[Clinical research progress in non-invasive positive pressure ventilation in 2023].

Non-invasive positive pressure ventilation (NPPV) is a widely used method of providing respiratory support in a variety of clinical settings, including emergency departments, general wards, and intensive care units. The relevant research articles on NPPV published between 1st October 2022 and 30th September 2023 were retrieved from Medline and reviewed. In the management of acute respiratory failure (ARF) associated with COVID-19, studies have highlighted the significant influence of regional economic status on the choice of respiratory support strategies. It has been observed that NPPV is more suitable for patients with mild to moderate acute respiratory distress syndrome (ARDS) than for those with severe ARDS, as the latter group has an increased risk of delayed intubation. In addition, patients with severe dyspnea tended to benefit more from NPPV compared with high flow nasal cannula (HFNC) and conventional oxygen therapy, with a reduced risk of self-induced lung injury. For non-COVID-19-related ARF, research shows no significant differences in mortality and intubation rates between HFNC and NPPV in patients with hypercapnic ARF. The updated HACOR score and ROX score have been validated to have a high predictive value for clinical outcomes in patients receiving NPPV for hypoxemic ARF. With regard to weaning from invasive mechanical ventilation, immediate application of NPPV after extubation showed a lower mortality rate compared to continued invasive weaning. Moreover, NPPV with active humidification significantly decreased the reintubation rate within 7 days after extubation compared with HFNC. The choice between using NPPV and HFNC should be based on the specific etiology of the patient's condition. The potential effect of noninvasive high-frequency oscillatory ventilation on CO2 clearance was also investigated.

[Clinical update in non-invasive positive pressure ventilation for respiratory failure in 2022].

In this article, we searched the research literatures related to clinical investigation of non-invasive positive pressure ventilation (NPPV) in acute respiratory failure(ARF)/chronic respiratory failure(CRF) between 1st October 2021 and 30th September 2022 through Medline, and reviewed the important advances. Three prospective randomized controlled studies related to the efficacy and safety of NPPV and/or high-flow nasal cannula oxygen therapy (HFNC) on patients with COVID-19 with ARF were reported, showing that NPPV (including continuous positive airway pressure and bilevel positive airway pressure) was able to reduce the intubation rate, but the efficacy of HFNC was contradictory. In addition, progress has been made in outcome prediction models for ARF treated with NPPV, NPPV-related cardiac arrest, and the impact of human-machine interface on NPPV treatment outcomes. The effects of NPPV as preoxygenation method before intubation was reported to be able to reduce severe desaturation during intubation, especially in obese population. The use of NPPV in extubated patients resulting in reduced reintubation rate was also studied. With regard to long-term home application of NPPV, five indicators of successful initiation were proposed, but the success rate was low in clinical practice. Some reports showed that psychological support could improve the adherence to NPPV. The results of these studies contributed to the rational selection and optimal application of NPPV in clinical practice.

[Clinical research progress in non-invasive positive pressure ventilation from 2020 to 2021].

Non-invasive positive pressure ventilation (NPPV), an essential respiratory support method, is widely used in acute/chronic respiratory failure and assisting rehabilitation in patients with chronic obstructive pulmonary disease (COPD). We searched the relevant research articles about NPPV published from 1st October 2020 to 30th September 2021 through Medline. Researches focusing on the clinical application and viral transmission protection during high-flow nasal cannula oxygen and NPPV in COVID-19, were mainly retrospective and of small sample size. It demonstrated that high-flow nasal cannula oxygen and NPPV might reduce intubation rates when treating patients with mild-to-moderate respiratory failure, but the risk of delayed intubation should draw particular precaution. When using NPPV in non-COVID-19-related de novo acute respiratory failure, diaphragm thickening fraction and tidal change of esophageal pressure were validated to predict the treatment outcome. In addition, some studies explored the compliance and related influencing factors associated with the treatment effects of early NPPV initiation on amyotrophic lateral sclerosis patients and the effects of NPPV on dynamic hyperinflation during exercise in COPD patients. Furthermore, the effectiveness of neurally adjusted ventilatory assist ventilation and a novel communication device optimizing the use of NPPV were also investigated and outlined.

[Comparison of short-term and long-term efficacy between robot-assisted and thoracoscopy-laparoscopy-assisted radical esophageal cancer surgery].

Objective: To explore the safety and short-term and long-term efficacy of robot-assisted radical esophageal cancer surgery. Methods: A prospective randomized controlled trial was conducted. Patients who were preoperatively diagnosed as stage 0-IIIB esophageal squamous cell carcinoma and suitable for minimally invasive surgery in our hospital from January 1, 2014 to June 30, 2018 were prospectively enrolled. Those of age ≥75 years having received preoperative neoadjuvant therapy, contradicted to anesthesia or operation due to severe complications, with history of thoracotomy or laparotomy, with concurrent malignant tumors, without complete informations or refusing to participate in this study were excluded. Participants were randomly divided into the thoracoscopy-laparoscopy group and the robot group using a random number table in ratio of 1:1. Preoperative clinicopathological data, surgical data and postoperative outcomes were recorded. The patients were followed up mainly by telephone. Follow-up endpoint was recurrence of esophageal cancer and death. Kaplan-Meier method was used to estimate survival rate. The survival difference between the two groups was analyzed using the log-rank test. Results: According to above criteria, a total of 192 esophageal cancer patients were enrolled finally, including 144 males and 48 females with mean age of (61.9±8.6) years. The robot group had 94 cases, including 72 males and 22 females with mean age of (61.3±8.2) years, and the thoracoscopy-laparoscopy group had 98 cases, including 72 males and 26 females with mean age of (62.4±9.1) years. There were no significant differences in baseline data between the two groups (all P>0.05). Operation was abandoned in one case in each group due to extensive pleural cavity metastasis and one case in each group was converted to thoracotomy. The success rate of operation was 97.9% (92/94) in the robot group and 98.0% (96/98) in the thoracoscopy-laparoscopy group (χ(2)=0.002, P=0.996). The number of lymph nodes dissected in the robot group was significantly higher than that in the thoracoscopy-laparoscopy group (29.2±12.5 vs. 22.8±13.3, t=3.433, P=0.001), while there were no significant differences in operative time, intraoperative blood loss, R0 resection rate, postoperative 30-day mortality, postoperative hospital stay, ICU stay, time to withdrawal of chest drainage tube, ICU readmission, and postoperative morbidity of complications between the two groups (all P>0.05). The median follow-up time was 21 (3 to 57) months. During the follow-up, 3 cases and 4 cases were lost, and 2 cases and 3 cases died of other diseases in the robot group and in the thoracoscopy-laparoscopy group respectively. Recurrence occurred in 39 cases during follow-up, including 14 recurrences in the robotic group with 1- and 3-year recurrence-free survival rates of 92.4% and 87.6% respectively and the median recurrence time of 15 (9 to 42) months. There were 25 recurrences in the thoracoscopy-laparoscopy group with 1- and 3-year recurrence-free survival rates of 81.7% and 67.9% respectively and the median recurrence time of 9 (3 to 42) months. There was significant difference in recurrence-free survival between the two groups (χ(2)=4.193, P=0.041). Conclusions: The robotic surgical system has good oncology effect and surgical safety in the radical operation of esophageal cancer, which deserves further research and promotion.

[An analysis of the new "three tubes" method in the treatment of spontaneous esophageal rupture].

To investigate the clinical efficacy, feasibility and safety of new "three tubes" method in the treatment of spontaneous esophageal rupture. A total of 22 patients with spontaneous esophageal rupture were retrospectively analyzed. Through the new "three tubes" method of treatment, patients achieved leak cured with reduced hospital stay, less medical expenses and early resumption of oral diet. The new "three tubes" method for spontaneous esophageal rupture has the advantages of easy handling, minimal invasion, few complication and exact curative effect.

Molecular characterization of a novel bipartite begomovirus isolated from Lycianthes biflora in China.

A bipartite begomovirus isolate GD was isolated from Lycianthes biflora plants showing yellow mosaic symptoms in Nanxiong, Guangdong Province, China. The apparently full-length DNA-A and DNA-B viral components were cloned after enrichment of circular DNA by rolling circle amplification, restriction digestion, cloning, and DNA sequencing. The DNA-A component (2752nt, KT582302) shares highest (80.2%) nucleotide (nt) sequence identity with tomato leaf curl Sulawesi virus [Indonesia-Sulawesi-Langowan F101-2006] (ToLCSuV- [ID-Sul -LanF09-06], FJ237618), reported in Indonesia as causing yellow leaf curl disease of chilli pepper. The DNA-B component (2704nt, KT582303) shares highest (76.3%) nt sequence identity with pepper yellow leaf curl Indonesia virus-[Indonesia-tomato2-2005] (PepYLCIV-[ID-Tom2-05 AB213599) reported in Indonesia, and associated with yellow leaf curl disease in tomato. Based on the ICTV guidelines for begomoviral species demarcation, the virus is a new, previously undescribed bipartite begomovirus species for which the name "Lycianthes yellow mosaic virus" is proposed.

[Evaluation and influencing factors of surgical margin status of oral squamous cell carcinoma].

Surgical resection with adequate margins is an essential component of the treatment for patients with oral squamous cell carcinoma (OSCC). A distance of 5 mm or more between healthy tissue to the tumor front is generally accepted as a safe margin. It is very important for surgeons to precisely evaluate the resection area of tumor both pre- and intra-operatively and try to achieve a safe margin, which will result in a decreased risk of local recurrence. The relationship of surgical margin status to patients' prognosis, and factors which will affect surgical margin distance demand are discussed in this paper. We recommend that adequate margins evaluation should take consideration of many factors such as anatomical location, depth of tumor invasion, pattern of tumor invasion, mucosal dysplasia grade and so on. With the development of molecular biology, surgical margin study at molecular level can give us a new strategy to evaluate its adequacy.

Mutational analysis of mitochondrial tRNA genes in patients with lung cancer.

Mutations in mitochondrial tRNA (mt-tRNA) genes have been found to be associated with various diseases including lung cancer. To understand the possible relationship between mtRNA mutations and lung cancer, we sequenced the 22 mt-tRNA genes from 200 lung cancer blood samples, as well as 100 healthy subjects. As a result, five mutations were identified including the tRNAAla T5655C, tRNAArg T10454C, tRNALeu(CUN) A12330G, tRNASer(UCN) T7505C and tRNAThr G15927A. These mutations were absent in the healthy subjects. These mutations and polymorphisms were localized at the highly conserved nucleotides of the corresponding mitochondrial tRNAs, which are critical for the tRNA steady state level and may result in failure in the tRNA metabolism. Moreover, through the application of the pathogenicity scoring system, we found that only the T10454C mutation should be classified as a "neutral polymorphism," while the other mutations were regarded as "definitely pathogenic." Taken together, our data indicate that tRNA genes are the hot-spots for pathogenic mutations associated with lung cancer. Our findings may provide valuable information for pathophysiology, management and genetic counseling of lung cancer.

Identification and molecular characterization of two begomoviruses from Pouzolzia zeylanica (L.) Benn. exhibiting yellow mosaic symptoms in adjacent regions of China and Vietnam.

Two monopartite begomoviruses were isolated from Pouzolzia zeylanica (L.) Benn. plants showing yellow mosaic symptoms in Gaoyao, Guangdong Province, China (GD1) and in Phu Tho, Vietnam (VN), respectively. A comparison of the complete genome sequence of GD1 (2,739 nucleotides [nt]) with VN (2,741 nt) indicated that they shared 86.2 % nt sequence identity. GD1 and VN shared the highest nucleotide sequence identity at 86.7 % and 91.4 % respectively, with isolate TY01 of pouzolzia golden mosaic virus (PGMV-TY01), another begomovirus isolated from P. zeylanica. Phylogenetic analysis revealed that GD1, VN, and PGMV-TY01 were members of a distinct begomovirus clade. Based on the ICTV guidelines for begomoviral species demarcation, GD1 belongs to a new begomovirus species, for which the name Pouzolzia yellow mosaic virus is proposed. Likewise, VN represents a previously unreported strain of PGMV. Recombination analysis predicted that VN was a recombinant between PGMV-TY01 and ageratum yellow vein China virus isolate G13 (AYVCNV-G13), and that PGMV-TY01 and VN were likely the parents of GD1 through recombination with allamanda leaf curl virus isolate G10 (AlLCV-G10), a begomovirus endemic to Guangdong Province of China.

First Report of Sweet potato leaf curl Georgia virus Infecting Tall Morning Glory (Ipomoea purpurea) in China.

In September 2013, tall morning glory (Ipomoea purpurea) plants showing vein yellowing and leaf curl symptoms typical of a begomovirus infection were observed in Jingzhou, Hubei Province, China. Total nucleic acids were extracted from a symptomatic plant using cetyltrimethylammonium bromide (CTAB). Rolling circle amplification (RCA) was conducted using TempliPhi kit (GE Healthcare) to recover the genome of a putative begomovirus. Digestion of the RCA product with PstI yielded a ~2.8 kbp DNA fragment suggestive of a monomerized begomoviral genome. The fragment was cloned and sequenced and the sequence was deposited in GenBank under accession no. KF769447. SDTv1.0 (species demarcation tool) analysis revealed that the putative begomovirus showed 98.5 and 92.0% nucleotide sequence identity with Sweet potato leaf curl Georgia virus (SPLCGV)-[China:Hebei:2011] (GenBank Accession No. JX448368) and SPLCGV-[US:Geo:16] (AF326775), respectively. The virus contained six ORFs, which encoded proteins showing 96.5 to 100% and 90.6 to 95.6% amino acid sequence identity with their counterparts of SPLCGV-[China:Hebei:2011] and SPLCGV-[US:Geo:16], respectively. Thus, the virus should be considered as an isolate of SPLCGV-[China:Hebei:2011]. Tall glory morning in a nearby field (which covers an area of 3 square kilometers) was surveyed and 70 to 100% of plants were found showing symptoms reminiscent of begomoviral infection. Total nucleic acid was extracted from 13 randomly selected (10 symptomatic and 3 healthy) plants and used as templates for PCR with a pair of specific primers (5'-CGCAGCCTTTCCACACTATC-3'/5'-AAAACAGTTTGGGCTCGGTC-3') designed according to the sequence described above. Positive results were obtained for all of the symptomatic, but none of the healthy-looking tall morning glory plants. SPLCGV (genus Begomovirus, family Geminiviridae) was reported to infect sweet potato (I. batatas) in the United States (4), India (2), and China (3). To our knowledge, this is the first report of SPLCGV infecting tall morning glory in China. Also, it is the first report of a geminivirus in Hubei, a province of central China. Whereas the finding of SPLCGV in sweet potato (3) may be a result of vegetative propagation of this crop, the detection of SPLCGV in tall morning glory, an annual plant, raises the possibility that this virus is transmissible and is spreading in China. References: (1) B. Muhire et al. Arch. Virol. 158:1411, 2013. (2) G. Prasanth and V. Hegde. Plant Dis. 92:311, 2008. (3) Y. Qin et al. Plant Dis. 97:1388, 2013. (4) R. A. Valverde and D. L. Gutierrez. Rev. Mex. Fitopatol. 21:128, 2003.

First Report of Tomato yellow leaf curl Kanchanaburi virus Infecting Eggplant in Laos.

Tomato yellow leaf curl Kanchanaburi virus (TYLCKaV) is a bipartite begomovirus (genus Begomovirus, family Geminiviridae) reported to infect tomato and eggplant in Thailand and Vietnam (1,2). In April 2013, eggplant (Solanum melongena L.) plants exhibiting yellow mosaic symptoms were found in a suburb of Vientiane, Laos. Three symptomatic samples were collected. Total DNA was extracted from leaves by the CTAB method, and used as template for PCR using the degenerate primer pair AV494/CoPR (3). The PCR results suggested that the plants were infected by a begomovirus. The begomoviral genome was amplified by rolling circle amplification (RCA) with TempliPhi kit (GE Healthcare) following the manufacturer's protocol. RCA product was digested with the endonucleases BamH I, EcoR I, Hind III, Kpn I, Pst I, and Xba I, respectively. The fragments about 2.1 kbp (with Pst I digestion) and 1.5 kbp (with Xba I digestion) in size were cloned and sequenced. The sequence of the 2.1-kbp fragment showed similarity with begomovirus DNA-A component. A pair of primers for amplification of the full-length DNA-A, AF (5'-CTTCATCGTTTCTCAGCATCAT-3') and AR (5'-CACTTGCACACGATCTCTAAGA-3') were designed from the 2.1-kbp sequence. The full-length DNA-A was 2,752 nucleotides and encoded six putative ORFs (GenBank Accession No. KF218820). The sequence of the 1.5-kbp fragment shared similarity with begomoviruses DNA-B. The begomoviral circular DNA-B was amplified using the pair of primers BF (5'-GTAACAGCCGAAGTGCACG-3') and BR (5'-AATGGAGAGACACCAGTCTGCC-3') designed from the 1.5-kbp sequence. PCR yielded a product of expected size (~1.4 kbp). The full-length DNA-B sequence was obtained by assembling the two sequences. The DNA-B was 2,734 nucleotides and encoded two putative ORFs (GenBank Accession No. KF218821). The sequences of DNA-A and DNA-B of isolate Laos shared the highest nucleotide sequences identities at 99.0% and 98.0% with those of TYLCKaV-[TH:Kan 1:01] (AF511529), and [TH:Kan 2:Egg:01] (AF511527), respectively. The results indicated that the virus associated with eggplant yellow mosaic disease was an isolate of TYLCKaV. To our knowledge, this is the first report of this begomovirus in Laos. Our results indicate that this virus may be spreading in Southeast Asia and scientists there should be aware of this virus when developing begomovirus-resistant varieties of tomato or eggplant. References: (1) S. K. Green et al. Plant Dis. 87:446, 2003. (2) C. Ha et al. J. Gen. Virol. 89:312, 2008.(3) Z. F. He et al. Arch. Virol. 154:1199, 2009.

First Report of Wild tomato mosaic virus Infecting Tobacco (Nicotiana tabacum) in China.

Wild tomato mosaic virus (WTMV), a potyvirus, has been reported in Laichau, Vietnam, infecting Solanum torvum (wild tomato) in 2008 (3), and Kanchanaburi, Thailand, infecting Capsicum spp. in 2013 (KF250353). In mid-May 2013, Nicotiana tabacum showing yellowing, mosaic, and/or ringspot symptoms were found in natural tobacco fields of Nanxiong, Guangdong Province, China. Total RNA was extracted from symptomatic leaves and reverse transcribed with M4T (5'-GTTTTCCCAGTCACGAC (T)15-3') as the 3' anchoring primer (1). The cDNA was used as template in a PCR assay using primers M4: 5'-GTTTTCCCAGTCACGAC-3' and Sprimer: 5'-GGXAAYAAYAGYGGXCAZCC-3', which amplifies a region comprising part of the NIb protein gene, the entire coat protein (CP) gene and the 3' nontranslated region (UTR) of a potyvirus (1). A ~1,700-bp product was amplified from the cDNA derived from three of the five diseased plants. The product (KF639967) showed 87% and 84% nucleotide sequence identities with those of WTMV isolates KAN and Laichau, respectively. The CP deduced from the sequence of the product shared 87% and 86% nucleotide and 94% and 93% amino acid sequence identities with those of WTMV isolates KAN and Laichau, respectively. The 3'-UTR of the putative virus shared 93% and 92% nucleotide sequence identities to those of WTMV isolates KAN and Laichau, respectively. Thus, according to the molecular criteria for potyvirus species demarcation (2), the virus we identified should be an isolate of WTMV (isolate GD1). One of the diseased samples was homogenized in 0.1 mol/liter phosphate buffer (pH 7.0) and used to inoculate the potyvirus to healthy, two to four leaf-stage Capsicum annuum L., N. tabacum, and N. benthamiana. The inoculated, as well as mock-treated plants, which were inoculated only with phosphate buffer, were grown in soil under 12 h day/12 h night at 25°C. All inoculated N. tabacum and N. benthamiana plants developed yellowing and mosaic symptoms by 14 days post inoculation (dpi). For N. benthamiana, the symptom became very severe by 21 dpi and some diseased plants died prematurely. About 10% of inoculated C. annuum L. developed very mild veinal chlorosis 18 dpi. Cloning and sequencing experiments showed that all the symptomatic plants tested were WTMV positive, but Cucumber mosaic virus, Tobacco mosaic virus, and Tobacco etch virus negative. To our knowledge, this is the first report of WTMV in China. Also, it is the first report that WTMV infects Nicotiana spp. Although further experiments are needed to definitively attribute the disease observed in the field to WTMV, our results indicate that WTMV, which forms a monophyletic clade with a number of other potyviruses infecting Solanaceae species in phylogenetic analysis, is widely distributed, or is spreading in Southeast Asia. It may pose a threat to Solanaceae species cultivation in this region. References: (1) Chen et al. Arch. Virol. 146:757, 2001. (2) Adams et al. Arch. Virol. 150:459, 2005. (3) Ha et al. Arch. Virol. 153:25, 2008.

Molecular characterization of a novel monopartite begomovirus isolated from Pouzolzia zeylanica in China.

The complete genome sequence of a monopartite begomovirus isolate TY01 was obtained from diseased Pouzolzia zeylanica plants exhibiting golden mosaic symptoms in Baise, Guangxi Province, China. It consisted of 2723 nucleotides (nt) and encoded two ORFs (CP and AV2) in the virion-sense DNA and five ORFs (AC1-AC5) in the complementary-sense DNA. Compared with the DNA-A sequences of other begomoviruses, it has the highest (78.5 %) nucleotide sequence identity with ageratum yellow vein virus (AYVV) isolate AFSP6D from Thailand, which is less than the 89 % identity in the complete genome that has been defined as the threshold value for demarcation of species in the genus Begomovirus, family Geminiviridae. Phylogenetic analysis showed that TY01 was grouped in a separate clade from the other 28 begomovirus isolates. These results indicate that isolate TY01 is a member of a novel Begomovirus species, for which the name "Pouzolzia golden mosaic virus" (PGMV) is proposed.

First Report of Bacterial Wilt Caused by Ralstonia solanacearum on Ageratum conyzoides in China.

Ageratum conyzoides L. is believed to act as reservoir host for many plant diseases. In June 2011, a 30% incidence of bacterial wilt on A. conyzoides was observed in a field of Rhizoma kaempferiae in Yangchun city of Guangdong province. The initial symptoms were wilting of the apical leaves during the day, which recovered at night. After 4 to 6 days, the leaves became totally necrotic. The basal stems of the diseased plants were blackened and the vascular tissue turned brown. To investigate the disease etiology before understanding the disease link between A. conyzoides and R. kaempferiae, 10 plants with typical wilting symptoms were collected from the field. A total of 10 bacterial isolates were isolated from the vascular tissue of each diseased plant on tripheny tetrazolium chloride (TZC) medium. After incubation at 30°C for 2 days, the plates had large, irregular round, fluidal, white colonies with a pink center. Thirty healthy A. conyzoides plants at the four- to six-leaf growth stage were inoculated by injuring the roots and soaking them in a bacterial suspension (1 × 108 cfu/ml) for 20 min with the 10 bacterial isolates separately, and planted in 10-cm pots with sterile gardening soil in a glasshouse (28 to 35°C). Sterile water was used as a negative control. Five days after inoculation, a few leaves of the inoculated plants began to exhibit wilting. The inoculated plants eventually showed the same symptoms as those in the field. The same bacterium was reisolated from inoculated plants. The 30 negative control plants did not have wilt symptoms. With the same inoculation procedure, the bacterium also caused wilting on tomato (25 of 30), pepper (10 of 30), eggplant (2 of 30), ginger (11 of 15), and R. kaempferiae (8 of 15). Using the universal bacterial 16S rDNA primer set 27f/1541R (3), approximately 1,400 bp-fragments were amplified from the 10 isolates, respectively. The sequences for the 10 fragments (GenBank Accession Nos. JX294065 to JX294074) were identical and had 100% sequence identity with 16S rDNA of R. solanacearum GMI1000 (AL646052). The 10 isolates were able to oxidize disaccharides (lactose, maltose, and cellobiose) and hexose alcohols (mannitol, dulcitol, and sorbitol). According to Hayward's classification, all isolates were biovar 3 (2). Based on the pathogenicity tests, carbohydrate utilization, and near full-length 16S rDNA sequences, the bacterial isolates from the diseased A. conyzoides belonged to race 4 and biovar 3 of R. solanacearum. Furthermore, the specific 280-bp and 140-bp fragments were respectively amplified from all 10 isolates by using the multiplex PCR (1). In addition, specific 165-bp fragments were amplified from all the isolates using the specific primers AKIF/AKIR (3), which indicates the bacterium belongs to R. solanacearum Phylotype I. To our knowledge, this is the first report of a disease caused by R. solanacearum on A. conyzoides in China. References: (1) M. Fegan and P. Prior. Page 449 in: Bacterial Wilt Disease and the Ralstonia solanacearum Species Complex. C. Allen et al., eds. The American Phytopathological Society. St. Paul, MN, 2005. (2) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (3) M. Horita et al. J. Gen. Plant Pathol. 70:278, 2004.

First Report of Potato Blackleg Disease Caused by Pectobacterium atrosepticum in Guangdong China.

Potato (Solanum tuberosum L.) is an important crop in China. In 2013, diseased potatoes exhibiting blackleg and soft rot symptoms were found in the winter potato growing areas of Huizhou city, Guangdong Province, China, with an incidence of approximately 20%. Initially, the stem bases of infected plants blackened and this symptom spread upward. Later, foliage of the diseased plants became yellow and the stem rotted with vascular discoloration. Twenty diseased plants with typical black leg symptoms were collected from a 10-ha potato field with approximately 60,000 potato plants per hectare. A bacterium with small, irregular, round, fluidal, white colonies was isolated from the vascular tissue of all diseased plants on nutrient agar at 26°C for 2 days. Ten strains were randomly selected for pathogenicity assays. Potato plants (cv. Favorita) at the five- to six-leaf stage were inoculated by injecting their stems with 1 ml of each strain in a bacterial suspension (3 × 108 CFU/ml). The inoculated potato plants were incubated at 16 to 21°C and 65 to 85% humidity, and exhibited the same symptoms as the diseased potato plants in the field by 3 to 5 days post inoculation (dpi). The bacterium was reisolated from the diseased tissue (stem) of the inoculated potato plants and produced characteristic pits on crystal violet pectate medium (1). The bacterium utilized a-methyl glucoside, glucose, lactose, maltose, cellobiose, raffinose, melibiose, and citrate, but not d-arabitol, sorbitol, or malonate. The bacteria also gave a positive reaction for catalase and production of reducing substances from sucrose, but gave a negative reaction for oxidase, production of phosphatase, and indole. Using the universal bacterial 16S rDNA primer set, 27f/1541R (4), 1,400-bp fragments were amplified from the 10 strains. The sequences of the 10 fragments (GenBank Accessions KC695819 to KC695828) were identical and had 100% sequence identity with 16S rDNA of Pectobacterium atrosepticum CFBP 1526 (JN600332). Further, the 438-bp and 690-bp fragments were respectively amplified from all 10 strains with the P. atrosepticum-specific primers Y45/Y46 (3) and ECA1f/ECA2r (2). To our knowledge, this is the first report of potato blackleg disease caused by P. atrosepticum (formerly named as Erwinia carotovora subsp. atroseptica) in Guangdong Province, China. References: (1) D. Cupples et al. Phytopathology 64:468, 1974. (2) S. H. De Boer et al. Phytopathology 85:854, 1995. (3) D. Frenchon et al. Potato Research 41:63, 1995. (4) M. Horita et al. J. Gen. Plant Pathol. 70:278, 2004.

First Report of Brown Spot Disease Caused by Neoscytalidium dimidiatum on Hylocereus undatus in Guangdong, Chinese Mainland.

Pitahaya or dragon fruit [Hylocereus undatus (Haw.) Britton & Rose] is one of the most popular tropical fruits in the world. In China, it is widely planted in Guangdong, Guangxi, Hainan, and Taiwan. In July 2011, a new pitahaya disease was found in Conghua City and Yunfu City, Guangdong Province, China, characterized by many small, circular, reddish brown spots over the diseased stems. The spots continuously expanded, and ultimately formed large areas of canker on stems. It is similar to pitahaya stem canker disease caused by Neoscytalidium dimidiatum in Taiwan (1). Pieces of tissues were collected from the lesion margins. After surface disinfestations with 1% sodium hypochloride for 1 min and rinsing in sterile water three times, the diseased tissues were placed on potato dextrose agar medium plates (PDA) and incubated at 28°C for 3 days. A dark, fast-growing fungus was isolated from all samples. For identification, single-spore cultures were grown on PDA in an incubator at 28°C. After 5 days, colonies with dark gray to black aerial mycelium formed. The colonies produced abundant conidia that occurred in arthric chains in aerial mycelium. The conidia were disarticulating, cylindrical-truncate, oblong-obtuse to doliform, dark brown, zero- to one-septate, and averaged 7.56 (5.46 to 10.30) × 6.20 (3.79 to 8.93) µm. The teleomorph was never observed in PDA culture. Based on these characteristics, the fungus was identified as N. dimidiatum (Penz.) Crous & Slippers (2). The internal transcribed spacer (ITS) regions of rDNAs from two isolates were amplified by primers ITS1 and ITS4 (3), and then sequenced. Both sequences were completely identical and 579 bp long (GenBank Accession Nos. JX128103 and JX128104), with 99% identity to that of N. dimidiatum previously deposited (Accession No. HQ439174). To confirm its pathogenicity, six healthy detached stems of pitahaya designed as two replicates were inoculated by injecting 10 µl of conidia suspension (1 × 106 conidia per ml). Three stems were inoculated with sterile water as controls. The inoculated stems were kept in an incubator at 28°C in dark. The stems exhibited the same symptoms as described above after 10 days post inoculation, whereas no symptoms developed on the control stems. The fungus was reisolated from the lesions of the inoculated stem. These results indicated that N. dimidiatum was the pathogen of pitahaya brown spot disease. To our knowledge, this is the first report of brown spot caused by N. dimidiatum on H. undatus on the Chinese mainland. References: (1) M. F. Chuang et al. Plant Dis. 96:906, 2012. (2) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

Thymic expression of the main immunogenic region of titin in thymomatous myasthenia gravis.

Antititin antibody occurs in the serum of myasthenia gravis (MG) patients with thymoma (MGT), and is a diagnostic marker for the disease. The mechanism that triggers MGT development is, however, unclear. This study evaluated the role of the main immunogenic region (MIR) of titin in MGT pathogenesis. Titin MIR antiserum (antibody titre 1:16) was obtained and an in situ immunohistochemical study of thymomatous tissue samples was performed. Strong immunostaining for titin MIR was observed on epithelial cell membranes in MGT patients, and the degree of immunostaining was directly proportional to the number of epithelial cells in thymomatous tissue. Serum antititin antibody levels were closely related to titin MIR levels in thymoma cells; however, titin MIR levels did not appear to be related to MG severity. Antititin antibody may be a good surrogate marker for thymoma but is probably not involved in the pathogenesis of MGT.

Molecular characterization of a distinct begomovirus infecting Allamanda cathartica in Guangdong, China.

Virus isolate G10 was obtained from diseased allamanda plants showing leaf curl symptoms in Guangdong, China. The full-length nucleotide sequence of a DNA-A-like molecule of G10 was cloned and sequenced; it comprises 2755 nucleotides and has a typical begomovirus genome organization with six conserved open reading frames. When compared with the DNA-A sequences of other begomoviruses, the complete nucleotide sequence of DNA-A of G10 had the highest sequence identity (81.2%) to tomato leaf curl Guangdong virus (ToLCGuV) isolate G2. This is less than the 89% identity in the complete genome that has been defined as the threshold value for demarcation of species in the genus Begomovirus. The molecular data show that isolate G10 from allamanda in Guangdong, China is a distinct Begomovirus species, for which the name Allamanda leaf curl virus (AlLCV) is proposed.

[Inhibitory effect of selenium on complement activation and its clinical significance].

In immunopathological study of complement activation, we recognised a marked inhibitory effect of sodium selenite on the haemolysis induced by complement fixation in vitro, thereafter on mouse complement activation in vivo induced by endotoxin, inulin or aggregated IgG indicated by a special rocket immunoelectrophoresis test of C3 split products. The effective inhibition usually began at the concentration of 0.002 mol/L of selenite in vitro, and 20 micrograms/25 g BW intravenously in vivo. The inhibitory effect was found evident on alternative pathway. This inhibitory effect was further identified in cases of epidemic haemorrhagic fever (EHF) treated by multiple dosages of 2 mg selenite per day in the first 9 days of hospitalization other than general management of 80 severe cases, including fulminant and moderate grade EHF cases. C3 activation was inhibited accordingly and the mortalities also dropped markedly from 100% of the non-treated group to 36% of the selenite treated group of fulminant type, and from 22% to zero of severe type group.