Evaluation of left ventricular myocardial systolic function in patients with aortic stenosis by layer-specific strain / 中国医师杂志

Objective:To explore the value of layer-specific strain technique in evaluating the changes of left ventricular myocardial systolic function in patients with aortic stenosis(AS).Methods:From January 2019 to March 2022, 90 AS patients with left ventricular ejection fraction (LVEF) ≥ 50% in Hunan Provincial People's Hospital were selected, including 30 mild AS patients, 30 moderate AS patients, and 30 severe AS patients. In addition, 30 health examinees in the same period were selected as the control group. The normal echocardiographic parameters of the control group and the AS groups with different degrees were compared. The global systolic peak longitudinal strain (GLS) and global circumferential strain (GCS) of the left ventricular three-layer myocardium were measured by the layer-specific strain technique, and the correlation between the strain parameters and the peak systolic velocity (Vmax) of the aortic valve was analyzed.Results:The levels of interventricular septal depth (IVSD), left ventricular posterior wall depth (LVPWD), mean pressure gradient (MPG), and Vmax in mild, moderate and severe AS group were higher than those in the control group (all P<0.05); the GLS of each layer of left ventricle in mild, moderate and severe AS group was lower than those in control group (all P<0.05); the GCS of each layer of left ventricle in moderate and severe AS group was lower than those in control group (all P<0.05). The GLS of left ventricular endocardium in moderate AS group was lower than those in mild AS group (all P<0.05); the GLS and GCS of left ventricular layers in severe AS group were lower than those in mild and moderate AS group (all P<0.05). In AS group, GLS and GCS in endocardium, middle layer and epicardium were negatively correlated with Vmax ( r=-0.716, -0.660, -0.669, P<0.001; r=-0.669, -0.686, -0.598, P<0.001). Conclusions:The layer-specific strain can reflect the changes of left ventricular myocardial function in patients with AS, and has certain application value.

Design Optimization and Manufacturing of Bio-fixed tibial implants using 3D printing technology.

To obtain high performance (matching, mechanical properties, and biocompatibility) of personalized biomechanical fixation-type tibial implants, three-dimensional reconstruction was performed using a combination of reverse and positive methods. The implant design was optimized using a topological optimization method, the shape-optimized B-unit structure was filled, and the performance was evaluated for implants prepared by direct forming technology of Selective Laser Melting (3D Printing). The results show obviously reduced weight of the tibial implant, increased stress and displacement, yet with a more uniform distribution. The mechanical properties of the tibial implant were lower than those of the B-units, the weight was lighter, and the stress distribution was more uniform. The surface of the tibial implants prepared by SLM appeared clean and bright, the metal texture was good, the structure between the porous struts was clear, the surface had low powder adhesion, the lap joint was good, and no obvious warping deformation or forming defects were observed. The results of this study provide a foundation for the direct application of high performance personalized biofixation implants.

Effect of different fluid resuscitation strategies on respiratory mechanics and oxygenation in patients with septic shock / 重庆医学

Objective To observe the effect of different fluid resuscitation strategies on respiratory mechanics and oxygena-tion in the patients with septic shock .Methods The treatment data in 125 patients with septic shock in ICU of this hospital were retrospectively investigated and analyzed .The patients were divided into the restriction fluid resuscitation group (n=58) and open fluid resuscitation (n=67) according to fluid resuscitation results .The changes of respiratory mechanics (static lung compliance ,in-spiratory resistance) and oxygenation before and after resuscitation were compared between the two groups .Meanwhile the hemo-dynamics and vasoactive drugs application were recorded in the two groups .Results The hemodynamic indicators had no statistical difference between the two groups .The use amounts and use time of vasoactive drugs in the open fluid resuscitation group were less than those in the restriction fluid resuscitation group (P<0 .01);the airway resistance in the two groups had no obvious change be-tween before and after resuscitation ,the lung compliance and oxygenation in the restriction fluid resuscitation group were superior to those in the open fluid resuscitation group (P<0 .01) .With the fluid resuscitation amount increase ,the lung compliance in the re-striction fluid resuscitation group and open fluid resuscitation group were progressively poorer ,which was especially obvious in the open fluid resuscitation group(P<0 .01);the amount of fluid resuscitation was negatively correlated with the lung compliance and oxygenation (R= -0 .783、-0 .860 ,P<0 .01) .Conclusion In treating septic shock ,although the open resuscitation strategy has smaller dose and use time of vasoactive drugs ,but the lung compliance and oxygenation are affected ,while the restriction fluid re-suscitation strategy is in contrast .

Clinical observation of inhalation combined salmeterol plus fluticasone propionate aerosol in treatment of asthma in preschool children / 国际儿科学杂志

Objective To study the effect of inhalation combined salmeterol plus fluticasone propionate in treatment of asthma in children between 4 ～ 5 years old.Methods Seventy-four children (age range,4 ～ 5 years) were enrolled for our study,they were randomly divided into 2 groups (one group inhaled combined salmeterol plus fluticasone,37 children;the other group inhaled fluticasone,37 children).Comparative studies of clinical efficacy,quantified symptom score,and regular follow-up observations were conducted at the interval of one week,one month,three months.Results In the first week and first month during the treatment,there were no difference between salmeterol plus fluticasone group and fluticasone group (P ＞ 0.05).In the third month during the treatment,the daytime ratings(0.16 ± 0.09 vs 0.32 ± 0.11,P ＜ 0.05) and night ratings(0.04 ± 0.01 vs 0.14 ±0.00,P ＜0.05) of salmeterol plus fluticasone group were significantly better than those of fluticasone group.After three months,more children in salmeterol plus fluticasone group were responsive to the decreased dose of the drug than those of fluticasone group (x2 =4.57,P ＜ 0.05).Conclusion In the follow-up of exacerbatious,treatment with combined salmeterol and fluticasone propionate was as efficient as that of fluticasone in alleviating symptoms.During remission of asthma,combined salmeterol and fluticasone propionate was probably better than fluticasone for control of symptoms.

The rs11833579 and rs12425791 polymorphisms and risk of ischemic stroke in an Asian population: a meta-analysis.

BACKGROUND: In 2009, a GWAS has confirmed that rs11833579 and rs12425791 near the NINJ2 gene could increase the stroke and ischemic stroke (IS) risk. Recently, several studies have been implemented to assess the relationship between the two SNPs and ischemic stroke risk in Asian. However, the results were poorly consistent. To study the association between the both polymorphisms and the risk of ischemic stroke, we performed a meta-analysis. METHODS: We used odds ratios (ORs) with 95% confidence intervals (CIs) to evaluate the strength of association. The heterogeneity was checked by Q test and the inconsistency index (I(2)). Begg's test and Egger's test were used to assess the possible publication bias. RESULTS: Our study included 6 articles, contained 9 independent case-control studies, involved a total of 9,142 cases and 10,652 controls about rs11833579, 10,165 cases and 11,592 controls about rs12425791. There was a significant association between rs12425791 and IS risk with dominant genetic model (OR=1.087, 95%CI=1.021-1.158, I(2)=34.6%, P=0.152), but not with recessive genetic model and allele A vs. allele G. For rs11833579, we failed to verify it relate with IS risk under allele A vs. allele G, dominant and recessive genetic model. CONCLUSIONS: This meta-analysis suggest that rs12425791 is relative to ischemic stroke risk under dominant model in Asian population, but not for rs11833579.

Clinical Application of Tidal Flow-volume Measurement and Its Impact Factors / 医学研究杂志

Objective To study the clinical application and its impact factors of tidal flow - volume measurement in infants with bronchiolitis and pneumonia. Methods Thirty infants with bronchiolitis and thirty infants with pneumonia were studied. Tidal breathing flow- volume loops were obtained after the patients were sedated. The tidal volume per kilogram(VT/kg) ,the fraction of tidal volume ex-heled at peak tidal expiratory flow (PTEF) to total tidal volume (VPTEF/VE), and the fraction of exhaled time at PTEF to total expirato-ry time (TPTEF/TE) were measured. Results VT/kg was not significant different between the bronehiolitis group and the pneumonia group. VPTEF/VE and TPTEF/TE were lower in the bronehiolitis group than those in the pneumonia group. Conclusion The measure-ment of tidal breathing flow - volume loops is a good technology, which would be helpful to evaluate airway obstruction in wheezing in-fants. The impact factors should be controlled during the measurement. Otherwise, the results would be affected.