The correlation between EGFR mutation status and the risk of brain metastasis in patients with lung adenocarcinoma.

To explore the correlation between epidermal growth factor receptor (EGFR) mutation status and the risk of brain metastasis (BM) in patients with lung adenocarcinoma, the clinical data of 100 patients with pathologically confirmed lung adenocarcinoma and known EGFR mutation status at exon 18, 19, 20, or 21 were analyzed retrospectively. The incidence of BM was similar between patients with wild-type EGFR and those with EGFR mutations (p = 0.48). However, among patients with EGFR mutations, the incidence of BM was significantly higher in patients with mutation at exon 19 than in patients with mutation at other sites (p = 0.007). Besides, among patients with heterochronous BM, 66.7 % had EGFR mutations. Regarding brain-metastasis-free survival (BMFS), patients with EGFR sensitive mutations (mutation at exon 19/21/and dual mutation) had significantly shorter BMFS compared with patients with wild-type EGFR (p = 0.018). For patients treated only with chemotherapy, BM was an unfavorable prognostic factor. Patients with BM had worse overall survival compared with those without BM (p = 0.035). However, in patients with BM and EGFR sensitive mutations, those treated with tyrosine kinase inhibitors (TKIs) had significantly longer overall survival compared with those treated with chemotherapy only (p = 0.0081). In conclusion, among patients with EGFR mutations, those mutated at exon 19 had the highest incidence of BM. Furthermore, patients with EGFR mutations are more likely to develop heterochronous BM. The BMFS was significantly shorter in patients with EGFR sensitive mutations. TKIs improved the survival of patients with lung adenocarcinoma and BM who harbored EGFR sensitive mutations.

[Entamoeba gingivalis infection among college students in Tangshan].

OBJECTIVE: To investigate the prevalence of Entamoeba gingivalis infection in college students in Tangshan, and analyze the relationship between the infection and human behaviors. METHODS: 551 students of grades 1-3 from six colleges in Tangshan received questionnairing, which covered the oral health state, teeth-brushing, xylitol gum-chewing, diet fondness, and smoking. Specimens were taken from the tooth surface of the lesion or fouling materials by using disinfected toothpicks and the smears were observed microscopically to examine Entamoeba gingivalis infection. RESULTS: The prevalence of Entamoeba gingivalis infection was 28.3% (156/551), 30.4% (55/181) and 24.6% in males and females (91/370) respectively (chi2=2.09, P>0.05). The prevalence in students with or without oral disorders was 41.2% (84/204) and 20.8% (72/347) respectively, with a significant statistical difference (chi2=26.41, P<0.01); it was 22.5% (53/236) and 32.7% (103/315) among students who cleaned their teeth regularly or irregularly (chi2=6.97, P<0.01); it was 18.3% (17/93) and 30.4% (139/458) among those usually with or without chewing xylitol gum (chi2=5.55, P<0.05). CONCLUSION: Entamoeba gingivalis infection is common in the college students in Tangshan and it has a close relation to the oral hygiene habits and the presence of oral disorders.

Critical role of Cys168 in noggin protein's biological function.

Previous studies have indicated that noggin exerts its neural inducing effect by binding and antagonizing bone morphogenetic protein 4 (BMP4). In order to further clarify the relationship between the structure and the function of noggin, and elucidate the possible mechanism responsible for noggin-BMP4 interaction, we generated three noggin mutants, C168S, C174S and C197S, by using a site-directed mutagenesis method. Ectopic expression of wild-type (WT) noggin, C174S or C197S, in Xenopus animal caps (ACs) by mRNA injection converted the explants (prospective ectoderm) into neural tissue, as indicated by the neural-like morphology and expression of the neural cell adhesion molecule (NCAM) in the ACs. In contrast, ACs expressing C168S suffered an epidermal fate similar to the control caps. Similarly, among the three mutants, only C168S lost the dorsalizing function. These studies highlight the critical role played by Cys168 in noggin's biological activities. It probably participates in the formation of an intermolecular disulfide bridge.

[Establishment of transgenic Xenopus laevis by intracytoplasmic sperm injection].

OBJECTIVE: To study the feasibility of establishing transgenic laevis by intracytoplasmic sperm injection (ICSI). METHODS: The testes of mature Xenopus laevis were taken for the purification of their sperms, which was subsequently incubated with digitonin to prepare concentrate of the sperms. Treatment of the concentrate with linearized reporter vector pCMV-EGFP-N1 was performed, and the sperms were then injected into unfertilized ova harvested from female laevis, followed by culture and observation of the development of the ova. RESULTS: The condensed sperm we obtained were of high quality and after intracytoplasmic injection into the ova, a fertilization rate of 10% was achieved and 20% of the zygotes survived the neurula stages and developed into tadpoles, but all of which were slightly deformed. The integration ratio of green fluorescent protein (GFP) reporter gene was 81%, but GFP expression was not observed in the laevis. CONCLUSION: ICSI is a simple and practicable method for establishing transgenic Xenopus laevis.