T7 phage displaying latent membrane protein 1 of Epstein-Barr virus elicits humoral and cellular immune responses in rats

The latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus (EBV) has become a potential target in EBV-associated tumor prevention and treatment due to its multiple biological effects. In this study, the recombinant T7 phage displaying full-length LMP1 protein was cloned and used as an immunogen to immunize rats. Results of flow cytometry, Western blot analysis, and ELISA confirmed that both humoral and cellular immune responses were elicited in the immunized rats. Our data suggested that T7 phage was an efficient antigen carrier. The recombinant T7-LMP1 phage reconstitutes the antigenic and immunogenic properties of LMP1 and can serve as a vaccine against EBV.

Structural and biophysical properties of a synthetic channel-forming peptide: designing a clinically relevant anion selective pore

The design, synthesis, modeling and in vitro testing of channel-forming peptides derived from the cys-loop superfamily of ligand-gated ion channels are part of an ongoing research focus. Over 300 different sequences have been prepared based on the M2 transmembrane segment of the spinal cord glycine receptor α-subunit. A number of these sequences are water-soluble monomers that readily insert into biological membranes where they undergo supramolecular assembly, yielding channels with a range of selectivities and conductances. Selection of a sequence for further modifications to yield an optimal lead compound came down to a few key biophysical properties: low solution concentrations that yield channel activity, greater ensemble conductance, and enhanced ion selectivity. The sequence NK(4)-M2GlyR T19R, S22W (KKKKPARVGLGITTVLTMRTQW) addressed these criteria. The structure of this peptide has been analyzed by solution NMR as a monomer in detergent micelles, simulated as five-helix bundles in a membrane environment, modified by cysteine-scanning and studied for insertion efficiency in liposomes of selected lipid compositions. Taken together, these results define the structural and key biophysical properties of this sequence in a membrane. This model provides an initial scaffold from which rational substitutions can be proposed and tested to modulate anion selectivity. This article is part of a Special Issue entitled: Protein Folding in Membranes.

First Report of Leaf Spot Disease on Dictamnus dasycarpus Caused by Phoma dictamnicola in China

Fraxinella, Dictamnus dasycarpus Turcz (Rutaceae), is a perennial herbal plant and mainly distributed in Eurasia and North America. It is often used to treat jaundice, cough, rheumatism, and other diseases and is extensively cultivated in the northeast and northwest of China (3). In June 2009, a severe foliar disease was observed on D. dasycarpus in medicinal plantations in Antu, China. The disease occurred on 100% of the plants and at least 25% of the surface was affected. In the early stages of disease development, symptoms were visible on the top and bottom of infected leaves as small brown spots. Subsequently, these spots became elliptical to irregularly shaped, with beige or grayish white centers and dark brown margins. Within the spots, numerous, dark brown or black, subglobose or ostiolate pycnidia measuring 152 to 367 μm in diameter were observed. Fungal isolates were obtained from the infected leaves on potato dextrose agar (PDA) medium, with conidia that were aseptate or one-septate and ellipsoidal or reniform, measuring approximately 4.7 to 12.6 × 2.1 to 4.5 μm. On the basis of these characteristics, the fungus was identified as a Phoma sp. Four well-sporulating isolates, designated as DdPh-1, DdPh-2, DdPh-3, and DdPh-4, were selected for further studies. The morphological and cultural characteristics of these four isolates were studied as described by Boerema et al. and the fungus was identified as Phoma dictamnicola Boerema et al. (1). The internal transcribed spacer (ITS) region of the nuclear rDNA was amplified and sequenced using primers ITS4/ITS5 (2). All four of the ITS sequences were identical (GenBank Accession No. FR681861) and were 99% identical to P. dictamnicola strains CBS507.91 (Accession No. GU237877) and KACC42445 (Accession No. EF600960). Pathogenicity tests were performed by spraying the leaves of healthy D. dasycarpus plants with a conidial suspension (1 × 10⁶ conidia/ml). Five plants were inoculated with each isolate (DdPh-1, DdPh-2, DdPh-3, and DdPh-4) and five plants were mock inoculated with sterile water. The plants were covered with plastic bags and kept in a greenhouse at 20 to 25° for 72 h. After 9 to 13 days, all inoculated plants showed characteristic symptoms as previously described, while the control plants remained healthy. The fungus was reisolated from the leaf spots of inoculated plants. Currently, the economic importance of this disease is limited, but it may become a more significant problem in production of D. dasycarpus with the cultivation area increasing. The fungus was found in the Netherlands and Korea, but to our knowledge, this is the first report of P. dictamnicola on D. dasycarpus in China. References: (1) G. H. Boerema et al. Phoma Identificatión Manual: Differentiation of Specific and Infra-Specific Taxa in Culture. CABI Publishing. Wallingford, U.K., 2004. (2) D. E. L. Cooke et al. Mycol. Res. 101:667, 1997. (3) S. S. Jiang et al. Biosci. Biotechnol. Biochem. 72:660, 2008.

Diagnostic accuracy of features predicting lower gastrointestinal malignancy: a colonoscopy database review of 10,603 Chinese patients

AIM

The diagnostic accuracy of colonoscopic features in predicting colorectal cancer (CRC) malignancy was studied.

METHOD

Consecutive patients who underwent first-time colonoscopy for lower gastrointestinal (GI) symptoms from 1998 to 2009 were identified. Gender, age, symptoms, endoscopic and pathologic findings were reviewed.

RESULTS

There were 10,603 patients. The overall prevalence of malignancy was 3.0% (313). Among these, only 58% (181/313) had features indicative of tumour formation. The overall sensitivity and specificity was 9.6% and 94.1%, respectively. The overall positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were 2.66, 0.96 and 2.77, respectively.

CONCLUSION

A large proportion of Chinese patients with CRC presented without features indicative of tumour formation.

First Report of Botrytis Leaf Blight and Fruit Rot on Schisandra chinensis Caused by Botrytis cinerea in China

Schisandra (Schisandra chinensis (Turcz.) Baill) is a perennial plant belonging to Magnoliaceae. It is a very important medicinal herb in China and is mainly used for treatment of insomnia and memory decay. From July to September 2008, an unknown leaf blight and fruit rot on schisandra were first observed at Jingyu County, Jilin Province. The same symptoms were detected in other areas of Jilin Province, such as Ji'an City, Baishan City, and Hunchun City. Initially, some small, brown spots appeared on the tip or margin of the leaves. Light brown or brown necrotic lesions developed and eventually covered entire leaves. Seriously affected leaves were rolled or distorted and eventually became completely dry and brittle. Small spots appeared on the surface of mature fruits, coalesced, and the fruits finally dropped. Gray mycelia and conidiophores developed on the diseased leaves and fruits. To isolate the causal agent, conidia and conidiophores were scraped aseptically from the internal tissues, suspended in sterile water, and streaked onto the surface of potato dextrose agar (PDA). Single-hyphal tips were transferred on PDA and the isolated fungus was identified as Botrytis cinerea Pers.: Fr. on the basis of its morphological characteristics and internal transcribed spacer (ITS) sequence. Colonies of B. cinerea on PDA were colorless at first and became gray to brown 20 days later with the mycelium growth and conidia producing in cultures. Conidia are single celled, lemon shaped, colorless to a light color, and 4.4 to 15.0 × 7.0 to 10.0 μm. Sclerotia formed about 1 week later, were black-brown and varied in size (2.0 to 5.0 × 2.0 to 4.0 mm) and shape. The ITS region of rDNA was amplified from DNA extracted from single-spore isolate BC12 of B. cinerea using primers ITS4/ITS5 and sequenced (GenBank Accession No. GU724512), BLAST analysis (1) of the 535-bp segment showed 99% similarity with the sequence of Botryotinia fuckeliana (perfect stage of B. cinerea). Pathogenicity tests were carried out on healthy schisandra plants that were 4 years old. After the surface of the leaves and fruits was disinfected with 5% sodium hypochlorite, a conidial suspension of 10⁵ conidia/ml was sprayed on 10 schisandra leaves, and plugs of the fungus obtained from the colony margins were transferred onto a 3- × 3-mm wound on the surface of disinfected fruit. Ten control schisandra leaves and 10 fruits were inoculated at the same time. Plants were covered with polyethylene bags and incubated at 25°C in a greenhouse with relative humidity of 85% for 3 days. Similar symptoms to those observed on diseased leaves and fruits in the field were observed on inoculated schisandra leaves and fruits 7 days after inoculation, whereas control leaves and fruits showed no symptoms. The pathogen was successfully reisolated. The gray mold disease caused by B. cinerea was reported in many plants, such as Lavandula stoechas and Chamelaucium uncinatum in Italy (2,3). However, to our knowledge, this is the first report of gray mold disease of schisandra caused by B. cinerea in China. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) A. Garibaldi et al. Plant Dis. 94:968, 2009. (3) A. Garibaldi et al. Plant Dis. 94:380, 2010.

UV light emitting transparent conducting tin-doped indium oxide (ITO) nanowires

Multifunctional single crystalline tin-doped indium oxide (ITO) nanowires with tuned Sn doping levels are synthesized via a vapor transport method. The Sn concentration in the nanowires can reach 6.4 at.% at a synthesis temperature of 840 °C, significantly exceeding the Sn solubility in ITO bulks grown at comparable temperatures, which we attribute to the unique feature of the vapor-liquid-solid growth. As a promising transparent conducting oxide nanomaterial, layers of these ITO nanowires exhibit a sheet resistance as low as 6.4 Ω/[Symbol: see text] and measurements on individual nanowires give a resistivity of 2.4 × 10(-4) Ω cm with an electron density up to 2.6 × 10(20) cm(-3), while the optical transmittance in the visible regime can reach ∼ 80%. Under the ultraviolet excitation the ITO nanowire samples emit blue light, which can be ascribed to transitions related to defect levels. Furthermore, a room temperature ultraviolet light emission is observed in these ITO nanowires for the first time, and the exciton-related radiative process is identified by using temperature-dependent photoluminescence measurements.

Effects of purified zearalenone on growth performance, organ size, serum metabolites, and oxidative stress in postweaning gilts

Zearalenone (ZEA), an estrogenic mycotoxin, is produced mainly by Fusarium fungi. Previous studies indicated that acute ZEA exposure induced oxidative stress and damage in multiple organs. Therefore, the present study was designed to investigate the adverse effects of dietary ZEA (1.1 to 3.2 mg/kg of diet) on oxidative stress and organ damage in postweaning gilts. A total of 20 gilts (Landrace × Yorkshire × Duroc) weaned at d 21 with an average BW of 10.36 ± 1.21 kg was used in the study. Gilts were housed in a temperature-controlled room, divided into 4 treatments, and fed a basal diet only (control) or basal diet supplemented with purified ZEA at a dietary concentration of 1 (ZEA1), 2 (ZEA2), or 3 (ZEA3) mg/kg of diet for 18 d ad libitum. The actual ZEA contents (analyzed) were 0, 1.1 ± 0.02, 2.0 ± 0.01, and 3.2 ± 0.02 mg/kg for control, ZEA1, ZEA2, and ZEA3, respectively. Gilts fed different amounts of dietary ZEA grew similarly with no difference (P > 0.05) in feed intake. Vulva size increased linearly over the 18 d of feeding in gilts fed diets containing 1.1 mg of ZEA/kg or greater (P < 0.001). Relative weight of genital organs, liver, and kidney increased linearly (P < 0.05) in a ZEA-dose-dependent manner. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, γ-glutamate transferase, urea, and creatinine (P < 0.05), and malondialdehyde concentrations in both serum and liver (P < 0.001) were also increased linearly in a ZEA-dose-dependent manner. However, spleen relative weight (P = 0.002) and activities of total superoxide dismutase and glutathione peroxidase (in both serum and liver (P < 0.05) were decreased linearly as dietary ZEA increased. Results showed that besides genital organs, the liver, kidney, and spleen may also be target tissues in young gilts fed diets containing 1.1 to 3.2 mg of ZEA/kg for 18 d. Increased key liver enzymes in the serum suggest progressive liver damage caused by feeding ZEA, and an increase in oxidative stress in gilts is another potential impact of ZEA toxicity in pigs.

First Report of Alternaria Leaf Spot on Eleutherococcus senticosus Caused by Alternaria tenuissima in China

Eleutherococcus senticosus (Ruper et Maxim) Maxim, a very important potential medicinal plant used for the treatments of neurasthenia, anti-aging, and kidney deficiency, is a perennial herb belonging to Araliaceae and mainly distributed in northeast China. With the development of its cultivation, many diseases start to occur and a previously unknown leaf spot was observed on this plant in July 2007 in Linjiang City, Jilin Province, China. This disease incidence reached 100% in some planting grounds and it has resulted in serious loss of acanthopanax production. This disease generally happens during July and August in Jilin Province, China. At the initial stage of the infection, some small, light brown spots appeared on the leaves that gradually become round or irregular, dark brown, concentrically zonate with a dark brown margin, frequently surrounded by light yellow haloes and conspicuous black brown concentric rings in the advanced stage of the infection. The necrotic areas often coalesce and result in the appearance of larger spots with a diameter of 13.0 to 15.0 mm. Severely affected plants were defoliated. On leaf spots, conidia, generally in short chains, were straight, multicellular, obclavate or obpyriform, olivaceous brown or dark brown, with three to eight transverse and rarely zero to four longitudinal or zero to three oblique septa, and measured 8.3 to 27.5 × 17.3 to 55.0 μm. Conidiophores arose singly or in groups, straight or flexuous, cylindrical, expand in base cell, branch occasionally, septate, pale to olivaceous brown, 25.0 to 75.0 μm long, 3.0 to 6.0 μm wide; beak or false beak cylindrical, septate, colorless or light brown, and measured 2.0 to 5.1 × 10.4 to 47.7 μm. The morphological descriptions and measurements of the fungi are similar to Alternaria tenuissima (2). Six single cultures from the infected leaves were isolated on potato dextrose agar. Pathogenicity tests were carried out on the potted, healthy, 1-year-old plants (n = 10). These plants were divided into two groups, one group was sprayed with a conidial suspension of 10⁵ conidia per ml and the other was sprayed with sterilized water as control plants. All plants were covered with polyethylene bags for 3 days. Symptoms of the disease appeared 5 days after inoculation. Symptoms on the inoculated leaves were similar to those that naturally occurred on the plants. The fungal pathogen was consistently reisolated from the inoculated plants but not from the control plants. The internal transcribed spacer (ITS) region of rDNA was amplified from DNA extracted from single-spore isolate cwz-2 of the pathogen using the ITS1/ITS4 and sequenced (GenBank Accession No. HQ402558). The ITS sequence had 99% identity with that of A. tenuissima strain XSD-83 (GenBank Accession No. EU326185). Therefore, the pathogen was identified as A. tenuissima on the basis of its morphological characteristics and ITS sequence. A. tenuissima was reported to occur on many plants such as blueberry in China (1). However, to our knowledge, this is the first report of A. tenuissima occurring on E. senticosus in China. References: (1) Y. S. Luan et al. Plant Dis. 91:464, 2007. (2) T. Y. Zhang et al. Fungi Notes-Genera Alternaria in China, 16:19, 38, 2003.

Immunoexpression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in the metastasis of squamous cell carcinoma of the human tongue

BACKGROUND

Squamous cell carcinoma of the tongue has frequent lymph node metastases and poor prognosis. Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) are reported to degrade basement membrane,facilitating invasion and metastasis. This study determined the expression of MMP-2/MMP-9 in primary tongue cancer with or without cervical metastases and analysed the significance of such expression in relation to the presence or absence of metastases.

METHODS

Expressions of MMP-2⁄MMP-9 were detected by immunohistochemistry in 10 specimens of normal oral mucosa, 20 lymph node-negative tongue cancers, 41 lymph node-positive tongue cancers and their metastasized tumours in cervical lymph nodes.

RESULTS

MMP-2⁄MMP-9 expression was seldom found in normal epithelium. In lymph node-negative tongue cancer, 45% and 40% of these primary tumours were positively stained for MMP-2⁄MMP-9, respectively. Importantly, in lymph node-positive tongue cancer, 71% and 79% of these primary tumours were positive for MMP-2⁄MMP-9, respectively. Overexpression of MMP-2⁄MMP-9 was present in the metastatic lymph nodes.

CONCLUSIONS

Our results imply that MMP-2 and/or MMP-9 play an important role in invasion and metastasis in tongue cancer, and that analysis of MMP expression and/or activity in primary tumours may have a predictive value for the actual or potential presence of cervical metastases.

Involvement of mitogen-activated protein kinase activation in cyclooxygenase-2 and transforming growth factor-β production in alveolar macrophage from chronic bronchitis rats

OBJECTIVE

Lipopolysaccharides (LPS) activates several signaling pathways in macrophages including mitogen-activated protein kinases (MAPK). Previous studies have investigated effect of LPS on MAPK activation in macrophage of normal rats. In the current study, we investigated the effect of LPS exposure on activation of MAPK in alveolar macrophage (AM) of chronic bronchitis (CB) rats and researched the corresponding cyclooxygenase-2 (COX-2), prostaglandins-2 (PGE(2)) and transforming growth factor- β (TGF-β) production and their MAPK signal pathways.

METHODS

CB model was established by injection of Bacillus Calmette-Guerin (BCG) and LPS in rats. Special inhibitors of p38, extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinases (JNK) MAPK signal pathways were used to determine the effect of MAPK activation on COX-2, PGE(2), TGF-β production in AM of CB rats via RT-PCR, western blotting, radioimmunoassay and ELISA.

KEY FINDINGS

Synthesis of PGE(2) from AM of CB rats was increased and suppressed by either PD98059 or SB203580. SB203580 and PD98059, (inhibitors of ERK and p38 MAPK), could significantly inhibit COX-2 mRNA and protein expression. Moreover, ERK and p38 MAPK had synergistic effect on COX-2 expression. Inhibitor of ERK MAPK signal transduction could inhibit TGF-β expression in AM.

CONCLUSION

These results demonstrated COX-2, PGE(2) and TGF-β productions in AM of CB rats were significantly increased, which might be regulated by the different MAPK signaling pathway.

LECs Made of m-Lppp

We report the application of the blue light emitting conjugated polymer m-LPPP (methyl substituted laddertype poly(paraphenylene) ) in light emitting electrochemical cells. The active layer of the LEC consists of a blend of m-LPPP with the ionically conductive polymer PEO and LiCF3SO3 as ionic salt. Investigations of different concentrations of PEO and salt showed that the best LECs made of m-LPPP up to now where realised with an active layer consisting of a blend of m-LPPP:PEO:salt in the range of 20:10:3. In this case we are able to realise LECs with response times in the range of 30 μs. The I/U characteristics show low turn on voltages both for current and electroluminescence, but only in the case of ITO biased as a cathode. The initial electroluminescence spectra are quite the same as those for LEDs made of m-LPPP but turn into green after some time of operation.

A meta-analysis of the relation of polymorphism at sites -1082 and -592 of the IL-10 gene promoter with susceptibility and clearance to persistent hepatitis B virus infection in the Chinese population

BACKGROUND

Up to now, many publications about the Chinese population have evaluated the correlation between interleukin-10 (IL-10) -1082 and -592 polymorphisms and persistent hepatitis B virus (HBV) infection. However, the results remain inconclusive. In order to resolve this conflict, a meta-analysis was performed.

METHODS

Seven studies were included and dichotomous data are presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

The results of our study suggest that carriers of the IL-10 -592A allele were more likely to clear HBV spontaneously in the Chinese pooled population (A vs. C: OR = 0.799, 95% CI = 0.678-0.941, P = 0.007; AC vs. AA: OR = 1.343, 95% CI = 1.017-1.684, P = 0.011; AA vs. AC + CC: OR = 0.736, 95% CI = 0.594-0.912; AA + AC vs. CC: OR = 0.588, 95% CI = 0.408-0.848, P = 0.004) and the IL-10 -1082A allele was associated with significantly reduced persistent HBV infection risk in Chinese (A vs. G: OR = 0.701, 95% CI = 0.494-0.996, P = 0.047; AA vs. GG + GA: OR = 0.684, 95% CI = 0.476-0.982, P = 0.040).

CONCLUSIONS

Persistent HBV infection susceptibility is associated with the gene polymorphism IL-10 -1082GA in the Chinese population and the clearance of HBV is associated with the gene polymorphism IL-10 -592CA in the Chinese population.