RESUMO
A study was made of the influence of low and high calcium intakes at two feeding levels (experiments 1 and 2), and of different magnesium intakes (experiment 3) during the dry period, on the cellular resorptive activity in bone of dairy cows at parturition. In experiment 1 (26 cows) the feed intake was 1.12 times maintenance and the calcium intake was either 13.0 g d-1 or 83.5 g d-1. In experiment 2 (33 cows) the feed intake was 1.9 times maintenance and the calcium intake was either 26.4 g d-1 or 87.2 g d-1. In experiment 3 the cows feed intake was 1.4 times maintenance, the calcium intake was 71 to 72 g d-1 and the magnesium intake was either 16.6 g d-1 or 71.0 g d-1. Bone biopsies were taken from the tuber coxae between three and eight hours after parturition. In experiment 1 the cellular resorptive activity in bone from older cows was higher in the cows receiving the low calcium diet. In experiment 2 the differences between the bone resorptive activities of the two groups were small. In experiment 3 the bone resorptive activity was lower in the cows with a deficient supply of magnesium. There were significant relationships in young cows, but not in older cows, between the cellular resorptive activity in bone and the rate of calcium mobilisation measured biochemically. These results suggest that in older dairy cows bone resorption makes only a minor contribution to the total rate of calcium mobilisation at parturition and is therefore of minor importance for the prevention of periparturient hypocalcaemia.
Assuntos
Reabsorção Óssea/efeitos dos fármacos , Cálcio da Dieta/farmacologia , Bovinos/metabolismo , Trabalho de Parto/metabolismo , Magnésio/farmacologia , Animais , Feminino , Ossos Pélvicos/análise , GravidezRESUMO
Bone mineral content (BMC) and bone mineral density (BMD) of the spine (L2-L4) and hip (at femoral neck, Ward's triangle, and greater trochanter sites) were determined by dual-photon absorptiometry (DPA), and of the radius by single-photon absorptiometry (SPA) in healthy postmenopausal women aged 40-70 years. The relationships of BMC and BMD to years since menopause were examined separately in 97 women who were above 115% of ideal body weight (IBW) and in 128 women below. The heavier women had significantly greater mean BMC and BMD at each site than did the normal-weight women. In the normal-weight women, there was a significant negative correlation between BMD and years since menopause at each measurement site except the greater trochanter. In the obese women, BMD decreased with increasing years since menopause at the radius site only and BMC declined with increasing years after menopause at the hip (femoral neck and Ward's triangle region) as well as the radius. Thus, body size is a significant determinant of BMD in this population. The pattern of loss of BMD from Ward's triangle and femoral neck regions of hip are similar to that of the spine. The BMC and BMD findings in the hip suggest that remodeling occurs at this weight-bearing site which has a favorable effect on bone strength.
Assuntos
Peso Corporal , Menopausa/fisiologia , Obesidade/patologia , Ossos Pélvicos/patologia , Rádio (Anatomia)/patologia , Coluna Vertebral/patologia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Minerais/análise , Obesidade/metabolismo , Ossos Pélvicos/análise , Rádio (Anatomia)/análise , Coluna Vertebral/análiseRESUMO
Los Alamos National Laboratory has analyzed autopsy tissue for the USTR, as a part of its study of the uptake, distribution and retention of Pu and other transuranic elements in occupationally exposed workers since 1978. In April 1979, Los Alamos received the internal organs and bone samples from the first whole-body donation to the USTR. The donor was known to have an internal deposition of 241Am. All soft tissue, the bones from the right half of the skeleton, and the odd-numbered vertebrae were received at Los Alamos in February 1980. The bones were subdivided along anatomical areas of interest. All soft tissues and bone specimens were analyzed for their 241Am content. A total deposition of 147.4 nCi 241Am was measured. Approximately 18% of the 241Am remaining in the body (disregarding that in the left hand), was found in the soft tissues, and 82% was in the bones and teeth. The soft tissues and organs containing the largest amounts of 241Am were the combined soft tissue (striated muscle, connective tissue and skin) 8.8%; liver, 6.4% and respiratory tract, 1.5%. The remaining organs accounted for 0.9% of the systemic burden.
Assuntos
Amerício/análise , Osso e Ossos/análise , Amerício/efeitos adversos , Amerício/metabolismo , Autopsia , Tecido Conjuntivo/análise , Humanos , Fígado/análise , Masculino , Matemática , Melanoma/análise , Pessoa de Meia-Idade , Músculos/análise , Neoplasias Induzidas por Radiação/análise , Ossos Pélvicos/análise , Plutônio/análise , Sistema Respiratório/análise , Pele/análise , Crânio/análise , Distribuição TecidualRESUMO
Roentgenograms of an Egyptian mummy, dating from 1500 B.C., showed extensive calcification of the intervertebral discs and articular narrowing in both hip and knee joints. Biopsy cores from the right hip showed parallel black zones in the region of the articular surfaces, leading to a clinical diagnosis of ochrinosis. The black pigment was extracted, analyzed, and compared to an air-oxidized homogentistic acid polymer. The two substances apparently were identical. The chemical evidence thus confirms the clinical finding of ochronosis, an autosomal recessive disorder. This is, so far as known, the earliest verified case of this disorder.
Assuntos
Ácido Homogentísico/análise , Múmias , Ocronose/história , Paleopatologia , Cartilagem/análise , História Antiga , Ocronose/diagnóstico por imagem , Ossos Pélvicos/análise , RadiografiaAssuntos
Osso e Ossos/análise , Fluoretos/análise , Biópsia , Doenças Ósseas/metabolismo , Fluoretos/uso terapêutico , Humanos , Hiperparatireoidismo/metabolismo , Cálculos Renais/metabolismo , Falência Renal Crônica/metabolismo , Análise de Ativação de Nêutrons , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Ossos Pélvicos/análise , Uremia/metabolismoRESUMO
To evaluation the uniformity of the degree of mineralization in the skeleton the bone phosphorus/hydroxyproline ratio (bone P/Hypro) was determined in different localizations of ten human skeletons. Marked differences in bone P/Hypro were found between cortical bone and spongy bone. No difference was found between cortical bone from humerus, femur and cranium. But the mean value of these cortical bones was significantly higher than the mean value of the studied spongy bones. No significant correlation was found between the two bone types. Differences in bone P/Hypro were also found between different spongy bones. In pelvis the value did not differ between four spongy bone localizations but the mean value was significantly lower than for the other spongy bones (thoracal column, lumbal column and clavicle). Between these other spongy bones no difference was found in mean bone P/Hypro, and the mean of the pelvic bone localizations correlated significantly to the other spongy bones. The study demonstrates differences in the chemical composition of the human skeleton. A value of bone P/Hypro in the iliac crest can be used to estimation of bone P/Hypro in other spongy bones but not in cortical bones.