The p53-Bak apoptotic signaling axis plays an essential role in regulating differentiation of the ocular lens

The tumor suppressor p53 is a master regulator of apoptosis and also plays a key role in cell cycle checking. In our previous studies, we demonstrated that p53 directly regulates Bak in mouse JB6 cells (Qin et al. 2008. Cancer Research. 68(11):4150) and that p53-Bak signaling axis plays an important role in mediating EGCG-induced apoptosis. Here, we demonstrate that the same p53-Bak apoptotic signaling axis executes an essential role in regulating lens cell differentiation. First, during mouse lens development, p53 is expressed and differentially phosphorylated at different residues. Associated with p53 expression, Bak is also significantly expressed during mouse lens development. Second, human p53 directly regulates Bak promoter and Bak expression in p53 knockout mice (p53-/-) was significantly downregulated. Third, during in vitro bFGF-induced lens cell differentiation, knockdown of p53 or Bak leads to significant inhibition of lens cell differentiation. Fourth, besides the major distribution of Bak in cytoplasm, it is also localized in the nucleus in normal lens or bFGF-induced differentiating lens cells. Finally, p53 and Bak are co-localized in both cytoplasm and nucleus, and their interaction regulates the stability of p53. Together, these results demonstrate for the first time that the p53-Bak apoptotic signaling axis plays an essential role in regulating lens differentiation.

Efficacy of Pyrimethamine/Sulfadoxine versus Chloroquine for the Treatment of Uncomplicated Falciparum Malaria in Children Aged Under 5 Years

The children aged under 5 years from vast African areas badly suffer from falciparum malaria and many of them die of this disease. Therapeutic efficacy of anti-malaria drugs, especially pyrimethamine-sulfadoxine (PS) and chloroquine (CQ) to falciparum malaria is frequently evaluated and reported in recent 10 years. Unfortunately, to date, these widespread materials and researches have not been systematically collected and analyzed. In our study, two investigators were employed to widely and independently gather researches on efficacy of PS vs. CQ mono-therapy of falciparum malaria in children aged below 5 years in unpublished and published databases. Meta-analyses were conducted in categories of PS group and CQ group respectively. Pooled OR of PS vs. CQ was 0.11 (95%CI, 0.05-0.24). PS showed higher therapeutic efficacy to falciparum malaria in less-than-5-year children than CQ. Random model was chosen to analyze for the heterogeneity existence between different studies. Subgroup analyses were performed, but heterogeneity was still presented. Heterogeneity might be caused by different resistance of falciparum malaria to PS and CQ in different settings. Malaria type associated with parasite species, basic information of PS and CQ, and PS & CQ resistant malaria control measures were demonstrated and discussed respectively in detail in this article.

Serum uric acid is associated with dietary and lifestyle factors in elderly women in suburban Guangzhou in Guangdong province of south China

OBJECTIVES

To estimate the prevalence of hyperuricemia and lifestyle risk factors for hyperuricemia in elderly women.

DESIGN

Cross-sectional study.

SETTING

The suburban area of Guangzhou, Guangdong province, China.

PARTICIPANTS

The study included 856 Chinese women aged 60 to 102 years who received their annual health examinations in the suburban area of Guangzhou, south China in 2002.

MEASUREMENTS

Information on anthropometric measurements and lifestyle factors were obtained via a questionnaire processed by the attending physicians or nurses. Blood biochemistry was performed after subjects fasted for 8-14 h. Unconditional logistic regression analysis was used to investigate associations between hyperuricemia, meat intake quintiles, physical activity quintiles, and alcohol intake quintiles.

RESULTS

The prevalence of hyperuricemia in the studied population was 12.01%. Alcohol, meat and seafood consumption; being overweight or obese; hypertension; and abnormal triglyceride levels were strongly associated with a higher prevalence of hyperuricemia. Physical activity was inversely related to the prevalence of hyperuricemia. The odds ratios for hyperuricemia for quintiles of physical activity were 1.00, 0.74, 0.72, 0.63, and 0.55 (P<0.01).

CONCLUSIONS

Our data suggest that the prevalence of hyperuricemia is high in elderly women in suburban Guangzhou in Guangdong province of South China. Obesity, meat and seafood intake and alcohol consumption are associated with a higher prevalence of hyperuricemia, whereas daily physical activity is inversely related to the prevalence of hyperuricemia.

SU-E-J-159: Electromagnetic Tracking during 4DCT

PURPOSE

Real-time, electromagnetic tumor tacking during 4DCT is an unsolved problem. The underlying problem is due to eddy current magnetic fields generated within the conducting surfaces in response to the source's alternating magnetic fields.To solve this problem, we developed a method to separate the source from the background fields, which can be measured with simple search coil sensors, such as those used by the Calypso (Seattle, WA) tracking system.

METHOD

We modeled the environment using ANSYS Maxwell electromagnetic simulation software. The gantry was modeled as a 5 mm thick × 1.2 m diameter stainless-steel cylinder, with variable length. The transponder solenoid was modeled as a 10 mm × 1 mm conducting cylinder, with azimuth directed current, which was assumed to have a frequency range of 300-500 kHz. The search coil configuration was assumed to be a 5 × 5 array of 5-7 cm square current loops with 6.7 cmseparation. An algorithm based on free space calculations and measurements was developed to calculate the solenoid position within the cylinder, in the presences of relatively large eddy magnetic fields that were generated at the same frequency as the source.

RESULTS

Of the various methods and sensor configurations investigated, we found a method that localized the transponder solenoid within 1 mm over all solenoid locations and gantry lengths. We also found that gradient techniques did not significantly increase localization accuracy as expected. Complex solutions were found but not suitable for rapid clinical implementation.

CONCLUSIONS

This method can be used to localize a Calypso® Beacon transponder during 4DCT to accurately track tumor positions. Furthermore, the method was based on inexpensive search coils with comparable dimensions to preserve the source-sensor distance. The next task is to create a system and investigate clinical implementation.

First Report of Chilli ringspot virus on Chili Pepper in China

Viral diseases have been a major limiting factor in the production of chili pepper (Capsicum chinense Jacp. cv. Yellow Lantern) in Hainan Province, China. In a 2009 disease survey, we found heavily infected fields of chili pepper exhibiting typical viral disease symptoms in three counties in Hainan. Total RNA was extracted from leaves of 14 randomly sampled plants and used as templates for reverse transcription (RT)-PCR using a pair of primers (forward 5' CGTAGACAACACACTCATGGT 3', reverse 5' GTTTTCCCAGTCACGAC(T)₁₆ 3') that were originally designed to detect Chilli veinal mottle virus (ChiVMV) (2). PCR fragments of 1.6 kb were amplified from the diseased but not the symptom-free samples and were subsequently sequenced. While most samples were found to be infected with ChiVMV, sequences of PCR fragments from three samples showed identities greater than 90% to two sequences of Chilli ringspot virus (ChiRSV), a member of Potyviridae, available in GenBank (Accession Nos. DQ925439 and DQ925438) (1), but less than 60% to that of the Hainan isolate of ChiVMV (Accession No. GQ981316), a distinct potyvirus (2). Furthermore, two of the samples contained one ChiRSV genotype while the third sample contained a different ChiRSV genotype, with a sequence identity of 91.7% between the two. Using these sequences, we subsequently designed a pair of primers (forward 5' TGGGATAGAGCATCTGAGC 3' and reverse 5' GAGTCATTTAGGTCATAATCAGTTT 3') for specific amplification of ChiRSV but not ChiVMV by RT-PCR. A ChiRSV-specific 0.6-kb DNA fragment was amplified from 8 of the 14 samples. Sequencing of these amplicons confirmed the presence of ChiRSV in these samples. Flexuous, rod-shaped virus particles, typical of the potyviruses, were observed by electron microscopy in the virion preparations purified from chili plants infected only with ChiRSV. Virion protein was purified and subjected to analysis by the MALDI-TOF/TOF tandem mass spectrometer (BGI, Shenzhen, China), yielding 35 peptide fragments that share the highest sequence homology to the coat protein of Vietnamese ChiRSV C8 and C9 isolates (GenBank Accession Nos. ABL09413 and ABL09414) (1) with protein sequence coverage of 61.8% and 52.9%, respectively. On the basis of these data, we concluded that the chili plants in Hainan were infected with ChiRSV. This virus was first reported in Vietnam in 2008 (1) but has not been found elsewhere. Leaves of the chili plants infected only with the Hainan isolate of ChiRSV displayed green banding along the main and major lateral veins, light interveinal chlorosis, and crinkling, similar to the symptoms of ChiVMV previously reported in Hainan (2). However, ChiVMV-infected leaves were notably more distorted than those infected by ChiRSV. We did not observe the characteristic ringspots described on ChiRSV-infected chili peppers in Vietnam (1). The difference in the symptoms may be accounted for by different ChiRSV genotypes, chili varieties, or a combination of both. The finding of two distinct viruses causing similar symptoms will help to improve identification and management of viral diseases on chili peppers. References: (1) C. Ha et al. Arch. Virol. 153:45, 2008. (2) J. Wang et al. Plant Dis. 90:377, 2006.

Red cell microparticle enumeration: validation of a flow cytometric approach

BACKGROUND AND OBJECTIVES

  There is growing interest in the clinical application of red blood cell (RBC) microparticle (MP) enumeration as they have been postulated to be effectors of coagulation and inflammation following transfusion and in sickle cell disease. No uniform approach in MP enumeration exists and a key limitation is the lack of an internal validation process. We present and validate a flow cytometric approach where an internal standard is utilized.

MATERIALS AND METHODS

  Glycophorin A(+) Annexin V(+) events were enumerated using MPs isolated from RBC units or plasma samples obtained from volunteers. A mixture of absolute counting (7·6 μm) and calibration beads (0·5, 0·9 and 3 μm) at a fixed ratio was added to each sample.

RESULTS

  RBC MPs were initially selected based upon a fluorescence threshold, and the 0·5- and 0·9-μm beads defined the upper and lower light scatter distribution of MPs. The ratio of 7·6:3-μm bead events was used as an internal standard to validate the precision of MP enumeration across samples (coefficient of variation = 2·5-7·2%) and remained constant in both platelet-rich plasma (PRP) and platelet-free plasma (PFP). RBC MP counts increased in both PRP and PFP obtained from whole blood stimulated with ionophore and increasing calcium concentrations, with PRP showing higher MP counts than PFP at every concentration studied.

CONCLUSION

  This method is a useful strategy to detect RBC MP counts across bio-samples provided that the flow cytometer can reliably discriminate the size of the calibration beads.

Advances in plant virus evolution: translating evolutionary insights into better disease management

Recent studies in plant virus evolution are revealing that genetic structure and behavior of virus and viroid populations can explain important pathogenic properties of these agents, such as host resistance breakdown, disease severity, and host shifting, among others. Genetic variation is essential for the survival of organisms. The exploration of how these subcellular parasites generate and maintain a certain frequency of mutations at the intra- and inter-host levels is revealing novel molecular virus-plant interactions. They emphasize the role of host environment in the dynamic genetic composition of virus populations. Functional genomics has identified host factors that are transcriptionally altered after virus infections. The analyses of these data by means of systems biology approaches are uncovering critical plant genes specifically targeted by viruses during host adaptation. Also, a next-generation resequencing approach of a whole virus genome is opening new avenues to study virus recombination and the relationships between intra-host virus composition and pathogenesis. Altogether, the analyzed data indicate that systematic disruption of some specific parameters of evolving virus populations could lead to more efficient ways of disease prevention, eradication, or tolerable virus-plant coexistence.

Introgression of B-genome chromosomes in a doubled haploid population of Brassica napus x B. carinata

The Brassica B-genome species possess many valuable agronomic and disease resistance traits. To transfer traits from the B genome of B. carinata into B. napus, an interspecific cross between B. napus and B. carinata was performed and a doubled haploid (DH) population was generated from the BC2S3 generation. Successful production of interspecific DH lines as identified using B-genome microsatellite markers is reported. Five percent of DH lines carry either intact B-genome chromosomes or chromosomes that have deletions. All of the DH lines have linkage group J13/B7 in common. This was further confirmed using B. nigra genomic DNA in a fluorescent in situ hybridization assay where the B-genome chromosomes were visualized and distinguished from the A- and C-genome chromosomes. The 60 DH lines were also evaluated for morphological traits in the field for two seasons and were tested for resistance to blackleg, caused by Leptosphaeria maculans, under greenhouse conditions. Variation in the DH population followed a normal distribution for several agronomic traits and response to blackleg. The lines with B-genome chromosomes were significantly different (p < 0.01) from the lines without B-genome chromosomes for both morphological and seed quality traits such as days to flowering, days to maturity, and erucic acid content.

Integration of genetic, physical, and cytogenetic maps for Brassica rapa chromosome A7

Bacterial artificial chromosome (BAC) contigs have been genetically mapped to the 10 linkage groups of Brassica rapa by BAC end sequences (BES). To integrate the genetic, physical, and cytogenetic maps, fluorescence in situ hybridization (FISH) was used to anchor the assembly of BAC contigs onto Brassica chromosomes using representative BACs. This BAC-FISH approach can be used to identify chromosome arms on separate mitotic metaphase chromosomes or to map multiple BACs to single long pachytene chromosomes. As part of an international consortium that is sequencing the B. rapa genome, we integrated the linkage and physical maps with the B. rapa cytogenetic map for chromosome A7 by hybridizing BACs to mitotic chromosomes and along the length of pachytene chromosome spreads. A total of 31 BACs that were putatively located on A7 were used as probes for FISH analyses; however, only 19 BACs mapped unambiguously to A7 while the remaining BACs either mapped to other chromosomes or hybridized to multiple locations. We then created a multicolor FISH cocktail of 16 BAC probes to simultaneously hybridize the entire length of the A7 chromosome. We successfully applied the 16 A7 BAC probe mix to B. rapa, B. oleracea, and domesticated and resynthesized genotypes of B. napus to demonstrate that this approach can facilitate studies of genome evolution by integrating the genetic, physical, and cytogenetic maps among closely related species of Brassica.

Catalpol attenuates MPTP induced neuronal degeneration of nigral-striatal dopaminergic pathway in mice through elevating glial cell derived neurotrophic factor in striatum

The protective effect of an iridoid catalpol extracted and purified from the traditional Chinese medicinal herb Rehmannia glutinosa on the neuronal degeneration of nigral-striatal dopaminergic pathway was studied in a chronic 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)/probenecid C57BL/6 mouse model and in 1-methyl-4-phenylpyridimium (MPP(+)) intoxicated cultured mesencephalic neurons. Rotarod performance revealed that the locomotor ability of mice was significantly impaired after completion of model production and maintained thereafter for at least 4 weeks. Catalpol orally administered for 8 weeks (starting from the second week of model production) dose dependently improved the locomotor ability. HPLC revealed that catalpol significantly elevated striatal dopamine levels without changing the metabolite/dopamine ratios. Nor did it bind to dopamine receptors. Therefore it is unlikely that catalpol resembles any of the known compounds for treating Parkinsonism. Instead, catalpol dose dependently raised the tyrosine hydroxylase (TH) neuron number in substantia nigra pars compacta (SNpc), the striatal dopamine transporter (DAT) density and the striatal glial cell derived neurotrophic factor (GDNF) protein level. Linear regression revealed that both the TH neuron number and DAT density were positively correlated to the GDNF level. In the cultured mesencephalic neurons, MPP(+) decreased the dopaminergic neuron number and shortened the neurite length, whereas catalpol showed protective effect dose dependently. Furthermore, the expression of GDNF mRNA was up-regulated by catalpol to a peak nearly double of normal control in neurons intoxicated with MPP(+) for 24 h but not in normal neurons. The GDNF receptor tyrosine kinase RET inhibitor 4-amino-5-(4-methyphenyl)-7-(t-butyl)-pyrazolo-[3,4-d]pyrimidine (PP1) abolished the protective effect of catalpol either partially (TH positive neuron number) or completely (neurite length). Taken together, catalpol improves locomotor ability by attenuating the neuronal degeneration of nigral-striatal dopaminergic pathway, and this attenuation is at least partially through elevating the striatal GDNF expression.

CD25high T cells with a prolonged survival inhibit development of diabetes

The goal of this study is to examine a novel hypothesis that the progression of diabetes is partially due to the weakened survival of CD25high T cells, and prolonging survival of CD25high T cells inhibits the development of diabetes. Since CD28 co-stimulation is essential for the survival of CD4+CD25high T cells, we determined whether CD28-upregulated translationally controlled tumor protein (TCTP) prolongs the survival of CD4+CD25high regulatory T cells (Tregs) by a transgenic approach. The TCTP transgene prevents Tregs from undergoing apoptosis induced by interleukin-2 withdrawal-, dexamethasone-, cyclophosphamide-, and anti-Fas treatment in vitro. In addition, transgenic Tregs express higher levels of FOXP3 than wild-type counterparts and maintain suppressive activity, suggesting that TCTP promotes Tregs escape from thymic negative selection, and that prolonged survival does not attenuate Treg suppression. Moreover, TCTP transgenic Tregs inhibit the development of autoimmune diabetes due to increased survival of suppressive Tregs and decreased expression of pancreatic TNF-alpha. Promoting the survival of CD25high T cells leads to prolonged survival of Tregs but not activated CD25+ non-Treg T cells. Thus, we propose a new model of "two phase survival" for Tregs. Our results suggest that modulation of Treg survival can be developed as a new therapy for autoimmune diseases.

TEMPEST simulations of collisionless damping of the geodesic-acoustic mode in edge-plasma pedestals

The fully nonlinear (full-f) four-dimensional TEMPEST gyrokinetic continuum code correctly produces the frequency and collisionless damping of geodesic-acoustic modes (GAMs) and zonal flow, with fully nonlinear Boltzmann electrons for the inverse aspect ratio scan and the tokamak safety factor q scan in homogeneous plasmas. TEMPEST simulations show that the GAMs exist in the edge pedestal for steep density and temperature gradients in the form of outgoing waves. The enhanced GAM damping may explain experimental beam emission spectroscopy measurements on the edge q scaling of the GAM amplitude.

Pyrazinoindolone inhibitors of MAPKAP-K2

Optimization of pyrazinoindolone inhibitors of MAPKAP-K2 (MK2) provides a reasonable balance of cellular potency and physicochemical properties. Mechanistic studies support the inhibition of MK2 which is responsible for the sub-micromolar cellular efficacy.

A novel unconventional antigen MPD5 elicits anti-tumor humoral immune responses in a subset of patients with polycythemia vera

In an effort to define the antigenic mechanism that contributes to beneficial therapeutic outcome in patients with polycythemia vera (PV), we screened a human testis cDNA library with serological cloning derived from sera of three PV patients who had undergone therapeutic-induced remission. As a result, we identified a novel antigen, MPD5, which belongs to the group of cryptic antigens with unconventional genomic intron/exon structure. Moreover, MPD5 elicited IgG antibody responses in a subset of PV patients who had benefited from a variety of therapies--including IFN-alpha, Hydroxyurea, Imatinib mesylate, Anagrelide, and phlebotomy--but not in untreated PV patients or healthy donors, suggesting that MPD5 is a PV-associated, therapy-related antigen. In the granulocytes of PV patients who are responsive to therapy, upregulated MPD5 expression may serve to enhance immune responses. These findings provide new insight into the mechanism underlying regulation of the self-antigen repertoire that elicits anti-tumor immune responses in patients with myeloproliferative diseases, indicating the potential of these self-antigens as targets of novel immunotherapy.

Endocrine outcome for children with embryonal brain tumors treated with craniospinal irradiation on the SJMB96 trial

9571

Background: To investigate the relationship between endocrine deficits with the radiation (RT) dose to the hypothalamic- pituitary axis (HPA) in medulloblastoma/PNET patients treated with risk-adapted craniospinal irradiation (CSI) followed by chemotherapy. Methods: 88 patients who survived at least 2 years from diagnosis were included in this analysis. CSI doses were 23.4 Gy or 36–39.6 Gy depending on clinical risk; the primary tumor site received 55.8 Gy. All pts had regular endocrine follow-up and screening to test for growth hormone (GH), thyroid hormone (TH) and adrenocorticotrophin hormone (ACTH) deficiency. Patients that had abnormal results on the screening tests underwent further evaluation by stimulation testing of the HPA. Only patients diagnosed with central hypothyroidism were included in the analysis for TH deficiency. Results: Of the 88 pts included in the study cohort, 77 pts had abnormal screening tests and underwent provocative testing. The median radiation dose to the hypothalamus was 42 Gy (26–57 Gy) and pituitary was 44 Gy (26–58 Gy). Patients receiving higher RT doses to the pituitary had a significantly higher incidence of growth hormone deficiency with 4-year estimates of 100 ±3% for those receiving = 44Gy and 82±7% for those receiving < 44 Gy (p=0.024). Four-year estimates of thyroid hormone deficiency for patients receiving = 44 Gy to the pituitary were 67±21% and 18±14% for those receiving < 44 Gy (p<0.010). There was no correlation between the dose to the pituitary with the incidence of ACTH deficiency. The estimated change in height z-score for patients receiving < 44 Gy to the pituitary was - 0.53 units per year (-0.44 to -0.63) compared with -0.70 units per year (-0.62 to -0.78) for those receiving = 44 Gy. Conclusions: Data from this prospective study demonstrate that RT to the HPA is the key determinant for developing endocrinopathies in patients with medulloblastoma/PNET.

No significant financial relationships to disclose.