ZnO nucleation into trititanate nanotubes by ALD equipment techniques, a new way to functionalize layered metal oxides.

In this contribution, we explore the potential of atomic layer deposition (ALD) techniques for developing new semiconductor metal oxide composites. Specifically, we investigate the functionalization of multi-wall trititanate nanotubes, H2Ti3O7 NTs (sample T1) with zinc oxide employing two different ALD approaches: vapor phase metalation (VPM) using diethylzinc (Zn(C2H5)2, DEZ) as a unique ALD precursor, and multiple pulsed vapor phase infiltration (MPI) using DEZ and water as precursors. We obtained two different types of tubular H2Ti3O7 species containing ZnO in their structures. Multi-wall trititanate nanotubes with ZnO intercalated inside the tube wall sheets were the main products from the VPM infiltration (sample T2). On the other hand, MPI (sample T3) principally leads to single-wall nanotubes with a ZnO hierarchical bi-modal functionalization, thin film coating, and surface decorated with ZnO particles. The products were mainly characterized by electron microscopy, energy dispersive X-ray, powder X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. An initial evaluation of the optical characteristics of the products demonstrated that they behaved as semiconductors. The IR study revealed the role of water, endogenous and/or exogenous, in determining the structure and properties of the products. The results confirm that ALD is a versatile tool, promising for developing tailor-made semiconductor materials.

Neisseria gonorrhoeae Challenge Increases Matrix Metalloproteinase-8 Expression in Fallopian Tube Explants.

Background:Neisseria gonorrhoeae (Ngo) is the etiological agent of gonorrhea, a sexually transmitted infection that initially infects the female lower genital tract. In untreated women, the bacteria can ascend to the upper genital reproductive tract and infect the fallopian tube (FTs), which is associated with salpingitis and can lead to impaired FT function and infertility. The extracellular matrix (ECM) plays an important role in cell migration and differentiation in the female genital tract, and some pathogens modify the ECM to establish successful infections. The ECM is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), their endogenous inhibitors; MMP deregulation causes pathological conditions in a variety of tissues. Results: The aim of this work was to analyze the expression and localization of MMP-3, MMP-8, MMP-9, and TIMP-1 in FT explants during Ngo infection using real-time PCR, immunohistochemistry, zymography and ELISA. No significant variations in MMP-3, MMP-9, and TIMP-1 transcript levels were observed. In contrast, a significant increase (p < 0.05) was observed for MMP-8 expression and was accompanied by stromal immunoreactivity in infected explants. ELISA results supported these findings and showed that MMP-8 release increased upon gonococcal infection. Conclusions: Our results indicate that gonococcal infection induces increased MMP-8 expression, which might contribute to FT damage during infection.

Multifunctional polymeric nanoparticles doubly loaded with SPION and ceftiofur retain their physical and biological properties.

BACKGROUND: Advances in nanostructure materials are leading to novel strategies for drug delivery and targeting, contrast media for magnetic resonance imaging (MRI), agents for hyperthermia and nanocarriers. Superparamagnetic iron oxide nanoparticles (SPIONs) are useful for all of these applications, and in drug-release systems, SPIONs allow for the localization, direction and concentration of drugs, providing a broad range of therapeutic applications. In this work, we developed and characterized polymeric nanoparticles based on poly (3-hydroxybutyric acid-co-hydroxyvaleric acid) (PHBV) functionalized with SPIONs and/or the antibiotic ceftiofur. These nanoparticles can be used in multiple biomedical applications, and the hybrid SPION-ceftiofur nanoparticles (PHBV/SPION/CEF) can serve as a multifunctional platform for the diagnosis and treatment of cancer and its associated bacterial infections. RESULTS: Morphological examination using transmission electron microscopy (TEM) showed nanoparticles with a spherical shape and a core-shell structure. The particle size was evaluated using dynamic light scattering (DLS), which revealed a diameter of 243.0 ± 17 nm. The efficiency of encapsulation (45.5 ± 0.6% w/v) of these polymeric nanoparticles was high, and their components were evaluated using spectroscopy. UV-VIS, FTIR and DSC showed that all of the nanoparticles contained the desired components, and these compounds interacted to form a nanocomposite. Using the agar diffusion method and live/dead bacterial viability assays, we demonstrated that these nanoparticles have antimicrobial properties against Escherichia coli, and they retain their magnetic properties as measured using a vibrating sample magnetometer (VSM). Cytotoxicity was assessed in HepG2 cells using live/dead viability assays and MTS, and these assays showed low cytotoxicity with IC50 > 10 mg/mL nanoparticles. CONCLUSIONS: Our results indicate that hybrid and multifunctional PHBV/SPION/CEF nanoparticles are suitable as a superparamagnetic drug delivery system that can guide, concentrate and site-specifically release drugs with antibacterial activity.

Paclitaxel-PHBV nanoparticles and their toxicity to endometrial and primary ovarian cancer cells.

This report is an integrated study to include the molecular simulation, physicochemical characterization and biological analysis of a paclitaxel-loaded PHBV nanoparticle that demonstrates uptake, release and cytotoxicity in cancer cell lines. Taking this nanoparticle one step closer to its use in a clinical setting, we demonstrate that it causes significant cell death in primary cultures of stage IIIc serous ovarian cancer cells isolated from six patients. Molecular simulations revealed a high affinity of paclitaxel for the water-polymer interface, thus the drug is delivered only when the polymer near it is degraded. The Fourier transform infrared spectroscopy suggests the formation of a short-lived crystalline phase, also observed in the CG simulations, and transmission electron microscopy revealed branched structures on the surface of particles, which disappeared after 4 days. Biological analyses indicated that these particles have a 48-h window of toxicity protection, allowing for the endocytosis of the particle by the cells; this finding was corroborated by confocal microscopy and flow cytometry. The low cost to synthesize PHBV using microorganisms and the potential chemical modifications of the polymer make it attractive for inexpensive, large-scale pharmaceutical production.

Consequences of nongenomic actions of estradiol on pathogenic genital tract response.

Estradiol is a steroid hormone that regulates the structure and function of the female reproductive system. In addition to its genomic effects, which are mediated by activated nuclear receptors, estradiol elicits a variety of rapid signaling events independently of transcriptional or genomic regulation. These nongenomic actions influence the milieu of the genital tract, which changes the ability of pathogens to infect the genital tract. This review discusses our current knowledge regarding the mechanisms and relevance of nongenomic estradiol signaling in the genital tract that could change the ability of pathogens to invade epithelial cells. PubMed was searched through January 1980 for papers related to estradiol actions in the ovary, fallopian tube, uterus and cervix. The mechanisms conveying these rapid effects consist of a multitude of signaling molecules and include cross-talk with slower transcriptional actions. The nongenomic actions of estradiol that influence the infectious abilities of pathogens occur either directly on the genital tract cells or indirectly by modulating the local and systemic immune systems. Additional in-depth characterization of the response is required before the normal and pathological reproductive functions of the nongenomic estradiol pathway can be targeted for pharmacological intervention.

La heterogeneidad del alfabetismo en salud y el consentimiento informado en Chile / The case against template informed consent procedures in biomedical research: heterogeneity in health literacy in Chile

Se examinó el alfabetismo en salud en Chile con el fin de determinar si se pueden usar procedimientos de consentimiento informado estándares en esta población. Se evaluó el alfabetismo en salud con la versión abreviada de la prueba SAHLSA. Los resultados se expresaron como el porcentaje de respuestas correctas en cada prueba. El promedio global de respuestas correctas fue 85.4 ± 13.5 % (media aritmética ± desviación estándar, n=762). Hubo diferencias importantes entre los subgrupos examinados. El nivel más bajo de alfabetismo en salud se detectó en pescadores artesanales y sus familias y en estudiantes de liceos públicos, y el más alto en estudiantes universitarios y madres pobladoras atendidas en el sistema público de salud. Los resultados muestran la necesidad que los procedimientos de consentimiento informado tomen en cuenta la heterogeneidad del alfabetismo en salud de la población chilena.

Health literacy was examined in Chile to assess whether it is homogenous enough to allow the use of "templates" for informed consent, and to identity subgroups that may need special consideration when recruited for research because of their low health literacy abbreviated SAHLSA test of health literacy was used. Results were expressed as percent of correct answers out of the 50 items of the SAHLSA test. There was high health literacy with 85.4 ± 13.5 % (arithmetic mean ± standard deviation, «=762) of correct answers. There were important differences between groups, with lower scores in artisanal fishermen families and high-school students attending public schools, and higher scores in university students and mothers attending the public health system. Results show that a case by case approach is probably more appropriate when seeking informed consent in this population because of the variability of health literacy.

Differential expression of extracellular matrix components in the Fallopian tubes throughout the menstrual cycle.

BACKGROUND: One of the unique characteristics of the female genital tract is the extensive tissue remodeling observed throughout the menstrual cycle. Multiple components of the extracellular matrix take part in this tissue rebuilding; however, the individual components involved have not been identified. METHODS: In the present study, the expression of extracellular matrix proteins and selected matrix metalloproteinase (MMP) activities in Fallopian tubes (FT) throughout the menstrual cycle were examined by PCR array, immunocytochemistry, zymography and bioinformatics. RESULTS: Of the eighty-four genes analyzed, eighty-three were expressed in the FT during at least one stage of the menstrual cycle. We observed a significant increase (>/=2-fold) in ADAMTS1, ADAMTS13, COL7A1, MMP3, MMP9, PECAM1, and THBS3 in the periovulatory phase compared to the follicular phase. Meanwhile, we observed a significant decrease (>/= 2-fold) in COL7A1, ICAM1, ITGA8, MMP16, MMP9, CLEC3B, SELE and TIMP2 in the lutheal phase compared to the periovulatory phase. Immunocytochemistry showed that MMP-3 and MMP-9 were localized in the endosalpinx during all phases of the menstrual cycle. Gelatin zymograms detected non-cycle-dependent protease activity. CONCLUSIONS: Several extracellular matrix components were regulated throughout the menstrual cycle in a cyclic pattern, suggesting a possible steroid regulation and a role in tissue remodeling and FT functions.

Ceftiofur-loaded PHBV microparticles: a potential formulation for a long-acting antibiotic to treat animal infections

Background: The infectious diseases in the livestock breeding industry represent a significant drawback that generates substantial economic loss and have led to the indiscriminate use of antibiotics. The formulation of polymeric microparticles loaded with antibiotics for veterinary use can: reduce the number of required doses; protect the drug from inactivation; and maintain a sustained-release of the antibiotic drug at effective levels. Accomplishing all of these goals would have a significant economic and animal health impact on the livestock breeding industry. Results: In this work, we formulated ceftiofur-loaded PHBV microparticles (PHBV-CEF) with a spherical shape, a smooth surface and diameter sizes between 1.65 and 2.37 μm. The encapsulation efficiency was 39.5 +/- 1.1 percent w/w, and we obtained a sustained release of ceftiofur in PBS-buffer (pH 7.4) over 7 days. The antibacterial activity of ceftiofur was preserved after the encapsulation procedure, and toxicity of PHBV-CEF microparticles evaluated by MTS was represented by an IC50 > 10 mg/mL. Conclusions: Our results suggest that PHBV-CEF particles have a potential application for improving the treatment of infectious diseases in the livestock breeding industry.

Modelos matemáticos del condicionamiento clásico: evolución y desafíos actuales / Mathematical models of classical conditioning: evolution and current challenges

From the beginning of the study of classical conditioning, the formulation of mathematical theories has been a major goal of theoreticians. After more than a century of research, the amount of empirical data accumulated is impressive and the theories have become progressively more complex and sophisticated. Nowadays, there is such a diversity of models, each addressing only certain categories of phenomena and using somewhat different formalisms, that a critical analysis seems opportune. This article attempts to provide such an analysis for the Spanish speaking audience.

Desde los inicios del estudio del condicionamiento clásico, la formulación de modelos matemáticos ha sido uno de los principales objetivos de los autores. Después de más de un siglo de investigación, la cantidad de información empírica acumulada es impresionante y los modelos teóricos han llegado a ser progresivamente más complejos y sofisticados. Hoy en día es tal la diversidad de modelos, cada uno implementado con distintos formalismos y destinado a explicar diferentes grupos de fenómenos, que una evaluación crítica nos parece oportuna. Este artículo pretende entregar este análisis al público de habla hispana.