Clinical characteristics of imported patients infected with 2019 novel coronavirus Omicron variants and Delta variants in Guangzhou City / 中华传染病杂志

Objective:To analyze and compare the clinical characteristics and prognosis of imported patients infected with 2019 novel coronavirus (2019-nCoV) Omicron variants and Delta variants, so as to provide references for clinical diagnosis, treatment and epidemic prevention strategies.Methods:The patients with imported 2019-nCoV infection from August 1, 2021 to January 18, 2022 in Guangzhou Eighth People′s Hospital, Guangzhou Medical University were retrospectively analyzed. According to the whole genome sequencing of 2019-nCoV in nasal or throat swabs, they were divided into Omicron group and Delta group. The clinical characteristics, laboratory tests, antibody levels, viral nucleic acid (the cycle threshold (Ct) of N gene and open reading frame ( ORF) 1 ab), main treatment measures and clinical prognosis were analyzed in the two groups. Statistical analysis was performed using the rank sum test, chi-square test or Fisher′s exact test. Results:A total of 344 cases were enrolled, including 152 cases in the Delta group and 192 cases in the Omicron group, and there were 240 males (69.8%), with a median age of 33 years old. One hundred and two (29.7%) of those patients had underlying disease.Two hundred and seventy-one had completed full or booster vaccination. The overall full vaccination rate in Omicron group was 70.8%(136/192), which was higher than 51.3%(78/152) in Delta group. The proportion of mild patients in Omicron group was higher than that in Delta group (57.3%(110/192) vs 24.3%(37/152), respectively), and the proportions of common type and severe type were lower than those of the Delta group (33.9%(65/192) vs 55.3%(84/152) and 0(0/192) vs 10.5%(16/152)), the differences were all statistically significant ( χ2=37.64 and 15.84, respectively, Fisher′s exact test; all P<0.001). The duration and peak of fever in Omicron group were 1.5(1.0, 2.0) d and 38.1(37.8, 38.5) ℃, respectively, which were lower than those in Delta group (3.0(1.0, 4.8) d and 38.5(38.1, 39.0) ℃, respectively), and the differences were both statistically significant ( Z=-4.14 and -3.85, respectively, both P<0.001). The 2019-nCoV antibody IgG and the Ct values of virus nucleic acid N gene and ORF1 ab gene in the vaccinated Omicron group at admission were higher than those in the Delta group ( Z=-3.25, -2.18 and -2.82, respectively, all P<0.050). Compared with patients in Delta group, patients in Omicron group had lower proportion of receiving respiratory therapy support, shorter oxygen therapy time, shorter reversion time from admission to nucleic acid Ct value≥35 and shorter hospitalization time. The differences were all statistically significant ( χ2=47.86, Z=-5.41, -5.60 and -4.71, respectively, all P<0.001). There was no critical illness or 28-day death case in both groups. Conclusions:The severity of patients infected with Omicron variants is lighter than that of patients with Delta variants, and the viral nucleic acid has shorter conversion time, which is mainly related to the virulence of variant strain and vaccination.

Construction and fluorescence intensity of lipid ultrasound microbubbles with monoclonal antibody targeted to leukaemia inhibitory factor receptor / 中华超声影像学杂志

Objective To investigate fluorescence intensity of lipid ultrasound microbubbles constructed in vitro and targeted to leukaemia inhibitory factor receptor (LIFR) with a monoclonal antibody.MethodsThe LIFR-targeted ultrasound mierobubbles (MB-BSB-LIFR-AB) were constructed using a technology of biotin-avidin bridge.FITC labeled Avidin was incubated with lipid ultrasound microbubbles (MB) and biotinylated lipid microbubbles (MB-B).Two dilutions (1:4 and 1:16) of DTAF second antibody were incubated with four types of ultrasound microbubbles,including MB,MB-B,biotinavidin-MB (MB-BS),MB-BSB-LIFR-AB.The fluorescence intensity of microhubbles were graded as 0,1,2to 3.ResultsAfter incubating with FITC-avidin,MB-B displayed bright green fluorescence ( grade 3),but MB had no fluorescence ( grade 0).After incubating with two dilutions of DTAF second antibody (1:4 and 1:16),MB-BSB-LIFR-AB displayed brightest green fluorescence (grade 3) in both concentration,while MB-BS and MB-B only displayed dim green fluorescence (grade 1 ) at the dilution of 1:4,with MB displaying no fluorescence at either dilution (grade 0).Conclusions LIFR monoclonal antibody can be effectively conjugated to MB-B with biotin-avidin bridge.Fluorescence detection is a simple method for investigating the conjugation reliability of targeted lipid ultrasound microbubbles.

Adhesive behavior of dual-targeted microbubbles carrying both Sialyl Lewisx and anti-ICAM-1 monoclonal antibody in vitro / 中华超声影像学杂志

Objective To assess the adhesive behavior of dual-targeted microbubbles carrying both Sialyl Lewisx and anti-ICAM-1 monoclonal antibodies in vitro. Methods Selectin-targeted (with Sialyl Lewisx) microbubbles (MB-S),ICAM-1-targeted (with anti-ICAM-1 monoclonal antibodies) microbubbles (MB-Ⅰ),and dual-targeted (with both ligands) microbubbles(MB-D) were prepared by attaching the ligands to the biotinylated lipid-microbubbles via multi-step avidin biotin bridging chemistry. A parallel plate flow chamber combined with a novel automated tracking algorithm,were used to analyze the transient velocities,rolling and firmly adherent numbers of microbubbles at various shear stress (0. 6,2.0 and 4.0 dyn/cm2)over 6 min. Microbubbles detachments were tested by ramping up the shear stress at 30 s intervals. Results At 0.6 dyn/cm2 shear stress, the rolling numbers of MB-S and MB-D were remarkably more than that of MB-I( P＜0.05), while at 2.0 and 4.0 dyn/cm2 MB-S performed higher rolling efficiency as compared with either MB-I and MB-D ( P＜ 0.05). In all flow conditions, the adhesive numbers of MB-D to the targets were obviously greater than those of MB-S and MB-I ( P＜ 0.05). Half-maximal detachment decreased gradually in MB-I, MB-D and MB-S by turns ( P＜ 0.05). Conclusions MB-I, MB-S and MB-D have different adhesive behaviors. MB-I exhibites primarily firm adhesion with low rolling efficiency, while MB-S reveales unstable or transient adhesion with high rolling efficiency,and MB-D exhibites firm adhesion with high rolling efficiency. MB-D may be suitable for molecular imaging in high-flow vessels.

Preparation and evaluation of nanometer-scale bubbles with surfaces of N-palmitoyl chitosan / 中华超声影像学杂志

Objective To develop nanometer-scale bubbles with surfaces of N-palmitoyl chitosan(PLCS) as ultrasound contrast agent and evaluate its characteristics and acoustic effects in vivo. Methods The PLCS nanobubbles were prepared using a cutting technique at differential high-frequency of shear speed. Both optical and transmission electron micrography were performed to determine the nanobubble size and morphology. Concentration, size-distribution and zeta potential of the PLCS nanobubbles were measured by cell counting chamber, Malvern lazer particle analyzer and zeta-sizer at 1-day, 45-day and 90-day. The acoustic effects of the PLCS nanobubbles on myocardium and renal tissue in 6 normal rats were observed using bolus infusion of the nanobubbles intravenously. The maximum video intensity(VI) was measured.Results The PLCS nanobubbles with nice round-shape and uniform site-distribution were demonstrated.The mean diameter,concentration and zeta potential of the PLCS nanobubbles were (617 ± 12) nm, (7.2 ±0.6) × 109/ml and (52.9 ± 1.3)mV at the 1-day,and all of parameters did not change significantly in 45-day and 90-day ( P ＞ 0. 05). A significant contrast-enhancement was noted on myocardium and renal tissue during infusion of the nanobubbles. VI on both tissues was (15.6 ± 1.1)GU and (27.3 ± 2.5)GU,respectively. The visual contrast-enhancement last up to (10 ± 2)min. Conclusions The PLCS nanometerscale bubbles have excellent physical-features and contrast-enhanced ultrasound effects in vivo. It may develop as a novel contrast ultrasound agent which could cross endothelial cell membrances.

Binding capability of microbubbles targeted to VCAM-1 under pulsatile high-shear flow conditions / 中华超声影像学杂志

Objective To assess the binding capability of microbubbles targeted to VCAM-1 using the parallel plate flow chamber mimic the pulsatile high-shear flow conditions of artery. Methods Targeted microbubbles were designed by conjugating monoclonal antibodies against mouse VCAM-1 to the lipid shell of the microbubbles via an "avidin-biotin" bridge. The binding and retention of targeted microbubbles to VCAM-1 (MBv) immobilized on a culture dish were assessed in a flow chamber at variable shear stress (0.5～ 16.0 dynes/cm2 ). The pulsatile flow conditions were generated and compared to the continuous flow conditions. The retentive ability of MBv was evaluated by the detachment test. Results The marked binding of MBv were seen in pulsatile and continuous flow conditions at low-shear flow conditions of 0.5 ～ 2dyn/cm2 ,but the binding rate in the pulsatile flow group was higher ( P ＜0. 05) than that in the continuous flow conditions. Furthermore,the marked binding of MBv was still noted at the highest shear rates (4～8dyn/cm2) under pulsatile flow conditions, while it was not observed under continuous flow conditions. The half detachment rate of MBv was high up to (20.7 ± 3. 1)dyn/cm2. Conclusions The targeted microbubbles binding to VCAM-1 specific and effective at high-shear stress under pulsatile flow conditions. The molecular ultrasound imaging can be potentially used in the high-shear conditions artery system.

Visually assessment of matrigel angiogenesis with ultrasound molecular imaging using microbubbles targeted to endothelial αv-integrins / 中华超声影像学杂志

Objective To explore the feasibility of visually assessment of angiogenesis in a murine model of subcutaneous matrigel plugs with ultrasound molecular imaging(UMI) using microbubbles(MB)targeted to endothelial αv-integrins. Methods Matrigel angiogenesis was created by subcutaneous implantation of FGF-2 enriched matrigel in 10 mice. On day 10, UMI of the matrigel was performed in all mice at 6 minutes after intravenous injection of either αv-integrin targeting microbubbles(MBα) or isotype control microbubbles(MBc) in random with 30 min interval,and the video intensity(Ⅵ) was measured. To further test the specificity of the signal coming from MBα,antibody against αv-integrin was injected 10 min before microbubbles injection. Following UMI,all matrigels were harvested for histological analysis. Results As expected,VI of the matrigel was significantly higher ( P ＜0.05) for MBα (20. 5 ± 3.3)U as compared with MBc (4. 8 ± 1.5)U. After blocking with antibody against αv-integrin,a great decrease was observed in the MBα group [VI (4.6 ± 1.2) U, P ＜0.05] while no significant difference was noted for MBc [VI (4. 9 ±1.5)U, P ＞ 0.05 ]. Neovessels within matrigel was positive for αv-integrin. Conclusions UMI with microbubbles targeted to αv-integrins can be effective and specific in evaluating the angiogenesis in a murine model of subcutaneous matrigel plugs.

The impact of nursing intervention on negative moods, compliance behavior and life quality of patients with chronic heart failure / 中国实用护理杂志

Objective To explore the impact of nursing intervention on negative moods, compliance behavior and life quality of patients with chronic heart failure (CHF). Methods We randomized 100 patients with CHF into the observation group and the control group. The control group only accepted basic nursing, life nursing and treatment; besides these, the observation group were given other interventions, including health education, comfortable environment, physical activity, compliance behavior, diet and mental guidance 3 days after the patients were admitted into hospital. The two groups were tested for anxiety, depression, compliance behavior as well as life quality with Minnesota Living with Heart failure questionnaire both 3 days after the patients were admitted into hospital and when they were discharged. χ2 test and t test were used to analyze the data. Results Before intervention, there were no statistical difference in their anxiety, depression, compliance behavior, and life quality between the observation group and the control group. After intervention, the observation group was superior than the control group in anxiety and depression score, compliance behaviors including on-time medicine administration, regular recheck, rational diet, smoke abatement and alcohal restriction, physical activity, life quality score including physical limitation, emotion, symptom and social constrain. Conclusions Nursing intervention could help improve anxiety and depression of the patients with CHF, promote their compliance behaviors and improve their life quality.

Relationship between optic disc hemorrhage and localized retinal nerve fiber layer defect in normal-tension glaucoma / 中华眼底病杂志

Objective To investigate the relationship between optic d isc hemorrhage and localized retinal never fiber layer defects (RNFLDs) in norma l-tension glaucoma. Methods In 83 patients with normal-tensi on glaucoma, the cumulative frequency and quadrantal distribution of optic disc hemorrhages were retrospectively analyzed. The neighboring relation between opti c disc hemorrhages and RNFLDs in a same quadrant and the changes of correspondin g retinal never fiber layer (RNFL) after the occurrence of optic disc hemorrhage s were observed by tridimensional photochromy of ocular fundus. Results (1) The occurrences and distribution of optic disc hemorrhages: 29 of 83(34.94%) patients (33 eyes) had totally 58 occurrences, including 39 in infer iotemporal area, 14 in superiotemporal area, and 5 in other area. (2) The relati onship of neighborhood between optic disc hemorrhages and RNFLDs: in the availab le tridimensional photochrome, 23 occurrences in 15 patients (16 eyes) were foun d with cuneiform RNFLDs in the same quadrant, in which 22 was near the border of cuneiform RNFLDs. (3) The changes of corresponding retinal never fiber layer (R NFL) after the occurrence of optic disc hemorrhages: the photochromes of 24 occu rrences in 20 patients (21 eyes) were kept well in the initial and the 2-year f ollow-up periods, while the changes of RNFL were found in each region correspon ding to the 19 occurrences (in inferiotemporal or superiotemporal area) in the i nitial photochrome, including 7 cuneiform defects with various sizes, and 12 dev eloped localized RNFLDs next to the initial hemorrhages in the optic disc. No ob vious localized RNFL corresponding to the other 5 occurrences (1 in inferiotempo ral, 1 in superiotemporal, and 3 in other areas) were found in the follow-up pe riod. Conclusion Optic disc hemorrhages in normal-tension gla ucoma occur mostly in inferiotemporal area, and secondly in superiotemporal area of optic disc, and the appearance of optic disc hemorrhages may suggest that th e localized RNFLDs would develop in the associated regions.