3D Printing of Large Areas of Highly Ordered Submicron Patterns for Modulating Cell Behavior.

Fabricating large areas of geometrically complex and precisely controlled topographies is required for the studies of cell behavior on patterned surfaces. Direct laser writing (DLW) is an advanced 3D-fabrication technique, which facilitates the manufacturing of structures within various scales (from a few hundred nanometers to millimeters). However, this method requires improvements in the accuracy and reproducibility of the submicron and nanoscale features that are printed over a large area. Here, we present a scheme to both improve the uniformity of the printed submicron patterns and decrease the printing time. The effects of various processing parameters (e.g., laser power and writing field) on the dimensions and uniformity of submicron pillars as well as on their Young's modulus and surface wettability were assessed. Decreasing the writing field to 33 × 33 µm2 significantly improved the uniformity of submicron pillars that were printed over an area of 4 mm2 in a single-step process. Preosteoblast cells (MC3T3-E1) were used to assess the cytocompatibility of the used material (IP-L780 resin) with a focus on cell morphology, cell proliferation, cytoskeletal organization, and the elastic modulus of the cells. The cells cultured for 2 days on the submicron pillars showed a polarized shape and a higher Young's modulus of the area corresponding to the nucleus relative to those cultured on flat surfaces. Taken together, the results of the current study clearly show that the submicron patterns created using DLW are both cytocompatible and could modulate the morphology and mechanical properties of cells. This work paves the way for direct printing of submicron features with controlled Young's moduli over large areas in a single-step process, which is necessary for systematically studying how such patterns modulate cellular functions.

Granuloma piógeno tratamiento mediante la técnica de electroshave modificada experiencia de un servicio de dermatología pediátrica en tres años / Pyogenic granuloma treatment using modified electroshave technique a three years experience of a pediatric dermatology service

RESUMEN El granuloma piógeno (GP) o hemangioma capilar lobulillar, es un tumor vascular benigno adquirido. Suele presentarse como una lesión única y de un tamaño menor a 1 cm. Debido aque suele presentar hemorragia espontánea, debe realizarse su exéresis a la mayor brevedad posible. Existen múltiples tratamientos descritos, los que presentan la desventaja de destruir la totalidad del tumor, sin poder rescatar material para su estudioanátomo-patológico. Materiales y Métodos se realizó un estudio retrospectivo y descriptivo. Seevaluaron 41 pacientes con diagnóstico presuntivo de GP, tratados con la técnica de electroshave modificada, atendidos en el servicio desde Enero de 2014 hasta Enero de 2017. Resultados la técnica de electroshave modificada, permitió realizar la exéresis total de la lesión en el 100 % de los pacientes, con escaso sangrado, permitiendoen todos los casos la evaluación histopatológica, con una correlación del 98%.Además presenta una alta tasa de éxito terapéutico, con sólo 10% de recurrencias. Conclusión la técnica de electroshave modificada, tiene ventajas sobre el resto de las utilizadas respecto de: su rapidez y facilidad de ejecución, escaso sangrado, baja recurrencia, obtención de muestra para histopatología y la posibilidad de realizarse con anestesia local. Además puede ser utilizada en otras lesiones tumorales papilomatosas exofíticas.

SUMMARY Pyogenic granuloma (PG) is a vascular benign acquired tumor. Most frequently it is a single lesion with size less than 1 cm. Because it usually presents with hemorrhage the exeresis must be done as soon as possible. There are multiple treatments for the PG, but all have the disadvantage of destroying the entire tumor without being able to rescue material for histopathological study. Materials and Methods a retrospective and descriptive study was carried out. There were 41 patients evaluated with presumptive diagnosis of PG, treated with the modified electroshave technique, attended in our service from January 2014 to January 2017. Results the modified electroshave technique allowed us to perform the total exeresis of the lesion in 100% of the patients, with little bleeding. In all cases the histopathological evaluation was done, with a correlation of 98% with the initial clinical diagnosis. This technique also demonstrated a high rate of therapeutic success, with only 10% of recurrences. Conclusion the modified electroshave technique has advantages over the rest: its speed and ease of execution, little bleeding, low recurrence, obtaining sample for histopathology and the possibility of performing it with local anesthesia. It can also be used in other exophytic papillomatous tumor lesions.

Locally adapted traits maintained in the face of high gene flow.

Gene flow between phenotypically divergent populations can disrupt local adaptation or, alternatively, may stimulate adaptive evolution by increasing genetic variation. We capitalised on historical Trinidadian guppy transplant experiments to test the phenotypic effects of increased gene flow caused by replicated introductions of adaptively divergent guppies, which were translocated from high- to low-predation environments. We sampled two native populations prior to the onset of gene flow, six historic introduction sites, introduction sources and multiple downstream points in each basin. Extensive gene flow from introductions occurred in all streams, yet adaptive phenotypic divergence across a gradient in predation level was maintained. Descendants of guppies from a high-predation source site showed high phenotypic similarity with native low-predation guppies in as few as ~12 generations after gene flow, likely through a combination of adaptive evolution and phenotypic plasticity. Our results demonstrate that locally adapted phenotypes can be maintained despite extensive gene flow from divergent populations.

Thickness measurement of soft thin films on periodically patterned magnetic substrates by phase difference magnetic force microscopy.

The need for accurate measurement of the thickness of soft thin films is continuously encouraging the development of techniques suitable for this purpose. We propose a method through which the thickness of the film is deduced from the quantitative measurement of the contrast in the phase images of the sample surface acquired by magnetic force microscopy, provided that the film is deposited on a periodically patterned magnetic substrate. The technique is demonstrated by means of magnetic substrates obtained from standard floppy disks. Colonies of Staphylococcus aureus adherent to such substrates were used to obtain soft layers with limited lateral (a few microns) and vertical (hundreds of nanometers) size. The technique is described and its specific merits, limitations and potentialities in terms of accuracy and measurable thickness range are discussed. These parameters depend on the characteristics of the sensing tip/cantilever as well as of the substrates, the latter in terms of spatial period and homogeneity of the magnetic domains. In particular, with the substrates used in this work we evaluated an uncertainty of about 10%, a limit of detection of 50-100 nm and an upper detection limit (maximum measurable thickness) of 1 µm, all obtained with standard lift height values (50-100 nm). Nonetheless, these parameters can be easily optimized by selecting/realizing substrates with suitable spacing and homogeneity of the magnetic domains. For example, the upper detection limit can be increased up to 25-50 µm while the limit of detection can be reduced to a few tens of nanometers or a few nanometers.

Fear, food and sexual ornamentation: plasticity of colour development in Trinidadian guppies.

The evolution of male ornamentation often reflects compromises between sexual and natural selection, but it may also be influenced by phenotypic plasticity. We investigated the developmental plasticity of male colour ornamentation in Trinidadian guppies in response to two environmental variables that covary in nature: predation risk and food availability. We found that exposure to chemical predator cues delayed the development of pigment-based colour elements, which are conspicuous to visual-oriented predators. Predator cues also reduced the size of colour elements at the time of maturity and caused adult males to be less colourful. To the best of our knowledge, these findings provide the first example of a plastic reduction in the development of a sexually selected male ornament in response to predator cues. The influence of predator cues on ornamentation probably affects individual fitness by reducing conspicuousness to predators, but could reduce attractiveness to females. Reduced food availability during development caused males to delay the development of colour elements and mature later, probably reflecting a physiological constraint, but their coloration at maturity and later in adulthood was largely unaffected, suggesting that variation in food quantity without variation in quality does not contribute to condition dependence of the trait.

Effects of selective serotonin reuptake inhibitor therapy on endothelial function and inflammatory markers in patients with coronary heart disease.

We investigated the effect of sertraline on inflammation and endothelial function in patients with coronary heart disease (CHD) and symptoms of depression. One hundred patients with CHD and depression were randomized in a double-blind fashion to receive sertraline or a placebo. We measured symptoms of depression (Beck Depression Inventory (BDI) score), levels of inflammatory markers (C-reactive protein (CRP) and interleukin-6 (IL-6)), and flow-dependent endothelium-mediated dilation (FMD) before and after 20 weeks of treatment. Sertraline treatment significantly reduced the BDI score as compared with both baseline and placebo. Levels of CRP and IL-6 also decreased after 20 weeks of sertraline treatment, whereas they did not significantly change in the placebo group. There was a significant improvement in FMD in patients on sertraline treatment, whereas there was no change in FMD in the placebo group. Sertraline improves endothelial function and reduces inflammatory markers in patients with CHD and symptoms of depression.

Octreotide in the outpatient therapy of cirrhotic chylous ascites: a case report.

Chylous ascites is a rare complication of liver cirrhosis associated with a poor short-term prognosis. We report the case of an 80-year-old male cirrhotic patient with refractory chylous ascites associated with portal hypertension. He was treated with total parenteral nutrition but chylous ascites relapsed at suspension. Patient was put on long-term subcutaneous octreotide (100 microg t.i.d.) as an outpatient. The treatment was well tolerated and led to clinical improvement, markedly reducing the need of total paracentesis and the amount of ascites. Octreotide was stopped after 6 months, and massive ascites did not relapse. After 1 year the patient was alive, with no need of paracentesis. Octreotide therapy should be considered in patients with cirrhosis and chylous ascites to simplify the outpatient management of the disease.

Ectoparasites of the island fox on Santa Cruz Island.

The ectoparasite fauna for island foxes (Urocyon littoralis) on Santa Cruz Island (California, USA) in April (wet season) and September (dry season) 1998 was evaluated. Three taxa of ectoparasites were identified. These were fleas (Pulex irritans), lice (Neotrichodectes mephitidis), and ticks (Ixodes pacificus). Ectoparasite abundances varied seasonally. Typical of insular endemic species, island foxes may be especially vulnerable to the introduction of novel disease organisms and their vectors.

Raman excitation profiles of actinomycin D.

Pre-resonance Raman spectra of actinomycin D have been measured using the exciting lines of an Ar+ laser. The analysis of the excitation profiles provided information on the origin of the electronic states; in particular, the absorption feature between 400 and 500 nm was interpreted as due to a vibrational structure of a single electronic state which is located at 450 nm. In addition, on the basis of the excitation profiles, the number of observed Raman bands, and their frequencies, it has been possible to propose a vibrational assignment of the chromophoric framework of the drug.