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@#Objective To compare and analyze the effect of myocardial protection between HTK and del Nido cardioplegia solutions in neonates with surgeries for transposition of the great arteries. Methods The clinical data of 208 neonates with complete transposition of the great arteries in our institution from 2014 to 2020 were retrospectively analyzed. According to the cardioplegia solutions utilized in the operations, the patients were divided into two groups: a HTK group and a del Nido group. Propensity score matching was conducted to eliminate the biases. The cardiopulmonary bypass time, aortic cross-clamping time, total amount of cardioplegia solutions, transfusion frequency of cardioplegia, ICU stay time, mechanical support time, inotropic score, hospital stay, left ventricular ejection fraction, N-terminal proBNP and troponin I were compared and analyzed between the two groups after matching. Results After 1:1 propensity score matching, a total of 54 patients were analyzed with 27 patients in each group. In the HTK group, there were 22 males and 5 females with a median age of 7.0 (2.0, 11.0) d. In the del Nido group, there were 23 males and 4 females with a median age of 8.0 (3.0, 11.0) d. A total of 3 children died after the surgery: 2 (7.4%) patients in the HTK group and 1 (3.7%) patient in the del Nido group. There was no significant difference in hospital mortality between the two groups (P=1.000). The total amount of cardioplegia solutions in the HTK group was significantly higher than that of del Nido group (P<0.001). Transfusion frequency of cardioplegia in del Nido group was significantly higher than that of the HTK group (P=0.043). There was no significant difference in the postoperative ICU time, mechanical support time, length of hospital stay, inotropic score, left ventricular ejection fraction, N-terminal B-type natriuretic peptide precursor or troponin I between the two groups (P>0.05). Conclusion For neonates with surgeries for complete transposition of the great arteries, HTK cardioplegia solutions can provide effective and safe myocardial protection, which is similar to del Nido cardioplegia solutions.
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Objective To study the short-term variation patterns of graft viscosity after anterior cruciate ligament reconstruction (ACLR) surgery. Methods Six male New Zealand rabbits were selected. The ACLR animal model of unilateral knee was made with Achilles tendon as the graft. The experimental rabbits were euthanized 15 days after ACLR surgery, with removal of the graft, healthy anterior cruciate ligament (ACL) and Achilles tendon. The cross-sectional area and viscosity coefficient of the graft were measured, and the creep experiments were carried out under equilibrium conditions of 0.1 MPa and 1 MPa, respectively. The viscosity coefficent was calculated. Variation patterns of graft viscosity were summarize. The grafts were compared with healthy ACL. Results The cross-sectional area of the graft increased slowly within 15 days after ACLR surgery. The viscosity of ACL and graft changed nonlinearly. The viscosity coefficient was quite different under different stresses. The viscosity coefficient of the graft decreased with the time after ACLR surgery, which was more obviously under the condition of low stress. Conclusions The results are helpful to guide the implementation of early postoperative rehabilitation plan after ACLR surgery .
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<p><b>OBJECTIVE</b>To prepare pravastatin sodium-loaded chitosan microspheres to allow sustained drug release.</p><p><b>METHODS</b>The drug-loaded chitosan microspheres were prepared by using genipin as the cross-linker. The influences of molecular weight of chitosan, volume ratio of oil and water, reaction temperature, and stirring speed on the formation of chitosan microspheres were investigated. The morphology of the microspheres was observed using scanning electron microscopy. The encapsulation efficiency, swelling ratio under different pH conditions, and in vitro drug release were measured.</p><p><b>RESULTS</b>The in vitro release of pravastatin sodium could last for at least 31 days. The drug release rate varied with the reaction condition. The drug entrapment efficiency of the microsphere was 54.7%. The optimal processing conditions were as follows: chitosan viscosity of 200-400 mPa·s, oil-water proportion of 10:1, stirring speed of 850 r/min, and reaction temperature at 40 degrees celsius;.</p><p><b>CONCLUSION</b>The pravastatin sodium-loaded microspheres show good sustained drug release property, and the drug release rate can be modified by controlling the cross-linking time.</p>
Subject(s)
Chitosan , Cross-Linking Reagents , Delayed-Action Preparations , Iridoids , Microscopy, Electron, Scanning , Microspheres , Pravastatin , ChemistryABSTRACT
<p><b>OBJECTIVE</b>To prepare a pH fluorescence probe based on styrylcyanine dyes for live cell imaging.</p><p><b>METHODS</b>The Probe 1 was prepared by reaction of 4-pyridinecarboxaldehyde with 1,1,2-trimethylbenz[e]indole. The influence of pH on the fluorescent properties was examined, and the cell viability was examined using cell counting kit-8. The Probe 1 was used as a pH fluorescence probe in living cell.</p><p><b>RESULTS</b>Probe 1 emitted green fluorescence under neutral and basic conditions but orange fluorescence under acid condition. Probe 1 selectively stained the cytoplasmic regions of living cells without significantly affecting the cell viability.</p><p><b>CONCLUSION</b>The pH-sensitive fluorescent probe prepared based on styrylcyanine possesses good ability of cell membrane permeation for live cell fluorescent imaging.</p>