[The expressions of VEGF and VEGFR signaling pathway in the bone marrow mononuclear cells with chronic mountain sickness].

Objective: This study was aimed at investigating the levels and relationships of vascular endothelial growth factor (VEGF) and its receptor(VEGFR) in the bone marrow mononuclear cells (MNC) of chronic mountain sickness (CMS). Methods: A total of 34 patients with CMS and 30 controls residing at altitudes of 3 000-4 500 m were recruited for this study. The levels of VEGF, VEGFR1 and VEGFR2 in bone marrow MNC were detected by flow cytometry technique and RT-qPCR. Results: The percentage of VEGFR2 positive cells in the bone marrow MNC of CMS were higher than that of the controls[20.7% (8.1%, 67.6%) vs 8.1% (2.2%, 14.9%), P<0.05], but that of VEGFR1-positive and VEGF-positive were similar in CMS and controls. The mRNA levels of VEGFR2 were higher in the bone marrow MNC of CMS than in the controls[1.7(1.0, 5.1) vs 1.0(0.4, 2.7), P<0.05], while VEGF and VEGFR1 mRNA levels were similar between the two groups. The percentage of VEGFR2 positive cells in CMS were significantly correlated with hemoglobin (r=0.453, P=0.007) and the percentage of VEGF-positive cells (r=0.373, P=0.030). Conclusions: Bone marrow MNC of CMS may show enhanced activity of the VEGF-VEGFR2 pathway, and it appears to be involved in the pathogenesis of CMS.

[Correlation between EGLN1 gene, protein express in lung tissue of rats and pulmonary artery pressure at different altitude].

OBJECTIVE: To investigate the correlation between pulmonary artery pressure (PAP) and the expression level of Egl nine homologue 1 (EGLN1) gene or its protein in lung tissue of rats at different altitudes. METHODS: Totally 121 male Wistar rats were randomly divided into low altitude group (n=11), moderate altitude group and high altitude group, the rats in moderate altitude and high altitude group were further divided into 1(st) day, 3(rd) days, 7(th) days, 15(th) day and 30(th) day group according to the exposure time to hypoxic environment, each group 11 rats. The low altitude group, the PAP of rats were determined by physiological signal acquisition system, and tissue samples were collected in liquid nitrogen container for storage at an altitude of 498 m area. Moderate altitude group rats were placed in altitude of 2 260 meters of natural environment, 5 high altitude groups rats were placed in the hypobaric hypoxic chamber, simulating altitude of 4 500 meters. The PAP of rats in moderate altitude group and high altitude group were also determined by physiological signal acquisition system, and tissue samples were collected when rats were exposed to hypoxia at 1(st), 3(rd), 7(th), 15(th) and 30(th) day; Western blot was used to determine expression levels of EGLN1 protein, and person correlation analysis was used to analyze whether the protein was related to the formation of pulmonary arterial hypertension (PH) under hypoxia. Real-time quantitive PCR method determined expression levels of EGLN1 mRNA in lung tissues, and the relative expression method was used to analyze PCR data, and finally assess whether the EGLN1 gene was the initial cause of the formation of PH during hypoxia. RESULTS: The mean PAP of rats was (20.0±3.2) mmHg (1 mmHg=0.133 kPa) in low altitude group; in moderate altitude group, mean PAP began to increase slightly when rats were exposed to hypoxia on the 15(th) day and reached at (22.7±4.1) mmHg on hypoxic 30(th) day, but compared with the low altitude group, there was no statistical difference (P> 0.05); the mean PAP of rats in high altitude group began to rise on the 7(th) day (28.7±7.7) mmHg, which was higher than that in low altitude group (P<0.05), and significantly increased to (42.3±9.1) mmHg (P<0.001) on hypoxic 30(th) day; it was significantly proportional with exposure to hypoxic time, and compared to low altitude group and moderate altitude group, there was significant difference (P<0.05). EGLN1 protein expression in the lung tissue of rats had no significant difference between the low altitude group and moderate altitude group, and its expression level in the high altitude group were significantly decreased, furthermore, the expression level decreased with the increase of hypoxia exposure time (P<0.05); PAP and EGLN1 protein expression levels showed a negative correlation (r=-0.662). The transcription level of mRNA EGLN1 in high altitude group was significantly increased under hypobaric hypoxia, it was 72 times more than that of the moderate altitude group, and nearly 300 times than that of the low altitude group, respectively (both P<0.001=. CONCLUSION: EGLN1 gene expression in lung tissue of rat is affected by hypoxia, the expression level increases with the increase of the altitude; but the protein expression level, in contrast with gene expression level, is decreased with the increase of altitude and is significantly negatively correlated with mean PAP.

[Study on photodegradation kinetics of lomefloxacin hydrochloride aqueous solution].

AIM: To investigate the photodegradation kinetic characteristics of lomefloxacin hydrochloride aqueous solution. METHODS: The HPLC method was used to determine the photodegradation kinetic parameters of lomefloxacin hydrochloride aqueous solution (10 micrograms.mL-1) under various pH buffer solutions, various ionic strength of different ions and various dielectric constant conditions. RESULTS: With comparative regression analysis of linear fit, the photodegradation kinetic order of lomefloxacin hydrochloride aqueous solution was determined as n = 1. The lomefloxacin hydrochloride aqueous solution is most unstable at pH 5.08-9.40 and is relatively stable at pH 2.02-5.08 and 9.40-11.10. The higher the ionic strength in lomefloxacin hydrochloride aqueous solution, the higher the photodegradation kinetic rate constant is. The chloride ion has important effect on photodegradation in aqueous solution of lomefloxacin and results in producing chlorine derivative as the highest photodegradation product. As the dielectric constant of solution increased, the photodegradation kinetic rate constant was also increased. CONCLUSION: It was found that the photodegradation of lomefloxacin followed apparent first-order kinetics. The photodegradation kinetic rate was affected by pH remarkably and showed positive correlation with ionic strength and dielectric constant.

[Degradation of liquid preparations of four fluoroquinolones by factorial experiment. ].

The effects of light, pH and ionic strength on the degradation of four fluoroquinolones (norfloxacin, NFX; ofloxacin, OFX; ciprofloxacin, CPX; lomefloxacin, LEMX) solutions were studied. Using 2(3) factorial experiment and F test, it was confirmed that the degradation of NFX, OFX, CPX and LEMX was affected very markedly by light, but almost not affected by the ionic strength of the solution. The degradation of OFX and CPX was affected very markedly by pH, but the degradation of NFX and LEMX was almost not affected by pH. The degradation of OFX and CPX was affected very markedly by the combined action of light and pH, but the degradation of NFX and LEMX was almost not affected by the combined action of light and pH.