Biomedical subjects

N Georgopoulos

Publications and source records attributed to N Georgopoulos.

10 recordsLinked to original sources

PubMed2004

Treatment delay and pathology results in women with low-grade squamous intraepithelial lesions. A preliminary study.

Regression rate of CIN 1 (LSIL) can reach 85%. The purpose of this study was to investigate retrospectively pathology specimens in CIN 1 cases who delayed treatment > 2 years despite the persistence of the lesion. One hundred and fifteen women diagnosed with CIN 1 were separated in two groups as follows: A) 92 women who underwent ablative treatment within three months after the completion of two years; B) 23 women who delayed ablative treatment for a mean interval of > 1 year after the completion of two years. Exclusion criteria were normal cytology and colposcopy results within the completion of two years. The chi-square, t-test and Kaplan-Meier method were used for analysis. Persistence of LSIL lesions was observed in 84% of the first group and persistence or regression of the lesion in 78% of the second one. The study suggests the possibility of prolongation of the observation period after LSIL diagnosis. Prospective studies with close follow-up are needed for final conclusions.

Adult↗

PubMed2001

Novel application of IGF-I and IGFBP-3 generation tests in the diagnosis of growth hormone axis disturbances in children with beta-thalassaemia.

OBJECTIVE: Children with beta-thalassaemia major (beta-thal) frequently have growth retardation in the presence of low serum IGF-I and a normal GH response to pharmacological stimulation suggesting that they have GH insensitivity (GHIS). This study was carried out to study the cause of their growth retardation. DESIGN: We studied IGF-I and IGFBP-3 generation after exogenous GH administration for four days, in 15 prepubertal controls (C) and 41 prepubertal beta-thal patients divided into three groups according to their growth status: (Group 1) 15 with normal growth (N-thal) (Group 2) 16 with decelerated growth (D-thal) and (Group 3) 10 with short stature (S-thal), in order to determine whether GHIS is the cause of their growth retardation. MEASUREMENTS: IGF-I and IGFBP-3 were measured daily, before and for 4 days after daily administration of 0.1 IU/kg hGH, in 3 groups of prepubertal beta-thal patients and normal controls. RESULTS: N-thal and C had similar basal serum IGF-I (142 +/- 52 and 196 +/- 56 ng/ml, respectively) and IGFBP-3 concentrations (2.07 +/- 0.49 and 2.66 +/- 0.41 mg/l, respectively) as well as a similar percent increase of IGF-I (101 +/- 23% and 104 +/- 37%, respectively) and IGFBP-3 (52 +/- 36%, and 38 +/- 14%, respectively) during the generation tests. S-thal and D-thal had significantly lower basal IGF-I and IGFBP-3 concentrations (85 +/- 42 and 101 +/- 36 ng/ml; and 1.60 +/- 0.49 and 1.79 +/- 0.52 mg/l, respectively) as compared to N-thal and C (P < 0.001 and P < 0.005, respectively), and a significantly higher percent increase of IGF-I and IGFBP-3 during the generation tests (249 +/- 43 and 161 +/- 76%; and 121 +/- 99 and 73 +/- 35%, respectively) as compared to N-thal and C (P < 0.0001 and P < 0.01, respectively). Twenty-five percent of the growth retarded patients had classic GH deficiency (GHD) and percent increases of IGF-I and IGFBP-3 in the generation tests (164 +/- 86% and 80 +/- 49%, respectively) which were similar to those of the remaining growth-retarded children. CONCLUSION: The greater percent increases of IGF-I and IGFBP-3 in the generation tests of the growth retarded beta-thal patients, both with and without GHD, strongly suggest impaired GH secretion rather than GHIS as the cause of their growth retardation. We conclude that the IGF-I and IGFBP-3 generation tests are useful tools for the study not only of GHIS but also of GH secretory disorders in patients with beta-thal and short stature that can easily be performed in an outpatient setting as an initial test to identify the patients that may benefit from GH therapy.

Adolescent↗

PubMed2001

Iodine-Induced hypothyroidism.

Iodine is an essential element for thyroid hormone synthesis. The thyroid gland has the capacity and holds the machinery to handle the iodine efficiently when the availability of iodine becomes scarce, as well as when iodine is available in excessive quantities. The latter situation is handled by the thyroid by acutely inhibiting the organification of iodine, the so-called acute Wolff-Chaikoff effect, by a mechanism not well understood 52 years after the original description. It is proposed that iodopeptide(s) are formed that temporarily inhibit thyroid peroxidase (TPO) mRNA and protein synthesis and, therefore, thyroglobulin iodinations. The Wolff-Chaikoff effect is an effective means of rejecting the large quantities of iodide and therefore preventing the thyroid from synthesizing large quantities of thyroid hormones. The acute Wolff-Chaikoff effect lasts for few a days and then, through the so-called "escape" phenomenon, the organification of intrathyroidal iodide resumes and the normal synthesis of thyroxine (T4) and triiodothyronine (T3) returns. This is achieved by decreasing the intrathyroidal inorganic iodine concentration by down regulation of the sodium iodine symporter (NIS) and therefore permits the TPO-H202 system to resume normal activity. However, in a few apparently normal individuals, in newborns and fetuses, in some patients with chronic systemic diseases, euthyroid patients with autoimmune thyroiditis, and Graves' disease patients previously treated with radioimmunoassay (RAI), surgery or antithyroid drugs, the escape from the inhibitory effect of large doses of iodides is not achieved and clinical or subclinical hypothyroidism ensues. Iodide-induced hypothyroidism has also been observed in patients with a history of postpartum thyroiditis, in euthyroid patients after a previous episode of subacute thyroiditis, and in patients treated with recombinant interferon-alpha who developed transient thyroid dysfunction during interferon-a treatment. The hypothyroidism is transient and thyroid function returns to normal in 2 to 3 weeks after iodide withdrawal, but transient T4 replacement therapy may be required in some patients. The patients who develop transient iodine-induced hypothyroidism must be followed long term thereafter because many will develop permanent primary hypothyroidism.

Amiodarone↗

PubMed2000

Increased sensitivity to the inhibitory effect of excess iodide on thyroid function in patients with beta-thalassemia major and iron overload and the subsequent development of hypothyroidism.

OBJECTIVE: Patients with beta-thalassemia frequently develop primary hypothyroidism and other endocrine disorders due to iron overload. We studied whether administration of excess iodide to patients with apparently normal thyroid function could uncover an underlying thyroid disease. DESIGN AND METHODS: Twenty-five patients, 10 prepubertal (mean age 11+/-3 years) and 15 adults (mean age 23+/-5 years) with normal thyroid hormone and TSH levels, a normal response of TSH to TRH and negative thyroid peroxidase antibodies received 20mg iodide three times daily for three weeks, and thyroid hormone and TSH levels were measured weekly during, and for three weeks after, iodide administration and every 3 months thereafter for the next 5 years. RESULTS: During iodide administration there was a significant decrease in thyroid hormone concentrations which remained within normal levels, and a significant increase in TSH concentrations which in 14 out of 25 (56%) patients reached the hypothyroid level. Baseline TSH values were higher in those patients who developed subclinical hypothyroidism (2.31+/-0.71mU/l vs 1. 34+/-0.64mU/l, P=0.0016). Subclinical hypothyroidism developed in 70% of prepubertal and in 47% of adult patients. Serum ferritin was elevated in all patients. Nine of the fourteen patients (64.3%) who developed subclinical hypothyroidism during iodide administration developed hypothyroidism during the 5-year follow-up compared with only one of the eleven patients with a normal response to iodide (P=0.004). CONCLUSIONS: Patients with beta-thalassemia should not be exposed to excess iodide due to increased sensitivity to its inhibitory effects on thyroid function. The susceptible individuals frequently develop permanent hypothyroidism in the following years.

Adolescent↗

PubMed1999

Growth and pubertal development in elite female rhythmic gymnasts.

Optimal growth depends upon both environmental and genetic factors. Among environmental factors that could alter growth and sexual maturation are stress and intensive physical training. The influence of these factors has been documented in a variety of sports, but there is limited information on rhythmic gymnasts, who have entirely different training and performance requirements. The study was conducted during the 13th European Championships in Patras, Greece, and included 255 female rhythmic gymnasts, aged 11-23 yr. The study included measurement of height and weight, assessment of breast and pubic hair development, estimation of body fat and skeletal maturation, and registration of menarcheal age and parental height. Gymnasts were taller than average height for age, with mean height above and mean weight below the 50th percentile. Actual height SD score was positively correlated to weight SD score (P < 0.001), number of competitions (P = 0.01), and body mass index (BMI; P < 0.001). Predicted adult height SD score was positively correlated to weight SD score (P < 0.001) and negatively to body fat (P = 0.004). There was a delay in skeletal maturation of 1.3 yr (P < 0.001). Pubertal development was following bone age rather than chronological age. The mean age of menarche was significantly delayed from that of their mothers and sisters (P = 0.008 and P = 0.05, respectively), was positively correlated to the intensity of training and to the difference between chronological age and bone age (P < 0.001 and P = 0.002, respectively), and was negatively correlated to body fat (P < 0.001). In the elite female rhythmic gymnasts, psychological and somatic efforts have profound effects on growth and sexual development. Despite these aberrations, adult height is not expected to be affected.

Adolescent↗

PubMed1998

The growth pattern and final height of girls with Turner syndrome with and without human growth hormone treatment.

BACKGROUND: Shortness is the most frequent and quite disturbing characteristic of girls with Turner syndrome (TS). Human growth hormone administration (hGH) to girls with TS increases growth velocity (GV), but a favorable effect on final height (FH) has not been documented. The aim of this study was to evaluate the effect of hGH administration on the growth pattern and FH in girls with TS. METHODS: The study group was comprised of 123 girls with TS who were cared for in our center. Eighty-two of these girls received hGH (mean dose, 0.78 +/- 0.12 IU/kg/week), given subcutaneously 5 to 7 times per week for a period of 2.2 +/- 1.2 years (hGH group). The mean chronological age (CA) and bone age (BA) at hGH initiation were 11.5 +/- 2.5 years and 9.7 +/- 2.3 years, respectively. The remaining 41 girls did not receive hGH and are designated as the untreated control group. In both groups, gonadal steroids were given for pubertal initiation and maintenance. RESULTS: The GV during the first year of hGH therapy (GV1) was higher than the year before hGH (6.3 cm/year vs 4.0 cm/year) and higher than the GV of the untreated group at a similar CA (4.4 cm/year). The GVs during the second (GV2) and third (GV3) year of hGH treatment (5.4 and 4.9 cm/year, respectively) were lower, but still higher in the hGH group, in comparison with the untreated group (GV2, 4.2 cm/year; GV3, 3.4 cm/year). GV1, GV2, and GV3 were negatively related to age and to BA at hGH initiation. The FH of the 35 hGH-treated girls was not significantly different from the FH of the 27 untreated girls (146.1 cm vs 144.0 cm). The Delta target height-FH was not significantly different in the two groups. The FH standard deviation score of the hGH-treated group was positively related to height standard deviation score for CA at treatment initiation (r = +0.73), maternal height (r = +0.57), target height (r = + 0.66), and birth weight (r = +0.54), but was unrelated to CA or BA at start of therapy or to hGH dose. CONCLUSIONS: hGH therapy in girls with TS, in the dose and duration of treatment applied in this study, significantly accelerated GV but did not significantly improve FH.

Body Height↗

PubMed1995

Growth hormone, insulin-like growth factor-I axis, and insulin secretion in hyperandrogenic adolescents.

OBJECTIVE: To assess GH and insulin-like growth factor I (IGF-I) axis variability in hyperandrogenic adolescents with different sources of androgen excess and their relationship with insulin resistance. DESIGN: Baseline IGF-I, insulin-like growth factor binding protein-1 (IGFBP-1), IGFBP-3, GH response to the exercise-propranolol test, and insulin responses to a standard oral glucose tolerance test were compared among patients with functional ovarian hyperandrogenism, hyperandrogenic nonfunctional ovarian hyperandrogenism patients, and age-matched controls. SETTING: Outpatient clinic in a medical center. PATIENTS: Twenty-one adolescents with ovarian (group A) and 17 with nonovarian (group B) hyperandrogenism, and 20 controls. RESULTS: Serum IGF-I and poststimulated GH levels were similar among groups, whereas serum IGFBP-3 levels were significantly lower in group A than in controls. Mean serum insulin levels were significantly higher in patients than in controls, whereas 24% of patients had abnormal insulin responses to glucose and/or insulin sensitivity indexes. Serum IGFBP-3 levels correlated negatively with the free androgen index (free androgen index = T/sex hormone-binding globulin [SHBG] x 100), whereas mean serum insulin levels correlated positively with the free androgen index and negatively with SHBG levels in all subjects. CONCLUSIONS: Hyperinsulinemia is common in hyperandrogenic adolescents and correlates with the degree of hyperandrogenism and not with the androgen source. Hyperinsulinemia and decreased IGFBP-3 levels may enhance IGF-I bioavailability, which in turn may both decrease SHBG levels and increase androgen production.

Adolescent↗

PubMed1993

Increased frequency of HLA B17 antigen in girls with Turner syndrome and their fathers.

HLA-A, -B and -DR antigen distribution was studied in 49 girls with Turner Syndrome (TS), in 43 of their parents, as well as in 433 controls. No increased frequency of DR3, DR4 was found in our group. However, an increased frequency of HLA B17 antigen was disclosed (18.3% in TS versus 6.4% in the controls, p < 0.001 and pc < 0.01). Furthermore, the HLA B17 antigen was of paternal origin in 77.7% of the cases. The interpretation of the present findings is quite difficult. Most likely, the findings are related to the chromosomal abnormality rather than to autoimmunity. It is quite possible that genes within the region of class I genes create unfavorable circumstances leading to the loss of the sex chromosome or, alternatively, genes in this region confer protection and prevent miscarriage of the affected fetus.

Fathers↗

PubMed1993

The effect of erythromycin in gastric emptying of solids and hypertonic liquids in healthy subjects.

We report our study of the effect of erythromycin on gastric emptying of solid and liquid meals in 10 healthy subjects. On different occasions, subjects consumed either a radiolabeled 50% glucose solution, or a radiolabeled standard solid meal after placebo, and after receiving 200 mg of erythromycin intravenously. Erythromycin accelerated the gastric emptying of the hypertonic liquid meal by significantly decreasing the duration of lag phase (p < 0.0001), by significantly increasing the emptying rate at the postlag period (p < 0.001), and by significantly decreasing the duration of the postlag period (p < 0.0001) and the meal remaining in the stomach at 15 (p < 0.05), 30 (p < 0.001), and 60 (p < 0.01) min postprandially. In addition, erythromycin administration induced a significant plasma fall at 15 (p < 0.05) and 30 (p < 0.01) min and a significant increase in pulse rate at 15 and 30 min (p < 0.01) after consumption of the hypertonic glucose solution, whereas three subjects experienced symptoms suggesting dumping syndrome. Furthermore, erythromycin administration enhanced the gastric emptying of solids by almost abolishing the duration of lag phase (p < 0.0001) and by reducing the overall t1/2 of emptying (p < 0.0001), whereas less food was retained in the stomach at 60 (p < 0.001) and 120 (p < 0.0001) min postprandially. Conversely, the postlag t1/2 of the solid meal emptying was not affected by erythromycin, as compared to placebo. We conclude that erythromycin has gastrokinetic properties, affecting the gastric emptying of both liquids and solids.

Adult↗

PubMedDate not supplied

Secretion of basal gonadotropins after LRH decapeptide and tripeptide. Stimulation in hypogonadotropic hypogonadism.

Sixteen females with pubertary delay of the isolated hypogonadotropic hypogonadism type (mean age 19 years, age range 14-25 years) were studied by radioimmunoassay of LH and FSH. The mean values +/- SE were compared to the values obtained from 10 girls in the B 5 Tanner stage and 15 normal adult women investigated on the 14th and 21st day of their ovarian cycle. Two females were given the LRH decapeptide and LRH-LA tripeptide stimulation test. In one case the daily variations of circulating serum LH and FSH were followed up. The fluctuations found suggest an ovarian rhythm which is present in the normal adult woman.

Adolescent↗