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Biomedical subjects

M Fjälling

Publications and source records attributed to M Fjälling.

36 records · Page 2Linked to original sources
PubMed1995

The chemical nature, purity and stability of 99mTc-N-(2,6-Diethyl-3-iodo-phenylcarbamoylmethyl)-iminodiacetic acid.

The chemical purity and stability of a radio pharmaceutical 99mTc-N-(2,6-diethyl-3-iodo-phenylcarbamoylmethyl)-iminodiacetic acid (IODIDA) has been studied using HPLC. The HPLC results indicate that IODIDA decomposed into at least three species after 99mTc labelling, and the amount of these varied with time. Mass spectra obtained by negative ion FABMS of no-carrier-added (NCA) Tc-labelled IODIDA showed, in addition to the molecular ion and the sodium adduct of N-(2,6-diethyl-3-iodo-phenylcarbamoylmethyl)-iminodiacetic acid, peaks corresponding to sodium containing dimers, trimers and tetramers. Several peaks were also found that may be assigned to 99Tc(I) containing dimers, trimers and tetramers.

Chromatography, High Pressure Liquid↗
PubMed1995

Indium-111 activity concentration in tissue samples after intravenous injection of indium-111-DTPA-D-Phe-1-octreotide.

METHODS: Indium-111 activity concentrations in human tumor and normal tissue samples were determined at 24, 48 and 120 hr after i.v. injection of 111In-DTPA-D-Phe-1-octreotide. Fourteen patients were included in the study. Seven patients had medullary thyroid carcinoma, four had midgut carcinoid tumors, two had endocrine pancreatic tumors and one had chronic pancreatitis. RESULTS: For midgut carcinoids, the tumor-to-blood ratio was 51:220, for medullary thyroid carcinoma 4:39, and for two endocrine pancreatic tumors 6 and 1500. Tumor-to-muscle ratios varied between 1 and 1200 and tumor-to-fat between 2 and 1500 depending on tumor type. CONCLUSION: The sometimes extremely high tumor-to-normal tissue ratios present the possibility for use of radiolabeled octreotide for radiation therapy of somatostatin receptor positive tumors.

Abdominal Neoplasms↗
PubMed1994

Clinical efficacy of octreotide scintigraphy in patients with midgut carcinoid tumours and evaluation of intraoperative scintillation detection.

111In-diethylenetriamine penta-acetate-D-Phe1-octreotide scintigraphy was evaluated in a group of 27 patients with disseminated midgut carcinoid tumour. Additional information gained by the intraoperative use of a scintillation detector was studied in five patients with midgut carcinoid tumours and in two with endocrine pancreatic tumours. In 19 patients tumours not recognized by non-invasive radiological methods were visualized in 27 locations, most commonly in liver and para-aortic lymph nodes. Three false-negative tumour locations were noted (ovarian and peritoneal). With guidance from scintigraphic findings, nine patients underwent surgical tumour reduction, leading to complete remission in three. Clinically suspect tumour lesions were measured by the detector in situ, and ex vivo after excision. After excision the tissue:blood activity concentration ratios were calculated. In situ measurements were helpful in the localization of tumours and in the control of adequate clearance of tumour tissue. High tissue:blood activity concentration ratios at 1, 2 and 5 days in the five patients with midgut carcinoid tumour indicate a potential role for radiation therapy with radiolabelled octreotide in patients with somatostatin receptor-positive tumours.

Carcinoid Tumor↗
PubMed1992

Kupffer cell and hepatocyte function in rat transplanted liver.

The liver consists essentially of two compartments, parenchymal cells (PC) and non parenchymal cells (NPC) i. e. Kupffer cells, endothelial cells, fat storing cells and pit cells. PC remain after transplantation but NPC are eventually exchanged with host cells. Dynamic liver scintigraphy with albumin colloid, extracted by NPC, and IODIDA, extracted by PC, were tested to evaluate function as determined by clearance rates in these two cellular compartments. Experimental liver transplantation was performed in 15 syngeneic rats. Following transplantation, we performed dynamic liver scintigraphy with 0.5 ml 5 MBq 99mTc-Nanocoll and 0.5 ml 20 MBq 99mTc-IODIDA, 10 s per frame, 30 min for each examination. Percentage clearance rate, per minute was calculated from uptake curves over the liver. Uptake curves were nearly exponential and clearance rates could be estimated from a logarithmic plot of uptake versus time. The clearance rate was 25 +/- 4% per min (mean +/- SD) for NPC and 32 +/- 15% per min for PC in controls. After liver transplantation it was 31 +/- 7% per min for NPC and 30 +/- 15% per min for PC. Dynamic liver scintigraphy with 99mTc-Nanocoll and 99mTc-IODIDA alloweds a separate assessment of the function of PC and NPC after experimental liver transplantation in rats.

Animals↗
PubMed1988

Early diagnosis of and surgical strategy for adrenal medullary disease in MEN II gene carriers.

Sixteen multiple endocrine neoplasia type II (MEN II) gene carriers--12 who had undergone thyroidectomy because of medullary carcinoma of the thyroid and 4 whose thyroid glands had been removed because of C cell hyperplasia--were examined for the presence of pheochromocytomas. No patient had sought medical advice for pheochromocytoma symptoms. Fourteen patients had MEN IIa syndromes, one patient had a MEN IIb and another patient had a mixed syndrome of von Recklinghausen's neurofibromatosis and MEN II. Eight patients had undergone unilateral adrenalectomy for pheochromocytoma 11 +/- 4 years before. The patients underwent clinical examination, determination of the urinary excretion of catecholamines and metabolites, and 131I-metaiodobenzylguanidine (131I-MIBG) and CAT scans. 131I-MIBG scanning was performed with images 1, 4, and 7 days after the radionuclide injection. In seven of eight patients who had undergone unilateral adrenalectomies, the 131I-MIBG scans showed accumulation of the radionuclide in the remaining adrenal gland. Bilateral adrenal accumulation of the radionuclide was demonstrated in seven of eight MEN IIa gene carriers who had not undergone adrenalectomy. Five patients, two of whom had undergone adrenalectomy, were found to have unilateral pheochromocytomas less than 2 cm in diameter. Only one of these five patients had an elevated excretion of urinary catecholamines. Between day 4 and day 7 after 131I-MIBG injection, adrenal glands with pheochromocytomas increased their relative accumulation of the radionuclide significantly more (p less than 0.02) than did adrenal glands without any demonstrable pheochromocytomas. All the pheochromocytomas were viewed by means of CAT scans. Only one MEN IIa patient had bilateral pheochromocytomas, but our findings indicate that there is a tendency to bilateral adrenal medullary hyperfunction in most MEN II gene carriers. As 131I-MIBG and CAT scans can facilitate the early diagnosis of pheochromocytomas, unilateral adrenalectomy can safely be performed in most MEN IIa patients. Bilateral pheochromocytomas develop in a majority of patients with MEN IIb syndromes. Bilateral adrenalectomy should therefore be performed in these patients.

3-Iodobenzylguanidine↗
PubMed1988

Methodology and dosimetry in adrenal medullary imaging with iodine-131 MIBG.

Iodine-131 MIBG scans were performed in 59 patients in order to localize intra- or extra-adrenal pheochromocytomas (pheos), or to visualize hyperplastic adrenal medulla. Images were obtained from the pelvis to the base of the skull on Days 1, 4, and 7 after tracer injection. The 15 patients with histopathologic confirmation of adrenal medullary disease had positive scans. In three of these, the pheos were visible only on images obtained on Day 7. One scan was false negative. After excluding patients with a predisposition to adrenal medullary disease, nine subjects (28%) without verification of pheo displayed adrenal uptake of the radionuclide. Late images produce a low rate of false-negative scans; the background activity diminishes and even small pheos can be detected. In order to increase the quality of late images, 40 MBq [131I]MIBG was used instead of 20 MBq. The dosimetric considerations are discussed.

3-Iodobenzylguanidine↗
PubMed1986

Benign and malignant thyroid nodules after neck irradiation.

A total of 444 persons were examined for the presence of thyroid nodules on average of 43 years after having been treated with x-rays for cervical tuberculous adenitis. Of this total, 101 subjects had undergone surgery for thyroid nodules: 25 for carcinoma (6%) and 76 for benign nodules (17%). Carcinoma occurred with the same frequency in multinodular and uninodular glands. Because of the uneven age distribution in the current series, it could not be decided whether there was a higher susceptibility of the young thyroid to the induction of thyroid carcinoma or benign nodules. The dosage range for the whole series was 0.40 to 50.90 Gy (40-5090 rad). There was a positive correlation between the absorbed radiation dose and the probability of developing benign and malignant thyroid nodules, even after doses of 20 Gy or more. The risk of developing thyroid carcinoma was equal for men and women, while the female-to-male ratio for benign nodules was 2.9:1, indicating that risk factors associated with females are of less importance in irradiated than in nonirradiated populations. The median latency for carcinoma was 40 years, suggesting that the increased risk of thyroid carcinoma after irradiation remains for the rest of the patient's life.

Adenocarcinoma↗
PubMed1985

Hyperparathyroidism subsequent to neck irradiation. Risk factors.

A follow-up examination of 444 persons treated with x-rays for tuberculous cervical adenitis was performed to determine if the risk for hyperparathyroidism (HPT) following radiation exposure can be related to the age at treatment, the dose of x-rays, or the sex of the patient. The overall incidence of HPT was 14%. There was no definite age-dependent difference in susceptibility to the induction of HPT. The doses of radiation among the 63 subjects who developed HPT ranged from 0.6 to 45.7 Gy (60-4570 rad). There was a statistically significant positive correlation between the dose of radiation and the probability of developing HPT. After doses of 14 Gy (1400 rad) or more 29% of the subjects had developed HPT. After neck irradiation women had twice the relative risk of men of developing HPT. This sex ratio was lower than in the series of nonirradiated HPT patients treated at the same institution during the time of the follow-up study.

Adolescent↗
PubMed1985

An assessment of the risk of developing hyperparathyroidism and thyroid disorders subsequent to neck irradiation in middle-aged women.

We investigated the occurrence of thyroid and parathyroid disorders in 100 women (age 66-70 years) irradiated for cervical spondylosis on average 25 years previously and in 100 control women of similar age. Hyperparathyroidism (HPT), proven by operation, was diagnosed in one patient of each group, and three additional cases were diagnosed biochemically among irradiated women. The difference in incidence is not significant. Nor was there any significant difference in incidence of thyroid disorders. No thyroid carcinoma was found in either group. Even if there is a moderate increase of HPT after neck irradiation in middle-aged women the risk is not so great as to warrant organised follow-up.

Aged↗
PubMed1985

Adrenal scintigraphy in Cushing's syndrome caused by bilateral hyperplasia, adenoma or carcinoma.

The results of scintigraphy in 29 patients with Cushing's syndrome were evaluated. It was possible to separate bilateral hyperplasia from unilateral abnormality. In cases of unilateral abnormality correct localization of the tumour was accomplished and it was possible to visualize adrenocortical carcinoma. The many advantages of adrenal scintigraphy are listed and it is concluded that adrenal scintigraphy is the best means of investigation to differentiate between ACTH-dependent and ACTH-independent Cushing's syndrome.

19-Iodocholesterol↗
PubMed1983

An evaluation of the risk of developing hyperparathyroidism after 131I treatment for thyrotoxicosis.

It is well established that external radiation to the neck area can act as an initiating factor in the development of hyperparathyroidism (HPT). In the present work the incidence of HPT was studied in a series of 125 patients treated with 131I for thyrotoxicosis and in untreated controls matched for age and sex. No increased incidence of HPT was found among the radioiodine treated patients. The time from treatment to follow-up was 21 years on the average. The most probable reason for the lack of an effect on the HPT-incidence is that variable and mostly low doses of radiation with low dose rates are absorbed in the parathyroids after 131I-treatment for thyrotoxicosis.

Adolescent↗
PubMed1982

Transvascular retrieval of an accidentally ejected tip occluder and wire.

Accidental ejection of a tip occluder and wire and subsequent damage of the angiographic catheter tip is described as well as retrieval of the wire. A complication of the final removal was intimal tear and thrombus formation close to the puncture site. Successful thrombectomy and vascular repair was performed. No other complication was encountered.

Abdomen↗
PubMed1981

Radiation-induced parathyroid adenomas and thyroid tumors in rats.

Parathyroid morphology was studied in 45 irradiated and 37 control rats. The irradiated rats received a single parathyroid dose of about 6.5 gray. The rats were killed and autopsied 14 months later. The radiation resulted in fibrosis and depression in weight of the parathyroids. In irradiated rats eleven parathyroid adenomas and four thyroid tumors were found. In control rats no tumor occurred in either parathyroid or thyroid glands. All irradiated rats, including those with a parathyroid adenoma, were normocalcemic.

Adenoma↗
PubMedDate not supplied

Somatostatin receptors on neuroendocrine tumors--a way to intraoperative diagnosis and localization.

Intraoperative radionuclide detection using 111In-DTPA-D-Phe1-octreotide was evaluated in five patients with midgut carcinoids and in three patients with recurrent medullary thyroid carcinoma. Three different time intervals (24, 48 and 120 hr) from injection of the radiopharmaceutical to surgery were used. At surgery, suspect tumors were measured by probe in situ and ex vivo after excision. All tissue specimens and blood samples withdrawn during surgery were measured for 111In activity, and tissue/blood activity concentration ratios were calculated. In situ measurements were valuable especially in neck surgery, where the probe was helpful not only in localization of tumors but also in the control of tumor clearance. Ex vivo measurements were helpful in diagnosing tumor tissue. All five patients with midgut carcinoids were somatostatin receptor-positive, while only three out of seven patients with medullary thyroid carcinoma were receptor-positive. The tissue/blood activity concentration ratios and probe measurement ratios were in general higher in patients with midgut carcinoid than in patients with medullary thyroid carcinoma. Of particular interest were the high tissue/blood concentration ratios in all receptor-positive patients at all time intervals studied. This fact suggests a potential role for radiolabelled octreotide in radiotherapy of these tumor types.

Carcinoid Tumor↗
PubMedDate not supplied

The relevance of somatostatin receptors in thyroid neoplasia.

111In-octreotide scintigraphy in patients with persistent medullary thyroid carcinoma (MTC) visualized tumors in about half of the surgically explored sites. Tumor visualization correlated with rapid tumor growth and large tumor volume as judged from calcitonin levels. The 111In concentration ratio between tumor (T) and blood (B) in surgically excised lymph node metastases of MTC showed a large variation, with low values for microscopic and high values for macroscopic metastases in individual patients. Three cases of MTC, Hürthle cell adenoma and papillary thyroid cancer are reported with preoperative scintigraphy, T/B ratios and Northern analyses of the surgical biopsies. Visualization of tumors was possible in the absence of sstr2 (the high affinity receptor for octreotide) with the exception of microscopic tumor growth. T/B values in the patient with Hürthle cell adenoma were similar to those found in the contralateral thyroid lobe with goitre. The relatively high uptake of 111In in benign thyroid conditions probably limits the use of octreotide scintigraphy in the diagnosis of primary tumors. The technique has certain advantages over radioiodine scintigraphy after the surgical treatment of thyroid tumors: no need for withdrawal of thyroxin substitution; a possibility to diagnose metastases of tumors that do not concentrate radioiodine (MTC, Hürthle cell cancer); and complementary information about metastatic sites of non-medullary thyroid cancer (papillary and follicular tumors).

Adenoma, Oxyphilic↗