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  • Author: J Kovač x
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D. J. McComb and K. Kovacs

ABSTRACT

Fifteen sparsely granulated prolactin-producing adenomas and 10 non-tumourous adenohypophyses, removed by surgical hypophysectomy, have been studied using morphometry at the electron microscopic level. Compared to non-tumourous prolactin cells, sparsely granulated adenomatous prolactin cells showed a significant decrease in diameter and volume density of secretory granules and an increased volume density of rough-surfaced endoplasmic reticulum and Golgi apparatus. The volume density of mitochondria remained unchanged. These results indicate that the cells of the adenoma are in a highly active functional state. It appears that the equilibrium between hormone synthesis, storage and release is altered in adenomatous prolactin cells.

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P. Bösze, Zs. Kóvacs, J. Egyed, J. László and G. Szilágyi

Abstract.

Plasma TSH and Prl responses to iv TRH (200 μg) were studied in 21 euthyroid patients with streak gonad syndrome which is characterised by high levels of FSH and LH and low level of oestrogen and in 9 healthy women. The syndrome is associated with a variety of chromosome complements. Basal TSH and Prl responses to TRH were normal in patients with streak gonads irrespective of their chromosomal complements. Peak levels of both the TSH and Prl occurred at 15–30 min following TRH. The data might suggest that in hypergonadotrophic oestrogen deficiency neither the TSH nor the Prl response to TRH are attenuated. It does not seem that the associated chromosome anomalies alter the TSH and Prl responses to TRH in euthyroid affected patients.

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G. Tolis, L. Kovacs, H. Friesen and J. B. Martin

ABSTRACT

Ten patients with active acromegaly were studied. In 9 plasma GH levels failed to suppress after glucose (OGTT), in 8 an increase in serum GH occurred after thyrotrophin releasing hormone (TRH). After L-Dopa, 4 patients showed no change in serum GH, 3 exhibited a decrease and in 3 an increase in serum hGH occurred. With a combined insulin (ITT) and arginine (ATT) test, 2 patients exhibited an increase in hGH, and in 6 no change occurred. Fasting serum GH concentration was less than 11 ng/ml in 5 patients. Basal prolactin (hPRL) levels were normal in all patients including two with galactorrhea. L-Dopa suppressed and TRH stimulated hPRL secretion in all, but the responses which were seen were subnormal. Hydrocortisone infusion in two acromegalics did not affect the prolactin induced increase after TRH but blunted the GH increase after TRH.

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F. A. László, I. Szijj, J. Kocsis and K. Kovács

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RB Kovacs, J Foldes, G Winkler, M Bodo and Z Sapi

OBJECTIVE: Malignant tumors of the thyroid gland exhibit a variety of histopathologies and clinical behavior. Immune markers are gaining more and more importance in diagnostic pathology, especially in the differential diagnostics and in the grading of thyroid gland tumors. DESIGN: The Authors investigated the immunohistochemical reaction of galectin-3 (gal3) in patients with various thyroid gland diseases. They tested the diagnostic value of gal3 in determining the benign or malignant nature of various lesions, especially in lesions of follicular origin, because previous results have indicated nearly 100% specificity and sensitivity in this regard. METHODS: Gal3 immunoperoxidase reaction was carried out on 91 sections of thyroid gland samples fixed in formalin and embedded in paraffin. RESULTS: While gal3 expressed itself strongly and diffusely in papillary carcinomas (19 of 20 cases), in other malignant lesions it showed weaker, focal or variable positivity. Focal positivity was found in four of 19 follicular adenomas, and negativity was found in three of 10 follicular carcinomas. In all cases of inflammation a focal positivity was observed (eight of eight cases). All nodular goiter and normal thyroid tIssue were negative (25 of 25 cases). CONCLUSIONS: Based on our results, the gal3 immunohistochemical reaction seems to be reliable in the diagnosis of papillary carcinomas. However, in the case of solitary thyroid nodules and follicular lesions, although it is still a useful supplementary marker, it is not of absolute value (as stated in previous studies) in determining whether a tumor is benign or malignant.

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Marie Simard, Carol J. Mirell, A. Eugene Pekary, Jerry Drexler, Kalman Kovacs and Jerome M. Hershman

Abstract. Pituitary thyrotrope tumours are a rare cause of hyperthyroidism. Prior in vitro studies of these tumours have revealed various patterns of differentiation and secretory activity. We have characterized the histological, biochemical, molecular and physiological features of a thyrotrope adenoma in order to define its origin and autonomy. Histochemical and electron micrograph findings confirmed the diagnosis of a thyrotrope cell adenoma. Immunostaining was positive for TSH and GH in the cytoplasm of the adenoma cells. Tissue extracts contained TSH-IR which co-eluted with authentic hTSH when analysed by gel filtration. Tumour fragments studied in a tissue culture system secreted TSH, α-subunit and GH. TRH (30 nmol/l) stimulated TSH and GH secretion. T3 (1.5 nmol/l) inhibited GH release and had no effect on TSH secretion. GnRH (50 nmol/l), dexamethasone (10−4 mol/l), SRIH (1 μmol/l) and TRH-glycine, a tetrapeptide precursor of TRH, stimulated TSH release. Dexamethasone inhibited GH and α-subunit secretion. Stable transcripts for α- and β-subunits of TSH and GH messenger RNAs were detected by molecular hybridization in cytosolic fractions. Immunohistochemistry, in vitro secretory function, and mRNA analysis suggest multidirectional differentiation of the tumour cells. TRH-glycine may have a direct stimulatory effect upon pituitary thyrotropes.

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W M Drake, D M Berney, K Kovacs and J P Monson

We report our findings on markers of cell proliferation (Ki-67 labelling index and topoisomerase-α expression) in a somatotroph pituitary tumour before and after exposure to pegvisomant, a GH receptor antagonist developed for the treatment of acromegaly. Specimens from two separate pituitary operations, separated by a period of 17 years that included 4 years of pegvisomant treatment, were stained for markers of cellular proliferation. Ki-67 labelling index and topoisomerase-α expression were both markedly greater (1–3% compared with 0–0.5% and 15–80% compared with 2–10% respectively) in the pegvisomant-exposed tumour compared with the earlier specimen. Clearly, caution must be exercised when interpreting findings from a single case, particularly one sufficiently refractory to conventional therapies to require treatment with pegvisomant. However, our data reinforce the requirement for careful radiological surveillance of the pituitary in the context of a drug that does not target the tumour responsible and where serum GH cannot serve as a marker of disease activity or tumour size.

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J. R. M. Franckson, W. Gepts, P. A. Bastenie, V. Conard, N. Cordier and L. Kovacs

A la suite des travaux de Long & Lukens (1934) et de Long et al. (1940), ayant montré l'importance des cortico-surrénales dans le métabolisme glucidique, divers auteurs ont pu réaliser un diabète chez le rat et chez le lapin par administration de cortisone ou hydrocortisone (Ingle, 1941, Ingle et al., 1946, Lazarow & Berman, 1950, et Kobernick & More, 1950).

Dans ces recherches, l'action diabétogène des stéroïdes n'apparaissait clairement que dans des circonstances particulières: alimentation forcée, riche en hydrates de carbone (Ingle, 1941, et Lazarow, 1952); pancréatectomie partielle préalable (Ingle et al., 1946); états prédiabétiques réalisés par de faibles doses d'alloxane (Zucker, 1949); action combinée de l'acide déhydroascorbique ou de glutathion (Lazarow, 1952); utilisation de doses très élevées de cortisone. Le diabète réalisé est avant tout transitoire. Lazarow (1952) en donnant 10 mgrs. de cortisone à des rats de 200 grs. obtient un diabète qui atteint le maximum entre le

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V J Moyes, G Alusi, H I Sabin, J Evanson, D M Berney, K Kovacs, J P Monson, P N Plowman and W M Drake

A 64-year-old woman was previously treated for Cushing's disease with trans-sphenoidal surgery, external beam radiotherapy and bilateral adrenalectomy. Progression of an aggressive corticotroph adenoma was evident 3 years post-adrenalectomy; involvement of the clivus was treated with surgery and gamma knife radiosurgery. Tumour spread through the skull base, occiput and left ear with persistent facial pain and left ear discharge; progression continued despite second gamma knife treatment. ACTH levels peaked at 2472 and 2265 pmol/l pre- and post-hydrocortisone respectively. Treatment with temozolomide resulted in a significant improvement in symptoms, a reduction of plasma ACTH to 389 pmol/l and regression of tumour on magnetic resonance imaging scan after four cycles of treatment. We propose that temozolomide is an effective and well-tolerated therapeutic tool for the treatment of Nelson's syndrome and a useful addition to the range of therapies available to treat this condition.

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F. Laczi, J. M. van Ree, A. Wagner, Zs. Valkusz, T. Járdánházy, G. L. Kovács, G. Telegdy, J. Szilárd, F. A. László and D. de Wied

Abstract.

The effects of desglycinamide9-arginine8-vasopressin (DG-AVP) on memory processes have been studied in patients with central diabetes insipidus (DI) and in non-diabetic control patients. Acute im injection of DG-AVP improved some aspects of short-term memory. Subchronic intranasal administration of DG-AVP facilitated short-term memory more consistently and in addition improved long-term memory. DG-AVP increased the attention, but only in the non-diabetic subjects. The effects of DG-AVP on memory processes persisted after discontinuation of treatment. DG-AVP did not affect the parameters for water and electrolyte metabolism, blood pressure and pulse rate neither in DI nor in the control patients. Thus, the memory effects of DG-AVP are probably mediated by a direct action on the central nervous system.