BACKGROUND:The utilization of miniscrews for assisting in molar distalization with clear aligners is a commonly adopted clinical approach.However,treatment outcomes may be influenced by the implantation position of miniscrew and the hooks in various tooth location.OBJECTIVE:To analyze the biomechanical effects of hooks at different tooth positions and the assistance of buccal and palatal miniscrews in distalizing molars with clear aligners by using the finite element method.METHODS:By integrating volunteer cone beam CT and Itero intraoral scan data,high-precision finite element models were constructed to simulate the combined use of miniscrews and hooks to assist in the distalization of the maxillary first and second molars with clear aligners,aiming for a designed distalization magnitude of 0.2 mm.Four conditions were established based on the placement of buccal or palatal miniscrews,as well as the located of hooks at the canine or first premolar.The buccal anchorage screw was used in combination with hooks on the buccal side of the canine;the buccal anchorage screw was used in combination with hooks on the buccal side of the first premolar;the palatal anchorage screw was used in combination with hooks on the lingual side of the canine,and the palatal anchorage screw was used in combination with hooks on the lingual side of the first premolar.Analysis using ANSYS software was conducted to evaluate the three-dimensional displacement trends of maxillary teeth and the maximum equivalent stress on the periodontal ligament under each condition.RESULTS AND CONCLUSION:(1)Regardless of whether hooks were placed on canines or first premolars,palatal miniscrews had been shown to enhance the distal movement of maxillary molars and reduce the mesial movement of premolars as well as the labial tipping tendency of anterior teeth,compared to buccal miniscrews.The maximum equivalent stress in the periodontal ligament of molars was increased,while that of anterior teeth was decreased.(2)Regardless of whether the miniscrews were located on the buccal or palatal side,compared with hooks at the first premolar,when hooks were done at the canine,the labial inclination trend of the anterior teeth was reduced,the distal movement of the molars was reduced,the mesial movement of the premolars was increased,and the maximum equivalent stress of the molar and the periodontal membrane of the anterior teeth was reduced.(3)Regardless of whether miniscrews were located on the buccal or palatal side,and the hooks were located on the canine or the first premolar,the molar could not achieve overall movement.(4)The results show that clear aligner combined with palatal miniscrews and hooks at the first premolar are more conducive to improving the efficiency of maxillary molar distalization,but attention should be paid to protecting the anterior tooth miniscrews and molar torque control;clear aligner combined with palatal miniscrews and hooks at the canine is more conducive to reducing the labial tipping tendency of anterior teeth,but the efficiency of molar distalization will be relatively reduced.

Objective To explore the clinical significance of pulse pressure variability(PPV)in early prevention and diagnosis of prostate resection syndrome by observing the changes in PPV during transurethral resection of the prostate.Methods Eighty patients undergoing transurethral resection of the prostate(TURP)under general anesthesia from March to April 2023 were randomly divided into a control group and an observation group,with 40 patients in each group.The control group underwent routine monitoring of invasive blood pressure,while the observation group continued to monitor PPV in addition to invasive blood pressure monitoring.Observe and record the hemodynamic parameters,electrolyte Na+,K+,CL-,Changes in hemoglobin(Hb)and hematocrit(Hct),recording surgical time,intraoperative lavage fluid dosage,and occurrence of dilutive hyponatremia(TURS).Results One patient in the observation group experienced two unexplained drops in blood pressure and heart rate during surgery,and was diagnosed with TURS based on blood gas analysis.Among them,the observation group showed a decreasing trend in PPV with the prolongation of surgery time.PPV gradually decreased at 45～60 minutes after surgery,and at 90 minutes after surgery,PPV decreased significantly compared to preoperative levels.Among them,6 patients had a 50%decrease in PPV compared to preoperative levels.For patients with significantly reduced PPV,immediate treatment was given 10～20 mg of furosemide and 10 mg of dexamethasone.By the end of surgery,PPV had basically recovered to preoperative levels.Both groups of patients showed varying degrees of decrease in Na+,K+,Hct,and Hb levels.Conclusions PPV can reflect the volume status of patients.When PPV decreases by more than 50%compared to preoperative levels and there are unexplained hemodynamic changes and abnormal clinical manifestations during surgery,it is necessary to be vigilant and handle them promptly to reduce and prevent the occurrence of TURS.

BACKGROUND:The utilization of miniscrews for assisting in molar distalization with clear aligners is a commonly adopted clinical approach.However,treatment outcomes may be influenced by the implantation position of miniscrew and the hooks in various tooth location.OBJECTIVE:To analyze the biomechanical effects of hooks at different tooth positions and the assistance of buccal and palatal miniscrews in distalizing molars with clear aligners by using the finite element method.METHODS:By integrating volunteer cone beam CT and Itero intraoral scan data,high-precision finite element models were constructed to simulate the combined use of miniscrews and hooks to assist in the distalization of the maxillary first and second molars with clear aligners,aiming for a designed distalization magnitude of 0.2 mm.Four conditions were established based on the placement of buccal or palatal miniscrews,as well as the located of hooks at the canine or first premolar.The buccal anchorage screw was used in combination with hooks on the buccal side of the canine;the buccal anchorage screw was used in combination with hooks on the buccal side of the first premolar;the palatal anchorage screw was used in combination with hooks on the lingual side of the canine,and the palatal anchorage screw was used in combination with hooks on the lingual side of the first premolar.Analysis using ANSYS software was conducted to evaluate the three-dimensional displacement trends of maxillary teeth and the maximum equivalent stress on the periodontal ligament under each condition.RESULTS AND CONCLUSION:(1)Regardless of whether hooks were placed on canines or first premolars,palatal miniscrews had been shown to enhance the distal movement of maxillary molars and reduce the mesial movement of premolars as well as the labial tipping tendency of anterior teeth,compared to buccal miniscrews.The maximum equivalent stress in the periodontal ligament of molars was increased,while that of anterior teeth was decreased.(2)Regardless of whether the miniscrews were located on the buccal or palatal side,compared with hooks at the first premolar,when hooks were done at the canine,the labial inclination trend of the anterior teeth was reduced,the distal movement of the molars was reduced,the mesial movement of the premolars was increased,and the maximum equivalent stress of the molar and the periodontal membrane of the anterior teeth was reduced.(3)Regardless of whether miniscrews were located on the buccal or palatal side,and the hooks were located on the canine or the first premolar,the molar could not achieve overall movement.(4)The results show that clear aligner combined with palatal miniscrews and hooks at the first premolar are more conducive to improving the efficiency of maxillary molar distalization,but attention should be paid to protecting the anterior tooth miniscrews and molar torque control;clear aligner combined with palatal miniscrews and hooks at the canine is more conducive to reducing the labial tipping tendency of anterior teeth,but the efficiency of molar distalization will be relatively reduced.

Objective To explore the clinical significance of pulse pressure variability(PPV)in early prevention and diagnosis of prostate resection syndrome by observing the changes in PPV during transurethral resection of the prostate.Methods Eighty patients undergoing transurethral resection of the prostate(TURP)under general anesthesia from March to April 2023 were randomly divided into a control group and an observation group,with 40 patients in each group.The control group underwent routine monitoring of invasive blood pressure,while the observation group continued to monitor PPV in addition to invasive blood pressure monitoring.Observe and record the hemodynamic parameters,electrolyte Na+,K+,CL-,Changes in hemoglobin(Hb)and hematocrit(Hct),recording surgical time,intraoperative lavage fluid dosage,and occurrence of dilutive hyponatremia(TURS).Results One patient in the observation group experienced two unexplained drops in blood pressure and heart rate during surgery,and was diagnosed with TURS based on blood gas analysis.Among them,the observation group showed a decreasing trend in PPV with the prolongation of surgery time.PPV gradually decreased at 45～60 minutes after surgery,and at 90 minutes after surgery,PPV decreased significantly compared to preoperative levels.Among them,6 patients had a 50%decrease in PPV compared to preoperative levels.For patients with significantly reduced PPV,immediate treatment was given 10～20 mg of furosemide and 10 mg of dexamethasone.By the end of surgery,PPV had basically recovered to preoperative levels.Both groups of patients showed varying degrees of decrease in Na+,K+,Hct,and Hb levels.Conclusions PPV can reflect the volume status of patients.When PPV decreases by more than 50%compared to preoperative levels and there are unexplained hemodynamic changes and abnormal clinical manifestations during surgery,it is necessary to be vigilant and handle them promptly to reduce and prevent the occurrence of TURS.

BACKGROUND:Stem cell transplantation is a novel therapy for myocardial infarction,but the extremely hostile microenvironment in the infarct area results in low survival rate of stem cells and little long-term effect.Exercise preconditioning is a way to induce endogenous protective effects through exercise,which can be used as a new strategy for prevention and treatment of cardiac rehabilitation. OBJECTIVE:To evaluate whether exercise preconditioning potentiates the cardioprotective effects of adipose-derived stem cell transplantation following myocardial infarction in rats and to explore the mechanism of angiogenesis. METHODS:Six-week-old male SD rats were randomly divided into control group,modeling group,stem cell group,and stem cell plus exercise group.Acute myocardial infarction model was made by coronary artery occlusion,and sham operation was performed in control group.The stem cell plus exercise group underwent aerobic exercise for 8 weeks before modeling,and adipose-derived stem cell transplantation was performed 30 minutes after modeling.The stem cell group performed only adipose-derived stem cell transplantation.One and seven days after stem cell transplantation,the expression levels of myocardial total Akt(t-Akt),phosphorylated Akt(p-Akt),vascular endothelial growth factor(VEGF),total endothelial nitric oxide synthase(t-eNOS),and phosphorylated endothelial nitric oxide synthase(p-eNOS)protein were measured by western blotting,and the ratios of p-Akt/t-Akt and p-eNOS/t-eNOS were calculated.At 4 weeks after stem cell transplantation,the heart structure and function as well as myocardial blood flow were detected by color Doppler ultrasound diagnostic system.Myocardial infarction area was measured by TTC staining.Myocardial interstitial collagen deposition was examined by Masson staining.Myocardial capillary density was detected by immunofluorescence staining,and myocardial apoptosis was measured by TUNEL staining. RESULTS AND CONCLUSION:(1)Four weeks after stem cell transplantation:Compared with control group,left ventricular shortening fraction,left ventricular ejection fraction,myocardial capillary density,and myocardial blood flow decreased(P<0.05),myocardial infarction area,collagen volume fraction,and apoptosis increased(P<0.05)in the modeling group.Compared with the modeling group,the above indexes(except for left ventricular fractional shortening and left ventricular ejection fraction)in the stem cell group improved(P<0.05).Compared with the stem cell group,the above parameters were further improved in the stem cell plus exercise group(P<0.05).(2)One day after stem cell transplantation:Compared with the control group,the protein expression of t-Akt,p-Akt,VEGF,t-eNOS,p-eNOS and the ratio of p-Akt/t-Akt and p-eNOS/t-eNOS had no significant changes in the modeling group(P>0.05).Compared with the modeling group,there were no significant changes in the above indexes in the stem cell group(P>0.05),and p-Akt protein expression and the ratio of p-Akt/t-Akt were up-regulated in the stem cell plus exercise group(P<0.05).(3)Seven days after stem cell transplantation:Compared with the control group,the protein expression of p-Akt,VEGF,p-eNOS and the ratio of p-Akt/t-Akt and p-eNOS/t-eNOS were decreased in the modeling group(P<0.05).Compared with the modeling group,there were no significant changes in all parameters in the stem cell group(P>0.05),and the protein expression of p-Akt,VEGF p-eNOS and the ratio of p-Akt/t-Akt and p-eNOS/t-eNOS were increased in the stem cell plus exercise group(P<0.05).These findings confirm that exercise preconditioning can potentiate the therapeutic effect of adipose-derived stem cells on cardiac remodeling in rats with myocardial infarction,and its mechanism is associated with the promotion of myocardial angiogenesis and blood perfusion.

Mycophenolic acid (MPA), the active moiety of both mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS), serves as a primary immunosuppressant for maintaining solid organ transplants. Therapeutic drug monitoring (TDM) enhances treatment outcomes through tailored approaches. This study aimed to develop an evidence-based guideline for MPA TDM, facilitating its rational application in clinical settings. The guideline plan was drawn from the Institute of Medicine and World Health Organization (WHO) guidelines. Using the Delphi method, clinical questions and outcome indicators were generated. Systematic reviews, Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence quality evaluations, expert opinions, and patient values guided evidence-based suggestions for the guideline. External reviews further refined the recommendations. The guideline for the TDM of MPA (IPGRP-2020CN099) consists of four sections and 16 recommendations encompassing target populations, monitoring strategies, dosage regimens, and influencing factors. High-risk populations, timing of TDM, area under the curve (AUC) versus trough concentration (C₀), target concentration ranges, monitoring frequency, and analytical methods are addressed. Formulation-specific recommendations, initial dosage regimens, populations with unique considerations, pharmacokinetic-informed dosing, body weight factors, pharmacogenetics, and drug‍-‍drug interactions are covered. The evidence-based guideline offers a comprehensive recommendation for solid organ transplant recipients undergoing MPA therapy, promoting standardization of MPA TDM, and enhancing treatment efficacy and safety.
Mycophenolic Acid/administration & dosage* ; Drug Monitoring/methods* ; Humans ; Organ Transplantation ; Immunosuppressive Agents/administration & dosage* ; Delphi Technique

ObjectiveTo investigate the efficacy of ovarian tissue cryopreservation and autologous transplantation in preserving fertility and ovarian endocrine function in patients with cervical cancer. MethodsA 26-year-old patient with stage ⅡA1 cervical cancer underwent ovarian tissue harvesting and cryopreservation during cancer surgery. Following complete remission of the cancer， autologous ovarian tissue transplantation was performed. Follow-up monitoring included assessment of menopausal symptoms， hormone levels， and follicular development. ResultsSix months after transplantation， follicle-stimulating hormone levels decreased to 6.60 U/L， and estradiol levels increased from ＜10.00 ng/L to 89.00 ng/L. At 10 months after transplantation， ultrasound monitoring confirmed follicular development and physiological ovulation in the transplanted ovarian tissue. By 15 months after transplantation， follicle-stimulating hormone levels remained stable at 7.24 U/L， and estradiol levels further increased to 368.00 ng/L. Over 2 years after transplantation， the patient successfully gave birth to a healthy baby through assisted reproductive technology. ConclusionThe restoration of endocrine and ovulation functions in the transplanted cryopreserved ovarian tissue， followed by successful pregnancy， demonstrates the clinical success of ovarian tissue transplantation.

BACKGROUND:Exercise is an effective strategy to prevent and treat various cardiovascular diseases and protect the heart from ischemia-reperfusion injury.Its mechanism of action needs to be studied in depth. OBJECTIVE:To observe the effect of aerobic exercise preconditioning on myocardial ischemia-reperfusion injury and to explore the effect of endothelial nitric oxide synthase(eNOS)activation(including coupling and phosphorylation). METHODS:Eighty adult Wistar rats were randomly divided into sedentary(n=40)and exercise(n=40)groups.The rats in the exercise group were subjected to aerobic exercise for 8 weeks while those in the sedentary group were quietly fed and caged.After 8 weeks of intervention,three experiments were performed.(1)Experiment 1:After the last training,cardiac function,cardiac nitric oxide metabolite content and cardiac eNOS,phosphorylated eNOS-S1177,eNOS dimer and eNOS monomer protein expression levels were detected.(2)Experiment 2:Rats were divided into sedentary control group,exercise control group,sedentary+eNOS inhibitor group,exercise+eNOS inhibitor group,all of which were subjected to an in vitro myocardial ischemia-reperfusion injury experiment.eNOS inhibitor was continuously infused into the sedentary+eNOS inhibitor group and exercise+eNOS inhibitor group 10 minutes before reperfusion,and cardiac function and myocardial infarction area were detected 3 hours after reperfusion.(3)Experiment 3:Rats were divided into sedentary control group,exercise control group,sedentary+eNOS coupler group and exercise+eNOS coupler group,all of which were subjected to an in vitro myocardial ischemia-reperfusion injury experiment.The rats in the sedentary+eNOS coupler group and exercise+eNOS coupler group were treated with eNOS coupler.Myocardial infarct area,cardiac nitric oxide metabolite content,cardiac protein expression of eNOS,phosphorylated eNOS-S1177,eNOS dimer,eNOS monomer and 3-nitrotyrosine were detected 3 hours after reperfusion.The phosphorylated eNOS-S1177/eNOS ratio reflected the phosphorylated/dephosphorylated level of eNOS and eNOS dimer/monomer ratio reflected eNOS coupling/uncoupling level. RESULTS AND CONCLUSION:Experiment 1:Compared with the sedentary group,the exercise group had increased cardiac output and left ventricular ejection fraction(P<0.05),increased nitrite and S-nitrosothiol contents(P<0.05),upregulated phosphorylated eNOS-S1177,eNOS protein expression and phosphorylated eNOS-S1177/eNOS ratio(P<0.05),eNOS dimer protein expression and eNOS dimer/monomer ratios were elevated(P<0.05).Experiment 2:Compared with the sedentary control group,left ventricular development pressure increased(P<0.05)and myocardial infarct area decreased(P<0.05)in the exercise control group.Compared with the exercise control group,left ventricular development pressure decreased(P<0.05)and myocardial infarct area increased(P<0.05)in the exercise+eNOS inhibitor group.Experiment 3:Compared with the sedentary control group,the exercise control group had increased left ventricular developmental pressure(P<0.05),decreased myocardial infarct area(P<0.05),decreased phosphorylated eNOS-S1177/eNOS ratio(P<0.05),decreased eNOS dimer/monomer ratio(P<0.05),increased S-nitrosothiol content(P<0.05),and decreased 3-nitrotyrosine protein expression(P<0.05).Compared with the exercise control group,the exercise+eNOS coupler group had decreased left ventricular developmental pressure(P<0.05),increased myocardial infarct area(P<0.05),increased phosphorylated eNOS-S1177/eNOS ratio(P<0.05),increased eNOS dimer/monomer ratio(P<0.05),and elevated 3-nitro tyrosine protein expression(P<0.05).To conclude,aerobic exercise preconditioning could induce cardioprotection,which is related to uncoupling and dephosphorylation of eNOS during cardiac ischemia-reperfusion,thereby inhibiting the excessive production of nitric oxide and reducing nitro-oxidative stress.

BACKGROUND:Stem cell therapy is an alternative treatment strategy for restoring damaged myocardial tissue after acute myocardial infarction.Exercise preconditioning can induce endogenous cardioprotective effects in the body.However,the efficacy and mechanism of the combined application are still unclear. OBJECTIVE:To explore the effect and possible mechanism of exercise preconditioning combined with bone marrow mesenchymal stem cells on the therapeutic effect in rats with acute myocardial infarction. METHODS:Seventy male SD rats were randomly divided into sham operation group,model group,stem cell therapy group,exercise preconditioning group,and combined intervention group.Rats in the exercise preconditioning group and combined intervention group underwent 8-week aerobic exercise on the treadmill before modeling.The animal model of acute myocardial infarction was made by ligating the anterior descending coronary artery.The stem cell therapy group and the combined intervention group were injected with bone marrow mesenchymal stem cells(1×109 L-1,1 mL)through the tail vein the next day after modeling.After 4 weeks of treatment,the exercise performance was evaluated by a graded treadmill exercise test.The cardiac structure and function were detected by echocardiography.The left ventricle was isolated.2,3,5-Triphenyltetrazolium chloride staining was used to evaluate myocardial infarct size.Masson staining was used to obtain collagen volume fraction.CD31 immunohistochemical staining was used to detect myocardial capillary density.TUNEL staining was used to detect myocardial cell apoptosis.Immunoblotting was used to detect protein expression levels of stromal cell-derived factor 1,CXC chemokine receptor protein 4,tumor necrosis factor-α,interleukin-10,and vascular endothelial growth factor. RESULTS AND CONCLUSION:(1)Intervention efficacy:Compared with the sham operation group,exercise performance,left ventricular ejection fraction,left ventricular fractional shortening,and CD31 positive cell rate decreased(P<0.05);myocardial infarct size,collagen volume fraction,and myocardial apoptotic rate increased(P<0.05)in the model group.Compared with the model group,exercise performance was not statistically significant(P>0.05)in the stem cell therapy group,and the exercise performance improved(P<0.05)in the exercise preconditioning and combined intervention groups;left ventricular ejection fraction,left ventricular fractional shortening,and CD31 positive cell rate increased(P<0.05),and the myocardial infarct size,collagen volume fraction,and cardiomyocyte apoptosis rate decreased(P<0.05)in the stem cell therapy,exercise preconditioning,and combined intervention groups.Compared with the stem cell therapy group,exercise performance,left ventricular ejection fraction,left ventricular shortening fraction,and CD31 positive cell rate increased(P<0.05),myocardial infarct size,collagen volume fraction,and myocardial cell apoptosis rate decreased(P<0.05)in the combined intervention group.(2)Protein expression:Compared with the sham operation group,the expression of tumor necrosis factor-α increased(P<0.05),while interleukin-10 and vascular endothelial growth factor expression decreased(P<0.05)in the model group.Compared with the model group,the expression of CXC chemokine receptor protein 4 increased(P<0.05)in the stem cell therapy group and combined intervention group,and the expression of tumor necrosis factor-α decreased(P<0.05)while interleukin-10 and vascular endothelial growth factor increased(P<0.05)in the stem cell therapy group,exercise preconditioning group,and combined intervention group.Compared with the stem cell therapy group,the expression of tumor necrosis factor-α decreased(P<0.05),while CXC chemokine receptor protein 4,interleukin-10,and vascular endothelial growth factor increased(P<0.05)in the combined intervention group.To conclude,exercise preconditioning can enhance the therapeutic effect of bone marrow mesenchymal stem cells in rats with acute myocardial infarction,which can inhibit cardiac remodeling,improve cardiac function,and delay the progress of heart failure.Its mechanism is related to the promotion of stem cell homing,inhibition of inflammatory response,and promotion of angiogenesis.