Proton source size measurements in the eA-->e'ppX reaction

Two-proton correlations at small relative momentum q were studied in the eA(3He,4He,C,Fe)-->e(')ppX reaction at E(0)=4.46 GeV using the CLAS detector at Jefferson Lab. The enhancement of the correlation function at small q was found to be in accordance with theoretical expectations. Sizes of the emission region were extracted, and proved to be dependent on A and on the proton momentum. The size of the two-proton emission region for He was measured in eA reactions for the first time.

Construction of a BAC library of Korean ginseng and initial analysis of BAC-end sequences

We estimated the genome size of Korean ginseng (Panax ginseng C.A. Meyer), a medicinal herb, constructed a HindIII BAC library, and analyzed BAC-end sequences to provide an initial characterization of the library. The 1C nuclear DNA content of Korean ginseng was estimated to be 3.33 pg (3.12 x 10(3) Mb). The BAC library consists of 106,368 clones with an average size of 98.61 kb, amounting to 3.34 genome equivalents. Sequencing of 2167 BAC clones generated 2492 BAC-end sequences with an average length of 400 bp. Analysis using BLAST and motif searches revealed that 10.2%, 20.9% and 3.8% of the BAC-end sequences contained protein-coding regions, transposable elements and microsatellites, respectively. A comparison of the functional categories represented by the protein-coding regions found in BAC-end sequences with those of Arabidopsis revealed that proteins pertaining to energy metabolism, subcellular localization, cofactor requirement and transport facilitation were more highly represented in the P. ginseng sample. In addition, a sequence encoding a glucosyltransferase-like protein implicated in the ginsenoside biosynthesis pathway was also found. The majority of the transposable element sequences found belonged to the gypsy type (67.6%), followed by copia (11.7%) and LINE (8.0%) retrotransposons, whereas DNA transposons accounted for only 2.1% of the total in our sequence sample. Higher levels of transposable elements than protein-coding regions suggest that mobile elements have played an important role in the evolution of the genome of Korean ginseng, and contributed significantly to its complexity. We also identified 103 microsatellites with 3-38 repeats in their motifs. The BAC library and BAC-end sequences will serve as a useful resource for physical mapping, positional cloning and genome sequencing of P. ginseng.

Heat shock factor regulates VDUP1 gene expression

The vitamin D3 up-regulated protein 1 (VDUP1) is identified as interacting protein with thioredoxin (TRX) and functions as a natural antagonist of TRX. Its expression is regulated by various stresses including ROS, UV, and heat shock. In the present study, we observed an inducible expression of VDUP1 in Bosc cells by high density and serum deprivation cultures. To determine transcription factors associated with the induction of VDUP1 by stresses, the promoter region of VDUP1 was cloned. Through reporter assays with plasmids having various deletion of its promoter region and analysis of putative cis-elements, heat shock factor element (HSE) was identified. The deletion of HSE abolished transcriptional activity of VDUP1 promoter by stresses and the binding of heat shock factor (HSF) to HSE was confirmed by gel-shift and supershift assays using nuclear extracts prepared from stressed Bosc cells. Also, the enforced expression of HSF or heat shock increased the transcription of endogenous VDUP1. These imply that HSF is an important transcription factor involved in up-regulation of VDUP1 expression by stresses such as high density and serum deprivation cultures.

Two-nucleon momentum distributions measured in 3He(e,e'pp)n

We have measured the 3He(e,e'pp)n reaction at 2.2 GeV over a wide kinematic range. The kinetic energy distribution for "fast" nucleons (p>250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back to back with little momentum along the three-momentum transfer, indicating that they are spectators. Calculations by Sargsian and by Laget also indicate that we have measured distorted two-nucleon momentum distributions by striking one nucleon and detecting the spectator correlated pair.

Observation of an exotic baryon with S=+1 in photoproduction from the proton

The reaction gamma p-->pi(+)K(-)K(+)n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state with strangeness S=+1 and mass M=1555+/-10 MeV/c(2) was observed in the nK(+) invariant mass spectrum. The peak's width is consistent with the CLAS resolution (FWHM=26 MeV/c(2)), and its statistical significance is (7.8+/-1.0)sigma. A baryon with positive strangeness has exotic structure and cannot be described in the framework of the naive constituent quark model. The mass of the observed state is consistent with the mass predicted by the chiral soliton model for the Theta(+) baryon. In addition, the pK(+) invariant mass distribution was analyzed in the reaction gamma p-->K(-)K(+)p with high statistics in search of doubly charged exotic baryon states. No resonance structures were found in this spectrum.

Observation of an exotic S = +1 baryon in exclusive photoproduction from the deuteron

In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K(+)n invariant mass spectrum. The peak is at 1.542+/-0.005 GeV/c(2) with a measured width of 0.021 GeV/c(2) FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2+/-0.6)sigma. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups.

Measurement of the proton spin structure function g1(x,Q2) for Q2 from 0.15 to 1.6 GeV2 with CLAS

Double-polarization asymmetries for inclusive ep scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH3 target in the CLAS detector. The polarized structure function g(1)(x,Q2) was extracted throughout the nucleon resonance region and into the deep inelastic regime, for Q(2)=0.15-1.64 GeV2. The contributions to the first moment Gamma(1)(Q2)= integral g(1)(x,Q2) dx were determined up to Q(2)=1.2 GeV2. Using a parametrization for g(1) in the unmeasured low x regions, the complete first moment was estimated over this Q2 region. A rapid change in Gamma(1) is observed for Q2<1 GeV2, with a sign change near Q(2)=0.3 GeV2, indicating dominant contributions from the resonance region. At Q(2)=1.2 GeV2 our data are below the perturbative QCD evolved scaling value.

Macrophage inhibitory cytokine-1 induces the invasiveness of gastric cancer cells by up-regulating the urokinase-type plasminogen activator system

In our search for genes associated with gastric cancer progression, we identified macrophage inhibitory cytokine-1 (MIC-1), a member of the transforming growth factor beta superfamily, as an overexpressed gene in gastric tumor tissues. Expression analysis of MIC-1 in gastric tumor tissues revealed a specific expression in gastric cancer cells, and this expression level was well correlated with invasive potential in various human gastric cancer cell lines. Stable transfection of MIC-1 into SNU-216, a human gastric cancer cell line, significantly increased its invasiveness. The overexpression of MIC-1 into SNU-216 cells significantly increased the activity of urokinase-type plasminogen activator (uPA), and the expressions of uPA and urokinase-type plasminogen activator receptor (uPAR). Similarly, the stimulation of gastric cancer cell lines with purified recombinant MIC-1 dose-dependently increased cell invasiveness, uPA activity, and uPA and uPAR expression. However, MIC-1 did not significantly suppress the proliferation of gastric cancer cell lines. We also found that the stimulation of human gastric cell lines with recombinant MIC-1 strongly induced activation of mitogen-activated protein kinase kinase-1/2 and extracellular signal-regulated kinase-1/2. Additional analysis revealed that PD98059, a selective inhibitor of mitogen-activated protein kinase kinase-1/2, suppressed not only gastric cancer cell invasiveness and uPA activity, but also the mRNA expressions of uPA and uPAR, as induced by recombinant MIC-1. Our results indicate that MIC-1 may contribute to the malignant progression of gastric cancer cells by inducing tumor cell invasion through the up-regulation of the uPA activation system via extracellular signal-regulated kinase-1/2-dependent pathway.

Measurement of ep-->e' ppi+ pi- and baryon resonance analysis

The cross section for the reaction ep-->e(')ppi(+)pi(-) was measured in the resonance region for 1.4<W<2.1 GeV and 0.5<Q2<1.5 GeV(2)/c(2) using the CLAS detector at Jefferson Laboratory. The data show resonant structures not visible in previous experiments. The comparison of our data to a phenomenological prediction using available information on N(*) and Delta states shows an evident discrepancy. A better description of the data is obtained either by a sizable change of the properties of the P13(1720) resonance or by introducing a new baryon state, not reported in published analyses.

First measurement of transferred polarization in the exclusive ep-->e'K+Lambda--> reaction

The first measurements of the transferred polarization for the exclusive e-->p-->e(')K+Lambda--> reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q2 from 0.3 to 1.5 (GeV/c)(2), W from 1.6 to 2.15 GeV, and over the full K+ center-of-mass angular range. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A nonrelativistic quark-model interpretation of our data suggests that the ssmacr; quark pair is produced with spins predominantly antialigned. Implications for the validity of the most widely used quark-pair creation operator are discussed.

Self-focusing of intense laser pulses in a clustered gas

We report the self-focusing of intense laser pulses in gases composed of atomic clusters. This is in strong contrast to beam spreading owing to ionization-induced refraction commonly observed in nonclustered gases. The effect is explained in terms of the ensemble average transient polarizability of the heated clusters as they explode in response to the intense pulse.

Time-resolved explosion of intense-laser-heated clusters

We investigate the femtosecond explosive dynamics of intense laser-heated argon clusters by measuring the cluster complex transient polarizability. The time evolution of the polarizability is characteristic of competition in the optical response between supercritical and subcritical density regions of the expanding cluster. The results are consistent with time-resolved Rayleigh scattering measurements, and bear out the predictions of a recent laser-cluster interaction model [H. M. Milchberg, S. J. McNaught, and E. Parra, Phys. Rev. E 64, 056402 (2001)]].

Influence of 3D-CRT pelvic irradiation on outcome in prostate cancer treated with external beam radiotherapy

PURPOSE

The role of pelvic irradiation (PRT) in the treatment of prostate cancer remains unclear. We reviewed our institution's experience with three-dimensional conformal external beam radiotherapy (3D-CRT) during the prostate-specific antigen era to determine the influence of PRT on the risk of biochemical recurrence in patients who have a predicted risk of lymph node involvement.

METHODS AND MATERIALS

Between March 1985 and January 2001, 1832 patients with clinically localized prostate cancer were treated with definitive 3D-CRT. All treatments involved CT planning to ensure coverage of the intended targets. Treatment consisted of prostate-only treatment, prostate and seminal vesicle treatment, or PRT of lymph nodes at risk followed by a boost. To create relatively homogenous analysis groups, each patient's percentage of risk of lymph node (%rLN) involvement was assigned by matching the patient's T stage, Gleason score, and initial prostate-specific antigen level to the appropriate value as described in the updated Partin tables. Three categories of %rLN involvement were defined: low, 0-5%; intermediate, >5-15%; and high, >15%. Biochemical recurrence was defined as the first occurrence of either the American Society for Therapeutic Radiology and Oncology consensus definition of prostate-specific antigen failure or the initiation of salvage hormonal therapy for any reason.

RESULTS

The risk status (%rLN) could be determined for 709 low-risk, 263 intermediate-risk, and 309 high-risk patients. The actuarial freedom from biochemical recurrence (bNED) and the log-rank test for the similarity of the control and treatment survival functions are reported for each risk group. Multivariate analysis demonstrated a statistically significant benefit for the entire population treated with PRT, with a relative risk reduction of 0.72 (95% confidence interval 0.54-0.97). Although the multivariate analysis could not determine the patient population that would most benefit from PRT, the beneficial effect appeared to be most pronounced within the intermediate-risk group. Univariate analysis revealed that the intermediate-risk patients treated with PRT had an improved 2-year bNED rate, 90.1% vs. 80.6% (p = 0.02), and both low-risk and high-risk patients treated with PRT had statistically similar 2-year bNED rates compared with those who did not receive it.

CONCLUSION

Pelvic 3D-CRT appears to improve bNED in prostate cancer patients. Additional studies are needed to elucidate the %rLN population for which this treatment should be recommended.

Resonant self-trapping of high intensity Bessel beams in underdense plasmas

We present a comprehensive report based on recent work [Phys. Rev. Lett. 84, 3085 (2000)] on resonant self-trapping and enhanced absorption of high power Bessel beams in underdense plasmas. The trapping resonance is strongly dependent on initial gas pressure, Bessel-beam geometry, and laser wavelength. Analytic estimates, and simulations using a one-dimensional Bessel-beam-plasma interaction code consistently explain the experimental observations. These results are for longer, moderate intensity pulses where the self-trapping channel is induced by laser-heated plasma thermal pressure. To explore the extension of this effect to ultrashort, intense pulsed Bessel beams, we perform propagation simulations using the code WAKE [Phys. Rev. E 53, R2068 (1996)]. We find that self-trapping can occur as a result of a plasma refractive index channel induced by the combined effects of relativistic motion of electrons and their ponderomotive expulsion.

Development of bovine oocytes reconstructed with different donor somatic cells with or without serum starvation

We conducted this study to examine whether serum starvation in culture contributes to better development of bovine reconstructed oocytes and to evaluate which serum-starved somatic cell is the most effective for cloned calf production. In Experiment 1, donor cells of four different types (cumulus cells, ear fibroblasts, oviduct cells and uterine cells) were either serum-starved or not before fusion with enucleated oocytes, and reconstructed oocytes were further cultured for 168 h. Regardless of serum starvation, cumulus cells or ear fibroblasts yielded higher (P < 0.05) rates of fusion than other cells (62.6-69.3 versus 33.3-38.7%). In the serum-starved group, the first cleavage after reconstruction was significantly increased in cumulus cells and ear fibroblasts, compared with oviduct cells (93.4-94.3 versus 78.8-86.0%), and oocytes reconstructed with either of these yielded more blastocysts than oocytes reconstructed with oviduct or uterine cells (40.6-43.8 versus 20.3-19.0%). We observed a similar pattern in the non-starved group, but we found a significant increase in blastocyst formation was found only in cumulus cells compared with other donor cells (42.6 versus 15.4-27.7%). Overall comparison showed that serum starvation increased the rates of cleavage and development to the blastocyst stage, but we found a statistical significance only in the cleavage rate (80.0 versus 89.5%). In Experiment 2, we transferred randomly selected 59 blastocysts that were developed from oocytes reconstructed with serum-starved cells to 44 synchronised recipients. Of those recipients, 23 became pregnant on Day 60 after transfer (52.3%) and 12 (27.3%) delivered cloned calves. The mean gestation length and birth weight was 275 +/- 8 days and 39.6 +/- 15.6 kg, respectively. Although there was no significant difference among donor cells, blastocysts that were derived from oocytes reconstructed with ear fibroblasts yielded the highest rates of pregnancy (50.0%) and delivery (27.3%). In conclusion, serum starvation is effective for improving preimplantation development of oocytes reconstructed with cumulus or ear fibroblast cells and it may positively influence on obtaining better pregnancy outcome.

Q2 Dependence of quadrupole strength in the gamma*p --> Delta(+)(1232) --> p pi(0) transition

Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.

First measurement of the double spin asymmetry in (-->)e(-->)p-->e(prime)pi(+)n in the resonance region

The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data.

Measurement of the superluminal group velocity of an ultrashort Bessel beam pulse

The superluminal group velocity of an ultrashort optical Bessel beam pulse is measured over its entire depth of field, corresponding to approximately 2x10(4) optical wavelengths. The method used is to measure the traveling ionization front induced by the pulse.

Sodium nitroprusside selectively induces apoptotic cell death in the outer retina of the rat

Sodium nitroprusside (SNP), an NO donor, was studied for its effects on apoptosis in rat retinal neurons. TUNEL-positive cells were observed in the outer nuclear layer (ONL), but not in the inner retina after SNP treatment. Inner retinal neurons died by necrosis. No photoreceptor cells were found in the ONL after seven days. Immunoblotting confirmed that neurnal NO synthase expression increased up to 5 days (approximately 170% of control levels), and then declined by 7 days, suggesting that NO induces apoptosis in the ONL, and that inner retinal neurons die by necrosis due to glutamate from damaged photoreceptors.

A case of mediastinal angiomyolipoma

Angiomyolipoma is a common tumor of the kidney but has rarely been found in the mediastinum. We report a case of angiomyolipoma of the posterior mediastinum in a 62-year-old woman. She experienced exertional dyspnea and intermittent cough at admission. Computed tomography indicated a tumor located at the left paravertebral and upper posterior mediastinum and MRI imaging demonstrated a mass with low signal intensity in T1-weighted image at T4-5 level. Thoracotomy was done for surgical removal of the tumor and histologic examination revealed a mesenchymal tumor composed of mature fat, capillaries and smooth muscle fibers. The tumor was immunohistochemically positive for CD34 and factor-VIII (for vascular component) smooth muscle actin (for smooth muscle component) and S-100 protein (for fat component). There have been four case reports about mediastinal angiomyolipoma, namely three Japanese cases and one French case. It is suggested that angiomyolipoma could be considered for the differential diagnosis of mediastinal tumors.

In vitro antimicrobial activity of a chitooligosaccharide mixture against Actinobacillus actinomycetemcomitans and Streptococcus mutans

The purpose of this study was to evaluate the in vitro antibacterial activity of a chitooligosaccharide mixture (MW 2000-30000 Da) with a deacetylation degree of 91.5% against two representative oral pathogens, Actinobacillus actinomycetemcomitans and Streptococcus mutans. A 0.1% concentration of the chitooligosaccharides (derived from the exoskeletons of marine crustaceans) was used to estimate antibacterial activity. Approximately 2 logcolony forming units (CFU)/ml of A. actinomycetemcomitans were inactivated by 0.1% chitosan after 30 min, while 120 min exposure inactivated about 4.5 logCFU/ml of this organism. In contrast, the level of inactivation against S. mutans was less than 0.5 logCFU/ml after an exposure of up to 120 min. Electron microscopy showed that the exposure of A. actinomycetemcomitans to the chitooligosaccharides resulted in the disruption of cell membranes and that it could be considered for the treatment of periodontal diseases associated with A. actinomycetemcomitans.

Characterization and large-scale expression of the recombinant cysteine proteinase from adult Clonorchis sinensis

Cysteine proteinases play important roles in the pathogenesis of several parasitic infections and have been proposed as targets for the structure-based approach of drug design. As the first step toward applying this strategy to design inhibitors as antiparasitic agents for Clonorchis sinensis, we overexpressed and characterized the 24-kDa cysteine proteinase from adult worms. First, the partial cysteine proteinase gene from C. sinensis was cloned by performing reverse transcription polymerase chain reaction (RT-PCR) with degenerate oligonucleotide primers derived from conserved cysteine proteinase sequences. The 5' and the 3' regions of the cysteine proteinase gene were amplified using the PCR protocol for the rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The cDNA has an open reading frame of 981 bp, and the deduced amino acid sequence shares similarity with the cathepsin L-like cysteine proteinases from Schistosoma mansoni, Paragonimus westermani metacercaria, Fasciola hepatica, and human cathepsin L by 52%, 47%, 34%, and 29%, respectively. The cysteine proteinase was then overexpressed in the yeast Pichia pastoris as an active enzyme on a large-scale basis (19.7 mg/L). The active recombinant enzyme was purified from culture media using a Ni2+-NTA-agarose affinity column and gel filtration chromatography. This 24-kDa recombinant protein exhibited a substrate preference for Z-Phe-Arg-AMC (benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amino-4-methyl-coumarin) compared with Z-Arg-Arg-AMC, and the activity was inhibited by E-64 (L-trans-epoxysuccinylleucylamido(4-quanidino)butane).

Recording of optical near fields in remote locations by near-field holography

We propose a method of near-field recording in a space that is quite apart from the original source (generator) of optical near fields. The method is based on the recently developed technique of near-field holography. Experiments based on our method have shown that near fields that originate from sub-diffraction-limit-sized objects can be stored in a photorefractive crystal 2 mm apart from the crystal surface, resulting in the retrieval of sub-diffraction-limit-sized spots. This means that our scheme can provide a method for multilayer (stackwise) near-field storage and, thus, contribute to a significant enhancement of the storage capacity of near-field optical memory.

N-acetylcysteine induces cell cycle arrest in hepatic stellate cells through its reducing activity

Activation of hepatic stellate cells (HSC) has been identified as a critical step in hepatic fibrogenesis and is regulated by several factors including cytokines and oxidative stress. However, the molecular mechanism for HSC inactivation is not well understood. We investigated an N-acetyl-L-cysteine (NAC)-mediated signaling pathway involved in HSC inactivation. NAC, which acting through its reducing activity, induced cell arrest at G1 via the mitogen-activated protein kinase (MAPK) kinase (MEK)/MAPK pathway in a Ras-independent manner. The sustained activation of this extracellular signal-regulated kinase induced the expression of p21(Cip1/WAF1), a cell cycle-dependent kinase inhibitor, and mediated cell growth arrest through the Sp1 transcription activator-dependent mechanism. These effects of NAC were all reversed by treatment of HSC with MEK inhibitor PD98059 followed by culturing HSC on type I collagen-coated flasks. The collagen-mediated suppression of NAC-induced arrest may be due to an overriding of the cell cycle arrest through an acceleration of integrin-induced cell growth. NAC action is actually dependent on modulating the redox states of cysteine residues of target proteins such as Raf-1, MEK, and ERK. In conclusion, an understanding of the NAC signaling pathway in HSC should provide the theoretical basis for clinical approaches using antioxidant therapies in liver fibrosis.

Predicting the rotationally neutral state of the femur by comparing the shape of the contralateral lesser trochanter

The rotationally neutral state of the femur was measured by comparing the shape of the contralateral lesser trochanter in 100 adults. Three observers predicted a position presumed to be neutral by comparing the shape of the neutrally positioned contralateral lesser trochanter previously recorded by C-arm image intensification. The mean (SD) angular discrepancy between the neutral point and the predicted angle was 3.4 degrees (+/- 2.4) without interobserver variation (P = .87). Seventy-seven percent indicated the value within 4 degrees, and none of the observations exceeded 15 degrees. These findings suggest the outline of the contralateral lesser trochanter may be a useful reference during surgical treatment of femoral fractures to minimize rotational deformity.