Hosing of a Long Relativistic Particle Bunch in Plasma

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge. Results have the main characteristics of a theoretical model, are relevant to other plasma-based accelerators and represent the first characterization of hosing.

Evaluation of growth adaptation of Cinnamomum camphora seedlings in ionic rare earth tailings environment

The root system is an important organ for nutrient uptake and biomass accumulation in plants, while biomass allocation directly affects essential oils content, which plays an essential role in plant growth and development and resistance to adverse environmental conditions. This study was undertaken to investigate the differences and correlation of biomass allocation, root traits and essential oil content (EOC), as well as the adaptations of camphor tree with different chemical types to the ionic rare earth tailing sand habitats. Data from 1-year old cutting seedlings of C. camphora showed that the biomass of C. camphora cuttings was mainly distributed in root system, with the ratio of root biomass 49.9-72.13% and the ratio of root to canopy 1.00-2.64. The total biomass was significantly positively correlated with root length (RL), root surface area (RSA) and dry weight of fine roots (diameter ≤ 2 mm) (P < 0.05). Root biomass and leaf biomass were negatively and positively with specific root length (SRL) and specific root surface area (SRSA), respectively. Leaf biomass presented a positive effect on EOC (P < 0.05), with the correlation coefficient of 0.808. The suitability sort of these camphor trees was as follows: C. camphora β-linalool, C. camphora α-linaloolII, C. camphora α-linaloolI being better adapted to the ionic rare earth tailings substrate, C. camphora citral being the next, and C. porrectum β-linalool and C. camphora borneol being the least adaptive. EOC played a positive role in the adaptation of C. camphora (R2 = 0.6099, P < 0.05). Therefore camphor tree with linalool type is the appropriate choice in the ecological restoration of ionic rare earth tailings. The study could provide scientific recommendations for the ecological restoration of ionic rare earth tailings area combined with industrial development.

The effects of ALDH2 Glu487Lys polymorphism on vasovagal syncope patients undergoing head-up tilt test supplemented with sublingual nitroglycerin

Background and objective

Head-up tilt test (HUTT) is clinically advantageous for diagnosing patients with vasovagal syncope (VVS). Nitroglycerin is mainly used as a stimulant during HUTT, and mitochondrial aldehyde dehydrogenase 2 (ALDH2) is involved in the metabolism of nitroglycerin (NTG). ALDH2 Glu487Lys polymorphism (ALDH2 rs671) is the most common variant in the East Asian population. This study aimed to assess the effects of ALDH2 rs671 on VVS patients undergoing HUTT supplemented with sublingual NTG (HUTT-NTG). 

Methods

Patients with recurrent VVS (at least 2 times) who were admitted to the syncope center of our hospital were enrolled. All VVS patients have undergone HUTT. The polymorphism of Glu487Lys gene of ALDH2 was measured by the DNA Microarray Chip Method. The results of HUTT-NTG of VVS patients with different ALDH2 genotypes were compared and their hemodynamic characteristics were assessed.

Results

A total of 199 VVS patients were enrolled, including 101 patients in the ALDH2*1/*1 group and 98 patients in the ALDH2*2 group. Among patients undergoing HUTT-NTG, 70.3% of patients in the ALDH2*1/*1 group and 68.4% of patients in the ALDH2*2 group were positive, and the difference between the two groups was not statistically significant (P = 0.77). The proportions of VASIS I, VASIS II, and VASIS III were 40.6%, 8.9%, and 20.8% in the ALDH2*1/*1 group, respectively, and the corresponding proportions in the ALDH2*2 group were 36.7%, 11.2%, and 20.4%, respectively. There was no statistically significant difference between the two groups (P = 0.91). The hemodynamic characteristics of different genotypes in VVS patients undergoing HUTT-NTG were compared, and no statistically significant difference was found. The median time of syncopal episode occurred after NTG administration in the ALDH2*1/*1 group was 6 min (interquartile range [IQR]: 5.0–9.0), and it was 6.0 min in the ALDH2*2 group (IQR: 4.25–8.0, P = 0.64).

Conclusion

ALDH2 Glu487Lys polymorphism did not affect the outcome of VVS patients undergoing HUTT-NTG, and no significant change in the hemodynamic characteristics of different genotypes was found.

Controlled Growth of the Self-Modulation of a Relativistic Proton Bunch in Plasma

A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton bunch can be seeded by the wakefields driven by a preceding electron bunch. SM timing reproducibility and control are at the level of a small fraction of the modulation period. With this seeding method, we independently control the amplitude of the seed wakefields with the charge of the electron bunch and the growth rate of SM with the charge of the proton bunch. Seeding leads to larger growth of the wakefields than in the instability case.

Transition between Instability and Seeded Self-Modulation of a Relativistic Particle Bunch in Plasma

We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of a long proton bunch in plasma. We show experimentally that, with sufficient initial amplitude [≥(4.1±0.4)  MV/m], the phase of the modulation along the bunch is reproducible from event to event, with 3%-7% (of 2π) rms variations all along the bunch. The phase is not reproducible for lower initial amplitudes. We observe the transition between these two regimes. Phase reproducibility is essential for deterministic external injection of particles to be accelerated.

[Mechanism of Ziyin recipe for treatment of ovulatory infertility: a network pharmacology-based study and clinical observations]

OBJECTIVE

To explore the mechanisms of Ziyin recipe for treatment of ovulatory infertility based on network pharmacology analysis and evaluate the clinical efficacy of this recipe.

OBJECTIVE

TCMSP, PubChem, Genecards, String, Swiss Target Prediction, and Uniprot databases were searched to identify all the action targets of Ziyin recipe and ovulatory infertility to construct the PPI network. Gene ontology (GO) and KEGG pathway enrichment analyses were performed and the "TCM-active ingredient-target-pathway" network was constructed using Cytoscape 3.6.0. We also designed a controlled clinical trial to verify the clinical effectiveness of Ziyin recipe. The patients were randomized into 2 groups to receive treatment with Western medicine including CC and HMG (control group) and additional treatment with Ziyin recipe, and the dosage of GN, follicular development days, E₂ level of a single dominant follicle on trigger day, ovulation rate, the rate of LUFS, and clinical pregnancy rate were compared between the two groups.

OBJECTIVE

We identified 22 active ingredients and 354 targets of action in Ziyin recipe, 791 targets of ovulatory infertility, and 96 common targets of action shared by Ziyin recipe and ovulatory infertility. According to Degree, the key targets included SRC, MAPK1, HSP90aa1, MAPK3, PTPN11, ESR1, Akt1, EGFR, NR3C1 and KNG1. Enrichment analysis of GO biological process showed that Ziyin recipe mainly focused on steroid hormonemediated signaling pathway, oxidation, reduction, and apoptosis. The most significantly enriched signaling pathways included PI3K-Akt signaling pathway, RAP1 signaling pathway, HIF-1 signaling pathway, estrogen signaling pathway, ovarian steroid production, and steroid hormone biosynthesis. The results of the clinical trial showed that Ziyin recipe significantly reduced the dose of GN, accelerated follicle development, increased E₂ level of single dominant follicle on the trigger day, and increased the cycle ovulation rate and pregnancy rate.

OBJECTIVE

The therapeutic effects of Ziyin recipe are probably mediated through different pathways to promote follicle development, thus improving ovulation rate and clinical pregnancy rate of infertile patients with ovulatory disorders.

Improving contraceptive and family planning awareness on a perinatal inpatient unit

Introduction

Unplanned pregnancies are a significant risk factor in perinatal mental health. They also have the potential to result in adverse health impacts for mother, baby and children into later in life. Women from disadvantaged backgrounds are less likely to access contraception. Women are more likely to on board health advice during pregnancy and post partum period due to high level of surveillance by health professionals.

Objectives

Our aim was for 90% of patients on Coombe Wood Mother and Baby Unit (MBU) to feel supported to make an informed decision about their contraception by October 2020.

Methods

A questionnaire was completed by fifteen inpatients at the Mother and Baby Unit over a 4 month period (April- August 2020) to assess areas around their pregnancy and contraceptives of choice. Contraceptive training was provided by a Sexual Health Specialist to staff across multiple disciplinaries on Coombe Wood MBU. Sexual Health discussion groups were delivered by doctors to inpatients on a monthly basis. A post-intervention questionnaire was given to patients.

Results

•53% of patients reported unplanned pregnancies. •40% of women felt lacking confidence in choosing the right contraceptive •The most frequent question asked during the sexual health groups was regarding hormonal contraceptives impacting on mental health. •By September 100% of patients felt they were able to make an informed decision about their contraception on discharge.

Conclusions

Facilitating women to make informed decisions regarding their contraception empowers them to gain autonomy, reduces the risks of physical and mental illness, improves the quality of life for mothers and babies.

Proton Bunch Self-Modulation in Plasma with Density Gradient

We study experimentally the effect of linear plasma density gradients on the self-modulation of a 400 GeV proton bunch. Results show that a positive or negative gradient increases or decreases the number of microbunches and the relative charge per microbunch observed after 10 m of plasma. The measured modulation frequency also increases or decreases. With the largest positive gradient we observe two frequencies in the modulation power spectrum. Results are consistent with changes in wakefields' phase velocity due to plasma density gradients adding to the slow wakefields' phase velocity during self-modulation growth predicted by linear theory.

Proton-driven plasma wakefield acceleration in AWAKE

In this article, we briefly summarize the experiments performed during the first run of the Advanced Wakefield Experiment, AWAKE, at CERN (European Organization for Nuclear Research). The final goal of AWAKE Run 1 (2013-2018) was to demonstrate that 10-20 MeV electrons can be accelerated to GeV energies in a plasma wakefield driven by a highly relativistic self-modulated proton bunch. We describe the experiment, outline the measurement concept and present first results. Last, we outline our plans for the future. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.

Coupling simulation of neutron kinetics core model with CFD of IPWR steam line break accident

In this paper, development of coupled codes using two-group neutron diffusion kinetics code and computational fluid dynamics (CFD) solver Fluent has been introduced. Way of coupling, time step control algorithm and spatial mesh overlays have been summarized in detail which are basic components and challenges of the coupling methodologies. The implement and verification of coupled code have been modeled on integral pressurized water reactor (IPWR) IP200 with hexagonal fuel assembly in the core and once-through steam generators. The steam line break core transient was analyzed in coupled code simulation of a core boundary conditions derived from system code simulation results. The results presented transient three-dimensional distribution of the key operation parameters such as reactor power and coolant temperature, also demonstrated the inherent safety features of IP200. The current work will bring about the ability to explore multi-scale and multi-dimensional safety transient evaluations and give more precise neutronics/thermal-hydraulics mapping.

Comparison of MAP method with classical methods for bandpass correction of white LED spectra

The bandwidth of a spectrometer is an important error-influencing factor in spectral measurement. To obtain accurate results, bandpass correction is an indispensable step in spectral data processing. To deal with such a problem, several methods have been proposed, including the differential operator method using a local polynomial approximation and the Richardson-Lucy method combined with a regularization. Here we employ a method based on the maximum a posteriori estimation. The efficiency of the method is verified through a large number of experiments on the spectra of white light-emitting diodes. By comparing the error of the reference spectrum, it was found that this method can effectively correct spectra, thus providing more accurate information for further analysis.

Experimental Observation of Proton Bunch Modulation in a Plasma at Varying Plasma Densities

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14}  electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15  MV/m) and reach over 300  MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

Analysis of operating characteristics of IPWR under natural circulation

Many integrated pressurized water reactor (IPWR) designs using natural circulation operation mainly to enhance their inherent safety. The operating characteristics of primary coolant are completely different without mechanical pumps. The designs and safety analysis of forced circulation reactors are widely researched, but the natural circulation characteristics of IPWR have not been well studied by literatures. The present work discussed the thermal-hydraulic characteristics of IPWR under natural circulation conditions by using the best estimate codes RELAP5. And the effect of system parameters on natural circulation characteristics of IPWR is also studied. The results show that, the primary coolant average temperature and steam pressure are two key parameters that affect the natural circulation stable operating load. The set value of primary coolant average temperature effects the core outlet temperature and the steam temperature, but the primary coolant flow is basically the same under different primary coolant average temperature but same load conditions. The smaller steam pressure is more conducive to produce superheated steam, but there is risk of two phase flow instability in OTSG secondary side. The rapid load change process under natural circulation indicating that the reactor has a good load tracking characteristics under natural circulation, but the rapid change of primary coolant temperature will cause oscillations in system parameters.

Acceleration of electrons in the plasma wakefield of a proton bunch

High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration^1–5, in which the electrons in a plasma are excited, leading to strong electric fields (so called ‘wakefields’), is one such promising acceleration technique. Experiments have shown that an intense laser pulse^6–9 or electron bunch^10,11 traversing a plasma can drive electric fields of tens of gigavolts per metre and above—well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies^5,12. The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage¹³. Long, thin proton bunches can be used because they undergo a process called self-modulation^14–16, a particle–plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN^17–19 uses high-intensity proton bunches—in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules—to drive a wakefield in a ten-metre-long plasma. Electron bunches are then injected into this wakefield. Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage²⁰ means that our results are an important step towards the development of future high-energy particle accelerators^21,22.

Electron acceleration to very high energies is achieved in a single step by injecting electrons into a ‘wake’ of charge created in a 10-metre-long plasma by speeding long proton bunches.

Dual-grating dielectric accelerators driven by a pulse-front-tilted laser

This paper investigates numerically dual-grating dielectric laser-driven accelerators driven by a pulse-front-tilted (PFT) laser, which extends the interaction length and boosts the electrons' energy gain. The optical system necessary to generate PFT laser beams with an ultrashort pulse duration of 100 fs is also studied in detail. Through two-dimensional particle-in-cell simulations, we show that such a PFT laser effectively increases the energy gain by (91±25) % compared to that of a normally incident laser with a waist radius of 50 μm for a 100-period dual-grating structure.

The effect of nerve mobilization exercise in patients with rheumatoid arthritis: a pilot study

Rheumatoid arthritis (RA) is an autoimmune disorder characterized by chronic inflammation of the joints. The neurogenic inflammatory mechanism plays an important role in the inflammatory process of RA, and pathological changes in neural tissues in RA have also been noted. We aim to investigate treatment of the nervous system to relieve joint pain and inflammation in RA. Nerve mobilization, a nervous system-specific therapeutic exercise, was applied on RA patients to determine the effect of nerve mobilization on joint inflammation. Twelve RA patients were recruited from the community and were randomised into an experimental and a control group. In the experimental group, the subjects were taught a set of nerve mobilization exercises while the subjects in the control group were taught a set of gentle joint mobilization exercises. Both groups were instructed to practice the exercises daily. After a 4-week period, their RA pain scale (RAPS) and pain scores were examined, as well as the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Subjects in the experimental group showed improvements in RAPS and pain scores after 4 weeks of nerve mobilization exercises, while CRP and ESR values remained unaffected. These preliminary data showed that nerve mobilization exercises might be beneficial in controlling joint pain in RA patients.

Bandwidth correction in the spectral measurement of light-emitting diodes

Light-emitting diodes (LEDs) are widely employed in industrial applications and scientific research. However, spectral distortions will occur due to the broadening effects of the spectrometer when an LED spectrum is obtained with a spectrometer. In this paper, a novel approach is put forward to correct bandwidth for an LED spectrum based on a Levenberg-Marquardt algorithm and He-Zheng model. We compare estimation errors of different LED spectra by using the proposed method along with the Richardson-Lucy method and differential operator approach. The experimental results show that the effect of the proposed approach is better than that of the other two methods.

Accurate wavelength calibration method for compact CCD spectrometer

Wavelength calibration is an important step in charge-coupled device (CCD) spectrometers. In this paper, an accurate calibration method is proposed. A model of a line profile spectrum is built at the beginning, followed by noise reduction, bandwidth correction, and automatic peak-seeking treatment. Experimental tests are conducted on the USB4000 spectrometer with a mercury-argon calibration light source. Compared with the traditional method, the results show that this wavelength calibration procedure obtains higher accuracy and the deviations are within 0.1 nm.

Xylaria hypoxylon Lectin as Adjuvant Elicited Tfh Cell Responses

Foot-and-mouth disease (FMD) caused by FMD virus (FMDV) is a major health and economic problem in the farming industry. Vaccination of livestock against this highly infectious viral disease is crucial, and inactivated FMD vaccine has been effective at controlling infection. However, accumulated data show that the inactivated vaccine generates weak immune responses and that the oil formulation results in undesirable side effects. Mushroom lectins have recently been shown to display adjuvant effects when incorporated into DNA vaccines. In this study, to enhance the cellular immune response of FMDV antigen (146S), C57BL/6 mice were immunized with 146S combined with Xylaria hypoxylon lectin (XHL). The oil formulation (146S/Oil) was served as control group. Strong humoral immune responses were elicited in mice immunized with 146S/XHL as shown by high 146S antigen-specific IgG levels, and also in 146S/Oil group. Interestingly, XHL in conjunction with inactivated FMD vaccine activated strong Th1 and Tc1 cell responses, especially Tfh cell responses, in immunized mice. XHL stimulated dendritic cell maturation by upregulating expression of major histocompatibility complex II (MHCII) molecules and co-stimulatory molecules CD40 and CD86 in immunized mice. No XHL-specific IgG or inflammatory factors were detected indicating the safety of XHL as an adjuvant. Taken together, these results suggest the effectiveness of XHL at inducing cellular immune responses and therefore confirm its suitability as an adjuvant for inactivated FMD vaccine.

Bolivian kindred with combined spinocerebellar ataxia types 2 and 10

BACKGROUND

Spinocerebellar ataxias (SCA) are a group of rare hereditary neurodegenerative disorders. Rare cases of two SCA mutations in the same individual have been reported in the literature, however, family descriptions are lacking.

AIMS

To characterize a family with combined SCA2 and SCA10 mutations.

MATERIALS & METHODS

Analysis of the clinical features and genetic findings of a Bolivian family expressing both SCA2 and SCA10 mutations.

RESULTS

The index case and his mother had both SCA2 and SCA10 mutations with a combined clinical phenotype of both disorders, including slow saccades (SCA2) and seizures (SCA10). The uncle of the index case had only an SCA10 mutation.

DISCUSSION

Although the presence of two SCA mutations in the same individuals may be coincidental, the low probability of having both mutations suggests that these mutations might be particularly prevalent in Bolivian population.

CONCLUSION

This is the first description of a family with two SCA mutations with affected subjects having a combined SCA2 and SCA10 phenotype.

Withaferin A attenuates lipopolysaccharide-induced acute lung injury in neonatal rats

Withaferin A (WFA) is an active compound from Withania somnifera and has been reported to exhibit a variety of pharmacological activities such as anti&mdash;inflammatory, immunomodulatory and anti&mdash;tumor properties. In the present study, we investigated the potential protective role of WFA on acute lung injury in neonatal rats induced by lipopolysaccharide (LPS). We found that WFA significantly attenuated the pathological changes of lungs induced by LPS injection. Administration with WFA obviously decreased pulmonary neutrophil infiltration accompanied with decreased MPO concentrations. WFA also reduced the expression of pro&mdash;inflammatory cytokines including MIP&mdash;2, TNF&mdash;&#945;, IL&mdash;1&#946; and IL&mdash;6. Meanwhile, the expression levels of anti&mdash;inflammatory mediators such as TGF&mdash;&#946;1 and IL&mdash;10 were significantly increased following WFA administration. Moreover, WFA protected LPS&mdash;treated rats from oxidative damage via up&mdash;regulation of TBARS and H2O2 concentrations and down&mdash;regulation of ROS contents. Taken together, the present study demonstrated that WFA administration attenuated LPS&mdash;induced lung injury through inhibition of inflammatory responses and oxidative stress.

Correlates of consistent condom use among female entertainment workers in Shanghai, China: a repeated measures analysis

Female entertainment workers (FEWs) in China are at increased risk of HIV and other sexually transmitted infections, but correlates of their risky sexual behaviour remain poorly understood. Using data from a series of four surveys, this paper employs repeated measures analysis to identify individual and social correlates of consistent condom use among FEWs in Shanghai. Results reveal that both individual cognitive and social influence factors are statistically significant in their bivariate relationships to consistent condom use with a stable or non-stable partner; only prevention motivation and perceived self-efficacy in condom use remain significant in the multiple regressions. When individual and social correlates are examined together, only peer support for condom use remains a significant and independent correlate of consistent condom use in sex with a non-stable partner. Behavioural intervention is urgently needed and should take a multilevel approach, emphasizing individual prevention motivation and behavioural skills training and promoting peer/social support.

Evaluation of viral heterogeneity using next-generation sequencing, end-point limiting-dilution and mass spectrometry

Hepatitis C Virus sequence studies mainly focus on the viral amplicon containing the Hypervariable region 1 (HVR1) to obtain a sample of sequences from which several population genetics parameters can be calculated. Recent advances in sequencing methods allow for analyzing an unprecedented number of viral variants from infected patients and present a novel opportunity for understanding viral evolution, drug resistance and immune escape. In the present paper, we compared three recent technologies for amplicon analysis: (i) Next-Generation Sequencing; (ii) Clonal sequencing using End-point Limiting-dilution for isolation of individual sequence variants followed by Real-Time PCR and sequencing; and (iii) Mass spectrometry of base-specific cleavage reactions of a target sequence. These three technologies were used to assess intra-host diversity and inter-host genetic relatedness in HVR1 amplicons obtained from 38 patients (subgenotypes 1a and 1b). Assessments of intra-host diversity varied greatly between sequence-based and mass-spectrometry-based data. However, assessments of inter-host variability by all three technologies were equally accurate in identification of genetic relatedness among viral strains. These results support the application of all three technologies for molecular epidemiology and population genetics studies. Mass spectrometry is especially promising given its high throughput, low cost and comparable results with sequence-based methods.

Abstract S1-8: Prolactin-humanized mice: an improved animal recipient for therapy response-testing of patient-derived breast cancer xenotransplants

Eighty percent of newly diagnosed breast cancer represents estrogen receptor(ER)-positive luminal subtypes. Many patients with luminal breast cancer develop antiestrogen resistant disease. It has historically been particularly difficult to establish ER-positive breast cancer lines from primary breast cancer in the laboratory or in mice. Murine and bovine prolactins, the major lactogens in current laboratory experimental in vivo and in vitro conditions, fail to activate human prolactin receptors because of species incompatibility. In fact, murine prolactin is a potent antagonist for human prolactin receptors. Because ER-positive, luminal breast cancers also express prolactin receptors, we hypothesized that lack of human lactogenic activity under experimental conditions selected against establishment of ER-positive breast cancer in the laboratory. We therefore genetically engineered mice to express physiological levels of human prolactin in place of mouse prolactin and backcrossed the mice for ten generations into the immunodeficient NSG strain. The resulting hPRL.NSG mice have a greatly improved take rate for ER positive, luminal type of breast cancer, suggesting key tumor-promoting roles for prolactin in luminal breast cancer. A panel of novel transplantable human breast cancer lines has been established in hPrl.NSG mice, the majority of which are ER-positive. The transplantable lines maintain key histopathological characteristics and expression of major marker proteins of the primary patient tumors. Intriguingly, initial tumor establishment and growth rates of breast cancer xenografts were consistently greater in the hPrl.NSG mice than in wildtype NSG mice. Furthermore, tumors grown in hPrl.NSG were more responsive to tamoxifen than size-matched tumors grown in wildtype NSG mice. At least two new tumor lines examined so far develop spontaneous distant metastases in hPrl.NSG mice, with evidence of prolactin-dependent progression of ER-positive disease. Collectively, these observations validate the hPrl.NSG mice as an improved recipient for preclinical modeling of human breast cancer in vivo, both for therapeutic targeting of prolactin-pathways and other growth and survival pathways, as well as overcoming anti-estrogen resistance.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S1-8.

Signal transducer and activator of transcription 3 (STAT3) gene polymorphisms are associated with treatment outcomes in acute myeloid leukemia

INTRODUCTION

In the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, STAT3 is one of the most prominent prognosis factors for cancer and leukemia. STAT3 activation might promote cellular transformation and therefore have an important role in human tumors. This study aimed to investigate the relationship between STAT3 polymorphisms and treatment response of acute myeloid leukemia (AML) in the Chinese population.

METHODS

Three single-nucleotide polymorphisms (SNPs) were tested in 130 patients with AML. Genomic DNA was isolated from peripheral blood and assayed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

RESULTS

The results of response to chemotherapy showed that there were strong relationships between unfavorable cytogenetics, partial remission (and even no remission), and GG genotype frequency in rs9909659 (P = 0.01 and 0.03). Patients younger than 45 years were associated significantly with GA/AA genotype (P = 0.01).

CONCLUSIONS

The results of this study suggest that the GG genotype in rs9909659 might confer increased resistance to standard chemotherapy.

What factors determine the severity of hepatitis A-related acute liver failure?

The reason(s) that hepatitis A virus (HAV) infection may progress infrequently to acute liver failure are poorly understood. We examined host and viral factors in 29 consecutive adult patients with HAV-associated acute liver failure enrolled at 10 sites participating in the US ALF Study Group. Eighteen of twenty-four acute liver failure sera were PCR positive while six had no detectable virus. HAV genotype was determined using phylogenetic analysis and the full-length genome sequences of the HAV from a cute liver failure sera were compared to those from self-limited acute HAV cases selected from the CDC database. We found that rates of nucleotide substitution did not vary significantly between the liver failure and non-liver failure cases and there was no significant variation in amino acid sequences between the two groups. Four of 18 HAV isolates were sub-genotype IB, acquired from the same study site over a 3.5-year period. Sub-genotype IB was found more frequently among acute liver failure cases compared to the non-liver failure cases (chi-square test, P < 0.01). At another centre, a mother and her son presented with HAV and liver failure within 1 month of each other. Predictors of spontaneous survival included detectable serum HAV RNA, while age, gender, HAV genotype and nucleotide substitutions were not associated with outcome. The more frequent appearance of rapid viral clearance and its association with poor outcomes in acute liver failure as well as the finding of familial cases imply a possible host genetic predisposition that contributes to a fulminant course. Recurrent cases of the rare sub-genotype IB over several years at a single centre imply a community reservoir of infection and possible increased pathogenicity of certain infrequent viral genotypes.

Healthcare-associated hepatitis C virus transmission among patients in an abdominal organ transplant center

BACKGROUND

De novo hepatitis C virus (HCV) infection among transplant patients is rarely recognized but can have severe consequences. We investigated the scope, source, and mode of HCV transmission within a transplant center after incident HCV infection was identified in 2 patients who had liver transplantation in late 2006.

METHODS

Patients were interviewed, and transplant logs, medical records, and staff practices were reviewed to identify opportunities for HCV transmission. Infection via receipt of blood or organs was evaluated. Molecular epidemiology was used to determine the relatedness between persons with incident and chronic HCV infection.

RESULTS

HCV from infected blood or organ donors was ruled out. Among the 308 patients who underwent transplant in 2006, no additional incident HCV infections were identified. Eighty-five (28%) had pre-transplant chronic HCV infection; 13 were considered possible HCV source patients based upon shared days on the inpatient unit, nursing assignment, or invasive procedures in common with incident HCV case-patients. Viral isolates from 1 HCV source patient and 1 incident case-patient were found to be highly related by quasispecies analysis, confirming patient-to-patient HCV transmission. Possible modes of transmission identified were the improper use of multidose vials, sharing of blood-contaminated glucometers, and touch contamination.

CONCLUSION

Sporadic transmission or endemic levels of HCV transmission might be overlooked in a setting with high HCV prevalence, such as liver transplant units, where multiple, repeated opportunities for patient-to-patient HCV transmission can occur. Surveillance through pre- and post-transplant screening is necessary to identify incident HCV infection in this setting. Constant, meticulous attention must be paid to maintaining aseptic technique and good infection control practices to eliminate HCV transmission opportunities.

Ex vivo-expanded natural CD4+CD25+ regulatory T cells synergize with host T-cell depletion to promote long-term survival of allografts

Foxp3(+)CD4(+)CD25(+) natural regulatory T (nT(reg)) cells have been shown in immunodeficient mice to suppress allograft rejection after adoptive cotransfer. We hypothesized that immunotherapy using ex vivo-expanded nT(reg) could suppress allograft rejection in wild-type mice. Donor alloantigen (alloAg) specificity of naive splenic nT(reg) was enriched in vitro by culturing with anti-CD3/CD28-coated Dynabeads plus bone marrow-derived dendritic cells (BM-DC) in the presence of interleukin (IL)-2 or IL-2 plus transforming growth factor (TGF)-beta. On average, 96.2% fresh CD4(+)CD25(+) nT(reg) were intracellular Foxp3(+). By d+20 in culture, 6.4% nT(reg) were Foxp3(+) following expansion with IL-2 alone, and 14.4% or 19.7% nT(reg) were Foxp3(+) when expanded with IL-2 plus 0.5 or 2.5 ng/mL TGF-beta, respectively. In vitro, alloAg-enriched, TGF-beta/IL-2-conditioned nT(reg) exerted stronger donor alloAg-specific suppression than cells with IL-2 alone in mixed lymphocyte reaction (MLR) assays. In vivo, alloAg-enriched, TGF-beta/IL-2-conditioned nT(reg) expressed high-level Foxp3 following infusion, effectively overcame acute rejection and induced long-term survival of donor but not third-party heart allografts in peritransplant host T-cell-depleted mice. Long-term surviving allografts were noted to possess Foxp3(+) graft-infiltrating cells of exogenous and endogenous origins. In conjunction with transient host T-cell depletion, therapeutic use of ex vivo-expanded nT(reg) may be a practical means of preventing acute allograft rejection.

304 HUMAN AUGMENTER OF LIVER REGENERATION TRANSGENIC OVINE EMBRYO DERIVED FROM SOMATIC CELL NUCLEAR TRANSFER

The aim of this research was to develop an efficient screening technique to detect transgenic ovine embryos using neomycin resistance (NeoR) and enhanced green fluorescence protein (EGFP) genes as genetic markers. A 0.8-kb fragment of the ovine β-lactoglobulin promoter sequence (BLG) and 1.8 kb of the human augmenter of liver regeneration (ALR) genomic sequence were derived by PCR amplification. These 2 fragments were inserted into the MCS of pGEM-7zf(+) plasmid; this vector was named p7Z-BA. The coding sequence of NeoR was derived by PCR amplification from the plasmid pIRES2-EGFP and was assembled into the MCS of the pIRES2-EGFP plasmid. The resultant vector (pNIE) contained a NeoR gene coding sequence and an EGFP coding sequence linked by an internal ribosome entry site (IRES) sequence downstream of the CMV promoter. The vector pNIE was excised as an NsiI-SspI fragment and inserted into the vector p7Z-BA. In the end, we had a vector named pNEA, which contained the NeoR gene and the EGFP gene regulated by a CMV promoter for expression in a non-tissue specific mode, and the human ALR gene regulated by the BLG promoter for expression specifically in mammary gland. Sheep fetal fibroblast (SFFB) cells were isolated by attachment of tissue pieces from the ear skin of a 1- to 2-month ovine fetus. Karyotypes of the cells at the third passage and after 15 passages were analyzed. The cells proliferated well and more than 72% of the cells maintained a diploid karyotype after 15 passages. Therefore, the SFFB cells are amenable for transgenic cloning manipulations. For transfection, third-passage SFFB cells at 70% confluency were transfected in a 100-mm dish with pNEA (0.5, 1.0, 2.0, 3.0, 5.0, and 7.0 µg) using Lipofectamine 2000 (2, 4, 6, 8, 10, and 12 µL; Invitrogen, Carlsbad, CA). Cells were checked 24 to 48 h after transfection under fluorescence microscopy for GFP expression, and G418 selection (800 µg mL–1) was applied at that time. After 2 weeks, selected colonies were counted and propagated in culture medium containing 300 µg mL–1 G418 for 2 to 3 passages and cryopreserved. A small portion of the cells was analyzed by PCR for gene integration. Bright green fluorescence could be detected 24 to 48 h after transfection. More colonies were selected when transfection parameters were 2 µg of DNA and 10 µL of Lipofectamine. The results of PCR detection showed that the foreign gene was integrated into the genome. A total of 612 oocytes were aspirated from 2- to 5-mm follicles of ovine ovaries collected from an abattoir; 78% of them were matured after 18 h in culture. Four hundred forty-three oocytes were enucleated, and 332 enucleated oocytes were treated for electrofusion with green fluorescence cells. Of these, 180 (54.2%) couplets were fused. A total of 172 reconstructed embryos were stimulated and cultured in vitro, 31 (18%) of which developed to the blastocyst stage, and 19 blastocysts expressed GFP. In conclusion, we established an effective method to select transgenic embryos formed by nuclear transfer using transfected donor cells.

Molecular confirmation of oysters as the vector for hepatitis A in a 2005 multistate outbreak

Numerous hepatitis A outbreaks were linked to the consumption of raw molluscan shellfish in the United States between 1960 and 1989. However, there had been no major molluscan shellfish-associated hepatitis A outbreaks reported in the United States for more than a decade (1989 to 2004). Beginning in late August 2005, at least 10 clusters of hepatitis A illnesses, totaling 39 persons, occurred in four states among restaurant patrons who ate oysters. Epidemiologic data indicated that oysters were the source of the outbreak. Traceback information showed that the implicated oysters were harvested from specific Gulf Coast areas. A voluntary recall of oysters was initiated in September. Hepatitis A virus (HAV) was detected in multiple 25-g portions in one of two recalled samples, indicating that as many as 1 of every 15 oysters from this source was contaminated. Comparing 315 nucleotides within the HAV VPl-2B region, 100% homology was found among four amplicons recovered from a total of six independent experiments of the implicated oysters, and an identical HAV sequence was detected in sera from all 28 patient serum specimens tested. Ten percent heterogeneity over 315 nucleotides (31 variants) was observed between the outbreak strain (subgenotype 1A) and an HM-175 strain (subgenotype 1B) used in the laboratory where the oysters were processed. To our knowledge, this investigation is the first in the United States to identify an HAV-identical strain in persons with hepatitis A as well as in the food that was implicated as the source of their infections.