Objective:To explore the effect of heterozygous deletion of histone methyltransferase Kmt2c gene on the hematological system of mice.Methods:CRISPR/Cas9 technology was used to construct mice model of Kmt2c heterozygous deletion(Kmt2c+/-)and the changes of whole blood cell count in mice were continuously monitored by blood routine test.The clonal expansion ability of bone marrow cells was explored by colony formation assay in vitro and the proportion of primitive hematopoietic cells,including long-term hematopoietic stem cell(LT-HSC),short-term hematopoietic stem cell(ST-HSC),and multipotent progenitor cell in mutant mice was analyzed by flow cytometry.Results:Kmt2c+/-mice model was successfully constructed,and the mRNA expression level of Kmt2c was 28％of that of C57BL/6J mice.The colony formation ability of bone marrow cells of Kmt2c+/-mice in vitro increased with the passage times,and the colony number in the fourth generation was significantly higher than that of control group(P＜0.05).The proportions of LT-HSC and ST-HSC in the primitive hematopoietic cell population of Kmt2c+/-mice was 19.6％±3.3％and 28.9％±4.9％,respectively,which showed an increasing trend compared with 16.9％±2.6％and 18.9％±2.5％in control group,but the difference was not statistically significant(P＞0.05).The white blood cell count of Kmt2c+/-mice gradually increased after 12 weeks of monitoring and reached(9.8±1.0)×109/L at the 14th week,which was significantly higher than(7.3±1.4)× 109/L of control group(P＜0.05).Conclusion:The bone marrow cells of Kmt2c+/-mice have potential of clonal expansion.

Objective:To explore the influence of environment temperature on the incidence of testicular torsion.Methods:We collected the clinical data on 172 cases of testicular torsion diagnosed in the Second Hospital of Hebei Medical University from De-cember 2013 to December 2020.According to the local environment temperature on the day of onset,we divided the patients into groups A(below 0℃),B(0-10℃),C(10-20℃)and D(above 20℃),and compared the incidence rates of testicular torsion among the four groups,followed by correlation analysis.Results:The incidence rate of testicular torsion was 12.8％(n=22)in group A,35.5％(n=61)in B,34.9％(n=60)in C and 16.9％(n=29)in D,the highest at 0-10℃ in group B,with sta-tistically significant difference among the four groups(x2=29.07,P＜0.001).Spearman correlation analysis indicated that the inci-dence of testicular torsion was negatively correlated with the environment temperature(r=-0.261,P＜0.01),with no statistically significant difference among different seasons(x2=5.349,P＞0.05),but higher in autumn and winter than in the other two sea-sons.Conclusion:The incidence of testicular torsion is negatively correlated with the environment temperature,elevated when the temperature decreases,but has no statistically significant difference among different seasons,though relatively higher in autumn and winter.

Objective:To investigate the clinical and genetic characteristics of a male carrier of exceptional complex chromo-some rearrangement(CCR)and the outcome of preimplantation genetic testing for chromosomal structural rearrangement(PGT-SR).Methods:Using the modified high resolution G banding technique and whole-genome low-coverage sequencing(WGLCS),we analyzed the cellular karyotype and molecular karyotype of a male carrier of CCR,performed an analysis of the single-sperm chromosome copy number and conducted PGT-SR for the patient by next-generation sequencing(NGS).In addition,we reviewed the literature on repor-ted male carriers of CCRs and summarized their normal/balanced sperm ratios and PGT-SR outcomes.Results:The karyotype of the patient was 46,XY,der(5)inv(5)(q14.3q23.2)t(5;14;11)(q23.2;q31.1;q21),der(11)t(5;14;11);der(14)t(5;14;11),with the translocation breakpoints located in the intergenic region.Single-sperm sequencing revealed 20.0%(7/35)of normal haploids in the male's spermatozoa,and the results PGT-SR showed a proportion of 25.0%(4/16)of normal/balanced embryos.After thawing and transferring of 2 euploid blastocysts,a healthy male infant was successfully delivered.Conclusion:The proportion of normal hap-loids in the spermatozoa of male CCR carriers may be higher than theoretically predicted,and PGT-SR can effectively improve the preg-nancy outcome in male CCR carriers and provide valuable data for genetic counseling.

Objective:To investigate the clinical application value of liquid wound dressing in circumcision.Methods:This retrospective study included 200 cases of redundant prepuce or phimosis undergoing circumcision in the Affiliated Hospital of Nanjing University of Chinese Medicine between August 2021 and December 2022.We divided the patients into two groups of an equal number to receive wound care with liquid wound dressing(the observation group)and iodine gauze dressing(the control group),respectively.We compared the operation time,postoperative bleeding,edema,infection,incision exudation and scarring,and pain scores during dressing change at 4,24 and 72 hours after surgery.Results:No statistically significant differences were observed between the ob-servation and control groups in the operation time([16.22±3.15]vs[17.01±3.37]min,P＞0.05)or postoperative bleeding(12 vs 14 cases,P＞0.05).The patients in the observation group,compared with the controls,showed significantly lower incidences of postoperative edema(9 vs 23 cases),infection(6 vs 17 cases),incision exudation(7 vs 21 cases)and scarring(5 vs 14 cases),and lower pain scores during dressing change at 4 hours(6.71±1.02vs7.04±0.92),24 hours(5.38±1.45 vs 5.87±1.35)and 72 hours after surgery(3.65±1.53 vs 4.26±1.63)(all P＜0.05).Conclusion:For postoperative wound care of the patients undergoing circumcision,liquid wound dressing can evidently reduce postoperative pain,incision bleeding,edema,infection and scarring,and therefore deserves clinical promotion.

The main components and working principle of the negative pressure isolation treatment equipment were described,and the classification and application scopes of the negative pressure isolation treatment equipment from foreign countries and China were reviewed.The structure,key technical parameters and characteristics of different types of negative pressure isolation treatment equipment were analyzed under different conditions.The problems of the negative pressure isolation treatment equipment were analyzed,and it's pointed out it would be enhanced in component simplification,comfort,intelligence and multifunctionality.[Chinese Medical Equipment Journal,2024,45(2):97-104]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective To assess the value of acute gastrointestinal injury(AGI)and intestinal fatty acid-binding protein(I-FABP)in the prognosis of liver cirrhotic patients with sepsis.Methods Clinical data of 84 liver cirrhosis patients with sepsis who were admitted to the intensive care unit(ICU)of a hospital from September 2020 to March 2023 were analyzed retrospectively,and 41 patients with decompensated liver cirrhosis during the same period were selected as the control group.Serum I-FABP level in patients was determined with enzyme-linked immunosorbent assay(ELISA).Scores of the model of end-stage liver disease(MELD)and sequential organ failure assessment(SOFA)were calculated.AGI was evaluated based on medical records.30-day and 90-day survival was observed.Correlation among variables was analyzed by Spearman correlation.Risk factors for death in patients with liver cir-rhosis and sepsis was determined by multivariate Cox regression analysis.The optimal cut-off value was determined by receiver operating characteristic(ROC)curve,and the diagnostic efficacy was compared through the area under the ROC curve(AUC).Results Both AGI grading and I-FABP level in liver cirrhosis patients with sepsis were higher than those in the control group(both P＜0.05).I-FABP level was correlated with procalcitonin(PCT),MELD,and SOFA scores in patients with liver cirrhosis and sepsis(all P＜0.05).AGI grading was positively cor-related with SOFA score(P=0.038).The 30-day and 90-day mortality of patients in the liver cirrhosis with sepsis group were 25.0％(n=21)and 35.7％(n=30),respectively.Multivariate Cox regression analysis showed that baseline I-FABP and SOFA scores were independently correlated with 30-day and 90-day survival,and the I-FABP quartile showed good prognostic differentiation efficacy.ROC curve showed that I-FABP could significantly improve the predictive effect of SOFA score on the prognosis of patients.Conclusion AGI grading and I-FABP level in liver cirrhosis patients with sepsis are elevated significantly.Serum I-FABP is associated with the prognosis of patient and can improve the predictive efficacy of SOFA score for survival.

Tranexamic acid is widely used in joint orthopedic surgery.At the same time,it has high safety and few adverse drug reactions.It can effectively improve intraoperative bleeding and promote early functional recovery of patients.This article reviews the mode of administration,safe dose,administration time and adverse drug reactions of tranexamic acid in the perioperative period of joint replacement and arthroscopic surgery,in order to provide reference for the clinical application of tranexamic acid.

In recent years, nucleic acid therapy, as a revolutionary therapeutic tool, has shown great potential in the treatment of genetic diseases, infectious diseases and cancer. Lipid nanoparticles (LNPs) are currently the most advanced mRNA delivery carriers, and their emergence is an important reason for the rapid approval and use of COVID-19 mRNA vaccines and the development of mRNA therapy. Currently, mRNA therapeutics using LNP as a carrier have been widely used in protein replacement therapy, vaccines and gene editing. Conventional LNP is composed of four components: ionizable lipids, phospholipids, cholesterol, and polyethylene glycol (PEG) lipids, which can effectively load mRNA to improve the stability of mRNA and promote the delivery of mRNA to the cytoplasm. However, in the face of the complexity and diversity of clinical diseases, the structure, properties and functions of existing LNPs are too homogeneous, and the lack of targeted delivery capability may result in the risk of off-targeting. LNPs are flexibly designed and structurally stable vectors, and the adjustment of the types or proportions of their components can give them additional functions without affecting the ability of LNPs to deliver mRNAs. For example, by replacing and optimizing the basic components of LNP, introducing a fifth component, and modifying its surface, LNP can be made to have more precise targeting ability to reduce the side effects caused by treatment, or be given additional functions to synergistically enhance the efficacy of mRNA therapy to respond to the clinical demand for nucleic acid therapy. It is also possible to further improve the efficiency of LNP delivery of mRNA through machine learning-assisted LNP iteration. This review can provide a reference method for the rational design of engineered lipid nanoparticles delivering mRNA to treat diseases.