675 research outputs found
Characteristics of Staphylococcus aureus infections to consider in designing an effective vaccine.
_Staphylococcus aureus_ is a very versatile and adaptable microorganism. It can potentially infect virtually any host tissue. Given the appropriate conditions it can become a life-threatening pathogen, or a commensal colonizer of the nose. Extensive antibiotic use for infection control facilitated the rise of antibiotic resistance, stressing the need for alternate forms of control. Vaccine efforts in other pathogens have proved successful, but so far _S. aureus_ candidate vaccines have not been as effective. Here we review _S. aureus_ factors involved in pathogenesis that could help develop a successful vaccine, like host nasal colonization and immune evasion factors. An effective multicomponent vaccine could incorporate antigenic fragments from several _S. aureus_ proteins, preferably involved in colonization, immune evasion and/or toxicity
Assessment of potential prebiotic activity of pineapple by-products (peels and stems) extracts and maintenance of bioavailability through in vitro gastrointestinal tract system
N/
Sex-partitioning of the <i>Plasmodium falciparum</i> stage V gametocyte proteome provides insight into <i>falciparum</i>-specific cell biology
One of the critical gaps in malaria transmission biology and surveillance is our lack of knowledge about Plasmodium falciparum gametocyte biology, especially sexual dimorphic development and how sex ratios that may influence transmission from the human to the mosquito. Dissecting this process has been hampered by the lack of sex-specific protein markers for the circulating, mature stage V gametocytes. The current evidence suggests a high degree of conservation in gametocyte gene complement across Plasmodium, and therefore presumably for sex-specific genes as well. To better our understanding of gametocyte development and subsequent infectiousness to mosquitoes, we undertook a Systematic Subtractive Bioinformatic analysis (filtering) approach to identify sex-specific P. falciparum NF54 protein markers based on a comparison with the Dd2 strain, which is defective in producing males, and with syntenic male and female proteins from the reanalyzed and updated P. berghei (related rodent malaria parasite) gametocyte proteomes. This produced a short list of 174 male- and 258 female-enriched P. falciparum stage V proteins, some of which appear to be under strong diversifying selection, suggesting ongoing adaptation to mosquito vector species. We generated antibodies against three putative female-specific gametocyte stage V proteins in P. falciparum and confirmed either conserved sex-specificity or the lack of cross-species sex-partitioning. Finally, our study provides not only an additional resource for mass spectrometry-derived evidence for gametocyte proteins but also lays down the foundation for rational screening and development of novel sex-partitioned protein biomarkers and transmission-blocking vaccine candidates
Determinantes de intensidad administrativa en los Centros Públicos de Investigación: análisis longitudinal
La intensidad administrativa se ha tratado en la literatura como un concepto unidimensional determinado por el tamaño de la organización. En este trabajo se considera que la intensidad administrativa es multidimensional ya que existen diferentes variables que la determinan. Se utilizó una metodología cuantitativa longitudinal a través de datos de panel (2010-2020) correspondiente a los Centros Públicos de Investigación. Esta investigación se centró en tres aspectos sobre la intensidad administrativa: primero, se analizó a través de regresión lineal si las medidas de razón de la intensidad administrativa y el tamaño de la organización distorsionan o sesgan los resultados para analizar las economías de escala administrativa, además se probó que estas medidas de razón tienen implicaciones correctas y apoyan la teoría de economías de escala administrativa relacionada con el tamaño de la organización, segundo, se identificaron los efectos de tres determinantes de la intensidad administrativa (tamaño de la organización, diferenciación funcional y especialización). El tamaño tuvo un efecto negativo en la intensidad administrativa pero al agregar el término cuadrático a la variable de tamaño se observó una relación no lineal. La diferenciación funcional tuvo un efecto positivo sobre la intensidad administrativa. La relación entre la intensidad administrativa y especialización fue positiva, y tercero, la intensidad administrativa tuvo un efecto positivo en la productividad. Esta investigación muestra evidencia empírica con implicaciones prácticas para las políticas organizacionales de los Centros Públicos de Investigación
Camel genetic resources conservation through tourism: A key sociocultural approach of camelback leisure riding
Camels are exotic elements, which can be comprised within adventure travel companies promoting ecotourism activities. Such recreations contribute to sustainable livelihoods for local communities and educational empowerment towards nature and its conservation. At present, some local camel breeds’ survival reduces to this animal-based leisure industry and its reliability to perform and promote customized services accurately. By conducting an on-site questionnaire to customers participating in camelback riding tours, we assessed the motivational factors affecting participation, satisfaction, and loyalty in this tourism segment that may have made it socially differentiated. The sixfold combination of staff performance, culture geography, diverse and humane close interaction, camel behavior and performance, sociotemporal context, and positive previous experience involves the elemental dimensions that explain customer satisfaction and return intention probability within this entertainment business. Customer knowledge is essential for stakeholders to build personalized riding experiences and align profits with environmental sustainability and biodiversity mainstream concerns into their everyday operations. In turn, domestic camel tourist rides could be managed as a viable path to nature conservation by helping endangered local breeds to avoid their functional devaluation and potential extinction
Effect of research impact on emerging camel husbandry, welfare and social-related awareness
The lack of applied scientific research on camels, despite them being recognized as production animals, compels the reorganization of emerging camel breeding systems with the aim of achieving successful camel welfare management strategies all over the world. Relevant and properly-framed research widely impacts dissemination of scientific contents and drives public willingness to enhance ethically acceptable conditions for domestic animals. Consumer perception of this livestock industry will improve and high-quality products will be obtained. This paper draws on bibliometric indicators as promoting factors for camel-related research advances, tracing historical scientific publications indexed in ScienceDirect directory from 1880–2019. Camel as a species did not affect Journal Citation Reports (JCR) impact (p > 0.05) despite the journal, author number, corresponding author origin, discipline and publication year affecting it (p < 0.001). Countries with traditionally well-established camel farming are also responsible for the papers with the highest academic impact. However, camel research advances may have only locally and partially influenced welfare related laws, so intentional harming acts and basic needs neglect may persist in these species. A sustainable camel industry requires those involved in camel research to influence business stakeholders and animal welfare advocacies by highlighting the benefits of camel wellbeing promotion, co-innovation partnership establishment and urgent enhancement of policy reform
Síntesis y evaluación citotoxica de derivados halogenados y peracetylados de nucleósidos en celulas de cancer de mama
Objectives. To make the synthesis of halogenated derivatives on the nitrogenous base and their respective acyl ester and amide type derivatives for all hydroxyl and amine groups of the uridine and cytarabine nucleosides, and evaluate cytotoxicity against breast cancer cell line. Methods. First, it was accomplished the halogenation reaction on the 5-position of the nitrogenous base, subsequently, the ester and amide derivatives were performed for all hydroxyl and amine group present in the nucleosides. Besides, the uridine acetonide derivatives as prepared by acid catalysis. The products were characterized by nuclear magnetic resonance spectroscopy (1H RMN y 13C RMN) and mass spectrometry in positive mode by direct injection. Derivatives were evaluated in Chinese hamster ovary (CHO-K1) and human breast cancer (MCF-7) cell lines. Results. The four derivatives were obtained with chlorine and bromine for the uridine and cytarabine, respectively, their respective per-acetylated derivatives, the per-acetylated nucleoside and the uridine acetonide; the compounds were obtained with efficiency over 90%. The per-acetylated nucleosides and the halogenated and per-acetylated derivatives did not show inhibitory effects on cell viability in MCF-7 cell line. However, the per-acetylated and halogenated derivatives presented a higher cytotoxic activity than their respective per-acetylated nucleoside. The uridine 3’,4’-acetonide showed a significant cytotoxicity on both cell lines. Conclusions. The per-acetylated nucleoside, and the respective halogenated derivatives with chlorine and bromine were obtained with high yields, nevertheless, these compounds did not exhibit a significant anti-proliferative activity (p˂0.05), possibly due to a low intra-cellular activation.Objetivos: Sintetizar derivados halogenados sobre la base nitrogenada, sus respectivos derivados tipo éster o amida de todos los grupos hidroxilo y amina presentes en los nucleósidos uridina y citarabina, y evaluar su actividad citotóxica sobre una línea celular de cáncer de mama. Metodología: primero se realizó la reacción de halogenación en la posición 5 de la base nitrogenada, posteriormente se formaron los ésteres y amidas de todos los grupos hidroxilos y amino presentes en los nucleósidos. Además, se preparó el derivado acetónido con catálisis ácida. Los compuestos se caracterizaron por espectroscopía de resonancia magnética nuclear (RMN 1H y RMN 13C) y espectrometría de masas por inyección directa en modo positivo. Los derivados se evaluaron sobre líneas celulares de tumor de Ovario de Hámster Chino (CHO) y de cáncer de mamá (MCF-7). Resultados: Se obtuvieron 4 derivados mono-halogenados con cloro y bromo de la uridina y citarabina, respectivamente, sus respectivos derivados per-acetilados, los nucleósidos per-acetilados y el acetónido de la uridina; los compuestos se obtuvieron con rendimientos superiores a 90%. Los nucleósidos per-acetilados, y los derivados per-acetilados y halogenados no exhibieron una inhibición significativa de la viabilidad celular en ambas líneas celulares, sin embargo, de estos, los derivados per-acetilados y halogenados presentaron mayor actividad citotóxica que los respectivos nucleósidos per-acetilados. El derivado acetónido de la uridina mostró citotoxicidad significativa sobre ambas líneas celulares. Conclusiones: se obtuvieron los nucleósidos per-acetilados y los respectivos derivados clorados y bromados de estos, con rendimientos altos, sin embargo, estos compuestos no exhibieron una actividad anti-proliferativa significativa (p˂0,05), posiblemente debido a una baja activación intra-celular de los nucleósidos
Importancia dopaminérgica en farmacodinamia de cocaína evaluada por alteraciones de GABA y glutamato en el núcleo accumbens de ratas
The aim of the present study was to investigate the role of dopamine in cocaine pharmacodynamics in rats. To test this hypothesis, we measured GABA and glutamate level changes in the accumbens nucleus. This approach is supported by the preponderance of evidence which has consistently shown alterations in dopaminergic activity after cocaine administration. Furthermore, GABA and glutamate have considerable irnportance in cocaine's acute and chronic effects. The relationship between GABA and glutamate with dopaminergic activity in the nucleus accumbens is well-known. A 16-day study was designed for the administration of cocaine chlorhydrate (IP) at 30 mglkglday increasing by 5 mglkglday each 4 days to animals which had been stereotaxically injured in the nucleus accumbens with 6-OH-dopamine (6-OHDA) neurotoxin dissolved in ascorbic acid. A base group was formed which received ascorbic acid diluted in 0.9% saline solution stereotaxically in the nucleus accumbens, and was treated with an equal volume of 0.9% saline solution (IP). The control group received 6- OHDA (diluted in ascorbic acid) stereotaxically in the nucleus accumbens and was given 0.9% saline solution as treatment. GABA and glutamate levels were determined by enzymatic assays. The results of this work show a significant decrease of GABA levels in the group that received chronic cocaine administration in comparison to the base and control group. Glutamate levels were significantly higher in the cocaine group than in the base group, but not significantly different from the control group. In conclusion, the results of the present work suppofi the idea of the great irnportance of dopaminergic activity in cocaine pharmacotherapy. This dopamine role could be either through GABA or glutamate level alterations or both. Direct action of increased cocaine level on the so-called reward system could be another explication.Este trabajo se propuso demostrar la importancia del sistema dopaminérgico en la farmacodinamia de cocaína en el SNC de ratas. Este postulado se verificó evaluando las alteraciones de GABA y glutamato en el núcleo accumbens. Este enfoque se sustenta en la gran cantidad de evidencias que muestran, consistentemente alteraciones en la actividad dopaminérgica por cocaína. Además, el GABA y el glutamato tienen gran importancia en los efectos agudos y crónicos por cocaína. Es bien conocida la interrelación de GABA y glutamato con la actividad dopaminérgica en el núcleo accumbens. Se diseñó un estudio por 16 días de administración de cocaína a ratas a la dosis inicial de 30 mglkgldía (IP) con incremento de 5 mglkg cada 4 días, a las cuales se les había lesionado la actividad dopaminérgica en el núcleo accumbens con la neurotoxina 6- hidroxidopamina en ácido ascórbico. Además, se conformó un grupo basal que recibió estereotáxicamante, en el núcleo accumbens, ácido ascórbico en solución salina 0,9% y se trató con un volumen correspondiente de solución salina (IP) y, un grupo control, al cual estereotáxicamente, en el núcleo mencionado, se le administró 6-OHDA (en ácido ascórbico), recibiendo posteriormente como tratamiento solución salina (IP). La determinación de los niveles de GABA y glutamato se realizó por métodos enzimáticos. Se observó que la administración crónica de cocaína produce una disminución significativa en el nivel de GABA en el núcleo accumbens del grupo problema, con relación a los grupos basal y control. En tanto, el nivel de glutamato en el grupo problema mostró un incremento significativo con relación al grupo basal, pero, no con relación al grupo control. En conclusión, los resultados de este trabajo sostienen la hipótesis del papel importante que tiene la dopamina en la farmacoterapia de cocaína a través de las alteraciones en los niveles de GABA y glutamato o alteraciones en forma directa. Además, la cocaína podría alterar por sí misma la actividad gabaérgica y glutaérgica
Evaluación piloto de una escala de clasificación audiométrica de HNIR, aplicable a los programas de vigilancia epidemiológica
Objective: Apply a pilot evaluation of a hybrid method between the frequency description and the modified Klochoff scale.
Methodology: Five categories were defined and their respective epidemiological actions based on the GATISO-HNIR were defined: Normal, Grade 1, Grade 2, Grade 3 and Non-HNIR. This scale was applied to 791 workers.
Results: Most workers were classified as Normal (666) and 18 as Non-HNIR. The rest were distributed as follows: 77 workers with Grade 1 HNIR, 8 with Grade 2 HNIR and 22 with Grade 3. The proposed scale was practical, precise, articulated with epidemiological actions and is consistent with Colombian legislation.
Conclusions: This proposal is delivered to the community involved in attention to noise exposure to be evaluated and considered as a tool in the classification of HNIR at the workplace level.Objetivo: Aplicar una evaluación piloto de un método híbrido entre la descripción frecuencial y la escala de Klochoff modificada.
Metodología: Se definieron cinco categorías y se definieron sus respectivas acciones epidemiológicas con base en la GATISO-HNIR: Normal, Grado 1, Grado 2, Grado 3 y No-HNIR. Esta escala se aplicó a 791 trabajadores.
Resultados: La mayoría de trabajadores fueron clasificados como Normal (666) y 18 cmo No-HNIR. El resto se distribuyeron así: 77 trabajadores con HNIR Grado 1, 8 con HNIR Grado 2 y 22 con Grado 3. La escala propuesta fue práctica, precisa, se articula con acciones epidemiológicas y es coherente con la legislación colombiana.
Conclusiones: Se entrega esta propuesta a la comunidad involucrada en atención a expuestos a ruido para ser evaluada y considerada como herramienta en la clasificación de HNIR a nivel laboral
Benefit of double-reading cytology smears as a triage strategy among high-risk human papillomavirus-positive women in Mexico
- …