Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1...Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.展开更多
Abstract:Objective To detect the mutation frequency of the bcl 10 gene in the early and advanced stages of hepatocellular carcinoma (HCC).Methods Genome DNA samples were extracted from 46 cases of fresh HCC tumor tiss...Abstract:Objective To detect the mutation frequency of the bcl 10 gene in the early and advanced stages of hepatocellular carcinoma (HCC).Methods Genome DNA samples were extracted from 46 cases of fresh HCC tumor tissues and their non-tumor adjacent tissues. Polymerase chain reaction-single strand conformation polymorphism method was used to detect point mutations of the three exons of the bcl 10 gene. For each individual exon, six random samples from those showing abnormal DNA bands were sequenced to verify those mutations. The relationship between serum alpha-fetoprotein (AFP) level and bcl 10 mutation, between the tumor size and bcl 10 mutation was also analyzed.Results Among the 46 samples, 26 cases (56.5%) were found to have mutations in exon 1, 5 out of the 6 cases were shown to have 5744 C→G mutation by sequencing; 25 cases (54.3%) were found to have mutations in exon 2, 4 out of the 6 cases were shown to have 11?311 T deletion mutation by sequencing. Twenty-one cases (45.7%) were found to have mutations in exon 3, all of the 6 cases selected for sequencing were shown to have 14?116 C→T mutation. Statistical analysis showed that neither serum alpha-fetoprotein level nor the size of hepatocellular carcinoma has a significant relationship with bcl 10 mutation.Conclusion The bcl 10 gene has a high mutation frequency in liver cancer.展开更多
Objective To determine mutations of two common potassium channel subunit genes KCNQ1, KCNH2 causing long QT syndrome (LQTS) in the Chinese.Methods Thirty-one Chinese LQTS pedigrees were characterized for mutations in ...Objective To determine mutations of two common potassium channel subunit genes KCNQ1, KCNH2 causing long QT syndrome (LQTS) in the Chinese.Methods Thirty-one Chinese LQTS pedigrees were characterized for mutations in the two LQTS genes, KCNQ1 and KCNH2, by sequencing.Results Two novel KCNQ1 mutations, S277L in the S5 domain and G306V in the channel pore, and two novel KCNH2 mutations, L413P in the transmembrane domain S1 and L559H in the transmembrane domain S5 were identified. The triggering factors for cardiac events developed in these mutation carriers included physical exercise and excitation. Mutation L413P in KCNH2 was associated with the notched T wave on ECGs. Mutation L559H in KCNH2 was associated with the typical bifid T wave on ECGs. Mutation S277L in KCNQ1 was associated with a high-amplitude T wave and G306V was associated with a low-amplitude T wave. Two likely polymorphisms, IVS11 +18C >T in KCNQ1 and L520V in KCNH2 were also identified in two LQTS patients.Conclusions The mutation rates for both KCNQ1 (6.4%) and KCNH2 (6.4%) are lower in the Chinese population than those from North America or Europe.展开更多
Objective To detect new mutations among 29 glucose 6 phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province Methods The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient ind...Objective To detect new mutations among 29 glucose 6 phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province Methods The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing Results Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified Nine cases remained to be defined The G1381A mutation is a novel mis sense mutation, with a substitution of threonine for alanine (A461T) The resultant G6PD had reduced enzymatic activity In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation Conclusion A novel mis sense mutation G1381A was found This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity The loss of the Stu I restriction site offers a rapid method for the detection of this mutation展开更多
Background Gap junction channels formed by connexin43 (Cx43) protein are important in cardiac morphogenesis, and Cx43 gene is thought to be associated with congenital heart malformation (CHM). This study was undertak...Background Gap junction channels formed by connexin43 (Cx43) protein are important in cardiac morphogenesis, and Cx43 gene is thought to be associated with congenital heart malformation (CHM). This study was undertaken to detect the mutations of Cx43 in fetuses with CHM.Methods Cx43 extron DNA was amplified by PCR from 16 fetuses with a variety of CHM. The PCR products were analyzed by SSCP and DNA sequencing. Thirty children who had no CHM were selected as controls. Results Eight homozygous mutations of Cx43 were observed in a fetus with double outlet right ventricule (DORV), five of the 8 mutations were missense mutations including Arg239Trp, Ser251Thr, Ala253Pro, Pro283Leu and Thr290Asn, and the remaining 3 were silent polymorphisms including Gly252Gly, Pro256Pro and Thr275Thr. No mutations were found in other fetuses and the control group.Conclusions Mutations of Cx43 may be associated with congenital conotruncal anomalies. PCR-SSCP is an effective method for screening the mutations of Cx43.展开更多
Objective To investigate the K-ras mutation pattern in six pancreatic cancer cell lines from Chinese patients. Methods All six cell lines were analyzed for mutations in exon 1 of the K-ras gene by polymerase chain rea...Objective To investigate the K-ras mutation pattern in six pancreatic cancer cell lines from Chinese patients. Methods All six cell lines were analyzed for mutations in exon 1 of the K-ras gene by polymerase chain reaction (PCR) and direct sequencing.Results All 6 pancreatic cancer cell lines had GGT→GTT mutations at K-ras codon 12 but no mutations at codon 13.Conclusion The unique GGT→GTT mutation at codon 12 plays a potential role in the carcinogenesis of pancreatic cancers in Chinese.展开更多
Objective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comp...Objective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comprised of 1251 subjects(915 men and 336 women)aged 15 -80 years and none was HIV-1 positive.Genotyping of allelic CCR5-△32,CCR2-641 and SDF1-3' A variants was performed using PCR or PCR/RFLP assay,and further confirmed by direct DNA sequencing.Results Our finding shows that the△32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119(n= 1254).The frequencies of mutant CCR2-641 and SDF1-3'A alleles were 0.20023(n = 1251)and 0.2873(n = 893),in this population,which are higher than those found in American Caucasians.Furthermore the polymorphisms of CCR2-641 and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians.Statistical analysis showed that the genotype distribution of CCR5-△32,CCR2-641 and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation.Conclusion The CCR5-△32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese.The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791)in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients.展开更多
Objectives To review the identified deafness genes related to nonsyndromic hearing loss (NSHL) and summarize their expressions and functions in the cochlea and to introduce the current studies of molecular genetics o...Objectives To review the identified deafness genes related to nonsyndromic hearing loss (NSHL) and summarize their expressions and functions in the cochlea and to introduce the current studies of molecular genetics on NSHL in China Methods The presented data are based on a review of the literature as well as the author's experience with NSHL and communications with other researchers in China over the past 3 years Results Currently, 23 deafness genes related to NSHL have been cloned and identified Some genes are associated with both NSHL and syndromic hearing loss (SHL), in both dominant and recessive deafness Deafness genes have a highly specific expression pattern in the inner ear Some functional categories are starting to emerge from a characterization of deafness genes There are interacting genes in the genetic background that influence the extent of hearing impairment The GJB3 gene, which is associated with high frequency hearing impairment, was cloned in a Chinese laboratory Mutations in some genes, such as GJB2 and mitochondrial 12S rRNA, have been screened in Chinese patients with NSHL Mapping new deafness gene loci as well as identifying new genes and their functions is an active area of study in China Conclusions It is challenging for us to continue identifying new deafness genes and analyze gene functions By identifying genes responsible for monogenic hearing impairment, more insight may be gained into the molecular process of hearing and the pathology of hearing loss展开更多
Objective To investigate the expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF/IL-3/IL-5 receptor common beta chain (βc receptor) in an adult patient with idiopathic pulmonary al...Objective To investigate the expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF/IL-3/IL-5 receptor common beta chain (βc receptor) in an adult patient with idiopathic pulmonary alveolar proteinosis (PAP), so as to demonstrate the possible association of the GM-CSF and βc receptor with the pathogenesis of human PAP.Methods The GM-CSF levels were measured with a commercial ELISA kit (sensitivity 5?pg/ml) and the βc receptor expression on the cell surface was detected by flow cytometry analysis. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was employed to detect the expression of the GM-CSF mRNA and the βc receptor mRNA in peripheral blood mononuclear cells and alveolar macrophages. The entire coding regions of the GM-CSF cDNA and the βc receptor cDNA were sequenced by the Sanger dideoxy-mediated chain termination method to detect possible mutations.Results The patient with PAP failed to release the GM-CSF protein either from circulating mononuclear cells or from alveolar macrophages. The expression of the GM-CSF mRNA was normal after the stimulation of lipopolysaccharide, whereas a point mutation at position 382 of the GM-CSF cDNA from 'T' to 'C' was revealed by cDNA sequencing, which caused a change in amino acid 117 of the protein from isoleucine to threonine. The βc receptor expression on the cell surface was normal, and the βc receptor mRNA expression and the sequence of the entire coding region of the βc receptor were also normal.Conclusions The decreased GM-CSF production is associated with the pathogenesis of human PAP. A point mutation of the GM-CSF cDNA may contribute to the decreased GM-CSF production in our adult PAP patient. The mutation of the βc receptor in some of paediatric patients with PAP may not be a common problem in adult patients.展开更多
To study the resistance mechanism of clinical isolates of Ureaplasma urealyticum resistant to fluoroquinolones Methods Thirteen isolates of Ureaplasma urealyticum resistant to six fluoroquinolones were selected out ...To study the resistance mechanism of clinical isolates of Ureaplasma urealyticum resistant to fluoroquinolones Methods Thirteen isolates of Ureaplasma urealyticum resistant to six fluoroquinolones were selected out of 184 clinical isolates and their QRDRs (quinolone resistance determining region) gyrA, gyrB, parC and parE were amplified by PCR Sequencing results were compared to those susceptible reference strains and a comparison of deduced amino acid sequences were performed Results Sequence comparison revealed a C to A change at 87nt of gyrA QRDR leading to the substitution of Asp95 with glutamic acid and a C to T change at 50nt of parC QRDR leading to the substitution of Ser80 with leucine Conclusion These results suggest that a C to A change at 87nt of gyrA QRDR and a C to T change at 50nt of parC QRDR are associated with fluoroquinolone resistance of Ureaplasma urealyticum展开更多
Background Hereditary nonpolyposis colorectal cancer (HNPPC) is one of the most common genetic syndrome related with mutation of human mismatch repair genes. This study was to evaluate the clinical significance of su...Background Hereditary nonpolyposis colorectal cancer (HNPPC) is one of the most common genetic syndrome related with mutation of human mismatch repair genes. This study was to evaluate the clinical significance of suspected hereditary nonpolyposis colorectal cancer (sHNPCC) criteria I and the clinical and genetic features of International Collaborative Group-HNPCC (ICG-HNPCC) and sHNPCC families Methods Twenty-nine ICG-HNPCC families fulfilling the Amsterdam criteria and 34 sHNPCC families fulfilling the sHNPCC criteria I were collected PCR-SSCP and DNA sequencing analysis were employed to screen the germline mutations of the hMLH1 and hMSH2 genes in these families Results The ICG group had more colorectal cancer (CRC) patients per family than did the suspected group ( P <0 05) No statistical difference was observed in Lynch classification and familial tumor spectrum In both groups of families, colorectal cancer was the most frequent malignancy, and carcinomas of the stomach, pancreas and uterus were the three most common extracolonic malignancies Mutation screening showed that ICG-HNPCC and sHNPCC families had a similar mutation rate (31 0% vs 29 4%, P >0 05), mutation type, and mutation distribution Comparison of the families with and without mutation showed no significant difference in CRC patients per family, Lynch classification, and tumor spectrum Conclusions ICG-HNPCC and sHNPCC families that have similar clinical manifestations and genetic basis indicate a similar nature for cancer development The application of sHNPCC criteria I will facilitate clinical diagnosis and treatment of small families展开更多
文摘Objective To develop a high throughput mutational detection method by mutiple fluorescence-labeled polymerase chain reaction(PCR)products.Methods A total of 27 known mutations including 22 substitutions,3 insertions(1,2 and 7 bp)and 2 deletions(1 and 2 bp)in the hepatocyte nuclear factor(HNF)-4α,glucokinase and HNF-1α genes were tested.During nested PCR,amplified fragments were labeled with three fluorescent dyes.PCR products were visualized with an ABI-377 fluorescence sequencer using 5% glycerol or 10% sucrose in nondenaturing gel conditions.Results Twenty-five of 27 variants(93%)could be detected by combining 5% glycerol and 10% sucrosegel matrix conditions.Twenty-two of 27(82%)and 18 of 27(67%)variants were identified using 5%glycerol and 10% sucrose conditions,respectively.Conclusion This fluorescence-based PCR single strand conformation polymorphism technique represents a simple,non-hazardous,time-saving and sensitive method for high throughput mutation detection.
文摘Abstract:Objective To detect the mutation frequency of the bcl 10 gene in the early and advanced stages of hepatocellular carcinoma (HCC).Methods Genome DNA samples were extracted from 46 cases of fresh HCC tumor tissues and their non-tumor adjacent tissues. Polymerase chain reaction-single strand conformation polymorphism method was used to detect point mutations of the three exons of the bcl 10 gene. For each individual exon, six random samples from those showing abnormal DNA bands were sequenced to verify those mutations. The relationship between serum alpha-fetoprotein (AFP) level and bcl 10 mutation, between the tumor size and bcl 10 mutation was also analyzed.Results Among the 46 samples, 26 cases (56.5%) were found to have mutations in exon 1, 5 out of the 6 cases were shown to have 5744 C→G mutation by sequencing; 25 cases (54.3%) were found to have mutations in exon 2, 4 out of the 6 cases were shown to have 11?311 T deletion mutation by sequencing. Twenty-one cases (45.7%) were found to have mutations in exon 3, all of the 6 cases selected for sequencing were shown to have 14?116 C→T mutation. Statistical analysis showed that neither serum alpha-fetoprotein level nor the size of hepatocellular carcinoma has a significant relationship with bcl 10 mutation.Conclusion The bcl 10 gene has a high mutation frequency in liver cancer.
基金This study was supported by grants from the National Natural Science Foundation of China (No.30170381) the American Heart Association Ohio-Affiliate (No. AHA 0051205B).
文摘Objective To determine mutations of two common potassium channel subunit genes KCNQ1, KCNH2 causing long QT syndrome (LQTS) in the Chinese.Methods Thirty-one Chinese LQTS pedigrees were characterized for mutations in the two LQTS genes, KCNQ1 and KCNH2, by sequencing.Results Two novel KCNQ1 mutations, S277L in the S5 domain and G306V in the channel pore, and two novel KCNH2 mutations, L413P in the transmembrane domain S1 and L559H in the transmembrane domain S5 were identified. The triggering factors for cardiac events developed in these mutation carriers included physical exercise and excitation. Mutation L413P in KCNH2 was associated with the notched T wave on ECGs. Mutation L559H in KCNH2 was associated with the typical bifid T wave on ECGs. Mutation S277L in KCNQ1 was associated with a high-amplitude T wave and G306V was associated with a low-amplitude T wave. Two likely polymorphisms, IVS11 +18C >T in KCNQ1 and L520V in KCNH2 were also identified in two LQTS patients.Conclusions The mutation rates for both KCNQ1 (6.4%) and KCNH2 (6.4%) are lower in the Chinese population than those from North America or Europe.
基金ThisstudywassupportedbytheNationalNaturalScienceFoundationofChina (No 3 9670 40 1)
文摘Objective To detect new mutations among 29 glucose 6 phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province Methods The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing Results Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified Nine cases remained to be defined The G1381A mutation is a novel mis sense mutation, with a substitution of threonine for alanine (A461T) The resultant G6PD had reduced enzymatic activity In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation Conclusion A novel mis sense mutation G1381A was found This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity The loss of the Stu I restriction site offers a rapid method for the detection of this mutation
文摘Background Gap junction channels formed by connexin43 (Cx43) protein are important in cardiac morphogenesis, and Cx43 gene is thought to be associated with congenital heart malformation (CHM). This study was undertaken to detect the mutations of Cx43 in fetuses with CHM.Methods Cx43 extron DNA was amplified by PCR from 16 fetuses with a variety of CHM. The PCR products were analyzed by SSCP and DNA sequencing. Thirty children who had no CHM were selected as controls. Results Eight homozygous mutations of Cx43 were observed in a fetus with double outlet right ventricule (DORV), five of the 8 mutations were missense mutations including Arg239Trp, Ser251Thr, Ala253Pro, Pro283Leu and Thr290Asn, and the remaining 3 were silent polymorphisms including Gly252Gly, Pro256Pro and Thr275Thr. No mutations were found in other fetuses and the control group.Conclusions Mutations of Cx43 may be associated with congenital conotruncal anomalies. PCR-SSCP is an effective method for screening the mutations of Cx43.
文摘Objective To investigate the K-ras mutation pattern in six pancreatic cancer cell lines from Chinese patients. Methods All six cell lines were analyzed for mutations in exon 1 of the K-ras gene by polymerase chain reaction (PCR) and direct sequencing.Results All 6 pancreatic cancer cell lines had GGT→GTT mutations at K-ras codon 12 but no mutations at codon 13.Conclusion The unique GGT→GTT mutation at codon 12 plays a potential role in the carcinogenesis of pancreatic cancers in Chinese.
基金ThisprojectwassupportedbyagrantfromNationalNaturalSciencesFoundationofthePRChina (No 3 9770 683 )
文摘Objective To evaluate the frequencies and polymorphisms of CCR5-△32,CCR2-641 and SDF1-3'A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin.Methods This cohort was comprised of 1251 subjects(915 men and 336 women)aged 15 -80 years and none was HIV-1 positive.Genotyping of allelic CCR5-△32,CCR2-641 and SDF1-3' A variants was performed using PCR or PCR/RFLP assay,and further confirmed by direct DNA sequencing.Results Our finding shows that the△32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119(n= 1254).The frequencies of mutant CCR2-641 and SDF1-3'A alleles were 0.20023(n = 1251)and 0.2873(n = 893),in this population,which are higher than those found in American Caucasians.Furthermore the polymorphisms of CCR2-641 and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians.Statistical analysis showed that the genotype distribution of CCR5-△32,CCR2-641 and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation.Conclusion The CCR5-△32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese.The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791)in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients.
文摘Objectives To review the identified deafness genes related to nonsyndromic hearing loss (NSHL) and summarize their expressions and functions in the cochlea and to introduce the current studies of molecular genetics on NSHL in China Methods The presented data are based on a review of the literature as well as the author's experience with NSHL and communications with other researchers in China over the past 3 years Results Currently, 23 deafness genes related to NSHL have been cloned and identified Some genes are associated with both NSHL and syndromic hearing loss (SHL), in both dominant and recessive deafness Deafness genes have a highly specific expression pattern in the inner ear Some functional categories are starting to emerge from a characterization of deafness genes There are interacting genes in the genetic background that influence the extent of hearing impairment The GJB3 gene, which is associated with high frequency hearing impairment, was cloned in a Chinese laboratory Mutations in some genes, such as GJB2 and mitochondrial 12S rRNA, have been screened in Chinese patients with NSHL Mapping new deafness gene loci as well as identifying new genes and their functions is an active area of study in China Conclusions It is challenging for us to continue identifying new deafness genes and analyze gene functions By identifying genes responsible for monogenic hearing impairment, more insight may be gained into the molecular process of hearing and the pathology of hearing loss
文摘Objective To investigate the expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF/IL-3/IL-5 receptor common beta chain (βc receptor) in an adult patient with idiopathic pulmonary alveolar proteinosis (PAP), so as to demonstrate the possible association of the GM-CSF and βc receptor with the pathogenesis of human PAP.Methods The GM-CSF levels were measured with a commercial ELISA kit (sensitivity 5?pg/ml) and the βc receptor expression on the cell surface was detected by flow cytometry analysis. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was employed to detect the expression of the GM-CSF mRNA and the βc receptor mRNA in peripheral blood mononuclear cells and alveolar macrophages. The entire coding regions of the GM-CSF cDNA and the βc receptor cDNA were sequenced by the Sanger dideoxy-mediated chain termination method to detect possible mutations.Results The patient with PAP failed to release the GM-CSF protein either from circulating mononuclear cells or from alveolar macrophages. The expression of the GM-CSF mRNA was normal after the stimulation of lipopolysaccharide, whereas a point mutation at position 382 of the GM-CSF cDNA from 'T' to 'C' was revealed by cDNA sequencing, which caused a change in amino acid 117 of the protein from isoleucine to threonine. The βc receptor expression on the cell surface was normal, and the βc receptor mRNA expression and the sequence of the entire coding region of the βc receptor were also normal.Conclusions The decreased GM-CSF production is associated with the pathogenesis of human PAP. A point mutation of the GM-CSF cDNA may contribute to the decreased GM-CSF production in our adult PAP patient. The mutation of the βc receptor in some of paediatric patients with PAP may not be a common problem in adult patients.
基金ThisstudywassupportedbyagrantfromtheEducationCommitteeofHunanProvince (No 0 0A0 0 9)
文摘To study the resistance mechanism of clinical isolates of Ureaplasma urealyticum resistant to fluoroquinolones Methods Thirteen isolates of Ureaplasma urealyticum resistant to six fluoroquinolones were selected out of 184 clinical isolates and their QRDRs (quinolone resistance determining region) gyrA, gyrB, parC and parE were amplified by PCR Sequencing results were compared to those susceptible reference strains and a comparison of deduced amino acid sequences were performed Results Sequence comparison revealed a C to A change at 87nt of gyrA QRDR leading to the substitution of Asp95 with glutamic acid and a C to T change at 50nt of parC QRDR leading to the substitution of Ser80 with leucine Conclusion These results suggest that a C to A change at 87nt of gyrA QRDR and a C to T change at 50nt of parC QRDR are associated with fluoroquinolone resistance of Ureaplasma urealyticum
文摘Background Hereditary nonpolyposis colorectal cancer (HNPPC) is one of the most common genetic syndrome related with mutation of human mismatch repair genes. This study was to evaluate the clinical significance of suspected hereditary nonpolyposis colorectal cancer (sHNPCC) criteria I and the clinical and genetic features of International Collaborative Group-HNPCC (ICG-HNPCC) and sHNPCC families Methods Twenty-nine ICG-HNPCC families fulfilling the Amsterdam criteria and 34 sHNPCC families fulfilling the sHNPCC criteria I were collected PCR-SSCP and DNA sequencing analysis were employed to screen the germline mutations of the hMLH1 and hMSH2 genes in these families Results The ICG group had more colorectal cancer (CRC) patients per family than did the suspected group ( P <0 05) No statistical difference was observed in Lynch classification and familial tumor spectrum In both groups of families, colorectal cancer was the most frequent malignancy, and carcinomas of the stomach, pancreas and uterus were the three most common extracolonic malignancies Mutation screening showed that ICG-HNPCC and sHNPCC families had a similar mutation rate (31 0% vs 29 4%, P >0 05), mutation type, and mutation distribution Comparison of the families with and without mutation showed no significant difference in CRC patients per family, Lynch classification, and tumor spectrum Conclusions ICG-HNPCC and sHNPCC families that have similar clinical manifestations and genetic basis indicate a similar nature for cancer development The application of sHNPCC criteria I will facilitate clinical diagnosis and treatment of small families