bluuebunny/crossref_metadata_2025 huggingface dataset:
The Metabolic Significance of Leptin in Humans: Gender-Based Differences in Relationship to Adiposity, Insulin Sensitivity, and Energy Expenditure*
Authors: Kennedy Adele , Gettys Thomas W. , Watson Patricia , Wallace Penny , Ganaway Elizabeth , Pan Qin , Garvey W. Timothy
Published: January 2014

Leptin is an adipocyte-derived hormone that interacts with a putative receptor(s) in the hypothalamus to regulate body weight. The relationship of leptin to metabolic abnormalities associated with obesity together with hormonal and substrate regulation of leptin have not been extensively studied. Therefore, 116 subjects (62 men and 54 women) with a wide range of body weight [body mass index (BMI), 17–54 kg/m2] were characterized on a metabolic ward with regard to body composition, glucose intolerance, insulin sensitivity, energy expenditure, substrate utilization, and blood pressure. Eighty-five of the subjects had normal glucose tolerance (50 men and 35 women), and 31 had noninsulin-dependent diabetes mellitus (12 men and 19 women). In both men and women, fasting leptin levels were highly correlated with BMI (r = 0.87 and r = 0.88, respectively) and percent body fat (r = 0.82 and r = 0.88, respectively; all P < 0.0001). However, men exhibited lower leptin levels at any given measure of obesity. Compared with those in men, leptin levels rose 3.4-fold more rapidly as a function of BMI in women[ leptin = 1.815 (BMI) − 31.103 in women; leptin = 0.534 (BMI) − 8.437 in men] and 3.2 times more rapidly as a function of body fat [leptin = 1.293 (% body fat) − 24.817 in women; leptin = 0.402 (% body fat) − 3.087 in men]. Hyperleptinemia was associated with insulin resistance (r = −0.57; P < 0.0001) and high waist to hip ratio (r = 0.75; P < 0.0001) only in men. On the other hand, during the hyperinsulinemic euglycemic clamp studies, hyperinsulinemia acutely increased leptin concentrations (20%) only in women. There was no correlation noted between fasting leptin levels and either resting energy expenditure or insulin-induced thermogenesis in men or women (P = NS). In stepwise and multiple regression models with leptin as the dependent variable, noninsulin-dependent diabetes mellitus did not enter the equations at a statistically significant level.

The data indicate that there are important gender-based differences in the regulation and action of leptin in humans. Serum leptin levels increase with progressive obesity in both men and women. However, for any given measure of obesity, leptin levels are higher in women than in men, consistent with a state of relative leptin resistance. These findings have important implications regarding differences in body composition in men and women. The observation that serum leptin is not related to energy expenditure rates suggests that leptin regulates body fat predominantly by altering eating behavior rather than calorigenesis.
Dual Hormonal Replacement Therapy with Insulin and Recombinant Human Insulin-Like Growth Factor (IGF)-I in Insulin-Dependent Diabetes Mellitus: Effects on the Growth Hormone/IGF/IGF-Binding Protein System*
Authors: Thrailkill Kathryn , Quattrin Teresa , Baker Lester , Litton Jean , Dwigun Karen , Rearson Melissa , Poppenheimer Mary , Kotlovker Debbie , Giltinan David , Gesundheit Neil , Martha Paul
Published: January 2014

Patients with insulin-dependent diabetes mellitus (IDDM) exhibit abnormalities in the GH/insulin-like growth factor (IGF) axis, including GH hypersecretion, low serum IGF-I and IGF-binding protein-3 (IGFBP-3) levels, and elevated IGFBP-1 levels. We recently demonstrated that in IDDM, dual hormonal replacement therapy with insulin plus recombinant human IGF-I (rhIGF-I) improves glycemic control better than insulin alone. To determine whether the addition of rhIGF-I therapy to insulin therapy also corrects GH/IGF/IGFBP abnormalities, we examined the effects of chronic combined rhIGF-I/insulin therapy on key components of the somatotropin axis. Forty-three pediatric IDDM patients were randomly assigned to groups receiving daily, fasting subcutaneous injections of placebo or rhIGF-I (80 μg•kg•day) for 28 days, while continuing to receive split-mix insulin therapy and intensive outpatient management. rhIGF-I therapy corrected IGF-I deficiency, suppressed IGFBP-1 levels (P < 0.01), and induced a trend toward lower circulating GH levels throughout the study. rhIGF-I therapy also induced an approximate 50% decrease in IGF-II levels (P < 0.001) and an approximate 70% increase in IGFBP-2 levels (P < 0.05). Serum IGFBP-3 levels, normal before treatment, remained normal during rhIGF-I administration. All effects were apparent during the first week of rhIGF-I therapy and persisted throughout treatment. Because improvements in the GH/IGF axis abnormalities and in glycemic control were greater in subjects receiving combined rhIGF-I and insulin, these data strongly support the concept that dual hormonal replacement in IDDM may offer distinct therapeutic advantages over insulin monotherapy.
Short-Term Effects of Growth Hormone and Insulin-Like Growth Factor I on Cancellous Bone in Rhesus Macaque Monkeys*
Authors: Sass D. A. , Jerome C. P. , Bowman A. R. , Bennett-Cain A. , Ginn T. A. , LeRoith D. , Epstein S.
Published: January 2014

The purpose of our study was to determine the effects of GH and insulin-like growth factor I (IGF-I) administration singly and in combination on vertebral, tibial, and femoral bone in aged female monkeys as well as the various treatment effects on serum hormone levels and osteocalcin gene expression. Twenty-one ovulating female monkeys (rhesus macaque), aged 16–20 yr (5–6 kg), were divided into four groups to receive the following treatment for 7 weeks via Alzet pumps inserted sc: A, eluant (control group); B, recombinant human IGF-I (rhIGF-I; 120 μg/kg·day); C) rhGH (100 μg/kg·day); D, combination of rhIGF-I (120 μg/kg·day) and rhGH (100μ g/kg·day). Serum was assayed serially for glucose, IGF-I, GH, and IGF-binding protein-3 levels. All groups received double labeling with calcein. On the day of death, the primates’ second lumbar vertebrae, tibiae, and femora were carefully dissected, fixed in 70% ethanol, and subjected to histomorphometric analysis. Ribonucleic acid was extracted from contralateral tibiae for the purpose of osteocalcin gene expression analysis. Serum glucose was unaffected by treatment. Serum GH was significantly elevated in groups C and D, whereas serum IGF-I and IGFBP-3 were only significantly increased in group D. Histomorphometric analysis showed no significant differences or trends for bone volume in any treatment group. Bone formation rate, surface and/or bone volume referent were significantly higher in both groups treated with GH (C and D) in tibia and femur, with a similar trend in vertebrae. The increase in bone formation rate was due mainly to a significant increase in mineral apposition rate, but there was also an increase in tibial mineralizing surface by GH by factorial analysis (P < 0.05). There were significant treatment effects on osteoid surface and osteoclastic surface in femur in the combination treatment group vs. the controls. Osteocalcin gene expression analysis supported an enhanced expression in both groups treated with GH. These findings are consistent with a short term effect of GH to increase bone remodeling and predominantly osteoblastic activity in the appendicular skeleton. In contrast, other than an isolated increase in osteoclastic surface in femoral bone, IGF-I, when administered alone, was unable to significantly influence bone formation or resorption activity in this short term study.
An Autosomal Dominant Form of Familial Persistent Hyperinsulinemic Hypoglycemia of Infancy, Not Linked to the Sulfonylurea Receptor Locus*
Authors: Kukuvitis Asterios , Deal Cheri , Arbour Laura , Polychronakos Constantin
Published: January 2014

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI), a rare disorder due to defective negative feedback regulation of insulin secretion by low glucose levels, is often familial. Most cases are recessively inherited, and mutations of the sulfonylurea receptor gene (SUR) or the closely linked KIR6.2 gene have been found in several families. Both of these genes encode components of the potassium channels responsible for glucose-regulated insulin release. However, in some families recessive PHHI is not linked to the SUR-KIR6.2 locus, suggesting genetic heterogeneity. We report here a French Canadian kindred with hypoglycemia in five first cousins. All five patients had documented hypoglycemia, and all responded well to diazoxide. In two, inappropriately elevated insulin levels during hypoglycemia were documented. This familial clustering strongly suggests the existence of an autosomal dominant form of PHHI. By preliminary linkage analysis, we tested the possibility of a dominant negative SUR or KIR6.2 mutant. The insulin (INS) and glucokinase (GCK) genes were also tested as additional candidates. Microsatellite markers closely linked to each gene were used, and large negative Lod scores were obtained at the known recombination fractions between all three genes studied and the corresponding marker. We conclude that mutation of a gene other than SUR or KIR6.2 is responsible for the dominant PHHI in this family, and this gene cannot be INS or GCK. We propose that a genome-wide search for this gene is important for elucidating this rare disorder and, more importantly, for determining its potential impact on understanding noninsulin-dependent diabetes mellitus and on the effort to develop bioengineered β-cells for transplantation.
Expression of the Apoptosis-Suppressing Gene BCL-2 in Pheochromocytoma is Associated with the Expression of C-MYC
Authors: Wang Da-Gong , Johnston Colin F. , Marley John J. , Phenix Kerry V. , Atkinson A. Brew , Russell Colin F. J. , Buchanan Keith D.
Published: January 2014

It has become increasingly clear that deregulation of programmed cell death is a critical component in multistep tumorigenesis. Previous studies have demonstrated a high frequency of Bcl-2 expression in tumors arising from cells derived from the neural crest and in tumor cell lines of neural origin. The present investigation was undertaken to determine whether similar molecular events occur in human pheochromocytoma. With the aim of determining the potential role of apoptosis in the pathogenesis of this tumor, we assessed proto-oncogene Bcl-2 and c-myc protein products as well as Bcl-2 messenger RNA levels in a collection of such tumors. Western blot analysis revealed that such tumors expressed the 26 kDa Bcl-2 (5 of 8 cases) and the 64 kDa c-Myc (7 of 8 cases) proteins. Northern blot analysis detected the Bcl-2 transcripts in 6 of 8 tumors. Immunoperoxidase staining, using a monoclonal anti-Bcl-2 antibody, was positive in 18 (82%), including 5 malignant tumors, of the 22 specimens examined. This Bcl-2 immunoreactivity was seen in 14 of 18 (78%) sporadic tumors, including 2 that were extra-adrenal, and all familial tumors. Of the 22 tumor samples examined for c-Myc protein, 20 (91%) tumors were positive. Our results suggest that deregulation of programmed cell death may be a critical component in the multistep tumorigenesis of human pheochromocytoma. The genetic complementation of simultaneously deregulated Bcl-2 and c-myc may be implicated in this process.
Vitamin D Receptor Polymorphisms Correlate to Parathyroid Cell Function in Primary Hyperparathyroidism1
Authors: Carling Tobias , Ridefelt Peter , Hellman Per , Rastad Jonas , Åkerström Göran
Published: January 2014

Calcitriol acts via its receptor (VDR) and inhibits PTH secretion and parathyroid cell proliferation. Increased prevalence of the polymorphic VDR alleles b, a, and T has been demonstrated in sporadic primary hyperparathyroidism. Sixty-two patients with primary hyperparathyroidism due to parathyroid adenoma (mean age, 69.5 ± 1.4 yr) were genotyped for these VDR polymorphisms. Dispersed cells of the adenomas were exposed to increasing concentrations of extracellular Ca2+ and analyzed for PTH release and cytoplasmic Ca2+ concentrations. Ca2+-mediated PTH inhibition exhibited higher ED50 and less suppression in the cells of patients who were homozygous for the b, a, and T alleles (P < 0.05–0.10). When analyzing haplotypes, the patients with baT demonstrated a ED50 of 1.81 ± 0.15 vs. 1.29 ± 0.10 for BAt (P < 0.05). As VDR alleles were unrelated to parathyroid intracellular Ca2+, influences of polymorphic VDR alleles on PTH secretion seem to involve mechanisms other than the Ca2+-sensing protein of the parathyroid cell surface.
Immunoglobulin Gκ Antithyroid Peroxidase Antibodies in Hashimoto’s Thyroiditis: Epitope-Mapping Analysis1
Authors: Czarnocka Barbara , Janota-Bzowski Marek , McIntosh Richard S. , Asghar M. Suhail , Watson Philip F. , Kemp E. Helen , Carayon Pierre , Weetman Anthony P.
Published: January 2014

Patients with autoimmune thyroid disease frequently have high affinity antibodies to thyroid peroxidase (TPO), although the role they play in disease pathogenesis is not known. We have previously prepared 37 monoclonal anti-TPO IgGκ Fab fragments from two patients with Hashimoto’s thyroiditis and demonstrated the similarity of these Fab sequences to those published previously, mainly derived from patients with Graves’ disease. In this paper, we describe epitope mapping of these Fabs using a previously characterized panel of murine monoclonal antibody (mAb) and show that the Fabs bind to two neighboring epitopes on native TPO. Although the epitope-mapping method differs from that used to characterize previously published TPO-reactive Fab sequences, it indicates a similarly restricted response to neighboring epitopes in both Graves’ disease and Hashimoto’s thyroiditis. The epitope mapping included mAb 47, which binds to a linear TPO peptide of known sequence in addition to native TPO. Although TPO-reactive Fab did not inhibit the binding of mAb 47, mAb 47 did inhibit the binding of Fab, indicating the likely site of the immunodominant region on native TPO. These results confirm the restricted nature of TPO antibody and further delineate the immunodominant region of native TPO as defined by the mAb.
Prevention of Early Postmenopausal Bone Loss with Cyclical Etidronate Therapy (A Double-Blind, Placebo-Controlled Study and 1-Year Follow-Up)*
Authors: Meunier P. J. , Confavreux E. , Tupinon I. , Hardouin C. , Delmas P. D. , Balena R.
Published: January 2014

The objective of the study was to evaluate the effects of cyclical therapy with etidronate and calcium on spinal and femoral bone loss in the early post menopausal period. Fifty-four women, 53 ± 2.8 yr old (mean ± sd) and 2.3 ± 1.3 yr post menopause received oral doses of either 400 mg/day etidronate for 2 weeks followed by 500 mg/day elemental calcium for 11 weeks, or placebo for 14 days followed by calcium for 11 weeks, repeated over a total of 24 months. A statistically significant increase in spinal bone mineral density (BMD) was observed after 6 months in the etidronate group. At 2 yr, the mean treatment differences in spinal and femoral neck BMD were+ 2.93% (P < 0.02) and 2.02% (P < 0.03), respectively. Serum osteocalcin and urinary crossLaps/creatinine excretion were decreased signficantly by etidronate. Etidronate was well tolerated with a safety profile similar to that of placebo.

Thirty-seven women participated in a 1-yr open-label follow-up study. Twelve months after treatment withdrawal, spinal BMD in the former etidronate group decreased by 1.43% and serum osteocalcin and urinary crossLaps returned to pretreatment values.

In conclusion, cyclical etidronate is an effective therapy for the prevention of both trabecular and cortical bone loss in the early menopause and has a good safety profile.
Low Thyrotropin Levels Are Not Associated with Bone Loss in Older Women: A Prospective Study*
Authors: Bauer Douglas C. , Nevitt Michael C. , Ettinger Bruce , Stone Katie
Published: January 2014

The relationship between excess thyroid hormone and bone loss is controversial. To determine whether low TSH levels, indicating excessive thyroid hormone, are associated with low bone mass or accelerated bone loss in older women, we performed a prospective cohort study of 458 women over age 65 yr participating in the multicenter Study of Osteoporotic Fractures.

Three hundred and twenty-three women were randomly selected from the entire cohort of 9704; an additional 135 randomly selected thyroid hormone users were studied. Medical history, medication use, and calcaneal bone mineral density (BMD) were assessed at the baseline visit. Serum was collected and stored at −190 C. Hip and spine BMD were measured approximately 2 yr later, and follow-up calcaneal and hip BMD measurements were obtained after mean follow-up periods of 5.7 and 3.5 yr, respectively. TSH levels were determined in baseline serum samples using a third generation chemiluminescent assay.

After adjustment for age, weight, previous hyperthyroidism, and use of estrogen, bone loss over 4–6 yr was similar in women with low, normal, or high TSH. For example, femoral neck bone loss was −0.3%/yr (95% confidence interval, −0.8%, 0.3%) among women with low TSH (≤0.1 mU/L) and −0.5%/yr (95% confidence interval, −0.7%, −0.3%) in those with normal TSH (0.1–5.5 mU/L). There were no statistically significant differences in baseline bone mass of the calcaneus, spine, or femoral neck or trochanteric hip subregions. Baseline total hip BMD was 6% lower (P = 0.01) in women with low TSH. Similar results were obtained in analyses confined to women not taking estrogens.

We found no consistent evidence that low TSH, a sensitive biochemical marker of excess thyroid hormone, was associated with low BMD or accelerated bone loss in older ambulatory women.
Effect of Therapy with Recombinant Human Growth Hormone on Insulin-Like Growth Factor System Components and Serum Levels of Biochemical Markers of Bone Formation in Children After Severe Burn Injury1
Authors: Klein Gordon L. , Wolf Steven E. , Langman Craig B. , Rosen Clifford J. , Mohan Subburaman , Keenan Bruce S. , Matin Sina , Steffen Christopher , Nicolai Marc , Sailer Dawn E. , Herndon David N.
Published: January 2014

Burn injury in children is associated with low bone formation and long-term bone loss. Because recombinant human GH (rHGH) may accelerate burn wound healing, and because rHGH increases bone formation and density in GH-deficient patients, we studied the short-term effects of rHGH on bone formation, reflected by osteocalcin and type I procollagen propeptide levels in a randomized, double-blind, placebo-controlled study. Nineteen patients were enrolled and received either rHGH (0.2 mg/kg·day) or an equal volume of saline. Mean burn size and age were not different between the groups, and test substances were given from admission to time of wound healing (mean: 43 ± 22 days). At wound healing, serum levels of insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 in the rHGH group rose to mean values of 229% and 187% of the respective means of the placebo group (P < 0.025). Serum osteocalcin concentrations remained below normal in both groups, and type I procollagen propeptide levels achieved a low normal level. IGFBP-4 levels were twice that of normal on admission and doubled further at wound healing; IGFBP-5 levels were low on admission but rose to normal at wound healing. We conclude that large doses of rHGH were ineffective in improving disordered bone formation despite increasing serum IGF-1 and IGFBP-3. The rHGH-independent rise in serum levels of the inhibitory binding protein IGFBP-4 suggests a mechanism by which improved bone formation is prevented despite successful elevation of IGF-1 and IGFBP-3 in the burned child.
Outcomes of Therapy for Cushing’s Disease due to Adrenocorticotropin-Secreting Pituitary Macroadenomas1
Authors: Blevins Lewis S. , Christy James H. , Khajavi Masheed , Tindall George T.
Published: January 2014

We reviewed our experience with 21 patients who had Cushing’s disease due to ACTH-secreting macroadenomas to clarify the natural history of this disease. All patients had typical clinical and biochemical features of ACTH-dependent hypercortisolism. Their mean maximal tumor diameter was 1.6 ± 0.1 cm, and the range was 1.0–2.7 cm. Six patients had cavernous sinus invasion, three had invasion of the floor of their sella, and nine had suprasellar extension. The observed remission rate was significantly lower in macroadenoma patients than in microadenoma patients (67% vs. 91%; χ2 = 5.7; P < 0.02). Cavernous sinus invasion (odds ratio, 35; 95% confidence interval, 2.6–475; P < 0.008) and presence of a maximum tumor diameter 2.0 cm or more (odds ratio, 12.9; 95% confidence interval, 1.4–124; P< 0.02) emerged as the only predictors of residual disease after surgery. The observed recurrence rate was significantly higher in macroadenoma patients than in microadenoma patients (36% vs. 12%; χ2 = 4.2; P< 0.05). Macroadenoma patients tended to suffer from recurrences earlier than did microadenoma patients (16 vs. 49 months). Stepwise multiple logistic regression did not identify any predictors of disease recurrence in macroadenoma patients. Eight macroadenoma patients underwent a total of nine repeat surgical procedures, but none of these resulted in clinical remissions. Only four of seven (57%) patients followed for a sufficient period of time achieved normal urinary free cortisol levels after conventional radiotherapy. Three (75%) of these four patients had re-recurrent hypercortisolism after brief periods of eucortisolism. Pharmacological agents and adrenalectomy were effective in the management of hypercortisolism in patients with residual and recurrent disease. Our results indicate that ACTH-secreting macroadenomas are more refractory to conventional treatments than are ACTH-secreting microadenomas.
A PHEX Gene Mutation Is Responsible for Adult-Onset Vitamin D-Resistant Hypophosphatemic Osteomalacia: Evidence That the Disorder Is Not a Distinct Entity from X-Linked Hypophosphatemic Rickets1
Authors: Econs Michael J. , Friedman Nancy E. , Rowe Peter S. N. , Speer Marcy C. , Francis Fiona , Strom Tim M. , Oudet Claudine , Smith John A. , Ninomiya James T. , Lee Benjamin E. , Bergen Heather
Published: January 2014

Previous investigators described a kindred with an X-linked dominant form of phosphate wasting in which affected children did not have radiographic evidence of rickets, whereas older individuals were progressively disabled by severe bowing. They proposed that this kindred suffered from a distinct disorder that they referred to as adult-onset vitamin D-resistant hypophosphatemic osteomalacia (AVDRR). We recently identified a gene, PHEX, that is responsible for the disorder X-linked hypophosphatemic rickets. To determine whether AVDRR is a distinct form of phosphate wasting, we searched for PHEX mutations in affected members of the original AVDRR kindred. We found that affected individuals have a missense mutation in PHEX exon 16 that results in an amino acid change from leucine to proline in residue 555. Clinical evaluation of individuals from this family indicates that some of these individuals display classic features of X-linked hypophosphatemic rickets, and we were unable to verify progressive bowing in adults. In light of the variability in the clinical spectrum of X-linked hypophosphatemic rickets and the presence of a PHEX mutation in affected members of this kindred, we conclude that there is only one form of X-linked dominant phosphate wasting.
A Randomized, Cross-Over Trial of Once-Daily Versus Twice-Daily Parathyroid Hormone 1–34 in Treatment of Hypoparathyroidism
Authors: Winer Karen K. , Yanovski Jack A. , Sarani Babak , Cutler Jr. Gordon B.
Published: January 2014

Once-daily sc injection of PTH 1–34 can normalize mean serum and urine calcium levels in patients with hypoparathyroidism; however, once-daily PTH has diminishing effects on serum calcium after 12 h, such that serum calcium levels fall below the normal range in some patients. Once-daily PTH also causes a marked increase in bone turnover, with persistent increases in markers of bone formation and resorption. To test the hypothesis that a twice-daily PTH regimen can produce more physiological control than a once-daily regimen, we performed a randomized cross-over trial, lasting 28 weeks, in 17 adult subjects with hypoparathyroidism. Each 14-week study arm was divided into a 2-week inpatient dose-adjustment phase and a 12-week outpatient phase. The PTH dose (given sc once daily at 0900 h or twice daily with one dose at 0900 h and the other at 2100 h) was adjusted to maintain both serum and urine calcium within, or close to, the normal range.

During the second half of the day (12–24 h), twice-daily PTH increased serum calcium and magnesium levels more effectively than once-daily PTH. In patients with calcium receptor mutations (CaR), once-daily PTH normalized urine calcium, provided that serum calcium was maintained at levels below normal range. However, twice-daily PTH treatment produced higher mean serum calcium in patients with CaR with no significant rise in urine calcium excretion, and with no significant differences in either serum or urine calcium levels between CaR and patients with acquired or idiopathic hypoparathyroidism. Thus, treatment with twice-daily PTH is the better regimen for patients with CaR to overcome their tendency to hypercalciuria while producing near-normal levels of serum calcium. The total daily PTH dose was markedly reduced with the twice-daily regimen (twice daily 46 ± 52 vs. once daily 97 ± 60 μg/day, P < 0.001). We conclude that a twice-daily PTH regimen provides effective treatment of hypoparathyroidism and reduces the variation in serum calcium levels at a lower total daily PTH dose.
Systematic Mutation Screening of the Pro-Opiomelanocortin Gene: Identification of Several Genetic Variants Including Three Different Insertions, One Nonsense and Two Missense Point Mutations in Probands of Different Weight Extremes
Authors: Hinney A. , Becker I. , Heibült O. , Nottebom K. , Schmidt A. , Ziegler A. , Mayer H. , Siegfried W. , Blum W. F. , Remschmidt H. , Hebebrand J.
Published: January 2014

Pro-opiomelanocortin (POMC) is the precursor of melanocortins (adrenocorticotropin: ACTH, β-endorphin, β-lipotropin; β-LPH corticotropin like intermediate peptide, α-, β- andγ -melanocyte-stimulating hormone: α-, β- and γ-MSH) some of which act in the brain to reduce food intake and are potential mediators of leptin action. Recently, three different mutations in the POMC gene (POMC) were identified in two unrelated children that lead to early-onset extreme obesity, adrenal insufficiency, and red hair pigmentation (1). In the present study we systematically screened the coding region of POMC in 96 extremely obese children and adolescents, 60 healthy underweight individuals and 46 patients with anorexia nervosa (AN) and identified several variants. a) A 9 and an 18 base pair insertion (9bp and 18bp: AGC AGC GGC and AGC AGC GGC AGC AGC GGC, respectively, between codon 73 and 74; 1,2). These in-frame variants lead to the insertion of three or six amino acids (Ser-Ser-Gly; Ser-Ser-Gly-Ser-Ser-Gly) carboxy-terminal to γ-MSH. Frequencies of the 9bp insertion allele varied between 3 and 5% among the different study groups (Pearson’s χ2 P>0.5). b) Both an out-of-frame 6 bp insertion (within codon 176: GGG CCC) leading to the insertion of two amino acids (Arg-Ala) and a premature stop-codon (G-7316-T: Glu-180-Stop) within the γ-LPH sequence were maternally inherited in an obese female proband. This proband inherited another missense mutation from her father (Glu-188-Gly). c) A missense mutation (G-7016-A; Asp-80-Asn) was observed in a single patient with AN who also harboured the 9bp insertion on a paternally derived haplotype. d) The allelic co-occurence of two silent mutations (C-6982-T and C-7285-T) was detected in two obese subjects. e) Two further silent mutations (C-3832-T; C-7111-G) were detected in an underweight and an obese subject, respectively. We conclude that the POMC gene harbors several different polymorphisms and mutations, none of which can readily be associated with the phenotypes under study.
Na+/I− Symporter Distribution in Human Thyroid Tissues: An Immunohistochemical Study1
Authors: Caillou Bernard , Troalen Frédéric , Baudin Eric , Talbot Monique , Filetti Sébastiano , Schlumberger Martin , Bidart Jean-Michel
Published: January 2014

Antipeptide antibodies raised against the carboxyl-terminal region of the human sodium/iodide (Na+/I−) symporter (hNIS) were used to investigate by immunohistochemistry the presence and distribution of the hNIS protein in normal thyroid tissues, in some pathological nonneoplastic thyroid tissues, and in different histotypes of thyroid neoplasms. In normal thyroid tissue, staining of hNIS protein was heterogeneous and limited to a minority of follicular cells that were in close contact with capillary vessels. In positive cells, immunostaining was limited to the basolateral membrane. In contrast, in Graves’ disease the majority of follicular cells expressed the hNIS protein. In autoimmune thyroiditis, the number of hNIS-positive cells, was similar to that found in normal tissue. These positive cells were found essentially close to lymphocytic infiltrates. This observation supports the concept of hNIS as an autoantigen. In diffuse nodular hyperplasia, hNIS staining was heterogeneous, but the number of hNIS-positive cells exceeded that found in normal tissue. In well differentiated follicular or papillary carcinoma, the number of hNIS-positive cells was significantly lower than in normal tissue. In poorly differentiated follicular carcinoma, the number of hNIS-positive cells was less than that found in well differentiated carcinoma, or there were no positive cells. Interestingly, in all of these thyroid tissues, the number of follicular cells exhibiting TSH receptor (TSHR) immunoreactivity was greater than the number of hNIS-positive cells. As hNIS expression appears to be related to TSHR stimulation, the decreased number of TSHR-positive cells in cancers may contribute to the reduced capacity of neoplastic cells to concentrate iodide. In one patient with a follicular cancer with an absence of hNIS immunostaining, the total body 131I scan showed no uptake in metastatic tissue. In three cancers with positive hNIS cells, the 131I scan showed uptake in lymph node metastases. This suggests that immunodetection of hNIS could predict radioiodine uptake in thyroid cancers.
Ineffective Cardiorespiratory Function in Hyperthyroidism1
Authors: Kahaly George J. , Nieswandt Jana , Wagner Stefan , Schlegel Jens , Mohr-Kahaly Susanne , Hommel Gerhard
Published: January 2014

Dyspnea on exertion is a common complaint in hyperthyroidism, and this thyroid dysfunction has been implicated as a primary cause of impaired effort tolerance. Using spirometry and spiroergometry, 42 patients with untreated hyperthyroidism were examined, and the condition was controlled 7 days later under propranolol monotherapy, as well as after 6 months in euthyroidism.

While hyperthyroid, reduced forced vital capacity and tidal volume at the anaerobic threshold (AT) were observed in comparison to euthyroidism. Decreased oxygen (O2) pulse at AT (7 ± 0.4 vs. 9.1 ± 0.4 mL/beat, P = 0.0012) and at maximal exercise was noted in hyperthyroidism and was enhanced under propranolol (8.9 ± 0.4 mL/beat, P = 0.0001). During exercise, the increment of minute ventilation (16.1 ± 0.7 vs. 20.2 ± 1.0 L/min, P = 0.0015), O2 uptake (9 ± 0.5 vs. 11.4 ± 0.5 mL/min/kg, P = 0.0022), O2 pulse (4.0 ± 0.3 vs. 5.6 ± 0.3 mL/beat, P = 0.0001), and heart rate (53 ± 2 vs. 65 ± 3 beat/min, P = 0.0004) was markedly lower in hyper- vs. euthyroidism. Work rate at AT and at maximum was reduced in hyper- vs. euthyroidism (107.4 ± 3 vs. 141.1 ± 4 watt, P= 0.0001). Negative correlations between free T3 and O2 pulse at AT (r = −0.59, P = 0.0005), delta O2 uptake (r = −0.54, P = 0.0007), delta minute ventilation (r = −0.48, P = 0.0007), and maximal work rate (r = −0.62, P = 0.0001) were noted.

In hyperthyroidism, analysis of respiratory gas exchange showed low efficiency of cardiopulmonary function, respiratory muscle weakness, and impaired exercise capacity, which were reversible in euthyroidism.
Growth Hormone Secretagogue Receptor Expression in Human Pituitary Tumors1
Authors: Skinner Monica M. , Nass Ralf , Lopes Beatriz , Laws Edward R. , Thorner Michael O.
Published: January 2014

The GH secretagogue (GHS) receptor (GHS-R) has been characterized and cloned. It is a member of a family of seven transmembrane receptors and is closely related to the neurotensin and TRH receptors. To determine the expression of this receptor in normal anterior pituitary and in 24 human pituitary adenomas, we analyzed GHS-R messenger ribonucleic acid (mRNA) using a RT-PCR assay. We found that normal human pituitary was positive for the GHS-R signal. In addition, all GH-secreting adenomas and the one TSH-secreting adenoma demonstrated the presence of GHS-R mRNA. Three of four ACTH-secreting tumors and three of nine gonadotroph adenomas were also positive for the GHS-R mRNA. To determine the amounts of GHS-R mRNA in normal pituitary and in representative tumors, semiquantitative competitive PCR was performed. We determined that normal pituitary had approximately 750 molecules/L GHS-R mRNA. The acromegalic tumor had approximately 1.5 × 105 molecules/L, and the TSH-secreting tumor had approximately 7.5 × 103 molecules/L. Other tumor types contained considerably less, with the ACTH-secreting and gonadotroph tumors expressing 7.5 × 102 and 3 × 102 GHS-R mRNA molecules/L, respectively. These results suggest that GH- and TSH-producing adenomas express GHS-R mRNA at levels 200 and 10 times higher, respectively, than the normal pituitary, and that this receptor expression may be involved in the pathogenesis and growth of these pituitary adenomas.
The Effect of Gonadotropin-Releasing Hormone Agonist on Type I Collagen C-Telopeptide and N-Telopeptide: the Predictive Value of Biochemical Markers of Bone Turnover
Authors: Amama Ernest A. , Taga Michiyoshi , Minaguchi Hiroshi
Published: January 2014

To evaluate the clinical utility of recently developed biochemical markers in the assessment of bone metabolism during GnRH agonist (GnRHa) treatment, we compared five bone resorption markers[ C-telopeptide (CTX) and N-telopeptide (NTX) of type I collagen, hydroxyproline (Hpr), pyridinoline (Pyr), and deoxypyridinoline (Dpyr)] and two bone formation markers [total alkaline phosphatase (Alp) and osteocalcin (OC)]. Sixty-eight normally menstruating women were injected with a long-acting GnRHa once a month for 24 weeks for the treatment of endometriosis or leiomyoma.

The mean percentage bone loss at the lumbar spine was 3.79% at the end of treatment. Although levels of all markers increased significantly as the treatment progressed, CTX and NTX exhibited the highest correlation coefficients between bone loss at 24 weeks and the seven markers measured at 0, 4, 12, 16, and 24 weeks of treatment. Serum estradiol levels were similarly suppressed during the treatment in both fast losers (whose bone loss was more than the mean) and slow losers (whose bone loss was less than the mean). However, significantly higher z-scores of bone resorption markers, but not of bone formation markers, were observed in the fast losers at 24 weeks of treatment, suggesting a more accelerated bone resorption in this group. Whereas the three highest z-scores at 24 weeks of treatment were CTX, NTX, and Dpyr (in that order), the highest z-score (P < 0.05) was observed for CTX in the fast losers. The subjects in the highest quartile of CTX, the highest, and second highest quartiles of NTX at 24 weeks of treatment experienced 2.1, 2.2, and 1.7 times more bone loss (P < 0.001), respectively, than those in the lowest quartiles. Furthermore, the subjects in the highest quartile of both CTX and NTX experienced 3.6 times more bone loss (P < 0.001) than those in the lowest quartile of both markers. These results indicate that both CTX and NTX are useful and sensitive markers for bone resorption in a hypoestrogenic state induced by GnRHa.
Iodine Intake and the Pattern of Thyroid Disorders: A Comparative Epidemiological Study of Thyroid Abnormalities in the Elderly in Iceland and in Jutland, Denmark
Authors: Laurberg Peter , Pedersen Klaus M. , Hreidarsson Astradur , Sigfusson Nikulas , Iversen Eigil , Knudsen Preben R.
Published: January 2014

Thyroid abnormalities are common in all populations, but it is difficult to compare results of epidemiological studies, because different methods have been used for evaluation. We studied the importance of the population iodine intake level for the prevalence rate of various thyroid abnormalities in elderly subjects.

Random samples of elderly subjects (68 yr) were selected from the central person registers in Jutland, Denmark, with low (n = 423) and, in Iceland, with longstanding relatively high (n = 100) iodine intake.

Females from Jutland had a high prevalence of goiter or previous goiter surgery (12.2%), compared with males from Jutland (3.2%) and females (1.9%) and males (2.2%) from Iceland. Abnormal thyroid function was very common in both areas, with serum TSH outside the reference range in 13.5% of subjects from Jutland and 19% of those from Iceland. In Jutland, it was mainly thyroid hyperfunction (9.7% had low, 3.8% had high serum TSH), whereas in Iceland, it was impaired thyroid function (1% had low, 18% had high serum TSH). All subjects with serum TSH more than 10 mU/L had autoantibodies in serum, but antibodies were, in general, more common in Jutland than in Iceland.

Thus, thyroid abnormalities in populations with low iodine intake and those with high iodine intake develop in opposite directions: goiter and thyroid hyperfunction when iodine intake is relatively low, and impaired thyroid function when iodine intake is relatively high. Probably, mild iodine deficiency partly protects against autoimmune thyroid disease. Thyroid autoantibodies may be markers of an autoimmune process in the thyroid or secondary to the development of goiter.
Identification and Characterization of Functional Nongenomic Progesterone Receptors on Human Sperm Membrane1
Authors: Luconi Michaela , Bonaccorsi Lorella , Maggi Mario , Pecchioli Paola , Krausz Csilla , Forti Gianni , Baldi Elisabetta
Published: January 2014

The presence of functional nongenomic progesterone (P) receptors in human spermatozoa has been investigated by equilibrium binding studies in intact spermatozoa, ligand blot and Western blot analysis of sperm lysates, as well as determination of the effects of the steroid on sperm intracellular Ca2+ concentrations. Binding experiments were performed using progesterone-11α-glucuronide-[125I]iodotyramine as tracer. Computer analysis of competition curves using different steroids as competitors indicated the presence of two distinct binding sites for P. The high affinity site (Kd in the nanomolar range) appears to be specific for P, whereas the low affinity one (Kd in the micromolar range) binds with equal affinity 11β-hydroxyprogesterone (11βOHP) and 17α-hydroxyprogesterone (17αOHP). A significant correlation exists among affinity constants (as determined by binding studies) and EC50 values for the effects of P, 11βOHP, and 17αOHP on intracellular Ca2+ in fura-2-loaded spermatozoa, strongly indicating the involvement of P-binding sites in the biological effect of the steroid. In particular, dose-response curves for P were biphasic, with an EC50 in the nanomolar range and another in the micromolar range. Conversely, curves for 11βOHP and 17αOHP were monophasic, with an EC50 just in the micromolar range. Ligand blot analysis of sperm total lysates performed with peroxidase-conjugated P revealed the presence of two binding proteins of 54 and 57 kDa that were specific for P. Indeed, peroxidase-conjugated P binding was blocked by the simultaneous presence of the unconjugated steroid. Using αc262 antibody, which is directed against the P-binding domain of genomic receptor, we detected two proteins of similar molecular mass (54 and 57 kDa), whereas using antibodies directed against the DNA-binding and N-terminal domains of the genomic P receptors, the two proteins were not detected. In addition, p54 and p57 appear to be mostly localized in sperm membranes and virtually absent in the cytoplasm. The involvement of these proteins in the biological effects of P is indicated by the strong inhibitory effect of αc262 on P-induced acrosome reaction of capacitated human spermatozoa.
Suppression of Cell Proliferation and Induction of Apoptosis in Uterine Leiomyoma by Gonadotropin-Releasing Hormone Agonist (Leuprolide Acetate)
Authors: Mizutani Takahiro , Sugihara Ayako , Nakamuro Karo , Terada Nobuyuki
Published: January 2014

Cell proliferation and apoptosis in uterine leiomyoma were investigated during therapy with GnRH agonist (GnRHa). Patients with uterine leiomyomas were injected with 3.75 mg GnRHa (depot leuprolide acetate) at intervals of 4 weeks and underwent hysterectomy or myomectomy at the 2nd, 4th, 8th, 12th, or 16th week of GnRHa therapy. Tissue sections of leiomyomas from these patients and from control patients (control patients received no GnRHa therapy) were stained with the Ki-67 antibody or by an in situ DNA 3′-end labeling method, and numbers of Ki-67 immunostained cells and DNA 3′-end-labeled cells per cm2 were examined as indices of cell proliferation and apoptosis, respectively. The number of Ki-67 immunostained cells/cm2 in leiomyomas at the 2nd week of the GnRHa therapy was comparable with that of control patients. However, it decreased to a level less than one forth that of control patients at the 4th week, and it remained at similar low levels at the 8th, 12th, and 16th week. The number of DNA 3′-end-labeled cells/cm2 in leiomyomas of control patients and in leiomyomas at the 2nd, 8th, 12th, and 16th weeks of GnRHa therapy were at low levels but, at the 4th week, was at an extremely high level (about 5 times more than that of control patients). The present results indicate that GnRHa therapy suppresses cell proliferation and causes a transient increase in apoptosis in uterine leiomyomas.
Recombinant Human Luteinizing Hormone (LH) to Support Recombinant Human Follicle-Stimulating Hormone (FSH)-Induced Follicular Development in LH- and FSH-Deficient Anovulatory Women: A Dose-Finding Study1
Authors: Group The European Recombinant Human LH Study
Published: January 2014

The efficacy of recombinant human LH (rhLH) for supporting human (rhFSH)-induced follicular development was investigated in hypogonadotropic hypogonadal women (WHO group I anovulation). Patients (n = 38) were randomized to receive rhLH (0, 25, 75, or 225 IU/day) in addition to a fixed dose of rhFSH (150 IU/day). rhLH was found 1) to promote dose-related increases in estradiol (E2) and androstenedione secretion by rhFSH-induced follicles, i.e. serum concentrations on the last day of FSH administration were 65 ± 4, 195 ± 94, 1392 ± 585, and 2441 ± 904 pmol/L for E2 and 3.6 ± 0.9, 5.1 ± 1.3, 6.4 ± 1.3, and 6.7 ± 1.3 nmol/L for androstenedione for patients treated with 0, 25, 75, and 225 IU rhLH, respectively; 2) to increase ovarian sensitivity to FSH, as demonstrated by the proportion of patients who developed follicles after the administration of a fixed dose of FSH, i.e. 1 of 8, 3 of 7, 7 of 9, and 8 of 10 in patients treated with 0, 25, 75, and 225 IU rhLH, respectively; and 3) to enhance the ability of these follicles to luteinize when exposed to hCG. A daily dose of 75 IU rhLH was effective in the majority of women in promoting optimal follicular development (defined as ≥1 follicle ≥17 mm; E2, ≥400 pmol/L; midluteal phase progesterone, ≥25 nmol/L) and maximal endometrial growth. A minority of patients may require up to 225 IU/day. rhLH, given sc at a dose up to 225 IU/day, was not immunogenic and was well tolerated.
Susceptibility of Human Placental Syncytiotrophoblastic Mitochondria to Oxygen-Mediated Damage in Relation to Gestational Age1
Authors: Watson Adrian L. , Skepper Jeremy N. , Jauniaux Eric , Burton Graham J.
Published: January 2014

When maintaining first trimester placental villi in organ culture under conventional normoxic conditions, we have observed widespread degeneration of the syncytiotrophoblast within 24 h despite excellent viability for the cytotrophoblastic and stromal cell types. Here we identify loss of mitochondrial activity as an early event in this process. In the light of proposals that the early part of gestation occurs in a low oxygen environment and also reported associations between mitochondrial disruption and oxidative stress, we cultured first trimester villi under low oxygen conditions (2.5%). Mitochondrial superoxide dismutase (MnSOD) localization and activity at different gestational ages were also determined. It was found that syncytiotrophoblastic and mitochondrial morphology improved, and mitochondrial activity was retained for 6 h and more if 8- to 10-week-old tissue was placed into a low oxygen environment immediately after removal from the uterus. The effect of oxygen concentration was less marked when using tissue of 14 weeks or more gestational age, which showed good survival and retention of mitochondrial activity under both low and ambient oxygen conditions. This correlated with our finding that placental MnSOD activity increased significantly between 8 and 14 weeks of gestation. Immunohistochemistry demonstrated that at 11 weeks, MnSOD was localized predominantly within the cytotrophoblast cells, whereas by 16 weeks it was found in the syncytiotrophoblast also. These results indicate an acute sensitivity of first trimester placenta syncytiotrophoblast to oxygen-mediated damage.
DAX-1 Expression in Human Adrenocortical Neoplasms: Implications for Steroidogenesis
Authors: Reincke M. , Beuschlein F. , Lalli E. , Arlt W. , Vay S. , Sassone-Corsi P. , Allolio B.
Published: January 2014

The DAX-1 gene encodes an orphan nuclear hormone receptor essential for normal fetal development of the adrenal cortex. Recently, DAX-1 has been shown to act as a transcriptional repressor of steroidogenic acute regulatory protein gene expression (StAR), suppressing steroidogenesis. We, therefore, investigated the expression of DAX-1 in a variety of adrenocortical tumors and compared the results with StAR mRNA expression. We found low or absent DAX-1 expression in aldosterone-producing adenomas (n=11: 35±11%; normal adrenals: 100±17%) and in aldosterone-producing adrenocortical carcinomas (n=2: 24 and 36%). Cortisol-producing adenomas showed intermediate DAX-1 expression (n=8; 92±16), as did 3 non-aldosterone-producing carcinomas (72, 132 and 132%). High DAX-1 expression was present in nonfunctional adenomas (n=3; 160±17%). In contrast to DAX-1, StAR mRNA expression did not show significant variations between groups. We did not detect the expected negative correlation between DAX-1 and StAR mRNA in adrenocortical tumors. These data suggest that high DAX-1 expression in adrenocortical tumors is associated with a non-functional phenotype whereas low DAX-1 expression favors mineralo-corticoid secretion. These effects on steroidogenesis are mediated by mechanisms other than repression of StAR gene expression. Our results indicate that DAX-1 may be one of the factors influencing the steroid biosynthesis of adrenocortical neoplasms.