Potential therapeutic option for EGFR-mutant small cell lung cancer transformation: a case report and literature review.

Transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is rare and is associated with poor prognosis. However, the standard treatment protocols for patients with SCLC transformation remain unknown. Here, we report the case of a patient with advanced EGFR exon 19 deletion (19del) NSCLC who underwent SCLC transformation during targeted therapy. Biopsies and genetic testing were performed to adjust treatment regimens accordingly. The patient responded favorably to a combined treatment regimen comprising etoposide plus cisplatin chemotherapy and adebrelimab plus osimertinib. This case highlights the critical importance of acknowledging tumor heterogeneity in clinical decision-making and identifying potentially effective treatment options for patients with SCLC transformation. Additionally, we reviewed cases of the transformation of NSCLC to SCLC from 2017 to 2023.

PTBP1-mediated repression of neuron-specific CDC42 splicing constitutes a genomic alteration-independent, developmentally conserved vulnerability in IDH-wildtype glioblastoma.

Gene co-expression networks may encode hitherto inadequately recognized vulnerabilities for adult gliomas. By identifying evolutionally conserved gene co-expression modules around EGFR (EM) or PDGFRA (PM), we recently proposed an EM/PM classification scheme, which assigns IDH-wildtype glioblastomas (GBM) into the EM subtype committed in neural stem cell compartment, IDH-mutant astrocytomas and oligodendrogliomas into the PM subtype committed in early oligodendrocyte lineage. Here, we report the identification of EM/PM subtype-specific gene co-expression networks and the characterization of hub gene polypyrimidine tract-binding protein 1 (PTBP1) as a genomic alteration-independent vulnerability in IDH-wildtype GBM. Supervised by the EM/PM classification scheme, we applied weighted gene co-expression network analysis to identify subtype-specific global gene co-expression modules. These gene co-expression modules were characterized for their clinical relevance, cellular origin and conserved expression pattern during brain development. Using lentiviral vector-mediated constitutive or inducible knockdown, we characterized the effects of PTBP1 on the survival of IDH-wildtype GBM cells, which was complemented with the analysis of PTBP1-depedent splicing pattern and overexpression of splicing target neuron-specific CDC42 (CDC42-N) isoform.  Transcriptomes of adult gliomas can be robustly assigned into 4 large gene co-expression modules that are prognostically relevant and are derived from either malignant cells of the EM/PM subtypes or tumor microenvironment. The EM subtype is associated with a malignant cell-intrinsic gene module involved in pre-mRNA splicing, DNA replication and damage response, and chromosome segregation, and a microenvironment-derived gene module predominantly involved in extracellular matrix organization and infiltrating immune cells. The PM subtype is associated with two malignant cell-intrinsic gene modules predominantly involved in transcriptional regulation and mRNA translation, respectively. Expression levels of these gene modules are independent prognostic factors and malignant cell-intrinsic gene modules are conserved during brain development. Focusing on the EM subtype, we identified PTBP1 as the most significant hub for the malignant cell-intrinsic gene module. PTBP1 is not altered in most glioma genomes. PTBP1 represses the conserved splicing of CDC42-N. PTBP1 knockdown or CDC42-N overexpression disrupts actin cytoskeleton dynamics, causing accumulation of reactive oxygen species and cell apoptosis. PTBP1-mediated repression of CDC42-N splicing represents a potential genomic alteration-independent, developmentally conserved vulnerability in IDH-wildtype GBM.

Investigation into the Sonodynamic Activity of Three Newly Synthesized Derivatives of Ciprofloxacin.

Sonosensitizers play a crucial role in the efficacy of sonodynamic antitumor therapy (SDT) and sonodynamic antimicrobial chemotherapy (SACT), highlighting the necessity for the development of new compounds with good sonodynamic activity. In this study, three novel 3-substituted ciprofloxacin derivatives (CIPD1, CIPD2, and CIPD3) were designed and synthesized. Their sonodynamic activities were evaluated by assessing the damage to bovine serum albumin (BSA) and Escherichia coli (E. coli). Furthermore, the potential mechanism underlying their sonodynamic damage activities was investigated by detecting reactive oxygen species (ROS) under ultrasound irradiation (US). The results demonstrated that all three derivatives exhibited enhanced sonodynamic damage to BSA and E. coli under US, with CIPD1 and CIPD2 showing superior effectiveness compared to CIP. Both the concentrations of derivatives and the duration of ultrasound irradiation were found to significantly impact their sonodynamic effects. All three CIP derivates could be activated to produce ROS following ultrasound irradiation, primarily consisting of 1O2 and ·OH. The levels of ROS production were positively correlated with their sonodynamic activities, potentially explaining the mechanism underlying their sonodynamic damage activities.

Ultrasound-Guided Nd:YAG Laser Intervention in the Orofacial Region: Report of a Case of Multi-Focal Venous Malformation.

Venous malformation is acongenital vascular system structure malformation caused by abnormal vascular endothelial cell morphology, which can occur in any tissue or organ of the oral and maxillofacial region. Laser treatment is currently a commonly used minimally invasive treatment. In this case, the patient with congenital multiple venous malformation was treated with Nd:YAG laser for the visible submucosal part, and the subcutaneous part under the chin tip was treated with ultrasound. The chin tip was treated with ultrasound guided by the chair to achieve the purpose of minimally invasive laser treatment. In this case's diagnosis and treatment process, we hope to provide a new idea for laser treatment of oromaxillofacial vein malformations.

Severity of inattention symptoms, experiences of being bullied, and school anxiety as mediators in the association between excessive short-form video viewing and school refusal behaviors in adolescents.

Background: Recent years have seen an increase in school refusal behavior among adolescents, potentially due to factors like excessive short-form video viewing, bullying, and school anxiety. Limited research has investigated how these factors contribute to school refusal behavior. This study used random forest regression, path analysis, and network analysis to identify key variables and pathways leading to school refusal behavior. Methods: In this cross-sectional questionnaire-based study, 2,056 (996 male, 1,060 female, mean age: 14.79 ± 1.24 years) middle and senior high school students were asked to complete the School Refusal Behavior Assessment questionnaire to assess school refusal behavior features, the Excessive Short-Form Video Viewing Scale as well as self-reported viewing times during leisure days to assess excessive short-form video viewing, the SNAP-IV Rating Scale to assess the severity of inattention symptoms, and the self-administered questionnaires to assess experiences of being bullied and school anxiety. Results: The prevalence of school refusal behavior in the surveyed adolescents was found to be 31.9% [95% confidence interval (CI): 29.8-33.9%]. In terms of significance, the severity of inattention symptoms exhibited the greatest predictive power, while excessive short-form video viewing accounted for the most variance. Path analysis revealed that excessive short-form video viewing not only directly affects school refusal behavior features but also does so indirectly through severity of inattention symptoms and school anxiety. Key bridge factors in this pathway include intense fear and anxiety associated with school attendance, manifesting as somatic symptoms and avoidance behaviors. Conclusion: The findings indicate that not only does excessive short-form video viewing directly influence school refusal behavior features in adolescents, but it also indirectly impacts these features through mechanisms involving severity of inattention symptoms and school anxiety. The bridge factors highlight potential targets for interventions among the SRB features and predictors.

Consensus clustering and novel risk score model construction based on m6A methylation regulators to evaluate the prognosis and tumor immune microenvironment of early-stage lung adenocarcinoma.

BACKGROUND: The aim of this study was to investigate the correlation between m6A methylation regulators and cell infiltration characteristics in tumor immune microenvironment (TIME), so as to help understand the immune mechanism of early-stage lung adenocarcinoma (LUAD). METHODS: The expression and consensus cluster analyses of m6A methylation regulators in early-stage LUAD were performed. The clinicopathological features, immune cell infiltration, survival and functional enrichment in different subtypes were analyzed. We also constructed a prognostic model. Clinical tissue samples were used to validate the expression of model genes through real-time polymerase chain reaction (RT-PCR). In addition, cell scratch assay and Transwell assay were also performed. RESULTS: Expression of m6A methylation regulators was abnormal in early-stage LUAD. According to the consensus clustering of m6A methylation regulators, patients with early-stage LUAD were divided into two subtypes. Two subtypes showed different infiltration levels of immune cell and survival time. A prognostic model consisting of HNRNPC, IGF2BP1 and IGF2BP3 could be used to predict the survival of early-stage LUAD. RT-PCR results showed that HNRNPC, IGF2BP1 and IGF2BP3 were significantly up-regulated in early-stage LUAD tissues. The results of cell scratch assay and Transwell assay showed that overexpression of HNRNPC promotes the migration and invasion of NCI-H1299 cells, while knockdown HNRNPC inhibits the migration and invasion of NCI-H1299 cells. CONCLUSIONS: This work reveals that m6A methylation regulators may be potential biomarkers for prognosis in patients with early-stage LUAD. Our prognostic model may be of great value in predicting the prognosis of early-stage LUAD.

Masked cross-domain self-supervised deep learning framework for photoacoustic computed tomography reconstruction.

Accurate image reconstruction is crucial for photoacoustic (PA) computed tomography (PACT). Recently, deep learning has been used to reconstruct PA images with a supervised scheme, which requires high-quality images as ground truth labels. However, practical implementations encounter inevitable trade-offs between cost and performance due to the expensive nature of employing additional channels for accessing more measurements. Here, we propose a masked cross-domain self-supervised (CDSS) reconstruction strategy to overcome the lack of ground truth labels from limited PA measurements. We implement the self-supervised reconstruction in a model-based form. Simultaneously, we take advantage of self-supervision to enforce the consistency of measurements and images across three partitions of the measured PA data, achieved by randomly masking different channels. Our findings indicate that dynamically masking a substantial proportion of channels, such as 80%, yields meaningful self-supervisors in both the image and signal domains. Consequently, this approach reduces the multiplicity of pseudo solutions and enables efficient image reconstruction using fewer PA measurements, ultimately minimizing reconstruction error. Experimental results on in-vivo PACT dataset of mice demonstrate the potential of our self-supervised framework. Moreover, our method exhibits impressive performance, achieving a structural similarity index (SSIM) of 0.87 in an extreme sparse case utilizing only 13 channels, which outperforms the performance of the supervised scheme with 16 channels (0.77 SSIM). Adding to its advantages, our method can be deployed on different trainable models in an end-to-end manner, further enhancing its versatility and applicability.

Carvedilol to prevent hepatic decompensation of cirrhosis in patients with clinically significant portal hypertension stratified by new non-invasive model (CHESS2306).

Background & Aims: Non-invasive models stratifying clinically significant portal hypertension (CSPH) are limited. Herein, we developed a new non-invasive model for predicting CSPH in patients with compensated cirrhosis and investigated whether carvedilol can prevent hepatic decompensation in patients with high-risk CSPH stratified using the new model. Methods: Non-invasive risk factors of CSPH were identified via systematic review and meta-analysis of studies involving patients with hepatic venous pressure gradient (HVPG). A new non-invasive model was validated for various performance aspects in three cohorts, i.e., a multicenter HVPG cohort, a follow-up cohort, and a carvedilol-treating cohort. Results: In the meta-analysis with six studies (n = 819), liver stiffness measurement and platelet count were identified as independent risk factors for CSPH and were used to develop the new "CSPH risk" model. In the HVPG cohort (n = 151), the new model accurately predicted CSPH with cutoff values of 0 and -0.68 for ruling in and out CSPH, respectively. In the follow-up cohort (n = 1,102), the cumulative incidences of decompensation events significantly differed using the cutoff values of <-0.68 (low-risk), -0.68 to 0 (medium-risk), and >0 (high-risk). In the carvedilol-treated cohort, patients with high-risk CSPH treated with carvedilol (n = 81) had lower rates of decompensation events than non-selective beta-blockers untreated patients with high-risk CSPH (n = 613 before propensity score matching [PSM], n = 162 after PSM). Conclusions: Treatment with carvedilol significantly reduces the risk of hepatic decompensation in patients with high-risk CSPH stratified by the new model.

Preoperative computed tomography-guided localization for pulmonary nodules: comparison between hook-wire and anchored needle localization.

Introduction: Both hook-wire (HW) and anchored needle (AN) techniques can be used for preoperative computed tomography (CT)-guided localization for pulmonary nodules (PNs). But the outcomes associated with these two materials remain unclear. Aim: To assess the relative safety and efficacy of preoperative CT-guided HW and AN localization for PNs. Material and methods: This was a retrospective analysis of data collected from two institutions. Consecutive patients with PNs between January 2020 and December 2021 who underwent preoperative CT-guided HW or AN localization followed by video-assisted thoracoscopic surgery (VATS) procedures were included in these analyses, which compared the safety and clinical efficiency of these two localization strategies. Results: In total, 98 patients (105 PNs) and 93 patients (107 PNs) underwent CT-guided HW and AN localization procedures, respectively. The HW and AN groups exhibited similar rates of successful PN localization (95.2% vs. 99.1%, p = 0.117), but the dislodgement rate in the HW group was significantly higher than that for the AN group (4.8% vs. 0.0%, p = 0.029). The mean pain score of patients in the HW group was significantly higher than that for the AN group (p = 0.001). HW and AN localization strategies were associated with comparable pneumothorax (21.4% vs. 16.1%, p = 0.349) and pulmonary hemorrhage (29.6% vs. 23.7%, p = 0.354) rates. All patients other than 1 individual in the HW group successfully underwent VATS-guided limited resection. Conclusions: These data suggest that AN represents a safe, well-tolerated, feasible preoperative localization strategy for PNs that may offer value as a replacement for HW localization.

Molecular Editing of Pyrroles to Benzenes/Naphthalenes by N2O Deletion.

Molecular editing promises to facilitate the rapid diversification of complex molecular architectures by rapidly and conveniently altering core frameworks. This approach has the potential to accelerate both drug discovery and total synthesis. In this study, we present a novel protocol for the molecular editing of pyrroles. Initially, N-Boc pyrroles and alkynes are converted into N-bridged compounds through a Diels-Alder reaction. These compounds then undergo deprotection of the Boc group, nitrosylation, and cheletropic N2O extrusion to yield benzene or naphthalene products. By using benzyne as a substrate, this method can be conceptually viewed as a fusion of skeletal editing of the pyrrole ring and site-selective peripheral editing of the benzene ring. Furthermore, this proof-of-concept protocol has demonstrated its potential to transform the (hetero)arene motif from commercially available drugs, offering the possibility of generating new biologically active compounds.

Equol: a metabolite of gut microbiota with potential antitumor effects.

An increasing number of studies have shown that the consumption of soybeans and soybeans products is beneficial to human health, and the biological activity of soy products may be attributed to the presence of Soy Isoflavones (SI) in soybeans. In the intestinal tracts of humans and animals, certain specific bacteria can metabolize soy isoflavones into equol. Equol has a similar chemical structure to endogenous estradiol in the human body, which can bind with estrogen receptors and exert weak estrogen effects. Therefore, equol plays an important role in the occurrence and development of a variety of hormone-dependent malignancies such as breast cancer and prostate cancer. Despite the numerous health benefits of equol for humans, only 30-50% of the population can metabolize soy isoflavones into equol, with individual variation in gut microbiota being the main reason. This article provides an overview of the relevant gut microbiota involved in the synthesis of equol and its anti-tumor effects in various types of cancer. It also summarizes the molecular mechanisms underlying its anti-tumor properties, aiming to provide a more reliable theoretical basis for the rational utilization of equol in the field of cancer treatment.

ZnO NPs induce miR-342-5p mediated ferroptosis of spermatocytes through the NF-κB pathway in mice.

BACKGROUND: Zinc oxide nanoparticle (ZnO NP) is one of the metal nanomaterials with extensive use in many fields such as feed additive and textile, which is an emerging threat to human health due to widely distributed in the environment. Thus, there is an urgent need to understand the toxic effects associated with ZnO NPs. Although previous studies have found accumulation of ZnO NPs in testis, the molecular mechanism of ZnO NPs dominated a decline in male fertility have not been elucidated. RESULTS: We reported that ZnO NPs exposure caused testicular dysfunction and identified spermatocytes as the primary damaged site induced by ZnO NPs. ZnO NPs led to the dysfunction of spermatocytes, including impaired cell proliferation and mitochondrial damage. In addition, we found that ZnO NPs induced ferroptosis of spermatocytes through the increase of intracellular chelatable iron content and lipid peroxidation level. Moreover, the transcriptome analysis of testis indicated that ZnO NPs weakened the expression of miR-342-5p, which can target Erc1 to block the NF-κB pathway. Eventually, ferroptosis of spermatocytes was ameliorated by suppressing the expression of Erc1. CONCLUSIONS: The present study reveals a novel mechanism in that miR-342-5p targeted Erc1 to activate NF-κB signaling pathway is required for ZnO NPs-induced ferroptosis, and provide potential targets for further research on the prevention and treatment of male reproductive disorders related to ZnO NPs.

Neohesperidin exerts subtle yet comprehensive regulation of mouse dental papilla cell-23 in vitro.

OBJECTIVE: The molecular regulation of odontoblasts in dentin formation remains largely uncharacterized. Using neohesperidin (NEO), a well-documented osteoblast regulator, we investigated whether and how NEO participates in odontoblast regulation through longitudinal treatments using various doses of NEO. DESIGN: Mouse dental papilla cell-23 (MDPC-23) served as a model for odontoblasts. MDPC-23 were treated with various doses of NEO (0, 1, 5, 10, 15, 20 µmol/L). Proliferation was assessed using the Cell counting kit-8 assay. Survival/apoptosis was assayed by live/dead ratio. Migration capability was assessed using scratch healing and Transwell migration assays. Mineralization was assessed using alkaline phosphatase staining and alizarin red staining. The expression levels of four key genes (Runx2, osteocalcin [OCN], ß-catenin, and bone morphogenetic protein [BMP]-2) representing NEO-induced differentiation of MDPC-23 were measured by quantitative reverse transcription polymerase chain reaction. RESULTS: The proliferation trajectories of MDPC-23 treated with the five doses of NEO demonstrated similar curves, with a rapid increase in the 10 µmol/L NEO condition after 48 h of treatment. Similar dose-dependent trajectories were observed for survival/apoptosis. All four key genes representing odontogenic differentiation were upregulated in MDPC-23 induced by NEO treatments at two optimal doses (5 µmol/L and 10 µmol/L). Optimal migration and mobility trajectories were observed in MDPC-23 treated with 10 µmol/L NEO. Optimal mineralization was observed in MDPC-23 treated with 5 µmol/L NEO. CONCLUSION: NEO can subtly regulate odontoblast proliferation, differentiation, migration, and mineralization in vitro. NEO at 5-10 µmol/L offers a safe and effective perspective for clinical promotion of dentin bridge formation in teenagers.

Dopamine ß-hydroxylase shapes intestinal inflammation through modulating T cell activation.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic and relapsing disease characterized by immune-mediated dysfunction of intestinal homeostasis. Alteration of the enteric nervous system and the subsequent neuro-immune interaction are thought to contribute to the initiation and progression of IBD. However, the role of dopamine beta-hydroxylase (DBH), an enzyme converting dopamine into norepinephrine, in modulating intestinal inflammation is not well defined. METHODS: CD4+CD45RBhighT cell adoptive transfer, and 2,4-dinitrobenzene sulfonic acid (DNBS) or dextran sodium sulfate (DSS)-induced colitis were collectively conducted to uncover the effects of DBH inhibition by nepicastat, a DBH inhibitor, in mucosal ulceration, disease severity, and T cell function. RESULTS: Inhibition of DBH by nepicastat triggered therapeutic effects on T cell adoptive transfer induced chronic mouse colitis model, which was consistent with the gene expression of DBH in multiple cell populations including T cells. Furthermore, DBH inhibition dramatically ameliorated the disease activity and colon shortening in chemically induced acute and chronic IBD models, as evidenced by morphological and histological examinations. The reshaped systemic inflammatory status was largely associated with decreased pro-inflammatory mediators, such as TNF-α, IL-6 and IFN-γ in plasma and re-balanced Th1, Th17 and Tregs in mesenteric lymph nodes (MLNs) upon colitis progression. Additionally, the conversion from dopamine (DA) to norepinephrine (NE) was inhibited resulting in increase in DA level and decrease in NE level and DA/NE showed immune-modulatory effects on the activation of immune cells. CONCLUSION: Modulation of neurotransmitter levels via inhibition of DBH exerted protective effects on progression of murine colitis by modulating the neuro-immune axis. These findings suggested a promising new therapeutic strategy for attenuating intestinal inflammation.

Nomogram to Estimate the Risk of Chronic Kidney Disease-Associated Pruritus in Patients with End-Stage Renal Disease Undergoing Peritoneal Dialysis: Model Development and Validation Study.

INTRODUCTION: Chronic kidney disease-associated pruritus (CKD-aP) frequently occurs in patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) and presents a therapeutic challenge to physicians owing to the diversity of its pathogenesis. Herein, we developed and validated a nomogram model for individualized risk estimation of CKD-aP and investigated the possible causes of CKD-aP in PD patients. METHODS: We retrospectively screened patients with CKD-aP who underwent PD between 2021 and 2023 at the First Affiliated Hospital of Xi'an Jiaotong University Peritoneal Dialysis Center. Nomograms for each outcome were computed from multivariate logistic regression models with the least absolute shrinkage and selection operator regression and univariate logistic regression for variable selection. The discriminative ability was estimated by Harrell's C-index, and the accuracy was assessed graphically with a calibration curve plot. Models were validated internally using bootstrapping and externally by calculating their performance on a validation cohort. Decision curve analysis was used to assess the model's clinical usefulness. RESULTS: In all, a total of 487 patients were entered in the analysis, including 325 in the development cohort and 162 in the validation cohort. The final nomogram incorporated five variables: age, interleukin-6, hemoglobin, residual urine volume, and renal Kt/V. The C-index of the model was 0.733 (95% CI: 0.679-0.787), and the calibration curve was a straight line with a slope close to 1. Both internal and external validations confirmed the model's good performance, with C-index of 0.725 (95% CI: 0.662-0.774) and 0.706 (95% CI: 0.623-0.789), respectively. Decision curve analysis showed that the nomogram had good clinical benefits. CONCLUSION: Our study proposes a nomogram model for CKD-aP risk assessment in ESRD patients with PD. This nomogram might help in clinical decision-making and evidence-based selection of therapy.

A comprehensive immunobiology review of IBD: With a specific glance to Th22 lymphocytes development, biology, function, and role in IBD.

The two primary forms of inflammatory disorders of the small intestine andcolon that make up inflammatory bowel disease (IBD) are ulcerative colitis (UC) and Crohn's disease (CD). While ulcerative colitis primarily affects the colon and the rectum, CD affects the small and large intestines, as well as the esophagus,mouth, anus, andstomach. Although the etiology of IBD is not completely clear, and there are many unknowns about it, the development, progression, and recurrence of IBD are significantly influenced by the activity of immune system cells, particularly lymphocytes, given that the disease is primarily caused by the immune system stimulation and activation against gastrointestinal (GI) tract components due to the inflammation caused by environmental factors such as viral or bacterial infections, etc. in genetically predisposed individuals. Maintaining homeostasis and the integrity of the mucosal barrier are critical in stopping the development of IBD. Specific immune system cells and the quantity of secretory mucus and microbiome are vital in maintaining this stability. Th22 cells are helper T lymphocyte subtypes that are particularly important for maintaining the integrity and equilibrium of the mucosal barrier. This review discusses the most recent research on these cells' biology, function, and evolution and their involvement in IBD.

The gut microbiota derived metabolite trimethylamine N-oxide: Its important role in cancer and other diseases.

An expanding body of research indicates a correlation between the gut microbiota and various diseases. Metabolites produced by the gut microbiota act as mediators between the gut microbiota and the host, interacting with multiple systems in the human body to regulate physiological or pathological functions. However, further investigation is still required to elucidate the underlying mechanisms. One such metabolite involved in choline metabolism by gut microbes is trimethylamine (TMA), which can traverse the intestinal epithelial barrier and enter the bloodstream, ultimately reaching the liver where it undergoes oxidation catalyzed by flavin-containing monooxygenase 3 (FMO3) to form trimethylamine N-oxide (TMAO). While some TMAO is eliminated through renal excretion, remaining amounts circulate in the bloodstream, leading to systemic inflammation, endoplasmic reticulum (ER) stress, mitochondrial stress, and disruption of normal physiological functions in humans. As a representative microbial metabolite originating from the gut, TMAO has significant potential both as a biomarker for monitoring disease occurrence and progression and for tailoring personalized treatment strategies for patients. This review provides an extensive overview of TMAO sources and its metabolism in human blood, as well as its impact on several major human diseases. Additionally, we explore the latest research areas related to TMAO along with future directions.

Enhancement on migration and biodegradation of Diaphorobacter sp. LW2 mediated by Pythium ultimum in soil with different particle sizes.

Introduction: The composition and structure of natural soil are very complex, leading to the difficult contact between hydrophobic organic compounds and degrading-bacteria in contaminated soil, making pollutants hard to be removed from the soil. Several researches have reported the bacterial migration in unsaturated soil mediated by fungal hyphae, but bacterial movement in soil of different particle sizes or in heterogeneous soil was unclear. The remediation of contaminated soil enhanced by hyphae still needs further research. Methods: In this case, the migration and biodegradation of Diaphorobacter sp. LW2 in soil was investigated in presence of Pythium ultimum. Results: Hyphae could promote the growth and migration of LW2 in culture medium. It was also confirmed that LW2 was able to migrate in the growth direction and against the growth direction along hyphae. Mediated by hyphae, motile strain LW2 translocated over 3 cm in soil with different particle size (CS1, 1.0-2.0 mm; CS2, 0.5-1.0mm; MS, 0.25-0.5 mm and FS, <0.25 mm), and it need shorter time in bigger particle soils. In inhomogeneous soil, hyphae participated in the distribution of introduced bacteria, and the total number of bacteria increased. Pythium ultimum enhanced the migration and survival of LW2 in soil, improving the bioremediation of polluted soil. Discussion: The results of this study indicate that the mobilization of degrading bacteria mediated by Pythium ultimum in soil has great potential for application in bioremediation of contaminated soil.