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.

Objective:To analyze the expression of zinc homeostasis-related genes and related cells in the intestinal mucosa of inflammatory bowel disease (IBD) patients at the single-cell level and to evaluate their value in predicting the response to anti-tumor necrosis factor (TNF) therapy in IBD patients.Methods:Single-cell RNA sequencing data from 75 ileal or colorectal biopsy samples, including those from patients with Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC), were collected from four gene expression omnibus (GEO) databases. Unsupervised clustering analysis in R language was employed to classify IBD cells, zinc homeostasis-related gene scores were used to assess the zinc homeostasis status of different cell clusters, and the cell clusters closely related to zinc homeostasis-related genes, namely metallothionein-associated macrophages (MT Mph), were identified. Then the colon tissues from IBD patients and healthy individuals treated at the First Affiliated Hospital of Sun Yat-sen University were collected for immunofluorescence (IF) staining to compare the differences in MT Mph numbers between IBD and NC tissues. To further explore the function and origins of MT Mph, the characteristic genes of MT Mph and non- metallothionein-associated macrophages (non-MT Mph) from database were compared, the Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis was further used to enrich the characteristic genes, cell communication analysis was used to investigate the communication mechanisms between MT Mph and different cells, Quasi-time sequence was used to explore the origin of MT Mph and related signaling pathways, and the differences in transcription factors among monocytes, MT Mph and non-MT Mph were analyzed in R language. Single sample gene set enrichment analysis (ssGSEA) was used to evaluate the expression of MT Mph characteristic genes, and ssGSEA combined with the response to anti-TNF were used to construct the model in order to explore the predictive value of MT Mph characteristic genes for the response to anti-TNF therapy in IBD patients.Results:IBD cells were clustered and annotated into seven major cell clusters, namely T cells, B cells, plasma cells, myeloid cells, fibroblasts, endothelial cells, and epithelial cells. The results of zinc homeostasis-related gene scores showed that the scores of IBD myeloid cells were higher than those of the NC group. Myeloid cells could be divided into monocytes, macrophages, neutrophils, and dendritic cells. Based on the expression of zinc homeostasis genes, especially the high expression of metallothionein genes, the macrophages were divided into MT Mph and non-MT Mph, and the number of MT Mph in the IBD intestine was significantly increased compared to the NC group. IF validation showed that the number of CD68 +MT1G + cells (MT Mph) in both UC and CD were significantly higher than that in the NC group under per high-power field of view (UC vs. NC: 30.80 ± 7.29 vs. 9.80 ± 1.80, P < 0.001; CD vs. NC: 36.00 ± 9.30 vs. 9.80 ± 1.80, P < 0.001). KEGG pathway enrichment analysis revealed that the differential genes of MT Mph were enriched in key genes of inflammation-related pathways, especially the TNF signaling pathway. Cell communication analysis showed that the TNF signaling pathway between MT Mph and other cells in IBD was significantly enhanced compared to NC. Quasi-time sequence analysis results showed that monocytes could differentiate into MT Mph, and the expression of metallothionein genes ( MT2A, MT1X, MT1H and MT1G) was significantly upregulated during the differentiation process. Transcription factor analysis showed that the transcription factors SMARCB1 and ZMYND8 of MT Mph were significantly higher than those of monocytes, and the classical inflammatory transcription factors HIF1A, STAT3, and NFKB1 were significantly higher than those of non-MT Mph. Prediction models for CD and UC were constructed respectively based on ssGSEA and TNF treatment response [CD: area under the curve (AUC) = 0.966, P < 0.01; AUC = 0.793, P < 0.01]. Validation results showed that the model could not predict the response of CD and UC patients to vedolizumab therapy (both P > 0.05). Conclusions:There is a zinc homeostasis imbalance in IBD intestine, and MT Mph are a group of cells with high expression of zinc homeostasis-related genes, which are closely related to the TNF inflammatory pathway. The prediction model constructed based on the characteristic genes of MT Mph may be able to predict the response to anti-TNF therapy in IBD.

Objective:To analyze the expression of zinc homeostasis-related genes and related cells in the intestinal mucosa of inflammatory bowel disease (IBD) patients at the single-cell level and to evaluate their value in predicting the response to anti-tumor necrosis factor (TNF) therapy in IBD patients.Methods:Single-cell RNA sequencing data from 75 ileal or colorectal biopsy samples, including those from patients with Crohn's disease (CD), ulcerative colitis (UC), and normal controls (NC), were collected from four gene expression omnibus (GEO) databases. Unsupervised clustering analysis in R language was employed to classify IBD cells, zinc homeostasis-related gene scores were used to assess the zinc homeostasis status of different cell clusters, and the cell clusters closely related to zinc homeostasis-related genes, namely metallothionein-associated macrophages (MT Mph), were identified. Then the colon tissues from IBD patients and healthy individuals treated at the First Affiliated Hospital of Sun Yat-sen University were collected for immunofluorescence (IF) staining to compare the differences in MT Mph numbers between IBD and NC tissues. To further explore the function and origins of MT Mph, the characteristic genes of MT Mph and non- metallothionein-associated macrophages (non-MT Mph) from database were compared, the Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis was further used to enrich the characteristic genes, cell communication analysis was used to investigate the communication mechanisms between MT Mph and different cells, Quasi-time sequence was used to explore the origin of MT Mph and related signaling pathways, and the differences in transcription factors among monocytes, MT Mph and non-MT Mph were analyzed in R language. Single sample gene set enrichment analysis (ssGSEA) was used to evaluate the expression of MT Mph characteristic genes, and ssGSEA combined with the response to anti-TNF were used to construct the model in order to explore the predictive value of MT Mph characteristic genes for the response to anti-TNF therapy in IBD patients.Results:IBD cells were clustered and annotated into seven major cell clusters, namely T cells, B cells, plasma cells, myeloid cells, fibroblasts, endothelial cells, and epithelial cells. The results of zinc homeostasis-related gene scores showed that the scores of IBD myeloid cells were higher than those of the NC group. Myeloid cells could be divided into monocytes, macrophages, neutrophils, and dendritic cells. Based on the expression of zinc homeostasis genes, especially the high expression of metallothionein genes, the macrophages were divided into MT Mph and non-MT Mph, and the number of MT Mph in the IBD intestine was significantly increased compared to the NC group. IF validation showed that the number of CD68 +MT1G + cells (MT Mph) in both UC and CD were significantly higher than that in the NC group under per high-power field of view (UC vs. NC: 30.80 ± 7.29 vs. 9.80 ± 1.80, P < 0.001; CD vs. NC: 36.00 ± 9.30 vs. 9.80 ± 1.80, P < 0.001). KEGG pathway enrichment analysis revealed that the differential genes of MT Mph were enriched in key genes of inflammation-related pathways, especially the TNF signaling pathway. Cell communication analysis showed that the TNF signaling pathway between MT Mph and other cells in IBD was significantly enhanced compared to NC. Quasi-time sequence analysis results showed that monocytes could differentiate into MT Mph, and the expression of metallothionein genes ( MT2A, MT1X, MT1H and MT1G) was significantly upregulated during the differentiation process. Transcription factor analysis showed that the transcription factors SMARCB1 and ZMYND8 of MT Mph were significantly higher than those of monocytes, and the classical inflammatory transcription factors HIF1A, STAT3, and NFKB1 were significantly higher than those of non-MT Mph. Prediction models for CD and UC were constructed respectively based on ssGSEA and TNF treatment response [CD: area under the curve (AUC) = 0.966, P < 0.01; AUC = 0.793, P < 0.01]. Validation results showed that the model could not predict the response of CD and UC patients to vedolizumab therapy (both P > 0.05). Conclusions:There is a zinc homeostasis imbalance in IBD intestine, and MT Mph are a group of cells with high expression of zinc homeostasis-related genes, which are closely related to the TNF inflammatory pathway. The prediction model constructed based on the characteristic genes of MT Mph may be able to predict the response to anti-TNF therapy in IBD.

BACKGROUND:After total knee arthroplasty,patients may experience significant pain,which has negative effects on functional recovery.Exploring and seeking effective means of analgesia has important clinical value.OBJECTIVE:To explore an effective perioperative analgesic strategy for total knee arthroplasty patients,we first proposed a novel local infiltration anesthetic formulation consisting of morphine,flurbiprofen,and compound betamethasone,and we explored its efficacy and safety.METHODS:This study retrospectively analyzed the clinical data of 60 patients who underwent unilateral total knee arthroplasty at First Affiliated Hospital of Anhui Medical University from January 2023 to April 2024.Based on whether local anesthesia was used during surgery,the patients were divided into the control and study groups,each consisting of 30 cases.In the study group,the local infiltration anesthesia mixture consisting of morphine,flurbiprofen,and compound betamethasone was injected into the joint cavity around the knee during surgery.No analgesic drugs were used in the control group as a blank control.We recorded and compared the postoperative visual analog scale pain scores,knee range of motion,knee function score,degree of postoperative knee edema,and incidence of postoperative complications between the two groups at different time points.RESULTS AND CONCLUSION:(1)Compared with the control group,the visual analog scale pain score in the study group was lower at 6,12,and 24 hours after operation,and the difference was statistically significant(Z=-2.367,-2.906,-4.199,P＜0.05).However,there was no significant difference in the pain visual analog scale score between the two groups at 48 and 72 hours after operation(Z=-1.287,-1.478,P＞0.05).(2)The postoperative knee range of motion and knee function score of the study group were better than those of the control group,and the difference was statistically significant(t=-2.519,-8.027,P＜0.05).(3)The degree of knee joint swelling in the study group was also lighter than that in the control group,and the difference was statistically significant(Z=-2.818,P＜0.05).(4)In the early postoperative period,there was no significant difference in fever between the two groups(P＞0.05).There was no poor wound healing or periprosthetic infection in the two groups.(5)The results show that applying local infiltration anesthesia composed of morphine,flurbiprofen axetil,and compound betamethasone in total knee arthroplasty can relieve early postoperative pain and show high safety.However,prospective studies with large samples are still needed to provide data support.

BACKGROUND:After total knee arthroplasty,patients may experience significant pain,which has negative effects on functional recovery.Exploring and seeking effective means of analgesia has important clinical value.OBJECTIVE:To explore an effective perioperative analgesic strategy for total knee arthroplasty patients,we first proposed a novel local infiltration anesthetic formulation consisting of morphine,flurbiprofen,and compound betamethasone,and we explored its efficacy and safety.METHODS:This study retrospectively analyzed the clinical data of 60 patients who underwent unilateral total knee arthroplasty at First Affiliated Hospital of Anhui Medical University from January 2023 to April 2024.Based on whether local anesthesia was used during surgery,the patients were divided into the control and study groups,each consisting of 30 cases.In the study group,the local infiltration anesthesia mixture consisting of morphine,flurbiprofen,and compound betamethasone was injected into the joint cavity around the knee during surgery.No analgesic drugs were used in the control group as a blank control.We recorded and compared the postoperative visual analog scale pain scores,knee range of motion,knee function score,degree of postoperative knee edema,and incidence of postoperative complications between the two groups at different time points.RESULTS AND CONCLUSION:(1)Compared with the control group,the visual analog scale pain score in the study group was lower at 6,12,and 24 hours after operation,and the difference was statistically significant(Z=-2.367,-2.906,-4.199,P＜0.05).However,there was no significant difference in the pain visual analog scale score between the two groups at 48 and 72 hours after operation(Z=-1.287,-1.478,P＞0.05).(2)The postoperative knee range of motion and knee function score of the study group were better than those of the control group,and the difference was statistically significant(t=-2.519,-8.027,P＜0.05).(3)The degree of knee joint swelling in the study group was also lighter than that in the control group,and the difference was statistically significant(Z=-2.818,P＜0.05).(4)In the early postoperative period,there was no significant difference in fever between the two groups(P＞0.05).There was no poor wound healing or periprosthetic infection in the two groups.(5)The results show that applying local infiltration anesthesia composed of morphine,flurbiprofen axetil,and compound betamethasone in total knee arthroplasty can relieve early postoperative pain and show high safety.However,prospective studies with large samples are still needed to provide data support.

BACKGROUND:The use of vancomycin in total knee arthroplasty is a controversial strategy for the prevention of incisional infection.At present,there is little evidence to evaluate the efficacy of this preventive measure in China. OBJECTIVE:To evaluate the efficacy of local vancomycin in the prevention of early postoperative incision infection during total knee arthroplasty. METHODS:120 patients with osteoarthritis of the knee who received unilateral total knee arthroplasty for the first time at Department of Joint Surgery of First Affiliated Hospital of Anhui Medical University from March to June 2022 were included in this study.They were randomly divided into the observation group and the control group,with 60 cases in each group.All patients gave informed consent to the treatment plan.In the observation group,1 g of vancomycin was applied intraoperatively;in the control group,no vancomycin was applied intraoperatively.Erythrocyte sedimentation rate,C-reactive protein,fever rate on seven consecutive days after surgery,degree of knee joint swelling,cumulative drainage volume,and incidence of periprosthetic joint infection were recorded in two groups of patients on days 1,3,and 5 after surgery so as to evaluate the efficacy of topical vancomycin in total knee arthroplasty for the prevention of incision infection in the early postoperative period. RESULTS AND CONCLUSION:(1)The differences in erythrocyte sedimentation rate and C-reactive protein between the two groups on days 1,3,and 5 after surgery were not significant(P>0.05).(2)The difference in fever rate between the two groups for 7 consecutive days after surgery was not significant(P>0.05).(3)There was no significant difference in the degree of postoperative knee swelling and cumulative drainage flow between the two groups(P>0.05).(4)The difference in the incidence of periprosthetic joint infection one year after surgery was not significant between the two groups(P>0.05).(5)The results suggest that the local use of vancomycin in total knee arthroplasty has not shown significant efficacy in preventing incision infection in the early postoperative period.

Objective:The emergence of polymyxin-resistant Klebsiella pneumoniae(KPN)in clinical settings necessitates an analysis of its antibiotic resistance characteristics,epidemiological features,and risk factors for its development.This study aims to provide insights for the prevention and control of polymyxin-resistant KPN infections. Methods:Thirty clinical isolates of polymyxin-resistant KPN were collected from the Third Xiangya Hospital of Central South University.Their antibiotic resistance profiles were analyzed.The presence of carbapenemase KPC,OXA-48,VIM,IMP,and NDM was detected using colloidal gold immunochromatography.Hypervirulent KPN was initially screened using the string test.Biofilm formation capacity was assessed using crystal violet staining.Combination drug susceptibility tests(polymyxin B with meropenem,tigecycline,cefoperazone/sulbactam)were conducted using the checkerboard method.Polymyxin-related resistance genes were detected by PCR.Multi-locus sequence typing(MLST)was performed for genotyping and phylogenetic tree construction.The study also involved collecting data from carbapenem-resistant(CR)-KPN polymyxin-resistant strains(23 strains,experimental group)and CR-KPN polymyxin-sensitive strains(57 strains,control group)to analyze potential risk factors for polymyxin-resistant KPN infection through univariate analysis and multivariate Logistic regression.The induction of resistance by continuous exposure to polymyxin B and colistin E was also tested. Results:Among the 30 polymyxin-resistant KPN isolates,28 were CR-KPN,all producing KPC enzyme.Four isolates were positive in the string test.Most isolates showed strong biofilm formation capabilities.Combination therapy showed additive or synergistic effects.All isolates carried the pmrA and phoP genes,while no mcr-1 or mcr-2 genes were detected.MLST results indicated that ST11 was the predominant type.The phylogenetic tree suggested that polymyxin-resistant KPN had not caused a hospital outbreak in the institution.The use of two or more different classes of antibiotics and the use of polymyxin were identified as independent risk factors for the development of polymyxin-resistant strains.Continuous use of polymyxin induced drug resistance. Conclusion:Polymyxin-resistant KPN is resistant to nearly all commonly used antibiotics,making polymyxin-based combination therapy a viable option.No plasmid-mediated polymyxin-resistant KPN has been isolated in the hospital.Polymyxin can induce resistance in KPN,highlighting the need for rational antibiotic use in clinical settings to delay the emergence of resistance.

Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins. Here, we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var. yunnanensis. Among them, a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides, respectively. These UDP-glycosyltransferases showed astonishing substrate promiscuity, resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds. A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments, and a mutant UGT91AH1^Y187A with increased catalytic efficiency was obtained. The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes, and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects. The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.

Humans ; Inflammatory Bowel Diseases/drug therapy* ; Interleukin-6/therapeutic use*

Objective To seperate fetal nucleated red blood cells (fNRBCs) from the whole maternal peripheral blood effectively by designing a circular channel microfluidic chip. Methods A microfluidic chip is designed by utilizing the margination in blood flow and the specific adhesion characteristics of immuno-agent anti-CD147. With the whole umbilical cord blood, the effects of different shear forces on the enrichment of fNRBCs was studied by immunofluorescence counting. Results Increasing shear rate in microfluidic chip could improve the number of captured fNRBCs compared with the static adhesion. With the increase of shear rate of blood flow, the number of the captured cells increased at first, and then decreased. Conclusions The use of microfluid chip can effectively seperate fNRBCs from the whole blood. The results provide an experimental reference for the non-invasive prenatal diagnosis research and the exploration on the mechanism of fetal cell migration.