PHDtools: A platform for pathogen detection and multi-dimensional genetic signatures decoding to realize pathogen genomics data analyses online

OBJECTIVES

Facing the emerging diseases, rapid identification of the pathogen and multi-dimensional characterization of the genomic features at both isolate-level and population-level through high-throughput sequencing data can provide invaluable information to guide the development of antiviral agents and strategies. However, a user-friendly program is in urgent need for clinical laboratories without bioinformatics background to decode the complex big genomics data.

METHODS

In this study, we developed an interactive online platform named PHDtools with a total of 15 functions to analyze metagenomics data to identify the potential pathogen and decode multi-dimensional genetic signatures including intra-/inter-host variations and lineage-level variations. The platform was applied to analyze the meta-genomic data of the samples collected from the 172 imported COVID-19 cases.

RESULTS

According to the analytical results of mNGS, 27 patients were found to have the co-infections of SARS-CoV-2 with either influenza virus (n = 9) or human picobirnavirus (n = 19). Enough coverages of all the assembled SARS-CoV-2 genomes provided the sub-lineages of Omicron variant, and the number of mutations in the non-structural genes and M gene was increased, as well as the intra-host variations occurred in E and M gene were under positive selection (Ka/Ks > 1). These findings of increased or changed mutations in the SARS-CoV-2 genome characterized the current adaptive evolution patterns of Omicron sub-lineages, and revealed the evolution speed of these sub-lineages might increase.

CONCLUSIONS

Consequently, the application of PHDtools has proved that this platform is accurate, user-friendly and convenient for clinical users who are deficient in bioinformatics, and the clinical monitor of SARS-CoV-2 genomes by PHDtools also highlighted the potential evolution features of current SARS-CoV-2 and indicated that the development of anti-SARS-CoV-2 agents and new-designed vaccines should incorporate the gene variations other than S gene.

Phage-bacterial evolutionary interactions: experimental models and complications

Phage treatment of bacterial infections has offered some hope even as the crisis of antimicrobial resistance continues to be on the rise. However, bacterial resistance to phage is another looming challenge capable of undermining the effectiveness of phage therapy. Moreover, the consideration of including phage therapy in modern medicine calls for more careful research around every aspect of phage study. In an attempt to adequately prepare for the events of phage resistance, many studies have attempted to experimentally evolve phage resistance in different bacterial strains, as well as train phages to evolve counter-infectivity of resistant bacterial mutants, in view of answering such questions as coevolutionary dynamics between phage and bacteria, mechanisms of phage resistance, fitness costs of phage resistance on bacteria, etc. In this review, we summarised many such studies and by careful examination, highlighted critical issues to the outcome of phage therapy. We also discuss the insufficiency of many of these in vitro studies to represent actual disease conditions during phage application, alongside other complications that exist in phage-bacterial evolutionary interactions. Conclusively, we present the exploitation of phage-bacterial interactions for successful infection managements, as well as some future perspectives to direct phage research.

The impact of an annual major recreational boating event on water quality in the Solent Strait

A long-term historical analysis of the impacts of recreational boating on marine surface water quality during a regatta (Cowes Week) in an internationally crucial waterway, the Solent Strait (Hampshire, UK) is presented. Water quality indicators studied included nitrogen concentration, bacterial indicators, and oxygen saturation, at three sampling sites at/near Cowes during 2001-2019. Findings include that sewage discharge from recreational boats is the key contributor to localised faecal contamination of marine surface waters, putting bathers and shellfisheries at risk. Bathing water quality monitoring and pollution warning systems should be strengthened prior to and during this type of regatta and access to bathing water areas may need to be restricted. These findings have implications for the regulation, future monitoring and management strategies for discharges from recreational boats during extended regattas. Adequate and affordable local facilities for recovering sewage wastewater from recreational boats should be provided alongside appropriate mechanisms for communication to sailors.

[Analysis of FBN1 genemutations in a pedigree with Marfan syndrome]

Mutations in fibrillin-1 (FBN1) were detected in an autosomal dominant Marfan syndrome (MFS) pedigree. The related phenotypes and the significance of mutation screening were discussed. Complete medical and cardiovascular examinations for all pedigree members were performed. Whole exons sequencing (WES) was used to sequence the DNA of the patients and their relatives. The potential pathogenic mutation sites were screened by bioinformatics method. Sanger sequencing was used to verify the mutation sites in the pedigree. The results showed that FBN1 missense mutation was c.6806 T>C in exon 56, resulting in isoleucine being replaced by threonine (p. Ile2269Thr). This mutation has not been reported in Chinese Han population. The occurrence of the mutations strongly correlated with the phenotypes of the patients. The results expand the mutation spectrum of FBN1, and it is helpful to further explore the molecular pathogenesis of MFS and MFS related diseases.

Microbial Profiling of Potato-Associated Rhizosphere Bacteria under Bacteriophage Therapy

Potato soft rot and wilt are economically problematic diseases due to the lack of effective bactericides. Bacteriophages have been studied as a novel and environment-friendly alternative to control plant diseases. However, few experiments have been conducted to study the changes in plants and soil microbiomes after bacteriophage therapy. In this study, rhizosphere microbiomes were examined after potatoes were separately infected with three bacteria (Ralstonia solanacearum, Pectobacterium carotovorum, Pectobacterium atrosepticum) and subsequently treated with a single phage or a phage cocktail consisting of three phages each. Results showed that using the phage cocktails had better efficacy in reducing the disease incidence and disease symptoms’ levels when compared to the application of a single phage under greenhouse conditions. At the same time, the rhizosphere microbiota in the soil was affected by the changes in micro-organisms’ richness and counts. In conclusion, the explicit phage mixers have the potential to control plant pathogenic bacteria and cause changes in the rhizosphere bacteria, but not affect the beneficial rhizosphere microbes.

A Reverse Transcription Recombinase-Aided Amplification Method for Rapid and Point-of-Care Detection of SARS-CoV-2, including Variants

The worldwide pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its emergence of variants needs rapid and point-of-care testing methods for a broad diagnosis. The regular RT-qPCR is time-consuming and limited in central laboratories, so a broad and large-scale screening requirement calls for rapid and in situ methods. In this regard, a reverse transcription recombinase-aided amplification (RT-RAA) is proposed here for the rapid and point-of-care detection of SARS-CoV-2. A set of highly conserved primers and probes targeting more than 98% of SARS-CoV-2 strains, including currently circulating variants (four variants of concerns (VOCs) and three variants of interest (VOIs)), was used in this study. With the preferred primers, the RT-RAA assay showed a 100% specificity to SARS-CoV-2 from eight other respiratory RNA viruses. Moreover, the assay here is of a high sensitivity and 0.48 copies/μL can be detected within 25 min at a constant temperature (42 °C), which can be realized on portable equipment. Furthermore, the RT-RAA assay demonstrated its high agreement for the detection of SARS-CoV-2 in clinical specimens compared with RT-qPCR. The rapid, simple and point-of-care RT-RAA method is expected to be an appealing detection tool to detect SARS-CoV-2, including variants, in clinical diagnostic applications.

Enriched Opportunistic Pathogens Revealed by Metagenomic Sequencing Hint Potential Linkages between Pharyngeal Microbiota and COVID-19

As a respiratory tract virus, SARS-CoV-2 infected people through contacting with the upper respiratory tract first. Previous studies indicated that microbiota could modulate immune response against pathogen infection. In the present study, we performed metagenomic sequencing of pharyngeal swabs from eleven patients with COVID-19 and eleven Non-COVID-19 patients who had similar symptoms such as fever and cough. Through metagenomic analysis of the above two groups and a healthy group from the public data, there are 6502 species identified in the samples. Specifically, the Pielou index indicated a lower evenness of the microbiota in the COVID-19 group than that in the Non-COVID-19 group. Combined with the linear discriminant analysis (LDA) and the generalized linear model, eighty-one bacterial species were found with increased abundance in the COVID-19 group, where 51 species were enriched more than 8 folds. The top three enriched genera were Streptococcus, Prevotella and Campylobacter containing some opportunistic pathogens. More interestingly, through experiments, we found that two Streptococcus strains, S. suis and S. agalactiae, could stimulate the expression of ACE2 of Vero cells in vitro, which may promote SARS-CoV-2 infection. Therefore, these enriched pathogens in the pharynxes of COVID-19 patients may involve in the virus-host interactions to affect SARS-CoV-2 infection and cause potential secondary bacterial infections through changing the expression of the viral receptor ACE2 and/or modulate the host’s immune system.

Genetic Polymorphism Drives Susceptibility Between Bacteria and Bacteriophages

Phage therapy has attracted much attention for the treatment of antibiotic-resistant bacteria in recent years. However, it is common for bacteria to obtain resistance capability in short time after interaction with a lytic phage, as observed in phage therapy and co-culture of host and phage in a lab. In order to understand the mechanisms behind resistance, Staphylococcus aureus AB91118 and its lytic phage LQ7 were studied as a model system. A mutant strain named R1-3-1 resistant to the ancestral phage LQ7 was isolated, and then phages experimentally evolved from LQ7 were able to kill R1-3-1. Genomes of the two bacterial strains and the three phages (LQ7, ELQ7P-10, and ELQ7P-20) were analyzed based on deep sequencing data of NGS. Analyses showed that a few mutations could be identified in R1-3-1 and the evolved phages. Instead, in all the genomes of the bacteria and the phages, there exists genetic polymorphism of minor alleles, which distributes in many functional genes. Specifically, in the AB91118-LQ7 system it was found that the unique polymorphism sites in R1-3-1 associated to metabolic pathways could be inhibited by chloramphenicol (CHL). The resistant mutant R1-3-1 could become sensitive to the phage LQ7 in the presence of CHL. Combined use of CHL and the evolved phage from 20 cycles (ELQ7P-20) could produce the least resistance when killing the bacteria AB91118. The genetic polymorphism of minor alleles would be a new mechanism to drive the co-evolution between a phage and its host, which may enable the phage and the host get ready and fast response to the selective pressure from one to the other.

Rapid genome-wide sequence typing of African swine fever virus based on alleles

Rapid and accurate molecular typing of African swine fever virus (ASFV) during outbreaks is important to reveal diversity and sourcing of ASFV. Here we present a new way to perform rapid genome-wide multi-locus sequence typing of ASFV using an allele calling based on gene by gene approach. Using open-accessed chewBBACA software, 41 publicly available ASFV genomes were analyzed to optimize the parameters to find the alleles. Alleles as many as 127 were found for building the phylogenetic trees, which covered more than 60 % of the whole genome. Then the method was used to analyze two ASFV genomes assembled from two metagenomic sequences of a swine whole blood and a swine spleen tissue collected in Wuhan, China. It reveals that the two ASFV genomes are the closest to that of Pig/HLJ/2018 strain and DB/LN/2018 strain, which were isolated earlier in China. This proved that the ASFV in Wuhan originated from the same source causing the earlier outbreaks in Heilongjiang and Liaoning province of China. This method could identify more informative genome regions that could be used for accurate typing than other genome-wide analysis, and with less demand on computing resources. It also showed tolerance to analyze ASFV draft genomes assembled directly from metagenomic sequences. Furthermore, the ASFV-specific genetic markers found by the allele calling could be translated into clinical diagnostics or can be used broadly to identify conserved putative therapeutic candidates.

Developing Children's Oral Health Assessment Toolkits Using Machine Learning Algorithm

OBJECTIVES

Evaluating children's oral health status and treatment needs is challenging. We aim to build oral health assessment toolkits to predict Children's Oral Health Status Index (COHSI) score and referral for treatment needs (RFTN) of oral health. Parent and Child toolkits consist of short-form survey items (12 for children and 8 for parents) with and without children's demographic information (7 questions) to predict the child's oral health status and need for treatment.

METHODS

Data were collected from 12 dental practices in Los Angeles County from 2015 to 2016. We predicted COHSI score and RFTN using random Bootstrap samples with manually introduced Gaussian noise together with machine learning algorithms, such as Extreme Gradient Boosting and Naive Bayesian algorithms (using R). The toolkits predicted the probability of treatment needs and the COHSI score with percentile (ranking). The performance of the toolkits was evaluated internally and externally by residual mean square error (RMSE), correlation, sensitivity and specificity.

RESULTS

The toolkits were developed based on survey responses from 545 families with children aged 2 to 17 y. The sensitivity and specificity for predicting RFTN were 93% and 49% respectively with the external data. The correlation(s) between predicted and clinically determined COHSI was 0.88 (and 0.91 for its percentile). The RMSEs of the COHSI toolkit were 4.2 for COHSI (and 1.3 for its percentile).

CONCLUSIONS

Survey responses from children and their parents/guardians are predictive for clinical outcomes. The toolkits can be used by oral health programs at baseline among school populations. The toolkits can also be used to quantify differences between pre- and post-dental care program implementation. The toolkits' predicted oral health scores can be used to stratify samples in oral health research.

KNOWLEDGE TRANSFER STATEMENT

This study creates the oral health toolkits that combine self- and proxy- reported short forms with children's demographic characteristics to predict children's oral health and treatment needs using Machine Learning algorithms. The toolkits can be used by oral health programs at baseline among school populations to quantify differences between pre and post dental care program implementation. The toolkits can also be used to stratify samples according to the treatment needs and oral health status.

Molecular cloning and functional characterisation of duck (Anas platyrhynchos) tumour necrosis factor receptor-associated factor 3

1. Tumour necrosis factor receptor-associated factor 3 (TRAF3) is a key regulator of innate immunity and acquired immunity, and has a salient anti-viral role. 2. In this experiment, the duck TRAF3 (DuTRAF3) gene was cloned according to the Anas platyrhynchos TRAF3 sequence to explore its function. The TRAF3 open reading frame contains 1704 bp that encode a protein of 567 amino acids, which contain a RING finger domain, two zinc finger motifs, a coiled-coil region, and a MATH domain. 3. Reverse transcription-polymerase chain reaction showed that DuTRAF3 was expressed in all the examined tissues, with a comparatively higher expression in the spleen and brain tissues. 4. In HEK293T cells, DuTRAF3 overexpression resulted in a significantly increased NF-κB activity and interferon (IFN)-β promoter activation. 5. Following resiquimod (R848) and poly(I:C) stimulation of duck peripheral blood mononuclear cells (PBMCs), the expressions of TRAF3 and IFN-β were significantly upregulated; in addition, following R848 stimulation, the mRNA levels of IL-6, IL-8 and IL-10 were also significantly upregulated. After infection with the Newcastle Disease Virus LaSota vaccine strain, the mRNA levels of IL-6 and IL-10 were significantly upregulated, while that of TRAF3 was downregulated. 6. These results suggest that DuTRAF3 has an important role to play in innate antiviral immune responses.

Child and Parent Demographic Characteristics and Oral Health Perceptions Associated with Clinically Measured Oral Health

OBJECTIVE

To examine child and parent reports about the child's oral health and assess the associations of these reports with clinical assessments of oral health status by dental examiners.

METHODS

Surveys with 139 items for children and 133 items for parents were administered by Audio Computer-Assisted Self-Interview Software. In addition, the Children's Oral Health Status Index (COHSI) was computed from a dental examination.

RESULTS

A total of 334 families with children ages 8 to 17 y participated at 12 dental practices in Los Angeles County. Ordinary least squares regression models were estimated separately for child and parent surveys to identify items uniquely associated with the COHSI. Ten of 139 items the children reported regarding their oral health were associated with the COHSI. The strongest associations were found for child's age, aesthetic factors (straight teeth and pleased with teeth), and cognitive factors related to perception of dental appearance (pleased/happy with the look of the child's mouth, teeth, and jaws). Nine of 133 parent items about the child's oral health were associated with the COHSI in the parent model, notably being a single parent, parent's gender, parent born in the United States, pleased or happy with the look of their child's teeth, and accessing the Internet.

CONCLUSION

These child and parent survey items have potential to be used to assess oral health status for groups of children in programs and practices in lieu of dental screenings.

KNOWLEDGE TRANSLATION STATEMENT

The paper's results inform the development of a toolkit that can be used by schools, public health agencies, and dental programs to identify children with low oral health status based on parents' and children's responses to survey items across demographic, physical, mental, and social domains. These survey items can be used to inform parents of the desirability of proactively addressing inadequacies in their child's oral health status, enabling them to more rationally address dental needs.

An let-7 KRAS rs712 polymorphism increases hepatocellular carcinoma risk

KRAS, also known as V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog, acts as an intracellular signal transducer. The oncogenic KRAS mutation is an essential step in the development of many types of human cancers, including hepatocellular carcinoma. Here we aimed to investigate the relationship between KRAS rs712 polymorphisms and hepatocellular carcinoma susceptibility. Five-hundred-and-fourteen participants were enrolled in a case-control study (262 cases and 252 normal subjects). The variants were distinguished using polymerase chain reaction-restriction fragment length polymorphism. Significantly increased HCC risk was observed to be associated with the T allele of the rs712 locus (P = 0.049, OR = 1.35, 95%CI = 1.01-1.78). Further, HCC risk with the GT genotype (P = 0.015, OR = 1.64, 95%CI = 1.08-2.50) and the TT genotype (P = 0.015, OR = 2.56, 95%CI = 1.05-6.25) in a codominant model was significantly higher than that with the GG genotype. In a dominant model, significantly increased HCC susceptibility was also associated with T allele carriers (P = 0.006, OR = 1.75, 95%CI = 1.16-2.63). Moreover, we found that the frequency of the KRAS rs712 TT genotype was significantly higher in HBV-positive HCC patients than in HBV-negative HCC patients.

Topic-Based Dissimilarity and Sensitivity Models for Translation Rule Selection

Translation rule selection is a task of selecting appropriate translation rules for an ambiguous source-language segment. As translation ambiguities are pervasive in statistical machine translation, we introduce two topic-based models for translation rule selection which incorporates global topic information into translation disambiguation. We associate each synchronous translation rule with source- and target-side topic distributions.With these topic distributions, we propose a topic dissimilarity model to select desirable (less dissimilar) rules by imposing penalties for rules with a large value of dissimilarity of their topic distributions to those of given documents. In order to encourage the use of non-topic specific translation rules, we also present a topic sensitivity model to balance translation rule selection between generic rules and topic-specific rules. Furthermore, we project target-side topic distributions onto the source-side topic model space so that we can benefit from topic information of both the source and target language. We integrate the proposed topic dissimilarity and sensitivity model into hierarchical phrase-based machine translation for synchronous translation rule selection. Experiments show that our topic-based translation rule selection model can substantially improve translation quality.

Risk perceptions for avian influenza virus infection among poultry workers, China

To determine risk for avian influenza virus infection, we conducted serologic surveillance for H5 and H9 subtypes among poultry workers in Beijing, China, 2009–2010, and assessed workers’ understanding of avian influenza. We found that poultry workers had considerable risk for infection with H9 subtypes. Increasing their knowledge could prevent future infections.

Efficient inhibition of multidrug-resistant human tumors with a recombinant bispecific anti-P-glycoprotein × anti-CD3 diabody

Overexpressing of P-glycoprotein (Pgp) has been shown to be responsible for cancer resistance to multiple chemotherapeutic agents. Immunotherapy with biological agents, such as bispecific antibodies (BsAbs), may represent a promising approach to overcome the emergence of drug resistance. Here we constructed a recombinant BsAb, a diabody, with specificities to both CD3 on human T-lymphocyte and Pgp on cancer cells. The diabody was produced in Escherichia coli in a soluble functional form and purified by an affinity chromatography with a yield of >4 mg/l culture medium in shaker flask. The diabody binds to both CD3 on T-lymphocytes and Pgp on multidrug-resistant (MDR) tumor cells with affinities that are comparable to its respective parental single chain Fv molecules. In the presence of activated human peripheral blood lymphocytes (PBLs), the diabody mediates effectively the lysis of the Pgp-overexpressing human leukemia K562/A02 and epidermoid carcinoma KBv(200) cells, but is much less potent in mediating the lysis of the parent K562 and KB cells. Further, the diabody localized selectively within the K562/A02 xenografts in mice. When combined with activated PBL, the diabody significantly inhibited the growth of K562/A02 and KBv(200), but had no effect on K562 and KB xenografts. In contrast, treatment with doxorubicin, a standard chemotherapeutic agent, only inhibited the growth of K562 and KB, but had no effect on K562/A02 and KBv(200) xenografts. Taken together, our results suggest that the anti-Pgp x anti-CD3 diabody may have a great potential in the treatment of various MDR cancers.

[Study of specific targeting cytotoxicity mediated by anti-CD(3)/anti-CD(20) Diabody]

OBJECTIVE

To study the specific targeting cytotoxicity mediated by an anti-CD(3)/anti-CD(20) diabody.

METHODS

The diabody was purified by affinity chromatography and identified by Western blot assay, size exclusion chromatography, FACS and rosetting assay; the effect of the anti-CD(3)/anti-CD(20) diabody mediated lysis of CD(20)-expressing tumor cells was assayed by (51)Cr release assay in vitro and by human B cell tumor nude mice xenograft model in vivo.

RESULTS

The anti-CD(3)/anti-CD(20) diabody could bind both Jurkat cells (CD(3)(+)) and Daudi cells (CD(20)(+)) and appeared to be potent in targeting activated peripheral blood mononuclear cell (PBMC) to lyse Daudi cells in vitro. Furthermore, it inhibited tumor growth and prolonged the survival of mice bearing xenografted Raji cells.

CONCLUSION

The diabody proved to be a potent agent for targeting peripheral blood lymphocytes to lyse CD(20) antigen expressing tumor cells in vitro and in vivo.

[The mutation of anti-CD3 antibody (HIT3a) gene and its expression]

OBJECTIVE

To improve the expression of anti-CD(3) single chain Fv (scFv) by site mutation and identify its biological activity.

METHODS

Anti-CD(3) scFv gene was mutated by PCR, the target clones were screened by both the fingerprints of DNA restriction endonuclease digestion and Western blot, the antigen-binding activity of scFv was examined by FACS, competitive inhibition was performed with (125)I-labeled HIT3a and the cytotoxic effect mediated by the anti-CD(3) scFv-activated T lymphocytes was analyzed by (51)Cr-released assays.

RESULTS

The DNA sequencing showed that the 6th amino acid of the anti-CD(3) antibody (HIT3a) heavy chain gene was mutated from E (GAG) to Q (CAG). The expression of mutated anti-CD(3) scFv (m2) was increased by 100 times higher than that of the parent scFv, and there was no difference in the Jurkat cell (CD(3)(+))-binding activity between the (m2) and parent scFv. The preliminary results of competitive assays showed that m2 could partially block the sites of CD(3)(+) Jurkat cells where the parent antibody bound to. Cytotoxicity assays demonstrated that CD(3)AK cells induced by IL-2 and m2 showed stronger cytotoxic effect than that of LAK cells induced by IL-2 alone in vitro.

CONCLUSION

By site mutation, a high expression fragment m2 of anti-CD(3) scFv antibody was obtained. The results of some experiments indicated that m2 could bind to CD(3)(+) Jurkat cells, furthermore, by co-stimulated with IL-2, it could activate peripheral T lymphocytes and induce CD(3)AK cytotoxic effect.

[The prevention of infection complicating acute necrotizing pancreatitis:an experimental study]

OBJECTIVE

To observe the effects of 5 intervention measures on infection complicating acute necrotizing pancreatitis (ANP) in dogs and rats.

METHODS

A lethal model of ANP was reproduced by infusion of artificial bile into the biliopancreatic duct. Animals were divided randomly into: ANP group (no treatment); Chinese medicine group ("Qing Yi Tang"); Bifidobacterium mixture group; purgation group (MgSO(4)); selective decontamination of the digestive tract (SDD) group; and somatostatin group. The pancreas and intestine were observed morphologically and tight junction on ileum epithelia was assessed on cryofracture replicas. Blood and/or tissue levels of DAO and D-lactic acid and uric contents of lactulose/mannitol (L/M), served as indicators of gut barrier function, were measured at various time points. Intestinal flora and incidence of bacterial translocation (BT) to organs were examined.

RESULTS

In early stage of ANP, mucosal and epithelial tight junction damage and flora disturbance occurred in the gut. In addition, the gut barrier function indicators deteriorated. The BT rates were as high as 78.6% (canine) and 59.5% (rat). Treatment with Chinese medicine markedly improved gut barrier function and reduced BT rate (32.1% - 37.0%). Having similar purgative response as Chinese medicine, MgSO4 did not show any beneficial effect on gut barrier protection and the incidence of BT was not reduced. In bifidobacterium mixture and SDD group, flora balance was preserved well and similar results as Chinese medicine were obtained. The BT rates of these two groups decreased to 33.9% and 33.3%, respectively. Somatostatin markedly blunted pancreatic tissue injury and ameliorated gut barrier damage during early phase of ANP. All intervention measures except for purgation also decreased mortalities (14.3% - 35.3%, compared with 58.8% of the no treatment group).

CONCLUSIONS

Treatment with Chinese medicine, bifidobacterium mixture, SDD and somatostatin attenuated gut barrier damage and BT after ANP, and could be used to prevent secondary infection after ANP, but purgation alone is not effective.

[Experimental study on treatment of viral myocarditis in mice by integrated traditional Chinese and Western Medicine]

OBJECTIVE

To clarify the effects of Astragalus Membranaceus (AM) combined with taurine and/or coenzyme Q10(CoQ10) on coxsackievirus B3 (CVB3) murine myocarditis.

METHODS

Viral myocarditis model was created by intraperitoneal inoculation with CVB3 solution and were treated by saline, AM, taurine, CoQ10, AM + taurine, AM + CoQ10, AM + taurine + CoQ10, respectively. The mortality, ECG, CVB3-RNA in myocardium and myocardial histopathologic changes were observed.

RESULTS

AM combined with taurine and CoQ10 could significantly reduce the mortality of the mice and the incidence of abnormal ECG at acute stage. CVB3-RNA was significantly reduced in AM treated group, especially in AM + taurine group. No anti-virus effect was found in CoQ10 group. All drugs could lighten myocardial histopathologic changes and the effect could be enhanced by combined treatment.

CONCLUSIONS

AM, taurine and CoQ10 have some curative effects on CVB3 murine myocarditis, AM combined with taurine and CoQ10 is the best.

[An experimental study on curative effect of Chinese medicine qing yi tang in acute necrotizing pancreatitis]

OBJECTIVE

To observe the curative effect of the traditional Chinese medicine (TCM) Qing Yi Tang (QYT) in acute necrotizing pancreatitis (ANP).

METHODS

Twenty three dogs were randomly divided into 3 groups. In control group (n = 7), animals underwent laparotomy only. In ANP group (n = 8), acute necrotizing pancreatitis was induced by injection of 0.5 ml/kg 5% sodium taurocholate with 300 u/kg trypsin into the pancreatic duct. While in TCM group (n = 8) were fed everyday with QYT after onset of ANP. All animals were sacrified 7 days later and organs were gathered and cultured. Mucosal and luminal floras of the intestine were analysed. Pancreas and ileal mucosa were examined histologically and ultra-microscopically, the levels of lipopolysaccharide (LPS) and amylase in blood were determined.

RESULTS

In TCM groups, histologic and ultra-structural damages in pancreas and ileal mucosa were much milder as compared with those of ANP group. In ANP group, there was a significant increase of E. coli and bacterocoids, and a significant decrease of bifidobacteria, lactobacilli and enterococci in the intestinal mucosa, while in TCM groups, these changes were alleviated significantly (P < 0.05 or P < 0.01). As compared with ANP group, the bacterial translocation (BT) rate was reduced from 100% to 50%, and the counts of translocated bacteria were decreased 10-40 times, the levels of LPS and amylase reduced 2 to 3 times.

CONCLUSION

TCM recipe QYT showed their protective effects on gut barrier function by alleviating the damage of intestinal mucosa and microecologic disturbance following acute pancreatitis. As a result, the chances of BT and enterogenic infection declined. These preparation might be promising in the prophylaxis and treatment of infection complicating ANP.

Isolation and partial characterization of a complementary protein from the mycoparasite Piptocephalis virginiana that specifically binds to two glycoproteins at the host cell surface

Immunofluorescence microscopy was used to detect in the mycoparasite Piptocephalis virginiana the presence of a complementary glycoprotein that binds specifically to the host cell surface glycoproteins b and c, reported earlier from our laboratory. Germinated spores of P. virginiana treated with cell wall extract of the host Mortierella pusilla, primary antibody prepared against cell wall glycoproteins b and c, and fluorescein isothiocyanate (FITC) – goat anti-rabbit IgG conjugate showed fluorescence. Immunobinding analysis identified from the mycoparasite a protein of 100 kDa that binds with the host glycoproteins b and c, separately as well as collectively. Its purification was achieved by (i) 60% ammonium sulfate precipitation, (ii) heat treatment, (iii) Sephadex G-100 gel filtration, and (iv) preparative polyacrylamide gel electrophoresis (PAGE). The purity was ascertained by sodium dodecyl sulphate (SDS) – PAGE and Western blot analysis. Positive reaction to periodic acid – Schiff s reagent revealed its glycoprotein nature, and mannose was identified as a major sugar component. The specificity of the polyclonal antibody raised against electrophoretically purified complementary protein in rabbit was confirmed by dot immunobinding and Western blot analyses. Immunofluorescence microscopy revealed surface localization of the protein on the germ tubes of P. virginiana. Fluorescence was also observed at the surface of the germinated spores and hyphae of the host M. pusilla, after treatment with complementary protein from P. virginiana, primary antibody prepared against the complementary protein, and FITC – goat anti-rabbit IgG conjugate.Key words: biotrophic mycoparasite, cell surface agglutinin, glycoprotein immunobinding, immunofluorescence, mucoraceous host.

[Measurement of urinary content of lactulose and mannitol by gas chromatography as an index of permeability of the gut]

We established lactulose-mannitol(L-M) measurement method by gas chromatography and 9202 computer data processing system to test intestinal permeability. The urine output of L-M was in linear correlation to its sample concentration within working range. In an animal model of acute pancreatitis, lactulosesecretion increased in urine, together with increased L/M ratio. The measurement of lactulose-mannitol intestinal permeability by our method might serve as a predictor for early diagnosis of endogenous infection and sepsis.

Effect of verapamil on Ca2+ influx and CVB3-RNA replication in cultured neonatal rat heart cells infected with CVB3

The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 (CVB3) -RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P < 0.01) by verapamil (1 mumol/L) after infection of heart cells for 48 h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (1 mumol/L and 10 nmol/L) at the same time for 48 h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P < 0.05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e.g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn't a sensible choice for therapy in early stage of virus infection with cardiac symptoms.