Establishment and application of PDCoV antigen-specific DAS-ELISA detection method.

BACKGROUND: Porcine deltacoronavirus (PDCoV) is a swine enteropathogenic coronavirus that affects young pigs, causing vomiting, acute diarrhea, dehydration, and even death. There is growing evidence that PDCoV can undergo cross-species as well as zoonotic transmissions. Due to the frequent outbreaks of this deadly virus, early detection is essential for effective prevention and control. Therefore, developing a more convenient and reliable method for PDCoV detection is the need of the hour. RESULTS: This study utilized a high-affinity monoclonal antibody as the capture antibody and a horseradish peroxidase labeled polyclonal antibody as the detection antibody to develop an enzyme-linked immunosorbent assay (DAS-ELSA) for PDCoV detection.Both antibodies target the PDCoV nucleocapsid (N) protein. The findings of this study revealed that DAS-ELISA was highly specific to PDCoV and did not cross-react with other viruses to cause swine diarrhea. The limit of detection of the virus titer using this method was 103 TCID50/mL of PDCoV particles. The results of a parallel analysis of 239 known pig samples revealed a coincidence rate of 97.07% (κ = 0.922) using DAS-ELISA and reverse transcriptase PCR (RT-PCR). The DAS-ELISA was used to measure the one-step growth curve of PDCoV in LLC-PK cells and the tissue distribution of PDCoV in infected piglets. The study found that the DAS-ELISA was comparable in accuracy to the TCID50 method while measuring the one-step growth curve. Furthermore, the tissue distribution measured by DAS-ELISA was also consistent with the qRT-PCR method. CONCLUSION: The developed DAS-ELISA method can be conveniently used for the early clinical detection of PDCoV infection in pigs, and it may also serve as an alternative method for laboratory testing of PDCoV.

Deep Diversity-Enhanced Feature Representation of Hyperspectral Images.

In this paper, we study the problem of efficiently and effectively embedding the high-dimensional spatio-spectral information of hyperspectral (HS) images, guided by feature diversity. Specifically, based on the theoretical formulation that feature diversity is correlated with the rank of the unfolded kernel matrix, we rectify 3D convolution by modifying its topology to enhance the rank upper-bound. This modification yields a rank-enhanced spatial-spectral symmetrical convolution set (ReS 3-ConvSet), which not only learns diverse and powerful feature representations but also saves network parameters. Additionally, we also propose a novel diversity-aware regularization (DA-Reg) term that directly acts on the feature maps to maximize independence among elements. To demonstrate the superiority of the proposed ReS 3-ConvSet and DA-Reg, we apply them to various HS image processing and analysis tasks, including denoising, spatial super-resolution, and classification. Extensive experiments show that the proposed approaches outperform state-of-the-art methods both quantitatively and qualitatively to a significant extent. The code is publicly available at https://github.com/jinnh/ReSSS-ConvSet.

Deep Posterior Distribution-Based Embedding for Hyperspectral Image Super-Resolution.

In this paper, we investigate the problem of hyperspectral (HS) image spatial super-resolution via deep learning. Particularly, we focus on how to embed the high-dimensional spatial-spectral information of HS images efficiently and effectively. Specifically, in contrast to existing methods adopting empirically-designed network modules, we formulate HS embedding as an approximation of the posterior distribution of a set of carefully-defined HS embedding events, including layer-wise spatial-spectral feature extraction and network-level feature aggregation. Then, we incorporate the proposed feature embedding scheme into a source-consistent super-resolution framework that is physically-interpretable, producing PDE-Net, in which high-resolution (HR) HS images are iteratively refined from the residuals between input low-resolution (LR) HS images and pseudo-LR-HS images degenerated from reconstructed HR-HS images via probability-inspired HS embedding. Extensive experiments over three common benchmark datasets demonstrate that PDE-Net achieves superior performance over state-of-the-art methods. Besides, the probabilistic characteristic of this kind of networks can provide the epistemic uncertainty of the network outputs, which may bring additional benefits when used for other HS image-based applications. The code will be publicly available at https://github.com/jinnh/PDE-Net.

Identification, characterization, and molecular application of a virulence-associated autotransporter from a pathogenic Pseudomonas fluorescens strain.

A gene, pfa1, encoding an autotransporter was cloned from a pathogenic Pseudomonas fluorescens strain, TSS, isolated from diseased fish. The expression of pfa1 is enhanced during infection and is regulated by growth phase and growth conditions. Mutation of pfa1 significantly attenuates the overall bacterial virulence of TSS and impairs the abilities of TSS in biofilm production, interaction with host cells, modulation of host immune responses, and dissemination in host blood. The putative protein encoded by pfa1 is 1,242 amino acids in length and characterized by the presence of three functional domains that are typical for autotransporters. The passenger domain of PfaI contains a putative serine protease (Pap) that exhibits apparent proteolytic activity when expressed in and purified from Escherichia coli as a recombinant protein. Consistent with the important role played by PfaI in bacterial virulence, purified recombinant Pap has a profound cytotoxic effect on cultured fish cells. Enzymatic analysis showed that recombinant Pap is relatively heat stable and has an optimal temperature and pH of 50 degrees C and pH 8.0. The domains of PfaI that are essential to autotransporting activity were localized, and on the basis of this, a PfaI-based autodisplay system (named AT1) was engineered to facilitate the insertion and transport of heterologous proteins. When expressed in E. coli, AT1 was able to deliver an integrated Edwardsiella tarda immunogen (Et18) onto the surface of bacterial cells. Compared to purified recombinant Et18, Et18 displayed by E. coli via AT1 induced significantly enhanced immunoprotection.

Identification and characterization of the AcrR/AcrAB system of a pathogenic Edwardsiella tarda strain.

Edwardsiella tarda is one of the leading marine pathogens that can infect a wide range of cultured marine species. In this study, the acrR-acrAB cluster was cloned from TX1, a pathogenic E. tarda strain isolated from diseased fish. AcrR and AcrAB were found to be involved in resistance against acriflavine and methyl viologen, which positively regulate the expression of acrAB. AcrR negatively regulates its own expression and the expression of the acrAB operon, most likely by interacting with a 24-bp operator site that overlaps the putative promoter of acrA (P(acrA)). The repressive effect of AcrR on P(acrA) could be relieved by acriflavine, methyl viologen, and ethidium bromide, the presence of each of which enhanced transcription from P(acrA). Interruption of the regulated expression of acrR by introducing into TX1 a plasmid that overexpresses acrR affected growth under stress conditions, AI-2 production, and bacterial virulence. In addition, mutational analyses identified a constitutively active AcrR mutant (named N215), which exhibits full repressor activity but is impaired in its ability to interact with the inducer. Overexpression of N215 produced the same kind of but moderately stronger effect on TX1 compared to that produced by overexpression of the wild-type acrR.

Primary small cell carcinoma of the esophagus: clinicopathological and immunohistochemical features of 21 cases.

BACKGROUND: Primary small cell carcinoma (SCC) of the esophagus is a rare and aggressive tumor with poor prognosis. In this study, we report the clinicopathological characteristics of 21 cases of small cell carcinoma of the esophagus treated at the Cancer Center of Sun Yat-Sen University, with particular focus on the histologic and immunohistochemical findings. METHODS: Twenty-one patient records were reviewed including presenting symptoms, demographics, disease stage, treatment, and follow-up. Histologic features were observed and immunohistochemical detection of cytokeratin (CK), epithelial membrane antigen (EMA), neuron specific enolase (NSE), synaptophysin (Syn), chromogranin A (CgA), neuronal cell adhesion molecules (CD56), thyroid transcriptional factor-1 (TTF-1) and S100 protein (S100) was performed. RESULTS: The median age of patients in the study was 56 years, with a male-to-female ratio of 3.2:1. Histologically, there were 19 "homogenous" SCC esophageal samples and 2 samples comprised of SCC and well-differentiated squamous cell carcinoma. The percentages of SCC samples with positive immunoreactivity were Syn 95.2%, CD56 76.2%, TTF-1 71.4%, NSE 61.9%, CgA 61.9%, CK 57.1%, EMA 61.9%, and S100 19.0%, respectively. The median patient survival time was 18.3 months after diagnosis. The 2-year survival rate was 28.6%. CONCLUSION: Our study suggests that esophageal SCC has similar histology to SCC that arises in the lung compartment, and Chinese patients have a poor prognosis. Higher proportion of positive labeling of Syn, CD56, CgA, NSE, and TTF-1 in esophageal SCC implicate that they are valuably applied in differential diagnosis of the malignancy.

[Detection of Y chromosome in human and Microtus mandarinus with FISH].

The purpose of the investigation was to detect the Y chromosome of human and Microtus mandarinus with the satellite DNA probe in human's Yq by fluorescence in situ hybridization(FISH). We hybridizied the probe with the metaphase chromosome and interphase nucleus specimens of humanbeing and Microtus mandarinus respectively. The results showed that there was hybridization signal on metaphase chromosome and interphase nucleus of human, but no signal on metaphase chromosome and interphase nucleus of Microtus mandarinus. According to the results,we discussed the homologue between pY3.4 in Y chromosome of humanbeing and DNA of Microtus mandarinus and FISH result of Microtus mandarinus.

Clinicopathological investigation of four cases of desmoplastic small round cell tumor.

The purpose of this study was to perform clinicopathological and immunohistochemical analysis and to investigate the Ewing sarcoma gene (EWS)-Wilms' tumor suppressor gene (WT1) fusion within desmoplastic small round cell tumors (DSRCTs). Histology slides and clinical data were reviewed for four patients with DSRCT. A variety of immunohistochemical staining was performed. Fluorescence in situ hybridization (FISH) was performed to detect the EWS-WT1 fusion transcripts resulting from the chromosomal translocation t(11;22)(p13;q12). The patients consisted of four males aged from 26 to 52 years old (mean, 33.5). In three of these patients, the tumors were situated in the abdominal cavity and the tumor from the other patient was located in the pelvic cavity. The tumors were 8-15 cm in diameter (mean tumor diameter, 13), solid and gray-white, with an appearance of nodosity or sublobes, and hemorrhage or necrosis was observed. Microscopically, the tumors consisted of small round cell nests of unequal size. Hyperplastic and thick fibrous connective tissue surrounding the neoplastic cell nests was present in all cases. The tumor nuclei were hyperchromatic and contained inconspicuous nucleoli with a high level of karyokinesis. Immunohistochemical staining revealed diffuse and strong staining for CK, vimentin, desmin and CAM5.2 in all cases. Certain cases also expressed WT-1, EMA, NSE, CD56, CD99 and CK5/6. Staining was negative for myogenin, MyoD1, calretinin, CD117, CD34, HMB45 and CEA. EWS-WT1 fusion transcripts were detected in 3 out of 4 cases, but not in any other tumor types studied as controls using paraffin-embedded tissue by FISH. DSRCT is a highly maligant tumor occuring predominantly in the abdominal or pelvic cavity of young males with multiphenotypic differentiation. Basic morphological features, clinical manifestations and the detection of the EWS-WT1 fusion transcript within the tumor aid the recognition and diagnosis of the tumor.

Prognostic significance of TAZ expression in resected non-small cell lung cancer.

INTRODUCTION: Transcriptional coactivator with PDZ-binding motif (TAZ) is known to bind to a variety of transcription factors to control cell differentiation and organ development. Recently, TAZ has been identified as an oncogene and has an important role in tumorigenicity of non-small cell lung cancer (NSCLC). Therefore, TAZ may present a novel target for the future diagnosis, prognosis, and therapy for lung cancer. We investigated the relationship between TAZ expression and clinicopathological parameters and determined its prognostic significance concerning survival in patients with resected NSCLC. METHODS: TAZ expression was immunohistochemically studied in 181 consecutive patients with NSCLC and 20 cases of normal lung tissue. The association between expression of TAZ and clinicopathological parameters was evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of TAZ expression on survival. RESULTS: TAZ expression was observed in 121 of the 181 (66.8%) NSCLC. TAZ had nuclear and cytoplasmic expression. Clinicopathologically, TAZ expression was significantly associated with lung adenocarcinoma (p = 0. 002), poorer differentiation (p = 0.001), p-tumor, node, metastasis stage (p = 0.001), lymph node metastasis (p = 0.032), intratumoral vascular invasion (p = 0.004), pleural invasion (p = 0.003), adjuvant chemotherapy (p = 0.044), and poorer prognosis (p = 0.002). Multivariable analysis confirmed that TAZ expression increased the hazard of death after adjusting for other clinicopathological factors (hazard ratio, 2.56; 95% confidence interval, 1.39-4.66; p = 0.01). Overall survival was significantly prolonged in TAZ negative group when compared with TAZ positive group (61.8 versus 47.1 months; p < 0.0001), as was disease-free survival (44.3 versus 25.1 months; p < 0.0001). Adjuvant chemotherapy prolonged overall survival among resected NSCLC patients with TAZ positive expression (p = 0.001). CONCLUSIONS: This study suggests that TAZ expression is a prognostic indicator of poorer survival probability for patients with resected NSCLC.

A clinicopathological aspect of primary small-cell carcinoma of the uterine cervix: a single-centre study of 25 cases.

AIMS: Small-cell carcinoma is a variant of poorly differentiated neuroendocrine carcinoma. Primary small-cell carcinoma of the cervix (SCCC) is recognised as a rare and aggressive malignant tumour with poor prognosis. In this study, the authors report 25 Chinese cases of SCCC, with a particular focus on their clinical and pathological characteristics. MATERIAL AND METHODS: The records of 25 patients from 4075 Chinese patients with cervical cancer were collected and reviewed, including the patients' age, initial symptoms, cervical tumour size, International Federation of Gynaecology and Obstetrics clinical stage, lymph-node metastasis, treatments and follow-up results. Immunohistochemical detection was performed for cytokeratin, epithelial membrane antigen, neuron-specific enolase (NSE), synaptophysin (Syn), chromogranin A (CgA), neuronal cell adhesion molecules (CD56), thyroid transcriptional factor-1 and S100 protein (S100). RESULTS: The median age of 25 patients with SCCC was 43.7 years. The most common symptom was abnormal vaginal bleeding. Histologically, there were 19 'homogenous' SCCC samples and six samples of SCCC mixed with adenocarcinoma. The proportion of SCCC samples with positive immunoreactivity were 100.0% for NSE, 96.0% for Syn, 68.0% for CD56, 76.0% for CgA, 40.0% for thyroid transcriptional factor-1, 84.0% for epithelial membrane antigen, 68.0% for cytokeratin and 8.0% for S100, respectively. Every patient received one to three types of treatments, including surgery, chemotherapy and radiotherapy. The median survival time of patients was 20.9 months after diagnosis. CONCLUSION: The higher proportion of positive labelling of Syn, CD56, CgA, and NSE in SCCC implicated that they are valuably applied in a differential diagnosis of the malignancy. The patients with SCCC receive one to three types of therapies, including surgery, chemotherapy and radiotherapy, and have a poor prognosis.

Immunoprotective analysis of VhhP2, a Vibrio harveyi vaccine candidate.

VhhP2 is an outer membrane protein identified in a pathogenic Vibrio harveyi strain, T4, isolated from diseased fish. When used as a subunit vaccine, purified recombinant VhhP2 affords high level of protection upon Japanese flounder against V. harveyi challenge. Vaccination with VhhP2 induced the expression of a number of immune-related genes, especially those encoding immunoglobulin M (IgM) and major histocompatibility complex (MHC) IIalpha. A VhhP2 surface display system, in the form of the fish commensal strain PF3 harboring the vhhP2-expressing plasmid pJVP, was constructed. PF3/pJVP is able to produce and present recombinant VhhP2 on cell surface. Vaccination of fish with live PF3/pJVP via intraperitoneal injection elicited strong immunoprotection. Vaccination of fish orally with live PF3/pJVP embedded in alginate microspheres also induced effective immunoprotection. In addition, a VhhP2-based surface display system was created, in which VhhP2 serves as a carrier for the surface delivery of a heterologous Edwardsiella tarda immunogen, Et18, that is fused in-frame to VhhP2. DH5alpha/pJVP18, which expresses and surface-displays the VhhP2-Et18 chimera, proved to be an effective vaccine that can protect fish against infections by V. harveyi and E. tarda to the extents comparable to those produced by vaccination with purified recombinant VhhP2 and Et18, respectively. These data suggest that VhhP2 may be applied as a vaccine and a vaccine carrier against infections by V. harveyi and other pathogens such as E. tarda.

The origin of the genetical diversity of Microtus mandarinus chromosomes.

Here we describe our comparative studies on two types of X chromosomes, namely X(M) and X(SM,) of the mandarin vole (Microtus mandarinus). By chromosome G- and C-banding analysis, we have found that two different types of X chromosomes exist in mandarin voles. The two types of X chromosomes present two different G- and C-banding patterns: the X(M) chromosome is a longer metacentric X chromosome which is C-band negative; and the X(SM) is a shorter submetacentric X chromosome which has one C-band at the centromere and another one at the middle part of the short arm. The X(SM) has 6 G-bands including one on the kinetochore, one in the middle of the short arm, and four on the long arm. The X(M) has 7 G-bands including one on the kinetochore, two on the short arm, and four on the long arm. We have further found that female voles can be grouped into three types based on the composition of the X chromosome but the male voles have only one type. The three female groups are: (1) female voles (X(M)X(SM)), in which the two X chromosomes are different, the longer one is metacentric and the shorter is submetacentric; (2) female vole (X(SM)X(SM)), in which the two X chromosomes are both submetacentric; (3) female vole (X(M)O), in which there is only one X chromosome that is metacentric. Surprisingly, we have never found female voles with X(M)X(M), females with X(SM)O or males with X(M)Y. We hypothesize that the X(SM) chromosome is derived from the X(M) through its breakage and re-joining. The paper also discusses the formation of X(M)O females.

[Expression and significance of p53 and proliferating cell nuclear antigen in malignant tumor of maxillary sinus].

BACKGROUND & OBJECTIVE: p53 and proliferating cell nuclear antigen (PCNA) play an important role in the development of malignant tumor. This study was designed to evaluate the role of p53 and PCNA in the development of malignant tumor of maxillary sinus by detecting their expression in malignant, benign, and inflammatory lesions of maxillary sinus. METHODS: The expressions of p53 and PCNA were detected by immunohistochemistry in 108 malignant, 19 benign, and 8 inflammatory tissues of maxillary sinus. Rank sum test was used and the levels of positive degree of p53 and PCNA were represented by mean rank. RESULTS: The mean ranks of p53 and PCNA were 42.8 and 47.9 in inflammatory group and 50.3 and 46.8 in benign group, but 73.0 and 73.2 in malignant group, respectively. In malignant group, mean rank of p53 in squamous cell carcinoma (SCC) was 60.7, which was higher than that in adenocarcinoma (43.9). The differences were significant (P < 0.05). While from stage I to stage IV, the mean ranks of p53 were 46.6, 50.1, 56.1, and 55.0 and the mean ranks of PCNA were 60.5, 48.8, 56.1, and.