Kinetics of Blood to Cell Uptake of Radiotracers*

2020 ◽  
pp. 97-146
Author(s):  
James B. Bassingthwaighte ◽  
Bernd Winkle
Keyword(s):  
Cell Uptake ◽  
Kinetics Of

TRIIODOTHYRONINE METABOLISM IN DIABETIC RATS

1978 ◽  
Vol 89 (2) ◽  
pp. 323-328 ◽  
Author(s):  
R. Boado ◽  
T. J. Brown ◽  
N. R. Bromage ◽  
A. J. Matty ◽  
A. A. Zaninovich
Keyword(s):  
Diabetic Rats ◽  
Cell Uptake ◽  
Male Rats ◽  
Control Group ◽  
Wistar Strain ◽  
Straight Line ◽  
Induced Changes ◽  
Binding Avidity ◽  
Kinetics Of ◽  
Uptake Method

ABSTRACT Triiodothyronine (T3) metabolism was assessed in untreated and in insulin-treated diabetic rats and the results compared with a corresponding control group. Male rats of the Wistar strain were made diabetic by the intraperitoneal injection of alloxan in a dose of 17.5 mg/100 g body weight and thereafter maintained normoglycaemic for a week and until 24 h before initiation of the study. The average glycaemia in control and in insulin-treated animals was 135 mg/100 ml, whereas in the untreated diabetic rats it was 455 mg/100 ml. Each animal was injected a tracer dose of [125I]T3 containing 2 μCi of 125I and 15 ng of T3. Heparinized blood samples were obtained by cardiac puncture at 5, 18 and 24 h following the injection of the tracer. The excretion of inorganic 125I in the 24-h collections of urine was also determined. The kinetics of [125I]T3 were studied by the extrapolation method using the straight line of plasma disappearance between 5 and 24 h. It was found that the untreated diabetic rats had a significant slowing of plasma disappearance of labelled T3. The decrease in fractional hormone turnover was balanced by a slight expansion of the distribution space, which presumably led to a larger hormone pool and a normal degradation rate of T3. These events seemed substantiated by the normal excretion of 125I in the urine observed in untreated animals. A parallel study of plasma hormone binding using a red cell uptake method showed a significant reduction of binding avidity for T3 by plasma proteins in the untreated diabetic animals. The administration of insulin restored plasma T3 kinetics and binding avidity to normal, as observed in control rats. It was concluded that untreated diabetes mellitus induced changes in T3 kinetics and in T3 serum binding without altering hormone deiodination, parameter which reflects tissue utilization of T3.

scholarly journals Analysis of Adenovirus Sequestration in the Liver, Transduction of Hepatic Cells, and Innate Toxicity after Injection of Fiber-Modified Vectors

2004 ◽  
Vol 78 (10) ◽  
pp. 5368-5381 ◽  
Author(s):  
Dmitry M. Shayakhmetov ◽  
Zong-Yi Li ◽  
Shaoheng Ni ◽  
André Lieber
Keyword(s):  
Intravenous Injection ◽  
Liver Damage ◽  
Kupffer Cells ◽  
Liver Cell ◽  
Liver Tissue ◽  
Cell Uptake ◽  
Liver Uptake ◽  
Hepatic Cells ◽  
Kinetics Of ◽  
Over Time

ABSTRACT After intravenous administration, adenovirus (Ad) vectors are predominantly sequestered by the liver. Delineating the mechanisms for Ad accumulation in the liver is crucial for a better understanding of Ad clearance and Ad-associated innate toxicity. To help address these issues, in this study, we used Ad vectors with different fiber shaft lengths and either coxsackievirus-Ad receptor (CAR)-interacting Ad serotype 9 (Ad9) or non-CAR-interacting Ad35 fiber knob domains. We analyzed the kinetics of Ad vector accumulation in the liver, uptake into hepatocytes and Kupffer cells, and induction of cytokine expression and release in response to systemic vector application. Immediately after intravenous injection, all Ad vectors accumulated equally efficiently in the liver; however, only genomes of long-shafted Ads were maintained in the liver tissue over time. We found that Kupffer cell uptake of long-shafted Ads was mediated by the fiber knob domain and was CAR independent. The short-shafted Ads were unable to efficiently interact with hepatocellular receptors and were not taken up by Kupffer cells. Moreover, our studies indicated that Kupffer cells were not the major reservoir for the observed accumulation of Ads (used in this study) in the liver within the first 30 min after virus infusion. The lower level of liver cell transduction by short-shafted Ads correlated with a significantly reduced inflammatory anti-Ad response as well as liver damage induced by the systemic administration of these vectors. This study contributes to a better understanding of the biology of systemically applied Ad and will help in designing safer vectors that can efficiently transduce target tissues.

scholarly journals Assessment of Intratumoral Doxorubicin Penetration after Mild Hyperthermia-Mediated Release from Thermosensitive Liposomes

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Marc Derieppe ◽  
Jean-Michel Escoffre ◽  
Baudouin Denis de Senneville ◽  
Quincy van Houtum ◽  
Angelique Barten-van Rijbroek ◽  
...  
Keyword(s):  
Real Time ◽  
Anticancer Agents ◽  
Cell Uptake ◽  
Fluorescence Labeling ◽  
Cell Nuclei ◽  
Uptake Rates ◽  
Thermosensitive Liposomes ◽  
Kinetics Of ◽  
Drug Nanocarriers ◽  
Vascular Compartment

In solid tumors, rapid local intravascular release of anticancer agents, e.g., doxorubicin (DOX), from thermosensitive liposomes (TSLs) can be an option to overcome poor extravasation of drug nanocarriers. The driving force of DOX penetration is the drug concentration gradient between the vascular compartment and the tumor interstitium. In this feasibility study, we used fibered confocal fluorescence microscopy (FCFM) to monitor in real-time DOX penetration in the interstitium of a subcutaneous tumor after its intravascular release from TSLs, Thermodox®. Cell uptake kinetics of the released DOX was quantified, along with an in-depth assessment of released-DOX penetration using an evolution model. A subcutaneous rat R1 rhabdomyosarcoma xenograft was used. The rodent was positioned in a setup including a water bath, and FCFM identification of functional vessels in the tumor tissue was applied based on AngioSense. The tumor-bearing leg was immersed in the 43°C water for preheating, and TSLs were injected intravenously. Real-time monitoring of intratumoral (i.t.) DOX penetration could be performed, and it showed the progressing DOX wave front via its native fluorescence, labeling successively all cell nuclei. Cell uptake rates (1/k) of 3 minutes were found (n=241  cells), and a released-DOX penetration in the range of 2500 µm2·s−1 was found in the tumor extravascular space. This study also showed that not all vessels, identified as functional based on AngioSense, gave rise to local DOX penetration.

18F-FLT and 125I-IdUrd uptake increase in human tumour cell lines induced by the thymidylate synthase inhibitor FdUrd

2012 ◽  
Vol 51 (05) ◽  
pp. 163-169
Author(s):  
D. Viertl ◽  
F. Perillo-Adamer ◽  
P.-A. André ◽  
S. M. Ametamey ◽  
T. L. Ross ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Uptake ◽  
Human Breast ◽  
Salvage Pathway ◽  
Parallel Methods ◽  
Excess Thymidine ◽  
Tumour Cell Lines ◽  
Synthase Inhibitor ◽  
Kinetics Of ◽  
Human Tumour Cell Lines

Summary Aim: 5-fluoro-2′-deoxyuridine (FdUrd) depletes the endogenous 5′-deoxythymidine triphosphate (dTTP) pool. We hypothesized whether uptake of exogenous dThd analogues could be favoured through a feedback enhanced salvage pathway and studied the FdUrd effect on cellular uptake of 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) and 5-125I-iodo-2′-deoxyuridine (125I-IdUrd) in different cancer cell lines in parallel. Methods: Cell uptake of 18F-FLT and 125I-IdUrd was studied in 2 human breast, 2 colon cancer and 2 glioblastoma lines. Cells were incubated with/without 1 μmol/l FdUrd for 1 h and, after washing, with 1.2 MBq 18F-FLT or 125I-IdUrd for 0.3 to 2 h. Cell bound 18F-FLT and 125I-IdUrd was counted and expressed in % incubated activity (%IA). Kinetics of 18F-FLT cell uptake and release were studied with/without FdUrd modulation. 2′-3H-methyl-fluorothymidine (2′-3H-FLT) uptake with/without FdUrd pretreatment was tested on U87 spheroids and monolayer cells. Results: Basal uptake at 2 h of 18F-FLT and 125I-IdUrd was in the range of 0.8–1.0 and 0.4–0.6 Bq/cell, respectively. FdUrd pretreatment enhanced 18F-FLT and 125I-IdUrd uptake 1.2–2.1 and 1.7–4.4 fold, respectively, while co-incubation with excess thymidine abrogated all 18F-FLT uptake. FdUrd enhanced 18F-FLT cellular inflow in 2 breast cancer lines by factors of 1.8 and 1.6, respectively, while outflow persisted at a slightly lower rate. 2′-3H-FLT basal uptake was very low while uptake increase after FdUrd was similar in U87 monolayer cells and spheroids. Conclusions: Basal uptake of 18F-FLT was frequently higher than that of 125I-IdUrd but FdUrd induced uptake enhancement was stronger for 125I-IdUrd in five of six cell lines. 18F-FLT outflow from cells might be an explanation for the observed difference with 125I-IdUrd.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Ion Beam Induced Interfacial Reactions in Molybdenum Thin Films on Silicon

1981 ◽  
Vol 39 ◽  
pp. 162-163
Author(s):  
L. J. Chen ◽  
L. S. Hung ◽  
J. W. Mayer
Keyword(s):  
Ion Beam ◽  
Chemical Vapor ◽  
Interfacial Reactions ◽  
Practical Applications ◽  
Microelectronic Devices ◽  
Recent Emergence ◽  
Chemical Vapor Deposited ◽  
Atomic Mixing ◽  
Silicon Interface ◽  
Kinetics Of

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

Investigation of irradiation-induced nucleation processes in silicon and germanium

1995 ◽  
Vol 53 ◽  
pp. 224-225
Author(s):  
Harry A. Atwater ◽  
C.M. Yang ◽  
K.V. Shcheglov
Keyword(s):  
Room Temperature ◽  
Crystal Size ◽  
Initial Distribution ◽  
Engineering Control ◽  
Size Evolution ◽  
Silicon And Germanium ◽  
Ge Quantum Dot ◽  
And Control ◽  
Germanium Quantum Dots ◽  
Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

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