Calcified tissue international
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Calcif. Tissue Int. · Dec 1992
Serum intact parathyroid hormone levels in elderly Chinese females with hip fracture.
Serum intact parathyroid hormone (PTH), 25 hydroxyvitamin D(25OHD), 1,25 dihydroxyvitamin D (1,25(OH)2D), albumin, and ionized calcium were measured in 61 Chinese female patients with hip fracture and 61 control subjects. Hip fracture patients had low albumin, ionized calcium, and 250HD levels. Serum PTH and 1,25(OH)2D values were not different between the two groups. We conclude that although 250HD level in hip fracture patients is low, there is no evidence of secondary hyperparathyroidism, suggesting that the low 250HD levels may be a secondary phenomenon in response to the fracture.
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Calcif. Tissue Int. · Oct 1988
Comparative StudyPeak trabecular vertebral density: a comparison of adolescent and adult females.
To determine when spinal bone density reaches its peak, the trabecular vertebral density was assessed, via quantitative computed tomography, among females from two age groups: (1) adolescents (aged 14-19 years; N = 24); and (2) young adults (aged 25-35 years; n =24). The adolescent girls had a higher mean trabecular vertebral density (P less than 0.01), suggesting that spinal density reaches its peak around the time of cessation of longitudinal growth and epiphyseal closure.
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Calcif. Tissue Int. · Aug 1987
Comparative StudyCalcium, vitamin D-endocrine system, and parathyroid hormone in black and white males.
The serum and urinary calcium, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and parathyroid hormone (PTH) were studied in healthy black and white males living in Belgium, and the results were compared to data in blacks of similar age living in Zaïre. Dietary calcium and vitamin D were estimated in a sub-sample of blacks and whites examined in Belgium. Compared to whites (9.51 +/- 0.28 mg%) serum calcium was somewhat lower in blacks (9.26 +/- 0.27 mg% in Belgium; 9.19 +/- 0.48 mg% in Zaïre). ⋯ The serum levels of 1,25(OH)2D3 and human vitamin D-binding protein were similar in the three groups of subjects. Dietary calcium averaged 541 +/- 152 mg/day in blacks and was significantly (P less than 0.001) less than in whites (1,203 +/- 508 mg/day), whereas no significant difference was observed in dietary vitamin D intake between blacks and whites. It is concluded that calcium intake is low in blacks but stimulation of parathyroid hormone and 1,25(OH)2D3 required to achieve normocalcemia does not occur.
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Calcif. Tissue Int. · Jul 1987
Comparative StudyEffects of vitamin D3, 25-hydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 on parathyroid hormone secretion.
The active vitamin D metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] causes marked suppression of both pre-proparathyroid hormone messenger RNA (pre-proPTH mRNA) and parathyroid hormone (PTH) secretion. These effects are dose dependent and reversible when tested in an in vitro primary tissue culture cell system using normal bovine parathyroid cells. In the current studies, the precursors of 1,25(OH)2D3 and the related metabolite 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], were used in the same culture system to test for possible regulatory effects. ⋯ On the other hand, 24,25(OH)2D3 produced significant suppression of both pre-proPTH mRNA (77% of control, P less than .01) and PTH secretion (75% of control, P less than .005) at 10(-7) M. By comparison, 10(-11) M 1,25(OH)2D3 produced levels of suppression (25-30%) of both pre-proPTH mRNA and PTH secretion comparable to 10(-7) M 24,25(OH)2D3, while even greater suppression (40-50%) occurred at 10(-9)-10(-7) M 1,25(OH)2D3. From these studies, we conclude that vitamin D3 and 25(OH)D3 do not have significant effects on PTH synthesis and secretion over the range of doses tested.(ABSTRACT TRUNCATED AT 250 WORDS)
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Calcif. Tissue Int. · Feb 1986
Comparative StudyAcute antiosteoclastic effect of salmon calcitonin in osteoporotic women.
Twenty-one women with primary osteoporosis received an intramuscular injection of 100 IU of salmon calcitonin at 8 AM. Blood samples IU of salmon calcitonin at 8 AM. Blood samples were collected up to 5 h postcalcitonin and urine was collected for 24 h in three periods of 8 h each. ⋯ In absolute values the fall of THP excretion was significantly greater in the pagetic patients but the percentage diminution was not significantly different in osteoporotic women and in pagetic patients. Salmon calcitonin induced a significant acute diminution of bone turnover in patients with osteoporosis, as defined by decreases in total urinary hydroxyproline. The calcitonin-induced hypocalcemia does not seem to be an accurate index of the hormone action in osteoporosis.