Hiroyuki Onose

Ectopic corticotroph adenoma in the cavernous sinus: case report.

OBJECTIVE AND IMPORTANCE Adrenocorticotropin (ACTH)-secreting pituitary adenomas causing Cushings disease are often difficult to identify because of their variable locations and their small size. This report presents histological evidence of an ectopic ACTH-secreting adenoma located entirely within the cavernous sinus. CLINICAL PRESENTATION A 62-year-old woman presented with central obesity, hypertension, and osteoporosis. Endocrinological evaluation suggested the presence of an ACTH-secreting pituitary adenoma; however, imaging studies, including dynamic magnetic resonance imaging, did not reveal any visible lesions in the pituitary gland. Bilateral cavernous sinus sampling demonstrated a large central/peripheral ACTH gradient, with a right/left ACTH gradient. The patient was treated as having pituitary-dependent Cushings disease, until she died suddenly as a result of acute respiratory failure. INTERVENTION In a postmortem histological examination, an ACTH-secreting adenoma was found in the right cavernous sinus, which was completely surrounded by dura mater and had no direct connection with the pituitary gland. CONCLUSION Although they are rare, such adenomas located in the cavernous sinus should be recognized as one of the reasons for inaccurate cavernous sinus sampling and the failure of transsphenoidal surgery for patients with ACTH-dependent Cushings syndrome.

Growth factors increase pericellular proteoglycans independently of their mitogenic effects on A10 rat vascular smooth muscle cells.

Proliferation of vascular smooth muscle cells with the accumulation of proteoglycans in the extracellular matrix is one of the significant changes found in atherosclerotic lesions. In order to clarify the relationship between pericellular proteoglycan and cell growth, we established a simple method for quantitatively estimating the amount of pericellular proteoglycans and investigated the effects of various growth factors on the synthesis of pericellular proteoglycans by cultured A10 rat smooth muscle cells. Analysis of trypsin accessible [35SO4]-labeled material in the pericellular area of the A10 cell culture by Q-sepharose anion-exchange chromatography showed two peaks. One peak, eluted at 0.55 M NaCl, disappeared after treatment with 2 mU/ml of heparitinase, indicating that heparan sulfates (HS) were present. The other peak, which eluted at 0.65 M NaCl, disappeared with 20 mU/ml of chondroitinase ABC, indicating the presence of chondroitin sulfates and dermatan sulfates (CS/DS). We estimated the effects of several growth factors on the synthesis of the pericellular proteoglycans by measuring heparitinase- and chondroitinase-ABC-sensitive radioactivities. Although PDGF-AB significantly stimulated cell proliferation and the synthesis of pericellular CS/DS, its dose-dependent effect on the cell growth did not coincide with that on the proteoglycan synthesis. IGF-I (1 nM) increased pericellular CS/DS but not the cell number, while basic FGF (1 nM) and EGF (1 nM) increased the cell number but not pericellular CS/DS. All the growth factors we examined had no effect on the synthesis of pericellular HS. These results indicate that growth factors increase pericellular proteoglycans independently of their mitogenic effects.

Effect of d-Ala-d-βNal-Ala-Trp-d-Phe-Lys-NH2 (KP-102) on GH secretion in urethan-anesthetized rats

The effect of a newly developed growth hormone (GH)-releasing hexapeptide (KP-102) on GH secretion was studied in urethan-anesthetized adult male rats. Although KP-102 alone exerted a small influence on GH secretion, it produced a large plasma GH response in the presence of exogenous GH-releasing factor (GRF). During the continuous infusion of GRF, the somatotropes became refractory to a large bolus dose of GRF, but KP-102 induced a marked increase of plasma GH. The GH response to KP-102 alone or KP-102 with GRF was significantly augmented when antiserum to somatostatin (ASS) was previously administered. Although KP-102 and GRF acted synergistically on GH secretion in control animals, they acted additively in ASS-administered rats. The KP-102 effect on plasma GH was significantly attenuated in control animals and ASS-administered rats by prior i.v. injection of antiserum to GRF. Taken together, KP-102 stimulates GH secretion dependent on GRF and appears to act synergistically with GRF by antagonizing the SS effect.

Utilization of three-dimensional computed tomography for papillary thyroid carcinoma arising in the thyroglossal duct remnant: report of a case.

This report presents a rare and interesting case of papillary thyroid carcinoma arising in a thyroglossal duct remnant (TDR) that was diagnosed by three-dimensional computed tomography (3DCT). The patient, a 61-year-old woman, presented with a painless mass in the anterior suprahyoid region that had gradually enlarged over a 2-year period. Three-dimensional CT successfully revealed the thyroglossal duct (TD) descending from the tumor to the isthmus of the thyroid. An ultrasonography-guided fine-needle aspiration biopsy of the tumor was positive for carcinoma. A total thyroidectomy was performed in addition to the Sistrunk procedure. The histological findings indicated papillary thyroid carcinoma arising in the TDR and thyroid papillary microcarcinoma in the left thyroid lobe. The patient underwent radioactive iodine ablation and thyroid suppression therapy. This is apparently the first reported case of papillary thyroid carcinoma arising in a TDR evaluated using 3DCT. Three-dimensional CT was able to clarify the relative locations of the tumor, TD, and thyroid in the present case, and visualization of the TD allowed a definitive preoperative diagnosis that would not otherwise have been possible using conventional imaging techniques. This case suggests that 3DCT may therefore play an important role in providing definitive information on patients with anterior neck masses that are difficult to diagnose.