Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy. Approximately 50% to 60% of patients with OSCC are diagnosed at a locally advanced stage (clinical staging III-IVa). Even with comprehensive and sequential treatment primarily based on surgery, the 5-year overall survival rate remains below 50%, and patients often suffer from postoperative functional impairments such as difficulties with speaking and swallowing. Programmed death receptor-1 (PD-1) inhibitors are increasingly used in the neoadjuvant treatment of locally advanced OSCC and have shown encouraging efficacy. However, clinical practice still faces key challenges, including the definition of indications, optimization of combination regimens, and standards for efficacy evaluation. Based on the latest research advances worldwide and the clinical experience of the expert group, this expert consensus systematically evaluates the application of PD-1 inhibitors in the neoadjuvant treatment of locally advanced OSCC, covering combination strategies, treatment cycles and surgical timing, efficacy assessment, use of biomarkers, management of special populations and immune related adverse events, principles for immunotherapy rechallenge, and function preservation strategies. After multiple rounds of panel discussion and through anonymous voting using the Delphi method, the following consensus statements have been formulated: 1) Neoadjuvant therapy with PD-1 inhibitors can be used preoperatively in patients with locally advanced OSCC. The preferred regimen is a PD-1 inhibitor combined with platinum based chemotherapy, administered for 2-3 cycles. 2) During the efficacy evaluation of neoadjuvant therapy, radiographic assessment should follow the dual criteria of Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and immune RECIST (iRECIST). After surgery, systematic pathological evaluation of both the primary lesion and regional lymph nodes is required. For combination chemotherapy regimens, PD-L1 expression and combined positive score need not be used as mandatory inclusion or exclusion criteria. 3) For special populations such as the elderly (≥ 70 years), individuals with stable HIV viral load, and carriers of chronic HBV/HCV, PD-1 inhibitors may be used cautiously under the guidance of a multidisciplinary team (MDT), with close monitoring for adverse events. 4) For patients with a poor response to neoadjuvant therapy, continuation of the original treatment regimen is not recommended; the subsequent treatment plan should be adjusted promptly after MDT assessment. Organ transplant recipients and patients with active autoimmune diseases are not recommended to receive neoadjuvant PD-1 inhibitor therapy due to the high risk of immune related activation. Rechallenge is generally not advised for patients who have experienced high risk immune related adverse events such as immune mediated myocarditis, neurotoxicity, or pneumonitis. 5) For patients with a good pathological response, individualized de escalation surgery and function preservation strategies can be explored. This consensus aims to promote the standardized, safe, and precise application of neoadjuvant PD-1 inhibitor strategies in the management of locally advanced OSCC patients.

The functional realization of proteins and other biological macromolecules depends on conformational dynamics and allosteric regulation, and elucidating their molecular mechanisms is an important foundation for understanding life processes. Molecular dynamics simulations are a powerful tool for investigating conformational evolution at the atomic level. However, traditional methods are limited by simulation timescales and high free-energy barriers, making it difficult to effectively capture rare conformations and their transition pathways. As a result, the development of enhanced sampling techniques has become key to overcoming this bottleneck. As a classical enhanced sampling technique, metadynamics suffers from several shortcomings, including strong dependence on collective variables and significant errors caused by bias potential accumulation. This article reviews three major improvement strategies. The first combines stochastic resetting with metadynamics, using trajectory-resetting mechanisms to improve sampling efficiency while avoiding the difficulty of optimizing collective variables. The second, SinkMeta, employs a “sinking” bias effect to enable efficient exploration of specific regions and paths. The third, OPES-based hybrid methods, improve the stability of free-energy estimation by optimizing the target distribution or the way the bias is constructed. These methods provide new ideas for characterizing free-energy landscapes and studying conformational transitions in complex biological systems, while also promoting the continued development of enhanced sampling methodologies.

Objective:To explore the clinical characteristics, diagnosis and treatment strategies, and prognosis of pulmonary embolism (PE) complicating childhood rheumatic diseases.Methods:A retrospective case series study was performed on the demographic data, laboratory indicators, imaging features, treatment regimens, and follow-up data of 8 children with rheumatic diseases complicated by PE who were admitted to the Department of Rheumatology and Immunology, Capital Center for Children′s Health, Capital Medical University from January 2014 to October 2023.Results:Among the 8 children, there were 4 boys and 4 girls, with an age of 12.0 (7.5, 13.0) years. Among the primary diseases, there were 3 cases of systemic lupus erythematosus, 2 cases of Beh?et′s disease, 2 cases of Takayasu arteritis, and 1 case of antiphospholipid syndrome. All children developed PE during the active phase of the primary disease. PE was detected at the onset of the primary disease in 3 cases, and the median time from the diagnosis of the primary disease to the development of PE was 10.0 (6.0, 25.0) months in the remaining 5 cases. Fever was present in all 8 children, 4 cases were accompanied by chest tightness, dyspnea, etc., and 2 cases only presented with fever. Laboratory examinations revealed the following results: erythrocyte sedimentation rate was 42.0 (17.0, 78.0) mm/1 h, high-sensitivity C-reactive protein was 12.7 (2.6, 78.7) mg/L, white blood cell count was 9.6 (7.2, 18.7)×10 9/L; D-dimer was 2.3 (0.9, 6.2) mg/L; and hemoglobin was (109±16) g/L.Imaging examinations revealed that 5 cases had involvement of the bilateral lower pulmonary arteries, 5 cases had peripheral embolism, and 3 cases had central PE. Complications included 3 cases of deep vein thrombosis, 2 cases of intracranial venous sinus thrombosis, and 1 case of mild pulmonary hypertension.In terms of treatment, 7 cases received anticoagulation with heparin followed by warfarin. Immunomodulation was mainly based on glucocorticoids combined with immunosuppressants, and 4 cases were combined with biological agents. The follow-up time of 4.17 (1.75, 7.17) years, the time for complete absorption of PE was 10.5 (6.0, 18.0) months; all 8 children had no target events, with no recurrence or chronic thromboembolic pulmonary hypertension, and the pulmonary artery remodeling was good. Conclusions:PE complicating childhood rheumatic diseases is closely related to the activity of the primary disease. The clinical manifestations are insidious, with fever as the main symptom. Imaging examination is the key to diagnosis.Early adoption of heparin followed by warfarin anticoagulation and glucocorticoids combined with immunosuppressants and (or) biological agents to control the primary disease can achieve a favorable prognosis.

Objective:To explore the clinical characteristics, diagnosis and treatment strategies, and prognosis of pulmonary embolism (PE) complicating childhood rheumatic diseases.Methods:A retrospective case series study was performed on the demographic data, laboratory indicators, imaging features, treatment regimens, and follow-up data of 8 children with rheumatic diseases complicated by PE who were admitted to the Department of Rheumatology and Immunology, Capital Center for Children′s Health, Capital Medical University from January 2014 to October 2023.Results:Among the 8 children, there were 4 boys and 4 girls, with an age of 12.0 (7.5, 13.0) years. Among the primary diseases, there were 3 cases of systemic lupus erythematosus, 2 cases of Beh?et′s disease, 2 cases of Takayasu arteritis, and 1 case of antiphospholipid syndrome. All children developed PE during the active phase of the primary disease. PE was detected at the onset of the primary disease in 3 cases, and the median time from the diagnosis of the primary disease to the development of PE was 10.0 (6.0, 25.0) months in the remaining 5 cases. Fever was present in all 8 children, 4 cases were accompanied by chest tightness, dyspnea, etc., and 2 cases only presented with fever. Laboratory examinations revealed the following results: erythrocyte sedimentation rate was 42.0 (17.0, 78.0) mm/1 h, high-sensitivity C-reactive protein was 12.7 (2.6, 78.7) mg/L, white blood cell count was 9.6 (7.2, 18.7)×10 9/L; D-dimer was 2.3 (0.9, 6.2) mg/L; and hemoglobin was (109±16) g/L.Imaging examinations revealed that 5 cases had involvement of the bilateral lower pulmonary arteries, 5 cases had peripheral embolism, and 3 cases had central PE. Complications included 3 cases of deep vein thrombosis, 2 cases of intracranial venous sinus thrombosis, and 1 case of mild pulmonary hypertension.In terms of treatment, 7 cases received anticoagulation with heparin followed by warfarin. Immunomodulation was mainly based on glucocorticoids combined with immunosuppressants, and 4 cases were combined with biological agents. The follow-up time of 4.17 (1.75, 7.17) years, the time for complete absorption of PE was 10.5 (6.0, 18.0) months; all 8 children had no target events, with no recurrence or chronic thromboembolic pulmonary hypertension, and the pulmonary artery remodeling was good. Conclusions:PE complicating childhood rheumatic diseases is closely related to the activity of the primary disease. The clinical manifestations are insidious, with fever as the main symptom. Imaging examination is the key to diagnosis.Early adoption of heparin followed by warfarin anticoagulation and glucocorticoids combined with immunosuppressants and (or) biological agents to control the primary disease can achieve a favorable prognosis.

Quality control (QC) of biospecimens from oral and maxillofacial tumors patients constitutes a critical foundation for the prevention, diagnosis, treatment, and precision medicine research of these diseases. Biospecimen quality directly governs the discovery and validation of disease biomarkers, the elucidation of pathogenesis, and the efficacy of clinical translation. QC spans the entire biospecimen lifecycle—encompassing collection, processing, storage, transportation, and utilization. Its primary objectives are to ensure sample integrity, reliability, traceability, and consistency, thereby guaranteeing the robustness of research data; the accuracy of molecular subtyping, biomarker identification, and treatment response prediction; and the precision of clinical decision-making. However, current QC frameworks for these biospecimens remain underdeveloped. Drawing on domestic and international technical standards, regulatory guidelines, and recent research advances, this paper elaborates on the importance of implementing a QC management system throughout the biospecimen lifecycle. It focuses on QC methodologies tailored to diverse biospecimen types, examining how standardized sampling procedures, regulated preprocessing workflows, and optimized long-term storage conditions influence sample quality. We aim to provide concrete guidance and a transferable paradigm for establishing standardized QC protocols and an informatics-enabled traceability system specific to oral and maxillofacial tumors. Such efforts are intended to enhance the research value and clinical utility of these biospecimens, furnishing reliable sample resources and technical support for the development of precision diagnostics and therapeutics. Furthermore, we advocate for a dual-track “QC plus Ethics” management framework within biobanks. This approach would reinforce ethical and legal safeguards, establishing a robust barrier to support safe scientific innovation and clinical translation.

Objective: To explore the metabolic molecular mechanism of regulatory T cells (Tregs) resisting ferroptosis under a hypoxic stress microenvironment, and to provide scientific support for finding intervention targets to improve the immune microenvironment of oral squamous cell carcinoma (OSCC). Methods: This study was approved by the Institutional Medical Ethics Committee. Multiplex immunofluorescence was used to detect the distribution of Tregs and the localization of hypoxic regions in clinical pathological specimens from patients with OSCC tissues. Animal experiments were approved by the Laboratory Animal Ethics Committee. A tumor-bearing model was established in C57BL/6 mice. The submandibular, subscapular, inguinal, and popliteal lymph nodes were collected along with the spleen, and were homogenized to prepare single cell suspensions. C57BL/6 mouse naive CD4⁺ T cells were induced to differentiate into Tregs in vitro, and a 1% hypoxic culture model was established. Normoxia and hypoxia groups were established, and Treg viability under hypoxic conditions was assessed by flow cytometry. Transcriptomics and metabolomics were applied to analyze differentially expressed genes, metabolic pathways, and changes in cholesterol metabolites. Western blot was performed to detect the expression of emopamil-binding protein (EBP), glutathione peroxidase 4 (GPX4), ferroptosis suppressor protein 1 (FSP1), and acyl-CoA synthetase long-chain family member 4 (ACSL4). The safe concentration of the EBP inhibitor TASIN-30 was determined by the CCK-8 assay. On this basis, four groups were established: normoxia control, hypoxia, hypoxia+TASIN-30, and hypoxia+TASIN-30+7-dehydrocholesterol (7-DHC). Treg viability in each group was measured by flow cytometry; intracellular Fe2+ content, lipid peroxidation level, and reactive oxygen species (ROS) accumulation were detected by cellular immunofluorescence and flow cytometry; the reduced/oxidized glutathione (GSH/GSSG) ratio was measured using a microplate reader; and mitochondrial morphology was observed by transmission electron microscopy. In vivo tumor-inhibition experiments in C3H/HeJ mice were performed to validate the in vivo effects of EBP inhibition, and clinical prognostic survival analysis based on the TCGA-HNSC cohort was performed to evaluate the clinical prognostic value of ferroptosis resistance in Tregs. Results: Tregs were highly enriched in OSCC tissue, preferentially accumulated in hypoxic areas, and could maintain cell survival under hypoxia. The cholesterol metabolism pathway was upregulated in the hypoxic group, with increased EBP mRNA expression (P < 0.001) and 7-DHC accumulation. Compared with the hypoxic group alone, the hypoxic + TASIN-30 group showed decreased GPX4 and FSP1 expression (P < 0.001, P = 0.003); increased ACSL4 expression (P < 0.001); a decreased viable cell ratio (P < 0.001); increased Fe2+, lipid peroxidation, and ROS levels (P < 0.001); a decreased GSH/GSSG ratio (P < 0.001); and mitochondrial shrinkage. Exogenous supplementation of 7-DHC reversed the effects of EBP inhibition. In vivo inhibition of EBP significantly inhibited tumor growth (P < 0.001). Conclusion Tregs upregulate EBP and promote 7-DHC accumulation in hypoxic microenvironments, thereby inhibiting Treg ferroptosis and maintaining their survival and immunosuppressive function. Inhibition of EBP can weaken the resistance of Tregs to ferroptosis under hypoxia.

Glycosylation constitutes a critical, highly intricate, and diverse co- and post-translational modification characterized by the covalent attachment of sugar moieties to proteins, lipids, or small RNAs. Complex glycans are ubiquitously present across nearly all living organisms. Despite their prevalence, our comprehension of glycan diversity remains limited, likely due to the inherent challenges associated with elucidating their structural complexity. Among post-translational modifications, protein glycosylation is notably prevalent, involving the enzymatic transfer of oligosaccharides to specific amino acid residues by glycosyltransferases. This modification plays a pivotal role in modulating protein function, including participation in various biological and biochemical recognition processes. G protein-coupled receptors (GPCRs), encoded by approximately one thousand genes, share a conserved architecture comprising seven transmembrane helices interconnected by three intracellular and three extracellular loops. Representing the largest family of human membrane proteins, GPCRs regulate a vast array of physiological and pathological processes, thereby constituting the most extensive class of therapeutic targets. In mammalian systems, the majority of GPCRs undergo glycosylation predominantly at their extracellular N-terminus or extracellular loops, primarily through N-linked and O-linked glycosylation. These covalent carbohydrate modifications exert profound effects on multiple facets of GPCR biology, including endoplasmic reticulum folding and quality control, membrane trafficking and surface expression, receptor internalization and recycling or degradation, ligand binding and signal transduction, biased signaling, and receptor dimerization. Notably, glycosylation can exert both positive and negative regulatory influences on these processes. Dysregulation of GPCR glycosylation has been implicated in a range of pathological conditions, such as cancer, diabetes, and neurological disorders, underscoring its physiological and pathological significance. Aberrant glycosylation patterns may lead to dysfunctional receptor signaling, thereby contributing to disease progression. Consequently, elucidating the precise roles of glycosylation in GPCR function not only enhances fundamental understanding of receptor biology but also facilitates the development of novel therapeutic strategies targeting glycosylation pathways or specific GPCR glycoforms. Although the functional consequences of glycosylation have been investigated for several decades, delineating their exact structural underpinnings has remained challenging due to the intrinsic flexibility and heterogeneity of carbohydrate structures. Recent advances in structural biology, particularly single-particle cryo-electron microscopy (cryo-EM) and X-ray crystallography, have catalyzed a paradigm shift in our understanding of GPCR glycosylation. The integration of these sophisticated structural techniques with biochemical approaches has redefined glycosylation as a complex structural element integral to receptor function. These developments provide a molecular framework for comprehending how glycans influence receptor pharmacology and open new avenues for the rational design of glyco-engineered biologics and allosteric modulators targeting specific extracellular motifs. This mini-review concentrates on glycosylation within the GPCR superfamily, summarizing the impact of glycosylation modifications on receptor function and regulatory mechanisms, recent progress in the structural biology of GPCR glycosylation, and prospective directions for future research in this field.

Background Swimming is becoming increasingly popular for its combined leisure and fitness benefits. However, polluted swimming pool water may pose various health risks. Previous studies have indicated that health indicators of swimming venues have lower qualification rates compared to other public places, highlighting the urgent need to optimize hygiene management measures. Objective To assess the overall hygiene status and identify the key factors influencing water quality in Shanghai’s swimming venues from 2010 to 2024, and to provide a scientific basis for optimizing water quality management. Methods Water quality was assessed in three stages (2010—2019, 2020—2022, and 2023—2024) based on the monitoring data of Shanghai’s swimming venues (2010—2024). The influences of monitoring stage, region, season, scale, day of week, and per capita attendance on water quality were analyzed using chi-square tests and logistic regression. Results From 2010 to 2024, water quality was monitored in 1478 swimming venues. The compliance rates of turbidity, pH, urea, oxidation-reduction potential, free residual chlorine, combined residual chlorine, total bacteria, coliforms, and heat-resistant coliforms in swimming pool water, and free residual chlorine in the foot disinfection basin water samples were 99.56%, 94.73%, 73.00%, 47.50%, 56.55%, 54.12%, 97.74%, 99.49%, 99.90%, and 69.19%, respectively. The overall water quality compliance rate was 85.28%. The main non-compliant indicators for swimming pool water were urea, ORP, free residual chlorine, and combined residual chlorine, along with free chlorine residual in the foot disinfection basin water samples. Using the period before the implementation of the new national standard as reference, the results of logistic regression revealed that the qualification rates of urea, ORP, and free residual chlorine in the swimming pool water samples, as well as free residual chlorine in foot disinfection basin water samples, were significantly higher during the two phases after launching the new standard (2020–2022 and 2023–2024), and the associated odds ratios (95%CI) were 1.28 (1.00, 1.64) and 1.48 (1.12, 1.95), 13.35 (7.63, 23.37) and 10.78 (7.00, 16.60), 2.54 (1.81, 3.58) and 3.18 (2.41, 4.20), and 3.14 (2.14, 4.60) and 2.83 (1.89, 4.23), respectively. Compared with the reference group, those sampled in urban pools and in non-summer seasons showed higher qualification rates of urea and ORP; in contrast, the pools with high visitor flow showed lower qualification rates of free residual chlorine in both water samples of swimming pools and foot disinfection basins (P<0.05). Conclusion The implementation of the new national standard has effectively enhanced the management standards and significantly improved overall water quality of swimming venues in Shanghai. However, the compliance rates of free residual chlorine and urea in swimming pool water still need further improvement. The compliance of some indicators is influenced by region, season, scale, and average passenger flow, particularly in small suburban swimming venues. Future efforts should focus on refining water quality management strategies and enhancing public health management.

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, contact tracers were under immense pressure to deliver effective and timely contact tracing, raising concerns of higher susceptibility to burnout. Our study aimed to determine burnout prevalence among hospital-based contact tracers and associated risk factors, so that interventions to reduce burnout risk could be formulated. METHODS: One hundred and ninety-six active contact tracers across three hospitals within a healthcare cluster were invited to complete an anonymous online survey. To identify burntout, data such as demographics, work-related variables and contact tracing-related variables were collected using the Copenhagen Burnout Inventory. Associated factors were identified using multivariate statistics. Open-ended questions were included to understand the challenges and potential improvements through qualitative analysis. RESULTS: A total of 126 participants completed the survey, giving a completion rate of 64%, and almost half of these participants (42.9%) reported burnout. Protective factors included being on work-from-home arrangements (adjusted odds ratio [OR] 0.22, 95% confidence interval [CI] 0.08-0.56), perception of being well supported by their institution (adjusted OR 0.25, 95% CI 0.08-0.80) and being married (adjusted OR 0.28, 95% CI 0.12-0.64). Risk factors included having an administrative role pre-COVID-19 (adjusted OR 3.62, 95% CI 1.33-9.83). Work-related burnout was related to being activated for more than 1 day in the preceding week (unadjusted OR 3.25, 95% CI 1.33-7.94) and multiple activations in a day (unadjusted OR 3.54, 95% CI 1.44-4.41). Biggest challenges identified by participants were language barrier (62.7%), followed by workflow-related issues (42.1%). CONCLUSION Our study demonstrated burnout and other challenges faced by a team of mostly hospital-based administrative staff redeployed on a part-time basis to ensure timely contact tracing. To mitigate burnout, we recommend choosing staff on work-from-home arrangements and ensuring adequate manpower and rostering arrangements.
Humans ; COVID-19/epidemiology* ; Burnout, Professional/epidemiology* ; Singapore/epidemiology* ; Female ; Male ; Cross-Sectional Studies ; Adult ; Middle Aged ; Risk Factors ; Surveys and Questionnaires ; Contact Tracing/methods* ; SARS-CoV-2 ; Prevalence ; Pandemics

OBJECTIVE: To observe the effect of moxibustion on small intestinal mucosal immune barrier in rats with diarrhea-predominant irritable bowel syndrome (IBS-D) and explore its underlying mechanisms. METHODS: Of 38 newborn rats from 4 healthy SPF pregnant rats, 12 neonatal rats were randomly selected in a normal group. IBS-D model was prepared by the combined measures for the rest rats, including neonatal maternal separation, acetic acid enema and chronic restraint stress. Twenty-four successfully-modeled rats were randomized into a model group and a moxibustion group, 12 rats in each one. In the moxibustion group, suspending moxibustion was delivered at bilateral "Tianshu" (ST25) and "Shangjuxu" (ST37), 20 min each time, once daily and for 7 consecutive days. Separately, before acetic acid enema (aged 35 days), after modeling (aged 45 days) and after intervention (aged 53 days), the body mass, loose stool rate (LSR) and and the minimum volume threshold when abdominal withdrawal reflex (AWR) scored 3 were observed in the rats of each group. After intervention (aged 53 days), using HE and PAS staining, the morphology of duodenum was observed, the length of villus and the depth of crypt were measured, the ratio of the length of villus to the depth of crypt was calculated; and the numbers of mucosal intraepithelial lymphocytes (IELs) and goblet cells were counted. With ELISA adopted, the contents of γ-interferon (IFN-γ), interleukin-4 (IL-4) and secretory immunoglobulin A (sIgA) in duodenal mucosa of rats were detected. The proportion of T cell subsets in duodenal mucosa was detected using flow cytometry. The microvilli and tight junctions of duodenal mucosal epithelial cells were observed by transmission electron microscopy, and the integrity of duodenal mucosa observed by scanning electron microscopy. RESULTS: Compared with the normal group, for the rats in the model group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the the ratio of the length of villus to the depth of crypt, as well as the proportion of CD₈⁺ T subset were all reduced (P<0.01, P<0.05), the counts of goblet cells in duodenal mucosa decreased (P<0.01); LRS, the proportion of CD₄⁺ T subset and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were all elevated (P<0.01); and the numbers of IELs rose (P<0.01). The morphology of duodenal mucosa was irregular, the villi got shorter, sparse and scattered, with uneven density. The morphology of epithelial cells was destroyed and the tight junctions damaged, with larger spaces. When compared with the model group, in the moxibustion group, the body mass, the minimum volume threshold when AWR scored 3, the length of duodenal villus and the ratio of the length of villus to the depth of crypt, as well as the counts of goblet cells in duodenal mucosa increased (P<0.01); LRS, the proportion of CD₄⁺ T subset, and CD₄⁺/CD₈⁺, as well as the contents of IFN-γ, IL-4 and sIgA in duodenal mucosa and IFN-γ/IL-4 were reduced (P<0.01); and the numbers of IELs was dropped (P<0.01). The morphology of duodenal mucosa was more regular, the villi were grew, got longer and arranged regularly, with even density. The morphology of epithelial cells was slightly destroyed, and the tight junctions partially damaged. CONCLUSION Moxibustion at "Tianshu" (ST25) and "Shangjuxu" (ST37) can reduce visceral hypersensitivity in IBS-D rats and relieve abdominal pain, diarrhea and other symptoms. Its effect mechanism may be related to the repair of small intestinal mucosal immune barrier and the improvement in the immune function in IBS-D.
Animals ; Irritable Bowel Syndrome/immunology* ; Rats ; Moxibustion ; Intestinal Mucosa/immunology* ; Female ; Diarrhea/therapy* ; Intestine, Small/immunology* ; Male ; Humans ; Rats, Sprague-Dawley ; Disease Models, Animal