Radiomics using CT images for preoperative prediction of lymph node metastasis in perihilar cholangiocarcinoma: a multi-centric study.

OBJECTIVES: To develop a CT-based radiomics model for preoperative prediction of lymph node (LN) metastasis in perihilar cholangiocarcinoma (pCCA). METHODS: The study enrolled consecutive pCCA patients from three independent Chinese medical centers. The Boruta algorithm was applied to build the radiomics signature for the primary tumor and LN. The k-means algorithm was employed to cluster the selected LNs based on the radiomics signature LN. Support vector machines were used to construct the prediction models. The diagnostic efficiency was measured by the area under the receiver operating characteristic curve (AUC). The optimal model was evaluated in terms of calibration, clinical usefulness, and prognostic value. RESULTS: A total of 214 patients were included in the study (mean age: 61.6 years ± 9.4; 130 male). The selected LNs were classified into two clusters, which were significantly correlated with LN metastasis in all cohorts (p < 0.001). The model incorporated the clinical risk factors, radiomics signature primary tumor, and the LN cluster obtained the best discrimination, with AUC values of 0.981 (95% CI: 0.962-1), 0.896 (95% CI: 0.810-0.982), and 0.865 (95% CI: 0.768-0.961) in the training, internal validation, and external validation cohorts, respectively. High-risk patients predicted by the optimal model had shorter overall survival than low-risk patients (median, 13.7 vs. 27.3 months, p < 0.001). CONCLUSIONS: The study proposed a radiomics model with good performance to predict LN metastasis in pCCA. As a noninvasive preoperative prediction tool, this model may help in patient risk stratification and personalized treatment. CLINICAL RELEVANCE STATEMENT: A CT-based radiomics model accurately predicts lymph node metastasis in perihilar cholangiocarcinoma patients. This noninvasive preoperative tool can aid in patient risk stratification and personalized treatment, potentially improving patient outcomes. KEY POINTS: • The radiomics model based on contrast-enhanced CT is a useful tool for preoperative prediction of lymph node metastasis in perihilar cholangiocarcinoma. • Radiomics features extracted from lymph nodes show great potential for predicting lymph node metastasis. • The study is the first to identify a lymph node phenotype with a high probability of metastasis based on radiomics.

[Improve the Completion Rate of ECMO Placement Assistance for Nurses in the NICU].

BACKGROUND & PROBLEMS: The extracorporeal membrane oxygenation (ECMO) system can provide cardiopulmonary support to and reduce the mortality rate in severely ill newborns. According to our investigation, completion rate of the care process among staff nurses was only 63.5% in our ward. We assumed that the reasons for the above problems included: lack of care awareness, unfamiliarity with the ECMO operation process, inadequate instruments preparation, improper ECMO pipeline fixation, lack of designated space in the unit for placing ECMO supplies, lack of specialty care guidelines, lack of a regular inspection system, and lack of regular on-the-job education. PURPOSE: Improve awareness related to assisting ECMO placement among nurses in the neonatal intensive care unit and the completeness of care. RESOLUTIONS: 1. Create a care process guidebook describing the procedures for ECMO system placement in newborns to help nurse accomplish proper placement. 2. Establish the ECMO system consumables checklist and install an ECMO system-specialized toolbox to reduce the preparation time and smooth the process. 3. Regularly organize comprehensive nurse training and develop performance indicators to enhance ECMO system placement awareness and skills. RESULTS: The cognitive accuracy rate for the assisted placement of ECMO among nurses in the neonatal intensive care unit increased from 51.9% before improvement to 89.9% afterward. Also, the complete care rate of ECMO placement increased from 63.5% before improvement to 100% afterward. CONCLUSIONS: This project effectively improved the accuracy rate of nurses involved in assisting with ECMO placement, made the ECMO system placement process easier to implement, improved the care process completion rate, and improved newborn care quality.

Functional annotation of creeping bentgrass protein sequences based on convolutional neural network.

BACKGROUND: Creeping bentgrass (Agrostis soionifera) is a perennial grass of Gramineae, belonging to cold season turfgrass, but has poor disease resistance. Up to now, little is known about the induced systemic resistance (ISR) mechanism, especially the relevant functional proteins, which is important to disease resistance of turfgrass. Achieving more information of proteins of infected creeping bentgrass is helpful to understand the ISR mechanism. RESULTS: With BDO treatment, creeping bentgrass seedlings were grown, and the ISR response was induced by infecting Rhizoctonia solani. High-quality protein sequences of creeping bentgrass seedlings were obtained. Some of protein sequences were functionally annotated according to the database alignment while a large part of the obtained protein sequences was left non-annotated. To treat the non-annotated sequences, a prediction model based on convolutional neural network was established with the dataset from Uniport database in three domains to acquire good performance, especially the higher false positive control rate. With established model, the non-annotated protein sequences of creeping bentgrass were analyzed to annotate proteins relevant to disease-resistance response and signal transduction. CONCLUSIONS: The prediction model based on convolutional neural network was successfully applied to select good candidates of the proteins with functions relevant to the ISR mechanism from the protein sequences which cannot be annotated by database alignment. The waste of sequence data can be avoided, and research time and labor will be saved in further research of protein of creeping bentgrass by molecular biology technology. It also provides reference for other sequence analysis of turfgrass disease-resistance research.

Multi-Omics and Its Clinical Application in Hepatocellular Carcinoma: Current Progress and Future Opportunities.

Hepatocellular carcinoma (HCC) is the sixth most common malignancy and the fourth leading cause of cancer related death worldwide. China covers over half of cases, leading HCC to be a vital threaten to public health. Despite advances in diagnosis and treatments, high recurrence rate remains a major obstacle in HCC management. Multi-omics currently facilitates surveillance, precise diagnosis, and personalized treatment decision making in clinical setting. Non-invasive radiomics utilizes preoperative radiological imaging to reflect subtle pixel-level pattern changes that correlate to specific clinical outcomes. Radiomics has been widely used in histopathological diagnosis prediction, treatment response evaluation, and prognosis prediction. High-throughput sequencing and gene expression profiling enabled genomics and proteomics to identify distinct transcriptomic subclasses and recurrent genetic alterations in HCC, which would reveal the complex multistep process of the pathophysiology. The accumulation of big medical data and the development of artificial intelligence techniques are providing new insights for our better understanding of the mechanism of HCC via multi-omics, and show potential to convert surgical/intervention treatment into an antitumorigenic one, which would greatly advance precision medicine in HCC management.

Transcript Profiling and Gene Identification Involved in the Ethylene Signal Transduction Pathways of Creeping Bentgrass (Agrostis stolonifera) during ISR Response Induced by Butanediol.

Creeping bentgrass (Agrostis stolonifera) is the preferred green lawn grass, with excellent turf characteristics but poor disease resistance. At present, the mechanisms of disease resistance in creeping bentgrass are poorly understood, especially the ethylene signal transduction pathway under the induced systemic resistance (ISR) response. In this study, butanediol (BDO), as a new type of disease-resistance compound, was applied to creeping bentgrass seedlings to induce the ISR response. Then, we measured ethylene production and related enzyme activities. Additionally, transcript profiling and gene identification were performed in association to ethylene signal transduction pathways. The changes of ethylene production and related enzyme 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) and 1-aminocyclopropane-1-carboxylic acid synthases (ACS) activities showed significant difference at 24 h after Rhizoctonia solani inoculation among five treatments of various BDO concentrations. After 100 µmol L-1 BDO treatment, ethylene production and related enzyme activities reached their peak levels. Additionally, 208,672 unigenes of creeping bentgrass were obtained by de novo assembly. In total, 15,903 annotated unigenes were grouped into 33 canonical pathways in the KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. Among those, 1803 unigenes were classified as 'signal transduction'. There were 6766 differentially expressed genes (DEGs) among B24 (inoculated-rhizobacteria in MS medium with 100 µmol L-1 BDO for 24 h), NB24, B72 and NB24 (no rhizobacteria in MS medium with 100 µmol L-1 BDO for 24 h) libraries, and 4,639 DEGs between B24 and B72 (inoculated-rhizobacteria in MS medium with 100 µmol L-1 BDO for 72 h) libraries, with 4489 DEGs in all three libraries. As suggested by the RT-PCR assay, the expression levels of ethylene-responsive and defense-related genes were variable among treated samples during the BDO-induced ISR responses. The expression levels of EIN, ERF, NPR1, PR3 and PR4 genes increased and reached their peaks in the first 24 h after R. solani infection in the BDO-induced ISR reaction compared with NB24 treatments. This results is consistent with the changes of important ethylene biosynthetic enzymes and ethylene concentrations during the BDO-induced ISR responses. We further found the intermediate substances for the signaling pathway, and the relationships between the expression levels of BDO-induced ISR disease-resistance genes and those of the response genes for ethylene signal pathway. Our findings present a genetic basis for systemic resistance of creeping bentgrass through transcriptomic analysis and our study provides a theoretical and practical basis for the improvement of turfgrass disease resistance and quality.

MiR-3074-5p Regulates Trophoblasts Function via EIF2S1/GDF15 Pathway in Recurrent Miscarriage.

Dysfunction of extravillous trophoblasts (EVTs) might cause early pregnancy failure by interfering with embryo implantation and/or placentation. We previously reported that the villus miR-3074-5p expression level was increased, whereas the peripheral level of GDF15, a predict target gene of miR-3074-5p, was decreased in recurrent miscarriages (RM) patients, and miR-3074-5p could enhance apoptosis but reduce invasion of human extravillous trophoblast cells (EVTs). The aim of this study was to further explore roles of miR-3074-5p/GDF15 pathway in regulation of EVTs function. It was validated that GDF15 was not the direct target of miR-3074-5p, whereas EIF2S1, an upstream regulator of GDF15 maturation and secretion, was the direct target of miR-3074-5p. The villus expression levels of GDF15 and EIF2S1 were significantly decreased in RM patients. Knockdown of GDF15 expression presented inhibitory effects on proliferation, migration, and invasion of HTR8/SVneo cells. Up-regulated miR-3074-5p expression led to the significant decreased GDF15 expression in HTR8/SVneo cells, and this effect could be efficiently reversed by the overexpression of EIF2S1. Meanwhile, the suppressive effects of miR-3074-5p on proliferation, migration, and invasion of HTR8/SVneo cells could be intercepted by the treatment of recombinant human GDF15 protein. Collectively, these data suggested that miR-3074-5p could reduce GDF15 production via targeting inhibition of EIF2S1 expression, and the deficiency in GDF15 function might lead to the early pregnancy loss by attenuating proliferation and invasion of EVTs.

Calcium oscillation on homogeneous and heterogeneous networks of ryanodine receptor.

Calcium oscillation is an important calcium homeostasis, imbalance of which is the key mechanism of initiation and progression of many major diseases. The formation and maintenance of calcium homeostasis are closely related to the spatial distribution of calcium channels on endoplasmic reticulum, whose complex structure was unveiled by recent observations with superresolution imaging techniques. In the current paper, a theoretical framework is established by abstracting the spatial distribution of the calcium channels as a nonlinear biological complex network with calcium channels as nodes and Ca^{2+} as edges. A dynamical model for a ryanodine receptor (RyR) is adopted to investigate the effect of spatial distribution on calcium oscillation. The mean-field model can be well reproduced from the complete graph and dense Erdös-Rényi network. The synchronization of RyRs is found important to generate a global calcium oscillation. Below a critical density of the Erdös-Rényi or BaraBási-Albert network, the amplitude and interspike interval decrease rapidly with the end of disappearance of oscillation due to the desynchronization. The clique graph with a cluster structure cannot produce a global oscillation due to the failure of synchronization between clusters. A more realistic geometric network is constructed in a two-dimensional plane based on the experimental information about the RyR arrangement of clusters and the frequency distribution of cluster sizes. Different from the clique graph, the global oscillation can be generated with reasonable parameters on the geometric network. The simulation also suggests that existence of small clusters and rogue RyRs plays an important role in the maintenance of global calcium oscillation through keeping synchronization between large clusters. Such results support the heterogeneous distribution of RyRs with different-size clusters, which is helpful to understand recent observations with superresolution nanoscale imaging techniques. The current theoretical framework can also be extent to investigate other phenomena in calcium signal transduction.

Noninvasive imaging of hepatic dysfunction: A state-of-the-art review.

Hepatic dysfunction represents a wide spectrum of pathological changes, which can be frequently found in hepatitis, cholestasis, metabolic diseases, and focal liver lesions. As hepatic dysfunction is often clinically silent until advanced stages, there remains an unmet need to identify affected patients at early stages to enable individualized intervention which can improve prognosis. Passive liver function tests include biochemical parameters and clinical grading systems (e.g., the Child-Pugh score and Model for End-Stage Liver Disease score). Despite widely used and readily available, these approaches provide indirect and limited information regarding hepatic function. Dynamic quantitative tests of liver function are based on clearance capacity tests such as the indocyanine green (ICG) clearance test. However, controversial results have been reported for the ICG clearance test in relation with clinical outcome and the accuracy is easily affected by various factors. Imaging techniques, including ultrasound, computed tomography, and magnetic resonance imaging, allow morphological and functional assessment of the entire hepatobiliary system, hence demonstrating great potential in evaluating hepatic dysfunction noninvasively. In this article, we provide a state-of-the-art summary of noninvasive imaging modalities for hepatic dysfunction assessment along the pathophysiological track, with special emphasis on the imaging modality comparison and selection for each clinical scenario.

The Research Progress of Bufalin in the Treatment of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world with a five-year survival rate of less than 20%. Nonetheless, selecting an appropriate therapeutic agent to inhibit the development of hepatoma cells is still a challenge. Bufalin, a component of the traditional Chinese medicine Chansu, has been shown to inhibit the proliferation, invasion and metastasis of HCC through various signaling pathways. In addition, bufalin and sorafenib demonstrate a synergistic effect in cancer therapeutics. This review highlighted on several focal signaling pathways involved in the inhibitory effects of bufalin on HCC and its synergistic mechanisms with sorafenib. The immunotherapy effect of bufalin has also been discussed as a novel property.

Radiomics in hepatocellular carcinoma: A state-of-the-art review.

Hepatocellular carcinoma (HCC) is the most common cancer and the second major contributor to cancer-related mortality. Radiomics, a burgeoning technology that can provide invisible high-dimensional quantitative and mineable data derived from routine-acquired images, has enormous potential for HCC management from diagnosis to prognosis as well as providing contributions to the rapidly developing deep learning methodology. This article aims to review the radiomics approach and its current state-of-the-art clinical application scenario in HCC. The limitations, challenges, and thoughts on future directions are also summarized.

Role of noninvasive imaging in the evaluation of intrahepatic cholangiocarcinoma: from diagnosis and prognosis to treatment response.

INTRODUCTION: Intrahepatic cholangiocarcinoma is the second most common liver cancer. Desmoplastic stroma may be revealed as distinctive histopathologic findings favoring intrahepatic cholangiocarcinoma. Meanwhile, a range of imaging manifestations is often accompanied with rich desmoplastic stroma in intrahepatic cholangiocarcinoma, which can indicate large bile duct ICC, and a higher level of cancer-associated fibroblasts with poor prognosis and weak treatment response. AREAS COVERED: We provide a comprehensive review of current state-of-the-art and recent advances in the imaging evaluation for diagnosis, staging, prognosis and treatment response of intrahepatic cholangiocarcinoma. In addition, we discuss precursor lesions, cells of origin, molecular mutation, which would cause the different histological classification. Moreover, histological classification and tumor microenvironment, which are related to the proportion of desmoplastic stroma with many imaging manifestations, would be also discussed. EXPERT OPINION: The diagnosis, prognosis, treatment response of intrahepatic cholangiocarcinoma may be revealed as the presence and the proportion of desmoplastic stroma with a range of imaging manifestations. With the utility of radiomics and artificial intelligence, imaging is helpful for ICC evaluation. Multicentre, large-scale, prospective studies with external validation are in need to develop comprehensive prediction models based on clinical data, imaging findings, genetic parameters, molecular, metabolic, and immune biomarkers.

Two-dimensional shear wave elastography for significant liver fibrosis in patients with chronic hepatitis B: A systematic review and meta-analysis.

PURPOSE: To determine the diagnostic performance and cutoff value of two-dimensional shear wave elastography (2D SWE) for detecting significant liver fibrosis in patients with chronic hepatitis B (CHB). METHODS: A systematic literature search of the PubMed, EMBASE, Cochrane Library databases and Web of Science was conducted. Bivariate modelling and summary receiver-operating-characteristic (ROC) modelling were constructed to summarize the diagnostic performance of 2D SWE. Meta-regression analyses were performed to explore the source of heterogeneity. RESULTS: Eleven eligible studies with 2623 patients were included. 2D SWE showed a summary sensitivity of 88 % (95 % CI: 83-91), specificity of 83 % (95 % CI: 78-88) and area under the ROC curve of 0.92 (95 % CI: 0.89-0.94) for detecting significant fibrosis in CHB patients. The mean threshold of 2D SWE was 7.91 kPa (range: 6.73-10.00 kPa). Notably, the cutoffs of studies excluding patients with history of prior antiviral therapy were generally lower than that of studies without excluding those who had received antiviral treatment, with an average of 7.15 kPa and 8.87 kPa, respectively (p < 0.01). Meta-regression analysis revealed that enrollment of consecutive patients was the only significant factor influencing heterogeneity (p < 0.01). Specifically, studies recruiting consecutive patients with CHB had significantly lower sensitivity than those with absence of consecutive enrolment (0.83 vs 0.92, p < 0.01). CONCLUSIONS: 2D SWE is an excellent modality for predicting significant liver fibrosis in CHB populations. Further work is required to establish the cutoffs that account for antiviral treatment as a potential confounding factor.

Sinusoidal obstruction syndrome: A systematic review of etiologies, clinical symptoms, and magnetic resonance imaging features.

BACKGROUND: Sinusoidal obstruction syndrome (SOS) is a kind of rare liver disease which is characterized by damage to small hepatic vessels, affecting particularly the sinusoidal endothelium. Due to the special etiology and high mortality, early diagnosis of SOS is significant for clinical survival and prognosis. AIM: To generalize the common etiologies and clinical symptoms of SOS and summarize the characteristic magnetic resonance imaging (MRI) features so as to provide more valuable information for early diagnosis of SOS. METHOD: We searched PubMed, Web of science, Wanfang Data, China Knowledge Resource Integrated, VIP, and Cochrane Library databases without a limiting period and the types of articles. The search process mainly revolved around the etiologies, common clinical symptoms, and MRI imaging features of SOS. Ultimately, 29 full articles were included in this review and 222 articles were excluded. RESULTS: Eleven case reports included 13 patients. The etiologies of these patients including chemotherapy (5/13), medicinal herbs containing pyrrolidine alkaloids (PAs, e.g. Tusanqi) (4/13), hematopoietic stem cell transplantation (HSCT) (2/13), drug toxicity (6-thioguanine) (1/13), and "poppers", a recreational drug used during anal intercourse (1/13). Eighteen case series including 497 patients, and SOS in 465 (93.6%) patients was caused by PAs. Ascites, abdominal pain and swelling, jaundice were the most common clinical symptoms. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), total bilirubin (TBil), direct bilirubin (DBil), and prothrombin time (PT) had varying degrees of elevation. Heterogeneous signals on T1 weighted imaging/T2 weighted imaging (T1WI/T2WI), heterogeneous enhancement of liver parenchyma, ascites, hepatomegaly, narrowing and blurring of intrahepatic inferior vena cava and three main hepatic veins, edema around the portal vein, and gallbladder wall edema were the most common MRI imaging features of SOS. CONCLUSION: In the West, SOS was mostly secondary to HSCT. Some SOS developed in the process of chemotherapy for hepatic metastatic tumor. A few SOS were caused by toxicity of certain drugs. In the East, Tusanqi was a major cause of SOS. Ascites, abdominal pain and swelling, jaundice were the common clinical symptoms. Elevations of ALT, AST, GGT, ALP, TBil, and DBil could be used as predictors of liver function damage. Numerous characteristic MRI imaging features could provide more valuable information for early diagnosis of SOS.

Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy?

BACKGROUND: The Liver Imaging Reporting and Data System (LI-RADS), supported by the American College of Radiology (ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma (HCC). Diffusion-weighted imaging (DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging (MRI) for HCC. AIM: To determine whether the use of DWI can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC. METHODS: In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity (SE), specificity (SP), accuracy (AC), positive predictive value (PPV), and negative predictive value (NPV) of LI-RADS were calculated. Youden index values were used to compare the diagnostic performance of LI-RADS with or without DWI. RESULTS: Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS (kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and 71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and 75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR- 4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%, 75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647. CONCLUSION: LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.

Noninvasive imaging of hepatocellular carcinoma: From diagnosis to prognosis.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Hepatocarcinogenesis is a complex multistep process at molecular, cellular, and histologic levels with key alterations that can be revealed by noninvasive imaging modalities. Therefore, imaging techniques play pivotal roles in the detection, characterization, staging, surveillance, and prognosis evaluation of HCC. Currently, ultrasound is the first-line imaging modality for screening and surveillance purposes. While based on conclusive enhancement patterns comprising arterial phase hyperenhancement and portal venous and/or delayed phase wash-out, contrast enhanced dynamic computed tomography and magnetic resonance imaging (MRI) are the diagnostic tools for HCC without requirements for histopathologic confirmation. Functional MRI techniques, including diffusion-weighted imaging, MRI with hepatobiliary contrast agents, perfusion imaging, and magnetic resonance elastography, show promise in providing further important information regarding tumor biological behaviors. In addition, evaluation of tumor imaging characteristics, including nodule size, margin, number, vascular invasion, and growth patterns, allows preoperative prediction of tumor microvascular invasion and patient prognosis. Therefore, the aim of this article is to review the current state-of-the-art and recent advances in the comprehensive noninvasive imaging evaluation of HCC. We also provide the basic key concepts of HCC development and an overview of the current practice guidelines.

[SEM observation on leaf epidermis of different Ephedra species].

OBJECTIVE: Characters of stem epidermis, leaf epidermis and stoma could be used as important microcosmic morphological characteristic when inheritance trend is studied in Ephedra breeding and identification. METHOD: The stomatic density, stoma major axis and mimor axis, stomatic morphylogy, characters of leaf and stem epidermis of 6 Ephedra plants' stems were examined by SEM. RESULT: The stomatic density and characteristic of leaf epidermis and stem epidermis in six Ephedra species was differenc, there were no obvious morphological differences in stoma shape and size. The guard cells were covered with heavy cuticle and sunken stomata, which were the typical characteristics of xerophytes. The stomas of leaf lower epidermis were oblong or hexagon, but the stomas of steam epidermis were narrowed-oblong or dumbbell-shape, they all belonged to anomalous type. CONCLUSION: The stoma type and characters of Ephedra plants is stable and conservative, there was no obvious morphological differences in stoma shape and size between species, so it is difficult to distinguish different species by the variance of stomas, but that can be applyed to distinguish Ephedra from others at plant taxonomy.