Influence of etchant type on the shear bond strength of orthodontic brackets to enamel.

The aim of this study was to evaluate the influence of the type of etchant on the shear bond strength (SBS) of metallic brackets to enamel and the Adhesive Remnant Index (ARI) after debonding. A total of 30 mandibular and maxillary premolars were randomly distributed into groups (n = 10) treated with 1 of 3 enamel surface-conditioning agents: 35% phosphoric acid (PA), 35% glycolic acid (GA), or 35% ferulic acid (FA). The designated acid was applied to the buccal enamel surface of the tooth for 20 seconds, and the tooth was then rinsed with distilled water for 20 seconds and air dried for 5 seconds. A metal bracket was bonded to the prepared surface with light-cured orthodontic resin. After 24 hours, the bracket-tooth interface was submitted to SBS testing in a universal testing machine at a speed of 0.5 mm/min. After debonding, the enamel surface was observed under a stereomicroscope (×20 magnification) to determine the ARI. The generalized linear models showed that the PA and GA groups presented significantly higher SBSs than the FA group (P = 0.0003). The ARI was significantly higher in specimens treated with PA than with the other acids (P < 0.05; Kruskal-Wallis and Dunn tests), with a larger quantity of adhesive remaining adhered to the tooth. Both PA and GA are effective for bonding brackets, but GA resulted in a lower percentage of adhesive remnant adhered to the enamel.

Benign odontogenic ghost cell lesions revisited and new considerations on dysplastic dentin.

OBJECTIVES: This study aimed to revisit benign odontogenic ghost cell lesions (BOGCL) by hematoxylin and eosin staining and immunohistochemistry. MATERIALS AND METHODS: Thirty cases of calcifying odontogenic cyst (COC) and 6 cases of dentinogenic ghost cell tumor (DGCT) were selected for histopathological and immunohistochemical analysis. Sections stained for cytokeratin (K) 14, K-19, amelogenin, collagen type 1 (COL-1), and dentin matrix acidic phosphoprotein 1 (DMP-1) were evaluated using qualitative analysis. Sections stained for Ki-67 and minichromosome maintenance protein-2 (MCM-2) were evaluated using semi-quantitative analysis. RESULTS: A morphologic overlap was noticed in all BOGCL. Moreover, no differences were detected in the expression of K-14 and K-19. The expression of proliferative markers Ki-67 and MCM-2 was similar between cystic and tumor lesions (p > .05). The presence of COL-1 and absence of amelogenin in the so-called dysplastic dentin, associated with its histologic pattern, suggest that this is in fact an enameloid-like tissue. CONCLUSIONS: The dysplastic dentin should be considered an enameloid-like tissue in these lesions. CLINICAL RELEVANCE: The similarity in histology, protein expression, and proliferative marker indices between COC and DGCT suggest that they are a sole entity and likely represent types of the same neoplasia.

Homologous transplantation with fresh frozen bone for dental implant placement can induce HLA sensitization: a preliminary study.

It has been related in orthopedic surgeries the HLA sensitization. Thus, we evaluate if the use of fresh-frozen homologous bone (FFHB) for dental implant placement induce anti-HLA sensitization. Six patients were treated with FFHB corticocancellous block grafts. After 6 months, bone biopsies were harvested during implant placement to allow histomorphometric analysis. Vital mineralized tissue (VMT), non-vital mineralized tissue (NVMT) and non-mineralized tissue (NMT) were quantified histomorphometrically. Peripheral blood was collected from the patients before FFHB placement and 6 months after the surgery for anti-HLA analysis. The histomorphometric analysis showed the presence of VMT, NVMT and NMT in 45.56 ± 15.72 %, 14.16 ± 13.39 % and 40.29 ± 12.60 %, respectively. The baseline and 6 months postoperative CTs revealed bone thickness in the order of 5.66 ± 0.67 mm and 8.71 ± 1.52 mm (3.05 ± 1.39 mm). The anti-HLA analysis revealed that two of the six patients (33.3 %) became sensitized, however this was not associated with any FFHB incorporation loss (p > 0.05). A total of 24 implants were placed all of which were osseointegrated after 6 months. Although FFHB-related HLA sensitization does not appear to affect bone incorporation when treating insufficient bone thickness for implant placement, further follow-up is required to determine whether there is an association between HLA sensitization and long-term graft survival.

MARPE expander activation load with different configurations of extender arms heights: in-vitro evaluation.

OBJECTIVE: Evaluate the load mini-implants exert on the artificial bone when expanding the MARPE EX in three different extension arm configurations. METHODS: A device simulating the human palate was fabricated and attached to a universal testing machine, for conducting tests with different MARPE expanders (n=5): non-adjustable/control (MARPE SL, Peclab) or with low, intermediate, and high extender arms (MARPE EX, Peclab). The expanders were manually activated until failure of the device occurred, and maximum load values were recorded. Load averages were also calculated for every five activations until the twentieth activation. RESULTS: The generalized linear mixed model for repeated measures over time showed that there was significant increase in load with activations for all expanders (p=0.0004). Up to the twentieth activation, the expander with low extender arms presented higher load than the others, while the expander with high extender arms showed lower load values (p<0.05). There was no significant difference among expanders regarding the number of activations (p=0.0586), although there was a trend towards fewer activations until fracture for the control expander. It was observed that the higher the configuration, the lower the force the mini-implants delivered to the bone. The control expander provided a force magnitude similar to that of the adjustable expander when positioned at the intermediate height. CONCLUSIONS: The activation load of MARPE expanders is influenced by the type of presentation of the extensor arms, with higher configurations resulting in lower force delivered by the mini-implants to the bone.

In vitro evaluation of the suppressor potential of conditioned medium from benign myoepithelial cells from pleomorphic adenoma in malignant cell invasion.

Tumoral invasion process is the result of a complex interaction between the tumor cells and microenvironment which plays an important role in modulating the growth and invasion of the cancer. The myoepithelial cells, present in glandular organs such as the breast and salivary glands, seem to exert paracrine effects on the glandular epithelium, acting as natural tumor suppressors. To verify the influence of the benign myoepithelial cells in the invasion of malignant cells, simulating an in situ carcinoma ex pleomorphic adenoma, we have cultured three different high-potential invasive malignant tumors (breast ductal adenocarcinoma, melanoma and oral squamous cell carcinoma) in conditioned medium of myoepithelial cells from salivary gland pleomorphic adenomas using transwell chambers with 8-µm pores membrane coated with matrigel. After 96 h, quantitative analyses of the results were performed by calculating the invasion index (number of cells that invaded in relation to the total number of cells). The results showed that there was a reduction of the invasion index mean for the three different malignant tumors. This study supports a tumoral suppressor function of the myoepithelial cells from pleomorphic adenoma in in vitro invasion process.

Assessment of a Biosafety Device to Control Contamination by Airborne Transmission during Orthodontic/Dental Procedures.

During the COVID-19 pandemic, dental professionals have faced high risk of airborne contamination between dentists, staff, and patients. The objective of this study was to evaluate the effect of an individual biosafety capsule in dentistry (IBCD) on reducing the dispersion of droplets and aerosols during orthodontic treatment and evaluate the clinician and patient's perception of using the IBCD. For the in-vitro part of the study, aerosol quantification was performed with and without the IBCD, using a nonpathogenic bacterial strain and viral strain in the reservoir and high-speed dental handpiece. Petri dishes with MRS agar were positioned from the head of the equipment at distances of 0.5, 1, and 1.5 m. After 15 minutes of passive aerosol sampling, the dishes were closed and incubated using standard aerobic conditions at 37°C for 48 hours to count colony forming units (CFUs). For the clinical part of the study, a questionnaire was sent to clinicians and patients to understand their perception of orthodontically treat and receive treatment using the barrier. The use of IBCD showed an effective means to reduce the dispersion of bacterial and viral contamination around 99% and 96%, respectively, around the main source of aerosol (p < 0.05). Clinical results showed a 97% bacterial reduction during patient's consultations (p < 0.05). The vast majority of clinicians and patients understand the importance of controlling the airborne dispersion to avoid contamination.

Influence of apical preparation size and final irrigation protocol on the debridement of oval root canals.

This study assessed the influence of apical preparation size and final irrigation protocol on the debridement of the apical third of oval root canals of mandibular molars. Seventy-seven distal roots were divided into 7 groups (n = 11): Control: without instrumentation or irrigation; Group 30CI: ProTaper Next (up to size 30; PTN) + conventional irrigation (CI); Group 30UAI: PTN + ultrasonically activated irrigation (UAI); Group 30XPF: PTN + XP-endo Finisher (XPF); Group 40CI: PTN + ProDesign Logic (up to size 40; PDL) + CI; Group 40UAI: PTN + PDL + UAI; and Group 40XPF: PTN + PDL + XPF. The total volume of irrigating solutions used per root canal in all the experimental groups was 33 mL of 2.5% sodium hypochlorite (NaOCl) and 6 mL of 17% ethylenediaminetetraacetic acid (EDTA). After specimen processing and histological analysis under a digital microscope (100x), the percentages of untouched canal walls (UCW) and remaining debris (RD) were assessed using Image J software. A descriptive and exploratory analysis was conducted, indicating that the data failed to meet the assumptions of an analysis of variance. Therefore, generalized linear models were used to assess the effects of the different instrumentation and irrigation protocols, as well as the interaction among them, on the percentage of UCW and RD. No significant difference was found among the irrigation protocols regarding the percentage of UCW, irrespective of apical preparation size (p>0.05). However, UCW and RD were significantly lower in groups 40CI, 40UAI and 40XPF than in groups 30CI, 30UAI and 30XPF (p<0.05). The percentage of RD was significantly lower in the UAI and XPF groups than in the CI groups, irrespective of apical preparation size (p<0.05). The difference between preparation sizes 30 and 40, with respect to RD, was higher when CI was used (p<0.05). In conclusion, instrumentation up to apical preparation size 40 resulted in lower percentages of UCW and RD than up to apical preparation size 30. Use of UAI or XPF resulted in lower percentages of RD than CI.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips.

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 108 CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Biosafety devices to control the spread of potentially contaminated dispersion particles. New associated strategies for health environments.

Dental procedures produce a large amount of spatter and aerosols that create concern for the transmission of airborne diseases, such as Covid-19. This study established a methodology with the objective of evaluating new associated strategies to reduce the risk of cross-transmission in a health environment by simulating spread of potentially contaminated dispersion particles (PCDP) in the environment. This crossover study, was conducted in a school clinic environment (4 clinics containing 12 dental chairs each). As a positive control group (without barriers), 12 professionals activated at the same time the turbine of dental drill, for one minute, with a bacterial solution (Lactobacillus casei Shirota, 1.5x108 CFU/mL), which had been added in the cooling reservoir of the dental equipment. In the experimental groups, the professionals made use of; a) an individual biosafety barrier in dentistry (IBBD) which consists of a metal support covered by a disposable PVC film barrier; b) a Mobile Unit of Disinfection by Ultraviolet-C, consisting of 8 UV lamps-C of 95W, of 304µW/cm2 of irradiance each, connected for 15 minutes (UV-C) and; c) the association between the two methods (IBBD + UV-C). In each clinic, 56 Petri dishes containing MRS agar were positioned on the lamps, benches and on the floor. In addition, plates were placed prior to each test (negative control group) and plates were also placed in the corridor that connects the four clinics. In the groups without barrier and IBBD + UV-C the passive air microorganisms in Petri dishes was also evaluated at times of 30, 60, 90 and 120 minutes after the end of the dental's drill activation. The mean (standard deviation) of CFU of L. casei Shirota for the positive control group was 3905 (1521), while in the experimental groups the mean using the IBBD was 940 (466) CFU, establishing a reduction on average, of 75% (p<0.0001). For the UV-C group, the mean was 260 (309) CFU and the association of the use of IBBD + UV-C promoted an overall average count of 152 (257) CFU, establishing a reduction on average of 93% and 96%, respectively (p<0.0001). Considering these results and the study model used, the individual biosafety barrier associated with UV-C technology showed to be efficient strategies to reduce the dispersion of bioaerosols generated in an environment with high rate of PCDP generation and may be an alternative for the improvement of biosafety in different healthy environment.

Unusual Case of Graphite Tattoo in a Pediatric Patient: Clinical Presentation and Differential Diagnosis.

Graphite tattoo, a rare finding in children, is characterized by a localized blue-grey macule of variable sizes and shapes. Intraoral graphite implantation may cause this pigmentation through accidental injury with a graphite pencil. The purpose of this paper is to report an unusual case of graphite tattoo involving the anterior palate region in a seven-year-old girl. A diagnosis was made based on clinical and radiographic examinations and histopathology features. This report also highlights the importance of differential diagnosis and management of oral benign and malignant pigmented lesions in children.

Epidermal cyst: a rare case report in a 5-month-old child / Cisto epidérmico: relato de caso raro em criança de 5 meses

ABSTRACT The epidermal cyst is a rare, benign lesion, usually asymptomatic and slowly enlarging, more frequently located in the submandibular region. Its etiology is believed to be associated with the epithelial residual tissues retained in the midline during the closure of the first and second brachial arches, in the third and fourth weeks of intra-uterine life. Its clinical characteristics are of a rubbery consistency to palpation, well defined borders, with the absence of skin appendages within their squamous epithelium lined walls. The final diagnosis is confirmed through histopathological examination with stratified squamous epithelium findings in the cystic fluid lumen or keratin. The treatment is usually surgical and without recurrence and the final diagnosis is confirmed through histopathological examination. This paper aims to present a case report of a congenital epidermal cyst in a 5-month-old female patient located in the mouth floor near the sublingual gland duct. The case was treated with excisional biopsy and after follow-up, there was no recurrence.

RESUMO O cisto epidérmico é um cisto de desenvolvimento, benigno, raro, localizado com maior frequência na região submandibular, geralmente assintomático e de evolução lenta. Acredita-se que a sua etiologia esteja associada aos restos epiteliais retidos na linha média durante o fechamento do primeiro e segundo arcos braquiais, na terceira ou quarta semana de vida intrauterina. Suas características clínicas são de uma consistência borrachóide à palpação, bordas delimitadas e sem apêndices de pele no seu interior. O diagnóstico é confirmado através do exame histopatológico com achados de epitélio escamoso estratificado e no lúmen fluído cístico ou queratina. O tratamento é geralmente cirúrgico e sem recidivas. Este trabalho relata um caso de cisto epidérmico congênito de uma paciente pediátrica, do sexo feminino, de cinco meses de idade e localizado no assoalho de boca próximo ao ducto da glândula sublingual. O caso foi tratado com a enucleação cirúrgica e em seis meses de acompanhamento não apresentou recidiva.

Establishment of a primary culture of polymorphous low grade adenocarcinoma cells.

OBJECTIVE: The aim of the present study was to establish a primary cell culture derived from polymorphous low grade adenocarcinoma (PLGA). DESIGN: The neoplastic cells were derived from a 57-year-old female patient diagnosed with PLGA. A fragment of the tumor was collected and submitted to enzymatic digestion followed by centrifugation on a Percoll gradient. The cell population was characterized by means of immunofluorescence and detection of PRKD1 gene mutations. RESULTS: Epifluorescence analysis of the primary culture revealed that the malignant epithelial cells were predominantly polygonal in shape and positive for cytokeratin 7, vimentin, and S100. The doubling time of the cell culture was 86.73h. The restriction digestion assay showed that the neoplastic cells possess PRKD1 gene mutations. CONCLUSION: The establishment of primary cell culture derived from PLGA should be considered a useful tool for molecular analysis of this salivary gland tumor.

Extramedullary Plasmacytoma Diagnosed in an HIV-Positive Patient by an Unusual Clinical Presentation.

The aim of this paper is to describe a case report of EMP in an HIV-positive patient. A 44-year-old, dark-skinned HIV-infected woman was referred to the Oral Diseases Treatment Center with a swelling at palate and left gingival fornix in the maxilla. Biopsy was taken and the oral lesion was diagnosed as EMP with well-differentiated plasma cells and restriction of the lambda light-chain. Skeletal survey was performed and no radiograph alterations were observed, thus supporting the diagnosis of EMP. Patient was referred to treatment and after two months of chemo and radiotherapy, an expanding lesion was observed in L5/S1 patient's vertebrae. Biopsy of the spinal lesion was consistent with lymphoma with plasmocitary differentiation, supporting the diagnosis of multiple myeloma (MM). Regarding the medical history, the final diagnostic was an oral extramedullary plasmacytoma with rapid progression into multiple myeloma. It is crucial to emphasize the relevance of HIV infection as a risk factor for both aggressive clinical behavior and unusual clinical presentation of extramedullary plasmacytoma cases.

Influence of apical preparation size and final irrigation protocol on the debridement of oval root canals

Abstract This study assessed the influence of apical preparation size and final irrigation protocol on the debridement of the apical third of oval root canals of mandibular molars. Seventy-seven distal roots were divided into 7 groups (n = 11): Control: without instrumentation or irrigation; Group 30CI: ProTaper Next (up to size 30; PTN) + conventional irrigation (CI); Group 30UAI: PTN + ultrasonically activated irrigation (UAI); Group 30XPF: PTN + XP-endo Finisher (XPF); Group 40CI: PTN + ProDesign Logic (up to size 40; PDL) + CI; Group 40UAI: PTN + PDL + UAI; and Group 40XPF: PTN + PDL + XPF. The total volume of irrigating solutions used per root canal in all the experimental groups was 33 mL of 2.5% sodium hypochlorite (NaOCl) and 6 mL of 17% ethylenediaminetetraacetic acid (EDTA). After specimen processing and histological analysis under a digital microscope (100x), the percentages of untouched canal walls (UCW) and remaining debris (RD) were assessed using Image J software. A descriptive and exploratory analysis was conducted, indicating that the data failed to meet the assumptions of an analysis of variance. Therefore, generalized linear models were used to assess the effects of the different instrumentation and irrigation protocols, as well as the interaction among them, on the percentage of UCW and RD. No significant difference was found among the irrigation protocols regarding the percentage of UCW, irrespective of apical preparation size (p>0.05). However, UCW and RD were significantly lower in groups 40CI, 40UAI and 40XPF than in groups 30CI, 30UAI and 30XPF (p<0.05). The percentage of RD was significantly lower in the UAI and XPF groups than in the CI groups, irrespective of apical preparation size (p<0.05). The difference between preparation sizes 30 and 40, with respect to RD, was higher when CI was used (p<0.05). In conclusion, instrumentation up to apical preparation size 40 resulted in lower percentages of UCW and RD than up to apical preparation size 30. Use of UAI or XPF resulted in lower percentages of RD than CI.

Resumo Este estudo avaliou a influência do tamanho do preparo apical e do protocolo de irrigação final sobre o debridamento do terço apical de canais radiculares ovais de molares inferiores. Setenta e sete raízes distais foram selecionadas e divididas em 7 grupos (n = 11): Grupo controle: sem instrumentação nem irrigação; Grupo 30IC, ProTaper Next (até o tamanho 30; PTN) + irrigação convencional (IC); Grupo 30IAU, PTN + irrigação ativada ultrassonicamente (IAU); Grupo 30XPF, PTN + XP-endo Finisher (XPF); Grupo 40IC, PTN + ProDesign Logic (até o tamanho 40; PDL) + IC; Grupo 40IAU, PTN + PDL + IAU; e Grupo 40XPF, PTN + PDL + XPF. Os volumes totais dos irrigantes utilizados por canal radicular em todos os grupos experimentais foram 33 mL de hipoclorito de sódio (NaOCl) a 2,5% e 6 mL de ácido etilenodiamino tetracético (EDTA) a 17%. Após o processamento dos espécimes e a análise das secções histológicas sob um microscópio digital (100x), as porcentagens de paredes não instrumentadas (PNI) e detritos remanescentes (DR) foram avaliadas utilizando-se o software Image J. Uma análise descritiva e exploratória foi realizada, indicando que os dados não atenderam aos pressupostos de uma análise de variância. Modelos lineares generalizados foram, portanto, utilizados para avaliar os efeitos dos diferentes protocolos de instrumentação e irrigação, bem como da interação entre eles, sobre as porcentagens de PNI e DR. Não houve diferença significativa entre os protocolos de irrigação final quanto à porcentagem de PNI, independentemente do tamanho do preparo apical (p>0,05). Entretanto, as porcentagens de PNI e DR foram significativamente menores nos grupos 40IC, 40IAU e 40XPF do que nos grupos 30IC, 30IAU e 30XPF (p<0,05). A porcentagem de DR foi significativamente menor nos grupos em que se utilizou a IAU ou o XPF do que naqueles em que se utilizou a IC, independentemente do tamanho do preparo apical (p<0,05). A diferença entre os tamanhos de preparo apical 30 e 40 com relação aos DR foi maior quando se utilizou a IC (p<0,05). Concluiu-se que a instrumentação até um preparo apical de tamanho 40 resultou em menores porcentagens de PNI e DR do que até um preparo apical de tamanho 30. A utilização da IAU ou do XPF resultou em uma menor porcentagem de DR do que a utilização da IC.

Estudantes e Professores da Área da Saúde Conhecem o Programa Mais Médicos? / Familiarity with the More Doctors Program Among Health Sciences Professors and Students

RESUMO Diminuir as iniquidades na assistência à saúde continua sendo um grande desafio para países tanto pobres quanto ricos. No Brasil, o Programa Mais Médicos (PMM) foi instituído pelo governo federal em 2013 com a proposta de formar recursos humanos na área médica para o Sistema Único de Saúde (SUS), diminuir a carência de médicos, reduzir as desigualdades regionais na área da saúde e aprimorar a formação médica, ampliando a inserção do médico em formação nas áreas onde ele possa conhecer melhor a realidade da saúde da população. Considerando que os estudantes da área da saúde estão diretamente envolvidos com as propostas e os desfechos desse programa, o objetivo deste estudo foi avaliar o conhecimento e posicionamento não só dos estudantes, mas também de seus professores sobre o PMM. Um questionário foi aplicado a 106 alunos e 53 professores de uma faculdade privada na área da saúde (Medicina e Odontologia). A taxa de acerto das 25 questões sobre os objetivos e propostas de ação do PMM variou de 38,4% a 50,6%. A maioria dos docentes e alunos de Medicina referiu conhecer o PMM e reconhecia como proposta do programa diminuir a carência de médicos e melhorar a atuação nas políticas públicas de saúde. A proposta de aprimoramento da formação médica, oferta de cursos de Medicina e de vagas para residência médica, entretanto, era desconhecida por mais de 60% dos entrevistados. A contratação de médicos estrangeiros foi erroneamente considerada não só como um dos objetivos do programa, mas também como a ação proposta para atingir seus objetivos. Em conclusão, alunos e professores de instituições da área da saúde, embora sendo atores importantes na estratégia de atingir os objetivos propostos, conhecem pouco o PMM, particularmente nas ações relacionadas ao currículo das escolas e à residência médica. Estimular debates sobre o programa em escolas médicas pode modificar essa situação e favorecer o seu desfecho.

ABSTRACT Tackling unequal access to healthcare is a major challenge in both developed and developing countries. In Brazil, the Programa Mais Médicos (More Doctors Program – PMM) was created by the federal government in 2013 in order to reduce the shortage of doctors, address regional inequalities in healthcare access and improve medical education, expanding doctors’ training in fields where they can better understand the reality of the population’s health. Considering that students in the healthcare field are directly involved with the proposals and outcomes of this program, the objective of this study was to evaluate student knowledge and positioning and also that of their teachers on the PMM. A questionnaire was therefore administered to 106 students and 53 professors at a private medical and dentistry school. The hit rate for the 25 questions on the PMM’s objectives and proposals ranged from 38.4% to 50.6%.The majority recognized the PMM’s aim to reduce the shortage of doctors and improve public policies related to healthcare. The PMM’s aim to improve medical training, increasing the availability of medical courses and medical residencies, proved, however, to be unknown to over 60% of respondents. The hiring of foreign doctors was mistakenly considered not only to be the objective of the program, but also part of the initiatives designed to achieve the program objectives. The conclusion reached is that although university health sciences students and professors serve as important actors in the strategy for achieving the PMM’s goals, they have limited knowledge on the program, particularly in terms of the initiatives related to medical curricula and medical residencies. Discussion on the program could be introduced to medical courses in order to address this situation and improve the program’s outcomes.

Influência das células mioepiteliais neoplásicas benignas na invasão das células do melanoma: estudo in vitro / Influence of the benign neoplastic myoepithelial cells in the invasion of melanoma cells: an in vitro study

As células do microambiente tumoral apresentam papel fundamental no processo de invasão. Muitos estudos têm demonstrado, em tumores de mama, que as células mioepiteliais normais exercem efeitos parácrinos de supressão tumoral no epitélio glandular. As células mioepiteliais neoplásicas de tumores de glândula salivar também parecem atuar como supressoras naturais de tumor devido a algumas características, tais como expressão de altos níveis de inibidores de proteases. Desta maneira, o objetivo deste trabalho foi avaliar in vitro a influência das células mioepiteliais neoplásicas benignas de glândula salivar na invasão de células malignas. Para isso, células de melanoma (M2, ATCC) foram plaqueadas no compartimento superior das câmaras transwell com membrana de polietileno terefelato, com poros de 8µm de diâmetro, recoberto com Matrigel (BD). Após a aderência celular (4h), meio condicionado de células mioepiteliais provenientes de três adenomas pleomórficos de glândula salivar (AP3, AP4 e AP8) foi colocado no compartimento superior e meio DMEM (Sigma) no inferior do transwell. Após 48h, as células foram coradas em HE e o potencial de invasão e o número absoluto de células invadidas foram calculados em 1/3 da área da membrana (25 campos aleatórios, objetiva 20x), por meio de fotomicrografias em microscópio de luz. A análise de variância foi realizada aplicando o teste estatístico ANOVA seguido pelo teste de Tukey. Os resultados mostraram que a presença do meio condicionado de células mioepiteliais teve caráter supressor na invasão das células do melanoma. O índice de invasão foi estatisticamente significante no grupo AP8 (p<0,05) e os números absolutos de células invadidas, nos grupos AP3 e AP8 (p<0,05) quando comparados ao grupo controle. Desta maneira, pode-se concluir que, neste modelo de estudo, as células mioepiteliais neoplásicas benignas apresentaram efeito supressor na invasão das células do melanoma

Cells in the tumoral microenvironment have an important role in the invasion process. Many studies have shown, in breast tumors, that normal myoepithelial cells have paracrine effects as a tumor suppressor factor in the glandular epithelium. Myoepithelial cells from neoplastic salivary gland tumors also appear to act as natural suppressor tumor due to many characteristics, such as high levels expression of protease inhibitors. The aim of this study was an in vitro evaluation of the influence of neoplastic benign myoepithelial cells from salivary gland on the invasion of malignant cells. For this, melanoma cells (M2, ATCC) were plated on the upper compartment of transwell chambers with polyethylene terephthalate membrane with pore size diameter of 8 μm, coated with Matrigel (BD). After cell adherence (4 h), conditioned medium of myoepithelial cells from three salivary gland pleomorphic adenomas (AP3, AP4 and AP8) was added in the upper chamber and DMEM medium (Sigma) under the transwell. After 48 h, cells were stained with HE and the invasion potential and the absolute number of invaded cells were calculated in 1/3 part of the membrane area (25 random area, 20x objective), through photomicrographs by light microscopy. The analysis of variance was performed by ANOVA test followed by Tukey. The results showed that the conditioned medium of myoepithelial cells had a suppressor role in the melanoma cell invasion. The invasion potential was statistically significant in AP8 group (p <0.05) and also the absolute numbers of invaded cells in AP3 and AP8 groups (p <0.05) when compared with the control group. It can be concluded that in this model study, neoplastic benign myoepithelial cells showed suppressive effect on melanoma cells invasion