bluuebunny/crossref_metadata_2025 huggingface dataset:
Activating Mutation of the Stimulatory G Protein (gsp) as a Putative Cause of Ovarian and Testicular Human Stromal Leydig Cell Tumors1
Authors: Villares Fragoso Maria Candida B. , Latronico Ana Claudia , Carvalho Filomena Marino , Zerbini Maria Claudia N. , Marcondes Jose Antonio Miguel , Araujo Leila M. B. , Lando Valeria S. , Frazzatto Eliana T. , Mendonca Berenice B. , Villares Sandra Mara F.
Published: January 2014

Activating mutations of the G protein genes have been associated with the development of several endocrine neoplasms. Such activating mutations, gip2, affecting the α-subunit of the Gαi2 protein were previously described by a single group in 30% of ovarian sex cord stromal tumors. Other activating mutations of the α-subunit of the Gs (gsp) have been identified in GH-secreting and nonfunctioning pituitary tumors, autonomous thyroid adenomas, and all affected McCune-Albright tissues, but not in sex cord stromal tumors. In the present study, we investigated the presence of gip2 and gsp mutations in 14 human sex cord stromal tumors. Six Leydig cell tumors (4 ovaries and 2 testes), 2 thecomas, 2 granulosa cell tumors, 3 androblastomas, and 1 gonadoblastoma (sex cord and germ cell) were included in this study. Genomic DNA was obtained from either fresh-frozen tumor tissues or paraffin-embedded sections and in some cases from blood samples. Using PCR, denaturing gradient gel electrophoresis, and direct sequencing, we detected 4 tumors (66.6%) with the gsp mutation (R201C) in our series of ovarian and testicular Leydig cell tumors. In contrast, no gip2 mutations were found in any of the sex cord stromal tumors studied. In conclusion, our findings suggest that the putative oncogene gsp may play a significant role in the molecular mechanism of these tumors.
Interleukin-1β Enhances Interleukin-1 Receptor Antagonist Content in Human Somatotroph Adenoma Cell Cultures1
Authors: Sauer J. , Renner U. , Hopfner U. , Lange M. , Müller A. , Strasburger C. J. , Pagotto U. , Arzt E. , Stalla G. K.
Published: January 2014

In addition to the well-known modulation of immune and inflammatory responses, the interleukin-1 (IL-1) system has been shown to be involved in the regulation of anterior pituitary hormone secretion and growth. We previously demonstrated that IL-1 receptor antagonist (IL-1ra) is expressed in human pituitary adenomas cultured in vitro. In the present study, we investigated the regulation of IL-1ra protein by IL-1β (1–100 U/mL) in human somatotroph adenomas (n = 9) cultured for 12–48 h. IL-1β significantly enhanced the concentration of IL-1ra dose dependently in the somatotroph adenoma cell lysates, whereas IL-1ra concentrations remained unchanged in the culture supernatants. Furthermore, basal IL-1ra concentrations were significantly higher in the cell lysates compared with the corresponding culture supernatants. The regulation of IL-1ra in somatotroph adenoma cells is different from human cultured monocytes, in which IL-1β significantly stimulated IL-1ra secretion into the culture supernatants, and no change of intracellular IL-1ra content was observed. Incubation of the somatotroph adenoma cells with 100 U/mL IL-1β did not result in a change of GH concentrations in the culture supernatants. Enhancement of intracellular IL-1ra protein by IL-1β may represent a mechanism intrinsic to somatotroph adenoma cells to counterregulate the response to IL-1β on hormone secretion or cellular growth.
Enhanced Slow Wave Sleep in Patients with Prolactinoma
Authors: Frieboes Ralf-Michael , Murck Harald , Stalla Günter Karl , Antonijevic Irina A. , Steiger Axel
Published: January 2014

abstract

Bidirectional interactions between nocturnal hormone secretion and sleep regulation are well established. In particular, a link between PRL and rapid eye movement (REM) sleep has been hypothesized. Short-term administration of PRL and even long-term hyperprolactinemia in animals increases REM sleep. Furthermore, sleep disorders are frequent symptoms in patients with endocrine diseases. We compared the sleep electroencephalogram of seven drug-free patients with prolactinoma (mean PRL levels 1450 ± 1810 ng/mL; range between 146 and 5106 ng/mL) with that of matched controls. The patients had secondary hypogonadism but no other endocrine abnormalities. They spent more time in slow wave sleep than the controls (79.4 ± 54.4 min in patients vs. 36.6 ± 23.5 min in controls, P < 0.05). REM sleep variables did not differ between the samples. Our data suggest that chronic excessive enhancement of PRL levels exerts influences on the sleep electroencephalogram in humans. Our result, which seems to be in contrast to the enhanced REM sleep under hyperprolactinemia in rats, leads to the hypothesis that both slow wave sleep and REM sleep can be stimulated by PRL. These findings are in accordance with reports of good sleep quality in patients with prolactinoma, which is in contrast to that of patients with other endocrine diseases.
Circulating Tumor Necrosis Factor-α Concentrations in a Native Canadian Population with High Rates of Type 2 Diabetes Mellitus1
Authors: Zinman Bernard , Hanley Anthony J. G. , Harris Stewart B. , Kwan Jeremy , Fantus I. George
Published: January 2014

Recent research suggests that tumor necrosis factor-α (TNFα) may play an important role in obesity-associated insulin resistance and diabetes. We studied the relationship between TNFα and the anthropometric and physiological variables associated with insulin resistance and diabetes in an isolated Native Canadian population with very high rates of type 2 diabetes mellitus (DM).

A stratified random sample (n = 80) of participants was selected from a population-based survey designed to determine the prevalence of type 2 DM and its associated risk factors. Fasting blood samples for glucose, insulin, triglyceride, leptin, and TNFα were collected; a 75-g oral glucose tolerance test was administered, and a second blood sample was drawn after 120 min. Insulin resistance was estimated using the homeostasis assessment (HOMA) model. Systolic and diastolic blood pressure (BP), height, weight, and waist and hip circumferences were determined, and percent body fat was estimated using biological impedance analysis. The relationship between circulating concentrations of TNFα and the other variables was assessed using Spearman correlation coefficients, analysis of covariance, and multiple linear regression.

The mean TNFα concentration was 5.6 pg/mL (sd = 2.18) and ranged from 2.0–12.9 pg/mL, with no difference between men and women (P = 0.67). There were moderate, but statistically significant, correlations between TNFα and fasting insulin, HOMA insulin resistance (HOMA IR) waist circumference, fasting triglyceride, and systolic BP (r = 0.23–0.34; all P < 0.05); in all cases, coefficients for females were stronger than those for males. Individuals with normal glucose tolerance had lower log TNFα concentrations than those with impaired glucose tolerance or type 2 DM (both P = 0.03, adjusted for age and sex), although differences were not significant after adjustment for HOMA IR (both P > 0.25). Regression analysis indicated that log HOMA IR and log systolic BP were significant independent contributors to variations in log TNFα concentration (model r2 = 0.32). We conclude that in this homogeneous Native Canadian population, circulating TNFα concentrations are positively correlated with insulin resistance across a spectrum of glucose tolerance. The data suggest a possible role for TNFα in the pathophysiology of insulin resistance.
Linkage of Familial Euthyroid Goiter to the Multinodular Goiter-1 Locus and Exclusion of the Candidate Genes Thyroglobulin, Thyroperoxidase, and Na+/I− Symporter*
Authors: Neumann Susanne , Willgerodt Helmut , Ackermann Frank , Reske Andreas , Jung Martin , Reis André , Paschke Ralf
Published: January 2014

Iodine deficiency is the most important etiological factor for euthyroid endemic goiter. However, family and twin pair studies also indicate a genetic predisposition for euthyroid simple goiter. In hypothyroid goiters several molecular defects in the thyroglobulin (TG), thyroperoxidase (TPO), and Na+/I− symporter (NIS) genes have been identified. The TSH receptor with its central role for thyroid function and growth is also a strong candidate gene. Therefore, we investigated a proposita with a relapsing euthyroid goiter and her family, in which several members underwent thyroidectomy for euthyroid goiter. Sequence analysis of the complementary DNA (cDNA) of the TPO and TSH receptor genes revealed several previously reported polymorphisms. As it is not possible to exclude a functional relevance for all polymorphisms, we opted for linkage analysis with microsatellite markers to investigate whether the candidate genes are involved in the pathogenesis of euthyroid goiter. The markers for the genes TG, TPO, and NIS gave two-point and multipoint logarithm of odds score analysis scores that were negative or below 1 for all assumed recombination fractions. As no significant evidence of linkage was found, we conclude that these candidate genes can be excluded as a major cause of the euthyroid goiters in this family. In contrast, we have found evidence for linkage of familial euthyroid goiter to the recently identified locus for familial multinodular nontoxic goiter (MNG-1) on chromosome 14q. The haplotype cosegregates clearly with familial euthyroid goiter. Our results provide the first confirmation for MNG-1 as a locus for nontoxic goiter.
Apparent Cortisone Reductase Deficiency: A Functional Defect in 11β-Hydroxysteroid Dehydrogenase Type 1*
Authors: Jamieson A. , Wallace A. M. , Andrew R. , Nunez B. S. , Walker B. R. , Fraser R. , White P. C. , Connell J. M. C.
Published: January 2014

A 36-yr-old woman was referred to the endocrine clinic for investigation of oligomenorrhea, hirsutism, and acne. She was plethoric and overweight with central fat distribution. Plasma cortisol was normal, but her adrenal glands were enlarged (CT scan). Urinary tetrahydrocortisone excretion rate was consistently high, raising the possibility of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) deficiency. In addition, 5β- reduction of cortisol and cortisone was markedly enhanced. The levels of all cortisol metabolites were suppressed normally with dexamethasone, but conversion of oral cortisone acetate to plasma cortisol was delayed and subnormal compared with that of healthy volunteers. This was accompanied by a larger than normal increase in plasma cortisone concentration. Thus, the defect appears to be in 11β-HSD1 activity and not in 5β-reductase activity. Three close relatives of the subject showed no comparable abnormalities, and analysis of the coding region and exon/intron boundaries of the 11β-HSD1 gene of the case revealed no differences from the consensus sequence. The defect may lie outside the coding region. Alternatively, some other inherited or acquired defect may lead to inhibition of this enzyme system.
Daily Treatment with Human Recombinant Parathyroid Hormone-(1–34), LY333334, for 1 Year Increases Bone Mass in Ovariectomized Monkeys*
Authors: Brommage Robert , Hotchkiss Charlotte E. , Lees Cynthia J. , Stancill Melanie W. , Hock Janet M. , Jerome Christopher P.
Published: January 2014

PTH stimulates bone formation to increase bone mass and strength in rats and humans. The aim of this study was to determine the skeletal effects of recombinant human PTH-(1–34) [rhPTH-(1–34)] in monkeys, as monkey bone remodeling and structure are similar to those in human bone.

Adult female cynomolgus monkeys were divided into sham-vehicle (n= 21), ovariectomized (OVX)-vehicle (n = 20), and OVX groups given daily sc injections of rhPTH-(1–34) at 1 (n = 39) or 5 (n = 41) μg/kg for 12 months. Whole body bone mineral content was measured, as was bone mineral density (BMD) in the spine, proximal tibia, midshaft radius, and distal radius. Serum and urine samples were also analyzed. rhPTH-(1–34) treatment did not influence serum ionized Ca levels or urinary Ca excretion, but depressed endogenous PTH while increasing serum calcitriol levels. Compared to that in the OVX group, the higher dose of rhPTH-(1–34) increased spine BMD by 14.3%, whole body bone mineral content by 8.6%, and proximal tibia BMD by 10.8%. Subregion analyses suggested that the anabolic effect of rhPTH-(1–34) on the proximal tibia was primarily in cancellous bone. Similar, but less dramatic, effects on BMD were observed with the lower dose of rhPTH-(1–34). Daily sc rhPTH-(1–34) treatment for 1 yr increases BMD in ovariectomized monkeys without inducing sustained hypercalcemia or hypercalciuria.
Hormonal and Biochemical Parameters in the Determination of Osteoporosis in Elderly Men*
Authors: Center Jacqueline R. , Nguyen Tuan V. , Sambrook Philip N. , Eisman John A.
Published: January 2014

The extent to which changes in several hormonal and biochemical parameters are involved in the pathogenesis of osteoporosis in men remains controversial. This study examined the roles of free testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), 25-hydroxyvitamin D, PTH, and insulin-like growth factor I in the determination of bone mineral density (BMD) in 437 community-dwelling elderly men. Age, height, weight, quadriceps strength, and femoral neck (FN) and lumbar spine (LS) BMD were also obtained. In multiple regression analysis, after adjusting for age and weight, low E2 (P = 0.01), and high SHBG (P = 0.0002) levels were common determinants of FN and LS BMD. In addition, high PTH (P = 0.03) was an independent predictor of FN BMD, and low free T (P = 0.02) was an independent predictor of LS BMD. Low free T was associated with FN BMD in univariate analysis only. The hormonal measurements collectively accounted for 5% and 7% of the age- and weight-adjusted variance of FN and LS BMD, respectively. The sex steroids, SHBG and insulin-like growth-I were found to be interrelated using a technique of path analysis that examines the intercorrelation between these variables. A subject with any one abnormal serum parameter had a 4-fold increase in the risk of osteoporosis, whereas three abnormal parameters were associated with an 11-fold increased risk, although the latter group only applied to 1% of the study population. Although the precise causal effects these biochemical parameters may have on the development of osteoporosis remains to be determined, the present findings support an important interrelated role for these hormonal and biochemical parameters on changes in bone density in elderly men.
Corticotropin-Releasing Hormone Stimulates P450 17α-Hydroxylase/17,20-Lyase in Human Fetal Adrenal Cells via Protein Kinase C*
Authors: Chakravorty Aruna , Mesiano Sam , Jaffe Robert B.
Published: January 2014

CRH directly stimulates dehydroepiandrosterone sulfate (DHEAS) production in human fetal adrenal cells. In the human fetal and adult pituitary, CRH acts via protein kinase A (PKA). We determined the CRH signal transduction pathway in fetal adrenal cells, i.e. whether CRH modulates human fetal adrenal steroidogenesis via PKA and/or protein kinase C (PKC).

In primary cultures, CRH increased inositol trisphosphate. After CRH treatment, inositol tris-, bis-, and monophosphates increased within 1 min, reaching maximal levels at 5 min. In contrast, PGF2α, known to act via PKC, induced a sustained response for up to 20 min. The response to CRH was dose dependent, maximal at 1μ mol/L at both 1 and 5 min. CRH increased DHEAS production, with a much lesser effect on cortisol. CRH did not stimulate inositol phospholipid in adult adrenal glands, suggesting that this pathway is unique to the fetal adrenal. CRH increased messenger ribonucleic acid encoding 17α-hydroxylase/17,20 lyase (P450c17), but not 3β-hydroxysteroid dehydrogenase/Δ4–5 isomerase. However, 3βHSD expression was stimulated by ACTH. PKC, but not PKA, inhibitors blocked CRH-stimulated P450c17 induction, whereas PKA inhibitors blocked ACTH-stimulated cortisol. Thus, CRH is coupled to the phospholipase C-inositol phosphate second messenger system and preferentially induces the expression of P450c17 and DHEAS, suggesting a unique role of CRH regulating human fetal adrenal function via PKC.
Dissociative Glucocorticoid Activity of Medroxyprogesterone Acetate in Normal Human Lymphocytes1
Authors: Bamberger Christoph M. , Else Tobias , Bamberger Ana-Maria , Ulrich Beil Frank , Schulte Heinrich M.
Published: January 2014

The immunosuppressive effects of glucocorticoids (GC) have led to their wide application in the treatment of inflammatory and autoimmune states. However, long term GC treatment is associated with severe side-effects. The development of agents displaying a more favorable ratio of wanted and unwanted GC effects, is, therefore, a major goal of pharmacological and clinical research. In this study, the progesterone receptor agonist medroxyprogesterone acetate (MPA), which also binds to the glucocorticoid receptor (GR), was tested with regard to its immunosuppressive properties. Using a recently established electroporation protocol, we show that MPA (but not progesterone) can suppress a human interleukin-2 (IL-2) promoter-luciferase construct to the same extent as the synthetic GC dexamethasone in normal human lymphocytes. MPA also markedly suppressed IL-2 (as well as IL-1 and IL-6) release, as assessed by specific enzyme-linked immunosorbent assays. In contrast, a highly dexamethasone-inducible glucocorticoid response element-driven promoter construct was only marginally stimulated by MPA in both normal human lymphocytes and HeLa cells. RT-PCR and Western blot analysis of normal human lymphocytes revealed that they do not express progesterone receptor messenger ribonucleic acid and protein, respectively. In contrast, the GR protein was clearly detectable in all samples and was shown to mediate the effects of MPA in transfected Jurkat T lymphoma cells. Our data indicate that 1) MPA can transrepress the human IL-2 gene in normal human lymphocytes in the absence of significant trans-activation; and 2) this effect is mediated by GR. Because of its dissociative GC activity, MPA is a highly promising substance for the treatment of inflammatory/autoimmune states.
Effect of Severe Growth Hormone (GH) Deficiency due to a Mutation in the GH-Releasing Hormone Receptor on Insulin-Like Growth Factors (IGFs), IGF-Binding Proteins, and Ternary Complex Formation Throughout Life1
Authors: Aguiar-Oliveira Manuel H. , Gill Matthew S. , de Elenilde S. , Barretto A. , Alcântara Marta R. S. , Miraki-Moud Farideh , Menezes Carlos A. , Souza Anita H. O. , Martinelli Carlos E. , Pereira F. A. , Salvatori Roberto , Levine Michael A. , Shalet Stephen M. , Camacho-Hubner Cecilia , Clayton Peter E.
Published: January 2014

Measurement of the insulin-like growth factors (IGFs) and their binding proteins has become commonplace in the indirect assessment of the integrity of the GH axis. However, the relative effect of GH deficiency (GHD) on each component of the IGF axis and the merit of any one parameter as a diagnostic test have not been defined in a homogeneous population across all ages. We therefore measured IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-2, IGFBP-3, and acid labile subunit (ALS) in 27 GHD subjects (aged 5–82 yr) from an extended kindred in Northeast Brazil with an identical GHRH receptor mutation and in 55 indigenous controls (aged 5–80 yr). The effect of GHD on the theoretical distribution of IGFs between the IGFBPs and the ternary complex was also examined.

All components of the IGF axis, measured and theoretical, showed complete separation between GHD and control subjects, except IGFBP-1 and IGFBP-2 concentrations, which did not differ. The most profound effects of GHD were on total IGF-I, IGF-I in the ternary complex, and ALS. The proportion of IGF-I associated with IGFBP-3 remained constant throughout life, but was significantly lower in GHD due to an increase in IGF-I/IGFBP-2 complexes. IGF-I in the ternary complex was determined principally by concentrations of ALS in GHD and IGFBP-3 in controls, implying that ALS has greater GH dependency. In the controls, IGF-II was associated primarily with IGFBP-3 and to a lesser extent with IGFBP-2, whereas in GHD the reverse was found. There was also a dramatic decline in the proportion of free ALS in GHD adults that was not evident in controls. As diagnostic tests, IGF-I in the ternary complex and total IGF-I provided the greatest separation between GHD and controls in childhood. Similarly, in older adults the best separation was achieved with IGF-I in the ternary complex, with free ALS being optimal in younger adults.

Severe GHD not only reduces the amounts of IGFs, IGFBP-3, and ALS, but also modifies the distribution of the IGFs bound to each IGFBP. Diagnostic tests used in the investigation of GHD should be tailored to the age of the individual. In particular, measurement of IGF-I in the ternary complex may prove useful in the diagnosis of GHD in children and older adults, whereas free ALS may be more relevant to younger adults.
Sibling Pair Linkage and Association Studies between Bone Mineral Density and the Insulin-Like Growth Factor I Gene Locus1
Authors: Takacs Istvan , Koller Daniel L. , Peacock Munro , Christian Joe C. , Hui Siu L. , Conneally P. Michael , Johnston C. Conrad , Foroud Tatiana , Econs Michael J.
Published: January 2014

A major determinant of the risk for osteoporosis in later life is bone mineral density (BMD) attained during early adulthood. BMD is a complex trait that presumably is influenced by multiple genes. Insulin-like growth factor I (IGF-I) is an attractive candidate gene for osteoporosis susceptibility, because IGF-I has marked effects on bone cells and has been implicated in the pathogenesis of osteoporosis. The IGF-I gene contains a microsatellite repeat polymorphism approximately 1 kb upstream from the IGF-I gene transcription start site, and previous investigators have found a higher prevalence of the 192/192 genotype of this polymorphism among men with idiopathic osteoporosis compared to controls. In this study we used this IGF-I polymorphism to test for an association between this polymorphism and BMD in our large population of premenopausal women (1 sister randomly chosen from 292 Caucasian and 71 African-American families). We also used this polymorphism to detect linkage to BMD elsewhere in the IGF-I gene or in a nearby gene using sibling pair linkage analysis in healthy premenopausal sister pairs (542 sibling pairs: 418 Caucasian and 124 African-American). Neither test provided any evidence of linkage or association between the IGF-I gene locus and spine or femoral neck BMD in Caucasians or African-Americans.
Changes in Plasma Leptin during the Treatment of Diabetic Ketoacidosis
Authors: Hathout Eba H. , Sharkey Jeannine , Racine Michael , Ahn David , Mace John W. , Saad Mohammed F.
Published: January 2014

To test the hypothesis that insulin regulates leptin, we measured the plasma leptin concentration before and during treatment of diabetic ketoacidosis (DKA), a condition characterized by extreme insulin deficiency. The study included 17 patients with type 1 diabetes (7 males and 10 females), aged 10 ± 1 yr (mean ± se), with a body mass index of 17.6 ± 1.9 kg/m2. Patients were treated with continuous insulin infusion and fluid and electrolyte replacement. Plasma leptin was measured every 6 h in the first 24 h, during which patients received a total insulin dose of 0.6–2.0 U/kg. Plasma leptin concentrations were also measured in a control group of 29 stable type 1 diabetic children (12 males and 17 females) and 25 healthy children (11 males and 14 females), aged 11 ± 1 yr, with a body mass index of 18.5 ± 1.1 kg/m2. Before treatment, plasma leptin concentrations were significantly lower in patients with DKA than those in diabetic and healthy controls (4.9± 1.2 vs. 9.0 ± 1.8 and 11.2 ± 2.1 ng/mL, respectively; P < 0.05). In the DKA patients, plasma leptin increased to 6.4 ± 1.5, 7.5 ± 1.9, 9.1± 2.7, and 8.9 ± 2.5 at 6, 12, 18, and 24 h, respectively, after starting treatment (P = 0.001). Thus, leptin levels increased by 38 ± 10% and 92 ± 38% within 6 and 24 h of starting treatment. There was no difference in the change in plasma leptin by 24 h between subjects who could eat (n = 7) and those who could not (n = 10). The plasma leptin increase was paralleled by a rise in insulin level and a decline in glucose and cortisol levels at 6 and 24 h. In conclusion, DKA was associated with decreased plasma leptin concentrations. Treatment resulted in a significant increase in plasma leptin, which may be due to the effect of insulin on leptin production. Our data lend support to the hypothesis that insulin is the link between caloric intake and plasma leptin.
Effects of Calcium Supplementation on Calcium Homeostasis and Bone Turnover in Lactating Women1
Authors: Kalkwarf Heidi J. , Specker Bonny L. , Ho Mona
Published: January 2014

Lactation is a time of calcium flux, because women secrete approximately 210 mg calcium/day in breast milk, and they experience a transient bone loss. The objectives of this study were to determine the effect of calcium supplementation on adaptive responses in calcium homeostasis during lactation and after weaning. Two cohorts of women participated in a 6-month randomized calcium supplementation trial. Lactation cohort women (97 lactating, 99 nonlactating) were studied during the first 6 months post partum, and weaning cohort women (95 lactating, 92 nonlactating) were studied during the second 6 months post partum. Lactating women in the weaning cohort weaned approximately 1.5 months after enrollment. PTH was 18–30% lower in lactating than in nonlactating women (P < 0.01). Serum 1,25-dihydroxyvitamin D was 11–16% higher in lactating than in nonlactating women and remained elevated for approximately 1.5 months after weaning (P = 0.06). Calcium supplementation decreased serum PTH and 1,25-dihydroxyvitamin D in lactating and nonlactating women similarly. At 6 months, the calciuric response to calcium supplementation was less in lactating (compared with nonlactating) women (P = 0.06). Biomarkers of bone turnover were higher in lactating than in nonlactating women during lactation and after weaning but were not effected by calcium supplementation. Calcium supplementation has little effect on lactation-induced changes in the calcium economy.
Species-Specific Autoantibodies in Type 1 Diabetes1
Authors: Hampe C. S. , Örtqvist E. , Rolandsson O. , Landin-Olsson M. , Törn C. , Ågren Å. , Persson B. , Schranz D. B. , Lernmark Å.
Published: January 2014

GAD65 autoantibodies (GAD65Ab) are important markers for type 1 (insulin-dependent) diabetes mellitus. Although most patients have GAD65Ab at the time of clinical diagnosis, there are also GAD65Ab-positive individuals in the population at low risk of developing type 1 diabetes. The aim of this study was to test the hypothesis that the GAD65Ab reactivity to GAD65 cloned from human, mouse, and rat in newly diagnosed type 1 diabetic patients differ from antibody-positive healthy individuals. Sera from 254 new-onset 0- to 34-yr-old type 1 diabetic patients and 270 controls were assayed for their reactivity to human, mouse, and rat GAD65. Among the type 1 diabetic patients there was a significant better binding of human GAD65 compared to either mouse (P = 0.03) or rat GAD65 (P = 0.0005). The preference for human GAD65 increased with increasing age at onset (P = 0.0002). This differentiation was not observed in 88 GAD65Ab-positive control subjects. Our data indicate that recognition of epitopes by GAD65Ab in type 1 diabetes is different from that in nontype 1 diabetes, GAD65Ab-positive individuals.
Evaluation of the Adequacy of Levothyroxine Replacement Therapy in Patients with Central Hypothyroidism1
Authors: Ferretti Elisabetta , Persani Luca , Jaffrain-Rea Marie-Lise , Giambona Salvatore , Tamburrano Guido , Beck-Peccoz Paolo
Published: January 2014

As there are few data on the evaluation of the adequacy of levothyroxine (l-T4) therapy in patients with central hypothyroidism (CH), a prospective study was performed to assess the accuracy of various parameters in the follow-up of 37 CH patients. Total and free thyroid hormones, TSH, and a series of clinical and biochemical indexes of peripheral thyroid hormone action have been evaluated off and on l-T4 therapy. Samples were taken before the daily administration of l-T4. In all patients off therapy, clinical hypothyroidism and low levels of free T4 (FT4) were observed, whereas values of FT3, total T4, and total T3 were below the normal range in 73%, 57%, and 19% of cases, respectively. Most of the indexes of thyroid hormone action were significantly modified after l-T4 withdrawal and exhibited significant correlation with free thyroid hormone levels. During l-T4 replacement therapy, 32 patients had circulating levels of FT4 and FT3 and indexes within the normal range with a mean l-T4 daily dose of 1.5 ± 0.3 μg/kg BW. Despite normal serum FT4, 3 patients had borderline high values of FT3 and a clear elevation of serum-soluble interleukin-2 receptor concentrations, suggesting overtreatment. Low or borderline low FT4/FT3 levels indicated undertreatment in 2 patients. The clinical parameters lack the required specificity for the diagnosis or follow-up of CH patients. The l-T4 daily dose should be established, taking into account the weight, the age, and the presence of other hormone deficiencies or pharmacological treatment of CH patients.

In conclusion, our results indicate that the diagnosis of CH is reached at best by measuring TSH and FT4 concentrations. In the evaluation of the adequacy of l-T4 replacement therapy, both FT4 and FT3 serum levels together with some biochemical indexes of thyroid hormone action are all necessary to a more accurate disclosure of over- or undertreated patients.
11β-Hydroxysteroid Dehydrogenase Type 2 and Mineralocorticoid Receptor in Human Fetal Development
Authors: Hirasawa Gen , Sasano Hironobu , Suzuki Takashi , Takeyama Junji , Muramatu Yasunari , Fukushima Kouhei , Hiwatashi Nobuo , Toyota Takayoshi , Nagura Hiroshi , Krozowski Zygmunt S.
Published: January 2014

11β-Hydroxysteroid dehydrogenase type II (11βHSD2) confers specificity on the mineralocorticoid receptor (MR) by converting biologically active glucocorticoids to inactive 11-keto metabolites. The biological significance of 11βHSD2 activity during fetal development is currently being explored, but the temporal and spatial distributions of the enzyme and receptor have not been examined. We therefore examined their distributions during various stages of human fetal development using immunohistochemistry. Both 11βHSD2 and MR immunoreactivity were detected in the distal convoluted and collecting tubules of the kidney from early in gestation. Fetal skin, intermediate layer of the epidermis, peridermal cells, and hair follicles were positive for both 11βHSD2 and MR. Weak 11βHSD2 and MR immunoreactivity was detected in the superficial ciliated epithelium of the esophagus, the deep layer of gastric epithelial cells, and the superficial epithelium of the small intestine. Columnar epithelium in the terminal bronchiolar budding component of fetal lung and tracheal and bronchial ciliated epithelium were also positive for MR and 11βHSD2 from early gestation. Colonic epithelium and pancreatic exocrine duct cells, which demonstrated marked immunoreactivity of both MR and 11βHSD2 in the adult, did not express MR and 11βHSD2 until very late in gestation. These results imply that mineralocorticoid action in the upper fetal gastrointestinal tract, kidney, skin, and lung is facilitated by 11βHSD2 and is involved in water and electrolyte transport between fetus and amniotic fluid as well as fetal urine production.
17β-Hydroxysteroid Dehydrogenase Type 1, 2, 3, and 4 Expression and Enzyme Activity in Human Anterior Pituitary Adenomas
Authors: Green V. L. , Speirs V. , Landolt A. M. , Foy P. M. , Atkin S. L.
Published: January 2014

17β-Hydroxysteroid dehydrogenase (17βHSD) isoforms reversibly catalyze the final step in the formation of estradiol (E2) from estrone (E1) and the formation of testosterone from androstenedione. We have investigated 17βHSD type 1, 2, 3, and 4 gene expression and 17βHSD estrogenic activity in human anterior pituitary adenomas. 17βHSD messenger ribonucleic acid (mRNA) expression was studied by RT-PCR in 42 pituitary tumors and 3 normal pituitaries, 17βHSD activity was studied in 11 tumors and 17βHSD type 1 was immunolocalized in vitro in 6 tumors. 17βHSD type 1 gene expression was detected in 34 of 42 adenomas in all tumor subtypes; 17βHSD type 2 mRNA was detected in 18 of 42 adenomas, but not in prolactinomas; 17βHSD type 3 mRNA was detected in 12 of 42 adenomas, but not in corticotropinomas; 17βHSD type 4 was expressed in 20 of 42 adenomas by all adenoma subtypes. Reversible 17βHSD activity was found in 9 of 11 adenomas, and 17βHSD type 1 immunopositivity was cytoplasmically distributed in all 6 adenomas in vitro. All 4 17βHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17βHSD enzyme activity, suggesting that 17βHSD may play an important role in regulating the local cellular levels of estradiol.
The Differential Expression of Myometrial Connexin-43, Cyclooxygenase-1 and -2, and Gsα Proteins in the Upper and Lower Segments of the Human Uterus during Pregnancy and Labor1
Authors: Sparey Colette , Robson Stephen C. , Bailey Jarrod , Lyall Fiona , Nicholas Europe-Finner G.
Published: January 2014

There is evidence from many studies indicating that a number of specific quiescent and contractile associated proteins are temporally regulated in the myometrium during pregnancy. In this present investigation we provide data that strongly suggest that myometrial connexin-43, cyclooxygenase-1 and -2 (COX-1 and -2), and Gsα proteins are also spatially expressed within the human uterus during pregnancy and labor. Using paired lower and upper segment myometrial samples taken from individual women at term and during spontaneous labor, we have measured the expression of these proteins by immunoblotting with specific antibodies. We report that the myometrial gap junction connexin-43 protein is expressed at much greater levels in the upper uterine compared to the lower uterine segment and that this difference is even more pronounced during the course of labor. Conversely, myometrial COX-1 and -2 proteins appear to be expressed at much greater levels in the lower compared to the upper uterine segment. Moreover, the level of expression of both proteins is unaffected by the onset of parturition. In contrast, myometrial Gsα protein appears to be uniformly expressed in both lower and upper segments and is similarly down-regulated during parturition, as previously reported. The differential expression of COX-1 and -2 and connexin-43 in the uterus may allow cervical ripening before and dilatation during labor and facilitate effective propagation of contractions from fundus to cervix, which may be further facilitated by the down-regulation of Gsα at the onset of parturition.
Cavernous Sinus Sampling Is Highly Accurate in Distinguishing Cushing’s Disease from the Ectopic Adrenocorticotropin Syndrome and in Predicting Intrapituitary Tumor Location1
Authors: Graham Kathryn E. , Samuels Mary H. , Nesbit Gary M. , Cook David M. , O’Neill Oisin R. , Barnwell Stanley L. , Loriaux D. Lynn
Published: January 2014

Inferior petrosal sinus sampling (IPSS) is used to distinguish pituitary Cushing’s disease from occult cases of the ectopic ACTH syndrome, but is limited in that it requires the use of ovine CRH (oCRH) and is not highly accurate at predicting the intrapituitary location of tumors. This study was designed to determine whether cavernous sinus sampling (CSS) is as safe and accurate as IPSS, whether CSS can eliminate the need for oCRH stimulation, and whether CSS can accurately predict the intrapituitary location of tumors.

Ninety-three consecutive patients with ACTH-dependent Cushing’s syndrome were prospectively studied with bilateral, simultaneous CSS before and after oCRH stimulation. Prediction of a pituitary or ectopic ACTH source was based on cavernous/peripheral plasma ACTH ratios. Intrapituitary tumor location was predicted based on lateralization (side to side) ACTH ratios. These predictions were compared to surgical outcome in the 70 patients who had surgically proven pituitary (n= 65) or ectopic (n = 5) disease.

CSS distinguished pituitary Cushing’s disease from the ectopic ACTH syndrome in 93% of patients with proven tumors before oCRH administration and in 100% of patients with proven tumors after oCRH. It was as safe and efficacious as published IPSS results. CSS accurately predicted the intrapituitary lateralization of the tumor in 83% of all patients and 89% of those patients with good catheter position and symmetric venous flow.

CSS is as safe and accurate as IPSS for distinguishing patients with pituitary Cushing’s disease from those with the ectopic ACTH syndrome. In addition, CSS appears to be superior to IPSS for predicting intrapituitary tumor lateralization.
Interactions between Growth Hormone, Insulin-Like Growth Factor I, and Basic Fibroblast Growth Factor in Melanocyte Growth1
Authors: Edmondson Stephanie R. , Russo Vincenzo C. , McFarlane Andrew C. , Wraight Christopher J. , Werther George A.
Published: January 2014

Melanocytes, highly differentiated neural crest-derived cells, are located in the basal layer of the epidermis, where they play a role in protecting against UV damage in the skin. Previous studies suggest that both growth hormone (GH) and the insulin-like growth factor I (GH/IGF-I) system may be important for melanocyte growth and function. We have therefore characterized the role of the GH/IGF system in melanocyte growth in vitro and its interaction with the local growth factor basic fibroblast growth factor (bFGF). Analysis of the effects of GH, IGF-I, and bFGF and combinations of these growth factors on melanocyte growth in vitro revealed that 1) GH stimulates the growth of melanocytes when combined with IGF-I, des(1–3)IGF-I [an analog of IGF-I that has a reduced binding affinity for IGF-binding proteins (IGFBPs)], or bFGF, either separately or in combination; 2) in contrast to the lack of effect of GH or bFGF alone, both IGF-I and des(1–3)IGF-I enhance melanocyte growth in a dose-dependent manner; and 3) IGF-I is more efficacious in eliciting a growth response at low concentrations compared to des(1–3)IGF-I. Using Western ligand blotting, affinity cross-linking, immunoprecipitation, RIA, and Northern analysis, we show that cultured human melanocytes synthesize and secrete minimal amounts of IGFBP. IGFBP-4 is the major IGFBP produced by these cells when cultured in complete growth medium or in the presence of either IGF-I or des(1–3)IGF-I alone. In conclusion, these studies provide support for a role for both GH and IGF-I in the growth of human melanocytes in vitro, involving synergy with bFGF. Low levels of melanocyte-derived IGFBP-4 may play a role in enhancing the modulation of IGF action.
Stress Echocardiography in Hyperthyroidism
Authors: Kahaly George J. , Wagner Stephan , Nieswandt Jana , Mohr-Kahaly Susanne , Ryan Thomas J.
Published: January 2014

Exertion symptoms occur frequently in subjects with hyperthyroidism. Using stress echocardiography, exercise capacity and global left ventricular function can be assessed noninvasively. To evaluate stress-induced changes in cardiovascular function, 42 patients with untreated thyrotoxicosis were examined using exercise echocardiography. Studies were performed during hyperthyroidism, after treatment with propranolol, and after restoration of euthyroidism. Twenty- two healthy subjects served as controls. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol starting at 20 watts/min. In contrast to control and euthyroidism, the change in end-systolic volume index from rest to maximal exercise was lower in hyperthyroidism. At rest, the stroke volume index, ejection fraction, and cardiac index were significantly increased in hyperthyroidism, but exhibited a blunted response to exercise, which normalized after restoration of euthyroidism. Propranolol treatment also led to a significant increase of delta (Δ) stroke volume index. Maximal work load and Δ heart rate were markedly lower in hyper- vs. euthyroidism. Compared to the control value, systemic vascular resistance was lowered by 36% in hyperthyroidism at rest, but no further decline was noted at maximal exercise. The Δ stroke volume index, Δ ejection fraction, Δ heart rate, and maximal work load were significantly reduced in severe hyperthyroidism. Negative correlations between free T3 and diastolic blood pressure, maximal work load, Δ heart rate, and Δ ejection fraction were noted. Thus, in hyperthyroidism, stress echocardiography revealed impaired chronotropic, contractile, and vasodilatatory cardiovascular reserves, which were reversible when euthyroidism was restored.
Colocalization of Progesterone Receptors A and B by Dual Immunofluorescent Histochemistry in Human Endometrium during the Menstrual Cycle1
Authors: Mote P. A. , Balleine R. L. , McGowan E. M. , Clarke C. L.
Published: January 2014

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, that function as ligand-activated transcription factors. In vitro studies suggest that the isoforms differ functionally and that the relative levels in a target cell may determine the nature and magnitude of response to progesterone. However, it is not known whether the two isoforms are normally coexpressed in vivo. To understand the functional significance of relative PR isoform expression in normal physiology, it is essential to determine whether PRA and PRB are coexpressed in the same cell. This study reports the development of a dual immunofluorescent staining technique to demonstrate PRA and PRB proteins by single cell analysis in the same tissue section of human endometrium during the menstrual cycle. PRA and PRB are coexpressed in target cells of the human uterus. In the glands, PRA and PRB were expressed before subnuclear vacuole formation and glycogenolysis, implicating both isoforms in this process, whereas persistence of PRB during the midsecretory phase suggested its significance in glandular secretion. In the stroma, the predominance of PRA throughout the cycle implicates this isoform in postovulatory progesterone-mediated events. These results support the view that PRA and PRB mediate distinct pathways of progesterone action in the glandular epithelium and stroma of the human uterus throughout the menstrual cycle.
Cortisolemic Indices Predict Severe Infections in Cushing Syndrome Due to Ectopic Production of Adrenocorticotropin1
Authors: Sarlis Nicholas J. , Chanock Stephen J. , Nieman Lynnette K.
Published: January 2014

Because high circulating levels of glucocorticoids impair immunity and predispose to infections, we evaluated whether indices of cortisol (F) production could predict infections in patients with Cushing syndrome (CS) caused by ectopic production of ACTH (EA).

Charts of 54 consecutive patients with untreated EA, without underlying diagnosis of small cell carcinoma of the lung, were reviewed, and types of infections, white blood cell (WBC) count, fever, as well as the glucocorticoid indices [0800 h F, daily urine F excretion (UFC), and daily urine 17-hydroxysteroid/g creatinine excretion (17OHS)], were recorded.

Thirty-five patients had no or clinically mild infection; the remaining 19 patients had severe, systemic infection (n = 13) and/or sepsis (n = 6), including either bacterial or opportunistic pathogens or both (73.7%, 42.1%, and 13.8%, respectively). The latter group of patients had significantly higher indices of hypercortisolism (F, UFC, and 17OHS) than those with mild or no infections, but these indices did not correlate with temperature or WBC count. Thresholds for identifying severe infection were selected for maximal positive predictive value and were: F, 43.1 μg/dL; UFC, 2000 μg/day; and 17OHS, 35 mg/g creatinine. The most accurate discriminator for severe infection was 17OHS, based on a positive predictive value of 64.7%.

Our data strongly suggests that the likelihood for a bacterial or opportunistic infection in CS patients, even without underlying small cell carcinoma of the lung, is greatest in patients with extreme hypercortisolism. The predictive value of total WBC count or the presence of an elevated temperature is not sufficient to identify patients with severe, life-threatening infection.
Prostate-Specific Antigen Synthesis and Secretion by Human Placenta: A Physiological Kallikrein Source during Pregnancy1
Authors: Malatesta Manuela , Mannello Ferdinando , Luchetti Francesca , Marcheggiani Francesco , Condemi Leone , Papa Stefano , Gazzanelli Giancarlo
Published: January 2014

Prostate-specific antigen (PSA), a kallikrein-like serine protease until recently thought to be prostate specific, has been demonstrated in various nonprostatic tissues and body fluids. PSA has been also found in human endometrium and amniotic fluids, even if the significance of this novel expression is unclear. In this study, we have demonstrated by multiple techniques that human placental tissue, obtained at delivery from normal full-term pregnancies, synthesizes and secretes PSA. RT-PCR showed the presence of PSA messenger ribonucleic acid; biochemical, chromatographic, and immunological studies revealed the expression of both free and complexed PSA forms; immunoelectron microscopy indicated the syncytiotrophoblast as the site of PSA synthesis and secretion. Moreover, in vitro experiments demonstrated that PSA production and secretion are up-regulated by 17β-estradiol, a pregnancy-related steroid hormone. These results suggest that human placenta is a source of the PSA present in amniotic fluid and maternal serum during pregnancy.