Cell-assembled extracellular matrix (CAM): a human biopaper for the biofabrication of pre-vascularized tissues able to connect to the host circulationin vivo.

When considering regenerative approaches, the efficient creation of a functional vasculature, that can support the metabolic needs of bioengineered tissues, is essential for their survival after implantation. However, it is widely recognized that the post-implantation microenvironment of the engineered tissues is often hypoxic due to insufficient vascularization, resulting in ischemia injury and necrosis. This is one of the main limitations of current tissue engineering applications aiming at replacing significant tissue volumes. Here, we have explored the use of a new biomaterial, the cell-assembled extracellular matrix (CAM), as a biopaper to biofabricate a vascular system. CAM sheets are a unique, fully biological and fully human material that has already shown stable long-term implantation in humans. We demonstrated, for the first time, the use of this unprocessed human ECM as a microperforated biopaper. Using microvalve dispensing bioprinting, concentrated human endothelial cells (30 millions ml-1) were deposited in a controlled geometry in CAM sheets and cocultured with HSFs. Following multilayer assembly, thick ECM-based constructs fused and supported the survival and maturation of capillary-like structures for up to 26 d of culture. Following 3 weeks of subcutaneous implantation in a mice model, constructs showed limited degradative response and the pre-formed vasculature successfully connected with the host circulatory system to establish active perfusion.This mechanically resilient tissue equivalent has great potential for the creation of more complex implantable tissues, where rapid anastomosis is sine qua non for cell survival and efficient tissue integration.

p62/SQSTM1 upregulation constitutes a survival mechanism that occurs during granulocytic differentiation of acute myeloid leukemia cells.

The p62/SQSTM1 adapter protein has an important role in the regulation of several key signaling pathways and helps transport ubiquitinated proteins to the autophagosomes and proteasome for degradation. Here, we investigate the regulation and roles of p62/SQSTM1 during acute myeloid leukemia (AML) cell maturation into granulocytes. Levels of p62/SQSTM1 mRNA and protein were both significantly increased during all-trans retinoic acid (ATRA)-induced differentiation of AML cells through a mechanism that depends on NF-κB activation. We show that this response constitutes a survival mechanism that prolongs the life span of mature AML cells and mitigates the effects of accumulation of aggregated proteins that occurs during granulocytic differentiation. Interestingly, ATRA-induced p62/SQSTM1 upregulation was impaired in maturation-resistant AML cells but was reactivated when differentiation was restored in these cells. Primary blast cells of AML patients and CD34(+) progenitors exhibited significantly lower p62/SQSTM1 mRNA levels than did mature granulocytes from healthy donors. Our results demonstrate that p62/SQSTM1 expression is upregulated in mature compared with immature myeloid cells and reveal a pro-survival function of the NF-κB/SQSTM1 signaling axis during granulocytic differentiation of AML cells. These findings may help our understanding of neutrophil/granulocyte development and will guide the development of novel therapeutic strategies for refractory and relapsed AML patients with previous exposure to ATRA.

Enflurano, adrenalina e disritmias cardiacas. / Enflurane, adrenaline and cardiac arrhytmias

Enflurano foi utilizado para anestesiar 239 pacientes de ambos os sexos, todos do grupo I ou II da ASA, com idade media de 46 +/- 6 anos (media de DP) submetidos a cirurgias plasticas esteticas. Receberam inflitracao subcutanea ou submucosa de solucao de adrenalina para controle de sangramento do campo operatorio.As concentracoes de adrenalina foram de 1:200.000 em 0,4% de lidocaina para as ritidoplastias (volume medio e DP = 119 +/- 26 ml) e de 1:80.000 em 0,5% de lidocaina para as rinoplastias (volume medio e DP=16 +/- 5ml).Treze pacientes apresentaram disritmias cardiacas do tipo bigeminismo, durante ou logo apos a infiltracao de adrenalina. Simultaneamente, houve uma elevacao da pressao arterial. O ritmo sinusal foi restabelecido quando se aumentou a concentracao do enflurano para controlar a pressao arterial. O tempo maximo para o desaparecimento da disritmia foi de 4 minutos. O enflurano mostrou-se bastante seguro na associacao com a adrenalina para controle de sangramento do campo operatorio. Acreditamos que as disritmias ocorridas nesta fase nao merecem preocupacao, mas observacao, pois devem desaparecer logo. Caso nao desaparecam, resta a facilidade de trata-las com lidocaina por via venosa, como e classicamente recomendado

Enflurano e adrenalina: incidencia de disritmias cardiacas. / Enflurane and adrenaline; incidence of cardiac dysrhythmias

Ja foi estabelecido que os anestesicos halogenados sensibilizam o miocardio a adrenalina. No entanto e pratica entre os cirurgioes plasticos o uso de solucoes de adrenalina por injecao subcutanea ou submucosa para reduzir o sangramento no campo operatorio. Em 219 anestesias realizadas com enflurano para cirurgia plastica na fase, com concomitante infiltracao de adrenalina, em doses totais que chegaram a 1900 ug, encontramos apenas 16 pacientes que apresentaram extrassistolia ventricular. Esta disritmia cardiaca ocorreu durante ou logo apos a infiltracao da solucao, cujas concentracoes variaram de 1:200.000 a 1:800.000. Apenas 9 destes apresentam disritmia persistente que exigiu tratamento. Todos receberam lidocaina por via venosa em doses de 50 mg, tendo se recuperado por volta de 300 mg. Apenas um recebeu um tratamento adicional de cloreto de potassio por infusao com a solucao Ringer-lactato. Todos os pacientes foram monitorizados durante a anestesia e o eletrocardiograma registrado. Desde que os pacientes sejam bem observados e nao apresentem contra indicacao para o uso de adrenalina, achamos que e mais seguro esta associacao com a anestesia pelo enflurano que com qualquer outro anestesico halogenado de conhecimento no momento

[Bypass whartonostomy (author's transl)]. / Whartonostomie de dérivation. Indications, technique, résultats.

Submaxillary salivary retention, associated with the typical sign of a painful swelling, is usually but not specifically due to the presence of stones. Other factors may indeed be involved (reflex secretory dysfunction, stenosis from a scar, inflammation or tumor of wharton's duct). The authors describe a technique, employed in 14 patients, which involves a permanent bypass of "salivary flow" by the creation of a new excretory orifice in wharton's duct proximal to the obstacle producing salivary stasis. This technique is used as a complement to treatment of the cause of salivary retention, and appears to improve long-term results especially in some types of disorders due to submaxillary stones.

[Sialography of the submaxillary glands. A technique for catheterization of Wharton's duct (author's transl)]. / Sialographie des glandes sous maxillaires. A propos d'une technique de cathétérisme du canal de Wharton.

Except in cases where stones are present, it is often difficult to catheterize Wharton's duct through the opening when conducting sialography of the submaxillary glands. When direct catheterization is impossible the authors perform indirect catheterization proximal to the opening by turning back a periorificial mucous flap, posteriorly concave, after exposing the canal.

Planar optical waveguides achieved by ion implantation in zinc telluride: general characteristics.

The optical properties of ZnTe in the visible and the ir and the possibilities of realizing waveguides by ion implantation were investigated in this semiconductor. The main characteristics of the refractive index profiles obtained by implantation of light ions (proton, helium, boron) vs dose, energy, thermal annealing, and wavelength are presented. It is shown that these waveguides are the result of both the macroscopic implantation and the microscopic properties of ZnTe where the damages induced by this implantation extend deep into the substrate. This explains the low losses (1-4 dB/cm) measured in these waveguides. A first physical interpretation of the results is proposed, and some assumptions are discussed.

Nematic liquid crystal 1024 bits page composer.

We report design considerations and experimental results concerning a nematic liquid crystal (NLC) cell used in an ac crossbar addressing mode to achieve a page composer for holographic memories. Our display is a 32 x 32 binary elements page composer utilizing the electrooptic (EO) effect of index modulation or field effect in an homeotropic NLC cell, and this composer acts as a spatial wave polarization modulator.

Nematic liquid crystal digital light deflector.

We report the principle of a new type of digital light deflector utilizing the electrooptic effect of index modulation in nematic liquid crystals and the results of the optical tests that were performed on this device. Optical efficiencies and contrasts, electrical operating conditions, and subsequent turnon times are given. A further experiment concerning the deflection of a colored image in incoherent white light is described, which shows that this device seems to be the more interesting for a lot of applications, especially portable ones.