Rumen function in vivo and in vitro in sheep fed Leucaena leucocephala

2015 ◽  
Vol 47 (4) ◽  
pp. 757-764 ◽  
Author(s):  
Marcos Antonio Barros-Rodríguez ◽  
Francisco Javier Solorio-Sánchez ◽  
Carlos Alfredo Sandoval-Castro ◽  
Athol Klieve ◽  
Rafael Antonio Rojas-Herrera ◽  
...  
Keyword(s):  
Leucaena Leucocephala

scholarly journals In vitro production of gases with mixtures of Hyparrhenia rufa (Nees) and Leucaena leucocephala (Lam)

2021 ◽  
Vol 13 (11) ◽  
Author(s):  
CÁNDIDO ENRIQUE GUERRA MEDINA ◽  
Alejandro Ley de Coss ◽  
Carlos Hugo Avendaño Arrazate ◽  
José Andrés Reyes Guti´´errez ◽  
Esaú de Jesús Pérez Luna
Keyword(s):  
Leucaena Leucocephala ◽  
In Vitro Production ◽  
Hyparrhenia Rufa ◽  
Vitro Production

Objetivo. Evaluar in vitro la producción de gases totales y metano (CH4) en diferentes mezclas de Hyparrhenia ruffa (Hr) y Leucaena leucocephala (Ll). Diseño/metodología/aproximación: En biodigestores herméticos con 200 mL de medio de cultivo se incubaron por triplicado 20 g de los siguientes tratamientos: T1: 100 % Hr, T2: 80 % Hr + 20 % Ll, T3: 60 % Hr + 40 % Ll, T4: 40 % Hr + 60 % Ll; fueron inoculados con 20 mL de líquido ruminal fresco y se incubaron a 38 ± 0.5 °C durante 24, 48, 72 y 96 h. Se midió la producción de gases totales y CH4; los datos se analizaron en un diseño completamente al azar. Resultados: Al adicionar 20 %, 40% y 60% de Ll en mezcla con Hr, disminuyó la fibra detergente neutro (FDN), fibra detergente ácido (FDA), producción de gases totales y CH4; mientras que el contenido de proteína cruda aumentó. Limitaciones del estudio/implicaciones: Se requiere hacer estudios in vivo/al incluir cantidades mayores de 20 % de Ll se puede mejorar la eficiencia de utilización de la energía. Hallazgos/conclusiones: Al adicionar más del 20 % de L. leucocephala en una mezcla con H. ruffa disminuye la producción de gases totales y CH4.  

EVALUACIÓN IN VITRO DEL POTENCIAL ANTIMETANOGÉNICO DE FOLLAJES TROPICALES COMO ESTRATEGIA DE ALIMENTACIÓN PARA RUMIANTES

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
M. Ramírez-Mella
Keyword(s):  
Leucaena Leucocephala ◽  
Albizia Lebbeck ◽  
Guazuma Ulmifolia

Objetivo: El objetivo de este estudio fue evaluar el efecto del follaje de Leucaena leucocephala, Albizia lebbeck, Piscidia piscipula (Fabaceae) y Guazuma ulmifolia (Malvaceae) al 30% de inclusión sobre la producción de gas, producción de metano y digestibilidad de la materia seca in vitro. Diseño/metodología/aproximación: Se determinó la composición química de las mezclas y del pasto Cynodon plectostachyus (Poaceae). La digestibilidad de la materia seca y producción de gas se determinaron in vitro a las 1, 2, 3, 6, 9, 12, 16, 20 y 24 h de incubación. La concentración de metano se determinó con NaOH. Resultados: La mezcla con 30% de Leucaena leucochepala posee el contenido de PC más elevado, mientras que la de Piscidia piscipula el más bajo. No hubo diferencias en la producción de gas a los diferentes tiempos, ni tampoco en la producción de metano; sin embargo, la incorporación de Guazuma ulmifolia y Piscidia piscipula sí afectó negativamente la digestibilidad de la materia seca, disminuyéndola en alrededor de 9% (P<0.05). Limitaciones del estudio/implicaciones: La combinación al 30% de Leucaena leucocephala, Albizia lebbeck, Piscidia piscipula y Guazuma ulmifolia, con Cynodon plectostachyus no disminuyó la producción de metano in vitro. Hallazgos/conclusiones: Se afectó negativamente la digestibilidad de la materia seca cuando se incluyó follaje de Piscidia piscipula y Guazuma ulmifolia; no obstante, se requieren confirmar los resultados obtenidos realizando estudios in vivo y evaluando los cambios en la microbiota ruminal.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

Specific Labeling of Protein Domains with Antibody Fragments

1981 ◽  
Vol 39 ◽  
pp. 416-417
Author(s):  
U. Aebi ◽  
L.E. Buhle ◽  
W.E. Fowler
Keyword(s):  
Image Processing ◽  
Specific Protein ◽  
Antibody Fragments ◽  
Supramolecular Organization ◽  
Two Dimensional ◽  
Ordered Structures ◽  
Virus Capsids ◽  
Processing Techniques

Many important supramolecular structures such as filaments, microtubules, virus capsids and certain membrane proteins and bacterial cell walls exist as ordered polymers or two-dimensional crystalline arrays in vivo. In several instances it has been possible to induce soluble proteins to form ordered polymers or two-dimensional crystalline arrays in vitro. In both cases a combination of electron microscopy of negatively stained specimens with analog or digital image processing techniques has proven extremely useful for elucidating the molecular and supramolecular organization of the constituent proteins. However from the reconstructed stain exclusion patterns it is often difficult to identify distinct stain excluding regions with specific protein subunits. To this end it has been demonstrated that in some cases this ambiguity can be resolved by a combination of stoichiometric labeling of the ordered structures with subunit-specific antibody fragments (e.g. Fab) and image processing of the electron micrographs recorded from labeled and unlabeled structures.

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