Salivary biomarkers and neuropsychological outcomes: A non-invasive approach to investigate pollutants-associated neurotoxicity and its effects on cognition in vulnerable populations.

The occurrence of neurotoxicity caused by xenobiotics such as pesticides (dichlorodiphenyltrichloroethane, organophosphates, pyrethroids, etc.) or metals (mercury, lead, aluminum, arsenic, etc.) is a growing concern around the world, particularly in vulnerable populations with difficulties on both detection and symptoms treatment, due to low economic status, remote access, poor infrastructure, and low educational level, among others features. Despite the numerous molecular markers and questionnaires/clinical evaluations, studying neurotoxicity and its effects on cognition in these populations faces problems with samples collection and processing, and information accuracy. Assessing cognitive changes caused by neurotoxicity, especially those that are subtle in the initial stages, is fundamentally challenging. Finding accurate, non-invasive, and low-cost strategies to detect the first signals of brain injury has the potential to support an accelerated development of the research with these populations. Saliva emerges as an ideal pool of biomarkers (with interleukins and neural damage-related proteins, among others) and potential alternative diagnostic fluid to molecularly investigate neurotoxicity. As a source of numerous neurological biomarkers, saliva has several advantages compared to blood, such as easier storage, requires less manipulation, and the procedure is cheaper, safer and well accepted by patients compared with drawing blood. Regarding cognitive dysfunction, neuropsychological batteries represent, with their friendly interface, a feasible and accurate method to evaluate the eventual cognitive deficits associated with neurotoxicity in people from diverse cultural and educational backgrounds. The association of these two tools, saliva and neuropsychological batteries, to cover the molecular and cognitive aspects of neurotoxicity in vulnerable populations, could potentially increase the prevalence of early intervention and successful treatment.

Dental biofilm of symptomatic COVID-19 patients harbours SARS-CoV-2.

AIMS: SARS-CoV-2 RNA has been recovered from different sites in the human body, including the mouth. The present study aimed to investigate the presence of SARS-CoV-2 RNA in the dental biofilm of symptomatic patients who tested positive in nasopharyngeal and oropharyngeal (NASO/ORO) samples. MATERIALS & METHODS: An observational clinical study of individuals with flu-like symptoms was conducted between July and September 2020. Dental biofilm (BIO) samples were collected and analysed using real-time quantitative polymerase chain reaction (RT-qPCR) to determine the virus's presence. RESULTS: Seventy participants (40 ± 9.8 years of age, 71.4% female) tested positive for SARS-CoV-2 RNA in NASO/ORO samples and were included in the study. Among them, 13 tested positive in BIO samples (18.6%; 95% CI: [9.5, 27.7]). The median and interquartile range of cycle quantification (Cq) for NASO/ORO and BIO samples were 15.9 [6.9] and 35.9 [4.0] (p = .001), respectively. BIO-positive participants showed a higher virus load in NASO/ORO samples (p = .012) than those testing negative (Cq = 20.4 [6.1]). CONCLUSIONS: Dental biofilms from symptomatic COVID-19 patients harbour SARS-CoV-2 RNA and might be a potential reservoir with an essential role in COVID-19 transmission.

Antimicrobial effect and cytotoxic activity of vinegar-hydrogen peroxide mixture: A possible alternative for denture disinfection.

STATEMENT OF PROBLEM: Soaking dentures in vinegar or hydrogen peroxide does not seem to remove the microorganisms involved with prosthetic stomatitis efficiently. A mixture of these 2 substances may be effective, but studies are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the antimicrobial effect and cytotoxic activity of vinegar-hydrogen peroxide mixtures against Candida albicans and Staphylococcus aureus. MATERIAL AND METHODS: For antimicrobial tests, planktonic cells and biofilms of C. albicans and S. aureus cultured on acrylic resin disks were exposed to 0.5% sodium hypochlorite; 0.2% peracetic acid; vinegar-hydrogen peroxide mixtures at concentration ratios 1:1, 1:3, and 3:1; vinegar-water mixtures at concentration ratios 1:1, 1:3, and 3:1; and hydrogen peroxide-water mixtures at concentration ratios 1:1, 1:3, and 3:1. Antimicrobial activity was evaluated by counting viable colony-forming units after disinfection. For cytotoxicity tests, the 1:1 vinegar-hydrogen peroxide mixture was serially diluted (10-1 to 10-4) and allowed to be in direct contact with HaCaT keratinocytes for 24 hours. Cytotoxicity was quantitatively and qualitatively determined by counting the number of viable cells and analyzing morphological cell changes. RESULTS: All vinegar-hydrogen peroxide mixtures, sodium hypochlorite, and peracetic acid efficiently eliminated C. albicans and S. aureus (P<.05), whereas vinegar and hydrogen peroxide solutions used separately were not as efficient as the experimental mixtures. The 10-3 and 10-4 dilutions of vinegar-hydrogen peroxide solutions were considered noncytotoxic, whereas dilutions below 10-2 were strongly cytotoxic, comparable with the 10-2 dilution of 0.2% peracetic acid. CONCLUSIONS: The vinegar-hydrogen peroxide mixture effectively eliminated C. albicans and S. aureus from acrylic resin. Dilutions equal or below 10-2 of this mixture presented strong cytotoxic effects.

Use of autofluorescence and fluorescent probes as a potential diagnostic tool for oral cancer: A systematic review.

INTRODUCTION: The prognosis of patients with Oral squamous cell carcinoma (OSCC) are directly related to the stage of development of the tumor at the time of diagnosis, but it is estimated an average delay in diagnosis of 2-5 months. New non-invasive techniques for the early diagnosis of OSCC are being developed, such as methodologies to detect spectral changes of tumor cells. We conducted a systematic review to analyze the potential use of autofluorescence and/or fluorescent probes for OSCC diagnosis. MATERIAL AND METHODS: Four databases (PubMed, Scopus, Embase and Web of Science) were used as research sources. Protocol was registered with PROSPERO. It was included studies that evaluated tissue autofluorescence and/or used fluorescent probes as a method of diagnosing and/or treatment of oral cancer in humans. RESULTS: Forty-five studies were selected for this systematic review, of which 28 dealt only with autofluorescence, 18 on fluorescent probes and 1 evaluated both methods. The VELscope® was the most used device for autofluorescence, exhibiting sensitivity (33%-100%) and specificity (12%-88.6%). 5-Aminolevulinic acid (5-ALA) was the most used fluorescent probe, exhibiting high sensitivity (90%-100%) and specificity (51.3%-96%). Hypericin, rhodamine 6 G, rhodamine 610, porphyrin and γ-glutamyl hydroxymethyl rhodamine green have also been reported. CONCLUSION: Thus, the autofluorescence and fluorescent probes can provide an accurate diagnosis of oral cancer, assisting the dentist during daily clinical activity, but it is not yet possible to suggest that this method may replace histopathological examination.

Periodontal Disease Impairs Muscle Recovery by Modulating the Recruitment of Leukocytes.

The purpose of this study is to analyze the impact of periodontal disease (PD) associated with physical exercise on inflammatory mediators and muscle repair. Twenty-four Wistar rats were divided into four groups: control (SH), healthy trained (TH), sedentary with PD (SP), and trained with PD (TP). PD was induced in groups SP and TP while the trained groups performed treadmill exercises for 8 weeks. For the analysis of IL-6, IL-10, TNF-α, and leukocyte count, we collected blood samples. Cryolesions were induced in the tibialis anterior and gastrocnemius, which were analyzed for morphological changes. The presence of PD modified leukocyte counts, while exercise showed an additive role. PD increased levels of IL-6, IL-10, and TNF-α, and physical exercise changed only values of IL-10. The association between physical exercise and PD was responsible for an increased concentration of leukocytes in the region of the inflammation. Serum levels of inflammatory markers were modified by PD and, when combined with exercise, may negatively modulate inflammation. The association between PD and physical exercise showed the most significant changes in the number of inflammatory cells and may negatively influence the process of muscle repair.

Structural Organization of Dental Biofilm Formed in situ in the Presence of Sucrose Associated to Maltodextrin.

Maltodextrins, derived from corn starch, have been added to industrialized food combined with sucrose. However it is not clear the diffusion properties of the dental biofilm matrix and the tridimensional structure of multispecies biofilms formed in the presence of these carbohydrates. Therefore, the aim of study was to investigate by confocal laser scanning microscopy (CLSM) the structural organization of the multispecies dental biofilm formed in situ under exposure to sucrose associated to maltodextrin. Adult volunteers wore an intraoral palatal appliance containing bovine enamel blocks. They were instructed to remove the appliance 8 times per day and drop the following solutions on the enamel blocks: deionized distilled water (DDW), maltodextrin, sucrose + maltodextrin or sucrose. Biofilms formed were stained and the percentage of extracellular polysaccharide (%EPS) and thickness were determined by CLSM. Biofilm formed in the presence of sucrose and sucrose + maltodextrin presented similar %EPS and higher than DDW and maltodextrin. Regarding to the biofilm thickness, sucrose and sucrose + maltodextrin treatments were thicker than DDW and maltodextrin and similar between them. The structural organization of the multispecies dental biofilm formed in situ in the presence of sucrose does not change when this carbohydrate is associated to maltodextrin.

Effects of Low Molecular Weight Heparin on Alveolar Bone Loss in Wistar Rats.

This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Late hyaluronidase injection in local anesthesia: Morphofunctional evaluation in rat sciatic nerve block.

INTRODUCTION: Despite the enhancing effects of hyaluronidase (HYAL) over duration of anesthesia, this enzyme could cause adverse effects when injected concomitantly with local anesthetics in dental blocks. OBJECTIVE: This study aimed to assess the tissue alterations caused by a local anesthetic protocol consisting of a late HYAL injection and confirm its functional effectiveness. MATERIALS AND METHODS: The protocol efficacy was proved by evaluating sensory and motor functions in rats. The sciatic nerve was blocked with 2% lidocaine (LID) with epinephrine (n = 25). Thirty minutes later, 75 TRU/ml HYAL was injected into the same site (experimental group, LID/HYAL). One week later, this protocol was repeated in the contralateral hindlimb, injecting only HYAL's vehicle (control group, LID/vehicle [LID/V]). To observe the integrity of the local tissues, histological specimens were obtained 1, 24, 48, and 72 h after treatment with LID/HYAL or LID/V (n = 16 each) and stained with hematoxylin/eosin and picrosirius red. RESULTS: Local inflammation was similar in both groups. The integrity of the nerve fibers was preserved, in spite of some inflammation-associated injuries in the surrounding tissues. The reversible tissue disorganization caused by HYAL, probably facilitated the diffusion of the residual anesthetic to the nerve, resulting in a prolonged anesthetic effect (P < 0.05). CONCLUSIONS: No irreversible morphological alterations are caused by the administration of HYAL prior the end of the LID-induced block. Moreover, this protocol prolongs LID's anesthetic effect.

Effects of Diabetes and Hypertension on Oral Mucosa and TGFß1 Salivary Levels.

The aim of this study was to investigate salivary levels of TGFß1 and proliferation/ maturation of epithelial mucosa cells in diabetic and hypertensive patients. DESIGN: in this cross-sectional study, whole stimulated saliva and oral mucosa exfoliative cytology specimens were collected from 39 patients that were healthy (control, n=10) or presented history of arterial hypertension (HAS, n=9), diabetes mellitus (DM, n=10) or both (DM+HAS, n=10). Salivary flow rate (SFR), TGFß1 level in saliva, AgNORs and the epithelial maturation were evaluated. Non-parametric Kruskal-Wallis test, followed by Dunn's multiple comparison post-test and the Spearman test correlation analysis were used. SFR showed a significant decreased in DM and DM+HAS (0.47±0.11 and 0.64±0.43 mL/min) when compared to control (1.4±0.38 mL/min). DM+HAS presented the highest value of TGFß1 concentration (24.72±5.89 pg/mL). It was observed a positive correlation between TGFß1 and glycaemia (R=0.6371; p<0.001) and a negative correlation between TGFß1 and saliva (R=-0.6162; p<0.001) and glycaemia and SFR (R=-0.5654; P=0.001). AgNORs number and status of maturation of mucosa cells were similar for all conditions. DM and DM+HAS presented the lowest SFR, which correlated with increased TGFß1 levels. Despite the higher TGFß1 secretion it was not observed changes in the morphology or proliferation of epithelial cells when diabetes or hypertension was present.

Effects of low molecular weight heparin on alveolar bone loss in wistar rats

Abstract This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Resumo O presente estudo objetivou verificar o efeito da heparina de baixo peso molecular (HBPM) sob a perda óssea alveolar (POA), contagem de células sanguíneas, megacariócitos e adipócitos em ratos Wistar machos. Quarenta ratos Wistar de 60 dias foram randomicamente divididos em quatro grupo: Controle (C), Doença Periodontal (DP), Heparina (Hp) e Heparina + Doença Periodontal (Hp+DP). HBPM foi aplicada durante 60 dias em doses de 1 mL/kg/dia. Coletas sanguíneas foram realizadas nos dias 0, 30 e 60. No dia 49, os grupos DP e Hp+DP receberam indução de doença periodontal por ligadura ao redor do segundo molar superior direito. No lado esquerdo, verificou-se perda óssea alveolar espontânea. A média de POA no lado com ligadura mostrou-se estatisticamente diferente entre os grupos C (0,35±0,07 mm) e Hp+PD (0,49±0,09 mm) (p<0,001), entre os grupos DP (0,55±0,11 mm) e Hp (0,32±0,06 mm) (p<0,001) e entre os grupos Hp e Hp+DP (p<0,001). Nenhuma diferente significativa foi observada entre os grupos no lado sem ligadura. Peso dos animais, consumo de ração e ingestão de água não mostraram diferenças significativas entre os grupos. Megacariócitos e adipócitos foram contados por microscopia óptica e nenhuma diferença significativa foi encontrada. Dentro dos grupos, houve um aumento e uma diminuição, respectivamente, na contagem de linfócitos (p=0,005 no grupo C e p=0,009 no grupo Hp+DP somente) e leucócitos (p=0,003 no grupo C, p=0.001 no grupo DP e p=0,002 no grupo Hp e Hp+DP). Não houve diminuição no número de plaquetas nos três períodos de coleta. HBPM não foi capaz de modificar a POA, porém modificou a contagem de células sanguíneas, especialmente aumentando o número de linfócitos.

Effects of diabetes and hypertension on oral mucosa and tgfß1 salivary levels

Abstract The aim of this study was to investigate salivary levels of TGFβ1 and proliferation/ maturation of epithelial mucosa cells in diabetic and hypertensive patients. Design: in this cross-sectional study, whole stimulated saliva and oral mucosa exfoliative cytology specimens were collected from 39 patients that were healthy (control, n=10) or presented history of arterial hypertension (HAS, n=9), diabetes mellitus (DM, n=10) or both (DM+HAS, n=10). Salivary flow rate (SFR), TGFβ1 level in saliva, AgNORs and the epithelial maturation were evaluated. Non-parametric Kruskal-Wallis test, followed by Dunn's multiple comparison post-test and the Spearman test correlation analysis were used. SFR showed a significant decreased in DM and DM+HAS (0.47±0.11 and 0.64±0.43 mL/min) when compared to control (1.4±0.38 mL/min). DM+HAS presented the highest value of TGFβ1 concentration (24.72±5.89 pg/mL). It was observed a positive correlation between TGFβ1 and glycaemia (R=0.6371; p<0.001) and a negative correlation between TGFβ1 and saliva (R=-0.6162; p<0.001) and glycaemia and SFR (R=-0.5654; P=0.001). AgNORs number and status of maturation of mucosa cells were similar for all conditions. DM and DM+HAS presented the lowest SFR, which correlated with increased TGFβ1 levels. Despite the higher TGFβ1 secretion it was not observed changes in the morphology or proliferation of epithelial cells when diabetes or hypertension was present.

Resumo O objetivo deste estudo foi investigar os níveis de TGFβ1 na saliva e a proliferação/maturação das células epiteliais da mucosa em paciente diabéticos e hipertensos. Neste estudo transversal, saliva estimulada e amostras de citologia exfoliativa de mucosa oral foram coletadas de um total de 39 pacientes que se apresentavam saudáveis (controle, n=10) ou com história de hipertensão arterial (HAS, n=9), diabetes mellitus (DM, n=10) ou ambos (DM+HAS, n=10). Taxa de fluxo salivar (SFR), níveis de TGFβ1 na saliva, AgNORs e maturação epitelial foram avaliados. Teste não-paramétrico de Kruskal-Wallis, seguido de comparação múltipla de Dunn e correlação de Spearman foram utilizados para as análises. SFR diminuiu significantemente em DM e DM+HAS (0,47±0,11 e 0,64±0,43 mL/min) quando comparado ao controle (1,4±0,38 mL/min). DM+HAS apresentou os maiores valores de concentração de TGFβ1 (24,72±5,89 pg/mL). Foi observada uma correlação positiva entre TGFβ1 e glicemia (R=0,6371; p<0,001) e uma correlação negativa entre TGFβ1 e saliva (R=-0,6162; p<0,001) e glicemia e SFR (R=-0,5654; p=0,001). Número de AgNORs e o padrão da maturação das células epiteliais foram similares entre os todos grupos. DM e DM+HAS apresentaram os menores valores de SFR, os quais foram correlacionados com o aumento nos níveis de TGFβ1. Apesar da maior secreção de TGFβ1, não foram observadas mudanças na morfologia ou proliferação das células epiteliais quando o paciente apresentava diabetes ou hipertensão.