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Biomedical subjects

U Lindgren

Publications and source records attributed to U Lindgren.

At least 55 records · Page 3Linked to original sources

A new operation for hallux valgus.

A distal oblique osteotomy on the first metatarsal, with lateral displacement of the metatarsophalangeal joint and internal fixation with a compression screw, was performed. No splint or plaster was used. The operation is relatively simple and effective. Pain and discomfort during a short healing period are minimal. Forty-nine feet were operated on in 42 patients by eight surgeons. The patients were advised to bear full weight after six weeks. Return to unlimited work was possible after six weeks. The complications were superficial infection in one case and screws entering the metatarsophalangeal joint in two cases. One patient complained of metatarsalgia after the operation, but all other patients were satisfied after follow-up periods ranging from three months to six years.

Adolescent↗

Role of parathyroid hormone and 1,25-dihydroxyvitamin D3 in the development of osteopenia in oophorectomized rats.

The effect of ovarian insufficiency on calcium metabolism has been thought to involve an increased bone resorptive effect of parathyroid hormone and possible impaired synthesis of 1,25-dihydroxyvitamin D3. In the present study a rat model allowing for controlled serum levels of parathyroid hormone and 1,25-dihydroxyvitamin D3 was used. Oophorectomy in this species is associated with increased serum levels of 1,25-dihydroxyvitamin D3 and decreased bone mass. Although thyroparathyroidectomy increased bone mass, an increased sensitivity of bone to parathyroid hormone in oophorectomized rats was not observed. Thus the development of the osteopenia did not seem to be related to increased parathyroid hormone sensitivity or to reduced levels of 1,25-dihydroxyvitamin D3. Exogenous 1,25-dihydroxyvitamin D3 increased bone mass in oophorectomized as well as intact rats. Intestinal calcium transport was increased by moderate doses of 1,25-dihydroxyvitamin D3. Intestinal calcium transport was also reduced by thyroparathyroidectomy and increased by the administration of parathyroid extract. A tendency for increased accumulation of 1,25-dihydroxyvitamin D3 in blood in oophorectomized rats has been noted. It is suggested that the tendency to hypercalcemia in ovarian-insufficient females given 1-hydroxylated vitamin D compounds may be related to a diminished metabolism of 1,25-dihydroxyvitamin D3.

Animals↗

Screw fixation in bone of guinea pigs sensitized to nickel and cobalt.

A screw was inserted transversely through the distal femora and proximal tibiae of guinea pigs sensitized to either Ni or Co. An equal number of nonsensitized animals were treated in the same way. The animals with Ni allergy received an ASIF stainless steel screw and the animals with Co allergy a Howmedica Vitallium screw. After 6 weeks no obvious differences were observed in the histological picture around the femur screws that could be ascribed to metal sensitivity. The mechanical strength of the bone adjacent to the tibial screws was tested by measuring maximum torque during continuous tightening of the screws at a rate of 2 revolution/second. No significant differences in maximum torque resistance were found between sensitized and nonsensitized animals. The results indicate that sensitivity to Ni or Co does not compromise the mechanical fixation between metal and bone during the early period after the implantation.

Animals↗

Postoperative infections resulting from bacteremia. An experimental study in rabbits.

The possibility that postoperative infections can result from bacteremia in the early postoperative period was investigated in an animal model. Defects were made bilaterally in the proximal femora of rabbits. On one side the defects were filled with acrylic bone cement. The rabbits were infected with a suspension of Staphylococcus aureus either in the wound hematoma or by an intravenous route. The cement implant did not attract infection, as the infections became equally distributed both on the cemented and the uncemented side in the locally as well as in the intravenously inoculated group. The experiment also shows that if bacteria occur in the bloodstream in the early postoperative period, there is a high risk of the wound becoming infected.

Animals↗

The susceptibility of total joint replacement to hematogenous infection in the early postoperative period: an experimental study in the rabbit.

Postoperatively a suspension of Staphylococcus aureus was injected intravenously in rabbits with experimental total knee arthroplasties. Four weeks after the operation 70% of the total joint replacements were infected whereas a bacterial survey revealed ony occasional positive cultures from the kidneys. The infected joint prostheses were all loose, and histologic and microradiographic signs of loosening and infection were common in the surrounding tissues. The results illustrate the importance of preventing bacteremia in the early postoperative period of total joint arthroplasty.

Animals↗

Short-term effects of 1-alpha-hydroxy-vitamin D3 in patients on corticosteroid treatment and in patients with senile osteoporosis.

Six patients with bronchial asthma undergoing long-term corticosteroid treatment and six patients with senile osteoporosis were given the same oral dose of 1-alpha-hydroxy-vitamin D3 (1alpha-OH-D3) and calcium. The immediate effect on blood and urine chemistry and on the intestinal calcium absorption rate were studied. Hypercalcaemia occurred frequently among the patients treated with corticosteroids but not among those with senile osteoporosis. We conclude that corticosteroids do not counteract the effects of 1alpha-OH-D3. No correlation was found between the calcium absorption rate and the degree of osteoporosis, nor did the serum PTH levels show any differences that could be attributed to the treatment.

Administration, Oral↗

Prediction of spirometric values in patients with scoliosis.

The prediction of normal spirometric values requires a measure of the non-deformed body height of scoliotic patients. The arm-span method has been used for estimating the non-deformed body height in spite of the fact that opinions about the normal relationships between body height and arm span differ. In order to minimize the error of estimation of non-deformed body height, the normal relationships between body height and arm span were determined for 91 males and for 118 females of ordinary body stature, varying age (5-78 years), and Swedish origin. The body-height/arm-span relationships were described by linear regression equations taking age into account. The results indicate significant sex and age differences in the arm-span/height ratio. Multiple regression equations including arm span and age as regressors were used to calculate the non-deformed body height in scoliotic patients. The arm-span method was compared with the method using the degree of lateral curvature of the spine for calculation of non-deformed body height of scoliotic subjects. The arm-span method resulted in a correction of body height and predicted spirometric values that agreed closely with those obtained by the method using the degree of curvature of the spine. The two methods may be used alternatively. In accordance with earlier reports, the predicted spirometric values were underestimated when the measured body height was used.

Adolescent↗

Short-term effects of varying doses of 1 alpha-hydroxyvitamin D3 on blood and urine chemistry and calcium absorption of osteoporotic patients.

During a period of 4-7 days, synthetic 1 alpha-hydroxyvitamin D3 (1alpha-OH-D3) was given to osteoporotic patients with hip fractures in 3 different dose levels, viz. 1 microgram, 2 microgram, and 4 microgram, in combination with calcium. The increase in serum calcium level was more prominent during treatment with 2 microgram and 4 microgram doses of 1 alpha-OH-D3 and was also dependent on the duration of treatment. The level of serum phosphate was only slightly elevated. The urinary calcium excretion increased, while the urine phosphate and hydroxyproline excretion decreased. The intestinal absorption of calcium increased in rate during treatment with 1 alpha-OH-D3. On discontinuation of treatment, values did not normalize within 6 days. The administration of small doses of 1 alpha-OH-D3 did not seem to expose osteoporotic patients to the risks of hypercalcemia. The efficiency of vitamin D metabolites in the treatment of osteoporosis requires further investigation.

Aged↗

Interim report on treatment of osteoporotic patients with 1 alpha-hydroxyvitamin D3 and calcium.

Fifteen patients, 13 women and 2 men (mean age 60 years) with osteoporosis of different types have been under treatment with 1 alpha-hydroxyvitamin D3 and calcium. The responses were observed clinically and by the use of roentgen morphometry, photon absorptiometry and by blood and urine chemical analyses. The treatment had beneficial clinical effect in all but 3 patients. The intestinal calcium absorption rate increased significantly. Slight hypercalcemia and a significant hypercalciuria occurred during treatment. Serum and urine phosphate levels, alkaline phosphatase and parathyroid hormone values were within normal ranges. The bone mineral content increased significantly during treatment. 1 alpha-hydroxyvitamin D3 and calcium was well tolerated by the patients. Three patients had coincidental acute attacks of spinal pain and 2 had further vertebral crush fractures. A period of time longer than one year is necessary to further evaluate the effects of 1 alpha-hydroxyvitamin D3 therapy on the clinical course of severe osteoporosis.

Adult↗

The reversibility of disuse osteoporosis. Studies of bone density, bone formation, and cell proliferation in bone tissue.

One hind leg of 80 adult rats of the Sprague-Dawley strain was made osteoporotic by immobilization for 9 weeks. Osteoporosis was noted in both the femur and the tibia when the hydrated gross bone density and the bone surface areas were measured. No signs of reversibility were observed during 10 weeks after the period of immobilization. Tetracycline and DCAF labelling failed to show significant signs of increased bone formation during the 10 weeks after remobilization. At the moment of remobilization and for some weeks thereafter, there were signs of depressed mitotic activity in the bone cells when expressed as the 3H-thymidine/DNA ratio. The conclusion was that neither the cell-proliferation rate nor the cellular activity increases sufficiently for restitution of the disuse osteoporosis.

Animals↗

Effect of the Milwaukee brace on vital and ventilatory capacity of scoliotic patients.

The vital capacity (VC) and the maximal voluntary ventilation (MVV) were studied in 29 patients with scoliosis (predominantly idiopathic). The results obtained confirmed earlier observations that scoliotic patients have decreased VC and MVV. The immediate effect of the application of the Milwaukee brace was a slight though statistically significant decrease in MV, whereas there was no significant effect on VC. Treatment with the Milwaukee brace for a mean period of 15 months did not appreciably influence the VC or MVV, as a percentage of the predicted normal values of the patients, when measured without the brace applied.

Adolescent↗

Bacteria in hip surgery. A study of routine aerobic and anaerobic cultivation from skin and closed suction wound drains.

One hundred and seven patients with closed suction wound drains after hip surgery were investigated with regard to bacteria in the drain. In one-third of the cases bacterial contamination of the wound was found. In more than half the total number of cases the bacteria in the wound were not identical with those found on the skin, either pre- or post-operatively. Anaerobe bacteria occurred only in one case. Penicillin administration considerably reduced the frequency of positive cultures. These findings support the prophylactic use of antibiotics in the prevention of late infections in endoprosthesis operations even when the early infection rate is satisfactorily low.

Bacillus↗

The fine structure of the parathyroid glands of rats with disuse osteoporosis.

The parathyroid glands were studied ultrastructurally in two groups of rats: one control group and one group with an immobilized hindleg. The aim was to see whether immobilization has any effect on the fine structural appearance of the parathyroid glands. No morphological differences were recorded between the two groups. Nor were any signs of increased functional activity observed. The results denote that no increased parathyroid activity occurs after immobilization of an extremity in rats.

Animals↗