'Green' silver nanoparticles combined with tyrosol as potential oral antimicrobial therapy

OBJECTIVES

This study aimed to evaluate silver nanoparticles (AgNPs) obtained by a 'green' route associated or not to tyrosol (TYR) against Streptococcus mutans and Candida albicans in planktonic and biofilms states.

METHODS

AgNPs were obtained by a 'green' route using pomegranate extract. The minimum inhibitory concentration (MIC) against S. mutans and C. albicans was determined for AgNPs and TYR combined and alone, and fractional inhibitory concentration index (FICI) was calculated. Single biofilms of C. albicans and S. mutans were cultivated for 24 h and then treated with drugs alone or in combination for 24 h.

RESULTS

AgNPs and TYR were effective against C. albicans and S. mutans considering planktonic cells alone and combined. The MIC values obtained for C. albicans was 312.5 µg/mL (AgNPs) and 50 mM (TYR) and for S. mutans was 78.1 µg/mL (AgNPs) and 90 mM (TYR). The combination of these antimicrobial agents was also effective against both microorganisms: 2.44 µg/mL/0.08 mM (AgNPs/TYR) for C. albicans and 39.05 µg/mL /1.25 mM (AgNPs/TYR) for S. mutans. However, synergism was observed only for C. albicans (FICI 0.008). When biofilm was evaluated, a reduction of 4.62 log10 was observed for S. mutans biofilm cells treated with AgNPs (p < 0.05, Tukey test). However, the addition of TYR to AgNPs did not improve their action against biofilm cells (p > 0.05). AgNPs combined with TYR demonstrated a synergistic effect against C. albicans biofilms.

CONCLUSIONS

These findings suggest the potential use of AgNPs with or without TYR against C. albicans and S. mutans, important oral pathogens.

CLINICAL SIGNIFICANCE

AgNPs obtained by a 'green' route combined or not with TYR can be an alternative to develop several types of oral antimicrobial therapies and biomaterials.

Effect of dental bleaching on the microhardness and surface roughness of sealed composite resins

Objectives

The aim of this in vitro study was to evaluate the microhardness and surface roughness of composite resins before and after tooth bleaching procedures.

Materials and Methods

Sixty specimens were prepared of each composite resin (Filtek Supreme XT and Opallis), and BisCover LV surface sealant was applied to half of the specimens. Thirty enamel samples were obtained from the buccal and lingual surfaces of human molars for use as the control group. The surface roughness and microhardness were measured before and after bleaching procedures with 35% hydrogen peroxide or 16% carbamide (n = 10). Data were analyzed using 1-way analysis of variance and the Fisher test (α = 0.05).

Results

Neither hydrogen peroxide nor carbamide peroxide treatment significantly altered the hardness of the composite resins, regardless of surface sealant application; however, both treatments significantly decreased the hardness of the tooth samples (p < 0.05). The bleaching did not cause any change in surface roughness, with the exception of the unsealed Opallis composite resin and dental enamel, both of which displayed an increase in surface roughness after bleaching with carbamide peroxide (p < 0.05).

Conclusions

The microhardness and surface roughness of enamel and Opallis composite resin were influenced by bleaching procedures.

Overweight Risk and Food Habits in Portuguese Pre-school Children

The relationship between dietary intake and overweight-risk was assessed in 4349 children aged 3–5 years. Eating and sedentary behaviours were assessed by questionnaire. Logistic regressions were used. Children who consumed daily soft-drinks were 1.52 times more likely to be obese, and 72% more likely to be classified as overweight children.

Sodium trimetaphosphate and hexametaphosphate impregnated with silver nanoparticles: characteristics and antimicrobial efficacy

This study aimed to synthesize and characterize materials containing silver nanoparticles (AgNP) with polyphosphates (sodium trimetaphosphate (TMP) or sodium hexametaphosphate (HMP), and evaluate their effect against Candida albicans and Streptococcus mutans. The minimum inhibitory concentration (MIC) was determined, which was followed by the quantification of the biofilm by counting colony-forming units (CFUs), the amount of metabolic activity, and the total biomass. The MICs revealed greater effectiveness of composites containing 10% Ag (TMP + Ag10% (T10) and HMP + Ag10% (H10)) against both microorganisms. It was observed that T10 and H10 reduced the formation of biofilms by 56-76% for C. albicans and by 52-94% for S. mutans for total biomass and metabolic activity. These composites promoted significant log reductions in the number of CFUs, between 0.45-1.43 log₁₀ for C. albicans and 2.88-3.71 log₁₀ for S. mutans (p < .001). These composites demonstrated significant antimicrobial activity, especially against S. mutans, and may be considered a potential alternative for new dental materials.

Anaphylaxis in a food allergy outpatient department: one-year review

Summary

Background. Anaphylaxis is an acute, potentially fatal, multi-organ allergic reac-tion. Our aim was to characterize the population with food induced anaphylaxis followed over a one-year period. Methods. Retrospective analysis of clinical files of patients with food anaphylaxis observed in our food allergy consultation during 2016. Results. Sixty-two patients were included. In the pediatric group, the implicated allergens were cow's milk, egg and fish and in the adults' group, the commonest allergens were nuts and wheat. Allergy to shrimp affected equally children and adults. The most frequent symptoms were urticaria (85.5%), angioedema (64.5%) and dyspnea (62.9%). Cofactors were present in 32.6% of patients, mainly exercise. Asthma and/or rhinitis were the most frequent comorbidities. Conclusion. In accordance to other studies, milk and egg were the most implicated allergens in children. Anaphylaxis in adults reflects the Mediterranean sensitization pattern. Exercise was the most relevant cofactor.

Differential effects of the combination of tyrosol with chlorhexidine gluconate on oral biofilms

OBJECTIVE

This study assessed the effect of tyrosol and chlorhexidine gluconate in combination against Candida albicans, Candida glabrata, and Streptococcus mutans in the planktonic state or forming biofilms in vitro.

MATERIALS AND METHODS

Checkerboard assays were performed for determination of minimum inhibitory concentration. Biofilms were cultivated during 24 h on specimens of acrylic resin and hydroxyapatite and treated with the drugs alone or in combination twice a day for 1 min, during 3 days. The antibiofilm effect was determined by quantification of the metabolic activity and cultivable cells. The drug combination was also applied on C. albicans to investigate its action on the number of hyphae. Data were statistically examined by two-way ANOVA and Holm-Sidak test (P < 0.05).

RESULTS

The effect of drug combination on planktonic cells was classified as antagonistic for C. albicans and indifferent for the other strains. Also, the drugs were ineffective against the tested biofilms. However, the drug combination showed a synergistic effect in reducing the number of hyphae by C. albicans.

CONCLUSION

The combination of tyrosol with chlorhexidine gluconate was only effective in reducing the number of hyphae by C. albicans, a relevant virulence factor of this species.

Role of tyrosol on Candida albicans, Candida glabrata and Streptococcus mutans biofilms developed on different surfaces

PURPOSE

To assess the effect of tyrosol on the production of hydrolytic enzymes (by Candida biofilm cells) and acid (by Streptococcus mutans biofilms), as well as to quantify single and mixed biofilms of these species formed on acrylic resin (AR) and hydroxyapatite (HA).

METHODS

Candida and S. mutans biofilms were formed on AR and HA in the presence of tyrosol during 48 hours. Next, acid proteinase, phospholipase and hemolytic activities of Candida biofilm cells were determined, while acid production by S. mutans biofilms was assessed by pH determination. The effect of tyrosol on mature biofilms (96 hours) was evaluated through quantification of total biomass, metabolic activity, number of colony-forming units and composition of biofilms' extracellular matrix. Data were analyzed by one- and two-way ANOVA, followed by Tukey's and Holm-Sidak's tests (α = 0.05).

RESULTS

Treatments with tyrosol were not able to significantly reduce hydrolytic enzymes and acid production by Candida and S. mutans. Tyrosol only significantly reduced the metabolic activity of single biofilms of Candida species.

CLINICAL SIGNIFICANCE

Tyrosol on its own had a limited efficacy against single and mixed-species oral biofilms. Its use as an alternative antimicrobial for topical therapies still demands more investigation.

Overweight parents are twice as likely to underestimate the weight of their teenage children, regardless of their sociodemographic characteristics

AIM

It is unclear whether parents' weight affects their ability to recognise whether their teenage children are overweight. This study analysed whether overweight parents assessed their child's weight as well as normal weight parents.

METHODS

This cross-sectional study was carried out in Londrina, Brazil, in 2011 and included teenagers between 14 and 17 years of age and their parents or guardians. We recorded the weight and height of the teenagers and asked the parents or guardians to fill in a questionnaire that included how they perceived their child's weight and demographic information.

RESULTS

We studied 1231 teenagers - 58.2% girls - and 19.4% were overweight or obese. In 842 (68.4%) of cases both parents replied to the questionnaire. We found that 8.7% of the 1202 mothers and 10.0% of the 871 fathers underestimated how overweight their child was. The adjusted analyses confirmed they were twice as likely to underestimate their child's weight if they were overweight themselves, with an odds ratio of 1.96 for the mothers and 2.04 for the fathers. Sociodemographic characteristics did not affect the results.

CONCLUSION

Overweight parents were twice as likely to underestimate the weight of their teenage children, regardless of the sociodemographic characteristics.

Arterial Thickness and Immunometabolism: The Mediating role of Chronic Exercise

Metabolic alterations and cardiovascular diseases, such as atherosclerosis, are associated with lifestyle modifications, particularly the increase of physical inactivity and poor eating habits, which contribute to one of the main causes of death in modern times. Cardiovascular diseases are positively correlated with several illnesses, such as obesity, hypertension and dyslipidemia, and these disorders are known to contribute to changes in immune cells, cytokines and metabolism. Atherosclerosis is a chronic inflammatory disease characterized by the formation of lipid plaques and fibrous tissue (atheroma) in the artery walls and this process is related to the oxidation of LDL-c (low density lipoprotein) and the formation of a particle, termed LDLox, which can generate toxic injury to the vessel wall. In this atherogenic process there is an inflammatory response generated by the injury in the vascular endothelium, which in itself is able to express and secrete a variety of molecules, such as myeloid colony-stimulating factors (M-CSF), monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor alpha (TNF-α), that act as activators of the immune system. Therefore, the main purpose of this review is to highlight the immuno-metabolic alterations involving the thickening and stiffness of arteries observed in atherosclerosis, and how chronic exercise can act as an anti-inflammatory and anti-atherogenic approach.

Activity of tyrosol against single and mixed-species oral biofilms

AIM

This study aimed to evaluate the effect of tyrosol on the formation of single and mixed biofilms of Candida albicans ATCC 10231, Candida glabrata ATCC 90030 and Streptococcus mutans ATCC 25175 formed on acrylic resin (AR) and hydroxyapatite (HA) surfaces.

METHODS AND RESULTS

Single and mixed biofilms were formed on AR and HA in the presence of tyrosol at 50, 100 and 200 mmol l(-1), during 48 h. Next, antimicrobial activity was assessed through metabolic activity (XTT reduction assay) and the number of colony-forming units (CFUs). Scanning electron microscopy observations were performed in order to analyse biofilm structure. Tyrosol, mainly at 200 mmol l(-1), significantly decreased the metabolic activity and number of CFUs for all single and mixed-species biofilms formed on both surfaces. SEM images suggested cell damage caused by tyrosol.

CONCLUSION

Tyrosol showed inhibitory effects against biofilms formed by important oral pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study showing the antibiofilm effect of tyrosol on Candida species and Strep. mutans in single and mixed cultures. These results may be useful in the development of topical therapies focused on preventing biofilm-associated oral diseases, such as denture stomatitis and dental caries.

Biofilm formation by Candida albicans and Streptococcus mutans in the presence of farnesol: a quantitative evaluation

The aim of this study was to evaluate the effect of the QS molecule farnesol on single and mixed species biofilms formed by Candida albicans and Streptococcus mutans. The anti-biofilm effect of farnesol was assessed through total biomass quantification, counting of colony forming units (CFUs) and evaluation of metabolic activity. Biofilms were also analyzed by scanning electron microscopy (SEM). It was observed that farnesol reduced the formation of single and mixed biofilms, with significant reductions of 37% to 90% and 64% to 96%, respectively, for total biomass and metabolic activity. Regarding cell viability, farnesol treatment promoted significant log reductions in the number of CFUs, ie 1.3-4.2 log10 and 0.67-5.32 log10, respectively, for single and mixed species biofilms. SEM images confirmed these results, showing decreases in the number of cells in all biofilms. In conclusion, these findings highlight the role of farnesol as an alternative agent with the potential to reduce the formation of pathogenic biofilms.

The relationship between inflammation, dyslipidemia and physical exercise: from the epidemiological to molecular approach

Dyslipidemia and inflammation are frequently found in some diseases, such as obesity, type 2 diabetes mellitus, and cancer cachexia. Recent literature has identified that lipids have a pivotal role in the activation of inflammatory pathways, increasing the production of inflammatory cytokines, mainly tumor necrosis factor alpha, interleukin 6 and 1β. On the other hand, cytokines can promote disruption of lipid metabolism, in special cholesterol reverse transport, which is linked to development of atherosclerosis. With this in mind, acute and chronic exercise trainings have been pointed as important tools to counteract both dyslipidemia symptoms and systemic inflammation. Moreover, physical activity has been recommended in the prevention/treatment of the above mentioned outcomes by important health organizations around the world, mainly because it costs less and generates fewer side effects than isolated medicine. Despite the well-documented capacity of acute and chronic exercise training to counteract sustained disease-related immunometabolism, we have chosen to take a look from a current perspective in molecular pathways and in the field of epidemiology. The aim of the present review was therefore to discuss the results of dyslipidemia and inflammatory conditions with acute and chronic exercise training, which underlies the field of molecular pathways and epidemiology. The mechanisms underlying the response to the treatment are considered.

Derivation and characterization of progenitor stem cells from canine allantois and amniotic fluids at the third trimester of gestation

Fetal tissues are frequently discarded before (amniocentesis) or after birth, which both facilitates stem cell access and helps to overcome ethical concerns. In the present study, we aimed to isolate and characterize stem cells from the allantoic and amniotic fluids (ALF; AMF) of third trimester canine fetuses. This gestation age has not been previously explored for stem cells isolation. The gestational age, cell culture conditions and method of isolation used in this study allowed for the establishment and efficient expansion of ALF and AMF cells. We showed that the majority of ALF and ALF cells express the stem cell markers, such as vimentin, nestin and cytokeratin 18 (CK18). Under appropriate culture conditions AMF derived cells can undergo differentiation into osteogenic, adipogenic, chondrogenic and neuron-like lineages. ALF derived cells showed adipogenic, and chondrogenic potential. Therefore, ALF and AMF cells derived at the third gestation trimester can be qualified as progenitor stem cells, accordingly referred as (alantoic fluid progenitor/stem) ALF PS cells and (amniotic fluid progenitor/stem) AMF PS cells.

Viability of mesenchymal stem cells during electrospinning

Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10% polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6% and the viability of mononuclear cells from 99 to 8.38%. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage.

Physical activity is inversely associated with high blood pressure independently of overweight in Brazilian adolescents

The purpose of this study was to assess the relationship between blood pressure (BP) levels and physical activity (PA) domains accounting for overweight/obesity. Adolescents aged 10 to 17 years old were recruited (n = 1021). International Obesity Task Force (IOTF) criteria were used to define overweight and obesity. High BP was defined using the Center of Disease Control and Prevention criteria. Different domains of PA (school activities, sport out of school, and leisure time PA) were assessed using a validated questionnaire. The prevalence of overweight/obesity was 21.9% for boys and 14.8% for girls. Some 13.4% of boys and 10.2% of girls, respectively, had high blood pressure (HBP). A strong and positive association was found between overweight and HBP. After adjustment for body mass index (BMI), total PA was inversely associated with BP. When all PA domains were entered simultaneously in a regression model, and after adjustment for BMI, only sport out of school was significantly and inversely associated with systolic BP [β: -0.82 (-1.50; -0.13)]. These findings open avenue for the early prevention of HBP by the prevention of obesity and promotion of PA.

Health care resource use and costs in opioid-treated patients with and without constipation in Brazil

OBJECTIVE

To estimate the prevalence of constipation concomitant to opioid treatment and related resource use and costs from the private payer perspective.

METHODS

In this retrospective database analysis, patients receiving opioid therapy were identified from a longitudinal insurance claims database. An algorithm was used to identify patients receiving opioid therapy with coincident constipation-related claims according to ICD-10 codes, targeted procedures, and opioid use criteria. Resource use and costs were determined for these individuals and compared with patients receiving opioid therapy without constipation, without opioid therapy with constipation, and without both conditions. Results were compared using analysis of variance with a significance level of 0.05.

RESULTS

A total of 23,313 patients were classified as opioid-treated patients (2.2%) and 6678 of them had events related to constipation (29.0%). Compared with opioid-treated patients without constipation, incremental mean total costs per month per patient were 261.18 BRL (P < 0.001). The average cost per month for opioid-related constipation patients was 787.84 BRL, significantly higher than other patients (P < 0.001 for all comparisons). Among cancer patients, 24.4% was receiving opioids and 27.0% of those had constipation-related claims. As expected, the opioid therapy prevalence was significantly higher when compared to all patients (2.2% vs. 24.4%, P < 0.001). Cancer patients had, in average, higher costs than did noncancer patients in all four subgroups.

CONCLUSIONS

Patients with constipation coincident with opioid treatment exhibited a significantly higher economic burden than did patients without the condition. These results indicate that reducing opioid-induced constipation could lead to potential cost savings for the health care system.

Ectopic placement of Sengstaken-Blakemore device to correct outflow obstruction in liver transplantation: case reports

Liver transplantation is a complex procedure that has become the treatment for some end-stage liver diseases. Some technical features are important for the success of the transplantation, including the patency of the vascular anastomoses. In cadaveric whole organ liver transplantation, a large right subphrenic space may contribute to a twist of the inferior vena cava, leading to outflow obstruction, simulating an acute Budd-Chiari syndrome. Some devices can be used to correct this drainage problem. Herein, we have described 2 cases in which the Sengstaken-Blakemore balloon was safely used, in an ectopic position, to fix drainage complications in whole liver orthotopic transplantation.

[Mortality risk measure inequalities among workers in Southeast Brazil]

INTRODUCTION

The main causes of illness and death in Brazil have been migrating backwards into the younger population during the last few years, increasing especially in the more productive age groups. Given the relationship between work and health/disease process, the hypothesis to be considered is that this phenomenon is partially due to the deterioration of workplace conditions. To contribute to investigating this hypothesis, this study estimates mortality risk indicators for the population of Botucatu, in the Southeast region of Brazil, classified according to their occupation.

METHODS

Standardized mortality coefficient, standardized risk ratio, and years of potential life lost were calculated for the inhabitants of Botucatu who died after their 10th birthday, between January 1997 and March 1998, and classified according to their occupation and main cause of death. Occupational and medical information was obtained by interviewing families of the deceased and their doctors, and checking medical files.

RESULTS

The standardized mortality coefficient ranged from 0.6 to 39.9 deaths/1000 workers in different occupations. The years of potential life lost ranged form 33 to 334 years/1000 workers. The ranking of causes of death varied according to occupation and the mortality risk considered.

CONCLUSION

The risk measures analyzed showed a high heterogeneity when associated to occupation and causes of death, which reflects the great social inequality existing in the studied population.

[Validity of information on occupation and principal cause on death certificates in Botucatu, Sao Paulo]

The aim of this paper was to evaluate the accuracy of data on death certificates for occupation and main cause of death. Measure of agreement was assessed comparing data from death certificates with those from both medical records and next-of-kin interviews, analyzing information for 552 residents of Botucatu, Southeast Brazil, who died in 1997. Kappa coefficients of 0.31 (95% C.I. 0. 29-0.34) and 0.76 (95% C.I. 0.75-0.76) were obtained for data on occupation and main cause of death, coded by a Brazilian two-digit classification and the three-digit ICD-10 classification, respectively. One can conclude that, although quality of the main cause of death is acceptable for pilot studies, data on occupation taken only from death certificates is not accurate enough to be used in epidemiological research.

Low socioeconomic status is a strong independent predictor of relapse in childhood acute lymphoblastic leukemia

The results of the treatment of acute lymphoblastic leukemia (ALL) in children depend not only on the biologic diversity of the leukemia cell, the multi-drug treatment schedule and the individual variability of drug metabolism, but also on the socioeconomic and cultural background of the leukemic child. Social and cultural disparity is very marked in underdeveloped countries and has been increasing in industrialized nations. The prognostic influences of these factors are poorly documented and sometimes mistakenly attributed to differences in ethnic origin. We have investigated in Brazil the relative impact of malnutrition and socioeconomic status on the outcome of ALL, adjusting for the known influence of biologic factors. Children with ALL (n = 167) treated with a Berlin-Frankfurt-Munster-based protocol were studied prospectively. At a median follow-up of 1623 days, the estimated probability of disease-free survival was 43 +/- 4%. The main cause for interruption of remission was bone-marrow relapse. Socioeconomic indicators of poverty (poor housing conditions, low per capita income and energy consumption) were significantly associated with a greater risk of relapse in univariate analysis. They were consolidated in a single index, socioeconomic status (SES), defined by the product of monthly per capita income times mean familial daily energy consumption. Other unfavorable findings included age, z score for the height for age at diagnosis (HAZ) below-1.28 and the z score for weight for age below-1.28. After adjustment in Cox's multivariate model, only HAZ and poor SES remained as predictive factors for relapse. Poor prognosis for leukemic children of low SES is just another indicator of social inequality.

[Giant hemangioma treated with interferon alpha-2a]

OBJECTIVE

The authors describe a case of giant hemangioma treated with interferon alpha-2a and review the role of this drug and other therapeutic modalities in the management of vascular lesions.

METHODS

A seven month-old child with giant hemangioma and persistent bleeding, anemia and repeated infections was treated with interferon alpha-2a. The drug was administered at the dosage of 3 million units/m(2)/day, subcutaneously, for nine months.

RESULTS

Response to treatment was considered excellent, with regression of 90% of the lesion, control of bleeding, infection and anemia, and catch-up growth. No untoward effects were observed.

CONCLUSION

Interferon alpha-2a should be considered as a valid therapeutic option in selected cases of hemangioma in children.

[Modality of support for research in the field of nursing]

This paper deals with the organization of the Operational Research Committee implemented at the University Hospital of the University of Säo Paulo in 1993 with the objective of giving logistic support to nurses in the development of their scientific work. It shows the strategies adopted to encouage research among nurses to reach the success of the proposal.