Márcia Martins Marques

Stem Cell Proliferation Under Low Intensity Laser Irradiation: A Preliminary Study

Phototherapy with low intensity laser irradiation has shown to be effective in promoting the proliferation of different cells. The aim of this in vitro study was to evaluate the potential effect of laser phototherapy (660 nm) on human dental pulp stem cell (hDPSC) proliferation.

LASER PHOTOTHERAPY AS TOPICAL PROPHYLAXIS AGAINST HEAD AND NECK CANCER RADIOTHERAPY-INDUCED ORAL MUCOSITIS: COMPARISON BETWEEN LOW AND HIGH/LOW POWER LASERS

Oral mucositis is a dose‐limiting and painful side effect of radiotherapy (RT) and/or chemotherapy in cancer patients. The purpose of the present study was to analyze the effect of different protocols of laser phototherapy (LPT) on the grade of mucositis and degree of pain in patients under RT.

Association of laser phototherapy with PRP improves healing of bisphosphonate-related osteonecrosis of the jaws in cancer patients: A preliminary study

The aim of this study was to compare retrospectively the effect of three different treatments on the healing outcome of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in cancer patients. Twenty-two cancer patients were treated for BRONJ with one of the following protocols: clinical (pharmacological therapy), surgical (pharmacological plus surgical therapy), or PRP plus LPT (pharmacological plus surgical plus platelet rich plasma (PRP) plus laser phototherapy (LPT). The laser treatment was applied with a continuous diode laser (InGaAlP, 660 nm) using punctual and contact mode, 40 mW, spot size 0.042 cm(2), 6 J/cm(2) (6 s) and total energy of 0.24 J per point. The irradiations were performed on the exposed bone and surrounding soft tissue. The analysis of demographic data and risk factors was performed by gathering the following information: age, gender, primary tumor, bisphosphonate (BP) used, duration of BP intake, history of chemotherapy, use of steroids, and medical history of diabetes. The association between the current state of BRONJ (with or without bone exposure) and other qualitative variables was determined using the chi-square or Fishers exact test. In all tests, the significance level adopted was 5%. Most BRONJ lesions occurred in the mandible (77%) after tooth extraction (55%) and in women (72%). A significantly higher percentage of patients reached the current state of BRONJ without bone exposure (86%) in the PPR plus LPT group than in the pharmacological (0%) and surgical (40%) groups after 1-month follow-up assessment. These results suggest that the association of pharmacological therapy and surgical therapy with PRP plus LPT significantly improves BRONJ healing in oncologic patients. Although prospective studies with larger sample sizes are still needed, this preliminary study may be used to inform a better-designed future study.

Comparative analysis between Chamomilla recutita and corticosteroids on wound healing. An in vitro and in vivo study

The comparison of chamomile and corticosteroids for treating ulcers was done in vitro and in vivo. The experimental groups were: control; chamomile recutita; triamcinolone acetonide and clobetasol propionate. For the in vitro study the cell viability of fibroblasts cultured for 24 h in media conditioned by the substances was obtained by the MTT reduction analysis. For the in vivo study, 125 male rats were submitted to experimental ulcers treated or not (control) by the substances tested. At 1, 3, 5, 7 and 14 days later 5 animals of each group were sacrificed. The lesions were analyzed by means of clinical observation and histological wound‐healing grading. Data were compared by ANOVA (p ≤ 0.05). All experimental groups presented positive cell viability in 24 h. The cultures treated with chamomile presented the smallest cell viability. All animals of the chamomile group exhibited complete wound healing 9 days before the other groups. Complete repaired lesions were observed after 5 days of treatment only in the chamomile group. Animals treated with chamomile presented significantly faster wound healing in comparison to those treated with corticosteroids. Based on the conditions of this study, we concluded that chamomile in comparison to corticosteroids promotes faster wound healing process. Copyright

Cytotoxic effects of cyanoacrylates used as retrograde filling materials: an in vitro analysis.

Cyanoacrylate has been used in medicine and dentistry for many years. It has been used as a postextraction dressing and retrograde filling material in endodontic surgery. The aim of this study was to evaluate the cytotoxic effects of Histoacryl and other two homologue ethyl cyanoacrylates, Super Bonder and Ultrabond, on cultured fibroblasts, using the Trypan blue dye exclusion assay. The cyanoacrylates were applied to round glass coverslips, which were placed in contact with NIH 3T3 cells. After 0, 6, 12 and 24 h (short-term assay; viability) and 1, 3, 5 and 7 days (long-term assay; survival), the cells were examined under phase light microscopy and counted. The data were compared by the Kruskal-Wallis test. In the short-term experiments, only the cultures of the Ultrabond group (GIV) presented significant smaller percentages of cell viability than the cultures of the other groups (GI: control; GII: Super Bonder; GIII: Histoacryl). Although the cultures of the Super Bonder group (GII) presented smaller percentages of cell viability than cultures of the other groups (GI, GIII, GIV) at the long-term assay, this group was the only experimental group presenting a continuous and progressive cell growth. Our results have shown an in vitro biocompatibility of Histoacryl and ethyl cyanoacrylate homologues. These cyanoacrylates could therefore be of importance for endodontic purposes.

In vitro analysis of inhibitory effects of the antibacterial monomer MDPB-containing restorations on the progression of secondary root caries

OBJECTIVE This study aimed to analyze in vitro inhibitory effects of restorative materials containing the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the formation of artificial secondary root caries lesions. METHODS Class V cavities (2mmx2mm) were prepared in 75 human root fragments. Specimens were randomly divided into five groups (n=15 fragments per group) and restored as follows: (I) MDPB-free adhesive system+MDPB-free composite (negative control); (II) resin modified glass ionomer (RM-GIC; positive control); (III) MDPB-free adhesive system+MDPB-containing composite (2.83% MDPB); (IV) MDPB-containing adhesive system+MDPB-free composite; (V) MDPB-containing adhesive system+MDPB-containing composite. Artificial secondary root caries lesions were produced by a biological artificial caries challenge. The restored specimens were immersed into a culture medium containing Streptococcus mutans and sucrose for 15 days. Histological slices (80+/-20 microm) of the specimens were used for measuring the mean depths of the artificial lesions produced in both margins of the restorations using polarized light microscopy. Results were expressed in percentage related to the mean depth of the negative control, considered 100%. Data were compared by ANOVA followed by the Tukeys test (p< or =0.05). RESULTS The depths of lesions adjacent to cavities filled with RM-GIC (GII; 85.17+/-15.2%) were significantly (p<0.01) shallower than those adjacent to restorations with MDPB-free composite (GI; 100.00+/-10.04%), despite the presence of MDPB in the adhesive system (GIV; 101.95+/-21.32%). The depths of lesions adjacent to cavities restored with MDPB-containing composite (GIII; 82.68+/-12.81% and GV; 85.65+/-15.42%), despite the adhesive system used, were similar to those of RM-GIC (GII). Mean lesions depths in these groups decreased from 13% (GV) to 17% (GIII) in relation to the negative control (GI). CONCLUSIONS MDPB-containing composite inhibits the progression of artificial secondary root caries lesions regardless of adhesive systems.

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat.

Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1beta (IL-1beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1beta concentration in brain of the control group was significantly reduced in 24 h (p<0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p<0.01 and p<0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury.

Effects of TGF-β1, PDGF-BB, and IGF-1 on the rate of proliferation and adhesion of a periodontal ligament cell lineage in vitro

BACKGROUND Considering the role of growth factors in periodontal regeneration, the aim of this study was to evaluate the influence of platelet-derived growth factor (PDGF)-BB, insulin-like growth factor (IGF)-1, and transforming growth factor-beta 1(TGF-β1), alone or in combination, on the rate of proliferation and adhesion of periodontal ligament (PDL) cells in vitro. METHODS After establishment and characterization of a primary culture of PDL cells, 72 culture dishes were plated with 103 cells distributed among four test groups and a control group. Test groups had PDGF-BB, TGF-β1, IGF-1, or a combination of all three added to the culture medium, whereas the control group received no growth factor. The samples were counted in triplicate 1, 3, 5, and 7 days after seeding. For the adhesion assay, 14 patients provided 30 root fragments distributed among 10 groups: scaling and root planing (SRP), SRP + growth factors, SRP + citric acid plus tetracycline (CA+T), and SRP + (CA+T) + growth factors. The data were evaluated statistically by analysis of variance complemented by Tukey, Dunnett, and Student-Newman-Keuels methods. RESULTS Maximum rates of proliferation were observed at day 3 for all groups. TGF-β1 induced a 344.17% ± 58.80% increased proliferation rate over control (P <0.05), followed by the combination (277.5% ± 29.38%), PDGF-BB (238.79% ± 5.79%), and IGF-1 (233.16% ± 19.19%). Groups treated by (CA+T) showed increased numbers of cells attached to root fragments, especially SRP + (CA+T) + combination (13.25 ± 1.79), with significant differences (P <0.05) from groups treated only by SRP. CONCLUSION This combination of growth factors stimulated a mitogenic response and favored the adhesion of PDL cells in vitro, suggesting its possible role in periodontal regeneration.

NEOLIGNANS FROM LICARIA AUREA

Abstract The fruit calyces of Licaria aurea were found to contain the diaryltetrahydrofuran type neolignans grandisin, de- O -methylgrandisin and dide- O -methylgrandisin, as well the β-aryloxy-arylpropane type neolignans virolongin A and virolongin B.

Autoimmune regulator (Aire) controls the expression of microRNAs in medullary thymic epithelial cells

The autoimmune regulator (Aire) is a transcription factor that controls the ectopic expression of a large set of peripheral tissue antigen (PTA) genes in medullary thymic epithelial cells (mTECs). Recent evidence has demonstrated that Aire releases stalled RNA polymerase II (RNA Pol II) from blockage at the promoter region of its target genes. Given that, in addition to messenger RNAs (mRNA), RNA Pol II also transcribes microRNAs (miRNAs), we raised the hypothesis that Aire might play a role as an upstream controller of miRNA transcription. To test this, we initially analyzed the expression profiles of 662 miRNAs in control and Aire-silenced (siRNA) murine mTEC 3.10 cells using microarrays. The bioinformatics programs SAM and Cluster-TreeView were then used to identify the differentially expressed miRNAs and their profiles, respectively. Thirty Aire-dependent miRNAs were identified in the Aire-silenced mTECs, of which 18 were up- and 12 were down-regulated. The down-regulated miR-376 family was the focus of this study because its members (miR-376a, miR-376b and miR-376c) are located in the genome within the Gm2922 open-reading frame (ORF) gene segment on the chromosome 12F1. The T-boxes (TTATTA) and G-boxes (GATTGG), which represent putative RNA Pol II promoter motifs, were located in a portion spanning 10 kb upstream of the ATG codon of Gm2922. Moreover, we found that Gm2922 encodes an mRNA, which was also down-regulated in Aire-silenced mTECs. These results represent the first evidence that Aire can play a role as a controller of transcription of miRNAs located within genomic regions encompassing ORF and/or mRNA genes.