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.

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.

BIOLOGICAL HALF-LIFE OF CAFFEINE IN PIGS

1970 ◽  
Vol 50 (1) ◽  
pp. 49-54 ◽  
Author(s):  
H. M. CUNNINGHAM
Keyword(s):  
Oral Dose ◽  
Water Content ◽  
Single Oral Dose ◽  
Plasma Levels ◽  
Half Life ◽  
Intramuscular Injection ◽  
Peak Plasma ◽  
Growing Pigs ◽  
Sufficient Time ◽  
Biological Half Life

Five experiments were conducted with growing pigs to determine the biological half-life of caffeine after injection or various periods of ingestion. Peak plasma caffeine levels were reached within 5 hr after a single oral dose and 2 hr after intramuscular injection, and then declined with a biological half-life of about 12 hr. The caffeine content of tissues was approximately proportional to their water content and 6% of orally administered caffeine was excreted in the urine. Upon continuous ingestion of caffeine, peak plasma levels were reached within 2 days, indicating that accumulation was quite limited. When 1.5 g of caffeine per kg of feed was fed from weaning to market weight, the withdrawal of caffeine 2 days prior to slaughter was sufficient time to insure that caffeine levels in the liver, muscle, kidney and backfat were below 1 μg/g.

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.

scholarly journals Vitamin B12metabolism in the fruit bat (Rousettus aegyptiacus). The induction of vitamin B12deficiency and its effect on folate levels.

1975 ◽  
Vol 34 (3) ◽  
pp. 397-410 ◽  
Author(s):  
Susan V. van Tonder ◽  
J. Metz ◽  
R. Green
Keyword(s):  
Half Life ◽  
Serum Vitamin ◽  
Early Spring ◽  
Serum Folate ◽  
Vitamin B ◽  
Fruit Bat ◽  
Biological Half Life ◽  
Wide Range ◽  
In Captivity ◽  
In The Wild

1. Vitamin B12metabolism was studied in bats of the speciesRousettus aegyptiacus, which live on an all-fruit diet in the wild.2. There was a wide range in values for the serum vitamin B12concentration of newly captured bats, but bats captured in the early spring had significantly higher mean serum vitamin B12levels than bats captured in the early autumn.3. There was an exponential decrease in serum vitamin B12concentration with time in captivity for bats fed on a vitamin B12-deficient, all-fruit diet; the biological half-life was 80 d in serum, 109 d in liver and 164 d in kidney.4. The main storage organ for vitamin B12in the bat was the liver, mean content 1067 ng vitamin B12. After 50 d, injected [57Co]cyanocobalamin had equilibrated with body vitamin B12stores, and 17% of the retained radioactivity was present in the liver. From these results it was calculated that the total body vitamin B12content of the bat wasc.6500 ng.5. The biological half-life of injected [57Co]cyanocobalamin was 70–88 d and the calculated daily requirement was 50–60 ng (0.2 μg/kg body-weight per d).6. As serum vitamin B12levels decreased, serum folate levels increased. The erythrocyte folate concentration increased significantly after 130 d on the all-fruit diet and then decreased to the initial values after 190 d.7. Vitamin B12metabolism in the fruit bat is similar in many respects to that of man, but on a ‘weight-for-weight’ basis the bat has a 5- to 15-fold greater requirement for this vitamin.8. Vitamin B12deficiency may be induced fairly rapidly in fruit bats fed on an all-fruit diet.

scholarly journals Biological Half-life of Vitamin B12 in Plasma

Nature ◽  
1963 ◽  
Vol 198 (4876) ◽  
pp. 200-200 ◽  
Author(s):  
J. F. ADAMS
Keyword(s):  
Vitamin B12 ◽  
Half Life ◽  
Biological Half Life

Eine für die Berechnung der intestinalen Vitamin B12-Resorption beim Menschen sowohl im physiologischen, Intrinsic Factor-abhängigen als auch im unphysiologisch hohen, diffusionsbedingten Dosisbereich allgemein gültige Formel

1965 ◽  
Vol 20 (11) ◽  
pp. 1067-1069 ◽  
Author(s):  
H. C. Heinrich ◽  
E. E. Gabbe ◽  
D D. H. Whang ◽  
E. Wolfsteller
Keyword(s):  
Dose Range ◽  
Intrinsic Factor ◽  
Whole Body ◽  
Vitamin B ◽  
Human Beings ◽  
Body Retention ◽  
Detector Geometry ◽  
High Doses ◽  
Liquid Organic Scintillator ◽  
Diffusion Absorption

The intestinal absorption of pure 60Co-cyanocobalamin was measured in human beings in the dose range between 0.10 and 100,000 µg with the radio-vitamin B12-absorption-whole body retentiontest. The 60Co-vitamin B12-whole body-retention was measured within the 200 cm long 4 п detector geometry of a large volume radioactivity detector with liquid organic scintillator. The estimated intestinal 60Co-vitamin B12 absorption in man can be described for the whole dose range (0.10 —100,000 µg) by two equations which contain expressions for the intrinsic factordependent vitamin B12 absorption and the diffusion absorption of vitamin B12 [see equations (1) and (2) ]. It is evident from these equations that intrinsic factor-dependent vitamin B12-absorption is limited to 1.5 µg B12/dose whereas the diffusion absorption of vitamin B12 approaches but never exceeds 0.90% of the oral dose. The diffusion absorption rate can be used together with the vitamin B12-whole body turnover rate (~ 2.6 µg/day) as an experimental basis for an efficient oral vitamin B12-therapy with high doses.

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.

scholarly journals Whole-Body Radioiodine Effective Half-Life in Patients with Differentiated Thyroid Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1740
Author(s):  
Michele Klain ◽  
Carmela Nappi ◽  
Marina De Risi ◽  
Leandra Piscopo ◽  
Fabio Volpe ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Half Life ◽  
Differentiated Thyroid Cancer ◽  
Multivariable Analysis ◽  
Whole Body ◽  
131I Therapy ◽  
Retention Data ◽  
Remnant Ablation ◽  
131I Treatment ◽  
Body Retention

Background: Radioactive 131I (RAI) therapy is used in patients with differentiated thyroid cancer (DTC) after total thyroidectomy for remnant ablation, adjuvant treatment or treatment of persistent disease. 131I retention data, which are used to indicate the time at which a 131I treated DTC patient can be released from the hospital, may bring some insights regarding clinical factors that prolong the length of hospitalization. The aim of this study was to investigate the 131I whole-body retention in DTC patients during 131I therapy. Methods: We monitored 166 DTC patients to follow the 131I whole-body retention during 131I therapy with a radioactivity detector fixed on the ceiling of each protected room. A linear regression fit permitted us to estimate the whole-body 131I effective half-life in each patient, and a relationship was sought between patients’ clinical characteristics and whole-body effective 131I half-life. Results: The effective 131I half-life ranged from 4.08 to 56.4 h. At multivariable analysis, longer effective 131I half-life was related to older age and extensive extra-thyroid disease. Conclusions: 131I effective half-life during 131I treatment in DTC patients is highly variable among patients and is significantly longer in older and in patients with RAI uptake in large thyroid remnants or in extrathyroidal disease that significantly prolongs the whole-body retention of 131I.

Turnover rate of skeletal alkaline phosphatase in humans.

1982 ◽  
Vol 28 (1) ◽  
pp. 153-154 ◽  
Author(s):  
S Posen ◽  
H S Grunstein
Keyword(s):  
Alkaline Phosphatase ◽  
Half Life ◽  
Turnover Rate ◽  
Paget’S Disease ◽  
Paget's Disease ◽  
Paget’S Disease Of Bone ◽  
Paget's Disease Of Bone ◽  
Phosphatase Activities ◽  
Biological Half Life ◽  
Skeletal Alkaline Phosphatase

Abstract Two patients with Paget's disease of bone were subjected to plasmapheresis. Alkaline phosphatase activities of serum declined sharply, but returned to preplasmapheresis values within eight to 10 days. The biological half-life of circulating skeletal alkaline phosphatase, as calculated from these experiments, is between 1.12 and 2.15 days.

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