bluuebunny/crossref_metadata_2025 huggingface dataset:
Parathyroid Responsivity in Postmenopausal Women with Osteoporosis During Treatment with Parathyroid Hormone1
Authors: Cosman Felicia , Nieves Jeri , Woelfert Lillian , Gordon Susan , Shen Victor , Lindsay Robert
Published: January 2014

Endocrine systems may be affected permanently by administration of supraphysiologic doses of hormone. This is a well known complication of glucocorticoid treatment where the pituitary/adrenal axis may never fully recover, especially when large doses of steroids are needed during significant physical stress. The goal of this investigation was to determine whether responsivity of the parathyroid gland was normal after use of (1–34)PTH daily as an investigational therapy for osteoporosis. Patients were all postmenopausal osteoporotic women treated with estrogen and enrolled in a 3-yr trial of (1–34)PTH by daily subcutaneous injection (400 IU/day) in addition to their estrogen therapy. A volunteer subgroup (n = 10) of this population was recruited for this investigation. All patients had an EDTA-provoked hypocalcemic challenge before beginning PTH treatment. The same patients had repeat EDTA-challenge tests at various times during the 3-yr PTH treatment trial. Three patients had 2 infusions while on PTH treatment (interim and at the end of 3 yr). Ionized calcium declined identically before and during PTH treatment in response to the EDTA stimulus. PTH(1–84) responses were identical before and during PTH therapy. Furthermore, there were no differences in 1,25(OH)2D elevation or in phosphorus reduction over the course of the EDTA infusion during daily PTH treatment. Osteocalcin levels were higher during PTH treatment, as expected, but responsivity to acute endogenous PTH elevations was the same after PTH treatment. We conclude that 1–34PTH therapy, at 400 IU/day for up to 3 yr, does not suppress parathyroid responsivity and should therefore (at least within this period of treatment) have no permanent adverse effect on the ability of the body to maintain calcium homeostasis. Additionally, there is no difference in target organ responsivity to acute endogenous elevations of PTH after exogenous PTH therapy.
Influence of Exogenous Atrial Natriuretic Peptide on the Pituitary-Adrenal Response to Corticotropin-Releasing Hormone and Vasopressin in Healthy Men
Authors: Bierwolf Claudia , Burgemeister Axel , Lüthke Karen , Born Jan , Fehm Horst L.
Published: January 2014

Atrial natriuretic peptide (ANP) has been considered a potential candidate participating in the inhibitory control of pituitary-adrenal secretory activity. Here, we investigated the influence of ANP, infused at two different doses and over infusion intervals of two different durations, on the release of ACTH and cortisol after stimulation with CRH and with combined administration of CRH and vasopressin (VP). In young healthy men, three experiments were conducted. In Exp I, ACTH/cortisol secretory responses to CRH (50 μg) were examined during and after a 45-min period of ANP infusion at a rate of 4.4 μg/min (starting 15 min before CRH injection). In Exp II, ACTH/cortisol secretory responses to CRH (50 μg) were examined during and after a 90-min infusion period of ANP administered at rates of 4.4 and 8.8μ g/min. In Exp III, ANP was infused at a rate of 4.4 μg/min over 90 min, but instead of CRH, a combined administration of CRH (50 μg) and VP (0.5 IU infused within 5 min) was employed to stimulate ACTH/cortisol release. ANP diminished pituitary-adrenal secretory responses within the first hour after stimulation with exogenous secretagogues. Thereafter, the effect of ANP turned in the opposite direction, with distinctly enhanced concentrations of ACTH and cortisol during the third hour after stimulation. The inhibitory effect of ANP during the first hour of the pituitary-adrenal response was more pronounced on concentrations of cortisol than ACTH and was also more pronounced after combined administration of CRH/VP than after stimulation with CRH alone. Increasing the dose of ANP enhanced the late stimulatory effect on ACTH/cortisol release, thereby terminating the early period of inhibited ACTH/cortisol release more abruptly. The late stimulatory effect was enhanced with prolonged infusion of ANP. In addition, it was associated with reduced hematocrit, increased urine volumes collected, increased heart rate, and enhanced plasma VP concentrations. Together, these changes suggest that the late stimulatory effect of ANP on ACTH/cortisol release reflects an effect secondary to its hypovolemic actions. This stimulatory effect originating from peripheral systemic actions of ANP after exogenous administration appears to override a more direct inhibitory action of the peptide on pituitary-adrenal secretory activity. Therefore, we would expect that with localized release into portal hypophyseal blood the inhibitory component of the action of ANP on pituitary-adrenal secretory activity prevails.
Effects of Human Growth Hormone, Insulin-Like Growth Factor I, and Diet and Exercise on Body Composition of Obese Postmenopausal Women1
Authors: Thompson J. L. , Butterfield G. E. , Gylfadottir U. K. , Yesavage J. , Marcus R. , Hintz R. L. , Pearman A. , Hoffman A. R.
Published: January 2014

To determine the effects of GH and insulin-like growth factor I (IGF-I) administration, diet, and exercise on weight loss, body composition, basal metabolic rate (BMR), muscle strength, and psychological status, 33 moderately obese postmenopausal women (67.1 ± 5.2 yr) participated in a 12-week randomized, double blind study. Participants were placed on a diet that provided 500 Cal/day less than that needed for weight maintenance, and they walked 3 days and strength trained 2 days each week. Subjects also self-injected GH (0.025 mg/kg BW·day), IGF-I (0.015 mg/kg BW·day), a combination of these doses of GH and IGF-I, or placebo (P). Twenty-eight women completed the study, as five subjects dropped out due to intolerable side-effects (e.g. edema). Weight loss occurred in all groups, with the largest decrease occurring in the GH plus IGF-I group (5.6 ± 1.4 kg). Fat mass significantly decreased in all groups, with the largest losses observed in GH and GH plus IGF-I groups (6.3 ± 1.8 and 8.4 ± 2.8 kg, respectively). Despite weight loss, BMR was maintained in all groups. Muscle strength increased with training for all groups, and depression and anxiety scores decreased in groups receiving IGF-I. These data show that obese postmenopausal women can lose weight and fat without compromising fat free mass, BMR, or gains in muscle strength, and that GH and IGF-I given together may enhance fat loss over either given alone.
Comparison between Insulin-Induced Hypoglycemia and Growth Hormone (GH)-Releasing Hormone + Arginine as Provocative Tests for the Diagnosis of GH Deficiency in Adults1
Authors: Aimaretti G. , Corneli G. , Razzore P. , Bellone S. , Baffoni C. , Arvat E. , Camanni F. , Ghigo E.
Published: January 2014

There is now wide consensus that, within an appropriate clinical context, GH deficiency (GHD) in adults must be shown biochemically by provocative testing of GH secretion and that appropriate cut-off limits have to be defined for each provocative test. Insulin-induced hypoglycemia (ITT) is indicated as the test of choice, and severe GHD, to be treated with recombinant human GH replacement, is defined by a GH peak response to ITT of less than 3 μg/L. GHRH + arginine (GHRH+ARG) is one of the most promising tests in alternative to ITT. In fact, it has been reported as a potent, reproducible, and age-independent test and that it is able to distinguish between GHD and normal adults. The aim of the present study was to compare the GH response to ITT and GHRH+ARG in a large group of hypopituitary adults (n = 40; 29 male and 11 female; age: 36.4 ± 2.1 yr). The third centile limit of the peak GH response to ITT has been reported as 5 μg/L, whereas in our lab, that to GHRH+ARG is 16.5 μg/L. In hypopituitary adults, the mean peak GH response to ITT (1.5 ± 0.2 μg/L, range: 0.1–8.5μ g/L) was lower (P < 0.001) than that to GHRH+ARG (3.0 ± 0.4 μg/L, range 0.1–12.0 μg/L), though there was positive correlation (r = 0.61, P < 0.001) between the GH responses to the 2 tests. The peak GH response to GHRH+ARG, but not that to ITT, was positively (though weakly) associated with insulin-like growth factor-I levels (r = 0.35, P < 0.03). Childhood and adult onset GHD patients, as well as patients with single and multiple pituitary insufficiencies, had similar peak GH responses to ITT or GHRH+ARG. Analyzing individual GH responses, 4/40 (10%) of the hypopituitary patients had GH peaks higher than 5 μg/L after ITT; moreover, 3 other patients (7%) had GH peaks, after ITT, higher than 3 μg/L. On the other hand, after GHRH+ARG, all patients had GH peaks lower than 16.5 μg/L, whereas 21/40 (52.5%) had GH peaks higher than 3 μg/L. Because 3 μg/L is the arbitrary cut-off for ITT, the third centile limit of which is 5μ g/L, we arbitrarily considered 9 μg/L as the cut-off point for GHRH+ARG. It is noteworthy that 37/40 (92.5%) patients had a GH peak,. after GHRH+ARG, below this limit. In conclusion, our present results confirm that the ITT test is a reliable provocative test for the diagnosis of adult GHD, whereas they show that the GHRH+ARG test is, at least, as sensitive as the ITT test (provided that appropriate cut-off limits are considered). Note that even the arbitrary cut-off point below which severe GHD is demonstrated has to be appropriate to the potency of the test.
Leptin Expression in Human Mammary Epithelial Cells and Breast Milk
Authors: Smith-Kirwin Susan M. , O’Connor Darlise M. , Johnston Jennifer , de Lancy Elizabeth , Hassink Sandra G. , Funanage Vicky L.
Published: January 2014

Leptin has recently been shown to be produced by the human placenta and potentially plays a role in fetal and neonatal growth. Many functions of the placenta are replaced by the mammary gland in terms of providing critical growth factors for the newborn. In this study, we show that leptin is produced by human mammary epithelial cells as revealed by RT/PCR analysis of total RNA from mammary gland and immunohistochemical staining of breast tissue, cultured mammary epithelial cells, and secretory epithelial cells present in human milk. We also verify that immunoreactive leptin is present in whole milk at 30- to 150-fold higher concentrations than skim milk. We propose that leptin is secreted by mammary epithelial cells in milk fat globules, which partition into the lipid portion of breast milk.
Beneficial Effect of Diazoxide in Obese Hyperinsulinemic Adults1
Authors: Alemzadeh Ramin , Langley Gina , Upchurch Lori , Smith Pam , Slonim Alfred E.
Published: January 2014

Hyperinsulinemia, insulin resistance, and increased adipose tissue are hallmarks of the obesity state in both humans and experimental animals. The role of hyperinsulinemia as a possible preceding event in the development of obesity has been proposed. We previously demonstrated that administration of diazoxide (DZ), an inhibitor of insulin secretion, to obese hyperinsulinemic Zucker rats resulted in less weight gain, enhanced insulin sensitivity, and improved glucose tolerance. Assuming that hyperinsulinemia plays a major role in the development of human obesity, then its reversal should have therapeutic potential. To test this hypothesis, we conducted a randomized placebo-controlled trial in 24 hyperinsulinemic adults [body mass index (BMI) > 30 kg/m2]. All subjects were placed on a low-calorie (1260 for females and 1570 for males) Optifast (Sandoz, Minneapolis, MN) diet. After an initial 1-week lead-in period, 12 subjects (mean ± se for age and BMI, 31 ± 1 and 40 ± 2, respectively) received DZ (2 mg/kg BW·day; maximum, 200 mg/day, divided into 3 doses) for 8 weeks; and 12 subjects (mean± se for age and BMI, 28 ± 1 and 43 ± 1, respectively) received placebo. Compared with the placebo group, DZ subjects had greater weight loss (9.5 ± 0.69% vs. 4.6 ± 0.61%, P < 0.001), greater decrease in body fat (P < 0.01), greater increase in fat-free mass to body fat ratio (P < 0.01), and greater attenuation of acute insulin response to glucose (P < 0.01). However, there was no significant difference in insulin sensitivity and glucose effectiveness, as determined by the insulin-modified iv glucose tolerance test (Bergman’s minimal model) and no significant difference in glycohemoglobin values. Conclusion: 8 weeks treatment with DZ had a significant antiobesity effect in hyperinsulinemic obese adults without inducing hyperglycemia.
Increased CD69 and Human Leukocyte Antigen-DR Expression on T Lymphocytes in Insulin-Dependent Diabetes Mellitus of Long Standing
Authors: Gessl Alois , Waldhäusl Werner
Published: January 2014

To better define prevailing activation of circulating T cell subsets in insulin-dependent diabetes mellitus (IDDM) of recent onset (DM; n= 31; median age ± sd,, 28 ± 6.9 yr) and of long standing (DML; n = 27; age, 33 ± 10.4 yr; median duration of disease, 105 months), CD4+ and CD8+ T cells were analyzed to determine their naive and memory subsets as well as their expression of human leukocyte antigen (HLA)-DR, interleukin-2 receptor α-chain (CD25), and CD69 by three-color flow cytometry. Twenty-six healthy subjects (HS; age, 32.0 ± 8.2 yr) served as controls.

No deviation was seen in either IDDM group compared to HS in CD25 expression on CD4+ or CD8+ cells or in their CD45RA+ or CD45RA− subsets. HLA-DR expression, however, was increased (P < 0.05) in total CD8+ cells and CD45RA+ cells, with CD45RA− CD8+ cells joining the prevailing pattern only in DML. Among CD4+ cells, increased expression of HLA-DR molecules was restricted to total and CD45RA− cells in DML. CD69 expression did not differ between IDDM and HS, but differed between DML (CD4+, CD8+, and CD45RA− CD4+) and DM only.

In conclusion, our data demonstrate that HLA-DR expression in IDDM is restricted to memory cells (CD45RA−) among CD4+ cells in DML and is more markedly confined to naive (CD45RA+) than to memory CD8+ cells, whereas the early activation antigen CD69 is more readily expressed in DML than in DM. The observed activation of circulating T cells suggests an ongoing immune process in IDDM both at clinical manifestation and after long duration.
A Family with Liddle’s Syndrome Caused by a New Missense Mutation in the β Subunit of the Epithelial Sodium Channel
Authors: Inoue Junnosuke , Iwaoka Taisuke , Tokunaga Hiroshi , Takamune Kazufumi , Naomi Shojiro , Araki Masatake , Takahama Kazuo , Yamaguchi Kohei , Tomita Kimio
Published: January 2014

Liddle’s syndrome is an autosomal dominant form of salt sensitive hypertension caused by mutations in the β or γ subunit of the epithelial sodium channel. Systemic mutagenesis studies revealed that a conserved PPPXY sequence (PY motif) of the C-terminus of the α, β, or γ subunits might be involved in the regulation of the channel activity. However, only two missense mutations in the PY motif of theβ subunit have been reported to cause Liddle’s syndrome. We sequenced the C-termini of the β and γ subunits of the epithelial sodium channel in a Japanese family clinically diagnosed as having Liddle’s syndrome and found a new missense mutation in the PY motif of the β subunit, P615S. Expression studies with P615S mutant in Xenopus oocytes resulted in an about 3-fold increase in the amiloride-sensitive sodium current compared to the wild type (p = 0.001). These findings provide further clinical evidence for the hypothesis that a conserved PY motif may be critically important for the regulation of the epithelial sodium channel.
Androgen Receptor Gene Expression in the Primate Ovary: Cellular Localization, Regulation, and Functional Correlations
Authors: Weil S. J. , Vendola K. , Zhou J. , Adesanya O. O. , Wang J. , Okafor J. , Bondy C. A.
Published: January 2014

Excess androgens are associated with a characteristic polyfollicular ovarian morphology; however, it is not known to what extent this problem is due to direct androgen action on follicular development vs. interference with gonadotropin release at the level of the pituitary or hypothalamus. To elucidate potential androgen effects on the ovary, we investigated the cellular localization of androgen receptor (AR) messenger ribonucleic acid (mRNA) in rhesus monkey using in situ hybridization. To investigate the regulation of ovarian AR gene expression, we compared the relative abundance of AR transcripts in monkeys during follicular and luteal phases of the menstrual cycle and in monkeys treated with testosterone. To assess potential functional consequences of AR expression in the primate ovary, we compared AR mRNA levels with indexes of follicular cell proliferation and apoptosis in serial sections from individual follicles.

AR mRNA expression was most abundant in granulosa cells of healthy preantral and antral follicles in the primate ovary. Theca interna and stromal cells also expressed AR mRNA, but to a lesser degree than granulosa cells. No significant cycle stage effects were noted in AR mRNA levels; however, larger numbers of animals would be necessary to definitively establish a cycle stage effect. AR mRNA level was significantly increased in granulosa cells and was decreased in theca interna and stromal cells of testosterone-treated monkeys. Importantly, granulosa cell AR mRNA abundance was positively correlated with expression of the proliferation-specific antigen Ki-67 (r = 0.91; P < 0.001) and negatively correlated with granulosa cell apoptosis (r = −0.64; P < 0.001).

In summary, these data show that primate ovary AR gene expression is most abundant in granulosa cells of healthy growing follicles, where its expression is up-regulated by testosterone. The positive correlation between granulosa AR gene expression and cell proliferation and negative correlation with programmed cell death suggests that androgens stimulate early primate follicle development.
Expression of Functional Prolactin Receptors in Nonpregnant Human Endometrium: Janus Kinase-2, Signal Transducer and Activator of Transcription-1 (STAT1), and STAT5 Proteins Are Phosphorylated after Stimulation with Prolactin
Authors: Jabbour H. N. , Critchley H. O. D. , Boddy S. C.
Published: January 2014

PRL is synthesized by decidualized endometrial stromal cells from the midsecretory phase in a nonconception cycle and throughout pregnancy. The exact role of PRL in the human endometrium remains to be elucidated; however, the pattern of expression supports a role for PRL during implantation and placentation. This study investigated the site and pattern of expression of PRL receptors in the nonpregnant human endometrium. In situ hybridization and immunohistochemistry localized expression of the receptor in the glandular epithelium and a subset of stromal cells of the endometrium. As judged by the intensity of staining, expression of the receptor was dramatically up-regulated during the secretory phase. Expression of the PRL receptor gene in the endometrium from the secretory phase of the menstrual cycle was confirmed by ribonuclease protection assay using 50μ g total ribonucleic acid. Phosphorylation of Janus kinase-2 (JAK2), STAT1 (signal transducer and activator of transcription-1), and STAT5 proteins in response to PRL was investigated to establish the signaling pathway of PRL in the human endometrium. Endometrial tissue was collected during the secretory phase of the menstrual cycle and incubated in the presence of 100 ng/mL human PRL for 0, 5, 10, and 20 min. JAK2 phosphorylation was induced by PRL at 5 min, whereas STAT1 and STAT5 phosphorylation was apparent 20 min after stimulation with PRL. Immunohistochemistry localized the JAK/STAT proteins in the glandular epithelial cells and a subset of stromal cells, as was observed for the PRL receptor. Secretory phase stromal and glandular cells cultured separately and in the presence or absence of 100 ng/mL PRL confirmed the PRL-induced phosphorylation of JAK2/STAT proteins, at least in the glandular compartment. These studies demonstrate an up-regulation of expression of functional PRL receptors during the secretory phase of the menstrual cycle. Further, decidual PRL through a paracrine mechanism may influence glandular epithelial function/secretions and direct gene transcription through the JAK/STAT pathway. The target genes activated by PRL in the glandular epithelium of the nonpregnant human endometrium remain to be elucidated.
Effect of Thyroid Dysfunction on High-Density Lipoprotein Subfraction Metabolism: Roles of Hepatic Lipase and Cholesteryl Ester Transfer Protein1
Authors: Tan K. C. B. , Shiu S. W. M. , Kung. A. W. C.
Published: January 2014

abstract

To investigate the effect of thyroid dysfunction on high-density lipoprotein (HDL) metabolism, we measured HDL subfractions, apolipoprotein A-I containing particles (LpA-I and LpA-I:A-II), and the activities of enzymes involved in the remodeling and metabolism of HDL[ namely hepatic lipase (HL), lipoprotein lipase, and cholesteryl ester transfer protein (CETP)] in 18 hyperthyroid and 17 hypothyroid patients before and after treatment. HDL was subfractionated by density gradient ultracentrifugation, and LpA-I was analyzed by electroimmunodiffusion. The major changes were found in the HDL2 subfraction and in LpA-I particles. HDL2-C and LpA-I were reduced in hyperthyroidism (P < 0.01, P < 0.05, respectively) and increased in hypothyroidism (both P < 0.05) compared with their respective euthyroid matched controls. Changes in HDL2-cholesterol were reversed after treatment in both hyper- and hypothyroid patients, and LpA-I also decreased in the hypothyroid patients after treatment. HL (P < 0.05) and CETP activities (P < 0.05) were elevated in hyperthyroidism and reduced in hypothyroidism (P < 0.05, P < 0.01 respectively) and both were related to free T4 levels. The changes in HDL2-C and LpA-I correlated significantly with changes in HL after treatment but not with CETP or lipoprotein lipase. In summary, HDL metabolism was altered in thyroid dysfunction, and the effect of thyroid hormone on HDL was mediated mainly via its effect on HL activity.
Thresholds for Surgery and Surgical Outcomes for Patients with Primary Hyperparathyroidism: A National Survey of Endocrine Surgeons
Authors: Sosa Julie Ann , Powe Neil R. , Levine Michael A. , Udelsman Robert , Zeiger Martha A.
Published: January 2014

abstract

A 1991 NIH Consensus Development Conference statement provided recommendations for the management of patients with asymptomatic and minimally symptomatic primary hyperparathyroidism (1° HPT), but adherence to these guidelines has not been documented. We conducted a cross-sectional survey of North American members of the American Association of Endocrine Surgeons inquiring about surgeon and 1° HPT patient characteristics, thresholds for surgery, and clinical outcomes. Multivariate regression was used to assess the relationship of physician characteristics to practice patterns and outcomes.

Of 190 surgeons surveyed, 147 (77%) responded; 109 provided complete responses (57%). These surgeons spend 66% of their time in patient care and perform an average of 33 (range, 1–130) parathyroidectomies/yr. More than 72% of 1° HPT patients who underwent surgery were asymptomatic or minimally symptomatic. High volume surgeons (>50 cases/yr) had significantly lower thresholds for surgery with respect to abnormalities in preoperative creatinine clearance, bone densitometry changes, and levels of intact PTH and urinary calcium compared to their low volume colleagues (1–15 cases/yr). Overall reported surgical cure rates were 95.2% after primary operation and 82.7% after reoperation. Compared to high volume surgeons, low volume endocrine surgeons had significantly higher complication rates after primary operation (1.9% vs. 1.0% respectively; P < 0.01) and reoperation (3.8% vs. 1.5%; P < 0.001) as well as higher in-hospital mortality rates (1.0% vs. 0.04%; P < 0.05).

Endocrine surgeons operate on a large number of asymptomatic or minimally symptomatic 1° HPT patients. Even among a group of highly experienced surgeons who typically see patients after referral from endocrinologists, clinical outcomes and criteria for surgery vary widely and appear to be associated with surgeon experience. Their criteria for surgery diverge from NIH guidelines. These results implore the endocrine community to examine the evidential basis for decisions made in the management of 1° HPT.
Adrenocortical Overexpression of Gastric Inhibitory Polypeptide Receptor Underlies Food-Dependent Cushing’s Syndrome1
Authors: N’Diaye Nina , Tremblay Johanne , Hamet Pavel , De Herder Wouter W. , Lacroix André
Published: January 2014

abstract

Abnormal responsiveness of adrenocortical cells to gastric inhibitory polypeptide (GIP) in food-dependent Cushing’s syndrome suggested that adrenal expression of ectopic, overexpressed, or mutated GIP receptor (GIPR) underlies this syndrome. The expression of GIPR was studied by RT-PCR in human adrenal tissues from two patients with GIP-dependent Cushing’s syndrome (adenoma, bilateral hyperplasia), five fetal or adult controls, one patient with Cushing’s disease, and four patients with non-food-dependent cortisol-secreting adenomas or bilateral hyperplasias and compared to that in normal pancreas. Hybridization of the RT-PCR-amplified ribonucleic acids with the human GIPR complementary DNA showed an overexpression of GIPR in the adrenals of the two GIP-dependent Cushing’s syndrome patients compared to that in normal adrenal tissues (2–3 orders of magnitude) or pancreas (10-fold); no signal could be seen in adrenal adenomas or macronodular hyperplasia from cases of non-food-dependent Cushing’s syndrome. No mutation of the GIPR was identified by sequencing the full-length receptor in GIP-dependent adrenal tissue. New alternative spliced isoforms of the GIPR were found, but are identical in GIP-dependent and normal adrenal tissues. Incubation of adrenal cells with GIP stimulates cortisol secretion in GIP-dependent, but not in normal fetal, adult, or non-food-dependent Cushing’s syndrome, adrenals. We conclude that the GIPR overexpression and its coupling to steroidogenesis underlie GIP-dependent Cushing’s syndrome.
Deleterious Missense Mutations and Silent Polymorphism in the Human 17β-Hydroxysteroid Dehydrogenase 3 Gene (HSD17B3)1
Authors: Moghrabi Nabil , Hughes Ieuan A. , Dunaif Andrea , Andersson Stefan
Published: January 2014

abstract

Isozymes of 17β-hydroxysteroid dehydrogenase (17βHSD) regulate levels of bioactive androgens and estrogens in a variety of tissues. For example, the 17βHSD type 3 isozyme catalyzes the conversion of the inactive C19-steroid androstenedione to the biologically active androgen, testosterone, in the testis. Testosterone is essential for the correct development of male internal and external genitalia; hence, deleterious mutations in the HSD17B3 gene give rise to a rare form of male pseudohermaphroditism termed 17βHSD deficiency. Here, 2 additional missense mutations in the HSD17B3 gene in subjects with 17βHSD deficiency are described. One mutation (A56T) impairs enzyme function by affecting NADPH cofactor binding. A second mutation (N130S) led to complete loss of enzyme activity. Also, a single base pair polymorphism in exon 11 of the HSD17B3 gene is described. The polymorphic A allele encodes a protein with a serine rather than a glycine at position 289 (GGT → AGT). The frequency of the G allele (Gly) was 0.94, and that of the A allele (Ser) was 0.06. No difference in the frequencies of the G and A alleles was detected in 32 apparently normal women and 46 women with polycystic ovary syndrome. Enzymes bearing either glycine or serine at this position have similar substrate specificities and kinetic constants. The current findings boost to 16 the number of mutations in the HSD17B3 gene that impair testosterone synthesis and cause male pseudohermaphroditism, and add 1 apparently silent polymorphism to this tally.
Differential Expression of Estrogen Receptor-β (ERβ) in Human Pituitary Tumors: Functional Interactions with ERα and a Tumor-Specific Splice Variant1
Authors: Chaidarun Sushela S. , Swearingen Brooke , Alexander Joseph M.
Published: January 2014

The mitogenic and regulatory effects of estrogen (E2) in adenohypophysial cells are known to be mediated through the nuclear estrogen receptor (ERα). Expression of ERα and several of its messenger ribonucleic acid (RNA) alternate splice variants has been shown to be restricted to prolactinomas and gonadotroph tumors. However, little is known about gene expression patterns of the novel nuclear hormone receptor ERβ in the neoplastic pituitary. ERβ has high homology to ERα in the DNA- and ligand-binding domains, but encodes a distinct transcriptional activating function-1 (AF-1) domain. Using RT-PCR analysis of total RNA from 38 human pituitary adenomas, we found that ERβ messenger RNA was coexpressed with ERα and its splice variants in 60% of prolactinomas, 100% of mixed GH/PRL tumors, and 29% of gonadotroph tumors. ERβ gene expression was not limited to ERα-positive tumor subtypes, however, and was also found in 100% of null cell tumors, 80% of somatotroph tumors, and 60% of corticotroph tumors. Because ERβ is coexpressed with ERα and its splice variants in prolactinomas and gonadotroph tumors, we functionally characterized the potential interactions between ERβ and ERα. We also examined the potential cooperative effects on ERβ-mediated gene expression of a tumor-specific truncated Δ5ERα splice variant that has been shown to be coexpressed in the majority of ERα-positive tumors. This exon 5 splice variant encodes the AF-1 domain as well as regions critical for DNA binding and nuclear localization, but lacks the ligand-binding and AF-2 domains. Mammalian expression vectors encoding ERα, Δ5ERα, and/or ERβ complementary DNAs were transiently transfected along with an E2 response element promoter-luciferase (ERELuc) reporter into human ERα/ERβ-negative osteosarcoma U2-OS cells. ERβ was less potent than ERα in activating E2-stimulated ERELuc activity (4- vs. 14-fold relative to basal control levels). However, when Δ5ERα was coexpressed with ERβ or ERα, E2-stimulated ERELuc activity was markedly increased to 8- and 57-fold, respectively, relative to basal control levels when each full-length isoform was expressed alone. Finally, coexpression of ERβ with ERα did not significantly alter the E2-stimulated ERELuc activity induced by ERα alone. Cotreatment with tamoxifen markedly inhibited all E2-stimulated ERELuc responses to baseline levels. Together, these data suggest that ERβ has a minor role in mediating E2 responses in ERα-positive tumors, but may be the main mediator of E2-stimulated gene expression when expressed alone in somatotroph, corticotroph, and null cell tumors. This low, but significant, level of ERβ trans-activation potential may be enhanced by coexpression of Δ5ERα in neoplastic pituitary. Therefore, E2-mediated gene expression in normal and neoplastic pituitary appears to be highly dependent on the expression of ERα and ERβ isoforms, which have varying transcriptional activities.
Decreased Bone Formative and Enhanced Resorptive Markers in Human Immunodeficiency Virus Infection: Indication of Normalization of the Bone-Remodeling Process during Highly Active Antiretroviral Therapy1
Authors: Aukrust Pål , Haug Charlotte J. , Ueland Thor , Lien Egil , Müller Fredrik , Espevik Terje , Bollerslev Jens , Frøland Stig S.
Published: January 2014

As cytokines and 1,25-dihydroxyvitamin D [1,25-(OH)2D] appear to have an important role in bone homeostasis, we examined the possibility that human immunodeficiency virus (HIV)-infected patients, characterized by enhanced levels of proinflammatory cytokines and 1,25-(OH)2D deficiency, have disturbed bone metabolism by analyzing serum markers of bone formation (osteocalcin) and bone resorption (C-telopeptide) in 73 HIV-infected patients. HIV-infected patients with advanced clinical and immunological disease and high viral load were characterized by increased C-telopeptide and particularly by markedly depressed osteocalcin levels. HIV-infected patients had enhanced activation of the TNF system. Serum concentrations of p55 and p75-TNF receptors were negatively correlated with osteocalcin, and p75-TNF receptor was positively correlated with C-telopeptide. HIV-infected patients with advanced disease also had decreased serum concentrations of 1,25-(OH)2D, but this parameter was not correlated with osteocalcin or C-telopeptide. During 24 months with highly active antiretroviral therapy there was a marked rise in serum osteolcalcin levels together with a profound fall in viral load and TNF components and a marked rise in CD4+ T cell counts. Also, there was a shift from no correlation to a significant correlation between osteocalcin and C-telopeptide levels during such therapy. The present study suggests disturbed bone formation and resorption during HIV infection. Our findings indicating synchronization of bone remodeling during highly active antiretroviral therapy may represent a previously unrecognized beneficial effect of such therapy and expand our knowledge of the interactions between cytokines and bone in the bone-remodeling process.
Analysis of Meiosis in Intratesticular Germ Cells from Subjects Affected by Classic Klinefelter’s Syndrome
Authors: Foresta Carlo , Galeazzi Carlo , Bettella Andrea , Marin Paola , Rossato Marco , Garolla Andrea , Ferlin Alberto
Published: January 2014

Azoospermic subjects affected by Klinefelter’s syndrome may occasionally show the presence of intratesticular residual foci of spermatogenesis, and the retrieval of mature spermatozoa from the testis may permit fertility and paternity by means of intracytoplasmic sperm injection.

Previous studies have demonstrated that these subjects show the presence of an increased incidence of hyperaploid spermatozoa. Here we analyzed, by fluorescence in situ hybridization using specific probes for chromosomes 8, X, and Y, the spermatogenic process and the meiotic progression of 47,XXY germ cells retrieved by fine needle aspiration of the testis in ten azoospermic patients affected by classic Klinefelter’s syndrome. All patients had lower testicular volume, higher gonadotropins, and lower testosterone plasma levels compared with control subjects. Cytological analysis of the testicular cells retrieved by fine needle aspiration showed the presence of Sertoli cells only in eight subjects, while germ cells were observed in two patients. In each patient Sertoli cells showed a 47,XXY karyotype, and the same chromosome pattern was observed in spermatogonia and primary spermatocytes of patients presenting a residual spermatogenesis. Secondary spermatocytes, spermatids, and mature spermatozoa showed different sex chromosome patterns, reflecting their origin from 47,XXY spermatogonia.

In conclusion, this study demonstrated that, in subjects affected by Klinefelter’s syndrome, residual germ cells may be present in the testis and that 47,XXY spermatogonia are able to undergo and complete the spermatogenic process leading to mature spermatozoa. These data further suggest the need to evaluate the sex chromosome status of sperm from patients affected by Klinefelter’s syndrome undergoing assisted reproductive techniques.
Ethnicity and Migration as Determinants of Human Prostate Size*
Authors: Jin B. , Turner L. , Zhou Z. , Zhou E. L. , Handelsman D. J.
Published: January 2014

The roles of ethnicity and migration in determining the size of human prostate zones during midlife were explored. Prostate size was measured by planimetric ultrasound in 163 men residing in Sydney who were either Australian non-Chinese (AR; n = 116) or Chinese migrants (ACM; n = 47) and had lived in Australia for a median of 7.3 yr (range, 0.2–25 yr). These were compared with Chinese men residing in China (CR; n = 210). Central and total prostate volumes were estimated by a single observer using the same equipment at both sites. After adjustment for age, central and total prostate volumes were significantly smaller, and plasma prostate-specific antigen and 5α-dihydrotestosterone (DHT) concentrations and International Prostate Syndrome Scores were significantly lower, in CR compared with either ACM or AR, whereas the scores of the latter two groups were similar. Almost all of the population difference in total prostate volumes could be accounted for by differences in central prostate volumes. The strongest correlates of age-adjusted prostate volume were prostate-specific antigen and DHT, the latter presumably reflecting the quantitative importance of prostatic stromal type II 5α-reductase activity to circulating DHT concentrations. Sex hormone-binding globulin concentrations were significantly higher in CR and significantly lower in ACM compared with those in AR, but the significance of these observations is unclear. These findings highlight the importance of the central zone of the prostate as well as provide evidence for an environmental factor influencing prostate growth. This factor operates over a relatively short time period compared with the evolution of prostate disease. Hence, this study provides evidence that ethnicity and geographical factors, such as migration, can influence the growth of the normal human prostate during midlife and may facilitate future studies of the origins and pathogenesis of human prostate disease.
Endogenous Sex Hormones and Cognitive Function in Older Men*
Authors: Barrett-Connor Elizabeth , Goodman-Gruen Deborah , Patay Brad
Published: January 2014

The objective of this study was to determine whether endogenous sex hormone levels predict cognitive function in older men. Our study design was an exploratory analysis in a population-based cohort in Rancho Bernardo, California. The study participants were 547 community-dwelling men 59–89 yr of age at baseline who were not using testosterone or estrogen therapy. Between 1984 and 1987, sera were collected for measurement of endogenous total and bioavailable testosterone and estradiol levels. Between 1988 and 1991, 12 standard neuropsychological instruments were administered, including two items from the Blessed Information-Memory-Concentration (BIMC) Test, three measures of retrieval from the Buschke-Fuld Selective Reminding Test, a category fluency test, immediate and delayed recall from the Visual Reproduction Test, the Mini-Mental State Examination with individual analysis of the Serial Sevens and the “World” Backwards components, and the Trail-Making Test Part B. In age- and education-adjusted analyses, men with higher levels of total and bioavailable estradiol had poorer scores on the BIMC Test and Mini-Mental State Examination. Men with higher levels of bioavailable testosterone had better scores on the BIMC Test and the Selective Reminding Test (long-term storage). Five associations were U-shaped: total testosterone and total and bioavailable estradiol with the BIMC Test; bioavailable testosterone with the “World” test; and total estradiol with the Trail-Making Test. All associations were relatively weak but independent of age, education, body mass index, alcohol use, cigarette smoking and depression. In these older men, low estradiol and high testosterone levels predicted better performance on several tests of cognitive function. Linear and nonlinear associations were also found, suggesting that an optimal level of sex hormones may exist for some cognitive functions.
Modulation of 11β-Hydroxysteroid Dehydrogenase Isozymes by Growth Hormone and Insulin-Like Growth Factor: In Vivo and In Vitro Studies1
Authors: Moore J. S. , Monson J. P. , Kaltsas G. , Putignano P. , Wood P. J. , Sheppard M. C. , Besser G. M. , Taylor N. F. , Stewart P. M.
Published: January 2014

The interconversion of hormonally active cortisol (F) and inactive cortisone (E) is catalyzed by two isozymes of 11β-hydroxysteroid dehydrogenase (11βHSD), an oxo-reductase converting E to F (11βHSD1) and a dehydrogenase (11βHSD2) converting F to E. 11βHSD1 is important in mediating glucocorticoid-regulated glucose homeostasis and regional adipocyte differentiation. Earlier studies conducted with GH-deficient subjects treated with replacement GH suggested that GH may modulate 11βHSD1 activity.

In 7 acromegalic subjects withdrawing from medical therapy (Sandostatin-LAR; 20–40 mg/month for at least 12 months), GH rose from 7.1 ± 1.5 to 17.5 ± 4.3 mU/L (mean ± se), and insulin-like growth factor I (IGF-I) rose from 43.0 ± 8.8 to 82.1 ± 13.7 nmol/L (both P < 0.05) 4 months after treatment. There was a significant alteration in the normal set-point of F to E interconversion toward E. The fall in the urinary tetrahydrocortisols/tetrahydocortisone ratio (THF+allo-THF/THE; 0.82 ± 0.06 to 0.60 ± 0.06; P < 0.02) but unaltered urinary free F/urinary free E ratio (a marker for 11βHSD2 activity) suggested that this was due to inhibition of 11βHSD1 activity. An inverse correlation between GH and the THF+allo-THF/THE ratio was observed (r = −0.422; P < 0.05). Conversely, in 12 acromegalic patients treated by transsphenoidal surgery (GH falling from 124 ± 49.2 to 29.3 ± 15.4 mU/L; P < 0.01), the THF+allo-THF/THE ratio rose from 0.53 ± 0.06 to 0.63 ± 0.07 (P < 0.05). Patients from either group who failed to demonstrate a change in GH levels showed no change in the THF+allo-THF/THE ratio.

In vitro studies conducted on cells stably transfected with either the human 11βHSD1 or 11βHSD2 complementary DNA and primary cultures of human omental adipose stromal cells expressing only the 11βHSD1 isozyme indicated a dose-dependent inhibition of 11βHSD1 oxo-reductase activity with IGF-I, but not GH. Neither IGF-I nor GH had any effect on 11βHSD2 activity.

GH, through an IGF-I-mediated effect, inhibits 11βHSD1 activity. This reduction in E to F conversion will increase the MCR of F, and care should be taken to monitor the adequacy of function of the hypothalamo-pituitary-adrenal axis in acromegalic subjects and in GH-deficient, hypopituitary patients commencing replacement GH therapy. Conversely, enhanced E to F conversion occurs with a reduction in GH levels; in liver and adipose tissue this would result in increased hepatic glucose output and visceral adiposity, suggesting that part of the phenotype currently attributable to adult GH deficiency may be an indirect consequence of its effect on tissue F metabolism via 11βHSD1 expression.
Expression of Hyaluronan Synthase Messenger Ribonucleic Acids and Their Induction by Interleukin-1β in Human Orbital Fibroblasts: Potential Insight into the Molecular Pathogenesis of Thyroid-Associated Ophthalmopathy1
Authors: Kaback Lee A. , Smith Terry J.
Published: January 2014

The disordered accumulation of hyaluronan, a nonsulfated glycosaminoglycan, is a hallmark feature of the tissue remodeling observed in thyroid-associated ophthalmopathy (TAO). Orbital fibroblasts have been shown to exhibit substantial up-regulation of hyaluronan synthesis when activated with proinflammatory cytokines such as interleukin-1β (IL-1β). Recently, three members of the hyaluronan synthase (HAS) gene family were cloned. Here we report that IL-1β can dramatically and consistently induce in orbital fibroblasts the expression of HAS2 in the five orbital strains examined. HAS3 messenger ribonucleic acid (mRNA) was also detectable in all these strains by RT-PCR under both control and IL-1β-treated conditions. In contrast, HAS1 mRNA was detected by Northern blot analysis in only one of the strains treated with IL-1β, but in three of five strains examined by RT-PCR. These HAS inductions by the cytokine were time dependent and could be attenuated with dexamethasone and cycloheximide. They were accompanied by an increased incorporation of[ 3H]glucosamine into hyaluronan, and dexamethasone could attenuate induction of macromolecular synthesis as well. Our observations suggest that the cytokine-dependent induction of the HAS genes in orbital fibroblasts may be the molecular basis at least in part for the increased accumulation of hyaluronan, driven by immunocompetent cells, in orbital connective tissue and the extraocular muscles in TAO.
High Prevalence of RET/PTC Rearrangements in Ukrainian and Belarussian Post-Chernobyl Thyroid Papillary Carcinomas: A Strong Correlation between RET/PTC3 and the Solid-Follicular Variant1
Authors: Thomas G. A. , Bunnell H. , Cook H. A. , Williams E. D. , Nerovnya A. , Cherstvoy E. D. , Tronko N. D. , Bogdanova T. I. , Chiappetta G. , Viglietto G. , Pentimalli F. , Salvatore G. , Fusco A. , Santoro M. , Vecchio G.
Published: January 2014

A sharp increase in the incidence of pediatric thyroid papillary cancer was documented after the Chernobyl power plant explosion. An increased prevalence of rearrangements of the RET protooncogene (RET/PTC rearrangements) has been reported in Belarussian post-Chernobyl papillary carcinomas arising between 1990 and 1995. We analyzed 67 post-Chernobyl pediatric papillary carcinomas arising in 1995–1997 for RET/PTC activation: 28 were from Ukraine and 39 were from Belarus. The study, conducted by a combined immunohistochemistry and RT-PCR approach, demonstrated a high frequency (60.7% of the Ukrainian and 51.3% of the Belarussian cases) of RET/PTC activation. A strong correlation was observed between the solid-follicular subtype of papillary carcinoma and the RET/PTC3 isoform: 19 of the 24 RET/PTC-positive solid-follicular carcinomas harbored a RET/PTC3 rearrangement, whereas only 5 had a RET/PTC1 rearrangement. Taken together these results support the concept that RET/PTC activation plays a central role in the pathogenesis of thyroid papillary carcinomas in both Ukraine and Belarus after the Chernobyl accident.
IMAGe, a New Clinical Association of Intrauterine Growth Retardation, Metaphyseal Dysplasia, Adrenal Hypoplasia Congenita, and Genital Anomalies
Authors: Vilain Eric , Le Merrer Martine , Lecointre Claudine , Desangles Francois , Kay Mark A. , Maroteaux Pierre , McCabe Edward R. B.
Published: January 2014

We report three boys with adrenal hypoplasia congenita (AHC) and additional findings that represent a new syndrome, IMAGe: Intrauterine growth retardation, Metaphyseal dysplasia, AHC, and Genital anomalies. Each presented shortly after birth with growth retardation and severe adrenal insufficiency. Each of the three patients had mild dysmorphic features, bilateral cryptorchidism, a small penis, and hypogonadotropic hypogonadism. Skeletal surveys revealed metaphyseal dysplasia in all three and epiphyseal dysplasia in two. The patients had documented or suspected hypercalciuria and/or hypercalcemia, resulting in nephrocalcinosis in one and in prenatal liver and spleen calcifications in another. AHC presents most often either as an isolated abnormality, caused by mutations in the DAX1 gene, or as part of an Xp21 contiguous gene syndrome, caused by a deletion of the Duchenne muscular dystrophy, glycerol kinase, and DAX1 genes. All three patients with the IMAGe association had normal creatine kinase levels and no evidence of glycerol kinase deficiency. Sequence analysis of DNA from these patients revealed no mutation in the DAX1- or steroidogenic factor-1-coding sequences, nor was a deletion of DAX1 detected. Identification of the molecular basis of the IMAGe association will give new insight into the pathogenesis of this syndromic relationship involving bone, adrenal cortical, and pituitary development.