[Correlation between fractional exhaled nitric oxide and airway reversibility in children with IgE-mediated asthma].

OBJECTIVE: To study the correlation between fractional exhaled nitric oxide (FeNO) and airway reversibility in children with IgE-mediated asthma. METHODS: A total of 86 children, aged 6-14 years, who were initially diagnosed with acute attack of asthma from September 2016 to August 2018 were enrolled as subjects. According to the results of serum specific IgE, they were divided into IgE mediated group with 61 children and non-IgE mediated group with 25 children. According to the results of allergen detection, the IgE mediated group was further divided into four groups with one, two, three, and four or more positive allergens. FeNO and the parameters of pulmonary ventilation function before and after dilation test were measured. Pearson correlation analysis was used to evaluate the correlation of FeNO with each parameter of pulmonary function. RESULTS: The IgE mediated group had significantly higher FeNO than the non-IgE mediated group (P<0.05). FeNO increased with the increase in the number of positive serum specific allergens (P<0.05). In the IgE mediated group, FeNO level was positively correlated with the change in forced expiratory volume in the first second (FEV1) and the improvement in percentage of predicted FEV1 after medication in bronchial dilation test (r=0.655 and 0.473 respectively, P<0.05). The FeNO level was not correlated with FEV1, percentage of predicted FEV1, peak expiratory flow (PEF), change in PEF after medication, percentage of predicted PEF (PEF%pred), and improvement in PEF%pred after medication (P>0.05). In the non-IgE mediated group, FeNO level was not correlated with the above indicators (P>0.05). CONCLUSIONS: FeNO level is associated with the degree of allergies. For children with IgE-mediated asthma, FeNO is positively correlated with airway reversibility, which has a certain value in the diagnosis of asthma, disease evaluation, and understanding of airway reversibility. For children with non-IgE-mediated asthma, FeNO cannot be used to evaluate airway reversibility. These two types of asthma should be treated differently.

[Association of ORMDL3 single nucleotide polymorphisms with lysophosphatidylcholine and apolipoprotein B levels in children with asthma].

OBJECTIVE: To study the association of ORMDL3 single nucleotide polymorphisms (SNP) with lysophosphatidylcholine (LysoPC) and apolipoprotein B (apoB) levels. METHODS: A total of 300 children diagnosed with bronchial asthma between January 2010 and December 2012 were selected for the asthma group, and 298 children diagnosed with upper respiratory tract infection in the same period were selected for the control group. Serum LysoPC and apoB levels were measured using enzyme-linked immunosorbent assay. Genotype analysis was performed using the TaqMan probe. RESULTS: LysoPC and apoB levels were significantly higher in the asthma group than in the control group (P<0.01). Among children with various genotypes of ORMDL3 gene at locus rs12603332, the asthma group had significantly higher LysoPC and apoB levels than the control group (P<0.01). Among the children with asthma, those with CC genotype had significantly higher LysoPC and apoB levels than those with CT and TT genotypes (P<0.01). CONCLUSIONS: LysoPC and apoB may intervene in the pathological process of asthma. Pro-inflammatory gene ORMDL3 SNP rs12603332 may be associated with high LysoPC and apoB levels, which leads to the occurrence of childhood asthma.

[Epidemiological survey of asthma among children aged 0-14 years in 2010 in urban Zhongshan, China].

OBJECTIVE: To investigate the prevalence, current treatment, and clinical characteristics of asthma, as well as the risk factors for this disease, among children aged 0-14 years in 2010 in urban Zhongshan, China. METHODS: A total of 10 336 children aged 0-14 years were selected from urban Zhongshan by cluster random sampling. The Third National Childhood Asthma Epidemiological Questionnaire 2010 was used to analyze the prevalence, current treatment, and clinical characteristics of childhood asthma, as well as the risk factors for this disease. RESULTS: Asthma was diagnosed in 179 cases (1.73%). The prevalence of asthma in male children was significantly higher than that in female children (2.25% vs 1.16%; P<0.01). Of the 179 patients, severe attacks were common in 104 cases (58.1%), 110 cases (61.5%) had slow onset, 102 cases (57.0%) had gradually relieved conditions, 61 cases (34.1%) suffered from asthma during seasonal transition, and 150 cases (83.8%) developed asthma due to respiratory tract infection. Among all asthmatic children, 71.5% had been treated with inhaled corticosteroids, and 71.5% had been treated with bronchodilator. The multivariate logistic regression analysis showed that a history of penicillin allergy, a family history of allergy, food allergy, eczema, allergic rhinitis, cesarean delivery, family mould, and perinatal passive smoking were independent risk factors for childhood asthma. CONCLUSIONS: The prevalence of childhood asthma in urban Zhongshan is on a high level, and is associated with gender. The treatment of asthma has been standardized, but still needs further improvement. The onset of asthma attack is influenced by various factors.

The expression of beclin-1, an autophagic gene, in hepatocellular carcinoma associated with clinical pathological and prognostic significance.

BACKGROUND: A role for autophagy, a conserved cellular response to stress, has recently been demonstrated in human cancers. Aberrant expression of Beclin-1, an important autophagic gene, has been reported in various human cancers. In the present study, we investigated the significance and relationship between Beclin-1 expression and cell proliferation, apoptosis, microvessel density (MVD) and clinical pathological changes or prognosis in human hepatocellular carcinoma (HCC). METHODS: A total of 103 primary HCC patients were involved in the study. Expression of Beclin-1, PCNA, NET-1, Bcl-2, Bax, Survivin in cancer cells and CD34 in stromal microvessels were evaluated immunohistochemically in tissue microarrays comprising 103 cases of HCC and 57 matched adjacent nontumor liver tissues. Correlations between clinicopathological characteristics and survival of HCC patients were explored. RESULTS: The positive rate of Beclin-1 was significantly lower in HCC tissues than adjacent tissues (72.8 vs. 89.5%, χ2 = 6.085, P = 0.015). In HCC, Beclin-1 expression was negatively correlated with cirrhosis background (r = -0.216, P = 0.029), Edmondson grade (r = -0.249, P = 0.011), vascular invasion (r = -0.246, P = 0.012), PCNA (r = -0.242, P = 0.014), NET-1 (r = -0.245, P = 0.013), anti-apoptosis protein Bcl-2 (r = -0.245, P = 0.013) and MVD (r = -0.292, P = 0.003), and positively correlated with pro-apoptosis protein Bax (r = 0.242, P = 0.014).Significant differences in the 5-year survival rates were seen among patients with Beclin-1 strong positive (++) (59.1%, 13/22), moderate positive (+) (28.3%, 15/53) and weak negative expression (-) (14.6%, 7/28) (P = 0.043). Significant differences were detected between Beclin-1 (++) and either Beclin-1 (+) (P = 0.036) or Beclin-1 (-) groups (P = 0.008), but no significant difference between Beclin-1 (+) and Beclin-1 (-) groups (P = 0.281) was observed.Survival rates were positively related to high Beclin-1 co-expressed with low PCNA, NET-1, or Bcl-2, lower MVD, and high Bax. Univariate and multivariate Cox regression analysis revealed that Beclin-1 expression was an independent indicator for overall survival in HCC patients (P < 0.05). CONCLUSIONS: The pathogenesis and progression of HCC are associated with reduced autophagy. The expression of Beclin-1 and Bax in HCC tissues may provide a synergistic effect towards inhibiting HCC proliferation, infiltration, metastasis and angiogenesis. Beclin-1 expression may be a valuable prognostic marker of HCC.

Application of the CellDetect® staining technique in diagnosis of human cervical cancer.

BACKGROUND: CellDetect® staining technique is a newly invented technique for cancer diagnosis. It easily distinguishes between normal and neoplastic cells including pre-cancer and squamous cell carcinoma (SCC) cells, based on staining color and morphology. In this study, application of CellDetect® staining technique was assessed in diagnosis of human cervical cancer as compared with hematoxylin and eosin (H&E) staining in conventional slides and Thinprep cytologic test (TCT) smears. METHODS: The conventional slides and TCT smears of 600 patients were stained and observed while comparing with H&E staining to assess sensitivity and specificity of CellDetect® staining technique in diagnosis of cervical cancer. Conventional smear slides (440 cases) were fixed in 95% ethanol or with CYTOFIX® Spray. TCT smears (160 cases) were processed based on manual. The paraffin sections from cervical intraepithelium neoplasia (CIN) 2-3 and SCC cases were prepared by biopsy. RESULTS: CellDetect® staining exhibited well cell morphology, simultaneously, showed dual color discrimination, the stain targeted cytoplasm in normal cells in green and dysplastic cells or neoplastic cells in purple/red. Both cervical cell smears or both fixation methods in conventional slides did not affect CellDetect® staining diagnosis, especially in tissue biopsies CellDetect® staining exhibited well epithelium layers to benefit the diagnosis of CIN grade. The sensitivity and specificity of CellDetect® staining technology in diagnosing CIN and SCC were 94.34% and 88.73%, respectively. CONCLUSIONS: CellDetect® staining technique provided a dual color discrimination and morphological analysis. It has the potential to become one of the most effective methods for cervical screening and early diagnosis.

Effects of lentiviral-mediated Foxp1 and Foxq1 RNAi on the hepatocarcinoma cell.

Foxp1 and Foxq1 are two multifunctional molecules of "forkhead box (Fox)" family. The objective of this paper was to construct the lentiviral vectors expressing RNA interference (RNAi) against Foxp1 or Foxq1 genes, and the effects of both vectors with two RNAis on the proliferation, migration and apoptosis of 7721 hepatocarcinoma cell line were evaluated. Six target sequences against human Foxp1/Foxq1 mRNA were designed respectively and six pairs of their corresponding double-strand DNA oligo (siRNA) were synthesized prior to being transfected into 7721 cells with lipo2000, then a most efficient siRNA were selected to be subcloned into pLL3.7-GFP/Lenti plasmids. These plasmids were transfected into 293T cells to package lentiviral particles for subsequent transfection into 7721 cells after their sequences were confirmed. The expression of Foxp1and Foxq1 genes in the transfected cells were identified by real-time PCR. The migration, infiltration, viability and apoptosis of the transfected cells were assessed by wound healing assay, Transwell assay, CCK-8 assay and flow cytometry. Sequencing results showed that lentiviral vectors contained Foxp1 or Foxq1 gene. After being transfected into 7721 cells, Foxp1 and Foxq1 expression were significantly down-regulated by siRNA-823 and siRNA-834. The migration and infiltration ability, and the viability of 7721 cells transfected with two siRNAs were significantly suppressed; flow cytometry assay exhibited the apoptosis rate of transfected 7721 cells with the lentivirus RNAi vector of Foxp1 or Foxq1 was increased. All the results showed that the lentivirus RNAi vectors of Foxp1 and Foxq1 were able to inhibit the expression of Foxp1 and Foxq1 in 7721 cells efficiently, and the down-regulation of either Foxp1 or Foxq1 resulted in suppression of migration, infiltration and viability of 7721 cells and an increase in cell apoptosis. Our data indicated that both Foxp1 and Foxq1 genes played an oncogenic role in hepatocarcinoma cells, which proposed the two genes as new therapeutic targets for the cancer.

A synthetic dsRNA, as a TLR3 pathwaysynergist, combined with sorafenib suppresses HCC in vitro and in vivo.

BACKGROUND: Recent studies have demonstrated that synthetic dsRNAs may produce therapeutic effects in a target-independent manner through stimulation of the toll-like receptor-3 (TLR3)/interferon pathway; as a result, angiogenesis and proliferation of tumor cells are inhibited. Thus, this pathway may become a potential target of dsRNA in tumor suppression. In this study, we evaluated the role of synthetic dsRNA as a TLR3 synergist and by combining with sorafenib in anti-hepatocellular carcinoma (HCC) in vitro and in vivo. METHODS: Four dsRNAs were designed and synthesized. One of them that was capable of activating TLR3 most effectively in human HCC cell line (HepG2.2.15) was selected as a TLR3 synergist (called BM-06). Subsequently, the expression of proteins relating to TLR3 signaling pathway, such as NF-κB, caspase 8 survivin, bcl-2 and PCNA affected by BM-06, sorafenib alone or in combination, was compared. The migration, proliferation and apoptosis of HepG2.2.15 cells were evaluated in presence of BM-06, sorafenib alone or in combination of both. The similar treatments were also applied in an SD rat primary HCC model. RESULTS: qRT-PCR data showed that the expression of TLR3 and NF-κB in HepG2.2.15 cells was enhanced. BM-06 was selected as a TLR3 synergist capable of activating the TLR3/interferon pathway most effective among 4 synthetic dsRNAs. The migration and proliferation were significantly inhibited in treated HepG2.2.15 cells with BM-06 or Sorafenib alone as compared with PBS-sham control (P<0.01). However, the role of combination BM-06 with Sorafenib was the most prominent. Tumor cell apoptotic rate was increased by BM-06 or combination when compared to PBS or poly(I:C) (P<0.05). Similarly, in orthotopic HCC SD rats, the effect of the combination was superior to either agent alone on the inhibition of tumor growth and induction of HCC cell apoptosis (P<0.05). CONCLUSIONS: dsRNA alone was capable of inhibiting the proliferation of HepG2.2.15 cells and tumor growth of orthotopic HCC SD rats, but the effect of combination of dsRNA with sorafenib was more prominent. These findings implicate the potential role of combined use of a dsRNA, a TLR3 synergist, and sorafenib in inhibition of HCC.

[Spectrum of pathogens for community-acquired pneumonia in children].

OBJECTIVE: To investigate the spectrum of pathogens for community-acquired pneumonia (CAP) in children, and to provide a basis for the diagnosis and treatment of CAP. METHODS: Respiratory secretions and venous blood samples were collected from 1560 children with CAP aged from one month to 9 years within 2 hours after admission, for detection of multiple pathogens. Respiratory virus antigens in nasopharyngeal swab specimens were detected by immunofluorescence. Sputum was used for bacterial culture. Levels of Mycoplasma pneumoniae (MP)-IgM and Chlamydia pneumoniae (CP)-IgM in venous blood were measured by enzyme-linked immunosorbent assay. RESULTS: A total of 579 strains of bacteria were isolated from all respiratory secretions, including 213 (36.8%) Gram-positive strains and 366 (63.2%) Gram-negative strains. The five most common strains were Haemophilus influenzae (7.50%), Streptococcus pneumoniae (6.73%), Staphylococcus aureus (6.35%), Moraxella catarrhalis (5.19%), and Escherichia coli (3.46%), wherein the beta-lactamase-producing strains accounted for 3.3% of all strains. The non-bacterial pathogens mainly included respiratory syncytial virus (12.88%), MP (7.88%), and CP (8.91%). Mixed infection of pathogens was serious, and the mixed infection of respiratory syncytial virus with Haemophilus influenzae infections were the most common. For most pathogens, the infection rate was higher in children aged under one year than in those aged over one year. CONCLUSIONS: Haemophilus influenzae, respiratory syncytial virus, MP and CP are the main pathogens for children with CAP. For most pathogens, the infection rate is higher in children aged under one year than in those aged over one year. Mixed infection rate of pathogens is high.

Polarity-regulated derivatization-assisted LC-MS method for amino-containing metabolites profiling in gastric cancer.

Amino-containing compounds, including amino acids, aliphatic amines, aromatic amines, small peptides and catecholamines, are involved in various biological processes and play vital roles in multiple metabolic pathways. Previous studies indicated that some amino-containing metabolites are significant diagnostic and prognostic biomarkers of gastric cancer. However, the discovery of precise biomarkers for the preoperative diagnosis of gastric cancer is still in an urgent need. Herein, we established a polarity-regulated derivatization method coupled with liquid chromatography-mass spectrometry (LC-MS) for amino-containing metabolites profiling in the serum samples of patients with gastric cancer and healthy controls, based on our newly designed and synthesized derivatization reagent (S)-3-(1-(diisopropoxyphosphoryl) pyrrolidine-2-carboxamido)-N-hydroxysuccinimidyl ester (3-DP-NHS). Enhanced separation efficiency and detection sensitivity for amino-containing metabolites were achieved after derivatization. This method exhibited good linearity, recovery, intra- and inter-day precision and accuracy. Only 5 µL serum is needed for untargeted analysis, enabling 202 amino-containing metabolites to be detected. Statistical analysis revealed altered amino acid metabolisms in patients with gastric cancer. Furthermore, ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS) analysis quantification revealed increased serum levels of tryptamine and decreased concentrations of arginine and tryptophan in patients with gastric cancer. Receiver operating characteristic (ROC) curves indicated that an increased tryptamine/tryptophan ratio could serve as a potential biomarker for gastric cancer diagnosis. This study demostrated the possibility of using serum amino acid biomarkers for gastric cancer diagnosis, providing new avenues for the treatment of gastric cancer.

Developing red-emissive ruthenium(II) complex-based luminescent probes for cellular imaging.

Ruthenium(II) complexes have rich photophysical attributes, which enable novel design of responsive luminescence probes to selectively quantify biochemical analytes. In this work, we developed a systematic series of Ru(II)-bipyrindine complex derivatives, [Ru(bpy)(3-n)(DNP-bpy)(n)](PF(6))(2) (n = 1, 2, 3; bpy, 2,2'-bipyridine; DNP-bpy, 4-(4-(2,4-dinitrophenoxy)phenyl)-2,2'-bipyridine), as luminescent probes for highly selective and sensitive detection of thiophenol in aqueous solutions. The specific reaction between the probes and thiophenol triggers the cleavage of the electron acceptor group, 2,4-dinitrophenyl, eliminating the photoinduced electron transfer (PET) process, so that the luminescence of on-state complexes, [Ru(bpy)(3-n)(HP-bpy)(n)](2+) (n = 1, 2, 3; HP-bpy, 4-(4-hydroxyphenyl)-2,2'-bipyridine), is turned on. We found that the complex [Ru(bpy)(DNP-bpy)(2)](2+) remarkably enhanced the on-to-off contrast ratio compared to the other two (37.8 compared to 21 and 18.7). This reveals a new strategy to obtain the best Ru(II) complex luminescence probe via the most asymmetric structure. Moreover, we demonstrated the practical utility of the complex as a cell-membrane permeable probe for quantitative luminescence imaging of the dynamic intracellular process of thiophenol in living cells. The results suggest that the new probe could be a very useful tool for luminescence imaging analysis of the toxic thiophenol in intact cells.

A ratiometric luminescence probe for highly reactive oxygen species based on lanthanide complexes.

Reactive oxygen species (ROS) are important mediators in a variety of pathological events, but the oxidative stress owing to excessive generation of ROS is implicated in many human diseases. In this work, we designed and synthesized a novel dual-functional chelating ligand, [4'-(p-aminophenoxy)methylene-2,2':6',2''-terpyridine-6,6''-diyl]bis(methylenenitrilo)tetrakis(acetic acid) (AMTTA), that can strongly coordinate with both Eu(3+) and Tb(3+) in aqueous solutions for the recognition and time-gated luminescence detection of highly ROS (hROS), hydroxyl radical ((•)OH), and hypochlorite (ClO(-)). The complexes AMTTA-Ln(3+) (Ln = Eu and Tb) are almost nonluminescent because of the photoinduced electron transfer from the electron-rich aminophenyl group to the terpyridine-Ln(3+) moiety but can rapidly react with hROS to afford highly luminescent complexes (4'-hydroxymethyl-2,2':6',2''-terpyridine-6,6''-diyl)bis(methylenenitrilo)tetrakis(acetate)-Ln(3+) (HTTA-Ln(3+)). Interestingly, when the AMTTA-Eu(3+)/Tb(3+) mixture (AMTTA/Eu(3+)/Tb(3+) = 2/1/1) was reacted with hROS, the intensity ratio of its Tb(3+) emission at 540 nm to its Eu(3+) emission at 610 nm, I(540)/I(610), showed a ratiometric response toward hROS, and the dose-dependent increase of the ratio displayed a double-exponential correlation to the concentration of hROS. This unique luminescence response allowed the AMTTA-Eu(3+)/Tb(3+) mixture to be used as a ratiometric probe for the time-gated luminescence detection of hROS.

Design and synthesis of a terbium(III) complex-based luminescence probe for time-gated luminescence detection of mercury(II) ions.

Time-gated luminescence detection technique using lanthanide complexes as luminescent probes is a useful and highly sensitive method. However, the effective application of this technique is limited by the lack of the target-responsive luminescent lanthanide complexes that can specifically recognize various analytes in aqueous solutions. In this work, a dual-functional ligand that can form a stable complex with Tb(3+) and specifically recognize Hg(2+) ions in aqueous solutions, N,N,N(1),N(1)-{[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-[N,N-bis(3″,6″-dithiaoctyl)-aminomethyl]- pyridine]} tetrakis(acetic acid) (BBAPTA), has been designed and synthesized. The luminescence of its Tb(3+) complex is weak, but can be effectively enhanced upon reaction with Hg(2+) ions in aqueous solutions. The luminescence response investigations of BBAPTA-Tb(3+) to various metal ions indicate that the complex has a good luminescence sensing selectivity for Hg(2+) ions, but not for other metal ions. Thus a highly sensitive time-gated luminescence detection method for Hg(2+) ions was developed by using BBAPTA-Tb(3+) as a luminescent probe. The dose-dependent luminescence enhancement of the probe shows a good linearity with a detection limit of 17 nM for Hg(2+) ions. These results demonstrated the efficacy and advantages of the new Tb(3+) complex-based luminescence probe for the sensitive and selective detection of Hg(2+) ions.

[Efficacy of specific sublingual immunotherapy with dermatophagoides farinae drops in the treatment of cough variant asthma in children].

OBJECTIVE: To study the efficacy and safety of specific sublingual immunotherapy with dermatophagoides farinae drops in the treatment of cough variant asthma in children. METHODS: A total of 106 children aged 4-14 years old with cough variant asthma and positive skin prick test responses to dermatophagoides farinae allergens were randomly divided into two groups: SLIT group (n=53), which received specific sublingual immunotherapy with dermatophagoides farinae drops as well as standardized treatment and conventional treatment group (n=53), which received standardized treatment alone. Improvement in cough/asthma symptom scores and the time taken for symptoms to improve were observed after treatment. Serum eosinophil (EOS) level and peak expiratory flow (PEF) were measured after treatment. The side effects were observed. RESULTS: Compared with the conventional treatment group, the SLIT group showed significant decrease in symptom scores and serum EOS level and significant increase in PEF (P<0.05). The time at which symptoms began to improve in the SLIT group was earlier than in the conventional treatment group (P<0.05). The effective rate in the SLIT group was significantly higher than in the conventional treatment group (85% vs 68%; P<0.05). Local reactions such as redness, swelling, and itching occurred in some children of the SLIT group but disappeared on the following day. CONCLUSIONS: Specific sublingual immunotherapy with dermatophagoides farinae drops is an effective and highly safe treatment for cough variant asthma in children.

[Study of genetic susceptibility in 198 children with asthma].

OBJECTIVE: To analyze the frequency distribution of single nucleotide polymorphisms (SNPs) of four asthma-related gene loci (ACE I/D; ADRB2 Arg16Gly; TNF-α G-308A; MS4A2 Glu237Gly) in 198 asthmatic children, and to investigate its association with genetic susceptibility to childhood asthma and some clinical phenotypes of asthma. METHODS: Polymerase chain reaction product electrophoresis identification and real-time quantitative PCR detecting system were used to determine the frequency distributions of the SNPs of the four asthma-related gene loci in 198 asthmatic children and 110 healthy controls. The serum total IgE (TIgE) levels and blood eosinophil proportion (%EOS) of the asthmatic children were measured. Different genotypes at the four asthma-related gene loci were compared in terms of TIgE and %EOS. RESULTS: The genotype DD of angiotensin-converting enzyme (ACE) had a significantly higher frequency in the asthmatic children than in the healthy controls (χ2= 30.667, P<0.01), and the frequency of D allele was also significantly higher in the asthmatic children than in the healthy controls (χ2=7.151, P<0.01). No correlation was found between the polymorphism of each gene locus and serum TIgE level and %EOS (P>0.05). CONCLUSIONS: Genotype DD of ACE is related to genetic susceptibility to childhood asthma and may be the risk factor for childhood asthma.

Development of a terbium complex-based luminescent probe for imaging endogenous hydrogen peroxide generation in plant tissues.

A highly sensitive Tb(3+) complex-based luminescent probe, N,N,N(1),N(1)-[2,6-(3'-aminomethyl-1'-pyrazolyl)-4-(3'',4''-diaminophenoxy)methylene-pyridine] tetrakis(acetate)-Tb(3+) (BMTA-Tb(3+)), has been designed and synthesized for the recognition and detection of hydrogen peroxide (H(2)O(2)) in aqueous solutions. This probe is almost nonluminescent because the Tb(3+) luminescence is effectively quenched by the electron-rich moiety, diaminophenyl, on the basis of the photoinduced electron transfer (PET) mechanism. In the presence of peroxidase, the probe can react with H(2)O(2) to cause the cleavage of the diaminophenyl ether, which affords a highly luminescent Tb(3+) complex, N,N,N(1),N(1)-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-hydroxymethyl-pyridine] tetrakis(acetate)-Tb(3+) (BHTA-Tb(3+)), accompanied by a 39-fold increase in luminescence quantum yield with the increase of luminescence lifetime from 1.95 to 2.76 ms. The dose-dependent luminescence enhancement of the probe shows a good linearity with a detection limit of 3.7 nM for H(2)O(2), which is approximately 14-fold lower than those of the commonly used fluorescent probes. The probe was used for the time-resolved luminescence imaging detection of the oligosaccharide-induced H(2)O(2) generation in tobacco leaf epidermal tissues. On the basis of the probe, a background-free time-resolved luminescence imaging method for detecting H(2)O(2) in complicated biological systems was successfully established.

A ruthenium(II) complex based turn-on electrochemiluminescence probe for the detection of nitric oxide.

Electrochemiluminescence (ECL) detection technique using bipyridine-ruthenium(II) complexes as probes is a highly sensitive and widely used method for the detection of various biological and bioactive molecules. In this work, the spectral, electrochemical and ECL properties of a chemically modified bipyridine-ruthenium(II) complex, [Ru(bpy)(2)(dabpy)](2+) (bpy: 2,2'-bipyridine; dabpy: 4-(3,4-diaminophenoxy)-2,2'-bipyridine), were investigated and compared with those of its nitric oxide (NO)-reaction derivative [Ru(bpy)(2)(T-bpy)](2+) (T-bpy: 4-triazolephenoxy-2,2'-bipyridine) and [Ru(bpy)(3)](2+). It was found that the ECL intensity of [Ru(bpy)(2)(dabpy)](2+) could be selectively and sensitively enhanced by NO due to the formation of [Ru(bpy)(2)(T-bpy)](2+) in the presence of tri-n-propylamine. By using [Ru(bpy)(2)(dabpy)](2+) as a probe, a sensitive and selective ECL method with a wide linear range (0.55 to 220.0 µM) and a low detection limit (0.28 µM) was established for the detection of NO in aqueous solutions and living cells. The results demonstrated the utility and advantages of the new ECL probe for the detection of NO in complicated biological samples.

[Etiology and risk factors of infantile wheezing].

OBJECTIVE: To study the etiology and risk factors of infantile wheezing. METHODS: The clinical data of 180 infants with wheezing were retrospectively studied. The risk factors for wheezing attacks were investigated by logistic regression analysis. RESULTS: Viral infection (33.3%) was the most common cause for wheezing attacks, followed by asthma (19.4%), parental smoking and special environments (15.6%), gastroesophageal reflux disease (12.8%), premature delivery (7.8%), Mycoplasma infection (6.7%), and bronchopulmonary dysplasia (4.4%). The multivariate logistic regression analysis showed 7 factors that significantly correlated with wheezing attacks: allergic history of parents, sensitization to alimentary or inspiratory allergens, viral or Mycoplasma infection, premature delivery and special environments. CONCLUSIONS: The commonest cause of infantile wheezing is viral infection, followed by asthma. Genetic factors, individual atopic constitution and environmental factors play important roles in wheezing attacks.

Development of a visible-light-sensitized europium complex for time-resolved fluorometric application.

The time-resolved luminescence bioassay technique using luminescent lanthanide complexes as labels is a highly sensitive and widely used bioassay method for clinical diagnostics and biotechnology. A major drawback of the current technique is that the luminescent lanthanide labels require UV excitation (typically less than 360 nm), which can damage living biological systems and is holding back further development of time-resolved luminescence instruments. Herein we describe two approaches for preparing a visible-light-sensitized Eu(3+) complex in aqueous media for time-resolved fluorometric applications: a dissociation enhancement aqueous solution that can be excited by visible light for ethylenediaminetetraacetate (EDTA)-Eu(3+) detection and a visible-light-sensitized water-soluble Eu(3+) complex conjugated bovine serum albumin (BSA) for biolabeling and time-resolved luminescence bioimaging. In the first approach, a weakly acidic aqueous solution consisting of 4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-o-terphenyl (BHHT), 2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine (DPBT), and Triton X-100 was prepared. This solution shows a strong luminescence enhancement effect for EDTA-Eu(3+) with a wide excitation wavelength range from UV to visible light (a maximum at 387 nm) and a long luminescence lifetime (520 micros), to provide a novel dissociation enhancement solution for time-resolved luminescence detection of EDTA-Eu(3+). In the second approach, a ternary Eu(3+) complex, 4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-chlorosulfo-o-terphenyl (BHHCT)-Eu(3+)-DPBT, was covalently bound to BSA to form a water-soluble BSA-BHHCT-Eu(3+)-DPBT conjugate. This biocompatible conjugate is of the visible-light excitable feature in aqueous media with a wide excitation wavelength range from UV to visible light (a maximum at 387 nm), a long luminescence lifetime (460 micros), and a higher quantum yield (27%). The conjugate was successfully used for streptavidin (SA) labeling and time-resolved luminescence imaging detection of three environmental pathogens, Giardia lamblia , Cryptosporidium muris , and Cryptosporidium parvum , in water samples. Our strategy gives a general idea for designing a visible-light-sensitized Eu(3+) complex for time-resolved luminescence bioassay applications.

Development of a ruthenium(II) complex based luminescent probe for imaging nitric oxide production in living cells.

A unique ruthenium(II) complex, bis(2,2'-bipyridine)(4-(3,4-diaminophenoxy)-2,2'-bipyridine)ruthenium(II) hexafluorophosphate ([(Ru(bpy)(2)(dabpy)][PF(6)](2)), has been designed and synthesized as a highly sensitive and selective luminescence probe for the imaging of nitric oxide (NO) production in living cells. The complex can specifically react with NO in aqueous buffers under aerobic conditions to yield its triazole derivative with a high reaction rate constant at the 10(10) M(-1) s(-1) level; this reaction is accompanied by a remarkable increase of the luminescence quantum yield from 0.13 to 2.2 %. Compared with organic probes, the new Ru(II) complex probe shows the advantages of a large Stokes shift (>150 nm), water solubility, and a wide pH-availability range (pH independent at pH>5). In addition, it was found that the new probe could be easily transferred into both living animal cells and plant cells by the coincubation method, whereas the triazole derivative was cell-membrane impermeable. The probe was successfully used for luminescence-imaging detection of the exogenous NO in mouse macrophage cells and endogenous NO in gardenia cells. The results demonstrated the efficacy and advantages of the new probe for NO detection in living cells.