Ajuste de la relación o cociente PaO2 /Fio2 a la presión barométrica en la ciudad de La Paz 3600 msnm / Adjustment of the PaO2 /fio2 ratio or ratio to barometric pressure in the city of La Paz 3600 masl

La hipoxemia es común en los pacientes en estado crítico, la misma que puede ser causada por hipoventilación, trastornos en la ventilación/perfusión, los cortocircuitos de derecha-izquierda, o en la limitación de la difusión a través de la membrana alvéolo-capilar. Otra de las causas puede ser como resultado de las bajas presiones inspiradas de O2 como sucede en grandes alturas. La hipoxemia es uno de los parámetros importantes para la definición del síndrome de dificultad respiratoria aguda (SDRA). La relación PaO2/FiO2 se incluye en la definición de la conferencia del Consenso AmericanoEuropeo (lesión pulmonar aguda ≤ 300 y SIRA si es ≤ a 200). La hipoxia hipobárica es una manifestación que existe y que no se ha tomado en cuenta para la definición de LPA/SIRA. Cuando disminuye la presión barométrica (PB) como consecuencia de la disminución de la presión atmosférica (P atm), disminuye la presión parcial de oxígeno (PO2). Una de las formas para determinar la PaO2/FiO2 en relación a la presión barométrica es: PB ajustada: PAO2 x PaO2/FiO2/100, una fórmula similar a la publicada por West JB y utilizada en el estudio Alveoli: PaO2/FiO2 ajustada = PO2/FIO2 x (PB/760). La relación PO2/FIO2 debe ajustarse dependiendo de la presión barométrica.

Barotrauma y barodontalgia en la aviación / Barotrauma and barodontalgia in Aviation / Barotrauma e barodontalgia na aviação

Introducción: se ha estudiado ampliamente la importancia de los cambios de presión y sus consecuencias en el cuerpo humano. De esto se desprenden dos conceptos importantes: el barotrauma que se define como el daño producido por cambios en la presión atmosférica; y la barodontalgia que se define como el dolor dentario producido por variaciones de presión barométrica, por ejemplo cuando existen gases atrapados en restauraciones o en la cámara pulpar y/o conducto radicular. Estos conceptos se fundamentan en las leyes de los gases: la Ley de Difusión Gaseosa, la Ley de Dalton, la Ley de Boyle, la Ley de Charles y la Ley de Henry. Discusión: el estudio y prevención de la barodontalgia es de suma importancia, ya que aunque no tiene alta prevalencia entre los aviadores, su aparición es súbita y de alta intensidad, lo que puede provocar en el piloto una incapacidad física y mental, que aumenta el riesgo de accidentes. Conclusiones: en esta revisión, se reúnen las estrategias recomendadas para prevenir su aparición.

Introduction: the importance of pressure changes and their consequences on the human body has been widely studied. Two important concepts arise from this: barotrauma, which is defined as the damage produced by changes in atmospheric pressure; and barodontalgia, which is defined as dental pain produced by variations in barometric pressure, for example when gases are trapped in restorations or in the pulp chamber and/or root canal. These concepts are based on the gas laws: the Law of Gaseous Diffusion, Dalton's Law, Boyle's Law, Charles' Law and Henry's Law. Discusion: the study and prevention of barodontalgia is of utmost importance, since although it is not highly prevalent among aviators, its onset is sudden and of high intensity, which can cause physical and mental incapacity in the pilot, increasing the risk of accidents. Conclusions: this review brings together the recommended strategies to prevent its occurrence.

Introducão: a importância das mudanças de pressão e suas conseqüências sobre o corpo humano têm sido amplamente estudadas. Dois conceitos importantes podem ser derivados disto: barotrauma, que é definido como o dano produzido por mudanças na pressão atmosférica; e barodontalgia, que é definida como a dor dental produzida por variações na pressão barométrica, por exemplo, quando os gases estão presos em restaurações ou na câmara de polpa e/ou canal radicular. Estes conceitos são baseados nas leis do gás: a Lei de Difusão Gasosa, a Lei de Dalton, a Lei de Boyle, a Lei de Charles e a Lei de Henry. Discusion: o estudo e prevenção da barodontia é de suma importância, pois embora não seja muito prevalente entre os aviadores, seu início é repentino e de alta intensidade, o que pode causar incapacidade física e mental no piloto, aumentando o risco de acidentes. Conclusões: esta revisão reúne as estratégias recomendadas para evitar sua ocorrência.

Effect of meteorological factors on first episode and recurrence of primary spontaneous pneumothorax

SUMMARY OBJECTIVE: In this study, we evaluated the clinical characteristics and seasonal distribution of patients with primary spontaneous pneumothorax and examined the relationships between meteorological factors and pneumothorax development overall and in terms of first episode and recurrence. METHODS: The hospital records of 168 pneumothorax patients treated in our clinic between January 2016 and December 2020 were reviewed retrospectively. A cluster was defined as two or more patients with pneumothorax presenting within three consecutive days. Meteorological factors were compared between days with and without pneumothorax patients. This comparison was based on meteorological data from the day of symptom onset (D), the day before symptom onset (D1), and the difference between those days (D-D1). Meteorological data from the index day (D) were also compared between patients with first episode and recurrence of pneumothorax. RESULTS: The study included 149 (88.7%) men and 19 (11.3%) women. The mean age was 25.02±6.97 (range, 17-35; median, 26) years. Of note, 73 (43.4%) patients underwent surgery. The highest number of patients presented in November (n=19, 11.3%). In terms of season, most presentations occurred in autumn. Humidity was significantly lower on recurrence days compared with first episode (p=0.041). CONCLUSION: Our results indicated that meteorological factors (i.e., atmospheric pressure, humidity, wind speed, temperature, and precipitation) were not associated with pneumothorax development. By comparing the patients with first episode and recurrence, the humidity was significantly lower in the recurrence group.

Gasometría arterial en embarazo a muy alta altitud / Arterial blood gas analysis during pregnancy at a very high altitude

La gasometría arterial es fundamental en el diagnóstico y manejo del medio interno. El objetivo es caracterizar los valores de gasometría arterial en gestantes sanas con embarazo normoevolutivo residentes a 4 150 metros sobre el nivel del mar. Serie de casos llevada a cabo durante la gestión 2019, la cual incluye pacientes sin clínica ni antecedentes de enfermedades cardiopulmonares o hematológicas, así como ausencia de tabaquismo y residencia de al menos los últimos 6 meses. Se incluye 30 pacientes, media de edad 25.23 años (desvío estándar 3.69), con edad gestacional media de 26 semanas (desvío estándar 5.5). El valor de pH tiende a ser más alto, así como los valores de PaO2, PaCO2, HCO3 y SatpO2% son más bajos, incluso en comparación con adultos sanos residentes de la misma altitud. Existe cierta tendencia positiva hacia el incremento progresivo del pH mientras la edad gestacional avanza. La gasometría arterial en la altura, debe ser interpretada con suma precaución en relación a las condiciones barométricas, proporcionándose así, valiosa información con aplicación a la obstetricia crítica a muy alta altitud.

Arterial blood gases analysis is essential in the diagnosis and management of pathologies. The objective is to characterize arterial blood gases values in healthy pregnant residents at 4150 meters above sea level. Series case performed during 2019, including patients without a clinical features or antecedents of cardiopulmonary or hematological diseases as well as absence of smoking and residence for at least the last 6 months. Thirty patients are included, mean age 25.23 years (standard deviation 3.69), with average gestational age of 26 weeks (standard deviation 5.5). The pH tends to be higher, as well as the values of PaO2, PaCO2, HCO3 and SatpO2% are lower, even compared to healthy adults living at the same altitude. There is some positive trend towards progressive pH is higher such as gestational age progresses. Arterial gas blood analysis at altitude, should be interpreted with extreme caution in relation to barometric conditions, thus providing, valuable information to critical care obstetrics at very high altitude

Gasometría arterial en residentes a gran altura, El Alto ­ Bolivia 2020 / Arterial blood gas analysis in residents at high altitude, El Alto, Bolivia 2020

INTRODUCCIÓN: la presión barométrica determina la presión parcial de los gases tanto en el medio ambiente como a nivel alveolar pulmonar, por lo que, para una determinada presión barométrica, la presión de oxígeno y dióxido de carbono es distinta. OBJETIVO: el objetivo del presente estudio es caracterizar los valores de gasometría arterial en residentes adultos sanos a muy alta altitud en la ciudad de El Alto. METODOLOGÍA: Estudio serie de casos, realizado durante la gestión 2019 en 22 (73%) mujeres y 8 varones (27%), con una media de edad de 36.07 años. El estudio contó con la aprobación del Comité de Ética Hospitalario. RESULTADOS: a 4150 metros sobre el nivel del mar, el pH tiende hacia la alcalosis (7.43) así como la PaO2 es menor (58.69mmHg), el valor de PaCO2 (26.14mmHg) es menor correspondiente a una ciudad con mayor altitud, el valor de bicarbonato sérico (20.14mmol/L) se encuentra disminuido en compensación a la disminución de la PaCO2 y el valor de la SatO2% (91.7%) es menor al reportado a nivel del mar. Hay que destacar que el índice PaO2/FiO2 no concuerda con el cálculo realizado según la fórmula propuesta dentro de la definición de los Criterios de Berlín. Se evidencia también que, en la muestra, si bien la correlación entre la PaO2 y la SatO2% resulta como alta, no resulta perfectamente lineal. CONCLUSIÓN: resulta imperativo precisar las características propias a la fisiología correspondientes a cada altitud, buscando aplicar parámetros propios como los de la gasometría arterial para el tratamiento de las enfermedades prevalentes en cada región, así como desarrollar investigaciones específicas a gran altura, ensayar posibilidades y documentarlas.

INTRODUCTION: barometric pressure determines the partial pressure of gases both in the environment and at the pulmonary alveolar level, so for a given barometric pressure, the pressure of oxygen and carbon dioxide is different. The objective of this paper is to characterize arterial blood gas values in healthy adult residents at very high altitude in the city of El Alto. METHODOLOGY: case series study, carried out during 2019; 22 volunteers (73%) women and 8 men (27%), mean age 36.07 years are included. The study was approved by the Hospital Bioethics Committee. RESULTS: at 4150 meter above sea level, pH tends towards alkalosis (7.43) as well as PaO2 is lower (58.69mmHg), the value of PaCO2 (26.14mmHg) is lower corresponding to a city with higher altitude, the value of serum bicarbonate (20.14mmol/L) is lower in compensation at the decrease in PaCO2 and the value of SatO2% (91.7%) is lower than that reported at sea level. The PaO2/FiO2 index does not match the calculation made according to the proposed formula within the definition of the Berlin Criteria. It is also evident that, although the correlation between PaO2 and SatO2% is high, it is not perfectly linear. CONCLUSION: it is imperative to precise the characteristics corresponding to the physiology corresponding to each altitude, looking forward to apply these parameters, such as those of arterial blood gas, in the treatment of prevalent diseases for each region, and so as develop specific studies at high altitude, also testing and reporting them.

Potential impact of temperature and atmospheric pressure on the number of cases of COVID-19 in Mozambique, Southern Africa

The potential reasons why COVID-19 is not spreading rapidly in Sub-Saharan Africa include sociopolitical, biological and environmental variables. Among the latter, some studies indicate temperature and atmospheric pressure as significantly influential. Could they have impact on the number of COVID-19 cases in Mozambique? The aim of this study is to analyze the relationships between weather and the frequency of confirmed COVID-19 cases in Mozambique, Southern Africa. The study was conducted in Mozambique, Maputo area (Province and City) and Nampula Province. Daily history of weather variables ­ daily maximum and minimum temperatures and atmospheric pressure ­ was obtained from three online databases (AccuWeather, Time and Date AS and WeatherSpark) and the number of COVID-19 cases from official Government's daily Bulletins. The main statistical analyses were Pearson correlations between the variables. The first case was observed in the Maputo area on 22 March, 2020 and the cases in Mozambique increased exponentially up to 769 by 24 June, 2020. The first three cases in Nampula province were observed on 24 May 2020 but its frequency surpassed Maputo area's within one month. Temperatures showed negative correlations with the number of cases in all areas and pressure showed positive correlations in Maputo area and Nampula Province. A bubble chart allowed the visualization of the combined relationship of both weather variables and the number of cases, suggesting that the number of cases increases as temperature decreases and pressure increases. Temperature and atmospheric pressure seems to be correlated with the number of confirmed cases of COVID-19 in Mozambique. Thus, decision-makers should consider weather as a predictor of the rate at which the pandemic is spreading in the country

Effects of NSAIDs and environmental oxygen pressure on bone regeneration / Efecto de los AINEs y la presión de oxígeno ambiental sobre la regeneración ósea

Objective: To evaluate the effects of administering diclofenac and ketoprofen, as well as the effects of environmental oxygen pressure variation on mandibular bone regeneration. Methods: Thirty-six guinea pigs were distributed into two equal groups. Mandibular bone defects were performed on both groups. Group A was monitored under oxygen pressure at altitude (3320msl, 107mm Hg). Group B was monitored at sea level oxygen pressure (150msl, 157mm Hg). Each group was subdivided into 3 equal groups (A1, A2, A3 and B1, B2, B3). Subgroups A1 and B1 were given diclofenac; subgroups A2 and B2 ketoprofen; subgroups A3 and B3 NaCl. Bone regeneration was evaluated histologically on days 15 and 30. Results: After 15 days in the group controlled at sea level, the level of osteoblasts presented by the control subgroup was significantly higher (28.00±2.65) compared to the diclofenac subgroup (16.00±6.25) and to the ketoprofen subgroup (18.00±4.36); (p=0.041). After 15 days in the group controlled at altitude, the level of osteoblasts was significantly higher in the control subgroup (38.00±5.29) compared to the diclofenac subgroup (21.67±6.35) and to the ketoprofen subgroup (19.33±2.52); p=0.007. After 30 days in the group at sea level there was no difference found in the cell counting; p>0.05. After 30 days in the group controlled at altitude, the level of osteoblast was significantly higher in the control subgroup (58.00±4.58) compared to the diclofenac subgroup (34.33±4.73) and the ketoprofen subgroup (34.00±11.14); (p=0.003). Conclusion: The administration of diclofenac and ketoprofen produced lower mandibular bone regeneration, the effect being significantly more negative at sea level.

Objetivo: Evaluar el efecto de la administración de diclofenaco y ketoprofeno y de la variación de la presión de oxígeno ambiental sobre la regeneración ósea mandibular. Métodos: Participaron 36 cobayos distribuidos en dos grupos iguales. A ambos grupos se les realizaron defectos óseos mandibulares. El Grupo A fue controlado bajo presión de oxígeno en altura (3320msnm, 107mm Hg). El Grupo B fue controlado bajo presión de oxígeno a nivel del mar (150msnm, 157mm Hg). Cada grupo fue dividido en 3 subgrupos iguales (A1, A2, A3 y B1, B2, B3). Los subgrupos A1 y B1 recibieron diclofenaco; A2 y B2, ketoprofeno; A3 y B3, NaCl. La regeneración ósea fue evaluada histológicamente a los 15 y 30 días. Resultados: A nivel del mar, a los 15 días, hubo una significativa mayor cantidad de osteoblastos en el subgrupo control (28,00±2,65) comparado con el subgrupo diclofenaco (16,00±6.25) y ketoprofeno (18,00±4.36); (p=0,041). En altura, a los 15 días, hubo una significativa mayor cantidad de osteblastos en el subgrupo control (38,00±5,29) comparado con el subgrupo diclofenaco (21,67±6,35) y ketoprofeno (19,33±2,52); p=0,007. A nivel del mar, a los 30 días, no se encontró diferencia en el conteo celular; p>0,05. En altura, a los 30 días, se encontró una significativa mayor cantidad de osteoblastos en el subgrupo control (58,00±4,58) comparado con el subgrupo diclofenaco (34,33±4,73) y ketoprofeno (34,00±11,14); (p=0,003). Conclusión: La administración de diclofenaco y ketoprofeno produjeron una menor regeneración ósea mandibular, siendo este efecto significativamente más negativo a nivel del mar.

Homeopatia: formas de preparação dos medicamentos / Homeopathy: ways to prepare the medicine

A partir das colocações feitas pelo Dr. Pedro Mintz, em artigo intitulado "Dinamização em pressão ou vácuo relativo" (Revista de Homeopatia 172:26), gostaríamos de discutir alguns pontos. A busca de novas formas e novos caminhos para se obter o que Hahnemann classificou como cura é elogiável sob todos os aspectos. São muitos os caminhos que hoje se pesquisam, tendo o autor colocado mais um que, certamente, merecerá um estudo criterioso para se chegar às soluções que ele busca.

Effect of regional climatic conditions, air pollutants, and season on the occurrence and severity of injury in trauma patients

OBJECTIVE: We analyzed the association between regional weather and temporal changes on the daily occurrence of trauma emergencies and their severity. METHODS: In this cross-sectional prospective study, we investigated daily atmospheric patterns in trauma episodes in 1,344 patients in Cheongju city, South Korea, from January 2016 to December 2016 and analyzed the association of trauma occurrence and Injury Severity Scores (ISS) with weather conditions on a daily scale. RESULTS: The mean age of trauma patients was 53.0±23.8 years and average ISS was 9.0±2.0. Incidence of trauma was positively correlated with average temperature (r=0.512, P < 0.001) and atmospheric pressure (r=0.332, P=0.010) and negatively correlated with air pollutants (particulate matter less than 2.5 µm³ [PM2.5], r=−0.629, P < 0.001; particulate matter less than 10 µm³ [PM10], r=−0.679, P < 0.001). ISS was not significantly correlated with climate parameters and air pollutants, and variability was observed in the frequency and severity of trauma by time of day (highest occurrence, 16–20 pm; highest ISS, 4–8 am), day of the week (highest occurrence and highest ISS, Saturday), month of the year (highest occurrence, July; highest ISS, November), and season (highest incidence, summer; highest ISS, autumn). CONCLUSION: The study shows a positive relationship between trauma occurrence and specific weather conditions, such as atmospheric temperature and pressure. There was a negative relationship between concentrations of PM2.5 or PM10, and trauma occurrence. However, no correlation was observed between weather conditions or the concentrations of air pollutants and ISS. In addition, seasonal, circaseptan, and circadian variations exist in trauma occurrence and severity. Thus, we suggest that evaluation of a larger, population-based data set is needed to further investigate and confirm these relationships.

Eficácia do uso de plasma em pressão atmosférica na adesão de cerâmicas zircônia / Efficacy of the use of plasma at atmospheric pressure in zirconia adhesion

Um dos maiores desafios atuais da ciência dos materiais dentários é a obtenção de união efetiva e durável às cerâmicas de alto conteúdo cristalino. O objetivo do presente estudo foi avaliar a resistência de união, energia de superfície e tipos de fratura de dois sistemas cerâmicos após diferentes formas de tratamento de superfície associada à aplicação do plasma em pressão atmosférica. Para o estudo foram obtidas quarenta placas de zircônia (12 mm x 5 mm x 1,5 mm) de dois tipos de cerâmicas zircônia (E.max ZirCad e Calypso), polidas e limpas por ultrassom durante 5 minutos. Divididas aleatoriamente em 2 grupos de acordo com o sistema cerâmico e 4 subgrupos (n=5) de acordo com o tratamento de superfície, (I) controle (primer), (II) jateamento com partículas micrométricas de alumina (Al2O3) + primer, (III) jateamento com partículas micrométricas de alumina (Al2O3) + plasma + primer, (IV) plasma + primer. Foram confeccionados cento e vinte cilindros de resina composta (Z100), utilizando matrizes cilíndricas (1,0 mm x 3,0 mm) cimentadas com cimento resinoso, Multilink N, sobre as placas de zircônia. Os espécimes foram armazenados em água destilada durante 24 horas a 37° C, depois testados para microcisalhamento em máquina de teste Shimadzu EZ a 1,0 mm/min. Os dados obtidos foram submetidos à análise estatística para comparação entre os grupos E.max e Calypso em relação à resistência à união (força/área ­ MPa), ângulo de contato e os tipos de fratura. Os dados foram analisados pelos testes ANOVA One-Way e Kruskal-Wallis para resistência de união (p=0,003) e (p=0,005) e ângulo de contato (p<0,001) e (p<0,001). Não houve diferença significativa para os dados de fratura (p=0,145), pelo teste quiquadrado, com predomínio de fraturas mistas. Os valores de resistência de união das cerâmicas Y-TZP apresentaram maiores valores quando o plasma foi associado ao jateamento com óxido de alumínio e/ou primer e a aplicação somente do plasma não superou os valores alcançados pelas outras formas de tratamento da superfície. Essa associação resultou em menores valores dos ângulos de contato. Houve maior frequência de fraturas mistas quando realizado somente o tratamento com óxido de alumínio e quando em associação com o plasma.(AU)

One of the major challenges today in the science of dental materials is the achievement of effective and durable bonding to ceramics with high crystalline content. The objective of the present study was to evaluate the efficacy of plasma at atmospheric pressure in the adhesion of ceramic zirconia through the bond strength, surface energy and type of fracture of two ceramic systems after different forms of surface treatment associated with the application of plasma at atmospheric pressure. For the study forty zirconia plates (12 mm x 5 mm x 1.5 mm) were obtained from two zirconia ceramics (E.max ZirCad and Calypso), polished and cleaned by ultrasound for 5 minutes. Randomly divided into 2 groups according to the ceramic system and 4 subgroups (n = 5) according to the surface treatment, control (primer), primer + blasting with micrometric alumina (Al2O3) particles, primer + blasting with micrometric particles of alumina (Al2O3) + plasma, primer + plasma. One hundred and twenty cylinders of composite resin (Z-100) were made using cylindrical matrices (1.0 mm x 3.0 mm) cemented on the zirconia plates. The specimens were stored in distilled water for 24 hours at 37°C, then tested for microshear on a Shimadzu EZ test machine at 0.5 mm / min. The obtained data were submitted to statistical analysis for comparison between the E.max and Calypso groups in relation to the bond strength (strength / area - Mpa), contact angle and fracture types. The data were analyzed by ANOVA One-Way and Kruskal-Wallis tests for bond strength (p=0.003) and (p=0.005) and contact angle (p<0.001) and (p<0.001). There was no significant difference for the fracture data (p = 0.145), by the chi-square test, with a predominance of mixed fractures. The bond strength values of the Y-TZP ceramics showed higher values when the plasma was associated with blasting with aluminum oxide and / or primer and the application of only the plasma did not exceed the values reached by the other forms of surface treatment. This association resulted in lower values of contact angles. It is a higher frequency of mixed fractures when only aluminum oxide treatment is performed and when it is associated with plasma.(AU)

Influencia de la presión de oxígeno ambiental sobre la regeneración ósea guiada / Influence of ambient oxygen pressure on guided bone regeration

RESUMEN: Objetivo: Evaluar la influencia de la variación en la presión de oxígeno ambiental sobre la regeneración ósea guiada en cobayos. Material y método: Treinta y dos cobayos machos de 750±50g de peso fueron asignados en 2 grupos de 16 integrantes cada uno (grupo A: trabajado a 150msnm en la ciudad de Lima y a presión de oxígeno de 157mmHg; grupo B: trabajado a 3.230msnm en la ciudad de Jauja y a presión de oxígeno de 107mmHg). En ambos grupos se indujeron defectos óseos mandibulares de 5×6mm a través de un acceso quirúrgico extraoral; a 8 cobayos de cada grupo se les recubrió el defecto con una membrana de colágeno reabsorbible de origen porcino, mas al resto de animales no. Se evaluó el conteo celular de osteoblastos y osteocitos a los 15 y 30 días postoperatoriamente. Resultados: A los 15 y a los 30 días, en los grupos trabajados en altura y en los que se aplicó la membrana, la cantidad de osteoblastos fue 71±12,1 cél/camp y 83±7,2 cél/camp respectivamente, y la de osteocitos fue 34,5±6,6 cél/camp y 25±7,6 respectivamente; siendo estos grupos, en todas las comparaciones, los que tuvieron mayor cantidad de células óseas, aunque sin ser diferencias estadísticamente significativas (p>0,05). Conclusión: Se encontró tendencia a formar mayor cantidad de células óseas en las muestras tratadas con regeneración ósea y expuestas a la altitud comparados con el nivel del mar.

ABSTRACT: Objective: To evaluate the influence of the variation in ambient oxygen pressure on guided bone regeneration in guinea pigs. Material and method: A total of 32 male guinea pigs weighing 750±50g were assigned into two groups of 16 (group A: studied at 150 metres above sea level in the city of Lima and oxygen pressure of 157mmHg; group B: was at 3230 meters above sea level in the city of Jauja and an oxygen pressure of 107mmHg). Bone defects of 5×6mm were induced in the jaw in both groups through extra-oral surgical access. The defect in 8 guinea pigs of each group were covered with a porcine resorbable collagen membrane, but not in the other animals. The osteoblast and osteocyte cell counts were evaluated at 15 and 30 days post-operatively. Results: At 15 and 30 days, in the groups studied at height and with the membrane applied, the osteoblast count was 71±12.1 cells/field, and 83±7.2 cells/field, respectively, and an osteocyte count of 34.5±6.6 cells/field, and 25±7.6 cells/field, respectively. These groups had a higher number of bone cells in all the comparisons, but there were no statistically significant differences (P>.05). Conclusion: There was a tendency to form a greater amount of bone cells was found in the samples treated with bone regeneration and exposed to altitude compared to those at sea level.

Efeitos da Hipóxia na Variabilidade da Frequência Cardíaca em Indivíduos Saudáveis: Uma Revisão Sistemática / Effects of Hypoxia on Heart Rate Variability in Healthy Individuals: A Systematic Review

Fundamento: A hipóxia é uma condição fisiológica que pode influenciar a modulação autonômica cardíaca, qualpode ser avaliada pelas flutuações espontâneas da frequência cardíaca, chamada de variabilidade da frequência cardíaca (VFC). Estudos têm reportado reduções ou manutenção da VFC em situação de hipóxia apresentando efeitos controversos. Há uma lacuna no conhecimento em relação às modificações da VFC durante a hipóxia. Objetivo: Revisar sistematicamente estudos que investigaram os efeitos da hipóxia na VFC em adultos saudáveis e não aclimatados durante o repouso. Métodos: A presente revisão sistemática foi realizada a partir da diretriz PRISMA. Os termos utilizados para a busca nas bases MEDLINE, SCOPUS, LILACS e EUROPE PMC foram: "heart rate variability" OR "cardiac autonomic modulation" OR "cardiac autonomic regulation" AND (hypoxia OR altitude) NOT intermitente NOT sleep. Os registros foram filtrados por espécie, idade e idiomas. Resultados: Ao final da triagem e elegibilidade restaram 13 artigos para a síntese qualitativa. Discussão: Os estudos utilizam protocolos experimentais variados que envolvem diferença na pressão barométrica, no nível de oxigênio, no tempo de exposição à hipóxia e no controle da frequência respiratória. Possivelmente a influência desses fatores e também a variação interindividual à hipóxia podem justificar diferentes respostas na VFC. Conclusão: A partir dos estudos investigados, a hipóxia foi capaz de gerar uma queda na VFC, seja por retirada ou manutenção da modulação vagal, ou por predomínio simpático ou mesmo pela combinação dessas respostas em adultos saudáveis não aclimatados a hipóxia. Este efeito parece ser dependente do nível de altitude e da pressão barométrica

Background: Hypoxia is a physiological condition that may affect the cardiac autonomic modulation, which can be assessed by spontaneous fluctuations in heart rate, know as heart rate variability (HRV). Studies have reported reductions or maintenance of HRV in hypoxic situation presenting controversial effects. There is a knowledge gap in relation to changes in HRV during hypoxia. Objective: The aim of this study was to systematically review the effects of hypoxia on HRV in unacclimatized healthy adults at rest. Methods: This systematic review was performed according to PRISMA guidelines. Search terms used in MEDLINE, SCOPUS, LILACS and EUROPE PMC database were: "heart rate variability" OR "cardiac autonomic modulation" OR "cardiac autonomic regulation" AND NOT intermittent NOT sleep (hypoxia OR altitude). Records were filtered by species, age group and language. Results: At the end of the screening and eligibility, 13 manuscripts remained for qualitative synthesis. Discussion: The studies used different experimental protocols involving difference in barometric pressure, oxygen level, time of exposure to hypoxia and control of respiratory rate. Possibly the influence of these factors and also the interindividual variation to hypoxia may justify different responses in HRV. Conclusion: Based on the investigated studies, hypoxia has been capable of generating a decrease in HRV, either by reduction or maintenance of vagal modulation, or by sympathetic predominance or even the combination of these responses in healthy adults unacclimatized to hypoxia. This effect appears to be dependent on altitude level and barometric pressure

Effects of Temperature and Pressure on Acute Stroke Incidence Assessed Using a Korean Nationwide Insurance Database / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Many studies have evaluated the association between weather and stroke, with variable conclusions. Herein we determined the relationships between daily meteorological parameters and acute stroke incidence in South Korea. METHODS: Patients with acute stroke (2,894) were identified by standard sampling of a nationwide insurance claims database from January to December 2011. We used multiple Poisson regression analyses of stroke incidence and meteorological parameters (mean temperature, diurnal temperature change, temperature differences over the preceding 24 hours, atmospheric pressure, humidity, wind speed, and physiologically equivalent temperature) to calculate the relative risk of stroke incidence associated with meteorological parameters. RESULTS: There were no seasonal variations in the incidences of ischemic (2,176) or hemorrhagic (718) stroke. Temperature change during the day was positively correlated with ischemic stroke in men (relative risk [RR] 1.027; 95% confidence interval [CI] 1.006–1.05) and older patients (≥65 years) (RR 1.031, 95% CI 1.011–1.052). Temperature differences over the preceding 24 hours had a negative correlation with all strokes (RR 0.968, 95% CI 0.941–0.996), especially among older women. Diurnal variation of atmospheric pressure was also significantly associated with the incidence of ischemic stroke (age < 65 years, RR 1.051, 95% CI 1.011–1.092; age≥65 years, RR 0.966, 95% CI 0.936–0.997). CONCLUSIONS: Diurnal temperature change, temperature differences over the preceding 24 hours, and diurnal variation of atmospheric pressure were associated with daily stroke incidence. These findings may enhance our understanding of the relationship between stroke and weather.

Filtro de agua en la preparación de quimioterapia para optimizar la bioseguridad / Water filter in the preparation of chemotherapy to optimize biosafety

Los quimioterápicos son elaborados a una presión barométrica correspondiente a nivel del mar. En ciudades de altitud elevada como La Paz (3600 msnm), la presión al interior de los frascos es superior, esto constituye un riesgo de salida del medicamento. Objetivo Describir la utilidad de los filtros de agua durante la preparación de quimioterápicos para evitar eventos adversos severos en el personal de salud y medio ambiente. Material y Métodos Se adquirió quimioterápicos, Metotrexate, Adriamicina y Endoxan, para ser sometidos a pruebas de experimentación. Se cuantificó el volumen de aire expulsado desde el interior del frasco hacia la jeringa. Se evaluó la utilidad del filtro de agua, 5 ml de agua destilada en jeringas de 20 ml. Las longitudes de onda de máxima absorción de los quimioterápicos fueron obtenidos de un barrido espectral. Se determinó la concentración de cada quimioterápico en los filtros de agua a través de un espectrofotómetro Shimadzu UV1800. Resultados Los volúmenes de aire fueron distintos en cada citostático, el volumen varió de acuerdo a marca de fabricación. Las lecturas realizadas de los filtros de agua evidenciaron una concentración de Adriamicina de 33.8 ug/ml para marca FILAXIS y 32.8 ug/ml para LKM, Metotrexato LKM 7.6 ug/ml, y la ciclofosfamida 16.6 ug/ml para LKM y 14.0 ug/ml para Baxter. Conclusión La propiedad hidrosoluble de los quimioterápicos permite un uso factible de filtros de agua, reteniendo citostáticos en un porcentaje desconocido pero importante. La utilización de filtros de agua constituye en una herramienta significativa para optimizar la bioseguridad.

Chemotherapeutic drugs are made at a barometric pressure corresponding to a sea level. In cities ofhigh altitude such as La Paz (3600 m.a.s.l.), the pressure inside the drug bottle is higher and this represents a risk of leakage from drug. Objective Describe the usefulness of distilled water as water filter in the preparation of chemotherapy to avoid severe adverse events in health staffand the environment. Material and methods Chemotherapeutic drugs such as methotrexate, adriamycin and endoxan were tested. The volume of air expelledfrom inside the bottle to the syringe was measured. It was evaluated the utility of using 5 ml of distilled water in 20-mL syringes as water filter. By means of a spectral scanning it was obtained the wavelengths of maximum absorption from the chemotherapeutics. The concentration of each chemotherapeutic drug inside water filters were determined by using a Shimadzu UV1800 spectrophotometer. Results Air volumes were differentin each chemotherapeutic drug, volume varied according to manufacturing brand. Water filters reading showed a concentration of Adriamycin 33.8 ug/ml for Filaxis brand and 32.8 ug/ml for LKM, Methotrexate LKM showed 7.6 ug/ml, and cyclophosphamide 16.6 ug/ ml for LKM and 14.0 ug/ml for Baxter. Conclusion The water-soluble property of chemotherapeutic drugs allows a feasible use of distilled water as water filter which retains cytostatics in an unknown but significant percentage. The use of distilled water as water filter is a significant tool to optimize biosafety.

Spontaneous Absorption of Cerebral Air Embolus Developed Accidentally during an Intra-arterial Procedure

Cerebral arterial air embolism (CAAE), although infrequent, is a complication that can occur at any time during an invasive medical procedure. We experienced two cases of CAAE during cerebral angiography accidentally. The author reports the two cases of CAAE wherein air emboli dissolved spontaneously and immediately under normal atmospheric pressure, not under therapeutic hyperbaric environment. One of the cases shows entire dissolution of the air embolus on the moving image. This report shows that arterial air embolus can be absorbed spontaneously, and air embolus size is one of the factors that influence air embolus dissolution besides hyperbaric oxygen condition.

Emergency Department Visits for Asthma Exacerbation due to Weather Conditions and Air Pollution in Chuncheon, Korea: A Case-Crossover Analysis

PURPOSE: This retrospective study was conducted to estimate the effects of climate factors and air pollution on asthma exacerbations using a case-crossover analysis. METHODS: Patients who visited the emergency department (ED) of 2 university hospitals in Chuncheon for asthma exacerbations from January 1, 2006, to December 31, 2011, were enrolled. Daily average data for meteorological factors (temperature, daily temperature range, relative humidity, wind speed, atmospheric pressure, presence of rain, solar irradiation, and presence of fog) and the daily average levels of gaseous air pollutants (SO2, NO2, O3, CO, and PM10) were obtained. A case-crossover analysis was performed using variables about the weather and air pollution at 1-week intervals between cases and controls before and after ED visits. RESULTS: There were 660 ED visits by 583 patients with asthma exacerbations. Low relative humidity (lag 1 and 2) and high wind speed (lag 1, 2, and 3) were associated with ED visits for asthma. Fog (lag 2) showed protective effects against asthma exacerbations in Chuncheon (risk increase: -29.4% [95% CI=-46.3% to -7.2%], P=0.013). These relationships were stronger in patients ≤19 years old than in those >60 years old. High levels of ambient CO (lag 1, 2, and 3) and NO2 (lag 2 and 3) were associated with decreased ED visits for asthma. However, there were no significant relationships among levels of ambient CO or NO2 and asthma exacerbations after adjusting for wind speed and relative humidity. CONCLUSIONS: High wind speed and low humidity were associated with an increased risk of asthma ED visits. Fog was associated with a decreased risk of asthma ED visits after controlling for seasonal variations in weather and air pollution.

An Evaluation of the Repetitive Tooth Bleaching with Nonthermal Atmospheric Pressure Plasma

This study was undertaken to achieve a high bleaching efficacy with plasma, through longer application and reparative bleaching processes, by different shade evaluation methods. Extracted human teeth were divided into 6 groups (n=10). All teeth were treated in pairs. Low concentration of 15% carbamide peroxide (CP) was applied, with and without plasma, for 10, 20, and 30-min tooth bleaching, respectively. The bleaching procedure was repeated once daily for four days. The teeth were maintained in a moist environment provided by artificial saliva. The Vitapan Classical shade guide and Commission Internationale de L'Eclairage (CIELAB) color system were collectively used to measure the bleaching efficacy. Color evaluation was statistically analyzed using Student t-test and one-way analysis of variance (ANOVA) complemented by Tukey's test. Combining the plasma with 15% CP showed significantly greater color changes compared to bleaching without plasma (p<0.05). A high bleaching efficacy with plasma is proportional to the repetitive application and the treatment time. A 30-min application with plasma provided the best bleaching. Repetitive bleaching showed lower probability of color relapse of the bleached tooth. The color change by shade guide correlated with the changes in CIELAB color system. A value of 1 color change units (CCU) conversion factor for overall color change (ΔE) values comparisons was 3.724 values. The two measuring methods provide a more accurate correspondence of color change. The repetitive and longer application for tooth bleaching, combined with plasma, has a strong bleaching effect and produces whiter teeth.

Comportamiento de índices fisiológicos en un grupo de estudiantes de la UniversidadNacional de Colombia sede Bogotá, expuestos de 2600 a 3800 msnm en el páramo de Sumapaz durante un día. Estudio observacional / Behavior of physiological indices in a group of students from the Universidad Nacional de Colombia in Bogotá exposed to 2600 at 3800 meters in the Sumapaz for a day. Observational Study

Objetivo: conocer los cambios fisiológicos al descenso de la presión barométrica en situaciones agudas, ya que se reduce la cantidad de oxígeno en el ambiente, la presión inspirada de oxígeno y por tanto la captación de oxígeno. En Colombia alrededor de la mitad de la población vive entre alturas de 1500 a 3000 metros sobre el nivel del mar,condición necesaria para comenzar las adaptaciones fisiológicas por el descenso de la presión barométrica. Materiales y métodos: se realizó un estudio observacionalen el que participaron de forma voluntaria 15 sujetos, estudiantes de posgrado de laUniversidad Nacional de Colombia sede Bogotá. El rango de edad estuvo entre 23 y 33 años, se realizaron medidas de presión arterial, lactato, hematocrito, saturación de oxígeno y frecuencia cardiaca. Estos índices fisiológicos se midieron en dos ocasiones;a 2600 msnm y a 3800 msnm. Resultados: la frecuencia cardiaca tuvo diferencias estadísticamente significativas entre los dos niveles con valor p= 0,0001913. Encuanto al lactato no hubo diferencias significativas, con valor p= 0,73. La saturación de oxígeno por pulso oximetría tuvo una diferencia significativa en comparación dela toma a 2600 msnm con respecto a la de 3800 msnm con valor p= 0,0006787, el hematocrito aumentó significativamente de 2600 msnm a 3800 msnm con valor p=6,078x10-07, en la presión arterial no hubo diferencias significativas en las dos mediciones.Conclusión: la exposición a grandes alturas con lleva a cambios significativos en los valores de hematocrito, saturación de oxígeno y frecuencia cardiaca como medidas de compensación ante la demanda ambiental, que deben ser tenidas en cuenta para procesos adaptativos y actividad física.

Hand-foot-and-muuth disease epidemiological staus and relationship with meteorrological variables in guangzhou, southern China, 2008-2012 / Situação epidemiológica e a relação com variáveis meteorológicas da HFMD em Guangzhou, sul da China, 2008-2012

Hand-foot-and-mouth disease (HFMD) is becoming one of the extremely common airborne and contact transmission diseases in Guangzhou, southern China, leading public health authorities to be concerned about its increased incidence. In this study, it was used an ecological study plus the negative binomial regression to identify the epidemic status of HFMD and its relationship with meteorological variables. During 2008-2012, a total of 173,524 HFMD confirmed cases were reported, 12 cases of death, yielding a fatality rate of 0.69 per 10,000. The annual incidence rates from 2008 to 2012 were 60.56, 132.44, 311.40, 402.76, and 468.59 (per 100,000), respectively, showing a rapid increasing trend. Each 1 °C rise in temperature corresponded to an increase of 9.47% (95% CI 9.36% to 9.58%) in the weekly number of HFMD cases, while a one hPa rise in atmospheric pressure corresponded to a decrease in the number of cases by 7.53% (95% CI -7.60% to -7.45%). Similarly, each one percent rise in relative humidity corresponded to an increase of 1.48% or 3.3%, and a one meter per hour rise in wind speed corresponded to an increase of 2.18% or 4.57%, in the weekly number of HFMD cases, depending on the variables considered in the model. These findings revealed that epidemic status of HFMD in Guangzhou is characterized by high morbidity but low fatality. Weather factors had a significant influence on the incidence of HFMD.

A doença de mão-pé-e-boca (HFMD) está se tornando doença extremamente comum transmitida pelo ar e contato em Guangzhou, sul da China, levando preocupação às autoridades de saúde pública acerca da sua incidência aumentada. Neste estudo foi usada parte ecológica e regressão binomial negativa para identificar o status epidêmico da HFMD e sua relação com variáveis meteorológicas. Durante 2008-2012 um total de 173.524 casos confirmados de HFMD foram apresentados, 12 com morte, elevando o índice de fatalidade a 0,69 por 10.000. As incidências anuais de 2008 a 2010 foram 60,56, 132,44, 311,40, 402,76 e 468,59 por 100.000, respectivamente, mostrando tendência de rápido aumento. Cada 1 °C de aumento da temperatura correspondeu a aumento de 9,47% (95% CI 9,36% a 9,58%) no número semanal de casos de HFMD, enquanto a 1 hPa de aumento da pressão atmosférica correspondeu a decréscimo no número de casos de 7,53% (95% CI - 7,60% a - 7,45%). De maneira semelhante cada aumento de 1% na humidade relativa correspondeu a aumento de 1,48% ou 3,3% e a um aumento de 1 metro por hora na velocidade do vento correspondeu a um aumento de 2,18% ou 4,57%, no número de casos semanais de HFMD, dependendo das variáveis consideradas no modelo. Estes achados revelaram que o status epidêmico do HFMD em Guangzhou é caracterizado por alta morbidade, mas baixa fatalidade. Fatores referentes ao tempo tiveram influência significante na incidência do HFMD.