Ricardo Dias de Castro

Anatomy and pathology of the masticator space

ObjectiveThis article reviews and illustrates the anatomy and pathology of the masticator space (MS).BackgroundPathology of the masticator space includes inflammatory conditions, vascular lesions, and tumours. Intrinsic tumours of this space can be benign and malignant, and they may arise from the mandibular ramus, the third division of the trigeminal nerve, or the mastication muscles. Malignant tumours may appear well defined and confined by the masticator fascia, without imaging signs of aggressive extension into neighbouring soft tissues. Secondary invasion of the masticator space can also occur with tumours of the nasopharynx, oropharynx, oral cavity, and parotid glands. Perineural tumour spread (PNS), especially along the trigeminal nerve, can also occur with masticator space malignancies.ConclusionMasses of the MS are difficult to evaluate clinically, and computed tomographic (CT) and magnetic resonance (MR) images are essential for the diagnosis and characterisation of these lesions. Malignant tumours may appear well defined and confined by the fascia. Thus, when a mass is identified, a biopsy should be done promptly. PNS may occur in tumours involving the MS and its recognition on imaging studies is essential to plan the appropriate treatment.Teaching points• Differentiating between intrinsic and extrinsic lesions is essential to the differential diagnosis• Infections of the MS may cross the fascia and mimic neoplasms on imaging studies• Malignant tumours may show no aggressive signs, such as bone erosion or violation of the fascia• Perineural spread (PNS) is often clinically silent and frequently missed at imaging and leads to tumour recurrence

Antifungal activity, mode of action and anti-biofilm effects of Laurus nobilis Linnaeus essential oil against Candida spp.

OBJECTIVE The present study demonstrated the antifungal potential of the chemically characterized essential oil (EO) of Laurus nobilis L. (bay laurel) against Candida spp. biofilm adhesion and formation, and further established its mode of action on C. albicans. METHODS L. nobilis EO was obtained and tested for its minimum inhibitory and fungicidal concentrations (MIC/MFC) against Candida spp., as well as for interaction with cell wall biosynthesis and membrane ionic permeability. Then we evaluated its effects on the adhesion, formation, and reduction of 48hC. albicans biofilms. The EO phytochemical profile was determined by gas chromatography coupled to mass spectrometry (GC/MS). RESULTS The MIC and MFC values of the EO ranged from (250 to 500) μg/mL. The MIC values increased in the presence of sorbitol (osmotic protector) and ergosterol, which indicates that the EO may affect cell wall biosynthesis and membrane ionic permeability, respectively. At 2 MIC the EO disrupted initial adhesion of C. albicans biofilms (p<0.05) and affected biofilm formation with no difference compared to nystatin (p>0.05). When applied for 1min, every 8h, for 24h and 48h, the EO reduced the amount of C. albicans mature biofilm with no difference in relation to nystatin (p>0.05). The phytochemical analysis identified isoeugenol as the major compound (53.49%) in the sample. CONCLUSIONS L. nobilis EO has antifungal activity probably due to monoterpenes and sesquiterpenes in its composition. This EO may affect cell wall biosynthesis and membrane permeability, and showed deleterious effects against C. albicans biofilms.

Effect of Schinus terebinthifolius on Candida albicans growth kinetics, cell wall formation and micromorphology.

Abstract Objective: To evaluate the anti-fungal activity of a tincture from Schinus terebinthifolius (Brazilian pepper tree) on Candida albicans (ATCC 289065), a micro-organism associated with fungal infections of the oral cavity. Materials and methods: Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) were determined through microdilution technique, as well as the microbial growth curve of C. albicans promoted by S. terebinthifolius. In addition, this study investigated a possible activity of the product on the fungal cell wall and its biological activity on fungal morphology. Nystatin was used as control and all tests were performed in triplicate. Results: S. terebinthifolius showed MIC of 312.5 µg/mL and MFC of 2500 µg/mL upon the strain tested, while Nystatin showed MIC and MFC of 6.25 µg/mL. As regards the microbial growth curve, S. terebinthifolius was able to significantly reduce the number of CFU/mL when compared to growth control until the time of 60 min. In the times 120 and 180 min there was no statistically significant difference between the growth control and the experimental product. S. terebinthifolius possibly acts on the fungal cell wall, once the sorbitol test indicated a MIC of 1250 µg/mL. In the fungal morphology, a reduction was observed of pseudo-hyphae, chlamydoconidia and blastoconidia in the presence of the experimental product. Conclusion: S. terebinthifolius showed anti-fungal activity against C. albicans, inhibiting, probably, the fungal cell wall formation.

Alternative Animal and Non-Animal Models for Drug Discovery and Development: Bonus or Burden?

Mammalian models have served as a basis for R&D over the past decades. Nevertheless, these models are expensive, laborious, may yield results that cannot always be translated into the human in vivo situation and, more recently, have reverberated great social and ethical dilemmas. Hence, the prospect of changes in the global scientific scenario and the Three Rs principle (Reduction, Replacement and Refinement) have encouraged the development of alternative methods to the use of mammals. Despite the efforts, suitable alternative tests are not available in all areas of biomedical research, as regulatory acceptance requires time, prior validation and robust financial and scientific investment. In this perspective, we aim to shed light on the concepts, challenges and perspectives for implementation of innovative alternative animal and non-animal methods in scientific research. The applicability and meaningfulness of invertebrate animal models, in silico analysis and reverse pharmacology are discussed, among other aspects of relevance in today’s scenario. Overall, the use of alternative models, including Artemia salina (brine shrimp), Caenorhabditis elegans (roundworm), Danio rerio (zebra fish), Drosophila melanogaster (fruit fly), Galleria mellonella (greater waxmoth) and in silico modelling, increased 909% from 1990 to 2015, as compared to 154% of conventional mammals in the same period. Thus, technological and scientific advancements in the fields of toxicology and drug development seem to have diminished the need for mammalian models. Today, however, mammals still remain critically indispensable to provide – in most cases –reliable data subsidizing and validating translation into the clinical setting.

Antifungal Activity of Apple Cider Vinegar on Candida Species Involved in Denture Stomatitis

PURPOSE To evaluate the in vitro antifungal activity of apple cider vinegar on Candida spp. involved in denture stomatitis. MATERIAL AND METHODS The microdilution technique was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of apple cider vinegar containing 4% maleic acid, and nystatin (control). Further tests of microbial kinetics and inhibition of adherence to acrylic resin were performed testing different concentrations (MIC, MICx2, MICx4) of the products at time intervals of 0, 30, 60, 120 and 180 minutes. A roughness meter was used to measure the changes in surface roughness; color change of the acrylic resin specimens exposed to the test products in different concentrations and time intervals were also evaluated. RESULTS Apple cider vinegar (4%) showed MIC of 2500 μg/ml and MFC of 2500, 5000, and 10,000 μg/ml depending on the strain tested. Nystatin showed MIC of 3.125 μg/ml and strain-dependent MFC values ranging from 3.125 to 12.5 μg/ml. The microbial kinetic assay showed a statistical difference between apple cider vinegar and nystatin (p < 0.0001). After 30 minutes of exposure, apple cider vinegar showed fungicidal effect at MICx4, whereas nystatin maintained its fungistatic effect. Apple cider vinegar showed greater inhibition of adherence (p < 0.001) compared to control. Apple cider vinegar did not significantly alter the surface roughness of the acrylic resin specimens compared to nystatin (p > 0.05), and both had no influence on their color. CONCLUSION Apple cider vinegar showed antifungal properties against Candida spp., thus representing a possible therapeutic alternative for patients with denture stomatitis.

Does Scientific Evidence for the Use of Natural Products in the Treatment of Oral Candidiasis Exist? A Systematic Review

In view of the limitations of antifungal agents used in the treatment of oral candidiasis and the wide variety of natural products that have been studied as treatment of this disease, this systematic literature review proposed to evaluate whether scientific evidence attesting to the efficacy of natural products in the treatment of this disease exists. A systematic search in PubMed, MEDLINE, SciELO, Lilacs, and Cochrane Library databases was accomplished using the associations among the keywords Candida albicans, phytotherapy, biological products, denture stomatitis, and oral candidiasis in both English and Portuguese. Four independent observers evaluated the methodological quality of the resulting articles. Three studies were included for detailed analysis and evaluated according to the analysis protocol based on the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The tested products were different in all studies. Two studies mentioned random samples, but no study described the sample allocation. No study mentioned sample calculations, a prior pilot study, or examiner calibration, and only one trial reported sample losses. Differences between the tested products and the methodological designs among these studies did not allow the existence of scientific evidence related to the effectiveness of these products for the proposed subjects to be confirmed.

Caracterização Social dos Pacientes Atendidos na Disciplina de Clínica Integrada da Faculdade de Odontologia de Araçatuba, UNESP

Objective: To establish the social profile of the patients treated at the undergraduate clinic of the Discipline of Integrated Clinic of the Dental School of...

Atividade antifúngica de óleos essenciais frente a amostras clínicas de Candida albicans isoladas de pacientes HIV positivos

The aim of this study was to evaluate the antifungal activity of essential oils from Ocimum basilicum L. (basil), Cymbopogon martinii L. (palmarosa), Thymus vulgaris L. (thyme) and Cinnamomum cassia Blume (Chinese cinnamon) against Candida albicans strains isolated from HIV-positive patients and the standard strain (ATCC 76845). Fifteen clinical samples of C. albicans (C1-C15) were subcultured in Sabouraud Dextrose agar to prepare suspensions in sterile saline solution (0.9%) containing 1.5 x 106 CFU mL-1. The emulsions of essential oils were prepared in sterile distilled water and Tween 80, with concentrations ranging between 1024 µg mL-1 and 4 µg mL-1. The antifungal action was determined by means of the Minimum Inhibitory Concentration (MIC), using the microdilution technique. Nystatin and miconazole (50 µg mL-1) were used as positive controls. The tests were performed in triplicate and the MIC was the lowest concentration capable of inhibiting the growth of yeasts, which was observed by the visual method, according to the turbidity of the culture medium. For C. albicans (ATCC 76845), the MIC of C. cassia essential oil was 64 µg mL-1, while the MIC for C. martini was 1024 µg mL-1. Considering the clinical strains, the MIC of C. cassia was 64 µg mL-1 for 80% of the strains, and the variation in MIC values was between 128 µg mL-1 and 64 µg mL-1. For 66.6% of the clinical samples, the MIC of C. matinii was 612 µg mL-1. Nystatin did not present activity against the clinical strains (C1-C15), while the antifungal activity of miconazole was noticed for 100% of the samples. The antimicobrial activity of essential oils from O. basilicum and T. vulgaris was not identified at the evaluated concentrations. It was concluded that the essential oils from C. cassia and C. martinii, at different concentrations, presented antifungal activity against C. albicans strains isolated from HIV-positive patients and the standard strain (ATCC 76845). However, antifungal activity was not observed for the essential oils from O. basilicum and T. vulgaris.

Temporomandibular disorder is more prevalent among patients with primary headaches in a tertiary outpatient clinic

OBJECTIVE The aim of this study was to estimate the prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients with primary headaches attended in a tertiary neurology ambulatory. METHOD Authorized by the Ethics Committee, the present cross-sectional study was conducted with a random sample of patients screened for orofacial pain and primary headaches at a tertiary hospital in Northeast of Brazil. RESULTS The sample consisted in 42 patients with primary headache, 59.5% male. The prevalence of > 6 TMD signs and symptoms was 54.8%. In those patients with migraine TMD was present in 71.4% and in tension-type headache in 38.1% (p = 0.030; OR = 4.1). TMD was related to the clinical status of headache associated or attributed to medication overuse (p = 0.001). CONCLUSION TMD has a high prevalence in patients with primary headaches (54.8%). Special attention must be given to patients with migraine and headache associated or attributed to medication overuse.

ATIVIDADE ANTIBACTERIANA IN VITRO DE FITOCONSTITUINTES SOBRE MICORGANISMOS DO BIOFILME DENTÁRIO

Objective: To evaluate the in vitro antibacterial activity of citronellol, linalool, thymol, and D-limonene against Streptococcus mutans, S. salivarius and S. oralis. Material and Methods: It was performed a screening by the diffusion technique on solid medium. Absorbent paper discs were soaked with 30 µl of the tested substance and then placed on petri dishes containing Mueller Hinton agar previously sown with the bacterial inoculum. After incubation for 24 h at 37 °C, it was measured the halo of growth inhibition with the aid of a manual caliper. Chlorhexidine (2%) was used as positive control. Tests were performed in triplicate. Results: For citronellol, the means of the diameters of the halos, in millimeters (mm), were 10.7, 10.0, and 9.8 against S. mutans, S. salivarius and S. oralis respectively. The values found for thymol were 7.3, 7.3 and 8.3 mm, respectively. The phytochemical D-limonene exhibited means of 8.0, 6.7 and 6.0 mm, respectively. For linalool, the means of the halos were 8.0 mm, 9.0 mm and 8.2 mm. Chlorhexidine was found to show means of 17, 16.8 and 19.7 mm on S. mutans, S. oralis and S. salivarius respectively. Conclusion: The products under test showed antibacterial activity, being therefore potential substances to be applied for dental caries prevention. DESCRIPTORS: Biological Agents. Streptococcus mutans. Streptococcus oralis.