Application of enhanced recovery after surgery in perioperative nursing care of elderly patients with hip and knee arthroplasty: A systematic review and meta-analysis.

BACKGROUND: To collect data from randomized controlled trials (RCTs) to evaluate the effects of enhanced recovery after surgery on postoperative recovery of elderly patients who underwent hip or knee arthroplasty. METHODS: The search was limited to studies published prior to January 1, 2023, in the electronic databases of Cochrane, Embase, Ovid Medline, Proquest, PubMed, Scopus, Web of Science, and Chinese databases, including China National Knowledge Internet (CNKI) and SinoMed. All relevant data were collected from the studies that met the inclusion criteria. The outcome variables were recovery of joint function and incidence of complications. STATA software (version 14.0) was used for the meta-analysis. RESULTS: A total of 44 published studies met the inclusion criteria. The cumulative data included 2203 cases receiving enhanced recovery after surgery (ERAS), and 2173 cases receiving traditional recovery after surgery (non-ERAS). The meta-analysis showed that the VAS score was significantly lower in the ERAS group than in the non-ERAS group (P < .01), and there were fewer incidences of complications in the ERAS group than in the control group (P < .01). CONCLUSIONS: ERAS significantly reduced pain and the incidence of complications in elderly patients who had undergone joint replacement surgery.

Effect of residual volume after surgery of the discoid lateral meniscus on tibiofemoral joint biomechanics: a finite element analysis.

BACKGROUND: The purpose of this study was to investigate the influence of different residual meniscus volume on the biomechanics of tibiofemoral joint after discoid lateral meniscus (DLM) surgery by finite element analysis. METHODS: A knee joint model was established based on CT and MRI imaging data. The DLM model was divided into five regions according to conventional meniscectomy, with volumes of 15%, 15%, 15%, 15%, 15%, and 40% for each region. Additionally, the DLM model was divided into anterior and posterior parts to obtain ten regions. The DLM was resected according to the design scheme, and together with the intact discoid meniscus, a total of 15 models were obtained. Finite element analysis was conducted to assess shear and pressure trends on the knee joint. RESULTS: The study observed significant changes in peak shear stress and compressive stress in the lateral meniscus and lateral femur cartilage. As the meniscus volume decreased, there was an increase in these stresses. Specifically, when the meniscus volume reduced to 40%, there was a sharp increase in shear stress (302%) and compressive stress (152%) on the meniscus, as well as shear stress (195%) and compressive stress (157%) on the lateral femur cartilage. Furthermore, the model grouping results showed that preserving a higher frontal volume in the meniscus model provided better biomechanical advantages. CONCLUSION: The use of finite element analysis has demonstrated that preserving more than 55% of the meniscus volume is necessary to prevent a significant increase in joint stress, which can potentially lead to joint degeneration. Additionally, it is crucial to preserve the front volume of the DLM in order to achieve improved knee biomechanical outcomes.

Effect of mesenchymal stromal cells transplantation on the outcomes of patients with knee osteoarthritis: A systematic review and meta-analysis.

Cell therapy has been explored as a new regenerative treatment for osteoarthritis in the field of regenerative medicine. However, the efficacy of stem cell transplantation from different sources for the treatment of knee osteoarthritis (KOA) remains controversial. This study integrates and evaluates the previously published data of stem cell transplantation for KOA to explore the curative effect of different stem cells. We conducted a meta-analysis of randomized controlled trials on stem cell therapy for KOA. Measures of efficacy included Visual Analog Scale (VAS), Lequesne index, Lysholm Knee Scoring Scale (LKSS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). Joint injury was evaluated through the Whole-Organ Magnetic Resonance Imaging Score (WORMS) system. We analyzed 16 studies involving 875 KOA patients. The stem cell treatment showed significant VAS reduction from the third month onwards. Subgroup analysis suggested the most significant pain relief at different postoperative months came from adipose-derived and umbilical cord-derived stem cells. Autologous adipose tissue resulted in better pain alleviation compared with allogenic. However, autologous bone marrow stem cells did not show increased pain relief over allogeneic ones. Combination therapy (HA and/or PRP) showed no effect. Autologous adipose-derived stem cells demonstrate the most effective recovery of knee joint function. In WORMS assessment, there was no significant difference between the stem cell group and control. Stem cell transplantation proved safe and effective for KOA treatment. Different sources stem cells have a good effect on alleviating knee joint pain, restoring knee joint function, and minimizing patient trauma.

Protective efficacy of Toxoplasma gondii GRA12 or GRA7 recombinant proteins encapsulated in PLGA nanoparticles against acute Toxoplasma gondii infection in mice.

Background: Toxoplasma gondii is an apicomplexan parasite that affects the health of humans and livestock, and an effective vaccine is urgently required. Nanoparticles can modulate and improve cellular and humoral immune responses. Methods: In the current study, poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles were used as a delivery system for the T. gondii dense granule antigens GRA12 and GRA7. BALB/c mice were injected with the vaccines and protective efficacy was evaluated. Results: Mice immunized with PLGA+GRA12 exhibited significantly higher IgG, and a noticeable predominance of IgG2a over IgG1 was also observed. There was a 1.5-fold higher level of lymphocyte proliferation in PLGA+GRA12-injected mice compared to Alum+GRA12-immunized mice. Higher levels of IFN-g and IL-10 and a lower level of IL-4 were detected, indicating that Th1 and Th2 immune responses were induced but the predominant response was Th1. There were no significant differences between Alum+GRA7-immunized and PLGA+GRA7-immunized groups. Immunization with these four vaccines resulted in significantly reduced parasite loads, but they were lowest in PLGA+GRA12-immunized mice. The survival times of mice immunized with PLGA+GRA12 were also significantly longer than those of mice in the other vaccinated groups. Conclusion: The current study indicated that T. gondii GRA12 recombinant protein encapsulated in PLGA nanoparticles is a promising vaccine against acute toxoplasmosis, but PLGA is almost useless for enhancing the immune response induced by T. gondii GRA7 recombinant protein.

Inactivation Performance of Pseudorabies Virus as African Swine Fever Virus Surrogate by Four Commercialized Disinfectants.

This study was based on similar physicochemical characteristics of pseudorabies virus (PRV) and African swine fever virus (ASFV). A cellular model for evaluation of disinfectants was established with PRV as an alternative marker strain. In the present study, we evaluated the disinfection performance of commonly used commercialized disinfectants on PRV to provide a reference for the selection of good ASFV disinfectants. In addition, the disinfection (anti-virus) performances for four disinfectants were investigated based on the minimum effective concentration, onset time, action time, and operating temperature. Our results demonstrated that glutaraldehyde decamethylammonium bromide solution, peracetic acid solution, sodium dichloroisocyanurate, and povidone-iodine solution effectively inactivated PRV at concentrations 0.1, 0.5, 0.5, and 2.5 g/L on different time points 30, 5, 10, and 10 min, respectively. Specifically, peracetic acid exhibits optimized overall performance. Glutaraldehyde decamethylammonium bromide is cost effective but requires a long action time and the disinfectant activity is severely affected by low temperatures. Furthermore, povidone-iodine rapidly inactivates the virus and is not affected by environmental temperature, but its application is limited by a poor dilution ratio such as for local disinfection of the skin. This study provides a reference for the selection of disinfectants for ASFV.

The impact of COVID-19 non-pharmaceutical interventions on HIV care continuum in China: An interrupted time series analysis.

Background: China implemented strict non-pharmaceutical interventions to contain COVID-19 at the early stage. We aimed to evaluate the impact of COVID-19 on HIV care continuum in China. Methods: Aggregated data on HIV care continuum between 1 January 2017 and 31 December 2020 were collected from centers for disease control and prevention at different levels and major infectious disease hospitals in various regions in China. We used interrupted time series analysis to characterize temporal trend in weekly numbers of HIV post-exposure prophylaxis (PEP) prescriptions, HIV tests, HIV diagnoses, median time intervals between HIV diagnosis and antiretroviral therapy (ART) initiation (time intervals, days), ART initiations, mean CD4+ T cell counts at ART initiation (CD4 counts, cells/µL), ART collections, and missed visits for ART collection, before and after the implementation of massive NPIs (23 January to 7 April 2020). We used Poisson segmented regression models to estimate the immediate and long-term impact of NPIs on these outcomes. Findings: A total of 16,780 PEP prescriptions, 1,101,686 HIV tests, 69,659 HIV diagnoses, 63,409 time intervals and ART initiations, 61,518 CD4 counts, 1,528,802 ART collections, and 6656 missed visits were recorded during the study period. The majority of outcomes occurred in males (55·3-87·4%), 21-50 year olds (51·7-90·5%), Southwestern China (38·2-82·0%) and heterosexual transmission (47·9-66·1%). NPIs was associated with 71·5% decrease in PEP prescriptions (IRR 0·285; 95% CI 0·192-0·423), 36·1% decrease in HIV tests (0·639, 0·497-0·822), 32·0% decrease in HIV diagnoses (0·680, 0·511-0·904), 59·3% increase in time intervals (1·593, 1·270-1·997) and 17·4% decrease in CD4 counts (0·826, 0·746-0·915) in the first week during NPIs. There was no marked change in the number of ART initiations, ART collections and missed visits during the NPIs. By the end of 2020, the number of HIV tests, HIV diagnoses, time intervals, ART initiations, and CD4 counts reached expected levels, but the number of PEP prescriptions (0·523, 0·394-0·696), ART collections (0·720, 0·595-0·872), and missed visits (0·137, 0·086-0·220) were still below expected levels. With the ease of restrictions, PEP prescriptions (slope change 1·024/week, 1·012-1·037), HIV tests (1·016/week, 1·008-1·026), and CD4 counts (1·005/week, 1·001-1·009) showed a significant increasing trend. Interpretation: HIV care continuum in China was affected by the COVID-19 NPIs at various levels. Preparedness and efforts to maintain the HIV care continuum during public health emergencies should leverage collaborations between stakeholders. Funding: Natural Science Foundation of China.

High prevalence of sexually transmitted infections and risk factors among HIV-positive individuals in Yunnan, China.

BACKGROUND: Yunnan has the highest rates of HIV in China. Other treatable sexually transmitted infections (STIs) are associated with accelerated HIV transmission and poor ART outcomes, but are only diagnosed by syndromic algorithms. METHODS: We recruited 406 HIV-positive participants for a cross-sectional study (204 ART-naive and 202 receiving ART). Blood samples and first-voided urine samples were collected. Real-time polymerase chain reaction methods were used for diagnosing Chlamydia trachomatis (CT), Neisseria gonorrhea (NG) and Mycoplasma genitalium (MG). Syphilis and herpes simplex virus type 2 (HSV-2) tests were also performed. RESULTS: Among the 406 participants, the overall prevalence of STIs was 47.0% and 45.1% in ART-naive individuals and 49.0% in individuals receiving ART, respectively. The testing frequencies were 11.6% (11.8% vs. 11.4%), 33.2% (29.4% vs. 37.1%), 3.2% (3.4% vs. 3.0%), 2.0% (3.4% vs. 0.5%) and 4.7% (6.4% vs. 3.0%) for active syphilis, HSV-2, CT, NG and MG, respectively. The percentage of multiple infections in both groups was 10.8% (22/204) in ART-naive participants and 9.9% (20/202) in participants receiving ART. Female sex, an age between 18 and 35 years, ever injecting drugs, homosexual or bisexual status, HIV/HBV coinfection, and not receiving ART were identified as risk factors. Self-reported asymptomatic patients were not eliminated from having a laboratory-diagnosed STI. CONCLUSIONS: The STI prevalence was 47.0% (45.1% vs. 49.0%), and HSV-2, syphilis and MG were the most common STIs in HIV-infected individuals. We found a high prevalence (6.4%) of MG in ART-naive individuals. HIV-positive individuals tend to neglect or hide their genital tract discomfort; thus, we suggest strengthening STI joint screening and treatment services among HIV-infected individuals regardless of whether they describe genital tract discomfort.

Outcomes of Methadone Maintenance Therapy Combined with Rilpivirine/Efavirenz in Treatment-Naive HIV-Infected Patients.

BACKGROUND: Injecting drugs is associated with a high risk of HIV infection, alongside the risk of a drug overdose and mental health problems. OBJECTIVE: To evaluate the effect of methadone maintenance treatment (MMT) combined with rilpivirine (RPV)-based regimens on drug use of HIV individuals. METHODS: This study was a prospective, open-label, controlled, drug-drug interaction trial at a single center for 24 weeks. Participants on stable MMT were randomly divided into two groups administered RPV/TDF/3TC (RPV group) and EFV/TDF/3TC (EFV group), respectively. Adjustment doses of methadone were monitored for 12 weeks. HIV-1 RNA was used to evaluate the effects of antiretroviral therapy at week 24. Acute opioid withdrawal-, drug craving questionnaire- and MOSHIV scales were used to assess study outcomes. RESULTS: 22 and 18 cases of HIV-infected drug users were recruited in the RPV and EFV groups, respectively. Thirty-one cases had completed monitoring and clinical evaluation at week 24. In the RPV and EFV groups, 32% and 56% of the participants had methadone dose adjustment, respectively, indicating a significantly lower rate in the RPV group. The rates of individuals with HIV RNA levels from 50-500 copies/ml were 94% (RPV group) and 90% (EFV group). The drug craving questionnaire scale scores decreased in both groups. After one week of treatments, acute opioid withdrawal scale scores increased in both groups, with no significant difference between them. CONCLUSION: Concomitant administration of RPV does not significantly affect methadone and could decrease withdrawal symptoms. An RPV-based regimen may be used as first-line treatment in IDUs with HIV infection.

Efficacy and safety of lower dose tenofovir disoproxil fumarate and efavirenz versus standard dose in HIV-infected, antiretroviral-naive adults: a multicentre, randomized, noninferiority trial.

Reduced doses of antiretroviral (ARV) drugs may lower toxicity while preserving efficacy. We aimed to evaluate the efficacy of reduced doses of both tenofovir disoproxil fumarate (TDF) and efavirenz for the treatment of HIV-1 infection. In this open-label, non-inferiority trial, HIV-1-infected antiretroviral-naive adults were randomly assigned to receive either a lower dose anti-retroviral regimen comprised of TDF (200 mg), efavirenz (400 mg), and standard dose lamivudine (300 mg) or the standard dose regimen. The primary endpoint was the proportion of participants with HIV-1 RNA≤ 50 copies/mL at week 48 using a non-inferiority margin of -10%. At week 48, 79 of 92 (85.9%) participants in the lower dose regimen group and 78 of 92 (84.8%) in the standard dose regimen group achieved HIV-1 RNA≤ 50 copies/mL (treatment difference 1.1%, 95% CI -9.1 to 11.3) in the intention-to-treat analysis. Drug-related adverse events occurred more frequently in the participants receiving the standard dose regimen compared with the lower dose one (63.0% vs 80.4%). Changes in estimated glomerular filtration rate and bone mineral density were comparable between the two groups. The non-inferior efficacy and better safety profile of the lower dose ARV regimen support its use as alternative initial therapy for HIV-1 infected patients.

Regulatory Patterns of Crp on Monensin Biosynthesis in Streptomyces cinnamonensis.

Monensin, produced by Streptomyces cinnamonensis, is a polyether ionophore antibiotic widely used as a coccidiostat and a growth-promoting agent in agricultural industry. In this study, cyclic AMP receptor protein (Crp), the global transcription factor for regulation of monensin biosynthesis, was deciphered. The overexpression and antisense RNA silencing of crp revealed that Crp plays a positive role in monensin biosynthesis. RNA sequencing analysis indicated that Crp exhibited extensive regulatory effects on genes involved in both primary metabolic pathways and the monensin biosynthetic gene cluster (mon). The primary metabolic genes, including acs, pckA, accB, acdH, atoB, mutB, epi and ccr, which are pivotal in the biosynthesis of monensin precursors malonyl-CoA, methylmalonyl-CoA and ethylmalonyl-CoA, are transcriptionally upregulated by Crp. Furthermore, Crp upregulates the expression of most mon genes, including all PKS genes (monAI to monAVIII), tailoring genes (monBI-monBII-monCI, monD and monAX) and a pathway-specific regulatory gene (monRI). Enhanced precursor supply and the upregulated expression of mon cluser by Crp would allow the higher production of monensin in S. cinnamonensis. This study gives a more comprehensive understanding of the global regulator Crp and extends the knowledge of Crp regulatory mechanism in Streptomyces.

Effect of rilpivirine on the pharmacokinetics of methadone in HIV-Infected Chinese patients.

Background: The combination of rilpivirine with methadone may result in complex interactions secondary to the induction of oxidative metabolism by rilpivirine. Research design and methods: TMC278IFD4007 was a single-center, prospective, open-label, multiple-dose study with 12 HIV-infected Chinese participants. The objective was to evaluate the potential effect of rilpivirine on the pharmacokinetics of methadone. The participants received a daily dose of 25 mg rilpivirine for 11 days with individualized methadone ranging from 25 to 100 mg. Pharmacokinetic studies of methadone were conducted on day 1 and 11. Opiate withdrawal symptoms were evaluated. Results: A large inter-subject variability was noted in methadone pharmacokinetics. Rilpivirine increased methadone minimum and maximum plasma concentrations (Cmin; Cmax) and area under the plasma concentration-time curve versus methadone alone (least-square mean ratio; 90% confidence interval) by 5% (1.05; 0.46, 2.39), 5% (1.05; 0.73, 1.52), and 6% (0.75; 0.74, 1.50) as measured in S-methadone, and 5% (1.05; 0.50, 2.22), 5% (1.05; 0.74, 1.50), and 5% (1.05; 0.76, 1.46) as measured in R-methadone, respectively. No opioid withdrawal symptoms or methadone dose adjustments were reported. Co-administration was well tolerated without serious adverse effects or discontinuations. Conclusion: Concomitant administration of rilpivirine was unlikely to have significant effects on the pharmacokinetics of methadone.

Tolerable and curable treatment in HIV/HCV co-infected patients using anti-HCV direct antiviral agents: a real-world observation in China.

OBJECTIVE: No brand direct-acting antiviral agents (DAAs) are available for treatment of HIV-1/HCV co-infected patients in China. This study aimed to observe the therapeutic efficacy and safety of generic DAAs for affected Chinese patients. DESIGN: Real-world setting to elucidate whether DAAs were tolerated and effective in HIV-1/HCV co-infected patients. METHODS: 176 HIV-1/HCV co-infected patients received anti-HCV DAA treatment together with ART regimens for HIV infection. Among the 176 patients, 99 patients were treated with SOF + DCV ± RBV, 60 patients were treated with SOF + LDV ± RBV, and 17 patients received SOF + RBV ± Peg-IFN regimens, for 12 or 24 weeks, respectively. The primary endpoint was undetectable HCV RNA 12 weeks after therapy was completed (SVR12). Data pertaining to safety and adverse events were analyzed. RESULTS: 151/176 HIV-1/HCV co-infected patients finished the treatment and 12-week follow-up. SVR12 for the patients treated with regimens of SOF + DCV, SOF + DCV+RBV, SOF + Peg-IFN+RBV, SOF + RBV, SOF + LDV, and SOF + LDV+RBV for 12 or 24 weeks was 100% (75/75), 100% (11/11), 100% (14/14), 100% (2/2), 95.2% (40/42), and 100% (7/7), respectively. HIV-1/HCV co-infected patients with liver cirrhosis achieved well SRV12. Notably, there was no significant difference in adverse effects among patients with different baseline CD4+ T-cell count in those who received DAA regimens with or without Peg-IFN and RBV. CONCLUSION: We showed generic SOF + DCV and SOF + LDV regimens were well tolerated and with high efficiency. Patient's baseline CD4+ T-cell count did not exhibit significant difference in adverse effects.

Genetic and pathogenic characterization of a novel reassortant mammalian orthoreovirus 3 (MRV3) from a diarrheic piglet and seroepidemiological survey of MRV3 in diarrheic pigs from east China.

Mammalian orthoreoviruses (MRVs), which cause gastrointestinal and respiratory illness, have been isolated from a wide variety of mammalian species including bats, minks, pigs and humans. Here we report the isolation and genetic and pathogenic characterization of a novel MRV type 3 (MRV3), named MRV-ZJ2013, from the diarrheic feces of piglets in Zhejiang province, China. Genomic and phylogenetic analysis shows that MRV-ZJ2013 may have originated from reassortments among mink, bat, and pig MRVs, suggesting the hypothesis that interspecies transmission has occurred in pig herds. Neonatal piglets infected with MRV-ZJ2013 displayed mild clinical signs such as poor appetite and soft feces, but vomiting and diarrhea were not observed. Fecal virus shedding was detected only in three out of six piglets, each for one- or two-day post-infection. In contrast, piglets inoculated with a virulent porcine epidemic diarrhea virus (PEDV) strain as the control group had severe signs characterized by acute vomiting and watery diarrhea. These findings suggest that the virulence of MRV-ZJ2013, if any, was likely not significant compared to that of PEDV. A seroepidemiological survey of MRV by means of an indirect enzyme-linked immune-sorbent assay (ELISA) based on a recombinant MRV3 capsid protein sigma1 as antigen revealed a high seroprevalence (77%) in 1037 samples from diarrheic pigs of different ages from 24 herds in seven provinces of east China between 2015 and 2016, indicating that MRV3 is endemic in pig herds in China, and may contribute collectively to enteric disease along with other porcine pathogens.

Sero-Molecular Epidemiology of Japanese Encephalitis in Zhejiang, an Eastern Province of China.

BACKGROUND: Sporadic Japanese encephalitis (JE) cases still have been reported in Zhejiang Province in recent years, and concerns about vaccine cross-protection and population-level immunity have been raised off and on within the public health sphere. Genotype I (GI) has replaced GIII as the dominant genotype in Asian countries during the past few decades, which caused considerable concerns about the potential change of epidemiology characteristics and the vaccine effectiveness. The aim of this study was to investigate the prevalence of JE neutralizing antibody and its waning antibody trend after live attenuated JE vaccine immunization. Additionally, this study analyzed the molecular characteristics of the E gene of Zhejiang Japanese encephalitis virus (JEV) strains, and established genetic relationships with other JEV strains. METHODOLOGY/PRINCIPAL FINDINGS: A total of 570 serum specimens were sampled from community population aged from 0 to 92 years old in Xianju county of Zhejiang Province in 2013-2014. Microseroneutralization test results were analyzed to estimate the population immunity and to observe antibody dynamics in vaccinated children. E genes of 28 JEV strains isolated in Zhejiang Province were sequenced for phylogenetic tree construction and molecular characteristics analysis with other selected strains. Positive JE neutralizing antibody rates were higher in residents ≥35 years old (81%~98%) and lower in residents <35 years old (0~57%). 7 or 8 years after the 2nd live attenuated vaccine dose, the antibodies against for 4 different strains with microseroneutralization test were decreased by 55%~73% on seropositive rates and by 25%~38% on GMTs respectively. JEV strains isolated in recent years were all grouped into GI, while those isolated in the 1980s belonged to GIII. On important amino acid sites related to antigenicity, there was no divergence between the Zhejiang JE virus strains and the vaccine strain (SA14-14-2). CONCLUSION/SIGNIFICANCES: JE neutralizing antibody positive rates increase in age ≥10 years old population, likely reflecting natural infection or natural boosting of immunity through exposure to wild virus. JE seropositivity rates were quite low in <35 years old age groups in Zhejiang Province. Waning of neutralizing antibody after live attenuated vaccine immunization was observed, but the clinical significance should be further investigated. Both the peripheral antibody response and genetic characterization indicate that current live attenuated JE vaccine conferred equal neutralizing potency against GI or GIII of wild strains. GI has replaced GIII as the dominant genotype in Zhejiang in the past few decades. Although the chance of exposure to wild JE virus has reduced, the virus still circulates in nature; therefore, it is necessary to implement immunization program for children continually and to conduct surveillance activity periodically.

Enterovirus 71 infection causes severe pulmonary lesions in gerbils, meriones unguiculatus, which can be prevented by passive immunization with specific antisera.

Neurogenic pulmonary edema caused by severe brainstem encephalitis is the leading cause of death in young children infected by Enterovirus 71 (EV71). However, no pulmonary lesions have been found in EV71-infected transgenic or non-transgenic mouse models. Development of a suitable animal model is important for studying EV71 pathogenesis and assessing effect of therapeutic approaches. We had found neurological disorders in EV71-induced young gerbils previously. Here, we report severe pulmonary lesions characterized with pulmonary congestion and hemorrhage in a gerbil model for EV71 infection. In the EV71-infected gerbils, six 21-day-old or younger gerbils presented with a sudden onset of symptoms and rapid illness progression after inoculation with 1×105.5 TCID50 of EV71 via intraperitoneal (IP) or intramuscular (IM) route. Respiratory symptoms were observed along with interstitial pneumonia, pulmonary congestion and extensive lung hemorrhage could be detected in the lung tissues by histopathological examination. EV71 viral titer was found to be peak at late stages of infection. EV71-induced pulmonary lesions, together with severe neurological disorders were also observed in gerbils, accurately mimicking the disease process in EV71-infected patients. Passive transfer with immune sera from EV71 infected adult gerbils with a neutralizing antibody (GMT=89) prevented severe pulmonary lesion formation after lethal EV71 challenge. These results establish this gerbil model as a useful platform for studying the pathogenesis of EV71-induced pulmonary lesions, immunotherapy and antiviral drugs.

[Effects of leukemia inhibitory factor combined with basic fibroblast growth factor on proliferation and differentiation of human bone marrow mesenchymal stem cells].

OBJECTIVE: To study the effects of leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) on the proliferation and differentiation of human bone marrow mesenchymal stem cells (hBMSCs). METHODS: hBMSCs at passage 4 were divided into 4 groups according to different culture conditions: cells were treated with complete medium (a-MEM containing 10%FBS, group A), with complete medium containing 10 ng/mL LIF (group B), with complete medium containing 10 ng/mL bFGF (group C), and with complete medium containing 10 ng/mL LIF and 10 ng/mL bFGF (group D). The growth curves of hBMSCs at passage 4 in different groups were assayed by cell counting kit 8; cellular morphologic changes were observed under inverted phase contrast microscope; the surface markers of hBMSCs at passage 8 including CD44, CD90, CD19, and CD34 were detected by flow cytometry. RESULTS: The cell growth curves of each group were similar to the S-shape; the cell proliferation rates in 4 groups were in sequence of group D > group C > group B > group A. Obvious senescence and differentiation were observed very early in group A, cells in group B maintained good cellular morphology at the early stage, with slow proliferation and late senescence; a few cells in group C differentiated into nerve-like cells, with quick proliferation; and the cells in group D grew quickly and maintained cellular morphology of hBMSCs. The expressions of CD44 and CD90 in groups A and C at passage 8 cells were lower than those of groups B and D; the expressions of CD19 and CD34 were negative in 4 groups, exhibiting no obvious difference between groups. CONCLUSION: LIF combined with bFGF can not only maintain multiple differentiation potential ofhBMSCs, but also promote proliferation of hBMSCs.

[Mechanism of chlorogenic acid on apoptosis of rat nucleus pulposus cells induced by oxidative stress].

OBJECTIVE: To investigate the mechanism of chlorogenic acid (CGA) on H2O2-induced apoptosis in the rat nucleus pulposus cells (NPCs). METHODS: NPCs were isolated from SD rats and cultured in vitro. Cultured cells (P3) were randomly divided into normal control group, H2O2 group, CGA + H2O2 group, CGA group and LY294002 pretreatment group. The apoptosis and ROS production of rNPCs was detected by flow cytometry. The expressions of p-Akt, BCL-2 and Akt were analyzed by Western blot. RESULTS: Compared with normal control group, in the H2O2 group, the production of ROS and the apoptosis rate significantly increased in rNPCs; CGA treatment inhibited ROS production and cell apoptosis, while increased the expression of p-Akt and BCL-2; LY294002, a PI3Kinse inhibitor, not only decreased the expression of p-Akt and BCL-2, but also obviously increased ROS production and cell apoptosis. CONCLUSION: Chlorogenic acid can protect NPCs against apoptosis by oxidative stress through decreasing reactive oxygen species production and increasing anti-apoptotic protein BCL-2 expression in NPCs by activation of PI3K-Akt signaling pathways.

Antigenic and immunogenic properties of truncated VP28 protein of white spot syndrome virus in Procambarus clarkii.

Previous studies identify VP28 envelope protein of white spot syndrome virus (WSSV) as its main antigenic protein. Although implicated in viral infectivity, its functional role remains unclear. In the current study, we described the production of polyclonal antibodies to recombinant truncated VP28 proteins including deleted N-terminal (rVP28ΔN), C-terminal (rVP28ΔC) and middle (rVP28ΔM). In antigenicity assays, antibodies developed from VP28 truncations lacking the N-terminal or middle regions showed significantly lowered neutralization of WSSV in crayfish, Procambarus clarkii. Further immunogenicity analysis showed reduced relative percent survival (RPS) in crayfish vaccinating with these truncations before challenge with WSSV. These results indicated that N-terminal (residues 1-27) and middle region (residues 35-95) were essential to maintain the neutralizing linear epitopes of VP28 and responsible in eliciting immune response. Thus, it is most likely that these regions are exposed on VP28, and will be useful for rational design of effective vaccines targeting VP28 of WSSV.

[Genotype of hantavirus in Zhejiang province].

OBJECTIVE: To identify the genotype and clades of hantavirus (HV) in Zhejiang province. METHODS: The partial S and M segment of the HV in Zhejiang province were amplified with RT-PCR using genotype-specific primers, and then were sequenced and compared with other known hantaviruses. RESULTS: The genotype of 11 strains were HTNV and other 7 strains were SEOV by homology and phylogenesis analysis, yet the clade distribution was significantly different among foci of Zhejiang with 5 clades of HTNV and 3 clades of SEOV. There also existed special clade of HTNV named ZNB-1, ZNB-2, A3 and of SEOV named Gou3, ZJ5. The homology of M segments of ZNB-1 and ZNB-2 with other HTNV clades were 69.7%-74.0% except Nc167, A3 with other HTNV clades were 73.6%-76.3% except B78. CONCLUSION: Zhejiang province is co-circulating with HTN and SEO. Say the least of the clades are 5 of HTNV and 3 of SEOV and there also existed special clade of HTNV and SEOV.

Enterovirus 71-induced neurological disorders in young gerbils, Meriones unguiculatus: development and application of a neurological disease model.

A reliable disease model mimicking Enterovirus 71 (EV71) infection in humans is essential for understanding pathogenesis and for developing a safe and effective vaccine. Commonly used rodent models including mouse or rat models are not suitable for vaccine evaluation because the rodents are resistant to EV71 infection after they reach the age of 6 days. In this study, 21-day-old gerbils inoculated intraperitoneally (IP) with a non mouse-adapted EV71 strain developed neurological lesion-related signs including hind limb paralysis, slowness, ataxia and lethargy similar to those of central nervous system (CNS) infection of EV71 in humans. The infected gerbils eventually died of the neurological lesions and EV71 could be isolated from lung, liver, spleen, kidney, heart, spinal cord, brain cortex, brainstem and skeletal muscle. Significantly high virus replication was detected in spinal cord, brainstem and skeletal muscle by cellular analysis, real-time quantitative PCR (RT-PCR) and immunohistochemical staining. Histopathologic changes such as neuronal degeneration, neuronal loss and neuronophagia were observed in spinal cord, brain cortex, brainstem, and skeletal muscle along with necrotizing myositis and splenic atrophy. Gerbils that received two doses of inactive whole-virus vaccine showed no EV71-specific symptoms after challenged with EV71. In contrast, gerbils that received mock vaccination died of EV71-induced neuropathology after challenged with EV71. The result indicates that gerbils can serve as a reliable disease model for evaluating safety and efficacy of EV71 vaccine.