184 research outputs found
Comparación del efecto anticariogénico entre la ovoalbúmina y un barniz fluorurado de aplicación profesional en esmalte y dentina, in situ
68 p.Introducción: Se han reportado agentes de la dieta que poseen propiedades anticariogénicas, constituyendo una posible alternativa como terapia no invasiva. Por
ejemplo, un mayor consumo de proteínas se asocia con una menor incidencia de lesiones
cariosas. La ovoalbúmina, proteína con potencial anticariogénico, ha demostrado inhibir la desmineralización de esmalte, sin embargo se desconoce la magnitud de tal efecto tanto en esmalte como dentina al ser comparada con el barniz fluorurado.
Objetivo: Comparar el efecto anticariogénico de la ovoalbúmina en relación a un barniz
fluorurado de aplicación profesional en esmalte y dentina, in situ. Metodología: Se realizó un estudio in situ, ciego, aleatorizado y crossover. Se llevó a cabo
tres fases de 14 días cada una, en las cuales 12 voluntarios usaron un aparato palatino con 3 bloques de esmalte y 3 bloques de dentina bovino, con valores de dureza superficial (DS) medidas previamente. Se aplicó en ellos una solución de sacarosa al 20% extraoralmente (8veces/día). Los voluntarios se dividieron en 3 grupos experimentales con su respectivo tratamiento (aplicados 3 veces/día): control (agua destilada), barniz fluorurado 22.600 ppm
F (agua destilada) y ovoalbúmina (solución de ovoalbúmina 1mg/mL). En los días 7
(dentina) y 14 (esmalte) de cada fase se recolectaron los bloques evaluando la
desmineralización, determinada por el % de pérdida de dureza superficial (%PDS).
Resultados: El esmalte expuesto a los tratamientos de barniz y ovoalbúmina obtuvieron una menor %PDS, indicando una reducción de la desmineralización similar (p=0,0001). En dentina el %PDS del grupo ovoalbúmina (p=0,057) fue mayor que el barniz fluorurado (p=0,001) y no difirió del control. Conclusión: La ovoalbúmina en una concentración de 1mg/mL parece tener un efecto anticariogénico sobre la desmineralización del esmalte dentario similar al barniz fluorurado de aplicación profesional. En dentina, este efecto es menos marcado. Palabras claves: Lesión cariosa- Barniz Fluorurado-Dieta –Proteínas de la dieta- Ovoalbúmin
The economic cost of losing native pollinator species for orchard prodution
The alarming loss of pollinator diversity world‐wide can reduce the productivity of pollinator‐dependent crops, which could have economic impacts. However, it is unclear to what extent the loss of a key native pollinator species affects crop production and farmer's profits.
By experimentally manipulating the presence of colonies of a native bumblebee species Bombus pauloensis in eight apple orchards in South Argentina, we evaluated the impact of losing natural populations of a key native pollinator group on (a) crop yield, (b) pollination quality, and (c) farmer's profit. To do so, we performed a factorial experiment of pollinator exclusion (yes/no) and hand pollination (yes/no).
Our results showed that biotic pollination increased ripe fruit set by 13% when compared to non‐biotic pollination. Additionally, fruit set and the number of fruits per apple tree was reduced by less than a half in those orchards where bumblebees were absent, even when honeybees were present at high densities. Consequently, farmer's profit was 2.4‐fold lower in farms lacking bumblebees than in farms hosting both pollinator species. The pollination experiment further suggested that the benefits of bumblebees could be mediated by improved pollen quality rather than quantity.
Synthesis and applications. This study highlights the pervasive consequences of losing key pollinator functional groups, such as bumblebees, for apple production and local economies. Adopting pollinator‐friendly practices such as minimizing the use of synthetic inputs or restoring/maintaining semi‐natural habitats at farm and landscape scales, will have the double advantage of promoting biodiversity conservation, and increasing crop productivity and profitability for local farmers. Yet because the implementation of these practices can take time to deliver results, the management of native pollinator species can be a provisional complementary strategy to increase economic profitability of apple growers in the short term.info:eu-repo/semantics/acceptedVersio
Extractos vegetales con actividad sobre cepas mutadas de saccharomyces cerevisiae con deficiencia en el mecanismo de reparacion del adn
Ciento treinta y ocho extractos obtenidos de plantas pertenecientes a las familias botánicas Asteraceae, Euphorbiaceae, Melastomataceae, Podocarpaceae, Rubiaceae y Solanaceae recolectadas en reservas naturales de la Ecorregión del Eje Cafetero (EEC) fueron evaluadas contra cepas de la levadura Saccharomyces cerevisiae RS 322N, R52Y y RS 321 por el método de difusión en agar, con el propósito de identificar nuevos extractos bioactivos que dañen el ADN y/o que inhiban las topoisomerasas I o II. Los extractos metanólicos de las especies pertenecientes a la familia Solanaceae: Browallia speciosa, Cestrum olivaceum y Solanum brevifolium mostraron selectividad para el ensayo de la levadura Saccharomyces cerevisiae mutada, presentando actividad como inhibidor de la topoisomerasa I. Adicionalmente, el extracto de diclorometano deSolanum deflexiflorum perteneciente a la misma familia presentó actividad inhibidora de la topoisomerasa II
Extractos vegetales con actividad sobre cepas mutadas de saccharomyces cerevisiae con deficiencia en el mecanismo de reparacion del adn
Ciento treinta y ocho extractos obtenidos de plantas pertenecientes a las familias botánicas Asteraceae, Euphorbiaceae, Melastomataceae, Podocarpaceae, Rubiaceae y Solanaceae recolectadas en reservas naturales de la Ecorregión del Eje Cafetero (EEC) fueron evaluadas contra cepas de la levadura Saccharomyces cerevisiae RS 322N, R52Y y RS 321 por el método de difusión en agar, con el propósito de identificar nuevos extractos bioactivos que dañen el ADN y/o que inhiban las topoisomerasas I o II. Los extractos metanólicos de las especies pertenecientes a la familia Solanaceae: Browallia speciosa, Cestrum olivaceum y Solanum brevifolium mostraron selectividad para el ensayo de la levadura Saccharomyces cerevisiae mutada, presentando actividad como inhibidor de la topoisomerasa I. Adicionalmente, el extracto de diclorometano deSolanum deflexiflorum perteneciente a la misma familia presentó actividad inhibidora de la topoisomerasa II
El primer año de la pandemia – ¿Qué hemos aprendido del SARS-CoV-2/COVID-19?
Editorial (no Summary)Editorial (Sin resumen
Infectious Diseases, Social, Economic and Political Crises, Anthropogenic Disasters and Beyond: Venezuela 2019 – Implications for Public Health and Travel Medicine
During last months, there have been a significant increase in the evidences showing the catastrophic health situation in Venezuela. There are multiple epidemics, increase in emerging and reemerging infectious, tropical and parasitic diseases as consequences of the social, economic and political crises, which would be considered today a clearly anthropogenic disaster. Venezuela is facing in 2019, the worse sanitary conditions, with multiple implications for public health and travel medicine. So far, from a global perspective, this situation will be an impediment for the achievement of the sustainable development goals (SDG) in 2030. In this multiauthor review, there is a comprehensive analysis of the situation for infectious diseases, non-communicable diseases, their impact in the Americas region, given the migration crisis as well as the comparative status of the SDG 2030. This discussion can provide input for prioritizing emerging health problems and establish a future agenda
Infectious Diseases, Social, Economic and Political Crises, Anthropogenic Disasters and Beyond: Venezuela 2019 – Implications for Public Health and Travel Medicine
During last months, there have been a significant increase in the evidences showing the catastrophic health situation in Venezuela. There are multiple epidemics, increase in emerging and reemerging infectious, tropical and parasitic diseases as consequences of the social, economic and political crises, which would be considered today a clearly anthropogenic disaster. Venezuela is facing in 2019, the worse sanitary conditions, with multiple implications for public health and travel medicine. So far, from a global perspective, this situation will be an impediment for the achievement of the sustainable development goals (SDG) in 2030. In this multiauthor review, there is a comprehensive analysis of the situation for infectious diseases, non-communicable diseases, their impact in the Americas region, given the migration crisis as well as the comparative status of the SDG 2030. This discussion can provide input for prioritizing emerging health problems and establish a future agenda
The effect of low-level laser irradiation (In-Ga-Al-AsP - 660 nm) on melanoma in vitro and in vivo
<p>Abstract</p> <p>Background</p> <p>It has been speculated that the biostimulatory effect of Low Level Laser Therapy could cause undesirable enhancement of tumor growth in neoplastic diseases. The aim of the present study is to analyze the behavior of melanoma cells (B16F10) <it>in vitro </it>and the <it>in vivo </it>development of melanoma in mice after laser irradiation.</p> <p>Methods</p> <p>We performed a controlled <it>in vitro </it>study on B16F10 melanoma cells to investigate cell viability and cell cycle changes by the Tripan Blue, MTT and cell quest histogram tests at 24, 48 and 72 h post irradiation. The <it>in vivo </it>mouse model (male Balb C, n = 21) of melanoma was used to analyze tumor volume and histological characteristics. Laser irradiation was performed three times (once a day for three consecutive days) with a 660 nm 50 mW CW laser, beam spot size 2 mm<sup>2</sup>, irradiance 2.5 W/cm<sup>2 </sup>and irradiation times of 60s (dose 150 J/cm<sup>2</sup>) and 420s (dose 1050 J/cm<sup>2</sup>) respectively.</p> <p>Results</p> <p>There were no statistically significant differences between the <it>in vitro </it>groups, except for an increase in the hypodiploid melanoma cells (8.48 ± 1.40% and 4.26 ± 0.60%) at 72 h post-irradiation. This cancer-protective effect was not reproduced in the <it>in vivo </it>experiment where outcome measures for the 150 J/cm<sup>2 </sup>dose group were not significantly different from controls. For the 1050 J/cm<sup>2 </sup>dose group, there were significant increases in tumor volume, blood vessels and cell abnormalities compared to the other groups.</p> <p>Conclusion</p> <p>LLLT Irradiation should be avoided over melanomas as the combination of high irradiance (2.5 W/cm<sup>2</sup>) and high dose (1050 J/cm<sup>2</sup>) significantly increases melanoma tumor growth <it>in vivo</it>.</p
Influenza Activity and Composition of the 2022-23 Influenza Vaccine - United States, 2021-22 Season
Before the emergence of SARS-CoV-2, the virus that causes COVID-19, influenza activity in the United States typically began to increase in the fall and peaked in February. During the 2021-22 season, influenza activity began to increase in November and remained elevated until mid-June, featuring two distinct waves, with A(H3N2) viruses predominating for the entire season. This report summarizes influenza activity during October 3, 2021-June 11, 2022, in the United States and describes the composition of the Northern Hemisphere 2022-23 influenza vaccine. Although influenza activity is decreasing and circulation during summer is typically low, remaining vigilant for influenza infections, performing testing for seasonal influenza viruses, and monitoring for novel influenza A virus infections are important. An outbreak of highly pathogenic avian influenza A(H5N1) is ongoing; health care providers and persons with exposure to sick or infected birds should remain vigilant for onset of symptoms consistent with influenza. Receiving a seasonal influenza vaccine each year remains the best way to protect against seasonal influenza and its potentially severe consequences
- …