Endoscopic ultrasound combined with submucosal saline injection for differentiation of T1a and T1b esophageal squamous cell carcinoma: a novel technique.

Endoscopic ultrasound (EUS) is the optimum method for investigation of early esophageal squamous cell carcinoma (ESCC). However, it is difficult to substage early ESCC as T1a or T1b. The aim of this study was to improve the staging accuracy of early ESCC by using EUS combined with submucosal saline injection (SSI). The study enrolled 15 patients with suspected early ESCC who were examined by EUS and subsequently by SSI combined with EUS. The patients then underwent endoscopic or surgical resection within 10 days. The accuracy of EUS staging (alone or following SSI) was evaluated and compared with the pathological results postoperatively. No severe complications of the SSI arose. EUS plus SSI easily distinguished the mucosa from the lesion and the submucosa because of the low-echoic saline-filled cushion in the submucosa. The accuracy of SSI combined with EUS for staging T1a or T1b was 86.7 %, which was better than that using EUS alone (60.0 %).

Complications of high intensity focused ultrasound for patients with hepatocellular carcinoma.

UNLABELLED: High intensity focused ultrasound (HIFU) is a noninvasive treatment modality that induces complete coagulative necrosis of a deep tumor through the intact skin. This study was conducted to analyze and evaluate the complications of HIFU for the treatments of hepatocellular carcinoma. A total of 59 patients with hepatocellular carcinoma, with a total of 72 lessions were enrolled in this study. Tumor size ranged from 2.5 to 14.0 cm in diameter, with a mean diameter of 7.6 cm. All patients had accepted HIFU treatment, and the median number of HIFU sessions was 1.32 per patient. RESULTS: The common complications from HIFU therapy were skin burns of various grades (eight cases of grade 1 skin burns, 48 of grade 2, three cases of 3), and pain in the treatment regions (15 cases of mild pain, 37 cases of moderate pain, 7 cased of severe pain). Other systemic complications were relatively rare and included fever (5 cases), hypertension (8 cases), supraventricular tachycardia (3 cases), mild impairment of hepatic function (48 cases), and mild mpairment of renal function (2 cases). Local damage consisted of acute cholecystitis (2 cases), hematuria (6 cases ), cholangiectasis (5 cases), light pericardial effusion (2 cases), impairment of peripheral nerves (10 cases), pleural effusion in the right thorax (3 cases), and impairment of vertebral column (1 case). No gastric or intestinal tract perforation, big vessel rupture, or hepatic rupture occurred. CONCLUSIONS: HIFU is a minimally invasive treatment for patients with hepatocellular carcinoma; however, there are some systemic and local complications that should be taken into consideration in evaluating HIFU for therapeutic use.

Spatially resolved high resolution x-ray spectroscopy for magnetically confined fusion plasmas (invited).

The use of high resolution x-ray crystal spectrometers to diagnose fusion plasmas has been limited by the poor spatial localization associated with chord integrated measurements. Taking advantage of a new x-ray imaging spectrometer concept [M. Bitter et al., Rev. Sci. Instrum. 75, 3660 (2004)], and improvements in x-ray detector technology [Ch. Broennimann et al., J. Synchrotron Radiat. 13, 120 (2006)], a spatially resolving high resolution x-ray spectrometer has been built and installed on the Alcator C-Mod tokamak. This instrument utilizes a spherically bent quartz crystal and a set of two dimensional x-ray detectors arranged in the Johann configuration [H. H. Johann, Z. Phys. 69, 185 (1931)] to image the entire plasma cross section with a spatial resolution of about 1 cm. The spectrometer was designed to measure line emission from H-like and He-like argon in the wavelength range 3.7 and 4.0 A with a resolving power of approximately 10,000 at frame rates up to 200 Hz. Using spectral tomographic techniques [I. Condrea, Phys. Plasmas 11, 2427 (2004)] the line integrated spectra can be inverted to infer profiles of impurity emissivity, velocity, and temperature. From these quantities it is then possible to calculate impurity density and electron temperature profiles. An overview of the instrument, analysis techniques, and example profiles are presented.

Rapid, absolute calibration of x-ray filters employed by laser-produced plasma diagnostics.

The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are detected using the high resolution EBIT Calorimeter Spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the x-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated x-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.

High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas.

A large radius, R=44.3 m, high resolution grating spectrometer (HRGS) with 2400 lines/mm variable line spacing has been designed for laser-produced plasma experiments conducted at the Lawrence Livermore National Laboratory Jupiter Laser Facility. The instrument has been run with a low-noise, charge-coupled device detector to record high signal-to-noise spectra in the 10-50 A wavelength range. The instrument can be run with a 10-20 microm wide slit to achieve the best spectral resolving power, approaching 1000 and similar to crystal spectrometers at 12-20 A, or in slitless operation with a small symmetrical emission source. We describe preliminary spectra emitted from various H-like and He-like low Z ion plasmas heated by 100-500 ps (full width at half maximum), 527 nm wavelength laser pulses. This instrument can be developed as a useful spectroscopy platform relevant to laboratory-based astrophysics as well as high energy density plasma studies.

A spatially resolving x-ray crystal spectrometer for measurement of ion-temperature and rotation-velocity profiles on the Alcator C-Mod tokamak.

A new spatially resolving x-ray crystal spectrometer capable of measuring continuous spatial profiles of high resolution spectra (lambda/d lambda>6000) of He-like and H-like Ar K alpha lines with good spatial (approximately 1 cm) and temporal (approximately 10 ms) resolutions has been installed on the Alcator C-Mod tokamak. Two spherically bent crystals image the spectra onto four two-dimensional Pilatus II pixel detectors. Tomographic inversion enables inference of local line emissivity, ion temperature (T(i)), and toroidal plasma rotation velocity (upsilon(phi)) from the line Doppler widths and shifts. The data analysis techniques, T(i) and upsilon(phi) profiles, analysis of fusion-neutron background, and predictions of performance on other tokamaks, including ITER, will be presented.

Investigation of the 2p_{32}-3d_{52} line emission of Au;{53+}-Au;{69+} for diagnosing high energy density plasmas.

Measurements of the L -shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from Fe-like Au53+ through Ne-like Au69+ . Using atomic data from the Flexible Atomic Code, we have identified strong 3d_{52}-->2p_{32} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found in the laser entrance hole of hot hohlraum radiation sources. We provide collisional-radiative calculations of the average ion charge Z as a function of temperature and density, which can be used to relate charge state distributions inferred from 3d_{52}-->2p_{32} emission features to plasma conditions, and investigate the effects of plasma density on calculated L -shell Au emission spectra.

Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII.

By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy establishing a benchmark for atomic calculations. The results show that the calculations consistently predict the cross section of the resonance line to be significantly larger than measured. The lower cross section accounts for several problems found when modeling solar and astrophysical Fe XVII spectra.

New benchmarks from tokamak experiments for theoretical calculations of the dielectronic satellite spectra of heliumlike ions.

Dielectronic satellite spectra of heliumlike argon, recorded with a high-resolution x-ray crystal spectrometer at the National Spherical Torus Experiment, were found to be inconsistent with existing predictions resulting in unacceptable values for the power balance and suggesting the unlikely existence of non-Maxwellian electron energy distributions. These problems were resolved with calculations from a new atomic code. It is now possible to perform reliable electron-temperature measurements and to eliminate the uncertainties associated with determinations of non-Maxwellian distributions.

Optic nerve glia secrete a low-molecular-weight factor that stimulates retinal ganglion cells to regenerate axons in goldfish.

The ability of lower vertebrates to regenerate an injured optic nerve has been widely studied as a model for understanding neural development and plasticity. We have recently shown that, in goldfish, the optic nerve contains two molecules that stimulate retinal ganglion cells to regenerate their axons in culture: a low-molecular-weight factor that is active even at low concentrations (axogenesis factor-1) and a somewhat less active polypeptide of molecular weight 10,000-15,000 (axogenesis factor-2). Both are distinct from other molecules described previously in this system. The present study pursues the biological source and functional significance of axogenesis factor-1. Earlier studies have shown that cultured goldfish glia provide a highly favorable environment for fish or rat retinal ganglion cells to extend axons. We report that the glia in these cultures secrete high levels of a factor that is identical to axogenesis factor-1 in its chromatographic properties and biological activity, along with a larger molecule that may coincide with axogenesis factor-2. Axogenesis factor-1 derived from either goldfish glial cultures or optic nerve fragments is a hydrophilic molecule with an estimated molecular weight of 700-800. Prior studies have reported that goldfish retinal fragments, when explanted in organ culture, only extend axons if the ganglion cells had been "primed" to begin regenerating in vivo for one to two weeks. However, axogenesis factor-1 caused the same degree of outgrowth irrespective of whether ganglion cells had been induced to regenerate new axons in vivo. Moreover, ganglion cells primed to begin regenerating in vivo continued to extend axons in culture only when axogenesis factor-1 was present. In summary, this study shows that glial cells of the goldfish optic nerve secrete a low-molecular-weight factor that initiates axonal regeneration from retinal ganglion cells.

Two factors secreted by the goldfish optic nerve induce retinal ganglion cells to regenerate axons in culture.

Unlike mammals, lower vertebrates can regenerate an injured optic nerve and other pathways of the CNS throughout life. We report here that in dissociated cell culture, goldfish retinal ganglion cells regenerate their axons in response to two factors derived from the sheath cells of the optic nerve. Axogenesis factor 1 (AF-1) is a small peptide (700-900 Da) that is inactivated by treatment with proteinase K but heat stable. A second factor, AF-2, is a polypeptide of ca 12 kDa. In the absence of these factors, dissociated retinal cells remained viable in serum-free, defined media for at least a week but showed little outgrowth, as visualized using the vital dye 5,6-carboxyfluorescein diacetate (5,6-CFDA). The addition of AF-1 induced up to 25% of cells in culture to extend processes > 75 microns in length by 6 d; AF-2 had a lesser but highly significant effect. To verify that neurite outgrowth was from retinal ganglion cells per se, we applied the lipophilic dye 4-Di-10-ASP to the optic tectum and allowed it to diffuse up the optic nerve for several days before culturing the retina. A far greater percentage of cells containing the dye showed axonal outgrowth than was observed from the overall cell population, indicating that ganglion cells are selective targets of the factors. The effects of AF-1 or AF-2 were not secondary to enhanced viability, since neither overall cell survival nor the number of retinal ganglion cells remaining in culture after 6 d was affected by the presence of the factors. The activity of AF-1 and AF-2 was not mimicked by several defined factors tested over a broad concentration range, for example, NGF, BDNF, NT-3, CNTF, taurine, retinoic acid, acidic or basic fibroblast growth factors. The concentration of AF-1 is considerably higher in CM than in optic nerve homogenates, suggesting that it is actively secreted; AF-2 has a similar concentration intra- and extracellularly. Insofar as AF-1 and AF-2 derive from cells of the optic nerve and act upon retinal ganglion cells, they are likely to be important in inducing optic nerve regeneration in vivo.