scholarly journals Faeces is a reliable source of body water for measuring tritium in reindeer in summer and in winter

Rangifer ◽  
1995 ◽  
Vol 15 (2) ◽  
pp. 63 ◽  
Author(s):  
Geir Gotaas ◽  
Nicholas J.C. Tyler
Keyword(s):  
Intravenous Injection ◽  
Adult Female ◽  
Half Life ◽  
Rumen Fluid ◽  
Body Water ◽  
Tritium Concentration ◽  
Free Living ◽  
Water Compartments ◽  
Reliable Source ◽  
Three Body

Rates of equilibration and subsequent wash-out of tritium were measured in parallel samples of blood, rumen fluid and faeces collected from two adult female Norwegian reindeer in summer and in winter. The tritium-concentration was the same in all three body water compartments after no more than 9 h following both intravenous and intra-ruminal injection of isotope in summer and following intravenous injection of isotope in winter. The biological half-life of the tritium increased from approximately 3 days in summer to approximately 10 days in winter, probably as a consequence of a decrease in water intake. There were no significant differences in disappearance rates of tritium from blood, rumen fluid and faeces within any of the six experiments. Fresh faeces is therefore a reliable source of body water that can be used in place of blood in studies of body water kinetics in reindeer, thus making it potentially possible to conduct such studies on truly free-living and undisturbed animals.

Turnover of Sodium and Water by Free-Living Rabbits, Oryctolagus Cuniculus.

1978 ◽  
Vol 5 (1) ◽  
pp. 93 ◽  
Author(s):  
B Green ◽  
J Dunsmore ◽  
H Bults ◽  
K Newgrain
Keyword(s):  
Water Content ◽  
Water Conservation ◽  
Half Life ◽  
Oryctolagus Cuniculus ◽  
Body Water ◽  
Water Turnover ◽  
Free Living ◽  
Blood Samples ◽  
Mean Values ◽  
South Wales

Four places in New South Wales were chosen that had a permanent water supply and vegetation with very low or very high Na content, or no surface water during the study and medium, or low to medium, Na content. Wild rabbits (Oryctolagus cuniculus) were caught in those places, given 22NaCl and 3H2O by intraperitoneal injection and held for 4 to 5 h, then blood samples were taken and the rabbits were weighed, marked and released at the point of capture. After another 8 to 23 days they were recaptured and weighed, and blood samples were taken. Between the 7 or 8 values for different places and dates, mean bodyweight ranged from 937 to 1650 g, exchangeable Na from 37.37 to 50.10 mEq/kg bodyweight or 48.78 to 67.93 mEq/litre body water, Na turnover from 0.51 to 13.95 mEq/kg bodyweight daily, Na biological half-life from 2.3 to 55.0 days, total body water 677 to 777 ml/kg, water turnover 88 to 375 ml/kg daily and water half-life 1.4 to 5.6 days. Mean values are for groups of 4 to 25 rabbits. Between the 4 places, water content of vegetation ranged from 142 to 832 mg/kg fresh vegetation and, including 2 sites at one of the 4 places, Na content ranged from 0.51 to 20.98 mEq/kg fresh and 2.41 to 124.9 mEq/kg dry matter. There was a positive linear relation between Na in fresh vegetation and Na turnover rate in rabbits. The relation between water content of vegetation and water turnover in rabbits was not precise, because probably of such factors as diet selection, rain and accessibility and use of water. Lactation may have a strong effect on rabbits when water or Na is scarce, because rabbits may not ingest the faeces and urine of their young like other animals.Low rate of water turnover, especially after metabolic weight correction, demonstrated the efficiency of water conservation of rabbits and partly explained their success in dry places. Published values for other species are compared. Food items were not identified in the present work, but identification and analysis of their Na content would allow qualitative calculation of the food intake of free-living herbivores from their Na turnover.

Turnover of Human Extrinsic (Tissue-Type) Plasminogen Activator in Rabbits

1981 ◽  
Vol 46 (03) ◽  
pp. 658-661 ◽  
Author(s):  
C Korninger ◽  
J M Stassen ◽  
D Collen
Keyword(s):  
Plasminogen Activator ◽  
Intravenous Injection ◽  
Active Site ◽  
Half Life ◽  
Degradation Products ◽  
Gel Filtration ◽  
Tissue Type ◽  
Organ Distribution ◽  
Small Rise

SummaryThe turnover of highly purified human extrinsic plasminogen activator (EPA) (one- and two-chain form) was studied in rabbits. Following intravenous injection, EPA-activity declined rapidly. The disappearance rate of EPA from the plasma could adequately be described by a single exponential term with a t ½ of approximately 2 min for both the one-chain and two-chain forms of EPA.The clearance and organ distribution of EPA was studied by using 125I-labeled preparations. Following intravenous injection of 125I-1abeled EPA the radioactivity disappeared rapidly from the plasma also with a t ½ of approximately 2 min down to a level of 15 to 20 percent, followed by a small rise of blood radioactivity. Gel filtration of serial samples revealed that the secondary increase of the radioactivity was due to the reappearance of radioactive breakdown products in the blood. Measurement of the organ distribution of 125I at different time intervals revealed that EPA was rapidly accumulated in the liver, followed by a release of degradation products in the blood.Experimental hepatectomy markedly prolonged the half-life of EPA in the blood. Blocking the active site histidine of EPA had no effect on the half-life of EPA in blood nor on the gel filtration patterns of 125I in serial plasma samples.It is concluded that human EPA is rapidly removed from the blood of rabbits by clearance and degradation in the liver. Recognition by the liver does not require a functional active site in the enzyme. Neutralization in plasma by protease inhibitors does not represent a significant pathway of EPA inactivation in vivo.

Robust three-body water simulation model

2011 ◽  
Vol 134 (18) ◽  
pp. 184501 ◽  
Author(s):  
C. J. Tainter ◽  
P. A. Pieniazek ◽  
Y.-S. Lin ◽  
J. L. Skinner
Keyword(s):  
Simulation Model ◽  
Body Water ◽  
Water Simulation ◽  
Three Body

BODY WATER COMPARTMENTS IN THE PREMATURE INFANT, WITH SPECIAL REFERENCE TO THE EFFECTS OF THE RESPIRATORY DISTRESS SYNDROME AND OF MATERNAL DIABETES AND TOXEMIA

PEDIATRICS ◽  
1962 ◽  
Vol 29 (6) ◽  
pp. 883-889
Author(s):  
Wesley M. Clapp ◽  
L. Joseph Butterfield ◽  
Donough O'Brien
Keyword(s):  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Total Body Water ◽  
Distress Syndrome ◽  
Body Water ◽  
Control Group ◽  
Extracellular Water ◽  
Water Compartments ◽  
Significant Difference ◽  
Total Body

Normal values for both total body water and extracellular water have been determined in 86 premature infants aged 1 to 90 days and weighing 940 to 2,435 gm, with use of the techniques of deuterium oxide and bromide dilution. Nine full-term infants aged 1 to 6 days and weighing 2,590 to 4,985 gm were similarly studied. Nine infants with the respiratory distress syndrome and eight infants of toxemic mothers studied in the first 24 hours of life showed no significant difference in their body water compartments in comparison to a control group of normal infants matched for age and weight. Seven infants of diabetic mothers studied in the first 24 hours of life showed a significant decrease in total body water, expressed as percentage of body weight, with a normal intracellular to extracellular water ratio. These data indirectly support other evidence that there is an increase in body fat in these infants at birth. See Table in the PDF file

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.

Pharmacokinetics and Tissue Residues of Sulfathiazole and Sulfamethazine in Pigs

1994 ◽  
Vol 57 (9) ◽  
pp. 796-801 ◽  
Author(s):  
LIEVE S. G. VAN POUCKE ◽  
CARLOS H. VAN PETEGHEM
Keyword(s):  
Intravenous Injection ◽  
Half Life ◽  
Intramuscular Injection ◽  
Compartment Model ◽  
Absolute Bioavailability ◽  
Pharmacokinetic Parameters ◽  
Tissue Concentrations ◽  
Single Intravenous Injection ◽  
The Individual ◽  
Residue Study

The plasma pharmacokinetics and tissue penetration of sulfathiazole (ST) and sulfamethazine (SM) after intravenous and intramuscular injection in pigs were studied. Following a single intravenous dose of 40 mg ST/kg of bodyweight or 80 mg SM/kg of bodyweight, the plasma ST and SM concentrations were best fitted to a two-compartment model. The areas under the curve were 447 ± 39 and 1485 ± 41 mg/h/L, clearances were 0.090 ± 0.007 and 0.054 ± 0.001 L/kg/h, volumes of distribution were 1.16 ± 0.16 and 0.77 ± 0.06 L/kg, half-lifes in distribution phase were l.18 ± 0.57 and 0.23 ± 0.16 h and half-lifes in eliminations phase were 9.0 ± l.6 and 9.8 ± 0.6 h. When the two compounds were administered simultaneously as a single intravenous injection, the pharmacokinetic parameters for ST were not significantly different. The values for SM show statistical differences for some important parameters: α, β and the AUC0–>∞ were significantly decreased and t1/2α, Vd and CIB were significantly increased. It can be concluded that after a single intravenous injection of 40 mg/kg, sulfathiazole has a high tl/2β resulting in higher tissue concentrations. This half-life, which is higher than what is reported in the literature, is not influenced by the simultaneous presence of sulfamethazine. The tl/2β for sulfamethazine after a single intravenous injection of 80 mg/kg is comparable to the data from the literature and is not influenced by the presence of sulfathiazole. Sulfathiazole and SM were also administered simultaneously as an intramuscular injection to healthy pigs at a dosage of 40 and 80 mg/kg bodyweight. Pharmacokinetic experiments were conducted on three pigs. From this pharmacokinetic study it can be concluded that upon a single intramuscular administration of 40 mg/kg of ST and 80 mg/kg of SM the absolute bioavailability in pigs is 0.92 ± 0.04 for ST and l.01 ± 0.07 for SM. Six pigs received five intramuscular im) injections as a single dose of ST and SM every 24 h for five consecutive days for the residue study. The pigs were slaughtered at different times after the last dose was given and samples were taken from various tissues and organs. Concentrations were determined by a microbiological method and a HPTLC method. No edible tissue contained more than 100 μg/kg of the individual sulfonamides after 10 days of withdrawal. It means that adult animals which have a shorter half-life and thus lower tissue concentrations will certainly meet the economic community EC) maximum residue limits after a 10 days withdrawal period.

Analytic assessment of the various bioimpedance methods used to estimate body water

1998 ◽  
Vol 84 (5) ◽  
pp. 1801-1816 ◽  
Author(s):  
J. Matthie ◽  
B. Zarowitz ◽  
A. De Lorenzo ◽  
A. Andreoli ◽  
K. Katzarski ◽  
...  
Keyword(s):  
Body Water ◽  
Intracellular Water ◽  
Single Frequency ◽  
Fluid Distribution ◽  
Good Prediction ◽  
Extracellular Water ◽  
Tissue Change ◽  
Water Compartments ◽  
Water Conduction ◽  
Total Body

Knowledge of patient fluid distribution would be useful clinically. Both single-frequency (SF) and impedance modeling approaches are proposed. The high intercorrelation between body water compartments makes determining the best approach difficult. This study was conducted to evaluate the merits of an SF approach. Mathematical simulation was performed to determine the effect of tissue change on resistance and reactance. Dilution results were reanalyzed, and resistance and parallel reactance were used to predict the intracellular water for two groups. Results indicated that the amount of intracellular and extracellular water conduction at any SF can vary with tissue change, and reactance at any SF is affected by all tissue parameters. Modeling provided a good prediction of dilution intracellular and extracellular water, but an SF method did not. Intracellular, extracellular, and total body water were equally predicted at all frequencies by SF resistance and parallel reactance. Extracellular and intracellular water are best measured through modeling, because only at the zero and infinite frequencies are the results sensitive only to extracellular and intracellular water. At all other frequencies there are other effects.

scholarly journals Evaluation of antibiotics as a methodological procedure to inhibit free-living and biofilm bacteria in marine zooplankton culture

2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 733-746 ◽  
Author(s):  
Vanessa O. Agostini ◽  
Alexandre J. Macedo ◽  
Erik Muxagata
Keyword(s):  
Half Life ◽  
Culture Medium ◽  
Metabolic Inhibitors ◽  
Penicillin G ◽  
Streptomycin Sulphate ◽  
Free Living ◽  
Marine Zooplankton ◽  
Scientific Experiments ◽  
Biofilm Bacteria

There is a problem with keeping culture medium completely or partially free from bacteria. The use of prokaryotic metabolic inhibitors, such as antibiotics, is suggested as an alternative solution, although such substances should not harm non-target organisms. Thus, the aim of this study was to assess the effectiveness of antibiotic treatments in inhibiting free-living and biofilm bacteria and their half-life in artificial marine environment using the copepod Acartia tonsa as bioindicador of non-harmful antibiotic combinations. Regarding to results, the application of 0.025 g L-1 penicillin G potassium + 0.08 g L-1 streptomycin sulphate + 0.04 g L-1 neomycin sulphate showed great potential for use in marine cultures and scientific experiments without lethal effects to non-target organisms. The effect of this combination starts within the first six hours of exposure and reduces up to 93 % the bacterial density, but the half-life is short, requiring replacement. No adverse changes in water quality were observed within 168 hours of exposure. As a conclusion, we can infer that this treatment was an effective procedure for zooplankton cultures and scientific experiments with the aim of measuring the role of free-living and biofilm in the marine community.

Surfactant metabolism of newborn lamb lungs studied in vivo

1980 ◽  
Vol 49 (6) ◽  
pp. 1091-1098 ◽  
Author(s):  
A. Jobe ◽  
M. Ikegami ◽  
I. Sarton-Miller ◽  
L. Barajas
Keyword(s):  
Palmitic Acid ◽  
Intravenous Injection ◽  
Half Life ◽  
Lamellar Body ◽  
Lung Parenchyma ◽  
Newborn Lamb ◽  
Specific Activities ◽  
Life Values ◽  
Surfactant Metabolism

Surfactant, microsomal, and lamellar body fractions were isolated from the lungs of 5-day-old lambs 0.21-55 h after the intravenous injection of radiolabeled palmitic acid. The specific activities as cpm/mumol phospholipid phosphate of phosphatidylcholine, saturated phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine were measured. The palmitate-labeled phospholipids disappeared from the lung parenchyma with a half-life of approximately 50 h. The radiolabel disappeared from phosphatidylcholine, saturated phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine of microsomal fractions with initial half-life values of 4.5, 4.6, 1.9, and 23.9 h, respectively. The labeled phospholipids rapidly appeared in the lamellar body fraction and accumulated in the surfactant of the lambs in a linear fashion for 35 h. The curves for the labeling of surfactant with radiolabeled saturated phosphatidylcholine, phosphatidylglycerol, and phosphatidylethanolamine were similar to the curve for phosphatidylcholine.

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