scholarly journals The effect of copper source on the stability and activity of α-tocopherol acetate, butylated hydroxytoulene and phytase

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Michael J. Concarr ◽  
Rachel O’Rourke ◽  
Richard A. Murphy

AbstractThe supplementation of Copper (Cu) is essential for the optimum performance of physiological functions, including growth performance and immune function. Cu is usually formulated into animal premixes in the form of inorganic salts, such as sulphates, or organic minerals. Organic minerals are mineral salts that are either complexed or chelated to organic ligands such as proteins, amino acids, and polysaccharides. Cu is often formulated into premixes alongside other essential components such as vitamins, enzymes and synthetic antioxidants, all of which are susceptible to negative interactions with Cu which can detrimentally effect both their stability and activity. The aim of this study was to determine the effect of five different commercially available Cu sources in relation to their effect on the stability of α-tocopherol acetate and on the activity of Butylated Hydroxytoluene (BHT) and three commercially available phytases in vitro. The results determined that Cu source played a significant role in relation to limiting the interactions between Cu and each of the other components in vitro. There were significant differences (p ≤ 0.05), not only, between the inorganic and organic Cu sources but also between some of the individual organic Cu sources in relation to their effect on α-tocopherol acetate, BHT and phytase.

2020 ◽  
pp. 81-87
Author(s):  
Е. G. Kozar ◽  
I. A. Engalycheva ◽  
S. A. Vetrova ◽  
K. S. Muhina ◽  
T. S. Vjurtts ◽  
...  

Relevance. It was to study the variability of the degree of defeat of promising varieties of table carrots by diseases of various etiologies during storage for several years, to determine the level of their polymorphism based on resistance to various types of pathogens and the effectiveness of selection based on an individual immunological assessment of uterine root crops.Materials and methods. The experimental part of the work was performed in 2017-2020 at the FSBSI "Federal Scientific Vegetable Center" with carrot varietal populations of Margosha and Minor. The identification of the species composition of pathogens, the degree of damage, and the level of resistance of variety specimens were carried out in accordance with appropriate methods and determinants. For the immunological assessment of the resistance of carrot cultivars in vitro, the most virulent isolates of different types of fungi were used from the collection of the Laboratory of Immunity and Plant Protection of the Federal Center for Scientific Research.Results. It was established that in the populations of Margosha and Minor under natural storage conditions, the ratio and degree of spread of economically significant diseases differ significantly in different years. Based on an in vitro immunological assessment, a high polymorphism of the individual resistance of genotypes within both populations to the majority of micromycetes was revealed and the most resistant forms to the most dangerous types of pathogens were identified. Immunological analysis of the resulting offspring confirmed the high efficiency of group selection based on a comprehensive assessment of the stability of individual uterine root crops in vivo and in vitro.


2013 ◽  
Vol 53 (2) ◽  
pp. 142 ◽  
Author(s):  
Lin Lu ◽  
Shoufeng Hao ◽  
Liyang Zhang ◽  
Xugang Luo

An in vitro experiment was conducted to investigate the effect of tribasic copper (Cu) chloride [TBCC, Cu2(OH)3Cl] on phytase stability in the premix of weanling piglets at different temperatures in comparison with Cu sulfate. The 225-kg 1% premixes were supplemented with phytase at 50 000 PU/kg and divided into three parts of 75 kg each. One part was supplemented with 6 mg Cu/kg as Cu sulfate (the control), and the other two parts were supplemented with 250 mg Cu/kg either as TBCC or as Cu sulfate. Either 6 or 250 mg Cu/kg is based on the complete diet of weanling piglets. The three premixes were stored at room temperature (20−25°C), natural high temperature (28−36°C), or artificial high temperature (38 ± 2°C) for 0, 10, 20, 30, or 40 days. Copper source, storage temperature and duration of storage, the interaction between Cu source and duration of storage, and the interaction between temperature and duration of storage affected (P < 0.01) phytase activities in the 1% premixes. Phytase activities in the premixes supplemented with TBCC were significantly higher (P < 0.001) than those in the premixes supplemented with CuSO4 at 10 or 20 days of storage. Phytase activities in premixes decreased (P < 0.001) exponentially with duration of storage regardless of Cu source or storage temperature. When the premixes were stored at different duration of storage, phytase activities in the premixes decreased (P < 0.001) linearly as temperature increased. The results from this study indicate that TBCC could maintain the stability of phytase in the piglet premix much more effectively than Cu sulfate regardless of temperature and storage duration.


Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell

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.


Methodology ◽  
2006 ◽  
Vol 2 (4) ◽  
pp. 142-148 ◽  
Author(s):  
Pere J. Ferrando

In the IRT person-fluctuation model, the individual trait levels fluctuate within a single test administration whereas the items have fixed locations. This article studies the relations between the person and item parameters of this model and two central properties of item and test scores: temporal stability and external validity. For temporal stability, formulas are derived for predicting and interpreting item response changes in a test-retest situation on the basis of the individual fluctuations. As for validity, formulas are derived for obtaining disattenuated estimates and for predicting changes in validity in groups with different levels of fluctuation. These latter formulas are related to previous research in the person-fit domain. The results obtained and the relations discussed are illustrated with an empirical example.


1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.


Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.


2019 ◽  
Author(s):  
Candace E. Benjamin ◽  
Zhuo Chen ◽  
Olivia Brohlin ◽  
Hamilton Lee ◽  
Stefanie Boyd ◽  
...  

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>


2020 ◽  
Author(s):  
Emmanuel Kiiza Mwesiga ◽  
Noeline Nakasujja ◽  
Lawrence Nankaba ◽  
Juliet Nakku ◽  
Seggane Musisi

Introduction: Individual and group level interventions have the largest effect on outcomes in patients with the first episode of psychosis. The quality of these individual and group level interventions provided to first-episode psychosis patients in Uganda is unclear.Methods: The study was performed at Butabika National Psychiatric Teaching and referral hospital in Uganda. A retrospective chart review of recently discharged adult in-patients with the first episode of psychosis was first performed to determine the proportion of participants who received the different essential components for individual and group level interventions. From the different proportions, the quality of the services across the individual and group interventions was determined using the first-Episode Psychosis Services Fidelity Scale (FEPS-FS). The FEPS-FS assigns a grade of 1-5 on a Likert scale depending on the proportion of patients received the different components of the intervention. Results: The final sample included 156 first-episode psychosis patients. The median age was 27 years [IOR (24-36)] with 55% of participants of the female gender. 13 essential components across the individual and group interventions were assessed and their quality quantified. All 13 essential components had poor quality with the range of scores on the FEPS-FS of 1-3. Only one essential component assessed (use of single antipsychotics) had moderate quality.Discussion: Among current services at the National psychiatric hospital of Uganda, the essential for individual and group level interventions for psychotic disorders are of low quality. Further studies are required on how the quality of these interventions can be improved.


2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell

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.


2019 ◽  
Vol 16 (4) ◽  
pp. 307-313 ◽  
Author(s):  
Nasrin Zarkar ◽  
Mohammad Ali Nasiri Khalili ◽  
Fathollah Ahmadpour ◽  
Sirus Khodadadi ◽  
Mehdi Zeinoddini

Background: DAB389IL-2 (Denileukin diftitox) as an immunotoxin is a targeted pharmaceutical protein and is the first immunotoxin approved by FDA. It is used for the treatment of various kinds of cancer such as CTCL lymphoma, melanoma, and Leukemia but among all of these, treatment of CTCL has special importance. DAB389IL-2 consists of two distinct parts; the catalytic domain of Diphtheria Toxin (DT) that genetically fused to the whole IL-2. Deamidation is the most important reaction for chemical instability of proteins occurs during manufacture and storage. Deamidation of asparagine residues occurs at a higher rate than glutamine residues. The structure of proteins, temperature and pH are the most important factors that influence the rate of deamidation. Methods: Since there is not any information about deamidation of DAB389IL-2, we studied in silico deamidation by Molecular Dynamic (MD) simulations using GROMACS software. The 3D model of fusion protein DAB389IL-2 was used as a template for deamidation. Then, the stability of deamidated and native form of the drug was calculated. Results: The results of MD simulations were showed that the deamidated form of DAB389IL-2 is more unstable than the normal form. Also, deamidation was carried by incubating DAB389IL-2, 0.3 mg/ml in ammonium hydrogen carbonate for 24 h at 37o C in order to in vitro experiment. Conclusion: The results of in vitro experiment were confirmed outcomes of in silico study. In silico and in vitro experiments were demonstrated that DAB389IL-2 is unstable in deamidated form.


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