RESUMEN
While the Fluid Mosaic model (FMM) is widely accepted as an account of the cell membrane's structure-function, its inability to explain certain phenomena has led to the lipid rafts hypothesis (nanodomains) that spontaneous spatiotemporal enriched zones of sphingolipids-cholesterol-protein exist within the membrane. In this text, we propose a novel approach that conceives the cell membrane as a living entity. The questions regarding the FMM revolve around the fact that, although these molecular components are present in many cell types, the membrane does not react in the same way to every external agent; for example, a virus evokes a particular response: why is there some marked specificity of virus (or toxin) attack on one (or some) of these cell types and not to other cell types that nevertheless have a similar membrane protein constitution? The crucial question, to explain this selectivity, would be what determines the specificity of attack on some cells and not others? While FMN assumes a dynamism between macrostates at the intramolecular, intermolecular, and/or collective levels in the membrane, the approach of the lipid raft model presupposes a much greater and more complex dynamics of microstates (even nano-states) of these molecular components. In other words, it implies higher and instantaneous mobility as assemblages ("intentional") and thus, of the membrane itself (as a collective), in response to changes in the internal and external physicochemical environment over a broad spatiotemporal scale. This suggests a mechanism of membrane adaptation in the face of evolutionary constraints. In this text, we propose a paradigmatic approach, from Deleuze-Guattari's philosophy: to conceive the cell membrane as living and not as a mere molecular conglomerate with particular functions and mechanical processes between molecules. For this, we employ the functional concepts of territory and machinic assemblage, whence the vitality of the membrane would allow us to postulate instantaneous updates, within wider spatiotemporal scales in its composition in contrast with the model that dominates as a more plausible explanation nowadays, that does not include smaller spatiotemporal events. If we resort to the concept of territory and its different media components, we could offer a more plausible explanation of the vigorous dynamism in the composition of the cell membrane since it would allow more subtle and complex differentiations between media and thus make visible the constant and instant changes. We propose that the model of nanodomains, understood as a process of dynamic territorialization, offers a more complex and subtle explanation of the instantaneous changes in the cell membrane's composition. This approach expands the explanatory framework for cellular phenomena and reveals their spatiotemporal complexity in accordance with other research.
RESUMEN
Patients with immune conditions and immune-modifying therapies were excluded from the Covid-19 vaccine trials. Studies have shown conflicting response to different vaccines in persons receiving immune suppressors or biologics. The aim of this study is to evaluate humoral and cellular response to Covid-19 vaccines in patients with Inflammatory Bowel Disease (IBD) using biologic and/or immunomodulatory (IMM) therapies. Methods: Participants are adults with IBD receiving biologics or IMM planning to receive a Covid 19 vaccine. Cellular immunity (CD4+ and CD8+ T cell levels) with flow cytometry are measured at baseline and 2 weeks after each vaccine dose. Humoral immunity (antibody titers and neutralizing capacity,VNT%) is analyzed by ELISA at baseline, 2 weeks after each dose, and 6 and 12 months after vaccine. We present the early results of the first 19 subjects. The study is approved by the IRB. Results: 19 subjects (18 in biologics and 1 in IMM) who received 2 doses of the Pfizer-BioNTech vaccine are included. Total IgG antibodies increased 21.13 times after the first dose and 90 times after the second dose. VTN% increased 11.92 times after the first dose and 53.79 times after the second dose. When compared with a healthy control cohort, total IgG antibodies and VTN% were lower in the subjects after the first dose. After the second dose, IgG antibodies increased but remained lower than controls, but VTN% were similar to controls. CD4 and CD8 mean levels had an upward trend after vaccination. Conclusions: Neutralizing capacity response to the vaccine in subjects was similar to a healthy cohort in spite of lower increases in total IgG antibodies. The CD4 and CD8 results observed may support the capacity to mount an effective cellular response in patients on biologics. Larger studies are needed to determine vaccine efficacy in these patients.
RESUMEN
Se presenta un paciente con un dermatofibrosarcoma protuberans en el muslo izquierdo, raro sarcoma de las partes blandas. Se expone el cuadro clínico y la terapéutica efectuada. Se revisa la literatura.
A patient with a dermatofibrosarcoma protuberans on the left thigh, a rare sarcoma of the soft parts, is presented. The clinical picture and the therapeutics used are exposed. Literature is also reviewed.
Un patient atteint d´un dermatofibrosarcome protubérant sur la cuisse gauche, un rare sarcome des parties molles, est présenté. Le tableau clinique et la thérapeutique effectuée sont exposés. La litérature est mise en revue.
RESUMEN
Se realizó un estudio para conocer los niveles de actividad de colinesterasa en los trabajadores del ICA Tibaitatá, y su correlación con la exposición ocupacional a plaguicidas inhibidores de colinesterasa (Organofosforados y Carbamatos). Se tuvieron en cuenta también las siguientes variables: sexo, edad, uso de elementos de protección personal, antiguedad (Tiempo de exposición), ocupación, exposición extraocupacional, embarazo, lactancia, menstruación y presencia de náuseas y síntomas como vómito. El centro de investigación de Tibaitatá, el mas grande del ICA, está ubicado en la sabana de Bogotá y allí se desarrollan trabajos de investigación agrícola y pecuaria que implican exposición a plaguicidas en diversas labores. Las determinaciones de colinesterasa se hicieron por el método colorimétrico de campo, con muestra de sangre capilar y utilizando el equipo de levibond. se consideran anormales o bajos los niveles inferiores al 75 por ciento. Se tomo una muestra de 323 trabajadores, de los cuales 95 (29,4 por ciento) estaban directamente expuestos en su trabajo a plaguicidas inhibidores de colinesterasa. A estos se les aplicaron dos encuestas para conocer las variables y luego se les tomo muestra de sangre capilar, la cual fue procesada en el mismo lugar. Para comprobar la exposicion ocupacional a plaguicidas, se hizo una visita de inspeccion a las distintas dependencias. Para controlar la calidad de los resultados por el metodo de lovibons, se confrontaron los "blancos" de cada sesion con la prueba de colinesterasa por el método electrometrico de Michel, encontrandose correlacionados entre si