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23 results, page 1 of 3

Influence of cellulase or xylanase on the in vitro rumen gas production and fermentation of corn stover

LAURA HAYDEE VALLEJO HERNANDEZ Abdelfattah Zeidan Mohamed Salem Ahmed E. Kholif MONA MOHAMED MOHAMED YASSEEN ELGHANDOUR Raul Fajardo NALLELY RIVERO PEREZ ADRIAN ZARAGOZA BASTIDA María Dolores Mariezcurrena Berasain (2015)

In vitro gas production (GP) technique was used to investigate effect of exogenous enzymes cellulase (CEL) or xylanase (XYL) at different doses on in vitro fermentation characteristics of corn stover. Enzymes were supplemented at 0 (control), 10, 20, 40 and 80 μg/g DM. Gas production was determined at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation was stopped and supernatant pH was determined, and filtered to determine dry matter (DMD), neutral detergent fiber (NDFD) and acid detergent fiber (ADFD) degradabilities. Interaction effects occurred for enzyme type and dose for all measured gas parameters with exception of the lag time, DMD, organic matter degradability (OMD), NDFD, metabolizable energy (ME), short chain fatty acids (SCFA) and microbial crude protein (MCP) production. Cellulase and XYL increased GP (P<0.05) at different incubation hours with better results at the dose of 40 μg/g DM. The dose 80 μg XYL/g DM had the lowest GP compared to other doses. In addition, CEL and XYL decreased pH with increasing OMD, ME, SCFA and MCP production at 40 μg/ g DM of corn stover. The present results suggested that the level of CEL and XYL at 40 μg/g DM have higher GP than other levels of enzymes, imply this level can be more effectively to improve rumen fermentation; however, the difference of XYL between treatments and control was less than that of CEL.

Article

Cellulase Corn straw Fibrolytic enzyme In vitro fermentation Xylanase BIOLOGÍA Y QUÍMICA

SEM, AFM and CLSM microscopic techniques as tools for characterization of cellulose, polyaluminum and aluminum recovered from Tetra Pak packaging

CARLOS EDUARDO BARRERA DIAZ Liliana Ivette Ávila Córdoba FERNANDO UREÑA NUÑEZ GONZALO MARTINEZ BARRERA VICTOR VARELA GUERRERO LILIANA ROSALES HERNANDEZ (2017)

In this chapter, the characterization of the morphological features of sub-products of Tetra Pak packaging using SEM, AFM and CLSM microscopic techniques is presented. In a first step, the separation of the components of the Tetra Pak was done using hydropulping mechanical process; the principal obtained products include cellulose, aluminium and polyethylene+aluminum. The last one called Polyaluminum. After this, the morphological analysis was obtained. The results show that such microscopy techniques are adequate for describe the high degree of purity of the components after recycling.

Book part

SEM AFM CLSM Microscopy Cellulose Polyaluminum Tetra Pak BIOLOGÍA Y QUÍMICA

Efecto de la metformina sobre marcadores bioquímicosmoleculares y secreción de exosomas en células HUH7 con resistencia a insulina.

JOSE MANUEL VILLALVA PEREZ (2020)

Liver-specific insulin resistance is associated with the development of the main challenges in metabolism resulting in dyslipidemia, hyperinsulinemia and hyperglycemia. In vitro models developed for researching the hepatic insulin resistance are limited and employed cell lines without similar characteristics to primary human hepatocytes.

Master thesis

Insulin resistance Huh7 cells Metformin insulin resistance biomarkers BIOLOGÍA Y QUÍMICA QUÍMICA BIOQUÍMICA

ANALYSIS OF HYBRID PEROVSKITE FILMS (MAPbI3) FABRICATED BY THE ONE AND TWO-STEPS METHODS

Diana Marcela Montoya (2021)

"In this work, the one-step and the two-step methods were used to deposit MAPbI3 perovskite films. For both methods, there are several variables to control the perovskite formation and film quality. The influence of anti-solvent, the time for its addition, and the annealing temperature on the features of perovskite films were studied for the one-step method. The temperature for deposition of the inorganic film was studied for the close-spaced sublimation method, and the time that MAI-solution remains onto the PbI2 film before the spin process began was studied for spin-coating with sequential deposition methods."

Doctoral thesis

Perovskite Solar cells MAPbI3 CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA ÓPTICA

Biocompatibility of nitrogen-doped multiwalled carbon nanotubes with murine fibroblasts and human hematopoietic stem cells

José Gil Munguía López Rodrigo Juárez Emilio Muñoz Sandoval Marco Antonio Kalixto Sánchez Joseph Kinsella Antonio de León Rodríguez (2019)

"Chemical vapor deposition (CVD) methods to create carbon nanotubes (CNTs) with specific dopant atoms have been of interest in biomedical applications due to the relative ease of synthesis of doped CNTs with controlled physical properties. However, CNTs generated from CVD are often heterogeneous in chemical functionality, size, aspect ratio, number of walls, and conducting properties resulting in potential inconsistencies during measurement of the physiological activity of cell-CNT interactions. In this work, the biocompatibility of nitrogen-doped multiwalled carbon nanotubes (CNx) with both murine fibroblasts and human hematopoietic stem cells (hHSC) was evaluated. CNx were synthesized by CVD, purified, characterized, and classified into three fractions designated as small-CNx (S-CNx), medium (M-CNx), and large (L-CNx). Mammalian cells were incubated with CNx doses between 0.07 and 70 mu g/mL, and cell viability was evaluated. hHSC and murine fibroblast both demonstrated non-significant differences in proliferation rates when exposed to M-CN, whereas, either cells experienced inhibited growth following exposure to either S-CNx and L-CNx under the same conditions. In this work, it has been demonstrated that CNTs produced by CVD have differences on the biocompatibility with mammalian cells, but the M-CNx could be a great candidate for biomedical applications."

Article

Nanomaterials Nitrogen-doped carbon nanotubes Murine cells Stem cells Biomedical applications BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Expansion of human hematopoietic stem cells for transplantation: trends and perspectives

Hera Andrade Zaldívar MARTHA LETICIA SANTOS MARTINEZ Antonio de León Rodríguez (2008)

"Umbilical cord blood transplantation is clinically limited by its low progenitor cell content. Ex vivo expansion has become an alternative to increase the cell dose available for transplants. Expansion has been evaluated in several ways such as static cultures combining growth factors or mimicking the natural microenvironment using co-culture systems. However, static cultures have a small volume capacity and therefore large-scale expansion has been addressed using bioreactors. These and other biotechnological approaches for the expansion of hematopoietic progenitors and their utility to study several aspects of hematopoietic stem cell biology are discussed here."

Article

2D-culture 3D-culture Human cells Leukemia Rotating wall vessel Stirred tank Transplant CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Novel fusion protein derived from vasostatin 30 and vasoinhibin II-14.1 potently inhibits coronary endothelial cell proliferation

GABRIELA VAZQUEZ RODRIGUEZ María del Carmen González Castillo Antonio de León Rodríguez (2013)

"Angiogenesis has been considered an important target for cancer therapy. The inhibition of angiogenesis represents a promising strategy for anti-cancer treatment, tumor growth inhibition, and metastasis. Vasostatin 30 (Vs30), and the 14.1 kDa vasoinhibin (Vi-II-14.1) are two peptides with remarkable anti-tumor and anti-angiogenic effect. The aim of this study was to produce a novel fusion protein between Vs30 and Vi-II-14.1, denominated VS_VI, to obtain a new protein with higher biological activity. The protein fusion genes were cloned into a T7 promoter-based vector, expressed in Escherichia coli BL21-SI and purified by affinity column chromatography. In vitro assays showed that the recombinant fusion protein inhibited rat coronary endothelial cell proliferation at 65.5 % at 10 nM, whereas recombinant Vs30 and Vi-II-14.1 inhibited at 33 and 50.5 % respectively, at the same concentration. The results showed that VS_VI is significantly more active than the Vs30 and Vi-II-14.1 separately. In addition, a practical classification of the vasoinhibins based on the peptide origin and theoretical molecular weight is proposed. This is the first study to produce a new fusion protein derived from Vs30 and Vi-II-14.1, both of them proposed as promising therapeutic agents."

Article

Angiogenesis Endothelium Cell proliferation Fusion protein Recombinant protein BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA MOLECULAR BIOLOGÍA MOLECULAR

Paracrine roles of senescence in promoting tumourigenesis

JOSE MARIO GONZALEZ MELJEM John Apps Helen Fraser Juan Pedro Martinez-Barbera (2018)

Senescent cells activate genetic programmes that irreversibly inhibit cellular proliferation, but also endow these cells with distinctive metabolic and signalling phenotypes. Although senescence has historically been considered a protective mechanism against tumourigenesis, the activities of senescent cells are increasingly being associated with age-related diseases, including cancer. An important feature of senescent cells is the secretion of a vast array of pro-inflammatory cytokines, chemokines, and growth factors collectively known as the senescence-associated secretory phenotype (SASP). Recent research has shown that SASP paracrine signalling can mediate several pro-tumourigenic effects, such as enhancing malignant phenotypes and promoting tumour initiation. In this review, we summarise the paracrine activities of senescent cells and their role in tumourigenesis through direct effects on growth and proliferation of tumour cells, tumour angiogenesis, invasion and metastasis, cellular reprogramming and emergence of tumour-initiating cells, and tumour interactions with the local immune environment. The evidence described here suggests cellular senescence acts as a double-edged sword in cancer pathogenesis, which demands further attention in order to support the use of senolytic or SASP-modulating compounds for cancer treatment.

Article

MEDICINA Y CIENCIAS DE LA SALUD Ciencias médicas Ciencias clínicas Geriatría Senectud Aging Microambiente celular Cellular microenvironment Microambiente tumoral Tumor microenvironment Senescencia celular Cellular senescence Comunicación paracrina Paracrine communication Carcinogenesis

Active telomerase during leaf growth and increase of age in plants from Agave tequilana var. Azul

Zamaria Yoselín de la Torre Espinosa FELIPE ALONSO BARREDO POOL Enrique Castaño de la Serna Lorenzo Felipe Sánchez Teyer (2020)

In plants, previous studies show that telomerase activity contributes to the maintenance of telomeric length for the proper development of organs and tissues. In this work, we investigated telomerase activity in A. tequilana during several years of cultivation. We found that during growth of the leaf there are two crucial phases: (1) the onset of cell elongation in 3 years and (2) differentiation of vascular bundles in 6 years. This coincides with the ages where the highest telomerase activity is seen. Therefore indicates that telomerase is associated with cellular activities such as; elongation, division, and cell differentiation. Likewise, we detected high activity during the period of vegetative growth, indicating that telomerase also contributes to telomeric maintenance on the leaf in A. tequilana.

Article

AGAVE TEQUILANA TELOMERASE ACTIVITY DEVELOPMENT GROWTH LEAF CELL PROLIFERATION BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA MOLECULAR DE PLANTAS GENÉTICA MOLECULAR DE PLANTAS

Directing the self-assembly of tumour spheroids by bioprinting cellular heterogeneous models within alginate/gelatin hydrogels

Tao Jiang José Gil Munguía López SALVADOR FLORES TORRES Joel Grant Sanahan Vijayakumar Antonio de León Rodríguez Joseph Kinsella (2017)

"Human tumour progression is a dynamic process involving diverse biological and biochemical events such as genetic mutation and selection in addition to physical, chemical, and mechanical events occurring between cells and the tumour microenvironment. Using 3D bioprinting we have developed a method to embed MDA-MB-231 triple negative breast cancer cells, and IMR-90 fibroblast cells, within a cross-linked alginate/gelatin matrix at specific initial locations relative to each other. After 7 days of co-culture the MDA-MB-231 cells begin to form multicellular tumour spheroids (MCTS) that increase in size and frequency over time. After similar to 15 days the IMR-90 stromal fibroblast cells migrate through a non-cellularized region of the hydrogel matrix and infiltrate the MDA-MB-231 spheroids creating mixed MDA-MB-231/IMR-90 MCTS. This study provides a proof-of-concept that biomimetic in vitro tissue coculture models bioprinted with both breast cancer cells and fibroblasts will result in MCTS that can be maintained for durations of several weeks."

Article

Biomaterials – cells Biomedical engineering Cancer models Tissue engineering INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS CIENCIAS TECNOLÓGICAS