Background Researches showed that platelet-derived growth factor (PDGF) modulate the expression of matrix metalloproteinase/tissue inhibitor of metalloproteinase (MMP/TIMP) in cells,but the association of expression of MMP/TIMP in retinal pigment epithelial (RPE) cells and the dose and active time of PDGF is unclear.Objective This study was to observe the effects of PDGF on the expressions of MMP-2,MMP-9 and TIMP-1 in cultured RPE cells in vitro.Methods RPE cell line,ARPE-19,was calculated in vitro,and the cells were divided into 5 groups when they reached 70％-80％ confluence.Different concentrations (0,0.1,1,10,50 mg/L) of PDGF was added into the medium respectively for 36 hours,and the expressing levels of mRNA and protein of MMP-2,MMP-9 and TIMP-1 were detected by reverse transcription PCR (RT-PCR) and Western blot assay.In addition,RPE cells in PDGF group were treated with 10 mg/L PDGF for 24,36,48 hours respectively to detect the expressions of mRNA and protein of MMP-2,MMP-9 and TIMP-1 in the cells and to compare with the control group without PDGF.Results PDGF stimulated proliferation of RPE cells in a dose-and time-dependent manner.As the increase of the PDGF concentrations,the expression values of MMP-2 mRNA and MMP-9 mRNA in RPE cells were gradually elevated,with a statistically significant difference among various groups (MMP-2 mRNA:F=79.304,P=0.000;MMP-9 mRNA:F =8.465,P=0.003),and the expressions of MMP-2 mRNA and MMP-9 mRNA were significantly higher in the 1,10,50 mg/L PDGF groups compared with 0 mg/L PDGF normal control group (all at P＜0.05).Also,the expression values of MMP-2 and MMP-9 proteins in RPE cells were gradually elevated with the increase of PDGF concentrations,showing statistically differences among the groups (MMP-2:F=26.550,P=0.000;MMP-9:F=80.993,P=0.000).Compared with the 0 mg/L PDGF group,MMP-2 and MMP-9 expression levels in the 1,10,50 mg/L PDGF groups were significantly up-regulated (all at P＜ 0.05).However,the expression levels of TIMP-1 mRNA and protein group in the cells were not significantly different among various groups (mRNA:F =0.143,P =0.962 ; protein:F =1.955,P =0.178).The expression levels of M MP-2 mRNA,M MP-9 mRNA in the cells were increased in the PDGF group compared with the control group at different time points (MMP-2 mRNA:Ftime =83.250,P=0.002 ; MMP-9 mRNA:Ftime =6.785,P =0.019).Also,the expression values of MMP-2 and MMP-9proteins in RPE cells were increased in the PDGF group compared with the control group at different time points (MMP-2:Ftime =1 l.185,P =0.041 ; MMP-9:Ftime =968.413,P =0.000).The expression levels of MMP-2 and MMP-9 mRNAs and proteins were significant between the two groups at different time points (all at Pgroup =0.000;all at Ptime＜0.05).While the expression changes of TIMP-1 werc not significant between the two groups and among various time points (all at P＞0.05) Conclusions PDGF up-regulates MMP-2 and MMP-9 expressions in RPE cells in a dose-and time-dependent manner.But,PDGF dose not alter the expression of TIMP-1.These results indicate that PDGF disrupt the balance of MMP/TIMP,which may damage the extracellular matrix and therefore facilitate the migration of RPE cells in the pathogenesis of proliferative vitreoretinopathy.

The aim of this study is to study the damage effects of chronic hypoxia on medulla oblongata and to explore whether the damage is associated with oxidative stress and cell apoptosis. Adult male SD rats were randomly divided into two groups: control group and chronic hypoxia group. Medulla oblongata was obtained for the following methods of analyses. Nissl's staining was used to examine the Niss bodies of neurons in medullary respiratory related nuclei, biochemistry methods were utilized to examine oxidant stress damage induced by chronic hypoxia on medulla oblongata through measuring malondialdehyde (MDA) content and superoxide dismutase (SOD) activity, and RT-PCR technique was used to study the influence of apoptosis induced by chronic hypoxia on medulla oblongata through analyzing the levels of Bax mRNA and Bcl-2 mRNA. The results showed the optical densities of Nissl's staining in pre-BötC, NA, NTS, FN, and 12N were significantly decreased in chronic hypoxia group in comparison with that in control group (P < 0.05). In chronic hypoxia group, MDA level was significantly higher than that in the control group (P < 0.05), whereas SOD level had no significant difference between the two groups (P > 0.05). Bax mRNA expression had no obvious change and Bcl-2 mRNA expression significantly decreased in chronic hypoxia group in comparison with that in control group (P < 0.05). The results suggest that chronic hypoxia could bring about serious damage to medullary respiratory centers through aggravating oxidative stress and increasing cell apoptosis.
Animals ; Apoptosis ; Chronic Disease ; Hypoxia ; physiopathology ; Male ; Medulla Oblongata ; metabolism ; pathology ; physiopathology ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Respiratory Center ; metabolism ; pathology ; physiopathology ; Superoxide Dismutase ; metabolism

Pulmonary mucinous adenocarcinoma is a subtype of lung adenocarcinoma, among which invasive mucinous adenocarcinoma (IMA) is the most common subtype and is easily misdiagnosed as pneumonia. Its etiology and pathogenesis are unclear and may be related to gene mutations and other factors. Due to its relative rarity and few related studies, guidelines do not provide advices on its treatment. KRAS mutations are common in IMA patients, and Sotorasib may be effective against KRAS G12C mutated IMA. NRG1 fusion is considered to be an important driver of IMA, and afatinib may be effective in treating IMA with NRG1 fusion/rearrangement. PD-L1 expression is very low in IMA patients, while B7-H3 expression is high, so B7-H3 may be a potential immunotherapeutic target.

Objective To survey the prevalence of greenhouse farmer's lung and related risk factors in part of rural areas of Liaoning Province.Methods Using uniform scheme,procedures and questionnaire,a survey for 5420 farmers(2660 men and 2760 women)with complete data who work inside greenhouses was performed in Shenyang,Xinmin,Chaoyang,and Jinzhou between August 2006 and June 2009.Pulmonary function tests was performed for every active farmer.Results Greenhouse farmer's lung was diagnosed in 308 cases,205 men(66.55%,205/308)and 103 women(33.44%,103/308),a prevalence of 5.7%(308/5420).The prevalence rate of greenhouse farmer's lung in males was significantly higher than that in females(?2=39.93,P0.05).In the 308 cases,the number of patiernts presented with fever chill,cough/sputum,chest tightness/shortness of breath were 180(58.44%),192(62.34%),160(51.95%)respectively,and the number of crepitations,radiological changes,spirometry abnormalities and serum IgE antibodies(+)was 164(53.25%),153(49.68%),147(47.73%)and 136(44.16%)at the time of the study.62.34%(192/308)of patients with greenhouse farmer's lung were mild and 38.66%(116/308)were severe.Conclusion The total prevalence rate of greenhouse farmer's lung in part of rural areas of Liaoning Province was 5.7% and multiple risk factors were associated with the disease.