Objective:To develop a method for the quantitative determination of ambrisentan. Methods: 1 H NMR spectra were obtalned with a Bruker AscendTM 400 superconducting NMR spectrometer. For each sample, DMSO-D6 was used as the solvent, the pulse width was 10. 0 μs, the delay time was 5 s and the scanning time was 16. Results: The proton peaks of ambrisentan at δ6. 16 ppm and maleic acid atδ6. 28 ppm were used as the quantitative peaks. The linear regression equation of peak area and quality ratio was Y=0. 140 7X+0. 034 8 with the correlation coefficient of 0. 999 4. RSD was 0. 2%(n=6)in the repeated experiments. The absolute content of ambrisentan reference substance was 99. 9%. Conclusion: The results showed that 1 H NMR can be used in the quantitative determination of ambrisentan without reference substance. The method is reliable, rapid, accurate and simple.

Objective To investigate the change of aquaporin 2 (AQP2) mRNA and protein levels in renal collecting duct of SD rats after hypoxin caused by rising of the altitude to 4600 m. Methods Forty male SD rats were randomly divided into 4 groups (24 h, 48 h, 72 h and 1 week group), and 10 rats in Xining city were used as control group. All the 40 SD rats were transported to Kekexili Natural Reservation areas (4600 m) in Qinghai province. Rats of four experimental groups were sacrificed and renal tissue samples were harvested at different time point respectively, the control group rats were treated in Xining city (2260 m) as well. The concentration of plasma antidiuretic hormone (ADH) was measured by radioimmunity method. The expression of AQP2 mRNA and proteins was evaluated by real-time fluorescent quantitative-PCR, Western blot and immunofluorescence assay. Results The concentration of plasma ADH was decreased at 24 h and was only 28.5% of that of control group, reaching the lowest concentration at 48 h [(86.94±6.49) μg/L vs (302.5±310.48) μg/L], then it increased gradually and was similar to the control group at 7 d [(306.46±11.14) μg/L vs (302.53±10.48)μg/L, P＞ 0.05]. There were significant differences of the control group with 24 h, 48 h and 72 h groups, respectively[(302.53± 10.48) μg/L vs (142.46±10.57)μg/L, (86.94±6.49)μg/L, (169.65±11.15) μg/L respectively, P＜0.01]. The change of AQP2 gene expression level was consistent with the change of ADH. It was decreased at the begining when exposure to altitude and it reached its lowest level at 48 h. It was then returned to high level similarly to that of the control group at 7 d (0.09±0.01 vs 0.09± 0.008, P＞0.05 ). There were significant differences of the control group with 24 h, 48 h and 72 h group, respectively (0.09±0.008 vs 0.04±0.005, 0.03±0.002, 0.04±0.003 respectively, P＜0.01 ). Conclusions AQP2 expression in the renal collecting duct of SD rats is altered over the period exposed to altitude. It is decreased in the early hypoxia period, and is increased in later period. This change may be related to the intensity of hypoxia, which is mediated by a potential adaptation mechanisms against hypoxia caused by high altitude.

OBJECTIVE:To establish a method for the determination of 7 residual solvents(ethanol,n-hexane,benzene,tolu-ene,xylene,styrene,divinylbenzene)in Liuwei dihuang glycoside. METHODS:The column was DB-624 capillary column,carri-er gas was nitrogen,flow rate was 5.0 ml/min;detector was a hydrogen flame ionization detector with temperature of 250 ℃(pro-grammed temperature);equilibrium temperature was 80 ℃,sample loop temperature was 90 ℃,and transfer line temperature was 100 ℃;the equilibrium time of vial heating was 30 min,sample loop filling time was 0.05 min,injection time was 1.0 min;the carrier gas pressure was 95 kpa,and the vial pressure was 60 kpa. RESULTS:The linear range was 25-500 μg/ml for ethanol(r=0.998 7),0.025-10μg/ml for n-hexane(r=0.998 8),0.025-10μg/ml for benzene(r=0.999 9),0.1-40μg/ml for toluene(r=1.000 0),0.25-100 μg/ml for xylene(r=0.999 9),0.5-500 μg/ml for styrene(r=1.000 0) and 0.5-500 μg/ml for divinylbenzene (r=1.000 0);RSDs of precision,stability and reproducibility tests were lower than 4%;recoveries were 99.60%-102.70%(RSD=1.08%,n=9),90.70%-100.30%(RSD=4.51%,n=9),100.10%-109.80%(RSD=3.82%,n=9),99.50%-110.00%(RSD=4.40%,n=9),100.00%-109.10%(RSD=3.50%,n=9),93.40%-102.30%(RSD=3.73%,n=9) and 99.70%-101.70%(RSD=0.79%,n=9),respectively;the low limits of detection were 1.000,0.025,0.025,0.025,0.100,0.025,0.250 μg/ml respectively. CONCLUSIONS:The method is simple,stable and reproducible,and can be used for the determination of residual solvents(etha-nol,n-hexane,benzene,toluene,xylene,styrene,divinylbenzene)in Liuwei dihuang glycoside.

OBJECTIVE:To establish a method for the simultaneous determination of 5 unsaturated fatty acids in Perilla oil cap-sule. METHODS:With the reference material of α-linolenic acid methyl ester,GC was used to determine and calculate the relative correction factors of α-linolenic acid methyl ester with methyl palmitate,methyl stearate,methyl oleate and linoleic acid methyl es-ter,and the correction factors were used to calculate the contents of 5 unsaturated fatty acids;the column was Agilent Innowax cap-illary column,the detector was FID,the inlet temperature was 230 ℃,the detector temperature was 250 ℃,the gas flow rate was 20 ml/min(nitrogen),40 ml/min(hydrogen)and 350 ml/min(air),split ratio was 30 to 1,the column temperature was 190 ℃, and injection volume was 1 μl. RESULTS:The linear range was 0.018-0.792 μg(r=0.9994)for methyl palmitate,0.0016-0.0176μg(r=0.9993)for methyl stearate,0.0056-0.2464 μg(r=0.9999)for methyl oleate,0.003-0.132 μg(r=0.9990)for linoleic acid methyl ester and 0.018-0.792 μg(r=0.9998) for α-linolenic acid methyl ester;RSDs of precision,stability and reproducibility tests were lower than 5%;recoveries were 98.990%-101.70%(RSD=0.720%,n=6) for methyl palmitate,99.599%-100.699%(RSD=0.368%,n=6) for methyl stearate,98.996%-101.680%(RSD=1.240%,n=6) for methyl oleate,99.813%-100.963%(RSD=0.434%,n=6)for linoleic acid methyl ester and 97.185%-99.602%(RSD=0.874%,n=6)for α-linolenic acid methyl es-ter. CONCLUSIONS:The method is simple and stable with good reproducibility,and can be used for the simultaneous determina-tion of methyl palmitate,methyl stearate,methyl oleate,linoleic acid methyl ester,α-linolenic acid methyl ester in Perilla oil cap-sule.

Objective:To investigate the expression characteristics of high mobility group box 1 protein (HMGB1) in rat models of deafferentation pain induced by posterior root injury of spinal nerves, and its relation with neuroinflammation.Methods:Sixty SD rats were divided into a blank control group ( n=10) and a model group ( n=50) according to random number table method. Neuropathic pain rat models in the model group were established by cutting the posterior root of C 5-T 1 spinal nerve, while rats in the control group were performed the same operation without cutting the posterior root of C 5-T 1 spinal nerve. Three, 7, 10, 14, and 21 d after modeling, behavioral changes, including spontaneous pain scale scores, mechanical antagonistic pain threshold, and autophagy scale scores, were evaluated in the two groups of rats. Immunohistochemical staining was used to detect the HMGB1, ionized calcium binding adapter molecule 1 (IBA-1) and phosphorylated nuclear factor κB (pNF-κB) positive cells in the spinal cord of the two groups. Western blotting was used to detect the protein expressions of HMGB1, toll-like receptor (TLR)2 and pNF-κB in the spinal cord of the two groups. Results:(1) The scores of spontaneous pain scale and autophagy scale 14 and 21 d after modeling were significantly higher than those 3, 7 and 10 d after modeling ( P<0.05), and those 21 d after modeling were significantly higher than those 14 d after modeling ( P<0.05). (2) Immunohistochemical staining showed that HMGB1, IBA-1 and pNF-κB all expressed in the spinal cord tissues of rats in the model group 3 d after modeling, and the number of positive cells in the dorsal horn of the spinal cord on the injured side became larger with prolongation of exposure time, and that was obviously larger as compared with that on the opposite side; in the spinal cord tissues of the blank control group, the number of positive cells in the spinal dorsal horn area was small, and there was no significant difference in the number of positive cells in the spinal dorsal horn area on both sides. (3) Western blotting showed that, as compared with those in the blank control group, HMGB1, TLR2 and pNF-κB protein expressions in the spinal cord tissues of the model group were significantly increased 3, 7, 10, 14 and 21 d after modeling ( P<0.05), and which showed an increasing trend with prolongation of exposure time. Conclusion:The gradual increase in HMGB1 expression in the local spinal cord of rats with deafferentation pain leads to HMGB1/TLR2/NF-κB pathway high expression and activation of microglia cells, which induces the occurrence of local neuroinflammation in the spinal cord and eventually results in pain behavioral changes.

The accumulation and spread of prion-like proteins is a key feature of neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, or Amyotrophic Lateral Sclerosis. In a process known as 'seeding', prion-like proteins such as amyloid beta, microtubule-associated protein tau, α-synuclein, silence superoxide dismutase 1, or transactive response DNA-binding protein 43 kDa, propagate their misfolded conformations by transforming their respective soluble monomers into fibrils. Cellular and molecular evidence of prion-like propagation in NDs, the clinical relevance of their 'seeding' capacities, and their levels of contribution towards disease progression have been intensively studied over recent years. This review unpacks the cyclic prion-like propagation in cells including factors of aggregate internalization, endo-lysosomal leaking, aggregate degradation, and secretion. Debates on the importance of the role of prion-like protein aggregates in NDs, whether causal or consequent, are also discussed. Applications lead to a greater understanding of ND pathogenesis and increased potential for therapeutic strategies.
Humans ; Prions ; Neurodegenerative Diseases/pathology* ; Amyloid beta-Peptides ; Alzheimer Disease ; alpha-Synuclein ; tau Proteins ; Parkinson Disease

Objective    To summarize the early outcomes of totally thoracoscopic minimally invasive aortic valve replacement (AVR) and double valve replacement (DVR). Methods    The clinical data of patients who underwent totally thoracoscopic minimally invasive AVR or DVR in Guangdong Provincial People’s Hospital from April 2020 to January 2021 were retrospectively analyzed. The patients were divided into an AVR group and a DVR group according to the surgical method, and the clinical data of the two groups were compared. Results    Finally 22 patients were enrolled, including 14 males and 8 females with an average age of 50.0±11.2 years at operation. Eight patients were degenerative disease, 8 were rheumatic heart disease combined with valvular disease, and 6 were bicuspid aortic valve. Out of the 22 patients, 16 underwent AVR alone, and 6 underwent DVR. All patients completed the operation successfully, and there was no death. Perivalvular leakage during surgery occurred in 2 patients. The average cardiopulmonary bypass time was 187.0±39.9 minutes, and aortic cross-clamping time was 117.0 (99.0, 158.0) minutes. Duration of mechanical ventilation and intensive care unit stay was 9.5 (4.8, 18.3) hours and 41.0 (34.0, 64.0) hours, respectively. The volume of chest drainage at the first 24 hours after surgery was 214.0±124.6 mL, and the postoperative hospital stay was 5.5 (4.0, 8.3) days. The cardiopulmonary bypass time and aortic cross-clamping time in the DVR group were longer than those in the AVR group, and the volume of chest drainage at 24 hours after surgery was more than that in the AVR group, with a statistical difference (P<0.05). Echocardiography before hospital discharge showed paravalvular leakage in 1 patient. There was no death during follow-up of 5.9±3.0 months. Conclusion    The early outcome of totally thoracoscopic minimally invasive AVR and DVR is satisfactory, and the approach of surgery is worth exploring.

Objective To examine the safety, efficacy and durability of totally endoscopic minimally invasive (TEMI) mitral valve repair in Barlow’s disease (BD). Methods A retrospective study was performed on patients who underwent mitral valve repair for BD from January 2010 to June 2021 in the Guangdong Provincial People’s Hospital. The patients were divided into a MS group and a TEMI group according to the surgery approaches. A comparison of the clinical data between the two groups was conducted. Results A total of 196 patients were enrolled, including 133 males and 63 females aged (43.8±14.9) years. There were 103 patients in the MS group and 93 patients in the TEMI group. No hospital death was observed. There was a higher percentage of artificial chordae implantation in the TEMI group compared to the MS group (P=0.020), but there was no statistical difference between the two groups in the other repair techniques (P>0.05). Although the total operation time between the two groups was not statistically different (P=0.265), the TEMI group had longer cardiopulmonary bypass time (P<0.001) and aortic clamp time (P<0.001), and shorter mechanical ventilation time (P<0.001) and postoperative hospitalization time (P<0.001). No statistical difference between the two groups in the adverse perioperative complications (P>0.05). The follow-up rate was 94.2% (180/191) with a mean time of 0.2-12.4 (4.0±2.4) years. Two patients in the MS group died with non-cardiac reasons during the follow-up period. The 3-year, 5-year and 10-year overall survival rates of all patients were 100.0%, 99.2%, 99.2%, respectively. Compared with the MS group, there was no statistical difference in the survival rate, recurrence rate of mitral regurgitation, reoperation rate of mitral valve or adverse cardiovascular and cerebrovascular events in the TEMI group (P＞0.05). Conclusion TEMI approach is a safe, feasible and effective approach for BD with a satisfying long-term efficacy.

Objective    To investigate the predictive value of right atrial myocardial fibrosis in the prognosis of isolated tricuspid regurgitation surgery after left heart valve surgery. Methods    The patients who underwent tricuspid valvuloplasty by the same operator in Guangdong Provincial People's Hospital from April 2016 to August 2021 due to long-term isolated severe tricuspid regurgitation after left heart valve surgery were included in the study. According to the degree of right atrial myocardial fibrosis, the patients were divided into three groups: a mild group, a moderate group, and a severe group. The clinical data of these patients were compared and analyzed. Results    A total of 75 patients were enrolled, including 16 males and 59 females with an average age of 57.0±8.4 years. There were 30 patients in the mild group, 29 patients in the moderate group and 16 patients in the severe group. In terms of the preoperative data, there were statistical differences in cardiac function grade, right atrial diameter, tricuspid incompetence area among the three groups (P<0.05). In terms of the postoperative data, there were statistical differences among the three groups in the cardiopulmonary bypass time, mechanical ventilation time, ICU monitoring time, complication rate and mortality (P<0.05). Further pairwise comparison showed that, compared with the mild group, the severe group had longer mechanical ventilation time (P=0.024), longer ICU monitoring time (P=0.003) and higher incidence of postoperative complications (P=0.024), while the moderate group had no statistical difference in all aspects (P>0.05); compared with the moderate group, the severe group had longer ICU monitoring time (P=0.021) and higher incidence of complications (P=0.006). Conclusion    The early outcome of tricuspid valvuloplasty in patients with isolated tricuspid regurgitation after left heart valve surgery with severe right atrial myocardial fibrosis is worse than that in the patients with mild and moderate fibrosis, suggesting that the degree of myocardial fibrosis in the right atrium can be a predictor of the effect of tricuspid regurgitation surgery and a judgement indicator of the surgery timing.

Objective To research the procedure for creating an animal model of mitral regurgitation by implanting a device through the apical artificial chordae tendineae, and to assess the stability and dependability of the device. Methods Twelve large white swines were employed in the experiments. Through a tiny hole in the apex of the heart, the artificial chordae tendineae of the mitral valve was inserted under the guidance of transcardiac ultrasonography. Before, immediately after, and one and three months after surgery, cardiac ultrasonography signs were noted. Results All models were successfully established. During the operation and the follow-up, no swines died. Immediately after surgery, the mitral valve experienced moderate regurgitation. Compared with preoperation, there was a variable increase in the amount of regurgitation and the values of heart diameters at a 3-month follow-up (P<0.05). Conclusion In off-pump, the technique of pulling the mitral valve leaflets with chordae tendineae implanted transapically under ultrasound guidance can stably and consistently create an animal model of mitral regurgitation.