Entering into the 1990s, Chinese scientists have made mice, drosophila and silkworm eggs experiments in space with satellites and achieved remarkable results. These animals were put in space environment units with the...Entering into the 1990s, Chinese scientists have made mice, drosophila and silkworm eggs experiments in space with satellites and achieved remarkable results. These animals were put in space environment units with the ability of adjusting pressure, temperature and moisture control, air conditioning and purifying as well as foods and water supply. After 8-days’ flight, all performance parameters were normal and met the design requirements. The two mice kept alive for 5 days and 10 hours展开更多
This study aimed to evaluate the feasibility and safety of a novel stent manufactured by metal injection molding(MIM)in clinical practice through animal experiments.Vessel stents were prepared using powder injection m...This study aimed to evaluate the feasibility and safety of a novel stent manufactured by metal injection molding(MIM)in clinical practice through animal experiments.Vessel stents were prepared using powder injection molding technology to considerably improve material utilization.The influence of MIM carbon impurity variation on the mechanical properties and corrosion resistance of 316L stainless steel was studied.In vitro cytotoxicity and animal transplantation tests were also carried out to evaluate the safety of MIM stents.The results showed that the performance of 316L stainless steel was very sensitive to the carbon content.Carbon fluctuations should be precisely controlled during MIM.All MIM stents were successfully implanted into the aortas of the dogs,and the MIM 316L stents had no significant cytotoxicity.The novel intravascular stent manufactured using MIM can maintain a stable form and structure with fast endothelialization of the luminal surface of the stent and ensure long-term patency in an animal model.The novel intravascular stent manufactured using MIM demonstrates favorable structural,physical,and chemical stability,as well as biocompatibility,offering promising application in clinical practice.展开更多
Objective:To screen and identify the key active molecules,signaling pathways,and therapeutic targets of Shuxuening(SXN)injection for treating liver cirrhosis(LC)and to evaluate its therapeutic potential using a mouse ...Objective:To screen and identify the key active molecules,signaling pathways,and therapeutic targets of Shuxuening(SXN)injection for treating liver cirrhosis(LC)and to evaluate its therapeutic potential using a mouse model.Methods:Target genes of SXN and LC were retrieved from public databases,and enrichment analysis was performed.A proteineprotein interaction(PPI)network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins(STRING),and hub genes were identified using Molecular Complex Detection(MCODE).LC was induced in rats and mice via intraperitoneal injections of diethylnitrosamine and carbon tetrachloride(CCl4)for 12 weeks.Starting at week 7,SXN was administered intraperitoneally to the mice in the treatment group.Serum and liver tissues of the mice were collected for the detection of indicators,pathological staining,and expression analysis of hub targets using quantitative real-time polymerase chain reaction(qRT-PCR).Results:We identified 368 overlapping genes(OLGs)between SXN and LC targets.These OLGs were subsequently used to build a PPI network and to screen for hub genes.Enrichment analysis showed that these genes were associated with cancer-related pathways,including phosphoinositide-3-kinase/Akt and mitogen-activated protein kinase signaling and various cellular processes,such as responses to chemicals and metabolic regulation.In vivo experiments demonstrated that SXN treatment significantly improved liver function and pathology in CCl4-induced LC mice by reducing inflammation and collagen deposition.Furthermore,qRT-PCR demonstrated that SXN regulated the expression of MAPK8,AR and CASP3 in the livers of LC mice.Conclusion:This study highlighted the therapeutic effects of SXN in alleviating LC using both bioinformatics and experimental methods.The observed effect was associated with modulation of hub gene expression,particularly MAPK8,and CASP3.展开更多
Animal models are crucial for the study of severe infectious diseases,which is essential for determining their pathogenesis and the development of vaccines and drugs.Animal experiments involving risk grade 3 agents su...Animal models are crucial for the study of severe infectious diseases,which is essential for determining their pathogenesis and the development of vaccines and drugs.Animal experiments involving risk grade 3 agents such as SARS CoV,HIV,M.tb,H7N9,and Brucella must be conducted in an Animal Biosafety Level 3(ABSL-3)facility.Because of the in vivo work,the biosafety risk in ABSL-3 facilities is higher than that in BSL-3 facilities.Undoubtedly,management practices must be strengthened to ensure biosafety in the ABSL-3 facility.Meanwhile,we cannot ignore the reliable scientific results obtained from animal experiments conducted in ABSL-3 laboratories.It is of great practical significance to study the overall biosafety concepts that can increase the scientific data quality.Based on the management of animal experiments in the ABSL-3 Laboratory of Wuhan University,combined with relevant international and domestic literature,we indicate the main safety issues and factors affecting animal experiment results at ABSL-3 facilities.Based on these issues,management practices regarding animal experiments in ABSL-3 facilities are proposed,which take into account both biosafety and scientifically sound data.展开更多
At a time when there is a growing public interest in animal welfare,it is critical to have objective means to assess the way that an animal experiences a situation.Objectivity is critical to ensure appropriate animal ...At a time when there is a growing public interest in animal welfare,it is critical to have objective means to assess the way that an animal experiences a situation.Objectivity is critical to ensure appropriate animal welfare outcomes.Existing behavioural,physiological,and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes.But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal,from negative to positive.In this review,we draw from the knowledge of human biomedical science to propose a list of candidate biological markers(biomarkers)that should reflect the experiential state of non-human animals.The proposed biomarkers can be classified on their main function as endocrine,oxidative stress,non-coding molecular,and thermobiological markers.We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.展开更多
Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is...Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.展开更多
Schizophrenia,as a common mental disease,seriously threatens the physical and mental health of human beings.It is characterized by many mental and behavioral disorders,such as uncoordinated thinking and emotional mode...Schizophrenia,as a common mental disease,seriously threatens the physical and mental health of human beings.It is characterized by many mental and behavioral disorders,such as uncoordinated thinking and emotional mode which separated from the actual living environment.Patients with schizophrenia are prone to relapse and deterioration due to their long course of disease,resulting in the loss of labor force.It has been proved that the occurrence and development of schizophrenia is closely related to the abnormal development of oligodendrocytes,which have the function of myelin formation and the dysfunction of myelin sheath itself.For a comprehensive understanding of myelin abnormal effects on the pathogenesis of schizophrenia,this paper is to review the literature,then summarize and discuss the animal experimental literature related to the abnormal myelin sheath in schizophrenia from the perspectives of behavioristics,neuroimaging,protein expression and stereology,in order to further clarify the influence of the abnormal myelin sheath on the pathogenesis of schizophrenia and provide ideas for the diagnosis of schizophrenia and the research and development of new drugs.展开更多
The animal experiment is the best method for therapeutic efficacy testing of various treatment methods before clinical application and serves as an irreplaceable“live reagent”and“live precise instrument,”thus play...The animal experiment is the best method for therapeutic efficacy testing of various treatment methods before clinical application and serves as an irreplaceable“live reagent”and“live precise instrument,”thus playing a vital role in biomedical science research.However,there were significant differences between the results of animal experiments and clinical efficacy in previousfindings that are hard to ignore,especially in cerebrovascular accident research due to the unsatisfactory specification of animal experiments.Accordingly,more prescriptive and standard tools are required for evaluating the quality of animal experiments.This study will introduce the current commonly used quality evaluation tools for animal experiments.展开更多
Introduction: Radiotherapy is often used to treat head and neck malignancies, with inevitable effects on the surrounding healthy tissues. We have reviewed the literature concerning the experimental irradiation of faci...Introduction: Radiotherapy is often used to treat head and neck malignancies, with inevitable effects on the surrounding healthy tissues. We have reviewed the literature concerning the experimental irradiation of facial bones in animals. Materials and Methods: A PubMed search was performed to retrieve animal experiments on the irradiation of facial bones that were published between January 1992 and January 2012. The search terms were “irradiation facial bone” and “irradiation osteoradionecrosis”. Results: Thirty-six publications were included. The irradiation sources were Cobalt60, orthovoltage, 4 - 6 megavolt photons, and brachytherapy. The total dose varied between 8 - 60 Gy in single or multiple fractions. The literature presents a broad range of animal studies that differ in terms of the in vivo model, irradiation, observation period, and evaluation of results. Discussion: The different animal models used leave many questions unanswered. A detailed and standardized description of the methodology and results would facilitate the comparability of future studies.展开更多
AIM To assess the feasibility and safety of a novel enteroscope,negative-pressure suction endoscope in examining the small intestine of a porcine model.METHODS In vitro experiments in small intestinal loops from 20pig...AIM To assess the feasibility and safety of a novel enteroscope,negative-pressure suction endoscope in examining the small intestine of a porcine model.METHODS In vitro experiments in small intestinal loops from 20pigs and in vivo experiments in 20 living pigs were conducted.RESULTS In in vitro experiments,a negative pressure of>0.06MPa was necessary for optimal visualization of the intestine,and this pressure did not cause gross or histological damage to the mucosa.For satisfactory examination of the small intestine in vivo,higher negative pressure(>1.00 MPa)was required.Despite this higher pressure,the small intestine did not show any gross or microscopic damage in the suctioned areas.The average time of examination in the living animals was 60±7.67 min.The animals did not experience any apparent ill effects from the procedure.CONCLUSION Small intestine endoscope was safely performed within a reasonable time period and enabled complete visualization of the intestine in most cases.展开更多
Titanium rods were processed into implant samples with cavity and groove in which was filled with HAP/β-TCP porous osteoconduction composite materials in order to increase the mechanical stability of the implant in v...Titanium rods were processed into implant samples with cavity and groove in which was filled with HAP/β-TCP porous osteoconduction composite materials in order to increase the mechanical stability of the implant in vivo.The phase compositions of the composite was characterized by X-ray diffraction （XRD） and scanning electron microscopy（SEM）.Histological evaluation showed that the biogradable composite could enhanced the ability of new bone formation.The composite can conduct new bone tissue growing into the cavities gradually after implanted into animal,and then achieve mechanical fixation.The filling biogradable compound exhibited excellent biocompatibility,which combined with the new bone tissues tightly without inflammation and loosing.展开更多
CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expresse...CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.展开更多
This work used the cosmological neuroscientific concept of Soul of Multiverse for placing the problem of wildlife and biodiversity protection into a new philosophical environment where religious,scientific and philoso...This work used the cosmological neuroscientific concept of Soul of Multiverse for placing the problem of wildlife and biodiversity protection into a new philosophical environment where religious,scientific and philosophical approaches are in harmony.It resulted in the thought that the obligation of protecting wildlife and biodiversity on Earth,just as the sanctity of caring for all human lives,originated in cosmic laws set in the divine blueprints of the Soul of Multiverse.These laws seem to relay that in the 21st century the time has come on Earth to stop killing animals for food,to stop overhunting and overfishing,to stop industrial activities responsible for deforestation,desertification,air pollution and climate change,and to run animal experiments for science and medicine only in the extremely limited,most justified cases and only until new technologies make them no longer necessary.The conclusion was that to achieve these goals,new global governing mechanisms are needed.Specifically,the establishment of a Government of Earth,the next step of the political process that started with the United Nations in the first place,may be necessary to solve the global problems of wildlife and biodiversity protection since meaningful solutions for global problems require global governing mechanisms.展开更多
Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading ...Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-innervation, but further functional measurements are still required.展开更多
A Bordetella hinzii strain, isolated from the lung of a dead breast-feeding infant rex rabbit with a respiratory infection, was used as study object to investigate its phenotypic and genetic characteristics. The strai...A Bordetella hinzii strain, isolated from the lung of a dead breast-feeding infant rex rabbit with a respiratory infection, was used as study object to investigate its phenotypic and genetic characteristics. The strain could grow on MacConkey agar and was gram-negative, oxidase-positive, catalase-positive, short rodshaped, and it can produce alkali from malonate. Its 6S rRNA sequence was partially identical with B. hinzii （AF177667）. Animal experiments revealed nasal mucous hyperemia, tracheal congestion and bronchopneumonia in 28-day old rex rabbits. To sum up, this Bordetella hinzii isolate was deemed as a novel causative agent of respiratory disease in rex rabbit.展开更多
Purpose: The purpose of this study was to develop a method for quantifying the extent of renal dysfunction due to drug-induced nephrotoxicity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investi...Purpose: The purpose of this study was to develop a method for quantifying the extent of renal dysfunction due to drug-induced nephrotoxicity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate the protective effects of various antioxidant agents against cis-dichlorodiammineplatinum (cisplatin)-induced nephrotoxicity in rats using this method. Materials and Methods: The DCE-CT studies were performed in 8-week-old male Sprague-Dawley rats. The CT scanning started 4 s before a bolus intravenous injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 90 s at 1-s intervals. The contrast clearance per unit renal volume (K1) was estimated from the DCE-CT data using the Patlak model. The renal volume (V) was calculated by manually delineating the kidney on the CT image. The contrast clearance of the entire kid-ney (K) was obtained by . First, to investigate the effect of CA itself, the DCE-CT studies were performed without injecting cisplatin 2, 4, and 7 days after the first DCE-CT study on day 0. Second, to investigate the effect of injected dose of cisplatin, the DCE-CT study was performed after the intraperitoneal (i.p.) injection of cisplatin (1.8 mg/kg) and was repeated every other day for one week. Finally, to investigate the protective effects of antioxidant agents [L-arginine (300 mg/kg), N-acetylcysteine (500 or 1000 mg/kg), methimazole (40 mg/kg), captopril (60 mg/kg), and taurine (750 mg/kg)], the DCE-CT studies were performed on days 0, 2, 4, and 7 after the i.p. injection of cisplatin (3.6 mg/kg). For comparison, the DCE-CT data were also acquired without injecting the antioxidant agents (CDDP group). Results: When cisplatin was not injected, there were no significant changes in the K value as compared to that on day 0 within the studied period. The K valuesignificantly (p < 0.05) decreased with increasing dose of cisplatin. Although some differences were observed in the extent of change in the K value normalized by that on day 0, depending on the antioxidant agents and their injected dose and schedule, the normalized K values on day 7 in the groups injected with the antioxidant agents were significantly higher than those in the CDDP group, suggesting that the antioxidant agents studied here had protective effects against cisplatin-induced nephrotoxicity in varying degrees. Conclusion: Our method appears useful for quantitatively evaluating the protective effects of antioxidant agents against cisplatin-induced nephrotoxicity and for investigating the optimal injected dose and schedule of the agents, because it allows repeated measurements of split renal function in a single animal.展开更多
Objective To investigate the feasibility of magnetic resonance （MR） diffusion weighted imaging （DWI） for evaluation of radiotherapeutic effects on rabbit VX2 tumor model. Methods Sixteen New Zealand white rabbits...Objective To investigate the feasibility of magnetic resonance （MR） diffusion weighted imaging （DWI） for evaluation of radiotherapeutic effects on rabbit VX2 tumor model. Methods Sixteen New Zealand white rabbits received a subcutaneous implantation of VX2 tumor cell suspension 0.5 mL （4× 10^7 ceUs/mL） in their right thighs to set up tumor model. And 2 weeks later they were randomly divided into therapy group （Group T, n = 10） and control group （Group C, n = 6）. Group T received radiotherapy at a single dose of 10 Gy. MR imaging （MRI） scan including short TI inversion recovery echo-planar imaging DWI, T1-weighted imaging （T1WI） and T2-weighted imaging （T2WI） sequences were performed 1 day prior to as well as 1 day, 2 days, 3 days and 7 days after radiotherapy. Group C received only MRI scan at the same time points without any treatment. MRI appearance on T2WI, TlWI, and DWI images was compared and tumor volume was calculated. Apparent diffusion coefficient （ADC） values of the tumor were evaluated in all cases. HE staining was used for pathological study. Results Necrosis （n = 8） and hemorrhage （n = 2） were seen gradually on T2WI and T1WI images of Group T after time point of day 2 after irradiation. In Group C, no obvious necrosis was found until day 7. There was no significant difference in tumor volume between the two groups before radiotherapy. After radiotherapy, tumors in Group T showed a gradual growth but not as obvious as Group C. There was a significant difference in tumor volume between the two groups from day 2 on （P 〈 0.05）. ADC value changed dramatically fight from the 1st day after radiotherapy in Group T [（0.99 ± 0.15） ×10^-3 mm^2/s for 1 day before radiotherapy, （1.23 ± 0.08） ×10^-3 , （1.45 ± 0.07） ×10^-3 , （1.63 ± 0.06） ×10^-3 , and （2.02 ± 0.18） ×10^-3 mm^2 for day 1, 2, 3, and 7]; and ADC value had no significant changes after radiotherapy in Group C except day 7 [（1.07±0.08） ×10^-3 mm^2 for 1 day before radiotherapy, （1.03 ± 0.04）×10^-3 , （1.05 ± 0.02）×10^-3 , （1.05 ± 0.05） ×10^-3 , and （0.95 ± 0.07） ×10^-3 mm^2 for day 1, 2, 3, and 7]. There was significant difference in ADC value between the two groups for each time point after radiotherapy （P 〈 0.01）. Pathological study showed that the number of viable tumor cells in Group T decreased 1 day after radiotherapy, and the inflammatory cell infiltration was marked and almost all viable tumor cells disappeared by day 7 after radiotherapy. Conclusions DWI is a new promising technique for monitoring radiotherapy outcomes. ADC value may give a prior clue on physiological changes of radiotherapy before routine MRI could tell.展开更多
Brain diseases, including brain tumors, neurodegenerative disorders, cerebrovasculardiseases, and traumatic brain injuries, are among the major disordersinfluencing human health, currently with no effective therapy. D...Brain diseases, including brain tumors, neurodegenerative disorders, cerebrovasculardiseases, and traumatic brain injuries, are among the major disordersinfluencing human health, currently with no effective therapy. Due to the lowregeneration capacity of neurons, insufficient secretion of neurotrophic factors,and the aggravation of ischemia and hypoxia after nerve injury, irreversible lossof functional neurons and nerve tissue damage occurs. This damage is difficult torepair and regenerate the central nervous system after injury. Neural stem cells(NSCs) are pluripotent stem cells that only exist in the central nervous system.They have good self-renewal potential and ability to differentiate into neurons,astrocytes, and oligodendrocytes and improve the cellular microenvironment.NSC transplantation approaches have been made for various neurodegenerativedisorders based on their regenerative potential. This review summarizes anddiscusses the characteristics of NSCs, and the advantages and effects of NSCs inthe treatment of brain diseases and limitations of NSC transplantation that need tobe addressed for the treatment of brain diseases in the future.展开更多
AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model...AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model was established. Fortytwo female FVB/N mice were randomly divided into the following three groups: group 1(10 mice, negative control) was treated with vehicle, group 2(16 mice, positive control) was treated with AOM plus vehicle, and group 3(16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci(ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16 S r RNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16 S r RNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTS Treatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS(5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85%(33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the diversity of gut microbiota increased, potential carcinogenic bacteria such as Bacteroides were enriched, and the abundance of butyrate-producing bacteria(Clostridiaceae, Ruminococcus, etc.) decreased continuously. In contrast, the structure of gut microbiota was relatively stable during the intervention of EGCG on colon carcinogenesis. Enrichment of probiotics(Bifidobacterium, Lactobacillu, etc.) might be a potential mechanism for EGCG's effects on tumor suppression. Via bioinformatics analysis, principal coordinate analysis and cluster analysis of the tumor formation process, we found that the diversity of gut microbiota increased in the tumor model group while that in the EGCG interfered group(EG) remained relatively stable.CONCLUSION Gut microbiota imbalance might be a potential mechanism for the prevention of malignant transformation by EGCG, which is significant for diagnosis, treatment, prognosis evaluation, and prevention of colorectal cancer.展开更多
文摘Entering into the 1990s, Chinese scientists have made mice, drosophila and silkworm eggs experiments in space with satellites and achieved remarkable results. These animals were put in space environment units with the ability of adjusting pressure, temperature and moisture control, air conditioning and purifying as well as foods and water supply. After 8-days’ flight, all performance parameters were normal and met the design requirements. The two mice kept alive for 5 days and 10 hours
基金the Major Project of the Ministry of Science and Technology of Changsha,China(No.kh2003014)the Hunan Provincial Natural Science Foundation,China(Nos.2018JJ2584,2018JJ3507)+1 种基金the Beijing Municipal Science and Technology Comission,China(No.D171100002917004)the Guangxi Science and Technology Plan Project,China(No.AD16380019).
文摘This study aimed to evaluate the feasibility and safety of a novel stent manufactured by metal injection molding(MIM)in clinical practice through animal experiments.Vessel stents were prepared using powder injection molding technology to considerably improve material utilization.The influence of MIM carbon impurity variation on the mechanical properties and corrosion resistance of 316L stainless steel was studied.In vitro cytotoxicity and animal transplantation tests were also carried out to evaluate the safety of MIM stents.The results showed that the performance of 316L stainless steel was very sensitive to the carbon content.Carbon fluctuations should be precisely controlled during MIM.All MIM stents were successfully implanted into the aortas of the dogs,and the MIM 316L stents had no significant cytotoxicity.The novel intravascular stent manufactured using MIM can maintain a stable form and structure with fast endothelialization of the luminal surface of the stent and ensure long-term patency in an animal model.The novel intravascular stent manufactured using MIM demonstrates favorable structural,physical,and chemical stability,as well as biocompatibility,offering promising application in clinical practice.
基金Our study was funded by the Clinical Research Special Fund of Wu Jieping Medical Foundation(320.6750.2022-25-8)the Fundamental Research Funds for the Cornell University(2024-JYBXJSJJ042 and 2024-JYB-JBZD-058).
文摘Objective:To screen and identify the key active molecules,signaling pathways,and therapeutic targets of Shuxuening(SXN)injection for treating liver cirrhosis(LC)and to evaluate its therapeutic potential using a mouse model.Methods:Target genes of SXN and LC were retrieved from public databases,and enrichment analysis was performed.A proteineprotein interaction(PPI)network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins(STRING),and hub genes were identified using Molecular Complex Detection(MCODE).LC was induced in rats and mice via intraperitoneal injections of diethylnitrosamine and carbon tetrachloride(CCl4)for 12 weeks.Starting at week 7,SXN was administered intraperitoneally to the mice in the treatment group.Serum and liver tissues of the mice were collected for the detection of indicators,pathological staining,and expression analysis of hub targets using quantitative real-time polymerase chain reaction(qRT-PCR).Results:We identified 368 overlapping genes(OLGs)between SXN and LC targets.These OLGs were subsequently used to build a PPI network and to screen for hub genes.Enrichment analysis showed that these genes were associated with cancer-related pathways,including phosphoinositide-3-kinase/Akt and mitogen-activated protein kinase signaling and various cellular processes,such as responses to chemicals and metabolic regulation.In vivo experiments demonstrated that SXN treatment significantly improved liver function and pathology in CCl4-induced LC mice by reducing inflammation and collagen deposition.Furthermore,qRT-PCR demonstrated that SXN regulated the expression of MAPK8,AR and CASP3 in the livers of LC mice.Conclusion:This study highlighted the therapeutic effects of SXN in alleviating LC using both bioinformatics and experimental methods.The observed effect was associated with modulation of hub gene expression,particularly MAPK8,and CASP3.
基金We are grateful for the funding from the National Key Research and Development Program of China(grant No.:2016YFC1202203).
文摘Animal models are crucial for the study of severe infectious diseases,which is essential for determining their pathogenesis and the development of vaccines and drugs.Animal experiments involving risk grade 3 agents such as SARS CoV,HIV,M.tb,H7N9,and Brucella must be conducted in an Animal Biosafety Level 3(ABSL-3)facility.Because of the in vivo work,the biosafety risk in ABSL-3 facilities is higher than that in BSL-3 facilities.Undoubtedly,management practices must be strengthened to ensure biosafety in the ABSL-3 facility.Meanwhile,we cannot ignore the reliable scientific results obtained from animal experiments conducted in ABSL-3 laboratories.It is of great practical significance to study the overall biosafety concepts that can increase the scientific data quality.Based on the management of animal experiments in the ABSL-3 Laboratory of Wuhan University,combined with relevant international and domestic literature,we indicate the main safety issues and factors affecting animal experiment results at ABSL-3 facilities.Based on these issues,management practices regarding animal experiments in ABSL-3 facilities are proposed,which take into account both biosafety and scientifically sound data.
基金This research was supported by Meat and Livestock Australia grant P.PSH.1232,the Australasian Pork Research Institute Ltd grant 5A-113,The University of Queensland and The University of Western Australia.
文摘At a time when there is a growing public interest in animal welfare,it is critical to have objective means to assess the way that an animal experiences a situation.Objectivity is critical to ensure appropriate animal welfare outcomes.Existing behavioural,physiological,and neurobiological indicators that are used to assess animal welfare can verify the absence of extremely negative outcomes.But welfare is more than an absence of negative outcomes and an appropriate indicator should reflect the full spectrum of experience of an animal,from negative to positive.In this review,we draw from the knowledge of human biomedical science to propose a list of candidate biological markers(biomarkers)that should reflect the experiential state of non-human animals.The proposed biomarkers can be classified on their main function as endocrine,oxidative stress,non-coding molecular,and thermobiological markers.We also discuss practical challenges that must be addressed before any of these biomarkers can become useful to assess the experience of an animal in real-life.
文摘Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.
基金National Natural Science Foundation of China(No.81973747,81873299)Applied Technology Research and Development Program of Heilongjiang Province(No.GZ16C001)Traditional Chinese Medicine Science and Technology Project of Heilongjiang Province(No.ZHY2020-183).
文摘Schizophrenia,as a common mental disease,seriously threatens the physical and mental health of human beings.It is characterized by many mental and behavioral disorders,such as uncoordinated thinking and emotional mode which separated from the actual living environment.Patients with schizophrenia are prone to relapse and deterioration due to their long course of disease,resulting in the loss of labor force.It has been proved that the occurrence and development of schizophrenia is closely related to the abnormal development of oligodendrocytes,which have the function of myelin formation and the dysfunction of myelin sheath itself.For a comprehensive understanding of myelin abnormal effects on the pathogenesis of schizophrenia,this paper is to review the literature,then summarize and discuss the animal experimental literature related to the abnormal myelin sheath in schizophrenia from the perspectives of behavioristics,neuroimaging,protein expression and stereology,in order to further clarify the influence of the abnormal myelin sheath on the pathogenesis of schizophrenia and provide ideas for the diagnosis of schizophrenia and the research and development of new drugs.
基金supported by the National Natural Science Foundation of China(No.82174409 for Min Yao,No.82074454 for Xuejun Cui,No.81930116 for Yongjun Wang)Rising Star Project(22QA1409200 for Min Yao)+3 种基金Shanghai Natural Science Foundation(22ZR1461700 for Xuejun Cui)Shanghai Collaborative Innovation Center of Industrial Transformation of HospitalTCMPreparation(No.602092D for Min Yao)Combination of Medical and Nursing Care(No.602056D for Xuejun Cui)China Association of Traditional Chinese Medicine Youth Talent Promotion Project(No.CACM-2021-QNRC2-B23 for Min Yao).
文摘The animal experiment is the best method for therapeutic efficacy testing of various treatment methods before clinical application and serves as an irreplaceable“live reagent”and“live precise instrument,”thus playing a vital role in biomedical science research.However,there were significant differences between the results of animal experiments and clinical efficacy in previousfindings that are hard to ignore,especially in cerebrovascular accident research due to the unsatisfactory specification of animal experiments.Accordingly,more prescriptive and standard tools are required for evaluating the quality of animal experiments.This study will introduce the current commonly used quality evaluation tools for animal experiments.
文摘Introduction: Radiotherapy is often used to treat head and neck malignancies, with inevitable effects on the surrounding healthy tissues. We have reviewed the literature concerning the experimental irradiation of facial bones in animals. Materials and Methods: A PubMed search was performed to retrieve animal experiments on the irradiation of facial bones that were published between January 1992 and January 2012. The search terms were “irradiation facial bone” and “irradiation osteoradionecrosis”. Results: Thirty-six publications were included. The irradiation sources were Cobalt60, orthovoltage, 4 - 6 megavolt photons, and brachytherapy. The total dose varied between 8 - 60 Gy in single or multiple fractions. The literature presents a broad range of animal studies that differ in terms of the in vivo model, irradiation, observation period, and evaluation of results. Discussion: The different animal models used leave many questions unanswered. A detailed and standardized description of the methodology and results would facilitate the comparability of future studies.
文摘AIM To assess the feasibility and safety of a novel enteroscope,negative-pressure suction endoscope in examining the small intestine of a porcine model.METHODS In vitro experiments in small intestinal loops from 20pigs and in vivo experiments in 20 living pigs were conducted.RESULTS In in vitro experiments,a negative pressure of>0.06MPa was necessary for optimal visualization of the intestine,and this pressure did not cause gross or histological damage to the mucosa.For satisfactory examination of the small intestine in vivo,higher negative pressure(>1.00 MPa)was required.Despite this higher pressure,the small intestine did not show any gross or microscopic damage in the suctioned areas.The average time of examination in the living animals was 60±7.67 min.The animals did not experience any apparent ill effects from the procedure.CONCLUSION Small intestine endoscope was safely performed within a reasonable time period and enabled complete visualization of the intestine in most cases.
基金Funded by the National Natural Science Foundation of China (No.50872099)
文摘Titanium rods were processed into implant samples with cavity and groove in which was filled with HAP/β-TCP porous osteoconduction composite materials in order to increase the mechanical stability of the implant in vivo.The phase compositions of the composite was characterized by X-ray diffraction （XRD） and scanning electron microscopy（SEM）.Histological evaluation showed that the biogradable composite could enhanced the ability of new bone formation.The composite can conduct new bone tissue growing into the cavities gradually after implanted into animal,and then achieve mechanical fixation.The filling biogradable compound exhibited excellent biocompatibility,which combined with the new bone tissues tightly without inflammation and loosing.
基金supported by the National Major Project of Research and Development,No.2022YFA1105500(to SZ)the National Natural Science Foundation of China,No.81870975(to SZ)Innovation Program for Graduate Students in Jiangsu Province of China,No.KYCX223335(to MZ)。
文摘CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.
文摘This work used the cosmological neuroscientific concept of Soul of Multiverse for placing the problem of wildlife and biodiversity protection into a new philosophical environment where religious,scientific and philosophical approaches are in harmony.It resulted in the thought that the obligation of protecting wildlife and biodiversity on Earth,just as the sanctity of caring for all human lives,originated in cosmic laws set in the divine blueprints of the Soul of Multiverse.These laws seem to relay that in the 21st century the time has come on Earth to stop killing animals for food,to stop overhunting and overfishing,to stop industrial activities responsible for deforestation,desertification,air pollution and climate change,and to run animal experiments for science and medicine only in the extremely limited,most justified cases and only until new technologies make them no longer necessary.The conclusion was that to achieve these goals,new global governing mechanisms are needed.Specifically,the establishment of a Government of Earth,the next step of the political process that started with the United Nations in the first place,may be necessary to solve the global problems of wildlife and biodiversity protection since meaningful solutions for global problems require global governing mechanisms.
基金supported by the Natural Science Foundation of China (81000459)the Chinese Scholarship Council
文摘Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in N.mm^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in N.mm^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-innervation, but further functional measurements are still required.
基金Supported by Technology Innovation Youth Fund from Shandong Binzhou Animal Science and Veterinary Medicine(201102)
文摘A Bordetella hinzii strain, isolated from the lung of a dead breast-feeding infant rex rabbit with a respiratory infection, was used as study object to investigate its phenotypic and genetic characteristics. The strain could grow on MacConkey agar and was gram-negative, oxidase-positive, catalase-positive, short rodshaped, and it can produce alkali from malonate. Its 6S rRNA sequence was partially identical with B. hinzii （AF177667）. Animal experiments revealed nasal mucous hyperemia, tracheal congestion and bronchopneumonia in 28-day old rex rabbits. To sum up, this Bordetella hinzii isolate was deemed as a novel causative agent of respiratory disease in rex rabbit.
文摘Purpose: The purpose of this study was to develop a method for quantifying the extent of renal dysfunction due to drug-induced nephrotoxicity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate the protective effects of various antioxidant agents against cis-dichlorodiammineplatinum (cisplatin)-induced nephrotoxicity in rats using this method. Materials and Methods: The DCE-CT studies were performed in 8-week-old male Sprague-Dawley rats. The CT scanning started 4 s before a bolus intravenous injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 90 s at 1-s intervals. The contrast clearance per unit renal volume (K1) was estimated from the DCE-CT data using the Patlak model. The renal volume (V) was calculated by manually delineating the kidney on the CT image. The contrast clearance of the entire kid-ney (K) was obtained by . First, to investigate the effect of CA itself, the DCE-CT studies were performed without injecting cisplatin 2, 4, and 7 days after the first DCE-CT study on day 0. Second, to investigate the effect of injected dose of cisplatin, the DCE-CT study was performed after the intraperitoneal (i.p.) injection of cisplatin (1.8 mg/kg) and was repeated every other day for one week. Finally, to investigate the protective effects of antioxidant agents [L-arginine (300 mg/kg), N-acetylcysteine (500 or 1000 mg/kg), methimazole (40 mg/kg), captopril (60 mg/kg), and taurine (750 mg/kg)], the DCE-CT studies were performed on days 0, 2, 4, and 7 after the i.p. injection of cisplatin (3.6 mg/kg). For comparison, the DCE-CT data were also acquired without injecting the antioxidant agents (CDDP group). Results: When cisplatin was not injected, there were no significant changes in the K value as compared to that on day 0 within the studied period. The K valuesignificantly (p < 0.05) decreased with increasing dose of cisplatin. Although some differences were observed in the extent of change in the K value normalized by that on day 0, depending on the antioxidant agents and their injected dose and schedule, the normalized K values on day 7 in the groups injected with the antioxidant agents were significantly higher than those in the CDDP group, suggesting that the antioxidant agents studied here had protective effects against cisplatin-induced nephrotoxicity in varying degrees. Conclusion: Our method appears useful for quantitatively evaluating the protective effects of antioxidant agents against cisplatin-induced nephrotoxicity and for investigating the optimal injected dose and schedule of the agents, because it allows repeated measurements of split renal function in a single animal.
文摘Objective To investigate the feasibility of magnetic resonance （MR） diffusion weighted imaging （DWI） for evaluation of radiotherapeutic effects on rabbit VX2 tumor model. Methods Sixteen New Zealand white rabbits received a subcutaneous implantation of VX2 tumor cell suspension 0.5 mL （4× 10^7 ceUs/mL） in their right thighs to set up tumor model. And 2 weeks later they were randomly divided into therapy group （Group T, n = 10） and control group （Group C, n = 6）. Group T received radiotherapy at a single dose of 10 Gy. MR imaging （MRI） scan including short TI inversion recovery echo-planar imaging DWI, T1-weighted imaging （T1WI） and T2-weighted imaging （T2WI） sequences were performed 1 day prior to as well as 1 day, 2 days, 3 days and 7 days after radiotherapy. Group C received only MRI scan at the same time points without any treatment. MRI appearance on T2WI, TlWI, and DWI images was compared and tumor volume was calculated. Apparent diffusion coefficient （ADC） values of the tumor were evaluated in all cases. HE staining was used for pathological study. Results Necrosis （n = 8） and hemorrhage （n = 2） were seen gradually on T2WI and T1WI images of Group T after time point of day 2 after irradiation. In Group C, no obvious necrosis was found until day 7. There was no significant difference in tumor volume between the two groups before radiotherapy. After radiotherapy, tumors in Group T showed a gradual growth but not as obvious as Group C. There was a significant difference in tumor volume between the two groups from day 2 on （P 〈 0.05）. ADC value changed dramatically fight from the 1st day after radiotherapy in Group T [（0.99 ± 0.15） ×10^-3 mm^2/s for 1 day before radiotherapy, （1.23 ± 0.08） ×10^-3 , （1.45 ± 0.07） ×10^-3 , （1.63 ± 0.06） ×10^-3 , and （2.02 ± 0.18） ×10^-3 mm^2 for day 1, 2, 3, and 7]; and ADC value had no significant changes after radiotherapy in Group C except day 7 [（1.07±0.08） ×10^-3 mm^2 for 1 day before radiotherapy, （1.03 ± 0.04）×10^-3 , （1.05 ± 0.02）×10^-3 , （1.05 ± 0.05） ×10^-3 , and （0.95 ± 0.07） ×10^-3 mm^2 for day 1, 2, 3, and 7]. There was significant difference in ADC value between the two groups for each time point after radiotherapy （P 〈 0.01）. Pathological study showed that the number of viable tumor cells in Group T decreased 1 day after radiotherapy, and the inflammatory cell infiltration was marked and almost all viable tumor cells disappeared by day 7 after radiotherapy. Conclusions DWI is a new promising technique for monitoring radiotherapy outcomes. ADC value may give a prior clue on physiological changes of radiotherapy before routine MRI could tell.
文摘Brain diseases, including brain tumors, neurodegenerative disorders, cerebrovasculardiseases, and traumatic brain injuries, are among the major disordersinfluencing human health, currently with no effective therapy. Due to the lowregeneration capacity of neurons, insufficient secretion of neurotrophic factors,and the aggravation of ischemia and hypoxia after nerve injury, irreversible lossof functional neurons and nerve tissue damage occurs. This damage is difficult torepair and regenerate the central nervous system after injury. Neural stem cells(NSCs) are pluripotent stem cells that only exist in the central nervous system.They have good self-renewal potential and ability to differentiate into neurons,astrocytes, and oligodendrocytes and improve the cellular microenvironment.NSC transplantation approaches have been made for various neurodegenerativedisorders based on their regenerative potential. This review summarizes anddiscusses the characteristics of NSCs, and the advantages and effects of NSCs inthe treatment of brain diseases and limitations of NSC transplantation that need tobe addressed for the treatment of brain diseases in the future.
基金Supported by Natural Science Foundation of Minhang District of Shanghai,No.2012MHZ001
文摘AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model was established. Fortytwo female FVB/N mice were randomly divided into the following three groups: group 1(10 mice, negative control) was treated with vehicle, group 2(16 mice, positive control) was treated with AOM plus vehicle, and group 3(16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci(ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16 S r RNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16 S r RNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTS Treatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS(5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85%(33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the diversity of gut microbiota increased, potential carcinogenic bacteria such as Bacteroides were enriched, and the abundance of butyrate-producing bacteria(Clostridiaceae, Ruminococcus, etc.) decreased continuously. In contrast, the structure of gut microbiota was relatively stable during the intervention of EGCG on colon carcinogenesis. Enrichment of probiotics(Bifidobacterium, Lactobacillu, etc.) might be a potential mechanism for EGCG's effects on tumor suppression. Via bioinformatics analysis, principal coordinate analysis and cluster analysis of the tumor formation process, we found that the diversity of gut microbiota increased in the tumor model group while that in the EGCG interfered group(EG) remained relatively stable.CONCLUSION Gut microbiota imbalance might be a potential mechanism for the prevention of malignant transformation by EGCG, which is significant for diagnosis, treatment, prognosis evaluation, and prevention of colorectal cancer.
