Effectiveness of a reciprocating single file, single cone endodontic treatment approach: a randomized controlled pragmatic clinical trial.

OBJECTIVES: To compare the root filling quality, the sealer extrusion, and the healing rates of apical lesions addressed via two endodontic treatment approaches. The hypothesis tested was that both techniques present similar apical periodontitis healing results. MATERIALS AND METHODS: This study was a parallel-design, pragmatic, and randomized clinical trial. One hundred twenty anterior teeth with necrotic pulps and apical periodontitis were randomly allocated to be either instrumented with hand files and obturated with the lateral compaction technique or instrumented with a single file in a reciprocating movement and obturated with a single-cone technique. The root canal filling quality, the occurrence of sealer extrusion, and apical periodontitis healing were the outcomes of interest. Data were analyzed through chi-square analysis, and the odds ratio for healing was adjusted using a logistic regression model (α = 0.05). RESULTS: No significant differences were observed between the endodontic techniques regarding the root filling quality or sealer extrusion. Six months after treatment, both endodontic techniques presented equivalent results regarding apical periodontitis healing. The healing rate was affected only by the periapical status at baseline. CONCLUSIONS: The obturation of the root canal of the anterior teeth using reciprocating file-matched single cones presented a similar quality to that obtained with manual instrumentation followed by the lateral condensation technique. Similar healing rates of apical lesions were also observed. CLINICAL RELEVANCE: For treating anterior teeth with apical periodontitis, a reciprocating single-file, single-treatment protocol was as effective as a traditional protocol combining hand instrumentation and the lateral compaction obturation technique.

Recurrent wheezing in preterm infants: Prevalence and risk factors / Sibilância recorrente em prematuros: prevalência e fatores de risco

ABSTRACT Objective: To evaluate the prevalence and risk factors associated with progression to recurrent wheezing in preterm infants. Methods: The cross-sectional study was carried out in 2014 and 2015 and analyzed preterm infants born between 2011 and 2012. The search for these children was performed in a university maternity hospital and a Special Immunobiological Reference Center. The evaluation was performed through a questionnaire applied during a telephone interview. Results: The study included 445 children aged 39 (18-54) months. In the univariate analysis, the risk factors with the greatest chance of recurrent wheezing were birth weight <1000 g, gestational age <28 weeks, living with two or more siblings, food allergy, and atopic dermatitis in the child, as well as food allergy and asthma in the parents. In the multivariate analysis, there was a significant association between recurrent wheezing and gestational age at birth <28 weeks, food allergy and atopic dermatitis in the child, and living with two or more children. Of the 445 analyzed subjects, 194 received passive immunization against the respiratory syncytial virus, and 251 preterm infants were not immunized. There was a difference between the gestational age of these subgroups (p < 0.001). The overall prevalence of recurrent wheezing was 27.4% (95% CI: 23.42-31.70), whereas in the children who received passive immunization it was 36.1% (95% CI: 29.55-43.03). Conclusions: Personal history of atopy, lower gestational age, and living with two or more children had a significant association with recurrent wheezing. Children with lower gestational age who received passive immunization against the respiratory syncytial virus had a higher prevalence of recurrent wheezing than the group with higher gestational age.

RESUMO Objetivo: Avaliar a prevalência e os fatores de risco associados à evolução para sibilância recorrente em prematuros. Métodos: O estudo transversal foi feito em 2014 e 2015 e analisou crianças prematuras nascidas entre 2011 e 2012. A busca dessas crianças foi feita em maternidade de hospital universitário e em um Centro de Referência para Imunobiológicos Especiais. A avaliação foi feita por questionário dirigido em entrevista telefônica. Resultados: O estudo incluiu 445 crianças com 39 (18-54) meses de vida. Na análise univariada, os fatores de risco com maior chance de sibilância recorrente foram peso de nascimento menor do que 1.000 g, idade gestacional menor do que 28 semanas, convivência com dois ou mais irmãos, alergia alimentar e dermatite atópica na criança e alergia alimentar e asma nos pais. Na análise multivariada houve associação significativa entre sibilância recorrente e idade gestacional ao nascer menor do que 28 semanas, alergia alimentar e dermatite atópica na criança e a convivência com duas ou mais crianças. Dos 445 sujeitos analisados, 194 receberam imunização passiva contra vírus sincicial respiratório e 251 eram prematuros não imunizados. Houve diferença entre a idade gestacional desses subgrupos (p < 0,001). A prevalência geral de sibilância recorrente foi 27,4% (IC 95%: 23,42-31,70) e nas crianças que receberam a imunização passiva foi 36,1% (IC 95%: 29,55-43,03). Conclusões: História pessoal de atopia, menor idade gestacional e convivência com duas ou mais crianças apresentaram associação significativa com sibilância recorrente. As crianças com menor idade gestacional, que receberam a imunização passiva contra o vírus sincicial respiratório, apresentaram maior prevalência de sibilância recorrente que o grupo de maior idade gestacional.

Evaluation of respiratory dynamics by volumetric capnography during submaximal exercise protocol of six minutes on treadmill in cystic fibrosis patients / Avaliação da dinâmica respiratória por capnografia volumétrica durante o protocolo de exercício submáximo por seis minutos em esteira em pacientes com fibrose cística

Abstract Objectives: Volumetric capnography provides the standard CO2 elimination by the volume expired per respiratory cycle and is a measure to assess pulmonary involvement. Thus, the objective of this study was to evaluate the respiratory dynamics of healthy control subjects and those with cystic fibrosis in a submaximal exercise protocol for six minutes on the treadmill, using volumetric capnography parameters (slope 3 [Slp3], Slp3/tidal volume [Slp3/TV], and slope 2 [Slp2]). Methods: This was a cross-sectional study with 128 subjects (cystic fibrosis, 64 subjects; controls, 64 subjects]. Participants underwent volumetric capnography before, during, and after six minutes on the treadmill. Statistical analysis was performed using the Friedman, Mann-Whitney, and Kruskal-Wallis tests, considering age and sex. An alpha = 0.05 was considered. Results: Six minutes on the treadmill evaluation: in cystic fibrosis, volumetric capnography parameters were different before, during, and after six minutes on the treadmill; the same was observed for the controls, except for Slp2. Regarding age, an Slp3 difference was observed in cystic fibrosis patients regardless of age, at all moments, and in controls for age ≥ 12 years; a difference in Slp3/TV was observed in cystic fibrosis and controls, regardless of age; and an Slp2 difference in the cystic fibrosis, regardless of age. Regarding sex, Slp3 and Slp3/TV differences were observed in cystic fibrosis regardless of sex, and in controls in male participants; an Slp2 difference was observed in the cystic fibrosis and female participants. The analysis between groups (cystic fibrosis and controls) indicated that Slp3 and Slp3/TV has identified the CF, regardless of age and sex, while the Slp2 showed the CF considering age. Conclusions: Cystic fibrosis showed greater values of the parameters before, during, and after exercise, even when stratified by age and sex, which may indicate ventilation inhomogeneity in the peripheral pathways in the cystic fibrosis.

Resumo Objetivos: A capnografia volumétrica fornece o padrão de eliminação do CO2, pelo volume expirado por ciclo respiratório e avalia o comprometimento pulmonar. O objetivo do estudo foi avaliar a dinâmica respiratória de indivíduos controles saudáveis e em indivíduos com fibrose cística, em um protocolo de exercício submáximo por seis minutos em esteira, por parâmetros da capnografia volumétrica [slope 3(Slp3), Slp3/volume corrente (Slp3/TV) e slope 2(Slp2)]. Métodos: Estudo de corte transversal com 128 indivíduos [(fibrose cística) 64 indivíduos; (controles) 64 indivíduos]. Os participantes realizaram capnografia volumétrica antes, durante e após seis minutos em esteira. Análise estatística realizada pelos testes de Friedman, Mann-Whitney e Kruskal-Wallis, considerado a idade e o sexo. Alpha = 0,05. Resultados: Avaliação de seis minutos em esteira: na fibrose cística, os parâmetros da capnografia volumétrica foram diferentes antes, durante e após seis minutos em esteira, o mesmo ocorreu nos controles, exceto para o Slp2. Considerando a idade: (Slp3) diferença na FC, independentemente da idade, em todos os momentos e nos controles apenas para ≥ 12 anos; (Slp3/TV) diferença para fibrose cística e controles independentemente da idade; (Slp2) diferença apenas para o grupo fibrose cística, independentemente da idade. Considerando o sexo: (Slp3 e Slp3/TV) diferença para fibrose cística, independentemente do sexo, e controles apenas no sexo masculino; (Slp2) diferença para fibrose cística e sexo feminino. Análise entre grupos (fibrose cística versus controles): Slp3 e Slp3/TV identificou a fibrose cística, independentemente da idade e sexo, enquanto o Slp2 evidenciou a fibrose cística considerando a idade. Conclusão: A fibrose cística apresentou maiores valores dos parâmetros antes, durante e após exercício, inclusive quando se considerou idade e sexo, podendo indicar não homogeneidade da distribuição da ventilação nas vias periféricas.

Lung disease and vitamin D levels in cystic fibrosis infants and preschoolers.

INTRODUCTION: Vitamin D acts on the immune system and lung response. Patients with cystic fibrosis (CF) may be deficient in this vitamin. The aims of the study were to evaluate vitamin D levels and severity of lung disease in infants and preschoolers diagnosed with CF, and to compare them to a group of children without pancreatic insufficiency (PI). METHODS: Patients with CF up to 4 years old were included, and compared to an age-matched group of children without diagnosis of CF. CF group had medical records and High Resolution Thorax Computed Tomography (HRCCT) evaluated in order to verify the severity of lung disease. Information on demographic data, sun exposure habits, supplemental vitamin D therapy, and on the season at the time of vitamin D sampling were collected for both groups. RESULTS: This study included 45 patients in the CF group and 102 in the non-CF group, with no differences in age (P = 0.327) between them. There was no association between vitamin D levels and markers of lung disease in the CF group. The non-CF group had lower daily sun exposure (P = 0.034), and lower supplementation than the CF group (P < 0.001). Supplementation and seasonality were the determinant variables for vitamin D levels, which were lower for non-supplemented children and for assessments during fall/winter. CONCLUSION: There was no association between lung disease severity and vitamin D levels in CF group. Supplementation and seasonality were associated to higher vitamin levels.

Evaluation of respiratory dynamics by volumetric capnography during submaximal exercise protocol of six minutes on treadmill in cystic fibrosis patients.

OBJECTIVES: Volumetric capnography provides the standard CO2 elimination by the volume expired per respiratory cycle and is a measure to assess pulmonary involvement. Thus, the objective of this study was to evaluate the respiratory dynamics of healthy control subjects and those with cystic fibrosis in a submaximal exercise protocol for six minutes on the treadmill, using volumetric capnography parameters (slope 3 [Slp3], Slp3/tidal volume [Slp3/TV], and slope 2 [Slp2]). METHODS: This was a cross-sectional study with 128 subjects (cystic fibrosis, 64 subjects; controls, 64 subjects]. Participants underwent volumetric capnography before, during, and after six minutes on the treadmill. Statistical analysis was performed using the Friedman, Mann-Whitney, and Kruskal-Wallis tests, considering age and sex. An alpha=0.05 was considered. RESULTS: Six minutes on the treadmill evaluation: in cystic fibrosis, volumetric capnography parameters were different before, during, and after six minutes on the treadmill; the same was observed for the controls, except for Slp2. Regarding age, an Slp3 difference was observed in cystic fibrosis patients regardless of age, at all moments, and in controls for age≥12 years; a difference in Slp3/TV was observed in cystic fibrosis and controls, regardless of age; and an Slp2 difference in the cystic fibrosis, regardless of age. Regarding sex, Slp3 and Slp3/TV differences were observed in cystic fibrosis regardless of sex, and in controls in male participants; an Slp2 difference was observed in the cystic fibrosis and female participants. The analysis between groups (cystic fibrosis and controls) indicated that Slp3 and Slp3/TV has identified the CF, regardless of age and sex, while the Slp2 showed the CF considering age. CONCLUSIONS: Cystic fibrosis showed greater values of the parameters before, during, and after exercise, even when stratified by age and sex, which may indicate ventilation inhomogeneity in the peripheral pathways in the cystic fibrosis.

Recurrent wheezing in preterm infants: Prevalence and risk factors.

OBJECTIVE: To evaluate the prevalence and risk factors associated with progression to recurrent wheezing in preterm infants. METHODS: The cross-sectional study was carried out in 2014 and 2015 and analyzed preterm infants born between 2011 and 2012. The search for these children was performed in a university maternity hospital and a Special Immunobiological Reference Center. The evaluation was performed through a questionnaire applied during a telephone interview. RESULTS: The study included 445 children aged 39 (18-54) months. In the univariate analysis, the risk factors with the greatest chance of recurrent wheezing were birth weight <1000g, gestational age <28 weeks, living with two or more siblings, food allergy, and atopic dermatitis in the child, as well as food allergy and asthma in the parents. In the multivariate analysis, there was a significant association between recurrent wheezing and gestational age at birth <28 weeks, food allergy and atopic dermatitis in the child, and living with two or more children. Of the 445 analyzed subjects, 194 received passive immunization against the respiratory syncytial virus, and 251 preterm infants were not immunized. There was a difference between the gestational age of these subgroups (p<0.001). The overall prevalence of recurrent wheezing was 27.4% (95% CI: 23.42-31.70), whereas in the children who received passive immunization it was 36.1% (95% CI: 29.55-43.03). CONCLUSIONS: Personal history of atopy, lower gestational age, and living with two or more children had a significant association with recurrent wheezing. Children with lower gestational age who received passive immunization against the respiratory syncytial virus had a higher prevalence of recurrent wheezing than the group with higher gestational age.

Spirometry and volumetric capnography in lung function assessment of obese and normal-weight individuals without asthma / Espirometria e capnografia volumétrica na avaliação da função pulmonar de indivíduos obesos e eutróficos sem asma

Abstract Objective: To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. Methods: Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. Results: At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV1/FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p < 0.05). Volumetric capnography showed that obese individuals had a higher volume of produced carbon dioxide and alveolar tidal volume (p < 0.05). Additionally, the associations between dead space volume and tidal volume, as well as phase-3 slope normalized by tidal volume, were lower in healthy subjects (p < 0.05). These data suggest that obesity does not alter ventilation homogeneity, but flow homogeneity. After subdividing the groups by age, a greater difference in lung function was observed in obese and healthy individuals aged >11 years (p < 0.05). Conclusion: Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV1/FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes.

Resumo Objetivo: Analisar e comparar a função pulmonar de crianças e adolescentes obesos e eutróficos saudáveis, sem asma, pela espirometria e capnografia volumétrica. Métodos: Estudo transversal com 77 indivíduos (38 obesos) entre cinco e 17 anos. Todos fizeram espirometria e capnografia volumétrica. Os obesos repetiram as avaliações após o uso de broncodilatador. Resultados: Na avaliação da espirometria, os indivíduos obesos, quando comparados com o grupo controle, apresentaram menores valores no volume expiratório forçado no primeiro segundo pela capacidade vital forçada (VEF1/CVF) e nos fluxos expiratórios a 75% da CVF e entre 25-75% da mesma (p < 0,05). A capnografia volumétrica demonstrou que os obesos apresentam maior volume produzido de dióxido de carbono e volume corrente alveolar (p < 0,05). Além disso, a relação entre o volume espaço morto e volume corrente, bem como o slope da fase 3 normalizado pelo volume corrente, foi menor nos indivíduos saudáveis (p < 0,05). Esses dados sugerem que a obesidade não altera a homogeneidade da ventilação, mas sim dos fluxos. Ao subdividir os grupos por idade, foi observada maior diferença na função pulmonar entre indivíduos obesos e saudáveis na faixa acima de 11 anos (p < 0,05). Conclusão: Mesmo sem o diagnóstico de asma por critérios clínicos e sem resposta ao uso de broncodilatador, os indivíduos obesos apresentaram menores valores no VEF1/CVF e nos fluxos expiratórios forçados, o que indica a presença de processo obstrutivo. A capnografia volumétrica indicou nos indivíduos obesos maior volume corrente alveolar, sem alterações na homogeneidade da ventilação, o que sugere alteração nos fluxos, sem comprometimento dos volumes pulmonares.

Physical activity and asthma control level in children and adolescents.

BACKGROUND AND OBJECTIVE: Physical activity is defined as any bodily movement produced by a muscle contraction with increased energy expenditure. The aim of this study was to assess the physical activity, asthma control level, spirometric measurements and quality of life in children and adolescents with asthma. METHODS: We included all children and adolescents aged 7-17 years who had a diagnosis of atopic asthma and who attended the Pediatric Pulmonology Outpatient Clinic of the State University of Campinas, Brazil. Asthma control levels were evaluated by the Asthma Control Test (ACT). Physical activity was measured using the long version of the International Physical Activity Questionnaire (IPAQ) and by other questions about daily activities at school and at home over the last week. Lung function was assessed by spirometry, both pre- and post-bronchodilator (BD). Quality of life was evaluated using the Paediatric Asthma Quality of Life Questionnaire (PAQLQ). RESULTS: Out of 100 patients, 60 were classified as presenting with controlled asthma (CA) and 40 as presenting with uncontrolled asthma (UA). In the IPAQ, 29% were classified as sedentary, 17% as active and 54% as very active. There was no significant association between physical activity and the level of asthma control. We found no differences between active and sedentary children and adolescents with asthma in spirometric variables or quality of life. CONCLUSION: No associations were observed between physical activity and asthma control level, spirometric measurements and quality of life in children and adolescents with asthma.

Spirometry and volumetric capnography in lung function assessment of obese and normal-weight individuals without asthma.

OBJECTIVE: To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. METHODS: Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. RESULTS: At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV1/FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p<0.05). Volumetric capnography showed that obese individuals had a higher volume of produced carbon dioxide and alveolar tidal volume (p<0.05). Additionally, the associations between dead space volume and tidal volume, as well as phase-3 slope normalized by tidal volume, were lower in healthy subjects (p<0.05). These data suggest that obesity does not alter ventilation homogeneity, but flow homogeneity. After subdividing the groups by age, a greater difference in lung function was observed in obese and healthy individuals aged >11 years (p<0.05). CONCLUSION: Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV1/FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes.

Potential anti-inflammatory effect of low-level laser therapy on the experimental reflux laryngitis: a preliminary study.

The most common cause of laryngitis is the laryngopharyngeal reflux disease. The symptoms of laryngitis can be hoarseness, globus, chronic cough, voice fatigue, throat pain, and dysphagia. Low-level laser therapy (LLLT) is beneficial to reduce the pain and inflammatory response without side effects. Therefore, LLLT may be a useful tool for the treatment of laryngitis. This study proposes to analyze the effect of laser therapy in a model of reflux-induced laryngitis. The animals were randomly put into three groups: control--non-intubated; nasogastric intubation--intubated; and nasogastric intubation with laser therapy-intubated treated with 105-J/cm(2) laser irradiation. For the induction of laryngitis, the animals were anesthetized and a nasogastric tube was inserted through the nasopharynx until it reached the stomach, for 1 week. Thereafter, measurement of myeloperoxidase activity and the histopathological procedures were performed. In conclusion, we observed in this study that 105-J/cm(2) infrared laser reduced the influx of neutrophils in rats, and it improved the reparative collagenization of the laryngeal tissues.

Rectal forceps biopsy procedure in cystic fibrosis: technical aspects and patients perspective for clinical trials feasibility.

BACKGROUND: Measurements of CFTR function in rectal biopsies ex vivo have been used for diagnosis and prognosis of Cystic Fibrosis (CF) disease. Here, we aimed to evaluate this procedure regarding: i) viability of the rectal specimens obtained by biopsy forceps for ex vivo bioelectrical and biochemical laboratory analyses; and ii) overall assessment (comfort, invasiveness, pain, sedation requirement, etc.) of the rectal forceps biopsy procedure from the patients perspective to assess its feasibility as an outcome measure in clinical trials. METHODS: We compared three bowel preparation solutions (NaCl 0.9%, glycerol 12%, mannitol), and two biopsy forceps (standard and jumbo) in 580 rectal specimens from 132 individuals (CF and non-CF). Assessment of the overall rectal biopsy procedure (obtained by biopsy forceps) by patients was carried out by telephone surveys to 75 individuals who underwent the sigmoidoscopy procedure. RESULTS: Integrity and friability of the tissue specimens correlate with their transepithelial resistance (r = -0.438 and -0.305, respectively) and are influenced by the bowel preparation solution and biopsy forceps used, being NaCl and jumbo forceps the most compatible methods with the electrophysiological analysis. The great majority of the individuals (76%) did not report major discomfort due to the short procedure time (max 15 min) and considered it relatively painless (79%). Importantly, most (88%) accept repeating it at least for one more time and 53% for more than 4 times. CONCLUSIONS: Obtaining rectal biopsies with a flexible endoscope and jumbo forceps after bowel preparation with NaCl solution is a safe procedure that can be adopted for both adults and children of any age, yielding viable specimens for CFTR bioelectrical/biochemical analyses. The procedure is well tolerated by patients, demonstrating its feasibility as an outcome measure in clinical trials.

Potentiated anti-inflammatory effect of combined 780 nm and 660 nm low level laser therapy on the experimental laryngitis.

Reflux laryngitis is a common clinic complication of nasogastric intubation (NSGI). Since there is no report concerning the effects of low level laser therapy (LLLT) on reflux laryngitis, this study aimed to analyze the protective effect of single and combined therapies with low level laser at the doses of 2.1J and 2.1+1.2 J with a total irradiation time of 30s and 30+30 s, respectively, on a model of neurogenic reflux laryngitis. NSGI was performed in Wistar rats, assigned into groups: NGI (no treatment), NLT17.5 (single therapy), and NLT17.5/10.0 (combined therapy, applied sequentially). Additional non-intubated and non-irradiated rats were use as controls (CTR). Myeloperoxidase (MPO) activity was assessed by colorimetric method after the intubation period (on days 1, 3, 5, and 7), whereas paraffin-embedded laryngeal specimens were used to carry out histopathological analysis of the inflammatory response, granulation tissue, and collagen deposition 7 days after NSGI. Significant reduction in MPO activity (p<0.05) and in the severity of the inflammatory response (p<0.05), and improvement in the granulation tissue (p<0.05) was observed in NLT17.5/10.0 group. Mast cells count was significantly decreased in NGI and NLT17.5 groups (p<0.001), whereas no difference was observed between NLT17.5/10.0 and CTR groups (p>0.05). NLT17.5/10.0 group also showed better collagenization pattern, in comparison to NGI and NLT17.5 groups. This study suggests that the combined therapy successfully modulated the inflammatory response and collagenization in experimental model of NSGI-induced neurogenic laryngitis.

Evaluation of sealing ability of three materials used as barriers over the remaining filling material after post space preparation.

The filling material remaining after post space preparation may not be enough to prevent the contamination of periapical tissues when the root canal is exposed to saliva. Thus, the purpose of this study was to evaluate leakage through three different materials used as barriers over the remaining filling. Thirty-two human premolars were selected for this study. Following the endodontic treatment, post spaces were prepared, leaving 4 mm of filling material. A barrier 1 mm high was placed over the filling material using Cotosol, VitoFil or MTA (n = 8). Absence of barrier was used as control. The specimens were immersed in 2% methylene blue dye for 12 hours, after which they were sectioned immediately below the barriers and the apical portions were ground into powder in a mill for hard tissues. The powder was immersed in absolute alcohol to dilute the dye and then the dye concentration was analyzed using an absorbance spectrophotometer. Dye concentration was classified according to scores from 0 to 4, and the scores were submitted to Kruskal-Wallis and Tukey's post-hoc tests (alpha = 0.05). Only Cotosol and MTA reduced the leakage when compared to control. Vitrofil showed leakage values similar to both MTA and control, but higher than Cotosol. In conclusion, the material used as a barrier can have an effect on leakage through the remaining filling material.

Evaluation of sealing ability of three materials used as barriers over the remaining filling material after post space preparation. / Evaluation of sealing ability of three materials used as barriers over the remaining filling material after post space preparation.

The filling material remaining after post space preparation may not be enough to prevent the contamination of periapical tissues when the root canal is exposed to saliva. Thus, the purpose of this study was to evaluate leakage through three different materials used as barriers over the remaining filling. Thirty-two human premolars were selected for this study. Following the endodontic treatment, post spaces were prepared, leaving 4 mm of filling material. A barrier 1 mm high was placed over the filling material using Cotosol, VitoFil or MTA (n = 8). Absence of barrier was used as control. The specimens were immersed in 2

methylene blue dye for 12 hours, after which they were sectioned immediately below the barriers and the apical portions were ground into powder in a mill for hard tissues. The powder was immersed in absolute alcohol to dilute the dye and then the dye concentration was analyzed using an absorbance spectrophotometer. Dye concentration was classified according to scores from 0 to 4, and the scores were submitted to Kruskal-Wallis and Tukeys post-hoc tests (alpha = 0.05). Only Cotosol and MTA reduced the leakage when compared to control. Vitrofil showed leakage values similar to both MTA and control, but higher than Cotosol. In conclusion, the material used as a barrier can have an effect on leakage through the remaining filling material.

Measurements of CFTR-mediated Cl- secretion in human rectal biopsies constitute a robust biomarker for Cystic Fibrosis diagnosis and prognosis.

BACKGROUND: Cystic Fibrosis (CF) is caused by ∼1,900 mutations in the CF transmembrane conductance regulator (CFTR) gene encoding for a cAMP-regulated chloride (Cl(-)) channel expressed in several epithelia. Clinical features are dominated by respiratory symptoms, but there is variable organ involvement thus causing diagnostic dilemmas, especially for non-classic cases. METHODOLOGY/PRINCIPAL FINDINGS: To further establish measurement of CFTR function as a sensitive and robust biomarker for diagnosis and prognosis of CF, we herein assessed cholinergic and cAMP-CFTR-mediated Cl(-) secretion in 524 freshly excised rectal biopsies from 118 individuals, including patients with confirmed CF clinical diagnosis (n=51), individuals with clinical CF suspicion (n=49) and age-matched non-CF controls (n=18). Conclusive measurements were obtained for 96% of cases. Patients with "Classic CF", presenting earlier onset of symptoms, pancreatic insufficiency, severe lung disease and low Shwachman-Kulczycki scores were found to lack CFTR-mediated Cl(-) secretion (<5%). Individuals with milder CF disease presented residual CFTR-mediated Cl(-) secretion (10-57%) and non-CF controls show CFTR-mediated Cl(-) secretion ≥ 30-35% and data evidenced good correlations with various clinical parameters. Finally, comparison of these values with those in "CF suspicion" individuals allowed to confirm CF in 16/49 individuals (33%) and exclude it in 28/49 (57%). Statistical discriminant analyses showed that colonic measurements of CFTR-mediated Cl(-) secretion are the best discriminator among Classic/Non-Classic CF and non-CF groups. CONCLUSIONS/SIGNIFICANCE: Determination of CFTR-mediated Cl(-) secretion in rectal biopsies is demonstrated here to be a sensitive, reproducible and robust predictive biomarker for the diagnosis and prognosis of CF. The method also has very high potential for (pre-)clinical trials of CFTR-modulator therapies.