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Biomedical subjects

R Salama

Publications and source records attributed to R Salama.

At least 19 recordsLinked to original sources
PubMed1997

The metabolism of vitamin D3 in response to testosterone.

Sex steroids were suggested as regulators of vitamin D metabolism. While considerable data is available regarding interaction between estradiol and vitamin D, very little is known about interactions between testosterone and vitamin D. A similar gap exists with regard to the involvement of the vitamin D endocrine system in the pathogenesis of the female versus the male osteoporosis syndrome. In the present study we studied the effect of long-term treatment with testosterone on the metabolism of vitamin D in vitamin D3 replete sexually immature male chicks. We were able to show under this treatment, circulating levels of 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) are significantly reduced, but intestine and bone concentrations are significantly increased. The increased concentration of 1,25(OH)2D3 in bone was accompanied by an increase in the ash content of this tissue. The reduction in serum 1,25(OH)2D3 was not dependent on reduced activity of the renal 25-hydroxy vitamin D3 - alpha - hydroxylase. Based on these findings it is proposed that testosterone is involved in the stimulation of the biological response to vitamin D in the classical target-organs, such as intestine and bone, and this observation may provide partial explanation to the pathogenesis of osteoporosis in hypogonadal men.

Animals↗
PubMed1993

The release of cytotoxic drugs from acrylic bone cement.

The ability of cis-platinum, 5-fluorouracil, and methotrexate to leach out from various types of bone cements was examined in three different experimental systems: (1) in vitro release in physiological solution; (2) in vitro release in the presence of mouse fibrosarcoma cells; and (3) in vivo release in rabbits. The amount of drugs released was measured either spectrophotometrically by atomic absorption or by using tritium-labeled drugs. In vitro cement pellets were found to release these drugs slowly for up to six months; release was greater in the first few days, rapidly declining with time. Up to 6% of the methotrexate implanted leached out during the entire experiment. The figures for cis-platinum and 5-fluorouracil were much less: 3.3% and 3.4%, respectively. Palacos bone cement had the best leaching properties. The drugs leached out were also effective in reducing the numbers of viable mouse fibrosarcoma cells in tissue culture. In vivo, high levels of the drugs were recovered from blood drained from the operative wound of the rabbits, while very low levels of these drugs were found in the serum. Anticancer drug-loaded cement may be used effectively in the treatment of pathologic fractures and tumor surgery. This delivery method may reduce the side effects that result from systemic administration of such drugs.

Animals↗
PubMed1990

Natural history of impacted subcapital femoral fractures and its relevance to treatment options.

A study of 123 patients with impacted, subcapital femoral fractures was undertaken to determine the natural history of this injury. It was found that the angle of the fracture, the degree of valgus and the degree of retroversion were without significant effect on the incidence of subsequent disimpaction. Age was important, with a 20 per cent incidence of disimpaction in patients over the age of 68 years. In patients younger than this the incidence was only 2 per cent. These results indicate that conservative treatment may be appropriate for some younger patients, but the advantages of this approach must be compared with the medical, social and economic benefits of early mobilization that the relatively simple operative procedure permits.

Age Factors↗
PubMed1987

Residual adduction of the forefoot. A review of the Turco procedure for congenital club foot.

Forty-four feet in 28 children previously treated by a one-stage posteromedial release operation (the Turco procedure) were reviewed clinically and radiologically to determine the cause of residual adduction of the forefoot. In 21 clinically adducted feet (48%) the main cause of residual deformity was metatarsus varus alone or metatarsus varus in spite of talonavicular overcorrection; in five feet the cause was talonavicular subluxation. There was no residual adduction in 23 feet (52%) but only 12 had normal radiographic measurements. In the remaining feet, various forms of spurious correction of metatarsus varus and talonavicular subluxation or both were seen, resulting in normal-looking feet. Recession of the origin of abductor hallucis and release of the short plantar muscles and fascia at the time of posteromedial release is recommended. The forefoot adduction was satisfactorily corrected in 91% of the feet subsequently operated on using this modified procedure.

Child↗
PubMed1983

The effect of vitamin D and its metabolites on fracture repair in chicks.

One-day-old chicks were depleted of vitamin D. At 3 weeks their right tibiae, and those of a control group given vitamin D3, were fractured and pinned. After fracture the controls were kept on vitamin D3. Another group was left vitamin D-deficient. The remaining depleted chicks, divided into four groups, were given vitamin D3, 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or a combination of 24,25(OH)2D3 and 1,25(OH)2D3. The callus obtained after 9 and 14 days was subjected to torsional stress. The callus of chicks given vitamin D continuously showed the greatest resistance, whereas that of vitamin D-deficient chicks showed the smallest resistance. Repletion with either vitamin D3 or its metabolites increased the strength of the callus. Repletion with the combination of 24,25(OH)2D3 and 1,25(OH)2D3 produced the most marked results, in that the callus was even stronger than that of chicks replete with vitamin D3. It is concluded that 24,25(OH)2D3 is essential for bone formation in addition to the known active vitamin D metabolite 1,25(OH)2D3, and the possible clinical implications of these findings are discussed.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Hip fractures in patients with Parkinson's syndrome.

Hip fractures in patients with Parkinson's syndrome present a continuing challenge to orthopaedic surgeons. Sixty-two consecutive such patients have been reviewed. With or without operation, there was very high rate of mortality (31%) and complications. However, the functional results, the ability to walk, progression of the disability, and the quality of life were significantly better after operation. The results suggest that operation is the preferable solution for these patients. They require, however, much more particular care than other patients with hip fractures. This includes adequate adjusted antiparkinson medication, appropriate anesthesia with special attention to adequate ventilation and postoperative analgesia, more intensive respiratory and functional physiotherapy, very meticulous nursing care, and a relatively extended period of preventive antibiotics.

Aged↗
PubMed1983

Xenogeneic bone grafting in humans.

The beneficial effect of a composite autologous red bone marrow and bone graft is well documented in experimental animals. In an attempt to improve the osteogenic potential of xenogeneic bone for clinical use, xenogeneic bone was combined with autologous red marrow and used in 110 bone grafting operations in 98 patients. Hydrogen peroxide-macerated (Kiel) bone was immersed in autologous red marrow obtained by iliac crest punctures. The results were excellent in conditions covering a wide range of indications for bone grafting. The results of treatment of pseudarthroses were most satisfactory. Deproteinized xenogeneic bone serves as a bank bone implant when impregnated with living autologous marrow or placed in a bed of bleeding cancellous bone.

Animals↗
PubMed1982

Osteoarthritis of the hip and fracture of the proximal end of the femur.

The purpose of this investigation was to verify a long-standing clinical observation that patients with fracture of the proximal end of the femur have less evidence of osteoarthritic changes in their hip joints than would have been expected in patients of similar age groups. The radiographs of 342 patients with fractures and those of 157 controls were examined. The statistical results gave uncontroversial evidence that the incidence of osteoarthritic joints was lower in the fracture group. The difference was even greater with severe osteoarthritic changes. This suggests that patients with osteoarthritis have a "better quality" of bone. They are less likely to be suffering from osteoporosis and less liable to fractures of the proximal end of the femur.

Age Factors↗
PubMed1981

The development of the normal infantile hip as expressed by radiological measurements.

Acetabular and centre edge angles were measured on normal radiographs of 164 children (328 hips) aged from three months to five years. Using regression and correlation analysis, mathematical formulae were derived which allow the calculation of the normal acetabular and centre edge angles for a given age. The relationship between age, acetabular angle and centre edge angle was studied.

Acetabulum↗
PubMed1980

Skeletal findings in human neutrolethyrism. Is there a human osteolathyrism?

In a review of the roentgenological files of 22 patients suffering from spastic paraplegia due to neurolathyrism, 3 patients were found to present abnormal skeletal findings. 2 patients showed absence of union of the secondary ossification centres of the iliac crests, the ischial tuberosities and the vertebral bodies. Their age at the time of ingestion of poisonous Lathyrus sativus plants was 19 and 20 years. The 3rd patient had bowing and thickening of his right femoral shaft. He was 22 years old at the time of poisoning. These findings which are similar to those found in experimental osteolathyrism have never been described in clinical neurolathyrism. They are of a nature to throw some doubt on the correctness of the currently prevailing concept of sharp distinction between these two pathological entities.

Bone Diseases↗