bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-Acting Peptidomimergic Control of Gigantism Caused by Pituitary Acidophilic Stem Cell Adenoma*
Authors: Maheshwari Hiralal G. , Prezant Toni R. , Herman-Bonert Vivien , Shahinian Hrayr , Kovacs Kalman , Melmed Shlomo 
Published: January 2014

AbstractGigantism is caused by GH hypersecretion occurring before epiphyseal long bone closure and usually is associated with pituitary adenoma. A 15-yr-old female patient presented with accelerated growth due to a large pituitary tumor that was surgically resected to relieve pressure effects. Second surgery to remove residual tumor tissue was followed by administration of octreotide LAR, a long-acting depot somatostatin analog, together with long-acting cabergoline. Height was over the 95th percentile, with evidence of a recent growth spurt. Serum GH levels were more than 60 ng/mL (normal, &lt;10 ng/mL) with no suppression to 75 g oral glucose, and serum PRL (&gt;8000 ng/mL; normal, &lt;23 ng/mL) and insulin-like growth factor I levels (845 ng/mL; age-matched normal, 242–660 ng/mL) were elevated. Histology, immunostaining, and electron microscopy demonstrated a pituitary acidophil stem cell adenoma. Tumor tissue expressed both somatostatin receptor type 2 and dopamine receptor type 2. The Gs α subunit, GHRH receptor, and MEN1 genes were intact, and tumor tissue abundantly expressed pituitary tumor transforming gene (PTTG). Serum GH and PRL levels were controlled after two surgeries, and with continued cabergoline and octreotide LAR GH, PRL, and insulin-like growth factor I levels were normalized. In conclusion, administration of long-acting somatostatin analog every 4 weeks in combination with a long-acting dopamine agonist biweekly controlled biochemical parameters and accelerated growth in a patient with gigantism caused by a rare pituitary acidophil stem cell adenoma.
Antibodies to Glutamic Acid Decarboxylase and Peripheral Nerve Function in Type 1 Diabetes*
Authors: Hoeldtke Robert D. , Bryner Kimberly D. , Hobbs Gerald R. , Horvath Gabriella G. , Riggs Jack E. , Christie Ian , Ganser Gary , Marcovina Santica M. , Lernmark Ake 
Published: January 2014

AbstractAutoimmune mechanisms have been implicated in the pathophysiology of diabetic neuropathy. We studied the association between glutamic acid decarboxylase (GAD65) and islet cell (IA-2) autoantibodies as well as autoantibodies to the autonomic nervous system and peripheral nerve function in recent onset type 1 diabetes. Thirty-seven patients (27 females and 10 males) enrolled 2–22 months after diagnosis. Humoral factors, glycemic control, and peripheral nerve function were measured annually for 3 yr.Patients with high GAD65Ab had worse glycemic control and higher insulin requirements. Patients with high GAD65Ab had slower motor nerve conduction velocities in the median, ulnar, and peroneal nerves (P &lt; 0.025 for each nerve). The mean motor nerve conduction velocity Z scores at the time of the third evaluation was 0.341 ± 0.25 for the low GAD65Ab patients and −0.600 ± 0.25 for the high GAD65Ab patients (P &lt; 0.01). Similar differences between the low and high GAD65Ab groups were observed for F wave latencies, thermal threshold detection, and cardiovascular autonomic function. The composite peripheral nerve function Z scores in the low GAD65Ab patients were 0.62 ± 11, 0.71 ± 0.19, and 0.21 ± 0.14 at the first, second, and third evaluations, significantly different from those in the high GAD65Ab patients in whom they were −0.35 ± 0.15, −0.46 ± 0.18, and −0.42 ± 0.16 (P &lt; 0.001).In summary, GAD65Ab in patients with recent onset type 1 diabetes are associated with worse glycemic control and slightly worse peripheral nerve function. Although the latter remained within normal limits and none of the patients had clinical neuropathy, the GAD65Ab-related differences in composite peripheral nerve function were highly significant (P &lt; 0.001) and could not be attributed to GAD65Ab-related differences in glycemic control.
A Five-Base Pair Deletion in the Sedlin Gene Causes Spondyloepiphyseal Dysplasia Tarda in a Six-Generation Arkansas Kindred*
Authors: Mumm Steven , Christie Paul T. , Finnegan Patrick , Jones Jonathan , Dixon Peter H. , Pannett Anna A. J. , Harding Brian , Gottesman Gary S. , Thakker Rajesh V. , Whyte Michael P. 
Published: January 2014

Abstract
A six-generation kindred from Arkansas with X-linked recessive spondyloepiphyseal dysplasia tarda (SEDT) was investigated by genetic linkage and mutation analysis. SEDT had been mapped on the X-chromosome (Xp22.2), and the clinical and radiographic evolution of this kindred had been published.
Linkage analysis proved informative for all five polymorphic markers tested, and DXS987 and DXS16 co-segregated with the Arkansas kindred (peak logarithm of the odds scores, 3.54 and 3.36, respectively). Subsequently, dinucleotide deletion in a new gene designated “sedlin” was reported to cause SEDT in three families. In an affected man and obligate carrier woman in the Arkansas kindred, we found a 5-bp deletion in exon 5 of sedlin. The defect causes a frameshift, resulting in eight missense amino acids and premature termination. The 5-bp deletion was then demonstrated to segregate with SEDT in the four living generations, including eight affected males and nine obligate carrier females. Furthermore, the deletion was identified in four females who potentially were heterozygous carriers for SEDT. The mutation was not detected in the two young sons of the consultand (believed to be a carrier because of her subtle radiographic skeletal changes and then shown to have the deletion), but they were too young for x-ray diagnosis.
Identification of a defect in sedlin in this SEDT kindred enables carrier detection and presymptomatic diagnosis and reveals an important role for this gene in postnatal endochondral bone formation.
A Novel Mutation of the Autoimmune Regulator Gene in an Italian Kindred with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy, Acting in a Dominant Fashion and Strongly Cosegregating with Hypothyroid Autoimmune Thyroiditis
Authors: Cetani Filomena , Barbesino Giuseppe , Borsari Simona , Pardi Elena , Cianferotti Luisella , Pinchera Aldo , Marcocci Claudio 
Published: January 2014

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is a rare autosomal recessive disorder characterized by hypoparathyroidism, adrenal failure, chronic mucocutaneous candidiasis, and ectodermal dystrophies and other organ-specific autoimmune diseases. Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is caused by mutations of the autoimmune regulator gene.
We identified an Italian family with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy and a pattern of inheritance suggestive of a dominant mechanism. Serological and clinical studies showed a high prevalence of hypothyroid autoimmune thyroiditis in affected members with classical autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy.
Direct sequencing of the entire coding region of the autoimmune regulator gene revealed the presence in the proband of a novel missense (G228W) mutation in exon 6 in a heterozygous state. The same heterozygous mutation was identified in all family members with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy and/or hypothyroid autoimmune thyroiditis. None of the unaffected family members and 50 unrelated Italian controls carried the mutation.
In contrast with all other autoimmune regulator mutations reported in families, the novel G228W mutation acts in a dominant fashion in our family, as only one heterozygous mutation was found in the entire coding sequence of the autoimmune regulator gene in the proband. Moreover, analysis of the family tree showed direct transmission of the hypothyroid autoimmune thyroiditis/polyendocrinopathy-candidiasis-ectodermal dystrophy phenotype to the offspring in each generation in the absence of consanguinity, further supporting a dominant inheritance. The G228W closely cosegregated with hypothyroid autoimmune thyroiditis in our family, whereas a low penetrance of the full autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy phenotype was observed.
In conclusion, we report a novel mutation of the autoimmune regulator gene in a family with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, closely cosegregating with hypothyroid autoimmune thyroiditis. The G228W mutation acts in a dominant fashion and may shed light on the structure-function relationship of the autoimmune regulator protein.
Oral Glucose Augments the Counterregulatory Hormone Response during Insulin-Induced Hypoglycemia in Humans1
Authors: Heptulla Rubina A. , Tamborlane William V. , Ma Tony Y.-Z. , Rife Fran , Sherwin. Robert S. 
Published: January 2014

It has been suggested that the counterregulatory hormone (CRH) response to acute hypoglycemia is triggered via glucose sensors situated in either the hypothalamus or the portohepatic area. If the latter were critical during hypoglycemia, one would anticipate that ingestion of glucose, by raising glucose levels in the portal circulation, should attenuate CRH responses previously described in animal studies. To evaluate the effect of raising portal, but not peripheral, glucose levels during insulin-induced hypoglycemia, we performed hypoglycemic clamp studies in five healthy adult males on two occasions. On one occasion, subjects received oral glucose (OG) (25 g) during hypoglycemia; and on one occasion, noncarbohydrate-containing drink of equal volume, while maintaining plasma glucose at 55 ± 2 mg/dL (3.08 mmol/L).
As a result, there were no significant differences in systemic plasma glucose levels between the two hypoglycemic clamp studies, and basal CRH concentrations were also similar. As expected, there was a brisk rise in all CRH during the control (hypoglycemia+noncarbohydrate drink) study. In the experimental study, administration of OG (hypoglycemia+OG), to raise intraportal glucose levels during systemic hypoglycemia, did not attenuate CRH responses. Indeed, OG enhanced the rise in epinephrine, glucagon, and GH.
Increases in cortisol and norepinephrine did not differ between the two studies.
Therefore, our data suggest that increasing the level of glucose in the portal vein above that in the systemic circulation, during hypoglycemia, enhances (rather than suppresses) CRH responses. Thus, ingestion of glucose may reverse hypoglycemia directly by provision of substrate, as well as indirectly by stimulating counteregulatory mechanisms.
The Impact of Irradiation on Growth Hormone Responsiveness to Provocative Agents Is Stimulus Dependent: Results in 161 Individuals with Radiation Damage to the Somatotropic Axis1
Authors: Lissett C. A. , Saleem S. , Rahim A. , Brennan B. M. D. , Shalet S. M. 
Published: January 2014

GH provocative tests remain the mainstay for the diagnosis of GH deficiency and at present the insulin tolerance test (ITT) is the gold standard. There are, however, a variety of other stimulation tests used in clinical practice. Each necessitates the use of a specific cut-off derived from normative data, but there remains a widely held view that the implications from a “failed” test are independent of the nature of the stimulus. We sought to examine whether this is the case in individuals with evidence of radiation damage to the somatotropic axis.
One hundred and sixty-one nonacromegalic patients were identified who had undergone an arginine stimulation test (AST) and an ITT within a 3-month period as part of routine testing between 1975 and 1999. They were divided into those tested before (n = 81; 48 males) and those tested after (n = 80; 36 males) completion of growth and puberty. Patients were considered for inclusion in the study if they had a history of cranial irradiation and a GH response to one provocative test of less than 8 μg/L, taken as indicating that some damage to the GH axis may have occurred. The patients were compared with 2 control groups. The first comprised 35 adults (18 males) and the second consisted of 16 prepubertal children (10 males).
The median peak (range) GH response to the ITT was significantly greater (P &lt; 0.0001) than that to the AST in the adult controls: 24.9 (4.1–76.9) vs. 12.2 (0.88–35.0)μ g/L, respectively. However, in the patients the GH responses were similar (P = 0.28): 2.2 (0.2–25.7) vs. 1.4 (0.2–12.8) μg/L to the ITT and AST, respectively. In contrast to the pattern seen in the adult controls, the response to an ITT in childhood controls was of similar magnitude (P = 0.5) to that to the AST: 17.5 (8.1–40.0) vs. 19.4 (7.3–53.8) μg/L, respectively. However in the patients, the GH response to the AST was greater than that to the ITT (P &lt; 0.0001): 4.3 (0.7–17.2) vs. 3.0 (0.4–18.1) μg/L, respectively.
In summary, we have shown that the impact of irradiation on GH responsiveness to provocative agents is stimulus dependent. The GH response to an AST appears to be more resistant to the effects of irradiation than that to the ITT. When investigating the impact of irradiation on GH secretory status, the GH response to an AST may be a less sensitive guide to the functional ability of the GH axis.
The Effect of Aromatase Inhibition on Sex Steroids, Gonadotropins, and Markers of Bone Turnover in Older Men1
Authors: Taxel Pamela , Kennedy Dayna G. , Fall Pamela M. , Willard Alice K. , Clive Jonathan M. , Raisz Lawrence G. 
Published: January 2014

There is evidence that estrogen decreases bone turnover in men as well as women. We therefore hypothesized that older men would show increased bone resorption in response to inhibition of the aromatase enzyme, which converts androgens to estrogen.
Fifteen eugonadal men over 65 yr were treated for 9 weeks with 2.0 mg/day of anastrozole, an aromatase inhibitor. After 9 weeks of treatment, there were significant decreases in estradiol, estrone, and sex hormone-binding globulin levels by 29%, 73%, and 16%, respectively, and total testosterone increased significantly by 56%. Despite the limited decrease of estrogen and the increase in testosterone, C-telopeptide of type 1 collagen showed a progressive significant increase of 11%, 24%, and 33% (P for trend = 0.033) above baseline at 3, 6, and 9 weeks, respectively. N-telopeptide of type 1 collagen values were highly correlated with C-telopeptide of type 1 collagen, but the change in N-telopeptide of type 1 collagen was not statistically significant. Bone-specific alkaline phosphatase and N-terminal type I procollagen peptides showed significant decreases of 8% and 11% of baseline at 9 weeks. Osteocalcin decreased significantly by 30% at 18 weeks.
We conclude that aromatase inhibition can reduce estrogen levels in older men, but this effect is limited, perhaps because of feedback stimulation of testosterone production, and that endogenous estrogen derived from aromatization of testosterone plays a role in bone metabolism of older men by limiting the rate of bone resorption.
Cross-Sectional and Prospective Associations between Abdominal Adiposity and Proinsulin Concentration
Authors: Hanley Anthony J. G. , McKeown-Eyssen Gail , Harris Stewart B. , Hegele Robert A. , Wolever Thomas M. S. , Kwan Jeremy , Zinman Bernard 
Published: January 2014

The objective of this study was to investigate the associations of total and abdominal obesity with variation in proinsulin concentration in a Native Canadian population experiencing an epidemic of type 2 diabetes mellitus (DM).Between 1993 and 1995, 728 members of a Native Canadian community participated in a population-based survey to determine the prevalence and risk factors for type 2 DM. Samples for glucose, C-peptide, and proinsulin were drawn after an overnight fast, and a 75-g oral glucose tolerance test was administered. Type 2 DM and impaired glucose tolerance (IGT) were diagnosed using World Health Organization criteria. Height, weight, waist circumference, and percent body fat were measured. In 1998, 95 individuals who, at baseline, had IGT or normal glucose tolerance with an elevated 2-h glucose level (≥7.0 mm) participated in a follow-up evaluation using the same protocol.After adjustment for age, sex, C-peptide concentration, per cent body fat, and waist circumference, proinsulin was found to be significantly elevated in diabetic subjects, relative to subjects with both impaired and normal glucose tolerance (both P &lt; 0.0001); and the concentration in those with IGT was higher, compared with normals (P &lt; 0.0001). Among nondiabetic subjects, proinsulin showed significant univariate associations with percent body fat, body mass index, and waist circumference (r = 0.34, 0.45, 0.41, respectively, all P &lt; 0.0001). After adjustment for body fat and other covariates, waist circumference remained significantly associated with proinsulin concentration in nondiabetic subjects (r = 0.20, P &lt; 0.0001). In prospective analysis, adjusted for covariates (including baseline IGT and follow-up glucose tolerance status), baseline waist circumference was positively associated with both follow-up and change in proinsulin concentration (r = 0.27, P = 0.01; r = 0.24, P = 0.03, respectively).These data highlight the detrimental effects of abdominal obesity on β-cell function, and support the hypothesis that β-cell dysfunction occurs early in the natural history of glucose intolerance.
Glial-Derived Neurotropic Factor and RET Gene Expression in Normal Human Anterior Pituitary Cell Types and in Pituitary Tumors
Authors: Japón Miguel A. , Urbano Angel G. , Sáez Carmen , Segura Dolores I. , Cerro Alfonso Leal , Diéguez Carlos , Alvarez Clara V. 
Published: January 2014

Abstract
Glial-derived neurotropic factor (GDNF) signaling is mediated through a 2-component system consisting of the so-called GDNF receptor-α (GFRα1), which binds to GDNF. This complex activates the tyrosine kinase receptor RET. In this paper we demonstrate GDNF, GFRα1, and RET mRNA and protein expression in the human anterior pituitary gland. Double immunohistochemistry of anterior pituitary sections showed GDNF immunoreactivity in more than 95% of somatotrophs and to a lesser extent in corticotrophs (20%); it was almost absent in the remaining cell types. Also, although more than 95% of somatotrophs were stained for RET, no positive immunostaining could be detected in other cell types. Furthermore, we have looked for GDNF and RET in human pituitary adenomas of various hormonal phenotypes. Strong positive immunostaining was found for c-RET in all of the GH-secreting adenomas screened as well as in 50% of ACTH-producing adenomas. Positive immunostaining for GDNF was found in all of the GH-secreting adenomas and in 10% of the corticotropinomas. Lastly, we found strong positive immunostaining for GFRα1 in 90% of the somatotropinomas and 50% of the corticotropinomas as well as in 1 of 8 prolactinomas and 1 of 13 nonfunctioning adenomas. All of the remaining pituitary tumors screened were negative for RET, GDNF, and GFRα1.
This study indicates that GDNF may well be acting in the regulation of somatotroph cell growth and/or cell function in the normal human anterior pituitary gland. The expression of RET in all of the somatotropinomas and in 50% of the ACTH-producing tumors implies that GDNF and RET could be involved in the pathogenesis of pituitary tumors.
Identification of Amino Acids in the τ2-Region of the Mouse Glucocorticoid Receptor That Contribute to Hormone Binding and Transcriptional Activation
Authors: Milhon Jon , Lee Sunyoung , Kohli Kulwant , Chen Dagang , Hong Heng , Stallcup Michael R. 
Published: January 2014

AbstractThe τ2-region of steroid hormone receptors is a highly conserved region located at the extreme N-terminal end of the hormone-binding domain. A protein fragment encoding τ2 has been shown to function as an independent transcriptional activation domain; however, because this region is essential for hormone binding, it has been difficult to determine whether the τ2-region also contributes to the transactivation function of intact steroid receptors. In this study a series of amino acid substitutions were engineered at conserved positions in the τ2-region of the mouse glucocorticoid receptor (mGR, amino acids 533–562) to map specific amino acid residues that contribute to the hormone-binding function, transcriptional activation, or both. Substitution of alanine or glycine for some amino acids (mutations E546G, P547A, and D555A) reduced or eliminated hormone binding, but the transactivation function of the intact GR and/or the minimum τ2-fragment was unaffected for each of these mutants. Substitution of alanine for amino acid S561 reduced transactivation activity in the intact GR and the minimum τ2-fragment but had no effect on hormone binding. The single mutation L550A and the double amino acid substitution L541G+L542G affected both hormone binding and transactivation. The fact that the S561A and L550A substitutions each caused a loss of transactivation activity in the minimum τ2-fragment and the full-length GR indicated that the τ2-region does contribute to the overall transactivation function of the full-length GR. Overall, the N-terminal portion of the τ2-region (mGR 541–547) was primarily involved in hormone binding, whereas the C-terminal portion of theτ 2-region (mGR 548–561) was primarily involved in transactivation.
Stress-Induced Transcriptional Regulation in the Developing Rat Brain Involves Increased Cyclic Adenosine 3′,5′-Monophosphate-Regulatory Element Binding Activity
Authors: Hatalski Carolyn G. , Baram Tallie Z. 
Published: January 2014

Abstract
The cAMP-regulatory element (CRE) binding protein (CREB) functions as a trans-acting regulator of genes containing the CRE sequence in their promoter. These include a number of critical genes, such as CRF, involved in the hypothalamic response to stressful stimuli in the adult. The ability of the developing rat (during the first 2 postnatal weeks) to mount the full complement of this stress response has been questioned. We have previously demonstrated the stress-induced up-regulation of the transcription of hypothalamic CRF during the second postnatal week in the rat. The focus of the current study was to explore the mechanism of transcriptional regulation in response to stress through the physiological induction of transcriptional trans-activators that bind to the CRE in the developing rat brain. CRE-binding activity was detected via gel shift analysis in extracts from both the hypothalamus and the cerebral cortex of the developing rat. CREB was identified in these extracts by Western blot analysis and was shown to be the major contributor to the CRE-binding activity by gel shift analysis with two specific antibodies directed against CREB. After acute hypothermic stress, the abundance of CRE-binding activity (but not of total immunoreactive CREB), increased in hypothalamic extracts. This enhanced CRE-binding activity was blocked by an antiserum directed against CREB and was accompanied by an apparent increase in CREB phosphorylation. These results indicate that posttranslational enhancement of CRE-binding activity is likely to constitute an important mechanism for up-regulation of genes possessing the CRE sequence in the developing rat hypothalamus by adverse external signals.