High-intensity infrasound effects on glucose metabolism in rats.

Recent focus has been given on the effects of high-intensity infrasound (HII) exposure, and whether it induces changes in pancreatic morphology and glucose metabolism is still unknown. As such, we have studied the impact of HII exposure on glucose tolerance, insulin sensitivity, pancreatic islet morphology, muscle GLUT4 and plasma insulin and corticosterone levels. Normal and glucose intolerant wild-type Wistar rats were randomly divided in two groups: one group not exposed to HII and the other continuously exposed to HII. Animals were sacrificed at three timepoints of exposure (1, 6 or 12 weeks). An intraperitoneal glucose tolerance test was performed, blood samples were collected and the pancreas and the quadriceps femoris muscle were excised. Circulating insulin and corticosterone levels were determined and pancreatic and muscular tissue were routinely processed for histochemistry and immunohistochemistry with an anti-GLUT4 antibody. Animals exposed to HII had higher corticosterone levels than animals not exposed. No differences were found on insulin concerning HII exposure or glucose intolerance. Glucose intolerant animals had pancreatic islet fibrosis and no differences were found in GLUT4 ratio concerning HII exposure. In conclusion, we found that continuous exposure to HII increases stress hormone levels without inducing glucose intolerance in rats.

Autogenous Mineralized Dentin versus Xenograft granules in Ridge Preservation for Delayed Implantation in Post-extraction Sites: A Randomized controlled clinical trial with an 18 months follow-up.

OBJECTIVES: To test primary stability of delayed implants placed in post-extraction ridges preserved with autogenous mineralized dentin matrix (MDM) versus xenograft granules. Clinical, histological and pain experience outcomes were further assessed. MATERIAL AND METHODS: From March 2018 to July 2020, patients requiring ridge preservation in preparation for delayed implant placement in post-extraction sites were included. Participants were randomly allocated to either the test (MDM) or control group (xenograft granules) prior to ridge preservation. Visual analogue scale and analgesic consumption were measured every day for a week. Six months after preservation, trephine cores were harvested for histomorphometry prior to implant placement. Implants were then placed, and implant stability was measured immediately as well as two months after placement. Marginal bone loss and presence of mucositis/peri-implantitis were registered up to 18 months after prosthetic loading. RESULTS: Fifty-two patients (66 implants) completed the study. MDM and xenograft groups presented similar primary (77.1 ± 6.9 versus. 77.0 versus. 5.9) and secondary (81.8 ± 5.1 versus. 80.1 ± 3.8) implant stabilities. The percentage of newly formed bone in MDM (47.3%) was significantly higher than xenograft (34.9%) (p < .001), and the proportion of residual graft was significantly lower (12.2% in MDM and 22.1% in xenograft) (p < .001). No significant differences were found as far as clinical, radiographic and patient-related outcomes. CONCLUSIONS: Implants placed in sites preserved with MDM had similar primary stability in comparison to xenograft granules. MDM showed a significantly higher quantity of newly formed bone and lower amount of residual graft in histomorphometry results and equal clinical and patient-related outcomes.

Retrospective study of the concordance between clinical and histopathological diagnosis in oral pathology / Estudio retrospectivo de la concordancia entre diagnóstico clínico e histopatológico en patología oral

Objectives: Evaluate the agreement between the clinical and histopathological diagnosis of oral lesions in patients submitted to biopsies. Identify the most frequent oral lesions and their correlation with age, gender, and anatomical location. Methods: A retrospective study of 368 pathological examinations collected between 2008 and 2018, corresponding to biopsies performed at the Clínica Universitária Egas Moniz. A detailed analysis of the histopathological reports attached to the patients' files was made and the variables gender, age, anatomical site, clinical diagnosis, and histopathological diagnosis was evaluated. Results: The most affected gender was female (55%); the most common age group was 61-70 years old; The most biopsied anatomical location was the gum (23.9%); the five most common pathological entities were fibroma(26.4%),root cyst(8.7%),oral lichen planus(7.6%), hemangioma (6.3%) and oral leukoplakia (6.0%). On agreement, 74.5% of the cases were concordant and 25.5% discordant. The most concordant lesions were Radicular Cyst (90.6%), Traumatic Injury (87.5%), Hemangioma (82.6%), Fibroma (82.5%) and Mucocele (82.5%). Conclusion: this study proves a significant level of agreement between clinical and histopathological diagnosis in this particular area, consistently obtained in a ten years period of time.

Objetivos: Evaluar el nivel de acuerdo entre el diagnóstico clínico e histopatológico de lesiones orales en pacientes sometidos a biopsias. Identificar las lesiones orales más frecuentes y su correlación con la edad, el sexo y la ubicación anatómica. Métodos: Estudio retrospectivo de 368 exámenes patológicos recogidos entre 2008 y 2018, correspondientes a biopsias realizadas en la Clínica Universitária Egas Moniz. Se realizó un análisis detallado de los informes histopatológicos adjuntos a los archivos de los pacientes y se evaluaron las variables de género, edad, sitio anatómico, diagnóstico clínico y diagnóstico histopatológico. Resultados: El género más afectado fue femenino (55%); el grupo de edad más común fue de 61-70 años; La ubicación anatómica más biopsiada fue la encía (23,9%); las cinco entidades patológicas más comunes fueron fibroma (26,4%), quiste radicular (8,7%), liquen plano oral (7,6%), hemangioma (6,3%) y leucoplasia oral (6,0%). Según el grado de acuerdo, el 74,5% de los casos fueron concordantes y el 25,5% discordantes. Las lesiones más concordantes fueron Quiste Radicular (90,6%), Lesión Traumática (87,5%), Hemangioma (82,6%), Fibroma (82,5%) y Mucocele (82,5%). Conclusión: este estudio demuestra un nivel significativo de acuerdo entre el diagnóstico clínico e histopatológico en esta área en particular, obtenido consistentemente en un período de diez años de tiempo

Atrial fibrosis and decreased connexin 43 in rat hearts after exposure to high-intensity infrasound.

BACKGROUND: Noise is an important environmental risk factor. Industrial environments are rich in high-intensity infrasound (hi-IFS), which we have found to induce myocardial and coronary perivascular fibrosis in rats. The effects of exposure to IFS on the ventricles have been studied, but not on the atria. We hypothesized that rats exposed to hi-IFS develop atrial remodeling involving fibrosis and connexin 43, which we sought to evaluate. MATERIAL AND METHODS: Seventy-two Wistar rats, half exposed to hi-IFS (120 dB, <20 Hz) during a maximum period of 12 weeks and half age-matched controls, were studied. Atrial fibrosis was analyzed by Chromotrope-aniline blue staining. The immunohistochemical evaluation of Cx43 was performed using the polyclonal antibody connexin-43 m diluted 1:1000 at 4 °C overnight. Digitized images were obtained with an optical microscope using 400× magnifications. The measurements were performed using image J software. A two-way ANOVA model was used to compare the groups. RESULTS: The mean values of the ratio "atrial fibrosis / cardiomyocytes" increased to a maximum of 0.1095 ± 0,04 and 0.5408 ± 0,01, and of the ratio "CX43 / cardiomyocytes" decreased to 0.0834 ± 0,03 and 0.0966 ± 0,03, respectively in IFS-exposed rats and controls. IFS-exposed rats exhibited a significantly higher ratio of fibrosis (p < .001) and lower ratio of Cx43 (p = .009). CONCLUSION: High-intensity infrasound exposure leads to an increase in atrial interstitial fibrosis and a decrease in connexin 43 in rat hearts. This finding reinforces the need for further experimental and clinical studies concerning the effects of exposure to infrasound.

Extruded Bioreactor Perfusion Culture Supports the Chondrogenic Differentiation of Human Mesenchymal Stem/Stromal Cells in 3D Porous Poly(ɛ-Caprolactone) Scaffolds.

Novel bioengineering strategies for the ex vivo fabrication of native-like tissue-engineered cartilage are crucial for the translation of these approaches to clinically manage highly prevalent and debilitating joint diseases. Bioreactors that provide different biophysical stimuli have been used in tissue engineering approaches aimed at enhancing the quality of the cartilage tissue generated. However, such systems are often highly complex, expensive, and not very versatile. In the current study, a novel, cost-effective, and customizable perfusion bioreactor totally fabricated by additive manufacturing (AM) is proposed for the study of the effect of fluid flow on the chondrogenic differentiation of human bone-marrow mesenchymal stem/stromal cells (hBMSCs) in 3D porous poly(ɛ-caprolactone) (PCL) scaffolds. hBMSCs are first seeded and grown on PCL scaffolds and hBMSC-PCL constructs are then transferred to 3D-extruded bioreactors for continuous perfusion culture under chondrogenic inductive conditions. Perfused constructs show similar cell metabolic activity and significantly higher sulfated glycosaminoglycan production (≈1.8-fold) in comparison to their non-perfused counterparts. Importantly, perfusion bioreactor culture significantly promoted the expression of chondrogenic marker genes while downregulating hypertrophy. This work highlights the potential of customizable AM platforms for the development of novel personalized repair strategies and more reliable in vitro models with a wide range of applications.

Multiple Complex Odontomas of the Mandible: A Rare Case Report and Literature Review.

A 53-year-old female appeared with pain in the right mandible ramus, for the past 9 months, after tooth extraction. Clinical and radiological examination using conventional and advanced computerized tomography diagnostic imaging led to a provisional diagnosis of multiple complex odontomas. Complete conservative excision of the lesion was performed. The clinical diagnosis was confirmed histopathologically. Postoperative period was uneventful with no evidence of recurrence. According to an extensive literature review, this report describes the oldest patient ever diagnosed with multiple odontomas in the literature.

Infrasound induces coronary perivascular fibrosis in rats.

BACKGROUND: Chronic exposure to industrial noise is known to affect biological systems, namely, by inducing fibrosis in the absence of inflammatory cells. In rat hearts exposed to this environmental hazard, we have previously found myocardial and perivascular fibrosis. The acoustic spectrum of industrial environments is particularly rich in high-intensity infrasound (<20 Hz), whose effects on the heart are unknown. We evaluated the morphological changes induced by IFS in rat coronaries in the presence and absence of dexamethasone. METHODS: Adult Wistar rats were divided into three groups: group A (GA)-IFS (<20 Hz, 120 dB)-exposed rats for 28 days treated with dexamethasone; group B (GB)-IFS-exposed rats; group C (GC)-age-matched controls. The midventricle was prepared for observation with an optical microscope using 100× magnification. Thirty-one arterial vessels were selected (GA 8, GB 10, GC 13). The vessel caliber, thickness of the wall, and perivascular dimensions were quantified using image J software. Mann-Whitney and Kruskal-Wallis tests were used to compare the groups for lumen-to-vessel wall (L/W) and vessel wall-to-perivascular tissue (W/P) ratios. RESULTS: IFS-exposed rats exhibited a prominent perivascular tissue. The median L/W and median W/P ratios were 0.54 and 0.48, 0.66 and 0.49, and 0.71 and 0.68, respectively, in GA, GB, and GC. The W/P ratio was significantly higher in GC compared with IFS-exposed animals (P=.001). The difference was significant between GC and GB (P=.008) but not between GC and GA. CONCLUSION: IFS induces coronary perivascular fibrosis that differs under treatment with corticosteroid.

In situ Multispecies Colonization of An Acrylic Resin: Comparison to Oral Microbiome and Potential for Inflammatory Response.

BACKGROUND: Conventional acrylic resin is prone to microbial colonization and may cause inflammatory and allergic response. AIMS: This study aims to research the initial microbial adhesion in situ and tissue response to an acrylic resin used in prosthodontics. MATERIALS AND METHODS: Disks of a commercial acrylic resin were prepared and included on the surface of individual intraoral splints fabricated for 50 participants. The splints were used for 4 h, under clinical conditions. Beforehand, each participant was swabbed to provide a control for microbiological comparison. A cytological control sample was also taken from the palate. After the time elapsed, each splint was removed and growth of anaerobes, aerobes, Pseudomonas, oral streptococci, staphylococci, yeasts, and Streptococcus mutans was determined by plate counts and compared to the oral microbiome. A cytological sample was taken from the contact zone, stained using the Papanicolaou technique, analyzed in light microscopy, and classified accordingly. Means and standard deviations were calculated, and a nonparametric Wilcoxon test was employed to compare experimental groups. The significance level was set at 0.05 (95% confidence interval, and statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 20.0. RESULTS: Nuclear-cytoplasm ratio increase was found in 84% of the smears retrieved from the contact zone. Over 60% showed nuclear alterations. With exception to yeasts and Pseudomonas, all microbial groups colonized the resin. No statistically significant differences were found between the oral microbiome and the acrylic resin's colonization except regarding yeasts (P > 0.05). CONCLUSIONS: Cellular alterations were found but a diagnosis of inflammation is inconclusive. Microbial adhesion to the acrylic resin was substantial, with multiple species adhering.

Human ex vivo dentin-pulp complex preservation in a full crown model.

OBJECTIVES: Currently, there is lack of human in vitro full tooth models that hold the odontoblast layer with pulp tissue in their native environment. The appearance of new in vitro and in vivo models has provided new understanding of the potential of tissue engineering in dental pulp regeneration. However, the development of new in vitro full tooth models will allow us to get closer to in vivo conditions. Thus, the aim of this study is to preserve a living dentin-pulp complex, in a novel in vitro full crown model, after tooth extraction. METHODS: Twenty intact third molars, after preparation, were divided into four groups, with five samples each. We placed the negative control samples (C) in saline, and the tested groups were placed (T) in supplemented DMEM, at two different times: 1 and 7 days. The specimens were processed for light microscopy observation. RESULTS: Contrary to C-groups, T-groups showed a functional dentin-pulp complex. The treated dentin-pulp complex presents normal histological appearance. CONCLUSIONS: This study showed that it is possible to preserve a living dentin-pulp complex after tooth extraction during 7 days.

Histomorphometric evaluation of the small coronary arteries in rats exposed to industrial noise.

UNLABELLED: Morphological changes induced by industrial noise (IN) have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. OBJECTIVE: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. METHODS: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls) were selected. The mean lumen-to-vessel wall (L/W) and mean vessel wall-to-perivascular tissue (W/P) ratios were calculated using image J software. RESULTS: There were no differences between exposed and control animals in their L/W ratios (p=0.687) and time variations in this ratio were non-significant (p=0.110). In contrast, exposed animals showed lower W/P ratios than control animals (p<0.001), with significant time variations (p=0.004). CONCLUSIONS: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis.

Industrial noise and tooth wear - experimental study.

UNLABELLED: Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear. The effects of continuous exposure to industrial noise, a "stressor" agent, cannot be ignored and its effects on the teeth must be evaluated. AIMS: The aim of this study was to ascertain the effects of industrial noise on dental wear over time, by identifying and quantifying crown area loss. MATERIAL AND METHODS: 39 Wistar rats were used. Thirty rats were divided in 3 experimental groups of 10 animals each. Animals were exposed to industrial noise, rich in LFN components, for 1, 4 and 7 months, with an average weekly exposure of 40 hours (8h/day, 5 days/week with the weekends in silence). The remaining 9 animals were kept in silence. The areas of the three main cusps of the molars were measured under light microscopy. STATISTICAL ANALYSIS USED: A two-way ANOVA model was applied at significance level of 5%. RESULTS: The average area of the molar cusps was significantly different between exposed and non-exposed animals. The most remarkable differences occurred between month 1 and 4. The total crown loss from month 1 to month 7 was 17.3% in the control group, and 46.5% in the exposed group, and the differences between these variations were significant (p<0.001). CONCLUSIONS: Our data suggest that industrial noise is an important factor in the pathogenesis of tooth wear.

Effects of low-frequency noise on cardiac collagen and cardiomyocyte ultrastructure: an immunohistochemical and electron microscopy study.

INTRODUCTION: Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications. OBJECTIVES: The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN. METHODS: Two groups of rats were considered: A LFN-exposed group with 8 rats continuously submitted to LFN during 3 months and a control group with 8 rats. The hearts were sectioned and the mid-ventricular fragment was selected. After immunohistochemical evaluation, quantification of the collagens and muscle were performed using the image J software in the left ventricle, interventricular septum and right ventricle and the collagen I/muscle and collagen III/muscle ratios were calculated. Transmission electron microscopy (TEM) was used to analyze mid-ventricular samples taken from each group. RESULTS: The collagen I/muscle and collagen III/muscle ratios increased in totum respectively 80% (p<0.001) and 57.4% (p<0.05) in LFN-exposed rats. TEM showed interstitial collagen deposits and changes in mitochondria and intercalated discs of the cardiomyocytes in LFN-exposed animals. CONCLUSIONS: LFN increases collagen I and III in the extracellular matrix and induces ultrastructural alterations in the cardiomyocytes. These new morphological data open new and promising paths for further experimental and clinical research regarding the cardiac effects of low-frequency noise.

Immunohistochemical evaluation of cardiac connexin43 in rats exposed to low-frequency noise.

INTRODUCTION: Low-frequency noise (LFN) leads to an abnormal proliferation of collagen and development of tissue fibrosis. It has been shown that myocardial fibrosis in association with gap junction remodeling occurs in several cardiac diseases and can be implicated in the development of ventricular tachyarrhythmias. We previously reported a strong development of myocardial fibrosis induced by LFN in rats but it is not known whether LFN induces any modification on cardiac connexin43 (Cx43). OBJECTIVES: The aim of this study was to evaluate modifications on cardiac Cx43 induced by LFN in Wistar rats. METHODS: Two groups of rats were considered: A LFN-exposed group with 10 rats submitted continuously to LFN during 3 months and a control group with 8 rats. The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. The immunohistochemical evaluation of Cx43 was performed using the polyclonal antibody connexin-43m diluted 1:1000 overnight at 4°C. Quantifications of Cx43 and muscle were performed with the image J software and the ratio Cx43/muscle was analyzed in the left ventricle, interventricular septum and right ventricle. RESULTS: The ratio Cx43/muscle was significantly reduced in LFN-exposed rats (p=0.001). The mean value decreased 46.2%, 22.2% and 55.6% respectively in the left ventricle (p=0.008), interventricular septum (p=0.301) and right ventricle (p=0.004). CONCLUSIONS: LFN induces modifications on cardiac Cx43 in rats. The Cx43 reduction observed in our study suggests that LFN may induce an arrhythmogenic substrate and opens a new investigational area concerning the effects of LFN on the heart.

Myocardial fibrosis in rats exposed to low frequency noise.

UNLABELLED: Low frequency noise (LFN) characterized by large pressure amplitude (> or =90 dB SPL) and low frequency bands (< or =500 Hz) can lead to structural and ultrastructural modifications in the extracellular matrix of several tissues, with an abnormal proliferation of collagen and development of fibrosis. It is not known whether LFN induces similar structural alterations in the ventricular myocardium of rats. OBJECTIVE: The aim of this study was to evaluate and measure the myocardial fibrosis induced by LFN. METHODS: Two groups of rats were considered: group A with 26 rats continuously exposed to LFN during a period of 3 months; group B with 20 control rats.The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. Chromotrope-aniline blue (CAB) staining was used for histological observation. The measurement of fibrosis was performed using the computer image analysis Image J software. RESULTS: Histological observation with CAB staining showed the presence of collagen deposition between the cardiomyocytes. Fibrosis increased 97.5%, 81.5% and 83.7%, respectively, in the left ventricle, interventricular septum and right ventricle, in exposed rats (P <0.001).The ratio fibrosis/muscle in left ventricle, interventricular septum and right ventricle was significantly higher in LFN exposed rats (P< 0.001). CONCLUSIONS: Our study demonstrates a significant myocardial fibrosis induced by low frequency noise in rats. Our results reinforce the need for further experimental and clinical investigations concerning the effects of low frequency noise on the heart.

Osteotomy at low-speed drilling without irrigation versus high-speed drilling with irrigation: an experimental study.

INTRODUCTION: Excessively traumatic surgery can adversely affect the maturation of bone tissue and consequently diminish the predictability of osseointegration so the mechanical and thermal damage should be minimized during surgical procedure. The purpose of this study is to evaluate immediate histological alterations in rabbit tibias, produced by low speed drilling (50 rpm) without irrigation and conventional drilling (800 rpm) under profuse irrigation. MATERIAL AND METHODS: Thirty-six implant osteotomies were created in the tibias of 6 White female rabbits. Drilling began with a 1.5 mm round bur, followed by 2.0 mm, 2.5 mm and 3.5 mm helical drills. The posterior tibial cortex was evaluated as the positive control, and it was preserved during the surgical procedure. The receptor beds were collected for histological analysis. RESULTS: All defects showed regular edges. Hematoxylin eosin (HE) sections showed that both techniques preserved the bone structure and the presence of living cells. No histological differences between the two surgical drilling techniques were found. CONCLUSIONS: Based on our results, we can conclude that the effects of implant site preparation on bone by low speed drilling (50 rpm) without irrigation and conventional drilling (800 rpm) under abundant irrigation are similar. Both surgical drilling techniques preserve bone-cell viability and the clinician can decide which drilling technique to use, based on other criteria.

Introdução: A cirurgia traumática pode afetar a maturação do tecido ósseo e, diminuir a previsibilidade de osteointegração, pelo que a lesão mecânica e térmica deve ser minimizada. O objectivo deste estudo foi avaliar as alterações histológicas imediatas provocadas pela osteotomia a 50 rpm sem irrigação e a 800 rpm com irrigação, no osso do coelho.Material e Métodos: Foram efectuadas 36 perfurações (18 com cada técnica) nas tíbias de seis coelhos adultos. A sequência debrocas utilizada foi: uma broca esférica com 1,5 mm de diâmetro, uma broca piloto com 2,0 mm de diâmetro, e uma broca com 3,5 mm de diâmetro. A cortical posterior das tíbias foi preservada, constituindo o osso de controlo. Procedeu-se à recolha das tíbias com os defeitos a analisar, para observação com microscópio óptico e análise qualitativa.Resultados: Os defeitos ósseos apresentaram bordos regulares. Observou-se tecido ósseo viável, vascularizado e com presença de osteócitos junto aos defeitos. A estrutura haversiana e lamelar do tecido encontrou-se mantida, bem como a rede vascular. A matriz extracelular não apresentou alterações. Os resultados indicam não haver diferenças histológicas entre as osteotomias a 800 rpm com irrigação e a 50 rpm sem irrigação.Conclusão: O nosso estudo sugere que as alterações no tecido ósseo provocadas pela osteotomia a 50 rpm sem irrigação e a 800 rpm com irrigação são semelhantes, e que ambas as técnicas mantêm o tecido ósseo viável para a colocação de implantes e respectiva osteointegração, cabendo ao clínico a escolha, em função de outras variáveis.