OBJECTIVE: To explore the chronic injury and its possible mechanism of ionizing radiation on multipotent hematopoietic progenitor cells (MPPs) by determining the related indicators of MPPs in bone marrow of mice post-radiation. METHODS: Sixteen C57BL/6 adult mice were randomly divided into normal control and irradiation groups, 8 mice in each group. The mice in irradiation group were exposed to 6 Gy X-ray. The proportion of bone marrow MPPs, their apoptosis and proliferation 2 months after irradiation were detected by flow cytometry. Mitochondrial activity and levels of reactive oxygen species (ROS) in each MPPs population were detected by Mitotracker Red and DCFDA probes, and the senescent state of MPPs in the bone marrow was analyzed. RESULTS: Ionizing radiation could reduce the proportion of MPPs in mouse bone marrow. The proportions and numbers of MPP1, MPP3 and MPP4 in the bone marrow were significantly decreased after whole-body irradiation with 6 Gy X-ray (P<0.05). In addition, radiation significantly reduced the colony-forming capacity of MPPs in bone marrow (P<0.05), the proportions of apoptotic cells in the MPP1 and MPP4 cell populations increased significantly in the bone marrow (P<0.05). The activity of mitochondria was significantly reduced in the bone marrow MPP2, MPP3 and MPP4 cell populations compared with that of the control group (P<0.05). It was also found that the radiation could significantly increase the ROS levels of MPPs in bone marrow, and the content of ROS in the MPP2, MPP3 and MPP4 cell population of the bone marrow was significantly increased(P<0.05). The senescent cells ratios of MPP1, MPP3 and MPP4 cells in the bone marrow after irradiation were significantly higher than those in the control group (P<0.05). CONCLUSION Ionizing radiation can cause chronic MPPs damage in mice, which is closely associated with persistent oxidative stress, cells apoptosis, and cellular senescence.
Mice ; Animals ; Bone Marrow ; Reactive Oxygen Species ; Mice, Inbred C57BL ; Hematopoietic Stem Cells ; Whole-Body Irradiation ; Radiation, Ionizing ; Bone Marrow Cells

This study evaluated the scientific nature and effectiveness of iterative optimization of prevention and control measures for local outbreaks caused by the BA.2 and BA.5.2 COVID-19 strains in Fujian Province in 2022,to provide a scientif-ic basis for responding to future new or recurrent respiratory infectious diseases.According to the theory of infectious disease dynamics,relevant information regarding the local epidemic situation caused by the BA.2 sub-type Omicron virus strain in March 2022 and BA.5.2 sub-type Omicron virus strain in October 2022 in Fujian Province was collected.The susceptible exposed infectious removed(SEIAR)model of COVID-19 infection with a latent period and asymptomatic infected persons was used to analyze the transmission dynam-ics of two local epidemic situations,and evaluate the preven-tion and control effects.The incubation period of the BA.2 epidemic was 3 days(1～9 days),the intergenerational inter-val was 3 days(1～5 days),and the initial Rt was 3.0(95％CI:2.7～3.3).The incubation period of the BA.5.2 epidemic was 2 days(1～6 days),the intergenerational interval was 1 day(0～2 days),and the initial R,was 1.9(95％CI:1.7～2.1).The fittingresults for the BA.2 and BA.5.2 epidemics were good,and no statistical difference was observed between the predic-ted and actual numbers of cases(x2BA.2=31.53,x2BA.5.2=27.88,P＞0.05).If an emergency response had not been initiated,the BA.2 epidemic would have continued to spread andpeak on April 7th,with an estimated 638 035 cases.The BA.5.2 epidemic would have rapidly spread,reaching a peak on November 14th,with an estimated 685 940 cases.If one incubation period were detected early,the scale of the BA.2 epidemic would have decreased by 25.73％;if two incubation periods were detected early,the scale would have decreased by 79.56％,and if one incubation period had been delayed,the scale would have expanded by 13.72％.If one incubation period had been detected early in the BA.5.2 epidemic,the scale would have decreased by 35.04％;if two incubation periods had been detected early,the scale would have decreased by 92.47％;and if one incubation period had been delayed,the scale would have increased by 19.75％.The guiding ideology,and the prevention and control measures for handling two local epidemics were optimized and iterated.Our study indicated that implementing the"four early"measures ef-fectively decreased the scale of the epidemic,and earlier detection was associated with more significant control effects.This study provides valuable information for the prevention and control of new or recurrent respiratory infectious diseases.

Background The chronic injury of the hematopoietic system caused by ionizing radiation (IR) is often ignored. The essential cause of this injury is the damage of hematopoietic stem and progenitor cells (HSPCs). Objective To explore the long-term effects of IR at different radiation doses and at different radiation fractions of the same radiation dose on HSPCs in the bone marrow of mice, and to provide a scientific basis for reducing the chronic damage to the hematopoietic system caused by IR. Methods A total of 16 male C57BL/6 mice aged 8-10 weeks were randomly divided into four groups that received different doses or fractions of total body X-ray irradiation, including 1.5 Gy×4 irradiation group (n=5), 3 Gy irradiation group (n=4), 6 Gy irradiation group (n=4), and non-irradiation group (n=3). Two months after irradiation, bone marrow cells from each mouse were collected and counted. The clone forming ability of bone marrow cells was analyzed by cobblestone area-forming cell (CAFC) assay. The proportion of HSPCs was measured by flow cytometry. The cell cycle of HSPCs was assessed by antigen identified by monoclonal antibody Ki 67 (Ki-67) and 7-amino-actinomycin D (7-AAD) double staining. The reactive oxygen species (ROS) levels of HSPCs were estimated with a 2,7-dichlorodihydrofluorescein diacetate (DCFDA) probe. The cellular senescence of HSPCs was evaluated with a 5-dodecanoylaminofluorescein di-β-D-galactopyranoside (C12FDG) probe. The expression of senescence related genes such as P16, P19, P21, and P27 was measured by real-time fluorescence quantitative PCR. Results There was no significant change in the numbers of bone marrow cells 2 months after different doses and fractions of radiation (P>0.05). The clone forming ability of bone marrow cells was significantly decreased after 3 Gy and 6 Gy irradiation when compared to non-irradiated mice (P<0.01). HSPCs responded inconsistently to different doses and fractions of irradiation. Overall, there was no significant change in long-term hematopoietic stem cells (LT-HSCs) proportion after irradiation (P>0.05), the proportions of hematopoietic progenitor cells (HPCs), hematopoietic stem cells (HSCs), short-term hematopoietic stem cells (ST-HSCs), and multipotent progenitors 2 (MPP2) increased after irradiation (P<0.05), and the proportions of LSK, MPP1, MPP3, and MPP4 cells decreased after irradiation (P<0.05); except for HPCs and MPP2, the proportion of HSPCs in G0 phase was decreased (P<0.05). The ROS production in HSPCs was increased significantly after 6 Gy irradiation (P<0.05), while the ROS levels after 3 Gy and 1.5 Gy×4 irradiation were similar to that of the non-radiation group (P>0.05). The cellular senescent proportion of HPCs, LSK, and HSCs increased after irradiation (P<0.05). The expression levels of senescence related genes P16, P19, and P21 in HSCs were significantly increased (P<0.05). Conclusion The responses of HSPCs in bone marrow to IR vary depending on doses and fractions of irradiation. Increased ROS production and cellular senescence may be involved in the damage process of HSPCs under radiation settings.

Objective: To explore the effect of fine particulate matter (PM_2.5) pollution on depression hospitalization cost and length of stay in 57 cities of China. Methods: A total of 84 207 patients with depression in 57 cities of China from January 2013 to December 2017 were selected as the subjects. The demographic characteristics and hospitalization status of the patients were obtained from the database of basic medical insurance for urban workers and urban residents in China. The environmental exposure data of the same period were obtained from the national air quality real-time release platform of China Environmental Monitoring Station. A generalized additive model based on quasi-Poisson distribution was used to analyze PM_2.5 exposure effect in each city, and the nonlinear mixing of moving average temperature, relative humidity and date was controlled by natural smooth spline function. Results: Among the included cities, southern cities accounted for 50.88% (29), and the number of female inpatients, hospitalization costs and hospitalization days accounted for 62.65%, 63.50% and 60.85% (42 735 cases, 567.78 million yuan and 1.14 million days, respectively). The proportion of hospitalized cases, hospitalization cost and length of stay in the age group of 40 to 64 years old were 59.15% (40 346 cases), 53.92% (482.15 million yuan) and 52.07% (0.98 million days), respectively. PM_2.5 level was positively correlated with the number of hospitalized cases with depression, hospitalization cost and length of stay. When the 3-day moving average of PM_2.5 exposure level increased by 10 μg/m³, the number of hospitalization cases increased by 0.64%. The attributed percentage (95%CI) of hospitalized cases, hospitalization costs and length of stay were 3.35% (0.57%-6.04%), 3.04% (0.52%-5.48%) and 3.07% (0.49%-5.56%), respectively. Subgroup analysis showed that the attributed percentage of hospitalization cases, hospitalization cost and length of stay to PM_2.5 exposure ranged from 3.97% to 4.68%, 4.04% to 4.33% and 4.13% to 4.30% in northern China, male and cold season, respectively. Conclusion: PM_2.5 exposure is associated with the increase of hospitalization cost and length of stay among Chinese urban population with depression.
Adult ; Air Pollutants/analysis* ; Air Pollution/analysis* ; China/epidemiology* ; Depression ; Dust/analysis* ; Female ; Hospitalization ; Humans ; Male ; Middle Aged ; Particulate Matter/analysis*

Monoacylglycerol lipase (MAGL) is a pivotal enzyme in the endocannabinoid system, which metabolizes 2-arachidonoylglycerol (2-AG) into the proinflammatory eicosanoid precursor arachidonic acid (AA). MAGL and other endogenous cannabinoid (EC) degrading enzymes are involved in the fibrogenic signaling pathways that induce hepatic stellate cell (HSC) activation and ECM accumulation during chronic liver disease. Our group recently developed an ¹⁸F-labeled MAGL inhibitor ([¹⁸F]MAGL-4-11) for PET imaging and demonstrated highly specific binding in vitro and in vivo. In this study, we determined [¹⁸F]MAGL-4-11 PET enabled imaging MAGL levels in the bile duct ligation (BDL) and carbon tetrachloride (CCl₄) models of liver cirrhosis; we also assessed the hepatic gene expression of the enzymes involved with EC system including MAGL, NAPE-PLD, FAAH and DAGL that as a function of disease severity in these models; [¹⁸F]MAGL-4-11 autoradiography was performed to assess tracer binding in frozen liver sections both in animal and human. [¹⁸F]MAGL-4-11 demonstrated reduced PET signals in early stages of fibrosis and further significantly decreased with disease progression compared with control mice. We confirmed MAGL and FAAH expression decreases with fibrosis severity, while its levels in normal liver tissue are high; in contrast, the EC synthetic enzymes NAPE-PLD and DAGL are enhanced in these different fibrosis models. In vitro autoradiography further supported that [¹⁸F]MAGL-4-11 bound specifically to MAGL in both animal and human fibrotic liver tissues. Our PET ligand [¹⁸F]MAGL-4-11 shows excellent sensitivity and specificity for MAGL visualization in vivo and accurately reflects the histological stages of liver fibrosis in preclinical models and human liver tissues.

BACKGROUND: Innovative coronavirus disease 2019 (COVID-19) vaccines, with elevated global manufacturing capacity, enhanced safety and efficacy, simplified dosing regimens, and distribution that is less cold chain-dependent, are still global imperatives for tackling the ongoing pandemic. A previous phase I trial indicated that the recombinant COVID-19 vaccine (V-01), which contains a fusion protein (IFN-PADRE-RBD-Fc dimer) as its antigen, is safe and well tolerated, capable of inducing rapid and robust immune responses, and warranted further testing in additional clinical trials. Herein, we aimed to assess the immunogenicity and safety of V-01, providing rationales of appropriate dose regimen for further efficacy study. METHODS: A randomized, double-blind, placebo-controlled phase II clinical trial was initiated at the Gaozhou Municipal Centre for Disease Control and Prevention (Guangdong, China) in March 2021. Both younger (n = 440; 18-59 years of age) and older (n = 440; ≥60 years of age) adult participants in this trial were sequentially recruited into two distinct groups: two-dose regimen group in which participants were randomized either to follow a 10 or 25 μg of V-01 or placebo given intramuscularly 21 days apart (allocation ratio, 3:3:1, n = 120, 120, 40 for each regimen, respectively), or one-dose regimen groups in which participants were randomized either to receive a single injection of 50 μg of V-01 or placebo (allocation ratio, 3:1, n = 120, 40, respectively). The primary immunogenicity endpoints were the geometric mean titers of neutralizing antibodies against live severe acute respiratory syndrome coronavirus 2, and specific binding antibodies to the receptor binding domain (RBD). The primary safety endpoint evaluation was the frequencies and percentages of overall adverse events (AEs) within 30 days after full immunization. RESULTS: V-01 provoked substantial immune responses in the two-dose group, achieving encouragingly high titers of neutralizing antibody and anti-RBD immunoglobulin, which peaked at day 35 (161.9 [95% confidence interval [CI]: 133.3-196.7] and 149.3 [95%CI: 123.9-179.9] in 10 and 25 μg V-01 group of younger adults, respectively; 111.6 [95%CI: 89.6-139.1] and 111.1 [95%CI: 89.2-138.4] in 10 and 25 μg V-01 group of older adults, respectively), and remained high at day 49 after a day-21 second dose; these levels significantly exceed those in convalescent serum from symptomatic COVID-19 patients (53.6, 95%CI: 31.3-91.7). Our preliminary data show that V-01 is safe and well tolerated, with reactogenicity predominantly being absent or mild in severity and only one vaccine-related grade 3 or worse AE being observed within 30 days. The older adult participants demonstrated a more favorable safety profile compared with those in the younger adult group: with AEs percentages of 19.2%, 25.8%, 17.5% in older adults vs. 34.2%, 23.3%, 26.7% in younger adults at the 10, 25 μg V-01 two-dose group, and 50 μg V-01 one-dose group, respectively. CONCLUSIONS: The vaccine candidate V-01 appears to be safe and immunogenic. The preliminary findings support the advancement of the two-dose, 10 μg V-01 regimen to a phase III trial for a large-scale population-based evaluation of safety and efficacy. TRIAL REGISTRATION http://www.chictr.org.cn/index.aspx (No. ChiCTR2100045107, http://www.chictr.org.cn/showproj.aspx?proj=124702).
Aged ; Antibodies, Viral ; COVID-19/therapy* ; COVID-19 Vaccines ; Double-Blind Method ; Humans ; Immunization, Passive ; Recombinant Fusion Proteins ; SARS-CoV-2

Objective::Dalbergiae Odoriferae Lignum is a rare traditional Chinese medicine material in China. However, there are many varieties of various sources and different qualities in the market at present. In order to further define the pharmacodynamic substance basis, electrospray time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) was used to rapidly analyze chemical constituents of methanol extract of Dalbergiae Odoriferae Lignum. Method::Chromatographic separation was performed on an UPLC RRHD SB-C₁₈(3.0 mm×100 mm, 1.8 μm)for gradient elution, with mixtures of acetonitrile and 0.1%formic acid-water as mobile phases at a flow rate of 0.3 mL·min^-1. The column temperature was maintained at 40 ℃. The data was collected in a negative ion mode with electro-spray ionization source(ESI). Result::According to molecular ion peaks and MS² mass spectrometry characteristic fragment ions, Mass Bank databases, as well as the mass spectrometry information of reference substances and relevant literatures, a total of 83 constituents were identified, including 18 flavones, 31 isoflavones, 10 neoflavonoids, 9 isoflavanones, 7 other flavonoids and 8 other components. Conclusion::UPLC-Q-TOF-MS/MS can quickly, accurately and comprehensively identify chemical constituents in methanol extract of Dalbergiae Odoriferae Lignum, and isoflavones, flavones, neoflavonoids and isoflavanones are the main chemical constituents, which laid a foundation for the basic research of medicinal substances of Dalbergiae Odoriferae Lignum, and provided theoretical basis and technical support for the improvement of quality standards of Dalbergiae Odoriferae Lignum.