scholarly journals DETERMINATION OF HISTIDINE DECARBOXYLASE IN MICROGRAM SAMPLES OF TISSUE, PROPERTIES AND QUANTITATIVE HISTOCHEMISTRY OF THE ENZYME AND HISTAMINE IN THE RAT STOMACH

1967 ◽  
Vol 15 (6) ◽  
pp. 347-352 ◽  
Author(s):  
YOUNG S. KIM ◽  
DAVID GLICK
Keyword(s):  
Enzyme Activity ◽  
Histidine Decarboxylase ◽  
Preliminary Investigation ◽  
The Body ◽  
Rat Stomach ◽  
Michaelis Constant ◽  
Cell Region ◽  
Tissue Properties ◽  
Effects Of Ph

Properties of histidine decarboxylase of rat stomach were studied, including measurements of the Michaelis constant and effects of pH. Optimal conditions for determination of the enzyme were established. A method for this determination on microgram samples of tissue, e.g., microtome sections, that depends on fluorometric analysis of nanogram amounts of histamine, was elaborated and applied to a preliminary investigation of the quantitative histologic distribution of histidine decarboxylase in the body of the glandular stomach of the rat. A parallel study of the quantitative distribution of histamine was also made, and both it and the enzyme activity were predominantly concentrated in the chief cell region. From analysis of gross homogenates, the body of the stomach was found to have greater concentrations of histamine and enzyme activity than the antrum. The findings obtained were considered in relation to distribution of mast cells and acid secretion.

scholarly journals QUANTITATIVE HISTOLOGIC DISTRIBUTION OF ADENOSINE-3',5'-MONOPHOSPHATE IN THE RAT STOMACH IMPROVED PROCEDURE FOR THE LUMINESCENCE ASSAY

1974 ◽  
Vol 22 (6) ◽  
pp. 395-400 ◽  
Author(s):  
DAVID GLICK ◽  
YOSHINAO KATSUMATA ◽  
DOROTHY VON REDLICH
Keyword(s):  
Histidine Decarboxylase ◽  
Muscle Layer ◽  
Chief Cell ◽  
The Body ◽  
Glandular Stomach ◽  
Cell Region ◽  
Time Saving ◽  
Protein Nitrogen ◽  
Wet Weight

Procedural improvements of the luminescence method for determination of adenosine-3',5'-monophosphate (cAMP) in submilligram samples, e.g., fresh-frozen microtome sections of tissue or l0-µl volumes of homogenate, were developed for technical simplification, time-saving and increased analytical precision and then applied to determination of the quantitative histologic distribution of cAMP in the body of the glandular stomach of the fed and fasted rat. In fasted rats, a sharp peak in cAMP concentration (0.12 pmole/µg protein-nitrogen, approximately ≈ 3.3 pmoles/mg wet weight) was observed in the parietal mucous neck cell zone and the values fell off rapidly to about one-half peak value in the chief cell region and remained in this range into the muscle layer. When fed, additional second and third peaks appeared in the chief cell and muscle zones, each about l0% less than the first peak. The histologic position and the height of the first peak did not change significantly from that in the fasted state. For comparison, homogenates of glandular stomach of fed rats were found to have cAMP values in the range, 1.9-2.4 pmoles/mg wet weight. The findings are discussed in relation to quantitative distribution and function of histamine and histidine decarboxylase and to acid secretion.

New fluorogenic substrates for the determination of post-proline endopeptidase activity

1990 ◽  
Vol 55 (4) ◽  
pp. 1112-1118 ◽  
Author(s):  
Chryssa Tzougraki ◽  
George Kokotos ◽  
Hana P. Mašková ◽  
Eva Anzenbacherová ◽  
Tomislav Barth
Keyword(s):  
Enzyme Activity ◽  
Organic Solvent ◽  
Fluorogenic Substrate ◽  
Michaelis Constant ◽  
Fluorogenic Substrates ◽  
Endopeptidase Activity ◽  
Optimum Ph ◽  
Adverse Influence

A new fluorogenic substrate for determination of the activity of post-proline endopeptidase (EC 3.4.21.26), Z-Cys(Bzl)-Pro-NH-Meq has been synthesized. Affinity of this substrate to the enzyme was significantly higher than that of the hitherto employed substrates. The Michaelis constant of the post-proline endopeptidase for Z-Cys(Bzl)-Pro-NH-Meq was at the optimum pH (7.0) 1.05 10-6 mol l-1. The concentration of dimethylsulfoxide used for the solubilization of Z-Cys(Bzl)-Pro-NH-Meq (<0.4%) was outside the limits of adverse influence of the organic solvent on the enzyme activity. The fluorogenic substrate Z-Gly-Pro-NH-Meq was also synthesized for comparison (Km = 10.35 10-6 mol l-1 at pH 7.0).

Determination of acetylcholinesterase and butyrylcholinesterase activity without dilution of biological samples

2015 ◽  
Vol 69 (8) ◽  
Author(s):  
Miroslav Pohanka
Keyword(s):  
Enzyme Activity ◽  
Liver Function ◽  
Biological Samples ◽  
The Body ◽  
Reversible Inhibitors ◽  
Butyrylcholinesterase Activity ◽  
Sample Dilution

AbstractTwo cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), are known. The enzymes are important in the body and alteration of their activity has significant use in the diagnosis of poisoning, liver function, etc. Currently available methods for the determination of cholinesterases have some major drawbacks including various interferences and the inability to be used for decreasing the enzyme activity in the presence of reversible inhibitors due to sample dilution; hence, a method for dilution free assay of cholinesterases is desired. Here, microplates were modified with indoxylacetate (100 μL of 10 mmol L

PRE-CONCENTRATION AND DETERMINATION OF PB(II) FROM WATER SAMPLES USING MODIFIED MULTIWALLED CARBON NANOTUBES

2015 ◽  
Vol 76 (13) ◽  
Author(s):  
Neda Pourmand ◽  
Mohd Marsin Sanagi ◽  
Wan Aini Wan Ibrahim ◽  
Ahmed Salisu
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Water Samples ◽  
Metal Ion ◽  
Solid Phase ◽  
The Body ◽  
Lead Ion ◽  
Multiwalled Carbon ◽  
Effects Of Ph

Pb(II) is a topically poisonous metal ion that can affect almost every organ and system in the body; it can accumulate in the body and cause kidney malfunctioning, hematological and brain damages. Recently, carbon nanotubes (CNTs), the nano-structured material, are applied for pre-concentration of heavy metal ions. This study investigates the pre-concentration of lead ion using oxidized multiwalled carbon nanotubes (MWCNT-COOH) via solid phase extraction method. MWCNT-COOH was prepared using as-synthesized MWCNT and the products were characterized by FTIR, FESEM, TEM and TGA. Various factors influencing the separation and pre-concentration were investigated namely the effects of pH (2-7) and the elution conditions (type, concentration and volume of eluent). The best extraction conditions were sample of pH 5 and 5 mL of 1M HNO3 as eluent. The developed method was successfully applied to the determination of trace quantities of Pb(II) in water samples with good analyte recoveries (90-102.5%). 

Histidine decarboxylase in rat stomach ECL cells: relationship between enzyme activity and different molecular forms

1999 ◽  
Vol 81 (1-3) ◽  
pp. 41-48 ◽  
Author(s):  
Christine Dartsch ◽  
Duan Chen ◽  
Rolf Håkanson ◽  
Lo Persson
Keyword(s):  
Enzyme Activity ◽  
Histidine Decarboxylase ◽  
Molecular Forms ◽  
Rat Stomach ◽  
Ecl Cells

THE TAC METHOD OF TRYPTIC ENZYME ACTIVITY DETERMINATION

1960 ◽  
Vol 38 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Edward Ronwin
Keyword(s):  
Enzyme Activity ◽  
Quantitative Method ◽  
Null Point ◽  
Ion Concentration ◽  
Cupric Ion ◽  
Buffer Solutions ◽  
Enzyme Substrate ◽  
Titration Procedure ◽  
Effects Of Ph

A new, practical, and quantitative method for the determination of tryptic enzyme activity is reported. The method is based on measurements of the U.V. absorption of the complex formed between cupric ion and Nα-p-toluenesulphonyl-L-arginine, the latter being the product of the reaction between the tryptic enzymes (thrombin, trypsin, plasmin) and the corresponding methyl ester. Comparisons with the null point titration procedure demonstrate the new method's superiority when dealing with enzyme–substrate reactions in concentrated buffer solutions. Under certain conditions, it could also be superior in dilute buffer situations. The effects of pH and cupric ion concentration on complex formation are discussed along with other characteristics of the U.V. absorption curves of the complex.

THE TAC METHOD OF TRYPTIC ENZYME ACTIVITY DETERMINATION

1960 ◽  
Vol 38 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Edward Ronwin
Keyword(s):  
Enzyme Activity ◽  
Quantitative Method ◽  
Null Point ◽  
Ion Concentration ◽  
Cupric Ion ◽  
Buffer Solutions ◽  
Enzyme Substrate ◽  
Titration Procedure ◽  
Effects Of Ph

A new, practical, and quantitative method for the determination of tryptic enzyme activity is reported. The method is based on measurements of the U.V. absorption of the complex formed between cupric ion and Nα-p-toluenesulphonyl-L-arginine, the latter being the product of the reaction between the tryptic enzymes (thrombin, trypsin, plasmin) and the corresponding methyl ester. Comparisons with the null point titration procedure demonstrate the new method's superiority when dealing with enzyme–substrate reactions in concentrated buffer solutions. Under certain conditions, it could also be superior in dilute buffer situations. The effects of pH and cupric ion concentration on complex formation are discussed along with other characteristics of the U.V. absorption curves of the complex.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Determination of Lead Content in Red Colored Lipsticks from Mandalay Market by Flame Atomic Absorption Spectrophotometer

2018 ◽  
Vol 30 (3) ◽  
pp. 167-173
Keyword(s):  
Sampling Procedure ◽  
The Body ◽  
Lead Content ◽  
Social Psychological ◽  
Allowable Limit ◽  
Flame Atomic Absorption ◽  
Therapeutic Benefits ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Exposure Levels

Red colored lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because some lipsticks contain a considerable amount of heavy metal especially lead. Lead is being used in lipstick mainly for the pigments required to obtain needed colors. Lead accumulates in the body over time and lead-containing lipstick applied several times a day, every day, combined with lead in water and other sources, could add up to significant exposure levels. Therefore, this study was aimed to determine lead content in red colored lipsticks from market. This study was laboratorybased, analytical study by using 25 lipstick samples. Red colored lipsticks were bought from Mandalay Market by random sampling procedure and they were completely coded to avoid the bias. Then, lead content in coded samples was determined by Flame AAS according to International Conference on Harmonization (ICH) guideline. Lead contents of 88% of the lipsticks samples were more than specified limit (20 ppm) of Food and Drug Administration, United States. All of them, lead content was highest in counterfeit lipsticks group. Among the tested lipstick samples, lipstick with lowest lead content was LE-RL 01 (15.74 ppm) and the lipstick with highest lead content was CF-RL 01(60.09 ppm). In conclusion, lead contents of red colored lipsticks (22 out of 25) from market samples were higher than allowable limit (20 ppm).

Fast Method for the Determination of Residual Solvents in Radiopharmaceutical Products

2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric
Keyword(s):  
Gas Chromatography ◽  
Control Method ◽  
Limit Of Detection ◽  
The Body ◽  
Biologically Active ◽  
Injection Technique ◽  
Fast Method ◽  
Residual Solvent ◽  
Residual Solvents

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.

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