ABSTRACT
Cardiovascular diseases are the leading cause of death in the world, cell therapies have been shown to recover cardiac function in animal models. Biomaterials used as scaffolds can solve some of the problems that cell therapies currently have, plasma polymerized pyrrole (PPPy) is a biomaterial that has been shown to promote cell adhesion and survival. The present research aimed to study PPPy nanoparticles (PPPyN) interaction with adult rat ventricular cardiomyocytes (ARVC), to explore whether PPPyN could be employed as a nanoscaffold and develop cardiac microtissues. PPPyN with a mean diameter of 330 nm were obtained, the infrared spectrum showed that some pyrrole rings are fragmented and that some fragments of the ring can be dehydrogenated during plasma synthesis, it also showed the presence of amino groups in the structure of PPPyN. PPPyN had a significant impact on the ARVC´s shape, delaying dedifferentiation, necrosis, and apoptosis processes, moreover, the cardiomyocytes formed cell aggregates up to 1.12 mm2 with some aligned cardiomyocytes and generated fibers on its surface similar to cardiac extracellular matrix. PPPyN served as a scaffold for adult ARVC. Our results indicate that PPPyN-scaffold is a biomaterial that could have potential application in cardiac cell therapy (CCT).
Subject(s)
Myocytes, Cardiac/drug effects , Nanoparticles/chemistry , Pyrroles/pharmacology , Animals , Cell Dedifferentiation/drug effects , Cells, Cultured , Down-Regulation/drug effects , Extracellular Matrix/chemistry , Extracellular Matrix/drug effects , Heart Ventricles/cytology , Heart Ventricles/drug effects , Male , Materials Testing , Myocytes, Cardiac/physiology , Plasma Gases/pharmacology , Polymerization/drug effects , Pyrroles/chemistry , Rats , Rats, WistarABSTRACT
The transition between sinoatrial cells and atrial cells in the heart is not fully understood. Here we focus on cell-to-cell mathematical models involving typical sinoatrial cells and atrial cells connected with experimentally observed conductance values. We are interested mainly in the geometry of the microstructure of the conduction paths in the sinoatrial node. We show with some models that appropriate source-sink relationships between atrial and sinoatrial cells may occur according to certain geometric arrangements.
Subject(s)
Heart Atria/cytology , Models, Biological , Nerve Net/cytology , Sinoatrial Node/cytology , Animals , RabbitsABSTRACT
In growing cells, apurinic/apyrimidinic (AP) sites generated spontaneously or resulting from the enzymatic elimination of oxidized bases must be processed by AP endonucleases before they compromise cell integrity. Here, we investigated how AP sites and the processing of these noncoding lesions by the AP endonucleases Nfo, ExoA, and Nth contribute to the production of mutations (hisC952, metB5, and leuC427) in starved cells of the Bacillus subtilis YB955 strain. Interestingly, cells from this strain that were deficient for Nfo, ExoA, and Nth accumulated a greater amount of AP sites in the stationary phase than during exponential growth. Moreover, under growth-limiting conditions, the triple nfo exoA nth knockout strain significantly increased the amounts of adaptive his, met, and leu revertants produced by the B. subtilis YB955 parental strain. Of note, the number of stationary-phase-associated reversions in the his, met, and leu alleles produced by the nfo exoA nth strain was significantly decreased following disruption of polX. In contrast, during growth, the reversion rates in the three alleles tested were significantly increased in cells of the nfo exoA nth knockout strain deficient for polymerase X (PolX). Therefore, we postulate that adaptive mutations in B. subtilis can be generated through a novel mechanism mediated by error-prone processing of AP sites accumulated in the stationary phase by the PolX DNA polymerase.
Subject(s)
Adaptation, Biological , Bacillus subtilis/growth & development , Bacillus subtilis/genetics , DNA Damage , DNA Repair , DNA-Directed DNA Polymerase/metabolism , DNA Repair Enzymes/metabolism , DNA-(Apurinic or Apyrimidinic Site) Lyase/metabolism , MutationABSTRACT
Los tumores benignos de ovario son mas comunes en pacientes jóvenes en edad reproductiva a diferencia de la mayor parte de las neoplasias malignas de ovario que se presentan en pacientes de mas edad. Las masas anexiales benignas son unilaterales, pueden llegar a alcanzar grandes tamaños y generan poca sintomatología a las pacientes...
Subject(s)
Female , Epithelial Cells/classification , Abdominal Neoplasms/diagnosis , Abdominal Neoplasms/pathologyABSTRACT
El efecto de un nuevo anticonvulsionantem la 3-hidroxi, 3-etil, 3-fenil propionamida (HEPP) sobre las propiedades eléctricas de neuronas CA3 de hipocampo de rata, se estudió en rebanadas por medio de microelectrodos. Cuando se aplicaron pulsos de corriente depolarizante, la respuesta de las neuronas fueron de dos tipos. En un grupo de neuronas, la respuesta consistió en un número variable de potencias de acción cuya frecuencia aumentó al incrementar la intensidad de la corriente mientras que el otro grupo respondió con una ráfaga (burst) de potenciales de acción al inicio del pulso seguida de una biperpolarización de amplitud variable. En presencia de 50 M de HEPP, ocurrió un aumento reversible en la resistencia de entrada de la célula y del umbral del potencial de acción. No se conocen todavía los mecanismos iónicos para esta respuesta
