Intracellular killing of Brucella melitensis in human macrophages with microspheres-encapsulated gentamicin

Objectives: Treatment of human brucellosis demands antibiotic targeting into the mononuclearphagocytic system. The aim of this work was to prepare and characterize particulate carriers containing gentamicin and to study their interactions with phagocytic cells and bactericidal activity against intracellular Brucella melitensis. Methods: Different poly(lactide-co-glycolide) (PLGA)polymers with free carboxylic end-group wereusedto formulate micro- and nanoparticles containing gentamicin, by a water-oil-water solvent-evaporation technique. PLGA 502H and 75:25H microparticles were selected because they showed the highest gentamicin loadings as well as good physico-chemical properties and sustained release in vitro. Results: Gentamicin-containing microspheres of both polymers were successfully phagocytosed by infected THP-1 human monocytes, and immunocytochemistry studies revealed that the antibiotic reached Brucella-specific compartments. A dose of 30 mg of encapsulated gentamicin was able to reduce intracellular Brucella infection by 2.2 log. Conclusions: Altogether, these results suggest that 502H and 75:25H microspheres are suitable carriers for gentamicin targeting inside human macrophages and thus for brucellosis treatment

A Radiation Imaging Detector Made by Postprocessing a Standard CMOS Chip

An unpackaged microchip is used as the sensing element in a miniaturized gaseous proportional chamber. Thisletter reports on the fabrication and performance of a complete radiation imaging detector based on this principle. Our fabrication schemes are based on wafer-scale and chip-scale postprocessing.\ud Compared to hybrid-assembled gaseous detectors, our microsystem shows superior alignment precision and energy resolution, and offers the capability to unambiguously reconstruct 3-D radiation tracks on the spot.\u

Comparación de las propiedades de materiales constitutivos de una superficie ecuestre profesional por medio del método de «Pista en Caja»

Bauhinia. forficata Link. subsp. pruinosa (Vogel) Fortunato & Wunderlin, crece naturalmente desde Paraguay, Sur de Brasil hasta Argentina, y tiene antecedente de uso ornamental y terapéutico (diurético, antidiarreico, hipoglucemiante). Este proyecto tiene como objetivo la caracterización de poblaciones de bauhinia forficata subsp pruinosa utilizando marcadores moleculares. Existen SSRs diseñados en taxones afines: Cercis canadensis L. y C. chinensis, de los que hay antecedentes de transferibilidad entre especies. Por ello se evaluó su transferencia en las poblaciones de Bauhinia. Estos resultados asociados a los que se obtengan de las evaluaciones químicas permitirán conocer su relación con los biotipos que se identifiquen.  Para esto, se extrajo ADN mediante el método de Dellaporta (1983)1 de 10 individuos del Jardín botánico Arturo E. Ragonese, se cuantificó y se realizó PCR de los SSRs seleccionados. El producto se sembró, junto con un marcador de peso molecular, en geles desnaturalizantes de poliacrilamida en cubas de secuenciación teñidos con nitrato de plata y revelados con hidróxido de sodio. Hasta el momento, se evaluaron 15 SSRs (6 provinieron de C. chinensis y 9 de C. canandensis). De estos 15 SSRs, 11 mostraron productos de amplificación. De ellos 9 fueron polimórficos indicando diferencias interpoblacionales, que podrían indicar variabilidad química y por lo tanto resta correlacionar la actividad biológica de los distintos biotipos. Además, algunos SSRs mostraron más de un locus, información que respalda lo señalado por Poggio et al.2 que en la subfamilia Cercidoideae, Bauhinia (2n=28) se generó por hibridación y poliploídia a partir del ancestro Cercis (2n= 14). Además, se realizó el muestreo de 20 puntos de colecta distribuidas en las provincias de Misiones, Córdoba y Buenos Aires de por lo menos tres individuos por punto. Estos individuos serán evaluados mediante técnicas de SSR para determinar mediante distintos parámetros la variabilidad intra e interpoblaciona

La ciencia andaluza a golpe de ratón

El Sistema de Información Científica de Andalucía (SICA) es una ventana al conocimiento que se produce en nuestra comunidad autónoma. En 2010 ha comenzado el diseño de SICA2 que situará a esta plataforma en la vanguardia de la sistematización y la difusión de la investigació

Quantitative determination of the antitumor alkyl ether phospholipid edelfosine by reversed-phase liquid chromatography-electrospray mass spectrometry: application to cell uptake studies and characterization of drug delivery systems.

Edelfosine is a synthetic alkyl ether phospholipid that represents a promising class of antitumor agents. However, analytical methods to measure these type compounds are scarce. The lack of a reliable methodology to quantify edelfosine is a major problem in ongoing and scheduled preclinical and clinical trials with this drug. We evaluated the applicability of high-performance liquid chromatography–mass spectrometry to determine edelfosine in biological samples and polymeric delivery systems. Sample pre-treatment involved polymer precipitation or cell lysis with methanol. HPLC separation was performed on an Alltima RPC18 narrow-bore column and edelfosine quantification was done by electrospray ionization mass spectrometry (ESI-MS) using positive ion mode and selected ion monitoring. Assays were linear in the tested range of 0.3–10 μg/ml. The limit of quantification was 0.3 ng/sample in both matrices, namely biological samples and polymeric delivery systems. The interassay precision ranging from 0.79 to 1.49%, with relative errors of −6.7 and 12.8%. Mean extraction recovery was 95.6%. HPLC–ESI-MS is a reliable system for edelfosine analysis and quantification in samples from different sources, combining advantages of full automation (rapidity, ease of use, no need of extensive extraction procedures) with high analytical performance and throughput

Physiological bases of bone regeneration I : Histology and physiology of bone tissue

Bone is the only body tissue capable of regeneration, allowing the restitutio ad integrum following trauma. In the event of a fracture or bone graft, new bone is formed, which following the remodeling process is identical to the pre-existing. Bone is a dynamic tissue in constant formation and resorption. This balanced phenomena, known as the remodeling process, allows the renovation of 5-15% of the total bone mass per year under normal conditions (1). Bone remodeling consists of the resorption of a certain amount of bone by osteoclasts, likewise the formation of osteoid matrix by osteoblasts, and its subsequent mineralization. This phenomenon occurs in small areas of the cortical bone or the trabecular surface, called ?Basic Multicellular Units? (BMU). Treatment in Traumatology, Orthopedics, Implantology, and Maxillofacial and Oral Surgery, is based on the biologic principals of bone regeneration, in which cells, extracellular matrix, and osteoinductive signals are involved. The aim of this paper is to provide an up date on current knowledge on the biochemical and physiological mechanisms of bone regeneration, paying particular attention to the role played by the cells and proteins of the bone matrix

Peritoneal tuberculosis due to Mycobacterium caprae

The incidence of tuberculosis in humans due to Mycobacterium caprae is very low and is almost confined to Europe. We report a case of a previously healthy 41-year-old Moroccan with a 6 month history of abdominal pain, weight loss, fatigue and diarrhea. A diagnosis of peritoneal tuberculosis due to M. caprae was mad

Physiological bases of bone regeneration II : The remodeling process

Bone remodeling is the restructuring process of existing bone, which is in constant resorption and formation. Under normal conditions, this balanced process allows the renewal of 5 ? 10% of bone volume per year. At the microscopic level, bone remodeling is produced in basic multicellular units, where osteoclasts resorb a certain quantity of bone and osteoblasts form the osteoid matrix and mineralize it to fill the previously created cavity. These units contain osteoclasts, macrophages, preosteoblasts and osteoblasts, and are controlled by a series of factors, both general and local, allowing normal bone function and maintaining the bone mass. When this process becomes unbalanced then bone pathology appears, either in excess (osteopetrosis) or deficit (osteoporosis). The purpose of this study is to undertake a revision of current knowledge on the physiological and biological mechanisms of the bone remodeling process; highlighting the role played by the regulating factors, in particular that of the growth factor