[Research on epidemiological characteristics of pneumonia and correlative factors of length of hospitalization in the elderly aged 60 years and older in Ningbo].

Objective: To investigate the epidemiological characteristics of pneumonia and the related factors of the length of hospitalization of pneumonia in the elderly aged 60 years and older in Ningbo in 2019. Methods: Data on hospitalized cases of pneumonia in the elderly aged 60 years and older in Ningbo in 2019 were collected through the regional health information platform, and the population data of Ningbo in 2019 were obtained through the Zhejiang Provincial Bureau of Statistics. A descriptive epidemiological analysis was conducted on hospitalized cases of pneumonia in the elderly population, and factors related to the length of hospitalization were explored. Results: A total of 15 956 hospitalized cases of pneumonia aged 60 years and older were reported in Ningbo in 2019, and the incidence of pneumonia requiring hospitalization was 1.02% (15 956/1 571 431). The incidence was 1.13% (8 613/760 357) in males and 0.83% (6 759/811 074) in females, and the ratio of male to female cases was 1.27∶1. The highest incidence was found in the ≥80 age group (2.52%), and the lowest incidence was found in the 60-69 age group (0.58%). March, February, and January were the peak period of pneumonia hospitalization. The main types of pneumonia diagnosed were not specified (65.12%), followed by bacterial pneumonia (34.60%). The M(Q1, Q3) of hospitalized patients with pneumonia was 9 (7, 13) days. The results of multivariate logistic regression analysis showed that gender (female: OR=0.911, 95%CI: 0.849-0.978) and older age (70-79 years old: OR=1.211, 95%CI: 1.111-1.321; ≥80 years old group: OR=1.486, 95%CI: 1.365-1.617), settlement method (self-payment: OR=0.567, 95%CI: 0.464-0.691), higher level of hospitals (Grade Ⅱ: OR=1.902,95%CI:1.723-2.100; Grade Ⅲ: OR=1.546,95%CI:1.407-1.698) were associated with the length of hospitalization for pneumonia in people aged 60 years and older in Ningbo. Conclusions: Hospitalization with pneumonia in people aged 60 years and older was high in winter and spring, men and older adults were in high-risk groups in Ningbo in 2019. Gender, age, billing method, and level of hospitals may be related factors to the length of hospitalization for pneumonia.

[Epidemiological characteristics and spatiotemporal distribution of schizophrenia in Ningbo, 2018-2022].

Objective: To explore the temporal and spatial distribution characteristics of reported incidence of schizophrenia in Ningbo from 2018 to 2022 and to provide a scientific basis for rational allocation of mental health resources and comprehensive prevention and treatment of schizophrenia. Methods: The reported incidence data of schizophrenia from 2018 to 2022 were collected from Ningbo's mental health information management system, and the reported incidence was calculated by township. The spatial correlation analysis and the spatiotemporal scan analysis were used to study the spatiotemporal distribution of schizophrenia. Results: The reported incidence of schizophrenia decreased from 2018 to 2022, with 4 133 new cases reported, and the annual average reported incidence was 9.76/100 000. Global and local spatial autocorrelation analysis showed positive spatial correlations and hot spots in 2018-2020. The space-time scan analysis showed an incidence cluster in Dongqiao Town, Haishu District, during 2018-2019. The RR was 2.46, and the log-likelihood ratio was 256.89. Conclusions: The reported incidence of schizophrenia in Ningbo has obvious temporal and spatial aggregation, and the high incidence area explored can provide clues for further research on the correlation between environmental factors and the incidence of schizophrenia and has certain guiding significance for the rational allocation of mental health resources in Ningbo.

Chemical and Cellular Formation of Reactive Oxygen Species from Secondary Organic Aerosols in Epithelial Lining Fluid.

INTRODUCTION: Oxidative stress mediated by reactive oxygen species (ROS) is a key process for adverse aerosol health effects. Secondary organic aerosols (SOA) account for a major fraction of particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5). PM2.5 inhalation and deposition into the respiratory tract causes the formation of ROS by chemical reactions and phagocytosis of macrophages in the epithelial lining fluid (ELF), but their relative contributions are not well quantified and their link to oxidative stress remains uncertain. The specific aims of this project were (1) elucidating the chemical mechanism and quantifying the formation kinetics of ROS in the ELF by SOA; (2) quantifying the relative importance of ROS formation by chemical reactions and macrophages in the ELF. METHODS: SOA particles were generated using reaction chambers from oxidation of various precursors including isoprene, terpenes, and aromatic compounds with or without nitrogen oxides (NOx). We collected size-segregated PM at two highway sites in Anaheim, CA, and Long Beach, CA, and at an urban site in Irvine, CA, during two wildfire events. The collected particles were extracted into water or surrogate ELF that contained lung antioxidants. ROS generation was quantified using electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping technique. PM oxidative potential (OP) was also quantified using the dithiothreitol assay. In addition, kinetic modeling was applied for analysis and interpretation of experimental data. Finally, we quantified cellular superoxide release by RAW264.7 macrophage cells upon exposure to quinones and isoprene SOA using a chemiluminescence assay as calibrated with an EPR spin-probing technique. We also applied cellular imaging techniques to study the cellular mechanism of superoxide release and oxidative damage on cell membranes. RESULTS: Superoxide radicals (·O2-) were formed from aqueous reactions of biogenic SOA generated by hydroxy radical (·OH) photooxidation of isoprene, ß-pinene, α-terpineol, and d-limonene. The temporal evolution of ·OH and ·O2- formation was elucidated by kinetic modeling with a cascade of aqueous reactions, including the decomposition of organic hydroperoxides (ROOH), ·OH oxidation of primary or secondary alcohols, and unimolecular decomposition of α-hydroxyperoxyl radicals. Relative yields of various types of ROS reflected the relative abundance of ROOH and alcohols contained in SOA, which generated under high NOx conditions, exhibited lower ROS yields. ROS formation by SOA was also affected by pH. Isoprene SOA had higher ·OH and organic radical yields at neutral than at acidic pH. At low pH ·O2- was the dominant species generated by all types of SOA. At neutral pH, α-terpineol SOA exhibited a substantial yield of carbon-centered organic radicals (R·), while no radical formation was observed by aromatic SOA.Organic radicals in the ELF were formed by mixtures of Fe2+ and SOA generated from photooxidation of isoprene, α-terpineol, and toluene. The molar yields of organic radicals by SOA were 5-10 times higher in ELF than in water. Fe2+ enhanced organic radical yields by a factor of 20-80. Ascorbate mediated redox cycling of iron ions and sustained organic peroxide decomposition, as supported by kinetic modeling reproducing time- and concentration-dependence of organic radical formation, as well as by additional experiments observing the formation of Fe2+ and ascorbate radicals in mixtures of ascorbate and Fe3+. ·OH and superoxide were found to be efficiently scavenged by antioxidants.Wildfire PM mainly generated ·OH and R· with minor contributions from superoxide and oxygen-centered organic radicals (RO·). PM OP was high in wildfire PM, exhibiting very weak correlation with radical forms of ROS. These results were in stark contrast with PM collected at highway and urban sites, which generated much higher amounts of radicals dominated by ·OH radicals that correlated well with OP. By combining field measurements of size-segregated chemical composition, a human respiratory tract model, and kinetic modeling, we quantified production rates and concentrations of different types of ROS in different regions of the ELF by considering particle-size-dependent respiratory deposition. While hydrogen peroxide (H2O2) and ·O2- production were governed by Fe and Cu ions, ·OH radicals were mainly generated by organic compounds and Fenton-like reactions of metal ions. We obtained mixed results for correlations between PM OP and ROS formation, providing rationale and limitations of the use of oxidative potential as an indicator for PM toxicity in epidemiological and toxicological studies.Quinones and isoprene SOA activated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in macrophages, releasing massive amounts of superoxide via respiratory burst and overwhelming the superoxide formation by aqueous chemical reactions in the ELF. The threshold dose for macrophage activation was much smaller for quinones compared with isoprene SOA. The released ROS caused lipid peroxidation to increase cell membrane fluidity, inducing oxidative damage and stress. Further increases of doses led to the activation of antioxidant response elements, reducing the net cellular superoxide production. At very high doses and long exposure times, chemical production became comparably important or dominant if the escalation of oxidative stress led to cell death. CONCLUSIONS: The mechanistic understandings and quantitative information on ROS generation by SOA particles provided a basis for further elucidation of adverse aerosol health effects and oxidative stress by PM2.5. For a comprehensive assessment of PM toxicity and health effects via oxidative stress, it is important to consider both chemical reactions and cellular processes for the formation of ROS in the ELF. Chemical composition of PM strongly influences ROS formation; further investigations are required to study ROS formation from various PM sources. Such research will provide critical information to environmental agencies and policymakers for the development of air quality policy and regulation.

[One case of extensive high-pressure injection injury of hand caused by polyurethane material].

This article reports a patient with extensive high-pressure injection injury of the hand caused by mistaken injection of polyurethane material into the index finger, who was diagnosed and treated in the Department of Orthopedics of Huzhou Central Hospital in 2019. Both the digital artery and digital nerve were involved, and the polyurethane involved the right palm along the flexor tendon sheath of the index finger and wrist. Due to the lack of X-ray development, the scope of the first debridement was small, and the blood supply to the fingertip was poor. Finally, the patient's right index finger was amputated due to infection and necrosis. MR or B-ultrasound should be perfected before operation to clarify the extent of polyurethane involvement. The initial thorough debridement or multiple debridements are necessary to improve the prognosis. If the blood supply of the fingers is poor, the blood supply can be reconstructed by skin flap transplantation.

[Bilateral posterior shoulder dislocation with associated reverse Hill-Sachs lesions after electrical injury].

After workers suffer electric shock, the ankylosis and contraction of muscle groups around the shoulder joint are more likely to lead to posterior dislocation and fracture, of which 80% are complicated with reverse Hill-Sachs injury of humeral head. This paper reports a case of bilateral posterior dislocation of shoulder joint combined with Hill-Sachs injury caused by electric shock in the Department of Orthopedics, Affiliated Huzhou Hospital, Zhejiang University School of Medicine in August 2020. The diagnosis of left posterior shoulder dislocation was clear, and the diagnosis of right posterior shoulder dislocation was missed. The patient successfully reconstructed the stability of the shoulder joint by actively performing shoulder arthroscopic surgery to repair the joint capsule. After 6 months of follow-up, there was no further dislocation and the function was good.

[Effectiveness of precise prevention and control strategies of dynamic zero COVID-19 in Ningbo, Zhejiang province].

Objective: To evaluate effectiveness of the precise prevention and control strategies of dynamic zero COVID-19 in Ningbo, Zhejiang province. Methods: Based on the incidence data of COVID-19 and case epidemiological survey report in Ningbo in December 2021, the incidence curve of COVID-19 was generated and a dynamics model was developed to estimate the case number of under different intervention measures. The basic reproduction number (R0) and real-time reproduction number (Rt) were calculated to evaluate intervention effect. Results: A total of 74 cases of COVID-19 had been confirmed in Ningbo as of 17 December, 2021. The R0 was estimated to be 4.3. With the strengthening of prevention and control measures, the Rt showed a gradual downward trend, dropping to below 1.0 on December 11 and 0.4 on December 14. The model fitting results showed that the actual case number was close to the estimated case number (76 cases) when the effectiveness of intervention was 90%. The number of cases decreased by 98.4% compared with that if no intervention was taken. Conclusion: The precise prevention and control strategies of dynamic zero COVID-19 have obvious effect, which can facilitate the rapid control of COVID-19 epidemic in Ningbo.

[The mediating role of anxiety and depression for family members of ICU patients in perceived social support and fatigue].

To analyze the mediating role of anxiety and depression in perceived social support and fatigue in ICU patients' families, and to provide a theoretical evidence for alleviating their fatigue status. A total of 223 family members of ICU patients who received treatment at the Affiliated Hospital of Jiangnan University from October 2020 to April 2021 were selected as the study subjects. The general data questionnaire, perceived social support scale (PSSS), generalized anxiety disorder scale (GAD-7), patient health questionnaire (PHQ-9) and fatigue assessment instrument (FAI) were used to conduct a survey. Among 223 family members of ICU patients, 155(69.51%) had fatigue problems. There were statistically significant differences in total fatigue scores of ICU patients' family members in terms of gender, age, education level, relationship with patients, residence, payment method and per capita monthly income (P<0.05). Anxiety, depression and fatigue were negatively correlated with perceived social support (r are -0.353, -0.276 and -0.416, respectively, all P<0.01). Depression and fatigue were positively correlated with anxiety (r are 0.808 and 0.703, respectively, all P<0.01), and fatigue was also positively correlated with depression (r= 0.665, P<0.01). Anxiety and depression had a partial mediating effect on perceived social support and fatigue, and the total indirect effect size was 52.64%. Comprehensive intervention on the level of social support, anxiety and depression is helpful to improve the fatigue status of ICU patients' family members.

[Seroepidemiology of pertussis in healthy population in Ningbo, 2019].

Objective: To understand the seroepidemiological characteristics of pertussis in healthy population in Ningbo, and estimate the overall incidence of pertussis. Methods: A cross-sectional survey method was used in this study. A total of 1 206 healthy residents in 9 age groups were stratified randomly selected from 3 counties of Ningbo. Serum samples were collected from the subjects, and the pertussis toxin immunoglobulin G antibody (PT-IgG) levels were measured quantitatively by enzyme-linked immunosorbent assay (ELISA). Results: The mean PT-IgG seropositive rate in the subjects was 0.91% (95%CI:0.45%-1.63%) with a geometric mean titer (GMT) of 3.10 (95%CI:2.86-3.36) IU/ml. The seropositive rates ranged from 0.00% to 1.68%, and the GMTs ranged from 2.08 IU/ml to 5.28 IU/ml in 9 age groups. The incidence rate of pertussis was estimated to be 4 572.81 per 100 000 in age group ≥5 years (95%CI:1 807.30 per 100 000-9 348.12 per 100 000), and the peak of estimated incidence rates were found in age group 5- years (9 301.62 per 100 000, 95%CI:1 121.77 per 100 000-33 154.68 per 100 000) and age group ≥50 years old (8 967.02 per 100 000, 95%CI: 1 059.45 per 100 000-31 845.94 per 100 000). Conclusions: The actual incidence of pertussis was high in Ningbo in 2019. As a result of waning immunity after vaccination, pertussis can occur in adolescents and adults. The pertussis surveillance should be strengthened and the pertussis vaccination strategy should be improved.

Research Progress on Pathological Fibrosis of Sinoatrial Node.

ABSTRACT: Human heart rhythm is mainly regulated and controlled by the sinoatrial node. Fibrosis plays an important regulating role in adjusting the structural and functional integrity of the sinoatrial node pacemaker complex. In physiological state, the fibrosis degree of sinoatrial node is negatively correlated with heart rate, positively correlated with age and heart size, and can maintain a relatively stable heart rate. Pathological fibrosis of sinoatrial node can induce various types of arrhythmias which can result in sudden death. Determination of the mechanisms related to sinoatrial node pathological fibrosis could provide a target for clinical treatment of sinoatrial node fibrosis and diagnosis basis for forensic pathologists. This paper reviews the main mechanism of sinoatrial node pathological fibrosis, including abnormal activation of cardiac fibroblast cells in sinoatrial node, hyperplasia of epicardial adipose tissue, calcium clock disorder, artery stenosis, etc., introduces the test methods, diagnostic criteria as well as its role in sudden cardiac death and discusses the potential application, to provide reference for relevant research and application.

[Epidemiological and etiological characteristics of hand, foot and mouth disease among children aged 5 years and younger in Ningbo (2016 to 2019)].

OBJECTIVE: To describe the epidemiological and etiological characteristics of hand, foot and mouth disease (HFMD) among children aged 5 years and younger in Ningbo after the access of entero-virus-A71 vaccine (2016 to 2019). METHODS: A retrospective cohort study were performed in children aged 5 years and younger in Ningbo from 2016 to 2019. Data for incidence of HFMD was collected from the National Notifiable Disease Surveillance Reporting System and the Electronic Medical Records (EMRs) System, while the demographic information was derived from the Immunization Information System. Speci-mens were detected by real-time fluorescence quantitative PCR and the Wilson method was used to estimate the incidence rate and 95% confidence interval. RESULTS: From 2016 to 2019, a total of 1 044 800 residential children were observed in this population-based cohort. In the study, 102 471 cases of HFMD were diagnosed in 2 651 081 person-years, revealing an overall incidence density of 3 865.25/100 000 person-years. There was no significant decline in the number of the cases after the vaccine was available. The number of the patients of hand foot mouth disease during the four years was 93 421, of whom 84 875 (90.85%) had only one incident record, while 8 946 (9.15%) had 2 or more cases in this period; there were 69 771 (66.06%) patients who only needed to see a doctor once for each disease, 19.92% of the patients needed to be treated twice, and 14 801 (14.02%) patients needed to go to the hospital or clinic three times or more. The incidence of HFMD showed obvious seasonality and periodicity, which mainly concentrated in April to July each year, and the epidemic cycle was 2 years; most of the cases were 1 to 3-year old children, with more cases in male. The incidence density varied across the region, with the highest density observed in Ninghai (4 524.76/100 000 person-years), followed by Xiangshan (3 984.22/100 000 person-years). In 3 748 library-conformed cases, 2 834(75.61%) were detected positive, among which enterovirus-A71, Cox-A16 and other enteroviruses accounted for 9.03%, 31.55% and 59.42%, respectively. During the study period, the cumulative coverage of enterovirus-A71 vaccine increased year by year, with the proportion of enterovirus-A71 and severe cases both gradually decreasing. CONCLUSION: The current status of hand, foot and mouth disease in Ningbo is still serious. Children under 3-year old (especially male children aged 1 year) were the key population for prevention and control. Vaccination might lead to changes in major pathogenic virus type, of which more attention should be paid to the potential impact on disease surveillance, prevention and control.

[Epidemiological study of infantile epilepsy incidence density among infants under 36 months of age in Ningbo City from 2015 to 2019].

OBJECTIVE: To describe the distribution and trend of infantile epilepsy among infants under 36 months in Ningbo, Zhejiang Province. METHODS: Using the birth cohort design, we retrospectively collected the local born infants in Ningbo national health information platform from 2015 to 2019, and took the first visit of epilepsy in the electronic medical record of the platform as the new case. The incidence density and 95% confidence interval (CI) of epilepsy were estimated by Poisson distribution. RESULTS: From 2015 to 2019, a total of 294 900 children were born in Ningbo, with male accounting for 51.92%. The total person-years of observation were 595 300, while the median follow-up person-years was 2.31 [interquartile range (IQR): 1.90]. There were 575 new onset epilepsy patients during the whole observation period. The total number of visits was 2 599, with an average of 4.52. The total incidence density was 96.59/100 000 person-years (95%CI: 88.85-104.82). The median age of onset was 13 months (IQR: 15), 0-12 months old infants had the highest incidence density (102.18/100 000 person-years), 25-36 months old infants had the lowest incidence density (89.68/100 000 person-years), and the difference was not statistically significant (P>0.05). The incidence density of male was 97.58/100 000 person-years, female was 95.53/100 000 person-years, and the difference was not statistically significant (P>0.05). Fenghua was the highest (130.54/100 000 person-years, 95%CI: 94.47-175.83) and Ninghai was the lowest (66.44/100 000 person-years, 95%CI: 47.02-91. 19), with significant difference (P < 0.05). There was no significant difference in the incidence density in different birth years (P>0.05). There was significant difference in the incidence density between 0-12 months old infants in different calendar years (Ptrend < 0.05). In this age group, the incidence density was the lowest in 2015 (69.41/100 000 person-years, 95%CI: 41.79-108.39), and the highest in 2019 (225.61/100 000 person-years, 95%CI: 186.10-271.03). There was no significant difference in the incidence density between 13-24 and 25-36 months old infants in different calendar years (P>0.05). CONCLUSION: The incidence density of epilepsy in 0-36 months old infants in Ningbo City from 2015 to 2019 was low as a whole, and there was no difference in age group, gender, and year of birth. The incidence density of 0-12 months old infants increased with the year.

[The mechanism study of ouabain in inhibiting the growth of hepatocellular carcinoma cells by inhibiting the laser kinase signaling pathway].

Objective: To investigate the effect of Na(+)/K(+)-ATPase inhibitor ouabain on the proliferation and division of liver cancer HepG2 cells, and to explore the anticancer mechanism. Methods: HepG2 cells were exposed with different concentrations of ouabain (0.1, 1, 10 µmol/L) for 24 h, the proliferation ability was appraised using CCK-8, and the HepG2 cells was as a control group. The status of chromosome separation was detected with cell immunofluorescence (ICC) coupled to confocal microscope. The expression levels of AURKA, mTOR, p-mTOR, ERK and p-ERK protein were analyzed using western blot. Results: After treating with 0.1, 1 and 10 µmol/L of ouabain for 24 h, the inhibitory rate of cells were (23.5±4.57)%, (49.80±5.32)%, and (72.10±5.62)%, respectively. Ouabain could significantly inhibit the proliferation of HepG2, and presented in a dose-dependent manner(F=32.8, P<0.05). The ICC results showed that the chromosome separation disorders occurred in HepG2 cells treated with 1 µmol/L for 24 h, and the spindle diameter of HepG2 cells with ouabain treatment was decreased significantly compared with the control group(t=9.58, P<0.05). The results of western blot showed that the expression levels of AURKA, p-mTOR and p-ERK expressions in HepG2 cells treated with 1 µmol/L of ouabain were significantly decreased compared with the control group(F=16.26, 8.32, 33.59, P<0.05). Ouabain inhibited the growth of hepatocellular carcinoma cells in nude mice(F=370.20, P<0.05). Conclusion: Ouabain can induce chromosome division disorder and inhibit the proliferation in liver cancer HepG2 cells by inhibiting AURKA signaling pathway.

A case of coronavirus HKU1 encephalitis.

Coronaviruses are widespread in nature and can infect several different species, causing mainly respiratory and enteric diseases. The respiratory involvement of human coronaviruses has been clearly established since the 1960s. Three of the six coronaviruses that infect humans have been shown to be neuroinvasive and neurotropic in humans: HCoV-229E, HCoV-OC43, and SARS-CoV. No reports exist on the detection of HCoV-HKU1 in the human central nervous system (CNS). We report a case of a patient, in whose cerebrospinal fluid (CSF) was detected Coronavirus NL63/HKU1. Coronavirus HKU1 was detected in the sputum. With effective antiviral therapy and the use of glucocorticoids, the patient was eventually discharged from the hospital. This study might help understand more about coronavirus and improve the awareness of pathogen detection in patients with coronavirus encephalitis. Keywords: coronavirus HKU1; encephalitis.

[Investigation of a cluster epidemic of COVID-19 in Ningbo].

Objective: To investigate a cluster epidemic of COVID-19 after a mass gathering activity in Ningbo of Zhejiang province and analyze the transmission chain and status of infection cases of different generations. Methods: The tracking of all the close contacts of the first COVID-19 case and epidemiological investigation were conducted on January 29, 2020 after a cluster epidemic of COVID-19 related with a Buddhism rally on January 19 (the 1.19 rally) in Ningbo occurred. The swabs of nose/throat of the cases and close contacts were collected and tested for nucleic acids by real-time fluorescence quantitative RT-PCR. Results: From January 26 to February 20, 2020, a total of 67 COVID-19 cases and 15 asymptomatic infection cases related with the 1.19 rally were reported in Ningbo. The initial case was the infection source who infected 29 second generation cases and 4 asymptomatic infection cases, in whom 23 second generation cases and 3 asymptomatic infection cases once took bus with the initial case, the attack rate was 33.82% (23/68) and the infection rate was 38.24% (26/68). The risks of suffering from COVID-19 and being infected were 28.91 times and 26.01 times higher in rally participants taking bus with initial case compared with those taking no bus with initial case. In this epidemic, 37 third+generation cases and 11 related asymptomatic infection cases occurred, the attack rate was 2.88% (37/1 283) and the infection rate was 4.76% (48/1 008). The main transmission routes included vehicle sharing and family transmission. Conclusion: It was a cluster epidemic of COVID-19 caused by a super spreader in a massive rally. The epidemic has been under effective control.

[Study on transmission dynamic of 15 clusters of COVID-2019 cases in Ningbo].

Objective: To describe the basic characteristics of clusters of coronavirus diseases 2019 (COVID-19) cases in Ningbo, Zhejiang province, and evaluate the generation time (Tg) and basic reproduction number (R(0)) of COVID-19. Methods: The basic information and onset times of the clusters of COVID-19 cases in Ningbo were investigated, the inter-generational interval of the cases were fitted by using gamma distribution, and the R(0) was calculated based on the SEIR model. Results: In the 15 clusters of COVID-19 cases, a total of 52 confirmed cases, 5 cases of nucleic acid-positive asymptomatic cases. The cases occurred from January 23 to February 4, the cases were mainly women. The incubation period was (6.11±3.38) days, and the median was 5 days. The Tg was (6.93±3.70) days. There were no significant differences in Tg between age group<60 years and age group 60 years and above, and between men and women (P=0.551). According to the Tg calculated in this paper, the R(0) of COVID-19 in Ningbo was 3.06 (95%CI: 2.64- 3.51); according to the reported case transmission interval of 7.5 days in the literature, the R(0) was 3.32 (95%CI: 2.51-9.38). Conclusion: There is no age and gender specific differences in the Tg of clusters of COVID-19 cases in Ningbo, and COVID-19 has high infectivity and spreading power in early phase.

[Effect of KIR/HLA receptor-ligand mode on prognosis of single unrelated cord blood transplantation in patients with hematological malignancies].

Objective: To explore the impact of the natural killer cell immunoglobulin-like receptor/human leukocyte antigen (KIR/HLA) receptor-ligand model in single unrelated cord blood transplantation (sUCBT) . Methods: Between July 2012 and June 2018, 270 patients with malignant hematologic diseases receiving single-unit UCBT were divided into two groups. Group 1 (n=174) patients lacked a C-ligand for inhibitory KIR on UCB NK cells (patients homozygous C1/C1 or C2/C2) . Group 2 (n=96) patients expressed both C ligands for inhibitory KIR in the receptor (patients heterozygous C1/C2) . Results: A total of 270 patients (146 males, 124 females) with a median age of 13 years (1-62) were included in this retrospective study. All patients received a myeloablative conditioning regimen (without ATG) . The ratio of neutrophil engraftment for group 1 and 2 were both 98.9%, the median time of neutrophil engraftment for group 1 and 2 was 16 (10-41) days vs 17 (11-33) days (P=0.705) . The ratio of platelet engraftment was 88.5% for group 1 and 87.5% for group 2, the median time of platelet engraftment was 35 (11-113) days vs 38.5 (13-96) days (P=0.317) . The cumulative incidence of Ⅱ-Ⅳ acute GVHD in 100 days was 38.7% (95%CI 31.4%-45.9%) for group 1 and 50.0% (95%CI 39.6%-59.6%) for group 2 (P=0.075) , but multivariate analysis showed that HLA-C ligand absence was an independent protective factor for Ⅱ-Ⅳ acute GVHD after transplantation (P=0.036) . Patients in absence of a C-ligand for inhibitory KIRs (Group 1) showed a lower relapse rate than patients with both C-ligands (group 2) : 17.7% (95%CI 11.7%-24.9%) vs 22.7% (95%CI 4.4%-32.2%) after 3 years (P=0.288) . The median follow-up time was 742 (335-2 512) days. The 3-year OS was 72.1% for group 1 and 60.5% for group 2 (P=0.079) . There was no statistically significant difference between the two groups in 3-year disease-free survival [64.9% (95%CI 56.2%-72.3%) vs 55.4% (95%CI 44.4%-65.0%) (χ(2)=3.027, P=0.082) ]. Non-relapse mortality for group 1 was 12.1% (95%CI 7.7%-17.4%) and for group 2 was 16.7% (95%CI 10.0%-24.8%) (P=0.328) . Conclusion: Patients lacking a KIR-ligand of HLA group C1 or C2 had a lower incidence of grades Ⅱ-Ⅳ acute GVHD after sUCBT.

[Comparison on efficacy and safety of different bridging anticoagulation therapies in patients undergoing mechanical heart valve replacement surgery].

Objective: To evaluate the efficacy and safety of different bridging anticoagulant therapies in patients undergoing mechanical heart valve replacement (MHVR) surgery. Methods: Consecutive patients undergoing MHVR surgery from January 2018 to December 2018 in First Hospital of Lanzhou University were prospectively enrolled in this study. Patients were divided into unfractionated heparin (UFH) group and low molecular weight heparin (LMWH) group according to the postoperative bridging anticoagulation methods. Preoperative clinical data and postoperative related time and cost parameters, including drainage time, duration of stay in intensive care unit (ICU), postoperative time (interval from end of operation to discharge) and INR stabilization time (interval from start of bridge anticoagulation to INR value reaching the standard for 2 consecutive days) of all enrolled patients were collected, and all patients were followed up for 4 weeks and thromboembolic or bleeding events were analyzed. Multivariate logistic regression was used to determine the independent prognostic factors of thromboembolic or bleeding events after MHVR receiving various bridging anticoagulant therapies. Results: A total of 217 patients were included in the study, including 120 patients in the UFH group and 97 patients in the LMWH group. Stroke occurred in two patients in the UFH group, while no stroke event occurred in the LMWH group. The incidence of bleeding events was significantly higher (9.28%(9/97) vs. 1.67%(2/120), P=0.02), while the drainage time, duration of stay in ICU, postoperative time, INR stabilization time were all significantly shorter in LMWH group than in UFH group (all P<0.05). Multivariate logistic regression analysis showed that bridging anticoagulation therapies (OR=0.18, 95%CI 0.04-0.86, P=0.03), fibrinogen level (OR=1.99, 95%CI 1.16-3.41, P=0.01) and creatinine level (OR=1.05, 95%CI 1.01-1.08, P=0.04) were independent prognostic factors for bleeding events. Conclusion: LMWH use is associated with increased risk of bleeding events, but can significantly reduce the drainage time, duration of stay in ICU, postoperative time, INR stabilization time in patients post MHVR surgery.