OBJECTIVETo investigate the detection limit of multicolor combinational probe coding real-time PCR (MCPC-PCR) in detection of Salmonella and Staphylococcus aureus suspended in the food samples, and to apply MCPC-PCR to detect the samples of food poisoning.

METHODSSeries concentration of bacterium suspension (10(1) - 10(9) CFU/ml) was prepared by using 22 simulated samples including fresh meat and cakes and then MCPC-PCR was applied to detect Salmonella and Staphylococcus aureus in 22 samples. Enrichment broth of 101 frozen samples and 5 early patients' anal swabs in food poisoning cases were detected after the DNA samples were extracted.

RESULTSThe limits of MCPC-PCR assay in detecting Salmonella and Staphylococcus aureus were about 10(2) copies/test; 101 frozen enrichment broth of samples in food poisoning cases were detected by MCPC-PCR assay, of 23 positive samples, 18 were confirmed by bacteriology techniques; 96 samples detected by MCPC-PCR and bacteriology techniques had the same results, and the coincidence rate was 95.05%. Anal swabs, collected from 5 of early patients in a food poisoning case gave a clue to be Vibrio parahaemolyticus by MCPC-PCR assay and then were perfectly consistent with bacteriology assay.

CONCLUSIONAs a method of high sensitivity and good specificity, MCPC-PCR assay can quickly and conveniently detect multiple pathogens existing in food samples, therefore we recommend it to be used in rapidly screening or simultaneous detection of food-borne diseases.

Bacteriological Techniques ; methods ; Food Contamination ; analysis ; Food Microbiology ; Molecular Probe Techniques ; Molecular Sequence Data ; Polymerase Chain Reaction ; methods ; Salmonella ; genetics ; isolation & purification ; Sensitivity and Specificity ; Staphylococcus aureus ; genetics ; isolation & purification

The study was aimed to investigate the expression of HLA class I molecules and MHC class I chain-related molecules A/B (MICA/MICB) in K562 and adriamycin (ADM)-resistant K562 cell lines (K562/AO2) and their effect on cytotoxicity of NK cells. Expression of HLA class I molecules and MICA/MICB on the surface of K562 and K562/AO2 cell lines were analyzed by flow cytometry. Cytotoxicity of NK cells (isolated from 3 healthy persons) against K562 and K562/AO2 cells were detected by LDH releasing assay at different effect-to-target cell ratios (E:T). In blocking experiments, anti-MHC class I monoclonal antibody (McAb) (W6/32, a pan anti-HLA class I antibody) and anti-MHC class I chain-related molecules McAb (BAMO-1, specifically against MICA and MICB) were added to the target cells at E:T of 10:1. The results showed that the expression of MHC class I chain-related molecules on K562 was higher than that on K562/AO2 (P=0.000), and HLA class I molecules were not detectable on both cells. Cytotoxicities of NK cells against K562 and K562/AO2 cells were (29.32 +/- 0.12)%, (45.33 +/- 0.78)%, (58.37 +/- 0.87)%, (72.37 +/- 0.96)% and (12.47 +/- 0.91)%, (24.36 +/- 1.11)%, (33.29 +/- 1.03)%, (53.87 +/- 1.27)% at E:T ratios of 5:1, 10:1, 20:1 and 30:1 respectively (P=0.000), the cytotoxicity of NK cells on K562 cells was significantly higher than that on K562/A02 cells at different E:T ratios. Blocking experiments confirmed that at E:T of 10:1 killing of NK cells against K562 and K562/AO2 cells was efficiently inhibited by BAMO-1, whereas W6/32 had no effect on K562 and K562/AO2 cells. It is concluded that the expression of MHC class I chain-related molecules on K562 and K562/AO2 cells is correlated with NK cell-mediated lysis. NK cells display higher cytotoxicity against parental K562 cells than multi-drug resistant K562/AO2 cells. Down-regulation of MICA/B in multi-drug resistant tumor cell lines leads to reduction of susceptibility to NK lysis.
Cytotoxicity, Immunologic ; immunology ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; immunology ; Genes, MHC Class I ; genetics ; Histocompatibility Antigens Class I ; immunology ; Humans ; K562 Cells ; Killer Cells, Natural ; immunology

Objective To describe the prevalence and risk factors for suicide ideation among college students in Chongqing city. Methods Data on suicide ideation and related factors were collected from 9808 college students at 11 colleges randomly selected in Chongqing. A multiple logistic regression model was used to identify risk factors for suicide ideation. Results 1279 (13.0%) of the 9808 students reported suicide ideation and the constituent ratio of boys and girls was 3:4 whileriskfactors for suicide ideation were ranked as follows: high frequency of feeling hopeless in prior year (OR=5.07,95%CI: 4.27-6.02); having psychological problems in recent 1 month that affecting daily lives and learning(2.07,1.79-2.38); relatives having suicide behavior (1.77,1.52-2.08); having had sexual experience (1.95,1.65-2.30); being female (1.66,1.45-1.90) and friends who had had suicide attempts(1.46,1.28-1.67);having diseases in the last 1 month that affecting daily lives and learning (1.29,1.08-1.52). Conclusion The prevalence of suicide ideation among these college students was high that calls the development,implementation and assessment of suicide prevention plans for college students that focusing on the risk factors identified for suicide ideation.

OBJECTIVETo investigate the association between two polymorphisms of the APOC3 gene (T-455C and C-482T) and hereditary risk of non-alcoholic fatty liver disease (NAFLD).

METHODSA total of 287 patients with NAFLD and 310 control subjects were genotyped by PCR and direct sequencing. Serum lipid profiles were also detected by standard biochemical

METHODSOne-hundred-and-eighty of the study participants were used to measure the APOC3 content by enzyme-linked immunosorbent assay. Inter-group differences and associations were assessed statistically using Chi square and t tests and logistic and linear regression analyses.

RESULTSThe frequencies of neither the genotypes or alleles were significantly different between the NAFLD cases and the controls. Compared with the most common genotypes-455TT or-482CC, none of the variants showed a significant increase in risk of NAFLD or for the clinical and biochemical parameters. The adjusted odds ratios (with 95% confidence intervals) of NAFLD were 1.25 (0.79-1.96) and 1.20 (0.76-1.89) for carriers of the APOC3-455C and-482 T variants respectively (P more than 0.05).

CONCLUSIONThe T-455C and C-482T polymorphisms of the APOC3 gene are not associated with risk of NAFLD, pathogenic changes in lipid profiles, or insulin resistance in Han Chinese.

Adult ; Aged ; Alleles ; Apolipoprotein C-III ; genetics ; Case-Control Studies ; Female ; Gene Frequency ; Genotype ; Humans ; Insulin Resistance ; Lipids ; blood ; Male ; Middle Aged ; Non-alcoholic Fatty Liver Disease ; genetics ; metabolism ; Polymorphism, Single Nucleotide ; Promoter Regions, Genetic ; Young Adult

OBJECTIVETo study the associations of CYP1A1 gene polymorphisms with levels of urinary 1-hydroxypyrene among coke oven workers.

METHODS223 male workers from a coke plant (76, 82 and 65 workers in oven top group, oven-side group and oven-bottom group respectively) and 119 controls without occupational polycyclic aromatic hydrocarbons exposure were selected. The MspI gene polymorphism in CYP1A1 3' flanking region and the genotypes at I462V site in exon 7 of CYP1A1 were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific amplification (ASA).

RESULTSThe urinary 1-hydroxypyrene of coke oven workers in oven-top, oven-side and oven-bottom (3.77+/-0.64, 3.57+/-0.49, 3.26+/-0.80 micromol/mol Cr) were significantly higher than controls (2.80+/-1.02 micromol/mol Cr) (P<0.01). The urinary 1-hydroxypyrene was not significantly different among MspI genotypes in CYP1A1 3' flanking region (P>0.05). In oven-top group and oven-side group, the subjects with Val/Val genotype in exon 7 of CYP1A1 had significantly higher urinary 1-hydroxypyrene levels than those with Ile/Val or Ile/Ile genotype, and urinary 1-hydroxypyrene of Ile-Val genotype were also significantly higher than Ile/Ile genotype (P<0.01). Multivariate logistic regression analysis showed that the coke oven workers (OR in oven top group, oven-side group and oven-bottom group was 24.926, 4.226 and 6.729 respectively) and subjects with m2/m2 genotype in CYP1A1 3' flanking region (OR=4.031) or with Val/Val or Ile/Val genotype in exon 7 of CYP1A1 (OR were 5.524 and 3.811) had elevated urinary 1-hydroxypyrene (greater than 95 percentile of control group, 3.876 micromol/mol Cr).

CONCLUSIONBAP concentration of work environment contributes to the elevated urinary 1-hydroxypyrene levels, and the exposed BAP levels were regulated by the CYP1A1 MspI and I462V genotypes. Genetic polymorphism of CYP1A1 gene could be a susceptible biomarker in coke oven workers which was involved in the individual susceptibility on metabolism of PAHs.

Adult ; Benzo(a)pyrene ; adverse effects ; Coke ; Cytochrome P-450 CYP1A1 ; genetics ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Polymorphism, Genetic ; Pyrenes ; pharmacokinetics ; Urine ; chemistry

Objective To investigate the prevalence and related factors of peritoneal calcification in peritoneal dialysis(PD)patients with long dialysis duration,and to explore the relationship between peritoneal calcification and vascular calcification.Methods This cross-section study enrolled PD patients who had received PD for more than 4 years in Peking University People's Hospital.Peritoneal calcification and abdominal aortic calcification were reviewed by CT scan.Demographic data,clinical characteristics,laboratory data including calcium phosphorus metabolism indexes(Ca,P,ALP and iPTH)and PD adequacy were collected.The influencing factors of peritoneal calcification were analyzed by Logistic regression analysis.The correlation between peritoneal calcification and abdominal aortic calcification were tested by Spearman correlation analysis.SPSS 19.0 was used for statistical analysis.Results(1)Seventy-nine PD patients were enrolled:32 males(40.5％);mean age was(58.7±13.1)years and average PD duration was 77.25(58.00,88.00)months.The major primary diseases were glomerulonephritis(46.8％)and diabetic nephropathy(30.4％).(2)6 patients(7.6％)had CT-detectable peritoneal calcification.77(97.5％)patients were found with various degrees of peritoneal thickening.The prevalence of peritoneal calcification was 7.6％in patients with PD duration more than 4 years,10.3％in patients with PD duration more than 6 years,18.8％in patients with PD duration more than 8 years and 40.0％in patients with PD duration more than 10 years,showing an increasing trend.Compared with non-peritoneal calcification group,the patients in peritoneal calcification group received higher doses of Vitamin D(P ＜ 0.001)and lower triglyceride levels(P=0.041).The patients were divided into two groups according to whether dialysis duration was longer than 9 years,and the proportion of patients with long PD duration in peritoneal calcification group was higher(P=0.013).Logistic regression analysis showed that PD duration,calcium and phosphorus metabolism indexes were not independent risk factors of peritoneal calcification.High vitamin D dose was an independent risk factor for peritoneal calcification(B=2.667,OR=14.394,95％CI 1.655-125.165,P=0.016).(3)74 patients were found with abdominal aortic calcification in different degrees,and the prevalence rate of abdominal aortic calcification was 93.7％.Spearman correlation analysis showed that there was no correlation between peritoneal calcification and vascular calcification(r=0.70,P=0.542).Conclusions The prevalence of peritoneal calcification in long PD duration patients is low.Peritoneal calcification may be associated with high Vitamin D dose and long PD duration.

Objective To investigate the prevalence of self-reported suicidal behavior in university students and to compare the related risk factors between two selected groups. Methods A questionnaire survey on situation of suicidal behavior and risk factors was conducted among 9808 university students. Results The overall rate of suicide attempts among university students was 1.7%. Factors as suicidal attitude, having associates who had suicidal experience and negative life events, were significantly different between groups with or without suicide attempts. Risk factors on suicidal behavior were as follows: high frequency of feeling hopeless in the last year (OR=4.23,95% CI: 3.05-5.85) , first degree relatives with suicide behavior (OR=2.85, 95% CI: 1.72-4.73),having associates with suicide behavior (OR=2.82,95%CI: 2.05-3.88), having had sexual experience (OR=2.73,95%CI: 1.88-3.96), daily live being influenced by the existing psychological problems in the last month (OR=2.53, 95% CI: 1.80-3.56) , being female (OR=2.47, 95% CI: 1.77-3.45) and having other relatives with suicide behaviors (OR=2.36, 95% CI: 1.63-3.41). Conclusion Psychological, biological and social factors had influenced on suicidal behaviors among university students which all called for effective intervention to be implemented.

The study was purposed to explore the molecular mechanisms of sodium butyrate (NaB) action on SKM-1 cell proliferation/differentiation and to study its synergistic effect with all-trans retinoic acid (ATRA). SKM-1 cells were grown in the absence or presence of NaB and/or ATRA; the percentage of viable cells was determined by trypan blue exclusion; differentiation was investigated by nitro-blue tetrazolium (NBT) reduction; adhesion molecules of cell surface were analysed by FACS; cell cycle distribution was studied after DNA staining by propidium iodide; D-type cyclins, CDK and P21 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that NaB and/or ATRA blocked cells mainly in the G0/G1 phase of the cell cycle; ATRA inhibited the mRNA expression of CDK6, CDK4, cyclin D3 and cyclin D1; NaB inhibited the mRNA expression of CDK2, cyclin D2 and cyclin D1; ATRA and NaB inhibited the mRNA expression of CDK6, CDK4, CDK2, cyclin D1, cyclin D2 and cyclin D3; ATRA and/or NaB both stimulated p21 expression at the mRNA levels. It is concluded that the NaB effect on cell proliferation/differentiation may be linked to its ability to induce expression of p21 mRNA and inhibit the cyclin D-CDK complexes. These observations support the claim that NaB has the synergistic effect with ATRA.
Aged ; Butyrates ; pharmacology ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; genetics ; Cell Differentiation ; drug effects ; Cell Line ; Cell Proliferation ; drug effects ; Cyclin D ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; genetics ; Humans ; Male ; Myelodysplastic Syndromes ; pathology ; Reverse Transcriptase Polymerase Chain Reaction ; Tretinoin ; pharmacology

OBJECTIVETo develop a quantitative real-time polymerase chain reaction (PCR) for detecting Rickettsia prowazekii.

METHODSPrimers and TaqMan-MGB probes designed based on ompB gene of R. prowazekii, were used to develop this method.

RESULTSFor the quantitative real-time PCR, the relationship between the values of threshold cycle (Ct) and the DNA copy number was linear (r = 0.999) and the sensitivity was about 100 times higher than that of the nested PCR for detecting the same DNA sample. The results of the genomic DNA samples of other rickettsial and bacterial agents detected by real-time PCR were all negative. DNAs extracted from blood samples of guinea pig infected with R. prowazekii were examined by real-time PCR and the positive results were obtained from some of these samples. However, the results of some samples in nested PCR assay were all negative.

CONCLUSIONThese results suggested that the real-time PCR was highly specific and sensitive for detection of R. prowazekii that was useful for the detection of tiny DNA of R. prowazekii in blood samples from patients suspected of having epidemic typhus.

DNA Primers ; DNA, Bacterial ; analysis ; Humans ; Polymerase Chain Reaction ; methods ; Rickettsia prowazekii ; genetics ; isolation & purification ; Sensitivity and Specificity ; Typhus, Epidemic Louse-Borne ; diagnosis

BACKGROUNDPulmonary artery sling (PAS) is a rare congenital heart anomaly and may cause unexplained respiratory symptoms in infants. Since the non-specific respiratory symptoms of PAS may lead to misdiagnosis, the aim of this study was to clarify the clinical and imaging features of this disease for timely diagnosis and treatment.

METHODSClinical histories, physical examinations and imaging studies were retrospectively evaluated in nine infants with PAS. Chest X-ray, echocardiography and contrast-enhanced computed tomography (CT) with 3-dimensional reconstructions were performed in all patients and three of them received surgical treatment.

RESULTSNine cases included six males and three females with a mean age of (4.3 ± 2.8) months ranging from 2 to 11 months old. All patients had respiratory symptoms including recurrent cough, stridor and wheezing. The onset of symptoms was within 3 months in all cases and three children had symptoms only a few days after birth. The chest X-ray showed pneumonia in all cases. Contrast-enhanced CT showed the tracheal compression at different lengths in every case. The echocardiograph findings of PAS were anomalous origins of the left pulmonary artery from the posterior aspect of the right pulmonary artery. Of the 9 cases, 8 cases were diagnosed correctly by echocardiography. Of the complicated abnormalities, there were one with secundum atrial septal defect, one with patent foramen ovale and three with persistent left superior vena cava. None of them were complicated with significant blood dynamic changes.

CONCLUSIONSInfants with recurrent respiratory symptoms such as chronic cough, stridor and wheezing, should be examined for the possible presence of congenital pulmonary artery sling. As a noninvasive technique, echocardiography is very helpful and should be the first-choice modality for the diagnosis of pulmonary artery sling. Contrast-enhanced CT, clearly demonstrating the anatomy of pulmonary artery sling and the position and extent of trachea compression, is necessary for the final diagnosis and pre-operation evaluation.

Echocardiography ; Female ; Heart Defects, Congenital ; diagnosis ; diagnostic imaging ; physiopathology ; Hemodynamics ; physiology ; Humans ; Infant ; Male ; Pulmonary Artery ; abnormalities ; diagnostic imaging ; physiopathology ; Radiography