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M Ziveri

Publications and source records attributed to M Ziveri.

13 recordsLinked to original sources
PubMed2001

Interactions of leptin and thyrotropin 24-hour secretory profiles in short normal children.

Thyroid hormones and leptin have effects on similar aspects of body homeostasis, such as energy expenditure, thermogenesis, and metabolic efficiency. Thus, the cross-talk between the thyrostat and the lipostat might play a crucial role in the maintenance of body homeostasis. To investigate the relationship between the hypothalamic-pituitary-thyroid (HPT) axis and leptin under physiological conditions, we evaluated the pulsatility and circadian rhythmicity and time-cross-correlated the 24-h secretory patterns of leptin and TSH in 12 short normal prepubertal children (6 girls and 6 boys). In both male and female subjects, leptin was secreted in a pulsatile and circadian fashion, with a nocturnal leptin surge that was more pronounced in males than in females. Mean 24-h leptin levels and total area under the curve were significantly higher in girls than in boys. This was mainly due to the nighttime mean leptin levels and total area under the curve, which were higher than those in boys. The cross-correlated 24-h leptin and TSH levels revealed significant positive and negative correlations. The positive one, of leptin over TSH, suggests a positive feedback regulation by leptin on the HPT axis, which might play an important role in triggering the neuroendocrine response to starvation, including decreased thyroid hormone levels. The negative correlation, of TSH over leptin, could explain the compensatory changes in adipocyte metabolism, and indirectly in circulating leptin levels, in response to alterations in thyroid status. In conclusion, we suggest that under baseline physiological conditions, the HPT axis has a prevailing inhibitory effect on leptin secretion, whereas leptin has a prevailing positive effect on the HPT axis. The sexual dimorphism in leptin levels does not seem to influence in a major way the interactions between the HPT axis and leptin.

Body Height↗
PubMed2000

[Interstitial laser therapy in benign prostatic hyperplasia].

The interstitial laser therapy is a low invasivity system for prostatic benign hyperplasia. We report our experience with Indigo 830e new system where diode laser and optical temperature sensor warrant a laser-induced interstitial thermal therapy able to continuously adjust energy delivery to the tissue.

Aged↗
PubMed1997

[State of the art in Nd:Yag laser treatment of benign prostatic hyperplasia].

Laser energy is widely used in medical sciences nowadays. Recently it has gained importance in urology as an alternative treatment, less invasive than conventional surgical approaches, to benign prostatic hypertrophy (BPH). The Authors present a review of the literature describing the different approaches to the laser treatment of BPH: visual laser ablation of the prostate (VLAP), TULIP, contact vaporization and interstitial laser therapy. They try to show vantages and limitations of this technique respect to conventional surgery. They also present their personal experience with VLAP. They conclude that prostate laser therapy is an alternative to TURP for patients suffering for uncomplicated BPH of small to medium volumes (< 40 ml). According to literature's data and personal experience, it seems that VLAP, the easiest technique, is able to achieve the best results.

Humans↗
PubMed1994

Dynamics of 24-hour pulsatile cortisol, 17-hydroxyprogesterone, and androstenedione release in prepubertal patients with nonclassic 21-hydroxylase deficiency and normal prepubertal children.

To assess whether the quantitative and qualitative aspects of cortisol, 17-hydroxyprogesterone (17-OHP), and androstenedione (D4A) secretion in patients with nonclassic congenital adrenal hyperplasia (NCCAH) differ from those in normal children, 24-hour serum concentrations of these steroids were measured in five prepubertal patients with NCCAH and five normal prepubertal children. Adrenal steroid profiles obtained by 30-minute sampling were analyzed by the Pulsar program. In comparison to normal children, the 24-hour quantitative parameters of 17-OHP and D4A secretion were significantly greater in NCCAH patients, but serum cortisol concentrations were similar in the two groups. When daytime and nighttime hormone releases were separately analyzed, a significant nocturnal elevation of the cortisol area under the curve above zero level (AUCo) and 12-hour mean and 17-OHP AUCo, AUC above baseline, mean peak height, amplitude, area, and 12-hour mean was detected in normal subjects only. Conversely, NCCAH patients exhibited an increased frequency and number of 17-OHP secretory peaks at night together with a reduction of the interpeak interval. No significant day/night differences in D4A concentrations were detected either in normals or in the patients. In conclusion, the results of the present study indicate that patients with NCCAH have a distinct pattern of adrenal steroid secretion characterized by a high-frequency 17-OHP release accompanied by a relative nocturnal cortisol deficiency.

17-alpha-Hydroxyprogesterone↗
PubMed1993

[Performance and utility of a quick immunological method for the measurement of HbAlc in a pediatric diabetes unit].

This study compares the results of a new immunoassay method (DCA2000, Ames) used to measure HbAlc concentration in 9 min using 1-microliter capillary blood sample with those obtained with an ion exchange traditional method (HPLC, DIAMAT, Biorad) in both a non-diabetic and a diabetic pediatric population. All HbAlc values were measured in the two methods on the same whole-blood venous aliquot after we had excluded differences in HbAlc values measured by DCA2000 on venous and capillary blood samples (8.5 +/- 1.4 vs 8.6 +/- 1.4%). Data analysis shows an excellent correspondence between the two assays (r = 0.97; p < 0.0001). HbAlc values obtained by DCA2000 method in diabetic patients are related to the mean value of the blood glucose levels collected at home in the last two months (r = 0.74; p < 0.003). The percentile distribution of the HbAlc values is similar both in DCA2000 (3-- = 4.4; 50-- = 5.3; 97-- = 6.0%) and in HPLC method (3-- = 4; 50-- = 5; 97-- = 5.9%). Within-run precision for DCA2000 ranges from 3.7 to 1.9% and between-run precision from 4.5 to 0.9%. The new immunoassay method gives accurate and reliable HbA1c values and compared with HPLC methodology has at least three advantages: it does not require venipuncture, provides HbA1c value within 9 miy and allows both physician and patient to verify in virtually' real time the degree of blood glucose control.

Adolescent↗
PubMed1992

GH response to GHRH, insulin, clonidine and arginine after GHRH pretreatment in children.

To determine whether differences in the neuroendocrine control of GH are present between children and adult subjects, the GH response to GHRH (1 microgram/kg) (group 1), insulin-induced hypoglycemia (0.1 U/kg iv) (group 2), clonidine (150 micrograms/m2 po) (group 3) and iv arginine (0.5 g/kg in 30 min) (group 4) after GHRH pretreatment (1 microgram/kg) was studied in 26 short-stature normal children (mean age 10.2 years). The results were compared with historical data in adults. No differences were present among mean peak GH levels after the first and second stimuli in groups 1, 2 and 3, while in group 4 the GH response to arginine administration was lower than that obtained after the initial GHRH (0.43 +/- 0.04 vs 0.9 +/- 0.13 nmol/l). Moreover, comparing the GH peak values following the second stimulus, it appears that the greatest GH responses were elicited by GHRH (1.31 +/- 0.23 nmol/l) and clonidine (1.11 +/- 0.22 nmol/l), while the lowest was elicited by arginine (0.43 +/- 0.04 nmol/l). In adults, sequential GHRH administration leads to inhibition of the response of the somatotropes, probably mediated by an increase in hypothalamic somatostatin. Our results confirm that after GHRH prestimulation GHRH elicits a significant GH response suggesting that activation of the somatostatinergic tone is less effective in children. This hypothesis also explains the low GH response to arginine which acts selectively through somatostatin inhibition.

Adolescent↗
PubMed1990

Pulsatile growth hormone release in Turner's syndrome and short normal children.

To determine whether the quantitative and qualitative aspects of GH secretion in girls with Turner's syndrome are similar to those of short-normal children we studied the 24-h GH secretion of 10 patients with Turner's syndrome and 9 short-normal children with comparable auxological features. GH profiles, obtained by 30-min sampling, were analysed by the Pulsar programme. The pulsatile GH release over the 24 h in Turner's syndrome was similar to that in normal children. However, when the GH release over the 12 day and night hours were separately analysed, only normal children showed a night-time increase in the sum of peak amplitudes. Moreover, patients with Turner's syndrome had significantly decreased number and frequency of peaks in the night-time compared with short children. In short-normal children but not in Turner's syndrome, height velocity was related to the 24-h integrated concentration of GH, area under the curve over zero-line and over baseline, sum of peak areas, and amplitudes. Night-time GH area over zero-line and over baseline, mean peak amplitude, height area, sum of peak area and amplitudes were positively correlated with height velocity in short children, whereas in Turner's syndrome height velocity was related to daytime parameters only. In conclusion, girls with Turner's syndrome have a discrete pattern of pulsatile GH release. However, the relation of GH secretion to growth in these patients, is uncertain.

Body Height↗
PubMed1989

Adrenal steroid, cortisol, adrenocorticotropin, and beta-endorphin responses to human corticotropin-releasing hormone stimulation test in normal children and children with premature pubarche.

To determine whether CRH affects adrenal androgen, beta-endorphin (B-E), and ACTH secretion in normal children during sexual maturation, 17-hydroxyprogesterone (17-OHP), androstenedione (D4-A), dehydroepiandrosterone (DHEA), DHEA sulfate (DS), cortisol, B-E, and ACTH were measured after an iv injection of 1 microgram/kg human CRH. Children with premature pubarche were similarly analyzed to establish whether this condition is accompanied by altered hormonal responses to CRH. CRH produced consistent increases in ACTH, B-EP, and cortisol blood levels, which were comparable at all age intervals in all groups. 17-OHP increased after CRH injection, but its response linearly with age. D4-A levels were not influenced, while DHEA and DS levels were only partially influenced by CRH. The stimulated D4-A to 17-OHP ratio increased with sexual maturation, whereas ratios of cortisol to 17-OHP and D4-A to DHEA remained constant. Children with premature pubarche had hormonal responses similar in magnitude to those of prepubertal children of comparable age. In conclusion, an increase in 17,20-desmolase efficiency occurs with postnatal maturation after CRH challenge. Moreover, CRH does not appear to play an important role in premature pubarche.

17-alpha-Hydroxyprogesterone↗
PubMed1981

[Premature thelarche and precocious puberty. Clinical findings and endocrinological data useful for differential diagnosis].

Clinical features, urocytogram and gonadotropin response to LHRH (100 microgram/1,73 m2 i.v.) were evaluated in 10 girls with premature thelarche and 4 girls with precocious puberty to purpose to describe the differences between the two diseases. The subjects with Premature Thelarche showed peculiar clinical and endocrinological characteristics which allowed their discrimination from patients with Precocious Puberty: 1) breast development of mild degree without any modification of nipples and areolae and not accompanied by pubic hair or morphologic changes of genitalia; 2) spontaneous regression of thelarche more or less complete (6/10 cases); 3) not anticipation of puberal maturation; 4) growth rate not accelerate (only a mild advancement of statural age was observed); 5) LH/FSH ratio at prepuberal levels; 6) mean LH peak values overlapping to those obtained in normal infants under 1 year of age. Our findings confirm that: 1) the girls with Premature Thelarche showed different growth pattern and clinical features than those observed in the girls with Precocious Puberty; 2) LHRH test and urocytogram are further valuable parameters for the differential diagnosis between Premature Thelarche and Precocious Puberty; 3) the isolated breast enlargement in girls under 8 years of age is likely to originate from a protracted gonadotropin hyperstimulation as in early life; 4) it is a variant of the normal, not difficult to asses, which merits, however further follow-up.

Adolescent↗
PubMedDate not supplied

[Lack of effect of therapy with LHRH analogs, alone or associated with flutamide, on prolactin levels in advanced prostatic carcinoma].

Fourteen patients with advanced prostatic carcinoma have been considered. Some were treated with goserelin depot and some with goserelin depot plus flutamide; basal and stimulated PRL were studied in the two groups before and after two months treatment in order to verify a possible interference with prolactin secretion which seems to have a trophic and stimulating effect on neoplastic tissue growth. Basal PRL levels and levels after TRH infusion haven't shown significant variations between the two groups of patients. Even if relative to a short time, our results exclude PRL increase, which might be suspected with these drugs, and at last confirm the effectiveness of this treatment (LHRH analogs plus flutamide) in prostatic carcinoma.

Adenocarcinoma↗