The effect of 1,25 (OH)2D3 on bone mineralization: ultrastructural studies in patients with renal osteodystrophy

The acute effects (15-50 days) of 1,25(OH)2D3 (0.5-2 microgram/day) on the histological, fluorescence-microscopical and ultrastructural appearance of mineralizing osteoid in iliac crest spongiosa were studied in 6 uremic patients on maintenance hemodialysis. While there was a marked decrease on endosteal fibrosis and osteoclast counts, volumetric and surface densities of osteoid continued to stay elevated during the observation period. The number of osteoid seams with tetracycline double label increased in 4/6 patients but no such seams appeared in 2 patients who had shown only nonlabeled seams with diffuse staining of osteoid prior to therapy. In studies with transmission electron microscopy, the interface between non-mineralized osteoid and mineralized bone was irregularly outlined and broad. In contrast to normals, coarse mineral deposits were widely scattered in the nonmineralized osteoid. The mineral deposits had two different appearances, presumable depending on the plane of section relative to the direction of collagen fiber bundles: patches of microcristalline deposits encircling perpendicularly cut non-mineralized collagen bundles and needle- or plate-shaped crystals following the striation pattern of collagen fibers. The findings point to close interaction between the pattern of mineral deposition and collagen texture. The latter was highly irregular (woven) in all uremic patients. Mineral deposits were in part normal and in part highly abnormal in texture, the latter particularly in sites with irregular collagen texture. Upon therapy, no consistent change of the ultrastructure of the mineralizing osteoid/bone interface was observed by transmission or scanning and electron microscopy.

Bronchopneumonia disguising lung metastases of a painless central chondrosarcoma of pubis

Chondrosarcoma is a generally locally malignant chondroid-forming bone tumor with a low potential for distant metastases. A small and completely painless central chondrosarcoma of pubis metastasizing to the lungs in a 63-year-old woman with bronchopneumonia is reported. Here we emphasize the mimicry and low growth of the chondrosarcoma and the easiness with which the diagnosis in completely asymptomatic patients can be missed. Although painless chondrosarcoma metastasizing to lung is rather rare, this tumor should be always included in the differential diagnosis of malignancies in this age category.

[Acardius or "twin-reversed arterial prefusion" sequence. Report of four cases and review of current therapeutic possibilities]

We describe four cases of acardius (one of hemiacardius, two of holoacardius acephalus, and one of the holacardius amorphus) and present the current range of therapeutic possibilities: control of amniotic fluid by repeated amniocentesis or indomethacin therapy, administration of digoxin to the mother, selective preterm delivery of the acardiac twin by hysterotomy, interruption of the anastomoses by injection of thrombogenic coils, sclerosing agents, umbilical cord ligation, fetoscopic laser coagulation, and thermocoagulation.

Association between histomorphometry and biochemical markers of bone turnover in a longitudinal rat model of parathyroid hormone-related peptide (PTHrP)-mediated tumor osteolysis

Advanced tumor osteopathy is characterized by abnormal bone turnover. Using a rat model of parathyroid hormone-related peptide (PTHrP)-mediated tumor osteolysis, the aim of the present study was to define the sequential changes in, and the association between, biochemical and histomorphometric indices of bone metabolism during the early stages of developing tumor osteopathy. Eight-month-old Wistar rats (n = 48) were subcutaneously inoculated with either 2 x 10(6) cells of the Walker carcinosarcoma 256, or saline on day 0, and treated with either saline or the bisphosphonate ibandronate until killing on day 8. Serum calcium (sCa), alkaline phosphatase (sTAP), and osteocalcin (sOC) and urinary calcium (uCa), deoxypyridinoline (uDPD), and pyridinoline (uPYD) were measured daily. In a second semilongitudinal experiment (n = 70), the number of osteoclasts and osteoblasts (N.Oc, N.Ob), trabecular bone volume (BV/TV), and osteoid volume (O.Ar) were assessed by histomorphometry. In untreated tumor-bearing animals, osteoclast numbers increased by 74% on day 3 (5.4 +/- 2.4 vs. 3.1 +/- 1.5/mm(2), p < 0.05), and trabecular bone volume fell by 24% on day 4 (12.5 +/- 2.0 vs. 15.8 +/- 1.2%, p < 0.05). Both time course and magnitude of these changes were closely reflected by an increase in uDPD (0.46 +/- 0.14 vs. 0. 31 +/- 0.15 nmol/12 h, p < 0.05) and uPYD on day 4 (1.44 +/- 0.25 vs. 1.03 +/- 0.3 nmol/12 h, p < 0.05), sCa (3.8 +/- 0.52 vs. 3.0 +/- 0. 13 mmol/L, p < 0.01), and uCa (0.13 +/- 0.08 vs. 0.03 +/- 0.01 mmol/12 h, p < 0.001) on day 6, and sTAP (254 +/- 127 vs. 120 +/- 40 U/L, p < 0.001) on day 7 (mean +/- SD), whereas sOC remained unchanged until day 8. When combining the results of the two experiments, a high correlation was found between the number of osteoclasts and the urinary excretion of PYD (r = 0.91) and DPD (r = 0.89). Treatment with ibandronate delayed hypercalcemia, abolished hypercalciuria, and accelerated bone resorption. We conclude that osteoclast activation is an early event in PTHrP-mediated osteolysis, which is closely reflected by the renal excretion of pyridinium cross-links of type I collagen. Therefore, specific biochemical markers of collagen breakdown may be useful as early indicators of developing tumor osteopathy.

Age-related changes in insulin-like growth factor I and II in human femoral cortical bone: lack of correlation with bone mass

The concentration of insulin-like growth factor-I (IGF-I) in human cortical bone declines with age, but the relevance of this decline for cortical bone turnover and bone mass is unknown. In the present study, we simultaneously assessed the concentration of IGF-I and -II in cortical bone matrix and histomorphometric parameters of bone mass and bone turnover in 125 samples from the proximal human femur shaft. Bone width decreased by 27% and porosity increased by 100% in female cortical bone between the fourth and the ninth decade. Similar, but weaker, changes tended to occur in male cortical bone. The concentrations of both IGF species were correlated with the percentage of osteons undergoing bone remodeling. However, despite age-related decreases in both IGF species in men and in IGF-I in women, neither of the IGFs accounted for age-related or age-independent variability in cortical porosity or bone width. In conclusion, these data suggest that the local concentrations of IGF-I and -II are related to cortical bone turnover. In contrast, our study provides no evidence for a major role of bone matrix IGF-I and -II as determinants of cortical bone mass in elderly individuals. Whether other components of the IGF system may be stronger determinants of cortical bone loss remains to be determined.

[Resting cartilage and the growth plate in dystrophic dysplasia: case report and clinicopathologic characteristics as compared to pseudodystrophic dysplasia and type II atelosteogenesis]

The authors describe the histopathology of the resting cartilage and the growth plate in a case of diastrophic dysplasia and review the differential diagnosis with pseudo-diastrophic dysplasia and atelosteogenesis type II.

Concentration of insulin-like growth factor (IGF)-I and -II in iliac crest bone matrix from pre- and postmenopausal women: relationship to age, menopause, bone turnover, bone volume, and circulating IGFs

Insulin-like growth factor-I (IGF-I) and -II are important local regulators of bone metabolism, but their role as determinants of human bone mass is still unclear. In the present study, we analyzed the concentration of IGF-I and -II in the bone matrix of 533 human biopsies from the iliac crest that were obtained during surgery for early breast cancer. There was an inverse association of bone matrix IGF-I concentration with age that was unaffected by menopause. Bone matrix IGF-I was positively associated with histomorphometric and biochemical parameters of bone formation and bone resorption and with cancellous bone volume. Based on the estimates of the linear regression analysis, women with a bone matrix IGF-I concentration 2 SD above the mean had a 20% higher bone volume than women with a bone matrix IGF-I concentration 2 SD below the mean. In contrast, serum IGF-I was neither correlated with bone turnover nor with bone volume and was only weakly associated with bone matrix IGF-I when adjusted for the serum concentration of IGF binding protein-3. Bone matrix IGF-II was positively associated with the osteoblast surface, but in contrast to IGF-I, tended to be positively associated with age and was unrelated to cancellous bone volume. In summary, our study suggests the following. 1) The concentration of IGF-I in cancellous bone undergoes age-related decreases that are similar to those of circulating IGF-I. 2) Menopause has no effect on this age-related decline. 3) Physiological differences in bone matrix IGF-I are associated with differences in iliac crest cancellous bone volume. 4) Bone matrix IGF-I is a better predictor of cancellous bone volume than circulating IGF-I. 5) The role of IGF-II in human bone tissue is clearly distinct from that of IGF-I.

Concentration of transforming growth factor beta in human bone tissue: relationship to age, menopause, bone turnover, and bone volume

Transforming growth factor beta (TGF-beta) is thought to play an important role in bone metabolism, but its relationship to human bone turnover and bone mass has not been examined yet. In this study, we measured the concentration of TGF-beta in 811 samples of male and female bone from four representative sites of the human skeleton and in the supernatants of 72 short-term human bone marrow cultures from the iliac crest. The concentrations of TGF-beta1 and TGF-beta2 in the bone matrix were positively correlated with histomorphometric indices of bone resorption and bone formation and with serum levels of osteocalcin and bone-specific alkaline phosphatase. We also observed a positive association between the release of TGF-beta in the bone marrow cultures and serum osteocalcin. Changes in the rate of cancellous or cortical bone remodeling with age or menopause were accompanied by corresponding changes in skeletal TGF-beta. In contrast, there was no significant relationship between the concentration of TGF-beta and bone volume at any skeletal site. In conclusion, our study supports the hypothesis that TGF-beta plays an important role in human bone remodeling, but fails to demonstrate an association between the skeletal concentration of TGF-beta and human bone mass.

Results of iliac crest biopsies taken from 1465 patients with primary breast cancer

This study was performed to analyze the relevance of iliac crest biopsy in patients with primary breast cancer with regard to metastases of the primary tumor and osteogenic disease. We performed intraoperative bilateral biopsy of the anterior iliac crests in 1465 patients with primary breast cancer. The bone specimens were histologically evaluated with regard to quality of the biopsy, tumor involvement, and osteogenic and hematogenic disease. Accurate and clear evaluation of the iliac crest biopsies was possible in 1365 patients (93%). Osteopenia was diagnosed in 48 patients (3.5%); 24 patients (1.7%) showed histological evidence of tumor involvement of the skeletal system. All these 24 patients received systemic (adjuvant) therapy after surgery. Ten patients had micrometastases, although in 5 of them both the postoperative bone scan and X-rays showed no pathological results. In 10 women with histologically negative bone biopsies, metastases to the bone were diagnosed by bone scan and radiological methods. Random perioperative iliac bone biopsy cannot be recommended in patients with primary breast cancer. Iliac crest biopsy is relevant in certain scenarios (e.g. suspected recurrence, doubtful bone scan).

In vitro and in vivo effects of tetrakisphosphonates on bone resorption, tumor osteolysis, ectopic calcification, and macrophages

The biological effects of bisphosphonates in calcium-related disorders are attributed to the incorporation of the bisphosphonates in bone, enabling direct interaction with osteoclasts and/or osteoblasts. The high accumulation of bisphosphonates in bone, due to their high affinity to hydroxyapatite (HAP), is essential for mediating in vitro and in vivo activity. In this study we examined the activity of tetrakisphosphonates, molecules containing two P-C-P type bisphosphonate moieties connected by a carbon chain. The novel compounds were examined in a battery of in vitro and in vivo models including HAP formation and dissolution, ectopic calcification, bone resorption, tumor osteolysis, and of macrophage-like cells (anti- or pro-inflammatory properties). The inhibition of ectopic calcification was ranked as follows: geminal bisphosphonates > bisacylphosphonates > tetrakisphosphonates. Pamidronate, but not the tetrakisphosphonates, was an effective antiosteolytic agent. Neither DNTP (tetrasodium 1,9-dihydroxynonane 1,1,9,9-tetrakisphosphonate) nor the bisacylphosphonate, PiBP (pimeloylbisphosphonate) seem to possess strong macrophage suppressive or inductive effects and can be considered to be relatively inactive in terms of anti- or pro-inflammatory action. A significant anticalcification effect was caused by various phosphonates, such as the tetrakisphosphonates, but DNTP, a tetrakisphosphonate, was found toxic as it impeded somatic growth and bone development.

[Pathogenesis of bone metastasis and tumor osteopathies]

The development of bone metastases is a selective process in which the hematogenous dissemination of tumor cells into the bone marrow does not play a decisive role. In addition to the peculiarities of blood flow within the marrow sinuses, leading to an accumulation of circulating tumor cells, host organ specific factors (adhesion molecules, chemotactic signals, cytokines and growth factors) are pathogenetically involved. These factors are liberated from the bone matrix by osteoclasts, which are activated by a variety of osteotropic tumor factors. Thereby a tumor osteopathy develops, which by osteolytic bone destruction and tumor-enhanced remodelling may cause bone pain, pathological fractures and hypercalcemia of malignancy. So far only the late stage of macrometastases and the concomitant osteopathy can be diagnosed. Using immunocytological methods, tumor cells can now be detected in bone marrow aspirates during the early subclinical stage of tumor cell shedding. Tumor cell-positive bone marrow aspirates in general mean a worsening of the prognosis and may in breast cancer indicate those patients who are threatened by the development of bone metastases.

[Tumor-associated hypophosphatemic osteomalacia: case report and literature review]

Despite the great number of neoplastic entities, which are able to cause this disease, "oncogenous osteomalacia" is hardly known as a paraneoplastic phenomenon. Without removing the not constantly malignant tumor as the underlying cause recovery is not possible. Until now pathogenesis is unknown. Together with a review of the literature a case report is presented, in which a malignant fibrous histiocytoma of soft tissue caused an untreatable osteomalacia. Because of failure of local tumor control prognosis in this case must be considered fatal.

[Tumor simulating manifestations of renal osteopathy: differential diagnosis and follow-up clinical examples]

The course of renal osteodystrophy possibly includes changes, which can mistakenly considered malignant. Especially dialysis-associated tumoral calcinosis may mislead to an inadequate aggressive surgical procedure. Spontaneous involution of these lesions takes place after subtotal parathyroidectomy. Brown tumors subsequent secondary hyperparathyroidism are extremely rare. During maintenance hemodialysis frequently appearing intraosseous cysts develop secondary to beta-2-microglobulin-amyloidosis. Surgery only should be performed in case of occurring pathologic fractures. Other cases are treated conservatively under continuous nephrologic supervision.

Prophylactic treatment of skeletal metastases, tumor-induced osteolysis, and hypercalcemia in rats with the bisphosphonate Cl2MBP

BACKGROUND

The purpose of this study was to investigate the influence of a prophylactic bone protective treatment with the bisphosphonate dichloromethane/diphosphonic acid (Cl2MBP) in an experimental model of osteolysis with intraosseous implantation of the Walker carcinosarcoma 256 B.

METHODS

The biphosphonate was given as a high-dose, short-term treatment (30 mg/5 days sc) followed by a treatment-free interval (1-7 weeks) or as a low-dose, long-term prophylactic treatment (2.5 or 5.0 mg/day/3 weeks sc). Osteolysis was measured with a radiographic and histologic grading system.

RESULTS

The high-dose short-term prophylactic treatment was shown clearly to inhibit tumor osteolysis. The osteoprotective effect decreases with increasing length of the treatment-free interval. A similar positive result could be achieved following the low-dose long-term prophylactic treatment. Dosage could not be shown to influence the inhibition of tumor osteolysis in the long-term bone protective treatment. A possible direct influence of the treatment on tumor growth could be ruled out. The prophylactic treatment does not inhibit body weight increase. Animals treated prophylactically showed less weight loss than the controls after tumor implantation.

CONCLUSIONS

These results show that a prophylactic treatment with Cl2MBPs protects the skeleton effectively against tumor osteolysis.

24R,25-dihydroxyvitamin D3 prevents aluminum-induced alteration of brain gangliosides in uremic rats by keeping the metal within perivascular astrocytes of the blood-brain barrier

The administration of aluminum (Al) to uremic rats leads to Al accumulation in different brain regions with subsequent alteration of brain gangliosides. Addition of 24R,25-dihydroxyvitamin D3[24R,25-(OH)2D3] did not influence the brain Al content determined by plasma argon emission spectrometry, but prevented the decrease in brain gangliosides. By using electron microscopy and laser microprobe mass analysis, it was demonstrated that in rats given 24R,25-(OH)2D3 together with Al, the metal was mainly kept within perivascular astrocytes of the blood-brain barrier. On the contrary, in rats given Al only, the metal was evenly distributed throughout the brain areas causing extensive demyelination, chromatolysis of nerve cells in some brain regions (hippocampus) and brain edema. Our results could find application in the prevention of Al-induced encephalopathy in patients on hemodialysis.

[Sonography in therapy-oriented diagnosis and after-care of primary bone and soft tissue tumors]

Based on the results of 150 patients with primary tumors or the suspicion of malignant lesions of the locomotor system the perspectives and limits of the sonographic diagnosis under the therapeutic aspects of interdisciplinary oncologic cooperation is demonstrated. As the ideal adjunct to conventional roentgenograms, ultrasound is the first-line imaging procedure in the fields of primary diagnosis, follow-up, post-therapeutic care as well as tumor exclusion for methodic, patient-related and economic/logistic reasons. Its consequent application will markedly reduce the number of more invasive and expensive methods.

[The prognostic significance of tumor cell detection in bone marrow of patients with breast cancer]

In 95% of patients with primary breast cancer, the extent of metastases cannot be proven by conventional methods. Nevertheless, more than 50% of these patients have a relapse within five years. To improve the predictive value for recurrency, we examined bone marrow aspirates of 128 patients with primary breast cancer. Bone marrow aspirates from 2-6 sites of the skeleton (iliac crest and sternum) were taken as well as biopsies for histological examination. The immunohistochemical studies were carried out on interphase smears and stained with cytoceratin antibodies (PKK 1) and antibodies against tumor-specific antigen TAG 12 (12 H 12). All patients were screened for distant metastases (X-ray, ultrasound, bone scan). Tumor cells and micrometastases in bone marrow were detected in 41 patients (32%). Their presence was correlated to other prognostic factors (tumor size, lymph node status, oestrogen/progesterone receptors). The median duration of follow-up was 39.5 months. 14 patients (45%) in the tumor cell positive group relapsed, compared to only 4 out of 36 patients in the tumor cell negative group. In 29% we found bone metastases. The relapse free interval was shorter for patients with micrometastases (8 vs. 15.8 months). The presence of tumor cells in bone marrow aspirates detected at the time of primary surgery, is a useful prognostic factor and a good predictor of metastases and may help in selecting patients for systemic adjuvant treatment.

Anticancer-agent-linked phosphonates with antiosteolytic and antineoplastic properties: a promising perspective in the treatment of bone-related malignancies?

Bisphosphonates are compounds with a high affinity for bone and other calcified tissues. They inhibit tumor-induced bone destruction and the associated hypercalcemia by hindering the activity of the osteoclasts. Owing to a long biological half-life of bisphosphonates in the bone, a treatment using a prophylactic regimen seems possible. This paper summarizes preclinical studies with the bisphosphonate 3-amino-1-hydroxypropylidene-1,1-diphosphonic acid and two methyl derivatives; 3-N,N-dimethylamino-1-hydroxypropylidene-1,1-diphosphonic acid and 4-N,N-dimetyhlamino-1-hydroxybutylidene-1,1-diphosphonic acid with respect to their bone-protecting activity in therapy as well as in prophylaxis. To find substances that are useful for the treatment of primary tumor, as well as bone metastasis, we synthesized and tested cis-diammine[nitrilotris(methylphosphonato)(2-)-O1,N1]platin um(II) and cis-diammine[( bis-(phosphonatomethyl)amino]acetato(2-)-O1,N1)platinum(II), which contain both an osteotropic and an antineoplastic moiety. Experiments were carried out: (a) in the intratibial transplanted Walker carcinosarcoma 256B of the rat, which mimics osteolytic bone metastasis, and (b) in the transplantable osteosarcoma of the rat, which shows a histology and metastatic pattern similar to that found in man. These investigations indicate that it is possible to effect adjuvant therapy of bone metastases by combination of two compounds with different properties into one structure without losing the therapeutic characteristics of the parent compounds. They thus provide evidence that it may be possible to design compounds well suited for the therapeutic or prophylactic treatment of bone-related malignancies.

Effects of parathyroidectomy on tissue calcium, phosphorus, magnesium, and copper concentrations in aluminum-loaded uremic rats

Rats were subjected to a two-stage 5/6 nephrectomy and treated with Al for 2 and 4 wk with a cumulative dose of 4.2 and 8.4 mg of Al, respectively. Other animals were parathyrectomized (PTx) and loaded with 8.4 mg of Al for 4 wk. Total Al, Ca, P, Mg, and Cu contents were analyzed in the liver, kidney, and bone by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results showed that Al given to growing uremic rats significantly increased the content of Al in the liver, kidney, and bone. Moreover, Al treatment increased the liver and kidney Ca levels and decreased the Ca and P values in bone. Previous parathyroidectomy significantly reduced Al accumulation within organs and changes in the Ca and P levels in the bone, liver, and kidney. The result was not influenced by different degrees of renal failure.

The influence of early parathyroidectomy on aluminum-induced rickets in growing uremic rats

Rats were subjected to a two-stage 5/6 nephrectomy and treated with aluminum for 2 and 4 weeks with a cumulative dose of 4.2 and 8.4 mg of aluminum, respectively. Other animals were parathyroidectomized and loaded with 8.4 mg of aluminum for 4 weeks. Histomorphometry and electron microscopy (tibiae), aluminum tissue (bone, kidney, liver) determination, serum (Ca, Mg, Zn, P, urea, creatinine, alkaline phosphatase, 1,25(OH)2D3, PTH) and urine (creatinine, A1) revealed that: (a) a dose of 8.4 mg aluminum was sufficient to induce rickets within 4 weeks of treatment and was associated with decreased serum calcitriol values and high aluminum accumulation within organs (electron-dense material was found in osteoblasts only); (b) previous parathyroidectomy prevented the occurrence of any aluminum-induced alteration of bone. It was associated with higher calcitriol and phosphorus values than in corresponding non-parathyroidectomized rats and significantly reduced aluminum accumulation within organs. The results was influenced neither by a drop in serum calcium values nor by different degrees of renal failure. We suggest that aluminum-induced rickets in growing uremic rats is prevented or delayed when previous parathyroidectomy has been performed.

Iliac crest needle biopsy as a method for determining estrogen receptors in bone metastases from breast cancer

The purpose of our study was to clarify whether the amount of tissue extracted by means of iliac crest needle biopsy (ICNB) would suffice for a quantitative determination of estrogen receptors (ER) in bone metastases, and to see if the method currently used for determining ER in primary tumors could also be successfully utilized in ICNB. 22 of 31 breast cancer patients examined could be evaluated. ER was positive in 7 (31.8%). Reasonable data are to be expected when the biopsy weight exceeds 0.1 g. Our study confirms that the necessary amount of tissue for ER analysis can indeed be extracted by ICNB. Our results justify further studies on a larger group of patients, since we cannot make conclusive statements concerning the value of this method for predicting the ultimate success of an endocrine treatment.

Value of bilateral iliac crest needle biopsy for pretherapeutic tumor staging of bronchogenic carcinomas

Two hundred and forty-three patients with lung cancer were biopsied pretherapeutically and bilaterally on the anterior iliac crest. Tumor infiltration into the bone marrow could be demonstrated in 7 patients. No tumor-positive biopsies were found in the 163 patients with non-small cell lung cancer (NSCLC). In small cell lung cancer (SCLC), however, the infiltration rate was 9% (7/80). In 3 of the 7 patients (43%) only 1 of the 2 sides biopsied had been infiltrated. All 7 patients with tumor-positive bone marrow samples were found to have additional metastases elsewhere (stage IV, 7/26; 27%). Therefore, according to our results, we cannot recommend iliac crest biopsy as a routine pretherapeutic procedure to aid in the staging of SCLC and NSCLC.

The effects of aluminium on brain gangliosides in uraemic rats treated with 24R,25-dihydroxyvitamin D3

The administration of aluminium to uraemic rats leads to aluminium accumulation in different brain regions. Aluminium intoxication significantly alters brain gangliosides, the content of which is increased in uraemic animals. This phenomenon can be prevented by administration of 24R,25-dihydroxyvitamin D3 (24,25(OH)2D3). Our results could possibly find an application in the prevention of aluminium-induced encephalopathy in patients on haemodialysis.

Talc granulomatosis in the rat: the relationship between osteoblast insufficiency and adjacent bone marrow hyperplasia

Bone loss in talc granulomatosis is paralleled by hyperplasia of bone marrow in the rat. To test the hypothetical relation between those two phenomena, bone matrix osteoinduction was employed as a model in which bone formation and bone marrow appearance are separated in time. Implantation of demineralized bone matrix to normal rats was followed by three talc injections (one weekly), starting 1 week after matrix implantation. Implants of demineralized bone and [3H]thymidine-labeled tibial metaphyses from talc-injected and normal rats were analyzed histologically and evaluated for alkaline and tartrate-resistant acid phosphatase activity on days 7, 14, 21, and 30 after matrix implantation. Analysis of tibial autoradiographs showed a marked growth arrest and bone marrow hyperplasia in talc-injected rats 7 days after first talc injection. Alkaline phosphatase activity in homogenates of bone implants was low in talc-injected rats on day 14 after implantation. Moreover, histology of the bone implants showed numerical and functional inhibition of osteoblasts on the same day, causing marked growth delay. Bone marrow appeared as late as day 21 after bone matrix implantation. We conclude that hyperplasia of the adjacent bone marrow is not the cause of bone loss in talc granulomatosis, but rather its compensatory consequence.

Cellular basis of inflammation-induced osteopenia in growing rats

Local nonosseous inflammation provoked by four subcutaneous talc powder injections induced a marked trabecular bone loss in rats within 7 days. The disturbance included suppression of bone elongation, inefficiency and decreased number of trabecular osteoblasts, decreased osteoprogenitor cell number in tibial metaphyses, and bone marrow expansion. Neither the appearance and function of osteoblasts in the vicinity of the cortical bone nor the number of osteoclasts in the metaphysis were found to be altered. The loss of trabecular bone in granulomatosis was based on a suppression of bone elongation and a failure of osteoblasts to form normal secondary spongiosa.

The value of bone marrow examination for tumor staging in breast cancer

The purpose of our study was to investigate the value of cytokeratin antibodies for identifying bone marrow involvement in breast cancer patients who showed no evidence of distant metastases using noninvasive tumor staging procedures. Bone marrow for histological (biopsy) and immunocytochemical (aspiration) evaluation was obtained from the anterior iliac crest from 50 unselected consecutive women during surgical treatment of the primary tumor. The histological examination was done on nondecalcified bone sections. The immunocytochemical studies were carried out on interface smears of the bone marrow aspirates. For staining, cytokeratin antibodies (PKK 1) and the immune alkaline phosphatase method was used. Cytokeratin-positive cells were found in 4 of the 50 cases (8%). Of those 4 patients, however, 2 also showed evidence of neoplastic bone marrow infiltration histologically. We thus were able to prove that immunocytochemistry on aspirates is superior to conventional histology in identifying tumor in bone marrow. Nonetheless, our results clearly fell below the rate found in previous studies where epithelial membrane antigen antibodies were used.

Protective effects of a prophylactic treatment with the bisphosphonate 3-amino-1-hydroxypropane-1,1-bisphosphonic acid on the development of tumor osteopathies in the rat: experimental studies with the Walker carcinosarcoma 256

The present report primarily describes protective effects of a long-term prophylactic treatment with 3-amino-1-hydroxypropane-1,1-bisphosphonic acid (APD) on the development of tumor-induced osteolytic bone destructions. Pretreatment with daily intravenous doses of APD 9.5 mg/kg for 1 week resulted in a significant reduction of Walker carcinosarcoma 256-induced bone destruction, when Walker cells were transplanted intraosseously (2 x 10(6) tumor cells/rat) 7 weeks later. Shorter pretreatment periods (4, 2 or 1 week prior to tumor inocculation) resulted in a nearly total inhibition of bone destruction as well as tumor-induced hypercalcemia. Tumor growth itself was not inhibited by APD pretreatment. Histological and microradiographical findings are reported. Consistent to our experiments and with regard to new immunocytological methods to detect single metastatic tumor cells in the bone marrow, potential risk groups may be defined which may profit from the prophylactic APD treatment to inhibit tumor-induced bone destructions.

Effects of 1 alpha,25- and 24R,25-dihydroxyvitamin D3 on aluminum-induced rickets in growing uremic rats

Rats were subjected to a two-stage subtotal nephrectomy or sham operation, and treated with aluminum (Al) or both aluminum and vitamin D3 metabolites for 5 weeks with a cumulative dose of 13.6 mg aluminum. Animals were injected with 3H-thymidine and 3H-proline. The following analyses were performed: quantitative histology of tibial metaphyses and cytomorphometric electron microscopy of osteoclasts, quantitative (ICP-spectroscopy) and qualitative determination (histochemical staining) of aluminum within organs, and serum biochemistry (Ca, P, Mg, vitamin D3 metabolites, alkaline phosphatase, urea). The following new facts of the aluminum-related bone disease became evident: (a) Application of aluminum to growing uremic rats induced rickets, whose major epiphyseal growth plate changes were 1 alpha,25(OH)2D3-dependent. Addition of 1 alpha,25(OH)2D3 prevented the formation of rachitic metaphysis, but failed to prevent osteoid accumulation on epiphyseal and metaphyseal trabecular surfaces. Moreover, calcitriol produced hyperosteoidosis and osteosclerosis in the same rats. Aluminum did not alter the function of osteoblasts, while osteoclasts seemed inactivated. (b) The development of rickets was associated with suppressed serum levels of 1,25(OH)2D3, reduced phosphorus level and the high content of aluminum in the bone, kidney, and liver. The addition of 24R,25(OH)2D3 markedly exaggerated the reduction of serum levels of calcitriol. We suggested that aluminum induces rickets in growing uremic rats, which consists of two components: vitamin D refractory osteomalacia and 1 alpha,25(OH)2D3-dependent epiphyseal growth plate changes.

The influence of 1 alpha,25- and 24(R),25-dihydroxyvitamin D3 on bone constituents during early mineralization in the rat

The influence of vitamin D metabolites on intramuscular implants of bone matrix in rachitic rats was investigated. Recipient rats with rickets were injected daily with 1 alpha,25(OH)2D3,24(R),25(OH)2D3 or a combination of both metabolites. The presence of 1 alpha,25(OH)2D3 increased significantly the alkaline phosphatase activity, and slightly increased the activity of acid phosphatase. 24(R),25(OH)2D3 had no effect on the activity of the measured enzymes. The results of inductively coupled plasma emission spectrometric determination of bone elements revealed that: (a) 1 alpha,25(OH)2D3 stimulated the incorporation of magnesium and decreased the phosphorus content of bone implants when compared with rats given both vitamin D metabolites; (b) 1 alpha,25(OH)2D3 as well as 24(R),25(OH)2D3 had antagonistic effects on bone carbonate content. The values for 1 alpha,25(OH)2D3 treated animals were significantly higher, and 24(R),25(OH)2D3 treated rats had a significantly lower carbonate content of implants when compared to the controls. Time-dependent CO2-liberation diagrams indicated a differently bound bone carbonate in 1 alpha,25(OH)2D3 treated rats; (c) when plotted against time, the diagrams for both the values for zinc and the activity distribution of the measured enzymes had a similar appearance, indicating zinc incorporation into bone enzymes during early mineralization. It is concluded that 24(R),25(OH)2D3 should not be compared to 1,25(OH)2D3 on the basis of the same effects, since other effects of 24(R),25(OH)2D3 on the developing bone exist, opposite to those of 1,25(OH)2D3; and these could be important for protecting bone from different agents and in determining the nature of early mineral deposited.

Effects of new bisphosphonic acids on tumor-induced bone destruction in the rat

This report is concerned with therapeutic studies utilizing new bisphosphonic acids on tumor-induced osteolytic metastases. The bone metastases on SD rats were induced by intraarterial and intraosseous transplantation of Walker carcinosarcoma 256 B ascites cells. The treatment was carried out using disodium-3-amino-1-hydroxypropylidene-1,1-bisphosphonate (ADP), diglycidyl-[3-(3, 3-bisphosphono-3-hydroxy-propylamino)-2-hydroxypropyl-]urazol++ +-Na2 (DDU) and 1,2,4-triglycidylurazol (TGU). The extent of bone metastases was determined by X-ray on the 5th and 10th days following tumor inoculation, as well as both microradiographically and histologically upon termination of the experiment. High dose DDU produced a clear reduction of the tumor osteolysis, but these positive results were surpassed using APD. The best results were achieved by pretreatment with APD 24 h prior to tumor inoculation.

Iodine-131-labeled diphosphonates for the palliative treatment of bone metastases--III. Considerations of interaction, binding and absorbed dose

General considerations about the possible mechanisms of action of rather low dose ionizing radiation with bone metastases and stimulated nerve fibers reveal that only minute amounts of chemicals are produced by direct interaction of energetic electrons. Thus changes of the chemical milieu due to direct interaction must be ruled out in favour of a radiation-induced trigger reaction which may then initiate a cascade of cellular responses. Organ distribution studies of a series of radioiodinated benzylidenediphosphonates with H-, HO- and H2N- in the alpha- and p-position revealed best results for pHO-NH2 (BDP3). The microscopic distribution of 131I-DBP3 in bone tissue was monitored by autoradiography. Elevated uptake in normal (tibia) and neoplastic bone (experimental osteosarcoma) corresponded with the degree of vascularization and formation of new hydroxylapatite. Unlike the uptake in human osteoblastic bone metastases the experimental osteosarcoma of SD-rats accumulated 131I-BDP3 less than normal bone. This was due to the short volume doubling time, the delay of hydroxyl-apatite deposition and the formation of necroses. Theoretical replacement of 131I in iodinated BDP3 with radioisotopes emitting higher energy electrons yielded best bone metastasis/organ ratios for 32P labeled BDP3. The bone metastasis/bone marrow dose ratio by comparison with 131I labeled BDP3 is, however, almost equal. The isotopes 130I and 133I are not suited to the achievement of higher tumor/background doses although they are higher energy beta- -emitters than 131I. Because of their short physical half life and absence of different kinetics in normal and neoplastic bone no dose enhancement in bone metastases can be attained.

Inflammation-mediated osteopenia in the rat: the effects of artificial granuloma and sham operation on cortical and trabecular bone

Recent studies have established that generalized loss of trabecular bone occurs in the growing rat following day-to-day inflammatory irritation for a period of 3 wk. We can now demonstrate that there are similar effects on bone in milder but more prolonged chronic inflammation (14 wk). Thus, there were significant decreases in trabecular bone mass as well as in cortical bone after weekly subcutaneous injections or implantations of nonspecific irritants. Osteopenia, induced by a single but extensive inflammatory lesion, remained apparent even 14 wk after induction. This indicates that inflammation-mediated osteopenia is at least incompletely reversible. A less pronounced but similar reduction of cortical and trabecular bone was observed in rats following sham operation. This might be of importance in all animal studies on bone metabolism that include surgical procedures.

Inflammation-mediated osteopenia in the rat: a new animal model for pathological loss of bone mass

We have developed a rat model of inflammation-mediated osteopenia. Generalized loss of trabecular bone occurs in the rat after sc injection of nonspecific irritants such as talcum (magnesium silicate) and cotton wool (Cellulose). Although it appears likely that a systemic mediator of bone resorption is responsible for these effects, the loss of bone was not due to increased PTH secretion, since it occurred in parathyroidectomized rats, nor due to excessive 1,25-dihydroxyvitamin-D3 production. In parathyroidectomized rats, this inflammation was associated with significant increase in serum calcium within 4-7 days independent of its cause. Identification and characterization of this mechanism may provide insight into the bone loss associated with chronic inflammatory diseases such as rheumatoid arthritis and periodontal disease.

Foreign body giant cell reaction in lungs, liver and spleen. A complication of long term haemodialysis

Accumulation of a foreign material in grotesque quantities was observed in the macrophages of lung, liver and spleen of a patient on maintenance haemodialysis. The material appeared in macrophages which were found either in groups or singly, without causing epitheloid cell reaction, necrosis or fibrosis. The material was non-isotropic, non-crystalline and did not stain with routine staining procedures. Transmission electron microscopy showed its presence within lysosomal membranes. The nature of the material and the mechanism of its incorporation into the patient remain unclear, but it is conceivable that incorporation is a consequence of longterm interaction of blood and foreign material during haemodialysis. The clinical consequences of such incorporation have to established.

Bone cell kinetics and function during experimental uremia

Bone cell kinetics and function and chondrocyte kinetics were evaluated in uremic rats and their pair-fed controls using quantitative histology and 3H-thymidine labeling. The principle histologic abnormality in the proximal tibial metaphysis of uremic rats was a relative abundance of proliferating and differentiated bone cells. No mineralization abnormalities were observed. There was increased proliferation of bone cells and an increased rate of differentiation of osteoblasts and osteoclast nuclei in uremic animals. There was no change in chondrocyte kinetics, indicating a dissociation of the normal bone elongation and bone maturation processes. The data on osteoclast number and hard tissue suggest individual osteoclasts in uremic animals have sub-normal resorbing efficiency. It is proposed that the cell kinetic alterations are due to secondary hyperparathyroidism. The cause of osteoclast inefficiency is uncertain, but may be related to (1) deficiency of active products of vitamin D; (2) chronic uremia; and/or (3) chronic secondary hyperparathyroidism.

Action of 1,25-dihydroxycholecalciferol on cartilage mineralization and on endosteal lining cells of bone. Experimental in vitro studies

The aim of our study was to answer the following question: 1) Does 1,25-dihydroxycholecalciferol influence the mineralization process directly? 2) How does 1,25-D3 act on the endosteal cell envelope of bone, which is thought to be engaged in the moment to moment regulation of calcium homeostasis? We studied the endosteal surface of calvaria and the epiphyseal cartilage of rachitic rats in a tissue culture system in order to avoid the secondary effects of endogenous hormones or mineral sources. Investigations were carried out using transmission and scanning electron microscopy. Compared with untreated rachitic control specimens, 1,25-D3 (4 X 10(-8) M) did not enhance the mineralization process. We therefore conclude that the established in vivo effect of 1,25-D3 on the mineralization process must be an indirect one. Within 2 h the flat-shaped surface lining cells of calvaria showed a rapid transformation into globiform cells and a loss of cell adhesion. Within two days a second slower transformation into spindle-shaped fibroblast-like proliferating cells occurred. All changes of cell shape were reversible within several days in the absence of 1,25-D3. Obviously, bone matrix fiber texture influences the spatial movement of proliferating cells. The endosteal cell envelope is considered to act as a functional membrane of bone. Starting from this consideration we conclude that the changes of cellular shape described are the morphological basis for the action of 1,25-D3 in the regulation of calcium homeostasis in bone at the cellular level.

Acquired cystic transformation of the kidneys of haemodialysed patients

In the present study, the kidneys of patients who had been on maintenance haemodialysis for variable periods of time were examined at autopsy. In 21 of the 22 patients, multiple pinhead-size to pea-size, non-loculated cysts were observed both in the cortex and the medulla. In some of the cysts (4/20 patients), papillary adenomata were observed which were visible by light microscopy in 3 cases and macroscopically in 1 case. Clinical complications resulting from haemorrhage or neoplastic transformation were not observed in any of the patients of this series. Similar cysts, smaller in size and fewer in number, were also observed in kidneys of uraemic patients who had not been dialysed. Thus, the lesion does not appear to be a specific consequence of maintenance haemodialysis. It appears more likely that extensive cystic transformation of the kidneys of patients in terminal renal failure is made possible by prolonged survival on maintenance haemodialysis. The possibility of malignant transformation of the papillomata cannot be refuted, but epidemiological surveys fail to document more frequent occurrence of renal carcinoma in dialysed patients.