DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

1969 ◽  
Vol 61 (2) ◽  
pp. 219-231 ◽  
Author(s):  
V. H. Asfeldt
Keyword(s):  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Cushing's Syndrome ◽  
Dexamethasone Suppression Test ◽  
Clinical Value ◽  
Suppression Test ◽  
The One ◽  
Steroid Excretion ◽  
Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

Pressor responses to norepinephrine in humans before and after corticosteroids

1962 ◽  
Vol 203 (5) ◽  
pp. 961-963 ◽  
Author(s):  
Mohinder P. Sambhi ◽  
Max H. Weil ◽  
Vasant N. Udhoji
Keyword(s):  
Human Subject ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Variance Analysis ◽  
Acute Administration ◽  
Intravenous Injections ◽  
Pressor Responses ◽  
Before And After

Pressor responses produced by intravenous injections of graded doses of norepinephrine were recorded in ten normal subjects before and after pharmacologic doses of glucocorticoids. Two subjects had been pretreated with 9α-fluorocortisol. Although a considerable variation was found in the responsiveness to repeated norepinephrine injections, variance analysis demonstrated that administration of adrenal cortical hormones and their analogues did not significantly alter the response. These observations do not support the hypothesis that acute administration of corticosteroids in large doses potentiates the pressor effects of catecholamines in the human subject with normal adrenal function.

The SimulTRAC FT4/TSH assay evaluated as a first-line thyroid-function test.

1988 ◽  
Vol 34 (7) ◽  
pp. 1488-1491 ◽  
Author(s):  
R K Desai ◽  
W M Deppe ◽  
R J Norman ◽  
T Govender ◽  
S M Joubert
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Thyroid Status ◽  
First Line ◽  
Dual Isotope ◽  
Function Test ◽  
Clinical Conditions ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients ◽  
Underlying Pathology

Abstract We evaluated the SimulTRAC FT4 57Co/TSH 125I dual-isotope assay for the simultaneous measurement of free thyroxin (FT4) by radioimmunoassay analog techniques and of thyrotropin (TSH) by immunoradiometry. Inter- and intra-assay CVs were less than 10% over the entire range tested except for 15.9% at the lowest FT4 concentration. Results obtained by the SimulTRAC assay allowed complete differentiation of 85 hyperthyroid patients and 35 hypothyroid patients from normal subjects. However, such estimations of FT4 or TSH concentrations occasionally were misleading for assessing thyroid status in various clinical conditions. We conclude that the SimulTRAC assay has the same inherent disadvantages possessed by FT4 analog and TSH immunoradiometric assays; however, where results of one of the simultaneous assays may be misleading, the results provided by the other may indicate the underlying pathology without requiring an additional assay.

Two types of leptin-responsive gastric vagal afferent terminals: an in vitro single-unit study in rats

1997 ◽  
Vol 273 (2) ◽  
pp. R833-R837 ◽  
Author(s):  
Y. H. Wang ◽  
Y. Tache ◽  
A. B. Sheibel ◽  
V. L. Go ◽  
J. Y. Wei
Keyword(s):  
Inhibitory Effect ◽  
Vagal Afferents ◽  
Neural Signals ◽  
Excitatory Effect ◽  
Leptin Sensitivity ◽  
Before And After ◽  
Afferent Terminals

In vitro gastric vagal afferents' (GVAs) unit activities were recorded from the ventral GVA nerve strands in rats. The responsiveness of 16 GVA terminals to close intra-arterial injection of vehicle (0.1 ml), leptin (350 pmol), and cholecystokinin (CCK)-8 (10 pmol) was analyzed to generate a spike count-versus-time histogram. Data of 5-min spike counts before and after each treatment were normalized by dividing the latter by the former. A quotient (Q) > 1 indicates an excitatory effect, Q < 1 indicates an inhibitory effect, and Q close to 1 indicates no effect. Two types of GVA terminals were identified. Type 1 (n = 8) responded to leptin with Q > 1; CCK-8 pretreatment did not consistently alter leptin sensitivity. In contrast, Type 2 (n = 8) responded to leptin with Q < 1 or close to 1, and CCK-8 pretreatment increased the leptin sensitivity so that the terminals responded to subsequent leptin with Q > 1. These data suggest that Type 1 and Type 2 GVA terminals may provide afferent neural signals, which, in turn, will be involved in body weight and food intake control systems, respectively.

scholarly journals DETERMINATION OF l-HISTIDINE IN NANOGRAM AMOUNTS AND THE QUESTION OF ITS OCCURRENCE IN MAST CELLS

1972 ◽  
Vol 20 (11) ◽  
pp. 917-922 ◽  
Author(s):  
DAVID I. WILKINSON ◽  
DAVID GLICK
Keyword(s):  
Mast Cells ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Peritoneal Mast Cells ◽  
Before And After ◽  
Chromatographic Detection ◽  
Rat Peritoneal Mast Cells ◽  
Rate Limiting

In an attempt to clarify the question of whether histidine is stored in the mast cell for coversion to histamine or whether the rate of conversion is rapid enough to prevent accumulation of histidine so that the rate-limiting step is the histidine uptake, it was found that no histidine was demonstrable in rat peritoneal mast cells by either quantitative analysis or paper chromatographic detection. Microadaptation of Hassall's method, based on conversion of l-histidine by histidase to urocanic acid and measurement of the latter by its absorbance at 277 nm, was made to permit determination of histidine in nanogram amounts in the presence of histamine. This adaptation was found reliable when compared with the o-phthalaldehyde method in estimation of l-histidine in serum and in insulin hydrolysate, and then it was applied to analysis of mast cells before and after l-histidine uptake in vitro. The adaptation should be generally useful in microanalysis of l-histidine in histologically and cytologically defined samples.

scholarly journals Hot-Stage Microscopy for Determination of API Particles in a Formulated Tablet

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Michal Šimek ◽  
Veronika Grünwaldová ◽  
Bohumil Kratochvíl
Keyword(s):  
Active Pharmaceutical Ingredient ◽  
Assessment Method ◽  
Hot Stage Microscopy ◽  
Tablet Disintegration ◽  
Before And After ◽  
In Vitro Assessment ◽  
Active Substances ◽  
Good Agreement

Although methods exist to readily determine the particle size distribution (PSD) of an active pharmaceutical ingredient (API) before its formulation into a final product, the primary challenge is to develop a method to determine the PSD of APIs in a finished tablet. To address the limitations of existing PSD methods, we used hot-stage microscopy to observe tablet disintegration during temperature change and, thus, reveal the API particles in a tablet. Both mechanical and liquid disintegration were evaluated after we had identified optimum milling time for mechanical disintegration and optimum volume of water for liquid disintegration. In each case, hot-stage micrographs, taken before and after the API melting point, were compared with image analysis software to obtain the PSDs. Then, the PSDs of the APIs from the disintegrated tablets were compared with the PSDs of raw APIs. Good agreement was obtained, thereby confirming the robustness of our methodology. The availability of such a method equips pharmaceutical scientists with an in vitro assessment method that will more reliably determine the PSD of active substances in finished tablets.

scholarly journals Evaluation of physicochemical and antioxidant properties of nanosized copolymeric micelles loaded with kaempferol

Pharmacia ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 49-54
Author(s):  
Krassimira Yoncheva ◽  
Nadia Hristova-Avakumova ◽  
Vera Hadjimitova ◽  
Trayko Traykov ◽  
Petar Petrov
Keyword(s):  
Antioxidant Activity ◽  
Propylene Oxide ◽  
Encapsulation Efficiency ◽  
Antioxidant Properties ◽  
In Vitro Release ◽  
Before And After ◽  
Poly Propylene ◽  
Vitro Release

The study was focused on the evaluation of two copolymers as micellar carriers for kaempferol delivery. The copolymers comprised identical hydrophilic blocks of poly(2-(dimethylamino)ethyl methacrylate and different hydrophobic blocks of either poly(ε-caprolactone) (PDMAEMA9-b-PCL70-b-PDMAEMA9) or poly(propylene oxide) (PDMAEMA13-b-PPO69-b-PDMAEMA13). The calculation of Flory-Huggins parameters and determination of encapsulation efficiency showed that PDMAEMA-b-PCL-b-PDMAEMA copolymer possessed higher capacity for kaempferol loading. The diameter of the micelles before and after lyophilization was not changed, suggesting that the micelles could be lyophilized and redispersed before administration. The in vitro release of kaempferol from PDMAEMA-b-PPO-b-PDMAEMA micelles was faster than the release from PDMAEMA-b-PCL-b-PDMAEMA micelles, probably due to the higher affinity of kaempferol to this copolymer. Further, the higher affinity resulted in a retention of antioxidant activity of kaempferol in the presence of DPPH and KO2 radicals. Thus, PDMAEMA-PCL-PDMAEMA was considered more appropriate carrier because of the higher encapsulation efficiency and preservation of antioxidant activity of the drug.

scholarly journals An in vitro Thyroid Function Test by Res-O-Mat T4 Kit

RADIOISOTOPES ◽  
1971 ◽  
Vol 20 (9) ◽  
pp. 445-451
Author(s):  
Yoshio YONAHARA ◽  
Yoshiko TAKAHARA ◽  
Hiroshi KIRIMURA ◽  
Ichiro KURAMITSU
Keyword(s):  
Thyroid Function ◽  
Thyroid Function Test ◽  
Function Test

PFA-100 monitoring of von Willebrand factor (VWF) responses to desmopressin (DDAVP) and factor VIII/VWF concentrate substitution in von Willebrand disease type 1 and 2

2008 ◽  
Vol 100 (09) ◽  
pp. 462-468 ◽  
Author(s):  
Huub H. D. M. van Vliet ◽  
Mies C. Kappers-Klunne ◽  
Jan J. Michiels ◽  
Frank W. G. Leebeek
Keyword(s):  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Before And After ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryDose-response relationship was studied between PFA-100 closure times (PFA CTs) and factor (F)VIII-von Willebrand factor (VWF) parameters in patients with von Willebrand disease (VWD) type 1 and type 2 before and after treatment with DDAVP (n=84) or FVIII/VWF concentrate (n=38). DDAVP treatment of patients with VWD type 1 normalised the PFA CTs by increasing VWF levels to normal. Of the 14 patients with VWD type 2, PFA CTs did not normalize in eight. Haemate-P substitution in patients with VWD type 1 induced a less favourable response as compared to DDAVP, because PFA CTs did not correct in all patients. Of 12 patients with VWD type 2 treated with Haemate-P, six showed a correction of PFA CTs (<250 sec), which correlated with the normalisation of the VWF CB/ Ag ratio. In-vitro studies were performed by using whole blood of patients with VWD and adding various amounts of FVIII/VWF concentrate. Addition of Haemate-P induced an increase of the VWF CB/Ag ratio from 0.30 to 0.70 in blood of patients with VWD type 2 with correction of the PFA CTs. Immunate did not result in an increase of VWF CB/Ag ratio in blood of VWD type 2 patients, and the PFA CTs remained prolonged. We conclude that PFA-100 might be an adequate instrument not only for diagnosis but also for monitoring of DDAVP responses and FVIII/ VWF substitution of patients with VWD type 1 and 2,but this is dependent upon the type of VWD and the concentrate used.

Ein chromatographisches Verfahren zur Bestimmung typenspezifischer Poliovirus-Antikörper mit 32P-markiertem Polioviru

1963 ◽  
Vol 18 (10) ◽  
pp. 798-808 ◽  
Author(s):  
Reiner Thomssen
Keyword(s):  
Aluminium Hydroxide ◽  
Virus Antibody ◽  
Poliovirus Type ◽  
Specific Antibodies ◽  
In Vitro Technique ◽  
Step Procedure ◽  
Highly Sensitive

A highly sensitive in-vitro technique for determination of homologous type-specific antibodies against polioviruses is described. 32P-labelled poliovirus type 1. strain Mahoney, purified by a three-step-procedure (15 000 rpm, aluminiumhydroxide. Ecteolacellulose) is mixed with homologous type-specific antiserum. After incubation the mixtures are adsorbed to aluminium hydroxide. Virus-antibody-com-plexes are more firmly bound to this adsorbent than virus without antibody: the distinguishing parameter is the concentration of divalent phosphate in the adsorption or the elution fluid. The firmness of binding of virus-antibody-complexes to aluminium hydroxide is further a function of the dilution of antiserum. This leads to a suitable end-point for reading antiserum titers. There is a good correlation between titers determined by this method and titers, determined by common neutralization tests. The method may be used to judge the virus-specifity of radioactivity after purification of 32P-labelled poliovirus.

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