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Biomedical subjects

C Gennari

Publications and source records attributed to C Gennari.

At least 217 records · Page 12Linked to original sources
PubMed1980

Effects of parathyroid hormone and calcitonin on plasma and nephrogenous cyclic adenosine-3',5'-monophosphate in normal subjects and in pathological conditions.

To evaluate the response of bone cells and kidney to parathyroid hormone (PTH) and calcitonin (CT), the acute effects of these hormones given intravenously on plasma cyclic adenosine 3',5'-monophosphate (cAMP), nephrogenous cAMP and clearance ratio (cAMP:creatinine), have been studied in normal subjects and in patients with Paget's disease, hypoparathyroidism and osteopetrosis. Twenty-five subjects were given bovine synthetic PTH, thirty-eight calcitonin (sixteen salmon, eighteen human and four porcine CT). In normal subjects and in patients with Paget's disease and hypoparathyroidism plasma cAMP increased within 1 h following PTH intravenous infusion. The same dose of PTH failed to produce any increase in plasma cAMP level in two children with marble bone disease. Nephrogenous cAMP increased in all cases. A different relative potency of calcitonins in increasing plasma cAMP has been observed in normal subjects, according to previous results on the plasma calcium lowering effect. Paget's disease patients showed a greater increase in plasma cAMP following infusion than normal subjects. The measurement of nephrogenous cAMP and the clearance ratio (cAMP: creatinine) demonstrated a minor involvement of the kidney in the production of cAMP after CT infusion; the late increase observed in nephrogenous cAMP was probably due to a parathyroid rebound following the hypocalcemic effect of CT.

Adult↗
PubMed1978

Prostaglandin PGE2: a possible mechanism for bone destruction in calcinosis circumscripta.

A patient showed evident osteolysis in phalanges and heavy periarticular calcium deposits of the fingers, wrists and toes which avidly took up 47Ca. The dense, white, tooth-paste like fluid contained in the periarticular calcium deposits has been studied by two different X-ray diffraction methods, by Ubatuba's bioassay for prostaglandin, by thin layer chromatography and by mass spectrometry. The calcium deposits were hydroxyapatite and prostaglandin PGE2 was detected in them. The bone resorption stimulating activity of PGE2 would be expected to result in increased bone destruction with release of calcium salts and this could be a working hypothesis of the pathogenesis of calcinosis circumscripta.

Calcinosis↗
PubMed1978

Urinary excretion of cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate in malignancy.

The urinary excretion of cyclic adenosine 3',5'-monophosphate (cAMP), corrected for urinary creatinine, was determined in 177 patients with primary or metastatic tumours and in 149 normal subjects. In 26 patients with malignancy and in 10 control subjects the excretion of cyclic guanosine 3',5'-monophosphate (cGMP) was also evaluated. The urinary cAMP/Cr ratio in human neoplasms of epithelial origin was often significantly lower than normal, irrespective of the extension of malignancy. Surgical resection of the tumour, radiotherapy, or theophylline treatment increased urinary excretion of the nucleotide. In patients with malignancy, intravenous infusion of glucagon failed to produce the degree of elevation of plasma cAMP seen in normal subjects. Urines from patients with malignant neoplasms had low values of cAMP/Cr ratio with increased values of cGMP/Cr ratio. These findings could be the result of systemic alteration in synthesis or breakdown of the nucleotides.

Adult↗
PubMed1977

Effects of a new glucocorticoid, oxazacort, on some variables connected with bone metabolism in man: a comparison with prednisone.

The urinary elimination of calcium, other electrolytes, and hydroxyproline and the oral absorption of 47Ca have been evaluated in three groups of 8 patients before and during a 15-day treatment with prednisone at daily doses of 25 and 50 mg and with oxazacort, a new glucocorticoid, at a daily dose of 50 mg. The results obtained demonstrate that oxazacort in short-term teatment with a high dose has no significant effect on the urinary elimination of calcium and hydroxypyroline in experimental conditions in which prednisone produces statistically significant and clinically relevant increase, both when given at the same dose and when given at half that dose. On the other hand, the oral absorption of 47Ca is decreased by oxazacort, but less than by prednisone at the same dose. As the antirheumatic activity of oxazacort appears to be only slightly lower than that of prednisone (activity ratio of about 0.84: 1), these findings may have interesting therapeutic implications.

Adult↗
PubMed1976

[Methods for measuring the intestinal absorption of calcium in humans (author's transl)].

For the determination of intestinal absorption of calcium, the fasting (12 hours) patient receives radioactive labeled calcium (45Ca, more frequently 47Ca) by mouth. After 10, 20, 30, 60, 90, 120, 180 and 240 min, samples of venous blood are taken. The stool is also collected for three days. The determination of radiocalcium in the plasma and in the stool samples is done with a Geiger counter. This oral test provides informative results on numerous aspects of the pathophysiology of intestinal assimilation of calcium. In humans, the duodenum seems to be of the greatest importance for calcium absorption.

Administration, Oral↗
PubMed1976

[Intestinal absorption of radiocalcium after long-term treatment with sodium fluoride in senile osteoporpsis].

Prolonged administration of sodium fluoride (NaF) in patients suffering from osteoporosis or Paget's disease leads to a positive calcium balance together with positivization of the calcium balance may mean an ins, intestinal absorption of calcium was evaluated directly with the oral rrotic patients; 6 months treatment with NaF led to a significant imprt is difficult to say how this finding is connected with the drug's actide apatite crystals; the crystals' greater stability probably leads to greater resistance of fluorated bone to the action of parathormone, thus bring on hypocalcaemia which homeostatically stimulates parathyroid hyperiirect pointer to parathyroid hyperincretion. The therapeutic effectiveness of NaF in diffuse decalcifying osteopathies is, however, limited by the drug's toxicity.

Age Factors↗