[Etiological diagnostic value of metagenomic next-generation sequencing in peritoneal dialysis-related peritonitis]

Objective: To explore the etiological diagnostic value of metagenomic next-generation sequencing (mNGS) in peritoneal dialysis (PD)-related peritonitis. Methods: The study was a retrospective cohort study. The clinical data of patients with PD-related peritonitis who were treated and underwent microbial cultivation and mNGS test at the same time from June 2020 to July 2021 in the Affiliated Drum Tower Hospital, Medical School of Nanjing University were analyzed. The positive rate, detection time and consistency between mNGS test and traditional microbial culture were compared. Results: A total of 18 patients with age of (50.4±15.4) years old and median dialysis time of 34.0 (12.4, 62.0) months were enrolled in the study, including 11 males and 7 females. Pathogenic microorganisms were isolated in 17 patients by mNGS test, with a positive rate of 17/18, which was higher than 13/18 of microbial culture, but the difference was not statistically significant (P=0.219). Both mNGS test and microbial culture isolated positive pathogenic bacteria in 12 patients, and mNGS test isolated the same types of pathogenic bacteria as microbial cultivation did in 11 patients. In five patients with negative microbial culture, mNGS test also isolated pathogenic microorganisms, including 3 cases of Staphylococcus epidermidis, 1 case of Mycobacterium tuberculosis and 1 case of Ureaplasma urealyticum. In 1 patient, microbial culture isolated pathogenic bacteria (Escherichia coli) whereas mNGS test did not. The detection time of mNGS was 25.0 (24.0, 27.0) h, which was significantly shorter than 89.0 (72.8, 122.0) h of microbial culture (Z=3.726, P<0.001). Conclusions: mNGS test can improve the detection rate of pathogenic microorganisms in PD-related peritonitis and greatly shorten the detection time, and has good consistency with microbial culture. mNGS may provide a new approach for pathogen identification of PD-related peritonitis, especially refractory peritonitis.

[The role of respiratory therapy in respiratory rehabilitation of critically ill patients]

The job description of respiratory therapists can cover emergency room, intensive care unit (ICU), post-ICU ward and specialized wards. Therefore, patient-centered respiratory rehabilitation in critically ill patients includes prevention of admission to ICU, respiratory care during ICU, and respiratory care after ICU. Respiratory therapists evaluate, diagnose and treat patients' respiratory function, forming a closed-loop management scheme of prevention, evaluation, treatment, reassessment, and adjustment.

[Icariin reduces S-nitrosogultathione induced endothelial cell apoptosis through modulating AKT/P53 pathway]

OBJECTIVE

To observe the effects of icariin on S-nitrosogultathione(GSNO) induced endothelial cell apoptosis, and to explore the relative mechanisms.

METHODS

EA.hy926 cell line was provided by Zhejiang University and cells were divided into blank control group, GSNO group (1 mmol/L GSNO), icariin (ICA) intervention group (GSNO+ different concentrations (high, medium and low: 10, 1 and 0.1 μmol/L ICA) and 1 μmol/L LY294002 pretreatment groups (AKT protease pathway inhibitor on top of ICA groups) by cluster random sample method. After 48 hours. EA.hy 926 cell survival was detected by thiazolyl blue tetrazolium bromicle (MTT) method. Lactate dehydrogenase (LDH) activity, malonaldehyde (MDA) content, reactive oxygen species (ROS) level, mitochondrial membrane potential were also measured. The protein expression of protein kinase B(AKT)/phosphorylation protein kinase B(p-AKT), people tumor-suppressor protein (protein 53, P53), cytochrome C (CYC), endothelial nitric oxide synthetase (eNOS)/phosphorylation endothelial nitric oxide synthetase (p-eNOS), procaspase-3/caspase-3 was detected by Western blot.

RESULTS

(1) The cell survival rate was significantly lower in GSNO group than in the blank control group (P< 0.01), which was significantly higher in the high, medium and low concentration ICA groups than in the GSNO group (all P< 0.01). (2) The LDH activity was significantly higher in the GSNO group than in the blank control group ((142.65±5.56) U/L vs. (50.01±3.42) U/L, P< 0.05), which was significantly reduced by high, medium and low concentration ICA ((98.02±3.52), (105.29±6.89) and (117.16±4.27) U/L vs. (142.65±5.56) U/L, all P< 0.05) in a dose-dependent manner. (3) The MDA content was significantly higher in GSNO group than in the blank control group ((11.14±0.37) nmol/mg vs. (5.21±0.18) nmol/mg, P< 0.05), which could be reduced by pretreatment with high, medium and low concentration ICA ((6.60±0.41), (6.83±0.21) and (8.29±0.07) nmol/mg vs. (11.14 ±0.37) nmol/mg, all P< 0.05). (4) The ROS content was significantly higher in GSNO group than in the blank control group ((173.15±11.12)% (relative ratio to the blank control group), P< 0.05), which could be significantly reduced by pretreatment with high, medium and low concentration ICA ((122.56±8.09)%, (134.52±9.09)%, and(149.89±9.16)% (the ratio of the above are compared with the blank control group), P< 0.05). (5) The mitochondrial membrane potential was significantly higher in the GSNO group (0.84 ± 0.04) than in the blank control group (0.12 ±0.12), which could be significantly reduced by pretreatment with high, medium and low concentration ICA ((0.57±0.08), (0.63±0.02), (0.66±0.04) vs. (0.84±0.04), all P<0.05). (6) The expression of AKT/p-AKT was significantly lower in GSNO group than in the blank control group (P< 0.05), which could be significantly upregulated by pretreatment with high, medium and low concentration ICA in a concentration-dependent manner, above effects could be blocked by LY294002 (all P<0.05). (7) The expression of P53 was significantly higher in GSNO group than in the blank control group (P< 0.05), which could be significantly down regulated by pretreatment with high, medium and low concentration ICA in a concentration-dependent manner, above effects could be blocked by LY294002(all P<0.05). (8) The expression of CYC and caspase-3 was significantly reduced in the mitochondria and increased in cytoplasm post GSNO treatment compared to blank control group, which could be reversed by pretreatment with high, medium and low concentration ICA(all P<0.05). (9) The expression of eNOS/p-eNOS was similar between GSNO and the blank control group, while it was significantly upregulated by pretreatment with high, medium and low concentration ICA and this effect could be blocked by LY294002(all P<0.05).

CONCLUSION

Icariin could reduce GSNO induced endothelial cell apoptosis through activating AKT pathway and downregulating P53 activity.

Hypoxia decreased chemosensitivity of breast cancer cell line MCF-7 to paclitaxel through cyclin B1

Hypoxia, frequently found in the center of solid tumors, may lead to enhance the production of key factor in cell survival, invasion, angiogenesis and loss of apoptosis. The low oxygen tension in hypoxic tumors is also known to interfere with the efficacy of chemotherapy, but the underlying mechanisms are not very clear. Paclitaxel (PTX) is an active agent used in breast cancer chemotherapy, which disturbs microtubule dynamics and impairs the transition of cells from metaphase to anaphase in mitosis, leading to cell death by apoptosis. In the present study, we try to determine whether hypoxia can decrease the chemosensitivity of human breast carcinoma cells to PTX and elucidate the underlying mechanism. We found that hypoxia could decrease PTX-induced cell death and G(2)/M arrest. Furthermore, our results showed that hypoxia inhibit PTX-induced soluble tubulin polymerized. In addition, we also found hypoxia could suppress PTX-induced cell cycle protein-cyclin B1 expression in MCF-7 cells. To further investigate whether the inhibitory effect of hypoxia on PTX-induced cell death is mediated by decreasing levels of cyclin B1, cyclin B1-transfected MCF-7 cells were used under hypoxic condition. The data showed that the hypoxia-based decreasing chemosensitivity of breast cancer cells to PTX was reversed by cyclin B1. We also found that overexpression of cyclin B1 could significantly increase the sensitivity of MCF-7 cells to PTX by stimulating soluble polymerized tubulin. Overall, hypoxia decreases cyclin B1, which could in turn reverse hypoxia-induced decreasing chemosensitivity to PTX in breast cancer cell line MCF-7.

[Study on the psychological character of pregnant women and nursing applications]

This study was conducted to explore the psychological character of healthy pregnant women. 81 four to ten months pregnant and 96 non pregnant women participated the study. SCL-90 was used to measure the psychological health state. The result showed that the average total and subtotal scores such as compulsion, sensitivity, stress, hostility, terror, obstinate, and psychiatric factor in pregnant women were obvious higher than in non pregnant women (P < 0.05 or P < 0.01). It indicated that pregnant women's psychological health state was not good. The major influencing factor was unhealthy characteristic type. It recommends that nurses should give advice and care to the pregnant women according to the individual's unhealthy psychological character to benefit both the mother and baby.

[Antigen signature analysis of dengue-2 viruses strains in Hainan China]

In this paper, we try to define the extent of antigenic variation between dengue-2 viruses from Hainan province, which had been isolated over a period of 3 years (1985-1987). The dengue-2 viruses were compared with the prototype New Guinea B strain and were subjected to antigen signature analysis. Eight strains of dengue-2 virus were analyzed by three monoclonal antibodies: flavivirus group, subcomplex dengue-2 type-specific reactive epitopes, over a range of antigen concentration. Five out of eight dengue-2 virus strains showed them to be antigenically homogeneous, and the remaining three strains showed them to be heterogeneous. Signature analysis provides a rapid and simple means to different strains derived from different sources, thus permit monitoring changes or introductions of hew dengue virus populations in certain geographic region.