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Biomedical subjects

M Peracchi

Publications and source records attributed to M Peracchi.

At least 55 records · Page 3Linked to original sources

Plasma cyclic nucleotide levels in patients with homozygous beta-thalassaemia.

To investigate the possibility that a proliferative non-neoplastic process influences extracellular cyclic nucleotide concentrations, we measured plasma cyclic AMP and cyclic GMP levels in 38 patients with homozygous beta-thalassaemia. This group consisted of 20 patients with thalassaemia major transfused regularly (mean pre transfusion Hb levels, 11 g/dl), and 18 patients with thalassaemia intermedia who did not require regular blood transfusion (mean Hb levels, 8.7 g/dl). In the patient group, plasma cyclic AMP levels were similar to those of 37 normal subjects matched for age and sex, whereas plasma cyclic GMP levels were markedly higher. Moreover, in the thalassaemic patients there was a significant negative correlation between plasma cyclic GMP levels and haemoglobin concentrations, suggesting that their marked erythroid hyperplasia may play a role in determining alterations in extracellular cyclic GMP levels.

Adolescent↗

Plasma cyclic nucleotide levels in monitoring acute leukemia patients.

To verify the clinical usefulness of plasma cyclic nucleotide determination as a tumor marker, levels were measured in 52 normal subjects and in 106 acute leukemia patients. In untreated patients plasma cyclic GMP (cGMP) levels were markedly elevated, whereas cyclic AMP levels did not significantly differ from those of normal subjects. Plasma cGMP levels normalized in all patients who attained complete remission and remained in the normal range during all the remission period. In the patients who relapsed, an early increase in cGMP levels to the pretreatment values was observed, thus suggesting that their determination may be of clinical relevance in monitoring the patients' response to treatment.

Acute Disease↗

Plasma and urine cyclic nucleotide levels in patients with neoplastic diseases.

Plasma and/or urine cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) levels were measured in 67 normal subjects, 55 patients with nonneoplastic diseases, and 324 patients with ten different types of cancer. There were no significant differences in plasma and urine cyclic nucleotide levels between normal subjects and patients with non-neoplastic diseases. In untreated cancer patients, plasma and urine cAMP levels were similar to those of normal subjects, whereas plasma and urine cGMP levels were markedly higher. This pattern was common to all the cancer groups studied. Chemotherapy per se did not seem to influence cyclic nucleotide levels in cancer patients. However, plasma and urine cGMP levels normalized in all patients who attained complete remission. Moreover, in acute leukemia patients who relapsed, plasma cGMP levels increased significantly with respect to the complete remission values, thus suggesting that this parameter may be useful in monitoring the response of cancer patients to treatment.

Adolescent↗

Uptake of 75Se-selenocholesterol by an adrenal cortical carcinoma and its metastases.

Adrenal scintigraphy with 75Se-selenocholesterol was performed in a patient with Cushing's syndrome due to a right adrenal tumor. The tumor was faintly but clearly imaged. The liver was sharply imaged and the liver uptake did not reveal the usual decrease after the first week postinjection. The liver image was still clearly evident in the last scintiphotos taken 26 days after injection of radiocholesterol. At operation a right adrenocortical carcinoma was removed and the right lobe of the liver was found to be almost completely replaced by metastatic adrenal tissue.

Adrenal Cortex Neoplasms↗

Plasma and urine cyclic nucleotide levels in patients with hyperthyroidism and hypothyroidism.

Plasma levels and 24-h urinary excretion of cyclic AMP and cyclic GMP were measured in 18 patients with hyperthyroidism, 7 patients with hypothyroidism and 25 normal subjects. Mean plasma and urinary levels of both cyclic AMP and cyclic GMP were significantly positive correlations between the serum thyroid hormone levels and plasma and urinary cyclic nucleotide concentrations were also found, suggesting that the elevated extracellular cyclic nucleotide levels in hyperthyroidism are probably a consequence of increased secretion of thyroid hormones. In the hypothyroid patients the extracellular cyclic nucleotide concentrations did not differ significantly from those of the normal subjects.

Adolescent↗

Plasma and urine cyclic nucleotide levels in patients with acute and chronic leukemia.

Plasma and urine levels of cyclic adenosine 3',5'-monophosphate (cAMP) and of cyclic guanosine 3',5'-monophosphate (cGMP) were measured in 35 normal subjects, in 24 patients with nonneoplastic diseases (iron deficiency anemia, peptic ulcer, and cholelithiasis), and in 50 leukemic patients. The leukemic group included patients with acute lymphoblastic leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, and chronic myelogenous leukemia. All patients were recently diagnosed and untreated, except for 5 patients with blastic transformation of chronic myelogenous leukemia who had been previously treated. There were no significant differences in plasma and urine cyclic nucleotide levels between normal subjects and patients with nonneoplastic diseases. In leukemic patients, plasma and urine cAMP levels were similar to those of normal subjects, whereas plasma and urine cGMP levels were markedly elevated. There were no significant differences in cGMP values between the various types of leukemia. After starting treatment, plasma cyclic nucleotide levels were periodically measured in 21 of the patients with acute leukemia; cGMP levels were normalized in all the 16 subjects who attained complete remission, whereas both cAMP and cGMP levels were apparently unaffected in the patients who did not respond to treatment. This suggests that plasma or urine cGMP could be used as an additional parameter to monitor the patient's response to treatment.

Acute Disease↗

Patterns of cyclic nucleotides in normal and leukaemic human leucocytes.

Because recent observations indicate that metabolism of cyclic nucleotides may be altered in neoplastic cells, the intracellular levels of cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP) were measured in mononuclear leukaemic and normal human leucocytes. The activities of adenylate cyclase, guanylate cyclase and cyclic nucleotide phosphodiesterases were also determined. Under basal conditions, cAMP levels were always higher in the normal leucocytes, whilst cGMP levels were of the same order of magnitude in both normal and leukaemic cells, causing the cAMP/cGMP ratios to be significantly lower in leukaemic leucocytes. Leukaemic cells significantly increased cyclic nucleotide levels in response to theophylline, but did not respond to serotonin, carbamylcholine or D,L-isoproterenol. Preincubation of these leucocytes with theophylline produced a detectable cAMP response to D,L-isoproterenol but no cGMP response to serotonin or carbamylcholine was found. Adenylate cyclase and guanylate cyclase were significantly lower in leukaemic than in normal cells, which could largely explain the abnormal cyclic nucleotide pattern found in human leukaemic leucocytes. In our experiments, cAMP phosphodiesterase activity was comparable in normal and leukaemic cells, whereas cGMP phosphodiesterase activity was undetectable inall mononuclear-leucocyte preparations with the methods used.

3',5'-Cyclic-AMP Phosphodiesterases↗

Effect of dopamine infusion on serum prolactin concentration in normal and hyperprolactinaemic subjects.

The serum prolactin response to intravenous dopamine infusion (5 micrograms . kg-1 . min-1) was measured in twenty-one healthy subjects, in seven hyperprolactinaemic patients without evidence of a pituitary tumour, and in twenty-one patients with prolactinomas. Mean serum prolactin values were significantly suppressed in all three groups, without any significant difference between the degree of suppression. A decrease of serum prolactin to below 50% of basal values occurred in fifteen healthy subjects, in four patients without evidence of pituitary tumour, and in fourteen patients with prolactinomas. These findings demonstrate that most human prolactin-secreting pituitary adenomas are normally suppressible by exogenously administered dopamine and that dopamine infusion is not able to distinguish between tumorous and non-tumorous hyperprolactinaemia. Since intravenously infused dopamine is believed to inhibit prolactin secretion by acting at pituitary level, it is suggested that a normal functioning of pituitary dopamine receptors is maintained in most human prolactinomas.

Adenoma↗

Plasma immunoreactive N-terminal parathyroid hormone and cyclic AMP and cyclic GMP urinary levels in man after I. M. administration of two different doses of porcine calcitonin.

The effects of acute porcine calcitonin (pCT) administration were studied in 11 healthy volunteers with no metabolic disease. Each subject was given, intramuscularly, 1 MRC unit of pCT in glycine vehicle, 160 units of pCT in gelatine vehicle, and placebo, according to a crossover design. The following parameters were studied: blood calcium, phosphorus and immunoreactive parathyroid hormone (iPTH); urine calcium, phosphorus, cyclic AMP and GMP. Both the pCT preparations produced, at the same time after administration, a hypocalcemic effect (P less than 0.01) which was not dose related, without any modification of urinary calcium excretion, implying that both doses are able to inhibit completely bone destruction. Despite the blood calcium decrease, no significant modifications in plasma iPTH levels were observed. pCT administration did not modify the urinary excretion of cyclic AMP, while it increased the urinary levels of cyclic GMP, particularly at the higher dose employed. Blood phosphorus decrease and urinary phosphate excretion increase were observed only after the administration of 160 MRC units of pCT. These observations suggest that the effects on urinary cyclic GMP and on blood and urine phosphorus are not mediated by PTH but could be the result of a direct action of calcitonin seen only when high doses are employed. In conclusion, one MRC unit of pCT is sufficient to inhibit bone resorption.

Adult↗

Antiserotonin treatment of hyperprolactinemic amenorrhea: long-term follow-up with metergoline, methysergide, and cyproheptadine.

Twenty patients affected by hyperprolactinemic amenorrhea-galactorrhea have been treated with one or more of the following serotonin antagonists: metergoline, methysergide, and cyproheptadine. Among the 11 patients without evidence of pituitary tumor resumption of menses was observed in five, two of whom had ovulatory cycles; one patient became pregnant; ovulations occurred only during treatment with metergoline. In the group of nine patients with enlarged sellae, three experienced isolated episodes of bleeding, while two had three and four menses each, respectively; all cycles were anovulatory. Plasma prolactin levels and galactorrhea were favorably affected by treatment only in a minority of amenorrhea-galactorrhea patients with and without tumors.

Amenorrhea↗

Inhibitory effect of calcitonin on growth hormone and insulin secretion in man.

The effect of calcitonin administration on basal and arginine-stimulated growth hormone and insulin plasma levels was investigated. The intramuscular injection of synthetic salmon calcitonin (100 U MRC) in five normal subjects produced a significant decrease (p less than 0.05) in insulin concentration. The same amount of calcitonin given 15 min before an arginine infusion test in seven normal subjects significantly reduced the response of growth hormone (p less than 0.025) and insulin (p less than 0.005) to the stimulus.

Adult↗

Comparison of placebo and bromocriptine in the treatment of patients with normoprolactinaemic amenorrhoea.

Fourteen women with normoprolactinaemic amenorrhoea were treated with bromocriptine (2.5 mg twice daily) for a period ranging from 4 to 17 weeks, while a matched group fo 19 amenorrhoeic women were treated with a placebo (one tablet twice daily) for 4 to 12 weeks. About half of the patients in both groups had at least one episode of vaginal bleeding during treatment. There was no clear difference in the menstrual and ovulatory pattern between placebo and bromocriptine groups.

Amenorrhea↗

Suppression of puerperal lactation by metergoline.

Based on the known stimulatory effect of serotonin on prolactin secretion, a trial of suppression of puerperal lactation by a potent serotonin antagonist, metergoline, was carried out in 30 puerperal women who did not want to nurse. The drug was administered orally at the dose of 4 mg tid for 5 days to all subjects, starting between 24 and 72 hours from delivery. Lactation was either prevented or rapidly suppressed in all subjects. Rebound of lactation after the end of treatment was observed in 10% of cases. Metergoline administration was associated with a significant suppression of the plasma prolactin levels.

Depression, Chemical↗

Failure of dopamine infusion to suppress the plasma prolactin response to sulpiride in normal and hyperprolactinemic subjects.

In eleven normal women dopamine infusion (5 microgram/Kg/min) significantly lowered plasma prolactin levels but failed to suppress the PRL response to sulpiride (10 or 100 mg i.v.), while the same dose of dopamine was effective in abolishing the PRL response to TRH (200 microgram i.v.). In four hyperprolactinemic women showing an impaired PRL response to sulpiride, dopamine infusion was effective both in lowering PRL circulating levels and in restoring an evident response to sulpiride. This finding suggests an impairment of endogenous dopamine activity in hyperprolactinemic amenorrhea.

Amenorrhea↗