New measurements of high-momentum nucleons and short-range structures in nuclei

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Immunoregulation effect by overexpression of heme oxygenase-1 on cardiac xenotransplantation

OBJECTIVE

This study was designed to investigate the effect of the overexpression of heme oxygenase-1 (HO-1) on the immunoregulation in the model of abdominal cardiac xenotransplantation from the guinea pig to the rat.

MATERIALS AND METHODS

To increase the expression of HO-1, both donors and recipients were injected with heme through the abdomen before the operation. The donors (guniea pigs) and the recipients (Sprague-Dawley [SD] rats) were divided randomly into three groups: group A, the heart from a guinea pig transplanted into the abdomen of an SD rat; group B, the recipients were injected with Chinese cobra venom factor (CVF) into the abdomen (40 μg/kg and 60 μg/kg 24 hours later) prior to transplantation; group C, CVF + HO-1 high-expression group: donors and recipients were abdominally injected with heme (75 μmol/kg for 2 days before transplantation). The mean survival time (MST), pathological changes, the positive area of HO-1 in the grafted hearts, as well as the expressions of C-C chemokine receptor 5 (CCR5), intercellular adhesion molecule-1 (ICAM-1), and natural killer (NK) cell activity in recipients.

RESULTS

1. The MST was longest in group C treated with heme. 2. The pathologic changes of hyperacute rejection were showed on the donor heart in group A, while delayed xenograft rejection changes took place on donor heart in other groups. 3. Compared with group B, The HO-1 positive area in the donor hearts of group C was significantly higher. (P < .05). 4. The lever of ICAM-1 and CCR5 in the peripheral blood of recipients (pg/mL) was attenuated in group C injected with heme. 5. Compared with group B, the activity of NK cell in the peripheral blood of recipients was much lower in group C (P < .05).

CONCLUSION

The MST was prolonged by increasing expressions of HO-1, but acute vascular rejection was not completely overcome. Activation of vascular endothelial cells could be decreased by strengthening the expression of HO-1. NK cell activity was weakened by reinforced expression of HO-1.

Design and feasibility studies of a stationary digital breast tomosynthesis system

Studies have shown that digital breast tomosynthesis (DBT) can improve breast cancer diagnosis by reconstructing 3D images. However, DBT scanners based on rotation gantry prolong the imaging time and reduce spatial resolution due to motion comparing with the regular two-view mammography. To obtain three dimension reconstruction images and maintain the high image quality of conventional mammography, we proposed a prototype stationary digital breast tomosynthesis system (s-DBT). The proposed s-DBT system acquires projection images without mechanical movement. The core component of the s-DBT system is a specially designed spatially distributed multi-beam x-ray tube based on the carbon nanotube field emission x-ray technology. The multi-beam x-ray source array enables collection of all projection images from different viewing angles without mechanical motion. Preliminary results show the s-DBT system can achieve a scan time comparable to the regular two-view mammography, and improve the spatial resolution comparing with rotating gantry DBT.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

PPARα agonist prevented the apoptosis induced by glucose and fatty acid in neonatal cardiomyocytes

OBJECTIVE

We investigated the effect of peroxisome proliferator activator receptors α (PPARα) on cardiomyocyte apoptosis induced by glucose and fatty acid, and if high glucose levels could increase fatty acid-induced apoptosis.

METHODS

Cardiomyocytes were maintained in Dulbecco's Modified Eagle Medium and divided into 5 groups: Group N (control Group); Group G (exposed to 25.5 mmol/l glucose); Group L (exposed to 5 mmol/l glucose, fatty acid); Group H (exposed to 25.5 mmol/l glucose and fatty acid); Group I (exposed to 25.5 mmol/l glucose, fatty acid and Wy14643). Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling. Immunocytochemistry staining detected PPARα's expressing, and western blotting detected PPARα and nuclear factor κB's (NF-κB) protein level.

RESULTS

Exposure to fatty acid resulted in a significant increase of cardiomyocytes apoptosis, with the extension of NF-κB formation, whereas exposure to 25.5 mmol/l glucose had no influence on the apoptosis rate. However, combination with fatty acid and high glucose concentration had induced more apoptosis with the up-regulation of NF-κB formation. The fatty acid and glucose-induced effects were improved by Wy14643, with down-regulation of NF-κB formation.

CONCLUSION

These results suggested that in neonatal cardiomyocytes, fatty acid and glucose in combination with fatty acid induced apoptosis via NF-κB formation and activation of apoptosis pathways; glucose in combination with fatty acid induce more apoptosis rate for the more NF- κB formation, activation of the PPARα can reverse such apoptosis effect. The results also suggest that gluco-lipotoxicity may play a central role in the development of diabetic cardiomyopathy, and PPARα-agonist may be an effective drug in treating the diabetic cardiomyopathy.

Stationary digital breast tomosynthesis with distributed field emission X-ray tube

Tomosynthesis requires projection images from different viewing angles. Using a distributed x-ray source this can be achieved without mechanical motion of the source with the potential for faster image acquisition speed. A distributed x-ray tube has been designed and manufactured specifically for breast tomosynthesis. The x-ray tube consists of 31 field emission x-ray sources with an angular range of 30°. The total dose is up to 100mAs with an energy range between 27 and 45 kVp. We discuss the source geometry and results from the characterization of the first prototype. The x-ray tube uses field emission cathodes based on carbon nanotubes (CNT) as electron source. Prior to the manufacturing of the sealed x-ray tube extensive testing on the field emission cathodes has been performed to verify the requirements for commercial tomosynthesis systems in terms of emission current, focal spot size and tube lifetime.

Precise extraction of the induced polarization in the 4He(e,e'p)3H reaction

We measured with unprecedented precision the induced polarization P(y) in (4)He(e,e'p)(3)H at Q(2)=0.8 and 1.3  (GeV/c)(2). The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are overestimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin-independent charge-exchange term in the latter calculation.

A tritherapy combination of a fusion protein vaccine with immune-modulating doses of sequential chemotherapies in an optimized regimen completely eradicates large tumors in mice

Tumor-induced immunosuppression plays a critical role in both impeding tumor-specific immune responses and limiting the effects of cancer immunotherapy. Analyses of regulatory cells recruited during the growth of the E7-expressing tumor, TC-1, revealed a high percentage of regulatory T cells (Tregs) as well as myeloid-derived suppressor cells (MDSCs) in spleens and tumors. In this study, we proposed that treatment with immune-modulating doses of cyclophosphamide (CTX) and all-trans retinoic acid (ATRA) would result in a beneficial tumor microenvironment with the suppression of Tregs and MDSCs and, thus, enhance the effect of a human papillomavirus protein vaccine. Our results showed that CTX preconditioning and persistent ATRA treatment along with the vaccine achieved long-term survival and induced long-term memory responses. However, the effect of the antitumor response sharply declined when the tritherapy was initiated after the optimal therapeutic time. The more intensive regimen could rescue the effect of the tritherapy accompanied by the decreased percentage of Tregs and MDSCs in spleens and tumors. Besides, a favorable host environment was created by the reduced secretion of interleukin-10 and 6 and vascular endothelial growth factor (VEGF) in the tumor niche and decreased the expression of phosphorylation-signal transducer and activator of transcription 3 of TC-1 tumors. Our data shed light on the immune-modulating doses of sequential chemoimmunotherapeutic strategy targeting not only the tumor but also its microenvironment, which suggests a potential clinical benefit for the immunotherapy of HPV-associated malignancies.

The role of p27(Kip1) phosphorylation at serine 10 in the migration of malignant glioma cells in vitro

Until recently, Cip/Kip members were almost solely viewed as nuclear proteins with a principal function of inhibiting cyclin/cyclin dependent kinase (CDK) activity and hence, inhibiting cell cycle progression. P27(Kip1) (hereafter p27) belongs to the Cip/Kip family that binds and inhibits all the cyclin/CDK complexes, thus often referred as a universal CDK inhibitor. However, emerging studies now suggest that Cip/Kip proteins play additional roles outside of the nucleus. Indeed, previous reports have linked p27 to the regulation of actin dynamics and cell migration. In this study, we constructed a model of migration-activated glioma cells by using the migration-stimulating substrate, a kind of ECM, laminin in vitro. Our results present evidence that laminin drives glioma cell migration without altering cell proliferation. Further, actively migrating cells which expressioned high phosphorylation of p27 at Ser10, and induced its cytoplasmic localization. In this process, Jab1 and CRM1 were also involved. Thus phosphorylation of p27 at Ser10 is necessary for both cytoplasmic localization and induction of cell migration. These observations solidified a genetic role of p27 in cell migration and this was independent of cyclin/CDK inhibition. Eventually, we transiently transfected p27S10A into T98G glioma cells, found that overexpression of p27S10A inhibited cell migration but not cell proliferation. These data linked phosphorylation of p27 at Ser10 and cell motility. Therefore, the major phosphorylation site at Ser10 of p27 played a pivotal role in the migration of malignant glioma cells.

Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Scaling of the F2 structure function in nuclei and quark distributions at x>1

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for x>1, which is sensitive to short-range contributions to the nuclear wave function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.

Polarization transfer in the 4He(e,e'p)3H reaction at Q2=0.8 and 1.3 (GeV/c)2

Proton recoil polarization was measured in the quasielastic 4He(e,e'p)3H reaction at Q{2}=0.8 and 1.3  (GeV/c){2} with unprecedented precision. The polarization-transfer coefficients are found to differ from those of the 1H(e,e'p) reaction, contradicting a relativistic distorted-wave approximation and favoring either the inclusion of medium-modified proton form factors predicted by the quark-meson coupling model or a spin-dependent charge-exchange final-state interaction. For the first time, the polarization-transfer ratio is studied as a function of the virtuality of the proton.

E-cadherin negatively regulates neoplastic growth in non-small cell lung cancer: role of Rho GTPases

Non-small cell lung cancers (NSCLC) that express the cell surface adhesion protein E-cadherin may carry a better prognosis than E-cadherin-negative tumors. Here, we found substantial inhibition of anchorage-independent growth in soft agar and cell migration in each of four NSCLC lines stably transfected with E-cadherin. The inhibitory effects were independent of the EGFR and beta-catenin/Wnt-signaling pathways. However, E-cadherin expression was associated with an adhesion-dependent reduction in the activity of Rho family proteins, RhoA in two lines and Cdc42 in the other two. The reduction of RhoA activity was dependent on DLC-1 Rho-GAP and p190 Rho-GAP and associated with an increase in a membrane-associated p190 Rho-GAP/p120 Ras-GAP complex. In parental cells with high levels of RhoA-GTP, siRNA-mediated knock-down of RhoA reduced cell migration and agar growth in a manner analogous to E-cadherin. In parental cells with high levels of Cdc42-GTP, transfection of a Cdc42 dominant-negative mutant reduced cell growth and migration similarly to cells expressing E-cadherin. Thus, E-cadherin can negatively regulate cell proliferation and migration in NSCLC by reducing the level of the predominant active form of Rho family protein, RhoA or Cdc42. These proteins can be considered downstream effectors of E-cadherin and might represent therapeutic targets in some NSCLC.

SERIAL NONRIGID VASCULAR REGISTRATION USING WEIGHTED NORMALIZED MUTUAL INFORMATION

Vascular registration is a challenging problem with many potential applications. However, registering vessels accurately is difficult as they often occupy a small portion of the image and their relative motion/deformation is swamped by the displacements seen in large organs such as the heart and the liver. Our registration method uses a vessel detection algorithm to generate a vesselness image (probability of having a vessel at any given voxel) which is used to construct a weighting factor that is used to modify the intensity metric to give preference to vascular structures while maintaining the larger context. Therefore, our proposing method uses fully data-driven calculated weights and needs no prior knowledge for the weight calculation. We applied our method to the registration of serial MRI lamb images obtained from studies on tissue engineered vascular grafts and demonstrate encouraging performance as compared to non-weighted registration methods.

Distributed source x-ray tube technology for tomosynthesis imaging

Tomosynthesis imaging requires projection images from different viewing angles. Conventional systems use a moving xray source to acquire the individual projections. Using a stationary distributed x-ray source with a number of sources that equals the number of required projections, this can be achieved without any mechanical motion. Advantages are a potentially faster image acquisition speed, higher spatial and temporal resolution and simple system design. We present distributed x-ray sources based on carbon nanotube (CNT) field emission cathodes. The field emission cathodes deliver the electrons required for x-ray production. CNT emitters feature a stable emission at high current density, a cold emission, excellent temporal control of the emitted electrons and good configurability. We discuss the use of stationary sources for two applications: (i) a linear tube for stationary digital breast tomosynthesis (sDBT), and (ii) a square tube for on-board tomosynthesis image-guided radiation therapy (IGRT). Results from high energy distributed sources up to 160kVp are also presented.

Intrathecal sufentanil decreases the median effective dose (ED50) of intrathecal hyperbaric ropivacaine for caesarean delivery

BACKGROUND

The addition of opioid to local anaesthetics has become a well-accepted practice of spinal anaesthesia for caesarean delivery. Successful caesarean delivery anaesthesia has been reported with the use of a low dose of intrathecal hyperbaric ropivacaine coadministered with sufentanil. This prospective, double-blinded study determined the median effective dose (ED50) of intrathecal hyperbaric ropivacaine with and without sufentanil for caesarean delivery, to quantify the sparing effect of sufentanil on the ED50 of intrathecal hyperbaric ropivacaine.

METHODS

Sixty-four parturients undergoing elective caesarean delivery with combined spinal-epidural anaesthesia were randomized into two groups: Group R (ropivacaine) and Group RS (ropivacaine plus sufentanil 5 microg). The initial dose of ropivacaine was 13 mg in Group R and 10 mg in Group RS. The effective dose was defined as a T(6) level attained within 10 min and no supplemental epidural anaesthetic required during surgery. Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the dose of ropivacaine for the next patient using an up-down sequential allocation.

RESULTS

The ED50 of intrathecal ropivacaine was 11.2 mg [confidence interval (CI) 95%: 11.0-11.6] in Group R vs. 8.1 mg (CI 95%: 7.8-8.3) in Group RS. Motor block was markedly more intense in Group R than in Group RS, and the incidence of shivering was lower in Group RS than in Group R. There were no differences in the onset time of sensory block or motor block, in the incidence of hypotension, nausea and vomiting.

CONCLUSION

Intrathecal sufentanil 5 microg produced a 28% reduction of ED50 of intrathecal hyperbaric ropivacaine for caesarean delivery.

Abdominal compartment syndrome associated with capillary leak syndrome after liver transplantation

Orthotopic liver transplantation was performed in a 49-year-old man with metastatic liver sarcoma. After surgery, both abdominal compartment syndrome (ACS) and capillary leak syndrome (CLS) developed. Exploratory laparotomy and colon exteriorization were performed. Five days later, a diagnosis of severe CLS was established, and hydroxyethyl starch was infused to prevent leakage of albumin. The patient gradually recovered over 3 weeks. Awareness of ACS and CLS is important to improve outcome because early diagnosis and immediate therapy are essential. Bladder pressure is a key factor in diagnosing ACS, and pressure of 35 mm Hg is an indication for decompressive laparotomy. During the early stage of CLS, hydroxyethyl starch but not albumin should be used to alleviate edema and hypoalbuminemia.