Associations of Serum Antimicrobial Peptide LL-37 with Longitudinal Cognitive Decline and Neurodegeneration Among Older Adults with Memory Complaints.

BACKGROUND: A potential role of the antimicrobial peptide LL-37, which is upregulated after infection, in the pathogenesis of Alzheimer's disease (AD) was identified. However, the clinical relevance of LL-37 in AD is not clear yet. OBJECTIVE: This study aims to investigate the association of circulating LL-37 with longitudinal cognitive decline and neurodegeneration among older adults with memory complaints. METHODS: This cohort study recruited 357 older adults with memory complaints. Participants were followed-up for two years and the cognitive functions were assessed using the Mini-Mental State Examination (MMSE). Serum LL-37, pTau181, and tTau levels were determined at baseline. Associations of baseline LL-37 with longitudinal cognitive decline and change of neurodegenerative biomarkers were analyzed. RESULTS: No difference was found in the slope of longitudinal cognitive decline during follow-up between the low and high LL-37 group, adjusting for age, sex, education, body mass index, APOE ɛ4 carrier status, comorbidities, and baseline MMSE scores (difference in slope: 0.226, 95% CI: -0.169 to 0.621). Higher LL-37 levels were associated with longitudinal cognitive decline, as indicated by a decrease of MMSE scores of 3 points or above during follow-up (OR = 2.11, 95% CI: 1.32 to 3.38). The high LL-37 group had larger slopes of the increase in neurofilament light (difference in slope: 3.759, 95% CI: 2.367 to 5.152) and pTau181 (difference in slope: 0.325, 95% CI: 0.151 to 0.499) than the low LL-37 group. CONCLUSION: These findings support an association of the antimicrobial peptide LL-37 with AD from a clinical perspective.

Leukoencephalopathy in children with acute lymphoblastic leukemia after chemotherapy: a retrospective monocenter study.

Background: To investigate the clinical and neuroimaging characteristics of leukoencephalopathy among children with acute lymphoblastic leukemia (ALL), especially after chemotherapy. Methods: Clinical data for 17 pediatric patients with leukoencephalopathy and 17 matched controls were retrospectively analyzed. All participants were children with ALL admitted to the Children's Hospital of Soochow University from May 2011 to April 2021. The data mainly consisted of general information, laboratory studies, and imaging diagnostic results. Results: Overall, 94.12% of the patients experienced neurological symptoms. The most common symptoms were seizure (7/17, 41.18%), nausea (5/17, 29.41%), vomiting (5/17, 29.41%), paralysis (5/17, 29.41%), and numbness (4/17, 23.53%). On neuroimaging, multiple and irregular lesions were observed, distributed mainly in the periventricular area (9/17, 52.94%), parietal lobe (6/17, 35.29%), and basal ganglia (5/17, 29.41%). Moreover, there were significant differences in serum sodium (P=0.0001), C-reactive protein (P=0.0124) and blood pressure (P=0.0271) between patients with and without leukoencephalopathy. After aggressive treatment, the clinical symptoms (12/17, 70.59%) and imaging lesions (11/13, 84.62%) gradually improved in most patients. Conclusions: Chemotherapy is an important risk factor related to leukoencephalopathy. Although the clinical symptoms of leukoencephalopathy vary widely, there is a high degree of consistency in its radiological features. Abnormal laboratory results may also help the identification of leukoencephalopathy. Early detection and treatment can improve brain development in the long term.

Safety and clinical efficacy of linezolid in children: a systematic review and meta-analysis.

BACKGROUND: We aimed to evaluate the tolerability and efficacy of linezolid in children for treating suspected and diagnosed Gram-positive bacterial infections. METHODS: A systematic literature search was conducted up to April 23, 2021, using linezolid and its synonyms as search terms. Two reviewers independently identified and extracted relevant randomized controlled trials and prospective cohort studies. The extracted studies were included in a single-rate meta-analysis of adverse events and clinical outcomes using random-effects models. RESULTS: A total of 1082 articles were identified, and nine studies involving 758 children were included in the meta-analysis. The overall proportion of adverse events was 8.91% [95% confidence interval (CI) = 1.64%-36.52%], with diarrhea (2.24%), vomiting (2.05%), and rash (1.72%) being the most common. The incidences of thrombocytopenia and anemia were 0.68% and 0.16%, respectively. Some specific adverse events, including rash and gastrointestinal events, were more frequent in the oral administration subgroup. In terms of efficacy, the overall proportion of clinical improvement was 88.80% (95% CI = 81.31%-93.52%). Children with a history of specific bacteriological diagnosis or concomitant antibiotic therapy had a 1.13-fold higher clinical improvement than children without such histories. The proportion of microbial eradication was 92.68% (95% CI = 84.66%-96.68%). The proportion of all-cause mortality was 0.16% (95% CI = 0.00%-7.75%). CONCLUSIONS: Linezolid was well-tolerated in pediatric patients and was associated with a low frequency of adverse events, such as anemia, thrombocytopenia, and neutropenia. Moreover, linezolid was effective in children with diagnosed and suspected Gram-positive infections.

Acute Hepatitis of Unknown Origin in Children: Early Observations from the 2022 Outbreak.

Recent reports of acute hepatitis of unknown origin in previously healthy children have been increasing worldwide. The main characteristics of the affected children were jaundice and gastrointestinal symptoms. Their serum aminotransaminase levels were above 500 IU/L, with negative tests for hepatitis viruses A-E. By 31 May 2022, the outbreak had affected over 800 children under the age of 16 years in more than 40 countries, resulting in acute liver failure in approximately 10%, including at least 21 deaths and 38 patients requiring liver transplantation. There was still no confirmed cause or causes, although there were several different working hypotheses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), adenovirus serotype 41, or SARS-CoV-2 superantigen-mediated immune cell activation. Here, we review early observations of the 2022 outbreak which may inform diagnosis, treatment, and prevention in the context of an overlapping COVID-19 pandemic.

MiR-27a promotes EMT in ovarian cancer through active Wnt/𝜷-catenin signalling by targeting FOXO1.

BACKGROUND: Ovarian cancer (OC) is the fifth most common type of cancer in women worldwide. MiR-27a plays an important role in the development of ovarian cancer. However, the exact function and molecular mechanism of miR-27a in epithelial-mesenchymal transition (EMT) has not been thoroughly elucidated to date. METHODS: Quantitative real-time PCR (qRT-PCR) was used to determine the expression of miR-27a and FOXO1 mRNA in ovarian tissues and cells. The function of miR-27a in ovarian cancer was investigated through overexpression and knockdown of miR-27a in vitro. Wound healing and Transwell assays were performed to evaluate the migration and invasive capacity of the cells. A luciferase reporter assay was conducted to confirm the interaction between miR-27a and FOXO1. Western blotting was used to evaluate FOXO1, EMT and Wnt/ß-catenin relative protein expression. RESULTS: In our study, we found that the mRNA expression level of miR-27a was significantly higher in ovarian cancer tissues and in HO8910 and OV90 cells. Functional experiments showed that miR-27a overexpression potentiated the migration and invasion of HO8910 and OV90 cells, while miR-27a inhibition reduced the cells' migration and invasion. Moreover, miR-27a upregulated the expression of mesenchymal cell markers and downregulated the expression of epithelial cell markers, which were restored via silencing of miR-27a expression. Subsequently, miR-27a was found to directly target and suppress the expression of FOXO1. Finally, we demonstrated that miR-27a promoted the progression of ovarian cancer cells and induced the process of EMT via the Wnt/ß-catenin signalling pathway through inhibition of FOXO1. CONCLUSIONS: Taken together, these results indicate that targeting miR-27a and FOXO1 could represent a strategy for anticancer therapy in ovarian cancer.

Effects of an EPSPS-transgenic soybean line ZUTS31 on root-associated bacterial communities during field growth.

The increased worldwide commercial cultivation of transgenic crops during the past 20 years is accompanied with potential effects on the soil microbial communities, because many rhizosphere and endosphere bacteria play important roles in promoting plant health and growth. Previous studies reported that transgenic plants exert differential effects on soil microbial communities, especially rhizobacteria. Thus, this study compared the soybean root-associated bacterial communities between a 5-enolpyruvylshikimate-3-phosphate synthase -transgenic soybean line (ZUTS31 or simply Z31) and its recipient cultivar (Huachun3 or simply HC3) at the vegetative, flowering, and seed-filling stages. High-throughput sequencing of 16S rRNA gene (16S rDNA) V4 hypervariable region amplicons via Illumina MiSeq and real-time quantitative PCR (qPCR) were performed. Our results revealed no significant differences in the overall alpha diversity of root-associated bacterial communities at the three developmental stages and in the beta diversity of root-associated bacterial communities at the flowering stage between Z31 and HC3 under field growth. However, significant differences in the beta diversity of rhizosphere bacterial communities were found at the vegetative and seed-filling stages between the two groups. Furthermore, the results of next generation sequencing and qPCR showed that the relative abundances of root-associated main nitrogen-fixing bacterial genera, especially Bradyrhizobium in the roots, evidently changed from the flowering stage to the seed-filling stage. In conclusion, Z31 exerts transitory effects on the taxonomic diversity of rhizosphere bacterial communities at the vegetative and seed-filling stages compared to the control under field conditions. In addition, soybean developmental change evidently influences the main symbiotic nitrogen-fixing bacterial genera in the roots from the flowering stage to the seed-filling stage.

[Risk factors for 5-year recurrence of spontaneous symptomatic epileptic seizures in infants and young children].

OBJECTIVE: To investigate the recurrence rate and risk factors of spontaneous symptomatic epileptic seizures after the first episode in infants and young children. METHODS: The clinical data of infants and young children who experienced the first episode of spontaneous symptomatic epileptic seizures between April 2009 and April 2011 in Suzhou Children's Hospital were collected. Follow-up visits were performed once every 1-3 months, and the follow-up time was 1-60 months. The Kaplan-Meier method and Cox proportional hazards model were applied to calculate the recurrence rate of spontaneous symptomatic epileptic seizures and analyze the risk factors for seizure recurrence. RESULTS: Sixty-three children experiencing a first episode of spontaneous symptomatic epileptic seizures were enrolled. Within 5 years after the first episode, 43 children experienced the recurrence of spontaneous symptomatic epileptic seizures, with a 5-year cumulative recurrence rate of 69.4%. Among all recurrent cases, 86% experienced recurrence within 1 year after the first episode. The multivariate analysis with the Cox proportional hazards model showed that epileptiform discharges on electroencephalography were the independent risk factor for recurrence of spontaneous symptomatic epileptic seizures (HR=5.349, 95%CI: 2.375-12.048). CONCLUSIONS: The recurrence rate of spontaneous symptomatic epileptic seizures after the first episode is high in infants and young children. Epileptiform discharges on electroencephalography are the independent risk factor for the recurrence, and thus it is suggested to perform antiepileptic therapy for these children.

Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy.

Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.

[Diagnostic values of neopterin and S100b for central nervous system infections in children].

OBJECTIVE: To study the diagnostic values of cerebrospinal concentrations of neopterin (NPT) and S100b for central nervous system infections in children. METHODS: Enzyme-linked immunosorbent assay was used to determinate the cerebrospinal concentrations of NPT and S100b in children with central nervous system infections and control children. The two groups of children were compared in terms of the two indicators, and the diagnostic values of the two indicators were evaluated by ROC curve analysis. RESULTS: Children with viral encephalitis had significantly increased cerebrospinal concentrations of NPT and S100b compared with the control group and children with purulent meningitis (P<0.01); there was no difference in the cerebrospinal concentration of NPT between children with purulent meningitis and the control group, while the concentration of S100b in the purulent meningitis group was significantly higher than in the control group (P<0.01). According to the ROC curves, S100b was more valuable than NPT in the diagnosis of viral encephalitis; when cerebrospinal concentration was more than 0.384 ng/mL, S100b had a sensitivity of 93.3% and a specificity of 97.9%; a combination of the two indicators had a higher diagnostic value for viral encephalitis, with a sensitivity of 96.7% and a specificity of 97.9%. CONCLUSIONS: Both NPT and S100b have certain values in the diagnosis of central nervous system infections in children, and S100b is better than NPT.

Bradyrhizobium arachidis sp. nov., isolated from effective nodules of Arachis hypogaea grown in China.

Twenty-three bacterial strains isolated from root nodules of Arachis hypogaea and Lablab purpureus grown in five provinces of China were classified as a novel group within the genus Bradyrhizobium by analyses of PCR-based RFLP of the 16S rRNA gene and 16S-23S IGS. To determine their taxonomic position, four representative strains were further characterized. The comparative sequence analyses of 16S rRNA and six housekeeping genes clustered the four strains into a distinctive group closely related to the defined species Bradyrhizobium liaoningense, Bradyrhizobium yuanmingense, Bradyrhizobium huanghuaihaiense, Bradyrhizobium japonicum and Bradyrhizobium daqingense. The DNA-DNA relatedness between the reference strain of the novel group, CCBAU 051107(T), and the corresponding type strains of the five mentioned species varied between 46.05% and 13.64%. The nodC and nifH genes of CCBAU 051107(T) were phylogenetically divergent from those of the reference strains for the related species. The four representative strains could nodulate with A. hypogaea and L. purpureus. In addition, some phenotypic features differentiated the novel group from the related species. Based on all the results, we propose a new species Bradyrhizobium arachidis sp. nov. and designate CCBAU 051107(T) (=CGMCC 1.12100(T)=HAMBI 3281(T)=LMG 26795(T)) as the type strain, which was isolated from a root nodule of A. hypogaea and had a DNA G+C mol% of 60.1 (Tm).

[Sperm DNA damage and sperm-nucleoprotein transition correlate to acrosin activity and seminal parameters].

OBJECTIVE: To investigate the correlation of sperm DNA damage and sperm-nucleoprotein transition with acrosin activity and seminal parameters. METHODS: We collected 535 semen samples, assessed sperm DNA damage by sperm chromatin dispersion test, and analyzed the correlation of sperm DNA damage and sperm-nucleoprotein transition with acrosin activity and seminal parameters according to the WHO criteria. RESULTS: Statistically significant differences were observed in sperm DNA damage among sperm-nucleoprotein transition, acrosin activity, sperm concentration and the percentage of grade a + b sperm (P < 0.01). Sperm DNA damage was positively correlated with age, sperm-nucleoprotein transition, sperm concentration and the percentage of grade d sperm (P < 0.01 or P < 0.05), but negatively correlated with acrosin activity (P < 0.001). Stepwise linear regression analysis demonstrated that age, sperm concentration, the percentage of grade d sperm, sperm-nucleoprotein transition and acrosin activity were independent variables related to the DNA fragmentation index (DFI). The abnormality rates of sperm-nucleoprotein transition, acrosin activity, sperm concentration and graded a + b sperm were significantly higher in the sperm DNA damage group (DFI > or = 30%) than in the normal control (DFI < 30%) (P < 0.01). CONCLUSION: Sperm DNA damage is closely related with sperm-nucleoprotein transition, acrosin activity and seminal parameters, which may become another important independent parameter for the evaluation of sperm quality.

[Antitumor effect of natural killer cells in vitro by blocking transforming growth factor-ß signaling].

OBJECTIVE: To investigate the antitumor effect of natural killer (NK) cells on human colorectal cancer cells HT-29 in vitro by blocking transforming growth factor-ß (TGF-ß) signaling in NK cells transfected with vector containing dominant negative TGF-ß type 2 receptor (DNTßR2). METHODS: TGF-ß1 was added at the final concentration of 10 ng/ml for HT-29 cells. Primary NK cells were transfected with recombinant plasmid pIRES2-AcGFP-DNTßR2 and control plasmid pIRES2-AcGFP using Amaxa Nucleofector technology respectively. The cytotoxicity of these two types of NK cells to HT-29 cells was detected and analyzed by cell counting kit-8. RESULTS: The transfection efficiency of primary NK cells was 18.85% for the plasmid pIRES2-AcGFP-DNTßR2 and 35.28% for the control plasmid pIRES2-AcGFP. The expression of DNTßR2 in NK cells was confirmed by Western blotting and RT-PCR. Primary NK cells displayed significantly lower cytotoxicity against HT-29 cells incubated with TGF-ß1 than that without TGF-ß1 (effect-target cell ratio 10:1,14.40%∓ 2.00% vs. 26.14% ∓ 2.50%, P > 0.05; effect-target cell ratio 20:1, 19.18% ∓ 2.49% vs. 40.81% ∓ 3.50%, P > 0.05). The cytotoxicity of NK cells transfected with DNTßR2 vector was significantly higher than that with control vector against HT-29 cells cultured with 10 ng/ml TGF-ß1 (effect-target cell ratio 10:1, 21.17% ∓ 2.49% vs. 11.48% ∓ 1.11% ,P > 0.05; and effect-target cell ratio 20:1, 35.30% ∓ 3.78% vs. 17.19% ∓ 2.29%, P > 0.05). CONCLUSION: NK cells transfected with DNTßR2 vector show better antitumor effect, which may provide new method for NK-based adoptive immunotherapy for cancer.

(E)-2-Hydr-oxy-3-methoxy-benzaldehyde thio-semicarbazone.

In the title compound, C(9)H(11)N(3)O(2)S, intra-molecular O-H⋯O and N-H⋯N hydrogen bonds contribute to the planarity of the mol-ecular skeleton. Inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains along the b axis; these mol-ecules are futher paired by π-π inter-actions [centroid-centroid distance 4.495 (5) Å]. The crystal structure also exhibits weak inter-molecular N-H⋯S and O-H⋯S hydrogen bonds.

[Study on the pathogens correlated to sexually transmitted diseases in 285 pre-pubertal girls with vulvovaginitis in Beijing].

OBJECTIVE: To study the relationship between vulvovaginitis in pre-pubertal girls and pathogens as Chlamydia trachomatis (Ct), N. gonorrhoeae (Ng), Mycoplasma, Ureaplasma urealyticum (Uu), Mycoplasma hominis (Mh), M. genitalium (Mg), M. fermentans (Mf) and M. penetrans (Mpe), as well as to find out the proportion of mycoplasma which is correlated to sexually transmitted diseases (STD) and AIDS. METHODS Vulvae swab specimens from 285 pre-pubertal girls with vulvovaginitis (case group) and 128 healthy girls (control group) were collected and detected by nested polymerase chain reaction (nPCR) to identify the existence of pathogens as Ct, Ng, Uu, Mh, Mg, Mf and Mpe. nPCR with both high specificity and sensitivity, would not be influenced by the amount of pathogens in specimens or inactivated during the process of storage or transportation. RESULTS: The rate of detection on pathogens was 59.65% in the 285 specimens from case group including 'one kind of pathogen in one specimen' as 37.54% and 'two kinds' as 16.84% and 'three kinds' as 5.26%. However, in the 128 specimens from control group, the detectable rate of pathogen was 6.25%. Relationships were found between Ng (P < 0.01), Ct (P < 0.01), Uu (P < 0.01), Mg (P < 0.01), Mf (P < 0.05), Mpe (P < 0.01) and vulvovaginitis in pre-pubertal girls. In control group the pathogens were detected from 7 specimens including 5 Uu and 2 Mh. CONCLUSION: Some of the pathogens were correlated to STD and were important in causing vulvovaginitis in pre-pubertal girls. Vulvovaginitis might have been caused by more than one kind of pathogen in pre-pubertal girls. The locations of Mg, Mf and Ng in outer genital tracts were correlated to seasonal change. Macrolide seemed to be quite effective clinically in treating urogenital tract infection caused by mycoplasma and Ct.

[Meiotic segregation results of male reciprocal chromosome translocations].

OBJECTIVE: To analyze the meiotic segregation results of male reciprocal chromosome translocation by fluorescence in situ hybridization (FISH). METHODS: Multi-color FISH using 3 combined probes located in any 3 chromosome segments on both sides of two breakpoints was performed on the de-condensed sperm head to analyze the sperm chromosomal contents and segregation patterns. RESULTS: Four male reciprocal translocation carriers were included in the study, with the karyotypes of 46, XY, t(2;18) (p16; q23); 46, XY, t(4;6) (q34;q21); 46, XY, t(8;13) (q23;q21) and 46, XY, t(4;5) (4q31;5q13), respectively. The results showed that 4 carriers had different proportions of various segregated spermatozoa. The spermatozoa of alternate, adjacent-1, adjacent-2, 3:1, non-disjunction in meiosis II, and 4:0 or diploidy accounted for 27.1%-49.4%, 26.9%-37.6%, 2.7%-15.7%, 8.6%-32.7%, 0.2%-1.9%, and 0.1%-0.4%, respectively. CONCLUSION: For each-reciprocal translocation carrier seems to have a particular meiotic segregation results, FISH analysis on sperm head should be done for each carrier in order to provide an accurate genetic counseling.

[Cloning, purification, and antigenic characterization of three recombinant fragments derived from SARS-CoV S1 domain].

OBJECTIVE: The present study aimed to clone and express three fragments of genomic RNA derived from SARS associated coronavirus (SARS-CoV) S1 domain and to study its immunogenicity. METHODS: The S1 domain gene was amplified by PCR with specific primers and was inserted into the prokaryotic expression vector pQE-30. Three fragments (40-751, 746-1344 and 746-2001 bp) derived from S1 domain produced after the recombinant plasmid (pQE-30/S1) was digested by restriction endonucleases. The three fragments were cloned into pQE-30 and expressed in M15 strains of Escherichia coli. The expression products, designated S1a, S1b and S1c respectively, were purified by Ni affinity chromatography. The immunogenicity was analyzed by Western Blot and ELISA using serologically confirmed sera from SARS patients and the sera from healthy donors was used as control at the same assay. RESULTS: Three recombinant plasmids (pQE-30/S1a, pQE-30/S1b, pQE-30/S1c) were constructed.Fusion proteins with relative molecular mass of 26,700, 22,500 and 46,000 dalton were successfully expressed with amounts of 35%, 35% and 30% of total cell protein and purified by Ni affinity chromatography, respectively. Western Blot and ELISA analysis showed that the S1c protein could be specifically recognized by the sera from SARS patients. CONCLUSION: The recombinant S1c protein was a good immunogen and has the potential to be used as a vaccine against SARS-CoV infection.

Sensitive and specific monoclonal antibody-based capture enzyme immunoassay for detection of nucleocapsid antigen in sera from patients with severe acute respiratory syndrome.

A rapid antigen test for the diagnosis of severe acute respiratory syndrome (SARS) is essential for control of this disease at the point of management. The nucleocapsid (N) protein of SARS-associated coronavirus (SARS-CoV) is abundantly expressed in infected-cell culture filtrate as demonstrable by Western blotting using convalescent-phase sera from patients with SARS. We used monoclonal antibodies specifically directed against N protein to establish a sensitive antigen capture sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-CoV. The assay employed a mixture of three monoclonal antibodies for capture and rabbit polyclonal antibodies for detection of serum antigen in 32 cases of clinically probable SARS as defined by the World Health Organization during the epidemic in Guangzhou, China. Recombinant N protein was used as a standard to establish a detection sensitivity of approximated 50 pg/ml. The linear range of detection in clinical specimens was from 100 pg/ml to 3.2 ng/ml. Using a panel of sera collected at different points in time, the amount of circulating N antigen was found to peak 6 to 10 days after the onset of symptoms. The sensitivity of the assay was 84.6% in 13 serologically confirmed SARS patients with blood taken during the first 10 days after the onset of symptoms (11 of 13). The specificity of the assay was 98.5% in 1,272 healthy individuals (1,253 of 1,272). There was no cross-reaction with other human and animal coronaviruses in this assay. In conclusion, a sensitive and quantitative antigen capture ELISA was established for the early diagnosis and disease monitoring of SARS-CoV infection.

Rapid and efficient preparation of monoclonal antibodies against SARS-associated coronavirus nucleocapsid protein by immunizing mice.

OBJECTIVE: To develop a rapid and efficient method for preparing monoclonal antibodies (mAb) against SARS-associated coronavirus (SARS-Cov) nucleocapsid (N) protein. METHODS: BALB/c mice were injected with the recombinant N protein of SARS-Cov into the foot-pads for the immunization, and the popliteal lymph nodes were isolated 15 d later for mAb-producing hybridomas, from which the mAbs against the N protein of SARS-Cov were screened. The identification of the mAb against the N protein of SARS-Cov was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect fluorescent-antibody assay (IFA), and Western immunoblotting. RESULTS: Four strains of hybridomas were obtained that produced the mAb specific to the N protein without detectable cross-reactivity with other pathogens. Of the 4 strains, 2 were identified as the immunoglobulin G1 (IgG1) isotype, 1 IgG2a, and the other IgG2b, with affinity constants (Ka) of 2 of the strains being 4.14 x 10(-9)M and 3.19 x 10(-9)M respectively. CONCLUSION: This is the first report on the preparation of mAb that is specific to the SARS-Cov, and the high-specificity and high-affinity mAb produced by the 4 strains of hybridomas provide a basis for further researches on the pathogenesis and early diagnosis of SARS.