THE "EFFECTIVE THYROXINE RATIO" – NEW IN VITRO TEST OF THYROID FUNCTION AND ITS CORRELATION WITH FREE THYROXINE

1974 ◽  
Vol 76 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Janusz Nauman ◽  
Alicja Nauman
Keyword(s):  
Pregnant Women ◽  
Normal Subjects ◽  
Free Thyroxine ◽  
In Vitro Test ◽  
High Reproducibility ◽  
Vitro Test ◽  
The Mean ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients

ABSTRACT The effective thyroxine ratio (ETR) and absolute concentration of free thyroxine (AFT4) were estimated in the sera of 31 normal subjects, 27 hyperthyroid patients, 12 hypothyroid patients and 21 euthyroid pregnant women. The mean ETR value in the controls was 1.0 ± 0.18, in the hyperthyroid patients 1.31 ± 0.25, in the hypothyroid patients 0.71 ± 0.21 and in normal pregnant women 0.99 ± 0.24. The mean AFT4 in the normal subjects was 3.0 ± 0.53 ng/100 ml, in the hyperthyroid patients 9.49 ± 2.44 ng/ 100 ml, in the hypothyroid patients 0.58 ± 0.15 ng/100 ml and in the pregnant women 2.84 ± 0.63 ng/100 ml, respectively. High reproducibility of ETR and a significant positive correlation between ETR and AFT4 with r = 0.96 suggest that ETR might be a suitable in vitro test for routine clinical evaluation of the thyrometabolic state.

IN VITRO UPTAKE OF 131I LABELLED L-TRIIODOTHYRONINE BY HUMAN ERYTHROCYTES

1960 ◽  
Vol XXXIII (I) ◽  
pp. 117-133 ◽  
Author(s):  
Thorkild Friis
Keyword(s):  
Pregnant Women ◽  
Normal Subjects ◽  
Human Erythrocytes ◽  
Homologous Serum ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients ◽  
In Vitro Uptake

ABSTRACT The uptake of 131I labelled l-triiodothyronine by erythrocytes was studied in 139 patients in the presence of equal parts of homologous serum. In 54 normal subjects the uptake was found to range from 6 to 10.5 per cent of the added activity, while 3 subjects (5.6 per cent) showed values from 10.5 to 12.2 per cent. Out of 16 hyperthyroid patients 14 (87.5 per cent) had elevated values. There was a distinct relationship between the severity of thyrotoxicosis and the extent of the uptake. Out of 8 hypothyroid patients 4 (50 per cent) had reduced uptake. Among 12 pregnant women uptake was reduced in 10 and among 8 patients on stilboestrol medication it was reduced in 8. Three out of 7 patients with long-standing hepatitis showed reduced erythrocyte uptake. With one exception the uptake was normal in 13 patients with non-toxic goitre, in 8 euthyroid thyroidectomized patients, in 4 euthyroid patients treated with desiccated thyroid, in 6 euthyroid hypermetabolic and in 3 euthyroid hypometabolic patients.

scholarly journals Evaluation of free and total L-thyroxine in serum by a commercial procedure.

1981 ◽  
Vol 27 (1) ◽  
pp. 149-152 ◽  
Author(s):  
M J Obregon ◽  
A Kurtz ◽  
R Ekins ◽  
G Morreale de Escobar
Keyword(s):  
Pregnant Women ◽  
Plasma Proteins ◽  
Diagnostic Value ◽  
Free Thyroxine ◽  
Total Thyroxine ◽  
Dialysis Method ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients ◽  
Normal Controls

Abstract We assessed a commercial kit (Corning Medical) for "free" and total thyroxine determination, results being compared to those obtained by the Ekins and Ellis dialysis method (free thyroxine) and the method of Weeke and Orskov (total thyroxine). The kit procedure permits determination of both free and total thyroxine within 4 to 5 h, and the combined results may disclose changes in binding to plasma proteins that would be missed if only free thyroxine were determined. With both free-thyroxine methods, the values distinguished hyperthyroid patients from normal controls and pregnant women with 100% accuracy, but there was some overlap between hypothyroid patients and controls. Absolute values with the kit procedure often exceed those obtained by dialysis, especially for hypothyroid patients and pregnant women. We conclude that the kit may be of as much diagnostic value as the dialysis method if the limitations regarding absolute values are kept in mind and the test is not used as a substitute for thyrotropin determinations in cases of suspected hypothyroidism.

THE UPTAKE OF 131I TRIIODOTHYRONINE BY RESIN. AN IN VITRO TEST OF THYROID FUNCTION

1961 ◽  
Vol 37 (4) ◽  
pp. 607-615 ◽  
Author(s):  
M. G. Woldring ◽  
A. Bakker ◽  
H. Doorenbos
Keyword(s):  
Thyroid Function ◽  
Plasma Sample ◽  
In Vitro Test ◽  
Red Cell ◽  
Normal Range ◽  
Cell Substrate ◽  
Vitro Test ◽  
Uptake Test ◽  
Hyperthyroid Patients

ABSTRACT A technique is described, which resembles the in vitro red cell triiodothyronine uptake test for the investigation of thyroid function, but which requires only 0.5 ml of plasma. The uptake of radio-triiodothyronine is measured by a method in which resin replaces the erythrocytes. Thus the variable of the red cell substrate is excluded. By means of the resin technique described, an uptake of 14–27 % was found in a group of 130 euthyroid subjects. Fourteen plasma samples from hyperthyroid patients were investigated, which showed an uptake range of 25–40 % (one plasma sample from this group had an uptake of 25.8, i. e. within the normal range). In one case of hypothyroidism, an uptake of 10.7 % was found. It is not yet possible to state the level of uptake below which the diagnosis of hypothyroidism should be considered. The effect of different factors like the quantity of resin, incubationtemperature and incubation-time, pH and others have been investigated. The results are discussed.

A two-step radioimmunoassay for free triiodothyronine in serum.

1987 ◽  
Vol 33 (3) ◽  
pp. 372-376 ◽  
Author(s):  
M G Rajan ◽  
A M Samuel
Keyword(s):  
Pregnant Women ◽  
Solid Phase ◽  
Equilibrium Dialysis ◽  
Normal Subjects ◽  
Free Triiodothyronine ◽  
High Affinity ◽  
The Mean ◽  
Hyperthyroid Patients ◽  
Normal Adults ◽  
Good Agreement

Abstract Using a high-affinity solid-phase-bound antibody (Ka = 1.2 X 10(11) L/mol), we have standardized a two-step radioimmunoassay for free triiodothyronine (FT3) in serum, based on immunoextraction. The method was validated by comparison with an equilibrium-dialysis procedure (r = 0.96) involving RIA of T3 in the dialysate standardized with the same antibody and by a commercial (Liso-Phase, International-CIS) method. The two-step RIA could detect as little as 0.2 pg per milliliter. The mean CVs within and between assays were 9% and 12%, respectively. FT3 values measured in 30 normal adults ranged from 1.77 to 4.77 ng/L. Comparison with ratios of total T3 to thyroxin-binding globulin showed good agreement in normal subjects, pregnant women, and hypothyroid and hyperthyroid patients.

EVALUATION OF THYROID STATUS WITH THE "EFFECTIVE THYROXINE RATIO" (E. T. R.®)

1974 ◽  
Vol 77 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Klaus Kølendorf ◽  
Kaj Siersbæk-Nielsen ◽  
Jens Mølholm Hansen ◽  
Thorkild Friis
Keyword(s):  
Thyroid Function ◽  
Thyroid Function Test ◽  
Free Thyroxine ◽  
Normal Range ◽  
High Positive Correlation ◽  
Function Test ◽  
Free Thyroxine Index ◽  
Hypothyroid Patients ◽  
Hyperthyroid Patients

ABSTRACT A new in vitro thyroid function test, "Effective Thyroxine Ratio" (ETR®) has been tested in 170 patients, and the ETR values in patients with normal and abnormal thyroid function have been compared to the concentration of absolute free thyroxine and free thyroxine index in serum. Among 42 hyperthyroid patients tested with ETR, 13 had values within normal range (30.9 per cent). Three of 18 hypothyroid patients had normal values (16.8 per cent). Eighty-nine per cent of 27 pregnant women and all of 17 patients treated with genuine oestrogens had ETR values within normal range. A high positive correlation was found between values of ETR, absolute free thyroxine in serum (r = 0.62) and free thyroxine index (r = 0.83).

β-Dicalcium Silicate Cement Modified with β-Tricalcium Phosphate: In Vitro Bioactivity and Mechanical Strength

2018 ◽  
Vol 35 ◽  
pp. 9-19 ◽  
Author(s):  
Adil Bouregba ◽  
Hassan Ez-Zaki ◽  
Abdeljebbar Diouri ◽  
Omar Sassi
Keyword(s):  
Zinc Oxide ◽  
Mechanical Strength ◽  
Bismuth Oxide ◽  
Artificial Saliva ◽  
Dicalcium Silicate ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
Vitro Test ◽  
The Mean

Calcium-silicate cement mainly based on dicalcium-silicate (C2S) was synthesized by the mean of solid state reaction. Beta-C3P was added to C2S to obtain C2S-C3P. Zinc oxide and bismuth oxide was incorporated to prepare radioc cement. In this work, the bioactivity and the mechanical strength of the synthesized cement were investigated. The in vitro test was carried out by immersion of cement pastilles in the artificial saliva in different periods from 4 hours to 30 days. Whereas the mechanical strength of some samples was operated at 28 and 72 days. The specimens are characterized by X-ray diffraction , Infrared spectroscopy and scanning electron microscopy. The finding results indicated that hydroxyapatite may appear after 24 hours of soaking; it was also shown that the presence of C3P with a small amount of the cement can enhance the bioactivity and develop more resistance strength of cement. Moreover, the addition of zinc oxide and bismuth oxide increase the radiopacity of the cement. However, the mechanical strength enhances with the incorporation of the zinc oxide while decrease with bismuth oxide. It was concluded then that there is possibility of combining addition of C3P (10%) and an agent radiopacifiers ZnO/Bi2O3(15%) with small amounts on C2S to obtain a cement with excellent bioactivity, good mechanical strength and significante radiopacity that makes this material a great candidate as a biomaterial for biomedical use.

Haemostatic Platelet Plug Formation in the Isolated Rabbit Mesenteric Preparation - An Analysis of Red Blood Cell Participation

1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors
Keyword(s):  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
In Vitro Test ◽  
Pharmacological Agents ◽  
Vitro Test ◽  
Releasing Effect ◽  
Plug Formation

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.

scholarly journals In Vitro Newly Isolated Environmental Phage Activity against Biofilms Preformed by Pseudomonas aeruginosa from Patients with Cystic Fibrosis

2021 ◽  
Vol 9 (3) ◽  
pp. 478
Author(s):  
Ersilia Vita Fiscarelli ◽  
Martina Rossitto ◽  
Paola Rosati ◽  
Nour Essa ◽  
Valentina Crocetta ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
In Vitro Test ◽  
Chronic Infections ◽  
Hospital Environments ◽  
Vitro Test ◽  
General Reliability ◽  
Phage Activity

As disease worsens in patients with cystic fibrosis (CF), Pseudomonas aeruginosa (PA) colonizes the lungs, causing pulmonary failure and mortality. Progressively, PA forms typical biofilms, and antibiotic treatments determine multidrug-resistant (MDR) PA strains. To advance new therapies against MDR PA, research has reappraised bacteriophages (phages), viruses naturally infecting bacteria. Because few in vitro studies have tested phages on CF PA biofilms, general reliability remains unclear. This study aimed to test in vitro newly isolated environmental phage activity against PA isolates from patients with CF at Bambino Gesù Children’s Hospital (OBG), Rome, Italy. After testing in vitro phage activities, we combined phages with amikacin, meropenem, and tobramycin against CF PA pre-formed biofilms. We also investigated new emerging morphotypes and bacterial regrowth. We obtained 22 newly isolated phages from various environments, including OBG. In about 94% of 32 CF PA isolates tested, these phages showed in vitro PA lysis. Despite poor efficacy against chronic CF PA, five selected-lytic-phages (Φ4_ZP1, Φ9_ZP2, Φ14_OBG, Φ17_OBG, and Φ19_OBG) showed wide host activity. The Φ4_ZP1-meropenem and Φ14_OBG-tobramycin combinations significantly reduced CF PA biofilms (p < 0.001). To advance potential combined phage-antibiotic therapy, we envisage further in vitro test combinations with newly isolated phages, including those from hospital environments, against CF PA biofilms from early and chronic infections.

In Vitro Toxicology Methods in Risk Assessment

1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase
Keyword(s):  
Risk Assessment ◽  
Hazard Assessment ◽  
Human Health Risk ◽  
In Vitro Test ◽  
In Vitro Methods ◽  
New Concepts ◽  
Vitro Test

The title of this paper is challenging, because the question of how in vitro methods and results contribute to human health risk assessment is rarely considered. The process of risk assessment usually begins with hazard assessment, which provides a description of the inherent toxicological properties of the chemical. The next step is to assess the relevance of this to humans, i.e. the human hazard assessment. Finally, information on exposure is examined, and risk can then be assessed. In vitro methods have a limited, but important, role to play in risk assessment. The results can be used for classification and labelling; these are methods of controlling exposure, analogous to risk assessment, but without considering exposure. The Ames Salmonella test is the only in vitro method which is incorporated into regulations and used widely. Data from this test can, at best, lead to classification of a chemical with regard to genotoxicity, but cannot be used for classification and labelling on their own. Several in vitro test systems which assess the topical irritancy and corrosivity of chemicals have been reasonably well validated, and the results from these tests can be used for classification. The future development of in vitro methods is likely to be slow, as it depends on the development of new concepts and ideas. The in vivo methods which currently have reasonably developed in vitro alternatives will be the easiest to replace. The remaining in vivo methods, which provide toxicological information from repeated chronic dosing, with varied endpoints and by mechanisms which are not understood, will be more difficult to replace.

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