THE EFFECTS OF VARIOUS GOITROGENS ON THE DETERMINATION OF THE RELATIVE POTENCY OF THYROID BY THE GOITRE PREVENTION ASSAY

1964 ◽  
Vol 45 (3) ◽  
pp. 370-380 ◽  
Author(s):  
G. Stuart Wiberg ◽  
John R. Carter ◽  
Norman R. Stephenson
Keyword(s):  
Thyroid Hormones ◽  
Biological Activities ◽  
Iodine Content ◽  
The Other ◽  
Relative Potency ◽  
Total Iodine ◽  
Relative Potencies ◽  
Peripheral Metabolism ◽  
House Standard

ABSTRACT It is well known that thiouracil and its derivatives not only block the synthesis of thyroid hormones but also alter the peripheral metabolism of thyroxine and triiodothyronine. Other goitrogens such as thiourea, thiocyanate and perchlorate do not have this extra-thyroidal effect. Hence the measurement of endogenous thyroid function namely »thyroxine secretion rate« as determined by the goitre-prevention response is affected by thiouracil but not presumably by the other goitrogens. The purpose of the present study was to see what effect different goitrogens had on the estimation of the relative potency of thyroid powder by the goitre prevention assay. The biological activities of pork and beef thyroid samples relative to a house standard were determined in a series of bioassays which used various goitrogens. Assays employing either thiouracil, thiourea, aminotriazole or perchlorate led to statistically equivalent potency estimates and indicated that the pork thyroid was significantly more active than the beef thyroid on the basis of the total iodine content. However, the slope of the log dose-response lines were significantly affected by the different goitrogens. When the relative potencies of pork and beef thyroid were computed on the basis of the triiodothyronine content, the three preparations had equivalent activity for each of the goitrogens. Thiocyanate proved to be toxic at the dose level employed and a valid assay was not possible.

HUMAN URINARY GONADOTROPHINS ASSAYED BY DIFFERENT RESPONSES IN THE SAME ANIMAL

1960 ◽  
Vol XXXIV (III) ◽  
pp. 375-389 ◽  
Author(s):  
P. S. Brown
Keyword(s):  
Postmenopausal Women ◽  
Ovarian Response ◽  
The Other ◽  
Relative Potency ◽  
Vaginal Opening ◽  
Serial Sections ◽  
Immature Female ◽  
Female Mice ◽  
Marked Disparity ◽  
Relative Potencies

ABSTRACT Selected human urinary gonadotrophins were assayed against one another using various measures of response in the same immature female mice. Intact or hypophysectomized animals were used and in some experiments the results of hypophysectomy were checked in complete serial sections. Extracts from the urine of two subjects with Turner's syndrome were compared. In intact mice, the relative potency judged by the ovarian response differed from that shown by the uterine response and the 95 % fiducial limits of the two estimates did not overlap. When the mice were hypophysectomized, one extract became much less potent while the other did not. Similar differences were shown in the response of intact mice to urinary extracts from two subjects with Klinefelter's syndrome. There was a marked disparity between the relative potencies shown by the uterine response and by the incidence of vaginal opening. Similar differences were not shown between the responses to different extracts from the urine of normal postmenopausal women, but these extracts were known to differ little in quality. The results are interpreted in terms of qualitative differences between human urinary gonadotrophins.

scholarly journals Trace element content in market eggs in Bohemia

2012 ◽  
Vol 60 (6) ◽  
pp. 75-80 ◽  
Author(s):  
Hana Dušová ◽  
Jan Trávníček ◽  
Zdeněk Peksa ◽  
Daniel Falta ◽  
Václav Pálka
Keyword(s):  
Czech Republic ◽  
Spectrophotometric Method ◽  
Trace Element Content ◽  
Iodine Content ◽  
Egg Yolk ◽  
The Other ◽  
Average Content ◽  
Egg Yolks ◽  
Copper Zinc

The aim of this study was to analytically determine the content of iodine, copper, zinc and manganese in the yolk of consumer eggs in Bohemia in 2007 and 2008. Investigated eggs originated from six so called intensive farms with large flocks (118 eggs) and twelve backyard farms or small-flock establishments (136 eggs) from three administrative regions in Czech Republic. Eggs from intensive farms were obtained directly from the establishments, while eggs from backyard farms were purchased from private farmers. Spectrophotometric Sandell-Kolthoff method was used for determination of iodine content in egg yolk, while Cu, Zn and Mn levels were determined by the flame absorption spectrophotometric method (AAS). The average content in fresh egg yolk from intensive farms was determined to 0.9 ± 0.2 for iodine, 8.4 ± 2.1 of copper, 29.8 ± 6.9 of zinc and 1.2 ± 0.3 of manganese, all in mg·kg−1, as compared to yolk content from backyard farms with 0.4 ± 0.04 mg·kg−1 of iodine, 10.8 ± 2.9 of copper, 32.5 ± 6.9 of zinc and 1.5 ± 0.3 of manganese. Average content of copper, zinc and manganese was lower in egg yolks from intensive farms (P < 0.01) as compared to the egg yolks from backyard farms, while iodine content on the other hand was lower in eggs from backyard farms (P < 0.01).

IODOAMINO ACID COMPOSITION OF POORLY IODINATED HUMAN THYROGLOBULIN FRACTIONATED BY ISOPYCNIC CENTRIFUGATION

1978 ◽  
Vol 87 (2) ◽  
pp. 320-329 ◽  
Author(s):  
A. Vignal ◽  
B. M. Nataf ◽  
M. Tubiana
Keyword(s):  
Thyroid Hormones ◽  
Acid Composition ◽  
Sucrose Gradient ◽  
Gradient Centrifugation ◽  
Thyroid Tissue ◽  
Iodine Content ◽  
Human Thyroid ◽  
Total Iodine ◽  
Sucrose Gradient Centrifugation ◽  
Isopycnic Centrifugation

ABSTRACT The distribution of iodotyrosines and iodothyronines has been studied in poorly iodinated 19 S thyroglobulins isolated by sucrose gradient centrifugation from five human thyroid tissue. The 19 S thyroglobulins have been fractionated by isopycnic centrifugation in 34.5 % rubidium chloride gradient. The distribution of iodoamino acids depends on the total iodine content of each fraction. The variations in MIT1) and DIT residues with increasing levels of iodination are not identical, the elevation of DIT residues being higher than that of MIT. The number of T4 residues increases quite rapidly after 5 atoms of iodine while T3 increases slightly and slowly. It is shown here that, even after fractionation of poorly iodinated thyroglobulin, the synthesis of thyroid hormones is observed at a level of iodine content as low as 1.4 and 1.8 atoms per molecule of thyroglobulin. This shows that the thyroglobulin fractions obtained by isopycnic centrifugation are still heterogeneous, although less than the initial non-fractionated thyroglobulin. In order to explain our data, it must be admitted that a large proportion of thyroglobulin molecules are not iodinated.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

Procedures for the Quantitative Determination of Autoprothrombin C

1962 ◽  
Vol 08 (03) ◽  
pp. 434-441 ◽  
Author(s):  
Edmond R Cole ◽  
Ewa Marciniak ◽  
Walter H Seegers
Keyword(s):  
Quantitative Determination ◽  
Plasma Sample ◽  
Quantitative Measure ◽  
The Other ◽  
Clotting Time ◽  
Bovine Plasma ◽  
Autoprothrombin C

SummaryTwo quantitative procedures for autoprothrombin C are described. In one of these purified prothrombin is used as a substrate, and the activity of autoprothrombin C can be measured even if thrombin is in the preparation. In this procedure a reaction mixture is used wherein the thrombin titer which develops in 20 minutes is proportional to the autoprothrombin C in the reaction mixture. A unit is defined as the amount which will generate 70 units of thrombin in the standardized reaction mixture. In the other method thrombin interferes with the result, because a standard bovine plasma sample is recalcified and the clotting time is noted. Autoprothrombin C shortens the clotting time, and the extent of this is a quantitative measure of autoprothrombin C activity.

Determination of Factor XIII Activity and of Factor XIII Inhibitors Using an Ammonium-Sensitive Electrode

1983 ◽  
Vol 50 (02) ◽  
pp. 563-566 ◽  
Author(s):  
P Hellstern ◽  
K Schilz ◽  
G von Blohn ◽  
E Wenzel
Keyword(s):  
Factor Xiii ◽  
Normal Subjects ◽  
The Other ◽  
Activity Measurement ◽  
Factor Xiii Deficiency ◽  
Assay Procedure ◽  
Stabilization Factor ◽  
Release Method ◽  
Sensitive Electrode

SummaryAn assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 ± 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the “ammonium-release-method”, Bohn’s method, and the immunological assay (r1 = 0.65; r2= 0.70; p<0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.

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