O pH da região vulvar no ciclo vital: revisão de escopo / The pH of the vulvar region in the life cycle: scoping review / El pH de la región vulvar en el ciclo vital: revisión del alcance

Introdução: mapear os estudos que mensuraram o potencial Hidrogeniônico (pH) da região vulvar no ciclo vital da mulher. Métodos: revisão de escopo conforme recomendações do Manual for Evidence Synthesis do Joanna Briggs Institute (JBI), nas bases SCOPUS, Web of Science, Academic Search Premier, PubMed, Bielefeld Academic Search Engine e Google Acadêmico em janeiro de 2022. Foram incluídos estudos publicados em português, espanhol, francês e inglês, sem limite temporal. Resultados: dos 954 documentos recuperados, 13 foram selecionados. Apurou- se que os estudos utilizaram diferentes procedimentos para as medições quanto aos equipamentos, ambiente e preparo das participantes. A média de idade apresentada pela população feminina estudada variou entre 31 e 43 anos. Os locais de medição vulvar foram os grandes e pequenos lábios, dobra interlabial e períneo. O menor valor do pH aferido foi 4,6 e o maior 6,3. Conclusões: constatou-se baixa produção de estudos acerca do pH vulvar e ênfase das pesquisas na população de mulheres adultas. A diversidade de procedimentos e locais de aferição encontrados não permite afirmações seguras sobre uma faixa de valor de pH da superfície da pele vulvar.

Introduction: to map the studies that measured the Potential of Hydrogen (pH) of the vulvar region in women's life cycle. Methods: scoping review according to recommendations from the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis in the SCOPUS, Web of Science, Academic Search Premier, PubMed, Bielefeld Academic Search Engine and Google Scholar databases in January 2022. Studies published in Portuguese, Spanish, French, and English, without time limit, were included. Results: of the 954 documents retrieved, 13 were selected. Different measurement procedures in relation to equipment, environment and preparation of participants were used in the studies. The average age of the female population ranged between 31 and 43 years. The vulvar measurement sites were the labia majora and minora, interlabial sulci and perineum. The lowest pH value measured was 4.6 and the highest was 6.3. Conclusions: there was a low production of studies on vulvar pH and an emphasis of studies on the population of adult women. The diversity of procedures and measurement sites found does not allow for safe statements about a range of pH values on the surface of the vulvar skin.

Introducción: mapear los estudios que midieron el Potencial de Hidrógeno (pH) de la región vulvar en el ciclo vital de las mujeres. Métodos: revisión del alcance según las recomendaciones del Manual for Evidence Synthesis del Joanna Briggs Institute (JBI), en las bases de datos SCOPUS, Web of Science, Academic Search Premier, PubMed, Bielefeld Academic Search Engine y Google Scholar en enero de 2022. Se incluyeron estudios publicados. en portugués, español, francés e inglés, sin límite de tiempo. Resultados: de los 954 documentos recuperados, se seleccionaron 13. En los estudios se utilizaron diferentes procedimientos de medición en relación con el equipo, el entorno y la preparación de los participantes. La edad media de la población femenina osciló entre 31 y 43 años. Los sitios de medición vulvar fueron los labios mayores y menores, el pliegue interlabial y el perineo. El valor de pH más bajo medido fue 4,6 y el más alto fue 6,3. Conclusiones: hubo una baja producción de estudios sobre pH vulvar y un énfasis de estudios en población de mujeres adultas. La diversidad de procedimientos y sitios de medición encontrados no permite realizar afirmaciones seguras sobre un rango de valores de pH en la superficie de la piel vulvar.

Índice de Dieta Mediterránea y pH Salival en Mujeres Adultas. Estudio Observacional / Mediterranean Diet Index and Salivary pH in Adult Women. Observational Study

El ser humano en el transcurso de la evolución ha cambiado la percepción de la alimentación dejando de lado el consumo de carne y sus derivados por factores éticos y morales, donde se sabe la dieta tiene gran relevancia en la salud general, siendo un factor de riesgo para la aparición de diversas enfermedades motivo por cual la saliva se ha utilizado como instrumento de diagnóstico Describir y comparar el índice de Dieta mediterránea según pH salival en mujeres estudiantes de Odontología de entre 20 a 30 años. Estudio descriptivo transversal comparativo. Participaron 17 mujeres adultas seleccionadas por criterio no probabilístico en la carrera de Odontología, quienes fueron evaluadas en su índice de Dieta mediterránea y pH salival. Se aplicó la prueba T de Student para muestras independientes y U Mann-Whitney para comparar características entre grupos en función del pH salival. Existen diferencias significativas entre grupos para la frecuencia de consumo de cereales integrales (p = 0,026), carnes magras (p = 0,021) y pH salival (p < 0,001). Existe un predominio hacia la baja adherencia a una dieta mediterránea, existiendo diferencias significativas en la frecuencia de consumo de cereales integrales y carnes magras, siendo el consumo de estos un indicador del riesgo de la cavidad oral determinado por pH.

The human being in the course of evolution has changed the perception of food, leaving aside the consumption of meat and its derivatives due to ethical and moral factors, where it is known that diet has great relevance in general health, being a factor of risk for the appearance of various diseases, which is why saliva has been used as a diagnostic tool. To describe and compare the Mediterranean Diet index according to salivary pH in female dentistry students between 20 and 30 years old. Comparative cross-sectional descriptive study. Seventeen adult women selected by non-probabilistic criteria participated in the Dentistry career, who were evaluated in their Mediterranean Diet index and salivary pH. Student's T test for independent samples and Mann-Whitney U test were applied to compare characteristics between groups based on salivary pH. There are significant differences between groups for the frequency of consumption of whole grains (p = 0.026), lean meats (p = 0.021) and salivary pH (p < 0.001). There is a predominance towards low adherence to a Mediterranean diet, with significant differences in the frequency of consumption of whole grains and lean meats, the consumption of these being an indicator of oral risk determined by pH.

Light-curing of calcium hydroxide-based liners: pH analysis and calcium ion release / Fotoativação de forradores a base de hidróxido de cálcio: análise de pH e liberação de íons cálcio

Objective: Compare the pH values and calcium ion release of calcium hydroxide-based liner materials before and after light-curing. Material and Methods: The materials evaluated were: hydrox-cal white (HW), hydrox-cal dentin (HD), Biocal (BC) and UltraBlend Plus (UB). 120 samples of the liner materials were inserted into a PVC tube (n=15). The samples from HW+A, HD+A, BC+A and UB+A were subjected to photoactivation. The other groups HW+N, HD+N, BC+N and UB+N were only inserted in a glass tube with deionized water. The pH was measured 24 hours and 14 days after the inclusion of the samples with the aid of a pH meter. The calcium release was analyzed with the aid of an atomic absorption spectophotometer at 24h and 14 days. The results were submitted to the Shapiro-Wilk test, followed by ANOVA and Tukey test (p=0.05). Results: In 24h, the groups that were not light cured showed the highest pH values (p<0.05). In 14 days, BC+N and BC+A demonstrated the lowest pH values. The groups that were not light cured also showed higher calcium release values in 24h and 14 days (p<0.05). Conclusion: Photoactivation of calcium hydroxide-based liner materials negatively interferes with calcium ion release, as well as with pH.(AU)

Objetivo: Comparar os valores de pH e liberação de íons cálcio de materiais forradores à base de hidróxido de cálcio antes e depois da fotopolimerização. Material e métodos: Os materiais avaliados foram: Hidrox-cal branco (HW), Hidrox-cal dentina (HD), Biocal (BC) e UltraBlend Plus (UB). 120 amostras dos materiais de revestimento foram inseridas em um tubo de PVC (n=15). As amostras de HW +A, HD+A, BC+A e UB+A foram submetidas à fotoativação. Os demais grupos HW +N, HD+N, BC+N e UB+N foram inseridos apenas em um tubo de vidro com água deionizada. O pH foi medido 24 horas e 14 dias após a inclusão das amostras com o auxílio de um medidor de pH. A liberação de cálcio foi analisada com o auxílio de um espectrofotômetro de absorção atômica em 24h e 14 dias. Os resultados foram submetidos ao teste de Shapiro-Wilk, seguido de ANOVA e teste de Tukey (p=0,05). Resultados: Em 24h, os grupos não fotopolimerizados apresentaram os maiores valores de pH (p<0,05). Em 14 dias, BC+N e BC+A apresentaram os menores valores de pH. Os grupos não fotopolimerizados também apresentaram maiores valores de liberação de cálcio em 24h e 14 dias (p<0,05). Conclusão: A fotoativação de materiais de revestimento à base de hidróxido de cálcio interfere negativamente na liberação de íons cálcio e no pH (AU)

Erosive potential associated with the pH of industrialized and natural drinks

Nowadays there is an increase in the consumption of acidic drinks, especially the fermented ones. Its ingestion is closely associated with the demineralization of superficial dental tissues, which characterizes dental erosion. The objective of this study was to evaluate the pH of industrialized and natural drinks. The sample consisted of soft drinks, natural and artificial juices, fermented drinks, isotonic drinks and energy from different commercial brands acquired in the city of Niterói (RJ). The products were kept at room temperature (25oC) for 1 hour and were aliquoted 3 mL of each drink to a Becker to measure pH in a specific electrode coupled to a potentiometer. The readings were performed in triplicate. The mean pH ranged from 2.34 to 4.31, the most acidic drink was the refrigerant and the less acidic, the curd. It was found that all drinks analyzed had an acidic pH. Thus, potentially erosive dental structures.

Atualmente, há um aumento no consumo de bebidas ácidas, especialmente as fermentadas. Sua ingestão está intimamente associada à desmineralização dos tecidos dentários superficiais, o que caracteriza a erosão dentária. O objetivo da presente pesquisa foi avaliar o potencial erosivo de bebidas industrializadas e naturais. A amostra de conveniência foi constituída de refrigerantes, sucos naturais e artificiais, bebidas fermentadas, isotônicos e energéticos de diferentes marcas comerciais adquiridas no município de Niterói (RJ). Os produtos foram mantidos em temperatura ambiente (25oC) durante 1 hora e foram aliquotados 3 mL de cada bebida para um Becker para a mensuração de pH em eletrodo específico acoplado a um potenciômetro. As leituras foram realizadas em triplicata. Os valores médios de pH variaram de 2,34 a 4,31, sendo a bebida mais ácida um refrigerante e a menos ácida, a coalhada. Constatou-se que todas as bebidas analisadas apresentaram um pH ácido e abaixo do crítico para a dissolução do esmalte, sendo estas potencialmente erosivas das estruturas dentárias.

Factors influencing pH value of umbilical arterial blood gas analysis in preterm infants / 中华围产医学杂志

Objective:To analyze the factors influencing pH value in umbilical arterial blood gas (UABG) analysis in preterm infants.Methods:A retrospective study was conducted on live singleton preterm infants ( n=573) who received UABG analysis in Peking University Third Hospital from January 2017 to February 2019. Analysis of variance, independent sample t-test, Spearman's or Pearson's correlation analysis, or linear regression analysis was used to analyze the influencing factors. Results:There was no significant difference in UABG pH value between preterm infants of different gestational ages (F=1.74, P=0.077). Spearman's correlation analysis found no correlation between gestational age and UABG pH value in premature infants ( r=0.003, P=0.940), and neither did Pearson's correlation between birth weight and pH value ( r=0.025, P=0.548). UABG pH value in preterm infants was linearly correlated with vaginal delivery ( t=－5.72, P<0.001), gestational hypertension ( t=－3.99, P<0.001) and placental abruption ( t=－4.52, P<0.001). Conclusions:Preterm infants at different gestational ages show a similar pH value in UABG. For those born to mothers with gestational hypertension or placental abruption, when vaginal delivery is pending, close monitoring and full preparation for resuscitation are necessary.

Effect of goal-directed fluid therapy based on stroke volume variation guidance on splanchnic perfusion in elderly patients undergoing lumbar spine surgery: evaluation using gastric mucosal pH value / 中华麻醉学杂志

Objective:To evaluate the effect of goal-directed fluid therapy (GDFT) based on stroke volume variation (SVV) guidance on splanchnic perfusion using gastric mucosal pH (pHi) value in elderly patients undergoing lumbar spine surgery.Methods:One hundred and sixty elderly patients of either sex, aged 65-80 yr, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, undergoing elective lumbar spine surgery under general anesthesia, were selected and divided into 2 groups ( n=80 each) using a random number table method: SVV-guided GDFT group (group G) and conventional fluid therapy group (group C). GDFT was performed with SVV<15% as the target in group G, while conventional fluid infusion was performed under the guidance of mean arterial pressure, central venous pressure and urine volume in group C. Intraoperative amount of crystalloid solution infused, amount of colloid solution infused, total volume of fluid infused, amount of bleeding, urine volume, use of vasoactive drugs and perioperative blood transfusion were recorded in both groups.Cardiac index, SVV, pHi, gastric intramucosal partial pressure of CO 2 (PgCO 2), PaCO 2 and results of arterial blood gas analysis were also recorded before induction of anesthesia (T 1), at 1 h after the start of surgery (T 2) and at the end of surgery (T 3). The postoperative complications, time to first flatus, time to defecation and duration of hospital stay were also recorded in both groups. Results:Compared with group C, the amount of intraoperative crystalloid solution infused, total volume of fluid infused, urine volume and requirement for vasoactive drugs were significantly decreased, the amount of colloid solution infused was increased, cardiac index and pHi value were increased at T 2, 3, and SVV, Pg-aCO 2 and arterial blood lactic acid concentrations were decreased ( P<0.05), and no significant changes were found in the intraoperative amount of bleeding, arterial blood pH value, PaCO 2 and base excess, incidence of postoperative complications, time to first flatus, time to defecation and duration of hospital stay in group G ( P>0.05). Conclusions:GDFT based on SVV guidance is superior to traditional fluid therapy in improving splanchnic perfusion in elderly patients undergoing lumbar spine surgery.

Research progress of tumor microenvironmentally regulating organelle targeted drug delivery system / 药学学报

In recent years, the use of the body's immune system for anti-tumor immunotherapy has received extensive attention. However, the immunosuppressive tumor microenvironment (TME) limits the effect of immunotherapy. Therefore, overcoming the limitations of TME and immunosuppressive cells plays an important role in tumor immunotherapy. Nano agents have great potential to reprogram the immunosuppressive microenvironment and provide an effective strategy for immunotherapy. With the continuous development of active targeting nano carrier technology and the deepening of the research on drug action sites, subcellular organ targeting nano carrier materials with more accurate active targeting function have also attracted more and more attention. This review will briefly introduce the relationship between subcellular organelles and tumor, summarize the design strategy and research progress of targeted nano drug delivery system based on the characteristics of acidity, reactive oxygen species (ROS) activity, immunogenicity, and TME of immunosuppressive cells, to provide reference for the construction of subcellular pathway targeted drug delivery system in tumor immunotherapy.

Evaluación del Efecto de un Gel con Arginina sobre el PH y Flujo Salival

RESUMEN: Se evaluó el efecto de un gel con arginina sobre el pH y flujo salival después de un uso de catorce días en mujeres con desmineralización dental leve. Se estableció un piloto de ensayo clínico controladoen el cual fueron incluidas 20 mujeres de 18 -23 años, sistémicamente sanas y con al menos un órgano dental con desmineralización ICDAS 3, dos grupos: Grupo A / sin arginina (N=10) y Grupo B/ con arginina (N=10). Se realizó una evaluación clínica y toma de una muestra de saliva no estimulada para la determinación del pH, y la medición del flujo salival al inicio y 15 días posterior a la utilización del gel. Se realizó el análisis estadístico con el programa GraphPadPrism versión 8. Una p<0,05 fue considerado como estadísticamente significativo. En ambos grupos se mantuvo el pH salival cercano a la neutralidad sin diferencias estadísticamente significativas y el flujo salival permaneció en valores normales tras la utilización del gel durante 14 días, aunque se observaron diferencias estadísticas significativas en la comparación inter-grupo. La utilización de un gel con arginina durante 14 días mantuvo el pH neutro y el flujo salival en niveles normales sin diferencias estadísticamente significativas con el grupo control.

ABSTRACT: The effect of an arginine gel on pH and salivary flow was evaluated after fourteen days of use in women with mild demineralization. A controlled pilot clinical trial was established in which 20 women aged 18-23 years, systemically healthy and with at least one dental organ with demineralization ICDAS 3 were included, two groups: Group A / without arginine (N = 10) and Group B / with arginine (N = 10). A clinical evaluation was carried out, and a sample of unstimulated saliva was taken to determine the pH and the measurement of salivary flow at the beginning and 15 days after using the gel. Statistical analysis was performed with the GraphPad Prism version 8 program. A p <0.05 was considered statistically significant. In both groups, salivary pH was maintained close to neutrality without statistically significant differences, and salivary flow remained at normal values after using the hydrogel for 14 days, although statistically significant differences were observed in the intergroup comparison. Using a gel with arginine for 14 days kept the neutral pH and salivary flow at normal levels without statistically significant differences from the control group.

Knowledge about oral health, salivary PH, body mass index and its relationship with dental caries in preschool children / Conocimiento en salud bucal, PH salival, índice de masa corporal y su relación con caries dental en preescolares

Abstract Introduction: Dental caries is a disease caused by the interaction of several factors, including diet, since the development of the biological environment that promotes cariogenic bacterial metabolism often depends on it. Objectives: To determine the prevalence of caries in preschool children from Huaura, Peru, and to confirm if there is an association between their salivary pH and body mass index (BMI) and the level of knowledge about oral health of one of their parents. Materials and methods: A non-experimental, correlational, and cross-sectional study was conducted in 126 preschoolers equally distributed in 3 age groups (3, 4, and 5 years old). The association between the presence of caries and the variables considered was determined by means of the chi-square test of independence, with a confidence level of 95% and a type I error of 5%. In addition, a multiple logistic regression analysis was performed to calculate the probability of caries development in relation to each risk factor. Results: The prevalence of caries was 80.2% (95%CI:73.2-87.2); furthermore, salivary pH (p=0.012) and the level of parental knowledge (p<0.001) were significantly associated with caries occurrence. Regarding the multiple regression analysis, an OR=0.12 (95%CI:0.02-0.63) was obtained for pH and an OR=0.50 (95%CI:0.35-0.74) for the level of parental knowledge in relation to the probability of caries development. Conclusion: The level of parental knowledge about oral health and high salivary pH levels of preschoolers were protective factors against caries development in the study population. On the other hand, no association was found between BMI and the presence of caries in 5-year-old preschoolers.

Resumen Introducción. La caries dental es una condición causada por la interacción de múltiples factores, entre ellos la dieta, ya que, con frecuencia, de ella depende el desarrollo del medio biológico propicio para el metabolismo bacteriano cariogénico. Objetivo. Determinar la prevalencia de caries en preescolares de Huaura, Perú, y confirmar si hay una asociación con el pH salival y el índice de masa corporal (IMC) de los preescolares, y con el nivel de conocimiento en salud bucal de uno de sus padres. Materiales y métodos. Estudio no experimental, correlacional y transversal realizado en 126 preescolares distribuidos equitativamente en 3 grupos etarios (3, 4 y 5 años). La asociación entre presencia de caries y las variables consideradas se determinó mediante la prueba de independencia de chi cuadrado, con un nivel de confianza del 95% y error tipo I del 5%; además, se realizó un análisis de regresión logística múltiple para calcular la probabilidad de ocurrencia de caries en relación con cada factor de riesgo. Resultados. La prevalencia de caries fue de 80.2% (IC95%:73.2-87.2); además, el pH salival (p=0.012) y el nivel de conocimiento de los padres (p<0.001) se asociaron significativamente con la ocurrencia de caries. En cuanto al análisis de regresión múltiple, se obtuvo un 0R=0.12 (IC95%:0.02-0.63) para el pH y un 0R=0.50 (IC95%:0.35-0.74) para el nivel de conocimiento de los padres en relación con la probabilidad de presentar caries. Conclusión. El nivel de conocimiento sobre salud bucal de los padres y los niveles altos de pH salival de los preescolares fueron factores protectores frente al desarrollo de caries en la población de estudio. Por otra parte, no se encontró asociación entre IMC y presencia de caries en los preescolares de 5 años.

Investigação do potencial erosivo de gomas de mascar não convencionais / Investigation the erosive potential of unconventional chewing gums

Objetivo: mensurar o potencial erosivo de gomas de mascar não convencionais disponíveis no mercado brasileiro. Material e método: estudo experimental (in vitro) de caráter quantitativo. Foram adquiridos oito sabores de gomas de mascar: Poosh® (pinta língua); Plutonita® (abraço congelante, dentada ardente, baba de bruxa e língua ácida); e TNT® (sangue, lava e tumba). Para análise da acidez, foram realizadas leituras em triplicata do pH e acidez titulável (AT), utilizando um potenciômetro e eletrodo combinado de vidro em soluções obtidas após a maceração das gomas de mascar em água duplamente deionizada. Nas soluções com valores de pH inferiores a 5,5, foi mensurada a AT adicionando-se alíquotas de 100 µLNaOH 0,1 M, até alcançar pH 5,5. Os resultados foram submetidos à Análise de Variância (ANOVA). As comparações das médias de pH e acidez titulável foram realizadas pelo teste de Tukey, com um nível de 5% de significância (p<0,05). Resultados: os valores de pH variaram entre 2,4 (abraço congelante) e 3,5 (baba de bruxa), diferin-do significantemente do controle (água mineral/pH=6,2). Os valores de acidez titulável variaram entre 628µL de NaOH 0,1 M (sangue) e 10700µL de NaOH 0,1 M (abraço congelante). A goma de mascar sabor abraço congelante apresentou o pH mais baixo e a mais elevada acidez titulável, diferindo significantemente dos demais sabores. Conclusões: as gomas de mascar avaliadas são ácidas, mas diferem quanto ao seu potencial erosivo. Seu consumo abusivo pode constituir um fator de risco para erosão dental.(AU)

Objective: to measure the erosive potential of non- -conventional chewing gums available in the Brazilian market. Material and methods: this is an in vitro study using the following flavors of chewing gums from the Brazilian market: Poosh® (tongue cleaner); Plutonita® (freezing hug, burning bite, witch slime and acid tongue); TNT® (blood, lava and tomb). For acidity analysis, pH and titratable acidity (TA) readings were performed in triplicate using a potentiometer and combined glass electrode in solutions obtained after maceration of the chewing gums in double deionized water. In solutions with pH values below 5.5, the TA was measured by adding aliquots of 100 µL 0.1 M NaOH, until pH 5.5 was reached. The results were submitted to Analysis of Variance (ANOVA). Comparisons of pH and titratable acidity means were performed by Tukey test at a 5% significance level (p<0.05). Results: the pH values that ranged from 2.4 (freezing hug) to 3.5 (witch's slime) differed significantly from the control (mineral water/ pH=6.2). Titratable acidity values ranged from 628µL of 0.1 M NaOH (blood) to 10700µL of 0.1 M NaOH (freezing hug). The freezing hug flavor chewing gum had the lowest pH and the highest titratable acidity differing significantly from the other flavors. Conclusions: the evaluated chewing gums are acidic, but differ in their erosive potential. Their abusive consumption may constitute a risk factor for dental erosion.(AU)

Cateteres nasoenterais mal posicionados: relato de casos / Catéteres nasoenterales mal posicionados: informes de casos / Poorly positioned nasoenteral catheters: case reports

RESUMO Objetivo: relatar casos de cateteres nasoenterais mal posicionados, após inserção às cegas à beira leito. Método: são apresentados três casos, os quais ocorreram em uma instituição hospitalar localizada no estado de São Paulo. Os cateteres foram inseridos pelo enfermeiro conforme protocolo institucional, para posicionamento em nível entérico. Ausculta epigástrica e mensuração do pH foram os métodos empregados na confirmação do posicionamento dos cateteres e posteriormente foi realizado o exame de Raios-X, considerado exame de referência para confirmar o posicionamento de cateteres nasoenterais. Resultados: dos três cateteres mal posicionados, dois estavam com a extremidade distal projetada para a junção esofagogástrica e uma não foi visibilizada, apesar de a ausculta ter sido positiva e os valores de pH terem sido superiores a seis. Conclusão: os resultados revelaram importantes limitações de ambos os métodos na verificação do posicionamento de cateteres nasoenterais que foram inseridos recentemente às cegas à beira leito.

RESUMEN Objetivo: reportar casos de catéteres nasoenterales mal posicionados tras inserción ciega a pie de cama. Método: se presentan tres casos, ocurridos en un hospital ubicado en el estado de São Paulo. Los catéteres fueron insertados por el enfermero según protocolo institucional, para su colocación a nivel entérico. La auscultación epigástrica y la medición del pH fueron los métodos utilizados para confirmar la posición de los catéteres y posteriormente se realizó el examen de rayos X, considerado un examen de referencia para confirmar la posición de los catéteres nasoenterales. Resultados: de los tres catéteres mal posicionados, dos tenían el extremo distal proyectado a la unión esofagogástrica y uno no se visualizaba, a pesar de que la auscultación era positiva y los valores de pH superiores a seis. Conclusión: los resultados revelaron importantes limitaciones de ambos métodos para verificar la posición de los catéteres nasoenterales recientemente insertados a ciegas a la cabecera de la cama.

ABSTRACT Objective: to report cases of poorly positioned nasoenteral catheters after blind insertion at the bedside. Method: three cases are presented, which occurred in a hospital located in the state of São Paulo. The catheters were inserted by the nurse according to institutional protocol, for placement at the enteric level. Epigastric auscultation and pH measurement were the methods used to confirm the positioning of the catheters and subsequently the X-Ray exam was performed, considered a reference exam to confirm the positioning of nasoenteral catheters. Results: of the three poorly positioned catheters, two were with the distal end projected to the esophagogastric junction and one was not visualized, despite the auscultation being positive and the pH values being higher than six. Conclusion: the results revealed important limitations of both methods in verifying the positioning of nasoenteral catheters that were recently inserted blindly at the bedside.

Spectrophotometric Analysis of Streptococcus mutans Growth and Biofilm Formation in Saliva and Histatin-5 Relate to pH and Viscosity

ABSTRACT Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.

Research progress in tumor microenvironmentally modulating nanostructures / 药学学报

Tumor microenvironment (TME) is a complex comprehensive system composed of immune cells, inflammatory cells, tumor-associated fibroblasts, microvessels, and various cytokines and chemokines. As the living environment of tumor cells, it's closely related to the occurrence, metastasis, and recurrence of tumors. The characteristics of tumor microenvironment include: weakly acidic environment, low oxygen, high concentration of reactive oxygen species (ROS) and reducing substances, immunosuppression, etc. A weakly acidic environment favors metastasis of tumor cells, hypoxia is conducive to the emergence of drug resistance, high concentration of ROS and reducing substances are beneficial for tumor treatment, and immunosuppressiveness facilitates immune escape. With the rapid development of nanotechnology, more and more nanostructures have been reported to achieve tumor treatment by regulating the tumor microenvironment. This review summarizes recent advances in the nanostructures used to regulate tumor microenvironment through changing elements, including hydrogen-ion concentration (pH), the concentration of oxygen (O2) and reactive oxygen species, and the activity of immune cells. Moreover, research directions in the future are pointed out in this review.

Decomposition rate, ph, and enamel color alteration of at-home and in-office bleaching agents

Abstract This study evaluated the decomposition rate (DR), pH, enamel color alteration (DE) and whiteness index (DWI) promoted by at-home and in-office bleaching. Enamel surface was submitted to (n=10): at-home (10%, 15%, 20% carbamide peroxide - CP, 6% hydrogen peroxide -HP) and three 35% HP agents with light irradiation (LED, laser, and halogen) or no treatment (control). The DR and pH of agents were measured after 0, 2, 4, 6 and 8 h (at-home) or after 5, 15, 20, 30 and 40 min (in-office). Color parameters (L*, a*, b*, DE, DWI) were determined at baseline and after bleaching. DR, pH, L*, a*, b* data were analyzed by one-way (at-home) or two-way (in-office) repeated measures ANOVA and Tukey test. DE and DWI, by one-way (at-home) or two-way (in-office) ANOVA and Tukey test. DR of at-home agents was similar after 6 and 8 h (p>0.05), with pH close to neutral (6.5 to 6.9, CP) or acid 5.9 (6% HP). From 4 to 8 h, DE was higher for 15% and 20% CP compared with 10% CP (p<0.05). After 40 min, DR of 35% HP agents was similar and all exhibited significant DE in one application (p<0.05), regardless light irradiation. DWI indicated whitening effect with no differences among groups (p>0.05). One 35% HP showed alkaline pH, and the others, pH < 5.5. At-home agents could be applied for 2 h (15%, 20% CP, 6% HP) and 4 h (10% CP) and the in-office agents, up to 40 min in one application, without light.

Resumo Este estudo avaliou a taxa de decomposição (DR), pH, alteração da cor do esmalte (∆E) e índice de clareamento (DWI) promovido por agentes clareadores caseiros e de consultório. A superfície do esmalte foi submetida a (n=10): agentes caseiros (10%, 15%, 20% de peróxido de carbamida - CP e 6% de peróxido de hidrogênio - HP) e três agentes a base de HP a 35% comirradiação por luz (LED, laser e halógena) ou sem tratamento (controle). A DR e pH dos agentes foi mensurada após 0, 2, 4, 6 e 8h (agentes caseiros) e após 5, 15, 20, 30 e 40 min (agentes de consultório). Parâmetros de cor (L*, a*, b*, DE e DWI) foram determinados inicialmente e após clareamento. Os dados da DR, pH, L*, a*, b* foram analisados por ANOVA um fator (agentes caseiros) ou dois fatores (agentes de consultório) de medidas repetidas e teste Tukey. ΔE e DWI por ANOVA um fator (agentes caseiros) e dois fatores (agentes de consultório) e teste Tukey. A DR dos agentes clareadores caseiros foi similar após 6 e 8 h (p>0.05), com pH próximo ao neutro (6,5 a 6,9 - CP) ou ácido (5,9- HP 6%). De 4 a 8 h, a ∆E foi maior para CP 15% e 20% comparado ao CP 10% (p<0.05). Após 40 min, a DR dos agentes HP 35% foi similar e todos exibiram ∆E significante em uma aplicação (p<0.05), independente da aplicação de luz. DWI indicou efeito clareador, sem diferenças entre os grupos (p>0.05). Um agente HP 35% exibiu pH alcalino, e os outros, pH<5.5. Os agentes clareadores caseiros poderiam ser aplicados por 2 h (15%, 20% CP e 6% HP) e 4 h (CP 10%), e os agentes clareadores de consultório, até 40 min em uma aplicação, sem luz.

Antimicrobial action, pH, and tissue dissolution capacity of 2,5% sodium hypochlorite gel and solution / Ação antimicrobiana, pH, e capacidade de dissolução tecidual de gel e solução de hipoclorito de sódio 2,5%

Objective: to evaluate antimicrobial action, pH, and tissue dissolution capacity of 2.5% sodium hypochlorite (NaOCl) gel and solution. Methods: The 2.5% NaOCl gel was produced from a colloidal base. The test groups included 2.5% NaOCl gel and solution and the control groups included gel base and distilled water. The antimicrobial activity was evaluated by the broth dilution technique against Enterococcus faecalis (ATCC 29212) at 15 and 30 seconds and at 1, 5, and 10 minutes. To evaluate tissue dissolution capacity, 30 pulp fragments of bovine incisors were weighed, 10 for each test group and 5 for each control group before and after exposure to the chemical auxiliaries. The final mass percentage of each fragment was calculated. The pH of the substances was measured in triplicate through a digital pH meter. Results: pH levels of 13.08 and 9.75 were observed for 2.5% NaOCl solution and gel, respectively. The antimicrobial action of 2.5% NaOCl was the same for both solution and gel, for all tested times. The 2.5% NaOCl solution group showed higher tissue dissolution capacity (Kruskal-Wallis and Student-Newman-Keuls tests P<0.0001). Conclusions: The type of medium, either solution or gel, containing 2.5% NaOCl did not influence the antimicrobial action at any of the tested times. However, 2.5% NaOCl gel did not present tissue dissolution capacity

Objetivo: avaliar a ação antimicrobiana, pH e capacidade de dissolução tecidual promovida por hipoclorito de sódio (NaOCl) 2,5%, nas formas líquida e gel. Métodos: O gel de NaOCl 2,5% foi produzido a partir de base coloidal. Os grupos testes foram NaOCl 2,5% gel e solução e os grupos controle incluíram a base gel e água destilada. A ação antimicrobiana foi avaliada por meio de método de diluição em caldo, frente a Enterococcus faecalis (ATCC 29212) após 15 e 30 segundos, e também a 1, 5 e 10 minutos. Para o teste de diluição tecidual, 35 fragmentos de polpa bovina (sendo 10 para cada grupo teste e 5 para o grupo controle) foram pesadas antes e após a exposição aos auxiliares químicos. O percentual de massa final de cada fragmento foi calculada. O pH dos auxiliares químicos foi medido em pHmetro digital, em triplicata. Resultados: Valores de pH iguais a 13,08 e 9,75 foram observados para solução e para o gel de NaOCl, respectivamente. A ação antimicrobiana do NaOCl foi a mesma para o gel e a solução, em todos os períodos testados. Maior capacidade de dissolução tecidual foi obtida no grupo onde se utilizou a solução de NaOCl 2,5% (Testes de Kruskal-Wallis e Student-Newman-Keuls, P<0,0001). Conclusões: A apresentação na forma de gel ou de líquido do NaOCl 2,5% não modificou a ação antimicrobiana em qualquer um dos períodos testados. Porém, o gel de NaOCl 2,5% não demonstrou capacidade de dissolução tecidual.

A Novel Contemporary Perspective Teaching Method for Interpretation of Various Acid base Disorders Citing with Examples

Introduction: The understanding of the basic concepts inArterial blood gas analysis and interpretation is an essentialskill required for all the medical students. Many creativemethods of teaching are available for the same yet sometimesit remains a challenging task. Usually, the three mainparameters like measured pH, pCO2 and HCO3 values areutilized for interpretation of various acid base disturbances.The aim of the current research study was to apply a novelrecently published arterial blood gas interpretation method forteaching purposes.Material and methods: In this newly developed method, thenet changes in pH is related to both the changes in respiratoryand non-respiratory (metabolic) component affecting the pH.A total of 90 arterial blood gas sample data’s were utilizedand classified into various groups. The changes in pH due torespiratory and non-respiratory component is calculated andcorrelated with the net changes in actual pH.Results: The magnitude and the changes in direction eitherpositive denoting the alkaline effect or negative denoting theacidic effect is very well observed in all the 90 cases and theresults are tabulated. The relationship between changes in pHdue to respiratory component with pCO2 and the changes inpH due to non-respiratory component with bicarbonate andstandard bicarbonate values were graphically analysed.Conclusion: The study concludes that it is much easier toobserve the changes in magnitude and direction in variousacid base disturbances which will help in better understandingof cases presenting with different pH, pCO2 and HCO3 values.

Gustatory Stimulations and Their Capacity Influence Buffering of the Saliva

Objective: To evaluate the influence of gustatory stimuli on the buffering capacity of saliva. Material and Methods: The buccal ph of 18 male volunteers aged 18-35 years was measured after a mouthwash with 20 ml of water as a control, and in individual disposable cups they collected the saliva for two minutes. Then, each of chewed bubble gum with sugar for two minutes, discarding the gum and made new collection of saliva, for two minutes in other disposable cups individualized. After collection, each volunteer was again subject to regular brushing with toothpaste and waited another ten minutes. The same procedure was repeated with all other substances. Salivary buffer capacity was determined by Ericsson technique. Data were submitted to analysis of variance and the means were compared by the Scott-Knott grouping test and Mann-Whitney test at 5% probability. Estimates of Pearson correlations were calculated in order to determine possible associations between the variables. Results: It was not found statistically significant differences between the initial pH variation and after eating food (p>0.05), or between gustatory stimulation and variation of salivary buffer capacity (p>0.05). Conclusion: There is no influence of gustatory stimulus aroma and flavor on the variation of salivary buffer capacity.

Environment-responsive fluorescence probes in image-guided surgery / 中华核医学与分子影像杂志

Unlike conventional imaging technologies, fluorescent imaging benefits from its safety, high-spatial resolution and real-time capability, which make it a highly adoptable imaging method for tumor detection and image-guided surgery in clinics. There are two types of fluorescent probes, including always-on type and environment-responsive type, wherein environment-responsive probes are preferred due to higher target-to-background ratios, which can improve sensitivity and specificity. The environment-responsive probes include enzyme-reactive probes, pH-sensitive probes and hypoxia responsive probes. This review summarizes recent progress in environment-responsive probes, and discusses their potentials in tumor detection and image-guided surgery.

Tumor acidic microenvironment and targeted pH molecular imaging / 中华核医学与分子影像杂志

The tumor acidosis or low extracellular pH (pHe) is a consequence of the anaerobic glycolysis and hypoxia.Tumor acidosis plays a crucial role in tumor progression,metastasis,and resistance to therapy.Recent advances in molecular imaging targeted to tumor acidic microenvironment,including the acido chemical exchange saturation transfer magnetic resonance imaging (AcidoCEST MRI),pH-sensitive nanoparticle and pH-low insertion peptide (pHLIP),offer the opportunity to facilitate the mechanism research in this field and to promote the diagnosis and treatment.This review summarizes the effects of tumor microenvironment on tumor cells and the underlying mechanisms.In addition,this article concentrates more on the application of molecular imaging targeted tumor acidic microenvironment.

Fluorescence-labeled pH-low insertion peptide imaging of the acid microenvironment of breast tumor / 中华核医学与分子影像杂志

Objective Fluorescence-labeled pH-low insertion peptide ( pHLIP ) imaging was used to analyze in vitro acidophilic characteristic of pHLIP and its dynamic distribution in the transplanted breast tumor models. Methods The red fluorescent dye Rhodamine B ( B-pHLIP ) and near-infrared fluorescent dye Cy5 ( Cy5-pHLIP ) were respectively labeled at the hydroxyl terminal of pHLIP for imaging in vitro and in vivo. The fluorescent intensity in the MDA-MB-231 breast cancer cells and the cell vitality were analyzed under different pH values (7.8, 7.4, 7.0, 6.6). In vivo dynamic fluorescent distribution, fluorescent intensi-ties and tumor/non-tumor ( T/NT) ratios in the regions of interest of tumor and normal organs at different time points (2 h, 24 h, 3 d, 7 d) were observed or calculated, and then fluorescence imaging of the isolated tis-sues was finally performed. One-way analysis of variance and least significant difference t test were used to analyze the data. Results Relative fluorescent intensity of B-pHLIP in the MDA-MB-231 cells at pH 6.6, 7.0, 7.4 and 7.8 were (100.00±9.70)％, (69.90±5.50)％, (19.80±1.40)％ and (0.40±0.04)％, re-spectively. There were significant differences between pH 6. 6 group and other groups ( F=230. 504, t=5. 029-17.669, all P<0.05). pHLIP had no significant toxic effect on MDA-MB-231 cells. After Cy5-pHLIP injection in vivo, the fluorescent intensity of tumor in mice gradually decreased, but the T/NT ratios were stable (3.42±0.27, 3.00±1.23, 3.38±0.62 and 3.51±0.37 at 2 h, 24 h, 3 d and 7 d respectively;F=0.192, P>0. 05) . The ex vivo fluorescence distribution showed that Cy5-pHLIP had a higher uptake in the tumor tissue, and the large intestine also secreted a large amount of pHLIP. Conclusions The affinity be-tween pHLIP and tumor cell membrane is significantly increased in the extracellular acidic microenviron-ment. Cy5-pHLIP enables long-term and visual monitoring the tumor-targeted distribution of pHLIP in vivo. However, the high accumulation of pHLIP in the large intestine increases the interpretation complexity of tumor imaging.