First Report of a Group 16SrI Phytoplasma Associated with Amaranthus hypochondriacus Cladodes in China

Amaranthus spp. are cultivated worldwide as leafy vegetable, cereal, and ornamentals. In China, stems and leaves of Amaranthus hypochondriacus L. are used as a vegetable (2). In July 2010, sporadic amaranth plants exhibiting symptoms of cladodes and spica proliferation were observed in a vegetable garden near Foshan, Guangdong, China. Stem samples were collected from two symptomatic and two asymptomatic plants. Total DNA was extracted with a modified cetyltrimethylammonium bromide (CTAB) method (1). Nested PCR with a combination of phytoplasma-specific universal primer pairs (P1/P7 and R16F2n/R16R2) amplified 16S rDNA sequences with the expected size of 1.2 kb from all samples of symptomatic amaranth plants, but not from the asymptomatic plants (3). Nested PCR products yielded identical AluI, HhaI, HpaII, HaeIII, KpnI, MseI, RsaI, Sau3AI, and TaqI restriction fragment length polymorphism (RFLP) profiles with chinaberry witches'-broom phytoplasma (16SrI-B subgroup), but different from peanut witches'-broom phytoplasma (16SrII group), jujube witches'-broom phytoplasma (16SrV group), and paulownia witches'-broom phytoplasma (16SrI-D subgroup). Nested PCR products were purified, cloned in pMD18-T Simple Vector (TaKaRa, Dalian, China), and sequenced. The 16S rDNA sequences were identical and deposited in GenBank (Accession No. JF323034). GenBank BLASTn analysis indicated that the amaranth extracts showed as high as 99% sequence identity with the members of 16SrI group phytoplasmas, including those associated with arecanut yellow leaf disease (FJ998269) and aster yellow AY-27 (HM467127). A polygenetic tree was constructed using MEGA 4.0 based on the 16S rDNA sequences of amaranth cladode phytoplasma and other phytoplasmas belonging to 16SrI phytoplasma group. In phylogenetic analysis, the sequences clustered on a single branch with members of 16SrI-B subgroup in the tree. Therefore, the phytoplasma was classified in subgroup 16SrI-B. To our knowledge, this is the first report of a subgroup 16SrI-B phytoplasma associated with diseased A. hypochondriacus in China. References: (1) E. Angelini et al. Vitis 40:79, 2001. (2) M. Costea et al. Econ. Bot. 57:646, 2003. (3) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.

Analysis of the optimal cut-point for HIV-p24 antigen testing to diagnose HIV infection in HIV-exposed children from resource-constrained settings

BACKGROUND

Nucleic-acid-testing (NAT) to diagnose HIV infection in children under age 18 months provides a barrier to HIV-testing in exposed children from resource-constrained settings. The ultrasensitive HIV-p24-antigen (Up24) assay is cheaper and easier to perform and is sensitive (84-98%) and specific (98-100%). The cut-point optical density (OD) selected for discriminating between positive and negative samples may need assessment due to regional differences in mother-to-child HIV-transmission rates.

OBJECTIVES

We used receiver operator characteristics (ROC) curves and logistic regression analyses to assess the effect of various cut-points on the diagnostic performance of Up24 for HIV-infection status among HIV-exposed children. Positive and negative predictive values at different rates of disease prevalence were also estimated.

STUDY DESIGN

A study of Up24 testing on dried blood spot (DBS) samples collected from 278 HIV-exposed Haitian children, 3-24-months of age, in whom HIV-infection status was determined by NAT on the same DBS card.

RESULTS

The sensitivity and specificity of Up24 varied by the cut-point-OD value selected. At a cut-point-OD of 8-fold the standard deviation of the negative control (NCSD), sensitivity and specificity of Up24 were maximized [87.8% (95% CI, 83.9-91.6) and 92% (95% CI, 88.8-95.2), respectively]. In lower prevalence settings (5%), positive and negative predictive values of Up24 were maximal (75.9% and 98.8%, respectively) at a cut-point-OD that was 15-fold the NCSD.

CONCLUSIONS

In low prevalence settings, a high degree of specificity can be achieved with Up24 testing of HIV-exposed children when a higher cut-point OD is used; a feature that may facilitate more frequent use of Up24 antigen testing for HIV-exposed children.

Electro-optic guided-to-radiation mode conversion in annealed proton-exchanged PPLN waveguides

We report the design and experimental demonstration of electro-optically active TM-guided to TE-radiation mode converters in annealed proton-exchanged (APE) periodically poled lithium niobate (PPLN) channel waveguides in telecom S-C-L bands (1495-1640 nm). A maximum mode conversion efficiency of >95%/cm was obtained at 1520 nm from a 24-μm-period APE PPLN waveguide under an electro-optic (EO) field of ~6.3 V/μm at 35°C. This efficiency has been enhanced by a factor of >4.6 over a waveguide built in the single-domain (unpoled) LiNbO3; it is also to the best of our knowledge the most efficient guided-to-radiation (GTR) mode converter ever reported based on LiNbO3 on-axis waveguides. A conversion bandwidth of ~250 nm was also observed from this EO GTR mode converter.

Salvage radiotherapy in patients with recurrent or refractory primary or secondary central nervous system lymphoma after methotrexate-based chemotherapy

BACKGROUND

To assess the efficacy of salvage radiation therapy (RT) in patients with recurrent/refractory primary or secondary central nervous system lymphoma (CNSL) after initial methotrexate (MTX)-based chemotherapy and to identify factors associated with treatment outcome.

PATIENTS AND METHODS

We reviewed 36 patients with primary or secondary CNSL who relapsed after MTX therapy and received salvage RT. Primary end points were radiographic response and overall survival (OS).

RESULTS

After salvage RT, 18 patients (50%) achieved a complete radiographic response and 6 (17%) achieved a partial response, for an overall response rate of 67% [95% confidence interval (CI) 49% to 81%]. The median OS from start of salvage RT was 11.7 months (range: 0.6-94.7). Patients treated with less than five cycles of MTX before failure had a significantly shorter OS than patients who received five or more cycles (9.2 months versus not reached, P = 0.04). Patients with CNSL limited to brain only had a significantly longer OS than patients with disease in the brain and other central nervous system locations (16.5 versus 4.5 months, P=0.01).

CONCLUSION

Salvage RT is effective for patients with recurrent/refractory primary or secondary CNSL after initial MTX therapy. Having received five or more cycles of MTX before failure and CNSL limited to the brain at relapse are associated with longer OS.

Quantitative trait loci mapping of leaf angle and leaf orientation value in maize (Zea mays L.)

A major limiting factor for high productivity of maize (Zea mays L.) in dense planting is light penetration through the canopy. Plant architecture with a narrower leaf angle (LA) and an optimum leaf orientation value (LOV) is desirable to increase light capture for photosynthesis and production per unit area. However, the genetic control of the plant architecture traits remains poorly understood in maize. In this study, QTL for LA, LOV, and related traits were mapped using a set of 229 F(2:3) families derived from the cross between compact and expanded inbred lines, evaluated in three environments. Twenty-five QTL were detected in total. Three of the QTL explained 37.4% and five of the QTL explained 53.9% of the phenotypic variance for LA and LOV, respectively. Two key genome regions controlling leaf angle and leaf orientation were identified. qLA1 and qLOV1 at nearest marker umc2226 on chromosome 1.02 accounted for 20.4 and 23.2% of the phenotypic variance, respectively; qLA5 and qLOV5 at nearest bnlg1287 on chromosome 5 accounted for 9.7 and 9.8% of the phenotypic variance, respectively. These QTL could provide useful information for marker-assisted selection in improving performance of plant architecture with regard to leaf angle and orientation.

Low-dose MTX combined with low-dose methylprednisolone as a first-line therapy for the treatment of acute GVHD: safety and feasibility

To study the efficacy and safety of a low dose of MTX combined with a low dose of methylprednisolone (MP) as a first-line therapy in the treatment of acute GVHD (aGVHD) after allogeneic hematopoietic SCT, 32 patients received i.v. MTX at a dose of 10 mg or oral MTX at a dose of 15 mg every 3-7 days (repeated at day 3 after the first dose and then at a weekly interval) combined with a low dose of MP (0.5 mg/kg/day) until a complete or partial response was achieved, or until treatment failure or intolerable side effects occurred. The overall treatment response rate was 81% (26/32 patients) and the response rate at day 28 was 75% (24/32 patients). The response rate for GVHD involving various organs was 88% (23/26) in the skin, 75% (3/4) in the liver and 81% (9/11) in the gut. Grade 3 toxicities occurred in only three patients presenting cytopenias. The estimated survival at 2 years was 77%. From this analysis, MTX in combination with a low dose of MP appears to be a well-tolerated, effective and inexpensive regime when used as a first-line treatment for aGVHD.

Pulsed orange generation optimized in a diode-pumped Nd:YVO4 laser using monolithic dual PPLN electro-optic Q switches

We report a pulsed intracavity sum-frequency generator in a diode-pumped, dual-wavelength Nd:YVO(4) laser whose operation was optimized with two electro-optic Q switches built in a monolithic periodically poled lithium niobate (PPLN) crystal. The dual PPLN Q switches, though integrated, are able to work separately at their respective working wavelengths of 1064 and 1342 nm. At 4.8 W diode pump power and 5 kHz Q-switching rate, a maximum orange (593 nm) output peak power of >480 W was achieved in this laser system using the Q-switch opening-time offset technique. This power is approximately 1.7 times higher than that obtained with the system operated in a conventional single-Q-switch mode.

Heat shock protein 72 is associated with the hepatitis C virus replicase complex and enhances viral RNA replication

The NS5A protein of the hepatitis C virus (HCV) is an integral component of the viral replicase. It also modulates cellular signaling and perturbs host interferon responses. The multifunctional characteristics of NS5A are mostly attributed to its ability to interact with various cellular proteins. This study aimed to identify the novel cellular factors that interact with NS5A and decipher the significance of this interaction in viral replication. The NS5A-interacting proteins were purified by the tandem affinity purification (TAP) procedure from cells expressing NS5A and identified by mass spectrometry. The chaperone protein Hsp72 was identified herein. In vivo protein-protein interaction was verified by co-immunoprecipitation and an in situ proximity ligation assay. In addition to NS5A, Hsp72 was also associated with other members of the replicase complex, NS3 and NS5B, suggesting that it might be directly involved in the HCV replication complex. Hsp72 plays a positive regulatory role in HCV RNA replication by increasing levels of the replicase complex, which was attributed either to the increased stability of the viral proteins in the replicase complex or to the enhanced translational activity of the internal ribosome entry site of HCV. The fact that the host chaperone protein Hsp72 is involved in HCV RNA replication may represent a therapeutic target for controlling virus production.

Tuning the exciton binding energies in single self-assembled InGaAs/GaAs quantum dots by piezoelectric-induced biaxial stress

We study the effect of an external biaxial stress on the light emission of single InGaAs/GaAs(001) quantum dots placed onto piezoelectric actuators. With increasing compression, the emission blueshifts and the binding energies of the positive trion (X+) and biexciton (XX) relative to the neutral exciton (X) show a monotonic increase. This phenomenon is mainly ascribed to changes in electron and hole localization and it provides a robust method to achieve color coincidence in the emission of X and XX, which is a prerequisite for the possible generation of entangled photon pairs via the recently proposed "time reordering" scheme.

Balloon kyphoplasty versus vertebroplasty for treatment of osteoporotic vertebral compression fracture: a prospective, comparative, and randomized clinical study

Bone pain and spinal axial deformity are major concerns in aged patients suffering from osteoporotic vertebral compression fracture (VCF). Pain can be relieved by vertebroplasty or kyphoplasty procedures, in which the compressed vertebral body is filled with substitutes. We randomly assigned 100 patients with osteoporotic compression fracture at the thoraco-lumbar (T-L) junction into two groups: vertebroplasty and kyphoplasty; we used polymethylmethacrylate (PMMA) as the bone filler. Pain before and after treatment was assessed with visual analog scale (VAS) scores and vertebral body height and kyphotic wedge angle were measured from reconstructed computed tomography images. More PMMA was used in the kyphoplasty group than in the vertebroplasty group (5.56 +/- 0.62 vs. 4.91 +/- 0.65 mL, p < 0.001). Vertebral body height and kyphotic wedge angle of the T-L spine were also improved (p < 0.001). VAS pain scores did not differ significantly between the treatment groups. The duration of follow-up was 6 months. Two patients in the kyphoplasty group had an adjacent segment fracture. In terms of clinical outcome there was little difference between the treatment groups. Thus, owing to the higher cost of the kyphotic balloon procedure, we recommend vertebroplasty over kyphoplasty for the treatment of osteoporotic VCFs.

INTRODUCTION

Spinal axial deformities are major concerns in aged patients suffering from osteoporotic vertebral compression fracture. Pain may be relieved by vertebroplasty or kyphoplasty. We investigated the radiological and clinical outcomes of these procedures.

METHODS

One hundred cases of VCF at the thoraco-lumbar junction were randomly assigned into two groups: vertebroplasty or kyphoplasty (50 cases each). We used polymethylmethacrylate as the bone filler. Pain before and after treatment was assessed with visual analog scale scores and vertebral body height and kyphotic wedge angle were measured from reconstructed computed tomography images.

RESULTS

More PMMA was used in the kyphoplasty group than in the vertebroplasty group (5.56 +/- 0.62 vs. 4.91 +/- 0.65 mL, p < 0.001). Vertebral body height and kyphotic wedge angle of the T-L spine were also improved (p < 0.001). VAS pain scores did not differ significantly between the treatment groups. The duration of follow-up was 6 months. Two patients in the kyphoplasty group had an adjacent segment fracture.

CONCLUSIONS

In terms of clinical outcome there was little difference between the treatment groups. Thus, with the higher cost of the kyphotic balloon procedure, we recommend vertebroplasty over kyphoplasty for the treatment of osteoporotic VCFs.

Estimating allergenicity of latex gloves using Hev b 1 and hevamine

BACKGROUND

Latex allergy continues to be an increasingly serious occupational health problem in Taiwan, where it affects approximately 6.8% to 12% of health care workers. Contrasting with reports from western countries, Hev b 1 and hevamine, and not Hev b 3, 5 or 6.02, are the major latex allergens among health care workers in Taiwan. This study aimed at evaluating the allergenicity of 30 brands of commercially available medical latex gloves in Taiwan in 2007.

METHODS

Residual Hev b 1 and hevamine from the gloves were measured by inhibition enzyme-linked immunosorbent assay using polyclonal antibodies against purified recombinant Hev b 1 and hevamine. The results were compared to those achieved with quantification of residual total extractable proteins and skin prick testing.

RESULTS

The residual extractable protein levels in 30 medical gloves all conformed to United States Food and Drug Administration regulations. All the gloves except one yielded strong skin prick reactions in latex-allergic individuals. The only brand of gloves that consistently produced no skin prick reactions in latex-allergic individuals contained the lowest residual levels of Hev b 1 (0.60 microg/g) and hevamine (0.07 microg/g).

CONCLUSIONS

Our results suggest that the measurement of residual extractable total proteins is not sufficient to assess the allergenicity of latex gloves and that Hev b 1 and hevamine may be used as indicator allergens in areas where they are major latex allergens, such as Taiwan.

Down-regulation of mitochondrial ATPase by hypermethylation mechanism in chronic myeloid leukemia is associated with multidrug resistance

BACKGROUND

To identify novel proteins involved in multidrug resistance in chronic myeloid leukemia (CML).

MATERIALS AND METHODS

Comparative proteomics was used to screen multidrug resistance-related proteins from K562 and K562/A02; the differently expressed proteins were further confirmed by western blot and real-time PCR. short hairpin RNA (shRNA) assay was applied to determine the relationship between candidate protein and adriamycin resistance. Bisulfite sequencing was carried out to assess methylation status of candidate multidrug resistance-related gene promoter. K562/A02 was treated with 5-azacytidine or trichostatin A (TSA); multidrug resistance phenotype and corresponding protein or gene changes were detected.

RESULTS

Seventeen proteins with altered abundances of more than twofold were detected, among which mitochondrial ATPase in K562/A02 was significantly down-regulated. Suppressing mitochondrial ATPase by shRNA could enhance adriamycin resistance and antiapoptosis activity of K562. The promoter hypermethylation in mitochondrial ATPase was found to be attributed to the adriamycin-resistant phenotype of both K562/A02 (methylated frequency 18.18%) and CML primary cells in accelerated phase (methylated frequency 7.95%) or blast crisis (methylated frequency 26.59%). Inhibition of hypermethylation increased adriamycin sensitivity of K562/A02. A synergistic effect on reversing adriamycin-resistant phenotype was obtained when 5-azacytidine was combined with TSA.

CONCLUSION

Down-regulation of mitochondrial ATPase can lead to adriamycin resistance in CML and the mechanism is associated with DNA methylation regulation.

Narrow-line, cw orange light generation in a diode-pumped Nd:YVO4 laser using volume Bragg gratings

We report on the demonstration of a narrow-line, cw orange 593-nm laser achieved via intracavity sum-frequency generation (SFG) of a diode-pumped dual-wavelength (1064 and 1342 nm) Nd:YVO(4) laser using two volume Bragg grating (VBG) reflectors. At diode pump power of up to 3.6 W, the 593-nm intracavity SFG laser radiates at the single longitudinal mode of spectral linewidth as narrow as approximately 15 MHz. More than 23-mW single-longitudinal-mode or 40-mW, <8.5-GHz (10-pm) linewidth (at 4.2-W diode pump power) 593-nm orange lights can be obtained from this compact laser system. Spectral tuning of the orange light was performed via the temperature tuning of the two VBGs in this system, achieving an effective tuning rate of ~5 pm/degrees C.

Antigens containing TAVSPTTLR tandem repeats could be used in assaying antibodies to Classical swine fever virus

Classical swine fever virus (CSFV) causes a highly contagious and often fatal viral disease in pigs. The highly conserved epitope TAVSPTTLR on the glycoprotein E2 was shown to be suitable for differentiation of CSFV from other pestiviruses. In this study, we found that swine CSFV antisera contained TAVSPTTLR-related rather than TAVSPTTLR-specific CSFV antibodies. The CSFV antisera reacted only to some extent with a synthetic TAVSPTTLR-containing peptide, but inhibited the binding of TAVSPTTLR-specific antibodies to the viral antigen. Since chimeric antigens containing TAVSPTTLR tetramers or hexamers were recognized by the swine CSFV antisera, such antigens could be potentially applied to the detection of CSFV antibodies. These results might be helpful in designing a TAVSPTTLR epitope-based CSFV vaccine and a corresponding serological test.

Anomalous-circular photogalvanic effect in a GaAs/AlGaAs two-dimensional electron gas

We have studied the circular photogalvanic effect (CPGE) in a GaAs/AlGaAs two-dimensional electron gas excited by near infrared light at room temperature. The anomalous CPGE observed under normal incidence indicates a swirling current which is realized by a radial spin current via the reciprocal spin-Hall effect. The anomalous CPGE exhibits a cubic cosine dependence on the incidence angle, which is discussed in line with the above interpretation.

Cadmium and other metal uptake by Lobelia chinensis and Solanum nigrum from contaminated soils

Cadmium concentrations in two plant species and their corresponding soils were evaluated in a metal contaminated area. The average Cd concentrations reached 36.9 and 141 mg kg(-1) in Solanum nigrum leaves and Lobelia chinensis shoots, respectively. There is a significant relationship between the Cd concentration in the aerial tissues and the corresponding soils on a logarithmic scale. Under the hydroponic culture conditions, the maximum Cd concentration in the S. nigrum leaves and L. chinensis shoots were 1,110 and 414 mg kg(-1), respectively. Cd concentration was higher in the roots than in the aerial parts. The two plants may be used in suitable phytoremediation process.

Single aperiodically poled lithium niobate for simultaneous laser Q switching and second-harmonic generation in a 1342 nm Nd:YVO4 laser

We report the design and experimental demonstration of an electro-optically Q-switched intracavity second-harmonic generator (ISHG) based on a single aperiodically poled lithium niobate (APLN) in a 1,342 nm Nd:YVO(4) laser. This intracavity APLN, designed using the aperiodic optical superlattice technique, can perform simultaneously as a laser Q switch and a second-harmonic generator. At approximately 200 VQ-switching voltage and a 5 kHz switching rate, we measured a pulse energy of approximately 5.7 microJ and a peak power of approximately 700 W at 671 nm from the constructed ISHG with a 5.2 W diode power based on 51% fundamental energy depletion.

Risk factors for extra-pulmonary tuberculosis compared to pulmonary tuberculosis

BACKGROUND

Tuberculosis (TB) continues to be a major global health problem. Extra-pulmonary TB (EPTB) manifests with protean symptoms, and establishing a diagnosis is more difficult than pulmonary TB (PTB).

SETTING

A university-affiliated hospital in southern Taiwan.

OBJECTIVE

To analyse the risk factors for EPTB compared with PTB.

DESIGN

This retrospective study compared patients with EPTB and PTB in southern Taiwan by analysing their demographic data and clinical underlying diseases. Risk factors for EPTB were further analysed.

RESULTS

A total of 766 TB patients were enrolled in this study, with 102 (13.3%) EPTB and 664 (86.7%) PTB cases. Of the 766 patients, 3% of PTB patients had EPTB, while 19.6% of EPTB patients also had PTB. The most frequently involved EPTB site was the bone and joints (24.5%). The incidence of EPTB vs. PTB decreased significantly for each decade increase in patient age. Multivariate logistic regression analysis showed that being female, not being diabetic, having end-stage renal disease and not smoking were independent risk factors for EPTB.

CONCLUSION

This study defines the risk factors for EPTB compared with PTB. Awareness of these factors is essential for physicians to have a high index of suspicion for accurate and timely diagnosis.

Unique histological features of the left atrial posterior wall

The left atrial posterior wall (LAPW) plays a critical role in atrial fibrillation, but the underlying mechanism remains unclear. In the present study, we sought to characterize the histological features of the LAPW. Different atrial regions were dissected from hearts of normal Sprague-Dawley rats and humans. Haematoxylin/eosin and van Gieson staining were used to analyse atrial cardiomyocyte arrangement and collagen distribution, respectively. Intercellular junctions were evaluated by transmission electron microscopy. In contrast with other atrial regions, the LAPW exhibited more disorganized cardiomyocytes, larger intercellular spaces and variable myocardial fibre arrangement. The proportion of collagen was significantly higher in the LAPW than in other atrial regions. Interestingly, desmosomes were sparse along with intercellular gaps in the LAPW. In summary, distinct disarrangement of cardiomyocytes and an abundance of collagen exist in the LAPW. The sparsity of desmosomes in the LAPW may be related to the heterogeneous distribution and separation of atrial myocytes.

Does multiple sclerosis increase risk of adverse pregnancy outcomes? A population-based study

Objective

To determine whether maternal multiple sclerosis (MS) is associated with increased risk of adverse pregnancy outcomes in an East Asian country by using a nationwide population-based dataset.

Method

This study linked two nationwide population-based datasets, the birth certificate registry and the Taiwan National Health Insurance Research Dataset. We identified a total of 174 women who gave birth from 2001 to 2003, who were diagnosed with MS within the 2 years preceding the index deliveries, together with 1,392 matched women without chronic disease as a comparison cohort. Multivariate logistic regression analyses were performed for estimation.

Results

We found that compared with healthy mothers, MS was independently associated with a 2.25-fold risk of preterm birth (95% CI = 1.37–3.70) and a 1.89-fold (95% CI = 1.30–2.76) higher risk of babies small for gestational age, after adjusting for family income and maternal, paternal, and infant characteristics. Mothers with MS were also more likely to have cesarean deliveries.

Conclusion

Our study documents increased the risk of adverse pregnancy outcomes for mothers with MS, highlighting a need for more intensive monitoring and obstetric care during pregnancy. Future studies should explore the distinct manifestations and mechanisms of MS in diverse ethnic groups, so more complete information can be provided to affected women concerning pregnancy.