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Biomedical subjects

F Morabito

Publications and source records attributed to F Morabito.

At least 127 records · Page 7Linked to original sources
PubMed1986

Effect of thyrotropin-releasing hormone on growth hormone release in normal subjects pretreated with human pancreatic growth hormone-releasing factor 1-44 pulsatile administration.

Growth hormone (GH) increase after thyrotropin-releasing hormone (TRH) has been documented in many pathological conditions. In order to evaluate whether exposure to growth hormone-releasing factor (GRF) might contribute to this effect in normal subjects, we studied GH responses to placebo, TRH, GRF and GRF plus TRH either in basal condition or after GRF administration. Ten subjects received placebo, TRH, GRF and GRF plus TRH on four separate occasions. GRF induced a clear rise in plasma GH, statistically different from those obtained after placebo or TRH (p less than 0.01). TRH was completely ineffective in both stimulating GH release and amplifying the secretory GH response to GRF. Twenty subjects, subdivided in four groups, received 3 consecutive intravenous GRF boli at two-hour intervals. Two hours later they were given a fourth stimulus: 5 had another 25 micrograms GRF i.v., 5 had 200 micrograms TRH i.v., 5 were tested with simultaneous 25 micrograms GRF and 200 micrograms TRH i.v. injection, and 5 with 1 ml saline. GH secretory responses were quantitated by determining the net incremental area under the curve (nAUC) over 60 min after the administration of each stimulus. The pattern of GH secretion after 1-3 GRF boli was not statistically different among the four groups. Plasma GH nAUC was higher after the first GRF injection than after the following ones (p less than 0.01). The administration of a fourth GRF bolus also caused a GH increase which was significantly smaller than that after the first one (p less than 0.01), but greater than that after placebo (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Effect of an acute injection of melatonin on the basal secretion of hypophyseal hormones in prepubertal and pubertal healthy subjects.

It is well known that the pineal gland can modulate the secretion of pituitary hormones. Melatonin, the main hormone produced by the pineal gland, acts at the hypothalamic site, whereas hypophyseal sensitivity to melatonin seems to change with age. To investigate the influence of pubertal development on the role of the pineal gland in the regulation of the secretion of pituitary hormones, FSH, LH, Prl, TSH and GH responses to melatonin were evaluated in a group of 9 prepubertal and 10 pubertal healthy subjects of both sexes. Melatonin was given im at a dose of 0.2 mg/kg body weight at 3 p.m. Venous blood samples were drawn -20, 0, 20, 40, 60, 90, 120, 180 and 240 min, after melatonin injection. According to the same experimental protocol, venous blood samples were collected during a saline infusion on a separate occasion. FSH, LH, Prl, TSH and GH plasma levels were measured with RIA. In pubertal subjects, a significant rise in the mean Prl levels was seen 90 min after melatonin as compared with those during saline infusion. The Prl melatonin response area was significantly lower in prepubertal treated subjects and significantly higher in pubertal ones compared with the respective controls. The mean GH values showed a significant decrease 120 min after melatonin only in prepubertal subjects; no significant variations were seen in 8 of 10 pubertal subjects, whereas in the last 2 a marked increase was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Daily secretion of parathyroid hormone in adult subjects].

Data reported in the literature on the existence of a circadian rhythm in PTH secretion are contradictory. In order to assess whether haematic PTH levels vary over a 24 hour period, the plasma levels of the hormone were evaluated at 6 different times during the day (12, 19, 24, 2, 4, 6 hours) in a group of 10 healthy adults (5 males, 5 females), aged from 24.8 to 48.7 years. PTH values were determined by the double antibody radioimmunological method using commercially available kits (PTH-K Sorin-Saluggia), whose antiserum reacts with C terminal fraction of the hormone. No statistically significant differences were observed, either between the sexes or among the samples collected during the 24 hour period. The results therefore seem to preclude the existence of a circadian rhythm in PTH secretion. However, further studies and more data - based on RIA methods, whose antiserum reacts with the N terminal of the hormone - would be necessary to preclude the existence of rapid circadian variations in PTH over the 24 hour period.

Adult↗
PubMed1985

Effects of melatonin on PRL secretion during different photoperiods of the day in prepubertal and pubertal healthy subjects.

The effect of melatonin on PRL secretion has not been established yet. In an attempt to establish whether PRL response to melatonin changes in relation to the photoperiods of the day and pubertal maturation, we evaluated PRL plasma levels after melatonin administration in 19 prepubertal and pubertal healthy subjects of both sexes in two different periods of the day: in the morning, when the sensitivity to melatonin is low, and in the afternoon, when the responsiveness to melatonin is higher. Melatonin was given im at a dose of 0.2 mg/kg BW PRL plasma levels were determined with double antibody RIA method. When melatonin was administered in the morning, all pubertal subjects and 7 of 9 prepubertal ones showed no significant variation of PRL levels; a significant decrease was observed in the other 2 prepubertal subjects. On the contrary, when melatonin was given in the afternoon, a significant increase in PRL plasma levels was seen in all pubertal subjects; no significant changes were found in 6 prepubertal ones, while in the other 3 a marked decrease could be observed. The results reveal that the response of PRL to melatonin depends upon the times of day of administration and on pubertal development.

Adolescent↗
PubMed1983

[Functional evaluation of cystic thyroid nodules].

7 patients (age between 22 and 52 years, mean 38.2 +/- 10.6 SD) with cystic nodules have been subjected to the same diagnostic screening (scintiscanning and echography, needle aspiration); in every subject hormonal pattern has been studied at the cyst and periphery level. The Authors found very high TG levels in the cyst's fluid, perhaps due to an increased sensitiviness to the thyrotropic hormone, and an rT3/T4 increased at periphery level, probably because an enhancement of mechanisms connected to the reuptake of iodine. These reports outline the great importance in the induction and development of cystic nodules of changes related to the enzymatic steps of iodination and coupling.

Adult↗
PubMed1983

Age and sex related variations in biologically active and immunoreactive serum luteinizing hormone.

Relatively recent data from the literature show some discrepancies between bioactive LH (Bio-LH) and radioimmunoreactive LH (Ria-LH) in different endocrinological conditions. In 202 subjects of both sexes we have studied biologically active and immunoreactive LH and their ratio (B/l ratio) pattern through life. The results show that in male puberty the in vitro bioassay method gives a more discriminating measurement of serum LH than the radioimmunoassay. The ratio between bioactive and immunoreactive LH is well correlated with the increase of serum testosterone levels from male prepuberty to adulthood. On the contrary, there is no difference of B/l ratio between prepubertal girls and fertile women, in spite of the different gonadotropin levels. Finally LH bioactivity increases less markedly in elderly men than in postmenopausal women. These data suggest that, among several factors which may influence not only the quantity but also the quality of LH secreted, gonadotropin secretion rate and sex steroid milieu play an important role and may partly explain the B/l ratio changes in the situations investigated.

Adolescent↗
PubMed1982

"In vitro" colony growth of blood T-lymphocytes from B-cell chronic lymphocytic leukemia.

T-lymphocyte colony formation in agar culture was investigated in 20 untreated B-cell Chronic Lymphocytic Leukemia (CLL) patients in stage O. As compared to the controls, colony growth was very poor when unseparated peripheral-blood lymphocytes from CLL-patients were seeded. The number of colonies was greatly higher when T-cell enriched fractions from CLL were plated; however, they failed to reach the normal range even in this experimental condition. The role of adherent cells in the colony growth was also investigated. Depletion of these cells resulted in impaired colony generation either in normals or in CLL-patients, which was subsequently restored by the addition of the same adherent cells. In the patients investigated in this study, an imbalance of T-subsets was found with increase of OKT8-positive cells (T-suppressors). When the number of colonies and the percentage of OKT8-positive cells were plotted, an inverse correlation was found. Conversely, a linear relationship was detected between the percentage of OKT4-positive cells (T-helpers) and the values of colonies. On the basis of the present experiments, it is suggested that the defective colony growth of T-cell fractions in B-cell CLL may be related to the low number of OKT4-positive cells plated, which are known to be mainly responsible for the colony generation in agar culture.

Adult↗
PubMed1980

[Liver cell membrane autoantibody (LMA) in chronic liver disease].

The incidence of LMA, detected by indirect IF on isolated rabbit hepatocytes, was significantly higher in CAH-non B (58%) than in CAH-B (15%). Sera from AVH patients showed a smaller percentage of positivity whereas the CPH patients were negative. The organ-specificity, the high incidence in relation to other non-organ-specific autoantibodies and the inverse correlation with the markers of HB Virus, make LMA a specific and sensitive marker of "autoimmune" chronic liver disease.

Acute Disease↗
PubMed1980

Multiple myeloma in husband and wife.

An instance of multiple myeloma (MM) in a married couple is discussed, since cases of MM in husband and wife have rarely been observed. The patients were aged 60 when the disease was discovered, and the interval between the diagnosis in the mates was 44 months. Genetic or environmental factors that could have explained the occurrence of myelomatosis were not found in these spouses. Therefore, on absence of a defined cause, our observation, like others previously reported in the literature, should be considered, although exceptional, a chance event.

Female↗