Transient forebrain ischemia induces expression of serine/threonine protein phosphatase 1 mRNA in the vulnerable regions of gerbil brain.

Apoptosis is thought to be implicated in delayed neuronal cell death following transient forebrain ischemia. Recently, apoptosis in neurons induced by an inhibitor of serine/threonine (ser/thr) protein phosphatases (PPs) has been reported. In this study, we investigated the effect of transient forebrain ischemia on the expression of ser/thr PPs in the brain of Mongolian gerbils. At 24 h after 5-min bilateral carotid artery occlusion, Northern blotting analysis revealed the increase of PP1 mRNA expression in the vulnerable CA1 region of the hippocampus and striatum, but not in the cortex and CA3 region. In contrast, the protein level of PP1 detected by Western blotting analysis decreased in all regions. We conclude that the inhibition in PPs expression in the vulnerable regions may affect cell death after transient forebrain ischemia.

Mixed growth hormone cell- prolactin cell pituitary adenoma with acromegaly: α-subunit most growth hormone cells.

A 51 -year-old woman with mixed growth hormone (GH) cell-prolactin (PRL) cell pituitary adenoma is presented. She had clinical signs due to hypersecretion of GH and PRL. Resected tissue was studied immunohistochemically and morphologically. The serial sections revealed that GH and α-subunit were co-localized in most cells, while GH and PRL were localized in different cells.

Silent mixed growth hormone cell-prolactin cell pituitary adenoma.

The case of a 51 -year-old man with recurrent nonfunctioning pituitary adenoma is presented. Despite clinically and endocrinologically normal pituitary function in regard to growth hormone and prolactin, many growth hormone- and prolactin-positive cells were immunohis-tochemically detected in adenoma tissue. Furthermore, a quite rare tumor of silent mixed growth hormone cell-prolactin cell pituitary adenoma was confirmed by the double-labeling immunoelectron-microscopical study.

An Atypical Acidophil Cell Line Tumor Showing Focal Differentiation Toward Both Growth Hormone and Prolactin Cells.

We report a case of giant pituitary adenoma in a child. Computerized tomography (CT) scan revealed a suprasellar extension tumor mass with hydrocephalus. There was no clinical evidence of acromegaly, gigantism, and other hormonal symptoms. Endocrinologic studies showed within normal value of serum growth hormone (GH: 4.2 ng/mL) and slightly increased levels of prolactin (PRL: 78 ng/mL) and other pituitary hormone values were within normal range. On suppression test by bromocryptin, both GH and PRL levels were reduced. Histopathological findings revealed that the tumor consisted of predominantly chromophobic and partly eosinophilic adenoma cells. Immunohistochemical staining detected GH and PRL in a small number of distinctly different adenoma cells, respectively. Nonradioactive in situ hybridization (ISH) also showed GH and PRL mRNA expression in identical immunopositive cells. Electron microscopy (EM) demonstrated adenoma cells with moderate or small numbers of two types of dense granules and without fibrous body which are characteristic of sparsely granulated GH-cell adenomas. The adenoma does not fit into any classification but may be an atypical acidophil cell line tumor showing focal differentiation toward both GH and PRL cells.