Antibody Profiling of Dengue Severities Using Flavivirus Protein Microarrays

Dengue is a viral disease transmitted by Aedes aegypti mosquitoes. According to the World Health Organization, about half of the world's population is at risk of dengue. There are four serotypes of the dengue virus. After infection with one serotype, it will be immune to such a serotype. However, subsequent infection with other serotypes will increase the risk of severe outcomes, e.g., dengue hemorrhagic fever, dengue shock syndrome, and even death. Since severe dengue is challenging to predict and lacks molecular markers, we aim to build a multiplexed Flavivirus protein microarray (Flaviarray) that includes all of the common Flaviviruses to profile the humoral immunity and cross-reactivity in the dengue patients with different outcomes. The Flaviarrays we fabricated contained 17 Flavivirus antigens with high reproducibility (R-square = 0.96) and low detection limits (172-214 pg). We collected serums from healthy subjects (n = 36) and dengue patients within 7 days after symptom onset (mild dengue (n = 21), hospitalized nonsevere dengue (n = 29), and severe dengue (n = 36)). After profiling the serum antibodies using Flaviarrays, we found that patients with severe dengue showed higher IgG levels against multiple Flavivirus antigens. With logistic regression, we found groups of markers with high performance in distinguishing dengue patients from healthy controls as well as hospitalized from mild cases (AUC > 0.9). We further reported some single markers that were suitable to separate dengue patients from healthy controls (AUC > 0.9) and hospitalized from mild outcomes (AUC > 0.8). Together, Flaviarray is a valuable tool to profile antibody specificities, uncover novel markers for decision-making, and shed some light on early preventions and treatments.

Can NT-proBNP Levels Be an Early Biomarker of Reduced Left Ventricular Ejection Fraction in Preterm Infants?

Background/Objective: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac natriuretic hormone that cardiomyocytes release in response to ventricular stretch. It helps with the diagnosis of heart failure in adults, but this application in preterm infants has rarely been reported. This study aimed to evaluate whether NT-proBNP could be used for the early detection of reduced cardiac ejection fraction in preterm infants and the optimal timing for NT-proBNP assessment. Design/Methods: This prospective, single-center, observational study enrolled all preterm infants with NT-proBNP measurements from October 2014 to February 2022. They underwent echocardiographic examinations within 48 h of the NT-proBNP measurements. Reduced left ventricular ejection fraction was defined as below 60%. Receiver operator characteristic (ROC) curves were generated to assess the optimal NT-proBNP cutoff point for the early prediction of reduced cardiac ejection fraction. Results: A total of 68 preterm infants were enrolled, with a total of 134 NT-proBNP measurements being available for analysis. Reduced left ventricular ejection fraction was present in seven infants (10.3%) due to various underlying diseases. The NT-proBNP cutoff level for detecting reduced left ventricular ejection fraction was 9248 pg/mL, with 71.4% sensitivity and 60.8% specificity; the area under the curve was 0.623 (95% CI: 0.487~0.760). The threshold for the optimal postnatal age for applying NT-proBNP to detect reduced left ventricular ejection fraction was >2 days of life (AUC: 0.682; 95% CI: 0.518~0.845), with 70% sensitivity and 67.1% specificity. Conclusions: Although the NT-proBNP levels declined dramatically after birth, a NT-proBNP serum level of 9248 pg/mL might be helpful for the early detection of reduced ejection fraction in preterm infants, and the optimal age for detection was after 2 days of life.

[Analysis of specific sIgE detection of house dust mites and aspergillus fumigatus in 2 535 patients with respiratory allergic diseases and respiratory infectious diseases in the Guangzhou area]

Objective: To compare the specific IgE positive rates of the patients between allergic respiratory diseases and respiratory infectious diseases in Guangzhou, the relationship between the co-sensitization of house dust mite (HDM) allergen and Aspergillus fumigatus (AF) allergen and asthma, allergic rhinitis with asthma, pneumonia, upper respiratory infections, bronchitis, serum total immunoglobulin E (total Immunoglobulin E, tIgE) and age were analyzed, to provide the basis for the prevention and treatment of respiratory allergic diseases and respiratory infectious diseases in this area. Methods: A total of 2 535 patients with confirmed respiratory allergic diseases and respiratory infectious diseases were selected retrospectively from the outpatient or inpatient department of the First Affiliated Hospital of Guangzhou Medical University from April 2017 to June 2021 and detected HDM and AF specific IgE (sIgE) by the ImmunoCAP system. The age range was 1 to 89 years. The median age was 5 years. The average age was 9. ≤3 years old group n=894, 4-6 years old group n=721, 7-18 years old group n=615, 19-49 years old group n=207, >49 years old group n=98. There were 1 596 males (62.96%) and 939 females (37.04%). There were 1 279 cases of allergic diseases and 1 256 cases of respiratory infectious diseases. The different disease groups were divided into asthma group (411 cases), allergic rhinitis group (458 cases), allergic rhinitis combined with asthma group (410 cases), pneumonia group (463 cases), upper respiratory tract infection group (299 cases) and bronchitis group (494 cases). The difference of specific IgE (sIgE) and tIgE between HDM and AF was analyzed. For statistical analysis, continuous variables were tested by Mann-Whitney U. Classification data by chi-square test or Fisher's exact test. Results: 1 313 (51.79%) patients were sIgE positive for HDM allergen, 65 (2.56%) were sIgE positive for AF allergen, and 50 (1.97%) were both positive. In the respiratory allergic disease group, 877 cases (68.57%,877/1 279) were positive for HDM allergen sIgE, 57 cases (4.46%,57/1 279) were positive for AF allergen sIgE, and 44 cases (3.44%,44/1 279) were both positive; 436 cases (34.71%,436/1 256) of respiratory infectious diseases were positive for HDM allergen sIgE, 8 cases (0.64%,8/1 256) were positive for AF allergen sIgE, and 6 cases (0.48%,6/1 256) were both positive. In monosensitization, the HDM allergen sIgE sensitization rate was the highest in the allergic rhinitis & asthma group, at 80.24% (329/410). The positive rate of HDM allergen sIgE in male patients was 53.76%(858/1 596), and the positive rate in female patients was 46.22%(434/939), and the difference between the two was statistically significant (χ²=13.449, P<0.001). In polysensitization, asthma patients (5.35%,22/411) had the highest positive rate of HDM sensitization with AF, followed by allergic rhinitis patients (3.06%,14/458), allergic rhinitis with asthma (1.95%,8/410). The positive rate of respiratory infectious diseases such as pneumonia (0.43%,2/463), upper respiratory infections (0.33%,1/299), and bronchitis (0.61%,3/494) with AF was extremely low. The positive rate of HDM combined with AF in infants(≤3 years old group,0.34%, 3/894; 4-6 years old group, 0.97%, 7/721)was significantly lower than that in teenagers and adults(7-18 years old group,3.58%, 22/615; 19-49 years old group,6.28%, 13/207;>49 years old group,5.10%, 5/98).In the patients with HDM and AF combined sensitization, HDM sIgE levels were distributed in all grades, and AF sIgE levels were mainly in grades 1, 2, and 3. Conclusion: The positive rate of HDM combined with AF was higher in patients with respiratory allergic diseases such as asthma, allergic rhinitis, and allergic rhinitis combined with asthma, suggesting that clinical attention should be paid to the combination of HDM and AF in patients with asthma and allergic rhinitis, especially adults, more likely to be combined with AF.

Development of SARS-CoV-2 variant protein microarray for profiling humoral immunity in vaccinated subjects

SARS-CoV-2 is quickly evolving from wild-type to many variants and spreading around the globe. Since many people have been vaccinated with various types of vaccines, it is crucial to develop a high throughput platform for measuring the antibody responses and surrogate neutralizing activities against multiple SARS-CoV-2 variants. To meet this need, the present study developed a SARS-CoV-2 variant (CoVariant) array which consists of the extracellular domain of spike variants, e.g., wild-type, D614G, B.1.1.7, B.1.351, P.1, B.1.617, B.1.617.1, B.1.617.2, and B.1.617.3. A surrogate virus neutralization on the CoVariant array was established to quantify the bindings of antibody and host receptor ACE2 simultaneously to spike variants. By using a chimeric anti-spike antibody, we demonstrated a broad binding spectrum of antibodies while inhibiting the bindings of ACE2 to spike variants. To monitor the humoral immunities after vaccination, we collected serums from unvaccinated, partial, or fully vaccinated individuals with either mRNA-1273 or AZD1222 (ChAdOx1). The results showed partial vaccination increased the surrogate neutralization against all the mutants while full vaccination boosted the most. Although IgG, IgA, and IgM isotypes correlated with surrogate neutralizing activities, they behave differently throughout the vaccination processes. Overall, this study developed CoVariant arrays and assays for profiling the humoral responses which are useful for immune assessment, vaccine research, and drug development.

[Association of SCN2A, ABCB1 and CYP2C19*3 with genetic susceptibility to major depressive disorder]

Objective: Due to genetic factors might increase the risk of depression, this study investigated the genetic risk factors of depression in Chinese Han population by analyzing the association between 13 candidate genes and depression. Methods: 439 depression patients and 464 healthy controls were included in this case-control study. Case group consisted of 158 males and 281 females, aged (29.84±14.91) years old, who were hospitalized in three departments of the affiliated Brain Hospital of Guangzhou Medical University including Affective Disorders Department, Adult Psychiatry Department and Geriatrics Department, from February 2020 to September 2021. The control group consisted of 196 males and 268 females, aged (30.65±12.63) years old. 20 loci of 13 candidate genes in all subjects were detected by MALDI-TOF mass spectrometry. Age difference was compared using the student's t-test, the distributions of gender and genotype were analyzed with Pearson's Chi-square test. The analyses of Hardy-Weinberg equilibrium, allele frequency and the genetic association of depression were conducted using the corresponding programs in PLINK software. Results: PLINK analysis showed that SCN2A rs17183814, ABCB1 rs1045642, CYP2C19*3 rs4986893 and NAT2*5A rs1799929 were associated with depression before Bonferroni correction (χ²=10.340, P=0.001; χ²=11.010, P=0.001; χ²=9.781, P=0.002; χ²=4.481, P=0.034). The frequencies of minor alleles of above loci in the control group were 12.07%, 43.64%, 2.59% and 3.88%, respectively. The frequencies of minor alleles of loci mentioned above in the case group were 17.43%, 35.99%, 5.47% and 6.04%, respectively. OR values were 1.538, 0.726, 2.178 and 1.592, respectively. After 1 000 000 permutation tests using Max(T) permutation procedure, the four loci were still statistically significant, the empirical P-value were 0.002, 0.001, 0.003 and 0.042, respectively. However, only three loci including SCN2A rs17183814, ABCB1 rs1045642 and CYP2C19 rs4986893 had statistical significance after Bonferroni correction, the adjusted P-value were 0.026, 0.018 and 0.035, respectively. Conclusion: SCN2A rs17183814, ABCB1 rs1045642 and CYP2C19*3 rs4986893 were associated with depression's susceptibility in Chinese Han population. The A allele of SCN2A rs17183814 and CYP2C19*3 rs4986893 were risk factors for depression, while the T allele of ABCB1 rs1045642 was a protective factor for depression.

Exhausting T Cells During HIV Infection May Improve the Prognosis of Patients with COVID-19

T-cell reduction is an important characteristic of coronavirus disease 2019 (COVID-19), and its immunopathology is a subject of debate. It may be due to the direct effect of the virus on T-cell exhaustion or indirectly due to T cells redistributing to the lungs. HIV/AIDS naturally served as a T-cell exhaustion disease model for recognizing how the immune system works in the course of COVID-19. In this study, we collected the clinical charts, T-lymphocyte analysis, and chest CT of HIV patients with laboratory-confirmed COVID-19 infection who were admitted to Jin Yin-tan Hospital (Wuhan, China). The median age of the 21 patients was 47 years [interquartile range (IQR) = 40-50 years] and the median CD4 T-cell count was 183 cells/μl (IQR = 96-289 cells/μl). Eleven HIV patients were in the non-AIDS stage and 10 were in the AIDS stage. Nine patients received antiretroviral treatment (ART) and 12 patients did not receive any treatment. Compared to the reported mortality rate (nearly 4%-10%) and severity rate (up to 20%-40%) among COVID-19 patients in hospital, a benign duration with 0% severity and mortality rates was shown by 21 HIV/AIDS patients. The severity rates of COVID-19 were comparable between non-AIDS (median CD4 = 287 cells/μl) and AIDS (median CD4 = 97 cells/μl) patients, despite some of the AIDS patients having baseline lung injury stimulated by HIV: 7 patients (33%) were mild (five in the non-AIDS group and two in the AIDS group) and 14 patients (67%) were moderate (six in the non-AIDS group and eight in the AIDS group). More importantly, we found that a reduction in T-cell number positively correlates with the serum levels of interleukin 6 (IL-6) and C-reactive protein (CRP), which is contrary to the reported findings on the immune response of COVID-19 patients (lower CD4 T-cell counts with higher levels of IL-6 and CRP). In HIV/AIDS, a compromised immune system with lower CD4 T-cell counts might waive the clinical symptoms and inflammatory responses, which suggests lymphocyte redistribution as an immunopathology leading to lymphopenia in COVID-19.

[Efficacy of 1 384 cases of peritoneal carcinomatosis underwent cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy]

Objective: Peritoneal carcinomatosis refers to a group of heterogeneous (primary or secondary) malignancies in the surface of the peritoneum. Cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is a comprehensive treatment strategy aiming at peritoneal carcinomatosis. This study analyzed the efficacy and safety of CRS+HIPEC in patients with peritoneal carcinomatosis, and explored prognostic factors. Methods: In this descriptive case-series study, the clinicopathological data of 1384 consecutive patients with peritoneal carcinomatosis treated in Zhongnan Hospital of Wuhan University (330 patients) and Shijitan Hospital of Capital Medical University (1054 patients) from January 2004 to January 2020 were collected retrospectively. Treatment patterns of CRS+HIPEC characteristics (operative time, number of resected organs, number of stripped peritoneum, number of anastomosis, and HIPEC regimens), safety [blood loss volume, postoperative severe adverse event (SAE) and treatment outcome], survival time and prognostic factors influencing survival were analyzed. The SAE was defined as grade III-IV adverse event according to the Peritoneal Surface Oncology Group International Textbook. Perioperative period was defined from the day of CRS+HIPEC to postoperative 30th day. OS was calculated from the day of CRS+HIPEC to the date of death or the last follow-up. Kaplan-Meier method was used for survival analysis, and log-rank test was used for comparison between groups. Cox regression model was used to identify the prognostic factors. Results: Among 1384 peritoneal carcinomatosis patients, 529 (38.2%) were male; median age was 55 (10-87) years old; median body mass index (BMI) was 22.6 kg/m(2); peritoneal carcinomatosis of 164 (11.8%) patients were from gastric cancer, 287 (20.7%) from colorectal cancer, 356 (25.7%) from pseudomyxoma peritonei, 90 (6.5%) from malignant peritoneal mesothelioma, 300 (21.7%) from gynecological cancer or primary peritoneal carcinoma, and 187 (13.5%) from retroperitoneal sarcoma, lung cancer, breast cancer, and other rare tumors. The median duration of CRS+HIPEC was 595 (90-1170) minutes, median number of resected organs was 2 (0-10), median number of resected peritoneal area were 4 (0-9), median peritoneal cancer index (PCI) was 21(1-39). Completeness of cytoreduction (CC) score of 0-1 was observed in 857 cases (61.9%). Regarding HIPEC regimens, there were 917 cases (66.3%) with cisplatin plus docetaxel, 183 cases (13.2%) with cisplatin plus mitomycin, 43 cases (3.1%) with adriamycin plus ifosfamide, and the other 240 cases (17.3%) with modified regimens. Perioperative SAE developed in 331 peritoneal carcinomatosis patients (23.9%) with 500 cases, of whom 21 patients (1.5%) died during the perioperative period due to ineffective treatment, while the others recovered after active treatment. During median follow-up time of 8.6 (0.3-82.7) months, there were 414 deaths (29.9%). The median OS was 38.2 months (95% CI: 30.6-45.8), and the 1-, 3-, 5-year survival rate was 73.5%, 50.4% and 39.3%, respectively. The median OS of peritoneal carcinomatosis patients from gastric cancer, colorectal cancer, pseudomyxoma peritonei, malignant peritoneal mesothelioma and female genital cancer or primary peritoneal carcinomatosis was 11.3 months (95% CI: 8.9-13.8), 18.1 months (95% CI: 13.5-22.6), 59.7 months (95% CI: 48.0-71.4), 19.5 months (95% CI: 6.0-33.0) and 51.7 months (95% CI: 14.6-88.8), respectively, and the difference among groups was statistically significant (P<0.001). Univariate and multivariate analyses revealed that the primary gastric cancer (HR=4.639, 95% CI: 1.692-12.724), primary colorectal cancer (HR=4.292, 95% CI: 1.957-9.420), primary malignant peritoneal mesothelioma (HR=2.741, 95% CI: 1.162-6.466), Karnofsky performance status (KPS) score of 60 (HR=4.606, 95% CI: 2.144-9.895), KPS score of 70 (HR=3.434, 95% CI: 1.977-5.965), CC score of 1 (HR=2.683, 95% CI: 1.440~4.999), CC score of 2-3 (HR=3.661,95% CI: 1.956-6.852) and perioperative SAE (HR=2.588, 95% CI: 1.846-3.629) were independent prognostic factors influencing survival with statistically significant differences (all P<0.05). Conclusions: CRS+HIPEC is an effective integrated treatment strategy for patients with peritoneal carcinomatosis, which can prolong survival with acceptable safety. Preoperative evaluation of patients' general condition is necessary and CRS+HIPEC should be carefully considered to perform for patients with preoperative KPS score <80. During the operation, the optimal CRS should be achieved on condition that safety is granted. In addition, it is necessary to prevent perioperative SAE to reduce the risk of death in peritoneal carcinomatosis patients.

[A comparison of clinical characteristics between patients with and without"recurrence"RNA positive with COVID-19]

Objective: To analysis the clinical characteristics of"recurrence"RNA positive patients with Coronavirus disease 2019 （COVID-19） and compared with those without"recurrence". Methods: 98 patients with COVID-19 in Wuhan Jinyintan Hospital and designated treatment hospitals in Quanzhou were included in this study from February 2020 to April 2020. There were 55 males and 43 females， aged from15 to 83 years， with a median age of 57.5 years， in which 20 cases were complicated with basic diseases. 15 of these patients had been diagnosed and hospitalized had been found as"recurrence"2019-nCoV RNA positive after discharge while the other 83 cases were all negative. The clinical classification of all patients was common type. Clinical data of the COVID-19 RNA"recurrence"patients were collected， and general situations， symptoms， laboratory examinations and CT images were also observed and analyzed. The patients were divided into 2019-nCoV"recurrent"group and 2019-nCoV"non-recurrent"group. There are 10 males and 5 females in 2019-nCoV"recurrent"group while 45 males and 38 females in"non-recurrent"group （χ²=0.800，P=0.371）. The age of 2019-nCoV"recurrent"group （57±21） was higher than that of"non-recurrent"group（53±17）. 8 of 15 the COVID-19"recurrent"group patients and 12 of 83"non-recurrent"patients have basic diseases. IgG and IgM of 2019-nCoV， IL-6， procalcitonin， ESR， CRP， BNP and other serum biochemical index levels were measured and compared between groups. Results: （1） The proportion of patients with common type of COVID-19 was 15.3% during 2-week medical observation after discharge. （2） All of the 2019-nCoV"recurrent"patients were hospitalized due to COVID-19 RNA positive， when they were quarantined after discharged from hospital. All the patients with mild symptoms which were clarified as common type， including 5 cases of fever， 6 cases of cough， 5 cases of expectoration， and 2 cases of slight shortness of breath. The time of symptoms appeared on （5.73±2.82） days after discharge. （3） The serum procalcitonin of all 2019-nCoV"recurrent"group patients were normal（all<0.05 ng/ml）. The BNP of"recurrent"group （151±171） ng/L， was higher than that of"non-recurrent"group （63±78） ng/L （t = 3.207， P = 0.000）. There was no significant difference in laboratory tests like leukocyte ［（6.17±2.4） and （6.04±2.41）×10⁹/L］， lymphocyte［（1.59±0.52） and （1.32±0.64）×10⁹/L］， CRP ［（12.54±28.20） and （21.74±25.63）mg/L］， ESR ［（31.07±28.72） and （34.10±22.16）mm/1 h］， AST ［（24.73±9.15） and （30.24±23.20）U/L］， ALT ［（22.60±12.82） and （36.47±34.12）U/L）， LDH ［（268±208） and （270±164）U/L］， D-dimer ［（0.60±0.50） and （0.84±0.98）μg/L］， ferritin ［（294±195） and （395±319）μg/L］， IL-6 ［（9.17±6.42） and （14.28±17.74）ng/L］ and BUN （5.77±2.66） and （4.74±2.81）U/L］ between"recurrent"and"non-recurrent"groups （all P>0.05）. （4） In"recurrent"group， ground glass， exudative or solid lesions could be found in most of the chest CT performed on re-admission. Meanwhile， fibrosis lesion was relatively rare. （5） There were no secondary transmissions were found to be caused by the 2019-nCoV"recurrent"group patients. Conclusions: Most of the 2019-nCoV patients had underlying diseases and active lesions were still found in CT images， so the possibility of virus replication may still exist. All"recurrent"patients had mild illness which may suggest that they were in recovery stage, and no evidence of transmission is found.

Emergence of macrolide-resistant Streptococcus pyogenes emm12 in southern Taiwan from 2000 to 2019

BACKGROUND

Group A Streptococcus (GAS) is an important pathogen causing morbidity and mortality worldwide. Surveillance of resistance and emm type has important implication to provide helpful information on the changing GAS epidemiology and empirical treatment.

METHODS

To study the emergence of resistant GAS in children with upper respiratory tract infection (URTI), a retrospective study was conducted from 2000 to 2019 in southern Taiwan. Microbiological studies, including antibiotic susceptibility, were performed. GAS emm types and sequences were determined by molecular methods. The population was divided into two separate decades to analyze potential changes over time. The 1st decade was 2000-2009; the 2nd decade was 2010-2019. Multivariate analyses were performed to identify independent risk factors associated with macrolide resistance between these periods.

RESULTS

A total of 320 GAS from 339 children were enrolled. Most of the children (75%) were under 9 years of age. The most common diagnosis was scarlet fever (225, 66.4%), and the frequency increased from 54.8% in the 1st to 77.9% in the 2nd decade (p < 0.0001). There was a significant increase in resistance to erythromycin and azithromycin from 18.1%, 19.3% in the 1st to 58.4%, 61.0% in the 2nd decade (p < 0.0001). This was associated with clonal expansion of the GAS emm12-ST36 which carrying erm(B) and tet(M) from 3.0% in the 1st to 53.2% in the 2nd decade (p < 0.0001).

CONCLUSIONS

Significant emergence of macrolide-resistant GAS emm12-ST36 in children supports the need for continuing surveillance and investigation for the clonal virulence.

[SAMHD1 acts at stalled replication forks to prevent interferon induction]

DNA replication is an extremely complex process, involving thousands of replication forks progressing along chromosomes. These forks are frequently slowed down or stopped by various obstacles, such as secondary DNA structures, chromatin-acting proteins or a lack of nucleotides. This slowing down, known as replicative stress, plays a central role in tumour development. Complex processes, which are not yet fully understood, are set up to respond to this stress. Certain nucleases, such as MRE11 and DNA2, degrade the neo-replicated DNA at the level of blocked forks, allowing the replication to restart. The interferon pathway is a defense mechanism against pathogens that detects the presence of foreign nucleic acids in the cytoplasm and activates the innate immune response. DNA fragments resulting from genomic DNA metabolism (repair, retrotransposition) can diffuse into the cytoplasm and activate this pathway. A pathological manifestation of this process is the Aicardi-Goutières syndrome, a rare disease characterized by chronic inflammation leading to neurodegenerative and developmental problems. In this encephalopathy, it has been suggested that DNA replication may generate cytosolic DNA fragments, but the mechanisms involved have not been characterized. SAMHD1 is frequently mutated in the Aicardi-Goutières syndrome as well as in some cancers, but its role in the etiology of these diseases was largely unknown. We show that cytosolic DNA accumulates in SAMHD1-deficient cells, particularly in the presence of replicative stress, activating the interferon response. SAMHD1 is important for DNA replication under normal conditions and for the processing of stopped forks, independent of its dNTPase activity. In addition, SAMHD1 stimulates the exonuclease activity of MRE11 in vitro. When SAMHD1 is absent, degradation of neosynthesized DNA is inhibited, which prevents activation of the replication checkpoint and leads to failure to restart the replication forks. Resection of the replication forks is performed by an alternative mechanism which releases DNA fragments into the cytosol, activating the interferon response. The results obtained show, for the first time, a direct link between the response to replication stress and the production of interferons. These results have important implications for our understanding of the Aicardi-Goutières syndrome and cancers related to SAMHD1. For example, we have shown that MRE11 and RECQ1 are responsible for the production of DNA fragments that trigger the inflammatory response in cells deficient for SAMHD1. We can therefore imagine that blocking the activity of these enzymes could decrease the production of DNA fragments and, ultimately, the activation of innate immunity in these cells. In addition, the interferon pathway plays an essential role in the therapeutic efficacy of irradiation and certain chemotherapeutic agents such as oxaliplatin. Modulating this response could therefore be of much wider interest in anti-tumour therapy.

[Clinical evaluation of tumor-stroma ratio in pseudomyxoma peritonei from the appendix]

OBJECTIVE

To evaluate the effect of tumor-stroma ratio (TSR) on disease progression and prognosis of pseudomyxoma peritonei (PMP) from the appendix.

METHODS

The study included 30 PMP patients with complete individual patient data, who underwent cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in Beijing Shijitan Hospital. Image-Pro Plus was used to quantitatively analyze the proportion of tumor and stromal areas in hematoxylin-eosin staining pathological images, from which TSR was derived. Correlation studies were conducted to evaluate the relationships between TSR and clinicopathological features, immunohistochemical characteristics, and prognosis of PMP.

RESULTS

Among 30 PMP patients, there were 16 males (53.3%) and 14 females (46.7%), with the mean age of (54.9±2.3) years. There were 15 cases (50.0%) of low-grade mucinous carcinoma peritonei (LMCP) and high-grade mucinous carcinoma peritonei (HMCP), respectively, with vascular tumor emboli occurring in 4 cases (13.3%), nerve invasion occurring in 3 cases (10.0%), and lymphatic metastasis occurring in 4 cases (13.3%). The median peritoneal cancer index (PCI) score was 36 (range: 3-39). The median TSR was 8% (range: 2%-24%), with TSR≤10% in 19 cases (63.3%) and TSR>10% in 11 cases (36.7%). Immunohistochemistry showed that 16 cases (53.3%) had Ki67 label index ≤ 50% and 14 cases (46.7%) > 50%. The mutation rate of p53 was 56.7% and the loss rate of MMR protein was 11.8%. In addition, the expression rates of MUC2, MUC5AC, CDX2, CK7, and CK20 were 66.7%, 100.0%, 82.6%, 56.0%, and 92.3%, respectively. There were significant correlations between TSR and histopathological types, nerve invasion, Ki67 label index, and p53 mutation (P<0.05 for all). At the end of the last follow-up, 21 patients (70.0%) died and 9 patients (30.0%) survived, including 6 patients survived with tumor. The median overall survival (OS) was 12.7 months (95%CI: 10.4-11.5 months), and the 1-, 2-, and 3-year survival rates were 60.5%, 32.3%, and 27.7%, respectively. The median OS was 19.4 months (95%CI: 3.0-35.9 months) in the TSR≤10% group, versus 12.6 months (95%CI: 0.7-24.5 months) in the TSR>10% group (χ2=3.996, P=0.046).

CONCLUSION

TSR is correlated with histopathological types, tumor proliferation, invasion behaviors and prognosis of PMP, thus could be a new prognostic indicator for PMP.

[Establishment and characterization of patient derived xenograft model of malignant peritoneal mesothelioma in nude mice]

Objective: To establish patient derived xenograft (PDX) model of malignant peritoneal mesothelioma (MPM), and to identify the key characteristics of tumor biology of the model, so as to provide an experiment platform for studying the pathologic mechanisms and new therapeutic strategies for MPM. Methods: Surgically excised MPM tumor tissues were inoculated subcutaneously in BALB/c-nu/nu mice for 3 stable passages. In the 4th passage, the subcutaneous tumors were harvested under aseptic conditions, cleaned and made into MPM tumor cell homogenate. Four nude mice (two males and two females) were selected and one male and one female nude mouse were inoculated in the abdominal cavity at the dose of 100 μL, others were inoculated at a dose of 200 μL. The PDX model of MPM was established. The changes of body mass in nude mice were measured regularly, the extent of abdominal and pelvic tumors was judged by experimental peritoneal cancer index (ePCI) score, and the pathologic characteristics of tumors were analyzed. Results: The subcutaneous and abdominal animal models of MPM were successfully established. The subcutaneous tumor model grew into tumor on the 20th day, followed by a slow growth stage between the 20th and 29th day, then a rapid growth stage between the 30th and 57th day. According to the dose of tumor cells (100, 200 μL) and timing (14th and 69th days after grafting), the abdominal tumor model successfully simulated the early and late clinical stages of MPM. The HE staining results of the MPM nude mice model showed that the tumor was epithelial mesothelioma and invaded most of the organs, including liver, spleen, pancreas, mesentery. Immunohistochemical staining for calretinin, cytokeratin 5/6, WT1 and Ki-67 were positive. Whole-genome exon sequencing identified 26 and 36 high frequency gene mutations in tumors derived from the PDX model and clinical sample from patients, including 21 common gene mutations. Conclusions: The PDX model of MPM is established. The model is characterized by highly malignant tumor with rapid growth and high invasiveness.

Analyses of microRNA166 gene structure, expression, and function during the early stage of somatic embryogenesis in Dimocarpus longan Lour

MicroRNA166 (miR166) contributes to post-transcriptional regulation by binding the mRNAs of HD-ZIP III genes, which affects plant growth and development. The structural characteristics, expression, and functions of miR166 genes during the early somatic embryogenesis stage in Dimocarpus longan remain unknown. We isolated the transcripts of pri-miR166 S78 with two transcription initiation sites (TSSs) and pri-miR166 S338 with one TSS. These sequences contain potential smORFs and encode different miRNA peptides (miPEPs). Additionally, their promoters contain cis-acting elements responsive to diverse stimuli. The pre-miR166 S78 and pre-miR166 S338 expression levels were up-regulated in response to 2,4-D, abscisic acid, and ethylene. Although the expression patterns induced by hormones were similar, there were differences in the extent of the response, with pre-miR166 S338 more responsive than pre-miR166 S78. Thus, miRNA transcription and maturation are not simply linearly correlated. Moreover, pre-miR166 S78 and pre-miR166 S338 expression levels were down-regulated, whereas ATHB15 (target gene) expression was up-regulated, from the longan embryonic callus to the globular embryo stages. These results are indicative of a negative regulatory relationship between miR166 and ATHB15 during the early somatic embryogenesis stage in longan. At the same stages, miR166a.2-agomir, miR166a.2-antagomir, and miPEP166 S338 increased or decreased the expression of miR166a.2 and ATHB15, but with no consistent patterns or linear synchronization, from which we've found some reasons for it.

[Establishment of patient derived xenograft model of high-grade mucinous carcinoma peritonei accompanied with signet ring cells and identification of biological characteristics]

Objective: To establish the patient derived xenograft (PDX) model of pseudomyxoma peritonei (PMP), and identify the key characteristics of tumor biology of this model, in order to provide a reliable model for studying the pathological mechanisms and new therapeutic strategies of PMP. Methods: PMP tumor tissue was obtained from surgery and cut into pieces after washing. Then tumor pieces were implanted subcutaneously in BAL B/c-nu mice for 6 stable passages. In the 7th passage, tumor tissue was implanted orthotopically into abdomen. Subcutaneous tumor and orthotopic tumor were then homogenized to make tumor cell suspension, implanted into abdomen of 10 BAL B/c-nu mice through midline laparotomy, 100 μl for each. The key experimental parameters including body weight changes in the observation period, experimental peritoneal cancer index (ePCI) score at the autopsy, histopathological and immunohistochemical characteristics, and gene expression profiles by high-throughput whole-genome exon sequencing were detected and recorded. Results: The successful rate of established orthotopic PDX model of human PMP was 100% (10/10). The animals showed smooth body weight increases after tumor inoculation until day 27, then the body weight began to decrease steadily. Widespread tumor dissemination of PMP tumor through the whole abdomen was found by autopsy, including the diaphragm, liver, spleen, stomach, kidney, parietal peritoneum, bowel and mesenterium. Gelatinous ascites was also observed in abdominopelvic cavity. The ePCI score ranged from 5 to 9, with a 8 of median ePCI. Histopathological studies showed peritoneal mucinous carcinomatosis accompanied with signet ring cells (PMCA-S), obvious tumor cell atypia and parenchymal invasion.Immunohistochemistry showed the expressions of MUC1, MUC2, MUC5AC, CEA, CA199, CK20, CDX-2 and Ki-67 were positive, MUC6, CK7 and p53 were negative. Whole-exome sequencing identified that the most significant genetic alteration is the exon10 missense mutation c. 1621A>C of KIT gene, the mutation abundance was 89.7%. Conclusion: PDX model of PMCA-S is successfully established, which displays the characters of high-degree malignancy, high proliferation and strong aggressiveness.

[Pathological prognostic factors of pseudomyxoma peritonei]

Objective: To analyze the pathological features of pseudomyxoma peritonei (PMP) in correlation with the survival status and independent prognostic factors. Methods: One-hundred and fifty-five PMP specimens were collected at Beijing Shijitan Hospital, Capital Medical University, from 2012 to 2018. Conventional histopathological evaluation was performed to document the primary tumor site, histopathological type, lymph nodes metastasis, tumor emboli in the blood and lymph vessels, nerve invasion and cellular density. The immunohistochemical parameters including Ki-67, p53, MMR-related protein, MUC2 and MUC5AC were analyzed. Clinical follow-up data were reviewed to correlate with pathological prognostic factors using Kaplan-Meier estimator and Cox proportional hazards regression model for univariate and multivariate analysis. Results: Among 155 PMP patients, there were 77 males and 78 females. There were 98 cases (63.2%) of low-grade peritoneal mucinous carcinomatosis, 49 cases (31.6%) of high-grade peritoneal mucinous carcinomatosis, 8 cases (5.2%) of high-grade mucinous carcinoma peritonei with signet ring cells; only 15 cases (9.7%) with lymph node metastasis; 18 cases (11.6%) with tumor emboli in the blood and lymph vessels; 8/126 (6.3%) were positive dMMR; 100 cases (64.5%) had Ki-67 label index <50%, and 56 cases(36.1%) presented with mutant type p53. Univariate analysis revealed 11 survival-related pathological parameters including gender, age, primary tumor site, histopathological type, lymph node metastasis, tumor emboli in the blood and lymph vessels, nerve invasion, cellular density, Ki-67 label index rate, p53 and dMMR. Multivariate analysis identified 4 independent prognostic factors including the histopathological type (HR 59.78, P<0.01), lymph node metastasis (HR 3.74, P=0.028), nerve invasion (HR 7.81, P=0.007) and dMMR (HR 9.82, P<0.01). Conclusions: Histopathological type is the most important prognostic factor of PMP with dMMR as an independent molecular prognostic indicator.

Removal of sulfonamides from wastewater in the UV/TiO2 system: effects of pH and salinity on photodegradation and mineralization

The effects of salinity on the photodegradation and mineralization of sulfonamides in the UV/TiO₂ system were investigated. The goals of this study were to analyze the effects of pH and salinity on the sulfonamide concentration and total organic carbon (TOC) during the removal of sulfonamides in a UV/TiO₂ system. Four sulfonamides - sulfadiazine (SDZ), sulfamethizole (SFZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) - were selected as parent compounds. The photodegradation and mineralization rates of sulfonamides in the UV/TiO₂ system satisfy pseudo-first-order kinetics. Direct photolysis degraded sulfonamides but sulfonamides cannot be mineralized. The photodegradation and mineralization rate constants in all experiments followed the order pH 5 > pH 7 > pH 9. At pH 5, the mineralization rate constants of SMX, SFZ, SDZ and STZ were 0.015, 0.009, 0.012 and 0.011 min^-1, respectively. The addition of NaCl inhibited the mineralization of the four tested sulfonamides more than it inhibited their photodegradation. The inhibitory effect of chloride ions on the removal of sulfonamides in the UV/TiO₂ system was attributed to the scavenging by chloride ions of hydroxyl radicals (HO•) and holes and the much lower reactivity of chlorine radicals thus formed, even though the chlorine radicals were more abundant than HO•.

[Performance of matrix assisted laser desorption ionization time of flight biotyper system in clinical bacteria identification]

Objective: To evaluate the performance of MALDI Biotyper system in identification of clinically isolated pathogens so as to provide a new rapid identification method. Methods: Total 21 270 pathogens strains, isolated from the First Affiliated Hospital of Fujian Medical Universityduring Nov. 2015 to Dec. 2016, were identified by VITEK-Ⅱ, API and MALDI Biotyper system, respectively.The isolated strains were confirmed by DNA sequencing. Results: The identification of common bacteria with MALDI Biotyper and phenotypic system is highly consistent (>95% and >90%). Among 43 strains of anaerobic bacteria, MALDI Biotyper could identify 90.7% bacteria to species level and 97.7% bacteria to genus level with the statistical significance(χ(2)=6.76, P<0.01), while phenotypic system only identified 65.1% bacteria to species and 69.8% bacteria to genus. Also, no statistical significance was shown for Trichosporon and Candida(P>0.05). MALDI Biotyper could identify 76% filamentous fungi and all of Actinomycetes, Nocardia, Mycobacterium and Legionella to genus level. Conclusions: MALDI Biotyper is an easy-performed, sensitive method for the identification of clinically isolated pathogens. Additionally, the pretreatment and reference database has the effect on identification.

Mycoplasma pneumoniae- associated encephalitis complicated by cerebral salt wasting syndrome

Cerebral salt wasting syndrome can occur in children with encephalitis. Clinicians should be aware of hyponatremia in patients who develop polyuria with the signs of dehydration and deteriorated consciousness. Furthermore, patients who present with status epilepticus or who are suspected to have high intracranial pressure may have an increased risk of cerebral salt wasting syndrome.

TRIg: a robust alignment pipeline for non-regular T-cell receptor and immunoglobulin sequences

BACKGROUND

T cells and B cells are essential in the adaptive immunity via expressing T cell receptors and immunoglogulins respectively for recognizing antigens. To recognize a wide variety of antigens, a highly diverse repertoire of receptors is generated via complex recombination of the receptor genes. Reasonably, frequencies of the recombination events have been shown to predict immune diseases and provide insights into the development of immunity. The field is further boosted by high-throughput sequencing and several computational tools have been released to analyze the recombined sequences. However, all current tools assume regular recombination of the receptor genes, which is not always valid in data prepared using a RACE approach. Compared to the traditional multiplex PCR approach, RACE is free of primer bias, therefore can provide accurate estimation of recombination frequencies. To handle the non-regular recombination events, a new computational program is needed.

RESULTS

We propose TRIg to handle non-regular T cell receptor and immunoglobulin sequences. Unlike all current programs, TRIg does alignments to the whole receptor gene instead of only to the coding regions. This brings new computational challenges, e.g., ambiguous alignments due to multiple hits to repetitive regions. To reduce ambiguity, TRIg applies a heuristic strategy and incorporates gene annotation to identify authentic alignments. On our own and public RACE datasets, TRIg correctly identified non-regularly recombined sequences, which could not be achieved by current programs. TRIg also works well for regularly recombined sequences.

CONCLUSIONS

TRIg takes into account non-regular recombination of T cell receptor and immunoglobulin genes, therefore is suitable for analyzing RACE data. Such analysis will provide accurate estimation of recombination events, which will benefit various immune studies directly. In addition, TRIg is suitable for studying aberrant recombination in immune diseases. TRIg is freely available at https://github.com/TLlab/trig .

[A clinical analysis for sudden sensorineural hearing loss withcontralateral sensorineural hearing loss]

Objective:To analyze the clinical characteristics and prognosis,and to learn the impact factors of patients with sudden sensorineural hearing loss with contralateral sensorineural hearing loss(SSHLwCSHL).Method:Clinical data of 63 cases of patients with SSHLwCSHL were analyzed systematically,including all the clinical manifestations,audiologic characteristics and the effect assessment,and compared with that of unilateral sudden sensorineural hearing loss(USSHL) and bilateral sudden sensorineural hearing loss(BSSHL).Base on those,we summarized comprehensively the development and prognosis characteristics of the disease.Result:The incidence of SSHLwCSHL was 8.3 percent of overall patients with SSNHL.SSHLwCSHL occurs more commonly in male patients,with more vertigo,diabetes mellitus,and lipid panel abnormalities compared with other groups.Hearing curve and the degree of hearing loss of the prevalence ear of SSHLwCSHL was statistically significant difference with USSHL(P<0.05).Most common reason of the contralateral hearing loss was sudden sensorineural hearing loss(49%),and 59% patients of SSHLwCSHL suffered hearing loss of other ear after 2-10 years after contralateral hearing loss.The total effective rate was 14.3%,1 in 63 patients cured,1 excellence and 6 effective.The total effective rate was 9.5% in patients with severe or profound sensorineural hearing loss in the contralateral ear,which was lower than that of patients with moderate and moderately severe sensorineural hearing loss in the contralateral-ear(P=0.021).Conclusion:SSHLwCSHL has complex condition.The prognosis for improvement is poor.Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.

Obtaining long 16S rDNA sequences using multiple primers and its application on dioxin-containing samples

Background

Next-generation sequencing (NGS) technology has transformed metagenomics because the high-throughput data allow an in-depth exploration of a complex microbial community. However, accurate species identification with NGS data is challenging because NGS sequences are relatively short. Assembling 16S rDNA segments into longer sequences has been proposed for improving species identification. Current approaches, however, either suffer from amplification bias due to one single primer or insufficient 16S rDNA reads in whole genome sequencing data.

Results

Multiple primers were used to amplify different 16S rDNA segments for 454 sequencing, followed by 454 read classification and assembly. This permitted targeted sequencing while reducing primer bias. For test samples containing four known bacteria, accurate and near full-length 16S rDNAs of three known bacteria were obtained. For real soil and sediment samples containing dioxins in various concentrations, 16S rDNA sequences were lengthened by 50% for about half of the non-rare microbes, and 16S rDNAs of several microbes reached more than 1000 bp. In addition, reduced primer bias using multiple primers was illustrated.

Conclusions

A new experimental and computational pipeline for obtaining long 16S rDNA sequences was proposed. The capability of the pipeline was validated on test samples and illustrated on real samples. For dioxin-containing samples, the pipeline revealed several microbes suitable for future studies of dioxin chemistry.

Association between MYC rs9642880[T] allele and bladder cancer risk: a meta-analysis

A single nucleotide polymorphism of MYC rs9642880 (G>T) at the 8q24.1 locus is thought to be associated with bladder cancer risk based on the results of genome-wide association studies, but the results remain inconclusive. To assess the association between rs9642880[T] allele and bladder cancer risk, we performed this meta-analysis including 18 case-control studies and involving 23,084 cases and 97,164 controls. Electronic searches for publications were conducted to determine the association between this variant and prostate cancer in several databases. The last search update was August 4, 2014. We used odds ratios and 95%CIs to evaluate the strength of the associations. The overall results suggested that the rs9642880[T] allele was associated with bladder cancer susceptibility (T vs G, odds ratio = 1.18, 95%CI = 1.14-1.22). In subgroup analysis by ethnicity and source of controls, the risk remained significant. The present meta-analysis suggests that the MYC rs9642880[T] allele is significantly associated with bladder cancer risk.

A technique for measuring dynamic friction coefficient under impact loading

We develop a novel setup based on the split Hopkinson pressure bar technique to test the dynamic friction coefficient under impact loading. In the setup, the major improvement is that the end of the incident bar near the specimen is wedge-shaped, which results in a combined compressive and shear loading applied to the specimen. In fact, the shear loading is caused by the interfacial friction between specimen and bars. Therefore, when the two loading force histories are measured, the friction coefficient histories can be calculated without any assumptions and theoretical derivations. The geometry of the friction pairs is simple, and can be either cuboid or cylindrical. Regarding the measurements, two quartz transducers are used to directly record the force histories, and an optical apparatus is designed to test the interfacial slip movement. By using the setup, the dynamic friction coefficient of PTFE/aluminum 7075 friction pairs was tested. The time resolved dynamic friction coefficient and slip movement histories were achieved. The results show that the friction coefficient changes during the loading process, the average data of the relatively stable flat plateau section of the friction coefficient curves is 0.137, the maximum normal pressure is 52 MPa, the maximum relative slip velocity is 1.5 m/s, and the acceleration is 8400 m(2)/s. Furthermore, the friction test was simulated using an explicit FEM code LS-DYNA. The simulation results showed that the constant pressure and slip velocity can both be obtained with a wide flat plateau incident pulse. For some special friction pairs, normal pressure up to a few hundred MPa, interfacial slip velocities up to 10 m/s, and slip movement up to centimeter-level can be expected.

Verification of wild-type EGFR status in non-small cell lung carcinomas using a mutant-enriched PCR on selected cases

EGFR genotyping is required for targeted therapy of lung adenocarcinoma. Because a false-negative result might prevent a patient from receiving appropriate targeted therapies, it is desirable to recheck equivocal results of EGFR genotyping. A cohort of 346 lung cancers was tested with a commercial kit for EGFR mutations; nine of the cases had upward real-time amplification curves at late cycles. They were also investigated using mutant-enriched PCR with peptide nucleic acid-locked nucleic acid (PNA-sequencing). Six of the nine equivocal cases harbored EGFR mutations. These cases likely had a small amount of mutant DNA near the detection limit of the commercial kit. Twenty nonequivocal, wild-type cases were reconfirmed using PNA-sequencing. We noticed a College of American Pathologists proficiency test material that showed a suspicious upward curve and eventually proved to have an H773_V774insPH in exon 20, for which a specific primer was not designed in the commercial kit. Further study using cloned DNA fragments showed that the upward curve most likely resulted from cross-reaction between similar, but nonidentical, sequences. It is desirable to keep the number of false-negative results as low as possible, but rechecking all wild-type cases is impractical. The late upward curves we observed helped identify suspicious cases for rechecking. A second method, such as PNA-sequencing, is recommended to verify wild-type cases.

Enhancement of the Schottky barrier height of Au/ZnO nanocrystal by zinc vacancies using a hydrothermal seed layer

Various seed layers were prepared on a Si substrate using the sol-gel (SG) or hydrothermal (HT) method and then ZnO nanocrystal was grown on the seed layer by an HT process. Au/ZnO nanocrystal Schottky diodes (SDs) were fabricated to study the effects of various seed layers on the electrical properties of Au/ZnO SDs. The observations showed that large numbers of Zn vacancies were present near the interface of Au/ZnO with an HT seed layer. The Zn vacancy plays an acceptor-like role, which raises the barrier height of the Au/ZnO SDs to 0.79 eV with a rectifying ratio of more than 8000. Hence, a non-surface-treated Au/ZnO SD was achieved as compared to those of other reported oxygen-plasma treated surfaces. In contrast, oxygen vacancies appear near the interface of Au/ZnO with an SG seed layer. The O vacancy plays a donor-like role, which reduces the barrier height of Au/ZnO, leading to an Ohmic behavior in the I-V characteristics. Zn out-diffusion is found during Au evaporation by of x-ray photoelectron spectroscopy measurements.

Clinical and Prognostic Significance of Protocadherin-10 (PCDH10) Promoter Methylation in Bladder Cancer

Objective:

To investigate the clinical and prognostic significance of protocadherin-10 (PCDH10) promoter methylation in serum-derived DNA from patients with bladder cancer.

Methods:

PCDH10 promoter methylation status was determined using methylation-specific polymerase chain reaction of DNA extracted from serum of patients with bladder cancer, and age- and sex-matched controls. Clinical and pathological details of bladder cancer were recorded.

Results:

PCDH10 promoter methylation was detected in 59/117 (50.4%) of patients with bladder cancer, and none of 37 (0%) controls. Methylation was significantly associated with advanced stage (T2 - T4), high grade (G3), tumour recurrence and larger tumour size (> 3 cm). In addition, methylation was associated with significantly worse survival and was an independent predictor of overall survival.

Conclusion:

Serum-based analysis of PCDH10 promoter methylation may represent a useful noninvasive biomarker of malignant behaviour and outcome in bladder cancer.

The significance of fragile histidine triad protein as a molecular prognostic marker of bladder urothelial carcinoma

OBJECTIVES

The role and clinical significance of fragile histidine triad (FHIT) gene in the pathogenesis of bladder urothelial carcinoma (UC) and the potential of Fhit protein as a prognostic biomarker for UC were investigated.

METHODS

FHIT expression was determined according to semiquantitative immunohistochemical staining for Fhit protein levels in normal bladder and bladder UC tissues. Associations between FHIT expression, clinicopathological features and survival were evaluated.

RESULTS

This study evaluated 42 cases of normal bladder and 125 cases of bladder UC; bladder UC cases had a median follow-up of 53.5 months. Immuno histochemistry showed that 95.2% of normal cases and 47.2% of bladder UC cases, respectively, were positive for Fhit protein; this difference was statistically significant. There was a significant association between negative FHIT expression in bladder UC and advanced tumour stage, high pathological grade, large tumour size, tumour recurrence and reduced survival time, but no association with age, gender, tumour number or tumour shape.

CONCLUSIONS

The FHIT gene may have an important role in the pathogenesis of bladder UC and was expressed at lower levels in bladder UC compared with normal bladder tissue. Using Fhit protein as a biomarker could provide important information about patient prognosis.

A technique for combined dynamic compression-shear test

It is critically important to study the dynamic response of materials under a combined compression-shear loading for developing constitutive laws more accurately and fully. We present a novel technique to achieve the combined compression and shear loadings at high strain rates. The main apparatus consists of a strike bar, an incident bar, and two transmission bars. The close-to-specimen end of the incident bar is wedge-shaped with 90°. In each experiment, there are two identical specimens, respectively, agglutinated between one side of the wedge and one of transmission bars. When a loading impulse travels to specimens along the incident bar, because of the special geometrical shape, the specimen-incident bar interface gets an axial and a transverse velocity. Specimens endure a combined compression-shear loading at high strain rates. The compression stress and strain of the specimens are deduced from signals recorded by strain gages mounted on the bars. The shear stress is measured by two piezoelectric transducers of quartz (Y-cut with rotation angle 17.7°) embedded at the close-to-specimen end of transmission bars; the shear strain is measured with a novel optical technique, which is based on the luminous flux method. An analytic model was proposed and validated by the numerical simulations. The simulation results yield good agreement with the analytic results. The proposed technique was then validated through experiments carried out on lead specimens, by comparing experimental results with that of the split Hopkinson pressure bar experiments.

Clinical Significance of CDH13 Promoter Methylation in Serum Samples from Patients with Bladder Transitional Cell Carcinoma

H-cadherin (CDH13; also known as T-cadherin), which functions as a tumour suppressor, is frequently silenced by promoter methylation in human cancers including bladder transitional cell carcinoma (TCC). This study investigated the clinical significance of methylation of the CDH13 gene promoter in serum from patients with bladder TCC. Methylation status of CDH13 in serum samples from 127 patients with primary bladder TCC and 41 healthy volunteers (controls) was examined by methylation-specific polymerase chain reaction. CDH13 methylation was found in 39 patients with bladder TCC (30.7%) but in no controls. CDH13 methylation was significantly associated with advanced tumour stage, high-grade tumour, large tumour size, tumour recurrence and poor prognosis. The results suggested that CDH13 methylation in serum may be a potential predictive biomarker for malignancy in bladder TCC, and an independent pre-therapeutic predictor of outcome. Demonstration of CDH13 methylation in serum may facilitate in the prediction of which patients require more aggressive additional post-operative systemic therapy.

Butanol Production by a Butanol-Tolerant Strain of Clostridium acetobutylicum in Extruded Corn Broth

By employing serial enrichment, a derivative of Clostridium acetobutylicum ATCC 824 was obtained which grew at concentrations of butanol that prevented growth of the wild-type strain. The parent strain demonstrated a negative growth rate at 15 g of butanol/liter, whereas the SA-1 mutant was still able to grow at a rate which was 66% of the uninhibited control. SA-1 produced consistently higher concentrations of butanol (from 5 to 14%) and lower concentrations of acetone (12.5 to 40%) than the wild-type strain in 4 to 20% extruded corn broth (ECB). Although the highest concentration of butanol was produced by SA-1 and the wild-type strain in 14% ECB, the best solvent ratio with respect to optimizing butanol and decreasing acetone occurred between 4 and 8% ECB for SA-1. SA-1 demonstrated higher conversion efficiency to butanol than the wild-type strain at every concentration of ECB tested. Characterization of the wild-type and SA-1 strain in 6% ECB demonstrated the superiority of the latter in terms of growth rate, time of onset of butanol production, carbohydrate utilization, pH resistance, and final butanol concentration in the fermentation broth.

Effect of extracorporeal shock wave therapy on the biochemical composition and metabolic activity of tenocytes in normal tendinous structures in ponies

REASONS FOR PERFORMING STUDY

Extracorporeal shockwave therapy (ESWT) has recently been introduced as a new therapy for tendon injuries in horses, but little is known about the basic mechanism of action of this therapy.

OBJECTIVES

To study the effect of ESWT on biochemical parameters and tenocyte metabolism of normal tendinous structures in ponies.

METHODS

Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor tendon (SDFT) 6 weeks prior to sample taking, and at the mid-metacarpal region (ET) and the insertion on the extensor process of the distal phalanx (EP) of the common digital extensor tendon 3 h prior to tendon sampling. In all animals one front leg was treated and the other front leg was used as control. After euthanasia, tendon explants were harvested aseptically for in vitro cell culture experiments and additional samples were taken for biochemical analyses.

RESULTS

In the explants harvested 3 h after treatment, glycosaminoglycan (GAG) and protein syntheses were increased (P<0.05). The synthesis of all measured parameters was decreased 6 weeks after ESWT treatment. Biochemically, the level of degraded collagen was increased 3 h after treatment (P<0.05). Six weeks after treatment, there was a decrease of degraded collagen and GAG contents. DNA content had not changed in either tendon samples or explants after culturing.

CONCLUSIONS

ESWT causes a transient stimulation of metabolism in tendinous structures of ponies shortly after treatment. After 6 weeks metabolism has decreased significantly and GAG levels are lower than in untreated control limbs.

POTENTIAL RELEVANCE

The stimulating short-term effect of ESWT might accelerate the initiation of the healing process in injured tendons. The long-term effect seems less beneficial. Further research should aim at determining the duration of this effect and at assessing its relevance for end-stage tendon quality.

The severity of Streptococcus pyogenes infections in children is significantly associated with plasma levels of inflammatory cytokines

Cytokines are intimately involved with the innate and adaptive immune response to bacterial infections. This study was designed to determine the expression of inflammatory cytokines in children by the severity of Streptococcus pyogenes (group A Streptococcus [GAS]) infections. The study population consisted of 16 invasive, 20 noninvasive, and 24 pharyngeal colonization, and 21 healthy controls. All children underwent the laboratory tests and cytokine measurement. GAS isolates were analyzed for emm gene typing. Patients with invasive GAS diseases had significantly higher interferon (IFN)-gamma, interleukin (IL)-1beta, IL-6, IL-8, IL-10, and IL-18 than those with noninvasive diseases, colonization, and healthy controls. There was no difference in tumor necrosis factor (TNF)-alpha, IL-12, and IL-2 levels among the groups. Elevated white blood cell counts and levels of C-reactive protein and C3 were detected only in patients with invasive diseases. emm1 and emm12 predominated in invasive disease and colonization. Children with invasive GAS infections exhibited significant up-regulation of plasma levels of IFN-gamma, IL-1beta, IL-6, IL-8, IL-10, and IL-18, and suppression of TNF-alpha and IL-12 during the acute phase of their illness. An exuberant cytokine response was associated with the severity of illness.

Preliminary study on wilcoxon learning machines

As is well known in statistics, the resulting linear regressors by using the rank-based Wilcoxon approach to linear regression problems are usually robust against (or insensitive to) outliers. This motivates us to introduce in this paper the Wilcoxon approach to the area of machine learning. Specifically, we investigate four new learning machines, namely Wilcoxon neural network (WNN), Wilcoxon generalized radial basis function network (WGRBFN), Wilcoxon fuzzy neural network (WFNN), and kernel-based Wilcoxon regressor (KWR). These provide alternative learning machines when faced with general nonlinear learning problems. Simple weights updating rules based on gradient descent will be derived. Some numerical examples will be provided to compare the robustness against outliers for various learning machines. Simulation results show that the Wilcoxon learning machines proposed in this paper have good robustness against outliers. We firmly believe that the Wilcoxon approach will provide a promising methodology for many machine learning problems.

Immune responses of pigs to commercialized emulsion FMD vaccines and live virus challenge

The immune response to structural and non-structural proteins (NSPs) was studied on sequential serum samples in swine from O/Taiwan/97 FMDV challenge studies, outbreaks and after vaccination. The results showed that pigs vaccinated with a commercial vaccine prior to or after infection maintained high neutralizing antibody titers with gradual decline from peak titers over the duration of this study. However, neutralizing antibody titers in non-vaccinated pigs only reached moderate levels 2-4 weeks post infection and remained low thereafter. For the 3B and 3ABC NSP antibody ELISA responses, there were gradually decreasing levels of NSP antibody over time. In multiple vaccinations, all pigs showed significant increases in neutralizing antibodies after booster vaccination. For the 3B NSP antibody ELISA after vaccination, the mean S/P ratios for pigs vaccinated with all three FMD vaccines were all below the 0.23 cut-off value set by the manufacture, but some sera from individual vaccinated pigs gave results above this cut-off after primary or secondary vaccination. However, with the 3ABC NSP antibody ELISA, all sera from vaccinated pigs had negative results for NSP antibody for all time points.

Comparison of sensitivity and specificity in three commercial foot-and-mouth disease virus non-structural protein ELISA kits with swine sera in Taiwan

Three commercialized ELISA kits for the detection of antibodies to the non-structural proteins (NSPs) of FMD virus were compared, using sera from uninfected, vaccinated, challenged and naturally infected pigs. The kinetics of the antibody response to NSPs was compared on sequential serum samples in swine from challenge studies and outbreaks. The results showed that ELISA A (UBI) and ELISA B (CEDI) had better sensitivity than that of the 3ABC recombinant protein-based ELISA C (Chekit). The peak for detection of antibodies to NSPs in ELISA C was significantly delayed in sera from natural infection and challenged swine as compared to the ELISA A and B. The sensitivity of the three ELISAs gradually declined during the 6-month post-infection as antibodies to NSP decline. ELISA kits A and B detected NSP antibody in 50% of challenged pigs by the 9-10th-day and 7-8th-day post-challenge, respectively. ELISA B and C had better specificity than ELISA A on sequential serum samples obtained from swine immunized with a type O FMD vaccine commercially available in Taiwan. Antibody to NSPs before vaccination was not detected in swine not exposed to FMD virus, however, antibody to NSPs was found in sera of some pigs after vaccination. All assays had significantly lower specificity when testing sera from repeatedly vaccinated sows and finishers in 1997 that were tested after the 1997 FMD outbreak. However, when testing sera from repeatedly vaccinated sows or finishers in 2003-2004, the specificity for ELISAs A, B and C were significantly better than those in 1997. This effect was less marked for ELISA A. The ELISA B was the best test in terms of the highest sensitivity and specificity and the lowest reactivity with residual NSP in vaccinates.

Relationship between chlorine consumption and chlorination by-products formation for model compounds

The objective of this research is to investigate the relationship between chlorine decay and the formations of disinfection by-products (DBP), including trichloromethane (TCM) and chloroacetic acid (CAA) in the presence of four model compounds, i.e., resorcinol, phloroglucinol, p-hydroxybenzoic acid, and m-hydroxybenzoic acid. The chlorine degradation in model compounds with OH and/or COOH functional groups were rapid after chlorination. The TCM yields of carboxylic group substituted compounds (3-hydroxybenzoic acid [3-HBA], 4-hydroxybenzoic acid [4-HBA]) were found to be lower than that of the m-dihydroxy substituted compounds. Phloroglucinol, with one more OH substitution group than resorcinol, tends to form significant amounts of CAA after chlorination. However, it was observed that with the COOH substitution of 3-HBA and 4-HBA tend to exhibit more CAA formation potential than resorcinol. The developed parallel second and first-order reaction model for chlorine demand has been successfully utilized for TCM, CAA and DBP formation modeling. A high correlation between CAA and TCM was observed for the model compounds.

San-Huang-Xie-Xin-Tang attenuates inflammatory responses in lipopolysaccharide-exposed rat lungs

In this study, the potential anti-inflammatory effect of San-Huang-Xie-Xin-Tang (SHXT) and its main component baicalin on LPS-induced lung injury were investigated and compared to the profile of dexamethasone (DEXA) in a pre-clinical animal model. Post-treatment with SHXT (75 mg/kg), baicalin (1.5 mg/kg) and DEXA (0.5 mg/kg), significantly inhibited LPS-induced hypotension, lung edema and acute survival rates. Western blotting analysis results indicated that all of them significantly inhibited LPS-induced iNOS, TGF-beta, p38MAPK, and ICAM-1 expressions in the lung tissues. Results from ELISA analysis showed that SHXT, baicalin and DEXA all decreased plasma levels of IL-1beta, TNF-alpha, and MCP-1 caused by LPS. Based on these findings, SHXT and baicalin decreased plasma concentrations of IL-1beta, TNF-alpha, MCP-1, and expressions of TGF-beta, ICAM-1, phosphorylated p38 MAPK, and iNOS, which were associated with lung injury and lethality. These evidences indicated that SHXT and baicalin showed strong anti-inflammatory activity, similar to that observed for DEXA, and therefore implicated that herbal SHXT might be therapeutically useful for the treatment of endotoxic lung injury.

Extracellular Matrix Compositon of the Equine Superficial Digital Flexor Tendon: Relationship with Age and Anatomical Site

The objectives of the present study were to test the hypotheses that: (1) the composition of the extracellular matrix of the equine superficial digital flexor tendon (SDFT) shows great functional similarities with articular cartilage, i.e. that significant differences exist in biochemical composition of differently loaded areas (which in the case of tendons may be more apparent as tendon shows more obvious differences than cartilage); and (2) that, as in articular cartilage, no substantial alterations in biochemical composition take place during ageing once adulthood has been attained. Tendon samples were taken from 60 adult slaughter horses from a central area at cross-section in the mid-metacarpal region and at the height of the proximal sesamoid bones (sesamoid region) of the SDFT. Contents of collagenous and non-collagenous components were determined. None of the parameters were correlated with age in either region, except for a significant increase in pentosidine cross-links with age in the sesamoid region. Between the two anatomical regions, there were significant differences in all variables, except for hydroxylysylpyridinoline cross-links. It was concluded that in the equine SDFT, similar to articular cartilage, most molecular parameters are not influenced by age in mature horses, indicating a low remodelling rate. Tendon composition is clearly different between regions, apparently reflecting different specific modes of biomechanical loading at the points sampled.

Efficacy of foot-and-mouth disease vaccine in pigs with single dose immunization

Two experiments were conducted to demonstrate the efficacy of a commercial foot-and-mouth disease (FMD) vaccine in pigs born to well-vaccinated sows at various ages with a single injection under field conditions. The first experiment showed that single dose vaccination of pigs could be conducted at an age younger than 10 weeks. Second experiment demonstrated that pigs vaccinated once at the age of 8 weeks had mean serum neutralization (SN) titer of 1.89+/-0.95 log(10)SN(50) with full protection by challenge test at the age of 24 weeks. Results indicate that the most appropriate age for single dose FMD vaccination in pigs born to well-vaccinated sows would be at 8 weeks.

Appendicitis in infancy

Acute appendicitis is the most common cause of abdominal pain requiring surgery in children. But it is an uncommon entity in young children and rare in infants. During a 10-year period, between January 1991 and December 2000, 7 infants (age from 17 days to 8 months) were treated for acute appendicitis at Changhua Christian Hospital. All of the preoperative symptoms and signs, the duration between admission and operation, pathology reports, and laboratory data were reviewed. There were no specific clinical signs and symptoms. The duration between admission and operation ranged from 2 hours to 5 days (mean: 31.4 hours). The pathology reports revealed 3 were gangrenous, 3 were gangrenous with perforation and one was suppurative. There was one death. Pseudomonas aeruginosa was cultured from blood, ascites, bile or stool in 6 cases (85.7%). Early diagnosis of acute appendicitis in infants is still difficult. Although the mortality has declined, the morbidity still remains high. The high percentage of infection by Pseudomonas aeruginosa should be further evaluated in infantile appendicitis.

Optimization of foot-and-mouth disease vaccination protocols by surveillance of neutralization antibodies

An appropriate immunization program for pigs in a foot-and-mouth disease (FMD) endemic area was proposed based on data analysis obtained from serological surveillance in Taiwan, after an intensive vaccination program. To provide an adequate passive immunity for piglets, gilts that have completed two basic vaccinations must be boosted once before breeding. To achieve an efficient response to the FMD vaccine for piglets born to well vaccinated sows, vaccination need to be delayed until 10-12 weeks of ages for the first immunization, followed by a boost 4 weeks later.

Association between serum inflammatory cytokines and disease activity in juvenile idiopathic arthritis

Circulating interleukin-1beta (IL-1beta), IL-6, tumour necrosis factor-alpha (TNF-alpha), osteocalcin, and conventional parameters of inflammation were examined serially in 14 children with juvenile idiopathic arthritis (JIA) to determine any correlation with the disease activity. Serum IL-1beta was undetectable in all JIA patients. Serum IL-6, white blood cell counts, platelet counts, erythrocyte sedimentation rate and C-reactive protein levels were significantly elevated in the active phase of JIA, whereas hemoglobin levels were significantly lower. Osteocalcin levels were decreased and TNF-alpha increased in active JIA status, but these differences showed no statistical significance. We concluded that inflammatory cytokines play an important role in JIA. Monitoring IL-6 in children with JIA is useful in determining disease activity and response to therapy. These findings confirm earlier reports.

Studies of silyl-accelerated 1,5-hydrogen migrations in vinylcyclopropanes

Thermal 1,5-hydrogen (retro-ene) rearrangements of 1-silylmethylated 2-vinylcyclopropanes have been studied. cis-1-Silylmethyl-2-vinylcyclopropanes 17 and 19 undergo facile 1,5-hydrogen transposition upon mild thermolysis in benzene or toluene solution (80-110 degrees C) to give nearly quantitative yields of ring-opened 1-silyl-1,4-diene products. These reactions occur at temperatures at least 100 degrees C lower than those of the nonsilylated substrates. The silicon center and its ligands influence both the rate and stereoselectivity of diene formation, with the triphenylsilyl substrate providing the fastest reaction and highest (exclusive) stereoselectivity in forming the diene, regardless of the E/Z geometry of the vinylcyclopropane. The trimethylsilyl and triethoxysilyl compounds (19b and 19c) rearrange more slowly and with lower stereoselectivity. It is proposed that the rearrangement process takes place via a concerted suprafacial migration by one of two diastereotopic methylene hydrogens through a transition state having the silyl-carbon bond antiperiplanar to the breaking C-C bond of the cyclopropane ring. This conformational arrangement leads to weakening of the cyclopropane ring bond through orbital hyperconjugation, which facilitates the hydrogen transfer. The corresponding trans-1-silylmethyl-2-vinylcyclopropanes are thermally stable under these conditions. In contrast, cis-1-stannylmethyl-2-vinylcyclopropanes 19d,e undergo loss of the stannyl group at room temperature to afford a ring-opened 1,5-diene product 25 through a process that may take place by initial 1,5-stannyl migration.

Protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin B(1)-induced genotoxicities

To evaluate the protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin (AF) B(1)-induced toxicities, the effects of these flavonoids on the genotoxicities and oxidation of benzo[a]pyrene and AFB(1) were studied in C57BL/6J mice. Baicalein and wogonin reduced benzo[a]pyrene and AFB(1) genotoxicities as monitored by the umuC gene expression response in Salmonella typhimurium TA1535/pSK1002. Baicalein added in vitro decreased liver microsomal benzo[a]pyrene hydroxylation (AHH) activity with an ic(50) of 33.9 +/- 1.4 microM at 100 microM benzo[a]pyrene. Baicalein also inhibited AFQ(1) and AFB(1)-epoxide formation from AFB(1) (50 microM) oxidation (AFO) with ic(50) values of 22.8 +/- 1.4 and 5.3 +/- 0.8 microM, respectively. However, the in vitro inhibitory effects of wogonin on AHH and AFO activities in liver microsomes were less than those of baicalein as inhibition by 500 microM wogonin was only about 51-65%. Treatment of mice with liquid diets containing 5 mM baicalein and wogonin resulted in 22 and 49% decreases in hepatic AHH activities, respectively. Baicalein treatment resulted in 39 and 32% decreases in AFQ(1) and AFB(1)-epoxide formation from liver microsomal AFO, respectively. Wogonin treatment resulted in 39 and 47% decreases in AFQ(1) and AFB(1)-epoxide formation, respectively. A 1-week pretreatment with wogonin significantly decreased hepatic DNA adduct formation in mice treated with 200 mg/kg of benzo[a]pyrene via gastrogavage. These in vitro and in vivo effects suggested that baicalein and wogonin might have beneficial effects against benzo[a]pyrene- and AFB(1)-induced hepatic toxicities and that wogonin had a stronger protective effect in vivo.

Cloning, sequencing, heterologous expression, purification, and characterization of adenosylcobalamin-dependent D-ornithine aminomutase from Clostridium sticklandii

D-Ornithine aminomutase from Clostridium sticklandii catalyzes the reversible rearrangement of d-ornithine to (2R,4S)-2,4-diaminopentanoic acid. The two genes encoding d-ornithine aminomutase have been cloned, sequenced, and expressed in Escherichia coli. The oraS gene, which encodes a protein of 121 amino acid residues with M(r) 12,800, is situated upstream of the oraE gene, which encodes a protein of 753 amino acid residues with M(r) 82,900. The holoenzyme appears to comprise a alpha(2)beta(2)-heterotetramer. OraS shows no significant homology to other proteins in the Swiss-Prot data base. The deduced amino acid sequence of OraE includes a conserved base-off/histidine-on cobalamin-binding motif, DXHXXG. OraE was expressed in E. coli as inclusion bodies. Refolding experiments on OraE indicate that the interactions between OraS and OraE and the binding of either pyridoxal phosphate or adenosylcobalamin play important roles in refolding process. The K(m) values for d-ornithine, 5'-deoxyadenosylcobalamin (AdoCbl), and pyridoxal 5'-phosphate (PLP) are 44.5 +/- 2.8, 0.43 +/- 0.04, and 1.5 +/- 0.1 microm, respectively; the k(cat) is 6.3 +/- 0.1 s(-1). The reaction was absolutely dependent upon OraE, OraS, AdoCbl, PLP, and D-ornithine being present in the assay; no other cofactors were required. A red-shift in UV-visible absorption spectrum is observed when free adenosylcobinamide is bound by recombinant D-ornithine aminomutase and no significant change in spectrum when free adenosylcobinamide is bound by mutant OraE-H618G, demonstrating that the enzyme binds adenosylcobalamin in base-off/histidine-on mode.

Effects of retinoic acid on pre-implantation embryo development in mice

BACKGROUND

In a previous study we had investigated the effect of in utero retinoic acid (RA) exposure on early post-implantation development at the blastocyst stage before implantation and immediately after implantation to understand the possible roles of RA in embryogenesis. The results showed that excess RA affected early post-implantation embryogenesis adversely. We designed the present study to investigate the effect of in utero RA exposure on pre-implantation embryos.

METHODS

In the prospective animal study, pregnant female mice received early pre-implantation peanut oil with 50 mg/kg t-RA or 100 mg/kg t-RA by oral gavage on the morning of day 1 and 2 or late pre-implantation exposure on the night of day 2 and morning of day 3 of gestation. Mice were sacrificed late in day 3. The number and morphology embryos were recorded.

RESULTS

All mice given oral RA were sacrificed on the same day. The mean number of embryos per mouse and the percentage of different embryo stages in the t-RA treated mice administered at early pre-implantation embryo or late pre-implantation embryo stage were not significantly different from the controls. The mean number of embryos per 50 mg/kg mouse and the percentage of expanded blastocysts or early blastocysts/morulas did not differ from controls. In addition, the percentage of expanded blastocysts or early blastocysts/morulas was also not significantly different from the control group in 100 mg/kg late pre-implantation mice.

CONCLUSION

Mouse embryo development may not experience dose related adverse effects from non-physiological RA exposure during pre-implantation.

High-level expression of recombinant dengue viral NS-1 protein and its potential use as a diagnostic antigen

The prevalence of NS1 Ab response in patients with dengue viral infection and the potential of using recombinant NS1 protein as a diagnostic antigen for dengue viral infection were investigated. In this study, the full-length and C-terminal half of NS1 proteins (rNS1, rNS1-C) were highly expressed (10-30 mg/l) and further purified and refolded. The good antigenicity of the full-length rNS1 protein was confirmed by interaction with 19 dengue NS1-specific monoclonal antibodies (MAbs) in ELISA; however, the antigenicity of rNS1-C was relatively lower. The full-length rNS1 antigen also differentiated reliably between sera from dengue virus-infected patients and sera from normal controls. When rNS1 was used as an antigen to detect human anti-NS1 IgM and IgG Ab, the anti-NS1 Ab response was found in 15 of 17 patients (88%) with primary dengue infection and all 16 patients (100%) with secondary dengue infection. These results indicated that using the full-length rNS1 whose antigenicity is restored as ELISA antigen, a high anti-NS1 antibody prevalence could be detected in patients with either primary or secondary dengue infection. This finding suggested that the anti-NS1 antibody appeared not only in secondary and severe dengue virus infection and might not correlate the pathogenesis of dengue hemorrhagic fever. The study also verified that our purified rNS1 protein showed similar immunological properties as native dengue viral proteins. Genetic engineering production of recombinant NS1 antigen could provide a safe and valuable resource for dengue virus serodiagnosis.