Observation of the Exotic 0_{2}^{+} Cluster State in ^{8}He

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

[Research progress on the effect of chemical environmental pollutant exposure on mitochondrial DNA damage]

People are exposed to a variety of different harmful factors through their daily life, diet, and occupational environment, and exposure to these dangerous factors results in varying degrees of damage to the organism. The damage to mitochondria from exposure to chemical harmful factors in environment is of increasing concern. The integrity of the mitochondrial genome is critical for mitochondrial function and cellular homeostasis, and mitochondria are susceptible to damage and mitochondrial dysfunction when stimulated by various harmful chemical environmental factors. It has been shown that exposure to a variety of chemical pollutants can produce varying degrees of damage to mitochondria, and these pollutants may cause mitochondrial structural and functional disorders by inducing oxidative stress, including impaired electron respiratory chain transmission, alterations in mitochondrial membrane potential, mitochondrial DNA mutations/deletions, and mitochondrial DNA copy number variation. Mitochondrial damage can further lead to abnormal cell function, apoptosis, and death, which induce related diseases. Therefore, this paper provides a review of the role of chemical factor exposure in the environment, such as heavy metals, on mitochondrial damage.

[The role of long non-coding RNA in the pathogenesis of pulmonary fibrosis of silicosis]

Silicosis is a progressive pulmonary fibrosis disease caused by long-term inhalation of a large amount of free crystalline silica, which seriously threatens the health of relevant workers and causes a huge amount of disease burden. The pathogenesis of silicosis is complex and unclear, it has been reported that long non coding RNA (lncRNA) plays an important role in the pathogenesis of silicosis. In order to improve the understanding of the disease and provide directions for the prevention and treatment of silicosis, this article reviewed the mechanism of lncRNA in the pathogenesis and disease progression of silicosis.

Using two-step cluster analysis to classify inpatients with primary biliary cholangitis based on autoantibodies: A real-world retrospective study of 537 patients in China

Background

A variety of autoantibodies have been detected in primary biliary cholangitis (PBC), while the presence of autoantibody clusters and their clinical significance have not been fully understood. We aimed at defining autoantibody clusters and to better understand the clinical features and prognosis of PBC patients based on autoantibody clusters under real-world conditions.

Methods

We retrospectively analyzed 788 inpatients with PBC evaluated between October 2008 and July 2019, and included 537 patients. Nineteen autoantibodies which were measured routinely were investigated for cluster analysis. Two-step clustering, Kaplan-Meier survival, and Cox regression analyses were used.

Results

Five clusters were defined. A cluster of antinuclear antibodies (ANA) and anti-gp210 positive patients were identified with a high rate of cirrhosis at baseline and low survival rate; a cluster of ANA, anti-centromere antibodies (ACA) and/or anti-CENP-B female dominant patients with older disease onset, low level of platelet count at baseline, high rate of hepatic decompensation, and low survival rate was also characterized; and another cluster of anti-mitochondrial antibodies (AMA) and/or AMA-M2, anti-Ro52 and a high rate of anti-gp210 positive patients were identified with a high proportion of male patients and low survival rate. A subgroup of patients with anti-SSA and/or anti-SSB coexists with SjS was also identified; patients with only AMA and/or AMA-M2-positive with a benign clinical outcome and relatively high complication of non-alcoholic fatty liver disease (NAFLD) were also identified. Only anti-gp210 was considered as a significant predictor for poor outcomes especially in patients with cirrhosis.

Conclusion

Clustering methods allow the identification of distinct autoantibody profiles of PBC that form clinical subsets and can be useful for personalized approaches to diagnosis, clinical management, and the prediction of clinical outcomes. Anti-gp210 was the strongest predictive factor for poor outcomes especially in PBC patients with cirrhosis under real-world conditions.

Disease predisposition of human leukocyte antigen class II genes influences the gut microbiota composition in patients with primary biliary cholangitis

Background

The human leukocyte antigen (HLA) susceptibility gene is the main genetic risk factor for primary biliary cholangitis (PBC). The prognosis of patients with PBC is linked to gut microbiota dysbiosis. However, whether the HLA alleles are associated with the gut microbiota distribution and disease severity remains unknown.

Methods

A cohort of 964 Chinese patients with PBC was enrolled at Beijing YouAn Hospital, Beijing, China. High-resolution genotyping of the HLA class I and class II loci from 151 of these patients was performed using sequence-based PCR. Stool samples were collected from 43 of the 151 fully HLA-typed patients to analyze their microbiota compositions via 16S RNA gene sequencing.

Results

Of the 964 patients, the male:female ratio was 114:850, and 342 of these patients (35.5%) had already developed liver cirrhosis (LC) before enrollment. Patients with PBC showed a significantly higher frequency of HLA DRB1*08:03 than did the controls (21.2% vs. 9.0%, P=0.0001). HLA-DRB1*03:01, DRB1*07:01, DRB1*14:05, and DRB1*14:54 frequencies were also increased but did not reach significance after Bonferroni’s correction. Conversely, the DQB1*03:01 frequency was significantly lower in patients with PBC than in the controls (24.5% vs. 39.2%, P=0.0010). The patients’ gut microbiota were analyzed from four perspectives. The microbial community abundances were significantly lower in FHRAC-positive patients (patients with a combination of five HLA DRB1 high-risk alleles) than in FHRAC-negative patients (P<0.05). Of the top 10 microbial genera, Lachnospiraceae_incertae_sedis was higher in the FHRAC-positive patients than in the FHRAC-negative patients (P<0.05). linear discriminant analysis (LDA) effect-size (LEfSe) analysis showed different microbes at different levels in the FHRAC-negative patients but not in the FHRAC-positive patients. DQB1*03:01-positive patients contained mostly Lactobacillaceae at the family level. A comparison of the FHRAC-positive patients with and without liver cirrhosis showed that the abundances of Veillonella were significantly higher in patients with cirrhosis and FHRAC than in those without cirrhosis and are FHRAC-negative.

Conclusion

The HLA class II genes may influence the gut microbiota compositions in patients with PBC. Differential gut microbiota were expressed at different taxonomic levels. Some bacterial abundances may be increased in FHRAC-positive patients with PBC and cirrhosis.

Characterization of the Clinical Features in HBV-Related Acute-on-Chronic Liver Failure

OBJECTIVE

Acute-on-chronic liver failure (ACLF) is a type of liver failure commonly found in China, and currently the mechanism of the disease remains unknown. This study aimed to investigate the epidemiology, clinical features and prognostic factors in ACLF.

METHODS

This study retrospectively included 170 patients with ACLF admitted to Beijing Friendship Hospital in Beijing, China from November 2017 to May 2019. Patients were divided into 2 groups: the improved group and the deteriorated group, according to the severity of their disease. Patients' demographic data; clinical manifestations; complications; laboratory indicators including platelets (PLT), alanine aminotransferase (ALT), aspartate amino transferase (AST), total bilirubin (TBIL), prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin activity (PTA), international normalized ratio (INR), and alkaline phosphatase (ALP) were collected. The relationship between these factors and the patients' prognosis were analyzed by logistic multivariate regression analysis.

RESULTS

The highest morbidity rate was in the age group 40 to 49 years (29.41%). The age group with the second highest morbidity was between 50 and 59 years (25.29%), followed by >60 (21.18%), 30 to 39 (20.59%), 20 to 29 (2.94%) and <20 years (0.59%). A total of 53 patients (31.18%) had a family history of hepatitis B virus infection. The patients' main clinical manifestations were ascites (77.65%) and weakness (68.23%). The most common complications were hypoalbuminemia (80%), infection (67.65%) and electrolyte imbalance (44.12%). In addition, the PTA (P = .009), hepatorenal syndrome (P = .005) and hepatic encephalopathy (level IV) (P = .005) were independently related to the prognosis of ACLF. There is a significant relationship between complications and prognosis (χ2 = 8.502; P = .004).

CONCLUSION

This study showed that prothrombin activity, hepatorenal syndrome and hepatic encephalopathy were independently related to the prognosis of ACLF. This outcome provided more options for reducing patient mortality in clinic.

[Characteristics of clinical and laboratory indexes in patients with liver disease with positive anti-liver cytosol antibody]

Objective: To analyze the characteristics of clinical and laboratory indexes in patients with liver disease with positive anti-liver cytosol antibody type 1 (anti-LC1), in order to provide references for clinical and differential diagnosis. Methods: The clinical data of 23 832 inpatients and outpatients with positive anti-LC1 autoantibodies detected in routine autoantibody test from January 2010 to January 2020 were retrospectively analyzed, and their clinical and laboratory indexes were compared. Western blotting was used to detect anti-LC1, anti-soluble liver antigen antibody (anti-SLA), anti-glycoprotein 210 antibodies and anti-nucleosome 100 antibodies. Indirect immunofluorescence assay was used to detect anti-nuclear antibody (ANA), anti-mitochondrial antibody, anti-Smooth muscle antibody (ASMA), anti-liver and kidney microsomal antibody (anti-LKM) and other autoantibodies. Normally distributed measurement data between the two groups were compared by independent-sample t-test, and the multiple groups comparison were compared by one-way analysis of variance. Non-normally distributed measurement data were compared by non-parametric rank sum test. Results: 38 anti-LC1 positive patients were detected in 23832 autoantibody tests. The age of initial diagnosis ranged from 11.0 to 84.0 (50.6 ± 16.0) years. There were 8 males (21.1%) and 30 females (78.9%). A total of 31 cases (81.6%) were positive for anti-LC1 and ANA, and the dominant karyotype was speckled pattern, accounting for 54.8%. Five cases (13.2%) were positive for ASMA, and no simultaneous positive with anti-LKM or anti-SLA. Among the 38 anti-LC1 positive patients, 9 were diagnosed with autoimmune hepatitis (AIH), 6 with possible AIH, 6 with primary biliary cholangitis (PBC), 8 with hepatitis B, 2 with hepatitis C, 1 with alcoholic liver disease, 2 with non-alcoholic fatty liver disease, 1 with drug-induced liver injury, 1 with hepatolenticular degeneration, and 2 with tumor. Confirmed and probable AIH cases accounted for 39.5% (15/38) of anti-LC1 positive cases. Among anti-LC1 positive patients, 47.4% (18/38) had entered the stage of liver cirrhosis. AIH group globulin level was higher than HBV group (P = 0.006) and other disease groups (P = 0.001). AIH group IgG level was higher than PBC group (P = 0.027), HBV group (P = 0.009) and other disease groups (P = 0.004). the of the PBC group IgM level was higher than AIH group (P = 0.003), HBV group (P = 0.003) and other disease groups (P = 0.006). Conclusion: Anti-LC1 is not only detected in AIH, but also observed in patients with primary biliary cholangitis, hepatitis B and C, alcoholic and non-alcoholic liver disease, drug-induced liver injury, hereditary metabolic liver disease and tumor. In addition, it is mainly female gender dominance and nearly half of ANA-positive young, middle-aged and elderly patients develop liver cirrhosis. For the diagnosis of type 2 autoimmune hepatitis, whether anti-LC1 is a specific antibody needs further research, but if AIH is highly suspected, this antibody can be used as a substitute.

[Clinical application of supraclavicular fasciocutaneous island flap in the repair of tracheal defects]

Objective: To explore the clinical application of supraclavicular fasciocutaneous island flap (SIF) in the repair of tracheal defect. Methods: From May 2016 to March 2021, the clinical data of 10 patients (8 males,2 females,aged 27-73 years old) were retrospectively analyzed who underwent repair surgery with SIF for trachea defects after resection of cervical or thoracic tumors, including 2 cases of laryngotracheal adenoid cystic carcinoma, 2 cases of laryngeal carcinoma, 3 cases of esophageal carcinoma, 2 cases of thyroid carcinoma and one case of parathyroid carcinoma. All of the primary tumors were at T4. The outcomes of 10 cases with tracheal defect repaired by SIF were evaluated. Results: The areas of the SIF were (3-7) cm × (6-10) cm, the thicknesses of the flaps were 8-11 mm, and the lengths of the pedicles were 10-15 cm. The blood supply of the SIF came from the transverse carotid artery. The skin defects of the donor areas of the shoulders were directly closed. After 1-60 months of follow-up, all the flaps survived. The flaps, tracheas as well as shoulder wounds healed well. Conclusion: The SIF is suitable for the repair of tracheal defects. It has perfect thickness compatible with the trachea. The technique is simple and microsurgical technique is not needed, with a good application prospect.

[The impact of CD8 and CTLA-4 expression on histopathological character and survival in mesothelioma]

Objective: To investigate the survival and death risk factors of mesothelioma cases stratified by the expression levels of CD8 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) , providing new clue to evaluate disease progression and clinical outcome. Methods: This was a retrospective case report, which included 47 clinically and pathologically confirmed mesothelioma cases on November 2016. Their clinical and pathological information, asbestos exposure history and survival data were collected. Infiltrated lymphocyte, 5-methylcytosine (5-mC) , CTLA-4, CD8 and Ki-67 antigen were detected using hematoxylin-eosin staining and immunohistochemistry. Survival time and death risk factors of mesothelioma patients with different CD8 and CTLA-4 protein expression characteristics were analyzed. And analyze the influence of Ki-67 expression on the survival of patients with different CD8 and CTLA-4 protein and gene expression characteristics. Results: Among the 47 cases, 63.8% (30/47) had low/medium level of infiltrated lymphocyte. The immunohistochemistry scores of CTLA-4, CD8, 5-mC and Ki-67 were 92.97 (54.95, 120.65) , 72.41 (36.62, 89.82) , 11.09 (3.40, 52.89) and 5.88 (2.41, 11.48) , respectively. Patients with CD8(high) CTLA-4(high) had higher 5-mC level than those with CD8(high) CTLA-4(low) (P<0.01) . The median survival time of 27 cases was 0.83±0.29 year. The median survival times of those with CD8(high) CTLA-4(high) and CD8(high) CTLA-4(low) were 0.58±0.51 year and 0.83±0.30 year, respectively (P=0.521) . The immunohistochemistry score of Ki-67 ≥5.88 was an independent death risk factor for patients with CD8(high) CTLA-4(low) (HR=8.40, P=0.01) . Under different CD8 and CTLA-4 protein expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 expression were 0.57±0.11 years and 2.31±0.46 years, respectively (P<0.01) . Under different CD8 and CTLA-4 mRNA expression characteristics, in the patients with CD8(high) CTLA-4(low), the median survival times of those with high and low Ki-67 mRNA expression were 1.20±0.36 years and 3.38±0.43 years, respectively (P=0.018) . Conclusion: Mesothelioma case with high CD8 but low CTLA-4 content might coexist DNA hypomethylation. In the presence of high Ki-67 expression, their survival time appears to be shortened with increased death risk.

Clinical characteristics and HLA genotypes in Chinese patients with anti-SLA/LP-positive autoimmune hepatitis

Background

Anti-soluble liver antigen/liver pancreas (anti-SLA/LP) is a highly specific serological marker for the diagnosis of autoimmune hepatitis (AIH). The aim of the present study was to define the clinical characteristics and human leucocyte antigen (HLA) genotypes of Chinese patients with anti-SLA/LP positive AIH.

Methods

Ninety-one AIH patients who were anti-SLA/LP positive were enrolled in this case control study. Clinical information was obtained through reviewing patients’ clinical notes. High-resolution genotyping of HLA-A, B, C, DRB1, and DQB1 alleles was performed by sequence-based typing polymerase chain reaction on 62 of the 91 patients. Data from 500 healthy patients were used as baseline controls.

Results

Anti-SLA/LP-positive AIH patients were characterized as follows: adults (age 20–80 years), female (88%), and frequent anti-nuclear antibody positivity (91%). Genetically, compared with the controls, HLA-B*35:01 and C*08:01 were significantly more frequent in patients. The frequencies of HLA-B*08:01, B*40:02, DRB1*04:01, DRB1*04:05, DRB1*14:01, and DRB1*16:02 increased, and the frequency in DRB1*15:01 decreased in patients, but did not reach significance after Bonferroni’s correction. Patients with other autoimmune diseases had a higher DRB1*04:05 and DQB1*04:01 allele carrier frequency than those without. DRB1*04:05 and DQB1*04:01 alleles were found at increased frequency in patients with decompensated liver disease than those with compensated liver disease.

Conclusions

Chinese anti-SLA/LP-positive AIH patients have some distinct clinical characteristics than other populations reported in the literature. The presence of certain specific HLA alleles could potentially increase the risk of developing anti-SLA/LP-positive AIH or other autoimmune disease and decompensated liver disease in the Chinese population.

[Emergency laboratory construction and reflection in infectious hospital under the epidemic situation]

Emerging infectious diseases are a common type of public health emergencies, which occur frequently around the world in recent years, seriously threatening the safety of human life and property. In the process of dealing with epidemic situation, medical laboratories have played an important role in disease diagnosis, treatment, efficacy evaluation and prognosis judgment and so on. Beijing Youan Hospital, as the designated hospital of the coronavirus disease 2019 (COVID-19), has set up an emergency laboratory in the capital for the prevention and control of the COVID-19 by carrying out routine tests and virus nucleic acid tests, it provides timely and effective evidence for clinical diagnosis and treatment. To provide ideas and references for the building of the Emergency Laboratory in infectious hospitals. This article discuss how to set up an independent emergency laboratory efficiently, strengthen the cooperation with the Center for Disease Control and Prevention, make the best use of all resources, and share the enlightenment gained in the process of construction.

The prevalence and immunological features of anti-glomerular basement membrane antibody in patients with HIV

Background

Anti-glomerular basement membrane disease (GBM) is an autoimmune disease caused by the deposition of circulating anti-GBM antibodies. Non-collagen region of α3 chain of type IV collagen (α3(IV)NC1) is one of the main target antigens, in which E_A and E_B are the most classical antigen epitopes. It has been reported that anti-GBM antibodies can be detected in HIV patients; however, its immunological characteristics are still unclear.

Objectives

In this study, the positive rate of the anti-GBM antibodies in HIV and the immunological characteristics of the target antigens were clarified.

Methods

A total of 93 HIV patients diagnosed in Beijing Youan Hospital from November 2017 to January 2018 were included. Enzyme-linked immunosorbent assay was used to measure the serum IgG autoantibodies specifically against GBM in these patients, as well as their subtypes and antigen spectra.

Results

It was found that five out of the 93 patients with HIV had low to moderate levels of anti-GBM antibodies. However, these patients presented with no clinical manifestation of any kidney injury or pulmonary hemorrhages. Compared with HIV patients with negative antibodies, there were no significant differences in gender, age, CD4⁺T cell count and HIV viral load. All sera of five patients recognized non-collagenous domain1 (NC1) of alpha 3 chain of type IV collagen [(α3(IV)NC1] as classic anti-GBM patients, followed by α5(IV)NC1. The antibodies against α3(IV)NC1 were IgG3 predominant, while these antibodies did not react with either of the classic epitopes on α3 (E_A and E_B).

Conclusion

These data suggest a distinct immunological profile of anti-GBM antibodies in patients with HIV, and might explain the non-pathogenic features of HIV associated anti-GBM antibodies.

A multiple-center clinical evaluation of a new real-time reverse transcriptase PCR diagnostic kit for SARS-CoV-2

Aim: The outbreak of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has had serious repercussions worldwide. This study was aimed to evaluate the accuracy of a new kit for detection of SARS-CoV-2 compared with similar detection kit. Materials & methods: A total of 500 subjects were included and tested with both the new test and control kits. Clinical diagnosis results were taken as the reference standard. Results: Compared with clinical diagnosis, the sensitivity of the test kit was 82.64%, specificity was 98.45% and total coincidence rate was 90.80%. The total coincidence rate, sensitivity and specificity between control kit and clinical diagnosis were 89.20%, 78.10% and 99.61%, respectively. Conclusions: The new kit was comparable to the similar detection kit for detection of SARS-CoV-2 in sensitivity, specificity and total coincidence rate.

[Analysis of influencing factors of textile workers' occupational stress]

Objective: To explore the occupational stress status and influencing factors of workers in a textile factory in Zhejiang Provice. Methods: In October 2018, 505 workers from a textile factory in Zhejiang Province were selected as research objects by convenient sampling method. A total of 505 questionnaires were distributed, 495 of which were effective and the effective recovery rate was 98.0%. Job Content Questionnaire (JCQ) and Effort Reward Imbalance Questionnaire (REI) were used to investigate textile workers' occupational stress and analyze its influencing factors. The differences of the composition ratio of different groups were tested by χ(2) test. The influencing factors such as age, gender and occupation on occupational stress were analyzed by multivariate logistic regression. Results: ERI analysis results showed that the high and low occupational stress accounted for 30.1% and 69.9%, respectively. The differences of occupational stress among workers of different job types and working ages were statistically significant (P<0.05) . The detection rates of high occupational stress of paper workers and spinners were 47.8% (11/23) and 44.8% (30/67) , respectively, higher than other jobs. The detection rate of high occupational stress for workers with more than 5 years of service was 46.4% (13/28) . The results of JCQ analysis showed that there was no statistical significance in the differences of daily working hours and length of service between different gender, education levels, types of work patterns, and occupational stress (P>0.05) . Job types had significant effects on the occupational stress defined by ERI (P<0.05) , the risk of occupational stress was 2.151 times than that of the coiler. Conclusion: There are significant differences in occupational stress risk among workers of different types of work in textile industry, so different measures should be taken to prevent and control occupational stress in different jobs.

Positive-Parity Linear-Chain Molecular Band in ^{16}C

An inelastic excitation and cluster-decay experiment ^{2}H(^{16}C,^{4}He+^{12}Be or ^{6}He+^{10}Be)^{2}H was carried out to investigate the linear-chain clustering structure in neutron-rich ^{16}C. For the first time, decay paths from the ^{16}C resonances to various states of the final nuclei were determined, thanks to the well-resolved Q-value spectra obtained from the threefold coincident measurement. The close-threshold resonance at 16.5 MeV is assigned as the J^{π}=0^{+} band head of the predicted positive-parity linear-chain molecular band with (3/2_{π}^{-})^{2}(1/2_{σ}^{-})^{2} configuration, according to the associated angular correlation and decay analysis. Other members of this band were found at 17.3, 19.4, and 21.6 MeV based on their selective decay properties, being consistent with the theoretical predictions. Another intriguing high-lying state was observed at 27.2 MeV which decays almost exclusively to ^{6}He+^{10}Be(∼6  MeV) final channel, corresponding well to another predicted linear-chain structure with the pure σ-bond configuration.

Coexistence of low levels of HBsAg and high levels of anti-HBs may increase risk of hepatocellular carcinoma in chronic hepatitis B patients with high HBV load

OBJECTIVE

The clinical significance of coexistence of HBsAg/anti-HBs in chronic hepatitis B (CHB) patients remains controversial. This study was aimed to assess the association of this serological pattern with hepatocellular carcinoma (HCC) in patients with CHB.

METHODS

In this cross-section study, 206 CHB patients with coexistence of HBsAg/anti-HBs and 206 CHB patients with HBsAg alone were included to evaluate the risk of HCC development by logistic regression analysis. In addition, a retrospective cohort of 260 patients with CHB was recruited to estimate the cumulative incidence of HCC by Kaplan-Meier analysis.

RESULTS

The serological pattern of coexistence of HBsAg/anti-HBs, with high levels of ("High") HBsAg/low levels of ("Low") anti-HBs, were considered as independent risk factors for HCC. In particular, patients with "High" HBsAg/"High" anti-HBs [odds ratio (OR), 4.295; 95% confidence interval (CI), 1.104-16.699; p = 0.035] and "Low" HBsAg/ "High" anti-HBs (OR, 3.207; 95%CI, 1.299-7.919; p = 0.012) exhibited significantly higher risk for HCC development. However, only "Low" HBsAg /"High" anti-HBs might increase risk of HCC in CHB patients with high HBV load (logrank p < 0.001) in our cohort study.

CONCLUSION

The coexistence of "Low" HBsAg /"High" anti-HBs might increase the risk of HCC development in CHB patients with high HBV load, which reflected that the long-term interaction between immune response and virus might lead to the development of HCC. The identification of the patients with poor prognosis will help clinicians to refine the therapeutic decisions and individualize follow-up strategies.

Retraction Note: Construction of Gpm6a/ReelinGFPCreERT2 by BAC recombination using a specific gene in hepatic mesothelial or stellate cells

We have decided to retract the above article for further consideration due to some misunderstandings in communication.

Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying β-Emitting Isomers in ^{123,125}Ag

The β-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} β-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals.

[An analysis of the serological characteristics of anti-mitochondrial M2 subtype in patients with drug-induced liver injury and primary biliary cholangitis]

Objective: To analyze the serological characteristics of anti-mitochondrial antibody M2 subtype (AMA-M2) in patients with drug-induced liver injury (DILI) and primary biliary cholangitis (PBC), in order to provide reference for clinical differential diagnosis. Methods: Laboratory data of 2802 DILI cases who visited the hospital between January 2011 and December 2017 were retrospectively collected. AMA-M2 positive patients were analyzed with respect to laboratorical findings, and serum data of 120 patients with primary biliary cholangitis (PBC) at the same period was taken as a control. A chi-square test was used for group comparisons. One-way ANOVA and rank sum tests was used for ALT, AST, ALP, GGT and three groups of immunoglobulin M. Results: Among 2802 DILI patients, AMA-M2 positive rate was 5.1% (144/2 802), 77.1% (111/144) was DILI alone, 22.2% (32/144) was DILI with PBC, and 0.7% (1/144) was DILI with Sjogren's syndrome. An AMA-M2 level in DILI alone group was mostly mild and moderate than the PBC group and the DILI combined with the PBC group. There was significant difference between the two groups (P < 0.05).There was no significant difference in AMA-M2 levels between DILI group combined with PBC group and PBC group (P > 0.05). ALT and AST levels of DILI alone group and DILI combined with PBC were (585.92 ± 653.04) U/L, (501.45 ± 512.67) U/L and (373.47 ± 502.60) U/L, (335.97 ± 513.96) U/L, respectively, which were significantly higher than PBC group [(106.33 + 134.08) U/L, (112.59 + 152.20) U/L]. There were statistically significant differences between the two groups (P < 0.05).The ALP level of DILI alone group was (152.58 + 81.46) U/L, which was lower than PBC group (237.86 + 215.09). The difference was statistically significant (P < 0.05). The level of immunoglobulin M in the DILI alone group was (1.76 ± 1.16) g/L, which was lower than PBC group (4.74 ± 5.74) g/L and the DILI combined with the PBC group (3.31 ± 1.68) g/L. There was significant difference between the two groups. During follow-up, 2.7% of patients with DILI had cirrhosis, 42.3% had lower AMA-M2 titer, 14.4% had lower AMA-M2 titer, 13.5% had higher AMA-M2 titer and five cases developed PBC. Conclusion: AMA-M2 is not only positive in patients with PBC, but also low-to-medium or even high-level AMA-M2 may be detected in DILI patients. For AMA-M2-positive DILI patients, it is necessary to identify whether they are associated with PBC. Secondly, the levels of ALT, AST and ALP should be analyzed, and the patients should be on regular follow up for early and timely detection of drug-induced PBC.

[A review on the RET proto-oncogene mutation in medullary thyroid carcinoma]

Medullary thyroid carcinoma（MTC） is a special type of neuroendocrine tumor originated from C-cells of the thyroid gland, MTC can be divided into sporadic(70%-80%)and hereditary(20%-30%), about 98% of the hereditary MTC patients have RET proto-oncogene germline mutation in exon 10, 11, 13, 14, 15, 16. The mutation of RET proto oncogene is closely related to the pathogenesis of MTC, and different mutation of RET proto oncogene exon may lead to different MTC phenotypes.More than 100 kinds of mutations in the RET gene were reported. This paper reviews the research progress of RET proto-oncogene mutation in MTC.

[Analyzing the mental health status and its impact factors among female nurses in China]

Objective: To analyze the mental health status and its impact factors among nurses, finding ways to improve the mental health of nurses. Methods: A total of 13 425 female healthcare workers aged from 18 to 65 were selected as study objects. The survey was conducted with unified design questionnaire. The survey included the basic situation of the individuals and SCL-90 questionnaire. Comparing the female doctors, the mental health status and its impact factors of nurses were analyzed. Results: The income, age, education and occupation, which include shift work, heavy work load and overtime work are different between nurses and doctors. The main mental health problems of nurses were obsessive-compulsive symptoms, depressive symptoms and somatization. The results of univariate analysis indicated that shift work, overtime work, and heavy work load affected the positive rate of each factor. The results of multivariate analysis showed that occupation, shift work, overtime work, and heavy work load have significant adverse effects on the positive rate of the total score in female healthcare workers (P<0.01) . The positive rate of each dimension of SCL-90 in nurses is significantly higher than that of doctors. Conclusion: The mental health problems of nurses are significantly higher than doctors. The main reasons are low occupational level and adverse workstyles which include shift work, heavy workload and so on. Health administration and hospital management departments should pay much more attention to the mental health of nurses, improving their mental health through a variety of ways.

Potential human exposures to neonicotinoid insecticides: A review

Due to their systemic character and high efficacy to insect controls, neonicotinoid insecticides (neonics) have been widely used in global agriculture since its introduction in early 1990. Recent studies have indicated that neonics may be ubiquitous, have longer biological half-lives in the environment once applied, and therefore implicitly suggested the increasing probability for human exposure to neonics. Despite of neonics' persistent characters and widespread uses, scientific literature in regard of pathways in which human exposure could occur is relatively meager. In this review, we summarized results from peer-reviewed articles published prior to 2017 that address potential human exposures through ingestion and inhalation, as well as results from human biomonitoring studies. In addition, we proposed the use of relative potency factor approach in order to facilitate the assessment of concurrent exposure to a mixture of neonics with similar chemical structures and toxicological endpoints. We believe that the scientific information that we presented in this review will aid to future assessment of total neonic exposure and subsequently human health risk characterization.

[Planned neck dissection in the treatment of locally advanced head and neck squamous cell carcinoma]

Objective: To investigate the value of planned neck dissection combined with induction chemotherapy and concurrent chemoradiotherapy in regional control and the outcome of locally advanced head and neck squamous cell carcinoma. Methods: A prospective randomized controlled study totally enrolled sixty-four patients of head and neck squamous cell carcinomas(include oropharynx, hypopharynx, and larynx) in stages Ⅳa-Ⅳb with lymph node metastase was were N2-N3. All patients firstly received 2-3 cycles of induction chemotherapy(ICT), then divided into two groups randomly, according to the efficacy of ICT. Group A(the study group) received planned neck dissection(PND) and concurrent chemoradiotherapy(CCRT). Group B(the control group) received concurrent chemoradiotherapy(CCRT). The differences in clinicopathologic features, local recurrence(LR), regional recurrence(RR), disease-free survival(DFS), and overall survival(OS) between the two groups were estimated. SPSS 19.0 software was used to analyze the data. Results: Group A enrolled twenty-one patients, and group B enrolled forty-three patients.The follow-up of all patients were 4-55 months, median follow-up time was 22 months. In study group, two-year OS and DFS were 80.9% and 68.3%, respectively. In control group, two-year OS and DFS were 90.7% and 67.1%, respectively. There was no significant difference in gender(P=0.215), age(P=0.828), primary tumor site(P=0.927), LR(P=0.126), DFS(P=0.710), and OS(P=0.402) between the two groups, while the RR(χ(2)=5.640, P<0.05) and distant metastasis(χ(2)=10.363, P<0.01) showed significant differences between the two groups. Conclusion: The ICT+ PND+ CCRT treatment model has benefit on regional control of locally advanced head and neck squamous cell carcinoma.

[Diagnostic value of albumin-bilirubin grade combined with serum ammonia in cirrhosis with hepatic encephalopathy]

Objective: To explore the value of albumin-bilirubin (ALBI) grade combined with serum ammonia in the diagnosis of cirrhosis with hepatic encephalopathy (HE). Methods: The serum level of total bilirubin(TBIL), albumin( ALB )and blood ammonia were detected in 139 patients including 73 cirrhosis patients without HE and 66 cirrhosis patients with HE from January 2015 to January 2017 in Beijing You'an Hospital, and the relationship between ALBI and blood ammonia value and Child grade and hepatic encephalopathy was analyzed. Results: The level of ALBI and blood ammonia were more and more higher with the increase of Child grade, the level of ALBI in Child A, B and C were -2.3±0.6, -1.7±0.5, -0.9±0.4, and there was a statistically significant(F=125.100, P<0.001). The blood ammonia concentration in Child A, B and C were(42.6±16.0), (56.1±31.2), (69.8±34.7) μmol/L, and there was a statistically significant(F=7.400, P<0.001). The level of ALBI was higher with the increase of model for end-stage liver disease (MELD) grade, and there was a positive correlation(r=0.547, P<0.001). The ALBI value in the HE group was higher than the cirrhosis patients without HE((-1.1±0.5)vs(-1.6±0.7)), and the difference was statistically significant (t=5.244, P<0.001). Level of blood ammonia in the HE group was(83.6±39.5)μmol/L, which was higher than the level of cirrhosis patients without HE(42.9±17.0)μmol/L, and the difference was statistically significant (t=8.130, P<0.001) . When ALBI and blood ammonia were combined, the ROC curve area was 0.911, the sensitivity was 93.9%, the specificity was 93.2%. Conclusion: There is a significant diagnosis value and high clinical application when ALBI is combined with blood ammonia to diagnose HE .

[Changes of microRNAs profiling in mesothelial cells exposed to multi-walled carbon nanotubes]

Objective: To explore the cytotoxicities of MWCNT to the mesothelial cells and screen the changes of microRNA profile after exposure to MWCNT. Methods: A LDH method was used to test the cytotoxicities of MWCNT to MeT-5A cell lines. And then the differentially expressed miRNAs between mesothelioma cells and normal mesothelial cells were selected from previous work of research group. Among the significant expression changed miRNAs, 5 were verified by RT-qPCR in mesothelioma cells. The same five ones were further tested in MeT-5A cells exposed to 10 μg/cm² MWCNT for 8, 24, 48, 72 h by RT-qPCR. Target genes of 5 miRNAs were predicted using Targetscan and miRanda softwares. David6.7 was used to perform GO enrichment and KEGG pathway analysis of target genes. All the data were analyzed by one-way ANOVA and Dunnett-T test in SPSS17.0. Results: After 24 h exposure to MWCNT, cell proliferation was significantly suppressed at more than 20 μg/cm² concentration. Among the differentially expressed miRNAs, 5 were chosen to further vestified, namely hsa-miR-155 (up-regulated) , hsa-miR-30 d-5p, hsa-miR-34c-5p, hsa-miR-28-5p and hsa-miR-324-5p (down-regulated) , which were consistent with the miRNA array results. The 5 miRNAs also had the same expression changes in MeT-5A cells after exposure to 10 μg/cm² MWCNT for different time periods. The potential target genes of the 5 miRNAs may be AKAP13, CCND3, Twist and E-Cadherin, which mainly involved in TGF-β signal pathway, small cell lung cancer, etc. Conclusion: MWCNT could induce to MeT-5A cells, and also cause miRNA expression changes. The differential changed miRNAs may involve in cancer related signal pathways.

Construction of Gpm6a/ReelinGFPCreERT2 by BAC recombination using a specific gene in hepatic mesothelial or stellate cells

AIM

To prepare a Gpm6a/Reelin^GFPCreERT2 construct with a rapid and reliable strategy using a bacterial artificial chromosome (BAC).

METHODS

Gpm6a and Reelin BACs were purified and transformed into SW102 E. coli by electroporation. The GFPCreERT2 fragment was prepared from a shuttle vector and transformed into SW102 E. coli carrying a BAC. Homologous recombination was induced in SW102 E. coli. Recombinant clones were screened and confirmed by PCR and restriction enzyme digestion. Recombinant clones were transformed into SW102 E. coli to remove the kanamycin unit.

RESULTS

A complete BAC was successfully transformed into SW102 E. coli by electroporation because BAC purified from SW102 E. coli showed the same pattern as the original BAC with BamHI digestion. The GFPCreERT2 fragment was deemed to have been prepared successfully because we obtained the same size fragment as expected. Homologous recombination was induced, and GFPCreERT2 was deemed to have been inserted into the correct site of the BAC because we found the band change was the same as the expected pattern after restriction enzyme digestion. The kanamycin unit was deemed to have been removed successfully because we obtained different sizes of bands that were consistent with the results expected by PCR with different primers.

CONCLUSION

The construct of Gpm6a^GFPCreERT2 or Reelin^GFPCreERT2 was prepared successfully, which will establish a foundation for tracing the hepatic stellate cell lineage and studying its function.

Correlation between hepatitis B virus DNA levels and diagnostic tests for HBsAg, HBeAg, and PreS1-Ag in chronic hepatitis B

The aim of this study was to investigate the diagnostic value of the serum markers HBsAg and HBeAg and PreS1 protein (PreS1-Ag) in quantifying the levels of hepatitis B virus (HBV) DNA in patients with chronic hepatitis B (CHB). One thousand CHB patients were recruited from Beijing You'an Hospital between June and December 2012. Serum HBsAg and HBeAg levels were detected by electrochemiluminescence immunoassay. Enzyme-linked immunosorbent assay and fluorescence quantitative PCR were used to determine the level of PreS1-Ag and HBV DNA, respectively. We observed a low correlation between HBsAg and HBV DNA (r = 0.172, P < 0.001) expression; however, the correlation coefficient increased gradually with the increase in HBV DNA levels, and was more significant when HBV DNA log10 > 7 (r = 0.597, P < 0.001). Additionally, HBsAg and HBV DNA showed a significant positive correlation in the HBeAg+ group (r = 0.321, P < 0.001), whereas no correlation was observed in the HBeAg- group (r = -0.016, P = 0.825). HBV DNA expression was correlated with HBeAg (χ2 = 83.07, P < 0.001) and PreS1-Ag (χ2 = 36.01, P < 0.001). HBV DNA-positive rate was higher in HBeAg/PreS1-Ag++ patients (72.26%) than that in the single-positive groups (P < 0.001). Therefore, serum HBsAg is not a good marker for the prediction of HBV replication, and co-detection of HBeAg and PreS1-Ag, which can better predict HBV DNA replication, can be used as a reliable method for the clinical diagnosis and treatment of CHB.

Expression of regulatory T cells and natural killer cells in peripheral blood of patients in different stages of chronic hepatitis B virus infection

AIM: To investigate the expression of regulatory T cells (Tregs) and natural killer (NK) cells in the peripheral blood of patients with chronic hepatitis B virus (HBV) infection.

METHODS: A total of 96 chronic HBV infected patients were enrolled, including 42 chronic hepatitis B patients, 30 cirrhosis patients, and 24 hepatitis B carriers. There were 21 healthy persons as controls. Peripheral blood was collected from subjects to detect the expression of Tregs and NK cells, by means of flow cytometry.

RESULTS: The expression of CD4⁺CD25⁺Foxp3⁺ Tregs in peripheral blood was the highest in the hepatitis B cirrhosis group, followed by chronic hepatitis B patients, HBV carriers and healthy controls. In contrast, the percentage of NK cells in the cirrhosis group was the lowest, followed by chronic hepatitis B patients and HBV carriers, but all of them had lower percentage of NK cells than healthy controls. Further analysis showed that the expression of Tregs was negatively correlated with NK cells (r = -0.3280, P < 0.05).

CONCLUSION: The expression of Tregs and NK cells in the peripheral blood of chronic HBV infected patients is different with the disease course, and they are negatively correlated.

Autophagy in anti-apoptotic effect of augmenter of liver regeneration in HepG2 cells

AIM

To investigate the role of autophagy in the anti-apoptotic effect of augmenter of liver regeneration (ALR).

METHODS

Autophagy was induced through serum deprivation. An ALR-expressing plasmid was transfected into HepG2 cells, and autophagic flux was determined using fluorescence microscopy, electron microscopy, Western blot and quantitative polymerase chain reaction (qPCR) assays. After ALR-expressing plasmid transfection, an autophagy inhibitor [3-methyladenine (3-MA)] was added to HepG2 cells, and apoptosis was observed using fluorescence microscopy and flow cytometry.

RESULTS

Autophagy was activated in HepG2 cells, peaking at 24 h after serum deprivation. Microtubule-associated protein light chain three-II levels were higher in HepG2 cells treated with ALR than in control cells, fluorescence microscopy, electron microscopy and qPCR studies showed the similar trend, and p62 levels showed the opposite trend, which indicated that ALR may play an important role in increasing autophagy flux. The numbers of apoptotic cells were substantially higher in HepG2 cells treated with both ALR and 3-MA than in cells treated with ALR alone. Therefore, the protective effect of ALR was significantly attenuated or abolished when autophagy was inhibited, indicating that the anti-apoptotic effect of ALR may be related to autophagy.

CONCLUSION

ALR protects cells from apoptosis partly through increased autophagy in HepG2 cells and may be valuable as a new therapeutic treatment for liver disease.

Regulatory T cells promote liver fibrosis in mice

AIM: To investigate the role of regulatory T cells (Tregs) in the development of liver fibrosis in mice.

METHODS: Experimental mice were divided into three groups: a liver fibrosis group, a liver fibrosis + anti-CD25 group and a control group. Liver fibrosis was induced by intraperitoneal injection of 30% carbon tetrachloride (CCl4). Four weeks later, mice in the liver fibrosis + anti-CD25 group were intraperitoneally injected with the purified CD25 monoclonal antibody (PC61 culture supernatant) to deplete Tregs. The mice injected with the same volume of saline were used as controls. Flow cytometry was used to detect the level of liver CD4⁺CD25⁺ T cells, immunofluorescence was used to stain the activated hepatic stellate cells (α-SMA), and real-time PCR was used to detect the expression of Foxp3 and type-Ⅰ and -Ⅲ collagen in the liver.

RESULTS: Flow cytometry analysis showed that the number of Tregs was significantly higher in liver fibrosis mice; after injection of CD25 antibody, CD4⁺CD25⁺ T cells in the liver were decreased by 50%. Real-time PCR showed that Foxp3 mRNA expression was significantly decreased compared to the fibrosis group. Immunofluorescence results showed that α-SMA was significantly reduced after Tregs depletion, compared to liver fibrosis mice. The mRNA levels of type-Ⅰand type-Ⅲ collagen were also decreased after Tregs depletion.

CONCLUSION: Tregs can promote liver fibrosis in mice.

Observation of enhanced monopole strength and clustering in (12)Be

In a recent breakup-reaction experiment using a Be12 beam at 29  MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0  fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.

[Effect of puerarin on liver injury in KKAy mice with type 2 diabetes mellitus]

OBJECTIVE

To study the possible pathogenic mechanism of liver injury in type 2 diabetes mellitus (T2DM) and the intervening effect of puerarin on it.

METHODS

Mice with T2DM (KKAy) were randomly divided into two groups, the model group and the puerarin group. And the C57BL/J mice of the same age were set up as normal controls. They were sacrificed at 28 weeks old for observing serum fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT), aspartate aminotransferase (AST) by automatic biochemistry; liver cell apoptosis by flow cytometry; pathomorphology by electron microscope; and mRNA expressions of bcl-2 and bax genes by RT-PCR; as well as the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), Na(+)-K(+)-ATPase; and content of malondialdehyde (MDA) in liver tissue by spectrophotometer.

RESULTS

In KKAy mice, blood levels of FBG, TG, TC, ALT, AST and liver cell apoptosis rate were higher; the bax mRNA expression was higher and bcl-2 mRNA was lower markedly; the activities of SOD, GSH-Px, Na(+)-K(+)-ATPase in liver tissue were lower, and MDA content was higher than those in the normal control significantly (all P <0.01). Besides, mitochondria swelling and damage were found in liver tissue. While in the puerarin group after treatment, all the above-mentioned changes were alleviated to some extent.

CONCLUSIONS

Obvious liver injury emerges in KKAy mice. Puerarin shows a protective effect on the T2DM caused oxidative damage by way of up-regulating bcl-2 to inhibit oxidative stress, and improving the energy metabolic dysfunction in liver of mice.

Crystalline electric field as a probe for long-range antiferromagnetic order and superconducting state of CeFeAsO(1-x)F(x)

We use inelastic neutron scattering to study the crystalline electric field (CEF) excitations of Ce3+ in CeFeAsO(1-x)F(x) (x=0, 0.16). For nonsuperconducting CeFeAsO, the Ce CEF levels have three magnetic doublets in the paramagnetic state, but these doublets split into six singlets when the Fe ions order antiferromagnetically. For superconducting CeFeAsO0.84F0.16 T(c)=41 K), where the static antiferromagnetic order is suppressed, the Ce CEF levels have three magnetic doublets at [formula: see text], 18.7, 58.4 meV at all temperatures. Careful measurements of the intrinsic linewidth Gamma and the peak position of the 18.7 meV mode reveal a clear anomaly at T(c), consistent with a strong enhancement of local magnetic susceptibility chi'' [formula: see text] below T(c). These results suggest that CEF excitations in the rare-earth oxypnictides can be used as a probe of spin dynamics in the nearby FeAs planes.

[Effect of Xinnao Shutong capsule on apoptosis after cerebral ischemia and reperfusion in rats]

OBJECTIVE

To study apoptosis-regulating cytokines and apoptosis on focal cerebral ischemia and reperfusion in rats treated with Xinnao Shutong capsule.

METHOD

Rat models of focal cerebral ischemia and reperfusion were established by thread ligation in middle cerebral artery occlusions (MCAO). After 24 hours, the brains were removed to detect changes of protein expression of Bax, Bcl-2, Fas, Fas-L and caspase-3 by immuno-hisochemistry, and apoptosis of cortical neurons by TUNEL RESULT: Compared to control, brain cortex have decreasing the protein expression of Bcl-2 and the ratio of Bcl-2/Bax, increasing the protein expression of Bax, Fas, Fas-L and caspase-3 of ischemia and reperfusion models group (P < 0.01). Xinnao Shutong capsule group could increase the protein expression of Bcl-2 and the ratio of Bcl-2/Bax, and obviously decrease the protein expression of Bax, Fas, Fas-L and caspase-3, then reduce the number of apoptotic cells of cortex (P < 0.01).

CONCLUSION

Xinnao Shutong capsule protect injured rat brain tissue, may be related to decrease neuronal apoptosis and adjusted protein expression of apoptosis-regulating cytokines.

Voltammetric behavior of mammalian tumor cells and bioanalytical applications in cell metabolism

The voltammetric behavior of human mammalian cells was studied by choosing human leukemia cells (HL60) and human erythroleukemia cells (HEL). The voltammetric response of the cells was found having relation with cell metabolic viability in culture course. For example, the fluctuations of peak currents of HL60 were parallel with the nutrients replenished or not, which can reflect cell health state; the voltammetric response of HL60 regulated by the anti-metabolic drug 5F-Uriacil (5F-U) in culture course behaved in a much decreased manner, by which a voltammetric method for evaluating cytotoxicity is proposed. In this paper, the relation between HEL cell metabolism and the activation of receptor Mpl by its ligand TPO was also studied. Moreover, the mechanism of cell voltammetric behavior was discussed.

Production and characterization of a monoclonal antibody against sterigmatocystin

A monoclonal antibody, McAb-ST, specific for sterigmatocystin (ST) was produced in vitro and in vivo by a hybridoma anti-ST1. Anti-ST1 was prepared by fusion of SP2/0 murine myeloma cells with spleen cells isolated from BALB/c mouse that had been immunized with a complete antigen BSA-ST (ST conjugated to bovine serum albumin). Analysis revealed that McAb-ST was of the IgG1 type, the molecular weight of McAb-ST was 168,000 daltons (53,000 for each heavy chain, 31,000 for each light chain), and the apparent affinity constant of McAb-ST with H-ST (Hemocyanin and ST conjugate) was 1.29 x 10(9) mol/L. The relative cross reactivities of McAb-ST with ST analogs were less than 2% when determined by a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA). The minimal 0.5 pg of ST in 50 microliters of solution could be detected with CI-ELISA using McAb-ST, with a linear range of 0.1-10 ng/mL.

Production and characterization of sterigmatocystin

Fourteen strains of Aspergillus versicolor and 2 strains of A. nidulans were screened for sterigmatocystin (ST) production on a semi-synthetic solid substrate by high performance liquid chromatography (HPLC) analysis. Two strains of A. versicolor producing ST at 550.5 mg.kg-1 substrate and 1160.8 mg.kg-1 substrate were selected to inoculate 4 kg solid ST-producing media. After 30 days stationary incubation at 28 degrees C in the dark, 2271.6 mg of pale-yellow needle-shaped crystals were isolated and purified from the culture with a procedure applying column chromatography and recrystallization method. The crystal was proved to be sterigmatocystin by spectroanalysis and some physico-chemical analysis. The purity of the final material obtained were more than 99.9% as shown by HPLC and TLC detection. With this procedure, ST was obtained at about one tenth of its commercial cost.