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Cyclic 3',5'-nucleotide phosphodiesterase activities in the thyroid glands of patients with various disorders.

Thyroid tissue was found to contain at least least two separable cyclic 3',5'-nucleotide phosphodiesterase (cAMP-PDE and cGMP-PDE) activities, as determined by DEAE-cellulose or Sepharose 6B column chromatography. These activities were cAMP- and cGMP-hydrolyzing enzymes. Quantitative differences of cAMP or cGMP hydrolytic activity were observed in tissues from patients with thyroid disorders. Theophylline, modulator protein, and Mg2+ produced similar effects on cAMP or cGMP hydrolytic activity in tissues from patients with a without various thyroid disorders. The mode of the inhibitory effect of cyclic nucleotides on PDE activities in thyroid tissues was competitive, in contrast to the mode seen in other organs. Both cAMP and cGMP hydrolytic activities were elevated in the tissues from patients with hyperthyroidism and thyroid carcinoma compared with the activity in controls. cGMP hydrolysis in hyperthyroidism was 4.4-fold higher than that seen in the controls. The ratio cGMP to cAMP hydrolysis was highest in cases of hyperthyroidism and lowest in cases of thyroid carcinoma, when PDE activities were determined with a substrate concentration of 0.4 microM. Kinetic analysis revealed that higher PDE activity in tissues from patients with hyperthyroidism and thyroid carcinoma was due to an increase in maximal velocity. The apparent Km values for hydrolysis of cyclic nucleotides were similar in normal and pathological thyroid tissues.

3',5'-Cyclic-AMP Phosphodiesterases↗

Neuroendocrine tumors of the thyroid gland.

The neuroendocrine lesions of the thyroid are few in number and include C-cell lesions (C-cell hyperplasia and medullary carcinoma), mixed C-cell and follicular-derived tumors, paraganglioma, intrathyroidal parathyroid adenoma, and metastasis to the thyroid from neuroendocrine carcinoma arising elsewhere. However, some follicular-derived lesions of the thyroid can show trabecular and nesting growth patterns characteristic of neuroendocrine tumors. These lesions should also be included in the differential diagnosis of primary and secondary neuroendocrine tumors of the thyroid.

Adenoma↗

Oxalate in the human thyroid gland.

Ninety-seven fixed surgical thyroid specimens and 63 unfixed and 40 fixed thyroid specimens from autopsies were examined for their oxalate content. Proteases were used to process the tissue, and the oxalate was determined with an enzymatic assay. The fixed samples were grouped into seven diagnostic categories (diffuse colloid goitre; partially diffuse, partially nodular colloid goitre; nodular colloid goitre; goitre with multifocal functional autonomy; non-functioning adenoma; unifocal functional autonomy; Graves' disease). The oxalate concentrations of the samples were mainly dependent on age and gender, which were distributed unequally among the seven diagnostic groups. In thyroid tissue from cases of Graves' disease, however, the concentration of oxalate was remarkably low and statistically different from those of four of the six other groups.

Adenoma↗

[Classification of thyroid gland operations].

Classification of operations on thyroid gland depending on the tissue volume preserved and basing on the analysis of surgical treatment of more than 2000 patients was presented. Substantiation and characteristics of its headings permits to take into account the intervention volume, what is peculiarly important during the automatized processing of large masses of information.

Data Collection↗

[Surgical therapy of benign thyroid gland diseases].

Operations due to benign thyroid diseases are one of the most common elective surgical procedures performed in Germany. In the majority of cases, the preoperative determination of the serum thyrotropin concentration and an ultrasound of the thyroid region are sufficient preoperative investigations. In cases of thyroid functional disorders a scintigram should be additionally performed. Indications for operation in nodular goiter are local, mechanical compression, suspicion of malignancy and focal or disseminated autonomy. In Graves' disease the indication for operation is usually recurrent hyperthyroidism after medical treatment. In endemic nodular goiter the morphology of the nodular thyroid tissue is the guideline for resection; i.e. all nodules have to be removed. In Graves' disease the function of the remaining thyroid tissue is essential. The standardized subtotal resection with remaining tissue around the hilus, which frequently barries nodules, should be avoided. Instead a selective resection which takes the individual morphology and function of the diseased thyroid tissue into account should be favorized. With this operative technique the surgeon will have frequently direct contact with the recurrent nerve and the parathyroids. It is documented, that intraoperative visualisation of the recurrent nerve decreases not only the rate of permanent nerve damages but increases as well the completeness of resection. Additionally, ligation of the inferior thyroid artery decreases the incidence of residual or recurrent disease without enlarging the risk of postoperative parathyroiprive hypocalcemia. An individual follow-up with iodine and/or thyroxine replacement therapy is an indispensable component of the surgical therapeutic approach. The target of thyroxine substitution in patients after resection due to benign thyroid diseases is a physiologic serum thyrotropin concentration (0.3 to 4.0 mU/l).

Arteries↗

[Diagnosis and surgical therapy of thyroid gland diseases in childhood].

Among children, thyroid disease rarely points to a particular surgical therapy and therefore requires a very specific surgical approach as well as close interdisciplinary cooperation between pediatricians, pediatric surgeons, and nuclear medicine practitioners, in particular regarding the follow-up. As a consequence, excellent functional and long-terms results can be achieved. The extent of the radical surgery pertaining to the small, encapsulated papillary carcinoma is still being discussed and investigated.

Adolescent↗

Immunocytochemical studies of the peptidergic innervation of the thyroid gland in the Brattleboro rat.

An indirect immunofluorescence technique was used to study the peptidergic innervation of the thyroid gland in homozygous Brattleboro rats (DI) and normal Long-Evans rats (LE). The primary goal of this study was to determine whether the previously demonstrated decrease in thyroid responsiveness to TSH in DI might be due to an abnormality in the innervation of the thyroid. Thyroids from both types of rats were found to contain nerve fibers containing immunoreactivity for vasoactive intestinal peptide (VIP), substance P (SP), neuropeptide Y (NPY), and peptide HI (PHI). All four types of fibers were found in close association with both follicle cells and blood vessels. Well developed networks of fibers surrounding blood vessels were particularly apparent in the case of NPY. The density of fibers associated with follicle cells in DI was at least as great as that in LE in regard to SP, NPY, and PHI. Fibers containing VIP were found in greater abundance in DI than in LE. Additional studies revealed no evidence of thyroid fibers containing either somatostatin or neurophysin, which was used as a marker for vasopressin. We conclude that the reduced responsiveness of the thyroid in DI is not due to an inadequate supply of any of the neuropeptides included in this study. Since VIP is known to enhance thyroid secretion, we suggest that the apparent proliferation of VIP-containing fibers in DI may be a reflection of a neural mechanism attempting to compensate for a thyroid gland deficiency analogous to the humoral mechanism by which TSH secretion increases in response to thyroid deficiency.

Animals↗

[Morphofunctional characteristics of rat thyroid gland under the combined effect of oxytocin and adrenaline].

The influence of oxytocin, adrenalin and their combination on rat thyroid gland was studied after intraperitoneal administration of these hormones and following incubation of thyroid gland fragments in media, containing the neurohormones. Thyrostimulating effect of oxytocin (increase in thyrocyte height and 3H-leucine incorporation) was demonstrated in in vivo and in vitro experiments. Adrenaline did not cause morphofunctional changes in thyrocytes although it suppresses oxytocin thyrostimulating effect when administered simultaneously with it in both in vivo and in vitro experiments.

Animals↗

The thyroid gland with low uptake lesions: evaluation by ultrasound.

An ultrasound examination was performed in 401 patients who had isotopically cold, solitary lesions of the thyroid gland. Of the parameters studied, the level of echoes was the most useful in making the sonographic diagnosis: the rate of malignancy was extremely low both in hyperechoic and echo-free lesions. The presence of a peripheral, complete "halo" appeared to be helpful in differentiating benign lesions from malignant lesions. Approximately 20-25% of the lesions thought to be solitary on the radionuclide study were found to be multinodular on US. When fine-needle aspiration biopsy was used with US the need for surgical exploration of the thyroid gland was obviated in selected cases.

Adenocarcinoma↗

Presence of calcium oxalate crystals in the mammalian thyroid gland.

Birefringent crystals of calcium oxalate have been previously identified in the colloid of human thyroid glands. We found such crystals in 19/20 adult thyroids at autopsy, in 4/20 infants at autopsy, and, using frozen sections, in 19/20 thyroids partially or totally removed at surgery. These crystals were soluble in hydrochloric acid, insoluble in acetic acid, and contained only calcium by energy dispersive X-ray microanalysis, confirming their calcium oxalate character. Similar crystals were found in equine and ovine thyroids.

Birefringence↗

Papillary clear cell carcinoma of the thyroid gland.

A case of an unusual papillary clear cell carcinoma of the thyroid gland is described. The patient expired 17 days after operative biopsy and thyroxine suppression. Special stains were helpful in differentiating renal cortical carcinoma and parathyroid malignant disease from primary papillary clear cell carcinoma of the thyroid. Ultrastructural features of this tumor may relate to the effects of thyroid stimulating hormone as well as the malignant nature of the tumor.

Adenocarcinoma↗

[Palpation and sonographic evaluation of the size of the thyroid gland].

The author compared in 88 13-year-old children evaluation of the size of the thyroid gland by palpation and sonography. Evaluation by the two methods was in agreement in 64 cases (73%) and controversial in 24 cases (27%). Palpation led in 24 instances to overestimation of the size and in 7 children (8%) to underestimation, as compared with sonography. Sonography is an essential method for evaluation of the thyroid gland in children.

Adolescent↗

Age associated increase of C cell follicles in guinea pig thyroid glands.

The effect of aging on the formation of C cell follicles was examined in the thyroid gland of guinea pigs at various ages ranging from 1 to 29 months. The C cell follicles were demonstrated with the immunoperoxidase methods by using anticalcitonin and antisomatostatin antisera and with PAS reaction. They were already detected in 1-month-old guinea pigs but in low number. Thyroid glands from 1- to 14-month-old animals contained only a small number of C cell follicles and did not reveal the age-related increase. In aged guinea pigs (20- to 29-month-old), a dramatic increase of C cell follicles was found, about 13 times as high as the number of other age groups. The C cell follicles through all age groups were present in large clusters of C cells. In the aged guinea pigs, nodular large aggregates of C cells regarded as C cell hyperplasia occurred and numerous C cell follicles were formed in the large cell aggregates. Thus, the conspicuous increase of C cell follicles in aged animals was associated with a proliferative abnormality of C cells. The C cells forming follicles showed moderate to weak immunoreactivity for calcitonin, whereas they showed very intense immunoreactivity for somatostatin. In addition, the colloidlike and flocculent materials stored in the follicular lumina, which were consistently PAS-positive, were weakly immunoreactive to somatostatin but nonreactive to calcitonin.

Aging↗

Functional connections between the suprachiasmatic nucleus and the thyroid gland as revealed by lesioning and viral tracing techniques in the rat.

Frequent blood sampling via intraatrial cannula revealed daily rhythms of TSH and thyroid hormones in both male and female Wistar rats. Thermic ablation of the biological clock, i.e. the suprachiasmatic nucleus (SCN), eliminated the diurnal peak in circulating TSH and thyroid hormones. In addition, SCN lesions produced a clear decrease of 24-h mean T4 concentrations. A more pronounced effect of SCN-lesions on thyroid hormones, as opposed to TSH, suggested routes of SCN control additional to the neuroendocrine hypothalamopituitary-thyroid axis. Retrograde, transneuronal virus tracing was used to identify the type and localization of neurons in the central nervous system that control the autonomic innervation of the thyroid gland. In the spinal cord and brain stem, both the sympathetic and parasympathetic motorneurons were labeled. By varying the postinoculation survival time, it was possible to follow the viral infection as it proceeded. Subsequently, the pseudorabies virus (PRV) infected neurons in several brain stem cell groups, the paraventricular nucleus of the hypothalamus (PVN) and the central nucleus of the amygdala (second order labeling). Among PRV-infected neurons in the PVN were TRH-containing cells. Third order neurons were found in several hypothalamic cell groups, among which was the SCN. Therefore, we propose that the SCN has a dual control mechanism for thyroid activity by affecting neuroendocrine control of TSH release on the one hand and the autonomic input to the thyroid gland on the other.

Amygdala↗

Immunocytochemical localization of prohormone convertases PC1 and PC2 in the mouse thyroid gland and respiratory tract.

We examined immunocytochemical localization of the prohormone convertases, PC1 and PC2, in the thyroid gland and respiratory tract of the adult mouse using the indirect enzyme- and immunogold-labeled antibody methods for light and electron microscopy, respectively. In the thyroid gland, PC1- and/or PC2-immunoreactive cells were cuboidal, scattered in the follicular epithelium and in the interfollicular spaces. When serial sections were immunostained with anti-calcitonin, anti-PC1, anti-calcitonin-gene-related-peptide (CGRP), and anti-PC2 sera, respectively, localization of both PC1 and PC2 was restricted to the calcitonin/CGRP-producing parafollicular cells. In the respiratory tract, only PC1 immunoreactivity was observed in the basal granulated neuroendocrine cells, which were scattered in the tracheal epithelium. Consecutive sections immunostained with anti-PC1 and anti-CGRP sera showed that a subpopulation of these PC1-immunoreactive cells contained CGRP. Double immunogold electron microscopy of the thyroid parafollicular cells revealed that calcitonin- and/or CGRP-immunopositive secretory granules were also labeled with both PC1 and PC2. These findings suggest that procalcitonin is proteolytically cleaved by PC2 alone or by PC2 together with PC1, and that the proCGRP is cleaved by PC1.

Animals↗

[Role of thermovision in the diagnosis of surgical diseases of the thyroid gland].

Thermovision (thermography) was applied to the examination of patients with different thyroid gland pathology. The majority of benign formations of the organ were hypothermic, and hyperthermia was observed in the area of malignant tumour localization. A combined use of scannographic and thermovision methods widened possibilities of preoperative differential diagnosis of benign and malignant pathology of the thyroid gland. Hyperthermia was recorded in the area of the hyperfunctioning tissue localization in patients with diffuse toxic goiter with or without a node. Hyperthermia diminished during the treatment with thyrostatic agents; this could serve as control of the efficacy of the therapy and aid in the choice of the optimal periods for surgical intervention.

Adenoma↗

Parathyroid gland involvement by papillary carcinoma of the thyroid gland.

OBJECTIVE: To describe the phenomenon of parathyroid gland involvement by thyroid carcinoma and to explore its clinicopathologic significance. DESIGN: We reviewed the clinicopathologic features and described the histopathologic characteristics of 20 cases of parathyroid involvement found in a series of 911 papillary thyroid carcinomas. RESULTS: Parathyroid involvement occurred in 3 patterns: (1) direct invasion from the main tumor with an infiltrative growth, (2) invasion of the parathyroid gland with an expansive growth and formation of a pseudocapsule between the carcinoma and the parathyroid gland, and (3) metastatic deposition within the parathyroid gland itself. Among the 20 cases, 6 (30%) had primary tumors measuring 1 cm or less, and 14 (70%) had primary tumors measuring more than 1 cm. The cases with smaller primary tumors had a comparatively lower rate of nodal metastasis (50% vs 100%, P =.02). Furthermore, none of the cases with smaller primary tumors had invasion of extrathyroid structures other than parathyroid gland, but such invasion was common among the cases with larger primary tumors (0% vs 71%, P =.01). CONCLUSION: To the best of our knowledge, this is the first report showing that parathyroid involvement occurs in papillary thyroid carcinomas even in the early stage of the disease.

Adult↗