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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A middle-aged man presented with weight loss, hypokalemic alkalosis, diabetes, hypertension, and generalized melanosis. Marked elevation of urinary free cortisol (655 micrograms/24 h) and plasma ACTH (2445 PG/ML) SUGGESTED THE DIAGNOSIS OF ECTOPIC ACTH syndrome. The plasma concentrations of cortisol and urinary 17-hydroxycorticosteroids increased paradoxically during the administration of dexamethasone without a corresponding change in the plasma ACTH level. Metyrapone administered over 24 h also markedly incrased both urinary free cortisol and 17-hydroxycorticosteroids. Selective venous sampling of plasma ACTH did not reveal a gradient between jugular vein and peripheral venous blood. The laboratory findings supported the diagnosis of ectopic ACTH syndrome. However, belated occurrence of visual changes necessitated surgical exploration, resulting in the diagnosis of pituitary carcinoma. A fluorescent antibody to ACTH reacted strongly with the atypical pituitary cells. This rare case documents that severe melanosis in Cushing's disease can occur without prior adrenalectomy and is consistent with the diagnosis of pituitary carcinoma. Furthermore, melanosis observed in patients with pituitary carcinoma is associated with ACTH levels similar to those occurrring in the ectopic ACTH or Nelson's syndrome.
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PMID:Pituitary carcinoma mimics the ectopic adrenocorticotropin syndrome. 624 43

VALUE OF AMBULATORY BLOOD PRESSURE MONITORING: Studies that have used ambulatory blood pressure monitoring techniques have shown that the average 24-h or daytime blood pressure values are more closely related to the end-organ damage associated with hypertension than are isolated office readings. IMPORTANCE OF BLOOD PRESSURE VARIABILITY IN PROGNOSIS: More recently, blood pressure variability, measured as the overall 24-h blood pressure standard deviation, has been shown to have a significant relationship to end-organ damage in hypertensive patients. The potential clinical relevance of blood pressure variability has been strengthened in a recent prospective study. The possible prognostic value of blood pressure variability has practical implications for antihypertensive treatment; it may mean, for example, that the optimal antihypertensive drug should reduce not only the mean 24-h values but also the degree of fluctuation in blood pressure. This is more likely to occur with long-acting drugs, which induce a more balanced reduction in blood pressure throughout the 24 h. USE OF THE TROUGH:PEAK RATIO: A proposed measure of a balanced 24-h blood pressure effect is the trough:peak ratio of the blood pressure fall. This ratio can be obtained by clinic blood pressure measurements but ambulatory blood pressure monitoring offers some distinct advantages. One of these advantages is that by revealing the possibility of an excessive fall in blood pressure at the time of the peak effect or an uncontrolled rise at the trough, ambulatory monitoring can also reveal the possible impact of pharmacological treatment on 24-h blood pressure variability.
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PMID:Blood pressure reduction and end-organ damage in hypertension. 770 54

SUITABILITY OF CALCIUM ANTAGONISTS FOR THE ELDERLY: The efficacy and safety of calcium antagonists have been clearly demonstrated in elderly hypertensive patients. In a double-blind placebo-controlled study in 31 elderly hypertensives treated with nicardipine, we found no consistent electrocardiogram changes, nor in the heart rate, plasma levels of potassium, sodium or creatinine, or uric acid; nor did we find any postural hypotension. The mechanism of action of this class of drugs appears to be particularly appropriate in the treatment of elderly patients, in whom hypertension is characterized by an increase in peripheral resistance and a decrease in arterial compliance. Since vascular tone is ultimately controlled by the intracellular calcium concentration in smooth muscles, agents such as calcium inhibitors, which inhibit calcium influx and induce dilation of small and large arteries, are of particular interest. EXPERIMENTAL EVIDENCE: There is some experimental evidence in hypertensive rats and hypercholesterolaemic rabbits that calcium antagonists can provide some protection against atherosclerotic degeneration. However, the validity of extrapolating these findings to humans is still disputed. POSSIBLE CEREBRAL EFFECT: Calcium antagonists might also have a beneficial cerebral effect. The acute administration of these drugs has been shown to increase cerebral blood flow. Moreover, several studies have shown a protective action against cerebral ischaemia and this may be of particular importance in the very elderly.
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PMID:Are calcium antagonists the best option in elderly hypertensives? 779 5

The 11 beta OHSD is an ubiquitous enzyme which inactivates cortisol to cortisone by transforming the hydroxyl group at the 11-carbon to a keto group. Therefore, it confers to mineralocorticoid receptors their selectivity toward their ligand and may constitute an important mechanism of regulation tissue-specific of the access of ligand toward its receptors. More widely the 11 beta OHSD would modulate glucocorticoid activity to their own receptor. There is no possibility to measure directly this enzyme and its deficiency is indirectly evaluated by enhancement of the quotient (THF + alpha THF)/THE after analysis of urinary steroid metabolites. Such enzymatic deficits may be congenital and are observed in childhood where they give an apparent mineralocorticoid excess (AME) syndrome (type 1). Sometimes acquired and reversible, they are due to licorice intoxication, hypothyroidism, chronic alcoholism and may be involved in the genesis of some cases of hypertension.
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PMID:[11 beta-Hydroxysteroid dehydrogenase (11-beta-OHSD): physiology and lack of action in pathology]. 786 84

The following annotated bibliography has been developed for the purpose of providing to primary care physicians a handy source of review articles and major studies in the field of nephrology, hypertension, and fluid and electrolyte disorders. Almost all of the articles are review articles of clinical topics that would be of interest to the practicing physician. JAOA will be publishing additional annotated bibliographies in various fields of internal medicine over the next several months. The second in this series will appear in a forthcoming issue of THE JOURNAL.
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PMID:Nephrology/hypertension/fluid and electrolyte disorders. 842 27

The following annotated bibliography has been developed for the purpose of providing to primary care physicians a handy source of review articles and major studies in the field of nephrology, hypertension, and fluid and electrolyte disorders. Almost all of the articles are review articles of clinical topics that would be of interest to the practicing physician. JAOA will be publishing additional annotated bibliographies in various fields of internal medicine over the next several months. This is the second in the series. Part 1 appeared in the January 1993 issue (93:50-65). Others will appear in forthcoming issues of THE JOURNAL.
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PMID:Nephrology/hypertension/fluid and electrolyte disorders. 851 29

IMPROVING THE TREATMENT OF HYPERTENSION: The results of basic and clinical research in hypertension over the last 30 years have shown that this disease cannot be treated merely by inducing vasodilation and a fall in blood pressure. The development of high blood pressure is associated with changes in carbohydrate and lipid metabolism and with the development of organ damage, mainly of the heart and kidneys. It is now clear that different elements of blood pressure control mechanisms can lead to hypertension, emphasizing the need to select the appropriate type of hypertensive drug in treating different patients. COMBINATION OF CALCIUM CHANNEL ANTAGONISTS AND ANGIOTENSIN CONVERTING ENZYME (ACE) INHIBITORS: Calcium channel antagonists and ACE inhibitors have synergistic effects on sodium and fluid balance and on the renin-angiotensin-aldosterone system. Thus a combination of these two antihypertensive drug classes is likely to be beneficial in certain subgroups of patients with hypertension. Large clinical trials are needed to determine whether this is indeed the case.
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PMID:The pharmacological basis for the combination of calcium channel antagonists and angiotensin converting enzyme inhibitors in the treatment of hypertension. 857 84

The syndrome of apparent mineralocorticoid excess is a form of hypertension inherited in an autosomal recessive manner. This disorder results from mutations in the HSD11K (HSD11B2) gene, which encodes the kidney isozyme of 11beta-hydroxysteroid dehydrogenase. This enzyme converts active glucocorticoids such as cortisol and corticosterone to their inactive metabolites cortisone and 11-dehydrocorticosterone. An elevated ratio of cortisol to cortisone metabolites in the urine (tetrahydrocortisol plus allotetrahydrocortisol to tetrahydrocortisone [(THF+aTHF)/THE]) is considered pathognomic for this disorder. To determine whether the biochemical phenotype of this disorder is correlated with genotype, we expressed enzymes carrying each of the six known missense mutations in cultured cells. Only one mutant, R337C, had detectable activity in cell lysates, but five of six mutants were partially active in whole cells. Apparent kinetic constants for cortisol and corticosterone were determined in whole cells, and the apparent first-order rate constant, Vmax/Km, was used as a measure of enzymatic activity. The urinary (THF+aTHF)/THE ratio in patients carrying each mutation was strongly correlated with in vitro enzymatic activity of the corresponding mutant (r=.839, P=.001 with cortisol as the substrate). We conclude that the biochemical phenotype of the syndrome of apparent mineralocorticoid excess is largely determined by genotype.
Hypertension 1996 Jun
PMID:Apparent mineralocorticoid excess: genotype is correlated with biochemical phenotype. 864 23

DESPITE THE GREATER OBESITY AND PREVALENCE of non-insulin-dependent diabetes mellitus (NIDDM) in Mexican Americans (MA) than in non-Hispanic whites (NHW), MA have a similar or slightly lower prevalence and incidence of hypertension than NHW. After adjustment for age, gender, obesity, and NIDDM, the prevalence of hypertension was significantly lower in MA than in NHW in both men and women. Mexican Americans, however, have lower rates of control than do non-Hispanic whites. The high rates of NIDDM, coupled with the poor control of hypertension in Mexican Americans, make efforts to control hypertension essential in this group. The prevalence of hypertension in low income residents of Mexico City is lower than in low income Mexican Americans from San Antonio, Texas.
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PMID:Hypertension in the San Antonio Heart Study and the Mexico City Diabetes Study: clinical and metabolic correlates. 889 62

THE MEXICAN-AMERICAN POPULATION in the United States has generally elevated frequencies of several chronic conditions, including non-insulin-dependent diabetes mellitus (NIDDM), gallbladder disease, and obesity. Prevalence of cardiovascular disease and hypertension is less clear. To document prevalence and risk factors of hypertension in this population, we measured blood pressure in 1004 randomly selected Mexican Americans in Starr County, Texas, ages 15 to 74. We defined hypertension as systolic blood pressure greater than or equal to 140 mmHg or diastolic pressure greater than or equal to 90 mmHg or current (within the last 48 hours) use of antihypertensive medications. Prevalences by age and gender are elevated in this population group compared with those in the general population. In addition to age and gender, body mass and diabetes status were also predictors of hypertension. Comparison of the Starr County results with those reported from the Third National Health and Nutrition Examination Survey (NHANES III) sampling of Mexican Americans indicates a slight increase in frequency of hypertension in Starr County, while comparison with results from San Antonio Mexican Americans indicates a marked increase in frequency in Starr County. These differences are not simple functions of measurement protocols, but are likely to be caused by differences in population structure, employment and socioeconomic status, education, and other such factors.
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PMID:Hypertension among Mexican Americans in Starr County, Texas. 889 63


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