Nitrogen oxides(NO_(x))are crucial in tropospheric photochemical ozone(O_(3))production and oxidation capacity.Currently,the widely used NO_(x)measurement technique is chemiluminescence(CL)(CL-NO_(x)),which tends to o...Nitrogen oxides(NO_(x))are crucial in tropospheric photochemical ozone(O_(3))production and oxidation capacity.Currently,the widely used NO_(x)measurement technique is chemiluminescence(CL)(CL-NO_(x)),which tends to overestimate NO_(2)due to atmospheric oxidation products of NO_(x)(i.e.,NO_(z)).We developed and characterized a NO_(x)measurement system using the cavity attenuated phase shift(CAPS)technique(CAPS-NO_(x)),which is free from interferences with nitrogen-containing species.The NO_(x)measured by the CAPS-NO_(x)and CL-NO_(x)analyzers were compared.Results show that both analyzers showed consistent measurement results for NO,but the NO_(2)measured by the CAPS-NO_(x)analyzer(NO_(2)_CAPS)was mostly lower than that measured by the CL-NO_(x)analyzer(NO_(2)_CL),which led to the deviations in O_(3)formation sensitivity regime and O_(x)(=O_(3)+NO_(2))sources(i.e.,regional background and photochemically produced O_(x))determined by the ozone production efficiencies(OPE)calculated from NO_(2)_CL and NO_(2)_CAPS.Overall,OPE_CL exceeded OPE_CAPS by 18.9%,which shifted 3 out of 13 observation days from the VOCs-limited to the transition regime when judging using OPE_CL,as compared to calculations using OPE_CAPS.During the observation period,days dominated by regional background O_(x)accounted for 46%and 62%when determined using NO_(2)_CL and NO_(2)_CAPS,respectively.These findings suggest that the use of the CL-NO_(x)analyzer tends to underestimate both the VOCs-limited regime and the regional background O_(x)dominated days.The newly built CAPS-NO_(x)analyzer here can promote the accurate measurement of NO_(2),which is meaningful for diagnosing O_(3)formation regimes and O_(x)sources.展开更多
BACKGROUND Improving the intraoperative and postoperative performance of laparoscopic hepatectomy was quite a challenge for liver surgeons.AIM To determine the benefits of indocyanine green(ICG)fluorescence imaging in...BACKGROUND Improving the intraoperative and postoperative performance of laparoscopic hepatectomy was quite a challenge for liver surgeons.AIM To determine the benefits of indocyanine green(ICG)fluorescence imaging in patients with hepatocellular carcinoma(HCC)who underwent laparoscopic hepatectomy during and after surgery.METHODS We retrospectively collected the clinicopathological data of 107 patients who successfully underwent laparoscopic hepatectomy at Zhongshan Hospital(Xiamen),Fudan University from June 2022 to June 2023.Whether using the ICG fluorescence imaging technique,we divided them into the ICG and non-ICG groups.To eliminate statistical bias,a 1:1 propensity score matching analysis was conducted.The comparison of perioperative outcomes,including inflammationrelated markers and progression-free survival,was analyzed statistically.RESULTS Intraoperatively,the ICG group exhibited lower blood loss,a shorter surgical time,lower hepatic inflow occlusion(HIO)frequency,and a shorter total HIO time.Postoperatively,the participation of ICG resulted in a shorter duration of hospitalization(6.5 vs 7.6 days,P=0.03)and postoperative inflammatory response attenuation(lower neutrophil-lymphocyte ratio on the first day after surgery and platelet-lymphocyte ratio on the third day,P<0.05).Although the differences were not significant,the levels of all inflammation-related markers were lower in the ICG group.The rates of postoperative complications and the survival analyses,including progression-free and overall survivals showed no significant difference between the groups.CONCLUSION The involvement of ICG fluorescence imaging may lead to improved perioperative outcomes,especially postoperative inflammatory response attenuation,and ultimately improve HCC patients’recovery after surgery.展开更多
Avian metapneumovirus(aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses. Subtype B aMPV has recently become the domi...Avian metapneumovirus(aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses. Subtype B aMPV has recently become the dominant epidemic strain in China. We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate. The safety test showed that after the 30th passage, the LN16-A strain was fully attenuated, as clinical signs of infection and histological lesions were absent after inoculation.The LN16-A strain did not revert to a virulent strain after five serial passages in chickens. The genomic sequence of LN16-A differed from that of the parent wild-type LN16(wtLN16) strain and had nine amino acid mutations. In chickens, a single immunization with LN16-A induced robust humoral and cellular immune responses, including the abundant production of neutralizing antibodies, CD4^(+) T lymphocytes, and the Th1(IFN-γ) and Th2(IL-4 and IL-6)cytokines. We also confirmed that LN16-A provided 100% protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation. Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.展开更多
African swine fever(ASF)caused by the ASF virus(ASFV)is a highly contagious disease of pigs and wild boars.Currently,there are no safe,effective commercial vaccines available.The genome of ASFV HLJ/18 contains more th...African swine fever(ASF)caused by the ASF virus(ASFV)is a highly contagious disease of pigs and wild boars.Currently,there are no safe,effective commercial vaccines available.The genome of ASFV HLJ/18 contains more than 180 genes,including a few virulence-related genes.Identifying these key virulence genes through individual deletion and subsequent pathogenicity testing in pigs is a laborious process.In addition,some ASFV genes are indispensable for viral replication and cannot be deleted.Over the past 30 years,scientists have confirmed that certain ASFV genes particularly those host antiviral innate immune responses,are associated with the virulence of ASFV strains.Although knockout of these genes does not impact viral replication,it does attenuate the virulence of ASFV in pigs.Pigs immunized with these live attenuated vaccine candidates can provide partial or complete protection.Based on these findings,we propose a new concept that ASFV immunomodulatory genes involved in type I interferon(IFN)production,IFN-JAK-STAT signaling,inflammatory responses,cell death(involved in apoptosis,necrosis,and pyroptosis),and autophagy may be related to the pathogenicity of ASFV.An unbiased screening may identify more ASFV immunomodulatory or multifunctional genes,simplifying the confirmation of ASFV virulence-related genes.In line with these theories,we have identified MGF505-7R and H240R as key virulence genes determining the pathogenicity of the ASFV HLJ/18 strain.Deletion of MGF505-7R,H240R alone or both attenuate the virulence of ASFV HLJ/18 in pigs,providing a paradigm for developing attenuated live vaccines from basic research results.展开更多
Alzheimer’s disease(AD)is a complex neurodegenerative condition.5α-epoxyalantolactone(5α-EAL),a eudesmane-type sesquiterpene isolated from the herb of Inula macrophylla,has various pharmacological effects.This work...Alzheimer’s disease(AD)is a complex neurodegenerative condition.5α-epoxyalantolactone(5α-EAL),a eudesmane-type sesquiterpene isolated from the herb of Inula macrophylla,has various pharmacological effects.This work supposed to investigate the improved impact of 5α-EAL on cognitive impairment.5α-EAL inhibited the generation of nitric oxide(NO)in BV-2 cells stimulated with lipopolysaccharide(LPS)with an EC50 of 6.2μM.5α-EAL significantly reduced the production of prostaglandin E2(PGE2)and tumor necrosis factor-α(TNF-α),while also inhibiting the production of cyclooxygenase-2(COX-2)and inducible nitric oxide synthase(iNOS)proteins.The ability of 5α-EAL to penetrate the blood-brain barrier(BBB)was confirmed via a parallel artificial membrane permeation assay.Scopolamine(SCOP)-induced AD mice model was employed to assess the improved impacts of 5α-EAL on cognitive impairment in vivo.After the mice were pretreated with 5α-EAL(10 and 30 mg/kg per day,i.p.)for 21 days,the behavioral experiments indicated that the administration of the 5α-EAL could alleviate the cognitive and memory impairments.5α-EAL significantly reduced the AChE activity in the brain of SCOP-induced AD mice.In summary,these findings highlight the beneficial effects of the natural product 5α-EAL as a potential bioactive compound for attenuating cognitive deficits in AD due to its pharmacological profile.展开更多
Human Enterovirus 71(EV71)has emerged as one of the predominant causative agents of hand,foot and mouth disease(HFMD)with global impact.Despite the inactivated vaccine being licensed,other vaccine candidates based on ...Human Enterovirus 71(EV71)has emerged as one of the predominant causative agents of hand,foot and mouth disease(HFMD)with global impact.Despite the inactivated vaccine being licensed,other vaccine candidates based on advanced technology platforms are under development.In this report,we rationally designed and constructed two DNA-launched live attenuated vaccine candidates(pDL-EV71)under the control of specific promoters.In vitro and in vivo transfection with pDL-EV71 driven by the CMV promoter successfully yielded fully infectious EV71.More importantly,the administration of pDL-EV71 did not cause clinical symptoms following intracranial or intramuscular inoculation in neonatal and IFNα/βR/mice,demonstrating its safety profile.Moreover,a single-dose or two-dose immunization with pDL-EV71 elicited robust neutralizing antibodies against EV71 as well as an antigen-specific cellular response in mice.A single-dose immunization with 10μg of pDL-EV71 conferred complete protection against lethal EV71 infection in neonates born to immunized maternal mice.Overall,our present results demonstrate that pDL-EV71 is a safe and effective vaccine candidate against EV71 for further development.展开更多
The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this s...The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this study,we generated a full-length infectious cDNA clone of the H2 strain using in-fusion techniques.The recovered H2 strain(H2ic)from the cDNA clone exhibited an efficient replication in both the hepatoma cell line Huh7.5.1 and the 2BS cell line used for vaccine production,similar to the parental H2 strain.Additionally,H2ic did not cause disease in Ifnar1-/- C57 mice,consistent with the H2 strain.To explore the cell-adaptive mutations of the H2 strain,chimeric viruses were generated by replacing its non-structural proteins with corresponding regions from H2w using the infectious cDNA clone as a genetic backbone.The chimeric viruses carrying the 3C or 3D proteins from H2w showed decreased replication in Huh7.5.1 and 2BS cell lines compared to H2ic.Other chimeric viruses containing the 2B,2C,or 3A proteins from H2w failed to be recovered.Furthermore,there were no significant differences in disease manifestation in mice between H2ic and the recovered chimeric viruses.These results demonstrate that adaptive mutations in the 2B,2C,and 3A proteins are essential for efficient replication of the H2 strain in cell cultures.Mutations in the 3C and 3D proteins contribute to enhanced replication in cell cultures but did not influence the attenuated phenotypes in mice.Together,this study presents the first reverse genetic system of the H2 strain and identifies viral proteins essential for adaptation to cell cultures.展开更多
[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.Fals...[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.展开更多
Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenom...Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis(FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli(APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.展开更多
In this article, we study reconstruction of nonuniform attenuated SPECT data and present analytic reconstruction formulae which are similar to Novikov＇s inversion formula. Furthermore, we extend Natterer＇s results.
Hypoxia（low oxygen level） is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation...Hypoxia（low oxygen level） is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation of hypoxia-inducible factor 1（HIF-1）.Hypoxia interferes degradation of HIF-1 alpha subunit（HIF-1α）, leading to stabilisation of HIF-1α, heterodimerization with HIF-1 beta subunit（HIF-1β） and subsequent activation of HIF-1 pathway. Apical periodontitis（periapical lesion） is a consequence of endodontic infection and ultimately results in destruction of tooth-supporting tissue, including alveolar bone. Thus far, the role of HIF-1 in periapical lesions has not been systematically examined. In the present study, we determined the role of HIF-1 in a wellcharacterised mouse periapical lesion model using two HIF-1α-activating strategies, dimethyloxalylglycine（DMOG） and adenovirusinduced constitutively active HIF-1α（CA-HIF1 A）. Both DMOG and CA-HIF1 A attenuated periapical inflammation and tissue destruction. The attenuation in vivo was associated with downregulation of nuclear factor-κappa B（NF-κB） and osteoclastic gene expressions. These two agents also suppressed NF-κB activation and subsequent production of proinflammatory cytokines by macrophages. Furthermore, activation of HIF-1α by DMOG specifically suppressed lipopolysaccharide-stimulated macrophage differentiation into M1 cells, increasing the ratio of M2 macrophages against M1 cells. Taken together, our data indicated that activation of HIF-1 plays a protective role in the development of apical periodontitis via downregulation of NF-κB, proinflammatory cytokines, M1 macrophages and osteoclastogenesis.展开更多
Neuroinflammation is recognized as an important pathogenic factor for aging and related cognitive disorders. Mitogen-activated protein kinase and nuclear factor kappa B signaling pathways may mediate neuroinflammation...Neuroinflammation is recognized as an important pathogenic factor for aging and related cognitive disorders. Mitogen-activated protein kinase and nuclear factor kappa B signaling pathways may mediate neuroinflammation. Saponins from Panax japonicus are the most abundant and bioactive members in rhizomes of Panaxjaponicus, and show anti-inflammatory activity. However, it is not known whether saponin from Panaxjaponicus has an anti-inflammatory effect in the aging brain, and likewise its underlying mechanisms. Sprague-Dawley rats were divided into control groups （3-, 9-, 15-, and 24-month-old groups） and saponins from Panaxjaponicus-treated groups. Saponins from Panaxjaponicus-treated groups were orally administrated saponins from Panaxjaponicus at three doses of 10, 30, and 60 mg/kg once daily for 6 months until the rats were 24 months old. Immunohistochemical staining and western blot assay results demonstrated that many microglia were activated in 24-month-old rats compared with 3- and 9-month-old rats. Expression of interleukin-1β, tumor necrosis factor-a, cyclooxygenase-2, and inducible nitric oxide synthase increased. Each dose of saponins from Panaxjaponicus visibly suppressed microglial activation in the aging rat brain, and inhibited expression levels of the above factors. Each dose of saponins from Panax japonicus markedly diminished levels of nuclear factor kappa B, IKBa, extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38. These results confirm that saponins from Panaxjaponicus can mitigate neuroinflammation in the aging rat brain by inhibition of the mito- gen-activated protein kinase and nuclear factor kappa B signaling pathways.展开更多
African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commerci...African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commercial vaccine is available because of the complexity of ASFV or biosecurity concerns.Live attenuated viruses that are naturally isolated or genetically manipulated have demonstrated reliable protection against homologous ASFV strain challenge.In the present study,a mutant ASFV strain with the deletion of ASFV MGF-110-9L(ASFV-D9L)was generated from a highly virulent ASFV CN/GS/2018 parental strain,a genotypeⅡASFV.Relative to the parental ASFV isolate,deletion of the MGF-110-9L gene significantly decreased the ability of ASFV-D9L to replicate in vitro in primary swine macrophage cell cultures.The majority of animals inoculated intramuscularly with a low dose of ASFV-D9L(10 HAD50)remained clinically normal during the 21-day observational period.Three of five ASFV-D9L-infected animals displayed low viremia titers and low virus shedding and developed a strong virus-specific antibody response,indicating partial attenuation of the ASFV-D9L strain in pigs.The findings imply the potential usefulness of the ASFV-D9L strain for further development of ASF control measures.展开更多
To investigate the immune responses to the attenuated Mycoplasma hyopneumoniae 168 strain vaccine, 8-15 d old piglets were immunized with M. hyopneurnoniae 168 strain vaccine by intrapulmonic route. And the specific I...To investigate the immune responses to the attenuated Mycoplasma hyopneumoniae 168 strain vaccine, 8-15 d old piglets were immunized with M. hyopneurnoniae 168 strain vaccine by intrapulmonic route. And the specific IgG antibody in serum, lymphoproliferation, IFNT, and specific secretory IgA （SIgA） antibody in bronchoalveolar lavage fluid were detected on 30 and 60 d post-immunization （DPI）, respectively. On 60 DPI, all the pigs except for those in health control group were challenged with a field M. hyopneumoniae strain JS. Necropsy was performed on 30 d post-challenge （DPC）. The results showed that IFN7 and specific SIgA were stimulated on surface of respiratory tract after immunization. And peripheral blood mononuclear cells could also be proliferated about 1.81 and 2.12 fold on 30 and 60 DPI when stimulated by M. hyopneumoniae protein in vitro. However, no serum IgG antibody against M. hyopneumoniae was detected during the whole immune phage. After challenge, vaccinated pigs were observed with only very slight histological lesion in individual lobes. None of vaccinated pigs showed any clinical signs. While the unvaccinated pigs from challenge control group showed varying degrees of clinical sign and severe macroscopical lesion of mycoplasmal pneumonia of swine （MPS）. The result suggested that the attenuated M. hyopneumoniae 168 strain vaccine inoculated by intrapulmonic route could activate the systemic cellular immunity, the local mucosal immunity and IFNγ secretion in respiratory tract to against M. hyopneumoniae infection in piglets.展开更多
Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine...Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain （SS1） as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups （including body weight, gastric inflammation, etc.） were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.展开更多
AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1...AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.展开更多
In this work, the image reconstruction in π-scheme short-scan single-photon emission computed tomography （SPECT） with nonuniform attenuation is derived in its most general form when π-scheme short-scan SPECT entai...In this work, the image reconstruction in π-scheme short-scan single-photon emission computed tomography （SPECT） with nonuniform attenuation is derived in its most general form when π-scheme short-scan SPECT entails data acquisition over disjoint angular intervals without conjugate views totaling to π radians. The reconstruction results are based on decomposition of Novikov＇s inversion operator into three parts bounded in the L2 sense. The first part involves the measured partial data; the second part is a skew-symmetric operator; the third part is a symmetric and compact contribution. It is showed firstly that the operators involved belong to L（L^2（B）. Furthermore numerical simulations are conducted to demonstrate the effectiveness of the developed method.展开更多
Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in...Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.展开更多
Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect human...Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect humans. There is a lack of efficient vaccines against this disease and the occurrence of antibiotic resistance may render drug therapies ineffective. In this study, gene deletion mutant(ΔSEZ) in pathogenicity islands SeseCisland_4 was constructed. The mutant ΔSEZ had a 52-fold decrease in 50% lethal dose(LD_(50)) and had less capacity to adhere epithelial cells. Importantly, immunization of mice with attenuated vaccine ΔSEZ at the dose of 10~2 colony-forming units(CFU) mL^(–1) elicited a significant humoral antibody response, with an antibody titer of 1:12 800. Therefore, 10~2 CFU mL^(–1) might be used as the appropriate immune dose for the attenuated vaccine ΔSEZ, which provided mice with efficient protection against virulent SEZ. In addition, the hyperimmune sera against 10~2 CFU m L–1 attenuated vaccine ΔSEZ could confer significant protection against virulent SEZ infection in the passive immunization experiment and exhibited efficient bactericidal activity in the whole blood assay. Meanwhile, no viable bacteria was detected in blood when mice were immunized with ΔSEZ at the dose of 10~2 CFU mL^(–1) via hypodermic injection. Thereafter, the mutant ΔSEZ at the dose of 10~2 CFU mL^(–1) could confer significant protection in mice and had less negative effects on host, which could be an effective attenuated vaccine candidate for the prevention of SEZ.展开更多
Human respiratory syncytial virus(RSV)infection is the leading cause of lower respiratory tract illness(LRTI),and no vaccine against LRTI has proven to be safe and effective in infants.Our study assessed attenuated re...Human respiratory syncytial virus(RSV)infection is the leading cause of lower respiratory tract illness(LRTI),and no vaccine against LRTI has proven to be safe and effective in infants.Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice.The constructed recombinant plasmids harbored(5′to 3′)a T7 promoter,hammerhead ribozyme,RSV Long strain antigenomic cDNA with cold-passaged(cp)mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain(A2cpts)or further combined with SH gene deletion(A2cptsΔSH),HDV ribozyme(δ),and a T7 terminator.These vectors were subsequently co-transfected with four helper plasmids encoding N,P,L,and M2-1 viral proteins into BHK/T7-9 cells,and the recovered viruses were then passaged in Vero cells.The rescued recombinant RSVs(rRSVs)were named rRSV-Long/A2cp,rRSV-Long/A2cpts,and rRSV-Long/A2cptsΔSH,respectively,and stably passaged in vitro,without reversion to wild type(wt)at sites containing introduced mutations or deletion.Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed temperature-sensitive(ts)phenotype in vitro and in vivo,all rRSVs were significantly attenuated in vivo.Furthermore,BALB/c mice immunized with rRSVs produced Th1-biased immune response,resisted wtRSV infection,and were free from enhanced respiratory disease.We showed that the combination ofΔSH with attenuation(att)mutations of cpts contributed to improving att phenotype,efficacy,and gene stability of rRSV.By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains,we have laid an important foundation for the development of RSV live attenuated vaccines.展开更多
基金supported by the Natural Science Foundation of Guangdong Province(No.2020A1515110526)the Key-Area Research and Development Programof Guangdong Province(No.2020B1111360003)the National Natural Science Foundation of China(No.42305096).
文摘Nitrogen oxides(NO_(x))are crucial in tropospheric photochemical ozone(O_(3))production and oxidation capacity.Currently,the widely used NO_(x)measurement technique is chemiluminescence(CL)(CL-NO_(x)),which tends to overestimate NO_(2)due to atmospheric oxidation products of NO_(x)(i.e.,NO_(z)).We developed and characterized a NO_(x)measurement system using the cavity attenuated phase shift(CAPS)technique(CAPS-NO_(x)),which is free from interferences with nitrogen-containing species.The NO_(x)measured by the CAPS-NO_(x)and CL-NO_(x)analyzers were compared.Results show that both analyzers showed consistent measurement results for NO,but the NO_(2)measured by the CAPS-NO_(x)analyzer(NO_(2)_CAPS)was mostly lower than that measured by the CL-NO_(x)analyzer(NO_(2)_CL),which led to the deviations in O_(3)formation sensitivity regime and O_(x)(=O_(3)+NO_(2))sources(i.e.,regional background and photochemically produced O_(x))determined by the ozone production efficiencies(OPE)calculated from NO_(2)_CL and NO_(2)_CAPS.Overall,OPE_CL exceeded OPE_CAPS by 18.9%,which shifted 3 out of 13 observation days from the VOCs-limited to the transition regime when judging using OPE_CL,as compared to calculations using OPE_CAPS.During the observation period,days dominated by regional background O_(x)accounted for 46%and 62%when determined using NO_(2)_CL and NO_(2)_CAPS,respectively.These findings suggest that the use of the CL-NO_(x)analyzer tends to underestimate both the VOCs-limited regime and the regional background O_(x)dominated days.The newly built CAPS-NO_(x)analyzer here can promote the accurate measurement of NO_(2),which is meaningful for diagnosing O_(3)formation regimes and O_(x)sources.
基金Supported by the Incubation Project of Zhongshan Hospital(Xiamen),Fudan University,No.2019ZSXMYS15the Clinical Research Center for Precision Medicine of Abdominal Tumor of Fujian Province+1 种基金the Key Clinical Specialty Discipline Construction Program of Fujian ProvinceXiamen Medical and Health Guidance Project,No.3502Z20244ZD1103.
文摘BACKGROUND Improving the intraoperative and postoperative performance of laparoscopic hepatectomy was quite a challenge for liver surgeons.AIM To determine the benefits of indocyanine green(ICG)fluorescence imaging in patients with hepatocellular carcinoma(HCC)who underwent laparoscopic hepatectomy during and after surgery.METHODS We retrospectively collected the clinicopathological data of 107 patients who successfully underwent laparoscopic hepatectomy at Zhongshan Hospital(Xiamen),Fudan University from June 2022 to June 2023.Whether using the ICG fluorescence imaging technique,we divided them into the ICG and non-ICG groups.To eliminate statistical bias,a 1:1 propensity score matching analysis was conducted.The comparison of perioperative outcomes,including inflammationrelated markers and progression-free survival,was analyzed statistically.RESULTS Intraoperatively,the ICG group exhibited lower blood loss,a shorter surgical time,lower hepatic inflow occlusion(HIO)frequency,and a shorter total HIO time.Postoperatively,the participation of ICG resulted in a shorter duration of hospitalization(6.5 vs 7.6 days,P=0.03)and postoperative inflammatory response attenuation(lower neutrophil-lymphocyte ratio on the first day after surgery and platelet-lymphocyte ratio on the third day,P<0.05).Although the differences were not significant,the levels of all inflammation-related markers were lower in the ICG group.The rates of postoperative complications and the survival analyses,including progression-free and overall survivals showed no significant difference between the groups.CONCLUSION The involvement of ICG fluorescence imaging may lead to improved perioperative outcomes,especially postoperative inflammatory response attenuation,and ultimately improve HCC patients’recovery after surgery.
基金supported by the National Key Research and Development Program of China (2022YFD1800604)the China Agricultural Research System (CARS-41)the Heilongjiang Touyan Innovation Team Program of China
文摘Avian metapneumovirus(aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses. Subtype B aMPV has recently become the dominant epidemic strain in China. We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate. The safety test showed that after the 30th passage, the LN16-A strain was fully attenuated, as clinical signs of infection and histological lesions were absent after inoculation.The LN16-A strain did not revert to a virulent strain after five serial passages in chickens. The genomic sequence of LN16-A differed from that of the parent wild-type LN16(wtLN16) strain and had nine amino acid mutations. In chickens, a single immunization with LN16-A induced robust humoral and cellular immune responses, including the abundant production of neutralizing antibodies, CD4^(+) T lymphocytes, and the Th1(IFN-γ) and Th2(IL-4 and IL-6)cytokines. We also confirmed that LN16-A provided 100% protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation. Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.
基金supported by the National Natural Science Foundation of China(grant Nos.U21A20256).
文摘African swine fever(ASF)caused by the ASF virus(ASFV)is a highly contagious disease of pigs and wild boars.Currently,there are no safe,effective commercial vaccines available.The genome of ASFV HLJ/18 contains more than 180 genes,including a few virulence-related genes.Identifying these key virulence genes through individual deletion and subsequent pathogenicity testing in pigs is a laborious process.In addition,some ASFV genes are indispensable for viral replication and cannot be deleted.Over the past 30 years,scientists have confirmed that certain ASFV genes particularly those host antiviral innate immune responses,are associated with the virulence of ASFV strains.Although knockout of these genes does not impact viral replication,it does attenuate the virulence of ASFV in pigs.Pigs immunized with these live attenuated vaccine candidates can provide partial or complete protection.Based on these findings,we propose a new concept that ASFV immunomodulatory genes involved in type I interferon(IFN)production,IFN-JAK-STAT signaling,inflammatory responses,cell death(involved in apoptosis,necrosis,and pyroptosis),and autophagy may be related to the pathogenicity of ASFV.An unbiased screening may identify more ASFV immunomodulatory or multifunctional genes,simplifying the confirmation of ASFV virulence-related genes.In line with these theories,we have identified MGF505-7R and H240R as key virulence genes determining the pathogenicity of the ASFV HLJ/18 strain.Deletion of MGF505-7R,H240R alone or both attenuate the virulence of ASFV HLJ/18 in pigs,providing a paradigm for developing attenuated live vaccines from basic research results.
基金supported by the National Key Research and Development Program of China(No.2021YFE0103700)the National Natural Science Foundation of China(U21A20407,22274163,and 22374160)Shaanxi Fundamental Science Research Project for Chemistry and Biology(No.23JHQ054).
文摘Alzheimer’s disease(AD)is a complex neurodegenerative condition.5α-epoxyalantolactone(5α-EAL),a eudesmane-type sesquiterpene isolated from the herb of Inula macrophylla,has various pharmacological effects.This work supposed to investigate the improved impact of 5α-EAL on cognitive impairment.5α-EAL inhibited the generation of nitric oxide(NO)in BV-2 cells stimulated with lipopolysaccharide(LPS)with an EC50 of 6.2μM.5α-EAL significantly reduced the production of prostaglandin E2(PGE2)and tumor necrosis factor-α(TNF-α),while also inhibiting the production of cyclooxygenase-2(COX-2)and inducible nitric oxide synthase(iNOS)proteins.The ability of 5α-EAL to penetrate the blood-brain barrier(BBB)was confirmed via a parallel artificial membrane permeation assay.Scopolamine(SCOP)-induced AD mice model was employed to assess the improved impacts of 5α-EAL on cognitive impairment in vivo.After the mice were pretreated with 5α-EAL(10 and 30 mg/kg per day,i.p.)for 21 days,the behavioral experiments indicated that the administration of the 5α-EAL could alleviate the cognitive and memory impairments.5α-EAL significantly reduced the AChE activity in the brain of SCOP-induced AD mice.In summary,these findings highlight the beneficial effects of the natural product 5α-EAL as a potential bioactive compound for attenuating cognitive deficits in AD due to its pharmacological profile.
基金supported by the National Key Research and Development Program of China(2021YFC2302503)the National Natural Science Foundation of China(82241069)+1 种基金Cheng-Feng Qin was supported by the National Science Fund for Distinguished Young Scholars(81925025)the Innovative Research Group from the NSFC(81621005).
文摘Human Enterovirus 71(EV71)has emerged as one of the predominant causative agents of hand,foot and mouth disease(HFMD)with global impact.Despite the inactivated vaccine being licensed,other vaccine candidates based on advanced technology platforms are under development.In this report,we rationally designed and constructed two DNA-launched live attenuated vaccine candidates(pDL-EV71)under the control of specific promoters.In vitro and in vivo transfection with pDL-EV71 driven by the CMV promoter successfully yielded fully infectious EV71.More importantly,the administration of pDL-EV71 did not cause clinical symptoms following intracranial or intramuscular inoculation in neonatal and IFNα/βR/mice,demonstrating its safety profile.Moreover,a single-dose or two-dose immunization with pDL-EV71 elicited robust neutralizing antibodies against EV71 as well as an antigen-specific cellular response in mice.A single-dose immunization with 10μg of pDL-EV71 conferred complete protection against lethal EV71 infection in neonates born to immunized maternal mice.Overall,our present results demonstrate that pDL-EV71 is a safe and effective vaccine candidate against EV71 for further development.
基金funding from the National Key Research and Development Project of China(2021YFC2300202)the National Natural Science Foundation of China(82171820)+2 种基金C.-F.Q.received support from the National Science Fund for Distinguished Young Scholar(81925025)the Innovative Research Group(81621005)from the National Natural Science Foundation Chinathe Innovation Fund for Medical Sciences(No.2019-I2M-5-049)from the Chinese Academy of Medical Sciences.
文摘The live attenuated hepatitis A virus vaccine H2 strain was developed by passaging a wild-type H2w isolate in cell cultures.Currently,the mechanism underlying its attenuation phenotype remain largely unknown.In this study,we generated a full-length infectious cDNA clone of the H2 strain using in-fusion techniques.The recovered H2 strain(H2ic)from the cDNA clone exhibited an efficient replication in both the hepatoma cell line Huh7.5.1 and the 2BS cell line used for vaccine production,similar to the parental H2 strain.Additionally,H2ic did not cause disease in Ifnar1-/- C57 mice,consistent with the H2 strain.To explore the cell-adaptive mutations of the H2 strain,chimeric viruses were generated by replacing its non-structural proteins with corresponding regions from H2w using the infectious cDNA clone as a genetic backbone.The chimeric viruses carrying the 3C or 3D proteins from H2w showed decreased replication in Huh7.5.1 and 2BS cell lines compared to H2ic.Other chimeric viruses containing the 2B,2C,or 3A proteins from H2w failed to be recovered.Furthermore,there were no significant differences in disease manifestation in mice between H2ic and the recovered chimeric viruses.These results demonstrate that adaptive mutations in the 2B,2C,and 3A proteins are essential for efficient replication of the H2 strain in cell cultures.Mutations in the 3C and 3D proteins contribute to enhanced replication in cell cultures but did not influence the attenuated phenotypes in mice.Together,this study presents the first reverse genetic system of the H2 strain and identifies viral proteins essential for adaptation to cell cultures.
基金Supported by National High Technology Research and Development Program of China(2006AA10A206)National Natural Science Foundation of China(31001072)the Fund of Beijing Academy of Agriculture and Forestry Sciences for Young Scholars(QNJJ201012)~~
文摘[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.
文摘Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis(FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli(APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.
基金supported by the National Natural Science Foundation of China(61271398)Natural Science Foundation of Zhejiang Province(LY14A010004)K.C.Wong Magna Fund in Ningbo University
文摘In this article, we study reconstruction of nonuniform attenuated SPECT data and present analytic reconstruction formulae which are similar to Novikov＇s inversion formula. Furthermore, we extend Natterer＇s results.
基金supported by the National Institute of Dental and Craniofacial Research(NIDCR)the National Center for Research Resources(NCRR)of the National Institutes of Health(NIH)under award numbers R21DE023178,R01DE024796,and S10RR027553
文摘Hypoxia（low oxygen level） is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation of hypoxia-inducible factor 1（HIF-1）.Hypoxia interferes degradation of HIF-1 alpha subunit（HIF-1α）, leading to stabilisation of HIF-1α, heterodimerization with HIF-1 beta subunit（HIF-1β） and subsequent activation of HIF-1 pathway. Apical periodontitis（periapical lesion） is a consequence of endodontic infection and ultimately results in destruction of tooth-supporting tissue, including alveolar bone. Thus far, the role of HIF-1 in periapical lesions has not been systematically examined. In the present study, we determined the role of HIF-1 in a wellcharacterised mouse periapical lesion model using two HIF-1α-activating strategies, dimethyloxalylglycine（DMOG） and adenovirusinduced constitutively active HIF-1α（CA-HIF1 A）. Both DMOG and CA-HIF1 A attenuated periapical inflammation and tissue destruction. The attenuation in vivo was associated with downregulation of nuclear factor-κappa B（NF-κB） and osteoclastic gene expressions. These two agents also suppressed NF-κB activation and subsequent production of proinflammatory cytokines by macrophages. Furthermore, activation of HIF-1α by DMOG specifically suppressed lipopolysaccharide-stimulated macrophage differentiation into M1 cells, increasing the ratio of M2 macrophages against M1 cells. Taken together, our data indicated that activation of HIF-1 plays a protective role in the development of apical periodontitis via downregulation of NF-κB, proinflammatory cytokines, M1 macrophages and osteoclastogenesis.
基金supported by the National Natural Science Foundation of China,No.81374001,81673778,81273895the Foundation for Innovative Research Groups of the Natural Science Foundation of Hubei Province of China,No.2013CFA014
文摘Neuroinflammation is recognized as an important pathogenic factor for aging and related cognitive disorders. Mitogen-activated protein kinase and nuclear factor kappa B signaling pathways may mediate neuroinflammation. Saponins from Panax japonicus are the most abundant and bioactive members in rhizomes of Panaxjaponicus, and show anti-inflammatory activity. However, it is not known whether saponin from Panaxjaponicus has an anti-inflammatory effect in the aging brain, and likewise its underlying mechanisms. Sprague-Dawley rats were divided into control groups （3-, 9-, 15-, and 24-month-old groups） and saponins from Panaxjaponicus-treated groups. Saponins from Panaxjaponicus-treated groups were orally administrated saponins from Panaxjaponicus at three doses of 10, 30, and 60 mg/kg once daily for 6 months until the rats were 24 months old. Immunohistochemical staining and western blot assay results demonstrated that many microglia were activated in 24-month-old rats compared with 3- and 9-month-old rats. Expression of interleukin-1β, tumor necrosis factor-a, cyclooxygenase-2, and inducible nitric oxide synthase increased. Each dose of saponins from Panaxjaponicus visibly suppressed microglial activation in the aging rat brain, and inhibited expression levels of the above factors. Each dose of saponins from Panax japonicus markedly diminished levels of nuclear factor kappa B, IKBa, extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38. These results confirm that saponins from Panaxjaponicus can mitigate neuroinflammation in the aging rat brain by inhibition of the mito- gen-activated protein kinase and nuclear factor kappa B signaling pathways.
基金supported by grants from the National Key Research and Development Program(2018YFC0840402)National Natural Science Foundation of China(31941002)+2 种基金Special Fund for Basic Scientific Research of Chinese Academy of Agricultural Sciences (Y2019YJ07-01)Science and technology innovation engineering major scientific research program of Chinese Academy of Agricultural Sciences (CAASZDRW202006-03)State Key Laboratory of Veterinary Etiological Biology Major achievements cultivation project of Chinese Academy of Agricultural Sciences (SKLVEB2020CGPY02)。
文摘African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commercial vaccine is available because of the complexity of ASFV or biosecurity concerns.Live attenuated viruses that are naturally isolated or genetically manipulated have demonstrated reliable protection against homologous ASFV strain challenge.In the present study,a mutant ASFV strain with the deletion of ASFV MGF-110-9L(ASFV-D9L)was generated from a highly virulent ASFV CN/GS/2018 parental strain,a genotypeⅡASFV.Relative to the parental ASFV isolate,deletion of the MGF-110-9L gene significantly decreased the ability of ASFV-D9L to replicate in vitro in primary swine macrophage cell cultures.The majority of animals inoculated intramuscularly with a low dose of ASFV-D9L(10 HAD50)remained clinically normal during the 21-day observational period.Three of five ASFV-D9L-infected animals displayed low viremia titers and low virus shedding and developed a strong virus-specific antibody response,indicating partial attenuation of the ASFV-D9L strain in pigs.The findings imply the potential usefulness of the ASFV-D9L strain for further development of ASF control measures.
基金supported by the Natural Science Foundation of Jiangsu Province, China (BK2007711)the China Postdoctoral Fundation (20070421022)the Three Agricultural Projects Fundation of Jiangsu Province, China (SX2007082)
文摘To investigate the immune responses to the attenuated Mycoplasma hyopneumoniae 168 strain vaccine, 8-15 d old piglets were immunized with M. hyopneurnoniae 168 strain vaccine by intrapulmonic route. And the specific IgG antibody in serum, lymphoproliferation, IFNT, and specific secretory IgA （SIgA） antibody in bronchoalveolar lavage fluid were detected on 30 and 60 d post-immunization （DPI）, respectively. On 60 DPI, all the pigs except for those in health control group were challenged with a field M. hyopneumoniae strain JS. Necropsy was performed on 30 d post-challenge （DPC）. The results showed that IFN7 and specific SIgA were stimulated on surface of respiratory tract after immunization. And peripheral blood mononuclear cells could also be proliferated about 1.81 and 2.12 fold on 30 and 60 DPI when stimulated by M. hyopneumoniae protein in vitro. However, no serum IgG antibody against M. hyopneumoniae was detected during the whole immune phage. After challenge, vaccinated pigs were observed with only very slight histological lesion in individual lobes. None of vaccinated pigs showed any clinical signs. While the unvaccinated pigs from challenge control group showed varying degrees of clinical sign and severe macroscopical lesion of mycoplasmal pneumonia of swine （MPS）. The result suggested that the attenuated M. hyopneumoniae 168 strain vaccine inoculated by intrapulmonic route could activate the systemic cellular immunity, the local mucosal immunity and IFNγ secretion in respiratory tract to against M. hyopneumoniae infection in piglets.
基金This work was supported by Chinese Postdoctoral Fund (Grant No. 2004035426).
文摘Objective To prepare the live recombinant vaccine of attenuated Salmonella typhimurium SL3261 expressing Helicobacterpylori （H. pylori） B subunit （UreB） and to determine whether it could be used as an oral vaccine against H. pylori infection. Methods Using genomic DNA of H. pylori Sydney strain （SS1） as template, the H. pylori UreB gene fragment was amplified by PCR and subcloned into the expression vector pTC01. The recombinant plasmid pTC01-UreB was then transferred into LBS000 to obtain modified forms, and further conversed into the attenuated Salmonella typhimurium SL3261 to obtain recombinant SL3261/pCT01-UreB as an oral immunization reagent, which was then used to orally immunize Balb/c mice twice at a three-week interval. Twelve weeks later, anti-UreB IgA antibodies in intestinal fluid and IgG antibodies in sera were determined by ELISA. The relating data in control groups （including body weight, gastric inflammation, etc.） were also collected. Results The sequencing analysis showed that the UreB gene fragment amplified by PCR was consistent with the sequence of the H. pylori UreB gene. The restriction enzyme digestion revealed that the correct pTC01-UreB was obtained. SDS-PAGE and Western blot showed that a 61KD protein was expressed in SL3261/pTC01-UreB, which could be recognized by anti-H, pylori UreB antiserum and was absent in the control containing only Salmonella typhimurium SL3261 strain. The multiple oral immunization with SL3261/pTC01-UreB could significantly induce H. pylori specific mucosal IgA response as well as serum IgG responses. IFN-T and IL-10 levels were significantly increased in SL3261/pTC01-UreB group, and no obvious side effect and change in gastric inflammation were observed. Conclusion The attenuated vaccine of Salmonella typhimurium expressing H. pylori UreB can be used as an oral vaccine against H. pylori infection.
基金national ninth five-year study program for tackling key scientific problems,No.03-01-01
文摘AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.
基金supported by the National Natural Science Foundation of China(61271398)K.C.Wong Magna Fund in Ningbo University
文摘In this work, the image reconstruction in π-scheme short-scan single-photon emission computed tomography （SPECT） with nonuniform attenuation is derived in its most general form when π-scheme short-scan SPECT entails data acquisition over disjoint angular intervals without conjugate views totaling to π radians. The reconstruction results are based on decomposition of Novikov＇s inversion operator into three parts bounded in the L2 sense. The first part involves the measured partial data; the second part is a skew-symmetric operator; the third part is a symmetric and compact contribution. It is showed firstly that the operators involved belong to L（L^2（B）. Furthermore numerical simulations are conducted to demonstrate the effectiveness of the developed method.
文摘Objective:To develop allenualed slrains of Salmonella enterica serorar Typhi(S.typhi) for the candidate vaccine by osmolar stress.Mothods:S.typhi SS3 and SS5 strains were isolated from asymptomatic typhoid carriers in Mamakkal,Tamil Nadu.India.Both strains were grown in LB(Luria Bertani) medium supplemented with various concentration of NaCl(0.1- 0.7M) respectively.The effecl of osmolar stress was determined at molecular level by PCR using MCR 06 and MCR07 primers corresponding to ompR with chromosomal DNA of S.typhi SS3 and SS5 strains.Attenuation by osmolar stress results in deletion mutation of the.S.typhi slrains was determined by agglutination assays,precipitation method.SDS PAGE analysis and by animal models.Results:The 799 bp amplified ompR gene product from wild type S.typhi SS3 and SS5 illustrate the presence of virulent gene.Interestingly,there was only a 282 bp amplified product from S.typhi SS3 and SS5 grown in the presence of 0.5.0.6 and 0.7 M NaCl.This illustrates the occurrence of deletion mutation in ompR gene al high concentration of NaCl.Furthermore,both the wildtype and mutant S.typhi outer membrane SDS-PAGF.profile reveals the differences in the expression of ompF.ompC and ompA proteins.In mice,wild type and mutant strains lethal dose(LD_(50)) were determined.The mice died within 72 h when both the wild type strains were injected intraperitoneally with 3 log CFU-mL^(-1).When the mice were injected with the mutants in same dosage,no clinical symptoms were observed;whereas the serum antibodv litre was elicited within two weeks indicated that the mutants have the ability to induce protective humoral immune response.These results suggest that S.typhi SS3 and SS5 may bo used as good candidate strains for the development of live attenuated vaccine against salmonellosis.Conclusions:This study demonstrates that the S.typhi strains were allenualed and could be good vaccine candidates in future.
基金was supported by the National Key R&D Program of China(2017YFD0500203)the National Natural Science Foundation of China(31672574)+3 种基金the Special Fund for Agro-scientific Research in the Public Interest,China(201403054)the Primary Research&Development Plan of Jiangsu Province,China(BE2017341)the Jiangsu Agricultural Science and Technology Innovation Fund [CX(16)1028]the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)
文摘Streptococcus equi ssp. zooepidemicus(SEZ) is a pathogen associated with a wild range of animal species. Frequent outbreaks have occurred in recent years in pigs, horses, goats and dogs which is liable to infect humans. There is a lack of efficient vaccines against this disease and the occurrence of antibiotic resistance may render drug therapies ineffective. In this study, gene deletion mutant(ΔSEZ) in pathogenicity islands SeseCisland_4 was constructed. The mutant ΔSEZ had a 52-fold decrease in 50% lethal dose(LD_(50)) and had less capacity to adhere epithelial cells. Importantly, immunization of mice with attenuated vaccine ΔSEZ at the dose of 10~2 colony-forming units(CFU) mL^(–1) elicited a significant humoral antibody response, with an antibody titer of 1:12 800. Therefore, 10~2 CFU mL^(–1) might be used as the appropriate immune dose for the attenuated vaccine ΔSEZ, which provided mice with efficient protection against virulent SEZ. In addition, the hyperimmune sera against 10~2 CFU m L–1 attenuated vaccine ΔSEZ could confer significant protection against virulent SEZ infection in the passive immunization experiment and exhibited efficient bactericidal activity in the whole blood assay. Meanwhile, no viable bacteria was detected in blood when mice were immunized with ΔSEZ at the dose of 10~2 CFU mL^(–1) via hypodermic injection. Thereafter, the mutant ΔSEZ at the dose of 10~2 CFU mL^(–1) could confer significant protection in mice and had less negative effects on host, which could be an effective attenuated vaccine candidate for the prevention of SEZ.
基金This work was supported by grants from the Natural Science Foundation of China(81771777,32070922).
文摘Human respiratory syncytial virus(RSV)infection is the leading cause of lower respiratory tract illness(LRTI),and no vaccine against LRTI has proven to be safe and effective in infants.Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice.The constructed recombinant plasmids harbored(5′to 3′)a T7 promoter,hammerhead ribozyme,RSV Long strain antigenomic cDNA with cold-passaged(cp)mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain(A2cpts)or further combined with SH gene deletion(A2cptsΔSH),HDV ribozyme(δ),and a T7 terminator.These vectors were subsequently co-transfected with four helper plasmids encoding N,P,L,and M2-1 viral proteins into BHK/T7-9 cells,and the recovered viruses were then passaged in Vero cells.The rescued recombinant RSVs(rRSVs)were named rRSV-Long/A2cp,rRSV-Long/A2cpts,and rRSV-Long/A2cptsΔSH,respectively,and stably passaged in vitro,without reversion to wild type(wt)at sites containing introduced mutations or deletion.Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed temperature-sensitive(ts)phenotype in vitro and in vivo,all rRSVs were significantly attenuated in vivo.Furthermore,BALB/c mice immunized with rRSVs produced Th1-biased immune response,resisted wtRSV infection,and were free from enhanced respiratory disease.We showed that the combination ofΔSH with attenuation(att)mutations of cpts contributed to improving att phenotype,efficacy,and gene stability of rRSV.By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains,we have laid an important foundation for the development of RSV live attenuated vaccines.
