Blockade of proteinase-activated receptor 4 inhibits neutrophil recruitment in experimental inflammation in mice

Objective and design

The activation of proteinase-activated receptors (PARs) has been implicated in the development of important hallmarks of inflammation, including in vivo leukocyte recruitment; however, its role in the regulation of leukocyte migration in response to inflammatory stimuli has not been elucidated until now. Here, we examined the effects of the PAR4 antagonist YPGKF-NH 2 (tcY-NH₂) on neutrophil recruitment in experimentally induced inflammation.

Methods

BALB/c mice were intrapleurally injected with tcY-NH₂ (40 ng/kg) prior to intrapleural injection of carrageenan (Cg) or neutrophil chemoattractant CXCL8; the number of infiltrating neutrophils was evaluated after 4 h, and KC production was assessed at different times after Cg injection. Neutrophil adhesion and rolling cells were studied using a brain circulation preparation 4 h after the Cg or CXCL8 challenge in tcY-NH₂-treated mice.

Results

PAR4 blockade inhibited CXCL8- and Cg-induced neutrophil migration into the pleural cavity of BALB/c mice and reduced neutrophil rolling and adherence. Surprisingly, PAR4 blockade increased the level of KC in response to carrageenan.

Conclusion

These results demonstrated that PAR4 blockade impairs neutrophil migration in vivo, suggesting that PAR4 plays an important role in the regulation of inflammation, at least in part because of its ability to inhibit the actions of the neutrophil chemoattractant CXCL8.     

Undergraduate dentistry students’ perception of difficulties regarding endodontic treatment

The present study aimed to identify students’ perceptions of endodontic treatment at a Brazilian university through a survey, which analysed student profiles and their difficulties in 2016. One hundred and two students who had experienced endodontic, laboratory or clinical procedures answered a survey based on their experiences, regarding their perceptions, experience and self‐confidence levels. Results demonstrated that there was no significant difficulty among students regarding anaesthesia, rubber dam use, chamber access, working length determination, instrumentation, root filling and temporary restoration procedures during endodontic treatment. However, problems were observed regarding radiographic examination (mainly in separating root canals) and the choice of intracanal medication. The present study also raised a question regarding dental education: how can endodontic education be improved by addressing students' perceived difficulties? Evaluating the major student difficulties during root canal therapy can help the improvement of teaching strategies during preclinical and clinical teaching.     

Resistance Exercise Restores Endothelial Function and Reduces Blood Pressure in Type 1 Diabetic Rats

Background

Resistance exercise effects on cardiovascular parameters are not consistent.

Objectives

The effects of resistance exercise on changes in blood glucose, blood pressure and vascular reactivity were evaluated in diabetic rats.

Methods

Wistar rats were divided into three groups: control group (n = 8); sedentary diabetic (n = 8); and trained diabetic (n = 8). Resistance exercise was carried out in a squat device for rats and consisted of three sets of ten repetitions with an intensity of 50%, three times per week, for eight weeks. Changes in vascular reactivity were evaluated in superior mesenteric artery rings.

Results

A significant reduction in the maximum response of acetylcholine-induced relaxation was observed in the sedentary diabetic group (78.1 ± 2%) and an increase in the trained diabetic group (95 ± 3%) without changing potency. In the presence of NG-nitro-L-arginine methyl ester, the acetylcholine-induced relaxation was significantly reduced in the control and trained diabetic groups, but not in the sedentary diabetic group. Furthermore, a significant increase (p < 0.05) in mean arterial blood pressure was observed in the sedentary diabetic group (104.9 ± 5 to 126.7 ± 5 mmHg) as compared to that in the control group. However, the trained diabetic group showed a significant decrease (p < 0.05) in the mean arterial blood pressure levels (126.7 ± 5 to 105.1 ± 4 mmHg) as compared to the sedentary diabetic group.

Conclusions

Resistance exercise could restore endothelial function and prevent an increase in arterial blood pressure in type 1 diabetic rats.     

Salivary shedding of Epstein–Barr virus and cytomegalovirus in people infected or not by human immunodeficiency virus 1

The purpose of this study is to determine the frequency of EBV and CMV DNA detection in saliva of HIV infected and non-HIV individuals and their siblings. The study group comprised 240 individuals. Group 1 comprised of 40 HIV-infected patients, group 2 40 non-HIV individuals, group 3 two siblings for each patient from group 1 (n = 80), and group 4 two siblings for each individual from group 2 (n = 80). Non-stimulated whole saliva was collected, DNA was extracted, and amplification was performed using a nested PCR protocol. EBV and CMV DNA was detected in 7/40 (17.5%) and 5/40 (12.5%) individuals from group 1, 8/40 (20%) and 3/40 (7.5%) from group 2, 11/80 (13.8%) and 2/80 (2.5%) from group 3, and 8/80 (10%) and 1/80 (1.3%) from group 4, respectively. Five (71.4%) out of seven HIV/EBV coinfected individuals of group 1 had a relative also infected with EBV (OR = 11.25, CI [1.75–72.5], p = 0.011). Regarding group 2, among the eight non-HIV and EBV-infected individuals, three (37.5%) had a relative also positive to EBV (p = 0.320). No individual HIV/CMV coinfected had a relative CMV infected (p = 1.00). Also, only one non-HIV and CMV-infected individual had a relative also positive to CMV (p = 0.075). EBV and CMV DNA was detected mainly in those who had HIV viral load counts <400/mL (71%, p = 0.2 and 100%, p = 1, respectively) and those who had CD4 T cells counts between 200 and 400/mm³ (57%, p = 0.544 and 60%, p = 0.249, respectively). HIV-infected individuals and healthy controls showed a similar frequency of viral DNA detection. EBV DNA was significantly amplified in saliva of household members of HIV/EBV coinfected individuals.     

Sealability of MTA and calcium hydroxidecontaining sealers

Objectives

The aim of this study was to evaluate the apical sealability of Fillapex^®, Endo-CPM-Sealer^® and Sealapex^®.

Material and Methods

Ninety-four freshly extracted single-rooted teeth were selected and decoronated. All teeth were radiographed to confirm the existence of a single and straight root canal, which was prepared using Protaper Universal and 2.5% sodium hypochlorite. The teeth were randomly divided in groups of 10 specimens each according to the sealer, and the canals were filled using the single cone technique and one of the sealers. Four additional teeth were used as controls. The teeth were submitted to dye leakage with Rhodamine B for 24 h but using vacuum on the initial 15 min. Thereafter, they were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey''s tests at 5% significance level.

Results

Fillapex^® and Sealapex^® showed significantly less dye leakage than Endo-CPM-Sealer^® (p<0.05).

Conclusions

It was concluded that Fillapex^® and Sealapex^® were able to prevent apical dye leakage differently from Endo-CPM-Sealer^®.     

Unbiased plasma proteomics for novel diagnostic biomarkers in cardiovascular disease: identification of quiescin Q6 as a candidate biomarker of acutely decompensated heart failure

Aims Biochemical marker testing has improved the evaluation and management of patients with cardiovascular diseases over the past decade. Natriuretic peptides (NPs), used in clinical practice to assess cardiac dysfunction, exhibit many limitations, however. We used an unbiased proteomics approach for the discovery of novel diagnostic plasma biomarkers of heart failure (HF). Methods and results A proteomics pipeline adapted for very low-abundant plasma proteins was applied to clinical samples from patients admitted with acute decompensated HF (ADHF). Quiescin Q6 (QSOX1), a protein involved in the formation of disulfide bridges, emerged as the best performing marker for ADHF (with an area under the receiver operator characteristic curve of 0.86, 95% confidence interval: 0.79-0.92), and novel isoforms of NPs were also identified. Diagnostic performance of QSOX1 for ADHF was confirmed in 267 prospectively collected subjects of whom 76 had ADHF. Combining QSOX1 to B-type NP (BNP) significantly improved diagnostic accuracy for ADHF by particularly improving specificity. Using thoracic aortic constriction in rats, QSOX1 was specifically induced within both left atria and ventricles at the time of HF onset. Conclusion The novel biomarker QSOX1 accurately identifies ADHF, particularly when combined with BNP. Through both clinical and experimental studies we provide lines of evidence for a link between ADHF and cardiovascular production of QSOX1.     

Hydroxychloroquine decreases Th17-related cytokines in systemic lupus erythematosus and rheumatoid arthritis patients

OBJECTIVES:

Hydroxychloroquine is an antimalarial agent that has been used in systemic lupus erythematosus and rheumatoid arthritis treatment for many years. Recently, novel mechanisms of action have been proposed, thereby broadening the therapeutic perspective of this medication. The purpose of this study was to evaluate the immunomodulatory activity of hydroxychloroquine in T helper 17 (Th17) cytokines in healthy individuals and patients.

METHODS:

Eighteen female patients with systemic lupus erythematosus (mean age 39.0±12.9 years) and 13 female patients with rheumatoid arthritis (mean age 51.5±7.7 years) were recruited from Universidade Federal de Pernambuco-Brazil. The patients were included after fulfilling four classification criteria for systemic lupus erythematosus or rheumatoid arthritis from the American College of Rheumatology. After being stimulated with phorbol 12-myristate 13-acetate and ionomycin in the absence or presence of different concentrations of hydroxychloroquine, the interleukin 6, 17 and 22 levels were quantified with an enzyme-linked immunosorbent assay in culture supernatants of peripheral blood mononuclear cells from healthy individuals and patients.

RESULTS:

We demonstrated that in peripheral blood mononuclear cells from healthy volunteers and in systemic lupus erythematosus and rheumatoid arthritis patients, there was a significant reduction in the IL-6, IL-17 and IL-22 supernatant levels after adding hydroxychloroquine.

CONCLUSIONS

Our in vitro results demonstrated that hydroxychloroquine inhibits IL-6, IL-17 and IL-22 production and contributes to a better understanding of the mechanism of action of this medication.