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Biomedical subjects

Yu Ma

Publications and source records attributed to Yu Ma.

At least 37 records · Page 2Linked to original sources
PubMed2005

[The in-vitro interferon-gamma release assay for the diagnosis of tuberculosis and Mycobacterium tuberculosis infections].

OBJECTIVE: To investigate the in-vitro interferon-gamma (IFN-gamma) release assay based on three different Mycobacterium tuberculosis antigens in the diagnosis of tuberculosis and Mycobacterium tuberculosis infections. METHODS: The peripheral blood mononuclear cells (PBMC) were collected from the patients with tuberculosis (tuberculosis group, n = 57), patients with lung cancer (lung cancer group, n = 29), and healthy controls (healthy control group 2, n = 27). The PBMCs were co-cultured for 5 days with different antigens: purified protein derivatives (PPD) of tuberculin, early secretary antigenic target 6,000 protein (ESAT6) and 38,000 antigen. The protein levels of IFN-gamma were detected by ELISA, and the results were compared to those with the tuberculin skin test (TST). RESULTS: (1) For healthy controls, the TST was positively related to the history of BCG vaccination and the closeness of contact with sputum-positive tuberculosis patients (P = 0.047, P = 0.041 respectively). The ESAT6 based IFN-gamma release assay was only significantly related to the closeness of contact with sputum-positive tuberculosis patients (P = 0.005), but not to the history of BCG vaccination. (2) There was no significant difference of the TST results among the three groups (P > 0.05). (3) The receiver operating characteristic (ROC) curve analysis indicated that the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the IFN-gamma release assay based on 38,000 antigen were 64.9%, 89.3%, 77.0%, 86.0%, and 71.0% respectively for the diagnosis of tuberculosis. CONCLUSIONS: IFN-gamma release assay based on ESAT6 appears to be better than TST in the diagnosis of infection of Mycobacterium tuberculosis, while IFN-gamma release assay based on 38,000 may be helpful for the diagnosis of tuberculosis.

Adult↗
PubMed2005

[Correlation between the mRNA levels of carcinoembryonic antigen and cytokeratin 19 in peripheral blood with staging, treatment response and prognosis in patients with lung cancer].

OBJECTIVE: To investigate the expression of carcinoembryonic antigen (CEA) and cytokeratin19 (CK19) mRNAs in peripheral blood of patients with lung cancer and their correlation with staging, treatment response and prognosis. METHODS: CEA and CK19 mRNAs in peripheral blood were detected by Taq Man reverse transcriptase-polymerase chain reaction (RT-PCR) in 78 patients with lung cancer before and after treatment, 30 patients with benign lung diseases and 30 healthy subjects. Serum CEA and CYFRA21-1 levels were also measured by enzyme linked immunosorbent assay (ELISA) in the 78 patients with lung cancer before treatment. The patients were followed for 2 years. RESULTS: The positive rates of CEA mRNA and CK19 mRNA in patients with lung cancer were 69.2% (54/78) and 62.8% (49/78), respectively, which were significantly higher than those in patients with benign lung diseases and the healthy controls (P < 0.01). The positive rate of CEA mRNA was the highest in adenocarcinoma, while the positive rate of CK19 mRNA was the highest in squamous cell carcinoma. There was no statistically significant difference among different stages (P > 0.05), The positive rates of CEA mRNA and CK19 mRNA were higher than those of serum CEA and CYFRA21-1. The positive rates of CEA mRNA and CK19 mRNA decreased significantly after surgical operation, but there was no significant change after chemotherapy. The median survival time (MST) for patients with a positive CEA mRNA before chemotherapy was shorter than those with a negative CEA mRNA (8.5 month and 11.7 month, respectively). The MST for patients with a positive CK19 mRNA before chemotherapy was shorter than those with a negative CK19 mRNA (8.9 month and 12.3 month, respectively). The rate of relapse and metastasis was higher in patients (29.4%) with a positive CEA mRNA preoperatively than those with a negative CEA mRNA (7.7%). The rate of relapse and metastasis was also higher in patients with a positive CK19 mRNA preoperatively (18.8%) as compared to those with a negative PCR result (7.1%). CONCLUSIONS: CEA and CK19 mRNAs can be used as markers in the detection of tumor micrometastases in lung cancer, and in evaluating surgical response and prognosis. The results suggest that the gene markers are better than the serum ones, and therefore may be useful for the early diagnosis of lung cancer.

Adult↗
PubMed2005

[Polymerase chain reaction-single strand conformation polymorphism analysis combined with nucleic acid hybridization to detect ofloxacin-resistant Mycobacterium tuberculosis mutation selected in vitro].

OBJECTIVE: To explore the feasibility of utilizing polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis combined with Southern blot to detect ofloxacin (OFLX)-resistant Mycobacterium tuberculosis, and figure out the boundary between the OFLX-susceptible and resistant Mycobacterium tuberculosis. METHODS: OFLX-resistant Mycobacterium tuberculosis bacilli were induced in vitro and their minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) were determined. The 320 bp segments of gyrA gene were amplified by PCR and their polymorphism was tested by SSCP from H(37)Rv, H(37)Ra and those induced OFLX-resistant strains. To prove the repeatability of PCR-SSCP combined with Southern blot, 36 clinical isolated OFLX-resistant strains were tested. RESULTS: All of the 85 OFLX-resistant mutations involved in this study were identified to have gyrA mutations. The results showed that there was an overlap if OFLX 10 microg/ml was used as a criteria for discriminating susceptible and resistant strains. Compared with the H(37)Ra, the similar single-stranded shift caused by the single-stranded conformation change was viewed in the 36 clinical isolated OFLX-resistant strains by PCR-SSCP combined with Southern hybridization. CONCLUSIONS: PCR-SSCP analysis combined with Southern blot can clearly distinguish OFLX-susceptible from OFLX-resistant strains. The results suggest that as a cut-off point between OFLX-susceptible and low-level OFLX-resistant to Mycobacterium tuberculosis, OFLX concentration of 10 microg/ml is considered to be a better one.

Antitubercular Agents↗
PubMed2004

[A preliminary study on the definition of resistant breakpoints of ofloxacin and levofloxacin for Mycobacterium tuberculosis].

OBJECTIVE: To test the MIC of ofloxacin and levofloxacin (MIC(F) and MIC(V)) in 101 strains of Mycobacterium tuberculosis (M. tb) isolated from patients with active tuberculosis and to analyze the relation between MIC and past history of fluoroquinolones (FQs) administration. And according to the analysis of the therapeutic effect of the regimen including FQs, we want to define the resistant breakpoints of OFLX and LVFX clinically. METHOD: All isolates from sputa or pus obtained from in-patients in our hospital from Jan 1999 to Sept 2000 were tested for MIC and susceptibility. 47 patients with pulmonary tuberculosis received regimens including FQs were observed consecutively. Chi-square test was applied for the statistical analysis. RESULT: (1) The MIC(V) of 96% clinical isolates tested were 2 times lower than MIC(F). (2) The MIC(F) < 8 microg/ml and MIC(V) < 4 microg/ml were found among 91% and 92% patients without previous FQs administration, while only the MIC(F) > or = 8 microg/ml and MIC(V) > or = 4 microg/ml were found among 54% and 57% for the patients with FQs administration history. (3) If MIC(F) > or = 8 microg/ml and MIC(V) > or = 4 microg/ml were defined as the clinical resistant breakpoints, in susceptible group, the sputum negative conversion rates were 54%, 75% and 82% respectively after receiving the regimens including FQs in 3, 6, and 12 months, while 16%, 32%, and 42% respectively in resistant group, (P < 0.01). Also, there were significant differences between these two groups for chest X-ray improvements after 12 months' treatment, (P < 0.01). There were significant differences for sputum conversion rates and chest X-ray improvement between MIC(V) < 4 microg/ml and MIC(V) > or = 4 microg/ml groups (P < 0.01). CONCLUSIONS: According to the evaluation for the therapeutic effects of regimens including FQs, it is suggested that MIC(F) > or = 8 microg/ml and MIC(V) > or = 4 microg/ml be defined as resistant breakpoints clinically. The emergence of resistance to FQs in patients with tuberculosis can influence the therapeutic effects.

Adolescent↗
PubMed2004

[Study on gene knock-out in Mycobacterium BCG].

OBJECTIVE: To establish the methodology of plasmid for gene knock-out in Mycobacterium BCG. METHODS: We designed two pairs of primers for amplification of MDP1 gene and inserted two fragments into pKO plasmid, and then the recombinant plasmid for MDP1 gene knock-out was obtained, and named pKO-MDP1. Gene exchange took place within the genome of BCG after pKO-MDP1 plasmid was transformed into Mycobacterium BCG. The strain of Mycobacterium BCG with MDP1 gene knock-out was selected, and the curve of growth rate was studied. RESULTS: The target strain was that of the positive strain by two step PCR and one step sucrose counter selection, without growth in culture media with hygomycin. The value of A(600) per 12 hours was detected for sixteen days. A "S" shaped growth curve was detected. However, there was no significant difference in the growth rates between the wild type Mycobacterium BCG strain and the gene knock-out Mycobacterium BCG strain. CONCLUSIONS: The plasmid of pKO was a useful tool for gene knock-out in Mycobacteria. MDP1 maybe one of the factors influencing the growth rate, but it was not the only one.

BCG Vaccine↗
PubMed2004

[Analysis and evaluation of phage amplified biologically assay, DNA sequencing analysis and single-strand conformational polymorphism for the drug susceptibility testing of Mycobacterium tuberculosis].

OBJECTIVE: To rapidly identify drug-resistant Mycobacterium tuberculosis using phenotypic and genotypic methods and to evaluate the clinical significance of rapid phenotypic susceptibility test by phage amplified biologically assay (PhaB). METHODS: PhaB, DNA sequencing and polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) were performed on the 91 rifampicin (RFP)-resistant strains (including 82 multi-drug resistant Mycobacterium tuberculosis strains), 42 RFP-susceptible strains, 75 ofloxacin (OFLX)-resistant strains and 40 OFLX-susceptible strains at the same time. RESULTS: The results obtained using PhaB assay, DNA sequencing and PCR-SSCP were compared with the absolute concentration method. For RFP susceptibility, the accordance, sensitivity and specificity of PhaB were 93%, 92% and 95% respectively; the accordance, sensitivity and specificity of DNA sequencing were 93%, 90% and 100% respectively; those of PCR-SSCP were 90%, 86% and 100% respectively. For OFLX susceptibility, the accordance, sensitivity and specificity of PhaB assay were 95%, 95% and 95%; those of DNA sequencing were 80%, 71% and 98% respectively; those of PCR-SSCP were 75%, 63% and 98% respectively. CONCLUSIONS: PhaB assay is a low-cost, rapid, and sensitive method and shows high accordance with absolute concentration technology. It can give drug susceptibility test results within 48 - 96 h, and is a promising technology in clinical laboratory.

Antibiotics, Antitubercular↗
PubMed2004

[Analysis of the effect of surgical management on vitreomacular traction syndrome].

OBJECTIVE: To evaluate the efficacy of vitreous surgery for the patients with vitreomacular traction syndrome. METHODS: The 16 consecutive patients (16 eyes) who underwent vitrectomy for vitreomacular traction syndrome during July 1998 and January 2002 were retrospectively analyzed. RESULTS: Vitreomacular traction was released successfully after vitrectomy, a better visual acuity was obtained in 10 eyes, the number of patients whose visual acuity was below 0.1 was increased from 6 to 8. In 5 cases with the visual acuity was 0.02 or worse before surgery, however their visual acuity was improved in some degree. Complications of vitreous surgery included iatrogenic macular hole (2 eyes), postoperative cataract in (1 eye), partial-thickness macular hole (1 eye), and macular pucker (1 eye), both of last two complications was demonstrated three months later. CONCLUSION: Pars plana vitrectomy can relieve macular traction, improve visual acuity and prevent a further decease of visual acuity.

Adult↗
PubMed2003

[Prevalence of allergic respiratory disorders and skin prick test in Beijing urban and suburban children: a comparative study].

OBJECTIVE: To investigate the prevalence of allergic respiratory disorders and allergens in Beijing urban and suburban children. METHODS: Using the International Study of Asthma and Allergies in Childhood Phase III Protocol, a questionnaire survey was conducted among 7,077 junior middle school students, 3,531 males and 3,546 females, aged 13-14, of 11 urban schools and 10 suburban schools in Beijing by random cluster sampling. Skin prick test with 13 common allergens was conducted among 2,126 from the 7,077 students by random cluster sampling. RESULTS: The prevalence rates of anamnestic asthma, asthma in recent 12 months, asthma after exercise in recent 12 months, and dry cough during night in recent 12 months were 12.4%, 7.2%, 25.6%, and 19.3% respectively in the urban students; all significantly higher than those in the suburban students (4.5%, 4.3%, 12.5%, and 8.3% respectively, all P < 0.01). The rates of anamnestic nasal symptoms without common cold, present nasal symptoms without common cold, and those nasal symptoms complicated with itching eyes and lacrimation were 41.6%, 35.6%, and 10.3% respectively in urban students, and 21.3% all significantly higher than those in the suburban students (21.3%, 12.3%, and 3.3% respectively, all P < 0.05). The positive rates of the 13 main allergens were significantly higher in the urban students than in the suburban students (all P < 0.01). The positive rate of Dermatophagoides farinae and D. pteronyssinus, cat hair, and Blatella germanica were 20.4%, 16.9%, 10.8%, and 11.0% respectively in the urban students, all significantly higher than those in the suburban students (3.7%, 2.7%, 3.7%, and 2.7% respectively, all P < 0.01). CONCLUSION: The prevalence rates of allergic disorders have been increased in comparison with those in the last decade in Beijing junior middle school students, especially those in the urban area and may be due to the changes of environments and living styles.

Adolescent↗
PubMed2003

[Elimination of methylene blue in plasma by use of adsorbents].

The adsorption of methylene blue (MB) in plasma on cross-linked agarose beads entrapped activated charcoal (CAAC-I), cross-linked agarose coated activated charcoal (CAAC-II) and cross-linked agar beads entrapped attapulgite (CAA) was tested in this study. These adsorbents are intended to be applied to blood purification for eliminating MB from virucidal MB-phototrated plasma units. The experimental results indicated that the adsorption of MB in plasma on CAAC-I and CAA was quick and efficacious, but it was slower on CAAC-II. The relationship between the adsorption time and the adsorption rate was examined with reference to the plasma with a specific concentration of MB flowing over a certain volume of CAA. A flow rate of about 1 ml.min-1 through 10 ml CAA at 25 degrees C could eliminate more than 95% of the MB in 200 ml human plasma (1 mumol.L-1).

Adsorption↗
PubMed2003

[Change of leukocytic phagocytosis during repeat hemoperfusion with cross-linked agar beads entrapped attapulgite clay].

The leukocytic phagocytosis rate and the index of phagocytosis of rats on cross-linked agar beads entrapped attapulgite clay (CAA) hemoperfusion were studied. The results revealed that the leukocytic phagocytosis rate and the index of phagocytosis descended significantly after 1 hour and rose gradually after 6 hours. Finally it reached the normal level after 48 hours. Hemoperfusion repeated two times gave similar results. In conclusion, the function of leukocytic phagocytosis declined temporarily during CAA hemoperfusion. Many times hemoperfusion will not notably affect the body's defense system of rats.

Agar↗
PubMed2003

[Effects of the adsorbent CAA for hemopurification on normal components of human plasma in removing methylene blue].

Virus inactivation of plasma can be achieved by phototreatment with methylene blue (MB). Subsequently, elimination of MB may reduce the adverse effects of MB. This study examined the effects of adsorbing MB with the use of cross-linked agar bead entrapped attapulgite clay (CAA) on normal ingredients in MB-treated plasma units. The biomedical characteristics of CAA were assessed by determination of partial biochemical indexes, coagulation potency and some cationic concentration in a control sample and the MB-treated plasma eluted from CAA column. The biochemistry indexes or K+, Na+ in plasma were almost unaltered before and after CAA adsorption. In contrast, the concentrations of CA2+ and Mg2+ increased and the blood ammonium decreased obviously. The activated partial thromboplastin time (APTT) was prolonged from 42 s to 53 s, and prothrombin time (PT) from 13 s to 14 s. The result indicates that CAA as an adsorbent for hemopurification retains the most important characters of human plasma. CAA can be useful for the elimination of MB in MB-treated plasma and does not bring on harmful alteration in clinical significance.

Adsorption↗
PubMed2003

[A study on the association of 3'UTR polymorphisms of NRAMP1 gene with susceptibility to tuberculosis in Hans].

OBJECTIVE: To determine whether 3'UTR polymorphisms of the NRAMP1 gene are associated with tuberculosis in Hans. METHODS: 3'UTR polymorphisms of NRAMP1 gene were typed by PCR-RFLP among 147 patients with active tuberculosis and 145 healthy individuals. The relationship between 3'UTR polymorphisms and susceptibility to tuberculosis was studied, and cases were grouped according to genotypes. RESULTS: In the tuberculosis patients, genotype TGTG/TGTG, TGTG/TGTG deleted, and TGTG deleted/TGTG deleted were observed in 95, 50 and 2 cases respectively, while the genotypes of the healthy controls were TGTG/TGTG in 115, TGTG/TGTG deleted in 29 and TGTG deleted/TGTG deleted in 1 case. The frequency of the genotype TGTG/TGTG was found more often among controls than that in patients (chi(2) = 7.79, P < 0.01). The frequency of allele TGTG and the frequency of variant allele were 0.85 and 0.15 respectively. CONCLUSIONS: 3'UTR polymorphisms of NRAMP1 gene are associated with susceptibility to tuberculosis in Hans. The variant allele observed in Hans is more common than that in Caucasians. These observations might explain in part why Hans have greater susceptibility to tuberculosis than Caucasians.

Adult↗
PubMed2003

[Nitric oxide production and expression of cytokines by macrophages infected by M. tuberculosis H(37)R(v)].

OBJECTIVE: To study nitric oxide (NO) production and cytokine expression by macrophages infected by M. tuberculosis H(37)R(v), and to compare the difference between dead and live M. tuberculosis in the induction of immune responses, and thus to show if dead bacteria could be a possible candidate for new vaccines. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and ELISA were used to measure the production of NO and cytokines in macrophages infected by H(37)R(v). RESULTS: Macrophages infected by viable M. tuberculosis produced more NO, IL-1, IL-12, IL-18, TNF-alpha and inducible nitric oxide synthases (iNOS), as compared with macrophages infected by dead bacteria. The number of bacteria was also an important factor determining the production of NO and cytokines. CONCLUSIONS: Viable M. tuberculosis H(37)R(v) can induce the activation of macrophages and the production of more NO and cytokines which play important roles in the host immune response. Heat-killed M. tuberculosis H(37)R(v) failed to induce activation of macrophages and the production of NO and cytokines, which makes it unlikely to be a candidate for vaccine development.

Cells, Cultured↗
PubMed2003

[Relationships between the diameters of Bacille Calmette-Guerin scars and asthma, atopy in urban and rural Beijing children].

OBJECTIVE: To compare the diameters of Bacille Calmette-Guerin (BCG) scars between asthmatic (allergic) students and normal students, and to compare the diameters of BCG scars in children in rural Beijing area with those in urban Beijing area, and to compare the prevalence of asthmatic (allergic) symptoms and atopy between rural and urban Beijing students. METHODS: Sampled by cluster-random Method, 819 urban school children and 1 044 rural school children aged 13 - 14 years were recruited for the Beijing arm of the phase III international study of asthma and allergies in childhood. The children answered the core questionnaires, and underwent skin prick test for 13 allergens, and were checked for BCG scars on their arms. RESULTS: (1) In both rural and urban Beijing students, the mean diameters of BCG scars in those with asthma (allergy) (asthma ever, wheeze ever, current wheeze within 12 months, hay fever ever, repeated rash ever, eczema ever, allergic rhinitis, atopy, high-sensitivity or were diagnosed asthma) were (7.0 +/- 2.1) mm-(8.8 +/- 2.8) mm, which were not significantly different from those of (7.2 +/- 2.7) mm-(8.2 +/- 2.2) mm in normal students (P > 0.05). (2) Compared to the urban students, the mean diameter of BCG scars in the rural students was (8.2 +/- 2.3) mm, significantly larger than that of (7.3 +/- 2.9) mm in the urban students (P < 0.01). The prevalence of asthma (allergy) (asthma ever, wheeze ever, current wheeze within 12 months, hay fever ever, repeated rash ever, eczema ever, allergic rhinitis, atopy, high-sensitivity or diagnosed asthma) were 0.6% - 11.4% in the rural Beijing students, significantly lower than that of 3.1% - 35.7% in urban Beijing schoolchildren (P < 0.01). CONCLUSIONS: The diameters of BCG scars were not significantly different between asthmatic (allergic) students and normal students. The diameters of BCG scars in the rural students were significantly larger than those in the urban students. The prevalence of asthma and allergy in the rural children were significantly lower than that in the urban students. The results suggest that there is difference in immunity between rural and urban children from early life, which may be caused by the different living environments.

Adolescent↗
PubMed2003

[Individual allergens as risk factors for asthma and bronchial hyperresponsiveness in Chinese children].

OBJECTIVE This study aimed to determine the relationship between individual allergens with current wheezing and bronchial hyperresponsiveness (BHR) in schoolchildren from three chinese cities: Beijing, Guangzhou and Hong Kong. METHODS Community-based random samples of 10-yr-old schoolchildren from the 3 cities were recruited for study using the International Study of Asthma and Allergies in Childhood (ISAAC) Phase II protocol. The subjects were studied by parental questionnaires (n = 10,902), skin-prick tests (n = 3478), and methacholine challenge tests (n = 608). RESULTS The highest prevalence rates of wheezing in the past 12 months (Beijing, 3.8%; Guangzhou, 3.4%; Hong Kong, 5.8%) and atopy (Beijing, 23.9%; Guangzhou, 30.8%; Hong Kong, 41.2%, defined as having <or= 1 positive skin-prick tests,) were seen in schoolchildren from Hong Kong. The highest prevalence rates of BHR (Beijing, 33.2%; Guangzhou, 45.8%; Hong Kong, 30.7%) were seen in schoolchildren from Guangzhou. Multivariate-logistic regression analyses revealed that sensitization to Dermatophagoides pteronyssinus [odds ratio ((OR)) = 4.48; 95% confidence interval ((CI)); 3.02-6.66], cat ((OR) 2.85; 95% (CI) 1.24-6.50), Dermatophagoides farinae (DF) ((OR) 2.41, 95% (CI) 1.65-3.51) and Mixed grass pollen ((OR) 2.85, 95% (CI) 1.24-6.50) were significantly associate with current wheezing atopy ((OR) 1.29, 95% (CI) 0.74-2.24), was not an independent risk factor for current wheezing in children from any of the three cities. Furthermore, atopy ((OR) 2.53, 95% (CI) 1.93-6.97) were significantly associated with BHR. CONCLUSION The authors confirmed that sensitization to house dust mite and cat was significantly associated with current wheezing and bronchial hyperresponsiveness in Chinese schoolchildren.

Allergens↗
PubMed2002

Characterization of rpoB mutations in rifampicin-resistant Mycobacterium tuberculosis isolated in China.

The objective of this study was for the elucidation of the characteristics of the rpoB gene mutation in rifampicin (RIF)-resistant Mycobacterium tuberculosis strains isolated in China. The rifampicin resistance determination regions (RRDR) of the rpoB genes of 242 M. tuberculosis strains were sequenced, including 193 RIF-resistant, 46 RIF-sensitive clinical isolates and three manually induced RIF-resistant tuberculosis strains. Mutations in the 81 bp RRDR of the rpoB gene were identified in 89.6% (173/193) of RIF-resistant clinical isolates. No mutation was observed in RIF-sensitive strains. Ser531Leu mutations accounted for 46.1% (89/193) of RIF-resistant strains; the mutation frequency of 526-His was 17.6% (34/193) in RIF-resistant strains. Furthermore, a combination of 2-3 single-point mutations was observed in 24 RIF-resistant strains (12.4%; 24/193). Mutations in three manually induced RIF-resistant tuberculosis strains were located at codons 531 and 526, respectively. The results indicate that about 90% of rifampicin-resistant M. tuberculosis strains isolated in China had rpoB mutations;531-Ser and 526-His were the most common positions substituted; high-level rifampicin-resistant strains had a higher frequency of 531-Ser mutations than low-level rifampicin-resistant strains. Sequencing analysis of the 81 bp fragment in the rpoB gene is useful in predicting the rifampicin-resistant phenotype.

Antibiotics, Antitubercular↗
PubMed2002

[Association between the genetic polymorphisms of beta2-adrenergic receptor gene and the asthma susceptibility and clinical phenotypes in a Chinese population].

OBJECTIVE: To determine whether genetic polymorphisms of beta2-adrenergic receptor gene affect asthma susceptibility and play a role in disease regulation. METHODS: One hundred and sixty-six unrelated childhood asthma cases and 32 families with 192 samples were studied. The polymorphisms at amino acid positions 16, 27, 164 and nucleic acid residue 523 were genotyped by polymerase chain reaction-restriction endonuclease digestion. RESULTS: The amino acid 164 Thr/Ile variant was seen only in the heterozygote form, and it occurred with a frequency of 3% which is similar to the published results among Caucasians. There were significant differences in the allele frequencies of the other 3 polymorphisms between Chinese and the published results among Caucasians (P<0.001). No polymorphism was found to be associated with total serum IgE, the number of positive prick skin test and FEV1. No significant association was noted between either the arginine-glycine 16 or the glutamine-glutamate 27 polymorphisms and the airway responsiveness to beta2-agonists in childhood asthma cases. CONCLUSION: In this study population, the authors were unable to confirm that the polymorphism of beta2-adrenergic receptor gene is a crucial factor of the susceptibility to asthma and a major genetic determinant of different clinical status.

Adult↗