ABSTRACT The ositron emitted (Em 635 Key) upon radioactive decay of 8F has been used to measure 1... more ABSTRACT The ositron emitted (Em 635 Key) upon radioactive decay of 8F has been used to measure 18F in liquid scintillator solutions which have low or high water capacity, and in hydrophilic and hydrophobic liquids which have dif-ferent refractive indicies. The influence of nitromethane, a chemical quenching agent, on counting efficiency in each of these liquids has been measured, and is discussed on the basis of observed shifts in the pulse height spectra. The contribution of coincident Compton events arising from the annihilation gamma rays, to the overall counting efficiency, has been estimated using methyl salicylate as the counting medium.
Summary: OVAREXTM MAb B43. 13 is a new radiopharmaceutical based on a monoclonal antibody (MAb-B4... more Summary: OVAREXTM MAb B43. 13 is a new radiopharmaceutical based on a monoclonal antibody (MAb-B43. 13) known to recognize CA 125, a tumour antigen associated with epithelial ovarian cancer. This MAb is capable of facile radiolabelling with 99Tcm and has ...
We have previously reported the polyamine uptake kinetics in various prostate and non-prostate ca... more We have previously reported the polyamine uptake kinetics in various prostate and non-prostate cancer cell lines, concluding that the prostate cancer cell lines took up and accumulated polyamines at higher levels than non-prostate cell lines, with a view to their use as PET agents. The objective of the present study was to assess their in vivo accumulation in a rat prostate tumor model. A comparative biodistribution study of the polyamines was conducted in AT3B-1 prostate tumors in male Copenhagen rats to determine which of the polyamines show preferential accumulation in the tumor. Tissue samples were collected one hour post administration of the polyamines (i.v.), and the radioactivity of the samples was measured by first combusting the tissue samples in a biological oxidizer and then assaying the trapped 14CO2 in a liquid scintillation counter. Putrescine exhibited the highest tumor accumulation followed by ornithine (4.1% and 1.8% of injected dose/g of the tumor respectively). T...
The Km and Vmax of [14C]-radiolabeled polyamines were determined for PC-3 and AT3B-1 cell lines. ... more The Km and Vmax of [14C]-radiolabeled polyamines were determined for PC-3 and AT3B-1 cell lines. With PC-3 Km values are in the following order: ornithine> spermidine> spermine> putrescine, while with AT3B-1 it was spermidine> ornithine> spermine> putrescine. To determine which of these polyamines exhibit higher accumulation, the relative uptake of all the four amines was studied with prostate (PC-3, AT3B-1, LNCaP) and non-prostate (MCF-7, KLN-205, OVCAR) cell lines at 10 and 20 microM after 1 hour. Spermine and spermidine accumulated at higher levels in prostate (AT3B-1 and LNCaP) over non-prostate cell lines (p < 0.01). Putrescine accumulated more in PC-3 and LNCaP than the non-prostate cancer cells.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010
Although the conventional stacked foil technique is the common method for evaluating experimental... more Although the conventional stacked foil technique is the common method for evaluating experimental cross sections of deuteron induced reactions on titanium, this work employed a single foil irradiation strategy. This strategy was selected for the purpose of improving the counting statistics for the reactions with low activation probabilities as it allowed for activity assay times comparable to the half-life of
ABSTRACT The radionuclide 41Ar has many ideal properties as a gas flow tracer. However, the modes... more ABSTRACT The radionuclide 41Ar has many ideal properties as a gas flow tracer. However, the modest cross-section of 40Ar for thermal neutron activation makes preparation of suitable activities of 41Ar technically difficult particularly for low flux reactors. Argon can however be trapped in a molecular complex called a clathrate that can then be irradiated. We prepared argon clathrate and explored its irradiation and stability characteristics. Argon clathrate can be used to provide gigabecquerel quantities of 41Ar even with low power reactors.
Journal of nuclear biology and medicine (Turin, Italy : 1991), 1994
The monoclonal antibody (MoAb) 174H.64 (Truscint SQ, Biomira Inc.) is a murine-derived MoAb react... more The monoclonal antibody (MoAb) 174H.64 (Truscint SQ, Biomira Inc.) is a murine-derived MoAb reacting with an extracellular surface component of the cytoskeletal matrix ectopically expressed on squamous-cell carcinoma cell-surface membranes. A chimeric form of this MoAb has also been produced by genetically modifying the Fc portion of the MoAb by the insertion of a human Fc fragment. During this process the isotype was altered from an IgG1 (murine) to an IgG3 (chimeric). Pilot and phase I/II clinical trials of the murine and chimeric 99mTc-labelled 174H.64 MoAbs have been undertaken at selected European and North American sites. As part of this evaluation serum, urine and image data were collected at specific time intervals and used to obtain a kinetic model to describe the in vivo distribution of the MoAbs. A two-compartment model of the form: C(t) = C1 e-lambda 1t + Cz e-lambda zt was found to best describe the serum distribution of radioactivity of both the murine and chimeric MoA...
This review gives a survey on the use and applications of technetium-94m ((94m)Tc) as a non-conve... more This review gives a survey on the use and applications of technetium-94m ((94m)Tc) as a non-conventional positron emission tomography (PET) radionuclide for molecular imaging. The first part of this review describes the production and processing of (94m)Tc. The second part covers basic concepts of technetium coordination chemistry with a special focus on the synthesis of (94m)Tc-labeled compounds for molecular imaging purposes. The review concludes with a summary and an outlook on the prospects of using (94m)Tc in the field of PET chemistry and molecular imaging.
Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques, 2006
PURPOSE To establish a matrix of parameters to synthesize nanoparticles of different sizes and to... more PURPOSE To establish a matrix of parameters to synthesize nanoparticles of different sizes and to investigate the cellular uptake of these nanoparticles by osteosarcoma cancer cells in order to investigate their potential as therapeutic drugdelivery carriers. METHODS Gelatin A and B were used to synthesize nanoparticles by a two-step desolvation process. Different parameters were investigated, including temperature, pH, concentration of glutaraldehyde, type of desolvating agent and nature of gelatin. For cell uptake studies, Texas Red labeled nanoparticles were incubated with 143B osteosarcoma cells and then evaluated using confocal laser scanning microscopy (CLSM). RESULTS The systematic investigation of the synthesis parameters showed that it is possible to prepare gelatin-based nanoparticles with different particle sizes and a narrow size distribution. Temperature and nature of the gelatin were the most important synthesis factors. Bioimaging using CLSM showed uptake of the nanop...
e13529 Background: Nab-paclitaxel (NP) is a solvent-free, albumin-bound nanoparticle formulation;... more e13529 Background: Nab-paclitaxel (NP) is a solvent-free, albumin-bound nanoparticle formulation; it binds to albumin receptor on endothelial cells, which in turn activates caveolin-1. Lack of solvents and receptor-mediated delivery results in decreased toxicity and increased antitumor activity of NP. Tumors expressing SPARC, and albumin-binding protein may have increased efficacy of NP. In this study we evaluated paclitaxel (P) and NP toxicities; SPARC's role in NP sensitivity; intraperitoneal NP effect and maximum tolerated dose (MTD) in mice with ovarian cancer. METHODS Human ovarian cancer (OC) cell lines OVCAR-3, SKOV-3, AG-6000 and A-2780 were seeded in 96-well plates and after 24 hours (h) of seeding, varying concentrations of NP or P were added for 72 h, after which viability was evaluated by MTS assay. SPARC expression was determined in all 4 OC lines by Western blotting. In an in vivo study, intraperitoneal injections of NP were evaluated at different doses (50, 75, 100, and 125mg/Kg) on growth of tumors in mice with OC. RESULTS Mean IC50 (concentration of drug that inhibits 50% of cell growth) for A-2780 cell line treated with P vs. NP was 16.2 vs. 0.12 nM respectively (fold difference 131); for AG-6000 was 19 vs. 0.15 nM respectively (fold difference 124); for OVCAR-3 was 2.04 vs. 1.77 nM respectively (fold difference 1.15); and for SKOV-3 was 9.5 vs. 9.04 nM (fold difference 1.05). SPARC protein was present in cells (AG-6000 and A-2780) that were more sensitive to NP but not in OVCAR-3 and SKOV-3 cell lines. All NP doses were well tolerated in mice with OC and no significant difference in post treatment recovery was noted. All mice had reduced activity and squinting for 1-1.5 hours post NP injection; and they all seemed anemic at the necroscopy. CONCLUSIONS NP had higher cytotoxic effects compared to P in AG-6000 and A-2780 cell lines which directly correlated with higher SPARC expression in these two 2 cell lines. Intraperitoneal NP was well tolerated in an OC mouse model.
This paper discusses the production methods of the most commonly used non-standard PET radionucli... more This paper discusses the production methods of the most commonly used non-standard PET radionuclides, their decay characteristics and importance in the development of novel radiopharmaceuticals for PET-based molecular imaging and potential applications in therapy.
To compare the radiation dose to normal organs from the radio-iodinated, hypoxia-binding radiosen... more To compare the radiation dose to normal organs from the radio-iodinated, hypoxia-binding radiosensitizer iodoazomycin arabinoside (IAZA) for three different isotopes of iodine. Dosimety studies with normal volunteers had been carried out with [(123) I]IAZA, a drug binding selectively to hypoxic sites. Two other isotopes of iodine, (131) I and (124) I, offer the opportunity to use IAZA as an agent for radioisotope therapy and as an imaging tracer for Positron Emission Tomography. Radioisotope dosimetry for (131) I and (124) I was performed by first deriving from the [(123) I]IAZA studies biological uptake and excretion data. The cumulated activities for (131) I or (124) I where obtained by including their half-lives when integrating the biological data and then extrapolating to infinite time points considering a) physical decay only or b) physical and biological excretion. Doses were calculated using the Medical Internal Radiation Dose (MIRD) schema (OLINDA1.1 code, Vanderbilt 2007). Compared to (123) I, organ doses were elevated on average by a factor 6 and 9 for (131) I and (124) I, respectively, if both physical decay and biological excretion were modeled. If only physical decay is considered, doses increase by a factor 18 ((131) I) and 19 ((124) I). Highest organ doses were observed in intestinal walls, urinary bladder and thyroid. Effective doses increased by a factor 11 and 14 for (131) I and (124) I, respectively, if biological and physical decay are present. Purely physical decay yields a 23-fold increase over (123) I for both, (131) I and (124) I. Owing to the significant dose increase, caused by their longer half life and the approximately 10 times larger electronic dose deposited in tissue per nuclear decay, normal tissue doses of IAZA labeled with (131) I and (124) I need to be carefully considered when designing imaging and therapy protocols for clinical trials. Effective blocking of iodine uptake in the thyroid is essential. Alberta Innovates - Health Solutions (AIHS) and Canadian Institutes of Health Research (CIHR).
The International Journal of Applied Radiation and Isotopes, 1980
The additional scintillation intensity generated as a result of annihilation radiation causes the... more The additional scintillation intensity generated as a result of annihilation radiation causes the pulse height spec18 + trum of Fluorine (635 Key max) to be broader than might be expected in comparison with 36Chlorinc (714 Key nax) The spectrum due only to the annihilation radiation was compared to the complete 18Fluorine spectrum using an aluminum absorber. Measurements made with and without this absorber indicated that the annihilation radiation alone may be detected with an efficiency of approximately 24% compared to that without the absorber. The logarithmic response of the detection system was calibrated in terms of energy to facilitate spectral comparisons.
The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of Radiopharmaceutical Chemistry and Biology, 2008
Pharmacokinetic models play a crucial role in analyzing and assessing the results of in vitro and... more Pharmacokinetic models play a crucial role in analyzing and assessing the results of in vitro and in vivo studies. In this review, comparative analysis of pharmacokinetic models under homogeneous and heterogeneous conditions is performed, placing special focus on the role of fractal theory. The concept of fractals provides a new perspective from which processes occurring in heterogeneous, confined, or poorly mixed environments can be modeled. Following a brief theoretical overview, the applicability of fractals in characterizing anatomical structures and physiological processes as well as the transport and reaction of drugs within the body is discussed. There is significant evidence that drug absorption, distribution, metabolism, and excretion are often anomalous, that is to say their behavior deviates from classical theory, and possible reasons and appropriate models are considered.
The quarterly journal of nuclear medicine : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), 2001
A review of published data on some of the problems associated in treating cancer using radioimmun... more A review of published data on some of the problems associated in treating cancer using radioimmunotherapy is presented. Potential improvements for this type of therapy using pretargeting strategies are discussed and preliminary results on a novel multistep regimen to treat human ovarian cancer are presented. A pretargeting strategy using a biotinylated, anti-CA125 monoclonal antibody (MAb) to attract biotinylated long-circulating liposomes to the surface of CA125-expressing ovarian cancer cells, was employed. Confocal laser scanning microscopy and fluorescent labels were used to establish the biodistribution patterns in NIH:OVCAR-3 (CA-125 positive) and SK-OV-3 (CA-125 negative) human ovarian cancer cells. Shedding kinetics of the pretargeted stage were measured using 125I labeled MAbs. No significant internalization of the MAb used in the pretargeting step was observed by 4 hrs. The antibody was gradually internalized starting at 6 hrs, and most of the labelled MAb was detected in ...
ABSTRACT The ositron emitted (Em 635 Key) upon radioactive decay of 8F has been used to measure 1... more ABSTRACT The ositron emitted (Em 635 Key) upon radioactive decay of 8F has been used to measure 18F in liquid scintillator solutions which have low or high water capacity, and in hydrophilic and hydrophobic liquids which have dif-ferent refractive indicies. The influence of nitromethane, a chemical quenching agent, on counting efficiency in each of these liquids has been measured, and is discussed on the basis of observed shifts in the pulse height spectra. The contribution of coincident Compton events arising from the annihilation gamma rays, to the overall counting efficiency, has been estimated using methyl salicylate as the counting medium.
Summary: OVAREXTM MAb B43. 13 is a new radiopharmaceutical based on a monoclonal antibody (MAb-B4... more Summary: OVAREXTM MAb B43. 13 is a new radiopharmaceutical based on a monoclonal antibody (MAb-B43. 13) known to recognize CA 125, a tumour antigen associated with epithelial ovarian cancer. This MAb is capable of facile radiolabelling with 99Tcm and has ...
We have previously reported the polyamine uptake kinetics in various prostate and non-prostate ca... more We have previously reported the polyamine uptake kinetics in various prostate and non-prostate cancer cell lines, concluding that the prostate cancer cell lines took up and accumulated polyamines at higher levels than non-prostate cell lines, with a view to their use as PET agents. The objective of the present study was to assess their in vivo accumulation in a rat prostate tumor model. A comparative biodistribution study of the polyamines was conducted in AT3B-1 prostate tumors in male Copenhagen rats to determine which of the polyamines show preferential accumulation in the tumor. Tissue samples were collected one hour post administration of the polyamines (i.v.), and the radioactivity of the samples was measured by first combusting the tissue samples in a biological oxidizer and then assaying the trapped 14CO2 in a liquid scintillation counter. Putrescine exhibited the highest tumor accumulation followed by ornithine (4.1% and 1.8% of injected dose/g of the tumor respectively). T...
The Km and Vmax of [14C]-radiolabeled polyamines were determined for PC-3 and AT3B-1 cell lines. ... more The Km and Vmax of [14C]-radiolabeled polyamines were determined for PC-3 and AT3B-1 cell lines. With PC-3 Km values are in the following order: ornithine> spermidine> spermine> putrescine, while with AT3B-1 it was spermidine> ornithine> spermine> putrescine. To determine which of these polyamines exhibit higher accumulation, the relative uptake of all the four amines was studied with prostate (PC-3, AT3B-1, LNCaP) and non-prostate (MCF-7, KLN-205, OVCAR) cell lines at 10 and 20 microM after 1 hour. Spermine and spermidine accumulated at higher levels in prostate (AT3B-1 and LNCaP) over non-prostate cell lines (p < 0.01). Putrescine accumulated more in PC-3 and LNCaP than the non-prostate cancer cells.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010
Although the conventional stacked foil technique is the common method for evaluating experimental... more Although the conventional stacked foil technique is the common method for evaluating experimental cross sections of deuteron induced reactions on titanium, this work employed a single foil irradiation strategy. This strategy was selected for the purpose of improving the counting statistics for the reactions with low activation probabilities as it allowed for activity assay times comparable to the half-life of
ABSTRACT The radionuclide 41Ar has many ideal properties as a gas flow tracer. However, the modes... more ABSTRACT The radionuclide 41Ar has many ideal properties as a gas flow tracer. However, the modest cross-section of 40Ar for thermal neutron activation makes preparation of suitable activities of 41Ar technically difficult particularly for low flux reactors. Argon can however be trapped in a molecular complex called a clathrate that can then be irradiated. We prepared argon clathrate and explored its irradiation and stability characteristics. Argon clathrate can be used to provide gigabecquerel quantities of 41Ar even with low power reactors.
Journal of nuclear biology and medicine (Turin, Italy : 1991), 1994
The monoclonal antibody (MoAb) 174H.64 (Truscint SQ, Biomira Inc.) is a murine-derived MoAb react... more The monoclonal antibody (MoAb) 174H.64 (Truscint SQ, Biomira Inc.) is a murine-derived MoAb reacting with an extracellular surface component of the cytoskeletal matrix ectopically expressed on squamous-cell carcinoma cell-surface membranes. A chimeric form of this MoAb has also been produced by genetically modifying the Fc portion of the MoAb by the insertion of a human Fc fragment. During this process the isotype was altered from an IgG1 (murine) to an IgG3 (chimeric). Pilot and phase I/II clinical trials of the murine and chimeric 99mTc-labelled 174H.64 MoAbs have been undertaken at selected European and North American sites. As part of this evaluation serum, urine and image data were collected at specific time intervals and used to obtain a kinetic model to describe the in vivo distribution of the MoAbs. A two-compartment model of the form: C(t) = C1 e-lambda 1t + Cz e-lambda zt was found to best describe the serum distribution of radioactivity of both the murine and chimeric MoA...
This review gives a survey on the use and applications of technetium-94m ((94m)Tc) as a non-conve... more This review gives a survey on the use and applications of technetium-94m ((94m)Tc) as a non-conventional positron emission tomography (PET) radionuclide for molecular imaging. The first part of this review describes the production and processing of (94m)Tc. The second part covers basic concepts of technetium coordination chemistry with a special focus on the synthesis of (94m)Tc-labeled compounds for molecular imaging purposes. The review concludes with a summary and an outlook on the prospects of using (94m)Tc in the field of PET chemistry and molecular imaging.
Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques, 2006
PURPOSE To establish a matrix of parameters to synthesize nanoparticles of different sizes and to... more PURPOSE To establish a matrix of parameters to synthesize nanoparticles of different sizes and to investigate the cellular uptake of these nanoparticles by osteosarcoma cancer cells in order to investigate their potential as therapeutic drugdelivery carriers. METHODS Gelatin A and B were used to synthesize nanoparticles by a two-step desolvation process. Different parameters were investigated, including temperature, pH, concentration of glutaraldehyde, type of desolvating agent and nature of gelatin. For cell uptake studies, Texas Red labeled nanoparticles were incubated with 143B osteosarcoma cells and then evaluated using confocal laser scanning microscopy (CLSM). RESULTS The systematic investigation of the synthesis parameters showed that it is possible to prepare gelatin-based nanoparticles with different particle sizes and a narrow size distribution. Temperature and nature of the gelatin were the most important synthesis factors. Bioimaging using CLSM showed uptake of the nanop...
e13529 Background: Nab-paclitaxel (NP) is a solvent-free, albumin-bound nanoparticle formulation;... more e13529 Background: Nab-paclitaxel (NP) is a solvent-free, albumin-bound nanoparticle formulation; it binds to albumin receptor on endothelial cells, which in turn activates caveolin-1. Lack of solvents and receptor-mediated delivery results in decreased toxicity and increased antitumor activity of NP. Tumors expressing SPARC, and albumin-binding protein may have increased efficacy of NP. In this study we evaluated paclitaxel (P) and NP toxicities; SPARC's role in NP sensitivity; intraperitoneal NP effect and maximum tolerated dose (MTD) in mice with ovarian cancer. METHODS Human ovarian cancer (OC) cell lines OVCAR-3, SKOV-3, AG-6000 and A-2780 were seeded in 96-well plates and after 24 hours (h) of seeding, varying concentrations of NP or P were added for 72 h, after which viability was evaluated by MTS assay. SPARC expression was determined in all 4 OC lines by Western blotting. In an in vivo study, intraperitoneal injections of NP were evaluated at different doses (50, 75, 100, and 125mg/Kg) on growth of tumors in mice with OC. RESULTS Mean IC50 (concentration of drug that inhibits 50% of cell growth) for A-2780 cell line treated with P vs. NP was 16.2 vs. 0.12 nM respectively (fold difference 131); for AG-6000 was 19 vs. 0.15 nM respectively (fold difference 124); for OVCAR-3 was 2.04 vs. 1.77 nM respectively (fold difference 1.15); and for SKOV-3 was 9.5 vs. 9.04 nM (fold difference 1.05). SPARC protein was present in cells (AG-6000 and A-2780) that were more sensitive to NP but not in OVCAR-3 and SKOV-3 cell lines. All NP doses were well tolerated in mice with OC and no significant difference in post treatment recovery was noted. All mice had reduced activity and squinting for 1-1.5 hours post NP injection; and they all seemed anemic at the necroscopy. CONCLUSIONS NP had higher cytotoxic effects compared to P in AG-6000 and A-2780 cell lines which directly correlated with higher SPARC expression in these two 2 cell lines. Intraperitoneal NP was well tolerated in an OC mouse model.
This paper discusses the production methods of the most commonly used non-standard PET radionucli... more This paper discusses the production methods of the most commonly used non-standard PET radionuclides, their decay characteristics and importance in the development of novel radiopharmaceuticals for PET-based molecular imaging and potential applications in therapy.
To compare the radiation dose to normal organs from the radio-iodinated, hypoxia-binding radiosen... more To compare the radiation dose to normal organs from the radio-iodinated, hypoxia-binding radiosensitizer iodoazomycin arabinoside (IAZA) for three different isotopes of iodine. Dosimety studies with normal volunteers had been carried out with [(123) I]IAZA, a drug binding selectively to hypoxic sites. Two other isotopes of iodine, (131) I and (124) I, offer the opportunity to use IAZA as an agent for radioisotope therapy and as an imaging tracer for Positron Emission Tomography. Radioisotope dosimetry for (131) I and (124) I was performed by first deriving from the [(123) I]IAZA studies biological uptake and excretion data. The cumulated activities for (131) I or (124) I where obtained by including their half-lives when integrating the biological data and then extrapolating to infinite time points considering a) physical decay only or b) physical and biological excretion. Doses were calculated using the Medical Internal Radiation Dose (MIRD) schema (OLINDA1.1 code, Vanderbilt 2007). Compared to (123) I, organ doses were elevated on average by a factor 6 and 9 for (131) I and (124) I, respectively, if both physical decay and biological excretion were modeled. If only physical decay is considered, doses increase by a factor 18 ((131) I) and 19 ((124) I). Highest organ doses were observed in intestinal walls, urinary bladder and thyroid. Effective doses increased by a factor 11 and 14 for (131) I and (124) I, respectively, if biological and physical decay are present. Purely physical decay yields a 23-fold increase over (123) I for both, (131) I and (124) I. Owing to the significant dose increase, caused by their longer half life and the approximately 10 times larger electronic dose deposited in tissue per nuclear decay, normal tissue doses of IAZA labeled with (131) I and (124) I need to be carefully considered when designing imaging and therapy protocols for clinical trials. Effective blocking of iodine uptake in the thyroid is essential. Alberta Innovates - Health Solutions (AIHS) and Canadian Institutes of Health Research (CIHR).
The International Journal of Applied Radiation and Isotopes, 1980
The additional scintillation intensity generated as a result of annihilation radiation causes the... more The additional scintillation intensity generated as a result of annihilation radiation causes the pulse height spec18 + trum of Fluorine (635 Key max) to be broader than might be expected in comparison with 36Chlorinc (714 Key nax) The spectrum due only to the annihilation radiation was compared to the complete 18Fluorine spectrum using an aluminum absorber. Measurements made with and without this absorber indicated that the annihilation radiation alone may be detected with an efficiency of approximately 24% compared to that without the absorber. The logarithmic response of the detection system was calibrated in terms of energy to facilitate spectral comparisons.
The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of Radiopharmaceutical Chemistry and Biology, 2008
Pharmacokinetic models play a crucial role in analyzing and assessing the results of in vitro and... more Pharmacokinetic models play a crucial role in analyzing and assessing the results of in vitro and in vivo studies. In this review, comparative analysis of pharmacokinetic models under homogeneous and heterogeneous conditions is performed, placing special focus on the role of fractal theory. The concept of fractals provides a new perspective from which processes occurring in heterogeneous, confined, or poorly mixed environments can be modeled. Following a brief theoretical overview, the applicability of fractals in characterizing anatomical structures and physiological processes as well as the transport and reaction of drugs within the body is discussed. There is significant evidence that drug absorption, distribution, metabolism, and excretion are often anomalous, that is to say their behavior deviates from classical theory, and possible reasons and appropriate models are considered.
The quarterly journal of nuclear medicine : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), 2001
A review of published data on some of the problems associated in treating cancer using radioimmun... more A review of published data on some of the problems associated in treating cancer using radioimmunotherapy is presented. Potential improvements for this type of therapy using pretargeting strategies are discussed and preliminary results on a novel multistep regimen to treat human ovarian cancer are presented. A pretargeting strategy using a biotinylated, anti-CA125 monoclonal antibody (MAb) to attract biotinylated long-circulating liposomes to the surface of CA125-expressing ovarian cancer cells, was employed. Confocal laser scanning microscopy and fluorescent labels were used to establish the biodistribution patterns in NIH:OVCAR-3 (CA-125 positive) and SK-OV-3 (CA-125 negative) human ovarian cancer cells. Shedding kinetics of the pretargeted stage were measured using 125I labeled MAbs. No significant internalization of the MAb used in the pretargeting step was observed by 4 hrs. The antibody was gradually internalized starting at 6 hrs, and most of the labelled MAb was detected in ...
Uploads
Papers by S. McQuarrie