[Association between obesity and risk for colorectal advanced adenoma].

Objectives: To understand the association between obesity and the risk for colorectal advanced adenoma. Methods: Community residents aged 45 to 74 who had participated in the Shanghai community-based colorectal cancer (CRC) screening project in 2008 were included in our study. Anthropometries information including body weight, height and risk factors for colorectal advanced adenoma were collected. Results on colonoscopic diagnosis and personal health records were used for supplementary outcome information retrieval. Multivariate Cox proportional hazard regression models were used to evaluate the hazard ratio (HR) and 95%CI of obesity on the risk for colorectal advanced adenoma. Results: 20 811 residents were followed up for 122 739.36 person-years, with a median follow-up time of 5.87 years. A total of 657 cases of advanced adenomas were identified. After adjusting for potential confounding risk factors such as age, sex, family history of CRC, level of education, marriage, cigarette smoking, alcohol drinking, foods intake including fat, fried or pickled, vegetables and fruits etc., the HR was 1.25 (95%CI: 1.04-1.51) for obese people when compared with the normal weight persons. Further stratified analysis by age, gender and family history of CRC, results showed that obese people had a much higher risk of colorectal advanced adenoma than those with normal weight (male: HR=1.57, 95%CI: 1.20-2.04; more than 60- year-old: HR=1.63, 95%CI: 1.23-2.16). Conclusion: Data from this large scale population-based study revealed that obesity might be an independent risk factor for colorectal advanced adenoma and the risk increases along with the increase of BMI in China.

First Report of Valsa leucostoma Causing Valsa Canker of Pyrus communis (cv. Duchess de' Angouleme) in China.

Pear is a popular fruit in the world market, and has been widely cultivated in China. Since 2008, a severe canker disease has consistently been observed on 20-year-old pear trees (Pyrus communis cv. Duchess de' Angouleme) grown in a nursery in Xingcheng, Liaoning Province, China. Observed symptoms include brown elongated ulcerative lesions (more than 20 cm in length in general), with red brown conidia produced on wet lesions. Reductions in tree vigor and yield were observed for infected trees. Tree mortality was observed for severe infections. To diagnose the pathogen, 15 canker samples were collected from five pear trees in April, 2012. Bark pieces (3 to 5 mm) taken from the border of healthy and diseased tissue were surface-disinfected with 0.1% mercury bichloride and 75% ethanol for 45 s, and placed on potato dextrose agar (PDA) medium at 25°C in darkness. Fungal colonies with a common colony morphology were consistently recovered from three samples. These fungal colonies were initially white, becoming olive green in 3 days. Conidia produced on colonies were hyaline, allantoid, and single-celled with average length × width of 6.04 (5.43 to 6.59) × 0.65 (0.51 to 0.73) µm, which were consistent with descriptions of Valsa leucostoma (1). Genomic DNA was extracted from a representative isolate F-LN-32b, and subjected to PCR amplification of the internal transcribed spacer region (ITS), ß-tubulin gene, and EF1 gene using the primer pairs ITS1/ITS4, Bt2a/Bt2b and EF1-728F/EF1-986R (3), respectively. Sequence alignment of the amplified fragments with the deposited data in NCBI showed that sequences of EF1, ITS, and ß-tubulin (GenBank Accession No. KF293296 to KF293298, respectively) of isolate F-LN-32b had the highest similarity of 99% to those of V. leucostoma strain 32-2w (JQ900340, JN584644, and JQ900374), and suggested that isolate F-LN-32b is a V. leucostoma strain. Pathogenicity tests was carried out by placing a 5-mm-diameter, 2-day-old mycelium agar plug of isolate F-LN-32b onto a punched bark hole of a detached 1-year-old pear shoot after it was surface disinfested with ethanol. Inoculated shoots were incubated at 25°C in plastic containers covered with plastic film. Pathogenicity assays were conducted on 18 pear varieties (cvs. Qiuyue, Jinshui 2, Hohsui, Huali 1, Cuiguan, Shinseiki, Xuehua, Dangshansu, Zaosu, Hongxiangsu, Yuluxiang, Nanguoli, Xizilv, Bartlett, Huanghua, Huashan, Duchess de' Angouleme, and Packham's) collected from a nursery in Wuhan, Hubei Province, China. Six shoots were inoculated for each variety and the assay was conducted three times. All inoculated shoots developed the typical canker symptoms after 6 days post inoculation (dpi) and sporulated at 25 dpi while the control shoots inoculated with non-colonized PDA plugs remained asymptomatic. Isolates recovered from inoculated samples were of the same morphology and ITS sequence as F-LN-32b. Based on these results, V. leucostoma was determined as the pathogen responsible for the Valsa canker disease on pear. Valsa mali var. pyri was identified as the only pathogen causing Valsa canker disease on pear in China (2). To our knowledge, this is the first report of V. leucostoma causing a canker disease on pear in China. References: (1) G. C. Adams et al. Australas. Plant Pathol. 35:521, 2006. (2) X. L. Wang et al. Mycologia 103:317, 2011. (3) T. J. White et al. Pages 315-322 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

The First Report of Leaf Spots in Aloe vera Caused by Nigrospora oryzae in China.

Aloe vera L. var Chinese (Haw) Berg is a popular ornamental plant cultivated worldwide, whose extracts are used in cosmetics and medicine. Aloe plants are commonly affected by leaf spot disease caused by Alternaria alternata in Pakistan, India, and the United States (1). An outbreak of Alternaria leaf spot recently threatened aloe gel production and the value of ornamental commerce in Louisiana (1). During the summer of 2011, leaf spot symptoms were observed on A. vera plants growing in several greenhouses and ornamental gardens in Wuhan, Hubei Province, China. In two of the greenhouses, disease incidence reached 50 to 60%. The initial symptoms included chlorotic and brown spots that expanded to 2 to 4 mm in diameter and became darker with age. Lesions also developed on the tips of 30 to 50% of the leaves per plant. In severe infections, the lesions coalesced causing the entire leaf to become blighted and die. In September of 2012 and February of 2013, 10 symptomatic A. vera leaves were collected randomly from two greenhouses and gardens in Wuhan. A fungus was consistently recovered from approximately 80% of the tissue samples using conventional sterile protocols, and cultured on potato dextrose agar (PDA). The colonies were initially white, becoming grey to black, wool-like, and growing aerial mycelium covering the entire petri dish (9 cm in diameter) plate within 5 days when maintained in the dark at 25°C. The conidia were brown or black, spherical to subspherical, single celled (9 to 13 µm long × 11 to 15 µm wide), borne on hyaline vesicles at the tip of conidiophores. The conidiophores were short and rarely branched. These colonies were identified as Nigrospora oryzae based on the described morphological characteristics of N. oryzae (2). Genomic DNA was extracted from a representative isolate, LH-1, and the internal transcribed spacer region was amplified using primer pair ITS1/ITS4 (3). A 553-bp amplicon was obtained and sequenced. The resulting nucleotide sequence (GenBank Accession No. KC519728) had a high similarity of 99% to that of strain AHC-1 of N. oryzae (JQ864579). Pathogenicity tests for strain LH-1 were conducted in triplicate by placing agar pieces (5 mm in diameter) containing 5-day-old cultures on A. vera leaves. Four discs were placed on each punctured surface of each leaf. Noncolonized PDA agar pieces were inoculated as controls. Leaves were placed in moist chambers at 25°C with a 12-h photoperiod. After 3 days, the inoculated leaves showed symptoms similar to those observed in the greenhouses. N. oryzae was reisolated from these spots on the inoculated leaves. No visible symptoms developed on the control leaves. The pathogenicity tests were performed twice with the same results. Based on the results, N. oryzae was determined as a pathogen responsible for the leaf spots disease on A. vera. N. oryzae has been described as a leaf pathogen on fig (Ficus religiosa), cotton (Gossypium hirsutum) and Kentucky bluegrass (Poa pratensis) (4), and to our knowledge, this is the first report of N. oryae causing leaf spot disease on A. vera worldwide. References: (1) W. L. da Silva and R. Singh. Plant Dis. 86:1379, 2012. (2) M. B. Ellis. Dematiaceous Hyphomycetes, CAB, Kew, Surrey, England, 1971. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) L. X. Zhang et al. Plant Dis. 96:1379, 2012.