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Geydan T.D.,National University of Colombia | Garzon-Coral C.,Laboratorio Of Biofisica | Garzon-Coral C.,National University of Colombia | Fajardo C.,National University of Colombia | Spinel C.,National University of Colombia
Acta Biologica Colombiana | Year: 2010

The nuclear pore complex (NPC) is a large supramolecular assemble made up of multiple copies of about 30 different protein families, so in total 456 nucleoporines (Nups) span the nuclear envelope of all Eukariotic organisms. The NPC is considered the gate through which all macromolecules must pass in order to achieve nuclearcytoplasmic transport. The aim of this update is to describe the structure, mechanisms and processes involved during the transportation of molecules and how of these processes are regulated by highly dynamic macromolecular interactions with molecules of the NPC which have been described during the past years.

Herrera M.,Laboratorio Of Biofisica | Ondo-Mendez A.,Laboratorio Of Biofisica | Ondo-Mendez A.,French Atomic Energy Commission | Bernal E.,Laboratorio Of Biofisica | Spinel C.,Laboratorio Of Biofisica
Acta Biologica Colombiana | Year: 2010

The morphological and functional unit of the thyroid gland is the follicle - an ovoid closed-structure, constituted by a layer of cubical cells (thyrocytes) that lock up a full lumen of the colloid secreted by themselves. In culture, the structures as well as the function of the follicles are lost rapidly in the first 24 hours. However, if the rat thyroid follicles closed are seeded since the beginning of the culture, these conserve the follicular structure, the thyrocyte morphology and the function even as the thyroid hormone synthesis in a similar way to the gland in vivo. This work describes the isolation and the culture of closed swine thyroid follicles and its morphological analysis. The follicles are isolated by enzymatic and mechanic digestion of the thyroid, then they are cultured in agarose with and without thyrotropin (1 mU/ml, TSH). The swine thyroid tissue obtained has the same characteristics of an in vivo hypothyroid gland, an almost flat epithelium, low quantity of Rough Endoplasmic Reticulum (RER) and Golgi complex (GC), short and very scarce microvillus. The isolated and closed follicles cultivated without TSH preserve the ovoid form and the colloid in the lumen, and the same ultrastructure of the thyroid tissue in vivo, RER and GC, but the length of the microvillus as well as the thickness of the epithelium were increased with the culture time. In the presence of TSH the thickness of the epithelium increases from the first day and the follicular cavities reduce considerably. The isolated and closed follicles preserve their morphology in the long term (8 days) of culture with and without the TSH. Besides, they responded to the stimulus of the TSH reducing the follicular cavity.

Morales-Reyes I.,Metropolitan Autonomous University | Morales-Reyes I.,Laboratorio Of Biofisica | Sesena-Rubfiaro A.,Laboratorio Of Biofisica | Acosta-Garcia M.C.,Metropolitan Autonomous University | And 2 more authors.
Measurement Science and Technology | Year: 2016

It is well known that, in excitable cells, the dynamics of the ion currents (I i) is extremely important to determine both the magnitude and time course of an action potential (A p). To observe these two processes simultaneously, we cultured NG108-15 cells over a multi-walled carbon nanotubes electrode (MWCNTe) surface and arranged a two independent Patch Clamp system configuration (Bi-Patch Clamp). The first system was used in the voltage or current clamp mode, using a glass micropipette as an electrode. The second system was modified to connect the MWCNTe to virtual ground. While the A p was recorded through the micropipette electrode, the MWCNTe was used to measure the underlying whole-cell current. This configuration allowed us to record both the membrane voltage (V m) and the current changes simultaneously. Images acquired by atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicate that cultured cells developed a complex network of neurites, which served to establish the necessary close contact and strong adhesion to the MWCNTe surface. These features were a key factor to obtain the recording of the whole-cell I i with a high signal to noise ratio (SNR). The experimental results were satisfactorily reproduced by a theoretical model developed to simulate the proposed system. Besides the contribution to a better understanding of the fundamental mechanisms involved in cell communication, the developed method could be useful in cell physiology studies, pharmacology and diseases diagnosis. © 2016 IOP Publishing Ltd.

Ochoa C.,Laboratorio Of Biofisica | Ochoa C.,National University of Colombia | Perdomo S.,Laboratorio Of Biofisica | Moreno C.M.,Laboratorio Of Biofisica | And 7 more authors.
Acta Biologica Colombiana | Year: 2010

The Schwann cells (SC) are the glia of the peripheral nerve system. The nervous prostheses are related to the production of autologous SC obtained from peripheral nervous and dorsal root ganglia (DRG). There is a small amount of papers in the literature that report cultures of perineural cells (PC) and endoneural fibroblast (EF) aselements to take account into prostheses. In this work, microdissection process and its importance is described in the sciatic nerve (SN) and the DRG to achieve SC, EF and PC cultures with a purities of 98%. SC grow on different supports with and without mitogens. An elevated percentage of SC were obtained when the epineurium and the perineurium were removed in SN (90% ± 3) and GRD (94% ± 3) before the enzymatic dissociation compared to seventy percentage or eighty percentage. EF adhered in the first twenty four hours and 20% of serum improved their growth. In the first passage, there is 99% SC or EF, and they get confluen during the six and eight days, respectively. PC or the cells of the DRG do not have neither a good dissociation, nor a growth in subcultures; they only grow from the perineurium explants that forms a lamina of several cellular layers more than a monolayer. In conclusion, DRG and SN microdissection and dissociation are indispensable to acquire in few days SC, EF and PC cultures with a high purity from adult animals.

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