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Biomedical subjects

S Gaspar

Publications and source records attributed to S Gaspar.

At least 19 recordsLinked to original sources
PubMed1992

Endogenous production of specific antibodies does not decrease hypocalcemic response to calcitonin in young rabbits.

In order to evaluate the potential inhibition of the acute anti-osteoclastic activity of salmon calcitonin (SCT) by specific antibodies (Ab), we compared the SCT-induced hypocalcemic effect in young male rabbits with significant titers of high affinity Ab and in matched animals without Ab. Immunization of rabbits was performed by repetitive s.c. injections of SCT and Freund adjuvant. Ab were present in four-fifths of SCT-treated rabbits (Ab+). Their titer varied from 0.8 x 10(-9) to 30 x 10(-9) M/liter and their constant of affinity from 0.97 x 10(9) to 4.2 x 10(9) L/M. Intravenous injection of 1 IU/kg SCT to Ab+ rabbits induced a significant decrease (P less than 0.01) of ionized serum calcium (Ca2+) after 30 minutes (mean +/- SD: -9 +/- 0.6%) and until the 240th minute of the test (-16.7 +/- 4.7%), with a maximum after 120 minutes (-22.6 +/- 2%). This was not significantly different from the hypocalcemic effect measured after the same procedure performed in matched animals without Ab (Ab-): significant decrease in Ca2+ (P less than 0.01) after 30 minutes (-8.2 +/- 2.2%), maximal after 150 minutes (-23.2 +/- 4.9%), and lasting until 210 minutes (-14.5 +/- 3.7%). We conclude that, in the particular model of the male young rabbit, specific anti-SCT Ab do not block or reduce the acute anti-osteoclastic activity of SCT.

Animals↗
PubMed1989

Study of the formation of prechondral blastemas in the autopodium of normal and polydactyl rats.

The nuclear volume fractions in chosen mesenchymal and prechondral zones were examined during formation of the prechondral rays in the autopodium of 14- and 15-day rat embryos. A morphometric analysis showed that formation of the prechondral blastemas was accompanied by a significant increase in the nuclear volume fraction in relation to the adjacent distal mesenchyme in both normodactyl and polydactyl embryos. The mean nuclear volume fraction in the prechondral blastema (the third metatarsal ray) is somewhat larger in normodactyl embryos, but the differences (in progressive means) are not statistically significant. The nuclear volume fractions at chosen sites in the mesenchymal zones at 14 and 15 days do not differ significantly in either normodactyl or polydactyl embryos. There are, however, significant differences between the nuclear volume fractions of the mesenchymal cells at the chosen sites in normodactyl and polydactyl embryos at both 14 and 15 days. The degree of enlargement of the nuclear volume fraction in the prechondral (chondrogenic) ray in relation to the mesenchyme is relatively greater in polydactyl embryos than in normodactyl embryos.

Animals↗
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↗
PubMedDate not supplied

Electroclinical correlations in temporal lobe epilepsy.

2,698 epileptic patients were studied, 2,019 cases (64.3%) presenting temporal lobe epileptic attacks. Besides the routine EEG recordings and the corroboration of the clinical data with the meticulous observations by video monitoring on a closed circuit TV-screen (the patients being observe in a specially arranged room, provided with infra-red cameras), the diagnostic procedure was supported in all cases by several computerized EEG mappings, according to a model achieved by us, transcribing the primary data obtained by Hjorth's NSD parameters from the Siemens-Elema Mingograph to a Romanian M-118 microprocessor. In many cases we utilized an interface--built by us--for analog-digital conversion which allowed the direct introduction and conversion of amplitudes and frequencies from the Mingograph to the micro-computer. These were isolated to analyse the following electroclinical forms: 1. temporal absences: 360 cases (17.8%); 2. psychomotor attacks: 439 cases (21.7%) 3. psychosensory attacks: 77 cases (3.8%); 4. attacks with cognitive symptomatology: 260 cases (12.8%); 5. crises with ideative-affective symptomatology: 76 cases (3.8%); 6. vegetative attacks: 51 cases (2.5%); 7. akinetic attacks: 89 cases (4.4%); 8. focal temporal attacks secondarily generalized: 667 cases (33.0%). In 112 patients with nocturnal attacks, polysomnographic recordings were performed with sequential computerized EEG mappings during the various stages of sleep (concomitantly with the infrared video-TV monitoring).

Adult↗