Jin-Jun Chen

Humanized mouse models offer human-specific platforms for investigating complex host–pathogen interactions, addressing shortcomings of conventional preclinical models that often fail to replicate human immune responses accurately. This integrative review examines the intersection of advanced morphological phenotyping and artificial intelligence (AI) to enhance predictive capacity and translational relevance in infectious disease research. A structured literature search was conducted across PubMed, Scopus, and Web of Science (2010–2025), applying defined inclusion and exclusion criteria. Evidence synthesis highlights imaging modalities, AI-driven phenotyping, and standardization strategies, supported by comparative analyses and quality considerations. Persistent challenges include variability in engraftment, lack of harmonized scoring systems, and ethical governance. We propose recommendations for standardized protocols, risk-of-bias mitigation, and collaborative training frameworks to accelerate adoption of these technologies in translational medicine.

MPs are pervasive pollutants in marine ecosystems, posing risks to aquatic organisms due to their small size and bioaccumulation potential. This study investigated the intestinal toxicity of MP particles extracted from mangrove sediments in zebrafish, comparing the effects before and after microbial degradation. Zebrafish were exposed to either undegraded MPs or microbially degraded MP extracts at concentrations of 0 (control), 2, 10, and 50 mg/L for 21 days in 10 L tanks (stocking density: 10 fish/L), with three replicate tanks per concentration. MPs were dispersed ultrasonically before addition to the water. Intestinal samples were collected on 7, 14, and 21 days for the analysis of immune response (tumor necrosis factor-alpha, TNF-α; interleukin-1 beta, IL-1β; interleukin-6, IL-6; interleukin-8, IL-8) and antioxidant activity (superoxide dismutase, SOD; catalase, CAT). Histopathological analysis revealed intestinal wall thinning, villus damage, and epithelial cell detachment in zebrafish exposed to both undegraded and degraded MP extracts; however, undegraded MPs induced more severe intestinal damage. Results indicated dynamic changes in cytokine expression: TNF-α decreased initially before increasing, while IL-1β and IL-8 first rose then declined. IL-6 peaked on day 7, dropped by day 14, and increased again on day 21. CAT expression decreased, whereas SOD increased only in the pre-degradation group. Microbial degradation reduced intestinal damage severity, with effects intensifying at higher MP exposure levels. These findings demonstrate that MPs can impair zebrafish digestive systems, but microbial degradation mitigates their toxicity. This study underscores the importance of biodegradation as a potential environmental remediation strategy and provides experimental evidence on MPs’ impact on aquatic organisms.

The rabbit industry urgently needs natural alternatives to maintain gut health. This need is growing due to the higher incidence of intestinal problems in antibiotic-free production systems. Pfaffia glomerata (Brazilian ginseng) is a medicinal plant rich in bioactive compounds. This study evaluated the effects of dietary inclusion of P. glomerata leaf powder on growth performance, immune function, and gut microbiota in New Zealand rabbits. A total of 100 New Zealand rabbits (35 days old) were randomly assigned to five groups (n = 20 each). The groups comprised a blank control group (CON), an immunosuppressed group (CTX), and three treatment groups receiving low (L), medium (M), and high (H) doses of P. glomerata leaf powder at 0.5%, 1%, and 2% of the basal diet, respectively. Growth performance was assessed by average daily gain (ADG). Intestinal morphology was evaluated by measuring villus height and crypt depth in the duodenum, jejunum, and ileum. Immune parameters included thymus and spleen weight, serum immunoglobulin levels, and leukocyte counts. Cecal microbiota diversity and composition were analyzed. Compared to CON, Pfaffia supplementation improved growth performance: the L and H groups had significantly higher ADG and a lower feed conversion ratio (p < 0.05). In intestinal histology, groups L and M had reduced crypt depth in the duodenum (p < 0.05), and group L had an increased villus height to crypt depth ratio. In the jejunum and ileum, groups L and H exhibited increased villus height and villus height to crypt depth ratio (p < 0.05), indicating an enhanced absorptive surface. In the immunosuppressed model, rabbits in all Pfaffia groups showed significantly increased thymus and spleen weight compared to the CTX group (p < 0.05) and demonstrated elevated serum immunoglobulins and leukocyte counts (monocytes, lymphocytes, and neutrophils) (p < 0.05). Pfaffia supplementation also enhanced cecal microbiota diversity and increased the abundance of beneficial bacteria. In summary, dietary P. glomerata leaf powder enhanced growth performance, immune organ development, and healthy gut microbiota in growing rabbits. The 0.5% supplementation level (L group) yielded the most consistent benefits. These results suggest that P. glomerata is a promising natural feed additive to promote rabbit health and production in antibiotic-free systems.

The health and productivity of cattle are significantly compromised by metabolic diseases on a global scale. These disorders disrupt normal metabolic processes, leading to substantial economic losses for the livestock industry. Metabolic disorders can arise from defective biochemical pathways, deficiencies in enzymes, coenzymes, or cofactors, and may be either inherited or acquired. Dairy cows are particularly susceptible during the transition period from late lactation to early management, facing conditions such as ketosis, milk fever, and hepatic lipidosis. This susceptibility is primarily due to reduced dry matter intake caused by fetal development and a decline in rumen capacity. The negative energy balance (NEB) during this phase, characterized by elevated blood concentrations of non-esterified fatty acids (NEFAs) due to increased energy mobilization, is closely linked to the onset of these diseases. Providing high-energy-density diets during this period is critical to mitigating the effects of NEB. Metabolic disorders represent a major health challenge in cattle, adversely affecting animal welfare and agricultural output. A comprehensive understanding of their etiology, clinical manifestations, diagnostic approaches, and management strategies is essential for effective prevention and treatment. Ongoing research and the adoption of preventive measures are vital to reducing the economic and health impacts of these diseases. Early diagnosis and proactive management strategies are crucial to mitigating their impact on dairy cattle health and productivity. Early identification enables timely interventions, preventing disease progression and reducing adverse effects on animal health. Proactive measures, such as optimizing nutritional programs, implementing precision farming technologies, and ensuring timely veterinary care, are essential for enhancing the overall wellbeing of dairy cows. This review serves as a valuable resource for veterinarians, researchers, and dairy farmers, offering in-depth insights into the etiology, clinical signs, diagnostics, and management of prevalent metabolic disorders in dairy cattle. By equipping stakeholders with this knowledge, it aims to support informed decision-making and improve herd management practices. The focus on early diagnosis and proactive strategies underscores the potential to significantly reduce the economic and health burdens imposed by metabolic diseases on the livestock industry.

The pervasive use of plastics in numerous industrial sectors has resulted in the circulation of microplastics across diverse ecosystems and food chains, giving rise to mounting concerns regarding their potential adverse impacts on biological systems and the environment. The objective of this experiment was to investigate the distinct effects of microplastic-polyvinyl chloride (PVC) exposure on the reproductive system, intestinal tissue structure, and intestinal microbial flora of both male and female mice. A total of 24 4-week-old Kunming mice were randomly assigned to one of four groups: male control group (CM), female control group (CF), male PVC test group (PVCM), and female PVC test group (PVCF) (n = 6). The findings revealed that in terms of the reproductive system, the PVCM group exhibited an impaired testicular structure with an irregular arrangement and a significant reduction in spermatogonia, spermatocytes, and spermatozoa within the seminiferous tubules (p < 0.01). The PVCF group exhibited a notable decrease in ovarian follicles (p < 0.01), accompanied by a reduction in uterus volume, fallopian tube volume, and muscle layer thickness, all of which also decreased significantly (p < 0.01). In comparison to the control groups, exposure to PVC resulted in a reduction in the width and height of the intestinal villi, accompanied by an increase in crypt depth. This led to a significant alteration in the ratio of villus height to crypt depth (V/C) (p < 0.01). Moreover, a reduction in microbial species diversity was observed within both the PVCM and PVCF groups; additionally, it was accompanied by contrasting changes in relative abundance and functional gene profiles among the major intestinal flora constituents. In summary, the findings indicate that PVC induces damage to both male and female mice reproductive and digestive systems, further exhibiting notable sex-dependent effects on mouse intestinal microflora composition, which correlates significantly with its impact on reproductive organs.

Polychlorinated biphenyls (PCBs) are lipophilic environmental toxicants. Epidemiological studies have established a link between PCBs and both metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). Multiple studies have reported that exposure to both PCB156 and PCB126 among the 12 dioxin-like PCBs leads to the development of NAFLD. However, studies to elucidate whether PCB169 induces the development of NAFLD by constructing in vivo models have not been reported. Therefore, we evaluated the effects of exposure to PCB169 (5 mg/kg-bw) on hepatic lipid metabolism in C57BL/6 mice from control diet and high-fat diet cohorts. The results showed that PCB169 exposure reduced body weight and intraperitoneal fat mass in mice on the control diet, but the liver lipid levels were significantly increased, exacerbating NAFLD in mice on a high-fat diet. Through transcriptomics studies, it was found that PCB169 exposure induced significant up-regulation of Pparγ, Fasn, and Aacs genes involved in hepatic lipogenesis, as well as remarkable up-regulation of Hmgcr, Lss, and Sqle genes involved in cholesterol synthesis. Additionally, there was notable down-regulation of Pparα and Cpt1 genes involved in lipid β-oxidation, leading to abnormal lipid accumulation in the liver. In addition, we found that PCB169 exposure significantly activated the Arachidonic acid metabolism, PPAR signaling pathway, Metabolism of xenobiotics by cytochrome P450, and Retinol metabolism pathways, and so on. Our study suggests that PCB169 can modify gene expression related to lipid metabolism, augument lipid accumulation in the liver, and further contribute to the development of NAFLD, thereby revealing the detrimental effects associated with PCB exposure on animal growth and metabolism.

Rhodotorula mucilaginosa (R. mucilaginosa) can enhance the immune and antioxidant function of the body. However, whether R. mucilaginosa has an immunoregulatory effect on cyclophosphamide (CTX)-induced immunosuppressed animals remains to be clarified. In this study, the R. mucilaginosa ZTHY2 that we isolated from the coastal waters of the South China Sea previously was prepared in order to investigate its immunoprotective effect on CTX-induced immunosuppression in mice, and the effects were compared to those of Lactobacillus acidophilus (LA) (a well-known probiotic). Seventy-two male SPF mice were divided into six groups: The C group (control); IM group (immunosuppressive model group) (+CTX); Rl, Rm, and Rh groups (+CTX+low, medium, and high concentration of R. mucilaginosa, respectively); and PC (positive control) group (+CTX+LA). After a 28-day feeding trial, blood samples were taken for biochemical and serum immunological analysis, and the thymus and spleen were collected to analyze the organ index, lymphocyte proliferation and differentiation, and antioxidant capacity. The findings showed that R. mucilaginosa ZTHY2 improved the spleen and thymus indices, effectively attenuated immune organ atrophy caused by CTX, and enhanced the proliferation of T and B lymphocytes induced by ConA and LPS. R. mucilaginosa ZTHY2 promoted the secretion of cytokines and immunoglobulins and significantly increased the contents of IL-2, IL-4, IL-6, TNF-α, IFN-γ, IgA, IgG, IgM, CD4, CD8, CD19, and CD20 in serum. The proportion of CD4⁺, CD8⁺, CD19⁺, and CD20⁺ lymphocytes in spleen, thymus, and mesenteric lymph nodes were increased. In addition, R. mucilaginosa ZTHY2 reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) levels and increased glutathione (GSH), total superoxide dismutase (SOD), and catalase (CAT) levels. Our results indicated that R. mucilaginosa ZTHY2 can significantly enhance the immune function of immunosuppressed mice, and improving antioxidant capacity thus attenuates CTX-induced immunosuppression and immune organ atrophy.