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Biomedical subjects

O Schaadt

Publications and source records attributed to O Schaadt.

13 recordsLinked to original sources
PubMed1990

Calcium absorption and bone mineral content in patients subjected to ileal bypass because of familial hypercholesterolaemia.

Calcium absorption and bone mineral content were studied prospectively in 30 patients with familial hypercholesterolaemia subjected to partial ileal bypass surgery. One-third of the patients were followed up for 10 years after the operation. Six months postoperatively calcium absorption decreased significantly, from a median of 16% to 13%. The effect persisted up to 5 years of follow-up study. Ten years after the operation the absorption of calcium (median, 14.5%) was not significantly different from the preoperative calcium absorption (median, 16%). Bone mineral content, measured in 76% of the patients, was retained in all patients studied. A significant correlation was present between calcium absorption and urinary calcium. The reduction in calcium absorption did not correlate with increases in faecal fat. Other long-term side effects were persistent diarrhoea and moderate steatorrhoea. A significant weight loss was slowly regained in most patients. An increase of renal oxalate excretion was only small and transient in most patients. The study shows that bypass of the terminal 200 cm of ileum for familial hypercholesterolaemia causes moderate diarrhoea and steatorrhoea in most patients but only a slight reduction of intestinal calcium absorption and apparently no risk of bone demineralization. A benefit of a postoperative calcium and vitamin D supply cannot be excluded.

Adult↗
PubMed1989

Vitamin D, parathyroid hormone, and bone mineral content of lumbar spine and femur in primary biliary cirrhosis.

In order to elucidate the pathogenesis and degree of osteopoenia in primary biliary cirrhosis (PBC) we conducted a cross-sectional study of 47 non-selected female patients with biopsy-proven PBC. Bone mineral content (BMC) of the lumbar spine, femoral neck and femoral shaft was determined using dual photon absorptiometry. Compared to healthy females of corresponding decades the PBC patients exhibited significantly decreased mean BMC-values in lumbar spine (88%, P less than 0.05) and femoral neck (92%, P less than 0.05) but not in femoral shaft (96%, NS). Bone mineral content was not significantly associated with duration of liver disease, impairment of liver function (serum concentrations of albumin, clotting factors II + VII + X, bilirubin, alkaline phosphatase galactose elimination capacity or histology), variables reflecting calcium homeostasis (serum concentrations of ionized calcium, parathyroid hormone, vitamin D binding protein, 25-hydroxy vitamin D3 and 1,25-dihydroxy vitamin D3) or previous treatment with glucocorticosteroids. In view of our negative findings we suggest that future studies in this field should focus on physical activity and female sex hormones as determinants for the prevention of osteopoenia in females with primary biliary cirrhosis.

Adult↗
PubMed1988

Different trends of age-related diminution of bone mineral content in the lumbar spine, femoral neck, and femoral shaft in women.

The bone mineral content (BMC) was measured by dual photon absorptiometry of 153Gd simultaneously in the lumbar spine, femoral neck, and femoral shaft in a cross-sectional study of 113 healthy women aged 20-89 years. The measurements suggest differences in the patterns of bone mineral decrease at the three sites of the skeleton in relation to age. The lumbar spine BMC decreases mainly during the usual time of menopause, whereas BMC decreases linearly in the femoral neck from young adulthood to old age. The femoral shaft BMC is nearly unaltered until the seventh decade, and thereafter BMC declines significantly. In each of the three age groups selected according to the usual time for menopause there was significant correlations between BMC of the scanning sites and nearly identical variance of BMC with age, suggesting homogeneity in the female population with regard to rate of bone diminution.

Adult↗
PubMed1988

Bone mineral content of the lumbar spine and lower extremities years after spinal cord lesion.

Bone mineral content (BMC) was measured by dual photon absorptiometry in the lumbar spine, femoral neck and shaft, and proximal tibia in 26 individuals with spinal cord lesions sustained 2 to 25 years previously. In average BMC of the lumbar spine was within the range of normal values. BMC of the femoral neck and shaft was in average 25% lower than the normal values, and for the proximal tibia more than 50% lower than the normal value. Participants with cervical lesions had lower BMC values in the femoral bones than those with thoracic lesions. Neither presence of spasticity nor daily use of long leg braces influenced the BMC significantly. Participants with previous lower extremity fractures had lower BMC values in the long bones compared with participants without fractures. The preservation of the BMC of the lumbar spine may be due to maintenance of load on the spine while sitting in a wheelchair.

Adolescent↗
PubMed1987

Mineral content of upper tibia assessed by dual photon densitometry.

Bone mineral content (BMC, g/cm) and bone mineral density (BMD, g/cm2) of the proximal tibia were determined by dual photon absorptiometry (DPA). Measurements just distal to the subchondral plates of the tibia condyles, where the bone structure is predominantly trabecular, proved to give the most consistent results. The precision of BMC measurements in this region, expressed as the coefficient of variation, was 1.1 per cent and of BMD measurements 2.5 per cent. In a cross-sectional study on 63 normal women and men, BMC and BMD showed a decrease with age at a rate of about 8 and 9 per cent per decade, respectively, in women, but not in men. In normal women, BMC of proximal tibia was correlated with BMC of lumbar spine, femoral neck, and femoral shaft, as well as with body weight and height. DPA may be useful in the study of bone reactions, such as in patients undergoing arthroplasty of the knee.

Adolescent↗
PubMed1985

Bone mineral content of the femoral neck and shaft: relation between cortical and trabecular bone.

Bone mineral content (BMC) of the femoral neck and shaft was determined with dual photon absorptiometry, using 153Gd. Comparison of BMC with the amount of hydroxyapatite (HA) of in vitro specimen showed correlation coefficients of 0.992 and 0.996 for the femoral neck and shaft respectively. In the femoral neck the amount of cortical bone in a bone section varies from 16% ash weight in the proximal part to 71% in the distal part. Corresponding to the site of BMC measurements, the cortical bone constitutes 57% in the femoral neck and 95% in the femoral shaft. The precision error of measurements of BMC in vivo, expressed as the coefficient of variation for repeated determinations, was 1.4% for the femoral neck and 1.3% for the femoral shaft. In the femoral neck it is possible to distinguish between structures consisting mainly of cortical bone and structures containing mostly trabecular bone. While the cortical bone value decreases only slowly with age in normal women, corresponding to BMC of the femoral shaft, the trabecular bone value decreases rapidly even compared with BMC of the femoral neck. Despite the significant correlation between the values for cortical and trabecular bone a distinction seems essential from a clinical point of view.

Adult↗
PubMedDate not supplied

The degree of bone mineralization in chronic renal failure estimated from phosphorus/hydroxyproline ratio in bone biopsies.

The degree of bone mineralization is the proportion between the contents of mineral and collagen in bone. As phosphorus (P) and hydroxyproline (Hypro) constitute a constant fraction of bone mineral and collagen, respectively, the P/Hypro ratio in bone tissue provides an estimate of the degree of mineralization. The P/Hydro ratio has been studied in bone biopsies from 42 patients with severe chronic renal failure. A few of them had a subnormal P/Hypro ratio and these patients corresponded to the diagnosis of classical osteomalacia or probably hyperparathyroidism. However, the mean bone P/Hypro ratio was significantly higher than normal, indicating a general tendency towards a higher degree of bone mineralization in patients with chronic renal failure.

Adult↗