FEEDING VALUE OF FORAGE AS FED TO STEERS AND ESTIMATED BY IN VITRO DIGESTION

1970 ◽  
Vol 50 (3) ◽  
pp. 547-555 ◽  
Author(s):  
J. E. TROELSEN ◽  
S. E. BEACOM
Keyword(s):  
Body Weight Gain ◽  
In Vitro Digestion ◽  
Experimental Conditions ◽  
Wide Range ◽  
Digestible Organic Matter ◽  
Feeding Value ◽  
Voluntary Intake ◽  
Highly Correlated

The digestibility and intake of 23 hays and three silages were determined in two experiments with Hereford steers averaging 215 kg at the start of the test. Each forage was fed in a chopped (4 to 6 cm) form as the sole diet to two steers for 56 days. Voluntary intake and body weight gain during the fourth through the seventh week were used as measures of animal performance. Digestibility was determined by collecting all the feces during the eighth week, allowing for a three-day lag between intake and excretion. The forages included grass, legume and cereal hays, and cereal and legume cereal silages produced under a wide range of conditions. The concentration of in vitro digestible organic matter (DOM) in the forage was highly correlated with gain (r = 0.57 and 0.86) and intake of digestible energy (DE) (r = 0.62 and 0.89). The voluntary intake by the steers was comparable with that by sheep in earlier experiments at two other locations, when the intake was based on metabolic body size, and on similar in vitro DOM or in vivo DE concentrations in the forage. Differences in intake between experiments followed the same pattern as feed allowance in excess of intake, but the effect of in vitro DOM or in vivo DE content on intake was apparently the same in each experiment. This supported the theory that regressions of DE intake by sheep on in vitro DOM content of forage will serve as a measure of the feeding value, providing that appropriate experimental conditions are maintained.

scholarly journals Amyloid Beta: Multiple Mechanisms of Toxicity and Only Some Protective Effects?

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Paul Carrillo-Mora ◽  
Rogelio Luna ◽  
Laura Colín-Barenque
Keyword(s):  
Amyloid Beta ◽  
Protective Effects ◽  
Protective Mechanisms ◽  
Experimental Conditions ◽  
Mechanisms Of Toxicity ◽  
Mitochondrial Alterations ◽  
Physiological Properties ◽  
Wide Range

Amyloid beta (Aβ) is a peptide of 39–43 amino acids found in large amounts and forming deposits in the brain tissue of patients with Alzheimer’s disease (AD). For this reason, it has been implicated in the pathophysiology of damage observed in this type of dementia. However, the role of Aβin the pathophysiology of AD is not yet precisely understood. Aβhas been experimentally shown to have a wide range of toxic mechanismsin vivoandin vitro, such as excitotoxicity, mitochondrial alterations, synaptic dysfunction, altered calcium homeostasis, oxidative stress, and so forth. In contrast, Aβhas also shown some interesting neuroprotective and physiological properties under certain experimental conditions, suggesting that both physiological and pathological roles of Aβmay depend on several factors. In this paper, we reviewed both toxic and protective mechanisms of Aβto further explore what their potential roles could be in the pathophysiology of AD. The complete understanding of such apparently opposed effects will also be an important guide for the therapeutic efforts coming in the future.

The use of cell wall organic matter components and in vitro degradability characteristics to predict intake and digestibility of white clover for sheep

1995 ◽  
Vol 46 (6) ◽  
pp. 1111 ◽  
Author(s):  
KS Nandra ◽  
VH Oddy ◽  
JF Ayres ◽  
PJ Nicholls ◽  
B Langevad ◽  
...  
Keyword(s):  
Cell Wall ◽  
Organic Matter ◽  
White Clover ◽  
Good Precision ◽  
Digestible Organic Matter ◽  
Predictive Relations ◽  
Voluntary Intake ◽  
Organic Matter Digestibility

The relations of the laboratory measurement of cell wall organic matter (CWOM) components and of the in vitro degradability characteristics of CWOM with in vivo digestibility and voluntary intake for high quality white clover were investigated. The voluntary intake, apparent digestibility and apparent rumen retention time of CWOM of white clover harvested at various stages of maturity were measured in rumen-cannulated Merino wether sheep. The in vitro degradability characteristics of CWOM of these diets were also measured. This study has quantified strong predictive relations between structural fibre constituents or degradation parameters and both digestibility and intake for white clover. The CWOM, cellulose and hemicellulose contents and potential degradability of CWOM of the white clover predicted in vivo organic matter digestibility with good precision (r2 = 0.74, 0.67, 0.72 and 0.72 respectively). The voluntary intakes of organic matter and digestible organic matter of the white clover were strongly related to CWOM, cellulose and hemicellulose contents and to the rate of degradation of CWOM in the rumen and the fits of these relations were at least as good as those predicting organic matter digestibility. The predictive equations based on CWOM: OMD (g/kg) = 97.6-0.081 (� 0.012) CWOM OMI (g/kg) = 83-0.085 (� 0.018) CWOM DOMI (g/kg) = 71.4-0.098 (� 0.015) CWOM are recommended because of the ease of analysis of CWOM in the laboratory.

scholarly journals Characterization of Andean Blueberry in Bioactive Compounds, Evaluation of Biological Properties and in vitro Bioaccessibility

2020 ◽  
Author(s):  
Nieves Baenas ◽  
Jenny Ruales ◽  
Diego A. Moreno ◽  
Daniel Alejandro Barrio ◽  
Carla M. Stinco ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Bioactive Compounds ◽  
Biological Activities ◽  
In Vitro Digestion ◽  
Biological Properties ◽  
Wide Range ◽  
Zebrafish Embryogenesis

Andean blueberries are wild berries grown and consumed in Ecuador which contain high values of bioactive compounds, mainly anthocyanins, with powerful antioxidant activity. The aim of this study was to evaluate the profile and contents of (poly)phenols and carotenoids in Andean blueberry by HPLC-DAD-MSn and determine a wide range of its biological activities. The antioxidant capacity of this fruit was evaluated in vitro by three different methods and in vivo using the zebrafish animal model, also the toxicity effect was determined by the zebrafish embryogenesis test. Besides, the antimicrobial activity and the capacity of Andean blueberry to produce hemagglutination in blood cells were evaluated. Finally, the bioaccessibility of (poly)phenols and related antioxidant capacity were determined in the different phases of an in vitro digestion. The global results indicated no toxicity of Andean blueberry, weakly bacteriostatic activity, and high contents of anthocyanins and antioxidant capacity, which were partially bioaccesible in vitro (~ 50 % at the final intestinal step), contributing to the knowledge of its health benefits for consumers and its potential use in the food and pharmaceutical industry as functional ingredient.

Prediction of in vivo dry matter, organic matter, and energy digestibilities of silage in in vitro digestion techniques

1971 ◽  
Vol 22 (5) ◽  
pp. 787 ◽  
Author(s):  
GD Brown ◽  
JC Radcliffe
Keyword(s):  
Organic Matter ◽  
Volatile Compounds ◽  
Dry Matter ◽  
In Vitro Digestion ◽  
Digestion Time ◽  
Dry Matter Digestibility ◽  
Highly Correlated ◽  
Ad Libitum Intake

Twenty experimental silages were made from seven pasture species at different stages of maturity. In vivo dry matter, organic matter, and energy digestibilities of the silages were determined at restricted and ad libitum intake levels on standardized pairs of Merino wethers. In vitro dry matter digestibility determinations were made on ground frozen silage and ground oven-dried silage with and without a correction for the loss of volatile compounds during drying. Corrected in vitro dry matter digestibilities of ground oven-dried silage for a 48 hr rumen liquor digestion time gave the most accurate prediction of in vivo dry matter (r = 0.88), organic matter (r = 0.86), and energy (r = 0.74) digestibilities for restricted intake levels. In vitro digestibilities of ground frozen silage more accurately predicted in vivo digestibilities than did in vitro digestibilities of ground oven-dried silage without the correction for volatile losses. In vivo dry matter and organic matter digestibilities were highly correlated (v = 0.97), but both were poorly correlated with in vivo energy digestibilities. In vitro digestion of ground oven-dried silage with a correction for the volatile compounds lost during drying is recommended as a suitable routine determination for predicting the in vivo digestibility of silage.

Evaluation of the Cytotoxicity of the First 20 MEIC Chemicals in Two Hepatoma Cell Lines with Different Xenobiotic Metabolism Capacities

1993 ◽  
Vol 21 (1) ◽  
pp. 65-72
Author(s):  
Anna Maria Bassi ◽  
Ornella Bosco ◽  
Sabrina Brenci ◽  
Daniela Adamo ◽  
Susanna Penco ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Hepatoma Cell ◽  
Biochemical Properties ◽  
Hep G2 ◽  
Experimental Conditions ◽  
Hepatoma Cell Lines ◽  
Wide Range

The cytotoxicity of the first 20 chemicals on the MEIC list was evaluated using two hepatoma cell lines having different xenobiotic metabolic capacities, one derived from the rat (HTC), and one of human origin (Hep G2). Two endpoints were measured to evaluate cytotoxicity: colony-forming ability (CF), and cell viability of the attached monolayer (CV), evaluated as total macromolecular content. The CF test provided the most sensitive endpoint, due to the lower number of exposed cells in comparison with the CV test. Using the CF assay, the Hep G2 cell line showed higher sensitivity than the HTC cell line to some chemicals known to be metabolised in vivo. The IC50s obtained under the different experimental conditions varied as a consequence of phenotypic differences between the cell lines, and of the nature of the endpoints. The most toxic chemicals were malathion, diazepam and amitriptyline (IC50: 0.001-0.1mM). The solvents tested produced the lowest toxic effects (IC50: > 10mM). These findings suggest that hepatoma cell lines possessing various specific enzyme activities could be usefully employed in a battery of tests designed to reproduce in vitro the wide range of biochemical properties expressed by the cells in the whole organism.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Superoxide, Xanthine Oxidase and Platelet Reactions: Further Studies on Mechanisms by which Oxidants Influence Platelets

1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Xanthine Oxidase ◽  
Direct Effect ◽  
Platelet Function ◽  
Experimental Conditions ◽  
Release Reaction

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.

Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Platelet Adhesion ◽  
Umbilical Vein ◽  
Procoagulant Activity ◽  
Experimental Conditions ◽  
Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

Applicability of Instability Index for In vitro Protein Stability Prediction

2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell
Keyword(s):  
Protein Stability ◽  
Caulobacter Crescentus ◽  
Effect Of Temperature ◽  
Instability Index ◽  
Dipeptide Composition ◽  
Experimental Conditions ◽  
The Stability ◽  
Vitro Protein

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.

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