Epidemiological and Immunological Features of Influenza Viruses in Hospitalized Children with Influenza Illness in Hangzhou.

Objectives: We evaluated the epidemiological features and various inflammatory markers in hospitalized children with influenza virus infection in China. Methods: The real-time RT-PCR assay was performed for detection and genotyping of influenza A and B virus. Th1/Th2 cytokines, WBC, and CRP were determined in influenza virus positive children. Results: H1N1 and Yamagata were the prevalent genotypes of influenza A and B virus in Hangzhou, respectively. IL-2, IL-10, and CRP were significantly increased and IFN-γ was decreased in children with severe Influenza A virus infection, and TNF-α and IFN-γ levels were found to be significantly lower in children with severe Influenza B virus infection. Conclusion: Increased IL-2, IL-10, and CRP with decreased IFN-γ may indicate a severe influenza A virus infection, and decreased TNF-α and IFN-γ may indicate a severe influenza B virus infection in children.

Mycoplasma pneumoniae induces allergy by producing P1-specific immunoglobulin E.

BACKGROUND: Our previous study found that most Mycoplasma pneumoniae (MP) pneumonia (MPP)patients had elevated serum total immunoglobulin E (IgE) levels. OBJECTIVE: To determine components of MP that can cause an IgE increase in children, and to clarify its specific mechanism. METHODS: The components of MP cells were isolated by serum IgE from patients with MP pneumonia. These components obtained through the prokaryotic expression were used as allergens to detect the proportion of allergen-specific IgE produced in MPP patients, and the clinical characteristics and related immune parameters of these patients who produced this allergen-specific IgE were also analyzed. In addition, a cell experiment was used to verify the biological effect of these components in vitro. RESULTS: P1-specific IgE was detected in serum of MPP children. An approximately 24-kDa polypeptide of P1 protein was obtained through prokaryotic expression purified by nickel agarose affinity chromatography. Approximately 9.2% of MPP patients produced IgE against this polypeptide of P1 protein, which was more likely to be produced in MPP patients with no history of allergies or family history of allergy-related diseases. P1-specific IgE-positive MPP patients had more severe clinical symptoms, with excessive secretion of interleukin (IL)-4 and IL-5 and overdifferentiation of Th0 cells into Th2 cells. Tests also demonstrated that the P1 protein stimulated excessive secretion of IL-4 and IL-5 in peripheral blood mononuclear cells from the peripheral blood of healthy donors. CONCLUSION: Mycoplasma pneumoniae is not only an infectious agent but also an allergen for certain individuals. The P1 protein of MP can induce the production of P1-specific IgE.

Utility of cytokines to predict neonatal sepsis.

BACKGROUND: Sepsis is an important cause of neonatal morbidity and mortality worldwide. Diagnosis and treatment of neonatal sepsis relies on clinical judgment and interpretation of nonspecific laboratory tests. In a prospective cohort, we measured inflammatory cytokines as a potential biomarker for neonatal sepsis. METHODS: Serum inflammatory cytokine levels were evaluated in the early stage of neonatal sepsis and after antimicrobial treatment. Receiver operating characteristic curves assessed the diagnostic value of cytokines. We performed multiple logistic regression analysis to characterize the role of each cytokine independently for infants with culture proven sepsis. RESULTS: C-reactive protein, interleukin (IL)-6, IL-10 and IL-6/IL-10 levels were significantly elevated in neonatal sepsis when compared with the control group and there were 1.4 (95% confidence interval (CI): 1.2-1.5), 4.9 (95% CI: 4.6-5.1), 5.1 (95% CI: 4.5-5.6), and 10.2 (95% CI: 9.2-11.1) fold greater odds, respectively, to predict neonatal sepsis when increased. After effective treatment, median IL-6 (pretreatment value: 263.0 pg/ml and post-treatment value: 7.4 pg/ml) and IL-6/IL-10 levels (pretreatment value: 16.6 and post-treatment value: 1.4) significantly decreased. The areas under the curve for IL-6, IL-10, IL-6/IL-10 and C-reactive protein for differential diagnosis were 0.98, 0.82, 0.90, and 0.88, respectively. CONCLUSION: IL-6 and IL-6/IL-10 outperformed C-reactive protein to diagnose neonatal sepsis. Of the cytokines studied, IL-6 was the most sensitive, whereas IL-6/IL-10 was the most specific predictor of neonatal sepsis.

Intravenous immunoglobulin treatment responsiveness depends on the degree of CD8+ T cell activation in Kawasaki disease.

Kawasaki disease (KD) has become the most common cause of acquired heart disease in children and is also a risk factor for ischemic heart disease in adults. However, Kawasaki disease lacks specific laboratory diagnostic indices. Thus, this study analyzed the T cell activation profiles of Kawasaki disease and assessed their value in the diagnosis of Kawasaki disease and the prediction of intravenous immunoglobulin (IVIG) sensitivity. We analyzed human leukocyte antigen-DR (HLA-DR), CD69 and CD25 expression on peripheral blood CD4+ and CD8+ T cells during the acute phase of KD. We compared the percentages of HLA-DR+/CD69+/CD25+ T cells in the CD4+ and CD8+ T cell populations of IVIG-effective and IVIG-resistant groups. Receiver operating characteristic curves were used to assess the diagnostic value of the above parameters. The median percentage of CD8+HLA-DR+ T cells and the median ratio of CD8+HLA-DR+ T cells/CD8+CD25+ T cells were significantly elevated in the patient group compared with those in the control group during the acute phase of KD. Regarding the diagnosis of Kawasaki disease, the area under the ROC curve was 0.939 for the percentage of CD8+HLA-DR+ T cells. There was a significant difference in the ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells between IVIG-resistant patients and IVIG-sensitive patients. Regarding IVIG sensitivity, the area under the ROC curve was 0.795 for it. Excessive CD8+ T cell activation, as well as an imbalance between CD8+ T cell activation and inhibition, underlies the pathogenesis of Kawasaki disease. The percentage of CD8+ HLA-DR+ T cells may be used as an index to diagnose Kawasaki disease. IVIG inhibits CD8+ T cell activation, but excessive CD8+ T cell activation may cause IVIG resistance. The ratio of CD8+HLA-DR+ T cells/CD8+CD69+ T cells may be used as a predictor of IVIG sensitivity.

Isolation of autophagosome subpopulations after induction of autophagy by calcium.

Autophagy is a dynamic process accomplished by the generation and maturation of autophagosomes. Isolation of autophagosomes and subsequent compositional analysis can provide information about their biogenesis mechanism. In this article, HEK293 cells expressing GFP-LC3 were treated by calcium phosphate precipitates (CPP) to induce autophagy. The autophaogomes induced by CPP were tubular and vesicular structures, extensively formed in the cytosol. After all membranes in the cell lysate were fractionated by differential centrifugation, autophagosomes from light and heavy membranes were isolated by immuno-precipitation, using antibodies against GFP-LC3 and Atg5. We found that GFP-LC3 and Atg5 positive autophagosomes represented distinctive subpopulations. Judged from the molecular markers associated, including organelle markers and Atg proteins, GFP-LC3 positive autophagosomes were overall at the later biogenetic stage. Furthermore, both GFP-LC3 and Atg5 positive autophagosomes from light membranes were less mature than those from heavy membranes. We have established a method to isolate subpopulations of autophagsomes for further characterization.

Epidemiological characteristics and immune status of children with Respiratory Syncytial Virus.

Respiratory Syncytial Virus (RSV) infections are the dominant cause of pneumonia in children. In order to determine the epidemiological characteristics and immune status of children with Respiratory Syncytial Virus, a prospective study was performed among patients with RSV infection. Comparisons between RSV pneumonia group and normal control group, RSV pneumonia group had lower IL-2 (median levels, pg/ml: 3.8 vs. 5.1, P < 0.01), and higher IL-4 (median levels, pg/ml: 3.2 vs. 2.4, P < 0.01), IL-10 (median levels, pg/ml: 12.2 vs. 2.3, P < 0.01), and IFN-γ (median levels, pg/ml: 13.4 vs. 4.6, P < 0.01). The level of IgE among pneumonia patients caused by RSV increased sharply (median levels, mg/L: 48.1 vs. 8.8, P < 0.01). Another amazing finding is that after birth, the degree of IgE of the children infected by RSV increases gradually with age. This effect is at its peak in 0.6 years old. The IgE and eosinophil levels were higher when patients suffered from RSV pneumonia with wheeze (IgE median levels, IU/ml: with wheeze: 72.74 vs. without wheeze: 11.5, P < 0.05; eosinophil median levels, ×10(9) /l: with wheeze: 0.21 vs. without wheeze: 0.05, P < 0.05). The main morbidity crowd is the children under the age of 1 year old. The downregulation of IL2 and the upregulation of IL-4, IL-10, IFN-γ, and IgE happen after RSV infection.

Epidemiology of childhood enterovirus infections in Hangzhou, China.

BACKGROUND: There are over 100 serotypes of enterovirus species A-D, which are the common cause of various symptoms in infants, such as meningitis, encephalitis and hand foot mouth disease (HFMD). This study aims to investigate the epidemiological characteristics of enteroviruses in Hangzhou, Zhejiang province, China, and to provide relevant information to guide public health responses and interventions. METHODS: Systematic surveillance was conducted on enterovirus infections. Samples were collected from children admitted to the inpatient wards and outpatient departments between January 2010 and December 2012 in the Children's Hospital, Zhejiang University School of Medicine. Enteroviruses from all specimens were detected by RT-PCR using a commercialized detection kit. RESULTS: From 13026 samples collected and examined, 2673 (21.21%) were found positive for enteroviruses. The annual enterovirus-positive rate decreased from 32.78% in 2010 to 14.23% in 2012. Positivity rate for enteroviruses was highest among children aged less than 5 years. The monthly positivity rate for enterovirus infection ranged from 2.6% to 34.83%, with a peak in June and July. Serotypes causing severe symptoms such as HFMD including EV71 and CA16 were decreasing, while the proportion of unidentified EV serotypes causing herpangina and viral encephalitis were on the rise. CONCLUSIONS: EV infection is highly prevalent among young children in Hangzhou, as it is in the most other parts of the world. Further surveillance using methods that can subtype all EVs is warranted to better monitor these infections and their etiology.

[Determination of ascitic bacterial 16S rRNA by quantitative PCR-microarray in the diagnosis of spontaneous bacterial peritonitis].

OBJECTIVE: To evaluate the significance of determining ascitic bacterial 16S rRNA by quantitative PCR combined with microarray (PCR-microarray) in the diagnosis of spontaneous bacterial peritonitis (SBP). METHODS: Ascitic bacterial 16SrRNA was determined by real time fluorescent quantitative PCR-microarray in 76 cases of suspected SBP and 6 cases of non-infectious ascites with chronic liver diseases. The results were compared with ascitic bacterial culture simultaneously. RESULTS: Of 76 ascitic samples, 17 were detected bacteria positive by PCR-microarray, including 8 Grams positive(G+) and 9 Grams negative(G-), which was higher than that by bacterial culture which had only 6 ascitic samples detected positive (all G-); the positive rates were 22.4% vs 7.9%, respectively (P < 0.01). The bacterial strains detected by both methods in 6 cases had a consistency with each other. No bacteria were detected in another 6 cases of non-infectious ascites with chronic liver diseases. CONCLUSIONS: Determination of ascitic bacteria 16S rRNA by PCR-microarray has a higher specificity and sensitivity in the diagnosis of SBP as compared with the bacteria culture. Application of this novel method can not only accelerate SBP diagnosis but also stratify the different pathogens.

[Mannose-binding lectin (MBL) inhibits human cytomegalovirus infection of human MD-DC].

OBJECTIVE: To explore the inhibitory effect of different sources, different concentrations of Mannose-binding lectin (MBL) on human cytomegalovirus infection of human MD-DC cells. METHODS: The recombinant MBL was acquired by vector construction, and the natural MBL was purified from human plamsa. MD-DC were pre-exposed to several dilutions of the hMBL/rMBL for 30 min, then HCMV suspensions were added to MD-DC for 2 h to compare the inhibitory effect of hMBL/rMBL on the HCMV infection of MD-DC. MD-DC infected by HCMV co-culture with hMBL/rMBL to compare the inhibitory effect of hMBL/rMBL on the HCMV diffusion between MD-DC. HCMV-DNA in MD-DC was detected by fluorescence quantitative PCR. HCMV-PP65 in MD-DC was analyzed with flow cytometry, the ability of MD-DC to capture HCMV was observed with immunofluorescence confocal microscope. RESULTS: In hMBL/rMBL inhibition the ability of MD-DC capture HCMV experiments, the fluorescent quantitative PCR demonstrated that the amount of HCMV-DNA in 1 microg/mL of hMBL/rMBL treated cells was not significantly different from that of control group (P < 0.05). But the HCMV-DNA in 5 microg/mL and 10 microg/mL hMBL/rMBL treated group were significantly lower than that of control group (P < 0.05). The significant inhibit effects of 10 microg/mL hMBL/rMBL on the ability of MD-DC capture HCMV were observed by immunofluorescence confocal microscopy and flow cytometry. The inhibit effects of hMBL/rMBL on HCMV diffusion between MD-DC were also observed in 5 microg/mL and 10 microg/mL hMBL/rMBL treated groups at 72 hours. CONCLUSION: The hMBL/rMBL in physiological concentration range (5-10 microg/mL) can significantly inhibit human cytomegalovirus infection of human MD-DC cells, and the hMBL is more effective than rMBL.

The detection and clinical features of human cytomegalovirus infection in infants.

The aim is to investigate the spectrum of disease in 378 infants with human cytomegalovirus infection. In these patients, 27.78% were systemic infection and 72.22% involved single organ infection. Hepatitis, thrombocytopenic purpura, pneumonia were predominant with 33.07%, 13.49%, 6.35% respectively. The rate of HCMV systemic infection in infants younger than 2 weeks was higher than in those older than 2 weeks. The gB genotype analysis in 107 cases showed 53 gBI, 20 gBII, 18 gBIII, 7 gBI+gBII, 5 gBI+gBIII and 4 gBII+gBIII. These results suggest that HCMV can infect multiorgan and has varietal clinic feature. The gBI genotype is most prevalent.

Rapid diagnosis of bacterial meningitis in children with fluorescence quantitative polymerase chain reaction amplification in the bacterial 16S rRNA gene.

Polymerase chain reaction (PCR) techniques have been increasingly used to detect microbial DNA in cerebrospinal fluid (CSF) for the diagnosis of bacterial meningitis. In order to determine the rapidity, sensitivity and specificity of 16S rRNA-based fluorescence quantitative polymerase chain reaction (FQ-PCR), 16S rRNA-based FQ-PCR, CSF bacterial culture and CSF routine analysis were compared in the diagnosis of bacterial meningitis in children. Twenty children who were clinically suspected of bacterial meningitis were included in this study. A total of 2.0 ml of CSF was collected from every child and was subjected to 16S rRNA-based FQ-PCR, CSF culture and CSF routine analysis. Bacterial DNA copies and the cycle threshold (CT) value of the 16S rRNA-based FQ-PCR was recorded, and the results were compared with CSF culture and CSF routine analysis. Seven children were found to be positive with a rate of 35% (7/20) when detected with 16S rRNA-based FQ-PCR and four children displayed a positive rate of 20% (4/20) with the CSF culture method. These two groups displayed a significant difference, with a p-value of 0.002. The method of 16S rRNA-based FQ-PCR demonstrated a high specificity when compared to the standard microbes. A negative correlation was noted between the CT value and the bacteria DNA copies, and the CT value was indicative of the seriousness of bacterial meningitis. 16S rRNA-based FQ-PCR was proved to be a more rapid, sensitive and specific method compared with CSF culture and it should have promising usage in the diagnosis of bacterial meningitis.

Rapid diagnosis of sepsis and bacterial meningitis in children with real-time fluorescent quantitative polymerase chain reaction amplification in the bacterial 16S rRNA gene.

A method for the detection of bacterial pathogens in sepsis and bacterial meningitis with 16S rRNA gene- based real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) is developed. A total of 190 blood specimens and 5 cerebrospinal fluid specimens from neonates with suspected sepsis or bacterial meningitis were evaluated with 16S rRNA gene-based real-time FQ-PCR assay. The positive rate of the real-time FQ-PCR assay was significantly higher (25/195, 12.82%) than that of bacterial culture (15/195, 7.69%; P = .002). When bacterial culture was used as a control, the sensitivity of the real-time FQ-PCR was 100%, the specificity was 94.4%, and Youden's index was 0.944. This study suggests that 16S rRNA gene-based real-time FQ-PCR assay is an important and accurate method in the detection of bacterial pathogens of sepsis and bacterial meningitis and should have a promising usage in the diagnosis of sepsis and bacterial meningitis.

Efficient inhibition of human cytomegalovirus UL122 gene expression in cell by small interfering RNAs.

In order to develop a gene therapy to human cytomegalovirus (HCMV), RNA interference (RNAi) was employed to inhibit the expression of HCMV UL122 gene in vitro. Recombinant vector pUL122-EGFP, which expressed UL122-EGFP fusion protein, and recombinant vectors psi122-1, psi122-2 and psi122-3, which expressed small interfering RNAs (siRNAs) targeted to UL122 were contransfected into AD293 cells. The fluorescence signal of pUL122-EGFP was greatly suppressed by psi122-1 and psi122-2, with an inhibitory rate of 82.0% +/- 1.0% and 79.5% +/- 2.5%, respectively. The mRNA of pUL122-EGFP of the cells transfected with psi122-1 and psi122-2 was decreased 97.3% +/- 0.6% and 98.0% +/- 0.1%, respectively. Vector psi122-3 showed a slightly low suppression rate. Therefore, it may be concluded that plasmids encoding siRNAs targeted to UL122 is able to in vitro reduce markedly the expression of UL122-EGFP. And it is very likely that the psi122-1 and psi122-2 are potentially efficacious siRNAs in the gene therapy of HCMV infection in vivo, in which further investigations are required. This study is expected to greatly facilitate the use of the RNAi technology for the anti-HCMV studies.

Gram stain-specific-probe-based real-time PCR for diagnosis and discrimination of bacterial neonatal sepsis.

Sepsis is a serious disease with high mortality in newborns. It is very important to have a convenient and accurate method for pathogenic diagnosis of neonatal sepsis. We developed a method of simultaneous detection and Gram classification of clinically relevant bacterial pathogens causing sepsis directly from blood samples with Gram stain-specific-probe-based real-time PCR (GSPBRT-PCR). With GSPBRT-PCR, 53 clinically important strains representing 25 gram-positive and 28 gram-negative bacterial species were identified correctly with the corresponding Gram probe. The limits of the GSPBRT-PCR assay in serial dilutions of the bacteria revealed that Staphylococcus aureus could be detected at concentrations of 3 CFU per PCR and Escherichia coli at concentrations as low as 1 CFU per PCR. The GSPBRT-PCR assay was further evaluated on 600 blood specimens from patients with suspicion of neonatal sepsis and compared to the results obtained from blood cultures. The positive rate of the GSPBRT-PCR array was 50/600 (8.33%), significantly higher than that of blood culture (34/600; 5.67%) (P = 0.00003). When blood culture was used as a control, the sensitivity of GSPBRT-PCR was 100%, the specificity was 97.17%, and the index of accurate diagnosis was 0.972. This study suggests that GSPBRT-PCR is very useful for the rapid and accurate diagnosis of bacterial infection and that it can have an important impact on the current inappropriate and unnecessary use of antibiotics in the treatment of newborns.

[Establishment of quantifying and typing analysis of 16S rRNA gene by real-time PCR].

OBJECTIVE: To explore a new method of rapid and reliable diagnosis of bacterial infectious diseases such as purulent meningitis and septicemia. METHODS: A pair of universal primers and a set of probes (including universal fluorescence probe, Gram-positive probe and Gram-negative probe) were designed based on the bacterial highly conserved region of 16S rRNA gene. By using the FQ-PCR method, 12 standard strains, 23 clinical cultural isolations and the controls such as HBV, Cryptococcus histolyticus, Blastomyces albicans and human DNA were detected with the three kinds of probes. The correlation among the results of the three kinds of probes detection was analyzed. RESULTS: The determination of 16S rRNA gene with FQ-PCR was a highly specific and sensitive method and not cross-reactive with human DNA, virus or fungi. The least amount of 10 copies of 16S rRNA gene which corresponded to 2 bacteria could be detected with FQ-PCR. Twelve standard strains and 23 clinical cultural isolations were detected by FQ-PCR with the three kinds of probes mentioned above. All samples presented positive results using the universal probe. The results of 16S rRNA gene detected by the Gramjpositive probe were positive to the 18 G+ strains. The results of 16S rRNA gene detected by the Gram-probe were positive to the 17 G- strains. CONCLUSIONS: The FQ-PCR technique was established for bacteria quantifying and typing using the universal primer and the double type probes. This method was convenient and rapid in detecting, quantifying and typing bacteria, with a high specificity and sensitivity.

Sialic Acid and Iron Content in Breastmilk of Chinese Lactating Women.

OBJECTIVE: To study sialic acid and iron content in breastmilk in Chinese women during different lactation stages. METHODS: Sialic acid and iron content of colostrum, transitional milk, mature milk, and involutional milk were determined using a neuraminidase assay kit and the ferrozine method, respectively in 88 lactating women (58 Term, 30 Preterm). RESULTS: The mean (SD) sialic acid levels of colostrum, transitional milk, mature milk, and involutional milk were 2201.4 (676.6) mg/L, 1445.9 (423.4) mg/L, 395.3 (96.0) mg/L and 273.0 (76.9) mg/L, respectively. The median iron content were 0.05 mg/L, 0.06 mg/L, 0.25 mg/L and 0.35 mg/L, respectively, in successive stages of lactation. Sialic acid and iron were significantly higher in breast milk of preterm mothers compared to term mothers. CONCLUSION: Sialic acid and iron content in breast milk vary greatly throughout the lactation stages, which probably reflects the infants' needs for growth and development at different stages.

Evaluation of a real-time method of simultaneous amplification and testing in diagnosis of Mycoplasma pneumoniae infection in children with pneumonia.

Mycoplasma pneumoniae (M. pneumoniae) infection can cause community acquired pneumonia in children. A real-time method of simultaneous amplification and testing of M. pneumoniae (SAT-MP) was developed to diagnose M. pneumoniae targeting a region of the ribosomal RNA. The SAT-MP assay can accurately identify M. pneumoniae with a detection range from 101 to 107 CFU/ml. In this study, the specimens from 315 children with pneumonia were collected and analyzed by SAT-MP in parallel with real-time PCR method and IgM ELISA assay. The positive rates of these specimens examined by SAT-MP assay, real-time PCR method and IgM ELISA assay were 16.51%, 15.56% and 12.70% respectively. While there was statistical significance (p = 0.04) between SAT-MP assay and IgM ELISA assay, no statistical significance (p = 0.25) was found between SAT-MP assay and real-time PCR method and these two methods had high consistency (kappa value = 0.97). These findings indicate that the newly developed SAT-MP assay is a rapid, sensitive and specific method for identifying M. pneumoniae with potential clinical application in the early diagnosis of M. pneumoniae infection.

Epidemiological Features and Antibiotic Resistance Patterns of Haemophilus influenzae Originating from Respiratory Tract and Vaginal Specimens in Pediatric Patients.

STUDY OBJECTIVE: Haemophilus influenzae (H. influenzae) is a common pathogen of respiratory tract infections in children, however, as a possible cause of vulvovaginitis in prepubertal girls, its epidemiological features, antibiotic-resistance patterns, and treatment are seldom noted. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Specimens obtained from patients were inoculated on Haemophilus selective medium; and drug-sensitivities tests were determined using the disk diffusion method. A cefinase disk was used to detect ß-lactamase. RESULTS: A total of 610 H. influenzae strains, 81.6% (498/610) from the respiratory tract and 18.0% (110/610) from the vagina, were identified in the Children's Hospital in 2015. The age of the children with respiratory tract strains were significantly younger than those with vaginal strains (P < .001). The H. influenzae isolation rate in May was the highest. The ß-lactamase positive rate was 51.5% (314/610), and 52.5% (320/610) were resistant to ampicillin. The susceptibilities rates to cefuroxime, ampicillin/sulbactam, cefotaxime, clarithromycin, and sulfamethoxazole-trimethoprim were 72.1% (440/610), 95.9%, 96.4% (588/610), 81.8% (499/610), and 36.4% (222/610), respectively. Higher resistance to ampicillin, cefuroxime, clarithromycin, and sulfamethoxazole-trimethoprim were found in respiratory tract strains, compared with vaginal strains (P < .05). All of the patients with H. influenzae in the respiratory tract were cured with oral or intravenous ß-lactam antibiotics. Of all patients with vaginal strains, 50% (55/110) were cured with topical ofloxacin gel, and 44.5% (49/110) were cured with oral ß-lactam antibiotics. CONCLUSION: The drug-resistance rates of H. influenzae isolated from vagina were lower than those from the respiratory tract. Topical ofloxacin gel or oral ß-lactam antibiotics are effective treatments to eliminate the H. influenza causing infection in the vagina.

Inhibitive effects of anti-oxidative vitamins on mannitol-induced apoptosis of vascular endothelial cells.

OBJECTIVE: Study blood vessel injury and gene expression indicating vascular endothelial cell apoptosis induced by mannitol with and without administration of anti-oxidative vitamins. METHODS: Healthy rabbits were randomly divided into four groups. Mannitol was injected into the vein of the rabbit ear in each animal. Pre-treatment prior to mannitol injection was performed with normal saline (group B), vitamin C (group C) and vitamin E (group D). Blood vessel injury was assessed under electron and light microscopy. In a second experiment, cell culture specimen of human umbilical vein endothelial cells were treated with mannitol. Pre-treatment was done with normal saline (sample B), vitamin C (sample C) and vitamin E (sample D). Total RNA was extracted with the original single step procedure, followed by hybridisation and analysis of gene expression. RESULTS: In the animal experiment, serious blood vessel injury was seen in group A and group B. Group D showed light injury only, and normal tissue without pathological changes was seen in group C. Of all 330 apoptosis-related genes analysed in human cell culture specimen, no significant difference was seen after pre-treatment with normal saline, compared with the gene chip without pre-treatment. On the gene chip pre-treated with vitamin C, 45 apoptosis genes were down-regulated and 34 anti-apoptosis genes were up-regulated. Pre-treatment with vitamin E resulted in the down-regulation of 3 apoptosis genes. CONCLUSION: Vitamin C can protect vascular endothelial cells from mannitol-induced injury.

[Pathogenic bacteria of childhood lower respiratory tract infection].

OBJECTIVE: To study the pathogenic bacteria of lower respiratory tract infection (LRTI), and age and gender distribution and drug resistance of the pathogenic bacteria in children. METHODS: Sputum specimens for bacterial cultures were collected in sterile tubes from all of the children with LRTI who had been admitted to the Children's Hospital of Zhejiang University between August 2001 and July 2002. Antibiotic susceptibility tests were performed using the Vitek system, the Kirby-Bauer diffuse method and the Etest method after bacteria were identified. RESULTS: Among the 4,238 patients with LRTI during the study period, 1,181 patients were bacteria-positive, with a positive rate of 27.9%. Streptococcus pneumoniae (S. pneumoniae) was the most common (222 strains), followed by Haemophilus influenzae (H. influenzae) (216 strains), Klebsiella pneumoniae (K. pneumoniae) (216 strains), Escherichia coil (E. coli) (169 strains) and Staphylococcus aureus (S. aureus) (89 strains). The isolation rate of S. pneumoniae in females was significantly higher than in males (6.2% vs 4.7%; P < 0.05). However, the isolation rates of K. pneumoniae and S. aureus in males were higher than in females (5.1% vs 4.1% and 2.5% vs 1.5%, respectively; P < 0.05). A higher incidence of LRTI due to S. pneumoniae and H. influenzae was found in the 1-3 years group, while the incidence of LRTI due to K. pneumoniae, E. coli, S. aureus and E. cloacae was higher in patients under 1 year of age. Antibiotic susceptibility tests showed that rates of penicillin non-susceptible S. pneumoniae, ampicillin resistant H. influenzae, oxacillin-resistant S. aureus and ESBL-positive K. pneumoniae and E. coli were 55.0%, 16.5%, 41.2%, 42.6% and 4.5%, respectively. CONCLUSIONS: S. pneumoniae, H. influenzae, K. pneumoniae, E. coli and S. aureus were common pathogens of LRTI in children. The infection rate varied with age and gender. Antibiotics for treating LRTI should be selected based on the drug susceptibility test.