Biomedical subjects

K Seybold

Publications and source records attributed to K Seybold.

14 recordsLinked to original sources

PubMed1992

Immunoscintigraphy of infections using 123I and 99mTc-labeled monoclonal antibodies. Advanced experiences in 230 patients.

Advanced experiences show an extremely high diagnostic potential in immunoscintigraphy of infections using monoclonal antigranulocytes antibodies (Mab). There was no hampering of the biological properties of the granulocytes after in vivo labeling with 123I or 99mTc-tagged Mabs. There were mostly identical findings and an equal functional behavior of the granulocytes observed with the use of different agents. Diagnosis of infections was made mostly within four to six hours p.i. 99mTc labeling is more advantageous than 123I because of better image quality, constant availability, and lower costs. 123I Mab 47 seems to be recommended in some cases of chronic osteomyelitis and spondylitis. No relevant antigenicity was observed in follow-up studies of testing HAMA serum levels. Only a few short-time reactions were seen after repeated administration of 99mTc Mab. There were no side effects and no allergic or adverse reactions. Despite these methodical advantages of the immunoscintigraphic detection of infectious and inflammatory lesions, this method should be further restricted to severe cases or patients in whom other methods would not be practicable or have failed. HAMA controls are continued in all our patients undergoing immunoscintigraphy.

Antibodies↗

PubMed1990

White blood cell scintigraphy. Problems related to the use of monoclonal antibodies.

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Antibodies, Monoclonal↗

PubMed1989

Non-homogeneous intrahepatic drug distribution in intraportal infusional chemotherapy demonstrated by Tc-99m-MAA perfusion SPECT.

Perioperative adjuvant cytotoxic chemotherapy given through a portal vein catheter may reduce the incidence of metachronous liver metastases following curative resection of colorectal carcinoma. It has generally been assumed that positioning the tip of the catheter in the stem of the portal vein will ensure homogeneous drug distribution to the whole liver. This hypothesis has been put to the test in 10 patients receiving intraportal chemotherapy according to protocol 40/81 of the Swiss Group of Clinical Cancer Research. Catheter position in the stem of the portal vein was checked angiographically the first and last day of a 7-day chemotherapy course. Perfusion scans using 99m-Tc-MAA made during therapy were compared to static liver scans obtained with 99m-Tc sulfur colloid one day after conclusion of chemotherapy. The results were evaluated on planar scans and by SPECT. Slow infusion of the tracer substance under conditions duplicating those of cytotoxic drug infusion used in the protocol resulted in decreased or missing perfusion of the left liver lobe and gross non-homogeneous perfusion in nearly all of the patients.

Aged↗

PubMed1988

Immunoscintigraphic localization of inflammatory lesions: concept, radiolabelling and in vitro testing of a granulocyte specific antibody.

Current nuclear medicine techniques for the localization of inflammatory processes are based on injection of 111In labelled autologous granulocytes which need to be isolated and radiolabelled in vitro before reinjection. A new technique is presented here that obviates the need for cell isolation by the direct intravenous injection of a granulocyte specific 123I labelled monoclonal antibody. In this publication the basic parameters of the antibody granulocyte interaction are described. Antibody binding does not inhibit vital functions of the granulocytes, such as chemotaxis and superoxide generation. Scatchard analysis of binding data reveals an apparent affinity of the antibody for granulocytes of 6.8 X 10(9) l/mol and approximately 7.1 X 10(4) binding sites per cell. Due to the high specificity of the antibody, the only expected interference is from CEA producing tumors.

Animals↗

PubMed1988

Immunoscintigraphic localization of inflammatory lesions: clinical experience.

This clinical study was based on the experimental results reported in the two preceding papers, showing that the highly selective affinity of the 123I-anti-CEA monoclonal antibody 47 (123I-Mabgc) for human granulocytes makes this compound suitable for the immunoscintigraphic detection of inflammatory lesions. Forty five patients with suspected infections have been studied after infusion of 4 mCi (148 MBq) 123I-Mabgc corresponding to 120 micrograms labeled protein. No adverse reactions have been seen. Because of the high number of labeled cells, the quality of the images was excellent. SPECT was performed in 15 cases in order to define the extent of the lesion. Infectious foci were usually seen 3-5 h postinjection, but the unimpaired function of the granulocytes guarantees diagnostically relevant examinations over a much longer period of time. Scans were read as being negative if no pathological accumulation of activity was detected after 24 h. The new scanning method is technically easy to perform and provides distinct advantages over other techniques necessitating in vitro labeling of the white blood cells. Therefore, recommended indications are acute infections of unknown origin or extent, especially recurrent episodes of osteomyelitis and infections of joint prostheses.

Adolescent↗

PubMed1988

Immunoscintigraphic localization of inflammatory lesions: pharmacokinetics and estimated absorbed radiation dose in man.

Five patients with inflammatory lesions received anti-granulocytes murine monoclonal antibody (Mabgc) infused over 5 to 15 min at doses between 3.4 and 5.4 mCi 123I (120 micrograms antibody). Clearance of 123I from blood pool closely fits a biexponential mathematical model with the two effective half-lives 0.73 h and 9.3 h. The spontaneous release of 123I was found to be relatively low in the blood pool. The cumulative urinary excretion of the 123I label over 120 h was in the range of 63% of the totally administered dose and is assumed to represent only a low molecular compound or 123I alone as iodide. Analysis of the label in spleen, liver and red marrow showed that the concentration of label in these tissues remains more or less constant over a period of 20 h after infusion. With data of liver, spleen, red marrow and whole body activity over a period of 24 h, an estimated radiation dose was calculated. Compared with 111In labelled leucocytes, especially in spleen, the absorbed dose is lower by a factor of ten per examination.

Animals↗

PubMed1988

In vivo labelling of granulocytes using 123I-tagged anti-granulocyte antibodies.

On the basis of previous work with various monoclonal antibodies (Mab) raised against carcino-embryonic antigen (CEA), the anti-CEA Mab 47 was identified which selectively reacted with a surface glycoprotein (95 kDa; NCA 95) of normal human granulocytes. This new tracer was quality tested and radioiodinated with 123I (123I Mab 47) for clinical use according to established procedures. Extended in vitro studies revealed a high selectivity for granulocytes without inhibiting their vital functions. In vivo cell binding to the granulocyte pool was completed very rapidly and remained unchanged over 24 h. For clinical use one dose consisting of 120 mcg of Mab was labelled with 4-5 mCi of 123I. Clinical interest was mainly concentrated on cases of osteomyelitis, infected allografts and abdominal and brain abscesses. After injection of 123I Mab 47, infectious lesions were usually seen after 3-5 h or could be excluded after 24 h. Because of high counting rates the image quality was excellent and single photon emission computerized tomography (SPECT) could be performed for an exact topographical localization of the lesions. No adverse reactions have been seen. It is concluded that there are distinct advantages of the new method compared with scanning of 111In-labelled leucocytes. However, despite this and the low dose of antibodies administered, we recommend restriction of immunoscintigraphy of infectious lesions before a clinically relevant immunization can be excluded.

Adult↗

PubMed1986

Imaging of inflammatory and infectious lesions after injection of radioiodinated monoclonal anti-granulocytes antibodies.

Successful detection of inflammatory lesions by planar scintigraphy and SPECT after injection of iodine-123 labelled monoclonal antibodies directed against human granulocytes (123I-Mabgc) is demonstrated. This new tracer has been compared with indium-111 labelled white blood cells (111In-WBC) in selected patients with proven infectious lesions. Scans were equally positive in all cases, but the methodical advantages of the new marker were obvious, namely, there is no need for cell separation and the images of inflammatory lesions were better defined. In addition, SPECT could be performed with 123I-Mabgc and allowed a better anatomic localization and a three-dimensional description of the lesions. No adverse reactions have been seen. It is concluded, therefore, that 123I-Mabgc is a promising agent for the detection of acute focal inflammatory lesions which may, with advantages, replace 111In-WBC.

Antibodies, Monoclonal↗

PubMed1985