RESUMO
Sepsis is a systemic inflammatory response to infection and includes severe sepsis, septic shock and death. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is one cell adhesion molecule expressed on platelets and leukocytes. It regulates platelet activation and mediates transendothelial migration of leukocytes, thus maintaining the integrity of the vasculature. There are some animal experiments associated with the protective role of PECAM-1 against septic shock. However few host genetic risk factors have been identified for sepsis severity and susceptibility to septic shock. A case-control study was conducted, which included 217 patients with sepsis and 90 control subjects recruited from our hospital. One single nucleotide polymorphisms (SNP) of PECAM-1 gene Leu125Val (C373G) was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Serum soluble PECAM-1 (sPECAM-1) levels were determined by enzyme-linked immunosorbent assay (ELISA). Our results showed that the CG and GG genotypes of SNP in Leu125Val of PECAM-1 (rs668: C>G) was significantly associated with increased susceptibility to septic shock compared with CC genotype in sepsis patients (CG genotype, OR: 2.493, 95% CI: 1.175~5.287, P = 0.016; GG genotype: OR: 3.328, 95% CI: 1.445~7.666, P = 0.004). The serum levels of sPECAM-1 in the sepsis patients (47.1 ± 17.5 ng/ml) were significantly higher than those in the healthy controls (61.3 ± 20.9 ng/ml, P<0.01). Among sepsis patients, the serum levels of sPECAM-1 were significantly higher in CG and GG genotype than in CC genotype. In septic shock patients, nonsurvivors (83.7 ± 12.6 ng/ml, n = 69) had a significantly higher serum sPECAM-1 level than the survivors (76.9 ± 12.7 ng/ml, n = 53) (P<0.01). In conclusion, PECAM-1 Leu125Val polymorphism and its sPECAM-1 levels are associated with sepsis severity and susceptibility to septic shock.
RESUMO
Hemophilia B (HB) is a recessive X-linked inherited disorder, the pathogenesis of HB is deficiency or functional abnormalities of coagulation factor IX, which is caused by F9 gene mutations. To explore the mechanism of its molecular pathology, 40 patients with HB were studied with polymerase chain reaction (PCR) and direct sequencing. The diagnosis of HB patients were based on clinical manifestation and deficient factor IX activity in plasma. DNA was routinely extracted from peripheral blood cells of the patients and their relatives, all the 8 exons and their flanking boundaries were amplified by PCR, and the PCR products were screened by direct sequencing. Mutations which were found in study need to exclude polymorphism. The results showed that 34 mutations were confirmed in 40 HB patients, including 6 nonsense mutations, 24 missense mutations, 2 splice site mutations and 2 frame mutations for 1 or 2 nucleotide insertion. After retrieved, 4 missense mutations and 1 frameshift mutation were found for the first time. Among the 34 mutations, 2 mutations in signal peptide, 7 mutations in propeptide and gla domain, 7 mutations in epidermal growth factor-like domain, 3 mutations in activation domain, 15 mutations in serine protease or catalytic domain. It is concluded that gene analysis can directly explain molecular mechanism of hemophilia B and also provides the foundation for further studies to the function of coagulation factor IX. There is obvious heterogeneity in F9 gene mutation and missense mutation is still the main way of mutation, which are closely related to clinical features. DNA sequencing and linkage analysis are efficient methods for HB carriers and prenatal gene diagnosis.