Classification of Depression Through Resting-State Electroencephalogram as a Novel Practice in Psychiatry: Review.

BACKGROUND: Machine learning applications in health care have increased considerably in the recent past, and this review focuses on an important application in psychiatry related to the detection of depression. Since the advent of computational psychiatry, research based on functional magnetic resonance imaging has yielded remarkable results, but these tools tend to be too expensive for everyday clinical use. OBJECTIVE: This review focuses on an affordable data-driven approach based on electroencephalographic recordings. Web-based applications via public or private cloud-based platforms would be a logical next step. We aim to compare several different approaches to the detection of depression from electroencephalographic recordings using various features and machine learning models. METHODS: To detect depression, we reviewed published detection studies based on resting-state electroencephalogram with final machine learning, and to predict therapy outcomes, we reviewed a set of interventional studies using some form of stimulation in their methodology. RESULTS: We reviewed 14 detection studies and 12 interventional studies published between 2008 and 2019. As direct comparison was not possible due to the large diversity of theoretical approaches and methods used, we compared them based on the steps in analysis and accuracies yielded. In addition, we compared possible drawbacks in terms of sample size, feature extraction, feature selection, classification, internal and external validation, and possible unwarranted optimism and reproducibility. In addition, we suggested desirable practices to avoid misinterpretation of results and optimism. CONCLUSIONS: This review shows the need for larger data sets and more systematic procedures to improve the use of the solution for clinical diagnostics. Therefore, regulation of the pipeline and standard requirements for methodology used should become mandatory to increase the reliability and accuracy of the complete methodology for it to be translated to modern psychiatry.

Characterization and study of the antibacterial mechanisms of silver nanoparticles prepared with microalgal exopolysaccharides.

The green synthesis of biomaterials is of significant interest as it enables the safe and sustainable preparation of noble metallic nanoparticles for medical applications. Microalgae polysaccharides have received attention due to their outstanding properties such as biocompatibility, biodegradability and low cost. In addition, due to their variety of remarkable biological and physicochemical properties, polysaccharide-based nanoparticles have advantageous features yet to be explored. The primary objective of the current research was to investigate exopolysaccharides isolated from green microalgae Botryococcus braunii (EPBb) and Chlorella pyrenoidosa (EPCp), as both reducing and stabilizing agents, for the green synthesis of silver nanoparticles (AgNPs). Their antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus) was studied, as well as their cytotoxicity to human dermal fibroblasts. The presently synthesized AgNPs were spherical in shape and exhibited characteristic surface plasmon resonance at 430 nm. The main population had a particle size which ranged between 5 and 15 nm as analyzed by transmission electron micrographs. Zeta potentials averaged -51.81 ±â€¯3.01 mV using EPBb and -12.16 ±â€¯2.41 mV using EPCp. More importantly, AgNPs possessed strong antibacterial activity in a dose-dependent manner, even against drug-resistant bacteria. The enhanced antibacterial activity of these particles is explained due to extensive reactive oxygen species generation and bacterial cell membrane damage. In contrast, such AgNPs were not cytotoxic at the same therapeutic range to fibroblasts (0.5-10.0 µg/mL). In summary, these results showed that polysaccharide-capped AgNPs have a strong potential for numerous medical applications, such as antibacterial agents in pharmaceutical and biomedical areas.

Designing Nanostructured Ti6Al4V Bioactive Interfaces with Directed Irradiation Synthesis toward Cell Stimulation to Promote Host-Tissue-Implant Integration.

A new generation of biomaterials are evolving from being biologically inert toward bioactive surfaces, which can further interact with biological components at the nanoscale. Here, we present directed irradiation synthesis (DIS) as a novel technology to selectively apply plasma ions to bombard any type of biomaterial and tailor the nanofeatures needed for in vitro growth stimulation. In this work, we demonstrate for the first time, the influence of physiochemical cues (e.g., self-organized topography at nanoscale) of medical grade Ti6Al4V results in control of cell shape, adhesion, and proliferation of human aortic smooth muscle stem cells. The control of surface nanostructures was found to be correlated to ion-beam incidence angle linked to a surface diffusive regime during irradiation synthesis with argon ions at energies below 1 keV and a fluence of 2.5 × 1017 cm-2. Cell viability and cytoskeleton morphology were evaluated at 24 h, observing an advance cell attachment state on post-DIS surfaces. These modified surfaces showed 84% of cell biocompatibility and an increase in cytoplasmatic protusions ensuring a higher cell adhesion state. Filopodia density was promoted by a 3-fold change for oblique incidence angle DIS treatment compared to controls (e.g., no patterning) and lamellipodia structures were increased more than a factor of 2, which are indicators of cell attachment stimulation due to DIS modification. In addition, the morphology of the nanofeatures were tailored, with high fidelity control of the main DIS parameters that control diffusive and erosive regimes of self-organization. We have correlated the morphology and the influence in cell behavior, where nanoripple formation is the most active morphology for cell stimulation.

Balancing biofunctional and biomechanical properties using porous titanium reinforced by carbon nanotubes.

Despite the well-known advantages of the titanium-based implant systems, they still lack an optimal balance between biofunctionality and mechanical strength, especially regarding the modulation of cellular response and a desired implant osseointegration. In this work, we fabricated a nanocomposite based on porous commercially pure grade 4 titanium (c.p. Ti) reinforced with carbon nanotubes (CNT) at 5% and 10% w/w, with the aim of obtaining a nanocomposite with lower stiffness compared to traditional titanium-based implants and with the mechanical strength and bioactivity owed by the CNT. Results obtained by scanning electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy characterization showed that the CNT dispersed and incorporated into the porous c.p. Ti matrix. Interestingly, CNT were associated with a higher twining within neighbor Ti grains, which was indeed consistent with an increased in nano-hardness. Biological evaluation by MTT and Comet assay revealed that the nanocomposites did not induce genotoxicity and cytotoxicity on two different cells lines despite the presence of nickel at the surface. Accordingly, a purification step would be required before these CNT can be used for biomedical applications. Our results indicate that incorporation of CNT into porous c.p. Ti is a promising avenue to achieve an adequate balance between biofunctionality and mechanical strength in Ti-based scaffolds for tissue replacement. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 719-731, 2019.

In situ Study Unravels Bio-Nanomechanical Behavior in a Magnetic Bacterial Nano-cellulose (MBNC) Hydrogel for Neuro-Endovascular Reconstruction.

Surgical clipping and endovascular coiling are well recognized as conventional treatments of Penetrating Brain Injury aneurysms. These clinical approaches show partial success, but often result in thrombus formation and the rupture of aneurysm near arterial walls. The authors address these challenging brain traumas with a unique combination of a highly biocompatible biopolymer hydrogel rendered magnetic in a flexible and resilient membrane coating integrated to a scaffold stent platform at the aneurysm neck orifice, which enhances the revascularization modality. This work focuses on the in situ diagnosis of nano-mechanical behavior of bacterial nanocellulose (BNC) membranes in an aqueous environment used as tissue reconstruction substrates for cerebral aneurysmal neck defects. Nano-mechanical evaluation, performed using instrumented nano-indentation, shows with very low normal loads between 0.01 to 0.5 mN, in the presence of deionized water. Mechanical testing and characterization reveals that the nano-scale response of BNC behaves similar to blood vessel walls with a very low Young´s modulus, E (0.0025 to 0.04 GPa), and an evident creep effect (26.01 ± 3.85 nm s-1 ). These results confirm a novel multi-functional membrane using BNC and rendered magnetic with local adhesion of iron-oxide magnetic nanoparticles.

Bacterial Nanocellulose Magnetically Functionalized for Neuro-Endovascular Treatment.

Current treatments for brain aneurysms are invasive, traumatic, and not suitable in most patients with increased risks. A new alternative method is using scaffold stents to create a local and focal attraction force of cells for an in situ reconstruction of the tunica media. For this purpose, a nanostructured bioactive coating is designed to render an asymmetric region of the stent scaffold magnetic and biomimetic, which utilizes bacterial nanocellulose (BNC) as a platform for both magnetic and cell attraction as well as proliferation. The magnetization of the BNC is realized through the reaction of Fe III and II, precipitating superparamagnetic iron oxide nanoparticles (SPION). Subsequently, magnetic bacterial nanocellulose (MBNC) is coated with polyethylene glycol to improve its biocompatibility. Cytotoxicity and biocompatibility are evaluated using porcine aortic smooth muscle cells. Preliminary cellular migration assays demonstrate the behavior between MBNC and cells labeled with SPION. In this work, (1) synthesis of BNC impregnated with magnetic nanoparticles is successfully demonstrated; (2) a viable, resilient, and biocompatible hydrogel membrane is tested for neuroendovascular application using a stent scaffold; (3) cell viability and minimal cytotoxicity is achieved; (4) cell migration tests and examination of cellular magnetic attraction confirm the viability of MBNC as a multifunctional coating.

Red selenium nanoparticles and gray selenium nanorods as antibacterial coatings for PEEK medical devices.

Bacterial infections are commonly found on various poly(ether ether ketone) (PEEK) medical devices (such as orthopedic instruments, spinal fusion devices, and segments in dialysis equipment), and thus, there is a significant need for introducing antibacterial properties to such materials. The objective of this in vitro study was to introduce antibacterial properties to PEEK medical devices by coating them with nanosized selenium. In this study, red selenium (an elemental form of selenium) nanoparticles were coated on PEEK medical devices through a quick precipitation method. Furthermore, with heat treatment at 100°C for 6 days, red selenium nanoparticles were transferred into gray selenium nanorods on the PEEK surfaces. Bacteria test results showed that both red and gray selenium-coated PEEK medical devices significantly inhibited the growth of Pseudomonas aeruginosa compared with uncoated PEEK after either 1, 2, or 3 days. Red selenium nanoparticle-coated PEEK showed less bacteria growth on its surface than gray selenium nanorod-coated PEEK after 3 days. This study demonstrated that red, and to a lesser extent gray, nanosized selenium could be used as potential antibacterial coatings to prevent bacteria function on PEEK medical devices. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1352-1358, 2016.

Shape and surface chemistry effects on the cytotoxicity and cellular uptake of metallic nanorods and nanospheres.

Metallic nanoparticles (such as gold and silver) have been intensely studied for wound healing applications due to their ability to be easily functionalized, possess antibacterial properties, and their strong potential for targeted drug release. In this study, rod-shaped silver nanorods (AgNRs) and gold nanorods (AuNRs) were fabricated by electron beam physical vapor deposition (EBPVD), and their cytotoxicity toward human skin fibroblasts were assessed and compared to sphere-shaped silver nanospheres (AgNSs) and gold nanospheres (AuNSs). Results showed that the 39.94 nm AgNSs showed the greatest toxicity with fibroblast cells followed by the 61.06 nm AuNSs, ∼556 nm × 47 nm (11.8:1 aspect ratio) AgNRs, and the ∼534 nm × 65 nm (8.2:1 aspect ratio) AuNRs demonstrated the least amount of toxicity. The calculated IC50 (50% inhibitory concentration) value for the AgNRs exposed to fibroblasts was greater after 4 days of exposure (387.3 µg mL(-1)) compared to the AgNSs and AuNSs (4.3 and 23.4 µg mL(-1), respectively), indicating that these spherical metallic nanoparticles displayed a greater toxicity to fibroblast cells. The IC50 value could not be measured for the AuNRs due to an incomplete dose response curve. The reduced cell toxicity with the presently developed rod-shaped nanoparticles suggests that they may be promising materials for use in numerous biomedical applications.

Shape and surface effects on the cytotoxicity of nanoparticles: Gold nanospheres versus gold nanostars.

Gold nanoparticles are materials with unique optical properties that have made them very attractive for numerous biomedical applications. With the increasing discovery of techniques to synthesize novel nanoparticles such as star-shaped gold nanoparticles for biomedical applications, the safety and performance of these new nanomaterials must be systematically assessed before use. In this study, gold nanostars (AuNSTs) with multibranched surface structures were synthesized, and their influence on the cytotoxicity of human skin fibroblasts and rat fat pad endothelial cells (RFPECs) were assessed and compared with that of gold nanospheres (AuNSPs) with unbranched surfaces. Results showed that the AuNSPs with diameters of approximately 61.46 nm showed greater toxicity with fibroblast cells and RFPECs compared with the synthesized AuNSTs with diameters of approximately 33.69 nm. The AuNSPs were lethal at concentrations of 40 µg/mL for both cell lines, whereas the AuNSTs were less toxic at higher concentrations (400 µg/mL). The calculated IC50 (50% inhibitory concentration) values of the AuNSPs exposed to fibroblast cells were greater at 1 and 4 days of culture (26.4 and 27.7 µg/mL, respectively) compared with the RFPECs (13.6 and 13.8 µg/mL, respectively), indicating that the AuNSPs have a greater toxicity to endothelial cells. It was proposed that possible factors that could be promoting the reduced toxicity effects of the AuNSTs to fibroblast cells and RFPECs, compared with the AuNSPs may be size, surface chemistry, and shape of the gold nanoparticles. The reduced cell toxicity observed with the AuNSTs suggests that AuNSTs may be a promising material for use in biomedical applications.

Osseointegration improvement by plasma electrolytic oxidation of modified titanium alloys surfaces.

Titanium (Ti) is a material frequently used in orthopedic applications, due to its good mechanical properties and high corrosion resistance. However, formation of a non-adherent fibrous tissue between material and bone drastically could affect the osseointegration process and, therefore, the mechanical stability of the implant. Modifications of topography and configuration of the tissue/material interface is one of the mechanisms to improve that process by manipulating parameters such as morphology and roughness. There are different techniques that can be used to modify the titanium surface; plasma electrolytic oxidation (PEO) is one of those alternatives, which consists of obtaining porous anodic coatings by controlling parameters such as voltage, current, anodizing solution and time of the reaction. From all of the above factors, and based on previous studies that demonstrated that bone cells sense substrates features to grow new tissue, in this work commercially pure Ti (c.p Ti) and Ti6Al4V alloy samples were modified at their surface by PEO in different anodizing solutions composed of H2SO4 and H3PO4 mixtures. Treated surfaces were characterized and used as platforms to grow osteoblasts; subsequently, cell behavior parameters like adhesion, proliferation and differentiation were also studied. Although the results showed no significant differences in proliferation, differentiation and cell biological activity, overall results showed an important influence of topography of the modified surfaces compared with polished untreated surfaces. Finally, this study offers an alternative protocol to modify surfaces of Ti and their alloys in a controlled and reproducible way in which biocompatibility of the material is not compromised and osseointegration would be improved.

Insights into the prevalence of software project defects.

This paper analyses the effect of the effort distribution along the software development lifecycle on the prevalence of software defects. This analysis is based on data that was collected by the International Software Benchmarking Standards Group (ISBSG) on the development of 4,106 software projects. Data mining techniques have been applied to gain a better understanding of the behaviour of the project activities and to identify a link between the effort distribution and the prevalence of software defects. This analysis has been complemented with the use of a hierarchical clustering algorithm with a dissimilarity based on the likelihood ratio statistic, for exploratory purposes. As a result, different behaviours have been identified for this collection of software development projects, allowing for the definition of risk control strategies to diminish the number and impact of the software defects. It is expected that the use of similar estimations might greatly improve the awareness of project managers on the risks at hand.

Development of porous titanium for biomedical applications: A comparison between loose sintering and space-holder techniques.

One of the most important concerns in long-term prostheses is bone resorption as a result of the stress shielding due to stiffness mismatch between bone and implant. The aim of this study was to obtain porous titanium with stiffness values similar to that exhibited by cortical bone. Porous samples of commercial pure titanium grade-4 were obtained by following both loose-sintering processing and space-holder technique with NaCl between 40 and 70% in volume fraction. Both mechanical properties and porosity morphology were assessed. Young's modulus was measured using uniaxial compression testing, as well as ultrasound methodology. Complete characterization and mechanical testing results allowed us to determine some important findings: (i) optimal parameters for both processing routes; (ii) better mechanical response was obtained by using space-holder technique; (iii) pore geometry of loose sintering samples becomes more regular with increasing sintering temperature; in the case of the space-holder technique that trend was observed for decreasing volume fraction; (iv) most reliable Young's modulus measurements were achieved by ultrasound technique.

Analysis of a simulated microarray dataset: comparison of methods for data normalisation and detection of differential expression (open access publication).

Microarrays allow researchers to measure the expression of thousands of genes in a single experiment. Before statistical comparisons can be made, the data must be assessed for quality and normalisation procedures must be applied, of which many have been proposed. Methods of comparing the normalised data are also abundant, and no clear consensus has yet been reached. The purpose of this paper was to compare those methods used by the EADGENE network on a very noisy simulated data set. With the a priori knowledge of which genes are differentially expressed, it is possible to compare the success of each approach quantitatively. Use of an intensity-dependent normalisation procedure was common, as was correction for multiple testing. Most variety in performance resulted from differing approaches to data quality and the use of different statistical tests. Very few of the methods used any kind of background correction. A number of approaches achieved a success rate of 95% or above, with relatively small numbers of false positives and negatives. Applying stringent spot selection criteria and elimination of data did not improve the false positive rate and greatly increased the false negative rate. However, most approaches performed well, and it is encouraging that widely available techniques can achieve such good results on a very noisy data set.

Endoftalmitis candidiásica: presentación de dos casos / Candida endophthalmitis: report of two cases

Se denomina endoftalmitis a un proceso inflamatorio que afecta a la cavidad ocular y a las estructuras adyacentes. En su etiología intervienen agentes infecciosos (hongos, virus, bacterias, protozoos y parásitos), neoplasias, sangre intraocular y material retenido de lentes, luego de la cirugía de cataratas. Se presentan dos casos de endoftalmitis candidiásica que afectaron a dos pacientes jóvenes inmunocompetentes. En los dos casos se realizó tratamiento con anfotericina B y 5 fluorcitosina. A uno de ellos se le realizó una vitrectomía bilateral, quedando con una secuela visual permanente. Sólo el diagnóstico precoz y el tratamiento oportuno y efectivo reducen las posibilidades de lesiones retinianas permanentes en estos pacientes

Endoftalmitis candidiásica: presentación de dos casos / Candida endophthalmitis: report of two cases

Se denomina endoftalmitis a un proceso inflamatorio que afecta a la cavidad ocular y a las estructuras adyacentes. En su etiología intervienen agentes infecciosos (hongos, virus, bacterias, protozoos y parásitos), neoplasias, sangre intraocular y material retenido de lentes, luego de la cirugía de cataratas. Se presentan dos casos de endoftalmitis candidiásica que afectaron a dos pacientes jóvenes inmunocompetentes. En los dos casos se realizó tratamiento con anfotericina B y 5 fluorcitosina. A uno de ellos se le realizó una vitrectomía bilateral, quedando con una secuela visual permanente. Sólo el diagnóstico precoz y el tratamiento oportuno y efectivo reducen las posibilidades de lesiones retinianas permanentes en estos pacientes

Sepsis post-esplenectomía y púrpura fulminans por streptococcus pneumoniae / Sepsis post-splenectomy and purpura fulminans by Streptococcus pneumoniae

Tanto la esplenia anatómica como la funcional, predisponen a los cuadros de sepsis fulminante, ocasionados fundamentalmente por bacterias capsuladas. El término sepsis post-esplenectomía (SPE), se refiere a la aparición de bacteriemia asociada o no a meningitis o a neumonía fulminante, a partir de los 2 meses de realizada la esplenectomía. En un 50 por ciento de los casos de SPE, el agente etiológico es de Streptococcus pneumoniae. La púrpura fulminans es una variedad de vasculitis necrotizante, que produce extensas lesiones necróticas de miembros, y aparece en el curso de una sepsis grave. Se presenta una paciente de sexo femenino, de 53 años de edad, con antecedentes de esplenectomía hace 10 años por púrpura trombocitopénica idiopática, que ingresa a terapia intensiva por presentar hipotensión arterial y púrpura de miembros inferiores. En los hemocultivos y en el cultivo del LCR se observó desarrollo de S. pneumoniae. las lesiones dérmicas evolucionaron a púrpura fulminans. La paciente falleció al tercer mes de internación. Se concluye que, dada la alta incidencia de SPE con aislamiento del S. pneumoniae, el tratamiento empírico inicial debería estar dirigido, principalmente, contra este agente etiológico (AU)

Sepsis post-esplenectomía y púrpura fulminans por streptococcus pneumoniae / Sepsis post-splenectomy and purpura fulminans by Streptococcus pneumoniae

Tanto la esplenia anatómica como la funcional, predisponen a los cuadros de sepsis fulminante, ocasionados fundamentalmente por bacterias capsuladas. El término sepsis post-esplenectomía (SPE), se refiere a la aparición de bacteriemia asociada o no a meningitis o a neumonía fulminante, a partir de los 2 meses de realizada la esplenectomía. En un 50 por ciento de los casos de SPE, el agente etiológico es de Streptococcus pneumoniae. La púrpura fulminans es una variedad de vasculitis necrotizante, que produce extensas lesiones necróticas de miembros, y aparece en el curso de una sepsis grave. Se presenta una paciente de sexo femenino, de 53 años de edad, con antecedentes de esplenectomía hace 10 años por púrpura trombocitopénica idiopática, que ingresa a terapia intensiva por presentar hipotensión arterial y púrpura de miembros inferiores. En los hemocultivos y en el cultivo del LCR se observó desarrollo de S. pneumoniae. las lesiones dérmicas evolucionaron a púrpura fulminans. La paciente falleció al tercer mes de internación. Se concluye que, dada la alta incidencia de SPE con aislamiento del S. pneumoniae, el tratamiento empírico inicial debería estar dirigido, principalmente, contra este agente etiológico

Endocarditis de válvula nativa en un paciente con prótesis valvular y hemocultivos negativos / Valve endocarditis in a patient with valve prosthesis and negative blood culture

La endocarditis infecciosa (EI) es una infección microbiana que compromete el endocardio valvular o parietal, o el nacimiento de los grandes vasos arteriales. Se observa con una frecuencia de 50 o 60 casos por millón de personas y representa 1 de cada 1000 ingresos hospitalarios. El diagnóstico de EI se realiza sobre la base de criterios clínicos, bacteriológicos y ecocardiográficos. Actualmente, la EI con hemocultivos negativos representa menos del 10 por ciento del total de los casos. Se presenta un paciente de sexo masculino, de 70 años de edad, con antecedentes de valvuloplastía aórtica, que ingresa al hospital por manifestar síndrome febril prolongado y petequias en miembros inferiores. Se realizaron 8 series de hemocultivos que fueron negativos, 4 ecocardiogramas transtorácicos que fueron normales y un quinto ecocardiograma transesofágico, que permitió el diagnóstico de EI mitral. Se inició tratamiento con ampicilina/netilmicina, con óptima respuesta terapéutica. Se concluye afirmando la importancia de rrealizar ecocardiogramas transesofágicos, en pacientes con fuerte sospecha de EI, en especial en aquellos que cursan con hemocultivos negativos (AU)

Síndrome hemofagocítico asociado a neumonía de la comunidad / Hemophagocytic syndrome associated to communityns pneumonia

El síndrome hemofagocítico (SH) es una afección del sistema mononuclear fagocítico, caracterizado por una proliferación reactiva de histiocitos maduros no neoplásicos, con capacidad hemofagocítica. Suele ser reactivo a diversos trastornos, entre los que figuran las infecciones virales, bacterianas y micóticas, neoplasias y fármacos. Desde el punto de vista clínico, se presenta en forma brusca con fiebre, hepatoesplenomegalia, poliadenopatías, y pancitopenia periférica, pudiendo ser fatal. Se presenta un paciente de 42 años de edad, de sexo femenino, que ingresa al hospital por presentar un cuadro de insuficiencia respiratoria aguda, tos productiva con expectoración purulenta y shock, falleciendo en terapia intensiva a las 4 horas de su ingreso. En la necropsia se observó una neumonía a focos múltiples, con diplococos Gram +, realizándose diagnóstico de SH. Motiva su presentación la escasa frecuencia de casos descriptos de esta patología (AU)