Anti-N-methyl-d-aspartate receptor encephalitis in a pre-teenage girl: a case report

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is an auto-immune and paraneoplastic encephalitis which generally affects young adults. It is a multistage illness, with prominent extrapyramidal, neuropsychiatric and autonomic symptoms. The syndrome is frequently associated with an ovarian teratoma. Recently, it has become evident that anti-NMDAR encephalitis is more common in children and adolescents than was previously believed. Prognostic factors that determine a good outcome are presence of a tumour, prompt treatment and no need for admission to an intensive care unit. Increased awareness among paediatricians of this potentially life-threatening disease is important because early recognition and treatment will improve the patients’ chances of a good clinical outcome. In this case report, we describe a 9-year-old girl with behavioural changes and severe extrapyramidal symptoms due to anti-NMDAR encephalitis associated with an ovarian teratoma. She was treated with a variety of immunomodulating therapies and made a slow, but good recovery.     

Influence of bismuth oxide concentration on the pH level and biocompatibility of white Portland cement

Objectives

To investigate if there is a relation between the increase of bismuth oxide and the decrease of pH levels and an intensification of toxicity in the Portland cement.

Material and Methods

White Portland cement (WPC) was mixed with 0, 15, 20, 30 and 50% bismuth oxide, in weight. For the pH level test, polyethylene tubes were filled with the cements and immersed in Milli-Q water for 15, 30 and 60 days. After each period, the increase of the pH level was assessed. For the biocompatibility, two polyethylene tubes filled with the cements were implanted in ninety albino rats (n=6). The analysis of the intensity of the inflammatory infiltrate was performed after 15, 30 and 60 days. The statistical analysis was performed using the Kruskal-Wallis, Dunn and Friedman tests for the pH level and the Kruskal-Wallis and Dunn tests for the biological analysis (p<0.05).

Results

The results showed an increase of the pH level after 15 days, followed by a slight increase after 30 days and a decrease after 60 days. There were no significant statistical differences among the groups (p>0.05). For the inflammatory infiltrates, no significant statistical differences were found among the groups in each period (p>0.05). The 15% WPC showed a significant decrease of the inflammatory infiltrate from 15 to 30 and 60 days (p<0.05).

Conclusions

The addition of bismuth oxide into Portland cement did not affect the pH level and the biological response. The concentration of 15% of bismuth oxide resulted in significant reduction in inflammatory response in comparison with the other concentrations evaluated.     

Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization.

Objective

This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF₄ and NaF varnishes, with different concentrations, for 12 h.

Material and Methods

Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF₄ varnish (0.95% F, pH 1.0); 3.10% TiF₄ varnish (1.90% F, pH 1.0); 3.10% and 4% TiF₄ varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni''s test were applied for the statistical analysis (p<0.05).

Results

TiF₄ varnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF₄ varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva.

Conclusions

The 3.10% and 4% TiF₄ -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF₄ varnish on tooth surface.     

Erosive cola-based drinks affect the bonding to enamel surface: an in vitro study

Objective

This study aimed to assess the impact of in vitro erosion provoked by different cola-based drinks (Coke types), associated or not with toothbrushing, to bonding to enamel.

Material and Methods

Fifty-six bovine enamel specimens were prepared and randomly assigned into seven groups (N=8): C- Control (neither eroded nor abraded), ERO-RC: 3x/1-minute immersion in Regular Coke (RC), ERO-LC: 3x/1-minute immersion in Light Coke (LC), ERO-ZC: 3x/1-minute immersion in Zero Coke (ZC) and three other eroded groups, subsequently abraded for 1-minute toothbrushing (EROAB-RC, EROAB-LC and EROAB-ZC, respectively). After challenges, they were stored overnight in artificial saliva for a total of 24 hours and restored with Adper Single Bond 2/Filtek Z350. Buildup coronal surfaces were cut in 1 mm² -specimens and subjected to a microtensile test. Data were statistically analyzed by two-way ANOVA/Bonferroni tests (α=0.05). Failure modes were assessed by optical microscopy (X40). The interface of the restorations were observed using Confocal Laser Scanning Microscopy (CLSM).

Results

All tested cola-based drinks significantly reduced the bond strength, which was also observed in the analyses of interfaces. Toothbrushing did not have any impact on the bond strength. CLSM showed that except for Zero Coke, all eroded specimens resulted in irregular hybrid layer formation.

Conclusions

All cola-based drinks reduced the bond strength. Different patterns of hybrid layers were obtained revealing their impact, except for ZC.     

Simulations reveal that antimicrobial BP100 induces local membrane thinning,slows lipid dynamics and favors water penetration

BP100, a short antimicrobial peptide, produces membrane perturbations that depend on lipid structure and charge, salts presence, and peptide/lipid molar ratios. As membrane perturbation mechanisms are not fully understood, the atomic scale nature of peptide/membrane interactions requires a close-up view analysis. Molecular Dynamics (MD) simulations are valuable tools for describing molecular interactions at the atomic level. Here, we use MD simulations to investigate alterations in membrane properties consequent to BP100 binding to zwitterionic and anionic model membranes. We focused on membrane property changes upon peptide binding, namely membrane thickness, order parameters, surface curvature, lipid lateral diffusion and membrane hydration. In agreement with experimental results, our simulations showed that, when buried into the membrane, BP100 causes a decrease in lipid lateral diffusion and lipid acyl-chain order parameters and sharp local membrane thinning. These effects were most pronounced on the closest lipids in direct contact with the membrane-bound peptide. In DPPG and anionic-aggregate-containing DPPC/DPPG membranes, peptide flip (rotation of its non-polar facet towards the membrane interior) induced marked negative membrane curvature and enhanced the water residence half-life time in the lipid hydrophobic core and transmembrane water transport in the direction of the peptide. These results further elucidate the consequences of the initial interaction of cationic alpha-helical antimicrobial peptides with membranes.

MD simulations reveal that BP100 peptide induces local membrane thinning and negative curvature, slows lipid dynamics and increases the water life time in the lipid hydrophobic core and transmembrane water transport in the direction of the peptide.     

Estratégias Econômicas e Sociais para Anticoagulação de Pacientes com Fibrilação Atrial

Background:Atrial fibrillation is a public health problem associated with a fivefold increased risk of stroke or death. Analyzing costs is important when introducing new therapies and must be reconsidered in special situations, such as the novel coronavirus pandemic of 2020.Objective:This study aimed to evaluate the costs related to anticoagulant therapy in a one-year period, and the quality of life of atrial fibrillation patients treated in a public university hospital.Methods:Patient costs were those related to the anticoagulation and calculated by the average monthly costs of warfarin or direct oral anticoagulants (DOACs). Patient non-medical costs (eg., food and transportation) were calculated from data obtained by questionnaires. The Brazilian SF-6D was used to measure the quality of life. P-values < 0.05 were considered statistically significant.Results:The study population consisted of 90 patients, 45 in each arm (warfarin vs direct oral anticoagulants). Costs were 20% higher in the DOAC group ($55,532.62 vs $46,385.88), and mainly related to drug price ($23,497.16 vs $1,903.27). Hospital costs were higher in the warfarin group ($31,088.41 vs $24,604.74) and related to outpatient visits. Additionally, non-medical costs were almost twice higher in the warfarin group ($13,394.20 vs $7,430.72). Equivalence of price between the two drugs could be achieved by a 39% reduction in the price of DOACs. There were no significant group differences regarding quality of life.Conclusions:Total costs were higher in the group of patients taking DOACs than those taking warfarin. However, a nearly 40% reduction in the price of DOACs could make it feasible to incorporate these drugs into the Brazilian public health system.     

Risk factors for abdominal scar endometriosis after obstetric hysterotomies: a case-control study

OBJECTIVE: To identify risk factors that are associated with the development of scar endometriosis after obstetric hysterotomies. The hypothesis is that early hysterotomy in pregnancy (before 22nd week) is the main risk factor for the development of scar endometriosis. METHODS: The authors conducted a case-control study between April 2000 and June 2003. A total of 117 women were selected, including 39 cases and 78 controls. Exposure and confounding variables were measured by a standardized questionnaire, which included sociodemographic characteristics, reproductive/physiologic history, past pathological history, history of obstetric surgeries, family history, and social history. The odds ratio (OR) and its 95% confidence interval (CI) were calculated using bivariate analysis for each possible risk factor. These estimates were obtained by multivariate analysis using unconditional logistic regression. Tests were made to assess the fit of the final model. RESULTS: In the multivariate analysis, positive associations were observed between scar endometriosis and hysterotomy type (early versus late: OR = 42.99; CI 8.77-210.81), amount of the menstrual blood flow (heavy versus light/normal: OR = 11.97; CI 2.35-60.82), and alcoholic consumption (yes versus no: OR = 5.31; CI 1.22-23.11). Negative association was observed between scar endometriosis and parity (OR = 0.61; CI 0.31-1.23), however it was not statistically significant (p>0.05). CONCLUSIONS: Early hysterotomy in pregnancy is the main risk factor for scar endometriosis. Increased menstrual flow and alcohol consumption are also risk factors, while high parity may be a protecting factor.     

Establishment of tissue-specific tolerance is driven by regulatory T cells selected by thymic epithelium

Grafts of thymic epithelium (TE) rudiments restore T cell development and function in allogeneic athymic mice. These TE chimeras are specifically tolerant to grafts of peripheral tissues (e.g. skin and heart) from the TE donor strain, although they harbor peripheral immunocompetent T cells capable of rejecting those grafts. Initial analysis has shown that TE chimeras also harbor TE-selected CD4 T lymphocytes that inhibit graft rejection by tissue-reactive T cells in immunocompetent recipients. Peripheral tolerance in TE chimeras is thus maintained by dominant mechanisms dependent on regulatory CD4 T lymphocytes. Here we show that TE-selected regulatory T cells recruit nontolerant tissue-reactive CD4 and CD8 T cells to express similar regulatory functions. Only recent thymic emigrants, but not peripheral resident mature T cells are susceptible to this process of functional education, which also requires exposure to specific antigens and occurs entirely in the periphery. We propose that these mechanisms play a major role in establishing and maintaining natural self tolerance to tissue-specific antigens.