Objective To conifgure an immunoabsorption column for hepatitis B virus.
Methods Being activated by epichlorohydrin, the human antibody HBsAb-IgG was bound to the carrier of agarose gel. The configuration process was as follows: the synthesis of epoxide matrix, the synthesis and activation of amino matrix, the synthesis of aldehydic matrix, the synthesis of immunoabsorption matrix, the end capping and reduction of unbound aldehydic, the blocking of unbound mass and the iflling of the column. Results The bound rate of activated agarose gel and antibody HBsAb-IgG is 85.07%. By plasma adsorption experiment, it is revealed that the immunoabsorption column can absorb and eliminate 58.97%of HBsAg and 53.1%of hepatitis B virus particles in extracorporeal plasma.
Conclusions The immunoabsorption column for hepatitis B virus can absorb and eliminate HBsAg and hepatitis B virus particles in extracorporeal plasma.

Objective To investigate the 23 bp and 12 bp insertion/deletion (indel) mutations within the bovine prion protein (PRNP) gene in Chinese dairy cows, and to detect the associations of two indel mutations with BSE susceptibility and milk performance.
Methods Based on bovine PRNP gene sequence, two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed. The PCR ampliifcation and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations. Moreover, based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study, the corrections between the two indel mutations and BSE susceptibility were tested, as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.
Results In the analyzed Chinese Holstein population, the frequencies of two“del”alleles in 23 bp and 12 bp indel muations were more frequent. The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del. From the estimated r2 and D’ values, two indel polymorphisms were linked strongly in the Holstein population (D’=57.5%, r2=0.257). Compared with the BSE-affected cattle populations from the reported data, the signiifcant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations (P<0.05 or P<0.01). Similarly, there were signiifcant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle (P<0.05 or P<0.01). Moreover, association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population, but no signiifcant differences were found (P>0.05).
Conclusions These observations revealed that the inlfuence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits, which layed the foundation for future selection of resistant animals, and for improving health conditions for dairy breeding against BSE in China.

Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected.
Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum.
Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024.
Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.

Objective The aim of the study was to evaluate the characteristics of HIV drug-genotypic resistance among patients taking ifrst-line ARV regimens using polymerase chain reaction and sequencing, and guide to design optimal ARV regimens for these patients.
Methods HIV reverse transcriptase-encoded gene was ampliifed with RT-PCR and ampliifed PCR products were aligned and comparatively analyzed with HIV resistance database to ifnd drug-resistance mutations.
Results Twenty-eight PCR products were amplified and sequenced successfully in 30 serum samples of recruited HIV-infected patients with virologic failure. The resistance rate was 96%, mutations in NRT region were found in 26 patients (93%), while mutations in NNRT region were found in 27 patients (96%). M184V was the most common mutation (86%), K65R was selected in 14%of recruited individuals and TAMs occurred in 50%of patients, which resulted in resistance to NRTIs. Y181C and V179D were the most common mutations in NNRTIs and prevalence was 43%(12/28) and 36%(10/28), respectively, which resulted in cross-resistance to NNRTIs due to low-genetic barrier.
Conclusions Virologic failure may occur in long-term administration of ifrst-line ARV regimens, and drug-resistance mutations can be found in these patients, which resulted in resistance to ifrst-line ARV regimens. We emphasized that HIV viral load assay and resistance assay were important tools to guide healthcare workers to design an optimal second-line ARV regimens for HAART-experienced individuals with virologic failure.

Objective To compare the efifcacy of peginterferon alfa-2a (PEGASYS) plus ribavirin (RBV) with interferon alfa-2a plus RBV, and evaluate the safety. Methods Total of 117 patients with chronic hepatitis C were enrolled to receive either PEGASYS (135 μg or 180 μg) subcutaneously once per week, plus RBV (800 mg-1 200 mg) per day for 48 weeks (79 patients, PEGASYS group), or 5 million units of interferon alfa-2a subcutaneously every other day, plus RBV as above dosage for 48 weeks (38 patients, IFNα group). Results Sixty-three of 79 (79.7%) patients reached sustained virological response (SVR) in PEGASYS group, while 14 of 38 (36.8%) patients reached SVR in IFNα group. PEGASYS group was associated with a higher rate of virologic response than IFNα group at week 4, 12, 36, 48 and week 72. Sustained normalization of serum ALT concentrations at week 36, 48 and week 72 was also more common in PEGASYS group than in IFNα group. Baseline levels of ALT and HCV RNA had no effect on SVR in either PEGASYS group or IFNαgroup. Both groups were similar in the frequency and severity of adverse events. Conclusions PEGASYS plus RBV produced similar adverse events but higher rate of SVR. Meanwhile, complications should be prevented and treated promptly in order to increase compliances and effects.

Objective Nucleos(t)ide analogues (NAs) na?ve chronic hepatitis B(CHB) patients were given rescue combination therapy after drug resistance to lamivudine or adefovir. Evolution of HBV mutation patterns and its impact on antiviral effects were studied.
Methods Total of 142 na?ve CHB patients treated with lamivudine were randomly divided into two groups when lamivudine resistance occurred. One group was added with adefovir, the other was switched to entecavir and adefovir. Seventy-two na?ve CHB patients treated with adefovir were randomly divided into two groups when adefovir resistance occurred. One group was added with lamivudine, the other was added with entecavir. HBV polymerase reverse transcriptase mutations associated with resistance were analyed before and after 48 weeks of rescue therapy, respectively.
Results The mutation patterns of M204V/I, M204V+L180M were predominantly found in CHB patients after lamivudine resistance. Meanwhile, the entecavir resistance mutation patterns were also detected. Therefore, patients with lamivudine resistance could develop more diverse drug resistance mutations if they were switched to entecavir and adefovir. The mutation patterns of rtA181 were predominantly found in CHB patients after adefovir resistance and rescure therapy with add-on entecavir was more effective than with add-on lamivudine Conclusions Resistance mutation analysis chould help to choose NAs, reduce resistance and ehance antiviral effects.

Objective To investigate the epidemiologic features of an outbreak of SARS that occurred in a single diabetes room of a general hospital in Beijing in late March 2003.
Methods Field investigation was carried out in the ward, the nursing log and the hospitalization medical record of correlative patients were consulted. SARS-CoV in serum specimen from SARS patient was detected by PCR. Results The room where SARS outbreak occurred was on the 13th lfoor of the 16-story main ward building. There were 6 beds in the room, living with 6 female patients (aged 45-67) who were all hospitalized due to type 2 diabetes. On March 24, 2003, Patient 1 began to have a fever and cough, chest X-ray showed pneumonia. Five and six days later, Patient 2 and Patient 3 began to have a fever, respectively. Finally, all of these 3 patients died. Their beds were all at the same side of the room, and the other 3 patients at the opposite side were not infected. Serum SARS CoV-RNA of the Patient 3 was positive by nest-PCR. The daughter-in-law of Patient 1 who accompanied Patient 1 by the bedside several days, mainly near the window, upwind of Patient 1, was not infected. Medical staff, family members and visitors of the 6 patients were not infected.
Conclusions This outbreak was not transmitted by aerosol. The distance droplets travels could be up to 3.43 meters. Droplet spread has direction, and the droplets direction of propagation is closely related with the wind direction and speed. Those at the downwind position of SARS patients were susceptible to be infected. Medical staff wore face masks and good natural ventilation of this ward building may be important reasons for the prevention of infection.

Objective To realize the characteristics of“zheng”differentiation-treatment for hand, foot and mouth disease (HFMD), a new methodology of syndrome differentiation for different stages of HFMD has been explored.
Methods Total of 2 325 cases with HFMD were recorded by distributing them into exterior syndrome stage, interior syndrome stage, severe syndrome stage and recovered syndrome stage, respectively, and the main symptoms and subsidiary symptoms of different stages of HFMD have been observed. The major and minor pathogenesis of HFMD in different stages were obtained, and compared with the “2010 Guideline for the Diagnosis and Treatment of HFMD”.
Results It was found that the major pathogenesis of exterior stage was deifned as“the invation of the wen-evil to the defender of the body with the collaterals got involved”, and the minor as“qi deifciency”;in interior stage,“the fury of Gan-Yang”was the main pathogenesis, and“qi in chaos and qi deifciency”was the minor;in severe syndrome stage,“the damage of heart, liver and lung”was the main pathogenesis, and“qi in chaos”was the minor;and the pathogenesis of recovered stage was“qi-yin deficiency”. Compared with the“2010 Guideline for the Diagnosis and Treatment of HFMD”, it showed that“the obstruction of the fei-pi qi by the mixture of shi-re evil”and“the mixture of shi-re”in vivo was quite dififcult to be explained in completely different context in the general situation; in the severe stage, the TCM clinical characteristics of syndrome differentiation might lose;in the early acute severe cases, the phenomenon that xin-yang and fei-qi almost ran out was dififcult to be observed, then, the line between the severe and the acute severe became vague.
Conclusions The theory of syndrome differentiation by stages of HFMD was reasonable in the actual situation of clinical description on HFMD which was expected to be further tested and widely applied in the“zheng”differentiation-treatment of HFMD in the future.

Objective To analyze the clinical and laboratory features of patients with mild and severe HFMD to identify early predictive or diagnostic markers for severe cases. Methods Samples of feces, nasopharyngeal-swab specimens, peripheral blood, serum and cerebral spinal lfuid were collected. Postmortem pathological examination was conducted on 2 dead patients with complication due to neurogenic pulmonary edema. Reverse transcription-polymerase chain-reaction (RT-PCR), culture and isolation of enterovirus 71 (EV71) were performed to detect EV71 infection. Both univariate and multivariate logistic analysis were used to identify factors associated with severe cases. Results EV71 was mainly responsible for HFMD. In this study, 5 isolated EV71 strains belonged to C4 gene subtype. Compared with mild patients, EV71-RNA detection rate was higher and CoxA16 detection rate was lower among severe patients (P < 0.01). Inlfammatory cell inifltration in the lung, cardiac and liver tissues were mild by postmortem pathological examination. It was found that body temperature, vomitting, limb tremor, neutrophil, blood glucose and EV71 infection were significantly related to the severe cases by univariate logisticanalysis. However, after multivariate logistic regression analysis, only vomiting (OR 16.1, CI 2.3-110.5,P < 0.01) and limb tremor (OR 117.6, CI 13.8-1004.5,P < 0.01) were signiifcantly and independently correlated with the severe cases. Conclusions EV71 was mainly responsible for HFMD, particularly for severe cases. Vomiting and limb tremor were predictive markers for severe cases.

Background and Aims Recently, epidemiology studies of hepatitis E in different areas are attracted more attention. Extensive studies of prevalent status and clinical manifestations could help us to broaden our knowledge, so as to excellently prevent and treat hepatitis E. The study analyzed the epidemiological characteristics and clinical features of 394 cases of sporadic acute hepatitis E (AHE) in Southwest of China from 2008 to 2010. Methods The clinical data of 394 cases with sporadic AHE in Southwest of China from 2008 to 2010 were reviewed. Results In the 394 cases with sporadic AHE, the ratio of male/female was 1.432∶1, and the mean age was (31.53 ± 18.12) years. Totally, 94 (23.86%) patients aged under 18, 271 (68.78%) patients aged between 18 and 60, and 29 (7.36%) patients aged above 60. The incidence rate was signiifcantly increased in summer (P = 0.000), especially in May (14.72%) and July (13.71%). In addition, the characteristics of occupation and ethnic group distribution were migrant laborers (106/394, 26.90%) and Han people (365/394, 92.64%). The length of stay, incidence of jaundice, the peak value of total bilirubin and alanine aminotransferase in male patients were all higher than those in female patients signiifcantly (P < 0.05). The prolonged length of stay, decreased levels of ALT/ALB/CHE, increased levels of TBil, and increased incidence of jaundice and fatigue were associated with older age signiifcantly (P < 0.05). The differences in peak values of total bilirubin (TBil), total bile acid (TBA), glutamyltransferase (GGT), cholinesterase (CHE) between AHE group and the groups of AHE accompanied respectively by chronic hepatitis B (CHB), acute alcoholic fatty liver (AFL), nonalcoholic fatty liver disease (NAFLD) were signiifcant (P<0.05). In addition, no signiifcant difference was found in length of stay and biochemical indexes among anti-HEV-IgG positive group, anti-HEV-IgM positive group and anti-HEV-IgM/IgG both positive group (P>0.05). Conclusions Four epidemiological characteristics, including aged between 18 and 60, male, summer and migrant laborers, are found to be associated with acute hepatitis E. The prognosis of AHE in the majority of patients was favorable, but aged above 60 years and coexistence with CHB, AFL and NAFLD could be considerede as the factors inducing the infaust prognosis.