First report of root rot caused by Fusarium commune on American ginseng (Panax quinquefolium L.) in China.

American ginseng (Panax quinquefolium L.) is one of the most valuable herb crops because of its unique pharmacological effects. In 2019, American ginseng plants withered and root rot with incidences of 20-45% were observed in about 70000m2 of ginseng production field located in mountainous valley of Benxi city (41º23'32" N, 124º04'27" E), Liaoning Province in China. Disease symptoms included chlorotic leaves with dark brown discoloration extending gradually from the basal to the apical part of the leaves. Water-soaked, irregular lesions appeared on the surface of roots and rotten at later stage. Twenty-five symptomatic roots were surface-sterilized by immersion in 2% sodium hypochlorite (NaOCl) for 3 min, followed by rinsing three times in sterilized water. The sections healthy tissues bordered rotten tissues, i.e. the leading edge, were cut into 4-5 mm pieces with a sterile scalpel and 4 pieces were placed on each PDA plate. After 5 days incubation at 26°C, total of 68 single spores were obtained from the colonies with an inoculation needle under stereomicroscope. Colonies from single conidia were white to greyish white, densely floccose to fluffy, and the reverse grayish yellow with dull violet pigmentation. Single-celled and ovoid microconidia in false heads were borne on aerial monophialidic or polyphialidic conidiophores on Carnation Leaf Agar (CLA) media, and measured 5.0 -14.5 × 3.0 -4.8 µm (n=25). Macroconidia were two to four septa, slightly curved, apical and basal cells were also curved, and they measured 22.5 - 45.5 × 4.5 - 6.3 µm (n=25). Chlamydospores were singly or in pairs, circular or subcircular, smooth, and measuring 5 - 10.5 µm (n=25) in diameter. Morphologically, the isolates were identified as Fusarium commune (Skovgaard et al. 2003; Leslie and Summerell 2006 ). To confirm the identity, the rDNA partial translation elongation factor1 alpha (TEF-a) gene and the internal transcribed spacer (ITS) region of ten isolates were amplified and sequenced (O'Donnell et al. 2015; White et al. 1990). Identical sequences were obtained, and one representative sequence of isolate BGL68 was submitted to GenBank. BLASTn analysis of both the TEF-α (MW589548) and the ITS (MW584396) sequences, revealed 100% and 99.46 % sequence identity to F. commune MZ416741 and KU341322, respectively. The pathogenicity test was conducted under greenhouse conditions. The surface of healthy 2-year-old American ginseng roots was washed and disinfested in 2% NaOCl for 3 min before rinsing in sterilized water. Twenty roots were wounded with a toothpick, resulting in tiny perforations (1.0 × 1.0×3.0 mm), 3 perforations were wounded on each root. Inoculums was prepared from the culture of isolate BGL68 incubate in potato dextrose broth (PD) for 5 days at 26°C,140 rpm. Ten wounded roots were immersed in a conidial suspension (2 × 105 conidia/ml) for four hours in a plastic bucket, and planted in five containers (two roots per container) filled with sterile soil. Another ten wounded roots were immersed in sterilized distilled water and planted in five containers as controls. The containers were incubated for four weeks in a greenhouse at temperature between 23°C and 26°C, under a 12-hr light and dark regime, and irrigate with sterile water every 4 days. Three weeks after inoculation, all inoculated plants exhibited chlorotic leaves, wilting and root rot. The taproot and the fibrous roots showed brown to black root rot and no symptoms in non-inoculated controls. The fungus was reisolated from the inoculated plants, but not from any of the control plants. The experiment was repeated two times with similar results. This is the first report of root rot caused by F. commune on American ginseng in China. The disease might bring a threat to this ginseng production and should be implemented effective control measures to reduce losses.

First report of Fusarium oxysporum causing root rot of Gentiana scabra bunge (Adenophora capillaris) in China.

Gentiana scabra bunge (Adenophora capillaris) is a traditional Chinese medicine crop in the northeast China. In July 2019, the root rot symptoms of A. capillaris were observed in its production field (approximately 1.3 hectares) iningyuan Manchu Autonomous County (41º47'28" N, 124º21'35" E), Fushun City in Liaoning province, China. Typical symptom included wilting, darkening, and rotting of the root collar and vascular bundle, leading to plant defoliation and death. Approximately 25% of the plants in the field showed the symptoms, with 2-year-old plants having more severe symptoms. Root tissue samples were collected from the diseased plants, surface-sterilized with 75% ethanol for 30 s, followed by 2% NaClO for 5 min, rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). After 3 days of incubation at 25 °C, white Fusarium-like colonies grew out from the symptomatic root tissue pieces. Five single-spore isolates were obtained from 10-day-old cultures using single-spore isolating technique. The fungus produced many macroconidia with the typical macroconidia of Fusarium spp. on carnation leaf agar (CLA) after 18 days of incubation at 26°C. They were falculate, slender and slightly curved, and their cells at both ends were sharp. Macroconidia had 3 to 5 septa, measuring 24.8 to 48.6 × 3.5 to 6.4 µm (n=50). Microconidia had 1 to 2 septa, elliptical, rounded tip, measuring 6.7 to 22.5 × 2.4 to 5.5 µm (n=5). Morphologically, the isolates were identified as Fusarium oxysporum (Leslie and Summerell 2006). For molecular identification, the internal transcribed spacer (ITS) region of rDNA and the translation elongation factor-1a (TEF-1α) of Isolate LD528-1 were amplified with the general primer ITS1/ITS4 and TEF-1α primer EF-1/EF-2 (O'Donnell et al. 1998). The resulting sequences were deposited in GenBank (acc. nos. MW418098 and MW423622). BLASTn analysis of the ITS sequence (KU939043) and TEF sequence (MW423622) revealed 99.06% sequence identity with F. oxysporum (KU939043) and 100% with F. oxysporum (MN892354), respectively. For pathogenicity test, a pot experiment was conducted in a greenhouse with 22 to 28°C and 65 to 90% relative humidity. Roots of A. capillaris were dipped in a spore suspension (1×107 conidia/ml) of Isolate LD528-1 for approximately 5 min, and then planted into the pots filled with sterilized field soil. Root dipped in sterilized water served as the controls. There were five pots for the inoculation treatment and three pots for the control treatment. All treated pots were placed and maintained in the greenhouse. After 15 days, 80% of inoculated plants were infected, with the symptoms similar to those observed in the field. The plants in the control treatment did not develop any symptoms. The same fungus was re-isolated from the diseased root tissue and confirmed by morphological and molecular assays as described above. This is the first report of F. oxysporum causing root rot of gentiana scabra bunge in China. This disease can become one of most important diseases in gentiana scabra bunge in China. References: Leslie, J. F., and Summerell, B. A. 2006. The Fusarium Laboratory Manual. Blackwell Publishing Ltd, Iowa, USA. O'Donnell, K., et al. 1998.PNAS, 95:2044. Funding: This work was supported by the Grant of China Agriculture Research System (CARS-21-06).

Automatic machine learning based on native T1 mapping can identify myocardial fibrosis in patients with hypertrophic cardiomyopathy.

OBJECTIVES: To investigate the feasibility of automatic machine learning (autoML) based on native T1 mapping to predict late gadolinium enhancement (LGE) status in hypertrophic cardiomyopathy (HCM). METHODS: Ninety-one HCM patients and 44 healthy controls who underwent cardiovascular MRI were enrolled. The native T1 maps of HCM patients were classified as LGE ( +) or LGE (-) based on location-matched LGE images. An autoML pipeline was implemented using the tree-based pipeline optimization tool (TPOT) for 3 binary classifications: LGE ( +) and LGE (-), LGE (-) and control, and HCM and control. TPOT modeling was repeated 10 times to obtain the optimal model for each classification. The diagnostic performance of the best models by slice and by case was evaluated using sensitivity, specificity, accuracy, and microaveraged area under the curve (AUC). RESULTS: Ten prediction models were generated by TPOT for each of the 3 binary classifications. The diagnostic accuracy obtained with the best pipeline in detecting LGE status in the testing cohort of HCM patients was 0.80 by slice and 0.79 by case. In addition, the TPOT model also showed discriminability between LGE (-) patients and control (accuracy: 0.77 by slice; 0.78 by case) and for all HCM patients and controls (accuracy: 0.88 for both). CONCLUSIONS: Native T1 map analysis based on autoML correlates with LGE ( +) or (-) status. The TPOT machine learning algorithm could be a promising method for predicting myocardial fibrosis, as reflected by the presence of LGE in HCM patients without the need for late contrast-enhanced MRI sequences. KEY POINTS: • The tree-based pipeline optimization tool (TPOT) is a machine learning algorithm that could help predict late gadolinium enhancement (LGE) status in patients with hypertrophic cardiomyopathy. • The TPOT could serve as an adjuvant method to detect LGE by using information from native T1 maps, thus avoiding the need for contrast agent. • The TPOT also detects native T1 map alterations in LGE-negative patients with hypertrophic cardiomyopathy.

[Two types of exercise-induced abnormal blood pressure response in hypertrophic cardiomyopathy].

Objective: Insufcient exercise blood pressure response(blunted ABPR) and lower blood pressure during the recovery period (LBP)after exercise are common abnormalities in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to analyze the related factors of these two types of abnormal blood pressure response in HCM patients and their relationship with cardiopulmonary function. Methods: A total of 219 consecutive HCM patients who underwent CPET in Fuwai hospital were recruited from April 1, 2018 to Jan 31, 2020 with a complete clinical assessment, including electrocardiography, HOLTER, rest echocardiography and cardiac MRI. One hundred and eleven healthy age- and gender-matched volunteers enrolled as control group. Results: The incidences of blunted ABPR and LBP in HCM patients were much higher than normal control group (8.7% vs 1.8%, P=0.016; 6.8% vs 0.0%, P=0.003, respectively). In HCM group, patients with blunted ABPR combined more coronary artery disease (CAD) (P=0.029), pulmonary hypertension (PH) (P=0.002) and atrial fibrillation/flutter (P=0.036) compared with patients without blunted ABPR. Compared with HCM patients without LBP, the patients with LBP had higher rest left ventricular outflow tract (LVOT) gradient (P=0.017) and left ventricular ejection fraction (P=0.043), more incidence of LVOT obstructive (P=0.015) and systolic anterior motion (P=0.022). After Logistic regression analysis, CAD and PH were independent factor of blunted ABPR, while LBP was only independently associated with rest LVOT gradient. Blunted ABPR was associated with lower Peak VO2, peak heart rate and hear rate reserve, and higher NT-proBNP (P=0.019), VE/VO2 (P=0.000). LBP was not associated with any index of cardiopulmonary function. Conclusion: The incidences of blunted ABPR and LBP in HCM patients were much higher than normal control group. In HCM patients, CAD and PH were independent determinants of blunted ABPR, while LBP was only independently associated with rest LVOT gradient. Patients with blunted ABPR had lower cardiopulmonary function, but LBP was not associated cardiopulmonary function.

[Early Assessment of Myocardial Fibrosis of Hypertrophic Cardiomyopathy with Native-T1-Mapping-Based Deep Learning: A Preliminary Study].

OBJECTIVE: To explore the diagnostic performance of deep learning (DL) model in early detection of the interstitial myocardial fibrosis using native T1 maps of hypertrophic cardiomyopathy (HCM) without late gadolinium enhancement (LGE). METHODS: Sixty HCM patients and 44 healthy volunteers who underwent cardiac magnetic resonance were enrolled in this study. Each native T1 map was labeled according to its LGE status. Then, native T1 maps of LGE (-) and those of the controls were preprocessed and entered in the SE-ResNext-50 model as the matrix for the DL model for training, validation and testing. RESULTS: A total of 241 native T1 maps were entered in the SE-ResNext-50 model. The model achieved a specificity of 0.87, sensitivity of 0.79, and area under curve ( AUC) of 0.83 ( P<0.05) in distinguishing native T1 maps of LGE (-) from those of the controls in the testing set. CONCLUSION: The DL model based on SE-ResNext-50 could be used for identifying native T1 maps of LGE (-) with relatively high accuracy. It is a promising approach for early detection of myocardial fibrosis in HCM without the use of contrast agent.

Prognostic Value of Feature-Tracking Circumferential Strain in Dilated Cardiomyopathy Patients with Severely Reduced Ejection Fraction Incremental to Late Gadolinium Enhancement.

Myocardial fiber deformation measurements have been reported to be associated with adverse outcomes in patients with acute heart failure and those with myocardial infarction. However, few studies have addressed the prognostic value of global circumferential strain (GCS) in dilated cardiomyopathy (DCM) patients with severely impaired systolic function. This study aimed to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived GCS in DCM patients with severely reduced ejection. Consecutive DCM patients with severely reduced ejection fraction (EF <35%) who underwent CMR were included. GCS was calculated from CMR cine images. The clinical endpoint was a composite of all-cause mortality, heart transplantation, implantable cardioverter defibrillator (ICD) implantation and aborted sudden cardiac death (SCD). A total of 129 patients with a mean EF of 15.33% (11.36%-22.27%) were included. During a median follow-up of 518 days, endpoint events occurred in 50 patients. Patients with GCS ≥ the median (-5.17%) had significantly reduced event-free survival as compared with those with GCS < the median (P<0.01). GCS was independently associated with adverse events after adjusting for clinical and imaging risk factors including extent of late gadolinium enhancement (LGE) (P<0.05). Adding GCS into the model including the extent of LGE resulted in significant improvements in the C-statistic (from 0.706 to 0.742; P<0.05) with a continuous net reclassification improvement (NRI) of 29.71%. It was concluded that GCS derived from CMR could be useful for risk stratification in DCM patients with severely reduced EF, which may increase common imaging risk factors including LGE.

Author Correction: Distribution pattern of leftventricular myocardial strain analyzed by a cine MRI based deformation registration algorithm in healthy Chinese volunteers.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cardiovascular magnetic resonance evidence of myocardial fibrosis and its clinical significance in adolescent and adult patients with Ebstein's anomaly.

BACKGROUND: Myocardial fibrosis is a common pathophysiological process that is related to ventricular remodeling in congenital heart disease. However, the presence, characteristics, and clinical significance of myocardial fibrosis in Ebstein's anomaly have not been fully investigated. This study aimed to evaluate myocardial fibrosis using cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) and T1 mapping techniques, and to explore the significance of myocardial fibrosis in adolescent and adult patients with Ebstein's anomaly. METHODS: Forty-four consecutive patients with unrepaired Ebstein's anomaly (34.0 ± 16.2 years; 18 males), and an equal number of age- and gender-matched controls, were included. A comprehensive CMR protocol consisted of cine, LGE, and T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequences were performed. Ventricular functional parameters, native T1, extracellular volume (ECV), and LGE were analyzed. Associations between myocardial fibrosis and disease severity, ventricular function, and NYHA classification were analyzed. RESULTS: LGE was found in 10 (22.7%) patients. Typical LGE in Ebstein's anomaly was located in the endocardium of the septum within the right ventricle (RV). The LV ECV of Ebstein's anomaly were significantly higher than those of the controls (30.0 ± 3.8% vs. 25.3 ± 2.3%, P < 0.001). An increased ECV was found to be independent of the existence of LGE. Positive LGE or higher ECV (≥30%) was associated with larger fRV volume, aRV volume, increased disease severity, and worse NYHA functional class. In addition, ECV was significantly correlated with the LV ejection fraction (P <  0.001). CONCLUSIONS: Both focal and diffuse myocardial fibrosis were observed in adolescent and adult patients with Ebstein's anomaly. Increased diffuse fibrosis is associated with worse LV function, increased Ebstein's severity, and worse clinical status.

Distribution pattern of left-ventricular myocardial strain analyzed by a cine MRI based deformation registration algorithm in healthy Chinese volunteers.

The cine magnetic resonance imaging based technique feature tracking-cardiac magnetic resonance (FT-CMR) is emerging as a novel, simple and robust method to evaluate myocardial strain. We investigated the distribution characteristics of left-ventricular myocardial strain using a novel cine MRI based deformation registration algorithm (DRA) in a cohort of healthy Chinese subjects. A total of 130 healthy Chinese subjects were enrolled. Three components of orthogonal strain (radial, circumferential, longitudinal) of the left ventricle were analyzed using DRA on steady-state free precession cine sequence images. A distinct transmural circumferential strain gradient was observed in the left ventricle that showed universal increment from the epicardial to endocardial myocardial wall (epiwall: -15.4 ± 1.9%; midwall: -18.8 ± 2.0%; endowall: -22.3 ± 2.3%, P < 0.001). Longitudinal strain showed a similar trend from epicardial to endocardial layers (epiwall: -16.0 ± 2.9%; midwall: -15.6 ± 2.7%; endowall: -14.8 ± 2.4%, P < 0.001), but radial strain had a very heterogeneous distribution and variation. In the longitudinal direction from the base to the apex of the left ventricle, there was a trend of decreasing peak systolic longitudinal strain (basal: -23.3 ± 4.6%; mid: -13.7 ± 7.3%; apical: -13.2 ± 5.5%; P < 0.001). In conclusion, there are distinct distribution patterns of circumferential and longitudinal strain within the left ventricle in healthy Chinese subjects. These distribution patterns of strain may provide unique profiles for further study in different types of myocardial disease.

[Reference Values for Left Ventricular Myocardial Strains Measured by Feature-tracking Magnetic Resonance Imaging in Chinese Han Population].

OBJECTIVES: To establish reference values for left ventricular (LV) myocardial strains in a cohort of healthy Chinese volunteers with feature tracking cardiac magnetic resonance imaging. METHODS: A total of 60 healthy volunteers were recruited, receiving a cardiac magnetic resonance imaging (CMR) examination at 3.0T scanner (Tim Trio, Magnetum, Siemens, Germany). A new feature tracking CMR software (Trufisp-strain, Siemens) was used to analyze left ventricular myocardial strain parameters, including radial, circumferential, longitudinal strain, systolic strain rate, and early diastolic strain rate. RESULTS: The image quality was sufficient to perform strain analysis.The reference values of global strain, global strain rate and segmental strains were obtained. A good inter- and intra-observer agreement was achieved in global strain analysis (except circumferential straininter-observer in apical level), with (37.7±9.6)% for LV global mean radial strain, (-18.4±3.3)% for circumferential strain and (-15.2±2.3%) for longitudinal strain, respectively.Age was positively correlated with global mean radial strain ( r=0.416, P<0.001) and negatively correlated with early diastolic strain rate (circumferential or longitudinal) and circumferential strain( r=-0.436, P<0.001; r=-0.326, P=0.011; r=-0.273, P=0.035, respectively). Women showed higher circumferential and longituinal strain values and lower systolic circumferential strain rate than men. The strain parameters were correlated with left ventricular ejection fraction (LVEF) ( P<0.05). CONCLUSIONS: FT-CMR (Trufisp-strain software) is a fast, convenient and highly reproducible method for analyzing left ventricular myocardial strains, which can sensitively detect gender and age differences. The reference values of LV myocardial strains can support further studies in the future.