Association of TNF-α-238G/A and 308 G/A Gene Polymorphisms with Pulmonary Tuberculosis among Patients with Coal Worker’s Pneumoconiosis

Objectives Tumor necrosis factor-α （TNF-α） may play an important role in host＇s immune response to mycobacterium tuberculosis （M. tuberculosis） infection. This study was to investigate the association of TNF-α gene polymorphism with pulmonary tuberculosis （TB） among patients with coal worker＇s pneumoconiosis （CWP）. Methods A case-control study was conducted in 113 patients with confirmed CWP complicated with pulmonary TB and 113 non-TB controls with CWP. They were matched in gender, age, job, and stage of pneumoconiosis. All participants were interviewed with questionnaires and their blood specimens were collected for genetic determination with informed consent. The TNF-α gene polymorphism was determined with polymerase chain reaction of restriction fragment length polymorphism （PCR-RFLP）. Frequency of genotypes was assessed for Hardy-Weinberg equilibrium by chi-square test or Fisher＇s exact probability. Factors influencing the association of individual susceptibility with pulmonary TB were evaluated with logistic regression analysis. Gene-environment interaction was evaluated by a multiplieative model with combined OR. All data were analyzed using SAS version 8.2 software. Results No significant difference in frequency of the TNF-α-308 genotype was found between CWP complicated with pulmonary TB and non-TB controls （2,2=5.44, P=-0.07）. But difference in frequency of the TNF-α-308 A allele was identified between them （2,2-5.14, P=0.02）. No significant difference in frequencies of the TNF-α-238 genotype and allele （P=0.23 and P=0.09, respectively） was found between cases and controls either, with combined （GG and AA） OR of 3.96 （95% confidence interval of 1.30-12.09） at the -308 locus of the TNF-α gene, as compared to combination of the TNF-α-238 GG and TNF-α-308 GG genotypes. Multivariate-adjusted odds ratio of the TNF-α-238 GG and TNF-α-308 GA genotypes was 1.98 （95% CI of 1.06-3.71） for risk for pulmonary TB in patients with CWP. There was a synergic interaction between the TNF-a-308 GG genotype and body mass index （OR=4.92）, as well as an interaction between the TNF-α-308 GG genotype and history of BCG immunization or history of TB exposure. And, the interaction of the TNF-α-238 GG genotype and history of BCG immunization or TB exposure with risk for pulmonary TB in them was also indicated. Conclusions TNF-α-308 A allele is associated with an elevated risk for pulmonary TB, whereas TNF-α-238 A allele was otherwise.

The Study of Apolipoprotein B Gene Polymorphisms by Polymerase Chain Reaction.

Two polymorphic sites of apolipoprotein B（apoB） gene-Xbal and EcoRI were examined in a sample of 103 patients with documented coronary heart disease （CHD） and 100 healthy individuals. It was demonstrated: （1） The frequencies of rare Xallele （presence of Xbal cutting site） and E-allele （absence of cutting site） were significantly higher in CHD patients than those in controls. It was suggested that these genetic variations were associated with CHD. （2） The patients with genotype of XXhad significantly lower

Studies on the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer

AIM To study the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer.

Detecting drug resistant genetic mutation among pneumoconiosis patients complicated with tuberculosis in Mycobacterium tuberculosis L-forms application of PCR-SSCP technique in Huainan mining district

Objective： To study the relationship between drug resistant genetic mutation and drug resistance in Mycobacterium tuberculosis L-form, discuss the internal relationship between drug resistances and drug-resistant related genes and explore the value of PCR- SSCP to clinical application. Methods： A total of 52 clinically isolated strains of tuberculosis L-form were collected among 97 pneumoconiosis patients complicated with tuberculosis. The gene mutations of katG, rpoB and rpsL were detected by PCR-SSCP, and the results were compared with those analyzed by traditional antimicrobial susceptibility test（AST）. Results： The gene muta- tion rates of katG, rpoB and rpsL by PCR-SSCP were respectively 57.70% （30/52）, 65.38% （32/52） and 40.38% （21/52）. The rate of reversion was 78.85%（41/52） and the result of drag-resistant genes was invariable. The results of AST showed that there were 40 （76.92%） multi-drug resistant strains in 52 clinically isolated strains. The number for three-drug resistant strain was 21 （40.38%） and that of two-drug resistant was 19（36.54%）, but only 12（23.08%） strains were one drug resistant. The rate of total drug-resistance was 100%, but there were 15 strains of allied mutation of three genes, 16 of two mutations and 6 of only one by PCR-SSCP. The coincidences were respectively 71.43%, 84.12% and 50.00%. Then there was no significant difference between the allied mutations of multi-drug resistant gene and the mutations of only one drug resistant gene （P 〉 0.05）. Conclusion： PCR-SSCP technique has a higher sensibility and specificity to detect the genes of katG, rpoB and rpsL in tuberculosis L-form among pneumoconiosis complicated with tuberculosis,and the detecting rate of two drug resistant strains and three drug resistant strains was higher. The combined application of PCR-SSCP and AST has advantages at earlier diagnosis and guidance of clinical medications.

Study on mitochondrial DNA diversity among 7 inbred strains of mice

Objective：To study the genetic variation of mitochondrial DNA （mtDNA） among common laboratory strains of inbred mice. Methods： The genetic polymorphism of mtDNA among 4 classical laboratory strains of inbred mice and 3 inbred strains of mice established in China was analyzed by polymerase chain reaction coupled with restriction fragment length polymorphism（PCR-RFLP） and PCR coupled with single-stranded conformation polymorphism（PCR-SSCP）. Results： With regard to the D-loop （Displacement loop, D-loop）, tRNA^ Met＋Glu＋Ile, and ND3 （NADH dehydrogenase subunit 3, ND3） gene fragments of mtDNA from these mice,no variation was revealed by PCR-RFLP at 46 restriction enzyme sites. Further analyzed by PCR-SSCP,the D-loop 5＇fragment and 3＇end fragment of mtDNA from these mice also showed no genetic variation. Conclusion： Owing to maternal mode of inheritance of mtDNA,the results indicate that these common inbred strains of mice share the same maternal lineage.

Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene

Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A≤14 years, group B 15-30 years, group C≥31 years.Results In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P<0.05) and that of LMP7-B/A was higher (54% vs 31%, P<0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P<0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.Conclusions LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.

Quantitative chimerism kinetics in relapsed leukemia patients after allogeneic hematopoietic stem cell transplantation

Background Chimerism analysis is an important tool for the surveillance of post-transplant engraftment. It offers the possibility of identifying impending graft rejection and recurrence of underlying malignant or non-malignant disease. Here we investigated the quantitative chimerism kinetics of 21 relapsed leukemia patients after allogeneic hematopoietic stem cell transplantation （HSCT）. Methods A panel of 29 selected sequence polymorphism （SP） markers was screened by real-time polymerase chain reaction （RT-PCR） to obtain the informative marker for every leukemia patient. Quantitative chimerism analysis of bone marrow （BM） samples of 21 relapsed patients and 20 patients in stable remission was performed longitudinally. The chimerisms of BM and peripheral blood （PB） samples of 14 patients at relapse were compared. Results Twenty-one patients experienced leukemia relapse at a median of 135 days （range, 30-720 days） after transplantation. High recipient chimerism in BM was found in all patients at relapse, and increased recipient chimerism in BM samples was observed in 90% （19/21） of patients before relapse. With 0.5% recipient DNA as the cut-off, median time between the detection of increased recipient chimerism and relapse was 45 days （range, 0-120 days）, with 76% of patients showing increased recipient chimerism at least 1 month prior to relapse. Median percentage of recipient DNA in 20 stable remission patients was 0.28%, 0.04%, 0.05%, 0.05%, 0.08%, and 0.05% at 1, 2, 3, 6, 9, and 12 months, respectively, after transplantation. This was concordant with other specific fusion transcripts and fluorescent in situ hybridization examination. The recipient chimerisms in BM were significantly higher than those in PB at relapse （P=-0.001）. Conclusions This SP-based RT-PCR assay is a reliable method for chimerism analysis. Chimerism kinetics in BM can be used as a marker of impending leukemia relapse, especially when no other specific marker is available. Based on our findings, we recommend examining not only PB samples but also BM samples in HSCT patients.