design-biaxial-mechanical-loading-bioreactor-for-tissue

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

We  designed a loading device that is capable of applying uniaxial or biaxial  mechanical strain to a tissue engineered biocomposites fabricated for  ...

University of Texas Southwestern Medical Center 

There are two different ways for cells to die: necrosis and apoptosis. Cell death has traditionally been described as necrotic or apoptotic based on morphological criteria. There are controversy about the respective roles of apoptosis and necrosis in cell death resulting from trauma to the central nervous system (CNS). An evaluation of work published since 1997 in which electron microscopy was applied to ascertain the role of apoptosis and necrosis in: spinal cord injury, stroke, and hypoxia/ischemia (H/I) showed evidence for necrosis and apoptosis based on DNA degradation, presence of histones in cytoplasm, and morphological evidence in spinal cord. In the aftermath of stroke, many of the biochemical markers for apoptosis were present but the morphological determinations suggested that necrosis is the major source of post-traumatic cell death. This was not the case in H/I where both biochemical assays and the morphological studies gave more consistent results in a manner similar to the spinal cord injury studies. After H/I, major factors affecting cell death outcomes are DNA damage and repair processes, expression of bcl-like gene products and inflammation-triggered cytokine production.

Delayed cell death signaling in traumatized central nervous system: hypoxia.

Il existe deux fa&ccedil;ons diff&eacute;rentes pour les cellules &agrave; mourir : la n&eacute;crose et l&#39;apoptose. La mort cellulaire est traditionnellement d&eacute;crite comme n&eacute;crotiques ou apoptotic bas&eacute;e sur des crit&egrave;res morphologiques. Il y a controverse sur les r&ocirc;les respectifs de l&#39;apoptose et n&eacute;crose dans la mort cellulaire r&eacute;sultant d&#39;un traumatisme au syst&egrave;me nerveux central (CNS). Une &eacute;valuation des travaux publi&eacute;s depuis 1997 dans lequel la microscopie &eacute;lectronique a &eacute;t&eacute; appliqu&eacute;e afin de d&eacute;terminer le r&ocirc;le de l&#39;apoptose et n&eacute;crose dans : de la moelle &eacute;pini&egrave;re, accidents vasculaires c&eacute;r&eacute;braux et hypoxie/isch&eacute;mie (H / je) montraient des signes de n&eacute;crose et d&#39;apoptose bas&eacute; sur la d&eacute;gradation de l&#39;ADN, pr&eacute;sence des histones dans le cytoplasme et des indices morphologiques de la moelle &eacute;pini&egrave;re. &Agrave; la suite d&#39;un AVC, bon nombre des marqueurs biochimiques de l&#39;apoptose &eacute;taient pr&eacute;sents, mais les d&eacute;terminations morphologiques sugg&egrave;rent que la n&eacute;crose est la principale source de mort cellulaire post-traumatique. Ce n&#39;&eacute;tait pas le cas en H / I o&ugrave; les &eacute;preuves biochimiques et les &eacute;tudes morphologiques a donn&eacute; plus coh&eacute;rente des r&eacute;sultats dans une mani&egrave;re semblable pour les &eacute;tudes de l&eacute;sions de la moelle &eacute;pini&egrave;re. Apr&egrave;s H / I, sont les principaux facteurs influant sur les r&eacute;sultats de mort cellulaire DNA damage and repair traite, expression du g&egrave;ne bcl produits et de la production de cytokines de l&#39;inflammation d&eacute;clench&eacute;e.

Retard de mort cellulaire, la signalisation dans les traumatismes du syst&egrave;me nerveux central : hypoxie.

Ci sono due modi diversi per celle a morire: necrosi e apoptosi. Morte cellulare &egrave; stato tradizionalmente descritto come necrotiche o apoptotiche basato su criteri morfologici. Ci sono polemiche circa i rispettivi ruoli di apoptosi e necrosi morte cellulare derivante da traumi al sistema nervoso centrale (SNC). Una valutazione del lavoro pubblicato dal 1997 in cui la microscopia elettronica &egrave; stata applicata per accertare il ruolo dell&#39;apoptosi e necrosi in: lesioni del midollo spinale, ictus e ischemia/ipossia (H / I) ha mostrato evidenza di necrosi e apoptosi basato sulla degradazione del DNA, presenza di istoni nel citoplasma e prove morfologiche nel midollo spinale. A seguito di ictus, molti dei marcatori biochimici per apoptosi erano presenti ma le determinazioni morfologiche ha suggerito che la necrosi &egrave; la fonte principale di morte delle cellule post-traumatica. Questo non era il caso in H / I dove sia le analisi biochimiche e gli studi morfologici ha dato pi&ugrave; coerente risultati una maniera simile agli studi di lesioni del midollo spinale. Dopo H, sono i principali fattori che influenzano i risultati di morte cellulare processi di danni del DNA e riparazione, espressione del gene bcl-come prodotti e produzione di citochine attivate da infiammazione.

Ritardata la morte delle cellule di segnalazione in traumatizzati del sistema nervoso centrale: ipossia.

Existen dos maneras para que las c&eacute;lulas mueren: necrosis y apoptosis. Muerte celular ha sido tradicionalmente descrita como necr&oacute;tico o apopt&oacute;ticos basan en criterios morfol&oacute;gicos. Hay controversia sobre los papeles respectivos de la apoptosis y necrosis en la muerte celular resultando de trauma al sistema nervioso central (CNS). Una evaluaci&oacute;n del trabajo publicado desde 1997 en que se aplic&oacute; la microscop&iacute;a electr&oacute;nica para determinar el papel de la apoptosis y necrosis en: lesi&oacute;n de la m&eacute;dula espinal, el trazo y la hipoxia/isquemia (H / I) demostr&oacute; evidencia de necrosis y apoptosis basado en la degradaci&oacute;n del ADN, presencia de histonas en el citoplasma y evidencia morfol&oacute;gica en la m&eacute;dula espinal. En la resaca de golpe, muchos de los marcadores bioqu&iacute;micos de apoptosis estaban presentes, pero las determinaciones morfol&oacute;gicas sugirieron que la necrosis es la fuente principal de la muerte celular postraum&aacute;tico. Este no fue el caso en H / I donde Ensayos bioqu&iacute;micos y los estudios morfol&oacute;gicos dieron m&aacute;s consistentes resultados en forma similar a los estudios de lesi&oacute;n de la m&eacute;dula espinal. Despu&eacute;s de H / I, son los principales factores que afectan los resultados de muerte celular procesos de reparaci&oacute;n y da&ntilde;os en el ADN, expresi&oacute;n del gen bcl-como productos y producci&oacute;n de citoquinas desencadenada por la inflamaci&oacute;n.

Danielle Chu

University of Texas Southwestern Medical Center

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering