Kinetics of Lampricide (TFM, 3-trifluoromethyl-4-nitrophenol) Residues in Model Stream Communities

1977 ◽  
Vol 34 (2) ◽  
pp. 276-281 ◽  
Author(s):  
Alan W. Maki ◽  
Howard E. Johnson
Keyword(s):  
Half Life ◽  
Water Current ◽  
Uptake Curve ◽  
Linear Rate ◽  
Orconectes Propinquus ◽  
Stream Communities ◽  
Initial Uptake Rate ◽  
Caddisfly Larvae ◽  
Phase Range ◽  
Kinetics Of

The bioconcentration and elimination rates of lamprey larvicide, 14C-TFM (3-trifluoromethyl-4-nitrophenol), were determined for 20 plant and animal species during experimental lamprey control treatments in six indoor model streams. A two-component curve consisting of a rapid initial uptake rate during the first 2 h followed by a reduced linear rate for the remainder of the 24-h exposure best describes the uptake curve for all species examined. The bioconcentration factors (BCF) ranged from 1.1 to 95.5 for animal components and from 0.7 to 12.2 for the plant species. Macroinvertebrate species with soft, relatively permeable integuments accumulate significantly higher residue concentrations (mean BCF = 45.0) than those species with hard chitinized or calcareous exoskeletons (mean BCF = 11.9). Rates of uptake during the linear phase range from 0.36 μg∙g−1∙h−1 for the crayfish Orconectes propinquus to 17.9 μg∙g−1∙h−1 for the caddisfly larvae Brachycentrus americanus.Rates of loss of TFM accumulations correlate with water current and substrate associations. The mean half-life of TFM is 17.8 h for riffle species and 105.9 h for pool-dwelling species. Half-life figures vary from 7.2 h for the crayfish to 5295 h for annelid worms. The longer half-lives observed for several pool species suggest continued accumulation of 14C-labeled residues from the organic matter of the pool bottoms.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

scholarly journals Efficiency and Kinetics of Assam Crude Oil Degradation by Pseudomonas Aeruginosa AKS1 and Bacillus Sp. AKS2

2021 ◽  
Author(s):  
Bobby Chettri ◽  
Ningombam Anjana Singha ◽  
Arvind Kumar Singh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crude Oil ◽  
Liquid Medium ◽  
Half Life ◽  
Liquid Culture ◽  
Oil Degradation ◽  
Biodegradation Rate ◽  
Emulsification Index ◽  
Crude Oil Degradation ◽  
Kinetics Of

Abstract We report kinetics of Assam crude oil degradation by Pseudomonas aeruginosa AKS1 and Bacillus sp. AKS2, both isolated from Assam refinery sediments. The isolates exhibited appreciable degrees of hydrophobicity, emulsification index and biosurfactant production. Crude oil degradation efficiency of isolates was assessed in (1) liquid medium amended with 1% v/v crude oil and (2) microcosm sediments (125 mg crude oil/ 10 g sand). In liquid culture, the biodegradation rate (k) and half-life (t1/2) values were found to be 0.0383 day -1 and 18.09 days for P. aeruginosa AKS1, and 0.0204 day -1 and 33.97 days in case of Bacillus sp. AKS2. In microcosm sand sediments, the estimated biodegradation rate (k) and half-life (t 1/2) values were 0.0138 day -1 and 50 days for P. aeruginosa AKS1, and 0.0113 day -1 and 61.34 days in case of Bacillus sp. AKS2. The level of nutrient treatment in microcosm sand sediment was 125 µg N & 62.5 µg P/g sediment in case of P. aeruginosa AKS1 and 375 µg N & 37.5 µg P/g sediment in case of Bacillus sp. AKS2. In microcosms without inorganic nutrients, biodegradation rate (k) and half-life (t1/2) values were found to be 0.0069 day -1 and 100 days for P. aeruginosa AKS1 and for Bacillus sp. AKS2, the respective values were found to be 0.0046 day -1 and 150.68 days. Our data provides important information for predictive hydrocarbon degradation in liquid medium and contaminated sediments.

scholarly journals Degradation Kinetics of Anthocyanins in Shalgam Beverage

2019 ◽  
Vol 7 (2) ◽  
pp. 282
Author(s):  
Adnan Bozdoğan ◽  
Kurban Yaşar
Keyword(s):  
Activation Energy ◽  
Reaction Kinetics ◽  
Half Life ◽  
Degradation Kinetics ◽  
Production Method ◽  
Order Reaction ◽  
Different Temperatures ◽  
Traditional Production ◽  
Effects Of Temperature ◽  
Kinetics Of

This research was performed to elucidate the effects of temperature on the degradation kinetics of anthocyanins in shalgam beverage. Shalgam beverage was produced according to traditional production method. Then, it was kept at three different temperatures (65°C, 75°C, and 85°C) for 12 hours, and the relevant quantities of anthocyanins were determined thereafter. The research revealed that degradation of the anthocyanins was well described with a 1st-order reaction kinetics model and the R2 values varied in the range of 0.9059-0.9715. Activation energy of the reaction was determined to be 48537 Joule/mole. The half-lives of anthocyanins at 65°C and 75° C, and 85°C were found to be 138.63, 136.72, and 51.57, respectively. Compared the half-life periods at different temperatures, anthocyanins were found to be more resistant at 65°C and 75°C than at 85°C.

scholarly journals Kinetics of Human Immunodeficiency Virus Type 1 Decay following Entry into Resting CD4+ T Cells

2005 ◽  
Vol 79 (4) ◽  
pp. 2199-2210 ◽  
Author(s):  
Yan Zhou ◽  
Haili Zhang ◽  
Janet D. Siliciano ◽  
Robert F. Siliciano
Keyword(s):  
Gene Expression ◽  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Reverse Transcription ◽  
Half Life ◽  
Immunodeficiency Virus ◽  
Kinetics Of ◽  
Hiv 1

ABSTRACT In untreated human immunodeficiency virus type 1 (HIV-1) infection, most viral genomes in resting CD4+ T cells are not integrated into host chromosomes. This unintegrated virus provides an inducible latent reservoir because cellular activation permits integration, virus gene expression, and virus production. It remains controversial whether HIV-1 is stable in this preintegration state. Here, we monitored the fate of HIV-1 in resting CD4+ cells by using a green fluorescent protein (GFP) reporter virus carrying an X4 envelope. After virus entry into resting CD4+ T cells, both rescuable virus gene expression, visualized with GFP, and rescuable virion production, assessed by p24 release, decayed with a half-life of 2 days. In these cells, reverse transcription goes to completion over 2 to 3 days, and 50% of the viruses that have entered undergo functional decay before reverse transcription is complete. We distinguished two distinct but closely related factors contributing to loss of rescuable virus. First, some host cells undergo virus-induced apoptosis upon viral entry, thereby reducing the amount of rescuable virus. Second, decay processes directly affecting the virus both before and after the completion of reverse transcription contribute to the loss of rescuable virus. The functional half-life of full-length, integration-competent reverse transcripts is only 1 day. We propose that rapid intracellular decay processes compete with early steps in viral replication in infected CD4+ T cells. Decay processes dominate in resting CD4+ T cells as a result of the slow kinetics of reverse transcription and blocks at subsequent steps. Therefore, the reservoir of unintegrated HIV-1 in recently infected resting CD4+ T cells is highly labile.

Effect of Endotoxin on Kinetics of Antithrombin III

1979 ◽  
Author(s):  
H. Tanaka ◽  
N. Kobayashi ◽  
T. Takeuchi ◽  
M. Takada ◽  
T. Haekawa
Keyword(s):  
Half Life ◽  
Antithrombin Iii ◽  
Coagulation Factors ◽  
Synthesis Rate ◽  
Blood Samples ◽  
At Iii ◽  
Kinetics Of ◽  
Plasma Half Life

The kinetics of antithrombin III(AT III) in dogs were studied using I-125-labelled AT III and Se-75-methionine. As reported at the last meeting of ISH, the plasma half-life of AT III was 1.7±0.2 days in normal 5 control dogs. The double i.v. administration of 200 ug/ltg of endotoxin and the single i.v. administration of 1 mg/kg of endotoxin resulted in 30% decrease of plasma AT III, 60% decrease of coagulation Factors (I, II, V, VII, VIII, IX), the shortening of plasma half-life of AT III to 1.4 days and the increase of J3u values, suggesting increase of the synthesis rate of AT III. Then, the synthesis of AT III was studied directly using Se-75-methionine. After i.v. injection of Se-75-methionine, blood samples were obtained. One ml of sample plasma was incubated for 24 hrs with 1 ml of anti-AT III antiserum, which was produied in rabbits and the radioactivity of the precipitates were determined. About 80% of AT III was recovered in the precipitates by this method. The maximum radioactivity was obtained 18 hrs after injection of Se-75-methionine, and 0.27 % of total injected Se-75-methionine were utilized to the production of AT III.These results indicates that; 1. Endotoxin accelerates the metabolism of AT III. 2. The analysis of AT III production is possible using Se-75-methionine as a tracer.

scholarly journals A fluorescent residualizing label for studies on protein uptake and catabolism in vivo and in vitro

1990 ◽  
Vol 267 (1) ◽  
pp. 155-162 ◽  
Author(s):  
J L Maxwell ◽  
L Terracio ◽  
T K Borg ◽  
J W Baynes ◽  
S R Thorpe
Keyword(s):  
Half Life ◽  
Normal Tissue ◽  
Degradation Products ◽  
Rat Serum ◽  
Peripheral Tissues ◽  
Protein Uptake ◽  
Kinetics Of ◽  
Rat Serum Albumin

Residualizing labels are tracers which remain in lysosomes after uptake and catabolism of the carrier protein and have been especially useful for studies on the sites of plasma protein degradation. Thus far these labels have contained radioactive reporters such as 3H or 125I. In the present paper we describe a fluorescent residualizing label, NN-dilactitol-N′-fluoresceinylethylenediamine (DLF). Modification of asialofetuin (ASF) or rat serum albumin (RSA) with DLF affected neither their normal kinetics of clearance from the rat circulation nor their normal tissue sites of uptake and degradation. After injection of DLF-ASF, fluorescent degradation products were recovered nearly quantitatively in liver and retained with a half-life of about 2 days. Fluorescent degradation products from DLF-RSA were recovered in skin and muscle, and were localized in fibroblasts by fluorescence microscopy. These results confirm previous studies with radioactive residualizing labels in which fibroblasts in peripheral tissues were identified as primary sites of albumin degradation. Fluorescent catabolites also accumulated in fibroblasts incubated with DLF-RSA in vitro, and residualized with a half-life of about 2 days. Overall, the data establish that DLF functions efficiently as a fluorescent residualizing label both in vivo and in vitro. The advantages of fluorescent, compared with radioactive, residualizing labels should make them valuable tools for studies on protein uptake and catabolism in biological systems.

scholarly journals Inhibition by insulin of the formation of autophagic vacuoles in rat liver. A morphometric approach to the kinetics of intracellular degradation by autophagy.

1978 ◽  
Vol 78 (1) ◽  
pp. 152-167 ◽  
Author(s):  
U Pfeifer
Keyword(s):  
Half Life ◽  
Intraperitoneal Administration ◽  
Male Rats ◽  
Electron Microscopic ◽  
Autophagic Vacuoles ◽  
Intracellular Degradation ◽  
First Order Kinetics ◽  
Different Types ◽  
Electron Microscopic Morphometry ◽  
Kinetics Of

Electron microscopic morphometry has demonstrated a rapid decrease in the fractional volume of autophagic vacuoles (AV) in hepatocytes of adult male rats after the intraperitoneal administration of insulin (5 U/kg of body weight). Except for a significant decrease in glycogen to about one-half its initial value, no major changes in the composition of the remaining cytoplasm, or in the average volume of the single hepatocyte, were seen. The decrease found in the AVs is attributed to an inhibition of the formation of new AVs-probably the morphologic counterpart of the well-known anticatabolic effects of insulin. The decay of the fractional volume of the AVs appeared to follow first-order kinetics. Thus, the termination of the "life" of an AV by destruction of its contents may not depend directly on the "age" of the AV. The average half-life of the AVs amounted to approximately 9 min. Similar values were found for the different types of AVs, except for those containing glycogen. The half-life of these AVs was approximately 18 min. From the half-life values and from the "segregated fractions" at time zero, which were different for the different cytoplasmic components, rates of removal from the cytoplasm by autophagy were calculated. Expressed as "percent per day", the following rates were found: whole cytoplasm, 2.3; mitochondria, 3.9; microbodies, 8.9; and glycogen, 1.1. The results indicate that autophagy, to some extent, is selective and plays an important, but not an exclusive, role in intracellular turnover.

scholarly journals Oestrogen-induced synthesis of thiamin-binding protein in immature chicks. Kinetics of induction, hormonal specificity and modulation

1980 ◽  
Vol 186 (1) ◽  
pp. 201-210 ◽  
Author(s):  
Kalappagowda Muniyappa ◽  
P. Radhakantha Adiga
Keyword(s):  
Half Life ◽  
Binding Proteins ◽  
Binding Protein ◽  
Steroid Hormone ◽  
Plasma Concentrations ◽  
Protein A ◽  
Specific Protein ◽  
Clear Cut ◽  
Apparent Similarity ◽  
Kinetics Of

A specific radioimmunoassay procedure was developed to monitor the plasma concentrations of thiamin-binding protein, a minor yolk constituent of the chicken egg. By using this sensitive assay, the kinetics of oestrogen-induced elaboration of this specific protein in immature chicks was investigated. After a single injection of the steroid hormone, with an initial lag period of 4–5h the thiamin-binding protein rapidly accumulated in the plasma, attaining peak concentrations around 75h and declining thereafter. A 4-fold amplification of the response was noticed during the secondary stimulation, and this increased to 9-fold during the tertiary stimulation with the steroid hormone. The magnitude of the response was dependent on the hormone dose, and the initial latent period and the duration of the ascending phase of induction were unchanged for the hormonal doses tested during both the primary and secondary stimulations. The circulatory half-life of the protein was 6h as calculated from the measurement of the rate of disappearance of the exogenously administered 125I-labelled protein. Simultaneous administration of progesterone, dihydrotestosterone or corticosterone did not alter the pattern of induction. On the other hand, hyperthyroidism markedly decreased the oestrogenic response, whereas propylthiouracil-induced hypothyroidism had the opposite effect. The anti-oestrogen E- and Z-clomiphene citrates, administered 30min before oestrogen, effectively blocked the hormonal induction. α-Amanitin and cycloheximide administered along with or shortly after the sex steroid severely curtailed the protein elaboration. A comparison of the kinetics of induction of thiamin- and riboflavin-binding proteins by oestrogen revealed that, beneath an apparent similarity, a clear-cut difference exists between the two vitamin-binding proteins, particularly with regard to hormonal dose-dependent sensitivity of induction and the half-life in circulation. The steroid-mediated elaboration of the two yolk proteins thus appears to be not strictly co-ordinated, despite several common regulatory features underlying their induction.

scholarly journals Anthocyanin kinetics are dependent on anthocyanin structure

2011 ◽  
Vol 107 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Janet A. Novotny ◽  
Beverly A. Clevidence ◽  
Anne C. Kurilich
Keyword(s):  
Half Life ◽  
Gastrointestinal Transit ◽  
Crossover Design ◽  
Human Beings ◽  
Feeding Trial ◽  
Compartmental Modelling ◽  
Acylated Anthocyanins ◽  
Blood And Urine Samples ◽  
Time Courses ◽  
Kinetics Of

The kinetics of anthocyanin metabolism was investigated in a human feeding trial. Volunteers (n 12) consumed purple carrots containing five anthocyanin forms: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside), cyanidin-3-(xylose-feruloyl-glucose-galactoside) and cyanidin-3-(xylose-coumuroyl-glucose-galactoside). The purple carrots were served as three different treatments in a crossover design with a 3-week washout between treatments. Purple carrot treatments were 250 g raw carrots, 250 g cooked carrots and 500 g cooked carrots. Serial blood and urine samples were collected for 8 and 24 h after the dose, respectively, and analysed for anthocyanins. Of the anthocyanin forms ingested, four were detected in plasma and urine: cyanidin-3-(xylose-glucose-galactoside), cyanidin-3-(xylose-galactoside), cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside). The time courses of plasma and urine anthocyanin contents were evaluated with compartmental modelling. Results showed that absorption, gastrointestinal transit and plasma elimination are dependent on anthocyanin structure. Absorption efficiencies of acylated compounds (cyanidin-3-(xylose-sinapoyl-glucose-galactoside) and cyanidin-3-(xylose-feruloyl-glucose-galactoside)) were less than those for non-acylated anthocyanins (cyanidin-3-(xylose-glucose-galactoside) and cyanidin-3-(xylose-galactoside)). The acylated anthocyanins exhibited a shorter half-life for gastrointestinal absorption than the non-acylated anthocyanins. Fractional elimination of non-acylated compounds was slower than that for acylated anthocyanins. These results provide the first information about the kinetics of individual anthocyanins in human beings.

Single Dose Pharmacokinetic Study of Lithium in Taiwanese/Chinese Bipolar Patients

1998 ◽  
Vol 32 (1) ◽  
pp. 133-136 ◽  
Author(s):  
Ching-Fa Lee ◽  
Yong-Yi Yang ◽  
Oliver Yoa-Pu Hu
Keyword(s):  
Single Dose ◽  
Racial Differences ◽  
Half Life ◽  
Lithium Carbonate ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Overnight Fasting ◽  
Ethnic Comparisons ◽  
Bipolar Patients ◽  
Kinetics Of

Objective: The purpose of this study is to investigate the single dose pharmaco-kinetics of lithium in Taiwanese/Chinese bipolar patients for future interracial comparisons. Method: Eight bipolar patients took 900 mg of lithium carbonate after overnight fasting. Blood samples of 5 mL were taken after 15 min, 30 min, 45 min, 1 h, 2 h, 3 h, 4 h, 7 h, 9 h, 15 h, 25 h and 31 h after dosing. The computer programs CSTRIP and PCNONLIN were used for pharmacokinetic analysis. Results: The pharmacokinetic parameters obtained were as follows: Cmax, 0.970 ± 0.170 (SD) mmoi/L; Tmax, 1.59 ± 0.78 h; AUC31h = 548.9 ± 135.4 mmol.m/L; AUC = 722.6 ± 262.7 mmol.m/L; β-half-life = 16.3 ± 7.18 h; K-half-life = 0.613 ± 0.442 h; CIoral = 1.13 ± 0.39 mL/min/kg; Vd/F = 1.43 ± 0.387 L/kg. Most of the pharmacokinetic parameters were within the ranges reported in investigations of Caucasian subjects. Conclusions: This study showed that racial differences in lithium pharmacokinetics might not exist. We suggest that methodological designs, including method of blood sampling, measurement of lithium, and pharmacokinetic and statistical calculations, be standardised if future cross-ethnic comparisons are to be conducted.

Sign in / Sign up

Export Citation Format

Share Document