Toxigenic characterization, spoilage potential, and antimicrobial susceptibility of coagulase-positive Staphylococcus species isolated from Minas Frescal cheese.

This study aimed to identify coagulase-positive staphylococci (CPS) species from 21 samples of clandestine Minas Frescal cheese, investigate the potential for deterioration in psychrotrophic and mesophilic conditions, verify the toxigenic potential of Staphylococcus aureus, and determine the antimicrobial susceptibility profile of toxigenic S. aureus. Species determination was performed based on the detection of ß-hemolysis in 5% ovine blood agar; fermentation of mannitol, maltose, and trehalose sugars; and production of acetoin. After species determination, DNA extraction and analysis was performed for S. aureus colonies for genes encoding staphylococcal toxins (eta, etb, tst, sea, seb, sec, sed, and see) using 2 multiplex PCR assays. Isolates identified as toxigenic S. aureus were tested for antimicrobial susceptibility to tetracycline, erythromycin, clindamycin, gentamicin, ciprofloxacin, sulfazotrim, trimethoprim, streptomycin, cefoxitin, vancomycin and enrofloxacin. Elevated CPS counts were observed with an average of >6 log cfu/g. Of the 355 isolates, 177 (49.86%) were identified as S. aureus. Staphylococcus hyicus, Staphylococcus intermedius, Staphylococcus delphini, and Staphylococcus coagulans were identified in 3 (0.84%), 2 (0.56%), 2 (0.56%), and 1 (0.28%) isolates, respectively. Of the total number of S. aureus, 25 (52.08%) were positive for the gene that encodes for toxic shock toxin (TSST-1). Another 16 (33.33%) were positive for the sea gene, and 4 isolates (8.33%) were positive for see and one isolate each was positive for seb (2.08%), sec (2.08%), and etb (2.08%) genes. All isolates demonstrated lipolytic activity under mesophilic and psychrotrophic conditions. S. intermedius and S. hyicus had the most prominent proteolytic potential. Multidrug resistance was observed in most of the potentially toxigenic isolates, with clindamycin having the lowest efficiency (40%), whereas the aminoglycosides (gentamicin and streptomycin) had the highest effectiveness demonstrating inhibition in all evaluated isolates. Methicillin-resistant S. aureus (MRSA) was detected. Minas Frescal cheeses, marketed in the north of Tocantins in the Brazilian Amazon region, do not comply with legal quality standards and pose a public health risk due to the enterotoxigenic potential of multiresistant isolates, in addition to low shelf life of the samples given the high spoilage potential of this microbiota.

Evaluation of bone repair with platelet-rich fibrin following the extraction of impacted third molars - randomized clinical trial.

BACKGROUND: The aim of the present study was to evaluate postoperative effects of platelet-rich fibrin (PRF) in wound and bone healing, pain, swelling and periodontal complications outcomes after impacted third molars extraction. MATERIAL AND METHODS: A prospective, randomized, split-mouth, double-blind clinical trial was conducted. PRF was placed within sockets following tooth removal and before suturing mucoperiosteal flap while no treatment was performed on control group's sockets. Patients were evaluated considering bone volume which was obtained in the 90-day postoperative period. Other variables included trabecular thickness, trabecular distance and grey values, pain, swelling, and wound healing. A Wilcoxon test and a t-Student test were used at a 5% significance level and a Friedman test was used to multiple comparisons. RESULTS: Forty-four surgeries were performed in the present study. The patients' mean age was 22.41 (± 2.75 years) and 72.73% were women. PRF was associated to increased trabecular thickness and bone volume means (p < 0.001). The experimental group had significantly lower pain scores at 4h, 6h, 8h, 16h, 24h, and 72h (p ˂ 0.05). Mean swelling was lower on the experimental group (p < 0.001). The PRF group showed significant higher wound healing (p ˂ 0.001). CONCLUSIONS: Alveolar filling with PRF improves wound and bone healing after extractions while also decreasing pain and swelling in the postoperative period.

Chalcones with potential antibacterial and antibiofilm activities against periodontopathogenic bacteria.

OBJECTIVES: Periodontitis is a pathology resulting from complex interaction of microorganisms in the dental biofilm with the host's immune system. Increased use of antibiotics associated with their inappropriate use has increased resistance levels in anaerobic bacteria. Therefore, identifying new antimicrobial compounds, such as chalcones, is urgent. This study evaluates the antibacterial activity and the antibiofilm activity of 15 chalcones against the periodontopathogenic bacteria Prevotella nigrescens (ATCC 33563), P. oralis (ATCC 33269), Peptostreptococcus anaerobius (ATCC 27337), Actinomyces viscosus (ATCC 43146), Porphyromonas asaccharolytica (ATCC 25260), and Fusobacterium nucleatum (ATCC 25586). METHODS: The compounds were evaluated by minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC) tests. RESULTS: Compounds 1-6 showed good antibacterial and antibiofilm activities against most of the evaluated bacteria: MIC was lower than or equal to 6.25 µg/mL, biofilm biomass was reduced by 95%, and the compounds at concentrations between 0.78 and 100 µg/mL totally inhibited cell viability. Among the tested chalcones, 3 stood out: it was effective against all the bacteria, as revealed by the MIC and MBIC results. CONCLUSIONS: Our results have consolidated a base for the development of new studies on the effects of the tested chalcones as agents to combat and to prevent periodontitis.

Pigments from Antarctic bacteria and their biotechnological applications.

Pigments from microorganisms have triggered great interest in the market, mostly by their "natural" appeal, their favorable production conditions, in addition to the potential new chemical structures or naturally overproducing strains. They have been used in: food, feed, dairy, textile, pharmaceutical, and cosmetic industries. The high rate of pigment production in microorganisms recovered from Antarctica in response to selective pressures such as: high UV radiation, low temperatures, and freezing and thawing cycles makes this a unique biome which means that much of its biological heritage cannot be found elsewhere on the planet. This vast arsenal of pigmented molecules has different functions in bacteria and may exhibit different biotechnological activities, such as: extracellular sunscreens, photoprotective function, antimicrobial activity, biodegradability, etc. However, many challenges for the commercial use of these compounds have yet to be overcome, such as: the low stability of natural pigments in cosmetic formulations, the change in color when subjected to pH variations, the low yield and the high costs in their production. This review surveys the different types of natural pigments found in Antarctic bacteria, classifying them according to their chemical structure. Finally, we give an overview of the main pigments that are used commercially today.

Virulence Genes Profile and Antimicrobial Susceptibility of Community-Acquired Bacterial Urinary Tract Infections in a Brazilian Hospital.

Urinary tract infections (UTI) are one of the most common diseases worldwide and Escherichia coli is the most common causative bacteria. Empirical treatment is challenging due to antimicrobial or multidrug-resistance. The aims of this study were to determine the uropathogens and their antimicrobial susceptibility profile, as well as to identify the phylogroups and virulence genes of E. coli strains, associated with community-acquired UTI in outpatients admitted at a Brazilian Hospital in southeast Brazil. In total, 47 bacterial strains were isolated from 47 patients, 44 women and 2 men (no gender record from one patient). The age of the patients whose urine culture were positive varied from 0 (less than one month) to 104 years. Most of the isolates were E. coli (41/47), followed by Klebsiella pneumoniae (2/47), Klebsiella variicola/Klebsiella aerogenes (1/47), Pseudomonas aeruginosa (1/47), Proteus mirabilis (1/47), and Citrobacter koseri (1/47). Most E. coli strains were classified as phylogroup B2 (15/41 = 36.59%) and B1 (12/41 = 29.27%) and the most common virulence genes among E. coli strains were fimH (31/41 = 75.61%), iutA (21/41 = 51.22%), and tratT (16/41 = 39.02%). Among the E. coli strains, 59% were multidrug-resistance and strains that were ampicillin, sulfamethoxazole/trimethoprim, or tetracycline-resistant exhibited more chance to be multidrug-resistance, with an odds ratio of 100.00 [95% confidence interval (CI) 9.44-1059.26], 22.50 (95% CI 3.95-128.30), and 12.83 (95% CI 2.68-61.45), respectively. Our results showed that E. coli was the main etiological agent identified and demonstrated high frequency of multidrug-resistance and virulence factors in bacterial strains isolated from UTIs.

Antibacterial activity, cytocompatibility and effect of Bio-C Temp bioceramic intracanal medicament on osteoblast biology.

AIM: To analyse the antimicrobial and biological properties of a new bioceramic intracanal medicament (Bio-C Temp), and to compare it with two calcium hydroxide-based intracanal medicaments (Calen® and UltraCal® XS). METHODOLOGY: The direct contact and the crystal violet tests were performed to assess the antimicrobial activity of intracanal medicaments against Enterococcus faecalis. The cytocompatibility and the effect of the medication on the biology of the human osteoblast-like cell line (Saos-2) were evaluated with methylthiazole tetrazolium (MTT), neutral red, alkaline phosphatase activity and mineralization (alizarin red) assays. The data were analysed using one-way anova and Tukey's tests, two-way anova and Bonferroni's tests, or Kruskal-Wallis and Dunn's tests (α = 0.05). RESULTS: Bio-C Temp had significantly less antibacterial activity and biofilm biomass reduction than the other intracanal medicaments (P < 0.05). There was no difference in the viability of Saos-2 exposed to the various intracanal medicaments, except regarding the 1 : 2 dilution, when the Bio-C Temp group had significantly lower cell viability than the UltraCal® XS and Calen® groups (P < 0.05). Bio-C Temp induced significantly greater ALP activity than the other intracanal medicaments (P < 0.05) at day 1. Calen® induced significantly greater deposition of mineralized nodules than the other intracanal medicaments (P < 0.05), and no difference was observed between Bio-C Temp and UltraCal® XS (P > 0.05). CONCLUSIONS: Bio-C Temp had similar cytocompatibility at higher dilutions, and higher or similar induction of ALP activity and deposition of mineralized nodules in comparison with Calen® and UltraCal® XS. However, it had significantly less antibacterial and antibiofilm activity than Calen® and UltraCal® XS.

Pre-inoculation with arbuscular mycorrhizal fungi affects essential oil quality and the reproduction of root lesion nematode in Cymbopogon citratus.

Cymbopogon citratus (lemongrass) is an important medicinal and aromatic plant containing citral-rich essential oil, of which the quality and quantity may be affected by nematode infection. Research has shown that arbuscular mycorrhizal fungi (AMF) may act as nematode biocontrol agents and improve the chemical composition of plants. Three experiments were conducted to assess the effects of AMF inoculation on vegetative growth, essential oil composition, induction of defense-related proteins, and control of Pratylenchus brachyurus in C. citratus. Seedlings were transplanted into pots inoculated with one of two AMF species (Rhizophagus clarus or Claroideoglomus etunicatum). At 30 days after AMF inoculation, plants were inoculated with P. brachyurus. Evaluations were performed at 75 days after nematode inoculation. Although both AMF treatments led to effective root colonization (> 84%), fungus inoculation was not effective in reducing P. brachyurus population density. Nevertheless, C. etunicatum promoted an increase in shoot weight, and AMF treatments contributed to preserving essential oil composition in nematode-infected plants. In addition, both AMF treatments enhanced polyphenol oxidase activity and R. clarus increased peroxidase activity after nematode inoculation.

Tropical grass and legume pastures may alter lamb meat physical and chemical characteristics.

The present study assessed the influence of the type of the tropical pastures on lamb body weight (BW) gain and meat quality. Fifty-four lambs were allocated to three grazing pastures: (1) AG - Aruana grass (Panicum maximum cv. IZ-5); (2) PP - pigeon pea legume (Cajanus cajan cv. Anão); and (3) CS - contiguous swards, half of the paddock with AG and half with PP. After 92 days of grazing, the lambs were slaughtered. Carcasses were evaluated and the longissimus muscle was collected to determine color, lipid profile, tocopherol concentrations, and lipid oxidation. Although the pastures present differences in the characteristics of nutritional quality, the animals did not show difference in BW gain. The results show that all forage presented similar concentration of alpha-tocopherol (137 ± 14.37 mg kg-1 of fresh matter), whereas total and condensed tannin contents were greater in PP, intermediate in CS, and the lowest in AG treatment (P = 0.0001). Meat α-tocopherol content was similar among treatments (P = 0.1392), with an average concentration close to the optimal level to reduce the meat oxidation. Meat from AG treatment had 45 and 25% lower n-6/n-3 ratio than meat from PP and CS treatments, respectively. The legume increases the unsaturated fatty acids and the grass can reduce the n6/n3 ratio. The level of condensed tannin concentration did show to have important effect on meat characteristics. Both tropical pastures studied can provide a high amount of alpha-tocopherol, generating a great potential to increase the concentration of this antioxidant in lamb's meat.

Sugarcane cystatin CaneCPI-1 promotes osteogenic differentiation in human dental pulp cells: a new insight into cysteine proteases inhibitors.

AIM: To investigate the biocompatibility, type of cell death, osteogenic bioactivity and mRNA expression of the osteogenic markers, induced by CaneCPI-1 in human dental pulp cells (hDPCs). METHODOLOGY: hDPCs exposed to CaneCPI-1 and not exposed (control) were evaluated for cell viability by the 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay; apoptosis by flow cytometry; alkaline phosphatase (ALP) activity by calculation of thymolphthalein release; gene expression of bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (RUNX2), ALP, osteocalcin (OC), bone sialoprotein (BSP) by qPCR; and mineralized nodules production by using alizarin red staining. The data were analysed by one-way analysis of variance (anova) and Turkey's post-test, two-way anova and Bonferroni post-test or t-test (P < 0.05). RESULTS: CaneCPI-1 induced no apoptosis and had no cytotoxic effect, except in the concentration of 33.20 µm, in which cell viability was significantly lower than the control (α-MEM nonosteogenic medium serum-free) (P < 0.05). There was significantly greater ALP activity, greater expression of the BMP-2, RUNX2, ALP, OC and BSP genes and greater mineralized nodules production in the CaneCPI-1 group in comparison with the control or osteogenic α-MEM control (α-MEM osteogenic medium - L-ascorbic acid and ß-glycerophosphate) (P < 0.05). CONCLUSIONS: CaneCPI-1 was cytocompatible and also induced the differentiation of hDPCs in osteogenic phenotype in vitro. CaneCPI-1 is a promising molecule to induce pulp repair.

Effects of octenidine applied alone or mixed with sodium hypochlorite on eukaryotic cells.

AIM: To assess the effects of octenidine dihydrochloride (OCT) on eukaryotic cells and the cytotoxicity of OCT associated with sodium hypochlorite - NaOCl (NaOCl/OCT). METHODOLOGY: L929 fibroblasts and human osteoblast-like cells (Saos-2) were exposed to 0.1% OCT, 2% CHX, 2.5% NaOCl, 5.25% NaOCl and mixtures of 5.25% NaOCl and 0.1% OCT (NaOCl/OCT) at 90 : 10, 80 : 20 and 50 : 50 ratios. Cell viability was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red (NR) assays; type of cell death, by flow cytometry; cytoskeleton, by actin and α-tubulin fluorescence; and alkaline phosphatase (ALP) activity, by thymolphthalein release. The data were analysed by two-way ANOVA and Bonferroni tests (α = 0.05). RESULTS: MTT and NR assays revealed that 0.1% OCT had the lowest cytotoxicity (P < 0.05), followed by 2% CHX (P < 0.05). The 2.5% NaOCl, NaOCl/OCT 80 : 20 and NaOCl/OCT 50 : 50 solutions had intermediate cytotoxicity. NaOCl 5.25% and NaOCl/OCT 90 : 10 had the highest cytotoxicity (P < 0.05). The OCT group had a higher percentage of viable cells than the NaOCl and CHX groups (P < 0.05), and induced apoptosis at higher doses. The cytoskeleton alterations were observed at 0.12%, 0.6% and 2.02% for the NaOCl, CHX and OCT groups, respectively. The solutions did not induce ALP activity. CONCLUSION: Octenidine dihydrochloride was less cytotoxic, induced apoptosis at higher doses, caused few changes in the cytoskeleton and did not induce alkaline phosphatase activity. In addition, octenidine dihydrochloride reduced the cytotoxicity of 5.25% NaOCl when combined at 20 and 50%.

Structural and functional connectivity changes in response to short-term neurofeedback training with motor imagery.

Recent findings have been challenging current understanding of how fast the human brain change its structural and functional connections in response to training. One powerful way to deepen the inner workings of human brain plasticity is using neurofeedback (NFB) by fMRI, a technique that allows self-induced brain plasticity by means of modulating brain activity in real time. In the present randomized, double-blind and sham-controlled study, we use NFB to train healthy individuals to reinforce brain patterns related to motor execution while performing a motor imagery task, with no overt movement. After 1 h of NFB training, participants displayed increased fractional anisotropy (FA) in the sensorimotor segment of corpus callosum and increased functional connectivity of the sensorimotor resting state network. Increased functional connectivity was also observed in the default mode network. These results were not observed in the control group, which was trained with sham feedback. To our knowledge, this is the first demonstration of white matter FA changes following a very short training schedule (<1 h). Our results suggest that NFB by fMRI can be an interesting tool to explore dynamic aspects of brain plasticity and open new venues for investigating brain plasticity in healthy individuals and in neurological conditions.

Serological evidence of Borrelia circulation among blood donors in the São Paulo state, Brazil.

OBJECTIVE: The objective of this study was to examine the Borrelia seroprevalence among blood donors in Southeast Brazil. BACKGROUND: There is evidence that Borrelia spirochetes are circulating in Brazil; however, there are no studies that characterise these bacteria and investigate their seroprevalence in the Brazilian population. Such a situation, combined with a recent outbreak of tick-borne Rocky Mountain spotted fever in the São Paulo state demonstrates the increasing role of ticks as arthropod vectors in Brazil. METHODS: For the purpose of the study, 452 blood donors from Ribeirão Preto city, São Paulo state were tested using anti-Borrelia immunoglobulin G (IgG) assay. The positive results were also confirmed by Western blot for anti-borrelia IgM/IgG. RESULTS: The anti-Borrelia IgG enzyme-linked immunosorbent assay (ELISA) showed nine positive and nine borderline reactive samples, giving a total seroprevalence of 2·0% of anti-Borrelia IgG among Brazilian blood donors. The confirmation of the seropositive and borderline samples by Borrelia Western blot was demonstrated by IgG-positive results in 16 samples (a seroprevalence of 3.5%). Anti-Borrelia IgM antibodies were also detected in one sample. CONCLUSIONS: Our results demonstrate that Borrelia-like spirochetes may be circulating among blood donors from the São Paulo State and that the ticks have an important epidemiological role as vectors of bacterial infections in this Brazilian region. These results not only alert us to possible actions that might be undertaken in order to completely characterise the aetiological agents of Lyme-like syndromes in Brazil but also the possible impact that these bacterial agents might have on haemotherapy practices.

Anti-Trichomonas vaginalis activity of chalcone and amino-analogues.

Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer, and HIV acquisition. The current approved treatment present adverse effects and drug resistance data on this neglected parasitic infection is underestimated. Chalcones are a family of molecules that present biological applications, such as activity against many pathogenic organisms including protozoan pathogens. Chalcone (1) and three amino-analogues (2-4) were synthesized by Claisen-Schmidt condensation reaction and had their activity evaluated against the parasitic protozoan Trichomonas vaginalis. This bioassay indicated the presence and position of the amino group on ring A was crucial for anti-T. vaginalis activity. Among these, 3'-aminochalcone (3) presented the most potent effect and showed high cytotoxicity against human vaginal cells. On the other hand, 3 was not able to exhibit toxicity against Galleria mellonella larvae, as well as the hemolytic effect on human erythrocytes. Trophozoites of T. vaginalis were treated with 3, and did not present significant reactive oxygen species (ROS) accumulation, but induced a significantly higher ROS accumulation in human neutrophils after co-incubation. T. vaginalis pyruvate:ferredoxin oxidoreductase (PFOR) and ß-tubulin gene expression was not affected by 3.

Cytocompatibility, bioactive potential and antimicrobial activity of an experimental calcium silicate-based endodontic sealer.

AIM: To evaluate the cytocompatibility, bioactive potential, antimicrobial and antibiofilm activities of an experimental calcium silicate-based endodontic sealer, in comparison with TotalFill BC Sealer and AH Plus. METHODOLOGY: Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of the Saos-2 cells to the sealer extracts (1 : 2, 1 : 4, 1 : 8, 1 : 16 and 1 : 32 dilutions) for 24 h. The sealers were manipulated and placed in 12-well culture plates and exposed to ultraviolet light; then, 5 mL of DMEM without serum was added. Cell bioactivity was evaluated by alkaline phosphatase activity (ALP) and Alizarin red staining (ARS). Antimicrobial and antibiofilm activities were evaluated by direct contact test (DCT) on planktonic cells (DCTPC) and modified DCT on biofilm formed in bovine dentine blocks (MDCT). MTT, NR and ALP data were analysed by two-way anova and Bonferroni tests; ARS data by anova and Tukey's tests; and the microbiological data by Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: The experimental sealer, TotalFill BC and AH Plus were not cytotoxic to Saos-2, in comparison with the negative control (P > 0.05). Greater ALP was observed after 7 days of exposure of Saos-2 to AH Plus and the experimental sealer (P < 0.05) when compared to the control. Significantly greater mineralized nodule production was observed for TotalFill BC and the experimental sealer (P < 0.05). In DCTPC, the experimental sealer and TotalFill BC were associated with a significantly greater reduction of E. faecalis (P < 0.05) and eliminated C. albicans. In MDCT, the experimental sealer and TotalFill BC had significantly greater antibiofilm efficacy (P < 0.05). CONCLUSIONS: The experimental calcium silicate-based sealer was cytocompatible, bioactive, antimicrobial against E. faecalis and C. albicans and effective against E. faecalis biofilms, with potential for use in root canal treatment.

Heparin is biocompatible and can induce differentiation of human dental pulp cells.

AIM: To investigate the biocompatibility, osteogenic bioactivity and mRNA expression of the osteo/odontogenic markers bone morphogenetic protein 2 (BMP-2), osteocalcin (OC) and alkaline phosphatase (ALP), induced by heparin in human dental pulp cells (hDPCs). METHODOLOGY: hDPCs were exposed to the heparin, and cell viability was assessed by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT), and cell death was evaluated by flow cytometry. Osteogenic bioactivity was evaluated by the alkaline phosphatase (ALP) assay, and the detection of calcium deposits by alizarin red staining (ARS). The gene expression of BMP-2, OC and ALP was quantified with real-time PCR. Statistical analysis was performed with ANOVA and Bonferroni or Tukey post-test and t-test (α = 0.05). RESULTS: Heparin had no cytotoxic effect and did not induce apoptosis. After 3 days, heparin had significantly higher ALP activity in comparison with the control (P < 0.05). Heparin had a significant (P < 0.05) stimulatory effect on the formation of mineralized nodules. BMP-2 and OC mRNA expressions were significantly higher in cells exposed to heparin than control group after 1 day (P < 0.05). CONCLUSIONS: Heparin was biocompatible in hDPCs, induced osteogenic bioactivity and enhanced mRNA expression of osteo/odontogenic markers BMP-2 and OC. These results suggest that heparin has potential to induce osteo/odontogenic cell differentiation of hDPCs.

Anatomical danger zone reconsidered: a micro-CT study on dentine thickness in mandibular molars.

AIM: To investigate the smallest dentine thickness in mesial canals of mandibular molars along the cervical and middle thirds of the root by means of a micro-computed tomographic (micro-CT) technology and digital image analysis. METHODOLOGY: Fifty mesial roots of mandibular molars having two independent canals (mesiobuccal and mesiolingual), in the coronal and middle levels, were selected and scanned in a micro-CT device. After reconstruction procedures, approximately 468 slices per root covering the 7 mm below the furcation area of the mesial root were analysed to measure the smallest dentine thickness (danger zone [DZ]) in each slice from both distal and mesial regions of the mesial canals by an automatic segmentation process. RESULTS: The DZ values in the mesiobuccal canals varied from 0.67 to 1.93 mm, with an average of 1.13 ± 0.21 mm. For the mesiolingual canals, the DZ varied from 0.77 to 1.89 mm with an average of 1.10 ± 0.21 mm. There was no correspondence in the DZ between the mesiobuccal and mesiolingual canals at the same cross-sectional level in 71% of the specimens. Moreover, the smallest dentine thickness was towards the mesial region of the roots in 22% and 18% of the mesiolingual and mesiobuccal canals, respectively. (Figs 1 and 2 CONCLUSIONS: The smallest dentine thickness was on the mesial plane of the roots in about 40% of the canals. The vertical location of the DZ in relation to the furcation area was in the middle third of the root.

Effect of preemptive dexamethasone and etoricoxib on postoperative period following impacted third molar surgery - a randomized clinical trial.

BACKGROUND: The aim of this study was to compare the anti-inflammatory effects of dexamethasone and etoricoxib after third molar extraction. MATERIAL AND METHODS: A prospective, randomized, controlled, split-mouth study was conducted. 19 volunteers were allocated randomly to receive 90mg etoricoxib 1 hour prior to the procedure or 4mg intramuscular dexamethasone immediately after anesthesia. Baseline measurements were obtained preoperatively, and subsequent assessments were made on immediate postoperative, at 72 hours and 7 days after surgery to measure postoperative facial swelling by use of linear measurements, interincisal mouth opening width and visual analog scale score for pain. The amount of analgesics consumed was recorded. Descriptive statistics and the independent-samples t-test were used to compare the two groups at P < 0.05. RESULTS: Dexamethasone was effective in the control roasted edema for measurements of the mandibular angle - wing of the nose and mandibular angle - labial commissure 72 hours after surgery. And for the measurement mandibular angle - mentum, in the time of 72 hours and 7 days. There was no statistically significant difference in relation to pain and trismus. CONCLUSIONS: Considering significant results for some measures of the variable edema for the group that used intramuscular dexamethasone and the difference without statistical significance between groups for the other variables studied, we seem to reflect the intramuscular indication of the corticosteroid in a single dosage in relation to the use of etoricoxib as pre-emptive medication.

Species distribution, sequence types and antimicrobial resistance of Acinetobacter spp. from cystic fibrosis patients.

Acinetobacter spp. are important healthcare pathogens, being closely linked to antibiotic resistance and outbreaks worldwide. Although such species are rarely observed in patients with cystic fibrosis (CF), we describe the characteristics of 53 strains of Acinetobacter spp. isolated from the sputum of 39 Brazilian patients with CF. The species distribution was A. baumannii (n = 29), A. pittii (n = 13), A. nosocomialis (n = 8), A. seifertii (n = 1), A. soli (n = 1) and A. variabilis (n = 1) determined by partial rpoB gene sequencing. Sixteen strains (10 A. baumannii, 3 A. pittii and 3 A. nosocomialis) were multidrug-resistant (MDR) by disk diffusion test (30%) and eight MDR carbapenem-resistant A. baumannii strains harboured the bla OXA-23-like oxacillinase gene. Thirty-three sequence types (STs) were identified by multilocus sequence typing of which eight were novel (A. baumannii: 843, 844, 845, 847, 848; A. pitti: 643; A. nosocomialis: 862 and A. seifertii: 846); six STs (2 A. baumannii, 3 A. pittii and 1 A. nosocomialis) were found in more than one patient. Four strains of A. baumannii were assigned to two common clonal complexes (CCs), namely, CC1 (ST1, ST20 and ST160), and CC79 (ST79). This study underlines the extensive species diversity of Acinetobacter spp. strains in CF lung infections which may present difficulties for therapy due to significant antimicrobial resistance.

Effectiveness of XP-endo Finisher and XP-endo Finisher R in removing root filling remnants: a micro-CT study.

AIM: To evaluate the efficacy of filling material removal from oval-shaped canals after the use of supplementary files (XP-endo Finisher and XP-endo Finisher R) through microcomputed tomographic (micro-CT) analysis. METHODOLOGY: The root canals of twenty maxillary single-rooted teeth were prepared with Reciproc R25 files and filled with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. The root canals were then retreated using Reciproc R25 and R40 instruments. After this, the specimens were assigned to two groups according to the supplementary cleaning approach, using XP-endo Finisher and XP-endo Finisher R. The surface area and volume of removed filling material was assessed using micro-CT imaging before and after the use of the XP-endo instruments. Data were analysed statistically with a significance level of 5%. RESULTS: Removal of filling material at 66.8% and 59.4% in volume and 67.3% and 61.4% in surface area was seen for the XP-endo Finisher and the XP-endo Finisher R files, respectively. The amount of filling material removed by both supplementary files was highly significant (P = 0.000). No significant difference in the percentage of removed filling material was detected for the XP-endo instruments (P = 0.636 for volume and P = 0.667 for surface area). CONCLUSIONS: Both XP-endo files were equally effective in the removal of remaining filling material from straight oval-shaped canals. None of the instruments were able to remove all the residual filling material.

Cytotoxicity of peracetic acid: evaluation of effects on metabolism, structure and cell death.

AIM: To evaluate the cytotoxicity and the mechanism of cell aggression of peracetic acid (PA) in comparison with sodium hypochlorite (NaOCl). METHODOLOGY: L929 fibroblasts were exposed to 1% PA and 2.5% NaOCl, at several dilutions for 10 min. The following parameters were evaluated: cell metabolism by methylthiazol tetrazolium assay, external morphology by scanning electron microscopy, ultrastructure by transmission electron microscopy, the cytoskeleton by means of actin and α-tubulin labelling, and the type of cell death by flow cytometry (apoptosis/necrosis). The data were analysed by two-way anova and the Bonferroni post-test (α = 0.05). RESULTS: The PA group had lower cell viability and a higher percentage of necrotic cells than the NaOCl group (P < 0.05). Both solutions diminished cell metabolism, led to destructuring of the cytoskeleton, created changes in the external morphology, resulted in the accumulation of proteins in the rough endoplasmic reticulum and induced cell death predominantly by necrosis. However, these changes were observed in lower doses of PA when compared with NaOCl. CONCLUSIONS: Although they had the same mechanism of cytotoxicity, 1% PA had greater cytotoxic potential than 2.5% NaOCl.