BACKGROUND:Molecular stability and biocompatibility of hemerythrin surpass those of human and mammalian hemoglobin,making it a potential candidate for a safer and more effective erythrocyte substitute after modification.OBJECTIVE:To prepare multi-modified hemerythrin nanoparticles,characterize them,and test their performance in vitro.METHODS:The hemerythrin of Sipunculus sphenodontus was separated and purified by tangential flow ultrafiltration.The intramolecular cross-linking was completed by genipin.The nanoparticles were encapsulated by dopamine,and passivated by polyethylene glycol to obtain multi-modified hemerythrin nanoparticles.The physicochemical properties of the nanoparticles were characterized.Hemerythrin nanoparticles,hemerythrin,and hemoglobin oxygen carrier HBOC-201 with different mass concentrations(0,0.25,0.5,1.0,and 2.0 mg/mL)were incubated with macrophages for 6 and 24 hours,and with endothelial cells for 24 hours.The cell survival rate was detected by CCK-8 assay.The levels of nitric oxide and vascular cell adhesion factor 1 in the culture medium of endothelial cells were detected by ELISA.RESULTS AND CONCLUSION:(1)Under electron microscopy,hemerythrin nanoparticles were ellipsoidal,with a dense outer membrane and a relatively uniform internal texture.The particle size was(150.12±1.67)nm;the dispersion index was 0.21±0.03;the Zeta potential was(-24.54±2.61)mV;the half-saturated oxygen partial pressure was(0.97±0.15)kPa,and the Hill coefficient was 1.49±0.16.(2)After incubation for 6 hours,within the mass concentration range of≤1.0 mg/mL,the survival rates of macrophages in the hemerythrin nanoparticle group,the hemerythrin group,and the HBOC-201 group were all above 85%.At a mass concentration of 2.0 mg/mL,only the survival rate of macrophages in the hemerythrin nanoparticle group was above 80%.After incubation for 24 hours,the survival rates of macrophages in the three groups were all lower than 80%,among which the survival rate of macrophages in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and the HBOC-201 group(P<0.05).(3)With the increase of drug concentration,the survival rate of vascular endothelial cells in the three groups decreased.At 1.0 mg/mL or 2.0 mg/mL mass concentration,the survival rate of cells in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).At the same mass concentration,the nitric oxide level in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).In the range of 0.25-2.0 mg/mL mass concentration,the vascular cell adhesion factor 1 level in the hemerythrin nanoparticle group was lower than that in the hemerythrin group and HBOC-201 group(P<0.05).(4)The results showed that the hemerythrin nanoparticles modified with intramolecular cross-linking and polydopamine/polyethylene glycol had good oxygen-carrying activity in vitro,better anti-phagocytic performance,and less cytotoxicity.

BACKGROUND:Molecular stability and biocompatibility of hemerythrin surpass those of human and mammalian hemoglobin,making it a potential candidate for a safer and more effective erythrocyte substitute after modification.OBJECTIVE:To prepare multi-modified hemerythrin nanoparticles,characterize them,and test their performance in vitro.METHODS:The hemerythrin of Sipunculus sphenodontus was separated and purified by tangential flow ultrafiltration.The intramolecular cross-linking was completed by genipin.The nanoparticles were encapsulated by dopamine,and passivated by polyethylene glycol to obtain multi-modified hemerythrin nanoparticles.The physicochemical properties of the nanoparticles were characterized.Hemerythrin nanoparticles,hemerythrin,and hemoglobin oxygen carrier HBOC-201 with different mass concentrations(0,0.25,0.5,1.0,and 2.0 mg/mL)were incubated with macrophages for 6 and 24 hours,and with endothelial cells for 24 hours.The cell survival rate was detected by CCK-8 assay.The levels of nitric oxide and vascular cell adhesion factor 1 in the culture medium of endothelial cells were detected by ELISA.RESULTS AND CONCLUSION:(1)Under electron microscopy,hemerythrin nanoparticles were ellipsoidal,with a dense outer membrane and a relatively uniform internal texture.The particle size was(150.12±1.67)nm;the dispersion index was 0.21±0.03;the Zeta potential was(-24.54±2.61)mV;the half-saturated oxygen partial pressure was(0.97±0.15)kPa,and the Hill coefficient was 1.49±0.16.(2)After incubation for 6 hours,within the mass concentration range of≤1.0 mg/mL,the survival rates of macrophages in the hemerythrin nanoparticle group,the hemerythrin group,and the HBOC-201 group were all above 85%.At a mass concentration of 2.0 mg/mL,only the survival rate of macrophages in the hemerythrin nanoparticle group was above 80%.After incubation for 24 hours,the survival rates of macrophages in the three groups were all lower than 80%,among which the survival rate of macrophages in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and the HBOC-201 group(P<0.05).(3)With the increase of drug concentration,the survival rate of vascular endothelial cells in the three groups decreased.At 1.0 mg/mL or 2.0 mg/mL mass concentration,the survival rate of cells in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).At the same mass concentration,the nitric oxide level in the hemerythrin nanoparticle group was higher than that in the hemerythrin group and HBOC-201 group(P<0.05).In the range of 0.25-2.0 mg/mL mass concentration,the vascular cell adhesion factor 1 level in the hemerythrin nanoparticle group was lower than that in the hemerythrin group and HBOC-201 group(P<0.05).(4)The results showed that the hemerythrin nanoparticles modified with intramolecular cross-linking and polydopamine/polyethylene glycol had good oxygen-carrying activity in vitro,better anti-phagocytic performance,and less cytotoxicity.

Objective:To compare the effectiveness of cylindrical-shaped and conical-shaped cuff catheters for airway closure using different pressure measurement methods at the lowest safe pressure and to guide the clinical application.Methods:Twenty-four patients with endotracheal intubation admitted to the intensive care unit (ICU) of Guangxi Medical University Cancer Hospital from December 2021 to January 2022 were enrolled. Leakage test in vitro was performed on the secretion on the patients' cuff. The needle and plunger from 20 mL syringe was separated, the syringe was sealed with adhesive, and the syringe nozzle was filled thoroughly to create a tracheal model. Consecutively, both cylindrical-shaped and conical-shaped cuff catheters were inserted into the simulated trachea, and the cuff pressure was calibrated to 20 cmH 2O (1 cmH 2O≈0.098 kPa) before commencing the experiment. The viscosity of the secretion on the patients' cuff was classified (grade Ⅰ was watery subglottic secretion, grade Ⅱ was thick subglottic secretion, grade Ⅲ was gel-like subglottic secretion), and the same viscosity secretion was injected into the catheter cuff. Utilizing a self-control approach, intermittent pressure measurement was initially conducted on both the cylindrical-shaped and conical-shaped cuff by improved pressure measurement method (intermittent pressure measurement group), followed by continuous pressure measurement experiment (continuous pressure measurement group). The leakage volume of the three viscosity subglottic secretions and the values of cuff pressure measurement of different shaped cuff catheters at 4, 6, 8 hours of inflation were recorded. Results:A total of 180 retention samples were extracted from 24 patients with tracheal intubation during ventilation, with 90 samples in each of the two groups using different pressure measurement methods, and 30 samples of retention materials with different viscosities in each group. In the intermittent pressure measurement group, at 4 hours of inflation, all samples of secretion with grade Ⅰ and grade Ⅱ on cylindrical-shaped cuff leaked, while 3 samples of secretion with grade Ⅲ also leaked. For conical-shaped cuff, 28 samples of secretion with grade Ⅰ leaked, only 2 samples of secretion with grade Ⅱ leaked, and there was no leak for secretion with grade Ⅲ. At 6 hours of inflation, all samples of the three viscosity secretions on different shaped cuffs leaked. The leakage was gradually increased with the prolongation of inflation time. In the continuous pressure measurement group, at 4 hours of inflation, all samples of secretion with grade Ⅰ on cylindrical-shaped cuff leaked, while 29 samples of secretion with grade Ⅱ leaked, and there was no leak for secretion with grade Ⅲ. For the conical-shaped cuff, 26 samples of secretion with grade Ⅰ leaked, and there was no leak for secretion with grade Ⅱ and grade Ⅲ. At 6 hours of inflation, the conical-shaped cuff still had no leak for secretion with grade Ⅲ. As the inflation time prolonged, the leakage of subglottic secretion on different shaped cuffs in both groups was gradually increased. At 8 hours of inflation, all samples experienced leakage, but the leakage of subglottic secretion on different shaped cuffs in the continuous pressure measurement group was significantly reduced as compared with the intermittent pressure measurement group [leakage for secretion with grade Ⅲ (mL): 1.00 (0.00, 1.25) vs. 2.00 (1.00, 2.00) on the cylindrical-shaped cuff, 1.00 (0.00, 1.00) vs. 2.00 (2.00, 2.00) on the conical-shaped cuff, both P < 0.01]. The values of pressure measurement of cuffs with different shapes at different time points of inflation in the continuous pressure measurement group were within the set range (20-21 cmH 2O). The cuff pressure at 4 hours of inflation in the intermittent pressure measurement group was significantly lower than the initial value (cmH 2O: 18.3±0.6 vs. 20.0±0.0 in the cylindrical-shaped cuff, 18.4±0.6 vs. 20.0±0.0 in the conical-shaped cuff, both P < 0.01), and the cuff pressure in both shaped cuffs showed a significant decrease tendency as inflation time prolonged. However, there was no statistically significant difference in values of pressure measurement between the different shaped cuff catheters. Conclusions:Continuous pressure monitoring devices can maintain the effective sealing of conical-shaped cuff catheters at the lowest safe pressure. When using an improved pressure measurement method for intermittent pressure measurement and/or using a cylindrical cuff catheter, the target pressure should be set at 25-30 cmH 2O, and the cuff pressure should be adjusted regularly.

Objective::This survey was designed to understand the misconceptions about labor epidurals.Methods::This voluntary and anonymous online survey on wenjuan.com was conducted from September 1 st, 2015 to January 1 st, 2016 via mainly WeChat groups dedicated to perinatal healthcare providers in China. The questionnaire included items inquiring the knowledge and opinions about labor epidural analgesia related to maternal complications, baby safety, and effect on laboring. Incomplete surveys were excluded from the data analysis. The data was presented as percentages and a Chi-square test or Fisher’s exact test, as appreciate, was used to quantitatively compare the results. Results::A total of 1412 respondents completed surveys with 42.9% (606/1412) of them being anesthesiologists, 35.1% (495/1412) being obstetricians, 11.8% (167/1412) being midwives, 3.7% (52/1412) being labor and delivery nurses, and 6.5% (92/1412) being hospital administrators and unspecified. The study revealed a lack of knowledge in labor pain control. Although 82.4% (1164/1412) of respondents were familiar with labor epidural analgesia, 8.9% (126/1412) did not know how it works, and 1.1% (15/1412) never heard it in a multiple-choice question. The three main groups (anesthesiologists, obstetricians, and midwives/labor and delivery nurses) were chosen for comparisons. Opinions among these three groups concerning five questions in the three main concerns were evaluated using a statistical significance of P<0.05. Conclusion::The results in our survey indicated an urgent need of continuing medical education to multidisciplinary specialties to improve evidence-based medical practices as these misconceptions have existed for over 10 years in the medical professionals. Lack of public awareness fueled by misconceptions related to labor epidural analgesia may be associated with a lack of professional knowledge. Correct knowledge in professionals needs to be disseminated to the public in order to dispel possible misconceptions and rumors about labor epidural analgesia. This would not only enhance patient understanding of their care but also improve maternal, fetal, and neonatal outcomes.

Objective::This survey was designed to understand the misconceptions about labor epidurals.Methods::This voluntary and anonymous online survey on wenjuan.com was conducted from September 1 st, 2015 to January 1 st, 2016 via mainly WeChat groups dedicated to perinatal healthcare providers in China. The questionnaire included items inquiring the knowledge and opinions about labor epidural analgesia related to maternal complications, baby safety, and effect on laboring. Incomplete surveys were excluded from the data analysis. The data was presented as percentages and a Chi-square test or Fisher’s exact test, as appreciate, was used to quantitatively compare the results. Results::A total of 1412 respondents completed surveys with 42.9% (606/1412) of them being anesthesiologists, 35.1% (495/1412) being obstetricians, 11.8% (167/1412) being midwives, 3.7% (52/1412) being labor and delivery nurses, and 6.5% (92/1412) being hospital administrators and unspecified. The study revealed a lack of knowledge in labor pain control. Although 82.4% (1164/1412) of respondents were familiar with labor epidural analgesia, 8.9% (126/1412) did not know how it works, and 1.1% (15/1412) never heard it in a multiple-choice question. The three main groups (anesthesiologists, obstetricians, and midwives/labor and delivery nurses) were chosen for comparisons. Opinions among these three groups concerning five questions in the three main concerns were evaluated using a statistical significance of P<0.05. Conclusion::The results in our survey indicated an urgent need of continuing medical education to multidisciplinary specialties to improve evidence-based medical practices as these misconceptions have existed for over 10 years in the medical professionals. Lack of public awareness fueled by misconceptions related to labor epidural analgesia may be associated with a lack of professional knowledge. Correct knowledge in professionals needs to be disseminated to the public in order to dispel possible misconceptions and rumors about labor epidural analgesia. This would not only enhance patient understanding of their care but also improve maternal, fetal, and neonatal outcomes.

Pulmonary fluid refers to a thin and continuous liquid layer mainly consisting of airway mucus and lining liquid on the inner surface of alveoli, which is essential for maintaining a healthy lung. The clinical significance of rheological properties of pulmonary fluid in airway stability, pulmonary barrier and clearance functions, ventilator induced lung injury and surfactant replacement therapy in infant respiratory distress syndrome was introduced in this paper. Furthermore, a variety of classical methods for measuring surface tension and liquid viscosity, such as Langmuir-Wilhelmy balance, captive bubble method, glass capillary viscometer and rotational viscometer, and emerging techniques (e.g. particle tracking microrheometer and axisymmetric drop shape analysis) were reviewed, and their advantages and drawbacks were also compared, in order to provide an important reference for the assisted diagnosis and treatment of lung diseases in clinical practice.

Objective:To Investigate the correlation of eosinophil count and stroke-associated pneumonia (SAP) in patients with acute ischemic stroke.Methods:Patients with acute ischemic stroke within 24 h after onset admitted to the Department of Encephalopathy, Suzhou Integrated Traditional Chinese and Western Medicine Hospital from August 2016 to September 2018 were enrolled prospectively. Their general clinical data and eosinophil counts were collected. National Institutes of Health Stroke Scale (NIHSS) was used to assess the severity of stroke. Multivariate logistic regression analysis was used to determine the independent risk factors for SAP. Results:A total of 521 patients were enrolled, including 106 (20.35%) SAP. Univariate logistic analysis showed that SAP was associated with the classification of eosinophil count (odds ratio [ OR] 0.37, 95% confidence interval [ CI] 0.20-0.68; P=0.001), and tended to be associated with eosinophil count ( OR 0.08, 95% CI 0.01-1.01; P=0.051). Multivariate logistic regression analysis showed that both eosinophil count and eosinophil count classification were not the independent risk factors for SAP, and advanced age ( OR 1.077, 95% CI 1.045-1.109; P< 0.001), chronic obstructive pulmonary disease ( OR 6.931, 95% CI 1.295-37.106; P=0.024) and high baseline NIHSS score ( OR 1.148, 95% CI 1.003-1.314; P=0.045) were significantly independently associated with SAP. Conclusions:Eosinophil count was not an independent predictor of SAP in patients with acute ischemic stroke.

Objective To establish a pseudovirus system for phenotypic drug-resistance detection and provide a relatively cheap and easy method for drug-resistance testing. Methods EGFP gene was amplified from plasmid pSV-EGFP and then cloned to backbone plasmid pNL4-3.Luc. E-R-by double enzyme digestion;env gene was amplified from RNA isolated from HIV-1-infected persons and cloned to eukaryotic expression plasmid cells and EGFP or ENV expression. Pseudovirus was produced by co-transfection of two recombinant plasmids to 293t cells. Infection of pseudovirus was determined by co-cultured with TZM-b1 cells and immunofluorescent test. Results Two recombinant plasmids(mass ratio,pcDNA3.1-env:pNL4-3.EGFP.E-R-.=2:1)were co-transfected to 293t cells. Cultured supernatants containing pseudovirus were harvested at 48 h post-transfection. Fluorescence was observed in TZM-b1 cells after TZM-b1 cells were infected with pseudovirus at 48 h post-infection. Conclusion The recombinant pseudovirus carrying EGFP gene is constructed successfully and it could be used for phenotypic drug-resistance detection.

Objective To evaluate the reliability of the panoramic radiographs for diagnosing mandibular asymmetry.Methods A total of 25 cases with no asymmetry in chief complaint or in appearance were selected for symmetry group.Pa and PAC from 16 cases of facial asymmetry were selected for asymmetric group.Marker points were fixed,a reference line and the reference plane drawn,and then relevant measurement items determined.The repeatability of the fixed position was observed.The difference of all measurement items between the left and right on Pa in symmetry group and asymmetric group were compared respectively and the asymmetric rate of corresponding measuredvalues on two sides between two groups were observed too.Correlation test was used to evaluate the measured-values on Pa and PAC in asymmetric group.Results Dispersion became smaller with the help of reference line and reference plane.And the dispersion was larger when Me was used as a marker other than MF.Most measured-values in symmetry group on Pa and all measured-values in asymmetric group on Pa showed statistically significant difference (P＜ 0.05).The mean difference of CP-GoP distance representing the vertical measured-value was 4.73 mm (P＜0.01); and the mean difference of GoP-MF distance representing the horizontal measured-value was 5.77 mm (P＜0.01).The horizontal measurements on PA and PAC showed closer correlation (r=0.78～0.85,P＜0.01) while the vertical was poorer (r=0.64,P＜0.01).Conclusions This study suggests that marking assisted with reference line and reference plane could get a more repeatable fixed-point on Pa.MF point could be used as a fixed-point for measuring mandibular asymmetry on Pa and the Pa measurement can be used to evaluate mandibular asymmetry.

OBJECTIVE: To explore the changes of mTOR signal pathway in HeLa cells under different nutritional conditions infected with Coxsackie virus B3 (CVB3). METHODS: The HeLa cells were cultured with two methods: the conventional culture method cultured HeLa cells with medium with 10% fetal bovine serum for 24 h and changed the medium next day, and then infected with CVB3; the serum starvation method cultured HeLa cells with medium without fetal bovine serum for 24 h, and then infected with CVB3. The expression of the coat protein of CVB3, mTOR, p70S6K mRNA was detected with RT-PCR at different time points. RESULTS: The virus group showed the expressions of mTOR and p70S6K mRNA were significantly higher than those in the control group at 12 h and 24 h (P<0.05) in the conventional culture. The virus group showed the expressions of mTOR and p70S6K mRNA were lower than those in the control group (all P<0.05) in the starvation serum. The expression of mTOR mRNA in the starvation serum virus group was higher than that in the conventional culture virus group (all P<0.05) and the control group. The expression of p70S6K mRNA was not significantly different in the two groups (P>0.05). CONCLUSION CVB3 can down-regulate the expressions of mTOR and p70S6K mRNA. The mTOR expression in the starvation serum is higher than that in the conventional culture.
Cell Culture Techniques ; Down-Regulation ; Enterovirus B, Human ; pathogenicity ; HeLa Cells ; Humans ; RNA, Messenger ; genetics ; metabolism ; Signal Transduction ; physiology ; TOR Serine-Threonine Kinases ; genetics ; metabolism