Insulin production and resistance in cystic fibrosis: effect of age, disease activity, and genotype.

AIM: To assess the major determinants of glucose tolerance between age, genotype, and clinical status in cystic fibrosis (CF) patients, and study if defects of insulin secretion and insulin sensitivity were associated with the onset of CF-related diabetes (CFRD). SUBJECTS AND METHODS: One hundred and nineteen patients, in stable clinical condition were studied. They were subdivided into 3 groups based on age, and 2 groups based on Schwachman-Kulczycki clinical score. All patients were genotyped, and subsequently divided into 3 groups. Ninety-four healthy normal-weight controls, comparable for sex and age were also studied. All subjects had baseline blood samples taken for glucose and insulin, C-peptide, and glycated hemoglobin. Homeostasis model assessment of insulin resistance (HOMA-IR), fasting glucose/insulin ratio (FGIR) were calculated as indices of IR and insulinogenic index as a marker of pancreatic ß-cell function. All patients underwent an oral glucose tolerance test, and 57 underwent an IVGTT for the calculation of first-phase (FPIR) and acute insulin responses (AIR). RESULTS: The F508del homozygous patients had an increased chance of developing impaired glucose tolerance (IGT) and significantly lower FPIR, decreased HOMA-IR, and insulinogenic index. Heterozygote F508del patients had an increased chance of having normal glucose tolerance. HOMA-IR, FGIR, and insulinogenic index did not change with age or clinical score. HOMAIR correlated with FPIR. FPIR correlated positively with insulinogenic index. AIR correlated negatively with FGIR, and positively with C-reactive protein. In multiple linear regression analyses, glucose tolerance was related to the agegroup, and to the HOMA-IR and insulinogenic indexes. CONCLUSIONS: IGT and CFRD were related mainly to genotype, although, as expected, the prevalence increased with age. The data suggested a possible combined contribution of insulin deficiency, ß-cell function, and reduced insulin sensitivity to the onset of CFRD; however, further studies are warranted to better elucidate this aspect.

Impairment of insulin receptor signal transduction in placentas of intra-uterine growth-restricted newborns and its relationship with fetal growth.

OBJECTIVE: Intra-uterine growth restriction (IUGR) is related to a higher incidence of type 2 diabetes mellitus. We previously reported reduced adiponectin and increased interleukin 6 (IL6) concentrations in IUGR placentas, which are features of insulin resistance. We aimed to investigate placental insulin receptor (IR) function and activation in human placenta and subsequently the relationships of insulin signalling peptides with placental protein content in IL6, insulin, resistin and adiponectin, and with parameters of fetal growth. DESIGN AND METHODS: Whole villous tissue was collected from 18 IUGR and 24 appropriate for gestational age (AGA) placentas of comparable gestational age. Insulin signalling peptides, suppressors of cytokine signalling-2 (SOCS2), insulin, adiponectin, resistin, and IL6 concentrations were determined by using western immunoblotting or specific research kits. RESULTS: The amount of total IR was similar in both groups but activated IR significantly higher in IUGR. Total IR substrate-1 (IRS1) was increased in IUGR, whereas total IRS2 and activated IRS1 were similar. AKT content was reduced and activated AKT was undetectable in IUGR placentas. c-Jun N-terminal kinase content was reduced in IUGR. Total and activated ERK1/2 was similar in IUGR and AGA groups, and total SOCS2 was increased in IUGR. IL6 lysate concentrations correlated with AKT content and activated IR. Correlations were found also with adiponectin and resistin. SOCS2 correlated negatively with all growth parameters at birth. CONCLUSIONS: IR was more activated in placentas of IUGR compared with AGA; however, signal transduction downstream of the receptor was impaired. The increase in activated IR could be in favour of a compensatory mechanism to increase insulin sensitivity. Close relationships of insulin action in placenta with fetal growth were shown.

Interleukin-6 and insulin-like growth factor system relationships and differences in the human placenta and fetus from the 35th week of gestation.

The integrity of the insulin-like growth factor (IGF) system is essential for normal fetal growth. Cytokine and IGF-IGFBP relationships have been shown in specific tissues, but it is unknown whether these occur in the placenta. We aimed to assess possible differences in the IGF system depending on gestational age (GA) from week 35 to 40, and to study relationships of IL-6 with components of the IGF system in the placenta and newborn infant. We followed 32 normal births and collected whole villous tissue and cord serum. Total RNA was extracted from the placenta samples, reverse transcribed and then real-time quantitative (TaqMan) RT-PCR was performed to quantify cDNA for IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IL-6. The corresponding proteins were assayed in placenta lysates and cord serum using specific commercial kits. Two groups of subjects (Group 1, 35-37 weeks GA, N=12 and Group 2, 38-40 weeks GA, N=20) were studied. In placenta, IGF-I mRNA was more abundant than IGF-II mRNA at all times and together with IGFBP-1mRNA were less expressed at term. IGFBP-2 and IL-6 mRNAs were higher after week 37 GA. IL-6 and IGFBP-2 gene expression were closely related. The corresponding proteins showed similar differences to the genes but IGF-I was undetectable in the lysates, whereas IGF-II was abundant. IGFBP-2 concentrations were very high and greater than those of IGFBP-1. In the newborn, no difference was seen in any cord serum protein after week 35 GA. IGFBP-1 was negatively correlated with parameters of neonatal size. In conclusion, this study reports new insights into IL-6, IGF-IGFBP relationships within the human placenta and shows the importance of comparing subjects with the same GA.

Decreased androgen receptor gene methylation in premature pubarche: a novel pathogenetic mechanism?

CONTEXT: Several studies found links between DNA methylation and gene expression. In patients with idiopathic hirsutism, a preferential methylation of the of shorter androgen receptor (AR) alleles was hypothesized to be responsible for the abnormal hair growth. OBJECTIVE: The objective of this study was to assess whether abnormalities in the AR function in both peripheral blood leukocytes (PBLs) and androgen target tissues are present in children with premature pubarche (PP). DESIGN: Human DNA was extracted from PBLs and pubic hair and CAG repeats length and methylation status of the AR gene were analyzed. SETTING: The study was performed at a Pediatric Endocrinology referral clinic. PATIENTS: Twenty-five girls with PP, 23 prepubertal children, and 10 girls with Tanner stage II pubertal development were studied. MAIN OUTCOME MEASURE: The main outcome measures were CAG repeat length and AR methylation pattern in PBLs and pubic hair. RESULTS: In PBLs from PP patients, AR gene methylation was significantly lower (P < 0.01) than that of prepubertal children and similar to that of girls with Tanner II stage pubertal development. A negative correlation between AR gene methylation in PBLs and the age of normal children was detected. PATIENTS with PP exhibited a hair follicle AR methylation pattern similar to that of Tanner stage II girls. The mean number of CAG repeats was lower in PP patients than in prepubertal and Tanner stage II girls, although it was within the normal range for the general population in both groups. CONCLUSIONS: The increased AR gene activity observed in PP patients, as indicated by the reduced AR gene methylation pattern, together with the presence of shorter CAG repeats, might lead to hypersensitivity of the hair follicles to steroid hormones and therefore to the premature development of pubic hair.

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.

[Interstitial laser therapy in benign prostatic hyperplasia]. / Terapia laser interstiziale nell'iperplasia prostatica benigna.

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.

[Intratesticular adenomatoid tumor]. / Tumore adenomatoide intratesticolare.

A case of adenomatoid tumor of the testis is shown. Of this rare benign neoplasm a review of the literature is presented.

[State of the art in Nd:Yag laser treatment of benign prostatic hyperplasia]. / Lo stato dell'arte nel trattamento dell'ipertrofia prostatica benigna con laser Nd:Yag.

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.

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.

[Performance and utility of a quick immunological method for the measurement of HbAlc in a pediatric diabetes unit]. / Performance e utilità di un metodo immunologico rapido per il dosaggio dell'HbAlc nell'ambulatorio diabetologico.

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.

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.

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.

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.

[Lack of effect of therapy with LHRH analogs, alone or associated with flutamide, on prolactin levels in advanced prostatic carcinoma]. / Mancanza di effetti della terapia con analogo di LHRH, solo o associato a flutamide, sui livelli di PRL nel carcinoma prostatico in stadio avanzato.

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.

[Premature thelarche and precocious puberty. Clinical findings and endocrinological data useful for differential diagnosis]. / Telarca prematuro e pubertà precoce. Rilievi clinici e dati endocrinologici utili per la diagnosi differenziale.

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.