ABSTRACT
Objective:To evaluate the effect of 2-aminoethoxydiphenyl-borate (2-APB) on cardiac dysfunction in arsenic poisoning rats by stratified strain technique.Methods:Thirty-two 12-week-old SD rats were randomly divided into control group ( n=8) and arsenic exposure group ( n=24). After 12 weeks of arsenic exposure, arsenic exposure group was divided into three groups: natural recovery group ( n=8), low-dose intervention group (n=8) and high-dose intervention group ( n=8). The rats were treated with 2-APB for 21 days. After the last administration, the routine parameters and the layered strain parameters were measured by ultrasonic instrument. Then the rats were killed and their blood and myocardial samples were obtained. The levels of serum creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were tested, and the morphological changes of cardiomyocytes were observed by HE staining. Results:Left ventricular ejection fraction (LVEF), left ventricular short axis shortening (LVFS), global circumferential strain of subendocardial myocardium (GCS-endo), global circumferential strain of middle myocardium (GCS-mid), global circumferential strain of subepicardial myocardium (GCS-epi) and circumferential strain rate of left ventricular segments (SrC) in the natural recovery group were lower than those in the control group ( P<0.05), while serum CK-MB and LDH were higher than those in the control group ( P<0.05). Some ultrasonic parameters and biochemical indexes in the low and high dose intervention groups were improved in varying degrees compared with the natural recovery group ( P<0.05). The correlation between GCS-endo and CK-MB was the highest ( r=-0.931, P<0.05). Myocardial HE staining showed that the degree of myocardial cell swelling and necrosis were reduced, and erythrocyte exudation was reduced in the low and high dose intervention groups compared with the natural recovery group. Conclusions:The stratified strain technique can be used to evaluate the protective effect of 2-APB on cardiac dysfunction in arsenic poisoning rats, and GCS-endo may be one of its sensitive indexes.
ABSTRACT
Objective To study the application of extrusion method in inducing liposome membrane fusion or membrane component mixing,and to investigate the effect of different extrusion conditions on liposome membrane fusion rate.Methods N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) phosphatidylethanolamine (N-NBD-PE) and N-(lissamine rhodamine B sulfonyl) phosphatidylethanolamine (N-Rh-PE) labeled 1,2-dioleoyl lecithin (DOPC) liposomes and non-fluorescently labeled DOPC monolayer liposomes were mixed and extruded.The fluorescence changes before and after the extrusion of the mixed liposomes were observed using laser scanning confocal microscope,and the membrane fusion rate of the mixed liposomes was calculated by fluorescence resonance energy transfer method.Besides,the effects of extrusion times,extrusion pressure and temperature on the fusion rate of liposome membrane were studied.Results The results of laser scanning confocal microscopy showed that the distribution density and intensity of the green fluorescence of N-NBD-PE increased significantly after the extrusion of fluorescently labeled and non-fluorescent labeled DOPC liposomes,which confirmed membrane fusion.After 75 times of extrusion treatments,the liposome membrane fusion rate can reach 26％.The number of extrusions,extrusion pressure and temperature had a significant effect on the fusion rate of the liposome membrane.The higher the number of the extrusions,the smaller the extrusion pressure and the higher the efficiency of the liposome membrane fusion were at physiological temperature.Conclusions Extrusion method can induce liposome membrane fusion and membrane component mixing,and the prepared liposome has a narrower particle size distribution,which is expected to be a new method to induce the bilayer membrane fusion of liposome or lipid vesicle.
ABSTRACT
Objective To investigate the role of individual dental stent on taste protection in the patients with primary nasopharyngeal carcinoma.Methods Firstly,dosimetric evaluation of the tongue under the circumstance of 10 pairs of patient wearing dental stent or not was done.Secondly,a total of 61 patients were randomized into two arms:29 were in the trial arm and 32 in the control arm.The patients wore dental stent during radiotherapy in trial group,but not in control group.The endpoint was taste dysfunction before radiotherapy,every week during radiotherapy till the completion of radiotherapy,and followed up six months after radiotherapy.Results The mean dose of tip of tongue,body of tongue,base of tongue for patient with dental stent or not were (394.43±24.01) cGy,(986.35±77.15) cGy,(4 401.16±179.01) cGy and (677.03± 110.05) cGy,(2 418.19±414.18) cGy,(4 878.67±387.45) cGy (P value were 0.031,0.007 and 0.284,respectively) separately.By the completion of the radiotherapy,there were 9 (31.03 ％) patients suffering from a taste dysfunction in the trial group and 25 (78.13 ％) in the control group (P ＜ 0.001).Conclusions Individual dental stent has a potential tendency to relieve the taste impairment by reducing the irradiation dose of tongue.