Insulin resistance in fat cells from insulin-treated type I diabetic individuals.

Fat biopsies from the lower abdominal wall were obtained from 13 insulin-treated type I diabetic subjects and from 12 age-, weight-, and sex-matched control subjects. Insulin binding and the antilipolytic effect of insulin were studied. Insulin binding was significantly reduced in the diabetic subjects (34% reduction at tracer binding, P less than 0.05) due to a decreased number of binding sites. In agreement with this, the dose-response curve for the antilipolytic effect of insulin was shifted to the right in the diabetic subjects. Furthermore, the maximal antilipolytic effect of insulin was also reduced (64%, P less than 0.05). Thus, fat cells from conventionally treated type I diabetic individuals are resistant to insulin. This resistance is due to a combination of a decreased number of insulin binding sites and an unspecified intracellular (postreceptor) defect involving the antilipolytic effect of insulin. These findings are in accord with recent in vivo studies showing that type I diabetic patients are also resistant to the stimulating effect of insulin on glucose disposal.

Somatostatin Receptors in the Diagnosis and Therapy of Neuroendocrine Tumor.

The expression of somatostatin receptors in neuroendocrine tumors has facilitated the diagnosis and surgical treatment of patients with these tumors. After injection of a radiolabeled long-acting somatostatin analog, (111)In-octreotide, scintigraphic tumor imaging can ben performed as well as intraoperative tumor localization. During localization studies very high (111)In concentration values were found in tumor tissues versus normal tissues, especially in carcinoid tumors and endocrine pancreatic tumors. Studies on such tumors in cell culture further indicated internalization of (111)In into tumor cells, which is a prerequisite for a radiobiological effect from short range Auger and conversion electrons. Attempts to systemic radionuclide therapy via somatostatin receptors in patients with neuroendocrine tumors have been initiated.

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.

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.

111In-DTPA-D-Phe1-octreotide binding and somatostatin receptor subtypes in thyroid tumors.

UNLABELLED: The purpose of this study was to evaluate the potential for therapy of thyroid tumors using the radiolabeled somatostatin (SS) analog octreotide. METHODS: Concentrations of 111In activity in human thyroid tumors and normal thyroid tissue and blood samples were determined 1-15 d after intravenous injection of 111In-diethylenetriaminepentaacetic acid-Phe1-octreotide. The results were compared with SS receptor (sstr subtype profile (by Northern blot analysis) and the relative expression of the second subtype, sstr2 (by ribonuclease protection assay, RPA). The true tumor volumes in lymph node metastases from 1 patient were estimated. In total, tissues from 68 patients were included in the study. RESULTS: The highest tumor-to-blood ratio (T/B) for medullary thyroid carcinoma (MTC) was 360; for follicular adenoma (FA), 190; for Hurthle cell adenoma (HCA), 140; and for Hurthle cell carcinoma (HCC) and papillary carcinoma (PC), 70. The corresponding value was 7-18 for normal thyroid tissue, with higher values for colloid goiter (8-48) and thyroiditis (7-120). A high T/B was related to a large fraction of tumor cells in lymph node metastases. T/Bs were higher for the tumor samples with expression of sstr2 at Northern blot analysis than for those without. All thyroid tumor types regularly expressed sstr1, sstr3, sstr4, and sstr5. sstr2 was expressed in most MTC tumors but was not detected in FA or PC and was irregularly expressed in HCA and HCC. However, RPA analysis detected sstr2 in all tumors studied. CONCLUSION: Despite the lack of sstr2 at Northern blot analysis in most of the thyroid tumors studied, high T/Bs were in general found when compared with corresponding values for normal thyroid tissue. The sometimes extremely high ratios are promising and indicate a possibility of using radiolabeled octreotide for radiation therapy of sstr-positive tumors in the future.

Systemic radionuclide therapy using indium-111-DTPA-D-Phe1-octreotide in midgut carcinoid syndrome.

A 55-yr-old woman with a midgut carcinoid syndrome due to metastatic spread of an ileal tumor to the liver, paraortic and mediastinal lymph nodes and to the skeleton was given systemic radionuclide therapy with 111In-DTPA-D-Phe1-octreotide. Before therapy, dosimetric calculations were performed on whole-body scintigraphs and 111In retention was shown to be long-lasting. Excretion was mainly seen during the first 24 hr after injection; thereafter whole-body retention remained stationary at 30%. Indium-111 activity in tumor biopsies and blood was measured using a gamma counter. Very high tumor-to-blood ratios were obtained: 150 for the primary tumor and 400-650 for liver metastases, which further justified radiation therapy. Indium-111-DTPA-D-Phe1-octreotide treatment was given on three separate occasions (3.0, 3.5 and 3.1 GBq) 8 and 4 wk apart. After each therapy, the patient experienced facial flush and pain over the skeletal lesions followed by symptomatic relief, even though no objective tumor regression was found radiologically after 5 mo. After initiation of octreotide treatment, there was a 14% reduction of the main tumor marker, urinary 5-HIAA. After three subsequent radionuclide therapies, there was a further 31% reduction of 5-HIAA levels. No adverse reactions, other than a slight decrease in leukocyte counts, were seen. The mean absorbed radiation dose after the three treatments was estimated to be about 10-12 Gy in liver metastases and 3-6 Gy in other tumors, depending on the size and location of the metastases. Assuming internalization of 111In into tumor cells and a radiobiological effect from short range Auger and conversion electrons, there might be a therapeutic effect on the tumor.

Primary culture of human thyrocytes in Transwell bicameral chamber: thyrotropin promotes polarization and epithelial barrier function.

Epithelial properties of thyrocytes are difficult to maintain in conventional cell culture systems. We used bicameral chambers (Transwell) in attempts to establish a functional epithelium of thyrocytes of human origin. Thyroid follicle segments were isolated by collagenase digestion of paradenomatous tissue obtained at surgery for follicular adenoma and of tissue from glands with Graves' disease. After careful separation from connective tissue and single cells by centrifugation, the follicles were plated at high density on the collagen-coated filter of the chambers and cultured in Eagle's essential medium (EMEM) containing 10% fetal calf serum (FCS) or Coon's modified Hams medium enriched with five or six factors (5H, 6H); the latter media contained 5% FCS without (5H) or with (6H) thyrotropin (TSH). The follicles were converted into a confluent cell layer, which had similar DNA content irrespective of type of medium, after 4-6 days. Cells grown in EMEM or 5H established a transepithelial electrical resistance (R) of 200-500 omega.cm2 and was impermeable to [3H]inulin, indicating the formation of epithelial junctions. Addition of 6H to confluent cells initially cultured in EMEM or 5H caused a further increase of R, maximally to 1500 omega.cm2, along with a rise of the transepithelial potential difference; 6H promoted the monolayer formation of cells, increased the number of apical microvilli and reinforced the junctional distribution of actin, cadherin and ZO-1; 6H also enhanced the polarized secretion of [3H]leucine-labeled thyroglobulin into the apical medium. Cells from Graves' thyroid tissue established an epithelium on the filter with similar characteristics to that of normal thyrocytes; some platings contained in addition large numbers of HLA-DR positive cells with a dendritic shape. HLA-DR expression was generally absent in EMEM-or 5H-grown thyrocytes, but appeared in limited areas of the cell layer after 6H and was expressed by all epithelial cells after interferon-gamma stimulation for 48 h. We conclude that human thyrocytes form a tight and polarized epithelium when cultured on permeable filters. The polarized structure and function of the cells are positively regulated by TSH. The culture system may be useful in studies addressing the role of the epithelial phenotype (cell polarity and tight barrier) in normal thyroid function as well as in pathological processes in the thyroid, such as autoimmunity, cell transformation and tumor progression.

Autotransplantation of diseased parathyroid glands into subcutaneous abdominal adipose tissue.

From October 1981 to the end of 1984, 13 patients with primary hyperparathyroidism (PHPT) and 17 with secondary hyperparathyroidism (SHPT) received fresh autografts of diseased parathyroid tissue into their subcutaneous abdominal adipose tissue. Because of previous surgery to treat hyperparathyroidism (HPT) (23%), concomitant thyroid surgery (26%), and a high proportion of multiglandular disease (73%), the patients were at high risk for HPT. During the follow-up period, hypercalcemia was diagnosed in five patients and successfully treated in four: by graft excision in two patients, by excision of a fourth gland from the neck in one patient, and with prednisolone in a patient with sarcoidosis. At follow-up (an average of 30 months after grafting), one patient had HPT and 29 others were euparathyroid. Parathyroid tissue can survive and function in adipose tissue, as was demonstrated by normocalcemia in 14 patients (whose only probable remaining parathyroid tissue had been transplanted into fat), by the demonstration that graft-dependent hypercalcemia could be eliminated by excision of the transplant, and by the demonstration of viable parathyroid tissue by microscopic examination of excised grafts. Autotransplantation of diseased parathyroid tissue into fat is simple and reliable. In cases of recurrent HPT, all or a portion of the graft can be removed while the patient is under local anaesthesia. If infiltrating growth occurs, broad excisions can be performed without sacrificing vital structures.

Associated hyperparathyroidism and nonmedullary thyroid carcinoma: the etiologic role of radiation.

During an 8-year period ending 1981, 372 patients were treated surgically for hyperparathyroidism (HPT) only, 93 for nonmedullary thyroid carcinoma only, and 19 for combined disease (patients traced by follow-up excluded). Seventy-three of these 484 patients (15.1%) had a history of irradiation to the neck region. When calculated for both the HPT and thyroid carcinoma patients there was a significantly increased incidence of associated HPT and thyroid carcinoma among irradiated individuals (P less than 0.001). In irradiated patients with combined disease the increase in serum calcium level was of the same magnitude as in the patient with HPT only, and the distribution according to stage of carcinomas was similar to that in the nonirradiated patients with thyroid carcinoma only. The present findings are in accordance with the hypothesis that radiation can serve as an etiologic factor in the development of associated thyroid carcinoma and HPT.

Parathyroid adenoma weight and the risk of death after treatment for primary hyperparathyroidism.

BACKGROUND: Patients operated on for primary hyperparathyroidism run an increased risk of death, as was found in a previous long-term follow-up of 896 patients. METHODS: In the present study the adenoma weight was determined in 713 patients with single parathyroid gland disease operated on between 1956 and 1982 and followed up in 1986. The adenoma weight was investigated for its usefulness as a prognostic factor. RESULTS: The analysis showed that the adenoma weight was significantly related to the risk of death (p < 0.001). Also a relationship was noted between glandular weight and preoperative serum calcium level (p < 0.001), although the serum calcium level had no predictive value in relation to the risk of death beyond that of the adenoma weight. The risk increase was also estimated as a function of adenoma weight. A moderate adenoma weight increase in a patient with primary hyperparathyroidism was found to imply an increased risk of death, corresponding to the increased risk of smokers as compared with nonsmokers. CONCLUSIONS: The results of this study support surgical treatment at an early stage of primary hyperparathyroidism.

Reoperation in the treatment of asymptomatic metastasizing medullary thyroid carcinoma.

Eleven patients who continued to have elevated calcitonin (CT) levels after thyroidectomy and central node dissection for medullary carcinoma of the thyroid gland (MCT) were subjected to additional surgery. Metastatic MCT was found in the excised tissue from each patient. Normalization of CT values was obtained in four patients who had a few microscopic, unilateral metastases. In these patients an average of 13 normal lymph nodes were excised at reoperation for each metastasis. The results of the reoperative series demonstrate that it is possible, with meticulous neck dissection, to normalize CT levels in patients with microscopic metastases from MCT. Metastases that can be seen or palpated are always associated with microscopic lymph node metastases. Removal of such microscopic metastases is probably the key to achieving normal postoperative CT levels.

Progression of postoperative residual medullary thyroid carcinoma as monitored by plasma calcitonin levels.

BACKGROUND: Patients operated on for medullary thyroid carcinoma (MTC) frequently have persistent elevated plasma calcitonin concentrations after operation, indicating remaining tumor. The plasma calcitonin concentration in a patient with MTC roughly reflects the endogenous tumor burden. The only effective treatment for MTC is surgical. The decision about whether a patient with persistent MTC should have a repeat operation would be influenced by knowledge of the natural course of the disease. METHODS: Forty patients with persistently elevated peak plasma calcitonin concentrations after thyroidectomy for MTC were monitored for a mean of 6 years. Serial determinations of plasma calcitonin levels were obtained before and after intravenous injection of calcium and pentagastrin. RESULTS: At the first postoperative test 63% of the patients had undetectable basal calcitonin values, although their stimulated plasma calcitonin concentrations were elevated. The mean annual increase in stimulated plasma calcitonin concentrations was 117%, but plasma calcitonin concentrations were stable in three patients and decreased in one patient. Five patients are known to have experienced distant metastases. CONCLUSIONS: MTC is a progressive disease in most patients with persistent hypercalcitoninemia after thyroidectomy. Stimulated peak plasma calcitonin levels are more meaningful than basal levels in the serial postoperative evaluation of patients with persistent hypercalcitoninemia after thyroidectomy for MTC.

Disodium pamidronate in the preoperative treatment of hypercalcemia in patients with primary hyperparathyroidism.

Nine patients (median age, 81 years) with primary hyperparathyroidism were treated with intravenous infusions of disodium pamidronate (APD), which is a bisphosphonate drug. Six patients had severe hypercalcemia (serum calcium concentration, greater than 3 mmol/L) persisting after rehydration with saline and treatment with furosemide; three patients had moderate hypercalcemia with pronounced symptoms (serum calcium concentration 2.8 to 2.9 mmol/L). Three of the patients were considered to have hypercalcemic crises. In all patients, the raised serum calcium levels were lowered by the disodium pamidronate infusions. One week after a single infusion of 15 to 60 mg disodium pamidronate, six of the nine patients had serum calcium concentrations within the normal reference interval and two patients had slightly raised values. Transient asymptomatic hypocalcemia was noted in one patient. All patients tolerated the infusions well, and no side effects were noted. In the patients with verified parathyroid adenomas, a temporary increase in parathyroid hormone levels were observed concomitant with the drop in serum calcium level. The patient with parathyroid cancer displayed no such effect indicating an autonomous parathyroid hormone secretion from the parathyroid carcinoma tumor. The good effect of treatment with the osteoclast inhibitor disodium pamidronate on hypercalcemia caused by primary hyperparathyroidism suggests that this hypercalcemia is mainly due to an increased osteoclast activity. The number of patients in this series is yet too small to allow general conclusions. But the case histories in this series show that disodium pamidronate promises to be of value in different clinical situations for the treatment of severe hypercalcemia in patients with hyperparathyroidism. It can be used (1) preoperatively to investigate whether the patient's symptoms are related to the hypercalcemia, (2) in the treatment of hypercalcemic crises when "forced diuresis" has failed to normalize the serum calcium, (3) after unsuccessful parathyroid surgery when it can be used as a long-term treatment before reoperation, giving time for localization studies and healing of the scar reaction, and (4) in aged and fragile patients where it can be tried as an alternative to surgery.

Reoperation for recurrent or persistent medullary thyroid cancer.

BACKGROUND: Initial operations for medullary thyroid cancer (MTC) frequently do not eradicate all disease, as evidenced by persistently elevated levels of stimulated plasma calcitonin. METHODS: Thirty-two patients with MTC and elevated stimulated plasma calcitonin levels after thyroidectomy were studied between 1990 and 1993. Thirty-five repeat neck explorations and microdissections were performed. Four patients also underwent a median sternotomy and mediastinal dissection. RESULTS: In nine patients (group 1), stimulated plasma calcitonin levels were undetectable after reoperation, whereas in 13 cases (group 2) the calcitonin levels decreased by 40% or more. In 10 cases (group 3) the CT levels did not decrease. Primary tumors that exhibited invasive features (invasion of adjacent structures or extranodal or extracapsular spread) were found more often in patients from group 3 than in patients from groups 1 or 2 (p < 0.05, Fisher's exact test). CONCLUSIONS: Reoperation resulted in normalization of calcitonin levels in 28% of patients and a decrease in calcitonin levels by 40% or more in another 42% of patients. The data also suggest that patients whose primary MTC has invaded tissues beyond the thyroid gland or a lymph node capsule are less likely to benefit from repeat operation.

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.

Growth of human pheochromocytomas in the anterior eye chamber of the rat. A histochemical study on amine and peptide content of pheochromocytoma tumour cells.

Tissue pieces from seven benign human pheochromocytomas have been successfully transplanted to the anterior eye chamber of cyclosporin-treated rats. In vivo observations showed that 74-99% of the tumour transplants were vascularized within one to two days after transplantation. No increase in the size of the transplants was noted during the observation period (1-4 weeks). Tumour transplants grown in non-immunosuppressed rats were initially vascularized but rejection started to occur one week after transplantation. Histochemical analysis of tumour transplants grown in immunosuppressed rats demonstrated numerous tumour cells with strong catecholamine fluorescence, some of which formed long cell processes on the host iris. Immunocytochemical analysis of tumour transplants demonstrated positively labelled tumour cells after incubation with antisera against neuropeptide Y, enkephalin, vasoactive intestinal polypeptide, somatostatin, substance P, dopamine-beta-hydroxylase, tyrosine hydroxylase and serotonin. A similar histochemical and immunocytochemical pattern was observed in primary tumours but tumour cells sending out cell processes were observed less frequently. Human pheochromocytomas may thus be successfully grown in oculo in cyclosporin-treated rats. This may prove to be a suitable model for the study of storage and release of catecholamines and neuropeptides from pheochromocytoma tumour cells.

Autotransplantation of fresh diseased parathyroid tissue in primary and radiation-induced hyperparathyroidism.

Thirty-five patients with primary or radiation-induced hyperparathyroidism underwent autotransplantation with fresh diseased parathyroid tissue. Due to previous neck surgery (34 percent), concomitant thyroid surgery (66 percent), and a high proportion of multiglandular parathyroid disease (43 percent), all patients ran a high risk of becoming hypoparathyroid, At follow-up , a mean of 28 months after operation, 32 patients had normal parathyroid function, 2 had hyper- and 1 had hypoparathyroid function. The amount of tissue used for transplantation was individually chosen by relating the serum calcium level to the total parathyroid mass. In patients with water-clear cell hyperplasia and thus low endocrine activity on a weight basis, large grafts were needed, whereas less than 120 mg was used in most other cases. In two of our three failures we did not follow these tactics. Our results show that autografting fresh diseased parathyroid tissue can minimize the occurrence of postoperative hypoparathyroidism in patients at high risk of this complication. In no case has recurrent or progressive hypercalcemia developed.

Latent hypoparathyroidism in patients with autotransplanted parathyroid glands.

Eighteen patients had undergone radical surgery for thyroid carcinoma. In all of them four parathyroid glands had been verified by frozen-section biopsy and removed. Thereafter two, three or four glands wereautotransplanted into muscle tissue. At least 1 year after the operation the patients underwent a calcium deprivation test. Before the test they all had normal serum calcium values without treatment. During the test seven patients remained normocalcemic, seven became hypocalcemic, and four had occasional low serum calcium values. After the test all were normocalcemic again. Patients with only autotransplanted parathyroid glands left after surgery should be tested for latent hypoparathyroidism.

Incidence of hypoparathyroidism after radical surgery for thyroid carcinoma and autotransplantation of parathyroid glands.

Ninety-seven consecutive patients had radical surgery for thyroid carcinoma. Eighty-six of these had one or more parathyroids implanted into muscle tissue. At follow-up, ninety-one patients were normocalcemic without substitution, fifteen of those with only implanted glands. The results show that radical surgery can be performed with a low incidence of hypoparathyroidism, provided the parathyroids are carefully searched for and liberally implanted.

Recent results of reoperative surgery in medullary carcinoma of the thyroid.

Reoperative surgery of medullary carcinoma of the thyroid can be avoided by meticulous primary surgery. Reoperative surgery can succeed even if the tumour and its metastases are bilateral, as is often the case in hereditary cases. Even patients with numerous macroscopic metastases can show normaligation of their calcitonin (CT) levels in response to reoperative surgery. Patients with normal postoperative CT values after the combined short time Ca++ and pentagastrin test continued to show normal results when followed up for up to eight years.