3290/j.jad.a44871DOI Listing
July 2020

Effect of Obesity and/or Ligature-induced Periodontitis on Aortic Wall Thickness in Wistar Rats.

Acta Odontol Latinoam 2020 Apr;33(1):50-55

Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Departmento de Periodontia, Rio Grande do Sul, Brasil.

The purpose of this study was to evaluate aortic wall thickness after periodontal disease and/or obesity induction in a Wistar rat model.Sixty male Wistar rats were randomly divided into four groups: control (CT), periodontal disease (PD), obesity (OB), and obesity plus periodontal disease (OB+PD). Groups OB and OB+PD received cafeteria diet for 17 weeks. After they had acquired obesity (week 12), periodontal disease was induced by placing a silk ligature on the maxillary right second molar of groups PD and OB+PD. During the experimental period, body weight and Lee index were assessed. Mean alveolar bone loss (ABL) was evaluated, and aortas were prepared for histometric analysis of the aortic wall by ImageJ software. Body weight and Lee index increased in rats exposed to cafeteria diet. Mean ABL was higher in Groups PD and OB+PD than in control and OB (p<0.05). ABL was 18% higher in Group OB+PD than in Group PD, with statistically significant difference (p<0.001). Aortas were thicker in Groups OB and OB+PD than in control and PD groups, respectively (2.31mm ± 0.28 and 2.33 ± 0.29 vs. 2.18 ± 0.26 and 2.14 ± 0.27). Group OB differed significantly from the control group (p=0.036), and OB+PD and OB differed significantly from PD (p=0.004 and p= 0.001, respectively). Obesity alters aortic wall thickness in Wistar rats. However, the presence of periodontal disease did not affect the aortic wall thickness under the conditions of the present study.
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April 2020

Argyrophilic nucleolar organizer regions in oral mucosa cells of crack and cocaine users: a cross-sectional study.

Environ Sci Pollut Res Int 2020 Oct 2;27(30):37920-37926. Epub 2020 Jul 2.

Laboratory of Oral and Maxillofacial Pathology, School of Dentistry, Federal University of Bahia, Av. Araújo Pinho, 62- Canela, Salvador, Bahia, 40110-150, Brazil.

The objective of this study was to analyze and compare the presence of argyrophilic nucleolar organizer regions (AgNORs) in exfoliated cells obtained from the buccal mucosa among crack and cocaine users and non-users by the AgNOR staining technique. Seventy-three males ≥ 18 years were categorized into two groups: 38 crack and/or cocaine users and 35 non-user volunteers. They were interviewed and responded a questionnaire regarding general health and drug addiction. Exfoliative cytology specimens were collected from the clinically intact buccal mucosa, and cytological preparations were fixed and stained by AgNOR technique. The mean number of AgNORs (p = 0.02) and the percentage of epithelial cells with more than 3 (p = 0.01) and 4 (p = 0.04) AgNORs/nucleus were significantly higher in the non-user group. In conclusion, the frequency and diversity of substances present in the drugs-cocaine, crack, and alcohol-consumed by the volunteers of this study may have influenced the number of AgNORs and the response to damage and consequent effect on protein synthesis.
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http://dx.doi.org/10.1007/s11356-020-09892-wDOI Listing
October 2020

Pericoronal follicles revealing unsuspected odontogenic cysts and inflammatory lesions: A retrospective microscopy study.

Indian J Dent Res 2020 Jan-Feb;31(1):80-84

Universidade Federal do Rio Grande Do Sul, Porto Alegre, Brazil.

Aim: This study aimed to analyze the prevalence of diseases related to pericoronal follicles, and assess the rate of concordance between clinical and histopathological diagnoses.

Methods: Histologically, we analyzed 1,298 tissue samples surrounding the crowns of teeth that were diagnosed clinically as pericoronal follicles. In addition, we determined associations among histopathological diagnosis, patients' age and sex, tissue site, presence of nests of odontogenic epithelium, presence of reduced enamel epithelium, and presence of diffuse inflammation.

Results: Odontogenic pathologies were present in 35% of the samples, and rate of concordance between clinical and histopathological diagnoses was 0.54. Probability of developing odontogenic pathologies was high in the mandibular molars (odds ratio: 2.13) and in the tissues with odontogenic epithelial remnants (odds ratio: 1.2), reduced enamel epithelium (odds ratio: 1.3), and diffuse inflammation. (odds ratio: 10.5).

Conclusions: The findings of this study highlight the clinical relevance of histopathological examination of the pericoronal tissue in unerupted and partially erupted teeth for early diagnosis of pathologies because this study demonstrated the odontogenic cysts and inflammatory lesions in tissues clinically diagnosed as pericoronal follicles.
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http://dx.doi.org/10.4103/ijdr.IJDR_459_18DOI Listing
April 2020

Myristyltrimethylammonium Bromide (MYTAB) as a Cationic Surface Agent to Inhibit Grown over Dental Resins: An In Vitro Study.

J Funct Biomater 2020 Feb 15;11(1). Epub 2020 Feb 15.

Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre-RS, Brazil.

This in vitro study evaluated the effect of myristyltrimethylammonium bromide (MYTAB) on the physical, chemical, and biological properties of an experimental dental resin. The resin was formulated with dental dimetacrylate monomers and a photoinitiator/co-initiator system. MYTAB was added at 0.5 (G), 1 (G), and 2 (G) wt %, and one group remained without MYTAB and was used as the control (G). The resins were analyzed for the polymerization kinetics, degree of conversion, ultimate tensile strength (UTS), antibacterial activity against , and cytotoxicity against human keratinocytes. Changes in the polymerization kinetics profiling were observed, and the degree of conversion ranged from 57.36% (±2.50%) for G to 61.88% (±1.91%) for G, without a statistically significant difference among groups ( > 0.05). The UTS values ranged from 32.85 (±6.08) MPa for G to 35.12 (±5.74) MPa for G ( > 0.05). MYTAB groups showed antibacterial activity against biofilm formation from 0.5 wt % ( < 0.05) and against planktonic bacteria from 1 wt % ( < 0.05). The higher the MYTAB concentration, the higher the cytotoxic effect, without differences between G e G ( > 0.05). In conclusion, the addition of 0.5 wt % of MYTAB did not alter the physical and chemical properties of the dental resin and provided antibacterial activity without cytotoxic effect.
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http://dx.doi.org/10.3390/jfb11010009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7151596PMC
February 2020

Progressive eye pathology in mucopolysaccharidosis type I mice and effects of enzyme replacement therapy.

Clin Exp Ophthalmol 2020 04 30;48(3):334-342. Epub 2020 Jan 30.

Gene Therapy Center, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil.

Background: Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder caused by α-L-iduronidase deficiency, resulting in accumulation of glycosaminoglycans (GAG). Ophthalmological manifestations are common in MPS I patients and often lead to visual impairment. Accumulation of GAG in corneal or retinal tissues reduces vision causing corneal opacity and neurosensory complications. One available treatment for MPS I patients is enzyme replacement therapy (ERT), but the results of such treatment on eye disease are still debatable. Therefore, we aimed to determine the progression of ocular manifestations as well as the effectiveness of intravenous ERT in MPS I.

Methods: Corneal and retinal analyses were perform in eyes from 2- to 8-month normal and MPS I mice. Some MPS I mice received ERT (1.2 mg/kg of laronidase) every 2 weeks from 6 to 8 months and histological findings were compared with controls. Additionally, cornea from two MPS I patients under ERT were evaluated.

Results: Mouse corneal tissues had GAG accumulation early in life. In the retina, we found a progressive loss of photoreceptor cells, starting at 6 months. ERT did not improve or stabilize the histological abnormalities. MPS I patients, despite being on ERT for over a decade, presented GAG accumulation in the cornea, corneal thickening, visual loss and needed corneal transplantation.

Conclusion: We provide data on the time course of ocular alteration in MPS I mice. Our results also suggest that ERT is not effective in treating the progressive ocular manifestations in MPS I mice and fails to prevent corneal abnormalities in patients.
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http://dx.doi.org/10.1111/ceo.13713DOI Listing
April 2020

Niobium containing bioactive glasses as remineralizing filler for adhesive resins.

Dent Mater 2020 02 30;36(2):221-228. Epub 2019 Nov 30.

Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul, Brazil. Electronic address:

Objective: The aim of this study was to incorporate sol-gel-derived bioactive glass as filler into experimental adhesive resins and evaluate the influence of glass composition on the physicochemical and biological properties of the developed adhesives.

Materials And Methods: Sol-gel particles were produced with or without the addition of niobium (BAGNb or BAG, respectively). The produced particles were incorporated (2wt%) into experimental adhesive resins formulated with 66wt% bisphenol A-glycidyl methacrylate and 33wt% hydroxyethyl methacrylate. Ethyl dimethyl-4-aminobenzoate and camphorquinone were used as photoinitiator system. Two experimental groups were produced: A and A The adhesive without particles was used as control (A). The materials were tested for their degree of conversion, softening in solvent, and cytotoxicity. The mineral deposition was analyzed by Raman spectroscopy. Flexural strength and immediate and 1-year microtensile bond strength were evaluated.

Results: No statistical difference was found in degree of conversion. A showed reduced softening and higher mineral deposition than A and A after 28 days. A and A resulted in higher cell viability and lower flexural strength when compared to A. After 1-year, A and A presented statistically significant lower μTBS values.

Significance: Sol-gel-derived bioactive glasses promoted increased mineral deposition and cell viability for experimental adhesives with increased phosphate content and longitudinal μTBS values for the A group. These results suggest the potential of the studied particles to be applied as bioactive fillers for dental adhesives. Reductions in longitudinal μTBS and flexural strength, however, were observed for both glasses compositions and must be considered.
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http://dx.doi.org/10.1016/j.dental.2019.11.014DOI Listing
February 2020

Synthesis of sol-gel derived calcium silicate particles and development of a bioactive endodontic cement.

Dent Mater 2020 01 26;36(1):135-144. Epub 2019 Nov 26.

Dental Materials Laboratory, School of Dentistry, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil. Electronic address:

Objective: The aim of this study is to produce sol-gel derived calcium silicate particles (CS) and evaluate the influence of different concentration of calcium tungstate in the physical, chemical, mechanical and biological properties of developed cements.

Methods: Sol-gel route were used to synthesize calcium silicate particles that were characterized with x-ray difraction, Fourier transformed infrared spectroscopy, scanning electron microscopy, laser diffraction and nitrogen absorption. Cements were formulated with the addition of different concentrations of calcium tungstate (CaWO), resulting in four experimental groups according to the CS:CaWO ratio: CS (100:0), CS (90:10), CS (80:20), CS (70:30). The setting time, radiopacity, compressive strength, pH, calcium release, cell proliferation and cell differentiation were used to characterize the cements.

Results: CS particles were succesfully sinthesized. The addition of CaWO increased the radiopacity and did not influenced the setting time and the mechanical properties of cements. The pH of distilled water was increased for all groups and the CS and CS groups presented incresed calcium release. Reduced cell viability was found for CS while CS and CS presented higher ALP activity and % of mineralized nodules after 21 days.

Significance: Sol-gel derived CS particles were sucssfully developed with potential to applied for the production of bioactive ceramic cements. The addition of 10% of CaWO resulted in cements with adequate properties and bioactivity being an alternative for regenerative endodontic treatments.
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http://dx.doi.org/10.1016/j.dental.2019.11.004DOI Listing
January 2020

Correction to: Treatment modalities for burning mouth syndrome: a systematic review.

Clin Oral Investig 2019 09;23(9):3657

Oral Pathology Department, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.

The original version of this article contained two mistakes. First, in the subchapter "Alpha-lipoic acid (ALA)" page 1895, reference 4 is cited three times, however reference 42 is the correct one.
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http://dx.doi.org/10.1007/s00784-019-03038-0DOI Listing
September 2019

Therapeutic ultrasound attenuates DSS-induced colitis through the cholinergic anti-inflammatory pathway.

EBioMedicine 2019 Jul 26;45:495-510. Epub 2019 Jun 26.

Frank Laboratory, Radiology and Imaging Sciences, Clinical Centre, NIH, Bethesda, MD, United States; National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD, United States.

Background: Ulcerative Colitis (UC) is an Inflammatory Bowel Disease (IBD) characterized by uncontrolled immune response, diarrhoea, weight loss and bloody stools, where sustained remission is not currently achievable. Dextran Sulphate Sodium (DSS)-induced colitis is an animal model that closely mimics human UC. Ultrasound (US) has been shown to prevent experimental acute kidney injury through vagus nerve (VN) stimulation and activation of the cholinergic anti-inflammatory pathway (CAIP). Since IBD patients may present dysfunctional VN activity, our aim was to determine the effects of therapeutic ultrasound (TUS) in DSS-induced colitis.

Methods: Acute colitis was induced by 2% DSS in drinking water for 7 days and TUS was administered to the abdominal area for 7 min/day from days 4-10. Clinical symptoms were analysed, and biological samples were collected for proteomics, macroscopic and microscopic analysis, flow cytometry and immunohistochemistry.

Findings: TUS attenuated colitis by reducing clinical scores, colon shortening and histological damage, inducing proteomic tolerogenic response in the gut during the injury phase and early recovery of experimental colitis. TUS did not improve clinical and pathological outcomes in splenectomised mice, while α7nAChR (α7 nicotinic acetylcholine receptor - indicator of CAIP involvement) knockout animals presented with disease worsening. Increased levels of colonic F4/80α7nAChR macrophages in wild type mice suggest CAIP activation.

Interpretation: These results indicate TUS improved DSS-induced colitis through stimulation of the splenic nerve along with possible contribution by VN with CAIP activation. FUND: Intramural Research Programs of the Clinical Centre, the National Institute of Biomedical Imaging and Bioengineering at the NIH and CAPES/Brazil.
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http://dx.doi.org/10.1016/j.ebiom.2019.06.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6642284PMC
July 2019

Quaternary ammonium compound as antimicrobial agent in resin-based sealants.

Clin Oral Investig 2020 Feb 1;24(2):777-784. Epub 2019 Jun 1.

Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil.

Objectives: The aim of this study was to evaluate the influence of [2-(methacryloyloxy)ethyl] trimethylammonium chloride (METAC) in the physico-chemical properties, antibacterial activity and cytotoxicity of an experimental resin-based sealant.

Materials And Methods: An experimental resin-based sealant was formulated with dimethacrylates and a photoinitiator system. METAC was added at 2.5 wt.% (G) and 5 wt.% (G) into the experimental resin-based sealant, and one group remained without METAC as control (G). The resin-based sealants were analysed for polymerization behaviour and degree of conversion (DC), Knoop hardness (KHN) and softening in solvent (ΔKHN), ultimate tensile strength (UTS), contact angle, surface free energy (SFE), immediate and long-term micro-shear bond strength (μ-SBS) and antibacterial activity and cytotoxicity against human keratinocytes.

Results: The experimental resin-based sealants presented different polymerization behaviours without significant differences in the DC (p > 0.05). There was no significant difference for initial KHN (p > 0.05). The ΔKHN ranged from 51.62 (±3.70)% to 62.40 (±4.14)%, with higher values for G (p < 0.05). G and G had decreased μ-SBS between immediate and long-term tests (p < 0.05) without significant differences among groups in the immediate and long-term analyses (p > 0.05). There were no significant differences for UTS, contact angle and SFE among groups (p > 0.05). G and G presented immediate and long-term antibacterial activity (p < 0.05) without cytotoxicity compared to G (p > 0.05).

Conclusion: The addition of METAC provided antibacterial activity to the experimental resin-based sealant.

Clinical Relevance: METAC is an effective quaternary ammonium compound as an antibacterial agent for resin-based sealants without cytotoxic effects against human keratinocytes.
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http://dx.doi.org/10.1007/s00784-019-02971-4DOI Listing
February 2020

Somatic mutations and promotor methylation of the ryanodine receptor 2 is a common event in the pathogenesis of head and neck cancer.

Int J Cancer 2019 12 19;145(12):3299-3310. Epub 2019 Jun 19.

Division of Molecular and Translational Radiation Oncology, Heidelberg Ion Therapy Center (HIT), Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg University Hospital, and Translational Radiation Oncology, German Cancer Consortium (DKTK), National Center for Tumor Diseases (NCT), German Cancer Research Center (DKFZ), Heidelberg, Germany.

Genomic sequencing projects unraveled the mutational landscape of head and neck squamous cell carcinoma (HNSCC) and provided a comprehensive catalog of somatic mutations. However, the limited number of significant cancer-related genes obtained so far only partially explains the biological complexity of HNSCC and hampers the development of novel diagnostic biomarkers and therapeutic targets. We pursued a multiscale omics approach based on whole-exome sequencing, global DNA methylation and gene expression profiling data derived from tumor samples of the HIPO-HNC cohort (n = 87), and confirmed new findings with datasets from The Cancer Genome Atlas (TCGA). Promoter methylation was confirmed by MassARRAY analysis and protein expression was assessed by immunohistochemistry and immunofluorescence staining. We discovered a set of cancer-related genes with frequent somatic mutations and high frequency of promoter methylation. This included the ryanodine receptor 2 (RYR2), which showed variable promoter methylation and expression in both tumor samples and cell lines. Immunohistochemical staining of tissue sections unraveled a gradual loss of RYR2 expression from normal mucosa via dysplastic lesion to invasive cancer and indicated that reduced RYR2 expression in adjacent tissue and precancerous lesions might serve as risk factor for unfavorable prognosis and upcoming malignant conversion. In summary, our data indicate that impaired RYR2 function by either somatic mutation or epigenetic silencing is a common event in HNSCC pathogenesis. Detection of RYR2 expression and/or promoter methylation might enable risk assessment for malignant conversion of dysplastic lesions.
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http://dx.doi.org/10.1002/ijc.32481DOI Listing
December 2019

Ionic liquid as antibacterial agent for an experimental orthodontic adhesive.

Dent Mater 2019 08 23;35(8):1155-1165. Epub 2019 May 23.

Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, 2492, Rio Branco, Porto Alegre, RS, 90035-003, Brazil. Electronic address:

Objective: The aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf).

Methods: The experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf was synthesized and characterized. BMIM.NTf was added at 5 (G), 10 (G) and 15 (G) wt.%. One group contained no BMIM.NTf to function as control (G). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity.

Results: BMI.NTf showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G and G showed higher DC (p < 0.05). G and G had no differences for softening in solvent (p > 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G. All groups with BMIM.NTf showed antibacterial activity compared to G (p < 0.05) without cytotoxicity (p > 0.05).

Significance: To reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.
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http://dx.doi.org/10.1016/j.dental.2019.05.010DOI Listing
August 2019

Treatment of actinic cheilitis: a systematic review.

Clin Oral Investig 2019 May 23;23(5):2041-2053. Epub 2019 Apr 23.

Oral Pathology Department, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2492, Room 503, Porto Alegre, RS, 90035-003, Brazil.

Objectives: Actinic cheilitis is a potentially malignant disorder caused by excessive sun exposure. It affects the lower lip of individuals, mostly those with light skin color. Different treatments have been proposed for AC; however, no consensus has been reached on the best option available.

Materials And Methods: The present study describes the results of a computer-based systematic search conducted on electronic databases to identify the best therapies.

Results: A total of 29 journal articles were selected, and the results were divided according to the type of treatment employed: laser therapy, chemotherapy agents, surgical treatment, and application of anti-inflammatory agents. Clinically, photodynamic therapy showed positive results, with improvement in up to 100% of the patients; however, histopathological improvement varied greatly, from 16 to 100%. Among the chemotherapeutic agents assessed, imiquimod showed the best results: clinical improvement in 80 to 100% of the patients, and histopathological improvement in 73 to 100%. Regarding studies describing surgical approaches, the main focus was the search for the best technique, rather than the cure of AC. Finally, studies employing anti-inflammatory agents are sparse and have small samples, thus providing limited results.

Conclusion: The scientific evidence available on the treatment of AC is scarce and heterogeneous, photodynamic therapy, and imiquimod application are promising.

Clinical Relevance: The study of the treatments for AC in the form of a systematic review allows us to evaluate the results against the different treatments. Being a potentially malignant lesion, it is important to seek evidence about the best results found.
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http://dx.doi.org/10.1007/s00784-019-02895-zDOI Listing
May 2019

Cytopathological tests for early detection of oral carcinogenesis.

Eur J Cancer Prev 2020 01;29(1):73-79

Department of Oral Pathology, Federal University of Rio Grande do Sul.

The carcinogenesis in the oral cavity occurs as a multistep process and is often preceded by potentially malignant lesions. The main risk factors for the development of oral cancer are smoking and alcohol intake. The current challenge is to identify patients at greatest risk for the development of oral cancer using noninvasive and effective methods. The aim of this study is to evaluate the microsatellite mutations in the 9p21 locus, the cell proliferative activity, the pattern of epithelial desquamation, and the nucleus/cytoplasm ratio of exfoliated epithelial cells. Cytopathological samples were collected from 131 individuals divided into four groups: control (n = 26), alcohol-smoking (n = 32), leukoplakia (n = 38), and the oral squamous cell carcinoma group (OSCC, n = 35). From the cytological scraping, a slide was silver impregnated for Ag-stained nucleolar organizer region analysis and another slide was stained using the Papanicolaou technique. The remaining cells were used for DNA extraction, followed by PCR amplification and capillary electrophoresis. The cell proliferation velocity rate was higher in the leukoplakia and OSCC groups compared with the control group (P < 0.05). The leukoplakia group showed increased anucleated scales, whereas the nucleated superficial predominated in the control group and the parabasal cells in the OSCC group (P < 0.05). An increased nucleus/cytoplasm ratio was detected only in the OSCC group (P < 0.05). The 9p21 locus mutation frequency was higher in the alcohol-smoking and leukoplakia groups. 9p21 analysis and Ag-stained nucleolar organizer region methods are promising for the screening and monitoring of individuals at higher risk for the development of oral cancer.
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http://dx.doi.org/10.1097/CEJ.0000000000000513DOI Listing
January 2020
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