THE FIRST ATTEMPT OF THE BIOKINETIC GA-67 MODEL APPLICATION TO CANINE LIVER CARCINOMA: CASE-CONTROL STUDY VIAIN-VIVOGAMMA CAMERA/8-SLICE CT TECHNIQUE

2018 ◽  
Vol 18 (07) ◽  
pp. 1840019
Author(s):  
CHAO-HSUN CHUANG ◽  
CHIH-FENG CHEN ◽  
NENG-CHUNG TSENG ◽  
KUANG-LI CHAN ◽  
LUNG-FA PAN ◽  
...  
Keyword(s):  
Empirical Data ◽  
Half Life ◽  
Gamma Camera ◽  
Case Control ◽  
Time Dependent ◽  
Whole Body ◽  
Liver Carcinoma ◽  
Ct Technique ◽  
Biokinetic Model ◽  
Biological Half Life

The biokinetic model of Ga-67 evolution was elaborated in this study for the case-control group of canine liver carcinoma via in-vivo gamma camera/8-slice CT technique. One liver carcinoma dog and two normal dogs were anesthetized with the further whole body scanning by a gamma camera to acquire the time-dependent Ga-67 concentration variations among eight compartments, namely: 1. body fluid, 2. liver, 3. GI Tract, 4. kidney, 5. heart, 6. remainder, 7. bladder, and 8. excretion. Each compartment was assumed to have a unique biological half-life and to be connected to other ones. The initial simplification of assigned compartments was performed based on the general-purpose biokinetic model recommended by the ICRP-30 report. Each object/dog underwent eight scans within 72[Formula: see text]h. The time-dependent empirical data were normalized to the maximal counts/pixel/sec and then integrated with the theoretical estimates, in order to optimize the correlations among compartments. A self-developed program run in MATLAB was used to reflect the actual performance acquired from the gamma camera scanning, while the dimensionless agreement (AT) was applied to assess the discrepancies between empirical and theoretical results. An AT of zero implies a perfect agreement between the theoretical and empirical results, while AT under 20 indicates an excellent consistency between the optimal computational and empirical data, whereas a wide fluctuation of the obtained ATs in the range of 7%–60% corresponded to a medium range of data disagreement in this study. The liver carcinoma dog has revealed a longer biological half-life than normal dogs in the limited range (40 versus 35 or 15[Formula: see text]h). However, the quantified data for other compartments and branching ratios among compartments provided a quite robust substantiation for constructing the biokinetic model of Ga-67 being administrated in the canine hepatic survey.

BIOKINETIC MODEL DEVELOPMENT OF RADIOIODINE-131 VIA IN VIVO GAMMA CAMERA/8-SLICE CT TECHNIQUE: CASE-CONTROL STUDY OF FELINE HYPERTHYROIDISM

2018 ◽  
Vol 18 (08) ◽  
pp. 1840035
Author(s):  
CHIH-FENG CHEN ◽  
CHAO-HSUN CHUANG ◽  
PAO-CHEN TANG ◽  
NENG-CHUNG TSENG ◽  
LUNG-FA PAN ◽  
...  
Keyword(s):  
Body Fluid ◽  
Gamma Camera ◽  
Case Control Study ◽  
Case Control ◽  
Time Dependent ◽  
Whole Body ◽  
Biokinetic Model ◽  
Stomach Body ◽  
Control Study

Objectives: A biokinetic model of iodine in the thyroid was developed and applied to a case-control study of hyperthyroid cat undertaken the NaI-131 dose administration using a gamma camera/8-slice CT with the in vivo study. Methods: The case-control hyperthyroid cats were administered 55.5 or 3.7[Formula: see text]MBq of I-131 radioactive solution and continuously surveyed by a gamma camera. The scan schedule was preset as 5- or 10-min counting per each hour from the initial time to the sixth hour, then on the 24th, 48th and 72nd hours, respectively. An in-house developed program run in the MATLAB was applied to evaluate the biokinetic model of iodine in the thyroid, in compliance with the ICRP-30 report regulations. The model was defined by five compartments (namely: stomach, body fluid, thyroid, whole body, and excretion) and allowed one to simulate the variations of time-dependent I-131 radioactive concentration among various compartments of each study subject. The numerical simulation via MATLAB was compiled with the empirical evaluation to optimize the time-dependent concentration of I-131 within the above compartments. Results: The derived biological half-life values for stomach, body fluid, thyroid, whole body, and excretion, respectively, were as follows: 17, 3, 10, 5 and 140[Formula: see text]h for hyperthyroid cat, 18, 1, 8, 2, and 40[Formula: see text]h for control #1 cat, and 22, 2, 12, 4, and 20[Formula: see text]h for control #2 cat. The cumulative radioactive doses from both gamma-ray and beta particles were assessed via a simplified algorithm as 0.135, 0.0082, and 0.005 Gy, for hyperthyroid cat, control #1, and control #2 ones, respectively. Conclusion: The derived biokinetic model was found to be helpful in the evaluation of the metabolic mechanism in case of feline hyperthyroidism. The revealed deviations from available human biomodels can be used for refining the radioiodine treatment of pets with hyperthyroidism.

Enhancement of Tumor Contrast on Radioimmunoscans by Using Mixtures of Monoclonal Antibody F(ab’)2 Fragments

1986 ◽  
Vol 25 (06) ◽  
pp. 216-219 ◽  
Author(s):  
A. Alavi ◽  
H. Koprowski ◽  
D. Herlyn ◽  
D. L. Munz
Keyword(s):  
Monoclonal Antibody ◽  
Gastrointestinal Tract ◽  
Nude Mice ◽  
Half Life ◽  
The Body ◽  
Whole Body ◽  
Antigenic Determinants ◽  
Body Images ◽  
Biological Half Life ◽  
Adenocarcinoma Cells

F(ab’)2 fragments of MAbs GA 73-3 (IgG 2a) and CO 29.11 (IgG 1), which detect distinct antigenic determinants on adenocarcinoma cells of the gastrointestinal tract, were labeled with 131I using the iodogen method. 41 nude mice bearing SW-948 CRC tumors were injected either with a mixture of 100 ¼Ci (11 ¼g) each (n = 9) of the two 131l-F(ab’)2 fragments or with either fragment alone at various doses (each group consisting of 8 mice): GA 73-3,100 ¼Ci (11 ¼g) and 200 ¼Ci (25 ¼g); CO 29.11,100 ¼Ci (11 ¼g) and 200 ¼Ci (26 ¼g). Whole-body images of the mice were obtained daily for up to six days after injection. Ratios of cpm/pixel in the tumor to those in the rest of the body (rob), representing tumor contrast, were significantly (p <0.05) higher in the group of mice injected with the mixture (3.9 ± 1.5) as compared to those given 100 or 200 jiCi of either fragment separately. The biological half-life (T1/2 biol) of the mixture (44.7 ± 14.5 h) in the CRC tumors was significantly (p <0.05) longer than T1/2 biol determined in the groups given either fragment alone. Tv bioL in the rob was similar in all groups of mice examined.

Physikalische und biologische Halbwertzeit von radiochemisch reinem 59Fe / Physical and Biological Half-Life of Radiochemically Pure 59Fe

1971 ◽  
Vol 26 (1) ◽  
pp. 13-20 ◽  
Author(s):  
H. C. Heinrich ◽  
E. E. Gabbe ◽  
D. H. Whang
Keyword(s):  
Anion Exchange ◽  
Half Life ◽  
Turnover Rate ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Iron Loss ◽  
Whole Body ◽  
Body Iron ◽  
Biological Half Life ◽  
Iron Pool

At delivery commercial 59Fe-preparations contain up to 1% contamination by 60Co, 65Zn, 54Mn, 46Sc, 134Cs, etc., so that the physical half-life of such preparations is not constant and starts to increase permanently after about 100 days. Anion exchange chromatography was used to prepare 59Fe with a radiochemical purity of ≧ 99.999999% as demonstrated by analytical anion exchange chromatography, paper- and thin-layer chromatography, and γ-spectroscopy. The physical half-life of radiochemically pure 59Fe was found to be constant over 500 days with 44.52 ± 0.016 days (λ= 0.015568 ± 0.0000056 [d-1]).The whole-body retention of radiochemically pure 59Fe was measured in man over one year with a 4 π-geometry whole-body radioactivity detector and utilized for the estimation of the effective half-life of 59Fe. The correct physical half-life of radiochemically pure 59Fe was used for the calculation of the biological half-life. Normal male subjects showed an effective half-life of 43.6 ± 0.34 days and a biological half-life of 2136 ± 807 days. This means a whole-body-59Fe-turnover rate of 0.032 ± 0.012%/d equivalent to 1.25 ± 0.46 mg Fe/d (for a whole-body iron pool of 3850 mg in a 70 kg man). Menstruating females were observed to have effective half-lives of 43.1 ± 0.22 days and therefore biological half-lives of 1389 ± 224 days. Their whole-body-59Fe-turnover rate is higher (than in males) with 0.050 ± 0.008%/d. For an optimal whole-body iron pool of 3300 mg (in 60 kg female) this would mean an iron loss of 1.65 ± 0.26 mg/d. Non-menstruating females were quite similar to males. They showed effective and biological 59Fe-half-lives of 43.5 ± 0.48 and 1833 ± 857 days, respectively. Their whole-body-59Fe-turnover rate was calculated to be 0.038 ± 0.018%/d or 1.25 ± 0.59 mg Fe/d (60 kg female with 3300 mg Fe-pool). These experimental data are the first direct and reliable proof for the magnitude of daily iron loss and iron requirements in man.

Stoffwechselverhalten des anorganischen Kobalts und des in der Vitamin B12- bzw. Vitamin B12-Coenzym-Struktur organisch gebundenen Kobalts im Säugetier-Organismus

1964 ◽  
Vol 19 (11) ◽  
pp. 1032-1042 ◽  
Author(s):  
H. C. Heinrich ◽  
E. E. Gabbe
Keyword(s):  
Vitamin B12 ◽  
Half Life ◽  
Human Liver ◽  
Intramuscular Injection ◽  
Turnover Rate ◽  
Cobalt Content ◽  
Whole Body ◽  
Vitamin B ◽  
Biological Half Life ◽  
Body Retention

Chromatographically pure, vitamin B12-free 60CoCl2 as well as 60Co-vitamin B12 (60Co-cyanocobalamin and 60Co-aquocobalamin) and 60Co-vitamin B12-coenzyme (60Co-5.6-dimethylbenzimidazol-C5′-deoxyadenosyl-cobamid) were given orally and by injection in smallest amounts (10 — 100 pMol = 0.59-5.9 ng Co2®, 100 pMol = 136 ng vitamin B12 and 100 pMol = 158 ng vitamin B12-coenzyme) to female Sprague-Dawley rats.The whole body retention and excretion of the 60Co label was measured in a large volume radioactivity detector with liquid organic scintillators and 4 π-geometry. The biological half life and whole body metabolic turnover rate were calculated for the inorganic and organic cobalt from the kinetics of the 60Co whole body retention.After oral application of 100 pMol 60Co2® nearly all the 60Co is excreted already after 2 days within the faeces (90%), and the urine (15%). Only about 0.9% of the 60Co2⊕ leaves the rats with a biological half life of 18 days. After intramuscular injection of 100 pMol 60Co2⊕ about 91% of the 60Co are excreted in the urine and 10% in the faeces within four weeks. Only 4.6% of the 60Co2⊕ were eliminated with a biological half life of 28 days. The intramuscular injection of only 10 pMol 60Co2⊕ resulted in a faecal excretion of 82%, and an urinary excretion of 21% of the 60Co. A biological half life of 23 days was calculated for 8.6% of the 60Co2⊕. Inorganic cobalt is therefore practically not retained in the body and rapidly excreted mainly with the urine after injection and mainly within the faeces after oral uptake.In contrast to the inorganic cobalt a completely different metabolic behaviour is typical for the cobalt, which is incorporated in the organic structure of the vitamin B12- and vitamin B12-coenzyme molecules. This organic cobalt accumulates in the storage organs and tissues (kidney, liver etc.) after absorption as well as after injection of 100 pMol 60Co-vitamin B12 and 60Co-vitamin B12coenzyme. Only 15% of the 60Co-cyanocobalamin and 9—10% of the 60Co-aquocobalamin and 60°Covitamin B12-coenzyme are excreted within 48 hours after injection. The organ and tissue incorporated 60Co-vitamin B12 and 60Co-vitamin B12-coenzyme is metabolized with a biological half life of about 52 days. From the whole body pool size of 20 μg vitamin B12 and the biological half life a metabolic turnover rate of 0.27 μg vitamin B12/day or 1.34% of the vitamin-B12-pool per days was calculated for the whole body of the rat.The lacking organ and tissue retention of absorbed and injected 60Co2⊕ and its short biological half life in rats (if compared with the organic cobalt in the vitamin B12-structure) as well as the comparison of the total cobalt content of human liver (measured by physical techniques) with the cobalt content calculated from the vitamin B12-content of human liver (measured by microbiological assay) do not support a biological significance and function of inorganic cobalt in mammals. There is no evidence at the moment that any cobalt besides the cobalt in the vitamin B12 and vitamin B12-coenzymes is existing and biochemically active in humans or animals.

Absorption and Excretion of 3-Chloromercuri-2-Methoxypropylurea Labeled with Hg203

1964 ◽  
Vol 04 (02) ◽  
pp. 193-199
Author(s):  
Leopoldo José Anghileri
Keyword(s):  
Half Life ◽  
Whole Body ◽  
Biological Half Life ◽  
Ionic Mercury

SummaryA method of preparation of Hg203-labelled 3-chloromercuri-2-methoxypropylurea is given. At the same time the solvent to be used in the chromatographic assay of its radioactive purity is indicated.The absorption and excretion of this compound was studied in rats.A maximum of activity was observed in the kidneys during the first six hours. Subsequently the activity in the kidneys decreased whereas it increased in the intestine. After the first week, the biological half life for the whole body was 8 days and for the kidneys approximately 28 days.A high percentage of the activity in the kidneys was ionic mercury.

BIOKINETIC AND DOSIMETRIC ASSESSMENT OF FLUORINE 18 IN HEALTHY VOLUNTEERS SUBJECTED TO 18F–NaF PET/CT BONE SCANS VIA COMPARTMENTAL/MATLAB MODELS AND IN-VIVO STUDY

2018 ◽  
Vol 18 (08) ◽  
pp. 1840022
Author(s):  
PAN-FU KAO ◽  
HSUN-NAN KUO ◽  
SHIH-JYUN LIU ◽  
DA-MING YEH ◽  
LUNG-KWANG PAN
Keyword(s):  
Empirical Data ◽  
Body Fluid ◽  
The Body ◽  
Time Dependent ◽  
Biokinetic Model ◽  
Verification Methods ◽  
Pet Ct ◽  
Input Dataset ◽  
Clinical Verification

Objective: This study quantified the time-dependent concentration of [Formula: see text]F–NaF in critical organs according to a simplified compartmental biokinetic model with clinical verification. Methods: The eleven volunteers were given [Formula: see text][Formula: see text]MBq [Formula: see text]F–NaF administration, then scanned (with 15[Formula: see text]min-collection, every 20[Formula: see text]min, for 200 consecutive min) with a Philips Gemini GXL PET/CT. The empirical data were collected and normalized as the input dataset for MATLAB program. A six-compartmental model was created as a set of time-dependent differential equations and analyzed by the MATLAB to optimize the correlation between the in vivo data and calculated results. The six compartments were: body fluid, bone, kidney, liver, remainder and excretion, while kidney and liver compartments were conventionally split into two subunits with different half-lives to fit properly the empirical data. Results: The average biological half-lives of body fluid, bone, kidney-1, kidney-2, liver-1, liver-2 and the remainder (rest of body) were assessed as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text][Formula: see text]min, respectively. A dimensionless AT index of disagreement between the empirical data and MATLAB optimal solutions was proposed of validating the applied acquisition system and analytical method feasibility. The body fluid and bone AT values did not exceed 20%. The proposed refined equation yielded the internal dose from both gamma- and beta-rays ([Formula: see text] cSv as [Formula: see text] cSv/MBq), which exhibited good correlation with literature (0.00168–0.00270 cSv/MBq). Conclusion: The proposed MATLAB-based fitting of in-vivo data with the theoretical results was instrumental for assessing the radiation dose received by the PET/CT bone scan participants.

Gastroretentive System of Fluvastatin Sodium by Using Natural Mucilage and Synthetic Polymer

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Umamaheswara G. ◽  
Anudeep D.
Keyword(s):  
Half Life ◽  
Release Kinetics ◽  
Kinetic Studies ◽  
Diffusion Path ◽  
Synthetic Polymer ◽  
In Vitro Dissolution ◽  
Direct Compression ◽  
Drug Content ◽  
Biological Half Life

Fluvastatin sodium is a novel compound used as cholesterol lowering agent which acts through the inhibition of 3- hydroxyl-3- methyl glutaryl- coenzyme A (HMG-Co A) reductase. It has short biological half life (1-3h) in humans required a dosing frequency of 20 to 40mg twice a day. Due to its short variable biological half life it has been developed to a sustained gastroretentive system with a natural and synthetic polymer and to study how far the natural mucilage improves the sustained activity. Floating tablets were prepared by direct compression method using in combination of natural mucilage and synthetic polymer. Prior to the preparation of tablets the physical mixtures were subjected to FT IR studies and pre compression parameters. After preparation of tablets they were subjected to various tests like swollen index, drug content, In vitro dissolution and release kinetics with pcp disso software etc. The tablets prepared by direct compression shown good in thickness, hardness and uniformity in drug content, the prepared tablets floated more than 12h except FS1 and FS2 shows 9 and 11h. Swollen index studies shows with increase in concentration of polymer the swelling increases the diffusion path length by which the drug molecule may have to travel and cause lag time. In vitro results shows that on increasing the amount of hibiscus polymer the sustain activity is increased because of its integrity and forms a thick swollen mass and reduces the erosion property of the HypromelloseK100M, kinetic studies shows that FS 1, FS2, FS3 followed the Korsmeyer peppas model and the rest FS 4, FS 5, FS6 follows the zero order respectively. Based on n value indicating that the drug release followed super case II transport mechanism due to the erosion of the polymer.

Development and Characterization of LBG-PVA Interpenetrating Networks Incorporating Gliclazide for Sustained Release

2020 ◽  
Vol 15 ◽  
Author(s):  
Ashish Katoch ◽  
Manju Nagpal ◽  
Malkiet Kaur ◽  
Manjinder Singh ◽  
Geeta Aggarwal ◽  
...  
Keyword(s):  
Solid State ◽  
Sustained Release ◽  
Half Life ◽  
Solid State Nmr ◽  
Oral Dosage ◽  
Cross Linking ◽  
Interpenetrating Networks ◽  
Dsc Studies ◽  
Biological Half Life ◽  
Percentage Yield

Background: Controlled oral dosage forms have always been preferred for drugs with variable absorption, and short biological half life and frequent dosing. The prime goal with sustained release systems is to maintain uniform therapeutic blood levels for longer periods of time. Interpenetrating networks (IPNs) have been evidenced as uniform sustained release systems. In current study, polyvinyl alcohol (PVA) and locust bean gum (LBG) based IPNs were developed for the oral sustained release drug delivery of gliclazide (shows variable absorption). Method: The IPNs were synthesized by emulsion cross-linking method using glutaraldehyde (GA) as a cross linking agent. Gliclazide is a potential second generation, short-acting sulfonylurea oral hypoglycemic agent is having a short biological half-life (2-4 h), variable absorption and poor oral bioavailability. Various batches of IPNs were formulated by varying LBG: PVA ratio and evaluated for percentage yield, drug entrapment efficiency (DEE), swelling properties and in vitro drug release studies. Further characterizations were done by Fourier Transform Infrared Spectroscopy (FTIR), C13 Solid state NMR, X-Ray diffraction study (XRD), Scanning electron microscopy (SEM), and Differential scanning microscopy (DSC) studies. Results: The percentage yield, drug entrapment and equilibrium swelling was observed to be dependent on PVA-LBG ratio and GA amount. Sustained release of drug was observed in all IPN formulations (approx 59 - 86% in 8 h in various batches) with variable release kinetics. SEM studies revealed the regular structures of IPNs. FTIR, XRD, C13 Solid state NMR and DSC studies proposed that drug was successfully incorporated into the formed IPNs. Conclusion: IPNs of LBG and PVA can be used as a promising carrier with uniform sustained release characteristics.

Biological Half-Life of Cardiolite®

2008 ◽  
Vol 46 (9) ◽  
pp. 522-525 ◽  
Author(s):  
Kenneth Jesse
Keyword(s):  
Half Life ◽  
Biological Half Life

Basis for the ICRP’s updated biokinetic model for systemic astatnie

2022 ◽  
Author(s):  
Richard Wayne Leggett ◽  
Caleigh Samuels
Keyword(s):  
Salivary Glands ◽  
Intravenous Injection ◽  
Half Life ◽  
Particle Therapy ◽  
Radiation Hazard ◽  
Radiation Doses ◽  
Tissue Dose ◽  
Biokinetic Model ◽  
Dose Coefficients ◽  
Icrp Publication

Abstract The ICRP recently updated its biokinetic models for workers in a series of reports called the OIR (Occupational Intakes of Radionuclides) series. A new biokinetic model for astatine, the heaviest member of the halogen family, was adopted in OIR Part 5 (ICRP Publication 151, in press). This paper provides an overview of available biokinetic data for astatine; describes the basis for the ICRP’s updated model for astatine; and tabulates dose coefficients for intravenous injection of each of the two longest lived and most important astatine isotopes, 211At and 210At. Astatine-211 (T1/2 = 7.214 h) is a promising radionuclide for use in targeted α-particle therapy due to several favorable properties including its half-life and the absence of progeny that could deliver significant radiation doses outside the region of α-particle therapy. Astatine-210 (T1/2 = 8.1 h) is an impurity generated in the production of 211At in a cyclotron and represents a potential radiation hazard via its long-lived progeny 210Po (T1/2 = 138 d). Tissue dose coefficients for injected 210At and 211At based on the updated model are shown to differ considerably from values based on the ICRP’s previous model for astatine, particularly for the thyroid, stomach wall, salivary glands, lungs, spleen, and kidneys.

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