[Calcium and bone mass at different periods of life]

In this review we report some considerations on the relationships between calcium intake and bone density during life time, with particular regard to postmenopausal women. We also report some practical aspects concerning calcium salt supplementation.

Clinical aspects of early increase in serum gamma-glutamyl transferase in cerebral infarction

Gamma-glutamyl transferase (GGT) serum levels were measured in 42 female patients within 72 hours, and on day 10, after an ischaemic cerebral infarction (CI) and correlated with neurological impairment at admission and with mortality during hospitalization. Mean +/- SEM GGT serum value within 72 hours after CI was significantly higher compared to the mean +/- SEM value observed in control subjects (26.7 +/- 2.5 vs 16.5 +/- 1.2 U/L, P < 0.001) and it correlated with the severity of neurological status and with mortality. A positive correlation between GGT and creatine kinase (CK) serum levels was also observed (r = 0.47, P < 0.01). On day 10 after CI, normalization of serum GGT values was found. We conclude that GGT serum level increases in CI as a consequence of brain damage and that this increment may be considered as a clinical and prognostic unfavourable index of the disease.

Neurological state, infarct size and clinical outcome are related to early platelet count decrease in stroke

We performed this study in order to verify the existence of a correlation between early platelet count reduction and initial neurological impairment, infarct extension and mortality or clinical outcome in an established ischemic cerebral infarction. The results demonstrate that the platelet consumption and/or accumulation in the infarct area, expressed by circulating platelet decrease, is related to the severity of neurological involvement, infarct size and poor clinical outcome.

[Efficacy of L-thyroxine (L-T4) therapy on the volume of the thyroid gland and nodules in patients with euthyroid nodular goiter (ENG)]

The efficacy of treatment with TSH suppressive doses of L-thyroxine was evaluated by echography in 35 patients with euthyroid nodular goiter. Patients have been subdivided in two groups comparable for sex age and size of the goiter. Sixteen patients were treated for nine months with suppressive doses of thyroxine and nineteen were followed without therapy as control. Patients in treatment were then followed up for additional 9 months without therapy. The mean decrease of thyroid volume at nine months was 25% (27 +/- 10 ml vs 20 +/- 8 ml; p < 0.01). After discontinuation of treatment thyroid volume increased and had returned to base line values after nine months of follow up. In the control group mean thyroid volume had increased by 17.7% at nine months (28 +/- 17 vs 33 +/- 19 ml; p < 0.001). Thyroid nodules in response to thyroid hormone treatment showed a variable behaviour: 30.7% (4/13) of the nodules responded to the therapy with a reduction > to 25% at the ninth month; the remaining nodules were insensitive to the therapy. In conclusion suppressive thyroxine treatment is effective in reducing the goiter, nodules instead are only in part sensitive to the treatment. Thyroxine therapy of euthyroid nodular goiter must be followed for long term since upon thyroxine discontinuation there is a prompt reappearance of the goiter.

Effect of the acute sublingual administration of ketanserin in hypertensive patients

The purpose of this study has been to compare the acute antihypertensive effect of a dose of 20 mg of ketanserin in 18 patients after sublingual administration and in 19 after oral administration. In three patients ketanserin and ketanserin-ol plasma levels were measured after both sublingual and oral administration. The results showed a more rapid, considerable antihypertensive effect after sublingual administration. In addition, the high plasma levels of ketanserin-ol, the metabolite produced by hepatic reduction of ketanserin, reached after sublingual administration, rather than transmucosal absorption, indicate that the clinical effect observed is due to more rapid dissolution of the tablet formulation and liberation of the active drug.

Hypocalcemia and hypomagnesemia in cancer patients

The aim of this study was to evaluate the incidence of hypocalcemia and hypomagnesemia and the relationship between calcium and magnesium serum levels in 82 hospitalized cancer patients, 61 of whom were in the terminal phase of the disease. The frequency of hypocalcemia and hypomagnesemia was 13.4% and 17.1% respectively. The incidence of hypocalcemia in patients with hypomagnesemia was 28.6%, while in those with normal or high magnesium serum levels it was 10.3%. The lowest magnesium serum level was observed in hypocalcemic patients. It may thus be concluded that hypocalcemia and hypomagnesemia are a frequent complication of malignant tumors mostly in the terminal stage of the disease, and that even hypomagnesemia could contribute to the development of tumor-associated hypocalcemia.

[Clinical and prognostic importance of changes in the number of circulating lymphocytes in cerebral infarction of the ischemic type]

Aim of the present study was to assess the increase of peripheral white blood cell (WBC) count and its clinical and prognostic significance in patients with cerebral ischemic infarction (CI). Thirty-six subjects (17 males, 19 females; mean age 73 +/- 10 years) with CI confirmed at CT scans were studied. A significant increase of WBC, not related to complicating infections, was observed in the early phase of CI. There was a significant linear correlation between the level of serum creatine phosphokinase and the number of circulating WBC which were higher in patients who died 6-30 days after the occurrence of CI. These data suggest that the increase in circulating WBC is dependent on the extent of the cerebral damage and should be considered as unfavourable prognostic sign.

Platelet count, mean platelet volume and their relation to prognosis in cerebral infarction

The study was performed on patients with ischaemic cerebral infarction in order to obtain information on serial changes of some platelet parameters and to test their prognostic significance. Platelet count, obtained within 48 h after cerebral infarction, was significantly lower than in the control group (213,611 +/- 65,652 mm-3 vs. 299,525 +/- 60,611 mm-3, P less than 0.001), reaching the normal level on the ninth day and thereafter. The mean platelet volume was significantly greater than in the controls (11.26 +/- 1.29 fl vs. 8.93 +/- 0.93 fl, P less than 0.001), and normalization generally occurred on the forty-fifth day. The mean platelet count was significantly lower in the patients who died than in those who survived (P less than 0.025 and P less than 0.05 respectively on the first to second and fourth day after infarction). The reduction of platelet count and the increase of mean volume appear to be related to an increased platelet consumption in the infarction area, associated with an in vivo platelet activation, as larger platelets are more responsive to platelet activity and aggregability tests. The lower mean platelet count observed in the patients who died suggests that the platelet value might be considered as a prognostic index of cerebral infarction.

[Plasma osteocalcin in children: effects of age, sex and body surface]

The aim of the study was the evaluation of plasma osteocalcin (O.), alkaline phosphatases (A.P.) and urinary hydroxyproline excretion (uOHPr) in subjects 3-20 years aged. O., A.F. and uOHPr were increased in patients less than 15 years aged; thereafter the values were similar to normal adult values. O. correlates with age and body surface area in children aged less than 15 years; the highest values were observed at the expected age of puberal spurt. This behaviour was not evident for the other bone turnover markers studied. In conclusion, it could be suggested that O. is a useful index of bone peak mass reached at puberty.

Pathogenetic aspects of involutional osteoporosis

The pathogenetic factors of postmenopausal and senile osteoporosis are reviewed. Both postmenopausal and senile osteoporosis occur as a result of a defective regulation of bone remodelling which leads to a negative uncoupling between bone resorption and bone formation. Systemic and local factors contribute to the development of the phenomenon. While studies of the systemic factors involved in age-related bone loss are well advanced, although still incomplete, the study of the local factors responsible at a tissue level for the negative skeletal balance has barely begun.

Evaluation of platelet changes in completed ischemic stroke

In a retrospective study we evaluated the platelet count in 45 patients mean age 73 +/- 9 years, with cerebral infarction (C.I.) documented by CT, and 45 age and sex-matched controls randomly selected. In 12 patients changes in platelet count were examined prospectively, starting from the acute event for 30 days. In the retrospective study the mean platelet count in C.I. was significantly lower than that found in controls: 260, 220 +/- 86,076/mm3 and 302, 422 +/- 65,747/mm3 (p less than 0.05) respectively. In the prospective study the mean count was 213,330 +/- 79,930/mm3. A progressive increase up to the 9-12th day was observed, achieving a mean of 305,630 +/- 83,470/mm3 (p less than 0.01), not statistically different from controls. The 40-45% decrease of platelet count shows that about half of the circulating platelets had rapidly disappeared from the systemic circulation, presumably related to an increase in vivo platelet activation and aggregation.

Recurrent hyperparathyroidism: a study of 3 cases with evaluation of some pathogenetic and clinical aspects

Three patients with recurrent hyperparathyroidism (15, 8 and 3 years respectively, after the first operation) are described in order to establish the causes and define the clinical characteristics of the disease. The observation that in the present series recurrent hyperparathyroidism was associated either with an adenoma (two cases) or a carcinoma (one case), appears to stress the possibility of the pathological involvement of one gland even though recurrent hyperparathyroidism should be considered due to the chronic extrinsic stimulation of the parathyroid glands. The severity of the clinical and metabolic picture observed at the time of the first diagnosis and/or at the time of recurrence together with the simultaneous presence of bone and stone disease in the patients described is of particular interest. The cases reported underline the importance of carrying out careful metabolic investigations in patients with hyperparathyroidism not only before but also for a prolonged period of time after operation.

Acute effects of removal of parathyroid adenoma on plasma and urinary hydroxyproline levels

This study was carried out to investigate early effects of parathyroidectomy (PTx) on bone matrix collagen metabolism. Eleven patients suffering from primary hyperparathyroidism were studied by measuring urinary excretion of hydroxyproline (OHPr) and cAMP in samples collected before PTx and, on the day of surgery, at intervals of 1-3 h for the first 10 h and then at longer intervals. In six patients nondialyzable urinary OHPr and free plasma aminoacid levels were also assayed. We found that the average period required for OHPr/Cr ratio and plasma OHPr to reach normal values was longer than the mean time required for cAMP/Cr ratio to reach normal limits. In all patients the total amount of nondialyzable OHPr decreased in the first 24 h after PTx but thereafter a daily increase in the urinary excretion of nondialyzable component was seen, so that the fractional amount of nondialyzable OHPr in the fourth postoperative day (26.8 +/- 5.2 SE) was significantly higher than that of preoperative one (6.1 +/- 1.0; p less than 0.02). Our results confirm that PTx induces a reduction in the rate of bone collagen resorption and indicate that changes of OHPr/Cr ratio and free plasma OHPr values may be considered useful indices of successful parathyroid surgery, even though they lag behind those of cAMP. The different behavior of total and nondialyzable OHPr after surgery indicates that acute deficiency of parathyroid hormone induces a positive uncoupling of the two processes of bone remodeling, thus supporting the view that the acute direct effect of the hormone on bone formation is an inhibition of this process.

[Influence of age and sex on the urinary excretion of total and non-dializable hydroxyproline]

Urinary excretion of total OHPr, an index of bone resorption, was evaluated in 68 normal subjects (25 males and 43 females) aged 19-83 years. In 49 of them non-dialyzable OHPr(ndOHPr), which reflects bone matrix formation, was also determined. Total urinary OHPr, expressed as mg/24 h, significantly decreased with advancing age in both sexes: however by means of multiple regression analysis no correlation was found after correction of OHPr behaviour for changes in creatinine clearance. On the contrary ndOHPr was inversely correlated with age (r = -0,56, p less than 0,001) even when creatinine clearance was held constant (p less than 0,05). The findings obtained seem to show that a decrease in osteogenetic activity is also responsible for the physiological ageing bone loss.

Calcitonin secretion and bone disease severity in hypercalcaemic hyperparathyroidism

Calcitonin (CT) plasma levels and urinary hydroxyproline (OHPr) excretion were studied in twenty-eight patients (eleven males and seventeen females) with primary hyperparathyroidism in order to ascertain the effect of CT secretion on the severity of bone disease. The results show that in primary hyperparathyroidism plasma CT levels are increased in about 50% of patients independent of sex. Plasma CT levels were correlated with serum calcium values in males but not in females. Urinary OHPr excretion values appeared higher in those patients which showed lower CT plasma levels. In this latter group the incidence of undetectable CT plasma values was higher in females. The results suggest that in patients with primary hyperparathyroidism the persistent challenge of CT secreting parafollicular cells due to chronic hypercalcemia, may induce a decrease in their functional reserve, and that the bone involvement may have a greater incidence and more severe course in females, due at least in part, for their inability to increase CT secretion as much as males, due to an intrinsic sex-related lower CT secretory reserve.

Incidence of normocalcemic hyperparathyroidism in idiopathic hypercalciuria: evaluation by dietary calcium deprivation test

Calcium metabolism was studied in 37 patients with "idiopathic hypercalciuria" on a home diet and after 10 days of low calcium dietary intake (less than 400 mg/24h). After low calcium intake, urinary calcium excretion returned to within normal limits in 70% of the cases. In the group of patients which failed to respond to calcium restriction, TmPO4/GFR values were reduced and, furthermore, in 20% of them plasma iPTH and urinary cAMP levels were increased. These data seem to indicate that: the incidence of absorptive hypercalciuria is higher than hypercalciuria of renal origin; normocalcemic hyperparathyroidism due to primary calcium leak is present only in a limited number of cases, consequently, hypercalciuria secondary to renal phosphate leak is a rather frequent occurrence.

[Evaluation of intestinal absorption of calcium by means of double-isotope methods and oral administration of the tracer]

The percent intestinal absorption of calcium was measured in normal volunteers and in patients with idiopathic hypercalciuria employing the deconvolution method, the ratio of the two administered isotopes at equilibrium and the percent of dose present in plasma 2 hr after oral administration of the tracer. Comparison of results obtained showed that the technique based on the ratio between the two radioisotopes overestimates intestinal absorption by about 9% with respect to values calculated with the deconvolution method, but gives results comparable to those determined by oral administration of the isotope. The percent dose of the tracer 2 h after i.v. administration is closely correlated with the size of the miscible calcium pool. A less significant correlation exists between the size of the pool and percent of the dose 2 h after oral administration.

[Values and limitations of the radioimmunological determination of plasma parathyroid hormone in the study of the functional activity of the parathyroid glands]

Aim of the present study was to establish the limits and difficulties prevailing in RIA of PTH due to different specificity of antisera. Studies were carried out on normal volunteers and 36 patients with primary hyperparathyroidism (HPT) employing two different assay techniques a) 211/32 antiserum from Wellcome Lab. and b) Immuno Nuclear Corporation Kit. Plasma iPTH values were higher in most primary HPT patients than in normal subjects with both techniques. It is possible nevertheless to differentiate the primary HPT patients with normal plasma iPTH values from normal subjects by correlating plasma iPTH values with corresponding serum calcium values.

[Studies of the half-life of plasma parathyroid hormone: rate of disappearance of immunoreactive fragments of the hormone after surgical removal of the parathyroid adenoma in primary hyperparathyroidism]

The disappearance rate of immunoreactive plasma parathyroid hormone (iPTH) was studied, employing two different antisera, following removal of parathyroid adenoma in patients with primary hyperparathyroidism. One antisera contained antibodies against both the NH2 region and the COOH terminal of the molecule (antiserum 211/32, Wellcome Laboratories), the other contained antibodies against antigenic sites of the terminal COOH portion (Immuno Nuclear Corporation antiserum). The iPTH plasma level dropped in all patients following removal of the adenoma. The half-life was longer than that of the native hormone and shorter than that of the terminal fragment with both antisera, being 38.8 min for the 211/32 and 32.9 min for the I.N.C. antiserum. Whilst this finding might be expected for the 211/32 antiserum, on account of its characteristics, it is difficult to offer an explanation for the observed half-life of the I.N.C. anti serum which is specific for the terminal COOH region. These results appear to suggest that the terminal COOH fragment may be further metabolized and that its longer half-life, observed by other authors, is due to the antisera used recognizing the antigenic sites in a fragment smaller than the terminal COOH portion of the molecule, rather than to the effective half-life of the entire fragment.

Significance of early increase in stable and radioactive plasma calcium after parathyroidectomy in primary hyperparathyroidism

Early effects of parathyroid hormone (PTH) deficiency were studied in 12 patients with primary hyperparathyroidism due to single parathyroid adenoma by following the precise time course of changes in plasma calcium (Ca) and immunoreactive parathyroid hormone (IPTH) after parathyroid surgery and by prelabeling 2 patients with radiocalcium (Ca*). Surgical removal of the adenoma was immediately followed by a sudden increase in plasma Ca which preceded the usual fall. The increase in plasma Ca commenced simultaneously with the fall in iPTH and was accompanied by a parallel increase in specific activity (sp. act.) of plasma Ca*. Specific activity continued to rise for 2 h in both prelabeled patients, whereas blood calcium was already falling thereafter reaching a markedly low removal rate constant as long as plasma Ca decreased. When plasma Ca began to rise, sp. act. resumed a descending course. Our findings indicate that the initial hypercalemia depends on PTH withdrawal and results from a rapid flux into general extracellular fluid (ECF) of calcium coming from a compartment with higher sp. act., contained within the miscible pool, immediately followed by a reduction in calcium transfer from bone. These results suggest that acute PTH deficiency determines an outflow of calcium from bone cells and support the theory that PTH initiates its action by modifying their intracellular calcium content.

[Effects of the length of radioiodine treatment of hyperthyroidism on the distribution of blood levels of calcium and phosphorus as a function of sex and age]

An evaluation was made of the incidence of hypoparathyroidism after 131I management of hyperthyroidism and of the effect of irradiation on the relation between blood calcium, phosphorus and proteins and age in normal subjects. 356 treated patients and 216 controls were examined. Serum calcium was determined from 2 to 6 yr after treatment. It was found that calcium values decrease with age in males, wherease in women this phenomenon is less marked and, indeed, is no longer apparent over the age of 30. In the normal male, phosphrous also decreases with age, while in females there is a fall until the age of 30-40 yr, followed by a rise. Only 1 subject with a value of 8.45 mg calcium/100 ml was noted in the treated group and there was no significant difference between the means for the two groups, suggesting that parathyroid insufficiency is a virtually non-existent complication of the 131I treatment of hyperthyroidism. The relation between blood calcium and phosphorus and age in the treated group was examined with reference to subjects with normal thyroid function only. In the case of calcium, values were no longer related to age after treatment in males, while phosphorus values fell to below those observed in females, coupled with an increase in function of age as in women, though this itself was not statistically significant. Treatment also suppressed the relation between total blood proteins and age noted in the normal male. None of the parameters considered displayed any significant changes in the treated females. It would thus seem that 131I abolishes the differences in blood calcium and phosphorus mean values and age-linked patterns normally found between males and females.

[Importance of the thyroid gland in calcemic homeostasis during intestinal calcium absorption in man]

The importance of calcitonin (CT) in calcaemic homeostasis has been studied in control subjects and in thyroidectomized patients. After administration per os of a calcium load together with a radioactive tracer, calcaemia increases more markedly in thyroidectomized cases while the radioactivity curve shows no difference between the two groups. Unlike the controls, in patients the absorption-induced calcaemic increment curve coincided with the cumulative intestinal calcium absorption curve evaluated by the biradioisotopic method. Thus absorption-induced hypercalcaemia in athyroid subjects would not seem to be controlled by homeostatic factors. Through CT, the thyroid exerts an evident, though limited, braking action on calcaemic increase due to absorption. Considering that absorption of calcium is prolonged for a number of hours, CT secretion will last at least as long as will its action on the skeleton. The saving of skeletal mineral that follows may be considered to be physiologically more important than the effect of the hormone on calcaemic homeostasis.