UvVelC is important for conidiation and pathogenicity in the rice false smut pathogen Ustilaginoidea virens

Rice false smut disease is one of the most significant rice diseases worldwide. Ustilaginoidea virens is the causative agent of this disease. Although several developmental and pathogenic genes have been identified and functionally analyzed, the pathogenic molecular mechanisms of U. virens remain elusive. The velvet family regulatory proteins are involved in fungal development, conidiation, and pathogenicity. In this study, we demonstrated the function of the VelC homolog UvVELC in U. virens. We identified the velvet family protein UvVELC and characterized its functions using a target gene deletion-strategy. Deletion of UvVELC resulted in conidiation failure and pathogenicity. The UvVELC expression levels during infection suggested that this gene might be involved in the early infection process. UvVELC is also important in resistance to abiotic stresses, the utilization efficiency of glucose, stachyose, raffinose, and other sugars, and the expression of transport-related genes. Moreover, UvVELC could physically interact with UvVEA in yeast, and UvVELC/UvVEA double-knockout mutants also failed in conidiation and pathogenicity. These results indicate that UvVELC play a critical role in the conidiation and pathogenicity in U. virens. Functional analysis indicated that UvVELC-mediated conidiation and nutrient acquisition from rice regulates the pathogenicity of U. virens. Understanding the function of the UvVELC homolog could provide a potential molecular target for controlling rice false smut disease.

Sulfur oxidation and reduction are coupled to nitrogen fixation in the roots of the salt marsh foundation plant Spartina alterniflora

Heterotrophic activity, primarily driven by sulfate-reducing prokaryotes, has traditionally been linked to nitrogen fixation in the root zone of coastal marine plants, leaving the role of chemolithoautotrophy in this process unexplored. Here, we show that sulfur oxidation coupled to nitrogen fixation is a previously overlooked process providing nitrogen to coastal marine macrophytes. In this study, we recovered 239 metagenome-assembled genomes from a salt marsh dominated by the foundation plant Spartina alterniflora, including diazotrophic sulfate-reducing and sulfur-oxidizing bacteria. Abundant sulfur-oxidizing bacteria encode and highly express genes for carbon fixation (RuBisCO), nitrogen fixation (nifHDK) and sulfur oxidation (oxidative-dsrAB), especially in roots stressed by sulfidic and reduced sediment conditions. Stressed roots exhibited the highest rates of nitrogen fixation and expression level of sulfur oxidation and sulfate reduction genes. Close relatives of marine symbionts from the Candidatus Thiodiazotropha genus contributed ~30% and ~20% of all sulfur-oxidizing dsrA and nitrogen-fixing nifK transcripts in stressed roots, respectively. Based on these findings, we propose that the symbiosis between S. alterniflora and sulfur-oxidizing bacteria is key to ecosystem functioning of coastal salt marshes.

Spatiotemporal Evolution of Developing Palate in Mice

The intricate formation of the palate involves a series of complex events, yet its mechanistic basis remains uncertain. To explore major cell populations in the palate and their roles during development, we constructed a spatiotemporal transcription landscape of palatal cells. Palate samples from C57BL/6 J mice at embryonic days 12.5 (E12.5), 14.5 (E14.5), and 16.5 (E16.5) underwent single-cell RNA sequencing (scRNA-seq) to identify distinct cell subsets. In addition, spatial enhanced resolution omics-sequencing (stereo-seq) was used to characterize the spatial distribution of these subsets. Integrating scRNA-seq and stereo-seq with CellTrek annotated mesenchymal and epithelial cellular components of the palate during development. Furthermore, cellular communication networks between these cell subpopulations were analyzed to discover intercellular signaling during palate development. From the analysis of the middle palate, both mesenchymal and epithelial populations were spatially segregated into 3 domains. The middle palate mesenchymal subpopulations were associated with tooth formation, ossification, and tissue remodeling, with initial state cell populations located proximal to the dental lamina. The nasal epithelium of the palatal shelf exhibited richer humoral immune responses than the oral side. Specific enrichment of Tgfβ3 and Pthlh signals in the midline epithelial seam at E14.5 suggested a role in epithelial-mesenchymal transition. In summary, this study provides high-resolution transcriptomic information, contributing to a deeper mechanistic understanding of palate biology and pathophysiology.

A rapid, equipment-free method for detecting avirulence genes of Pyricularia oryzae using a lateral flow strip-based RPA assay

Rice blast, caused by Pyricularia oryzae, is one of the most destructive rice diseases worldwide. Using resistant rice varieties is the most cost-effective way to control rice blast. Consequently, it is critical to monitor the distribution frequency of avirulence genes in rice planting field to facilitate the breedings of resistant rice varieties. In this study, we established a rapid RPA-LFD detection system for the identification of AvrPik, Avr-Piz-t and Avr-Pi9. The optimized reaction temperature and duration were 37°C and 20 min, indicating that the reaction system could be initiated by body temperature without relying on any precision instruments. Specificity analysis showed that the primer and probe combinations targeting three Avr genes exhibited a remarkable specificity for at genus-level detection. Under the optimized condition, the lower detected thresholds of AvrPik, Avr-Piz-t and Avr-Pi9 were 10 fg/μl, 100 fg/μl and 10 pg/μl, respectively. Notably, the detection sensitivity of three Avr genes was much higher than that of PCR. In addition, we also successfully detected the presence of AvrPik, Avr-Piz-t and Avr-Pi9 in the leaf and panicle blast lesions with the RPA-LFD detection system. In particular, the genomic DNA was extracted using the simpler PEG-NaOH rapid extraction method. In summary, we developed the RPA detection system for AvrPik, Avr-Pi9 and Avr-Piz-t, combined with the PEG-NaOH rapid DNA extraction method. The innovative approach achieved rapid, real-time and accurate detection of three Avr genes in the field, which is helpful to understand the distribution frequency of the three Avr genes in the field and provide theoretical reference for the scientific layout of rice resistant varieties.

A novel vitrified cryopreservation approach with stem cell-laden hydrogel microcapsules

BACKGROUND

Stem cell-laden hydrogel microcapsules construction is important for a wide application in tissue engineering and cell-based medicine, such as building an ideal immune barrier. Challenges are emerging for effectively storing such microcapsules by cryopreservation, and a large proportion of research has been on the cryopreservation of single cells encapsulated into microcapsules without a core-shell structure.

OBJECTIVE

To achieve the effective cryopreservation of stem cell-laden hydrogel microcapsules with a core-shell structure.

MATERIALS AND METHODS

A novel core-shell alginate hydrogel encapsulation method was used to produce mesenchymal stem cell-laden microcapsules by microfluidic technique.

RESULTS

This microcapsule could inhibit ice formation to achieve vitreous cryopreservation with a low concentration (2 M) of penetrating cryoprotectants.

CONCLUSION

Cell laden hydrogel microcapsules may have the potential to be the basis of a new strategy of cell cryopreservation and applications. https://doi.org/10.54680/fr24210110212.

The Ras GTPase-activating protein UvGap1 orchestrates conidiogenesis and pathogenesis in the rice false smut fungus Ustilaginoidea virens

Ras GTPase-activating proteins (Ras GAPs) act as negative regulators for Ras proteins and are involved in various signalling processes that influence cellular functions. Here, the function of four Ras GAPs, UvGap1 to UvGap4, was identified and analysed in Ustilaginoidea virens, the causal agent of rice false smut disease. Disruption of UvGAP1 or UvGAP2 resulted in reduced mycelial growth and an increased percentage of larger or dumbbell-shaped conidia. Notably, the mutant ΔUvgap1 completely lost its pathogenicity. Compared to the wild-type strain, the mutants ΔUvgap1, ΔUvgap2 and ΔUvgap3 exhibited reduced tolerance to H2 O2 oxidative stress. In particular, the ΔUvgap1 mutant was barely able to grow on the H2 O2 plate, and UvGAP1 was found to influence the expression level of genes involved in reactive oxygen species synthesis and scavenging. The intracellular cAMP level in the ΔUvgap1 mutant was elevated, as UvGap1 plays an important role in maintaining the intracellular cAMP level by affecting the expression of phosphodiesterases, which are linked to cAMP degradation in U. virens. In a yeast two-hybrid assay, UvRas1 and UvRasGef (Ras guanyl nucleotide exchange factor) physically interacted with UvGap1. UvRas2 was identified as an interacting partner of UvGap1 through a bimolecular fluorescence complementation assay and affinity capture-mass spectrometry analysis. Taken together, these findings suggest that the UvGAP1-mediated Ras pathway is essential for the development and pathogenicity of U. virens.

[Research progress in molecular mechanism of palatal development]

Cleft palate is one of the most common maxillofacial birth defects, which can occur alone or accompany with many known deformities. Palatal selves need to complete the process of vertical growth, elevation, adhesion and fusion in a specific time window of embryo development. Any abnormality in this process will lead to cleft palate. Although previous studies have identified many molecular networks that regulate the growth, location and fusion of palatal selves, there are still many unknown mechanisms for palatal development. The pathogenesis of cleft palate has not been clarified so far. In recent years, the molecular research on palate development has been deepened continuously. Here we summarize major recent advances and integrate the genes and molecular pathways with the cellular and morphogenetic processes of palatal shelf growth, patterning, elevation, adhesion, and fusion, in order to comprehensively understand the genotype-phenotype functional relationship and provide assistance in formulating effective prevention strategies for cleft palate disease.

[Application value of CT examination of lymph node short diameter in evaluating cardia-left gastric lymph node metastasis in thoracic esophageal squamous cell carcinoma]

Objective: To investigate the application value of computed tomography (CT) examination of lymph node short diameter in evaluating cardia-left gastric lymph node metastasis in thoracic esophageal squamous cell carcinoma (ESCC). Methods: A total of 477 patients with primary thoracic ESCC who underwent surgical treatment in the Affiliated Cancer Hospital of Zhengzhou University from January 2013 to December 2017 were collected. All of them underwent McKeown esophagectomy plus complete two-field or three-field lymph node dissection. Picture archiving and communication system were used to measure the largest cardia-left gastric lymph node short diameter in preoperative CT images. The postoperative pathological diagnosis results of cardia-left gastric lymph node were used as the gold standard. Receiver operating characteristic (ROC) curve was used to evaluate the efficacy of CT lymph node short diameter in detecting the metastasis of cardia-left gastric lymph node in thoracic ESCC, and determine the optimal cut-off value. Results: The median short diameter of the largest cardia-left gastric lymph node was 4.1 mm in 477 patients, and the largest cardia-left gastric lymph node short diameter was less than 3 mm in 155 cases (32.5%). Sixty-eight patients had cardia-left gastric lymph node metastases, of which 38 had paracardial node metastases and 41 had left gastric node metastases. The lymph node ratios of paracardial node and left gastric node were 4.0% (60/1 511) and 3.3% (62/1 887), respectively. ROC curve analysis showed that the area under the curve of CT lymph node short diameter for evaluating cardia-left gastric lymph node metastasis was 0.941 (95% CI: 0.904-0.977; P<0.05). The optimal cut-off value of CT examination of the cardia-left gastric lymph node short diameter was 6 mm, and the corresponding sensitivity, specificity and accuracy were 85.3%, 91.7%, and 90.8%, respectively. Conclusion: CT examination of lymph node short diameter can be a good evaluation of cardia-left gastric lymph node metastasis in thoracic ESCC, and the optimal cut-off value is 6 mm.

Stereotactic Ablative Radiotherapy for the Treatment of Glandular Metastases from Renal Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Glandular metastases including pancreatic and adrenal sites of disease are associated with renal cell carcinoma (RCC) of indolent biology. Adrenal and pancreatic metastases may develop in isolation or involve other organs and are associated with prolonged survival. Glandular metastases can be treated with systemic therapy, stereotactic ablative radiotherapy (SAbR) or surgical resection and the optimal management of these patients is unknown. There is paucity of data on SAbR for RCC glandular metastases. We hypothesize that ablative doses of radiation therapy utilizing SAbR are associated with high rates of local control greater than 90%, with minimal or no acute grade 3 toxicities or higher with this approach. Here, we report local control (LC), progression-free survival (PFS), overall survival (OS) rates as well as toxicities related to SAbR for RCC metastases to the pancreatic and adrenal glands.

MATERIALS/METHODS

This IRB-approved, single-institution, retrospective study included patients with RCC metastases to the adrenal glands and pancreas treated with SAbR. Data on patient demographics, functional status, tumor characteristics, International Metastatic RCC Database Consortium (IMDC) risk category, local and systemic treatments, toxicities, and outcomes were collected and analyzed. RECIST 1.1 principals were utilized to determine LC rates and PFS. PFS was determined from the initiation of SAbR to progression (at SAbR-treated or other sites), or death. OS was defined from the start of SAbR to death. Two independent reviewers assessed these measures and analyzed patient electronic health records for toxicities using CTCAE v5 and relatedness scores.

RESULTS

A total of 50 RCC patients were included in this study with 36 adrenal and 20 pancreatic metastases treated with SAbR. Median dose fractionation used was 40 Gray delivered in 5 fractions. Sixteen patients (32%) were treatment naïve with oligometastatic disease, and thirty-four (68%) were oligo-progressive on systemic therapy with 1-3 prior lines of systemic therapy. For treated adrenal metastatic lesions at 1 year, patients demonstrated a 75.3% OS, 46.7% PFS, and LC of 93.3%. For treated pancreatic metastatic lesions at 1 year, patients demonstrated a 100% OS, 48.6% PFS, and LC of 100%. At 1 year, there was an OS of 82.2%, PFS of 48.2%, and LC of 95.9 % in the combined cohort. The percentage of patients experiencing an acute grade 2 or 3 toxicity attributed to adrenal or pancreatic gland SAbR was 7.4%. There were no acute grade >3 toxicities. The percentage of patients experiencing a late grade 2 or 3 toxicity was 9.3%. Median time to late adverse events was 37.4 months.

CONCLUSION

SAbR of RCC metastases to the pancreas and adrenal glands is feasible, safe and appears to be effective. Median PFS and OS in this cohort compared favorably to those reported in historical cohorts and is consistent with indolent disease.

Genome-Wide Prediction and Analysis of Oryza Species NRP Genes in Rice Blast Resistance

Members of the N-rich proteins (NRPs) gene family play important roles in the plant endoplasmic reticulum stress in response, which can be triggered by plant pathogens’ infection. Previous studies of the NRP gene family have been limited to only a few plants, such as soybean and Arabidopsis thaliana. Thus, their evolutionary characteristics in the Oryza species and biological functions in rice defense against the pathogenic fungus Magnaporthe oryzae have remained unexplored. In the present study, we demonstrated that the NRP genes family may have originated in the early stages of plant evolution, and that they have been strongly conserved during the evolution of the Oryza species. Domain organization of NRPs was found to be highly conserved within but not between subgroups. OsNRP1, an NRP gene in the Oryza sativa japonica group, was specifically up-regulated during the early stages of rice-M. oryzae interactions-inhibited M. oryzae infection. Predicted protein-protein interaction networks and transcription-factor binding sites revealed a candidate interactor, bZIP50, which may be involved in OsNRP1-mediated rice resistance against M. oryzae infection. Taken together, our results established a basis for future studies of the NRP gene family and provided molecular insights into rice immune responses to M. oryzae.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

A potato late blight resistance gene protects against multiple Phytophthora species by recognizing a broadly conserved RXLR-WY effector

Species of the genus Phytophthora, the plant killer, cause disease and reduce yields in many crop plants. Although many Resistance to Phytophthora infestans (Rpi) genes effective against potato late blight have been cloned, few have been cloned against other Phytophthora species. Most Rpi genes encode nucleotide-binding domain, leucine-rich repeat-containing (NLR) immune receptor proteins that recognize RXLR (Arg-X-Leu-Arg) effectors. However, whether NLR proteins can recognize RXLR effectors from multiple Phytophthora species has rarely been investigated. Here, we identified a new RXLR-WY effector AVRamr3 from P. infestans that is recognized by Rpi-amr3 from a wild Solanaceae species Solanum americanum. Rpi-amr3 associates with AVRamr3 in planta. AVRamr3 is broadly conserved in many different Phytophthora species, and the recognition of AVRamr3 homologs by Rpi-amr3 activates resistance against multiple Phytophthora pathogens, including the tobacco black shank disease and cacao black pod disease pathogens P. parasitica and P. palmivora. Rpi-amr3 is thus the first characterized resistance gene that acts against P. parasitica or P. palmivora. These findings suggest a novel path to redeploy known R genes against different important plant pathogens.

[Impact of multi-leaf collimator positioning accuracy on quality control of volumetric modulation arc therapy plan for cervical cancer treated with Elekta linear accelerator]

OBJECTIVE

To investigate the influence of positioning accuracy of the multi-leaf collimators (MLC) on the passing rate of the plan dose verification for volumetric modulation arc therapy (VMAT) of cervical cancer using an Elekta linear accelerator.

METHODS

The dose distributions were measured using Sun Nuclear's Mapcheck and Arccheck semiconductors matrix before and after MLC calibration in30 cervical cancer patients undergoing VMAT. Dosimetric comparisons were performed with 2D and 3D gamma passing rates of 3%, 3 mm and 2%, and 2 mm. The 3D gamma distribution was reconstructed with respect to the patient's anatomy using 3DVH software to evaluate the possible influence of MLC positioning accuracy.

RESULTS

Before and after MLC calibration, the gamma passing rates of Mapcheck were (88.80±1.81)% and (99.25 ± 0.53)% under 3% and 3 mm standard, respectively, with an average increase of 10.45%. The corresponding gamma passing rates of Arccheck were (87.61±1.98)% and (98.13±0.99)%, respectively, with an average increase of 10.52%. The gamma passing rates of 3DVH were (89.87±2.28)% and (98.3±1.15)%, respectively, with an average increase of 8.43%.

CONCLUSION

The MLC positioning accuracy is one of the main factors influencing dosimetric accuracy of VMAT for cervical cancer. The application of Autocal software facilitates MLC calibration and improves the accuracy and safety of VMAT delivery for cervical cancer.

The Velvet Protein UvVEA Regulates Conidiation and Chlamydospore Formation in Ustilaginoidea virens

Rice false smut, caused by Ustilaginoidea virens, is a serious disease of rice worldwide, severely reducing the quantity and quality of rice production. The conserved fungal velvet proteins are global regulators of diverse cellular processes. We identified and functionally characterized two velvet genes, UvVEA and UvVELB, in U. virens. The deletion of these genes affected the conidiation of U. virens but had no effect on the virulence of this pathogen. Interestingly, the ΔUvVEA mutants appeared in the form of smaller false smut balls with a reduced number of chlamydospores compared with the wide-type strains. In addition, the deletion of UvVEA affected the expression of some transmembrane transport genes during chlamydospore formation and rice false smut balls development. Furthermore, the ΔUvVEA mutants were shown to be defective in the utilization of glucose. These findings proved the regulatory mechanism underlying the formation of rice false smut balls and chlamydospores and provided a basis for the further exploration of the mechanism of these processes.

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort]

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

Identification of Differentially Expressed Genes Reveal Conserved Mechanisms in the Rice-Magnaporthe oryzae Interaction

Magnaporthe oryzae causes rice blast disease and is responsible for major losses in rice production worldwide. Although numerous studies have focused on the interactions between Oryza sativa and M. oryzae, to date, the conserved mechanisms remain in part unclear. In this study, a comparative analysis of transcriptomes of O. sativa L. ssp. japonica cv. 'Nipponbare' interacting with three M. oryzae strains (248, 235, and 163) were performed to explore the conserved molecular mechanisms. Differentially expressed genes with similar expression patterns in the interactions between cultivar 'Nipponbare' and three M. oryzae strains were defined as Conserved Differentially Expressed Genes (CDEGs). These included 3,647 O. sativa CDEGs and 3,655 M. oryzae CDEGs. Four rice CDEGs (LOC_Os03g19270, LOC_Os07g36600, LOC_Os05g28740, and LOC_Os01g32780) encoding universal stress protein (USP) were induced within 24 h post-inoculation (hpi) by three M. oryzae strains. Meanwhile, overexpression of LOC_Os07g36600 resulted in enhanced rice resistance against M. oryzae. Furthermore, four rice genes coding light-harvesting chlorophyll a/b-binding (LHC) protein (LOC_Os02g52650, LOC_Os09g12540, LOC_Os11g13850, LOC_Os05g22730) were also identified as CDEGs and were induced at 48 hpi, which might contribute to blast resistance through reactive oxygen species (ROS) accumulation. MoCDIP4 is M. oryzae effector inducing rice cell death and were verified that include AA9 CAZy domain (namely GH61 domain). In this study, we found seven MoCDIP4-homologous genes coding proteins with signal peptides and AA9 CAZy domains, which were continuously up-regulated across all infection stages relative to uninoculated control. This study uncovered that genes are required for conserved mechanisms of rice-M. oryzae interaction, which includes rice genes encoding USP proteins and LHC proteins, as well as M. oryzae genes encoding AA9 proteins. This study will help us to understand how O. sativa responds to M. oryzae infections and the molecular mechanisms of M. oryzae pathogenicity.

Loop-Mediated Isothermal Amplification for Rapid Detection of Mating Types of Villosiclava virens

Rice false smut (RFS), caused by Villosiclava virens, is an important fungal disease in panicles of rice. V. virens is a heterothallic ascomycete controlled by two opposite idiomorphs, MAT1-1 and MAT1-2. Previous study showed that sexual reproduction of V. virens plays an important role in the epidemic of RFS. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay to detect the mating type of V. virens easily and rapidly by using specific primers based on the mating type genes MAT1-1-2 and MAT1-2-1, respectively. The LAMP assay used only a water/dry bath and could recognize the mating type of V. virens in just 45 min. The LAMP assay was so sensitive that it could detect small amounts of V. virens genomic DNA (as low as 2.0 pg of MAT1-1 and 200.0 pg of MAT1-2) and was 10 times more sensitive than PCR. In addition, we demonstrated the application of mating type via LAMP assay by assessing the genomic DNA of V. virens isolated from rice fields. The high efficiency and specificity of this LAMP assay suggest that it can be used as a rapid testing tool in mating type recognition of V. virens isolates in the field.

[Progress in prevention and control of Nipah virus disease]

Nipah virus disease (NVD) is a newly emerged zoonosis with a case fatality rate of 40%-75%. NVD is a severe threat to human health and the development of livestock farming. NVD has become one of the emerging infectious diseases with great concern globally during more than 20 years. Nipah virus (NiV) is a pathogen for NVD, the natural host of which is Fruit bats of the Pteropodidae family. The clinical spectrum of NiV infection is broad, including asymptomatic infection, acute respiratory infection, fatal encephalitis, and even death. Since NiV was first identified in Malaysia in 1999, it has been prevalent mainly in Southeast Asia and South Asia. NiV is primarily transmitted to humans through bat-pig-human, contaminated food. Currently, there are no specific therapeutic drugs and vaccines for NVD. Although there are no cases of NVD reported in China, which has close personnel and trade exchanges with major NVD-endemic countries, and NiV antibody has also been detected in relevant bats. There is a potential risk of importing NVD and domestic outbreaks in the future in this country. This paper provides a systematic review of the research progress in the prevention and control of NVD etiology, epidemiology, clinical manifestations and laboratory diagnosis to help relevant staff to understand NVD more comprehensively and systematically.

Autophagy-related protein UvAtg7 contributes to mycelial growth, virulence, asexual reproduction and cell stress response in rice false smut fungus Ustilaginoidea virens

Autophagy is a conserved mechanism for nutrient and cytoplasmic components recycling in eukaryotic cell, in which E1-like enzyme Atg7 activates ubiquitin-like conjugation in the autophagy pathway. In plant pathogenic fungi Ustilaginoidea virens, UvAtg7, an ortholog of ATG7 in baker's yeast was identified and functionally investigated. UvAtg7 was confirmed to be essential for autophagy, because the disruption of UvATG7 gene in U. virens completely blocked the fusion of autophagosome-like into vacuoles and catalytic degradation of GFP-UvAtg8 under N-starving condition. The fluorescent signal indicated UvAtg7 protein was dispersed in cytoplasma, but spatially coordinated with core autophagy protein UvAtg8 on occasion. Interestingly, disruption of UvATG7 in U. virens caused slightly reduction in mycelial growth, but resulted in a considerable decrease in virulence, conidia production in YT broth and chlamydospore formation on rice false smut balls. Moreover, the UvATG7 deletion mutants exhibited increased sensitivity to cell wall integrity stress caused by congo red and calcofluor white , meanwhile the UvATG7 deletion mutants showed decreased sensitivity to osmotic stress, cell membrane stress and reactiveoxygen stress caused by sorbitol, sodium dodecyl sulfate and H₂O₂, respectively. All of these defects in UvATG7 deletion mutants could be partially or completely restored by gene complementation. In general, our study indicates that UvAtg7 is essential in autophagy pathway and contributes to mycelial growth, virulence, asexual reproduction and cell stress response in U. virens.

Vascular Anatomy of the Velopharyngeal Muscles and its Clinical Implications: A Fresh Cadaveric Study Based on Micro-computed Tomography

INTRODUCTION

Poor speech improvement after levator veli palatini (LVP) reconstruction may be related to intraoperative vascular injury. We aimed to examine the vascular anatomy of the velopharyngeal muscles to provide a guide for arterial protection in cleft palate repair.

MATERIALS AND METHODS

Fresh adult cadaveric heads were injected with gelatin/lead oxide. The velopharyngeal specimens were stained with iodine and scanned using micro-computed tomography. Three-dimensional reconstruction models were obtained using a computer-aided design software.

RESULTS

The ascending palatine artery (APaA), especially the posterior branch, is the main artery supplying the velopharyngeal muscles. The posterior branch of the APaA reaches the dorsal part of the musculus uvulae in the posterior one third of the soft palate (SP) and lies 1.75 mm (standard deviation, 0.06) under the nasal mucosa; the anterior branch penetrates the anterolateral side of the LVP to reach the anterior one third of the SP and lies 7.09 mm (0.03) under the oral mucosa. The posterior APaA, anterior ApaA, and ApaA trunk had mean diameters of 0.41 mm (0.04), 0.46 mm (0.06), and 0.65 mm (0.04) at 0.5 cm, 1 cm, and 1.5 cm distance from the palatal midline, respectively..

CONCLUSION

To minimize vascular injury, mobilization of muscles during intravelar veloplasty should be performed within a distance of 1 cm from the palatal midline, and dissection of the oral submucosa should be reduced in the anterior one third of the SP, while wide dissection of the nasal submucosal should be avoided in the posterior one third of the SP. This article is protected by copyright. All rights reserved.

[Analysis on characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive after discharge in Guangdong Province]

Objective: To analyze the epidemiological characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive in anal and/or throat swabs after discharge during the domestic imported epidemic stage in Guangdong Province in early 2020. Methods: The COVID-19 confirmed cases with the onset time before March 1, 2020 in Guangdong Province were collected to analyze the demographic data, epidemiological characteristics, and specimen collection and testing data after discharge. Logistic regression model was used for influencing factors analysis of re-positive cases. Results: A total of 1 286 COVID-19 confirmed cases were included, the M(Q₁,Q₃) of age was 44(32,58)years, 617 cases were male, 224 cases were re-positive in anal and/or throat swabs with the re-positive rate 17.42%. The M(Q₁,Q₃) of age of re-positive cases was 35(23, 50) years, which was younger than that of re-negative cases age was those 46(33, 59) years (P<0.001). With the increase of age, re-positive rate decreased (χ²_trend=52.73, P<0.001). 85.27% (191/224) of re-positive cases were found in 14 d after discharge, the duration time of re-positive status was 13(7, 24) d, and 81.69% (183/224) of re-positive cases were re-tested negative in 28 d after re-positive date. No fever and other symptoms had been observed among re-positive cases during the whole follow-up. No secondary infectious cases had been found among close contacts after 14 d of centralized isolation and sampling screening. Univariate logistic regression model analysis revealed that the influencing factors of the re-positive cases included age, occupation, clusters, clinical types, and admission time. Multivariate logistic regression model analysis revealed that age was an independent risk factor. Conclusions: SARS-CoV-2 viral nucleic acid re-positive is found in COVID-19 confirmed cases after discharge in Guangdong Province. Most re-positive cases are confirmed among 14 d after discharge and re-test to negative among 28 d after re-positive date. Age is an risk factor for re-positive cases after discharge.

Robust bulk micro-nano hierarchical copper structures possessing exceptional bactericidal efficacy

Conventional copper (Cu) metal surfaces are well recognized for their bactericidal properties. However, their slow bacteria-killing potency has historically excluded them as a rapid bactericidal material. We report the development of a robust bulk superhydrophilic micro-nano hierarchical Cu structure that possesses exceptional bactericidal efficacy. It resulted in a 4.41 log₁₀ reduction (>99.99%) of the deadly Staphylococcus aureus (S. aureus) bacteria within 2 min vs. a 1.49 log₁₀ reduction (96.75%) after 240 min on common Cu surfaces. The adhered cells exhibited extensive blebbing, loss of structural integrity and leakage of vital intracellular material, demonstrating the rapid efficacy of the micro-nano Cu structure in destructing bacteria membrane integrity. The mechanism was attributed to the synergistic degradation of the cell envelope through enhanced release and therefore uptake of the cytotoxic Cu ions and the adhesion-driven mechanical strain due to its rapid ultimate superhydrophilicity (contact angle drops to 0° in 0.18 s). The scalable fabrication of this micro-nano Cu structure was enabled by integrating bespoke precursor alloy design with microstructure preconditioning for dealloying and demonstrated on 2000 mm² Cu surfaces. This development paves the way to the practical exploitation of Cu as a low-cost antibiotic-free fast bactericidal material.

[Clinical efficacy of spinal cord stimulation for the patients with diabetic foot]

Objective: To observe the clinical efficacy of spinal cord stimulation (SCS) in the treatment of diabetic foot (DF). Methods: Sixteen patients who were diagnosed with DF and treated with SCS from the Department of Pain Medicine of the First Affiliated Hospital, China Medical University from October 2015 to October 2018 were retrospectively analyzed. Visual analogue scale (VAS), 36-item short form health survey (SF-36), transcutaneous oxygen partial pressure (TcPO₂) and skin temperature of lower limbs were compared before and after treatment, and the complications were recorded. Results: Among the 16 patients, 14 were equipped with implantable pulse generator (IPG). The VAS scores decreased significantly from 7.5±1.2 before treatment to 2.6±0.8, 2.0±0.7, 1.6±0.6, 1.0±0.9, 0.9±0.9 at 1 day, 1 week, 3 months, 6 months and 12 months after electrode implantation respectively (all P<0.05). At 12 months after treatment, the parameters of SF-36 were significantly different from those before treatment (all P<0.05). The TcPO₂ was (23±5) mmHg before treatment and (38±6) mmHg at 1 week after treatment, with a statistical difference (P<0.05), and the temperature of lower limbs increased significantly (P<0.05). No serious complications were observed in all patients. Conclusion: SCS can relieve the pain of patients with DF, improve the microcirculation and blood supply of lower limbs, and thus promote the quality of life, with rare serious complications.

[Observation on the curative effect of fibula transverse transport technique in the treatment of diabetic foot ulcer]

To investigate the clinical effect of fibula transverse transport technique in the treatment of diabetic foot ulcer. Nine patients (7 males and 2 females) with diabetic foot ulcer were treated with fibula transverse transport technique from September 2017 to September 2020. The mean age was (55±9) years (ranged from 43 to 66 years). In terms of Wagner classification, 2 cases were in grade 2, 5 cases were in grade 3, and the other 2 cases were in grade 4. All of the cases involved ischemic ulcers or ischemic-nerve ulcers. The transcutaneous oxygen pressure (TcPO₂) of the dorsal foot of the affected limb was measured, with the ulcer healing and TcPO₂ changes recorded at follow-up. All the 9 patients were followed up for (23±12) months (3 to 38 months). It was found that all patients with foot ulcers were cured within (4.2±1.9) months (2 to 8 months), and all the patients obtained limb salvage. Besides, there was no serious complications occurred, such as skin necrosis and needle tract infection. Before the operation, the TcPO₂ of the affected foot was (28.6±3.8) mmHg(1 mmHg=0.133 kPa), while it was (35.0±5.6) mmHg three months after operation (P<0.05). The technique of fibula transverse transport can effectively improve the microcirculation function of diabetic foot, and it can promote the healing of the ulcer with few complications.

SUN-Family Protein UvSUN1 Regulates the Development and Virulence of Ustilaginoidea virens

Ustilaginoidea virens, the causal agent of rice false smut disease, is an important plant pathogen that causes severe quantitative and qualitative losses in rice worldwide. UvSUN1 is the only member of Group-I SUN family proteins in U. virens. In this work, the role of UvSUN1 in different aspects of the U. virens biology was studied by phenotypic analysis of Uvsun1 knockout strains. We identified that UvSUN1 was expressed during both conidial germination and the infection of rice. Disruption of the Uvsun1 gene affected the hyphal growth, conidiation, morphology of hyphae and conidia, adhesion and virulence. We also found that UvSUN1 is involved in the production of toxic compounds, which are able to inhibit elongation of the germinated seeds. Moreover, RNA-seq data showed that knockout of Uvsun1 resulted in misregulation of a subset of genes involved in signal recognition and transduction system, glycometabolism, cell wall integrity, and secondary metabolism. Collectively, this study reveals that Uvsun1 is required for growth, cell wall integrity and pathogenicity of U. virens, thereby providing new insights into the function of SUN family proteins in the growth and pathogenesis of this pathogen.

Pyricularia sp. jiangsuensis, a new cryptic rice panicle blast pathogen from rice fields in Jiangsu Province, China

Pyricularia oryzae is a multi-host pathogen causing cereal disease, including the devastating rice blast. Panicle blast is a serious stage, leading to severe yield loss. Thirty-one isolates (average 4.1%) were collected from the rice panicle lesions at nine locations covering Jiangsu province from 2010 to 2017. These isolates were characterized as Pyricularia sp. jiangsuensis distinct from known Pyricularia species. The representative strain 18-2 can infect rice panicle, root and five kinds of grasses. Intriguingly, strain 18-2 can co-infect rice leaf with P. oryzae Guy11. The whole genome of P. sp. jiangsuensis 18-2 was sequenced. Nine effectors were distributed in translocation or inversion region, which may link to the rapid evolution of effectors. Twenty-one homologues of known blast-effectors were identified in strain 18-2, seven effectors including the homologues of SLP1, BAS2, BAS113, CDIP2/3, MoHEG16 and Avr-Pi54, were upregulated in the sample of inoculated panicle with strain 18-2 at 24 hpi compared with inoculation at 8 hpi. Our results provide evidences that P. sp. jiangsuensis represents an addition to the mycobiota of blast disease. This study advances our understanding of the pathogenicity of P. sp. jiangsuensis to hosts, which sheds new light on the adaptability in the co-evolution of pathogen and host.

The N-terminus of an Ustilaginoidea virens Ser-Thr-rich glycosylphosphatidylinositol-anchored protein elicits plant immunity as a MAMP

Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen.

Ustilaginoidea virens is a fungal pathogen that infects rice via the panicles. Here, the authors show that U. virens SGP1, a conserved Ser-Thr-rich glycosyl-phosphatidyl-inositol-anchored protein, elicits immune responses in rice leaves while contributing to virulence in panicles.