Ablative performance of carbon-carbon nosetips in simulated re-entry environments

A summary is presented of ablation performance data for carbon-carbon nosetip models obtained over a range of pressures from 10 to 168 atm. Two classes of tests are reviewed: (1) steady state, in which a constant environment is imposed on the model, and (2) ramp, in which the pressure is increased from 10 to 80 atmospheres to simulate re-entry pressure history. Comparison of arc test parameters with typical reentry vehicle parameters is included, to assess the adequacy of the test simulation. Based on this comparison, recommendations are made for facility developments which would yield improved simulation capability for reentry vehicle nosetip ablative performance

Metformin for the Treatment of the Polycystic Ovary Syndrome

This Journal feature begins with a case vignette that includes a therapeutic recommendation. A discussion of the clinical problem and the mechanism of benefit of this form of therapy follows. Major clinical studies, the clinical use of this therapy, and potential adverse effects are reviewed. Relevant formal guidelines, if they exist, are presented. The article ends with the author’s clinical recommendations. A 23-year-old woman with known polycystic ovary syndrome visits her family physician. She has taken oral contraceptive pills in the past but did not tolerate them and is not currently receiving any treatment. She has three or four menstrual periods per year and is not interested in becoming pregnant now, but she will be getting married in a year. She has heard that the polycystic ovary syndrome is associated with diabetes and is concerned because both her mother and father have type 2 diabetes. Her bodymass index (the weight in kilograms divided by the square of the height in meters) is 32, her waist circumference is 38 in. (96.5 cm), her serum total testosterone level is elevated at 0.9 ng per milliliter (90 ng per deciliter, or 2.9 nmol per liter), her plasma high-density lipoprotein cholesterol level is 35 mg per deciliter (0.9 mmol per liter), and her triglyceride level is 190 mg per deciliter (2.1 mmol per liter). Her serum glucose level 2 hours after the ingestion of 75 g of dextrose is 138 mg per deciliter (7.7 mmol per liter). The physician wonders whether treatment with metformin would be beneficial and refers the patient to an endocrinologist

Decreases in ovarian cytochrome P450c17 alpha activity and serum free testosterone after reduction of insulin secretion in polycystic ovary syndrome

BACKGROUND Insulin resistance and increased ovarian cytochrome P450c17α activity are both features of the polycystic ovary syndrome. P450c17α, which is involved in androgen biosynthesis, has both 17α-hydroxylase and 17,20-lyase activities. Increased activity of this enzyme results in exaggerated conversion of progesterone to 17α-hydroxyprogesterone in response to stimulation by gonadotropin. We hypothesized that hyperinsulinemia stimulates ovarian P450c17α activity. METHODS We measured serum steroid concentrations during fasting and the response of serum 17α-hydroxyprogesterone to leuprolide, a gonadotropin-releasing hormone agonist, and performed oral glucose-tolerance tests before and after oral administration of either metformin (500 mg three times daily) or placebo for four to eight weeks in 24 obese women with the polycystic ovary syndrome. RESULTS In the 11 women given metformin, the mean (±SE) area under the serum insulin curve after oral glucose administration decreased from 9303±1603 to 4982±911 μU per milliliter per minute (56±10 to 30±6 nmol per liter per minute) (P = 0.004). This decrease was associated with a reduction in the basal serum 17α-hydroxyprogesterone concentration from 135±21 to 66±7 ng per deciliter (4.1±0.6 to 2.0±0.2 nmol per liter) (P = 0.01) and a reduction in the leuprolide-stimulated peak serum 17α-hydroxyprogesterone concentration from 455±54 to 281±52 ng per deciliter (13.7±1.6 to 8.5±1.6 nmol per liter) (P = 0.01). The serum 17α-hydroxyprogesterone values increased slightly in the placebo group. In the metformin group, the basal serum luteinizing hormone concentration decreased from 8.5±2.2 to 2.8±0.5 mlU per milliliter (P = 0.01), the serum free testosterone concentration decreased from 0.34±0.07 to 0.19±0.05 ng per deciliter (12±3 to 7±2 pmol per liter) (P = 0.009), and the serum sex hormone–binding globulin concentration increased from 0.8±0.2 to 2.3±0.6 μg per deciliter (29±7 to 80±21 nmol per liter) (P CONCLUSIONS In obese women with the polycystic ovary syndrome, decreasing serum insulin concentrations with metformin reduces ovarian cytochrome P450c17α activity and ameliorates hyperandrogenism

Phase Field Modeling of Fracture and Stress Induced Phase Transitions

We present a continuum theory to describe elastically induced phase transitions between coherent solid phases. In the limit of vanishing elastic constants in one of the phases, the model can be used to describe fracture on the basis of the late stage of the Asaro-Tiller-Grinfeld instability. Starting from a sharp interface formulation we derive the elastic equations and the dissipative interface kinetics. We develop a phase field model to simulate these processes numerically; in the sharp interface limit, it reproduces the desired equations of motion and boundary conditions. We perform large scale simulations of fracture processes to eliminate finite-size effects and compare the results to a recently developed sharp interface method. Details of the numerical simulations are explained, and the generalization to multiphase simulations is presented

Activation of the LH receptor up regulates the type 2 adiponectin receptor in human granulosa cells

PURPOSE: Adiponectin is a predominantly adipocyte-derived hormone which influences insulin sensitivity and energy homeostasis through at least two receptors, AdipoR1 and AdipoR2. In animal models, adiponectin may regulate ovarian steroidogenesis, folliculogenesis, and ovulation. The receptors AdipoR1 and AdipoR2 are present in the human ovary, but their regulation is unknown. In these studies, we determined the effects of LH receptor activation on the expression and function of the two adiponectin receptors in human granulosa cells. METHODS: Granulosa cells were obtained at the time of oocyte retrieval in women undergoing in vitro fertilization (IVF). Cells were isolated and cultured for 48 h in DMEM/F12 medium with 5 % FBS and 50 ug/ml gentamicin. Medium was changed to low serum for 12 h and cells were treated with hCG (100 ng/ml), forskolin (30 μMol/L), or FSH (1 IU/ml) for 24 h for mRNA experiments. mRNA was isolated and RT PCR was performed using Taqman assays and quantification with the delta delta CT method. For immunocytochemistry, cells were grown on chamber slides and treated with hCG for 1 to 24 h and fixed with acetone. ICC was performed with polyclonal rabbit primary antibodies followed by alexa fluor goat anti-rabbit antibody and imaging with a fluorescence microscope and Zeiss software analysis. 3β-hydroxysteroid dehydrogenase (3βHSD) enzyme activity was determined by measuring the progesterone produced when cells were provided with an excess of 22-hydroxy-cholesterol as substrate following an incubation with hCG (1 IU/ml) and/or adiponectin (10 ng/ml). Progesterone content in the media was determined by ELISA. RESULTS: Messenger RNA for the two Adiponectin receptors is differentially regulated by activation of LHR with hCG treatment. AdipoR2 was increased nearly 4-fold (p < 0.05), whereas AdipoR1 expression was not changed by hCG treatment. Treatment with either FSH or forskolin (an activator of cAMP) had similar effects. Basal AdipoR2 protein was fairly low in granulosa cells in culture however treatment of cells with hCG resulted in a discernible increase in immunodetectable cytoplasmic protein as early as 6 h after treatment and was maintained for at least 24 h. The number of cells positive for AdipoR2 at 6 h increased from a basal of 20 % to almost 60 % (p < 0.05). Adiponectin treatment of hCG-primed cells resulted in increased 3βHSD activity by approximately 60 % over hCG alone and more than 3-fold over basal levels. CONCLUSIONS: AdipoR2 is regulated by the LH receptor function via a cAMP dependant mechanism. Increased expression of adipoR2 prior to and following ovulation may contribute to enhanced 3βHSD activity and increased progesterone secretion by the corpus luteum of the ovary. Dysregulation of adiponectin that may occur with PCOS may impair normal progesterone production

Effect on Insulin-Stimulated Release of D-Chiro-Inositol-Containing Inositolphosphoglycan Mediator during Weight Loss in Obese Women with and without Polycystic Ovary Syndrome

Background. A deficiency of D-chiro-inositol-inositolphosphoglycan mediator (DCI-IPG) may contribute to insulin resistance in polycystic ovary syndrome (PCOS). Whether the relationship between impaired DCI-IPG release and insulin resistance is specific to PCOS rather than obesity is unknown. We assessed insulin-released DCI-IPG and its relationship to insulin sensitivity at baseline and after weight loss in obese women with and without PCOS. Methods. Obese PCOS (n=16) and normal (n=15) women underwent 8 weeks of a hypocaloric diet. The Matsuda index, area under the curve DCI-IPG (AUCDCI-IPG), AUCinsulin, and AUCDCI-IPG/AUCinsulin were measured during a 2 hr OGTT at baseline and 8 weeks. Results. PCOS women had lower AUCDCI-IPG/AUCinsulin at baseline and a significant relationship between AUCDCI-IPG/AUCinsulin and Matsuda index (p=0.0003), which was not present in controls. Weight loss was similar between PCOS (−4.08 kg) and normal women (−4.29 kg, p=0.6281). Weight loss in PCOS women did not change the relationship between AUCDCI-IPG/AUCinsulin and Matsuda index (p=0.0100), and this relationship remained absent in control women. Conclusion. The association between AUCDCI-IPG/AUCinsulin and insulin sensitivity was only found in PCOS but not in normal women, and this relationship was unaffected by weight loss. DCI and its messenger may contribute to insulin resistance in PCOS independent of obesity

Inositol(s) from Bench to Bedside in Endocrinology and Gynecology

The family of inositol(s) is a primordial group of ubiquitary molecules, which appeared at the beginning of evolution of life. Nature has used inositol(s) for several biological functions exploiting minimal changes in the structure. This family plays a pivotal role in regulating many metabolic pathways and hormonal signalling, and its essential function is well known in reproduction process. Plenty of experimental and clinical data have shown that inositols play a pivotal role, as drugs, in treating several pathologies such as PCOS, metabolic syndrome, and gestational diabetes; these natural molecules allow avoiding congenital anomalies and they are very effective in improving assisted reproduction technology (ART); moreover, they have demonstrated promising anticancer activities as shown in numerous studies. This special issue will take in consideration reviews, original research articles, short communications, and any scientific contribution providing both new insights from old data and updated results from experimental or clinical studies, thus pushing forward the boundaries of knowledge of inositol(s) in endocrinology and gynecology

Corrigendum to "Inositol(s) from Bench to Bedside in Endocrinology and Gynecology"

[This corrects the article DOI: 10.1155/2017/8515703.]