An autocrine role for pituitary GABA: Activation of GABA-B receptors and regulation of growth hormone levels

There is increasing evidence suggesting that the neurotransmitter gamma-aminobutyric acid (GABA) is a local factor involved in the regulation of endocrine organs. Examples of such functions are documented in the pancreas, but recent results suggest that GABA may act in a similar way in the pituitary, in which GABA receptors are expressed and pituitary growth hormone (GH) cells provide a source of GABA. We hypothesised that GABA secreted in somatotropes may act as an autoregulatory signaling molecule. To test this hypothesis we first examined the nature of GABA receptors expressed by GH cells. RT-PCR analysis demonstrated that GABA-B receptor subunits R1 and R2 are present in the whole rat pituitary. Laser microdissection of immunostained GH cells, followed by RT-PCR as well as immunoelectron microscopy, showed that GABA-B receptors are expressed on somatotropes. To investigate GABA-B receptor function in somatotropes, we used rat GH3 adenoma cells, which, like pituitary GH cells, express GABA-B R1 and R2 (as assessed by RT-PCR and immunoelectron microscopy) and produce GABA (checked by high performance liquid chromatography). After inhibition of endogenous GABA synthesis, GH production was stimulated by baclofen, a chromatography). After inhibition of endogenous GABA synthesis, GH production was stimulated by bactofen, a GABA-B receptor agonist. By contrast, blocking GABA-B receptors by an antagonist, phaclofen, decreased GH levels. We conclude that in GH-producing cells, GABA acts as an autocrine factor via GABA-B receptors to control GH levels. Copyright (C) 2002 S. KargerAG, Basel

Consumers’ preferences for biodiversity in vineyards: A choice experiment on wine

In recent years consumers\u2019 concerns regarding the environmental impact of food production has significantly increased, also due to food sustainability, food safety and food security issues. A number of certification systems for environmental-friendly products have been created e.g. water-saving labels and fishery sustainable labels. Among various environmental issues, the protection of biodiversity has recently gained popularity both in public opinion and in scientific debate. This paper describes the results of a Choice Experiment on wine consumers to estimate their willingness to pay for biodiversity conservation practices in vineyards. The survey was conducted by direct interviews at a wine tasting event in an Italian winery located at Montefano (Marche). The results show that consumers are willing to pay a premium price for wine certification that takes into account biodiversity not only for medium-high price wines, but also for low-price wines. Finally, quality of wine and organic certification remain important attributes in wine purchasing choices related to expensive wines

GRB 970228 Within the EMBH Model

We consider the gamma-ray burst of 1997 February 28 (GRB 970228) within the ElectroMagnetic Black Hole (EMBH) model. We first determine the value of the two free parameters that characterize energetically the GRB phenomenon in the EMBH model, that is to say the dyadosphere energy, $E_{dya}=5.1\times10^{52}$ ergs, and the baryonic remnant mass $M_{B}$ in units of $E_{dya}$, $B=M_{B}c^{2}/E_{dya}=3.0\times10^{-3}$. Having in this way estimated the energy emitted during the beam-target phase, we evaluate the role of the InterStellar Medium (ISM) number density (n$_{ISM}$) and of the ratio ${\cal R}$ between the effective emitting area and the total surface area of the GRB source, in reproducing the observed profiles of the GRB 970228 prompt emission and X-ray (2-10 keV energy band) afterglow. The importance of the ISM distribution three-dimensional treatment around the central black hole is also stressed in this analysis.Comment: 4 pages, 1 figure, to appear in the Proceedings of the Los Alamos "Gamma Ray Burst Symposium" in Santa Fe, New Mexico, September 8-12 2003 (AIP Conf. Ser.), CHAPTER: GRB Connection to Supernova

Copolymer adsorption kinetics at a selective liquid-liquid interface: Scaling theory and computer experiment

We consider the adsorption kinetics of a regular block-copolymer of total length $N$ and block size $M$ at a selective liquid-liquid interface in the limit of strong localization. We propose a simple analytic theory based on scaling considerations which describes the relaxation of the initial coil into a flat-shaped layer. The characteristic times for attaining equilibrium values of the gyration radius components perpendicular and parallel to the interface are predicted to scale with chain length $N$ and block length $M$ as $\tau_{\perp} \propto M^{1+2\nu}$ (here $\nu\approx 0.6$ is the Flory exponent) and as $\tau_{\parallel} \propto N^2$, although initially the rate of coil flattening is expected to decrease with block size as $\propto M^{-1}$. Since typically $N\gg M$ for multiblock copolymers, our results suggest that the flattening dynamics proceeds faster perpendicular rather than parallel to the interface. We also demonstrate that these scaling predictions agree well with the results of extensive Monte Carlo simulations of the localization dynamics.Comment: 4 pages, 4 figures, submited to Europhys. Let

In silico approach for the definition of radiomirnomic signatures for breast cancer differential diagnosis

Personalized medicine relies on the integration and consideration of specific characteristics of the patient, such as tumor phenotypic and genotypic profiling. BACKGROUND: Radiogenomics aim to integrate phenotypes from tumor imaging data with genomic data to discover genetic mechanisms underlying tumor development and phenotype. METHODS: We describe a computational approach that correlates phenotype from magnetic resonance imaging (MRI) of breast cancer (BC) lesions with microRNAs (miRNAs), mRNAs, and regulatory networks, developing a radiomiRNomic map. We validated our approach to the relationships between MRI and miRNA expression data derived from BC patients. We obtained 16 radiomic features quantifying the tumor phenotype. We integrated the features with miRNAs regulating a network of pathways specific for a distinct BC subtype. RESULTS: We found six miRNAs correlated with imaging features in Luminal A (miR-1537, -205, -335, -337, -452, and -99a), seven miRNAs (miR-142, -155, -190, -190b, -1910, -3617, and -429) in HER2+, and two miRNAs (miR-135b and -365-2) in Basal subtype. We demonstrate that the combination of correlated miRNAs and imaging features have better classification power of Luminal A versus the different BC subtypes than using miRNAs or imaging alone. CONCLUSION: Our computational approach could be used to identify new radiomiRNomic profiles of multi-omics biomarkers for BC differential diagnosis and prognosis

The ejection of triatomic molecular hydrogen ions H-3(+) produced by the interaction of benzene molecules with ultrafast laser pulses

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Polyethylene Glycol Epirubicin-Loaded Transcatheter Arterial Chemoembolization Procedures Utilizing a Combined Approach with 100 and 200 μm Microspheres: A Promising Alternative to Current Standards

PURPOSE:To report clinical effectiveness, toxicity profile, and prognostic factors of combined 100 μm ± 25 and 200 μm ± 50 epirubicin-loaded polyethylene glycol (PEG) microsphere drug-eluting embolic transcatheter arterial chemoembolization protocol in patients with hepatocellular carcinoma. MATERIALS AND METHODS: In this prospective, single-center, single-arm study with 18 months of follow-up, 36 consecutive patients (mean age 69.9 y ± 10.8; 26 men, 10 women; 54 naïve lesions) were treated. Embolization was initiated with 100 μm ± 25 microspheres, and if stasis (10 heart beats) was not achieved, 200 μm ± 50 microspheres were administered. Each syringe (2 mL) of PEG microsphere was loaded with 50 mg of epirubicin. Results were evaluated using Modified Response Evaluation Criteria In Solid Tumors with multidetector computed tomography/magnetic resonance imaging at 1, 3-6, 9-12, and 15-18 months. Toxicity profile was assessed by laboratory testing before and after the procedure. Complications were recorded. Postembolization syndrome (PES) was defined as onset of fever/nausea/pain after the procedure. Patient/lesion characteristics and treatment results were correlated with predicted outcome using regression analysis. Child-Pugh score was A in 86.1% of patients (31/36) and B in 13.9% (5/36). RESULTS: In 10 of 21 lesions, < 2 cm in diameter (47.5%) stasis was achieved with 100 μm ± 25 microspheres only, whereas all other lesions required adjunctive treatment with 200 μm ± 50 microspheres. Reported adverse events were grade 1 acute liver bile duct injury (3/39 cases, 7.7%) and PES (grade 2; 3/39 cases, 7.7%). Complete response (CR) at 1, 3-6, 9-12, and 15-18 months was 61.1%, 65.5%, 63.63%, and 62.5%. Objective response (CR + partial response) at 1, 3-6, 9-12, and 15-18 months was 83.3%, 65.85%, 63.63%, and 62.5%. No single factor (laboratory testing, etiology, patient status, hepatic status, tumor characteristics, administration protocol) predicted outcomes except for albumin level at baseline for CR (P < .05, odds ratio = 1.09). CONCLUSIONS: The combined microsphere sizing strategy was technically feasible and yielded promising results in terms of effectiveness and toxicity

The distance to the LMC cluster Reticulum from the K-band Period-Luminosity-Metallicity relation of RR Lyrae stars

We present new and accurate Near-Infrared J and Ks-band data of the Large Magellanic Cloud cluster Reticulum. Data were collected with SOFI available at NTT and covering an area of approximately (5 x 5) arcmin^2 around the center of the cluster. Current data allowed us to derive accurate mean K-band magnitudes for 21 fundamental and 9 first overtone RR Lyrae stars. On the basis of the semi-empirical K-band Period-Luminosity-Metallicity relation we have recently derived, we find that the absolute distance to this cluster is 18.52 +- 0.005 (random) +- 0.117 (systematic). Note that the current error budget is dominated by systematic uncertainty affecting the absolute zero-point calibration and the metallicity scale.Comment: 14 pages, 2 figures, ApJ accepted. Full resolution figure 1 on request ([email protected]