[The relationship between left ventricular artery coupling and left ventricular work and their predictive value on prognosis in septic shock]

Objective: To explore the relationship between left ventricular artery coupling and left ventricular work in patients with septic shock, and further clarified their predictive value for the prognosis of septic shock. Methods: In total, 56 patients with septic shock admitted in the Department of Critical Care Medicine of Peking Union Medical College Hospital were retrospectively enrolled between January 2016 and July 2021. The hemodynamic indexes and clinical data monitored by pulse indicator continuous cardiac output (PICCO) at different time points were collected. To reveal alterations of arterial elastance index (EaI), end-systolic elastance index (EesI), EaI/EesI, stroke work (SW), total cardiac function (PVA), and left ventricular ejection efficiency (LVEf) in patients with septic shock at different time points. The patients were divided into the death group (n=20) and survival group (n=36) according to the outcome of the ICU. The relationship between left ventricular work and left ventricular arterial coupling and its prognostic value were statistically analyzed. Results: A total of 56 patients were enrolled, 32 males and 24 females, aged (61±15) years. There was a significantly difference in EaI/EesI and LVEf between survivors and non-survivors with septic shock at 6 h (P<0.05). Further analysis showed that the correlation between EaI/EesI and LVEf was most evident at 6 h after intervention. EaI/EesI was negatively correlated with SW (r_s=-0.500, P<0.001), and highly negative with LVEf (r_s=-0.959, P<0.001). Both univariate logistic regression and multivariate regression analysis showed that EaI/EesI (adjusted OR=42.783, 95%CI: 2.725-671.819, P=0.008) and LVEf (adjusted OR=2.293, 95%CI:1.222-4.301, P=0.010) were risk factors for ICU prognosis of patients with septic shock. The receiver operating characteristic (ROC) curve analysis showed that EaI/EesI [area under the curve (AUC)=0.742±0.083, P=0.004; cut-off value 6.10, sensitivity 88.9%, specificity 65.0%] and LVEf (AUC=0.733±0.084, P=0.006; cut-off value 0.24, sensitivity 88.8%, specificity 60.0%) were both effective indicators for predicting the prognosis of patients with septic shock in the ICU. Moreover, EaI/EesI had a better prognosis value than LVEf (ΔAUC=0.120, Z=6.528, P=0.036). Conclusion: It's indicated that EaI/EesI was significantly correlated with SW and LVEf after 6 h of septic shock intervention; EaI/EesI and LVEf are risk factors and effective predictors of ICU prognosis in patients with septic shock. The predictive efficacy of EaI/EesI is greater than LVEF.

[Risk factors and prognosis in critical patients with sepsis-related cardiomyopathy]

Objective: To explore the risk factors and prognosis of sepsis-related cardiomyopathy. Methods: Patients with sepsis and septic shock admitted to the Critical Care Medicine Department at Peking Union Medical College Hospital from October 2017 to February 2021 were enrolled. Echocardiographic parameters including left ventricular ejection fraction (LVEF), tricuspid annular plane systolic excursion (TAPSE) and cardiac index (CI) were obtained within 24 h after admission. Hemodynamic parameters including heart rate, mean arterial pressure and central venous pressure were also collected. The risk factors of 45-day mortality were analyzed using Cox regression analysis. Kaplan-Meier survival analysis was performed to compare 45-day mortality among patients with normal left ventricle (LV) systolic function group, sepsis-related takotsubo cardiomyopathy (ST) and septic cardiomyopathy (SC) group as well as between patients with normal right ventricular (RV) function and patients with RV dysfunction. Results: According to LV systolic function, patients were categorized into three groups: normal group [174 (66.9%)], SC group [66 (25.4%)] and ST group [66 (25.4%)]. In comparison with those in normal group, patients in SC group and ST group had higher acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score and sequential organ failure assessment (SOFA) score (P<0.05). No difference was found between SC group and ST group regarding APACHE Ⅱ score and SOFA score(P>0.05). ST group had lower LVEF [33(28, 41)% vs. 45(38, 48)%, P<0.05], CI [2.29 (1.99, 2.53)L·min^-1·m^-2 vs. 3.04(2.61, 3.61) L·min^-1·m^-2, P<0.05] higher TAPSE [18.6(16.0, 21.2)mm vs. 15.1(12.5, 19.0)mm, P<0.05] than SC group. A Cox regression survival analysis showed that right ventricular dysfunction (RVD) was an independent predictor of 45-day mortality (HR=1.992, 95%CI 1.088-3.647, P=0.025). A Kaplan-Meier analysis revealed no significant difference regarding 45-day mortality among ST group [25.0%(5/20)], SC group [30.3%(20/66)] and normal group 18.4%(32/174)(P=0.158). RVD patients [38.0%(30/79)] had significantly higher 45-day mortality than patients with normal RV function [14.9%(27/181),P<0.001]. Conclusions: In comparison with SC patients, ST patients tend to have worse LV systolic function, lower cardiac output and better RV function. However, neither ST nor SC is associated with 45-day mortality. RVD is a risk predictor of 45-day mortality, which should be monitored in septic patients.

[An analysis on incidence of HIV-1 epidemics among men who have sex with men in Sichuan Province during 2011-2015]

The assay was used in HIV/AIDS surveillance sentinel sites to identify recent HIV-1 infection, to estimate HIV-1 incidence and understand the epidemic trends among men who have sex with men during 2011-2015. During 2011-2015, the HIV-1 incidence of men who have sex with men was 5.16%(95%CI: 4.65%-5.66%) in Sichuan Province. According to<Pilot study on classification criteria of AIDS epidemic in China>, a total of 9 cities had been divided into two type of regions: the first type(the proportion of live HIV/AIDS accounts for more than 0.1% of the permanent population, and the number of live HIV/AIDS has reached 500 cases and above) and the second type(the proportion of live HIV/AIDS accounts for 0.03% to 0.100% of the permanent population, and the number of live HIV/AIDS has reached 100-500 cases). During 2011-2015, the HIV-1 incidence of the second type was 4.24% (95%CI: 3.72%-4.76%). The HIV-1 incidence of men who have sex with men was at a high level. The spread of HIV-1 to the second region was possible.

[Incidence rates of HIV-1 epidemics among 4 high risk groups in Sichuan province during 2011-2015]

Objective: Data from the HIV/AIDS surveillance sentinel sites was used to identify the recent HIV-1 infections and to estimate the HIV-1 incidence and epidemic trends among intravenous drug users (IDU), MSM, female sex workers and men attending the sexually transmitted disease clinics in Sichuan province. Methods: Specimens collected from IDUs, MSM, female sex workers and men attending the sexually transmitted disease clinics sentinel sites were confirmed as HIV-1 positive and tested with BED-CEIA. Annual HIV-1 prevalence and incidence rates were calculated and the incidence was adjusted by McNermar method. Results: A total number of 194 223 serum specimens were collected and HIV antibody tested, with 5 297 HIV-1 positive. 4 640 of the positives underwent BED-CEIA, with 749 identified as recent infections. During 2011-2015, HIV-1 incidence rates of the four types of population appeared as 5.16% (95%CI: 4.65-5.66), 0.22% (95%CI:0.16-0.28), 0.57%(95%CI: 0.45-0.69), 7.53% (95%CI: 6.06-9.01) and 0.44% (95%CI: 0.36-0.53) respectively. Significant differences were seen in the HIV-1 incidence rates. Conclusions: The HIV-1 incidence rates of IDUs from other sentinel sites in Sichuan province, female sex workers and men attending the sexually transmitted disease clinics appeared low, showing that the AIDS prevention and control activities worked effectively. However, the HIV-1 incidence of MSM was still at high level and even rising, suggesting that HIV-1 transmission between MSM and IDUs was possible.

The use of transcallosal-interforniceal approach for microsurgical removal of the third ventricle tumors

AIM

The third ventricle is located deep in the brain and is adjacent to important neurovascular structures. This makes tumor resection in this region difficult and causes more postoperative complications than surgeries in other regions of the brain. The objective of this study was to investigate the feasibility and clinical effects of transcallosal-interforniceal approach for microsurgical removal of the third ventricle tumors.

METHODS

After preoperative evaluation, 23 patients with the third ventricle tumors were microsurgically operated using the transcallosal-interforniceal approach.

RESULTS

Of these 23 patients, 12 (52.2%) underwent total excision, 9 (39.1%) had subtotal resection, and the remaining 2 (8.7%) underwent partial excision. After surgery, the following complications were observed: diabetes insipidus (11 patients), hemorrhages of the upper digestive tract (2 patients), central fever (1 patient), and memory impairment (1 patient). No mortality in the perioperative period was reported.

CONCLUSION

The surgical procedure using the transcallosal-interforniceal approach is direct and provides good surgical field exposure and fewer post operational compilations. This approach should be considered as the method of choice for surgical removal of the third ventricle tumors.

Process of aerenchyma formation and reactive oxygen species induced by waterlogging in wheat seminal roots

The development and regulation of aerenchyma in waterlogged conditions were studied in the seminal roots of wheat. Evans blue staining and the first cell death position indicated that the cortical cell death began at the root mid-cortex cells in flooding conditions. Continuous waterlogging treatment caused the spread of cell death from the mid-cortex to the neighboring cells and well-developed aerenchyma was formed after 72 h. Meanwhile, the formation of radial oxygen loss barrier was observed in the exodermis owing to the induction of Casparian bands and lignin deposition. Analysis of aerenchyma along the wheat root revealed that aerenchyma formed at 10 mm from the root tip, significantly increased toward the center of the roots, and decreased toward the basal region of the root. In situ detection of radial oxygen species (ROS) showed that ROS accumulation started in the mid-cortex cells, where cell death began indicating that cell death was probably accompanied by ROS production. Further waterlogging treatments resulted in the accumulation of ROS in the cortical cells, which were the zone for aerenchyma development. Accumulation and distribution of H₂O₂ at the subcellular level were revealed by ultracytochemical localization, which further verified the involvement of ROS in the cortical cell death process (i.e., aerenchyma formation). Furthermore, gene expression analysis indicated that ROS production might be the result of up-regulation of genes encoding for ROS-producing enzymes and the down-regulation of genes encoding for ROS-detoxifying enzymes. These results suggest that aerenchyma development in wheat roots starts in the mid-cortex cells and its formation is regulated by ROS.

Conch shell structure and its effect on mechanical behaviors

The shell of pink conch is a kind of natural well-designed composite with excellent mechanical properties, which provides us information for material design. In this paper the microstructures of pink conch shell are characterized by using SEM and TEM. The microscopic analysis indicates that the pink conch shell is with crossed-lamellar microstructure and the angle between two second-order lamellae is 70-90 degrees. The cracking and fracture morphologies indicate that the crack deflection, bridge and fiber pullout are the main toughening mechanisms. Bamboo lamellae are employed to make the simple bio-mimetic model materials. In the model material the rotated angle between the fibers of each glued lamella varies from 0 degrees to 90 degrees. Three-point-bending is employed to test the properties of models material, such as the elastic modulus, the flexural strength and the fracture strain energy density. It is found that the fracture strain energy density of the specimens with the rotated angle between the fibers of the layers about 60 degrees exhibits the maximum value, which is close to the angle of the two second-order lamellae of the conch shell.

Modes of a laser resonator with a retroreflective mirror

The self-consistent integral equation for the field distribution of the resonant modes in an inclined retroreflective grating resonator is solved in the limit of large Fresnel numbers. The transverse field distribution in the direction perpendicular to the grating grooves can be described in terms of Hermite-Gaussian functions provided that lambda << d << w, where lambda is the wavelength, d is the grating spacing, and w is the beam spot size.