Human peripheral blood monocytes have high affinity binding sites for 1,25-(OH)2D3 (Kd 0.14 nM, sedimentation coefficient 3.7S). Resting human peripheral blood T lymphocytes, however, do not have a demonstrable 1,25-(OH)2D3 receptor. After activation with phytohemagglutinin the T cells exhibit the receptor within 24 h, and this expression is blocked by cycloheximide. The receptor in activated T lymphocytes has a sedimentation coefficient of 3.7S and a high affinity (Kd 0.10 nM) for the ligand.

In patients who have never previously received bisphosphonate therapy, the intravenous administration of 4-amino-1-hydroxybuthilidene-1,1-bisphosphonate (AHButBP), 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (AHPrBP), or 6-amino-1-hydroxyhexylidene-1,1-bisphosphonate (AHHexBP) induced an acute-phase response (APR) irrespective of the underlying disease, manifested by a fall in circulating lymphocyte number and serum zinc concentration and in a rise in C-reactive protein (CRP); a febrile reaction occurred in 30% of the patients. The APR was maximally expressed within 28-36 hours of i.v. administration of the bisphosphonates and disappeared 2-3 days later despite continuous treatment. These effects were dose dependent and the lowest doses necessary for an APR were 10 mg of AHButBP and AHPrBP and 75 mg of AHHexBP. Doses up to 1,000 mg/day i.v. of dichloromethanebisphosphonate (Cl2MBP) were devoid of these side effects. In patients treated with either a single i.v. dose of amino-bisphosphonates which resulted in an APR or with a suboptimal dose, a subsequent challenge 12-160 days later of the high dose failed to cause a rise in CRP or a fall in the lymphocyte count. The desensitization to AHButBP or AHPrBP was also seen following pretreatment with Cl2MBP. These findings suggest that bisphosphonates interact with macrophage-like cells resident in the skeleton and stimulate interleukin-1 release which is responsible for the appearance of the APR. At the same time, however, the bisphosphonates render these cells insensitive to further stimulation for several months.(ABSTRACT TRUNCATED AT 250 WORDS)

Peak bone mass is an important determinant of the risk of osteoporotic fracture, and preventive strategies against osteoporosis require a clear understanding of the factors influencing bone gain in early life. We report a longitudinal study aiming to identify the relationships between childhood growth, lifestyle, and peak bone mass in women. One hundred and fifty-three women born in a British city during 1968-1969 were traced and studied in 1990. Data on their growth in childhood was obtained from linked birth and school health records; current bone mineral measurements were made by dual X-ray absorptiometry. There were statistically significant associations between weight at 1 year and BMC (but not BMD) at the lumbar spine (r = 0.32, p < 0.01) and femoral neck (r = 0.26, p < 0.01). These remained significant after adjusting for current weight. There were also strong relationships between childhood height measurements and adult BMC at the two skeletal sites. Physical activity was the major lifestyle determinant of BMD after allowing for body build. We conclude that infant growth and physical activity in childhood are important determinants of peak bone mass in women. Growth primarily determines the size of the skeletal envelope, and its trajectory is established by age 1 year. Activity, in contrast, modulates the mineral density within the skeletal envelope and may contribute to the consolidation of bone following the end of linear growth.

Clinically apparent vertebral deformities are associated with reduced survival. The majority of subjects with radiographic vertebral deformity do not, however, come to medical attention. The aim of this study was to determine the association between radiographic vertebral deformity and subsequent mortality. The subjects who took part in the analysis were recruited for participation in a multicentre population-based survey of vertebral osteoporosis in Europe. Men and women aged 50 years and over were invited to attend for an interviewer-administered questionnaire and lateral spinal radiographs. Radiographs were evaluated morphometrically and vertebral deformity defined according to established criteria. The participants have been followed by annual postal questionnaire--the European Prospective Osteoporosis Study (EPOS). Information concerning the vital status of participants was available from 6480 subjects, aged 50-79 years, from 14 of the participating centres. One hundred and eighty-nine deaths (56 women and 133 men) occurred during a total of 14,380 person-years of follow-up (median 2.3 years). In women, after age adjustment, there was a modest excess mortality in those with, compared with those without, vertebral deformity: rate ratio (RR) = 1.9 (95% confidence interval (CI) 1.0,3.4). In men, the excess risk was smaller and non-significant RR = 1.3 (95% CI 0.9,2.0). After further adjusting for smoking, alcohol consumption, previous hip fracture, general health, body mass index and steroid use, the excess risk was reduced and non-significant in both sexes: women, RR = 1.6 (95% CI 0.9,3.0); men RR = 1.2 (95% CI 0.7,1.8). Radiographic vertebral deformity is associated with a modest excess mortality, particularly in women. Part of this excess can be explained by an association with other adverse health and lifestyle factors linked to mortality.