Biomedical subjects

Fang Wang

Publications and source records attributed to Fang Wang.

At least 91 records · Page 5Linked to original sources

PubMed2006

Human herpesvirus-6-specific interleukin 10-producing CD4+ T cells suppress the CD4+ T-cell response in infected individuals.

Human herpesvirus-6 (HHV-6) infection normally persists for the lifetime of the host and may reactivate with immunosuppression. The mechanism behind HHV-6 latent infection is still not fully understood. In this study, we observed that decreased proliferation of CD4+ T cells and PBMCs but not CD8+ T cells from HHV-6-infected individuals was stimulated with HHV-6-infected cell lysates. Moreover, HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals have suppressive activity on naïve CD4+ T and CD8+ T cells from HHV-6-uninfected individuals. However, no increased proportion of CD4+ CD25+ Treg cells from HHV-6-infected individuals contributed to the suppressive activity of the HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals. Transwell experiments, ELISA and anti-IL-10 antibody blocking experiment demonstrated that IL-10 may be the suppressive cytokine required for suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interleukin (IL)-10 and IL-4 further implicated the HHV-6-specific IL-10-producing CD4+ T cells in the suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interferon (IFN)-gamma demonstrated a decreased frequency of HHV-6-specific IFN-gamma-producing CD4+ T, but not CD8+ T cells in HHV-6-infected individuals, indicating that it was the CD4+ Th1 responses in HHV-6-infected individuals that were selectively impaired. Our findings indicated that HHV-6-specific IL-10-producing CD4+ T cells from HHV-6-infected individuals possess T regulatory type 1 cell activity: immunosuppression, high levels of IL-10 production, with a few cells expressing IFN-gamma, but none expressing IL-4. These cells may play an important role in latent HHV-6 infection.

Adult↗

PubMed2006

Cytokinin represses phosphate-starvation response through increasing of intracellular phosphate level.

The involvement of cytokinins (CTKs) in the repression of phosphate (Pi)-starvation signalling has been widely documented. However, the full physiological and molecular relevance of this role remains unclear. To gain further insights into the regulation system of CTK repression of Pi-starvation signalling, a global analysis of gene expression events in rice seedlings under Pi starvation, and the exogenous CTK treatment under Pi-sufficient (+P) and Pi-deficient (-P) conditions, was conducted using oligonucleotide array analysis. Physiological and biochemical adaptation was observed after 10 d Pi starvation in rice seedlings. A global reduction of the Pi-starvation signalling was detected after 3 d treatment of exogenous CTK. Expression profiling data indicate that, together with a significant increase of intracellular Pi content, many expression changes responsive to Pi starvation were reversed by exogenous CTK treatment while CTK-responsive genes behaved normally under -P condition. These results suggest that the interplay of CTK signal and Pi-starvation response can be partially explained by the rise of Pi concentration after exogenous CTK treatment. Microarray data also revealed that a small number of genes have different CTK response patterns under different Pi levels, suggesting a subtle interaction between CTK and Pi-starvation signalling pathway.

Cytokinins↗

PubMed2006

Aquaporins as potential drug targets.

The aquaporins (AQP) are a family of integral membrane proteins that selectively transport water and, in some cases, small neutral solutes such as glycerol and urea. Thirteen mammalian AQP have been molecularly identified and localized to various epithelial, endothelial and other tissues. Phenotype studies of transgenic mouse models of AQP knockout, mutation, and in some cases humans with AQP mutations have demonstrated essential roles for AQP in mammalian physiology and pathophysiology, including urinary concentrating function, exocrine glandular fluid secretion, brain edema formation, regulation of intracranial and intraocular pressure, skin hydration, fat metabolism, tumor angiogenesis and cell migration. These studies suggest that AQP may be potential drug targets for not only new diuretic reagents for various forms of pathological water retention, but also targets for novel therapy of brain edema, inflammatory disease, glaucoma, obesity, and cancer. However, potent AQP modulators for in vivo application remain to be discovered.

Animals↗

PubMed2006

Selection of novel nickel-binding peptides from flagella displayed secondary peptide library.

Nickel (Ni) performs its biological or toxic functions in nickel-protein coordination form. Novel Ni-binding peptides were isolated from a random dodecapeptide library displayed on the flagella of Escherichia coli against immobilized ions. On the basis of isolated sequences rich in histidine residues, two secondary libraries were constructed respectively. By consequent selection, more Ni-chelating peptides were identified and the consensus motif RHXHR (where X was always H) was deduced. The result suggested that not only histidine, but also arginine, play an important role in Ni-binding. Furthermore, two selected clones (1035 and 2022) were chosen for further identification. They exhibited similar relative binding affinity, which was about nine times that of the original library derived clones and statistically much more significant than the positive control with polyhistidine insert. Free nickel ions could almost completely inhibit the binding of the clones 1035 and 2022 to immobilized nickel, implicating that the peptides were able to chelate nickel ions. These studies reveal that bacterial surface displayed peptide libraries may have promising future potential for the development of metal bioadsorbents. Furthermore, novel Ni-binding peptides may provide lead molecules for Ni-chelation and applications thereof.

Amino Acid Sequence↗

PubMed2006

Identification of a new spore wall protein from Encephalitozoon cuniculi.

Microsporidia form environmentally resistant spores that are critical for their host-to-host transmission and persistence in the environment. The spore walls of these organisms are composed of two layers, the exospore and the endospore. Two spore wall proteins (SWP1 and SWP2) have been previously identified in members of the Encephalitozoonidae family. These proteins localize to the exospore. The endospore is known to contain chitin, and a putative glycosylphosphatidylinositol (GPI)-anchored chitin deacetylase has been localized to the plasmalemma-endospore interface. Using proteomic techniques, we have identified a new spore wall protein (SWP3) that is located in the endospore. The gene for this protein is located on chromosome 1 and corresponds to the open reading frame ECU01_1270. SWP3 is predicted to have a signal peptide and to be GPI anchored. Consistent with these modifications, two-dimensional electrophoresis demonstrated that SWP3 has an acidic pI and a molecular mass of <20 kDa. By immunoelectron microscopy, this protein was found on the cell surface during sporogony and in the endospore in mature spores. SWP3 has several potential O-glycosylation sites, and it is possible that it is a mannosylated protein like the major polar tube protein (PTP1).

Amino Acid Sequence↗

PubMed2006

Protective effects of breviscapine on ischemic vascular dementia in rats.

Breviscapine, a traditional Chinese medicine, is extensively used in clinic to treat cardiovascular diseases and cerebrovascular injury. In this study, we demonstrated the effects of breviscapine on vascular dementia (VD) rats, which were mimicked by permanent occlusion of bilateral common carotid arteries. Breviscapine (2 mg/kg for 14 d) improved the performance of learning and memory of VD rats in Morris water maze, decreased the level of lipid peroxidation and free radicals, and attenuated the pathological alterations, such as nuclear shrink, cellular edema and irregular arrangement of pyramidal layer in the hippocampal CA(1) area. In vitro experiment, breviscapine (50 microg/l) protected cortical neuron from injury and decreased intracellular calcium overloading induced by H2O2 (10 mM). The results suggest that breviscapine has therapeutic effect on cerebral ischemia and vascular dementia.

Animals↗

PubMed2006

Production of biodiesel by immobilized Candida sp. lipase at high water content.

A new process for enzymatic synthesis of biodiesel at high water content (10-20%) with 96% conversion by lipase from Candida sp. 99-125 was studied. The lipase, a no-position-specific lipase, was immobilized by a cheap cotton membrane and the membrane-immobilized lipase could be used at least six times with high conversion. The immobilized lipase could be used for different oil conversion and preferred unsaturated fatty acids such as oleic acid to saturated fatty acids such as palmitic acid. The changes in concentration of fatty acids, diglycerides, and methyl esters in the reaction were studied and a mechanism of synthesis of biodiesel was suggested: the triglycerides are first enzymatically hydrolyzed into fatty acids, and then these fatty acids are further converted into methyl esters.

Alkanes↗

PubMed2006

[Isolation, identification and functional characterization of human CD4+ CD25+ Treg cells from human peripheral blood].

AIM: To isolate CD4(+) CD25(+) Treg cells from human peripheral blood, and study their functional characteristics. METHODS: The expressions of Foxp3 in human CD4(+) CD25(+) Treg cells were test by RT-PCR. The regulatory properties of CD4(+) CD25(+) Treg cells were assessed by co-culturing with CD4(+) CD25(-) T cells and CD8(+) T cells, or adding exogenous IL-2. The detection of intracellular cytokine production of IL-4, IL-10 and IFN-gamma was done by flow cytometry. RESULTS: CD4(+) CD25(+) Treg cells highly expressed Foxp3 and mainly synthesized IL-10 that suppressed the proliferation of CD4(+) CD25(-) T and CD8(+) T cells. Its suppressive function was reversed by high concentration of IL-2 and (or) IL-4. CONCLUSION: CD4(+) CD25(+) Treg cells exhibited a subpopulation of immunoregulatory T cells with suppressive function, which could be reversed by high concentration of IL-2.

Blood Cells↗

PubMed2006

Effect of Panax notoginseng saponins on lipopolysaccharide-induced adhesion of leukocytes in rat mesenteric venules.

Panax notoginseng is the root of the Chinese traditional herb, Panax notoginseng (Burk) F.H. Chen. This study was aimed to investigate the inhibitory effect of Panax notoginseng saponins (PNS) on the leukocyte adhesion and the expression of adhesion molecules in rat mesentery venules. Male Sprague-Dawley rats were anesthetized with urethane. These were divided into control, LPS (perfused with lipopolysaccharide), and PNS group (perfused with PNS). The mesenteric microcirculation was observed under a videomicroscope. The number of adherent leukocytes, which attached to the vascular wall during more than 10 seconds, was counted along single venules (30-50 microm in diameter, 200 microm in length). The expression of adhesion molecules was examined using flow-cytometry in blood which was taken from the abdominal aorta and incubated with FITC-labeled CD11b (or CD18) antibodies. The results showed that different changes in the leukocyte adhesion and the expression of adhesion molecules among three groups. In LPS group, the leukocyte adhesion increased significantly after 20 minutes during the observation time, while it was reduced markedly in PNS group. The expression of CD11b and CD18 on the neutrophils was induced in LPS group, while it was reduced significantly in PNS group. It was suggested that PNS could reduce leukocyte adhesion in venules under the inhibitory effect on the expression of adhesion molecules (CD11b and CD18) on neutrophils.

Animals↗

PubMed2006

Inhibition effect of cardiotonic pills on venous thrombosis induced in rat mesentery by photochemical reaction.

This paper was aimed to explore the inhibition effect of cardiotonic pills (CP) on venous thrombosis induced in rat mesentery by photochemical stimulation (PS). Male Sprague-Dawley rats were anesthetized with urethane. Thrombosis was induced in the mesenteric venule by PS with photosensitizer hematoporphyrin and an ultraviolet beam. The rats were divided into three groups: control (n = 6), PS (n = 6) and PS + CP group (n = 6) where CP solution (0.4 g/kg.b) was administrated orally 60 min before PS. Microcirculatory disturbances in the mesentery were observed under an inverted microscope with a color video-camera. Based on the recorded images, the development of thrombosis was evaluated in term of time of thrombosis appearance (T(a)) and area ratio of thrombus/vessel (AR). The expression of adhesion molecule (CD31) of platelet was examined in blood taken from the abdominal aorta, using flow cytometry. The T(a) was approximately 10 seconds after PS in PS group, but it was approximately 20 seconds in PS + CP group. The AR in PS + CP group was significantly reduced, compared to that in PS group, during the period of the observation. The CD31 expression was not changed in both groups, while positive cells were significantly increased in the number. It is suggested that CP might suppress thrombus development under the interaction of platelet with endothelium.

Animals↗

PubMed2006

[Inhibitory effects of tetraethylammonium on proliferation and voltage-gated potassium channels in human cervical carcinoma cell line SiHa].

BACKGROUND & OBJECTIVE: Various potassium channels are known to be involved in proliferation of many malignant cell lines. This study was to explore the role of voltage-gated potassium channels in proliferation of human cervical carcinoma cells through observing the effects of tetraethylammonium (TEA) on proliferation and outward potassium currents in human cervical carcinoma cell line SiHa. METHODS: SiHa cells were treated with TEA. The effect of TEA on proliferation of SiHa cells was assessed by MTT assay. Cell apoptosis and cell cycle were detected by flow cytometry with Hoechst 33258 staining. The outward potassium currents were recorded by patch clamp technique. RESULTS: TEA inhibited the proliferation of SiHa cells in dose-and time-dependent manners, and induced cell apoptosis. The cell cycle was arrested at G0/G1 phase after treatment with TEA. Exposure of SiHa cells to 10 mmol/L TEA reduced the peak outward potassium currents significantly from (260+/-12) pA to (58+/-6) pA (P<0.01). CONCLUSIONS: Voltage-gated potassium channels play an important role in regulating proliferation of cervical carcinoma SiHa cells. Blocking voltage-gated potassium channels could inhibit proliferation of SiHa cells.

Apoptosis↗

PubMed2006

[Human coronavirus-NL63 was detected in specimens from children with acute respiratory infection in Beijing, China].

OBJECTIVE: A new human coronavirus, HCoV-NL63, was identified recently from two Dutch children with acute respiratory infection (ARI) by two scientists in the Netherlands in 2004. To investigate if this newly discovered virus is associated with acute respiratory infections in pediatric patients in Beijing, tests were developed to detect HCoV-NL63 gene fragments from throat swab and nasopharyngeal aspirates collected from children in outpatient and inpatient departments with ARI in Beijing from Dec. 2003 to Mar. 2004. METHODS: A total of 245 clinical samples, which were negative either for diagnostic tests of human respiratory syncytial virus, influenza virus A and B, adenovirus, parainfluenza virus 1, 2 and 3 by indirect immunofluorescence assay or human metapneumovirus by RT-PCR, were screened for HCoV-NL63 by nested PCR amplifying gene fragments located on the 1b and 1a genes. Amplicon of PCR from 1a gene of HCoV-NL63 was sequenced and the sequences were compared with those in GenBank nucleotide sequence database. RESULTS: Three (1.2%) out of the 245 samples were positive for HCoV-NL63 by nested-PCR using primers on 1b gene. These three samples also showed positive results on nested PCR in which primers were designed with sequences complementary to 1a gene segments. These positive samples were collected from hospitalized children under 2 years of age with pneumonia, bronchiolitis and bronchitis, respectively. The partial 1a gene sequences from two positive samples (BJ3140 and BJ3787) of HCoV-NL63 showed 100% homology between each other and high homology (98%-99%) with the sequences of 1a gene of HCoV-NL63 reported from different countries in GenBank. Phylogenetic analysis showed that BJ3140 and BJ3787 fell into the same genetic cluster (group 1). CONCLUSIONS: These data suggest that some of acute respiratory infections in young children in Beijing area are related to the newly identified HCoV-NL63.

Acute Disease↗

PubMed2006

[Prognostic value of N-terminal-pro-brain natriuretic peptide on admission in patients with chronic heart failure].

OBJECTIVE: Heart failure is responsible for a huge burden in hospital care. Our goal was to evaluate the value of N-terminal-pro-brain natriuretic peptide (Nt-proBNP) on predicting death or hospital readmission after hospital discharge in patients with chronic heart failure (CHF). METHODS: From March 2003 to April 2005, 135 consecutive patients (97 male and 38 female, mean age 60.7 years +/- 13.1 years) with chronic heart failure [dilated cardiomyopathy (44%) and coronary heart disease (35%)] were included in this study. Plasma concentrations of the Nt-proBNP were measured by ELISA on admission. All patients received conventional therapy and were followed up for 24 months. The primary end point was death or readmission. RESULTS: (1) During the follow up period (640 days +/- 100 days), 11 patients died and 39 patients rehospitalized, the median Nt-proBNP level on admission was significantly higher in patients died during the follow up period (5908 ng/L) than that of rehospitalized patients (2768 ng/L, P = 0.038). Plasma Nt-proBNP level on admission were significantly higher in primary end point group (n = 50, 2947 ng/L) than that in non-primary end point group (n = 85, 917 ng/L, P < 0.01). (2) Variables associated with an increased hazard of death and/or rehospitalization were Nt-proBNP and NYHA degree when analyzed by logistic regression models. Increased Log Nt-proBNP was the strongest independent predictor of an adverse outcome of CHF (odds ratio 13.8, 95% confidence interval 2.29 to 2.78, P < 0.01). (3) Area under the curve for Nt-proBNP in evaluating prognosis of CHF patients was 0.885 (positive predictive value 88.5%, negative predictive value 11.5%). CONCLUSION: Nt-proBNP level on admission is a strong predictor of rehospitalization and death within 24 months after hospital discharge in patients with chronic heart failure.

Adolescent↗

PubMed2006

[Clinical studies on level of N-terminal portion of brain natriuretic in the treatment and prognosis of Chinese patients with chronic left heart failure].

OBJECTIVE: To study the relationship of the level of N-terminal portion of brain natriuretic (NT-ProBNP) with the treatment and prognosis of patients with acute attack of chronic left heart failure. METHODS: Patients (age range 18-80 years) with decompensated heart failure treated in the emergency department in Fuwai Hospital were included in this study. Dynamic changes of plasma levels of NT-ProBNP, angiotensin (AO), renin activity (PRA), angiotensin II (AT II) and aldosterone (ALD) were detected by enzyme linked immunoadsorbent assay (ELISA) before anti-cardiac failure treatment and 3-5, 5-7 days after the treatment. All enrolled patients were followed up for 2 years after leaving hospital, and cardiovascular events such as death, myocardial infarction, worsening of heart failure, severe arrhythmia or delayed discharge from hospital were recorded. RESULTS: Compared with baseline level at admission, plasma NT-ProBNP levels were lowered on 3rd -5th day and 5th-7th day after admission and treatment (both P<0.05) in 44 patients with chronic left heart failure, but there was no difference in NT-ProBNP levels between the 3rd-5th and 5th -7th day after treatment. The levels of plasma NT-ProBNP increased much higher at all observation times in patients with cardiovascular events than without the events (all P<0.05), but the changes in AO, PRA, ATII and ALD showed no significant difference between two groups (all P>0.05). CONCLUSION: During acute onset, plasma NT-ProBNP levels in patients with chronic left heart failure can be lowered at 3-7 days after admission and treatment. Higher baseline levels of plasma NT-ProBNP may have certain predictive values for long term prognosis in patients with chronic left heart failure.

Adolescent↗

PubMed2006

[Effect of chlorpyrifos residue in red soil on crops].

The pot cultivation experiment method, integrating with laboratory analysis, was employed for exploring the influence of chlorpyrifos residue in red soil on growth of wheat and oil-seed rape seedlings, and the uptake of crops to chlorpyrifos residue. The results show that, wheat seedlings and oil-seed rape seedlings can absorb chlorpyrifos residue from soil to reach the concentration of 0.257 to approximately 4.50 microg/g and 0.249 to approximately 2.021 microg/g, respectively, 20 days later since chlorpyrifos was introduced into the pots, on condition that the initial concentration of chlorpyrifos residue in red soil was 1 to approximately 10 microg/g. The initial concentration of chlorpyrifos residue in red soil equivalent to or below 10 micro/g has not significant influence on growth of wheat seedlings. Similarly, the concentration equivalent to or below 5 microg/g has not significant influence on growth of oil-seed rape seedlings. The degradation rate in oil-seed rape rhizosphere soil is 1.4 to approximately 4.2 times more than in that in unvegetated soil. The amount of bacterium and fungus in oil-seed rape rhizosphere is 3.18 times and 1.84 times as much as these in unvegetated soil, respectively. However, there is no substantial difference of actinomyces between in rhizosphere soil and in unvegetated soil. Compared with unvegetated soil, pH in rhizosphere soil is lowered by 0. 19 to approximately 0.23.

Chlorpyrifos↗

PubMed2006

[Parainfluenza virus infections in pediatric patients with acute respiratory infections in Beijing during 2001 - 2003].

OBJECTIVE: To understand the relationship of parainfluenza virus (PIV) and acute respiratory infections in infants and young children in Beijing, occurred in recent years. METHODS: 3141 throat swab/nasopharyngeal aspirate specimens were collected from infants and young children with acute respiratory tract infections in Beijing from Jan 2001 to Dec 2003. All of these 3141 specimens were inoculated into MDCK cells for influenza virus and PIV isolation, since PIV had been isolated in MDCK cells in this laboratory from preliminary studies. Out of 3141 specimens, 702 were inoculated into MDCK as well as Vero cells to compare the sensitivity on virus isolation of these cell lines by micro plate method. Growth of PIV in cell culture were identified by haemoagglutination test and indirect immunofluorescent assay. RESULTS: The PIV positive cases in Vero cells were also positive in MDCK cells, indicating that the sensitivity for PIV isolation in MDCK was equal to Vero cells. Out of these 3141 specimens, 94 (3.0%) were PIV positive, including 35 (35/1191, 2.9%) of PIV1, 11 (11/1191, 0.9%) of PIV3 in upper respiratory tract infections; 15 (15/1634, 0.9%) of PIV1, 24 (24/1634, 1.5%) of PIV3 in lower respiratory tract infections; 3 (3/207, 1.4%) of PIV in asthma; 1 (1/38) of PIV in patients with fever; 5 (5/71) of PIV in others. Data indicated that among upper respiratory tract infections caused by PIV, PIV1 was more commonly seen than PIV3. CONCLUSION: MDCK cells could be used for PIV isolation from clinical samples while PIV was one of the important pathogenic viruses causing acute respiratory tract infections in infants and young children in Beijing for the recente years.

Acute Disease↗

PubMed2006

[Human rhinovirus detection from infants and young children with acute respiratory infections by nested-polymerase chain reaction].

OBJECTIVE: To develop a rapid, sensitive and specific method for detection human rhinovirus (HRV) from clinical specimens. METHODS: Primers derived from the highly conserved 5'noncoding region of human rhinovirus were used to develop a nested RT-PCR for detecting HRV. The sensitivity and specificity of the RT-PCR were determined using various RNA while DNA viruses were used as control. Seven hundred and seventy-one specimens collected from children with symptoms of acute respiratory infections from Nov. 2002 to Oct. 2003 were analyzed for HRV by RT-PCR as well as for other respiratory viruses through isolation of virus and indirect immunofluorescent assay. RESULTS: Only the cDNA from HRV was positive by RT-PCR, indicating the nested RT-PCR was specific. With RT-PCR, HRV were detected in 148 out of 771 specimens (19.2%). As for HRV positive rates, it was found 53.3% in pharyngitis patients; 43.8% in laryngitis patients and 28.7% in bronchitis patients. In Sep. 2002 and from Aug. 2003 to Oct. 2003, HRV positive rates were high (21.6% - 32.6%), with Sep. 2003 in particular--32.6%. From Mar. 2003 to Jul. 2003, HRV positive rates maintained from 16.0% to 19.1%. CONCLUSION: HRV was one of the important agents for acute respiratory infections in infants and young children in Beijing.

5' Untranslated Regions↗

PubMed2006

[Serological analysis of SARS Coronavirus in children diagnosed clinically as severe acute respiratory syndrome cases during SARS epidemic in Beijing].

OBJECTIVE: To identify the etiologic agents from children who had been clinically diagnosed as severe acute respiratory syndrome (SARS) during the epidemic in Beijing and to characterize the transmissibility of SARS from those children to others. METHODS: One hundred and seventy-seven serum specimens were collected during the period of June to August, 2003 from children and adults who had been clinically diagnosed as SARS and who closely contacted with those diagnosed as SARS during SARS epidemic in Beijing. Serum specimens were also collected from 49 children from Anhui province which was non-epidemic region and 93 healthy kindergarten children without history of contacting with SARS patients in Beijing during SARS epidemic. Serum specimens collected from 90 healthy kindergarten children in Beijing in September 2002 were included in the study. All the 409 serum specimens were tested for specific antibodies against SARS-associated coronavirus (SARS-CoV) by different methods including ELISA for specific IgM and IgG, whole antibodies against SARS-CoV, IFA for specific IgM and IgG against SARS-CoV, and Western-blot for IgG to expressed N protein from SARS-CoV. RESULTS: The positive rates of specific IgG and whole antibodies against SARS-CoV ranged from 39.1% to 43.5% in the children who had been clinically diagnosed as SARS, zero in children and 6.0% to 9.0% in adults who had closely contacted with the clinically diagnosed SARS children. Among those clinically diagnosed SARS adult patients, the positive rates of specific IgG and whole antibodies against SARS-CoV were 57.1% to 71.4%. In children and adults who closely contacted with these clinically diagnosed SARS adult patients, the positive rates of specific IgG and whole antibodies against SARS-CoV were 0 to 9.7% and 4.4% to 7.1%, respectively. None of the serum specimens collected from healthy children before and during epidemic in Beijing and children from non-epidemic region was positive when IFA methods and ELISA with Beier kits were used for detection, but some were positive when ELISA with the diagnostic kit from other source was applied. CONCLUSION: The positive rates of specific IgG and whole antibodies against SARS-CoV in children who had been clinically diagnosed as SARS were around 40%, which is much lower than the positive rate in clinically diagnosed adult SARS patients, indicating that a large proportion of those "SARS" children were infected with respiratory viruses other than SARS-CoV during SARS epidemic in Beijing. Some of the children who closely contacted with children and adults SARS patients showed positive SARS-CoV antibodies, suggesting that asymptomatic infections may occur. The value of some approved diagnostic kit at least in children for SARS etiological diagnosis needs to be analyzed further.

Adult↗