Tziminema unachi n. gen., n. sp. (Nematoda: Strongylidae: Strongylinae) parasite of Baird's tapir Tapirus bairdii from Mexico.

A new genus and species of nematode, Tziminema unachi n. gen., n. sp. is described from the caecum and colon of Baird's tapir Tapirus bairdii (Gill, 1865), found dead in the Reserva de la Biósfera El Triunfo, Chiapas State, in the Neotropical realm of Mexico. Tziminema n. gen. differs from the other nine genera included in the Strongylinae by two main characteristics: having 7-9 posteriorly directed tooth-like structures at the anterior end of the buccal capsule, and the external surface of the buccal capsule being heavily striated. Phylogenetic analyses of the DNA sequences of the mitochondrial cytochrome c oxidase and nuclear DNA, including a partial sequence of the internal transcribed spacer 1, 5.8S and a partial sequence of the internal transcribed spacer 2 of the new taxon, confirmed its inclusion in Strongylinae and its rank as a new genus.

Temporal changes of selected chemical properties in three manure - amended soils of Hawaii.

Soil amendment with organic materials (crop residues animal manure, and green manure) reportedly has positive effects on soil properties, from acidity to plant-nutrient availability. To examine that hypothesis, an incubation study was conducted to assess the changes in some chemical properties of three different tropical soils (Andisol, Ultisol, and Oxisol) amended with chicken manure and green manure (Leucaena leucocephala) at the rate of 10tha(-1). The results showed that organic amendments raised soil pH and EC, regardless of the type of manure used. Manuring lowered the concentrations of Mehlich-3 extractable Ca, P, Mn and Si in all soils and decreased the concentration of Mg in the Ultisol and Oxisol. However, manure amendment led to increases in the concentrations of Mg and K in the Andisol. Organic amendments caused a decrease in KCl extractable Al. Initial soluble C levels were highest in the Oxisol (60micromolg(-1)) and lowest in the Andisol (20micromolg(-1)). The concentration of soluble C decreased exponentially with duration of incubation. Three low molecular weight organic molecules (acetic acid, catechol and oxalic acid) out of the eight tested were found in all manure-amended soils. This study quantified the release of some Al chelating organic acids, the reduction of exchangeable Al, and the changes in major plant-nutrients when organic materials were added to nutrient poor, tropical acid soils.

Body mass index in girls with idiopathic central precocious puberty during and after treatment with GnRH analogues.

BACKGROUND: In girls with Idiopathic Central Precocious Puberty (ICPP) concern has been raised by the potential impact of GnRH-analogues (GnRHa) treatment on body weight. We evaluated the effect of GnRHa on Body Mass Index (BMI) in girls with ICPP according to weight status at diagnosis. METHODS: One hundred seventeen ICPP girls were divided according to pretreatment weight status in: normal weight (NW), overweight (OW) and obese (OB). BMI at one and two years of treatment was assessed. BMI-SDS of 60 patients who reached adult height (AH) was compared to that of 33 ICPP untreated girls. RESULTS: NW girls significantly increased their baseline BMI-SDS at 1 and 2 years of treatment. OW girls only had a significant increment at one year of treatment while OB girls showed no BMI-SDS change. Patients evaluated at AH (at least four years after GnRHa withdrawal) showed a significant decrease on BMI compared to baseline and a significantly lower BMI than the untreated group. CONCLUSION: In ICPP girls the BMI increase under GnRHa was inversely related to the pretreatment weight status. In the long term follow-up, no detrimental effect of GnRHa on body weight was observed. BMI-SDS was lower in treated than in untreated girls.

Growth in Turner's syndrome: long term treatment with low dose ethinyl estradiol.

The growth response to 100 ng/kg BW X day ethinyl estradiol (2-4 micrograms/day) given for 18 months was studied in a group of nine patients with Turner's syndrome, aged 8.6-13.3 yr. All patients were prepubertal and had elevated gonadotropin levels. Growth velocity increased from 3.09 +/- 1.05 (+/-SD) to 7.09 +/- 1.47 cm/yr in the first 6 months, 6.08 +/- 1.78 cm/yr in the second 6 months, and 4.03 +/- 1.65 cm/yr in the third 6 months. Bone age increased a mean of 0.82 +/- 0.34, 0.89 +/- 0.79, and 0.74 +/- 0.59 yr, respectively, in the three 6-month periods. Predicted height prognosis did not change after any period. All patients had pubertal changes, limited in most to slight breast development. Mean diurnal spontaneous GH secretion did not change during treatment. Plasma somatomedin-C levels were low before treatment, and ethinyl estradiol did not significantly increase somatomedin-C values. Our data confirm the ability of a low dose of ethinyl estradiol to increase growth velocity in girls with Turner's syndrome, although the effect diminished with time, and the excess bone age advancement precluded improvement of predicted height.

Inhibition of follicle-stimulating hormone receptor binding by circulating immunoglobulins.

We have characterized a circulating inhibitor of FSH receptor binding found in two patients with hypergonadotropic amenorrhea and myasthenia gravis. The inhibitor behaves as an immunoglobulin according to several criteria, including precipitation by 30% ammonium sulfate, migration on DEAE-cellulose chromatography, specific binding to protein A-Sepharose, characterization as a 7S protein in sucrose density gradients, and immunoprecipitation with specific antihuman immunoglobulin G. Evidence suggests that these antibodies are directed at determinants on or near the FSH receptor, and they may be responsible for the observed clinical FSH resistance.

Estrogen priming effect on growth hormone (GH) provocative test: a useful tool for the diagnosis of GH deficiency.

We have studied the effect of estradiol (E2) on the GH-insulin-like growth factor (GH-IGF) axis in 15 prepubertal GH deficiency (GHD) children and 44 prepubertal or early pubertal children with idiopathic short stature (SS). All of them received a daily dose of micronized E2 (1 or 2 mg) or placebo, for 3 days, before a sequential arginine-clonidine test. In SS children, GH maximal responses were 17.8+/-10.9 on placebo and 27.9+/-14.5 microg/L on estrogen (P < 0.0001). The lower 95% confidence limits for GH maximal response changed from 3.7 microg/L (without E2) to 8.3 microg/L (on E2). In GHD children, no significant stimulatory effect of estrogen on GH levels was observed. After placebo, a cut-off limit of 3.7 microg/L (the lower 95% confidence interval limit) resulted in 73% sensitivity, 95% specificity, and an overall 90% diagnostic efficiency. After E2, a cut-off limit of 8.3 microg/L resulted in a sensitivity of 87%, a specificity of 98%, and a diagnostic efficiency of 95%. After placebo, 68% of SS showed normal IGF-I levels, and the mean did not change on E2 (13.7+/-6.3 vs. 14.3+/-6.8 nmol/L, not significant). In 93% of SS, IGF binding protein (IGFBP)-3 levels were normal during placebo. On E2, mean IGFBP-3 did not change (2.63+/-0.70 vs. 2.70+/-0.70 mg/L, not significant). In 14 of 15 GHD patients, IGF-I values were below normal on placebo, and the mean of the group did not change after E2. During placebo, 13 of 15 GHD children presented low IGFBP-3 values. During E2, there was a small significant increase in IGFBP-3 values (1.06+/-0.58 vs. 1.20+/-0.69 mg/L, P < 0.02). The highest diagnostic efficiencies for IGF-I and IGFBP-3 were observed during placebo (75% and 91%, respectively). We conclude that GH stimulation tests after E2 priming had the highest diagnostic efficiency. Our findings suggest that the effect of estrogen priming on GH stimulated levels, by reducing the number of false nonresponders, might be useful to better discriminate between normal and abnormal GH status in SS children.

Disruption of the joint synchrony of luteinizing hormone, testosterone, and androstenedione secretion in adolescents with polycystic ovarian syndrome.

The present study explores the postulate that the polycystic ovarian syndrome (PCOS) is marked by failure of physiological feedforward and feedback signaling between pituitary LH and ovarian androgens. To this end, we appraised the 3-fold simultaneous overnight release of LH (assayed by high precision immunofluorometry), testosterone (RIA), and androstenedione (RIA) in 12 an- or oligoovulatory adolescents with PCOS (mean +/- SEM age, 16.4 +/- 0.47 yr) and 10 eumenorrheic girls (age, 16.5 +/- 0.45 yr). Gynecological (postmenarchal) ages (years) were also comparable at 4.8 +/- 0.39 (PCOS) and 4.0 +/- 3.6 (control; P = NS). Body mass index and fasting serum insulin and estradiol concentrations were indistinguishable in the two study cohorts. Mean overnight serum concentrations of LH (assayed by both immunofluorometry and Leydig cell bioassay), testosterone, androstenedione, and 17alpha-hydroxyprogesterone were each elevated significantly in patients with PCOS (all P

Disruption of the synchronous secretion of leptin, LH, and ovarian androgens in nonobese adolescents with the polycystic ovarian syndrome.

The present study probes putative disruption of hypothalamic control of multihormone outflow in polycystic ovarian syndrome by quantitating the joint synchrony of leptin and LH release in adolescents with this syndrome and eumenorrheic controls. To this end, hyperandrogenemic oligo- or anovulatory patients with polycystic ovarian syndrome (n = 11) and healthy girls (n = 9) underwent overnight blood sampling every 20 min for 12 h to monitor simultaneous secretion of leptin (immuno-radiometric assay), LH (immunofluorometry), and androstenedione and T (RIA). Synchronicity of paired leptin-LH, leptin-androstenedione, and leptin-T profiles was appraised by two independent bivariate statistics; viz., lag-specific cross-correlation analysis and pattern-sensitive cross-approximate entropy. The study groups were comparable in chronological and postmenarchal age, body mass index, fasting plasma insulin/glucose ratios, and serum E2 concentrations. Overnight mean (+/- SEM) serum leptin concentrations were not distinguishable in the two study groups at 30 +/- 4.8 (polycystic ovarian syndrome) and 32 +/- 7.4 microg/liter (control). Serum LH concentrations were elevated at 9.5 +/- 1.4 in girls with polycystic ovarian syndrome vs. 2.8 +/- 0.36 IU/liter in healthy subjects (P = 0.0015), androstenedione at 2.8 +/- 0.30 (polycystic ovarian syndrome) vs. 1.2 +/- 0.11 ng/ml (control) (P = 0.0002), and T at 1.56 +/- 0.29 (polycystic ovarian syndrome) vs. 0.42 +/- 0.06 ng/ml (P < 0.0001). Cross-correlation analysis shows that healthy adolescents maintained a positive relationship between leptin and LH release, wherein the latter lagged by 20 min (P < 0.01). No such association emerged in girls with polycystic ovarian syndrome. In eumenorrheic volunteers, leptin and androstenedione concentrations also covaried in a lag-specific manner (0.0001 < P < 0.01), but this linkage was disrupted in patients with polycystic ovarian syndrome. Anovulatory adolescents further failed to sustain normal time-lagged coupling between leptin and T (P < 0.01). Approximate entropy calculations revealed erosion of orderly patterns of leptin release in polycystic ovarian syndrome (P = 0.012 vs. control). Cross-entropy analysis of two-hormone pattern regularity disclosed marked disruption of leptin and LH (P = 0.0099), androstenedione and leptin (P = 0.0075) and T-leptin (P = 0.019) synchrony in girls with polycystic ovarian syndrome. In summary, hyperandrogenemic nonobese adolescents with oligo- or anovulatory polycystic ovarian syndrome manifest: 1) abrogation of the regularity of monohormonal leptin secretory patterns, despite normal mean serum leptin concentrations; 2) loss of the bihormonal synchrony between leptin and LH release; and 3) attenuation of coordinate leptin and androstenedione as well as leptin and T output. In ensemble, polycystic ovarian syndrome pathophysiology in lean adolescents is marked by vivid impairment of the synchronous outflow of leptin, LH and androgens. Whether analogous disruption of leptin-gonadal axis integration is ameliorated by therapy and/or persists into adulthood is not known.

A preponderance of basic luteinizing hormone (LH) isoforms accompanies inappropriate hypersecretion of both basal and pulsatile LH in adolescents with polycystic ovarian syndrome.

We recently demonstrated that adolescent girls with polycystic ovarian syndrome (PCOS) exhibit augmented LH secretion due to an increase in immunofluorometric and deconvolution-estimated LH secretory burst mass and pulse frequency. Concurrently, we inferred either a prolongation of apparent (endogenous) LH half-life or elevated basal (nonpulsatile) LH release in PCOS. The in vivo half-life of LH molecules can be affected by the oligosaccharide side-chains, which also modify in vitro bioactivity and electrostatic change. Accordingly, as a surrogate estimator of altered endogenous LH half-life and/or biopotency in PCOS, we characterized the isoelectric properties of secreted LH isoforms and determined their in vitro biological activity in adolescent girls with PCOS compared with healthy age-matched eumenorrheic controls. To this end, 12-h (overnight) serum samples from PCOS patients (n = 12) and normal adolescents (n = 10) were pooled by subject. Bioactive LH concentrations were then quantitated in a rat Leydig cell in vitro bioassay, and immunological activity was determined by immunofluorometry. The distribution of LH isoforms was evaluated by preparative chromatofocusing (pH window, 10.5 to <4.0) of samples further combined to yield three independent serum pools for each of the patient and control groups. Fasting serum concentrations of 17-hydroxyprogesterone (17-OHP), androstenedione, testosterone, estrone, estradiol, and sex hormone-binding globulin were determined as possible endocrine correlates of LH isotypes. Mean serum concentrations of immunoreactive and bioactive LH in adolescents with PCOS were 3 and 2 times higher than values in controls: immunoreactive: PCOS, 7.8+/-0.9; controls: 2.6+/-0.3 IU/L (P < 0.001); and bioactive: PCOS, 52+/-10; controls, 25+/-4.1 IU/L (P = 0.002), respectively. Bioactive LH concentrations correlated positively with 17-OHP (P = 0.022), androstenedione (P = 0.012), and testosterone (P = 0.046) concentrations in PCOS. Chromatofocusing of LH isoforms disclosed greater LH immunoreactivity at pI values greater than 8 and 7.99-7.0 in adolescents with PCOS compared with controls (P = 0.031). The percentage of basic LH isoforms was related positively to serum concentrations of 17-OHP (P = 0.032), androstenedione (P = 0.046), and testosterone (P = 0.040). In conclusion, the present isotype analysis demonstrates elevated in vitro LH bioactivity and a preponderance of basic LH isoforms in girls with PCOS. Since previously reported heterologous in vivo assays of LH kinetics point toward accelerated removal of such alkaline isotypes, our findings would favor the earlier alternative hypothesis of inappropriate hypersecretion of basal (interpulse) LH rather than prolongation of the LH half-life as the mechanism for elevated interpulse serum LH concentrations in adolescents with PCOS. In ensemble, the foregoing data thus suggest 3-fold amplification of basal LH secretion as well as both a heightened amplitude and frequency of the pulsatile mode of LH release in PCOS.

Augmented frequency and mass of LH discharged per burst are accompanied by marked disorderliness of LH secretion in adolescents with polycystic ovary syndrome.

The aim of this study was to quantify pulsatile LH secretion, burst frequency and mass, LH half-life, and the approximate entropy (ApEn) or (dis-) orderliness of LH release in adolescents with polycystic ovary syndrome (PCOS), combining a high-precision immunofluorimetric LH assay with deconvolution techniques. We sampled LH concentration profiles every 20 min overnight in 12 girls with PCOS (mean +/- S.E.M. age 16.4+/-0.57 years, body mass index (BMI) 24.4+/-1.6 kg/m2) and 11 eumenorrheic early-follicular-phase controls (mean +/- S.E.M. age 16.5+/-0.47 years, BMI 22.2+/-1.0 kg/m2). Fasting serum levels of androstenedione, testosterone, 17-hydroxyprogesterone (17-OHP), estrone, estradiol, FSH and sex hormone-binding globulin (SHBG) were determined. Compared with euandrogenic girls, PCOS adolescents had significantly (P<0.005) elevated serum LH/FSH ratios, 17-OHP, androstenedione, esterone and testosterone levels, decreased SHBG, and similar estradiol. PCOS subjects exhibited a 3-fold higher mean serum LH concentration with almost no overlap with controls (8.8+/-1.2 and 2.8+/-0.3 IU/l respectively, P<0.001). We initially used a conventional serum hormone concentration peak analysis method (Cluster) to evaluate the characteristics of pulsatile LH release. Cluster analysis disclosed a significant increase in serum LH concentration maximal peak height, a higher LH peak frequency and a higher mean serum LH concentration in interpulse nadirs in the PCOS group. Deconvolution analysis of mechanisms underlying the foregoing showed higher frequency in the PCOS group than the controls (7.9+/-0.4 and 5.7+/-0.6 pulses/12 h respectively, P<0.05). The mass of LH released per secretory event was also significantly higher in PCOS subjects than controls (5.4+/-0.57 and 3.4+/-0.56 IU/l respectively, P<0.05). Since the pulsatile production rate is the product of the mean mass of hormone secreted per pulse and the number of pulses per day, we estimated a significantly higher mean pulsatile production rate of (endogenous) LH in the PCOS group (41+/-4.2 IU/l per day in the PCOS group vs 18+/-2.3 IU/l per day in the controls, P<0.01). The mean estimated half-life of endogenous LH disappearance was also significantly higher in patients with PCOS than in controls (110+/-8.5 and 77+/-3.7 min respectively, P<0.01). To quantify the orderliness of LH release, we used ApEn. PCOS patients had remarkably increased disorderliness (higher ApEn) of LH release (1.09+/-0.04 vs 0.77+/-0.08 in controls, P = 0.002). Mean serum LH concentration, mass of LH secreted per burst, and LH production rate in PCOS, but not in normal adolescents, correlated positively with androstenedione (P<0.02, 0.02 and 0.05 respectively). The same parameters also correlated positively with 17-OHP (P<0.05, 0.02 and 0.05 respectively). Stepwise regression analysis unmasked a negative influence of BMI in PCOS on both mass of LH secreted per burst (r = -0.77, P<0.005) and LH production rate (r = -0.70, P<+/0.01). We conclude that PCOS adolescents secrete LH molecules with amplified frequency and burst mass and with markedly disrupted orderliness. A rise in basal (non-pulsatile) LH release, more basic LH isoforms, and/or a prolongation or asymmetry of the LH secretory burst could account for the apparently prolonged LH half-life. Determining whether disorderliness of the amplified pituitary LH release process is an intrinsic abnormality in PCOS. or reflects androgen excess, may help to clarify the pathophysiology of this oligo-ovulatory syndrome in young women.

Persistence of autonomous ovarian activity after discontinuation of therapy for precocious puberty in McCune-Albright syndrome.

OBJECTIVE: The aim of this study was to evaluate the possibility of persistence of autonomous ovarian activity in girls with McCune-Albright syndrome (MAS) after withdrawal of medroxyprogesterone therapy administered for precocious puberty. DESIGN, SETTING, AND PARTICIPANTS: Five girls with MAS were followed-up 1.2 to 8.5 years after the end of treatment. The girls underwent luteinizing hormone-releasing hormone (LH-RH) tests, estradiol (E2) basal measurement, and pelvic ultrasound two times in the follow-up period. RESULTS: Menses resumed in four of five girls, 1.4 +/- 0.9 years after the end of treatment, at chronologic age of 11.3 +/- 1.3 years. Cycles for all girls were irregular. Three patients presented inadequate E2 levels (from 56 to 320 pg/mL) associated with low or absent gonadotropin response to LH-RH tests. The pelvic ultrasound showed ovarian cysts at the time of the study. CONCLUSION: These hormonal and ultrasonographic findings provide evidence of persistence of autonomous ovarian activity in some young women with MAS.

[Molecular analysis of the most frequent mutations associated with congenital adrenal hyperplasia secondary to 21-hydroxylase enzyme deficiency]. / Análisis molecular de las mutaciones más frecuentes asociadas a la hiperplasia suprarrenal congénita por déficit de la enzima 21 hidroxilasa.

Most cases (90%) of congenital adrenal hyperplasia (CAH) are secondary to steroid 21-hydroxylase enzyme deficiency (P450c21). In human, the P450c21 gene (CYP21B) is present along with a non functional pseudogene (CYP21A). These genes, located in chromosome 6, present a sequence homology of 98%. This high homology and the complexity of this gene locus brings about considerable difficulties in its molecular analysis and in the interpretation of the results. The aim of the present study was to elaborate an adequate strategy for the analysis of the most frequent mutations described in the CYP21B gene. A total of 77 patients with clinical and biochemical diagnosis of CAH secondary to P450c21 enzyme deficiency, as well as 170 unaffected relatives, were studied. They belonged to 73 unrelated families (146 chromosomes). The strategy allowed for the differentiation of patients with homozygous point mutations (PM), with PM in one allele and deletions, conversions, Ex3 or Cluster Ex6 PM in the other, even though parents were not always available for the study. Furthermore, it allowed for the discrimination of heterozygous deletions or conversions of the CYP21B gene from duplications of the non functional gene CYP21A, as well as CYP21B and A deletions from normal copies of the two genes. An exhaustive molecular analysis of this gene is necessary for an adequate characterization of the alterations present in this locus.

Anemia versus disease activity as cause of fatigue in rheumatoid arthritis.

BACKGROUND: Fatigue is a common complaint in rheumatoid arthritis patients and contributes to loss of quality of life. OBJECTIVE: To study the influence of hemoglobin levels and disease activity index upon fatigue in patients with rheumatoid arthritis (RA). METHODS: We studied 130 RA patients for DAS 28, hemoglobin levels and fatigue as measured by FACIT F. RESULTS: No association between fatigue with hemoglobin levels was observed. A positive association with DAS-28 was found. Decomposing DAS-28, no association could be detected with sedimentation rate but a positive correlation with analogical scale for general health, number of swollen and painful joints was found. CONCLUSION: Although a positive association of fatigue with DAS-28 is found it appears that the most important items in connection with fatigue are swollen and tender joints as well as general health status. Hemoglobin levels were not related to fatigue in our patients.

Mutations of the KISS1 gene in disorders of puberty.

CONTEXT: Kisspeptin, encoded by the KISS1 gene, is a key stimulatory factor of GnRH secretion and puberty onset. Inactivating mutations of its receptor (KISS1R) cause isolated hypogonadotropic hypogonadism (IHH). A unique KISS1R-activating mutation was described in central precocious puberty (CPP). OBJECTIVE: Our objective was to investigate KISS1 mutations in patients with idiopathic CPP and normosmic IHH. PATIENTS: Eighty-three children with CPP (77 girls) and 61 patients with IHH (40 men) were studied. The control group consisted of 200 individuals with normal pubertal development. METHODS: The promoter region and the three exons of KISS1 were amplified and sequenced. Cells expressing KISS1R were stimulated with synthetic human wild-type or mutant kisspeptin-54 (kp54), and inositol phosphate accumulation was measured. In a second set of experiments, kp54 was preincubated in human serum before stimulation of the cells. RESULTS: Two novel KISS1 missense mutations, p.P74S and p.H90D, were identified in three unrelated children with idiopathic CPP. Both mutations were absent in 400 control alleles. The p.P74S mutation was identified in the heterozygous state in a boy who developed CPP at 1 yr of age. The p.H90D mutation was identified in the homozygous state in two unrelated girls with CPP. In vitro studies revealed that the capacity of the P74S and H90D mutants to stimulate IP production was similar to the wild type. After preincubation of wild-type and mutant kp54 in human serum, the capacity to stimulate signal transduction was significantly greater for P74S compared with the wild type, suggesting that the p.P74S variant is more stable. Only polymorphisms were found in the IHH group. CONCLUSION: Two KISS1 mutations were identified in unrelated patients with idiopathic CPP. The p.P74S variant was associated with higher kisspeptin resistance to degradation in comparison with the wild type, suggesting a role for this mutation in the precocious puberty phenotype.

Estudios de la región 5'UTR del gen FMR-1 en pacientes con falla ovárica prematura / Studies of the 5' - UTRTR region in the FMR-1 gene in patients withe Premature Ovarian Failure

La falla ovárica prematura (FOP) es un síndrome de patogénesis multicausal que afecta aproximadamente al 1% de las mujeres en edad reproductiva. Numerosos estudios asocian el estado de premutación (amplificación del número de tripletes CGG entre 50/55 y 200 repeticiones) en el gen FMR-1 y FOP. Alrededor de un 4% de las pacientes FOP presentan alelos con premutación. La amplificación del número de tripletes por encima de 200 repeticiones causa el Síndrome de Fragilidad del X (SFX). El objetivo del presente trabajo fue estudiar la región 5´ no codificante del gen en un grupo de pacientes FOP de Argentina. La región de interés se amplificó por PCR a partir de muestras de ADN de 100 pacientes FOP y 145 mujeres controles. Los alelos de las pacientes y controles fueron agrupados en 7 categorías de acuerdo al número de tripletes obtenidos. Se observó que el número de repeticiones más frecuente se encuentra en el rango de 26 a 30 tripletes, tanto en pacientes como en controles. En el grupo de pacientes FOP, 5/197 (2.6%) alelos no relacionados estudiados presentaron un número de tripletes CGG mayor a 50, mientras que sólo 1 de 290 (0.34%) para el grupo control. Todas las pacientes FOP con valores de tripletes CGG mayor a 50 presentaron amenorrea secundaria. Estos resultados están en concordancia con lo comunicado para otras poblaciones acerca de la existencia de una asociación entre la premutación del gen FMR-1 y el desarrollo de FOP. Asimismo, los resultados obtenidos refuerzan la importancia de la genotipificación del gen FMR-1 en las pacientes FOP, a los efectos de estimar el riesgo de su descendencia para el SFX.

Premature ovarian failure (POF) is a syndrome of multicausal pathogenesis that affects 1% of women before the age of 40. Several studies associate the premutation state (CGG repeats increased in number between 50/55 and 200) in the FMR-1 gene and POF. About 4% of POF women have alleles in the FMR-1 gene in the permutation range. An increase above 200 in the number of triplets in this gene causes the Fragile X Syndrome (FXS). The purpose of the present study was to analyze the 5´untranslated region of the FMR-1 gene in a group of patients from Argentina. The region of interest was amplified by PCR from DNA samples of 100 POF patients and 145 control women. Alleles from controls and patients were grouped in 7 categories according to the number of triplets obtained. We observed that the most frequent number of repeats ranged from 26 to 30 triplets, in both patient and control groups. In the POF group, 5 out of 197 (2.6%) not related alleles presented a number of CGG triplets higher than 50, while only 1 out of 290 (0.34%) was present in controls. All POF patients with a number of CGG repeats higher than 50 presented secondary amenorrhea. These results are in accordance with previous reports from other populations showing an association between the premutation state in the FMR-1 gene and POF development. In addition, these results reinforce the importance of genotyping POF patients to estimate the risk of their offspring for Fragile X Syndrome.

Validity of the calculation of non-sex hormone-binding globulin-bound estradiol from total testosterone, total estradiol and sex hormone-binding globulin concentrations in human serum.

Recent evidences indicate that biologically available serum testosterone (T) and estradiol (E2) include not only the free fractions but also most of the albumin-bound fractions. These two serum T or E2 fractions constitute most of non-sex hormone-binding globulin (SHBG)-bound T or E2, respectively. It has been reported that the estimation of serum non-SHBG-bound T gives identical results when it is assayed experimentally or when it is calculated by a formula derived from the law of mass action assuming two binding systems (T-SHBG and T-albumin). In the present work, we have compared the results of the experimental measurement of non-SHBG-bound E2 with the calculated value derived by an equation based on the law of mass action considering four binding systems (E2-SHBG, T-SHBG, E2-albumin, T-albumin). It was found that the two estimations of non-SHBG-bound E2 correlated closely in normal men (r = 0.80), normal women (r = 0.90) and hirsute women (r = 0.98). When compared with a more complex calculation which includes 21 steroids and 3 binding proteins results also agreed closely. Values for the different T and E2 fractions in these groups of subjects are given. These calculations could be used, not only for clinical research, but also in clinical practice as an useful tool for evaluation of the sex hormone status of patients.

Plasma concentration of oestradiol-17beta in premature thelarche and in different types of sexual precocity.

Plasma Oe2 concentration was measured by radioimmunoassay in patients with premature thelarche, with precocious puberty and in 29 normal controls. The mean plasma Oe2 was 1.5 pg/ml (0-7.2) in normal prepubertal girls, 23.8 +/- 17.8 (SD) in pubertal girls, 50.2 (+/- 19.4) in the follicular phase, and 94.2 (+/- 19.5) in the luteal phase of normal adult females. Ten girls with premature thelarche had a mean of 7.7 +/- 6.6 pg/ml. Three of them showed higher values than the other 7, suggesting that in these cases, elevated levels of plasma Oe2 might have played a role in the development of breast tissue. Ten untreated girls with idiopathic precocious sexual development had a mean of 51.6 +/- 42.9 pg/ml while 6 patients treated with 150 mg per week of medroxyprogesterone acetate had a mean of 11.4 +/- 2.5 pg/ml. Two patients with Down's syndrome, hypothyroidism and sexual precocity had plasma Oe2 of 144 and 31.5 which fell to 24.7 and 8 pg/ml, respectively, after thyroid replacement. One girl with a granulosa cell tumour had a basal value of 304 pg/ml and a concentration of 27 pg/ml after surgery.

Clinical assessment and serum hormonal profile in prepubertal hypertrichosis.

Twenty-two prepubertal girls with hypertrichosis were studied and compared to 10 prepubertal normal girls. Hypertrichosis was assessed according to a score that considers the amount and the distribution of vellus hair in androgen- and non-androgen-sensitive areas. Serum androgen profile and free androgen index (FAI) were determined in both groups. The hypertrichosis score was higher in patients than in the normal girls. Testosterone levels and FAI were increased in patients when compared to control; 3alpha-androstanediol glucuronide levels above 2 SD from the control mean were found in 10 girls and all hormonal parameters falling in the normal range were found in 4 girls. The new score designed to assess the degree of hypertrichosis was useful to differentiate between normal and pathological hair growth. Although most of the girls with prepubertal hypertrichosis showed an increased androgen bio-availability, a slight increase in peripheral 5alpha-reductase activity and a completely normal androgen profile was also associated with a pathological hair growth.

Gonadotropin secretion in prepubertal normal and agonadal children evaluated by ultrasensitive time-resolved immunofluorometric assays.

To analyze a possible gonadal effect on the control of gonadotropin secretion during the prepubertal period, we have measured the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) serum concentrations in children with primary gonadal failure (PGF). We measured them using an ultrasensitive immunofluorometric assay (IFMA) in a single daytime serum sample and compared the results with those obtained with a radioimmunoassay (RIA) technique. The patients were 22 children with PGF (13 girls and 9 boys) aged 0.56-15.4 years and 58 normal children (28 girls and 30 boys) aged 0.08-16 years. In the normal group there were significant changes in serum LH and FSH concentrations in relation to sex and pubertal development. These changes were more evident especially in LH concentrations when using IFMA. We observed that during the prepubertal period the normal LH levels (mean +/- SD) were detectable with this method at concentrations well below the limit RIA could detect (girls 0.026 +/- 0.012 IU/l, and boys 0.025 +/- 0.01 IU/l), while at the onset of puberty these LH levels rose significantly in both sexes (girls 1.0 +/- 0.79 IU/l, boys 1.7 +/- 0.7 IU/l; p < 0.01 vs. prepubertal group), reaching similar values to those observed in FSH concentrations (prepubertal girls 1.9 +/- 0.89 IU/l, boys 0.73 +/- 0.41 IU/l; early pubertal girls 3.1 +/- 0.9 IU/l, boys 2.6 +/- 1.3 IU/l). At prepubertal age, most PGF patients showed normal gonadotropin serum levels (particularly LH) when measured by RIA. However, these same samples-when measured by IFMA-showed LH and FSH levels clearly higher than normal in almost all-10 of 12-patients (PGF girls, n = 8, LH 1.1 +/- 1.0 IU/l, FSH 34 +/- 30 IU/l; PGF boys, n = 4, LH 0.13 +/- 0.12 IU/l, FSH 6.5 +/- 5.7 IU/l). We conclude that, during the so-called 'juvenile pause' when the gonadotropin concentrations could be reliably measured, supranormal gonadotropin levels could be observed during a single daytime serum sample in patients with PGF. These findings suggest that during this period of life the gonads contribute to the negative feedback regulation of gonadotropin levels.