Experimental models of high-risk bowel anastomosis in rats:A systematic review

BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.

How dopamine tunes parvalbumin interneurons in the hippocampus:new experimental observations in Alzheimer's disease

Despite decades of dedicated resea rch,Alzheimer's disease (AD) is an age-related and progressive neurodegenerative disorder for which the mechanisms of onset are sti unc ear.AD is cha racterized by featured histological alterations including amyloid-beta (AB) plaque deposition,accumulation of neurofibrillary to ngles of hyperphosphorylated-tau,and neuronal loss,accompanied by progressive cognitive decline and behavioral changes.

Biochemical Liver Functions and Molecular Identification of Fasciola hepatica from Experimentally Infected Rat Model

The current study was performed to evaluate the liver function status as well as molecular characterization of the recovered worms in rats experimentally infected with F. hepatica. Sixteen male Wister rats aged 30 days were randomly allocated into two groups (n = 8). The first group was infected orally with 15 viable encysted metacercaria of F. hepatica per animal. The other group was kept non-infected (control group). At zero time (before infection), the 2nd, 4th, 6th, 8th, 10th, 12th and 14th weeks post-infection (WPI), blood and serum samples were collected via puncture of retro-orbital plexus of veins from each rat. Serum enzyme level (AST and ALT) and total protein were measured, and the serum protein profile was carried out using agarose gel electrophoresis. During the period of the experiment, serum ALT and AST activities and serum total globulins significantly increased while serum total proteins and albumin markedly decreased in the infected group. On the 14th WPI, the data of the electropherogram showed that globulin fractions (α1-, β- and γ-globulin) levels were significantly increased while α2-globulin was markedly decreased in the infected group. The molecular analysis confirmed the amplification of the ITS1, ITS2 and NDI genes of F. hepatica recovered from the infected liver of rats with amplicon sizes of 630, 510 and 560 bp, respectively. Sequencing of the amplified ITS gene resulted in the determination of 3 strains (PP108836, PP108837, and PP108838). Also, analysis of the ITS2 gene resulted in obtaining 3 isolates under the accession numbers (PP109065, PP109066, and PP109067). In conclusion, fasciolosis in the rat model is suitable for routine experimental infections and caused a pronounced liver dysfunction with discharging of the Fasciola eggs in the faeces and the development of adult stages in the bile ducts. Furthermore, molecular techniques are a sensitive tool for the identification and characterisation of the Fasciola parasite.

Sodium-glucose cotransporter-2 inhibitors protect tissues via cellular and mitochondrial pathways:Experimental and clinical evidence

Mitochondrial dysfunction is a key driver of cardiovascular disease(CVD)in metabolic syndrome and diabetes.This dysfunction promotes the production of reactive oxygen species(ROS),which cause oxidative stress and inflammation.Angiotensin II,the main mediator of the renin-angiotensin-aldosterone system,also contributes to CVD by promoting ROS production.Reduced activity of sirtuins(SIRTs),a family of proteins that regulate cellular metabolism,also worsens oxidative stress.Reduction of energy production by mitochondria is a common feature of all metabolic disorders.High SIRT levels and 5’adenosine monophosphate-activated protein kinase signaling stimulate hypoxia-inducible factor 1 beta,which promotes ketosis.Ketosis,in turn,increases autophagy and mitophagy,processes that clear cells of debris and protect against damage.Sodiumglucose cotransporter-2 inhibitors(SGLT2i),a class of drugs used to treat type 2 diabetes,have a beneficial effect on these mechanisms.Randomized clinical trials have shown that SGLT2i improves cardiac function and reduces the rate of cardiovascular and renal events.SGLT2i also increase mitochondrial efficiency,reduce oxidative stress and inflammation,and strengthen tissues.These findings suggest that SGLT2i hold great potential for the treatment of CVD.Furthermore,they are proposed as anti-aging drugs;however,rigorous research is needed to validate these preliminary findings.

A Review of Experimental Research on the Mode I Fracture Behavior of Bamboo

Bamboo is an eco-friendly material with light weight,high strength,short growth cycle and high sustainability,which is widely used in building structures.Engineered bamboo has further promoted the development of modern bamboo structures due to its unrestricted size and shape.However,as a fiber-reinforced material,fracture damage,especially Mode I fracture damage,becomes the most likely damage mode of its structure,so Mode I fracture characteristics are an important subject in the research of mechanical properties of bamboo.This paper summarizes the current status of experimental research on the Mode I fracture properties of bamboo based on the three-point bending(TPB)method,the single-edge notched beam(SENB)method,the compact tension(CT)method and the double cantilever beam(DCB)method,compares the fracture toughness of different species of bamboo,analyzes the toughening mechanisms and fracture damage modes,discusses the applicability of different theoretical calculation methods,and makes suggestions for future research priorities,aiming to provide a reference for future research and engineering applications in related fields.

Experimental study on the synergistic inhibition of malignant biological behavior of hepatocellular carcinoma cells by the combination of DMDD and sorafenib

Objective:To investigate the effects and possible mechanisms of the combination of DMDD(2-dodecyl-6-methoxycyclohexa-2-5-diene-1-4-dione),a traditional Chinese medicine monomer,and sorafenib on the malignant biological behavior of human hepatocellular carcinoma Huh7 cells.Methods:The experiment was divided into four groups:Huh7 cells control group,DMDD group,sorafenib group and DMDD and sorafenib combination group.The CCK-8 assay was used to measure the viability of Huh7 cells,and the Kim's formula was used to determine the synergistic effect.The plate cloning experiment was conducted to test colony formation ability of Huh7 cells.The scratch and Transwell experiments were performed to evaluate the migration ability and the invasion ability of Huh7 cells.The cell cycle of Huh7 cells was detected by flow cytometry.RT-qPCR and Western blot were used to measure the mRNA transcription level and protein expression level of PHGDH in the serine synthesis pathway.Results:The plate cloning experiment,scratch experiment,and Transwell migration experiment showed that the combined application of DMDD and Sorafenib significantly enhanced the inhibitory effect on the proliferation,migration,and invasion ability of Huh7 cells compared to the control group,DMDD group,and Sorafenib group(P<0.05).According to the Kim's formula,the combination of DMDD(final concentrations of 2,4,8μmol/L)and Sorafenib(final concentrations of 1,2,4μmol/L)had a synergistic inhibitory effect on the proliferation of Huh7 cells(Q>1.15).6,10μmol/L DMDD combined with 3,5μmol/L Sorafenib showed additive effect.The cell cycle of Huh7 cells was detected by flow cytometry,and the results showed that after 48 hours of drug intervention,the proportion of G2/M phase cells in the control group,DMDD group,Sorafenib group,and combination group were(10.63±0.32)%,(35.77±1.22)%,(30.03±2.22)%,and(38.97±0.60)%,respectively.Compared with the control group,the proportion of G2/M phase cells in the three groups significantly increased(P<0.0001).Compared with the Sorafenib group,the proportion of G2/M phase cells in the combination group significantly increased(P<0.0001).RT-qPCR and Western blot results showed that the combined application of DMDD and Sorafenib significantly inhibited the mRNA transcription level and protein expression level of PHGDH(P<0.05).Conclusion:The combined application of DMDD and Sorafenib has a synergistic effect that can enhance the inhibitory effect on the proliferation,invasion,and migration ability of Huh7 cells.The mechanism of this effect is related to the synergistic inhibition of the gene transcription and protein expression of PHGDH in the serine synthesis pathway.

Exploration of the Characteristics of Animal Supply and Demand in University Experimental Teaching Pratice

The supply and demand of laboratory animals for teaching in colleges and universities has its own internal characteristics.To grasp the supply and demand characteristics of laboratory animals for teaching is of vital importance to the planning,supply and use of teaching animals,the realization of teaching objectives and the completion of teaching tasks.Based on the supply of teaching experimental animals and the work of animal experimental teaching in our university in recent years,this paper expounds the inherent characteristics and practice of supply and demand of teaching experimental animals.

Evidence for a role of mitogen-activated protein kinases in the treatment of experimental acute pancreatitis

Acute pancreatitis(AP) is an inflammatory disease characterized by acute inflammation and necrosis of the pancreatic parenchyma. AP is often associated with organ failure, sepsis, and high mortality. The pathogenesis of AP is still not well understood. In recent years several papers have highlighted the cellular and molecular events of acute pancreatitis. Pancreatitis is initiated by activation of digestive enzymes within the acinar cells that are involved in autodigestion of the gland, followed by a massive infiltration of neutrophils and macrophages and release of inflammatory mediators, responsible for the local and systemic inflammatory response. The hallmark of AP is parenchymal cell necrosis that represents the cause of the high morbidity and mortality, so that new potential therapeutic approaches are indispensable for the treatment of patients at high risk of complications. However, not all factors that determine the onset and course of the disease have been explained. Aim of this article is to review the role of mitogen-activated protein kinases in pathogenesis of acute pancreatitis.

Experimental and petrological constraints on local-scale interaction of biotite-amphibole gneiss with H_2O-CO_2-(K,Na) Cl fluids at middle-crustal conditions:Example from the Limpopo Complex,South Africa

Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses （Central Zone of the Limpopo Complex） suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-（K, Na）Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-（K, Na）CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.

Comparison of Three Experimental Models for Rat Osteoarthritis Induction

Background: Osteoarthritis is a slowly progressive and debilitating disease with high prevalence in adult population. Knee is one of the joints most affected by this disorder. There are several models for animals’ osteoarthritis induction, however it is not identified any paper that compares these techniques. The present study was aimed to define the most appropriate model for rats osteoarthritis induction. Material and Methods: 40 Wistar rats were distributed into 4 groups of 10 animals each: normality group (NG);meniscectomy group (MG);quinolone group (QG) and iodoacetate group (IG). Radiographic images of the rat’s knees were analyzed as well as the amount of chondrocytes in the epiphyseal and articular cartilage. Results: In the radiographic analysis, there was a low correlation between the raters. Regarding the amount of chondrocytes in the epiphyseal cartilage, it was noticed that the IG and QG groups had fewer chondrocytes than NG, in contrast to MG that reported similar results to normality (p > 0.05). There was no significant difference between IG and QG groups (p > 0.05). Regarding the amount of chondrocytes in articular cartilage, it was noticed that the IG group showed fewer chondrocytes than NG (p 0.05). There was no significant difference between QG and MG groups (p > 0.05). Conclusion: Intraarticular injection of iodoacetate in rats is the model with greatest effect on reduction of chondrocytes amount.

Experimental Study on Treatment of SIV Infection by Zhongyan No. II In Monkeys

Objective: To investigate the curative effect of Zhongyan No. II (ZY II ) in treating SIVmac251 infection in macaques monkeys and evaluate the anti-viral effect of the drug as well as its protection on organism. Methods: Using SIVmac251 infected monkey model to detect the plasma SIVP 27 antigen level by viral isolation and ELISA; determine the T-lymphocyte subsets CD4 and CD8 by indirect immunofluorescence and flow cytometry, and investigate the serum content of neopterin and B2-mi-croglobulin B2-MG)by ELISA. The pathological examination was conducted as well. Results: ZY II

Observation on Effect of Gennlanchun (更年春) In Preventing Experimental Primary Osteoporosis

Objective: To evaluate the efficacy of Genni-anchun (GNC) in preventing primary osteoporosis. Methods: Fifty female SD rats of 10 - 12 months old were randomly divided into five groups. Except those in the sham operation group, animals were ovariectomized bilaterally. The gastric perfusion was started immediately after operation, with normal saline to the sham operation group and model group; GNC to high dose (2 ml) and low dos (1 ml) GNC groups and Nilestriol to the NE group, every day for 3 months. Animals were sacrificed at the end of experiment, their vertebra and

EXPERIMENTAL RESEARCH ON THE ANTI-CANCER IMMUNOMODULA-TIVE EFFECT OF THE POLYSOCOHARIBE-PEPTIDE OF CORIOLUS VERSICOLOR

Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to recover hemolysin HC50, to increase the weight of the thymus, and increase the alexin of serum C3 and the IgG content of tumor bearing mice. FSP also significantly raised the pha-gocytic activity of macrophages in normal mice. PSP had a significant inhibitory effect on P38S and S180 cells. At the concentration of 1 mg/ml, PSP inhibited the proliferating activity of some human tumor call lines, such as SGC 7901, SPC, SLY and Mei. It had a direct toxic effect on SPC cells. PSP significantly inhibited the synthesis of nucleic acids of Ehrlich ascites carcinoma cells. In addition, PSP was antagonistic to the side effects of chemotherapy and radiotherapy.

STUDY ON VIROLOGY OF EXPERIMENTAL LEUKEMIA IN CHINA

Since 1960, the Department of Pathophysio-logy of Shanghai Medical University has beenstudying the virology of experimental leukemia,the strains of L6565 mouse viral leukemia, SRSascitic and solid lymphoma and L783 transplan-table leukemia were established successively. Allof these tumor strains originated from the spon-taneous lymphocytic leukemia of Kunmin mouse(Figure 1). Type A and type C virus particlescould be observed in ultrathin sections of thymus,spleen and lymphonode of all these strains mouse

EXPERIMENTAL PRIMARY LIVER CANCER IN TREE SHREWS EXPOSED TO HUMAN HEPATITIS B VIRUS AND AFLATOXIN B_(1)

On the basis of the successful establishment of an animal model in tree shrews experimentally in fected with human hepatitis B virus (HHBV), a study on the hepatocarcinogenic effects of HHBV and aflatoxin B1 (AFB1) by using this animal model was conducted through a lifelong experiment. Among 41 tree shrews exposed to AFB1, 17 were experimentally infected by HHBV and 24 were uninfected. After 158 weeks, significant difference of primary liver cancer (PLC) incidence was present between the HHBV infected (52.94%) and uninfected (12.5%) groups (p<0.05). No difference was found between these two groups in the amount of AFB4 ingestion. Moreover, 1/9 of the tree shrews infected only by HHBV but not exposed to AFB4 developed PLC. No PLC was found in 6 tree shrews that had neither been infected with HHBV nor been exposed to AFB4. These results suggest the possible etiologic relationship between HHBV infection and PLC, as well as the synergetic effects of HHBV and AFB4 during PLC development.

DYNAMIC CHANGES OF ITO CELLS IN EXPERIMENTAL LIVER CIRRHOSIS OF RAT

That Ho cells in rat liver express desmin was confirmed by immunohistochemical technique. Consequently, changes of desmin-positive cells, lysozyme-positive cells and fibronectin were further studied in experimental cirrhosis of rat. It was found that desmln- positive cells, with the transitional feature between Ito cells and myofibroblasts or fibrobiasts under electron microscope, increased in number and expression of desmin in the necrotic areas as well as in the cellular fibrous septa, but decreased in number in the fibrous septa except those areas closed to the edges of the septa. These results suggested that Ito cells, myofibroblasts and fibroblasts might belong to the same cellular system and play an important role in the pathogenesis of cirrhosis. Meanwhile, it was also noted that changes of both fibronectin and lysozymepositive cells were correlated with those of desmin-positive cells. These provide evidence in vivo that flbronectin and Kupffer cells might exert certain effects on the migration and proliferation of Ito cells in liver cirrhosis.

Cancer stem cell hypothesis and gastric carcinogenesis: Experimental evidence and unsolved questions

Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continually diversifying cells. This heterogeneity enables the survival of different clones under particular conditions allowing growth at metastatic locations or resistance to chemotherapeutics. Cancer stem cell (CSC) theory completely overturns this traditional understanding of cancer suggesting that only CSCs can self-renew and promote tumor growth. CSCs are relatively refractory to conventional therapies, thus explaining why anti-cancer therapies are far from curative and why relapses of cancer are frequent. The identification of the CSC component of a tumor might, thus, open new therapeutic perspective based on the selective targeting of this small population of cells. In this review we examine the current scientific evidence supporting the existence of CSC in gastric tumors and analyze the main unsolved questions of this difficult field of cancer research.

Schistosoma mansoni proteins attenuate gastrointestinal motility disturbances during experimental colitis in mice

AIM:To investigate the therapeutic effect of Schistosoma mansoni(S.mansoni) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarectal injection of trinitrobenzene sulphate(TNBS) and 6 h later,mice were treated ip with S.mansoni proteins.Experiments were performed 5 d after TNBS injection.Inflammationwas quantified using validated inflammation parameters. Gastric emptying and geometric center were measured to assess in vivo gastrointestinal motility.Peristaltic activity of distal colonic segments was studied in vitro using a modified Trendelenburg set-up.Cytokine profiles of T-lymphocytes isolated from the colon were determined by real time reverse transcriptase-polymerase chain reaction. RESULTS:Intracolonic injection of TNBS caused severe colitis.Treatment with S.mansoni proteins significantly ameliorated colonic inflammation after 5 d.TNBS did not affect gastric emptying but significantly decreased the geometric center and impaired colonic peristaltic activity 5 d after the induction of colitis.Treatment with S.mansoni proteins ameliorated these in vivo and in vitro motility disturbances.In addition,TNBS injection caused a downregulation of effector T cell cytokines after 5 d,whereas a S.mansoni protein effect was no longer observed at this time point. CONCLUSION:Treatment with S.mansoni proteins attenuated intestinal inflammation and ameliorated motility disturbances during murine experimental colitis.

Favorable response to subcutaneous administration of infliximab in rats with experimental colitis

AIM: To investigate the influence of infliximab (Remicade)on experimental colitis produced by 2,4,6,trinitrobenzene sulfonic acid (TNBS) in rats.METHODS: Thirty-six Wistar rats were allocated into four groups (three groups of six animals each and a fourth of 12 animals). Six more healthy animals served as normal controls (Group 5). Group 1:colitis was induced by intracolonic installation of 25 mg of TNBS dissolved in 0.25 mL of 50% ethanol and infliximab was subcutaneously administered at a dose of 5 mg/kg BW; Group 2: colitis was induced and infliximab was subcutaneously administered at a dose of 10 mg/kg BW; Group 3: colitis was induced and infliximab was subcutaneously administered at a dose of 15 mg/kg BW; Group 4: colitis was induced without treatment with infliximab. Infliximab was administered on d 2-6. On the 7th d, all animals were killed. The colon was fixed in 10%buffered formalin and examined by light microscopy for the presence and activity of colitis and the extent of tissue damage. Tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were also measured.RESULTS: Significant differences concerning the presence of reparable lesions and the extent of bowel mucosa without active inflammation in all groups of animals treated with infliximab compared with controls were found. Significant reduction of the tissue levels of TNF-α in all groups of treated animals as compared withthe untreated ones was found (0.47±0.44, 1.09±0.86,0.43±0.31 vs 18.73±10.53 respectively). Significant reduction in the tissue levels of MDA was noticed in group 1 as compared to group 4, as well as between groups 2 and 4.CONCLUSION: Subcutaneous administration of infliximab reduces the inflammatory activity as well as tissue TNF-α and MDA levels in chemical colitis in rats.Infliximab at a dose of 5 mg/kg BW achieves better histological results and produces higher reduction of the levels of TNF-α than at a dose of 10 mg/kg BW.Infliximab at a dose of 5 mg/kg BW produces higher reduction of tissue MDA levels than at a dose of 15 mg/kg BW.

Histopathological comparison of topical therapy modalities for acute radiation proctitis in an experimental rat model

瞄准：与福尔马林相比评估为尖锐放射直肠炎的治疗可得到的流行热门治疗学的形式。方法：120 只老鼠的一个总数被使用。四个组(n = 30 ) 为每下列应用治疗形式与一个组一起被分析：控制， mesalazine，福尔马林， betamethasone，和 misoprostol。17.5 Gy 的单个部分被送到每只老鼠。在组老鼠被给 saline 的控制的老鼠，和在另外的三个组的老鼠在照耀以后开始第一天直到无痛苦的死亡的日子的一天收到了适当灌肠剂两次。在 d 上 5， 10，和 15，从每个组的十只老鼠是 euthanized，不知道处理赋值的一个病理学家用一个得分系统检验了直肠。结果：为表面上皮，腺(地窟) 和直肠的薄板 propria 基质的组织病理学说的分数在 d 上到达了他们的最大的水平 10。控制和福尔马林组有最高并且有的 mesalazine 最低，分别地在 d 上 10。在第 15 d 上， mesalazine， betamethasone，和 misoprostol 有 betamethasone 的最低分数。结论：Mesalazine， betamethasone，和 misoprostol 是最好的热门代理人因为放射直肠炎和福尔马林有煽动性的效果并且不应该被使用。