THE HYPOCALCAEMIC AND HYPOPHOSPHATAEMIC EFFECT OF EXTRACTS FROM CHICKEN ULTIMOBRANCHIAL GLANDS

1969 ◽  
Vol 60 (4) ◽  
pp. 689-695 ◽  
Author(s):  
O. Helmer Sorensen ◽  
S. Pors Nielsen
Keyword(s):  
Thyroid Gland ◽  
Serum Calcium ◽  
Dose Response ◽  
Thyroid Tissue ◽  
Response Curves ◽  
Gland Extract ◽  
Ultimobranchial Glands ◽  
Thyroid Glands ◽  
Dose Response Curves ◽  
Ultimobranchial Gland

ABSTRACT Acid extracts of chicken ultimobranchial and thyroid glands were assayed in the rat for their effects on serum calcium and phosphate. The concentration of a hypocalcaemic factor in the ultimobranchial tissue was more than 100 times greater than that found in pig thyroid tissue. No hypocalcaemic activity was found in the chicken thyroid gland. An extract of the ultimobranchial glands was found to have a significant hypophosphataemic effect in the rat. This fact combined with the parallelism of the log dose-response curves found for the ultimobranchial gland extract and a calcitonin standard, suggests that hypocalcaemic factor is similar to mammalian calcitonin.

CALCITONIN-LIKE ACTIVITY IN THE CIRCULATION OF OSTEOPETROTIC GREY-LETHAL MICE

1972 ◽  
Vol 53 (1) ◽  
pp. 139-150 ◽  
Author(s):  
HELEN M. MURPHY
Keyword(s):  
Thyroid Gland ◽  
Acid Hydrolysis ◽  
Silica Gel ◽  
Dose Response ◽  
Response Curves ◽  
Mouse Plasma ◽  
Small Polypeptide ◽  
Dose Response Curves ◽  
Lines Of Evidence ◽  
Mouse Thyroid

SUMMARY Hypocalcaemia resulted from the injection of grey-lethal mouse plasma into assay mice. On bioassay, parallelism in dose—response curves was established between this factor, MRC research standard calcitonin and acid extracts from the grey-lethal mouse thyroid gland. Other lines of evidence, i.e. stability at neutral and acid pH's after ultracentrifugation for long periods, after adsorption on to silica gel and the results of enzymic and acid hydrolysis, suggest that the hypocalcaemic factor is a small polypeptide. Since a hypersecretion of calcitonin could account for most of the findings in the osteopetrosis of the grey-lethal mouse it is tentatively proposed that the hypocalcaemic factor is this hormone.

Dose-response Curves in the Fibrin Plate Assay Fibrinolytic Activity of Proteases

1974 ◽  
Vol 32 (02/03) ◽  
pp. 356-365 ◽  
Author(s):  
F Haverkate ◽  
D. W Traas
Keyword(s):  
Dose Response ◽  
Fibrinolytic Activity ◽  
Enzyme Concentration ◽  
Response Curves ◽  
Agar Gel ◽  
Porcine Tissue ◽  
Plate Assay ◽  
Fibrin Plate ◽  
Different Types ◽  
Dose Response Curves

SummaryIn the fibrin plate assay different types of relationships between the dose of applied proteolytic enzyme and the response have been previously reported. This study was undertaken to determine whether a generally valid relationship might exist.Trypsin, chymotrypsin, papain, the plasminogen activator urokinase and all of the microbial proteases investigated, including brinase gave a linear relationship between the logarithm of the enzyme concentration and the diameter of the circular lysed zone. A similar linearity of dose-response curves has frequently been found by investigators who used enzyme plate assays with substrates different from fibrin incorporated in an agar gel. Consequently, it seems that this linearity of dose-response curves is generally valid for the fibrin plate assay as well as for other enzyme plate bioassays.Both human plasmin and porcine tissue activator of plasminogen showed deviations from linearity of semi-logarithmic dose-response curves in the fibrin plate assay.

BIOASSAY OF THYROID HORMONE USING HYPOTHYROID TADPOLES

1962 ◽  
Vol 41 (1) ◽  
pp. 143-153 ◽  
Author(s):  
U. Henriques
Keyword(s):  
Thyroid Hormone ◽  
Dose Response ◽  
Developmental Rate ◽  
Response Curves ◽  
Sodium Salts ◽  
Dose Response Curves

ABSTRACT A bioassay of thyroid hormone has been developed using Xenopus larvae made hypothyroid by the administration of thiourea. Only tadpoles of uniform developmental rate were used. Thiourea was given just before the metamorphotic climax in concentrations that produced neoteni in an early metamorphotic stage. During maintained thiourea neotoni, 1-thyroxine and 1-triiodothyronine were added as sodium salts to the water for three days and at the end of one week the stage of metamorphosis produced was determined. In this way identical dose-response curves were obtained for the two compounds. No qualitative differences between their effects were noted except that triiodothyronine seemed more toxic than thyroxine in equivalent doses. Triiodothyronine was found to be 7–12 times as active as thyroxine.

Dose Response Curves for Microwave Ablation in the Cardioplegia-Arrested Porcine Heart

2005 ◽  
Vol 8 (4) ◽  
pp. E269-E274 ◽  
Author(s):  
Sydney L. Gaynor ◽  
Gregory D. Byrd ◽  
Michael D. Diodato ◽  
Yosuke Ishii ◽  
Anson M. Lee ◽  
...  
Keyword(s):  
Dose Response ◽  
Microwave Ablation ◽  
Response Curves ◽  
Porcine Heart ◽  
Dose Response Curves

Modeling Nonmonotonic Dose-Response Curves

2001 ◽  
Author(s):  
Quinton J. Nottingham ◽  
Jeffrey B. Birch ◽  
Barry A. Bodt
Keyword(s):  
Dose Response ◽  
Response Curves ◽  
Dose Response Curves

scholarly journals Comment Concerning the Effects of Light Intensity on Melatonin Suppression in the Review “Light Modulation of Human Clocks, Wake, and Sleep” by A. Prayag et al.

2021 ◽  
Vol 3 (1) ◽  
pp. 181-188
Author(s):  
Peter Bracke ◽  
Eowyn Van de Putte ◽  
Wouter R. Ryckaert
Keyword(s):  
Phase Shift ◽  
Light Intensity ◽  
Dose Response ◽  
Light Modulation ◽  
Response Curves ◽  
Practical Applications ◽  
Circadian Phase ◽  
Melatonin Suppression ◽  
Dose Response Curves ◽  
Circadian Phase Shift

Dose-response curves for circadian phase shift and melatonin suppression in relation to white or monochromatic nighttime illumination can be scaled to melanopic weighed illumination for normally constricted pupils, which makes them easier to interpret and compare. This is helpful for a practical applications.

scholarly journals Nonparametric estimation of population average dose-response curves using entropy balancing weights for continuous exposures

2021 ◽  
Vol 21 (1) ◽  
pp. 69-110 ◽  
Author(s):  
Brian G. Vegetabile ◽  
Beth Ann Griffin ◽  
Donna L. Coffman ◽  
Matthew Cefalu ◽  
Michael W. Robbins ◽  
...  
Keyword(s):  
Nonparametric Estimation ◽  
Dose Response ◽  
Average Dose ◽  
Response Curves ◽  
Entropy Balancing ◽  
Population Average ◽  
Dose Response Curves

Infants Diagnosed with Athyreosis on Scintigraphy May Have a Gland Present on Ultrasound and Have Transient Congenital Hypothyroidism

2021 ◽  
pp. 1-8
Author(s):  
Niamh McGrath ◽  
Colin Patrick Hawkes ◽  
Stephanie Ryan ◽  
Philip Mayne ◽  
Nuala Murphy
Keyword(s):  
Thyroid Gland ◽  
Congenital Hypothyroidism ◽  
Thyroid Tissue ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Ultrasound ◽  
Free T4 ◽  
Median Serum ◽  
Thyroid Glands ◽  
Rule Out

Scintigraphy using technetium-99m (<sup>99m</sup>Tc) is the gold standard for imaging the thyroid gland in infants with congenital hypothyroidism (CHT) and is the most reliable method of diagnosing an ectopic thyroid gland. One of the limitations of scintigraphy is the possibility that no uptake is detected despite the presence of thyroid tissue, leading to the spurious diagnosis of athyreosis. Thyroid ultrasound is a useful adjunct to detect thyroid tissue in the absence of <sup>99m</sup>Tc uptake. <b><i>Aims:</i></b> We aimed to describe the incidence of sonographically detectable in situ thyroid glands in infants scintigraphically diagnosed with athyreosis using <sup>99m</sup>Tc and to describe the clinical characteristics and natural history in these infants. <b><i>Methods:</i></b> The newborn screening records of all infants diagnosed with CHT between 2007 and 2016 were reviewed. Those diagnosed with CHT and athyreosis confirmed on scintigraphy were invited to attend a thyroid ultrasound. <b><i>Results:</i></b> Of the 488 infants diagnosed with CHT during the study period, 18/73 (24.6%) infants with absent uptake on scintigraphy had thyroid tissue visualised on ultrasound (3 hypoplastic thyroid glands and 15 eutopic glands). The median serum thyroid-stimulating hormone (TSH) concentration at diagnosis was significantly lower than that in infants with confirmed athyreosis (no gland on ultrasound and no uptake on scintigraphy) (74 vs. 270 mU/L), and median free T4 concentration at diagnosis was higher (11.9 vs. 3.9 pmol/L). Six of 10 (60%) infants with no uptake on scintigraphy but a eutopic gland on ultrasound had transient CHT. <b><i>Conclusion:</i></b> Absent uptake on scintigraphy in infants with CHT does not rule out a eutopic gland, especially in infants with less elevated TSH concentrations. Clinically, adding thyroid ultrasound to the diagnostic evaluation of infants who have athyreosis on scintigraphy may avoid committing some infants with presumed athyreosis to lifelong levothyroxine treatment.

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