RESUMO
A novel 1,8-naphthalimide fluorescent probe (BNAS) containing 2-thiopheneethylamine moiety was designed and synthesized for analyzing the composition of N,N-dimethylformamide (DMF)/deionized water (H2O) mixtures. With the increase of DMF content, the fluorescence of the system was enhanced from dark to bright yellow-green. Taking 15% (volume) DMF content as the dividing point, the fluorescence intensity of the system at 535 nm showed two good linear relationships with the DMF content 1-15% and 15-99%, based on which the composition of the DMF/H2O mixtures with a volume ratio of 1/99-99/1 could be quickly and efficiently analyzed with high selectivity and sensitivity. BNAS can be applied in real sample assay and further be loaded onto filter paper to make a portable sensor. The mechanism of BNAS response to DMF/H2O composition was also explored.
RESUMO
OBJECTIVE: To observe the effects of mesenteric lymph drainage on the metabolism of red blood cell (RBC) in hemorrhagic shock (HS) rats following fluid resuscitation. METHODS: Eighteen male Wistar rats were randomly divided into sham group (n=6), HS group (n=6), HS + drainage group (n=6). After 1.5 hours of HS model prepared, the animals were given fluid resuscitation by lost blood plus equal volume of Ringer solution within 30 minutes in HS and HS + drainage groups, and mesenteric lymph drainage was performed after 1 hour of hypotension in HS + drainage group. At 3 hours after resuscitation or corresponding time, blood samples were obtained from abdominal aorta. Membrane suspensions of RBC prepared from part of whole blood samples were used to measure the activities of adenosine triphosphate ase (ATPase) and contents of ATP and lactic acid (LA), the intracellular fluid of RBC prepared from part of whole blood samples was used to determine the concentration of 2,3-diphosphoglyceric acid (2,3-DPG), Na(+) and K(+), plasma samples isolated from blood by centrifugation were used to determine the concentration of Na(+), K(+), Cl(-) and total Ca. RESULTS: Compared with sham group, the content of ATP (µmol/g), activity of Na(+)-K(+)-ATPase (µmol×mg(-1)×h(-1)) and Ca(2+)-ATPase (µmol×mg(-1)×h(-1)) in RBC membrane and total Ca (mmol/L) in plasma were decreased markedly (ATP: 6.698±0.938 vs. 10.670±1.466, Na(+)-K(+)-ATPase: 0.042±0.010 vs. 0.066±0.019, Ca(2+)-ATPase: 0.054±0.015 vs. 0.081±0.017, total Ca: 2.27±0.18 vs. 2.66±0.21, P<0.05 or P<0.01) in HS group, and the content of LA (mmol/g) in RBC and K(+) (mmol/L), Cl(-) (mmol/L) in plasma were increased observably in HS group (LA: 3.472±0.853 vs. 1.743±0.395, K(+): 5.83±0.34 vs. 5.23±0.37, Cl(-): 113.37±3.63 vs. 106.35±4.99, P<0.05 or P<0.01), there was no significant difference in term of the contents of 2,3-DPG (mmol/L: 2.196±0.609 vs. 2.590±0.574, P>0.05). Compared with HS group, the contents of 2,3-DPG (4.459±0.900) and ATP (8.859±1.189), the activities of Na(+)-K(+)-ATPase (0.089±0.022), Ca(2+)-ATPase (0.082±0.020) of RBC were increased in HS + drainage group, and the level of LA (2.060±0.810) was decreased observably (P<0.05 or P<0.01), there were no significant differences in the other indices. CONCLUSIONS: The results indicate that shock mesenteric lymph drainage plays an important role in improving the metabolism of RBC in HS rats following fluid resuscitation, subsequently, may preserve the structure and function of RBC.