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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We measured urinary and plasma aldosterone in normal subjects, aged 20 to 59 years, during a period of unrestricted sodium intake and after sodium depletion, using furosemide or a 20 meq sodium diet. Before and after sodium depletion, the mean and the upper limit of the range of urinary aldosterone excretion were considerably lower in subjects over 50 years compared with subjects under 30 years. Aging had no effect on plasma aldosterone concentration when the subjects were on an unrestricted sodium diet and blood was sampled while they were recumbent. In contrast, when the subjects were upright, both before and after sodium depletion, the mean and the upper limit of the range of plasma aldosterone concentration were lower in the subjects over 50 years compared with those under 30 years. The metabolic clearance of aldosterone was the same in the younger and the older subjects. Of eight patients over 40 years of age with aldosterone-producing adenoma, four had normal aldosterone excretion rates when the normal range was not age adjusted, but with age adjustment, all of the patients had clearly elevated excretion rates. Similarly, six of seven patients over 40 years of age had normal upright plasma aldosterone concentrations if the normal range of plasma aldosterone concentration was not age adjusted. We conclude that aldosterone secretion declines with advancing age. The effect of age on aldosterone secretion is an important consideration when evaluating older hypertensive patients for primary aldosteronism.
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PMID:Aging and aldosterone. 633 17

Prostacyclin has been implicated as a mediator of renin release, whereas angiotensin II evokes prostaglandin I2 (PGI2) release from both vascular and nonvascular tissues in vitro. The physiological significance of these observations was assessed by measurement of an index of endogenous prostacyclin biosynthesis in human volunteers during varied activation of the renin-angiotensin system secondary to manipulation of dietary sodium. Excretion of the major urinary metabolite of prostacyclin in man, 2,3-dinor-6-keto-PGF1 alpha (PGI-M), fell from 295 +/- 51 to 176 +/- 35 (+/- SEM) ng g creatinine-1 (P less than 0.01) in 10 normal subjects when sodium intake was decreased from 150 to 10 meq/day. In five patients with primary hyperaldosteronism, PGI-M fell from 199 +/- 34 ng g creatinine-1 preoperatively to 120 +/- 26 pg/mg creatinine-1 after removal of the adenoma. In such patients, the reduction in PGI-M was associated with a significant increase in PRA. Thus, in both normal subjects and patients with hyperaldosteronism, PGI-M excretion fell rather than increased with activation of the renin-angiotensin system. This suggests that systemic biosynthesis of PGI2 is unrelated to renin release and that angiotensin II is unlikely to stimulate endogenous prostacyclin biosynthesis under these conditions in man.
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PMID:Endogenous prostacyclin synthesis is decreased during activation of the renin-angiotensin system in man. 636 36

Following 7 days on a low sodium diet, a regular sodium diet or a high sodium diet each, urine samples were collected from 37 subjects in the final days of each sodium treatment. Urinary kallikrein excretion was determined in 9 patients with primary aldosteronism, 15 normal subjects and 13 patients with essential hypertension. Urinary aldosterone excretion, plasma renin activity (PRA), urinary sodium excretion, urinary potassium excretion and p-aminohippuric acid clearance were also determined on the same days. Levels of urinary kallikrein excretion in patients with primary aldosteronism due to aldosterone-producing adenoma (APA) were greater (p less than 0.05 to p less than 0.001) than those in patients with primary aldosteronism due to idiopathic adrenal hyperplasia (IHA) under any sodium diet. Other examined variables were of limited value in differentiating patients with APA from those with IHA. Urinary kallikrein excretion, urinary excretion of electrolyte, urinary aldosterone excretion, PRA and PAH clearance were similar in normal subjects and patients with essential hypertension. It appears reasonable to conclude from these data that urinary kallikrein does not play an important role in the pathogenesis of essential hypertension, and elevated urinary kallikrein excretion in patients with primary aldosteronism due to APA can be used for biochemical differentiation from those with IHA.
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PMID:Urinary kallikrein excretion in patients with primary aldosteronism: differentiation of adrenal adenoma from idiopathic adrenal hyperplasia. 637 65

A 47-year-old woman with normotensive primary aldosteronism is reported. In this case, hypopotassemia was found, but the patient's blood pressure was within the normal range. Her condition was diagnosed as primary aldosteronism without hypertension, which is very rare, based on an increased level of plasma aldosterone concentration, low plasma renin activity, and a typical finding of aldosterone-producing adenoma by adrenal scintigraphy. In the present case, similar values for urinary volume, renal function, plasma aldosterone concentration, plasma renin activity, plasma volume, total exchangeable sodium, urinary kallikrein excretion and a similar weight of the resected adenoma, but a shorter duration between the onset of symptom and hospital admission were observed as compared with those in 13 previously experienced cases of primary aldosteronism with hypertension. Thus, a shorter duration of primary aldosteronism appears to be an important factor in explaining the mechanism of normotension. However, we were unable to reach a definite conclusion and this is only a hypothesis. Further investigation will be required to clarify the mechanism of normotension in primary aldosteronism.
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PMID:A case of normotensive primary aldosteronism--comparison with 13 previously experienced cases with hypertension. 637 8

A sodium loading test was performed in 35 patients presenting with hypertension and hypokalemia. In 14 of these patients, intravenous administration of 0.9% saline (2 l in 4 h) on two consecutive days caused urinary aldosterone excretion to fall to values within the range for normal volunteers. The other 21 patients, in whom urinary aldosterone excretion did not decline following two days of saline loading, or in whom pronounced hypokalemia after the first day of loading precluded further saline infusion, were designated as having primary aldosteronism. Seventeen of this group underwent surgery and discrete adrenal adenomas were found in 16. When serum potassium concentration, plasma renin activity or the relationships of serum potassium to concurrent urinary potassium excretion or of urinary aldosterone excretion to plasma renin activity were used as alternative diagnostic criteria for primary aldosteronism, overlapping of the two groups occurred. It is concluded that measurement of urinary aldosterone excretion after intravenous sodium loading is a useful test in the test in the identification of primary aldosteronism due to aldosterone-producing adenoma. In this series the saline loading test was more specific in diagnosis than criteria based on serum and urinary potassium, plasma renin activity or unsuppressed aldosterone excretion.
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PMID:Use of an intravenous sodium load in screening for primary hyperaldosteronism. 638 49

Normal subjects, normal-renin hypertensive patients, and low-renin hypertensive patients were evaluated by intravenous saline infusion and with a fludrocortisone acetate (Florinef) protocol to clarify diagnostic criteria for primary aldosteronism that are recommended for the saline infusion protocol. The patients consumed a 200 mEq sodium, 70 mEq potassium diet for 6 days, and on the last 3 days received Florinef 0.5 mg orally twice daily. On Days 3 and 6, urinary aldosterone and tetrahydroaldosterone excretions were determined, and on Days 4 and 7 plasma aldosterone (PA) was determined at 0600 after overnight recumbency and at 0800 after 2 hours of walking. Although the level of normal PA suppression by saline infusion has been commonly defined as 10 ng/dl, a value of 5 ng/dl was originally recommended. In 20 normal subjects and 45 normal-renin hypertensive patients, we found that the PA was almost always suppressed below 5 ng/dl. In 18 of 75 low-renin patients including five with aldosterone-producing adenoma (APA), the PA was never suppressed below 10 ng/dl; thus, these 18 patients had classical primary aldosteronism by generally accepted criteria. The Florinef protocol was performed in eight of these 18 patients and was abnormal in all. An abnormal Florinef protocol was also found in seven of 15 patients studied with PA suppression after saline infusion to between 5 and 10 ng/dl, but in only one of 24 patients studied with PA suppression below 5 ng/dl. Additional studies in the subgroup with abnormal results from the Florinef protocol indicated that none of these patients had evidence of APA, so they had nontumorous primary aldosteronism (NTPA).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Further evaluation of saline infusion for the diagnosis of primary aldosteronism. 638 37

The promoting effects of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and sodium L-ascorbate on two-stage carcinogenesis initiated with methylnitrosourea (MNU) in F344 male rats were investigated. Animals were given injections of MNU (20 mg/kg ip) twice a week for 4 weeks, and then basal diet containing 2% BHA, 1% BHT or 5% sodium L-ascorbate for the next 32 weeks. Administration of BHA, BHT or sodium L-ascorbate in the diet significantly increased the incidences per group and numbers per rat of papilloma and papillary or nodular hyperplasia of the urinary bladder, and BHA and BHT also increased the number of cancers per rat. Furthermore BHA significantly increased the incidences of cancer and papilloma in the forestomach of rats initiated with MNU, whereas treatment with BHA alone was associated with papilloma but no carcinoma development in the rat forestomach. The incidence of adenoma, but not adenocarcinoma, of the thyroid was significantly increased by treatment with MNU plus BHT. These results show that BHA, BHT and sodium L-ascorbate have promoting activities on urinary bladder carcinogenesis in rats initiated with MNU, and that BHA also has a promoting effect on forestomach carcinogenesis after initiation with MNU.
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PMID:Promoting activities of butylated hydroxyanisole, butylated hydroxytoluene and sodium L-ascorbate on forestomach and urinary bladder carcinogenesis initiated with methylnitrosourea in F344 male rats. 650 Feb 33

Retrospective study on diagnosis and management during the perioperative period of patients with adrenal tumors who underwent adrenalectomy in the Second Department of Surgery Kyoto University, from 1960 to 1983, was carried out. Most of the patients presented with functioning tumors; primary aldosteronism (43 cases), Cushing's syndrome (53 cases), pheochromocytoma (39 cases), and DOC-producing tumor (1 case), whereas, only 3 cases were non-functioning adenoma and cyst. Although recent development of CT has permitted easy and non-invasive diagnosis of adrenal tumors, aldosterone-producing tumors may be overlooked due to their small sizes, because their CT value is identical to that of fatty tissue. Moreover, blood sampling from vena cava at various levels is also necessary in patients with extra-adrenal pheochromocytomas. The preoperative control of blood pressure by alpha- and beta-adrenergic blocking agents was a prerequisite, and the clinical course was uneventful following intraoperative additive use of sodium nitroprusside in patients with pheochromocytoma. Autotransplantation of the adrenal cortex into the rectus muscle was performed in three patients with bilateral pheochromocytoma and two of them could return to work. Non-functioning adrenal tumors have been found increasingly by routine CT study without previous suspicion and the surgical indication of these tumors must be discussed in more detail in the future.
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PMID:[Current problems in adrenal surgery]. 650 58

The whole body content of sodium, potassium, chlorine, calcium, phosphorus and nitrogen was measured by neutron activation analysis in 13 patients with untreated primary hyperaldosteronism (Conn's syndrome; aldosterone-secreting adenoma). Concurrently, exchangeable sodium and potassium were estimated by isotope dilution. Results were compared with values in the same patients during treatment with potassium-conserving diuretics and again after removal of the adenoma; and also with those in a series of 30 patients having untreated essential hypertension. Both total body and exchangeable sodium were high in Conn's syndrome before treatment and were reduced by spironolactone or amiloride and by subsequent surgery. There was no evidence of alteration in the proportion of non-exchangeable sodium in this disease, in contrast to earlier reports. Total body and exchangeable potassium were low in untreated Conn's syndrome and increased to normal after therapy: the proportion of non-exchangeable potassium was similar before and after treatment, and also similar to that in essential hypertension. Total body chlorine was increased before treatment in Conn's syndrome and returned to normal with therapy; body calcium, phosphorus and nitrogen were normal throughout.
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PMID:Body elemental composition, with particular reference to total and exchangeable sodium and potassium and total chlorine, in untreated and treated primary hyperaldosteronism. 653 85

Clinical, operative and pathological findings in a series of 18 patients with aldosterone producing adrenal cortical adenomas are reviewed. All patients presented with hypertension and hypokalaemia. The main challenges in preoperative diagnosis were to differentiate primary aldosteronism from other causes of hypokalaemia, such as diuretic therapy, to establish the presence of a discrete adenoma and to localize the tumour to the left or right adrenal gland. A high rate of success was achieved in predicting a surgical diagnosis of aldosterone-producing adenoma. This was attributed to thorough biochemical evaluation of the underlying metabolic state by measurement of renal potassium handling and by determining the responses of the renin-aldosterone axis to changes in sodium balance. Preoperative tumour localization, using adrenal phlebography or scintiscanning, was accomplished in only eight cases. Our experience suggests that the transabdominal approach is preferable for cases in which a unilateral lesion is not clearly identified by imaging techniques.
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PMID:Surgical management of primary aldosteronism (Conn's syndrome), a correctable cause of hypertension. 659 66


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