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Biomedical subjects

G F Mazzuoli

Publications and source records attributed to G F Mazzuoli.

At least 37 records · Page 2Linked to original sources
PubMed1991

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.

Aged↗
PubMed1991

Clinical usefulness of serum tartrate-resistant acid phosphatase activity determination to evaluate bone turnover.

The study was carried out to evaluate the clinical validity and usefulness of serum tartrate-resistant acid phosphatase (TRAP) activity determined using an improved spectrophotometric assay. Enzyme activity was measured in 84 normal subjects and in 109 patients with common metabolic bone diseases. Mean values of serum TRAP activity in male subjects (n = 19; 10.4 +/- 2.15 U l-1) were not significantly different from those found in female subjects (n = 65; 10.8 +/- 1.8 U l-1). In the latter group mean values were significantly raised in post-menopausal subjects (10.5 +/- 2.0 U l-1; p less than 0.01) compared with mean values in pre-menopausal women (8.45 +/- 1.8 U l-1). We found a significant inverse correlation between serum TRAP activity values and bone mineral density (BMD) measured both at an ultradistal radial point (n = 33, r = -0.506; p less than 0.01), and at the lumbar spine (n = 57, r = -0.261; p less than 0.05). Mean serum TRAP activity values in patients with metabolic bone diseases were: primary hyperparathyroidism, n = 30: 14.2 +/- 4.89 U l-1, p less than 0.001 vs normal subjects; chronic maintenance haemodialysis, n = 19: 17.4 +/- 6.7, p less than 0.001; metastatic cancer, n = 13: 21.2 +/- 6.3, p less than 0.001; post-surgical hypoparathyroidism, n = 10: 9.9 +/- 1.8, NS; involutional osteoporosis, n = 20: 12.5 +/- 2.3 p less than 0.001; Paget's disease, n = 10: 16.8 +/- 3.5, p less than 0.001; osteomalacia, n = 7: 19.5 +/- 3.31, p less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1990

Effects of salmon calcitonin on the bone loss induced by ovariectomy.

We present the results of a 12-month clinical study assessing the effects of synthetic salmon calcitonin (sCT) on a group of fertile white women who had undergone ovariectomy for uterine fibromatosis. The study was performed to verify whether CT can prevent the loss of bone mass and the changes in calcium-phosphorus metabolism associated with acute estrogen deficiency. The study consisted of an initial double-blind phase of 6 months, followed by a 6-month open period. Treated patients were given 100 MRC U of synthetic salmon CT injected i.m. in the morning, every other day, starting on the 7th day after the operation and continued for 12 months. Control patients received a placebo injection for the first 6 months; subsequently, they too were treated with sCT i.m. every other day for 6 months at the same dose as the 12 month-treated group. All patients received 500 mg of elementary calcium p.o., b.i.d. Bone mineral content (BMC) was measured at the extreme distal radius of the nondominant arm by a dual photon bone densitometer which utilizes two radio nuclides, 241 Am and 125 I, with energies of about 60 and 30 KeV. Biochemical parameters of the calcium-phosphorus metabolism were also measured. After 12 months of study, no significant changes of BMC were observed in the 12 months sCT treated group, while control patients, treated 6 months after the ovariectomy, showed a significant decrease in BMC values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Acute hypocalcemia enhances prolactin levels: a study before and after oophorectomy.

The effect of acute hypocalcemia on serum prolactin values was investigated in 13 female subjects before and after oophorectomy. An infusion of disodium-EDTA (50 mg/kg b.w., for 120 min) was administered to each patient. Ionized calcium, immunoreactive parathyroid hormone and prolactin serum levels were determined 15 min prior to the infusion, at the beginning of each infusion and thereafter at every 30 min interval. The decrease in serum ionized calcium induced by Na2-EDTA infusion was not influenced by surgery. Serum prolactin and parathyroid hormone values before and after oophorectomy showed a significant (p less than 0.01) increase at 90 and 120 min. The maximum serum prolactin increase was achieved at 120 min and was not influenced by oophorectomy. The results demonstrate that acute hypocalcemia increases serum prolactin levels in female subjects and suggest a possible role for parathyroid hormone and dopaminergic system, even if their interaction remains speculative.

Adult↗
PubMed1990

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.

Aged↗
PubMed1989

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.

Adult↗
PubMed1989

Clinical value of the measurement of bone remodelling markers in primary hyperparathyroidism.

This study was performed in order to evaluate the clinical usefulness of the measurement of total serum alkaline phosphatase activity (AP), serum osteocalcin (BGP) and urinary hydroxyproline (OHPr) in assessing bone remodelling in primary hyperparathyroidism. Thirty-two patients with primary hyperparathyroidism were included in the study. No statistically significant differences were observed between the mean values of Z-scores obtained for each marker. Furthermore, an inverse correlation was found between percentage of bone mineral content at the distal radius and both BGP (r = -0.57; p less than 0.05) and AP (r = -0.49; p less than 0.05). The results obtained demonstrate that, contrary to other metabolic bone diseases (e.g. Paget's disease of bone), all three markers examined may be used in clinical practice to evaluate the entity of skeletal turnover in primary hyperparathyroidism.

Adult↗
PubMed1988

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.

Aged↗
PubMed1987

Normal calcitonin secretion in acromegaly.

Calcium and phosphate metabolism has been studied in eight patients with active acromegaly. Plasma calcium, phosphate, alkaline phosphatase, creatinine and parathyroid hormone levels were in the normal range in all patients, while urinary calcium excretion, calcium/creatinine ratio and hydroxyproline were higher than in controls (p less than 0.01, p less than 0.01, p less than 0.02, respectively). Basal plasma calcitonin levels were in the normal range and stimulation with calcium (3 mg/kg body weight in 10 min) showed similar calcitonin responses in acromegalic and normal subjects. Our data show that in normocalcemic acromegaly with high bone turnover calcitonin secretion is not abnormal.

Acromegaly↗
PubMed1986

Effects of salmon calcitonin in postmenopausal osteoporosis: a controlled double-blind clinical study.

In this paper we present the results of a 12-month double-blind clinical multicenter study assessing the effects of synthetic salmon calcitonin (CT) administration in a group of white postmenopausal osteoporotic women. Treated patients were given 100 MRC units of synthetic salmon CT injected i.m. in the morning every other day. Control patients received a placebo injection. All patients received 500 mg of elementary calcium p.o., b.i.d. Bone mineral content (BMC) was measured at the extreme distal radius of the nondominant arm by a dual photon bone densitometer which utilizes two radionuclides, 241Am and 125I, with energies of about 60 keV and 30 keV respectively. Biochemical parameters of calcium-phosphorus metabolism were also measured. After 12 months of treatment a significant mean increment of BMC and nondialyzable OHPr/creatinine values and a significant decrease of total OHPr/creatinine values were observed in the treated group, while controls showed a significant decrease in BMC values. These results, together with the observation that in some patients the decrease in total OHPr/creatinine values was not accompanied by an increment of BMC, show that long-term salmon CT treatment may be of benefit in postmenopausal osteoporosis and that the effects of CT on bone mass may be due not only to the inhibition of bone resorption but also to the stimulation of bone formation.

Aged↗
PubMed1986

Basal and stimulated calcitonin secretion in primary hyperparathyroidism before and after parathyroidectomy.

To investigate calcitonin secretion in primary hyperparathyroidism, basal and stimulated (3 mg Ca++/kg body weight/10 min) immunoreactive calcitonin plasma levels were studied before parathyroidectomy. Plasma calcitonin levels were raised in 50% of patients regardless of sex, but a significant correlation between basal plasma calcium and calcitonin was found only in males. A reduced calcitonin response to calcium infusion was observed in all patients. Parathyroidectomy invariably induced a normalization of calcitonin basal levels. Our findings confirm the existence of a decreased parafollicular cell reserve probably as a consequence of the persistent hypercalcemic state in hyperparathyroid patients and suggest that it is more frequent in females.

Adult↗
PubMed1984

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.

Adenoma↗
PubMed1983

[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.

Adult↗
PubMed1981

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.

Adolescent↗
PubMed1981

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.

Calcium↗
PubMed1979

[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.

Administration, Oral↗