bluuebunny/crossref_metadata_2025 huggingface dataset:
Adenosine-Regulated Cell Proliferation in Pituitary Folliculostellate and Endocrine Cells: Differential Roles for the A1 and A2B Adenosine Receptors
Authors: Rees D. A. , Lewis M. D. , Lewis B. M. , Smith P. J. , Scanlon M. F. , Ham J.
Published: January 2014

A1 and A2 adenosine receptors have been identified in the pituitary gland, but the cell type(s) on which they are located and their effects on pituitary cell growth are not known. Therefore, we analyzed the expression of A1 and A2 receptors in primary rat anterior pituitary cells, two pituitary folliculostellate (TtT/GF and Tpit/F1) and two pituitary endocrine (GH3 and AtT20) cell lines, and compared their effects on cell proliferation. In anterior pituitary and folliculostellate cells, adenosine and adenosine receptor agonists (5′-N-ethylcarboxamidoadenosine, a universal agonist, and CGS 21680, an A2A receptor agonist) stimulated cAMP levels with a rank order of potency that indicates the presence of functional A2B receptors. This stimulation, however, was not observed in either GH3 or AtT20 cells, where adenosine and the A1 receptor agonist 2-chloro-N6-cyclopentyladenosine inhibited VIP/forskolin-stimulated cAMP production. Expression of A2B and A1 receptors in the folliculostellate cells and that of the A1 receptor in the endocrine cells were confirmed by RT-PCR, immunocytochemistry, and ligand binding. Adenosine and 5′-N-ethylcarboxamidoadenosine dose-dependently (10 nm to 10 μm) stimulated growth in the folliculostellate, but not in the endocrine, cells, whereas in the latter, 100 μm adenosine and 2-chloro-N6-cyclopentyladenosine inhibited cell proliferation by slowing cell cycle progression. These data highlight the differential expression of A1 and A2B adenosine receptors in pituitary cells and provide evidence for opposing effects of adenosine on pituitary folliculostellate and endocrine cell growth.
Estradiol-Sensitive Afferents Modulate Long-Term Episodic Firing Patterns of GnRH Neurons
Authors: Nunemaker Craig S. , DeFazio R. Anthony , Moenter Suzanne M.
Published: January 2014

GnRH neurons comprise the final common pathway of an estrogen-sensitive pattern generator controlling fertility. To determine estradiol effects on GnRH neuron firing patterns, adult transgenic mice were ovariectomized (OVX), and half were treated with estradiol (OVX+E). One week later targeted single-unit extracellular recordings were made from GnRH neurons identified by green fluorescent protein expression. Estradiol markedly affected GnRH neuron firing patterns, increasing the percentage and duration of time these cells were quiescent (≤1 action current/min). Estradiol increased the interval between episodes of increased firing rate determined by Cluster analysis of recordings more than 45 min (OVX+E 38.8 ± 7.2 min, OVX 16.7 ± 2.1 min, n = 6 each). Possible mechanisms of estradiol modulation were examined by simultaneously blocking ionotropic secretion of γ-aminobutyric acid and glutamatergic receptors. This treatment had no effect on cells from OVX mice (n = 10), indicating episodic firing of GnRH neurons is not driven by activation of these receptors. Receptor blockade eliminated estradiol effects on GnRH neurons in the midventral preoptic area (n = 7) but not elsewhere (n = 7). Individual GnRH neurons thus display episodic firing patterns at intervals previously reported for secretory pulses. Estradiol modulates episode frequency to exert feedback control; in a substantial subset of GnRH neurons, estradiol feedback is enforced via GABAergic and/or glutamatergic afferents.
Increased Hepatic Peroxisome Proliferator-Activated Receptor-γ Coactivator-1 Gene Expression in a Rat Model of Intrauterine Growth Retardation and Subsequent Insulin Resistance
Authors: Lane Robert H. , MacLennan Nicole K. , Hsu Jennifer L. , Janke Sara M. , Pham Tho D.
Published: January 2014

Uteroplacental insufficiency and subsequent intrauterine growth retardation (IUGR) increase the risk of type 2 diabetes in humans and rats. Unsuppressed endogenous hepatic glucose production is a common component of the insulin resistance associated with type 2 diabetes. Peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1) mediates hepatic glucose production by controlling mRNA levels of glucose-6-phosphatase (G-6-Pase), phosphoenolpyruvate carboxykinase (PEPCK), and fructose-1,6-bisphosphatase (FBPase). We therefore hypothesized that gene expression of PGC-1 would be increased in juvenile IUGR rat livers, and this increase would directly correlate with hepatic mRNA levels of PEPCK, G-6-Pase, and FBPase, but not glucokinase. We found that IUGR hepatic PGC-1 protein levels were increased to 230 ± 32% and 310 ± 47% of control values at d 0 and d 21 of life, respectively. Similarly, IUGR hepatic PGC-1 mRNA levels were significantly elevated at both ages. Concurrent with the increased PGC-1 gene expression, IUGR hepatic mRNA levels of G-6-Pase, PEPCK, and FBPase were also significantly increased, whereas glucokinase mRNA levels were significantly decreased. These data suggest that increased PGC-1 expression and subsequent hepatic glucose production contribute to the insulin resistance observed in the IUGR juvenile rat.
Administration of 5α-Androstane-3α,17β-Diol to Female Tammar Wallaby Pouch Young Causes Development of a Mature Prostate and Male Urethra
Authors: Leihy Michael W. , Shaw Geoffrey , Renfree Marilyn B. , Wilson Jean D.
Published: January 2014

Secretion of 5α-androstane-3α,17β-diol (5α-adiol) by the testes of the tammar wallaby is responsible for initiation of prostatic development after d 20 in male pouch young. To ascertain the role of this hormone in the subsequent growth and differentiation of the prostate and in the development of the male phallus, 5α-adiol was administered to tammar female pouch young in two regimens. Administration of the hormone by mouth (8 μg/g body weight·wk) between d 70 and 150 of pouch life caused prostate development equivalent to that in d 150 males and promoted growth and differentiation of the penis, but not masculinization of the urethra. Treatment with a small dose of 5α-adiol enanthate (1 μg/g body weight·wk) from d 20–150 produced similar results. However, administration of larger doses of 5α-adiol enanthate (10 or 100 μg/g body weight·wk) from d 20–150 caused supraphysiological growth of the prostate, development of a male-type urethra, and penile growth. These results indicate that prostatic development and penile growth can be initiated over a wide time period, but that formation of a male urethra requires androgen action before d 70, when male penile differentiation begins. This further strengthens the hypothesis that 5α-adiol is the circulating androgen responsible in this species for virilization during development.
Leptin Is Inversely Related to Age at Menarche in Human Females*
Authors: Matkovic Velimir , Ilich Jasminka Z. , Skugor Mario , Badenhop Nancy E. , Goel Prem , Clairmont Albert , Klisovic Dino , Nahhas Ramzi W. , Landoll John D.
Published: January 2014

Over the last century there has been a trend toward an earlier onset of menarche attributed to better nutrition and body fatness. With the discovery of the obesity gene and its product, leptin, we reexamined this hypothesis from a new perspective. As delayed menarche and leanness are considered risk factors for osteoporosis, we also evaluated the relation between leptin and bone mass. Body composition and serum leptin levels were measured, and the timing of menarche was recorded in 343 pubertal females over 4 yr. Body composition was measured by dual x-ray absorptiometry, and leptin by a new RIA. All participants were premenarcheal at baseline (aged 8.3–13.1 yr). Leptin was strongly associated with body fat (r = 0.81; P < 0.0001) and change in body fat (r = 0.58; P < 0.0001). The rise in serum leptin concentration up to the level of 12.2 ng/mL (95% confidence interval, 7.2–16.7) was associated with the decline in age at menarche. An increase of 1 ng/mL in serum leptin lowered the age at menarche by 1 month. A serum leptin level of 12.2 ng/mL corresponded to a relative percent body fat of 29.7%, a body mass index of 22.3, and body fat of 16.0 kg. A gain in body fat of 1 kg lowered the timing of menarche by 13 days. Leptin was positively related to bone area (r = 0.307; P < 0.0001) and change in bone area (r = 0.274; P < 0.0001).

A critical blood leptin level is necessary to trigger reproductive ability in women, suggesting a threshold effect. Leptin is a mediator between adipose tissue and the gonads. Leptin may also mediate the effect of obesity on bone mass by influencing the periosteal envelope. This may have implications for the development of osteoporosis and osteoarthritis.
Mosaicism due to a Somatic Mutation of the Androgen Receptor Gene Determines Phenotype in Androgen Insensitivity Syndrome1
Authors: Holterhus Paul-Martin , Brüggenwirth Hennie T. , Hiort Olaf , Kleinkauf-Houcken Annette , Kruse Klaus , Sinnecker Gernot H. G. , Brinkmann Albert O.
Published: January 2014

Premature stop codons of the human androgen receptor (AR) gene are usually associated with a complete androgen insensitivity syndrome. We, however, identified an adult patient with a 46,XY karyotype carrying a premature stop codon in exon 1 of the AR gene presenting with signs of partial virilization: pubic hair Tanner stage 4 and clitoral enlargement. No other family members were affected. A point mutation at codon position 172 of the AR gene was detected that replaced the original TTA (Leu) with a premature stop codon TGA (opal). Careful examination of the sequencing gel, however, also identified a wild-type allele, indicating a mosaicism. In addition, elimination of the unique AflII recognition site induced by the mutation was incomplete, thus confirming the coexistence of mutant and wild-type AR alleles in the patient. Normal R1881 binding and a normal 110/112-kDa AR doublet in Western immunoblots consolidated the molecular genetic data by demonstrating the expression of the wild-type AR in the patient’s genital skin fibroblasts. Transfection analysis revealed that only relatively high plasmid concentrations carrying the mutated AR complementary DNA lead to expression of a shortened AR due to downstream reinitiation at methionine 189. Thus, reinitiation does not play a role in the presentation of the phenotype; rather, the partial virilization is caused by the expression of the wild-type AR due to a somatic mosaic. We conclude that somatic mosaicism of the AR gene can represent a substantial factor for the individual phenotype by shifting it to a higher degree of virilization than expected from the genotype of the mutant allele alone.
Cytokine Production by a New Undifferentiated Human Thyroid Carcinoma Cell Line, FB-11
Authors: Fiore Lisa , Pollina Luca E. , Fontanini Gabriella , Casalone Rosario , Berlingieri Maria T. , Giannini Riccardo , Pacini Furio , Miccoli Paolo , Toniolo Antonio , Fusco Alfredo , Basolo Fulvio
Published: January 2014

A human anaplastic thyroid cancer cell line FB-1, derived from a 68-yr-old woman who underwent surgery for anaplastic thyroid cancer, has been established. The spindlelike cells have been proliferating stably for more than 2 yr. Karyotype analysis shows many abnormalities and many marker chromosomes have been observed. Heterotransplant of FB-1 cells into severe combined immunodeficient mice has resulted in rapidly growing tumors classified as anaplastic carcinomas, although 50% have shown areas with a trabecular pattern. FB-1 cells failed to express messenger RNA for thyroglobulin; TSH-receptor; thyroperoxidase, and placental angiogenic growth factor. Conversely, PAX8 and thyroid transcription factor 1, whose expression is thyroid specific, was kept in an FB-1 cell line at a level comparable with that observed in normal thyroid tissue. In addition, the present cell line expressed high levels of messenger RNA for high-mobility group proteins (Y) and -C. The in vitro study revealed that FB-1 cells are able to produce high levels of interleukin (IL)-8 and medium amount of IL-6, whereas no release of IL-1-α, IL-1-β, and IL-4 was observed. No modulation of cell proliferation and DNA synthesis in FB-1 cells has been observed after the addition of exogenous IL-6.
Expression of Functional Leptin Receptors in the Human Ovary1
Authors: Karlsson Cecilia , Lindell Kajsa , Svensson Eva , Bergh Christina , Lind Peter , Billig Håkan , Carlsson Lena M. S. , Carlsson Björn
Published: January 2014

The size of body fat stores is known to influence fertility, indicating a link between adipose tissue and the reproductive system. Studies in mice have identified the adipocyte-derived hormone, leptin (Ob protein), as a possible mediator of this effect. The aim of this study was to investigate the possibility that leptin may have direct effects on the human ovary. To probe this hypothesis we first analyzed the expression of leptin receptors in the human ovary. Transcripts encoding both the long and short isoforms of the leptin receptor were present in human granulosa cells and thecal cells; however, the short isoforms were expressed at much higher levels. Immunoreactive leptin was present in follicular fluid at levels similar to those found in serum. ob gene expression, however, was undetectable in the ovary, as determined by reverse transcription-PCR, whereas it was easily detected in adipose tissue. To determine whether leptin could induce a biological response in ovarian cells, we examined the effect of leptin on estradiol production in cultured granulosa cells. Leptin (100 ng/mL) inhibited LH (0.1 ng/mL)-stimulated estradiol production. In contrast, leptin had no effect on estradiol production in the absence of LH.

In conclusion, this study has demonstrated that the leptin receptor is expressed in the human ovary, that leptin is present in follicular fluid, and that leptin can induce a biological response in ovarian cells. These results suggest that leptin may have a direct effect on the human ovary.
Human Estrogen Receptor β-Gene Structure, Chromosomal Localization, and Expression Pattern1
Authors: Enmark Eva , Pelto-Huikko Markku , Grandien Kaj , Lagercrantz Svetlana , Lagercrantz Jacob , Fried Gabriel , Nordenskjöld Magnus , Gustafsson Jan-Åke
Published: January 2014

The estrogen receptor (ER) is a ligand-activated transcription factor that mediates the effects of the steroid hormone 17β-estradiol, in both males and females. Since the isolation and cloning of ER, the consensus has been that only one such receptor exists.

The finding of a second subtype of ER (ERβ) has caused considerable excitement amongst endocrinologists. In this article, we present data regarding the genomic structure and chromosomal localization of the human ERβ gene, demonstrating that two independent ER genes do exist in the human. Furthermore, we present data regarding the tissue distribution of human ERβ, showing that this receptor is expressed in multiple tissues. For instance, ERβ is found in developing spermatids of the testis, a finding of potential relevance for the ongoing debate on the effects of environmental estrogens on sperm counts. In addition, we find ERβ in ovarian granulosa cells, indicating that estrogens also participate in the regulation of follicular growth in the human.
Biochemical Tests in the Diagnosis of Childhood Growth Hormone Deficiency*
Authors: Tillmann Vallo , Buckler John M. H. , Kibirige Mohammed S. , Price David A. , Shalet Stephen M. , Wales Jeremy K. H. , Addison Michael G. , Gill Mathew S. , Whatmore Andy J. , Clayton Peter E.
Published: January 2014

GH stimulation tests are widely used in the diagnosis of GH deficiency (GHD), although they are associated with a high false positive rate. We have examined, therefore, the performance of other tests of the GH axis[ urinary GH excretion, serum insulin-like growth factor I (IGF-I), and IGF-binding protein-3 (IGFBP-3) levels] compared with GH stimulation tests in identifying children defined clinically as GH deficient.

Group I comprised 60 children (mean age, 10.3 ± 4.8 yr) whose diagnosis of GHD was based on a medical history indicative of pituitary dysfunction (n = 43) or on the typical phenotypic features and appropriate auxological characteristics of isolated GHD (n = 17). Group II comprised 110 short children (mean age, 9.8 ± 4 yr) in whom GHD was not suspected, but needed exclusion.

The best sensitivity for a single GH test was 85% at a peak GH cut-off level of 10 ng/mL, whereas the best specificity was 92% at 5 ng/mL. The sensitivities of IGF-I, IGFBP-3, and urinary GH, using a cut-off of− 2 sd score were poor at 34%, 22%, and 25%, respectively, with specificities of 72%, 92%, and 76% respectively. Only 2 of 21 pubertal children in group I and none of the 27 subjects with radiation-induced GHD had an IGFBP-3 sd score less than −1.5. We devised a scoring system based on the positive predictive value of each test, incorporating data from the GH test and the IGF-I and IGFBP-3 levels. A specificity of 94% could be achieved with a score of 10 or more (maximum 17) (sensitivity 34%). The latter could not be improved above 81% with a score of 5 points or more (specificity, 69%).

A high score was, therefore, highly indicative of GHD, but was achieved by few patients. A normal IGFBP-3 level, however, did not exclude GHD, particularly in patients with radiation-induced GHD and those in puberty. A GH test with a peak level more than 10 ng/mL was the most useful single investigation to exclude a diagnosis of GHD.
15-Hydroxyprostaglandin Dehydrogenase: Implications in Preterm Labor with and without Ascending Infection1
Authors: van Meir Claudia A. , Matthews Stephen G. , Keirse Marc J. N. C. , Ramirez Mildred M. , Bocking Alan , Challis John R. G.
Published: January 2014

There is evidence that intrauterine infection, which stimulates PG synthesis may play a role in the pathogenesis of some preterm labor. Local tissue concentrations of PGs are controlled not only by the rate of synthesis, but also by catabolism, which is regulated by 15-hydroxyprostaglandin dehydrogenase (PGDH). We hypothesized that a decrease of PGDH activity could contribute to an increase in PG output at the time of preterm labor (PTL) especially in association with infection. We measured PGDH activity with a zero order kinetic enzymatic assay, PGDH messenger ribonucleic acid by in situ hybridization and PGDH distribution and localization with immunohistochemistry in human placenta and fetal membranes from women at term before (n = 10) or after (n = 16) labor compared to preterm labor at less than 36 weeks without (n = 16) and with (n = 11) chorioamnionitis. PGDH activity in chorion was significantly lower in PTL than at term and was further reduced when PTL was associated with inflammation. Immunoreactive PGDH and PGDH messenger ribonucleic acid localized predominantly to chorionic trophoblasts at term and were reduced in PTL women with or without infection. These effects were not observed in the placenta. Loss of PGDH with infection was associated with infiltration of chorion by polymorphonuclear leukocytes, resulting in a compromised structural integrity, although the amniotic epithelium was generally intact. We conclude that a reduction in PGDH in the human fetal membranes may occur in some cases of preterm labor and may contribute to an increase in net PG accumulation and drive to myometrial contractility.
The Longitudinal Course of Psychopathology in Cushing’s Syndrome after Correction of Hypercortisolism
Authors: Dorn Lorah D. , Burgess Ellen S. , Friedman Theodore C. , Dubbert Billinda , Gold Philip W. , Chrousos George P.
Published: January 2014

Endogenous Cushing’s syndrome (CS) is associated with significant psychopathology during the course of the disease. The purpose of this study was to evaluate the psychological and endocrine status of patients with CS after correction of their hypercortisolism. Thirty-three patients with active CS were examined before and at 3 months (28 patients), 6 months (25 patients), and 12 months (29 patients) after correction of hypercortisolism. Before cure, 66.7% of the patients had significant psychopathology, with the predominant diagnosis of atypical depressive disorder (AD) in 51.5% and/or major affective disorder in 12%. After cure, overall psychopathology decreased significantly to 53.6% at 3 months, 36% at 6 months, and 24.1% at 12 months, when there was a parallel recovery of the hypothalamic-pituitary-adrenal axis assessed by serial morning ACTH stimulation tests. There was an inverse correlation between psychological recovery and baseline morning cortisol, but no correlation with ACTH-stimulated cortisol values at 60 min. AD continued to be the prevailing diagnosis after correction of hypercortisolism, whereas the frequency of suicidal ideation and panic increased. The presence of AD before and after correction of hypercortisolism might be due to glucocorticoid-induced suppression of hypothalamic CRH secretion. The slight increase in the incidence of panic after correction of hypercortisolism might be due to a decreased glucocorticoid restraint at the central arousal/sympathetic catecholaminergic system. We conclude that CS is associated with AD symptomatology, which gradually improves with time after correction of hypercortisolism. Health care providers should be aware of changes in symptomatology, including suicidal ideation and panic attacks, that occur in a subgroup of patients.
II. Adrenal Cortex and Steroid 21-Hydroxylase Autoantibodies in Children with Organ-Specific Autoimmune Diseases: Markers of High Progression to Clinical Addison’s Disease
Authors: Betterle Corrado , Volpato Marina , Rees Smith Bernard , Furmaniak Jadwiga , Chen Shu , Zanchetta Renato , Greggio Nella A. , Pedini Beniamino , Boscaro Marco , Presotto Fabio
Published: January 2014

Adrenal cortex autoantibodies (ACA) were measured by immunofluorescence in 808 children with organ-specific autoimmune diseases without adrenal insufficiency. ACA were found in 14 children (1.7%), mostly in hypoparathyroidism (48%). Ten ACA-positive and 12 ACA-negative children were followed up for a maximum of 10 yr by evaluation of adrenocortical function (ACTH test) and autoantibody status. In all patients steroid-producing cell autoantibodies were assessed by immunofluorescence and autoantibodies to steroid 21-hydroxylase, 17α-hydroxylase, and cytochrome P450 side-chain cleavage enzyme by immunoprecipitation assay. All 10 ACA-positive patients were positive for 21-hydroxylase autoantibodies. Six were positive for steroid-producing cell autoantibodies and 5 also for autoantibodies to 17α-hydroxylase and/or P450 side-chain cleavage enzyme. Overt Addison’s disease developed in 9 (90%) ACA/21-OH-antibody-positive children after 3–121 months, and 1 remaining child had subclinical hypoadrenalism. By contrast, all ACA/21-OH antibody-negative children maintained normal adrenal function. Adrenal failure was not related to ACA titres, sex, adrenal function, type of preexisting autoimmune disorder, or human leucocyte antigens D-related status. In conclusion, in children with autoimmune endocrine diseases, ACA/21-hydroxylase autoantibodies are important predictive markers for the development of Addison’s disease.
Adjunctive Growth Hormone during Ovarian Hyperstimulation Increases Levels of Insulin-Like Growth Factor Binding Proteins in Follicular Fluid: A Randomized, Placebo-Controlled, Cross-Over Study*
Authors: Rabinovici Jaron , Cataldo Nicholas A. , Dandekar Pramila , Rosenthal Stephen M. , Gargosky Sharron E. , Gesundheit Neil , Martin Mary C.
Published: January 2014

GH increases circulating insulin-like growth factor I (IGF-I), which can promote the growth and differentiated function of ovarian granulosa and theca cells. Reported studies of GH as an adjunct to menotropin stimulation in women, largely those with ovarian dysfunction, have not consistently shown a benefit of GH, despite increases in serum and follicular fluid IGF-I. We hypothesized that changes in intrafollicular IGF-binding proteins (IGFBPs), which can antagonize IGF actions on granulosa cells, may underlie the inconsistent effects of GH. In the present study of GH, administered in double-blind, placebo-controlled, cross-over fashion to regularly cycling women undergoing in vitro fertilization, we found that follicular fluid levels of IGFBP-1, -3, and -4 and serum levels of IGFBP-3, as well as follicular fluid and serum IGF-I, were significantly increased in the GH-treated cycles, when compared with the placebo cycle of the same patient. We suggest that the net increase in intrafollicular IGFBPs in GH cycles may mitigate the potential beneficial effect of increased IGF-I.
Determination of Testosterone Production Rates in Men and Women Using Stable Isotope/Dilution and Mass Spectrometry*
Authors: Vierhapper H. , Nowotny P. , Waldhäusl W.
Published: January 2014

Production rates of testosterone were determined in healthy men and women during the follicular phase of their menstrual cycle using the stable isotope dilution technique and analysis by gas chromatography/mass spectrometry. In an initial series of experiments, 0.07 mg/h (men) or 0.01 mg/h (women) 1,2-d-testosterone was infused for 36 h. After an equilibration period of 12 h, blood samples were obtained at 20-min intervals throughout 24 h. In men, no diurnal rhythmicity of testosterone production was observed, whereas in women, testosterone production rates were largest from 0400–1200 h. In a second series of experiments, the infused dose of 1,2-d-testosterone was reduced to 0.015 mg/h (men) and 0.0001 mg/h (women), respectively. Blood samples were obtained at 20-min intervals during the last 12 h (0800–2000 h) of the observation period. In accordance with results obtained by others using radioactive tracers, estimated production rates were 147 ± 31μ g/h (3.7 ± 2.2 mg/day in men) and 1.8 ± 0.6 μg/h (0.4 ± 0.1 mg/day in women). To reduce both the duration of the experiment and the number of samples to be processed, we subsequently demonstrated that similar production rates may be obtained when the equilibration period before blood sampling is reduced to 6 h and the period of blood sampling is reduced to 4 h. This protocol is suitable for clinical use in a routine setting to obtain analytically correct estimates of testosterone production in vivo.
Aromatase Deficiency in a Female Who Is Compound Heterozygote for Two New Point Mutations in the P450arom Gene: Impact of Estrogens on Hypergonadotropic Hypogonadism, Multicystic Ovaries, and Bone Densitometry in Childhood1
Authors: Mullis Primus E. , Yoshimura Noriko , Kuhlmann Beatrice , Lippuner Kurt , Jaeger Philippe , Harada Hobuhiro
Published: January 2014

We report on a female who is compound heterozygote for two new point mutations in the CYP19 gene. The allele inherited from her mother presented a base pair deletion (C) occurring at P408 (CCC, exon 9), causing a frameshift that results in a nonsense codon 111 bp (37 aa) further down in the CYP19 gene. The allele inherited from her father showed a point mutation from G->A at the splicing point (canonical GT to mutational AT) between exon and intron 3. This mutation ignores the splice site and a stop codon 3 bp downstream occurs.

Aromatase deficiency was already suspected because of the marked virilization occurring prepartum in the mother, and the diagnosis was confirmed shortly after birth. Extremely low levels of serum estrogens were found in contrast to high levels of androgens. Ultrasonographic follow-up studies revealed persistently enlarged ovaries (19.5–22 mL) during early childhood (2 to 4 yr) which contained numerous large cysts up to 4.8 × 3.7 cm and normal-appearing large tertiary follicles already at the age of 2 yr. In addition, both basal and GnRH-induced FSH levels remained consistently strikingly elevated. Low-dose estradiol (E2) (0.4 mg/day) given for 50 days at the age of 36/12 yr resulted in normalization of serum gonadotropin levels, regression of ovarian size, and increase of whole body and lumbar spine (L1-L4) bone mineral density. The FSH concentration and ovarian size returned to pretreatment levels shortly (150 days) after cessation of E2 therapy. Therefore, we recommend that affected females be treated with low-dose E2 in amounts sufficient to result in physiological prepubertal E2 concentrations using an ultrasensitive estrogen assay. However, E2 replacement needs to be adjusted throughout childhood and puberty to ensure normal skeletal maturation and adequate adolescent growth spurt, normal accretion of bone mineral density, and, at the appropriate age, female secondary sex maturation.
Neonatal Hypothyroxinemia: Effects of Iodine Intake and Premature Birth1
Authors: Ares Susana , Escobar-Morreale Héctor F. , Quero José , Durán Socorro , Presas María Jesus , Herruzo Rafael , Morreale de Escobar Gabriella
Published: January 2014

We have investigated the effects of iodine (I) intake on urinary I excretion in preterm (PT) babies up to 2 months after birth and its effect on serum T4, free T4 (FT4), T3, TSH, and thyroglobulin (Tg) levels compared to those in term (T) newborns.

Very premature and very sick infants were in negative I balance for the first weeks after birth. Later, these same infants, as well as the other PT and T newborns, were in positive balance; 75–80% of the ingested I was not accounted for in the urine. The urinary I levels of PT and T neonates cannot be equated to their I intakes.

T4, FT4, and T3 levels in PT and T neonates increased with postmenstrual age, whereas Tg decreased and TSH did not change. Serum FT4, T3, Tg, and TSH levels in PT neonates were affected negatively, independently from age, by a low I intake. PT birth also affected T4, FT4, and Tg negatively, independently from I intake and postmenstrual age, for at least 6–8 weeks after birth.

Care should be taken to avoid I deficiency in PT neonates. However, even when I intake is adequate, PT newborns are hypothyroxinemic compared to T babies during an important period of brain development. This suggests the possible convenience of interventions that might mimic the intrauterine hormone environment and accelerate maturation.
Increase in Urinary Cortisol Excretion and Memory Declines: MacArthur Studies of Successful Aging1
Authors: Seeman Teresa E. , McEwen Bruce S. , Singer Burton H. , Albert Marilyn S. , Rowe John W.
Published: January 2014

Cortisol production is increased during stress, and the actions of cortisol on receptors in the brain and other body organs are involved in allostasis, the process of adaptation to stress, as well as in allostatic load, the wear and tear associated with excessive exposure to cortisol. Using data from a community-based longitudinal study of older men and women, aged 70–79 yr, we tested the hypothesis that exposure to increasing levels of cortisol is associated with declines in memory performance. Associations between 12-h urinary free cortisol excretion and performance on tests of memory (delayed verbal recall and spatial recognition), abstraction, and spatial ability were examined. Among the women, greater cortisol excretion was associated with poorer baseline memory performance, independent of socio-demographic, health status, health behavior, and psychosocial characteristics. Moreover, women who exhibited increases in cortisol excretion over a 2.5-yr follow-up period were more likely to show declines in memory performance. By contrast, women who experienced declines in cortisol exhibited improvements in memory performance. No significant associations were found among the men. The results for the women suggest that decrements in memory performance associated with increases in cortisol may not represent irreversible effects, as declines in cortisol were associated with improvements in memory.
The Death of Osteocytes via Apoptosis Accompanies Estrogen Withdrawal in Human Bone*
Authors: Tomkinson A. , Reeve J. , Shaw R. W. , Noble B. S.
Published: January 2014

Estrogen withdrawal in women leads initially to rapid bone loss caused by increased numbers or activity of osteoclasts. We previously have noted apoptosis of lacunar osteocytes associated with conditions of high bone turnover. Therefore, in this study, we investigated whether the increased bone loss associated with GnRH analogue (GnRH-a)-induced estrogen withdrawal affects osteocyte viability in situ in a way that would be directly contrary to the effect of estrogens on osteoclast viability.

Transiliac biopsies were obtained from six premenopausal women, between 30–45 yr old, diagnosed as having endometriosis. Biopsies were taken before and after 24 weeks of GnRH-a therapy. Biopsies were snap-frozen and cryostat sectioned. Osteocyte viability, determined by the presence of lactate dehydrogenase (LDH) activity, was reduced in all but one subject after treatment. Furthermore, in every subject, the proportion of osteocytes showing evidence of DNA fragmentation typical of apoptosis increased, as demonstrated using in situ DNA nick translation (P = 0.008). Gel electrophoresis of extracted DNA and morphological studies of chromatin condensation and nuclear fragmentation confirmed that changes typical of apoptosis were affecting the osteocytes.

It was concluded that GnRH-a therapy caused a higher prevalence of dead osteocytes in iliac bone, probably caused by the increase in the observed proportion of osteocytes showing apoptotic changes. The capacity of bone to repair microdamage and to modulate the effects of mechanical strain is currently believed to be dependent on osteocyte viability. Our findings have therefore revealed a possible mechanism whereby estrogen deficiency could lead to increased bone fragility with or without an accompanying net bone loss.
Effects of Short-Term Insulin-Like Growth Factor-I (IGF-I) or Growth Hormone (GH) Treatment on Bone Metabolism and on Production of 1,25-Dihydroxycholecalciferol in GH-Deficient Adults1
Authors: Bianda Tarcisio , Glatz Yvonne , Bouillon Roger , Froesch Ernst Rudolf , Schmid Christoph
Published: January 2014

Administration of insulin-like growth factor-I (IGF-I) or growth hormone (GH) is known to stimulate bone turnover and kidney function. To investigate the effects of IGF-I and GH on markers of bone turnover, eight adult GH-deficient patients (48 ± 14 yr of age) were treated with IGF-I (5 μg/kg/h in a continuous sc infusion) and GH (0.03 IU/kg/daily sc injection at 2000 h) in a randomized cross-over study. We monitored baseline values for three consecutive days before initiating the five-day treatment period, as well as the wash-out period of ten weeks. Serum osteocalcin, carboxyterminal and aminoterminal propeptide of type I procollagen (PICP and PINP, respectively) increased significantly within 2–3 days of both treatments (P < 0.02) and returned to baseline levels within one week after the treatment end. The changes in resorption markers were less marked as compared with formation markers. Total 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) rose significantly, whereas PTH and calcium levels remained unchanged during either treatment. Conclusions: Because the rapid increase in markers of bone formation was not preceded by an increase in resorption markers, IGF-I is likely to stimulate bone formation by a direct effect on osteoblasts. Moreover, because PTH, calcium, and phosphate remained unchanged, IGF-I appears to stimulate renal 1α-hydroxylase activity in vivo.
Analysis of Localization of Mutated Tissue-Nonspecific Alkaline Phosphatase Proteins Associated with Neonatal Hypophosphatasia Using Green Fluorescent Protein Chimeras1
Authors: Cai Guiming , Michigami Toshimi , Yamamoto Takehisa , Yasui Natsuo , Satomura Kenichi , Yamagata Masayo , Shima Masaaki , Nakajima Shigeo , Mushiake Sotaro , Okada Shintaro , Ozono Keiichi
Published: January 2014

Hypophosphatasia is associated with a defect of the tissue-nonspecific alkaline phosphatase (TNSALP) gene. The onset and clinical severity are usually correlated in hypophosphatasia; patients with perinatal hypophosphatasia die approximately at the time of birth. In contrast, we describe a male neonatal patient with hypophosphatasia who had no respiratory problems and survived. He was compound heterozygous for the conversion of Phe to Leu at codon 310 (F310L) and the deletion of a nucleotide T at 1735 (delT1735), causing the frame shift with the result of the addition of 80 amino acids at the C-terminal of the protein. Because the C-terminal portion of TNSALP is known to be important for TNSALP to bind to the plasma membrane, the localization of wild-type and mutated TNSALP proteins was analyzed using green fluorescent protein chimeras. The expression vectors containing the complementary DNA of fusion proteins consisting of signal peptide, green fluorescent protein, and wild-type or mutated TNSALP, caused by delT1735 or F310L mutation, were introduced transiently or stably in Saos-2 cells. The delT1735 mutant failed to localize at the cell surface membrane, whereas the wild-type and the F310L mutants were located in the plasma membrane and cytoplasm. The assay for enzymatic activity of TNSALP revealed that the delT1735 mutant lost the activity and that the F310L mutant exhibited an enzymatic activity level that was 72% of the normal level. The F310L mutation was also detected in another neonatal patient with relatively mild (nonlethal) hypophosphatasia (reported in J Clin Endocrinol Metab, 81:4458–4461, 1996), suggesting that residual ALP activity of the F310L mutant contributes to the less severe phenotype. The patient is unique, with respect to a discrepancy between onset and clinical severity in hypophosphatasia.
Association Between Insulin-Like Growth Factor I and Bone Mineral Density in Older Women and Men: The Framingham Heart Study1
Authors: Langlois Jean A. , Rosen Clifford J. , Visser Marjolein , Hannan Marian T. , Harris Tamara , Wilson Peter W. F. , Kiel Douglas P.
Published: January 2014

Few studies of the GH axis and bone have focused specifically on elderly people. The objective of this study was to determine the association between insulin-like growth factor I (IGF-I) and bone mineral density (BMD) in 425 women and 257 men aged 72–94 who participated in the Framingham Osteoporosis Study component of the Framingham Heart Study in 1992–1993. Serum IGF-I level was determined by RIA. BMD at three femoral sites and the lumbar spine was determined by dual x-ray absorptiometry, and at the radius by single-photon absorptiometry. IGF-I level was positively associated with BMD at all five sites (Ward’s area, femoral neck, trochanter, radius, and lumbar spine) in women after adjustment for weight loss and other factors (P ≤ 0.01) and protein intake in a subset of participants (0.006 < P < 0.07). A threshold effect of higher BMD was evident at each of the 3 femoral sites and the spine (P < 0.03) but not at the radius for women in the highest quintile of IGF-I (≥179 g/liter) vs. those in the lowest four quintiles. IGF-I was not significantly associated with BMD in men. These results indicate that higher IGF-I levels are associated with greater BMD in very old women, and suggest that future clinical trials employing GH may have a role in the development of treatments for older women with osteoporosis.
Gender Differences in Basal Protein Kinetics in Young Adults
Authors: Volpi Elena , Lucidi Paola , Bolli Geremia B. , Santeusanio Fausto , De Feo Pierpaolo
Published: January 2014

Gender affects energy expenditure and influences the relative utilization of carbohydrate and fat as fuels. However, little is known about the possible effects of gender on protein metabolism. Thus, we compared whole body and plasma (albumin and fibrinogen) protein kinetics in the basal postabsorptive state in young, untrained volunteers divided into two groups according to gender (women: n = 17; age, 24 ± 4 yr; men: n = 17; age, 25 ± 2 yr). The two groups were matched for body mass index. Protein kinetics were measured by means of l-[1-14C]leucine infusion. The leucine whole body rate of appearance, an index of proteolysis, and nonoxidative rate of disappearance, an index of protein synthesis, were similar in the two groups. However, the leucine oxidation rate was significantly lower in women compared to men (0.23 ± 0.07 vs. 0.31 ± 0.08μ mol/kg·min; P = 0.0062). Similar results were obtained when data were adjusted for estimated body composition. Albumin and fibrinogen fractional secretion rates were not different in the two groups. In conclusion, in the basal state leucine oxidation is lower in women than in men regardless of body composition. This could be one of the factors contributing to the lower metabolic rate in women.
The Insulin-Like Growth Factor Axis and Plasma Lipid Levels in the Elderly1
Authors: Ceda Gian Paolo , Dall’Aglio Elisabetta , Magnacavallo Andrea , Vargas Nicola , Fontana Vittorio , Maggio Marcello , Valenti Giorgio , Lee Phillip D. K. , Hintz Raymond L. , Hoffman Andrew R.
Published: January 2014

The activity of the hypothalamic-GH-insulin-like growth factor (IGF) network declines with age. It has recently been shown that increased cardiovascular mortality occurs in adults with GH deficiency. As hypercholesterolemia is common in GH-deficient adults, and because there is experimental evidence that GH may play a role in regulating plasma cholesterol, we decided to investigate the activity of the GH-IGF axis in an elderly population by measuring serum IGF-I, IGF-II, and IGF-binding protein-3 (IGFBP-3) levels and to study their relationship with blood lipid levels. One hundred and thirty-two elderly subjects, 52 men and 80 women, were studied (age range, 60–91 yr). Men had significantly lower levels of IGFBP-3, high density lipoprotein cholesterol (HDL-C) and apoprotein A1 (ApoA1) compared to the women, whereas IGF-I and IGF-II were only slightly lower. Using linear regression analysis, we observed an inverse relationship of age with IGF-I (r = −0.35; P < 0.001), IGF-II (r = 0.40; P < 0.001), IGFBP-3 (r = 0.52; P < 0.001), body mass index, and lipid levels. Univariate regression analysis showed a strong and positive correlation of both IGF-I and IGFBP-3 with HDL-C and ApoA1. Partial correlation analysis, after adjustment for age and body mass index, showed that IGFBP-3 and IGF-II were still significantly and positively related to HDL-C and ApoA1. Furthermore, a strong association was documented among IGF-I, IGF-II, and IGFBP-3. These data demonstrate that even in an elderly population, further aging is accompanied by a progressive decline in circulating IGF-I, IGF-II, and IGFBP-3, suggesting a continuing diminution of the GH-IGF axis throughout aging. Moreover, the strong correlation between HDL-C and an index of GH secretion, such as IGFBP-3, suggests that GH might play an important role in lipid metabolism in healthy elderly subjects.
The 64-Kilodalton Eye Muscle Protein Is the Flavoprotein Subunit of Mitochondrial Succinate Dehydrogenase: The Corresponding Serum Antibodies Are Good Markers of an Immune-Mediated Damage to the Eye Muscle in Patients with Graves’ Hyperthyroidism1
Authors: Kubota S. , Gunji K. , Ackrell B. A. C. , Cochran B. , Stolarski C. , Wengrowicz S. , Kennerdell J. S. , Hiromatsu Y. , Wall J.
Published: January 2014

Thyroid-associated ophthalmopathy (TAO) is a progressive eye disorder associated with thyroid autoimmunity, particularly Graves’ hyperthyroidism, which is generally considered to have an autoimmune etiology. Eye muscle membrane proteins reportedly of 55 and 64 kDa are the best markers of the ophthalmopathy. The main focus of our recent studies has been to purify the pertinent proteins from porcine eye muscle membranes and characterize them. The 64-kDa protein is now shown from a partial sequence and by Western blotting using specific antibody probes to be the flavoprotein (Fp) subunit of succinate dehydrogenase and to have a correct molecular mass of 67 kDa. The protein was purified and cleaved with cyanogen bromide, and the N-terminal region of an immunoreactive partial peptide was determined. The 20-amino acid porcine sequence so obtained matched one within the Fp subunits of human and bovine succinate dehydrogenases in 20 and 18 of these positions, respectively. Succinate dehydrogenase is both a citric acid cycle enzyme and a component (complex II) of the mitochondrial respiratory chain. It is thus essential for aerobic energy production and is highly conserved. The mature human and bovine Fp subunits are 92% homologous and have a molecular mass of ∼67 kDa, the same as our redetermined value for the 64-kDa marker protein. Sera from patients with TAO and from those with Graves’ hyperthyroidism without evident ophthalmopathy highlighted the 64-kDa marker protein in crude porcine eye muscle membranes and the Fp subunit of highly purified bovine succinate dehydrogenase at the identical position on Western blots. Anti-beef Fp antibodies were detected in sera from 67% of patients with active TAO of more than 1-yr duration, in 30% with stable TAO of more than 3-yr duration, and in 30% of patients with Graves’ hyperthyroidism without ophthalmopathy, but in only 7% of age- and sex-matched normal subjects. As succinate dehydrogenase is bound to the matrix (inside) surface of the mitochondrial inner membrane, it is unlikely to be accessible to circulating autoantibodies. We would postulate that eye muscle damage in ophthalmopathy is probably caused by cytotoxic antibodies or CD+ T lymphocytes targeting a cell membrane antigen, such as the thyroid and eye muscle shared protein G2s, and that presentation of succinate dehydrogenase is secondary. On the other hand, an autoantibody response to succinate dehydrogenase may be a good marker of immune-mediated damage to the eye muscle fiber and may support the idea that the extraocular muscles are targets of the autoimmune reactions of TAO.
Effects of the Circadian Variation in Serum Cortisol on Markers of Bone Turnover and Calcium Homeostasis in Normal Postmenopausal Women1
Authors: Heshmati Hassan M. , Riggs B. Lawrence , Burritt Mary F. , McAlister Carol A. , Wollan Peter C. , Khosla Sundeep
Published: January 2014

Bone turnover has a circadian pattern, with bone resorption and, to a lesser extent, bone formation increasing at night. Serum cortisol also has a circadian pattern and is a potential candidate for mediating the circadian changes in bone turnover. Thus, we measured bone formation and resorption markers before (study A) and after (study B) elimination of the morning peak of cortisol. We also assessed effects of the circadian cortisol pattern on serum calcium, PTH, and urinary calcium excretion. Ten normal postmenopausal women, aged 63–75 yr (mean, 69 yr), were studied. Metyrapone was administered to block endogenous cortisol synthesis and either a variable (study A) or a constant (study B) infusion of cortisol was given to reproduce and then abolish the morning cortisol peak. Blood was sampled every 2 h for serum cortisol, ionized calcium, PTH, and bone formation markers[ osteocalcin and carboxyl-terminal propeptide of type I collagen (PICP)], and timed 4-h urine samples were collected for measurement of calcium, phosphorus, sodium, potassium, and bone resorption markers (N-telopeptide of type I collagen and free deoxypyridinoline).

During study A, serum osteocalcin had a circadian pattern, with a peak at 0400 h and a nadir at 1400 h. During study B, however, the afternoon nadir of serum osteocalcin was eliminated (P < 0.001 and P < 0.005 for the difference in the patterns of peak and nadir, respectively, on the 2 study days). In contrast, the circadian patterns of serum PICP and urinary N-telopeptide of type I collagen and free deoxypyridinoline were virtually identical during the two studies. Urinary calcium excretion declined after the cortisol peak, without differences between the 2 study days in phosphorus or sodium excretion or in serum PTH. We conclude that the circadian variation in serum cortisol is responsible for the circadian pattern of serum osteocalcin, but not that of PICP or bone resorption markers. The physiological variation in serum cortisol may also reduce urinary calcium excretion.