Green tea extract rich in epigallocatechin gallate impairs alveolar bone loss in ovariectomized rats with experimental periodontal disease.

Periodontal disease and osteoporosis are characterized by bone resorption, and researchers have shown an association between these two diseases through increasing loss of systemic bone mass and triggering alveolar bone loss. Green tea is a common and easily accessible beverage, and evidences show that flavonoid epigallocatechin gallate (EGCG) could decrease bone loss in pathologies such as osteoporosis and periodontal disease. In order to verify its possible effects and apply them in the treatment and prevention of these diseases, this investigation aimed to evaluate the influence of green tea extract (GTE) on bone metabolism of ovariectomized rats after experimental periodontal disease (EPD) by histological, morphological and microtomographic parameters. Wistar female rats were divided into Sham, Sham + EPD, Sham + EPD + GTE, OVX, OVX + EPD and OVX + EPD + GTE groups. Immediately after surgery, gavage administration of 50 mg/kg of green tea extract (GTE) was performed for 60 days, with subsequent induction of periodontal disease by ligature 15 days before euthanasia. Mandible and femur samples were collected for histological, morphometric and microtomographic analysis. The results were analysed by means of statistical software with significance set at 5%. Histological and morphometric analysis showed a significant decrease in alveolar and femoral trabecular bone loss in groups that received GTE. Microtomographic results showed that trabecular thickness and bone surface density values in alveolar bone interradicular septum of the OVX + EPD + GTE groups were similar to the Sham group. The results obtained suggest that green tea extract may improve bone metabolism in osteoporotic rats with periodontal disease.

Lycopene influences osteoblast functional activity and prevents femur bone loss in female rats submitted to an experimental model of osteoporosis.

Antioxidant properties of several nutrients may influence bone metabolism, affording protection against damaging effects caused by oxidative stress. Thus, we hypothesized that lycopene may benefit bone tissue metabolism and functional activity of osteoblastic cells from bone marrow of osteoporotic female rats. Wistar rats were ovariectomized and paired with sham animals. In vitro evaluations were performed after 60 days of surgery, when cells were cultured in osteogenic medium and divided in control (C), ovariectomized (OVX) and ovariectomized + 1 µmol/L lycopene (OVXL) groups. Besides, in vivo studies were carried out to evaluate femur bone remodeling by histological and histomorphometric analyses after daily intake of 10 mg/kg of lycopene for 30 and 60 days after ovariectomy. Cell proliferation was significantly higher in OVX and OVXL groups after 10 days of culture. Alkaline phosphatase activity (ALP) was higher in OVXL group in later periods of cell culture, whereas its in situ detection was higher for this group in all experimental periods; nevertheless, mineralization did not show significant differences among the groups. There was a significant upregulation of genes Sp7, Runx2 and Bsp after 3 days and genes Runx2 and Bglap after 10 days from OVXL when compared to OVX. In vivo results demonstrated that daily intake of 10 mg/kg of lycopene for 60 days decreased bone loss in femur epiphysis in ovariectomized rats by maintaining trabecular bone similar to controls. Data obtained suggest that lycopene might benefit the functional activity of osteoblastic cells from ovariectomized rats, as well as avoid further bone resorption.

Oral microbiome mediated inflammation, a potential inductor of vascular diseases: a comprehensive review.

The dysbiosis of the oral microbiome and vascular translocation of the periodontopathic microorganism to peripheral blood can cause local and systemic extra-oral inflammation. Microorganisms associated with the subgingival biofilm are readily translocated to the peripheral circulation, generating bacteremia and endotoxemia, increasing the inflammation in the vascular endothelium and resulting in endothelial dysfunction. This review aimed to demonstrate how the dysbiosis of the oral microbiome and the translocation of oral pathogen-induced inflammation to peripheral blood may be linked to cardiovascular diseases (CVDs). The dysbiosis of the oral microbiome can regulate blood pressure and activate endothelial dysfunction. Similarly, the passage of periodontal microorganisms into the peripheral circulation and their virulence factors have been associated with a vascular compartment with a great capacity to activate endothelial cells, monocytes, macrophages, and plaquettes and increase interleukin and chemokine secretion, as well as oxidative stress. This inflammatory process is related to atherosclerosis, hypertension, thrombosis, and stroke. Therefore, oral diseases could be involved in CVDs via inflammation. The preclinic and clinical evidence suggests that periodontal disease increases the proinflammatory markers associated with endothelial dysfunction. Likewise, the evidence from clinical studies of periodontal treatment in the long term evidenced the reduction of these markers and improved overall health in patients with CVDs.

Osteoporosis Affects Functional Activity and Gene Expression of Osteoblastic Cells Derived from Rat Alveolar Bone.

Recent studies suggest that osteoporosis, in addition to the damage caused in long bones, may cause deterioration in the jaws, especially in alveolar bone sites, with effects in the progress of periodontal disease as well as in bone healing. The aim of this study was to evaluate the effect of osteoporosis in the metabolism of rat alveolar bone osteoblasts. There were used 10 female rats divided in two experimental groups (Sham and OVX), which were ovariectomized and after 8 weeks euthanized to collect mandibular bone samples in order to isolate osteoblastic cells. The cells were cultured in 24-well plates to perform the in vitro experiments. After 7, 10 and 14 days, there were evaluated cell proliferation by MTT assay, in situ detection of alkaline phosphatase (ALP) as well as mineralized nodules and expression of genes associated to bone remodeling. Results showed that at 7, 10 and 14 days cell proliferation was lower for OVX group. In situ detection of ALP was higher at 7 days and lower at 10 and 14 days in OVX group. At 17 and 21 days, OVX group had a significative decrease of mineralization nodules. There was a downregulation in the expression of Alp, Bglap and Runx2 genes and an upregulation of Opg in OVX group, whereas Opn and Rankl modulation was similar between the evaluated groups. Our results suggest that osteoporosis has a deleterious effect on alveolar bone cells from ovariectomized rats, which might affect the treatment of diseases associated to the jaw bones.

Cell therapy stimulates bone neoformation in calvaria defects in rats subjected to local irradiation.

BACKGROUND: The purpose of the study was to analyze the effect of cell therapy on the repair process in calvaria defects in rats subjected to irradiation. METHODS: Bone marrow mesenchymal cells were characterized for osteoblastic phenotype. Calvariae of male Wistar rats were irradiated (20 Gy) and, after 4 weeks, osteoblastic cells were placed in surgically created defects in irradiated (IRC) and control animals (CC), paired with untreated irradiated (IR) and control (C) animals. After 30 days, histological and microtomographic evaluation was performed to establish significant (P < 0.05) differences among the groups. RESULTS: Higher alkaline phosphatase detection and activity, along with an increase in mineralized nodules, in the IRC, C and CC groups compared to the IR group, confirmed an osteoblastic phenotype. Histology showed impaired bone neoformation following irradiation, affecting bone marrow composition. Cell therapy in the IRC group improved bone neoformation compared to the IR group. Microtomography revealed increased bone volume, bone surface and trabecular number in IRC group compared to the IR group. CONCLUSION: Cell therapy may improve bone neoformation in defects created after irradiation.

Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model.

Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. OBJECTIVE: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. MATERIAL AND METHODS: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. RESULTS: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. CONCLUSION: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Colombia y Uruguay ante la COVID-19: datos epidemiológicos, medidas generales y en la práctica odontológica / Colombia and Uruguay in the face of COVID-19: epidemiological data, general and dental practice measures

Objetivo: analizar los datos epidemiológicos y las medidas generales en la práctica odontológica tomadas por Colombia y Uruguay durante la pandemia por la COVID-19. Métodos: este trabajo es una revisión de la literatura. Se consultaron las bases de datos "PubMed", "Scielo" y el motor de búsqueda "Google Scholar". También se consultaron bases de datos de libre acceso como google, our world in data y las páginas oficiales de la Organización Mundial de la Salud, el Ministerio de Salud de Colombia, el Instituto Nacional de Salud y el Ministerio de Salud Pública de Uruguay. Se realizó un análisis descriptivo del comportamiento epidemiológico y de las medidas tomadas en la práctica odontológica en los dos países. Resultados: en Colombia, a diario, se presentan más de 3.000 casos nuevos y más de 100 muertes. Lo contrario ocurre en Uruguay, que ha logrado disminuir las tasas de contagio y de muertes, presentando menos de 10 casos y ninguna muerte diaria. Los profesionales de la salud han incrementado su lucha; los odontólogos se encuentran expuestos por su proximidad al momento de la atención, en el contacto con saliva, sangre y la generación de aerosoles, por lo que han modificado los protocolos de bioseguridad buscando prevenir los contagios asociados a la prestación de servicio. Conclusiones: Uruguay ha tenido un comportamiento ejemplar ante la pandemia; en Colombia los resultados son preocupantes dado el crecimiento exponencial. En ambos países la práctica odontológica se ha visto afectada y se han implementado nuevos protocolos para proteger a profesionales y pacientes.

Objective: Analyze the epidemiological data, general and dental practice measures taken by Colombia and Uruguay in the face of the COVID-19 pandemic. Methods: This study is a review. We search in the databases "PubMed", "Scielo" and in the search engine "Google Scholar". Also, were consulted the free databases like google, our world in data and the official pages of the World Health Organization, Ministry of Health of Colombia, The National institute of health and the Ministry of public Health of Uruguay. A descriptive analysis of the epidemiological behavior and the measures taken of dental practice in both countries was done. Results: Colombia had more than 3,000 new cases and more than 100 deaths daily. The opposite occurs in Uruguay, which has managed to decrease the infection and death rates, presenting less than 10 cases and no daily deaths. The struggles experienced by health professionals has increased, dentists are exposed, by their proximity at the time of care, to contact with saliva, blood and the generation of aerosols, therefore, they have modified the biosafety protocols, seeking to prevent infections associated with the practice. Conclusions: Uruguay has an exemplary behavior; in Colombia these results are worrying with an exponential growth. In both countries, dental practice has been affected and new protocols have been implemented that seek to protect the professionals and patients.

Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model

Abstract Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. Objective: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. Material and Methods: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. Results: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. Conclusion: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Cyclooxygenase biology in renal function - literature review / Biología de la ciclooxigenasa en la función renal - Revisión de la literatura

Abstract The cyclooxygenase (COX) exists in two main isoforms, COX-1 and COX-2, which are present in the renal system to ensure its homeostasis. However, in different clinical situations, these enzymes can play a physiologic role in maintaining the integrity of this organ, and also be associated with the worsening of tissue injuries/damage. In this sense, an explanation of the true biological function of the isoforms of COX enables a better understanding of the physiology and pathology of the kidney, as well as a better understanding of the consequences of its inhibition by the use of drugs. This review aimed to study the biological role of the COX enzyme in the renal system in different clinical situations.

Resumen La ciclooxigenasa existe en dos isoformas principales: COX-1 y COX-2, estas se encuentran presentes en el sistema renal como parte de su homeostasis. Sin embargo, en algunas situaciones clínicas, las dos enzimas pueden desempeñar un papel en el mantenimiento de la integridad de este órgano, y en otras pueden estar asociadas a la evolución de daños y lesiones en los tejidos. En este sentido, el conocimiento de la verdadera función biológica de las isoformas de la COX permite una mejor comprensión de la fisiología y patología del riñón, así como una mejor comprensión de las consecuencias de su inhibición por el uso de medicamentos. El objetivo de esta revisión es estudiar la función biológica de la enzima COX en el sistema renal en diferentes situaciones clínicas.