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Biomedical subjects

K Hahn

Publications and source records attributed to K Hahn.

At least 235 records · Page 13Linked to original sources
PubMed1986

New nuclear medical technologies for pediatrics.

Nuclear medicine is very helpful for pediatric diagnostics because it provides noninvasive methods for the evaluation of physiologic functions and for the imaging of tumours, metastases and inflammatory diseases. These examinations can be done with very low risk and with low radiation burden for the children. New technologies help us to get more detailed diagnostic information and to reduce further the radiation. The most important developments in this field allow the clinical use of radioisotopes with extremely short lifetimes combined with a very low radiation exposure, imaging of tumours by new radioactive labelled tumour-markers, the measurement of heart functions and blood flow through the use of computerized gammacameras with digital imaging processing capabilities and the three-dimensional imaging of radioactive tracers within the body.

Child↗
PubMed1985

Comparison of 131I-metaiodobenzylguanidine scintigraphy with urinary and plasma catecholamine determinations in the diagnosis of pheochromocytoma.

In a retrospective study of 31 patients with suspected pheochromocytoma we examined the preoperative results of 131I-metaiodobenzylguanidine (131-I-MIBG) scintigraphy and a fluorimetric urine catecholamine determination test. An additional radioenzymatic plasma catecholamine determination test was performed in 25 patients. In 14 of the 31 patients the diagnosis of pheochromocytoma was later histologically confirmed. In the remaining 17 patients the suspected diagnosis was finally rejected after a clinical decision had been made on the basis of clinical history, symptoms, laboratory and imaging tests. 131-I-MIBG scintigraphy apparently had a very high specificity (no false-positive results among the patients with rejected diagnosis), but showed the least sensitivity (3 of 14 tumours were not detected). Urine catecholamines showed two false-negative and three false-positive results. Plasma catecholamines had the highest sensitivity and gave only one false-positive result. Because of its high pathognomonic value 131-MIBG scintigraphy can be helpful not only for localization, but also for confirmation of diagnosis when catecholamine determination tests are contradictory. On the basis of our experience with false-positive results after interfering medication therapy, urine and plasma catecholamine determination tests should only be carried out after purification with thin layer chromatography or high performance liquid chromatography.

3-Iodobenzylguanidine↗
PubMed1985

Cyclophosphamide and cisplatinum combination chemotherapy for the treatment of epithelial ovarian carcinoma.

A review of 18 patients with Stage III epithelial ovarian carcinoma treated by surgery and followed by cyclophosphamide and cisplatinum combination chemotherapy is presented. At the end of 12 months from the initiation of chemotherapy, 88.9% of the patients were alive and 77.8% remained free of tumor progression. At the end of 2 years 77.8% of the patients were alive and 44.4% of the patients were free of tumor progression. The combination of cyclophosphamide and cisplatinum has low toxicity, a simple pattern of administration, and has provided satisfactory results.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Autoimmune thyroiditis in manic-depressive patients treated with lithium.

To explore whether lithium-induced hypothyroidism is related to an exacerbation of underlying autoimmune processes such as thyroiditis, the authors comprehensively assessed thyroid function in 16 manic-depressive patients. Each of the three patients who showed detectable titers of thyroid microsomal antibodies before treatment manifested a marked increase in antibody titer from 4 to 12 months after lithium treatment was begun. Thus, lithium-induced thyroid dysfunction may not only involve direct effects on the thyroid itself but also involve exacerbation of an underlying indolent autoimmune thyroiditis, possibly by causing shifts in T lymphocyte subpopulations.

Acute Disease↗
PubMed1983

[Oral TRH stimulation in patients with thyroid carcinoma].

In patients with differentiated thyroid carcinoma high serum TSH-levels enhance 131 J-uptake in thyroid remnant and/or metastases. An effective increase of TSH could be achieved by oral administration of thyrotropin releasing hormone (TRH) even after a short T4/T3-withdrawal period so that we recommend a TRH-stimulation in all patients before a diagnostic or therapeutic 131 J-application. Adverse reactions to TRH are infrequent and usually short timed so that in contrast to TSH-stimulation--TRH can be given to outpatients without any risk.

Administration, Oral↗
PubMed1982

[Imaging adrenergic tumours with 131J-meta-benzylguanidine].

Pheochromocytoma scanning using 131J-meta-benzylguanidine was done in one patient with metastasizing paraganglioma, one patient with multiple endocrine neoplasia type IIb. No activity of tumour tissue could be demonstrated in the patient with metastasizing paraganglioma, whereas the pheochromocytoma could be clearly defined in the patient with multiple endocrine neoplasia type IIa. The female with multiple endocrine neoplasia type IIb showed a suspect space-occupying lesion of the left adrenal using computed tomography. Pheochromocytoma could be excluded by 131J-benzylguanidine scanning, selective estimation of catecholamines in adrenal venous blood as well as the glucagon stimulation and clonidine suppression.

Adrenal Gland Neoplasms↗
PubMed1982

[The psoriatic bone manifestation].

Besides the known joint involvement as seen in the whole-body scan which uses 99m technetium-phosphate-complexes, skeletal scintigraphic investigations in 17 patients with psoriasis have demonstrated circumscribed or diffuse accumulative pathological concentrations of the radionuclide within the skeleton of the skull, the thyroid cartilage, the bony thorax and osseous long bones. These pathological accumulations of radionuclides of TcP-complexes which are distant from joint regions, point to proliferative phenomena in the bone in case of psoriasis especially in alterations of the collagenous metabolism.

Adult↗
PubMed1982

The effects of chlorotrianisene (Tace) of kinetics of 3H-testosterone metabolism in patients with carcinoma of the prostate.

Alterations in the metabolism of testosterone and plasma levels of testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH), prolactin and oestradiol were studied in 6 patients with newly diagnosed prostatic carcinoma before and during treatment with chlorotrianisene at a daily dosage of 48 mg for 14 days. Parameters of plasma kinetics were determined according to the single injection technique and the 2-compartment model, and the plasma hormones by radioimmunoassay. Chlorotrianisene altered neither plasma levels of testosterone, gonadotrophins, prolactin and oestradiol, nor metabolic clearance rate, production rate and other kinetic parameters of testosterone. Thus the beneficial effects which have been reported previously cannot be explained by suppression of peripheral testosterone metabolism.

Aged↗
PubMed1981

[The diagnosis of the Pendred syndrome in children by the perchlorate discharge test with 123I (author's transl)].

A modified method for the diagnosis of the Pendred Syndrome in children by the Perchlorate discharge test using 123I is described. The older child, who has the Pendred Syndrome and the obligatory hearing deficit, frequently has neither a goitre nor hypothyroidism, but other investigations (bone growth, scars and function tests) can also show changes. However a more certain diagnosis of this disorder in children is possible by the Perchlorate discharge test using 123I. The test using 131I is no longer justified in the face of more recent radiobiological knowledge.

Child↗
PubMed1980

[The radiation dose to the foetus during isotope investigations of the mother].

The radiation dose to the foetus from the application of five different 99mTechnetium compounds during isotope investigation of the mother was investigated. After i-v injection of 100 muCi (3.7 MBq) of 99mTc-compounds into pregnant rats, these were sacrificed during the first, second and third week of pregnancy and radioactivity was determined in the foetuses and in the blood and organs of the mother. From these measurements the proportion of total body activity in individual organs and their specific activity was calculated. From this data the radiation burden to the rat foetuses from the various 99mTc compounds could be evaluated. Making use of phantom studies and the known biokinetic data of technetium compounds in man it was possible to calculate the radiation dose to the human foetus during isotope investigations of the mother.

Animals↗
PubMed1980

[Bone scintigraphy in psoriasis (author's transl)].

Since 1973 bone scintigraphy using 99mTc-phosphate-complexes was carried out in 382 patients with psoriasis. For comparison with the results of nuclear medicine, roentgenologic and clinical findings a group of 121 patients with psoriasis aged between 11 and 74 years was compared to a group of 42 patients aged between 20 and 49 years without roentgenologic and clinical signs of psoriatic arthritis. We found by means of isotope investigation that an essentially greater part of the bones adjacent to the joints was involved than was expected according to X-ray and clinical findings. In addition, in 205 patients with psoriasis whole-body scintigraphy, using 99mTc-MDP, was carried out sine 1977/78. In 17 patients we found an increased accumulation of activity in the region of extraarticular structures of the skull as well as of the skeletal thorax. According to these results we conclude that in addition to the clinically and roentgenologically defined psoriatic arthritis in patients with psoriasis and osteopathy may exist, which can only be demonstrated by skeletal scintigraphy and which is localized in bones adjacent to the joints but can also be demonstrated in the region of extraarticular bones.

Adolescent↗