Alterations in red blood cell (RBC) Na+,K+ pump and in Na+,K+ cotransport (CoT) have been described in essential hypertension (EH). We examined pump and CoT in 50 normotensive (NT) subjects and 58 EH subjects subdivided by race and family history of hypertension (+ FH). RBCs were preloaded with Na+ to obtain intracellular levels of 25 mM/liter cells by using the p-chloromercuribenzene sulfonic acid (pCMBS) method. Na+ and K+ efflux rates into a magnesium-sucrose medium were quantitated in the presence of ouabain and ouabain plus furosemide to define pump and CoT activity respectively. Mean intracellular Na+ content was higher (p less than 0.05) in black NT and HT subjects compared to Caucasians. Mean RBC CoT was lower in black EH compared to NT and compared to Caucasian NT and HT subjects. Conversely, Caucasian HT patients had higher mean CoT than NT subjects. Subdivision into + FH revealed very little effect of + FH on CoT in black NT and HT subjects. In Caucasian NT and HT subjects with + FH, mean CoT was significantly reduced (less than 0.3 mM/liter cells/hr) compared to those without + FH. A subgroup of Caucasian EH subjects displayed high CoT (greater than 0.6 mM/liter cells/hr); a + FH had little impact on the high CoT group. There was no correlation between RBC CoT activity and age, sex, severity of hypertension, urinary sodium excretion, and plasma aldosterone. There was a positive correlation (r = + 0.47; p less than 0.01) between CoT and upright plasma renin activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

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A maternity cooperative that works.

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Cooperative Behavior↗

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Effect of frequent blood transfusions on steroid determinations in newborn infants.

The birth of an infant with ambiguous genitalia constitutes a medical emergency. Ill infants with ambiguous genitalia often require blood transfusions. We studied steroid levels in packed red blood cells from 10 healthy adult donors to determine whether packed red blood cells contain significant amounts of donor steroids that might interfere with hormonal testing. Levels of cortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, aldosterone, and dihydrotestosterone were well below normal newborn values. Hemolyzed packed red blood cells were used to provide the maximum possible donor steroid contribution. The concentration of testosterone was substantial in hemolyzed packed red blood cells but was effectively reduced to below normal female newborn levels by washing packed red blood cells by a standard blood bank procedure. Corticotropin testing for evaluation of adrenal function can be done accurately, even in infants receiving frequent transfusions of packed red blood cells. To avoid any misinterpretation of testosterone levels, it might be prudent to use washed packed red blood cells during human chorionic gonadotropin testing to evaluate Leydig cell function.

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Is dentistry destined to follow medicine in managed care?

Our professional calling is to assist our patients in reaching and maintaining a state of good oral health. If managed care assists in that effort, that's good. However, if we can identify and eliminate poor dental HMOs and identify the quality plans, dentistry will begin to realize that keeping people well can be as financially and professionally rewarding as treating disease. Is dentistry headed down the same path as medicine? Unfortunately, the answer is not clear. What is clear is that managed care is here and will impact significantly on dentistry, both positively and negatively. An opportunity exists to mold managed care into a form that is acceptable to dentists and improve the oral health of Americans on a cost-effective basis. However, we as dentists must act, and react, in a rational and logical manner if we are to have a voice in shaping the future of dental benefits and how they will be provided.

Economic Competition↗