Imaging of colorectal carcinoma with radiolabeled antibodies.

Science.gov (United States)

Goldenberg, D M; Goldenberg, H; Sharkey, R M; Lee, R E; Higgenbotham-Ford, E; Horowitz, J A; Hall, T C; Pinsky, C M; Hansen, H J

1989-10-01

Colorectal cancer has been the tumor type most frequently studied with radiolabeled antibodies. Among the various antibodies, a majority of patients with colorectal cancer have received xenogeneic polyclonal or monoclonal antibodies against carcino-embryonic antigen. This review summarizes the current status of colorectal cancer imaging with radiolabeled antibodies, ie, radioimmunodetection (RAID), and examines the published studies involving carcinoembryonic antigen (CEA) antibodies and 17-1A, 19-9, and B72.3, and other monoclonal antibodies. In order to better address the issue of the current and future clinical usefulness of this emerging technology, particular attention is given to the protocols, methods, and results of the published studies. Despite differences in study parameters, antibodies and forms, labels, administration routes and doses, and scanning instruments and methods, it has been found that (1) almost no adverse reactions have been evident; (2) antibody fragments are preferred over whole immunoglobulin G reagents because they achieve higher tumor-to-background ratios earlier, thus reducing or precluding the need for dual-isotope subtraction methods or long delays before imaging; (3) use of antibody fragments, including the monovalent Fab' form, permits imaging with short-lived radionuclides of excellent photon properties, such as 123I and 99mTc; (4) circulating antigens against which the imaging antibody is directed can complex with the injected antibody, but such complexes have not prevented successful RAID; (5) patients with high serum titers of the appropriate antigen target usually have higher rates of positive RAID; (6) patients who are seronegative for the tumor antigen being studied can have positive RAID findings, which can represent the detection of occult lesions; (7) single photon emission computed tomography appears to provide better image resolution than planar scanning; (8) regardless of the sensitivity reported in any particular

Distribution and pharmacokinetics of radiolabeled monoclonal antibody OC 125 after intravenous and intraperitoneal administration in gynecologic tumors

International Nuclear Information System (INIS)

Haisma, H.J.; Moseley, K.R.; Battaile, A.; Griffiths, T.C.; Knapp, R.C.

1988-01-01

Radiolabeled monoclonal antibodies may be useful for radioimmunotherapy of gynecologic tumors. Iodine 131-labeled F(ab')2 fragments of a monoclonal antibody, OC 125, with specificity for ovarian carcinoma, were used to study the distribution and pharmacokinetics of this antibody in patients with gynecologic tumors. The radiolabeled antibody was injected intravenously or intraperitoneally into 10 patients suspected of having ovarian cancer. Blood and urine samples were used for pharmacokinetic studies, and biopsy specimens were examined for the uptake of antibody. The serum half-life of the labeled antibody was 30 hours after intravenous administration, with 20% of the injected dose per liter detected at 24 hours. After intraperitoneal injection, the appearance of antibody in serum was slow, with a maximum level of 1.4% of the injected dose per liter at 24 hours. Urinary excretion of the radiolabeled antibody was similar for intravenous and intraperitoneal administration, with approximately 50% of the injected dose excreted after 48 hours. Intraperitoneal administration of the radiolabeled antibody resulted in a higher uptake of antibody in the tumor and a lower uptake of antibody in normal tissues. On the basis of this limited study, intraperitoneal administration of radiolabeled antibody is preferred over intravenous administration for radioimmunotherapy of ovarian cancer

Use of radiolabeled monoclonal anti-B1 antibody for B lymphocyte imaging in Rhesus monkeys

International Nuclear Information System (INIS)

Letvin, N.L.; Zalutsky, M.R.; Chalifoux, L.V.; Atkins, H.L.

1987-01-01

Imaging tissues rich in B lymphocytes in man using a radiolabeled monoclonal anti-B cell antibody would be extremely useful in the clinical staging of non-Hodgkins lymphomas. Studies were done in rhesus monkeys using radiolabeled monoclonal anti-B1 antibody to determine the feasibility of such an approach. Immunohistologic studies demonstrated that infused monoclonal anti-B1 binds in vivo with specificity to B cells in lymph nodes and spleen. The kinetics of clearance of 131 I-labeled anti-B1 were determined. The B lymphocyte-rich spleen could be readily visualized by gamma camera scanning without significant background and without the need for image intensification or blood background subtraction techniques. These data support the feasibility of using anti-B1 for staging B cell lymphomas in man. (author)

Towards tumour targeting with copper-radiolabelled macrocycle-antibody conjugates

International Nuclear Information System (INIS)

Morphy, J.R.; Parker, David; Kataky, Ritu

1989-01-01

Tetraaza-macrocycles covalently attached to a monoclonal antibody may be efficiently radiolabelled with 64 Cu or 67 Cu at pH4, minimising non-specific binding to the protein, giving a kinetically stable conjugate in vivo. (author)

A radiolabeled antiglobulin assay to identify human cervical mucus immunoglobulin (Ig) A and IgG antisperm antibodies

International Nuclear Information System (INIS)

Haas, G.G. Jr.; D'Cruz, O.J.

1989-01-01

Antisperm immunoglobulin (Ig) A and IgG antibodies in human cervical mucus (CM) were identified by a radiolabeled antiglobulin assay. Cervical mucus samples from fertile and infertile women were exposed to a 1:3,200 dilution of 2-mercaptoethanol (2-ME), and 5 micrograms of the solubilized CM protein were assayed for the presence of IgA and IgG antisperm and anti-Candida activity by the radiolabeled antiglobulin assay. Purified human secretory IgA and IgG exposed to 2-ME retained the molecular integrity and functional activity of the untreated antibody molecules. CM aliquots collected after high-performance liquid chromatography (HPLC) fractionation were assessed for antisperm antibody activity; antisperm antibody activity was retained in the appropriate IgA or IgG CM fractions. The incidence of CM antisperm antibodies was minimally affected when the radiolabeled antiglobulin assay was performed with a motile sperm population. Approximately 70% of the CM IgA antisperm antibodies were of the IgA1 subclass; CM IgG was primarily of the IgG4 subclass. When Candida antigen was substituted for sperm in the radiolabeled antiglobulin assay, the CM antisperm antibodies were found to be exclusively sperm-specific. These data indicate that the radiolabeled antiglobulin assay using 2-ME to extract CM antibodies is a specific method for the assay of antisperm antibodies in CM

Towards tumour targeting with copper-radiolabelled macrocycle-antibody conjugates

Energy Technology Data Exchange (ETDEWEB)

Morphy, J.R.; Parker, David; Kataky, Ritu; Harrison, Alice; Walker, Carole; Eaton, M.A.W.; Millican, Andrew; Phipps, Alison

1989-06-15

Tetraaza-macrocycles covalently attached to a monoclonal antibody may be efficiently radiolabelled with /sup 64/Cu or /sup 67/Cu at pH4, minimising non-specific binding to the protein, giving a kinetically stable conjugate in vivo. (author).

Echinococcus granulosus: the potential use of specific radiolabelled antibodies in diagnosis by immunoscintigraphy

International Nuclear Information System (INIS)

Rogan, M.T.; Morris, D.L.; Pritchard, D.I.; Perkins, A.C.

1990-01-01

Diagnosis of hydatid disease in man is frequently dependent on the imaging of cysts in situ by techniques such as ultrasonography and CAT scans. Such methods are useful but are not specific and can lead to errors in diagnosis. The present work reports preliminary experiments on the development of a specific imaging technique for hydatid cysts using radiolabelled antibodies. A purified preparation of antigen B of hydatid fluid was used to raise polyclonal antisera in rabbits and the resulting affinity-purified IgG labelled with 131 I. Gerbils with an established Echinococcus granulosus infection were injected intraperitoneally with the labelled antibody and imaged 48 h later with a gamma camera. Hydatid cysts could be identified within the peritoneal cavity and post-mortem assessment of activity showed the cysts to contain approximately four times as much activity as the surrounding organs thereby indicating successful targeting of the antibody to the cysts. (author)

Selective suppression of antibody production with the aid of radiolabelled birch pollen allergen

International Nuclear Information System (INIS)

Filipp, G.; Biro, G.; Hartung, W.D.; Lehmann, G.

1981-01-01

In accordance with the clonal selection theory we intended to prevent the development of artificially induced birch pollen allergy in rabbits with the aid of of the radiolabelled pollen allergen (75-1000 μCi 125 I-pollen/animal) intravenously administered prior to pollen sensitization. The birch pollen allergen, in accordance with Burnet's working hypothesis, reacts only with a genetically determining B cell subpopulation. The fixation of the radiolabelled birch pollen allergen to the receptors of the competent B cell clone causes the lesion of the latter. Compared with the control group, this group of rabbits showed an extensive suppression of anaphylactic reagin-like PCA-antibodies, and haemagglutinating antibodies in the blood as well as in nasal secretion. In addition, we tried to influence the already ongoing synthesis of the antibodies with the aid of a subsequent intravenously administered radiolabelled birch pollen allergen (750-1000μCi 125 I-pollen/animal). An intensive suppression of the synthesis of antibodies could also be proved in this case. The simultaneous immunization of the control rabbits with birch pollen and egg albumin resulted in the production of antibodies against both antigens, as expected. The hot-labelled birch pollen antigen intravenously injected before or after immunization with egg albumin and birch pollen led selectively to suppression of anti-birch-pollen PCA antibodies. The synthesis of anti-egg albumin PCA antibodies was unaffected. (author)

Echinococcus granulosus: the potential use of specific radiolabelled antibodies in diagnosis by immunoscintigraphy

Energy Technology Data Exchange (ETDEWEB)

Rogan, M.T.; Morris, D.L.; Pritchard, D.I.; Perkins, A.C. (Nottingham Univ. (UK))

1990-05-01

Diagnosis of hydatid disease in man is frequently dependent on the imaging of cysts in situ by techniques such as ultrasonography and CAT scans. Such methods are useful but are not specific and can lead to errors in diagnosis. The present work reports preliminary experiments on the development of a specific imaging technique for hydatid cysts using radiolabelled antibodies. A purified preparation of antigen B of hydatid fluid was used to raise polyclonal antisera in rabbits and the resulting affinity-purified IgG labelled with {sup 131}I. Gerbils with an established Echinococcus granulosus infection were injected intraperitoneally with the labelled antibody and imaged 48 h later with a gamma camera. Hydatid cysts could be identified within the peritoneal cavity and post-mortem assessment of activity showed the cysts to contain approximately four times as much activity as the surrounding organs thereby indicating successful targeting of the antibody to the cysts. (author).

Radioimmunoimaging of experimental gliomas using radiolabelled monoclonal antibodies

International Nuclear Information System (INIS)

Glaessner, H.

1986-01-01

The biodistribution and tumour uptake of radiolabelled (131 I) glioma-seeking monoclonal antibodies (14 AC1) and their F(ab') 2 fragments were investigated in nude mice having received glioma transplants. Radioimmunoimaging by external scintigraphy at 48 and 96 hours pointed to a superior tumour localisation by the fragments that was clearly related to the dose. Wholebody determinations of the biokinetic behaviour led to the following results: Faster clearance anc more ready elimination from the blood pool for the fragments, preferential uptake in the tumour; intact antibodies; binding in the liver, spleen and lungs. The study confirmed the value of fragments of monoclonal antibodies in the diagnosis of tumours and pointed to the possibility of using intact monoclonal antibodies as carriers of radioisotopes and cytotoxic drugs within the scope of therapeutic programmes. (TRV) [de

Molecular imaging of rheumatoid arthritis by radiolabelled monoclonal antibodies: new imaging strategies to guide molecular therapies

Energy Technology Data Exchange (ETDEWEB)

Malviya, G.; Dierckx, R.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Conti, F. [Rheumatology Unit, I Faculty of Medicine and Surgery, Sapienza University of Rome (Italy); Chianelli, M. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Unit of Nuclear Medicine, Regina apostolorum Hospital, Albano, Rome (Italy); Scopinaro, F. [Nuclear Medicine Department, Sapienza University of Rome, St. Andrea Hospital, Rome (Italy); Signore, A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Centre Groningen, University of Groningen (Netherlands); Nuclear Medicine Department, Sapienza University of Rome, St. Andrea Hospital, Rome (Italy)

2010-02-15

The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-{alpha}, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with {sup 99m}Tc or {sup 111}In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for

Molecular imaging of rheumatoid arthritis by radiolabelled monoclonal antibodies: new imaging strategies to guide molecular therapies

International Nuclear Information System (INIS)

Malviya, G.; Dierckx, R.A.; Conti, F.; Chianelli, M.; Scopinaro, F.; Signore, A.

2010-01-01

The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-α, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with 99m Tc or 111 In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for therapy decision-making and

Radiolabeled antibody in the detection of infection using endocarditis as a model

International Nuclear Information System (INIS)

Mishkin, F.S.; Wong, D.W.; Dhawan, V.K.; Reese, I.C.; Thadepalli, H.

1983-01-01

The authors have examined a method to detect infections using radiolabeled antibodies. Staphylococcal endocarditis was chosen as a model because it poses a common clinical diagnostic problem. The experiments demonstrate that biologically active antibodies may be extracted and efficiently labeled by a relatively simple process. This has the potential to make the specificity of the in vivo antigen-antibody reaction available through the use of autologously extracted, labeled γ-globulin

Localisation of metastatic carcinoma by a radiolabelled monoclonal antibody

Energy Technology Data Exchange (ETDEWEB)

Smedley, H M; Ritson, A; Wraight, P; Sikora, K [Addenbrooke' s Hospital, Cambridge (UK); Hinchingbrooke Hospital, Huntingdon (UK)); Finan, P [St. James Hospital, Leeds (UK); Lennox, E S; Takei, F [Medical Research Council, Cambridge (UK)

1983-02-01

Rat monoclonal antibodies were prepared by immunising rats with human colorectal carcinoma cell membranes and fusing splenic lymphocytes with a rat myeloma. Hybridoma supernatants were screened by binding assays on membranes prepared from colorectal carcinoma tissue. One hybridoma supernatant, containing a monoclonal antibody with high binding activity on malignant compared to normal colon sections, was grown in large quantities in serum-free medium. After ammonium sulphate precipitation the antibody was purified by ion-exchange chromatography and labelled with /sup 131/I. Radiolabelled antibody was administered i.v. to 27 patients with colonic and other tumours. Scintigrams were obtained at 48 h. Computerised subtraction of the blood pool image revealed localised areas of uptake corresponding with areas of known disease in 13/16 patients with colorectal carcinoma and 3/4 patients with breast cancer.

A simple method for affinity purification of radiolabeled monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Juweid, M; Sato, J; Paik, C; Onay-Basaran, S; Weinstein, J N; Neumann, R D [National Cancer Inst., Bethesda, MD (United States)

1993-04-01

A simple method is described for affinity purification of radiolabeled antibodies using glutaraldehyde-fixed tumor target cells. The cell-bound antibody fraction is removed from the cells by an acid wash and then immediately subjected to buffer-exchange chromatography. The method was applied to the D3 murine monoclonal antibody which binds to a 290 kDa antigen on the surface of Line 10 guinea pig carcinoma cells. No alteration in the molecular size profile was detected after acid washing. Purification resulted in a significant increase in immunoreactivity by an average of 14 [+-] 47% (SD; range 4-30%). (author).

Quality control of radiolabeled antibodies through simultaneous determination of antibody concentration and specific activity using time-resolved interaction analysis and reverse kinetic fit

International Nuclear Information System (INIS)

Andersson, K.; Mihaylova, D.; Wang, E.; Abrahamsen, L.; Buijs, J.; Bjoerkelund, H.

2015-01-01

Full text of publication follows. With the advent of efficient methods for producing proteins that bind to a defined target, the number of radiolabeled proteins, and in particular antibodies, used for medical imaging and cancer therapy is increasing rapidly. In line with this increase, focus should be put on methods for the quality control (QC). Proper antibody quality is of fundamental importance to guarantee safety and consistent efficacy for the patient. Adequate QC procedures exist for small radiolabeled synthetic compounds like FDG, but antibody based radiopharmaceuticals are different. Proteins are much more complex and fragile than the synthetic compounds, and hence require new methods for adequate characterization and QC. Yet another complication is the labeling where there is a risk that a subpopulation of the protein is damaged to the level that it no longer binds the target. Therefore, a new toolbox is required to fulfill the quality characterization of radiolabeled antibodies. We have developed a QC assay for the simultaneous determination of antibody function, concentration and specific activity. The assay is based on time-resolved detection of the antibody interaction with antigen-coated magnetic beads in LigandTracer instruments. The resulting binding curve is evaluated using reverse kinetic fits, where the known interaction parameters of the antibody-antigen interaction are set constant while as the concentration and signal level are fitted. The assay takes approximately 2 hours and the majority of the time constitutes automated data collection in the instrument. The QC assay has been tested on multiple antibody-antigen interactions and consistently provides repeatable results for concentration and specific activity, both with coefficient of variation (CV) less than 15%. We believe that this QC assay can improve the quality of radiolabeled therapeutic antibodies. (authors)

Monoclonal Antibodies Radiolabeling with Rhenium-188 for Radioimmunotherapy

Science.gov (United States)

Martini, Petra; Pasquali, Micol

2017-01-01

Rhenium-188, obtained from an alumina-based tungsten-188/rhenium-188 generator, is actually considered a useful candidate for labeling biomolecules such as antibodies, antibody fragments, peptides, and DNAs for radiotherapy. There is a widespread interest in the availability of labeling procedures that allow obtaining 188Re-labeled radiopharmaceuticals for various therapeutic applications, in particular for the rhenium attachment to tumor-specific monoclonal antibodies (Mo)Abs for immunotherapy. Different approaches have been developed in order to obtain 188Re-radioimmunoconjugates in high radiochemical purity starting from the generator eluted [188Re]ReO4−. The aim of this paper is to provide a short overview on 188Re-labeled (Mo)Abs, focusing in particular on the radiolabeling methods, quality control of radioimmunoconjugates, and their in vitro stability for radioimmunotherapy (RIT), with particular reference to the most important contributions published in literature in this topic. PMID:28951872

Radiolabelled antibody imaging

International Nuclear Information System (INIS)

Perkins, A.C.

1986-01-01

A steadily growing number of tumor-associated antigens are used to raise antibodies used for the detection of human tumors by external imaging, a technique termed immunoscintigraphy. The majority of these clinical antibody studies are performed using Iodine-131, which is cheap, readily available and easily attached to protein. It has the disadvantage of having a high energy gamma emission (365 keV) which is poorly detected by modern cameras, so that increasing use is now being made of more appropriate labels with lower energies for imaging, such as Iodine-123, Indium-111 and Technetium-99m. A number of research centres in the United Kingdom are currently involved in the production of tumor-associated monoclonal antibodies, only a small number of which are finally selected for diagnostic use. These developments represent a major area of advancement in Nuclear Medicine and when used for imaging are capable of providing diagnostic information complimentary to other diagnostic techniques

Lymphoma, melanoma, colon cancer: diagnosis and treatment with radiolabeled monoclonal antibodies. The 1986 Eugene P. Pendergrass New Horizons Lecture

International Nuclear Information System (INIS)

Larson, S.M.

1987-01-01

The development of monoclonal antibodies for use as in vivo carriers of radioactivity for diagnosis and therapy of malignant neoplasms is proceeding rapidly within academic and commercial sectors. The author and his colleagues studied anticancer antibodies formed against tumors of both somatic and hematopoietic origins. Several general principles have been established with the work with somatic tumors, including the following: Improved tumor-to-normal-tissue ratios can be achieved with Fab fragments as opposed to whole IgG; each antitumor antibody has a characteristic biodistribution in humans that cannot be readily predicted from tissue or small animal studies; and for many antibodies, there is a strong dependency of tumor uptake on total mass amount of antibody administered (greater uptake with greater mass dose). Initial work with iodine-131 labeled Fab fragments of the antimelanoma antibodies, 96.5 and 48-7, documented that tumor uptake was broadly proportional to antigen content of the tumors and that under optimal conditions, some tumors were sufficiently loaded with radiolabeled antibody to serve as radiation therapy. The antitumor antibody B-72.3, as IgG, has been particularly promising when administered intraperitoneally. In ten patients who were administered I-131 B-72.3 via a Tenkhoff catheter, the sensitivity and specificity of tumor location were excellent for peritoneal implants, and in three of these patients, surgically confirmed tumor was seen with the radiolabeled antibody technique when abdominal computed tomography and magnetic resonance studies were negative

Direct 99mTc labeling of monoclonal antibodies: radiolabeling and in vitro stability

International Nuclear Information System (INIS)

Garron, J.Y.; Moinereau, M.; Pasqualini, R.; Saccavini, J.C.

1991-01-01

Direct labeling involves 99m Tc binding to different donor groups on the protein, giving multiple binding sites of various affinities resulting in an in vivo instability. The stability has been considerably improved by activating the antibody using a controlled reduction reaction (using 2-aminoethanethiol). This reaction generates sulfhydryl groups, which are known to strongly bind 99m Tc. The direct 99m Tc antibody labeling method was explored using whole antibodies and fragments. Analytical methods were developed for routine evaluation of radiolabeling yield and in vitro stability. Stable direct antibody labeling with 99m Tc requires the generation of sulfhydryl groups, which show high affinity binding sites for 99m Tc. Such groups are obtained with 2-aminoethanethiol (AET), which induces the reduction of the intrachain or interchain disulfide bond, with no structural deterioration or any loss of immunobiological activity of the antibody. The development of fast, reliable analytical methods has made possible the qualitative and quantitative assessment of technetium species generated by the radiolabeling process. Labeling stability is determined by competition of the 99m Tc-antibody bond with three ligands, Chelex 100 (a metal chelate-type resin), free DTPA solution and 1% HSA solution. Very good 99m Tc-antibody stability is obtained with activated IgG (IgGa) and Fab' fragment, which makes these substances possible candidates for immunoscintigraphy use. (author)

Whole-body effective half-lives for radiolabeled antibodies and related issues

International Nuclear Information System (INIS)

Kaurin, D.G.L.; Carsten, A.L.; Baum, J.W.; Barber, D.E.

1996-08-01

Radiolabeled antibodies (RABs) are being developed and used in medical imaging and therapy in rapidly increasing numbers. Data on the whole body half effective half-lives were calculated from external dose rates obtained from attending physicians and radiation safety officers at participating institutions. Calculations were made using exponential regression analysis of data from patients receiving single and multiple administrations. Theses data were analyzed on the basis of age, sex, isotope label, radiation energy, antibody type, disease treated, administration method, and number of administrations

Whole-body effective half-lives for radiolabeled antibodies and related issues

Energy Technology Data Exchange (ETDEWEB)

Kaurin, D.G.L.; Carsten, A.L.; Baum, J.W.; Barber, D.E.

1996-08-01

Radiolabeled antibodies (RABs) are being developed and used in medical imaging and therapy in rapidly increasing numbers. Data on the whole body half effective half-lives were calculated from external dose rates obtained from attending physicians and radiation safety officers at participating institutions. Calculations were made using exponential regression analysis of data from patients receiving single and multiple administrations. Theses data were analyzed on the basis of age, sex, isotope label, radiation energy, antibody type, disease treated, administration method, and number of administrations.

Search for new and improved radiolabeling methods for monoclonal antibodies

International Nuclear Information System (INIS)

Hiltunen, J.V.

1993-01-01

In this review the selection of different radioisotopes is discussed as well as the various traditional or newer methods to introduce the radiolabel into the antibody structure. Labeling methods for radiohalogens, for technetium and rhenium isotopes, and for 3-valent cation radiometals are reviewed. Some of the newer methods offer simplified labeling procedures, but usually the new methods are more complicated than the earlier ones. However, new labeling methods are available for almost any radioelement group and they may result in better preserved original natural of the antibody and lead to better clinical results. (orig./MG)

Preparation of monoclonal antibodies against cardiac myosin and some radiolabelling studies

International Nuclear Information System (INIS)

Bapat, K.; Venkatesh, M.; Pillai, M.R.A.; Sarma, H.D.; Sainis, K.B.

1998-01-01

Monoclonal antibodies were raised against myosin, a specific indicator of myocardial infarction and labelled with 125 I and 99m Tc. Human cardiac myosin was isolated from normal human heart and was used for raising the monoclonal antibodies by the hybridoma technique. Antibody producing clones were identified by ELISA and cloning was done by the limiting dilution technique. Of the 13 clones obtained, 4 were deemed suitable for further studies. The antibodies were grown in ascites, purified, isotyped and their cross reactions with other forms of myosin were estimated. All the clones showed negligible cross reaction with rabbit myosin, but reacted to different extents with bovine skeletal myosin. The most avid antibody Mab-4G4 was chosen for further labelling studies. Mab-4G4 was labelled with 125 I using different oxidising agents such as iodogen, chloramine-T and lactoperoxidase. Purified radioiodinated antibody with radiochemical purity >95% could be obtained by gel filtration. Immunoreactivity was retained as tested by binding to myosin immobilised on a solid support. Mab-4G4 was also labelled with 99m Tc using stannous tartrate as the reducing agent. Radiolabelling yield was ∼60%, the purity was >95% and the immunoreactivity was retained. Both the labelled preparations were tested for bio-distribution in normal and infarcted rats. The activity accumulation in the infarcted region was ∼ 1.5 and 3.5 times as that in normal heart muscle for 125 I and 99m Tc labelled Mab-4G4 respectively. The major problem with the iodinated antibody was the in vivo deiodination resulting in very high percentage of activity in the thyroid. Although the fraction of the total activity associated with the infarcted heart is not very impressive, the fact that the activities with the infarcted and normal hearths are significantly different is heartening. With further optimisation of labelling and use of F(ab)'2 fragments, better delineation of the infarct sites is aspired. (author)

Intravenous avidin chase improved localization of radiolabeled streptavidin in intraperitoneal xenograft pretargeted with biotinylated antibody

International Nuclear Information System (INIS)

Zhang Meili; Sakahara, Harumi; Yao Zhengsheng; Saga, Tsuneo; Nakamoto, Yuhi; Sato, Noriko; Nakada, Hiroshi; Yamashina, Ikuo; Konishi, Junji

1997-01-01

In the present study, we examined the effect of avidin administered intravenously (i.v.) on the biodistribution of radiolabeled streptavidin in mice bearing intraperitoneal (IP) xenografts pretargeted with biotinylated antibody. Tumors were established in nude mice by IP inoculation of LS180 human colon cancer cells. Monoclonal antibody MLS128, which recognizes Tn antigen on mucin, was biotinylated and injected IP into the IP tumor-bearing mice. Radioiodinated streptavidin was administered IP or i.v. 48 h after pretargeting of biotinylated antibody. Avidin was administered i.v. 30 min prior to streptavidin injection. The localization of radioiodinated streptavidin in the tumor pretargeted with biotinylated antibody was significantly higher than that without pretargeting and that of radioiodinated MLS128 by the one-step method. Avidin administration significantly accelerated the clearance of radioiodinated streptavidin in blood and other normal tissues and increased the tumor-to-blood radioactivity ratio regardless of administration route of streptavidin. The i.v. avidin chase improved tumor localization of radiolabeled streptavidin in the IP xenografts pretargeted with biotinylated antibody

Mesenteric vascular occlusion: a new diagnostic method using a radiolabeled monoclonal antibody reactive with platelets

International Nuclear Information System (INIS)

Oster, Z.H.; Som, P.; Zamora, P.O.

1989-01-01

A new method for diagnosing mesenteric vaso-occlusive bowel disease with the use of radioimmunoscintigraphy was developed and tested in experimental models of arterial and venous disease, as well as in a model simulating bowel strangulation. The method involves the use of a monoclonal antibody fragment mixture that binds to platelets. The antibody was labeled with technetium-99m, and imaging was performed with a gamma camera in the planar and single photon emission computed tomography modes. This method allowed visualization of areas of ischemia of 1-6 hours duration in bowel loops in 19 dogs 90-180 minutes after injection of the radiolabeled antibody. No bowel radioactivity accumulation occurred in dogs that underwent the same surgical procedure but were given a nonspecific Tc-99m-labeled antibody or in normal dogs given the specific antibody. It appears that the radiolabeled antibody used, which has higher reactivity with human platelets than with dog platelets, will be a good agent for noninvasive diagnosis of mesenteric vaso-occlusive disease in humans. It may also play a role in the intraoperative determination of the extent and location of ischemic bowel segments

Radiolabelling of antibodies with indium: Use of diethylenetriaminepentaacetic acid (DTPA) as chelating agent

International Nuclear Information System (INIS)

Loetscher, H.

1986-01-01

/sup 111/In/sup 3+/ was used to radiolabel the F(ab')/sub 2/ fragment of a monoclonal antibody (b-12) raised against a surface antigen of a mammalian breast tumor cell line (5). The in vivo distribution of the radiolabel was analyzed in mice bearing a transplant of fixed tumor cells in the left thigh. The results demonstrate that DTPA can be efficiently coupled to a tumor specific F(ab')/sub 2/ fragment and loaded with /sup 111/In/sup 3+/ yielding a stable, highly labelled complex

Current status of cancer immunodetection with radiolabeled human monoclonal antibodies.

Science.gov (United States)

De Jager, R; Abdel-Nabi, H; Serafini, A; Pecking, A; Klein, J L; Hanna, M G

1993-04-01

The use of radiolabeled murine monoclonal antibodies (MoAbs) for cancer immunodetection has been limited by the development of human antimouse antibodies (HAMA). Human monoclonal antibodies do not elicit a significant human antihuman (HAHA) response. The generation and production of human monoclonal antibodies met with technical difficulties that resulted in delaying their clinical testing. Human monoclonal antibodies of all isotypes have been obtained. Most were immunoglobulin (Ig) M directed against intracellular antigens. Two antibodies, 16.88 (IgM) and 88BV59 (IgG3k), recognize different epitopes on a tumor-associated antigen, CTA 16.88, homologous to cytokeratins 8, 18, and 19. CTA 16.88 is expressed by most epithelial-derived tumors including carcinomas of the colon, pancreas, breast, ovary, and lung. The in vivo targeting by these antibodies is related to their localization in nonnecrotic areas of tumors. Repeated administration of 16.88 over 5 weeks to a cumulative dose of 1,000 mg did not elicit a HAHA response. Two of 53 patients developed a low titer of HAHA 1 to 3 months after a single administration of 88BV59. Planar imaging of colorectal cancer with Iodine-131 (131I)-16.88 was positive in two studies in 9 of 12 and 16 of 20 patients preselected by immunohistochemistry. Tumors less than 2 cm in diameter are usually not detected. The lack of immunogenicity and long tumor residence time (average = 17 days) makes 16.88 a good candidate for therapy. Radioimmunlymphoscintigraphy with indium-111 (111In)-LiLo-16.88 administered by an intramammary route was used in the presurgical staging of primary breast cancer. The negative predictive value of lymph node metastases for tumors less than 3 cm was 90.5%. Planar and single photon emission computed tomography imaging of colorectal carcinoma with technetium-99m (99mTc) 88BV59 was compared with computed tomography (CT) scan in 36 surgical patients. The antibody scan was more sensitive than the CT scan in detecting

Monoclonal antibodies and cancer

International Nuclear Information System (INIS)

Haisma, H.J.

1987-01-01

The usefulness of radiolabeled monoclonal antibodies for imaging and treatment of human (ovarian) cancer was investigated. A review of tumor imaging with monoclonal antibodies is presented. Special attention is given to factors that influence the localization of the antibodies in tumors, isotope choice and methods of radiolabeling of the monoclonal antibodies. Two monoclonal antibodies, OC125 and OV-TL3, with high specificity for human epithelial ovarian cancer are characterized. A simple radio-iodination technique was developed for clinical application of the monoclonal antibodies. The behavior of monoclonal antibodies in human tumor xenograft systems and in man are described. Imaging of tumors is complicated because of high background levels of radioactivity in other sites than the tumor, especially in the bloodpool. A technique was developed to improve imaging of human tumor xenographs in nude mice, using subtraction of a specific and a non-specific antibody, radiolabeled with 111 In, 67 Ga and 131 I. To investigate the capability of the two monoclonal antibodies, to specifically localize in human ovarian carcinomas, distribution studies in mice bearing human ovarian carcinoma xenografts were performed. One of the antibodies, OC125, was used for distribution studies in ovarian cancer patients. OC125 was used because of availability and approval to use this antibody in patients. The same antibody was used to investigate the usefulness of radioimmunoimaging in ovarian cancer patients. The interaction of injected radiolabeled antibody OC125 with circulating antigen and an assay to measure the antibody response in ovarian cancer patients after injection of the antibody is described. 265 refs.; 30 figs.; 19 tabs

/sup 99m/Tc radiolabelling and quality control tests of anti-melanoma monoclonal antibodies and F(ab')/sub 2/ fragments for immunoscintigraphy

International Nuclear Information System (INIS)

Callegaro, L.; Deleide, G.; Dovis, M.; Cecconato, E.; Scassellati, G.A.

1986-01-01

Tumour radioimmunodetection was first developed by using radiolabelled polyclonal antibodies, raised in goats against tumour associated antigens (TAA). The availability of monoclonal antibodies to TAA has definitely contributed to more extensive in vivo use of radiolabelled antibodies. However, many factors are involved in tumour radioimmunolocalization, related either to the antibody and radioisotope features or to the natural history of the tumour itself. The experimental protocol developed by the authors allows a full evaluation of the properties of a particular MoAb.This paper illustrates the work done with on a particular set of monoclonal antibodies, raised against human melanoma associated antigens, with the aim of visualizing primary and metastatic lesions in melanoma patients

Improved tumor imaging with radiolabeled monoclonal antibodies by plasma clearance with anti-antibody column

International Nuclear Information System (INIS)

Lear, J.L.; Kasliwal, R.; Feyerabend, A.; Bunn, P.; Dienhart, D.G.; Johnson, T.K.; Glenn, S.D.; Maddock, S.W.

1990-01-01

This paper reports on imaging of tumors with use of radiolabeled monoclonal antibodies (MoAs) that often hindered by high levels of background activity. The ability to lower blood pool MoA activity at a selected time after injection offers a potential method to reduce background while preserving tumor uptake. Toward this goal, the authors investigated the process of clearing MoA from patients' plasma with use of an anti-antibody column. One patient with breast cancer and four with lung cancer were given intravenous injection of 5 mCi of indium-111 KC4 (Coulter Immunology) and imaged at 20, 24, 48, and 72 hours with use of a whole-body canner coupled to a computer. Plasma clearance was performed between the 20- and 24-hour images with use of a COBEIA system. Images were inspected visually and analyzed by region-of-interest quantification

Effects of radiolabelled monoclonal antibody infusion on blood leukocytes in cancer patients

International Nuclear Information System (INIS)

Gridley, D.S.; Slater, J.M.; Stickney, D.R.

1990-01-01

This study was undertaken to investigate the effects of a single infusion of radiolabelled murine monoclonal antibody (MAb) on peripheral blood leukocytes in cancer patients. Eleven patients with disseminated colon cancer, malignant melanoma, or lung adenocarcinoma were infused with 111In-labelled anti-ZCE 025, anti-p97 type 96.5c, or LA 20207 MAb, respectively. Blood samples were obtained before infusion, immediately after infusion (1 hr), and at 4 and 7 days postinfusion. Flow cytometry analysis of CD3+, CD4+, CD8+, CD16+, and CD19+ lymphocytes showed increasing CD4:CD8 ratios in seven patients after infusion. This phenomenon was not restricted to antibody subclass or to type of cancer. Two of the remaining patients exhibited a marked post-infusion increase in CD8+ cells. In all three patients with malignant melanoma, decreasing levels of CD16+ lymphocytes were noted after infusion and natural killer cell cytotoxicity showed fluctuations which paralleled the changes in the CD16+ subpopulation. Oxygen radical production by phagocytic cells was markedly affected in three subjects. These results suggest that a single infusion of radiolabelled murine MAb may alter the balance of critical lymphocyte subpopulations and modulate other leukocyte responses in cancer patients

Radiolabelled cellular blood elements

International Nuclear Information System (INIS)

Sinzinger, H.

1990-01-01

This book reports on radiolabelled cellular blood elements, covering new advances made during the past several years, in particular the use of Tc-99 as a tracer for blood elements. Coverage extends to several radiolabelled monoclonal antibodies that are specific for blood components and may label blood elements in vivo

Radiolabeled monoclonal antibodies. Development of a new method to remove circulating activity - diagnostic applications and implications for therapy

International Nuclear Information System (INIS)

Norrgren, K.

1993-04-01

The aim of this thesis was to develop and investigate the usefulness of extracorporeal immunoadsorption (ECIA) to remove circulating activity after the localization of radiolabeled monoclonal antibodies to tumors. A compartment model, based on the biokinetics of 125 I-labeled antibodies 96.5 was developed to estimate the effect of ECIA on the tumor-to-normal tissue ratios. ECIA was simulated at different times after injection of the antibodies and the calculations showed an increased diagnostic ratio for several hours after the ECIA procedure, and that an enhancement of the therapeutic ratio was possible. These results led to the development of animal models where the ECIA could be evaluated and the biokinetic behaviour of different radiolabeled monoclonal antibodies investigated with and without the application of ECIA. A general ECIA method, based on biotinylated antibodies and an avidin agarose column as adsorbent, was developed. Studies in tumor bearing nude rats showed that ECIA enhanced of the tumor-to-normal tissue activity ratios by a factor of 4 for the liver, kidneys and bone marrow. For the L6 antibody, the image contrast of tumors localized in one kidney of the rats, was increased from 1.1 to 1.6. A software anthropomorphic phantom was used in Monte Carlo simulations of clinically realistic scintillation camera image acquisition. The effect of ECIA on the contrast enhancement and on the detectability of simulated tumors located centrally in the liver was studied. The contrast increased linearly with an increasing tumor/liver ratio. The contrast was higher for SPECT than for planar images and a contrast of 1.15 required a tumor/liver activity ratio of 1.9 for SPECT and 4.5 for planar images. ECIA in combination with SPECT imaging of radiolabeled antibodies has a great potential in increasing the detectability of tumors. These studies have shown the possibility with ECIA to increase the contrast in radioimmunoimaging and to enhance the therapeutic ratio

Radiolabelling of autologous leucocytes: technique and clinical application

International Nuclear Information System (INIS)

Strobl-Jaeger, E.; Kolbe, H.; Ludwig, H.; Sinzinger, H.

1988-01-01

Gamma-camera imaging after injection of radiolabelled autologous leucocytes can be very helpful in the diagnosis, localization and further clinical treatment of inflammatory diseases. We present a technique allowing sterile separation of white blood cells and labelling with 99m Tc-phytate or -oxine and with 111 In-oxine, -oxine sulphate or -tropolone. The method is non-invasive and the radiation dose amounts to less than 80 mrad using 100 μCi 111 Indium. The use of radiolabelled granulocytes is of particular diagnostic value in patients with septicaemia of unknown origin. Whole body scanning allows not only visualization of enhanced splenic uptake in septicaemia, but also localization of an inflammatory process. Preferential indications for a diagnostic approach using radiolabelled granulocytes are inflammatory abdominal processes which cannot easily be documented by means of other non-invasive techniques, such as inflammatory bowel disease (Crohn's diseases and ulcerative colitis), arthritic processes and abscesses of the liver and spleen, as well as subphrenic and retroperitoneal abscesses. Untreated osteomyelitis can be located with the help of labelled granulocytes, but in patients treated with antibiotics a false negative result is obtained in approximately 50 % of cases for as yet unknown reasons, even in the presence of a still active osteomyelitic process. (Authors)

Localization of radiolabeled anti-CEA antibody in subcutaneous and intrahepatic colorectal xenografts: influence of tumor size and location within host organ on antibody uptake

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Dearling, Jason L.J. [Cancer Research UK Targeting and Imaging Group, Research Department of Oncology, UCL Cancer Institute, Paul O' Gorman Building, University College London, London WC1E 6BT (United Kingdom)], E-mail: j.dearling@hotmail.com; Flynn, Aiden A.; Qureshi, Uzma [Cancer Research UK Targeting and Imaging Group, Research Department of Oncology, UCL Cancer Institute, Paul O' Gorman Building, University College London, London WC1E 6BT (United Kingdom); Whiting, Stephen [Department of Clinical Biochemistry, Royal Free and University College Medical School, UCL, Royal Free Campus, London NW3 2PF (United Kingdom); Boxer, Geoffrey M.; Green, Alan; Begent, Richard H.J.; Pedley, R. Barbara [Cancer Research UK Targeting and Imaging Group, Research Department of Oncology, UCL Cancer Institute, Paul O' Gorman Building, University College London, London WC1E 6BT (United Kingdom)

2009-11-15

Introduction: Radioimmunotherapy (RIT) has been shown to be more effective against solid tumor micrometastases, possibly due to an inverse relationship between tumor size and radiolabeled antibody uptake. In this study, the accretion of radiolabeled antibody in intrahepatic micrometastases in an experimental model was investigated using quantitative digital autoradiography, enabling the analysis of antibody uptake in microscopic tumors. Methods: Mice bearing subcutaneous or intrahepatic metastatic models of LS174T colorectal cancer were injected with radiolabeled anti-carcinoembryonic antigen antibody ([{sup 125}I]A5B7). Tissues were taken to investigate distribution of radionuclide and tumor uptake. In a therapy study, mice bearing intrahepatic metastatic tumors were injected with [{sup 131}I]A5B7. Results: Subcutaneous tumors and large metastatic deposits had similar uptake (e.g., {approx}15%ID/g at 24 h). Small metastatic deposits had higher uptake (e.g., {approx}80%ID/g at 24 h) and prolonged retention at later time points. Small deposit uptake was significantly reduced by accompanying large deposits in the same liver. RIT resulted in increased survival time (untreated mean survival of 21.6{+-}12.9 vs. treated mean survival of 39.1{+-}30.8 days), but there was a large range of response within groups, presumably due to variation in pattern and extent of tumor as observed in the biodistribution study. Liver function tests and body weight did not change with tumor growth or therapy response, strongly supporting the use of in vivo imaging in metastatic tumor therapy studies. Conclusions: Radioimmunodetection and therapy might be greatly influenced by the size and distribution of intrahepatic tumor deposits.

Localization of radiolabeled anti-CEA antibody in subcutaneous and intrahepatic colorectal xenografts: influence of tumor size and location within host organ on antibody uptake

International Nuclear Information System (INIS)

Dearling, Jason L.J.; Flynn, Aiden A.; Qureshi, Uzma; Whiting, Stephen; Boxer, Geoffrey M.; Green, Alan; Begent, Richard H.J.; Pedley, R. Barbara

2009-01-01

Introduction: Radioimmunotherapy (RIT) has been shown to be more effective against solid tumor micrometastases, possibly due to an inverse relationship between tumor size and radiolabeled antibody uptake. In this study, the accretion of radiolabeled antibody in intrahepatic micrometastases in an experimental model was investigated using quantitative digital autoradiography, enabling the analysis of antibody uptake in microscopic tumors. Methods: Mice bearing subcutaneous or intrahepatic metastatic models of LS174T colorectal cancer were injected with radiolabeled anti-carcinoembryonic antigen antibody ([ 125 I]A5B7). Tissues were taken to investigate distribution of radionuclide and tumor uptake. In a therapy study, mice bearing intrahepatic metastatic tumors were injected with [ 131 I]A5B7. Results: Subcutaneous tumors and large metastatic deposits had similar uptake (e.g., ∼15%ID/g at 24 h). Small metastatic deposits had higher uptake (e.g., ∼80%ID/g at 24 h) and prolonged retention at later time points. Small deposit uptake was significantly reduced by accompanying large deposits in the same liver. RIT resulted in increased survival time (untreated mean survival of 21.6±12.9 vs. treated mean survival of 39.1±30.8 days), but there was a large range of response within groups, presumably due to variation in pattern and extent of tumor as observed in the biodistribution study. Liver function tests and body weight did not change with tumor growth or therapy response, strongly supporting the use of in vivo imaging in metastatic tumor therapy studies. Conclusions: Radioimmunodetection and therapy might be greatly influenced by the size and distribution of intrahepatic tumor deposits.

Localisation of lung cancer by a radiolabelled monoclonal antibody against the c-myc oncogene product

Energy Technology Data Exchange (ETDEWEB)

Chan, S Y.T.; Evan, G I; Ritson, A; Watson, J; Wraight, P; Sikora, K

1986-11-01

A set of mouse monoclonal antibodies against the c-myc oncogene product, a 62,000 dalton nuclear binding protein involved in cell cycle control, has been constructed by immunisation with synthetic peptide fragments. One such antibody, CT14, was radiolabelled with /sup 131/I and administered to 20 patients with different malignant diseases. Good tumour localisation was observed in 12 out of 14 patients with primary bronchial carcinoma but not in patients with pulmonary metastases from primary tumours elsewhere. Successfully localised tumours were all 3 cm or more in diameter. Monoclonal antibodies against oncogene products may provide novel selective tools for the diagnosis and therapy of cancer.

Aspects of monitoring and quality assurance for radiolabeled antibodies

International Nuclear Information System (INIS)

Barber, D.E.

1992-06-01

This report provides an informational resource and guide for the US Nuclear Regulatory Commission (NRC) and NRC licensees who produce or use radiolabeled antibodies (RABs). Components of quality assurance programs related to the production and use of RABs are reviewed and evaluated, and recommendations are made on dosage calibrations, exposure control, monitoring, and personnel requirements. Special emphasis is placed on dose calibrators because these instruments are used extensively to measure the dosage of radiopharmaceuticals to be administered to patients. The difficulties of using dose calibrators to quantify dosages of beta- and alpha-emitters are discussed. The advantages and disadvantages of using other instruments are examined, and recommendations are made on the types of instruments to be used for different applications. 46 refs., 8 tabs

Development of radiolabelling techniques of anti-CEA monoclonal antibody

International Nuclear Information System (INIS)

Castiglia, S.G. de

1998-01-01

The purpose of this work was to label monoclonal and polyclonal antibodies with 99 Tc m such as the ior-CEA-1 antibody and polyclonal IgG using a direct method, to check the radiochemical and biological behavior of labelled products, to prepare it under sterile and apyrogenic conditions as a lyophilized kit and to employ it in clinical trials. In addition, a photoactivation method was used to label polyclonal IgG with 99 Tc m and to compare with the established method using mercaptoethanol (2-ME) as the reducing agent. Finally polyclonal IgG was labelled using an indirect method in which a chelator was covalently attached to the protein and the 99 Tc m added as glucoheptonate complex. The properties of 99 Tc m when labelled with monoclonal and polyclonal antibodies by different methods were assessed by in vitro and in vivo studies

Systemic perfusion: a method of enhancing relative tumor uptake of radiolabeled monoclonal antibodies

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Wahl, R.L.; Piko, C.R.; Beers, B.A.; Geatti, O.; Johnson, J.; Sherman, P. (Michigan Univ., Ann Arbor, MI (USA). Dept. of Internal Medicine)

1989-01-01

The authors evaluated the feasibility of systemic vascular perfusion with saline (mimicking plasmapheresis) as a method to enhance tumor-specific monoclonal antibody (MoAb) tumor/background ratios. Perfusion in rats dropped whole-body 5G6.4 levels significantly at both perfusion times. The drop in whole-body radioactivity with perfusion was significantly greater for the animals perfused at 4 h post i.v. 5G6.4 antibody injection (48.3 +- 5.1%) than for those perfused at 24h post i.v. antibody injection (32.9 +- 2.9%). In the nude mice with ovarian cancer xenografts, gamma camera images of tumors were visually and quantitatively by computer image analysis enhanced by perfusion, with a 2.33-fold greater decline in whole body uptake than in the tumor. These studies show that much background antibody radioactivity can be removed using whole-body perfusion with saline, that the decline in whole body activity is larger with 4 than 24h perfusion and that tumor imaging can be enhanced by this approach. This and similar approaches that increase relative tumor antibody uptake such as plasmapheresis may be useful in imaging and therapy with radiolabeled antibodies.

Radioimmunodetection of hepatocellular carcinoma with a radiolabeled antibody to alpha fetoprotein

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Ishii, N; Nakata, K; Muro, T [Nagasaki Univ. (Japan). School of Medicine

1982-03-01

The present study was undertaken to investigate whether or not radiolabeled antibody to Alpha-fetoprotein (AFP) intravenously administered accumulates in AFP-producing tumors. Rats with subcutaneously transplanted hepatoma or with heptoma produced in liver by 3'-Me-DAB, and 12 patients with hepatocellular carcinoma (HCC) were studied. In animal experiments, the tumor localization was clearly demonstrated by total body scintigraphy 48 to 168 hours after the injection of the radioiodinated antibody. The rats were sacrificed and radioactivity in tissues was counted. Tumor tissues showed the highest counts. In patients with HCC, the imaging was made with a gamma camera usually 24 and 48 hours after injection of I-131-labeled antibody. In order to make the contrast of tumor image clear, nonspecific background images obtained by administration of Tc-99m-labeled serum albumin were subtracted from the images obtained by I-131 labeled antibody with a computer. In 6 of 12 patients with HCC, the tumor location could successfully demonstrated. However, tumor with sizes below 2 cm in diameter which were able to be detected by the celiac angiography were not detectable. Interestingly the images were more clear in patients with relatively higher serum AFP levels. In the blood of patient given injection of AFP radioantibody, both immune complex and free antibody were able to be detected at least for 120 hours so that the presence of free antigen (AFP) did not appear to prevent tumor radioimmunodetection. The information obtained concerning the biochemical factors which influence antibody localization in the tumor would provide better method for radioimmunodetection with antitumor antibodies.

Radiolabelled blood elements techniques and clinical applications

International Nuclear Information System (INIS)

Thakur, M.L.

1992-01-01

Over the past few years, in nuclear medicine, the diagnostic applications of radiolabelled blood elements in general, and of radiolabelled white blood cells in particular, have become increasingly popular. This is primarily due to the introduction of lipid soluble 111 In-oxine as an agent, which not only is an excellent and a reliable tracer for blood cells but also enables the investigators to study the in vivo cell kinetics and map the localization of labelled cells by external gamma scintigraphy. The tracer has the modest half life of 67 hours and decays with the emission of two gamma photons (173 and 247 keV) in high abundance. This technique has provided a powerful tool to study the in vivo cell kinetics in health and localize abnormal lesions in diseases which invoke intense focal cellular concentration

Radiolabelled blood elements techniques and clinical applications

Energy Technology Data Exchange (ETDEWEB)

Thakur, M L

1993-12-31

Over the past few years, in nuclear medicine, the diagnostic applications of radiolabelled blood elements in general, and of radiolabelled white blood cells in particular, have become increasingly popular. This is primarily due to the introduction of lipid soluble {sup 111}In-oxine as an agent, which not only is an excellent and a reliable tracer for blood cells but also enables the investigators to study the in vivo cell kinetics and map the localization of labelled cells by external gamma scintigraphy. The tracer has the modest half life of 67 hours and decays with the emission of two gamma photons (173 and 247 keV) in high abundance. This technique has provided a powerful tool to study the in vivo cell kinetics in health and localize abnormal lesions in diseases which invoke intense focal cellular concentration 5 figs, 2 tabs

Tumor-specific binding of radiolabeled G-22 monoclonal antibody in glioma patients

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Yoshida, Jun; Wakabayashi, Toshihiko; Mizuno, Masaaki; Sugita, Kenichiro; Oshima, Motoo; Tadokoro, Masanori; Sakuma, Sadayuki [Nagoya Univ. (Japan). Faculty of Medicine; Seo, Hisao

1992-03-01

Iodine-131-labeled G-22 monoclonal antibody F(ab'){sub 2} fragment reacting specifically with a glioma-associated surface glycoprotein was administered to 12 glioma patients to investigate its use in radioimaging of intracranial gliomas. No immediate or delayed side effects were attributable to antibody injection. Nine patients received the radiolabeled complex intravenously. The images of low-grade gliomas were generally poor and disappeared within 4 days. High-contrast images were obtained beyond the 7th day in high-grade gliomas except one case in the pineal region. Three patients received intraventricular or intratumoral administration. Clear images of all tumors were demonstrated from the 2nd until later than the 7th day. One patient with cerebrospinal fluid (CSF) dissemination of brainstem glioma demonstrated negative CSF cytology after intraventricular administration. (author).

Dosimetry of radiolabeled monoclonal antibodies used for therapy

International Nuclear Information System (INIS)

Myers, M.J.; Hooker, G.R.; Epenetos, A.A.

1986-01-01

The present state of radiotherapy using labeled antibodies is reviewed. From the point of view of dosimetry, antibody therapy does not seem to have reached a stable and practicable enough state to provide an input to any but rather tentative dosimetry models. These, therefore, should not be taken too far until the problems of antibody targeting have been more fully developed. Some of the instrumental techniques for acquiring dosimetric data under clinical conditions are discussed as are some of the techniques of therapy in use today. 8 references, 3 figures

Radioimmunodetection of hepatocellular carcinoma with a radiolabeled antibody to alpha fetoprotein

International Nuclear Information System (INIS)

Ishii, Nobuko; Nakata, Keisuke; Muro, Toyokichi

1982-01-01

The present study was undertaken to investigate whether or not radiolabeled antibody to Alpha-fetoprotein (AFP) intravenously administered is accumulate in AFP-producing tumors. Rats with subcutaneously transplanted hepatoma or with heptoma produced in liver by 3'-Me-DAB, and 12 patients with hepatocellular carcinoma (HCC) were studied. In animal experiments, the tumor localization was clearly demonstrated by total body scintigraphy 48 to 168 hours after the injection of the radioiodinated antibody. The rats were sacrificed and radioactivity in tissues was counted. Tumor tissues showed the highest counts. In patients with HCC, the imaging was made with a gamma camera usually 24 and 48 hours after injection of I-131-labeled antibody. In order to make the contrast of tumor image clear, nonspecific background images obtained by administration of Tc-99m-labeled serum albumin were subtracted from the images obtained by I-131 labeled antibody with a computer. In 6 of 12 patients with HCC, the tumor location could successfully demonstrated. However, tumor with sizes below 2 cm in diameter which were able to be detected by the celiac angiography were not detectable. Interes tingly the images were more clear in patients with relatively higher serum AFP levels. In the blood of patient given injection of AFP radioantibody, both immune complex and free antibody were able to be detected at least for 120 hours so that the presence of free antigen (AFP) did not appear to prevent tumor radioimmunodetection. The information obtained concerning the biochemical factors which influence antibody localization in the tumor would provide better method for radioimmunodetection with antitumor antibodies. (author)

166Ho and 90Y labeled 6D2 monoclonal antibody for targeted radiotherapy of melanoma: Comparison with 188Re radiolabel

International Nuclear Information System (INIS)

Thompson, S.; Ballard, B.; Jiang, Z.; Revskaya, E.; Sisay, N.; Miller, W.H.; Cutler, C.S.; Dadachova, E.; Francesconi, L.C.

2014-01-01

Introduction: An approach to radioimmunotherapy (RIT) of metastatic melanoma is the targeting of melanin pigment with monoclonal antibodies (mAbs) to melanin radiolabeled with therapeutic radionuclides. The proof of principle experiments were performed using a melanin-binding antibody 6D2 of IgM isotype radiolabeled with a β emitter 188 Re and demonstrated the inhibition of tumor growth. In this study we investigated the efficacy of 6D2 antibody radiolabeled with two other longer lived β emitters 90 Y and 166 Ho in treatment of experimental melanoma, with the objective to find a possible correlation between the efficacy and half-life of the radioisotopes which possess high energy β (E max > 1.5 MeV) emission properties. Methods: 6D2 was radiolabeled with longer lived β emitters 90 Y and 166 Ho in treatment of experimental melanoma in A2058 melanoma tumor-bearing nude mice. The immunoreactivity of the radiolabeled 6D2 mAb, its in vitro binding to the MNT1 human melanoma cells, the biodistribution and therapy in A2058 human melanoma bearing nude mice as well as dosimetry calculations were performed. Results: When labeled with the longer lived 90 Y radionuclide, the 6D2 mAb did not produce any therapeutic effect in tumor bearing mice while the reduction of the tumor growth by 166 Ho-6D2 was very similar to the previously reported therapy results for 188 Re-6D2. In addition, 166 Ho-labeled mAb produced the therapeutic effect on the tumor without any toxic effects while the administration of the 90 Y-labeled radioconjugate was toxic to mice with no appreciable anti-tumor effect. Conclusions: 166 Ho-labeled mAb to melanin produced some therapeutic effect on the tumor without any toxic effects while the administration of the 90 Y-labeled radioconjugate was toxic to mice with no appreciable anti-tumor effect. We concluded that the serum half-life of the 6D2 carrier antibody matched well the physical half-life of 166 Ho to deliver the tumoricidal absorbed dose to the

Antibody guided diagnosis and therapy of brain gliomas using radiolabeled monoclonal antibodies against epidermal growth factor receptor and placental alkaline phosphatase

International Nuclear Information System (INIS)

Kalofonos, H.P.; Pawlikowska, T.R.; Hemingway, A.

1989-01-01

Twenty-seven patients with brain glioma were scanned using 123 I-labeled monoclonal antibodies against epidermal growth factor receptor (EGFR1) or placental alkaline phosphatase (H17E2). Successful localization was achieved in 18 out of 27 patients. Eleven out of 27 patients were also studied using a nonspecific control antibody (11.4.1) of the same immunoglobulin subclass and observable tumor localization was also achieved in five patients. The specificity of targeting was assessed by comparing images obtained with specific and nonspecific antibodies and by examining tumor and normal tissue biopsies after dual antibody administration. Ten patients with recurrent grade III or IV glioma who showed good localization of radiolabeled antibody were treated with 40-140 mCi of 131 I-labeled antibody delivered to the tumor area intravenously (n = 5) or by infusion into the internal carotid artery (n = 5). Six patients showed clinical improvement lasting from 6 mo to 3 yr. One patient continues in remission (3 yr after therapy), but the other five who responded initially relapsed 6-9 mo after therapy and died. No major toxicity was attributable to antibody-guided irradiation. Targeted irradiation by monoclonal antibody may be clinically useful and should be explored further in the treatment of brain gliomas resistant to conventional forms of treatment

Monoclonal antibody-dendrimer conjugates enable radiolabeling of antibody with markedly high specific activity with minimal loss of immunoreactivity

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, H.; Togashi, K. [Kyoto Univ. (Japan). School of Medicine; Sato, N.; Saga, T.; Nakamoto, Y.; Ishimori, T.; Konishi, J. [Dept. of Nuclear Medicine and Medical Imaging, Kyoto Univ. Graduate School of Medicine, Kyoto (Japan); Toyama, S. [Inst. for Virus Research, Kyoto Univ., Kyoto (Japan); Brechbiel, M.W. [Chemistry Section, Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, Md. (United States)

2000-09-01

For the purpose of radioimmunotherapy, labelling of monoclonal antibody with high specific activity is often necessary, especially when using a radionuclide with a shorter half-life. Polyamine dendrimers (PAMAM) are novel synthetic polymeric molecules with large numbers of amine residues on their spherical surface. In order to bind large numbers of radiometals to single antibody molecules, the generation-4 PAMAM (G4), which has 64 amines, was conjugated with 43 molecules of 2-(p-isothiocyanatobenzyl)-6-methyl-diethylene triamine penta-acetic acid (1B4M), a derivative of DTPA. This product [G4-(1B4M){sub 43}] was then conjugated with OST7, a murine monoclonal IgG{sub 1}. We evaluated the achievable specific activity for {sup 111}In labeling, immunore-activity, biodistribution, and tumor targeting in mice of the {sup 111}In- or {sup 153}Gd-OST7-G4-(1B4M){sub 43} as compared with radiolabeled OST7-1B4M or 56C-1B4M. The maximum specific activity of {sup 111}In-OST7-G4-(1B4M){sub 43} and {sup 111}In-OST7-1B4M was 470 and 8.7 GBq/mg (12,700 and 263 mCi/mg), respectively. Immunoreactivity of radiolabeled OST7-G4-(1B4M){sub 43} and OST7-1B4M, as determined by the binding to KT005 cells expressing the antigen, was respectively 91% and 84% of that of {sup 125}I-labelled OST7. Biodistribution studies for preparations with maximum specific activity in normal mice 3 h after injection showed that {sup 111}In- or {sup 153}Gd-OST7-G4-(1B4M){sub 43} cleared faster from the blood and accumulated more in the liver than did {sup 111}In- or {sup 153}Gd-OST7-1B4M. The dendrimer 1B4M [G4-(1B4M){sub 64}] itself showed similar saturation effects with metals. The radioactivity in all the other organs reflected the rapid clearance of radioactivity from the blood. {sup 153}Gd-OST7-G4-(1B4M){sub 43} showed specific accumulation in the KT005 tumor. In conclusion, we could successfully bind 49 times as many metal atoms to an antibody molecule as is possible with conventional metal labeling for

N-(m-[125I]iodophenyl)maleimide: an agent for high yield radiolabeling of antibodies

International Nuclear Information System (INIS)

Khawli, L.A.; Van den Abbeele, A.D.; Kassis, A.I.

1992-01-01

In an effort to radiolabel antibodies, N-(m-[ 125 I]iodophenyl)maleimide (m-[ 125 I]IPM) was prepared by the demetallation of an N-[m-tri-(n-butyl)stannylphenyl]maleimide intermediate. The unlabeled intermediate was synthesized in ≥ 75% yield using a palladium catalyzed reaction of hexabutylditin with m-bromoaniline, followed by reaction with maleic anhydride and ring annulation. All products were confirmed by NMR and elemental analysis. Labeling with 125 I was carried out in a biphasic mixture containing chloramine-T (radiochemical yield ≥ 70%). Rabbit IgG modified with the heterobifunctional crosslinking agent N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) and bovine serum albumin were conjugated with m-[ 125 I]IPM (yield: 40 and 80%, respectively). In addition, m-[ 125 I]IPM was conjugated to rabbit IgG subunits (HL) in 70% yield. The in vitro stability of the radiolabeled proteins in serum showed < 1% deiodination over 24h. (author)

Radiolabelling of glycosylated MFE-23::CPG2 fusion protein (MFECP1) with 99mTc for quantitation of tumour antibody-enzyme localisation in antibody-directed enzyme pro-drug therapy (ADEPT).

Science.gov (United States)

Francis, R J; Mather, S J; Chester, K; Sharma, S K; Bhatia, J; Pedley, R B; Waibel, R; Green, A J; Begent, R H J

2004-08-01

MFECP1 is a glycosylated recombinant fusion protein composed of MFE-23, a high-affinity anti-carcinoembryonic antigen (CEA) single chain Fv (scFv), fused to the enzyme carboxypeptidase G2 (CPG2), and has been constructed for use in antibody-directed enzyme pro-drug therapy (ADEPT). Radiolabelling of glycosylated MFECP1 with technetium-99m was developed for the purpose of determining tumour localisation of MFECP1 in a phase I ADEPT clinical study. The method used was 99mTc-carbonyl [99mTc(H2O)3(CO)3]+ (abbreviated to TcCO) mediated labelling of 99mTc to the hexahistidine (His) tag of MFECP1. MFECP1 fusion protein was labelled with TcCO under a variety of conditions, and this was shown to be a relatively simple and robust method. Tissue biodistribution was assessed in a CEA-expressing LS174T (human colon carcinoma) nude mouse xenograft model. Tissues were taken at 1, 4 and 6 h for assessment of distribution of radioactivity and for measurement of CPG2 enzyme levels. The amount of radioactivity retained by the tumour proved to be an accurate estimation of actual measured enzyme activity, indicating that this radiolabelling method does not appear to damage the antibody-antigen binding or the enzyme activity of MFECP1. However, correlation between CPG2 enzyme activity and measured radioactivity in liver, spleen and kidney was poor, indicating retention of radioactivity in non-tumour sites but loss of enzyme activity. The high retention of technetium radioisotope in normal tissues may limit the clinical applicability of this radiolabelling method for MFECP1; however, these results suggest that this technique does have applicability for measuring the biodistribution of His-tagged recombinant proteins.

Radiolabelling of glycosylated MFE-23::CPG2 fusion protein (MFECP1) with 99mTc for quantitation of tumour antibody-enzyme localisation in antibody-directed enzyme pro-drug therapy (ADEPT)

International Nuclear Information System (INIS)

Francis, R.J.; Chester, K.; Sharma, S.K.; Bhatia, J.; Pedley, R.B.; Green, A.J.; Begent, R.H.J.; Mather, S.J.; Waibel, R.

2004-01-01

MFECP1 is a glycosylated recombinant fusion protein composed of MFE-23, a high-affinity anti-carcinoembryonic antigen (CEA) single chain Fv (scFv), fused to the enzyme carboxypeptidase G2 (CPG2), and has been constructed for use in antibody-directed enzyme pro-drug therapy (ADEPT). Radiolabelling of glycosylated MFECP1 with technetium-99m was developed for the purpose of determining tumour localisation of MFECP1 in a phase I ADEPT clinical study. The method used was 99m Tc-carbonyl [ 99m Tc(H 2 O) 3 (CO) 3 ] + (abbreviated to TcCO) mediated labelling of 99m Tc to the hexahistidine (His) tag of MFECP1. MFECP1 fusion protein was labelled with TcCO under a variety of conditions, and this was shown to be a relatively simple and robust method. Tissue biodistribution was assessed in a CEA-expressing LS174T (human colon carcinoma) nude mouse xenograft model. Tissues were taken at 1, 4 and 6 h for assessment of distribution of radioactivity and for measurement of CPG2 enzyme levels. The amount of radioactivity retained by the tumour proved to be an accurate estimation of actual measured enzyme activity, indicating that this radiolabelling method does not appear to damage the antibody-antigen binding or the enzyme activity of MFECP1. However, correlation between CPG2 enzyme activity and measured radioactivity in liver, spleen and kidney was poor, indicating retention of radioactivity in non-tumour sites but loss of enzyme activity. The high retention of technetium radioisotope in normal tissues may limit the clinical applicability of this radiolabelling method for MFECP1; however, these results suggest that this technique does have applicability for measuring the biodistribution of His-tagged recombinant proteins. (orig.)

Tc-99m direct radiolabeling of monoclonal antibody ior egf/r3: quality control and image studies in mice

International Nuclear Information System (INIS)

Dias, Carla Roberta; Marczewski, Barbara; Moraes, Vanessa; Barboza, Marycel Figols de; Osso Junior, Joao Alberto

2005-01-01

Monoclonal antibodies (Mabs) have been useful for immunoscintigraphic applications in clinical diagnosis since they were introduced in the practice of nuclear medicine. The ior egf/r3 (Centis, Cuba) is a murine monoclonal antibody against epidermal growth factor receptor (EGF-R) and has been widely used in the radioimmunodiagnosis of tumors of epithelial origin. Labeled with 99m Tc, its main application in Nuclear Medicine is the follow up, detection and evaluation of tumor recurrences. The objective of this work is to describe the preparation of a lyophilized formulation (kit) for radiolabeling the Mab ior egf/r3 with 99m Tc for immunoscintigraphic applications. Radiolabeling efficiency, effects on immunoreactivity, image studies and stability of the formulation are reported. The study demonstrated that the kit formulation can be labeled with 99m Tc at high yields and can be used to visualize in vivo human tumors of epithelial origin by immunoscintigraphy studies.(author)

Nuclear oncology with monoclonal antibodies and peptides

International Nuclear Information System (INIS)

Hosono, Makoto

1998-01-01

Imaging and therapy using radiolabeled monoclonal antibodies have proved useful in many clinical studies. However, immunogenicity of mouse antibodies to human and insufficient tumor-to-normal tissue ratios remained to be solved. Chimerization and humanization by genetic engineering, and multistep targeting techniques have enabled lower immunogenicity and higher tumor-to-normal tissue contrast. Peptides like somatostatin-analogs have been reportedly useful in imaging tumors, which are either somatostatin receptor positive or negative. Elevated normal tissue accumulation of radiolabeled peptides is a drawback in aiming internal radiation therapy. (author). 51 refs

Study of conjugation and radiolabeling of monoclonal antibody rituximab for use in radionuclide therapy

International Nuclear Information System (INIS)

Massicano, Adriana Vidal Fernandes

2011-01-01

Lymphomas are tumors originated from the transformation of a lymphocyte in the lymphatic system. The most common lymphoma is the Non-Hodgkin Lymphoma (NHL). Advances in immunology and molecular biology have been improving NHL's detection and treatment strategies development, such as Radioimmunotherapy (RIT). Rituximab is an anti-CD20 monoclonal antibody used as immunotherapeutic to treat refractory or relapsed NHL. The goal of the present work was to conjugate this antibody to DOTA-NHS-ester bifunctional chelator and to radiolabel it with 177 Lu radioisotope in order to develop a radio immunotherapeutic agent for NHL's treatment. Different rituximab to DOTA molar ratios (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 and 1:1000) were evaluated in order to determine the best condition for obtaining the highest radiochemical purity of radio immunotherapeutic. The stability of the unlabeled immuno conjugated was evaluated by high performance liquid chromatography (HPLC) for up to 240 days in different storage conditions. The stability of the labeled preparations was evaluated either after storing at 2-8 degree C or incubation in human serum at 37 degree C. The binding to serum proteins was also determined. In vivo studies were performed in healthy Swiss mice, in order to characterize the biological properties of labeled conjugate. Finally, preliminary studies of radio immuno conjugated competitive binding to CD20 positive Raji cells were carried out in order to analyze if the process of conjugation and radiolabeling compromises the immunoreactivity of the antibody. The conjugation applying lower antibody to chelator molar ratios (1:5, 1:10 and 1:20) showed high stability when stored for up to 240 days in different conditions. The HPLC analysis showed that the monoclonal antibody conjugated in molar ratio 1:50 was labeled with higher radiochemical purity (> 95%) when purified in PD-10 column. This conjugate showed reasonable stability at 2-8 degree C. The analysis of the

Radiolabeling of biological vectors by poly-aza-macrocyclic complexes

International Nuclear Information System (INIS)

Moreau, M.

2012-01-01

This work conducted at the 'Institut de Chimie Moleculaire de l'Universite de Bourgogne' carries at first on the synthesis of bifunctional chelating agents suitable for the chelation of trivalent radio-metals, including indium-111. The greater part of this work was then dedicated to the grafting of a DOTA derivative bifunctional chelating agent on different antibodies or fragments of monoclonal antibodies: trastuzumab (anti-HER2 treatment of breast cancer), cetuximab (anti EGFR, treatment of many cancers, including colorectal cancer) and abciximab (antiplatelet). Particular attention was paid to the characterization of various immuno-conjugates. The critical step of this thesis consisted in the indium-111 radiolabeling of two previously prepared immuno-conjugates: trastuzumab and cetuximab. These steps of radiolabelling allowed us to determine the immunoreactive fraction and affinity of each radiotracer. Thus, we were able to study the in vivo biodistribution of the radiotracers in tumour-bearing mice by SPECT-CT. We also developed an original method for the labeling of a Fab antibody fragment in order to monitor the biodistribution of the antiplatelet agent (abciximab). Finally, we also validated the concept of multimodal imaging through grafting and radiolabeling of a bimodal agent for optical and SPECT imaging on bacterial lipopolysaccharide. Thanks to this work, we gained an expertise in antibodies radiolabeling. The results obtained allow to consider the labeling of antibodies or other biomolecules, and the use of other radionuclides for PET imaging and radioimmunotherapy. (author)

Cloning and sequencing of V genes from anti-osteosarcoma monoclonal antibodies TP-1 and TP-3: Location of lysine residues and implications for radiolabeling

International Nuclear Information System (INIS)

Olafsen, Tove; Bruland, Oeyvind S.; Zalutsky, Michael R.; Sandlie, Inger

1995-01-01

Monoclonal antibodies TP-1 and TP-3 are of potential utility for the radioimmunodiagnosis of osteosarcoma in both human and canine patients. The V genes of these antibodies were cloned and sequenced and to facilitate radiolabeling of these proteins, the location of the lysine residues within these sequences have been determined. The V-domains of TP-1 contain a total of 12 lysines, 10 in the framework region and 2 in the CDR region, while the V-domains of TP-3 contain a total of 14 lysines, 11 in the framework region and 3 in the CDR regions. Using space-filling models, the availability of each lysine residue for radiolabeling, and potential interference with antigen binding was predicted

Cloning and sequencing of V genes from anti-osteosarcoma monoclonal antibodies TP-1 and TP-3: Location of lysine residues and implications for radiolabeling

Energy Technology Data Exchange (ETDEWEB)

Olafsen, Tove; Bruland, Oeyvind S.; Zalutsky, Michael R.; Sandlie, Inger

1995-08-01

Monoclonal antibodies TP-1 and TP-3 are of potential utility for the radioimmunodiagnosis of osteosarcoma in both human and canine patients. The V genes of these antibodies were cloned and sequenced and to facilitate radiolabeling of these proteins, the location of the lysine residues within these sequences have been determined. The V-domains of TP-1 contain a total of 12 lysines, 10 in the framework region and 2 in the CDR region, while the V-domains of TP-3 contain a total of 14 lysines, 11 in the framework region and 3 in the CDR regions. Using space-filling models, the availability of each lysine residue for radiolabeling, and potential interference with antigen binding was predicted.

Gene transfer strategies for improving radiolabeled peptide imaging and therapy

International Nuclear Information System (INIS)

Rogers, B.E.; Buchsbaum, D.J.; Zinn, K.R.

2000-01-01

Utilization of molecular biology techniques offers attractive options in nuclear medicine for improving cancer imaging and therapy with radiolabeled peptides. Two of these options include utilization of phage-panning to identify novel tumor specific peptides or single chain antibodies and gene transfer techniques to increase the antibodies and gene transfer techniques to increase the number of antigen/receptor sites expressed on malignant cells. The group has focused on the latter approach for improving radiolabeled peptide imaging and therapy. The most widely used gene transfer vectors in clinical gene therapy trials include retrovirus, cationic lipids and adenovirus. It has been utilized adenovirus vectors for gene transfer because of their ability to accomplish efficient in vivo gene transfer. Adenovirus vectors encoding the genes for a variety of antigens/receptors (carcinoembryonic antigen, gastrin-releasing peptide receptor, somatostatin receptor subtype 2 (SSTr2) have all shown that their expression is increased on cancer cells both in vitro and in vivo following adenovirus infection. Of particular interest has been the adenovirus encoding for SSTr2 (AdCMVSSTr2). Various radioisotopes have been attached to somatostatin analogues for imaging and therapy of SSTr2-positive tumors both clinically and in animal models. The use of these analogues in combination with AdCMVSSTr2 is a promising approach for improving the detection sensitivity and therapeutic efficacy of these radiolabeled peptides against solid tumors. In addition, it has been proposed the use of SSTr2 as a marker for imaging the expression of another cancer therapeutic transgene (e.g. cytosine deaminase, thymidine kinase) encoded within the same vector. This would allow for non-invasive monitoring of gene delivery to tumor sites

Tc-{sup 99m} direct radiolabeling of monoclonal antibody ior egf/r3: quality control and image studies in mice

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta; Marczewski, Barbara; Moraes, Vanessa; Barboza, Marycel Figols de; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), SP (Brazil). Centro de Radiofarmacia]. E-mail: crdias@ipen.br

2005-10-15

Monoclonal antibodies (Mabs) have been useful for immunoscintigraphic applications in clinical diagnosis since they were introduced in the practice of nuclear medicine. The ior egf/r3 (Centis, Cuba) is a murine monoclonal antibody against epidermal growth factor receptor (EGF-R) and has been widely used in the radioimmunodiagnosis of tumors of epithelial origin. Labeled with 99m Tc, its main application in Nuclear Medicine is the follow up, detection and evaluation of tumor recurrences. The objective of this work is to describe the preparation of a lyophilized formulation (kit) for radiolabeling the Mab ior egf/r3 with 99m Tc for immunoscintigraphic applications. Radiolabeling efficiency, effects on immunoreactivity, image studies and stability of the formulation are reported. The study demonstrated that the kit formulation can be labeled with 99m Tc at high yields and can be used to visualize in vivo human tumors of epithelial origin by immunoscintigraphy studies.(author)

Anti sperm antibodies detection in infertile patients by radioimmunometry

International Nuclear Information System (INIS)

ELnabarawy, F.; Megahed, Y.M.; Tadrous, G.A.; Hamada, T.; Elbadry, A.

1992-01-01

Three different methods of testing for anti sperm antibodies were compared: complement cytotoxicity, sperm agglutination, and radiolabelled anti globulin antibody technique, for detection of anti sperm antibodies in serum and secretions (seminal plasma and cervical mucus). Sample from 120 patients with infertility were investigated by the previous three methods. The results of unexplained infertile patients revealed wide variations in figures, concerning the positivity of anti sperm antibody whether in their serum or secretions, by using the cytotoxicity or sperm agglutination tests. Using a specific radiolabelled anti globulin test, a subset of patients (44.9% in the serum of men and 50% in seminal plasma) with IgG anti sperm antibody was identified, and this antibody was present in 65.4% and 78,6% of infertile wives sera and cervical mucus, respectively. Therefore, this test has been used to identify and quantitate antibodies directed toward other human cell surfaces. It was concluded that this radiolabelled method is a clinically useful and a potentially versatile procedure that can be successfully applied to the diagnosis and management of patients with suspected immunologic infertility. 1 fig., 5 tab

Blood cells radiolabelling achievements, challanges, and prospects

International Nuclear Information System (INIS)

Weininger, Jolie; Trumper, Jacob

1987-01-01

A study in performed about the different ways of blood cells radiolabelling. The labelling of red blood cells (RBCs), compared with that of other blood cells, is facilitated by several factors such as a) RBCs are the most abundant of all cellular blood elements, b) they are relatively easy to separate and manipulate in vitro, c) in vitro they are less dependent on energy and nutricional requirements, d) they are easy to label due to the presence of a variety of cellular transport mechanism. 99m Tc was reconized and became as the ideal radioisotope for nuclear medicine imaging. After considerations about RBCs radiolabelling, it is presented a new in vitro technique based on the BNL kit, developed by Srivastava and co-workers. The Sorep optimized one-vial labelling method for 2 ml whole blood. In vivo and in vivo/in vitro labelling are presented too, the last method seems to combine the superior binding efficiency of in vitro labelling with the convenience of in vitro labelling. Lipophilic chelates of 111 In with oxine, acetylacetone, tropolone and mercaptopyridine N-oxide have been used successfully for labelling platelets and leukocytes. A very promising aproach is the labelling of cells with monoclonal antibodies and the developing optimized methods for in vitro labelling with various radionuclides such as 123 I, 125 I, 131 I, 111 I and 99m Tc. The advantages of the antibody technique over conventional cell labelling are shown. (M.E.L.) [es

The radiolabeled monoclonal antibodies in immunoscintigraphy and radioimmunotherapy: current state and perspectives

International Nuclear Information System (INIS)

Chatal, J. F.

2000-01-01

The antibodies can be satisfactorily labelled with technitium-99 m or indium-111 for tumor immunoscintigraphy. The immunoscintigraphy is not useful for the primary tumor diagnosis. It can be useful for the diagnosis of the some cancer extension and for recurrent tumor visualization. The immunoscintigraphy is widely competed with Positron Emission Tomography (PET) which gives accurate results. In the future the immunoscintigraphy, in pre-therapeutic stage, contribute to the estimation of the dose delivered to the tumor and to normal organs for adopting or not a radioimmunotherapy. The antibodies can also be labeled with Iodine-131 for an application in radioimmunotherapy (RIT). The RIT is efficient in the non-Hodgkin's lymphoma treatment because of their great radiosensitivity. Until now the results have been very modest in solid tumor treatment but methodological and biotechnological progresses have to improve the efficiency especially for the small tumors. In the future iodine-131 which requires the confinement (very expensive) of patients will be substituted by yttrium-90 beta emitter, more energetic than iodine-131 and can be injected in walking case. In the long term, the alpha emitter radionuclides (astatine-211 or bismuth-213) can be used for hematologic cancer treatment. In conclusion the future of radiolabeled monoclonal antibodies is essentially therapeutic. The radioimmunotherapy associated to the chemotherapy give promising perspectives for the radiosensitive cancer treatment and in general small solid tumor treatment (F.M.)

Radiolabelled antibodies in imaging

International Nuclear Information System (INIS)

Khaw, B.A.; Haber, E.

1982-01-01

Recent technological advances make it possible to produce pure (monoclonal) antibodies in unlimited quantities without the need for continuous immunization of animals and to label these antibodies with a variety of radionuclides which can be traced by single-photon computed tomography. An outline review of the state of the art is presented, with particular reference to the imaging of myocardial infarcts and to tumour imaging studies using labelled monoclonal antibodies (sup(99m)Tc and 125 I). Lengthy bibliography. (U.K.)

CT-SPECT fusion to correlate radiolabeled monoclonal antibody uptake with abdominal CT findings

International Nuclear Information System (INIS)

Kramer, E.L.; Noz, M.E.; Sanger, J.J.; Megibow, A.J.; Maguire, G.Q.

1989-01-01

To enhance the information provided by computed tomography (CT) and single photon emission computed tomography (SPECT) performed with radiolabeled, anti-carcinoembryonic antigen monoclonal antibody (MoAb), the authors performed fusion of these types of images from eight subjects with suspected colorectal adenocarcinoma. Section thickness and pixel size of the two studies were matched, coordinates of corresponding points from each study were identified, and CT sections were translated, rotated, and reprojected to match the corresponding SPECT scans. The CT-SPECT fusion enabled identification of anatomic sites of tumor-specific MoAb accumulation in four cases, showed non-specific MoAb accumulation in two, and helped confirm information only suggested by the two studies separately in one

Radiolabeled antibody imaging in the management of colorectal cancer. Results of a multicenter clinical study

International Nuclear Information System (INIS)

Doerr, R.J.; Abdel-Nabi, H.; Krag, D.; Mitchell, E.

1991-01-01

Presurgical colorectal cancer patients (n = 116) received single intravenous infusions of 1 mg of CYT-103 (OncoScint CR103), an immunoconjugate of monoclonal antibody B72.3, radiolabeled with 111In. Following gamma camera imaging, 103 patients underwent an operative procedure: 92 had primary or recurrent colorectal carcinoma, 1 patient evaluated for recurrence of colorectal cancer had a second primary malignancy (small cell lung), and 10 patients had no demonstrable evidence of malignancy. 111In-CYT-103 immunoscintigraphic findings were consistent with the pathologic diagnoses for 70% of patients with colorectal cancer and 90% of disease-free patients. Antibody imaging contributed to surgical decision making through the detection of occult disease (12% of patients) and the confirmation of localized, potentially resectable disease without regional or metastatic spread. Seven patients (6%) experienced adverse effects, primarily fevers and itching, and 33% of patients developed antibodies to murine immunoglobulin after administration of 111In-CYT-103. The results of this study suggest that 111In-CYT-103 is a useful diagnostic tool for the presurgical evaluation of colorectal cancer patients

Quantitation of passive cutaneous anaphylaxis (PCA) by using radiolabelled antigen

International Nuclear Information System (INIS)

Ring, J.; Seifert, J.; Brendel, W.

1978-01-01

The major problem of detecting reaginic antibody by passive cutaneous anaphylaxis (PCA) is the quantitation of the dye reaction. Radiolabelled antigen was used in an attempt to quantitate the PCA reaction (Radio-PCA). Antisera containing reaginic antibody against human serum albumin (HSA) were produced in rabbits. These antisera were injected into normal rabbit skin in different dilutions. Twentyfour hours later HSA was injected intravenously either with Evans Blue or as 125-I-HSA. Radioactivity found in antibody-containing skin was significantly higher than in control specimens containing saline or normal rabbit serum, as low as antiserum dilutions of 1:1,000. Compared with Evans Blue technique Radio-PCA was able to distinguish quantitatively between different antiserum dilutions at a higher level of statistical significance. (author)

Radiolabeling parameters of 177Lu-DOTA-RITUXIMAB

International Nuclear Information System (INIS)

Massicano, Adriana V.F.; Alcarde, Lais F.; Oliveira, Ricardo S.; Mengatti, Jair; Araujo, Elaine B. de

2013-01-01

Cancer treatment using radioimmunotherapy (RIT) has been the focus of much research in the last two decades. In RIT, a radioisotope is coupled to a monoclonal antibody (mAb) to form a tumor-specific target agent to improve the cytocidal effect of the mAbs. RIT allows the systemic delivery of radiation to disease target by mAbs while sparing normal tissues. Rituximab® (Mabthera - Roche) is a chimeric mouse-human monoclonal antibody; it selectively binds with high affinity to the CD20 antigen, a hydrophobic transmembrane protein, which is expressed on B-lymphocytes and in more than 90% of B cell non-Hodgkin's lymphomas (NHL). The conjugation and radiolabeling process involve special conditions of pH and temperature, long processes of manipulation and mixing. All this process can damage the antibody structure and compromise its clinical application. Therefore, these parameters must be largely studied. The aim of this work was to evaluate the best radiolabeling conditions of DOTA-rituximab. Briefly, 10 mg of antibody previously purified by ultrafiltration device was conjugated with DOTA-NHS-ester (Macrocyclics) in 50 fold molar excess. The reaction was conducted for 1 hour in phosphate buffer pH 8.0 and gently mixing at room temperature, remaining for 24 hours under refrigeration. The immunoconjugated was purified by size exclusion column and ultrafiltration device. The radiolabeled parameters studied were: immunoconjugated mass, activity of 177 LuCl 3 , reaction time, temperature and pH. The radiochemical purity of the preparations was determined using analysis by thin layer chromatography (TLC-SG plates). The best studied condition presented radiochemical purity above 95% and the integrity of antibody was preserved. (author)

Correlating labeling chemistry and in-vitro test results with the biological behavior of radiolabeled proteins

International Nuclear Information System (INIS)

Srivastava, S.C.; Meinken, G.E.

1985-01-01

Monoclonal antibodies possess enormous potential for delivery of therapeutic amounts of radionuclides to target antigens in vivo, in particular for tumor imaging and therapy. Translation of this concept into practice has encountered numerous problems. Specifically whereas general protein radiolabeling methods are applicable to antibodies, immunological properties of the antibodies are often compromised resulting in reduced in-vivo specificity for the target antigens. The bifunctional chelating agent approach shows the most promise, however, development of other agents will be necessary for widespread usefulness of this technique. The effects of labeling chemistry on the in-vivo behavior of several monoclonal antibodies are described. 30 refs., 4 figs., 10 tabs

Detection of antisalivary duct antibody from Sjoegren's syndrome by an autoradiographic method

International Nuclear Information System (INIS)

Cummings, N.A.; Tarpley, T.M. Jr.

1978-01-01

A new technique to detect anti-salivary duct antibody (ASDA) has been developed by using autoradiographic, rather than immunofluorescent methods. The antibody activity detected by autoradiography is probably classic ASDA. Both techniques may be consecutively performed on the same tissue section without attenuation of either. Some of the potential advantages of the radiolabelling of ASDA are pointed out, and a few preliminary experiments using the labelled antibody as a marker are presented. (Auth.)

Radiolabeling parameters of {sup 177}Lu-DOTA-RITUXIMAB

Energy Technology Data Exchange (ETDEWEB)

Massicano, Adriana V.F.; Alcarde, Lais F.; Oliveira, Ricardo S.; Mengatti, Jair; Araujo, Elaine B. de, E-mail: adriana.avfernandes@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Cancer treatment using radioimmunotherapy (RIT) has been the focus of much research in the last two decades. In RIT, a radioisotope is coupled to a monoclonal antibody (mAb) to form a tumor-specific target agent to improve the cytocidal effect of the mAbs. RIT allows the systemic delivery of radiation to disease target by mAbs while sparing normal tissues. Rituximab® (Mabthera - Roche) is a chimeric mouse-human monoclonal antibody; it selectively binds with high affinity to the CD20 antigen, a hydrophobic transmembrane protein, which is expressed on B-lymphocytes and in more than 90% of B cell non-Hodgkin's lymphomas (NHL). The conjugation and radiolabeling process involve special conditions of pH and temperature, long processes of manipulation and mixing. All this process can damage the antibody structure and compromise its clinical application. Therefore, these parameters must be largely studied. The aim of this work was to evaluate the best radiolabeling conditions of DOTA-rituximab. Briefly, 10 mg of antibody previously purified by ultrafiltration device was conjugated with DOTA-NHS-ester (Macrocyclics) in 50 fold molar excess. The reaction was conducted for 1 hour in phosphate buffer pH 8.0 and gently mixing at room temperature, remaining for 24 hours under refrigeration. The immunoconjugated was purified by size exclusion column and ultrafiltration device. The radiolabeled parameters studied were: immunoconjugated mass, activity of {sup 177}LuCl{sub 3}, reaction time, temperature and pH. The radiochemical purity of the preparations was determined using analysis by thin layer chromatography (TLC-SG plates). The best studied condition presented radiochemical purity above 95% and the integrity of antibody was preserved. (author)

A new technique for radiolabelling of humic substances

International Nuclear Information System (INIS)

Franke, K.; Patt, J.T.; Patt, M.; Kupsch, H.; Steinbach, J.

2004-01-01

A new method of radiolabelling of humic substances (HS) in the aqueous phase has been developed. Radiolabelling with the short-lived positron-emitter 18 F was carried out via diazonium coupling to electron-rich aromatic residues of the humic substances. Labelling yields of up to 75% were obtained after optimization of the synthetic procedure. Introductory experimental steps were performed for testing the labelling stability of the humic substances with ultrafiltration, electrophoretic and chromatographic methods. (orig.)

Monoclonal antibodies: potential role in radiation therapy and oncology

International Nuclear Information System (INIS)

Order, S.E.

1982-01-01

Specificity, which is a hallmark of the immune system, will be used in radiation oncology in both diagnosis and therapy through the application of radiolabelled monoclonal and polyclonal antibodies. Antigenic specificities, antibody preparations, and the tumor as a target for radiolabelled antibody is reviewed. Several clinical situations, i.e. single tumor cell suspensions, intraperitoneal single cells and masses, and solid tumors are reviewed in regard to both immune antibody targeting and specific differences between tumors in these regions. The concentration of tumor associated antigens is introductory to radiolabelled antibodies in diagnosis. In the radiation therapy of solid tumors, data regarding tumor dose, tumor effective half-life, varied antibody preparations, and the use of radiolabelled antibody as a method of tumor implantation is discussed using antiferritin 131 I-IgG as a model in hepatoma. The theoretical applications of monoclonal antibody integrated in cancer therapy are then presented as a new goal for future development

Pharmacokinetic study of radiolabeled anti-colorectal carcinoma monoclonal antibodies in tumor-bearing nude mice

Energy Technology Data Exchange (ETDEWEB)

Douillard, J.Y.; Chatal, J.F.; Curtet, C.; Kremer, M.; Saccavini, J.C.; Peuvrel, P.; Koprowski, H.

1985-09-01

Monoclonal antibodies (MoAbs) 17-1A and 19-9, which specifically bind human colorectal carcinoma (CRC) cells, were tested for their usefulness in localizing colorectal tumors in nude mice. One of the /sup 131/I-labeled MoAbs and an irrelevant /sup 125/I-labeled immunoglobulin of the same isotype were injected into nude mice simultaneously bearing a human CRC and a human melanoma. The percentage of the injected dose of antibody per gram of tissue, the CRC/tissue ratios of antibody distribution, and the localization indicees were calculated at various time intervals (2 h to 10 days). For both MoAbs, labeling to a specific activity of 10 ..mu..Ci/..mu..g by the iodogen method gave optimum immunoreactivity. The accumulation of MoAb 17-1A in CRC reached its maximum at 5 days and remained at this level for up to 9 days postinjection. For MoAb 19-9, which detects a circulating antigen shed by the tumor into the serum, the accumulation in the CRC was maximum at 24 h, and decreased thereafter. The CRC/organ ratios and localization indices for-both MoAbs increased with time in the CRC tissue, but remained low and unchanged in the melanoma and normal tissue. Using F(ab')/sub 2/ antibody fragments, faster kinetics with earlier maximum accumulation, higher tumor/organ ratios, and better localization indices were achieved than with intact MoAbs. The data obtained was useful in defining parameters which must be considered before radiolabeled MoAbs are used in cancer patients for diagnostic purposes.

A new technique for radiolabelling of humic substances

Energy Technology Data Exchange (ETDEWEB)

Franke, K.; Patt, J.T.; Patt, M.; Kupsch, H.; Steinbach, J. [Inst. of Interdisciplinary Isotope Research, Leipzig (Germany)

2004-07-01

A new method of radiolabelling of humic substances (HS) in the aqueous phase has been developed. Radiolabelling with the short-lived positron-emitter {sup 18}F was carried out via diazonium coupling to electron-rich aromatic residues of the humic substances. Labelling yields of up to 75% were obtained after optimization of the synthetic procedure. Introductory experimental steps were performed for testing the labelling stability of the humic substances with ultrafiltration, electrophoretic and chromatographic methods. (orig.)

Application of the bootstrap method to radiolabeled antibody dosimetry from planar images

International Nuclear Information System (INIS)

Papenfuss, T.; Saunder, T.H.; Schleyer, P.J.; O'Keefe, G.J.; Scott, A.M.

2002-01-01

Full text: Planar imaging dosimetry of radiolabeled antibody treatment uses the MIRD schema to compute dose to an organ from the calculated activity in that and other organs. The calculated activity in an organ is a function of the average count rates in the organ, a standard and an appropriate background measurement. The geometric mean of conjugate averages, together with an attenuation factor is used to provide an approximate attenuation correction. It is sometimes desirable to know the variance of the activity in an organ in order to apply weighted least squares regression to the data. This is particularly important when incorporating more accurate data from autoradiography of biopsied tissue into the analysis, but is also useful when some data points have low signal. While the geometric mean image can be used to calculate the variance of an organ's count rate. It is difficult to calculate the variance of the activity, since the organ in question, the standard and the background all contribute to it. Bootstrap methods are Monte Carlo techniques that can be used to estimate parameters from data and to determine the accuracy of the estimation. By bootstrapping pixel values in the organ, background and standard ROIs, it is possible to calculate many realisations of the organ activity and calculate its variance. As an example, bootstrapping is applied to the pharmacodynamic analysis of 131 I-huA33 in colon. The data includes planar whole body images, and autoradiographs and planar images of a resected colon. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

Enhanced specificity in immunoscreening of expression cDNA clones using radiolabeled antigen overlay

International Nuclear Information System (INIS)

Chao, S.; Chao, L.; Chao, J.

1989-01-01

A highly sensitive and specific method has been developed for immunoscreening clones from an expression cDNA library. The procedures utilize a radiolabeled antigen detection method described originally for the immunoblotting of plasma proteins. Screening of rat alpha 1-antitrypsin clones was used. Comparison between Western blots of alpha 1-antitrypsin using both labeled antigen and protein A detection methods showed that the former yielded lower background and greater sensitivity than the latter. Further, this technique was shown to have a lower detection limit of less than 20 ng through Western blot analysis of varying concentrations of alpha 1-antitrypsin. The procedures are based on the expression of the protein by cDNA clones containing the DNA inserts in the correct reading frame. Following the transfer of phage proteins to nitrocellulose membranes, the bivalent antibodies bind monovalently to both nitrocellulose-bound-antigen in the phage lysates and radiolabeled antigen. The radiolabeled antigen overlay method is superior to the protein A detection method in sensitivity, specificity and reproducibility. This improved method can be applied in general for screening expression cDNA libraries, provided that the specific antiserum and radiolabeled antigen are available

Detection of antisalivary duct antibody from Sjögren's syndrome by an autoradiographic method.

Science.gov (United States)

Cummings, N A; Tarpley, T M

1978-01-01

A new technique to detect anti-salivary duct antibody (ASDA) has been developed by using autoradiographic, rather than immunofluorescent methods. The antibody activity detected by autoradiography is probably classic ASDA. Both techniques may be consecutively performed on the same tissue section without attenuation of either. Some of the potential advantages of the radiolabelling of ASDA are pointed out, and a few preliminary experiments using the labelled antibody as a marker are presented.

Clinical experience in humans with radiolabeled antibody for tumor detection

International Nuclear Information System (INIS)

Morrison, R.T.; Lyster, D.M.; Szasz, I.; Alcorn, L.N.; Huckell, V.F.; Rhodes, B.; Breslow, K.; Burchiel, S.

1982-01-01

I-131 and Tc-99m labeled polyclonal or monoclonal antibody and fragments of antibody, specific to human chorionic gonadotropin (hCG) or to a melanoma cell surface antigen (MCSA) were injected into proven cancer patients. Using standard homeostasis parameters, and scanning techniques, the safety and efficacy of each antibody was evaluated. Antibody fragments were expected to clear faster from the circulation allowing for earlier imaging and a better target-to-non-target ratio. The technetium label may perturb the antiboby's kinetics so that clearance is more rapid for both whole antibody and fragments. After a statistical evaluation of all parameters measured pre and post injection it was concluded that no acute toxicity reactions were present in any patient studied. Scan results were not acceptable for a tumor detecting procedure used in routine practice. Tumor upake was seen in less than 10% of scans

Radiolabelled anti-human fibrin antibody: a new thrombus-detecting agent

International Nuclear Information System (INIS)

Bosnjakovic, V.; Jankovic, B.D.; Horvat, J.; Cvoric, J.

1977-01-01

Rabbit anti-human fibrin globulin (A.F.G.) was labelled with iodine ( 131 I) and used as a thrombus-detecting agent. 131 I-A.F.G. labelled thrombi were displayed by means of a gamma scintillation camera. Normal subjects and patients with thrombo-phlebitis of legs, acute fibrin depositions other than thrombi, and chronic varicosities were examined. The 131 I-A.F.G. technique detected both formed thrombi and those that were forming and could discriminate between acute thrombosis and chronic varicosities. Thrombo-phlebitis and extravascular fibrin depositions were best demonstrated between 24 and 72 hours after 131 I-A.F.G. injection. Radiolabelled A.F.G. in normal veins and chronic varicosities was best displayed within 6 hours of injection. (author)

Radiolabeling and biotinylation of internalizing monoclonal antibody chimeric BR96: Potential use of extracorporeal immunoadsorption with enhanced tumor radioactivity retention of Iodine, Indium and Rhenium

International Nuclear Information System (INIS)

Chen, JianQing.

1997-01-01

In this thesis, methodology of radiolabeling and simultaneous biotinylation for internalizing monoclonal antibody chimeric BR96 have been investigated by using three element groups of potential therapeutic radionuclides iodine, indium and rhenium, and their different labeling methods. The biodistribution and kinetics of biotinylated and radiolabeled chiBR96 have been studied in colon carcinoma isografted rats. The potential use of ECIA, based on the biotin-avidin concept, has been evaluated and compared with the approach of avidin 'chase' in the same animal tumor model with respect to an enhancement of tumor-to-normal tissue (T/N) activity ratio. 131 refs

Radiolabeling and biotinylation of internalizing monoclonal antibody chimeric BR96: Potential use of extracorporeal immunoadsorption with enhanced tumor radioactivity retention of Iodine, Indium and Rhenium

Energy Technology Data Exchange (ETDEWEB)

Chen, JianQing

1997-01-01

In this thesis, methodology of radiolabeling and simultaneous biotinylation for internalizing monoclonal antibody chimeric BR96 have been investigated by using three element groups of potential therapeutic radionuclides iodine, indium and rhenium, and their different labeling methods. The biodistribution and kinetics of biotinylated and radiolabeled chiBR96 have been studied in colon carcinoma isografted rats. The potential use of ECIA, based on the biotin-avidin concept, has been evaluated and compared with the approach of avidin `chase` in the same animal tumor model with respect to an enhancement of tumor-to-normal tissue (T/N) activity ratio. 131 refs.

Kinetics and tissue distribution of the radiolabeled chimeric monoclonal antibody MOv18 IgG and F(ab')2 fragments in ovarian carcinoma patients

NARCIS (Netherlands)

Buist, M. R.; Kenemans, P.; den Hollander, W.; Vermorken, J. B.; Molthoff, C. J.; Burger, C. W.; Helmerhorst, T. J.; Baak, J. P.; Roos, J. C.

1993-01-01

Twenty-four patients suspected of having ovarian carcinoma received i.v. injection with a combination of radiolabeled intact IgG (1 mg) and F(ab')2 fragments (1 mg) of the chimeric monoclonal antibody MOv18, each form labeled with 1.85 MBq 131I or 125I. Laparotomy was performed either 2 or 6 days

In vitro and in vivo analysis of radiolabeled clindamycin hydrogel gel by radioscintigraphic techniques

International Nuclear Information System (INIS)

Kumar, N.; Datta, M.; Chopra, M.K.; Soni, N.L.; Mittal, G.; Singh, T.; Bhatnagar, A.; Bhawna

2010-01-01

Full text: Acne is one of the common dermatological problems caused by microorganism Acne vulgaris, therefore being used commonly in the treatment of acne. Clindamycin is the 7- deoxy, 7- chloro congener of the lincomycin, a macrolide antibiotic derived from Streptomyces lincolnensis. This study was performed for in-vitro and in-vivo estimation of radiolabeled clindamycin hydrogel using radioscintigraphic techniques for transdermal permeation. Clindamycin was supplied as a gift sample by Glenmark Research Laboratory (Mumbai, India) and other chemicals and reagents used were of analytical grade and were purchased from Merck Chemicals (India). Clindamycin was radiolabeled with 99m Tc-pertechnetate using stannous chloride as a reducing agent. Radiolabeled clindamycin was characterized for its stability at room temperature and in physiological conditions (serum). Clindamycin hydrogel was prepared by dispersion of radiolabeled clindamycin in carbopol 980 containing polaxomer as surfactant and methyl paraben as preservative solution. The prepared hydrogel was analysed for in vitro analysis via franz diffusion cell and in vivo studies were performed in balb-C mice for biodistribution and skin permeation and were analysed by radiometry. The results obtained showed labeling efficiency of clindamycin was more than 90%, and that was consistent and the radiolabeled drug was stable upto 24 hrs in serum. In vitro release studies showed an increased release rate till four hours and it's become plateaus after 4 hours. In vivo biodistribution studies were showed 99m Tc clindamycin hydrogel remains stable and follow predominantly hepatic excretion. Biodistribution pattern suggests late redistribution from a storage sight, probably, body fats

Unexplained infertility: identification of anti sperm antibodies using radiometric immunoassay

International Nuclear Information System (INIS)

Megahed, Y.M.; Elnabarawy, F.; Hamada, T.; Ayiad, S.K.

1992-01-01

Several methods have been employed to measure anti sperm antibodies with variable sensitivity and specificity in serum and secretion of infertile patients. All of them are not precise means for identification of the presence of anti sperm antibodies for patients with unexplained infertility (Haas et al, 1980). Therefore, the modified radiolabelled anti globulin test, that has been used successfully to identify and quantitate the antibodies directed towards other human cell surfaces, was applied. A total number of 128 subjects in different groups were studied to quantitate the circulating anti sperm antibodies using the modified procedure. The present data revealed that the highest and the most significant incidence were found in the patients secretions (semen and cervical mucus) with unexplained infertility, as well as in the group of males with varicocele. Therefore it is greatly advisable to use the modified radiolabelled technique as a quantitative assay, which will be helpful in management of infertility in patients with unexplained and mediated infertility.3 tab., 4 fig

Tumor imaging with monoclonal antibodies

International Nuclear Information System (INIS)

Haisma, H.; Hilgers, J.

1987-01-01

Many monoclonal antibodies directed against tumor-associated antigens have been identified, but so far none of these are tumor specific. Polyclonal and monoclonal antibodies have been used for imaging of a wide variety of tumors with success. Radiolabeling of antibody is usually done with iodine isotopes of which 123 I is the best candidate for radioimmunodetection purposes. The labeling of antibodies through chelates makes it possible to use metal radioisotopes like 111 In, which is the best radioisotope for imaging with monoclonal antibodies due to its favorable half-life of 2.5 days. Usually imaging cannot be performed within 24 h after injection, but clearance of antibody can be increased by using F(ab) 2 of Fab. Another approach is to clear non-bound antibody by a second antibody, directed against the first. The detection limit of immunoimaging is about 2 cm, but will be improved by tomography or SPECT. There is still a high false positive and false negative rate, which makes it impossible to use radioimmunodetection as the only technique for diagnosis of tumors. In combination with other detection techniques, tumor imaging with monoclonal antibodies can improve diagnosis. 44 refs.; 3 tabs

Country report: Vietnam. Setting Up of a 90Sr/90Y Generator System Based on Supported Liquid Membrane (SLM) Technique and Radiolabeling of Eluted 90Y with Biomolecules

International Nuclear Information System (INIS)

Nguyen Thi Thu; Duong Van Dong; Bui Van Cuong; Chu Van Khoa

2010-01-01

In the course of participating in the IAEA-CRP during the last two years, Vietnam has achieved the goal of setting up a 90 Sr/ 90 Y generator system based on Supported Liquid Membrane (SLM) technique and also radiolabeling of the eluted 90 Y with antibody, peptides and albumin. A two stage SLM based 90 Sr- 90 Y generator was set up in-house to generate carrier-free 90 Y at different activity levels viz. 5, 20, 50 mCi. The generator system was operated in sequential mode in which 2-ethylhexyl 2-ethylhexyl phosphonic acid (PC88A) based SLM was used in the first stage for the transport 90 Y in 4.0 M nitric acid from source phase where 90 Sr- 90 Y equilibrium mixture is placed in nitric acid medium at pH to 1-2. In the second stage, octyl (phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) based SLM was used for the transport of 90 Y selectively to 1.0 M acetic acid which is the best medium for radiolebeling. The eluted 90 Y from the generator was tested for the presence of any traces of 90 Sr using the Extraction Paper Chromatography (EPC) and was found suitable for radiolabeling. The generator system could be upgraded to 100 mCi level successfully due to an expert mission from India through IAEA. The 90 Y product obtained from the generator system was used for radiolabeling of antibody and peptides viz. Rituximab, DOTATATE and albumin particles under different experimental conditions. A new chromatography system could be developed for analyzing 90 Y labeled albumin using the TAE buffer as mobile phase in PC and ITLC

Radiolabelled blood cells

Energy Technology Data Exchange (ETDEWEB)

Lavender, J.P.

1986-12-01

After the introduction of gamma-emitting labels for blood-cells the use of radio-labelled blood cells is not only limited to kinetics of blood cells but it is also possible to localise inflammations, abscesses and thrombus. The most commonly applied label for red cells is Tc-99m. The most widely used technique for labelling granulocytes or platelets is In-111-oxine. In future the labelling of blood cells will be more simple and more specific due to monoclonal antibodies onto the platelet or the granulocyte cell surface. Labelled red cells have their main application in blood-pool imaging and in localisation of gastrointestinal bleeding. Besides the determination of the platelet life-span in haematologic disorders labelled platelets allow to localise thrombus and to show abnormal vasculature in the rejecting kidney. The commonest application for In-111-oxin labelled granulocytes is to show abdominal inflammations to localise inflamed bowel segments and to assess the inflammatory activity in chronic inflammatory bowel diseases. Moreover brain abscesses, bone sepsis and lung sepsis can be identified.

Pharmacokinetics and biodistribution of radiolabeled avidin, streptavidin and biotin

International Nuclear Information System (INIS)

Rosebrough, S.F.

1993-01-01

The extraordinarily high affinity of avidin and streptavidin for biotin may be exploited in a two-step approach for delivering radiolabeled biotin derivatives suitable for imaging and therapy to target-bound streptavidin or avidin conjugated monoclonal antibodies (MAbs). The in vivo pharmacokinetics and biodistribution of radiolabeled avidin, streptavidin (SA) and DTPA-biocytinamide (DTPA-biotin) were studied in the rabbit and dog. SA circulated in the blood similar to other 60 kDa proteins, avidin cleared immediately and DTPA-biotin exhibited plasma clearance by glomerular filtration. (author)

Characterization of Tumor-Avid Antibody Fragments Genetically Engineered for Mono-Specific Radionuclide Chelation

International Nuclear Information System (INIS)

Quinn, T.P.

2003-01-01

The successful clinical application of targeted-radiopharmaceuticals depends on the development of molecules that optimize tumor specific radionuclide deposition and minimize non-specific organ irradiation. To this end, this proposal outlines a research effort to identify and evaluate novel antibodies and antibody fragments that bind breast tumors. The tumor-avid antibodies will be investigated for as imaging and therapeutic agents and to gain a better understanding of the pharmacokinetics and metabolism of radiolabeled tumor-avid antibody fragments through the use of site-specifically labeled molecules. Antibodies or antibody fragments, that bind breast carcinoma carbohydrate antigens, will be obtained from hybridoma or bacteriophage library screening. More specifically, antibody fragments that bind the carcinoma-associated Thomsen-Friedenreich (T) antigen will be radiolabeled with 99m Tc and 188 Re at a natural amino acid chelation site and will be investigated in vivo for their abilities to target human breast tumors. In addition, site-specific radiolabeled antibody fragments will be biosynthesized using misacylated suppressor tRNAs. Homogeneously radiolabeled populations of antibody fragments will be used to investigate the effects of radionuclide location and chelation chemistries on their biodistribution and metabolism. It is hypothesized that site-specifically radiolabeled antibody fragments will possess enhanced tumor imaging and therapeutic properties due to optimal label location and conjugation chemistries. New insights into the factors that govern antibody metabolism in vivo are also expected from this work. Results from these studies should enhance our ability to design and synthesize radiolabeled antibody fragments that have improved pharmacokinetic properties. The studies in this proposal involve basic research into the development of antibody-based radiopharmaceuticals, with the ultimate goal of application in humans. This type of basic nuclear

Method of stably radiolabeling antibodies with technetium and rhenium

International Nuclear Information System (INIS)

Paik, C.H.; Reba, R.C.; Eckelman, W.C.

1987-01-01

A method is described for labeling antibodies or antibody fragments with radionuclides of technetium or rhenium to obtain stable labeling, comprising: reacting a reduced radioisotope of technetium or rhenium with an antibody or antibody fragment, or a diethylenetriaminepentaacetic acid conjugated antibody or antibody fragment, in the presence of free or carrier-bound diethylenetriaminepentaacetic acid (DTPA). The amount of DTPA is sufficient to substantially completely inhibit binding of the reduced technetium or rhenium to nonstable binding sites of the antibody or antibody fragment, or the DTPA-conjugated antibody or antibody fragment. The resultant stably labeled antibody or antibody fragment, or DTPA[conjugated antibody or antibody fragment is recovered

C-kit-targeted imaging of gastrointestinal stromal tumor using radiolabeled anti-c-kit monoclonal antibody in a mouse tumor model

International Nuclear Information System (INIS)

Sogawa, Chizuru; Tsuji, Atsushi B.; Sudo, Hitomi; Sugyo, Aya; Yoshida, Chisato; Odaka, Kenichi; Uehara, Tomoya; Arano, Yasushi; Koizumi, Mitsuru; Saga, Tsuneo

2010-01-01

Introduction: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor arising from the gastrointestinal tract and highly expresses mutated c-kit. We aimed to develop a specific and sensitive method for detecting GISTs using radiolabeled anti-c-kit monoclonal antibody. Methods: A mutated c-kit-expressing cell clone was established by transfecting an expressing vector of mutated c-kit gene into HEK293 human embryonic kidney cells. The tumors were developed by inoculating c-kit-expressing cells into nude mice. 125 I- and 111 In-labeled anti-c-kit antibodies (12A8 and 41A11) were evaluated in vitro by cell binding, competitive inhibition and cellular internalization assays, and in vivo by biodistribution and imaging studies in tumor-bearing mice. Results: Both 125 I- and 111 In-labeled antibodies showed specific binding with c-kit-expressing cells with high affinity (dissociation constants = 2.2-7.1x10 9 M -1 ). Internalization assay showed that 125 I-labeled antibodies were rapidly internalized and dehalogenated, with the release of 125 I from the cells, resulting in reduction of cell-associated radioactivity with time. In contrast, 111 In-labeled antibody was internalized but did not result in the reduced radioactivity associated with tumor cells. Reflecting this phenomenon, the in vivo tumor uptake of 125 I-labeled antibody was low on Day 1, further decreasing with time, while tumor uptake of 111 In-labeled antibody was high on Day 1, further increasing with time. The xenografted tumor was clearly visualized by scintigraphy after injection of 111 In-labeled antibody. Conclusion: The anti-c-kit monoclonal antibody labeled with a metal radionuclide would be promising for c-kit-targeted imaging of GISTs.

Country report: Vietnam. Setting Up of a {sup 90}Sr/{sup 90}Y Generator System Based on Supported Liquid Membrane (SLM) Technique and Radiolabeling of Eluted {sup 90}Y with Biomolecules

Energy Technology Data Exchange (ETDEWEB)

Thu, Nguyen Thi; Dong, Duong Van; Cuong, Bui Van; Khoa, Chu Van [Vietnam Atomic Energy Commission (VAEC), Nuclear Research Institute, Dalat (Viet Nam)

2010-07-01

In the course of participating in the IAEA-CRP during the last two years, Vietnam has achieved the goal of setting up a {sup 90}Sr/{sup 90}Y generator system based on Supported Liquid Membrane (SLM) technique and also radiolabeling of the eluted {sup 90}Y with antibody, peptides and albumin. A two stage SLM based {sup 90}Sr-{sup 90}Y generator was set up in-house to generate carrier-free {sup 90}Y at different activity levels viz. 5, 20, 50 mCi. The generator system was operated in sequential mode in which 2-ethylhexyl 2-ethylhexyl phosphonic acid (PC88A) based SLM was used in the first stage for the transport {sup 90}Y in 4.0 M nitric acid from source phase where {sup 90}Sr-{sup 90}Y equilibrium mixture is placed in nitric acid medium at pH to 1-2. In the second stage, octyl (phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) based SLM was used for the transport of {sup 90}Y selectively to 1.0 M acetic acid which is the best medium for radiolebeling. The eluted {sup 90}Y from the generator was tested for the presence of any traces of {sup 90}Sr using the Extraction Paper Chromatography (EPC) and was found suitable for radiolabeling. The generator system could be upgraded to 100 mCi level successfully due to an expert mission from India through IAEA. The {sup 90}Y product obtained from the generator system was used for radiolabeling of antibody and peptides viz. Rituximab, DOTATATE and albumin particles under different experimental conditions. A new chromatography system could be developed for analyzing {sup 90}Y labeled albumin using the TAE buffer as mobile phase in PC and ITLC.

A review: radiolabeled synthesis of pesticides

International Nuclear Information System (INIS)

Li Juying; Han Ailiang; Wang Haiyan; Wang Wei; Ye Qingfu

2010-01-01

Isotope tracer technique has been widely applied in studies of metabolism, mode action, fate and environmental behavior of pesticides. In such studies, the key point is to obtain suitable radiolabelled compounds. However, the radiotracers, especially the labelled pesticides which are novel compounds with complex structures and longer synthesis routes, are usually unavailable from domestic and /or foreign markets. Therefore, it is essential to explore the synthesis methods of radiolabelled pesticides, which are quite different from the conventional nonradiosynthesis, and are requested to obtain higher yield. This article is a review on current status of choosing the available radionuclide and labelled position, the main synthesis methods and problems in the process of preparing radiolabelled pesticides. (authors)

Immunoscintigraphy of metastases with radiolabelled human antibodies

Energy Technology Data Exchange (ETDEWEB)

Al-Azzawi, F.; Smith, J.; Stimson, W.H.

1987-02-28

It was concluded that Epstein-Barr virus transformation of committed lymphocytes offers great potential in the production of antitumour antibodies of human origin. An outline case report is presented where the human I/sup 131/ labelled antibody was used as a targeting agent to delineate the extent of secondary growth in the liver. (U.K.).

Composition and method for detecting cancer with technetium labeled antibody fragments

International Nuclear Information System (INIS)

Burchiel, S. W.; Crockford, D. R.; Rhodes, B. A.

1984-01-01

F(ab') 2 or Fab fragments of antibodies to: (a) human chorionic gonadotropin (hCG), hCG alpha subunit, hCG beta subunit, or an hCG-like material; or (b) other tumor specific or tumor associated molecules, to include carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), human melanoma associated antigens, human sarcoma associated antigens or other antigens, are radiolabeled with technetium-99m (Tc-99m). When the F(ab') 2 or Fab fragments of antibody to such tumor associated antigens are injected intravenously into a patient, the radiolabeled composition accumulates at tumor sites. The accumulation of the cancer seeking radiopharmaceutical at tumor sites permits detection by external gamma scintigraphy. Thus, the composition is useful in the monitoring, localization and detection of cancer in the body. In an alternative composition, a double antibody approach to tumor localization using radiolabeled F(ab') 2 or Fab fragments is utilized. In this approach, a tumor specific antibody in the form of IgG, F(ab') 2 or Fab is first administered to a patient intravenously. Following a sufficient period of time, a second antibody in the form of F(ab') 2 or Fab is administered. The second antibody is radiolabeled with Tc-99m and has the property that it is reactive with the first antibody. This double antibody method has the advantage over a single antibody approach in that smaller tumors can be localized and detected and that the total amount of radioactive trace localized at the cancer site is increased

Anti-transferrin receptor antibody and antibody-drug conjugates cross the blood-brain barrier

International Nuclear Information System (INIS)

Friden, P.M.; Walus, L.R.; Musso, G.F.; Taylor, M.A.; Malfroy, B.; Starzyk, R.M.

1991-01-01

Delivery of nonlipophilic drugs to the brain is hindered by the tightly apposed capillary endothelial cells that make up the blood-brain barrier. The authors have examined the ability of a monoclonal antibody (OX-26), which recognizes the rat transferrin receptor, to function as a carrier for the delivery of drugs across the blood-brain barrier. This antibody, which was previously shown to bind preferentially to capillary endothelial cells in the brain after intravenous administration, labels the entire cerebrovascular bed in a dose-dependent manner. The initially uniform labeling of brain capillaries becomes extremely punctate ∼ 4 hr after injection, suggesting a time-dependent sequestering of the antibody. Capillary-depletion experiments, in which the brain is separated into capillary and parenchymal fractions, show a time-dependent migration of radiolabeled antibody from the capillaries into the brain parenchyma, which is consistent with the transcytosis of compounds across the blood-brain barrier. Antibody-methotrexate conjugates were tested in vivo to assess the carrier ability of this antibody. Immunohistochemical staining for either component of an OX-26-methotrexate conjugate revealed patterns of cerebrovascular labeling identical to those observed with the unaltered antibody. Accumulation of radiolabeled methotrexate in the brain parenchyma is greatly enhanced when the drug is conjugated to OX-26

Anti-CD20 Immunoglobulin G Radiolabeling with a 99mTc-Tricarbonyl Core: In Vitro and In Vivo Evaluations.

Directory of Open Access Journals (Sweden)

Hélène Carpenet

Full Text Available In recent years, the diagnostic and therapeutic uses of radioisotopes have shown significant progress. Immunoglobulin (Ig appears to be a promising tracer, particularly due to its ability to target selected antigens. The main objective of this study is to optimize and assess an Ig radiolabeling method with Technetium 99m (99mTc, an attractive radioelement used widely for diagnostic imaging. Monoclonal anti-CD20 IgG was retained to study in vitro and in vivo radiolabeling impact. After IgG derivatization with 2-iminothiolane, IgG-SH was radiolabeled by an indirect method, using a 99mTc-tricarbonyl core. Radiolabeling stability was evaluated over 24h by thin-layer chromatography. IgG integrity was checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis coupled with Western blot and autoradiography. The radiolabeled Ig's immunoaffinity was assessed in vitro by a radioimmunoassay method and binding experiments with cells (EL4-hCD20 and EL4-WT. Biodistribution studies were performed in normal BALB/c mice. Tumor uptake was assessed in mice bearing EL4-hCD20 and EL4-WT subcutaneous xenografts. With optimized method, high radiolabeling yields were obtained (95.9 ± 3.5%. 99mTc-IgG-SH was stable in phosphate-buffered saline (4°C and 25°C and in serum (37°C, even if important sensitivity to transchelation was observed. IgG was not degraded by derivatization and radiolabeling, as shown by Western blot and autoradiography results. 99mTc-anti-CD20 IgG-SH immunoaffinity was estimated with Kd = 35 nM by both methods. In vivo biodistribution studies for 48h showed significant accumulation of radioactivity in plasma, liver, spleen, lungs and kidneys. Planar scintigraphy of mice bearing tumors showed a significant uptake of 99mTc-anti-CD20 IgG-SH in CD20+ tumor versus CD20- tumor. Radiolabeling of derivatized IgG with 99mTc-tricarbonyl was effective, stable and required few antibody amounts. This attractive radiolabeling method is "antibody safe

Timothy-specific IgG antibody levels vary with the pollen seasons.

Science.gov (United States)

Nordvall, S L; Larsson, P H; Johansson, S G

1986-11-01

Serum samples were collected from eight grass pollen hypersensitive children during a 4-year period. The sera were assayed for contents of timothy-specific IgE antibodies by RAST. Timothy-specific IgG and IgA antibodies were quantified by a refined ELISA in which covalent binding of the antigen to the polystyrene solid phase had been performed. IgG antibodies were also assayed by a Sepharose-protein-A technique with radiolabelled timothy allergens as the antigen. It was possible to register clearcut seasonal variations with postseasonally boosted antibody levels not only of timothy-specific IgE but also of IgG antibody. Both IgG1 and IgG4 antibodies specific for timothy showed seasonal variations of a similar degree. It was not possible to register seasonal variations of the same magnitude of timothy-specific IgA antibodies.

New tools for immunochemistry: internally labelled monoclonal antibodies

International Nuclear Information System (INIS)

Galfre, G.; Cuello, A.C.

1981-01-01

Labelled antibodies are routinely used in a wide variety of immunochemical methods. Over the years several labelling techniques have been developed and the discussion of some of them forms a substantial part of this course. Common to all the procedures is the need to purify the antibodies. The labelling itself consists of coupling the antibodies to a ''label'' molecule by means of a chemical reaction. Preparation in vitro of monoclonal antibodies offers the unique possibility to internally label them. Although this is restricted to radiolabelling, and the specific activity achieved is limited, the procedure is extremely simple, does not require purification prior to labelling and chemical manipulation is not necessary as the antibodies themselves are synthesized from radioactive amino acids. Moreover, different labels can be used ( 14 C, 35 S, 3 H) which have a much longer half-life than 125 I. The choice of labelled amino acid precurors and labelling procedure is discussed. The uses of internally-labelled monoclonal antibodies are indicated. (Auth.)

In vitro measurement of avidity of radioiodinated antibodies

International Nuclear Information System (INIS)

Badger, C.C.; Krohn, K.A.; Bernstein, I.D.

1987-01-01

A determination of the ability of radiolabeled antibodies to bind to their target antigen is an essential step in the initial selection of antibodies for clinical use as well as a quality control measure. In our studies of the 131 I-labeled anti-Thy 1.1 antibody treatment of murine lymphoma, we have used cell binding assays with a combination of Lineweaver-Burk analysis to determine immunoreactivity and Scatchard analysis to determine antibody avidity. Both assays were systematically influenced by target cell fixation and measurement of avidity was dependent on immunoreactivity. For 131 I-labeled anti-Thy 1.1 antibody, avidity was a much more sensitive indicator of iodination damage and predictor of in vivo behavior than was immunoreactivity, while for other antibodies immunoreactivity has been a better indicator of labeling damage. Thus, immunoreactivity and avidity assays are complementary and knowledge of both factors is required for the design of sensitive quality control procedures for radiolabeled antibodies. (author)

Improvement of A.E.S System, using a 188Re-radiolabeled hapten

International Nuclear Information System (INIS)

Morandeau, L.

2002-01-01

Full text: Feasibility of two-step radioimmunotherapy (RIT) of cancer by the Affinity Enhancement System (AES) has been demonstrated in experimental and clinical studies. This technique, associating a bispecific antibody (BsAb) and a radiolabeled bivalent peptide, reduces toxicity and improves therapeutic efficacy of the treatment compared to the one step targeting method. The formation of a cyclic complex (antigen-BsAb- hapten-BsAb-antigen) observed on the tumor allows good tumoral fixation. This is associated with low non-specific uptake, due to the fast clearance of the hapten from the organism. Iodine 131, used currently in clinical applications, has however several disadvantages. These include the mean energy of □ . particles, strong y emission and long physical half-life. Rhenium-188 is the radionuclide of choice to replace iodine-131; its low cost, its availability from a W-188/Re-188 generator and its very favorable radiophysical properties (t 1/2 =16.9h; E□=2.118 MeV; Ey (15%)=155keV) make it a very interesting radionuclide for radioimmunotherapy applications. Unlike the case of iodine-131, the radiolabelling of the peptide by rhenium-188 requires the preliminary coupling of a bifunctional chelating agent. This ensures the formation of an in vivo stable complex with the radionuclide. The object of this post-doctoral project is to obtain a rhenium-188 radiolabeled bivalent hapten. To do this, a monovalent hapten will be coupled to a chelating agent that involves two or three patterns to complex the radionuclide, leading to a bivalent or trivalent radiolabeled hapten, suitable for applications in A.E.S. system. The monovalent hapten used, called HSGL (histaminosuccinylglycyllysine) is a small heteropeptide composed of a chain of four molecules which are histamine, succinic acid, glycine, lysine. It is recognised by the antibody anti-HSG. Two kinds of chelating agents, dithiocarbamates and dithiobenzoates will be studied. They have been synthesised at

Labeling and stability of radiolabeled antibody fragments by a direct 99mTc-labeling method

International Nuclear Information System (INIS)

Pak, K.Y.; Nedelman, M.A.; Tam, S.H.; Wilson, E.; Daddona, P.E.

1992-01-01

The in vitro labeling and stability of 99m Tc-labeled antibody Fab' fragments prepared by a direct labeling technique were evaluated. Eight antibody fragments derived from murine IgG1 (N = 5), IgG2a (N = 2) and IgG3 (N = 1) isotypes were labeled with a preformed 99m Tc-D-glucarate complex. No loss of radioactivity incorporation was observed for all the 99m Tc-labeled antibody fragments after 24 h incubation at 37 o C. 99m Tc-labeled antibody fragments (IgG1, N = 2; IgG2a, n = 2; IgG3, N = 1) were stable upon challenge with DTPA, EDTA or acidic pH. Using the affinity chromatography technique, two of the 99m Tc-labeled antibody fragments displayed no loss of immunoreactivity after prolonged incubation in phosphate buffer up to 24 h at 37 o C. Bonding between 99m Tc and antibody fragments was elucidated by challenging with a diamide ditholate (N 2 S 2 ) compound. The Fab' with IgG2a isotype displayed tighter binding to 99m Tc in comparison to Fab' from IgG1 and IgG3 isotype in N 2 S 2 challenge and incubation with human plasma. The in vivo biodistribution of five 99m Tc-labeled fragments were evaluated in normal mice. (Author)

In vivo VEGF imaging with radiolabeled bevacizumab in a human ovarian tumor xenograft

NARCIS (Netherlands)

Nagengast, Wouter B.; Hospers, Geke A.; Mulder, Nanno H.; de Jong, Johan R.; Hollema, Harry; Brouwers, Adrienne H.; van Dongen, Guns A.; Perk, Lars R.; Lub-de Hooge, Marjolijn N.

Vascular endothelial growth factor (VEGF), released by tumor cells, is an important growth factor in tumor angiogenesis. The humanized monoclonal antibody bevacizumab blocks VEGF-induced tumor angiogenesis by binding, thereby neutralizing VEGF. Our aim was to develop radiolabeled bevacizumab for

Experimental study of capacity of the blood blow of spinal cord using radiolabelling microspbere technique

International Nuclear Information System (INIS)

Hu Xuan; Li Rui

2007-01-01

Objective In order to study the relation ship between local blood flow and neurofunction at the later stage of spinal injury. Method: Measured the capacity of the local blood flow in the spinal cord injury by the radiolabelling microsphere technique and scored the nervus function grade. Result: There are no correlation between the local blood flow and the nervus function. Conclusion: It is obvious that the increase of the local blood supply can't reflect the nervus function. (authors)

Making Recombinant Monoclonal Antibody And Radiolabelling For Medical Purpose

International Nuclear Information System (INIS)

Nguyen Thi Thu; Duong Van Dong; Vo Thi Cam Hoa; Bui Van Cuong; Chu Van Khoa; Vu Bich Huong; Le Quang Huan

2008-01-01

Recombinant monoclonal antibody labeling with 131 I specific to tumor cell has been studied and prepared for treatment of Hodgkin lymphoma. In this study, a recombinant monoclonal antibody with two specific properties is a hybrid molecule created by coupling an antibody variable fragments with peptide melittin. The gene coding the antibody fragment has been obtained from human synthetic Fv libraries using for panning and screening on populations of lymphocytes fragmented from human blood cells with Hodgkin diseases. The gene encoding peptit melittin has been cloned from honeybee Apis cerana DNA. The gene coding recombinant monoclonal antibody has been expressed in E.coli BL21 (DE3) at 37 o C and was induced with 0.6 mM IPTG. The recombinant compound has been purified by affinity chromatography with HiTrap affinity column. The obtained recombinant monoclonal antibody has showed cytolytic activities when added to cell culture medium for LU cancer cell line with the amount of 100 - 200 mg/ml. This monoclonal antibody is labeled with 131 I using chloramine T procedure. ChT mass for the oxidation of 50 μg monoclonal antibody in 76 MBq was 10 μg. Sodium metabisulfite was used as a reducing agent. Reaction time was above 3 mins. The radiochemical purity was determined using electrophoresis and TLC methods. Radiochemical yield was > 97%. Radiochemical purity after purification was > 99%. Nuclear purity was > 99%. Stability of the label antibody was 12 days. This is the product promise potential used in the diagnostic and therapeutic of Hodgkin lymphoma. (author)

Development of Radiolabeled compounds using reactor-produced radionuclides

International Nuclear Information System (INIS)

Choi, Sun Ju; Park, K. B.; Park, S. H.

2007-06-01

To establish a robust technology for radiopharmaceutical development, we focused on the configuration of fundamental development of radiolabeled compounds for radioimmunotherapy and drug delivery as well as the development of bifunctional chelating agents and radiolabeling methods for the radiopharmaceuticals with highly specific activity to deliver sufficient number of radionuclides to the target site. In this project, we aim to improve the quality of life and the public welfare by fostering the medical application of radioisotopes for the effective treatment of malignant diseases and by developing efficient radiolabeling methods of specific bio-active materials with radioisotopes and new candidates for radiopharmaceutical application. We have established the procedure for the preparation of radiolabeled antibody and biotin with radioisotopes such as 166 Ho, 131 I, 90 Y and 111 In for tumour targeting. In the future, these technologies will be applicable to development of radioimmunotherapeutic drug. The combination treatment of radioisotope with anti-cancer agents or chemotherapeutic agents may produce a synergistic static effects in the tumour and this synergism would be exerted via gene level through the activation of a cell death pathway. The combination therapy may be very beneficial for cancer treatment and this can overcome not only the hazards of unnecessary exposure to high radiation level during therapy, but also the tendency for drug resistance caused by chemotherapy. To develop new drug delivery system suitable for CT imaging agent, a chitosan derivative and radiolabed Folate-targeted polymer with 131 I were synthesized. We also carried out the development of DTPA derivatives for CT imaging agent, radiolabeled precursor, and established a highly efficient radiolabeling methodology with lanthanide nuclide. In order to develop neuroreceptor targeting compounds, we synthesized WAY-100635 compound and 99m Tc(CO) 3 precursor from Chrysamine G derivatives

Three-site sandwich radioimmunoassay with monoclonal antibodies for a sensitive determination of human alpha-fetoprotein

International Nuclear Information System (INIS)

Nomura, M.; Imai, M.; Takahashi, K.; Kumakura, T.; Tachibana, K.; Aoyagi, S.; Usuda, S.; Nakamura, T.; Miyakawa, Y.; Mayumi, M.

1983-01-01

Utilizing monoclonal antibodies against human alpha-fetoprotein, 3 distinct antigenic determinants were identified. These antigenic determinants, provisionally designated a, b and c, were arranged in such a manner that the binding of one determinant with the corresponding antibody did not inhibit, or only barely inhibited the binding of antibodies directed to the other 2 determinants. Monoclonal antibodies with 3 different specificities were, therefore, applied to develop a sandwich-type solid-phase radioimmunoassay of the antigen in which wells were coated with anti-a, and radiolabeled anti-b together with radiolabeled anti-c was employed to detect the bound antigen. The 3-site sandwich radioimmunoassay involving 3 different determinants gave a higher sensitivity than 2-site assays in which only anti-b or anti-c was employed as a radiolabeled reagent, because the radioactivity of the 2 labeled antibodies was added on the antigen bound to immobilized anti-a. (Auth.)

Bispecific Antibody Pretargeting for Improving Cancer Imaging and Therapy

Energy Technology Data Exchange (ETDEWEB)

Sharkey, Robert M.

2005-02-04

The main objective of this project was to evaluate pretargeting systems that use a bispecific antibody (bsMAb) to improve the detection and treatment of cancer. A bsMAb has specificity to a tumor antigen, which is used to bind the tumor, while the other specificity is to a peptide that can be radiolabeled. Pretargeting is the process by which the unlabeled bsMAb is given first, and after a sufficient time (1-2 days) is given for it to localize in the tumor and clear from the blood, a small molecular weight radiolabeled peptide is given. According to a dynamic imaging study using a 99mTc-labeled peptide, the radiolabeled peptide localizes in the tumor in less than 1 hour, with > 80% of it clearing from the blood and body within this same time. Tumor/nontumor targeting ratios that are nearly 50 times better than that with a directly radiolabeled Fab fragment have been observed (Sharkey et al., ''Signal amplification in molecular imaging by a multivalent bispecific nanobody'' submitted). The bsMAbs used in this project have been composed of 3 antibodies that will target antigens found in colorectal and pancreatic cancers (CEA, CSAp, and MUC1). For the ''peptide binding moiety'' of the bsMAb, we initially examined an antibody directed to DOTA, but subsequently focused on another antibody directed against a novel compound, HSG (histamine-succinyl-glycine).

Current status and future developments in radiolabelled immunoassays

International Nuclear Information System (INIS)

Edwards, R.

1998-01-01

Radioisotopes are used extensively in medical practice and their use in RIA or IRMA usually represent a small proportion of the total. Radiolabelled immunoassays based on 125 I constitute a simple didactic, cost effective and robust technology which is still regarded as the reference method in many clinical applications. The IAEA has implemented many successful programmes using the ''bulk reagent'' approach, involving 68 countries in all the different regions. The main achievements have been in technology transfer with self sufficiency in production for some countries; training of large numbers of staff; quality control and quality assurance schemes; devolution of screening programmes for neonatal congenital hypothryoidism. Alternatives to the use of radioisotopic tracers are constrained by many factors and are often only available in restricted commercial packages. They are often not suitable for technology transfer programmes and often lack any didactic component in addition to a relative high cost. The production of radiolabels using 125 I is both simple and adaptable. In addition expertise in their preparation and purification is widespread even in developing countries. Together with the ease of producing antibodies, the facts have made 125 I-radiolabelled immunoassays ideal for investigative procedures for many research activities (30,31) particularly in the medical context where radioisotopes are commonly used. In conclusion, even a superficial examination of public health statistics for various countries throughout the continents indicates a need for a simple, inexpensive and robust analytical tool. In this light, there is a predicted continuing role for radiolabelled immunoassays. (author)

99mTc-rituximab radiolabelled by photo-activation: a new non-Hodgkin's lymphoma imaging agent

International Nuclear Information System (INIS)

Gmeiner Stopar, T.; Fettich, J.; Hojker, S.; Mlinaric-Rascan, I.; Mather, S.J.

2006-01-01

Rituximab was the first chimeric monoclonal antibody to be approved for treatment of indolent B-cell non-Hodgkin's lymphoma (NHL). It is directed against the CD20 antigen, which is expressed by 95% of B-cell NHLs. The aim of this study was to explore the possibility of radiolabelling rituximab with 99m Tc for use as an imaging agent in NHL for early detection, staging, remission assessment, monitoring for metastatic spread and tumour recurrence, and assessment of CD20 expression prior to (radio)immunotherapy. Rituximab was purified from Mabthera solution (Roche), photo-activated at 302 nm by UV irradiation and radiolabelled with 99m Tc. The effectiveness of the labelling method was evaluated by determination of the number of free thiol groups per photoreduced antibody, radiochemical purity and in vitro stability of 99m Tc-rituximab. On average, 4.4 free thiol groups per photoreduced antibody were determined. Radiolabelling yields greater than 95% were routinely observed after storage of the photo-activated antibody at -80 C for 195 days. The direct binding assay showed preserved ability of 99m Tc-rituximab to bind to CD20, with an average immunoreactive fraction of 93.3%. The internalisation rate was proven to be low, with only 5.3% of bound 99m Tc-rituximab being internalised over 4 h at 37 C. Our results demonstrate that 99m Tc-rituximab of high radiochemical purity and with preserved binding affinity for the antigen can be prepared by photoreduction and that the method shows good reproducibility. 99m Tc-rituximab will be further explored as an imaging agent applicable in NHL for the purposes mentioned above. (orig.)

Comparison of the chemical behaviour of humanized ACMS VS. Human IGG radiolabeled with 99mTc

International Nuclear Information System (INIS)

Rivero Santamaria, Alejandro; Zayas Crespo, Francisco; Mesa Duennas, Niurka; Castillo Vitloch, Adolfo J.

2003-01-01

The purpose of this work is to compare the chemical behaviour of humanized AcMs vs. human IgG radiolabeled with 99 mTc. to this end, 3 immunoglobulins were analyzed, the IgG (human), the humanized monoclonal antibody R3 (Acm-R3h) and the humanized monoclonal antibody T1. The results obtained reveal slight differences as regards the behaviour of theses immunoglobulins before the labelling with 99T c, which shows differences in the chemical behaviour of these proteins. Although in theory the modifications that are made to the AcMs in order to humanize them must not affect their chemical behaviour, the obtained data indicate that the conditions for their radiolabelling should not be extrapolated from other proteins; on the contrary, particular procedures should be elaborated for each AcM-h

The preparation and use of radiolabelled specific helminth antibodies

International Nuclear Information System (INIS)

Movsesijan, M.; Jovanovic, B.; Borojevic, D.; Petrovic, M.

1983-01-01

Specific antibodies from the serum of sheep infected with Haemonchus contortus were isolated by combination with a ''solid phase antigen'' (soluble antigen coupled to an activated crystalline cellulose). The antibodies were labelled with 125 I while bound to the solid phase then eluted and their potential demonstrated: (1) to determine amounts of specific antibody in unknown sera; (2) to determine amounts of soluble antigen in unknown preparations. (author)

Immunoradiometric assay for cytomegalovirus-specific IgG antibodies

International Nuclear Information System (INIS)

Klapper, P.E.; Cleator, G.M.; Prinja-Wolks, D.; Morris, D.J.

1990-01-01

An immunoradiometric assay (radio-immunosorbent test; RIST) for the detection of IgG antibodies to human herpesvirus 4 [human cytomegalovirus (CMV)] has been developed. The technique utilizes CMV antigen passively adsorbed to a polyvinyl microtitration plate and a radiolabelled murine monoclonal anti-human IgG antibody to detect binding of human antibody to the 'solid phase' reagent. The assay was optimized, and its specifity confirmed by testing paired acute and convalescent sera from patients with acute CMV or other human herpesvirus infections. To determine the assay's sensitivity 1433 blood donor sera were examined. The RIST was more sensitive than a standard complement fixation (CFT). Use of a monoclonal anti-human IgG antibody in the RIST reduced non-specific binding to the control uninfected cell antigen such that blood donor sera could be tested in the assay using only a CMV antigen without generating an unacceptable false positive rate. (author). 23 refs.; 1 tab

Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

Science.gov (United States)

Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

2015-01-01

CONSPECTUS Positron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector. We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of nanoparticles, as well as adjusting the labeling strategies according to specific applications. We classified these radiolabeling methods into four categories: (1) complexation reaction of radiometal ions with chelators via coordination chemistry; (2) direct bombardment of nanoparticles via hadronic projectiles; (3) synthesis of nanoparticles using a mixture of radioactive and nonradioactive precursors; (4) chelator-free postsynthetic radiolabeling. Method 1 is generally applicable to different nanomaterials as long as the surface chemistry is well-designed. However, the addition of chelators brings concerns of possible changes to the physicochemical properties of nanomaterials and detachment of the radiometal. Methods 2 and 3 have improved radiochemical stability. The applications are, however, limited by the possible damage to the nanocomponent caused by the proton beams (method 2) and harsh synthetic conditions (method 3). Method 4 is still in its infancy

Quantitation of radiolabeled compounds eluting from the HPLC system

International Nuclear Information System (INIS)

Kessler, M.J.

1982-01-01

Three techniques are compared for the quantitation of various radiolabeled compounds eluting in the high performance liquid chromatography system. The first technique requires fraction-collecting the effluent from the HPLC, removing an aliquot to scintillation vials, and counting each fraction in a liquid scintillation counter. The second uses direct interface of the HPLC effluent to a flow-through radioactivity detector. The third involves quantitation of various radiolabeled compounds (proteins, steroids, and nucleotides) by splitting the effluent from the HPLC with an electronic steam splitter, thus diverting a present portion to the fraction collector for further chemical characterization and the remainder to the radioactivity flow detector for direct quantitation. A direct comparison of the chromatograms and the radioactivity counting efficiencies of these three techniques is presented

Chitosan Microspheres as Radiolabeled Delivery Devices

International Nuclear Information System (INIS)

Permtermsin, Chalermsin; Ngamprayad, Tippanan; Phumkhem, Sudkanung; Srinuttrakul, Wannee; Kewsuwan, Prartana

2007-08-01

Full text: This study optimized conditions for preparing, characterizing, radiolabeled of chitosan microspheres and the biodistribution of 99mTc-Chitosan microspheres after intravenous administration. Particle size distribution of the microspheres was determined by light scattering. Zeta potential was studied by dynamic light scattering and electrophoresis technique. Biodistribution studies were performed by radiolabeling using 99mTc. The results shown that geometric mean diameter of the microspheres was found to be 77.26?1.96 ?m. Microsphere surface charge of chitosan microspheres was positive charge and zeta potential was 25.80 ? 0.46 mV. The labeling efficiency for this condition was more than 95% and under this condition was stable for at least 6 h. Radioactivity

In vitro characterization of 177Lu-radiolabelled chimeric anti-CD20 monoclonal antibody and a preliminary dosimetry study

International Nuclear Information System (INIS)

Forrer, Flavio; Mueller-Brand, Jan; Chen, Jianhua; Fani, Melpomeni; Powell, Pia; Maecke, Helmut R.; Lohri, Andreas; Moldenhauer, Gerhard

2009-01-01

131 I- and 90 Y-labelled anti-CD20 antibodies have been shown to be effective in the treatment of low-grade, B-cell non-Hodgkin's lymphoma (NHL). However, the most appropriate radionuclide in terms of high efficiency and low toxicity has not yet been established. In this study we evaluated an immunoconjugate formed by the anti-CD20 antibody rituximab and the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). DOTA-rituximab was prepared as a kit formulation and can be labelled in a short time ( 177 Lu or 90 Y. Immunoconjugates with different numbers of DOTA molecules per rituximab were prepared using p-SCN-Bz-DOTA. In vitro immunoreactivity and stability were tested and preliminary dosimetric results were acquired in two patients. The immunological binding properties of DOTA-rituximab to the CD20 antigen were found to be retained after conjugation with up to four chelators. The labelled product was stable against a 10 5 times excess of diethylenetriaminepentaacetic acid (DTPA, 37 C, 7 days). Two patients with relapsed NHL were treated with 740 MBq/m 2 body surface 177 Lu-DOTA-rituximab. Scintigraphic images showed specific uptake at tumour sites and acceptable dosimetric results. The mean whole-body dose was found to be 314 mGy. The administration of 177 Lu-DOTA-rituximab was tolerated well. Our results show that DOTA-rituximab (4:1) can be labelled with 177 Lu with sufficient stability while the immunoconjugate retains its immunoreactivity. 177 Lu-DOTA-rituximab is an interesting, well-tolerated radiolabelled antibody with clinical activity in a low dose range, and provides an approach to the efficient treatment with few side effects for patients with relapsed NHL. (orig.)

Targetted localisation and imaging of a murine lymphoma using 131I-labelled monoclonal antibody

International Nuclear Information System (INIS)

Subbiah, Krishnan; Rayala, Suresh Kumar; Ananthanarayanan, Meenakshi; Thangarajan, Rajkumar

2001-01-01

In vivo tumor targetting with radiolabelled monoclonal antibodies is a promising approach for the diagnosis and therapy of tumors. A specific monoclonal antibody (mAb), DLAB was generated to the Dalton's lymphoma associated antigen (DLAA) from Haemophilus paragallinarum -induced spontaneous fusion. In order to study the tumor localisation and biodistribution properties of the monoclonal antibody, scintigraphic studies were performed using the radiolabelled DLAB. 131I -labelled DLAB was administered intravenously into Swiss mice bearing Dalton's lymphoma and external scintiscanning was performed at different time intervals. Clear tumor images were obtained which revealed selective and specific uptake of radiolabel and the results were compared with biodistribution data. The radioiodinated monoclonal antibody showed fast tumor uptake which increased significantly to 14.6% injected dose (ID)/g at 12 hr post-injection. Enhanced blood clearance of radioactivity resulted in higher tumor/blood ratio of 5.96 at 48 hr. 131I -labelled DLAB resulted in selective and enhanced uptake of the radioactivity by the tumor compared to the non-specific antibody and the results suggest the potential use of spontaneous fusion for producing specific monoclonal antibodies for tumor detection and therapy. (author)

Quantitative relationship between antibody affinity and antibody avidity

International Nuclear Information System (INIS)

Griswold, W.R.

1987-01-01

The relationship between antibody avidity, measured by the dissociation of the antigen-antibody bond in antigen excess, and antibody affinity was studied. Complexes of radiolabelled antigen and antibody of known affinity were prepared in vitro and allowed to stand for seven days to reach equilibrium. Then nonlabelled antigen in one hundred fold excess was added to dissociate the complexes. After an appropriate incubation the fraction of antigen bound to antibody was measured by the ammonium sulfate precipitation method. The dissociation index was the fraction bound in the experimental sample divided by the fraction bound in the control. The correlation coefficient between the dissociation index and the antibody binding constant was 0.92 for early dissociation and 0.98 for late dissociation. The regression equation relating the binding constant to the dissociation index was K = 6.4(DI) + 6.25, where DI is the late dissociation index and K is the logarithm to the base 10 of the binding constant. There is a high correlation between avidity and affinity of antibody. Antibody affinity can be estimated from avidity data. The stability of antigen-antibody complexes can be predicted from antibody affinity

Predicting the biodistribution of radiolabeled cMORF effector in MORF-pretargeted mice

International Nuclear Information System (INIS)

Liu, Guozheng; Dou, Shuping; He, Jiang; Liu, Xinrong; Rusckowski, Mary; Hnatowich, Donald J.

2007-01-01

Pretargeting with phosphorodiamidate morpholino oligomers (MORFs) involves administration of a MORF-conjugated anti-tumor antibody such as MN14 as a pretargeting agent before that of the radiolabeled complementary MORF (cMORF) as the effector. The dosages of the pretargeting agent and effector, the pretargeting interval, and the detection time are the four pretargeting variables. The goal of this study was to develop a semiempirical description capable of predicting the biodistribution of the radiolabeled effector in pretargeted mice and then to compare predictions with experimental results from pretargeting studies in tumored animals in which the pretargeting interval and the detection time were both fixed but the dosages of both the effector and the pretargeting agent were separately varied. Pretargeting studies in LS174T tumored mice were performed using the anti-CEA antibody MN14 conjugated with MORF and the cMORF radiolabeled with 99m Tc. A description was developed based on our previous observations in the same mouse model of the blood and tumor levels of MORF-MN14, accessibility of MORF-MN14 to labeled cMORF, the tumor accumulation of labeled cMORF relative to MORF-MN14 levels therein, and the kidney accumulation of labeled cMORF. The predicted values were then compared with the experimental values. The predicted biodistribution of the radiolabeled effector and the experimental data were in gratifying agreement in normal organs, suggesting that the description of the pretargeting process was reliable. The tumor accumulations occasionally fell outside two standard deviations of that predicted, but after tumor size correction, good agreement between predicted and experimental values was observed here as well. A semiempirical description of the biodistribution of labeled cMORF was capable of predicting the biodistribution of the radiolabeled effector in the pretargeted tumored mouse model, demonstrating that the underlying pretargeting concepts are correct. We

Reactivity comparison of biological material after radiolabeling with avidin-biotin system

International Nuclear Information System (INIS)

Fan Wo; Qian Jianhua; Zhu Benxing

2003-01-01

To find a method for determining the immunoreactivity of monoclonal antibodies after radiolabeling avidin is unlabeled and labeled with Rodamine, 131 I and 188 Re, respectively. The affinities and half-desorbed amounts of biotin and four kinds of avidin are determined by the biotin columns plus non-labeled avidin (cold avidin). The affinities of biotin and avidin unlabeled and labeled with Rodamine, 188 Re and 131 I are decreased in turn. Their half-desorbed amounts from biotin are 21.9, 19.5, 25.7 and 47.9 μg of cold avidin. Two kinds of radiolabeled avidin have lower affinity with biotin than that of avidin unlabeled and labeled with Rodamine. There is a possibility to evaluate the reactivity of biological materials with different labeling methods by avidin-biotin system

Doses to the hand during the administration of radiolabeled antibodies containing Y-90, Tc-99m, I-131, and Lu-177

Energy Technology Data Exchange (ETDEWEB)

Barber, D.E. [Minnesota Univ., Minneapolis, MN (United States). School of Public Health; Carsten, A.L.; Kaurin, D.G.L.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States)

1997-02-01

Exposure of the hands of medical personnel administering radiolabeled antibodies (RABs) was evaluated on the basis of (a) observing and photo-documenting administration techniques, and (b) experimental data on doses to thermoluminescent dosimeters (TLDs) on fingers of phantom hands holding syringes, and on syringes, with radionuclides in the syringes in each case. Actual exposure data for I-131 and Lu-177 were obtained in field studies. Variations in handling and administration techniques were identified. Dose rates measured using TLDs on the surface of loaded syringes were adjusted for differences in electronic stopping power, absorption coefficients, and attenuation between dosimeters and tissue to estimate dose-to-skin averaged over 1 cm{sup 2} at 7 mg cm{sup {minus}2} depth for Y-90, Tc-99m, I-131, and Lu-177. Dose rate coefficients to the skin, if in contact with the syringe wall, were 89, 1.9, 3.8, and 0.41 {micro}Sv s{sup {minus}1} per 37 MBq (1 mCi) for Y-90, Tc-99m, I-131, and Lu-177, respectively. For dose reduction, when using Y-90 the importance was clearly indicated of (a) avoiding direct contact with syringes containing RABs, if practical, and (b) using a beta-particle shield on the syringe. In using a syringe for injection, doses can best be approximated for the geometry studied by (a) wearing a finger dosimeter on the middle finger, toward the outside of the hand, on the hand operating the plunger, and (b) wearing finger dosimeters on the inner (palm) side of the finger on the hand that supports the syringe for energetic beta-particle emitters, such as Y-90 and Re-188.

Doses to the hand during the administration of radiolabeled antibodies containing Y-90, Tc-99m, I-131, and Lu-177

International Nuclear Information System (INIS)

Barber, D.E.

1997-02-01

Exposure of the hands of medical personnel administering radiolabeled antibodies (RABs) was evaluated on the basis of (a) observing and photo-documenting administration techniques, and (b) experimental data on doses to thermoluminescent dosimeters (TLDs) on fingers of phantom hands holding syringes, and on syringes, with radionuclides in the syringes in each case. Actual exposure data for I-131 and Lu-177 were obtained in field studies. Variations in handling and administration techniques were identified. Dose rates measured using TLDs on the surface of loaded syringes were adjusted for differences in electronic stopping power, absorption coefficients, and attenuation between dosimeters and tissue to estimate dose-to-skin averaged over 1 cm 2 at 7 mg cm -2 depth for Y-90, Tc-99m, I-131, and Lu-177. Dose rate coefficients to the skin, if in contact with the syringe wall, were 89, 1.9, 3.8, and 0.41 microSv s -1 per 37 MBq (1 mCi) for Y-90, Tc-99m, I-131, and Lu-177, respectively. For dose reduction, when using Y-90 the importance was clearly indicated of (a) avoiding direct contact with syringes containing RABs, if practical, and (b) using a beta-particle shield on the syringe. In using a syringe for injection, doses can best be approximated for the geometry studied by (a) wearing a finger dosimeter on the middle finger, toward the outside of the hand, on the hand operating the plunger, and (b) wearing finger dosimeters on the inner (palm) side of the finger on the hand that supports the syringe for energetic beta-particle emitters, such as Y-90 and Re-188

Radiolabeled bivalent haptens for tumor immunodetection and radioimmunotherapy

Energy Technology Data Exchange (ETDEWEB)

Gruaz-Guyon, A.; Janevik-Ivanovska, E.; Raguin, O. [Hopital Saint-Antoine, Faculte' de Medecine, Paris (France); De Labriolle-Vaylet, C. [Hopital Saint-Antoine, Faculte' de Medecine, Paris (France); Hopital Saint-Antoine, Service de Medecine Nucleaire, Paris (France); Barbet, J. [Universite' de la Mediterranee, Faculte' de Medecine, Marseille (France)

2001-06-01

The pre targeting technique referred to as the Affinity Enhancement System (AES) uses bispecific antibodies and radiolabeled bivalent haptens that bind cooperatively to target cells in vivo. Experimental and clinical data demonstrate that DTPA bivalent haptens can deliver large radiation doses to tumor cells with high tumor to normal tissue contrast ratios and long activity residence time in tumors. Preliminary clinical results of radioimmunotherapy of medullary thyroid carcinomas and lung cancers look promising. Very encouraging results in biodistribution and radioimmunotherapy experiments in animals have been obtained with new haptens bearing two histamine-hemisuccinate suitable for {sup 131}I, {sup 99m}Tc and {sup 188}Re labeling. Targeting isotopes to double antigen positive tumor cells provides a binding enhancement that increases specificity for tumor cells as compared to single antigen targeting on normal cells. This approach may be beneficial for targeting isotopes to B type acute lymphoblastic leukemia and Burkitt lymphoma, as well as others tumors co-expressing two markers of low specificity, and might increase tumor irradiation with minimal irradiation of normal cells.

Radiolabeled bivalent haptens for tumor immunodetection and radioimmunotherapy

International Nuclear Information System (INIS)

Gruaz-Guyon, A.; Janevik-Ivanovska, E.; Raguin, O.; De Labriolle-Vaylet, C.; Barbet, J.

2001-01-01

The pre targeting technique referred to as the Affinity Enhancement System (AES) uses bispecific antibodies and radiolabeled bivalent haptens that bind cooperatively to target cells in vivo. Experimental and clinical data demonstrate that DTPA bivalent haptens can deliver large radiation doses to tumor cells with high tumor to normal tissue contrast ratios and long activity residence time in tumors. Preliminary clinical results of radioimmunotherapy of medullary thyroid carcinomas and lung cancers look promising. Very encouraging results in biodistribution and radioimmunotherapy experiments in animals have been obtained with new haptens bearing two histamine-hemisuccinate suitable for 131 I, 99m Tc and 188 Re labeling. Targeting isotopes to double antigen positive tumor cells provides a binding enhancement that increases specificity for tumor cells as compared to single antigen targeting on normal cells. This approach may be beneficial for targeting isotopes to B type acute lymphoblastic leukemia and Burkitt lymphoma, as well as others tumors co-expressing two markers of low specificity, and might increase tumor irradiation with minimal irradiation of normal cells

Optimization of AFP-radioimmunoassay using Antibody Capture Technique

International Nuclear Information System (INIS)

Moustafa, K.A.

2003-01-01

Alpha-fetoprotein (AFP) is a substance produced by the unborn baby. When the neural tube is not properly formed large amounts of AFP pass into the amniotic fluid and reach the mother's blood. By measuring AFP in the mother's blood and amniotic fluid, it is possible to tell whether or not there is a chance that the unborn baby has a neural tube defect. AFP also used as a tumor marker for hepatocellular carcinoma. There are many different techniques for measuring AFP in blood, but the most accurate one is the immunoassay technique. The immunoassays can be classified on the basis of methodology into three classes; (1) the antibody capture assays, (2) the antigen capture assay, (3)the two-antibody sandwich assays. In this present study, the antibody capture assay in which the antigen is attached to a solid support, and labeled antibody is allowed to bind, will be optimized

Development of a stable radioiodinating reagent to label monoclonal antibodies for radiotherapy of cancer

International Nuclear Information System (INIS)

Wilbur, D.S.; Hadley, S.W.; Hylarides, M.D.; Abrams, P.G.; Beaumier, P.A.; Morgan, A.C.; Reno, J.M.; Fritzberg, A.R.

1989-01-01

A method of radioiodinating monoclonal antibodies such that the labeled antibodies do not undergo in vivo deiodination has been studied. The method utilizes conjugation of succinimidyl para-iodobenzoate to the antibody. The iodobenzoate was radiolabeled by using an organometallic intermediate to facilitate the reaction. Thus, succinimidyl para-tri-n-butylstannylbenzoate was radiolabeled in 60-90% radiochemical yield and subsequently conjugated to the antibody in 80-90% yield. Animal biodistribution studies were carried out with two separate anti-melanoma antibodies (9.2.27 and NR-M1-05) labeled by this method, and examined in nude mice bearing human melanoma tumor xenografts. Very large differences in the localization of radioactivity were observed in the thyroids and stomachs of mice when the iodobenzoyl-labeled antibodies were compared with the same antibodies labeled using the chloramine-T method of radioiodination. Few other significant differences in the tissue distribution of the radioiodinated antibodies were seen

Perfusion of tumor-bearing kidneys as a model for scintigraphic screening of monoclonal antibodies

International Nuclear Information System (INIS)

van Dijk, J.; Oosterwijk, E.; van Kroonenburgh, M.J.; Jonas, U.; Fleuren, G.J.; Pauwels, E.K.; Warnaar, S.O.

1988-01-01

Tumor-bearing human kidneys were used in an ex vivo perfusion model to screen monoclonal antibodies, recognizing renal cell carcinoma-associated antigens for diagnostic potential in vivo. Perfusion of tumor-bearing kidneys with /sup 99m/Tc-labeled G250 and RC38 antibody resulted in visualization of the tumor, whereas perfusion with two other monoclonal antibodies, RC2 and RC4, did not lead to tumor visualization. Uptake of radiolabel in normal kidney tissue was low for G250 and RC38 antibody. Tumor-to-kidney tissue ratios after perfusion with G250 and RC38 antibody were 2.7 and 2.2, respectively. After rinsing for 3 hr with unlabeled perfusion fluid the tumor-to-kidney tissue ratios increased to 8.6 for G250 antibody and to 2.7 for RC38 antibody. We conclude that perfusion of tumor-bearing human kidneys with radiolabeled monoclonal antibodies is a relatively simple way to evaluate renal cell carcinoma associated monoclonal antibodies as diagnostic agents in vivo

Detection of human cancer in an animal model using radio-labelled tumour-associated monoclonal antibodies

International Nuclear Information System (INIS)

Epenetos, A.A.; Arklie, J.; Knowles, R.W.; Bodmer, W.F.

1982-01-01

Monoclonal antibodies to epithelial-cell antigenic determinants, labelled with 123 I and 125 I, were administered parenterally to immunodeficient mice bearing human tumours derived from a human cancer cell line. Anterior, posterior and lateral radioscans of the body were taken with a gamma scintillation camera at various times from immediately to 65 days after injection. Visual displays of the images were processed by standard computer techniques. The model used a human colon-cancer cell line, HT29, and the monoclonal antibody, AUAl, which is specific to an epithelial proliferating antigen. Tumour detection was achieved in all the mice. The smallest tumour detectable appeared to be about 1 mm in diameter. The degree of antibody uptake in a tumour depended on its size and the blood supply of its surrounding tissues. (author)

[Investigations into the use of radiolabeled monoclonal antibodies for selective cell labeling in whole blood]: Progress report, March 1985-May 1988

International Nuclear Information System (INIS)

Thakur, M.L.

1987-01-01

Seventeen monoclonal antibodies (MAbs), 7 specific for human platelets and 10 specific for human polumorphonuclear leukocytes (PMNs) have been evaluated. One MAb has been identified as the antibody most suitable for canine platelets and another has been evaluted as the best among the group, for human neutrophil studies. Indium-111, Tc-99m, and I-125 have been used as the tracers. Six bifunctional chelating agents (BFCAs) were evaluated in order to determine the most efficient agent for maximal cell labeling efficiency. Among these, the DTPA has given us the best results. (4) To botain maximum In-111 chelation and minimum loss of the MAb affinity, the optimal BFCA to MAb ratios for both IgG and IgM type of MAbs were determined. Four different substances, stannous chloride, ascorbic acid, sodium dithionite and sodium borohydride, were evaluated as reducing agents for Tc-99m reduction and its optimal binding to MAbs. Dithionite at the concentration of 200 ug/ml DTPA-MAb solution provides greater than 50% Tc-99m labeling efficiency and maintains its immunospecificity equal to that of In-111-DTPA-MAb. The ability of radiolabeled MAb to interact with blood cells selectively in whole blood and with isolated blood cells was assessed and compared

Monoclonal anti-melanoma antibodies and their possible clinical use

International Nuclear Information System (INIS)

Hellstroem, K.E.; Hellstroem, Ingegerd; Washington Univ., Seattle; Washington Univ., Seattle

1985-01-01

Cell surface antigens of human melanoma, as defined by monoclonal antibodies, are discussed and in particular the three antigens p97, a GD3 ganglioside and a proteoglycan. The potential diagnostic uses of antibodies to melanoma antigens are reviewed including in vitro diagnosis by immuno-histology, in vitro diagnosis by serum assays and in vivo diagnosis by tumour imaging using radioactively labelled antibodies. The potential therapeutic uses of monoclonal antibodies to melanoma antigens are also reviewed including targets for antibody therapy, the use of antibodies alone, radiolabelled antibodies, antibody-toxin conjugates, antibody-drug conjugates, anti-idiotypic antibodies and vaccines. (UK)

Use of radiolabeled antibodies as diagnostic imaging agents

International Nuclear Information System (INIS)

Wang, T.S.T.; Seldin, D.; Fawwaz, R.A.; Srivastava, S.; Olvwole, S.

1989-01-01

Recent advances in hybridoma technology have led to the development of monoclonal antibodies to a variety of antigens. The high degree of specificity of such reagents coupled with refinements in instrumentation and production of new radionuclides has rekindled interest in the application of radioimmunoscintigraphy in the diagnosis of various diseases. Although much of the work with monoclonal antibodies has been devoted to the diagnosis and treatment of tumors, increasing use is being made of these agents for the study of nontumor related disorders. This chapter focuses on the application of radioimmunoscintigraphy in the diagnosis of malignancies with a discussion on the other uses, notably those related to the vascular system

In vitro characterization of {sup 177}Lu-radiolabelled chimeric anti-CD20 monoclonal antibody and a preliminary dosimetry study

Energy Technology Data Exchange (ETDEWEB)

Forrer, Flavio; Mueller-Brand, Jan [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Chen, Jianhua; Fani, Melpomeni; Powell, Pia; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Basel (Switzerland); Lohri, Andreas [Basel University Medical Clinic, Liestal (Switzerland); Moldenhauer, Gerhard [German Cancer Research Center, Division of Molecular Immunology, Heidelberg (Germany)

2009-09-15

{sup 131}I- and {sup 90}Y-labelled anti-CD20 antibodies have been shown to be effective in the treatment of low-grade, B-cell non-Hodgkin's lymphoma (NHL). However, the most appropriate radionuclide in terms of high efficiency and low toxicity has not yet been established. In this study we evaluated an immunoconjugate formed by the anti-CD20 antibody rituximab and the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). DOTA-rituximab was prepared as a kit formulation and can be labelled in a short time (<20 min) with either {sup 177}Lu or {sup 90}Y. Immunoconjugates with different numbers of DOTA molecules per rituximab were prepared using p-SCN-Bz-DOTA. In vitro immunoreactivity and stability were tested and preliminary dosimetric results were acquired in two patients. The immunological binding properties of DOTA-rituximab to the CD20 antigen were found to be retained after conjugation with up to four chelators. The labelled product was stable against a 10{sup 5} times excess of diethylenetriaminepentaacetic acid (DTPA, 37 C, 7 days). Two patients with relapsed NHL were treated with 740 MBq/m{sup 2} body surface {sup 177}Lu-DOTA-rituximab. Scintigraphic images showed specific uptake at tumour sites and acceptable dosimetric results. The mean whole-body dose was found to be 314 mGy. The administration of {sup 177}Lu-DOTA-rituximab was tolerated well. Our results show that DOTA-rituximab (4:1) can be labelled with {sup 177}Lu with sufficient stability while the immunoconjugate retains its immunoreactivity. {sup 177}Lu-DOTA-rituximab is an interesting, well-tolerated radiolabelled antibody with clinical activity in a low dose range, and provides an approach to the efficient treatment with few side effects for patients with relapsed NHL. (orig.)

Iodogen-mediated radiolabeling of Bevacizumab with I-123 for clinical applications

International Nuclear Information System (INIS)

Lemps, R. de; Desruet, M.; Bacot, S.; Ahmadi, M.; Ghezzi, C.; Desruet, M.; Fagret, D.; Berger, F.

2014-01-01

Bevacizumab is a monoclonal antibody, directed against vascular endothelial growth factor (VEGF), and is currently used in various types of cancers (breast, lung, colorectal). In order to administer to humans glioblastomas, we developed its iodine 123 radiolabeling for in vitro and in vivo studies subsequent. The aim of the study is to choose the best radioiodination conditions based on feasibility in a hospital radiopharmacy: Quick one step method under mild condition, reproducible, using materials for pharmaceutical use and in a closed-system. Method Bevacizumab was radiolabeled with "1"2"3I using Iodogen, the most widely used oxidants in direct labelling techniques for tyrosyl residues-containing compounds. We have been explored two crucial parameters for clinical transfer: the amount of oxidant required (50μg and 100μg) and the choice of the purification column (size exclusion column or anion exchange resin), respectively. Quality control was performed before and after purification of each condition in order to evaluate the radiochemical purity (RCP) and purification efficiency. The stability of the radiolabeled molecule is evaluated over time and also when the solution is diluted with unlabeled bevacizumab. Moreover, the in vitro stability of "1"2"3I-bevacizumab was determined in presence of human blood at 15, 30, 60 and 120 min. Labeling yield before purification was 96.5% for the first condition (50μg Iodogen) and 95.5% for the second one (100μg Iodogen). The radiochemical purity was 99.5% after purification on a size exclusion column and 99% after purification on anion exchange resin. The purification yield with size exclusion column is 75%, compared with 81% of the anionic exchange resin. The stability in the labeling medium of "1"2"3I-bevacizumab at 3, 6, 24 and 30 h after labeling showed a RCP at 100%, 93%, 99.8% and 99.8% for condition 1 so that it was found to be 99.2%, 100%, 99.3%, 99.5% for condition 2, respectively. In vitro incubation with

Innovations that influence the pharmacology of monoclonal antibody guided tumor targeting

International Nuclear Information System (INIS)

Schlom, J.; Hand, P.H.; Greiner, J.W.; Colcher, D.; Shrivastav, S.; Carrasquillo, J.A.; Reynolds, J.C.; Larson, S.M.; Raubitschek, A.

1990-01-01

Tumor targeting by monoclonal antibodies (MAbs) can be enhanced by (a) increasing the percentage of injected dose taken up by the tumor and/or (b) increasing the tumor:nontumor ratios. Several groups have demonstrated that one can increase tumor to nontumor ratios by the use of antibody fragments or the administration of second antibodies. Several other modalities are also possible: (a) the use of recombinant interferons to up-regulate the expression of specific tumor associated antigens such as carcinoembryonic antigen or TAG-72 on the surface of carcinoma cells and thus increase MAb tumor binding has proved successful in both in vitro and in vivo studies; (b) the intracavitary administration of MAbs. Recent studies have demonstrated that when radiolabeled B72.3 is administered i.p. to patients with carcinoma of the peritoneal cavity, it localizes tumor masses with greater efficiency than does concurrent i.v. administered antibody. Studies involving the comparative pharmacology of intracavitary administration of radiolabeled MAb in patients and several animal models will be discussed; (c) it has been reported that prior exposure of hepatoma to external beam radiation will increase radiolabeled MAb tumor targeting. We and others have not been able to duplicate this phenomenon with a human colon cancer xenograft model and radiolabeled MAbs to two different colon carcinoma associated antigens. The possible reasons for these differences will be discussed; (d) the cloning and expression of recombinant MAbs with human constant regions and subsequent size modification constructs will also undoubtedly alter the pharmacology of MAb tumor binding in both diagnostic and therapeutic applications. 66 references

Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions

Energy Technology Data Exchange (ETDEWEB)

Deutscher, Susan

2014-09-30

The objective of this research is to develop phage display-selected peptides into radio- and fluoresecently- labeled scaffolds for the multimodal imaging of carbohydrate-lectin interactions. While numerous protein and receptor systems are being explored for the development of targeted imaging agents, the targeting and analysis of carbohydrate-lectin complexes in vivo remains relatively unexplored. Antibodies, nanoparticles, and peptides are being developed that target carbohydrate-lectin complexes in living systems. However, antibodies and nanoparticles often suffer from slow clearance and toxicity problems. Peptides are attractive alternative vehicles for the specific delivery of radionuclides or fluorophores to sites of interest in vivo, although, because of their size, uptake and retention may be less than antibodies. We have selected high affinity peptides that bind a specific carbohydrate-lectin complex involved in cell-cell adhesion and cross-linking using bacteriophage (phage) display technologies (1,2). These peptides have allowed us to probe the role of these antigens in cell adhesion. Fluorescent versions of the peptides have been developed for optical imaging and radiolabeled versions have been used in single photon emission computed tomography (SPECT) and positron emission tomography (PET) in vivo imaging (3-6). A benefit in employing the radiolabeled peptides in SPECT and PET is that these imaging modalities are widely used in living systems and offer deep tissue sensitivity. Radiolabeled peptides, however, often exhibit poor stability and high kidney uptake in vivo. Conversely, optical imaging is sensitive and offers good spatial resolution, but is not useful for deep tissue penetration and is semi-quantitative. Thus, multimodality imaging that relies on the strengths of both radio- and optical- imaging is a current focus for development of new in vivo imaging agents. We propose a novel means to improve the efficacy of radiolabeled and fluorescently

Bystander responses in three-dimensional cultures containing radiolabelled and unlabelled human cells

International Nuclear Information System (INIS)

Pinto, M.; Azzam, E. I.; Howell, R. W.

2006-01-01

Research on the radiation-induced bystander effect has been carried out mainly in 2-D tissue culture systems. This study uses a 3-D model, wherein apparently normal human diploid fibroblasts (AG1522) are grown in a carbon scaffold, to investigate the induction of a G 1 checkpoint in bystander cells present alongside radiolabelled cells. Cultures were simultaneously pulse-labelled with 3 H-deoxycytidine ( 3 HdC) to selectively irradiate a minor fraction of cells, and bromodeoxyuridine (BrdU) to identify the radiolabelled cells. After thorough washing of cultures, iododeoxyuridine (IdU) was administered to detect proliferating bystander cells. The cultures were harvested at various times thereafter, and cells were reacted with two monoclonal antibodies specific to IdU/BrdU or BrdU, respectively, stained with propidium iodide, and subjected to multi-parameter flow cytometry. Cell-cycle progression was followed in radiolabelled cells (BrdU + ) that were chronically irradiated by low energy beta particles emitted by DNA-incorporated 3 H, and in unlabelled bystander cells (BrdU - ) by a flow cytometry based cumulative labelling index assay. As expected, radiolabelled cells were delayed, in a dose-dependent manner, in G 2 and subsequently G 1 . No delay occurred in progression of bystander cells through G 1 , when the labelled cells were irradiated at dose rates up to 0.32 Gy h -1 . (authors)

Radiolabeled antifibrin antibody in the detection of venous thrombosis: Preliminary results

International Nuclear Information System (INIS)

Alavi, A.; Palevsky, H.I.; Gupta, N.; Meranze, S.; Kelley, M.A.; Jatlow, A.D.; Schaible, T.F.; Brown, J.; Berger, H.J.

1990-01-01

The recent development of monoclonal antibodies against components of coagulated blood may provide new approaches to the diagnosis of venous thrombosis. Scanning with an indium-111-labeled Fab fragment of a murine monoclonal antifibrin antibody (59D8) and ascending contrast venography were performed in 33 patients. Images of the calves, popliteal fossae, thighs, and pelvis were obtained immediately, 4-6 hours, and 24 hours after injection of 2 mCi (74 MBq) of the antibody. All images were read in a blinded manner. Findings in both studies were positive in 28 patients and negative in three. In 19 patients not undergoing heparin therapy, 19 specific anatomic sites were positive on venograms and 29 were positive on antibody images (19 sites matched). In 14 patients undergoing heparin therapy, 34 sites were positive on venograms and 27 were positive on antibody images (22 sites matched). In most patients, positive results were noted within 1 hour of antibody injection. No adverse effects were noted with the antibody preparation. Preliminary data suggest that antifibrin antibody imaging is sensitive in detecting clots, is safe to use, and may have a role in diagnosing and managing venous thrombosis

Radiolabelled monoclonal antibodies against alpha-fetoprotein for in vivo localization of human hepatocellular carcinoma by immunotomoscintigraphy

International Nuclear Information System (INIS)

Bergmann, J.F.; Lumbroso, J.D.; Manil, L.; Saccavini, J.C.; Rougier, P.; Assicot, M.; Mathieu, A.; Bellet, D.; Bohuon, C.

1987-01-01

Two high affinity monoclonal antibodies, designated AF01 and AF04, directed against distinct epitopes of human alpha-fetoprotein (AFP) and the Fab fragments of one of them, were labelled with 131 I and injected into 18 patients with AFP producing hepatocellular carcinoma (HCC) in order to carry out imaging studies by tomoscintigraphy. Twelve patients were injected with whole antibody, only three of seven patients injected with AF01 and two of five patients injected with AF04 had a positive scan. In contrast, five out of six patients injected with labelled Fab fragments of AF04 had positive imaging. These results confirm that tumour imaging of HCC using 131 I labelled monoclonal antibody against AFP is feasible. Moreover, utilization of tomoscintigraphy in place of linear scintigraphy and Fab fragments instead of whole immunoglobulin may improve the sensitivity of radioimmunolocalization. This technique provides useful information on the in vivo distribution of monoclonal antibodies directed against AFP and on the practicability of the eventual therapeutic use of anti-AFP antibodies in HCC. (orig.)

High performance liquid chromatography in studies of radiolabeled antibodies

International Nuclear Information System (INIS)

Hnatowich, D.J.

1986-01-01

High performance liquid chromatography (HPLC) as applied to the separation of antibodies displays the same advantages as in its other applications, namely good resolution accompanied by fast analysis. It is therefore not surprising that many HPLC columns designed for use with antibodies and other proteins are now available commercially. The properties of proteins which provide the separation are size, hydrophobicity, charge and affinity. The features of each are discussed. (author)

Radiolabelled sucralfate compositions

International Nuclear Information System (INIS)

Vasquez, T.E.; Bridges, R.L.; Braunstein, P.; Jansholt, A.

1984-01-01

A novel radiopharmaceutical composition comprising an aqueous solution or suspension containing a radiolabelled sucralfate or sucralfate derivative or precursor is claimed. The composition is effective for in vivo scintigraphic imaging of the gastrointestinal muscosal areas in humans. The sucralfate is combined with a radiolabelled albumin or other protein or protein derivative under acidic conditions

Potential of 57Ni/57Co generator system for radiolabelling proteins for imaging

International Nuclear Information System (INIS)

Du, T.; Smith, S.V.; Baker, T.

1998-01-01

Full text: There is increasing interest in the use of inert metal complexes for radiolabelling proteins. The present study involves an investigation into the use to the parent/daughter system 57 Ni/ 57 Co for PET and SPECT imaging. In order to assess the potential of the system for such applications it is important to examine whether the ligand chosen complexes with both 57 Ni and 57 Co. A selection of ligands with varying number of donor groups and open-chain and macrocyclic ligands were chosen; ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), 1,4,8,11 - tetraazocyclotetradecane-1 4,8,11-tetraacetic acid (TETA) and diaminohydroxyaryl - diethylenetriaminepentaacetic acid, (DAHA-EDTA). Complexation behaviour over a range of pH and temperatures was investigated. Results show that the ligands have strong complexation for 57 Ni however once 57 Ni decayed to 57 Co evidence ol chemical instability was noted. The DAHA-EDTA ligand (developed in house) was observed to be the most stable under conditions studied. lt was selected for use in radiolabelling B72.3 antibody and preliminary radiolabelling conditions were established

Aligning physics and physiology: Engineering antibodies for radionuclide delivery.

Science.gov (United States)

Tsai, Wen-Ting K; Wu, Anna M

2018-03-14

The exquisite specificity of antibodies and antibody fragments renders them excellent agents for targeted delivery of radionuclides. Radiolabeled antibodies and fragments have been successfully used for molecular imaging and radioimmunotherapy (RIT) of cell surface targets in oncology and immunology. Protein engineering has been used for antibody humanization essential for clinical applications, as well as optimization of important characteristics including pharmacokinetics, biodistribution, and clearance. Although intact antibodies have high potential as imaging and therapeutic agents, challenges include long circulation time in blood, which leads to later imaging time points post-injection and higher blood absorbed dose that may be disadvantageous for RIT. Using engineered fragments may address these challenges, as size reduction and removal of Fc function decreases serum half-life. Radiolabeled fragments and pretargeting strategies can result in high contrast images within hours to days, and a reduction of RIT toxicity in normal tissues. Additionally, fragments can be engineered to direct hepatic or renal clearance, which may be chosen based on the application and disease setting. This review discusses aligning the physical properties of radionuclides (positron, gamma, beta, alpha, and Auger emitters) with antibodies and fragments and highlights recent advances of engineered antibodies and fragments in preclinical and clinical development for imaging and therapy. Copyright © 2018 John Wiley & Sons, Ltd.

Initial clinical evaluation of radiolabeled MX-DTPA humanized BrE-3 antibody in patients with advanced breast cancer.

Science.gov (United States)

Kramer, E L; Liebes, L; Wasserheit, C; Noz, M E; Blank, E W; Zabalegui, A; Melamed, J; Furmanski, P; Peterson, J A; Ceriani, R L

1998-07-01

To evaluate radiometal-labeled humanized BrE-3 (huBrE-3) monoclonal antibody as a radioimmunolocalization and therapeutic agent in breast cancer patients, tumor localization, pharmacokinetics, radiation dosimetry, and immunogenicity of (111)In-labeled combined 1-p-isothiocyanatobenzyl 3-methyl- and 1-p-isothiocyanatobenzyl 4-methyldiethylenetriamine pentaacetic acid (MX-DTPA) huBrE-3 were studied. Seven women with BrE-3 antigen-positive, metastatic breast carcinoma underwent (111)In huBrE-3 infusion (5 mCi; 50 mg), followed by serial gamma camera imaging and plasma sampling. Region of interest analysis of images was used to make radiation absorbed dose estimates for (111)In huBrE-3. Data were extrapolated to 90Y huBrE-3. Human anti-human antibody (HAHA) response was measured in serum samples obtained up to 3 months after infusion. Patients tolerated infusions well. Seventy-six percent of 105 known sites of disease were identified on planar and single-photon emission computed tomography scans. For six of seven patients, a biexponential model fit the plasma time-activity curve best with an average T1/2alpha=10.6+/-8.5 (SD) h and average T1/2beta=114.2+/-39.2 h. Radiation absorbed dose estimates for (111)In huBrE-3 for whole body averaged 0.53+/-.08 rads/mCi. Dose estimates for 90Y huBrE-3 for marrow averaged 8.4+/-11.9 rads/mCi, and for tumors, 70+/-31.5 rads/mCi. Liver radioactivity uptake averaged 19.7+/-8.8% injected dose at 24 h after infusion, translating into an average radiation absorbed dose 21.1+/-12 rads/90Y mCi administered. Only one of seven patients demonstrated a low level of HAHA response. Although the plasma half-lives are longer and marrow dose higher for radiolabeled huBrE-3 compared with the murine construct, the excellent tumor localization, good tumor dosimetry, and low immunogenicity support the use of 90Y-huBrE-3 antibody for radioimmunotherapy of breast cancer.

Radiolabeling and animal experimental studies of anti-breast cancer McAb 6C6 and mouse-human chimeric antibody 6C6CHI

International Nuclear Information System (INIS)

Yang Zhi; Hu Xiaoqian; Li Erqiu

2003-01-01

The aim of this work is to study bio-distribution and tumor absorption of anti breast cancer monoclonal antibody 6C6 and its chimeric antibody 6C6-CHI. The modified Schwartz method was employed to label 6C6 and 6C6CHI with 99 Tc m . The labeled antibody was injected to mouse via tail vein and the blood clearance and whole body clearance were observed. Nude mice bearing breast cancer MCF7 were injected with 99 Tc m -labeled antibody and the bio-distribution was studied and imaged with γ-ray camera. The yield of the two labeled antibodies was more than 90% and their immunoactivities were more than 80%. The whole body eliminated half-time of 99 Tc m -6C6 was 4.1h, and the half-times in blood were T α =0.55h and T β =12.42h respectively. The whole body half-time of 99 Tc m -6C6CHI was 4.28h and the half-times in blood were T α =0.98h and T β =12.42h respectively. The bio-distribution of nude mice bearing breast cancer MCF7 cells was as follows: the ID%/g of tumor and blood was (7.42±0.85) and (5.67±1.44) respectively at 23h after injection of 99 Tc m -6C6. The T/NT (tumor to non tumor) ratios were all more than 1.0 except kidney and the ID%/g of tumor and blood was (4.23±0.64) and (6.97±0.23) respectively at 23 h after injection of 99 Tc m -6C6CHI. The T/NT (tumor to non tumor) ratios were all more than 1.0 except blood and kidney. The γ imaging results showed that the tumor was imaged clearly at 24h after injection of radiolabeled antibodies and the other organs did not concentrate the antibodies except kidney. Anti-breast cancer monoclonal antibody 6C6 can be well located in tumor. Although ID%/g of tumor of the chimeric antibody 6C6CHI was slightly lower than that of 6C6 antibody, and ID%/g of blood was higher than that of 6C6, the tumor imaging of 6C6-CHI was also clear

Advances in infectious foci imaging using 99mTc radiolabelled antibiotics

International Nuclear Information System (INIS)

Seyedeh Fatemeh Mirshojaei

2015-01-01

Conventional methods of infection diagnosis, relying on experimental tests and culture of organisms from infected foci have continued to developing new technologies and automation. Nuclear medicine is a reliable diagnostic technique capable to detect infectious foci in human disease. A wide range of radiolabeled agents have been evaluated for demonstrating their ability to distinguish microbial infectious lesions. New researches continue to be made on the use of radiolabeled antibiotics which as well as being highly specific in the diagnosis of infection would be useful in monitoring of disease treatment. Here, the new approaches of infection scintigraphic imaging by radiolabeled antibiotics are thoroughly discussed in order to assess and compare their diagnostic value as targeting imaging radiopharmaceuticals. (author)

ETAC reagents: A new class of sulfhydryl site-specific radiolabelling probes for antibodies

International Nuclear Information System (INIS)

del Rosario, R.B.; Brocchini, S.J.; Baron, L.A.; Smith, R.H.; Lawton, R.G.; Wahl, R.L.

1990-01-01

A new class of bis-alkylating Michael reagents, equilibrium transfer crosslink reagents, 'ETAC', which combine the techniques of crosslinking with tethering have been synthesized. Following a succession of Michael and retro-Michael additions and elimination of the arylsulfone groups, reduced heavy-heavy and heavy-light disulfide links of an anti-ovarian IgG2a monoclonal antibody, 5G6.4, were site-specifically re-annealed via a 3-carbon bridge having a tether branch containing a designated label

{sup 99m}Tc-rituximab radiolabelled by photo-activation: a new non-Hodgkin's lymphoma imaging agent

Energy Technology Data Exchange (ETDEWEB)

Gmeiner Stopar, T.; Fettich, J.; Hojker, S. [University Medical Centre Ljubljana, Department for Nuclear Medicine, Ljubljana (Slovenia); Mlinaric-Rascan, I. [University of Ljubljana, Faculty of Pharmacy, Ljubljana (Slovenia); Mather, S.J. [St Bartholomew' s Hospital, Cancer Research UK, Department Nuclear Medicine, London (United Kingdom)

2006-01-01

Rituximab was the first chimeric monoclonal antibody to be approved for treatment of indolent B-cell non-Hodgkin's lymphoma (NHL). It is directed against the CD20 antigen, which is expressed by 95% of B-cell NHLs. The aim of this study was to explore the possibility of radiolabelling rituximab with {sup 99m}Tc for use as an imaging agent in NHL for early detection, staging, remission assessment, monitoring for metastatic spread and tumour recurrence, and assessment of CD20 expression prior to (radio)immunotherapy. Rituximab was purified from Mabthera solution (Roche), photo-activated at 302 nm by UV irradiation and radiolabelled with {sup 99m}Tc. The effectiveness of the labelling method was evaluated by determination of the number of free thiol groups per photoreduced antibody, radiochemical purity and in vitro stability of {sup 99m}Tc-rituximab. On average, 4.4 free thiol groups per photoreduced antibody were determined. Radiolabelling yields greater than 95% were routinely observed after storage of the photo-activated antibody at -80 C for 195 days. The direct binding assay showed preserved ability of {sup 99m}Tc-rituximab to bind to CD20, with an average immunoreactive fraction of 93.3%. The internalisation rate was proven to be low, with only 5.3% of bound {sup 99m}Tc-rituximab being internalised over 4 h at 37 C. Our results demonstrate that {sup 99m}Tc-rituximab of high radiochemical purity and with preserved binding affinity for the antigen can be prepared by photoreduction and that the method shows good reproducibility. {sup 99m}Tc-rituximab will be further explored as an imaging agent applicable in NHL for the purposes mentioned above. (orig.)

An improved autoradiographic technique for the detection of antibody-forming cells

International Nuclear Information System (INIS)

Mason, D.W.

1976-01-01

An autoradiographic technique for the detection of antibody-forming cells has been developed for the assay of anti-DNP responses. The lymphoid cell suspension to be assayed was allowed to sediment on to a glass slide coated with DNP-conjugated gelatin to which the secreted antibody bound during subsequent incubation. The bound antibody and its Ig class was revealed by a second incubation using 125 I-anti-immunoglobulin reagents followed by autoradiography. Studies on the sensitivity and specificity of the method are presented and its advantages over other techniques described. The technique should be readily applicable to other haptens

Radiolabeling of anti-CD20 with Re0-188: liquid kit

International Nuclear Information System (INIS)

Dias, Carla Roberta; Osso Junior, Joao Alberto

2007-01-01

Radioimmunotherapy uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. The radionuclide 188 Re is currently produced from the father nuclide 188 W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E βMAX =2.1 MeV, t 1/2 =16.9 h, E γ =155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agents and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of radiolabeling of anti-CD20 with 188 Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-ME and purified over a PD-10 column. The number of resulting free SH was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent, reaction time and 188 Re volume in the liquid kit. Radiochemical purity of 188 Re-anti-CD20 was evaluated. An average of 12 SH groups per mol in the reductions was found. The best labeling efficiency (> 93%) was achieved in the following conditions: 1 mg anti-CD20; 82.8 mg sodium tartrate; 1 mg SnCl 2 ; 0.25 mg gentisic acid, 1 mL 188 Re and reaction time of 1 hour at room temperature. (author)

Radiometallating antibodies and autoantigenic peptides

International Nuclear Information System (INIS)

Mercer-Smith, J.A.; Lewis, D.; Cole, D.A.; Newmyer, S.L.; Schulte, L.D.; Mixon, P.L.; Schreyer, S.A.; Burns, T.P.; Roberts, J.C.; Figard, S.D.; McCormick, D.J.; Lennon, V.A.; Hayashi, M.; Lavallee, D.K.

1991-01-01

We have developed methods to radiolabel large molecules, using porphyrins as bifunctional chelating agents for radiometals. The porphyrins are substituted with an N- benzyl group to activate them for radiometallation under mild reaction conditions. Porphyrins that have one functional group for covalent attachment to other molecules cannot cause crosslinking. We have examined the labeling chemistry for antibodies and have developed methods to label smaller biologically active molecules, such as autoantigenic peptides (fragments of the acetylcholine receptor), which are pertinent to myasthenia gravis research. The methods of covalent attachment of these bifunctional chelating agents to large molecules, the radiometallation chemistry, and biological characterization of the radiolabeled compounds will be discussed

Endobronchial administration of iodine-131 B72.3 monoclonal antibody in patients with lung cancer

International Nuclear Information System (INIS)

Del Vecchio, S.; Mansi, L.; Petrillo, A.; Camera, L.; Salvatore, M.; Sofia, M.; Marra, A.; Carratu, L.

1991-01-01

We tested the feasibility of endobronchial administration of radiolabelled monoclonal antibodies (MoAbs) and the biodistribution of the radiotracer. Ten patients with histological confirmed adenocarcinoma or squamous cell carcinoma were studied. Nine received 470 μCi (103 μg) of 131 I-B72.3, a monoclonal antibody reacting against TAG 72 antigen, while one patient received 502 μCi (291 μg) of 131 I-4C4, an indifferent antibody used for comparison in a negative control study. The radiolabelled antibody was administered through a flexible fiberoptic bronchoscope and placed on the tumour mass under visual monitoring. Scans with a large field-of-view gamma-camera showed retention of 131 I-B72.3 at the tumour site up to 6-9 days in six of eight patients. No other organs were visualized with the exception of faint activity in the gastrointestinal tract, bladder and thyroid. On the contrary, the indifferent antibody 131 I-4C4 was not retained at the tumour site 6 days after MoAbs administration, and more prominent activity was found in the gastrointestinal tract. In one patient the study was not technically adequate because of failure of the delivery system. The vascular compartment contained less than 3% of the administered dose. We conclude that endobronchial administration is a feasible technique and allows stable and specific targetting of bronchial tumours. Furthermore, the low activity found in the plasma and other organs suggests that this approach may be used to deliver therapeutic doses of MoAbs to lung cancers. (orig.)

Technetium-99m pertechnetate - a tracer for radiolabelling antibody for inflammation detection

International Nuclear Information System (INIS)

Shaharuddin Mohd; Wan Hamirul Bahrin Wan Kamal; Shahrin A Hamid; Ang Woan Tze; Rosnani Hashim

1999-01-01

The polyclonal antibody, Human Immunoglobulin G (HlgG) was reduced by using 2-mercaptoethanol with molar ratio of 1000:1 (i.e. mercaptoethanol:antibody). The reduction of the antibody, was carried out for 30 minutes at room temperature. The reduced antibody was purified by using Sephadex G-25 fine column. The antibody kit for the detection of inflammation was prepared aseptically in Class 1 Laminar Flow cabinet. The kit passed the sterility test. Upon reconstitution of the antibody kit with sodium pertechnetate-99m ( 99m Tc) solution, the labelling efficiency obtained was more than 95%. This preparation was stable up to 24-hour stored at room temperature. Gamma camera scans showed the accumulation of technetium-99m labelled antibody ( 99m Tc-HIgG) at the turpentine-induced inflammation of female Sprague-Dawley rats. This indicated the possibility of using 99m Tc-HIgG for inflammation detection. (author)

Methods to obtain radiolabelled monocrotaline

International Nuclear Information System (INIS)

Lame, M.W.; Morin, D.; Wilson, D.W.; Segall, H.J.

1996-01-01

Crotalaria spectabilis, a plant found in many areas of the world is associated with the pyrrolizidine alkaloid monocrotaline. Monocrotaline when injected subcutaneously in Sprague Dawley rats has been utilized for years to create a condition known to mimic pulmonary hypertension in humans. We attempted to determine the optimum conditions for the biosynthesis of radiolabelled monocrotaline. Our work describes the plant growth conditions and the time periods associated with the production of radiolabelled monocrotaline. In addition, the incorporation of 14 CO 2 or [2,3- 3 H]-putrescine dihydrochloride and the specific activity plus the amount(s) of recovered radiolabelled monocrotaline are discussed. We conclude that the most efficient and cost effective method for the biosynthesis of radiolabelled monocrotaline is still the utilization of 14 CO 2 . (author)

Affinity chromatography: A versatile technique for antibody purification.

Science.gov (United States)

Arora, Sushrut; Saxena, Vikas; Ayyar, B Vijayalakshmi

2017-03-01

Antibodies continue to be extremely utilized entities in myriad applications including basic research, imaging, targeted delivery, chromatography, diagnostics, and therapeutics. At production stage, antibodies are generally present in complex matrices and most of their intended applications necessitate purification. Antibody purification has always been a major bottleneck in downstream processing of antibodies, due to the need of high quality products and associated high costs. Over the years, extensive research has focused on finding better purification methodologies to overcome this holdup. Among a plethora of different techniques, affinity chromatography is one of the most selective, rapid and easy method for antibody purification. This review aims to provide a detailed overview on affinity chromatography and the components involved in purification. An array of support matrices along with various classes of affinity ligands detailing their underlying working principles, together with the advantages and limitations of each system in purifying different types of antibodies, accompanying recent developments and important practical methodological considerations to optimize purification procedure are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Production of antibodies which recognize opiate receptors on murine leukocytes

Energy Technology Data Exchange (ETDEWEB)

Carr, D.J.J.; Bost, K.L.; Blalock, J.E.

1988-01-01

An antibody has been developed which recognizes opiate receptors on cells of the immune system. This antibody blocks specific binding of the radiolabeled opiate receptor ligand, /sup 3/H-dihydromorphine, to receptors on murine splenocytes. Additionally, the anti-receptor antibody competes with ..beta..-endorphin, meta-enkephalin, and naloxone for the same binding site on the leukocytes. Moreover, the anti-receptor antibody possesses agonist activity similar to ..beta..-endorphin in suppressing cAMP production by lymphocytes. These results suggest the development of an antibody which recognizes classical opiate receptors on cells of the immune system.

SPECT assay of radiolabeled monoclonal antibodies

International Nuclear Information System (INIS)

Jaszczak, R.J.

1992-02-01

The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ( 123 I, 131 I, and 111 In) and with another radionuclide, 211 At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for 111 In and 123 I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches

Methods to obtain radiolabelled monocrotaline

Energy Technology Data Exchange (ETDEWEB)

Lame, M.W.; Morin, D.; Wilson, D.W.; Segall, H.J. [University of California, Davis, CA (United States)

1996-12-01

Crotalaria spectabilis, a plant found in many areas of the world is associated with the pyrrolizidine alkaloid monocrotaline. Monocrotaline when injected subcutaneously in Sprague Dawley rats has been utilized for years to create a condition known to mimic pulmonary hypertension in humans. We attempted to determine the optimum conditions for the biosynthesis of radiolabelled monocrotaline. Our work describes the plant growth conditions and the time periods associated with the production of radiolabelled monocrotaline. In addition, the incorporation of {sup 14}CO{sub 2} or [2,3-{sup 3}H]-putrescine dihydrochloride and the specific activity plus the amount(s) of recovered radiolabelled monocrotaline are discussed. We conclude that the most efficient and cost effective method for the biosynthesis of radiolabelled monocrotaline is still the utilization of {sup 14}CO{sub 2}. (author).

Microassay for measurement of binding of radiolabelled ligands to cell surface molecules

International Nuclear Information System (INIS)

Woof, J.M.; Burton, D.R.

1988-01-01

An improved technique for measuring the binding of radiolabelled ligands to cell surface molecules has been developed by modification of a procedure using centrifugation through a water-immiscible oil to separate free and cell-bound ligand. It maximises the percentage of ligand bound since cell-bound and free ligand can be separated easily and reproducibly even when very small reaction volumes are used. This permits low levels of ligand radiolabelling and relatively low numbers of cells to be used

Radiolabeled anti-EGFR-antibody improves local tumor control after external beam radiotherapy and offers theragnostic potential

International Nuclear Information System (INIS)

Koi, Lydia; Bergmann, Ralf; Brüchner, Kerstin; Pietzsch, Jens; Pietzsch, Hans-Jürgen; Krause, Mechthild

2014-01-01

Purpose: The effect of radioimmunotherapy (RIT) using the therapeutic radionuclide Y-90 bound to the anti-EGFR antibody cetuximab combined with external beam irradiation (EBRT) (EBRIT) on permanent local tumor control in vivo was examined. Methods: Growth delay was evaluated in three human squamous cell carcinoma models after RIT with [ 90 Y]Y-(CHX-A′′-DTPA) 4 -cetuximab (Y-90-cetuximab). The EBRT dose required to cure 50% of the tumors (TCD 50 ) for EBRT alone or EBRIT was evaluated in one RIT-responder (FaDu) and one RIT-non-responder (UT-SCC-5). EGFR expression and microenvironmental parameters were evaluated in untreated tumors, bioavailability was visualized by PET using ([ 86 Y]Y-(CHX-A′′-DTPA) 4 -cetuximab (Y-86-cetuximab) and biodistribution using Y-90-cetuximab. Results: In UT-SCC-8 and FaDu but not in UT-SCC-5 radiolabeled cetuximab led to significant tumor growth delay. TCD 50 after EBRT was significantly decreased by EGFR-targeted RIT in FaDu but not in UT-SCC-5. In contrast to EGFR expression, parameters of the tumor micromilieu and in particular the Y-90-cetuximab biodistribution or Y-86-cetuximab visualization in PET correlated with the responsiveness to RIT or EBRIT. Conclusion: EGFR-targeted EBRIT can improve permanent local tumor control compared to EBRT alone. PET imaging of bioavailability of labeled cetuximab appears to be a suitable predictor for response to EBRIT. This theragnostic approach should be further explored for clinical translation

Comparative tumour localization properties of radiolabelled monoclonal antibody preparations of defined immunoreactivities

International Nuclear Information System (INIS)

Pimm, M.V.; Baldwin, R.W.

1987-01-01

The immunoreactive fraction of an anti-CEA monoclonal antibody preparation has been progressively decreased by the addition of increasing proportions of impurity in the form of immunologically inert mouse immunoglobulin. Following radioiodination, the immunoreactive fractions of the preparations were determined and their localization in a human tumour xenograft in nude mice was assessed. There was a progressive decline in tumour localization, from tumour to blood ratios of 2:1 with unadulterated antibody to 0.6:1 with preparations only 15% with respect to the initial antibody. These findings demonstrate that the immunoreactive fraction of monoclonal antibody preparations is a major limiting factor in tumour localization and this has implications for experimental and clinical applications of monoclonal antibodies. (orig.)

Radiolabeling of anti-CD20 with Re0-188: liquid kit

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: carlarobertab@yahoo.com.br; jaosso@ipen.br

2007-07-01

Radioimmunotherapy uses the targeting features of monoclonal antibody to deliver radiation from an attached radionuclide. The radionuclide {sup 188}Re is currently produced from the father nuclide {sup 188}W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E{sub {beta}}{sub MAX} =2.1 MeV, t{sub 1/2}=16.9 h, E{sub {gamma}}=155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agents and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of radiolabeling of anti-CD20 with {sup 188}Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-ME and purified over a PD-10 column. The number of resulting free SH was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent, reaction time and {sup 188}Re volume in the liquid kit. Radiochemical purity of {sup 188}Re-anti-CD20 was evaluated. An average of 12 SH groups per mol in the reductions was found. The best labeling efficiency (> 93%) was achieved in the following conditions: 1 mg anti-CD20; 82.8 mg sodium tartrate; 1 mg SnCl{sub 2}; 0.25 mg gentisic acid, 1 mL {sup 188}Re and reaction time of 1 hour at room temperature. (author)

Radiolabeled Antibody Fragment for Preparation of (177Lu-DOTAm-PAMAM G3.0-F(ab’2 trastuzumab as a Radiopharmaceutical for Cancer Therapy

Directory of Open Access Journals (Sweden)

R.D. Haryuni

2017-06-01

Full Text Available Several radiolabeled monoclonal antibodies (mAbs have been used as radioimmunotherapy (RIT agents for cancer therapy. The use of mAbs as RIT agents is due to their ability to carry effectors, in the form of radionuclides which emit alpha (α particles, beta (β particles, or auger electrons, and bind specifically to cancer expressed receptor. This paper reports the preparation of radiolabelled trastuzumab in form of (177Lu-DOTAm-PAMAM G3-F(ab'2-trastuzumab, which will be expected as a potential RIT agent for therapy of breast cancer overexpressed human epidermal growth factor receptor 2 (HER2. Due to its reduced molecular weight, the use of F(ab'2-trastuzumab on the aforementioned RIT agent candidate is expected to reach its target much faster compared to the intact trastuzumab. Meanwhile, the role of PAMAM G3 is to increase the specific activity of the radiotherapeutic agent of Lu-177 due to the ability of its 32 –NH2 functional groups that are able to bind many DOTAs (£ 31 which in turn can bind a large number of 177Lu. The preparation was initiated by fragmentation of trastuzumab using pepsin enzyme in 0.02 M acetic acid buffer with a pH of 4.5 to produce F(ab'2-trastuzumab with a purity of 95 % after purification with PD-10 column. The F(ab'2-trastuzumab was then reacted with succinimidyl 4-(N-maleimidomethyl cyclohexane-1-carboxylate (SMCC to produce SMCC-F(ab'2-trastuzumab. The next reaction was to conjugate SMCC-F(ab'2-trastuzumab with DOTA-PAMAM G3.0-SH, which was prepared by reaction NHS-DOTA with PAMAM G3.0 and followed by reacting it with 2-iminothiolane to give (DOTAm-PAMAM G3.0-F(ab'2-trastuzumab. Finally, the (DOTAm-PAMAM G3.0-F(ab'2-trastuzumab was radiolabelled with 177Lu to produce (177Lu-DOTAm-PAMAM G3.0-F(ab'2-trastuzumab, resulting in a radiochemical purity of 98 % after purification with PD-10 column.Received: 31 October 2015; Revised: 30 June 2016; Accepted: 25 September 2016

Primary hepatocellular carcinoma localised by a radiolabelled monoclonal antibody

Energy Technology Data Exchange (ETDEWEB)

Markham, N; Ritson, A; James, O; Curtin, N; Bassendine, M; Sikora, K

1986-01-01

A rat monoclonal antibody, YPC2/38.8, was selected from a panel of antibodies derived by immunising rats with fresh human colorectal carcinoma. It was found to bind to a 30,000 dalton protein present on the cell surface of normal colon and liver. This protein was increased 10-fold on primary hepatocellular carcinoma (PHC) cells. After labelling with /sup 131/I, YPC2/38.8 was shown to localise human PHCs grown as xenografts in immunosuppressed mice. The authors conclude that YPC2/38.8 may have potential for diagnostic localisation and possibly thence for the selective targeting of drugs or toxins in patients with PHC arising in a liver unaffected by significant parenchymal disease. 16 refs.; 4 figs.; 1 table.

Selective radiolabeling of cell surface proteins to a high specific activity

International Nuclear Information System (INIS)

Thompson, J.A.; Lau, A.L.; Cunningham, D.D.

1987-01-01

A procedure was developed for selective radiolabeling of membrane proteins on cells to higher specific activities than possible with available techniques. Cell surface amino groups were derivatized with 125 I-(hydroxyphenyl)propionyl groups via 125 I-sulfosuccinimidyl (hydroxyphenyl)propionate ( 125 II-sulfo-SHPP). This reagent preferentially labeled membrane proteins exposed at the cell surface of erythrocytes as assessed by the degree of radiolabel incorporation into erythrocyte ghost proteins and hemoglobin. Comparison with the lactoperoxidase-[ 125 I]iodide labeling technique revealed that 125 I-sulfo-SHPP labeled cell surface proteins to a much higher specific activity and hemoglobin to a much lower specific activity. Additionally, this reagent was used for selective radiolabeling of membrane proteins on the cytoplasmic face of the plasma membrane by blocking exofacial amino groups with uniodinated sulfo-SHPP, lysing the cells, and then incubating them with 125 I-sulfo-SHPP. Exclusive labeling of either side of the plasma membrane was demonstrated by the labeling of some marker proteins with well-defined spacial orientations on erythroctyes. Transmembrane proteins such as the epidermal growth factor receptor on cultured cells could also be labeled differentially from either side of the plasma membrane

A fluorescence sedimentation assay for dsDNA antibodies

DEFF Research Database (Denmark)

Duus, K; Draborg, A H; Güven, E

2017-01-01

The Farr assay is a radioimmunoassay (RIA) for dsDNA antibodies, based on antibody precipitation using ammonium sulphate and quantification using radio-labelled dsDNA. The RIA-Farr assay offers outstanding clinical specificity and sensitivity for systemic lupus erythematosus (SLE) compared to other...... on precipitation with polyethylene glycol (PEG) and fluorescence of EvaGreen intercalated in dsDNA as detection principle. As dsDNA antibodies are quantified using fluorescence, the disadvantages of working with radioactivity are eliminated. The Fluoro-Farr assay was developed and validated, and the diagnostic...

Radiolabeled derivatives of folic acid

International Nuclear Information System (INIS)

1980-01-01

Derivatives of folic acid are described, in which the α-carboxyl group is substituted with an amino compound having an aromatic or heterocyclic ring substituent which is capable of being radiolabelled. Particularly mentioned as a radiolabel is 125 I. (author)

Radiolabeled cetuximab plus whole-brain irradiation (WBI) for the treatment of brain metastases from non-small cell lung cancer (NSCLC)

International Nuclear Information System (INIS)

Rades, Dirk; Nadrowitz, Roger; Buchmann, Inga; Meller, Birgit; Hunold, Peter; Noack, Frank; Schild, Steven E.

2010-01-01

Background and Purpose: The addition of systemic drugs to whole-brain irradiation has not improved the survival of patients with multiple brain metastases, most likely because the agents did not readily cross the blood-brain barrier (BBB). Radiolabeling of cetuximab was performed to investigate whether this antibody crosses the BBB. Case Report: A patient with multiple brain lesions from non-small cell lung cancer was investigated. The largest metastasis (40 x 33 x 27 mm) was selected the reference lesion. On day 1, 200 mg/m 2 cetuximab (0.25% hot and 99.75% cold antibody) were given. On day 3, 200 mg/m 2 cetuximab (cold antibody) were given. Weekly doses of 250 mg/m 2 cetuximab were administered for 3 months. Results: The reference lesion showed enhancement of radiolabeled cetuximab ( 123 I-Erbi) on scintigraphy; 123 I-Erbi crossed the BBB and accumulated in the lesion. The reference lesion measured 31 x 22 x 21 mm at 4 months. Enhancement of contrast medium was less pronounced. Conclusion: This is the first demonstration of cetuximab crossing the BBB and accumulating in brain metastasis. (orig.)

Radiolabeled cetuximab plus whole-brain irradiation (WBI) for the treatment of brain metastases from non-small cell lung cancer (NSCLC)

Energy Technology Data Exchange (ETDEWEB)

Rades, Dirk; Nadrowitz, Roger [Dept. of Radiation Oncology, Univ. of Luebeck (Germany); Buchmann, Inga; Meller, Birgit [Section of Nuclear Medicine, Univ. of Luebeck (Germany); Hunold, Peter [Dept. of Radiology, Univ. of Luebeck (Germany); Noack, Frank [Inst. of Pathology, Univ. of Luebeck (Germany); Schild, Steven E. [Dept. of Radiation Oncology, Mayo Clinic, Scottsdale, AZ (United States)

2010-08-15

Background and Purpose: The addition of systemic drugs to whole-brain irradiation has not improved the survival of patients with multiple brain metastases, most likely because the agents did not readily cross the blood-brain barrier (BBB). Radiolabeling of cetuximab was performed to investigate whether this antibody crosses the BBB. Case Report: A patient with multiple brain lesions from non-small cell lung cancer was investigated. The largest metastasis (40 x 33 x 27 mm) was selected the reference lesion. On day 1, 200 mg/m{sup 2} cetuximab (0.25% hot and 99.75% cold antibody) were given. On day 3, 200 mg/m{sup 2} cetuximab (cold antibody) were given. Weekly doses of 250 mg/m{sup 2} cetuximab were administered for 3 months. Results: The reference lesion showed enhancement of radiolabeled cetuximab ({sup 123}I-Erbi) on scintigraphy; {sup 123}I-Erbi crossed the BBB and accumulated in the lesion. The reference lesion measured 31 x 22 x 21 mm at 4 months. Enhancement of contrast medium was less pronounced. Conclusion: This is the first demonstration of cetuximab crossing the BBB and accumulating in brain metastasis. (orig.)

Antibody conjugate radioimmunotherapy of superficial bladder cancer

International Nuclear Information System (INIS)

Perkins, Alan; Hopper, Melanie; Murray, Andrea; Frier, Malcolm; Bishop, Mike

2002-01-01

The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C 595 (gG3) which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radio immuno conjugates of the C 595 antibody have been produced with high radiolabelling efficiency and immuno reactivity using Tc-99 m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun. (author)

Radiolabeling of rituximab with 188Re and 99mTc using the tricarbonyl technology

International Nuclear Information System (INIS)

Dias, Carla Roberta; Jeger, Simone; Osso, Joao Alberto; Mueller, Cristina; De Pasquale, Christine; Hohn, Alexander; Waibel, Robert; Schibli, Roger

2011-01-01

Introduction: The most successful clinical studies of immunotherapy in patients with non-Hodgkin's lymphoma (NHL) use the antibody rituximab (RTX) targeting CD20 + B-cell tumors. Rituximab radiolabeled with β - emitters could potentiate the therapeutic efficacy of the antibody by virtue of the particle radiation. Here, we report on a direct radiolabeling approach of rituximab with the 99m Tc- and 188 Re-tricarbonyl core (IsoLink technology). Methods: The native format of the antibody (RTX wt ) as well as a reduced form (RTX red ) was labeled with 99m Tc/ 188 Re(CO) 3 . The partial reduction of the disulfide bonds to produce free sulfhydryl groups (-SH) was achieved with 2-mercaptoethanol. Radiolabeling efficiency, in vitro human plasma stability as well as transchelation toward cysteine and histidine was investigated. The immunoreactivity and binding affinity were determined on Ramos and/or Raji cells expressing CD20. Biodistribution was performed in mice bearing subcutaneous Ramos lymphoma xenografts. Results: The radiolabeling efficiency and kinetics of RTX red were superior to that of RTX wt ( 99m Tc: 98% after 3 h for RTX red vs. 70% after 24 h for RTX wt ). 99m Tc(CO) 3 -RTX red was used without purification for in vitro and in vivo studies whereas 188 Re(CO) 3 -RTX red was purified to eliminate free 188 Re-precursor. Both radioimmunoconjugates were stable in human plasma for 24 h at 37 o C. In contrast, displacement experiments with excess cysteine/histidine showed significant transchelation in the case of 99m Tc(CO) 3 -RTX red but not with pre-purified 188 Re(CO) 3 -RTX red . Both conjugates revealed high binding affinity to the CD20 antigen (K d =5-6 nM). Tumor uptake of 188 Re(CO) 3 -RTX red was 2.5 %ID/g and 0.8 %ID/g for 99m Tc(CO) 3 -RTX red 48 h after injection. The values for other organs and tissues were similar for both compounds, for example the tumor-to-blood and tumor-to-liver ratios were 0.4 and 0.3 for 99m Tc(CO) 3 -RTX red and for 188 Re

New surface radiolabeling schemes of super paramagnetic iron oxide nanoparticles (SPIONs) for biodistribution studies.

Science.gov (United States)

Nallathamby, Prakash D; Mortensen, Ninell P; Palko, Heather A; Malfatti, Mike; Smith, Catherine; Sonnett, James; Doktycz, Mitchel J; Gu, Baohua; Roeder, Ryan K; Wang, Wei; Retterer, Scott T

2015-04-21

Nanomaterial based drug delivery systems allow for the independent tuning of the surface chemical and physical properties that affect their biodistribution in vivo and the therapeutic payloads that they are intended to deliver. Additionally, the added therapeutic and diagnostic value of their inherent material properties often provides extra functionality. Iron based nanomaterials with their magnetic properties and easily tailorable surface chemistry are of particular interest as model systems. In this study the core radius of the iron oxide nanoparticles (NPs) was 14.08 ± 3.92 nm while the hydrodynamic radius of the NPs, as determined by Dynamic Light Scattering (DLS), was between 90-110 nm. In this study, different approaches were explored to create radiolabeled NPs that are stable in solution. The NPs were functionalized with polycarboxylate or polyamine surface functional groups. Polycarboxylate functionalized NPs had a zeta potential of -35 mV and polyamine functionalized NPs had a zeta potential of +40 mV. The polycarboxylate functionalized NPs were chosen for in vivo biodistribution studies and hence were radiolabeled with (14)C, with a final activity of 0.097 nCi mg(-1) of NPs. In chronic studies, the biodistribution profile is tracked using low level radiolabeled proxies of the nanoparticles of interest. Conventionally, these radiolabeled proxies are chemically similar but not chemically identical to the non-radiolabeled NPs of interest. This study is novel as different approaches were explored to create radiolabeled NPs that are stable, possess a hydrodynamic radius of <100 nm and most importantly they exhibit an identical surface chemical functionality as their non-radiolabeled counterparts. Identical chemical functionality of the radiolabeled probes to the non-radiolabeled probes was an important consideration to generate statistically similar biodistribution data sets using multiple imaging and detection techniques. The radiolabeling approach

Research co-ordination meeting on labelling, quality control and clinical evaluation of monoclonal antibodies for scintigraphy, Kuala Lumpur, Malaysia, 9-13 September 1991

International Nuclear Information System (INIS)

1991-09-01

The Co-ordinated Research Programme (CRP) on ''Labelling, quality control and clinical evaluation of monoclonal antibodies for scintigraphy'' arose from the deliberations at an IAEA Consultants' Meeting (CM) on ''Radiolabelling techniques of monoclonal antibodies'' held in Vienna on 22-24 August 1988. The following is a brief description of the relevant recommendations arising from said meeting. A more detailed description of the proceedings may be found in the summary report issued on 8 December 1989. This report incorporates the results of the first Research Co-ordination Meeting (RCM) of subject CRP held in Kuala Lumpur, Malaysia on 9-13 September 1991. 9 refs

Radiolabeled platelets

International Nuclear Information System (INIS)

Datz, F.L.; Taylor, A.T.

1986-01-01

Initial interest in developing techniques to radiolabel platelets was spurred by the lack of an accurate method for measuring platelet life span in both normals and in thrombocytopenic patients. Early investigators could obtain only rough estimates of platelet life spans by monitoring the platelet counts of thrombocytopenic patients undergoing platelet transfusions. Labels were also sought that would allow imaging of platelets in vivo in order to better understand the pathophysiology of atherosclerosis, thrombophlebitis, and clotting disorders, and to improve the clinical diagnosis of these diseases. Two types of platelet labels were investigated: cohort (pulse) labels and random labels. Cohort labels are taken up by megakaryocytes in the bone marrow and incorporated in the DNA and other components of the forming platelet. In theory, only freshly released platelets of a uniform age are labeled. Random labels, on the other hand, tag platelets in the peripheral blood, labeling platelets of all ages

The effect of high antigen density on solid-phase radioimmunoassays for antibody regardless of immunoglobulin class

International Nuclear Information System (INIS)

Rubin, R.L.; Hardtke, M.A.; Carr, R.I.

1980-01-01

Human sera containing antibody to casein or to bovine serum albumin were used to assess the validity and utility of a solid-phase assay for quantitating antibody activity. Rabbit anti-human immunoglobulin radiolabeled with 125 I and capable of reacting with all human immunoglobulin classes was used to detect antibody bound to antigen immobilized to polystyrene tubes by a new covalent technique. This method results in very high antigen concentrations in highly stable association with polystyrene tubes. Kinetic and absorption studies demonstrated that low avidity antibodies are better detected when antigen is immobilized by the covalent method than when passively adsorbed. Conditions are described for minimizing artifactual interactions and for obtaining results similar to those obtained with conventional, liquid-phase assays. Failure to reach equilibrium in solid-phase assays and other problems are proposed to explain, in part, the inability to obtain a better correlation between solid- and liquid-phase immunoassays. (Auth.)

Immunoradiometric assay for cytomegalovirus-specific IgG antibodies; Assay development and evaluation in blood transfusion practice

Energy Technology Data Exchange (ETDEWEB)

Klapper, P.E.; Cleator, G.M.; Prinja-Wolks, D.; Morris, D.J. (Medical School, Manchester (United Kingdom). Department of Medical microbiology, Virology Unit); Morell, G. (Regional Blood Transfusion Centre, manchester (United Kingdom))

1990-03-01

An immunoradiometric assay (radio-immunosorbent test; RIST) for the detection of IgG antibodies to human herpesvirus 4 (human cytomegalovirus (CMV)) has been developed. The technique utilizes CMV antigen passively adsorbed to a polyvinyl microtitration plate and a radiolabelled murine monoclonal anti-human IgG antibody to detect binding of human antibody to the 'solid phase' reagent. The assay was optimized, and its specifity confirmed by testing paired acute and convalescent sera from patients with acute CMV or other human herpesvirus infections. To determine the assay's sensitivity 1433 blood donor sera were examined. The RIST was more sensitive than a standard complement fixation (CFT). Use of a monoclonal anti-human IgG antibody in the RIST reduced non-specific binding to the control uninfected cell antigen such that blood donor sera could be tested in the assay using only a CMV antigen without generating an unacceptable false positive rate. (author). 23 refs.; 1 tab.

Compartmental modeling approach to the radiation dosimetry of radiolabeled antibody

International Nuclear Information System (INIS)

Zanzonico, P.B.; Bigler, R.E.; Primus, F.J.; Alger, E.; DeJager, R.; Stowe, S.; Ford, E.; Brennan, K.; Goldenberg, D.M.

1986-01-01

Essential for the calculation of absorbed doses from systemically administered radiolabled antibody is the determination of the total number of nuclear transformations in specified source regions. Compartmental analysis (using biodistribution data augmented with a priori physiological information), unlike simply integrating empirical time-activity curves, may enable one to calculate the cumulated activity in unsampled as well as sampled source regions. These may include microscopic source regions (e.g. the intracellular space, cell surface, and extracellular space) important for microdosimetry calculations. Of particular importance is the interaction between the anti-tumor antibody and the tumor antigen. 30 references, 9 figures, 2 tables

Development of monoclonal-antibody-based products for medical research and diagnostic imaging. Technical report, 28 January 1987-31 December 1988 (Final)

International Nuclear Information System (INIS)

Rhodes, B.A.; Pant, K.D.; Chauhan, N.; Buckelew, J.; Budd, P.

1989-04-01

Two major areas of application of monoclonal antibodies were examined: the development of products to support the 'Antibody Delivery System', a parent-specific and variable antibody formula drug system for use in imaging and treatment of cancer, and the development of an antibody-based radiopharmaceutical for imaging occult abscesses and other conditions involving high concentrations of white blood cells. In development of the Antibody Delivery System components, methods for characterization and purification of monoclonal antibodies were developed and validated; a dot immunoassay test, under the name RhoDot (TM) Immunoassay, was developed for matching antibodies to putative tumor specimen: a radioimmunoassay, under the name PhoChek (TM) Quality Control Test Kit for Radiolabeled Antibodies, was developed and commercialized for measuring the immunoreactive fraction of radiolabeled antibodies specific to colorecal cancer; and a patient-specific quality control test was developed. In development of the antibody-based radiopharmaceutical for imaging occult abscesses, a candidate antibody was identified and produced under U.S. Food and Drug Administration standards preparatory to human clinical trials

Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with 131I

International Nuclear Information System (INIS)

Avcibasi, Ugur; Avcibasi, Nesibe; Unak, Turan; Unak, Perihan; Mueftueler, Fazilet Zuemruet; Yildirim, Yeliz; Dincalp, Haluk; Guemueser, Fikriye Guel; Dursun, Ebru Rueksen

2008-01-01

The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with 131 I ( 131 I-APH and 131 I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with 131 I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of 131 I-APH and 131 I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as 125 I, 123 I and 124 I as imaging and therapeutic agents in nuclear medical applications

Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with (131)I.

Science.gov (United States)

Avcibaşi, Uğur; Avcibaşi, Nesibe; Unak, Turan; Unak, Perihan; Müftüler, Fazilet Zümrüt; Yildirim, Yeliz; Dinçalp, Haluk; Gümüşer, Fikriye Gül; Dursun, Ebru Rükşen

2008-05-01

The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with (131)I ((131)I-APH and (131)I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with (131)I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of (131)I-APH and (131)I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as (125)I, (123)I and (124)I as imaging and therapeutic agents in nuclear medical applications.

Direct labelling of monoclonal antibodies with 99Tcm. Assessment of labelling, stability, immunoreactivity and biodistribution

International Nuclear Information System (INIS)

Janoki, G.A.

1998-01-01

Reduction of disulfide bonds to sulfhydryl groups for direct radiolabelling of monoclonal antibodies for immunoscintigraphic application continues to be of significant interest. Reducing agents that have been used are the following: stannous ion, 2-mercaptoethanol, dithiothreitol, dithioerythriol, and ascorbic acid. The radiolabelling of the reduced and purified antibody is performed via Sn 2+ reduction of pertechnetate in the presence of an excess of a low-affinity chelating ligand. In a recent work the 2-mercaptoethanol (2-ME) reduction based method was studied by using different analytical and biological techniques. Human IgG (Sandoglobulin), anti-CEA MoAb (ior-1), and anti-granulocyte MoAb (MAK 47), were reduced with 2-ME at two different molar ratios. To determine the amount of contaminating mercaptoethanol which may have survived the gel-filtration step 14 C-ME was used. The number of the free endogenous sulfhydryl groups generated by reduction was determined by Ellman's reagent; absorbance was measured at 412 nm. Within the quality assurance procedure of the 3 freeze dried kits the labelling efficiency, stability, pH, sterility, apyrogenicity, vial yield, syringe retention, filterable activity, free SH determination and animal distribution were studied again. After receiving permission from local ethics committee pilot human studies were initiated. Study protocols were also approved

Platelet antibodies of the IgM class in immune thrombocytopenic purpura

International Nuclear Information System (INIS)

Cines, D.B.; Wilson, S.B.; Tomaski, A.; Schreiber, A.D.

1985-01-01

The clinical course and response to therapy of patients with immune thrombocytopenic purpura (ITP) are not completely determined by the level of IgG present on the platelet surface. It is possible that antibodies of other immunoglobulin classes also play a role in platelet destruction in some of these patients. Therefore, the authors studied 175 patients with ITP for the presence of IgM anti-platelet antibodies using radiolabeled polyclonal or monoclonal anti-IgM. They observed that 57% of patients with clinical ITP had increased levels of IgM on their platelets, compared with normal controls and patients with thrombocytopenia who did not have ITP. They obtained similar results using either radiolabeled polyclonal or monoclonal anti-IgM, reagents whose integrity was first characterized using erythrocytes coated with defined amounts of IgM antibody. Among patients with increased platelet-IgM there was a significant correlation both with the presence of increased platelet-C3 as well as the amount of platelet-C3. The authors demonstrated the presence of warm-reacting IgM anti-platelet antibodies in the plasma of two of these patients who were further studied. These studies demonstrate the presence of warm-reacting IgM anti-platelet antibodies in some patients with ITP. They suggest that the binding of complement to platelets by IgM antibodies may initiate platelet clearance as well as enhance the effect of IgG antibodies in ITP

99mTC-dextran-antibody conjugates. Labelling procedures

International Nuclear Information System (INIS)

Marquez, M.; Westlin, J.E.; Nilsson, S.; Holmberg, A.R.

1996-01-01

Dextran forms stable chelates with 99m Tc, a radionuclide with ideal properties for planar scintigraphic and tomographic imaging. This study investigates some of the factors of importance to the formation of 99m Tc-dextran. The complex was used for the technetium labelling of a monoclonal antibody. Two radiolabelling methods were studied: Direct dextran labelling with the reductant dissolved in HCl and labelling via a weak 'transfer' chelator (tartaric acid) with the reductant dissolved in ethanol. Different conditions during the labelling reaction were studied. Finally, dextran was coupled to a monoclonal anticytokeratin antibody and the conjugate was subsequently radiolabelled with 99m Tc. Gel filtration (GFR) and thin layer chromatography (TLC) were compared as methods for estimation of the labelling efficiency. When using 10-500 μM of ligand, 5-100 μM SnC1 2 with 10-500 MBq of technetium at pH7 incubated for 10-15 min, the radiolabelling seemed optimal (70-75% labelling efficiency). It was found that 100 μM tartaric acid used as a weak intermediate chelator with SnCl 2 dissolved in ethanol improved the reproducibility of the labelling. The labelling efficiency was not affected by either the presence of oxygen or the addition of an oxygen scavenger during the labelling incubation. In general, TLC showed higher labelling efficiencies than GFR, indicating inadequate separation of the different moieties. (orig.)

Preparation and biological evaluation of radiolabelled antibodies with selected carbohydrate modifications

International Nuclear Information System (INIS)

Qi, P.; Koganty, R.R.; Selvaraj, S.

1993-01-01

Two carbohydrates, N-acetylgalactosamine (GalNAc) and galactose-β-1,3-GalNAc have been attached to human IgG (hIgG) by a novel linking reagent, hexafluoroglutaric acid dimethyl ester. Fluorine-19 NMR signals were used for the determination of the conjugation ratio. A third carbohydrate, sialic acid, was conjugated via reductive amination and the conjugation ratio determined by a resorcinol assay. The biological behaviour of these radiodinated antibodies with carbohydrate modification in normal mice indicates an enhanced liver uptake at 15 min post-injection with an associated change in circulating blood levels occurs for the galactose-based hIgG preparations. However, no significant differences in the biodistribution were observed for the sialic acid conjugate. These studies confirm the potential of carbohydrate-antibody conjugation for modifying the behaviour of antibodies in immunoscintigraphy and radioimmunotherapy. (author)

New surface radiolabeling schemes of super paramagnetic iron oxide nanoparticles (SPIONs) for biodistribution studies†

Science.gov (United States)

Nallathamby, Prakash D.; Mortensen, Ninell P.; Palko, Heather A.; Malfatti, Mike; Smith, Catherine; Sonnett, James; Doktycz, Mitchel J.; Gu, Baohua; Roeder, Ryan K.; Wang, Wei; Retterer, Scott T.

2016-01-01

Nanomaterial based drug delivery systems allow for the independent tuning of the surface chemical and physical properties that affect their biodistribution in vivo and the therapeutic payloads that they are intended to deliver. Additionally, the added therapeutic and diagnostic value of their inherent material properties often provides extra functionality. Iron based nanomaterials with their magnetic properties and easily tailorable surface chemistry are of particular interest as model systems. In this study the core radius of the iron oxide nanoparticles (NPs) was 14.08 ± 3.92 nm while the hydrodynamic radius of the NPs, as determined by Dynamic Light Scattering (DLS), was between 90–110 nm. In this study, different approaches were explored to create radiolabeled NPs that are stable in solution. The NPs were functionalized with polycarboxylate or polyamine surface functional groups. Polycarboxylate functionalized NPs had a zeta potential of –35 mV and polyamine functionalized NPs had a zeta potential of +40 mV. The polycarboxylate functionalized NPs were chosen for in vivo biodistribution studies and hence were radiolabeled with 14C, with a final activity of 0.097 nCi mg–1 of NPs. In chronic studies, the biodistribution profile is tracked using low-level radiolabeled proxies of the nanoparticles of interest. Conventionally, these radiolabeled proxies are chemically similar but not chemically identical to the non-radiolabeled NPs of interest. This study is novel as different approaches were explored to create radiolabeled NPs that are stable, possess a hydrodynamic radius of <100 nm and most importantly they exhibit an identical surface chemical functionality as their non-radiolabeled counterparts. Identical chemical functionality of the radiolabeled probes to the non-radiolabeled probes was an important consideration to generate statistically similar biodistribution data sets using multiple imaging and detection techniques. The radiolabeling approach

Isolation, purification, and radiolabeling of a novel 120-kD surface protein on Blastomyces dermatitidis yeasts to detect antibody in infected patients

International Nuclear Information System (INIS)

Klein, B.S.; Jones, J.M.

1990-01-01

No well-defined Blastomyces-specific antigens are currently available. We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify immunologically active molecules in the cell wall of B. dermatitidis. A major immunoreactive 120-kD protein (WI-1) was present in all five strains studied and comprised 5% of the protein in the cell wall extract obtained after freezing and thawing yeast cells. WI-1 was recognized by serum from all 10 patients with blastomycosis but by none of those from 5 patients with histoplasmosis. It was purified by electroelution, radiolabeled with 125I, and incorporated into a radioimmunoassay (RIA) for serodiagnosis of blastomycosis. Antibody to WI-1 was detected in 58 (85%) of 68 patients with blastomycosis (geometric mean titer, 1:2,981), in two (3%) of 73 patients with histoplasmosis, coccidioidomycosis, sporotrichosis, or candidiasis (titers, 1:86 and 1:91) and in none of 44 healthy persons. WI-1 was shown to be a surface molecule abundant on B. dermatitidis yeasts that were indirectly stained with serum from a rabbit immunized with WI-1. Approximately 0.93 pg of WI-1 or 4.7 x 10(6) WI-1 molecules were found on the surface of an individual yeast using an antigen-inhibition RIA; none was found on Histoplasma capsulatum or Candida albicans yeasts. We conclude that WI-1 is a novel, immunologically active surface molecule on the invasive form of B. dermatitidis and that WI-1 can be used to reliably detect antibody and study the immunopathogenesis of blastomycosis

Isolation, purification, and radiolabeling of a novel 120-kD surface protein on Blastomyces dermatitidis yeasts to detect antibody in infected patients

Energy Technology Data Exchange (ETDEWEB)

Klein, B.S.; Jones, J.M.

1990-01-01

No well-defined Blastomyces-specific antigens are currently available. We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify immunologically active molecules in the cell wall of B. dermatitidis. A major immunoreactive 120-kD protein (WI-1) was present in all five strains studied and comprised 5% of the protein in the cell wall extract obtained after freezing and thawing yeast cells. WI-1 was recognized by serum from all 10 patients with blastomycosis but by none of those from 5 patients with histoplasmosis. It was purified by electroelution, radiolabeled with 125I, and incorporated into a radioimmunoassay (RIA) for serodiagnosis of blastomycosis. Antibody to WI-1 was detected in 58 (85%) of 68 patients with blastomycosis (geometric mean titer, 1:2,981), in two (3%) of 73 patients with histoplasmosis, coccidioidomycosis, sporotrichosis, or candidiasis (titers, 1:86 and 1:91) and in none of 44 healthy persons. WI-1 was shown to be a surface molecule abundant on B. dermatitidis yeasts that were indirectly stained with serum from a rabbit immunized with WI-1. Approximately 0.93 pg of WI-1 or 4.7 x 10(6) WI-1 molecules were found on the surface of an individual yeast using an antigen-inhibition RIA; none was found on Histoplasma capsulatum or Candida albicans yeasts. We conclude that WI-1 is a novel, immunologically active surface molecule on the invasive form of B. dermatitidis and that WI-1 can be used to reliably detect antibody and study the immunopathogenesis of blastomycosis.

Langmuir hydrogen dissociation approach in radiolabeling carbon nanotubes and graphene oxide

International Nuclear Information System (INIS)

Badun, Gennadii A.; Chernysheva, Maria G.; Eremina, Elena A.; Egorov, Alexander V.; Grigorieva, Anastasia V.

2016-01-01

Carbon-based nanomaterials have piqued the interest of several researchers. At the same time, radioactive labeling is a powerful tool for studying processes in different systems, including biological and organic; however, the introduction of radioactive isotopes into carbon-based nanomaterial remains a great challenge. We have used the Langmuir hydrogen dissociation method to introduce tritium in single-walled carbon nanotubes and graphene oxide. The technique allows us to achieve a specific radioactivity of 107 and 27 Ci/g for single-layer graphene oxide and single-walled carbon nanotubes, respectively. Based on the analysis of characteristic Raman modes at 1350 and 1580 cm -1 , a minimal amount of structural changes to the nanomaterials due to radiolabeling was observed. The availability of a simple, nondestructive, and economic technique for the introduction of radiolabels to single-walled carbon nanotubes and graphene oxide will ultimately expand the applicability of these materials.

Langmuir hydrogen dissociation approach in radiolabeling carbon nanotubes and graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Badun, Gennadii A.; Chernysheva, Maria G.; Eremina, Elena A.; Egorov, Alexander V. [Lomonosov Moscow State Univ. (Russian Federation). Dept. of Chemistry; Grigorieva, Anastasia V. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Dept. of Materials Science

2016-11-01

Carbon-based nanomaterials have piqued the interest of several researchers. At the same time, radioactive labeling is a powerful tool for studying processes in different systems, including biological and organic; however, the introduction of radioactive isotopes into carbon-based nanomaterial remains a great challenge. We have used the Langmuir hydrogen dissociation method to introduce tritium in single-walled carbon nanotubes and graphene oxide. The technique allows us to achieve a specific radioactivity of 107 and 27 Ci/g for single-layer graphene oxide and single-walled carbon nanotubes, respectively. Based on the analysis of characteristic Raman modes at 1350 and 1580 cm{sup -1}, a minimal amount of structural changes to the nanomaterials due to radiolabeling was observed. The availability of a simple, nondestructive, and economic technique for the introduction of radiolabels to single-walled carbon nanotubes and graphene oxide will ultimately expand the applicability of these materials.

Radiolabeled peptides: experimental and clinical applications

International Nuclear Information System (INIS)

Thakur, M.L.; Pallela, V.R.

1998-01-01

Radiolabeled receptor specific biomolecules hold unlimited potential in nuclear medicine. During the past few years much attention has been drawn to the development radiolabeled peptides for a variety of diagnostic applications, as well as for therapy of malignant tumors. Although only one peptide, In-111-DTPA-(D)-Phe 1 -octreotide, is available commercially for oncologic imaging, many more have been examined in humans with hematological disorders, and the early results appear to be promising. Impetus generated by these results have prompted investigators to label peptides with such radionuclides as Tc-99m, I-123, F-18, Cu-64, and Y-90. This review is intended to highlight the qualities of peptides, summarize the clinical results, and address some important issues associated with radiolabeling of highly potent peptides. While doing so, various methods of radiolabeling have been described, and their strengths and weaknesses have also been discussed. (author)

Quantitative cumulative biodistribution of antibodies in mice

Science.gov (United States)

Yip, Victor; Palma, Enzo; Tesar, Devin B; Mundo, Eduardo E; Bumbaca, Daniela; Torres, Elizabeth K; Reyes, Noe A; Shen, Ben Q; Fielder, Paul J; Prabhu, Saileta; Khawli, Leslie A; Boswell, C Andrew

2014-01-01

The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn’s role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn’s role in antibody PK and catabolism at the tissue level. PMID:24572100

Exploration of novel strategies to enhance monoclonal antibodies targeting

International Nuclear Information System (INIS)

Khawli, L.A.; Epstein, A.L.

1997-01-01

This paper highlights the major obstacles and prospects of antibody targeting for the radio imaging and therapy of human malignant lymphomas and more challenging solid tumors. To improve the therapeutic potential of monoclonal antibodies, the authors have focused their attention on the development of new and successful methods to augment antibody uptake in the tumor. These approaches include the use of radiolabeled streptavidin to target biotinylated monoclonal antibodies already bound to tumor, pretreatment with vasoactive immunoconjugates, and the use of chemically modified antibodies. Because of the promising preclinical data obtained with these three newer approaches, plans are underway to test them in the clinic. More generally, these approaches are applicable to the use of other monoclonal antibody/tumor systems for the diagnosis and therapy of human cancers and related diseases

Radiolabeling of anti-CD20 with Re-188 for treatment of Non-Hodgkin's lymphoma: radiochemical control

International Nuclear Information System (INIS)

Dias, C.R.; Osso Junior, J.A.

2008-01-01

Radioimmunotherapy (RIT) uses target-specific monoclonal antibodies or fragments labeled with a radioactive isotope to combine humoral and radiolytic functions and has the advantage of targeting not only the cell to which the antibody is bound but also the surrounding tumor cells and microenvironment. The most successful clinical studies of RIT in patients with Non-Hodgkin's Lymphoma (NHL) have targeted CD20+ Bcell tumors. Antibody therapy directed against the CD20 antigen on the surface of B-cells is considered one of the first successful target-specific therapies in oncology. The radionuclide rhenium-188 ( 188 Re) is currently produced from the father nuclide 188 W through a transportable generator system. Because of its easy availability and suitable nuclear properties (E βMAX = 2.1 MeV, t1/2 = 16.9 h, E γ = 155 keV), this radionuclide is considered an attractive candidate for application as therapeutic agent and could be conveniently utilized for imaging and dosimetric purposes. The objective of this work is the optimization of direct radiolabeling method of anti-CD20 with 188 Re using a liquid formulation. Anti-CD20 was reduced by incubation with 2-mercaptoethanol at room temperature. The number of resulting free sulphydryl groups was assayed with Ellman's reagent. Optimization of radiolabeling was achieved by varying parameters: antibody mass, reducing agent mass, tartrate mass, stability and reaction time, 188 Re volume and activity. Radiochemical purity of 188 Re-anti-CD20 was evaluated using instant thin layer chromatography-silica gel (ITLC-SG). Quality control methods for evaluation of radiochemical purity showed good labeling yield of the antibody but further studies will be carried out in order to improve the labeling yields and consequently the specific activity of the product. (author)

In vitro and in vivo tumor models for studies of distribution of radiolabelled monoclonal antibodies and fragments

International Nuclear Information System (INIS)

Buchegger, F.; Halpern, S.E.; Sutherland, R.M.; Schreyer, M.; Mach, J.P.; Rochester Univ., NY

1986-01-01

Colon carcinoma multicellular spheroids were incubated in vitro with radiolabelled MAbs. The more rapid penetration of fragments as compared to intact MAbs was clearly demonstrated. For the study of antibody localization in tumors in vivo, the model of nude mice with ligated kidneys was used. Although very artificial, this model allowed to demonstrate that, without urinary excretion, Fab fragments accumulated more rapidly into the tumor than intact MAbs and disappeared faster from the blood. This difference was less striking for F(ab') 2 fragments. In the liver a decreased accumulation of both types of fragments as compared to intact MAbs was observed. Concerning radio-immunotherapy we think that Fab fragments are not useful because of their too short half-life the circulation and in tumor and because they will probably be too toxic for the kidneys. Intact MAbs and F(ab') 2 fragments have each their advantages. Intact MAbs show highest tumor accumulation in mice without ligated kidney, however, they remain mostly on the periphery of tumor nodules, as shown by autoradiography. F(ab') 2 fragments have been found to penetrate deeper into the tumor and to accumulate less in the liver. It might be therefore an advantage to combine intact MAbs with F(ab') 2 fragments, so that in the tumor two different regions could be attacked whereas in normal tissues toxicity could be distributed to different organs such as to the liver with intact MAbs and to the kidney with F(ab') 2 fragments. (orig.) [de

Monoclonal antibodies for radioimmunodetection of tumours and for targeting

International Nuclear Information System (INIS)

Baldwin, R.W.; Embleton, M.J.; Pimm, M.V.

1983-01-01

A monoclonal antibody 791T/36 prepared against human osteogenic sarcoma has been used to detect primary and metastatic colorectal carcinomas by external imaging of patients following injection of 131 I-labelled antibody. In 10 of 11 patients radiolabelled 791T/36 antibody localized in tumours, the tumour/non tumour ratio of radioactivity ranging from 1.5:1 to 8.1. 791T/36 antibody was also evaluated for its potential for targeting anti-tumour agents including cytotoxic drugs (Vindesine) and immunomodulating agents (interferon). Vindesine-791T/36 conjugates were preferentially cytotoxic in vitro for target cells expressing the 791T/36 anti-body defined antigen. Also interferon conjugated to 791T/36 antibody, like free interferon activated peripheral blood natural killer cell activity. These in vitro tests together with related studies on antibody localization in vivo indicate the potential of monoclonal antibody targeting of anti-tumour agents

Developing the 186 Re radiolabelling procedures of peptides and monoclonal antibodies

International Nuclear Information System (INIS)

Lungu, V.; Mihailescu, G.

1999-01-01

Mono and poli-clonal antibodies are the most recent candidate molecules for the radiopharmaceutical preparation used in radioimmunotherapy and radiodiagnostic. Our study presents results in 186 Re direct labelling of HIgG (Human Immunoglobulin G) poli-clonal antibody. The steps in labelling process are: 1. pre-reduction -S-S- bridges of HIgG molecule with ascorbic acid in pH = 3.5 - 4.5; 2. preparation of the reducing system for 186 ReO 4 - in presence of Sn 2+ ions excess and 3. coupling 186 Re (red) to -SH groups of biomolecules. The specific reactions of each step above are controlled by: incubation time and temperature, pH, molar ratio 186 Re: HIgG. 186 Re-HIgG samples were purified by gel elution chromatography method and the quality control was performed by chromatography techniques. To labelled of HIgG we effected the pre-reduction of -S-S- bridges of biomolecules to sulfhydryls using the following reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The pre-reduction reactions are controlled by mass ratios of reduction agent/biomolecule, pH, temperature and time of incubation. HIgG was the biomolecule used in the pre-reduction reactions. The specific parameters for each systems are presented. The stannous chloride was used as reducing agent in two systems, SnCl 2 : 0.05 N HCl and SnCl 2 : 20 mg/ml citric acid. The coupling reaction of 186 Re (red) with the biomolecule has been controlled by time and incubation temperature and the influence of pH regarding the binding of 186 Re to the biomolecule. 186 Re-HIgG was obtained by: i) incubation at the room temperature, 1 hour time of HIgG in thiol form and 186 Re in reducing form and ii) incubation of HIgG in thiol form, at 37 deg C and 22 hours time, with adding after pre-reduction of SnCl 2 and Na 186 ReO 4 . Quality control was effected by chromatography techniques (paper and gel chromatography) on labelled biomolecule before and after purification. The elution gel chromatography

A novel method for radiolabeling antigen-binding receptors of lymphocytes

International Nuclear Information System (INIS)

Choi, Y.S.; Lee, M.S.; Rosenspire, A.J.

1983-01-01

Antigen-binding receptor (ABR) molecules have been selectively radiolabeled and isolated from immunized chicken spleen cells. The specific radiolabeling of the receptors has been accomplished by utilizing a novel technique employing lactoperoxidase (LPO) covalently linked to antigen (Ag) for which human gammaglobulin was used. The cell surface ABRs were first bound to the Ag-LPO conjugates through specific recognition sites on the Ag portion of the conjugates. The bound LPO portions were then allowed to catalyze the radioiodination of the ABRs. After radiolabeling, cells were solubilized with detergents, ABRs still bound to Ag-LPO conjugates were directly isolated from the lysates via immunoaffinity chromatography utilizing an immunoaffinity reagent directed toward the antigen portion of the ABR-Ag-LPO complex. The radioactive materials were then analyzed via SDS-PAGE under reducing conditions. Most of the specifically-labeled and isolated materials were immunoglobulin (Ig). Both the membrane-bound form of the heavy chain as well as the secreted form were detected, along with the light chain. An additional polypeptide was also selectively labeled and isolated along with the Ig. This may be a molecule closely associated with the membrane immunoglobulin on the B-cell surface. (author)

Monoclonal antibodies reactive with human breast or ovarian carcinoma: In vivo applications

International Nuclear Information System (INIS)

Thor, A.D.; Edgerton, S.M.

1989-01-01

Monoclonal antibodies (MoAbs) are unique and useful bioprobes that allow in vivo targeting of membrane-associated or circulating antigens. Most of the clinical trials to date have used low dosages of radiolabeled MoAb given in a single dose. Newer studies have included antibody fragments, repeated injections, intraperitoneal (IP) administration, and other labels such as 90Y. Clinical MoAb trials are often arduous, expensive, and time-consuming to perform. Before human use, animal studies and extensive MoAb characterization are required. The production of pharmaceutical grade, radiolabeled MoAb is technically difficult and costly. Clinical trials require administrative and patient consent as well as extensive written protocols. These studies necessitate interdepartmental and intradepartmental cooperation and coordination. Furthermore, the use of in vivo radiolabeled probes impacts many levels of health care providers from janitorial, nursing, and technical staff to laboratories and physicians. Simple blood tests or disposal of body excretions may concern nursing or technical staff with the possibility of radiation exposure. The responsibility for study design, personnel involvement, and prospective use in patients without a definitive cancer diagnosis ultimately rests with the physician. While many issues have been addressed, additional clinical trials, consideration of safety issues, and standardization between institutions will be necessary before the use of radiolabeled MoAb for diagnosis, management, or therapy of human tumors becomes routine. Continued cooperation and funding should ensure its achievement. 136 references

Extraction, radiolabeling, and in vivo catabolism of autologous-origin equine fibrinogen and platelets in the healthy and exercise-stressed horse

International Nuclear Information System (INIS)

Coyne, C.P.

1986-01-01

Three separate techniques were evaluated for the extraction of autologous-origin fibrinogen from whole equine plasma. Rapid extraction of equine fibrinogen with ammonium sulfate-sodium phosphate buffer, in combination with saturated glycine buffer, provided the most practical means of obtaining a protein extract with the highest degree of biological activity and sufficiently high iodine-125 ( 125 I) radiolabeling efficiencies using monochloroiodine reagent (ICI). A technique was developed for the in vitro radiolabeling of equine platelets suspended in plasma. This entailed the use of the isotope, indium-111 ( 111 In), together with the lipophilic ligand, 2-(mercaptopyridine-N-oxide). This labeling technique achieved labeling efficiencies between 75% and 96%, and in vitro aggregability of 111 In-merc radiolabeled platelets was comparable to that of unlabeled cell isolates. In the final phase of the investigation, autologous-origin 125 I-labeled fibrinogen and 111 In-labeled platelets were applied in a series of equine exercise physiology studies. Elimination of these two radiobiologicals was evaluated in the resting and exercise-stressed horse. Results from these investigations revealed no long-term influence of exercise conditioning on the in vivo kinetics of radiolabeled fibrinogen or platelets

Method for radio imaging the myocardium of mammals using radio-labelled lipophil cations

International Nuclear Information System (INIS)

1984-01-01

The invention relates to a method for the radio imaging of myocardia of mammals by concentrating a radiolabelled cation in myocardial tissue and by producing a radiograph using imaging techniques. According to the invention, it is found that a group of substances shows a preference to myocardial tissues upon intravenous injection in mammals. The characteristic of the invention is that radiolabelled quaternary ammonium, quaternary phosphorous or quaternary arsenic compounds with at least two aryl groups are intravenously injected. These substances provide a sufficiently high radioactivity giving an approved diagnostic image of the myocardium. (G.J.P.)

Computer simulations and the use of radiolabelled sulphur colloid to measure the efficiency of the mononuclear phagocyte system

International Nuclear Information System (INIS)

Saad, A.H.; Rutishauser, S.C.B.; Williams, A.R.

1985-01-01

Techniques are described whereby the clearance of the radiolabelled blood borne colloid can be continuously and reproducibly measured non-invasively from the same animal in vivo or from the isolated perfused intact liver in vitro. Using these techniques, the rate of removal of radiolabelled sulphur colloid by the mononuclear phagocytes in vivo and in vitro was shown to be biexponential. The pattern of clearance of colloid and the factors contributing to this were analysed with the aid of a computer program which mimicked the in vitro liver perfusion. (Auth.)

Radiolabeling as a tool to study uptake pathways in plants

Energy Technology Data Exchange (ETDEWEB)

Schymura, Stefan; Hildebrand, Heike; Franke, Karsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Fricke, T. [Vita34 BioPlanta, Leipzig (Germany)

2017-06-01

The identification of major uptake pathways in plants is an important factor when evaluation the fate of manufactured nanoparticles in the environment and the associated risks. Using different radiolabeling techniques we were able to show a predominantly particulate uptake for CeO{sub 2} nanoparticles (NPs) in contrast to a possible uptake in the form of ionic cerium.

Highly sensitive radioimmunoassay technique for subtyping the antibody to hepatitis B surface antigen

Energy Technology Data Exchange (ETDEWEB)

Fang, C T; Nath, N; Berberian, H; Dodd, R Y [American Red Cross, Blood Research Laboratory, Bethesda, MD, USA

1978-12-01

A highly sensitive technique for determining the subtype specificity of antibody to hepatitis B surface antigen (anti-HBs) is described. Immunoadsorbent consisting of controlled pore glass coated with subtype specific HBsAg was used to remove homologous antibody from the test samples before testing them for residual antibody by a commercially available radioimmunoassay (RIA). A total of 73 anti-HBs-positive samples from asymptomatic blood donors were tested. In nearly 80% of these samples the subtype reactivity could be determined by this technique. Only 67% could be typed by conventional liquid phase absorption RIA and 22% by passive hemagglutination inhibition techniques. Among the samples with low anti-HBs titer, ad and ay subtypes were found with equal frequency; however, with the increase in anti-HBs titer, considerably higher proportion of ad specificity was detected.

Limitations in the use of low pH extraction to distinguish internalized from cell surface-bound radiolabeled antibody

International Nuclear Information System (INIS)

Ong, Gaik Lin; Mattes, M. Jules

2000-01-01

Internalization by cells of radiolabeled protein ligands bound to the cell surface is frequently analyzed by extraction of the cells with low pH buffers. This treatment supposedly strips the ligands from the cell surface, and remaining molecules are considered to be internalized. However, we show herein that: (1) low molecular weight catabolic products that are trapped within lysosomes (residualizing radiolabels) are efficiently extracted by low pH buffers, under the same conditions used to remove cell surface-bound material, and (2) low pH treatment lyses the majority of the cells, as shown with both a nonadherent and an adherent cell line, with the release of most of a 51 Cr label. Still, low pH extraction was effective at demonstrating Ab internalization, as has been demonstrated many times. These effects of low pH treatment may be attributed to the fixative properties of these buffers. Regardless of the mechanism, these data must be taken into consideration in interpreting the results of such experiments

Activated platelets in carotid artery thrombosis in mice can be selectively targeted with a radiolabeled single-chain antibody.

Directory of Open Access Journals (Sweden)

Timo Heidt

Full Text Available BACKGROUND: Activated platelets can be found on the surface of inflamed, rupture-prone and ruptured plaques as well as in intravascular thrombosis. They are key players in thrombosis and atherosclerosis. In this study we describe the construction of a radiolabeled single-chain antibody targeting the LIBS-epitope of activated platelets to selectively depict platelet activation and wall-adherent non-occlusive thrombosis in a mouse model with nuclear imaging using in vitro and ex vivo autoradiography as well as small animal SPECT-CT for in vivo analysis. METHODOLOGY/PRINCIPAL FINDINGS: LIBS as well as an unspecific control single-chain antibody were labeled with (111Indium ((111In via bifunctional DTPA ( = (111In-LIBS/(111In-control. Autoradiography after incubation with (111In-LIBS on activated platelets in vitro (mean 3866 ± 28 DLU/mm(2, 4010 ± 630 DLU/mm(2 and 4520 ± 293 DLU/mm(2 produced a significantly higher ligand uptake compared to (111In-control (2101 ± 76 DLU/mm(2, 1181 ± 96 DLU/mm(2 and 1866 ± 246 DLU/mm(2 indicating a specific binding to activated platelets; P<0.05. Applying these findings to an ex vivo mouse model of carotid artery thrombosis revealed a significant increase in ligand uptake after injection of (111In-LIBS in the presence of small thrombi compared to the non-injured side, as confirmed by histology (49630 ± 10650 DLU/mm(2 vs. 17390 ± 7470 DLU/mm(2; P<0.05. These findings could also be reproduced in vivo. SPECT-CT analysis of the injured carotid artery with (111In-LIBS resulted in a significant increase of the target-to-background ratio compared to (111In-control (1.99 ± 0.36 vs. 1.1 ± 0.24; P < 0.01. CONCLUSIONS/SIGNIFICANCE: Nuclear imaging with (111In-LIBS allows the detection of platelet activation in vitro and ex vivo with high sensitivity. Using SPECT-CT, wall-adherent activated platelets in carotid arteries could be depicted in vivo. These results encourage further studies elucidating the role of

Effect of antibody charge and concentration on deposition of antibody to glomerular basement membrane

International Nuclear Information System (INIS)

Madaio, M.P.; Salant, D.J.; Adler, S.; Darby, C.; Couser, W.G.

1984-01-01

Fixed anionic sites within the glomerular capillary wall influence the permeation of serum proteins, the localization of various antigens, and the deposition of antibody in the subepithelial space. In anti-GBM nephritis antibody deposition occurs very rapidly to antigenic sites located relatively proximal in the glomerular capillary wall. The authors examined the influence of the glomerular charge barrier on anti-GBM antibody deposition by comparing the rate of deposition of antibodies with cationic and anionic isoelectric points. Purified sheep anti-rat GBM IgG was isolated from acid eluates of kidneys obtained 24 hr after rats were injected with sheep antiserum to rat GBM. Anti-GBM IgG was separated into cationic (pI 6.4-8.5) and anionic (pI 4.2-6.8) fractions, which were radiolabelled with 131 I and 125 I, respectively, shown to have equal antibody contents measured by in vitro binding to normal glomeruli, mixed in equal amounts, and injected in incremental doses to ten rats. At 1 hr the glomerular antibody binding of each fraction was directly related to the blood level (r . 0.95, r . 0.97) and delivery of antibody (r . 0.98, r . 0.98). Glomerular binding of cationic antibody was four times greater than anionic antibody over the entire range of deliveries studied (P less than 0.001). The authors conclude that glomerular deposition of anti-GBM antibody is directly related to blood concentration and delivery of antibody. Furthermore, the deposition of cationic antibodies to GBM antigens was significantly greater than the deposition of anionic antibodies

Measurement of IgG antibodies to house dust mite and grass pollen by a solid-phase radioimmunoassay

Energy Technology Data Exchange (ETDEWEB)

Delespesse, G; Debisschop, M J; Flament, J [Hopital Saint Pierre, Louvain (Belgium). Lab. de Recherches de la Clinique Medicale

1979-09-01

A solid-phase radioimmunoassay was used to measure specific IgG antibodies to either Dermatophagoides pteronyssinus (DPT) or grass pollens. Radiolabelled protein A from Staphylococcus aureus (SpA) was used to determine the IgG antibodies attached to the microtubes. The binding of IgG from either normal or allergic sera to DPT-coated tubes was antigen specific and mediated by the Fab fragment of the immunoglobulin. IgG antibodies from non-allergic serum competed with IgE antibodies to DPT. IgE antibodies did not significantly interfere with the assay. Indeed heating a reaginic serum resulted in a striking reduction of the (/sup 125/I) anti- IgE binding to allergen-coated tubes without modifying the (/sup 125/I)-SpA binding. Furthermore, filtration of a reaginic serum through Sephacryl S-200 separated a peak of IgE antibodies. The solid phase method was more sensitive than a double-antibody technique employing the same DPT extract as labelled antigen. Non-allergic subjects had less IgG antibodies to DPT or grass pollens than allergic patients. In untreated patients, there was a good correlation between levels of IgG and IgE antibodies to grass pollens but not to DPT. Patients hyposensitized to house dust mite had on the average three times more specific IgG antibodies than untreated cases. (author).

Measurement of IgG antibodies to house dust mite and grass pollen by a solid-phase radioimmunoassay

International Nuclear Information System (INIS)

Delespesse, G.; Debisschop, M.J.; Flament, J.

1979-01-01

A solid-phase radioimmunoassay was used to measure specific IgG antibodies to either Dermatophagoides pteronyssinus (DPT) or grass pollens. Radiolabelled protein A from Staphylococcus aureus (SpA) was used to determine the IgG antibodies attached to the microtubes. The binding of IgG from either normal or allergic sera to DPT-coated tubes was antigen specific and mediated by the Fab fragment of the immunoglobulin. IgG antibodies from non-allergic serum competed with IgE antibodies to DPT. IgE antibodies did not significantly interfere with the assay. Indeed heating a reaginic serum resulted in a striking reduction of the ( 125 I) anti- IgE binding to allergen-coated tubes without modifying the ( 125 I)-SpA binding. Furthermore, filtration of a reaginic serum through Sephacryl S-200 separated a peak of IgE antibodies. The solid phase method was more sensitive than a double-antibody technique employing the same DPT extract as labelled antigen. Non-allergic subjects had less IgG antibodies to DPT or grass pollens than allergic patients. In untreated patients, there was a good correlation between levels of IgG and IgE antibodies to grass pollens but not to DPT. Patients hyposensitized to house dust mite had on the average three times more specific IgG antibodies than untreated cases. (author)

Nature of the bifunctional chelating agent used for radioimmunotherapy with yttrium-88 monoclonal antibodies: critical factors in determining in vivo survival and organ toxicity

Energy Technology Data Exchange (ETDEWEB)

Kozak, R.W.; Raubitschek, A.; Mirzadeh, S.; Brechbiel, M.W.; Junghaus, R.; Gansow, O.A.; Waldmann, T.A. (Center for Biologics Evaluation and Research, FDA, Bethesda, MD (USA))

1989-05-15

One factor that is critical to the potential effectiveness of radioimmunotherapy is the design of radiometal-chelated antibodies that will be stable in vivo. Stability in vivo depends on the condition that both the chelate linkage and radiolabeling procedures not alter antibody specificity and biodistribution. In addition, synthesis and selection of the chelating agent is critical for each radiometal in order to prevent inappropriate release of the radiometal in vivo. In the present study, we compare the in vivo stability of seven radioimmunoconjugates that use different polyaminocarboxylate chelating agents to complex yttrium-88 to the mouse anti-human interleukin-2 receptor monoclonal antibody, anti-Tac. Chelate linkage and radiolabeling procedures did not alter the immunospecificity of anti-Tac. In order to assess whether yttrium was inappropriately released from the chelate-coupled antibody in vivo, iodine-131-labeled and yttrium-88 chelate-coupled antibodies were simultaneously administered to the same animals to correlate the decline in yttrium and radioiodinated antibody activity. The four stable yttrium-88 chelate-coupled antibodies studied displayed similar iodine-131 and yttrium-88 activity, indicating minimal elution of yttrium-88 from the complex. In contrast, the unstable yttrium-88 chelate-coupled antibodies had serum yttrium-88 activities that declined much more rapidly than their iodine-131 activities, suggesting loss of the radiolabel yttrium-88 from the chelate. Furthermore, high rates of yttrium-88 elution correlated with deposition in bone. Four chelating agents emerged as promising immunotherapeutic reagents: isothiocyanate benzyl DTPA and its derivatives 1B3M, MX, and 1M3B.

Imaging of melanoma with 131I-labeled monoclonal antibodies

International Nuclear Information System (INIS)

Larson, S.M.; Brown, J.P.; Wright, P.W.; Carrasquillo, J.A.; Hellstroem, I.; Hellstroem, K.E.

1983-01-01

Mouse monoclonal antibodies and Fab fragments specific for p97, a melanoma-associated antigen, were used to image metastatic human melanoma. Preclinical studies in athymic mice showed antigen-specific uptake in melanoma xenografts, and toxicity tests in rabbits gave no evidence for tissue damage after injection of up to 100 times the amount of antibody used in humans. Six patients received 1 mg labeled antibody, and one patient received 1 mg of labeled Fab. No. toxic side effects were observed. All of the six patients had positive scans, visualizing 22 of 25 (88%) of lesions larger than 1.5 cm. In tumors from two patients, greater uptake of p97-specific, versus control IgG and Fab, respectively, was documented by biopsy. Antibodies to mouse immunoglobulin appeared in three patients receiving 1 mg or more of radiolabeled mouse antibody

Synthesis, radiolabeling and quality control of {sup 111}In-DOTA-bevacizumab for radioimmunoscintigraphy of VEGF receptors

Energy Technology Data Exchange (ETDEWEB)

Khorami-Moghadam, A.; Jalilian, A.R.; Yavari, K.; Alirezapour, B.; Mazidi, M.; Mirzaii, M. [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of)

2013-11-01

In this study, bevacizumab was successively labeled with {sup 111}In-InCl{sub 3} after conjugation with DOTA-NHS-ester followed by molecular filtration and determination of the average number ofDOTAconjugated per mAb (6:1) by spectrophotometric method. Radiochemical purity (> 97%, measured by ITLC and HPLC), integrity of protein after radiolabeling (gel electrophoresis) and stability of {sup 111}In-DOTA-Bevacizumab (in final formulation, human serum, liver/kidney homogenates) were determined in 24-72 h as well as biodistribution studies in wild-type rats and human colon cancer (SW-480) bearing mice. The accumulation of the radiolabeled antibody was consistent with the former reported Bevacizumab conjugates. Significant tumor uptake (8%) was observed at 72 h p.i. Tumor/muscle uptake ratios were 2.6 (24 h), 9.74 (48 h) and 25 (72 h). {sup 111}In-DOTA-Bevacizumab was prepared as a SPECT molecular imaging agent for diagnosis and follow-up of vascular endothelial growth factor A (VEGF-A) expression in oncology. (orig.)

Radiolabeling of rituximab with {sup 188}Re and {sup 99m}Tc using the tricarbonyl technology

Energy Technology Data Exchange (ETDEWEB)

Dias, Carla Roberta [Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Jeger, Simone [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Osso, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares, Av. Professor Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Mueller, Cristina; De Pasquale, Christine; Hohn, Alexander; Waibel, Robert [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Schibli, Roger, E-mail: roger.schibli@psi.c [Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen-PSI (Switzerland); Department of Chemistry and Applied Biosciences of the ETH, 8093 Zurich (Switzerland)

2011-01-15

Introduction: The most successful clinical studies of immunotherapy in patients with non-Hodgkin's lymphoma (NHL) use the antibody rituximab (RTX) targeting CD20{sup +} B-cell tumors. Rituximab radiolabeled with {beta}{sup -} emitters could potentiate the therapeutic efficacy of the antibody by virtue of the particle radiation. Here, we report on a direct radiolabeling approach of rituximab with the {sup 99m}Tc- and {sup 188}Re-tricarbonyl core (IsoLink technology). Methods: The native format of the antibody (RTX{sub wt}) as well as a reduced form (RTX{sub red}) was labeled with {sup 99m}Tc/{sup 188}Re(CO){sub 3}. The partial reduction of the disulfide bonds to produce free sulfhydryl groups (-SH) was achieved with 2-mercaptoethanol. Radiolabeling efficiency, in vitro human plasma stability as well as transchelation toward cysteine and histidine was investigated. The immunoreactivity and binding affinity were determined on Ramos and/or Raji cells expressing CD20. Biodistribution was performed in mice bearing subcutaneous Ramos lymphoma xenografts. Results: The radiolabeling efficiency and kinetics of RTX{sub red} were superior to that of RTX{sub wt} ({sup 99m}Tc: 98% after 3 h for RTX{sub red} vs. 70% after 24 h for RTX{sub wt}). {sup 99m}Tc(CO){sub 3}-RTX{sub red} was used without purification for in vitro and in vivo studies whereas {sup 188}Re(CO){sub 3}-RTX{sub red} was purified to eliminate free {sup 188}Re-precursor. Both radioimmunoconjugates were stable in human plasma for 24 h at 37{sup o}C. In contrast, displacement experiments with excess cysteine/histidine showed significant transchelation in the case of {sup 99m}Tc(CO){sub 3}-RTX{sub red} but not with pre-purified {sup 188}Re(CO){sub 3}-RTX{sub red}. Both conjugates revealed high binding affinity to the CD20 antigen (K{sub d}=5-6 nM). Tumor uptake of {sup 188}Re(CO){sub 3}-RTX{sub red} was 2.5 %ID/g and 0.8 %ID/g for {sup 99m}Tc(CO){sub 3}-RTX{sub red} 48 h after injection. The values for other

Secondary antibodies as tools to improve tumor to non tumor ratio at radioimmunolocalisation and radioimmunotherapy

International Nuclear Information System (INIS)

Ullen, A.; Riklund Aalstroem, K.; Hietala, S.O.; Nilsson, B.; Aerlestig, L.; Stigbrand, T.

1996-01-01

One way of selectively improving the efficiency of radioimmunolocalization and radioimmunotherapy is to eliminate redundant, circulating, non-targeting radiolabeled antibodies after saturation of the target sites. Secondary antibodies of different types have been proposed as clearing agents for such purposes. The conceptually different approaches of the 'secondary antibody' strategy including its advantages and limitations are discussed. This mini-review also presents a model describing the kinetics of the components (the antigen, the primary and secondary antibodies) and approaches required to improve the efficacy of both radioimmunolocalization and radioimmunotherapy. (orig.)

Interferon-induced changes in pharmacokinetics and tumor uptake of 111In-labeled antimelanoma antibody 96.5 in melanoma patients

International Nuclear Information System (INIS)

Rosenblum, M.G.; Lamki, L.M.; Murray, J.L.; Carlo, D.J.; Gutterman, J.U.

1988-01-01

The type I interferons [both partially purified human leukocyte interferon (HuIFN-alpha) and recombinant alpha interferon] and the type II interferons have been shown to increase the expression of tumor-associated antigens in vitro. To determine whether HuIFN-alpha could increase tumor acquisition of the antimelanoma antibody 96.5 in vivo, five patients with metastatic malignant melanoma were treated with HuIFN-alpha at a dose of 3 X 10(6) units daily by im administration. Twenty-four hours after the first dose of HuIFN-alpha, 1 mg of antibody 96.5 labeled with 5 mCi of 111 In was coadministered with 19 mg of unlabeled 96.5. Five patients matched for metastatic site and lesion size who had not received HuIFN-alpha were also given a dose of 5 mCi of radiolabeled 96.5 at the same total antibody dose (20 mg). In patients treated with HuIFN-alpha, there was a statistically significant increase in the plasma half-life of the 111 In label (39.7 +/- 3.3 hr) compared to the untreated control group (29.8 +/- 3.2 hr). In addition, there was an increase in the apparent volume of distribution of the antibody in the HuIFN-alpha group (5.56 +/- 0.67 L) compared to controls (3.15 +/- 0.5 L) suggesting both an increased immediate extravascular distribution of radiolabeled antibody and a decrease in the subsequent rate of clearance of antibody from plasma. These two phenomena result in a 28% decrease in the area under the concentration curve in the HuIFN-alpha-treated group compared to controls. Computer analysis of whole-body scans from patients showed a threefold increase in radiolabeled antibody distributed to tumor relative to blood pool but no change in organ:blood ratios for liver, spleen, bone, or kidney compared to controls

Clearance of 131I-labeled murine monoclonal antibody from patients' blood by intravenous human anti-murine immunoglobulin antibody

International Nuclear Information System (INIS)

Stewart, J.S.; Sivolapenko, G.B.; Hird, V.; Davies, K.A.; Walport, M.; Ritter, M.A.; Epenetos, A.A.

1990-01-01

Five patients treated with intraperitoneal 131I-labeled mouse monoclonal antibody for ovarian cancer also received i.v. exogenous polyclonal human anti-murine immunoglobulin antibody. The pharmacokinetics of 131I-labeled monoclonal antibody in these patients were compared with those of 28 other patients receiving i.p.-radiolabeled monoclonal antibody for the first time without exogenous human anti-murine immunoglobulin, and who had no preexisting endogenous human anti-murine immunoglobulin antibody. Patients receiving i.v. human anti-murine immunoglobulin antibody demonstrated a rapid clearance of 131I-labeled monoclonal antibody from their circulation. The (mean) maximum 131I blood content was 11.4% of the injected activity in patients receiving human anti-murine immunoglobulin antibody compared to 23.3% in patients not given human anti-murine immunoglobulin antibody. Intravenous human anti-murine immunoglobulin antibody decreased the radiation dose to bone marrow (from 131I-labeled monoclonal antibody in the vascular compartment) 4-fold. Following the injection of human anti-murine immunoglobulin antibody, 131I-monoclonal/human anti-murine immunoglobulin antibody immune complexes were rapidly transported to the liver. Antibody dehalogenation in the liver was rapid, with 87% of the injected 131I excreted in 5 days. Despite the efficient hepatic uptake of immune complexes, dehalogenation of monoclonal antibody was so rapid that the radiation dose to liver parenchyma from circulating 131I was decreased 4-fold rather than increased. All patients developed endogenous human anti-murine immunoglobulin antibody 2 to 3 weeks after treatment

Radiolabeling of anti-human prostatic specific membrane antigen antibody with 99Tcm and its biodistribution in nude mice bearing human prostate cancer

International Nuclear Information System (INIS)

Tu Shaohua; Shen Jiangfan; Tao Rong; Ji Xiaowen; Wang Yancheng

2012-01-01

Objective: To study the binding affinity of 99 Tc m labeled anti-human prostatic specific membrane antigen (PSMA) monoclonal antibody (McAb) J591 to prostate cancer cells and the biodistribution of 99 Tc m -J591 in nude mice bearing human prostate cancer. Methods: The McAb J591 was labeled with vTcm by improved Schwarz method and the labeled McAb was purified by Sephadex G-50. The binding affinity of J591 with prostate cancer cells was measured by Flow Cytometry. The nude mice bearing PSMA-positive C4-2 prostate carcinoma xenografts were served as experiment groups, mice with PSMA-negative pc3 tumors served as controls. The biodistribution of 99 Tc m -J591 were carried out in both model nude mice. Results: The radiolabeling efficiency of 99 Tc m -J591 was 78.9±6.2%, and radiochemical purity was more than 90% after purification. The 99 Tc m -J591 showed a good combination with PSMA-positive C4-2 cells and no combination with PSMA-negative PC3 cells in vitro. The biodistribution results showed that 99 Tcm-J591 was accumulated in tumor tissue during the 2-24 hours after injection in experiment groups, and no significant uptake in control group. The uptake of 99 Tcm-J591 in tumor tissue reached a maximum 15.91±5.16 % ID/g in experimental group at 12h post-injection. There was a significant difference compared with controls (P 0.05). Conclusion: The monoclonal antibody J591 exhibits an excellent immuno-reactivity and tumor targeting property, and it may be used in diagnosis and target therapy of prostate cancer. (authors)

Monoclonal antibodies for treating cancer

International Nuclear Information System (INIS)

Dillman, R.O.

1989-01-01

The purpose of this study is to assess the current status of in-vivo use of monoclonal antibodies for treating cancer. Publications appearing between 1980 and 1988 were identified by computer searches using MEDLINE and CANCERLIT, by reviewing the table of contents of recently published journals, and by searching bibliographies of identified books and articles. More than 700 articles, including peer-reviewed articles and book chapters, were identified and selected for analysis. The literature was reviewed and 235 articles were selected as relevant and representative of the current issues and future applications for in-vivo monoclonal antibodies for cancer therapy and of the toxicity and efficacy which has been associated with clinical trials. Approaches include using antibody alone (interacting with complement or effector cells or binding directly with certain cell receptors) and immunoconjugates (antibody coupled to radioisotopes, drugs, toxins, or other biologicals). Most experience has been with murine antibodies. Trials of antibody alone and radiolabeled antibodies have confirmed the feasibility of this approach and the in-vivo trafficking of antibodies to tumor cells. However, tumor cell heterogeneity, lack of cytotoxicity, and the development of human antimouse antibodies have limited clinical efficacy. Although the immunoconjugates are very promising, heterogeneity and the antimouse immune response have hampered this approach as has the additional challenge of chemically or genetically coupling antibody to cytotoxic agents. As a therapeutic modality, monoclonal antibodies are still promising but their general use will be delayed for several years. New approaches using human antibodies and reducing the human antiglobulin response should facilitate treatment. 235 references

In vivo localization of radiolabeled monoclonal antibody to carcinoembryonic antigen (CEA) in a CEA-producing tumor

International Nuclear Information System (INIS)

Kamei, Tetsuya; Seto, Hikaru; Taki, Kuniyasu; Soya, Toshio; Kakishita, Masao; Maeda, Masatoshi; Honda, Takashi; Koshimura, Saburou.

1987-01-01

To compare accumulation of the 125 I-labeled antibodies(anti-carcinoembryonic antigen(CEA) monoclonal antibody and polyclonal antibody) to a CEA-producing tumor (SC-2-JCK), an in vivo localization study was performed in nude mice. The tumor-to-blood ratio at 120 hours after injection rose to 4.6 for the monoclonal antibody, but remained at 1.3 for the polyclonal antibody. However, no differences were noted between the antibodies up to 72 hours after injection. In autoradiograms, selective accumulation of the tracer was noted in the tumor for both antibodies. However, no superiority or inferiority of imaging for either of the antibodies could be definitely determined. (author)

A highly sensitive radioimmunoassay technique for subtyping the antibody to hepatitis B surface antigen

International Nuclear Information System (INIS)

Fang, C.T.; Nath, N.; Berberian, H.; Dodd, R.Y.

1978-01-01

A highly sensitive technique for determining the subtype specificity of antibody to hepatitis B surface antigen (anti-HBs) is described. Immunoadsorbent consisting of controlled pore glass coated with subtype specific HBsAg was used to remove homologous antibody from the test samples before testing them for residual antibody by a commercially available radioimmunoassay (RIA). A total of 73 anti-HBs-positive samples from asymptomatic blood donors were tested. In nearly 80% of these samples the subtype reactivity could be determined by this technique. Only 67% could be typed by conventional liquid phase absorption RIA and 22% by passive hemagglutination inhibition techniques. Among the samples with low anti-HBs titer, ad and ay subtypes were found with equal frequency; however, with the increase in anti-HBs titer, considerably higher proportion of ad specificity was detected. (Auth.)

Preparation and biodistribution of radiolabeled fullerene C60 nanocrystals

International Nuclear Information System (INIS)

Nikolic, Nadezda; Vranjes-Duric, Sanja; Jankovic, Drina; Dokic, Divna; Mirkovic, Marija; Bibic, Natasa; Trajkovic, Vladimir

2009-01-01

The present study describes for the first time a procedure for the radiolabeling of fullerene (C 60 ) nanocrystals (nanoC 60 ) with Na 125 I, as well as the biodistribution of radiolabeled nanoC 60 ( 125 I-nanoC 60 ). The solvent exchange method with tetrahydrofuran was used to make colloidal water suspensions of radiolabeled nanoC 60 particles. The radiolabeling procedure with the addition of Na 125 I to tetrahydrofuran during dissolution of C 60 gave a higher radiochemical yield of radiolabeled nanoC 60 particles in comparison to the second option, in which Na 125 I was added after C 60 was dissolved. Using photon correlation spectroscopy and transmission electron microscopy, 125 I-nanoC 60 particles were found to have a crystalline structure and a mean diameter of 200-250 nm. The 125 I-nanoC 60 had a particularly high affinity for human serum albumin, displaying 95% binding efficiency after 1 h. Biodistribution studies of 125 I-nanoC 60 in rats indicated significant differences in tissue accumulation of 125 I-nanoC 60 and the radioactive tracer Na 125 I. The higher accumulation of radiolabeled nanoC 60 was observed in liver and spleen, while accumulation in thyroid, stomach, lungs and intestines was significantly lower in comparison to Na 125 I. In addition to being useful for testing the biological distribution of nanoC 60 , the described radiolabeling procedure might have possible applications in cancer radiotherapy.

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Britton, W.J.; Hellqvist, L.; Basten, A.; Raison, R.L.

1985-12-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bands of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae.

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

International Nuclear Information System (INIS)

Britton, W.J.; Hellqvist, L.; Basten, A.; Raison, R.L.

1985-01-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bands of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae

Mouse-specific antibody responses to a monoclonal antibody during repeated immunoscintigraphy investigations: Comparison of antibody titres and imaging studies in a rat model

International Nuclear Information System (INIS)

Pimm, M.V.; Gribben, S.J.; Markham, A.J.; Perkins, A.C.

1990-01-01

As a model for human mouse-specific antibody responses in patients undergoing immunoscintigraphy, we have investigated in rats the production of mouse-specific antibodies (MA) to the mouse monoclonal antibody 791T/36. At intervals of between 5 and 16 weeks the rats were given repeated cycles of intravenous (IV) injections of antibody with or without a simultaneous intradermal (ID) injection. The IV dose was 60 μg/kg, a dose similar to that used in many clinical immunoscintigraphy studies. The ID injection was 2 μg, which mimicks the skin test dose often given in clinical imaging protocols. The study was carried out with both 131 I-labelled antibody and with antibody labelled with 111 In by DTPA chelation. MA was measured with a passive haemagglutination assay using sheep red blood cells coated with the monoclonal antibody. Of rats given ID injections of unlabelled antibody at the same time as the IV imaging doses, 9/20 produced MA during 4 cycles of injections. In contrast, only 2/16 rats given only the IV dose produced MA. Both 131 I- and 111 In-labelled antibody appeared equally immunogenic with 5/18 and 6/18 overall responders, respectively. The production of MA was associated with a significant perturbation in the biodistribution of the IV dose of labelled antibody as seen by gamma-camera imaging of the rats given 111 In-labelled antibody. There was clearance of immune complexes to the liver, this organ accumulating up to 90% of the whole body count rate of radiolabel. MA titres of between 1/100 and 1/78000 caused equal perturbation of biodistribution, although below 1/100 the effect was more variable. (orig.)

Designer genes. Recombinant antibody fragments for biological imaging

Energy Technology Data Exchange (ETDEWEB)

Wu, A.M.; Yazaki, P.J. [Beckman Research Institute of the City of Hope, Duarte, CA (United States). Dept. of Molecular Biology

2000-09-01

Monoclonal antibodies (MAbs), with high specificity and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C{sub H}3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering

Designer genes. Recombinant antibody fragments for biological imaging

International Nuclear Information System (INIS)

Wu, A.M.; Yazaki, P.J.

2000-01-01

Monoclonal antibodies (MAbs), with high specificy and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C H 3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering and

Indirect Fluorescent Antibody Technique based Prevalence of Surra in Equines

Directory of Open Access Journals (Sweden)

Ahsan Nadeem, Asim Aslam*, Zafar Iqbal Chaudhary, Kamran Ashraf1, Khalid Saeed1, Nisar Ahmad1, Ishtiaq Ahmed and Habib ur Rehman2

2011-04-01

Full Text Available This project was carried out to find the prevalence of trypanosomiasis in equine in District Gujranwala by using indirect fluorescent antibody technique and thin smear method. Blood samples were collected from a total of 200 horses and donkeys of different ages and either sex. Duplicate thin blood smears were prepared from each sample and remaining blood samples were centrifuged to separate the serum. Smears from each animal were processed for giemsa staining and indirect fluorescent antibody test (IFAT. Giemsa stained smears revealed Trypanosome infection in 4/200 (2.0% samples and IFAT in 12/200 (6.0% animals.

Imaging of primary and metastatic colorectal carcinoma with monoclonal antibody 791T/36 and the therapeutic potential of antibody-drug conjugates

International Nuclear Information System (INIS)

Pimm, M.V.; Armitage, N.C.; Ballantyne, K.; Baldwin, R.W.; Perkins, A.C.; Durrant, L.G.; Garnett, M.C.; Hardcastle, J.D.

1987-01-01

Monoclonal antibody 791T/36, prepared against a tumor-associated 72,000 dalton glycoprotein, reacted with cells from primary and metastatic colorectal carcinomas. I-131 or In-111-labelled antibody localized in xenografts of colorectal carcinomas established from in vitro clonogenic populations. Clinically, with I-131-labelled antibody, 8/11 colonic tumors imaged positively. Imaging was negative in four patients with benign colon disease. 5/11 rectal tumors were positively imaged, but excreted I-131 in the bladder obscured tumors in several studies. In-111-labelled antibody gave superior images and positively imaged primary and metastatic sites in 13/14 patients. Prospectively in the detection of recurrent disease, I-131 or In-111-antibody detected 29/33 separate sites in 24 patients. Seven negative patients remain disease free. There were 3 false positives; overall sensitivity was 88%, with 70% specificity. Specific localization of radiolabel was confirmed immunochemically and by counting radioactivity in resected specimens. Antibody conjugates with methotrexate, vindesine and daunomycin retained drug activity and antibody function, including xenograft localization and conjugates were therapeutically effective against xenografts. 791T/36 antibody has potential for immunodetection of primary and recurrent colorectal carcinoma and for targeting of therapeutic agents

Autodecomposition of radiolabeled human growth hormone

International Nuclear Information System (INIS)

Baumann, G.; Amburn, K.

1986-01-01

Human growth hormone (hGH) was radiolabeled with 125 I, using a gentle lactoperoxidase technique. The stability and decomposition products of this tracer were studied by frequent periodic analysis by Sephadex G-100 chromatography on a long column. Monomeric 125 I-hGH showed an exponential decline, with a half-life of 61 days. The main radioactive degradation product was iodide, which appeared with a fractional appearance rate of 0.01136 per day. Secondary degradation products were a series of radioactive oligomers of hGH, which appeared with an overall fractional rate of 0.00525 per day. The kinetic data obtained should provide guidelines for the shelf-life and repurification schedule of radioiodinated polypeptides

Development of Novel Radio-labeled Materials using Research Reactor

International Nuclear Information System (INIS)

Choi, Sun Ju; Hong, Y. D.; Choi, K. H.

2010-04-01

In this project, we aim to develop the novel radiomaterials using reactor-produced radioisotope for the targeted therapy of cancer. At initial stage, we have examined the effect of beta particle-emission radionuclides on the proliferation of various types of tumor cells and found that beta particle emission radionuclides significantly inhibited the proliferation of tumor cells. We have synthesized new bifunctional chelating agents (BFCAs) for bio-conjugation with bio-active molecules, such as peptide and antibody, and radioabeling with radionuclide. For targeted radiotherapy, we have prepared target materials and radiolabeled with various radionuclides using BFCAs and obtained candidate materials for the treatment of melanoma. We have next treated melanoma-induced animals with candidate radiopharmaceuticals. The tumor growth was significantly reduced by treatment with candidates, and survival rate of the animals was prolonged, suggesting that candidate radiopharmaceuticals are promising agents for the treatment of melanoma

Preparation of radiolabeled bioactive asbestos fibers

Energy Technology Data Exchange (ETDEWEB)

Tewson, T J; Francsechini, M P; Scheule, R K; Holian, A [Texas Univ., Houston, TX (USA). Health Science Center

1991-01-01

We have developed an efficient procedure to radiolabel asbestos fibers while retaining the bioactivity of the fibers. The fibers are labeled with {sup 68}Ge. The {sup 68}Ge decays into {sup 68}Ga, which then can be detected by its characteristic positron emission. Both chrysotile and crocidolite asbestos, a serpentine and an amphibole, respectively, were radiolabeled successfully. Mild reaction conditions and short reaction times were found under which {similar to}90% of the added {sup 68}Ge and {sup 68}Ga bound to the fibers. The radiolabel was retained even after washing the fibers extensively with physiologic buffers. The effects of the labeling on the bioactivity of the fibers were evaluated in an in vitro assay using guinea pig alveolar macrophages as a target cell. Labeled chrysotile fibers were found to retain >95% of their ability to stimulate these cells. The labeling procedure described in this study should be useful in preparing labeled fibers to investigate both in vitro and in vivo phenomena. (author).

Microfluidic radiolabeling of biomolecules with PET radiometals

International Nuclear Information System (INIS)

Zeng Dexing; Desai, Amit V.; Ranganathan, David; Wheeler, Tobias D.; Kenis, Paul J.A.; Reichert, David E.

2013-01-01

Introduction: A robust, versatile and compact microreactor has been designed, fabricated and tested for the labeling of bifunctional chelate conjugated biomolecules (BFC-BM) with PET radiometals. Methods: The developed microreactor was used to radiolabel a chelate, either 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) that had been conjugated to cyclo(Arg-Gly-Asp-DPhe-Lys) peptide, with both 64 Cu and 68 Ga respectively. The microreactor radiolabeling conditions were optimized by varying temperature, concentration and residence time. Results: Direct comparisons between the microreactor approach and conventional methods showed improved labeling yields and increased reproducibility with the microreactor under identical labeling conditions, due to enhanced mass and heat transfer at the microscale. More importantly, over 90% radiolabeling yields (incorporation of radiometal) were achieved with a 1:1 stoichiometry of bifunctional chelate biomolecule conjugate (BFC-BM) to radiometal in the microreactor, which potentially obviates extensive chromatographic purification that is typically required to remove the large excess of unlabeled biomolecule in radioligands prepared using conventional methods. Moreover, higher yields for radiolabeling of DOTA-functionalized BSA protein (Bovine Serum Albumin) were observed with 64 Cu/ 68 Ga using the microreactor, which demonstrates the ability to label both small and large molecules. Conclusions: A robust, reliable, compact microreactor capable of chelating radiometals with common chelates has been developed and validated. Based on our radiolabeling results, the reported microfluidic approach overall outperforms conventional radiosynthetic methods, and is a promising technology for the radiometal labeling of commonly utilized BFC-BM in aqueous solutions.

Experimental radioimmunotherapy of a xenografted human glioma using [sup 131]I-labeled monoclonal antibody to epidermal growth factor receptor

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Hiroshi; Nakazawa, Shozo [Nippon Medical School, Tokyo (Japan); Herlyn, D

1993-09-01

[sup 131]I-labeled F (ab')[sub 2] fragments of murine monoclonal antibodies (MAb) 425 specific to the epidermal growth factor receptor expressed on human gliomas were used in experimental human malignant glioma immunotherapy. Two injections of 150 [mu]Ci [sup 131]I-labeled 425 F(ab')[sub 2] achieved growth inhibition of U-87MG human malignant glioma xenografts in nude mice. This radiolabeled specific MAb F(ab')[sub 2] was significantly superior to radiolabeled fragments of an anti-hepatitis virus control MAb A5C3 in influencing tumor growth. However, similar treatment of established human malignant glioma xenografts did not inhibit progressive tumor growth significantly. No clear tumor inhibition was produced by unlabeled MAb 425F(ab')[sub 2]. These studies suggest that [sup 131]I-labeled MAbs have a significant antitumor effect where unmodified antibody is ineffective. Multiple doses of antibody may achieve an increase in labeled MAb concentration in tumors. (author).

System for exposing animals to radiolabeled diesel exhaust

International Nuclear Information System (INIS)

Lopez, J.A.; Wolf, I.; Wolff, R.K.; Sun, J.D.; Mokler, B.V.

1981-01-01

One approach to determining the deposition and fate of inhaled diesel particles is the conduct of inhalation exposure studies with radiolabeled diesel fuel. A system was designed, constructed and tested for the simultaneous exposure of animals to radiolabeled diesel exhaust and collection of large quantities of radiolabeled diesel exhaust particles from a single cylinder diesel engine. The system performance was characterized and evaluated over a range of operating conditions: 0 to 1800 watts of engine load, 1000 to 2500 rpm and dilution air rates of 1:2 and 1:10. The exposure system met required design and operating criteria for safety, portability, space and flexibility

Technetium-99m direct radiolabeling of monoclonal antibody ior egf/r3

Energy Technology Data Exchange (ETDEWEB)

Morales, Alejo A. Morales; Crespo, Francisco Zayas; Gandolff, Gilda Nunez; Escobar, Normando Iznaga; Perez, Niuvis Perez; Hernandez, Juan C. Izquierdo

1998-01-01

Monoclonal antibodies (MAbs) are being widely used for imaging studies, coupled mainly with {sup 99m}Tc. The antibody ior egf/r3 is a MAb against human epidermal growth factor receptor (hEGF-r), and we have developed a method for optimum labeling of this MAb with {sup 99m}Tc. The reduction was performed with 2-mercaptoethanol (2-ME) at a molar ratio of 2000:1 (2-ME:MAb) and methylene diphosphonate as transchelant. The integrity of reduced MAb was checked by mean of native polyacrylamide gel electrophoresis (PAGE) and gel filtration chromatography on Superose 12 (purity >99%). Radio colloids remained lower than 2%, and the labeling efficiency was 98.5%. The number of sulfhydryl groups generated was quantified using Ellman's reagent and was found to be 6.65 {+-} 0.69 per antibody molecule. In vitro stability studies in several challenging conditions (DTPA, human serum albumin and human serum) were performed, and no significant loss in binding percentage was seen. Radio receptor assay was used to test immunoreactivity of the reduced MAb. Both labeled and unlabeled MAbs were able to compete for binding to the hEGF-r with radioiodinated EGF. Biodistribution studies in BALB/c mice are reported.

Technetium-99m direct radiolabeling of monoclonal antibody ior egf/r3

International Nuclear Information System (INIS)

Morales, Alejo A. Morales; Crespo, Francisco Zayas; Gandolff, Gilda Nunez; Escobar, Normando Iznaga; Perez, Niuvis Perez; Hernandez, Juan C. Izquierdo

1998-01-01

Monoclonal antibodies (MAbs) are being widely used for imaging studies, coupled mainly with 99m Tc. The antibody ior egf/r3 is a MAb against human epidermal growth factor receptor (hEGF-r), and we have developed a method for optimum labeling of this MAb with 99m Tc. The reduction was performed with 2-mercaptoethanol (2-ME) at a molar ratio of 2000:1 (2-ME:MAb) and methylene diphosphonate as transchelant. The integrity of reduced MAb was checked by mean of native polyacrylamide gel electrophoresis (PAGE) and gel filtration chromatography on Superose 12 (purity >99%). Radio colloids remained lower than 2%, and the labeling efficiency was 98.5%. The number of sulfhydryl groups generated was quantified using Ellman's reagent and was found to be 6.65 ± 0.69 per antibody molecule. In vitro stability studies in several challenging conditions (DTPA, human serum albumin and human serum) were performed, and no significant loss in binding percentage was seen. Radio receptor assay was used to test immunoreactivity of the reduced MAb. Both labeled and unlabeled MAbs were able to compete for binding to the hEGF-r with radioiodinated EGF. Biodistribution studies in BALB/c mice are reported

Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

Science.gov (United States)

Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

2016-04-01

Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

Comparison of bifunctional chelates for {sup 64}Cu antibody imaging

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Cara L.; Crisp, Sarah; Bensimon, Corinne [MDS Nordion, Vancouver, BC (Canada); Yapp, Donald T.T.; Ng, Sylvia S.W. [British Columbia Cancer Agency Research Centre, Vancouver, BC (Canada); University of British Columba, The Faculty of Pharmaceutical Sciences, Vancouver, BC (Canada); Sutherland, Brent W. [British Columbia Cancer Agency Research Centre, Vancouver, BC (Canada); Gleave, Martin [Prostate Centre at Vancouver General Hospital, Vancouver, BC (Canada); Jurek, Paul; Kiefer, Garry E. [Macrocyclics Inc., Dallas, TX (United States)

2010-11-15

Improved bifunctional chelates (BFCs) are needed to facilitate efficient {sup 64}Cu radiolabeling of monoclonal antibodies (mAbs) under mild conditions and to yield stable, target-specific agents. The utility of two novel BFCs, 1-Oxa-4,7,10-triazacyclododecane-5-S-(4-isothiocyanatobenzyl)-4,7,10-triacetic acid (p-SCN-Bn-Oxo-DO3A) and 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-4-S-(4-isothiocyanatobenzyl)-3,6,9-triacetic acid (p-SCN-Bn-PCTA), for mAb imaging with {sup 64}Cu were compared to the commonly used S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (p-SCN-Bn-DOTA). The BFCs were conjugated to trastuzumab, which targets the HER2/neu receptor. {sup 64}Cu radiolabeling of the conjugates was optimized. Receptor binding was analyzed using flow cytometry and radioassays. Finally, PET imaging and biodistribution studies were done in mice bearing either HER2/neu-positive or HER2/neu-negative tumors. {sup 64}Cu-Oxo-DO3A- and PCTA-trastuzumab were prepared at room temperature in >95% radiochemical yield (RCY) in <30 min, compared to only 88% RCY after 2 h for the preparation of {sup 64}Cu-DOTA-trastuzumab under the same conditions. Cell studies confirmed that the immunoreactivity of the mAb was retained for each of the bioconjugates. In vivo studies showed that {sup 64}Cu-Oxo-DO3A- and PCTA-trastuzumab had higher uptake than the {sup 64}Cu-DOTA-trastuzumab at 24 h in HER2/neu-positive tumors, resulting in higher tumor to background ratios and better tumor images. By 40 h all three of the {sup 64}Cu-BFC-trastuzumab conjugates allowed for clear visualization of the HER2/neu-positive tumors but not the negative control tumor. The antibody conjugates of PCTA and Oxo-DO3A were shown to have superior {sup 64}Cu radiolabeling efficiency and stability compared to the analogous DOTA conjugate. In addition, {sup 64}Cu-PCTA and Oxo-DO3A antibody conjugates may facilitate earlier imaging with greater target to background ratios than

Radioimmunoimaging of experimental thrombi in dogs using technetium-99m-labeled monoclonal antibody fragments reactive with human platelets

International Nuclear Information System (INIS)

Som, P.; Oster, Z.H.; Zamora, P.O.; Yamamoto, K.; Sacker, D.F.; Brill, A.B.; Newell, K.D.; Rhodes, B.A.

1986-01-01

Monoclonal antibody 50H.19, which reacts with human platelets, was converted to fragments, pretinned, and made into kits for subsequent radiolabeling with /sup 99m/Tc. The antibody, which cross-reacts with dog platelets, was used to evaluate in vitro binding to blood clots and in vivo in experimental thrombi in dogs. After radiolabeling, 97.4 +/- 6.4% of the /sup 99m/Tc was antibody-associated. The preparations retained immunoreactivity, as determined by: binding studies using whole blood and determining the ratio of cell-to-plasma radioactivity (ratios of 57.6-61.2) and binding of the antibody to clots (clot/serum ratios were 57.2-74.6%). Approximately 50% of the radioactivity was cleared from the blood in 3-6 min and 18-24% was excreted in urine within 3 hr. Experimental thrombi in dogs could be visualized consistently within 2-3 hr postinjection in peripheral veins and arteries, pulmonary arteries, and the right ventricle. In addition, damage to blood vessel intima without visible thrombi could also be detected. This method has the following advantages: short and simple pre-imaging preparation, and rapid visualization of thrombi with no need for blood-pool subtraction or delayed imaging

Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy

Directory of Open Access Journals (Sweden)

Wiebke Sihver

2014-03-01

Full Text Available The epidermal growth factor receptor (EGFR has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.

Microfluidic radiolabeling of biomolecules with PET radiometals.

Science.gov (United States)

Zeng, Dexing; Desai, Amit V; Ranganathan, David; Wheeler, Tobias D; Kenis, Paul J A; Reichert, David E

2013-01-01

A robust, versatile and compact microreactor has been designed, fabricated and tested for the labeling of bifunctional chelate conjugated biomolecules (BFC-BM) with PET radiometals. The developed microreactor was used to radiolabel a chelate, either 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) that had been conjugated to cyclo(Arg-Gly-Asp-DPhe-Lys) peptide, with both ⁶⁴Cu and ⁶⁸Ga respectively. The microreactor radiolabeling conditions were optimized by varying temperature, concentration and residence time. Direct comparisons between the microreactor approach and conventional methods showed improved labeling yields and increased reproducibility with the microreactor under identical labeling conditions, due to enhanced mass and heat transfer at the microscale. More importantly, over 90% radiolabeling yields (incorporation of radiometal) were achieved with a 1:1 stoichiometry of bifunctional chelate biomolecule conjugate (BFC-BM) to radiometal in the microreactor, which potentially obviates extensive chromatographic purification that is typically required to remove the large excess of unlabeled biomolecule in radioligands prepared using conventional methods. Moreover, higher yields for radiolabeling of DOTA-functionalized BSA protein (Bovine Serum Albumin) were observed with ⁶⁴Cu/⁶⁸Ga using the microreactor, which demonstrates the ability to label both small and large molecules. A robust, reliable, compact microreactor capable of chelating radiometals with common chelates has been developed and validated. Based on our radiolabeling results, the reported microfluidic approach overall outperforms conventional radiosynthetic methods, and is a promising technology for the radiometal labeling of commonly utilized BFC-BM in aqueous solutions. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of radiolabeled mannose-dextran conjugates for sentinel lymph node detection

International Nuclear Information System (INIS)

Fernandez Nunez, Eutimio Gustavo

2011-01-01

Early diagnosis of tumors and metastasis is the current cornerstone in public health policies directed towards the fights against cancer. In breast cancer and melanoma, the sentinel lymph node biopsy has been widely used for diagnoses of metastasis. The minor impact in patient of this technique compared with total nodes dissection and the accurate definition of therapeutic strategies have powered its spreading. The aim of this work was the development of radiolabeled dextran-mannose conjugates for diagnosis using the stable technetium core [ 99m Tc(CO)3] + . Cysteine, a trident ligand, was attached to the conjugates backbone, as a chelate for 99m Tc labeling. Radiolabeling conditions established for all products considered in this study showed high radiochemical purities (> 90%) and specific activities (>59,9 MBq/nmol) as well and high stability obtained through in vitro tests. The lymphatic node uptake increased significantly (4-folds) when mannose units were added to the conjugates compared with those without this monosaccharide. The radiolabeled cysteine-mannose-dextran conjugate with 30 kDa ( 99m Tc - DCM2) showed the best performance at different injected activities among the studied tracers. Concentrations of this radio complex higher than 1 M demonstrated an improvement of lymph node uptakes. Comparisons of 99m Tc - DCM2 performance with commercial radiopharmaceuticals in Brazil market for lymph node detection showed its upper profile. (author)

Positron emission tomographic imaging of tumors using monoclonal antibodies

Energy Technology Data Exchange (ETDEWEB)

Zalutsky, M.R.

1992-08-01

This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

Reduced 99mTc labelled NCA-95/CEA-antibody uptake in liver due to gentle antibody reconstitution

International Nuclear Information System (INIS)

Reske, S.N.; Buell, U.

1990-01-01

The influence of reconstituting a murine monoclonal IgG 1 antibody kit with pertechnetate Tc99m on antibody distribution in the liver, spleen and sternal bone marrow of patients was examined. The 99m Tc-labelled antibody used is directed against non-specific cross-reacting antigen (NCA-95) and carcinoembryonic antigen (CEA) and has been successfully applied for imaging tissue inflammation and bone marrow scanning. Radioactivity uptake was determined in the liver, spleen, bone marrow and a precordial background region in a consecutive series of 25 patients, examined with an antibody preparation, routinely radiolabelled according to the manufacturer's recommendations and in 14 patients, in whom the antibody was reconstituted with special care, avoiding bubble formation and dropping of buffer into the antibody-containing vial. Gentle compared with routine antibody reconstitution caused a highly significant reduction of the antibody uptake in the liver, as determined by count densities, normalized to injected dose and acquisition time (13.2±5.5 vs 20.1±6.0 cpm per pixel, anti x±SD, P=0.008). The liver to background ratio was reduced from 3.4±1.4 to 1.9±0.5 (P<0.001). Spleen, sternal bone marrow and precordial background count rates were not significantly affected. These results clearly demonstrate that gentle antibody reconstitution can decrease non-specific antibody uptake in the liver by 34%±6.4% (anti x±SEM). Thus, scan quality is improved, and the potential deleterious camouflage of underlying structures is avoided. (orig.)

Breast cancer imaging using radiolabelled somatostatin analogues

International Nuclear Information System (INIS)

Dalm, Simone U.; Melis, Marleen; Emmering, Jasper; Kwekkeboom, Dik J.; Jong, Marion de

2016-01-01

Imaging and therapy using radiolabelled somatostatin analogues are methods successfully used in patients with somatostatin receptor (SSTR)-expressing neuroendocrine tumours. Since these techniques were first introduced, many improvements have been made. SSTR expression has also been reported on breast cancer (BC). Currently mammography, magnetic resonance imaging and ultrasound are the most frequent methods used for BC imaging. Since SSTR expression on BC was demonstrated, clinical studies examining the feasibility of visualizing primary BC using SSTR radioligands have been performed. However, to date SSTR-mediated nuclear imaging is not used clinically in BC patients. The aim of this review is to assess whether recent improvements made within nuclear medicine may enable SSTR-mediated imaging to play a role in BC management. For this we critically analysed results of past studies and discussed the potential of the improvements made within nuclear medicine on SSTR-mediated nuclear imaging of BC. Seven databases were searched for publications on BC imaging with SSTR radioligands. The papers found were analysed by 3 individual observers to identify whether the studies met the pre-set inclusion criteria defined as studies in which nuclear imaging using radiolabelled SST analogues was performed in patients with breast lesions. Twenty-four papers were selected for this review including studies on SSTR-mediated nuclear imaging in BC, neuroendocrine BC and other breast lesions. The analysed studies were heterogeneous with respect to the imaging method, imaging protocol, patient groups and the radiolabelled SST analogues used. Despite the fact that the analysed studies were heterogeneous, sensitivity for primary BC ranged from 36–100%. In a subset of the studies LN lesions were visualized, but sensitivity was lower compared to that for primary tumours. A part of the studies included benign lesions and specificity ranged from 22–100%. Furthermore, false negatives and

Radiolocalization of bovine lymphosarcoma cells in athymic mice, using a monoclonal antibody against tumor-associated antigens

International Nuclear Information System (INIS)

Aida, Y.; Ochiai, K.; Ito, K.; Onuma, M.; Fujimori, F.; Fujimoto, Y.; Izawa, H.

1987-01-01

Mouse monoclonal antibody c 143 was purified and F(ab')2 fragments were generated by pepsin digestion and then radiolabeled with 125 I. The 125 I-labeled c 143 F(ab')2 fragments were injected into athymic mice bearing bovine lymphoid tumor cells. The fragments became preferentially localized in tumor tissues, but not in normal tissues, as determined by differential counting of tissue radioactivity. The fragments became localized specifically in those tumors that were reactive with c 143 in vitro, but did not become localized in unrelated tumors. Localization of labeled F(ab')2 fragments of a monoclonal antibody of the same isotype directed against Taka virus (a variant of Newcastle disease virus) was not observed in athymic mice bearing bovine lymphoid tumor cells. Tumors were detectable by radioimmunoscintigraphy, using radiolabeled c 143 F(ab')2 fragments, without background subtraction, and by use of silver-grain scattering in light microscopic autoradiography

A double labeling technique for performing immunocytochemistry and in situ hybridization in virus infected cell cultures and tissues

International Nuclear Information System (INIS)

Gendelman, H.E.; Moench, T.R.; Narayan, O.; Griffin, D.E.; Clements, J.E.

1985-01-01

This report describes a combined immunocytochemical and in situ hybridization procedure which allows visualization of cellular or viral antigens and viral RNA in the same cell. Cultures infected with visna or measles virus were fixed in periodate-lysine-paraformaldehyde-glutaraldehyde, stained by the avidin-biotin-peroxidase technique using antibodies to viral or cellular proteins and then incubated with radiolabeled specific DNA probes (in situ hybridization). This technique provides a new approach to the study of viral pathogenesis by: (1) identifying the types of cells which are infected in the host and (2) identifying points of blockade in the virus life cycle during persistent infections. (Auth.)

Biodistribution of radiolabeled lymphocytes

International Nuclear Information System (INIS)

Fawwaz, R.A.; Oluwole, S.; Wang, T.S.; Kuromoto, N.; Iga, C.; Hardy, M.A.; Alderson, P.O.

1985-01-01

Factors that might affect the biodistribution and clinical utility of radiolabeled lymphocytes were evaluated in experimental animals. Indium-111 (In-111) labeled lymphocytes obtained from peripheral blood, lymph node, or spleen were found in significant amounts in the lymphoid tissues of Lewis rats as early as 3 hours after infusion. A progressive increase in nodal activity with concomitant fall of activity in other organs followed, indicating active recirculation of the lymphocytes. In vitro irradiation of the In-111 labeled lymphocytes resulted in no detectable lymphocyte recirculation and/or reduced localization in lymphoid tissue. Splenectomized animals and those sensitized to an organ allograft before cell infusion showed increased activity in their bone marrow. These results suggest that the source of the injected cells, cell irradiation dose level and host sensitization should be considered when radiolabeled lymphocytes are being prepared for use in clinical diagnosis and therapy

In vivo amyloid-β imaging in the APPPS1-21 transgenic mouse model with a 89Zr- labeled monoclonal antibody.

Directory of Open Access Journals (Sweden)

Ann-Marie eWaldron

2016-03-01

Full Text Available Introduction: The accumulation of amyloid-β is a pathological hallmark of Alzheimer’s disease and is a target for molecular imaging probes to aid in diagnosis and disease monitoring. This study evaluated the feasibility of using a radiolabeled monoclonal anti-amyloid-β antibody (JRF/AβN/25 to non-invasively assess amyloid-β burden in aged transgenic mice (APPPS1-21 with μPET imaging.Methods: We investigated the antibody JRF/AβN/25 that binds to full-length Aβ. JRF/AβN/25 was radiolabeled with a [89Zr]-desferal chelate and intravenously injected into 12-13 month aged APPPS1-21 mice and their wild-type (WT controls. Mice underwent in vivo μPET imaging at 2, 4 and 7 days post injection and were sacrificed at the end of each time point to assess brain penetrance, plaque labeling, biodistribution and tracer stability. To confirm imaging specificity we also evaluated brain uptake of a non-amyloid targeting [89Zr]-labeled antibody (Trastuzumab as a negative control, additionally we performed a competitive blocking study with non-radiolabeled Df-Bz-JRF/AβN/25 and finally we assessed the possible confounding effects of blood retention. Results: Voxel-wise analysis of μPET data demonstrated significant [89Zr]-Df-Bz-JRF/AβN/25 retention in APPPS1-21 mice at all time points investigated. With ex vivo measures of radioactivity, significantly higher retention of [89Zr]-Df-Bz-JRF/AβN/25 was found at 4 and 7 day pi in APPPS1-21 mice. Despite the observed genotypic differences, comparisons with immunohistochemistry revealed that in vivo plaque labeling was low. Furthermore, pre-treatment with Df-Bz-JRF/AβN/25 only partially blocked [89Zr]-Df-Bz-JRF/AβN/25 uptake indicative of a high contribution of non-specific binding. Conclusion: Amyloid plaques were detected in vivo with a radiolabeled monoclonal anti-amyloid antibody. The low brain penetrance of the antibodies in addition to non-specific binding prevented an accurate estimation of plaque

Twenty years with monoclonal antibodies. State of the art - where do we go?

International Nuclear Information System (INIS)

Stigbrand, T.; Ullen, A.; Sandstroem, P.; Mirzaie-Joniani, H.; Sundstroem, B.; Nilsson, B.; Aerlestig, L.; Rossi Norrlund, R.; Riklund Aahlstroem, K.; Hietala, S.O.

1996-01-01

In this review, we have selected some parameters with the potential to improve the efficacy of RIL and RIT. Focus has partially been on the behaviour of radiolabelled antibodies in vivo in relation to properties and amounts of both target antigen and the antibodies used. If, out of the 28 factors listed in Table 1, some should be given preference in future work, it is our opinion that after the initial saturation of the tumour site a rapid decrease in redundant antibody is of significant importance. Furthermore, quantitative aspects of both antigens and antibodies should be more carefully evaluated when possible. By combining several of the listed approaches toward incresing efficiency, a more extensive use of RIL and RIT could be expected in the future. (orig.)

Radiolabelled RGD peptides for imaging and therapy

Energy Technology Data Exchange (ETDEWEB)

Gaertner, F.C.; Schwaiger, M.; Beer, A.J. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kessler, H. [Technische Universitaet Muenchen, Institute for Advanced Study and Center of Integrated Protein Science, Department of Chemistry, Garching (Germany); King Abdulaziz University, Chemistry Department, Faculty of Science, Jeddah (Saudi Arabia); Wester, H.-J. [Institute for Pharmaceutical Radiochemistry, Garching (Germany)

2012-02-15

Imaging of angiogenesis has become increasingly important with the rising use of targeted antiangiogenic therapies like bevacizumab (Avastin). Non-invasive assessment of angiogenic activity is in this respect interesting, e.g. for response assessment of such targeted antiangiogenic therapies. One promising approach of angiogenesis imaging is imaging of specific molecular markers of the angiogenic cascade like the integrin {alpha}{sub v}{beta}{sub 3}. For molecular imaging of integrin expression, the use of radiolabelled peptides is still the only approach that has been successfully translated into the clinic. In this review we will summarize the current data on imaging of {alpha}{sub v}{beta}{sub 3} expression using radiolabelled RGD peptides with a focus on tracers already in clinical use. A perspective will be presented on the future clinical use of radiolabelled RGD peptides including an outlook on potential applications for radionuclide therapy. (orig.)

Composition and method for stabilizing radiolabelled compounds using thiocarbonylated diethylenetriamines

International Nuclear Information System (INIS)

Tzodikov, N.R.

1984-01-01

Radiolabelled compounds, such as amino acids, nucleosides, vitamins and drugs, are stabilised against radiolytic decomposition by adding a solution of a thiocarbonylated diethylenetriamine to a solution of the radiolabelled compound. (author)

Application of 125I radioimmunoassay to measure inhibition of precipitin reactions using carbohydrate-specific antibodies

International Nuclear Information System (INIS)

Boullanger, P.H.; Nagpurkar, A.; Noujaim, A.A.; Lemieux, R.U.

1978-01-01

Antibodies raised to an artificial antigen with β-D-galactopyranosyl groups as antigenic determinants were purified using an immunoadsorbent prepared from the hapten involved in the synthesis of the antigen. In order to study the specificity of these antibodies, 125 I radiolabelling of either the artificial antigen or the antibody was used in the study of inhibitions of the precipitin reaction. The method, involving labelling of the artificial antigen and counting radioactivity in the supernatant, was found to be more accurate and faster than the usual methods based on measuring the amount of protein precipitated by chemical or spectroscopic methods. (author)

Radiolabelling of sperm cells with 99mTc-HMPAO. In vivo visualization of sperm cell migration in rabbits

International Nuclear Information System (INIS)

Bockisch, A.; Tennessee Univ., Knoxville, TN; Tennessee Univ., Knoxville, TN; Al-Hasani, S.; Ven, H.V.D.; Diedrich, K.; Krebs, D.; Posch, C.; Hotze, A.; Biersack, H.J.

1989-01-01

The present paper is the first descriptive radiolabeling of sperm cells in order to visualize their in vivo migration and imaging by scintigraphic technique, 99m Tc-HMPAO was used which combines favourable characteristics of both imaging modalities and radiation exposure. The radiolabeling yield was optimised for human sperm cells, and was increasing with the number of sperm cells, the amount of HMPAO, the 99m Tc-HMPAO concentration and the duration of the incubation. Incubation periods greater than 20 min, however, resulted only in a minor increase of labeling yield. A delay of more than 5 min between the labeling of the HMPAO with 99m Tc and initiation of the incubation of the sperm cells with the 99m Tc-HMPAO also decreased the maximum labeling yield. The radiolabeled cells were found to be stable and after 18 h > 93% of the activity was still bound to the sperm cells. After insemination of labeled sperm cells in ovulating rabbits the accumulation of the cells in the Fallopian tubes and their subsequent migration could be clearly visualized by scintigraphic techniques in vivo. (orig.) [de

Fluorine-18 radiolabeling of low-density lipoproteins: a potential approach for characterization and differentiation of metabolism of native and oxidized low-density lipoproteins in vivo

International Nuclear Information System (INIS)

Pietzsch, Jens; Bergmann, Ralf; Rode, Katrin; Hultsch, Christina; Pawelke, Beate; Wuest, Frank; Hoff, Joerg van den

2004-01-01

Oxidative modification of low-density lipoprotein (LDL) is regarded as a crucial event in atherogenesis. Assessing the metabolic fate of oxidized LDL (oxLDL) in vivo with radiotracer techniques is hindered by the lack of suitable sensitive and specific radiolabeling methods. We evaluated an improved methodology based on the radiolabeling of native LDL (nLDL) and oxLDL with the positron emitter fluorine-18 ( 18 F) by conjugation with N-succinimidyl-4-[ 18 F]fluorobenzoate ([ 18 F]SFB). We investigated whether radiolabeling of LDL induces adverse structural modifications. Results suggest that radiolabeling of both nLDL and oxLDL using [ 18 F]SFB causes neither additional oxidative structural modifications of LDL lipids and proteins nor alteration of their biological activity and functionality, respectively. Thus, radiolabeling of LDL using [ 18 F]SFB could prove to be a promising approach for studying the kinetics of oxLDL in vivo

Fluorine-18 radiolabeling of low-density lipoproteins: a potential approach for characterization and differentiation of metabolism of native and oxidized low-density lipoproteins in vivo.

Science.gov (United States)

Pietzsch, Jens; Bergmann, Ralf; Rode, Katrin; Hultsch, Christina; Pawelke, Beate; Wuest, Frank; van den Hoff, Joerg

2004-11-01

Oxidative modification of low-density lipoprotein (LDL) is regarded as a crucial event in atherogenesis. Assessing the metabolic fate of oxidized LDL (oxLDL) in vivo with radiotracer techniques is hindered by the lack of suitable sensitive and specific radiolabeling methods. We evaluated an improved methodology based on the radiolabeling of native LDL (nLDL) and oxLDL with the positron emitter fluorine-18 ((18)F) by conjugation with N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB). We investigated whether radiolabeling of LDL induces adverse structural modifications. Results suggest that radiolabeling of both nLDL and oxLDL using [(18)F]SFB causes neither additional oxidative structural modifications of LDL lipids and proteins nor alteration of their biological activity and functionality, respectively. Thus, radiolabeling of LDL using [(18)F]SFB could prove to be a promising approach for studying the kinetics of oxLDL in vivo.

Novel approaches to cancer targeting using epitope-binding properties that mimic monoclonal antibodies

International Nuclear Information System (INIS)

1998-01-01

The investigators have extensive experience in all of the techniques required for this project including: animal models of tumors, quantitative autoradiography, radiochemistry, peptide synthesis, organic synthesis, molecular biology, kinetic modeling and radionuclide imaging both with single photon and PET agents. Preliminary results and progress in the following areas are presented: (1) Establishment of an in vivo tumor model and successful targeting of this tumor using monoclonal antibodies raised to p185 erbB2 , (2a) Screening of a synthetic peptide combinatorial library, (2b) Screening of a phage display peptide library, (3) Determination of the epitope recognized by ICR12, (4) Radiolabeling with 99m Tc, 18 F and * I (radioiodines), (5) High resolution positron emission tomography (PET) studies of tumors, and (6) Development of a high resolution (∼mm) PET camera

Circulating immune complexes in the serum in systemic lupus erythematosus and in carriers of hepatitis B antigen: quantitation by binding to radiolabeled Cl/sub q/

International Nuclear Information System (INIS)

Nydegger, U.E.; Lambert, P.H.; Gerber, H.; Miescher, P.A.

1974-01-01

A sensitive and reproducible procedure fr the detection of souble immune complexes in sera from patients with various immunopathological disorders is reported. Radiolabeled Clq is reacted with sera containing immune complexes. Separation of free from complex bound [ 125 I]Clq is achieved by selective precipitation with polyethylene glycol (PEG). The minimal amount of aggregated immunoglobulins thus detected is about 10 μg and that of soluble human IgG-anti-IgG complexes is about 3 μg of complexed antibody. Some immune complexes formed in large antigen excess (Ag 2 Ab) can still be detected by this radiolabeled Clq bining assay. In a second step, this radiolabeled Clq binding assay was applied to an experimental model of immune complex disease and was shown to be efficient for the detection of in vivo formed immune complexes. Finally, the technique could be applied to the study of sera from patients with systemic lupus erythematosus (SLE) or to carriers of the Hepatitis B antigen (HB-Ag). Particularly high values were seen in active disease, a finding which was confirmed by follow-up studies performed with four SLE patients. No increased [ 125 I]Clq binding was seen in 18 healthy carriers of the HB-Ag; whereas, sera from carriers with hepatitis appear to precipitate increased [ 125 I]Clq percentages: 7/24 cases with acute transient and 4/7 cases with chronic persistent hepatitis were found to increasingly bind [ 125 I]Clq. The results were also used for a correlative study of [ 125 I]Clq binding to IgG levels in the sera but increased [ 125 I]Clq binding could not be attributed to high serum IgG levels which are likely to account for the evaluation of immune complex diseases in human pathology. (U.S.)

Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy †

Science.gov (United States)

Sihver, Wiebke; Pietzsch, Jens; Krause, Mechthild; Baumann, Michael; Steinbach, Jörg; Pietzsch, Hans-Jürgen

2014-01-01

The epidermal growth factor receptor (EGFR) has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a) chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b) with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment. PMID:24603603

Radiolabelling for immunoassay

International Nuclear Information System (INIS)

Chapman, R.S.

1998-01-01

Since the early 1960s labelled compounds employed in immunoassay techniques, both radioimmunoassay and immunoradiometric assay, have involved radioisotopes typically 3 H (tritium) and 125 Iodine. With the advent of increasingly stringent governmental regulations regarding usage and disposal of radioisotopes and the impetus of research towards improved immunoassay sensitivity following the discovery of monoclonal antibodies and their application to excess reagent immunometric assay methodology, radioisotopic labels are gradually being replaced by non-isotopic labels: enzyme, fluorescence and chemiluminescence

Radioimmunodetection of human leukemia with anti-interleukin-2 receptor antibody in severe combined immunodeficiency mice

International Nuclear Information System (INIS)

Hosono, Makoto; Takaori-Kondo, Akifumi; Zheng-Sheng, Yao; Kobayashi, Hisataka; Hosono, Masako N.; Sakahara, Harumi; Imada, Kazunori; Okuma, Minoru; Uchiyama, Takashi; Konishi, Junji

1995-01-01

Anti-Tac monoclonal antibody recognizes human interleukin-2 receptor, which is overexpressed in leukemic cells of most adult T-cell leukemia (ATL) patients. To examine the potency of anti-Tac for targeting of ATL, biodistributions of intravenously administered 125 I- and 111 In-labeled anti-Tac were examined in severe combined immunodeficiency (SCID) mice inoculated with ATL cells. Significant amounts of radiolabeled anti-Tac were found in the spleen and thymus. The trafficking of ATL cells in SCID mice was detected using 111 In-oxine-labeled ATL cells. These results were coincident with the histologically confirmed infiltration of ATL cells. The radiolabeled anti-Tac seemed potent for targeting of ATL

Application and evolution of several therapy nuclides labelled antibody in tumour therapy

International Nuclear Information System (INIS)

He Jiaheng; Luo Shunzhong; Wang Guanquan

2004-12-01

Radiolabeled Monoclonal antibody had a lot of merits, such as decreasing the lesion because of the external exposure to normal tissue and the whole body, destroying cancer cells which McAb could not reach, and little ornamentation effect by Antigen. Therefor, it gradually became a kind of guiding therapy method which endowed with practical value. Up to now, the radionuclides which be used for tumour radioimmunotherapy included mostly 131 I, 90 Y, 188 Re, 186 Re, 153 Sm, 211 At, et al. The application and evolution of several therapy nuclides labelled antibody in tumour therapy are in troduced. (authors)

Radiolabeled amino acids : Basic aspects and clinical applications in oncology

NARCIS (Netherlands)

Jager, PL; Vaalburg, W; Pruim, J; de Vries, EGE; Langen, KJ; Piers, DA

As the applications of metabolic imaging are expanding, radiolabeled amino acids may gain increased clinical interest, This review first describes the basic aspects of amino acid metabolism, then continues with basic aspects of radiolabeled amino acids, and finally describes clinical applications,

Radioactive EGFR Antibody Cetuximab in Multimodal Cancer Treatment: Stability and Synergistic Effects With Radiotherapy

International Nuclear Information System (INIS)

Rades, Dirk; Wolff, Christian; Nadrowitz, Roger; Breunig, Christian; Schild, Steven E.; Baehre, Manfred; Meller, Birgit

2009-01-01

Purpose: Systemic therapies when added to whole brain radiotherapy have failed to improve the survival of patients with multiple brain metastases. The epidermal growth factor receptor antibody cetuximab is an attractive option, if it is able to cross the blood-brain barrier. This might be proven with molecular imaging if the radiolabeled antibody is stable long enough to be effective. This study investigated the stability of radiolabeled cetuximab (Erbitux) ( 131 I-Erbi) and potential synergistic effects with radiotherapy in vitro. Methods and Materials: Two cell lines were investigated, A431 with numerous epidermal growth factor receptors, and JIMT without epidermal growth factor receptors. We labeled 0.4 mg cetuximab with 50 MBq of [ 131 I] iodide. Stability was determined for 72 h. The cell cultures were incubated with 131 I-Erbi or cold cetuximab for 72 h. Uptake and cell proliferation were measured every 24 h after no radiotherapy or irradiation with 2, 4, or 10 Gy. Results: The radiolabeling yield of 131 I-Erbi was always >80%. The radiochemical purity was still 93.6% after 72 h. A431 cells showed a 131 I-Erbi uptake about 100-fold greater than the JIMT controls. After 48 h, the A431 cultures showed significantly decreased proliferation. At 72 h after irradiation, 131 I-Erbi resulted in more pronounced inhibition of cell proliferation than the cold antibody in all radiation dose groups. Conclusion: 131 I-Erbi was stable for ≤72 h. Radiotherapy led to increased tumor cell uptake of 131 I-Erbi. Radiotherapy and 131 I-Erbi synergistically inhibited tumor cell proliferation. These results provide the prerequisite data for a planned in vivo study of whole brain radiotherapy plus cetuximab for brain metastases.

In vitro evaluation of avidin antibody pretargeting using 211At-labeled and biotinylated poly-L-lysine as effector molecule

DEFF Research Database (Denmark)

Frost, Sofia H L; Jensen, Holger Lau; Lindegren, Sture

2010-01-01

Pretargeting is an approach for enhancing the therapeutic index of radioimmunotherapy by separating the administrations of tumor-targeting substance and radiolabel. In this study, a pretargeting model system of avidin-conjugated monoclonal antibody trastuzumab and biotinylated, (211)At-labeled poly...

Radioimmunodetection of colorectal cancer, using anti-CEA monoclonal antibodies

International Nuclear Information System (INIS)

Murayama, Hiroki; Watanabe, Tadashi; Tadokoro, Masanori; Takagi, Hiroshi; Sakuma, Sadayuki; Sakamoto, Junichi.

1989-01-01

Aiming at radioimmunodetection of colorectal cancer, anti-CEA monoclonal antibodies (CEA102) were produced by immunization with purified CEA. CEA102 showed high specificity with clorectal cancer by mixed hemadsorption assay and immunoperoxidase technique. The antigen detected by CEA102 was confirmed to be carcinoembryonic antigen (CEA) and its molecular weight was estimated to be ca. 180,000 by biochemical analysis. The in vivo study using nude mice grafted a human colorectal cancer or a human malignant melanoma showed greater accumulation of 125 I-labeled CEA102 in CEA-positive colorectal cancer than in nude mouse tissues and CEA-negative malignant melanoma. Moreover we successfully obtained scans with good localization of the grafted colorectal cancer on FCR (Fuji Computed Radiography). Using 131 I-labeled CEA102 liver metastasis in the patient with colorectal cancer was successfully detected by external scanning with γ-camera. These results suggest that radiolabeled CEA102 is useful for the detection of colorectal cancer. (author)

Fluorine-18 radiolabeling of low-density lipoproteins: a potential approach for characterization and differentiation of metabolism of native and oxidized low-density lipoproteins in vivo

Energy Technology Data Exchange (ETDEWEB)

Pietzsch, Jens [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Bergmann, Ralf [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Rode, Katrin [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Hultsch, Christina [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Pawelke, Beate [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Wuest, Frank [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany); Hoff, Joerg van den [PET-Center, Institute of Bioinorganic and Radiopharmaceutical Chemistry, Research Center Rossendorf Dresden, P.O. Box 51 01 19, D-01314 Dresden (Germany)

2004-11-01

Oxidative modification of low-density lipoprotein (LDL) is regarded as a crucial event in atherogenesis. Assessing the metabolic fate of oxidized LDL (oxLDL) in vivo with radiotracer techniques is hindered by the lack of suitable sensitive and specific radiolabeling methods. We evaluated an improved methodology based on the radiolabeling of native LDL (nLDL) and oxLDL with the positron emitter fluorine-18 ({sup 18}F) by conjugation with N-succinimidyl-4-[{sup 18}F]fluorobenzoate ([{sup 18}F]SFB). We investigated whether radiolabeling of LDL induces adverse structural modifications. Results suggest that radiolabeling of both nLDL and oxLDL using [{sup 18}F]SFB causes neither additional oxidative structural modifications of LDL lipids and proteins nor alteration of their biological activity and functionality, respectively. Thus, radiolabeling of LDL using [{sup 18}F]SFB could prove to be a promising approach for studying the kinetics of oxLDL in vivo.

Thrombus imaging in a primate model with antibodies specific for an external membrane protein of activated platelets

International Nuclear Information System (INIS)

Palabrica, T.M.; Furie, B.C.; Konstam, M.A.; Aronovitz, M.J.; Connolly, R.; Brockway, B.A.; Ramberg, K.L.; Furie, B.

1989-01-01

The activated platelet is a potential target for the localization of thrombi in vivo since, after stimulation and secretion of granule contents, activated platelets are concentrated at sites of blood clot formation. In this study, we used antibodies specific for a membrane protein of activated platelets to detect experimental thrombi in an animal model. PADGEM (platelet activation-dependent granule-external membrane protein), a platelet alpha-granule membrane protein, is translocated to the plasma membrane during platelet activation and granule secretion. Since PADGEM is internal in unstimulated platelets, polyclonal anti-PADGEM and monoclonal KC4 antibodies do not bind to circulating resting platelets but do interact with activated platelets. Dacron graft material incubated with radiolabeled KC4 or anti-PADGEM antibodies in the presence of thrombin-activated platelet-rich plasma bound most of the antibody. Imaging experiments with 123I-labeled anti-PADGEM in baboons with an external arterial-venous Dacron shunt revealed rapid uptake in the thrombus induced by the Dacron graft; control experiments with 123I-labeled nonimmune IgG exhibited minimal uptake. Deep venous thrombi, formed by using percutaneous balloon catheters to stop blood flow in the femoral vein of baboons, were visualized with 123I-labeled anti-PADGEM. Thrombi were discernible against blood pool background activity without subtraction techniques within 1 hr. No target enhancement was seen with 123I-labeled nonimmune IgG. 123I-labeled anti-PADGEM cleared the blood pool with an initial half-disappearance time of 6 min and did not interfere with hemostasis. These results indicate that radioimmunoscintigraphy with anti-PADGEM antibodies can visualize thrombi in baboon models and is a promising technique for clinical thrombus detection in humans

The influence of proteasome inhibitor MG132, external radiation and unlabeled antibody on the tumor uptake and biodistribution of 188Re-labeled anti-E6 C1P5 antibody in cervical cancer in mice

Science.gov (United States)

Phaeton, Rébécca; Wang, Xing Guo; Einstein, Mark H.; Goldberg, Gary L.; Casadevall, Arturo; Dadachova, Ekaterina

2009-01-01

Background Human Papillomavirus (HPV) infection is considered a necessary step for the development of cervical cancer and >95% of all cervical cancers have detectable HPV sequences. We have recently demonstrated the efficacy of radioimmunotherapy (RIT) which targeted viral oncoprotein E6 in treatment of experimental cervical cancer We hypothesized that pre-treatment of tumor cells with various agents which cause cell death and/or elevation of E6 levels would increase the accumulation of radiolabeled antibodies to E6 in cervical tumors. Methods HPV-16 positive CasKi cells were treated in vitro with up to 6 Gy of external radiation, or proteasome inhibitor MG-132 or unlabeled anti-E6 antibody C1P5 and cell death was assessed. Biodistribution of 188Rhenium (188Re)-labeled C1P5 antibody was performed in both control and radiation MG-132 treated CasKi tumor-bearing nude mice. Results . 188Re-C1P5 antibody demonstrated tumor specificity and very low uptake and fast clearance from the major organs. The amount of tumor uptake was enhanced by MG-132 but was unaffected by pre-treatment with radiation. In addition, in vitro studies demonstrated an unanticipated effect of unlabeled antibody on the amount of cell death, a finding that was suggested by our previous in vivo studies in CasKi tumor model. Conclusion We demonstrated that pre-treatment of cervical tumors with proteasome inhibitor MG-132 and with unlabeled antibody to E6 can serve as a means to generate non-viable cancer cells and to elevate the levels of target oncoproteins in the cells for increasing the accumulation of targeted radiolabeled antibodies in tumors. These results favor further development of RIT of cervical cancers targeting viral antigens. PMID:20127955

Radiolabelled peptides for oncological diagnosis

Energy Technology Data Exchange (ETDEWEB)

Laverman, Peter; Boerman, Otto C.; Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Sosabowski, Jane K. [Queen Mary University of London, Centre for Molecular Oncology, Barts Cancer Institute, London (United Kingdom)

2012-02-15

Radiolabelled receptor-binding peptides targeting receptors (over)expressed on tumour cells are widely under investigation for tumour diagnosis and therapy. The concept of using radiolabelled receptor-binding peptides to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. The {sup 111}In-labelled somatostatin analogue octreotide (OctreoScan trademark) is the most successful radiopeptide for tumour imaging, and was the first to be approved for diagnostic use. Based on the success of these studies, other receptor-targeting peptides such as cholecystokinin/gastrin analogues, glucagon-like peptide-1, bombesin (BN), chemokine receptor CXCR4 targeting peptides, and RGD peptides are currently under development or undergoing clinical trials. In this review, we discuss some of these peptides and their analogues, with regard to their potential for radionuclide imaging of tumours. (orig.)

Core antigen and circulating anti-core antibody in hepatitis B infection

Energy Technology Data Exchange (ETDEWEB)

Howard, C R; Zuckerman, A J [London School of Hygiene and Tropical Medicine (UK)

1977-02-01

Core antigen was obtained from the sera of persistent chronic carriers of hepatitis B virus by centrifugation and treatment with Nonidet P40 and 2-mercaptoethanol. The separated core antigen was radiolabelled and identified as a nucleoprotein structure of buoyant density 1.36 g/cm/sup 3/ and possessing an isoelectric point of 4.4. This material was employed in a radioimmnoassay procedure of high sensitivity for the detection of core antibody. In a series of sera from patients with acute type B hepatitis, core antibody was demonstrated 2 to 3 weeks after the onset of jaundice during the period of surface antigenaemia. The presence of core antibody may therefore provide an accurate serological marker for the detection of active or recent virus replication in future epidemiological studies of hepatitis B infection.

Immunoscintigraphy and radioimmunotherapy in Cuba: experiences with labeled monoclonal antibodies for cancer diagnosis and treatment (1993-2013).

Science.gov (United States)

Peña, Yamilé; Perera, Alejandro; Batista, Juan F

2014-01-01

tumor response in a substantial percentage of patients. CONCLUSIONS Cuba has experience with production and radiolabeling of monoclonal antibodies, which facilitates use of these agents. Studies in Cuba conducted by the Clinical Research Center over the past 20 years have yielded satisfactory results. Evidence obtained suggests promising potential of monoclonal antibodies and nuclear medicine, with immunoscintigraphy and radioimmunotherapy techniques providing alternatives for cancer diagnosis and treatment in Cuba.

A comparison of labelled antibody methods for the detection of virus antigens in cell monolayers

International Nuclear Information System (INIS)

Oram, J.D.; Crooks, A.J.

1979-01-01

A number of labelled antibody methods have been applied to the detection of Semliki Forest virus antigens after replication of the virus in monolayers of host cells in multi-well polystyrene plates. The importance of several reaction variables has been investigated and the sensitivity of the methods compared for different periods of virus replication. Direct assays with radio-labelled antibody (RLA) and indirect assays peroxidase-antiperoxidase complexes (PAP) were equally sensitive. Direct and indirect assays using enzyme-linked antibodies (ELA) were slightly less sensitive than the direct RLA and PAP methods but were more sensitive than the indirect RLA or fluorescent antibody (FLA) methods. Direct assays using ELA were more rapid and easier to perform than the other assay methods. (Auth.)

The use of 14C-FIAU to predict bacterial thymidine kinase presence: Implications for radiolabeled FIAU bacterial imaging

International Nuclear Information System (INIS)

Peterson, Kristin L.; Reid, William C.; Freeman, Alexandra F.; Holland, Steven M.; Pettigrew, Roderic I.; Gharib, Ahmed M.; Hammoud, Dima A.

2013-01-01

Currently available infectious disease imaging techniques cannot differentiate between infection and sterile inflammation or between different types of infections. Recently, radiolabeled FIAU was found to be a substrate for the thymidine kinase (TK) enzyme of multiple pathogenic bacteria, leading to its translational use in the imaging of bacterial infections. Patients with immunodeficiencies, however, are susceptible to a different group of pathogenic bacteria when compared to immunocompetent subjects. In this study, we wanted to predict the usefulness of radiolabeled FIAU in the detection of bacterial infections commonly occurring in patients with immunodeficiencies, in vitro, prior to attempting in vivo imaging with 124 I-FIAU-PET. Methods: We obtained representative strains of bacterial pathogens isolated from actual patients with genetic immunodeficiencies. We evaluated the bacterial susceptibility of different strains to the effect of incubation with FIAU, which would implicate the presence of the thymidine kinase (TK) enzyme. We also incubated the bacteria with 14 C-FIAU and consequently measured its rate of incorporation in the bacterial DNA using a liquid scintillation counter. Results: Unlike the other bacterial strains, the growth of Pseudomonas aeruginosa was not halted by FIAU at any concentration. All the tested clinical isolates demonstrated different levels of 14 C-FIAU uptake, except for P. aeruginosa. Conclusion: Radiolabeled FIAU has been successful in delineating bacterial infections, both in preclinical and pilot translational studies. In patients with immunodeficiencies, Pseudomonas infections are commonly encountered and are usually difficult to differentiate from fungal infections. The use of radiolabeled FIAU for in vivo imaging of those patients, however, would not be useful, considering the apparent lack of TK enzyme in Pseudomonas. One has to keep in mind that not all pathogenic bacteria possess the TK enzyme and as such will not all

A new rapid immunohistochemical staining technique using the EnVision antibody complex.

Science.gov (United States)

Kämmerer, U; Kapp, M; Gassel, A M; Richter, T; Tank, C; Dietl, J; Ruck, P

2001-05-01

Rapid immunohistochemical investigation, in addition to staining with hematoxylin and eosin, would be useful during intraoperative frozen section diagnosis in some cases. This study was undertaken to investigate whether the recently described EnVision system, a highly sensitive two-step immunohistochemical technique, could be modified for rapid immunostaining of frozen sections. Forty-five primary antibodies were tested on frozen sections from various different tissues. After fixation in acetone for 1 min and air-drying, the sections were incubated for 3 min each with the primary antibody, the EnVision complex (a large number of secondary antibodies and horseradish peroxidase coupled to a dextran backbone), and the chromogen (3,3'diaminobenzidine or 3-amino-9-ethylcarbazole). All reactions were carried out at 37C. Specific staining was seen with 38 antibodies (including HMB-45 and antibodies against keratin, vimentin, leukocyte common antigen, smooth muscle actin, synaptophysin, CD34, CD3, CD20, and prostate-specific antigen). A modification of the EnVision method allows the detection of a broad spectrum of antigens in frozen sections in less than 13 min. This method could be a useful new tool in frozen section diagnosis and research. (J Histochem Cytochem 49:623-630, 2001)

Identification and characterization of surface antigens in parasites, using radiolabelling techniques

International Nuclear Information System (INIS)

Ramasamy, R.

1982-04-01

Surface proteins of Schistosoma sp and Leishmania sp were studied using 125-Iodine as tracer. The surface proteins were labelled by the Lactoperoxidase method and the proteins then separated using SDS PAG electrophoresis and autoradiography. The possible immunogens were then separated using immunoprecipitation and Fluorescent Antibody techniques using sera from patients or from artificially immunized rabbits. Four common antigens were identified from the surfaces of male and female adult worms, cercariae and schistosomulae of S.mansoni. These antigens, which had molecular weights of 150,000, 78,000, 45,000, and 22,000 were also isolated from the surfaces of S.haematobium adults. The surface antigens on promastigotes of a Kenyan strain of Leishmania donovani were separated into three protein antigens with molecular weights of 66,000, 59,000 and 43,000 respectively. The 59,000 molecular weight antigen was a glycoprotein and was common to promastigotes of an American and Indian strain of L.donovani and to L.braziliensis mexicana. None of the isolated antigens have been shown to have a protective effect when vaccinated into mice, but the study illustrates the value of radionuclide tracers in the unravelling of the mosaic of antigens which parasites possess

Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

International Nuclear Information System (INIS)

Kuge, Yuji; Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo; Zhao, Yan; Kiyono, Yasushi; Shiomi, Masashi

2010-01-01

Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of 99m Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG 3 and negative control IgG 3 were radiolabelled with 99m Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield 99m Tc-MT1-MMP mAb and 99m Tc-IgG 3 , respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. 99m Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional 99m Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p 99m Tc-IgG 3 accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest 99m Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 ± 1.9, %ID x BW/mm 2 x 10 2 ), followed in decreasing order by fibroatheromatous (1.8 ± 1.3), collagen-rich (1.6 ± 1.0) and neointimal lesions (1.5 ± 1.5). In contrast, 99m Tc-IgG 3 accumulation was almost independent of the histological grade of lesions. Higher 99m Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with 99m Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

Radiolabeling Silica-Based Nanoparticles via Coordination Chemistry: Basic Principles, Strategies, and Applications.

Science.gov (United States)

Ni, Dalong; Jiang, Dawei; Ehlerding, Emily B; Huang, Peng; Cai, Weibo

2018-03-20

As one of the most biocompatible and well-tolerated inorganic nanomaterials, silica-based nanoparticles (SiNPs) have received extensive attention over the last several decades. Recently, positron emission tomography (PET) imaging of radiolabeled SiNPs has provided a highly sensitive, noninvasive, and quantitative readout of the organ/tissue distribution, pharmacokinetics, and tumor targeting efficiency in vivo, which can greatly expedite the clinical translation of these promising NPs. Encouraged by the successful PET imaging of patients with metastatic melanoma using 124 I-labeled ultrasmall SiNPs (known as Cornell dots or C dots) and their approval as an Investigational New Drug (IND) by the United States Food and Drug Administration, different radioisotopes ( 64 Cu, 89 Zr, 18 F, 68 Ga, 124 I, etc.) have been reported to radiolabel a wide variety of SiNPs-based nanostructures, including dense silica (dSiO 2 ), mesoporous silica (MSN), biodegradable mesoporous silica (bMSN), and hollow mesoporous silica nanoparticles (HMSN). With in-depth knowledge of coordination chemistry, abundant silanol groups (-Si-O-) on the silica surface or inside mesoporous channels not only can be directly used for chelator-free radiolabeling but also can be readily modified with the right chelators for chelator-based labeling. However, integrating these labeling strategies for constructing stably radiolabeled SiNPs with high efficiency has proven difficult because of the complexity of the involved key parameters, such as the choice of radioisotopes and chelators, nanostructures, and radiolabeling strategy. In this Account, we present an overview of recent progress in the development of radiolabeled SiNPs for cancer theranostics in the hope of speeding up their biomedical applications and potential translation into the clinic. We first introduce the basic principles and mechanisms for radiolabeling SiNPs via coordination chemistry, including general rules of selecting proper

Localization of 111In- and 125I-labeled monoclonal antibody in guinea pigs bearing line 10 hepatocarcinoma tumors

International Nuclear Information System (INIS)

Bernhard, M.I.; Hwang, K.M.; Foon, K.A.

1983-01-01

A murine monoclonal antibody (D3) with demonstrated specificity for the guinea pig line 10 hepatocarcinoma (L10) was radiolabeled with either 125 I or 111 In and used to image dermal tumors in vivo. In one set of experiments, L10 tumors were established middorsally in one group of animals, and the similarly derived, antigenically distinct line 1 tumor was established in another group of animals. In spite of background imaging of liver, kidney, and spleen, L10 tumors were visualized clearly. Incorporation of radiolabel was demonstrated to predominate in the L10 tumor. In a separate set of experiments, L10 and line 1 tumors were established in contralateral thighs in the same animals. L10 tumors were visualized clearly, and tissue uptake of radiolabel was demonstrated to reside predominantly in the L10 tumor

Site-specific conjugation and labelling of prostate antibody 7E11C5.3 (CYT-351) with technetium-99m

International Nuclear Information System (INIS)

Stalteri, M.A.; Mather, S.J.; Belinka, B.A.; Coughlin, D.J.; Chengazi, V.U.; Britton, K.E.

1997-01-01

Attachment of chelating agents to the sugar residues of antibodies for subsequent radiolabelling is an attractive approach since it may have less effect on the immunoreactivity than attachment through lysine residues, which are distributed throughout the antibody and may be present near the antigen binding site. We have attached a new hydrazide-linked chelator CYT-395 (Cytogen Corp., Princeton, N.J.) to the sugar residues of the anti-prostate monoclonal antibody 7E11C5.3 and optimised the conditions for labelling the conjugate with technetium-99m in order to compare the conjugate to 7E11C5.3 antibody labelled directly with technetium using a mercaptoethanol reduction technique. Labelling yields of 70%-90% were obtained at specific activities up to 2000 MBq/mg antibody. The stability of the technetium-labelled conjugate in plasma or to a challenge with 0.1 or 1.0 mM cysteine was similar to that of direct-labelled antibody. In nine patients with prostate cancer, the plasma clearance of the labelled conjugate followed a two-compartment model, with an average β-phase half-life of 31.4±3.9 h. The average urinary clearance at 24 h was 15.3±5.0% of the injected dose. In this group of patients there was no significant difference between the blood and urine clearance of the labelled conjugate, and the clearances of the direct-labelled antibody. (orig.). With 5 figs

Radiolabeling and Preclinical Evaluation of 131I-anti-CD20 for Non-Hodgkin's Lymphomas Therapy

International Nuclear Information System (INIS)

Kullaprawittaya, Usa; Khongpetch, Pranom; Ngamprayad, Tippanan; Nuanchuen, Suphatphong

2007-08-01

Full text: In this study, a monoclonal anti-CD20 was developed for radioimmunotherapy of non-Hodgkin's B-cell lymphoma by reacting anti-CD20 with iodine-131 using iodogen procedure. It was found that radiochemical yield was > 95 % independently of incubation time and the antibody could be conjugated with iodine-131 up to 10 mCi/mg. The radiolabeled antibody exhibited excellent retention of immunoreactivity with radio incorporations >95% for 6 hr at 4 o C. In vitro stability tests showed minimal loss of iodine-131 from the conjugate in the presence of cysteine and in human serum at 37 o C. Biodistribution study in normal ICR mice showed higher uptake by the liver, kidney and intestines but lower thyroid uptake compared to 131 I -MIBG. Biodistribution studies confirmed the in vitro stability of 131 I -anti-CD20. In particular, excellent in vivo retention of iodine-131 was demonstrated by lower thyroid accumulation over 48 hr. A favorable biological distribution of 131 I -anti-CD20 suggests this radiopharmaceutical may be effectively used in the therapy of non-Hodgkin's lymphoma

Determination of antibody levels to Candida albicans in healthy and hospitalised adults using a radioimmunoassay

International Nuclear Information System (INIS)

Cobb, S.J.; Parratt, D.

1978-01-01

A radioimmunoassay for antibody to Candida albicans is described. The test uses whole, killed of organisms as the antigen and radiolabelled sheep anti-human globulins to quantitate different classes of antibody to C. albicans. The assay has been compared with an Ouchterlony precipitin method and found to be simpler, more rapid, and more sensitive than the latter. Results obtained from two groups of symptomless adults indicated that the range of antibody level was wider for a hospitalised group than for a group of blood transfusion donors, particularly in respect of IgG and IgA antibody. The reason for the increase of antibody in hospital patients was not clear but may have been related to antibiotic therapy. The difficulties in interpretation of Candida serology have therefore been re-assessed in the light of more detailed knowledge of the range and type of antibody to be expected in normal individuals. (author)

Cancer imaging with CEA antibodies: historical and current perspectives.

Science.gov (United States)

Goldenberg, D M

1992-01-01

This article reviews the history and status of cancer imaging with radiolabeled antibodies against carcinoembryonic antigen (CEA). Although CEA and many other cancer-associated antigens are not distinct for neoplasia, the quantitative increase of these markers in malignant tissues provides a sufficient differential for selective antibody targeting. Animal studies with xenografted human tumors provided the first evidence of the prospects of this technology, followed by initial clinical success with purified goat whole IgG antibodies to CEA, labeled with 131I and with the use of dual-isotope subtraction methods. Subsequently, improved and earlier imaging could be accomplished with monoclonal antibody fragments, which then would permit the use of shorter-lived radionuclides, such as 111In, 123I, and 99mTc. The preferred use of a monoclonal anti-CEA IgG Fab' fragment, labeled with 99mTc by a recently developed, simple and rapid kit, has enabled the detection of small lesions, including those in the liver, within 4 h of injection. By means of SPECT imaging, a high sensitivity and specificity for RAID could be achieved.

Novel approaches to tumor imaging in mice: pre targeting with radiolabeled peptide nucleic acid

International Nuclear Information System (INIS)

Hnatowich, D.J.; Qu, T.; Chang, F.; Rusckowski, M.

1997-01-01

Full text.Since targeting of tumour by conventional methods is not consistently favorable, we have considered pre targeting with separate administrations of anti tumour antibody and radiolabel. As an alternative to streptavidin and biotin for this application, we earlier considered single stranded peptide nucleic acid (PNA) bound to an irrelevant protein administered first and allowed to diffuse non specifically into tumour. This was followed later by the administration of 99 m Tc labeled complementary PNA. We now report on the first studies with PNA conjugated anti tumour antibody to allow specific binding. PNA was conjugated to the NRLU-10 IgG antibody while the complementary PNA (amine derivatized) was labeled with ((m Tc using MAG3. LS174T tumour-bearing nude mice received IV 200 ug of the PNA-antibody conjugate and 20 h later, received IV 100 ug (130 uCl) of 99m Tc- complementary PNA. Animals were imaged and sacrificed 5 h later. Because of rapid clearance, at sacrifice all tissue levels of 99 m Tc were low, the highest being kidneys at about 4%ID/gm. Tumour uptake was 0.55%ID/gm for the study animals vs. 0. 13 for controls and tumour/muscle ratios were 9.8 vs. 3.6 respectively. These values represent a 2.5-fold improvement in localization over the nonspecific study. The whole body images also reflected the superior targeting of study vs. control animals. We conclude that single-stranded PNAs should be a useful alternative to streptavidin and biotin for pre targeting studies

In vitro evaluation, biodistribution and scintigraphic imaging in mice of radiolabeled anthrax toxins

International Nuclear Information System (INIS)

Dadachova, Ekaterina; Rivera, Johanna; Revskaya, Ekaterina; Nakouzi, Antonio; Cahill, Sean M.; Blumenstein, Michael; Xiao, Hui; Rykunov, Dmitry; Casadevall, Arturo

2008-01-01

Introduction: There is a lot of interest towards creating therapies and vaccines for Bacillus anthracis, a bacterium which causes anthrax in humans and which spores can be made into potent biological weapons. Systemic injection of lethal factor (LF), edema factor (EF) and protective antigen (PA) in mice produces toxicity, and this protocol is commonly used to investigate the efficacy of specific antibodies in passive protection and vaccine studies. Availability of toxins labeled with imageable radioisotopes would allow to demonstrate their tissue distribution after intravenous injection at toxin concentration that are below pharmacologically significant to avoid masking by toxic effects. Methods: LF, EF and PA were radiolabeled with 188 Re and 99m Tc, and their performance in vitro was evaluated by macrophages and Chinese hamster ovary cells toxicity assays and by binding to macrophages. Scintigraphic imaging and biodistribution of intravenously (IV) injected 99m Tc-and 123 I-labeled toxins was performed in BALB/c mice. Results: Radiolabeled toxins preserved their biological activity. Scatchard-type analysis of the binding of radiolabeled PA to the J774.16 macrophage-like cells revealed 6.6x10 4 binding sites per cell with a dissociation constant of 6.7 nM. Comparative scintigraphic imaging of mice injected intravenously with either 99m Tc-or 123 I-labeled PA, EF and LF toxins demonstrated similar biodistribution patterns with early localization of radioactivity in the liver, spleen, intestines and excretion through kidneys. The finding of renal excretion shortly after IV injection strongly suggests that toxins are rapidly degraded which could contribute to the variability of mouse toxigenic assays. Biodistribution studies confirmed that all three toxins concentrated in the liver and the presence of high levels of radioactivity again implied rapid degradation in vivo. Conclusions: The availability of 188 Re and 99m Tc-labeled PA, LF and EF toxins allowed us to

Use of an anti-platelet monoclonal antibody F (ab')2 fragment for imaging thrombus

International Nuclear Information System (INIS)

Loutfi, I.; Stuttle, A.W.J.; Peters, A.M.; George, P.; Lavender, J.P.; Lumley, P.

1990-01-01

Ten patients with suspected thrombus have been studied using 111 In-labelled F (ab')2 fragments of P256, a monoclonal antibody which recognizes an epitope on the platelet membrane glycoprotein IIb/IIIa complex. The F (ab')2 fragment was radiolabelled with 111 In via diethylenetri-aminepentamacetic acid to give a specific activity of up to 190 MBq (5mCi) mg - 1 without impairment of immunoreactivity. In vitro platelet aggregation studies showed that the F (ab')2 fragment caused less platelet aggregation than the whole antibody on a molar ratio and was without significant effect upon the sensitivity of platelets to a range of aggregating agents. Platalets were labelled in ten patients by intravenous injection of approximately 100 μg P256 F (ab')2. Of the ten patients studies, six showed localization of activity consistent with platelet accumulation. Localization was clearly seen when associated with thrombus of the lower limbs (three patients: deep vein thrombosis; one patient: aortofemoral graft), and was apparent although less marked in two other cases, one of aortic aneurysm and one of carotid stenosis. Use of radiolabelled P256 F (ab')2 offers a means of non-invasive detection of thrombus which, from in vitro studies, would appear to have less direct effect of platelet behaviour than the whole antibody. (author). 9 refs. 8 figs. 1 tab

In vitro incorporation of radiolabeled cholesteryl esters into high and low density lipoproteins

International Nuclear Information System (INIS)

Terpstra, A.H.; Nicolosi, R.J.; Herbert, P.N.

1989-01-01

We have developed and validated a method for in vitro incorporation of radiolabeled cholesteryl esters into low density (LDL) and high density lipoproteins (HDL). Radiolabeled cholesteryl esters dissolved in absolute ethanol were mixed with LDL or HDL in the presence of lipoprotein-deficient serum (LPDS) as a source of core lipid transfer activity. The efficiency of incorporation was dependent on: (a) the core lipid transfer activity and quantity of LPDS, (b) the mass of added radiolabeled cholesteryl esters, (c) the length of incubation, and (d) the amount of acceptor lipoprotein cholesterol. The tracer incorporation was documented by repeat density gradient ultracentrifugation, agarose gel electrophoresis, and precipitation with heparin-MnCl2. The radiolabeling conditions did not affect the following properties of the lipoproteins: (1) chemical composition, (2) electrophoretic mobility on agarose gels, (3) hydrated density, (4) distribution of apoproteins on SDS gels, (5) plasma clearance rates, and (6) immunoprecipitability of HDL apoproteins A-I and A-II. Rat HDL containing radiolabeled cholesteryl esters incorporated in vitro had plasma disappearance rates identical to HDL radiolabeled in vivo

A three-layer immunoradiometric assay for antibodies in different immunoglobulin classes and its application to the detection of chicken thyroglobulin autoantibodies and of antibodies to sheep erythrocytes

International Nuclear Information System (INIS)

Carvalho, L.C.P. de; Roitt, I.M.; Wick, G.

1980-01-01

A versatile solid-phase assay for detection of antibodies in different immunoglobulin classes is described. The assay has been applied to: (1) the detection of IgG and IgM antithyroglobulin autoantibodies in chickens with spontaneous autoimmune thyroiditis, and (2) the detection of anti-sheep cell antibodies in normal chickens. Thyroglobulin-coated plastic tubes or formaldehyde-fixed sheep erythrocytes were used as the solid phase. Antisera were added in succession to the solid-phase antigen so as to form 3 antibody layers: (1) chicken antibody against the solid-phase antigen; (2) heavy-chain-specific rabbit anti-chicken immunoglobulin; and (3) 125 I-labelled goat anti-rabbit immunoglobulin. The assay is suitable for routine determinations on large numbers of samples; its sensitivity enables small volumes of serum to be tested and allows considerable economy in the use of valuable class-specific antisera. The radiolabelled reagent can be readily applied to other assays employing rabbit antisera. (Auth.)

DIRECT AND INDIRECT FLUORESCENT-ANTIBODY TECHNIQUES FOR THE PSITTACOSIS-LYMPHOGRANULOMA VENEREUM-TRACHOMA GROUP OF AGENTS1

Science.gov (United States)

Ross, Martin R.; Borman, Earle K.

1963-01-01

Ross, Martin R. (Connecticut State Department of Health, Hartford) and Earle K. Borman. Direct and indirect fluorescent-antibody techniques for the psittacosis-lymphogranuloma venereum-trachoma group of agents. J. Bacteriol. 85:851–858. 1963.—Direct and indirect fluorescent-antibody (FA) techniques were developed for the detection of group antigen in infected tissue cultures and the titration of group antibody in human antiserum. The growth of the agent of meningopneumonitis (MP) in mouse embryo lung cell monolayers was followed by infectivity and complement-fixing (CF) antigen titrations, and cytological examination of FA stained cultures. Although infectivity and CF antigen reached a peak at 2 days and remained constant for an additional 3 days, only cells tested 2 to 3 days after infection were suitable for FA staining with labeled anti-MP serum because of excessive artifacts in the older cultures. Fluorescein isothiocyanate-labeled rooster and guinea pig anti-MP serums and human antipsittacosis serums were titrated in direct FA and hemagglutination-inhibition (HI) tests. The rooster conjugate showed brighter staining and higher antibody titers than the guinea pig or human conjugates and was more effective in detecting minimal amounts of virus antigen. FA staining reactions with 1 and 2 units of labeled rooster serum were inhibited by unlabeled rooster serum but clear-cut inhibition with human antipsittacosis serum could not be demonstrated. The indirect FA technique was successfully used for the titration of group antibody in human serum. A comparison of the indirect FA, HI, and CF tests showed the indirect FA technique to be intermediate in sensitivity between the HI and CF tests. None of the three tests showed significant cross reactions with human serums reactive for influenza A and B; parainfluenza 1, 2, and 3; respiratory syncytial virus; Q fever; or the primary atypical pneumonia agent. PMID:14044954

In vitro and in vivo properties of human/mouse chimeric monoclonal antibody specific for common acute lymphocytic leukemia antigen

International Nuclear Information System (INIS)

Saga, T.; Endo, K.; Koizumi, M.; Kawamura, Y.; Watanabe, Y.; Konishi, J.; Ueda, R.; Nishimura, Y.; Yokoyama, M.; Watanabe, T.

1990-01-01

A human/mouse chimeric monoclonal antibody specific for a common acute lymphocytic leukemia antigen was efficiently obtained by ligating human heavy-chain enhancer element to the chimeric heavy- and light-chain genes. Cell binding and competitive inhibition assays of both radioiodine and indium-111- (111In) labeled chimeric antibodies demonstrated in vitro immunoreactivity identical with that of the parental murine monoclonal antibodies. The biodistribution of the radiolabeled chimeric antibody in tumor-bearing nude mice was similar to that of the parental murine antibody. Tumor accumulation of radioiodinated parental and chimeric antibodies was lower than that of 111 In-labeled antibodies, probably because of dehalogenation of the radioiodinated antibodies. Indium-111-labeled chimeric antibody clearly visualized xenografted tumor. These results suggest that a human/mouse chimeric antibody can be labeled with 111 In and radioiodine without the loss of its immunoreactivity, and that chimeric antibody localizes in vivo in the same way as the parental murine antibody

Localization of radioiodinated antibody to alpha-fetoprotein in rats with transplanted hepatocellular carcinoma

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Koji, T; Ishii, N; Kono, K [Nagasaki Univ. (Japan)

1980-11-01

The specific localization of radiolabeled antibody to AFP was investigated in rats bearing subcutaneous transplants of AH-7974 ascites hepatoma. Total body scintigrams 48 to 168 hours after injection of /sup 125/I-anti rat AFP horse antibody showed remarkable localization of radioactivity on the tumors, as a control, a faint outline of tumor was observed by /sup 125/I-normal horse IgG. The tumor/blood radioactivity ratio in the antibody group exceeded 1.0 and was approximately four times higher than that in the control group 7 days after injection, and suggested an active accumulation of radioactive antibody in the tumor tissue. In the subcellular distribution of radioactivity in the tumor tissue, about 30 to 60% of the total radioactivity were found in a fraction of the cell membrane plus nucleus. Furthermore autoradiograms of the fixed tissue sections in the antibody group revealed the specific localization of the radioactivity on the tumor cell surface as black grains.

Technical Report (Final): Development of Solid State Reagents for Preparing Radiolabeled Imaging Agents

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Kabalka, George W

2011-05-20

The goal of this research was on the development of new, rapid, and efficient synthetic methods for incorporating short-lived radionuclides into agents of use in measuring dynamic processes. The initial project period (Year 1) was focused on the preparation of stable, solid state precursors that could be used to efficiently incorporate short-lived radioisotopes into small molecules of use in biological applications (environmental, plant, and animal). The investigation included development and evaluation of new methods for preparing carbon-carbon and carbon-halogen bonds for use in constructing the substrates to be radiolabeled. The second phase (Year 2) was focused on developing isotope incorporation techniques using the stable, boronated polymeric precursors. The final phase (Year 3), was focused on the preparation of specific radiolabeled agents and evaluation of their biodistribution using micro-PET and micro-SPECT. In addition, we began the development of a new series of polymeric borane reagents based on polyethylene glycol backbones.

Immunoscintigraphy of human tumors transplanted in nude mice with radiolabeled anti-ras p21 monoclonal antibodies

International Nuclear Information System (INIS)

Katoh, Y.; Nakata, K.; Kohno, K.; Shima, M.; Satoh, A.; Kusumoto, Y.; Ishii, N.; Kohji, T.; Shiku, H.; Nagataki, S.

1990-01-01

Anti-ras p21 monoclonal antibody (RASK-3) was used for immunoscintigraphy of human cancer cell lines in nude mice. Iodine-125-labeled RASK-3 was injected into nude mice with either human colon cancers (FCC-1 or BM-314) or lung cancer (KNS-62). Clear images were obtained in all three cancers 7 days after the injection of antibody. No localization of 125 I-labeled control monoclonal antibody was observed. The ratio of tissue/blood radioactivity and % ID/g in the tumor were significantly higher than other organs by Day 8. The specific localization index examined by 131 I-RASK-3 and 125 I-control monoclonal antibody was also higher in the tumor than in other tissues. In the in vitro study, binding of RASK-3 to tumor cells increased significantly by treatment of cells with either lysolecithin or periodate-lysine-paraformaldehyde, which confirmed the intracellular localization of ras p21. The mechanism by which anti-ras p21 antibodies accumulate in tumor sites could be the necrotic changes in tumor cells or changes in membrane permeability of non-necrotic cells. These results provide a strong rationale for the utilization of ras p21 as a target antigen in the imaging of a variety of human cancers

AL amyloid imaging and therapy with a monoclonal antibody to a cryptic epitope on amyloid fibrils.

Directory of Open Access Journals (Sweden)

Jonathan S Wall

Full Text Available The monoclonal antibody 2A4 binds an epitope derived from a cleavage site of serum amyloid protein A (sAA containing a -Glu-Asp- amino acid pairing. In addition to its reactivity with sAA amyloid deposits, the antibody was also found to bind amyloid fibrils composed of immunoglobulin light chains. The antibody binds to synthetic fibrils and human light chain (AL amyloid extracts with high affinity even in the presence of soluble light chain proteins. Immunohistochemistry with biotinylated 2A4 demonstrated positive reaction with ALκ and ALλ human amyloid deposits in various organs. Surface plasmon resonance analyses using synthetic AL fibrils as a substrate revealed that 2A4 bound with a K(D of ∼10 nM. Binding was inhibited in the presence of the -Glu-Asp- containing immunogen peptide. Radiolabeled 2A4 specifically localized with human AL amyloid extracts implanted in mice (amyloidomas as evidenced by single photon emission (SPECT imaging. Furthermore, co-localization of the radiolabeled mAb with amyloid was shown in biodistribution and micro-autoradiography studies. Treatment with 2A4 expedited regression of ALκ amyloidomas in mice, likely mediated by the action of macrophages and neutrophils, relative to animals that received a control antibody. These data indicate that the 2A4 mAb might be of interest for potential imaging and immunotherapy in patients with AL amyloidosis.

Eleventh international symposium on radiopharmaceutical chemistry

International Nuclear Information System (INIS)

1995-01-01

This document contains abstracts of papers which were presented at the Eleventh International Symposium on Radiopharmaceutical Chemistry. Sessions included: radiopharmaceuticals for the dopaminergic system, strategies for the production and use of labelled reactive small molecules, radiopharmaceuticals for measuring metabolism, radiopharmaceuticals for the serotonin and sigma receptor systems, labelled probes for molecular biology applications, radiopharmaceuticals for receptor systems, radiopharmaceuticals utilizing coordination chemistry, radiolabelled antibodies, radiolabelling methods for small molecules, analytical techniques in radiopharmaceutical chemistry, and analytical techniques in radiopharmaceutical chemistry

Eleventh international symposium on radiopharmaceutical chemistry

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

This document contains abstracts of papers which were presented at the Eleventh International Symposium on Radiopharmaceutical Chemistry. Sessions included: radiopharmaceuticals for the dopaminergic system, strategies for the production and use of labelled reactive small molecules, radiopharmaceuticals for measuring metabolism, radiopharmaceuticals for the serotonin and sigma receptor systems, labelled probes for molecular biology applications, radiopharmaceuticals for receptor systems, radiopharmaceuticals utilizing coordination chemistry, radiolabelled antibodies, radiolabelling methods for small molecules, analytical techniques in radiopharmaceutical chemistry, and analytical techniques in radiopharmaceutical chemistry.

A radiolabel release microassay for phagocytic killing of Candida albicans

International Nuclear Information System (INIS)

Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P.; Puccetti, P.

1982-01-01

The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans. (Auth.)

TU-F-12A-01: Quantitative Non-Linear Compartment Modeling of 89Zr- and 124I- Labeled J591 Monoclonal Antibody Kinetics Using Serial Non-Invasive Positron Emission Tomography Imaging in a Pre-Clinical Human Prostate Cancer Mouse Model

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Fung, EK; Cheal, SM; Chalasani, S; Fareedy, SB; Punzalan, B; Humm, JL; Osborne, JR; Larson, SM; Zanzonico, PB [Memorial Sloan Kettering Cancer Center, New York, NY (United States); Otto, B; Bander, NH [Weill Cornell Medical College, New York, NY (United States)

2014-06-15

Purpose: To examine the binding kinetics of human IgG monoclonal antibody J591 which targets prostate-specific membrane antigen (PSMA) in a pre-clinical mouse cancer model using quantitative PET compartmental analysis of two radiolabeled variants. Methods: PSMA is expressed in normal human prostate, and becomes highly upregulated in prostate cancer, making it a promising therapeutic target. Two forms of J591, radiolabeled with either {sup 89}Zr or {sup 124}I, were prepared. {sup 89}Zr is a radiometal that becomes trapped in the cell upon internalization by the antigen-antibody complex, while radioiodine leaves the cell. Mice with prostate cancer xenografts underwent non-invasive serial imaging on a Focus 120 microPET up to 144 hours post-injection of J591. A non-linear compartmental model describing the binding and internalization of antibody in tumor xenograft was developed and applied to the PET-derived time-activity curves. The antibody-antigen association rate constant (ka), total amount of antigen per gram tumor (Ag-total), internalization rate of antibody-antigen complex, and efflux rate of radioisotope from tumor were fitted using the model. The surface-bound and the internalized activity were also estimated. Results: Values for ka, Ag-total, and internalization rate were found to be similar regardless of radiolabel payload used. The efflux rate, however, was ∼ 9-fold higher for {sup 124}I-J591 than for {sup 89}Zr-J591. Time-dependent surface-bound and internalized radiotracer activity were similar for both radiolabels at early times post-injection, but clearly differed beyond 24 hours. Conclusion: Binding and internalization of J591 to PSMA-expressing tumor xenografts were similar when radiolabeled with either {sup 89}Zr or {sup 124}I payload. The difference in efflux of radioactivity from tumor may be attributable to differential biological fate intracellularly of the radioisotopes. This has great significance for radioimmunotherapy and antibody

Detection of deep venous thrombosis with indium 111-labelled monoclonal antibody against tissue plasminogen activator

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Tromholt, N.; Hesse, B. (Hilleroed County Hospital (Denmark). Dept. of Clinical Physiology); Folkenborg, O. (Isotope-Pharmcy, Broenshoej (Denmark)); Selmer, J. (Novo Industri A/S, Bagsvaerd (Denmark)); Nielsen, N.T. (Hilleroed County Hospital (Denmark). Dept. of Radiology)

1991-05-01

The administration of a radiolabelled monoclonal antibody against tissue plasminogen activator allows detection of areas with increased fibrinolytic activity, i.e. those with an active thrombotic lesion. Eight patients with phlebographically verified deep venous thrombosis were examined. At the time of immunoscintigraphy study they were examined receiving anticoagulant therapy. Some 75-85 MBq {sup 111}In-labelled antibody were injected, and scintigrams were obtained after 30 min and after 24 h. The precise site of the thrombus could not be visualized after 30 min due to high background activity, whereas after 24 h it was detectable in all patients. The thrombus/background ratios achieved are twice as high as those observed in a human antifibrin antibody study. These preliminary data suggest a high sensitivity of our PA-specific antibody for the detection of active deep venous thrombosis in man, and our antibody seems to offer theoretical advantages over both platelet and fibrin-specific antibodies. (orig.).

Detection of deep venous thrombosis with indium 111-labelled monoclonal antibody against tissue plasminogen activator

International Nuclear Information System (INIS)

Tromholt, N.; Hesse, B.; Selmer, J.; Nielsen, N.T.

1991-01-01

The administration of a radiolabelled monoclonal antibody against tissue plasminogen activator allows detection of areas with increased fibrinolytic activity, i.e. those with an active thrombotic lesion. Eight patients with phlebographically verified deep venous thrombosis were examined. At the time of immunoscintigraphy study they were examined receiving anticoagulant therapy. Some 75-85 MBq 111 In-labelled antibody were injected, and scintigrams were obtained after 30 min and after 24 h. The precise site of the thrombus could not be visualized after 30 min due to high background activity, whereas after 24 h it was detectable in all patients. The thrombus/background ratios achieved are twice as high as those observed in a human antifibrin antibody study. These preliminary data suggest a high sensitivity of our PA-specific antibody for the detection of active deep venous thrombosis in man, and our antibody seems to offer theoretical advantages over both platelet and fibrin-specific antibodies. (orig.)

Comparative study between phenol and imidazole derivatives in radiolabeling of some steroid hormones

International Nuclear Information System (INIS)

Sallam, Kh.M.

2010-01-01

A phenol or imidazole ring is rarely present in steroid hormones, So, the molecule of steroid hormone requires chemical modification by addition of an iodinable residue like phenol or imedazole. So that the comparative study between phenol derivatives, include tyrosine methyl ester (TME) and tyramine, and imidazole derivatives, like histamine and histedine methyl ester (HME), for radiolabeling of some steroid hormones include estradiol and testosterone is the aim of the present study. The conjugation step was carried using mixed anhydride method and followed by radioiodination using iodogen as an oxidizing agent. Purification step was carried out using high performance liquid chromatography (HPLC). Optimization and validation of the tracer were carried out. Immunoreactivity of the all obtained tracers was check by using specific polyclonal antibodies. The results indicated that imidazols derivatives are more suitable from immunoreactivity view and storage period.

Radiometallating antibodies and biologically active peptides

International Nuclear Information System (INIS)

Mercer-Smith, J.A.; Roberts, J.C.; Lewis, D.; Newmyer, S.L.; Schulte, L.D.; Burns, T.P.; Mixon, P.L.; Jeffery, A.L.; Schreyer, S.A.; Cole, D.A.; Figard, S.D.; Lennon, V.A.; Hayashi, M.; Lavallee, D.K.

1990-01-01

We have developed methods to radiolabel large molecules, using porphyrins as bifunctional chelating agents for radiometals. The porphyrins are substituted with an N-benzyl group to activate them for radiometallation under mild reaction conditions. Porphyrins that have on functional group for covalent attachment to other molecules cannot cause crosslinking. We have examined the labeling chemistry for antibodies, and we have also developed methods to label smaller biologically active molecules, such as autoantigenic peptides. The autoantigenic peptides, fragments of the acetylcholine receptor, are under investigation for myasthenia gravis research. The methods of covalent attachment of these bifunctional chelating agents to large molecules and the radiometallation chemistry will be discussed

Detection of inflammatory lesions with radiolabelled immunoglobulins

International Nuclear Information System (INIS)

Blok, D.; Rijksuniversiteit Leiden; Ogtrop, M. van; Arndt, J.W.; Camps, J.A.J.; Feitsma, R.I.J.; Pauwels, E.K.J.

1990-01-01

Previous reports on the use of radiolabelled immunoglobulins led us to undertake a pilot experiment in an animal model to investigate the potentials sodium pertechnate Tc 99m-immunoglobulin scintigraphy in the detection of infectious foci. Mice infected in one leg with staphylococcus infection in were injected with sodium pertechnote Tc 99m-immunoglobulin, albumin aggregated technetium Tc 99m or gallium citrate Ga 67. The results obtained by scintigraphy suggested a specific accumulation of radiolabelled immunoglobulin at the site of infection. Visualization of the infection and the image quality, especially the 6- and 24-h images, were clearly enhanced after the use of immunoglobulin preparations as compared with those labelled with gallium. (orig.)

Improved radioimmunotherapy of hematologic malignancies. Final technical report

International Nuclear Information System (INIS)

Press, O.W.

1996-01-01

Experiments were performed to study the rates of endocytosis, intracellular routing, and metabolic degradation of radiolabeled monoclonal antibodies targeting tumor-associated antigens on human leukemia and lymphoma cells. An attempt was made to examine in vivo the effects of lysosomotropic amines and thioamides on the retention of radiolabeled monoclonal antibodies by tumor cells. Experiments also examined the impact of newer radioiodination techniques on the metabolic degradation of radioiodinated antibodies, and on the radioimmunoscintigraphy and radioimmunotherapy of neoplasms. The endocytosis, intracellular routing, and degradation of radioimmunoconjugates prepared with I-131, In-111, and Y-90 were compared. The utility of radioimmunoconjugates targeting oncogene products for the radioimmunotherapy and radioimmunoscintigraphy of cancer was investigated

Anti-idiotypic antibodies that protect cells against the action of diphtheria toxin

International Nuclear Information System (INIS)

Rolf, J.M.; Gaudin, H.M.; Tirrell, S.M.; MacDonald, A.B.; Eidels, L.

1989-01-01

An anti-idiotypic serum prepared against the combining site (idiotype) of specific anti-diphtheria toxoid antibodies was characterized with respect to its interaction with highly diphtheria toxin-sensitive Vero cells. Although the anti-idiotypic serum protected Vero cells against the cytotoxic action of diphtheria toxin, it did not prevent the binding of 125 I-labeled diphtheria toxin to the cells but did inhibit the internalization and degradation of 125 I-labeled toxin. This anti-idiotypic serum immunoprecipitated a cell-surface protein from radiolabeled Vero cells with an apparent Mr of approximately 15,000. These results are consistent with the hypothesis that the anti-idiotypic serum contains antibodies that carry an internal image of an internalization site on the toxin and that a cell-surface protein involved in toxin internalization possesses a complementary site recognized by both the toxin and the anti-idiotypic antibodies

The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer.

Science.gov (United States)

Navarro-Pelayo Láinez, M M; Rodríguez-Fernández, A; Gómez-Río, M; Vázquez-Alonso, F; Cózar-Olmo, J M; Llamas-Elvira, J M

2014-11-01

prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer. a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer» and «Choline-PET/CT». Other search terms were «Biochemical failure» and/or «Staging» and/or «PSA kinetics». English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included. according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

Detection of early atherosclerosis with radiolabeled monocyte chemoattractant protein-1 in prediabeteic Zucker rats

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Blankenberg, F.G. [Div. of Pediatric Radiology, Stanford, CA (United States); Wen, P.; Dai, M.; Zhu, D.; Panchal, S.N.; Valantine, H.A. [Division of Cardiovascular Medicine, Department of Medicine, Stanford, California (United States); Tait, J.F. [Dept. of Laboratory Medicine, Univ. of Washington, Seattle (United States); Post, A.M.; Strauss, H.W. [Div. of Nuclear Medicine, Stanford Univ., CA (United States)

2001-12-01

Background: Migration of monocytes into the arterial wall is an early finding of atherosclerosis. Monocytes are attracted to sites of vascular endothelial cell injury, the initiating event in the development of atheromatous disease, by a chemokine known as monocyte chemoattractant protein-1 (MCP-1). Injured vascular endothelial and smooth muscle cells selectively secrete MCP-1. Objective: This study was performed to determine if radiolabeled MCP-1 would co-localize at sites of monocyte/macrophage concentration in an experimental model of transplant-induced vasculopathy in diabetic animals. Materials and methods: Hearts from 3-month-old male Zucker rats, heterozygote (Lean) or homozygote (Fat) for the diabetes-associated gene fa, were transplanted into the abdomens of genetically matched recipients. Lean and Fat animals were then fed normal or high-fat diets for 90 days. Results: At 90 days significant increases (P < 0.013) of MCP-1 graft uptake were seen at imaging and confirmed on scintillation gamma well counting studies in Lean (n = 5) and Fat (n = 12) animals, regardless of diet, 400 % and 40 %, above control values, respectively. MCP-1 uptake of native and grafted hearts correlated with increased numbers of perivascular macrophages (P < 0.02), as seen by immunostaining with an antibody specific for macrophages (ED 2). Conclusion: Radiolabeled MCP-1 can detect abnormally increased numbers of perivascular mononuclear cells in native and grafted hearts in prediabetic rats. MCP-1 may be useful in the screening of diabetic children for early atherosclerotic disease. (orig.)

Detection of early atherosclerosis with radiolabeled monocyte chemoattractant protein-1 in prediabeteic Zucker rats

International Nuclear Information System (INIS)

Blankenberg, F.G.; Wen, P.; Dai, M.; Zhu, D.; Panchal, S.N.; Valantine, H.A.; Tait, J.F.; Post, A.M.; Strauss, H.W.

2001-01-01

Background: Migration of monocytes into the arterial wall is an early finding of atherosclerosis. Monocytes are attracted to sites of vascular endothelial cell injury, the initiating event in the development of atheromatous disease, by a chemokine known as monocyte chemoattractant protein-1 (MCP-1). Injured vascular endothelial and smooth muscle cells selectively secrete MCP-1. Objective: This study was performed to determine if radiolabeled MCP-1 would co-localize at sites of monocyte/macrophage concentration in an experimental model of transplant-induced vasculopathy in diabetic animals. Materials and methods: Hearts from 3-month-old male Zucker rats, heterozygote (Lean) or homozygote (Fat) for the diabetes-associated gene fa, were transplanted into the abdomens of genetically matched recipients. Lean and Fat animals were then fed normal or high-fat diets for 90 days. Results: At 90 days significant increases (P < 0.013) of MCP-1 graft uptake were seen at imaging and confirmed on scintillation gamma well counting studies in Lean (n = 5) and Fat (n = 12) animals, regardless of diet, 400 % and 40 %, above control values, respectively. MCP-1 uptake of native and grafted hearts correlated with increased numbers of perivascular macrophages (P < 0.02), as seen by immunostaining with an antibody specific for macrophages (ED 2). Conclusion: Radiolabeled MCP-1 can detect abnormally increased numbers of perivascular mononuclear cells in native and grafted hearts in prediabetic rats. MCP-1 may be useful in the screening of diabetic children for early atherosclerotic disease. (orig.)

Radiolabeled Humanized Anti-CD3 Monoclonal Antibody Visilizumab for Imaging Human T-Lymphocytes

NARCIS (Netherlands)

Malviya, Gaurav; D'Alessandria, Calogero; Bonanno, Elena; Vexler, Vladimir; Massari, Roberto; Trotta, Carlo; Scopinaro, Francesco; Dierckx, Rudi; Signore, Alberto

2009-01-01

Visilizumab is an IgG(2) humanized monoclonal antibody (mAb) characterized by non-Fc gamma R binding and specific to the CD3 antigen, expressed on more than 95% of circulating resting T-lymphocytes and on activated T-lymphocytes homing in inflamed tissues. We hypothesized that the use of a

Radiopharmaceutical development of radiolabelled peptides

Energy Technology Data Exchange (ETDEWEB)

Fani, Melpomeni; Maecke, Helmut R. [University Hospital Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

2012-02-15

Receptor targeting with radiolabelled peptides has become very important in nuclear medicine and oncology in the past few years. The overexpression of many peptide receptors in numerous cancers, compared to their relatively low density in physiological organs, represents the molecular basis for in vivo imaging and targeted radionuclide therapy with radiolabelled peptide-based probes. The prototypes are analogs of somatostatin which are routinely used in the clinic. More recent developments include somatostatin analogs with a broader receptor subtype profile or with antagonistic properties. Many other peptide families such as bombesin, cholecystokinin/gastrin, glucagon-like peptide-1 (GLP-1)/exendin, arginine-glycine-aspartic acid (RGD) etc. have been explored during the last few years and quite a number of potential radiolabelled probes have been derived from them. On the other hand, a variety of strategies and optimized protocols for efficient labelling of peptides with clinically relevant radionuclides such as {sup 99m}Tc, M{sup 3+} radiometals ({sup 111}In, {sup 86/90}Y, {sup 177}Lu, {sup 67/68}Ga), {sup 64/67}Cu, {sup 18}F or radioisotopes of iodine have been developed. The labelling approaches include direct labelling, the use of bifunctional chelators or prosthetic groups. The choice of the labelling approach is driven by the nature and the chemical properties of the radionuclide. Additionally, chemical strategies, including modification of the amino acid sequence and introduction of linkers/spacers with different characteristics, have been explored for the improvement of the overall performance of the radiopeptides, e.g. metabolic stability and pharmacokinetics. Herein, we discuss the development of peptides as radiopharmaceuticals starting from the choice of the labelling method and the conditions to the design and optimization of the peptide probe, as well as some recent developments, focusing on a selected list of peptide families, including somatostatin

Imaging with radiolabelled anti-membrane type 1 matrix metalloproteinase (MT1-MMP) antibody: potentials for characterizing atherosclerotic plaques

Energy Technology Data Exchange (ETDEWEB)

Kuge, Yuji [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Takai, Nozomi; Ogawa, Yuki; Temma, Takashi; Nishigori, Kantaro; Ishino, Seigo; Kamihashi, Junko; Saji, Hideo [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Zhao, Yan [Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kiyono, Yasushi [Kyoto University, Department of Patho-functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); University of Fukui, Biomedical Imaging Research Center, Fukui (Japan); Shiomi, Masashi [Kobe University Graduate School of Medicine, Institute for Experimental Animals, Kobe (Japan)

2010-11-15

Membrane type 1 matrix metalloproteinase (MT1-MMP) activates pro-MMP-2 and pro-MMP-13 to their active forms and plays important roles in the destabilization of atherosclerotic plaques. This study sought to determine the usefulness of {sup 99m}Tc-labelled monoclonal antibody (mAb), recognizing MT1-MMP, for imaging atherosclerosis in a rabbit model (WHHLMI rabbits). Anti-MT1-MMP monoclonal IgG{sub 3} and negative control IgG{sub 3} were radiolabelled with {sup 99m}Tc after derivatization with 6-hydrazinonicotinic acid (HYNIC) to yield {sup 99m}Tc-MT1-MMP mAb and {sup 99m}Tc-IgG{sub 3}, respectively. WHHLMI and control rabbits were injected with these radio-probes. The aorta was removed and radioactivity was measured at 24 h after the injection. Autoradiography and histological studies were performed. {sup 99m}Tc-MT1-MMP mAb accumulation in WHHLMI rabbit aortas was 5.4-fold higher than that of control rabbits. Regional {sup 99m}Tc-MT1-MMP mAb accumulation was positively correlated with MT1-MMP expression (r = 0.59, p < 0.0001), while {sup 99m}Tc-IgG{sub 3} accumulation was independent of MT1-MMP expression (r = 0.03, p = NS). The highest {sup 99m}Tc-MT1-MMP mAb accumulation was found in atheromatous lesions (4.8 {+-} 1.9, %ID x BW/mm{sup 2} x 10{sup 2}), followed in decreasing order by fibroatheromatous (1.8 {+-} 1.3), collagen-rich (1.6 {+-} 1.0) and neointimal lesions (1.5 {+-} 1.5). In contrast, {sup 99m}Tc-IgG{sub 3} accumulation was almost independent of the histological grade of lesions. Higher {sup 99m}Tc-MT1-MMP mAb accumulation in grade IV atheroma was shown in comparison with neointimal lesions or other more stable lesions. Nuclear imaging with {sup 99m}Tc-MT1-MMP mAb, in combination with CT and MRI, could provide new diagnostic imaging capabilities for detecting vulnerable plaques, although further investigations to improve target to blood ratios are strongly required. (orig.)

Novel strategies for microdose studies using non-radiolabeled compounds.

Science.gov (United States)

Maeda, Kazuya; Sugiyama, Yuichi

2011-06-19

Microdose studies using non-radiolabeled compounds enable assessment of the clinical pharmacokinetics of drug candidates in humans without the need to synthesize radiolabeled compounds. We have demonstrated that the quantification limits of many drugs measured by LC-MS/MS are low enough to allow estimation of their pharmacokinetic parameters following administration of a microdose. Our previous microdose studies with LC-MS/MS demonstrated the linear pharmacokinetics of fexofenadine between microdoses and therapeutic doses. We also obtained time profiles of plasma concentrations of nicardipine and its multiple metabolites following administration of a microdose. A significant advantage of using non-radiolabeled compounds is the ability to perform cassette microdose studies. By administering multiple drug candidates to the same subject, we can select compounds with appropriate pharmacokinetic properties simultaneously. We can also clarify major factors dominating the pharmacokinetics of drug candidates by cocktail microdosing of the test compounds and probe substrates with or without specific inhibitors for enzymes/transporters. Copyright © 2011 Elsevier B.V. All rights reserved.

Localization of radiolabeled anti-DNA monoclonal antibodies in murine systemic lupus erythematosus (SLE)

International Nuclear Information System (INIS)

Wahl, R.; Hahn, B.; Ebling, F.

1984-01-01

The diagnosis of SLE can be extremely difficult. This multi-system disease is characterized by the deposition of DNA-anti-DNA antibody (Ab) complexes in many tissues, producing glomerulonephritis and systemic vasculitis. This study evaluates an IGG monoclonal (Mo) Ab directe3d against DNA (MrSSl) for potential radioimmunodiagnosis of SLE. Six 15 wk. old F-1 female hybrids of NZB+NZW mice (an animal SLE model that develops vasculitis and nephritis) were injected with 50 μCl of I-131 MrSSl and 15 μCl of I-125 isotype-matched control mouse myeloma (LPC-1) (non-reactive with DNA). Imaging and tissue distribution were studied. Two animals were also imaged using I-131 LPC Ab. Images at 2 and 9 days showed no clear differences in scan patterns using MrSSl or LPC-1 Ab. Tissue distribution studies at six days, however, showed a significantly higher accumulation of MrSSl in the kidneys vs. control Ab (2.7% vs. 1.8% of injected dose) (p < .04). Similarly, higher levels of MrSS were also seen in the spleen, liver and lungs (p < .03). Blood levels tended to be higher with the specific antibody as well. These differences were not apparent at 3 days post injection. The increased concentration of MrSSl present at 9 days in several organs may be secondary to MrSSl binding to DNA containing immune complexes present in diseased tissues. Blocked clearance by immune complexes or DNA, or differences in electrical charges of the antibodies could be contributing to the higher MrSSl levels seen. Images did not suggest deiodination as responsible. Further studies are necessary to determine if the amount of MrSSl retained by diseased animals is indicative of SLE disease activity

Assessment of radioactive residues arising from radiolabel instability in a multiple dose tissue distribution study in rats

International Nuclear Information System (INIS)

Slatter, J.G.; Sams, J.P.; Easter, J.A.

2003-01-01

Our study objectives were to quantitatively determine the effect of radiolabel instability on terminal phase radioactive tissue residues in a multiple dose tissue distribution study, to quantitatively compare tissue residue artifacts (non drug-related radioactivity) from two chemically-distinct radiolabel locations, and to conduct a definitive multiple dose tissue distribution study using the better of the two radiolabeled compounds. We compared the excretion and tissue distribution in rats of [ 14 C]linezolid, radiolabeled in two different locations, after 7 consecutive once daily [ 14 C] oral doses. The radiolabels were in the acetamide (two carbon) and oxazolidinone (isolated carbon) functional groups. Terminal phase tissue residue and excretion data were compared to data from rats dosed orally with [ 14 C]sodium acetate. Drug-related radioactivity was excreted rapidly over 24 h. After a single dose, the acetamide and oxazolidinone radiolabel sites both gave 3% of dose as exhaled 14 CO 2 . After 7 daily [ 14 C] oral doses, terminal phase radioactive tissue residues were higher from the acetamide radiolabel, relative to the oxazolidinone radiolabel, and were primarily not drug-related. In the definitive tissue distribution study, low concentrations of drug-related radioactivity in skin and thyroid were observed. We conclude that although small amounts of radiolabel instability do not significantly affect single dose tissue radioactivity C max and area under the curve (AUC), artifacts arising from radiolabel instability can prolong the apparent terminal phase half life and complicate study data interpretation. When possible, it is always preferable to use a completely stable radiolabel site. (author)

Assessment of radioactive residues arising from radiolabel instability in a multiple dose tissue distribution study in rats

Energy Technology Data Exchange (ETDEWEB)

Slatter, J.G. [Pharmacia Corp., Peapack, NJ (United States); Sams, J.P.; Easter, J.A. [Pharmacia Corp., Kalamazoo, MI (United States)] [and others

2003-05-01

Our study objectives were to quantitatively determine the effect of radiolabel instability on terminal phase radioactive tissue residues in a multiple dose tissue distribution study, to quantitatively compare tissue residue artifacts (non drug-related radioactivity) from two chemically-distinct radiolabel locations, and to conduct a definitive multiple dose tissue distribution study using the better of the two radiolabeled compounds. We compared the excretion and tissue distribution in rats of [{sup 14}C]linezolid, radiolabeled in two different locations, after 7 consecutive once daily [{sup 14}C] oral doses. The radiolabels were in the acetamide (two carbon) and oxazolidinone (isolated carbon) functional groups. Terminal phase tissue residue and excretion data were compared to data from rats dosed orally with [{sup 14}C]sodium acetate. Drug-related radioactivity was excreted rapidly over 24 h. After a single dose, the acetamide and oxazolidinone radiolabel sites both gave 3% of dose as exhaled {sup 14}CO{sub 2}. After 7 daily [{sup 14}C] oral doses, terminal phase radioactive tissue residues were higher from the acetamide radiolabel, relative to the oxazolidinone radiolabel, and were primarily not drug-related. In the definitive tissue distribution study, low concentrations of drug-related radioactivity in skin and thyroid were observed. We conclude that although small amounts of radiolabel instability do not significantly affect single dose tissue radioactivity C{sub max} and area under the curve (AUC), artifacts arising from radiolabel instability can prolong the apparent terminal phase half life and complicate study data interpretation. When possible, it is always preferable to use a completely stable radiolabel site. (author)

Partition of radiolabeled amino acids in detached wheat heads in culture

International Nuclear Information System (INIS)

Inwood, W.; Bernardin, J.

1990-01-01

The concentration of a particular amino acid supplied to a detached wheat head affected the ultimate distribution of that amino acid among the tissues of the head. Detached wheat heads (Triticum aestivum L. cv Cheyenne) were supplied with a pulse of [ 3 H]leucine in the culture medium and were chased with medium that contained glutamine as the sole nitrogen source. When the amount of radiolabel was held constant, an increasing concentration of unlabeled leucine in the pulse medium led to an increased partition of the radiolabel into the grain tissues of the head. When the concentration of unlabeled leucine was increased from zero to radiolabeled leucine was partitioned to endosperm tissue and twice as much to seedcoat tissues. An effect of amino acid concentration on radiolabel partition was also found for methionine and proline, but the effect was not as dramatic. These results suggest the existence of an amino acid transport system between the transpiration stream of the wheat head and the grain that exhibits cooperative kinetics or amino acid activation

Radioimmunoguided surgery using the monoclonal antibody B72.3 in colorectal tumors

International Nuclear Information System (INIS)

Sickle-Santanello, B.J.; O'Dwyer, P.J.; Mojzisik, C.

1987-01-01

The authors have developed a hand-held gamma-detecting probe (GDP) for intraoperative use that improves the sensitivity of external radioimmunodetection. Radiolabeled monoclonal antibody (MAb) B72.3 was injected in six patients with primary colorectal cancer and 31 patients with recurrent colorectal cancer an average of 16 days preoperatively. The GDP localized the MAb B72.3 in 83 percent of sites. The technique, known as a radioimmunoguided surgery (RIGS) system did not alter the surgical procedure in patients with primary colorectal cancer but did alter the approach in 26 percent (8/31) of patients with recurrent colorectal cancer. Two patients avoided unnecessary liver resections and two underwent extraabdominal approaches to document their disease. The RIGS system may influence the short-term morbidity and mortality of surgery for colorectal cancer. Larger series and longer follow-up are needed to determine whether the RIGS system confers a survival advantage to the patient with colorectal cancer

Comparative pharmacokinetics and biodistribution studies of 99mTc-annexin V produced by different radiolabeling methods

International Nuclear Information System (INIS)

Santos, Josefina da Silva; Pujatti, Priscilla Brunelli; Couto, Renata Martinussi; Mengatti, Jair; Araujo, Elaine Bortoleti de

2009-01-01

The use of radiolabeled annexin A5 (ANXA5) to detect cell death in vivo has increased in the last years. Several 99m Tc-labeling techniques were reported using different cores, such as [ 99m Tc=O] +3 , [ 99m Tc]HYNIC, [ 99m Tc≡N] +2 and [Tc(CO 3 )] +1 . The goal of the present work was to evaluate the influence of 99m Tc cores in the biological behavior of radiolabeled ANXA5 in Swiss mice using [ 99m Tc=O] +3 , [ 99m Tc]HYNIC cores. Ethylenedicysteine (EC) was applied to obtain [Tc=O] +3 core, N,N,N',N'-tetramethyl(succinimide) uranium tetrafluoroborate (TSTU) was employed to transfer the carboxyl group to their corresponding hydroxysuccinimide ester and HYNIC-ANXA5 was provided by National Cancer Institute-Frederick. ITLC-SG and HPLC analysis were applied to determine non-desirable products and the stability of preparations was evaluated after incubation at room temperature, 4 deg C and in human serum at 37 deg C. In vivo biodistribution and kinetics studies were performed after the intravenous injection of 99m Tc-HYNIC-ANXA5 and 99m Tc-EC-ANXA5 and pharmacokinetic parameters were calculated using Biexp software. ANXA5 was radiolabeled at room temperature with high yield (> 95%). The results of biodistribution in mice showed, as expected, higher renal uptake of 99m Tc-HYNICANXA5 and higher liver uptake of 99m Tc-EC-ANXA5. The percent injected activity per gram (% IA/g) in liver at 0.5 hours were 6.52 and 1.09 and in kidneys were 1.59 and 32.2 for 99m Tc-EC-ANXA5 and 99m Tc-HYNICANXA5, respectively. The results of radioactivity in blood showed that both HYNIC- and EC- radiolabeled ANXA5 presented fast blood clearance. In this study two 99m Tc-ANXA5 obtained from three different available radiolabeling methods presently were investigated. Each labeling method possesses unique advantages and disadvantages. (author)

Synthesis of 14C-radiolabelled Tilmicosin

International Nuclear Information System (INIS)

Crouse, G.D.; Terando, N.H.

1989-01-01

Tilmicosin was radiolabelled with carbon-14 on the 3,5-dimethylpiperidinyl sidechain as a requirement for animal metabolism studies. A new radiosynthesis of 3,5-dimethyl-piperidine was developed for this purpose. Incorporation into the desmycosin nucleus was accomplished by a reductive amination reaction. (author)

Localization of radioiodinated antibody to alpha-fetoprotein in rats with transplanted hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Koji, T; Ishii, N; Munehisa, T; Kusumoto, Y; Nakamura, S; Tamenishi, A [Nagasaki Univ. (Japan). School of Medicine; Kobayashi, K; Hara, A; Tsukada, Y; Nishi, S

1980-01-01

Total body scintigraphy, organ and subcellular distribution of radioactivity and autoradiography of tissue sections has been assessed in an animal model using radioiodinated horse antibody to rat alpha-fetoprotein (AFP). Rats bearing subcutaneous transplants of AH-7974 ascites hepatoma were injected with /sup 125/I-labeled anti-AFP and scintigraphed. Localization of radioactivity in the tumors was observed 48-168 h after injection. Scintigraphy using /sup 125/I-labeled F(ab')/sub 2/ fragment of the antibody gave approximately the same results as that with the intact anti-AFP antibody. /sup 125/I-labeled normal horse IgG was used as control. The tumor/blood radioactivity ratio after a week after injection was approximately four times higher in the antibody group than that in the control group. This ratio suggested an active accumulation of radioactive antibody in the tumor tissue. In its subcellular distribution, about 30 to 60% of the total radioactivity administered was found in a fraction of the cell membrane plus nucleus. The specific activity of this fraction increased in the antibody group with time over 10 days. In autoradiograms of the fixed tissue sections specific localization of the antibody was observed on the tumor cell surface. The specific uptake of radiolabeled antibody to AFP into AFP producing tumor cells was confirmed.

Negligible depletion solid-phase microextraction with radiolabeled analytes to study free concentrations and protein binding : an example with [3H]Estradiol

NARCIS (Netherlands)

Heringa, M.B.; Pastor, D.; Algra, J.; Vaes, W.H.J.; Hemmens, J.L.M.

2002-01-01

A new method is presented that enables sensitive measurement of free concentrations of radiolabeled ligands. Additionally, protein binding of radiochemicals in complex matrixes can be determined with this new technique that combines negligible depletion solid-phase microextraction (nd-SPME) with

Chemical radiolabeling of carboxyatractyloside by [14C]acetic anhydride

International Nuclear Information System (INIS)

Block, M.R.; Pougeois, R.; Vignais, P.V.

1980-01-01

The authors report the synthesis and biological properties of a radiolabeled derivative of CAT obtained with acetylation of the primary alcohol of CAT with radiolabeled acetic anhydride. They also investigate the question of mutual exclusion of CAT and BA for binding to the mitochondrial ADP/ATP carrier in double labeling experiments based on the use of [ 3 H]BA and [ 14 C]Ac-CAT. The results are consistent with the view that the ADP/ATP carrier possesses two separate interacting binding sites for AT (or CAT) and for BA. (Auth.)

Anti-idiotypic antibodies that protect cells against the action of diphtheria toxin

Energy Technology Data Exchange (ETDEWEB)

Rolf, J.M.; Gaudin, H.M.; Tirrell, S.M.; MacDonald, A.B.; Eidels, L.

1989-03-01

An anti-idiotypic serum prepared against the combining site (idiotype) of specific anti-diphtheria toxoid antibodies was characterized with respect to its interaction with highly diphtheria toxin-sensitive Vero cells. Although the anti-idiotypic serum protected Vero cells against the cytotoxic action of diphtheria toxin, it did not prevent the binding of /sup 125/I-labeled diphtheria toxin to the cells but did inhibit the internalization and degradation of /sup 125/I-labeled toxin. This anti-idiotypic serum immunoprecipitated a cell-surface protein from radiolabeled Vero cells with an apparent Mr of approximately 15,000. These results are consistent with the hypothesis that the anti-idiotypic serum contains antibodies that carry an internal image of an internalization site on the toxin and that a cell-surface protein involved in toxin internalization possesses a complementary site recognized by both the toxin and the anti-idiotypic antibodies.

Tumor affinity of radiolabeled peanut agglutinin compared with that of Ga-67 citrate in animal models

International Nuclear Information System (INIS)

Yokoyama, K.; Aburano, T.; Watanabe, N.; Kawabata, S.; Ishida, H.; Mukai, K.; Tonami, N.; Hisada, K.

1985-01-01

Peanut agglutinin (PNA) binds avidly to the immunodominant group of the tumor associated T antigen. The purpose of this study was to evaluate oncodiagnostic potential of radiolabeled PNA in animal models. PNA was labeled with I-125 or I-131 by Iodogen and also with In-111 by cyclic DTPA anhydride. The biological activity of PNA was examined by a hemaglutination titer with a photometer before and after labeling. Animal tumor models used were Lewis Lung Cancer(LLC), B-16 Melanotic Melanoma(MM), Yoshida Sarcoma(YS), Ehrlich Ascites Tumor(EAT and Hepatoma AH109A(HAH). Inflammatory tissue induced by turpentine oil was used as an abscess model. Serial scintigraphic images were obtained following IV injections of 100 μCi of I-131 or In-111-DTPA-PNA. The tumor affinity of Ga-67 citrate was studied to compare that of radiolabeled PNA. Tissue biodistribution was studied in EAT bearing mice. All of these tumor models except HAH were clearly visible by radiolabeled PNA without subtraction techniques. In the models of LLC and EAT, PNA showed the better accumulation into the tumor tissue than Ga-67 citrate. In YS and MM, PNA represented almost the same accumulation as Ga-67 citrate. The localization of PNA into abscess tissue wasn't found although Ga-67 citrate markedly accumulated into abscess tissue as well as tumor tissue. The clearance of PNA from tumor was slower than those from any other organs. Tumor to muscle ratio was 5.1 at 48hrs. and tumor to blood ratio increased with time to 2.3 at 96hrs. These results suggested that radiolabeled PNA may have a potential in the detection of tumor

An Efficient and Straightforward Method for Radiolabeling of Nanoparticles with {sup 64}Cu via Click Chemistry

Energy Technology Data Exchange (ETDEWEB)

Lee, Dong-Eun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Kwangmeyung [Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791 (Korea, Republic of); Park, Sang Hyun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Department of Radiobiotechnology and Applied Radioisotope Science, Korea University of Science and Technology, Deajeon 305-350 (Korea, Republic of)

2015-07-01

Recently, nanoparticles have received a great deal of interest in diagnosis and therapy applications. Since nanoparticles possess intrinsic features that are often required for a drug delivery system and diagnosis, they have potential to be used as platforms for integrating imaging and therapeutic functions, simultaneously. Intrinsic issues that are associated with theranostic nanoparticles, particularly in cancer treatment, include an efficient and straightforward radiolabeling method for understanding the in vivo biodistribution of nanoparticles to reach the tumor region, and monitoring therapeutic responses. Herein, we investigated a facile and highly efficient strategy to prepare radiolabeled nanoparticles with {sup 64}Cu via a strain-promoted azide, i.e., an alkyne cycloaddition strategy, which is often referred to as click chemistry. First, the azide (N3) group, which allows for the preparation of radiolabeled nanoparticles by copper-free click chemistry, was incorporated into glycol chitosan nanoparticles (CNPs). Second, the strained cyclooctyne derivative, dibenzyl cyclooctyne (DBCO) conjugated with a 1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid (DOTA) chelator, was synthesized for preparing the pre-radiolabeled alkyne complex with {sup 64}Cu radionuclide. Following incubation with the {sup 64}Cu-radiolabeled DBCO complex (DBCO-PEG4-Lys-DOTA-{sup 64}Cu with high specific activity, 18.5 GBq/μ mol), the azide-functionalized CNPs were radiolabeled successfully with {sup 64}Cu, with a high radiolabeling efficiency and a high radiolabeling yield (>98%). Importantly, the radiolabeling of CNPs by copper-free click chemistry was accomplished within 30 min, with great efficiency in aqueous conditions. After {sup 64}Cu-CNPs were intravenously administered to tumor-bearing mice, the real time, in vivo biodistribution and tumor-targeting ability of {sup 64}Cu-CNPs were quantitatively evaluated by micro-PET images of tumor-bearing mice. These results

Bone marrow dosimetry for monoclonal antibody therapy

International Nuclear Information System (INIS)

Bigler, R.E.; Zanzonico, P.B.; Leonard, R.

1986-01-01

Immunoglobulins must permeate through the basement membrane of capillaries in order to enter the extracellular space (ECS) of tissue. Since the process is quite slow, the blood plasma activity in various organs contributes considerably to the radiation dose of the dose-limiting tissues. In bone marrow the basement membrane is absent and the blood circulation is functionally open. Therefore, blood plasma and marrow ECS maintain equal concentrations of labeled immunoglobulins. A combination of factors including intravenous administration, slow absorption into most tissues, slow breakdown and elimination of labeled immunoglobulin, and rapid entry into bone marrow ECS as well as known radiosensitivity of marrow led the authors to expect this tissue would prove to be the primary tissue at risk for systemic monoclonal antibody therapy. They have developed and applied in a Phase I clinical study of 131 I labeled CEA antibody a procedure for estimation of radiation dose to red bone marrow. Serieal measurements of blood plasma and total body retention are carried out. Binding of labeled antibody to the cellular components of blood is verified to be very low. They have observed bone marrow depression at doses greater than 400 rad. If no special procedures are used to reconstitute marrow after radiation treatment, this level represents a much greater than generally recognized limitation to radiolabeled monoclonal antibody therapy. 25 references, 4 tables

Regional and systemic distribution of anti-tumor x anti-CD3 heteroaggregate antibodies and cultured human peripheral blood lymphocytes in a human colon cancer xenograft

International Nuclear Information System (INIS)

Nelson, H.; Ramsey, P.S.; Kerr, L.A.; McKean, D.J.; Donohue, J.H.

1990-01-01

Anti-tumor antibody (317G5) covalently coupled to an anti-CD3 antibody (OKT3) produces a heteroaggregate (HA) antibody that can target PBL to lyse tumor cells expressing the appropriate tumor Ag. The i.v. and i.p. distribution of radiolabeled HA antibody 317G5 x OKT3 and of radiolabeled cultured human PBL were studied in athymic nude mice bearing solid intraperitoneal tumor established from the human colon tumor line, LS174T. Mice were injected with 125I-labeled HA antibody, 125I-labeled anti-tumor mAb, or 111In-labeled PBL, and at designated timepoints tissues were harvested and measured for radioactivity. 125I-317G5 x OKT3 localized specifically to tumor sites. Tumor radioactivity levels (percent injected dose/gram) were lower with 125I-317G5 x OKT3 HA antibody than with 125I-317G5 anti-tumor mAb, but were similar to levels reported for other anti-tumor mAb. The major difference in radioactivity levels observed between i.v. and i.p. administration of 125I-317G5 x OKT3 was an increase in hepatic radioactivity after i.v. HA antibody administration. HA antibodies produced from F(ab')2 fragments, which exhibit decreased m. w. and decreased Fc receptor-mediated binding, demonstrated improved tumor:tissue ratios as compared to intact antibody HA. 125I-317G5 F(ab')2 x OKT3 F(ab')2 antibody levels were equivalent to intact HA antibody levels in tumor, but were lower than intact HA antibody levels in the blood, bowel, and liver. Tumor:bowel ratios (20:1 at 48 h) were highest when 317G5 F(ab')2 x OKT3 F(ab')2 was injected i.p. Autoradiography confirmed that anti-tumor x anti-CD3 HA antibodies localized specifically to intraperitoneal tumor; that i.p. administered HA antibodies penetrated tumor directly; and that i.v. administered HA antibodies distributed along tumor vasculature

Production of monoclonal antibodies for use in immunoassays based on the magnetizable solid phase separation technique

International Nuclear Information System (INIS)

Charoensiriwatana, W.; Janejai, N.; Krasao, P.

1996-01-01

Monoclonal antibodies to TSH were produced by using mouse-ascites techniques. Various methods for purifying the antibody from the ascetic fluid have been tried in order to obtain an appropriate TSH kit production protocol. The purified antibodies were then immobilized on magnetizable cellulose for developing an IRMA for TSH. A detailed study of the assay system, including the stability of the magnetic adsorbent was made, which showed that the SCIPAc magnetizable cellulose is suitable for the production of TSH - Blood spot IRMA kits for use in the Neonatal hypothyroid screening programme to be launched in Thailand in the near future. (author). 4 refs, 12 figs, 2 tabs

Measurement of IgG-blocking antibodies: development and application of a radioimmunoassay. [/sup 125/I tracer techniques

Energy Technology Data Exchange (ETDEWEB)

Sobotka, A.K.; Valentine, M.D.; Ishizaka, K.; Lichtenstein, L.M.

1976-07-01

A radioimmunoassay for measuring blocking antibodies has been developed. We used the ragweed antigen E system to show that the same blocking antibodies (IgG) measured by inhibition of antigen-induced leukocyte histamine release were precipitated in the binding assay (r/sub s/ = 0.96 p less than 0.001), thus validating a widely applicable technique for measuring blocking antibodies. Binding of phospholipase-A (Phos-A), the major allergen in honey bee venom, was also shown to correlate significantly with inhibition of histamine release. Hymenoptera (insect) hypersensitivity was used as a model to demonstrate application of the binding assay. Sera obtained from patients undergoing whole body extract therapy contained negligible amounts of specific blocking antibodies. Significantly higher blocking antibody titers to both whole honey bee venom and Phos-A were measured in sera drawn from patients immunized with whole venom. The use of the binding radioimmunoassay should facilitate management of allergic disease processes in which blocking antibodies are thought to be protective.

The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides

International Nuclear Information System (INIS)

Akanji, Akinkunmi Ganiyu

2012-01-01

Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera®). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera®) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated the influence of different

Quantitative Assessment of Myocardial Infarction by In-111 Antimyosin Antibody

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Chul; Lee, Kyung Han; Choi, Yoon Ho; Chung, June Key; Park, Young Bae; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Moon, Dae Hyuk [Asan Medical Center, Ulsan University College of Medicine, Seoul (Korea, Republic of)

1991-03-15

Infarct size is a major determinant of prognosis after acute myocardial infarction. Up to date, however, clinically available tests to estimate this size have not been sufficiently accurate. Twelve lead electrocardiogram and wall motion abnormality measurement are not quantitative, and creatine phosphokinase (CPK) measurement is inaccurate in the presence of reperfusion or right ventricular infarction. Methods have been developed to localize and size acute myocardial infarcts with agents that are selectively sequestered in areas of myocardial damage, but previously used agents have lacked sufficient specificity. Antibodies that bind specifically only to damaged myocardial cells may resolve this problem and provide an accurate method for noninvasively measuring infarct size. We determined the accuracy with which infarcted myocardial mass can be measured using single photon emission computed tomography (SPECT) and radiolabeled antimyosin antibodies. Seven patients with acute myocardial infarction and one stable angina patient were injected with 2 mCi of Indium-111 labeled antimyosin antibodies. Planar image and SPECT was performed 24 hours later. None of the patients had history of prior infarcts, and none had undergone reperfusion techniques prior to the study, which was done within 4 days of the attack. Planar image showed all infarct patients to have positive uptakes in the cardiac region. The location of this uptake correlated to the infarct site as indicated by electrocardiography in most of the cases. The angina patient, however, showed no such abnormal uptake. Infarct size was determined from transverse slices of the SPECT image using a 45% threshold value obtained from a phantom study. Measured infarct size ranged from 40 to 192 gr. There was significant correlation between the infarct size measured by SPECT and that estimated from serial measurements of CPK (r=0.73, p<0,05). These date suggest that acute myocardial infarct size can be accurately measured

Detection of anti neutrophil antibodies by radio-iodinated protein A binding test

International Nuclear Information System (INIS)

Cartron, J.; Muller, J.Y.; Tchernia, G.; Paule, B.; Varet, B.

1983-01-01

The granulocyte associated IgG in normal and neutropenic subjects has been determined by a direct quantitative assay using radiolabeled staphylococcal protein A. This assay allows to postulate an immunological mechanism to explain the neutropenia in 19 cases of neutropenias associated with malfunctions of the immune system and in 4 cases of idiopathic neutropenias. Discussed in this report is the possible interaction of immune complexes bound in vivo to the granulocytes. By an immunofluorescence test, it has been possible to detect IgG or IgM antibodies in only 52% of patients with a positive direct assay. The determination of granulocyte-associated IgG is therefore a better indicator for defining an auto-immune neutropenia than the detection of free antibodies in the sera [fr

Long-circulating liposomes radiolabeled with [18F]fluorodipalmitin ([18F]FDP)

International Nuclear Information System (INIS)

Marik, Jan; Tartis, Michaelann S.; Zhang, Hua; Fung, Jennifer Y.; Kheirolomoom, Azadeh; Sutcliffe, Julie L.; Ferrara, Katherine W.

2007-01-01

Synthesis of a radiolabeled diglyceride, 3-[ 18 F]fluoro-1,2-dipalmitoylglycerol [[ 18 F]fluorodipalmitin ([ 18 F]FDP)], and its potential as a reagent for radiolabeling long-circulating liposomes were investigated. The incorporation of 18 F into the lipid molecule was accomplished by nucleophilic substitution of the p-toluenesulfonyl moiety with a decay-corrected yield of 43±10% (n=12). Radiolabeled, long-circulating polyethylene-glycol-coated liposomes were prepared using a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N- [methoxy(polyethyleneglycol)-2000] ammonium salt (61:30:9) and [ 18 F]FDP with a decay-corrected yield of 70±8% (n=4). PET imaging and biodistribution studies were performed with free [ 18 F]FDP and liposome-incorporated [ 18 F]FDP. Freely injected [ 18 F]FDP had the highest uptake in the liver, spleen and lungs. Liposomal [ 18 F]FDP remained in blood circulation at near-constant levels for at least 90 min, with a peak concentration near 2.5%ID/cc. Since [ 18 F]FDP was incorporated into the phospholipid bilayer, it could potentially be used for radiolabeling a variety of lipid-based drug carriers

Immunoblotting studies of coagulation factor XII, plasma prekallikrein, and high molecular weight kininogen

International Nuclear Information System (INIS)

Laemmle, B.B.; Berrettini, M.; Griffin, J.H.

1987-01-01

Immunoblotting techniques for the qualitative and quantitative analysis of FXII, PK, and HMWK in whole plasma are presented. Sensitive, specific, and quantitative immunodetection of FXII and PK can be achieved by developing the blots with polyclonal antiserum followed by radiolabeled FXII or PK, respectively. This approach is based on the assumption that bivalent antibodies bind monovalently to the NC-bound antigen and have available binding sites to bind radiolabeled antigen derived from the fluid phase. This radiolabeled antigen overlay principle may be generally useful for immunodetection of any trace protein in complex mixtures, provided that the radiolabeled purified antigen is available. Immunoblotting may also be helpful for the partial characterization of the structural or functional abnormalities of CRM-positive variant molecules. For example, earlier studies of a FXII-variant molecule that had been purified and characterized were supported by immunoblotting studies of the CRM-positive deficient plasma. Quantitative measurement of HMWK is possible using a monoclonal antibody directed against the light chain of HMWK followed by radiolabeled secondary antibody. Quantitation of cleaved and single-chain HMWK is possible using dilutions of dextran sulfate-activated NHP on unreduced SDS-PAGE and dilutions of unactivated NHP with reduced SDS-PAGE as standards. These assays allow assessment of the degree of in vivo activation of the contact system in various disease states

Labelled antibody techniques in glycoprotein estimation

International Nuclear Information System (INIS)

Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

1977-01-01

The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

Radioimmunoimaging in malignant melanoma with 111In-labeled monoclonal antibody 96.5

International Nuclear Information System (INIS)

Murray, J.L.; Rosenblum, M.G.; Sobol, R.E.

1985-01-01

A radiolabeled monoclonal antibody (96.5) reactive with an Mr 97,000 antigen found on over 80% of melanoma cell lines and tissue extracts was examined for its ability to detect malignant melanoma metastases in vivo. For imaging purposes, it was conjugated with diethyltriaminepentaacetic acid and subsequently labeled with 111 In by chelation. Thirty-one patients with metastatic melanoma received single injections of monoclonal antibody 96.5 at concentrations ranging from 0.5 to 20 mg and at specific activities of 111 In ranging from 0.125 to 4 mCi/mg. Total-body scans were performed at various time intervals following administration. No serious side effects were observed. Of a total of 100 previously documented metastatic sites, 50 imaged for a specificity of 50%. The number of sites imaged increased significantly as the amount of antibody administered increased relative to the average radiation dose. Considerable background uptake of isotope was observed in blood pool and other organs with gradual acquisition of label in tumor sites by 48 to 72 h. Hence, tumor imaging of melanoma using 111 In-labeled monoclonal antibody 96.5 appeared feasible, especially at antibody doses above 2 mg

Radiolabeling of equine platelets in plasma with 111In-(2-mercaptopyridine-N-oxide) and their in vivo survival

International Nuclear Information System (INIS)

Coyne, C.P.; Kelly, A.B.; Hornof, W.J.; O'Brien, T.R.; Philp, M.S.; Lamb, J.F.

1987-01-01

A method is presented for the in vitro isolation and radiolabeling of equine platelets with the isotope indium 111 ( 111 In: half-life = 2.8 days, gamma = 173 keV, 89%; 247 keV, 94%). The technique described involves complexing 111 In with the lipid-soluble chelating agent, 2-mercaptopyridine-N-oxide (merc), in an aqueous medium. 111 In-merc platelet-labeling efficiencies in autologous plasma pretreated with or without ferric citrate reagent were 82 +/- 7% and 24 +/- 12%, respectively. Mean intravascular survivals of 111 In-merc-radiolabeled platelets in 8 healthy horses according to simple linear, exponential, mean, weighted-mean residual sum of squares analysis, and multiple-hit model were 5.5 +/- 0.49, 3.5 +/- 0.53, 4.5 +/- 0.18, 4.3 +/- 0.65, and 3.6 +/- 0.97 days, respectively

Bivalent fragment of the ior-CEA1 antibody. A challenge to the positive CEA tumors radioimmunotherapy

International Nuclear Information System (INIS)

Ravelo, Rolando; Sanchez, Iradia; Pimentel, Gilmara; Oliva, Juan; Perez, Lincidio; Ayala, Marta; Bell, Hansell; Gavilondo, Jorge

2006-01-01

The directed radiotherapy of the solid tumors with fragments recombinants of radiolabelled antibodies is a topic of current investigation, so much at preclinical level as clinical. This work describes the preclinical characterization of a new fragment type diabody of the AcMo ior CEA1 that has been labelled with 131 I for their use in the diagnosis and the therapy of CEA positive tumors. The radiolabelling methodology used allows the incorporation of more than 90% of the radio iodine to the molecule without committing the capacity of recognition of its antigen significantly. The combination of the favourable properties pharmacy kinetic and high selective accumulation in the tumor, they make of the diabody anti CEA an appropriate candidate for the radioimmunodiagnosis and the radioimmunotherapy of tumors that expresses CEA (Author)

Elucidating the role of dissolution in CeO{sub 2} nanoparticle plant uptake by smart radiolabeling

Energy Technology Data Exchange (ETDEWEB)

Schymura, Stefan; Hildebrand, Heike; Franke, Karsten [Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Leipzig (Germany); Fricke, Thomas [Vita34 AG, Business Unit BioPlanta, Leipzig (Germany); University of Bonn, Institute of Crop Science and Resource Conservation, Division Plant Nutrition (Germany)

2017-06-19

The identification of major uptake pathways in plants is an important factor when evaluating the fate of manufactured nanoparticles in the environment and the associated risks. Using different radiolabeling techniques we were able to show a predominantly particulate uptake for CeO{sub 2} nanoparticles in contrast to a possible uptake in the form of ionic cerium. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Intraperitoneal delivery of monoclonal antibodies: enhanced regional delivery advantage using intravenous unlabeled anti-mouse antibody

International Nuclear Information System (INIS)

Wahl, R.L.; Fisher, S.

1987-01-01

Radiolabeled monoclonal antibodies (MAb) delivered intraperitoneally expose cells in contact with peritoneal fluid to considerably higher levels of MAb than if the MAb dose were given intravenously. This regional delivery advantage for intact MAb is present mainly due to the relatively slow exit of MAb from the peritoneal fluid to the blood. Eventually, following i.p. injection, blood levels of MAb rise resulting in exposure of the animal to high systemic MAb levels and potential toxicity. In this series of experiments, systemic exposure was minimized by the administration of unlabeled goat polyclonal anti-mouse antibody intravenously from 1 1/2 to 6 h following i.p. MAb injection. This maneuver results in the formation of immune complexes with their subsequent clearance and dehalogenation by the reticuloendothelial system, thus minimizing systemic MAb exposure. This approach, of increasing systemic clearance of MAb, did not alter intraperitoneal MAb levels and thus significantly increased the regional delivery advantage to the peritoneal cavity by 70-100%. This approach provides an immunologic rationale for the further enhancement of MAb delivery to i.p. foci of malignant disease and may have diagnostic and therapeutic utility. (author)

Human kinetic distribution of I-123 F(Ab')/sub 2/ and FAb compared to the parent I-123 intact antibody

International Nuclear Information System (INIS)

De Nardo, S.J.; De Nardo, G.L.; O'Grady, L.F.; Peng, J.S.; Macey, D.J.; Mills, S.L.; Caridiff, R.D.; Epstein, A.L.

1985-01-01

Studies of radiolabeled monoclonal antibodies are being performed by many investigators using a variety of molecular forms of the antibody. This study evaluates two I-123-labeled antibodies (Lym-1 IgG2a and B6.01 IgG1) and their I-123-labeled FAb and F(Ab')/sub 2/ for relative whole body distribution and kinetics, selected organ kinetics, and site of degradation. Evidence of immunocomplex formation, circulating antigen, and HAMA, were monitored by HPLC-TSK analysis and appropriate radioassays of the plasma. Each antibody and each I-123-labeled fragment has been evaluated in 5 patients. One patient had serial comparisons of the radiolabeled parent molecule, F(Ab')/sub 2/ (100μg and 5 mg) and FAb (100μg) of Lym-1. Blood clearance, urine excretion rate, and plasma and urine HPLC fractionation of the radioactive species were determined. Whole body clearance by total body scans and organ clearance were obtained by geometric mean of anterior and posterior areas of interest. The FAb and F(Ab')/sub 2/ fragments had similar blood pool recovery 5 minutes after the 5-minute injection. These were the same as blood levels when 5mg of intact I-123-labeled antibody was given. The second phase of the blood curves for F(Ab')/sub 2/ had a T1/2 of 35-40 hours and for FAb was 15-20 hours. Urine excretion varied, but agreed with total body loss from body scan information. The patient with serial studies had a 24-hour residual dose of 82% for FAb, 62% for 10μg for F(Ab')/sub 2/ and 61% for 5mg of F(Ab')/sub 2/. Renal uptake for all patients was higher and more persistent with both fragments than intact antibody, but hepatic uptake was less

Utilisation of radiolabeled antibiotic for the diagnosis of infectious foci

International Nuclear Information System (INIS)

Khammassi, Sabrine; Gharbi, Sabrine

2009-01-01

Nuclear imaging is a non-invasive exploration technique, used for rapid diagnostic of infectious disease .Thus, for osteoarticular infection scintigraphic techniques were proposed to ameliorate the diagnostic sensibility and the use of radiolabeled antibiotics as imaging agents of infectious loci become more and more recognized. In this work, a new sulfanil amid derivative, the N sulfanilamide-ferrocene-carboxamide was chemically synthesized then labeled with technetium-99m, with a radiochemical yield, 87 pour cent. In in-vitro studies were done with E.coli. first , the up-take of labeled molecule was estimated as 40 pour cent. Then, the bacteriostatic al effect of the molecule was de terminated by considering the Optical Density at 600 nm. The obtained results, encourage us to do more, with biodistribution on normal and infected mice; with Staphylococcus aureus. Then to carry out scintigraphic imaging with gamma camera to check out the potentiality of the molecule as an infectious imaging agent. (Author)

Astatine-211 labeling. A study towards automatic production of astatinated antibodies

International Nuclear Information System (INIS)

Emma Aneheim; Per Albertsson; Sture Lindegren; Holger Jensen

2015-01-01

Targeted alpha therapy is especially interesting for therapy of microscopic cancer tumors due to short path length and high linear energy transfer of the alpha particles. One of the most promising nuclides for targeted alpha therapy is 211 At. To facilitate larger clinical studies using 211 At, the current manual synthesis of radiolabeled antibodies would benefit from being transferred into an automated method. In this work, successful modifications of the manual synthesis have been performed in order to adapt it to automation. The automatic synthesis has also been tested using the modified synthesis method. (author)

Use of radioisotopic immunoassay to evaluate locally produced secondary antibodies as a separation system for some in vitro investigations in nuclear medicine

International Nuclear Information System (INIS)

Ali, N.I.; Mohammed, M.S.; Osman, M.M.; Abdalla, O.M.; Eltayb, A.M.; Elamin, A.M.; Khalid, A.Sh.

2003-01-01

Radioimmunoassay (RIA) is one of the in vitro diagnostic methods in nuclear medicine. The most important factor in RIA reagents to be considered is the antibody production, as specific antibodies with high affinity are the backbone of RIA techniques. In this experiment iodine (I 125 ) radiolabelled antigens were used to evaluate locally produced donkey anti-sheep serum (DASS) as a separating agent in RIA. Two local donkeys were immunized with non-immunized sheep immunoglobulin (IgG) to produce donkey anti-sheep secondary antibodies. Samples were collected from the two donkeys, purified, dialysed, qualitatively tested for the presence of antibodies, which were then quantitatively evaluated and utilized as precipitating agent in RIA by adding the primary antibodies. Using RIA methodology the antibodies were titrated against three different analytes (thyroxine T 4 , triiodothyronine T 3 , and progesterone) for which the primary antibodies already raised in sheep in order to be used as secondary antibody separation system for them. The titre was found to be 1/40 for the T 4 and progesterone while 1/6 for T 3 . Then local antibodies replaced the commercial ones using the suitable titre for each analyte. Upon comparison of the obtained results of patient samples and quality control (Bio rad) using the local DASS and commercial ones. The correlation coefficient (r) for T 4 , T 3 and progesterone were 0.950, 0.878 and 0.950 respectively. Six liters of antiserum were collected in a period of one year. Considering the workload of the country for the above mentioned three analytes this amount is enough to meet the needs for the the next ten years in Sudan. this production will save a lot of hard currency paid for importing DASS from abroad. (Author)

Radiolabeling Of Albumin Particles With Yttrium-90

International Nuclear Information System (INIS)

Nguyen Thi Thu; Nguyen Thi Khanh Giang; Bui Van Cuong, Vo Thi Cam Hoa

2011-01-01

This paper presents the process of the radiolabeling of microaggregated albumin particles with radionuclide Yttrium-90 using the directed method. The albumin microsphere kit was prepared in sodium phosphate buffer. The original solution includes 2 mg albumin particle and 0.5 mg stannous chloride dihydrate. The albumin particles size was ranged from 5 ?m to 30 ?m. The mixture was washed three times with phosphate buffer saline, pH 7.2 by centrifugation and suspended in 0.5 M sodium acetate buffer, pH 6. Yttrium - 90 in 1.0 M acetic acid was collected from 90 Sr/ 90 Y generator. The labeling of the particles with Y-90 (185 MBq) was performed at pH 5.5 in acetate buffer with agitating for 60 min at room temperature. The labeled albumin suspensions were centrifuged at 3000 rpm for 15 min. Labeling yields was calculated using centrifugation, filtration and compared with paper chromatography, which is developed in the Tris Acetic EDTA. In this system, the unbound of Y-90 migrates to an R f of 0.9-1.0 and the radiolabeled albumin particles remains at the point of origin (R f = 0). The size of 90 Y-albumin particles was compared with the albumin particles in the original solution to be sure that they did not change during the labeling treatment. The radiolabeling yields were more than 80%. The labeled compound was dialysis in phosphate buffer. The radiochemical purity was 98%. The 90 Y- albumin is an ideal radiopharmaceutical for potential use in malignant cancer treatment as brachytherapy. (author)

Radiolabelled peptides: New radiopharmaceuticals for targeted therapy

International Nuclear Information System (INIS)

Chinol, M.

2001-01-01

Radiolabelled peptides have been the focus of an increasing interest by the nuclear medicine community within the last few years. This has mainly been due to successful development of one of these peptides, somatostatin, as a tool to visualise various pathologic conditions known to express a high number of somatostatin receptors. Somatostatin receptors have been identified in different tumours such as neuroendocrine tumours, tumours of the central nervous system, breast, lung and lymphatic tissue. These observations served as the biomolecular basis for the clinical use of radiolabelled somatostatin analogs, which are at present of great interest for diagnostic and therapeutic applications. A promising somatostatin analogue, DOTA-D-Phe 1 -Ty 3 -octreotide, named DOTATOC, has shown favourable biodistribution and high affinity binding to SSTR2 and SSTR5, high hydrophilicity and ease of labelling and stability with 111 In and 90 Y. A clinical trial aimed at evaluating the biodistribution and dosimetry of DOTATOC radiolabelled with 111 In, in anticipation of therapy trials with 90 Y-DOTATOC in patients was undertaken. 111 In-DOTATOC showed favourable pharmacokinetics (fast blood clearance and urinary excretion) and biodistribution, and high affinity to tumours expressing somatostatin receptors (thus, a high residence time in tumour). These results are promising for therapy trials with 90 Y-DOTAOC, for which radiation dosimetry appears acceptable for normal organs (including the red marrow). Moreover, labelling conditions of DOTATOC with 90 Y has been optimised in order to achieve labelling yields of more than 98% and specific activities of greater than 60 GBq (1.6 Ci)/μmol. (author)

Synthesis of sup 14 C-radiolabelled Tilmicosin

Energy Technology Data Exchange (ETDEWEB)

Crouse, G D; Terando, N H [Lilly (Eli) and Co., Indianapolis, IN (USA). Lilly Research Labs.

1989-04-01

Tilmicosin was radiolabelled with carbon-14 on the 3,5-dimethylpiperidinyl sidechain as a requirement for animal metabolism studies. A new radiosynthesis of 3,5-dimethyl-piperidine was developed for this purpose. Incorporation into the desmycosin nucleus was accomplished by a reductive amination reaction. (author).

The binding parameters of radiolabelled monoclonal F (ab')2 and Fab' fragments relative to immunoglobulin G in reactions with surface-bound antigens

International Nuclear Information System (INIS)

Fjeld, J.G.; Nustad, K.; Michaelsen, T.E.

1992-01-01

The binding parameters of iodine-125-labelled intact monoclonal immunoglobulin G (IgG), F(ab') 2 and Fab' fragments were compared. The study was carried out with the two monoclonal antibodies (MoAbs) K13 and K16 specific for human Ig light chains κ and λ, respectively. When testing the 125 I-MoAbs against monodisperse polymer particles coated with the specific antigens, the K a for the F(ab') 2 fragments were similar to that for IgG, while the K a for the Fab' fragments were reduced to 10%-20% of that for IgG. The number N of effective target sites revealed with Fab' was higher than with F(ab') and IgG, presumably because less surface area is occupied by the small Fab' molecules. The immunoreactive fraction F ranged according to IgG>F(ab') 2 >Fab'. The explanation of the moderate difference between the K a of the monoclonal Fab' and the divalent IgG and F(ab') 2 was that the divalent molecules were not divalently attached to the particles. When testing the same antibody preparations against humanlymphoma cells producing Ig with light chains κ or λ, the binding results were less reliable than when particles were utilised, presumably due to antigen shedding. Different MoAbs vary in their loss of immunoreactivity due to enzymatic degradation and the radiolabelling procedure. The preparation of the radiolabelled fragments should therefore be optimized for each MoAb, and evaluation is necessary before injection. Artificial targets with a low leakage of antigen, like the monodisperse polymer particles here applied, are recommended for the in vitro evaluation of the immunoreactivity of labelled MoAb preparations. (orig.)

Synthesis, radiolabeling and biodistribution of a new opioid glucuronide derivative. Ethyl-morphine glucuronide (em-glu)

International Nuclear Information System (INIS)

Enginar, H.

2012-01-01

In current study, ethyl-morphine (em) was synthesized from the morphine and glucuronidated via enzymatic mechanism. The conjugated glucuronide ethyl-morphine (em-glu) was radiolabeled with 131 I using iodogen method. The quality control studies of radiolabeled compound ( 131 I-em-glu) were done with Thin Layer Radio Chromatography to confirm the radiolabeling efficiency. Biodistribution studies of 131 I labeled em-glu were run on healthy male Albino Wistar rats. The distribution figures demonstrated that 131 I-em-glu was eliminated through the small intestine, large intestine and accumulated in urinary bladder both receptor blocked and unblocked biodistribution studies. A greater uptake of the radiolabeled substance was observed in the m.pons, hypothalamus and mid brain than in the other branches of the rats' brains. (author)

Pharmacokinetics of internally labeled monoclonal antibodies as a gold standard: comparison of biodistribution of 75Se-, 111In-, and 125I-labeled monoclonal antibodies in osteogenic sarcoma xenografts in nude mice

International Nuclear Information System (INIS)

Koizumi, M.; Endo, K.; Watanabe, Y.; Saga, T.; Sakahara, H.; Konishi, J.; Yamamuro, T.; Toyama, S.

1989-01-01

In order to know the true biodistribution of anti-tumor monoclonal antibodies, three monoclonal antibodies (OST6, OST7, and OST15) against human osteosarcoma and control antibody were internally labeled with 75Se by incubating [75Se]methionine and hybridoma cells. 75Se-labeled monoclonal antibodies were evaluated both in vitro and in vivo using the human osteogenic sarcoma cell line KT005, and the results were compared with those of 125I- and 111In-labeled antibodies. 75Se-, 125I- and 111In-labeled monoclonal antibodies had identical binding activities to KT005 cells, and the immunoreactivity was in the decreasing order of OST6, OST7, and OST15. On the contrary, in vivo tumor uptake (% injected dose/g) of 75Se- and 125I-labeled antibodies assessed using nude mice bearing human osteosarcoma KT005 was in the order of OST7, OST6, and OST15. In the case of 111In, the order was OST6, OST7, and OST15. High liver uptake was similarly seen with 75Se- and 111In-labeled antibodies, whereas 125I-labeled antibodies showed the lowest tumor and liver uptake. These data indicate that tumor targeting of antibody conjugates are not always predictable from cell binding studies due to the difference of blood clearance of labeled antibodies. Furthermore, biodistribution of both 111In- and 125I-labeled antibodies are not identical with internally labeled antibody. Admitting that internally labeled antibody is a ''gold standard'' of biodistribution of monoclonal antibody, high liver uptake of 111In-radiolabeled antibodies may be inherent to antibodies. Little, if any, increase in tumor-to-normal tissue ratios of antibody conjugates will be expected compared to those of 111In-labeled antibodies if stably coupled conjugates are administered i.v

Radioimmunoscintigraphy with I-131-labelled anti-CEA monclonal antibody in colorectal cancer patients

International Nuclear Information System (INIS)

Xie Tianhao

1988-01-01

Twenty three colorectal carcinoma and two benign polyposis patients with operatively and histologically proven were studied by radioimmunoscintigraphy, using anti-CEA monoclonal antibodies (C14-17 and C50) radiolabeled with I-131 . Computer assisted processing for the subtraction of Tc-99m background radioactivity was used to enhance the detection and localization of tumor which is visualized by immune scintigraphy. The size of tumor and the ratios of tumor to nontumor (T/NT) are two very important factors for the external immunoscintigraphy. The antibody uptake and retention in tumor are likely to depend on the degree of vascularity and diffusion into the viable tumor mass. Based upon the obtained results, the sensitivity of the method (true-poditive) was 91%, its specificity (true-negative) was 100%. This study thus indicates that radioimmunoscintigraphy of cancer with radioactive anti-CEA monoclonal antibody is very uaeful in the diagnoses of patients with CEA-containing neoplasms

Use of radio isotopic immunoassay to evaluate locally produced secondary antibodies as a separation system for some in vitro investigations in nuclear medicine

International Nuclear Information System (INIS)

Ali, N.I.; Mohammed, M.S.; Osman, M.M.; Abdalla, O.M.; Eltayeb, M.A.H.; Elamine, A.M.; Khalid, A.SH.

2003-01-01

Radioimmunoassay (RIA) is one of the in vitro investigations in nuclear medicine. The first and ost important factor in RIA reagents to be considered is the antibody production, as specific antibodies with high affinity are the backbone of RIA techniques. In this experiment Iodine 1( 125 ) radiolabelled antigens used to evaluate locally produced Donkey Anti-Sheep Serum(DASS) in order to be used as a separating agent in RIA. Two local donkies were immunized with non-immunized sheep immunoglobulin(IgG) to produce donkey anti-sheep secondary antibodies. Samples were collected from the two donkies, purified, qualitatively tested for the presence of antibodies, which were then quantitatively evaluated and utilized as precipitating agent in RIA by binding to the primary antibodies. Using RIA methodology the antibodies were titrated against three different analytes (Thyroxine T 4, Triiodothyronine T 3, and Progesterone) for which the primary antibodies already raised in sheep in order to be used as secondary antibody separation system for them. The titre was found to be 1/40 for the T-4 and progesterone while 1/16 for T 3 . Then local antibodies replaced the commercial ones using the suitable titre for each analyte. Upon comparison of the obtained results of patient samples and quality control(Bio Rad)using the local DASS and commercial ones. The correlation co-efficient (r)for T 4, T3, and progesterone were 0.950, 0.878, and 0.950, respectively. Six liters of antiserum were collected in a period of one year. Considering the workload of the country for the above mentioned three analytes this enough to meet the needs for at least the next ten years in Sudan. This production will save a lot of hard currency paid for importing DASS from abroad

Radioimmunodetection of human tumor xenografts by monoclonal antibody F(ab')/sub 2/ fragments

Energy Technology Data Exchange (ETDEWEB)

Herlyn, D.; Munz, D.L.; Herlyn, M.; Koprowski, H.; Powe, J.; Alavi, A.; Meinken, G.E.; Srivastava, S.C.

1986-01-01

Procedures are described for the radiolocalization of human tumors by murine monoclonal antibodies (MAb) in animal model systems. Visualization of tumor xenografts was clearer in nude mice compared to experimentally immunosuppressed mice due to the higher tumor viability. MAb localization in tumor tissue was greatly enhanced when F(ab')/sub 2/ fragments rather than intact antibody molecules were used. Although tumors could be visualized with /sup 131/I-, /sup 123/I-or /sup 111/In-labeled MAb fragments without background subtraction, tumor-to-background ratios of radioactivity were highest for /sup 131/I-labeled fragments. /sup 131/I-labeled F(ab')/sub 2/ fragments of eight MAb against human colorectal carcinoma, melanoma or lung carcinoma localized specifically only in those tumors that bound the MAb in vitro and not in unrelated tumors. Radiolabeled fragments of MAb with other specificities (anti-hepatitis virus MAb) did not localize in tumors. All MAb that inhibited tumor growth in nude mice effectively localized these tumors by ..gamma..-scintigraphy. Some MAb were effective in localizing tumors but ineffective in inhibiting their growth. The ability of the specific radiolabeled F(ab')/sub 2/ fragments to localize in tumor grafts correlated significantly with MAb binding affinity and density of antigenic sites on tumor cells together, but not with either in vitro binding parameter alone.

Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, April 15, 1992--October 31, 1992

Energy Technology Data Exchange (ETDEWEB)

Zalutsky, M.R.

1992-08-01

This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

Comparison of endogenous and radiolabeled bile acid excretion in patients with idiopathic chronic diarrhea

International Nuclear Information System (INIS)

Schiller, L.R.; Bilhartz, L.E.; Santa Ana, C.A.

1990-01-01

Fecal recovery of radioactivity after ingestion of a bolus of radiolabeled bile acid is abnormally high in most patients with idiopathic chronic diarrhea. To evaluate the significance of this malabsorption, concurrent fecal excretion of both exogenous radiolabeled bile acid and endogenous (unlabeled) bile acid were measured in patients with idiopathic chronic diarrhea. Subjects received a 2.5-microCi oral dose of taurocholic acid labeled with 14C in the 24th position of the steroid moiety. Endogenous bile acid excretion was measured by a hydroxysteroid dehydrogenase assay on a concurrent 72-h stool collection. Both radiolabeled and endogenous bile acid excretion were abnormally high in most patients with chronic diarrhea compared with normal subjects, even when equivoluminous diarrhea was induced in normal subjects by ingestion of osmotically active solutions. The correlation between radiolabeled and endogenous bile acid excretion was good. However, neither radiolabeled nor endogenous bile acid excretion was as abnormal as is typically seen in patients with ileal resection, and none of these diarrhea patients responded to treatment with cholestyramine with stool weights less than 200 g. These results suggest (a) that this radiolabeled bile acid excretion test accurately reflects excess endogenous bile acid excretion; (b) that excess endogenous bile acid excretion is not caused by diarrhea per se; (c) that spontaneously occurring idiopathic chronic diarrhea is often associated with increased endogenous bile acid excretion; and (d) that bile acid malabsorption is not likely to be the primary cause of diarrhea in most of these patients

Electrophoretic analysis of proteinases in sodium dodecyl sulfate-polyacrylamide gels containing copolymerized radiolabeled protein substrates: Application to proenkephalin processing enzymes

Energy Technology Data Exchange (ETDEWEB)

Irvine, J.W.; Roberts, S.F.; Lindberg, I. (Louisiana State Univ. Medical Center, New Orleans (USA))

1990-10-01

A novel method is described for the zymographic analysis of proteinases in sodium dodecyl sulfate-polyacrylamide gels containing copolymerized radiolabeled protein substrates such as ({sup 35}S)methionine-labeled proenkephalin or {sup 125}I-labeled proinsulin. After electrophoresis the enzyme is reactivated and cleaves the radiolabeled in situ substrate into smaller peptides. These small peptides are able to diffuse out of the gel, leaving clear areas against a dark background when visualized by autoradiography. The technique can be used to detect as little as 200 fg of trypsin using only 50 ng (1.25 microCi) of ({sup 35}S)proenkephalin. Soluble- and membrane-bound adrenal trypsin-like enzyme were isolated from bovine adrenal chromaffin granules. Both proteinases cleaved ({sup 35}S)methionine-labeled proenkephalin but not {sup 125}I-labeled proinsulin. Moreover, both had a Mr of approximately 30,000. The potential of this technique for general use is discussed. An additional method using the synthetic fluorogenic substrate t-butoxycarbonyl Glu-Lys-Lys aminomethylcoumarin is also described.

Quantitative autoradiographic mapping of focal herpes simplex virus encephalitis using a radiolabeled antiviral drug

International Nuclear Information System (INIS)

Price, R.

1984-01-01

A method of mapping herpes simplex viral infection comprising administering a radiolabeled antiviral active 5-substituted 1-(2'-deoxy-2'-substituted-D-arabinofuranosyl) pyrimidine nucleoside to the infected subject, and scanning the area in which the infection is to be mapped for the radiolabel

Demonstration of monoclonal anti-carcinoembryonic antigen (CEA) antibody internalization by electron microscopy, western blotting and radioimmunoassay.

Science.gov (United States)

Tsaltas, G; Ford, C H; Gallant, M

1992-01-01

One of the important factors affecting the action of monoclonal antibodies (Mabs) or immunoconjugates on tumour sites depends on whether the Mab is internalized by the cancer cells in question. The underexplored subject of internalization is discussed in this paper, and a number of in vitro techniques for investigating internalization are evaluated, using a model which consists of a well characterized anti-carcinoembryonic antigen (anti-CEA) Mab and a number of CEA expressing human cancer cell lines. Employing two alternative radiolabeling assays, evidence for internalization of the anti-CEA Mab by a CEA-positive colorectal cancer cell line (LS174T) was obtained throughout the time intervals examined (5 min to 150 min). Electronmicroscopy employing horseradish-peroxidase labeled anti-CEA Mab and control antibody permitted direct visualization of anti-CEA Mab-related staining in intracellular compartments of a high CEA-expressor human colorectal cell line (SKCO1). Finally Western blots of samples derived from cytosolic and membrane components of solubilized cells from lung and colonic cancer cell lines provided evidence for internalized anti-CEA Mab throughout seven half hour intervals, starting at 5 minutes. Internalized anti-CEA was detected in all CEA expressing cell lines (LS174T, SKCO1, BENN) but not in the case of a very low CEA expressor line (COLO 320).

Elevated Lipoprotein(A Impairs Platelet Radiolabeling Yield

Directory of Open Access Journals (Sweden)

Susanne Granegger

2015-02-01

Full Text Available Objectives: Platelet radiolabeling in clinical routine usually results in labeling efficiencies (LE above 80%. A variety of risk factors and clinical conditions are known to impair platelet labeling yield, among them elevated triglycerides and low-density lipoproteins. The potential influence of lipoprotein(a (Lp(a, an atherogenic lipoprotein particle containing a kringle subunit, which is widely found in the proteins of fibrinolysis pathway, has never been studied. Normal Lp(a levels range below 30 mg/ dl. The exact prevalence of elevated Lp(a is unknown, most likely ranging below 10%. Even more rare is an isolated elevation despite an otherwise normal lipoprotein profile. Methods: We examined the role of isolated elevated Lp(a (> 50 mg/dl, ranging up to 440 mg/dl compared to patients with normal lipid profile. Platelets were radiolabeled with in-111-oxine at 37 °C for 5 minutes using ISORBE-consensus methodology. Results: The findings indicate that already at levels below 100 mg/dl Lp(a decreases LE. LE assessment after cross-incubation of hyper-Lp(a platelets with normal Lp(a plasma and vice versa reveals that platelets rather than the plasmatic environment are responsible for the deterioration of labeling yield. This behavior already has been reported for elevated low-density lipoproteins. Apparently, the quantitative influence of LDL and Lp(a/mg is comparable. Plotting the sum of LDL and Lp(a versus LE reveals a clear significant negative correlation. Conclusion: As extremely elevated Lp(a, particularly above 150 mg/dl, may significantly impair labeling results. We therefore recommend to include extremely elevated Lp(a into the list of parameters, which should be known before performing radiolabeling of human platelets.

Comparative pharmacokinetics and biodistribution studies of {sup 99m}Tc-annexin V produced by different radiolabeling methods

Energy Technology Data Exchange (ETDEWEB)

Santos, Josefina da Silva; Pujatti, Priscilla Brunelli; Couto, Renata Martinussi; Mengatti, Jair; Araujo, Elaine Bortoleti de, E-mail: jssantos@usp.b, E-mail: priscillapujatti@yahoo.com.b, E-mail: renatamartinussicouto@yahoo.com.b, E-mail: jmengatti@ipen.b, E-mail: ebaraujo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2009-07-01

The use of radiolabeled annexin A5 (ANXA5) to detect cell death in vivo has increased in the last years. Several {sup 99m}Tc-labeling techniques were reported using different cores, such as [{sup 99m}Tc=O]{sup +3}, [{sup 99m}Tc]HYNIC, [{sup 99m}Tcident toN]{sup +2} and [Tc(CO{sub 3})]{sup +1}. The goal of the present work was to evaluate the influence of {sup 99m}Tc cores in the biological behavior of radiolabeled ANXA5 in Swiss mice using [{sup 99m}Tc=O]{sup +3}, [{sup 99m}Tc]HYNIC cores. Ethylenedicysteine (EC) was applied to obtain [Tc=O]{sup +3} core, N,N,N',N'-tetramethyl(succinimide) uranium tetrafluoroborate (TSTU) was employed to transfer the carboxyl group to their corresponding hydroxysuccinimide ester and HYNIC-ANXA5 was provided by National Cancer Institute-Frederick. ITLC-SG and HPLC analysis were applied to determine non-desirable products and the stability of preparations was evaluated after incubation at room temperature, 4 deg C and in human serum at 37 deg C. In vivo biodistribution and kinetics studies were performed after the intravenous injection of {sup 99m}Tc-HYNIC-ANXA5 and {sup 99m}Tc-EC-ANXA5 and pharmacokinetic parameters were calculated using Biexp software. ANXA5 was radiolabeled at room temperature with high yield (> 95%). The results of biodistribution in mice showed, as expected, higher renal uptake of {sup 99m}Tc-HYNICANXA5 and higher liver uptake of {sup 99m}Tc-EC-ANXA5. The percent injected activity per gram (% IA/g) in liver at 0.5 hours were 6.52 and 1.09 and in kidneys were 1.59 and 32.2 for {sup 99m}Tc-EC-ANXA5 and {sup 99m}Tc-HYNICANXA5, respectively. The results of radioactivity in blood showed that both HYNIC- and EC- radiolabeled ANXA5 presented fast blood clearance. In this study two {sup 99m}Tc-ANXA5 obtained from three different available radiolabeling methods presently were investigated. Each labeling method possesses unique advantages and disadvantages. (author)

Preparation and radiolabeling of human serum albumin (HSA)-coated magnetite nanoparticles for magnetically targeted therapy

International Nuclear Information System (INIS)

Zhang Chunfu; Cao Jinquan; Yin Duanzhi; Wang Yongxian; Feng Yanlin; Tan Jiajue

2004-01-01

In this paper, we describe the preparation of human serum albumin-coated magnetic particles of about 200 nm in diameter with narrow size distribution radiolabeled with 188 Re for the purpose of magnetically targeted therapy. The optimum radiolabeling conditions are: SnCl 2 ·2H 2 O 8 mg/ml, citric acid 20 mg/ml, vitamin C 8 mg/ml, labeling volume 500 μl and a reaction time of 3 h. The stability of the radiolabeled particles is suitable for in vivo study

Antibody engineering: methods and protocols

National Research Council Canada - National Science Library

Chames, Patrick

2012-01-01

"Antibody Engineering: Methods and Protocols, Second Edition was compiled to give complete and easy access to a variety of antibody engineering techniques, starting from the creation of antibody repertoires and efficient...

Method for radiolabeling proteins with technetium-99m

International Nuclear Information System (INIS)

Crockford, D.R.; Rhodes, B.A.

1984-01-01

In accordance with this invention, a substrate to be radiolabeled with technetium-99m is admixed with a buffered stannous chloride composition having a pH between about 4.5 and about 8.5 wherein the stannous chloride is produced from a non-oxidized tin source, the buffered stannous chloride is purged of oxygen and the buffer comprises a mixture of alkali metal biphthalate and an alkali metal tartrate. Alternatively, the buffer may include alkali metal borate or gentisate. The stannous chloride solution is admixed with the buffer and the resultant mixture is neutralized with sodium hydroxide. The neutralized solution then is admixed with the substrate eventually to be radiolabeled with technetium-99m. This solution is allowed to incubate for several hours (usually over 15 hours) in the absence of oxygen and at room temperature

In vitro metabolism of radiolabeled carbohydrates by protective cecal anaerobic bacteria.

Science.gov (United States)

Hume, M E; Beier, R C; Hinton, A; Scanlan, C M; Corrier, D E; Peterson, D V; DeLoach, J R

1993-12-01

Cecal anaerobic bacteria from adult broilers were cultured in media containing .25% glucose or .25% lactose. Media also contained either [14C]-labeled lactose, glucose, galactose, or lactic acid as metabolic tracers. Cultures were analyzed at 4, 8, and 12 h for pH, radiolabeled and unlabeled volatile fatty acids, and lactic acid. The pH values of cultures containing .25% lactose were significantly (P galactose, lactose > glucose. The volatile fatty acids in which radiolabel was most concentrated were acetic acid, propionic acid, or butyric acid.

Studies of monoclonal antibodies IOR-CEA-1 and IOR-EGF/R3 labelled with 99mTc

International Nuclear Information System (INIS)

Dias, Carla Roberta de Barros Rodrigues

2005-01-01

Nuclear Medicine is a speciality that uses radioisotopes for the diagnosis or treatment of diseases and it is considered one of the best tools among the diagnostic modalities for detection of cancer. 99m Tc is one of the main isotopes for labelling antibodies and in Nuclear Medicine in general, due to its adequate physical properties, availability and low cost. Labelled monoclonal antibodies have shown promising results for diagnosis and therapy of cancer and their use has brought great experimental and clinical advances in the field of oncology. The main clinical applications of immunoscintigraphy with monoclonal antibodies are staging and evaluation of tumoral reappearance. The antibodies employed in this work were: OIR-CEA-1, a murine monoclonal antibody that acts directly against CEA expressed in several neoplasia in particular those from the gastrointestinal tract (colorectal cancer) and IOR-EGF/R3, a murine monoclonal antibody that binds to the external domain of EGF-R and it has been used in the diagnosis of tumors of epithelial origin. The objectives of this work were the development and optimization of the reduction and purification processes, the radiolabelling techniques and quality control procedures (radiochemical, immunoreactivity and cystein challenge) and imaging studies of monoclonal antibodies OIR-CEA-1 and IOR-EGF/R3, using the simple, fast and efficient method of direct labelling of the antibody with 99m Tc. The final results was the definition of the best conditions for the preparation of lyophilized reactive kits of OIR-CEA-1 and IOR- EGF/R3 for an efficient diagnostic application in Nuclear Medicine. The most adequate conditions for the labelling of the antibodies were: 1.0 mg Ab, 29 μL MDP, 3.0 μg Sn 2+ , 1 mL of 99m Tc and 30 min. reaction time. With these conditions the labelling yield was always higher than 95% and the maximum activity of 99m Tc was about 2220 MBq (60 mCi). The evidences of the efficiency and quality of the methods here

PET and PET/CT with radiolabeled choline in prostate cancer: a critical reappraisal of 20 years of clinical studies

Energy Technology Data Exchange (ETDEWEB)

Giovacchini, Giampiero; Giovannini, Elisabetta; Leoncini, Rossella; Riondato, Mattia; Ciarmiello, Andrea [S. Andrea Hospital, Nuclear Medicine Department, La Spezia (Italy)

2017-09-15

We here aim to provide a comprehensive and critical review of the literature concerning the clinical applications of positron emission tomography/computed tomography (PET/CT) with radiolabeled choline in patients with prostate cancer (PCa). We will initially briefly summarize the historical context that brought to the synthesis of [{sup 11}C]choline, which occurred exactly 20 years ago. We have arbitrarily grouped the clinical studies in three different periods, according to the year in which they were published and according to their relation with their applications in urology, radiotherapy and oncology. Studies at initial staging and, more extensively, studies in patients with biochemical failure, as well as factors predicting positive PET/CT will be reviewed. The capability of PET/CT with radiolabeled choline to provide prognostic information on PCa-specific survival will also be examined. The last sections will be devoted to the use of radiolabeled choline for monitoring the response to androgen deprivation therapy, radiotherapy, and chemotherapy. The accuracy and the limits of the technique will be discussed according to the information available from standard validation processes, including biopsy or histology. The clinical impact of the technique will be discussed on the basis of changes induced in the management of patients and in the evaluation of the response to therapy. Current indications to PET/CT, as officially endorsed by guidelines, or as routinely performed in the clinical practice will be illustrated. Emphasis will be made on methodological factors that might have influenced the results of the studies or their interpretation. Finally, we will briefly highlight the potential role of positron emission tomography/magnetic resonance and of new radiotracers for PCa imaging. (orig.)

Monoclonal Antibodies Against Fusicoccin with Binding Characteristics Similar to the Putative Fusicoccin Receptor of Higher Plants 1

Science.gov (United States)

Feyerabend, Martin; Weiler, Elmar W.

1987-01-01

Monoclonal antibodies were raised against fusicoccin. The toxin, linked to bovine serum albumin through its t-pentenyl moiety, served as immunogen. Hybridomas secreting anti-fusicoccin antibodies were screened by radioimmunoassay employing a novel radioactive derivative, [3H]-nor-fusicoccin-alcohol of high specific activity (1.5 × 1014Bq/mole). The two monoclonal antibodies reported here are of high apparent affinity for fusicoccin (0.71 × 10−9 molar and 1.85 × 10−9 molar). This is comparable to the apparent affinity of rabbit antiserum raised against the same type of conjugate (9.3 × 10−9 molar). A method for the single step purification of the monoclonal antibodies from ascites fluid is reported. A solid-phase immunoassay, using alkaline phosphatase as enzyme, exhibits a measuring range from 0.1 to 1.5 picomoles (about 70 picograms to 1 nanogram) of fusicoccin. The displacement of [3H]-nor-fusicoccin-alcohol from the antibodies by compounds structurally related to fusicoccin exhibits similar selectivity as a microsomal binding assay with the same tracer as radiolabeled probe. Images Fig. 2 PMID:16665786

Preparation and radiolabeling of human serum albumin (HSA)-coated magnetite nanoparticles for magnetically targeted therapy

Energy Technology Data Exchange (ETDEWEB)

Zhang Chunfu E-mail: zchunfu@yahoo.com.cn; Cao Jinquan; Yin Duanzhi; Wang Yongxian; Feng Yanlin; Tan Jiajue

2004-12-01

In this paper, we describe the preparation of human serum albumin-coated magnetic particles of about 200 nm in diameter with narrow size distribution radiolabeled with {sup 188}Re for the purpose of magnetically targeted therapy. The optimum radiolabeling conditions are: SnCl{sub 2}{center_dot}2H{sub 2}O 8 mg/ml, citric acid 20 mg/ml, vitamin C 8 mg/ml, labeling volume 500 {mu}l and a reaction time of 3 h. The stability of the radiolabeled particles is suitable for in vivo study.

Optimization of IGF-1R SPECT/CT Imaging Using In-111-Labeled F(ab ')(2) and Fab Fragments of Article the Monoclonal Antibody R1507

NARCIS (Netherlands)

Heskamp, Sandra; van Laarhoven, Hanneke W. M.; Molkenboer-Kuenen, Janneke D. M.; Bouwman, Wilbert H.; van der Graaf, Winette T. A.; Oyen, Wim J. G.; Boerman, Otto C.

2012-01-01

The insulin-like growth factor 1 receptor (IGF-1R) is a potential new target for the treatment of breast cancer. Patients with breast cancer lesions that express IGF-1R may benefit from treatment with anti-IGF-IR antibodies. IGF-1R expression can be visualized using radiolabeled R1507, a monoclonal

Enhancement by gamma-interferon of in vivo tumor radiolocalization by a monoclonal antibody against HLA-DR antigen

International Nuclear Information System (INIS)

Rowlinson, G.; Balkwill, F.; Snook, D.; Hooker, G.; Epenetos, A.A.

1986-01-01

Athymic nu/nu (nude) mice bearing s.c. human breast tumors were treated systemically with recombinant human gamma-interferon. These tumors were phenotypically negative for HLA-DR prior to therapy, but after 4 days of treatment, 80% of the cells expressed this antigen in vivo as assessed by immunoperoxidase (F. R. Balkwill et al., Eur. J. Cancer Clin. Oncol., in press, 1986). A radioiodine-labeled murine monoclonal antibody (TAL-1B5) against HLA-DR specifically localized to the tumors in recombinant human gamma-interferon-treated but not in control mice. An isotype-identical murine monoclonal antibody that did not react with control or recombinant human gamma-interferon-treated tumors did not show any specific localization. These results demonstrate that specific localization to tumors of radio-labeled monoclonal antibodies to HLA-DR can be facilitated by systemic therapy with gamma-interferon

Radiolabeling, biodistribution and tumor imaging of stealth liposomes containing methotrexate

International Nuclear Information System (INIS)

Subramanian, N; Arulsudar, N; Chuttani, K; Mishra, P; Sharma, R.K; Murthy, R.S.R

2003-01-01

To study the utility of sterically stabilized liposomes (stealth liposomes) in tumor scintigraphy by studying its biodistribution and accumulation in target tissue after radiolabeling with Technetium-99m (99mTC). Conventional and Stealth liposomes were prepared by lipid film hydration method using methotrexate as model anticancer drug. Radiolabeling of the liposomes was carried out by direct labeling using reduced 99mTc. Experimental conditions for maximum labeling yield were optimized. The stability studies were carried out to check binding strength of the radiolabeled complexes. The blood kinetic study was carried out in rabbits after giving the labeled complex by intravenous administration through ear vein. The biodistribution studies were carried out in the Ehrlich ascites tumor (EAT) bearing mice after intravenous administration through tail vein, showed prolonged circulation in blood and significant increase in the accumulation in tumor for the sterically stabilized liposomes compared to the conventional liposomes. The gamma scintigraphic image shows the distribution of the stealth liposomes in liver, spleen, kidney and tumor. The study gives precise idea about the use of stealth liposomes in tumor scintigraphy and organ distribution studies (Au)

New aspects of radioimmunochemical measurement of human parathyroid hormone using the labelled antibody technique

International Nuclear Information System (INIS)

Hesch, R.D.; McIntosh, C.H.S.; Woodhead, J.S.; Welsh National School of Medicine, Cardiff

1975-01-01

Two forms of heterogeneity of parathyroid hormone (PTH) have given rise to conflicting results: one due to the heterogeneity of the secreted species from the gland and their peripheral metabolism and the other representing the immunochemical heterogeneity of the available antibodies. We have developed sequence specific assays using the technique of labelled antibodies. Therefore, results of assays measuring the C-terminal part and the (1-34)-N-terminal part of the molecule could be compared to those of an assay for hormone bearing both N- and C-terminal antigenic determinants. This assay is supposed to detect predominantly (1-84)-intact hormone. The immunoradiometric assay of (1-34)-PTH has a sensitivity of 0.04 ng/ml. This technique avoids the critical iodination of the hormone fragment containing no tyrosine. There is the expected overlap between normal subjects and patients with primary and secondary hyperparathyroidism. The most important finding are results from patients undergoing neck catheterization. We demonstrated nonuniform secretion of different species of PTH by parathyroid adenomata and normal glands. This supports the hypothesis of cleavage of the (1-84)-molecule in the gland. (orig.) [de

A radiolabeled antiglobulin test for crossmatching platelet transfusions

International Nuclear Information System (INIS)

Kickler, T.S.; Braine, H.G.; Ness, P.M.; Koester, A.; Bias, W.

1983-01-01

Despite the use of HLA-matched platelets for alloimmunized recipients, transfusion failures occur. In order to reduce these failures, researchers investigated the use of a radiolabeled antiglobulin technique for platelet crossmatching. The principle of the test is that of an indirect Coombs test using 125 I labeled goat anti-human IgG. Incompatibility is determined by calculating a radioactivity antiglobulin test (RAGT) index. Using this technique, researchers performed 89 crossmatches on 19 leukemic or aplastic patients who were refractory to random donor platelets and receiving varying degrees of HLA-matched platelets. Effectiveness of the transfusion was assessed from the posttransfusion corrected platelet count increment (CCI) determined at 1 and 20 hr. When the RAGT index was 1.9 or less, the mean CCI at 1 lhr was 17,570 +/- 7003/cu mm, n . 55. When the RAGT index was 2.0 or greater, the mean CCI was 4237 +/- 4100/cu mm, n . 34. At 20 hr when the RAGT index was 1.9 or less, the mean CCI was 8722 +/- 3143/cu mm, n . 33, and when the index was 2.0 or greater, the mean CCI was 571 +/- 1286/cu mm, n . 23. Using this technique, one false negative resulted. Nine positive crossmatches with good increments at 1 hr were found; at 20 hr, however, the survival of these units was zero. These data suggest that this method is a useful adjunct in the selection of platelets in the refractory patient

Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

Energy Technology Data Exchange (ETDEWEB)

Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

2015-03-17

A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

Investigation of bacterial adherence to a non-precious alloy with radiolabeling method

International Nuclear Information System (INIS)

Sonugelen, M.; Iyiyapici Destan, U.; Oeztuerk, B.; Yurt Lambrecht, F.

2006-01-01

The objective of this study was to investigate the bacterial adherence to a non-precious alloy with radiolabeling method. S. mutans, E. coliand C. albicanswere labeled with 99m Tc by using stannous chloride and their radiolabeling yields were calculated. After the labeling procedure, metal disks (3 mm x 10 mm) were treated with microorganisms. The amount of labeled microorganisms adhered on metal surfaces was determined by activity measurements. The labeling yields for S. mutans, E. coliand C. albicanswere 69.95 ± 7.58%, 78.84 ± 0.44% and 79.71 ± 10.17%, respectively. The mean values for adherence for S. mutans, E. coliand C. albicans on metal samples were 7.02 ± 2.18%, 0.96 ± 0.49% and 8.80 ± 8.24%, respectively. The radiolabeling method could be considered as safe and precise for determining the adherence of microorganisms. (author)

Studies of the radiolabeling and biodistribution of substance P using lutetium-177 as a radiotracer

International Nuclear Information System (INIS)

Lima, Clarice Maria de

2011-01-01

Malignant gliomas are primary brain tumors, resistant to various treatments, as chemotherapy, radiotherapy, induction of apoptosis and surgery. An alternative for the treatment of malignant gliomas is the radionuclide therapy. This technique apply radiolabeled molecules that selectively bind to tumor cells producing cytotoxic effect by dose irradiation, and resulting in death of tumor cells. Most protocols for radionuclide therapy of malignant brain tumors involve the administration of peptides labeled with β - emitting radioisotopes. The Substance P (SP) is an 11- amino acid neuropeptide, characterized by the C-terminal sequence Phe-X-Gly-Leu-Met-NH 2 . The use of SP labeled with different radionuclides including 177 Lu, have been proposed for in vivo treatment of tumors. SP is the most important target of neurokinin 1 receptors, over expressed in malignant gliomas. The objective of this work was to study conditions of radiolabeling DOTA-SP with 177 Lu, the stability of labeled compound and in vivo and in vitro, to develop a protocol production and evaluate the potential of the radiopharmaceutical in the therapy of gliomas. The labeling conditions were optimized varying the temperature, reaction time, activity of lutetium-177 chloride and mass of DOTA-SP. The radiochemical purity of preparations were analyzed by chromatographic techniques. The stability of 17L u -DOTA- SP radiolabeled with low activity of 177 Lu was evaluated for different time at 2-8 degree C or incubated in human serum. The stability of the labeled with high activity of 177 Lu was also analyzed in the presence of gentisic acid (6 mg / mL) added after the labeling reaction. The labeled conditions in low and high activity were subjected to evaluation for the ability to cause oxidation of methionine residue, adding the D-L- methionine amino acid to the reaction medium (6 mg / mL) and subsequent chromatographic evaluation. In vitro study with 177 Lu-DOTA-SP, radiolabeled in the absence and presence

Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-99m.

Science.gov (United States)

Fuscaldi, Leonardo Lima; Dos Santos, Daniel Moreira; Pinheiro, Natália Gabriela Silva; Araújo, Raquel Silva; de Barros, André Luís Branco; Resende, Jarbas Magalhães; Fernandes, Simone Odília Antunes; de Lima, Maria Elena; Cardoso, Valbert Nascimento

2016-01-01

Current diagnostic methods and imaging techniques are not able to differentiate septic and aseptic inflammation. Thus, reliable methods are sought to provide this distinction and scintigraphic imaging is an interesting option, since it is based on physiological changes. In this context, radiolabeled antimicrobial peptides have been investigated as they accumulate in infectious sites instead of aseptic inflammation. The peptide LyeTx I, from the venom of Lycosa erythrognatha, has potent antimicrobial activity. Therefore, this study aimed to synthesize LyeTx I derivatives with the chelating compound HYNIC, to evaluate their antimicrobial activity and to radiolabel them with (99m)Tc. Two LyeTx I derivatives, HYNIC-LyeTx I (N-terminal modification) and LyeTx I-K-HYNIC (C-terminal modification), were synthesized by Fmoc strategy and purified by RP-HPLC. The purified products were assessed by RP-HPLC and MALDI-ToF-MS analysis. Microbiological assays were performed against S. aureus (ATCC® 6538) and E. coli (ATCC® 10536) in liquid medium to calculate the MIC. The radiolabeling procedure of LyeTx I-K-HYNIC with (99m)Tc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl2 (.) 2H2O), and standardized taking into account the amount of peptide, reducing agent, pH and heating. Radiochemical purity analysis was performed by thin-layer chromatography on silica gel strips and the radiolabeled compound was assessed by RP-HPLC and radioactivity measurement of the collected fractions. Data were analyzed by ANOVA, followed by Tukey test (p-values EDDA). The binding of HYNIC to the N-terminal portion of LyeTx I seems to affect its activity against bacteria. Nevertheless, the radiolabeling of the C-terminal derivative, LyeTx I-K-HYNIC, must be better investigated to optimize the radiolabeled compound, in order to use it as a specific imaging agent to distinguish septic and aseptic inflammation.

Effect of iodination site on binding of radiolabeled ligand by insulin antibodies and insulin autoantibodies

International Nuclear Information System (INIS)

Diaz, J.L.; Wilkin, T.J.

1988-01-01

Four human insulins and four porcine insulins, each monoiodinated to the same specific activity at one of the four tyrosine residues (A14, A19, B16, B26) and purified by reversed-phase liquid chromatography, were tested in a radiobinding assay against a panel of insulin-antibody (IA)-positive sera from 10 insulin-treated diabetics and insulin-autoantibody-positive (IAA) sera from 10 nondiabetics. Of the 10 IAA-positive sera, five were fully cross reactive with both insulin species, and five were specific for human insulin. The rank order of binding of sera with the four ligands from each species was random for IA (mean rank values of 1.9 for A14, 2.0 for A19, 2.5 for B16, and 3.6 for B26 from a possible ranking range of 1 to 4), but more consistent for non-human-insulin-specific IAA (mean rank values 1.3 for A14, 3.8 for A19, 1.7 for B16, and 3.2 for B26 for labeled human insulins; 1.2 for A14, 4.0 for A19, 1.8 for B16, and 3.0 for B26 for labeled porcine insulins). The rank order of binding was virtually uniform for human-insulin-specific IAA (mean values 1.2 for A14, 3.0 for A19, 1.8 for B16, and 4.0 for B26). The influence of iodination site on the binding of labeled insulin appears to be dependent on the proximity of the labeled tyrosine to the antibody binding site and the clonal diversity, or restriction, of insulin-binding antibodies in the test serum. When IA and IAA are measured, the implications of this study regarding the choice of assay ligand may be important

Application of 99mTc-labeled chimeric Fab fragments of monoclonal antibody A7 for radioimmunoscintigraphy of pancreatic cancer

International Nuclear Information System (INIS)

Matsumura, Hiroomi

1999-01-01

Pancreatic cancer is one of the most lethal diseases and its prognosis is still poor. To improve the survival rate, it is essential to develop new technologies for early and definitive diagnosis. In this study, chimeric Fab fragments of monoclonal antibody A7 were successfully radio-labeled with 99m Tc, preventing depression of the antigen-binding activity. 99m Tc-labeled monoclonal antibody A7, 99m Tc-labeled chimeric Fab fragments of monoclonal antibody A7, 99m Tc-labeled normal mouse IgG and 99m Tc-labeled Fab fragments of normal mouse IgG were injected intravenously into nude mice bearing human pancreatic cancer xenografts and the radioactivity was subsequently measured. The tumor accumulation was significantly higher with labeled monoclonal antibody A7 than with normal mouse IgG, and higher with chimeric Fab fragments of monoclonal antibody A7 than with Fab fragments of normal mouse IgG. The tumor/blood ratio of radioactivity increased rapidly over time with chimeric Fab fragments of monoclonal antibody A7. These results suggest that chimeric Fab fragments of monoclonal antibody A7 may be useful for diagnosing pancreatic cancer by means of radioimmunoscintigraphy. (author)

A study of the use of radioimmunoscintigraphy (RIA) with the monoclonal antibody MAb-170, and fluorine-18 flurodeoxyglucose positron emission tomography (18FDG-PET) for the preoperative imaging of complex ovarian masses and their ability to identify ovarian cancer

Science.gov (United States)

Lieberman, Gidon

The hypothesis for this study is whether the newer diagnostic techniques of radioimmunoscintigraphy (RIS) utilising radiolabelled monoclonal antibodies and 2-[[18]F] fluoro-2-deoxy-D-glucose ([18]FDG) imaging using a double headed gamma camera offer improvements in preoperative selection for referral of patients to Cancer Centres. Monoclonal antibody radioimmunoscintigraphy (RIS) is hindered by several factors including false positive results due to physiological excretion, concern over production of human anti-mouse antibodies (HAMA) that would prevent repeated doses and difficulty in precisely relating areas of accumulation and anatomy. [18]FDG imaging relies on the accumulation of radiolabelled sugars, and subsequent breakdown products within tumour. [18]FDG imaging with dedicated positron emission tomography has real potential, but its use is limited by large capital outlay. Newer techniques involving "dual headed cameras" (DHC) offer PET capability at a lower cost. Chapter two describes the evaluation of a monoclonal antibody (MAb-170) in 27 women who presented with suspicious pelvic masses. The preoperative clinical, radiological and radioimmunoscintigraphy findings are compared to those at surgery and subsequent histology. All 18 patients with malignant or borderline ovarian cancer were correctly identified using RIS. The overall sensitivity and specificity for all sites were 100% and 38%. RIS was particularly useful in the identification of (intra-abdominal) serosal deposits. Enzyme linked immunosorbant assay (ELISA) was used to quantify the HAMA. A strong HAMA production was seen in at least 3 patients, however HAMA response was independent of clinical parameters. Chapter three describes the immunohistochemical staining of paraffin embedded biopsy specimens from the 27 patients who underwent RIS with MAb-170. The original research into the cellular location of the specific epitope to which the antibody interacts was performed on isopentane frozen biopsies

Localisation and mechanism of renal retention of radiolabelled somatostatin analogues

Energy Technology Data Exchange (ETDEWEB)

Melis, Marleen; Krenning, Eric P.; Bernard, Bert F.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Barone, Raffaella [UCL, Centre of Nuclear Medicine and Laboratory of PET, Brussels (Belgium); Visser, Theo J. [Erasmus MC, Department of Internal Medicine, Rotterdam (Netherlands)

2005-10-01

Radiolabelled somatostatin analogues, such as octreotide and octreotate, are used for tumour scintigraphy and radionuclide therapy. The kidney is the most important critical organ during such therapy owing to the reabsorption and retention of radiolabelled peptides. The aim of this study was to investigate in a rat model both the localisation and the mechanism of renal uptake after intravenous injection of radiolabelled somatostatin analogues. The multi-ligand megalin/cubilin receptor complex, responsible for reabsorption of many peptides and proteins in the kidney, is an interesting candidate for renal endocytosis of these peptide analogues. For localisation studies, ex vivo autoradiography and micro-autoradiography of rat kidneys were performed 1-24 h after injection of radiolabelled somatostatin analogues and compared with the renal anti-megalin immunohistochemical staining pattern. To confirm a role of megalin in the mechanism of renal retention of [{sup 111}In-DTPA]octreotide, the effects of three inhibitory substances were explored in rats. Renal ex vivo autoradiography showed high cortical radioactivity and lower radioactivity in the outer medulla. The distribution of cortical radioactivity was inhomogeneous. Micro-autoradiography indicated that radioactivity was only retained in the proximal tubules. The anti-megalin immunohistochemical staining pattern showed a strong similarity with the renal [{sup 111}In-DTPA]octreotide ex vivo autoradiograms. Biodistribution studies showed that co-injection of positively charged d-lysine reduced renal uptake to 60% of control. Sodium maleate reduced renal [{sup 111}In-DTPA]octreotide uptake to 15% of control. Finally, cisplatin pre-treatment of rats reduced kidney uptake to 70% of control. Renal retention of [{sup 111}In-DTPA]octreotide is confined to proximal tubules in the rat kidney, in which megalin-mediated endocytosis may play an important part. (orig.)

Albumin-derived peptides efficiently reduce renal uptake of radiolabelled peptides

International Nuclear Information System (INIS)

Vegt, Erik; Eek, Annemarie; Oyen, Wim J.G.; Gotthardt, Martin; Boerman, Otto C.; Jong, Marion de

2010-01-01

In peptide-receptor radionuclide therapy (PRRT), the maximum activity dose that can safely be administered is limited by high renal uptake and retention of radiolabelled peptides. The kidney radiation dose can be reduced by coinfusion of agents that competitively inhibit the reabsorption of radiolabelled peptides, such as positively charged amino acids, Gelofusine, or trypsinised albumin. The aim of this study was to identify more specific and potent inhibitors of the kidney reabsorption of radiolabelled peptides, based on albumin. Albumin was fragmented using cyanogen bromide and six albumin-derived peptides with different numbers of electric charges were selected and synthesised. The effect of albumin fragments (FRALB-C) and selected albumin-derived peptides on the internalisation of 111 In-albumin, 111 In-minigastrin, 111 In-exendin and 111 In-octreotide by megalin-expressing cells was assessed. In rats, the effect of Gelofusine and albumin-derived peptides on the renal uptake and biodistribution of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide was determined. FRALB-C significantly reduced the uptake of all radiolabelled peptides in vitro. The albumin-derived peptides showed different potencies in reducing the uptake of 111 In-albumin, 111 In-exendin and 111 In-minigastrin in vitro. The most efficient albumin-derived peptide (peptide 6), was selected for in vivo testing. In rats, 5 mg of peptide 6 very efficiently inhibited the renal uptake of 111 In-minigastrin, by 88%. Uptake of 111 In-exendin and 111 In-octreotide was reduced by 26 and 33%, respectively. The albumin-derived peptide 6 efficiently inhibited the renal reabsorption of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide and is a promising candidate for kidney protection in PRRT. (orig.)

Radiolabelling of antibodies with technetium-99m and their clinical evaluation

International Nuclear Information System (INIS)

Varvarigou, A.D.

1998-01-01

Our study referred mainly to the comparative evaluation of two different methods, one direct and the other indirect, for the labelling of MoAbs with 99 Tc m . With the direct method, disulphide bridges were cleaved by the sue of 2-mercaptoethanol (2-ME), as reductant, while with the indirect method, the antibody was coupled to 2-iminothiolane (2-IM). The latter reacts with the amine groups of the protein's lysine molecules, thus creating free thiol groups, capable of binding reduced 99 Tc m . In both cases a preformed intermediate chelate was used for the 99 Tc m exchange. The 99 Tc m labelled species were analyzed by Instant Thin Layer Chromatography (ITLC), High Performance Liquid Chromatography (HPLC), and Polyacrylamide Gel Electrophoresis (PAGE). We investigated the influence of the labelling systems on MoAbs' integrity, as well as the ability of the labelled species to tag on human cancer cells. The biodistribution of the labelled derivatives was comparatively evaluated in normal male Swiss mice and the stability of labelling was measured by cysteine challenge. The in vitro stability was comparatively studied at different temperatures and by incubation with human serum for 24 h

Highly efficient method for 125I-radiolabeling of biomolecules using inverse-electron-demand Diels-Alder reaction.

Science.gov (United States)

Choi, Mi Hee; Shim, Ha Eun; Yun, Seong-Jae; Kim, Hye Rim; Mushtaq, Sajid; Lee, Chang Heon; Park, Sang Hyun; Choi, Dae Seong; Lee, Dong-Eun; Byun, Eui-Baek; Jang, Beom-Su; Jeon, Jongho

2016-04-19

In this report, we present a rapid and highly efficient method for radioactive iodine labeling of trans-cyclooctene group conjugated biomolecules using inverse-electron-demand Diels-Alder reaction. Radioiodination reaction of the tetrazine structure was carried out using the stannylated precursor 2 to give 125 I-labeled azide ([ 125 I]1) with high radiochemical yield (65±8%) and radiochemical purity (>99%). For radiolabeling application of [ 125 I]1, trans-cyclooctene derived cRGD peptide and human serum albumin were prepared. These substrated were reacted with [ 125 I]1 under mild condition to provide the radiolabeled products [ 125 I]6 and [ 125 I]8, respectively, with excellent radiochemical yields. The biodistribution study of [ 125 I]8 in normal ICR mice showed significantly lower thyroid uptake values than that of 125 I-labeled human serum albumin prepared by a traditional radiolabeling method. Therefore [ 125 I]8 will be a useful radiolabeled tracer in various molecular imaging and biological studies. Those results clearly demonstrate that [ 125 I]1 will be used as a valuable prosthetic group for radiolabeling of biomolecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clearance of a monoclonal anti-DNA antibody following administration of DNA in normal and autoimmune mice

International Nuclear Information System (INIS)

Jones, F.S.; Pisetsky, D.S.; Kurlander, R.J.

1986-01-01

To study the assembly of DNA-anti-DNA complexes in vivo, we have measured the clearance from blood and organ localization of a murine IgG2a monoclonal anti-DNA antibody, called 6/0, following the infusion of DNA intravenously or intraperitoneally. Intraperitoneal DNA caused a profound acceleration of 6/0 anti-DNA clearance that was dose dependent and demonstrable after the infusion of as little as 1.9 microgram per gram of body weight of single-stranded DNA. The antibody was cleared primarily in the liver without increased deposition in the kidney. Intraperitoneal infusions of DNA also accelerated the clearance of 6/0 in autoimmune MRL-lpr/lpr mice. In contrast, intravenous DNA given in comparable doses caused only a slight increase in 6/0 antibody clearance; this accelerated clearance was seen only at low antigen doses and only during the first 10 min following DNA infusion. Using double-radiolabeling techniques, 6/0 and Cl.18, an IgG2ak myeloma protein without anti-DNA activity, were found to disappear from blood at a comparable rate in both B6D2 mice and MRL-lpr/lpr mice. These results suggest that the DNA-anti-DNA immune complexes can form in vivo but that this process is profoundly affected by the manner in which DNA enters the circulation. In addition, the results suggest that DNA-dependent clearance is not a major pathway for anti-DNA metabolism in normal or at least one strain of autoimmune mice

The role of radiolabelled compounds in preclinical drug development

International Nuclear Information System (INIS)

Hawkins, D.R.

1988-01-01

The role of radiolabelled compounds in the development of new drugs is discussed, with particular reference to their use in toxicological, metabolic and pharmacokinetic studies for the pre-clinical safety evaluation of new drugs. (U.K.)

Topographic antigenic determinants recognized by monoclonal antibodies on human choriogonadotropin beta-subunit

International Nuclear Information System (INIS)

Bidart, J.M.; Troalen, F.; Salesse, R.; Bousfield, G.R.; Bohuon, C.J.; Bellet, D.H.

1987-01-01

We describe a first attempt to study the antibody-combining sites recognized by monoclonal antibodies raised against the beta-subunit of human choriogonadotropin (hCG). Two groups of antibodies were first defined by their ability to recognize only the free beta-subunit or the free and combined subunit. Antibodies FBT-11 and FBT-11-L bind only to hCG beta-subunit but not to hCG, whereas antibodies FBT-10 and D1E8 bind to both the beta-subunit and the hormone. In both cases, the antigenic determinants were localized to the core of the protein (residues 1-112), indicating the weak immunogenicity of the specific carboxyl-terminal extension of hCG-beta. Nine synthetic peptides spanning different regions of hCG-beta and lutropin-beta were assessed for their capacity to inhibit antibody binding. A synthetic peptide inclusive of the NH2-terminal region (residues 1-7) of the hCG beta-subunit was found to inhibit binding to the radiolabeled subunit of a monoclonal antibody specific for free hCG-beta (FBT-11). Further delineation of the antigenic site recognized by this antibody provided evidence for the involvement of fragment 82-92. Moreover, monoclonal antibody FBT-11 inhibited the recombination of hCG-beta to hCG-alpha, indicating that its antigenic determinant might be located nearby or in the hCG-beta portion interacting with the alpha-subunit. Binding of monoclonal antibody FBT-10, corresponding to the second antigenic determinant, was weakly inhibited by fragment 82-105 and did not impair the recombination of the hCG beta-subunit to the hCG alpha-subunit. Its combining site appeared to be located in a region of the intact native choriogonadotropin present at the surface of the hormone-receptor complex

The effects of variations in the specificities of the antibody components on a two-site immunoradiometric assay for ferritin

International Nuclear Information System (INIS)

Cowan, S.I.; Stagg, B.H.; Niemann, E.

1977-01-01

Variations in the sub-unit antigenic structure of ferritins derived from various human tissues are reflected in the differing specificities of antisera raised against these ferritin preparations. In this study it was shown that antibody specificity played an important role in determining the sensitivity and overall binding of labelled antibody in a two-site immunoradiometric assay for ferritin. Homologous assay systems, in which solid phase and radiolabelled antibodies were of similar specificities, were generally less sensitive and showed lower binding than heterologous assay systems, in which solid phase and labelled antibodies were of different specificities. The source of the ferritin which was used as assay standard also played an important part in determining the sensitivity and overall binding in homologous antibody systems, spleen ferritin standards yielding assays superior to those obtained with placenta or liver ferritin standards. However, these differences between standards were not seen in a heterologous system employing solid phase antibodies directed against liver ferritin and labelled antibodies directed against placenta ferritin. The nature of the ferritin used to prepare immunoadsorbant for the purification of antibodies prior to radioiodination also affected the assay characteristics; antibodies prepared on spleen ferritin immunoadsorbant being more reactive than antibodies prepared on placenta ferritin immunoadsorbant, which in turn were more reactive then antibodies prepared on liver ferritin immunoadsorbant. (orig.) [de

Towards Translational ImmunoPET/MR Imaging of Invasive Pulmonary Aspergillosis: The Humanised Monoclonal Antibody JF5 Detects Aspergillus Lung Infections In Vivo

DEFF Research Database (Denmark)

Davies, Genna; Rolle, Anna-Maria; Maurer, Andreas

2017-01-01

and magnetic resonance imaging (immunoPET/MRI) using a [64Cu] DOTA-labeled mouse monoclonal antibody (mAb), mJF5, specific to Aspergillus. To enable translation of the tracer to the clinical setting, we report here the development of a humanised version of the antibody (hJF5), and pre-clinical imaging of lung...... of the fungus from invasive lung biopsy, considered the gold standard for IPA detection, is slow and often not possible in critically ill patients. In a previous study, we reported the development of a novel non-invasive procedure for IPA diagnosis based on antibody-guided positron emission tomography...... infection using a [64Cu] NODAGA-hJF5 tracer. The humanised antibody tracer shows a significant increase in in vivo biodistribution in A. fumigatus infected lungs compared to its radiolabeled murine counterpart [64Cu] NODAGA-mJF5. Using reverse genetics of the pathogen, we show that the antibody binds...

Combined radioimmunoassay for triiodothyronine and thyroxine

International Nuclear Information System (INIS)

Denning, C.E.; Schick, L.A.

1980-01-01

A method for the combined radioimmunoassay for the hormones triiodothyronine (T-3) and thyroxine (T-4) in serum or plasma, wherein the radiolabeled t-3 and t-4 reagents are t-3 and t-4 labeled with the same radioisotope. The hormones are extracted from the serum or plasma sample and separated from their binding proteins by adsorption to a crosslinked dextran gel at a highly alkaline ph. After washing away the dissociated proteins, a predetermined limiting amount of t-3 antibody is incubated with the gel and thereafter radiolabeled t-3 which has become extracted from the gel by antibody binding is washed away. Excess t-3 antibody and a predetermined limiting amount of t-4 antibody are then incubated with the gel and radiolabeled t-3 and t-4 which has become extracted from the gel by antibody binding are thereafter washed away. The respective relative amounts of radiolabeled t-3 and t-4 retained by the gel after the incubations with the respective limiting amounts of t-3 and t-4 antibody are compared with standard results to quantitate the hormones in the sample. The use of excess t-3 antibody in the t-4 antibody incubation is critical to the accuracy of the method, enabling the use of the same radioisotope for radiolabeling t-3 and t-4

Cardiac lymphoscintigraphy following closed-chest catheter injection of radiolabeled colloid into the myocardium of dogs: concise communication

International Nuclear Information System (INIS)

Osbakken, M.D.; Kopiwoda, S.Y.; Swan, A.; Castronovo, F.P.; Strauss, H.W.

1982-01-01

A catheter technique for injection of radiolabeled colloids into the myocardium was developed and tested in a series of 15 dogs. A multipurpose angiographic catheter was modified to permit an inner core of PE-50 polyethylene tubing, tipped with a 23-gage needle, to pass through the lumen for intra-myocardial injection of the femoral artery: for the right ventricle, the femoral vein. The catheter advanced under fluoroscopy until the desired surface for injection is reached. The inner core is then extended to lodge the needle in the endocardium. A mixture of Renogratin (to confirm the endocardial injection site) and radiolabeled colloid was injected in up to 6 hr. In three dogs the procedure was repeated 3 or 4 times. From two to five nodes were visible in all animals, irrespective of whether the right or left ventricular myocardium was injected. In two animals the injection was given intravenously, and no nodes were seen. These data suggest that cardiac lymphatic drainage can be studied with a catheter injection method

In vitro and in vivo motility studies of radiolabelled sperm cells

International Nuclear Information System (INIS)

Balogh, L.; Szasz, F.; Janoki, Gy.A.; Toth, L.; Zoldag, L.; Huszenicza, Gy.

1994-01-01

A new method for radiolabelling of sperm cells with 99m Tc HM-PAO (hexamethyl-propylene-amine-oxide) - LEUCO-SCINT kit, is investigated. The labelling technique for fresh rabbit, bull, sheep and horse as well as frozen-thawed bull sperm was optimized. The optimum conditions for sperm cell labelling (incubation volume, incubation time, initial activity of 99m Tc HM-PAO, cell number) yielded a high labelling efficiency (70-80%) and survival rate (50-60%). The labelled sperm cells were used to study their motility in vitro. The migrating at 37 o C cells incubated capillary tubes containing bovine cervical mucus. The tubes were cut and the activity of the parts measured and valued. We compared the results of living and killed sperm cells and the label alone by the change of species and running time. Ten minutes after the labelling procedures the total activity of microtubes was 2-3 times higher and the activity distribution was different from the results obtained 3 hours after the labelling. The sperm migration in vivo in the living female animals using a non invasive technique was also visualized. The sperm flow was clearly demonstrated in 3 different animal model (rabbit, ewe, hen) under gamma camera. The comparison of the in vivo migration of rabbit and bull sperm cells showed that the homologous sperm migrated faster and farther. On study of bull sperm migration in the ewe genital tract the cornu uteri was clearly visualized. In the hen model the whole genital tract was demonstrated with considerable free activity in the cavum abdominal 24 hours after the artificial insemination. The new method is developed and manufactured by NRIRR, Budapest, originally designed for radiolabelling leucocytes. The 99m Tc HM-PAO Labelled sperm cells with their retained migration properties are suitable for in vitro motility assays and in vitro migration studies in both human and veterinary medicine. (author)

Kinetics of intralymphatically delivered monoclonal antibodies

International Nuclear Information System (INIS)

Wahl, R.L.; Geatti, O.; Liebert, M.; Beers, B.; Jackson, G.; Laino, L.; Kronberg, S.; Wilson, B.S.; Beierwaltes, W.H.

1985-01-01

Radiolabeled monoclonal antibody (MoAb) administration subcutaneously (sq), so that preferential uptake is to the lymphatics, holds significant promise for the detection of lymph node metastases. Only limited information is available about clearance rates of intralymphatically administered MoAbs. I-131 labeled intact IgG (225.28S), F(ab's)2 (225.28S) or IgM (FT162) were administered sq to anesthetized Balb/C mice. Eight mice were studied with each MoAb, 4 with a foot-pad injection, 4 with an anterior abdominal injection. Gamma camera images were collected into a computer, over the first 6 hrs after injection with the animals anesthetized and immobile. Animals were then allowed to move about freely. Additional images were then acquired out to 48 hrs. Regions of interest wre selected over the injection site and the kinetics of antibody egress determined. Clearance rates from local sq injection sites are influenced by motion and somewhat by location. The class and fragment status of the MoAb appear relatively less important in determining clearance rates from sq injections than they are in determining whole-body clearance after iv injections. Additional studies using Fab fragments and additional monoclonals will be useful in extending these observations

Demonstration of two distinct antigenic determinants on hepatitis B e antigen by monoclonal antibodies

International Nuclear Information System (INIS)

Imai, M.; Nomura, M.; Gotanda, T.; Sano, T.; Tachibana, K.; Miyamoto, H.; Takahashi, K.; Toyama, S.; Miyakawa, Y.; Mayumi, M.

1982-01-01

Mice were immunized against hepatitis B e antigen (HBeAg) isolated from sera of asymptomatic carriers of hepatitis B virus. Their spleen cells were fused with mouse myeloma (NS-1) cells, and 5 clones of hybridoma cells secreting antibody against HBeAg (anti-HBe) were isolated. For the production of anti-HBe in large scale, cells were cultivated both in vitro and in the peritoneal cavity of ascitic mice. Although monoclonal antibodies produced by these clones showed a strong reactivity of anti-HBe in hemagglutination tests, individual monoclonal anti-HBe did not reveal any precipitin line in immunodiffusion. When 2 of the 5 monoclonal antibodies were mixed together, however, some combinations showed a precipitin line against HBeAg, whereas others did not. Utilizing solid-phase radioimmunoassay involving a number of combinations of monoclonal antibodies used for solid-phase and radiolabeling, the 5 antibodies were classified into 2 groups. Three of the anti-HBe antibodies were found to be directed to 1 determinant of HBeAg (determinant a); the remaining 2 to the other determinant (determinant b). Determinants a and b were detected on HBeAg in the serum, as well as on the polypeptide of 19,000 daltons (P19) derived from the nucleocapsid of hepatitis B virus. Monoclonal anti-HBe antibodies with different specificities may provide useful tools in delineating the antigenic structure of HBeAg and also in evaluating immune responses of the host directed to its subdeterminants

Technetium-99 labelling of DD-3B6/22 antifibrin monoclonal antibody fragmented Fab' for thrombus imaging

International Nuclear Information System (INIS)

Lee, F-T.; Boniface, G.R.; Lambrecht, R.M.; Rylatt, D.B.; Bundesen, P.G.

1993-01-01

The antifibrin DD-3B6/22 monoclonal antibody Fab' fragment, a murine immunoglobulin, IgG3, has been labelled with technetium-99m ( 99mTc ) via a transchelation reaction, to specific activity in excess of 30 mCi/mg protein. The radiolabelling of Fab' was dependent on time, temperature, pH, antibody concentrations and nature intermediary transchelation complex used. The resultant radioconjugate was stable in vitro and in vivo. Blood clearance of 99m Tc-Fab' in rat followed two compartment kinetics with the half time of the fast phase being 0.5 h. The main route of excretion was via the kidneys with little uptake indicated by other tissues. The results suggest that the inherent specificity of the antibody, small molecular size, rapid plasma clearance, high specific radioactivity, together with the physical properties of the 99m Tc label, combine to make this labelled monoclonal antibody (MoAb), potentially suitable as a radiopharmaceutical for the scintigraphic detection of thrombi in humans. 17 refs., 3 tabs., 5 figs

An Alternate, Egg-Free Radiolabeled Meal Formulation for Gastric-Emptying Scintigraphy.

Science.gov (United States)

Garrigue, Philippe; Bodin-Hullin, Aurore; Gonzalez, Sandra; Sala, Quentin; Guillet, Benjamin

2017-07-01

Tc-radiolabeled scrambled eggs (SEs) are most often used as the ingested solid phase for gastric-emptying scintigraphy, leading egg-reluctant patients to avoid the examination. We formulated and validated 2 egg-free alternate meals, in the absence of any commercialized formulation: chocolate mug cake (MC) and scrambled tofu (ST). Six healthy volunteers underwent gastric-emptying scintigraphy after ingesting Tc-radiolabeled MC, ST, or SE. Gastric retention indexes did not change significantly between formulations (% of overtime variation to SE: MC 7.75% ± 7.1%, ST 7.17% ± 5.8%; P = 0.6618, not statistically significant), suggesting MC and ST as interesting egg-free alternatives.

Synthesis of fluorine-18 radio-labeled serum albumins for PET blood pool imaging

International Nuclear Information System (INIS)

Basuli, Falguni; Li, Changhui; Xu, Biying; Williams, Mark; Wong, Karen; Coble, Vincent L.; Vasalatiy, Olga; Seidel, Jurgen; Green, Michael V.; Griffiths, Gary L.; Choyke, Peter L.; Jagoda, Elaine M.

2015-01-01

We sought to develop a practical, reproducible and clinically translatable method of radiolabeling serum albumins with fluorine-18 for use as a PET blood pool imaging agent in animals and man. Fluorine-18 radiolabeled fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [ 18 F]F-Py-TFP was prepared first by the reaction of its quaternary ammonium triflate precursor with [ 18 F]tetrabutylammonium fluoride ([ 18 F]TBAF) according to a previously published method for peptides, with minor modifications. The incubation of [ 18 F]F-Py-TFP with rat serum albumin (RSA) in phosphate buffer (pH 9) for 15 min at 37–40 °C produced fluorine-18-radiolabeled RSA and the product was purified using a mini-PD MiniTrap G-25 column. The overall radiochemical yield of the reaction was 18–35% (n = 30, uncorrected) in a 90-min synthesis. This procedure, repeated with human serum albumin (HSA), yielded similar results. Fluorine-18-radiolabeled RSA demonstrated prolonged blood retention (biological half-life of 4.8 hours) in healthy awake rats. The distribution of major organ radioactivity remained relatively unchanged during the 4 hour observation periods either by direct tissue counting or by dynamic PET whole-body imaging except for a gradual accumulation of labeled metabolic products in the bladder. This manual method for synthesizing radiolabeled serum albumins uses fluorine-18, a widely available PET radionuclide, and natural protein available in both pure and recombinant forms which could be scaled up for widespread clinical applications. These preclinical biodistribution and PET imaging results indicate that [ 18 F]RSA is an effective blood pool imaging agent in rats and might, as [ 18 F]HSA, prove similarly useful as a clinical imaging agent

Synthesis of fluorine-18 radio-labeled serum albumins for PET blood pool imaging.

Science.gov (United States)

Basuli, Falguni; Li, Changhui; Xu, Biying; Williams, Mark; Wong, Karen; Coble, Vincent L; Vasalatiy, Olga; Seidel, Jurgen; Green, Michael V; Griffiths, Gary L; Choyke, Peter L; Jagoda, Elaine M

2015-03-01

We sought to develop a practical, reproducible and clinically translatable method of radiolabeling serum albumins with fluorine-18 for use as a PET blood pool imaging agent in animals and man. Fluorine-18 radiolabeled fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [(18)F]F-Py-TFP was prepared first by the reaction of its quaternary ammonium triflate precursor with [(18)F]tetrabutylammonium fluoride ([(18)F]TBAF) according to a previously published method for peptides, with minor modifications. The incubation of [(18)F]F-Py-TFP with rat serum albumin (RSA) in phosphate buffer (pH9) for 15 min at 37-40 °C produced fluorine-18-radiolabeled RSA and the product was purified using a mini-PD MiniTrap G-25 column. The overall radiochemical yield of the reaction was 18-35% (n=30, uncorrected) in a 90-min synthesis. This procedure, repeated with human serum albumin (HSA), yielded similar results. Fluorine-18-radiolabeled RSA demonstrated prolonged blood retention (biological half-life of 4.8 hours) in healthy awake rats. The distribution of major organ radioactivity remained relatively unchanged during the 4 hour observation periods either by direct tissue counting or by dynamic PET whole-body imaging except for a gradual accumulation of labeled metabolic products in the bladder. This manual method for synthesizing radiolabeled serum albumins uses fluorine-18, a widely available PET radionuclide, and natural protein available in both pure and recombinant forms which could be scaled up for widespread clinical applications. These preclinical biodistribution and PET imaging results indicate that [(18)F]RSA is an effective blood pool imaging agent in rats and might, as [(18)F]HSA, prove similarly useful as a clinical imaging agent. Published by Elsevier Inc.

Use and limitations of radiolabelled anti-CEA antibodies and their fragments for photoscanning detection of human colorectal carcinomas

Energy Technology Data Exchange (ETDEWEB)

Mach, J P; Forni, M; Ritschard, J; Buchegger, F; Carrel, S; Widgren, S; Donath, A; Alberto, P [Lausanne Univ. (Switzerland)

1980-08-01

Fifty-three patients with histologically proven carcinoma were injected with highly purified (/sup 131/I)-labelled goat antibodies or fragments of antibodies against carcinoembryonic antigen (CEA). Each patient was tested by external photoscanning 4, 24, 36, 48h after injection. In 22 patients (16 of 38 injected with intact antibodies, 5 of 13 with F(ab')/sub 2/ fragments and 1 of 2 with Fab' fragments), an increased concentration of /sup 131/I radioactivity corresponding to the previously known tumor location was detected by photoscanning 36-48 h after injection. Blood pool and secreted radioactivity was determined in all patients by injecting 15 min after scanning, (sup(99m)Tc)-labeled normal serum albumin and free sup(99m)TcO/sub 4//sup -/. The computerized subtraction of sup(99m)Tc from /sup 131/I radioactivity enhanced the definition of tumor localization in the 22 positive patients. However, in spite of the computerized subtraction, interpretation of the scans remained doubtful for 12 patients and was entirely negative for 19 additional patients.

Dose-dependent variations in blood flow evaluation of canine nerve, nerve graft, tendon, and ligament tissue by the radiolabeled-microsphere technique

International Nuclear Information System (INIS)

Riggi, K.; Wood, M.B.; Ilstrup, D.M.

1990-01-01

This study evaluates the dose-dependent accuracy of the radionuclide-labeled microsphere technique for blood flow evaluation in nerve, tendon, and ligament. In eight dogs, blood flows were determined for nerve, nerve graft, tendon, and ligament tissue by simultaneous injection of high- and low-dose microspheres with different radiolabels. The results demonstrated no significant differences in blood flow as measured from the small number of microspheres (less than 400) and the high number (more than 400) for nerve and tendon tissue. For nerve tissue, microsphere counts of 50 to 100, 100 to 200, 200 to 300, and more than 300 produced mean percentage errors of 12.74% (n = 5, SEM = 4.52), 5.45% (n = 13, SEM = 1.22), 10.22% (n = 6, SEM = 4.37), and 17.08% (n = 12, SEM = 3.30), respectively. For tendon tissue, the same microsphere subdivisions had mean percentage errors of 7.47% (n = 4, SEM = 2.66), 3.63% (n = 6, SEM = 1.34), 15.54% (n = 4, SEM = 4.43), and 12.91% (n = 1), respectively. For ligament tissue, percentage errors were consistently higher; microsphere counts of 30 to 100, 100 to 200, and 200 to 300 produced mean errors of 20.14% (n = 4, SEM = 6.38), 18.66% (n = 4, SEM = 6.24), and 25.78% (n = 2, SEM = 1.97), respectively. Although there was no direct relationship between percentage error and number of microspheres retrieved, we suggest that microsphere counts in the range of 100 to 200 should be considered acceptable for nerve and tendon in the canine. Ligament tissue seems to be less well suited to the microsphere technique; however, further study is warranted

Effect of highly radiolabelled 2,4-dinitrochlorobenzene (DNCB) on experimental DNCB contact dermatitis in guinea pigs

Energy Technology Data Exchange (ETDEWEB)

Filipp, G [Red Cross Clinic, Dept. of Clinical Immunology and Allergology, Saarbruecken; Biro, G [2. Medical Clinic, Medical School, University of Saarland, Homburg/Saar; Bahmer, F [Clinic of Dermatology, Medical School, University of Saarland, Homburg/Saar; Mitschke, H [Institute of Pathology, Municipal Academic Hospital, Winterberg, Saarbruecken; Lehmann, G [Dept. of Analytical and Biological Chemistry, University of Saarland, Saarbruecken, Federal Republic of Germany

1984-01-01

With the aid of epicutaneous application of 2,4-dinitrochlorobenzene (DNCB) solution in acetone, we induced a cutaneous allergic reaction of the delayed type. Our question was whether the development of the DNCB cutaneous sensitivity could be suppressed by highly radiolabelled DNCB. On the basis of the clonal selection theory and our own results with other in vivo-experimental animal models, one could suppose that the highly radiolabelled DNCB as haptens binds to the Ig-membrane receptors of the genetically determined T-lymphocyte clone, and that the conjugated radioactivity (/sup 125/I) causes a selective radioactive damage to this competent T-lymphocyte subpopulation. By means of intracardially applied radiolabelled DNCB, we are able to induce either complete or very significant suppression of the cutaneous DNCB immune response. In the second experiment, the highly radiolabelled DNCB was not able to inhibit sensitization to a simultaneously applied 4-ethoxy-methylene-2-phenyl-oxazolone (oxazolone). This result clearly demonstrates the antigen specificity of this form of immune suppression.

Effect of highly radiolabelled 2,4-dinitrochlorobenzene (DNCB) on experimental DNCB contact dermatitis in guinea pigs

International Nuclear Information System (INIS)

Filipp, G.; Biro, G.; Bahmer, F.; Mitschke, H.; Lehmann, G.

1984-01-01

With the aid of epicutaneous application of 2,4-dinitrochlorobenzene (DNCB) solution in acetone, we induced a cutaneous allergic reaction of the delayed type. Our question was whether the development of the DNCB cutaneous sensitivity could be suppressed by highly radiolabelled DNCB. On the basis of the clonal selection theory and our own results with other in vivo-experimental animal models, one could suppose that the highly radiolabelled DNCB as haptens binds to the Ig-membrane receptors of the genetically determined T-lymphocyte clone, and that the conjugated radioactivity ( 125 I) causes a selective radioactive damage to this competent T-lymphocyte subpopulation. By means of intracardially applied radiolabelled DNCB, we are able to induce either complete or very significant suppression of the cutaneous DNCB immune response. In the second experiment, the highly radiolabelled DNCB was not able to inhibit sensitization to a simultaneously applied 4-ethoxy-methylene-2-phenyl-oxazolone (oxazolone). This result clearly demonstrates the antigen specificity of this form of immune suppression. (author)

Two-dimensional analysis of metabolically and cell surface radiolabeled proteins of some human lymphoid and myeloid leukemia cell lines. II. Glycosylated and phosphorylated proteins

Energy Technology Data Exchange (ETDEWEB)

Chorvath, B; Duraj, J; Sedlak, J; Pleskova, I

1986-01-01

Cell surface glycoproteins, radiolabelled by the sodium metaperiodate/tritiated borohydride technique, and cell phosphoproteins, metabolically radiolabelled with /sup 32/P-orthophosphate were analyzed by two-dimensional electrophoretic analysis in some myeloid and lymphoid leukemia cell lines. Some markedly expressed major glycoproteins were predominant in some of the cell lines (such as 95k and 100k glycoproteins with marked charge heterogeneity in non-T, non-B acute lymphoblastic leukemia cell lines NALM 6 and NALM 16), but markedly quantitatively reduced in other examined cell lines, such as lymphoblastoid cell line UHKT 34/2. /sup 32/P-orthophosphate radiolabelled phosphoprotein two-dimensional patterns of the examined lymphoid leukemia cell lines were essentially similar, with some minor differences, in examined lymphoid and myeloid leukemia cell lines, such as marked expression of a series of large phosphoproteins in the molecular weight range 80-100k in lymphoid cell lines and almost complete absence of these phosphoproteins on the examined myeloid leukemia cell lines. Another configuration of acidic phosphoproteins (30-35k) exhibited individual cell line variability and differences between both individual myeloid leukemia cell lines and between the lymphoid and myeloid cell lines examined. (author) 2 figs., 15 refs.

Radiolabeled microsphere measurements of alveolar bone blood flow in dogs

International Nuclear Information System (INIS)

Kaplan, M.L.; Jeffcoat, M.K.; Goldhaber, P.

1978-01-01

Radiolabeled microspheres were injected into the left cardiac ventricle in healthy adult dogs to quantify blood in maxillary and mandibular alveolar bone. Heart rate, arterial blood pressure and pulse contour were monitored throughout each experiment. Blood flow in maxillary alveolar bone was more than 30 % greater (p<.001) than in mandibular alveolar bone. Alveolar bone blood flow (mean +- S.D.) measured as ml/min per gram was 0.12 +- .02 in the maxilla compared to 0.09 +- .02 in the mandible. The cardiovascular parameters monitored were constant immediately prior to the injection of microspheres and remained unchanged during and following injection. It is possible that radiolabeled microspheres can be used to quantify the circulatory changes in alveolar bone during the development of destructive periodontal disease in dogs. (author)

Monitoring radiolabelled antacid preparations in the stomach

International Nuclear Information System (INIS)

May, H.A.; Wilson, C.G.; Hardy, J.G.

1984-01-01

Radiolabelled antacid preparations have been monitored in the stomach using gamma scintigraphy. The stomach contents were labelled with technetium-99m and two antacid preparations with indium-113m. It has been shown that the antacid containing aluminium hydroxide and magnesium oxide mixed and emptied with the other stomach contents. An alginate containing preparation tended to float on the food and emptied only slowly from the stomach. (Auth.)

Current status and future perspectives of in vivo small animal imaging using radiolabeled nanoparticles

International Nuclear Information System (INIS)

Loudos, George; Kagadis, George C.; Psimadas, Dimitris

2011-01-01

Small animal molecular imaging is a rapidly expanding efficient tool to study biological processes non-invasively. The use of radiolabeled tracers provides non-destructive, imaging information, allowing time related phenomena to be repeatedly studied in a single animal. In the last decade there has been an enormous progress in related technologies and a number of dedicated imaging systems overcome the limitations that the size of small animal possesses. On the other hand, nanoparticles (NPs) gain increased interest, due to their unique properties, which make them perfect candidates for biological applications. Over the past 5 years the two fields seem to cross more and more often; radiolabeled NPs have been assessed in numerous pre-clinical studies that range from oncology, till HIV treatment. In this article the current status in the tools, applications and trends of radiolabeled NPs reviewed.

Monoclonal anti-elastin antibody labelled with technetium-99m

International Nuclear Information System (INIS)

Oliveira, Marcia B.N. de; Silva, Claudia R. da; Araujo, Adriano C. de; Bernardo Filho, Mario; Porto, Luis Cristovao M.S.; Gutfilen, Bianca; Souza, J.E.Q.; Frier, Malcolm

1999-01-01

Technetium-99m ( 99m Tc) is widely employed in nuclear medicine due to its desirable physical, chemical and biological properties. Moreover, it is easily available and normally is inexpensive. A reducing agent is necessary to label cells and molecules with 99m Tc and stannous chloride (Sn C L 2 ) is usually employed. Elastin is the functional protein component of the elastic fiber and it is related with some diseases such as arteriosclerosis, pulmonary emphysema and others. The present study refers to the preparation of the 99m Tc labeled monoclonal anti-elastin antibody. The monoclonal antibody was incubated with an excess of 2-iminothiolane. The free thiol groups created, were capable of binding with the reduced technetium. Labeling was an exchange reaction with 99m Tc-glucoheptonate. The labeled preparation was left at 4 deg C for one hour. Then, it was passed through a Sephadex G50 column. Various fractions were collected and counted. A peak corresponding to the radiolabeled antibody was obtained. Stability studies of the labelled anti-elastin were performed at 0,3 6, 24 hours, at both 4 deg C or room temperature. The biodistribution pattern of the 99m Tc-anti-elastin was studied in healthy male Swiss mice. The immunoreactivity was also determined. An useful labeled-anti-elastin was obtained to future immunoscintigraphic investigations. (author)

Radioiodination of antibodies for tumor imaging

International Nuclear Information System (INIS)

Saha, G.B.

1983-01-01

In view of the great potential of radioiodinated antibody for the detection and treatment of cancer, the present article deals with the various techniques of radioiodination of antibody and their uses. Topics include methods of iodination of antibody, advantages and disadvantages of different methods, and effects of radioiodination on the antibody molecules with respect to their physiochemical and immunologic reactivity. In addition, the clinical usefulness of radioiodinated antibodies is discussed. (Auth.)

Kinetics of platelets in dogs with thrombocytopenia induced by antiglycoprotein IIb/IIIa receptor monoclonal antibody

International Nuclear Information System (INIS)

Hosono, Makoto; Sone, Naoaki; Endo, Keigo; Saga, Tsuneo; Kobayashi, Hisataka; Hosono, Masako N.; Sakahara, Harumi; Yasunaga, Kojiro; Konishi, Junji

1995-01-01

To experimentally assess the kinetics of platelets in thrombocytopenia, we constructed a canine model using 111 In-oxine labeled autologous platelets and an intact antiplatelet monoclonal antibody (MAb) NNKY2-11 (IgG2a). With the infusion of radiolabeled autologous platelets into dogs, the peripheral platelet count and blood radioactivity level were examined, and the radioactivity in the liver, spleen and heart was determined with scintigraphic analysis. Thereafter, i.v. injection of 100 μg/kg of NNKY2-11 had no effect on platelet counts or the biodistribution of radiolabeled platelets. However, 200 and 300 μg/kg of MAb reduced the platelets, and the radioactivity of the liver and spleen augmented clearly after injection of MAb. Platelet radioactivity in serum, which had decreased after MAb infusion, did not recover, even when peripheral platelet counts returned to the normal levels, indicating that these new platelets might be derived from the platelet-storage pool or new thrombocytogenesis. This model of antiplatelet MAb induced thrombocytopenia seems to be useful for analyzing the kinetics of platelets in thrombocytopenia

Detection of metastatic tumor in normal-sized retroperitoneal lymph nodes by monoclonal-antibody imaging

International Nuclear Information System (INIS)

Moldofsky, P.J.; Sears, H.F.; Mulhern, C.B. Jr.; Hammond, N.D.; Powe, J.; Gatenby, R.A.; Steplewski, Z.; Koprowski, H.

1984-01-01

Detection of metastatic colon carcinoma is reported in retroperitoneal lymph nodes that were visible but normal in size (less than 1 cm) and number on CT scanning and at surgery. A case history is presented of 1 of 27 patients with colon carcinoma, metastatic or primary, evaluated with intravenously administered, radiolabeled monoclonal-antibody fragments and subsequent nuclear medicine imaging. Images of /sup 99m/Tc-labeled red cells corresponding to each [ 131 I]antibody view of the abdomen were obtained as a control, to avoid interpretation of simple blood-pool radioactivity as specific localization of antibody on tumor. Antibody images were evaluated both without and with computer blood-pool image substraction. Directed to the level of the left renal hilum by the antibody scan, the surgeon removed the largest palpable node, which measured slightly less than 1 cm in diameter and was not palpably or visibly abnormal to the surgeon until it was removed and sectioned. Pathological evaluation of frozen and permanent sections revealed microscopic foci of adenocarcinoma consistent with a colonic primary tumor. Immunoperoxidase staining for the 1083-17-1A colorectal-carcinoma antigen demonstrated the presence of the antigen in the lymph node. As a result of the detection of this metastasis outside the liver, the patient did not receive the planned hepatic-artery chemotherapy pump but instead received intravenous chemotherapy

Radiolabeling of HTE1PA: A new monopicolinate cyclam derivative for Cu-64 phenotypic imaging. In vitro and in vivo stability studies in mice

International Nuclear Information System (INIS)

Frindel, Mathieu; Camus, Nathalie; Rauscher, Aurore; Bourgeois, Mickaël; Alliot, Cyrille; Barré, Louisa; Gestin, Jean-François; Tripier, Raphaël; Faivre-Chauvet, Alain

2014-01-01

Introduction: HTE1PA, a monopicolinate-N-alkylated cyclam-based ligand has previously demonstrated fast complexation process, high kinetic inertness and important thermodynamic and electrochemical stability with respect to natural copper. In this work we first developed a new synthetic route to obtain HTE1PA in good yields. Then, we investigated HTE1PA chelation properties towards copper-64 and assessed in vitro and in vivo stability of the resulting compound. Methods: Radiolabeling of HTE1PA with copper-64 was tested at different ligand concentrations in ammonium acetate medium. In vitro stability study was carried out by incubating [ 64 Cu]TE1PA complex in human serum at both 37 °C and 4 °C; chromatographic controls were performed over 24 h. Biodistribution, pharmacokinetic and hepatic metabolism of [ 64 Cu]TE1PA were conducted in BALC/c mice in comparison with [ 64 Cu]acetate and [ 64 Cu]DOTA, used as a reference ligand. Results: The promising results obtained for natural copper complexation were confirmed. HTE1PA was quantitatively radiolabeled in 15 min at room temperature. The resulting complex showed high serum stability. [ 64 Cu]TE1PA induced a significant uptake in the liver and kidneys at early biodistribution time point. Nevertheless, a high speed wash out was observed at 24 h leading to significantly lower uptake into the liver compared to [ 64 Cu]DOTA. The metabolism study was consistent with a high resistance to transchelation as the initial uptake into liver matches with the intact form of [ 64 Cu]TE1PA. Conclusion: Despite the partial elimination of HTE1PA – as copper-64 complex – through the hepatic route, its high selectivity for copper and its resistance to transchelation make it a promising ligand for antibody radiolabeling with either copper-64 or copper-67

Evaluation of tumor targeting with radiolabeled F(ab2 fragment of a humanized monoclonal antibody

Directory of Open Access Journals (Sweden)

"Babaei MH

2002-08-01

Full Text Available Humanized monoclonal antibody U36 and its F(ab'2 fragment, radio labeled with 125I, were tested for tumor localization in nude mice bearing a squamous cell carcinoma xenograft line derived from a head and neck carcinoma. Monoclonal antibody IgG or F(ab'2 fragment were injected in parallel and at days 1, 2 and 3, mice were dissected for determination of isotope biodistribution. IgG as well as F(ab'2 showed highly specific localization in tumor tissue. The mean tumor uptake (n=3 is expressed as the percentage of the injected dose per gram of tumor tissue (%ID/g. %ID/g of IgG was 11.7% at day 1 and decreased to 10.9% at day 3 whereas %ID/g of F(ab'2 was 2.9% at day 1 and decreased on following days. Tumor to blood ratios (T/B at day 1 were 0.86 for IgG and 1.32 for F(ab'2 and reached a maximum at day 3 with values of 4.41 and 1.84 respectively. These findings suggest that the superior tumor to non-tumor ratios in the day of 1 render the F(ab'2 fragment more qualified for specific targeting radioisotopes to tumor xenografts in this exprimental setting.

Technetium-99m radiolabeling of a recombinant dermonecrotic protein (recLiD1) from the Loxosceles venom for biodistribution study

International Nuclear Information System (INIS)

Valadares, D.; Felicori, L.; Olortegui, C.C.; Simal, C.; Gouvea dos Santos, R.

2007-01-01

In the present study the recombinant form (recLiD1) of a dermonecrotic protein present in the Brazilian brown spider Loxosceles intermedia venom was labeled with technetium-99m using stannous chloride and sodium borohydride as reducing agents. 99mTc-recLiD 1 kept its biological activity evoking dermonecrotic activity in rabbits. In vivo biodistribution in mice with the radiolabeled recLiD 1 showed high kidney uptake followed by stomach and liver uptakes. Also, we can see that 20% of toxin remaining in the skin after 120 min and once absorbed, 99mTc-recLiD 1 is rapidly cleared from the blood with long-lasting. We also observed one displacement of 99mTc-recLiD 1 by one monoclonal antibody raised against L. intermedia venom that indicates specific interaction with kidney tissue. (author)

Cardiac lymphoscintigraphy following closed-chest catheter injection of radiolabeled colloid into the myocardium of dogs: concise communication

International Nuclear Information System (INIS)

Osbakken, M.D.; Kopiwoda, S.Y.; Swan, A.; Castronovo, F.P.; Strauss, H.W.

1982-01-01

A catheter technique for injection of radiolabeled colloids into the myocardium was developed and tested in a series of 15 dogs. A multipurpose angiographic catheter was modified to permit an inner core of PE-50 polyethylene tubing, tipped with a 23-gage needle, to pass through the lumen for intra-myocardial injection of radiocolloids. For injection of the left ventricle, the catheter is introduced through the femoral artery: for the right ventricle, the femoral vein. The catheter advanced under fluoroscopy until the desired surface for injection is reached. The inner core is then extended to lodge the needle in the endocardium. A mixture of Renografin (to confirm the endocardial injection site) and radiolabeled colloid was injected in 13 animals. Ten minutes after injection, scintigraphy was begun and continued for up to 6 hr. In three dogs the procedure was repeated 3 or 4 times. From two to five nodes were visible in all animals, irrespective of whether the right or left ventricular myocardium was injected. In two animals the injection was given intravenously, and no nodes were seen. These data suggest that cardiac lymphatic drainage can be studied with a catheter injection method

Antibodies to poliovirus detected by immunoradiometric assay with a monoclonal antibody

International Nuclear Information System (INIS)

Spitz, M.; Fossati, C.A.; Schild, G.C.; Spitz, L.; Brasher, M.

1982-01-01

An immunoradiometric assay (IRMA) for the assay of antibodies to poliovirus antigens is described. Dilutions of the test sera or whole (finger prick) blood samples were incubated with the poliovirus antigen bound to a solid phase and the specific antibody was detected by the addition of a mouse anti-human IgG monoclonal antibody (McAb), which was itself revealed by iodinated sheep IgG antimouse F(ab). The authors have shown that this technique is suitable for the estimation of IgG anti-poliovirus antibodies induced in children following polio vaccine. The present study shows that SPRIA provides a simple and inexpensive method for serological studies with poliovirus particularly for use in large-scale surveys. (Auth.)

Antibodies to poliovirus detected by immunoradiometric assay with a monoclonal antibody

Energy Technology Data Exchange (ETDEWEB)

Spitz, M.; Fossati, C.A.; Schild, G.C.; Spitz, L.; Brasher, M. (National Inst. for Biological Standards and Control, London (UK))

1982-10-01

An immunoradiometric assay (IRMA) for the assay of antibodies to poliovirus antigens is described. Dilutions of the test sera or whole (finger prick) blood samples were incubated with the poliovirus antigen bound to a solid phase and the specific antibody was detected by the addition of a mouse anti-human IgG monoclonal antibody (McAb), which was itself revealed by iodinated sheep IgG antimouse F(ab). The authors have shown that this technique is suitable for the estimation of IgG anti-poliovirus antibodies induced in children following polio vaccine. The present study shows that SPRIA provides a simple and inexpensive method for serological studies with poliovirus particularly for use in large-scale surveys.

Preparation of human cardiac anti-myosin: a review

International Nuclear Information System (INIS)

Okada, H.; Souza, I.T.T.

1990-01-01

The present communication is a review of the physicochemical characterization and immunological properties of myosin isolated from the cardiac muscle, the production of monoclonal antibody anti-myosin, the radiolabeling of this antibody and its applications as radiopharmaceuticals to imaging myocardial infarcts. The classical example of radioimmunologic diagnosis of non malignant tissues is the detection of myocardial infarction by radiolabeled antibodies to myosin. (author)

Development of 90Sr/90Y Generator Systems Based on SLM Techniques for Radiolabelling of Therapeutic Biomolecules with 90Y. Chapter 14

International Nuclear Information System (INIS)

Thu, N.T.; Van Dong, D.; Van Cuong, B.; Van Khoa, C.; Cam Hoa, V.T.

2015-01-01

Yttrium-90 is one of the most useful radionuclides for radioimmunotherapeutic applications, especially for labelling peptides and antibodies. Studies were carried out to develop a 90 Sr/ 90 Y generator system based on the SLM technique. Two stages of 90 Sr/ 90 Y generator systems were developed at different activity levels of 5, 20, 50 and 100 mCi and operated with semiautomation in sequential mode. In the first stage of the system, PC88A based SLM was used, which transported 90 Y from a nitric acid medium containing 0.01–4M HNO 3 . In the second stage, the 90 Y from the first stage was transferred to the first compartment of the second stage using carbamoylmethyl phosphine oxide (CMPO) based SLM where 1M acetic acid was used as the receiving phase for 90 Y. Quality control was carried out for the products of 90 Y using EPC with paper chromatography and Tec control chromatography. Peptides and antibodies were labelled using the 90 Y product obtained from the generator developed in house. (author)

(99m)Tc-aprotinin - optimisation and validation of radiolabelling kits for routine preparation for diagnostic imaging of amyloidosis

DEFF Research Database (Denmark)

Denholt, Charlotte; Gillings, Nic

2016-01-01

Technetium-99m aprotinin was prepared from an optimised radiolabelling kit formulation containing aprotinin, alkaline buffer and stannous chloride (reducing agent) and radiolabelled using (99m) Tc-pertechnetate. The labelling was achieved within 25 min, with radiochemical purities of >98%....

Uptake of radiolabeled leukocytes in prosthetic graft infection

International Nuclear Information System (INIS)

Serota, A.I.; Williams, R.A.; Rose, J.G.; Wilson, S.E.

1981-01-01

The utility of radionuclide labeled leukocytes in the demonstration of infection within vascular prostheses was examined. The infrarenal aorta was replaced with a 3 cm Dacron graft in 12 dogs. On the third postoperative day, six of the animals received an intravenous injection of 10(8) Staphylococcus aureus. Labeled leukocyte scans were performed at postoperative days one and three, and then weekly for 8 weeks with indium-111 and technetium-99 labeled autologous leukocytes. When scans showed focal uptake of isotope in the area of prosthetic material, the grafts were aseptically excised and cultured on mannitol-salt agar. Both control and infected animals had retroperitoneal isotope activity in the immediate postoperative period that disappeared by the end of the first week. By the eighth postoperative week, all of the animals that received the bacteremic challenge had both radionuclide concentration in the region of the vascular prosthesis and S. aureus cultured subsequently from the perigraft tissues. None of the control animals had either radionuclide or bacteriologic evidence of infection at the eighth postoperative week. The radiolabeled leukocyte scan is a highly sensitive and specific technique, clinically applicable for the diagnosis of vascular prosthetic infections

Therapeutic Recombinant Monoclonal Antibodies

Science.gov (United States)

Bakhtiar, Ray

2012-01-01

During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

Correlation of antispermatozoal antibody with infertility in immunized female rabbits using 14C-protein A in a filter radioassay

International Nuclear Information System (INIS)

Eng, L.A.; Metz, C.B.

1986-01-01

The meaningful detection of antisperm antibody in immunologically infertile females has been confounded by the many methods of assay that exist. With many of these methods there is poor correlation of assay results with infertility. In this report, female rabbits were rendered partially or completely infertile by immunization with sperm fractions. A filter radioassay for antisperm antibody was developed that consists of incubating 10(7) sperm with sperm from immunized rabbits and 14 C-Protein A, a long-lived and versatile indirect radiolabel for many antibodies of the IgG class. The spermatozoa are washed by rapid vacuum filtration on polycarbonate membrane filters instead of by time-consuming centrifugation. The filters with the collected spermatozoa are then counted in a liquid scintillation counter. Sera from female rabbits isoimmunized with sperm antigens show a highly significant correlation (r = -0.904; p less than 0.001) between assay results and infertility as measured by the percentage of eggs that underwent cleavage after artificial insemination

Approaches in the design of 99mTc based peptide radiolabelling for tumour targeting

International Nuclear Information System (INIS)

Yokoyama, A.; Horiuchi, K.; Arano, Y.

2001-01-01

One of the major drawbacks in diagnostic and/or therapeutic uses of peptides radiolabelled with radiometals via bifunctional chelating agents (BCA) is their accumulation in excretory organs such as liver or kidney. Thus, the aim of the project is centred in the search for chemical and radiochemical approaches to reduce radioactivity accumulated in excretory organs while preserving the in vivo receptor binding affinity of the peptide. During the first stage a suitable procedure using the F-moc-chemistry (solid phase) was developed and synthesis of DTPA-D-Phen1-Octreotide and DTPA-L-Phen1-Octreotide was carried out. During the synthesis, the need to improve the yield demanded the synthesis of a DTPA derivative holding only one reactive carboxylic group to avoid side intermolecular reaction. The availability of both isomeric conjugated octreotide led to their radiolabelling with 111 In. Their metabolic studies in animals indicated that the degradation rate of the peptide containing the natural aminoacid, 111 In DTPA-L-Phen1-Octreotide, was slightly higher than the corresponding D-aminoacid derivative, as expected. Stability of the peptide during radiolabelling with 99m Tc was then studied, requiring the use of variable agents such as ascorbic acid, dithionite and stannous ion. The selected peptide, RC-160, was provided by the IAEA and, as reference compounds, corresponding iodinated and radioiodinated peptides were synthesized. Demonstration of the stability of the peptide was carried out using disodium 2-nitro-5-thiosulfobenzoate (NTBS) and the lack of Bunte salt formation served as an indication of the stability of the disulfide bond under various mild conditions required for the future radiolabelling with 99m Tc. The knowledge gained served in moving to the next stage of 99m Tc radiolabelling using HYNIC as the BCA and tricine as co-ligands. The biodistribution studies demonstrated great accumulation on excretory organs. This led us to look for a model protein