Hazard ratio (HR) is usually regarded as the effect size in survival studies. Meanwhile, it is supposed to be perfect for pooling results in the meta-analysis of survival data. However, it does not function usually due to absence of original data for pooling HR. As a compromise method, entering data from reading Kaplan-Meier curves and follow-up times into the calculation spreadsheet can also be used to obtain related survival data. But related study on the subject is scarce, and opinions are inconsistent. Accordingly, we conduct this study to further illustrate the procedure in details.
ObjectiveTo investigate the effect of simvastatin and mechanical pretreatment on intimal hyperplasia of venous graft and its mechanism.MethodsTwelve New Zealand rabbits were selected and randomly divided into 4 groups: a blank control group, a simvastatin topical treatment group, a mechanical precondition group and a combined group (n=3 in each group). Ultrasound was used to evaluate the changes of graft wall and blood flow velocity in the graft, and pathological section was used to evaluate the intimal hyperplasia. Human umbilical cord endodermal cells were cultured in vitro. A simvastatin group and a solvent control group were set to detect YAP phosphorylation, downstream target gene expression and cell proliferation.ResultsVascular ultrasound showed that except the simvastatin topical treatment group, the flow velocity in vein grafts in the other three groups significantly increased 21 days after surgery compared with 7 days after surgery (P<0.01). Pathological sections showed that the thickness of new intima in the simvastatin topical treatment group, mechanical precondition group, combined group and blank control group were 45.56±4.11 μm, 201.28±16.71 μm, 143.57±7.82 μm, 249.45±13.33 μm, respectively, and there were statistical differences compared with the blank control group (P<0.05). In vitro results showed that compared with the solvent control group, cell death was observed in high concentration simvastatin (5 mmol/L) group, cell proliferation was inhibited in low concentration simvastatin (2.5 mmol/L) group (P<0.05), the expression of YAP protein in the simvastatin group was unchanged, but the expression of phosphorylated YAP protein significantly increased (P<0.05), and the expression of downstream target gene ccn1 was down-regulated (P<0.001).ConclusionIntravascular local application of simvastatin and mechanical preconditioning alone or in combination can inhibit intimal hyperplasia of venous graft. High concentration of simvastatin has cytotoxicity, while low concentration of simvastatin has inhibitory effect on cell proliferation. Simvastatin can inhibit the formation of new intima by inhibiting the entry of YAP into the nucleus and reducing the transcription of cell proliferation-related target gene ccn1.
Objective To explore the effect of " closed-loop rehabilitation”-based digital mirror therapy (MT) on the recovery of upper limb function after stroke. Methods Between December 2017 and April 2018, 90 stroke patients were recruited and randomly assigned to digital MT group (MG) or conventional group (CG), with 45 in each group. Patients in MG received digital MT for 60 minutes and subsequent hand function rehabilitation for 30 minutes, which was a " closed-loop rehabilitation”; moreover, patients in CG received therapeutic exercises, occupational therapy, and hand function rehabilitation for 30 minutes separately (totally 90 minutes). Both interventions were daily provided, 5 days per week and lasting for 4 weeks. Clinical assessments were provided before and after the interventions, including the Fugl-Meyer Assessment Upper Limb (FAM_UL) for motor function evaluation, the Modified Barthel Index (MBI) for the activities of daily life (ADL) evaluation, and the Modified Ashworth Scale (MAS) for the spasticity of wrist extensor/flexor. Results Five patients did not complete the study (3 in MG and 2 in CG), so there were totally 85 subjects analysed in the end. After 4-week interventions, significant improvements of FMA_UL scores (Pre: MG, 25.86±17.41; CG, 21.71±15.60. Post: MG, 33.43±17.08; CG, 26.48±16.47) and MBI scores (Pre: MG, 66.62±21.73; CG, 59.14±21.58. Post: MG, 84.62±15.06; CG, 71.10±19.95) were found in both groups; moreover, higher scores of FMA_UL and MBI were investigated in MG comparing with CG after interventions. However, there were no significantly differences in MAS. Conclusions The " closed-loop rehabilitation”-based digital MT can improve the motor function of upper limb and the ability of ADL in patients with stroke. Moreover, it is more effective than conventional treatments.