A Simple Method of Measuring Breath Hydrogen in Carbohydrate Malabsorption by End-Expiratory Sampling

1976 ◽  
Vol 50 (3) ◽  
pp. 237-240 ◽  
Author(s):  
G. Metz ◽  
M. A. Gassull ◽  
A. R. Leeds ◽  
L. M. Blendis ◽  
D. J. A. Jenkins
Keyword(s):  
Gas Chromatography ◽  
Hydrogen Production ◽  
Hydrogen Concentration ◽  
Coefficient Of Variation ◽  
Breath Hydrogen ◽  
Simple Method ◽  
Alveolar Air ◽  
Carbohydrate Malabsorption

1. A simple method is described for measuring the hydrogen concentration in alveolar air by end-expiratory sampling, by using a modified Haldane—Priestley tube and gas chromatography. Hydrogen was generated in vivo by ingestion of the non-absorbable sugar lactulose. 2. Alveolar hydrogen concentration showed a highly significant correlation with hydrogen production measured either by a rebreathing technique or by a total collection procedure. 3. The coefficient of variation of the end-expiratory method, assessed by comparing sixty-one paired results, was 11·6%. The coefficient of variation in ten measurements in one subject at 1 min intervals was 17·6%.

A Rapid and Simple Method for the Quantification in Human Plasma of Tricyclic Antidepressant Drugs Taken in Overdose

1979 ◽  
Vol 16 (1-6) ◽  
pp. 47-50 ◽  
Author(s):  
William D. Mitchell ◽  
Sarah F. Webb ◽  
George R. A. Padmore
Keyword(s):  
Gas Chromatography ◽  
Human Plasma ◽  
Coefficient Of Variation ◽  
Plasma Concentrations ◽  
Extraction Procedure ◽  
Antidepressant Drugs ◽  
Tricyclic Antidepressant ◽  
Simple Method ◽  
Coefficients Of Variation ◽  
Simple Extraction

A rapid and simple extraction procedure followed by gas chromatography using a nitrogen detector is described for the analysis of amitriptyline, nortriptyline, imipramine, and desipramine in 100 μl plasma. No derivitisation of the drugs is required. Recoveries ranged from 93·7 to 104·6%. Within-batch precision and day-to-day variation showed coefficients of variation of less than 10% with the exception of desipramine, for which the day-to-day coefficient of variation was 15·2%. The method was developed to measure plasma concentrations in patients who had taken non-fatal and fatal overdoses of the drugs.

The Filter Loop Technique as a Method of Measuring Platelet Aggregation in the Flowing Blood of the Rat; the Inhibitory Activity of 5-oxo-l-cyclopentene-l-heptanoic Acid (AY-16,804) on Platelet Aggregation

1973 ◽  
Vol 30 (01) ◽  
pp. 138-147 ◽  
Author(s):  
Christopher R. Muirhead
Keyword(s):  
Platelet Aggregation ◽  
Prostaglandin E1 ◽  
Suitable Model ◽  
Heptanoic Acid ◽  
Simple Method ◽  
Loop Technique ◽  
Flowing Blood ◽  
Filter Loop

SummaryThe filter loop technique which measures platelet aggregation in vivo in the flowing-blood of the rat was compared to the optical density technique of Born which is carried out in vitro with platelet rich plasma. Using these two experimental models the effect on platelet aggregation of three known inhibitors sulfinpyrazone, dipyridamole and prostaglandin E1, and a novel compound 5-oxo-l-cyclopentene-l-heptanoic acid (AY-16, 804) was determined.The effects on platelet aggregation of the known inhibitors were consistent with information in the literature. Prostaglandin E1 was the most potent inhibitor in both techniques; sulfinpyrazone inhibited aggregation in both models but was less potent than prostaglandin E1. AY-16, 804 exhibited activity in vitro and in vivo similar to that of sulfinpyrazone. Dipyridamole did not inhibit platelet aggregation in vivo and did not inhibit aggregation in vitro in concentrations at which it remained soluble.The filter loop technique is a suitable model for measuring platelet aggregation in the flowing blood of the rat. It is a relatively simple method of determining aggregation and easily adapted to other species.

Urinary metabolites of thromboxane and prostacyclin in diabetes mellitus

1988 ◽  
Vol 118 (2) ◽  
pp. 301-305 ◽  
Author(s):  
K. Gréen ◽  
O. Vesterqvist ◽  
V. Grill
Keyword(s):  
Diabetes Mellitus ◽  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Insulin Treatment ◽  
Artificial Pancreas ◽  
Urinary Metabolites ◽  
Gas Chromatography Mass Spectrometry ◽  
Diabetic State ◽  
In Vivo Synthesis

Abstract. The in vivo synthesis of thromboxane A2 and prostacyclin was estimated in 23 diabetics through measurements of the major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α utilizing gas chromatography-mass spectrometry. Mean excretion was similar to that in non-diabetic subjects. The possible influence of hyperglycemia on the excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α was evaluated in three ways: by measuring excretion before and during an acute 9-h normalization of hyperglycemia through an artificial pancreas (Biostator) as well as by comparing excretion before and 7–12 days or 40–180 days after the initiation of insulin treatment. Despite significant reducing effects on hyperglycemia or on levels of hemoglobin A1c, no effects on the excretion of the thromboxane and prostacyclin metabolites could be found. Abnormal formation of thromboxane or prostacyclin is not a generalized feature of the diabetic state.

Hydrogen production from cellulose catalyzed by an iridium complex in ionic liquid under mild conditions

2021 ◽  
Author(s):  
Genki Toyooka ◽  
Toshiki Tanaka ◽  
Kenji Kitayama ◽  
Naoko Kobayashi ◽  
Takashi Watanabe ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Production ◽  
Iridium Complex ◽  
Simple Method ◽  
Mild Conditions ◽  
Iridium Catalyst

A new and simple method for hydrogen production from cellulose using an iridium catalyst and an ionic liquid under mild conditions was developed.

scholarly journals Cemp1-p3 Peptide Promotes the Transformation of Octacalcium Phosphate into Hydroxyapatite Crystals

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1131
Author(s):  
Maricela Santana ◽  
Gonzalo Montoya ◽  
Raúl Herrera ◽  
Lía Hoz ◽  
Enrique Romo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Octacalcium Phosphate ◽  
Sequence Motifs ◽  
Simple Method ◽  
Transmission Electron ◽  
Precursor Phase ◽  
Mineralized Tissues ◽  
Potent Growth

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.

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