Differential Regulation of Growth-Promoting Signalling Pathways by E-Cadherin

Background: Despite the well-documented association between loss of E-cadherin and carcinogenesis, as well as the link between restoration of its expression and suppression of proliferation in carcinoma cells, the ability of E-cadherin to modulate growth-promoting cell signalling in normal epithelial cells is less well understood and frequently contradictory. The potential for E-cadherin to co-ordinate different proliferation-associated signalling pathways has yet to be fully explored. Methodology/Principal Findings: Using a normal human urothelial (NHU) cell culture system and following a calcium-switch approach, we demonstrate that the stability of NHU cell-cell contacts differentially regulates the Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-Regulated Kinase (ERK) and Phosphatidylinositol 3-Kinase (PI3-K)/AKT pathways. We show that stable cell contacts down-modulate the EGFR/ERK pathway, whilst inducing PI3-K/AKT activity, which transiently enhances cell growth at low density. Functional inactivation of E-cadherin interferes with the capacity of NHU cells to form stable calcium-mediated contacts, attenuates E-cadherin-mediated PI3-K/AKT induction and enhances NHU cell proliferation by allowing de-repression of the EGFR/ERK pathway and constitutive activation of beta-catenin-TCF signalling. Conclusions/Significance: Our findings provide evidence that E-cadherin can differentially and concurrently regulate specific growth-related signalling pathways in a context-specific fashion, with direct, functional consequences for cell proliferation and population growth. Our observations not only reveal a novel, complex role for E-cadherin in normal epithelial cell homeostasis and tissue regeneration, but also provide the basis for a more complete understanding of the consequences of E-cadherin loss on malignant transformation

Perusing The Headwaters Of Diversity Among University Presidents

Females and minorities are gaining clout in higher education as the numbers of graduates in each of these groups indicate.  Diversity among university presidents is a reality.  Indications are that the number of women receiving advanced degrees will continue to grow for some time.  Low estimates of graduation rates among women and minorities from years ago do not hold.  The impacts of this reality in higher education will continue to be felt for some time

Comparison of human uterine cervical electrical impedance measurements derived using two tetrapolar probes of different sizes

BACKGROUND We sought to compare uterine cervical electrical impedance spectroscopy measurements employing two probes of different sizes, and to employ a finite element model to predict and compare the fraction of electrical current derived from subepithelial stromal tissue. METHODS Cervical impedance was measured in 12 subjects during early pregnancy using 2 different sizes of the probes on each subject. RESULTS Mean cervical resistivity was significantly higher (5.4 vs. 2.8 Ωm; p < 0.001) with the smaller probe in the frequency rage of 4–819 kHz. There was no difference in the short-term intra-observer variability between the two probes. The cervical impedance measurements derived in vivo followed the pattern predicted by the finite element model. CONCLUSION Inter-electrode distance on the probes for measuring cervical impedance influences the tissue resistivity values obtained. Determining the appropriate probe size is necessary when conducting clinical studies of resistivity of the cervix and other human tissues

Metformin increases cortisol regeneration by 11βHSD1 in obese men with and without type 2 diabetes mellitus

CONTEXT:The mechanism of action of metformin remains unclear. Given the regulation of the cortisol-regenerating enzyme 11βhydroxysteroid dehydrogenase 1 (11βHSD1) by insulin and the limited efficacy of selective 11βHSD1 inhibitors to lower blood glucose when co-prescribed with metformin, we hypothesized that metformin reduces 11βHSD1 activity.OBJECTIVE:To determine whether metformin regulates 11βHSD1 activity in vivo in obese men with and without type 2 diabetes mellitus.DESIGN:Double-blind, randomized, placebo-controlled, crossover study.SETTING:A hospital clinical research facility.PARTICIPANTS:Eight obese nondiabetic (OND) men and eight obese men with type 2 diabetes (ODM).INTERVENTION:Participants received 28 days of metformin (1 g twice daily), placebo, or (in the ODM group) gliclazide (80 mg twice daily) in random order. A deuterated cortisol infusion at the end of each phase measured cortisol regeneration by 11βHSD1. Oral cortisone was given to measure hepatic 11βHSD1 activity in the ODM group. The effect of metformin on 11βHSD1 was also assessed in human hepatocytes and Simpson-Golabi-Behmel syndrome adipocytes.MAIN OUTCOME MEASURES:The effect of metformin on whole-body and hepatic 11βHSD1 activity.RESULTS:Whole-body 11βHSD1 activity was approximately 25% higher in the ODM group than the OND group. Metformin increased whole-body cortisol regeneration by 11βHSD1 in both groups compared with placebo and gliclazide and tended to increase hepatic 11βHSD1 activity. In vitro, metformin did not increase 11βHSD1 activity in hepatocytes or adipocytes.CONCLUSIONS:Metformin increases whole-body cortisol generation by 11βHSD1 probably through an indirect mechanism, potentially offsetting other metabolic benefits of metformin. Co-prescription with metformin should provide a greater target for selective 11βHSD1 inhibitors

Spatial Localization and Quantitation of Androgens in Mouse Testis by Mass Spectrometry Imaging

Androgens are essential for male development and reproductive function. They are transported to their site of action as blood-borne endocrine hormones but can also be produced within tissues to act in intracrine and paracrine fashions. Because of this, circulating concentrations may not accurately reflect the androgenic influence within specific tissue microenvironments. Mass spectrometry imaging permits regional analysis of small molecular species directly from tissue surfaces. However, due to poor ionization and localized ion suppression, steroid hormones are difficult to detect. Here, derivatization with Girard T reagent was used to charge-tag testosterone and 5α-dihydrotestosterone allowing direct detection of these steroids in mouse testes, in both basal and maximally stimulated states, and in rat prostate. Limits of detection were ∼0.1 pg for testosterone. Exemplary detection of endogenous steroids was achieved by matrix-assisted laser desorption ionization and either Fourier transform ion cyclotron resonance detection (at 150 μm spatial resolution) or quadrupole-time-of-flight detection (at 50 μm spatial resolution). Structural confirmation was achieved by collision induced fragmentation following liquid extraction surface analysis and electrospray ionization. This application broadens the scope for derivatization strategies on tissue surfaces to elucidate local endocrine signaling in health and disease

Interrogating a Hexokinase-Selected Small-Molecule Library for Inhibitors of Plasmodium falciparum Hexokinase

This is the published version.Parasites in the genus Plasmodium cause disease throughout the tropic and subtropical regions of the world. P. falciparum, one of the deadliest species of the parasite, relies on glycolysis for the generation of ATP while it inhabits the mammalian red blood cell. The first step in glycolysis is catalyzed by hexokinase (HK). While the 55.3-kDa P. falciparum HK (PfHK) shares several biochemical characteristics with mammalian HKs, including being inhibited by its products, it has limited amino acid identity (∼26%) to the human HKs, suggesting that enzyme-specific therapeutics could be generated. To that end, interrogation of a selected small-molecule library of HK inhibitors has identified a class of PfHK inhibitors, isobenzothiazolinones, some of which have 50% inhibitory concentrations (IC50s) of <1 μM. Inhibition was reversible by dilution but not by treatment with a reducing agent, suggesting that the basis for enzyme inactivation was not covalent association with the inhibitor. Lastly, six of these compounds and the related molecule ebselen inhibited P. falciparum growth in vitro (50% effective concentration [EC50] of ≥0.6 and <6.8 μM). These findings suggest that the chemotypes identified here could represent leads for future development of therapeutics against P. falciparum

Metabolic dysfunction in female mice with disruption of 5α-reductase 1

5α-Reductases irreversibly catalyse A-ring reduction of pregnene steroids, including glucocorticoids and androgens. Genetic disruption of 5α-reductase 1 in male mice impairs glucocorticoid clearance and predisposes to glucose intolerance and hepatic steatosis upon metabolic challenge. However, it is unclear whether this is driven by changes in androgen and/or glucocorticoid action. Female mice with transgenic disruption of 5α-reductase 1 (5αR1-KO) were studied, representing a ‘low androgen’ state. Glucocorticoid clearance and stress responses were studied in mice aged 6 months. Metabolism was assessed in mice on normal chow (aged 6 and 12 m) and also in a separate cohort following 1-month high-fat diet (aged 3 m). Female 5αR1-KO mice had adrenal suppression (44% lower AUC corticosterone after stress), and upon corticosterone infusion, accumulated hepatic glucocorticoids (~27% increased corticosterone). Female 5αR1-KO mice aged 6 m fed normal chow demonstrated insulin resistance (~35% increased area under curve (AUC) for insulin upon glucose tolerance testing) and hepatic steatosis (~33% increased hepatic triglycerides) compared with controls. This progressed to obesity (~12% increased body weight) and sustained insulin resistance (~38% increased AUC insulin) by age 12 m. Hepatic transcript profiles supported impaired lipid β-oxidation and increased triglyceride storage. Female 5αR1-KO mice were also predisposed to develop high-fat diet-induced insulin resistance. Exaggerated predisposition to metabolic disorders in female mice, compared with that seen in male mice, after disruption of 5αR1 suggests phenotypic changes may be underpinned by altered metabolism of glucocorticoids rather than androgens

Video-assisted thoracic surgery (VATS) for resection of metastatic adenocarcinoma as an acceptable alternative

Adenocarcinomas commonly metastasize to the lungs and can be resected using open thoracotomy or video-assisted thoracic surgery (VATS). This study reviews metastatic resections in primary adenocarcinoma patients, using both thoracotomy and VATS. We aim to compare long-term prognoses to test the efficacy and viability of VATS. A retrospective review of primary adenocarcinoma patients who underwent resection of pulmonary metastases from 1990 to 2006 was carried out. Information was obtained by chart review. Endpoints analyzed were disease-free interval (DFI), survival time, and recurrence-free survival (RFS). In a total of 42 (16 male, 26 female; median age 58.5 years) primary adenocarcinoma patients, 21 patients underwent first pulmonary metastatic resection using VATS (7 male, 14 female; median age 57 years) and 21 using thoracotomy (9 male, 12 female; median age 59 years). Primary adenocarcinomas were mainly 27 colorectal (64%) and 11 breast (26%). Two VATS (10%) and three open patients (14%) had local recurrences of the original cancer. Median postoperative follow was 13.3 months [interquartile range (IQR) 4.5–32.8 months] for VATS and 36.9 months (IQR 19.3–48.6 months) after thoracotomy. Median DFI–1 was 22.3 months (IQR 13.5–40.6 months) for VATS patients and 35.6 months (IQR 26.7–61.3 months) for open patients. Second thoracic occurrences were noted in six VATS patients (median DFI–2 9.2 months), and in seven open patients (median DFI-2 21.5 months). Third thoracic occurrences were noted in one VATS patient (DFI-3 18.7 months) and in one thoracotomy patient (DFI-3 21.8 months). Odds ratio of recurrence showed 12.5% less chance of developing recurrence in VATS patients. Five-year RFS was 53% in VATS and 57% in thoracotomy patients. VATS has become a viable alternative to open thoracotomy for resection of pulmonary metastases. In cases of primary adenocarcinoma, VATS showed no increase in number of thoracic recurrences, and comparable RFS. Short-term follow-up is encouraging; long-term follow-up will be needed to confirm these results

The ESCAPS study: a feasibility randomized controlled trial of early electrical stimulation to the wrist extensors and flexors to prevent post-stroke complications of pain and contractures in the paretic arm.

OBJECTIVE: To establish feasibility of initiating electrical stimulation treatment of wrist extensors and flexors in patients early after stroke to prevent muscle contractures and pain. DESIGN: Feasibility randomized controlled trial with economic evaluation. SETTING: A specialist stroke unit in Nottinghamshire. SUBJECTS: A total of 40 patients recruited within 72 hours post-stroke with arm hemiparesis. INTERVENTIONS: Participants were randomized to receive usual care or usual care and electrical stimulation to wrist flexors and extensors for 30 minutes, twice a day, five days a week for three months. Initial treatment was delivered by an occupational therapist or physiotherapist who trained participants to self-manage subsequent treatments. MEASURES: Measures of feasibility included recruitment and attrition rates, completion of treatment, and successful data collection. Outcome data on wrist range of motion, pain, arm function, independence, quality of life, and resource use were measured at 3-, 6-, and 12-months post-randomization. RESULTS: A total of 40 participants (of 215 potentially eligible) were recruited in 15 months (20 men; mean age: 72 (SD: 13.0)). Half the participants lacked mental capacity and were recruited by consultee consent. Attrition at three-month follow-up was 12.5% (death (n = 2), end-of-life care (n = 2), and unable to contact (n = 1)). Compliance varied (mean: 65 (SD: 53)) and ranged from 10 to 166 treatments per patient (target dosage was 120). Data for a valid economic analysis can be adequately collected. CONCLUSION: Early initiation of electrical stimulation was acceptable and feasible. Data collection methods used were feasible and acceptable to participants. A large definitive study is needed to determine if electrical stimulation is efficacious and cost effective

Life Beyond the Solar System: Remotely Detectable Biosignatures

For the first time in human history, we will soon be able to apply to the scientific method to the question "Are We Alone?" The rapid advance of exoplanet discovery, planetary systems science, and telescope technology will soon allow scientists to search for life beyond our Solar System through direct observation of extrasolar planets. This endeavor will occur alongside searches for habitable environments and signs of life within our Solar System. While these searches are thematically related and will inform each other, they will require separate observational techniques. The search for life on exoplanets holds potential through the great diversity of worlds to be explored beyond our Solar System. However, there are also unique challenges related to the relatively limited data this search will obtain on any individual world