bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a 25-Hydroxyvitamin D3 1α-Hydroxylase Gene Transcription Product in Cultures of Human Syncytiotrophoblast Cells1
Authors: Díaz Lorenza , Sánchez Irene , Avila Euclides , Halhali Ali , Vilchis Felipe , Larrea Fernando
Published: January 2014

Although accumulating data show that placenta is able to synthesize 1,25-dihydroxyvitamin D3, the presence of cytochrome P450 enzyme capable of converting 25-hydroxyvitamin D3 (25OHD3) to the biologically active form of vitamin D in this tissue, has not been yet clearly established. In this study, we have investigated the presence of 25-hydroxyvitamin D3 1α-hydroxylase (1α-(OH)ase) gene expression products in cultured human syncytiotrophoblast. Total RNA was isolated from cultured placental cells and subjected to Northern blots or RT-PCR by using 1α-(OH)ase-specific primers. The amplified complementary DNA fragments were analyzed by gel electrophoresis and nucleotide sequencing. Total RNA from kidney HEK 293 cells was subjected to reverse transcriptase reaction, and a 298-bp complementary DNA 1α-(OH)ase probe was generated by PCR. Primary cultures of human syncytiotrophoblasts exhibited 1α-(OH)ase activity, and a transcript for this gene could be demonstrated in these cells. Northern blot analysis revealed the presence of a 2.5-kb product, similar in size to that previously reported in kidney. RT-PCR analysis demonstrated the presence of a single transcript with nucleotide sequence identical to that previously reported for human 1α-(OH)ase complementary DNA clones. In addition, data are presented which suggest that differentiation of cytotrophoblast to the syncytial state was not necessary for this gene to be expressed, which may indicate a role of this enzyme all through pregnancy. The overall results of this study provide evidence for the presence of 1α-(OH)ase in the human placenta, suggesting that conversion of 25OHD3 to 1,25-dihydroxyvitamin D3 in the trophoblast is most probably attributed to an enzymatic 1α-hydroxylation reaction.
The Prevalence and Characteristics of Colorectal Neoplasia in Acromegaly
Authors: Renehan Andrew G. , Bhaskar Pudhupalayan , Painter John E. , O’Dwyer Sarah T. , Haboubi Najib , Varma Jag , Ball Stephen G. , Shalet Stephen M.
Published: January 2014

An increased prevalence of colorectal neoplasia has been reported in acromegalic patients, and recommendations have been made for early colonoscopic screening and regular surveillance. This assumption, however, is frequently drawn from studies using selected control populations. To clarify colonoscopic management in these patients, we undertook a 2-center prospective screening colonoscopy study in 122 acromegalics (age range, 25–82 yr). In the absence of ideal age-matched controls, we calculated prevalence rates of occult adenocarcinomas and adenomas in the general population using cumulative data in the published literature from 8 autopsy studies (model 1, n = 3559) and 4 screening colonoscopy studies (model 2, n = 810), applying linear regression models. Of the 115 patients with complete examinations, adenocarcinomas were discovered in 3 (2.6%), and at least 1 adenoma was found in 11, giving an overall prevalence of neoplasia of 12% (14 of 115). Prevalence rates for age bands 30–40, 40–49, 50–59, 60–69, and 70+ yr were 0%, 8%, 12%, 20%, and 21%, respectively. Compared with the 2 control models, the prevalence of occult colorectal cancer was not significantly increased (acromegalics vs. models 1 and 2, 2.6% vs. 2.3% and 0.9%), nor was there an increase in the prevalence of adenomas in any age band. Pathological characteristics showed some differences, in that adenomas in acromegalics tended to be right sided (68% vs. 57% and 56%), larger (for ≥10 mm, 27% vs. 13% and 9%), and of advanced histology (for tubulovillous, 27% vs. 4% and 22%). No associations were found between the presence of colonic neoplasia and the duration of disease, total GH exposure, cure status, and serum insulin-like growth factor I. This study has failed to demonstrate an increased prevalence of neoplasia in acromegalic patients compared with the expected prevalence in the general population and questions the need for an aggressive colonoscopic screening policy.
Bone Size and Volumetric Density in Women with Anorexia Nervosa Receiving Estrogen Replacement Therapy and in Women Recovered from Anorexia Nervosa
Authors: Karlsson Magnus K. , Weigall Susan J. , Duan Yunbo , Seeman Ego
Published: January 2014

Anorexia nervosa is associated with bone loss during adulthood, but may also delay skeletal growth and mineral accrual during growth. We asked the following questions. 1) Is anorexia nervosa associated with reduced bone size and reduced volumetric bone mineral density (vBMD)? 2) Is estrogen replacement therapy (ERT) or recovery from anorexia nervosa associated with normal bone size and vBMD?

Using dual-energy x-ray absorptiometry, we measured bone size and vBMD of the third lumbar vertebra and femoral neck in a cross-sectional study of 161 female patients: 77 with untreated anorexia nervosa, 58 with anorexia nervosa receiving ERT, 26 recovered from anorexia nervosa, and 205 healthy age-matched controls. Results were expressed as the sd or z-score (mean ± sem).

Deficits in vertebral body and femoral neck width in untreated women were −1.0 ± 0.1 and −0.3 ± 0.1 sd (P < 0.001 and P < 0.05, respectively). Deficits in bone width were less in the ERT-treated women than in untreated women at the vertebral body (−0.6 ± 0.1 sd; P < 0.001), but not at the femoral neck (−0.4 ± 0.2 sd;P < 0.05). There were no significant deficits in vertebral body and femoral neck width in recovered women (both −0.3 ± 0.2 sd; P = NS). In untreated women, vertebral and femoral neck vBMD were −1.6 ± 0.1 and −1.1 ± 0.1 sd, respectively (both P < 0.001), less severely reduced in ERT-treated women (−1.2 ± 0.2 and −0.6 ± 0.2 sd, respectively; both P < 0.001), and least reduced in recovered women (−0.6 ± 0.1 and −0.5 ± 0.2 sd;P < 0.01 and P < 0.05, respectively). After adjusting for differences in fat and lean mass, vertebral body and femoral neck width were no longer reduced in untreated, ERT-treated, and recovered women. Adjustment for body composition had little effect on group difference in vBMD.

Bone fragility in anorexia nervosa is due to reduced bone size and reduced vBMD. Although causality cannot be inferred in cross- sectional studies, the data are consistent with the view that malnutrition may contribute to reduced bone size, whereas estrogen deficiency may reduce vBMD. The use of ERT early in disease is a reasonable component of management if the chance of recovery appears remote.
Primary Hyperaldosteronism without Suppressed Renin Due to Secondary Hypertensive Kidney Damage
Authors: Oelkers W. , Diederich S. , Bähr V.
Published: January 2014

Primary hyperaldosteronism is characterized by high plasma and urinary aldosterone and suppressed PRA. Renin suppression is due to aldosterone-dependent sodium retention and mild extracellular volume expansion. We observed three patients with primary hyperaldosteronism, severe refractory hypertension, and normal to high normal PRA levels whose aldosterone/renin ratios were still elevated because of disproportionately high aldosterone levels. All available medical data on the patients as well as publications on the aldosterone/renin relationship in primary hyperaldosteronism were reviewed to explain the unusual findings.

In one patient, histologically proven renal arteriolosclerosis was the probable cause of the escape of PRA from suppression by an aldosterone-producing adenoma. In the other two patients, hypertensive kidney damage due to primary hyperaldosteronism was the most likely explanation for the inappropriately high PRA, as in patient 1. All patients had high normal or slightly elevated serum creatinine levels and responded to 200 mg spironolactone/day with increased serum creatinine and hyperkalemia. Hyperkalemia was probably due to a decreased filtered load of sodium and a spironolactone-induced decrease in mineralocorticoid function. Two patients were cured of hyperaldosteronism by unilateral adrenalectomy but still need some antihypertensive therapy, whereas one patient has probable bilateral adrenal disease, with normal blood pressure on a low dose of spironolactone.

In patients with severe hypertension due to primary hyperaldosteronism, PRA can escape suppression if hypertensive kidney damage supervenes. An increased aldosterone/PRA ratio is still useful in screening for primary hyperaldosteronism. These patients may respond to spironolactone therapy with a strong increase in serum creatinine and potassium. Early specific treatment of primary hyperaldosteronism is therefore indicated, and even a patient with advanced hypertension will profit from adrenalectomy or cautious spironolactone treatment.
Measures of Bioavailable Serum Testosterone and Estradiol and Their Relationships with Muscle Strength, Bone Density, and Body Composition in Elderly Men*
Authors: van den Beld Annewieke W. , de Jong Frank H. , Grobbee Diederick E. , Pols Huibert A. P. , Lamberts Steven W. J.
Published: January 2014

In the present cross-sectional study of 403 independently living elderly men, we tested the hypothesis that the decreases in bone mass, body composition, and muscle strength with age are related to the fall in circulating endogenous testosterone (T) and estrogen concentrations. We compared various measures of the level of bioactive androgen and estrogen to which tissues are exposed.

After exclusion of subjects with severe mobility problems and signs of dementia, 403 healthy men (age, 73–94 yr) were randomly selected from a population-based sample. Total T (TT), free T (FT), estrone (E1), estradiol (E2), and sex hormone-binding globulin (SHBG) were determined by RIA. Levels of non-SHBG-bound T (non-SHBG-T), FT (calc-FT), the TT/SHBG ratio, non-SHBG-bound E2, and free E2 were calculated. Physical characteristics of aging included muscle strength measured using dynamometry, total body bone mineral density (BMD), hip BMD, and body composition, including lean mass and fat mass, measured by dual-energy x-ray absorptiometry.

In this population of healthy elderly men, calc-FT, non-SHBG-T, E1, and E2 (total, free, and non-SHBG bound) decreased significantly with age. T (total and non-SHBG-T) was positively related with muscle strength and total body BMD (for non-SHBG-T, respectively, β = 1.93 ± 0.52, P < 0.001 and β = 0.011 ± 0.002, P < 0.001). An inverse association existed between T and fat mass (β = −0.53 ± 0.15, P < 0.001). Non-SHBG-T and calc-FT were more strongly related to muscle strength, BMD, and fat mass than TT and were also significantly related to hip BMD. E1 and E2 were both positively, independently associated with BMD (for E2, β = 0.21 ± 0.08, P < 0.01). Non-SHBG-bound E2 was slightly strongly related to BMD than total E2. The positive relation between T and BMD was independent of E2. E1 and E2 were not related with muscle strength or body composition.

In summary, bioavailable T, E1, total E2, and bioavailable E2 all decrease with age in healthy old men. In this cross-sectional study in healthy elderly men, non-SHBG-bound T seems to be the best parameter for serum levels of bioactive T, which seems to play a direct role in the various physiological changes that occur during aging. A positive relation with muscle strength and BMD and a negative relation with fat mass was found. In addition, both serum E1 and E2 seem to play a role in the age-related bone loss in elderly men, although the cross-sectional nature of the study precludes a definitive conclusion. Non-SHBG-bound E2 seems to be the best parameter of serum bioactive E2 in describing its positive relation with BMD.
Effect of Calcium or 25OH Vitamin D3 Dietary Supplementation on Bone Loss at the Hip in Men and Women over the Age of 60*
Authors: Peacock Munro , Liu Guangda , Carey Mark , McClintock Ronald , Ambrosius Walter , Hui Siu , Johnston C. Conrad
Published: January 2014

Dietary supplements that prevent bone loss at the hip and that can be applied safely in the elderly are likely to reduce hip fractures. A daily dietary supplement of 750 mg calcium or 15 μg 25OH vitamin D3 on bone loss at the hip and other sites, bone turnover and calcium-regulating hormones were studied over 4 yr in elderly volunteers using a randomized, double-blind, placebo-controlled trial. Bone mineral density (BMD) was measured by dual x-ray absorptiometry and bone structure by radiographs. Calcium biochemistry and bone turnover markers were measured in blood and urine. The 316 women entering the trial had a mean age of 73.7 yr and the 122 men of 75.9 yr. Baseline median calcium intake was 546 mg/day, and median serum 25OH vitamin D3 was 59 nmol/L. On placebo, loss of BMD at total hip was 2% and femoral medulla expansion was 3% over 4 yr. Calcium reduced bone loss, secondary hyperparathyroidism, and bone turnover. 25OH vitamin D3 was intermediate between placebo and calcium. Fracture rates and drop-out rates were similar among groups, and there were no serious adverse events with either supplement. A calcium supplement of 750 mg/day prevents loss of BMD, reduces femoral medullary expansion, secondary hyperparathyroidism, and high bone turnover. A supplement of 15 μg/day 25OH vitamin D3 is less effective, and because its effects are seen only at low calcium intakes, suggests that its beneficial effect is to reverse calcium insufficiency.
Expression of Melanin-Concentrating Hormone Receptor Messenger Ribonucleic Acid in Tumor Tissues of Pheochromocytoma, Ganglioneuroblastoma, and Neuroblastoma1
Authors: Takahashi Kazuhiro , Totsune Kazuhito , Murakami Osamu , Sone Masahiko , Satoh Fumitoshi , Kitamuro Tomomi , Noshiro Takao , Hayashi Yutaka , Sasano Hironobu , Shibahara Shigeki
Published: January 2014

Expression of melanin-concentrating hormone (MCH) receptor messenger ribonucleic acid (mRNA) was studied by RT-PCR and Northern blot analysis in human brain; pituitary; adrenal glands; tumor tissues of adrenal tumors, ganglioneuroblastomas, and neuroblastomas; and various cultured tumor cell lines. RT-PCR analysis showed that MCH receptor mRNA was widely expressed in brain tissues, pituitary, normal portions of adrenal glands (cortex and medulla), tumor tissues of adrenocortical tumors (12 of 13 cases), pheochromocytoma (all 7 cases), ganglioneuroblastoma (1 case), neuroblastoma (all 5 cases), and various cultured tumor cell lines (6 of 7 cell lines), including 2 neuroblastoma cell lines. Northern blot analysis showed the expression of MCH receptor mRNA (∼2.4 kb) only in the tumor tissues of 5 pheochromocytomas, 1 ganglioneuroblastoma, and 4 neuroblastomas, indicating that the expression levels of MCH receptor mRNA are much higher in these tumors than in the other tissues. These findings raised the possibility that MCH or MCH-like peptides may be related to the pathophysiology of these neural crest-derived tumors.
Anabolic Effect of Estrogen Replacement on Bone in Postmenopausal Women with Osteoporosis: Histomorphometric Evidence in a Longitudinal Study1
Authors: Khastgir Gautam , Studd John , Holland Nigel , Alaghband-Zadeh Jamshid , Fox Simon , Chow Jade
Published: January 2014

It is well recognized that estrogen (E2) prevents postmenopausal bone loss by suppressing bone resorption. Despite evidence that E2 may also stimulate bone formation in animals, an anabolic effect in humans is still controversial. To investigate this, we studied 22 older postmenopausal females, with a mean age of 65.4 yr and mean interval of 16.9 yr since menopause and low bone mineral density. Transcortical iliac bone biopsies were performed before and 6 yr after E2 replacement therapy (ERT) [75 mg percutaneous E2 replaced 6-monthly plus oral medroxy progesterone acetate (5 mg daily) for 10 days each calendar month]. The mean serum E2 level after 6 yr of treatment was 1077 (range, 180-2568) pmol/L. Bone mineral density improved in every patient, with a median increase of 31.4% at the lumbar spine and 15.1% at the proximal femur. Bone histomorphometry showed an increase in cancellous bone volume from 10.75% to 17.31% (P < 0.001). The wall thickness after 6 yr of E2 treatment was 38.30 μm compared with 31.20 μm before commencement of ERT (P < 0.0005), indicating net bone gain. This is the first report showing histological evidence for an increase in cancellous bone volume, together with an increase in wall thickness, in a longitudinal follow-up study of ERT in older postmenopausal women. Our results show that E2 is capable of exerting an anabolic effect in women with osteoporosis, even when started well into the menopause.
GH Is Needed for the Maturation of Muscle Mass and Strength in Adolescents
Authors: Hulthén Lena , Bengtsson Bengt-Åke , Sunnerhagen Katharina Stibrant , Hallberg Leif , Grimby Gunnar , Johannsson Gudmundur
Published: January 2014

The postpubertal period and the early years of adulthood may be of importance for continuing tissue maturation of importance in adulthood and aging. An example of this is the peak bone mass. This study has evaluated the importance of GH for lean mass and muscle strength in adolescents and young adults. GH treatment was discontinued in 40 adolescents aged 16–21 yr with GH deficiency of childhood onset. Measurements of isometric and isokinetic knee-extensor and flexor strength, handgrip strength, lean body mass, fat-free mass, and total body nitrogen were performed annually for 2 yr. Two hundred fifty healthy adolescents were randomly selected for prospective measurements of lean mass and handgrip strength between the ages of 17 and 21 yr. In the adolescents with continuing GH deficiency, lean body mass decreased, compared with the patients defined as having sufficient endogenous GH. The isometric strength in knee flexors increased in the sufficient endogenous GH group and was unchanged in the GH deficiency group during the 2 yr off GH treatment (between group, P < 0.05). The mean and peak handgrip strength increased on average by 9–15% in the group with sufficient endogenous GH and was unchanged in those with GH deficiency (P< 0.05). Lean body mass and handgrip strength (both, P < 0.001) increased in both the healthy boys and girls who were followed for 4 yr with a more marked increase in the boys. The mean increase in handgrip between the age of 17 and 21 yr was 7–9%. The increased lean mass and improved muscle performance seen in healthy adolescents did not occur in adolescents with GH deficiency. These findings suggest that GH is of importance for the maturation of lean mass and muscle strength in adolescents and young adults.
Genetic Diagnosis of Familial Hypercholesterolemia in a South European Outbreed Population: Influence of Low-Density Lipoprotein (LDL) Receptor Gene Mutations on Treatment Response to Simvastatin in Total, LDL, and High-Density Lipoprotein Cholesterol
Authors: Chaves Felipe J. , Real José T. , García-García Ana B. , Civera Miguel , Armengod María E. , Ascaso Juan F. , Carmena Rafael
Published: January 2014

The aims of this study were to examine the presence of mutations in the low-density lipoprotein receptor gene among subjects clinically diagnosed with familial hypercholesterolemia and to analyze whether the molecular diagnosis helps to predict the response to simvastatin treatment in our familial hypercholesterolemia population. Fifty-five probands and 128 related subjects with familial hypercholesterolemia were studied. Genetic diagnosis was carried out following a three-step protocol based on Southern blot and PCR-single strand conformational polymorphism analysis. A randomized clinical trial with simvastatin was conducted in 42 genetically diagnosed subjects with familial hypercholesterolemia classified as carriers of null mutations (n = 22) and of defective mutations (n = 20). A mutation-causing familial hypercholesterolemia was identified in 46 probands (84%). In 41 of them (89%), a total of 28 point mutations were detected, 13 of which have not been previously described. The remaining five probands (11%) were carriers of large rearrangements. Familial hypercholesterolemia with null mutations showed a poor response to simvastatin treatment. The mean percentage reduction of plasma total and low-density lipoprotein cholesterol levels in these subjects were significantly lower (24.8 ± 10.3 vs. 34.8 ± 10.9, P = 0.04 and 30.0 ± 39.8 vs. 46.1 ± 18.2, P = 0.02, respectively) than in subjects with defective mutations. Baseline and posttreatment high-density lipoprotein cholesterol plasma values were significantly lower in subjects with familial hypercholesterolemia with null mutations (P < 0.001). In an outbreed Caucasian population, a three-step protocol for genetic screening detected a mutation in the low-density lipoprotein receptor gene in a high percentage (84%) of subjects with familial hypercholesterolemia. Subjects with familial hypercholesterolemia with null mutations (class I) showed lower plasma high-density lipoprotein cholesterol values and a poor low-density lipoprotein cholesterol response to simvastatin treatment.
The Postmenopausal Ovary Is Not a Major Androgen-Producing Gland
Authors: Couzinet Beatrice , Meduri Geri , Lecce Maria G. , Young Jacques , Brailly Sylvie , Loosfelt Hugues , Milgrom Edwin , Schaison Gilbert
Published: January 2014

It is currently believed that the postmenopausal ovary remains a gonadotropin-driven, androgen-producing gland. However, the adrenal contribution to circulating androgen levels may explain some conflicting results previously reported. In addition, the steroidogenic potential and gonadotropin responsiveness of the postmenopausal ovary have not been recently reassessed. Plasma T, bioavailable T, free T, androstenedione (Adione), and dehydroepiandrosterone sulfate levels were measured in postmenopausal or ovariectomized women with complete adrenal insufficiency, compared with women with intact adrenals. A stimulation human chorionic gonadotropin test (on d 0, 3, and 6) was performed in postmenopausal women with adrenal insufficiency. Dexamethasone was administered for 4 d in postmenopausal women with intact adrenals. Intraovarian T and androstenedione were also measured in homogenates of ovarian tissue from postmenopausal women. Immunocytochemistry was performed on postmenopausal ovaries and premenopausal controls to detect the presence of steroidogenic enzymes (P-450 aromatase, P-450 SCC, 3β HSD, and P-450 C17) and gonadotropin receptors. Plasma androgen levels were below or close to the limit of the assay in all women with adrenal insufficiency. They were similar in postmenopausal and oophorectomized women with normal adrenals. No hormonal changes were observed after human chorionic gonadotropin injections in women with adrenal insufficiency. In contrast, a dramatic decrease of all steroids was observed after dexamethasone administration in postmenopausal women with intact adrenals. Intraovarian T and androstenedione levels were negligible in postmenopausal ovarian tissue. P-450 aromatase was absent from the 17 ovaries studied, and the enzymes for androgen biosynthesis were either absent (n = 13) or present in very low amounts (n = 4). In all the postmenopausal ovaries, FSH and LH receptors were completely absent. In the absence of adrenal steroids, postmenopausal women have no circulating androgens. This result is consistent with the immunocytochemical studies showing the almost constantly absent steroidogenic enzymes and LH receptors in the postmenopausal ovary. Thus, the climacteric ovary is not a critical source of androgens. The arrest of androgen secretion after menopause may impact significantly on women’s health.
Effects of Suckling on Hypothalamic-Pituitary-Adrenal Axis Responses to Psychosocial Stress in Postpartum Lactating Women
Authors: Heinrichs Markus , Meinlschmidt Gunther , Neumann Inga , Wagner Sabine , Kirschbaum Clemens , Ehlert Ulrike , Hellhammer Dirk H.
Published: January 2014

In several studies lactation has been shown to be associated with a hypothalamic-pituitary-adrenal axis hyporesponsiveness to physical and psychological stressors. As it is not known whether the marked blunting of endocrine stress reactivity in women can be ascribed to suckling as a short-term effect or to lactation in general, the acute effects of suckling on the hypothalamic-pituitary-adrenal axis and the sympathetic-adrenal-medullary system responses to mental stress were investigated in lactating women.

Forty-three lactating women were randomly assigned either to breast-feed or to hold their infants for a 15-min period with the onset 30 min before they were exposed to a brief psychosocial stressor (Trier Social Stress Test). Both breast-feeding and holding the infant yielded significant decreases in ACTH, total plasma cortisol, and salivary free cortisol (all P < 0.01). There were no significant differences in baseline hormone levels between the groups 1 min before the stress test. In response to stress exposure, ACTH, total plasma cortisol, salivary free cortisol, norepinephrine, and epinephrine were significantly increased in all lactating women (all P < 0.001). However, total cortisol and free cortisol responses to stress were attenuated in breast-feeding women (P = 0.001 and P = 0.067, respectively), who also showed significantly decreasing PRL levels during the stress test (P = 0.005). In addition, there was no change in plasma oxytocin or vasopressin in response to the stressor. Breast-feeding as well as holding led to decreased anxiety (P < 0.05), whereas, in contrast, stress exposure worsened mood, calmness, and anxiety in the total group (all P < 0.001).

From these data we conclude that lactation in women, in contrast to that in rats, does not result in a general restraint of the hypothalamic-pituitary-adrenal axis response to a psychosocial stressor. Rather, suckling is suggested to exert a short-term suppression of the cortisol response to mental stress.
Plasma Fatty Acids, Adiposity, and Variance of Skeletal Muscle Insulin Resistance in Type 2 Diabetes Mellitus
Authors: Kelley David E. , Williams Katherine V. , Price Julie C. , McKolanis Therese M. , Goodpaster Bret H. , Thaete F. Lee
Published: January 2014

Skeletal muscle insulin resistance (IR) is typically severe in type 2 diabetes mellitus (DM). However, the factors that account for interindividual differences in the severity of IR are not well understood. The current study was undertaken to examine the respective roles of plasma FFA, regional adiposity, and other metabolic factors as determinants of the severity of skeletal muscle IR in type 2 DM. Twenty-three subjects (12 women and 11 men) with type 2 DM underwent positron emission tomography imaging using[ 18F]2-fluoro-2-deoxyglucose during euglycemic insulin infusions (120 mU/min·m2) to measure skeletal muscle IR, using Patlak analysis of the tissue activity curves. Body composition analysis included body mass index, fat mass, and fat-free mass by dual energy x-ray tomography, and computed tomography determinations of visceral adiposity, thigh adipose tissue distribution, and muscle composition. Body mass index, fat mass, subfascial adiposity in the thigh, and visceral adipose tissue (VAT) were all significantly related to skeletal muscle IR (r = −0.48 to −0.63; P< 0.01). However, the strongest simple correlate of IR in skeletal muscle was insulin-suppressed plasma FFA (r = −0.81; P < 0.001). VAT was the sole component of adiposity that significantly correlated with insulin-suppressed plasma FFA concentration (r = 0.64; P < 0.001). These findings indicate that the severity of skeletal muscle IR in type 2 DM is closely related to the IR of suppressing lipolysis and that plasma fatty acids and VAT are key elements mediating the link between obesity and skeletal muscle IR in type 2 DM.
The Influences of Obesity and Glycemic Control on Endothelial Activation in Patients with Type 2 Diabetes
Authors: Bagg Warwick , Ferri Claudio , Desideri Giovambattista , Gamble Greg , Ockelford Paul , Braatvedt Geoffrey D.
Published: January 2014

The aims of this study were to elucidate the factors that contribute to endothelial activation and fibrinolytic abnormalities in patients with poorly controlled type 2 diabetes and to determine whether improved glycemic control reduces endothelial activation. Adhesion molecules [E-selectin, intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1], von Willebrand factor, total nitric oxide (NO), endothelin-1, tissue plasminogen activator, and plasminogen activator inhibitor-1 were measured in 43 type 2 diabetic subjects with hemoglobin A1c of 9.0% or more at baseline (compared with 21 healthy controls) who after 20 wk had been randomized to either improved (IC) or usual (UC) glycemic control. At baseline, type 2 diabetic patients had significant endothelial activation and abnormal fibrinolysis compared with control subjects. Body mass index in the diabetic patients was the only independent predictor of E-selectin (P = 0.007), ICAM-1 (P = 0.01), and NO (P = 0.008) concentrations, but not vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, or tissue plasminogen activator (all P > 0.05). Type 2 diabetic patients with a body mass index of 28 kg/m2 or less had concentrations of E-selectin, ICAM-1, endothelin-1, and NO similar to those in healthy controls. After 20 wk, hemoglobin A1c was significantly lower in IC vs. UC (IC, 8.02 ± 0.25%; UC, 10.23 ± 0.23%; P < 0.0001), but there were no significant changes in markers of endothelial activation or indexes of fibrinolysis.

Obesity appears to be the most important predictor of endothelial activation in patients with type 2 diabetes. Short-term improvement in glycemic control does not appear to reduce endothelial activation.
Placental Transport of Leucine, Phenylalanine, Glycine, and Proline in Intrauterine Growth-Restricted Pregnancies
Authors: Paolini Cinzia L. , Marconi Anna Maria , Ronzoni Stefania , Di Noio Michela , Fennessey Paul V. , Pardi Giorgio , Battaglia Frederick C.
Published: January 2014

l-[1-13C]Leucine,[ 1-13C]glycine, l-[1-13C]phenylalanine, and l-[1-13C]proline were infused as a bolus into the maternal circulation of seven appropriate for gestational age at 30.3 ± 3.0 wk and 7 intrauterine growth-restricted pregnancies at 26.5 ± 1.0 wk gestation to investigate placental transport in vivo. Umbilical venous samples were obtained at the time of in utero fetal blood sampling at 450± 74 sec from the bolus injection. In normal pregnancies the fetal/maternal (F/M) enrichment ratios for leucine (0.76 ± 0.06) and phenylalanine (0.77 ± 0.06) were higher (P < 0.01) than the F/M ratios for glycine (0.18 ± 0.04) and proline (0.22 ± 0.02). This suggests that these two essential amino acids rapidly cross the placenta in vivo. Compared with the essentials, both glycine and proline had significantly lower F/M enrichment ratios, which were not different from each other. The results support the hypothesis that amino acids with high affinity for exchange transporters cross the placenta most rapidly. In intrauterine growth-restricted pregnancies, the F/M enrichment ratio was significantly lower (P < 0.01) for l-[1-13C]leucine (0.76 ± 0.06 vs. 0.48 ± 0.07) and for l-[1-13C]phenylalanine (0.77 ± 0.06 vs. 0.46 ± 0.07) compared with appropriate for gestational age pregnancies reflecting impaired transplacental flux. The F/M enrichment ratio did not differ for[ 1-13C]glycine (0.18 ± 0.04 vs. 0.17 ± 0.03), and l-[1-13C]proline (0.22 ± 0.02 vs. 0.18 ± 0.04).
The Complete Normalization of the Adrenocortical Function as the Criterion of Cure after Transsphenoidal Surgery for Cushing’s Disease
Authors: Estrada Javier , García-Uría José , Lamas Cristina , Alfaro José , Lucas Tomás , Diez Santiago , Salto Luis , Barceló Balbino
Published: January 2014

Transsphenoidal microsurgery is the standard treatment for patients with Cushing’s disease. However, there is general lack of agreement regarding the definition of cure.

We studied 58 patients with corrected hypercortisolism after transsphenoidal surgery for Cushing’s disease. Plasma and urinary cortisol levels were measured after surgery. After the postsurgical hypocortisolism stage (or periodically in patients without hypocortisolism), urinary free cortisol, plasma cortisol at 0800 h and 2300 h, morning cortisol after 1 mg dexamethasone, and cortisol response to insulin-induced hypoglycemia were performed. Patients were classified in 3 groups: group I, patients with transient hypocortisolism and normal hypothalamus-pituitary-adrenal axis afterwards; group II, patients with transient hypocortisolism and abnormalities in the circadian rhythm or the stress response afterwards; and group III, patients without postoperative hypocortisolism.

Thirty-three patients were included in group I, 8 in group II, and 17 in group III. Groups I and II were similar in postsurgical plasma cortisol (46.9 ± 30.3 vs. 60.7 ± 38.6 nm) and mean follow-up (69.8 vs. 68.8 months) but were significantly different in their recurrence rate (3.4% vs. 50%, P < 0.001). Patients in group III had normal postsurgical plasma and urinary cortisol but persistent abnormalities in circadian rhythm and stress response. After a mean follow-up of 39.1 months, their recurrence rate was similar to that of group II (64.7% vs. 50%).

The complete normalization of the adrenocortical function, which is always preceded by postsurgical hypocortisolism, is associated with a very low recurrence risk and should be considered, in our opinion, the main criterion of surgical cure in Cushing’s disease.
The Effect of the Gly16Arg Polymorphism of theβ 2-Adrenergic Receptor Gene on Plasma Free Fatty Acid Levels Is Modulated by Physical Activity
Authors: Meirhaeghe Aline , Luan Jian’an , Selberg-Franks Paul , Hennings Susie , Mitchell Jo , Halsall David , O’Rahilly Stephen , Wareham Nicholas J.
Published: January 2014

The lipolytic effects of catecholamines are mediated through members of the β2-adrenergic receptor (BAR-2) family. Previous studies have suggested that genetic variants in the BAR-2 gene may be associated with obesity in some populations. To our knowledge, no studies have directly examined the effects of this polymorphism on circulating nonesterified fatty acid (NEFA) levels. To explore this issue further, a cohort of 604 Caucasian individuals (aged 40–65 yr) was genotyped for a common polymorphism in the BAR-2 gene (Gly16Arg), and the relationships between genotype, body mass index (BMI), NEFA, and lipid levels were examined. Women bearing the Arg16 allele had higher BMI values (P < 0.01) than Gly16Gly women. Women carriers of the Arg16Arg genotype had lower fasting plasma NEFAs (P < 0.01) and greater suppression of NEFAs (P < 0.01) after an oral glucose load than women bearing the Gly16 allele. In multivariate analysis after adjustment for age, sex, and smoking status, the interaction between the BAR-2 genotype and BMI in determining fasting NEFA concentrations was statistically significant (P < 0.05). The availability of objective measures of total energy expenditure in this population permitted the further examination of interactions, particularly that between genotype and physical activity. In the population as a whole, after adjustment for confounding by age, smoking, and BMI, the effect of the Arg16Arg genotype on the suppression of NEFA levels was modified by physical activity level (P for interaction <0.05). These data suggest the existence in this population of a gene-physical activity interaction on NEFA levels.
Action of Chicken II GnRH on the Human Placenta1
Authors: Siler-Khodr Theresa M. , Grayson Marcia
Published: January 2014

The stability, receptor binding, bioactivity, and production of chicken II GnRH and its analogs in the human placenta were studied. Both chicken II and mammalian GnRH are rapidly degraded by placental enzymes, yet the chicken II isoform is six times more stable. Analogs of chicken II GnRH were synthesized, and their stability in the presence of placental enzymes was tested. The d-Arg(6)-chicken II GnRH-aza-Gly(10)-NH2 analog was found to be resistant to enzymatic degradation. The placental receptor binding activity of the chicken II GnRH analogs and chicken II GnRH was compared with that of mammalian GnRH and its analogs. Because d-Arg(6)-chicken II GnRH-aza-Gly(10)-NH2 had the highest affinity for the placental receptor and was stable in placental extracts, the bioactivity of this analog on the regulation of placental human CG (hCG) release was compared with that for mammalian and chicken II GnRH using a human term placental explant culture system. This chicken II GnRH analog effected a stimulation of hCG at the lowest concentration studied (250 nm). With extended exposure and/or higher concentrations of this chicken II GnRH analog, the release of hCG from human placental explants was inhibited. Using a placental explant perifusion system and a highly specific RIA for chicken II GnRH, the pulsatile release of chicken II GnRH from the early human placenta was demonstrated.

These studies are the first to demonstrate bioactivity of a second form of GnRH in a human tissue and to identify the pulsatile release of chicken II GnRH from a human tissue. These data led us to propose that chicken II GnRH and its synthetic analogs may be potent ligands for hormone regulation during pregnancy.
Estrogen Receptor β, But Not Estrogen Receptor α, Is Present in the Vascular Endothelium of the Human and Nonhuman Primate Endometrium1
Authors: Critchley Hilary O. D. , Brenner Robert M. , Henderson Teresa A. , Williams Karin , Nayak Nihar R. , Slayden Ov D. , Millar Michael R. , Saunders Philippa T. K.
Published: January 2014

Estrogen action is dependent upon the presence of specific ligand-activated receptors in target tissues. The aim of the present experiments was to compare the spatial and temporal pattern of expression of estrogen receptor β (ERβ) with that of ERα in full thickness endometrial samples (from the superficial to the basal zone) obtained from both women and rhesus macaques. Immunohistochemical localization with specific antibodies revealed that ERα and ERβ were both expressed in nuclei of the glands and stroma. Consistent with previous studies, expression of ERα declined in the glands and stroma of the functionalis during the secretory phase. The luminal epithelium also displayed positive immunoreactivity for ERβ. Expression of ERβ declined in glandular cell nuclei, but not stroma, within the functionalis during the late secretory phase. Levels of expression of ERα and ERβ in all cellular compartments remained unchanged in the basalis. Both receptor subtypes were detected on Western blots using proteins extracted from uterine samples obtained throughout the menstrual cycle.

There was a striking contrast between the pattern of expression of ERα and ERβ in the vascular endothelium and the perivascular cells surrounding endometrial blood vessels; only ERβ was present in the endothelial cell population, although both forms of ER were expressed in perivascular cells. We conclude that estrogen action(s) within the vascular endothelium in the endometrium may be mediated via direct binding to the ERβ isoform and that these cells could therefore be a target for agonists or antagonists that selectively target the β form of the ER.
Somatic Mutation and Germline Variants of MINPP1, a Phosphatase Gene Located in Proximity to PTEN on 10q23.3, in Follicular Thyroid Carcinomas1
Authors: Gimm Oliver , Chi Hongbo , Dahia Patricia L. M. , Perren Aurel , Hinze Raoul , Komminoth Paul , Dralle Henning , Reynolds Paul R. , Eng Charis
Published: January 2014

Various genes have been identified to play a role in the pathogenesis of follicular thyroid tumors. Cowden syndrome is the only known familial syndrome with an increased risk of both follicular thyroid adenoma (FA) and carcinoma (FTC). Germline mutations in the tumor suppressor gene PTEN, which encodes a dual-specificity phosphatase, have been found in up to 80% of patients with Cowden syndrome suggesting a role of PTEN in the pathogenesis of follicular thyroid tumors. Although somatic intragenic mutations in PTEN, which maps to 10q23.3, are rarely found in follicular tumors, loss of heterozygosity (LOH) of markers within 10q22–24 occurs in about 25%. Recently, another phosphatase gene, MINPP1, has been localized to 10q23.3. MINPP1 has the ability to remove 3-phosphate from inositol phosphate substrates, a function that overlaps that of PTEN. Because of this overlapping function with PTEN and the physical location of MINPP1 to a region with frequent LOH in follicular thyroid tumors, we considered it to be an excellent candidate gene that could contribute to the pathogenesis of follicular thyroid tumors. We analyzed DNA from tumor and corresponding normal tissue from 23 patients with FA and 15 patients with FTC for LOH and mutations at the MINPP1 locus. LOH was identified in four malignant and three benign tumors. One of these FTCs with LOH was found to harbor a somatic c.122C > T or S41L mutation. We also found two germline sequence variants, c.809A > G (Q270R) and IVS3 + 34T > A. The c.809A > G variant was found in only one patient with FA but not in patients with FTC or normal controls. More interestingly, IVS3 + 34T > A was found in about 15% of FA cases and normal controls but not in patients with FTC. These results suggest a role for MINPP1 in the pathogenesis of at least a subset of malignant follicular thyroid tumors, and MINPP1 might act as a low penetrance predisposition allele for FTC.
Branched Chain Amino Acids Activate Messenger Ribonucleic Acid Translation Regulatory Proteins in Human Skeletal Muscle, and Glucocorticoids Blunt This Action1
Authors: Liu Zhenqi , Jahn Linda A. , Long Wen , Fryburg David A. , Wei Liping , Barrett Eugene J.
Published: January 2014

Branched chain amino acids (BCAA) are particularly effective anabolic agents. Recent in vitro studies suggest that amino acids, particularly leucine, activate a signaling pathway that enhances messenger ribonucleic acid translation and protein synthesis. The physiological relevance of these findings to normal human physiology is uncertain. We examined the effects of BCAA on the phosphorylation of eukaryotic initiation factor 4E-binding protein 1 (eIF4E-BP1) and ribosomal protein S6 kinase (p70S6K) in skeletal muscle of seven healthy volunteers. We simultaneously examined whether BCAA affect urinary nitrogen excretion and forearm skeletal muscle protein turnover and whether the catabolic action of glucocorticoids could be mediated in part by inhibition of the action of BCAA on the protein synthetic apparatus.

BCAA infusion decreased urinary nitrogen excretion (P < 0.02), whole body phenylalanine flux (P < 0.02), plasma phenylalanine concentration (P < 0.001), and improved forearm phenylalanine balance (P = 0.03). BCAA also increased the phosphorylation of both eIF4E-BP1 (P < 0.02) and p70S6K (P < 0.03), consistent with an action to activate the protein synthetic apparatus. Dexamethasone increased plasma phenylalanine concentration (P < 0.001), prevented the BCAA-induced anabolic shift in forearm protein balance, and inhibited their action on the phosphorylation of p70S6K. We conclude that in human skeletal muscle BCAA act directly as nutrient signals to activate messenger ribonucleic acid translation and potentiate protein synthesis. Glucocorticoids interfere with this action, and that may be part of the mechanism by which they promote net protein catabolism in muscle.
The Influence of Aging and Sex Hormones on Expression of Growth Hormone-Releasing Hormone in the Human Immune System1
Authors: Khorram O. , Garthwaite M. , Golos T.
Published: January 2014

GHRH is a neuropeptide that has also been localized to the immune system. The physiological function of GHRH in the immune system has not been elucidated. This study was conducted to determine whether immune GHRH expression is altered in certain pathological states, such as immune cell tumors, and whether gender, aging, and alterations in the sex steroid milieu influence the expression of this peptide in immune cells.

Using double color flow cytometry, GHRH protein was found to be expressed in less than 2% of peripheral blood mononuclear cells (PBMC). Monocytes and B and T cells all expressed GHRH protein, although a greater percentage of T cells compared with B cells and monocytes expressed GHRH (5- to 7-fold). Semiquantitative RT-PCR was used to quantify GHRH messenger ribonucleic acid (mRNA) in PBMC and several immune cell-derived tumors. PBMC and granulocytes expressed low levels of GHRH mRNA with relatively higher levels of expression in monocytes. The tumor cell lines CEMX 174 (B/T cells), HUT 78 (T cells), WIL2-N (B cells), U937 (monocytes/macrophages), and JM 1 (pre-B cell lymphoma) all showed greater expression of GHRH mRNA relative to PBMC. However, two cell lines, CCRF-SB, a B lymphoblastoid cell line, and HL-60, a promyelocytic cell line, expressed GHRH mRNA at similar levels as PBMC.

A significant decrease in the percentage of lymphocytes (CD45+ cells) expressing GHRH protein was found in age-advanced men and women compared with young men and women. This decline was noted in B cells (CD20+) and monocytes (CD14+), but not in T cells (CD3+). GHRH mRNA expression in PBMC derived from postmenopausal women was lower than that from premenopausal women. However, no differences in PBMC GHRH mRNA expression were found in young and old men. Although in older men there were fewer peripheral lymphocytes that express GHRH protein, these cells secreted significantly more GHRH in vitro than cells from postmenopausal women with no hormone replacement therapy (HRT), but similar levels as cells from women receiving HRT. PBMC from women receiving HRT secreted more GHRH in vitro than cells from women receiving no hormone replacement.

This study demonstrates that the expression of immune GHRH is dynamic, and therefore likely to be regulated. Increased expression of GHRH in certain immune tumors suggests that GHRH may be mitogenic under certain conditions and therefore play a role in the pathogenesis of select immune cell tumors. Collectively, these results suggest a role for GHRH as a local immune modulator and in the pathophysiology of immunosenescence and immune cell tumors.
Luteal Angiogenesis: Prevention and Intervention by Treatment with Vascular Endothelial Growth Factor TrapA401
Authors: Wulff Christine , Wilson Helen , Rudge John S. , Wiegand Stanley J. , Lunn Stephen F. , Fraser Hamish M.
Published: January 2014

The possibility of stimulating or inhibiting paracrine factors regulating angiogenesis may lead to new approaches for the treatment of pathological conditions of the female reproductive tract. We examined the effects of a clinical candidate, a soluble truncated form of the Flt-1 receptor, vascular endothelial growth factor trapA40 (VEGF trap), in a primate model to determine its ability to prevent the onset of luteal angiogenesis or intervene with the on-going process. Marmosets were treated from the day of ovulation until luteal day 3 (prevention regimen) or on luteal day 3 for 1 day (intervention regimen). Effects of VEGF inhibition were studied by obtaining a proliferation index using bromodeoxyuridine incorporation, quantifying endothelial cell area using CD31, and assessing luteal function by plasma progesterone. After both treatments, intense luteal endothelial proliferation was suppressed, a concomitant decrease in endothelial cell area confirmed the inhibition of vascular development, and a marked fall in plasma progesterone levels showed that luteal function was compromised. In situ hybridization was used to localize and quantify compensatory effects on the expression of angiogenic genes. VEGF messenger ribonucleic acid (mRNA) expression in luteal cells was increased, whereas expression of its receptor, Flt, was decreased. Inhibition of VEGF resulted in localized increased expression of angiopoietin-2 mRNA and its receptor, Tie-2.

The results show that the VEGF trap can prevent luteal angiogenesis and inhibit the established process with resultant suppression of luteal function. Luteal Flt mRNA expression is dependent upon VEGF, and VEGF inhibition results in abortive increases in expression of VEGF, angiopoietin-2, and Tie-2.