PubMed Health⌕ Search

Biomedical subjects

Zhi-min Chen

Publications and source records attributed to Zhi-min Chen.

10 recordsLinked to original sources
PubMed2005

[Viral etiology of pneumonia in children].

OBJECTIVE: To evaluate the viral pathogen of pneumonia in children. METHODS: A total of 13 642 cases of children pneumonia in 3 years were enrolled in this study. Antigens of viral pathogen in respiratory excretion, including respiratory syncytial virus (RSV), type 1, 2 and 3 parainfluenza virus, type A and B influenza virus, and adenovirus were detected by direct immunofluorescence method. RESULTS: Viral pneumonia accounted for 34.3% of all cases, including 25.8% cases of RSV, 4.7% of parainfluenza virus, 2.4% of type A influenza virus, 0.2% of type B influenza virus and 1.3% of adenovirus. Coinfection was found in 20 cases, in which 17 cases (85%) were infected with RSV and another virus. Positive rates of RSV in children < or = 1 year, 1 to 3 years, and >3 years were 33.1%, 19.7% and 5.1% with a significant difference (chi(2)(trend)=763.4, P < 0.001). The positive rate of adenovirus in children < or =1 year (0.7%) was significantly lower than that in children aged 1 to 3 years and in children >3 years (2.3% and 2.5%) (all P<0.01). The positive rate of type A influenza virus in children aged 1 to 3 years was higher than that in children < or =1 year (chi(2)=18.2, P<0.01). Type 1 parainfluenza virus was found in 1.2% children aged 1 to 3 years with most prevalence (P<0.05). Infection rates of type 3 parainfluenza in children < or =1 year, 1 to 3 years, and >3 years were 4.7%, 3.2% and 1.4% respectively with a significant difference (chi(2)(trend)=52.4, P<0.01). Although there were some differences of infection rate of RSV in different years, it tended to increase from November to next April with a highest rate of 62.8%. Type 3 parainfluenza virus and Type A influenza virus were almost sporadic while type A influenza virus was epidemic in August 2003 with an infection rate of 15.7%. CONCLUSION: The highest infection rate of viral pathogen of pneumonia in children is RSV and the follows are parainfluenza, influenza and adenovirus in turn.

Adenoviridae↗
PubMed2004

[Regulation of CD3, CD4 and CD8 expressions on PMA-activated human peripheral T cells].

OBJECTIVE: To investigate the effect of mitogen Phorbol 12-myristate 13-Acetate (PMA) on CD3, CD4 and CD8 expression of human T-lymphocytes. METHODS: Peripheral blood mononuclear cells from 37 blood samples stimulated in vitro with PMA at different concentrations (2,5,10,20 and 50 ng/ml for 4 hours) and time (10 ng/ml for 2,4 and 6 hours) were analyzed by 4-color flow cytometry (FCM). RESULTS: Under different PMA stimulation protocols,significant CD4 down-regulation was observed,which was negatively correlated with intracellular cytokine secretion (r= 0.601,P<.001), except for PMA stimulation at 10 ng/ml for 2-hours which showed no significant intracellular cytokine secretion. The expressions of CD3 and CD8 molecules after PMA activation were not significantly affected as compared with pre-activation. Among CD3 positive T lymphocytes, CD4/CD8 double-negative cells only account for 5.52%. CONCLUSION: PMA has a significant down-regulation effect on CD4 molecules of Th cells, without altering the CD3 and CD8 expression. For quantitative analysis of Th1/Th2 variation, indirect method such as CD3(+)CD8( ) T cells can be used to define CD4(+) Th cells stimulated by PMA in the future.

CD3 Complex↗
PubMed2004

[Antibiotics-resistance pattern and genetic type of Streptococcus pneumoniae isolated from children in Hangzhou].

OBJECTIVE: To investigate the antibiotics-resistance type and molecular epidemiology of Streptococcus pneumoniae isolated from children in Hangzhou. METHODS: The sensitivities of 323 strains of Streptococcus pneumoniae to 9 antibiotics were determined in vitro by Kirby-Bauer diffuse methods, and MICs of penicillin and cefotaxime were determined by E-test methods. RESULTS: Among all 323 strains isolated from children during the period from August 2001 to July 2002, 136 strains (42.1%) were sensitive to penicillin, while 57 strains (17.7%) were penicillin-resistant. Penicillin MICs ranged from 0.012 microg/ml to 4.0 microg/ml. All the strains were sensitive to cefotaxime and its MICs ranged from 0.012 microg/ml to 4.0 microg/ml. The most resistant antibiotic was erythromycin and it's resistant-rate was as high as 90.7%, followed by tetracycline (87.6%), trimethoprim-sulfamethoxazole (48.6%) and chloromycetin (14.9%). Totally 197 strains (61.0%) were multi-drug-resistant pneumococci and most of them were resistant to trimethoprim-sulfamethoxazole, erythromycin and tetracycline at the same time. Two strains (0.6%) were resistant to rifampin and none was resistant to vancomycin and ofloxacin. BOX PCR typing was carried out and no overwhelming fingerprinting pattern was found among penicillin resistant Streptococcus pneumoniae strains which were isolated from patients, while the banding patterns were always similar or identical among the strains isolated from the same specimen or from the same patient at different time, respectively. CONCLUSION: The antibiotics-resistant rate of pneumococci was high in Hangzhou, but the third-generation cephalosporins were still the best antibiotics against Streptococcus pneumoniae. One child could be infected or colonized by more than one pneumococci clone at the same or different time.

Anti-Bacterial Agents↗
PubMed2004

[Serotypes and antibiotics-resistance patterns of 247 strains of Haemophilus Influenzae isolated from children in Hangzhou].

OBJECTIVE: To investigate the serotypes and antibiotics-resistance patterns of Haemophilus influenzae isolated from children in Hangzhou. METHODS: Isolates were identified with api-NH card. Serotypes were determined with slide agglutination method. The sensitivities of 13 antibiotics against 247 strains of Haemophilus influenzae were determined in vitro with Kirby-Bauer diffusion methods and MICs of ampicillin were determined with E-test. Nitrocefin test was used to detect beta-lactamase. RESULTS: Of the 247 strains isolated from children during the period from August 2001 to July 2002, 153 strains were non-typable, while 94 strains (38.1%) were typable and 90.4% and 1.1% of them belonged to type d and type b, respectively. Higher incidence of typable Haemophilus influenzae was found in male than in female children and the difference was significant (chi(2) = 5.30, P < 0.05), while between upper and lower respiratory tract infected children the difference was not statistically significant (chi(2) = 3.60, P > 0.05). Forty-one isolates (16.6%) were beta-lactamase-positive and 14 strains could not grow on medium in antibiotics sensitivity test. Of all 233 isolates tested successfully, 85.4% were susceptible to ampicillin, and the sensitivity rate to cefaclor, ceftriaxone, cefotaxime, imipenem, rifampin, clarithromycin, and chloramphenicol were as high as 98.7%, 99.6%, 99.6%, 99.6%, 98.7%, 91.0%, and 90.6%, respectively. All strains were sensitive to amoxicillin/clavulanic acid, ampicillin/sulbactan and ofloxacin, while 107 strains (45.9%) were resistant to trimethoprim-sulfamethoxazole, followed by that of tetracycline (14.6%). Resistance to ampicillin and trimethoprim-sulfamethoxazole in typable isolates was statistically significantly higher than in non-typable strains. Twenty-six strains (10.5%) were multi-resistant isolates and the multi-resistance rate in beta-lactamase-positive strains were significantly higher than that in beta-lactamase-negative strains (chi(c)(2) = 146.8, P < 0.001). CONCLUSION: Non-typable Haemophilus influenzae was the most common type in clinical strains isolated from children in Hangzhou, while type d was the overwhelming type and type b was uncommon in typable isolates. Incidence of typable isolates was higher in male than in female children, and it was apt to intergrow with other species of pathogenic bacteria. The proportion of beta-lactamase-positive strains was not high and ampicillin or other beta-lactam actibiotics were still the treatment of choice for infections with Haemophilus influenzae.

Anti-Bacterial Agents↗
PubMed2002

[Colorectal exfoliated cell in stool and its nuclear DNA quantitative analysis for diagnosis of colorectal cancer].

BACKGROUND AND OBJECTIVES: Detection of colorectal exfoliated epithelial cells and their nuclear DNA content may provide another non-invasive way of screening and early diagnosis of colorectal cancer. This study was designed to analyze the roles of exfoliated cells in stool and its nuclear DNA content in diagnosis of colorectal cancer. METHODS: 1. One hundred and seventy nine individuals were selected, forty-six of them had pathological confirmation of colorectal carcinoma. The other 133 persons had no colonoscopic evidence of colorectal malignancy and therefore served as control. Exfoliated cells in the stool were isolated by elutriation, and the elutriation means was modified Iyengar's method. All individuals in the study had stool specimens for occult blood test(FOBT). 2. Nuclear DNA content and morphometric quantitative analysis in the exfoliated cells was performed on the 33 patients with colorectal cancer and 30 individuals served as control. The parameters selected in this study were DNA content, nuclear area, nuclear irregular index, and percent of > or = 5C cells. RESULTS: 1 Exfoliative cytology and FOBT: In 35 of 46 cases of colorectal malignancy(76.09%), cytology was positive: 5 cases demonstrated dysplastic cells, 4 cases indicated suspected carcinoma cells, 26 cases showed carcinoma cells. The positive rate of exfoliated cells had no significant relation to locations, sizes, histomorphologies, histological differentiations, Dukes stages, and lymph node metastases of the lesion(P > 0.05). Exfoliative cytology had a 98.50% (131/133) specificity for colorectal cancer in the study. The sensitivity for colorectal cancer was no significant difference between the two methods of exfoliative cytology and FOBT (76.09% vs 84.78%, P > 0.05), but the specificity for colorectal cancer, exfoliative cytology was significant higher than FOBT(98.50% vs 73.68%, P < 0.05). 2. DNA analysis of exfoliated cells nuclear, DNA content, nuclear area, nuclear irregular index and percent of > or = 5C cells in the stool were significant higher in colorectal cancer than in control group(P < 0.05). The percentage of > or = 5C cells were significantly associated with histological grade (P < 0.05). CONCLUSIONS: 1. Detection of exfoliated cells in stool plays an important role in diagnosis of colorectal cancer. Testing of FOBT and exfoliated cells sequentially hopes to be a new useful non-invasive test for screening of colorectal cancer. 2. DNA analysis of exfoliated cell in stool may provide an objective method of determining malignant grades and diagnosis of colorectal cancer.

Adult↗