UPTAKE OF CORTICOSTEROIDS, RELATED STEROIDS AND THEIR WATER SOLUBLE ESTERS BY HUMAN ERYTHROCYTES

1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S37-S52 ◽  
Author(s):  
K. N. Agarwal ◽  
H. Carstensen

ABSTRACT The influence of different factors upon the affinity of human erythrocytes for corticosteroids was studied in vitro in a phosphate buffer. Properties connected with the erythrocytes per se were found to be of importance for the binding of the steroids. Methods were developed for extraction, separation and estimation of water soluble esters of corticosteroids.

2021 ◽  
Vol 64 (2) ◽  
pp. 401-411
Author(s):  
Noura Saïed ◽  
Mohamed Khelifi ◽  
Annick Bertrand ◽  
Gaëtan F. Tremblay ◽  
Mohammed Aider

HighlightsJuice extraction resulted in a decrease in the nutritive value of the bagasse as compared with the initial biomass.Silages made from the second pressing bagasse were well conserved.Sweet sorghum silage has a better nutritive value than sweet pearl millet.Abstract. Pressing the biomass of sweet sorghum and sweet pearl millet in-field is one of the suggested options for bioethanol production. The extracted juice can be delivered to an ethanol plant, and the bagasse (pressing residue) can be used for ruminant feeding. Efficient carbohydrate extraction is highly important for good ethanol yield. However, enough carbohydrates must remain in the bagasse for its adequate conservation as silage. In this study, the ensilability and the chemical composition of the second pressing bagasse of sweet sorghum and sweet pearl millet were investigated. The bagasse was obtained following a second pressing of the first pressing bagasse after its impregnation with water based on three water:bagasse ratios (0.5, 1, and 1.5). Results indicated that water:bagasse ratio did not affect water-soluble carbohydrate (WSC) extraction for both crops. The second pressing bagasse of sweet sorghum and sweet pearl millet contained 80.5 ±4.6 and 60 ±4.6 g of WSC kg-1 dry matter (DM), respectively. The second pressing bagasse of both crops had reduced nutritive value compared to the initial biomass, i.e., higher neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations along with lower non-structural carbohydrate (NSC) concentration, in vitro true digestibility of DM (IVTD), and in vitro NDF digestibility (NDFd). The second pressing bagasses of both crops also showed good ensilability, but sweet sorghum bagasse silages were of better nutritive value than sweet pearl millet bagasse silages (ADF = 446.2 ±3.7 vs. 463.2 ±3.7 g kg-1 DM, IVTD = 813.8 ±3.4 vs. 708.8 ±6.8 g kg-1 DM, and NDFd = 741.8 ±4.8 vs. 596.2 ±8.5 g kg-1 NDF, respectively). The water:bagasse ratio used for bagasse impregnation before the second pressing only affected the NDF concentration of silages, as a higher NDF concentration was obtained with a water:bagasse ratio of 1.5. Sweet sorghum and sweet pearl millet can be considered dual-purpose crops; the extracted juice can be fermented into ethanol, and the second pressing bagasse can be used to make good-quality silage. Keywords: Bagasse impregnation, Nutritive value, Silage, Sweet pearl millet, Sweet sorghum, Water-soluble carbohydrates.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Vivek Kumar Gupta ◽  
Rajnish Pal ◽  
Nikhat Jamal Siddiqi ◽  
Bechan Sharma

Lead induced neurotoxicity in the people engaged in different occupations has received wide attention but very little studies have been carried out to monitor occupational neurotoxicity directly due to lead exposure using biochemical methods. In the present paper an endeavour has been made in order to assess the lead mediated neurotoxicity by in vitro assay of the activity of acetylcholinesterase (AChE) from human erythrocytes in presence of different concentrations of lead. The results suggested that the activity of this enzyme was localized in membrane bound fraction and it was found to be highly stable up to 30 days when stored at −20°C in phosphate buffer (50 mM, pH 7.4) containing 0.2% Triton X-100. The erythrocyte’s AChE exhibited Km for acetylcholinesterase to be 0.1 mM. Lead caused sharp inhibition of the enzyme and its IC50 value was computed to be 1.34 mM. The inhibition of the enzyme by lead was found to be of uncompetitive type (Ki value, 3.6 mM) which negatively influenced both the Vmax and the enzyme-substrate binding affinity. Taken together, these results indicate that AChE from human erythrocytes could be exploited as a surrogate biomarker of lead induced neurotoxicity particularly in the people occupationally exposed to lead.


1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S3-S27 ◽  
Author(s):  
Kailash N. Agarwal ◽  
Lars Garby

ABSTRACT The effect of different corticosteroids on the lysis of human erythrocytes caused by sulfhydryl inhibitors, mechanical stress and whole blood incubation was investigated. Several of the corticosteroids inhibited the lysis obtained under these conditions. Some conclusions were drawn regarding the molecular configuration required for the inhibitory effect.


Blood ◽  
1955 ◽  
Vol 10 (6) ◽  
pp. 646-649 ◽  
Author(s):  
DONALD A. SUTHERLAND ◽  
MARY SUE MCCALL

Abstract 1. The deviation from a rectilinear form of the complex curvilinear curves of erythrocyte decay produced by the in vitro tagging of the cells with Na2Cr51O4 is not a result of the in vitro tagging procedure per se. 2. Human erythrocytes can be tagged its vivo with Na2Cr51O4. One can determine the in vivo survival of such cells if the gamma detecting unit is sufficiently sensitive and the amount of radiochromium used is sufficient. Such decay curves are similar to those produced by the in vitro Cr51 tagging method. 3. The in vivo method permits a study of the life span of erythrocytes in patients who have a very active cold agglutinin or in whom the cells are easily hemolyzed by mechanical trauma.


1994 ◽  
Vol 5 (6) ◽  
pp. 387-394 ◽  
Author(s):  
H. Schott ◽  
M. P. Häussler ◽  
P. Gowland ◽  
D. H. Horber ◽  
R. A. Schwendener

N4-hexadecyl-5′-0-(4-monomethoxytrityl)-2′-deoxycytidine-3′-hydrogenphosphate was reacted with 3′-azido-2′,3′-dideoxythymidine (AZT) according to the hydrogenphosphate method to yield N4-hexadecyl-2′-deoxycytidylyl-(3′-5)-3′-azido-2′,3′-dideoxythymidine. N4-palmitoyl-5′-O-(4-monomethoxytrityl)-2′-deoxycytidine-3′-(2-chlorophenyl)-phosphate was condensed to AZT using the triester method to give N4-palmitoyl-2′-deoxycytidylyl-(3′-5′)-3,-azido-2′,3′-dideoxythymidine. Both dinucleosidephosphates have amphiphilic properties and represent a new class of AZT derivatives in which the polar AZT-5′-monophosphate is masked with lipophilic deoxycytidine residues of variable stability. The AZT derivatives are water soluble, by forming micelles, and as a result of their amphiphilic nature, they can be incorporated into the lipid membranes of liposomes. In contrast to the micellar drug preparations, the liposomal formulations were shown to exert no lytic activity on human erythrocytes. Both AZT derivatives have anti HIV-1 activity in vitro.


1965 ◽  
Vol 48 (4) ◽  
pp. 656-663 ◽  
Author(s):  
R. Hempel ◽  
F. Neumann

ABSTRACT Various water-soluble steroids were tested in vitro on the isolated rat uterus for their oxytocin-antagonistic activities. Using progestional agents (19-nor-17α-hydroxyprogesterone-17-hemisulfate-sodium, Δ1,6-17α-hydroxyprogesterone-17-hemisulfate-sodium) oestrogens (oestrone-hemisulfate-sodium), and corticoids (dexamethasone-21-hemisulfate-sodium) it was possible to suppress both the oxytocin-induced single contraction and the spontaneous rhythm intensified by oxytocin. Except for the Δ1,6-17α-hydroxyprogesterone-sulfate-sodium, these compounds were unable to inhibit the single contractions of the uterus induced by serotonin, bradykinin and barium chloride. Following the administration of a mixture of the different watersoluble steroids an additional effect was observed. Based on these results, it can be assumed that the oxytocinantagonistic effect represents an activity per se which is peculiar to certain steroid structures.


Author(s):  
Caroline A. Miller ◽  
David H. Nichols ◽  
Richard F. Murphy

Gastrin is a small peptide capable of both stimulating gastric acid secretion and acting as an enteric growth factor. Known functions of eosinophils in the rat stomach are related to immunological defense. Here we demonstrate the binding of biotinylated gastrin to rat stomach eosinophils in the electron microscope. Small pieces of stomach were fixed by immersion in 4% paraformaldehyde/0.1% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4 for 1 hour. The tissue was then cryoprotected in 30% sucrose/0.1 M phosphate buffer, transferred to Tissue Tek OCT compound and frozen in isopentane cooled with liquid nitrogen. Transverse cryostat sections were cut at 25 μm, thawed in PBS and free floating sections exposed to 10−5 M biotinylated 1-17 gastrin (human sequence; Peninsula Labs) for 1 hour. Controls omitted the biotinylated gastrin from this step. Sections were then rinsed 3X in PBS and exposed to either:1).a 1:50 dilution of 10 nm Extravidin colloidal gold (Sigma) for 2 hours, or2).an avidin-biotin-alkaline phosphatase complex (ABC-AP;Vector) for 1 hour. A substrate solution containing cerium chloride was used to generate an electron dense reaction product.Sections from both procedures were postfixed in 1% OsO4 in 0.1 M phosphate buffer, rinsed and dehydrated. These were then flat embedded in EMbed 812 between two microscope slides coated with Liquid Release (both from Electron Microscopy Sciences).Polymerized sections were adhered to resin blocks using super glue, cut at 70-90 nm, stained with uranyl acetate/lead citrate and observed in a Philips CM-10 electron microscope.


Author(s):  
S. A. Livesey ◽  
A. A. del Campo ◽  
E. S. Griffey ◽  
D. Ohlmer ◽  
T. Schifani ◽  
...  

The aim of this study is to compare methods of sample preparation for elemental analysis. The model system which is used is the human erythrocyte. Energy dispersive spectroscopic analysis has been previously reported for cryofixed and cryosectioned erythrocytes. Such work represents the reference point for this study. The use of plastic embedded samples for elemental analysis has also been documented. The work which is presented here is based on human erythrocytes which have been either chemically fixed and embedded or cryofixed and subsequently processed by a variety of techniques which culminated in plastic embedded samples.Heparinized and washed erythrocytes were prepared by the following methods for this study :(1). Chemical fixation in 4% paraformaldehyde/0.25% glutaraldehyde/0.2 M sucrose in 0.1 M Na cacodylate, pH 7.3 for 30 min, followed by ethanol dehydration, infiltration and embedding in Lowicryl K4M at -20° C.


1968 ◽  
Vol 20 (03/04) ◽  
pp. 588-595 ◽  
Author(s):  
E. B Goodsell ◽  
R. A Krause ◽  
E. T Kimura

SummaryUbiquin (oligo-3-(N-methylmorpholinium)-l,2-propylene oxide chloride) is a stable, water soluble, active heparin antagonist producing prompt neutralization when administered in a 1:1 ratio to rats and dogs. Initial studies indicate that it is devoid of any effect on coagulation per se; nor are there any obvious side effects manifested during the process of neutralization. The acute toxicity is less than that of other compounds in use: toluidine blue, protamine and hexadimethrine.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


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