Antigenicity, epitope mapping, and intracellular distribution of the NSP7α protein of porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen that causes huge economic losses to the global pig industry. Nonstructural protein 7α (NSP7α) of PRRSV is highly conserved among different lineages of PRRSV and could be a potential target for the development of detection methods. In this study, NSP7α was expressed in prokaryote (Escherichia coli) and purified. An NSP7α-ab-ELISA detection method was established, the NSP7α-ab-ELISA has 93.1 % coincidence rate with IDEXX PRRS X3 ab test kit. NSP7α antibody was detected in pig serum by ELISA 14 days following PRRSV infection. Three monoclonal antibodies (4H9, 3F2, and C10) against NSP7α prepared by a hybridoma technique were used for epitope mapping by indirect immunofluorescence. The 4H9, 3F2, and C10 antibodies all recognized the C-terminal 72-149 amino acid region of NSP7α. 4H9 reacted with amino acids 135-143, but 3F2 and C10 did not react with any truncated polypeptide. In addition, by using the monoclonal antibodies, NSP7α was localized solely in the cytoplasm, while the N protein was distributed in the cytoplasm and nucleus. The collective findings of the antigenicity and epitope of NSP7α will be helpful for understanding the antigenicity of NSP7α and developing PRRSV diagnostic methods.

Dietary habits and nutrition status in esophageal cancer patients after esophageal reconstruction.

Background: Surgery is the cornerstone of the treatment of esophageal cancer (EC). This study is to evaluate the dietary habits and nutrition status in EC patients who underwent esophagectomy followed by esophageal reconstruction. Methods: This retrospective study included patients with EC who underwent esophagectomy followed by esophageal reconstruction in the Department of Thoracic Surgery I of Peking University Cancer Hospital between February 2014 and December 2018. The primary outcomes were dietary habits and nutrition status. The secondary outcomes were gastrointestinal symptoms and quality of life (QoL). Results: A total of 346 patients were included. At 30 months after the operation, 90.2% of the patients had recovered to regular dietary habits, 72.8% of patients had a restored frequency of preoperative regular food intake, 2.3% of the patients ate more than six times a day, and 0.6% had semi-liquid food because of bad teeth. The nutrition status remained stable after 6 months postoperatively and recovered slightly 1 year after the surgery. At 30 months after the operation, the most common gastrointestinal symptoms were reflux (38.4%), dysphagia (15.3%), hoarseness (11.8%), abdominal distension (6.6%), diarrhea (2.9%), and nausea and vomiting (2.3%). According to the European Organization for Research and Treatment of Cancer, Quality of Life Questionnaire-OG 25 (EORTC QLQ-OG 25), the factors that affected the life quality of patients during follow-up were anxiety, reflux, and dietary limitations. Conclusions: Most patients with EC who underwent esophageal reconstruction recovered to regular dietary habits and stable nutrition status, while some may still suffer from gastrointestinal symptoms, anxiety, and dietary limitations.

Long-Term Survival and Recurrence Patterns in Locally Advanced Esophageal Squamous Cell Carcinoma Patients with Pathologic Complete Response After Neoadjuvant Chemotherapy Followed by Surgery.

BACKGROUND: The higher pathologic complete response (pCR) after neoadjuvant chemoradiotherapy compared with neoadjuvant chemotherapy for locally advanced esophageal squamous cell carcinoma (ESCC) has not translated into significant gains in overall survival. Data on the long-term survival of patients who obtained a pCR after neoadjuvant chemotherapy are scarce. Therefore, this study aimed to evaluate the long-term prognosis and recurrence patterns in these patients. METHODS: The study enrolled patients with locally advanced ESCC after neoadjuvant chemotherapy followed by surgery in the authors' hospital between January 2007 and December 2020. The factors predictive of pCR were analyzed. Furthermore, propensity score-matching was performed for those who did and those who did not have a pCR using 1:5 ratio for a long-term survival analysis. Finally, the survival and recurrence patterns of patients obtaining pCR after neoadjuvant chemotherapy were analyzed. RESULTS: A pCR was achieved for 61 (8.70%) of the 701 patients in the study. Univariate analysis showed that the patients without alcohol drinking had a higher possibility of obtaining a pCR, although multivariate analysis failed to confirm the difference as significant. After propensity score-matching, the 5-year overall survival was 84.50% for the patients who had a pCR and 52.90% for those who did not (p < 0.001). Among the 61 patients with a pCR, 9 patients (14.80%) experienced recurrence, including 6 patients with locoregional recurrence and 3 patients with distant metastasis. CONCLUSION: Advanced ESCC patients with pCR after neoadjuvant chemotherapy had a favorable prognosis, yet some still experienced recurrence, particularly locoregional recurrence. Therefore, for this group of patients, regular follow-up evaluation also is needed.

Machine Learning Methods Based on CT Features Differentiate G1/G2 From G3 Pancreatic Neuroendocrine Tumors.

RATIONALE AND OBJECTIVES: To identify CT features for distinguishing grade 1 (G1)/grade 2 (G2) from grade 3 (G3) pancreatic neuroendocrine tumors (PNETs) using different machine learning (ML) methods. MATERIALS AND METHODS: A total of 147 patients with 155 lesions confirmed by pathology were retrospectively included. Clinical-demographic and radiological CT features was collected. The entire cohort was separated into training and validation groups at a 7:3 ratio. Least absolute shrinkage and selection operator (LASSO) algorithm and principal component analysis (PCA) were used to select features. Three ML methods, namely logistic regression (LR), support vector machine (SVM), and K-nearest neighbor (KNN) were used to build a differential model. Receiver operating characteristic (ROC) curves and precision-recall curves for each ML method were generated. The area under the curve (AUC), accuracy rate, sensitivity, and specificity were calculated. RESULTS: G3 PNETs were more likely to present with invasive behaviors and lower enhancement than G1/G2 PNETs. The LR classifier yielded the highest AUC of 0.964 (95% confidence interval [CI]: 0.930, 0.972), with 95.4% accuracy rate, 95.7% sensitivity, and 92.9% specificity, followed by SVM (AUC: 0.957) and KNN (AUC: 0.893) in the training group. In the validation group, the SVM classier reached the highest AUC of 0.952 (95% CI: 0.860, 0.981), with 91.5% accuracy rate, 97.3% sensitivity, and 70% specificity, followed by LR (AUC: 0.949) and KNN (AUC: 0.923). CONCLUSIONS: The LR and SVM classifiers had the best performance in the training group and validation group, respectively. ML method could be helpful in differentiating between G1/G2 and G3 PNETs.

A noninvasive nomogram model based on CT features to predict DNA mismatch repair deficiency in gastric cancer.

Objectives: DNA mismatch repair deficiency (dMMR) status has served as a positive predictive biomarker for immunotherapy and long-term prognosis in gastric cancer (GC). The aim of the present study was to develop a computed tomography (CT)-based nomogram for preoperatively predicting mismatch repair (MMR) status in GC. Methods: Data from a total of 159 GC patients between January 2020 and July 2021 with dMMR GC (n=53) and MMR-proficient (pMMR) GC (n=106) confirmed by postoperative immunohistochemistry (IHC) staining were retrospectively analyzed. All patients underwent abdominal contrast-enhanced CT. Significant clinical and CT imaging features associated with dMMR GC were extracted through univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis, decision curve analysis (DCA) and internal validation of the cohort data were performed. Results: The nomogram contained four potential predictors of dMMR GC, including gender (odds ratio [OR] 9.83, 95% confidence interval [CI] 3.78-28.20, P < 0.001), age (OR 3.32, 95% CI 1.36-8.50, P = 0.010), tumor size (OR 5.66, 95% CI 2.12-16.27, P < 0.001) and normalized tumor enhancement ratio (NTER) (OR 0.15, 95% CI 0.06-0.38, P < 0.001). Using an optimal cutoff value of 6.6 points, the nomogram provided an area under the curve (AUC) of 0.895 and an accuracy of 82.39% in predicting dMMR GC. The calibration curve demonstrated a strong consistency between the predicted risk and observed dMMR GC. The DCA justified the relatively good performance of the nomogram model. Conclusion: The CT-based nomogram holds promise as a noninvasive, concise and accurate tool to predict MMR status in GC patients, which can assist in clinical decision-making.

Pre-operative oil ingestion reduces the probability of thoracic duct trunk ligation during esophagectomy.

Chylothorax is an important complication after esophagectomy. Ligation of the injured thoracic duct is the main method to prevent chylothorax after esophagectomy, but may be associated with adverse effects. Whether ligation of the injured tributary alone, keeping the main trunk intact, may suffice to prevent post-operative chylothorax is not well known. Since March 2017, 40 mL of olive oil was administered to patients posted for esophagectomy. We compared patients admitted between March 2017 and December 2019 with patients admitted between July 2014 and February 2017, who had not received pre-operative oil. The outcome measures were the need for thoracic duct main trunk or tributary ligation, development of chylothorax and missed ligation. There were 371 patients in the oil ingestion group and 308 patients in the standard control group. Chylothorax in the oil ingestion group was significantly lower than that in the standard control group (1.3% vs. 4.5%, P = 0.012). Chyle leak from thoracic duct tributaries was diagnosed in a significantly higher percentage (5.7% vs. 0.0%, P < 0.001) and missed ligation of the injured thoracic duct was significantly lower (0.3% vs. 3.9%, P = 0.002) in the oil ingestion group compared with the standard control group. The incidence of post-operative chylothorax was not statistically different (6.3% vs. 10.0%, P = 1.000) between the tributary and the trunk ligation group. Pre-operative oil ingestion can help visualize the thoracic duct trunk and its tributaries during esophagectomy. Thus, non-selected thoracic duct trunk ligation and missed ligation during esophagectomy can be reduced. Precise ligation of the injured tributary while the main trunk is intact can also prevent post-operative chylothorax.

Streptococcus suis Serotype 2 Infection Induces Splenomegaly with Splenocyte Apoptosis.

Little is known about the damage to the important peripheral immune organ spleen caused by Streptococcus suis infection. In this study, we found that S. suis induced splenomegaly and lymphocyte disruption in spleens of mice. To explore the mechanism of splenic lesions induced by S. suis, we conducted further studies. The results showed that S. suis induced apoptosis in B cells, which is related to the cleavage of caspase-3 and caspase-8, but not the release of apoptosis-inducing factor (AIF). Thus, S. suis induced apoptosis in the spleen through caspase-dependent and AIF-independent pathways. Inflammation lesions induced in the spleen of infected mice were also investigated; we found macrophages increased in histopathological lesions of infected spleens from 12 h postinoculation to 7 days postinoculation (dpi), and the type of increased macrophages was M1 type by confocal microscopy, which can secrete proinflammatory cytokines. Meanwhile, inflammasome NLRP3 and caspase-1 were activated, and gasdermin D (GSDMD) was cleaved, which causes pyroptosis that may result in the release of numerous proinflammatory cytokines. What's more, the increase of p-JNK and p-p38 indicated that the MAPK pathway was also involved in the proinflammatory responses during S. suis infection, whereas anti-inflammatory responses in spleen were suppressed, with regulatory T cells (Tregs) upregulating at 1 dpi. Taken together, proinflammatory immune responses dominate in early infection, which induce splenomegaly and splenocyte apoptosis. This is the first report of mechanisms associated with S. suis-induced splenic lesions. IMPORTANCE Streptococcus suis serotype 2 is considered an emerging pathogen and represents a threat to humans and animals. The spleen is an important peripheral immune organ, and splenomegaly is a consequence of lesions and an important clinical indicator of S. suis infection. However, knowledge of the mechanisms underlying spleen lesions is still very limited. In the present work, we made the investigation to explain the phenomenon and the related immunomodulation in a mouse infection model. The obtained results show that inflammation contributes to splenomegaly, while apoptosis contributes to lymphocyte disruption in spleens. Related signaling pathways were discovered which have never been associated with S. suis-induced splenic injury. The new knowledge generated will help us better understand the mechanism of S. suis pathogenesis.

SARS-CoV-2 hijacks macropinocytosis to facilitate its entry and promote viral spike-mediated cell-to-cell fusion.

Revealing the mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry and cell-to-cell spread might provide insights for understanding the underlying mechanisms of viral pathogenesis, tropism, and virulence. The signaling pathways involved in SARS-CoV-2 entry and viral spike-mediated cell-to-cell fusion remain elusive. In the current study, we found that macropinocytosis inhibitors significantly suppressed SARS-CoV-2 infection at both the entry and viral spike-mediated cell-to-cell fusion steps. We demonstrated that SARS-CoV-2 entry required the small GTPase Rac1 and its effector kinase p21-activated kinase 1 by dominant-negative and RNAi assays in human embryonic kidney 293T-angiotensin-converting enzyme 2 cells and that the serine protease transmembrane serine protease 2 reversed the decrease in SARS-CoV-2 entry caused by the macropinocytosis inhibitors. Moreover, in the cell-to-cell fusion assay, we confirmed that macropinocytosis inhibitors significantly decreased viral spike-mediated cell-to-cell fusion. Overall, we provided evidence that SARS-CoV-2 utilizes a macropinocytosis pathway to enter target cells and to efficiently promote viral spike-mediated cell-to-cell fusion.

Characterization of Two Immunodominant Antigenic Peptides in NSP2 of PRRSV-2 and Generation of a Marker PRRSV Strain Based on the Peptides.

Porcine reproductive and respiratory syndrome (PRRS) is a widespread disease with great economic importance in the pig industry. Although vaccines against the PRRS virus (PRRSV) have been employed for more than 20 years, differentiating infected from vaccinated animals remains challenging. In this study, all 907 non-structural protein 2 (NSP2) full-length sequences of PRRSV-2 available from GenBank were aligned. Two peptides, at positions 562-627 (m1B) and 749-813 (m2B) of NSP2, were selected, and their potential for use in differential diagnosis was assessed. Both m1B and m2B were recognized by PRRSV-positive pig serum in peptide-coated enzyme-linked immunosorbent assays. Further epitope identification yielded five overlapping short peptides for the immunodominant regions of m1B and m2B. Using the infectious clone of PRRSV HuN4-F112 as a template, the deletion mutants, rHuN4-F112-m1B, rHuN4-F112-m2B, and rHuN4-F112-C5-m1B-m2B, were generated and successfully rescued in Marc-145 cells. Growth kinetics revealed that the deletion of m1B and m2B did not significantly affect virus replication. Hence, m1B and m2B show potential as molecular markers for developing a PRRSV vaccine.

Recombinant characteristics, pathogenicity, and viral shedding of a novel PRRSV variant derived from twice inter-lineage recombination.

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is a significant threat to the global pig industry. In this study, a novel recombinant PRRSV, SD043, was isolated from a pig farm experiencing disease in 2019. Phylogenetic analysis revealed that SD043 belonged to lineage 1 of PRRSV-2 while recombination analyses revealed that it is a recombinant virus from lineage 1 and lineage 8 strains. Based on further analysis, SD043 underwent recombination twice. Pathogenicity studies revealed that SD043 causes mild clinical symptoms, thymus atrophy, and severe histopathological lesions in the lungs. Notably, virus shedding in SD043-infected piglets was detectable at 10 days post-inoculation with a high viral load in the respiratory or digestive tract, indicating that the recombinant PRRSV appears to shed higher numbers of virus. Furthermore, genomic surveillance based on all available PRRSVs circulating in Shandong province revealed an increasing increase in recombinant PRRSV since 2015, with the recombinant pattern (between lineages 1 and 8) being the same as that of SD043. These findings enable a better understanding of the process of twice recombination and virus shedding of recombinant PRRSV and can strengthen the prevention and control of the PRRSV epidemic.

Quantitative analysis of enhanced CT in differentiating well-differentiated pancreatic neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas.

OBJECTIVE: To identify quantitative CT features for distinguishing well-differentiated pancreatic neuroendocrine tumors (PNETs) from poorly differentiated pancreatic neuroendocrine carcinomas (PNECs). MATERIALS AND METHODS: Seventeen patients with PNECs and 131 patients with PNETs confirmed by biopsy or surgery were retrospectively included. General demographic (sex, age) and CT quantitative parameters (arterial/portal absolute enhancement, arterial/portal relative enhancement ratio, arterial/portal enhancement ratio) were collected. Univariate and multivariate logistic regression analyses were performed to confirm independent variables for differentiating PNECs from PNETs. Receiver operating characteristic (ROC) curves for each quantitative parameter were generated to determine their diagnostic ability. RESULTS: PNECs had a much lower mean arterial/portal absolute enhancement value (19.5 ± 11.0 vs. 78.8 ± 47.2; 28.1 ± 15.8 vs. 77.0 ± 39.4), arterial/portal relative enhancement ratio (0.57 ± 0.36 vs. 2.03 ± 1.31; 0.80 ± 0.52 vs. 1.99 ± 1.13), and arterial/portal enhancement ratio (0.62 ± 0.27 vs. 1.22 ± 0.49; 0.74 ± 0.19 vs. 1.21 ± 0.36) than PNETs (all p < 0.001). After multivariable analysis, arterial absolute enhancement (odds ratio [OR]: 0.96, 95% confidence interval [CI]: 0.93, 0.99) and portal absolute enhancement (OR: 0.96, 95% CI: 0.92, 0.99) were independent factors for differentiating PNECs from PNETs. For each quantitative parameter, arterial lesion enhancement yielded the highest diagnostic performance, with an area under the curve (AUC) of 0.922 (95% CI: 0.867-0.960), followed by portal absolute enhancement. CONCLUSIONS: Arterial/portal absolute enhancements were independent predictors with good diagnostic accuracy for differentiating between PNETs and PNECs. Quantitative parameters of enhanced CT can distinguish PNECs from PNETs. KEY POINTS: • PNECs were hypovascular and had a much lower enhanced CT attenuation in both arterial and portal phases than well-differentiated PNETs. • Quantitative parameters derived from enhanced CT can be used to distinguish PNECs from PNETs. • Arterial absolute enhancement and portal absolute enhancement were independent predictive factors for differentiating between PNETs and PNECs.

Malignant transformation of heterotopic pancreas as middle esophagus adenocarcinoma-A rare case report and comprehensive literature review.

Heterotopic pancreas is a rare congenital abnormality that occurs during the growth and development process. It can be found in any part of the digestive tract, but the most common sites are the stomach, duodenum, and jejunum. Malignant transformation especially in the esophagus is rare. Here, we aim to report an unusual case of mid-esophageal adenocarcinoma that originated from a heterotopic pancreas.

Rapid visual detection of porcine reproductive and respiratory syndrome virus via recombinase polymerase amplification combined with a lateral flow dipstick.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating infectious diseases in the global swine industry. A rapid and sensitive on-site detection method for PRRS virus (PRRSV) is critically important for diagnosing PRRS. In this study, we established a method that combines reverse transcription recombinase polymerase amplification (RT-RPA) with a lateral flow dipstick (LFD) for detecting North American PRRSV (PRRSV-2). The primers and probe were designed based on the conserved region of all complete PRRSV-2 genomic sequences available in China (n = 512) from 1996 to 2020. The detection limit of the assay was 5.6 × 10-1 median tissue culture infection dose (TCID50) per reaction within 30 min at 42 °C, which was more sensitive than that of reverse transcription polymerase chain reaction (RT-PCR) (5.6 TCID50 per reaction). The assay was highly specific for the epidemic lineages of PRRSV-2 in China and did not cross-react with pseudorabies virus, porcine circovirus 2, classical swine fever virus, or porcine epidemic diarrhea virus. The assay performance was evaluated by testing 179 samples and comparing the results with those of quantitative RT-PCR (RT-qPCR). The results showed that the detection coincidence rate of RT-RPA and RT-qPCR was 100% when the cycle threshold values of RT-qPCR were < 32. The assay provides a new alternative for simple and reliable detection of PRRSV-2 and has great potential for application in the field.

Risk factors for early local lymph node recurrence of thoracic ESCC after McKeown esophagectomy.

Objectives: Even underwent radical resection, some patients of thoracic esophageal squamous cell carcinoma (ESCC) are still exposed to local recurrence in a short time. To this end, the present study sought to differentiate patient subgroups by assessing risk factors for postoperative early (within one year) local lymph node recurrence (PELLNR). Methods: ESCC patients were selected from a prospective database, and divided into high- and low-risk groups according to the time of their local lymphatic recurrence (within one year or later). Survival analysis was conducted by the Cox regression model to evaluate the overall survival (OS) between the two groups. The hazard ratio (HR) and 95% confidence interval (CI) of different variables were also calculated. Logistic regression analysis was used to explore the high-risk factors for PELLNR with the odds ratio (OR) and 95% CI calculated. Results: A total of 432 cases were included. The survival of patients in the high-risk group (n = 47) was significantly inferior to the low-risk group (n = 385) (HR = 11.331, 95% CI: 6.870-16.688, P < 0.001). The 1-year, 3-year, and 5-year OS rate of the patients in high/low-risk groups were 74.5% vs. 100%, 17% vs. 88.8%, and 11.3% vs. 79.2%, respectively (P < 0.001). Risk factors for local lymph node recurrence within one year included upper thoracic location (OR = 4.071, 95% CI: 1.499-11.055, P = 0.006), advanced T staging (pT3-4, OR = 3.258, 95% CI: 1.547-6.861, P = 0.002), advanced N staging (pN2-3, OR = 5.195, 95% CI: 2.269-11.894, P < 0.001), and neoadjuvant treatment (OR = 3.609, 95% CI: 1.716-7.589, P = 0.001). In neoadjuvant therapy subgroup, high-risk group still had unfavorable survival (Log-rank P < 0.001). Multivariate analysis demonstrated that upper thoracic location (OR = 5.064, 95% CI: 1.485-17.261, P = 0.010) and advanced N staging (pN2-3) (OR = 5.999, 95% CI: 1.986-18.115, P = 0.001) were independent risk factors for early local lymphatic recurrence. However, the cT downstaging (OR = 0.862, 95% CI: 0.241-3.086, P = 0.819) and cN downstaging (OR = 0.937, 95% CI: 0.372-2.360, P = 0.890) for patients in the neoadjuvant subgroup failed to lower PELLNR. The predominant recurrence field type was single-field. Conclusions: Thoracic ESCC patients with lymph node recurrence within one year delivered poor outcomes, with advanced stages (pT3-4/pN2-3) and upper thoracic location considered risk factors for early recurrence.

Aminopeptidase N Is an Entry Co-factor Triggering Porcine Deltacoronavirus Entry via an Endocytotic Pathway.

Porcine deltacoronavirus (PDCoV) is a recently discovered coronavirus that poses a potential threat to the global swine industry. Although we know that aminopeptidase N (APN) is important for PDCoV replication, it is unclear whether it is the primary functional receptor, and the mechanism by which it promotes viral replication is not fully understood. Here, we systematically investigated the roles of porcine APN (pAPN) during PDCoV infection of nonsusceptible cells, including in viral attachment and internalization. Using a viral entry assay, we found that PDCoV can enter nonsusceptible cells but then fails to initiate efficient replication. pAPN and PDCoV virions clearly colocalized with the endocytotic markers RAB5, RAB7, and LAMP1, suggesting that pAPN mediates PDCoV entry by an endocytotic pathway. Most importantly, our study shows that regardless of which receptor PDCoV engages, only entry by an endocytotic route ultimately leads to efficient viral replication. This knowledge should contribute to the development of efficient antiviral treatments, which are especially useful in preventing cross-species transmission. IMPORTANCE PDCoV is a pathogen with the potential for transmission across diverse species, although the mechanism of such host-switching events (from swine to other species) is poorly understood. Here, we show that PDCoV enters nonsusceptible cells but without efficient replication. We also investigated the key role played by aminopeptidase N in mediating PDCoV entry via an endocytotic pathway. Our results demonstrate that viral entry via endocytosis is a major determinant of efficient PDCoV replication. This knowledge provides a basis for future studies of the cross-species transmissibility of PDCoV and the development of appropriate antiviral drugs.

Pancreatic Serous Cystic Neoplasms and Mucinous Cystic Neoplasms: Differential Diagnosis by Combining Imaging Features and Enhanced CT Texture Analysis.

OBJECTIVE: To establish a diagnostic model by combining imaging features with enhanced CT texture analysis to differentiate pancreatic serous cystadenomas (SCNs) from pancreatic mucinous cystadenomas (MCNs). MATERIALS AND METHODS: Fifty-seven and 43 patients with pathology-confirmed SCNs and MCNs, respectively, from one center were analyzed and divided into a training cohort (n = 72) and an internal validation cohort (n = 28). An external validation cohort (n = 28) from another center was allocated. Demographic and radiological information were collected. The least absolute shrinkage and selection operator (LASSO) and recursive feature elimination linear support vector machine (RFE_LinearSVC) were implemented to select significant features. Multivariable logistic regression algorithms were conducted for model construction. Receiver operating characteristic (ROC) curves for the models were evaluated, and their prediction efficiency was quantified by the area under the curve (AUC), 95% confidence interval (95% CI), sensitivity and specificity. RESULTS: Following multivariable logistic regression analysis, the AUC was 0.932 and 0.887, the sensitivity was 87.5% and 90%, and the specificity was 82.4% and 84.6% with the training and validation cohorts, respectively, for the model combining radiological features and CT texture features. For the model based on radiological features alone, the AUC was 0.84 and 0.91, the sensitivity was 75% and 66.7%, and the specificity was 82.4% and 77% with the training and validation cohorts, respectively. CONCLUSION: This study showed that a logistic model combining radiological features and CT texture features is more effective in distinguishing SCNs from MCNs of the pancreas than a model based on radiological features alone.

A Virulent Trueperella pyogenes Isolate, Which Causes Severe Bronchoconstriction in Porcine Precision-Cut Lung Slices.

Trueperella pyogenes causes disease in cattle, sheep, goats and swine, and is involved occasionally in human disease worldwide. Most reports implicating T. pyogenes have been associated with clinical cases, whereas no report has focused on pathogenicity of T. pyogenes in mouse models or precision-cut lung slice (PCLS) cultures from swine. Here, we isolated and identified a virulent, ß-hemolytic, multidrug-resistant T. pyogenes strain named 20121, which harbors the virulence marker genes fimA, fimE, nanH, nanP and plo. It was found to be highly resistant to erythromycin, azithromycin and medemycin. Strain 20121 was pathogenic in mouse infection models, displaying pulmonary congestion and inflammatory cell infiltration, partial degeneration in epithelial cells of the tracheal and bronchiolar mucosa, a small amount of inflammatory cell infiltration in the submucosa, and bacteria (>104 CFU/g) in the lung. Importantly, we used T. pyogenes 20121 to infect porcine precision-cut lung slices (PCLS) cultures for the first time, where it caused severe bronchoconstriction. Furthermore, dexamethasone showed its ability to relieve bronchoconstriction in PCLS caused by T. pyogenes 20121, highlighting dexamethasone may assist antibiotic treatment for clinical T. pyogenes infection. This is the first report of T. pyogenes used to infect and cause bronchoconstriction in porcine PCLS. Our results suggest that porcine PCLS cultures as a valuable 3D organ model for the study of T. pyogenes infection and treatment in vitro.

Host BAG3 Is Degraded by Pseudorabies Virus pUL56 C-Terminal 181L-185L and Plays a Negative Regulation Role during Viral Lytic Infection.

Bcl2-associated athanogene (BAG) 3, which is a chaperone-mediated selective autophagy protein, plays a pivotal role in modulating the life cycle of a wide variety of viruses. Both positive and negative modulations of viruses by BAG3 were reported. However, the effects of BAG3 on pseudorabies virus (PRV) remain unknown. To investigate whether BAG3 could modulate the PRV life cycle during a lytic infection, we first identified PRV protein UL56 (pUL56) as a novel BAG3 interactor by co-immunoprecipitation and co-localization analyses. The overexpression of pUL56 induced a significant degradation of BAG3 at protein level via the lysosome pathway. The C-terminal mutations of 181L/A, 185L/A, or 181L/A-185L/A in pUL56 resulted in a deficiency in pUL56-induced BAG3 degradation. In addition, the pUL56 C-terminal mutants that lost Golgi retention abrogated pUL56-induced BAG3 degradation, which indicates a Golgi retention-dependent manner. Strikingly, BAG3 was not observed to be degraded in either wild-type or UL56-deleted PRV infected cells as compared to mock infected ones, whereas the additional two adjacent BAG3 cleaved products were found in the infected cells in a species-specific manner. Overexpression of BAG3 significantly suppressed PRV proliferation, while knockdown of BAG3 resulted in increased viral yields in HEK293T cells. Thus, these data indicated a negative regulation role of BAG3 during PRV lytic infection. Collectively, our findings revealed a novel molecular mechanism on host protein degradation induced by PRV pUL56. Moreover, we identified BAG3 as a host restricted protein during PRV lytic infection in cells.

Single Virus Tracking with Quantum Dots Packaged into Enveloped Viruses Using CRISPR.

Labeling viruses with high-photoluminescence quantum dots (QDs) for single virus tracking provides a visual tool to aid our understanding of viral infection mechanisms. However, efficiently labeling internal viral components without modifying the viral envelope and capsid remains a challenge, and existing strategies are not applicable to most viruses. Here, we have devised a strategy using the clustered regularly interspaced short palindromic repeats (CRISPR) imaging system to label the nucleic acids of Pseudorabies virus (PRV) with QDs. In this strategy, QDs were conjugated to viral nucleic acids with the help of nuclease-deactivated Cas9/gRNA complexes in the nuclei of living cells and then packaged into PRV during virion assembly. The processes of PRV-QD adsorption, cytoplasmic transport along microtubules, and nuclear entry were monitored in real time in both Vero and HeLa cells, demonstrating the utility and efficiency of the strategy in the study of viral infection.