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Intramedullary spinal cord metastasis (ISCM) is an unusual occurrence in systemic cancer, occurring in as few as 2% of autopsy cases and also represents 8.5% of all cases of central nervous system metastases. Although ISCM from small cell lung carcinoma is well documented, ISCM from non-small cell lung carcinoma of the lung is rarely diagnosed prior to the patients' demise and very little data regarding outcomes exists in such patients. We present the results of our observational case series to better delineate the presentation and clinical course of this uncommon entity which shows that ISCM may present atypically and should be considered in any patient with a previous history of bronchogenic carcinoma and neurologic symptoms.

The adrenomedullin gene encodes two potent hypotensive peptides, adrenomedullin and proadrenomedullin NH(2)-terminal 20 peptide. As with other vasoactive peptides, the most difficult challenge is to prove the physiological relevance of their recognized pathological and pharmacological actions and to establish, against that physiological background, their therapeutic potential.

Neural and humoral mechanisms controlling fluid and electrolyte homeostasis employ a diverse array of physiologic mechanisms that often, when aberrant, are the underlying cause of disease. Behavioral, hormonal, renal, and vascular responses to volume and osmotic challenges must be coordinated to achieve the goal of homeostasis. In recent years, it has become apparent that there exist a number of hormonal factors produced throughout the body that can coordinate these multiple regulatory mechanisms by complementary effects in several tissues. Thus, in addition to their vasoactive properties, recently characterized hormones such as the natriuretic peptides and the endothelins, as well as the better established renin-angiotensin system, exert central nervous, renal, cardiac, and pituitary effects that regulate normal fluid and electrolyte balance. Now a new player, adrenomedullin, has been added to the cast, and the interplay of multiple hormonal factors involved in the physiology and pathophysiology of volume and osmotic status continues to be elucidated.

The potent hypotensive peptide, adrenomedullin (AdM), originally isolated from a human pheochromocytoma is present in a variety of rat and human tissues. We examined its potential effects in anterior pituitary gland, reasoning that it may be a feedback regulator of adrenocorticotropin (ACTH) secretion. Rat AdM11-50 inhibited basal ACTH secretion from dispersed, rat anterior pituitary cells in a significant, dose-related fashion (maximum inhibition at 10(-9) M). Rat AdM11-50 also inhibited, in a dose-related fashion, corticotropin releasing hormone (CRH)-stimulated ACTH secretion, but did not block the ability of CRH to stimulate cAMP accumulation in these cells. These findings suggest that in addition to peripheral actions in the vasculature and kidney, adrenomedullin may act within the anterior pituitary gland to control fluid and electrolyte homeostasis.

Release of oxytocin into the vicinity of the long portal vessels connecting the hypothalamus with the anterior pituitary gland and the presence of short portal vessels connecting the posterior lobe to the anterior pituitary established the potential for the peptide to act in a neuroendocrine fashion controlling the release of one or several adenohypophyseal hormones. Indeed, oxytocin receptors are present in the gland and numerous trophic effects of the peptide have been described, some with apparent physiological relevance. Thus under defined physiologic conditions a participatory role for oxytocin in the physiologic regulation of at least two hormones, prolactin and adrenocorticotropin, has been evidenced and there is developing credence to the concept that oxytocin may indirectly control gonadotroph function as well. Most recently, novel technologies have identified subpopulations of oxytocin receptive cells within a given cell type in the anterior pituitary gland and the concept of a modulatory effect of the nonapeptide on primary regulatory events has arisen.

Reliable measurement of the reduced and oxidized forms of ascorbic acid (AA) is challenging because they are highly reactive and unstable compounds. Detection of small amounts of AA and dehydroascorbic acid (DHAA) is essential for determining the biochemical function of the vitamin. While a variety of techniques exist for measurement of AA with detection limits in the millimolar range, a need exists for highly reliable assessment of picomolar levels of AA and DHAA in tissues. The present study presents a method for measuring AA and DHAA that combines high performance liquid chromatography with the advantages and increased detection limits and selectivity available with coulometric electrochemical detection. The difference between AA and "total AA" in tissue samples gives an assessment of DHAA concentration. Verification of the reliability of the assay is by the successful linear recovery of exogenously added AA and DHAA in tissue homogenate. Optimal conditions for reducing DHAA in tissue samples include a pH of 7.2, reaction time of 10 min, reaction temperature equal to room temperature, and a 10 mM concentration of the reducing agent, beta-mercaptoethanol. AA and DHAA are measured in several mammalian tissues using the method presented.