Objective To investigate the correlation between the deletion of exon 13 of hMSH2 mRNA in peripheral blood leu-kocyte and ISV12(-6) T>C polymorphism with sporadic colorectal cancer .Methods Total RNA and genomic DNA were extracted from peripheral blood of colorectal cancer patients and healthy controls .RT-PCR and PCR were used to amplified the mRNA and exon 13 of hMSH2 gene .The sequences of amplified hMSH2 cDNA ,ISV12(-6) T>C polymorphism and exon 13 sequence were confirmed by DNA sequencing .Results 23 of 23 (100% ) patients and 31 of 35 controls (88 .6% ,P>0 .05) were found to have an hMSH2 truncated transcript caused by a deletion of exon 13 .No deletions of exon 13 in hMSH2 gene were identified in genomic DNA .16 of 23 patients (69 .5% ) and 19 of 35 control (52 .3% ,P>0 .05) were found to have the T >C transition six bases up-stream of exon 13 of hMSH2 .Conclusion Deletion of hMSH2 mRNA exon 13 in peripheral blood leukocyte and the ISV12(-6) T>C polymorphism are common variants in population and have no correlation with sporadic colorectal cancer .The variant of splice site ISV12(-6)T>C is not a reason causing the deletion of hMSH2 mRNA exon 13 .

Objective　 To elucidate the molecular basis of G6PD deficiency in the Han and Li nationalities in Hainan, China. Methods　 Polymerase chain reaction and restriction enzyme digestion were used to screen the mutations 1388G→A, 1360C→T, 1024C→T, 592C→T,517T→C, 493A→G,487G→A,392G→T and 95A→G. Single strand conformation polymorphism analysis was used to screen the other mutations followed by DNA sequencing to characterize the mutations of the samples with abnormal SSCP bands. Results　 Of the fifty-nine Han cases with G6PD deficiency, fourteen with 1388G→A(23.7%), three with 871G→A(5.1%), one with 835A→T(1.7%), one with 517T→C(1.7%), three with 392G→T(5.1%), and four with 95A→G(6.8%) were found. Of the thirty-two Li cases with G6PD deficiency, six with 1388G→A(18.8%), three with 871G→A(9.4%), and two with 95A→G(6.3%) were found. A new mutation 835A→G which causes the substitution of Ala for Thr at 279 in a Han case was identified and named as G6PD-Haikou. The enzyme activity of the variant is about 10% of the normal and lower than the activity of the variant 835A→T with about 40% of the normal. Analysis of the 3D model of human G6PD has revealed that the hydroxyl group of Thr at 279 is a group in maintaining the interaction of the G6PD subunits. Conclusion　 The most common mutations of G6PD deficiency in Han and Li nationalities in Hainan are similar. Compared with the mutation spectrum of G6PD gene in the populations in other regions of China, the results indicate that some G6PD gene mutations are widespread in the populations of different regions in the southern part of China. The hydroxyl group of the Thr at 279 of human G6PD may be a necessary group for maintaining the interaction of the G6PD subunits and the enzyme activity.

ObjectiveTo explore the correlation between angiotensin converting enzyme (ACE) gene polymorphism and hypertension accompanying atherosclerosis in Li people in Hainan province. MethodsTwo hundred and sixty patients with hypertension accompanying atherosclerosis were selected as hypertension plus atherosclerosis group, while two hundred and seventy-six healthy people were regarded as healthy control group. ACE I/D gene polymorphism was detected by polymerase chain reaction (PCR), and the genotype frequencies and allele frequencies of DD, DI and Ⅱ were investigated. The carotid intimal-medial thickness(IMT)was measured by high-resolution ultrasound technique and mean IMT (MIMT) was calculated. Results(1) In the hypertension plus atherosclerosis group, the genotype frequencies of DD, DI and Ⅱ were 15.0%, 37.3%, 47.7%,respectively, and the allele frequencies of D and I were 33.70% and 66.30%, respectively. In the healthy control group, the genotype frequencies of DD, DI and Ⅱ were 17.8% , 40.6% and 41.7%,respectively, and the allele frequencies of D and I were 38.0% and 62.0%, respectively. There were no significant differences both in the genotype frequencies of DD, DI and Ⅱ, and in allele frequencies of D and I between the two groups (P>0. 05). (2) The age,total serum cholesterol(TC),triglyceride (TG), systolic pressure(SBP), diastolic pressure(DBP), apolipoprotein A(apoA) and apolipoprotein B (apoB) levels were significantly higher in the hypertension plus atherosclerosis group than in the control group(P<0. 05). The high density lipoprotein cholesterol(HDL-C) level was significantly lower in the hypertension plus atherosclerosis group than in the control group(P<0. 05). Logistic regression analysis showed that TG (OR = 2.14), apoA(OR = 360. 39), SBP(OR = 1.21), DBP (OR=1.08) and ACE DD genetype (OR = 0. 30) had correlation with hypertension plus atherosclerosis(all P<0. 05). The MIMT level was significantly higher in ACE DD subset than in DI and Ⅱ subset (P<0.05). ConclusionsThe ACE DD genotype increases the susceptibility of carotid atheroselerosis, which is the risk factor for hypertension accompanying atherosclerosis in Li people in Hainan province. It may be an early predictive factor in atherosclerosis.

OBJECTIVETo investigate the mechanisms of DelCD11-279 of factor XIII subunit A mRNA in the pathogenesis of hereditary factor XIII deficiency.

METHODSThe recombinant plasmids containing pET-22b(+)/FXIIIA of normal subject and proband's mother and pET-22b(+)/FXIIIA-Del of the proband were constructed and transformed into E. coli BL21. Expressing protein was analyzed by the SDS-PAGE and purified by Ni-NTA resin. Purified proteins were detected by the Western-blot. The activity of purified protein was detected by the incorporation test with EZ-LinkTM5-(Biotinamido) Pentylamine.

RESULTSThe recombinant plasmids containing pET-22b(+)/FXIIIA and pET-22b(+)/FXIIIA-Del which constructed and identified successfully by enzyme digestion and PCR, were transformed into E. coli BL21 and efficiently expressed by IPTG induction. The molecular weights of expressing proteins are 83 200 and 51 900 by the SDS-PAGE. Expressing proteins were purified by Ni-NTA resin, and were proved to be human FXIIIA proteins by Western-blot. Purified protein activity of proband's mother and proband was 95.87% and 0 of the purified FXIIIA protein activity from the normal subject, respectively.

CONCLUSIONDelCD11-279 of FXIIIA mRNA which encoding a 464 amino acids of inactive FXIIIA protein is one of the molecular mechanisms resulting in FXIII deficiency in the patient.

Escherichia coli ; Factor XIII ; Factor XIII Deficiency ; Humans ; Polymerase Chain Reaction ; RNA, Messenger ; Sequence Deletion