bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Bioactive Luteinizing Hormone Levels and Bio/Immuno Ratio in Women with Hyperthecosis of the Ovaries: Possible Role of Hyperinsulinemia1
Authors: Nagamani Manubai , Osuampke Collins , Kelver Mae Ellen
Published: January 2014

Unlike women with polycystic ovarian disease, women with hyperthecosis have normal or low immunoactive LH levels. They have severe insulin resistance with marked hyperinsulinemia. Bioactive LH levels have not been studied in these women. The purpose of this study was to investigate 1) whether there is an increase in bioactive LH levels in women with hyperthecosis of the ovaries and 2) whether hyperinsulinemia has an effect on LH secretion. Six women with hyperthecosis of the ovaries confirmed by histological examination were included in the study. Six normal women in the midproliferative phase of the cycle served as controls. All women were admitted to the Clinical Research Center at 0800 h, and blood samples were obtained every 15 min for 6 h. All samples were assayed for LH by RIA and bioassay. The PC Pulsar Program was used for pulse analysis of LH secretion. Patients with hyperthecosis had significantly higher (P < 0.002) bioactive LH levels (66.9 ± 13 mIU/mL) than controls (29.3 ± 6 mIU/mL). Immunoactive LH levels in hyperthecosis were not significantly different from those in control women. Significantly higher bio/immuno LH ratios (P < 0.001) were observed in women with hyperthecosis (6.2 ± 0.9) than in normal control women (2.4 ± 0.5). There was a significant positive correlation between insulin levels and the bio/immuno ratio of LH. Pulse amplitude and interpulse intervals for immunoactive LH in hyperthecosis patients were similar to those in control women. The pulse amplitude of bioactive LH was significantly higher (P < 0.01) in women with hyperthecosis compared to that in normal controls. Hyperinsulinemia induced during LH sampling resulted in increased bioactive LH levels with no change in immunoactive LH. These results indicate that 1) women with hyperthecosis of the ovaries have increased secretion of biologically active LH, and 2) hyperinsulinemia may enhance the secretion of the biologically active form of LH.
Estrogen Activity and Novel Tissue Selectivity ofΔ 8,9-Dehydroestrone Sulfate in Postmenopausal Women
Authors: Baracat E. , Haidar M. , López F. J. , Pickar J. , Dey M. , Negro-Vilar A.
Published: January 2014

Recent basic and clinical advances have consolidated the concept of tissue-selective estrogens, i.e. molecules that express different degrees of partial agonist, full agonist or antagonist activity in different tissues or cells.Δ 8,9-Dehydroestrone sulfate (Δ8,9-DHES) is a conjugated estrogen and a component of conjugated equine estrogens (CEE). It is metabolized in the human in at least a 1:1 ratio to its 17β form, 17β-Δ8,9-DHES. To evaluate its activity in different clinical and biochemical parameters, a clinical research study was conducted with Δ8,9-DHES and estrone sulfate as a comparator in postmenopausal women. Δ8,9-DHES was given orally at a daily dose of 0.125 mg for 12 weeks in a group of 10 women. Two additional groups of women received either estrone sulfate alone (1.25 mg/day) or the combination of Δ8,9-DHES and estrone sulfate at the previously specified doses. A significant and consistent suppression of hot flushes (number, severity, and total score) was observed with Δ8,9-DHES, reaching more than 95% suppression in all parameters of vasomotor symptoms. This level of activity was equal to that obtained with the much higher dose of estrone sulfate, and it was sustained for the duration of the treatment period (12 weeks). Measurements of a bone resorption marker, i.e. urinary excretion of N-telopeptide, demonstrated that Δ8,9-DHES at 8 weeks produced a degree of suppression (40%) similar to that observed with the higher dose of estrone sulfate. Gonadotropin secretion (FSH and LH) was significantly suppressed in women receiving Δ8,9-DHES, similar to that observed with estrone sulfate alone or with the combination of the two. Other parameters, such as total cholesterol, low density lipoprotein cholesterol and high density lipoprotein cholesterol were not modified significantly, whereas serum globulins (sex hormone-binding globulin and corticosteroid-binding globulin) showed only marginal increases after Δ8,9-DHES administration.

Taken together with preclinical data, it is found thatΔ 8,9-DHES is an active estrogen with a distinct pharmacological profile that results in significant clinical activity in vasomotor, neuroendocrine (gonadotropin and PRL) and bone preservation parameters, whereas displaying little or no efficacy, at the dose tested, on other peripheral parameters normally affected by estrogens. Collectively, this information supports the concept thatΔ 8,9-DHES is an integral component of CEE, with distinct tissue selectivity contributing to the CEE’s overall clinical activity, and places this estrogen as a distinct member of a novel class of centrally active molecules with unique peripheral tissue selectivity.
Extrapituitary Parasellar Microadenoma in Cushing’s Disease
Authors: Pluta Ryszard M. , Nieman Lynnette , Doppman John L. , Watson Joseph C. , Tresser Nancy , Katz David A. , Oldfield Edward H.
Published: January 2014

Negative sellar exploration (despite the results of endocrine evaluation indicating Cushing’s disease), the high incidence of failure of total hypophysectomy, and remission of Cushing’s syndrome after unsuccessful hypophysectomy and sellar irradiation suggest that the etiology of refractory Cushing’s disease, in some patients, lies near the sella but not in the pituitary gland. We present 5 patients, out of 626 who received surgery for Cushing’s disease, in whom an ACTH-secreting extrapituitary parasellar adenoma was identified: 2 after unsuccessful total hypophysectomy for the treatment of refractory Cushing’s disease, 2 after unsuccessful hemihypophysectomy (the first, 2 yr before treatment at the NIH for Nelson’s syndrome; and the second, with recurrent Cushing’s disease 5 yr after negative transsphenoidal exploration), and 1 with a preoperative diagnosis of an intraclival microadenoma, which was cured by resection of the tumor. In all cases, an extrapituitary parasellar microadenoma was confirmed unequivocally as the cause of the disease, by negative pathology of the resected pituitary gland (patients 1, 2, 3, and 5), and/or the remission of the disease after selective resection of the extrasellar adenoma (patients 3, 4, and 5). Three of 5 patients had a partial empty sella. These patients support the thesis that ACTH-secreting tumors can arise exclusively from remnants of Rathke’s pouch, rather than from the adenohypophysis (anterior lobe or pars tuberalis of the pituitary gland) and can be a cause of Cushing’s disease. In the sixth presented case, an extrapituitary tumor was suspected at surgery after negative pituitary exploration, but serial sections of the hemihypophysectomy specimen revealed a microscopic focus of tumor at the margin of the resected gland. This case demonstrates the importance of negative pituitary histology to establish the presence of an extrapituitary parasellar tumor as an exclusive source of ACTH, and it supports the value of clinical outcome to establish the diagnosis with selective adenomectomy of an extrapituitary parasellar tumor. In patients with negative pituitary magnetic resonance imaging, especially in the presence of a partial empty sella, the diagnostic and surgical approach in Cushing’s disease should consider the identification and resection of extrapituitary parasellar adenoma, which can avoid total hypophysectomy, as was possible in 3 of our 5 patients.
Lactate and Glycerol Release from Subcutaneous Adipose Tissue in Black and White Lean Men1
Authors: van der Merwe Maria-Terésa , Jansson Per-Anders , Crowther Nigel J. , Boyd Ivan H. , Gray I. Peter , Joffe Barry I. , Lönnroth Peter N.
Published: January 2014

To measure interstitial glycerol and lactate production from the sc adipose tissue of two regions in nine black and nine white lean men, sc microdialysis was performed in combination with adipose tissue blood flow rates measured with 133Xe clearance.

In the postabsorptive state, the plasma glucose and insulin levels of the black men and white men were similar. The black men had higher plasma free fatty acids (825 ± 97 vs. 439 ± 58 μmol/L; P < 0.005), glycerol (99.5 ± 5.1 vs. 54.1 ± 3.3 μmol/L; P< 0.0001), and lactate (1056 ± 95 vs. 729 ± 45 μmol/L; P < 0.01). Interstitial glycerol concentrations in the black and white men were 227 vs. 163 μmol/L (P < 0.01) and 230 vs. 162 μmol/L (P < 0.05) in the abdominal and femoral regions. The adipose tissue blood flow rate was higher in the black men in the abdominal (7.9 ± 0.9 vs. 3.1± 0.5 mL/100 g·min; P < 0.01) and femoral area (5.2 ± 0.6 vs. 2.8 ± 0.3; P < 0.01). Interstitial lactate concentrations in black and white men were 1976 vs. 1364 μmol/L (P < 0.004) and 1953 vs. 1321μ mol/L (P < 0.004) in the abdominal and femoral regions, respectively. Glycerol release was higher in black men vs. white men for abdominal (0.21 ± 0.02 vs. 0.14 ± 0.02 μmol/100 g·min; P < 0.02) and femoral (0.22 ± 0.02 vs. 0.15 ± 0.01; P < 0.05) areas.

Postprandially, black men had higher plasma glucose levels [1 h, 9.6 ± 0.4 vs. 8.2 ± 0.5 mmol/L (P < 0.05); 2 h, 8.9 ± 0.4 vs. 7.2 ± 0.4 mmol/L (P < 0.01)], but lower plasma insulin levels [1 h, 173 ± 13 vs. 264 ± 48 pmol/L (P < 0.05); 2 h, 136 ± 20 vs. 209 ± 34 pmol/L (P < 0.05)]. Plasma free fatty acid, lactate, and glycerol levels remained higher in the black men. After 1 h, lactate release was higher in the black men vs. that in the white men for abdominal (20.5 ± 1.6 vs. 14.7 ± 2.5 μmol/100 g·min; P < 0.05) and femoral (15.6 ± 1.1 vs. 12.1 ± 1.8; P < 0.03) areas.

We conclude that the black men, who are relatively insulinopenic postprandially, have a brisker lipolysis and also release more lactate from sc fat tissue than white men. These differences in adipose tissue metabolism may be related to differences in the lipid profiles and glucose metabolism previously documented in these ethnic groups.
A Longitudinal Study of Vasopressin Cell Antibodies, Posterior Pituitary Function, and Magnetic Resonance Imaging Evaluations in Subclinical Autoimmune Central Diabetes Insipidus
Authors: De Bellis A. , Colao A. , Di Salle F. , Muccitelli V. I. , Iorio S. , Perrino S. , Pivonello R. , Coronella C. , Bizzarro A. , Lombardi G. , Bellastella A.
Published: January 2014

Cytoplasmic autoantibodies to vasopressin-cells (AVPcAb) have been detected not only in patients with overt central diabetes insipidus (CDI), but also in patients with endocrine autoimmune diseases without CDI. This suggests that complete CDI can be preceded by a preclinical stage. Among 878 patients with endocrine autoimmune diseases without CDI, 9 patients found to be AVPcAb positive and 139 AVPcAb-negative controls were enrolled in this open prospective study. They were evaluated for AVPcAb and posterior pituitary function at least yearly for about 4 yr (range, 37–48 months); during this span, magnetic resonance imaging (MRI) of posterior pituitary and stalk was performed only in the AVPcAb-positive patients. Five of the 9 AVPcAb-positive patients had normal posterior pituitary function at study entry. They were AVPcAb positive throughout the follow-up period. At later stages of the study, 3 of them developed partial CDI, and 1 developed complete CDI. The remaining 4 patients showed impaired response to the water deprivation test at study entry and were diagnosed as having partial CDI. Two of them agreed to receive desmopressin replacement for 1 yr. After this treatment, the patients became negative for AVPcAb and displayed normal posterior pituitary function until the end of the follow-up. Conversely, the 2 untreated patients with partial CDI remained AVPcAb positive. One of them developed overt CDI. None of the controls became AVPcAb positive or developed CDI. The normal hyperintense MRI signal of the posterior pituitary, present at study entry, persisted subsequently in all 9 AVPcAb-positive patients, including those developing overt CDI, only disappearing in the late phase of complete CDI. In asymptomatic subjects, the monitoring of AVPcAb, but not MRI, seems to be useful to predict a progression toward partial/overt CDI. Early desmopressin therapy in patients with partial CDI could interrupt or delay the autoimmune damage and the progression toward clinically overt CDI.
Pituitary Somatotroph Adenoma Producing Growth Hormone (GH)-Releasing Hormone (GHRH) with an Elevated Plasma GHRH Concentration: A Model Case for Autocrine and Paracrine Regulation of GH Secretion by GHRH1
Authors: Matsuno Akira , Katakami Hideki , Sanno Naoko , Ogino Yoshio , Osamura R. Yoshiyuki , Matsukura Shigeru , Shimizu Naokata , Nagashima Tadashi
Published: January 2014

An acromegalic patient with a pituitary somatotroph adenoma associated with an extremely elevated plasma GHRH concentration is presented. The preoperatively high concentration of plasma GHRH returned to the normal level after successful removal of the adenoma. GHRH production and GHRH gene expression were confirmed in the adenoma by studies including immunohistochemistry and in situ hybridization. Expression of GHRH receptor messenger ribonucleic acid was verified by in situ hybridization. Immunohistochemical double staining for GH and GHRH revealed their colocalization in single adenoma cells. These findings confirmed the autocrine or paracrine regulation of GH production by endogenous GHRH from the adenoma cells. GHRH synthesis in the pituitary gland has recently been demonstrated, however, there have been no previous reports of a GHRH-producing pituitary somatotroph adenoma associated with an elevated plasma GHRH concentration. The existence of this GHRH-producing adenoma suggests a possible role of locally generated GHRH in the progression of somatotroph adenomas, i.e. the monoclonally established somatotroph adenomas develop further under the influence of locally produced GHRH. The demonstration of GHRH production by this somatotroph adenoma is of importance in clarifying the autocrine or paracrine regulation of GH production and the progression of human somatotroph adenomas.
The Primate Adrenal Zona Reticularis is Defined by Expression of Cytochrome b5, 17α-hydroxylase/17,20-lyase Cytochrome P450 (P450c17) and NADPH-Cytochrome P450 Reductase (reductase) but not 3β-Hydroxysteroid Dehydrogenase/Δ5-4 Isomerase (3β-HSD)
Authors: Mapes Samantha , Corbin C. Jo , Tarantal Alice , Conley Alan
Published: January 2014

Biochemical studies suggest that 17,20-lyase activity, and thus efficient synthesis of androgens by human P450c17, requires both reductase and the accessory protein cytochrome b5. Since the human and primate zona reticularis (ZR) secrete androgens, the expression of these proteins, and of 3β-HSD, was investigated by immunocytochemistry in the adrenal cortex of the mature rhesus macaque. Cytochrome b5 expression was restricted to the cells of the ZR which appeared deficient in 3β-HSD. However, both P450c17 and reductase were evident throughout the zona fasciculata. These data provide essential evidence in support of a functional role for cytochrome b5 in the regional control of 17α-hydroxylase and 17,20-lyase activities of P450c17 and thereby adrenal C19 steroid secretion by the primate adrenal gland.
The A19G Polymorphism in the 5′ Untranslated Region of the Human Obese Gene Does Not Affect Leptin Levels in Severely Obese Patients
Authors: Lucantoni Rossana , Ponti Emanuela , Berselli Maria Elisa , Savia Giulio , Minocci Alessandro , Calò Giovanna , De Medici Clotilde , Liuzzi Antonio , Di Blasio Anna Maria
Published: January 2014

Recently, the presence of different polymorphisms in the regulatory region of the ob gene has been associated with variations in leptin levels. However, the results of these studies are still contradictory. The aim of the present investigation was to evaluate the presence of the A19G polymorphism in an Italian population of obese patients and to verify its association with leptin levels and anthropometric, metabolic, and clinical parameters. Two hundred five obese patients [body mass index (BMI) > 36 kg/m2; 135 women and 70 men; mean age, 46.9 ± 14.23 yr] were screened for presence of the polymorphism; 61 normal-weight controls (mean BMI, 21.05 kg/m2; 53 women, 8 men) were also screened to compare polymorphism frequency. For obese patients, BMI, waist-to-hip ratio, resting energy expenditure, body composition, fasting leptin, total cholesterol, high-density lipoproteins, triglycerides, and caloric intake were determined. Genotype frequencies in obese and control subjects were compared using the contingency table chi-square test; in obese subjects an ANOVA was performed to evaluate association between the polymorphism and several clinical parameters. No significant differences in genotype distribution between control and obese subjects were found. No significant correlations were found between this polymorphism and serum leptin levels and the other parameters considered. These findings confirm the results obtained in both a Finnish and a French population; taken together, these observations might rule out a significant role for the A19->G polymorphism in the regulation of leptin levels and other clinical, anthropometric, and metabolic parameters.
Estrogen Priming Effect on Growth Hormone (GH) Provocative Test: A Useful Tool for the Diagnosis of GH Deficiency1
Authors: MartÍnez Alicia S. , Domené Horacio M. , Ropelato M. Gabriela , Jasper Héctor G. , Pennisi Patricia A. , Escobar MarÍa E. , Heinrich Juan J.
Published: January 2014

We have studied the effect of estradiol (E2)on the GH-insulin-like growth factor (GH-IGF) axis in 15 prepubertal GH deficiency (GHD) children and 44 prepubertal or early pubertal children with idiopathic short stature (SS). All of them received a daily dose of micronized E2 (1 or 2 mg) or placebo, for 3 days, before a sequential arginine-clonidine test. In SS children, GH maximal responses were 17.8 ± 10.9 on placebo and 27.9 ± 14.5μ g/L on estrogen (P < 0.0001). The lower 95% confidence limits for GH maximal response changed from 3.7 μg/L (without E2) to 8.3 μg/L (on E2). In GHD children, no significant stimulatory effect of estrogen on GH levels was observed. After placebo, a cut-off limit of 3.7 μg/L (the lower 95% confidence interval limit) resulted in 73% sensitivity, 95% specificity, and an overall 90% diagnostic efficiency. After E2, a cut-off limit of 8.3 μg/L resulted in a sensitivity of 87%, a specificity of 98%, and a diagnostic efficiency of 95%.

After placebo, 68% of SS showed normal IGF-I levels, and the mean did not change on E2 (13.7 ± 6.3 vs. 14.3 ± 6.8 nmol/L, not significant). In 93% of SS, IGF binding protein (IGFBP)-3 levels were normal during placebo. On E2, mean IGFBP-3 did not change (2.63 ± 0.70 vs. 2.70 ± 0.70 mg/L, not significant). In 14 of 15 GHD patients, IGF-I values were below normal on placebo, and the mean of the group did not change after E2. During placebo, 13 of 15 GHD children presented low IGFBP-3 values. During E2, there was a small significant increase in IGFBP-3 values (1.06 ± 0.58 vs. 1.20 ± 0.69 mg/L, P < 0.02). The highest diagnostic efficiencies for IGF-I and IGFBP-3 were observed during placebo (75% and 91%, respectively).

We conclude that GH stimulation tests after E2 priming had the highest diagnostic efficiency. Our findings suggest that the effect of estrogen priming on GH stimulated levels, by reducing the number of false nonresponders, might be useful to better discriminate between normal and abnormal GH status in SS children.
Regulation of Aromatase Expression in Human Ovarian Surface Epithelial Cells1
Authors: Okubo Tomoharu , Mok Samuel C. , Chen Shiuan
Published: January 2014

Ovarian cancer originates mainly from surface epithelial cells, which are potential targets of estrogen action. Using immunohistochemistry and RT-PCR analysis, aromatase (estrogen synthetase) can be detected in human ovarian surface epithelial tumors. In this study, we functionally characterized the aromatase expressed in a primary cell culture, normal human ovarian surface epithelial (HOSE) 17. The apparent Km and Vmax values were determined to be 5.8 ± 0.5 nm, and 0.3 ± 0.0 pmol/mg·h, respectively. The aromatase activity in HOSE 17 cells can be induced effectively by phorbol esters and forskolin, suggesting that estrogen biosynthesis in HOSE 17 cells is mainly regulated through protein kinase C- and protein kinase A-mediated mechanisms. Exon I-specific RT-PCR revealed that phorbol esters predominantly up-regulated promoter II. Whereas forskolin treatment increased exon I.3A-containing messenger RNA, the aromatase activity remained low in the cells treated with this agent. In vitro transcription/translation analysis using plasmids containing T7 promoter and the human snail gene (SnaH) as a reporter capped with different untranslated exon Is revealed that exon PII-containing transcripts were translated more effectively than exon I.3-containing transcripts. These findings explain why aromatase activity is higher in cells with the PII-containing transcripts than is cells with the I.3-containing transcripts. Our results indicate that aromatase is functionally expressed in human ovarian surface epithelial cells and its expression is regulated at both the transcriptional and translational levels.
The Localization of the Functional Glucocorticoid Receptor α in Human Bone
Authors: Abu Emmanuel O. , Horner A. , Kusec V. , Triffitt J. T. , Compston J. E.
Published: January 2014

Glucocorticoids have well-documented effects on the skeleton, although their mechanism of action is still poorly understood. The actions of glucocorticoids on bone cells are mediated, in part, directly via specific receptors. The presence of these receptors has been demonstrated in both rodent and human osteoblastic cells in vitro, but their presence in human bone in vivo has not been reported.

In this study, we have used specific affinity purified polyclonal antibodies to the functional glucocorticoid receptor α (GRα) to investigate its expression in both developing and adult human bone using sections of neonatal rib, calvarial, and vertebral bones, tibial growth plates from adolescents, and iliac crest biopsies from adults who were to undergo liver transplantation.

In the tibial growth plates, GRα was predominantly expressed in the hypertrophic chondrocytes within the cartilage. In the primary spongiosa, the receptor was highly expressed by osteoblasts at sites of bone modeling. Within the bone marrow, receptors were also detected in mononuclear cells and in endothelial cells of blood vessels. In the neonatal rib and vertebrae, GRα was widely distributed at sites of endochondral bone formation in resting, proliferating, mature, and hypertrophic chondrocytes. They were also highly expressed in osteoblasts at sites of bone modeling. At sites of intramembranous ossification in neonatal calvarial bone and rib periosteum, GRα was widely expressed in cells within the fibrous tissue and in osteoblasts at both the bone-forming surface and at modeling sites. In the iliac crests from adults, GRα was predominantly expressed in osteocytes. The receptors were not detected in osteoclasts.

Our results show for the first time the presence of the functional GRα in human bone in situ and suggest that the actions of glucocorticoids on bone may be mediated, in part, directly via the GR at different stages of life. The absence of receptor expression in osteoclasts also suggests that the effects of glucocorticoids on bone resorption may be mediated indirectly.
No Increased Insulin Sensitivity after a Single Intravenous Administration of a Recombinant Human Tumor Necrosis Factor Receptor: Fc Fusion Protein in Obese Insulin-Resistant Patients*
Authors: Paquot Nicolas , Castillo Manuel J. , Lefèbvre Pierre J. , Scheen Andre J.
Published: January 2014

Inhibition of tumor necrosis factor (TNF)-α results in a marked increase in insulin sensitivity in obese rodents. We investigated the influence of a TNF antagonist [Ro 45-2081, a recombinant fusion protein that consists of the soluble TNF-receptor (p55) linked to the Fc portion of human IgG1] on insulin sensitivity of patients with android obesity. Seven patients (five women and two men; mean ± sd age, 41 ± 4 yr; body mass index, 36.1 ± 4.7 kg/m2; waist to hip ratio, 0.99 ± 0.11) were studied (three patients with normal glucose tolerance and four patients with impaired glucose tolerance or mild diabetes; all were hyperinsulinemic). Each patient underwent two consecutive euglycemic hyperinsulinemic glucose-clamp tests: 48 h after injection of placebo and 48 h after a single iv injection of 50 mg Ro 45-2081. In both tests, steady-state plasma glucose and insulin levels were similar. Insulin-mediated glucose disposal (2.23 ± 0.74 vs. 2.38 ± 0.99 mg/kg−1·min−1) and glucose metabolic clearance rate (2.28 ± 0.85 vs. 2.48 ± 1.03 mL/kg−1·min−1) were similar after placebo and after the drug. Indirect calorimetry showed no difference in substrate oxidation rates between the two experimental conditions. In conclusion, under the conditions of this study, no improvement in insulin sensitivity was observed in obese insulin-resistant patients following a single iv administration of a recombinant TNF receptor: Fc fusion protein.
Respiratory Fitness, Free Living Physical Activity, and Cardiovascular Disease Risk in Older Individuals: A Doubly Labeled Water Study*
Authors: Dvorak Roman V. , Tchernof André , Starling Raymond D. , Ades Philip A. , DiPietro Loretta , Poehlman Eric T.
Published: January 2014

The objective of this study was to examine the importance of cardiorespiratory fitness vs. physical activity energy expenditure on selected cardiovascular disease risk factors in older individuals. One hundred and seventeen older individuals, 53 men (68 ± 9 yr) and 63 women (67 ± 7 yr), participated in the study. This cohort was divided into 4 groups: 1) high cardiorespiratory fitness and high physical activity, 2) high cardiorespiratory fitness and low physical activity, 3) low cardiorespiratory fitness and high physical activity, and 4) low cardiorespiratory fitness and low physical activity. Cardiorespiratory fitness (VO2max) was determined from a graded exercise test, physical activity energy expenditure was measured by doubly labeled water and indirect calorimetry, body composition was determined by dual energy x-ray absorptiometry, and dietary practices were determined by a 3-day recall. Cardiorespiratory fitness exerted greater effects on the cardiovascular disease risk profile than physical activity. That is, older individuals with higher levels of cardiorespiratory fitness, regardless of their physical activity levels, showed lower levels of fasting insulin (P < 0.01), triglycerides (P < 0.05), total cholesterol (P < 0.05), total to high density lipoprotein cholesterol ratio (P < 0.05), low density lipoprotein (P < 0.05), and lower waist circumference (P < 0.01). Moreover, individuals with a high cardiorespiratory fitness but low physical activity energy expenditure displayed a more favorable cardiovascular disease risk profile than individuals with low cardiorespiratory fitness and high physical activity energy expenditure. The results suggest that higher levels of cardiorespiratory fitness have greater cardioprotective effects than higher levels of free living physical activity in older individuals. Although these findings do not discount the health benefits of being physically active, it is possible that greater emphasis should be placed on aerobic exercise to increase cardiorespiratory fitness in the elderly.
Effect of Vitamin D Nutrition on Parathyroid Adenoma Weight: Pathogenetic and Clinical Implications*
Authors: Rao D. Sudhaker , Honasoge M. , Divine George W. , Phillips Evelyn R. , Lee Min W. , Ansari Mohammed R. , Talpos Gary B. , Parfitt A. Michael
Published: January 2014

In primary hyperparathyroidism, adenoma size is a major determinant of disease severity and manner of presentation, but the reason for the large variation in size (>100-fold) is unknown. One factor could be the level of vitamin D nutrition, because in India, where vitamin D deficiency is endemic, adenomas are larger and the disease more severe than in the U.S. Accordingly, we determined the relationship between vitamin D nutrition, as measured by serum levels of 25-hydroxyvitamin D (25OHD), and parathyroid gland weight, expressed on a logarithmic scale, in 148 U.S. patients with primary hyperparathyroidism.

A significant inverse relationship was found between log gland weight as dependent variable and serum 25OHD as independent variable (r =− 0.365; P < 0.0001). The only other influence on gland weight was a weak inverse correlation with age. Log gland weight as an independent variable was significantly related to adjusted calcium, PTH, and alkaline phosphatase (AP) as dependent variables. In 51 patients with serum 25OHD levels less than 15 ng/mL, gland weight, PTH, AP, and adjusted calcium were each significantly higher than in 97 patients with 25OHD levels of 15 ng/mL or more, but 1,25-dihydroxyvitamin D levels were similarly increased in both groups. In the former group the response of adjusted calcium to PTH was blunted, and the response of AP was enhanced, based on significant differences in regression slopes (P = 0.0004 and 0.0022, respectively).

Suboptimal vitamin D nutrition stimulates parathyroid adenoma growth by a mechanism unrelated to hypocalcemia or 1,25-dihydroxyvitamin D deficiency and reduces the calcemic response to PTH, so that a higher PTH level and more parathyroid cells are needed to raise the patient’s serum calcium to the level corresponding to the increased set-point that is characteristic of the disease. Improved vitamin D nutrition in the population is partly, perhaps largely, responsible for the historical changes in disease severity and manner of presentation that have occurred over the last 50 yr.
The Relationship between Glucose Disposal in Response to Physiological Hyperinsulinemia and Basal Glucose and Free Fatty Acid Concentrations in Healthy Volunteers*
Authors: Abbasi Fahim , McLaughlin Tracey , Lamendola Cindy , Reaven Gerald M.
Published: January 2014

This study was initiated to see if defects in the ability of physiological hyperinsulinemia (∼60 μU/mL) to stimulate glucose uptake in healthy, nondiabetic volunteers are associated with increases in concentrations of plasma glucose and free fatty acid (FFA) when measured at basal insulin concentrations (∼10 μU/mL). We recruited 22 volunteers (12 women and 10 men) for these studies, with a (mean ± sem) body mass index of 24.8 ± 0.5 kg/m2. Resistance to insulin-mediated glucose disposal during physiological hyperinsulinemia was determined by suppressing endogenous insulin and determining the steady-state plasma glucose (SSPG) and steady-state plasma insulin (SSPI) concentrations at the end of a 3-h infusion, period during which glucose (267 mg/m2·min) and insulin (32 mU/m2·min) were infused at a constant rate. Glucose, insulin and FFA concentrations were also measured in response to infusion rates of glucose (50 mg/m2·min) and insulin (6 mU/m2·min). The SSPI concentration (mean ± sem) during physiological hyperinsulinemia was 64 ± 3 μU/mL), in contrast to 12 ± 0.4 μU/mL during the basal insulin study. The results demonstrated a significant relationship between SSPG concentration in response to physiological hyperinsulinemia (SSPG60) and SSPGBasal (r = 0.57, P < 0. 01) and FFABasal (r = 0.73, P < 0.001). Furthermore, FFABasal and SSPGBasal were significantly correlated (r = 0.47, P < 0.05). Comparison of the seven most insulin-resistant and seven most insulin sensitive individuals (SSPG60 values of 209 ± 16 vs. 64 ± 8 mg/dL) revealed that the insulin-resistant group also had significantly higher SSPGBasal (105 ± 5 vs. 78 ± 7 mg/dL, P < 0.01) and FFABasal (394 ± 91 vs. 104 ± 41, P < 0.02) concentrations. However, random fasting plasma glucose and FFA concentrations of the two groups were not different. The results presented demonstrate that individual differences in the ability of elevated insulin concentrations to stimulate muscle glucose disposal are significantly correlated with variations in insulin regulation of plasma glucose and FFA concentrations at basal insulin concentrations.
Normal Ovulatory Women with Polycystic Ovaries Have Hyperandrogenic Pituitary-Ovarian Responses To Gonadotropin-Releasing Hormone-Agonist Testing*
Authors: Chang Peter L. , Lindheim Steven R. , Lowre Cheri , Ferin Michel , Gonzalez Frank , Berglund Lars , Carmina Enrico , Sauer Mark V. , Lobo Rogerio A.
Published: January 2014

Women with polycystic ovary syndrome (PCOS) have chronic anovulation and hyperandrogenism and frequently have abnormalities in their lipid profiles and insulin/insulin-like growth factor axis that increase their lifetime risk for cardiovascular disease. Normal ovulatory women may have polycystic ovaries on ultrasonography and yet lack the clinical features of PCOS. To further explore whether ovulatory women without clinical/biochemical hyperandrogenism but with polycystic appearing ovaries (ov-PAO) have subclinical features of PCOS, we prospectively characterized 26 ov-PAO women and matched them by age and body mass index to 25 ovulatory women with normal appearing ovaries (ov-NAO) and to 22 women with PCOS. After an overnight fast, all women had baseline endocrine and metabolic assessments. In addition, a subset of each group of women underwent GnRH-agonist (leuprolide acetate 1 mg sc) testing, ACTH stimulation, and an insulin tolerance test (ITT). At baseline, ov-PAO and ov-NAO women had similar endocrine profiles (LH, LH:FSH, androstenedione, and DHEAS). Compared with ov-NAO, 31% of ov-PAO women had reduced glucose responses after insulin (Kitt), suggesting mild insulin resistance, and 35% had high density lipoprotein levels below 35 mg/dL, a level considered to represent significant cardiovascular risk. After GnRH-agonist, ov-PAO women had response patterns in LH, total testosterone, and 17-hydroxyprogesterone (17-OHP) that were intermediate between ov-NAO and women with PCOS. Ovarian responses were above the normal range in 30–40% of women with ov-PAO. In ov-PAO, peak responses of LH after leuprolide correlated with triglyceride levels (P < 0.05) and peak responses of 17-OHP correlated inversely with Kitt values (P < 0.05). No significant differences were noted with ACTH testing. In conclusion, occult biochemical ovarian hyperandrogenism may be uncovered using GnRH-agonist in ovulatory women with ov-PAO, while adrenal responses remain normal. Subtle metabolic abnormalities may also be prevalent.
Differential Regulation by Troglitazone of Plasminogen Activator Inhibitor Type 1 in Human Hepatic and Vascular Cells1
Authors: Nordt Thomas K. , Peter Karlheinz , Bode Christoph , Sobel Burton E.
Published: January 2014

Troglitazone, a novel oral insulin sensitizer, normalizes increased plasma activity of plasminogen activator inhibitor type 1 (PAI-1) in hyperinsulinemic patients such as women with polycystic ovary syndrome and patients with type 2 diabetes mellitus. However, underlying mechanisms have not yet been fully elucidated.

Human hepatic and vascular cells, the main sources of circulating PAI-1, were studied in cell culture. In human hepatic cells, PAI-1 accumulated in conditioned medium by 23% within 24 h after exposure to 3 μg/mL troglitazone (P= 0.001). The accumulation depended on the concentration of troglitazone, but not that of insulin (known to stimulate PAI-1 synthesis). By contrast, in human aortic smooth muscle cells, 3μ g/mL troglitazone decreased basal PAI-1 expression by 23% (P = 0.037) and decreased transforming growth factor-β-induced expression by 34% (P = 0.026). Concomitant insulin had no effect. Tissue-type plasminogen activator was decreased by 38% (P = 0.002). In human endothelial cells, PAI-1 was diminished by 32% (P< 0.001), whereas tissue-type plasminogen activator was unaffected.

The results suggest that the reduction in plasma activity of PAI-1 induced by troglitazone in patients may reflect both directly mediated diminution of its elaboration from vessel walls and indirectly mediated reduction of its hepatic synthesis secondary to attenuation of hyperinsulinemia (known to increase the hepatic synthesis of PAI-1).
Characterization of Two Novel Homozygous Missense Mutations Involving Codon 6 and 259 of Type II 3β-Hydroxysteroid Dehydrogenase (3βHSD) Gene Causing, Respectively, Nonsalt-Wasting and Salt-Wasting 3βHSD Deficiency Disorder1
Authors: Zhang Li , Mason J. Ian , Naiki Yasuhiro , Copeland Kenneth C. , Castro-Magana Mariano , Gordon-Walker Timothy T. , Chang Ying T. , Pang Songya
Published: January 2014

We identified two homozygous missense mutations in the human type II 3β-hydroxysteroid dehydrogenase (3βHSD) gene, the first in codon 6 of exon II [CTT (Leu) to TTT (Phe)] in a male infant with hyperpigmented scrotum and hypospadias, raised as a male and no apparent salt-wasting since neonatal age, and the second in codon 259 of exon IV [ACG (Thr) to ATG (Met)] in a male pseudohermaphrodite with labial scrotal folds, microphallus, chordee, and fourth degree hypospadias, raised as a female and with salt-wasting disorder since neonatal age. In vitro transient expression of mutant type II 3βHSD complementary DNAs of L6F, T259M, as well as T259R for comparison was examined by a site-directed mutagenesis and transfection of construct into COS-1 and COS-7 cells. Northern blot analysis revealed expression of similar amounts of type II 3βHSD messenger ribonucleic acid from the COS-1 cells transfected by L6F, T259M, T259R, and wild-type (WT) complementary DNAs. Western immunoblot analysis revealed a similar amount of L6F mutant protein compared to WT enzyme from COS-1 cells, but neither L6F from COS-7 cells nor T259M or T259R mutant protein in COS-1 or COS-7 cells was detectable. Enzyme activity in intact COS-1 cells using 1 μmol/L pregnenolone as substrate in the medium after 6 h revealed relative conversion rates of pregnenolone to progesterone of 46% by WT enzyme, 22% by L6F enzyme, and 8% by T259M enzyme and less than 4% activity by T259R enzyme. Using 1 μmol/L dehydroepiandrosterone as substrate, the relative conversion rate of dehydroepiandrosterone to androstenedione after 6 was 89% by WT enzyme, 35% by L6F enzyme, 5.1% by T259M enzyme and no activity by T259R enzyme. However, the L6F mutant 3βHSD activity, despite its demonstration in the intact cells, was not detected in homogenates of COS-1 cells or in immunoblots of COS-7 cells, suggestive of the relatively unstable nature of this protein in vitro, possibly attributable to the decreased 3βHSD activity. In the case of T259M and T259R mutations, consistently undetectable proteins in both COS cells despite detectable messenger ribonucleic acids indicate severely labile proteins resulting in either no or very little enzyme activity, and these data further substantiate the deleterious effect of a structural change in this predicted putative steroid-binding domain of the gene. In conclusion, the findings of the in vitro study of mutant type II 3βHSD enzyme activities correlated with a less severe clinical phenotype of nonsalt-wasting and a lesser degree of genital ambiguity in the patient with homozygous L6F mutation compared to a more severe clinical phenotype of salt-wasting and severe degree of genital ambiguity in the patient with homozygous T259M mutation in the gene.
Effects of 10 Days of Endurance Exercise Training on the Suppression of Whole Body and Regional Lipolysis by Insulin1
Authors: Hickner R. C. , Racette S. B. , Binder E. F. , Fisher J. S. , Kohrt W. M.
Published: January 2014

The aim of this study was to evaluate in premenopausal women (10 sedentary obese women) the effects of 10 days of exercise on the suppression of whole body and regional lipolysis by insulin. Lipolysis was determined using 2H5-glycerol infusion and microdialysis of sc adipose tissue during a two-stage hyperinsulinemic-euglycemic clamp [10 (LO) and 20 (MO) mU/m·min]. Microdialysis probes were positioned in abdominal and femoral sc adipose tissue to monitor interstitial glycerol and blood flow. Basal plasma glycerol was 86.7 ± 17.0 and 100.3 ± 19.8 μmol/L before and after training, respectively (P < 0.05). Plasma glycerol was suppressed to a greater extent after [to 47 ± 5% (LO) and 42 ± 5% (MO) of basal] than before [to 62 ± 8% (LO) and 55 ± 8% (MO) of basal] training. The rate of appearance of glycerol was suppressed to 49 ± 7% and 40 ± 5% of basal during LO and to 38 ± 5% and 30 ± 4% of basal during MO (P < 0.05) before and after training, respectively. There were no differences in the suppression of lipolysis in abdominal as well as femoral sc adipose tissue as evidenced by similar reductions in dialysate glycerol levels before and after training in each of these tissues. The results indicate that the antilipolytic response to insulin can be improved through endurance exercise training. Intraabdominal adipose tissue or skeletal muscle may be the site of improved antilipolytic response to insulin after training, as improvement was not evident in abdominal or femoral sc adipose tissue.
Serial Analysis of Gene Expression as a Tool to Assess the Human Thyroid Expression Profile and to Identify Novel Thyroidal Genes*
Authors: Pauws E. , Moreno J. C. , Tijssen M. , Baas F. , de Vijlder J. J. M. , Ris-Stalpers C.
Published: January 2014

The assessment of the expression profile of normal human thyroid tissue using serial analysis of gene expression (SAGE) generated a collection of 10,994 sequence transcripts (tags). Each tag represented a messenger RNA transcript, and, in total, 6099 different tags could be distinguished. The presence and abundance of thyroid-specific transcripts showed the overall expression profile to be from a normal thyroid cell. The expression level of several transcripts was confirmed on Northern blot. Seventy percent of tags could not be attributed to a known human gene and, therefore, possibly correspond to novel genes putatively involved in thyroid function. The tag sequence generated by the SAGE technique can be used to further characterize these novel genes. In this way, application of the SAGE technique to thyroid tissue gives insight in the expression profile of a normal thyroid gland and provides the information to characterize novel genes involved in thyroid pathology, such as congenital hypothyroidism and thyroid neoplasia.
Glucocorticoid Stimulation of Corticotropin-Releasing Hormone Gene Expression Requires a Cyclic Adenosine 3′,5′-Monophosphate Regulatory Element in Human Primary Placental Cytotrophoblast Cells*
Authors: Cheng You-Hong , Nicholson Richard C. , King Bruce , Chan Eng-Cheng , Fitter John T. , Smith Roger
Published: January 2014

Production of placental CRH, which is identical to the peptide synthesized and secreted in the hypothalamus, has been linked to human parturition. Glucocorticoids stimulate placental CRH secretion and messenger ribonucleic acid expression, in contrast to their inhibition of CRH synthesis in the hypothalamus. A positive feedforward loop involving glucocorticoid-CRH-ACTH-glucocorticoid is thought to drive the exponential increase in placental CRH leading to delivery. Tissue-specific effects of glucocorticoids on CRH expression are therefore of interest. Using human primary placental cells, we investigated the mechanism by which glucocorticoids stimulate placental CRH gene expression. Nuclear run-on transcription shows that in human placental cells glucocorticoids up-regulate transcription of human CRH (hCRH). Using transient transfection assays we demonstrate that dexamethasone up-regulates both basal and cAMP-stimulated hCRH promoter activity, correlating well with the increase in endogenous CRH peptide levels. Through mutagenesis and deletion analyses we show that dexamethasone stimulation of hCRH gene transcription requires a functional cAMP regulatory element (CRE); this CRE is adequate to confer dexamethasone stimulation upon a heterologous promoter, and electrophoretic mobility shift assay studies show that a placental nuclear protein specifically binds to the hCRH CRE.
Estradiol Acts as a Germ Cell Survival Factor in the Human Testis in Vitro*
Authors: Pentikäinen Virve , Erkkilä Krista , Suomalainen Laura , Parvinen Martti , Dunkel Leo
Published: January 2014

The necessity of estrogens for male fertility was recently discovered in studies on both estrogen receptor α knockout and aromatase (cyp 19 gene) knockout mice. However, direct testicular effects of estrogens in male reproduction have remained unclear. Here we studied the protein expression of ERα and the recently described estrogen receptor β in the human seminiferous epithelium and evaluated the role of 17β-estradiol, the main physiological estrogen, in male germ cell survival. Interestingly, both estrogen receptors α and β were found in early meiotic spermatocytes and elongating spermatids of the human testis. Furthermore, low concentrations of 17β-estradiol (10−9 and 10−10 mol/L) effectively inhibited male germ cell apoptosis, which was induced in vitro by incubating segments of human seminiferous tubules without survival factors (i.e. serum and hormones). Dihydrotestosterone, which, in addition to estradiol, is an end metabolite of testosterone, was also capable of inhibiting testicular apoptosis, but at a far higher concentration (10−7 mol/L) than estradiol. Thus, estradiol appears to be a potent germ cell survival factor in the human testis. The novel findings of the present study together with the previously reported indirect effects of estrogens on male germ cells indicate the importance of estrogens for the normal function of the testis.
Long-Term Follow-Up Results of Postoperative Radiotherapy in 36 Patients with Acromegaly
Authors: Biermasz Nienke R. , van Dulken Hans , Roelfsema Ferdinand
Published: January 2014

In acromegaly, pituitary irradiation is a slow, but effective, intervention in decreasing GH concentration. Few studies addressing the outcome of radiotherapy have used the currently accepted strict criteria for remission in the analysis of data. These studies report a low percentage of remission after radiotherapy. Doubt has especially been raised as to whether radiotherapy is effective in normalizing serum insulin-like growth factor (IGF)-I concentration. We analyzed the long-term follow-up data of postoperatively administered radiotherapy in 36 patients with postoperative persistent acromegaly, using both the normalization of GH suppression during oral glucose loading (GTT) and the normalization of IGF-I concentration as criteria for remission. Before radiotherapy, mean suppressed GH was 9.8 ± 1.9 mU/L (n = 31), and mean IGF-I concentration was 44.3 ± 3.9 nmol/L, equivalent to + 4.76 ± 0.78 age-related IGF-I sd score (n = 13). The median radiation dose was 40 Gray (range, 25–50 Gray).

At 5, 10, and 15 yr follow-up, 18 out of 30 patients (60%), 23 out of 31 patients (74%), and 16 out of 19 patients (84%), respectively, achieved normal serum IGF-I concentration. At the last assessment of all patients, after a mean follow-up period of 139 ± 12 months, 27 out of 36 (75%) patients had a normal IGF-I concentration without additional medication, whereas 5 patients still required treatment with octreotide. Remission, as judged by normalization of GH suppression during GTT, was documented in 65% of patients from 2–5 yr after radiotherapy (n = 34); in 69% of patients, up to 10 yr after radiotherapy (n = 29); and in 71% of patients, up to 15 yr post irradiation (n = 17). At the latest assessment, a mean of 125± 11 months after radiotherapy, 71% of patients (n = 35) were in remission, as defined by normal suppression of serum GH during GTT. Remission, as judged by normalization of both GTT and IGF-I, was found in 40% of patients 3–5 yr after radiotherapy (n = 30); in 61% of patients, 6–10 yr after radiotherapy (n = 28); in 65%, after 11–15 yr after radiotherapy (n = 17); and in 63% of patients, at the end of the follow-up period (n = 35). Substitution of one or more pituitary hormone deficiencies was required in 11% of patients postoperatively; in 29%, 5 yr after radiotherapy; in 54%, 10 yr after radiotherapy; and in 58%, more than 15 yr after radiotherapy. Our findings support the use of radiotherapy as an effective intervention in the treatment of residual clinical activity of disease after surgery for acromegaly.