A simple and novel method for GII norovirus genome clone with generic primers

AIMS

This study aims to establish a novel method for cloning GII norovirus genome using generic primers rationally designed based on multiple alignments of 96 GII norovirus genome sequences.

METHODS AND RESULTS

Based on conservative analysis of 96 GII norovirus genome sequences available in GenBank, three fragments encompassing the full-length genome were rationally designed. Fragments A, B and C were amplified by primers N1F/N2819R, N2689F/COG2R and COG2F/adaptor, respectively. Meanwhile, the sensitivity of the novel primers was evaluated, which could achieve 10(1) RTPCRU, as determined by the common detection primer pair JV12/JV13. The availability of the novel protocol was verified by sequencing two norovirus strains with different genotypes.

CONCLUSIONS

Primers for GII norovirus genome clone were rationally designed, and a novel GII genome clone method was established.

SIGNIFICANCE AND IMPACT OF THE STUDY

The three-fragment cloning method can be used as a universal tool to collect information on the genome of norovirus strains for future evolution and antivirus studies.

Excimers He2* as tracers of quantum turbulence in 4He in the t = 0 limit

We have studied the interaction of metastable 4He2* excimer molecules with quantized vortices in superfluid 4He in the zero temperature limit. The vortices were generated by either rotation or ion injection. The trapping diameter of the molecules on quantized vortices was found to be 96±6  nm at a pressure of 0.1 bar and 27±5  nm at 5.0 bar. We have also demonstrated that a moving tangle of vortices can carry the molecules through the superfluid helium.

Aldo-keto reductase 1C3 may be a new radioresistance marker in non-small-cell lung cancer

Human aldo-keto reductase 1C3, type 2 3α-hydroxysteroid dehydrogenase (HSD)/type 5 17β-HSD (AKR1C3) is known to be involved in steroid, prostaglandin and lipid aldehyde metabolism. The role of AKR1C3 in the radiosensitivity to X-rays of human non-small-cell lung cancer (NSCLC) cells was explored. In this study, a specific small interfering RNA (siRNA) to target the AKR1C3 gene was used. A suite of readouts including cell survival were determined using a colony formation assay; apoptosis evaluated by Annexin V expression levels, irradiation-induced cytotoxicity established using a MTT cell viability assay and cell cycle distribution measured by flow cytometry were used in characterizing the role of the AKR1C3 gene. Although AKR1C3 was significantly overexpressed in both our radioresistant subclone cells and NSCLC tissues, a specific AKR1C3 siRNA significantly enhanced cell radiosensitivity and was concomitant with decreased expression of this gene. Furthermore, reduced interleukin-6 (IL-6)-mediated radioresistance was observed when siRNA was used to knock down AKR1C3 activity. This AKR1C3-mediated radioresistance was correlated with an arrest in the G2/M cell cycle and a decreased induction of apoptosis. AKR1C3 may present a potential therapeutic target in addressing radioresistance of NSCLC, and in particular in IL-6-mediated radioresistance.

The predicting study for chromatographic retention index of saturated alcohols by MLR and ANN

A QSRR method was followed to relate the observed Kovats retention indexes of saturated alcohol compounds with their molecular connectivity indices by means of multilinear regression analysis and artificial neural networks technique. The alcohols included linear, branched with hydroxyl group on a primary, secondary, or tertiary carbon atom. At first, models were generated for six OV (Ohio Valley) series columns separately, with high value of R and F statistics. Then a combined model, added a polarity term of stationary phase (M), was also developed for all these columns, and the result was satisfactory. For comparison, the neural network of BP algorithm was applied, and it was found that the neural network could exceed the level of the multiple regression method. The stability and validity of both models were tested by cross-validation technique and by prediction response values for the prediction set.

Effects of Food-simulating Liquids on Surface Properties of Giomer Restoratives

This study examined the effects of food-simulating liquid (FSL) on the hardness and roughness of giomer restoratives based on pre-reacted glass ionomer (PRG) technology. The materials investigated included a regular (Beautifil II [BT]) and a recently introduced injectable (Beautifil Flow Plus F00 [BF]) hybrid PRG composite. A direct hybrid composite (Filtek Z250 [ZT]) and an indirect hybrid composite (Ceramage [CM]) were used for comparison. The materials were placed into customized square molds (5 mm × 5 mm × 2.5 mm), covered with Mylar strips, and cured according to manufacturers' instructions. The materials were then conditioned in air (control), distilled water, 50% ethanol solution, and 0.02 N citric acid at 37°C for seven days. Specimens (n=6) were then subjected to hardness testing (Knoop) and surface profilometry. Data were analyzed using one-way analysis of variance and post hoc Scheffe test (p<0.05). Mean Knoop hardness values for the control group (air) ranged from 53.4 ± 3.4 (BF) to 89.5 ± 5.2 (ZT), while mean surface roughness values values ranged from 0.014 ± 0.002 (ZT) to 0.032 ± 0.001 (BT). All materials were significantly softened by FSL. The degree of softening by the different FSLs was material dependent. The hardness of giomers was most affected by citric acid and ethanol. The smoothest surface was generally observed with the control group. Giomer restoratives were significantly roughened by citric acid.

Morphological characteristics and chromosome behaviour in F1, F2 and BC1 progenies between Chrysanthemum x morifolium and Ajania pacifica

The garden chrysanthemum (Chrysanthemum x morifolium) variety 'Aoyunhuoju' (2n = 6x = 54) was crossed as female with Ajania pacifica (2n = 10x = 90) to produce an intergeneric F1 hybrid, which was used both as a source ofF2 progeny and as a parent for a first back-cross with 'Aoyunhuoju'. The morphology of all of the F1 hybrids and hybrid derivatives was intermediate with respect to the two parents, although the BC1 progenies resembled 'Aoyunhuoju' more closely than any of the F1 and F2 progenies did. In the F1 hybrid, the density of silvery hairs on the lower leaf surface and along the margin of the leaf was lower than in A. pacifica, while that in the BC1 generation, this trait was less prominent than in the F1. The somatic chromosome number of the F1, F2 (with an exception of F2-6 of a mainly 63) and BC1 generations was 2n = 8x = 72, 2n = 8x = 72 and 2n = 7x = 63 respectively, as expected. The hybrids and their derivatives retained a variable degree of fertility. There was a low frequency of meiotic chromosome pairing failure in all three hybrid generations, with most of the chromosomes involved as bivalents. Some BC1 individuals show potential for commercialization thanks both to their flower shape and the inheritance of the silvery leaf trait from A. pacifica.

Leukemia-related chromosomal loss detected in hematopoietic progenitor cells of benzene-exposed workers

Benzene exposure causes acute myeloid leukemia and hematotoxicity, shown as suppression of mature blood and myeloid progenitor cell numbers. As the leukemia-related aneuploidies monosomy 7 and trisomy 8 previously had been detected in the mature peripheral blood cells of exposed workers, we hypothesized that benzene could cause leukemia through the induction of these aneuploidies in hematopoietic stem and progenitor cells. We measured loss and gain of chromosomes 7 and 8 by fluorescence in situ hybridization in interphase colony-forming unit-granulocyte-macrophage (CFU-GM) cells cultured from otherwise healthy benzene-exposed (n=28) and unexposed (n=14) workers. CFU-GM monosomy 7 and 8 levels (but not trisomy) were significantly increased in subjects exposed to benzene overall, compared with levels in the control subjects (P=0.0055 and P=0.0034, respectively). Levels of monosomy 7 and 8 were significantly increased in subjects exposed to <10 p.p.m. (20%, P=0.0419 and 28%, P=0.0056, respectively) and ≥ 10 p.p.m. (48%, P=0.0045 and 32%, 0.0354) benzene, compared with controls, and significant exposure-response trends were detected (P(trend)=0.0033 and 0.0057). These data show that monosomies 7 and 8 are produced in a dose-dependent manner in the blood progenitor cells of workers exposed to benzene, and may be mechanistically relevant biomarkers of early effect for benzene and other leukemogens.

Radiological findings in 210 paediatric patients with viral pneumonia: a retrospective case study

OBJECTIVE

The objective of this study was to assess the radiological presentations of different types of viral pneumonia in children.

METHODS

Nasopharyngeal swab specimens and bronchial aspirate samples from children with acute respiratory infections were obtained and tested for influenza B, adenovirus, respiratory syncytial virus and parainfluenza (Types 1, 2 and 3) by direct immunofluorescence assay, or for influenza A (Subtype H1N1) by quantitative real-time polymerase chain reaction. The chest radiographs of the 210 confirmed cases of viral pneumonia were analysed retrospectively by two independent radiologists for the identification, characterisation and description of the distribution of imaging abnormalities. The cases were divided into six groups on the basis of confirmed causative viral agent, and radiographic findings were compared, analysed and presented.

RESULTS

The abnormal chest radiograph findings consisted of bilateral patchy areas of consolidation (n=133), interstitial lung disease (n=33), diffuse areas of air space consolidation (n=29) and lobar consolidation (n=15). The abnormalities were distributed bilaterally in 195 cases and observed more frequently in the lower zones than in other regions. The radiological findings varied significantly among the six groups (p=0.0050). Pairwise comparison showed significant difference between influenza A (H1N1) and adenovirus (p=0.0031) only.

CONCLUSION

The predominant radiological finding in paediatric viral pneumonia was bilateral patchy areas of consolidation. The radiological findings differed significantly only between adenovirus and influenza A pneumonia. The diagnosis of the specific causative organism requires laboratory confirmation.

First Report of Peanut Pod Rot Caused by Neocosmospora vasinfecta in Northern China

From 2006 to 2010, peanut (Arachis hypogaea) pod rot became more prevalent in northern China, especially in the Sha River drainage area. The incidence of pod rot ranged from 30 to 100%. Typical symptoms were black rot of the pods, but no obvious morphological abnormality of the aboveground parts of infected plants was observed. Brown or black spots appeared on many pods when initially infected and then all peanut pods became black and rotten. The same fungus was isolated from 54 surface-disinfested lesions (85.2% of all lesions) on potato dextrose agar (PDA) media. One isolate, designated as HBXLb, was chosen for further characterization. In culture, both anamorph and teleomorph were present. Mycelia of the fungus grew quickly (colonies were 3.2 cm in diameter in 3 days) and became white and floccose on PDA at 28°C. The hyaline, elongated-to-cylindrical conidia aggregated on the slimy heads of conidiogenous cells that developed on undifferentiated hyphae after incubation for 3 to 4 days. Conidial sizes varied from 5 to 10 × 1.5 to 3 μm (n = 50) and were mostly single celled. Some conidia appeared slightly curved. The morphology was consistent with Acremonium spp. Numerous ascomata (perithecia) formed within 10 to 14 days when incubated at 28°C under light and dark conditions. Perithecia were orange-brown, strawberry shaped (300 to 400 μm in diameter), and ostiolate on the top. Cylindrical asci, with an average size of 90 to 110 × 7.5 to 9 μm, were present inside the ascomata with each containing eight ascospores in a row. The ascospores were brownish, spherical to ellipsoidal, and 10 to 15 × 8 to 12 μm. The cultural and morphological characteristics of isolate HBXLb matched the description of N. vasinfecta (2). The internal transcribed spacer (ITS) region of rDNA was amplified by the primer pairs ITS4/ITS5. A 525-bp amplicon (ITS4-5.8s-ITS5) was obtained and sequenced (GenBank Accession No. HM461901). The ITS sequence was a 100% match to N. vasinfecta strain N-JXLN01 (GenBank Accession No. GU213063) by BLASTn in GenBank. Pathogenicity tests were conducted on detached pods of peanut cultivar Jihua 4. Forty surface-disinfested peanut pods were soaked in a conidial suspension (10⁵ conidia per ml) for 2 min and 40 pods were soaked in sterile water as a control. Then all peanut pods were maintained in moist petri dishes under darkness for 14 days at 28°C. Brown or black spots appeared on all pods inoculated with the fungus within 10 days, while the controls remained healthy. Symptoms were similar to those originally observed in the field, and N. vasinfecta could be reisolated from all infected pods. This fungus previously has been reported as the pathogen of foot rot of peanut in South Africa (1), Taiwan (4), and Australia (3). To our knowledge, this is the first report of peanut pod rot caused by N. vasinfecta in China. References: (1) S. W. Baard et al. Phytophylactica 17:49, 1985. (2) O. A. Cornely et al. Emerg. Infect. Dis. 7:149, 2001. (3) M. F. Fuhlbohm et al. Australas. Plant Dis. Notes 2:3, 2007. (4) J. W. Huang et al. Plant Pathol. Bull. 1:203, 1992.

Improvements in the establishment of a rat myocardial infarction model

Coronary artery ligation is widely used for myocardial infarction (MI) induction in rats but produces a large variation in infarct size--a major determinant of mortality. Accurate control of infarct size is critically important for the establishment of a useful animal model. This study determined the anatomical course of the left anterior descending coronary artery (LAD) by direct visualization in order to locate precisely the position of ligation. MI was induced by conventional methods (control group) or using a detailed anatomical knowledge of the LAD (experimental group). Triphenyltetrazolium chloride (TTC) staining was performed to compare infarct size, and electrocardiogram (ECG) changes were observed. The rate of MI induction was significantly higher in the experimental group than in the control group (89.5% vs 65.6%) and the size of infarction was more consistent in the experimental group. Direct visualization of the rat LAD allowed accurate identification of the ligation site, thereby controlling infarct size and improving the success rate of the rat model.

First Report of Neocosmospora striata Causing Peanut Pod Rot in China

In 2008, an outbreak of pod rot of peanut (Arachis hypogaea L.) occurred on most of the peanut cultivars in the Old Yellow River drainage area, the largest peanut-growing region in China. Disease incidence reached as high as 90% in some fields, causing severe yield losses. The black rot of pods and blackened, nonrotting taproots is similar to symptoms of peanut black rot caused by Cylindrocladium parasiticum, but the reddish orange perithecia of C. parasiticum were not found on the taproots close to the surface of the soil. The foliage of affected plants was generally asymptomatic, but some plants turned greener. This pod rot disease was further investigated in 2008 and 2010. Twenty-three Fusarium-like isolates were obtained from symptomatic, surface-disinfested pods with a frequency of 82%. These isolates were fast growing, with flat, thin, and grayish white colonies when cultured on potato dextrose agar (PDA) at 28°C for 3 to 4 days. The hyaline, elongated to cylindrical conidia, aggregated in slimy heads on conidiogenous cells developed from undifferentiated hyphae when observed with the light microscope. The size of conidia (single celled or one septum) varied from 3 to 9 μm long and 1.5 to 3.5 μm wide on the basis of the measurement of 50 spores. Some conidia appeared slightly curved. Ascomata formed within 10 to 14 days, with a punctate appearance on the colony. The cerebriform ascomata were dark brown, pyriform, ostiolate, glabrous, 120 to 170 × 90 to 130 μm, and with necks 30 to 50 μm long. Asci measured 60 to 90 × 6 to 10 μm, were cylindrical to cylindric-clavate, thin walled, and had an apical ring. Ascospore arrangement was obliquely uniseriate or partially biseriate, very pale yellow to hyaline, ellipsoidal, and measured 8 to 12 × 4.5 to 6 μm. Some spores had a median transverse straight or curved septum and were slightly constricted at the septum, with 6 to 10 thin, transverse, hyaline flanges. Morphological characteristics of the isolates with ascomata dark brown and ascospores with 6 to 10 transverse hyaline flanges matched the description for Neocosmospora striata (1). The internal transcribed spacer (ITS) region of rDNA was amplified from extracted template DNA with primer pairs ITS4/ITS5 and sequenced. A 591-bp amplicon (GenBank Accession No. HM461900) had 99% sequence identity with Fusarium solani (HQ607968 and HQ608009) and N. vasinfecta (GU213063), which indicated that these fungi belong to the genus Neocosmospora or Fusarium, although there is no direct sequence evidence that they are N. striata. N. striata has only been previously reported in Japan (2). This species is unique because of the dark brown ascomata and there is no comparable species (1). Koch's postulates were completed by surface-disinfesting 80 peanut pods of cv. Jihua 9813 and soaking them in conidial suspensions (10⁵ conidia/ml) for 2 min. Another 80 other pods soaked in sterile water served as controls. All peanuts were incubated in moist petri dishes under darkness at 28°C. Symptoms similar to those originally observed in the field formed within 10 days on all inoculated peanut pods and not the controls. N. striata was reisolated from all affected peanut pods. To our knowledge, this is first report of N. striata causing peanut pod rot in China and the first description of the anamorph of the fungus. References: (1) P. F. Cannon et al. Trans. Br. Mycol. Soc. 82:673, 1984. (2) S. Udagawa et al. Trans. Mycol. Soc. Jpn. 16:340, 1975.