The New England journal of medicine
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Randomized Controlled Trial Clinical Trial
Vitamin C and acute illness in Navajo schoolchildren.
To evaluate earlier observations, including our own, showing usefulness of vitamin C for managing the common cold, we performed a double-blind trial of vitamin C versus placebo in 868 children. There was no difference in number becoming ill (133 versus 129), number of episodes (166 versus 159) or mean illness duration (5.5 versus 5.8 days) between the groups. ⋯ Children with high plasma ascorbic acid concentrations had longer mean illness (6.8 versus 4.0 days, P less than 0.05) than those with low levels. Vitamin C does not seem to be an effective prophylactic or therapeutic agent for upper respiratory illness.
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Two sources of funds are available to underwrite the costs of any national health-insurance plan: prepayments (premiums, payroll taxes and income taxes) and out-of-pocket payments (coinsurance and deductibles). The extent to which taxes rather than premiums are used to finance an insurance program will be the major determinant of how large a share of the costs of health care will be borne by higher-income groups. The extent to which coinsurance and deductible provisions are reduced or waived for low-income persons will have a less important, but still substantial, role in determining how the costs of a program are distributed. These financing principles, once understood, provide a basis for the design of health-insurance legislation that will achieve any pattern of income redistribution that may be desired.
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Case Reports
Acute myeloblastic leukemia and hypercalcemia. A case of probable ectopic parathyroid hormone production.
We studied a patient with acute myeloblastic leukemia, hypercalcemia, hypophosphatemia and inappropriately elevated serum parathyroid hormone levels to define the mechanism of the hypercalcemia. On six occasions during two years, hypercalcemia occurred in conjunction with relapses of leukmia. Each time, serum calcium decreased to normal levels in parallel with reduction of the leukemic mass. ⋯ In addition, hormone was detected in vitro after short-term incubation of the leukemic cells (after 24 hours, the patient's cells produced 129 pg of PTH per milliliter, whereas myeloblasts from a normocalcemic patient with leukemia produced only 33 pg). In freeze-thawing experiments, 39 pg of parathyroid hormone was released form 1 x 108 of the patient's myeloblasts; no hormone was released from the normocalcemia cells. These findings suggest that the hypercalcemia resulted from ectopic parathyroid hormone production by leukemic cells.