Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various ...Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various lesions occurring in humans than the usual model of tumor implantations. The aim of the present study was to evaluate MRI liver examination in Sprague-Dawley(SD) rats as a routine method to detect hepatocellular carcinoma (HCC) nodules induced by DENA and to follow up their growth. METHODS:Hepatic carcinogenesis was induced in 80 male SD rats using oral DENA solution. All animals were imaged for liver tumor detection with a 1.5 Tesla magnet (Siemens Sonata,Erlangen, Germany) using correspondence scan parameters and a radio-frequency knee coil. Macroscopic examinations were performed along the axial MRI sections to evaluate magnetic resonance imaging (MRI) findings, and histopathological assessment was also performed. RESULTS:No false negative results were obtained on MR images. Hepatic tumors in 72 rats were confirmed macro-scopically and 68 rats were detected by MRI till the 20th week. The smallest and the largest nodules detected by MRI were 2 mm and 37 mm in diameter respectively. The agreement rate of MRI with macroscopic observation was 39. 1% and 97. 4% respectively for 2 mm to 5 mm and more than 5 mm nodules. CONCLUSIONS:The hepatic tumor induced by DENA provides a more representative range of tumors for imaging diagnosis and interventional treatment. MRI is the best approach for scrutinizing pathological changes of rat livers in the period of observation.展开更多
An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that m...An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.展开更多
BACKGROUND： Studies have demonstrated that selective innervation of the sacral nerve tract to the bladder plays an important role in bladder functional reconstruction following spinal cord injury. However, there are ...BACKGROUND： Studies have demonstrated that selective innervation of the sacral nerve tract to the bladder plays an important role in bladder functional reconstruction following spinal cord injury. However, there are very few studies reporting detailed morphological characteristics of urogenital center and lumbosacral nerve roots. OBJECTIVE： To analyze the spinal cord segment of the lumbosacral spinal cord urogenital center, and to observe morphological characteristics. DESIGN, TIME AND SETTING： A neuroanatomical study was performed at the Laboratory of Neuroanatomy, Peking University Health Science Center between September 2007 and March 2008. MATERIALS： Horseradish peroxidase-conjugated cholera toxin B subunit （CB-HRP） was purchased from Sigma, USA; surgical microscope was purchased from Zhenjian Zhongtian Optical Instrument, Jiangsu Province, China; BCL-420 biological and functional experimental system was purchased from Taimeng Science and Technology, Sichuan Province, China. METHODS： A total of 36 adult, Sprague Dawley rats were randomly assigned to groups A （n = 10）, B （n = 10）, C （n = 10）, and D （n = 6）. CB-HRP （3%, 10-15 μL） was injected into the bladder detrusor muscle （group A）, external urethral sphincter （group B）, and perineal muscles （group C）, respectively. Rats in group D were not given any treatments. MAIN OUTCOME MEASURES： At 72 hours after CB-HRP injection, CB-HRP-positive neurons were analyzed in lumbosacral segments using 3, 3＇, 5, 5＇-tetramethylbenzidine staining and an Olympus optic microscope, while anatomical structures in the respective spinal nerve tract were observed using a surgical microscope. RESULTS： CB-HRP-positive neurons were distributed in the L6-S1 segments of the spinal cord, and neurons primarily innervating the bladder detrusor muscle were located at the sacral parasympathetic nucleus and the intermediolateral nucleus. In addition, neurons that primarily innervate the external urethral sphincter and perineal muscles were observed in the ventrolateral portion （Onuf＇s nucleus）. The lumbar-sacral nerve roots were composed of varying nerve tracts, Le., they were typically divided into 1-2 sub-bundles, and the sub-bundles were then divided into 2-3 tiny bundles. There were extensive fibro-connections between the rootlets. CONCLUSION： The urogenital center in Sprague Dawley rats was located in the L6 -S1 segments of the spinal cord, and the rootlets were clearly observed. Therefore, this rat experimental model could be utilized for highly selective anterior/posterior rhizotomy.展开更多
This communication presents a new method of detecting the behaviour pattern in Sprague-Dawley (SD) rats based on the measurement of the dielectric properties of blood plasma at microwave frequencies at different perio...This communication presents a new method of detecting the behaviour pattern in Sprague-Dawley (SD) rats based on the measurement of the dielectric properties of blood plasma at microwave frequencies at different periods of time. The microwave measurements were performed by rectangular cavity perturbation method in the S-band of microwave frequency with the blood plasma collected from normal rats (Controls) as well as chemically induced rats (Aβ). A change is observed in the dielectric properties of the Aβsamples but not the controls samples at the extended period of time. This measurement technique is simple and the collection of blood from the rats is nonsurgical in nature. These results prove a new method of diagnosing Alzheimer’s Disease (AD) using microwave techniques.展开更多
Background: Lack of available reference values in a research setting under local conditions can be a drawback for beginners, as the accuracy of data from control samples cannot be checked at the beginning of a researc...Background: Lack of available reference values in a research setting under local conditions can be a drawback for beginners, as the accuracy of data from control samples cannot be checked at the beginning of a research project. This affects comparisons with data from test samples. To avoid these complications in their research projects,beginners tend to have a greater number of animals in the control group compared to test groups in order to have control group measurements within 2 SDs of the mean.Methods: As non-availability of reference values was a long-felt need, the described project was conducted in order to establish a reference database for selected haematological, biochemical and physiological parameters using apparently healthy Sprague-Dawley rats bred in the Animal House of Faculty of Medicine, University of Colombo(UCFM).Results: Differences in mean values of packed cell volume(PCV), mean corpuscular volume(MCV) and mean corpuscular hemoglobin concentration(MCHC), serum creatinine and blood glucose levels between the two genders were statistically significant. Lipid profile measurements did not differ significantly between genders, but mean and median values of triglycerides(TG) between male and female rats showed a difference of more than 10 mg/dL. The liver enzymes alkaline phosphatase(AP)and aspartate aminotransferase(AST) were also statistically significantly different between sexes. Despite wide variation in mean alanine aminotransferase(ALT)between sexes, the difference was not statistically significant.Conclusion: The findings of this project should support to a certain extent the"Reduction" aspect of the 3 Rs concept of Russell and Burch by reducing the number of Sprague-Dawley rats used in future research projects at UCFM.展开更多
基金This study was supported by grants from specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (20030b10090)China Medical Board of New York (CMB 82-412) the TCM Administration Bureau of Sichuan Province (TCM 2004 B03).
文摘Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various lesions occurring in humans than the usual model of tumor implantations. The aim of the present study was to evaluate MRI liver examination in Sprague-Dawley(SD) rats as a routine method to detect hepatocellular carcinoma (HCC) nodules induced by DENA and to follow up their growth. METHODS:Hepatic carcinogenesis was induced in 80 male SD rats using oral DENA solution. All animals were imaged for liver tumor detection with a 1.5 Tesla magnet (Siemens Sonata,Erlangen, Germany) using correspondence scan parameters and a radio-frequency knee coil. Macroscopic examinations were performed along the axial MRI sections to evaluate magnetic resonance imaging (MRI) findings, and histopathological assessment was also performed. RESULTS:No false negative results were obtained on MR images. Hepatic tumors in 72 rats were confirmed macro-scopically and 68 rats were detected by MRI till the 20th week. The smallest and the largest nodules detected by MRI were 2 mm and 37 mm in diameter respectively. The agreement rate of MRI with macroscopic observation was 39. 1% and 97. 4% respectively for 2 mm to 5 mm and more than 5 mm nodules. CONCLUSIONS:The hepatic tumor induced by DENA provides a more representative range of tumors for imaging diagnosis and interventional treatment. MRI is the best approach for scrutinizing pathological changes of rat livers in the period of observation.
基金supported by the National Natural Science Foundation of China,No.81201546(to YXL)the Doctoral Start-up Program of Natural Science Foundation of Guangdong Province of China,No.2017A030310302(to ZWZ)+1 种基金the Medical Scientific Research Foundation of Guangdong Province of China,No.A2016018(to BH)the Science and Technology Project of Guangdong Province of China,No.2016A010103012(to JHL)
文摘An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.
基金Supported by: the National Natural Science Foundation of China, No. 30672096
文摘BACKGROUND： Studies have demonstrated that selective innervation of the sacral nerve tract to the bladder plays an important role in bladder functional reconstruction following spinal cord injury. However, there are very few studies reporting detailed morphological characteristics of urogenital center and lumbosacral nerve roots. OBJECTIVE： To analyze the spinal cord segment of the lumbosacral spinal cord urogenital center, and to observe morphological characteristics. DESIGN, TIME AND SETTING： A neuroanatomical study was performed at the Laboratory of Neuroanatomy, Peking University Health Science Center between September 2007 and March 2008. MATERIALS： Horseradish peroxidase-conjugated cholera toxin B subunit （CB-HRP） was purchased from Sigma, USA; surgical microscope was purchased from Zhenjian Zhongtian Optical Instrument, Jiangsu Province, China; BCL-420 biological and functional experimental system was purchased from Taimeng Science and Technology, Sichuan Province, China. METHODS： A total of 36 adult, Sprague Dawley rats were randomly assigned to groups A （n = 10）, B （n = 10）, C （n = 10）, and D （n = 6）. CB-HRP （3%, 10-15 μL） was injected into the bladder detrusor muscle （group A）, external urethral sphincter （group B）, and perineal muscles （group C）, respectively. Rats in group D were not given any treatments. MAIN OUTCOME MEASURES： At 72 hours after CB-HRP injection, CB-HRP-positive neurons were analyzed in lumbosacral segments using 3, 3＇, 5, 5＇-tetramethylbenzidine staining and an Olympus optic microscope, while anatomical structures in the respective spinal nerve tract were observed using a surgical microscope. RESULTS： CB-HRP-positive neurons were distributed in the L6-S1 segments of the spinal cord, and neurons primarily innervating the bladder detrusor muscle were located at the sacral parasympathetic nucleus and the intermediolateral nucleus. In addition, neurons that primarily innervate the external urethral sphincter and perineal muscles were observed in the ventrolateral portion （Onuf＇s nucleus）. The lumbar-sacral nerve roots were composed of varying nerve tracts, Le., they were typically divided into 1-2 sub-bundles, and the sub-bundles were then divided into 2-3 tiny bundles. There were extensive fibro-connections between the rootlets. CONCLUSION： The urogenital center in Sprague Dawley rats was located in the L6 -S1 segments of the spinal cord, and the rootlets were clearly observed. Therefore, this rat experimental model could be utilized for highly selective anterior/posterior rhizotomy.
文摘This communication presents a new method of detecting the behaviour pattern in Sprague-Dawley (SD) rats based on the measurement of the dielectric properties of blood plasma at microwave frequencies at different periods of time. The microwave measurements were performed by rectangular cavity perturbation method in the S-band of microwave frequency with the blood plasma collected from normal rats (Controls) as well as chemically induced rats (Aβ). A change is observed in the dielectric properties of the Aβsamples but not the controls samples at the extended period of time. This measurement technique is simple and the collection of blood from the rats is nonsurgical in nature. These results prove a new method of diagnosing Alzheimer’s Disease (AD) using microwave techniques.
文摘Background: Lack of available reference values in a research setting under local conditions can be a drawback for beginners, as the accuracy of data from control samples cannot be checked at the beginning of a research project. This affects comparisons with data from test samples. To avoid these complications in their research projects,beginners tend to have a greater number of animals in the control group compared to test groups in order to have control group measurements within 2 SDs of the mean.Methods: As non-availability of reference values was a long-felt need, the described project was conducted in order to establish a reference database for selected haematological, biochemical and physiological parameters using apparently healthy Sprague-Dawley rats bred in the Animal House of Faculty of Medicine, University of Colombo(UCFM).Results: Differences in mean values of packed cell volume(PCV), mean corpuscular volume(MCV) and mean corpuscular hemoglobin concentration(MCHC), serum creatinine and blood glucose levels between the two genders were statistically significant. Lipid profile measurements did not differ significantly between genders, but mean and median values of triglycerides(TG) between male and female rats showed a difference of more than 10 mg/dL. The liver enzymes alkaline phosphatase(AP)and aspartate aminotransferase(AST) were also statistically significantly different between sexes. Despite wide variation in mean alanine aminotransferase(ALT)between sexes, the difference was not statistically significant.Conclusion: The findings of this project should support to a certain extent the"Reduction" aspect of the 3 Rs concept of Russell and Burch by reducing the number of Sprague-Dawley rats used in future research projects at UCFM.
