Gross vertebral collapse associated with long-term disodium etidronate treatment for pelvic Paget's disease.

Inhibition of skeletal mineralisation is a well-recognized complication of disodium etidronate therapy that was identified in the earliest studies of its use in osteoporosis and Paget's disease. The effect is seen at lower doses in Paget's disease than in osteoporosis. Several cases of spontaneous fractures occurring in unaffected bones of Paget's patients have been reported. However, we believe the case described here is the most severe example of etidronate-induced osteomalacia published in the literature, featuring widespread vertebral collapse occurring as a consequence of nearly 10 years of uninterrupted etidronate treatment for isolated hemipelvic Paget's disease.

A double-blind, multicentre, placebo-controlled study of tiludronate in Paget's disease of bone.

A multicentre, randomised, placebo-controlled, dose-ranging study was conducted to investigate the therapeutic activity and sustained efficacy of tiludronate (200 mg, 400 mg and 600 mg once daily) taken orally for 12 weeks in patients with Paget's disease. Serum alkaline phosphatase concentrations were compared with baseline at weeks 12 and 24; treatment success was defined as a 50% reduction compared with baseline. Changes in the hydroxyproline: creatinine ratio were also measured. Pain was assessed using the Huskisson Visual Analogue Scale and by questionnaire. Patients completing at least 11 weeks of treatment were followed-up 18 months later by postal questionnaire. Significantly greater numbers of patients in the tiludronate groups successfully responded to treatment compared with the placebo group. A dose-response was observed; the percentage of patients responding to treatment being 31% (200 mg), 52% (400 mg) and 82% (600 mg) at week 12 and 45% (200 mg), 70% (400 mg) and 82% (600 mg) at week 24. Tiludronate treatment also significantly reduced hydroxyproline: creatinine ratios compared with placebo, again showing a dose response. Dose-related gastrointestinal symptoms were the commonest adverse events, occurring in 2.4%, 11.0%, 5.5% and 18.9% of patients receiving placebo and tiludronate 200, 400 and 600 mg daily, respectively. The response to oral tiludronate was sustained for more than 18 months in some patients and there was evidence of a reduction in the longer term complications of the disease. These results show that oral tiludronate is an effective, well-tolerated treatment for Paget's disease; the 400 mg once daily dose appears to offer the optimum balance of efficacy and tolerance.

A morphological and ultrastructural study of bone in osteogenesis imperfecta.

A morphological and electron microscopic study of bone from patients with osteogenesis imperfecta (OI) has been performed. Bone from OI patients from various anatomical sites has been compared with that from normal, age-, site-, and sex-matched controls. The morphology of OI bone appeared variable among patients and sites of bone examined. Immature woven bone and a poor lamellar pattern were the significant morphological features and demonstrated that OI could not be characterized on the basis of a single histological pattern. At the ultrastructural level, a number of previously unreported features were evident. Abnormal collagen fibers and an altered mineral composition were found in many OI patients, however, the panoramic heterogeneity between clinical types and indeed within a single clinical type made it difficult to classify OI in this manner. The presence of intermitochondrial inclusions containing calcium and phosphorus and the presence of a stromal calcification in the bone in some OI patients suggested an abnormal mineral formation. Qualitatively, no obvious difference in the number of osteoblasts or osteoclasts was observed. The morphology and ultrastructure of OI bone were good indicators of the disease and serve a role in assessing the progress of a patient through diagnosis and treatment. This report presents new ultrastructural findings in collagen and in mineral formation in OI compared with normal human bone.

An electron probe X-ray microanalytical study of bone mineral in osteogenesis imperfecta.

A semiquantitative electron probe X-ray microanalytical (XRMA) technique, in conjunction with transmission electron microscopy, was used to compare the calcium to phosphorus (Ca/P) molar ratios in calcium phosphate standards of known composition, in normal bone and in bone from patients with osteogenesis imperfecta (OI). Using a modified routine processing and resin embedding schedule, the measured Ca/P molar ratio of calcium phosphates standards of known composition were found to correlate well with the Ca/P molar ratio based on their respective chemical formulae. This technique was then used to compare the Ca/P molar ratio in normal human bone and in OI bone. The Ca/P ratio values for normal bone (Ca/P = 1.631) correlated well with those for chemically prepared hydroxyapatite (Ca/P = 1.602), but in bone from OI patients, the Ca/P molar ratio was significantly lower (Ca/P = 1.488). This study has shown that there is a lower Ca/P molar ratio in OI bone compared with normal, matched bone. This suggests that the mineral deviates from the carbanoapatite usually found in bone. Isomorphous substitutions in the carbanoapatite lattice could account for this although this study has neither proved nor disproved this. The altered bone mineral is another factor that could contribute to the increased fracture rate observed in OI.

Metabolic balance studies of mineral supplementation in osteoporosis.

1. We studied the effect of mineral supplementation and its duration in osteoporosis by analysing the calcium and phosphorus balances of 49 treated osteoporotic patients whose median length of calcium treatment was 19 weeks with a range of 8 days to over 4 years. Forty-four studies satisfied statistical criteria of reproducibility and included 35 women (10 also receiving oestrogen replacement therapy) and nine men. 2. Mean calcium balance was positive in women taking calcium supplements alone, +1.9 +/- 2.5 mmol daily (P less than 0.002), and was significantly more positive (P less than 0.05) in women also taking oestrogens, +4.2 +/- 2.1 mmol daily. Calcium balance was not significantly positive in men. 3. Calcium balance correlated negatively with duration of supplementation, but significantly, only when duration of supplementation was expressed logarithmically (r = -0.401, P less than 0.01) giving the regression equation y = 4.2-1.6 log x, where y = calcium balance in mol/day and x = duration of supplementation in weeks. Theoretical net calcium retention, without allowance for dermal loss, could be calculated by integration. 4. Mean phosphorus balance was significantly positive in both groups of women and in the whole population. Although its correlation with duration of supplementation did not reach statistical significance (P less than 0.1), the ratio of the regression slopes for calcium and phosphorus, 1.5:1, corresponded to their molar ratio in bone. 5. These statistics are, we believe, the first to describe an exponential decline in calcium balance during mineral treatment of osteoporosis, but they firmly suggest that such treatment, with or without oestrogen therapy, conveys temporary benefit.

Depressed levels of circulating menaquinones in patients with osteoporotic fractures of the spine and femoral neck.

Vitamin K1 functions in the conversion of glutamate residues, present in certain bone peptides, into the putatively active gamma-carboxyglutamate form. We have shown previously that the circulating levels of vitamin K1 are depressed in osteoporotic patients. However, it is known that menaquinones (vitamin K2:MK) may be more effective than vitamin K1 in this conversion of the inactive to active form of glutamate residues. A procedure for measuring such menaquinones has now demonstrated a marked deficiency of MK-7 and MK-8 in patients with osteoporotic fractures. It is suggested that estimates of circulating levels of K1, MK-7, and MK-8 might provide a biochemical risk marker of osteoporotic fractures.

Fluoride therapy and parathyroid hormone activity in osteoporosis.

1. To determine the relationships between parathyroid hormone activity and long-term sodium fluoride therapy in osteoporosis, cytochemical bioassays (for biologically active parathyroid hormone) were performed in 22 osteoporotic control patients and in 18 patients after 15 +/- 10 months of treatment (60 mg of sodium fluoride daily). Ten patients were studied longitudinally by repeated metabolic balances and were therefore common to both groups. All patients were receiving mineral supplements. 2. Cross-sectional data showed a fourfold mean increase in biologically active parathyroid hormone on fluoride treatment (P less than 0.005) together with a 51% increase in serum alkaline phosphatase (P less than 0.005). Longitudinal data showed, in addition, a significant increase in the calcium balance of 2.4 +/- 1.2 (SEM) mmol daily (P less than 0.05) and the development of a positive phosphorus balance (P less than 0.02). 3. Fluoride-treated patients were then analysed in two groups according to the level of biologically active parathyroid hormone. Thirty-two per cent of values were above the upper limit of normal (18 pg/ml). The mean serum alkaline phosphatase level in this group showed no elevation above that of the control patients, the overall rise being accounted for entirely by patients with normal levels of biologically active parathyroid hormone. High levels of biologically active parathyroid hormone were also associated with relative hypophosphataemia (P less than 0.01), relative hypercalciuria (P less than 0.05) and an increased urine/faecal calcium ratio (P less than 0.025). 4. Results show that long-term fluoride and calcium therapy increase biologically active parathyroid hormone in osteoporosis and that excessive parathyroid hormone activity may account for certain features of the refractory state.

Immunohistological study of oestrogen receptors in breast carcinomas that are biochemically receptor negative.

The reliability of an immunohistological method, applied to paraffin wax sections, was assessed for determination of oestrogen receptor content of biochemically oestrogen receptor negative breast carcinomata. Sixty consecutive tumours with oestrogen receptor concentrations of less than 10 fmol/mg cytosol protein, as estimated by dextran-coated charcoal biochemical assay, were examined. Paraffin wax sections were treated with DNAse before applying a peroxidase-anti-peroxidase method using ER-ICA monoclonal antibodies. Fifty one cases (85%) were negative, six (10%) weakly positive, and three (5%) were moderately positive. No strongly positive cases were seen. It is suggested that cases with weakly positive staining, especially when localised to a small area, should be regarded as negative. On the other hand, as the three moderately stained cases included two small tubular carcinomas and an invasive ductal carcinoma with high progesterone receptor concentrations, it is more likely that the biochemical assay in these cases represented false negative results due to sampling error or inclusion of fibrous or other non-neoplastic tissue in the assayed samples. It is concluded that the immunohistological method used here is fairly reliable and would be especially valuable for determination of oestrogen receptor content in small, mammographically detected tumours from which no tissue would be available for biochemical assay or frozen section examination.

Oestrogen receptors in mucinous carcinoma of the breast: an immunohistological study using paraffin wax sections.

An immunohistological method (Shintaku-Said method) for the demonstration of oestrogen receptors in routinely processed paraffin wax embedded tissue was applied to 19 cases of mucinous carcinoma of the breast. Seventeen (89%) tumours showed variable degrees of positivity and two were negative. In eight cases the receptors were also assayed biochemically using a dextran-coated charcoal method, and the results of the two methods showed good correlation. No difference in the distribution of positive and negative cases was noted between pure and mixed mucinous tumours, and in the latter group the pattern of staining of the mucinous elements was similar to that seen in the solid elements. It is concluded that the major advantage of this method is its ability to offer for study the distribution of the receptors in individual cells and specific histological structures. The results also indicate that most mucinous carcinomas of the breast are oestrogen receptor positive, irrespective of whether they are pure or mixed type.

Ultrastructural features of the osteoid of patients with fibrogenesis imperfecta ossium.

The osteoid of a patient with Fibrogenesis Imperfecta Ossium is described. Three iliac crest biopsies were taken; firstly before treatment, secondly after calcitriol therapy and finally after successful treatment with melphalan and prednisolone. In the pretreatment biopsy the osteoid was greatly enlarged, showed complete absence of the birefringence characteristic of oriented collagen fibers, and at ultrastructural level was shown to be composed of abnormal collagen fibrils. The fibrils were often curved and were extremely variable in thickness. Calcification within the osteoid took the form of calcospherites and spread of calcification from these to collagen fibrils was greatly delayed. In the second biopsy two aspects of osteoid ultrastructure were noted; some samples resembled the first biopsy, but others had a different organization. The osteoid of these samples had two regions: an inner region containing abnormal collagen fibrils and an outer region composed of moderately electron-dense amorphous material. The osteoblasts associated with this region were clearly highly biosynthetically active. The third biopsy, after treatment with Melphalan and prednisolone, showed a reversion to more normal bone ultrastructure with uniform, oriented collagen fibrils and prompt mineralization resulting in narrow osteoid seams. Remnants of the original abnormal osteoid were present in the marrow space as calcified debris. Reasons for the success of this therapeutic regime are unclear; however, some speculation is made as to the possible roles of the cytotoxic drug and the glucocorticoid in the regression of this condition.

Fluoride therapy in osteoporosis: acute effects on parathyroid and mineral homoeostasis.

1. Acute metabolic effects of sodium fluoride therapy were analysed among 41 osteoporotic patients already receiving large calcium supplements, 33 of whom underwent simultaneous metabolic balance studies. 2. Mean serum calcium fell transiently within 24-48 h by 0.03 +/- 0.07 (SD) mmol/l (P less than 0.01) and phosphorus by 0.06 +/- 0.08 (SD) mmol/l (P less than 0.001). In a subgroup, ionized calcium fell and biologically active parathyroid hormone (bio-PTH) rose more than fivefold (P less than 0.01). Urine calcium rose after an insignificant fall. 3. Pretreatment calcium and phosphorus balances were significantly positive and did not change overall during the first 8 days of treatment. However, on analysing balances in two groups relative to serum changes, in patients whose serum levels changed least sodium fluoride increased faecal calcium (P less than 0.025) and phosphorus (P less than 0.01) and reduced calcium balance (P less than 0.01), giving a mean balance difference between the two groups of 2.1 mmol daily (P less than 0.001). 4. Very small changes in serum levels therefore indicate well-marked metabolic responses: sodium fluoride acutely stimulates bio-PTH activity and must also enhance mineral uptake from circulation into tissue(s). By separate and opposing action(s) it inhibits intestinal calcium and phosphorus absorption, predominantly in those whose serum levels remain stable. All these effects may be relevant to long-term therapeutic results.