Search PubMed⌕ Search

Biomedical subjects

S Gaspar

Publications and source records attributed to S Gaspar.

At least 37 records · Page 2Linked to original sources
PubMed1983

[In vitro incorporation of radioactive sulfur into proteoglycans of cartilage. Effects of various nonsteroidal anti-inflammatory agents].

Radioactive sulphur (35SO4) is incorporated in the proteoglycans of chicken embryonic cartilage. In fact, the molecular weight of the macromolecules which bind the sulphur corresponds to monomeric proteoglycans and proteoglycan-hyaluronic acid complexes. This incorporation does not take place when the cartilage has been previously killed. The capture of 35S is stimulated by human serum, in a dose-dependent way. At doses less then, equal to and greater than the maximal plasma concentrations observed following a single oral dose (600 mg), acetyl salicylic acid and sodium salicylate inhibit the incorporation of radioactive sulphur in the cartilage. Under the same conditions, tiaprofenic acid and oxametacine have no effect on this metabolic parameter.

Animals↗
PubMed1981

Responses to salmon calcitonin in chronic renal failure: relation to histological and biochemical indices of bone turnover.

Twenty-one patients with chronic renal failure and bone disease or hypercalcaemia were studied before and following single (twenty patients) or repeated (fourteen patients) intravenous injection of synthetic salmon calcitonin. Significant correlations were noted before treatment between bone surfaces occupied by osteoblasts or osteoclasts and plasma levels of immunoreactive parathyroid hormone, alkaline phosphatase and hydroxyproline. Following a single injection of 2--200 i.u. salmon calcitonin, plasma levels of calcium and phosphate fell for 6--8 h, but rose subsequently to pre-injection levels at 24 h. The magnitude and duration of the hypocalcaemic response was not clearly dose-dependent, but correlated with measured indices of bone cell activity. Repeated administration of calcitonin (10--200 i.u. thrice weekly for up to 2 months) lowered plasma calcium in the majority of patients and restored plasma calcium to normal in four previously hypercalcaemic patients. Mean levels of alkaline phosphatase increased but no significant changes in plasma phosphate, immunoreactive parathyroid hormone and calcitonin, or hydroxyproline occurred. Calcium absorption (six studies) did not change during treatment. We conclude that synthetic salmon calcitonin is an effective short-term inhibitor of bone resorption in patients with chronic renal failure. Its use as a possible treatment for hypercalcaemia and hyperparathyroid bone disease in chronic renal failure is discussed.

Adult↗
PubMed1981

Lack of clinical and physiological relationship between gastrin and calcitonin in man.

The clinical and physiological relevance of the relationship between gastrin and calcitonin has been investigated in normal subjects and in patients suffering from gastritis or duodenal ulcer. Basal plasma levels of calcitonin are increased in these patients but there is no significant relationship between calcitonin and gastrin levels. Acute pentagastrin injection in normal male subjects increased significantly (P less than 0.05) plasma calcitonin levels whereas lower doses of pentagastrin which are known to stimulate gastric secretion are without effect on calcitonin levels. Moreover, stimulation of gastrin secretion by a protein test meal and by intragastric administration of a calcium chloride solution is not followed by any significant increase of plasma calcitonin levels. These results suggest that the stimulation of calcitonin secretion by gastrin and its synthetic analogue pentagastrin is a pharmacological rather than a physiological phenomenon.

Adult↗
PubMed1981

Comparison of acute effects of 1.25- and 24.25-dihydroxy-vitamin D3 in normal subjects.

Effects of small iv doses of 1.25-dihydroxy- and 24.25-dihydroxy-vitamin D3 (a microgram) were studied in 10 normal subjects. Injection of 1.25 (OH)2D3 was associated with small but significant increases in plasma calcium and phosphate but plasma levels of immunoreactive parathyroid hormone (iPTH) and calcitonin (iCT) did not change. The administration of 24.25 (OH)2D3 was associated with comparable decreases in plasma calcium and a small and transient decrease in plasma iPTH. Plasma levels of iCT did not change. 24.25 (OH)2D3 also significantly increased glomerular filtration rate and decreased the urinary excretion of noradrenaline, in contrast to 1.25 (OH)2D3 which had no effect on these variables. The rapid infusion of calcium significantly decreased levels of iPTH. We conclude that small doses of 1.25 (OH)2D3 and 24.25 (OH)2D3 have little, if any, direct effect on the secretion of PTH and CT in man.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

[Radioimmunoassay for type II amino-terminal procollagen peptide. Technical note].

We have studied the immunoreactivity of human sera and synovial fluids in a radioimmunoassay which utilizes an anti-bovine procollagen type III antiserum and the bovine type III procollagen peptide as standard and tracer. We have noticed a complete cross reaction between bovine col 1-3 and human synovial fluid, which thus contains substance (s) having the same antigenic determinant (s) as col 1-3. On the contrary, we have demonstrated non parallelism between col 1-3 and human serum, whether the serum was obtained from normal subjects or patients suffering from various diseases. These results suggest that immunoreactive substances related to col 1-3 and detected in sera are at least partially different from those detected in synovial fluids.

Animals↗
PubMed1980

[Demonstration of multiple forms of immunoreactive calcitonin (CTi) in human serum by isotachophoresis. Preliminary results].

Heterogeneity of immunoreactive calcitonin (iCT) in the serum has been studied by preparative isotachophoresis. Under the described technical conditions, it is possible to distinguish several molecular species of iCT characterized by a faster mobility than synthetic CT. Preliminary results suggest that immunoreactive CT profile is not similar in various hypercalcitonemic diseases.

Calcitonin↗
PubMed1979

Ethanol induced secretion of calcitonin in chronic renal disease.

Whisky (25-50 ml) increased plasma levels of immunoreactive calcitonin (iCT) in seventeen of nineteen patients with chronic renal failure. The effect was greater in patients with high levels of iCT than in those with normal levels. Changes in plasma iCT were not related to changes in calcium, phosphate or immunoreactive gastrin, but were inhibited by the prior administration of propranolol.

Calcitonin↗
PubMed1979

[The effects of 1 alphahydroxycholecalciferol in patients with renal osteodystrophy, Paget's disease of bone and in normal subjects (author's transl)].

The administration of 1 alpha hydroxycholecalciferol (1 alpha OHD3) (2 microgr. per day) increase the plasma immunoreactive calcitonin (i CT) concentration in normal subjects after six days. This effect is also observed in patients suffering from Paget's disease of bone, suggesting that the mechanism responsable for the secretion of CT following the administration of 1 alpha is not disturbed in that disease. By contrast, the absence of increase in plasma iCT in the patients suffering from chronic renal failure suggests an impaired secretion of CT in that disorder.

Calcitonin↗
PubMed1977

Changes in histologic and biochemical indexes of bone turnover after bilateral nephrectomy in patients on hemodialysis. Evidence for a possible role of endogenous calcitonin.

We studied the effects of bilateral nephrectomy on bone metabolism in 27 patients on maintenance hemodialysis. After nephrectomy plasma alkaline phosphatase fell rapidly in 10 patients whose preoperative plasma levels had been higher than normal. This fall was associated with a transient decrease in osteoblast counts of iliac-bone biopsies. A fall in plasma phosphate and a rise in plasma immunoreactive calcitonin also occurred, but calcium and immunoreactive parathyroid hormone levels did not change. Alkaline phosphatase levels remained unchanged in a control group of 17 patients on dialysis who had undergone an operation other than nephrectomy. In 26 nonsurgical patients on dialysis, immunoreactive calcitonin was inversely related to osteoblast counts. Rises in immunoreactive calcitonin may be partly responsible for the transient decreases in bone turnover after bilateral nephrectomy. Low levels of endogenous calcitonin may allow an increase in bone turnover in chronic renal failure.

Adolescent↗
PubMed1977

Synthesis and release of gonadotropins and their subunits by long-term organ cultures of human fetal hypophyses.

From weeks 13 to 26 of fetal life human hypophyses disclosed a constant content of radioimmunoassayable FSH. Although present already before this period, LH content increased considerably at week 17, along with the appearance of free beta-LH. In long-term organ culture experiments such early differentiating pituitaries proved to be endowed with autonomous synthesis and release of FSH and of free alpha-subunit, while LH, beta-LH and TSH declined to very low levels within a few weeks. Supplementation of the medium with LH-RH (12 ng/ml) significantly increased FSH synthesis and release but was not sufficient to sustain production of beta-LH and LH. It is suggested that other factors than LH-RH are required for differentiation of beta-LH biosynthesis and thus for production of LH.

Animals↗
PubMed1977

[Blood calcitonin in alcoholic cirrhosis].

In spite of an important metabolic role of the liver in the synthesis and degradation of hormonal peptides and seco-steroïds, the clinical occurrence of disturbed regulation of calcium and phosphorus metabolism is rare in hepatic disorders. 23 patients suffering from alcoholic cirrhosis were studied. All had normal plasma calcium and phosphorus concentration as well as immunoreactive parathyroid hormone levels. 25 hydroxyvitamin D3 levels were decreased. Immunoreactive calcitonin were increased in relation to the increase in plasma alkaline phosphatase activity. The causes and consequences of these endocrine disturbances are discussed.

Calcitonin↗