Abstract: Aldehyde dehydrogenase 1 (ALDH-1) is a marker of stem cells in a variety of diseases, but its role in individuals with chronic inflammatory periapical lesions remains unknown. The aim of this study was to investigate the presence of cells with a stem cell profile based on the immunoexpression of ALDH-1 in periapical granulomas (PGs) and radicular cysts (RCs). A total of 51 cases of periapical lesions (25 PGs and 26 RCs) were subjected to immunohistochemical study. The anti-ALDH-1 antibody was applied using the immunoperoxidase technique. An immunoexpression score (intensity vs. percentage of cells) was used, with the cases being classified as low expression (score: 0 to 4) and high expression (score: 6 to 9). The Chi-square test was used with a 5% level of significance. Immunoexpression of ALDH-1 was detected in all cases of PGs and RCs. In PG cases, the expression was diffuse in connective tissue cells, with most cases exhibiting high expression (n = 18; 69.2%), while in RC cases the expression revealed focal distribution in cells of the capsule and epithelial cells of the cystic lining, with most cases classified as low expression (n = 18; 72%). Significant differences in the expression scores of ALDH-1 were observed in PGs (p = 0.003). The variable expression of ALDH-1 suggests the presence of cells with stem cell profiles in PGs and RCs. These findings suggest that periapical tissues infiltrated by chronic inflammation can recruit important cells for the repair or evolution of periapical lesions.

ABSTRACT Objective. To analyze the incidence and mortality trends from COVID-19 in Brazil as well as in federation units and their capitals. Method. An ecological study was performed using COVID-19 incidence and mortality data covering the period from 25 February 2020 (first case recorded in Brazil) to 31 July 2021. Data were grouped by month for calculation of crude rates (by 100 000 population) and assessment of time trends in federation units and capitals. Significant changes in time trends were analyzed by joinpoint regression. Results. Two waves of new cases and deaths were identified. The highest incidence rates were recorded in the states of Amapá, Rio Grande do Norte, Rondônia, and Roraima. The states of Amazonas and Rondônia had the highest mortality rates. In general, incidence and mortality rates were worse in the second wave. In the first wave, the mean number of months until the onset of reduction in new cases was higher in capitals, whereas in the second wave the onset of reduction in new cases took longer in the federation units. The decline in mortality began earlier in capital cities in both waves. Conclusion. The regional differences detected underscore the notion that COVID-19 incidence and mortality are associated with political, geographic, cultural, social, and economic factors.

RESUMO Objetivo. Analisar as tendências de incidência e mortalidade por COVID-19 no Brasil, nas unidades da federação e nas capitais. Método. Realizou-se um estudo ecológico com dados de incidência e de mortalidade por COVID-19 referentes ao período de 25 de fevereiro de 2020 (primeiro caso notificado no Brasil) a 31 de julho de 2021. Os dados foram agrupados por mês para cálculo das taxas brutas (por 100 000 habitantes) e avaliação das tendências temporais das unidades da federação e de suas capitais. As modificações significativas nas tendências temporais foram analisadas pelo método de regressão por joinpoint. Resultados. Foram identificadas duas ondas de novos casos e óbitos. As unidades da federação com as maiores taxas de incidência foram Amapá, Rio Grande do Norte, Rondônia e Roraima; Amazonas e Rondônia tiveram as maiores taxas de mortalidade. Em geral, as taxas de incidência e mortalidade foram piores na segunda onda. Na primeira onda, a média de meses até o início de uma redução de casos novos foi maior nas capitais, enquanto na segunda onda, o início da redução demorou mais nos estados. Quanto aos óbitos, as capitais necessitaram de menos tempo para apresentar redução tanto na primeira quanto na segunda onda. Conclusão. A heterogeneidade regional detectada reforça a ideia de que a incidência e a mortalidade por COVID-19 estão associadas a fatores políticos, geográficos, culturais, sociais e econômicos.

RESUMEN Objetivo. Analizar las tendencias de la incidencia de COVID-19 y la mortalidad por esta enfermedad en Brasil (unidades federativas y capitales). Método. Se realizó un estudio ecológico con datos sobre incidencia de COVID-19 y la mortalidad por esta enfermedad en el período comprendido entre el 25 de febrero del 2020 (fecha del primer caso notificado en Brasil) y el 31 de julio del 2021. Los datos se agruparon por mes para calcular las tasas brutas (por 100 000 habitantes) y evaluar las tendencias temporales observadas en las unidades federativas y sus capitales. Las modificaciones significativas en las tendencias temporales se analizaron con el método de regresión de punto de inflexión (joinpoint). Resultados. Se identificaron dos olas de casos nuevos y muertes. Las unidades federativas con las mayores tasas de incidencia fueron Amapá, Rio Grande do Norte, Rondônia y Roraima; Amazonas y Rondônia tuvieron las mayores tasas de mortalidad. En general, la incidencia y la mortalidad fueron peores en la segunda ola. En la primera ola, el promedio de meses transcurridos hasta que empezó a reducirse el número de casos nuevos fue mayor en las capitales, mientras que, en la segunda ola, fue mayor en los estados. En ambas olas, el número de muertes se redujo en menos tiempo en las capitales. Conclusión. La heterogeneidad regional detectada refuerza la idea de que la incidencia de la COVID-19 y la mortalidad por esta enfermedad guardan relación con factores políticos, geográficos, culturales, sociales y económicos.

Abstract Matrix degradation is an important event in the progression, invasion and metastasis of malignant head and neck lesions. Imbalances, mutations and polymorphisms of MMPs and their inhibitors are observed in several cancer subtypes. The aim of this study was to evaluate the association of the MMP-7 gene promoter (181 A/G) and MMP-9 (-1562 C/T) polymorphisms in oral tongue squamous cell carcinoma (OTSCC). MMP-7 (rs11568818) and MMP-9 (rs3918242) single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 71 cases of OTSCC. Normal tissue specimens were obtained from 60 healthy volunteers to serve as the control. The MMP-7 G allele and MMP-9 T allele were more frequent in the OTSCC group than the control group, but only when these two SNPs were taken together was a significant association found with the nodal metastasis of OTSCC (p < 0.001). Based on our results, SNPs in the promoter region of MMP-7 and MMP-9 appear to be associated with greater risk of developing OTSCC, and with a higher propensity to form metastatic tumors. In this respect, molecular studies investigating polymorphisms may be useful in predicting tumor behavior.

Abstract Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) act in the proteolysis of basement membrane and extracellular matrix structures, facilitating tumor invasion. The purpose of this study was to evaluate the relationship between these proteins and clinicopathological parameters in squamous cell carcinoma of the oral tongue (SCCOT). Sixty cases of SCCOT were submitted to immunohistochemistry and analyzed semiquantitatively at the invasion front and in the tumor core. The results were associated with lymph node metastasis, clinical stage, locoregional recurrence, clinical outcome and histological grade of malignancy. A higher expression of uPA was observed in cases of tumors of high-grade versus low-grade malignancy (p = 0.010). Moreover, the cases with the worst pattern of invasion presented an overexpression of uPA (p = 0.011). The presence of locoregional recurrence was associated with uPAR (p = 0.039), and the expression of both biomarkers was much higher at the invasion front than in the tumor core (p < 0.001). The results suggest uPA and uPAR are involved in the progression and aggressiveness of SCCOT, mainly at the tumor-host interface.

Abstract The objective of this study was to evaluate the expression of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta (TGF-β1) in periapical lesion samples correlated with the intensity of the inflammatory infiltrate and thickness of the epithelial lining. Forty-five cases of periapical lesions (23 periapical granulomas and 22 radicular cysts) were subjected to morphological and immunohistochemical analyses using anti-MMP-9 and anti-TGF-β1 antibodies. The data were analyzed using the following tests: non-parametric Mann-Whitney, chi-square, Fisher’s exact test and Spearman’s correlation test (P<0.05). Analysis of inflammatory infiltrate revealed that 78% of periapical granulomas presented infiltrate grade III, in contrast with 32% of radicular cysts (P<0.001). Morphological evaluation of the epithelial thickness in radicular cysts revealed the presence of atrophic epithelium in 86% of the cysts. The immunostaining of MMP-9 was score 2 in 67% of the granulomas and 77% of the cysts. Both lesions were predominantly score 1 for TGF-β1. Significant differences were confirmed between the expression scores of TGF-β1 and MMP-9 in periapical granulomas (p = 0.004) and in radicular cysts (p < 0.001). Expression of TGF-β1 was different for periapical granulomas and radicular cysts. This immunoregulatory cytokine seems more representative in asymptomatic lesions. The extracellular matrix remodeling process dependent on MMP-9 seems to be similar for both periapical granulomas and radicular cysts. TGF-β1 and MMP-9 may play an important role in the maintenance of periapical lesions.

Tooth calcification begins during the intrauterine life and is related to the nutritional status of fetus. The purpose of this study was to evaluate the dental calcification status of 15 low-weight human fetuses aged from the 14th to 28th weeks of intrauterine life through radiographic analyses and von Kossa histochemical technique, which is specific to the detection of calcium and other mineral salts in tissues. After dissection of jaws, the mandibles were submitted to lateral and occlusal radiographies. Three mm thick slide sections of jaws samples were stained by conventional and von Kossa methods. As results, radiographic analysis did not exhibit any suggestive image of tooth mineralization, although rudiments of mandibular ossification could be noted. Hematoxilin and eosin sections revealed tooth germs in advanced phases of odontogenesis, but relative delay in tooth development was observed. The von Kossa staining did not show any positivity to the deposition of mineral salts in tooth germs from maxilla and mandible, supporting our findings related to the delay of dental development that was found in studied sample. Hence, we suggest that there is relation between the fetal low-weight and the calcification and maturation status of teeth.

La calcificación del diente comienza durante la vida intrauterina y se relaciona con el estado nutricional del feto. El propósito de este estudio fue evaluar el estado de calcificación dental de 15 fetos humanos de bajo peso entre las 14 y 28 semanas de vida intrauterina mediante análisis radiográficos y técnica histoquímica von Kossa, específica para la detección de calcio y otras sales minerales en los tejidos. Después de su disección, las mandíbulas fueron sometidas a radiografías laterales y oclusales. Secciones de 3 mm de espesor de las mandibulas fueron teñidas con la técnica Von Kossa. El análisis radiográfico no mostró ninguna imagen sugerente de mineralización dentaria, aunque rudimentos de la osificación mandibular podrían tenerse en cuenta. Las secciones de H-E revelaron la presencia de los gérmenes dentarios en las fases avanzadas de odontogénesis, pero con un retraso relativo en el desarrollo normal. La tinción de von Kossa no mostró positividad a la deposición de sales minerales en gérmenes dentarios, lo que apoya nuestros hallazgos relacionados con el retraso de desarrollo dental que se encontró en la muestra estudiada. Se sugiere que existe relación entre el bajo peso del feto y el estado de calcificación y maduración de los dientes.