OBJECTIVES: As early as the Apollo 11 mission, astronauts experienced ocular, skin, and upper airway irritation after lunar dust (LD) was brought into the return cabin, drawing attention to its potential biological toxicity. However, the biological effects of LD exposure through the digestive system remain poorly understood. This study aimed to evaluate the impact of digestive exposure to lunar dust simulant (LDS) on gut microbiota and on the intestine, liver, kidney, lung, and bone in mice. METHODS: Eight-week-old female C57BL/6J mice were used. LDS was used as a substitute for lunar dust, and Shaanxi loess was used as Earth dust (ED). Mice were randomly divided into a phosphate buffered saline (PBS) group, an ED group (500 mg/kg), and a LDS group (500 mg/kg), with assessments at days 7, 14, and 28. Mice were gavaged once every 3 days, with body weight recorded before each gavage. At sacrifice, fecal samples were analyzed by 16S ribosomal RNA (rRNA) sequencing; inflammatory cytokine expression [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] in intestinal, liver, and lung tissues was measured by real-time reverse transcription PCR (real-time RT-PCR); hematoxylin and eosin (HE) staining was performed on lung, liver, and intestinal tissues; Periodic acid-Schiff (PAS) staining was used to assess the integrity of the intestinal mucus barrier, and immunohistochemical staining was performed to evaluate the expression of mucin-2 (MUC2). Serum biochemical tests assessed hepatic and renal function. Femoral bone mass was analyzed by micro-computed tomography (micro-CT); osteoblasts and osteoclasts were assessed by osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) staining. Bone marrow immune cell subsets were analyzed by flow cytometry. RESULTS: At day 10, weight gain was slowed in ED and LDS groups. At days 22 and 28, body weight in both ED and LDS groups was significantly lower than controls (both P<0.05). LDS exposure increased microbial species richness and diversity at day 7. Compared with the PBS and ED groups, mice in the LDS group showed increased relative abundance of Deferribacterota, Desulfobacterota, and Campylobacterota, and decreased Firmicutes, with increased Helicobacter typhlonius and reduced Lactobacillus johnsonii and Lactobacillusmurinus. HE and PAS staining of the colon showed that mucosal structural disruption and goblet cell loss were more severe in the LDS group. In addition, immunohistochemistry revealed a significant downregulation of MUC2 expression in this group (P<0.05). No obvious pathological alterations were observed in liver HE staining among the 3 groups, and none of the groups exhibited notable hepatic or renal dysfunction. HE staining of the lungs in the ED and LDS groups showed increased perivascular inflammatory cell infiltration (both P<0.05). CONCLUSIONS LDS exposure via the digestive route induces gut dysbiosis, intestinal barrier disruption, pulmonary inflammation, bone loss, and bone marrow immune imbalance. These findings indicate that LD exposure poses potential health risks during future lunar missions. Targeted restoration of beneficial gut microbiota may represent a promising strategy to mitigate LD-related health hazards.
Animals ; Dust ; Mice ; Mice, Inbred C57BL ; Dysbiosis/etiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Moon ; Liver/metabolism* ; Digestive System/microbiology* ; Lung/metabolism* ; Kidney

OBJECTIVES: Due to prolonged exposure to cosmic radiation and meteorite impacts, lunar surface dust forms nanoscale angular particles with strong electrostatic adsorption properties. These dust particles pose potential inhalation risks, yet their pulmonary toxicological mechanisms remain unclear. Given the need for dust exposure protection in future lunar base construction and resource development, this study established an acute exposure model using lunar soil simulant (LSS) and used Earth soil (ES; Loess from Shaanxi, China) as a comparison to investigate lung injury mechanisms. METHODS: C57BL/6 mice were randomly assigned to 3 groups: Phosphate buffered saline (PBS), LSS, and ES, with 5 to 7 mice per group. Mice in the LSS and ES groups received a single intratracheal instillation to induce acute inhalation exposure. Body weight was monitored for 28 days. Mice were euthanized at days 3, 7, 14, and 28 post-exposure, and peripheral blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. Immune cell subsets in BALF were analyzed using flow cytometry. Hematoxylin-eosin (HE) staining assessed lung structure and inflammation; periodic acid-Schiff (PAS) staining evaluated airway mucus secretion; Masson staining examined collagen deposition. Real-time reverse transcription PCR (real-time RT-PCR) was used to measure the mRNA expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and epithelial barrier genes (Occludin, Cadherin-1, and Zo-1). Lung tissues at day 7 were subjected to transcriptomic sequencing, followed by immune infiltration and pathway enrichment analyses to determine immunoregulatory mechanisms. RESULTS: Body weight in the ES group progressively declined after day 18 (all P<0.05), while the LSS group showed no significant changes compared with the control group. HE staining showed both LSS and ES induced inflammatory cell infiltration around airways and vasculature, which persisted for 28 days but gradually lessened over time. PAS staining revealed marked mucus hypersecretion in the LSS group at day 3, followed by gradual recovery; no significant mucus changes were observed in the ES group. Masson staining indicated no obvious pulmonary fibrosis in either group within 28 days. Real-time RT-PCR demonstrated significant upregulation of IL-1β and TNF-α in both LSS and ES groups, peaking on day 7, accompanied by downregulation of epithelial barrier genes (Occludin, Cadherin-1, and Zo-1)(all P<0.05). Transcriptomic analysis showed that both LSS and ES activated chemokine-related pathways and enriched leukocyte migration and neutrophil recruitment pathways. Further validation revealed upregulation of CXCL2 and MMP12 in the LSS group, whereas CXCL3 and MMP12 were predominantly elevated in the ES group. CONCLUSIONS Both LSS and ES can induce sustained lung injury and neutrophil infiltration in mice, though the underlying molecular mechanisms differ. Compared with ES, exposure to LSS additionally triggers a transient eosinophilic response, suggesting that lunar dust particles possess stronger immunostimulatory potential and higher biological toxicity.
Animals ; Mice ; Mice, Inbred C57BL ; Soil ; Lung Injury/etiology* ; Dust ; Bronchoalveolar Lavage Fluid ; Moon ; Lung/pathology* ; Inhalation Exposure/adverse effects* ; Male

Objective:To evaluate the risk factors of clinical cure and biochemical recurrence (BCR) after radical prostatectomy (RP).Methods:The clinical data of 896 patients who underwent RP at Peking University First Hospital from April 2001 to December 2020 were retrospectively analyzed. Average age was (65.90±6.3) years, median preoperative prostate specific antigen (PSA) was 10.75 (0.36-264.20) ng/ml, median prostate volume was 40.0 (12.0-220.9) ml, median PSA density (PSAD) was 0.27 (0.02-3.42) ng/(ml·g). Clinical staging: 432 cases in T 1c stage, 333 cases in T 2a/bstage, 76 cases in T 2c stage, and 55 cases in ≥T 3 stage. Preoperative Gleason score of biopsy: 193 cases in 3+ 3, 315 cases in 3+ 4, 162 cases in 4+ 3, 226 cases in ≥8. The RP surgery was operated by open or laparoscopic or robot-assisted approach. Clinical cure and BCR were used as the end points for analysis. Clinical cure was defined as a decrease in serum PSA level below 0.03 ng/ml 6 weeks after surgery. BCR was defined as the 2 consecutive serum PSA >0.2ng/ml during the follow-up after RP. Multivariate logistic regression was used to analyze the independent risk factors of clinical cure. The Kaplan-Meier method was used to draw the biochemical recurrence-free survival curve, the log-rank method was used for univariate analysis of BCR, and the Cox regression analysis was used for multivariate analysis. Results:All 896 patients were followed-up for 58 (5-241) months, 678 cases (75.7%) achieved clinical cure. Based on univariate analysis and multivariate analysis, among the preoperative indicators, whether the proportion of positive biopsy needles ≥33% ( P=0.007) and preoperative Gleason score of biopsy ( P=0.041) were independent risk factors of clinical cure. A total of 890 cases were included in the analysis of risk factors of BCR, of whom 172 cases (19.3%) had BCR. The 1-, 5-, and 10-year biochemical recurrence-free survival(BFS)rates were 98.1%, 83.1% and 68.4% respectively. The median BFS has not been reached, and the average BFS was 181 months (95% CI 172-189). The results of univariate and multivariate analysis showed that whether achieved clinical cure ( P=0.001) and postoperative pathological staging ( P<0.001) were independent risk factors of BCR. Conclusions:Whether the proportion of positive biopsy needles≥33% and preoperative Gleason score of biopsy were independent risk factors of clinical cure. Postoperative pathological staging and whether achieved clinical cure may be independent risk factors of BCR.

Objective:To evaluate the rationality of the "Sandwich Principle teaching mode" adopted in our teaching of internal medicine and verify the necessity of its "Intergroup intersecting discussion".Methods:33 students majoring in traditional Chinese medicine were divided into control group (taught by standard process of sandwich principle) and experiment group (taught by simplified process of sandwich principle). The Dundee Ready Education Environment Measure (DREEM) was used to evaluate students' feelings toward the two teaching modes.Results:The total score of DREEM in the control group was higher than that in the experiment group, with statistically significant difference; the total score in the academic perception subscale in the control group was higher than that in the experiment group, among which the scores of "I have faith in passing the exam this year" and other 2 items were better than that in the experiment group, with statistically significant difference ( P<0.05); there were no statistical difference in the total scores of other perception subscales between the two groups( P>0.05), but the scores of the 9 items including "the atmosphere is very harmonious in the clinical teaching process" in the control group were significantly better than those in the experiment group, with statistically significant difference( P<0.05). Conclusion:The teaching mode of Sandwich Principle can create a positive and effective learning environment for supporting students. "Intergroup intersecting discussion" can encourage students to actively participate in the teaching process, and help increase their academic confidence and sense of achievement in learning. It is also helpful to build a harmonious teacher-student relationship and create a relaxing and pleasant learning environment so that students can gain a better learning experience. Therefore, "Intergroup intersecting discussion" is indispensable in medical teaching.

MicroRNA-125b (miR-125b) has been proved to be closely related to a variety of cancers in recent years, such as lung cancer, digestive system cancers, blood cancers, etc. miR-125b plays a key role in the occurrence and development of cancers, which can evaluate the therapeutic effects of various treatment methods of cancers by detecting the expression of miR-125b, and can assist in the diagnosis of cancers. It is of great significance to explore the mechanism of miR-125b in cancers for the treatment.

Objective To explore the effect of postoperative progressive resistance training (PRT) on the upper limb function in breast cancer patients. Methods 66 breast cancer patients were randomly divided into intervention group (n=33) and control group (n=33). The intervention group accepted a 12-week PRT and the control group accepted the routine training since 4-6 weeks postoperative as they admitted to hospital for their first chemotherapy. All the patients received a same content of health education. Results The grip strength, range of motion of abduction and flexion of shoulder were more in the intervention group than in the control group after intervention (P<0.01). Conclusion PRT can effectively improve the function of upper limbs in breast cancer patients.

We investigated the baseline brain activity level in patients with major depressive disorder (MDD) by am plitude of low-frequency fluctuation (ALFF) based on resting-state functional MRI (fMRI). We examined 13 patients in the MDD group and 14 healthy volunteers in the control group by resting-state fMRI on GE Signa 3.0T. We calculated and compared the ALFF values of the two groups. In the MDD group, ALFF values in the right medial prefrontal were higher than those in control group, with statistically significant differences (P < 0.001). ALFF values in the left parietal in the MDD group were lower than those in control group with statistically significant differences (P < 0.001). This resting-state fMRI study suggested that the alteration brain activity in the right medial prefrontal and left parietal ALFF contributed to the understanding of the pathophysiological mechanism of MDD patients.
Brain ; physiopathology ; Brain Mapping ; Case-Control Studies ; Depressive Disorder, Major ; physiopathology ; Humans ; Magnetic Resonance Imaging