Composition and structure of Pinus koraiensis mixed forest respond to spatial climatic changes

Background

Although some studies have indicated that climate changes can affect Pinus koraiensis mixed forest, the responses of composition and structure of Pinus koraiensis mixed forests to climatic changes are unknown and the key climatic factors controlling the composition and structure of Pinus koraiensis mixed forest are uncertain.

Methodology/principal findings

Field survey was conducted in the natural Pinus koraiensis mixed forests along a latitudinal gradient and an elevational gradient in Northeast China. In order to build the mathematical models for simulating the relationships of compositional and structural attributes of the Pinus koraiensis mixed forest with climatic and non-climatic factors, stepwise linear regression analyses were performed, incorporating 14 dependent variables and the linear and quadratic components of 9 factors. All the selected new models were computed under the +2°C and +10% precipitation and +4°C and +10% precipitation scenarios. The Max Temperature of Warmest Month, Mean Temperature of Warmest Quarter and Precipitation of Wettest Month were observed to be key climatic factors controlling the stand densities and total basal areas of Pinus koraiensis mixed forest. Increased summer temperatures and precipitations strongly enhanced the stand densities and total basal areas of broadleaf trees but had little effect on Pinus koraiensis under the +2°C and +10% precipitation scenario and +4°C and +10% precipitation scenario.

Conclusions/significance

These results show that the Max Temperature of Warmest Month, Mean Temperature of Warmest Quarter and Precipitation of Wettest Month are key climatic factors which shape the composition and structure of Pinus koraiensis mixed forest. Although the Pinus koraiensis would persist, the current forests dominated by Pinus koraiensis in the region would all shift and become broadleaf-dominated forests due to the dramatic increase of broadleaf trees under the future global warming and increased precipitation.

Structure and Composition of Natural Gmelin Larch (Larix gmelinii var. gmelinii) Forests in Response to Spatial Climatic Changes

BACKGROUND

Many theoretical researches predicted that the larch species would decrease drastically in China under future climatic changes. However, responses of the structural and compositional changes of Gmelin larch (Larix gmelinii var. gmelinii) forests to climatic changes have rarely been reported.

METHODOLOGY/PRINCIPAL FINDINGS

Field survey was conducted to examine the structures and compositions of natural Gmelin larch forests along a climatic gradient. Stepwise linear regression analyses incorporating linear and quadratic components of climatic and non-climatic factors were performed on the structural and compositional attributes of those natural Gmelin larch forests. Isothermality, Max Temperature of Warmest Month (TempWarmestMonth), Precipitation of Wettest Month (PrecipWettestMonth), Precipitation Seasonality (PrecipSeasonality) and Precipitation of Driest Quarter (PrecipDriestQuarter) were observed to be effective climatic factors in controlling structure and composition of Gmelin larch forests. Isothermality significantly affected total basal area of larch, while TempWarmestMonth, PrecipWettestMonth and PrecipSeasonality significantly affected total basal area of Mongolian pine, and PrecipDriestQuarter significantly affected mean DBH of larch, stand density of larch and total basal area of spruce and fir.

CONCLUSIONS/SIGNIFICANCE

The summer and winter temperatures and precipitations are all predicted to increase in future in Northeast China. Our results showed the increase of total basal area of spruce and fir, the suppression of regeneration and the decrease of stand density of larch under increased winter precipitation, and the decrease of total basal area of larch under increased summer temperature in the region of current Gmelin larch forest. Therefore, we suggest that larch would decrease and spruce and fir would increase in the region of future Gmelin larch forest.

Multi-armed poly(aspartate-g-OEI) copolymers as versatile carriers of pDNA/siRNA

To search for potential non-viral nucleic acids carriers, a series of novel cationic polymers, multi-armed poly(aspartate-graft-oligoethylenimine) (MP-g-OEI) copolymers were designed and synthesized by grafting different types of oligoethylenimine (OEI) to a multi-armed poly(l-aspartic acid) backbone. The as-synthesized MP-g-OEI copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance and gel permeation chromatography. These MP-g-OEI copolymers (MP423, MP600 and MP1800) exhibited good capacity in condensing nucleic acids (pDNA or siRNA) into nanosized particles (90-150nm) with positive surface charges. Gene transfection activity of the MP-g-OEI copolymers (especially MP1800) showed improved performance compared with PEI25k in both HeLa and CHO cell lines. The silencing efficiency of MP600/siRNA and MP1800/siRNA complexes showed a superior knockdown effect in CT26 and Huh-7 cell lines. Moreover, the MP-g-OEI copolymers exhibited much lower cytotoxicity than PEI25k. Flow cytometric analysis showed that MP-g-OEI copolymers could efficiently mediate the entry of nucleic acids into cells. These results suggest that MP-g-OEI copolymers may be potential non-viral gene carriers for the delivery of nucleic acids in future gene therapy.

Push-pull effects of three plant secondary metabolites on oviposition of the potato tuber moth, Phthorimaea operculella

The push-pull effects of three plant secondary metabolites, azadirachtin, eucalyptol, and heptanal, on the oviposition choices of potato tubers by the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) were tested in the laboratory. Azadirachtin at concentrations from 1.5 to 12 mg/L had a significant repellent effect on oviposition. Eucalyptol at concentrations from 3 to 12 mg/L promoted oviposition. Heptanal promoted oviposition at low concentrations from 0.1875 to 3.0 mg/L but repelled it at higher concentrations from 12 to 24 mg/L. The combination of azadirachtin (12 mg/L) with eucalyptol (3.0 mg/L) resulted in a significant pushpull effect of 56.3% on oviposition. The average maximum push-pull effects occurred with the combinations of azadirachtin with heptanal (12 and 0.375 mg/L, respectively; 38.7% push-pull effect), heptanal with eucalyptol (12 and 6 mg/L, respectively; 31.4% push-pull effect), and heptanal (high concentration) with heptanal (low concentration) (12.0 and 0.375 mg/L, respectively; 25% push-pull effect).

Comparing soil organic carbon dynamics in perennial grasses and shrubs in a saline-alkaline arid region, northwestern China

BACKGROUND

Although semi-arid and arid regions account for about 40% of terrestrial surface of the Earth and contain approximately 10% of the global soil organic carbon stock, our understanding of soil organic carbon dynamics in these regions is limited.

METHODOLOGY/PRINCIPAL FINDINGS

A field experiment was conducted to compare soil organic carbon dynamics between a perennial grass community dominated by Cleistogenes squarrosa and an adjacent shrub community co-dominated by Reaumuria soongorica and Haloxylon ammodendron, two typical plant life forms in arid ecosystems of saline-alkaline arid regions in northwestern China during the growing season 2010. We found that both fine root biomass and necromass in two life forms varied greatly during the growing season. Annual fine root production in the perennial grasses was 45.6% significantly higher than in the shrubs, and fine root turnover rates were 2.52 and 2.17 yr(-1) for the perennial grasses and the shrubs, respectively. Floor mass was significantly higher in the perennial grasses than in the shrubs due to the decomposition rate of leaf litter in the perennial grasses was 61.8% lower than in the shrubs even though no significance was detected in litterfall production. Soil microbial biomass and activity demonstrated a strong seasonal variation with larger values in May and September and minimum values in the dry month of July. Observed higher soil organic carbon stocks in the perennial grasses (1.32 Kg C m(-2)) than in the shrubs (1.12 Kg C m(-2)) might be attributed to both greater inputs of poor quality litter that is relatively resistant to decay and the lower ability of microorganism to decompose these organic matter.

CONCLUSIONS/SIGNIFICANCE

Our results suggest that the perennial grasses might accumulate more soil organic carbon with time than the shrubs because of larger amounts of inputs from litter and slower return of carbon through decomposition.

Soil microbial properties and plant growth responses to carbon and water addition in a temperate steppe: the importance of nutrient availability

BACKGROUND

Global climatic change is generally expected to stimulate net primary production, and consequently increase soil carbon (C) input. The enhanced C input together with potentially increased precipitation may affect soil microbial processes and plant growth.

METHODOLOGY/PRINCIPAL FINDINGS

To examine the effects of C and water additions on soil microbial properties and plant growth, we conducted an experiment lasting two years in a temperate steppe of northeastern China. We found that soil C and water additions significantly affected microbial properties and stimulated plant growth. Carbon addition significantly increased soil microbial biomass and activity but had a limited effect on microbial community structure. Water addition significantly increased soil microbial activity in the first year but the response to water decreased in the second year. The water-induced changes of microbial activity could be ascribed to decreased soil nitrogen (N) availability and to the shift in soil microbial community structure. However, no water effect on soil microbial activity was visible under C addition during the two years, likely because C addition alleviated nutrient limitation of soil microbes. In addition, C and water additions interacted to affect plant functional group composition. Water addition significantly increased the ratio of grass to forb biomass in C addition plots but showed only minor effects under ambient C levels. Our results suggest that soil microbial activity and plant growth are limited by nutrient (C and N) and water availability, and highlight the importance of nutrient availability in modulating the responses of soil microbes and plants to potentially increased precipitation in the temperate steppe.

CONCLUSIONS/SIGNIFICANCE

Increased soil C input and precipitation would show significant effects on soil microbial properties and plant growth in the temperate steppe. These findings will improve our understanding of the responses of soil microbes and plants to the indirect and direct climate change effects.

Preactivation of the interferon signalling in liver is correlated with nonresponse to interferon alpha therapy in patients chronically infected with hepatitis B virus

Interferon alpha (IFN-α) therapy is widely used to treat patients with chronic hepatitis B (CHB) but the sustained response rate is low, and the molecular mechanisms for the ineffectiveness of IFN-α treatments are not known. We screened differentially expressed genes between responders (Rs) and nonresponders (NRs) in patients with CHB treated with IFN-α to explore the molecular basis for treatment failure. Expression profiling was performed on percutaneous needle liver biopsy specimens taken before therapy. Gene expression levels were compared between seven patients who did not respond to therapy (NR) and six who did respond (R). Gene ontology category and KEGG pathway were analysed for differentially expressed genes, and the selected differentially expressed genes were confirmed using real-time polymerase chain reaction. We identified 3592 genes whose expression levels differed significantly between all Rs and NRs (P < 0.05); many of these genes are IFN-stimulated genes (ISGs) and immune-related genes. The ISGs were more highly expressed, while immune-related genes were inhibited in NRs before IFN-α treatment. Two ISGs (CEB1 and USP18) that are linked in an IFN inhibitory pathway are highly expressed in NRs, and a potential antiviral gene ISG20 was inhibited in NRs, suggesting a possible rationale for treatment nonresponse. Patients who do or do not respond to IFN have different liver gene expression profiles before IFN-α treatment. Preactivation of the IFN signalling pathway leading to the increased expression of inhibitory ISGs and inhibition of immune response in the pretreatment livers was associated with treatment failure.

High density and scale-up cultivation of recombinant CHO cell line and hybridomas with porous microcarrier Cytopore

Using porous microcarrier Cytopore and a low-serum medium supplement BIGBEF-3, we have successfully cultivated recombinant CHO cell line CL-11G producing prourokinase and hybridomas producing anti-prourokinase monoclonal antibody in Celligen 1.5 or 5 L bioreactor. The cell density obtained ranged from 1 to 2 x 107 cells mL-1. The yields of prourokinase and monoclonal antibody increased with increasing cell density. As the cells could spontaneously release from and reattach to porous microcarriers, it was very easy to scale-up the cultivation. Thus the bead to bead cell transfer method has been used to scale up the cultivation of CL-11G cells to a 20 L reactor-scale for the pilot production of prourokinase, and also to scale-up the culture of hybridomas for the production of monoclonal antibody for the purification of prourokinase.

Pilot production of u-PA with porous microcarrier cell culture

A recombinant DNA CHO cell line secretingurokinase-type plasminogen activator (u-PA) wascultivated with Cytopore cellulose porousmicrocarriers in a 30l Biostat UC stirred tankreactor. After 26 days of culture, using a spinfilter toretain cells in bioreactor, the cell density couldreach 1.33 x 10(7) ml(-1). The maximal u-PAactivity in supernatant was 7335 IU.ml(-1), and204l supernatant containing 7.1 g u-PA was harvested.After 100 days of culture with 0.1% fetal bovineserum medium, a modified cell retention system whichcan be washed-out backward, substituted thespinfilter to prevent filter clogging. The maximalcell density was over 10(7) ml(-1), the maximalu-PA activity in supernatant reached 6250IU.ml(-1), and 1604l supernatant containing about51 g u-PA was harvested. Compared to perfusionculture, batch medium-replaced culture could raiseutilizing efficiency of the medium, increase cell specificproductivity and improve the quality of the product which wasnot steady in a 37 degrees C environment. Cells can movefrom seed porous microcarriers occupied by cells tovacant microcarriers spontaneously, withouttrypsinization, and continue to grow until all microcarriers contained cells. It shows that Cytoporeporous microcarriers are very useful and convenient toscale up cultivation step by step.

Yin Yang 1 positively regulates BRCA1 and inhibits mammary cancer formation

Expression of the breast cancer-associated gene 1 (BRCA1) in sporadic breast cancers is usually reduced, yet the underlying mechanisms remains elusive. To identify factors that are responsible for reduced BRCA1 expression, we screened 92 known transcription factors for their ability to regulate expression of BRCA1. Among several potential regulators, the Gli-Krueppel-related transcription factor Yin Yang 1 (YY1) showed the most dramatic transactivation of the BRCA1 promoter. YY1 binds to the promoter of BRCA1, and its overexpression resulted in increased expression of BRCA1 and a number of BRCA1 downstream genes. We further showed that overexpression of YY1 in cancer cells inhibited cell proliferation, foci formation and tumor growth in nude mice. To assess the clinical relevance between YY1 and BRCA1, we studied expression of YY1 and BRCA1 from human breast cancer samples and tissue arrays, and detected a significant positive correlation between the level of YY1 and BRCA1 expression in these cancers. Taken together, these findings suggest that YY1 is a key regulator of BRCA1 expression and may be causally linked to the molecular etiology of human breast cancer.

Experience with adrenal schwannoma in a Chinese population of six patients

OBJECTIVES

Benign adrenal schwannoma is an extremely uncommon cause of incidentaloma. This article describes our experience with the diagnosis and treatment of adrenal schwannoma in a Chinese population of 6 patients. To our knowledge, this is the largest series of this uncommon adrenal tumor treated in a single center.

METHODS

From May 1999 to May 2009, 6 patients with incidentally discovered adrenal schwannoma were operated on at a tertiary referral hospital in Eastern China. Clinical details, radiographic features, laboratory examinations, pathological findings, and follow-up data of these patients were analyzed.

RESULTS

Of the 6 patients, 4 were females (F) and 2 were males (M), with a mean age of 40.5 yr (range: 30-47, M:F=2:1). The 6 patients were managed with open unilateral adrenalectomy; 5 patients had schwannomas on the left side, and 1 on right side. Abnormal urine catecholamine was detected in 1 patient. The mean pathological size of these tumors was 4.3 ± 1.1 cm. The diagnosis of schwannoma was based on classic histological findings, and supported by immunohistochemistry of S-100, vimentin, and ABC positivity. In the follow- up of 47.5 ± 32.3 months, no recurrence and metastasis were observed.

CONCLUSIONS

Although there may be some clues for radiological diagnosis of adrenal schwannoma, preoperative misdiagnosis is not infrequent. Those tumors may occasionally have endocrine function. Histological examination is the key of diagnosis, and surgical resection is the treatment of choice once malignancy cannot be excluded by preoperative analyses.

Determination of radial location of rotating magnetic islands by use of poloidal soft x-ray detector arrays in the STOR-M tokamak

A technique is presented for determining the radial location of the rotating magnetic islands in the STOR-M tokamak by use of soft x-ray (SXR) detector arrays. The location is determined by examining the difference in the integrated SXR emission intensities through two adjacent lines of sight. A model for calculating dependence of the line integrated SXR emission intensity on the radius, the mode numbers and the magnetic island geometry, has been developed. The SXR difference signal shows phase inversion when the impact parameter of the line of sight sweeps across the magnetic islands. Experimentally, the difference SXR signals significantly reduce noise and suppress the influence of background plasma fluctuations through common mode rejection when a dominant mode exists in the STOR-M tokamak. The radial locations of the m = 2 magnetic islands have been determined under several experimental conditions in the STOR-M discharges. With the decrease in the tokamak discharge current and thus the increase of the safety factor at the edge, the radial location of the m = 2 magnetic islands has been found to move radially inward.

Acute cannabinoid receptor type 1 (CB1R) modulation influences insulin sensitivity by an effect outside the central nervous system in mice

AIMS/HYPOTHESIS

Modulation of central nervous system (CNS) and extra-CNS cannabinoid receptor type 1 (CB1R) affects metabolic conditions, independently of weight loss. Here we examined the relative contributions of acute CNS and extra-CNS CB1R modulation on insulin sensitivity using pharmacological gain- and loss-of-function of CB1R in mice.

METHODS

We assessed the effects of acute modulation of CB1R on insulin sensitivity and tissue glucose uptake by administering a CB1R agonist (HU210) and antagonist (AM251) (vs vehicle) i.v. in wild-type mice. In addition, we administered a CB1R agonist (vs vehicle) systemically (i.v.) to Cb1r (also known as Cnr1) knockout (Cb1r (-/-)) mice or intracerebroventricularly (i.c.v.) in wild-type mice to elucidate the peripheral vs CNS-mediated regulatory effect of CB1R on insulin sensitivity.

RESULTS

HU210 induced significant insulin resistance in wild-type mice with a reduction of whole-body glucose disappearance rate and muscle Akt phosphorylation, as well as of glucose uptake by skeletal muscle, but not by adipose tissue, changes that were prevented by pretreatment with AM251. HU210 did not affect insulin sensitivity in Cb1r (-/-) mice, suggesting that the observed effects were mediated through CB1R. HU210 administered i.c.v. did not induce insulin resistance, suggesting that acute stimulation of CNS CB1R was not required for this effect.

CONCLUSIONS/INTERPRETATION

Skeletal muscle insulin sensitivity is affected by acute CB1R modulation. These changes are mediated by extra-CNS CB1R, probably by the receptors in skeletal muscle tissue.

Reliable high-throughput approach for screening of engineered constitutive promoters in the yeast Pichia pastoris

AIMS

To develop a reliable and sensitive high-throughput approach for the screening of engineered constitutive promoters in the yeast Pichia pastoris.

METHODS AND RESULTS

The yeast-enhanced green fluorescent protein (yEGFP) was used as the reporter to monitor the promoter strength. After eliminating the interfering components (yeast extract and tryptone) with fluorescence signal from the medium, a high-throughput screening approach was established and optimized to obtain a low standard deviation of cell density (6.9%) and fluorescence (7.4%) in 48-deep-well microplates. Then, 300 clones containing GAP promoter (P(GAP)) variants were screened, exhibiting a wide range in fluorescent intensity from about 8% to 218% of that obtained with P(GAP). Six representative clones with unique promoter sequence were picked for further characterization. A good correlation between yEGFP fluorescence in microplates and shake flasks was observed. Furthermore, the high correlation between fluorescence and transcript levels confirmed that expression was transcriptionally controlled.

CONCLUSIONS

We developed a reliable high-throughput screening approach that can be used to select engineered constitutive promoters of varying strengths.

SIGNIFICANCE AND IMPACT OF THE STUDY

This approach is expected to accelerate the selection of constitutive promoters in P. pastoris and can also be applied for the screening of other constitutive expression clones.

Ultrathin W-Al dual interlayer approach to depositing smooth and adherent nanocrystalline diamond films on stainless steel

The adherence of diamond coated on steel is commonly low and needs to be strengthened with thick intermediate layers. In this paper, a nanoscale W-Al dual metal interlayer has been applied on SS304 substrates to facilitate deposition of continuous, adherent and smooth diamond thin films. During the microwave plasma-enhanced chemical vapor deposition process, the Al inner layer 30 nm thick diffuses into steel surface inhibiting carbon diffusion and graphitization. The W outer layer 20 nm thick is transformed into W carbides, both preventing carbon diffusion and enhancing diamond nucleation. The diamond films synthesized are of high purity and have smooth surfaces and dense structures. Indentation and shear deformation tests indicate high delaminating tolerance of the diamond films.

Genetic distances between Chinese populations calculated on gene frequencies of 38 loci

Genetic distances were calculated for Han subpopulations in different provinces, cities and autonomous regions and ethnic minorities in China by using gene frequency data of 38 loci, and genetic trees were constructed. The results showed that, among both Han and ethnic minorities, there were two types, i.e. southern and northern Mongoloids, with Yangtze River as boundary. Therefore, both African origin theory and local origin theory about the modern man should answer the question: when did these two types separate and how did they develop. This paper also conclusively proved genetically that the Han subpopulations in different regions are genetically close to the local ethnic minorities, which indicates that much blood of ethnic minorities has mixed into Han, at the same time, some blood of Han also has mixed into the local ethnic minorities.

Stability of Estrogen Receptor and HER2 Status Following Trastuzumab and Polychemotherapy Regimen

Background: ER and HER2 status are important to determine a patient's eligibility to receive endocrine therapy and anti-HER2 (trastuzumab) therapy, respectively. However, whether the status of ER and HER2 is stable after administration of trastuzumab and chemotherapy remains controversial. To date, there have been rare studies describing a change of ER and HER2 status following such treatment. We herein examined our experience to further elucidate this issue.Material and methods: Our study included 24 patients who had been diagnosed with breast cancer from 12/1996 to 1/2005 with known ER and HER2 status in both primary and paired relapse tumors (9 distant and 15 locoregional). All of the patients had HER2-positive primary carcinoma and had been treated with trastuzumab administered concomitantly or after polychemotherapy. Fifteen patients had ER-positive primary carcinomas. ER status was defined as positive if ≥10% of tumor cells demonstrated nuclear staining by immunstaining. HER2 status was defined as positive if an immunostaining demonstrated 3+ staining and/or FISH demonstrated a HER2:CEP17 gene copy ratio ≥2.0. The receptor status was tested on tissue sections (for primary tumors) or on FNA samples (for metastases). We evaluated the agreement of ER and HER2 status between primary breast carcinomas and paired metastatic tumors.Results: The time elapsed between the diagnosis of the primary breast carcinoma and sampling of the paired metastatic tumor was &gt;24 months for all patients but one (mean interval, 75 months). Before the metastatic tumors were sampled, the duration of trastuzumab therapy had been ≥12 month in 18 patients; in some patients the treatment had been intermittent. All 15 patients with ER-positive primary carcinoma had received adjuvant endocrine therapy, including tamoxifen, aromatase inhibitor or both, and 7 of them had completed 5 years of treatment. ER status of primary and metastatic tumors agreed in 20 of the 24 patients, with a concordance rate of 83.3% (95% CI, 68.42% - 98.24%), and Cohen's kappa coefficient of 0.6596 (95% CI, 0.3598 - 0.9593). Of the four patients with discordant ER status, three had ER-positive primary tumors but ER-negative metastatic tumors, and one had ER-negative primary tumor but ER-positive metastatic tumor. Notably, in two of the four patients, the percentage of ER-positive tumor cells in the primary carcinomas was close to the cutoff (10%), indicating the potential of scoring difficulty. Negative HER2 status was found in three (12.5%) of the 24 metastatic tumors. One of the three patients had two primary carcinoma nodules: one HER2-positive and the other HER2 negative. It is possible that negative HER2 status in the metastatic tumor may result from a metastasis from the HER2-negative primary tumor, rather than a true discrepancy.Conclusions: Change in ER status was found in 17% relapse tumors, mostly from positive to negative. Converting HER2 status from positive to negative was seen in 13% patients. Overall, trastuzumab and chemotherapy do not significantly alter ER and HER2 status. However, a larger study is required to confirm whether the discordant receptor status is due to true biologic shift or other factors (i.e., technical and interpretation variation).

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5097.

Specific and sensitive detection of Ralstonia solanacearum in soil with quantitative, real-time PCR assays

AIMS

The aim of this study was to develop a sensitive and an effective method suitable for large-scale detection and quantification of Ralstonia solanacearum in soil.

METHODS AND RESULTS

Based on the specific sequence of R. solanacearum strain G1000, the primer pair R.sol1-R.sol2 and the TaqMan probe Rs-pro were designed, and specific and sensitive PCR detection methods were successfully established. The detection limit was 100 fg microl(-1) DNA in conventional PCR and 1.2 fg microl(-1) in real-time PCR. By combining real-time PCR with the modified protocols to extract DNA from soil, it was possible to achieve real-time detection of R. solanacearum in soil, and the degree of sensitivity was 100 fg microl(-1). To detect inhibition in soil samples, an exogenous internal positive control (IPC) was included preventing false negative results, and IPC was successfully amplified from all samples tested. The methodology developed was used to detect the presence of R. solanacearum in tobacco fields in China.

CONCLUSIONS

The real-time PCR combined with the protocol to extract DNA from soil led to the development of a specific, sensitive and rapid detection method for R. solanacearum in soil.

SIGNIFICANCE AND IMPACT OF THE STUDY

The real-time PCR improves the detection sensitivity and specificity and provides an important tool for routine detection of R. solanacearum in soil samples and for epidemiological and ecological studies.

Retarding field energy analyzer for the Saskatchewan Torus-Modified plasma boundary

The retarding field energy analyzer (RFA) is a simple and reliable diagnostic technique to measure the ion temperature in the scrape-off layer and edge of magnetic fusion devices. Design and operation features of a single-sided (facing the ion flow) RFA for ion temperature measurements in the Saskatchewan Torus-Modified (STOR-M) tokamak are described. Its compact size (21 x 15 x 20 mm3) allows RFA measurements without perturbing plasma significantly. Both ion and electron temperature have been measured by RFA in the STOR-M tokamak. A method is proposed to correct the effects of ion flow on the ion temperature using the simultaneously measured Mach number. The measured electron temperature is consistent with the previously reported Langmuir probe data. Abnormal behavior of the RFA has been observed in both ion and electron modes when RFA is inserted deep into the plasma.

Anti‐inflammatory and anti‐oxidative effects of cherries on Freund's adjuvant‐induced arthritis in rats

OBJECTIVES

To investigate the anti-inflammatory and anti-oxidative effects of anthocyanins from cherries on Freund's adjuvant-induced arthritis (AIA) in rats.

METHODS

Arthritis was induced intradermally by injection with 0.1 mL of complete Freund's adjuvant (CFA) into the right hind footpad of male Sprague Dawley (SD) rats. Anthocyanins at 40, 20 and 10 mg/kg (body weight) were administered orally to the treated rats for 28 days after the injection. Tumour necrosis factor-alpha (TNFalpha) in serum and prostaglandin E2 (PGE2) in paws were assayed by radioimmunoassay (RIA), and anti-oxidative effects was assayed by measuring total anti-oxidative capacity (T-AOC), superoxide dismutase (SOD) and malondialdehyde (MDA) in serum.

RESULTS

Anthocyanins at 40 mg/kg significantly decreased the levels of TNFalpha in serum and PGE2 in paws, simultaneously improving the anti-oxidative status of AIA. We found that at this dosage T-AOC was potentized, the activity of SOD increased and the level of MDA in serum decreased. However, anthocyanins at 20 and 10 mg/kg had less effect on the inflammatory factors and anti-oxidative capacity of AIA.

CONCLUSIONS

Anthocyanins have potential anti-inflammatory and anti-oxidative effects on AIA.

The pathologic features of neurocutaneous melanosis in a cynomolgus macaque

Neurocutaneous melanosis (NCM) is a rare phakomatosis characterized by proliferation of melanin-producing cells in both the skin and the brain. In this study, we describe the clinical and pathologic features of NCM in a 4.5-year-old female cynomolgus macaque. Histopathologically, skin lesions showed foci of nests and cords of pigmented cells in the dermis similar to blue nevi in humans. In the brain, focal pigmented cell infiltration was observed in the connective tissue under the leptomeninges and in the brain parenchyma. The pigmented cell was moderately reactive with a pan-melanoma antibody (melanoma(pan)) in the skin. In the brain, the pigmented cell was moderately to strongly positive for melanoma(pan) in subleptomeningeal areas and in the cerebral cortex. Melanosomes were observed in pigmented cells in the brain by electron microscopic examination. Based on the histologic, immunohistochemical, and electron microscopic results, the diagnosis of NCM was made. This case is possibly the first report of the condition in animals.

Glial glucocorticoid receptors in aged Fisher 344 (F344) and F344/Brown Norway rats

Glucocorticoid receptors (GR) regulate glial function, and changes in astrocyte gene expression are implicated in age-related pathology. We evaluated changes in astroglial GR expression in two strains of rats--Fisher 344 (F344; 4, 12 and 24 months) and F344/Brown Norway strain (F344/BN; 4, 12 and 30 months). In both strains basal levels of corticosterone were higher in the oldest groups of rats. Age-related increases in GR (+) astrocytes but not the percent of astrocytes expressing GR were observed in the hippocampus CA1 region in F344 rats. Age-related decreases in CA1 GR (+) astrocytes and the percentage of GR (+) astrocytes were observed in the F344/BN strain only. Similar strain-specific changes were observed in the dentate gyrus. In the hypothalamic paraventricular nucleus: (1) F344 rats exhibited significant decreases in the overall number of glial profiles with age, (2) F344/BN rats exhibited decreases in the numbers of GR (+) astrocytes with aging and (3) the proportion of GR (+) astrocytes decreased in older F344/BN, but not F344 rats. Overall, the data demonstrate age- and strain-related alterations in GR astrocytic expression that may explain unique phenotypic differences in brain function observed in both strains.

Acute dipeptidyl peptidase-4 inhibition rapidly enhances insulin-mediated suppression of endogenous glucose production in mice

Pharmacological approaches that enhance incretin action for the treatment of type 2 diabetes mellitus have recently been developed, i.e. injectable glucagon-like peptide-1 receptor (GLP-1R) agonists with prolonged plasma half-lives and orally available inhibitors of dipeptidyl peptidase (DPP)-4, the main enzyme responsible for the rapid degradation of circulating glucagon-like peptide-1 and glucose-dependent insulinotropic peptide. The mechanism(s) underlying the glucose-lowering effect of these two pharmacotherapies differs and is not yet fully understood. Here we investigated whether acute GLP-1R activation (exendin-4) or DPP-4 inhibition (des-F-sitagliptin) modulates insulin action in mice using a hyperinsulinemic euglycemic clamp. A single iv bolus of des-F-sitagliptin (11 mg/kg) was administered to mice 15 min after the start of the clamp, and its effect was compared with a 50-ng bolus of exendin-4 or the same volume of saline. Despite matched levels of plasma glucose and insulin, within 15 min the glucose infusion rate required to maintain euglycemia was significantly greater after des-F-sitagliptin compared with saline or exendin-4. This difference was entirely due to enhancement of insulin-mediated suppression of endogenous glucose production by des-F-sitagliptin, with no difference in glucose disposal rate. These findings illustrate that DPP-4 inhibition modulates glucose homeostasis through pathways distinct from those used by GLP-1R agonists in mice.

An automatic photometric method with high precision by gradually diluting a sample

An automatic photometric method to increase the precision of measurement is proposed, which is based on the injection of a very small volume of sample by rotary valve and the subsequent homogeneous mixing in a small reaction cell made of glass of the sample with a color-developing reagent gradually delivered by a syringe piston pump until the absorbance of the mixture approaches 0.434, where the lowest relative error in the concentration locates. This photometric method is characteristic of uniformly high precision, low sample and reagent consumption, and high sampling rate of 30 samples per h. The other advantages of this method include easy calibration with only one standard solution and no strict requirements on photometric components. While applied for the determination of cobalt ranging from 0.21 to 1.43 g 1(-1), the relative standard deviations are all below 0.4%.

Design and initial operation of multichord soft x-ray detection arrays on the STOR-M tokamak

Two miniature pinhole camera arrays for spatially and temporally resolved measurements of soft x-ray emission have been designed and installed on the STOR-M tokamak. Each array consists of a photodiode array, with one array viewing vertically and one viewing horizontally through a plasma cross section. Preamplifiers with fixed gains of 10(5) VA and custom built amplifiers with variable gains are used for signal amplification. Digitizers with 14 bit resolution and 3 MSs sampling rate are used for data acquisition. In the initial operation, an Al foil with a thickness of 1.8 microm installed for one array and Be filter of 7.6 microm installed for the other array are used to test signal strength. Initial tests have identified sawtooth oscillations and 20 kHz fluctuations, which are also detected by Mirnov coils, superimposed on the sawtooth oscillations.

Polymorphism of HLA-DRB1, -DQB1 and -DPB1 genes in Bai ethnic group in southwestern China

In this work, polymorphism of human leukocyte antigen (HLA)-DRB1, -DQB1 and -DPB1 genes was detected using polymerase chain reaction-sequence-based typing method in 128 healthy unrelated volunteers from the Bai ethnic group of Yunnan province of southwest China. Among all the 28 alleles detected for the DRB1 gene, the most common allele was DRB1*120201 with a frequency of 16.41%, followed by DRB1*090102, DRB1*080302, DRB1*1404, DRB1*150101, DRB1*140101 and DRB1*160201, with frequencies of 10.16%, 9.77%, 9.38%, 8.98%, 8.59% and 8.21%, respectively. Among 19 DQB1 alleles detected, the most frequent allele was DQB1*030101/0309 (35.94%), followed by DQB1*050201 (11.33%), DQB1*060101/060103 (10.54%) and DQB1*0401 (10.16%). For the DPB1 locus, the most common alleles were DPB1*0501 (42.19%), DPB1*1301 (13.28%), DPB1*020102 (10.93%) and DPB1*040101 (9.77%). The comparison of HLA class II allele frequencies of Bais with those of other Chinese populations suggested that the Bai ethnic group belonged to the southern group of Chinese.

Oral taurine but not N-acetylcysteine ameliorates NEFA-induced impairment in insulin sensitivity and beta cell function in obese and overweight, non-diabetic men

AIMS/HYPOTHESIS

Antioxidants have been shown to ameliorate lipid-induced impairment of insulin action and beta cell function, both in vitro and in animal studies. The aim of the present study was to examine the effects of two orally administered antioxidants, N-acetylcysteine (NAC) and taurine (TAU), on lipotoxicity in humans.

METHODS

Nine non-diabetic men, who were either overweight or obese, underwent three studies each, 4-6 weeks apart, in random order: (1) i.v. infusion of saline for 48 h (SAL); (2) i.v. infusion of Intralipid and heparin for 48 h to mimic chronic elevation of plasma NEFA (IH); and (3) IH infusion for 48 h with concurrent oral NAC (IH+NAC). Six men underwent similar studies except for study 3, where instead of NAC they received a 2 week pretreatment with oral TAU (IH+TAU).

RESULTS

For both the NAC and TAU studies, a 48 h IH infusion alone without antioxidant impaired insulin sensitivity (S(I), 63% and 62% of SAL in NAC and TAU studies, respectively) and beta cell function, as evidenced by a reduction in disposition index (DI, 55% and 54% of SAL in NAC and TAU studies, respectively). NAC failed to prevent the lipid-induced increase in levels of the plasma oxidative stress marker malondialdehyde and did not prevent the lipid-induced reduction in S(I) or DI, whereas TAU completely prevented the rise in malondialdehyde and decreased 4-hydroxynonenal, and significantly improved S(I) (91% of SAL) and DI (81% of SAL).

CONCLUSIONS/INTERPRETATION

Oral TAU ameliorates lipid-induced functional beta cell decompensation and insulin resistance in humans, possibly by reducing oxidative stress.

Performance of the university of saskatchewan compact torus injector with curved acceleration electrodes

The first vertical compact torus (CT) injection experiment has been performed in the Saskatchewan Torus Modified (STOR-M) tokamak [Nucl. Fusion 46, 104 (2006)]. To increase the kinetic energy density of the injected CTs for deeper penetration, the University of Saskatchewan Compact Torus Injector (USCTI) was further modified by attaching a 90 degrees curved inner electrode coaxial with the outer electrode. The modification extended the original CT acceleration section from 60 to 114 cm. Effects of the curved acceleration electrodes on the velocity and magnetic field of the CT are reported in this paper. It has been found that the CTs, injected horizontally, were deflected to vertical direction and CT velocity measured at the curved acceleration section increased to 180 kms, representing a 40% increase compared with the case without the curved inner electrode in a previous experiment. At a higher acceleration bank voltage of 16 kV, this velocity increased to about 270 kms. In addition, amplification of the CT magnetic field in the curved acceleration section has also been observed.