George T. Tindall

Cushing's Disease Associated with an lntrasellar Gangliocytoma Producing Corticotrophin-Releasing Factor

A 58-year-old woman had Cushings disease with elevated plasma adrenocorticotrophin and an intrasellar tumor. Light microscopy showed that the tumor was a gangliocytoma containing immunoreactive corticotrophin-releasing factor accompanied by pituitary corticotroph hyperplasia. Ultrastructural examination identified an intimate association and desmosomal attachments between interdigitating cell processes of neurons and corticotrophs. It is suggested that Cushings disease was due to the effect of corticotrophin-releasing factor on corticotrophs; this case represents a syndrome supporting the concept that, in some patients, Cushings disease may have a hypothalamic origin.

Pituitary Adenomas Producing Growth Hormone, Prolactin, and One or More Glycoprotein Hormones: A Histologic, Immunohistochemical, and Ultrastructural Study of Four Surgically Removed Tumors

The morphologic features of four pituitary adenomas, removed from 2 men and 2 women between 31 and 62 years of age, are reported. The tumors contained growth hormone (GH), prolactin (PRL), and one or more glycoprotein hormones--usually thyrotropin (TSH). Three tumors were associated with acromegaly and one with hyperprolactinemia. Hyperthyroidism was not evident in any of the patients. In the tumors of acromegalic subjects, GH-containing cells were the most numerous, whereas PRL cells were dominant in the adenoma accompanied by hyperprolactinemia. Electron microscopy revealed plurimorphous tumors comprised of various proportions of morphologically different cell types: densely granulated GH cells, TSH-like cells, and the less common mammosomatotrophs and PRL cells. It is suggested that pituitary adenomas producing GH, PRL, and glycoprotein hormones derive from the same precursor; their immunocytochemical profile, fine structural appearance, and endocrine function may depend on the degree and direction of the cellular differentiation.

Pituitary tumors composed of adenohypophysial adenoma and Rathke's cleft cyst elements: a clinicopathological study.

Nine cases of pituitary tumors composed of mixed tissue elements of adenohypophysial adenoma and Rathkes cleft cyst are reported. All cases were associated with hyperprolactinemia and were managed by transsphenoidal adenomectomy with good results. The clinical and pathological features are presented, and embryological pathogenesis for the occurrence of this unique association is discussed in connection with the high incidence of immunoreactive S-100 protein cells identified in tumor tissues. Patients with this kind of pituitary tumor can be managed in the same fashion as patients with other types of pituitary adenoma.

Isolated histiocytosis X of the pituitary gland: case report

The authors describe a case of a granuloma of histiocytosis X localized in the pituitary gland. The patient presented with diabetes insipidus and hyperprolactinemia. The diagnosis was established by surgical removal of the pituitary lesion through a transsphenoidal approach. The clinical and pathological aspects of the case are discussed.

Benign Hemangioendothelioma Involving the Central Nervous System“Strawberry Nevus” of the Neuraxis

Benign hemangioendothelioma is rarely included in discussions of vascular neoplasms involving the central nervous system, whereas it is a well-defined entity outside the neuraxis. We present four cases of benign hemangioendothelioma, including an infantile hemangioendothelioma with venous drainage into the transverse dural sinus, an intracranial hemangioendothelioma adherent to the falx cerebri, a spinal epidural hemangioendothelioma causing spinal cord compression, and a parasellar hemangioendothelioma. Although hemangioendothelioma resembles hemangioblastoma in some ways, it is a distinct entity differing from the other vascular lesions involving the central nervous system.

Augmentation of Cerebral Blood Flow Induced by Hemodilution in Stroke Patients after Superficial Temporal-Middle Cerebral Arterial Bypass Operation

Experimental hemodilutional therapy has been shown to raise collateral perfusion to acutely ischemic brain regions distal to occluded internal carotid (ICA) and middle cerebral (MCA) arteries and to reduce infarct size. Superficial temporal (STA)-MCA anastomosis surgically establishes additional regional collateralization, and this bypass angiographically enlarges over time. Despite bypass patency verification by Doppler recording made at the edge of the craniectomy, the microsurgical STA-MCA anastomosis in 11 stroke patients did not produce early changes in cerebral perfusion parameters in the MCA territory of either hemisphere as determined by 133xenon inhalation. Therefore, hemodilution was initiated in an effort to increase cerebral perfusion during this marginal period when the STA was beginning to dilate progressively. Incremental venesections with equal intravenous volume replacement with 5% human serum albumin caused a significant lowering of the hematocrit from 40 +/- 1 to 33 +/- 1%. This isovolemic hemodilutional therapy resulted in significant mean regional cerebral blood flow (rCBF) elevations of 23 +/- 5% (SE) in the bypassed MCA territory and of 25 +/- 6% in the opposite MCA region. The mean gray flow (F1) in the involved and homologous MCA regions significantly increased 27 +/- 8% and 30 +/- 11%, respectively. Similarly, the initial slope index (ISI2) significantly rose by 17 +/- 5% in the bypassed MCA territory and by 18 +/- 6% in the homologous region. These data objectively support the premise that reductions in hematocrit without intravascular volume expansion augment cerebral blood flow, probably by reducing blood viscosity.(ABSTRACT TRUNCATED AT 250 WORDS)

Direct hypophysial inhibition of luteinizing hormone release by dopamine in the rabbit.

Abstract The role and site of action of dopamine in regulating gonadotropin secretion remain unclear. In the present study, we investigated the possibility that dopamine regulates LH secretion by acting directly on the pituitary gland of the rabbit. The effect of dopamine infusion on LHRH-evoked LH release was determined in intact and pituitary stalk sectioned animals. Intravenous injection of LHRH (1 μg) in intact and acutely stalk sectioned rabbits increased peripheral plasma LH levels from a resting value of 0.2 ng/ml to maximal values of 12–14 ng/ml within 10–20 min. When dopamine was infused iv at a dose of 6.6 μg/min/kg BW from 30 min before LHRH injection until 120 min after, the rise in plasma LH levels in intact and stalk sectioned animals was decreased by 50–70%. However, dopamine infused at a lower dose (0.66 μg/min/kg BW) or at a higher dose (66.0 μg/min/kg BW), did not affect the LHRH-induced secretion of LH. These results suggest that dopamine can exert a direct hypophysial inhibitory effect on release of LH. They also demonstrate that dopamine is inhibitory only within a restricted dose-range, extending to the pituitary an established property of dopamine in the cardiovascular system.

Chapter 67 Preliminary report on adrenal medullary grafting from the American Association of Neurological Surgeons Graft Project

Publisher Summary This chapter examines the preliminary report on adrenal medullary grafting from the American Association of Neurological Surgeons Graft Project. This data is preliminary and subject to alteration as further data is accumulated and analyzed. It is not part of a controlled study but is the collection of clinical experience of the participants. Therefore, the data has been cautiously analyzed relative to the experience being described. The data is discussed in the chapter in various subgroups and not as a single unit or net result. It would be inappropriate to describe an overall complication rate, because the patient selection criteria, surgical procedure, and evaluation criteria vary with each center. In the chapter, rather than discussing an overall complication rate, complication rates are discussed for various types of patient characteristics and surgical procedures. The data are meant to provide a framework to evaluate the current state of the art of transplantation and provide insight into the direction for future studies.

Supratentorial subarachnoid epithelial cyst: case report and ultrastructural study.

Supratentorial epithelial cysts are rare entities that have evoked controversy regarding their pathogenesis. Recent ultrastructural studies have failed to resolve this controversy. We present a case report and an ultrastructural study of such a cyst. The cyst wall was lined by columnar epithelial cells with prominent cilia and microvilli at their apical surface. They were joined by well-developed junctional complexes and contained abundant intracytoplasmic, electron-dense, granular material, some of which was membrane-bound. These ultrastructural findings suggest that epithelial cysts are derived from elements of the embryological tela choroidea.

Increased LH Secretory Response to LHRH After Hypophyseal Stalk-Transection of Monkeys

Luteinizing hormone-releasing hormone (LHRH) will evoke large increases of circulating LH in all species tested except for the rhesus monkey. Indeed, in the present study we found that an intravenous injection of a relatively large dose of LHRH (20 micrograms) evoked only a small (2.2-fold) increase in plasma LH levels, as measured by the dispersed interstitial cell bioassay in 4 intact follicular phase monkeys. In contrast, 4 stalk-transected animals exhibited a significantly greater (19.9-fold) increase in plasma LH levels when treated with 20 micrograms of LHRH within 1 week after surgery. Qualitatively similar differences in responsiveness also existed between the two treatment groups with respect to FSH secretion. 2 stalk-transected monkeys treated with LHRH at weekly intervals for the first 4 weeks after surgery showed progressive declines in the LH secretory response approaching, eventually, that observed in intact animals. In 3 additional monkeys, initiation of estrogen maintenance therapy within 3 h of stalk transection, to achieve mid-follicular phase plasma levels of estradiol, totally abolished hyperresponsiveness to LHRH. Thus, the results of this study demonstrate that a transient increase in pituitary responsiveness to LHRH occurs after hypophyseal stalk transection in rhesus monkeys. Although the results indicate that this phenomenon can be accounted for, in large part, by the absence of estrogen feedback, they do not preclude the possibility that factors other than LHRH and gonadal steroids regulate gonadotropin secretion in monkeys.