Abstract: Objective The vertebrate model of zebrafish (Danio rerio) was employed to explore the effects of hypoxia on early embryonic development, hematopoietic differentiation, and erythroid differentiation. Methods At 12h post-fertilization, zebrafish embryos were randomly divided into two groups. The normoxic group was used as the control group, and the hypoxic group was used as the experimental group. The morphological changes of zebrafish embryos were observed in real-time. Erythropoiesis and morphological changes were observed by benzidine, O-dianisidine, acridine orange, and May-Grunwald Giemsa staining. Real time PCR was used to analyze hematopoietic gene expression in zebrafish embryos. Results Hypoxia reduced nutritional consumption of the yolk sac, inhibited the formation of pigment cells, slowed down the heart rate, and delayed the hatching of zebrafish embryos. Inhibitive effects of hypoxia on the production and maturity of red blood cells were observed. Conclusions Hypoxia delays zebrafish embryonic development and inhibits the production and maturity of red blood cells.

Abstract: Objective The aim of this study was to evaluate the application of ultrasound and high-resolution magnetic resonance imaging (HRMRI) in a rabbit carotid atherosclerosis (AS) model, providing technical method for the diagnosis and evaluation of preclinical atherosclerotic plaques. Methods Eighteen male Japanese white rabbits were randomly divided into two groups (n= 9). The model group was fed a high-cholesterol diet for 2 weeks followed by balloon injury to the right carotid artery. After surgery, high-fat feeding was continued for 6 weeks to establish a rabbit carotid AS model. The NC group was fed regular feed for 8 weeks. At 4 and 8 weeks after modeling, plasma total cholesterol (TC) and triglyceride ( TG) levels were measured, and the carotid artery was examined via ultrasound. Carotid HRMRI was performed at 8 weeks. After euthanasia, the right common carotid artery was taken for HE and oil red “O” staining to assess carotid artery atherosclerotic lesions. Results Compared with the findings in the NC group, TC levels were significantly higher in the model group at 4 weeks after modeling, and body weight and TC and TG levels were significantly higher in the model group at 8 weeks. The result of ultrasound revealed that intima-media thickness ( IMT), the stenosis rate, the maximum systolic blood flow velocity, and the vascular resistance index of the right common carotid artery increased significantly in the model group with the deepening of the lesions, and stenosis and plaque formation were observed. In addition, the HIMRI result disclosed obvious stenosis of the right common carotid artery compared with findings in the NC group, and the model group displayed obvious atherosclerotic plaque formation and a significantly higher stenosis rate. Histopathology further confirmed the obvious atherosclerotic plaque formation in the common carotid artery in the model group, and IMT, the stenosis rate, and lipid content were significantly higher in the model group than in the NC group. In addition, correlation analysis demonstrated that the quantitative result of ultrasound, HRMRI, and HE staining were significantly correlated. Conclusions Both ultrasound and HRMRI technology can non-invasively detect and diagnose lesions in a rabbit carotid AS model, but HRMRI can more clearly and intuitively judge the severity of vascular stenosis and atherosclerotic plaques.

Abstract: Objective Based on the TLR4 / MYD88 signaling pathway to study the protective effect of Dahuang Mudan Decoction on the rat model of acute pancreatitis ( AP ) made by retrograde pancreaticobiliary duct injection. Methods 96 Wistar rats (SPF grade) were divided into: sham operation group, AP model observation group, octreotide positive control group, Dahuang Mudan Decoction high, medium and low dose groups according to the random number table method . Except for the sham operation group, which was injected by retrograde with normal saline through the pancreaticobiliary duct, the other groups were modeled by retrograde injection of 5% sodium taurocholate solution through the pancreaticobiliary duct, followed by drug intervention for 6 days. To observe the general living conditions of rats, to measure the contents of serum amylase (AMS), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), The expression levels of TLR4, MyD88, IRAK-4 and IRAK-4 were detected by RT-PCR, Westen Blot and IHC, and the contents of IL-2, iNOS and IFN-γ were detected by ELISA. Results (1) Compared with the sham operation group, the rats in the AP model observation group had a relatively poor general survival condition, a significant increase in serum amylase (AMS), alanine aminotransferase (ALT), glutamic oxaloacetase (AST). Under the microscope, the pancreatic tissue structure was scattered, necrosis and congestion were serious. The expression levels of TLR4, MyD88, IRAK-2 and IRAK-4 gene protein in pancreatic tissue were significantly increased, and the contents of IL-2, iNOS and IFN-γ in pancreatic tissue homogenate were significantly increased (P< 0. 05). (2) After intervention, the general living conditions of the rats in the treatment group were improved in different degrees, serum amylase (AMS), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were decreased, interstitial edema and necrotic foci were significantly improved under the microscope, the expression levels of TLR4, MyD88, irak-2 and IRAK-4 gene protein in pancreatic tissue were decreased, and the contents of IL-2, iNOS and IFN-γ in pancreatic tissue homogenate were decreased, especially in the large dose group of Dahuang Mudan decoction, the difference was statistically significant (P< 0. 05). Conclusions Dahuang Mudan decoction can improve pancreatic injury in rats with acute pancreatitis, and its mechanism may be related to the inhibition of TLR4 / MyD88 signaling pathway.

Abstract: Objective A rat model of acute lung injury (ALI) was established by intratracheal instillation of lipopolysaccharide (LPS) and changes in the lung injury were observed at various periods. Methods Thirty-two healthy Sprague-Dawley (SD) rats were randomly divided into normal (n= 8) and model (n= 24) group. In accordance with the duration of LPS infusion, the model group was divided into three subgroups: 3, 6 and 12 h groups, with eight rats in each group. The ALI rat model was established by tracheal instillation of LPS ( 2 mg / kg). Observations included the general performance of rats, gross observation of lungs, detection of lung functions, calculation of the lung wet / dry weight ratio, detection of interleukin ( IL) - 1β, IL-8, and tumor necrosis factor - α in bronchoalveolar lavage fluid, detection of malondialdehyde and superoxide dismutase in lung tissue, and histomorphological observation by hematoxylin-eosin staining in lung tissue. Changes of acute lung injury were also evaluated at different stages. Results After modeling, the survival rate of rats in the model group was 100%. Compared with the normal group, the general performances of rats in the 3 h group were similar with less food intake, less activity, more mucus secretions in the nasal cavity, faster respiratory frequency, and audible wheezing. Gross observation of the lungs showed liver-like degeneration of the lung tissue in the left and right hilum of the lung in the 3 h group, bleeding spots were scattered on the left and right lobes, and the bleeding site was bright red. The pulmonary functions of rats after LPS exposure for 3 h showed significant decreases in the forced expiratory volume (FEV) in 0. 1 s, forced expiratory volume in 0. 3 s, ratio of forced expiratory volume in 0. 1 s to forced vital capacity, and ratio of forced expiratory volume in 0. 3 s to forced vital capacity (P< 0. 05,P<0. 01). The wet / dry weight ratio was increased significantly ( P< 0. 01). The contents of IL-1β, IL-8, and tumor necrosis factor - α in bronchoalveolar lavage fluid were increased significantly ( P< 0. 01). The content of malondialdehyde was increased significantly (P< 0. 01). The content of superoxide dismutase was decreased significantly (P<0. 01). Hematoxylin-eosin staining showed obvious thickening of the alveolar septum, pulmonary interstitial edema, and erythrocyte exudation. Conclusions Tracheal instillation of LPS causes significant decreases in lung functions, severe pulmonary inflammation, an oxidation-antioxidation imbalance, and severe pulmonary edema in rats, which lead to acute lung injury. Furthermore, it is more beneficial to establish an ALI rat model at the 3 h time point.

Abstract: Objective To investigate the role of p53 gene in neurobehavior activities and effects on the number of neurons of barrel cortex in mice. Methods A total of 45 8 ~ 12 weeks old p53 knockout ( KO) mice with C57BL/ 6 background and 38 wild-type (WT) mice of the same age and background were included as the experimental group and the control group, respectively. The open-field test, Y-maze test and texture discrimination task were used to evaluate anxiety- like behavior, locomotor activity, working memory and whisker sensitivity in mice. Nissl staining was used to observe changes in neuronal numbers in layer II/ III of barrel cortex. Results Compared with WT mice, p53 KO mice did not show any significant difference in the time spent in the center (P> 0. 05) or total distance moved (P> 0. 05) of the open field apparatus, the percentage of spontaneous alternations (P> 0. 05), and the numbers of arms entries (P> 0. 05) in the Y-maze test. However, the percentage of time exploring objects with novel texture was significantly decreased (P< 0. 01). The number of neurons in layer II/ III of barrel cortex of p53 KO mice was significantly reduced compared with that of WT mice (P< 0. 01). Conclusions Deletion of p53 gene did not lead to anxiety-like behavior in mice. Moreover, locomotor activity and working memory were not affected by p53 deletion. However, p53 deletion impacted the ability to discriminate novel textures, that is, whisker sensitivity, which may be related to the decreased number of neurons in layer II/ III of the barrel cortex.

Abstract: Objective This study observed the effects of Sishen pills on the pathological characteristics of colon tissue in spleen and kidney yang deficiency ulcerative coliti model rats and expression of PI3K/ Akt / mTOR signaling pathway-related proteins to explore possible mechanisms of inflammation in an ulcerative colon. Methods A total of 120 SPF Wistar rats (half male and half female) were randomly assigned to a blank group of 20, and the other 100 rats were used as the model group. The rat model of ulcerative colitis with spleen-kidney Yang deficiency was established by DNBS / ethanol solution enema + hydrocortisone subcutaneous injection + senna leaf gavage. Rats with successful model establishment were randomly divided into five groups: model, mesalazine, Sishen pill high, Sishen pill medium, and Sishen pill low dose groups. Model and blank groups were administered distilled water. The mesalazine group was orally administered 0. 36 g / kg mesalazine, and the high, middle and low dose groups of Sishen pills were orally administered 3. 2, 1. 6, and 0. 8 g / kg crude drug. Respectively, the volume of which was 10 mL/ kg. Once a day for 21 d, colon tissues of rats were collected to observe general morphology and colon injury. HE staining was used to observe pathological changes. Immunohistochemistry was used to observe the localization and expression levels of PI3K p85, p-PI3K p85, AKT, p-AKT Ser473, mTOR, and p-mTOR Ser2448 proteins in colon tissues. Results Compared with the blank group, the intestinal mucosa had disappeared partially, glands had disappeared, and a large number of inflammatory cells had infiltrated and accumulated in mucosal and basal layers in pathological sections of the model group. The expression of PI3K p85, p-PI3K p85, AKT, p-AKT Ser473, mTOR, and p-mTOR Ser2448 proteins in the model group was increased significantly (P< 0. 01). Compared with the model group, inflammatory cells in the drug groups were reduced, and the structure of the mucosal layer returned to normal to varying degrees. Mesalazine and Sishen pill medium dose groups had the best effects, and the mucosal structure was close to that in the blank control group. Inflammatory cells in the low dose group of Sishen pill were slightly reduced, and a small number of glandular structures was seen. The expression of PI3K p85, p-PI3K p85, AKT, p-AKT Ser473, mTOR, and p-mTOR Ser2448 proteins was decreased to varying degrees in high, middle, low dose groups of Sishen pill and the mesalazine group (P< 0. 01, P< 0. 05). Conclusions Sishen pill may improve intestinal mucosal damage of ulcerative colitis model rats with spleen and kidney yang deficiency by inhibiting activation of the PI3K/ Akt / mTOR signaling pathway.

Abstract: Objective The breeding and identification method of Bmal1 knockout mice were analyzed to provide an ideal animal model to study various biological rhythms. Methods Bmal1 knockout mice were fed and bred in cages of one male and two females. Tail genomic DNA of the mice was extracted from the offspring, the target gene fragment was amplified by PCR, and the PCR product was analyzed by gel electrophoresis. Bmal1 protein expression in myocardial tissue was detected by Western Bolt to verify the Results. Results Compared with those of Bmal^{+ / +} mice, the phenotypes of Bmal^{- / -} mice showed no significant difference except for body weight, and homozygous knockout mice lost their reproductive ability. Changes in 24 h blood glucose rhythm of Bmal^{- / -} mice. Bmal1 knockout mice were successfully bred, and a batch of knockout mice was obtained. Conclusions PCR identified homozygous mice with Bmal1 gene knockout. PCR amplification was an effective method to detect the mouse gene.

Abstract: Objective To establish and evaluate a human flora-associated ( HFA) mouse model from patients with Alzheimer’ s disease (AD) via fecal microbiota transplantation. Methods Twenty-eight female germ-free (GF) C57BL/ 6J mice were divided into a healthy control CON group and an AD group. Six-week-old mice were orally inoculated with a 0. 4 mL mixed stool suspension from 3 healthy participants CON or 3 AD patients to establish the HFA mouse model. At 6 and 10 weeks post-inoculation, fresh fecal samples were collected and examined for the V3 region of the 16S rDNA gene. Blood sera were collected and examined for Aβ and cytokine levels. Brain samples were collected, processed and stained with immunohistochemistry (IHC) for pathological examination. Results There was no difference in average body weight between the two groups. Alpha-diversity analysis showed that the Simpson’s Diversity Index (P< 0. 05, P< 0. 01) was significantly lower in the AD group than CON group. At 6 and 10 weeks post-inoculation, the abundance-based coverage estimator (P< 0. 05), Chao1 index (P< 0. 05) and Shannon function (P< 0. 05, P< 0. 01) were higher in the AD group than the CON group. At the family level at 6 and 10 weeks post-inoculation, the relative abundances of Bacteriaceae were higher (P< 0. 01, P< 0. 05), while those of Lachnospiraceae (P< 0. 001) and Peptostreptococcaceae (P< 0. 05, P< 0. 01) were lower in the AD group compared with the CON group. At the genus level, Bacteroides (P< 0. 01, P< 0. 05) were higher in the AD group the AD group than the CON group. The relative abundances of Clostridioides (P< 0. 01, P< 0. 05), Lachnoclostridium (P< 0. 01, P< 0. 0001) and Parasutterella (P< 0. 01, P< 0. 001) were lower in the AD group than the CON group. β-diversity analysis showed that the CON and AD groups were distributed in different quadrants, but the same groups at different stages were distributed in the same quadrants, with a significant difference between the groups ( P< 0. 05). The Aβ40 level in serum ( P< 0. 05) and cerebral homogenates ( P< 0. 01) were significantly higher in the AD group than the CON group at 10 weeks post-inoculation. In the AD group, the interleukin (IL) - 1β level was lower at 6 weeks ( P< 0. 05), the IL-10 level was higher at 10 weeks ( P< 0. 01), and the transforming growth factor-β level was lower at 6 weeks (P< 0. 01) post-inoculation post-inoculation compared with the CON group. Pathological examination using IHC staining of the brain showed no senile plaques. Conclusions An HFA mouse model derived from AD patients was established via fecal microbiota transplantation. The main advantage of using bacteria from AD patients was that the GF mice were well colonized.

Abstract: Objective This study evaluated the lipid-lowering effect of adding citrus polymethoxyflavonoid powder to biscuits through measurement of lipid metabolism indicators in a hyperlipidemia mouse model to develop a new type functional food. Methods Sixty male KM mice were randomly divided into six groups and fed for 6 weeks to establish a high fat mouse model. Then, they were fed with the corresponding biscuits. After 6 weeks of feeding, the weight, Lee’ s index, serum lipid levels, and indexes of the liver, spleen, heart, and kidney were assessed. Results After 6 weeks, polymethoxyflavonoid biscuits inhibited the weight increase of hyperlipidemia mice and reduced hyperlipidemia. Polymethoxyflavonoid biscuits significantly improved abnormal lipid metabolism of common biochemical indicators in the serum of hyperlipidemia model mice. In terms of the effect of lipid-lowering biscuits on blood lipids in mice, the lipid- lowering biscuits had a significant effect on triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), but had no obvious effect on high-density lipoprotein cholesterol (HDL-C). Conclusions Citrus polymethoxyflavonoid powder may be a therapeutic agent for dyslipidemia, fatty liver, and other related diseases.

Abstract: Objective To study the effects of dopamine D1-like receptor ( D1DR) on the development of flickering light-induced myopia ( FLM) in guinea pigs and preliminarily explore the potential pathogenesis of FLM. Methods Thirty-six 2-week-old guinea pigs were randomly assigned to four groups ( n= 9): Control, FLM, FLM + Vehicle, and FLM+D1DR antagonist ( SCH 23390) groups. The refraction and axial length (AL) were measured before and after treatments. Expression of retinal D1DR was detected by immunohistochemistry and western blotting after 6 weeks of treatment. High performance liquid chromatography with electrochemical detection was used to detect the levels of DA and its primary metabolite (DOPAC) in the retina. Results Compared with those in the Control group, guinea pigs in the FLM group showed a significant myopic refractive shift and AL elongation (P< 0. 001), higher retinal D1DR expression (P< 0. 05), higher retinal DA levels, and a lower retinal DOPAC/ DA ratio (P< 0. 001). However, the increases of myopia (P< 0. 001) and AL (P< 0. 05) were significantly smaller in guinea pigs of the FLM+SCH 23390 group than in those of the FLM group. Additionally, lower retinal DA levels (P< 0. 001) and a higher retinal DOPAC/ DA ratio (P< 0. 05) were found in the FLM + SCH 23390 group than in the FLM group. Conclusions D1DR is involved in the development of FLM in guinea pigs. Blocking D1DR with SCH 23390 may suppress the development of FLM in guinea pigs, which might play an important role by influencing retinal DA levels and its metabolism.

Abstract: Objective To screen the conditions of a chronic thrombus mouse model after injecting a carrageenan solution at various concentrations intraperitoneally. Methods Seventy ICR male mice were randomly divided into seven groups with 10 mice in each group: blank ( control), 0. 02%, 0. 04%, 0. 06%, 0. 08%, 0. 10%, and 0. 20% groups. Mice in the blank group were intraperitoneally injected with normal saline (0. 01 mL/ g), whereas mice in the other groups were intraperitoneally injected with carrageenan solutions at the corresponding concentration (0. 01 mL/ g) once a day. Mice in each group kept at (20 ± 1)°C and had free access to food and water. The black-tailed conditions (black-tailed rate and length) of each group were observed each day. An outlet plug was used for sampling. Blood samples were collected to detect blood clots, and indicators of oxidative stress and inflammatory factors in colon tissues and plasma were detected. Results In the 0. 06% dose group, two mice were thrombotic on 5 d and eight mice were thrombotic on day 6. Compared with the blank group, FIB content in the 0. 06% dose group was increased significantly ( P< 0.05), APTT was shortened significantly (P< 0.05), TT was prolonged significantly (P< 0.05), and PT was prolonged significantly (P< 0.01). SOD and GSH-Px in colon tissue and plasma of the 0. 06% dose group were decreased significantly (P< 0.01), and MDA was increased significantly (P< 0. 05). The colon tissue and plasma levels of TNF-α and IL-1β in the 0. 06% dose group were increased significantly (P< 0.05), and those of IL-10 were decreased significantly (P< 0.05). Conclusions A 0. 06% carrageenan solution (0.01 mL/ g) injected intraperitoneally for 6 d ( once a day) at (20 ± 1)°C is the optimal condition to establish a mouse model of chronic thrombosis.

Abstract:Sarcopenia is considered to be the phenomena of decreases in muscle mass and strength with age. In recent years, animal models of sarcopenia have been widely used to examine the prevention and mechanisms of muscle atrophy during aging. This article reviews the animal models of sarcopenia, mainly discusses the establishment and application of animal models of sarcopenia, and provides a basis to carrying out relevant experiments.

Abstract:Metabolic and endocrine diseases are major diseases that endanger human health and reduce quality of life. Obesity, virus infection, genetic susceptibility, and abnormal immune functions can lead to metabolic and endocrine diseases, but the pathogenesis remains unclear. The preparation of suitable animal models is important for research. Miniature pigs are very similar to humans in terms of physiological and anatomical structures, metabolic processes, and pathological diagnosis indexes. Therefore, they are an ideal animal to model endocrine and metabolic diseases. This article reviews miniature pig strains and the method and current situation of disease model establishment to provide a reference for animal model research of human endocrine and metabolic diseases.

Abstract:Influenza is a highly contagious acute respiratory infectious disease, which has a wide prevalence and high morbidity. Aggressive innate immune responses often induce a cytokine storm, which is associated with elevated levels of inflammatory cytokines, causing lung damage and failure. Severe pneumonia is one of the major causes of death of influenza patients. Currently, the drugs that are clinically used for influenza treatment are mainly antiviral drugs. However, these drugs usually cannot regulate the excessive immune response of the body or reduce lung damage. IL-37, a member of the IL-1 family, has a strong anti-inflammatory function. By inhibiting the secretion of a variety of inflammatory cytokines, IL-37 prevents the occurrence of cytokine storms and plays an important role in infectious diseases, autoimmune diseases and tumors. Therefore, if the anti-inflammatory effects of IL-37 can be applied to the treatment of severe pneumonia caused by H1N1 influenza virus infection, this strategy will undoubtedly provide new directions for the treatment of patients with severe pneumonia.

Abstract:Calcium is an important messenger in mammalian nerve cells. It mediates a variety of intracellular signal transduction pathways and plays an important role in regulating neuronal functions. Calcium signaling performs its highly specific functions in a defined subregion of the cell, especially in the cortex. Detection of calcium signals in neurons is particularly important to study neuronal functions. In this article, we review the method of detecting calcium signals in model animals. The common method include two-photon calcium imaging technology, deep brain microscopic calcium imaging technology, and optical fiber recording technology. Through a literature review and analysis, new developments in this field are presented. We also discuss the prospects of calcium signal detection to study cortical neuronal signals and plasticity in various animal models.

Abstract:In recent years, the role of intestinal microorganisms in human health and diseases has been widely researched. The application of a germ-free animal model in intestinal microecology is extensive and this model provides a very effective research tool for human physiological and pathological research. To ensure the quality of experimental animals, aseptic tests must be frequently performed. However, sterility tests are affected by many factors. At present, the traditional detection method are mainly bacterial and fungal culture and Gram staining. With the development of high- throughput sequencing, polymerase chain reaction method have been used to identify bacteria using 16S rRNA. However, these method have some limitations. In this paper, we discuss the advantages and disadvantages of these method and the influencing factors.

Abstract:Plasma cell mastitis ( PCM) is a common breast disease, with an incidence rate that continues to increase. The main pathological changes of PCM were in middle-aged non lactation women. The clinical manifestations and pathological changes of PCM are complex, and the treatment method are also diverse. At present, most studies on PCM mainly focus on clinical observation and research; however, the pathological process and pathogenesis are not completely clear, and basic research in PCM is insufficient. Therefore, the preparation of animal models of PCM is of great significance for study of the molecular mechanism and evaluation of therapeutic method for PCM. In this paper, PCM animal model types, animal model preparation method , model pathology and result were reviewed. This review will help lay a theoretical foundation for follow-up research for PCM.

Abstract:Campylobacter jejuni can cause foodborne gastrointestinal diseases and has an important impact on human health. However, establishment of a mouse infection model is currently an obstacle for research of this bacterium. This article reviews the key factors that affect the establishment of the C. jejuni infection model, including strain virulence factors, mouse breeds, immune function, intestinal flora, diet composition and host adaptation, among others, in order to provide a reference for the successful establishment of a suitable mouse infection model.

Abstract:With the increasing global prevalence of metabolic syndrome, the prevalence of non-alcoholic fatty liver disease (NAFLD) has also risen sharply. NAFLD is the most common chronic liver disease in the world and includes simple steatosis and non-alcoholic fatty hepatitis ( NASH), advanced fibrosis, cirrhosis and hepatocellular carcinoma. NASH is an important stage from simple steatosis to fibrosis, cirrhosis and liver cancer. Therefore, the prevention and treatment of NASH has become an important research focus. Animal models are critical tools for studying the pathogenesis of diseases, research and development of therapeutic drugs, and formulating prevention and treatment strategies. The animal models that have been developed so far for NASH mainly simulate the pathological morphology and clinical characteristics of human NASH. These models include dietary animal models, drug-induced animal models and genetically modified animal models, and each model has its own advantages and disadvantages. In this paper, we review the research and applications of NASH animal models for NASH research.