scholarly journals Metal-dependent properties of metallothionein. Replacement in vitro of zinc in zinc-thionein with copper

1981 ◽  
Vol 199 (2) ◽  
pp. 289-295 ◽  
Author(s):  
K T Suzuki ◽  
T Maitani
Keyword(s):  
Thiol Groups ◽  
Buffer Solution ◽  
Liquid Chromatograph ◽  
Flame Atomic Absorption ◽  
Gel Permeation ◽  
Isoelectric Points ◽  
High Pressure Liquid Chromatograph ◽  
Hydroxy Groups ◽  
Alkaline Buffer Solution

Metal-dependent changes in the properties of metallothionein were investigated in vitro by replacing Zn2+ in zinc-thionein with Cu+ and Cu2+. Metallothionein was separated into isoproteins on a gel-permeation column by elution with alkaline buffer solution, the separation being due to the dissociation of hydroxy groups in the gel material. The two metals in metallothioneins were detected simultaneously by introducing the eluate of the column, which was attached to a high-pressure liquid chromatograph, to two flame atomic-absorption spectrophotometers. Zn2+ in zinc-thionein was replaced with 1.5 and 1 mol. equiv. of Cu+ and Cu2+ respectively. The replacement with Cu2+ accompanied intramolecular oxidation of thiol groups in metallothioneins and the oxidized metallothioneins showed different chromatographic properties from the original ones, probably due to changes in the isoelectric points. The oxidized forms of metallothionein were reducible by mercaptoethanol. Reduction of Cu2+ to Cu+ followed by the replacement of Zn2+ in zinc-thionein with Cu+ occurred in the presence of glutathione.

Switching Valve Designed For High Pressure Liquid Chromatographic Fraction Collection

1979 ◽  
Vol 62 (6) ◽  
pp. 1355-1357
Author(s):  
William O Landen
Keyword(s):  
High Pressure ◽  
Oil Removal ◽  
High Pressure Liquid Chromatographic ◽  
Liquid Chromatograph ◽  
Switching Valve ◽  
Gel Permeation ◽  
In Series ◽  
High Pressure Liquid Chromatograph ◽  
Pass Through ◽  
Liquid Chromatographic

Abstract The use of a collection valve specifically designed for high pressure liquid chromatography is described. Application of the valve to high pressure gel permeation chromatographic (GPC) separation of oil from the vitamin A active fraction of margarine resulted in efficient oil removal after one pass through 2 μStyragel (100A) columns connected in series. Using the normal collection mode of the high pressure liquid chromatograph, 2 passes through the GPC columns were required to adequately resolve the fractions.

The Hierarchic Order of Intermediate Filament Structure and Assembly

1985 ◽  
Vol 43 ◽  
pp. 722-725
Author(s):  
U. Aebi ◽  
E.C. Glavaris ◽  
R. Eichner
Keyword(s):  
Tissue Specificity ◽  
Structural Model ◽  
Eukaryotic Cells ◽  
Cdna Sequencing ◽  
Filament Structure ◽  
Keratin Filaments ◽  
Isoelectric Points ◽  
Immunological Crossreactivity

Five different classes of intermediate-sized filaments (IFs) have been identified in differentiated eukaryotic cells: vimentin in mesenchymal cells, desmin in muscle cells, neurofilaments in nerve cells, glial filaments in glial cells and keratin filaments in epithelial cells. Despite their tissue specificity, all IFs share several common attributes, including immunological crossreactivity, similar morphology (e.g. about 10 nm diameter - hence ‘10-nm filaments’) and the ability to reassemble in vitro from denatured subunits into filaments virtually indistinguishable from those observed in vivo. Further more, despite their proteinchemical heterogeneity (their MWs range from 40 kDa to 200 kDa and their isoelectric points from about 5 to 8), protein and cDNA sequencing of several IF polypeptides (for refs, see 1,2) have provided the framework for a common structural model of all IF subunits.

Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems

2019 ◽  
Vol 16 (10) ◽  
pp. 940-950 ◽  
Author(s):  
Jiandong Yu ◽  
Zhi Chen ◽  
Yan-zhi Yin ◽  
Chaoyuan Tang ◽  
Enying Hu ◽  
...  
Keyword(s):  
Gradient Method ◽  
Encapsulation Efficiency ◽  
Ph Value ◽  
Topical Administration ◽  
Ph Gradient ◽  
Stability Factor ◽  
Buffer Solution ◽  
Skin Delivery ◽  
Skin Retention

Background: In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Methods: Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. Results: A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. Conclusion: In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

scholarly journals Feeding Value Assessment of Substituting Cassava (Manihot esculenta) Residue for Concentrate of Dairy Cows Using an In Vitro Gas Test

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 307
Author(s):  
Yuhui Zheng ◽  
Yanyan Zhao ◽  
Shenglin Xue ◽  
Wei Wang ◽  
Yajing Wang ◽  
...  
Keyword(s):  
Manihot Esculenta ◽  
Rumen Fluid ◽  
Gas Production ◽  
The Other ◽  
Holstein Cows ◽  
Value Assessment ◽  
Buffer Solution ◽  
Feeding Value ◽  
Cassava Residue

The feeding value of replacing concentrate with cassava (Manihot esculenta) residue in the feed of Holstein cows was confirmed using an in vitro gas test. The treatments consisted of 0% (control, CON), 5%, 10%, 15%, 20%, 25%, and 30% inclusion of cassava residue in fermentation culture medium composed of buffer solution (50 mL) and filtrated rumen fluid (25 mL). The parameters analyzed included the kinetics of gas production and fermentation indexes. Forty-eight hours later, there were no significant differences on in vitro dry matter disappearance (IVDMD), pH, and microbial crude protein (MCP) content among treatments (p > 0.05). However, the “cumulative gas production at 48 h” (GP48), the “asymptotic gas production” (A), and the “maximum gas production rate” (RmaxG) all increased linearly or quadratically (p < 0.01). The GP48 was significantly higher in the 25% treatment compared to the other treatments, except for the 30% (p < 0.01). The A was significantly larger in the 25% treatment compared to the other treatments, except for the 20% and 30% (p < 0.01). The RmaxG was distinctly larger in the 25% treatment compared to other treatments (p < 0.01); moreover, the “time at which RmaxG is reached” (TRmaxG) and the “time at which the maximum rate of substrate degradation is reached” (TRmaxS) were significantly higher in the 25% treatment than the CON, 20%, and 30% treatments (p < 0.01). Additionally, the content of ammonia-N (NH3-N) in all treatments showed linearly and quadratically decreases (p < 0.01), whereas total volatile fatty acid (VFA), iso-butyrate, butyrate, and iso-valerate contents changed quadratically (p = 0.02, p = 0.05, p = 0.01, and p = 0.02, respectively); all of these values peaked in the 25% treatment. In summary, the 25% treatment was associated with more in vitro gas and VFA production, indicating that this cassava residue inclusion level may be used to replace concentrate in the feed of Holstein cows. However, these results need to be verified in vivo.

Bacterial chemotaxis to fungal propagules in vitro and in soil

1983 ◽  
Vol 29 (9) ◽  
pp. 1104-1109 ◽  
Author(s):  
D. K. Arora ◽  
A. B. Filonow ◽  
J. L. Lockwood
Keyword(s):  
Sandy Loam ◽  
Phosphate Buffer Solution ◽  
Bacterial Chemotaxis ◽  
Macrophomina Phaseolina ◽  
Buffer Solution ◽  
Erwinia Herbicola ◽  
Cochliobolus Victoriae ◽  
Fungal Propagules ◽  
Loam Soil

Erwinia herbicola, Pseudomonas fluorescens, and P. putida were strongly attracted in vitro to substances exuded by conidia of Cochliobolus victoriae and sclerotia of Macrophomina phaseolina, but not to phosphate buffer solution. Numbers of bacteria attracted to propagules of C. victoriae or M. phaseolina in an unsterilized sandy loam soil were significantly (P = 0.05) greater than background populations occurring in soil saturated with buffer. Chemotactic response was greater to C. victoriae than to M. phaseolina both in vitro and in soil. Results suggest that living fungal propagules may act as attractants for motile bacteria in soil.

Surface Morphological Changes Accompanying Dissolution of Bioactive Glass: Effect of Residual Stress

2008 ◽  
Vol 47-50 ◽  
pp. 1302-1306 ◽  
Author(s):  
John A. Nychka ◽  
Ding Li
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Bioactive Glass ◽  
Morphological Changes ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Mechanochemical Effect ◽  
Dissolution Behaviour ◽  
Glass Surfaces

We report our observations concerning the time evolution of surface morphology occurring during the in vitro immersion of bioactive glass surfaces in contact with phosphate buffer solution. We compare regions under intentionally produced residual stresses via micro-indentation to those where no indentation was performed. The sign of the residual stress is shown to be important for predicting dissolution behaviour; compression retards dissolution, whereas tension enhances dissolution. We analyze our results with a simple model for the work of bond dissociation. We report that a highly constrained residual compressive stress state, such as in an indent, leads to a work deficit in comparison to tension, which accounts for the slower dissolution rate of compressed bioactive glass. Such a mechanochemical effect suggests that the presence of residual stresses from the manufacture of biomedical implants and devices could lead to accelerated or delayed dissolution and that careful control of residual stresses should be sought for predictable performance in dissolvable materials.

scholarly journals Absorption and metabolism of volatile fatty acids by rumen and omasum

2012 ◽  
Vol 36 (1) ◽  
pp. 93-99 ◽  
Author(s):  
João Luiz Pratti Daniel ◽  
João Chrysostomo de Resende Júnior
Keyword(s):  
Fatty Acids ◽  
Mitotic Index ◽  
Volatile Fatty Acids ◽  
Diffusion Chamber ◽  
Serosal Side ◽  
Buffer Solution ◽  
Mucosal Side ◽  
Over Time ◽  
Fractional Absorption

Volatile fatty acids (VFA) absorption and metabolic capacity of rumen and omasum were compared, in vitro. Fragments of rumen wall and omasum laminae were taken from eight adult crossbred bovines. An isolated fragment of the mucosa was fitted in a tissue diffusion chamber. Valeric acid and CrEDTA were added to ruminal fluid and placed on the mucosal side and buffer solution was placed on the serosal side. Fractional absorption rates were measured by exponential VFA:Cr ratio decay over time. Metabolism rate was determined as the difference between VFA absorbed and VFA which appeared on the serosal side over time. Mitotic index was higher in omasum (0.52%) than in rumen epithelium (0.28%). VFA fractional absorption rate was higher in omasum (4.6%/h.cm²) than in rumen (0.4%/h.cm²). Acetate, propionate, butyrate, and valerate showed similar fractional absorption rates in both fragments. Percentage of metabolized acetate and propionate was lower than butyrate and valerate in both stomach compartments. In the rumen, individual VFA metabolism rates were similar (mean of 7.7 , but in the omasum, valerate (90.0 was more metabolized than butyrate (59.6 propionate (69.8 and acetate (51.7 . Correlation between VFA metabolism and mitotic index was positive in the rumen and in the omasum. In conclusion, VFA metabolism and absorption potential per surface of the omasum is higher than that of the rumen. Variations on rumen and omasum absorption capacities occur in the same way, and there are indications that factors capable of stimulating rumen wall proliferation are similarly capable of stimulating omasum walls.

Treatment of local scrubber wastewater for semiconductor by using photo-catalytic ozonation

2009 ◽  
Vol 59 (11) ◽  
pp. 2281-2286 ◽  
Author(s):  
Chung-Yi Chou ◽  
Chien-Pin Huang ◽  
Neng-Chou Shang ◽  
Yue-Hwa Yu
Keyword(s):  
Ion Exchange ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Catalytic Ozonation ◽  
Acidic Condition ◽  
Buffer Solution ◽  
Toc Removal ◽  
Pre Treatment ◽  
Alkaline Buffer Solution

This study investigates the oxidation of local scrubber wastewater (LSW) from semiconductor manufacture by using ozonation, catalytic ozonation (ozone/Al2O3 and ozone/TiO2–Al2O3), and photo-catalytic ozonation (UV/TiO2–Al2O3, ozone/UV and ozone/UV/TiO2–Al2O3). The results show that catalyst Al2O3 and TiO2–Al2O3 promotes the TOC removal under the condition of neutral or alkaline buffer solution during catalytic ozonation of LSW. The Al2O3 induces highest promotion in TOC removal efficiency, which is higher than ozone alone by 26% TOC removal under alkaline buffer solution. However, TiO2–Al2O3 and Al2O3 cannot display the promotion in TOC removal under acidic condition. In addition, a pre-treatment of anion ion-exchange is employed and the result indicates that decreasing the anion ions concentration before AOPs can imply higher TOC removal during AOPs of LSW. In this study, ozone/UV under raw LSW acidic condition and ozone/Al2O3 under alkaline buffer solution present 95% and 88% TOC removal rate respectively and show the higher TOC removal efficiency than other AOPs. Therefore, these two kinds of AOP can serve as the very viable AOP methods in the LSW reclamation for semiconductor.

Use of a flow-injection sample manipulator as an interface between a "high-performance" liquid chromatograph and an atomic absorption spectrophotometer.

1981 ◽  
Vol 27 (9) ◽  
pp. 1546-1550 ◽  
Author(s):  
B W Renoe ◽  
C E Shideler ◽  
J Savory
Keyword(s):  
Atomic Absorption ◽  
Flow Injection ◽  
Metal Binding ◽  
High Performance ◽  
Atomic Absorption Spectrophotometry ◽  
Clinical Samples ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Flame Atomic Absorption ◽  
Column Eluate

Abstract We describe an integrated, molecular-absorbance, atomic absorption instrument for studying metal/ligand binding in clinical samples. For an interface between the "high-performance" liquid chromatograph and the atomic absorption instrument we used a flow-injection sample manipulator, thus allowing both the chromatograph and the atomic absorption detector to operate at their separate optimum conditions. After specimen separation with a gel permeation column, we measured the molecular components of the column eluate by molecular absorbance spectrometry and the atomic components (calcium and magnesium) by flame atomic absorption spectrophotometry. This instrument system is capable of separating and analyzing multiple components within 20 min of injection of the sample on the column. The chromatograms presented demonstrate the utility of the system for investigating metal binding to a variety of ligands in clinical samples.

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