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.

Determinants of Microscale pH in In Situ-Grown Dental Biofilms.

Dental biofilm pH is the most important determinant of virulence for the development of caries lesions. Confocal microscopy-based pH ratiometry allows monitoring biofilm pH with high spatial resolution. Experiments performed on simplified biofilm models under static conditions identified steep pH gradients as well as localized acidogenic foci that promote enamel demineralization. The present work used pH ratiometry to perform a comprehensive analysis of the effect of whole saliva flow on the microscale pH in complex, in situ-grown 48-h and 96-h biofilms (n = 54) from 9 healthy participants. pH was monitored in 12 areas at the biofilm bottom and top, and saliva flow with film thicknesses corresponding to those in the oral cavity was provided by an additively manufactured microfluidic flow cell. Biofilm pH was correlated to the bacterial composition, as determined by 16S rRNA gene sequencing. Biofilm acidogenicity varied considerably between participants and individual biofilms but also between different areas inside one biofilm, with pH gradients of up to 2 units. pH drops were more pronounced in 96-h than in 48-h biofilms (P = 0.0121) and virtually unaffected by unstimulated saliva flow (0.8 mm/min). Stimulated flow (8 mm/min) raised average biofilm pH to near-neutral values but it did not equilibrate vertical and horizontal pH gradients in the biofilms. pH was significantly lower at the biofilm base than at the top (P < 0.0001) and lower downstream than upstream (P = 0.0046), due to an accumulation of acids along the flow path. pH drops were positively correlated with biofilm thickness and negatively with the thickness of the saliva film covering the biofilm. Bacterial community composition was significantly different between biofilms with strong and weak pH responses but not their species richness. The present experimental study demonstrates that stimulated saliva flow, saliva film thickness, biofilm age, biofilm thickness, and bacterial composition are important modulators of microscale pH in dental biofilms.

Comparison of the Effects of Bathing and the Dry Technique on the Skin Condition of Early Neonates: A Prospective Observational Study.

BACKGROUND: In Japan, neonates have typically been bathed in a bathtub immediately after birth because bathing is a custom for cleansing impurities. However, dry technique has been introduced into many institutions since 2000. There is little scientific evidence on the benefit or harmfulness of either method to neonatal skin, and consequently, opinion remains split on which method is superior. OBJECTIVE: The purpose of the present study was to determine whether bathing or the dry technique of cleaning is better in maintaining skin health in the early neonatal period. METHODS: Transepidermal water loss (TEWL) and skin pH, considered an index of skin barrier function, were measured in each group. Tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, which are inflammatory cytokines released by keratinocytes, were measured by skin blotting. RESULTS: TEWL and skin pH of neonates were lower with the dry technique than with bathing. The expression level of IL-6 and TNF-α in chest skin of neonates was higher with bathing than with the dry technique. CONCLUSION: These results suggest that the dry technique may maintain skin health better than bathing in the early neonatal period.

Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli.

Shiga toxin-producing strains represent pathogenic group that is of concern in food production. The present study evaluated forty-eight E. coli isolates (11 with intact stx gene, while remaining isolates presented only stx-fragments) for Shiga toxin production. The four most expressive stx-producers (O26, O103, O145, and O157) were selected to evaluate effects of pH (3.5, 4.5, and 7) and temperature (35, 40, and 50°C). After determining acid stress effects in media on Stx-induction, we mimicked "in natura" conditions using milk, apple, and orange juices. Only isolates that showed the presence of intact stx gene (11/48) produced Shiga toxin. In addition, acid pH had a role in down-regulating the production of Shiga toxin, in both lactic acid and juices. In contrast, non-lethal heating (40°C), when in neutral pH and milk was a favorable environment to induce Shiga toxin. Lastly, two isolates (O26 and O103) showed a higher capacity to produce Shiga toxin and were included in a genomic cluster with other E. coli involved in worldwide foodborne outbreaks. The induction of this toxin when subjected to 40°C may represent a potential risk to the consumer, since the pathogenic effect of oral ingestion of Shiga toxin has already been proved in an animal model.

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.

Antigingivitis, Desensitizing, and Antiplaque Effects of Alkaline Toothpastes: A Randomized Clinical Trial.

Gingivitis is a widespread disease commonly associated with dentin hypersensitivity, that, in turn, may complicate routine dental care, leading to plaque accumulation. We aimed to assess the antigingivitis, desensitizing, and antiplaque effects of a fluoride-containing (TWF) alkaline toothpaste and a fluoride-free (TW) alkaline toothpaste. Eighty-four consenting patients aged 20-25 years with diagnosed gingivitis and dentin hypersensitivity (DH) were recruited in this double-blind, parallel-group study and randomly divided into two groups (each n = 42). Eighty-two patients completed the entire study protocol. The outcomes were assessed after 4 weeks of intervention. A significant improvement in gingival condition was found according to the modified gingival index, with effect sizes of 0.99 [CI95%: 0.52-1.46] and 1.71 [CI95%: 1.18-2.24], and the gingival bleeding index, with effect sizes of 3.17 [CI95%: 2.39-3.94] and 2.64 [CI95%: 1.96-3.32] in the TW and TWF groups, respectively. DH also decreased in both groups, with a significantly greater reduction in the TWF group (effect sizes of 3.28 [CI95%: 2.51-4.04] and 3.10 [CI95%: 2.40-3.80] according to the visual analog scale and Schiff scale, respectively). No side effects were registered. In conclusion, the use of alkaline toothpaste provided a significant reduction in gingival inflammation and bleeding, DH, and oral hygiene after 4 weeks of daily use in young adults. Trial Registration: NCT0562376. Funding: none.

pH influences the volumetric change of calcium silicate- and epoxy resin-based root canal sealers: An ex vivo micro-CT study.

This study assessed the influence of pH variation on the volumetric change of EndoSequence BC Sealer compared to AH Plus Jet. Eighteen single-rooted teeth were uniformly prepared and filled with one of the sealers. After 24-h storing, samples were scanned in a micro-CT device. Then, roots were immersed in 20 ml phosphate-buffered saline (PBS) with pH of 5, 7 or 12 at 37°C for 7 and 30 days and rescanned. Statistical analysis was performed using Shapiro-Wilk's test, one-way ANOVA and Tukey's or Student's t-tests (p < 0.05). Differences between sealers were observed only at neutral pH and after 30 days of acidic pH exposure, with a higher loss of EndoSequence (p < 0.05). After 7 days, alkaline pH reduced and increased the volumetric loss of EndoSequence and AH Plus, respectively, compared to neutral pH (p < 0.05). It can be concluded that the pH directly influenced the volumetric change of both tested root canal sealers in different ways.

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)

Effect of postbiotic-toothpaste on salivary levels of IgA in 6- to 12-year-old children: Study protocol for a randomized triple-blind placebo-controlled trial.

Background: Children in mixed dentition are highly at risk for dental caries, which is a major health issue worldwide. Despite their effect in controlling dental caries, using probiotics can be challenging. Therefore, it has been advised to use their inanimate forms, called postbiotics. We hypothesize that postbiotics can enhance the oral immunity. Methods: The aim of this triple-blind, randomized, placebo-controlled trial is to investigate the effect of postbiotic-toothpaste (Bifidobacterium animalis subsp. animalis) on salivary levels of Immunoglobulin A (IgA) and pH in children. Using comparing two means formula to calculate the sample size, for this trial 80 healthy 6- to 12-year-old children during mixed dentition with no cavitated dental caries will be selected by convenience sampling method and randomly allocated to two groups, postbiotic-toothpaste or placebo-toothpaste. Saliva samples will be gathered at baseline and four weeks after the intervention. The level of salivary IgA will be determined by ELISA and salivary pH will be measured using a pH meter. Data will be compared within and between groups using independent t-test and paired t-test, in case of normality, with a p < 0.05 as statistically significant. Discussion: If postbiotics-toothpaste prove to be effective in improving the oral immunity, they can be used to prevent dental caries and other oral diseases. The result of this study can help researchers who are working on the immunomodulatory effects of postbiotics in children. Trial registration number: Iranian Registry of Clinical Trials (IRCT), IRCT20191016045128N2. Registered on 7 March 2022.

Salivary Flow Rate During Toothbrushing.

PURPOSE: To determine the salivary flow rate and subsequent dilution of toothpaste and assess the pH of oral fluids during toothbrushing with toothpastes of various pHs. MATERIALS AND METHODS: The study was conducted as an in-vivo trial involving 30 healthy volunteers. The participants took part in a series of trials distributed over four appointments. After a screening check, in which the participants' stimulated and unstimulated salivary flow rate and buffering capacities were determined, four test series involving toothbrushing were conducted. Participants brushed their teeth using a manual toothbrush for 2 min: once without toothpaste and three times using toothpastes of varying pHs. The salivary flow rate and subsequent dilution of the toothpaste was determined. Additionally, the pH of the collected oral fluid was analysed. RESULTS: Brushing teeth with toothpaste caused a statistically significant increase in salivary flow rate (median/IQR in ml/min) (Elmex Kariesschutz 3.29/1.36, Colgate Total Original 3.23/1.08, Elmex Sensitive Professional 3.18/1.39) when compared to brushing teeth using a manual toothbrush without toothpaste (1.85/0.78) (p < 0.05). The variation in pH of the oral fluid samples was dictated primarily by the pH of the toothpaste used. CONCLUSION: The salivary flow rate when brushing using toothpaste was similar across all tested toothpastes, independent of pH, and had an average median of 3.23 ml/min. The dilution of 1 g of toothpaste during a standard toothbrushing procedure of 2 min is therefore approximately at a ratio of one part toothpaste to 6.5 parts saliva.

Finite-Time Thermodynamic Modeling and Analysis of Seawater Acidification Process in Electrochemical Acidification Cell.

The unsteady process of the acidification of seawater by using an electrochemical acidification cell (EAC) is studied in this paper. The model of the concentration of hydrogen ions (H+) in the effluent seawater and the cell voltage of EAC varying with time and working current are built by applying the theory of finite-time thermodynamics, respectively. The semi-empirical formulas of the concentration of H+ in the effluent seawater and the cell voltage under the constant current of the Ionpure EAC are obtained, respectively, by fitting the experimental data of the Ionpure EAC. Then, the simulated data are compared with the experimental data. The total work consumption and average power consumption of the Ionpure EAC are obtained from the semi-empirical formulas. The results show that the semi-empirical formulas can simulate the operation process of the Ionpure EAC well. The validity of the models is verified. The increase of the working current will increase the total work consumption and average power consumption of the Ionpure EAC. The proper current can be selected in engineering practice to achieve different goals, such as high efficiency or low energy consumption. The obtained results can provide some guidelines for the optimal design and optimization of EAC.

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.

In vitro bioactivity of newly introduced dual-cured resin-modified calcium silicate cement.

Background: This study was designed to investigate the in vitro bioactivity of a new dual cured calcium silicate cement (TheraCal PT) compared to its light cured (TheraCal LC) and chemically set (Biodentine) counterparts. Materials and Methods: The study is an in vitro original research article. Prepared cements discs were immersed in deionized water. Ca2+ release was evaluated using inductively coupled plasma-optical emission spectrometry while pH was assessed using a pH meter after 1, 14, and 28 days. Discs for surface characterization were immersed in phosphate-buffered saline (PBS) and were examined using an environmental scanning electron microscope with energy dispersive X-ray (ESEM/EDX), immediately after setting and at 1, 14, and 28 days intervals after that. Attenuated total reflectance (ATR)/Fourier transform infrared (FTIR) and Raman spectroscopy analyses were performed after setting and after 28 days storage in PBS. Statistical analysis was performed using the two-way repeated measure analysis of variance test followed by Bonferroni test for multiple comparisons (P < 0.05). Results: Biodentine exhibited the highest mean values for Ca2+ release (792,639,278 ppm) and pH (10.99, 12.7, 11.54) at all time intervals. ESEM/EDX displayed a continuous layer of calcium phosphate formed by Biodentine and TheraCal LC while TheraCal PT developed scarce interrupted precipitates after immersion in PBS. ATR/FTIR and Raman spectroscopy for the formed precipitates confirmed the presence of phosphate and Ca (OH) 2 in Biodentine, TheraCal LC and TheraCal PT. Conclusion: TheraCal PT exhibited limited in vitro bioactivity which may limit its prognosis in clinical applications for vital pulp therapy. TheraCal LC is considered a potential bioactive calcium silicate cement despite its lower Ca2+ release compared to Biodentine. Highest bioactivity was observed in Biodentine.

Diagnosing metabolic acidosis in chronic kidney disease: importance of blood pH and serum anion gap.

Metabolic acidosis is one of the most common complications of chronic kidney disease (CKD). It is associated with the progression of CKD, and many other functional impairments. Until recently, only serum bicarbonate levels have been used to evaluate acid-base changes in patients with reduced kidney function. However, recent emerging evidence suggests that nephrologists should reevaluate the clinical approach for diagnosing metabolic acidosis in patients with CKD based on two perspectives; pH and anion gap. Biochemistry and physiology textbooks clearly indicate that blood pH is the most important acid-base parameter for cellular function. Therefore, it is important to determine if the prognostic impact of hypobicarbonatemia varies according to pH level. A recent cohort study of CKD patients showed that venous pH modified the association between a low bicarbonate level and the progression of CKD. Furthermore, acidosis with a high anion gap has recently been recognized as an important prognostic factor, because veverimer, a nonabsorbable hydrochloride-binding polymer, has been shown to improve kidney function and decrease the anion gap. Acidosis with high anion gap frequently develops in later stages of CKD. Therefore, the anion gap is a time-varying factor and renal function (estimated glomerular filtration rate) is a time-dependent confounder for the anion gap and renal outcomes. Recent analyses using marginal structural models showed that acidosis with a high anion gap was associated with a high risk of CKD. Based on these observations, reconsideration of the clinical approach to diagnosing and treating metabolic acidosis in CKD may be warranted.

Rv0500A is a transcription factor that links Mycobacterium tuberculosis environmental response with division and impacts host colonization.

For Mycobacterium tuberculosis (Mtb) to successfully infect a host, it must be able to adapt to changes in its microenvironment, including variations in ionic signals such as pH and chloride (Cl- ), and link these responses to its growth. Transcriptional changes are a key mechanism for Mtb environmental adaptation, and we identify here Rv0500A as a novel transcriptional regulator that links Mtb environmental response and division processes. Global transcriptional profiling revealed that Rv0500A acts as a repressor and influences the expression of genes related to division, with the magnitude of its effect modulated by pH and Cl- . Rv0500A can directly bind the promoters of several of these target genes, and we identify key residues required for its DNA-binding ability and biological effect. Overexpression of rv0500A disrupted Mtb growth morphology, resulting in filamentation that was exacerbated by high environmental Cl- levels and acidic pH. Finally, we show that perturbation of rv0500A leads to attenuation of the ability of Mtb to colonize its host in vivo. Our work highlights the important link between Mtb environmental response and growth characteristics, and uncovers a new transcription factor involved in this critical facet of Mtb biology.

Associated factors with umbilical arterial pH after cesarean delivery under spinal anesthesia: a retrospective cohort study.

BACKGROUND: Maximum decrease of blood pressure and number of minutes of hypotension were independently associated with umbilical arterial pH. However, the impact of hypotension considering the duration of it on umbilical arterial pH is unknown. METHODS: Pregnant women aged ≥ 20 years who delivered a baby at full-term via a cesarean delivery under a single-shot spinal anesthesia between January 2017 and March 2019 were included. The main outcome was to predict umbilical arterial pH, based on the value of the time integral of hypotension. Patient demographics, patient comorbidities, and intraoperative data, including the total dose of ephedrine and phenylephrine by fetal delivery and cumulative duration of maternal hypotension, were evaluated. Maternal hypotension was reflected as a decrease in systolic arterial pressure and mean arterial pressure to < 80% of baseline values. The systolic arterial pressure and mean arterial pressure were independently included in a multiple regression analysis along with all other explanatory factors to predict the umbilical arterial pH. RESULTS: Of the 416 eligible patients, 381 were enrolled. When including the systolic arterial pressure or mean arterial pressure in the model, emergency cases, the total dose of ephedrine, hypertensive disorders of pregnancy, and systolic arterial pressure or mean arterial pressure values were found to be significant predictive factors of umbilical arterial pH. CONCLUSION: Our results suggest that an elevated time integral of maternal hypotension may have a negative impact on umbilical arterial pH. Therefore, to minimize the risk of fetal acidosis, maternal hypotension should be prevented with the consideration of vasopressors selection.

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.

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.