Cholesterol depletion induces mesenchymal properties in oral squamous cell carcinoma cell line

BACKGROUND

Cholesterol in cell membranes is crucial for cell signaling, adhesion, and migration. Membranes feature cholesterol-rich caveolae with caveolin proteins, playing roles in epithelial-mesenchymal transition and cancer progression. Despite elevated cholesterol levels in tumors, its precise function and the effects of its depletion in oral squamous cell carcinoma remain unclear. The aim of this study was to evaluate the influence of cholesterol depletion in oral squamous cell carcinoma cell line and epithelial-mesenchymal transition process.

METHODS

Cholesterol depletion was induced on SCC-9 cells by methyl-β-cyclodextrin and cell viability, proliferation, apoptosis, and colony formation capacities were evaluated. Gene and protein expressions were evaluated by reverse transcription polymerase chain reaction (RT-qPCR) and Western Blot, respectively, and cell sublocalization was assessed by immunofluorescence.

RESULTS

Cholesterol depletion resulted in alteration of oral squamous cell carcinoma cell morphology at different concentrations of methyl-β-cyclodextrin, as well as decreased cell proliferation and viability rates. Analysis of CAV1 transcript expression revealed increased gene expression in the treated SCC-9 during the 24 h period, at different concentrations of methyl-β-cyclodextrin: 5 , 7.5, 10, and 15 mM, in relation to parental SCC-9. CAV1 protein expression was increased, with subsequent dose-dependent decrease. A statistically significant difference was observed in samples treated with 5 mM of methyl-β-cyclodextrin (p = 0.02, Kruskal-Wallis test). The immunofluorescence assay showed lower cytoplasmic and membrane labeling intensity in the treated samples for CAV1.

CONCLUSION

These findings indicate the modulation of cholesterol as a possible mechanism underlying the regulation of these molecules and activation of epithelial-mesenchymal transition in oral squamous cell carcinoma.

Biomass, photosynthetic activity, and biomolecule composition in Chlorella fusca (Chlorophyta) cultured in a raceway pond operated under greenhouse conditions

Raceways are widely used as microalgae culture systems due to their low cost, but they are not the best option for biomass yield. Understanding in situ photosynthetic performance can be a first step to increase their biomass productivity. This study aimed at comparing the real time photosynthetic activity in a greenhouse raceway culture (250L) with discrete measurements under laboratory conditions. We evaluated the photophysiology and biochemical composition of Chlorella fusca culture up to 120h. In situ photosynthetic activity was continuously monitored and compared to discrete ex situ measurements; biochemical compounds were measured daily. The results showed a final biomass density of 0.45gL^-1 (5 days - 120h) and an increase of the electron transport rate (ETR) up to 48h but decreased thereafter. When the relative ETR was estimated considering the absorption coefficient (a) positive correlations of this parameter with photosynthetic capacity, cell density, biomass, biocompounds and antioxidant activity were obtained, whereas no correlation was detected without considering a. In situ photosynthesis monitoring showed higher absolute maximal ETR (10 - 160 μmol m^-3s^-1) than discrete ex situ measurements. We demonstrated the importance of considering the light absorption coefficient for expressing photosynthetic capacity and showed that C. fusca can produce, in the short-term, bioactive compounds that are correlated to photosynthetic conditions.

Acute total occlusion of the unprotected left main coronary artery – patient characteristics and outcomes

Background

Acute total occlusion of the unprotected left main coronary artery (ATOLMCA) is a dramatic entity with very high mortality. Owing to its infrequency, there is limited and inconsistent data regarding this population.

Purpose

To describe the clinical presentation, short- and long-term outcomes of patients with ATOLMCA.

Methods

This retrospective multicentric cohort study included all patients presenting with acute (<12h) myocardial infarction (MI) due to ATOLMCA (Thrombolysis In Myocardial Infarction - TIMI=0) between January 2008 and December 2020 in three tertiary hospitals.

Results

In the period of the study, 11,036 emergent coronary angiographies were performed in the participating centers, 59 of which were ATOLMCA (0.5%). Mean age of patients at the time of the event was 61.2 (±12.2) years. Seventy-three percent were male. At presentation, 72.9% of patients were in cardiogenic shock, and aborted cardiac arrest occurred in 27.1%. Right dominance was present in all patients except one, who had a balanced dominance. Primary percutaneous coronary intervention (PCI) was performed in 89.8% of the patients, with angiographic success being achieved in 55.6% of the procedures. Overall, the in-hospital mortality rate was 57.6%. Mortality was significantly higher in patients without angiographic criteria for PCI success (87.5 vs 36.7%, p<0.001). Among survivors, 91.7% were still alive at 1-year and 66.7% at 5 years of follow-up.

Conclusion

Patients with ATOLMCA have a dismal prognosis. Most patients present with cardiogenic shock, and a significant number develop cardiac arrest during the acute phase. Despite medical care, in-hospital mortality is high. Patients with left dominance may not even reach the hospital. Among survivors, long term outcomes are reasonable. Further studies are needed in order to improve the management and outcomes of patients with ATOLMCA.

Funding Acknowledgement

Type of funding sources: None.

Percutaneous valve commissurotomy in mitral stenosis patients: a 20 years follow-up

Background

Percutaneous valve commissurotomy (PMC) is a viable alternative to mitral valve surgery in the treatment of patients with clinically significant mitral stenosis (MS). Although rheumatic MS incidence has decreased in developed countries, it remains a prevalent healthcare problem in Cardiology clinics

Purpose

To evaluate the early and long-term results of PMC in patients with rheumatic MS and to compare long-term events between patients with and without pulmonary hypertension (PH).

Methods

We retrospectively analysed all consecutive patients between 1991 and 2008 with clinically significant rheumatic MS undergoing PMC. Clinical and echocardiographic data were collected at baseline and during long-term follow-up. MACE was a composite of adverse events defined as all-cause mortality, mitral valve re-intervention or hospitalization for a cardiovascular cause.

Results

A total of 124 patients were enrolled: 87% were female, with a mean age at the time of repair of 46±11 year-old and a mean follow-up of 20±6 years. Before the procedure, 34% were in NYHA class ≥ III and 81% had a Wilkins score ≤8; all patients had preserved biventricular systolic function, 83% presented PH, mean transvalvular gradient (TVG) and mitral valve area (MVA) were 12.8 mmHg and 1.0 cm2, respectively. Most of the procedures were successful (91%) and without complications (94%), with a mean MVA improvement of 0.9 cm2 and reduction of 8.5 mmHg in TVG and 9.7 mmHg in pulmonary artery systolic pressure (PASP) after PMC.

During long-term follow-up, 42% of patients were submitted to re-intervention (most of them surgically) and 24% died. In patients non-submitted to re-intervention, TVG and PASP remained similar with early post-procedure evaluation (p=0.109 and p=0.777, respectively), while MVA reduced over time, yet still statistically superior to baseline MVA (1.6 cm2 vs 1.0 cm2, p<0.001). Concerning time-to-event analysis, approximately 80% of patients kept uneventful after 10 years; after 30 years, more than 20% continued MACE-free and approximately 50% were alive. Regarding PH presence at time of PMC, there was no significant difference in MACE events and all-cause mortality between the two groups (Log Rank, p=0,846 and p=0.661, respectively).

Conclusion

PMC was safe and effective in clinically significant rheumatic MS. After a long-term follow-up patients maintained the reduction in TVG and PASP and a smaller but significative improvement in MVA. Most of the patients were free from adverse events after 10 years and half were alive after 30 years. There was no difference in all-cause mortality and in a composite of all-cause death, mitral valve re-intervention or cardiovascular hospitalization concerning PH presence.

Funding Acknowledgement

Type of funding sources: None.

Long-term success in percutaneous valve commissurotomy – is Wilkins score over 9 a definitive limit?

Background

Percutaneous valve commissurotomy (PMC) is an established treatment in patients with significative mitral stenosis (MS). Although rheumatic MS incidence has decreased in the last century, it remains a prevalent pathology worldwide. The Wilkins score (WS) is a reference in echocardiographic assessment of MS; a score ≤8 is considered a predictor of treatment success and score between 9 and 11 is a “grey zone” (WGZ) in which doubts persists regarding PMC success.

Purpose

To evaluate the early and long-term results of PMC in patients with rheumatic MS and to compare long-term events between patients with WS ≤8 and patients in WGZ.

Methods

We retrospectively analysed all patients between 1991 and 2008 with significative rheumatic MS undergoing PMC. Data were collected at baseline and during long-term follow-up. M ACE was defined as a composite of all-cause mortality, mitral valve re-intervention or cardiovascular hospitalization.

Results

In our cohort, 124 patients were included. Most were female (87%), mean age at the time of repair was 46±11 year-old and mean follow-up was 20±6 years. Before the procedure, 81% had WS ≤8 and 19% were in WGZ. Both groups had similar baseline characteristics, namely age at first intervention, NYHA class and follow-up time. All patients had preserved biventricular systolic function, 83% presented PH, mean transvalvular gradient (TVG) and mitral valve area (MVA) were 12.8 mmHg and 1.0 cm2, respectively. Most of the procedures were successful (91%) and without complications (94%). Mean MVA improvement was similar in both groups [0.9 cm2 in WS ≤8 and 0.8 cm2 in WGZ, t(102)=0.173, p=0.863]; there was also no significative difference in TVG and PASP reduction after PMC. During long-term follow-up, re-intervention and mortality occurred in 40% and 23% in WS ≤8 and in 50% and 29% in WGZ, respectively, and none of these differences was statistically significant (p=0.389 and p=0.544, respectively). Concerning time-to-event analysis, approximately 80% of patients kept uneventful and >90% alive after 10 years in both groups and no significant difference in M ACE events and all-cause mortality between WS ≤8 and WGZ was observed (Log Rank, p=0,419 and p=0.950, respectively).

Conclusion

PMC was safe and effective in clinically significant rheumatic MS in both WS ≤8 and WS 9–11, with similar MVA improvement. After 10 years, approximately 80% of patients were MACE-free and >90% alive in both groups. There was no difference in all-cause mortality and in a composite of all-cause death, mitral valve re-intervention or cardiovascular hospitalization concerning WS groups.

Funding Acknowledgement

Type of funding sources: None.

20 year-follow up of mitral stenosis patients after percutaneous valve commissurotomy: moderate disease of other valves as predictor for re-intervention

Background

Percutaneous valve commissurotomy (PMC) is a viable alternative to mitral valve (MV) surgery in the treatment of patients with clinically significant mitral stenosis (MS). About 40% of patients treated with PMC will require at least one reintervention (either PMC or MVS) along time.

Purpose

To evaluate the long-term results of PMC in patients with rheumatic MS.

Methods

We retrospectively analysed all consecutive patients between 1991 and 2008 with clinically significant rheumatic MS undergoing PMC. Clinical and echocardiographic data were collected at baseline and during early and long-term follow-up. MACE was a composite of adverse events defined as all-cause mortality, MV re-intervention or cardiovascular hospitalization.

Results

A total of 124 patients were enrolled: 108 (87%) were female, with a mean age at the time of PMC of 46±11 years.

At baseline, 34% patients were in NYHA class ≥ III and 81% had a Wilkins score ≤8; all patients had preserved biventricular systolic function and 83% presented pulmonary hypertension. Regarding associated valve disease, 46 patients had mild tricuspid regurgitation (TR), 19 mild aortic regurgitation (AR), 14 moderate IT and 5 moderated AR.

Most of the procedures were successful (91%) and without complications (94%), with median improvement in MV area of 0.9 cm2 (IQR 0.5) and median reductions in mean transmitral gradient (MTG) of 6 mmHg (IQR 6) and in pulmonary artery systolic pressure (PASP) of 8 mmHg (IQR 10) early after PMC.

During the mean follow-up of 20±6 years, 52 (42%) of patients had MV re-intervention (86% surgery and 14% re-PMC), 37 (30%) were hospitalized and 30 (24%) died. Concerning time-to-event analysis, approximately 80% of patients kept MACE-free after 10 years; after 30 years, more than 20% continued MACE-uneventful, approximately 50% were alive and about 45% were free from re-intervention.

Considering patients submitted to surgical re-intervention, 9 underwent MV valvuloplasty and the others MV replacement with mechanical (32) or biological prothesis (11). At the same procedure, 23 patients were submitted to tricuspid annuloplasty, 9 to other valve replacement and one to coronary artery bypass graft.

Using Cox regression, we found that the presence of moderate disease of other valves at PMC time was associated with a 2.3-fold greater rate of re-intervention compared to patients with none or mid disease of other valves (HRcrude 2.3; 95% IC 1.221–4.331, p=0.017). After adjusting for the success of the PMC and for mitral regurgitation after PMC, the observed effect remained significant (HRadjusted = 2.7; 95% CI 1.417–5.233, p=0.003).

Conclusion

PMC was safe and effective in clinically significant rheumatic MS. Most of the patients were free from adverse events after 10 years and half were alive after 30 years. Still, about 40% required re-intervention, with moderate disease of other valves as its independent predictor.

Funding Acknowledgement

Type of funding sources: None.

Mechanisms of immune evasion by head and neck cancer stem cells

Different mechanisms are involved in immune escape surveillance driven by Oral and Head and Neck Cancer Stem Cells (HNCSCs). The purpose of this review is to show the most current knowledge regarding the main impact of HNCSCs on tumor evasion through immunosuppression, CSCs phenotypes and environmental signals, highlighting strategies to overcome immune evasion. The main results drive the participation of cell surface receptors and secreted products and ligands, the crosstalk between cells, and genetic regulation. The reduction in CD8+ T cell recruitment and decreased effector of anti-PD-1 therapy by cells expressing BMI1 is a key event; Natural Killer cell ligands and cytokines needed for its activation and expansion are crucial to control tumor growth and to target CSCs by immunotherapy; CSCs expressing ALDH1 are related to increased expression of PD-L1, with a positive link between DNMT3b expression; CD276 expression in CSCs can act as a checkpoint inhibitor and together with Activator Protein 1 (AP-1) activation, they create continuous positive feedback that enables immune evasion by suppressing CD8+ T cells and prevent immune cell infiltration in head and neck cancer. These data demonstrate the relevance of the better understanding of the interaction between HNCSCs and immune cells in the tumor microenvironment. The ultimate clinical implication is to ground the choice of optimized targets and improve immune recognition for ongoing treatments as well as the response to approved immunotherapies.

Oral manifestations of multisystemic inflammatory syndrome in children (MIS-C) and Kawasaki disease associated to COVID-19: A systematic review

Aims

Multisystemic inflammatory syndrome in children (MIS‐C) is a condition noted in some children asymptomatic but positive to Sars‐cov‐2 antibody and it presents clinical and laboratory changes similar to Kawasaki disease (KD). Oral changes have also been observed. This systematic review evaluated oral manifestations detected in children with MIS‐C and KD associated to COVID‐19.

Methods and Results

This work was registered at PROSPERO (#CRD42020225909), following PRISMA guidelines. A comprehensive research was conducted in MEDLINE, Web of Science, EMBASE, LILACS, Scopus, and Grey Literature through August 2021, based on original research evaluating children diagnosed with MIS‐C or KD related to COVID‐19. Two authors independently screened all retrieved references. Twenty five selected studies evaluated 624 children, mean age 8.78 years. The assessment of the risk of bias (ROB) showed that most of them presented low ROB. Oral manifestations were erythematous mucous membrane, oral ulcers lesions, dry, swollen and cracked lips, and strawberry tongue.

Conclusion

MIS‐C and KD share the same oral manifestations and their identification may lead to an early diagnosis.

The role of coronary collateral circulation in patients presenting with acute left main coronary artery occlusion

Introduction

Acute occlusion of the unprotected left main coronary artery (LMCA) is an uncommon occurrence associated with a dismal prognosis. Whereas the role of early recruited coronary collateral circulation (CC) in prognosis of ST-segment elevation acute myocardial infarction (STEMI) patients is still controversial, it seems to be important in patients with acute LMCA occlusion. This study aimed to evaluate the coronary CC in patients with acute LMCA occlusion and its impact in short and long-term outcomes.

Methods

In a retrospective two-center study, we identified 7630 patients with STEMI or high-risk non-ST segment elevation myocardial infarction who underwent emergent coronary angiography between January 2008 and December 2020. Among this cohort, we analyzed 83 patients who presented with unprotected LMCA acute occlusion (Thrombolysis In Myocardial Infarction – TIMI ≤2) and classified them in 2 groups based on the degree of CC through the right coronary artery as seen in the emergent angiography: patients with no filling of collateral vessels or filling of collateral vessels without any epicardial filling of the occluded vessel [Rentrop class 0–1 (71 patients)]; and patients with partial or complete epicardial filling by collateral vessels [CC Rentrop class 2–3 (12 patients)].

Results

Compared to patients with CC Rentrop 0–1, patients with CC Rentrop 2–3 presented significantly later to medical attention (symptom to coronary angiography time 8.7 vs 4.3 hours, p=0.02). Despite that, patients with CC Rentrop 2–3 had a significantly lower prevalence of cardiogenic shock at admission (16.7 vs 57.7%, p=0.01). During hospitalization, Killip class III-IV presentation (33.3 vs 88.7%, p<0.001) and inotropic/vasopressor therapy use (25.0 vs 69.0%, p=0.01) were less frequent in CC Rentrop 2–3 patients. The CC Rentrop 2–3 group had a significantly lower in-hospital (16.7 vs 53.5%, p=0.02) and 30-day mortality (9.1 vs 52.2%, p=0.01). In patients surviving hospitalization there was no significant difference in 1-year (30.0 vs 19.4%, p=0.48) and 5-year mortality (70.0 vs 77.4%, p=0.68).

Conclusion

A well-developed coronary CC was associated to lower short-term mortality in patients presenting with acute occlusion of the unprotected LMCA. Nevertheless, in patients surviving index-event, there was no difference in the long-term outcomes. Further studies are needed to clarify if clinical approach (eg. early short-term mechanical circulatory support) of patients with CC Rentrop 0–1 should be different from those with CC Rentrop 2–3 in order to improve the outcomes of the former patients.

Funding Acknowledgement

Type of funding sources: None.

Cardiogenic shock in patients presenting with acute left main coronary artery occlusion

Background and purpose

Acute myocardial infarction (AMI) due to left main coronary artery (LMCA) occlusion is a rare event, often catastrophic. Limited data are available about management and outcomes of patients with acute LMCA occlusion, including those presenting with cardiogenic shock (CS) at hospital admission. This study sought to describe patients with AMI due unprotected LMCA occlusion presenting with CS and to evaluate their in-hospital outcomes and 1-year mortality.

Methods

In this retrospective 2-center study, we identified 7630 patients with ST-segment elevation myocardial infarction (STEMI) or hight risk non-ST segment elevation myocardial infarction who underwent to emergent coronary angiography between January 2008 and December 2020. Among this cohort, we analysed 94 patients who presented with unprotected LMCA occlusion (Thrombolysis In Myocardial Infarction – TIMI ≤2) and divided them in 2 groups according to presence of signs of cardiogenic shock at admission: CS and no-CS.

Results

Of 94 patients with AMI due LMCA occlusion, 52 patients presented with CS (53.3%). Mean age was 62.8±11.5 years in CS and 62.0±15.9 years in no-CS patients, p=0.766. In both groups, most patients were male. STEMI presentation was more frequent in CS group (80.4% vs. 52.4%, p=0.004). Severe systolic dysfunction of left ventricle was more frequent in CS patients (81.1% vs. 33.3%, p<0.001). Compared to no-CS patients, CS group shown more often TIMI=0 (67.3% vs. 26.2%, p<0.001), collateral coronary circulation Rentrop 0–1 (95.3% vs. 75.0%, p=0.008), and slow-reflow/no-reflow phenomena (30.6% vs 3.8%, p=0.019) in emergent coronary angiography. The need of invasive mechanical ventilation (68.9% vs. 21.4%, p<0.001), and haemodialysis (20.5% vs. 2.4%, p=0.010) were more prevalent in CS patients. Likewise, mechanical circulatory support (MCS) was more frequently used in patients presented with CS (52.9% vs. 26.2%, p=0.009). In subgroup analysis, MCS implantation was not a survival predictor in CS patients (Odds ratio: 3.9 [95% confidence interval: 0.4 to 36.3], p=0.229). Ultimately, in-hospital mortality (78.8% vs. 16.7%, p<0.001) was higher in CS patients. On the other hand, in hospital survivors, there was no significant differences in 1-year mortality (11.1% vs. 23.5%, p=0.42) between both groups.

Conclusions

Nearly half of patients with AMI due LMCA occlusion presented with CS signs at first medical evaluation. This subgroup of patients had higher in-hospital mortality compared to those without CS, despite MCS implantation. Whether the use of a specific MCS device or whether early use of MCS can change the outcome remains to be elucidated. CS patients who survive to index-hospitalization, had similar long-term outcomes compared to no-CS patients. Further studies are imperative in this population to refine initial medical treatment in order to improve their prognosis.

Funding Acknowledgement

Type of funding sources: None.

Antinociceptive and anti-inflammatory activities of Hymenaea martiana Hayne (Fabaceae) in mice

Hymenaea martiana is a species popularly known in Northeastern Brazil as "jatobá" and used in folk medicine to treat pain and inflammation. The aim of this work was to evaluate the antinociceptive and anti-inflammatory activity of H. martiana. In the present study, we carried out an investigation about the effects of the crude ethanolic extract (Hm-EtOH) and the ethyl acetate fraction (Hm-AcOEt) in models of nociception and inflammation in mice. Chemical (acetic acid-induced writhing and formalin) and thermal stimuli (hot plate) were used for the evaluation of antinociceptive activity, while for the anti-inflammatory profile paw edema induced by carrageenan was used, along with leukocyte migration to the peritoneal cavity. The presence of the flavonoid astilbin in the samples was characterized through HPLC-DAD-MS analysis. Hm-EtOH and Hm-AcOEt (100, 200 and 400 mg.kg-1, i.p.) significantly reduced the number of abdominal contortions and decreased the paw licking time in the formalin test. In the hot plate, the extract increased the latency time of animals. Hm-EtOH and Hm-AcOEt inhibited significantly the increase in the edema after the administration of carrageenan. Hm-EtOH and Hm-AcOEt inhibited leukocyte migration in the peritonitis test. HPLC-DAD-MS analysis of Hm-EtOH and Hm-AcOEt revealed the presence of the flavonoid astilbin in the samples. According to the results of this study, both Hm-EtOH and Hm-AcOEt have antinociceptive and anti-inflammatory activities, which could be related with the presence of flavonoid in the extracts. The results reinforce the popular use of this plant.

Effect of treatment of pneumonia and otitis media with tildipirosin or florfenicol + flunixin meglumine on health and upper respiratory tract microbiota of preweaned Holstein dairy heifers

The objective of this randomized clinical study was to compare the effect of 2 antimicrobial interventions, tildipirosin or florfenicol + flunixin meglumine, used for treatment of pneumonia and extralabel treatment for otitis on health parameters and upper respiratory tract (URT) microbiota of preweaned Holstein calves. Housed preweaned Holstein heifers diagnosed with either otitis or pneumonia were assigned into 1 of 2 treatment groups, receiving a single subcutaneous injection of either 4 mg/kg of tildipirosin (TLD; n = 444) or 40 mg/kg of florfenicol combined with 2.2 mg/kg of a nonsteroidal anti-inflammatory, flunixin meglumine (FLF; n = 442). Calves were enrolled and treated on the day of diagnosis of the first case of pneumonia or otitis. If a calf had a recurrent case, the opposite drug was administered, respecting an interval of 5 d between drug injections. Blood samples for leukocyte counts were collected at 0, 2, 4, and 6 d after treatment, and rectal temperature was measured daily during the 5 d after treatment. Ear scores were observed from calves with otitis. Additionally, swabs of the URT were collected from a subset of 20 calves in each treatment group at d 0, 3, 6, 9, and 11 following enrollment for analysis of URT microbiota through next-generation sequencing of the 16S rRNA gene and quantitative PCR. Swabs were also collected from a comparative group of 20 healthy calves that did not receive any drug. No differences were observed between groups for recurrence risk of either pneumonia (TLD = 32.4%; FLF = 29.7%) or otitis (TLD = 72.7%; FLF = 73.6%). Similarly, no differences were observed for the total number of treatments for pneumonia (TLD = 1.45; FLF = 1.42) or otitis (TLD = 2.96; FLF = 3.07). On the other hand, both drugs reduced rectal temperature, ear scores, and leukocyte counts, with FLF calves having a greater reduction in rectal temperature within 4 d after treatment. Both TLD and FLF reduced the total bacterial load when compared with healthy untreated calves, but no differences were observed between treatment groups. Furthermore, compared with the untreated group, treated calves had lower mean relative abundances (MRA) of the genera Mannheimia, Moraxella, and Pasteurella within 11, 9, and 3 d after treatment, respectively; however, no significant differences were observed between TLD and FLF. On the other hand, MRA of Mycoplasma was not decreased by both treatments compared to untreated animals, and a higher MRA was observed in the TLD group during 11 d after treatment in comparison to FLF and untreated calves. Based on this data, we concluded that both drugs used in the study were effective in reducing rectal temperature, ear scores, leukocyte counts, and MRA of the genera Mannheimia, Pasteurella, and Moraxella in the URT, and calves treated with FLF had a greater reduction in rectal temperature.

Conduction disturbances after TAVR - a 1-year follow-up

Funding Acknowledgements

Type of funding sources: None.

Introduction

Transcatheter aortic valve replacement (TAVR) is an established procedure to treat patients (pts) with symptomatic severe aortic stenosis. Although conduction disturbances remain the most frequent complication, there is a lack of consensus on their management, which leads to significant differences in permanent pacemaker (PPM) implantation rates between centers.

Purpose

To evaluate new conduction disturbances and PPM implantation in pts undergoing TAVR, peri-procedure and up to 1 year.

Methods

We retrospectively analyzed all pts who underwent TAVR at a tertiary center from October 2014 to November 2019; pts with a previous PPM were excluded (n = 30). Clinical and ECG data were collected at presentation and up to 1 year after implantation, including systematic interrogation of implanted PPM.

Results

340 pts underwent TAVR (57% female, mean age 80 ± 8years). CoreValve Evolut R was the most used valve (41% of pts), followed by CoreValve Evolut Pro (21%) and Acurate Neo (13%). Of the 77% pts who were in sinus rhythm pre-TAVR, 79% had normal atrioventricular (AV) conduction and 20% 1st degree AV block (AVB); 60% had no intraventricular (IV) conduction disturbance, 9% left bundle branch block (LBBB), 7% right bundle branch block (RBBB) and 7% RBBB plus fascicular block.

After TAVR, 50.9% of pts exhibited new conduction disturbances. Regarding AV conduction, 12.4% of pts developed advanced AVB and 20% of pts without previous disturbances developed 1st degree AVB. Concerning IV conduction, the most frequent disturbance was de novo LBBB (n = 109, 32,2%) which resolved in 56% of cases after 6 months. Among pts with previous RBBB, 42% developed advanced AVB; the presence of previous RBBB was the major risk factor for advanced AVB [OR = 8.5 (95% CI 4.1-17.5; p < 0.001)] and PPM implantation [OR = 5.2 (95% CI 2.7-10.0; p < 0.001)], followed by previous 1st degree AVB [OR = 2.3 (95% CI 1.2-4.4; p = 0.016) for PPM implantation]; previous FA or LBBB were not associated with advanced AVB or PPM implantation.

Overall, 19% of pts implanted a PPM post-TAVR (n = 63). The main reason was advanced AVB (60%), followed by LBBB plus 1st degree AVB (22%), isolated LBBB (5%) and alternating bundle branch block (ABBB) (5%). At first PPM evaluation, pts with advanced AVB had a median percentage of ventricular pacing (VP) of 80% (52% had VP >90% and 14% <1%) and one year after-TAVR the median percentage of VP was 83%. Concerning pts with LBBB plus 1st degree AVB, median VP at first assessment was 4% (38% had < 1% of VP). In pts with isolated LBBB or ABBB, median VP at first evaluation was 13% and 11%, respectively.

Conclusion

LBBB was the most frequent de novo conduction disturbance after TAVR, with more than half of the cases resolving in the first 6 months. RBBB, on the other hand, was the major risk factor for advanced AVB and PPM implantation. Advanced AVB was associated with a high percentage of VP at 1-year follow-up, unlike pts with milder degrees of conduction delay.

Liquid Storage of Geophagus brasiliensis semen in the Presence of Different Extenders

BACKGROUND

In order to preserve the genetic diversity of cichlid fish in gene banks, it is necessary to use certain extenders to maintain the integrity of spermatozoa cells during cooling.

OBJECTIVE

To evaluate the effects of different extenders on the quality parameters of cooled semen of Geophagus brasiliensis.

MATERIALS AND METHODS

Semen samples were collected from seven adult fish and diluted with five extenders: Beltsville Thawing Solution (BTS™), Hanks' Balanced Salt Solution (HBSS), Tris-glucose, Ginsburg's Fish Ringers, and Phosphate buffered Saline. All parameters were evaluated in fresh semen samples and after cooling at 4°C at 0, 24, 48, and 96 h to evaluate cell viability (membrane integrity, DNA, and mitochondrial functionality) and motility rate and weather motility.

RESULTS

The BTS and Tris-glucose resulted in the best outcomes (P<0.05) in terms of membrane integrity assessments (35.1% and 30.9%, respectively), DNA integrity (71.6%; 75.7%), mitochondrial function (26.9%; 28.0%) and motility rate (8.6%; 8.6%), respectively, for semen cooled to 4°C for 96 h. However, the 48-h period motility after cooling in BTS was superior to all other treatments.

CONCLUSION

BTS and Tris-glucose can be considered as the best extenders for the cold storage of Geophagus brasiliensis spermatozoa.

Evaluation of the sensitivity of the Express View function in the Mirocam® capsule endoscopy software

Background: A new computer algorithm called Express-View has recently been introduced by Mirocam, but data concerning its application and efficacy are scarce.Objective: To evaluate the lesion detection rate, per-patient sensitivity and the diagnostic accuracy using Express-View.Methods: All patients who performed CE between January 2018 and June 2019, whose indication was obscure gastrointestinal bleeding (OGIB) and with findings on CE, were included. Lesions identified in conventional reading were selected and considered as reference.Results: Eighty-nine patients were included, 50.6% male, with a mean age of 68.4 years-old (±12.3). The Express-View mode detected 85.5% of lesions previously detected by conventional reading (524 out of 613). There were 89 missed lesions, mainly erosions or ulcers (44.9%) and angioectasias (38.2%). The lesion detection rate was found to be lower in the jejunum and ileum compared to extra-small bowel locations and duodenum (p = .04). Although Express-View had a per-patient sensitivity for all lesions of 56.2% and a per-patient sensitivity for all clinically significant lesions of 83.1%, it achieved a diagnostic accuracy of 91%.Conclusions: The per-patient sensitivity for all lesions was shown to be below expectations, although the lesion detection rate, the per-patient sensitivity for all clinically significant lesions, and the diagnostic accuracy were shown to be higher.

P863 Large pericardial effusion two months after transcatheter aortic valve implantation: case report of a post-cardiac injury syndrome

We present a case of a 87-year-old female with a symptomatic severe aortic stenosis (aortic valve area 0.9 cm2, mean transvalvular pressure gradient 44 mmHg). She was refused to surgical aortic valve replacement due to marked aortic root calcification. A transcatheter aortic valve (ACCURATE neo™ 27) was electively implanted. In immediate post-procedure, the patient presented an episode of hypotension, rapidly reverted with supportive treatment. A transthoracic echocardiogram (TTE) showed a circumferential mild pericardial effusion (PE) without prosthetic valve disfunction and with preserved biventricular systolic function. Due to paroxysmal episodes of atrial fibrillation, it was decided to withdraw anti-aggregation and to start anticoagulation. Four days after transcatheter aortic valve implantation (TAVI) the patient presented newer intraventricular and atrioventricular conduction disturbance (left bundle branch block and type-I second-degree atrioventricular block). A definitive pacemaker was implanted without complications. PE maintained stable and seven days after TAVI the patient was discharged from hospital.

Two months after TAVI, the patient was admitted to Intensive care unit (ICU) with increasing asthenia, dyspnea and pleuritic thoracic pain over the preceding two weeks. Laboratory workup exhibited elevation of inflammatory markers (leukocytosis and C-reactive protein). A TTE was performed and showed a large circumferential PE (29 mm) with signs of hemodynamic impact (swinging heart, inferior vena cava dilation with &lt;50% inspiratory collapse, right atrial collapse &gt;1/3 of cardiac cycle, proto-diastolic right ventricular collapse and mitral respiratory flow variation &gt;25%). The patient started treatment with anti-inflammatory drugs (aspirin 1000mg every 8h plus colchicine 0.5mg twice daily) and pericardiocentesis was initially postponed. In spite of clinical and echocardiographic improvement, she maintained elevated inflammatory markers and a moderate PE. Prednisolone 30mg daily was added to initial therapy and serial evaluations showed a pronounced reduction of PE as well as of inflammatory markers. Two weeks after admission to ICU the patient was discharged with a residual PE measuring less than 5mm. The previous recent cardiac intervention and the effective response to anti-inflammatory treatment suggest a post-cardiac injury syndrome.

This case report wants to show that post-cardiac injury syndrome is a diagnosis that should be keep in mind after TAVI.

Abstract P863 Figure. TTE showing large pericardial effusion

1414Vasodilator challenge with levosimendan as alternative to nitric oxide in advanced heart failure heart transplant candidates

Introduction

Vasodilator challenge (VC) during right heart catheterization in heart transplant (HTx) candidates is warranted whenever pulmonary artery (PA) systolic pressure ≥50 mmHg and either transpulmonary gradient (TPG) ≥15 mmHg or pulmonary vascular resistance (PVR) >3 WU as long as systolic arterial blood pressure >85 mmHg. Nitric oxide (NO) remains the mainstay but in doubtful cases a 24–48h course of diuretics, inotropes and vasoactive agents may be required. Our aim is to report our centre's experience with levosimendan (LEVO) as alternative to NO in VC in HTx candidates due to advanced heart failure (HF).

Methods

VC records with either NO (20 ppm for 5–10 mins) or within 72h of LEVO infusion (12 mg/kg/min for 24–48h) carried out between 2009 and September 2018 were retrieved from the centre's database. Analysis was carried out with Fisher's exact test or Student's t-test for categorical and continuous variables, respectively, or the equivalent non-parametric test for non-normal distribution variables. Data are presented as counts and percentage, or mean ± standard deviation and median, percentile 25–75, for categorical and continuous variables, respectively.

Results

Baseline demographic and clinical characteristics from 26 patients (NO=13; LEVO=13) were similar between groups (12% female; 54±10 years of age; left ventricular ejection fraction 20±7%; BNP 1550±1090 pg/mL; 88% on NYHA III-IV). Although no differences were observed in baseline cardiac index (CI, 1.6±0.3 vs 1.4±0.4 L/min.m-2, in NO and LEVO, respectively), LEVO patients showed higher right ventricular systolic (70±10 vs 60±13 mmHg; p=0.036) and diastolic pressures (16±4 vs 11±5 mmHg; p=0.009) and lower PA compliance (0.9±0.2 vs 1.3±0.4 ml/mmHg; p=0.007) as well as a trend for increased PA wedge pressure (26±4 vs 21±4 mmHg; p=0.09), translating worse hemodynamics. Upon VC only LEVO decreased PA pressure and the increase in CI was higher compared with NO (2.5±0.8 vs 1.9±0.5 L/min.m-2, p=0.004) thus PVR reduction was comparable between groups (7.8±2.7 to 4.7±1.8 vs 6.3±2.3 to 3.6±2.1 WU, respectively). Also, only LEVO increased right (497, 387–837 to 791, 570–946 mmHg.mL.m-2; p=0.006) and left ventricular stroke work index (895, 807–1364 to 1257, 1107–2957 mmHg.mL.m-2; p=0.005) and cardiac power output (0.4±0.1 to 0.6±0.1 W; p<0.001). Increase in PA compliance was also higher in LEVO (89±98 vs 22±30 Δ%, p=0.04). On the other hand, NO increased wedge pressure whereas LEVO had no effect thus TPG reduction was higher with NO (42±24% vs 17±27% drops, respectively; p=0.022). After HTx (NO=4; LEVO=10) mortality was similar in both groups (25% vs 30%; p=1.00).

Conclusion

LEVO is a safe and effective alternative in PVR reduction for VC. Its positive inotropic effect and long-lasting hemodynamic improvement may improve clinical status before HTx and allow better scrutiny of suitable candidates.

Fractions of Selaginella convoluta (Arn.) Spring (Selaginellaceae) attenuate the nociceptive behavior events in mice

Selaginella convoluta (Arn.) Spring is a species popularly known as "jericó", and used in folk medicine as analgesic and anti-inflammatory. This study aimed to investigate in mice the antinociceptive and anti-inflammatory activities of the hexane (Sc-Hex) and chloroform (Sc-CHCl3) fractions (100, 200 and 400 mg/kg) obtained by partition of crude ethanol extract from S. convoluta. The preliminary phytochemical analysis of the fractions was performed. Antinociceptive activity was evaluated by writhing, formalin and hot-plate tests. Anti-inflammatory activity was evaluated using carrageenan-induced pleurisy. The rota-rod test was used to evaluate motor coordination. Preliminary phytochemical screening showed that the Sc-Hex and the Sc-CHCl3 were positive for the presence of flavonoids, anthracene derivatives, quinones, triterpenes and steroids. Inhibition of writhing was observed for fractions tested. The Sc-Hex at all doses tested was effective in reducing the nociceptive behavior produced by formalin only in the second phase. However, the Sc-CHCl3 decreased the paw licking time in the first and second phases. In the hot plate no significant effect was observed for any fraction. In the rota-rod test, treated mice did not demonstrate any significant motor performance changes. In the carrageenan-induced pleurisy, Sc-CHCl3 (200 mg/kg) reduced cell migration to the pleural cavity. These results reveal the antinociceptive properties of S. convoluta , which support, in part, its traditional use, since the fractions did not presented significant activity in the inflammatory response profile. We further verify that this antinociceptive effect could be by activation of nociceptive peripheral pathway.

Agentes Inibidores da Atividade Proteolítica em Dentina: uma Revisão da Literatura

O objetivo foi revisar a literatura acerca de alguns dos agentes capazes de regular a atividade proteolítica dentinária. Foi realizada uma busca nas bases de dados Pubmed e Bireme, através dos descritores “matrix metalloproteinases”, “dentin” e “longevity”, considerando artigos em inglês e em português, entre 2007 e 2017. Foram obtidos 38 artigos, sendo 24 in vitro, 1 ensaio pré-clínico, 12 revisões de literatura e 1 caso clínico. Através de uma leitura crítica dos títulos e dos resumos foram selecionados 10, relevantes ao tema. Artigos que não se adequavam ao objetivo do trabalho foram excluídos. A clorexidina é capaz de preservar a integridade estrutural do colágeno, inibindo MMPs dos tipos 2, 8 e 9 e CC, entretanto mostra perda da sua substantividade ao longo do tempo. A galardina é um inibidor sintético de MMPs dos tipos 1, 2, 8 e 9, e possui ação em concentrações bem menores que a clorexidina. Os compostos de amônia quaternária inibem MMPs dos tipos 2, 8 e 9, impedindo significativamente a degradação do colágeno da dentina desmineralizada. Os bisfosfonatos podem ser potenciais inibidores de MMPs devido a quelação de íons de zinco e de cálcio, porém a literatura ainda é escassa. Dado o exposto, notam-se evidências satisfatórias, contudo ainda são necessários mais estudos sobre a aplicabilidade e efetividade clínica de tais agentes reguladores.Palavras-chave: Matrix Metalloproteinases. Dentin. Longevity.

Ácido Fítico e Ácido Metafosfórico como Agentes Alternativos para Condicionamento Dentinário: uma Revisão da Literatura

O objetivo do presente estudo foi realizar uma revisão de literatura sobre a ação do ácido fítico (IP6) e do ácido metafosfórico (MPA) como agentes condicionantes em dentina e avaliar seus respectivos resultados. Foi realizada uma busca nas bases de dados Pubmed, e Science Direct, entre 2013 e 2017, utilizando os descritores, separados e em combinação, “Phytic acid”, “Metaphosphoric acid” e “Dentin”. Foram obtidos 12 artigos no total, desses 3 estavam repetidos e foram excluídos. Dos demais, 8 eram estudos    in vitro e 1 era revisão de literatura. Através de uma leitura crítica dos títulos e dos resumos, foram selecionados 6, relevantes ao tema. Artigos de revisão de literatura e que não se adequavam ao objetivo do trabalho foram excluídos. Muitas estratégias são testadas com a finalidade de aumentar a longevidade das interfaces adesivas, recentemente foi proposto que IP6 e MPA poderiam ser usados como agente de condicionamento dentinário. O uso do MPA, os valores de resistência de união são melhores que os obtidos com o ácido ortofosfórico (OPA), padrão-ouro odontológico, além disso, é possível observar que o MPA desmineraliza menos a dentina que o OPA, além de formar o mineral bruxita que melhora a durabilidade da interface adesiva. Os achados em relação ao IP6 também apontam para valores de resistência de união similares ao PA, além da menor susceptibilidade de degradação colagenolítica, por possuir ação biomodificadora. São necessários mais estudos que comprovem a eficiência de tais materiais como agentes condicionantes, assim como, a aplicabilidade clínica.Palavras-chave: Phytic Acid. Metaphosphoric Acid. Dentin.

A Eficácia Clínica da Técnica Úmida Etanólica em Restaurações de Resina Composta: Revisão de Literatura

O objetivo do presente estudo foi revisar a literatura a cerca da eficácia clínica na técnica úmida etanólica (TUE) em restaurações com resinas compostas. Foi realizada uma busca nas bases de dados PubMed, Bireme e Cochrane Library de artigos em inglês do período de 2007 a 2017, utilizando os seguintes descritores: Dentin, Dentin-Bonding Agents e Ethanol como estratégia de busca. Foram encontrados 101 artigos, dos quais apenas os ensaios clínicos foram selecionados, totalizando 6, mediante a relevância, sendo os demais artigos excluídos do presente estudo. A TUE consiste na substituição de água livre em dentina por solvente livre de água, etanol absoluto. A técnica simplificada consiste na aplicação de etanol absoluto por 1 minuto, previamente a aplicação do “Bond”, de adesivo convencional de 3 passos. A TUE tem se mostrado bastante promissora, pois vai haver a remoção de água presente     na dentina, através de desidratação química e um encolhimento das fibras colágenas permitindo que os monômeros hidrofóbicos penetrem mais facilmente em dentina, sem o uso de “primers”. Dessa forma, diminuirá a sorção dos monômeros, consequentemente a hidrólise e a degradação da interface de união restauração/adesivo, aumentando a longevidade da restauração. Entretanto quando se trata de estudos clínicos a sua eficácia ainda não é bem estabelecida, acredita-se que seja por ação da pressão pulpar. Dessa forma, são necessários mais estudos clínicos e um maior período de observação para avaliar a durabilidade clínicas de restaurações com essa técnica.Palavras-chave: Dentin. Dentin-Bonding. Agents. Ethanol.

A CUso do Glutaraldeído como Agente de Ligações Cruzadas em Restaurações Resinosas em Dentina: uma Revisão de Literatura

O objetivo do presente estudo foi revisar a literatura para descrever a influência do glutaraldeido (GA) como agente de ligações cruzadas em restaurações em restaurações resinosas em dentina. Revisou-se a literatura no período de 2007 a 2017, nas bases de dados Pubmed, Bireme e Science Direct, no idioma Inglês, com os seguintes descritores: Glutaral, Dentin e Crosslinking Reagents. Chegando-se ao total de 12 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 5 são estudos in vitro, 4 estudos clínicos e 3 são revisões de literatura, foram excluídos artigos que fugiam do objetivo do estudo e revisões de literatura, sendo utilizados 9 artigos para o presente estudo. O GA é um agente biomodificador de origem sintética que forma ligações covalentes entre dois grupos aminas de hidroxilisina, presente na molécula de colágeno, com seus grupos aldeídos a fim de formar composto piridíneo estável. Conferindo uma boa biomecânica a matriz de colágeno desnudo e irá atuar inibindo colagenases, aumentando a durabilidade da interface adesiva. O GA possui um caráter citotóxico e, por isso, deve ser usado de maneira correta e cuidadosa, a fim de se conseguir o melhor resultado possível no sistema de adesão. O GA é capaz de promover um satisfatório aumento na resistência da união do material restaurador com a dentina. Em ação conjunta com outras substâncias – por exemplo, a HEMA – o GA cria uma barreira em áreas mais profundas dos túbulos dentinários, abaixo da zona de fibras colágenas expostas, ratificando, assim, a eficácia desse agente biomodificador.Palavras-chave: Glutaral. Dentin. Crosslinking Reagents.

Influência do Uso de Diferentes Agentes Condicionantes Associados à Técnica Úmida Etanólica Sobre União à Dentina

O objetivo foi avaliar a resistência de união (RU) à microtração (μTBS) e o grau de conversão (GC) de diferentes agentes condicionantes associados à técnica úmida etanólica (TUE) sobre a união de um sistema restaurador adesivo à superfície dentinária e comparar os resultados com a técnica convencional (TC), de acordo com os grupos: ORTO-C – TC e ácido ortofosfórico a 37% META-C – TC e ácido metafosfórico a 40% FIT-C TC e ácido fítico a 2% ORTO-E – TUE e ácido ortofosfórico a 37% META-E – TUE e ácido metafosfórico a 40% FIT-E – TUE e ácido fítico a 2%. Quarenta e oito dentes foram restaurados em dentina média. Em seguida, trinta (n5) foram cortados em espécimes em formato de palito (área de secção transversal de 1mm²). Posteriormente, foi realizado o teste de microtração em máquina de ensaio universal. Dezoito dentes (n3) foram cortados em formato de discos para avaliação do GC em espectroscopia micro-Raman. Os dados foram submetidos à ANOVA dois fatores e teste de Tukey (p<0,05). O efeito dos diferentes agentes condicionantes vai depender da técnica adesiva utilizada (p0,004). Os grupos tratados com a TC não apresentaram diferença, já na TUE o FIT-E apresentou menor RU. Quando comparados os ácidos em diferentes técnicas, observou- se que o META apresentou melhores resultados de RU na TUE (25,72 ± 6,80 MPa), já o FIT mostrou-se melhor quando utilizado sem a TUE. Em relação ao GC, não houve diferença estatística entre os grupos (p0,658). Dessa forma, agentes condicionantes alternativos têm se tornado promissores, e juntamente com a TUE podem melhorar a adesão em dentina.Palavras-chave: Adesão. Técnica Úmida Etanólica. Agentes de Ligação Cruzada.

Agentes Naturais de Biomodificação Dentinária: uma Revisão da Literatura

O objetivo do presente trabalho foi revisar a literatura e avaliar os agentes naturais quanto ao seu potencial de biomodificação dentinária. Foi realizada uma busca nas bases de dados Pubmed, Bireme e Science Direct, entre 2007 e 2017, no idioma inglês, utilizando os descritores combinados “Cross-linking Reagentes”, “Dentin” e “Biological Products”. Foram obtidos 36 artigos, sendo 7 in vitro, 13 ensaios clínicos, 11 revisões de literatura e 5 casos clínicos. Artigos de revisão de literatura e caso clínico foram excluídos, através de uma leitura crítica dos títulos e dos resumos dos demais, foram selecionados 10, relevantes ao tema. Agentes naturais de biomodificação dentinária possuem baixa citotoxicidade se comparados aos sintéticos, como o glutaraldeído que é apontado como padrão ouro. A proantocianidina, proveniente da semente de uva, mostra um aumento da resistência de união e redução da atividade das metaloproteinases de matriz (MMP) e cisteína catepsinas (CC), além de baixo custo e fácil obtenção, em relação aos demais. Outros agentes estudados são a hesperidina, que apresentou evidências positivas ao diminuir a degradação da interface adesiva. Dentre as catequinas, a Epigalocatequina-3-galato apresentou-se eficaz como agente de ligação cruzada, além de diminuir a atividade colagenolítica da dentina subjacente à restauração, mostrando-se eficaz em preservar o colágeno desnudo. Apesar dos estudos apresentarem resultados promissores, são necessários mais estudos que comprovem a efetividade clínica desses agentes.Palavras-chave: Cross-Linking Reagentes. Dentin. Biological Products.

A Influência da Carboiimida na Durabilidade de Restaurações Resinosas no Substrato Dentinário: uma Revisão de Literatura

A Carbodiimida (EDC) é um agente biomodificador que forma ligações covalentes estáveis entre aminoácidos presentes no colágeno da dentina. O objetivo do presente estudo é revisar a literatura para avaliar a influência do EDC na durabilidade de restaurações resinosas em substrato dentinário. Para isso, foi realizada uma busca bibliográfica na qual foram selecionados artigos publicados no período de 2007 a 2017 nas bases de dados PubMed, Bireme e Science Direct, no idioma Inglês, utilizando os descritores: Cross-Linking Reagents, Dentin-Bonding Agents e Carbodiimides. Chegando-se ao total de 19 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 10 são estudos in vitro e 9 são revisões de literatura, sendo excluídos casos clínicos e artigos que fugiam do objetivo do estudo. Selecionou-se 10 artigos mediante a relevância ao tema. O EDC mostrou-se eficaz na formação de ligações cruzadas entre fibras colágenas melhorando a biomecânica da dentina, além disso, atua inibindo enzimas como as Metaloproteinases (MMPs), levando a uma diminuição da degradação dessas fibras que não foram impregnadas por monômeros após o condicionamento ácido desse substrato, aumentando a longevidade da restauração. Entretanto, os estudos que avaliam a atuação desse agente biomodificador foram realizados em um espaço de tempo muito curto. O desenvolvimento de estudos mais longos é fundamental para que a comunidade científica obtenha resultados concretos sobre a atuação do EDC.Palavras-chave: Cross-Linking Reagents. Dentin-Bonding Agents. Carbodiimides.

Avaliação de Propriedades Mecânicas De Resinas Microhíbridas Comerciais para Esmalte

O objetivo do presente estudo foi avaliar a microdureza Knoop, a resistência flexural e o módulo de elasticidade de compósitos microhíbridos para esmalte. Foram utilizadas três resinas comerciais: Empress Direct (Ivoclar Vivadent), Charisma (Kulzer) e NT Premium (Coltene). Para o teste de microdureza foram confeccionados corpos-de-prova (n6) para cada material testado, com uma matriz de silicona, medindo 5 mm de diâmetro e 2 mm de profundidade, fotopolimerizados por 40s, com o aparelho DB685 (Dabi Atlante) com irradiância de 1100 mW/cm². Foi utilizado microdurômetro Knoop com carga de 50 gf por 15 segundos em que cada corpo de prova recebeu 5 indentações, sendo calculada a média de cada espécime. Os testes de resistência flexural e módulo de elasticidade foram realizados em uma máquina de ensaio universal (Instron) com velocidade de carga de 1 mm/min com espécimes com formato de barra com dimensões 7mmx2mmx1mm. Os dados foram submetidos à ANOVA um fator e teste post-hoc de Tukey com nível de confiança de 95%. Os resultados mostraram que não houve diferença estatística significativa entre os grupos testados quanto à microdureza (p0,087) e módulo de elasticidade (p0,114). Contudo, verificou-se a existência de diferença estatisticamente significativa (p0,036) em relação à resistência flexural. A resina NT Premium apresentou maior resistência flexural, enquanto a IPS Empress Direct mostrou-se com menor valor. Em conclusão, as resinas avaliadas apresentaram propriedades mecânicas semelhantes, exceto a resistência à flexão em que a NT Premium foi melhor.Palavras-chave: Composite Resins. Microhybrid. Classification.

Estratégias para Melhorar a Durabilidade da Interface Adesiva: uma Revisão da Literatura

A integridade da interface adesivo-dentina constitui-se um desafio para a odontologia restauradora, sendo necessário o uso de estratégias que aumentem a longevidade das restaurações. O objetivo deste trabalho foi realizar uma revisão de literatura com artigos que abordassem estratégias para melhorar a durabilidade da interface adesiva e avaliar seus respectivos resultados. Foi realizada uma busca nas bases de dados Pubmed, Bireme e Scopus, entre 2007 e 2017, utilizando os descritores combinados dentin, collagen e longevity, considerando artigos em inglês e em português. Foram obtidos 60 artigos, sendo 45 in vitro, 10 revisões de literatura   e 5 revisões sistemáticas, desses 34 estavam repetidos e foram excluídos. Através de uma leitura crítica de títulos e resumos,  foram selecionados 18, relevantes ao tema. Artigos de revisão de literatura e que não se adequavam ao objetivo do trabalho foram excluídos. Os achados apontam desde técnicas aplicadas pelo operador no procedimento clínico aos novos agentes condicionantes, materiais incorporados aos sistemas adesivos ou utilizados como pré-tratamentos às restaurações. São relatados principalmente    os testes envolvendo inibidores de metaloproteinases de matriz, remineralização biomimética, adesão através da técnica úmida etanólica, o uso de substâncias que formam ligações cruzadas entre o colágeno dentinário e/ou com propriedades anticolagenolíticas. As pesquisas têm se mostrado promissoras, entretanto, são necessários mais estudos que comprovem a efetividade e viabilidade clínica de tais estratégias.Palavras-chave: Dentin. Collagen. Longevity.

Uso dos Oxalatos no Tratamento da Hipersensibilidade Dentinária: uma Revisão de Literatura

O objetivo deste estudo é avaliar a eficácia dos Oxalatos (OX) de cálcio e potássio no tratamento da hipersensibilidade dentinária. Revisou-se a literatura de artigos publicados no período de 2007 a 2017 nas bases de dados PubMed, Bireme e Science Direct,    no idioma Inglês, utilizando os seguintes descritores: Calcium Oxalate, Hypersensitivy e Dentin. Foram encontrados 16 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 14 são estudos in vitro, 1 estudo clínico e 1 revisão de literatura, sendo excluídos artigos que fugiam do objetivo do estudo. Selecionou-se 9 artigos mediante a relevância ao tema. A hipersensibilidade dentinária (HD) é caracterizada por uma dor transitória ocasionada quando dente é submetido a estímulos químicos, térmicos, tácteis e osmóticos. O oxalato de cálcio ou de potássio irá agir na terapêutica da HD, através da oclusão desses túbulos dentinários expostos, formando cristais insolúveis provenientes da reação do ácido oxálico com o cálcio ou potássio, podendo ligar-se a ânions presentes nas proteínas em dentina, dessa forma irá diminuir o fluxo dos fluidos entre o dente e o meio oral reduzindo a sintomatologia dolorosa. Porém as condições do meio oral influenciam na durabilidade, já que há uma penetrabilidade de apenas 2 a 3 micrômetros sendo resistentes ao desafio ácido. A dentina tratada com OX podem apresentar alterações na sua estrutura. Não há avaliações suficientes ao longo prazo, necessitando-se de mais investigações sobre novas formulações de pastas e géis a base de OX, além de mais estudos clínicos.Palavras-chave: Calcium Oxalate. Hypersensitivy.e Dentin.