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cAMP signals are received and transmitted by multiple isoforms of cAMP-dependent protein kinases, typically determined by their specific regulatory subunits. In the brain the major regulatory isoform RIIbeta and the RII-anchor protein, AKAP150 (rat) or 75 (bovine), are differentially expressed. Cortical neurons express RIIbeta and AKAP75; conversely, granule cerebellar cells express predominantly RIalpha and RIIalpha. Cortical neurons accumulate PKA catalytic subunit and phosphorylated cAMP responsive element binding protein very efficiently into nuclei upon cAMP induction, whereas granule cerebellar cells fail to do so. Down-regulation of RIIbeta synthesis by antisense oligonucleotides inhibited cAMP-induced nuclear signaling in cortical neurons. Expression in cerebellar granule cells of RIIbeta and AKAP75 genes by microinjection of specific expression vectors, markedly stimulated cAMP-induced transcription of the lacZ gene driven by a cAMP-responsive element promoter. These data indicate that the composition of PKA in cortical and granule cells underlies the differential ability of these cells to transmit cAMP signals to the nucleus.

Previous studies showed that the subtype 2 of somatostatin receptors (sstr2) is generally expressed by soft tissue sarcomas.Using reverse transcription-polymerase chain reaction (RT-PCR), the present study evaluated the expression of sstr mRNA in 31 human intermediate and malignant soft tissue tumors. In 8 patients somatostatin receptor scintigraphy was performed to detect soft tissue tumor sites and visualize in vivo sstr expression.Somatostatin receptors were identified in 84% of the tumors analyzed by RT-PCR analysis. sstr1 and sstr2 were the receptors most frequently detected. Somatostatin receptor scintigraphy was able to identify primary and/or metastatic sites in 7 out of 8 patients, with an overall sensitivity per site of 87%. Concordant results were found between in vitro and in vivo techniques.The wide expression of sstrs in soft tissue tumors suggest a relevant role for these receptors in diagnosis and may have therapeutic applications.

This study was aimed to identify possible intracellular effectors of the somatostatin (SST) antiproliferative activity, in PCCl3 thyroid cells.To prove the involvement of r-PTPeta in SST's effect, we studied th proliferative activity of subclones of PCCl3 cells that do or do not express this PTP.SST inhibited PCCl3 TSH+insulin-dependent cell proliferation through the induction of a phosphotyrosine phosphatase (PTP) activity, detected using the synthetic substrate pNPP (+150%, p0.01). Conversely, PCCl3 cells stably expressing the v-mos oncogene (PCmos) were completely insensitive to SST antiproliferative effects due to the incapability of SST to increase PTP activity, that correlated with the abolishment of the expression of the receptor-like PTP, r-PTPeta. In the cells in which r-PTPeta was transfected (PCmos/ PTPeta) SST inhibited cell proliferation showing a dose-dependence similar to that observed in PCCl3 cells. Conversely, the transfection of a catalytically inactive mutant of r-PTPeta did not restore the responsivity to SST. Also in PCmos/PTPeta cells SST, treatment increased membrane PTP activity.SST inhibition of PCC13 cell proliferation requires the activation of r-PTPeta.

N-terminally truncated amyloid-beta (Abeta) peptides are present in early and diffuse plaques of individuals with Alzheimer's disease (AD), are overproduced in early onset familial AD and their amount seems to be directly correlated to the severity and the progression of the disease in AD and Down's syndrome (DS). The pyroglutamate-containing isoforms at position 3 [AbetaN3(pE)-40/42] represent the prominent form among the N- truncated species, and may account for more than 50% of Abeta accumulated in plaques. In this study, we compared the toxic properties, fibrillogenic capabilities, and in vitro degradation profile of Abeta1-40, Abeta1-42, AbetaN3(pE)-40 and AbetaN3(pE)-42. Our data show that fibre morphology of Abeta peptides is greatly influenced by the C-terminus while toxicity, interaction with cell membranes and degradation are influenced by the N- terminus. AbetaN3(pE)-40 induced significantly more cell loss than the other species both in neuronal and glial cell cultures. Aggregated AbetaN3 (pE) peptides were heavily distributed on plasma membrane and within the cytoplasm of treated cells. AbetaN3(pE)-40/42 peptides showed a significant resistance to degradation by cultured astrocytes, while full- length peptides resulted partially degraded. These findings suggest that formation of N-terminally modified peptides may enhance beta-amyloid aggregation and toxicity, likely worsening the onset and progression of the disease.

MuSES is a multi-sensor experimental package designed to operate onboard a rover to perform the electromagnetic prospection of planetary soils. The package consists of three instruments that, using different electromagnetic methods, provide the in situ measurements of the dielectric constant and conductivity of the subsurface, in several bands of frequencies (from 100Hz to 1GHz) at different ranges of depth (from 0 to 60 m). The package is capable to detect subsurface water in solid and/or liquid phases and to determine the electromagnetic stratigraphy of the subsoil.

The amyloid β protein precursor (AβPP) is sequentially processed by β- and γ-secretases to generate the Aβ peptide. The biochemical path leading to Aβ formation has been extensively studied since extracellular aggregates of amyloidogenic forms of Aβ peptide (Aβ42) are considered the culprit of Alzheimer's disease. Aside from its pathological relevance, the biological role of AβPP proteolysis is unknown. Although never previously described, cleavage of AβPP by γ-secretase should release, together with Aβ, a COOH-terminal AβPP Intracellular Domain, herein termed AID. We have now identified AID-like peptides in brain tissue of normal control and patients with sporadic Alzheimer's disease and demonstrate that AID acts as a positive regulator of apoptosis. Thus, overproduction of AID may add to toxic effect of Aβ42 aggregates and further accelerate neurodegeneration.

Somatostatin and its analogs are active in the inhibition of the proliteration of sst receptor positive endocrine neoplasms, however their activity and mechanism in non-endocrine tumors is not clear. Somatostatin effectively inhibited the growth of a Kaposi's sarcoma xenograft in nude mice, yet in vitro the tumor cells did not express any known somatostatin receptors and were not growth inhibited by somatostatin. Histological examination revealed limited vascularization in the somatostatin treated tumors as compared to the controls. Somatostatin was a potent inhibitor of angiogenesis in an in vivo assay. In vitro, somatostatin inhibited endothelial cell growth and invasion. Migration of monocytes, important mediators of the angiogenic cascade, was also inhibited by somatostatin. Both cells types expressed somatostatin receptor mRNAs. These data demonstrate that somatostatin is a potent anti-tumor angiogenesis compound directly affecting both endothelial and monocytic cells. The debated function of somatostatin in tumor treatment and the design of therapeutic protocols should be reexamined considering these data.

About one third of patients operated on for a "single" cerebral metastasis diagnosed by CT scan have probably more than one lesion. In fact, Gd-DTPA enhanced MRI has proved to be more sensitive than CT in detecting the number of cerebral metastases, reducing the number of patients candidate to surgery.Thirty-five patients with a CT scan picture of a single cerebral neoplasm of presumable metastatic nature performed a Gd-DTPA enhanced cerebral MRI. In 25 cases MR images confirmed a single lesion, while in other 10 (28.6%) showed a number of metastases ranging from 2 to 6. In order to assess the utility of MRI in surgical selection of patients and then to reconsider the concept of operability limited to single brain metastases only, we compared the survival of the 25 cases who preoperatively performed MRI (MRI group) with that of other 25 consecutive patients operated on in pre-MR era (during a 24-month period), with a CT picture of single cerebral metastasis (non-MRI group).The median survival was 36 +/- 5 weeks for MRI group and 40 +/- 15 for non-MRI group. The Kaplan-Meier product-limit survival analysis and the log-rank test do not reveal any statistically significative difference of survival between the two groups.Even if the number of patients is limited for definitive considerations, our preliminary results seem to suggest that the further selection of surgical cases obtained with MRI could not impact significatively the survival. Therefore, in selected patients with multiple cerebral metastases a surgical treatment could be reasonable.

In this paper the analysis and design of the transmission line for the International Thermonuclear Experimental Reactor system is presented. In particular, three types of innovative microwave devices have been studied, all of them working in oversized waveguides: a high power combiner/splitter, different bends, and mode filters. Each of them has been analyzed in relevant specific settings and conditions. The whole system is designed in order to allow both a very high power capability, low transmission losses, and very limited generation of higher order modes. © 2010 IEICE Institute of Electronics Informati.

"Electromagnetic Band-Gap (EBG) materials can be successfully employed to improve the performances of antennas [1], [2]. When used as planar reflectors, as substrates, or as high-impedance ground-planes, they are able to eliminate the drawbacks of conducting ground-planes, to prevent the propagation of surface waves, also allowing a lowering of the antenna profile, and to improve the radiation efficiency. In EBG resonator antennas, instead, an EBG is employed as a superstrate on a primary radiator, backed with a ground plane, and its main effect is a considerable increase in the directivity [3]. It is also possible to obtain a highly-directive antenna by embedding a source in an EBG working near its band-gap edge, thanks to the limited angular propagation allowed."

The impedance of a coaxial probe, feeding an Electromagnetic Bandgap (EBG) structure conceived for radiation shaping,is studied from the theoretical and numerical viewpoints. The EBG medium is a square arrangement of dielectric cylinders placed in a parallel-plate waveguide, where a suitable lattice mode is excited. A semi-analytical model is developed and used to derive an approximate, closed-form expression of the probe resistance. The model is based on a modal expansion in Floquet harmonics, on which a current distribution is projected according to the Lorentz reciprocity theorem to derive the amplitude of lattice modes propagating right above the bandgap along lattice axes. The dependence of probe impedance on lattice parameters is then investigated with the numerical simulations of a finite-element method, which is also used to validate the developed model. A broad set of parametric analyses is presented, showing that the reactive part weakly depends on probe position, cylinder radius and permittivity, while the heights of probe and parallel-plate waveguide play a major role in determining the resonance condition. As to the probe resistance, it decreases with cylinder radius and permittivity and decreases with probe and waveguide heights. The derived analytical formula correctly reproduces such functional dependences and its calculation is immediate, revealing its usefulness in antenna design. Matching issues are heuristically and experimentally approached by examples, demonstrating that the proposed work can be effectively employed to improve the electrical performance of EBG antennas with an embedded source.

This paper presents an analytical and numerical investigation of the radiation features of an interesting class of electromagnetic bandgap (EBG) structures excited by an electric line source. The radiation from two-dimensional (2-D) lattices made with lossless dielectric cylinders, typically optimized by using the Bloch analysis of the corresponding 2-D photonic crystals, are originally investigated in terms of leaky waves. A thorough modal analysis of open waveguides, composed by a finite number of periodic chains of circular dielectric rods, is presented that shows a multiplicity of bound and leaky modes. Two radiation windows are identified and the relevant directive features are described in terms of properly excited dominant leaky modes. The possible excitation of higher order leaky modes and guided modes has been carefully considered, by also capturing the relevant residue contributions in a nonspectral representation of the excited fields. The final results on radiated fields by realistic truncated structures, obtained by ad-hoc software as well as full-wave EM simulators, are in excellent agreement with those predicted by the proposed leaky-wave approach.

A full-wave numerical approach for the analysis of bounded and leaky modes in periodic chain composed of both lossless and lossy 2-D cylindrical inclusions is proposed. An effective method based on the lattice sums technique is adapted to the analysis of modes with complex propagation wavenumbers, thus allowing for the appropriate choice of the spectral determination for each spatial harmonic. Periodic chains of both dielectric and silver nanocylinders are studied and the relevant modal phase and attenuation constants are rigorously calculated in all the different propagation regimes, including bound and radiative regions as well as plasmonic behaviors.

This letter shows that the position of a source inside an electromagnetic bandgap material determines how the emission is shaped and focused. Two degenerate electromagnetic configurations, allowed by a square lattice at a given frequency, can be selectively excited by placing the feeding point in specific locations within the building block of the periodic structure. In this way, the radiated energy can be directed toward defined focusing directions, without need to change the lattice and its dispersion diagram. A practical application, where embedded emitters selectively drive single lattice modes, is presented, showing that such a mechanism may open the way to important uses in the microwave domain, e.g., for cell splitting, smart antennas, and multiple-input-multiple-output technology, as well as in terahertz communications and optical applications.