The expanded clinical trial system is designed to provide clinical trial drugs for patients suffering from serious or life-threatening diseases for which there is no effective treatment， essentially seeking a balance between the accessibility of drugs to patients and the soundness of the development of the pharmaceutical industry， as well as between the risk of expanding the use of clinical trial drugs and the need to safeguard the rights and interests of patients’ lives and health. Article 23 of China's Drug Administration Law provides only a principled description of the applicable standards and operating procedures for this system， with no implementing regulations， making it difficult for the system to function effectively in practice. The United States， Japan， and Canada have made detailed provisions on the conditions of application， applicants， review subjects and contents， and safeguards of the system through laws， regulations， and guidelines. Based on China's legislative environment and regulatory reality， and considering that the system is still in the initial stage in China， it is recommended that appropriate reference be made to the beneficial experience of foreign countries and that regulations and normative documents be promulgated as soon as possible to clarify the types of expanded clinical trials， applicants， review subjects etc.， and to determine the responsibilities of all the parties involved， to promote the standardization of China’s expanded clinical trial system， to promote the availability of medicines to patients， and to effectively safeguard the rights and interests of patients’ lives and health， and the soundness and safety of the development of the pharmaceutical industry.

Schwann cells and macrophages are the main immune cells involved in peripheral nerve injury. After injury, Schwann cells produce an inflammatory response and secrete various chemokines, inflammatory factors, and some other cytokines to promote the recruitment and M2 polarization of blood-derived macrophages, enhancing their phagocytotic ability, and thus play an important role in promoting nerve regeneration. Macrophages have also been found to promote vascular regeneration after injury, promote the migration and proliferation of Schwann cells along blood vessels, and facilitate myelination and axon regeneration. Therefore, there is a close interaction between Schwann cells and macrophages during peripheral nerve regeneration, but this has not been systematically summarized. In this review, the mechanisms of action of Schwann cells and macrophages in each other's migration and phenotypic transformation are reviewed from the perspective of each other, to provide directions for research on accelerating nerve injury repair.
Schwann Cells/metabolism* ; Peripheral Nerve Injuries/physiopathology* ; Animals ; Macrophages/immunology* ; Nerve Regeneration/physiology* ; Humans ; Cell Movement/physiology*

Objective:To study the clinical manifestations, genetic profiles and treatment of Kagami-Ogata syndrome (KOS).Methods:A neonate admitted to our hospital was genetically diagnosed of KOS from amniocentesis sampling. The phenotype, genotype and treatment of the neonate were analyzed. Multiple databases were searched using key words including "Kagami-Ogata syndrome", "14q32 microdeletion syndrome", "coat-hanger ribs", "paternal uniparental disomy (pUPD)(14) " from the inception of the databases to Jan. 23th 2023. The clinical features, genotype and treatment of patients from the literature were summarized.Results:The neonate in our hospital was born at 30 weeks gestational age with a birth weight of 2 035 g. Prenatal ultrasound indicated overgrowth, bilateral fetal renal pelvis dilatation (FRPD), dilatation of intestines in lower abdomen, clenched hands with overlapping fingers and polyhydramnios. After birth, the neonate showed progressively worsening respiratory distress, distinct facial features (small jaw, short neck, flat nasal bridge, upward-facing nostrils, small and malformed ears with auricular deformity and narrow external auditory canals), bell-shaped thorax, diastasis recti and abnormal posture (overlapping fingers, clenched fists), as well as feeding difficulties, recurrent fever and dependence of respiratory support. Whole exome sequencing (WES) revealed a 268.2Kb deletion (101034306_101302541) in 14q32.2 region on both the neonate and the mother and the father was otherwise normal. The prognosis was poor and the parents refused further treatment. The neonate died at one month of age after two days of palliative care. A total of 36 articles were identified in the literature review, including 78 KOS cases with complete clinical data (a total of 79 cases adding our case).The primary clinical manifestations included distinctive facial and thoracic abnormalities (79/79, 100%), polyhydramnios (71/75, 94.7%), feeding difficulties (55/63, 87.3%), abdominal wall defects (57/72, 79.2%), joint contractures (39/70, 55.7%) and dependence of respiratory support (29/56, 51.8%). Long-term follow-up revealed 86.8% (59/68) experienced physical, movement and intellectual development delay, 39.7% (25/63) died or gave up treatments within five years. Genetic testing showed pUPD in 44 cases (55.7%), maternal deletions in 23 cases (29.1%), epimutations in 8 cases (10.1%) and unreported variations in 4 cases (5.1%).Conclusions:KOS is a genetic imprinting disorder affecting multiple organs. Prenatal screening can detect abnormalities such as polyhydramnios. Specific clinical signs, radiological findings and 14q32 gene analysis are helpful for the diagnosis of the disease.

Objective:To study the clinical characteristics and risk factors of nephrocalcinosis in preterm infants.Methods:From March 2021 to August 2021, all preterm infants admitted to NICU of our hospital were retrospectively analyzed. The infants were assigned into nephrocalcinosis group and non-nephrocalcinosis group according to urinary tract ultrasound. Clinical data including gestational age, birth weight(BW), nutritional support strategy and complications were reviewed.Results:A total of 40 preterm infants (<34 weeks) were enrolled. 9 cases were in the nephrocalcinosis group and 31 cases in the non-nephrocalcinosis group. The nephrocalcinosis group had lower BW[(1 167±214) g vs.(1 586±215) g], higher calcium [6.9 (5.1, 8.7) g vs.3.3 (2.1, 6.8) g] and vitamin D intake [3.2(2.5, 4.2)×10 4U vs.1.7(1.1, 3.2)×10 4U] during hospitalization. No significant differences existed between the two groups on the following items:blood calcium and phosphate, 25-hydroxyvitamin D, feeding strategy, time to reach full enteral feeding(TFF), furosemide dosage and respiratory support duration ( P>0.05). In the nephrocalcinosis group, the median age of diagnosing nephrocalcinosis was 40.0(30.0, 52.5)d after birth. 5 cases showed bilateral nephrocalcinosis. 5 cases in the nephrocalcinosis group received renal tubule function examination,4 cases had increased urine β2 microglobulin and 2 cases had increased urine α1 microglobulin. 7 cases had elevated urine calcium in the nephrocalcinosis group. Follow-up showed that nephrocalcinosis disappeared 3-9 months after birth. Conclusions:BW, total calcium and vitamin D intake are risk factors for nephrocalcinosis in preterm infants. Increased urine β2 microglobulin and calcium levels are common co-morbidities in preterm infants with nephrocalcinosis.

Objective:To compare the short-term outcomes of very low birth weight (VLBW) and extremely low birth weight (ELBW) infants supplementarily fed with fortified donor human milk (DHM) or preterm formula (PF) when the mother's own milk (MOM) is insufficient.Methods:This retrospective cohort study included 91 VLBW or ELBW preterm infants with birth weight<1 500 g who were hospitalized in Peking Union Medical College Hospital from October 1, 2017, to September 30, 2020. Based on the supplemental feeding method when MOM was insufficient, these infants were divided into the DHM group ( n=51) and PF group ( n=40). Mann-Whitney U, t-test, Chi-square test, or Fisher's exact test were used to compare the short-term clinical outcomes during hospitalization between the two groups. Results:(1) There were no statistically significant differences between the 91 preterm infants in the DHM group and PF group in their gestational age, birth weight, sex ratio, birth mode, mothers' age at delivery, or the proportion of infants of small gestational age (all P>0.05). (2) The feeding volume in the DHM group was significantly greater than that in the PF group on the 14th day after birth [(108.2±53.1) vs. (81.0±47.8) ml/(kg·d), t=0.78, P=0.020]. Moreover, the time to achieve the feeding amounts up to 120 ml/(kg·d) and 150 ml/(kg·d) for infants in the DHM group were significantly shorter than those in the PF group [(17.5±10.2) vs. (30.0±12.0) d, t=4.38; (22.1±13.3) vs. (32.3±11.9) d, t=0.02; both P<0.05]; (3) Lower proportion of peripherally inserted central catheter (PICC) [58.8% (30/51) vs. 100% (40/40), χ 2=21.88, P<0.001] and shorter PICC duration were observed in the DHM group [10.0 (0.0-19.0) vs. 29.0 (17.0-40.5) d, Z=5.56, P<0.001] compared to the PF group. The times of red blood cell transfusions and the incidence of late sepsis in the DHM group were less than those in the PF group [0.0 (0.0-2.0) vs. 2.0 (1.0-3.0) times, Z=4.44, P<0.001; 23.5% (12/51) vs. 50.0% (20/40), χ 2=6.39, P=0.011]. There were no statistically significant differences observed in the incidence of bronchopulmonary dysplasia, neonatal necrotizing enterocolitis, retinopathy of prematurity, and the length of hospitalization (all P>0.05). Conclusion:When MOM is insufficient, supplementing VLBW and ELBW infants with fortified donor human milk can shorten the time to achieve enteral nutrition and reduce the use rate and time of PICC, the incidence of late-onset sepsis, and the times of red blood cell transfusion.

Objective The occurrence of chickenpox in rapidly developing areas poses substantial seasonal risk to children.However,certain factors influencing local chickenpox outbreaks have not been studied.Here,we examined the relationship between spatial clustering,heterogeneity of chickenpox outbreaks,and socioeconomic factors in Southern China. Methods We assessed chickenpox outbreak data from Southern China between 2006 and 2021,comprising both relatively fast-growing parts and slower sub-regions,and provides a representative sample of many developing regions.We analyzed the spatial clustering attributes associated with chickenpox outbreaks using Moran's I and local indicators of spatial association and quantified their socioeconomic determinants using Geodetector q statistics. Results There were significant spatial heterogeneity in the risk of chickenpox outbreaks,with strong correlations between chickenpox risk and various factors,particularly demographics and living environment.Furthermore,interactive effects among specific are factors,such as population density and per capita residential building area,percentage of households with toilets,percentage of rental housing,exhibited q statistics of 0.28,0.25,and 0.24,respectively. Conclusion This study provides valuable insights into the spatial dynamics of chickenpox outbreaks in rapidly developing regions,revealing the socioeconomic factors affecting disease transmission.These implications extend the formulation of effective public health strategies and interventions to prevent and control chickenpox outbreaks in similar global contexts.

Objective:To characterize the antimicrobial resistance, resistance machanism and population genetics of Salmonella( S.) Derby in China, preliminarily reveal the population genetic characteristics of S. Derby in China, discover possible transmission patterns or potential transmission pathways, and provide certain reference for strengthening S. disease monitoring and developing prevention and control strategies. Methods:A total of 201 strains of S. Derby from different areas in China were used for the susceptible tests to 16 antibiotics and whole-genome sequencing. Finally, combined with the genome sequences of 134 strains of S. Derby from public databases, 335 strains of S. Derby were used for resistance genotype analysis and multi-locus sequence typing (MLST), and a phylogenetic tree based on the core genome single nucleotide polymorphisms was constructed for evolutionary analysis. Results:The results showed that 201 strains of S. Derby showed resistance to 16 kinds of antibiotics at different levels. The overall resistance rate was 97.51%. The resistance rates to antibiotics varied in S. Derby from different sources (human, animal, and food), the differences were significant (all P<0.05). A total of 38 resistance genes were carried by 335 strains of S. Derby, of which, fosfomycin gene fosA7 was found in all the strains (100.00%) and aminoglycoside genes aac(6')-Iaa accounted for 99.70%. The consistency of resistance genes and phenotypes varied with antibiotics. Except aminoglycosides and chloramphenicol, the consistencies of resistance genes and phenotypes for other antibiotics were high. MLST showed that 334 strains of S. Derby belonged to ST40. Phylogenetic trees indicated the risk for cross-infection between animal and human, food and human, and the possibility of long-distance interprovincial transmission of the bacteria by animal, to which further epidemiological studies are needed. Conclusions:The drug resistance of S. Derby is serious in China and the risk for cross-transmission between human and animal or food exists. It is necessary to establish and strengthen the comprehensive surveillance and risk assessment to prevent the spread of antibiotic resistant strains or elements through animal, food and human chains.

Objective:To establish a matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) assay for the identification of common Salmonella serotypes and provide etiology evidence for the early precise treatment of salmonellosis. Methods:A total of 500 strains were collected from different regions and sources and five predominant Salmonella serotypes ( Salmonella Typhi , Salmonella Paratyphi A , Salmonella Typhimurium , Salmonella Enteritidis , and Salmonella Indiana) of each strain was identified by agglutination test and whole-genome sequencing. The protein complex of the strains was extracted by using optimized pretreatment method to establish the fingerprint database of peptides for each Salmonella serotype. The new serotyping assays were established by using different modules based on the mass spectra database. Additional 155 strains with specified serotypes and variant sources were used to test and evaluate the accuracy of the new typing assays. Results:Five MALDI-TOF MS databases were established, and two new serotyping assays were established via peptide fingerprint mapping/matching and machine learning of the neuronal convolutional network respectively based on the databases. The results showed that the fingerprint matching approach could quickly identify five common Salmonella serotypes in clinical practice compared with the machine learning method, the accuracy of fingerprint matching assay to identify five Salmonella serotypes reached 100.00% and the serotyping can be conducted within a short time (15-20 minutes) and had a good reproducibility, while the machine learning method could not completely identify these serotypes. Moreover the sensitivity and specificity of fingerprint matching assay were all 100.00% respectively, while they were only 82.23% and 95.81% for machine learning method. Conclusion:The established Salmonella serotyping assay based on MALDI-TOF MS in this study can easily, rapidly and accurately identify different serotypes of Salmonella.

Objective:To establish a pediatric visualized teaching network containing disease images and videos, and to investigate its application effect in assisting the integrated online-offline teaching of pediatric students.Methods:The medical students of classes 2014 and 2015 in the eight-year program who studied as an intern in Department of Pediatrics, Peking Union Medical College Hospital, were enrolled as subjects. The medical students of class 2014 before the application of the pediatric visualized teaching network in the integrated online-offline teaching of pediatrics were enrolled as control group ( n=75), and the medical students of class 2015 after the application of the network were enrolled as experimental group ( n=64). The two groups were compared in terms of the results of group interview and the scores of clinical competency self-assessment scale before and after teaching assisted by the pediatric visualized teaching network. SPSS 26.0 software was used to perform a statistical analysis, with a significance level of α=0.05. Results:During the interview, most students thought that the visualized teaching network improved their learning interest in pediatrics and reduced the emotion of fear of difficulties when they just entered the pediatric internship. They were more confident in operation, and there were also increases in the degree of participation and success rate of operation. There were significant differences between the control group and the experimental group in the scores of six dimensions of the clinical competency self-assessment scale, professional competence [(3.1±0.4) vs. (4.2±0.6), P<0.001], knowledge and skills [(3.7±0.9) vs. (4.2±0.8), P<0.001], patient care [(3.7±0.8) vs. (4.3±0.6), P<0.001], communication and cooperation [(3.7±0.4) vs. (4.2±0.7), P<0.001], teaching ability [(3.8±0.5) vs. (4.3±0.8), P<0.001], lifelong learning [(3.9±0.6) vs. (4.4±0.6), P<0.001]. Conclusions:The visualized teaching network promotes the transformation of offline teaching to integrated online-offline teaching and the optimization of clinical competency-oriented teaching system.

This study intends to establish a colorectal cancer(CRC)organoid model,expand and isolate CRC-reactive tumor-infiltrating lymphocytes(TILs),screen tumor-specific T cell receptors(TCRs)and perform functional verification,in order to provide a technological platform and research foundation for the clinical transformation of individualized adoptive T-cell immunotherapy for colorectal cancer.An organoid model derived from colon cancer patient tissues was constructed using in vitro 3D culture techniques,which then subjected to HE staining and immunohistochemistry for detecting morphological characteristics and representative molecular expression.Subsequently,CRC organoids were co-cultured with TILs for sorting reactive TILs using flow cytometry,and the characteristics of reactive TCR clones was analyzed through single T cell receptor gene cloning technology.Furthermore,the function of TCRs was verified through cytotoxicity experiments.Morphological analysis and representative molecules(CK20 and CDX2)expression indicated that there is high similarity between colorectal cancer organoids and patient tumors.In the in vitro expanded and cultured TILs,colorectal cancer-reactive T cells with upregulated CD137 expression and increased IFN-γ secretion were screened out successfully,among which TCR2-T cells demonstrated superior tumor reactivity and in vitro tumor killing function.In conclusion,a platform for screening and function validation of reactive TCRs based on CRC-Org has been established,providing a technological platform for the translational application of individualized T-cell therapy for colorectal cancer.