1,117 research outputs found

    Metformin as a Therapeutic Target in Endometrial Cancers.

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    Endometrial cancer is the most common gynecologic malignancy in developed countries. Its increasing incidence is thought to be related in part to the rise of metabolic syndrome, which has been shown to be a risk factor for the development of hyperestrogenic and hyperinsulinemic states. This has consequently lead to an increase in other hormone-responsive cancers as well e.g., breast and ovarian cancer. The correlation between obesity, hyperglycemia, and endometrial cancer has highlighted the important role of metabolism in cancer establishment and persistence. Tumor-mediated reprogramming of the microenvironment and macroenvironment can range from induction of cytokines and growth factors to stimulation of surrounding stromal cells to produce energy-rich catabolites, fueling the growth, and survival of cancer cells. Such mechanisms raise the prospect of the metabolic microenvironment itself as a viable target for treatment of malignancies. Metformin is a biguanide drug that is a first-line treatment for type 2 diabetes that has beneficial effects on various markers of the metabolic syndrome. Many studies suggest that metformin shows potential as an adjuvant treatment for uterine and other cancers. Here, we review the evidence for metformin as a treatment for cancers of the endometrium. We discuss the available clinical data and the molecular mechanisms by which it may exert its effects, with a focus on how it may alter the tumor microenvironment. The pleiotropic effects of metformin on cellular energy production and usage as well as intercellular and hormone-based interactions make it a promising candidate for reprogramming of the cancer ecosystem. This, along with other treatments aimed at targeting tumor metabolic pathways, may lead to novel treatment strategies for endometrial cancer

    Spatiotemporal patterns in methane flux and gas transfer velocity at low wind speeds: implications for upscaling studies on small lakes

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    Lakes contribute significantly to the global natural emissions of methane (CH4) and carbon dioxide. However, to accurately incorporate them into the continental carbon balance more detailed surveys of lacustrine greenhouse gas emissions are needed, especially in respect to spatiotemporal variability and to how this affects the upscaling of results. We investigated CH4 flux from a small, wind-shielded lake during 10 field trips over a 14 month period. We show that floating chambers may be used to calibrate the relationship between gas transfer velocity (k) and wind speed at 10 m height (U10) to the local system, in order to obtain more accurate estimates of diffusive CH4 flux than by applying general models predicting k based on U10. We confirm earlier studies indicating strong within-lake spatial variation in this relationship and in ebullitive CH4 flux within the lake basin. However, in contrast to the pattern reported in other studies, ebullitive CH4 flux was highest in the central parts of the lake. Our results indicate positive relationships between k and U10 at very low U10 (0–3 m s-1), which disagrees with earlier suggestions that this relationship may be negligible at low U10 values. We estimate annually averaged open water CH4 emission from Lake Gerzensee to be 3.6–5.8 mmol m-2 d-1. Our data suggest that estimates of greenhouse gas emissions from aquatic systems to the atmosphere based on the upscaling of short-term and small-scale measurements can be improved if both spatial and temporal variabilities of emissions are taken into account

    Larotrectinib efficacy and safety in TRK fusion cancer: An expanded clinical dataset showing consistency in an age and tumor agnostic approach

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    Background: TRK fusion cancer results from gene fusions involving NTRK1, NTRK2 or NTRK3. Larotrectinib, the first selective TRK inhibitor, has demonstrated an overall response rate (ORR) of 75% with a favorable safety profile in the first 55 consecutively enrolled adult and pediatric patients with TRK fusion cancer (Drilon et al.,NEJM2018). Here, we report the clinical activity of larotrectinib in an additional 35 TRK fusion cancer patients and provide updated follow-up of the primary analysis set (PAS) of 55 patients as of 19thFeb 2018. Methods: Patients with TRK fusion cancer detected by molecular profiling from 3 larotrectinib clinical trials (NCT02122913, NCT02637687, and NCT02576431) were eligible.Larotrectinib was administered until disease progression, withdrawal, or unacceptable toxicity. Disease status was assessed using RECIST version 1.1. Results: As of Feb 2018, by independent review, 6 PRs in the PAS deepened to CRs. The median duration of response (DoR) and progression-free survival in the PAS had still not been reached, with 12.9 months median follow-up. At 1 year, 69% of responses were ongoing, 58% of patients remained progression-free and 90% of patients were alive. An additional 19 children and 25 adults (age range, 0.1-78 years) with TRK fusion cancer were enrolled after the PAS, and included cancers of the salivary gland, thyroid, lung, colon, melanoma, sarcoma, GIST and congenital mesoblastic nephroma. In 35 evaluable patients, the ORR by investigator assessment was 74% (5 CR, 21 PR, 6 SD, 2 PD, 1 not determined). In these patients, with median follow-up of 5.5 months, median DoR had not yet been reached, and 88% of responses were ongoing at 6 months, consistent with the PAS. Adverse events (AEs) were predominantly grade 1, with dizziness, increased AST/ALT, fatigue, nausea and constipation the most common AEs reported in ≥ 10% of patients. No AE of grade 3 or 4 related to larotrectinib occurred in more than 5% of patients. Conclusions: TRK fusions are detected in a broad range of tumor types. Larotrectinib is an effective age- and tumor-agnostic treatment for TRK fusion cancer with a positive safety profile. Screening patients for NTRK gene fusions in solid- and brain tumors should be actively considered

    Characterization of a high-power tapered semiconductor amplifier system

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    We have characterized a semiconductor amplifier laser system which provides up to 200mW output after a single-mode optical fiber at 780nm wavelength. The system is based on a tapered semiconductor gain element, which amplifies the output of a narrow-linewidth diode laser. Gain and saturation are discussed as a function of operating temperature and injection current. The spectral properties of the amplifier are investigated with a grating spectrometer. Amplified spontaneous emission (ASE) causes a spectral background with a width of 4nm FWHM. The ASE background was suppressed to below our detection limit by a proper choice of operating current and temperature, and by sending the light through a single-mode optical fiber. The final ASE spectral density was less than 0.1nW/MHz, i.e. less than 0.2 % of the optical power. Related to an optical transition linewidth of Γ/2π=6\Gamma/2\pi=6 MHz for rubidium, this gives a background suppression of better than -82dB. An indication of the beam quality is provided by the fiber coupling efficiency up to 59 %. The application of the amplifier system as a laser source for atom optical experiments is discussed

    Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

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    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews

    The polymer phase of the TDAE-C60_{60} organic ferromagnet

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    The high-pressure Electron Spin Resonance (ESR) measurements were preformed on TDAE-C60_{60} single crystals and stability of the polymeric phase was established in the PTP - T parameter space. At 7 kbar the system undergoes a ferromagnetic to paramagnetic phase transition due to the pressure-induced polymerization. The polymeric phase remains stable after the pressure release. The depolymerization of the pressure-induced phase was observed at the temperature of 520 K. Below room temperature, the polymeric phase behaves as a simple Curie-type insulator with one unpaired electron spin per chemical formula. The TDAE+^+ donor-related unpaired electron spins, formerly ESR-silent, become active above the temperature of 320 K and the Curie-Weiss behavior is re-established.Comment: Submitted to Phys. Rev.

    Telepresence and the Role of the Senses

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    The telepresence experience can be evoked in a number of ways. A well-known example is a player of videogames who reports about a telepresence experience, a subjective experience of being in one place or environment, even when physically situated in another place. In this paper we set the phenomenon of telepresence into a theoretical framework. As people react subjectively to stimuli from telepresence, empirical studies can give more evidence about the phenomenon. Thus, our contribution is to bridge the theoretical with the empirical. We discuss theories of perception with an emphasis on Heidegger, Merleau-Ponty and Gibson, the role of the senses and the Spinozian belief procedure. The aim is to contribute to our understanding of this phenomenon. A telepresence-study that included the affordance concept is used to empirically study how players report sense-reactions to virtual sightseeing in two cities. We investigate and explore the interplay of the philosophical and the empirical. The findings indicate that it is not only the visual sense that plays a role in this experience, but all senses

    An ecological method for the sampling of nonverbal signalling behaviours of young children with profound and multiple learning disabilities (PMLD)

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    - Background: Profound and multiple learning disabilities (PMLD) are a complex range of disabilities that affect the general health and wellbeing of the individual and their capacity to interact and learn. - Method: We developed a new methodology to capture the nonsymbolic signalling behaviours of children with PMLD within the context of a face-to-face interaction with a caregiver to provide analysis at a micro-level of descriptive detail incorporating the use of the ELAN digital video software. - Conclusion: The signalling behaviours of participants in a natural, everyday interaction can be better understood with the use of this innovation in methodology, which is predicated on the ecology of communication. Recognition of the developmental ability of the participants is an integral factor within that ecology. The method presented establishes an advanced account of the modalities through which a child affected by PMLD is able to communicate

    A phase II evaluation of cediranib in the treatment of recurrent or persistent endometrial cancer: An NRG Oncology/Gynecologic Oncology Group study

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    PURPOSE: Cediranib is a multi-tyrosine kinase inhibitor targeting vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF) receptors. This phase II study was conducted to assess activity and tolerability of single-agent cediranib in recurrent/persistent endometrial cancer. PATIENTS AND METHODS: Eligible patients had recurrent or persistent endometrial cancer after receiving one or two prior cytotoxic regimens, measurable disease, and Gynecologic Oncology Group (GOG) performance status of ≤2 (≤1 if two prior cytotoxic regimens given). Cediranib 30mg orally daily for a 28daycycle was administered until disease progression or prohibitive toxicity. Microvessel density (MVD) was measured in tumor tissue from initial hysterectomy specimens and correlated with clinical outcome. Primary endpoints were tumor response and surviving progression-free for six months without subsequent therapy (6-month event-free survival [EFS]). RESULTS: Of 53 patients enrolled, 48 were evaluable for cediranib efficacy and toxicity. Median age was 65.5 years, 52% of patients had received prior radiation, and 73% of patients received only one prior chemotherapy regimen. A partial response was observed in 12.5%. Fourteen patients (29%) had six-month EFS. Median progression-free survival (PFS) was 3.65 months and median overall survival (OS) 12.5 months. No grade 4 or 5 toxicities were observed. A trend towards improved PFS was found in patients whose tumors expressed high MVD. CONCLUSION: Cediranib as a monotherapy treatment for recurrent or persistent endometrial cancer is well tolerated and met protocol set objectives for sufficient activity to warrant further investigation. MVD may be a useful biomarker for activity

    Third structure determination by powder diffractometry round robin (SDPDRR-3)

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    The results from a third structure determination by powder diffractometry (SDPD) round robin are discussed. From the 175 potential participants having downloaded the powder data, nine sent a total of 12 solutions (8 and 4 for samples 1 and 2, respectively, a tetrahydrated calcium tartrate and a lanthanum tungstate). Participants used seven different computer programs for structure solution (ESPOIR, EXPO, FOX, PSSP, SHELXS, SUPERFLIP, and TOPAS), applying Patterson, direct methods, direct space methods, and charge flipping approach. It is concluded that solving a structure from powder data remains a challenge, at least one order of magnitude more difficult than solving a problem with similar complexity from single-crystal data. Nevertheless, a few more steps in the direction of increasing the SDPD rate of success were accomplished since the two previous round robins: this time, not only the computer program developers were successful but also some users. No result was obtained from crystal structure prediction expert
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