The construction of a training system for visiting physicians in the department of rare diseases in China is an important measure to improve the overall diagnosis and treatment capacity for rare diseases and address the critical challenge of insufficient knowledge and skills among clinicians in practice. This article systematically describes the visiting physician training system established by the Department of Rare Diseases at Peking Union Medical College Hospital. It summarizes the training objectives and positioning, design logic, and learning modules of the system, aiming to provide a reference for the construction of the specialized talent team for rare diseases in China.

To investigate the clinical efficacy of neoadjuvant imatinib in the treatment of rectal gastrointestinal stromal tumor (GIST).

A 51-year-old male presented with nasal obstruction, followed by progressive hearing loss and blurred vision. Imaging identified space-occupying lesions in the paranasal sinuses, orbits, and paraspinal regions, while laboratory tests confirmed positive anti-proteinase 3 anti-neutrophil cytoplasmic antibody(PR3- ANCA) immunoglobulin G (IgG)and markedly elevated serum IgG4. Despite treatment with corticosteroids, immunosuppressants, and radiotherapy, the patient exhibited steroid dependency with relentless disease progression. Following multidisciplinary consultation, a diagnosis of inflammatory myofibroblastic tumor (IMT) coexisting with ANCA- associated vasculitis (AAV) was favored, though IgG4-related disease remained a critical differential. Ultimately, profound immunosuppression precipitated a severe herpesvirus infection, leading to disseminated intravascular coagulation and multiple organ dysfunction syndrome. This case underscores the rarity and diagnostic complexity of concurrent IMT and AAV, highlights the therapeutic dilemma of balancing primary disease control against fatal opportunistic infections, and emphasizes the critical role of multidisciplinary collaboration in the diagnosis and treatment of complex diseases.

Gorham-Stout disease(GSD) is a rare osteolytic disorder characterized by spontaneous and progressive osteolysis, along with abnormal angiogenesis and lymphangiogenesis, with no new bone formation. We present a case of a 15-year-old female admitted due to " recurrent right leg pain for 5 years, 11 months after undergoing right femoral fracture surgery". Through comprehensive integration of the patient's clinical phenotype, laboratory tests, imaging findings, pathological examinations, and molecular biological test results, GSD was considered highly likely. A multidisciplinary treatment approach was conducted, including a combination of zoledronic acid and sirolimus to inhibit osteolysis, along with rehabilitation training and orthopedic intervention, providing a personalized and comprehensive treatment strategy.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an adult-onset, X-linked clonal autoinflammatory disease caused by somatic mutations in the UBA1 gene, characterized by systemic inflammation accompanied by hematologic clonal abnormalities. Somatic UBA1 mutations result in impaired ubiquitination, disruption of protein homeostasis, and sustained activation of inflammatory signaling pathways, including nuclear factor-κB and Janus kinase-signal transducer and activator of transcription (JAK-STAT), which together constitute the core pathogenic mechanism. The disease involves multiple systems and tissues including the hematologic system, skin, cartilage and respiratory system, showing remarkable clinical heterogeneity. Diagnosis depends primarily on the combination of characteristic clinical manifestations and molecular confirmation of UBA1 mutations. Current therapeutic strategies lack a unified standard: glucocorticoids can rapidly control inflammation but are associated with high relapse rates, whereas targeted therapies such as JAK inhibitors, interleukin inhibitors, and hypomethylating agents show variable efficacy, and allogeneic hematopoietic stem cell transplantation offers curative potential in patients with concomitant myelodysplastic syndrome. This review systematically summarizes the genetic background, molecular mechanisms, clinical spectrum, diagnostic criteria, and therapeutic advances of VEXAS syndrome.

The therapeutic effect of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with intestinal probiotics on the wound healing of diabetic mice and its potential mechanism were explored. A diabetic wound mouse model was established, and 25 male C57BL/6J mice were randomly divided into five groups: blank control group, model group, hUCMSCs treatment group, probiotics treatment group, and hUCMSCs combined with probiotics treatment group. The wound healing conditions were photographed and recorded on days 0, 3, 6, 9, and 12 after modeling, and the differences in wound healing rates among the groups were analyzed. HE and Masson staining were used to observe the histopathological changes and collagen deposition. CD31 immunofluorescence was used to detect angiogenesis. Collagen I immunohistochemistry was used to evaluate the formation of type I collagen. ELISA was used to detect the expression levels of anti-inflammatory factors (Arg1) and pro-inflammatory factors (IL-6, IL-1β, TNF-α) in wounded skin tissue and serum. The results showed that on day 12 after modeling, compared with the other groups, the combined treatment group had the most significant wound contraction and the fastest healing rate. HE and Masson staining showed that the combined treatment group had the fastest epithelialization and the most collagen deposition. Immunofluorescence and immunohistochemistry showed that the combined treatment group had the highest expression levels of CD31 and Collagen I. ELISA results indicated that the combined treatment group had higher expression levels of Arg1 in wound skin tissue and serum than the other groups, while the expression levels of IL-6, IL-1β, and TNF-α were significantly lower. These results suggest that the combined treatment of hUCMSCs and intestinal probiotics can accelerate wound healing in diabetic mice through mechanisms such as promoting angiogenesis, enhancing collagen deposition, and regulating the inflammatory microenvironment. The therapeutic effect was significantly better than that of single treatment, providing a new potential strategy for the clinical treatment of diabetic foot.

ObjectiveTo investigate the effects of metformin on the immune functions of immature dendritic cells （imDCs） and the underlying mechanisms. MethodsMouse bone marrow-derived imDCs were treated with different concentrations of metformin. The working concentration and treatment time of metformin in this study were determined based on the results of cell apoptosis and cell viability assays. The effects of metformin on the phagocytic capacity of imDCs was evaluated using an antigen endocytosis assay. The expression of cluster of differentiation 205 （CD205）， the polymerization of filamentous actin （F-actin）， and the underlying regulatory mechanisms were investigated through flow cytometry， laser confocal fluorescence microscopy， and Western blot. ResultsThe working concentrations of metformin were 1， 2， 4 mmol/L for 24 h determined by the apoptosis and cell viability assays.Metformin significantly suppressed the phagocytic capacity of imDCs， down-regulated the expression of the mannose receptor CD205 on the cell surface， which was closely associated with phagocytic function； metformin inhibited the RhoA-ROCK1-LIMK1-Cofilin signaling pathway， which inhibited the polymerization of F-actin and disturbed its dynamic remodeling of imDCs. ConclusionMetformin can inhibit the expression of CD205 and disrupt the remodeling of F-actin， thereby suppressing the antigen-capturing capacity of imDCs.

ObjectiveTo retrospectively analyze the correlation among serotypes, antimicrobial resistance phenotypes, and resistance genotypes of Salmonella isolates from diarrheal cases in Baoshan District of Shanghai from 2023 to 2024, and to provide a reference for the prevention and control of Salmonella infections and the rational use of antibiotics in clinical practice. MethodsSalmonella isolates collected from diarrheal cases under surveillance in Baoshan District from 2023 to 2024 were serotyped. Antimicrobial resistance phenotypes were determined using the broth microdilution method, and whole-genome sequencing was performed to identify resistance genes. Positive predictive value and Kappa were calculated to evaluate the agreement between phenotypic and genotypic resistance profiles of Salmonella. ResultsA total of 64 Salmonella isolates belonged to 17 serotypes, with the predominant ones being Salmonella Typhimurium (25.00%) and Salmonella Enteritidis (18.75%). The tested strains exhibited high resistance rates to ampicillin (60.94%), streptomycin (59.38%), and ampicillin/sulbactam (45.31%). All isolates remained susceptible to ceftiofur and ceftazidime/avibactam. Forty different resistance profiles were identified, and 39 isolates accounting for 60.94%, were multidrug-resistant. Overall, 80 resistance genes belonging to 13 categories were detected, with the most prevalent being bla_TEM-1 (57.81%), aac(6')⁃Iy (54.69%), and aph(6)⁃Id (46.88%). No carbapenem or polymyxin resistance genes were found. The types and numbers of resistance genes varied significantly across serotypes. A high concordance was observed between genotype and phenotype for penicillins (positive predictive value: 94.59%, Kappa: 0.81), cephalosporins (90.91%, 0.46), cephamycins (100.00%, 0.65), macrolides (77.78%, 0.86), tetracyclines (100.00%, 0.93), and chloramphenicol (95.83%, 0.93). ConclusionSalmonella isolates from diarrheal diseases in Baoshan District exhibit high antimicrobial resistance. Whole-genome sequencing provides valuable support for resistance surveillance, however, it still needs to be integrated with phenotypic susceptibility testing for comprehensive assessment. Further studies are warranted to elucidate the mechanisms and transmission patterns of resistance in Salmonella.

ObjectiveTo explore the molecular mechanism of aerobic exercise to improve hippocampal neuronal degeneration by regulating tryptophan metabolic pathway. Methods60 SPF-grade C57BL/6J male mice were divided into a young group (2 months old, n=30) and a senile group (12 months old, n=30), and each group was further divided into a control group (C/A group, n=15) and an exercise group (CE/AE group, n=15). An aerobic exercise program was used for 8 weeks. Learning memory ability was assessed by Y-maze, and anxiety-depression-like behavior was detected by absent field experiment. Hippocampal Trp levels were measured by GC-MS. Nissl staining was used to observe the number and morphology of hippocampal neurons, and electron microscopy was used to detect synaptic ultrastructure. ELISA was used to detect the levels of hippocampal Trp,5-HT, Kyn, KATs, KYNA, KMO, and QUIN; Western blot was used to analyze the activities of TPH2, IDO1, and TDO enzymes. ResultsGroup A mice showed significant decrease in learning and memory ability (P<0.05) and increase in anxiety and depressive behaviors (P<0.05); all of AE group showed significant improvement (P<0.05). Hippocampal Trp levels decreased in group A (P<0.05) and increased in AE group (P<0.05). Nidus vesicles were reduced and synaptic structures were degraded in group A (P<0.05), and both were significantly improved in group AE (P<0.05). The levels of Trp, 5-HT, KATs, and KYNA were decreased (P<0.05) and the levels of Kyn, KMO, and QUIN were increased (P<0.05) in group A. The activity of TPH2 was decreased (P<0.05), and the activities of IDO1 and TDO were increased (P<0.05). The AE group showed the opposite trend. ConclusionThe aging process significantly reduces the learning memory ability and increases the anxiety-depression-like behavior of mice, and leads to the reduction of the number of nidus vesicles and degenerative changes of synaptic structure in the hippocampus, whereas aerobic exercise not only effectively enhances the spatial learning memory ability and alleviates the anxiety-depression-like behavior of aging mice, but also improves the morphology and structure of neurons in hippocampal area, which may be achieved by the mechanism of regulating the tryptophan metabolic pathway.

BackgroundMigrant children face many challenges in the process of social change and adaptation to a new environment， especially in school adaptation. Studies have shown that peer attachment plays a vital role in the social adaptation of children and adolescents， while psychological resilience and sense of security， as important psychological resources， also play a moderating and mediating role in individuals' coping with environmental changes. However， there is a lack of systematic research on how peer attachment affects the school adaptation of migrant children through psychological resilience and whether this process is moderated by sense of security. ObjectiveTo explore the relationship between peer attachment and school adaptation of migrant children and to examine the path of psychological resilience and sense of security in it， so as to provide references for improving the school adaptation of migrant children. MethodsUsing cluster sampling method， 695 migrant children in grades 4 to 6 of a primary school in an urban-rural fringe area of Sichuan Province were selected from April 1 to 30， 2022. Assessments were conducted using Revised Inventory for Parent and Peer Attachment （IPPA-R）， Resilience Scale for Chinese Adolescents （RSCA）， Scale of Sense of Security of Children Left Behind （SSSCLB） and Scale of School Adjustment of Student （SSAS）. Process 4.1 was used to examine the role of psychological resilience and sense of security. ResultsA total of 631 （90.79%） valid questionnaires were gathered. There were significant positive correlations among IPPA-R peer attachment subscale score， RSCA score， SSSCLB score and SSAS score （r=0.160~0.600， P<0.01）. Peer attachment had a significant positive predictive effect on the school adaptation （β=0.178， P<0.01） and psychological resilience （β=0.518， P<0.01） of migrant children. Psychological resilience had positive predictive effect on the school adaptation （β=0.467， P<0.01）. Psychological resilience played a partial mediating role in the relationship between peer attachment and school adaptation， with the mediating effect value was 0.242 （95% CI： 0.184~0.302）， accounting for 57.62% of the total effect. Moreover， the interaction term between psychological resilience and sense of security had a significant predictive effect on school adaptation （β=0.103， P<0.01）. ConclusionThe psychological resilience of migrant children plays a partial mediating role in the relationship between peer attachment and school adaptation， and the status of sense of security can moderate the relationship between psychological resilience and school adaptation of migrant children.