Nuclear DNA content and proliferative potential of human carcinoma in situ cells in testes of intersex children

Gonocytes, fetal germ cells, when persisted beyond infantile period of life are considered as preinvasive testicular germ cell cancer (carcinoma in situ--CIS). The aim of the study was to investigate nuclear DNA content and proliferative potential of CIS cells together with the expression of placental-like alkaline phosphatase (PLAP), a marker of CIS and germ cell cancer. In dysgenetic testes of 4 intersex children proliferating cell nuclear antigen (PCNA) and PLAP were examined immunohistochemically. DNA content was assessed by densitometry of nucleus in Feulgen stained histologic sections. High incidence of aneuploidy (95.1-97.6% of CIS cells with 2.6-6.8c) was found with the predominant DNA pattern of tri- and tetraploidy in children aged 1 to 3 years. The incidence of triploidy (65-78.1% of cells) was similar to the incidence of the expression of PCNA (53.4-62%), what indicates that part of hyperploid germ cells might represent phase S of cell cycle, but the rest of hyperploid cells might represent neoplastic transformation. In turn, germ cells of 8-months-old patient were predominantly diploid with low incidence of PCNA positive cells which indicate that proliferation/neoplastic transformation of abnormal germ cells is significant mostly after 1 year of age in intersex children. The frequency of PLAP expression in CIS cells (3.1-27% of cells) was weakly related to the frequency of aneuploidy what limits the usefulness of PLAP reaction for the detection of CIS cells.

Increased prevalence of celiac disease in girls with Turner syndrome detected using antibodies to endomysium and tissue transglutaminase

OBJECTIVE

To establish the prevalence of celiac disease (CD) in girls with Turner syndrome (TS) in British Columbia.

METHODS

Forty-five girls with TS were prospectively screened for CD using blinded testing with the current 'gold standard' - immunoglobulin A (IgA) endomysium antibody (EmA) and the novel IgA tissue transglutaminase antibody (tTG). Those with positive results were offered small bowel biopsies, and a gluten-free diet was recommended if CD was confirmed.

RESULTS

One asymptomatic prepubertal East Indian girl was positive for EmA, had an elevated tTG concentration of 560 U/mL and histological evidence of CD. Seven girls were negative for EmA but had elevated tTG concentrations (175 to 250 U/mL); five were white, one was Asian and one was East Indian. Small bowel biopsies were performed on three girls, and the histologies were normal. The remaining four patients declined biopsy.

CONCLUSIONS

One girl with TS was identified with CD from 45 screened, giving an overall biopsy-confirmed prevalence of 2.2%. This study confirms previous observations placing girls with TS at higher risk for CD and suggests a similar high prevalence in British Columbia.

Carbohydrate metabolism during growth hormone treatment and after discontinuation of growth hormone treatment in girls with Turner syndrome treated with once or twice daily growth hormone injections

OBJECTIVE

To assess possible side-effects of treatment with supraphysiological GH dosages on carbohydrate (CH) metabolism in girls with Turner syndrome (TS) during GH treatment until adult height is reached as well as after discontinuation of GH treatment.

DESIGN

In a prospective, randomized injection frequency-response study, the effect of GH treatment in combination with low dose ethinyl oestradiol on CH metabolism was evaluated, comparing twice daily (BID) with once daily (OD) injections of a total GH dose of 6 U/m2/day until adult height was reached.

PATIENTS

Nineteen untreated girls with TS, mean (SD) pretreatment age 13.3 (1.7) (range 11.0-17.6) year.

MEASUREMENTS

Glucose and insulin concentrations during oral glucose tolerance tests (OGTT) were measured before and during GH treatment, as well as at 6 months after discontinuation of GH treatment.

RESULTS

GH treatment was discontinued after a mean of 43 (range 27-57) months. In one of the 19 girls, a different girl at each time point before, during and after discontinuation of GH treatment, the glucose response to OGTT after 120 minutes was above 7.8 mmol/l but below 11.1 mmol/l, indicating impaired glucose tolerance. None of the girls developed diabetes mellitus. Fasting glucose levels did not significantly change during, or after discontinuation of GH treatment. The 3 h area under the curve for time-concentration adjusted for fasting levels during the OGTT for glucose showed a significant decrease during GH treatment. In contrast to the glucose levels, GH treatment induced considerably higher insulin levels compared to pretreatment values. After discontinuation of GH insulin levels decreased to values comparable with pretreatment levels. None of these observed changes were different between the GH injection frequency groups. The changes in CH variables during and after discontinuation of GH were not related to changes in body mass index.

CONCLUSIONS

GH treatment with 6 U/m2/day in combination with low dose ethinyl oestradiol in girls with Turner syndrome aged > or =11 years did not negatively influence glucose levels, but induced higher levels of insulin indicating relative insulin resistance. These changes in insulin levels were independent of the frequency of the GH injections (once vs. twice daily). After discontinuation of GH treatment, insulin values decreased to baseline levels.

Bone mineral density in Turner syndrome: relation to GH treatment and estrogen treatment

The bone mineral density (BMD) of the second metacarpal bone of the left hand was measured in 57 patients with Turner syndrome by the digital image processing (DIP) method to study the relations between the treatment regimen and their bone mineral density. BMD SD score in the patients who had started the GH treatment before 10 years old was within +/-2SD of the standard before 14 years, but the score decreased to below -2SD after 14 years. In the patients who had started GH treatment after 10 years old, BMD score were significantly lower than -2SD, although there was tendency to increased. In the patients who had estrogen after 15 years old, BMD did not increase with GH alone and slowly increased after estrogen replacement. In the other two patients who had started sex steroid hormone replacement treatment before 15 years old, BMD maintained +/-2SD. In patients who received combined GH and LH-RH analog treatment, their BMD score did not increase during LH-RH analog treatment. It slowly increased but was still below -3SD after stop of LH-RH analog and start of estrogen treatment. In Turner syndrome, GH may play a role in maintaining prepubertal BMD levels [4], and estrogen plays an important role in pubertal BMD increment. It is recommended that estrogen treatment is started before 15 years of age for maintenance of normal BMD level.

Carbohydrate metabolism during long-term growth hormone (GH) treatment and after discontinuation of GH treatment in girls with Turner syndrome participating in a randomized dose-response study. Dutch Advisory Group on Growth Hormone

To assess possible side-effects of GH treatment with supraphysiological doses on carbohydrate (CH) metabolism in girls with Turner syndrome (TS) during long term GH treatment and after discontinuation of GH treatment, the results of oral glucose tolerance tests and hemoglobin A1c measurements were analyzed in 68 girls with TS participating in a randomized dose-response trial. These previously untreated girls, aged 2-11 yr, were randomly assigned to 1 of 3 GH dosage groups: group A, 4 IU/m2 x day (-0.045 mg/kg x day); group B, first year ,4 IU/m2 day; thereafter, 6 IU/m2 x day (approximately 0.0675 mg/kg x day); group C, first year, 4 IU/m2 x day; second year, 6 IU/m2 x day; thereafter, 8 IU/m2 x day (approximately 0.090 mg/kg x day). After the first 4 yr, girls 12 yr of age or older started with 5 microg/kg BW-day 17beta-estradiol for induction of puberty. To assess the effects of long term high dose GH treatment on CH metabolism, the 7-yr data from the oral glucose tolerance tests in 9 girls of group C were evaluated (group C1). To determine whether the changes in CH metabolism during GH treatment would persist after discontinuation of GH treatment, the data for 28 girls who had reached adult height (group A, n = 9; group B, n = 10; group C, n = 9) were evaluated at baseline, after 4 yr of GH treatment, and 6 months after discontinuation of GH. Seven-year data for group C1 showed that glucose levels did not significantly change during GH treatment, whereas fasting insulin levels as well as glucose-induced insulin levels increased significantly. The data for the 28 girls who were treated with GH for a mean (SD) period of 85.3 (13.3) months demonstrated that the GH-induced higher insulin levels decreased to values close to or equal to pretreatment values after discontinuation of GH treatment. Changes in CH variables were not significantly related to the GH dose. Hemoglobin A1c levels never showed an abnormal value. The prevalence of impaired glucose tolerance was low, and none of the girls developed diabetes mellitus. In conclusion, long term GH treatment with dosages up to 8 IU/m2 x day in girls with TS has no adverse effects on glucose levels, but induced higher levels of insulin, indicating relative insulin resistance. The increased insulin levels during long term GH treatment decreased after discontinuation of GH treatment to values close to or equal to pretreatment values. Although the reversibility of the effects of long term GH is reassuring, the consequence of long term hyperinsulinism is still unknown.

Body mass index (BMI) in Turner Syndrome before and during growth hormone (GH) therapy

OBJECTIVE

To study whether body mass index (BMI) is different in girls with Turner syndrome (TS) compared to normal girls, and whether BMI in TS is affected by growth hormone (GH) treatment.

DESIGN

A retrospective cross-sectional study.

SUBJECTS

2468 girls with TS enrolled in the National Cooperative Group Study (NCGS), a collaborative surveillance study for assessing GH-treated children.

MEASUREMENTS

BMI and BMI standard deviation score (BMI SDS) at baseline and during GH treatment were computed from height and weight data.

RESULTS

BMI in TS patients increases with age as expected. However, BMI SDS increased starting at about age 9 y. A similar pattern of increase in BMI SDS was observed after each year of GH treatment for up to 4 y, but GH treatment did not change the magnitude of increase. BMI and BMI SDS curves before and during GH treatment were essentially superimposable.

CONCLUSION

These findings suggest that mechanisms specific for TS are responsible for the age-related increase in BMI SDS. This increase was unaffected by GH treatment.

Detection of TSPY protein in a unilateral microscopic gonadoblastoma of a Turner mosaic patient with a Y-derived marker chromosome

Gonadoblastomas are seen almost exclusively in dysgenetic gonads of patients with a chromosomal mosaicism of 45,X and an additional Y-bearing cell line. This paper presents a case of a Turner mosaic patient with 45,X/46,X,+mar karyotype, who developed a unilateral microscopic gonadoblastoma. Cytogenetic and molecular analysis confirmed a Y-chromosomal origin of the marker chromosome, with a deletion of the distal Yq arm and the proposed region of a so far undefined gonadoblastoma locus (GBY) present. One of the candidate genes within the postulated GBY region is TSPY (testis-specific protein Y-encoded). To study the TSPY protein expression, an anti-fusion protein antibody was used for immunohistochemistry of the patient's gonads. In contrast to the dysgenetic gonad, an intense immunoreaction was found in gonadoblastoma tumour cells of the other gonad. These results confirm the high level of TSPY protein expression by these cells and demonstrate the value of this antibody as an additional marker to confirm the diagnosis of gonadoblastoma.

[Glucose metabolism and insulin sensitivity in patients with Turner syndrome treated with growth hormone]

The authors investigated the effect of growth hormone treatment on 20 Turner syndrome patients. The aim was to assess glucose and insulin responses to oral glucose loading in 9 prepubertal and 11 pubertal patients with Turner syndrome. Thirty eight healthy subjects matched for chronological age and BMI were selected as controls. Similar glucose responses were observed in the prepubertal and postpubertal patients groups and no difference was found between patients and controls. No correlation was observed between glycaemic control of insulin sensitivity and growth hormone treatment. Although the supraphysiological doses of growth hormone did not result in substantial impairement in glucose tolerance, it is concluded that hyperinsulinaemia could be a consequence of the treatment and regular check up for glycaemic control is needed in these patients.

Endogenous growth hormone secretion does not correlate with growth in patients with Turner's syndrome. Italian Study Group for Turner Syndrome

We investigated in Turner's syndrome patients whether the decrease in growth hormone (GH) secretion is frequent or sporadic, whether or not reduced GH secretion contributes to insufficient growth, and whether age, spontaneous presence of telarche and/or pubarche, karyotype and weight influence GH secretion decrease. We evaluated GH reserve in 301 patients by classical stimulation tests and in 68 of these patients mean nocturnal spontaneous secretion was also measured. Spontaneous telarche and/or pubarche were present in 33% of girls aged > 9 years. In 11% of patients, weight was more than 20% above levels appropriate for height. In 36.2% of patients (low-responders), we observed a reduction of the GH reserve (peak < or = 10 micrograms/l during two stimulation tests). Moreover, we noted reduced mean nocturnal spontaneous secretion (< or = 3.3 micrograms/l) in 61.8% of patients. Karyotype and the presence/absence of spontaneous telarche and/or pubarche did not influence either GH reserve or mean nocturnal spontaneous secretion. GH secretion (both GH reserve and mean nocturnal spontaneous secretion) did not influence height, yet low-responders had a significantly higher chronological age than normal-responders. Obese Turner's girls were low-responders and showed reduced mean nocturnal spontaneous secretion more frequently than normal weight girls; body mass index was significantly higher in patients with reduced GH secretion when compared to patients with normal GH secretion. We conclude that impairment of GH secretion is frequent in Turner's syndrome patients, especially if obese; that GH secretion impairment is not related to karyotype or spontaneous telarche and/or pubarche; that GH secretion is irrelevant to growth in these, patients and, therefore, its evaluation is unnecessary.

Reduced androgen levels in adult turner syndrome: influence of female sex steroids and growth hormone status

BACKGROUND AND OBJECTIVES

In girls with Turner syndrome androgen levels are reduced. In order to assess androgen status in women with Turner syndrome, we compared untreated adult women with Turner syndrome with a group of normal women. In addition, the effects of female sex hormone replacement therapy and GH status on the levels of circulating androgens in Turner syndrome was examined.

DESIGN

All patients were receiving female hormone replacement therapy (HRT), which was discontinued four months prior to the initial examination. Patients were studied before and during HRT. Following the initial evaluation, patients were given cyclical HRT for six months consisting of either oral substitution (17beta-oestradiol with norethisterone from day 13-22), or transdermal oestrogen substitution (17beta-oestradiol) with 1 mg norethisterone administered orally from day 13-22. Control subjects were studied once in the early follicular stage of the menstrual cycle.

SUBJECTS

The study group consisted of 27 (33.2 +/- 7.9 years) patients with Turner syndrome and an age matched control group of 24 (32.7 +/- 7.6 years) normal women.

MEASUREMENTS

Body composition measures, SHBG, testosterone (T), free testosterone (FT), dihydrotestosterone (DHT), alpha-4-androstendione (A), dehydroepiandrosterone sulphate (DHEAS), 17beta-oestradiol (E2), oestrone (E1), oestrone sulphate (ES), 24 h integrated GH concentration (ICGH), insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein (IGFBP-3) were determined at baseline and after six months in women with Turner syndrome, and at baseline in control women.

RESULTS

Circulating levels of A, T, FT, DHT, and SHBG were reduced by 25-40% in comparison with age matched normal women. The level of DHEAS was normal. The level of E2 was undetectable and levels of E1 and ES were very low in untreated Turner women. Treatment with 17beta-oestradiol and norethisterone increased oestrogen to levels comparable to those of normal women, while further decreasing FT (P = 0.02), DHT (P = 0.04), and T (P = 0.1). In untreated women with Turner syndrome IGF-I correlated significantly with DHEAS (R = 0.503, P < 0.01), while in normal women IGF-I correlated with A (R = 0.637, P < 0.01), T (R = 0.536, P < 0.01), and FT (R = 0.700, P < 0.01). During hormonal replacement in women with Turner syndrome IGF-I correlated significantly with DHEAS (R = 0.547, P < 0.01). Employing multiple regression analysis IGFBP-3, ICGH, DHEAS and fat free mass explained 85% (adjusted R = 0.92, P < 0.0005) of the variation in the level of IGF-I in untreated Turner syndrome. In treated Turners IGFBP-3, ICGH, SHBG, T, and FT explained 78% (adjusted R = 0.88, P < 0.0005). In controls IGFBP-3, SHBG, BMI and age explained 74% (adjusted R = 0.86, P < 0.0005) of the variation in IGF-I, while GH status did not contribute at all.

CONCLUSION

The present study shows that many adults with Turner syndrome have reduced levels of circulating androgens, compared with an age-matched group of normal women. Conditions associated with Turner syndrome such as increased prevalence of sexual problems, reduced bone mineral content, osteoporosis, and an increased incidence of fractures and alterations in body composition could perhaps be alleviated or abolished by substitution with a low dose of androgens. Treatment with female hormonal replacement therapy is associated with a decrease in testosterone, free testosterone and dihydrotestosterone, possibly mediated by the androgenic effect of norethisterone. Furthermore significant differences in sex steroid levels, GH status and indices of body composition can be compatible with comparable levels of IGF-I in two very different groups of individuals.

Reduced spontaneous growth hormone secretion in patients with Turner's syndrome

We evaluated growth hormone (GH) secretion in 81 patients with Turner's syndrome (TS) (mean age 10.7+/-3.6 y) with respect to karyotype, auxological characteristics and growth response to GH treatment (1 IU/kg/wk). None of the patients had spontaneous puberty or had started replacement therapy with estrogens. Thirty-nine patients (48%) had monosomia 45X, 29 (36%) structural abnormalities of the X chromosome and 13 (16%) X mosaicism. Before the start of GH therapy, each patient underwent an evaluation of mean nocturnal GH concentration (MGHC) and 75 patients also underwent 2 pharmacological tests. MGHC of the TS patients did not differ from that of 29 prepubertal GH-deficient girls (GH peaks < 8 microg/l after pharmacological tests) and both groups were lower (p < 0.0001 and p < 0.0005, respectively) than MGHCs of 27 short normal girls (GH peak > 8 microg/l). MGHC of the patients with TS was negatively correlated (p < 0.001) with bodyweight excess (BWE) at multiple regression analysis. MGHC of the TS patients with BWE < 20% was significantly higher (p < 0.02) than that of the TS patients with BWE > 20%, but again did not differ from that of the GH-deficient patients and was lower (p < 0.001) than that of the short normal girls. MGHC did not significantly differ between the 3 groups subdivided according to karyotype. Forty-four percent of the TS patients showed GH responses to pharmacological tests < 8 microg/l. Height velocity SDS at first and second year of therapy was not influenced by MGHC levels, chronological or bone age, target height or BWE. In conclusion, spontaneous secretion in our patients with TS was lower than that of the short normal prepubertal girls and did not differ from that of GH-deficient subjects, even if we excluded overweight patients. The level of GH secretion was unable to predict GH response to treatment.

Carbohydrate and lipid metabolism during various growth hormone dosing regimens in girls with Turner syndrome. Dutch Working Group on Growth Hormone

To analyze the effects of supraphysiological dosages of growth hormone (GH) on carbohydrate (CH) and lipid metabolism, we investigated 87 girls with Turner syndrome (TS) in two studies: (1) a 4-year GH dose-response (DR) study comparing three groups with stepwise GH dosage increases up to 8 IU/m2/d in girls aged 2 to 11 years, and (2) a 2-year GH administration frequency-response (FR) study in girls aged 11 to 17 years, comparing once-daily (OD) and twice-daily (BID) injections of a total GH dose of 6 IU/m2/d in combination with low-dose ethinyl estradiol (50 ng/kg/d orally). At baseline, impaired glucose tolerance (IGT) was present in 6% of the girls, and at the end of the studies, in 5%. In the DR study, the area under the curve for time-concentration (AUCab) for glucose after an oral glucose tolerance test (OGTT) showed no change over time and no significant difference between any of the study groups. However, in all three DR groups, the AUCab for insulin, fasting glucose, the insulinogenic index, hemoglobin A1c (HbA1c), and urinary C-peptide (uCp) were all significantly higher after 4 years compared with pretreatment (P<.05). In the FR study, group differences were not observed. Compared with healthy Dutch control subjects, the median baseline levels in relatively young girls in the DR study were similar for total cholesterol (TC) and lower for high-density lipoprotein (HDL) cholesterol. In contrast, the median TC levels of relatively older girls in the FR study were higher and HDL levels were similar. With increasing GH dosage in the DR study, median TC and low-density lipoprotein (LDL) levels decreased, whereas median HDL levels increased. The changes after 4 years were significant, including a decrease in the atherogenic index. GH treatment at the supraphysiological dosages used in this study did not increase the frequency of IGT or clinical diabetes. However, we observed an increased insulinogenic index indicative of insulin resistance. Therefore, long-term follow-up study is warranted in these otherwise healthy subjects. OD injection regimens changed the lipid profile toward a more cardioprotective direction with a significant reduction of the TC/HDL cholesterol ratio.

Increased disorderliness and decreased mass and daily rate of endogenous growth hormone secretion in adult Turner syndrome: the impact of body composition, maximal oxygen uptake and treatment with sex hormones

The objectives of this study were to (1) quantify pulsatility and orderliness of 24-h growth hormone (GH) secretion in adult Turner syndrome; (2) study the impact of sex steroid replacement therapy in adult Turner syndrome on these measures of GH secretion, and in addition examine the differential effect of oral vs transdermal estrogen administration on GH secretion patterns. To these ends, we used deconvolution analysis and approximate entropy (ApEn) to quantify GH release over 24 h in 21 patients with Turner syndrome before and during sex hormone substitution, compared to an age-matched control group. Deconvolution analysis revealed that the mass of GH secreted per burst and production rate was significantly lower in Turner patients compared to controls, resulting in a significantly lower integrated 24-h GH concentration. However, multiple stepwise regression revealed that lean body mass (LBM) and maximal oxygen uptake were significant discriminative variable, explaining a large part of the variation in mass secreted per burst (r = 0.72, P < 0.0005) and production rate (r = 0.73, P < 0.0005), while group (Turner or control) did not explain any of the difference. There was a significant difference in ApEn between Turner patients and controls, denoting more disorderly GH release in Turner syndrome. During administration of sex hormones, a significant increase was seen in basal secretion and GH secretory burst half-duration, as well as in integrated 24-h GH concentration. No change in ApEn was evident. We conclude that GH secretion in adult Turner syndrome is irregular, reduced in mass and production rate. The reduction in mass and production rate could be explained by differences in body composition and maximal oxygen uptake compared to relevant controls, while the irregularity of GH secretion was unexplained by the measured variables. We hypothesize that the increased irregularity could be attributable to low levels of circulating androgens or an increased biological age in the Turner patients.

Acute metabolic effects of human growth hormone on 15N-nitrogen balance in patients with thalassaemia as compared to patients with other types of short stature

The acute response to various doses of human growth hormone (hGH) was determined in short patients with thalassaemia and compared to that in patients with classic growth hormone deficiency and Turner's syndrome. Nitrogen balance was analyzed using the stable isotope 15N. While patients with growth hormone deficiency responded with a marked nitrogen retention (+2.9 +/- 0.4 to +6.1 +/- 0.6 mg 15N/kg) to small doses of hGH (2 x 3 IU/m2), those with Turner's syndrome had a higher basal balance, but responded much less (+3.1 +/- 0.7 to +3.7 +/- 1.8 mg 15N/kg). They required a double dose of hGH (2 x 6 IU/m2) to achieve a significant retention (+4.1 +/- 1.0 to +7.1 +/- 0.4 mg 15N/kg). The thalassaemic patients responded still less than the patients with Turner's syndrome to 2 x 6 IU/m2 (+7.7 +/- 0.3 to +8.0 +/- 0.4 mg 15N/kg), and even hGH doses up to 2 x 12 IU/m2 had little effect, indicating a relative resistance to hGH. In conclusion, no or little effect is to be expected from long-term hGH treatment at low doses in thalassaemic patients. When it is decided to treat these patients, the dose should be about 4 times higher than a regular replacement dose in growth hormone deficiency.

Glucose turnover and insulin clearance after growth hormone treatment in girls with Turner's syndrome

The study was performed to elucidate, by means of a euglycemic-hyperinsulinemic clamp, whether insulin sensitivity, lipid levels, posthepatic insulin delivery, and insulin clearance are impaired in girls with Turner's syndrome in the absence of previous treatment (T0) and after 6 (T6) and 12 (T12) months of growth hormone (GH) therapy (GHT). The study was performed in six girls with Turner's syndrome and eight healthy girls. We found that previously untreated girls with Turner's syndrome had a normal insulin activity on glucose metabolism. GHT progressively and significantly decreased hepatic insulin sensitivity. In fact, residual hepatic glucose release (HGR), which was 19.6 +/- 4.7 mg/m2. min at T0, doubled at T6 (39.3 +/- 5.1 mg/m2.min) and showed a threefold increase at T12 (68.7 +/- 10.8 mg/m2.min, P < .05 v T0). On the contrary, GHT did not show an appreciable influence on peripheral insulin sensitivity. Insulin clearance was higher in girls with Turner's syndrome than in control girls at T0 (30.0 +/- 2.8 v 20.2 +/- 1.1 mL.kg-1.min-1). It decreased to normal values at T6 (18.2 +/- 2.0 mL.kg-1.min-1, P < .05 v T0) and remained at normal levels at T12 (23.8 +/- 2.9 mL.kg-1. min-1). The posthepatic insulin delivery rate significantly increased at T6 and T12, suggesting increased insulin secretion. In conclusion, we found that insulin-stimulated glucose turnover was normal in girls with Turner's syndrome before therapy. One year of GHT was successful in stimulating the growth rate, but significantly decreased the insulin suppressibility on HGR with only slight changes in peripheral insulin sensitivity. In addition, an increase in the insulin posthepatic delivery rate and a normalization of insulin clearance were present, probably to counteract hepatic insulin resistance.

Estrogen therapy enhances calcium absorption and retention and diminishes bone turnover in young girls with Turner's syndrome: a calcium kinetic study

Using stable tracers of calcium, we have previously shown a significant increase in calcium absorption and retention in prepubertal boys treated with exogenous testosterone. To investigate the effects of estrogen replacement on measures of calcium absorption, retention, and bone turnover, we studied a group of seven hypogonadal girls with Turner's syndrome (mean +/- SE age, 12.5 +/- 0.7 years). At baseline, 42Ca intravenously (IV) and 44Ca orally were administered, and blood and urine samples were collected for approximately 130 hours. Estrogen therapy was begun as oral ethinyl estradiol (4 or 20 micrograms/d) or intramuscular depot estradiol given over 4 weeks, after which an identical study was repeated. Analysis of calcium enrichment in blood and urine was performed using mass spectrometry methods. After estrogen therapy, there was a significant increase in calcium absorption ([Va] P = .03) and total calcium retention ([Vbal] P = .04), similar to the effects of testosterone in boys. Bone accretion (Vo+) decreased after estrogen therapy (P = .004), as did resorption ([Vo-] P = .004). The overall rate of whole-body calcium turnover (Vt) was significantly decreased after estrogen administration (P = .04). These findings were opposite of those observed in prepubertal boys treated with testosterone. The contribution of bone resorption to whole-body turnover (E) also decreased after estrogen therapy (P = .05). These changes were associated with increased levels of 1,25-dihydroxyvitamin D after therapy with estrogens (P = .05). We conclude that estrogen supplementation is significantly anabolic for calcium metabolism by markedly increasing calcium absorption and retention and diminishing the estimated whole-body calcium turnover in girls with severe hypogonadism and Turner's syndrome. Further studies assessing the dietary calcium and/or vitamin D intake and bone mineral density of hypogonadal girls whose estrogen replacement is intentionally delayed will further define the need for calcium or vitamin D supplements in the peripubertal years in this condition.

Decreased sensitivity to insulin-like growth factor I in Turner's syndrome: a study of monocytes and T lymphocytes

Turner's syndrome is characterized, amongst other things, by growth retardation with high serum levels of insulin-like growth factor 1 (IGF-I) in relation to growth, by a tendency to autoimmune disease and by insulin resistance with hyperlipidaemia. Assuming a role for IGF-I subresponsiveness in the last two features, the present study was designed to evaluate in patients with Turner's syndrome their monocyte/macrophage response to growth hormone (GH) and to IGF-I with respect to low-density lipoprotein (LDL) degradation and to the monocyte-dependent lymphocyte proliferation. Nineteen patients with Turner's syndrome and puberty-matched control subjects were studied. Monocytes were isolated from the blood of the patients and the control group, and cultured to develop into macrophages. The cells were then incubated with 125I-labelled LDL (25 micrograms of protein mL-1) in the absence or presence of 50 ng mL-1 IGF-I or GH, and cellular lipoprotein degradation was determined. GH and IGF-I effects on T-cell proliferation were measured in autologous mixed lymphocyte reaction Monocytes/macrophages degradation of LDL was lower in Turner's syndrome patients than in control subjects (P < 0.05). IGF-I stimulated LDL degradation by 42 +/- 8% in the control subjects and by only 16 +/- 7% in Turner's syndrome patients (P < 0.05). Control lymphocyte proliferation in AMLR was significantly augmented by 50-100 ng mL-1 GH or IGF-I. Lymphocytes derived from peripheral blood of Turner's syndrome patients remained almost unaffected by either GH or IGF-I. Measurement of IL-2 secretion by purified blastoid T lymphocytes-I. revealed a significant augmentation by 100 ng mL-1 GH and by 50-100 ng mL-1 IGF-I in control subjects, and almost no response in Turner's0 ng syndrome. Turner's syndrome is associated with decreased sensitivity of peripheral blood mononuclear cells to GH and to IGF-I, as is evident by the reduction in LDL degradation, monocyte-stimulated T-lymphocyte proliferation and IL-2 secretion by blastoid T cells.

Insulin-like growth factors (IGF-I and IGF-II) and IGF-binding protein-3 production by fibroblasts of patients with Turner's syndrome in culture

Reports indicate that in plasma insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) are normal in patients with Turner's syndrome (TS). The aim of our study was to evaluate both the spontaneous and the stimulated synthesis of these peptides by mesenchymal cells obtained from skin biopsies of patients affected with TS. We compared the ability of fibroblasts from six TS patients with that of fibroblasts from six age-matched control (C) subjects to synthesize in vitro IGF-I, IGF-II, and IGFBP-3 under basal and GH-, estradiol (E2)-, or GH- plus E2-stimulated conditions. Furthermore, we evaluated IGF-I, IGF-II, and IGFBP-3 messenger ribonucleic acid (mRNA) expression in fibroblasts from TS and C subjects. Fibroblasts obtained from TS patients release into the medium significantly lower amounts of IGF-I and IGF-II than C fibroblasts (P = 0.0435 and 0.0318, respectively). In TS fibroblasts, GH and E2 are able to induce a similar increase, although not significant, of IGF-I secretion into the medium (163 +/- 75% and 112 +/- 41% of control values). On the contrary, in C fibroblasts, GH is more effective (275 +/- 61%; P = 0.0277) than E2 (75 +/- 46%). In both cell lines, GH and E2 do not significantly modify IGF-II release. Interestingly, the medium conditioned by fibroblasts from TS contains, under basal conditions, significantly higher amounts (273 +/- 79 ng/1 x 10(6) cells) of IGFBP-3 than that from control fibroblasts (67 +/- 19 ng/1 x 10(6) cells; P = 0.0191). GH exerts a stimulatory effect, although it is not statistically significant, on IGFBP-3 secretion, particularly in control fibroblasts. By contrast, the effect of E2 is inhibitory in all TS fibroblast cell lines, although it does not reach statistical significance (P = 0.067). In agreement with these data, a reduced mRNA expression of the genes encoding for IGF peptides was evident in TS fibroblasts, whereas no significant difference could be demonstrated for IGFBP-3 mRNA. The results suggest a reduced autocrine/paracrine action of IGFs in TS and indicate that skin fibroblast cultures can give information on the local responsiveness to the treatment.

Undiagnosed morbidity in adult women with Turner's syndrome

OBJECTIVE

Adult patients with Turner's syndrome are rarely followed up at specialist clinics after discharge from paediatric care but do have a predisposition to several long-term medical problems. We have assessed the undiagnosed morbidity that exists among adult women with Turner's syndrome.

PATIENTS

A group of 32 women (age range 17-52 years; mean 25 years) attending a specialist out-patient clinic.

MEASUREMENTS

Blood samples were obtained at the initial visit for lipid assessment, thyroid function, gonadal status and routine biochemical profile. Bone mineral density (BMD) was measured in 31 of the women.

RESULTS

Thirty-one women were receiving some form of oestrogen replacement. Two were receiving T4 therapy. In 50%, total cholesterol was greater than 5.2 mmol/l (range 3.4-9.3 mmol/l, mean 5.8 mmol/l) and 28% had an abnormality of thyroid function tests. Two women were newly diagnosed as hypothyroid, 6 had compensated hypothyroidism and one was under-replaced with T4. Lumbar spine BMD was below 100% of age matched reference range in 84% and below 75% in 26% of patients. Femoral neck BMD was below 100% of age matched reference range in 90% and below 75% in 10% of patients.

CONCLUSIONS

There is a high incidence of undiagnosed lipid, thyroid and bone mineral density abnormalities in the adult population with Turner's syndrome. Doctors caring for these women need to be aware of and look for the potential problems. Appropriate long-term treatment should be commenced to help prevent the development of lipid, skeletal and thyroid abnormalities which may cause these patients major problems in the future.

Carbohydrate metabolism in children receiving growth hormone for 5 years. Chronic renal insufficiency compared with growth hormone deficiency, Turner syndrome, and idiopathic short stature. Genentech Collaborative Group

Carbohydrate metabolism was evaluated by fasting and postprandial glucose, insulin, and hemoglobin (Hb)Alc levels in children with chronic renal insufficiency and various other growth disorders treated with growth hormone. Mean fasting and postprandial glucose remained unchanged throughout the 5-year study period in all four study groups. Median fasting insulin levels rose from low-normal levels into the normal range after 5 years of growth hormone. Average fasting insulin level after 5 years was 10 mU/l. Median postprandial insulin values also rose, yet remained within the normal range at the 5-year mark. Mean Hb Alc levels remained within low to middle end of the normal range in the patients with growth hormone deficiency, Turner syndrome, and idiopathic short stature. Mean Hb Alc levels at the 5 years were slightly elevated to 6.3% for the patients with chronic renal insufficiency.

[Changes in bone metabolism in girls with Turner's syndrome]

BACKGROUND

Data of the prevalence of osteoporosis in girls with Turner's syndrome are not uniform, and its causes have not been fully elucidated. Information on the mineralization of osseous tissue is controversial. The objective of the present work was to examine some more recent indicators of bone metabolism in a group of girls with Turner's syndrome.

METHODS AND RESULTS

A group of girls aged 4-20 years was examined where genetic examination had revealed karyotype 45 X (7 patients) or mosaic 45 X (46 XX) (9 patients). On X-ray examination osteoporosis was found in 71%, densitometric evidence of reduced bone density was provided in 2% of the examined patients. As to biochemical osteologically oriented examinations, a significantly reduced osteocalcin value was found (1.18 +/- 0.42 mug/l, as compared with 11.38 +/- 0.03 in controls, p < 0.001), reduced values of alkaline phosphatase (2.67 mukat/l as compared with 8.46 +/- 4.16 mukat/l in controls, p < 0.005) and reduced values of the bone isoenzyme of alkaline phosphatase (1.47 mukat/l as compared with 6.04 +/- 0.27 in controls, p < 0.001). The values of calcemia (2.63 / 0.13 mmol/l) and phosphataemia (1.36 +/- 0.25 mmol/l) did not differ significantly from values recorded in controls. To six patients the authors administered for a period of three months 1,25(OH)2D3, 0.25 mg on alternate days. The osteocalcin values rose to 5.27 +/- 3.14 micrograms/l, similarly as alkaline phosphatase (6.32 +/- 1.83 mukat/l) and the bone isoenzyme of alkaline phosphatase (2.42 +/- 1.95 mukat/l), not evaluated statistically because of the small number of patients.

CONCLUSIONS

In girl with Turner's syndrome a reduced bone density was revealed in 25%, reduced values of osteocalcin, alkaline phosphatase and its bone isoenzyme indicate a reduced osteoblast activity. It appears that administration of 1,25(OH)2D3 can have a favourable effect.

Lack of X inactivation associated with maternal X isodisomy: evidence for a counting mechanism prior to X inactivation during human embryogenesis

We have previously reported functional disomy for X-linked genes in females with tiny ring X chromosomes and a phenotype significantly more abnormal than Turner syndrome. In such cases the disomy results from failure of these X chromosomes to inactivate because they lack DNA sequences essential for cis X inactivation. Here we describe a novel molecular mechanism for functional X disomy that is associated with maternal isodisomy. In this case, the severe mental retardation and multiple congenital abnormalities in a female with a mosaic 45,X/ 46,X,del(X)(q21.3-qter)/ 46X,r(X) karyotype are associated with overexpression of the genes within Xpter to Xq21.31 in many of her cells. Her normal X, ring X, and deleted linear X chromosomes originate from the same maternal X chromosome, and all are transcriptionally active. None expresses X inactive specific transcript (XIST), although the locus and region of the putative X inactivation center (XIC) are present on both normal and linear deleted X chromosomes. To our knowledge, this is the first report of a functional maternal X isodisomy, and the largest X chromosome to escape inactivation. In addition, these results (1) show that cis inactivation does not invariably occur in human females with two X chromosomes, even when the XIC region is present on both of them; (2) provide evidence for a critical time prior to the visible onset of X inactivation in the embryo when decisions about X inactivation are made; and (3) support the hypothesis that the X chromosome counting mechanism involves chromosomal imprinting, occurs prior to the onset of random inactivation, and is required for subsequent inactivation of the chromosome.

Estrogens do not affect whole-body protein metabolism in the prepubertal female

The increase in bone mass, muscle bulk, and linear growth that occur during puberty are mediated, at least in part, through the action of sex steroids. By using infusions of nonradioactive tracers of leucine, we have recently shown a significant protein anabolic effect of testosterone in prepubertal boys. The present study was designed to determine whether estrogens can cause similar changes in protein metabolism in females. Seven prepubertal girls (Turner's syndrome, n = 6; hypogonadotropism, n = 1; mean age 12.2 +/- 0.3 yr) were studied. A 4-h infusion of L(-)[1-(13C)]leucine was given, and the isotopic enrichment of [13C]ketoisocaproic acid and 13CO2 were measured in plasma and in breath with use of gas chromatography/mass spectroscopy and an isotope ratio mass spectrometer, respectively. The reciprocal pool model was used for analysis of leucine kinetics. Subjects were then started on ethinyl estradiol orally (n = 5) or depot estradiol parenterally (n = 2). An identical study was repeated 4 weeks later. There were comparable changes in leucine kinetics in all girls studied, hence their data were grouped for analysis. After administration of ethinyl estradiol, there were insignificant changes in the rate of appearance of leucine, an index of proteolysis (+6% +/- 8%); leucine oxidation (-9% +/- 11%); and nonoxidative leucine disposal, an index of whole body protein synthesis (+10% +/- 8%). This is in sharp contrast to the changes found in boys studied similarly after treatment with testosterone (rate of appearance: 17 +/- 6%, P = .036; leucine oxidation -49 +/- 5%, P = 0.004; and nonoxidative leucine disposal +35 +/- 8%, P = 0.009). The lack of anabolic effect on whole-body protein in the girls reported here was observed despite significant increases in plasma insulin-like growth factor I concentrations during 4 h of sampling when comparing the 2 study days, similar to that of the prepubertal boys who were treated with testosterone. In summary, we observed that contrary to androgens, estrogens do not alter estimates of whole-body protein turnover and anabolism in prepubertal humans, despite significant increases in circulating insulin-like growth factor I concentrations. In conclusion, the impact of testosterone on protein metabolism seems to be a direct effect of androgens, independent of aromatization. These findings correlate with the significant differences in muscle bulk between the sexes as children go through puberty.