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Laboratory animals are essential mainly for experiments aiming to study pathogenesis and evaluate antivirals and vaccines against emerging human infectious diseases. Preclinical studies of coronavirus disease 19 (COVID-19) pathogenesis have used several animal species as models: transgenic human ACE2 mice (K18 mice), inbred BALB/c or C57BL/6N mice, ferrets, minks, domestic cats and dogs, hamsters, and macaques. However, the choice of an animal model relies on several limitations. Besides the host susceptibility, the researcher's experience with animal model management and the correct interpretation of clinical and laboratory records are crucial to succeed in preclinical translational research. Here, we summarise pathological and clinical findings correlated with virological data and immunological changes observed from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experimental infections using different well-established SARS-CoV-2 animal model species. This essay aims to critically evaluate the current state of animal model translation to clinical data, as described in the human SARS-CoV-2 infection.
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Plastination has revolutionized the study and research of anatomy, thanks to the biosecurity and indefinite preservation of human and animal bodies and organs. This paper presents the concept of Micro-Plastination, an ultra-thin sheet plastination technique, to obtain ultra-thin slices, of a thickness of less than 250 µm, for the identification and visualization of the microanatomy of any anatomical region in morphological and pathological experimental protocols.
La plastinación ha revolucionado el estudio y la investigación de la anatomía, gracias a la conservación biosegura y por tiempo indefinido de cadáveres y órganos humanos y animales. En este trabajo se presenta el concepto de Micro-Plastinación, técnica de plastinación de cortes ultrafinos para la obtención de cortes ultradelgados, de un grosor inferior a los 250 µm, para la identificación y visualización de la microanatomía de cualquier región anatómica en protocolos de morfología experimental.
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Humanos , Plastinación/métodos , Anatomía/métodos , Microtomía/métodosRESUMEN
Experimental pathology is an important part of life science research associated with animal experiment. Acquisition and fixation of optimum specimen and subsequent section of paraffin embedded tissue and dyeing are key factors playing important role in reliability, authenticity of pathological diagnosis.This paper summarizes the problems encountered in pathological section making of animal experiment and it correspond solutions.
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Objective To investigate the influence of fat-specific protein 27 (Fsp27) gene on the regulation of liver fibrogenesis in vivo.Methods Hepatic stellate cells (HSCs) were isolated from rat liver.Fsp27 gene was detected in primary HSCs and activated HSCs by real-time quantitative PCR (RTqPCR).Lentiviral vector carrying Fsp27 gene was constructed.The model of liver fibrosis was established by infusing carbon tetrachloride (CC14).The rats with liver fibrogenesis were infected by the virus.Liver sections were made to observe the structure and form of liver histocytes.The content of fibrous protein in liver and serum was detected by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay.Resukts HSCs were isolated and cultured successfully.The difference of Fsp27 gene between primary HSCs and activated HSCs was significant(P ＜ 0.01).The model of liver fibrosis was achieved.After infecting the model rats,we found the fibrosis level in treatment group was lower compared with control group.Conclusions Fsp27 treatment can decrease collagen deposition in the liver and inhibit the formation of fibrosis.
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ObjectiveTo investigate its dynamic characteristics and pathological mechanism on magnatic resonance diffusion weighted imaging (DWI) after chemoembolization in rabbit liver VX-2 tumor model.MethodsForty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity was opened.Forty VX-2 tumor models from them were divided into four groups.DWI was performed periodically and respectively for each group after chemoembolization.All VX-2 tumor samples of each group were studied by pathology.The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values.The statistical significance between different time groups,different area groups,or different b-value groups was calculated using SPSS 12.0 software.ResultsWhen b-value was 100 s/mm2,ADC values in the area of VX-2 tumor periphery,VX-2 tumor central,or normal liver parenchyma around tumor became gradually low in sixteen hours after chemoembolization,and were the lowest at sixteenth hour,and then they increased gradually from sixteenth hour to fourty-eighth hour after chemoembolization.The distinction of ADC between different time groups was significant,respectively ( F =7.325,P ＜ 0.01 ; F =2.496,P ＜ 0.05 ; F =6.856,P ＜0.01 ).Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor increased quickly in sixteen hours after chemoembolization; however,from sixteenth hour to forty-eighth hour,cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at first and then increased continually.Cellular necrosis in the area of VX-2 tumor periphery after chemoembolization was more significant than that before chemoembolization.The areas of dead cells in VX-2 tumors manifested low signal and high ADC value while the areas of viable cells manifested high signal and low ADC value.ConclusionsDWI is able to detect and discriminate tumor necrotic areas from viable cellular areas before and after chemoembolization.ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema,tissue cellular death,and microcirculation disturbance after chemoembolization.
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[Objective] To observe the effect of heated needle on the pathological changes of articular cartilage in mice with experimental knee osteoarthritis (OA). [ Methods ] Sixty-four NIH mice were randomly divided into 4 groups: heated needle group, electro-acupuncture (EA) group, model group and normal control group, 16 mice in each group. The mice models with knee OA were made with Xie's method, and then were treated for 2 weeks according to the experimental design. [Results] After treatment, the movable angle of right back knee in mice was increased in heated needle group and EA group ( P