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This study assessed the morphological criteria for the diagnosis of various types of lymphocytic thyroiditis in fine-needle aspirates. Of 950 aspirates, 121 revealed lymphocytic thyroiditis, including Hashimoto's thyroiditis (partly confirmed by serological or histological examination) and focal thyroiditis adjacent to neoplasms. The diagnosis of Hashimoto's thyroiditis was easy when the aspirated material was adequate and contained oxyphilic cells; in the fibrous type, diagnosis was rather difficult. Focal thyroiditis may be confused with Hashimoto's thyroiditis, especially when adjacent to neoplasm. Surgical exploration should be performed in cases of severe lymphocytic thyroiditis revealed by fine-needle aspiration with repeatedly negative antibody titers in order to exclude neoplasm.

BACKGROUND: Metallothionein (MT) protein expression deficiency has been implicated in carcinogenesis while MT over expression in tumors is indicative of tumor resistance to anti-cancer treatment. The purpose of the study was to examine the expression of MT expression in human renal cell carcinoma (RCC) and to correlate MT positivity, the pattern and extent of MT expression with tumor histologic cell type and nuclear grade, pathologic stage and patients' survival. PATIENTS AND METHODS: The immunohistochemical expression of MT was determined in 43 formalin-fixed and paraffin-embedded RCC specimens, using a mouse monoclonal antibody that reacts with both human MT-I and MT-II. Correlation was sought between immunohistochemical (MT positivity, intensity and extension of staining) and clinico-pathological data (histological cell type, tumor nuclear grade, pathologic stage and patients' survival). RESULTS: Positive MT staining was present in 21 cases (49%), being mild/moderate and intense in 8 and 13 cases, respectively. The pattern was cytoplasmic in 7 cases and was both cytoplasmic and nuclear in 14 cases. MT expression in a percentage of up to 25% of tumor cells (negative MT staining included) was observed in 31 cases, in a percentage 25-50% of tumor cells in 7 cases, and in a percentage of 50-75% of tumor cells in 5 cases. There was no significant correlation of MT intensity of staining to histological type, stage and patients' survival, while it was inversely correlated to higher tumor nuclear grade. MT extent of staining did not correlate with histological type, nuclear grade, and pathologic stage while a statistically significant association was found with patients' survival. CONCLUSIONS: The inverse correlation between MT staining intensity and tumor nuclear grade in RCC suggests a role of MT in tumor differentiation process. Since extent of MT expression is inversely correlated with survival it may be possibly used as a clinical prognostic parameter.

Introduction: Mast cells are involved in a number of biological responses to exocrine and endocrine stimuli, by releasing growth factors and certain cytokines. The aim of this study was to evaluate their number and distribution in experimentally induced benign prostatic hyperplasia in rats. Materials and Methods: Adult Wistar rats (100 days old) were given citral transdermally for 1 month. Morphological characteristics and mast cell concentration were studied in proximal and distal zones after staining with hematoxylin-eosin and Giemsa, respectively. Results: Citral induced mild benign prostatic hyperplasia. Mast cell numbers were increased significantly in both the proximal (2.97 ± 0.52 vs. 1.4 ± 0.17, p = 0.004) and distal zone (2.8 ± 0.68 vs. 1.16 ± 0.11, p = 0.011). Conclusion: Transdermal citral application resulted in a significant increase of mast cell numbers in the stroma of the rat ventral prostate. Furthermore, these mast cells were larger, contained a significant number of intracytoplasmic granules and degranulated. This finding suggests a role for mast cells in the pathogenesis of benign prostatic hyperplasia.

Purpose: Alpha1-adrenergic receptor antagonists may not act solely on smooth muscle contractility. We evaluated the in vivo effect of the alpha1 blocker, terazosin, on the expression of basic fibroblast growth factor (bFGF) in the rat ventral prostate. Methods: Wistar rats were treated with terazosin (1.2 mg/ kg body weight, po, every second day) for 120 days. The expression of bFGF was assessed immuno-histochemically in tissue sections and by Western blotting in whole tissue preparations. Results: Terazosin treatment did not affect prostate weight or histomorphology. In the control group, epithelial and stromal cells demonstrated positive staining for the antibFGF antibody. In contrast, the same staining in terazosintreated specimens was either absent or extremely weak. An analogous difference was observed among the corresponding immunoblots. Conclusions: These findings implicate the reduction of bFGF expression by terazosin as a potential additional molecular mechanism of its action that may include alterations in peptide growth factor mediated prostate homeostasis.Drugs that block the action of sympathetic neurotransmitters on 1-adrenergic receptors ( 1-ADRs) are widely used for the treatment of patients with benign prostate hyperplasia (BPH)-related lower urinary tract symptoms. The rationale for their use stems is that they effectively relax prostate smooth muscles, 1 which represent approximately 40% of the cellular volume in hyperplastic glands. 2 The biological effects of extrinsic factors such as hormones and other endocrine-related agents on the prostate are mediated by various peptide growth factors produced by the gland and influence prostate growth, differentiation and function by promoting inter-and intracellular signaling between and within cell populations, through paracrine, autocrine and intracrine effects. 3 Data from several studies indicate that 1-ADR antagonists may not act solely on smooth muscle contractility. Intact autonomic innervation of the rat ventral prostate is necessary to maintain its structural and functional integrity. [4][5][6] Administration of the sympathomimetic phenylephrine induces ventral prostate hyperplasia associated with reduced rates of cellular apoptosis, but not with increased rates of cellular proliferation. 7 Moreover, rapid proliferation of prostatic epithelial cells has been seen in the spontaneously hypertensive rat, 8 an animal model with in-ORIGINAL RESEARCH