Flap transplantation is a critical surgical strategy for the reconstruction of tissue defects caused by trauma, tumor resection, and congenital malformations, and its survival rate directly determines surgical efficacy and patient prognosis. Following transplantation, flaps inevitably undergo ischemia-reperfusion (I/R) injury, during which oxidative stress, inflammatory responses, and metabolic disturbances are intricately intertwined, ultimately leading to cellular injury and tissue necrosis. Recent studies have demonstrated that multiple forms of programmed cell death—including apoptosis, pyroptosis, ferroptosis, necroptosis, and PANoptosis—play central roles in flap I/R injury. The extensive crosstalk and molecular interactions among these pathways form a highly complex cell death network. Specifically, apoptosis is mediated by the imbalance of Bcl-2 family proteins and the activation of cysteine-dependent aspartate-specific protease (caspase) cascades; pyroptosis is driven by the NLRP3-caspase-1-GSDMD axis, resulting in membrane pore formation and the release of pro-inflammatory cytokines; ferroptosis is characterized by iron-dependent lipid peroxidation and dysfunction of glutathione peroxidase 4 (GPX4); necroptosis is triggered by the receptor-interacting serine/threonine-protein kinase 1 (RIPK1)-RIPK3-MLKL signaling complex, leading to membrane rupture; and PANoptosis represents an integrated form of inflammatory cell death that coordinates multiple death pathways. Importantly, these forms of programmed cell death are not independent but are interconnected through extensive signaling crosstalk. Key regulatory molecules, including caspase-8, reactive oxygen species (ROS), nuclear factor-κB (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2), collectively modulate the dynamic balance among these pathways. Therefore, the multidimensional interplay and spatiotemporal dynamics of programmed cell death constitute a fundamental pathological basis of flap I/R injury. This review systematically summarizes the latest advances in the mechanisms and interactions of various programmed cell death pathways in flap I/R injury, aiming to elucidate the underlying regulatory network. These insights may provide novel theoretical foundations for optimizing flap protection strategies, improving flap survival, and promoting tissue repair.

ObjectiveTo explore the changes in volatile components， total polysaccharides， enzyme activity， and chromaticity value of Myristicae Semen Koji（MSK） during the fermentation process， and conduct correlation analysis. MethodsBased on gas chromatography-mass spectrometry（GC-MS）， the changes of volatile components in MSK at different fermentation times were identified. The phenol sulfuric acid method， dinitrosalicylic acid method（DNS）， and carboxymethyl cellulose sodium salt method（CMC-Na） were used to investigate the total polysaccharide content， amylase activity， and cellulase activity during the fermentation process. Visual analysis technology was used to explore the changes in chromaticity values， revealing the fermentation process of MSK and the dynamic changes of various measurement indicators， partial least squares-discriminant analysis（PLS-DA） was used to explore the differential compounds of MSK at different fermentation degrees， and Pearson correlation analysis was used to explore the correlation between volatile components of MSK and total polysaccharides， enzyme activity， and chromaticity values. ResultsA total of 60 volatile compounds were identified from MSK， the relative contents of components such as （+）-α-pinene， β-phellandrene， β-pinene， （+）-limonene， and p-cymene obviously increased， while the relative contents of components such as safrole， methyl isoeugenol， methyleugenol， myristicin， and elemicin significantly decreased. During the fermentation process， the total polysaccharide content showed an upward trend， while the activities of amylase and cellulase showed an initial increase followed by a decrease， and reached their maximum value at 40 h. the overall brightness（L^*） and total color difference（ΔE^*） gradually increased， while the changes in red-green value（a^*） and yellow-blue value（b^*） were not obvious. PLS-DA results showed that MSK could be clearly distinguished at different fermentation times， and 13 differential biomarkers were screened out. Pearson correlation analysis results showed that the contents of α-terpinene， β-phellandrene， methyleugenol， β-cubebene and myristic acid had an obvious correlation with chromaticity values. ConclusionAfter fermentation， the volatile components， total polysaccharides， amylase activity， and cellulase activity of MSK undergo significant changes， and there is a clear correlation between them and chromaticity values， which reveals the dynamic changes in the fermentation process and related indicators of MSK， laying a foundation for the quality control.

Objective: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The APTADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (–0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54).However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.

Objective: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The APTADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (–0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54).However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.

Objective: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The APTADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (–0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54).However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.

BACKGROUND:The imbalance between bone resorption and bone formation in microgravity environments leads to significant bone loss in astronauts.Current research indicates that bone loss under microgravity conditions is the result of the combined effects of various cells,tissues,and systems. OBJECTIVE:To review different biological effects of microgravity on various cells,tissues,or systems,and summarize the mechanisms by which microgravity leads to the development of osteoporosis. METHODS:Databases such as PubMed,Web of Science,and the Cochrane Database were searched for relevant literature from 2000 to 2023.The inclusion criteria were all articles related to tissue engineering studies and basic research on osteoporosis caused by microgravity.Ultimately,85 articles were included for review. RESULTS AND CONCLUSION:(1)In microgravity environment,bone marrow mesenchymal stem cells tend to differentiate more into adipocytes rather than osteoblasts,and hematopoietic stem cells in this environment are more inclined to differentiate into osteoclasts,reducing differentiation into the erythroid lineage.At the same time,microgravity inhibits the proliferation and differentiation of osteoblasts,promotes apoptosis of osteoblasts,alters cell morphology,and reduces the mineralization capacity of osteoblasts.Microgravity significantly increases the number and activity of osteoclasts.Microgravity also hinders the differentiation of osteoblasts into osteocytes and promotes the apoptosis of osteocytes.(2)In a microgravity environment,the body experiences changes such as skeletal muscle atrophy,microvascular remodeling,bone microcirculation disorders,and endocrine disruption.These changes lead to mechanical unloading in the bone microenvironment,insufficient blood perfusion,and calcium cycle disorders,which significantly impact the development of osteoporosis.(3)At present,the mechanism by which microgravity causes osteoporosis is relatively complex.A deeper study of these physiological mechanisms is crucial to ensuring the health of astronauts during long-term space missions,and provides a theoretical basis for the prevention and treatment of osteoporosis.

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: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The APTADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (–0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54).However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.

Objective: Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors. Methods: Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1). Results: The APTADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (–0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54).However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group. Conclusions In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.