[Establishment and validation of nomogram prediction model for complicated acute appendicitis].

Objective: To establish and internally validate a nomogram model for predicting complicated acute appendicitis (CA). Methods: The clinical data from 663 acute appendicitis patients from the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from October 2015 to October 2022 were retrospectively analyzed. There were 411 males and 252 females, aged (M (IQR)) 41 (22) years (range: 18 to 84 years). There were 516 cases of CA and 147 cases of uncomplicated acute appendicitis. The minimum absolute contraction and selection operator regression model was used to screen the potential relative factors of CA, and the screened factors were included in the Logistic regression model for multivariate analysis. Software R was used to establish a preoperative CA nomogram prediction model, the receiver operating characteristic curve of the model was drawn, and the value of area under the curve (AUC) was compared to evaluate its identification ability, and the Bootstrap method was used for internal verification. Results: The elderly (age≥60 years) (OR=2.428, 95%CI: 1.295 to 4.549), abdominal pain time (every rise of 1 hour) (OR=1.089, 95%CI: 1.072 to 1.107), high fever (body temperature≥39 ℃) (OR=1.122, 95%CI: 1.078 to 1.168), total bilirubin (every rise of 1 µmol/L) (OR=2.629, 95%CI: 1.227 to 5.635) were independent relative factors of CA (all P<0.05). The AUC of this model was 0.935 (95%CI: 0.915 to 0.956). After internal verification using the Bootstrap method, the model still had a high discrimination ability (AUC=0.933), and the predicted CA curve was still in good agreement with the actual clinical CA curve. Conclusion: The clinical prediction model based on the elderly (age≥60 years), prolonged abdominal pain time, high fever (body temperature≥39 ℃), and increased total bilirubin can help clinicians effectively identify CA.

First Report of Little cherry virus 2 in Flowering and Sweet Cherry Trees in China.

Many viruses infect Prunus spp. and cause diseases on them. During a survey of stone fruit trees in 2008 and 2009, flowering cherry (Prunus serrulata) and sweet cherry (P. avium) trees with foliar chlorosis and reddening, stem deformity, and tree stunting were observed in private orchards in Anning and Fumin counties of Yunnan Province. Some sweet cherry trees with severe symptoms yielded small and few fruits and had to be removed. Leaf samples were collected from 68 flowering cherry and 30 sweet cherry trees, either symptomatic or asymptomatic, from private orchards and community gardens in Kunming and counties Anning, Chenggong, Fumin, Jinning, Ludian and Yiliang. Total nucleic acids were extracted with a CTAB extraction method and tested by reverse transcription (RT)-PCR assay using virus-specific primers. Little cherry virus 2 (LChV-2), Cherry virus A (CVA), Prunus necrotic ringspot virus (PNRSV), and Prune dwarf virus (PDV) were detected and infection rates were 68.4, 16.3, 9.2, and 7.1%, respectively. Infection of LChV-2 was common in all counties except Ludian where the orchards were healthy. Of 68 infected trees, 29 were found to be infected with LChV-2 and CVA, PDV or PNRSV. LChV-2 was detected in this study by RT-PCR using a pair of novel primers, LCV2-1 (5'-TTCAATATGAGCAGTGTTCCTAAC-3') and LCV2-4 (5'-ACTCGTCTTGTGACATACCAGTC-3'), in 59 flowering cherry (87%) and 8 sweet cherry (27%) trees, respectively. The primer pair was designed according to alignment of three available LChV-2 sequences (GenBank Nos. NC_005065, AF416335, and AF333237) to amplify the partial RNA-dependent RNA polymerase gene (ORF1b) of 781 bp. The amplicons of selected samples (Anning26 and Yiliang60) were sequenced directly and sequences of 651 bp (GenBank No. HQ412772) were obtained from both samples. Pairwise comparisons and phylogenetic analysis of the sequences show that the two isolates are identical to one another and share 92 to 96% at the amino acid (aa) sequence level to those of other isolates available in the GenBank database. The sequence data confirm that these isolates are a strain of LChV-2 and genetic variation among different strains is relatively high (2). Biological and serological assays are not available for the LChV-2 detection; therefore, the LChV-2 infections of these trees were further confirmed by RT-PCR using primer pair LCV2-5 (5'-TGTTTGTGTCATGTTGTCGGAGAAG-3') and LCV2-6 (5'-TGAATACCCGAGAACAAGGACTC-3'), which amplified the helicase domain (ORF1a) of ~451 bp. The amplicons from samples Anning26 and Yiliang60 were cloned and sequenced. The 408-bp sequences (excluding primer sequences) were 92 to 98% identical at the aa sequence level to those of other isolates, confirming again their viral origin. LChV-2 (genus Ampelovirus, family Closteroviridae) (4) has been associated with little cherry disease (LChD), a widespread viral disease of sweet and sour cherries (1,3). The virus is transferred between geographic areas mainly by propagated materials. Ornamental and sweet cherries are important crops in China and LChD has the potential to cause significant economic losses. Thus, certified clean stock should be used to establish new orchards. To our knowledge, this is the first report of LChV-2 in cherries in China. References: (1) N. B. Bajet et al. Plant Dis. 92:234, 2008. (2) W. Jelkmann et al. Acta Hortic. 781:321, 2008. (3) B. Komorowska and M. Cieslinska, Plant Dis. 92:1366, 2008. (4) M. E. Rott and W. Jelkmann. Arch. Virol. 150:107, 2005.

First Report of Cherry virus A in Sweet Cherry Trees in China.

Plants in the genus Prunus of the family Rosaceae are important fruit and ornamental trees in China. In June of 2007, sweet cherry (Prunus avium) trees with mottling and mosaic symptoms were observed in a private garden near Kunming, Yunnan Province. Twenty-four samples, six each from sweet cherry, sour cherry (P. cerasus), flowering cherry (P. serrulata), and peach (P. persica) were collected from trees in private and community gardens in the area. The peach and sour and flowering cherry trees did not show any symptoms. Total nucleic acids were extracted using a cetyltrimethylammoniumbromide (CTAB) extraction method, and the extracts were tested for the following eight viruses by reverse transcription (RT)-PCR: American plum line pattern virus, Apple chlorotic leaf spot virus, Cherry green ring mottle virus, Cherry necrotic rusty mottle virus, Cherry virus A (CVA), Little cherry virus 1, Prune dwarf virus, and Prunus necrotic ringspot virus. Only CVA was detected in two symptomatic sweet cherry trees by RT-PCR with forward (5'-GTGGCATTCAACTAGCACCTAT-3') and reverse (5'-TCAGCTGCCTCAGCTTGGC-3') primers specific to an 873-bp fragment of the CVA replicase gene (2). The CVA infection of the two trees was confirmed by RT-PCR using primers CVA-7097U and CVA-7383L that amplified a 287-bp fragment from the 3'-untranslated region (UTR) of the virus (1). Amplicons from both amplifications were cloned and sequenced. Analysis of the predicted amino acid sequences of the 873-bp fragments (GenBank Accession Nos. EU862278 and EU862279) showed that they were 98% identical with each other and 97 to 98% with the type isolate of CVA from Germany (GenBank Accession No. NC_003689). The 286-bp sequences of the 3'-UTR (GenBank Accession Nos. FJ608982 and FJ608983) were 93% identical with each other and 93 to 98% with the type isolate. The sequence indicated that the three isolates were very similar and should be considered to be the same strain. CVA is a member of the genus Capillovirus in the family Flexiviridae and has been previously reported in Europe, North America, and Japan. The contribution of CVA to the symptoms observed and its distribution in China remain to be evaluated. To our knowledge, this is the first report of CVA in sweet cherry in China. References: (1) M. Isogai et al. J. Gen. Plant Pathol. 70:288. (2) W. Jelkmann. J. Gen. Virol. 76:2015, 1995.