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Biomedical subjects

T Holmström

Publications and source records attributed to T Holmström.

At least 37 records · Page 2Linked to original sources
PubMed1990

Benign osteoblastoma of the mandible.

Benign osteoblastoma is a rare osteoblastic tumour with osteoid and bone deposition. A rapidly growing osteoblastoma involving the area of the mandibular first and second molar of a 20-year-old female is described. Investigation of the collagenous components of the tumour by immunofluorescence was suggestive of a normal collagen synthesis by the tumour osteoblasts. The lesion is discussed with particular emphasis on its differential diagnosis and matrix constituents.

Adult↗
PubMed1990

Ten years' experience in patients with osteogenic sarcoma in Finland.

Ten years' results of 56 patients with high grade osteogenic sarcoma are reported. Fifty-two patients had M0 disease. Immediately after open biopsy the patients were treated with chemotherapy using modified Rosen's protocols T4, T7 and T10. The primary tumor was adequately removed in most patients. Six children were treated with limb saving. The actuarial and disease-free survival was 80% after 1 year, and 73% to 8 years. Two patients died because of toxic side effects of chemotherapy, one of septicemia, the other of late cardiac failure secondary to doxorubicin.

Actuarial Analysis↗
PubMed1990

The healing of contact Nd:YAG laser irradiated arterial wall. An experimental study in piglets.

The healing of an arterial lesion created by continuous wave contact Nd:YAG laser was investigated. Normal arterial walls were irradiated. It is nearly impossible to irradiate atheromatous plaques without involving adjacent normal arterial wall as well. The purpose of this study was to evaluate the healing process using a standard thermal laser. Different power outputs were used with 1.0 sec exposure. A cw Nd:YAG laser with a wavelength of 1064 nm was used. Eighteen piglets underwent laparotomy. An 0.6 mm fibre with a rounded 2.2 mm sapphire probe was introduced into the aorta and iliac arteries. The irradiation was performed vertically to the vessel wall. The artery specimens were studied histologically and through electron scanning microscopy. Immediately after irradiation, adherence of platelets was observed. At two days the core centre was invaded with mononuclear blood cells and polymorphonuclear leukocytes. At five days there was still some denudation of endothelium, and the initial debris started to disappear. At two weeks medial smooth muscle cells were seen around the necrotic zone. The area was encapsulated by layers of smooth muscle and collagen. The healing process seems similar to that of mechanical injury of the aortic intima.

Angioplasty, Balloon↗
PubMed1989

Tissue reactions around two alloplastic ligament substitute materials: experimental study on rats with carbon fibres and polypropylene.

The early connective tissue reactions around two alloplastic and prosthetic materials, carbon fibre and polypropylene were examined in 30 rats. Each of the materials was implanted into three sites: under the skin, intraperitoneally and into a femoral bone tunnel. Microscopic and scanning electron microscopic findings at 1, 3, 6, 9 and 12 wk post-operatively are described. The amount of granulation tissue around the carbon fibres was more prominent in all the environments, but the connective tissue remained less mature and less organized during the whole follow-up compared to that of the polypropylene. There was no ingrowth of bone between the bundles of the artificial materials in the bony tunnels. The differences in the early cellular reactions and scar tissue maturation in the interstices of these two materials are probably due to the structural differences rather than to the surface properties of the materials.

Animals↗
PubMed1989

Experiences of clodronate treatment of multifocal eosinophilic granuloma of bone.

Clodronate, an inhibitor of osteoclast function, reduces bone resorption in osteolytic metastases and in multiple myeloma. We have evaluated its ability to decrease bone destruction in patients with multifocal eosinophilic granuloma of the skeleton. Two patients, whose multifocal bone granulomas appeared with a frequency of about 6 months, received 1.6 g day-1 oral clodronate for 6 months. Both patients had a reduction in serum calcium level which was accompanied by a decline in the fasting urinary hydroxyproline/creatinine and calcium/creatinine ratios and a slight increase in parathyroid hormone (PTH) level. Pain relief was observed in both patients. No new bone lesions were seen during the treatment and the old lesions healed. After discontinuing the therapy, however, new painful lesions appeared after 5 years in patient 1 and after 3, 4 and 5 years in patient 2. We suppose that clodronate delayed the appearance of new granulomas.

Adult↗
PubMed1989

Allogeneic grafts for bone tumor. 21 cases of osteoarticular and segmental grafts.

We treated 21 aggressive and malignant bone tumors by wide resection and replacement with deep-frozen osteoarticular and segmental (intercalary and block) allografts. Radiologic and histologic studies showed a gradual accretion of new bone on the graft trabeculae, sometimes with total creeping substitution. Substantial resorption of grafted condylar bone occurred in 3 of 14 cases. One of them ended with arthrodesis; in the other 2 the result after augmentation autografts was fair. Radiographically, a gradual joint surface destruction was observed in all the osteoarticular grafts after 5 years, not correlating with joint function, however. Biopsies showed some cartilage regeneration. Each patient underwent, on an average, two operations. Function after osteoarticular grafts at 3-16 years was excellent in 1 case, good in 4, fair in 6, and poor in 1 case; 2 cases were too recent for evaluation. Function 3-12 years after segmental grafts was excellent in 3 cases and poor in 3 cases (1 amputation due to nonunion, 1 amputation due to recurrence, and 1 prosthetic replacement due to recurrence); 1 case was too recent for evaluation. We conclude that an allograft is an acceptable alternative in the reconstruction of large tumor defects. However, it still presents unsolved immunologic and preservation problems, which make the prognosis guarded.

Adolescent↗
PubMed1989

Vitamin D status and concentrations of serum vitamin D metabolites and osteocalcin in elderly patients with femoral neck fracture: a follow-up study.

Vitamin D status and the serum osteocalcin concentration in patients with femoral neck fractures were studied as follows. Thirty-seven elderly patients (P) with fracture of the femoral neck were studied, whereas 24 age-matched persons (C) seen at the out-patient department for non-orthopaedic reasons served as controls. The dietary intake of vitamin D, estimated using a vitamin D score based on food items known to be the main sources of vitamin D, was significantly lower in the patients than in the controls. There was no difference in the serum 25-hydroxy-vitamin D (25-OH-D) (P: 22.3 +/- 7.5 nmol/l; C: 27.5 +/- 13.5) or the serum 1,25-dihydroxy-vitamin D3 concentration (P: 86 +/- 43 pmol/l; 31) C: 85 +/- 31) between the groups. The 25-OH-D concentration was, however, low as compared to reference values, suggesting vitamin D deficiency in both groups. There was no difference in the serum osteocalcin concentration between the groups (P: 3.1 +/- 1.7 micrograms/l; C: 3.4 +/- 1.5). One year later the serum osteocalcin concentrations (5.9 +/- 2.2 micrograms/l, n = 11) was significantly higher (P less than 0.005) in the patients than at the time of the fracture (3.2 +/- 2.2 micrograms/l), indicating an active bone turnover in the patients still present 1 year after the fracture.

Aged↗
PubMed1988

Calcitonin and granulation tissue formation in the rat. An experimental study.

The effects of systemically administered calcitonin (CT) on granulation tissue development were compared using viscose cellulose sponges as wound model in the rat. The ingrowth of new granulation tissue was analyzed for the contents of various connective tissue components (total nitrogen, hydroxyproline, DNA, and RNA) and for the differential counts of the cells infiltrating the sponges. The results indicate that up to 4 weeks postoperatively (p.o.) CT did not affect the net amount of collagen, measured as hydroxyproline, total nitrogen, aminosugars nor the dynamics of differentiation and viability of the invading cells. The present observation that CT has negligible effects, if any, on the early stages of connective tissue formation and on the cell population indicates that surgical procedures could be carried out safely during systemic CT therapy without an increased risk of wound complications.

Animals↗
PubMed1988

No effect of growth hormone on recovery of load-protected bone. Cortical bone mass and strength studied in rabbits.

The effect of human growth hormone on the recovery of a previously atrophied diaphyseal bone, stress-shielded by plating, was studied in 56 adult rabbits using the contralateral tibia as a control. At removal of the plates, an initial 40 per cent reduction of torsional strength was seen. The strength was normalized in 3 weeks. A concomitant reduction of bone mineral density was normalized in 1.5 weeks. No difference in the rate of strength regeneration was found between growth hormone-treated rabbits and controls. In the treated rabbits an increase in cortical bone area due to subperiosteal new bone formation was seen in previously plated bones, as well as in sham-operated bones.

Animals↗
PubMed1988

Clodronate for osteolytic metastases due to breast cancer.

Breast-cancer patients with multiple osteolytic bone metastases were treated with clodronate (Cl2MDP) 1.6 g/day (17 patients) or placebo (17 patients) for 12 months. Bone pain, extension of bone metastases and formation of new osteolytic foci were reduced by Cl2MDP, and development of severe hypercalcaemia was prevented. After withdrawal of treatment, the patients were followed up for at least 12 months. New bone metastases developed in both groups. There were, however, less fractures and less hypercalcaemia in the Cl2MDP than in the placebo group. The survival rate was higher in the Cl2MDP group than in the placebo group. No side-effects were observed in the Cl2MDP group.

Aged↗
PubMed1987

Fracture repair during external fixation. Torsion tests of rabbit osteotomies.

Bone repair was studied in the rabbit tibiofibular bone after a midshaft transverse osteotomy stabilized by external fixation and heavy compression. Both subendosteal and subperiosteal callus formation with concomitant contact healing were observed within 3 weeks, and were further succeeded by subendosteal resorption and increased porosis resulting in atrophy of the cortical bone. Subjected to the torsion test, the bones exhibited restoration of strength within 3 weeks, with maximal energy absorption and elasticity at 6 weeks. The failure of the osteotomy in the torsion test, with radiographic visibility of the osteotomy, characterized the soft-tissue type of behavior of the bones. Hard-tissue like behaviour of the bones with resistance to torsion at the osteotomy site and radiographic obliteration of the osteotomy line occurred by 12 weeks, indicating complete union of the osteotomy. Our experiments demonstrate that elastic external fixation is preferable to the rigid compression plate.

Animals↗
PubMed1986

Osteosarcoma of the mandible: analysis of nine cases.

A total of 16 cases of mandibular osteosarcoma were diagnosed histologically in Finland and reported to the Finnish Cancer Registry between 1953 and 1983. Review of the histologic slides confirmed the diagnosis in only nine cases. The overall five-year survival rate was 44%. Three patients who were free of clinical disease at the end of the follow-up period (mean, 9.9 years) either had tumors of low-grade malignancy (two cases) or had undergone prompt radical surgery (one case). The importance of radiography in the diagnosis of mandibular osteosarcoma is stressed, because the widening of the periodontal membrane spaces, the sunray effect, and the widening of the mandibular canal are almost pathognomonic for osteosarcoma.

Adult↗
PubMed1986

Effect of compression on fracture healing. Plate fixation studied in rabbits.

Bilateral osteotomies in rabbit tibiae were secured with six-hole rigid plates, using axial compression on the right and no compression on the left side. Histological, histomorphometric and torsiometric analysis was performed up to 24 weeks postoperatively. Histological analysis showed end-to-end primary bone healing regardless of treatment. The fracture gaps tended to be smaller in the compression osteotomies, but union was achieved within the same time on both sides, and at 6 weeks torsiometric analysis of the paired specimens revealed similar mechanical properties. By the time the fracture had united both groups of bones showed similar degrees of subendosteal resorption. As a result of this porotic transformation the strength of the cortical bone was slightly impaired from 6 weeks onward, whether or not compression had been applied. The results suggest that axial compression does not augment fracture healing of plated cortical bone.

Animals↗
PubMed1985

Loss of bone strength after intramedullary nailing. Torsion tests of tibial osteotomies in rabbits.

Rigid intramedullary nailing was used in 75 rabbits to stabilize a transverse osteotomy of the midshaft of the tibia. In 36 additional rabbits intramedullary nailing was performed without osteotomy. No additional external immobilization was used postoperatively. After removal of the nail the mechanical strength of the tibiofibular bones was tested torsiometrically in 30 osteotomized and 18 non-osteotomized animals from 3 to 24 weeks after the operation. At 3 weeks the torsional load fractured all osteotomized bones through the osteotomy line. At later stages a spiral fracture occurred either crossing or close to the osteotomy area, usually distal to the tibiofibular junction. The increase in mechanical strength of the osteotomized bones reached a maximum at 6 weeks and then decreased. The strength of the non-osteotomized nailed bones also decreased slightly. The results suggest that rigid intramedullary nailing, although providing good conditions for early consolidation of experimental osteotomy, leads secondarily to deterioration of the mechanical properties of tubular bone.

Animals↗
PubMed1984

Long-term effects of dichloromethylene diphosphonate in patients with osteolytic bone metastases and coincident primary hyperparathyroidism.

Dichloromethylene diphosphonate (Cl2MDP), an inhibitor of osteoclast-mediated bone resorption, lowers serum calcium in hypercalcemia associated with malignancies and with primary hyperparathyroidism. We have evaluated the effectiveness of Cl2MDP in three patients who had multiple osteolytic bone metastases due to breast cancer and coincident primary hyperparathyroidism and who refused neck exploration. Cl2MDP was added to the tamoxifen treatment and was given orally at a dose of 1600 mg/day for 12 months. All patients had a reduction in serum calcium level which was accompanied by a decline in the fasting urinary calcium and hydroxyproline excretion. Administration of Cl2MDP was not associated with any changes in parathyroid hormone levels. New bone metastases were observed neither during the treatment nor in the follow-up period. No side effects were observed.

Aged↗