A phase 2 study of MK-5442, a calcium-sensing receptor antagonist, in postmenopausal women with osteoporosis after long-term use of oral bisphosphonates.

UNLABELLED: In women with osteoporosis treated with alendronate for >12 months and oral bisphosphonates for >3 of the last 4 years, switching to MK-5442, a calcium receptor antagonist, stimulated endogenous parathyroid hormone (PTH) secretion and increased bone turnover marker levels, but produced a decline in bone mineral density (BMD) at all sites. INTRODUCTION: This study assessed the effects of switching from long-term oral bisphosphonate therapy to the calcium-sensing receptor antagonist MK-5442 on BMD and bone turnover markers (BTMs) in post-menopausal women with osteoporosis. METHODS: This randomized, active and placebo-controlled, dose-ranging study enrolled 526 postmenopausal women, who had taken alendronate (ALN) for ≥12 months preceding the trial and any oral bisphosphonate for ≥3 of the preceding 4 years and had spine or hip BMD T-scores ≤-2.5 or ≤-1.5 with ≥1 prior fragility fracture. Women were randomized to continue ALN 70 mg weekly or switch to MK-5442 (5, 7.5, 10, or 15 mg daily) or placebo. RESULTS: Switching from ALN to MK-5442 produced a dose-dependent parathyroid hormone (PTH) pulse of threefold to sixfold above baseline at 1 h, with PTH levels that remained twofold to threefold above baseline at 4 h and returned to baseline by 24 h. Switching to MK-5442 or placebo increased BTM levels compared to baseline within 3 months and MK-5442 10 mg increased BTM levels compared to placebo by 6 months. With all MK-5442 doses and placebo, spine and hip BMD declined from baseline, and at 12 months, BMD levels were below those who continued ALN (all groups P < 0.05 vs ALN). There was also a dose-dependent increase in the incidence of hypercalcemia with MK-5442. CONCLUSION: Switching from ALN to MK-5442 resulted in a pulsatile increase in PTH and increases in BTMs, but a decline in BMD compared with continued ALN. MK-5442 is not a viable option for the treatment of osteoporosis.

Serum insulin-like growth factor-I, insulin-like growth factor binding proteins, and bone mineral content in hyperthyroidism.

The mechanism by which thyroid hormones promote bone growth has not yet been elucidated. In vitro, thyroid hormones stimulate insulin-like growth factor-I (IGF-I) production by osteoblasts, which is important for the anabolic effects of the hormone on bone. To determine whether the IGF-I/IGF binding protein (IGFBP) profile is affected when thyroid hormone production is altered in vivo, we studied 36 women who had recently been diagnosed with hyperthyroidism (age: 29-67 years; 19 with Graves' disease, 17 with toxic nodular goiter) and 36 age-matched healthy women as controls. Serum IGF-I, and its binding proteins (IGFBP-3, IGFBP-4, and IGFBP-5), as well as bone mineral density (BMD) at the lumbar spine, femoral neck, and radius midshaft were measured before and 1 year after antithyroid (methimazole) treatment. Serum IGF-I levels were significantly increased in the hyperthyroid patients before treatment (214 +/- 18.2 ng/mL vs. 145 +/- 21.3 ng/mL; p < 0.05). There was no difference in IGF-I levels of patients with Graves' disease and toxic nodular goiter. Serum IGF-I concentrations returned to normal after treatment with methimazole. Serum IGFBP-3 and IGFBP-4 values were significantly elevated in the hyperthyroid group before treatment (3960 +/- 220 ng/mL and 749.7 +/- 53.1 ng/mL vs. 2701 +/- 180 ng/mL and 489.9 +/- 32.4 ng/mL; p < 0.05 and p < 0.01, respectively) and were reduced to those of controls after treatment. Serum IGFBP-5 of hyperthyroid subjects was not different from that of controls either before or after therapy. Serum free thyroxine showed a positive correlation with serum levels of IGF-I (r = 0.73, p < 0.05), IGFBP-3 (r = 0.59, p < 0.05), and IGFBP-4 (r = 0.67, p < 0.05) but not IGFBP-5. BMD at the radius midshaft was significantly lower in hyperthyroid patients at the start of the study and showed a positive correlation with serum IGF-I (r = 0.58; p < 0.001) and a negative correlation with IGFBP-4 (r = -0.61; p < 0.05). Radius BMD showed a 7.2% increase in the hyperthyroid group after 1 year of methimazole treatment, and the correlation between BMD and serum IGF-I disappeared. Our data indicate that thyroid hormones may influence the IGF-I/IGFBP system in vivo in hyperthyroidism. The anabolic effects of increased levels of IGF-I may be limited in hyperthyroidism due to the increases of inhibitory IGFBPs that can counteract the anabolic effects and contribute to the observed net bone loss.

Prevention of corticosteroid-induced osteoporosis by alfacalcidol.

We studied the effect of alphacalcidol (1-alpha-hydroxycholecalciferol) on bone metabolism in patients who were placed on glucocorticoid therapy. We selected 41 women (age: 32-52 yrs) who were recently diagnosed with systemic lupus erythematodes, multiple sclerosis, rheumatoid arthritis or asthma bronchiale. Patients did not have other disease or take drugs known to influence bone metabolism. Patients were randomly enrolled into two groups and were given 5-25 mg prednisone daily. After 4 weeks, group A (n = 21) received 0.5-1.0 microgram (mean = 0.54 +/- 0.03 microgram) alphacalcidol and group B (control; n = 20) was given 500 mg calcium daily for three years. There were no significant differences in age and steroid doses between groups. Serum calcium (Ca), osteocalcin (OC), collagen I C-terminal propeptide (PICP), parathyroid hormone (PTH), and urinary calcium and deoxypyridinoline crosslink excretion (DPD) were measured before corticosteroid administration, and before alphacalcidol or calcium treatment as well as 6 weeks, 6 months, and 1, 2, and 3 years later. Bone mineral density (BMD) was examined before treatment and 6 months, 1, 2, and 3 years later by DEXA and SPA. OC and PICP decreased significantly after 4 weeks on steroid in both groups and increased in group A but not in group B after 6 weeks of treatment with alphacalcidol and remained unchanged for 3 years. Serum PTH increased in both groups after 4 weeks of glucocorticoid treatment and was reduced in group A, but not in group B, after 6 weeks on alphacalcidol. Serum Ca, urinary Ca, and DPD did not change significantly in either group during the study period. Lumbar spine and femoral neck BMD were significantly reduced in group B after 6 months and 1 year, respectively, and continued to decrease during the study, while no significant change in group A was observed. BMD of the radius did not change in either group for 2 years but there was a significant reduction by the third year in group B. Based on these results, alphacalcidol treatment appears to be effective in preventing glucocorticoid-induced bone loss in these patients by reducing secondary hyperparathyroidism and stimulating bone formation.

[Current diagnostic method, prognosis estimation and therapy of papillary thyroid cancer: recommendations of the medical universities and the National Oncologic Institute of Budapest]. / A papillaris pajzsmirigy-carcinoma korszerü kivizsgálása, prognózisbecslése és kezelése: az orvostudományi egyetemek és az Országos Onkológiai Intézet ajánlása.

Physical examination, cervical ultrasonography (US) and aspiration cytology are the mainstays of the preoperative diagnostics of papillary thyroid carcinoma. For the staging of suspected malignant cases, cervical and mediastinal CT (MRI for inconclusive results) is indicated before any surgery. The end-result of primary treatment is assessed by total-body iodine scintigraphy and the serum human thyroglobulin (hTG) level. For long-term follow-up, physical examination and the serum hTG level are the most reliable tools (6-monthly), supplemented by cervical US and chest X-ray (yearly), and total-body iodine scintigraphy (2-yearly). If these furnish positive results, further examinations may be indicated. In suspected relapses of hTG non-producing and iodine non-accumulating papillary carcinomas, 201thallium chloride or 99mTc-sesta-MIBI (methoxy-isobutyl-isonitrile) scintigraphy, and positron emission tomography with 18fluoro-deoxyglucose or 11C-methionine may be of help. For estimation of the prognosis (cause-specific survival) of the patients, the MACIS score system of the Mayo Clinic is widely accepted, the patients being divided into low-risk and intermediate/high-risk categories. The recommended standard surgical intervention is near-total thyroidectomy (2-4 g residual glandular tissue left at the upper pole of the less-involved lobe), with a central cervical lymph node dissection for diagnostic purposes. In cases of lymph node dissemination, dissection (radical, modified radical, selective or microdissection) of any of the involved compartments (central, right or left cervical, or upper mediastinal) is indicated for therapeutic reasons, the method of which is depending on the extent of the metastatic involvement. Following adequate surgical intervention, no adjuvant radioiodine therapy is indicated for low-risk cases with a tumour of less than 1 cm diameter. For other low-risk or intermediate/high-risk patients, radioiodine ablation (R0N0M0) or a therapeutic radioiodine dosage (R2N1M1) is indicated. In cases at high-risk of local/regional relapse and in radioiodine non-accumulating tumorous cases, external radiotherapy may be applied. Thyroid hormone medication in a TSH suppressive dose is indicated during the first 5 postsurgical years: the goal is to achieve a TSH level below 0.1 (determined by a 3rd generation assay). If no relapse occurs or the case is a low-risk one, following the 5 years, it is enough to maintain the TSH level in a subnormal range (0.1-0.3).

The blood spot thyrotropin method is not adequate to screen for hypothyroidism in the elderly living in abundant-iodine intake areas: comparison to sensitive thyrotropin measurements.

We investigated whether the blood spot thyrotropin (TSH) method was adequate for screening elderly subjects with abundant iodine intake (median excretion 330 microg/g creatinine) for hypothyroidism. In 97 healthy adults (group A), 210 nursing home residents (group B) and 265 elderly subjects living at home (group C) serum (sensitivity < 0.02 mU/L, cost 1.2 U.S. dollars [USD]) and blood spot TSH (sensitivity < 1.0 mU/L, cost 0.4 USD) were measured, and the sensitivity and specificity of different blood spot TSH cutoff points to detect cases with elevated serum TSH were calculated. Elevated (> 3.5 mU/L) serum TSH levels (group A, 6.2%; group B, 16.2%; group C, 22.3%; B > A, p = 0.025; C > A, p < 0.001) were detected with the required sensitivity of greater than 0.9 only if the cutoff point of the blood spot TSH was set as low as 2.5 mU/L, but this led to a considerable loss of specificity. At cutoff point 2.5 mU/L, the rate of positivity was 39.3% and the cost of blood spot screening/person increased to 0.88 USD, considering that positive cases have to be rechecked by serum TSH to exclude false positivity. Cases with significantly elevated (> 10.0 mU/L) serum TSH (group A, 1.03%; group B, 2.85%; group C, 2.20%) were detected at blood spot cutoff points 10.0-4.0 mU/L with a sensitivity of 1.0 and without considerable loss of specificity. We conclude that while screening for hypothyroidism in the elderly population with abundant iodine intake is justified by the high prevalence of elevated ultrasensitive serum TSH values, the sensitivity of the blood spot method is insufficient to detect the subclinical hypothyroidism accurately and would, therefore, fail to detect most affected subjects.

The efficacy of long term thyrostatic treatment in elderly patients with toxic nodular goitre compared to radioiodine therapy with different doses.

The objective of the study was to investigate the efficacy of long term thyrostatic versus radioiodine treatment of hyperthyroidism in old age. Our study is a retrospective analysis of the therapeutical outcome in 66 patients over 60 years of age with toxic nodular goitre. The patients were divided in two groups: Group A: 28 patients on methimazole treatment: starting dose 5-30, median (M) 10 mg, maintenance dose 2.5-15 (M = 5) mg, follow up 6 to 240 months (M = 23.5 months). Group B: 38 patients treated by either 100-300 MBq (N = 14, subgroup B1) or 325-1000 MBq (N = 24, subgroup B2) 131I, follow up: 18 to 156 months (M = 48 months). The efficacy of the different therapeutical approaches were compared by calculating the occurrence rate of persisting and relapsing thyroid dysfunctions and associated side effects. The 28 patients on methimazole treatment became euthyroid after 1-16 (M = 5) months but numerous relapses occurred in the follow up: hyperthyroidism, clinical: 5, subclinical 13, (relapse duration: M = 8 months; associated symptoms: hypertension in 4, cardiac arrhythmia in 3, cerebral embolism in 1, angina pectoris in 2, weight loss in 2 cases). Poor patient's compliance (9/28) or dose reduction by the physician (5/28) were the main causes of the relapses. Transient clinical (3 cases) or subclinical (6 cases) hypothyroidism also occurred (duration: 1-3 M = 2 months, no clinical symptoms). In 7 out of 14 (50%) patients receiving 100-300 MBq 131I (Group B1) hyperthyroidism persisted (versus 4/24 -16.7%- in Group B2 following 325-1000 MBq 131I; chi2(1) = 4.78 P = 0.028), methimazole treatment had to be continued in 9/14 patients (64.3%) (versus 5/24 -20.8%)- in Group B2., chi2(1) = 7.18 P = 0.0074) and in 5/14 (35.7%) the radiotherapy had to be repeated (versus 5/24 -020.8%- in Group B2, not sign.). Our conclusions are: 1) long term thyrostatic treatment is not safe in elderly patients with toxic nodular hyperthyroidism, mainly because of poor compliance or dose reduction by the physician; 2) radioiodine treatment as the first choice should be recommended for these patients and higher doses should be preferred.

Dynorphin A (1-13) neurotoxicity in vitro: opioid and non-opioid mechanisms in mouse spinal cord neurons.

Dynorphin A is an endogenous opioid peptide that preferentially activates kappa-opioid receptors and is antinociceptive at physiological concentrations. Levels of dynorphin A and a major metabolite, dynorphin A (1-13), increase significantly following spinal cord trauma and reportedly contribute to neurodegeneration associated with secondary injury. Interestingly, both kappa-opioid and N-methyl-D-aspartate (NMDA) receptor antagonists can modulate dynorphin toxicity, suggesting that dynorphin is acting (directly or indirectly) through kappa-opioid and/or NMDA receptor types. Despite these findings, few studies have systematically explored dynorphin toxicity at the cellular level in defined populations of neurons coexpressing kappa-opioid and NMDA receptors. To address this question, we isolated populations of neurons enriched in both kappa-opioid and NMDA receptors from embryonic mouse spinal cord and examined the effects of dynorphin A (1-13) on intracellular calcium concentration ([Ca2+]i) and neuronal survival in vitro. Time-lapse photography was used to repeatedly follow the same neurons before and during experimental treatments. At micromolar concentrations, dynorphin A (1-13) elevated [Ca2+]i and caused a significant loss of neurons. The excitotoxic effects were prevented by MK-801 (Dizocilpine) (10 microM), 2-amino-5-phosphopentanoic acid (100 microM), or 7-chlorokynurenic acid (100 microM)--suggesting that dynorphin A (1-13) was acting (directly or indirectly) through NMDA receptors. In contrast, cotreatment with (-)-naloxone (3 microM), or the more selective kappa-opioid receptor antagonist nor-binaltorphimine (3 microM), exacerbated dynorphin A (1-13)-induced neuronal loss; however, cell losses were not enhanced by the inactive stereoisomer (+)-naloxone (3 microM). Neuronal losses were not seen with exposure to the opioid antagonists alone (10 microM). Thus, opioid receptor blockade significantly increased toxicity, but only in the presence of excitotoxic levels of dynorphin. This provided indirect evidence that dynorphin also stimulates kappa-opioid receptors and suggests that kappa receptor activation may be moderately neuroprotective in the presence of an excitotoxic insult. Our findings suggest that dynorphin A (1-13) can have paradoxical effects on neuronal viability through both opioid and non-opioid (glutamatergic) receptor-mediated actions. Therefore, dynorphin A potentially modulates secondary neurodegeneration in the spinal cord through complex interactions involving multiple receptors and signaling pathways.

Effects of different regimens of sodium fluoride treatment for osteoporosis on the structure, remodeling and mineralization of bone.

We compared initial and final bone histomorphometric findings in 66 osteoporotic patients treated with sodium fluoride (NaF) according to three regimens, and in 7 osteoporotic patients who did not receive NaF. Fourteen patients received continuous NaF 75 mg/day (high-dose) with calcium 1500 mg/day for a mean of 41 months. Twenty-six patients received continuous NaF 50 mg/day (low-dose) with calcium 2000 mg/day for a mean of 15 months, either with (10 patients) or without (16 patients) vitamin D. Twenty-six patients received cyclical low-dose NaF, alternating with vitamin D, for a mean of 15 months and a total treatment duration of 28 months, of whom 14 were and 12 were not on NaF at the time of the second biopsy. Disregarding differences between regimens, there were significant increases in total and mineralized bone volume and trabecular thickness and nonsignificant decreases in these measurements in the control group. Fluoride-induced bone formation was exclusively appositional with no evidence for the creation of new trabeculae. The effect of low-dose NaF on bone structure was the same when the same total dose was given continuously or intermittently, and when the patient was or was not taking vitamin D. The increases in total and mineralized bone volume but not trabecular thickness were greater with high-dose than with low-dose NaF. Low-dose NaF caused modest but significant increases in all osteoid indices, and modest but significant declines in adjusted apposition rate and osteoid maturation rate and no change in bone formation rate. With high-dose NaF, the increase in BV/TV was greater but all indices of osteoid accumulation were much higher and all indices of impaired osteoblast function and mineralization were much lower, and 12 of 14 patients had some form of osteomalacia. This occurred also in 3 of 30 patients treated with low-dose NaF who were not taking vitamin D; the mean increase in osteoid thickness was significantly greater in these patients than in 22 low-dose patients who were taking vitamin D. We conclude: (1) The inconsistent effect of NaF in increasing bone strength is partly due to failure to restore connectivity in patients with severe bone loss and partly due to substantial osteoid accumulation. (2) Even low-dose NaF causes impaired osteoblast function, but this is much greater with high-dose prolonged therapy. (3) There is an unexplained discrepancy between the increase in bone formation implied by increases in spinal bone mineral and the lack of increase in bone formation measured histomorphometrically. (4) Defective mineralization is more closely related to the total cumulative dose of NaF than to the duration of treatment, and with low-dose treatment may be preventable by vitamin D. (5) Future clinical trials should be carried out with smaller doses of NaF and before there has been substantial loss of horizontal trabeculae in the spine.

Decreased serum IGF-I and dehydroepiandrosterone sulphate may be risk factors for the development of reduced bone mass in postmenopausal women with endogenous subclinical hyperthyroidism.

Postmenopausal women with endogenous subclinical hyperthyroidism seem to have reduced bone mass, which does not correlate with serum thyroid hormone levels. Relative insufficiencies of IGF-I and dehydroepiandrosterone sulphate (DHEAS) might be additional risk factors for low bone density in these patients. We measured IGF-I, IGF-binding protein-3 (IGFBP-3) and DHEAS levels together with bone mineral density (BMD) of the femoral neck and lumbar spine in women with an autonomously functioning thyroid nodule. Sixty-three women were classified as subclinical hyperthyroid (31 pre- and 32 postmenopausal) and 39 as overt hyperthyroid (16 pre- and 23 postmenopausal) and results were compared with data obtained from 41 age-matched euthyroid healthy women. In premenopausal women BMD was reduced only in the overt hyperthyroid group, and only in the spine, to 92% (P < 0.05). Serum IGF-I as well as IGFBP-3 were increased in the manifest hyperthyroid group, to 157% (P < 0.001) and 129% (P < 0.05) respectively, whereas DHEAS levels did not change in either premenopausal patient group. In postmenopausal women BMD was significantly reduced both in the subclinical hyperthyroid group (spine to 90% and femoral neck to 88%; P < 0.05), as well as in the hyperthyroid group (spine to 78% and femoral neck to 86%; P < 0.01). In contrast to premenopausal women, serum IGF-I and IGFBP-3 did not change in the two groups who were postmenopausal and serum DHEAS levels were reduced to 58% (P < 0.001) in both postmenopausal groups with subclinical as well as overt hyperthyroidism. In the same two groups of patients, serum IGF-I and DHEAS levels correlated with BMD (femoral neck; both r = 0.50, P < 0.05). In conclusion, women with a solitary autonomous thyroid nodule with subclinical hyperthyroidism have reduced BMD only if they are postmenopausal. This is probably due to the effect of subtle increases in thyroid hormone production together with lack of oestrogen protection of the skeleton. But additional risk factors for the development of enhanced bone loss might be a state of relative IGF-I and DHEAS insufficiency in these patients as well as in postmenopausal women with overt hyperthyroidism.

Serum interleukin-6 and bone metabolism in patients with thyroid function disorders.

To determine the possible involvement of interleukin-6 (IL-6) in the bone loss of hyperthyroidism, relationships between thyroid status, biochemical and densitometric parameters of bone metabolism, and IL-6 were studied in female subjects. Patients with hyperthyroidism caused by either toxic nodular goiter or Graves' disease had significantly higher serum IL-6 concentrations than normal controls. Within the control group, serum IL-6 was higher in postmenopausal than in premenopausal women, but this influence of menopausal status was not seen in the hyperthyroid patients. The production of IL-6 by blood mononuclear cells was higher in cells from the hyperthyroid women. Bone turnover was increased in the hyperthyroid patients based on serum osteocalcin and urinary deoxypyridinoline excretion, and the hyperthyroid group also had reduced radius bone mineral content (BMC). A subgroup of hyperthyroid patients who had the lowest BMC (values more than 1 SD below normal age-matched controls) also had serum IL-6 concentrations significantly greater than those of hyperthyroid patients showing less reduction of BMC. The correlations observed in this study support the possibility that IL-6 plays a role in mediating the bone loss that results from excess thyroid hormone.

[Thyroid and osteoporosis]. / Pajzsmirigy és osteoporosis.

Data indicate that in overt hyperthyroidism the equilibrium of the synthetic and degradation processes suffers a change in the bone, there exists an increased turnover with a predominance of resorption. Recently many new sensitive markers have been developed which are correctly reflecting the altered bone metabolism in hyperthyroidism. It is demonstrated that overt hyperthyroidism is a risk factor for osteoporosis. Osteopenia improves after the successful treatment of the disease, however, a complete restitution may ensue only after years. Lately attention has been focused on subclinical hyperthyroidism. Findings indicate that osteoporosis can not be demonstrated in premenopausal women with endogenous subclinical hyperthyroidism, while this disease may play a role in the development of osteopenia in part of post menopausal women. Likewise, in a postmenopausal women receiving levothyroxine replacement therapy an increased circumspection is required and it is recommended to avoid the administration of a levothyroxine dose suppressing TSH secretion. When suppression treatment is necessary the administration of the lowest, but the TSH secretion already suppressing levothyroxine dose is proposed.

Effect of phenothiazines, benzo[a] phenothiazines, benz[c]acridines and Pentaglobin on endotoxin.

The endotoxin neutralizing effects of several phenothiazines, benzophenothiazines and Pentaglobin (control) were investigated by spectrophotometry, tumor necrosis factor (TNF) induction and the conventional Limulus test. In animal experiments, some beneficial effects of complex forming compounds were found, however, the compounds could not completely inactivate the biological effect of endotoxin in the Limulus test. The complex formation between endotoxin and the compounds were revealed in spectrophotometry. The TNF inducing effect of compound-endotoxin complexes was markedly reduced by some phenothiazines and benzo[a]phenothiazines in leukocytes. Benz[c]acridines and Pentaglobin could not neutralize completely the TNF induction of E. coli endotoxin. The recent findings indicate that multifocal effects of phenothiazines and benzophenothiazines can be responsible for anti-endotoxin action in vivo. Hypotensive action in experimental animals was reduced by some phenothiazines in some preliminary experiments.

Replacement therapy with imiglucerase for type 1 Gaucher's disease.

Gaucher's disease, the most common sphingolipidosis, is caused by deficiency of the lysosomal enzyme glucocerebrosidase. Therapy with alglucerase (the placental enzyme) is safe and effective at various dosing regimens. We report the use of low-dose imiglucerase (the recombinant enzyme) at two dosing schedules: 15 u/kg once fortnightly or 2.5 u/kg thrice weekly. Mean reductions in spleen and liver volumes achieved (in all ten patients) by imiglucerase at 12 months were 36.4% and 14.5%, respectively; mean increase in haemoglobin and platelet counts were 13.4% and 25.7%. There were no serious side-effects. No significant differences were observed between the two schedules. Low-dose low-frequency imiglucerase may be an alternative cost-effective approach with satisfactory clinical response and uncompromised quality of life.

Relations between histologic indices of bone formation: implications for the pathogenesis of spinal osteoporosis.

Wall thickness, a major determinant of trabecular thickness, falls with age and falls further in osteoporosis. To estimate the importance of defective osteoblast recruitment in the pathogenesis of this defect, we compared various histologic indices of bone formation in iliac bone biopsies in three groups of subjects--healthy premenopausal women, healthy postmenopausal women, and patients with postmenopausal osteoporosis and at least one non-traumatic vertebral compression fracture. Indices that reflect the frequency of activation of bone remodeling and consequent birth rate of new teams of osteoblasts (osteoid surface, mineralizing surface, osteoblast surface, and bone formation rate, all expressed per unit of bone surface) were each higher in healthy subjects who were postmenopausal than in those who were premenopausal, but lower in osteoporotic than in normal postmenopausal women. In each group, the primary surface measurements were significantly correlated with each other, but the correlation was less close in those with osteoporosis. Indices that reflect the average collective performance of individual teams of osteoblasts (mineralizing surface and osteoblast surface per unit of osteoid surface, mineral apposition rate, adjusted apposition rate, and wall thickness) were all lower in postmenopausal than in premenopausal normal subjects, and even lower in those with postmenopausal osteoporosis. The parameters of the regression lines relating bone formation rate to osteoblast surface were essentially the same in each group, indicating that bone formation rate per unit of osteoblast surface was unaffected by age or menopause, and was the same in osteoporosis as in healthy subjects of similar age.(ABSTRACT TRUNCATED AT 250 WORDS)

[Zn-content of erythrocytes in overt and subclinical hyperthyroidism]. / Vörösvérsejt Zn-tartalom vizsgálata manifeszt és szubklinikus hyperthyreosisban.

Assaying the markers in blood reflecting thyroid hormone effect at peripheral tissue level previous data revealing a significantly decreased red-blood cell Zn-content in overt hyperthyroidism compared to euthyroid controls could be confirmed (p < 0.001). In patients with thyrotoxicosis during Metothyrin treatment the Zn-concentration of red-blood-cells normalised about 8 weeks later than the abnormally elevated serum thyroxine and triiodothyronine levels. On the basis of the present findings it is assumed that the Zn-concentration of red-blood cells reflects to a certain degree the circulating levels of thyroid hormones 2 to 3 months prior to the performed examination. The measurement of red-blood cell Zn-content does not seem to be a reliable method for the detection of a possible "tissue"-thyrotoxicosis in cases of subclinical hyperthyroidism.

Alfacalcidol (alpha D3) and calcium in osteoporosis.

In a prospective, randomized study, 66 osteoporotic postmenopausal women (mean age, 67 years) were scheduled to receive either alfacalcidol 0.25 microgram twice daily together with calcium 500 mg twice daily (treatment group, n = 24) or placebo twice daily with calcium 500 mg twice daily (control group, n = 42) for three years. In the treatment group, bone mineral content at the distal radius may have increased by 2% compared to a significant decrease of 7.8% in the control group. The difference between the two groups was also significant. Since the dose of alfacalcidol and calcium remained unadjusted, frequent hypercalciuria, as well as occasional mild, transient elevations of serum calcium, were observed in the treatment group. No changes in serum creatinine levels or creatinine clearance throughout the study were observed. The two groups did not differ with respect to the frequency of clinical side effects, which were mainly gastrointestinal and probably related to the calcium supplementation. Alfacalcidol and calcium may prevent further bone loss in women suffering from postmenopausal osteoporosis.