ON THE ASSAY OF CORTICOTROPHIN: COMPARISON OF THE PLASMA CORTICOSTEROID AND ADRENAL ASCORBIC ACID RESPONSE

1961 ◽  
Vol 38 (2) ◽  
pp. 220-235 ◽  
Author(s):  
Claus Rerup ◽  
Pavo Hedner
Keyword(s):  
Ascorbic Acid ◽  
Critical Evaluation ◽  
Correlation Coefficients ◽  
Assay Method ◽  
Practical Reasons ◽  
Hypophysectomized Rats ◽  
Subsequent Calculation ◽  
Points Of View ◽  
The Individual ◽  
Free Plasma

ABSTRACT A new subcutaneous assay method for corticotrophin using the level of free plasma corticosteroids in hypophysectomized rats as the response is described. A critical evaluation of the results compared with those of the adrenal ascorbic acid depletion assay method is given. It was found, that the plasma corticoid method has about the same precision (λ = 0.25) as the adrenal ascorbic acid depletion method, but that the former is about five times more sensitive. It is possible to apply a cross-over design to the plasma corticoid method, which increases the assay efficiency to about 250 per cent of non-cross-over assays. From simultaneous measurements of adrenal ascorbic acid concentration and plasma corticoid levels and subsequent calculation of their correlation coefficients it appeared, that the mechanism of ascorbic acid depletion is quantitatively not closely linked to that of adrenal corticoid output in the individual rat. On the basis of its advantages from the theoretical points of view (higher specificity) and for practical reasons, it is proposed to replace the adrenal ascorbic acid depletion method by the plasma corticoid method for pharmacopeial corticotrophin assays.

PLASMA CORTICOSTEROID LEVELS AND ADRENAL ASCORBIC ACID AFTER INTRAVENOUS CORTICOTROPHIN INJECTIONS AND »STRESSFUL« STIMULI IN THE RAT

1962 ◽  
Vol 39 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Pavo Hedner ◽  
Claus Rerup
Keyword(s):  
Ascorbic Acid ◽  
Abdominal Surgery ◽  
Response Curve ◽  
Significant Rise ◽  
Blocking Effect ◽  
High Dose ◽  
Ascorbic Acid Concentration ◽  
Unilateral Adrenalectomy ◽  
Subcutaneous Injections ◽  
Hypophysectomized Rats

ABSTRACT Measurements of plasma corticosteroid levels and adrenal ascorbic acid concentration in steroid blocked and hypophysectomized rats were performed. It was found that prednisolone and dexamethasone were effective in blocking endogenous corticotrophin release within 3–4 hours after subcutaneous injection. These agents also prevented completely the normally occurring rise in plasma corticoid levels after exposure of the rats to ether. Abdominal surgery (unilateral adrenalectomy) resulted in a slight but significant rise in plasma corticoid levels in spite of dexamethasone blockade. The values of adrenal ascorbic acid were not affected significantly. The blocking effect of two daily subcutaneous injections of a high dose of dexamethasone persisted for about one week after the last injection. The sensitivity of the plasma corticoid response was essentially the same in hypophysectomized and dexamethasone blocked rats. The lower part of the log dose response curve was found to be clearly non-linear in the plasma corticoid method following intravenous corticotrophin injection. As a consequence the dose level in quantitative assays of intravenously injected corticotrophin are, in our hands, of the same order as in the adrenal ascorbic acid depletion method.

High dose ascorbic acid treatment in COVID-19 patients raised some problems in clinical chemistry testing

2020 ◽  
Vol 45 (5) ◽  
pp. 491-498
Author(s):  
Fatih Yesildal ◽  
Ferruh Kemal Isman
Keyword(s):  
Ascorbic Acid ◽  
Ldl Cholesterol ◽  
Clinical Chemistry ◽  
Assay Method ◽  
High Dose ◽  
Serum Samples ◽  
Choice Of Treatment ◽  
High Concentrations ◽  
Clinical Chemistry Tests ◽  
Abbott Architect

AbstractObjectiveCOVID-19 pandemia still continues to threaten the whole world. High dose ascorbic acid (AA) infusion is a choice of treatment and its efficiency is still being investigated. AA interferes with many clinical chemistry tests. However, data about the interference of high concentrations of AA is not sufficient. In this study, we aimed to investigate the interference of AA at high concentrations on commonly used chemistry assays.Materials and MethodsSerum samples at AA concentrations of 200, 150, 100, 75, 50, 25, 10, 5, 2 and 0 mg/dL were prepared by using the stock solution of 15000 mg/dL AA. Each sample was analyzed by using the most common 30 chemistry tests (Abbott Architect C8000, Illinois, USA) and a POCT glucometer (STANDARD GlucoNavii, Gyeonggi-do, Republic of Korea).ResultsCreatinine, sodium and glucose (POCT) tests were found to be positively interfered by increasing AA concentrations; while direct bilirubin, lipase, UIBC, triglyceride, total cholesterol, HDL/LDL cholesterol tests were negatively interfered. Absolute interference (%) increased as the AA concentration increased.ConclusionThis is the largest and first study to investigate the interference of high dose AA, which is used in severe COVID-19 patients nowadays. Manufacturers and clinicians should be aware of the possibility of aberrant results due to high dose AA infusion. Clinicians should not forget to consult a laboratory specialist, since he is the only person to monitor the reactions in all assays, and know the technical subjects like interferences, assay method specifications. This issue is very important for correct decision-making and interpretation of the data-mining studies accurately and efficiently.

scholarly journals Insights to enhance the examination of tool marks in human cartilage

2021 ◽  
Author(s):  
Matthias Weber ◽  
Anja Niehoff ◽  
Markus A. Rothschild
Keyword(s):  
Light Microscope ◽  
Cross Correlation ◽  
Costal Cartilage ◽  
Correlation Coefficients ◽  
Human Cartilage ◽  
Cut Marks ◽  
Tool Marks ◽  
The Cross ◽  
Cleaning Methods ◽  
The Individual

AbstractThis work deals with the examination of tool marks in human cartilage. We compared the effectiveness of several cleaning methods on cut marks in porcine cartilage. The method cleaning by multiple casts achieved the significantly highest scores (P = 0.02). Furthermore, we examined the grain-like elevations (dots) located on casts of cut cartilage. The results of this study suggest that the casting material forms these dots when penetrating cartilage cavities, which are areas where the strong collagen fibres leave space for the chondrocytes. We performed fixation experiments to avoid this, without success. In addition, 31 casting materials were compared regarding contrast under light-microscope and 3D tool marks scanner. Under the light-microscope, brown materials achieved significantly higher values than grey (P = 0.02) or black (P = 0.00) whereas under the 3D scanner, black materials reached higher contrast values than grey (P = 0.04) or brown (P = 0.047). To compare the accuracy and reproducibility of 6 test materials for cartilage, we used 10 knives to create cut marks that were subsequently scanned. During the alignment of the individual signals of each mark, the cross-correlation coefficients (Xmax) and lags (LXmax) were calculated. The signals of the marks in agarose were aligned with significantly fewer lags and achieved significantly higher cross-correlation coefficients compared to all tested materials (both P = 0.00). Moreover, we determined the cross-correlation coefficients (XC) for known-matches (KM) per material. Agarose achieved significantly higher values than AccuTrans®, Clear Ballistics™, and gelatine (all P = 0.00). The results of this work provide valuable insights for the forensic investigation of marks in human costal cartilage.

scholarly journals POS1391 MEASURING SUBCLINICAL INFLAMMATION IN HAND AND FOREFOOT IN PATIENTS WITH ARTHRALGIA USING 1.5T OR 3.0T MRI: DOES FIELD STRENGTH MATTER?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 978.1-978
Author(s):  
D. Krijbolder ◽  
M. Verstappen ◽  
F. Wouters ◽  
L. R. Lard ◽  
P. D. De Buck ◽  
...  
Keyword(s):  
Field Strength ◽  
Scientific Evidence ◽  
Correlation Coefficients ◽  
Daily Practice ◽  
Scientific Data ◽  
Imaging Features ◽  
Subclinical Inflammation ◽  
The Individual ◽  
3.0T Mri ◽  
Inflammation Score

Background:Magnetic resonance imaging (MRI) of small joints sensitively detects inflammation. MRI-detected subclinical inflammation, and tenosynovitis in particular, has been shown predictive for RA development in patients with arthralgia. These scientific data are mostly acquired on 1.0T-1.5T MRI scanners. However, 3.0T MRI is nowadays increasingly used in practice. Evidence on the comparability of these field strengths is scarce and it has never been studied in arthralgia where subclinical inflammation is subtle. Moreover, comparisons never included tenosynovitis, which is, of all imaging features, the strongest predictor for progression to RA.Objectives:To determine if there is a difference between 1.5T and 3.0T MRI in detecting subclinical inflammation in arthralgia patients.Methods:2968 locations (joints, bones or tendon sheaths) in hands and forefeet of 28 arthralgia patients were imaged on both 1.5T and 3.0T MRI. Two independent readers scored for erosions, osteitis, synovitis (according to RAMRIS) and tenosynovitis (as described by Haavaardsholm et al.). Scores were also summed as total inflammation (osteitis, synovitis and tenosynovitis) and total RAMRIS (erosions, osteitis, synovitis and tenosynovitis) scores. Interreader reliability (comparing both readers) and field strength agreement (comparing 1.5T and 3.0T) was assessed with interclass correlation coefficients (ICCs). Next, field strength agreement was assessed after dichotomization into presence or absence of inflammation. Analyses were performed on patient- and location-level.Results:ICCs between readers were excellent (>0.90). Comparing 1.5 and 3.0T revealed excellent ICCs of 0.90 (95% confidence interval 0.78-0.95) for the total inflammation score and 0.90 (0.78-0.95) for the total RAMRIS score. ICCs for individual inflammation features were: tenosynovitis: 0.87 (0.74-0.94), synovitis 0.65 (0.24-0.84) and osteitis 0.96 (0.91-0.98). The field strength agreement on dichotomized scores was 83% for the total inflammation score and 89% for the total RAMRIS score. Of the individual features, agreement for tenosynovitis was the highest (89%). Analyses on location- level showed similar results.Conclusion:Agreement of subclinical inflammation scores on 1.5T and 3.0T were good to excellent, in particular for tenosynovitis. This suggests that scientific evidence on predictive power of MRI in arthralgia patients, obtained on 1.5T, can be generalized to 3.0T when this field strength would be used for diagnostic purposes in daily practice.Disclosure of Interests:None declared

LEGAL STATUS OF THE SOLE EXECUTIVE BODY OF A LIMITED LIABILITY COMPANY

2021 ◽  
Author(s):  
Yulia Fanilevna Aitova ◽  
Keyword(s):  
General Theory ◽  
Legal Status ◽  
Limited Liability ◽  
Point Of View ◽  
Limited Liability Company ◽  
Points Of View ◽  
Theory Of Law ◽  
The Individual ◽  
Executive Body

The article analyzes the issue of determining the legal status of the individual management body of a limited liability company. The author begins his research with the concept of legal status existing in the general theory of law, and then proceeds to consider the issue from the point of view of philosophical categories. In addition, the work explores the diversity of points of view existing in the doctrine regarding the legal status of the individual management body of economic societies.

Evaluating the effect of climate variation on the cost efficiency of a crop permit policy in Southern Sweden

2013 ◽  
Vol 4 (2) ◽  
pp. 110-117
Author(s):  
Dennis Collentine ◽  
Holger Johnsson
Keyword(s):  
Cost Efficiency ◽  
Agricultural Sector ◽  
Policy Design ◽  
Correlation Coefficients ◽  
Nitrogen Loads ◽  
Weather Variation ◽  
The Baltic ◽  
The Individual ◽  
The Cost ◽  
The Impact

Current international agreements call for a significant reduction of nitrogen loads to the Baltic Sea. New measures to reduce nitrogen loads from the agricultural sector and an increased focus on cost efficiency will be needed to meet reduction targets. For policy design and evaluation it is important to understand the impact of weather on the efficiency of abatement measures. One new proposed policy is the use of crop permits based on weather normalized average leaching. This paper describes the use of the Spearman method to determine the efficiency of this policy with annual weather variation. The conclusion is that the values of the Spearman correlation coefficients in the study indicate that using average leaching for the individual crops on specific soil types for calculating crop permit requirements is an efficient policy. The Spearman method is demonstrated to be a simple useful tool for evaluating the impact of weather and is recommended for use in new studies.

Validation of tonometric measurement of gut intramural pH during endotoxemia and mesenteric occlusion in pigs

1990 ◽  
Vol 259 (4) ◽  
pp. G519-G523 ◽  
Author(s):  
J. B. Antonsson ◽  
C. C. Boyle ◽  
K. L. Kruithoff ◽  
H. L. Wang ◽  
E. Sacristan ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Group Iv ◽  
Low Flow ◽  
Total Occlusion ◽  
Group Iii ◽  
Group I ◽  
Invasive Method ◽  
Tissue Pco2 ◽  
Tissue Acidosis ◽  
The Individual

Tonometry is a minimally invasive method for estimating gastrointestinal intramural pH (pHi). Tissue pH is calculated by using the Henderson-Hasselbalch equation and measurements of arterial [HCO-3] and CO2 tension (PCO3) of saline contained in a Silastic balloon within the lumen of the gut. The validity of the method rests on two key assumptions: 1) PCO2 in saline in the tonometer balloon is similar to tissue PCO2 and 2) tissue and arterial [HCO-3] are similar. To validate this method, ileal pHi measured directly with a microelectrode was compared with pHi estimated tonometrically in four groups of anesthetized pigs. Group I (n = 4) were controls. In group II (n = 4), intestinal tissue acidosis was induced by total occlusion of the superior mesenteric artery (SMA). In group III (n = 5), acidosis was induced by partial occlusion of the SMA. In group IV (n = 4), tissue acidosis was induced by endotoxemia. Agreement was excellent between direct and tonometric measurements in groups I and IV and less good in groups II and III. Weighted mean correlation coefficients (rw) for the two measurement methods were 0.743 and 0.9447 in groups II and IV, respectively. Correlation coefficients for the individual animals in group III were more variable than the other groups and ranged from 0.547 to 0.990. The tonometric method for measuring GI pHi is invalid under conditions of zero flow and leads to error under conditions of low flow. However, the method is reliable in the setting of tissue acidosis induced by endotoxemia.

scholarly journals Advancements of the examination of tool marks in human cartilage

2021 ◽  
Author(s):  
Matthias Weber ◽  
Anja Niehoff ◽  
Markus A. Rothschild
Keyword(s):  
Light Microscope ◽  
Cross Correlation ◽  
Costal Cartilage ◽  
Correlation Coefficients ◽  
Human Cartilage ◽  
Cut Marks ◽  
Tool Marks ◽  
The Cross ◽  
Cleaning Methods ◽  
The Individual

Abstract This work deals with the examination of tool marks in human cartilage. We compared the effectiveness of several cleaning methods on cut marks in porcine cartilage. The method cleaning by multiple casts achieved the significantly highest scores (P = 0.02). Furthermore, we examined the grain-like elevations (dots) located on casts of cut cartilage. The results of this study suggest that the casting material forms these dots when penetrating cartilage cavities, which are areas where the strong collagen fibers leave space for the chondrocytes. We performed fixation experiments to avoid this, without success. In addition, 31 casting materials were compared regarding contrast under light-microscope and 3D tool marks scanner. Under the light-microscope, brown materials achieved significantly higher values than grey (P = 0.02) or black (P = 0.00) whereas under the 3D scanner, black materials reached higher contrast values than grey (P = 0.04) or brown (P = 0.047). To compare the accuracy and reproducibility of 6 test materials for cartilage, we used 10 knives to create cut marks that were subsequently scanned. During the alignment of the individual signals of each mark, the cross-correlation coefficients (Xmax) and lags (LXmax) were calculated. The signals of the marks in agarose were aligned with significantly fewer lags and achieved significantly higher cross-correlation coefficients compared to all tested materials (both P = 0.00). Moreover, we determined the cross-correlation coefficients (XC) for known-matches (KM) per material. Agarose achieved significantly higher values than AccuTrans®, Clear Ballistics™, and gelatine (all P = 0.00). The results of this work provide valuable insights for the forensic investigation of marks in human costal cartilage.

scholarly journals KINETIC MODEL OF THIOUREA DIOXIDE DECOMPOSITION IN AQUEOUS SOLUTIONS OF DIFFERENT ACIDITY

2018 ◽  
Vol 61 (12) ◽  
pp. 87-93
Author(s):  
Yuri V. Polenov ◽  
Gleb A. Shestakov ◽  
Elena V. Egorova
Keyword(s):  
Kinetic Model ◽  
Rate Constants ◽  
Silver Chloride ◽  
Mercury Electrode ◽  
Calculated Data ◽  
Correlation Coefficients ◽  
F Test ◽  
Thiourea Dioxide ◽  
Dropping Mercury Electrode ◽  
The Individual

A stoichiometric mechanism for full thiourea dioxide decomposition in aqueous solution under pH of 4.0 is proposed based on dependences of concentrations of thiourea dioxide and its decomposition products on the time and literature data. The concentration of thiourea dioxide was measured via iodometry, while the intermediates were quantified using the polarography. Polarography was carried out in glass two-electrode electrochemical cell by means of PU-1 polarograph in differential mode. Dropping mercury electrode was used as working one and silver chloride as a reference one. Rate constants for individual stages are obtained via mathematical modeling, presented a system of differential equations. Absolute errors of rate constants, correlation coefficients, and F-factors were also calculated. Verification of supposed kinetic model was conducted using the comparison between experimental and calculated concentrations, F-test and the calculated values of correlation coefficients of the individual stages of the process. Supposed kinetic model of decomposition consists of a number of consequent stages including various compounds such as sulfur monoxide, thiosulfuric, sulfuric, dithionic, hydrosulfuric acids as intermediates was used for previously obtained data for pH of 8.85. To test the universality of supposed model, we simulated kinetics of thiourea dioxide decomposition reaction at pH of 8.85. Experimental kinetic data were taken from literature. The initial approximations of the individual stages constants were taken from previous calculations. Analysis of calculated data: concentration values, F-test, correlation coefficients allowed to conclude about the applicability of proposed mechanism for the process of thiourea dioxide decomposition in a weakly alkaline medium.

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