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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The action of thyrotropin (TSH) on plasma membranes was studied to elucidate the mechanism of hormonal regulation of malignant versus normal human thyroid tissue. Thyroid plasma membranes of six specimens of papillary or follicular carcinoma and six of adenoma, as well as adjacent normal tissue obtained from these patients, were evaluated with respect to binding of 125I-labeled TSH and stimulation of adenylate cyclase. Scatchard analysis of TSH binding revealed the presence of two species of binding sites in normal thyroid of different affinities and capacities. In 11 of 12 tumors studied, the high-affinity binding site remained intact; however, the total number of low-affinity sites was markedly lower than normal tissue. Other parameters of binding were not altered in neoplastic thyroid. In each of these tissues, the hormone responsiveness and kinetics of adenylate cyclase activation were essentially identical to those observed in normal tissue, although basal activity was typically greater in the neoplasm. One carcinoma was totally deficient in both 125I-labeled TSH binding and TSH-stimulatable adenylate cyclase, although basal activity was detected. Furthermore, adenylate cyclase of this specimen was not activated by prostaglandin, in contrast to normal thyroid and other thyroid tumors. These results suggest that: (a) clinical behavior of thyroid carcinomas may not be reflected by TSH receptor-adenylate cyclase function; (b) lack of clinical response as manifest by tumor regression cannot be ascribed to the absence of functional TSH receptors or adenylate cyclase; and (c) decreased low-affinity binding present in tumors is not correlated with altered hormone responsiveness of adenylate cyclase but may reflect more general cancer-induced changes in membrane structure or composition.
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PMID:Thyrotropin receptor-adenylate cyclase function in human thyroid neoplasms. 626 64

The effect of TSH (100mU/ml) and norepinephrine (100 muM) on the cyclic AMP levels was studied in 10 human normal tissues, 10 thyroid adenomas and 4 thyroid carcinomas (3 papillary and 1 follicular). Normal tissues responded to TSH with a marked elevation of the cyclic AMP level. Response patterns of 10 thyroid adenomas to TSH were variable; the patterns of 6 cases resembled those of normal tissues, 3 responded mildly, and one had no response to TSH. Thyroid carcinomas had a higher basal level of cyclic AMP than those of normal tissues, although they responded only slightly to TSH. Two among 4 thyroid carcinomas had no response to TSH. Norepinephrine stimulated the accumulation of cyclic AMP in 4 thyroid adenomas and 3 thyroid carcinomas, while it had little effect on normal tissues. Responses to norepinephrine was observed only in thyroid tumors, although they had low response to TSH. It is suggested from these results that tumor cells originating from thyroid follicular cells have a modified response to hormones due to neoplastic alterations.
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PMID:Effect of thyroid-stimulating hormone and norepinephrine on cyclic AMP levels in human normal thyroids and human thyroid tumors. 626 97

Thyroid-stimulating hormone (TSH) in tumor and serum of mice with thyrotropic tumors was studied by radioimmunoassay (RIA), radioreceptor assay (RRA) and thyroid adenylate cyclase assay (ACA). In unfractionated samples, serum TSH displayed significantly higher ACA/RIA (0.69 +/- 0.10) and ACA/RRA ratios (0.79 +/- 0.04) than TSH in tumor extracts (0.45 +/- 0.05 and 0.31 +/- 0.01, respectively). After gel chromatography, both tumor and serum TSH activity measured in RIA and RRA eluted in broad, heterogeneous peaks with an apparent molecular weight range of 26,000 - 44,000 daltons. The ACA activity of tumor TSH eluted in 2 sharp peaks (26,000 and 44,000) while that of serum TSH eluted in 3 peaks (26,000, 33,000 and 44,000). The ACA/RIA and ACA/RRA ratios varied greatly among the chromatography fractions, the lowest ratios being detected in the tumor TSH of 33,000 daltons (0.02 for each) and the highest ratios in both tumor and serum TSH of 26,000 (ACA/RIA = 1.60 - 1.90, ACA/RRA = 1.12 - 1.20). Since previous biosynthetic studies have suggested that such heterogeneous forms of mouse tumor TSH differ solely in carbohydrate content, our data suggest that the biologic activity of TSH may be modulated by its glycosylation.
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PMID:Heterogeneous forms of thyroid-stimulating hormone in mouse thyrotropic tumor and serum: differences in receptor-binding and adenylate cyclase-stimulating activity. 627 77

Thyroid scintigraphy, using 99mTc(V) dimercaptosuccinic acid, was performed in four patients with pathologically confirmed medullary thyroid carcinoma and elevated serum calcitonin values. Significant uptake of the tracer was found in the clinically palpable cervical tumor masses, metastatic sites, and residual tumor. This finding, probably specific for medullary thyroid carcinoma, could be of great use in the diagnosis and the surgical follow-up.
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PMID:A new imaging agent for medullary carcinoma of the thyroid. 632

The immunogenic properties of one (or few) selected antigen(s) encoded by the mouse major histocompatibility complex was studied using the C57BL/6(B6) mouse strain and its descendant B6.C-H-2bm1(bm1) mutant. These strains differ in a point mutation in the H-2K region. We compared the immunogenic and antigenic expression of the mutated antigen on different bm1 tissues by testing the vulnerability of these tissues to graft rejection response in B6 recipients. Previous results demonstrated that B6 and bm1 mice do not reject reciprocal thyroid transplants, despite the acute rejection of reciprocal skin grafts. Thyroid grafts were rejected, however, after presensitizing the recipients with skin graft syngeneic with the thyroid, but not after sensitization with spleen cells. In the present work we induced tumors in bm1 mice by treating them with a chemical carcinogen (3-methylcholanthrene). We found that two out of four tumors demonstrated strict strain specificity and were rejected by all mouse strains (including the B6 recipients) except by their strain of origin. All tumors were found to be sensitive to in vitro lysis by B6 anti-bm1 effector cells. HZ1-A and HZ1-B tumor cells were rejected by B6 recipient mice but could not immunize B6 mice against a subsequent bm1 thyroid graft. When testing the immunogenicity of B6 originated EL4 leukemia cells (which are fatal to B6 mice), we found that the tumor cells were rejected by bm1 recipients, but, unlike B6 skin grafts, were incapable of inducing the rejection of a subsequent B6 thyroid transplant. The results demonstrated that an H-2K molecule may exhibit different immunological properties when expressed on cells of different tissues. The different expression of the mutated antigen on different cell types, its ability to trigger T cells but not B cells responses and the potential involvement of the tissue specific differentiation molecules in the graft rejection response are discussed.
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PMID:Immunogenicity of the mutated H-2Kbm1 antigen(s). Test of thyroid graft rejection between B6.C-H-2bm1 and C57BL/6 mice following reciprocal immunization with normal versus malignant cells. 636 78

This study investigated the potential of contrast-enhanced CT in the differential diagnosis of the most common anterior upper mediastinal expansions. CT examinations of 29 patients with an upper anterior mediastinal mass lesion of unknown origin were reviewed retrospectively and compared with the clinical data obtained. The density, contrast enhancement and invasive nature of the tumors were recorded. Thyroid tissue was enhanced most and lymphomas least. Contrast medium injection helped to distinguish great vessels and cystic lesions from surrounding areas. Thyroid tissue was most heterogeneous and lymphomas most homogeneous. All except one of the malignant neoplasms (a lymphoid mass lesion) were infiltratory in nature. Contrast-enhanced CT gives clues as to the origin of a neoplasm and whether it is benign or malignant.
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PMID:Differential diagnosis of anterior upper mediastinal expansions by contrast-enhanced computed tomography. 647 11

The natural history and prognostic factors of medullary carcinoma of the thyroid (MCT) were studied in 161 patients seen at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston between 1944 and 1983. One hundred twenty-five patients (77.6%) had the sporadic variety of MCT, 31 patients (19.3%) had multiple endocrine neoplasm (MEN) type IIa and 5 patients (3.1%) had MEN-IIb. The disease occurred equally in both sexes (M:F ratio 1:1.05). Thyroid nodules were the most common presenting feature especially in patients with the sporadic disease and MEN-IIb. Fifteen patients with MEN-IIa had occult MCT; the diagnosis was made through screening of family members with calcitonin measurement before and after stimulation with calcium or pentagastrin. Sixteen patients with MEN-II had pheochromocytoma and 7 had hyperparathyroidism. Total thyroidectomy was the most commonly performed operation. The lowest incidence of recurrence occurred in patients who underwent total thyroidectomy and modified neck dissection. Radioactive 131I was used as adjunct to surgery in 19 patients but it did not improve the survival or lower the incidence of recurrence. Patients who received postoperative radiotherapy had significantly lower adjusted survival rates than those treated by surgery alone, but we tended to irradiate patients with more advanced disease. Chemotherapy was administered to 11 patients with disseminated metastases but the response was poor. The 5- and 10-year adjusted survival rates of all the patients with MCT were 78.2% and 61.4%, respectively. Patients with MEN-IIa had much better rates than patients with sporadic disease (p = 0.0005), who were 7.74 times more likely to die of MCT. The stage of the disease at presentation was a major prognostic factor. Patients with stages III or IV disease were 7.31 times more likely to die of MCT than those with stages I or II. There was no significant difference in survival between patients with stages I and II or III and IV. The presence of cervical lymph node metastases did not affect the survival adversely. Direct extension with involvement of tissue was a bad prognostic sign. Patients younger than 40 years old at the time of diagnosis of MCT had a significantly better adjusted survival rate than those who were older. Women had a better prognosis than men, who were 1.89 times more likely to die of MCT. Diarrhea was a bad prognostic sign. However, it occurred more frequently in patients with advanced stages of the disease and larger tumor mass.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Medullary carcinoma of the thyroid. A study of the clinical features and prognostic factors in 161 patients. 650 83

Parathyroid hormone (PTH) concentrations were compared in blood drawn from the bone marrow and antecubital vein of patients undergoing marrow biopsy for suspected hematological neoplasia. Radioimmunological analysis revealed that the bone marrow blood had a higher PTH content than blood from the peripheral circulation. Thyroid hormone-binding globulin was not distributed asymmetrically, showing that the gradient is PTH specific. The intact PTH content of marrow blood was 65% greater than that in the venous system, whereas carboxyl regional PTH levels showed a 34% gradient in favor of the marrow. Although the majority of patients were found to have hematological malignancies, there was no discernible influence of tumor on the PTH gradients. The physiological implications and possible origins of the asymmetrical PTH distribution are discussed.
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PMID:Parathyroid hormone concentration gradients across the human bone marrow. 661 24

Thyroid function tests, radioiodine uptake and scintiscanning, and antithyroid antibody titers are the main laboratory tests useful in the management of goiter. Scintiscanning and ultrasonography aid in differentiating a functioning adenoma from a "cold" solid nodule--a crucial distinction since the incidence of cancer in a cold nodule is 20 percent. Radioiodine scanning and serum thyroglobulin help in the diagnosis of a well-differentiated thyroid cancer. Serum calcitonin serves as a reliable tumor marker for medullary carcinoma.
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PMID:Laboratory evaluation of anatomic disorders of the thyroid. 663 50

The results of investigation and treatment of 8 patients with initial hypothyrosis, galactorrhea and disturbed menstrual function are presented. The initial hypothyrosis in patients with galactorrhea may have a latent form and/or be combined with intracellular hypophyseal tumor. Sometimes the first sign of the syndrome mentioned is abnormal lactation. The prolactin level is elevated in these patients and its depot increased. In latent hypothyrosis the thyrotropin content is within normal, its response to thyroliberin stimulation being enhanced and prolonged. Thyroid hormone therapy is effective in these patients. It was concluded that thyroid hormone substituting therapy is an adequate method for the treatment of initial hypothyrosis, galactorrhea and disordered menstrual function.
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PMID:[Characteristics of the course of hypothyroidism in the galactorrhea syndrome]. 668 24


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