Interactions between epinephrine, ascending vagal fibers, and central noradrenergic systems in modulating memory for emotionally arousing events

It is well-established that exposure to emotionally laden events initiates secretion of the arousal-related hormone epinephrine in the periphery. These neuroendocrine changes and the subsequent increase in peripheral physiological output play an integral role in modulating brain systems involved in memory formation. The impermeability of the blood brain barrier to epinephrine represents an important obstacle in understanding how peripheral hormones initiate neurochemical changes in the brain that lead to effective memory formation. This obstacle necessitated the identity of a putative pathway capable of conveying physiological changes produced by epinephrine to limbic structures that incorporate arousal and affect related information into memory. A major theme of the proposed studies is that ascending fibers of the vagus nerve may represent such a mechanism. This hypothesis was tested by evaluating the contribution of ascending vagal fibers in modulating memory for responses learned under behavioral conditions that produce emotional arousal by manipulating appetitive stimuli. A combination of electrophysiological recording of vagal afferent fibers and in vivo microdialysis was employed in a second study to simultaneously assess how elevations in peripheral levels of epinephrine affect vagal nerve discharge and the subsequent potentiation of norepinephrine release in the basolateral amygdala. The final study used double immunohistochemistry labeling of c-fos and dopamine beta hydroxylase (DBH), the enzyme for norepinephrine synthesis to determine if epinephrine administration alone or stimulation of the vagus nerve at an intensity identical to that which improved memory in Experiment 1 produces similar patterns of neuronal activity in brain areas involved in processing memory for emotional events. Findings emerging from this collection of studies establish the importance of ascending fibers of the vagus nerve as an essential pathway for conveying the peripheral consequences of physiological arousal on brain systems that encode new information into memory storage.

Chromate reduction on humic acid derived from a peat soil--exploration of the activated sites on HAs for chromate removal

Humic substances are a major component of soil organic matter that influence the behavior and fate of heavy metals such as Cr(VI), a toxic and carcinogenic element. In the study, a repetitive extraction technique was used to fractionate humic acids (HAs) from a peat soil into three fractions (denoted as F1, F2, and F3), and the relative importance of O-containing aromatic and aliphatic domains in humic substances for scavenging Cr(VI) was addressed at pH 1. Spectroscopic analyses indicated that the concentrations of aromatic C and O-containing functional groups decreased with a progressive extraction as follows: F1>F2>F3. Cr(VI) removal by HA proceeded slowly, but it was enhanced when light was applied due to the production of efficient reductants, such as superoxide radical and H(2)O(2), for Cr(VI). Higher aromatic- and O-containing F1 fraction exhibited a greater efficiency for Cr(VI) reduction (with a removal rate of ca. 2.89 mmol g(-1) HA under illumination for 3 h). (13)C NMR and FTIR spectra further demonstrated that the carboxyl groups were primarily responsible for Cr(VI) reduction. This study implied the mobility and fate of Cr(VI) would be greatly inhibited in the environments containing such organic groups.

The preparation and characterization of gold-conjugated polyphenol nanoparticles as a novel delivery system

Nanogold particles are commonly used in nanomedicine. We generated physical nanogold (pNG) conjugated with different ratios of epigallocatechin-3-gallate (EGCG) and evaluated its physicochemical properties, antioxidant activity, and cytotoxicity in vitro as well as anticancer activity in vivo. Results showed that the EGCG-pNG conjugates were successfully prepared at ratios between 23:1 and 23:5, with the percentage of EGCG content increasing with the EGCG:pNG ratio from 23:1 (2.0% ± 0.02%) to 23:5 (28% ± 0.3%). EGCG-pNG particles at ratios of 23:1 and 23:5 demonstrated significantly decreased size from 500 to 20 nm and decreasing zeta potentials of 21 mV to −22 mV, respectively. At a ratio of 23:2.5, the EGCG-pNG particles (27% EGCG, 50 nm in size, zeta potential of −8 mV) showed longer EGCG activity half-life (110 days vs 5 hours), controlled release (2 hours vs 30 minutes), and higher antioxidant activity (four times), as well as inhibition of tumor cell growth, than controls. The present study indicated that EGCG-pNG possesses promising therapeutic potential, based on its strong free-radical scavenging and anticancer activities.

Inosine, not adenosine, initiates endothelial glycocalyx degradation in cardiac ischemia and hypoxia

Ischemia/reperfusion and hypoxia/reoxygenation of the heart both induce shedding of the coronary endothelial glycocalyx. The processes leading from an oxygen deficit to shedding are unknown. An involvement of resident perivascular cardiac mast cells has been proposed. We hypothesized that either adenosine or inosine or both, generated by nucleotide catabolism, attain the concentrations in the interstitial space sufficient to stimulate A3 receptors of mast cells during both myocardial ischemia/reperfusion and hypoxia/reoxygenation. Isolated hearts of guinea pigs were subjected to either normoxic perfusion (hemoglobin-free Krebs-Henseleit buffer equilibrated with 95% oxygen), 20 minutes hypoxic perfusion (buffer equilibrated with 21% oxygen) followed by 20 minutes reoxygenation, or 20 minutes stopped-flow ischemia followed by 20 minutes normoxic reperfusion (n = 7 each). Coronary venous effluent was collected separately from so-called transudate, a mixture of interstitial fluid and lymphatic fluid appearing on the epicardial surface. Adenosine and inosine were determined in both fluid compartments using high-performance liquid chromatography. Damage to the glycocalyx was evident after ischemia/reperfusion and hypoxia/reoxygenation. Adenosine concentrations rose to a level of 1 μM in coronary effluent during hypoxic perfusion, but remained one order of magnitude lower in the interstitial fluid. There was only a small rise in the level during postischemic perfusion. In contrast, inosine peaked at over 10 μM in interstitial fluid during hypoxia and also during reperfusion, while effluent levels remained relatively unchanged at lower levels. We conclude that only inosine attains levels in the interstitial fluid of hypoxic and postischemic hearts that are sufficient to explain the activation of mast cells via stimulation of A3-type receptors.

Chromate removal as influenced by the structural changes of soil components upon carbonization at different temperatures

Surface fire could induce heat transferring into the soil, creating a carbonized environment, which may alter the chemical compositions of soil organic matters (SOM). In the study, a surface soil was carbonized at up to 600 °C with limited air to simulate soils experiencing a surface fire, and Cr(VI) removal on the carbonized soils was investigated. NMR and FTIR analyses demonstrated a remarkable change of SOM structures at 300-400 °C. TGA-MS spectra indicated that (e.g. C(2)H(4), CH(3)OH and C(3)H(8)) were the major components in the evolved gases from the pyrolyzed soil. A maximum amount of Cr(VI) removal (ca. 4 mg g(-1) soil) occurred for the 200 °C-carbonized soils, attributed mainly to a significant increase of Cr(VI) reduction by 0.1 M KCl extractable organic carbon (EOC) with abundant carboxylic groups. Nonetheless, the formation of aromatic C upon carbonization of the soil at >400 °C may be responsible for Cr(VI) reduction.

Influence of chemical compositions and molecular weights of humic acids on Cr(VI) photo-reduction

Humic acids (HA) strongly affect the fate of trace metals in soils and aquatic environments. One of the remarkable properties of HA is its ability to reduce Cr(VI), an extremely toxic anion. However, it is unclear which HA components are involved in Cr(VI) reduction and possess the photo-induced properties. In this study, an ultrafiltration technique was used to fractionate HAs into four fractions of different nominal molecular weights (M(w)): >100, 50-100, 10-50 and <10 kDa. Each HA fraction was characterized by spectroscopic analyses followed by examining Cr(VI) removal on each fraction of HA at pH 1-5. Spectroscopic results indicated that low-M(w) HA was enriched with polar and aromatic domains. These polar, including polar C in aliphatic region, and aromatic groups were the major sites for Cr(VI) reduction because they disappeared rapidly upon interaction with Cr(VI). As a result, low M(w) of HA exhibited greater efficiency of Cr(VI) reduction. Light induced the rapid transfer of electrons between chromate-phenol/carboxyl ester, or the formation of peroxide radicals or H(2)O(2) through the ready decay of peroxy radicals associated with polar substituents, explained the rapid scavenging of Cr(VI) on polar and aromatic groups of HAs under illumination.

The association between Internet addiction and psychiatric disorder: a review of the literature

Internet addiction is a newly emergent disorder. It has been found to be associated with a variety of psychiatric disorders. Information about such coexisting psychiatric disorders is essential to understand the mechanism of Internet addiction. In this review, we have recruited articles mentioning coexisting psychiatric disorders of Internet addiction from the PubMed database as at November 3, 2009. We describe the updated results for such disorders of Internet addiction, which include substance use disorder, attention-deficit hyperactivity disorder, depression, hostility, and social anxiety disorder. We also provide discussion for possible mechanisms accounting for the coexistence of psychiatric disorders and Internet addiction. The review might suggest that combined psychiatric disorders mentioned above should be evaluated and treated to prevent their deteriorating effect on the prognosis of Internet addiction. On the other hand, Internet addiction should be paid more attention to when treating people with these coexisting psychiatric disorders of Internet addiction. Additionally, we also suggest future necessary research directions that could provide further important information for the understanding of this issue.

Localized joule heating as a mask-free technique for the local synthesis of ZnO nanowires on silicon nanodevices

We report a mask-free technique for the local synthesis of ZnO nanowires (NWs) on polysilicon nanobelts and polysilicon NW devices. First, we used localized joule heating to generate a poly(methyl methacrylate) (PMMA) nanotemplate, allowing the rapid and self-aligned ablation of PMMA within a short period of time (ca. 5 μs). Next, we used ion-beam sputtering to prepare an ultrathin Au film and a ZnO seed layer; a subsequent lift-off process left the seed layers selectively within the PMMA nanotemplate. Gold nanoparticles and ZnO NWs were formed selectively in the localized joule heating region.

Differential gene expression between the porcine morula and blastocyst

The survival and development of pre-implantation embryos are determinant factors affecting the outcome of animal reproduction. It is essential to transfer the expression of the genetic material from maternal sources, that is the ovum to the zygote before implantation to ensure successful development. Differentiation and transformation of blastomeres initiated during the morula and blastocyst stages is an important step of the embryonic development prior to implantation. We collected morula and early blastocyst samples from pure-bred Landrace pigs in vivo to study the differential gene expression patterns at these two stages. Total RNA was extracted from individual embryos and two rounds of amplification were employed. Two micrograms of antisense RNA, targets, were prepared and hybridized with each of four custom made oligo microarrays representing 24,000 porcine genes. The analyses of replicate hybridizations showed that among the 24,000 genes, 162 genes were expressed fivefold or greater in the morula compared to early blastocysts and 2126 genes were expressed fivefold or greater in early blastocysts compared to the morula. Of these differentially expressed genes, 1429 genes were functionally annotated with related human Gene Ontology terms. In addition to basic metabolic processes, genes related to signal transduction, transportation and cell differentiation were found in both stages and were up-regulated as embryo development proceeded. Real time polymerase chain reaction was utilized to quantify 12 genes differentially expressed in the 2 embryonic stages and validated the reliability of major evidences shown in microarrays. In conclusion, we have obtained a preliminary landscape of genes differentially expressed during the transition from morula to early blastocysts in pigs and showed a generally increased transcriptional activity, perhaps in preparation for implantation. Our results provide an opportunity to study the functions of these genes in relation to the development and survival of pre-implantation porcine embryos.

Avian pox infection in a free-living crested serpent eagle (Spilornis cheela) in southern Taiwan

Avian pox viruses (APVs) have been reported to cause infection in diverse avian species worldwide. Herein we report the first case of APV infection in a free-living bird, a subadult crested serpent eagle (Spilornis cheela), in Taiwan. In addition to the typical wart-like lesions distributed on the cere, eyelid, and face, there were also yellowish nodules below the tongue and on the hard palate. Phylogenetic analysis of the 4b core protein gene showed that the APV is very close to that found in white-tailed sea eagle (Haliaeetus albicilla) in Japan recently. Because both cases are located on the same major flyway for migratory birds, the impact of this virus with regard to the wild and migratory raptor species along the East Asian-Australasian Flyway and West Pacific Flyway requires immediate investigation.

First Report of Pepper mottle virus in Bell Pepper in Taiwan

Bell pepper (Capsicum annuum L.) plants exhibiting systemic mild mosaic, vein yellowing, and leaf malformation were collected from Puli City in 2006. Double-antibody sandwich (DAS)-ELISA was used to test these samples for Chilli veinal mottle virus (ChiVMV) infection using polyclonal antibodies. In addition, Chenopodium quinoa, C. amaranticolor, and Nicotiana benthamiana plants were mechanically inoculated with sap extracted from collected samples. Ten days postinoculation, chlorotic local lesions were observed on inoculated leaves of C. quinoa and C. amaranticolor plants, whereas, systemic mosaic and foliar distortion symptoms were developed on upper leaves of N. benthamiana plants. The DAS-ELISA test showed that field-collected pepper samples and inoculated leaves of C. quinoa and C. amaranticolor were infected with ChiVMV, while N. benthamiana with mosaic symptoms did not react with ChiVMV antibodies. To confirm ChiVMV, field-collected samples as well as mechanically inoculated plants were tested by reverse transcription (RT)-PCR using the potyvirus degenerate primers Hrp5/Pot1 (2). Amplified RT-PCR products were cloned and sequenced. Sequence analysis of amplified fragments (1.4 kb) revealed that field-collected pepper samples were infected with ChiVMV and Pepper mottle virus (PepMoV). The DNA fragment amplified from C. quinoa and C. amaranticolor showed high (99.2%) sequence identities with the CP gene of ChiVMV (3) (GenBank Accession No. AM909717). However, amplicons obtained from N. benthamiana plants (GenBank Accession No. HQ329082) that showed mosaic symptoms showed 83.6% to 98.7% nucleotide identities with PepMoV (GenBank Accession Nos. AB126033, AF227728, AF440801, AF501591, EU586133, and M96425). Next, a pure isolate of PepMoV was established on N. benthamiana by mechanical inoculation of diluted plant sap obtained from a PepMoV-infected N. benthamiana plant. Bell pepper plants inoculated with the Taiwan isolate of PepMoV developed mosaic and leaf distortion symptoms. Antiserum against the PepMoV Taiwan isolate was subsequently prepared by immunizing rabbits with purified virus particles. Using the prepared antiserum and specific primers (1) to detect PepMoV, ChiVMV, and Pepper veinal mottle virus (PVMV), three viruses could be readily detected and differentiated from diseased bell peppers in the field. In a survey done in 2007, 18 of 33 pepper samples from southern Taiwan were found with mixed infections of PepMoV and ChiVMV, seven samples were infected with PepMoV and PVMV, five samples were infected with PVMV, and another three samples were infected with ChiVMV. To our knowledge, this is the first report of the occurrence of PepMoV in bell peppers in Taiwan. References: (1) Y. H. Cheng et al. Plant Dis. 93:107, 2009. (2) S. S. Pappu et al. Plant Dis. 82:1121, 1998. (3) W. S. Tsai et al. Plant Pathol. 58:408, 2008.

2-Methoxystypandrone represses RANKL-mediated osteoclastogenesis by down-regulating formation of TRAF6-TAK1 signalling complexes

BACKGROUND AND PURPOSE

2-Methoxystypandrone (2-MS) is a naphthoquinone isolated from Polygonum cuspidatum, a Chinese herb used to treat bone diseases. Here we have determined whether 2-MS antagonised osteoclast development and bone resorption.

EXPERIMENTAL APPROACH

RAW264.7 cells were treated with receptor activator of nuclear factor kappaB (NF-kappaB) ligand (RANKL) to induce differentiation into osteoclasts. RT-PCR and Western blot were used to analyse osteoclast-associated gene expression and signalling pathways.

KEY RESULTS

The number of multinuclear osteoclasts, actin rings and resorption pit formation were markedly inhibited by 2-MS, targeting osteoclast differentiation at an early stage and without significant cytotoxicity. The anti-resorption effect of 2-MS was accompanied by decreasing dendritic cell-specific transmembrane protein and matrix metalloproteinase-9 (MMP-9) mRNA expression. RANKL-increased MMP-9 gelatinolytic activity was also attenuated by concurrent, but not by subsequent addition of 2-MS. 2-MS markedly inhibited not only the RANKL-triggered nuclear translocations of NF-kappaB, c-Fos and nuclear factor of activated T cells c1 (NFATc1), but also the subsequent NFATc1 induction. Degradation of IkappaB and phosphorylation of mitogen-activated protein kinases were also suppressed. RANKL facilitated the formation of signaling complexes of tumour necrosis factor receptor-associated factor 6 and transforming growth factor beta-activated kinase 1 (TRAF6-TAK1), important for osteoclastogenesis and formation of such signalling complexes was prevented by 2-MS.

CONCLUSIONS AND IMPLICATIONS

The anti-osteoclastogenic effects of 2-MS could reflect the block of RANKL-induced association of TRAF6-TAK1 complexes with consequent decrease of IkappaB-mediated NF-kappaB and mitogen-activated protein kinases-mediated c-Fos activation pathways and suppression of NFATc1 and other gene expression, essential for bone resorption.

Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge

Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

Using silicon nanowire devices to detect adenosine triphosphate liberated from electrically stimulated HeLa cells

In this study, we used a biosensor chip featuring Abl tyrosine kinase-modified silicon nanowire field-effect transistors (SiNW-FETs) to detect adenosine triphosphate (ATP) liberated from HeLa cells that had been electrically stimulated. Cells that are cultured in high-ionic-strength media or buffer environments usually undermine the sensitivity and selectively of SiNW-FET-based sensors. Therefore, we first examined the performance of the biosensor chip incorporating the SiNW-FETs in both low- and high-ionic-strength buffer solutions. Next, we stimulated, using a sinusoidal wave (1.0 V, 50 Hz, 10 min), HeLa cells that had been cultured on a cell-culture chip featuring interdigitated electrodes. The extracellular ATP concentration increased by ca. 18.4-fold after electrical stimulation. Finally, we detected the presence of extracellular ATP after removing a small amount of buffer solution from the cell-cultured chip and introducing it into the biosensor chip.

Cr(VI) removal on fungal biomass of Neurospora crassa: the importance of dissolved organic carbons derived from the biomass to Cr(VI) reduction

Interactions of toxic Cr(VI) with renewable biomaterials are considered an important pathway for Cr(VI) removal in ecosystems. Biomaterials are susceptible to dissolution, and their dissolved derivatives may provide an alternative to surface-involved pathway for scavenging of Cr(VI). In this study, dissolved organic carbon (DOC) derived from Neurospora crassa biomass was investigated. The proportion of Cr(VI) reduction by DOC to that on biomass was determined to evaluate the importance of DOC to Cr(VI) reduction. A rapid increase in DOC concentration from 145.6 to 193.7 mg L(-1) was observed when N. crassa-biomass was immersed in 0.01 M KCl solution at pH of 1-5, and polysaccharides, peptides, and glycoproteins with carboxyl, amide, and -NH functional groups, are the major compositions of DOC. On reaction of 96.2 microM Cr(VI) with N. crassa-biomass or DOC, it was estimated that DOC contributed approximately 53.8-59.5% of the total Cr(VI) reduction on biomass in the dark. Illumination enhanced Cr(VI) reduction via photo-oxidation of biomass/DOC under aeration conditions, which formed superoxide for Cr(VI) reduction. At pH 1, photoinduced Cr(VI) reduction by DOC proceeded more rapidly than reduction on the biomass surface. However, at pH >3, with a decrease in Cr(VI) reduction by DOC, photon-excited biomass may become an important electron source for Cr(VI) photoreduction.

Armigeres subalbatus (Diptera: Culicidae) prophenoloxidase III is required for mosquito cuticle formation: ultrastructural study on dsRNA-knockdown mosquitoes

We previously suggested that Armigeres subalbatus (Coquillett) prophenoloxidase III (As-pro-PO III) might be associated with morphogenesis of larvae and pupae. Because PO and its activation system are present in the insect cuticle, and cuticle formation is a major event during pupal morphogenesis, we used ultrastructural analysis to examine the effects of As-pro-PO III knockdown on the formation of pupal and adult cuticle. Inoculation of As-pro-PO III dsRNA resulted in the incomplete formation of nascent pupal endocuticle and pharate adult cuticle, i.e., significantly fewer cuticular lamellae were deposited, the helicoidal pattern of chitin microfibrils was disorganized, and numerous electron-lucent spaces were present in the cuticular protein matrix. Similar disruptions were observed in the cuticle of adults derived from As-pro-PO III dsRNA-inoculated pupae. It has long been suggested that the quinines, generated by PO-catalyzed oxidation reactions, function as cross-linking agents; therefore, it seems reasonable to suggest that the loss of As-pro-PO III-mediated protein-protein linkages causes morphological abnormalities in the protein matrix. Our findings suggest that As-pro-PO III plays a role in cuticle formation in mosquitoes, a novel function for phenol-oxidizing enzymes.

Sectional anatomy of the olfactory pathways

AIM

The purpose of this study was to provide practical anatomic data for imaging diagnosis of olfactory pathways and operation of nasal cavity and anterior cranial fossae.

METHODS

Sectional anatomy of olfactory pathways were investigated specially on 17 sets of Chinese adult cadavers and 9 sets of serial magnetic resonance (MR) imaging of normal adult on serial transverse, sagittal and coronal sections respectively.

RESULTS

We recognized olfactory bulb, olfactory tract, medial and lateral olfactory striae, olfactory trigone, anterior perforated substance and piriform lobe on transverse, sagittal and coronal sections respectively. On the 5-7 serial coronal sections from crista galli of ethmoid bone to the optic chiasm, the cusp ellipse olfactory bulb and the triangular tract were situated in the shallow part of the olfactory sulcus.

CONCLUSION

The olfactory bulb and olfactory tract lay tightly on the ethmoidal cribriform plate and jugum sphenoidale, in the olfactory cistern of the shallow part of the olfactory sulcus, the ethmoid sinus and sphenoid sinus inferiorly.

Comparison of photodegradative efficiencies and mechanisms of Victoria Blue R assisted by Nafion-coated and fluorinated TiO2 photocatalysts

The purposes of this research were to study the effects of two modified photocatalysts, Nafion-coated TiO(2) and fluorinated TiO(2), and photocatalytic degradation of Victoria Blue R in aqueous solution. Photocatalytic degradation of Victoria Blue R was accelerated by the modified photocatalysts. Bulk and surface characterizations of the resulting powders were carried out. Attachment of the anions to the TiO(2) surface using the Nafion-coated-TiO(2) possibly results in increased adsorption of the cationic dye, and the degradation rate is larger for the cationic dye. It was found that Victoria Blue R on the two illuminated TiO(2) surfaces underwent very different changes. To obtain a better understanding on the mechanistic details of this modified-TiO(2)-assisted photodegradation of the Victoria Blue R dye with UV irradiation, a large number of intermediates of the process were separated, identified, and characterized by a high-performance liquid chromatography-mass spectrometry technique. Several probable photodegradation pathways were proposed and discussed.

First Report of Capsicum chlorosis virus Infecting Amaryllis and Blood Lily in Taiwan

Capsicum chlorosis virus (CaCV), a thrips-transmitted, tentative species in the genus Tospovirus, family Bunyaviridae, was first identified in solanaceous crops, but also infects several ornamental crops such as orchid (4), gloxinia (3), and calla lily (1). From 2005 to 2007, virus-like yellow ringspots were observed on the leaves of amaryllis (Hippeastrum hybridum Hort.) and blood lily (Haemanthus multiflorus Martyn.) plants cultured in screenhouses and a private garden, respectively. Three of several hundred amaryllis plants in screenhouses from two places were observed as showing yellow ringspot symptoms and one of six blood lily plants was observed as showing similar yellow ringspot symptoms. Sap extracts from symptomatic leaves were inoculated to Chenopodium quinoa Willd. and the resulting local lesions were passaged three successive times to C. quinoa for virus isolation. Using the tospovirus genus-specific primers gL3637 and gL4435c designed from the conserved region in the L RNA (2), DNA fragments of the expected size of 800 bp were amplified by reverse transcription (RT)-PCR from field samples and local lesions from C. quinoa. Extracts from the diseased plants and local lesions of C. quinoa reacted strongly with antiserum against the nucleocapsid (N) protein of CaCV in ELISA and western blotting. To confirm the identity of this virus, we amplified the N gene from three amaryllis and one blood lily source using primer pair WN2328 and WN3534 designed from the S RNA of Watermelon silver mottle virus (1), and these products were cloned and sequenced. The sequence from each virus isolate was determined from three independent clones. The nucleotide and deduced amino acid sequences of N genes for the blood lily isolate (GenBank Accession No. EF101344) and three amaryllis isolates (GenBank Accession Nos. EF101343, EF137177, and FJ185170) had identities greater than 97% with that of a CaCV isolate infecting Capsicum spp. found in Australia (GenBank Accession No. AY036057). Phylogenetic analysis using maximum parsimony showed that these sequences clustered with CaCV. These results show that the virus identified from amaryllis and blood lily that were expressing yellow ringspot symptoms are isolates of CaCV. To our knowledge, this is the first report of CaCV naturally infecting amaryllis and blood lily and it could become an important threat to ornamental production in Taiwan. References: (1) C. C. Chen et al. Plant Dis. 91:1201, 2007. (2) F. H. Chu et al. Phytopathology 91:361, 2001. (3) H. T. Hsu et al. J. Gen. Plant Pathol. 66:167, 2000. (4) Y. X. Zheng et al. Eur. J. Plant Pathol. 120:199, 2008.

Chromate reduction by zero-valent Al metal as catalyzed by polyoxometalate

In spite of a high reduction potential of zero-valent Al (ZVAl), its ability to reduce Cr(VI), a widespread pollutant, to less toxic Cr(III) remains to be uncovered. In the present study, Cr(VI) reduction by ZVAl was conducted to evaluate the potential application of Al as a reductant for Cr(VI). Polyoxometalate (POM, HNa(2)PW(12)O(40)), a catalyst, was used to accelerate Cr(VI) reduction by Al. The reaction of 0.192mM Cr(VI) on ZVAl was investigated in the presence of N(2) or O(2) at pH 1. A slight decrease in Cr(VI) concentration was observed on as-received (uncleaned) ZVAl due to the presence of oxide layer with a low surface area (ca. 3.4x10(-3)m(2)/g) of ZVAl. On addition of 0.1mM POM, Cr(VI) reduction on uncleaned ZVAl increased significantly. This is attributed to the unique properties of POM, which has a Brphinsted acidity higher than usual inorganic acids such as H(2)SO(4) and HCl. Thus, POM could remove rapidly the oxidize layer on ZVAl, followed by acting as a shuttle for electron transfer from ZVAl to Cr(VI). Under a N(2) atmosphere, one- or two-electron reduction of POM by ZVAl was responsible for Cr(VI) reduction in the early stage of the reaction. However, during reaction with ZVAl over 120min, three-electron reduction of POM predominated over Cr(VI) reduction. On interaction of O(2) with reduced POM, the formation of H(2)O(2) was responsible for subsequent Cr(VI) reduction. The results suggest that POM is an efficient catalyst for Cr(VI) reduction by Al due to the extremely rapid consumption of reduced POM or H(2)O(2) by Cr(VI).

Patient-driven loop control for ambulation function restoration in a non-invasive functional electrical stimulation system

PURPOSE

In this study, a patient-driven loop control in a non-invasive functional electrical stimulation (FES) system was designed to restore ambulation function of patients with stroke with their residual capabilities.

METHOD

With this patient-driven loop control, patients use the electromyographic (EMG) signals from their voluntary controlled muscles in affected extremity to adjust stimulus parameters of the system. A special designed FES system generated electrical stimuli to excite the paralysed muscles through surface electrodes on the basis of the control command from the residual myoelectric signals. The EMG signals were also served as the trigger and the adjustment of stimulus parameters and thereby adding versatility of the FES system. One patient with hemiplegia was recruited to conduct clinical evaluation and treated by using the new closed-loop FES system.

RESULTS

The experimental results showed that hemiplegic could successfully control the system to restore their lost ambulation functions with the strategy of patient-driven loop control. It is revealed that the mean velocity, cadence, stride length, active ankle motion range and functional ambulation category have improved significantly from 0.22 + or - 0.17 m/s, 37.3 + or - 15.5 steps/min, 0.32 + or - 0.11 m, 10 degrees , level 2 to 0.46 + or - 0.23 m/s, 58.2 + or - 19.1 steps/min, 0.73 + or - 0.22 m, 35 degrees , level 4 respectively for the patient. A paired t-test indicated that differences in the EMG of the tibialis anterior and the gastrocnemius muscles between patient's disabled (affected-side) foot and normal (unaffected-side) foot are not significant (p > 0.05) after 12 weeks of training.

CONCLUSIONS

According to the experiment results, this patient-driven loop control can be beneficial for patient with hemiplegia to restore their ambulation functions such as dorsi-flexion and plantar-flexion. The control strategy of this study has the potential to be employed not only in the FES system but also in other assistive devices.

Nanocontact resistance and structural disorder induced resistivity variation in metallic metal-oxide nanowires

Several systems of metallic metal-oxide nanowires (NWs), including pure RuO2 and as-implanted and annealed Ru(0.98)Cu(0.02)O2 and Ru(0.93)Cu(0.07)O2 NWs, have been employed in two-probe electrical characterizations by using a transmission electron microscope-scanning tunneling microscope technique with a gold tip. Thermal, mechanical, and electron beam exposing treatments are consecutively applied to reduce the electrical contact resistance, generated from the interface between the NW and the gold tip, so as to evaluate the intrinsic NW resistance. It is found that the residual contact resistance cannot be entirely removed. For each system of metallic metal-oxide NWs, several tens of NWs are applied to electrical characterizations and the total resistances unveil a linear dependence on the ratio of the length to the area of the NWs. As a result, the average resistivity and the contact resistance of the metallic metal-oxide NWs could be evaluated at room temperatures. The average resistivities of pure RuO2 NWs agree well with the results obtained from standard two- and four-probe electrical-transport measurements. In addition, the as-implanted Cu-RuO2 NWs reveal disordered crystalline structures in high-resolution TEM images and give higher resistivities in comparison with that of pure RuO2 NWs. The residual contact resistances of all kinds of metallic metal-oxide NWs unveil, more surprisingly, an approximation value of several kilohms, even though the average resistivities of these NWs change by more than one order of magnitude. It is argued that the ductile gold tip makes one or more soft contacts on the stiff metal-oxide NWs with nanometer roughness and the nanocontacts on the NWs contribute to the electrical contact resistance.

Water-assisted CO(2) laser ablated glass and modified thermal bonding for capillary-driven bio-fluidic application

The glass-based microfluidic chip has widely been applied to the lab-on-a-chip for clotting tests. Here, we have demonstrated a capillary driven flow chip using the water-assisted CO(2) laser ablation for crackless fluidic channels and holes as well as the modified low-temperature glass bonding with assistance of adhesive polymer film at 300 degrees Celsius. Effect of water depth on the laser ablation of glass quality was investigated. The surface hydrophilic property of glass and polymer film was measured by static contact angle method for hydrophilicity examination in comparison with the conventional polydimethylsiloxane (PDMS) material. Both low-viscosity deionized water and high-viscosity whole blood were used for testing the capillary-driving flow behavior. The preliminary coagulation testing in the Y-channel chip was also performed using whole blood and CaCl(2) solution. The water-assisted CO(2) laser processing can cool down glass during ablation for less temperature gradient to eliminate the crack. The modified glass bonding can simplify the conventional complex fabrication procedure of glass chips, such as high-temperature bonding, long consuming time and high cost. Moreover, the developed fluidic glass chip has the merit of hydrophilic behavior conquering the problem of traditional hydrophobic recovery of polymer fluidic chips and shows the ability to drive high-viscosity bio-fluids.

Rapid diagnosis of tuberculosis directly from clinical specimens using a gene chip

The aim of this study was to explore a gene chip capable of detecting the presence of Mycobacterium tuberculosis isolates directly in clinical sputum specimens and to compare it with current molecular detection techniques. At first, we selected 13 M. tuberculosis-specific target genes to construct a gene chip for rapid diagnosis. Using the membrane array method, we diagnosed M. tuberculosis by gene chip directly from 246 sputum specimens from patients suspected of having tuberculosis. Among 80 M. tuberculosis complex (MTBC) culture-positive sputum specimens, the MTBC detection rate was 62.5% (50/80) by PCR-restriction fragment length polymorphism (RFLP), 70% (56/80) by acid-fast staining, and 85% (68/80) by the membrane array method. Furthermore, subspecies showed different gene expression patterns in the membrane array. In conclusion, MTBC could be detected directly in sputum by the membrane array method. The rapidity of detection and the capability of differentiating subspecies could make this method useful in the control and prevention of tuberculosis.

Exploring the origin of the directional emission from a microcavity with a large-aperture surface-emitting laser

The origin of the direction emission from a microcavity is investigated with a large-aperture surface-emitting laser with an equilateral-triangular shape. Experimental results reveal that a wide-spread eigenmode and a localized superscar mode can display quite similar far-field directional emissions. This experimental finding is theoretically confirmed with the quantum-billiard wave function and the approximation of the paraxial propagation.

Combined treatment with denbinobin and Fas ligand has a synergistic cytotoxic effect in human pancreatic adenocarcinoma BxPC-3 cells

BACKGROUND AND PURPOSE

Human pancreatic carcinoma is a highly malignant cancer. Previous studies have shown that the decoy receptor 3 (DcR3) for Fas ligand (FasL) plays significant roles in tumour progression and immune suppression. In the present study, we evaluated the anti-cancer activity of a natural compound, denbinobin (5-hydroxy-3,7-dimethoxy-1,4-phenanthraquinone), through decreasing DcR3 levels in human pancreatic adenocarcinoma cell lines.

EXPERIMENTAL APPROACH

We used immunoprecipitation and ELISA assays to examine DcR3 levels, and used FACS to determine the percentage of cells with a sub-G1 DNA content.

KEY RESULTS

AsPC-1 and BxPC-3 human pancreatic cancer cells express high levels of DcR3. Denbinobin concentration-dependently decreased DcR3 levels in BxPC-3 cells. MTT and flow cytometry assays indicated that BxPC-3 was FasL-resistant because high concentrations (100 ng.mL(-1)) of soluble FasL did not inhibit cell growth. However, combinations of denbinobin (3 micromol.L(-1)) with lower concentrations of soluble FasL (10, 30 and 50 ng.mL(-1)) or membrane-bound FasL, were synergistic on cell growth inhibition and apoptosis. Exogenous excess DcR3 reversed this synergistic effect. We observed no significant increase in the levels of surface Fas, cleaved forms of caspase-8, -3, -9, Bax, Bid, Bcl-xL, cytochrome c or mitochondrial membrane potentials following denbinobin treatment. However, denbinobin treatment increased the levels of apoptosis-inducing factor.

CONCLUSIONS AND IMPLICATIONS

Denbinobin and FasL trigger a synergistic cytotoxic effect in human pancreatic adenocarcinoma cells. Denbinobin mediated a decrease in levels of DcR3, which played a major role in this synergistic effect, and also increased caspase-independent apoptosis, via apoptosis-inducing factor.

Malignancies associated with dermatomyositis and polymyositis in Taiwan: a nationwide population-based study

BACKGROUND

Previous studies showed that idiopathic inflammatory myopathies (IIM) carried an increased risk of cancers. However, no large-scale study of IIM has been conducted in the Chinese population.

OBJECTIVES

We sought to delineate the association of IIM and various cancer types from a nationwide database in Taiwan.

METHODS

We analysed the published national data from records of National Health Insurance claims. Cases of dermatomyositis (DM) and polymyositis (PM) from 2000 to 2005 and cancers registered in the catastrophic illness profile from 1997 to 2006 were collected. A nationally representative cohort of 1,000,000 enrollees was included for comparison.

RESULTS

In total, 136 patients (12.8%) among 1059 cases of DM and 46 persons (7.0%) among 661 cases of PM carried internal malignancies. Patients with DM tended to have cancers of nasopharynx, lung and breast. On the other hand, patients with PM tended to have breast, uterine cervix and lung cancers. Compared with the general population, DM gave a 10-fold increased risk for cancers, in which a 66-fold increased risk for nasopharyngeal carcinoma and a 31-fold increased risk for lung cancer were the two most significant. For patients with PM, a 6-fold increased risk for cancer was observed. Juvenile DM had a 16-fold increased risk for haematopoietic or lymphoid malignancy. Two thirds of comorbid malignancies were detected shortly after the diagnoses of IIM, within a mean of 1-2 years. Overall, younger patients with IIM carried the highest risk for malignancies, especially those in their twenties and thirties.

CONCLUSIONS

This is the first large-scale study to report the associated malignancies and the cancer risk of IIM in Taiwan.

The synthesis and characterization of [(124)I]IMPY, a thioflavin-S derivative, in transgenic mouse models of Alzheimer's disease

6-[(124)I]iodo-2-(4'-N,N-dimethylamino)-phenylimidazo[1,2-a]pyridine ([(124)I]IMPY) was synthesized and characterized as a positron-emitting probe to identify Alzheimer's disease in transgenic mouse models. A significant reduction in radioactivity retention in the hippocampus and frontal cortex by co-incubation with nonradioactive IMPY was observed. Highly specific retention of radioactivity in beta-amyloid-rich regions of brain sections was also noted. This study demonstrated that [(124)I]IMPY was a promising probe for the mouse model and may be useful for positron emission tomography to image beta-amyloid plaques in the human brain.

Full-length sequence analysis of a distinct isolate of Bidens mottle virus infecting sunflower in Taiwan

The full-length genome of a potyvirus, previously known as sunflower chlorotic spot virus isolate SF-1 (SCSV-SF-1) which causes novel symptoms on sunflowers (Helianthus annuus), was sequenced and analyzed. The genome of SCSV-SF-1 is 9,741 nucleotides long, encoding a polyprotein of 3,071 amino acids containing the consensus motifs of potyviruses. Sequence comparison revealed that the 3'-terminus of SCSV-SF-1 shared over 96% similarities with isolates of Bidens mottle virus (BiMoV). However, SCSV-SF-1 has a very narrow host range, excluding the diagnostic host species for BiMoV, Bidens pilosa and Zinnia elegans. Therefore, SCSV-SF-1 is a distinct isolate of BiMoV. This is the first report of the full-length nucleotide sequence of BiMoV infecting sunflower in Taiwan.

Correlated electric fluctuations in GaN nanowire devices

We report an experimental study on the correlation spectrums between different sections of a multi-contact GaN nanowire device. Our results indicate that there exists a negative correlation between the voltage fluctuations of adjacent sections of the nanowire separated by a metal contact in the transition region between the low-frequency 1/f noise and the high-frequency white thermal noise. We suggest that this correlation is caused by the voltage fluctuation under the contact area.

Transient dynamics of coherent waves released from quantum billiards and analogous observation from free-space propagation of laser modes

The transient dynamics of the eigenstates and coherent states released from a square quantum billiard is analytically and numerically investigated. It is experimentally verified that this transient dynamic can be analogously observed with the free-space propagation of the lasing modes emitted from the laterally confined, vertically emitted cavities. Furthermore, we exploit a chaotically shaped cavity to originally demonstrate the diffraction-in-time characteristics of the chaotic wave functions. It is found that the transient patterns of chaotic wave functions exhibit a striking feature of random branching behavior with the appearance of intricate interference fringes.

Gabapentin toxicity: an important cause of altered consciousness in patients with uraemia

Gabapentin toxicity should be considered one of the differential diagnoses of altered consciousness in patients with compromised renal function, even after a single dose. We report a 57-year-old woman with diabetes mellitus and uraemia on regular haemodialysis who developed severe dizziness and lethargy after a single recommended dose of gabapentin for bilateral leg dysthesia. Because of progressive drowsiness and decreasing level of consciousness, one session of haemodialysis was performed and clinical recovery was dramatic. The adverse effects of gabapentin seem to vary from person to person and should be viewed with a high degree of suspicion, especially in patients taking this drug at the beginning.

First Report of Pepper veinal mottle virus in Tomato and Pepper in Taiwan

In May of 2006, samples from tomato plants (Solanum lycopersicum cv. Known-you 301) exhibiting necrotic symptoms on stems, petioles, and leaves were collected from Chiayi County, Taiwan. Double-antibody sandwich-ELISAs were performed using Cucumber mosaic virus, Tomato mosaic virus, Potato virus Y, Watermelon silver mottle virus, and Chilli veinal mottle virus (ChiVMV) polyclonal antibodies. Three of eight samples reacted with antibodies against ChiVMV but not with the others. Using the potyvirus degenerate primers (Hrp 5/Pot 1) (2), an expected 1.5-kb DNA fragment including the 3'-end of the NIb gene, the complete coat protein (CP) gene, and the 3'-nontranslatable region of the virus was amplified from total RNA isolated from these three samples by reverse transcription (RT)-PCR. A homology search in GenBank indicated that the new tomato-infecting virus in Taiwan belongs to Pepper veinal mottle virus (PVMV) since they shared >90% amino acid identity in the CP gene. A virus culture (Tom1) isolated from one of the diseased tomatoes was then established in Chenopodium quinoa and Nicotiana benthamiana and the CP gene was amplified and sequenced (GenBank Accession No. EU719647). Comparisons of the 807-nt CP gene with those of five PVMV isolates available in GenBank showed 81.5 to 93.1% nucleotide and 90.0 to 97.8% amino acid identity. Tom1 induced irregular necrotic lesions on stems, petioles, and leaves of tomato while inducing only mild mottle symptoms on pepper. Serological cross reaction between ChiVMV and PVMV has been observed previously (1,3) and also found in this study. To differentiate these two potyviruses by RT-PCR, primer pair CPVMVup/dw (5'-TATTC(T/C)TCAGTGTGG(A/T/C)T(T/C)CCACCAT and 5'-(T/C)C(A/T)C(A/T)(A/T/G)(A/T)AA(A/G)CCATAA(A/C)(A/C)ATA(A/G)T(T/C)T) was designed on the basis of the comparison of the CP gene and the 3'-nontranslatable region of the PVMV and ChiVMV. DNA fragments of 171 and 259 bp are expected to be amplified from ChiVMV and PVMV, respectively, by RT-PCR with primers CPVMVup/dw. In a field survey done in 2006, samples from diseased peppers (Capsicum annuum) that reacted with the polyclonal antibodies against ChiVMV were further identified by RT-PCR with primers CPVMVup/dw, indicating that both ChiVMV and PVMV infected pepper crops (Capsicum spp.) in Taiwan. A pepper isolate (Pep1) of PVMV was obtained from Nantou County through three times of single lesion passages on C. quinoa and then propagated on N. benthamiana. The CP gene of Pep1 was amplified and sequenced (GenBank Accession No. EU719646) and found to share 99.1% nucleotide and 100% amino acid identity with that of Tom1. Pep1 caused mild mottle symptoms on leaves of both tomato and pepper. To our knowledge, this is the first report of the presence of PVMV in Taiwan as well as in East Asia. References: (1) B. Moury et al. Phytopathology 95:227, 2005. (2) S. S. Pappu et al. Plant Dis. 82:1121, 1998. (3) W. S. Tsai et al. Plant Pathol. 58:408, 2008.

Forward and backward connections in the brain: a DCM study of functional asymmetries

In this paper, we provide evidence for functional asymmetries in forward and backward connections that define hierarchical architectures in the brain. We exploit the fact that modulatory or nonlinear influences of one neuronal system on another (i.e., effective connectivity) entail coupling between different frequencies. Functional asymmetry in forward and backward connections was addressed by comparing dynamic causal models of MEG responses induced by visual processing of normal and scrambled faces. We compared models with and without nonlinear (between-frequency) coupling in both forward and backward connections. Bayesian model comparison indicated that the best model had nonlinear forward and backward connections. Using the best model we then quantified frequency-specific causal influences mediating observed spectral responses. We found a striking asymmetry between forward and backward connections; in which high (gamma) frequencies in higher cortical areas suppressed low (alpha) frequencies in lower areas. This suppression was significantly greater than the homologous coupling in the forward connections. Furthermore, exactly the asymmetry was observed when we examined face-selective coupling (i.e., coupling under faces minus scrambled faces). These results highlight the importance of nonlinear coupling among brain regions and point to a functional asymmetry between forward and backward connections in the human brain that is consistent with anatomical and physiological evidence from animal studies. This asymmetry is also consistent with functional architectures implied by theories of perceptual inference in the brain, based on hierarchical generative models.

Predictors of mortality in patients with pyogenic liver abscess

BACKGROUND

Pyogenic liver abscess (PLA) is uncommon but potentially life-threatening. The objective of this study was to identify the prognostic factors for PLA.

METHODS

The medical records of 253 patients, 148 men and 105 women with a mean age of 56.4 years (SD : 15.0 years), who were hospitalised due to a PLA between January 1995 and June 2007 were reviewed. The underlying medical disorders, clinical signs and symptoms, laboratory values, imaging studies, microbiological features, treatments, morbidity and mortality were recorded. Factors related to in-hospital case fatality were analysed.

RESULTS

The mean Acute Physiology And Chronic Health Evaluation (APACHE) II score at admission in patients with PLA was 8.7 points (SD 5.4 points). The most common co-existing disease was diabetes mellitus (41.9%), followed by biliary stone disorders (32.0%). Klebsiella pneumoniae was the most frequent pathogen, followed by Escherichia coli. The in-hospital case-fatality rate was 9.1%. Multivariate analysis revealed that gas-forming abscess (p=0.019), multi-drug resistant isolates (p=0.026), anaerobic infection (p=0.045), blood urea nitrogen level >7.86 mmol/l (p=0.004), and APACHE II score > or =15 (p= 0.004) were associated with mortality.

CONCLUSIONS

The prognosis of PLA may depend chiefly on the severity of the basic physical condition and underlying pathology. As the primary treatment for PLA is not completely effective, a more aggressive approach should be considered, especially for patients with poor prognosis.

Broadband and omnidirectional antireflection employing disordered GaN nanopillars

Disordered GaN nanopillars of three different heights: 300, 550, and 720 nm are fabricated, and demonstrate broad angular and spectral antireflective characteristics, up to an incident angle of 60? and for the wavelength range of lambda=300-1800 nm. An algorithm based on a rigorous coupled-wave analysis (RCWA) method is developed to investigate the correlations between the reflective characteristics and the structural properties of the nanopillars. The broadband and omnidirectional antireflection arises mainly from the refractive-index gradient provided by nanopillars. Calculations show excellent agreement with the measured reflectivities for both s- and p- polarizations.

Dynamic causal modelling of induced responses

This paper describes a dynamic causal model (DCM) for induced or spectral responses as measured with the electroencephalogram (EEG) or the magnetoencephalogram (MEG). We model the time-varying power, over a range of frequencies, as the response of a distributed system of coupled electromagnetic sources to a spectral perturbation. The model parameters encode the frequency response to exogenous input and coupling among sources and different frequencies. The Bayesian inversion of this model, given data enables inferences about the parameters of a particular model and allows us to compare different models, or hypotheses. One key aspect of the model is that it differentiates between linear and non-linear coupling; which correspond to within and between-frequency coupling respectively. To establish the face validity of our approach, we generate synthetic data and test the identifiability of various parameters to ensure they can be estimated accurately, under different levels of noise. We then apply our model to EEG data from a face-perception experiment, to ask whether there is evidence for non-linear coupling between early visual cortex and fusiform areas.

Various high-order modes in vertical-cavity surface-emitting lasers with equilateral triangular lateral confinement

Large-aperture vertical-cavity surface-emitting lasers with an equilateral triangular lateral confinement are fabricated to investigate the formation of high-order resonant modes. The experimental lasing patterns are composed of the superscar mode, honeycomb eigenstate, and chaotic mode. Experimental results confirm the theoretical predictions that tiny symmetry breaking can cause the high-order modes to reveal miscellaneous states of integrable and chaotic systems.

First Report of Capsicum chlorosis virus Causing Yellow Stripes on Calla Lilies in Taiwan

Tomato spotted wilt virus (TSWV) and Calla lily chlorotic spot virus (CCSV) are two recognized species of the Tospovirus genus in the family Bunyaviridae infecting calla lily (Zantedeschia spp.). During 2005, 15 virus isolates were collected from different calla lily plants exhibiting yellow stripes on their leaves in Ho-Li, a major calla lily-production township in Taiwan. After three successive local lesion passages on Chenopodium quinoa Willd., diseased leaf tissues individually infected by these isolates were preserved in liquid nitrogen and used for subsequent identification studies. Using the tospovirus genus-specific primers gL3637 and gL4435c designed from the L RNA, an 800-bp DNA fragment was amplified in reverse transcription-PCR from all 15 isolates. Moreover, leaf extracts of the diseased calla lilies and the C. quinoa plants inoculated with the 15 virus isolates reacted with antisera against the nucleocapsid proteins (NP) of Capsicum chlorosis virus (CaCV)-gloxinia and Watermelon silver mottle virus (WSMoV), but not to monoclonal antibodies against the NP of TSWV, CCSV, Peanut chlorotic fan-spot virus (PCFV), or Impatiens necrotic spot virus (INSV) in indirect ELISA. These results indicate that the 15 virus isolates are tospoviruses belonging to the WSMoV serogroup. Additionally, we amplified and sequenced the full-length N gene from these tospovirus isolates using primers WN2328 (5'-CCATTGGTTTGCCTCCG-3') and WN3534 (5'-CGTCGACAGAGCAATCGAGGC-3') designed from the S RNA of WSMoV. The deduced amino acid sequences of the N protein from these 15 tospovirus isolates showed a greater than 92% identity to that of CaCV (GenBank Accession No. NC-008301). Furthermore, results of phylogenetic analysis of the 15 isolates on the basis of amino acids sequences, both genetic distance and parsimony trees indicated that they were all genetically clustered within CaCV using INSV, TSWV, and WSMoV as outgroups. The results indicate that the virus causing yellow stripes in calla lilies is a strain of CaCV. To our knowledge, this is the first evidence that CaCV can naturally infect calla lilies and cause yellow stripe symptoms. Reference: (1) F.-H. Chu et al. Phytopathology 91:361, 2001.

Regulation of steroidogenesis by Cordyceps sinensis mycelium extracted fractions with (hCG) treatment in mouse Leydig cells

The in vitro effect of extracted fractions of Cordyceps sinensis (CS) mycelium on hCG-treated testosterone production from purified normal mouse Leydig cells was examined. Different fractions extracted from CS (F1-water soluble polysaccharide, F2- water soluble protein and F3- poorly water soluble polysaccharide, and protein) were added to Leydig cells with hCG, and the production of testosterone was determined by radioimmunoassay (RIA). Testosterone productions stimulated by hCG in mouse Leydig cells were suppressed by F2 at 10 mg/ml and F3 at doses from 3 to 10 mg/ml, respectively. F2 and F3 at 10 mg/ml did inhibit dbcAMP-stimulated testosterone productions which indicated that F2 and F3 might affect steroidogenesis at the site after the formation of cyclic AMP. Finally, cycloheximide inhibited F2- and F3-treated mouse Leydig cell testosterone production.

The subthalamic region is activated during valence-related emotional processing in patients with Parkinson's disease

Visual stimuli are judged for their emotional significance based on two fundamental dimensions, valence and arousal, and may lead to changes in neural and body functions like attention, affect, memory and heart rate. Alterations in behaviour and mood have been encountered in patients with Parkinson's disease (PD) undergoing functional neurosurgery, suggesting that electrical high-frequency stimulation of the subthalamic nucleus (STN) may interfere with emotional information processing. Here, we use the opportunity to directly record neuronal activity from the STN macroelectrodes in patients with PD during presentation of emotionally laden and neutral pictures taken from the International Affective Picture System (IAPS) to further elucidate the role of the STN in emotional processing. We found a significant event-related desynchronization of STN alpha activity with pleasant stimuli that correlated with the individual valence rating of the pictures. Our findings suggest involvement of the human STN in valence-related emotional information processing that can potentially be altered during high-frequency stimulation of the STN in PD leading to behavioural complications.

Generation of two-dimensional chaotic vector fields from a surface-emitting semiconductor laser: analysis of vector singularities

We demonstrate experimental generation of two-dimensional (2D) chaotic vector fields from a surface-emitting microcavity laser with precisely control of the operating temperature and the operating current. The 2D optical vector field is found to be formed by frequency locking of two linearly polarized laser modes with different chaotic spatial structures. The eigenfunction expansion method is used to reconstruct the experimental wave function for analyzing the properties of the vector singularities. It is shown that the distribution of vector singularities obeys the sign rule of nearest-neighbor singularities in the phase space of the vector field.