Objective To investigate the detection rate,epidemiology and resistance mechanism of methicil-lin-resistant Staphylococcus aureus(MRSA)in a hospital in recent 5 years.Methods A total of 762 strains of non repetitive Staphylococcus aureus detected from 2016 to 2020 in a hospital were collected retrospectively.Methicillin-sensitive Staphylococcus aureus(MSSA)was 392 strains(MSSA group)and 370 strains caused by MRSA(MRSA group),and 95 strains of MRSA isolated in 2020 were further used for resistance mechanism.Staphylococcus aureus was identified and tested for drug sensitivity by Vitek 2 automatic microbial system.Molecular epidemiological typing was determined by multilocus sequence typing.The biofilm formation was performed by crystal violet staining.PCR amplification was used to detect drug resistance genes,virulence genes and biofilm related genes,and logistic regression analysis was used to investigate the independent risk factors of its occurrence.Results The detection rate of MRSA in past five years was 48.56％,mainly was from pus samples and secretion samples(38.38％,33.51％respectively).MRSA was found in the general sur-gery(18.65％)and otorhinolaryngology(12.70％).ST88 was the most common multilocus sequence typing(37.89％),and followed by ST951(24.21％).Moderate biofilm formation was the most common,accounting for 74.73％.Multivariate regression analysis showed that compared with MSSA group,hypoproteinemia,en-docrine system diseases,wound infection and history of antibiotic use within six months were the independent risk factors for infection in MRSA group.Compared with the control group,hospital transfer,wound infection and tumor were independent risk factors for infection in MRSA group(P＜0.05).Conclusion The detection rate of MRSA in a hospital is high,and the carrying rate of various drug-resistant genes is high.The hospital should pay attention to the prevalence of MRSA and related risk factors,so as to prevent it early.

Acute ST-segment elevation myocardial infarction with multivessel disease is one of the high-risk types of coronary heart disease.Early opening of infarct-related artery and reperfusion of myocardium could significantly reduce the mortality in acute phase.However,the presence of non-culprit lesions in non-infarct-related arteries is still at risk and has an important impact on the long-term prognosis of patients.It remains controversial on how to precisely evaluate the clinical significance and revascularization value of non-culprit lesions.This article aims to review the research status and progress of guidance strategies of non-culprit lesion revascularization in patients with ST-segment elevation myocardial infarction and multivessel disease.

The Flash radiotherapy(Flash-RT),which is the key breakthrough in the basic field of radiotherapy technique,which is expected to cause a new major transformation in the field of radiotherapy.In this paper,we reviewed the latest research advances of the application and the mechanism exploration of Flash-RT in tumor treatment.Current studies have found that both the Flash-RT with electron beams and photon and the Flash-RT with proton can reduce injury of normal tissue than radiotherapy with conventional dose-rate,but the relevant mechanisms are not yet clearly understood,which includes but not limited to oxygen depletion,DNA damage,cellular senescence,apoptosis and immune response.The difference of Flash-RT injury between tumor tissue and normal tissue further reduces the limitations of radiotherapy,and reduces the adverse reaction and complication compared with conventional radiotherapy,which has wide application prospects.

Objective To compare effectiveness between the modified and traditional pressure-overload myocardial hypertrophy(POMH) model by abdominal aorta coarctation (AAC) method. Methods Totally 45 rats were divided into three groups(n = 15 per group), sham group, traditional group, and modified group. In the traditional group, the diameter ol the abdominal aorta was narrowed to 0. 70 mm through a midline incision for 4 weeks; in the modified group, the diameter of the abdominal aorta was narrowed above the left kidney to 0. 45 mm for 1 week, and then the narrowing was lifted postoperatively. The cardiac index, heart weight (HW) /body weight (BW) and left ventricular index, left ventricular weight (LVW)/BW were measured from the heart specimens, and the cross-sectional area of cardiac myocytes, myocardial collagen area, and myocardial collagen area Iraction were measured in the pathological sections by HE staining and Masson staining. Results Compared with the sham group, the differences in end-systolic interventricular septum thickness (IVSs), left ventricular end-systolic posterior wall thickness (LVPWs), HW/BW, LVW/BW, cardiomyocyte cross-sectional area, myocardial collagen area, myocardial collagen area fraction, and brain natriuretic peptide (BNP) expression levels were statistically significant (P<0. 05) in the modilied and traditional groups of rats. The differences in these indices were not statistically significant between the modified and traditional groups (P>0. 05). Conclusion The modified abdominal aortic constriction method used in this experiment is time-saving, stable, homogeneous and easy to replicate, and is a more ideal approach to establish a rat model of POMH.

Objective To establish a mouse model of type Ⅰ tricho-hepato-enteric syndrome(THES)induced by Ttc37 deficiency.Methods Ttc37 flox strain was established by site-specifically inserted loxP sites into Ttc37 gene via CRISPR/CAS9 technology.Ubiquitously expressed CAG-Cre was introduced for all-tissue removal of Ttc37 in Ttc37flox/flox;CAG-Cre mice.The knock-out effect was confirmed by fluorescence quantitative PCR and Western blot.Phenotypic evaluations were conducted in 8-week-old mice including hematoxylin-eosin staining of skin,spleen,liver,bladder,and gastrointestinal tract(GI),serum enzyme activity assay of aspartate aminotransferase(AST)and alanine aminotransferase(ALT),measurement of serum hemoglobin level,and ELISA for IgG and IgM level upon antigen immunization.Results Similar to type Ⅰ THES patients,Ttc37flox/flox;CAG-Cre mice exhibited impaired development of hair shaft,epidermis,B cell and eyes,while liver,GI,bladder and serum hemoglobin level seemed normal under unstressed condition.Conclusion A novel mouse model of typeⅠ THES was constructed successfully,which was applicable for pathological study.

Objective To investigate the genetic causes of auditory neuropathy with optic atrophy in a family.Methods The proband's medical history and family history were inquired in detail,and relevant clinical examina-tions were performed to confirm the diagnosis of auditory neuropathy with optic atrophy,and the genetic pedigree of the family was drawn.Peripheral blood of proband(Ⅲ-7)was collected for whole exome sequencing,and the patho-genicity of the detected mutations were interpreted.Blood samples of proband's wife(Ⅲ-8),eldest daughter(Ⅳ-7),second daughter(Ⅳ-9)and son(Ⅳ-10)were tested for mutation sites by Sanger sequencing.Combined with clinical manifestations and examination results,the family was studied.Results The genetic pattern of this family was autosomal dominant.The proband showed decreased visual acuity at the age of 19,bilateral sensorineural deaf-ness at the age of 30,and decreased speech recognition rate.Among 20 members of the family of 5 generations,10(2 deceased)showed similar symptoms of hearing and visual impairment.Proband(Ⅲ-7),eldest daughter(Ⅳ-7)and son(Ⅳ-10)underwent relevant examination.Pure tone audiometry showed bilateral sensorineural deafness.ABR showed no response bilaterally.The 40 Hz AERP showed no response in both ears.OAE showed responses in some or all of the frequencies.No stapedial reflex was detected.The eye movement of Ⅲ-7 and Ⅳ-10 were reasona-ble in all directions,and color vision was normal.Ocular papilla atrophy was observed in different degrees in fundus examination.OCT showed thinning of optic disc nerve fibers in both eyes,and visual evoked potential showed pro-longed P100 wave peak.They were diagnosed as hereditary auditory neuropathy with optic atrophy.A mutation of the OPA1 gene c.1334G＞A(p.Arg445His,NM_015560.2)at a pathogenic locus on chromosome 3 was detected by whole exon detection in Ⅲ-7.The results of generation sequencing analysis showed that the OPA1 gene c.1334G＞A(p.Arg445His,NM_015560.2)mutation of chromosome 3 was also found in Ⅳ-7 and Ⅳ-10.Meanwhile,the gen-otypes of Ⅲ-8 and Ⅳ-9 were wild homozygous,that is,no mutation occurred.Conclusion The OPA1 c.1334G＞A(p.Arg445His,NM_015560.2)mutation site might be the pathogenic mutation in this family.

Objective To investigate the disease spectrum and pathogenic genes of inherited metabolic disorder(IMD)among neonates in Gansu Province of China.Methods A retrospective analysis was conducted on the tandem mass spectrometry data of 286 682 neonates who received IMD screening in Gansu Provincial Maternal and Child Health Hospital from January 2018 to December 2021.A genetic analysis was conducted on the neonates with positive results in tandem mass spectrometry during primary screening and reexamination.Results A total of 23 types of IMD caused by 28 pathogenic genes were found in the 286 682 neonates,and the overall prevalence rate of IMD was 0.63‰(1/1 593),among which phenylketonuria showed the highest prevalence rate of 0.32‰(1/3 083),followed by methylmalonic acidemia(0.11‰,1/8 959)and tetrahydrobiopterin deficiency(0.06‰,1/15 927).In this study,166 variants were identified in the 28 pathogenic genes,with 13 novel variants found in 9 genes.According to American College of Medical Genetics and Genomics guidelines,5 novel variants were classified as pathogenic variants,7 were classified as likely pathogenic variants,and 1 was classified as the variant of uncertain significance.Conclusions This study enriches the database of pathogenic gene variants for IMD and provides basic data for establishing an accurate screening and diagnosis system for IMD in this region.

Objective To investigate the application value of 3.0T MR apparent diffusion coefficient(ADC)in prognosis and pathological types of endometrial carcinoma(EC).Methods A total of 114 EC patients were retrospectively selected,and the ADC values of different pathological types were compared.The correlation between ADC and EC prognosis was analyzed by dividing the ADC quintile(Q1-Q5).Results The ADC parameters of EC patients with different pathological types were significantly different(P＜0.05).With the increase of ADC value,the correlation effect size between ADC and EC prognosis also increased(Ptrend＜0.001).ADC had a better predictive effect on EC prognosis.International Federation of Gynecology and Obstetrics(FIGO)stage,myographic invasion and ADC value had interaction with EC prognosis(P interaction＜0.05).Conclusion ADC can be used to distinguish the patho-logical types of EC.Also,ADC is significantly associated with EC prognosis while its correlation effect size increases with the increase of ADC value.ADC value interacted with FIGO stage,as well as with the degree of myographic invasion in predicting EC prognosis.

Background and purpose:Breast cancer is a major global public health problem.Bone is the most common site of distant metastasis of breast cancer,accounting for about 70%of all metastatic cases.Bone metastasis of breast cancer can cause a series of complications,including severe pain,pathological fracture,hypercalcemia,spinal cord compression,etc.,which bring great inconvenience to patients'physical activities and affect their quality of life.Metastatic recurrence is the leading cause of death in breast cancer patients.Therefore,there is an urgent need to build a diagnostic model of bone metastasis in breast cancer to identify patients with a high risk of bone metastasis.The aim of this study was to develop a predictive model based on machine learning to predict the probability of breast cancer developing bone metastasis.Methods:Data of breast cancer patients diagnosed between 2010 and 2015 were extracted from The Surveillance,Epidemiology,and End Results(SEER)database.The variables were screened by least absolute shrinkage and selection operator(LASSO)regression,univariate and multivariate logistic regression analysis,and statistically significant risk factors were included to build a prediction model.In this study,nine machine learning algorithms,including decision tree,elastic network,K-nearest neighbor,lightweight gradient elevator,logistic regression,neural network,random forest,support vector machine and limit gradient lifting,were used to adjust the model hyperparameters through random search and 5x cross-validation to build a breast cancer bone metastasis prediction model.The area under the receiver operating characteristic(ROC)curve,calibration curve and decision curve were used to evaluate the model,the optimal model was obtained,and the importance of variables was analyzed based on the optimal model.Finally,a network calculator for predicting the risk of bone metastasis of breast cancer was established using the optimal model.Results:The study included 10 106 patients with breast cancer,7 073 patients in the training set,and 3 033 patients in the validation set.We found that 4 494(63.5%)patients in the training set and 1 927(63.5%)patients in the validation set developed bone metastases,respectively.Race,pathologic grade,estrogen receptor(ER)status,progesterone receptor(PR)status,human epidermal growth factor receptor 2(HER2)status,N stage,lung metastasis,radiotherapy,chemotherapy and surgery were independent predictors of bone metastasis.The training set and verification set were used to verify the model,and the limit gradient lifting algorithm was superior to other machine learning algorithms by integrating the evaluation indexes such as the area under the ROC curve,calibration curve and decision curve.Finally,we used limit gradient algorithm to build network calculator for prediction of breast cancer bone metastases(https://bcbm.shinyapps.io/DynNomapp/).Conclusion:This study developed a predictive model based on machine learning to predict the probability of bone metastases in breast cancer patients,hoping to help clinicians make more rational treatment decisions.

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.