Objective The study aimed to investigate the predictive efficacy of contrast-enhanced ultrasound combined with telomerase reverse transcriptase(TERT)promoter mutation in constructing nomogram model for the prediction of concomitant cervical lymph node metastasis(CLNM)in papillary thyroid microcarcinoma(pTMC).Methods A total of 202 patients with pTMC who underwent partial or total thyroidectomy+lymph node dissection at our hospital from January 2021 to March 2024 were selected.Then,they were divided into the CLNM group(97 patients)and the non-CLNM group(105 patients)according to whether they had concomitant CLNM on postoperative pathological examination.General data and ultrasound(conventional ultrasound and contrast-enhanced ultrasound)characteristics were collected from all patients with pTMC,and Sanger sequencing was used to detect TERT promoter mutations.The influencing factors of pTMC complicated by CLNM were analyzed by single-factor and multifactorial unconditional logistic regression;the nomogram model of pTMC complicating CLNM with contrast-enhanced ultra-sound combined with TERT promoter mutation was constructed by RStudio 4.4.1 software,and the consistency and net benefit of the nomogram model were evaluated by using calibration curves,decision curves,and C-indexes,and the Hosmer-Lemeshow test for goodness of fit of the nomogram model;The predictive efficiency of the nomogram model constructed by combining contrast-enhanced ultrasound and TERT promoter mutation for pTMC complicated by CLNM was evaluated by plotting receiver operating characteristic(ROC)curves using MedCalc22.023 software.Results After postoperative pathological examination,the incidence of CLNM in 202 patients with pTMC was 48.02%(97/202).Univariate analysis showed that thyroglobulin antibodies,number of lesions,aspect ratio,micro-calcifications,enhancement time,enhancement mode,enhancement intensity,capsular continuity,and TERT promoter mutations were associated with pTMC complicating CLNM(P<0.05).Multifactorial unconditional logistic regression showed that multifocal tumours(OR=3.487,95%CI:1.641～7.406,P=0.001),microcalcifications(OR=4.484,95%CI:2.113～9.516,P<0.001),equal or high enhancement(OR=3.187,95%CI:1.460～6.957,P=0.004),disruption of peritoneal continuity(OR=2.201,95%CI:1.051～4.608,P=0.036),and TERT promoter mutation positivity(OR=4.460,95%CI:2.132～10.103,P<0.001)were the independent risk factors for pTMC complicating CLNM.A contrast-enhanced ultrasound combined TERT promoter mutation nomogram model was constructed based on independent risk factors for pTMC complicating CLNM[Logit(p)=-4.486+1.350×number of foci+1.399×microcalcifications+2.124×intensity of enhancement+1.524×capsular continuity+2.175×TERT promoter mutations].The C-index of this nomogram model was 0.899(95%CI:0.893～0.905),the calibra-tion curve alignment was close to the ideal curve,the decision curve was higher than the two extreme curves,and the Hosmer-Lemeshow test showed a P>0.05.The ROC curve analysis showed that the nomogram model constructed with contrast-enhanced ultrasound combined with TERT promoter mutations predicted CLNM in pTMC with an area under the curve of 0.899.This was significantly higher than the area under the curves for contrast-enhanced ultra-sound alone(0.857)and TERT promoter mutations alone(0.697)(P<0.05).Conclusion The contrast-enhanced ultrasound combined with TERT promoter mutations to construct a nomogram model has high predictive efficiency for pTMC complicating CLNM.

The 2024 National Education Work Conference pointed out that at the current juncture of the critical period for achieving the goals and tasks of the 14th Five-Year Plan,the implementation of the Education Powerhouse Construction Plan Outline should be taken as the main line of work,and building first-class disciplines is an crucial task for a higher education powerhouse.In 2022,forensic medicine was officially listed as a first-level discipline under the medical category,presenting an un-precedented historical opportunity for the development of forensic medicine.The forensic medicine dis-cipline of Southern Medical University comprehensively improves the quality of talent cultivation and facilitates the construction of first-class disciplines as its main direction.It aims to initiate and imple-ment a high-level faculty team building plan featuring"combining recruitment and cultivation,inter-disciplinary integration";make vigorous efforts to establish a first-level doctoral program,refine advan-tageous second-level disciplines and research directions;and establish an innovative research platform from a high starting point with deep integration.The discipline adheres to moral cultivation and the Five Domains of Education simultaneous development,to build a high-quality talent joint training model.Guided by the construction of the national legal system and industry needs,the discipline will enhance social service capabilities.The forensic medicine construction in our university will continue to contribute to the rule of law in China and educational power.

Objective To investigate the differences in demographic characteristics,reproductive health status,and the distribution of pregnancy-related diseases between couples conceived via assisted reproductive technology(ART)and naturally conceived couples,and to analyze the impact of ART treatment on the incidence of preterm birth(PTB)in singleton and twin and multiple pregnancies.Methods We conducted a retrospective analysis of the maternal and infant cohort data of Jing'an District from 2013 to 2020.Based on the conception method,the subjects were categorized into two groups:the ART group and the natural conception group.Chi-square test was applied to compare baseline characteristics and disease distributions differences between the two groups,and logistic regression models were used to evaluate the association between ART and the PTB risks.A causal mediation model was used to evaluate the mediating effect of twin and multiple pregnancy in the relationship between ART and PTB.Results A total of 117 717 parturients were included,6 265 in the ART group and 111 452 in the natural conception group.Compared with the natural conception group,couples in the ART group were significantly older and had a higher prevalence of reproductive system diseases.The incidences of diabetes and hypertensive disorders during pregnancy in ART parturient were 13.76%and 9.99%,respectively,which were significantly higher than 7.88%and 4.75%in the natural conception group(both P<0.001).The overall PTB rate in the ART group was 14.81%,higher than 5.35%in the natural conceptions group(P<0.001).The PTB rate in ART for singleton pregnancies in the ART group was 6.40%,higher than 4.83%in the natural conception group(P<0.001),while the PTB rate in ART for twin and multiple pregnancies in the ART group was 53.97%,lower than 60.42%in the natural conception group(P<0.05).Mediation analysis showed that 97.99%of the effect of ART on PTB was mediated by twin and multiple pregnancy,with ART increasing the PTB risk by 3.44 times through multiple pregnancy.Conclusion The overall PTB rate of ART recipients is higher than that of natural recipients,but ART does not increase the PTB risk in singleton and twin and multiple pregnancies.Twin and multiple pregnancy is the key mediating factor contributing to PTB in ART-conceived recipients.Compared with naturally conceived couples,ART conception couples own more advanced maternal age,and have higher risks of suffering gestational diabetes,gestational hypertension,and PTB.

This study investigates the mechanism by which Xintong Granules improve myocardial ischemia-reperfusion injury(MIRI) through the regulation of gut microbiota and their metabolites, specifically short-chain fatty acids(SCFAs). Rats were randomly divided based on body weight into the sham operation group, model group, low-dose Xintong Granules group(1.43 g·kg~(-1)·d~(-1)), medium-dose Xintong Granules group(2.86 g·kg~(-1)·d~(-1)), high-dose Xintong Granules group(5.72 g·kg~(-1)·d~(-1)), and metoprolol group(10 mg·kg~(-1)·d~(-1)). After 14 days of pre-administration, the MIRI rat model was established by ligating the left anterior descending coronary artery. The myocardial infarction area was assessed using the 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Apoptosis in tissue cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL) assay. Pathological changes in myocardial cells and colonic tissue were observed using hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), creatine kinase MB isoenzyme(CK-MB), and cardiac troponin T(cTnT) in rat serum were quantitatively measured using enzyme-linked immunosorbent assay(ELISA) kits. The activities of lactate dehydrogenase(LDH), creatine kinase(CK), and superoxide dismutase(SOD) in myocardial tissue, as well as the level of malondialdehyde(MDA), were determined using colorimetric assays. Gut microbiota composition was analyzed by 16S rDNA sequencing, and fecal SCFAs were quantified using gas chromatography-mass spectrometry(GC-MS). The results show that Xintong Granules significantly reduced the myocardial infarction area, suppressed cardiomyocyte apoptosis, and decreased serum levels of pro-inflammatory cytokines(TNF-α, IL-1β, and IL-6), myocardial injury markers(CK-MB, cTnT, LDH, and CK), and oxidative stress marker MDA. Additionally, Xintong Granules significantly improved intestinal inflammation in MIRI rats, regulated gut microbiota composition and diversity, and increased the levels of SCFAs(acetate, propionate, isobutyrate, etc.). In summary, Xintong Granules effectively alleviate MIRI symptoms. This study preliminarily confirms that Xintong Granules exert their inhibitory effects on MIRI by regulating gut microbiota imbalance and increasing SCFA levels.
Animals ; Gastrointestinal Microbiome/drug effects* ; Rats ; Male ; Myocardial Reperfusion Injury/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Apoptosis/drug effects* ; Humans ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/genetics* ; Malondialdehyde/metabolism*

Objective The study aimed to investigate the predictive efficacy of contrast-enhanced ultrasound combined with telomerase reverse transcriptase(TERT)promoter mutation in constructing nomogram model for the prediction of concomitant cervical lymph node metastasis(CLNM)in papillary thyroid microcarcinoma(pTMC).Methods A total of 202 patients with pTMC who underwent partial or total thyroidectomy+lymph node dissection at our hospital from January 2021 to March 2024 were selected.Then,they were divided into the CLNM group(97 patients)and the non-CLNM group(105 patients)according to whether they had concomitant CLNM on postoperative pathological examination.General data and ultrasound(conventional ultrasound and contrast-enhanced ultrasound)characteristics were collected from all patients with pTMC,and Sanger sequencing was used to detect TERT promoter mutations.The influencing factors of pTMC complicated by CLNM were analyzed by single-factor and multifactorial unconditional logistic regression;the nomogram model of pTMC complicating CLNM with contrast-enhanced ultra-sound combined with TERT promoter mutation was constructed by RStudio 4.4.1 software,and the consistency and net benefit of the nomogram model were evaluated by using calibration curves,decision curves,and C-indexes,and the Hosmer-Lemeshow test for goodness of fit of the nomogram model;The predictive efficiency of the nomogram model constructed by combining contrast-enhanced ultrasound and TERT promoter mutation for pTMC complicated by CLNM was evaluated by plotting receiver operating characteristic(ROC)curves using MedCalc22.023 software.Results After postoperative pathological examination,the incidence of CLNM in 202 patients with pTMC was 48.02%(97/202).Univariate analysis showed that thyroglobulin antibodies,number of lesions,aspect ratio,micro-calcifications,enhancement time,enhancement mode,enhancement intensity,capsular continuity,and TERT promoter mutations were associated with pTMC complicating CLNM(P<0.05).Multifactorial unconditional logistic regression showed that multifocal tumours(OR=3.487,95%CI:1.641～7.406,P=0.001),microcalcifications(OR=4.484,95%CI:2.113～9.516,P<0.001),equal or high enhancement(OR=3.187,95%CI:1.460～6.957,P=0.004),disruption of peritoneal continuity(OR=2.201,95%CI:1.051～4.608,P=0.036),and TERT promoter mutation positivity(OR=4.460,95%CI:2.132～10.103,P<0.001)were the independent risk factors for pTMC complicating CLNM.A contrast-enhanced ultrasound combined TERT promoter mutation nomogram model was constructed based on independent risk factors for pTMC complicating CLNM[Logit(p)=-4.486+1.350×number of foci+1.399×microcalcifications+2.124×intensity of enhancement+1.524×capsular continuity+2.175×TERT promoter mutations].The C-index of this nomogram model was 0.899(95%CI:0.893～0.905),the calibra-tion curve alignment was close to the ideal curve,the decision curve was higher than the two extreme curves,and the Hosmer-Lemeshow test showed a P>0.05.The ROC curve analysis showed that the nomogram model constructed with contrast-enhanced ultrasound combined with TERT promoter mutations predicted CLNM in pTMC with an area under the curve of 0.899.This was significantly higher than the area under the curves for contrast-enhanced ultra-sound alone(0.857)and TERT promoter mutations alone(0.697)(P<0.05).Conclusion The contrast-enhanced ultrasound combined with TERT promoter mutations to construct a nomogram model has high predictive efficiency for pTMC complicating CLNM.

Objective To investigate the differences in demographic characteristics,reproductive health status,and the distribution of pregnancy-related diseases between couples conceived via assisted reproductive technology(ART)and naturally conceived couples,and to analyze the impact of ART treatment on the incidence of preterm birth(PTB)in singleton and twin and multiple pregnancies.Methods We conducted a retrospective analysis of the maternal and infant cohort data of Jing'an District from 2013 to 2020.Based on the conception method,the subjects were categorized into two groups:the ART group and the natural conception group.Chi-square test was applied to compare baseline characteristics and disease distributions differences between the two groups,and logistic regression models were used to evaluate the association between ART and the PTB risks.A causal mediation model was used to evaluate the mediating effect of twin and multiple pregnancy in the relationship between ART and PTB.Results A total of 117 717 parturients were included,6 265 in the ART group and 111 452 in the natural conception group.Compared with the natural conception group,couples in the ART group were significantly older and had a higher prevalence of reproductive system diseases.The incidences of diabetes and hypertensive disorders during pregnancy in ART parturient were 13.76%and 9.99%,respectively,which were significantly higher than 7.88%and 4.75%in the natural conception group(both P<0.001).The overall PTB rate in the ART group was 14.81%,higher than 5.35%in the natural conceptions group(P<0.001).The PTB rate in ART for singleton pregnancies in the ART group was 6.40%,higher than 4.83%in the natural conception group(P<0.001),while the PTB rate in ART for twin and multiple pregnancies in the ART group was 53.97%,lower than 60.42%in the natural conception group(P<0.05).Mediation analysis showed that 97.99%of the effect of ART on PTB was mediated by twin and multiple pregnancy,with ART increasing the PTB risk by 3.44 times through multiple pregnancy.Conclusion The overall PTB rate of ART recipients is higher than that of natural recipients,but ART does not increase the PTB risk in singleton and twin and multiple pregnancies.Twin and multiple pregnancy is the key mediating factor contributing to PTB in ART-conceived recipients.Compared with naturally conceived couples,ART conception couples own more advanced maternal age,and have higher risks of suffering gestational diabetes,gestational hypertension,and PTB.

Objective To investigate the biological function and main molecular mechanism of long noncoding RNA RMRP(lncRNA RMRP)in endometrial carcinoma.Methods The specimens of carcinoma tissues and adjacent tissues of 30 patients with endometrial carcinoma who received surgical treatment in our hospital were collected.RT-qPCR was used to detect the expression of lncRNA RMRP in endometrial carcinoma tissues and adjacent tissues,and HESC cells and HEC-1-A cells.The endometrial carcinoma cell line HEC-1-A was cultured in vitro,and the Vector,pcDNA-RMRP,NC-siRNA,RMRP-siRNA,NC mimic,miR-580-3p mimic,pcDNA-RMRP+NC mimic,pcDNA-RMRP+ miR-580-3p mimic,RMRP-siRNA+Vector,RMRP-siRNA+pcDNA-JAK2,NC inhibitor,and miR-580-3p inhibitor were transfected into HEC-1-A cells as the Vector group,the pcDNA-RMRP group,the NC-siRNA group,the RMRP-siRNA group,the NC mimic group,the miR-580-3p mimic group,the pcDNA-RMRP+NC mimic group,the pcDNA-RMRP+miR-580-3p mimic group,the RMRP siRNA+Vector group,the RMRP-siRNA+pcDNA-JAK2 group,the NC inhibitor group,and the miR-580-3p inhibitor group respectively.RT-qPCR was used to detect the expression of lncRNA RMRP and miR-580-3p in cells.CCK-8 was used to detect cell proliferation rate.The apoptosis rate was detected by flow cytometry analysis.Bioinformatics software and dual luciferase reporter gene experiment were used to predict and verify the targeted relationships between miR-580-3p and lncRNA RMRP,as well as miR-580-3p and JAK2.Western blot was used to detect the protein expression of JAK/STAT signaling pathway.Results Compared with adjacent tissues,lncRNA RMRP was highly expressed in endometrial carcinoma tissues(P<0.05).Compared with HESC cells,the expression of lncRNA RMRP in HEC-1-A cells was significantly increased(P<0.05).pcDNA-RMRP significantly promoted cell proliferation and inhibited cell apoptosis,while RMRP-siRNA significantly inhibited cell proliferation and promoted cell apoptosis,with statistically significant diferences(P<0.05).miR-580-3p was the downstream target miRNA of lncRNA RMRP,and lncRNA RMRP could negatively regulate the expression of miR-580-3p.JAK2 was the downstream target gene of miR-580-3p,and miR-580-3p could negatively regulate the expression of JAK2 protein.pcDNA-RMRP significantly increased the protein levels of JAK2,p-JAK2 and p-STAT3 in the cells,while co-transfection of pcDNA-RMRP and miR-580-3p mimic significantly decreased the protein levels of JAK2,p-JAK2 and p-STAT3,with statistically significant diferences(P<0.05).RMRP-siRNA could signifi-cantly reduce the protein levels of JAK2,p-JAK2 and p-STAT3 in cells.After co-transfection of RMRP-siRNA and pcDNA-JAK2,the protein levels of JAK2,p-JAK2 and p-STAT3 were significantly increased,with statistically significant diferences(P<0.05).In addition,co-transfection of RMRP-siRNA and pcDNA-JAK2 increased cell proliferation and decreased cell apoptosis,with statistically significant diferences(P<0.05).Conclusion Knockdown of lncRNA RMRP could inhibit endometrial carcinoma cell proliferation and promote cell apoptosis by regulating JAK2/STAT3 signaling pathway,which might be a potential therapeutic target for endometrial carcinoma.

Objective To understand the pathogen detection of hospitalized patients before antimicrobial therapy in a hospital through implementation of comprehensive intervention measures,and provide reference basis for the de-velopment of targeted measures.Methods Hospitalized patients who received therapeutic antimicrobial agents in this hospital were selected as the research subjects.Patients who were hospitalized from January to May 2022 were selected as the pre-intervention group,comprehensive intervention measures were taken from June to October 2022,and those who were hospitalized from November 2022 to March 2023 were selected as the post-intervention group.The pathogen detection rate before antimicrobial therapy,sterile specimen detection rate,antimicrobial use rate,de-tection rate of key multidrug-resistant organisms of patients before and after the intervention were analyzed.Results Compared to before intervention,the proportion of pathogen detection rate before antimicrobial therapy(62.09％vs 74.04％),detection rate of healthcare-associated infection diagnosis-related pathogens(62.82％vs 92.73％),and sterile specimen detection rate(35.17％vs 41.06％)of hospitalized patients after intervention all increased signifi-cantly,with statistically significant differences(all P＜0.05).After intervention,pathogen detection rate before the combination use of key antimicrobial agents was not statistically different from before intervention(93.33％vs 90.48％,P＞0.05),while antimicrobial use rate was lower than before intervention(39.93％vs 44.95％,P＜0.05).There was no statistically significant difference in the detection rate of key multidrug-resistant organisms be-fore and after intervention(all P＞0.05).Conclusion Adopting scientific and rational intervention measures can improve the pathogen detection rate,provide a reference basis for the rational use of antimicrobial agents.There was no significant improvement in the pathogen detection rate before the combination use of key antimicrobial agents and the detection rate of key multidrug-resistant organisms,indicating that relevant measures still need to be further optimized.

Objective:To explore the application value of reticulocyte hemoglobin equivalent(Ret-He)for diagnosing latent iron deficiency in female plateletpheresis donors.Methods:A total of 230 female plateletpheresis donors in Fujian Blood Center from January to February 2022 were selected as the research group and divided into three groups:normal group,iron depletion(ID)group and iron deficient erythropoiesis(IDE)group,according to the severity of iron deficiency.The level of hemoglobin(HGB),mean corpuscular volume(MCV),mean corpuscular hemoglobin(MCH),coefficient of variation of red cell distribution width(RDW-CV)and Ret-He were measured by using the Sysmex XN automated hematology analyzer.Chemiluminescence immunoassay was used to detect iron biochemical indexes.Receiver operating characteristic(ROC)curve analysis was performed to evaluate the diagnosic value of relevant indicators in female blood donors with latent iron deficiency.Results:Ret-He in ID group was 32.55(31.15,33.10)pg,which was significantly lower than that in the normal group[33.80(32.73,34.70)pg](P＜0.05),and significantly higher than that in IDE group[30.40(28.70,31.50)pg](P＜0.05).ROC analysis in diagnosis of IDE demonstrated that the area under the curves(AUCs)of HGB,MCV,MCH,RDW-CV and Ret-He were 0.892,0.843,0.909,0.890,0.931,respectively.When the critical value of Ret-He was 32.05 pg,its sensitivity and specificity were 85.90％and 92.60％,respectively.However,all red blood cell parameters had poor diagnostic value for ID.Conclusion:Ret-He is a perfect predictor for latent iron deficiency in female blood donors.Detection of Ret-He can advance the diagnosis of iron deficiency in female blood donors to the IDE stage.

Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34⁺⁰ weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.
Infant ; Infant, Newborn ; Humans ; Birth Weight ; Intensive Care Units, Neonatal ; Retrospective Studies ; Tertiary Care Centers ; Infant, Extremely Low Birth Weight ; Gestational Age ; Infant, Extremely Premature ; Sepsis/epidemiology* ; Retinopathy of Prematurity/epidemiology* ; Bronchopulmonary Dysplasia/epidemiology*