A series of oxazole[5,4-d] pyrimidine derivatives were designed and synthesized to discover novel compounds with antitumor activity.Compounds 8a-8m were synthesized using acetamidine hydrochloride as the start material.The structures of synthesized compounds were confirmed by IR,1H NMR,EI-MS and elemental analysis.The antiangiogenesis activities of the synthesized compounds were determined by MTT in human umbilical vein endothelial cell (HUVEC).The in vitro antitumor activities of the synthesized compounds were determined by MTT assay in A549,HepG2 and U251.Compounds 8c,8d,8g,8i and 8l were found to inhibit the proliferation of all the tested cell lines.Compound 8l exhibited noteworthy activities in A549,HepG2 and U251 cell lines with IC50value lower than the positive reference sunitinib,suggesting that compound 8l might be the promising antitumor agent for further investigation.

Objective To explore the clinical characteristics and risk factors of occult pneumonia in advanced elderly patients.Methods A total of 170 advanced elderly patients with community-acquired pulmonary infection in geriatric department of Xijing hospital from January 2014 to October 2017 were enrolled.Patients were divided into two groups:the observation group (with occult pneumonia,n=80)and the control group(without occult pneumonia,n =90).Clinical data of patients were collected,and clinical characteristics and related risk factors of occult pneumonia in elderly patients were analyzed.Results There was no statistically significant difference in the positive rate of sputum culture and the distribution of pathogenic bacteria between the two groups (P ＞ 0.05).Gram-negative bacteria predominated in pathogenic bacteria.The hospitalization time was longer in the observation group than in the control group[(17.3 ± 3.0) d vs.(10.3 ± 3.9) d,P ＜ 0.05].The mortality rate was higher in the observation group than in the control group(10.0 ％ vs.3.3 ％,P ＜ 0.05).The age was older in the observation group than in the control group[(87.0± 1.7) years vs.(82.0± 2.4) years,P ＜ 0.05].The incidences of diabetes,Alzheimer's disease,hypothyroidism and long-term bed rest were higher in the observation group than in the control group (P ＜ 0.05).Multivariate logistic regression analysis showed that age (OR =6.93),dementia (OR =4.32),hypothyroidism(OR =4.89) were independent risk factors for occult pneumonia (P ＜ 0.05).Conclusions The pathogenic bacteria in advanced elderly patients with occult pneumonia are mainly gram-negative bacteria.The positive rate of CT scan confirmed-occult pneumonia is much higher than that by chest X-ray.The advanced elderly patients with occult pneumonia have longer hospitalization time and higher mortality rates.Old age,senile dementia and hypothyroidism are independent risk factors for occult pneumonia in advanced elderly patients.