Continuous Formation and Separation of Calcium-Alginate Capsules Containing Viable Mammalian Cells in Microfluidic Devices

Microfluidic devices can be used for many applications, including the formation of well-controlled emulsions. In this study, the capability to continuously create monodisperse droplets in a microfluidic device was used to form calcium-alginate capsules.Calcium-alginate capsules have many potential uses, such as immunoisolation of cells and microencapsulation of active drug ingredients or bitter agents in food or beverage products. The gelation of calcium-alginate capsules is achieved by crosslinking sodiumalginate with calcium ions. Calcium ions dissociated from calcium carbonate due to diffusion of acetic acid from a sunflower oil phase into an aqueous droplet containing sodium-alginate and calcium carbonate. After gelation, the capsules were separated from the continuous oil phase into an aqueous solution for use in biological applications. Typically, capsules are separated bycentrifugation, which can damage both the capsules and the encapsulated material. A passive method achieves separation without exposing the encapsulated material or the capsules to large mechanical forces, thereby preventing damage. To achieve passiveseparation, the use of a microfluidic device with opposing channel wa hydrophobicity was used to stabilize co-laminar flow of im of hydrophobicity is accomplished by defining one length of the channel with a hydrogel. The chosen hydrogel was poly (ethylene glycol) diacrylate, which adheres to the glass surface through the use of self-assembled monolayer of 3-(trichlorosilyl)-propyl methacrylate. Due to the difference in surface energy within the channel, the aqueous stream is stabilized near a hydrogel and the oil stream is stabilized near the thiolene based optical adhesive defining the opposing length of the channel. Passive separation with co-laminar flow has shown success in continuously separating calcium-alginatecapsules from an oil phase into an aqueous phase. In addition to successful formation and separation of calcium alginate capsules,encapsulation of Latex micro-beads and viable mammalian cells has been achieved. The viability of encapsulated mammalian cells was determined using a live/dead stain. The co-laminar flow device has also been demonstrated as a means of separating liquid-liquidemulsions.

Viable neutrophils release mitochondrial DNA to form neutrophil extracellular traps

Neutrophil extracellular traps (NETs) represent extracellular structures able to bind and kill microorganisms. It is believed that they are generated by neutrophils undergoing cell death, allowing these dying or dead cells to kill microbes. We show that, following priming with granulocyte/macrophage colony-stimulating factor (GM-CSF) and subsequent short-term toll-like receptor 4 (TLR4) or complement factor 5a (C5a) receptor stimulation, viable neutrophils are able to generate NETs. Strikingly, NETs formed by living cells contain mitochondrial, but no nuclear, DNA. Pharmacological or genetic approaches to block reactive oxygen species (ROS) production suggested that NET formation is ROS dependent. Moreover, neutrophil populations stimulated with GM-CSF and C5a showed increased survival compared with resting neutrophils, which did not generate NETs. In conclusion, mitochondrial DNA release by neutrophils and NET formation do not require neutrophil death and do also not limit the lifespan of these cells.

Les experiences de retour des sans-papiers rentrés en Equateur: Ressources et defies, mesures proposes pour un retour viable

Notre compréhension de la migration du retour est encore très limitée. Ce sujet n’a que peu retenu l’attention des spécialistes de la migration et il existe peu d’études qui donnent une vision différenciée sur les divers types de « retourné-e-s », leurs motivations à retourner dans leurs pays, les défis qu’ils/elles affrontent et les ressources dont ils/elles disposent pour parvenir à se réinsérer dans les pays d’origine. Il existe en particulier un manque important d’études qui examinent en détail la situation spécifique du retour des migrant-e-s sans-papiers et l’impact de l’aide de programmes gouvernementaux pour leur réinsertion socio-économique. Cette lacune est particulièrement marquée dans le cas de la Suisse. Confronté à la situation d’absence d’évaluations des programmes d’appui au retour des sans-papiers, et dans le but d’y apporter des améliorations possibles à son propre programme, le Service de la Population du canton de Vaud a chargé Yvonne Riaño de mener une recherche sur la situation de retour des sans-papiers retournés en Équateur entre 2008-2010 avec l’appui du programme. La recherche présentée ici se base sur un travail de terrain réalisé en Équateur en 2010. Nous avons rencontré 25 familles (70% du total des familles rentrées avec l’aide du Canton de Vaud) habitant dans diverses régions du pays et avons recueilli leurs expériences de retour. La méthodologie choisie pour la récolte des données est qualitative et combine entretiens narratifs et semi-directifs. La recherche examine les raisons d'émigration et du retour des personnes interviewées ainsi que la situation actuelle de leurs projets de réinsertion, leurs ressources disponibles et le défis auxquels elles font face pour la réalisation de leurs projets. Six principes clés sont proposés pour repenser l’aide au retour de façon à pouvoir garantir un retour viable.

Is thermochemotherapy with the Synergo system a viable treatment option in patients with recurrent non-muscle-invasive bladder cancer?

OBJECTIVES To prospectively evaluate the outcome of combined microwave-induced bladder wall hyperthermia and intravesical mitomycin C instillation (thermochemotherapy) in patients with recurrent non-muscle-invasive bladder cancer. METHODS Between 2003 and 2009, 21 patients (median age 70 years, range 35-95 years) with recurrent non-muscle-invasive bladder cancer (pTaG1-2 n = 9; pTaG3 n = 3; pT1 n = 9; concurrent pTis n = 8) were prospectively enrolled. Of 21 patients, 15 (71%) had received previous intravesical instillations with bacillus Calmette-Guérin, mitomycin C and/or farmorubicin. Thermochemotherapy using the Synergo system was carried out in 11 of 21 patients (52%) with curative intent, and in 10 of 21 patients (48%) as prophylaxis against recurrence. RESULTS The median number of thermochemotherapy cycles per patient was six (range 1-12). Adverse effects were frequent and severe: urinary urgency/frequency in 11 of 21 patients (52%), pain in eight of 21 patients (38%) and gross hematuria in five of 21 patients (24%). In eight of 21 patients (38%), thermochemotherapy had to be abandoned because of the severity of the adverse effects (pain in 3/8, severe bladder spasms in 2/8, allergic reaction in 2/8, urethral perforation in 1/8). Overall, six of 21 patients (29%) remained free of tumor after a median follow up of 50 months (range 1-120), six of 21 patients (29%) had to undergo cystectomy because of multifocal recurrences or cancer progression and seven of 21 patients (33%) died (2/7 of metastatic disease, 5/7 of non-cancer related causes). CONCLUSIONS Given the high rate of severe side-effects leading to treatment discontinuation, as well as the limited tumor response, thermochemotherapy should be offered only in highly selected cases of recurrent non-muscle-invasive bladder cancer.

What Makes Small-City Downtowns Viable?

The paper examines the experience of Connecticut's urban centers over the past century with an eye toward informing public policy. An in-depth qualitative discussion describes the rise and characteristics of urbanism, and then its unraveling. Linear regression analysis then quantifies the impact of various contributory factors on urban economic health in Connecticut cities since 1980. The findings suggest that local policymakers are largely unable to influence economic conditions in their cities.

Identifying and removing barriers to cycling as a viable means of transportation in Houston, Texas

The citizens of Houston, Texas, spend much time commuting. It has repeatedly been named among the “Fattest Cities” by Men’s Fitness Magazine (The fittest and fattest cities in America – Men’s Fitness. ). Obesity is one of its major public health problems as Houstonians often do not engage in enough physical activity to help them maintain their ideal weights. The use of bicycles provides a healthy and ecological alternative to commuting by driving. However, because urban cyclists must often share the roads with motorized vehicles, cyclists are often exposed to high levels of emissions. As vulnerable users of the roadways, urban cyclists also face the threat of injury. Nevertheless, there are some programs that encourage the use of bicycles. Laws and ordinances not only reveal public policy relating to bicycling but are a means to develop policy which can encourage bicycling. ^

A simple mathematical model that describes the growth of the area and the number of total and viable cells in yeast colonies

We propose a model, based on the Gompertz equation, to describe the growth of yeasts colonies on agar medium. This model presents several advantages: (i) one equation describes the colony growth, which previously needed two separate ones (linear increase of radius and of the squared radius); (ii) a similar equation can be applied to total and viable cells, colony area or colony radius, because the number of total cells in mature colonies is proportional to their area; and (iii) its parameters estimate the cell yield, the cell concentration that triggers growth limitation and the effect of this limitation on the specific growth rate. To elaborate the model, area, total and viable cells of 600 colonies of Saccharomyces cerevisiae, Debaryomyces fabryi, Zygosaccharomyces rouxii and Rhodotorula glutinis have been measured. With low inocula, viable cells showed an initial short exponential phase when colonies were not visible. This phase was shortened with higher inocula. In visible or mature colonies, cell growth displayed Gompertz-type kinetics. It was concluded that the cells growth in colonies is similar to liquid cultures only during the first hours, the rest of the time they grow, with near-zero specific growth rates, at least for 3 weeks.

Amino Acid Sequence Requirements of the Transmembrane and Cytoplasmic Domains of Influenza Virus Hemagglutinin for Viable Membrane Fusion

The amino acid sequence requirements of the transmembrane (TM) domain and cytoplasmic tail (CT) of the hemagglutinin (HA) of influenza virus in membrane fusion have been investigated. Fusion properties of wild-type HA were compared with those of chimeras consisting of the ectodomain of HA and the TM domain and/or CT of polyimmunoglobulin receptor, a nonviral integral membrane protein. The presence of a CT was not required for fusion. But when a TM domain and CT were present, fusion activity was greater when they were derived from the same protein than derived from different proteins. In fact, the chimera with a TM domain of HA and truncated CT of polyimmunoglobulin receptor did not support full fusion, indicating that the two regions are not functionally independent. Despite the fact that there is wide latitude in the sequence of the TM domain that supports fusion, a point mutation of a semiconserved residue within the TM domain of HA inhibited fusion. The ability of a foreign TM domain to support fusion contradicts the hypothesis that a pore is composed solely of fusion proteins and supports the theory that the TM domain creates fusion pores after a stage of hemifusion has been achieved.

RXR gamma null mice are apparently normal and compound RXR alpha +/-/RXR beta -/-/RXR gamma -/- mutant mice are viable.

The RXR gamma (RXR, retinoid X receptor) gene was disrupted in the mouse. Homozygous mutant mice developed normally and were indistinguishable from their RXR gamma +/- or wild-type littermates with respect to growth, fertility, viability, and apparent behavior in the animal facility. Moreover, RXR alpha -/-/RXR gamma -/- and RXR beta -/-/RXR gamma -/- mutant phenotypes were indistinguishable from those of RXR alpha -/- and RXR beta -/- mutants, respectively. Strikingly, RXR alpha +/-/RXR beta -/-/RXR gamma -/- triple mutants were viable. Thus, it appears that RXR gamma does not exert any essential function that cannot be performed by RXR alpha or RXR beta, and one copy of RXR alpha is sufficient to perform most of the functions of the RXRs.

Apolipoprotein B RNA editing enzyme-deficient mice are viable despite alterations in lipoprotein metabolism.

RNA editing in the nucleus of higher eukaryotes results in subtle changes to the RNA sequence, with the ability to effect dramatic changes in biological function. The first example to be described and among the best characterized, is the cytidine-to-uridine editing of apolipoprotein B (apo-B) RNA. The editing of apo-B RNA is mediated by a novel cytidine deaminase, apobec-1, which has acquired the ability to bind RNA. The stop translation codon generated by the editing of apo-B RNA truncates the full-length apo-B100 to form apo-B48. The recent observations of tumor formation in Apobec-1 transgenic animals, together with the fact that Apobec-1 is expressed in numerous tissues lacking apo-B, raises the issue of whether this enzyme is essential for a variety of posttranscriptional editing events. To directly test this, mice were created with a null mutation in Apobec-1 using homologous recombination in embryonic stem cells. Mice, homozygous for this mutation, were viable and made apo-B100 but not apo-B48. The null animals were fertile, and a variety of histological, behavioral, and morphological analyses revealed no phenotype other than abnormalities in lipoprotein metabolism, which included an increased low density lipoprotein fraction and a reduction in high density lipoprotein cholesterol. These studies demonstrate that neither apobec-1 nor apo-B48 is essential for viability and suggest that the major role of apobec-1 may be confined to the modulation of lipid transport.

Agouti regulation of intracellular calcium: role in the insulin resistance of viable yellow mice.

Several dominant mutations at the agouti locus in the mouse cause a syndrome of marked obesity, hyperinsulinemia, and insulin resistance. Although it is known that the agouti gene is expressed in an ectopic manner in these mutants, the precise mechanism by which the agouti gene product mediates these effects is unclear. Since intracellular Ca2+ is believed to play a role in mediating insulin action and dysregulation of Ca2+ flux is observed in diabetic animals and humans, we examined the status of intracellular Ca2+ in mice carrying the dominant agouti allele, viable yellow (Avy). We show here that in mice carrying this mutation, the intracellular free calcium concentration ([Ca2+]i) is elevated in skeletal muscle, and the degree of elevation is closely correlated with the degree to which the mutant traits are expressed in individual animals. Moreover, we demonstrate that the agouti gene product is capable of inducing increased [Ca2+]i in cultured and freshly isolated skeletal muscle myocytes from wild-type mice. Based on these findings, we present a model in which we propose that the agouti polypeptide promotes insulin resistance in mutant animals through its ability to increase [Ca2+]i.

¿Es viable un fondo de cohesión social iberoamericano?

Al margen de razones puramente solidarias, la cohesión social y las políticas orientadas a alcanzarla se justifican por los réditos recíprocos derivados de las relaciones económicas internacionales. Bajo determinadas circunstancias, estos réditos pueden aumentar gracias a las políticas de cohesión, tanto para los receptores como para los donantes netos de fondos. En primer lugar, porque se aprovechan en mayor medida las ventajas que proporciona la especialización productiva. En segundo lugar, porque aumentan los incentivos para reducir las barreras al movimiento de mercancías y factores de producción. En tercer lugar, porque pueden fortalecer las capacidades institucionales de los distintos países. Finalmente, porque, junto a estas razones de índole económico, existen también importantes beneficios de corte sociopolítico.

Una revisión de los condicionantes de la profesión periodística desde la perspectiva sociológica de McNair. ¿Es viable un periodismo profesional de calidad?

La actividad periodística se ha visto sometida en los últimos años a una transformación radical fundamentada, principalmente, aunque no sólo, en la revolución tecnológica que ha incrementado exponencialmente las posibilidades de unos medios además siguen lidiando con los condicionamientos procedentes de los entornos políticos, económicos, profesionales y sociales. Ante este nuevo escenario, se plantea una pregunta inmediata: ¿sigue resultando viable un periodismo profesional y de calidad con los condicionantes actuales? Este artículo trata de dar respuesta a la pregunta de investigación desde una revisión actualizada de la perspectiva sociológica sobre la que McNair analiza los factores que condicionan la profesión.