Biomedical subjects

L Ghizzoni

Publications and source records attributed to L Ghizzoni.

14 recordsLinked to original sources

PubMed1992

Congenital anorchia: natural history and treatment.

This paper discusses the definition, pathogenesis, diagnosis and treatment of congenital anorchia. It concludes that preparations containing esters of testosterone are preferable to synthetic derivatives for long-term treatment as they are metabolized in the same way as endogenous testosterone. In addition, it appears that recommended doses for replacement therapy are lower than previously suggested. An ideal formulation of testosterone for use in androgen replacement therapy is not currently available.

Adolescent↗

PubMed1992

Clinical data regarding the growth of diabetic children.

Many authors have reported retarded growth in children with diabetes, though this has been a somewhat variable finding. However, with the newer treatment regimens for diabetes the problem of reduced growth rates has largely been solved.

Adolescent↗

PubMed1992

Natural history of premature pubarche: an auxological study.

The natural history of girls with premature pubarche is reported to be normal, but the effects on puberty and on final height are not well documented. We assessed the outcome of a group of girls with premature pubarche from two Latin populations in whom 21-hydroxylase deficiency had been ruled out by an ACTH test. Patients comprised 127 girls (70 Northern-Italian and 57 Northern-Spanish), of whom 69 had entered puberty and 38 had attained adult height. Height, bone age, onset and progression of puberty, height prognosis, adult height, and baseline plasma androgen levels were evaluated. Advanced skeletal maturation and tall stature were constant features during the first years of follow-up and subsequently declined. Puberty began at 9.7 +/- 0.9 yr, and age at menarche (12.0 +/- 1.0 yr) was comparable to maternal and population menarcheal ages. The appearance and chronology of pubertal milestones in both populations were very similar. Adult heights correlated with the height prognosis at diagnosis and at onset of puberty, and were above midparental heights. Premature pubarche produces a transient acceleration in growth and bone maturation with no negative effects on the onset and progression of puberty and final height.

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↗

PubMed1991

Effectiveness of growth-promoting therapies. Comparison among growth hormone, clonidine, and levodopa.

The ability of growth hormone, clonidine, and levodopa to stimulate growth was compared in short and slowly growing children randomly assigned to different treatment regimens for 6 months. There were 10 children in each group, and 10 additional subjects served as controls. Growth hormone improved mean height velocity, height velocity SD score, and height SD score. The mean height velocity and height velocity SD score were significantly increased by clonidine, while levodopa only enhanced the mean height velocity SD score of the treated children. Moreover, in nine patients (90%) receiving growth hormone, two (20%) receiving clonidine, and one (10%) receiving levodopa, the height velocity was raised by more than 2 cm/y. The increments in height velocity and height SD score were greatest in the growth hormone group. Clonidine induced an increase in height velocity significantly different from that in control children only. In the control group, there was a significant reduction of height SD score with time.

Body Height↗

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

Thyroid function tests in children with congenital hypothyroidism on L-thyroxine treatment.

The plasma levels of thyroxine (T4), triiodothyronine (T3), free T4 (FT4), free T3 (FT3), reverse T3 (rT3) and immunoradiometrically assayed thyrotropin (IRMA TSH) have been measured in 28 L-T4-treated children with congenital hypothyroidism as well as in a control group (group C). The patients were subdivided into 2 groups according to the nonsuppressed (group A) or suppressed (group B) TSH response to TSH-releasing hormone (TRH). Basal IRMA TSH correlated with the TSH increment after TRH and it was significantly lower in group B vs. groups A and C, while no difference was present between groups A and B in regard to T4, FT4 and rT3, all higher than in group C. FT3 levels were similar in the 3 groups. In children, as in adults, basal IRMA TSH seems to be a reliable index in monitoring overtreatment.

Adolescent↗

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↗

PubMed1989

Delayed puberty.

Explore the source record for details and available documents.

Adolescent↗

PubMed1988

Final height in a group of untreated children with constitutional growth delay.

We retrospectively evaluated the growth of 41 children with constitutional growth delay followed till adulthood and never treated with growth-promoting therapies. Final height has been correlated with prepubertal height, genetic target and height prediction calculated in both prepuberty and puberty. All patients showed a significant improvement of their height standard deviation score (HSDS) from prepuberty to adulthood, and the great majority of them achieved a final height above the 3rd percentile. Moreover, we found a good correlation between final height and both genetic target and height prediction, even if the latter overestimated final height in 25% of the patients. In conclusion, our data confirm that constitutional growth delay is a normal variant of growth. Therefore, caution should be paid in considering pharmacological treatment of this condition.

Adolescent↗

PubMed1986

Blood pressure behaviour and control in Turner syndrome.

UNLABELLED: Adult Turner syndrome (TS) patients frequently present hypertension. To clarify the pathogenesis of this hypertension we examined the blood pressure (BP) behaviour and the renin-angiotensin-aldosterone system in 31 TS patients (2-22 years of age). BP levels were occasionally elevated in 47% of the subjects and constantly elevated in 23%. Most of the patients were on estrogen replacement therapy, but 26% of them presented with elevated levels since childhood. Supine and upright plasma renin activity (PRA) values were higher in TS compared to controls and more elevated in hypertensive TS than in the normotensive ones. At Captopril challenge TS showed different PRA responses regardless of the karyotype and clinical features. Patients on estrogen therapy, however, exhibited higher increments of PRA after Captopril. CONCLUSIONS: TS patients show high frequency of hypertension in pediatric age. Estrogen therapy is an outbreaking and worsening factor. An estrogen independent role of the renin-angiotensin-aldosterone system in the pathogenesis of TS hypertension is still uncertain.

Adolescent↗

PubMed1985

Characterization of variations in rabbit hepatic progesterone 21-hydroxylase activity by serial biopsy.

Earlier work has shown that the 21-hydroxylation of progesterone in the hepatic microsomal fraction of outbred New Zealand White rabbits varies over a 10-fold range. To determine whether the differences in 21-hydroxylase activity were due to a transient inductive effect, livers from a group of 28 rabbits were serially biopsied at least three times over a minimum period of two months. Both progesterone 21- and 16 alpha-hydroxylase activities were determined in the post-8700g supernatant of homogenates prepared from these biopsy samples. A substantial variability in both the 21- and 16 alpha-hydroxylase activity was observed for serial biopsy samples from individual rabbits. Each animal was found, however, to maintain relatively constant ratios of 21/16 alpha-hydroxylase activity throughout the course of the study. Previous studies have indicated that the 21-hydroxylase activity does not correlate with the 16 alpha-hydroxylase activity and that the 21-hydroxylase phenotype could be determined from the ratio of these activities. On the basis of this ratio, two groups of animals could be distinguished in the present study. Approximately 25% of the animals exhibited an elevated 21/16 alpha-hydroxylase ratio (greater than 1.5), the remainder were below this level. Furthermore, the expression of elevated levels of the 21-hydroxylase activity were found to be consistent within this subpopulation suggesting that a transient inductive effect is not responsible for the differences in 21-hydroxylase activity among populations of outbred New Zealand White rabbits. This study demonstrates the determination of the hepatic enzymatic phenotype while maintaining the animal for long periods of time and for subsequent investigations.

Animals↗

PubMed1985

Evidence that variation among untreated rabbits in hepatic progesterone 21-hydroxylase activity is indicative of enzyme heterogeneity rather than a transient inductive effect.

Previous work has shown that the 21-hydroxylation of progesterone in the hepatic microsomal fraction of outbred NZW rabbits varies over a tenfold range. In contrast, the 16-hydroxylase activity is relatively constant and is not correlated to the activity of the 21-hydroxylase. The distribution of the 21-hydroxylase activity is roughly bimodal with about one-third of the animals (21-H) exhibiting 21-hydroxylase activity exceeding 1 nmol/min/mg microsomal protein, whereas the remainder (21-L) generally exhibit an activity that is less than 1 nmol/min/mg protein. To determine if this was due to a transient phenomenon, liver punch biopsies were collected from 28 rabbits at intervals of approximately three weeks for at least three serial samples. The 21- and 16-hydroxylase activities were determined in the postmitochondrial fractions of these biopsy samples. A substantial variability in both 21- and 16-hydroxylase activities was observed for serial biopsy samples from individual rabbits. The variation of the 16-hydroxylase activity paralleled, however, that of the 21-hydroxylase, thus suggesting that the variation between biopsy samples for individual rabbits was due to factors such as contamination with blood and connective tissue, which would affect both activities equally. Rabbits, therefore, were phenotyped as 21-H or 21-L on the basis of the 21/16-hydroxylase ratio. The mean ratio was 3.2 +/- 1.2 and 0.8 +/- 0.3 for rabbits phenotyped as 21-H and 21-L, respectively. Similar values for this ratio were obtained for the other group of rabbits phenotyped as 21-H and 21-L, 3.8 +/- 1.6 and 0.5 +/- 0.2, respectively, following the isolation of microsomes from whole liver homogenates. The ratio of 21/16-hydroxylase activity was found to be relatively constant for biopsy samples obtained from the same animal over the course of this study, thus indicating that the elevated 21-hydroxylase activity is not a transient phenomenon.

Animals↗

PubMedDate not supplied

[Peripheral androgen resistance syndrome].

Two main topics of 5 alpha reductase deficiency and androgen receptors defects have been considered. Particularly, the differential diagnosis among the different syndromes of androgen resistance and the important issue of sex assignment are discussed.

Cholestenone 5 alpha-Reductase↗