Adynamic bone lesion has been defined as low bone turnover, normal or low osteoid volume and decreased bone formation rate (BFR). A prospective cross-sectional study was performed in 16 asymptomatic post-transplant kidney patients with normal renal function, to evaluate low bone mineral density. The mean age of the nine women and seven men was 33.9 +/- 7.3 years, the mean serum creatinine was 1.1 +/- 0.2 mg/dl and the mean creatinine clearance 71.5 +/- 13.8 ml/min/1.73 m2. Six patients received triple immunosuppressive therapy for a period of 10.3 +/- 3.7 months and nine received double therapy. Eighty-four months after renal grafting, we carried out bone densitometry, biochemical markers and bone biopsy. Bone densitometry showed 78 +/- 8.7% and 80.4 +/- 8% for hip and lumbar spine, with a mean Z score of 1.79 +/- 0.72 and 1.88 +/- 0.78 (SD), significantly less than normal in the Hispanic young population for those two regions. Serum PTH (0.83 +/- 0.23 microgram/ml normal range 0.32-0.65), urine cAMP (4.1 +/- 1.3, normal range 0.5-4.7 nmol/mg Cr) and total and nephrogenic fraction (3.1 +/- 1.1, normal range 0.29-2.9 nmol/100 ml GFR) were significantly greater than normal (P < 0.01). The bone biopsy in 12/16 patients showed decreased percentage osteoid area (1.59 +/- 0.86% vs 3.19 +/- 0.82%), percentage mineralized area (13 +/- 4.7% vs 21.03 +/- 3.36%) and bone formation rate (505 +/- 237 vs 1275 +/- 168 microns2/mm2/day), with a P value < 0.05 compared with 10 normal bone biopsies. The remaining four patients exhibited low bone turnover image with normal bone formation rate (1442 +/- 206 microns2/mm2/ day). Iron deposits were demonstrated at the mineralization front in 10/16 patients. No aluminium or amyloid deposits were observed. The histomorphometric results showed the presence of adynamic bone lesion in 12 renal transplant recipients with normal renal function and osteopenia, which explains the low bone density. The long-term use of glucocorticoids and the presence of iron deposits may contribute to this bone lesion. The biochemical markers of bone remodelling showed abnormalities compatible with moderate increase in parathyroid function. The adynamic lesion in the presence of hyperparathyroid function may suggest down-regulation of PTH bone receptors, alterations of the bone microenvironment or both.

Hypocitraturia and hypomagnesuria were the most frequent risk factors associated with urolithiasis, followed by hypercalciuria. High PTH values were excluded. Children presented two or more risk factors for urolithiasis.

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Parturient paresis and subclinical hypocalcemia are frequent metabolic disorders in dairy cows postpartum. The aim of this study was to determine the effect of postpartum partial milking in the first two milkings on blood serum calcium concentration in dairy cows. Twenty multiparous Holstein dairy cows were randomized into two groups. Cows of group 1 (n = 10) were partially milked at the first and second milking postpartum. Cows of group 2 (n = 10) were completely milked. Blood samples were collected from all animals 5-7 days before calving, within 30 min after calving, and 4, 8, 12, 16, 20, 24, 28, and 32 h after calving for determination of serum calcium (Ca), phosphorus (P), and magnesium (Mg) concentrations. Colostrum production was registered and sampled in the first and second milking. Concentration of Ca in colostrum was determined by atomic absorption spectrophotometry. Serum Ca and P concentrations decreased in both groups after parturition (P < 0.05) and remained low during 32 h postpartum with no difference observed between groups (P > 0.05). Serum concentrations of Mg were stable in all samples and no statistical difference was observed between groups (P > 0.05). Colostrum production was higher in completely milked cows only in the first postpartum milking (P < 0.05), but there was no difference between groups at the second milking. Total Ca secretion in colostrum was higher in the complete milking group at the first and second postpartum milking. Colostrum Ca secretion increased at the second milking with respect to the first one in both groups (P < 0.05). There was no correlation between serum Ca and colostrum Ca (P > 0.05). In this study, the partial milking of colostrum in the first and second milking postpartum did not prevent subclinical hypocalcemia in dairy cows.