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The translation of silver-based nanotechnology 'from bench to bedside' requires a deep understanding of the molecular aspects of its biological action, which remains controversial at low concentrations and non-spherical morphologies. Here, we present a hemocompatibility approach based on the effect of the distinctive electronic charge distribution in silver nanoparticles (nanosilver) on blood components. According to spectroscopic, volumetric, microscopic, dynamic light scattering measurements, pro-coagulant activity tests, and cellular inspection, we determine that at extremely low nanosilver concentrations (0.125-2.5µg ml-1), there is a relevant interaction effect on the serum albumin and red blood cells (RBCs). This explanation has its origin in the surface charge distribution of nanosilver particles and their electron-mediated energy transfer mechanism. Prism-shaped nanoparticles, with anisotropic charge distributions, act at the surface level, generating a compaction of the native protein molecule. In contrast, the spherical nanosilver particle, by exhibiting isotropic surface charge, generates a polar environment comparable to the solvent. Both morphologies induce aggregation at NPs/bovine serum albumin ≈ 0.044 molar ratio values without altering the coagulation cascade tests; however, the spherical-shaped nanosilver exerts a negative impact on RBCs. Overall, our results suggest that the electron distributions of nanosilver particles, even at extremely low concentrations, are a critical factor influencing the molecular structure of blood proteins' and RBCs' membranes. Isotropic forms of nanosilver should be considered with caution, as they are not always the least harmful.

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Among external stimuli-responsive therapy approaches, those using near infrared (NIR) light irradiation have attracted significant attention to treat bone-related diseases and bone tissue regeneration. Therefore, the development of metallic biomaterials sensitive to NIR stimuli is an important area of research in orthopaedics. In this study, we have generated in situ prism-shaped silver nanoparticles (p-AgNPs) in a biomorphic nano-holed TiO2 coating on a Ti6Al4V alloy (a-Ti6Al4V). Insertion of p-AgNPs does not disturb the periodically arranged sub-wavelength-sized unit cell on the a-Ti6Al4V dielectric structure, while they exacerbate its peculiar optical response, which results in a higher NIR reflectivity and high efficiency of NIR photothermal energy conversion suitable to bacterial annihilation. Together, these results open a promising path toward strategic bone therapeutic procedures, providing novel insights into precision medicine.

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BACKGROUND: In addition to their key role in hemostasis, platelets and megakaryocytes regulate immune and inflammatory responses, in part through their expression of Toll-like receptors (TLRs). Among the TLRs, TLR3 recognizes dsRNA associated with viral infection. Thrombocytopenia is a frequent complication of viral infection. However, the expression and functionality of TLR3 in megakaryocytes and platelets is not yet well understood. OBJECTIVE: To study the expression and functionality of TLR3 in the megakaryocytic lineage. METHODS AND RESULTS: RT-PCR, flow cytometric and immunofluorescence assays showed that TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets. Immunoblotting assays showed that stimulation of megakaryocytes with two synthetic agonists of TLR3, Poly(I:C) and Poly(A:U), activated the nuclear factor-κB (NF-κB), phosphoinositide 3-kinase (PI3K)/Akt, extracellular signal-related kinase (ERK)1/2 and p38 pathways. TLR3-megakaryocyte activation resulted in reduced platelet production in vitro and interferon-ß release through the PI3K-Akt and NF-κB signaling pathways. TLR3 ligands potentiated the aggregation mediated by classic platelet agonists. This effect was also observed for ATP release, but not for P-selectin or CD40L membrane exposure, indicating that TLR3 activation was not involved in α-granule release. In addition, TLR3 agonists induced activation of the NF-κB, PI3K-Akt and ERK1/2 pathways in platelets. Reductions in platelet production and platelet fibrinogen binding mediated by Poly(I:C) or Poly(A:U) were prevented by the presence of an inhibitor of the TLR3-dsRNA complex. CONCLUSIONS: Our findings indicate that functional TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets, and suggest a potential role for this receptor in the megakaryopoiesis/thrombopoiesis alterations that occur in viral infections.

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In this study an automatic method for sample treatment and spectrophotometric determination of hydroxyproline in commercial sausages was developed. A flow-batch system that includes the steps of sample hydrolysis and determination of the analyte was designed. The method presents a linear range between 0.60 and 3.60 µg mL(-1) of hydroxyproline. A relative standard deviation of 1.68% was obtained from hydroxyproline standard solution (n=6, 1.20 µg mL(-1)) and the detection limit was 0.12 µg mL(-1). The sample throughput was 1 sample h(-1) while the reference method (AOAC) was carried out in about 17 h. This method employs 16 h of hydrolysis while in the proposed method the hydrolysis time was 15 min. For this purpose a pressure hydrolysis chamber with a low cost halogen lamp was used. The flow-batch system is simple and allows the use of both chambers (hydrolysis and detection) simultaneously. The obtained results with the flow-batch method are in good agreement with that obtained with the reference method. Moreover, it is good alternative to the quality control of meat products.

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Las infecciones nosocomiales por Staphylococcus spp constituyen uno de los problemas de mayor preocupación en salud pública en todo el mundo. Debido a que existen diferencias según centro hospitalario, paciente, área y tiempo de internación es esencial conocer el perfil de resistencia a los antibióticos más utilizados de las cepas de Staphylococcus involucradas en estas infecciones. El objetivo del presente estudio fue determinar el perfil de resistencia de los aislados de Staphylococcus aureus (Sau) y Estafilococo coagulasa negativo (ECN) de muestras de hemocultivos de pacientes adultos, pediátricos y recién nacidos internados entre el 1 de junio de 2005 al 30 de junio de 2006, en varios servicios del Hospital Central del Instituto de Previsión Social (IPS.).Se realizó un análisis retrospectivo de los resultados de antibiograma realizados en el Servicio de Microbiología del IPS. Los antibióticos evaluados fueron oxacilina (OXA), penicilina (PEN), eritromicina (ERY), clindamicina (CLI), ciprofloxacina (CIP), gentamicina (GEN), trimetoprim-sulfametoxazol (TMS), tetraciclina (TET) y vancomicina (VAN). De 5698 hemocultivos realizados en este periodo, 1706 (30%) fueron positivos. De estos, en 755 (44%) se aisló Staphylococcus spp; correspondiendo 327 (43,3%) a Sau y 428 (56,7%) a ECN. El perfil de resistencia para Sau y ECN fue respectivamente como sigue: OXA 64% y 87%, PEN 96% y 95%, ERY 48% y 52%, CIP 42% y 40%, GEN 48% y 48% y no presentaron R a VAN. El 58% de los Sau y el 56% de los ECN fueron resistentes a más de 4 antibióticos. La alta frecuencia de resistencia a la meticilina y la poliresistencia hallada en este trabajo deben ser tenidos en cuenta a la hora de indicar esquemas de antibióticos empíricos y para realizar ajustes oportunos de los ya iniciados. No se encontró ninguna cepa resistente a la vancomicina, que es considerada el mejor antimicrobiano disponible para el tratamiento de infecciones por estafilococos resistentes a las penicilinas que no son inhibidas por las penicilinasas.

Nosocomial infections due to Staphylococcus spp areone of the major concerns in public health all over the world. Because there are differences according to health center, patient, area and days of hospitalization, the knowledge of the resistance profile of Staphylococcus spp to the most common antibiotics is essential. The objective of the present study was to determine the resistance pattern of Staphylococcus aureus (Sau) and coagulase-negative staphylococci strains isolated from hemoculture of adult, pediatric and neonatal patients, hospitalized in the Hospital Central del Instituto de Previsión Social from June 1, 2005 to June 30, 2006. Antibiogram results carried out at the Laboratory of Microbiology of the IPS were retrospectively reviewed. The antibiotics evaluated were oxacillin (OXA), penicillin (PEN), erythromycin (ERY), clindamycin (CLI), ciprofloxacin (CIP), gentamicin (GEN), trimethoprim-sulphametoxazol (TMS), tetracycline (TET) and vancomycin (VAN). Of the 5,698 hemocultures carried out in this period, 1706 (30%) were positive. Staphylococcus spp was isolated in 755 (44%) samples; 327 (43.3%) of them corresponded to Sau and 428 (56.7%) to ECN. Resistance profile for Sau and ECN were as follows: OXA 64% and 87%, PEN 96% and 95%, ERY 48% and 52%, CIP 42% and 40%, GEN 48% and 48% and VAN did not present resistance to any of the antibiotics tested. Fifty eight percent of all Sau and 56% of ECN isolates were resistant to more than 4 antibiotics. The high frequency of penicillin resistance and poly resistance found in this study have to be taken into account at the time of choosing an empirical antibiotic scheme and for the adjustment of those already implemented. No isolates were resistant to vancomycin which is still the best antibiotic available for the treatment of infections due to penicillin resistant Staphylococcus that are inhibited by penicillinase.

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La biopsia renal es el principal método de diagnóstico de las glomerulopatías. El Registro de biopsias renales es importante para conocer la situación epidemiológica y clínico­patológica de las enfermedades renales de un país y las variaciones geográficas entre los países o continentes. Para conocer la situación actual de las glomerulopatías del Paraguay se ha realizado el presente estudio en 1.365 biopsias renales registradas entre agosto de 1989 a junio de 2005 en el Departamento de Patología del IICS, que es el Centro de Referencia y Registro de Biopsias Renales del país, analizando sus aspectos histológicos, demográficos y las diferencias entre periodos quinquenales de estudio. Del total de casos, 1072 (75.5%) fueron glomerulopatías y, a diferencia de la mayoría de los países, se observó un predominio de glomerulonefritis secundarias (GNS) (57.3%) de las cuales 85.9% fueron nefritis lúpica (NL). En las glomerulonefritis primarias (GNP) la GN proliferativa mesangial (GNPM) y la membranoproliferativa (GNMP) fueron las mas frecuentes (39.8% y 28.2%), mientras que la Nefropatía por IgA (NIgA) y la Enfermedad de cambios mínimos (ECM) fueron raras (1.9% y 1.3%). No se observaron cambios significativos de incremento o disminución de tipos histológicos a través de los periodos de estudio tanto en las GNP como en las GNS. La existencia de este registro de biopsias renales fue la base para la creación del Registro de Glomerulopatías del Paraguay en el año 2004, cuyos datos son necesarios para establecer programas de tratamiento y prevención de las enfermedades glomerulares en nuestro país a fin de disminuir su progresión al estadío terminal.

Renal biopsy is the main diagnostic method of glomerulopathies. The registry of renal biopsies is important to know the epidemiological and clinical and pathological situation of renal diseases of a country and the geographic variations between countries or continents. In order to know the current situation of glomerulopathies in our country, we studied 1,365 renal biopsies registered between August 1989 to June 2005 at the Pathology Department of the IICS, the reference center and the Renal Biopsy Registry of the country, analyzing histological and demographic aspects as well as the differences between five­year periods of study. On the total cases, 1,072 (75.5%) were glomerulopathies while secondary glomerulonephritis (SGN) were more frequent (57.3 %) with 85.9% of lupus nephritis (LN) in contrast to most countries. Among primary glomerulonephritis (PGN), mesangioproliferative GN (MPGN) and membranoproliferative GN (MPGN) were predominant (39.8% and 28.2%) while IgA Nephropathy (IgAN) and Minimal Change Disease (ECM) were rare (1.9% and 1.3%). We did not observe significant changes of increases or decreases of histological types through the study periods in PGN as well as in SGN. The existence of this registry of renal biopsy was the base for the creation of the Paraguayan Registry of Glomerulopathies in 2004, which data are necessary to establish treatment and prevention programs of glomerular diseases in our country in order to decrease their progression to end­stage renal disease.

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El desarrollo del trabajo se basa en el modelo conceptual y el conjunto de variables que propone Mosley para el estudio de la mortalidad en la niñez. Constituye un primer paso para el analisis mas profundo de los determinantes del comportamiento de esa variable demografica en la Republica Argentina. Se presenta una caracterizacion de la provincia de Misiones como marco de referencia para facilitar el analisis y la interpretacion de los resultados obtenidos

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El desarrollo del trabajo se basa en el modelo conceptual y el conjunto de variables que propone Mosley para el estudio de la mortalidad en la niñez. Constituye un primer paso para el analisis mas profundo de los determinantes del comportamiento de esa variable demografica en la Republica Argentina. Se presenta una caracterizacion de la provincia de Misiones como marco de referencia para facilitar el analisis y la interpretacion de los resultados obtenidos

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