Computerized simulation of bone remodeling: graphic demonstration of dynamic processes.

A computerized simulation model has been developed to study the histologic patterns of dynamic remodeling processes in trabecular bone. The osteoid seam thickness and the distance between the tetracycline labels are calculated based on (partly hypothesized) parameter values, such as matrix appositional rate, mineralization rate, number and life span of the osteoclasts, resorption rate, and mineralization lag time. The results of a simulation run are demonstrated using computer graphics.

Clinical, biochemical and histological results of a double-blind trial with 1,25-dihydroxyvitamin D3, estradiol and placebo in post-menopausal osteoporosis.

Twenty-eight women with postmenopausal osteoporosis were studied in a double-blind trial aimed to compare the effects of a one-year treatment with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), estradiol valerate (E2) and placebo. Patients were divided into 4 groups: group 1 was given 1,25(OH)2D3 alone, group 2 was given E2 alone, group 3 was given 1,25(OH)2D3 + E2, group 4 received a placebo. The evaluation of the effects of the treatments included clinical examination of patients, the measurement of a number of biochemical parameters, such as plasma and urinary calcium and phosphate, urinary hydroxyproline, serum alkaline phosphatase, the measurement of intestinal calcium absorption and bone mineral content (BMC) and a histomorphometric study of bone biopsies from the iliac crest.

[Etidronic acid therapy in Paget's disease of bone].

Treatment of Paget's disease of bone was done in 32 patients using monotherapy with disodium etidronate (Diphos). A further 19 patients underwent combined treatment with etidronate and human calcitonin. Both monotherapy and combined treatment led to marked regression of disease activity in most patients as measured be decreased activity of alkaline phosphatase.

[Spondylosclerosis hemispherica. Roentgenmorphologic and histomorphologic contribution to this syndrome].

We have observed 87 cases of spondylosclerosis hemispherica. This lesion has a multiple aetiology, including bacterial causes (florid or low grade infections), stress due to scoliosis, ankylosing spondylitis, dorsal disc prolapse or diffuse disc degeneration. In the majority of cases it is possible to ascertain the aetiology from a consideration of the clinical and serological findings, together with ordinary radiography, conventional tomography or computed tomography.

[Spinal hemangioma in the roentgen picture of the Andersson lesion in ankylosing spondylitis].

The vertebral cavernous hemangioma is described as the number five cause in the etiology of the Andersson lesion (vertebral-discal destruction in ankylosing spondylitis). In one case of a completely stiffened spine, radiographs showed a vertebral hemangioma with a cockade-like appearance instead of the typical coarse-striated osseous structure. Histologic necropsy results were those of a cavernous vertebral hemangioma.

Morphological changes in osteosarcoma after chemotherapy--COSS 80.

Forty-five osteosarcomas were investigated by special methods such as preparation of undecalcified bone tumor tissue, imprint cytology, histochemistry, and quantitative analysis. The morphological regression grades and their relation to chemotherapy are reported by Salzer-Kuntschik et al. (1983).

Morphological grades of regression in osteosarcoma after polychemotherapy - study COSS 80.

The histologic grade of regression of 50 osteosarcomas after polychemotherapy - according to the protocol study, COSS 80 - was classified on a six-stage regression scale; 56% of all patients responded well to chemotherapy regression grades I, II, and III and no significant difference between BCD- and CPL-treated patients could be found. Tumors under 10 cm in length responded better to chemotherapy than those of greater length and there was a good correlation between the clinical estimation of tumor regression and progression and the histologic grade of regression.

[Osteopenia. A problem of long-term dialysis].

Hemodialysis induced osteopenia represents one of the serious late complications of long-term treatment with hemodialysis. The incidence of osteopenia in our hemodialysis-patients ranges between 5 and 10 percent (Atkinson et al. 1973; Delling et al.

[Renal osteodystrophy in children. Therapy with 1,25-dihydroxy-cholechalciferol (author's transl)].

Growth arrest and renal osteodystrophy are major problems in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy in 14 dialyzed children using 1,25-DHCC for 12 months. Values in plasma of Ca, P, Mg, alkaline phosphatase, iPTH, 25-OH-D, and 1,25-DHCC were determined regulary.

[Influence of vitamin D therapy on renal osteodystrophy in children (author's transl)].

Growth arrest and renal osteodystrophy is a major problem in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy by using vitamin D3 for 24 months. Values in plasma of Ca, Mg, alkaline phosphatase, iPTH, 25-OH-D were determined regularly.

The action of 1,25 (OH)2D3 on turnover kinetic, remodelling surfaces and structure of trabecular bone in chronic renal failure.

Fibroosteoclasia as well as osteoidosis are reduced by 1,25(OH)2D3 treatment if secondary hyperparathyroidism preexists. Fibrosteoclasia completely disappeared after 6 months therapy in some cases. 1,25(OH)2D3 has no or only a very slight effect on the disturbed mineralization in type II of renal bone disorder (osteoidosis only, no signs of secondary hyperparathyroidism).

Histomorphometric analysis of bone changes in surgically proven primary hyperparathyroidism and nephrolithiasis--the importance of bone biopsy in diagnosis.

The morphologic changes in trabecular bone were studied in 60 patients with surgically proven hyperparathyroidism and in 69 patients with nephrolithiasis. The hyperparathyroid bone lesions showed substantial variation in their extent. Four, typical stages were defined.

Shwachman's syndrome and leukaemia.

The clinical and morphological characteristics of Shwachman's syndrome (exocrine pancreatic insufficiency, pancytopenia, skeletal changes) were observed in a boy who, at the age of 8 years, developed a juvenile form of chronic myeloic leukemia which did not respond to cytostatic treatment. Autopsy revealed a striking lipomatous atrophy of the pancreas, defects in the ossification zones of the bones and marked dwarfism. In addition there was leukaemic infiltration of the pancreas, the spleen, the liver and the lymph nodes.

[Treatment of renal osteopathy with 5,6-trans-25-hydroxycholecalciferol (author's transl)].

The influence of 5,6-trans-25-hydroxycholecalciferol on renal osteopathy was investigated in a total of 132 patients in 26 dialysis centres. Various doses were used, the average being 4000-6000 IU/day. In 32 patients a daily dose of 6000-9000 IU was used.

[A rare case of so-called idiopathic osteolysis associated with a lymphangioma of the fibula (author's transl)].

In a 70-year old female patient, a so-called idiopathic massive osteolysis with destruction of the proximal right femur within six months, was observed. Histologically, the following conditions were found at the time of resection: a stroma rich in fibres, with the inclusion of blood vessels, as well as an osteoclastic absorption which was still clearly active at the margins, besides marginally defined processes of bone formation. A good functional result without progressing osteolysis at the femur was achieved via a total endoprosthetic replacement of the right hip joint.

[Reaction of articular cartilage to subchondral defect filling with autologous cancelous bone, Kiel's bone chips and bone cement].

Equally sized subchondral osseous defects were produced in 30 adult rabbits. The defects were filled with autologous cancellous bone, bone cement, or macerated heterologous cancellous bone. Twelve weeks later those filled with autologous cancellous bone showed consolidation with preservation of the subchondral border line.

Renal bone disorders in children: therapy with vitamin D3 or 1,25-dihydroxycholecalciferol.

Twelve children with chronic renal failure (CRF) and sixteen children receiving regular dialysis therapy (RDT) were treated with between 10,000 and 50,000 IU of vitamin D daily. This was associated with an increase in serum calcium levels and reduction in PTH levels. In the children with CRF, secondary hyperparathyroidism was improved with treatment but its development was not completely prevented nor was healing complete.