Differential expression of mast cell granules in samples of metastatic and non-metastatic colorectal cancer in patients.

Various cell types participate in the tumor process, in which the mast cells have been described; however, the role they play in colorectal adenocarcinoma has not yet been fully understood. Therefore, the present work aimed to compare employing histochemistry and immunohistochemistry, the number of mast cells and the content of some cytoplasmic granules in moderately differentiated non-metastatic and metastatic colorectal adenocarcinoma, analyzing tissue samples from patients. Histochemical techniques with Toluidine Blue (TBO), Periodic Schiff Acid (PAS), Alcian Blue/Periodic Acid-Schiff (PAB) and Alcian Blue/Safranin (ABS); as well as immunohistochemical reactions with anti-antibodies anti-Tryptase and anti-Chymase were applied to quantify total mast cells and content of some cytoplasmic granules. Statistical analysis was performed using SPSS V22.0 software (p ≤ 0.05). The degree of positivity of the reaction and degranulation of mast cells was reported in percentages. In our results, we observed that there are differences in the quantity and histochemical composition of the granules of mast cells (metastatic group PAS and ABS comparing the TBO reaction), as well as in the immunohistochemical composition between Tryptase and Chymase and the number of degranulated cells in both study groups (74 % degranulated mast cells in the metastatic group, 66 % integrate mast cells in the non-metastatic group). Therefore, we consider that the differences may be some of the probable factors that lead to metastasis of colorectal adenocarcinoma.

Effect of the Generation of PAMAM Dendrimers on the Stabilization of Gold Nanoparticles.

The behavior of small and intermediate generations of poly(amidoamine) (PAMAM) dendrimers and PAMAM|gold nanocomposites was studied by computational tools and experimental techniques. Molecular dynamics simulations were used to characterize at the atomic level the stabilization mechanism of gold nanoparticles by dendrimeric platforms. Low PAMAM generations create a stabilization sphere around the nanoparticle, while upper PAMAM sizes provide stabilization sites through the internal voids. These results can help in the understanding of the stabilization process of metallic nanoparticles for the design and contribution of new nanotechnological applications.

Thermal stability analyses of human PERIOD-2 C-terminal domain using dynamic light scattering and circular dichroism.

At the molecular level, the circadian clock is regulated by a time delayed transcriptional-translational feedback loop in which the core proteins interact with each other rhythmically to drive daily biological rhythms. The C-terminal domain of a key clock protein PER2 (PER2c) plays a critically important role in the loop, not only for its interaction with the binding partner CRY proteins but also for the CRY/PER complex's translocation from the cytosol to the nucleus. Previous circular dichroism (CD) spectroscopic studies have shown that mouse PER2c (mPER2c) is less structured in solution by itself but folded into stable secondary structures upon interaction with mouse CRYs. To understand the stability and folding of human PER2c (hPER2c), we expressed and purified hPER2c. Three oligomerization forms of recombinant hPER2c were identified and thoroughly characterized through a combination of biochemical and biophysical techniques. Different to mPER2c, both thermal unfolding DLS and CD analyses suggested that all forms of hPER2c have very stable secondary structures in solution by themselves with melting temperatures higher than the physiological body temperature, indicating that hPER2c does not require CRY to fold. Furthermore, we examined the effects of EDTA, salt concentration, and a reducing agent on hPER2c folding and oligomerization. The ability of hPER2c forming oligomers reflects the potential role of hPER2c in the assembly of circadian rhythm core protein complexes.

Nanohybrids of reduced graphene oxide and cobalt hydroxide (Co(OH)2|rGO) for the thermal decomposition of ammonium perchlorate.

The catalytic activity of nanoparticles of cobalt hydroxide supported on reduced graphene oxide, Co(OH)2|rGO, was studied for the decomposition of ammonium perchlorate (AP), the principal ingredient of composite solid propellants. Co(OH)2|rGO was synthesized by an in situ reduction method, which avoided the application of extremely high temperatures and harsh processes. rGO stabilized the nanoparticles effectively and prevented their agglomeration. The performance of Co(OH)2|rGO as a catalyst was measured by differential scanning calorimetry. Co(OH)2|rGO affected the high-temperature decomposition (HTD) of AP positively, decreasing the decomposition temperature of AP to 292 °C, and increasing the energy release to 290 J g-1. The diminution of the HTD of AP by Co(OH)2|rGO is in between the best values reported to date, suggesting its potential application as a catalyst for AP decomposition.

Evaluación de la respuesta inflamatoria en ratas Wistar a TheraCalTM LC implantado vía subcutánea / Evaluation of the inflammatory response in Wistar rats to TheraCalTM LC implanted subcutaneously

El Theracal TM LC es un cemento silicato de calcio (Ca) modificado con resina (SMCR) que ha demostrado ser un material ideal para el tratamiento dentino-pulpar por su alta tasa de formación de calcio. Los biomateriales por su contenido de Ca tienden a tener un aumento en su biodisponibilidad, estimulando la formación del puente dentario atreves de las células involucradas en la formación de tejidos mineralizados, promoviendo la diferenciación de fibroblastos en odontoblastos y aumentando la actividad de la enzima pirofostasa responsable en la mineralización de la dentina. El presente estudio con el objetivo de evaluar la respuesta inflamatoria a Theracal TM LC subcutáneamente en ratas Wistar. Fueron usados seis ratas cepa Wistar en las cuales se realizaron cuatro bolsillos quirúrgicos subcutáneos. Cada uno de estos bolsillos se determinó como cuadrante distinto, conteniendo los siguientes implantes: 1 Theracal TM LC en tubo polietileno, 2 tubo de polietileno, 3 Theracal TM LC directo y 4 como control. Las muestras histológicas se procesaron y se evaluaron distintos tipos celulares mediante conteo a microscopio de luz a 100X utilizando las tinciones H&E y AT pH 2.3. Los resultados mostraron que existen diferencias significativas en todos los tipos celulares observados durante los diferentes tiempos de exposición. Las diferencias en los tipos celulares observados podrían ser debido al tiempo de exposición al Theracal TM LC, al tubo polietileno y a ambos. El tejido evaluado del implante del tubo polietileno y al tubo polietileno con Theracal TM LC, presentan mayor respuesta inflamatoria, a diferencia en el tejido implantado con Theracal TM LC directamente.

TheraCalTM LC is a resin-modified calcium silicate (Ca) resin (SMCR) that has proven to be an ideal material for dentin-pulp treatment due to its high rate of calcium formation. Biomaterials due to their Ca content tend to have an increase in their bioavailability, stimulating the formation of the dental bridge through the cells involved in the formation of mineralized tissues, promoting the differentiation of fibroblasts in odontoblasts and increasing the activity of the pyrophosphate enzyme responsible in dentin mineralization. The present study aimed to evaluate the inflammatory response to TheracalTM LC subcutaneously in Wistar rats. Six Wistar strain rats were used in which four subcutaneous surgical pockets were made. Each of these pockets was determined as a different quadrant, containing the following implants: 1 TheracalTM LC in polyethylene tube, 2 polyethylene tubes, 3 TheracalTM LC direct and 4 as control. The histological samples were processed, and different cell types were evaluated by light microscopy at 100X using the H&E and AT pH 2.3 stains. The results showed that there are significant differences in all cell types observed during the different exposure times. The differences in the cell types observed could be due to the exposure time to TheracalTM LC, to the polyethylene tube and to both. The evaluated tissue of the polyethylene tube implant and the polyethylene tube with TheracalTM LC present a greater inflammatory response, unlike in the tissue implanted with TheracalTM LC directly.

Novel in situ synthesis of copper nanoparticles supported on reduced graphene oxide and its application as a new catalyst for the decomposition of composite solid propellants.

The catalytic activity of graphene oxide (GO), reduced graphene oxide (rGO), copper nanoparticles (CuNP) and rGO supported copper nanoparticles (rGO|CuNP) was investigated for the thermal decomposition of ammonium perchlorate (AP). GO was synthesized using a methodology based on hydrophilic oxidation, while an environmentally friendly and non-toxic reducing agent, l-ascorbic acid, was applied for the in situ reduction of copper and GO. The supporting rGO reduced the mean size of the copper nanoparticles from approximately 6 to 2 Å due to the presence of stabilizing functional groups on the graphitic structure. Theoretical studies through Density Functional Theory revealed the important role of the epoxy and carbonyl groups of rGO on the stabilization of copper. The thermal decomposition process was studied based on DSC and TGA. GO, and rGO did not show a significant catalytic influence in the decomposition of AP. CuNP reduced the decomposition temperature of AP in greater magnitude than rGO|CuNP however, the synergistic effect of the rGO and CuNP increased the energy release significantly.

Graphene Oxide Quantum Dots as the Support for the Synthesis of Gold Nanoparticles and Their Applications as New Catalysts for the Decomposition of Composite Solid Propellants.

Graphene oxide quantum dot (GOQD) and reduced GOOD (rGOQD) were synthetized using a simple and straight methodology based on an oxidative treatment and sonication. GOQD and rGOQD were used as supporting agents for the in situ generation of gold nanoparticles, avoiding the use of additional stabilizers. GOQD resulted as a better support than rGOQD because of the presence of higher functional groups that can interact with gold. Theoretical studies through density functional theory revealed the important role of the epoxy groups of GOQD on the stabilization of gold. GOQD and GOQD-Au were tested for the first time as catalysts for the decomposition of solid composite propellants. GOQD not only lowered the decomposition temperature of ammonium perchlorate (AP) but also enhanced the exothermic heat of AP, in comparison to graphene and GO. GOQD-Au increased the energy release; however, the effect on the decrease of the decomposition temperature of AP was not as significant as other previous reported catalysts.

[Active community case-finding for uptake of pregnant and postpartum women in Ecuador]. / Método de búsqueda activa comunitaria para la captación de gestantes y puérperas en Ecuador.

OBJECTIVE: Document and analyze Ecuador's experience using active community case-finding for uptake of pregnant and postpartum women in Ecuador. METHODS: A cross-sectional descriptive study was conducted of information obtained on active community case-finding of pregnant and postpartum women in the catchment areas of 200 primary care facilities of Ecuador's Ministry of Public Health. RESULTS: Visits were made to 460 451 homes in 20 provinces; 15 622 pregnant women and 4 014 postpartum women were identified. Of the pregnant women, 89% (13 875) had had at least one prenatal check-up, while 70% of postpartum women (4 014) had had at least one post-delivery or post-caesarean check-up. Potential risk was identified in 29% of pregnant women (4 601). Orellana and Sucumbíos provinces had the lowest percentages of pregnant women with at least one prenatal check-up and the lowest percentages of postpartum women with at least one postpartum checkup. A total of 3 951 brigades were formed at the national level for this activity. CONCLUSIONS: Active community case-finding was valuable in identifying pregnant and postpartum women who had not been captured by the health system, especially to detect their risk status, in addition to the advantages of participatory uptake, especially with support from universities with health majors. Low coverage for postpartum check-ups underscores the importance of learning why women do not receive this care. Similar experiences need to be systematized to improve the process.

Método de búsqueda activa comunitaria para la captación de gestantes y puérperas en Ecuador / Active community case-finding for uptake of pregnant and postpartum women in Ecuador

Objetivo. Documentar y analizar la experiencia ecuatoriana en la aplicación del método de Búsqueda Activa Comunitaria (BAC) en la captación de mujeres gestantes y puérperas en Ecuador. Métodos. Se realizó un estudio descriptivo transversal de la información obtenida de la aplicación de la BAC de mujeres gestantes y puérperas en las áreas de influencia geográfica de 200 establecimientos de atención primaria del Ministerio de Salud Pública de Ecuador. Resultados. Se visitaron 460.451 casas en 20 provincias. Se identificaron 15.622 embarazadas y 4.014 puérperas. El 89% (13.875) de las embarazadas identificadas se había sometido al menos a un control prenatal y 70% (4 014) de las puérperas identificadas, al menos a un control posterior a su parto o cesárea. El 29% de las embarazadas (4 601) identificadas tenían riesgo potencial. Orellana y Sucumbíos fueron las provincias con menor porcentaje de embarazadas con al menos un control prenatal y con el menor porcentaje de puérperas con al menos un control postparto. Para esta actividad se conformó un total de 3 951 brigadas a nivel nacional. Conclusiones. El método de BAC fue valioso para identificar embarazadas y puérperas que no habían sido captadas por el sistema de salud, y especialmente detectar su situación de riesgo, además de las ventajas del trabajo participativo en el proceso de captación, sobre todo con el apoyo de universidades con carreras vinculadas con la salud. Las bajas coberturas de control de puérperas señalan la importancia de conocer las causas de la falta de adherencia a estos controles. Se requiere sistematizar experiencias similares para introducir mejoras en el procedimiento.

Objective. Document and analyze Ecuador’s experience using active community case-finding for uptake of pregnant and postpartum women in Ecuador. Methods. A cross-sectional descriptive study was conducted of information obtained on active community case-finding of pregnant and postpartum women in the catchment areas of 200 primary care facilities of Ecuador’s Ministry of Public Health. Results. Visits were made to 460 451 homes in 20 provinces; 15 622 pregnant women and 4 014 postpartum women were identified. Of the pregnant women, 89% (13 875) had had at least one prenatal check-up, while 70% of postpartum women (4 014) had had at least one post-delivery or post-caesarean check-up. Potential risk was identified in 29% of pregnant women (4 601). Orellana and Sucumbíos provinces had the lowest percentages of pregnant women with at least one prenatal check-up and the lowest percentages of postpartum women with at least one postpartum checkup. A total of 3 951 brigades were formed at the national level for this activity. Conclusions. Active community case-finding was valuable in identifying pregnant and postpartum women who had not been captured by the health system, especially to detect their risk status, in addition to the advantages of participatory uptake, especially with support from universities with health majors. Low coverage for postpartum check-ups underscores the importance of learning why women do not receive this care. Similar experiences need to be systematized to improve the process.

Método de búsqueda activa comunitaria para la captación de gestantes y puérperas en Ecuador / Active community case-finding for uptake of pregnant and postpartum women in Ecuador

RESUMEN Objetivo Documentar y analizar la experiencia ecuatoriana en la aplicación del método de Búsqueda Activa Comunitaria (BAC) en la captación de mujeres gestantes y puérperas en Ecuador. Métodos Se realizó un estudio descriptivo transversal de la información obtenida de la aplicación de la BAC de mujeres gestantes y puérperas en las áreas de influencia geográfica de 200 establecimientos de atención primaria del Ministerio de Salud Pública de Ecuador. Resultados Se visitaron 460.451 casas en 20 provincias. Se identificaron 15.622 embarazadas y 4.014 puérperas. El 89% (13.875) de las embarazadas identificadas se había sometido al menos a un control prenatal y 70% (4 014) de las puérperas identificadas, al menos a un control posterior a su parto o cesárea. El 29% de las embarazadas (4 601) identificadas tenían riesgo potencial. Orellana y Sucumbíos fueron las provincias con menor porcentaje de embarazadas con al menos un control prenatal y con el menor porcentaje de puérperas con al menos un control postparto. Para esta actividad se conformó un total de 3 951 brigadas a nivel nacional. Conclusiones El método de BAC fue valioso para identificar embarazadas y puérperas que no habían sido captadas por el sistema de salud, y especialmente detectar su situación de riesgo, además de las ventajas del trabajo participativo en el proceso de captación, sobre todo con el apoyo de universidades con carreras vinculadas con la salud. Las bajas coberturas de control de puérperas señalan la importancia de conocer las causas de la falta de adherencia a estos controles. Se requiere sistematizar experiencias similares para introducir mejoras en el procedimiento.

ABSTRACT Objective Document and analyze Ecuador’s experience using active community case-finding for uptake of pregnant and postpartum women in Ecuador. Methods A cross-sectional descriptive study was conducted of information obtained on active community case-finding of pregnant and postpartum women in the catchment areas of 200 primary care facilities of Ecuador’s Ministry of Public Health. Results Visits were made to 460 451 homes in 20 provinces; 15 622 pregnant women and 4 014 postpartum women were identified. Of the pregnant women, 89% (13 875) had had at least one prenatal check-up, while 70% of postpartum women (4 014) had had at least one post-delivery or post-caesarean check-up. Potential risk was identified in 29% of pregnant women (4 601). Orellana and Sucumbíos provinces had the lowest percentages of pregnant women with at least one prenatal check-up and the lowest percentages of postpartum women with at least one postpartum checkup. A total of 3 951 brigades were formed at the national level for this activity. Conclusions Active community case-finding was valuable in identifying pregnant and postpartum women who had not been captured by the health system, especially to detect their risk status, in addition to the advantages of participatory uptake, especially with support from universities with health majors. Low coverage for postpartum check-ups underscores the importance of learning why women do not receive this care. Similar experiences need to be systematized to improve the process.

Evaluación de la sensibilidad diagnóstica de tres técnicas de laboratorio para la infección por influenza A: inmunocromatografía, IFD e IFD con citocentrifugado versus RPC-TR / Evaluation of three laboratory methods diagnostic sensitivity in influenza A infection: RIDT, DFA and DFA with cytocentrifugation versus RT-PCR

Introduction: The specific diagnosis of influenza A infection makes it possible to control its spread, decreases the unnecessary use of antibiotics, clinical procedures and laboratory test, and allows early recognition of outbreaks. Different technologies are currently available in Chile for this purpose. Objective: The study presented here compares the sensitivity for influenza A virus detection of immunocromatography (RIDT), direct fluorescent antibodies-DFA and DFA with cytocentrifugation against the gold standard, RT-PCR. Material and Methods: In 175 nasal swab samples influenza A RIDT and RT-PCR were performed. Another 1689 nasal swab samples were tested by DFA and RT-PCR for influenza A. Finally, 29 nasal swab samples confirmed as Influenza A positive by RT-PCR were tested by DFA with cytocentrifugation. Results: The RIDT, DFA and DFA + cytocentrifugation sensitivity was 47,3%, 57,2% and 72,4%, respectively. Discussion and Conclusion: Their lower cost and faster turnaround time when compared to PCR make RIDT and DFA the tests of choice in diagnostic laboratories in Chile. However, their low sensitivity and NPV, especially during low season, makes more sensitive diagnostic tools necessary to confirm the results. In our study cytocentrifugation increased DFA sensitivity from 57% to 72%.

Introducción: El diagnóstico específico de influenza permite controlar la diseminación de la enfermedad, disminuir el uso de antimicrobianos, procedimientos clínicos y exámenes, e identificar rápidamente brotes. Diferentes tecnologías están actualmente disponibles en Chile para este propósito. Objetivo: Comparar la sensibilidad diagnóstica para la infección por el virus influenza A de las técnicas inmunocromatografía, inmunofluorescencia directa-IFD e IFD con citocentrifugado contra el estándar de oro, RPC-TR. Materiales y Método: En 175 muestras de hisopado nasofaríngeo se realizó inmunocromatografía y RPC-TR para influenza A. Otras 1.689 muestras de hisopado nasofaríngeo fueron procesadas mediante IFD y RPC-TR para influenza A. Finalmente, en 29 muestras de hisopado nasofaríngeo, confirmadas positivas para influenza A mediante RPC-TR, se realizó IFD con citocentrifugado. Resultados: La sensibilidad de la inmunocromatografía, IFD e IFD + citocentrifugado fue de 47,3%, 57,2% y 72,4%, respectivamente. Discusión y Conclusión: El menor costo y tiempo de respuesta de las técnicas rápidas (inmunocomatografía e IFD) en relación a la RPC-TR hacen que se mantengan como exámenes de rutina en los laboratorios diagnósticos del país. Sin embargo, su baja sensibilidad y VPN, especialmente durante períodos de baja prevalencia, obligaría a confirmar los resultados negativos con técnicas más sensibles. En nuestra comparación la citocentrifugación mejoró la sensibilidad de la IFD de 57% a 72%.

[Evaluation of three laboratory methods diagnostic sensitivity in influenza A infection: RIDT, DFA and DFA with cytocentrifugation versus RT-PCR]. / Evaluación de la sensibilidad diagnóstica de tres técnicas de laboratorio para la infección por influenza A: inmunocromatografía, IFD e IFD con citocentrifugado versus RPC-TR.

INTRODUCTION: The specific diagnosis of influenza A infection makes it possible to control its spread, decreases the unnecessary use of antibiotics, clinical procedures and laboratory test, and allows early recognition of outbreaks. Different technologies are currently available in Chile for this purpose. OBJECTIVE: The study presented here compares the sensitivity for influenza A virus detection of immunocromatography (RIDT), direct fluorescent antibodies-DFA and DFA with cytocentrifugation against the gold standard, RT-PCR. MATERIAL AND METHODS: In 175 nasal swab samples influenza A RIDT and RT-PCR were performed. Another 1689 nasal swab samples were tested by DFA and RT-PCR for influenza A. Finally, 29 nasal swab samples confirmed as Influenza A positive by RT-PCR were tested by DFA with cytocentrifugation. RESULTS: The RIDT, DFA and DFA + cytocentrifugation sensitivity was 47,3%, 57,2% and 72,4%, respectively. DISCUSSION AND CONCLUSION: Their lower cost and faster turnaround time when compared to PCR make RIDT and DFA the tests of choice in diagnostic laboratories in Chile. However, their low sensitivity and NPV, especially during low season, makes more sensitive diagnostic tools necessary to confirm the results. In our study cytocentrifugation increased DFA sensitivity from 57% to 72%.

Hydrogen bond contribution to preferential solvation in S(N)Ar reactions.

Preferential solvation in aromatic nucleophilic substitution reactions is discussed using a kinetic study complemented with quantum chemical calculations. The model system is the reaction of a series of secondary alicyclic amines toward phenyl 2,4,6-trinitrophenyl ether in aqueous ethanol mixtures of different compositions. From solvent effect studies, it is found that only piperidine is sensitive to solvation effects, a result that may be traced to the polarity of the solvent composition in the ethanol/water mixture, which points to a specific electrophilic solvation in the aqueous phase.