Characterization of the endothiapepsin-like protein in the entomopathogenic fungus Beauveria bassiana and its virulence effect on the silkworm, Bombyx mori.

Endothiapepsin is an aspartic proteinase that was first isolated from the plant pathogenic fungus Endothia parasitica. In previous studies, we reported on three endothiapepsin-like proteins in the entomopathogenic fungus Beauveria bassiana; the genes were up-regulated in B. bassiana hyper-virulent strain GXsk1011 at early stage infection in the silkworm. However, whether these proteins play a role in pathogenicity or not remains unknown. In this study, we cloned one protein, BbepnL-1 gene (BBA-07766), that has 98% homology with B. bassiana strain Bb2860, and expressed it in the yeast Pichia pastoris to investigate its function. The endothiapepsin-like protein is a secreted proteinase of molecular weight approximately 40 kDa. It has an N-glycosylation site and a mutation in the C-terminal conserved domain- a Thr was mutated to Gly in B. bassiana GXsk1011 and is different than the endothiapepsin of Endothia parasitica. The recombinant endothiapepsin-like protein showed enzyme activity and degraded the protein components of the silkworm cuticle. To further investigate the activity of the endothiapepsin-like protein, we knocked out the gene BbepnL-1 and showed that the loss of BbepnL-1 reduced the virulence in the silkworm. These results demonstrated that the endothiapepsin-like protein of B. bassiana is a virulence factor.

Transcriptomic analysis of two Beauveria bassiana strains grown on cuticle extracts of the silkworm uncovers their different metabolic response at early infection stage.

Beauveria bassiana is an important entomopathogenic fungus which not only widely distributes in the environment but also shows phenotypic diversity. However, the mechanism of pathogenic differences among natural B. bassiana strains has not been revealed at transcriptome-wide level. In the present study, in order to explore the mechanism, two B. bassiana strains with different pathogenicity were isolated from silkworms (Bombyx mori L.) and selected to analyze the gene expression of early stage by culturing on cuticle extracts of the silkworm and using RNA-sequencing technique. A total of 2108 up-regulated and 1115 down-regulated genes were identified in B. bassiana strain GXsk1011 (hyper-virulent strain) compared with B. bassiana strain GXtr1009 (hypo-virulent strain), respectively. The function categorization of differential expressed genes (DEGs) showed that most of them involved in metabolic process, biosynthesis of secondary metabolites, catalytic activity, and some involved in nutrition uptake, adhesion and host defense were also noted. Based on our data, distinct pathogenicity among different strains of B. bassiana may largely attribute to unique gene expression pattern which differed at very early infection process. Most of the genes involved in conidia adhesion, cuticle degradation and fungal growth were up-regulated in hyper-virulent B. bassiana strain GXsk1011. Furthermore, in combination with fungal growth analysis, our research provided a clue that fungal growth may also play an important role during early infection process. The results will help to explain why different B. bassiana strains show distinct pathogenicity on the same host even under same condition. Moreover, the transcriptome data were also useful for screening potential virulence factors.

Tracheoesophageal fistula closure after staged dose-escalated radiotherapy for esophageal squamous cell carcinoma: a case report.

An esophageal fistula can be caused by an esophageal tumor as well as the surgery, radiotherapy (RT), or chemoradiotherapy used to treat the tumor. The most dangerous complications are massive hemoptysis and asphyxia. This report describes a 58-year-old man with a >1-month history of dysphagia and hemoptysis. Contrast-enhanced computed tomography revealed a tumor in the upper esophagus and a tracheoesophageal fistula. Esophagography revealed a large lesion measuring approximately 8 cm in length. Esophagogastroduodenoscopy showed an ulcerated tumor with raised margins originating 22 cm from the incisors, and histologic examination of a biopsy specimen indicated squamous cell carcinoma. The tumor was finally classified as stage IVA (T4bN0M0) esophageal squamous cell carcinoma. Massive hemoptysis occurred after the patient was admitted to the hospital. Therefore, we applied staged dose-escalated RT in three stages (6.0 Gy in 5 fractions, 7.5 Gy in 5 fractions, and 46.8 Gy in 26 fractions) to decrease the rate of tumor shrinkage brought on by RT and give the normal tissue enough time to close the fistula. Finally, the hemoptysis resolved and the patient's symptoms were significantly improved. Contrast-enhanced chest computed tomography revealed shrinkage of the tumor. In conclusion, staged dose-escalated RT can be applied for esophageal fistula closure.

Mucosa-associated lymphoid tissue lymphoma of the trachea treated with radiotherapy: A case report.

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma originates in the marginal zone of lymphoid tissue. lung is one of the most frequent non-gastrointestinal organs involved, here known as bronchus-associated lymphoid tissue (BALT) lymphoma. BALT lymphoma of unknown etiology, and most patients are asymptomatic. The treatment of BALT lymphoma is controversial. CASE SUMMARY: A 55-year-old man admitted to hospital had a three-month history of progressively coughing up yellow sputum, chest stuffiness, and shortness of breath. Fiberoptic bronchoscopy revealed mucosal visible beaded bumps 4 cm from the tracheal carina at 9 o 'clock and 3 o 'clock, the right main bronchus, and the right upper lobe bronchus. Biopsy specimens showed MALT lymphoma. Computed tomography virtual bronchoscopy (CTVB) showed uneven main bronchial wall thickening and multiple nodular protrusion. BALT lymphoma stage IE was diagnosed after a staging examination. We treated the patient with radiotherapy (RT) alone. A total dose of 30.6 Gy/17 f/25 d was given. The patient had no obvious adverse reactions during RT. The CTVB was repeated after RT and showed that the right side of the trachea was slightly thickened. CTVB was repeated 1.5 mo after RT and again showed that the right side of the trachea was slightly thickened. Annual CTVB showed no signs of recurrence. The patient now has no symptoms. CONCLUSION: BALT lymphoma is an uncommon disease and shows good prognosis. The treatment of BALT lymphoma is controversial. In recent years, less invasive diagnostic and therapeutic approaches have been emerging. RT was effective and safe in our case. The use of CTVB could provide a noninvasive, repeatable, and accurate method in diagnosis and follow-up.

Implementation of Constant Dose Rate and Constant Angular Spacing Intensity-modulated Arc Therapy for Cervical Cancer by Using a Conventional Linear Accelerator.

BACKGROUND: Volumetric-modulated arc therapy (VMAT) can only be implemented on the new generation linacs such as the Varian Trilogy® and Elekta Synergy®. This prevents most existing linacs from delivering VMAT. The purpose of this study was to investigate the feasibility of using a conventional linear accelerator delivering constant dose rate and constant angular spacing intensity-modulated arc therapy (CDR-CAS-IMAT) for treating cervical cancer. METHODS: Twenty patients with cervical cancer previously treated with intensity-modulated radiation therapy (IMRT) using Varian Clinical 23EX were retreated using CDR-CAS-IMAT. The planning target volume (PTV) was set as 50.4 Gy in 28 fractions. Plans were evaluated based on the ability to meet the dose volume histogram. The homogeneity index (HI), target volume conformity index (CI), the dose to organs at risk, radiation delivery time, and monitor units (MUs) were also compared. The paired t-test was used to analyze the two data sets. All statistical analyses were performed using SPSS 19.0 software. RESULTS: Compared to the IMRT group, the CDR-CAS-IMAT group showed better PTV CI (0.85 ± 0.03 vs. 0.81 ± 0.03, P = 0.001), clinical target volume CI (0.46 ± 0.05 vs. 0.43 ± 0.05, P = 0.001), HI (0.09 ± 0.02 vs. 0.11 ± 0.02, P = 0.005) and D95 (5196.33 ± 28.24 cGy vs. 5162.63 ± 31.12 cGy, P = 0.000), and cord D2 (3743.8 ± 118.7 cGy vs. 3806.2 ± 98.7 cGy, P = 0.017) and rectum V40 (41.9 ± 6.1% vs. 44.2 ± 4.8%, P = 0.026). Treatment time (422.7 ± 46.7 s vs. 84.6 ± 7.8 s, P = 0.000) and the total plan Mus (927.4 ± 79.1 vs. 787.5 ± 78.5, P = 0.000) decreased by a factor of 0.8 and 0.15, respectively. The IMRT group plans were superior to the CDR-CAS-IMAT group plans considering decreasing bladder V50 (17.4 ± 4.5% vs. 16.6 ± 4.2%, P = 0.049), bowel V30 (39.6 ± 6.5% vs. 36.6 ± 7.5%, P = 0.008), and low-dose irradiation volume; there were no significant differences in other statistical indexes. CONCLUSIONS: Patients with cervical cancer treated with CDR-CAS-IMAT using Varian Clinical 23EX can get equivalent or superior dose distribution compared to those treated with IMRT. CDR-CAS-IMAT has a less treatment time and MU, which can reduce the uncertainty factor and patient discomfort in treatment.

Salvage radiotherapy in patients with local recurrent esophageal cancer after radical radiochemotherapy.

PURPOSE: The aim of this study was to evaluate the salvage radiotherapy outcome in patients with local recurrent esophageal cancer after radical radiochemotherapy (RCT). METHODS: A total of 114 patients with local recurrent esophageal squamous cell carcinoma after initial radical RCT were retrospectively analyzed. Fifty-five (55) patients belonged to the salvage radiotherapy group (SR group) and 59 patients to the non-salvage radiotherapy group (NSR group). RESULTS: The median survival time after-recurrence was 4 months in all patients. The 1, 2, 3 year overall survival (OS) rates were 83.6%, 41.8% and 21.8% respectively in the SR group, and 57.6%, 16.9%, and 8.5% in the NSR group. The 6-month and 1-year survival rates after-recurrence were 41.8% and 16.4% respectively in the SR group, and 11.9% and 3.4% respectively in the NSR group. A salvage radiation dose > 50 Gy after initial radical RCT, improved the survival of patients with local recurrent esophageal cancer. Three patients (5.45%) from the SR group showed more than 3-grade radiation pneumonitis. In addition, esophageal fistula/perforation was observed in 11 cases (20.0%) in the SR group and in 8 cases (13.6%) in the NSR group. CONCLUSIONS: Salvage treatment after definitive RCT may improve the overall survival and survival after-recurrence of patients with local recurrent esophageal cancer.

Encoding of rat working memory by power of multi-channel local field potentials via sparse non-negative matrix factorization.

Working memory plays an important role in human cognition. This study investigated how working memory was encoded by the power of multi-channel local field potentials (LFPs) based on sparse nonnegative matrix factorization (SNMF). SNMF was used to extract features from LFPs recorded from the prefrontal cortex of four Sprague-Dawley rats during a memory task in a Y maze, with 10 trials for each rat. Then the power-increased LFP components were selected as working memory-related features and the other components were removed. After that, the inverse operation of SNMF was used to study the encoding of working memory in the time-frequency domain. We demonstrated that theta and gamma power increased significantly during the working memory task. The results suggested that postsynaptic activity was simulated well by the sparse activity model. The theta and gamma bands were meaningful for encoding working memory.