Anthony H. Vagnucci

Bilateral Massive Adrenal Hemorrhage: Early Recognition and Treatment

PURPOSE To develop a clinical perspective on bilateral massive adrenal hemorrhage and an algorithm for its diagnosis and treatment. DATA IDENTIFICATION Case reports were identified through a computer search using MEDLIN (1976 to 1987), and from bibliographies in review articles (up to 1978). STUDY SELECTION Twelve reports published since 1978 were found. DATA EXTRACTION Data from 20 recently reported cases and 5 cases from personal records were compared with data from 142 previously reported, autopsy-proven cases summarized in a 1978 review article. RESULTS OF DATA ANALYSIS Thromboembolic disease, coagulopathy, and the postoperative state were the three major risk factors. Except for abdominal pain and remittent fever, clinical features were not helpful in diagnosis. A fall in hemoglobin, and progressive biochemical hypoadrenalism were important clues. Diagnosis was confirmed by computed tomography and an absent cortisol response to intravenous corticotropin. Long-term follow-up showed complete atrophy and functional failure of the adrenal gland. CONCLUSIONS Death from bilateral massive adrenal hemorrhage can be prevented by pre-emptive steroid therapy in high-risk patients who have certain clinical and laboratory features.

Gradient inverse weighted smoothing scheme and the evaluation of its performance

Abstract This paper presents an image smoothing scheme for improvement of the quality of noisy pictures. It is an iterative scheme employing a 3 × 3 mask in which the weighting coefficients are the normalized gradient inverse between the center pixel and its neighbors. The smoothing operation tends to clean out noise inside a region without blurring its boundary. In order to evaluate the performance of the proposed scheme, we adopt an f statistic which is based on the analysis of variance. Simulation studies show that this method reduces the gay level scattering within a region, and keeps its mean relatively unchanged. Applications to several real world images are illustrated.

Suckling-Induced Attenuation of Plasma Cortisol Concentrations in Postpartum Lactating Women

The effect of suckling on serum cortisol concentrations was assessed in postpartum lactating women studied during serial breast feeding sessions 1-24 weeks postpartum. The mean +/- SD serum cortisol concentration at 15 min after the start of nursing, 9.8 +/- 3.89 micrograms/dl, was significantly lower, P = 0.001, than prior to the start of nursing, 13.2 +/- 5.92 micrograms/dl. The decline in the serum cortisol concentrations in the breast feeding women was not due entirely to the normal metabolism of the hormone or the normal circadian variation in cortisol secretion. These studies complement and expand upon a recent report [3] of a significant decrease in plasma adrenocorticotrophic hormone in breast feeding women studied one week postpartum. The neuroendocrine mechanisms responsible for this effect in women have yet to be defined.

Digital image enhancement: A survey

Abstract Over decades, many image-enhancement techniques have been proposed. Most of these techniques have been implemented, and their test results have been published. These techniques are surveyed, the underlying concepts briefly described, and their merits discussed. The goal is to help investigators in their selection of enhancement techniques suitable to their needs.

A mechanism for hyporeninemic hypoaldosteronism in chronic renal disease

Abstract Selective aldosterone deficiency in chronic renal disease has been attributed to damage to the renin-producing mechanism. Four patients with selective aldosterone deficiency and chronic renal diseases were studied. These patients had hypertension, increased extracellular fluid volume, and increased total exchangeable sodium, unlikely concomitants of a clinical syndrome in which primary reduction in angiotensin generation led to deficient aldosterone secretion. In two patients who were treated with furosemide to produce sustained diminution in extracellular fluid volume, the gradual increase in plasma renin activity and plasma aldosterone indicated that physiologic suppression, not disease-induced damage, had been preventing elaboration of renin by juxtaglomerular apparatus. Salt and water retention associated with renal disease is proposed as the initial physiologic aberration.

Angiotensin II mediated acth release in rat pituitary cell culture

Anterior pituitaries from normal rats were enzymatically dispersed and placed into monolayer cell culture in order to determine if and how angiotensin II (Ang II) mediates the in vitro release of ACTH and other pituitary hormones. Ang II stimulated ACTH secretion in a time dependent fashion. This release occurred at physiologic concentrations of Ang II and was linearly correlated with the log dose of Ang II. One hour pretreatment of the cells with cycloheximide, a inhibitor of protein synthesis, significantly decreased the cellular ACTH secretory response to Ang II. Ang 11 did not mediate the release of LH nor of ADH, a proposed stimulator of ACTH secretion.

Enhanced sodium appetite in rats with lesions centered on nucleus medianus.

Recent experiments have demonstrated that rats with lesions of the ventral portion of nucleus medianus (vNM) frequently exhibit a chronic and robust hyperdipsia, which occurs only at night. This study indicates that the same brain damage may produce a nocturnal appetite for sodium that is similarly pronounced and persistent. Of 68 rats with vNM lesions, 33 were observed to drink at least 15 ml of 0.51 M NaCl solution per day, and 11 of them consumed more than 30 ml daily. The basis for this impressive consumption of saline is uncertain; the brain-damaged rats had normal sodium concentrations, renin activities, and aldosterone levels in plasma during basal maintenance conditions, and they conserved sodium in urine when maintained on a sodium-deficient diet. Nevertheless, the present results indicate that vNM and/or local fibers of passage may play an important role in the control of sodium appetite, as it does in the control of thirst.

Cushing's disease with intermittent hypercortisolism☆

In a patient with proved pituitary-dependent Cushings syndrome (Cushings disease), 24-hour urinary excretion of free cortisol fluctuated between normal (69 percent of the time, often in the low range and for several days in sequence) and high values. Increased urinary free cortisol excretion occurred unpredictably within the context of a persistent, progressive clinical picture. This case stands in contrast with previous reports of urinary steroid levels varying in a periodic infradiem pattern. Even with normal baseline cortisol indexes, control of the hypothalamic-pituitary axis (as indicated by the suppression test and by the circadian cortisol pattern in plasma) remained abnormal. This patient emphasizes the fact that abnormal control regulation, more than cortisol hypersecretion, is at times indicative of Cushings disease. Hence, sensitive accurate screening requires not only urinary free cortisol measurement (the usefulness of which may be improved by assay of more than one, possibly nonsequential, 24-hour urine sample), but also dexamethasone suppression testing and late-evening plasma cortisol determination, even if baseline indexes are within the range of normal.

Perspectives on the renin-angiotensin-aldosterone system in hypertension☆

Abstract In the syndrome of hyperaldosteronism, the abnormal electrolyte metabolism, secondary to mineralocorticoid excess, seems to play a predominant pathogenetic role in causing elevation of the blood pressure, since the renin-angiotensin system is depressed and unresponsive. The available evidence (results of treatment, consistent failure to cause high blood pressure by administration of excessive salt-remaining steroids to normotensive volunteers, the salt-hypertension model in experimental animals, the higher incidence of adrenal adenomas in hypertensive patients, etc.), however, suggests that other factors participate in the mechanism of hypertension. Angiotensin II stimulates aldosterone secretion, thereby affecting electrolyte balance; in addition, this polypeptide is the most powerful vasoconstrictor known today, the effectiveness of which is greater in a Na-replete condition. In some hypertensive states (renovascular hypertension, end-stage renal disease, malignant phase hypertension, hypertension related to oral-contraceptive medication, and primary reninism) both the renin-angiotensin system and aldosterone production may be elevated. In this group, however, correlation between the latter two variables and hypertension is not sufficiently consistent to implicate them as the sole pathogenetic factors. In the larger group of patients with essential hypertension, the renin-angiotensin-aldosterone system and electrolyte metabolism range from normal to subtle changes (depressed plasma renin, incomplete aldosterone suppression by salt load, decrease in aldosterone metabolism, exaggerated natriuresis, reversal of electrolyte circadian cycle) of difficult interpretation. We suggest that the same factors, clearly abnormal in hypertensive states of more defined etiology, are also at play in causing essential hypertension, perhaps through some as yet undefined abnormal interrelationship.

Time series analysis of hormonal patterns in human plasma

Abstract Methods of time series analysis were applied to half-hourly plasma levels of aldosterone, growth hormone, and renin activity in four normal volunteers and one patient (CH) with aldosterone producing adenoma. The evidence suggests that the hormonal time series of normal subjects are homologous, when their mean levels are made equal; therefore, they can be concatenated in a single series. Analysis in the time domain and in the frequency domain suggest a predominant 24-hr periodicity. Cross-correlation indicates synchrony of aldosterone with renin and of cortisol with corticosterone, suggesting common regulatory mechanisms; it also shows a 5-hr lag difference between the two pairs, indicative of their phase relation. In CH, lag-correlation and spectral analysis of aldosterone, and renin differ from the normal, those of cortisol and of corticosterone are similar to the normal group. These results indicate that time series analysis may be a useful, objective and quantitative approach to the analysis of complex hormonal patterns in plasma.