'Gel-Stacks' gently confine or reversibly immobilize arrays of single DNA molecules for manipulation and study.

Large DNA molecules (>20 kb) are difficult analytes prone to breakage during serial manipulations and cannot be 'rescued' as full-length amplicons. Accordingly, to present, modify and analyze arrays of large, single DNA molecules, we created an easily realizable approach offering gentle confinement conditions or immobilization via spermidine condensation for controlled delivery of reagents that support live imaging by epifluorescence microscopy termed 'Gel-Stacks.' Molecules are locally confined between two hydrogel surfaces without covalent tethering to support time-lapse imaging and multistep workflows that accommodate large DNA molecules. With a thin polyacrylamide gel layer covalently bound to a glass surface as the base and swappable, reagent-infused, agarose slabs on top, DNA molecules are stably presented for imaging during reagent delivery by passive diffusion.

Gel-Stacks technology provides multiple non-covalent molecular presentation modes, coupled with an unusually facile reagent delivery system designed for large-scale analytes, enhancing live imaging and manipulation. Enhanced further by modeling and software, Gel-Stacks technology becomes adaptable to a broad range of experimental applications.

A database of restriction maps to expand the utility of bacterial artificial chromosomes.

While Bacterial Artificial Chromosomes libraries were once a key resource for the genomic community, they have been obviated, for sequencing purposes, by long-read technologies. Such libraries may now serve as a valuable resource for manipulating and assembling large genomic constructs. To enhance accessibility and comparison, we have developed a BAC restriction map database. Using information from the National Center for Biotechnology Information's cloneDB FTP site, we constructed a database containing the restriction maps for both uniquely placed and insert-sequenced BACs from 11 libraries covering the recognition sequences of the available restriction enzymes. Along with the database, we generated a set of Python functions to reconstruct the database and more easily access the information within. This data is valuable for researchers simply using BACs, as well as those working with larger sections of the genome in terms of synthetic genes, large-scale editing, and mapping.

Discrete and Continuum Models for the Salt in Crowded Environments of Suspended Charged Particles.

Electrostatic forces greatly affect the overall dynamics and diffusional activities of suspended charged particles in crowded environments. Accordingly, the concentration of counter- or co-ions in a fluid-''the salt"-determines the range, strength, and order of electrostatic interactions between particles. This environment fosters engineering routes for controlling directed assembly of particles at both the micro- and nanoscale. Here, we analyzed two computational modeling schemes that considered salt within suspensions of charged particles, or polyelectrolytes: discrete and continuum. Electrostatic interactions were included through a Green's function formalism, where the confined fundamental solution for Poisson's equation is resolved by the general geometry Ewald-like method. For the discrete model, the salt was considered as regularized point-charges with a specific valence and size, while concentration fields were defined for each ionic species for the continuum model. These considerations were evolved using Brownian dynamics of the suspended charged particles and the discrete salt ions, while a convection-diffusion transport equation, including the Nernst-Planck diffusion mechanism, accounted for the dynamics of the concentration fields. The salt/particle models were considered as suspensions under slit-confinement conditions for creating crowded "macro-ions", where density distributions and radial distribution functions were used to compare and differentiate computational models. Importantly, our analysis shows that disparate length scales or increased system size presented by the salt and suspended particles are best dealt with using concentration fields to model the ions. These findings were then validated by novel simulations of a semipermeable polyelectrolyte membrane, at the mesoscale, from which ionic channels emerged and enable ion conduction.

Prevalencia de parásitos intestinales en perros de dos centros de bienestar animal de Medellín y el oriente antioqueño (Colombia), 2014 / Prevalence of Intestinal Parasites in Dogs from Two Centers of Animal Welfare from Medellín and eastern Antioquia (Colombia), 2014 / Prevalência de parasitas intestinais em cachorros de dois centros de bem-estar animal de Medellín e do oriente da região de Antioquia (na Colômbia), 2014

En Colombia poco se han estudiado las parasitosis intestinales en caninos, y los perros de la calle constituyen un grupo de elevado riesgo para la adquisición de enfermedades zoonóticas parasitarias. Por medio de un estudio descriptivo transversal realizado en 2014 se determinó la prevalencia de parasitosis intestinal en 68 caninos de ambos sexos de dos centros de bienestar animal de Medellín y el oriente antioqueño (Colombia) y sus factores asociados. El diagnóstico parasitológico se realizó por examen directo con solución salina al 0,8 % y lugol, y el método de flotación de Sheather. La prevalencia global de enteroparásitos fue 72,1 % (49), helmintos 58,8 % (40), protozoos 33,8 % (23) y poliparasitismo en el 45,6 % (31). Se identificaron 11 agentes parasitarios, de los cuales los más prevalentes fueron Uncinaria stenocephalia, con el 39,7 % (27); Ancylostoma caninum, con el 20,6 % (14); Trichuris vulpis, con el 16,2 % (11), y Toxocara spp., con el 11,8 % (8). Estos fueron estadísticamente mayores en el oriente antioqueño (valor p chi² < 0,05). Taenia spp. presentó una prevalencia de 4,4 % (3) y fue mayor en Medellín. No hubo asociación entre la prevalencia de cada taxón con el sexo ni la edad (valor p > 0,05). Se evidenció una alta prevalencia de parasitismo intestinal en caninos de Medellín y del oriente antioqueño, y gran diversidad en las prevalencias de los subgrupos estudiados. Esta información pone de manifiesto la necesidad de fomentar investigaciones tendientes a conocer la magnitud y los factores asociados en poblaciones específicas como base para la orientación de acciones en salud veterinaria y la salud pública, dado el potencial zoonótico de algunas parasitosis de caninos.

In Colombia, there are very few studies about intestinal parasitosis in dogs, and street dogs constitute a high-risk group for the acquisition of parasitic zoonotic diseases. Through a cross-sectional descriptive study carried out in 2014, the prevalence of intestinal parasitosis and its associated factors were determined in 68 dogs of both sexes from two animal welfare centers in Medellin and eastern Antioquia (Colombia). The parasitological diagnosis was made by direct examination with saline solution at 0.8% and iodine, and the Sheather flotation method. The overall prevalence of intestinal parasitosis was 72.1% (49), helminths 58.8% (40), protozoa 33.8% (23) and parasitism in 45.6% (31). 11 parasitic agents, of which the most prevalent were Uncinaria stenocephala with 39.7% (27), were identified; Ancylostoma caninum, with 20.6% (14); Trichuris vulpis, with 16.2% (11) and Toxocara spp., with 11.8% (8). These were statistically higher in eastern Antioquia (p value chi² < 0,05). Taenia spp. presented a prevalence of 4.4% (3) and it was higher in Medellin. There was no association between the prevalence of each taxon to sex or age (p value > 0.05). A high prevalence of intestinal parasitism in dogs from Medellin and eastern Antioquia was evidenced, as well as a great diversity in the prevalence of the subgroups studied. This information highlights the need to promote research in order to determine the magnitude and associated factors in specific populations as the foundation for targeting actions on veterinary health and public health, given the zoonotic potential of some parasitosis of dogs.

Na Colômbia são poucos os estudos realizados sobre as parasitoses intestinais em caninos, e os cachorros da rua constituem um grupo de elevado risco para a aquisição de doenças zoonótico parasitárias. Através de um estudo descritivo transversal realizado em 2014 se determinou a prevalência de parasitose intestinal em 68 caninos de ambos os sexos de dois centros de bem-estar animal de Medellín e do oriente da região de Antioquia (na Colômbia) e seus fatores associados. O diagnóstico parasitológico se realizou por exame direto com solução salina ao 0,8 % e lugol, e o método de flotação de Sheather. A prevalência global de enteroparasitas foi 72,1 % (49), helmintos 58,8 % (40), protozoários 33,8 % (23) e poli parasitismo em 45,6 % (31). Identificaram-se 11 agentes parasitários, dos quais os mais prevalentes foram Uncinaria stenocephala, com o 39,7 % (27); Ancylostoma caninum, com o 20,6 % (14); Trichuris vulpis, com 16,2 % (11), e Toxocara spp., com 11,8 % (8). Estes foram estatisticamente maiores no oriente da região de Antioquia (valor p chi² < 0,05). Taenia spp. Apresentou uma prevalência de 4,4 % (3) e foi maior em Medellín. Não houve associação entre a prevalência de cada táxon com o sexo nem a idade (valor p > 0,05). Evidenciou-se uma alta prevalência de parasitismo intestinal em caninos de Medellín e no oriente da região de Antioquia, e grande diversidade nas prevalências dos subgrupos estudados. Esta informação manifesta a necessidade de fomentar as pesquisas tendentes a conhecer a magnitude e os fatores associados em populações específicas como base para a orientação de ações em saúde veterinária e em saúde pública, devido o potencial zoonótico de algumas parasitoses de caninos.

Resonancia magnética en neuralgia del trigémino: presentación de tres casos / MRI in trigeminal neuralgia: presentation of three cases

La neuralgia del trigémino se caracteriza por episodios de dolor facial lancinante. Puede ser causada por diversas patologías que afectan cualquiera de los segmentos del V par. La resonancia magnética es de elección cuando se requieren estudios de imagen. Se presentan tres casos evaluados por este método y comprobados por cirugía.

Manifestacion de Aspergilosis Pulmonar Angioinvasiva como Sindrome de Vena Cava Superior / Angioinvasive aspergilosis as superior cava vein syndrome

En este artículo se presenta el caso de un paciente de diez años de edad con diagnóstico previo de anemia de Fanconi y antecedente de trasplante de médula ósea, manejado con inmunosupresores, quien manifiesta un cuadro clínico respiratorio rápidamente progresivo, acompañado de síndrome de vena cava superior secundario a infección por Aspergillus, variedad angioinvasiva. No se conocen casos similares reportados en el medio colombiano ni en la bibliografía médica actual.Aquí se refieren los hallazgos por imagen, el resultado histológico y la revisión bibliográfica

Esclerosis Múltiple seudotumoral, diagnostico por imágenes de resonancia mágnetica / Tumefactive multiple sclerosis

Presentamos dos casos interesantes de esclerosis múltiple, comprobados, con manifestaciones atípicas clínicas y por imagen, similares a neoplasias intracraneanas. Esta forma de presentación de la enfermedad es conocida como esclerosis múltiple seudotumoral. El conocimiento de sus hallazgos por imágenes de resonancia magnética, así como por exámenes clínicos y de laboratorio puede evitar procedimientos invasivos. Se hace una revisión actualizada del tema, en la que se recalca en el diagnóstico diferencial