Efficient lysozyme refolding at a high final concentration and a low dilution factor

2012 ◽  
Vol 47 (12) ◽  
pp. 1883-1888 ◽  
Author(s):  
Yun-Chi Chen ◽  
Wei-Tai Lin ◽  
Josephine W. Wu ◽  
Hwai-Shen Liu
Keyword(s):  
Final Concentration ◽  
Dilution Factor ◽  
Lysozyme Refolding

Fasciaton of Pectate Elementary Fibrils

1973 ◽  
Vol 31 ◽  
pp. 60-61
Author(s):  
George F. Leeper
Keyword(s):  
Acid Treatment ◽  
Carbon Film ◽  
Final Concentration ◽  
Cellulose Microfibrils ◽  
Pectic Acid ◽  
Elementary Fibrils

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.

Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

1990 ◽  
Vol 48 (3) ◽  
pp. 90-91
Author(s):  
N. Seki ◽  
Y. Toyama ◽  
T. Nagano
Keyword(s):  
Plasma Membrane ◽  
Essential Role ◽  
Freeze Fracture ◽  
Final Concentration ◽  
Freeze Fracturing ◽  
Physiological Conditions ◽  
Epididymal Maturation ◽  
Cacodylate Buffer ◽  
Sperm Membrane ◽  
Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

Ristocetin and Botrocetin Involve Two Distinct Domains of von Willebrand Factor for Binding to Platelet Membrane Glycoprotein lb

1990 ◽  
Vol 64 (02) ◽  
pp. 326-332 ◽  
Author(s):  
J P Girma ◽  
Y Takahashi ◽  
A Yoshioka ◽  
J Diaz ◽  
D Meyer
Keyword(s):  
Von Willebrand Factor ◽  
Synthetic Peptides ◽  
Competitive Inhibition ◽  
Final Concentration ◽  
Binding Domain ◽  
Platelet Membrane ◽  
Platelet Glycoprotein ◽  
Membrane Glycoprotein ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein lb (GPIb) through two distinct domains on the vWF molecule. This was established by using monoclonal antibodies (MAbs) to vWF and synthetic peptides derived from the sequence of vWF. MAb 322 and MAb NMC/vW 4 both recognize native vWF as well as fragments containing the GPIb-binding domain of vWF, obtained with the following enzymes: trypsin (116 kDa), V-8 pro tease (Spill, 320 kDa) and V-8 protease plus subtilisin (33-28 kDa). Nevertheless, the lack of reciprocal displacement between the two MAbs in experiments of competitive inhibition for binding to vWF demonstrate that their respective epitopes are separate. Both MAbs inhibit 125I-vWF binding to platelet membrane GPIb and vWF-dependent platelet agglutination induced by ristocetin. However, only MAb NMC/vW4 inhibits these functions in the presence of botrocetin and when ristocetin-induced platelet agglutination is inhibited by MAb 322, botrocetin is still able to restore the agglutination. The involvement of two distinct domains of vWF for binding to GPIb in the presence of ristocetin or botrocetin was confirmed in experiments of binding of 125I-vWF to platelets using as competitor synthetic peptides corresponding to the GPIb binding domain of vWF (Cys 474 to Pro 488 and Ser 692 to Pro 708). At a final concentration of 2.5 mM both peptides inhibit more than 90% of the binding of vWF to ristocetin-treated platelets but are unable to modify this binding in the presence of botrocetin. In conclusion our data suggest that botrocetin and ristocetin involve distinct sites on vWF for binding to GPIb.

The Lysis of Artificial Thrombi

1980 ◽  
Vol 43 (01) ◽  
pp. 034-037 ◽  
Author(s):  
Michael J Metcalf
Keyword(s):  
Human Blood ◽  
Final Concentration ◽  
Rabbit Blood ◽  
Factors Influencing ◽  
Dextran 70 ◽  
Chandler Loop ◽  
Loop Technique

SummaryThe susceptibility to lysis of artificial thrombi formed from native rabbit blood in the presence or absence of dextran was determined using the Chandler loop technique. Thrombi of identical weight were formed in the presence of saline or dextran and when spontaneous thrombolysis was allowed to take place, thrombi formed in the presence of dextran 70 were lysed to a greater extent than those formed under control conditions.The possible factors influencing this observation were studied. Increasing concentrations of streptokinase increased the extent of thrombolysis in both control and dextran treated thrombi. Maximal streptokinase induced thrombolysis occurred in the presence of a 2 per cent final concentration of dextran Mw 40,000 and 500,000 and dextran 70 at a final concentration of 1.2 per cent.Increased thrombolysis was not observed when albumin was substituted for dextran.Finally, similar observations were recorded for streptokinase induced thrombolysis using human blood.

Fibrin Polymerization Defect in HIV-infected Patients-Evidence for a Critical Role of Albumin in the Prolongation of Thrombin and Reptilase Clotting Times

1995 ◽  
Vol 73 (03) ◽  
pp. 349-355 ◽  
Author(s):  
Pierre Toulon ◽  
Elyane Frere ◽  
Claude Bachmeyer ◽  
Nathalie Candia ◽  
Philippe Blanche ◽  
...  
Keyword(s):  
Critical Role ◽  
Human Albumin ◽  
Albumin Level ◽  
Final Concentration ◽  
Albumin Concentration ◽  
Clotting Time ◽  
Fibrin Polymerization ◽  
Small Series ◽  
Group 1

SummaryThrombin clotting time (TCT) and reptilase clotting time (RCT) were found significantly prolonged in a series of 72 HIV-infected patients drawn for routine coagulation testing. Both TCT and RCT were highly significantly correlated with albumin (r = -0.64, and r = -0.73 respectively, p<0.0001). TCT and RCT were significantly higher (p<0.0001) in a series of 30 other HIV-infected patients selected on their albumin level below 30.0 g/l (group l) than in 30 HIV-infected patients with albumin level above 40.0 g/l or in 30 HIV-negative controls; the two latter groups were not different. In vitro supplementation of plasma from group 1 patients with purified human albumin up to 45.0 g/l (final concentration) lead to a dramatic shortening effect on both TCT and RCT, which reached normal values. The TCT and RCT of the purified fibrinogen solutions (2.0 g/l final concentration) were not different in the three groups, and normal polymerization curves were obtained in all cases. This further ruled out the presence of any dysfibrinogenemia in the plasma from group 1 patients. Using purified proteins, highly significant correlations were demonstrated between the albumin concentration and the prolongations of both TCT and RCT, which were of the same magnitude order than those found in the patients plasma. These results suggest that hypo-albuminemia is responsible for the acquired fibrin polymerization defect reported in HIV-infected patients. The pathophysiological implication of the low albumin levels was suggested by the finding of decreased albumin levels (associated with prolonged TCT and RCT) in a small series of the eight HIV-infected patients who developed thrombotic complications.

scholarly journals Effects of Dietary Inclusion of Bilberry and Walnut Leaves Powder on the Digestive Performances and Health of Tetra SL Laying Hens

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 823 ◽  
Author(s):  
Roua Gabriela Popescu ◽  
Sorina Nicoleta Voicu ◽  
Gratiela Gradisteanu Pircalabioru ◽  
Alina Ciceu ◽  
Sami Gharbia ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Specific Activity ◽  
Basal Diet ◽  
Intestinal Content ◽  
Final Concentration ◽  
Control Group ◽  
Villus Height ◽  
Tissue Samples ◽  
Walnut Leaves ◽  
Digestive Health

The purpose of this study was to examine the effects of dietary inclusion of two additives at the final concentration of 0.5% bilberry (E1) and 1% walnut (E2) leaves powder in the basal diet on digestive health of hens. A total number of 90 Tetra SL hens were divided into two experimental groups (E1 and E2) and one control group (C) consisting of 30 hens each. After four weeks, 10 hens of each group were sacrificed and tissue samples and intestinal content were taken from the duodenum, jejunum, and cecum in order to perform histological, enzymatic, and microbiota analyses. In groups E1 and E2, the histological analysis showed a significant increase of villus height, resulting probably in increased absorption of nutrients in duodenum and jejunum. A decrease in the specific activity of alpha-amylase and trypsin in E1 and E2 for both duodenum and jejunum compared to the control one was also recorded. In addition, the maltase and invertase specific activity in duodenum increased, a tendency that was kept for maltase but not for invertase in jejunum. The cecal microbiota of E1 and E2 individuals was characterized by an increase of Firmicutes and Lactobacilli and a decrease of Enterobacteriaceae. In conclusion, our results indicate that bilberry and walnut leaves additives in feed may improve the health status of the poultry gastrointestinal tract.

The dilution factor of intravenously injected hemopoietic stem cells

1968 ◽  
Vol 72 (3) ◽  
pp. 229-234 ◽  
Author(s):  
Gastone Matioli ◽  
Helmut Vogel ◽  
Helgard Niewisch
Keyword(s):  
Stem Cells ◽  
Hemopoietic Stem Cells ◽  
Dilution Factor

Simultaneous Determination of Several Elements by Spectrochemical Addition Method … (II) (Tabulation of Analytical Value)

1968 ◽  
Vol 22 (6) ◽  
pp. 749-752 ◽  
Author(s):  
Isoo Masuda ◽  
Tamon Inouye
Keyword(s):  
Simultaneous Determination ◽  
Order Approximation ◽  
Analytical Data ◽  
Zero Order ◽  
Dilution Factor ◽  
Improved Method ◽  
Addition Method ◽  
Zero Order Approximation ◽  
First Approximation

An improved method for the tabulation of analytical data, obtained by addition and successive dilution procedures for spectrochemical analysis, is presented. The author's previous work shows that the solution of the first approximation diverges at some dilution factor smaller than unity when the slope of the working curve of added series is greater than that of unadded series. By obtaining the distance between this position and the origin, and taking it as a correction factor for zero-order approximation, tabulation of the analytical value, in the case of β>α, is carried out. One parameter of the calculation is deleted by normalizing the spectral intensity; therefore, the tabulation can be simplified.

scholarly journals Retinol and retinaldehyde specifically increase α1-proteinase inhibitor in the human cornea

1997 ◽  
Vol 322 (3) ◽  
pp. 751-756 ◽  
Author(s):  
Goran BOŠKOVIĆ ◽  
Sally S. TWINING
Keyword(s):  
Retinoic Acid ◽  
Proteinase Inhibitor ◽  
Culture Medium ◽  
Final Concentration ◽  
Maximal Response ◽  
Human Cornea ◽  
Hep G2 ◽  
Monocytes And Macrophages ◽  
Extrahepatic Tissues ◽  
Mcf 7

α1-Proteinase inhibitor is a serpin and can inhibit most serine proteinases. The cornea is one of several extrahepatic tissues that synthesizes this inhibitor. In the presence of retinol, corneal α1-proteinase inhibitor levels were increased 3.8-fold. The maximal response was achieved 2 h after the addition of retinol (1 μM final concentration) to the culture medium. A similar increase in α1-proteinase inhibitor was observed with retinaldehyde (1 nM final concentration). Concentrations of α1-proteinase inhibitor in other tested cells (Hep G2, CaCo 2, MCF-7, monocytes and macrophages) remained unchanged in the presence of retinol. Retinoic acid did not affect α1-proteinase inhibitor levels in the cornea or the other cells tested. The acute-phase cytokine, interleukin-6, increased α1-proteinase inhibitor levels in all tested tissues/cells except the cornea. These results demonstrate that α1-proteinase inhibitor levels are controlled differently in the cornea compared with other tissues/cells. α1-Proteinase inhibitor is the first protein identified whose levels are regulated by a mechanism supported by retinol and retinaldehyde but not retinoic acid.

A Substance Isolated from Cornus officinalis Enhances the Motility of Human Sperm

1997 ◽  
Vol 25 (03n04) ◽  
pp. 301-306 ◽  
Author(s):  
Hellen Jeng ◽  
Chao Mei Wu ◽  
Shuen-Jiing Su ◽  
Wen-Chang Chang
Keyword(s):  
Sperm Motility ◽  
Crude Extract ◽  
High Performance ◽  
Chinese Herb ◽  
Human Sperm ◽  
Final Concentration ◽  
Dried Fruits ◽  
Sperm Analysis ◽  
Cornus Officinalis ◽  
Phosphate Buffered Saline

The effects of a Chinese herb, Cornus officinalis, on the motility of human sperm was studied. An aqueous extract was prepared from the dried fruits of the herb and used in this study. The crude extract at a final concentration of 0.5 μg/μl in phosphate buffered saline (pH 7.4) increased sperm motility from 25.8 ± 7.7% to 42.8 ± 10.3% (i.e. 68% increase, n = 7), as determined by the computer-aided-sperm-analysis (CASA) method. The crude extract was fractionated by high-performance liquid chromatography (HPLC) into four fractions: Cl , C2, C3 and C4. Their effects on sperm motility were further studied by CASA. Only the C4 fraction showed substantial stimulatory effects on sperm motility. At a concentration of 5 ng/μl, C4 increased the sperm motility from 15.7 ± 3.8% to 34.5 ± 6.4% (i.e. 120% increase, n = 6) by CASA and from 14.9 ± 4.3 to 28.5 ± 8.1 (i.e. 91% increase, n = 8) by transmembrane migration ratio (TMMR) method. This result suggests that C4 is the active component in Cornus officinalis that enhances sperm motility.

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