Background:The Mongolian gerbil is an excellent laboratory animal for preparing the cerebral ischemia model due to its inherent deficiency in the circle of Willis.However,the low incidence and unpredictability of symp...Background:The Mongolian gerbil is an excellent laboratory animal for preparing the cerebral ischemia model due to its inherent deficiency in the circle of Willis.However,the low incidence and unpredictability of symptoms are caused by numerous complex variant types of the circle.Additionally,the lack of an evaluation system for the cer-ebral ischemia/reperfusion(I/R)model of gerbils has shackled the application of this model.Methods:We created a symptom-oriented principle and detailed neurobehavioral scoring criteria.At different time points of reperfusion,we analyzed the alteration in locomotion by rotarod test and grip force score,infarct volume by triphenyltetrazo-lium chloride(TTC)staining,neuron loss using Nissl staining,and histological charac-teristics using hematoxylin-eosin(H&E)straining.Results:With a successful model rate of 56%,32 of the 57 gerbils operated by our method harbored typical features of cerebral I/R injury,and the mortality rate in the male gerbils was significantly higher than that in the female gerbils.The suc-cessfully prepared I/R gerbils demonstrated a significant reduction in motility and grip strength at 1 day after reperfusion;formed obvious infarction;exhibited typi-cal pathological features,such as tissue edema,neuronal atrophy and death,and vacuolated structures;and were partially recovered with the extension of reperfu-sion time.Conclusion:This study developed a new method for the unilateral common carotid artery ligation I/R model of gerbil and established a standardized evaluation system for this model,which could provide a new cerebral I/R model of gerbils with more practical applications.展开更多
AIM: To investigate the effectiveness of 4 d' anti-Helicobacter pylori therapy on the H pylori-infected Mongolian gerbils based on physiological and pathological changes. METHODS: We used 6-wk-old male gerbils ora...AIM: To investigate the effectiveness of 4 d' anti-Helicobacter pylori therapy on the H pylori-infected Mongolian gerbils based on physiological and pathological changes. METHODS: We used 6-wk-old male gerbils orally inoculated with H pylori (ATCC43504, 2×108 CFU/mL). Seven weeks after H pylori inoculation, the animals of study group received 4 d' anti-H pylori triple therapy (H pylori-eradicated group). Seven days later, all animals of the H pylori-eradicated and control groups (H pylori-infected & H pylori-uninfected groups) were sacrificed. We examined gastric mucosal lesions macroscopically, studied gastritis microscopically and determined the stomach weight ratio, myeloperoxidase (MPO) activity and prostaglandin (PG) E2 level. RESULTS: The results showed that both macroscopic and histological gastric damages were significantly less in H pylori-eradicated group than H pylori-infected group. Stomach weight ratio, MPO activity and PGE2 levels were significantly higher in H pylori-infected group than those in the other two groups. CONCLUSION: Four days' anti-H pylori therapy was effective in the improvement of H pylori-induced gastric lesions in Mongolian gerbils.展开更多
AIM： To investigate whether chronic H pylori infection has the potential to induce pancreatitis in the Mongolian gerbil model, and whether it is dependent on an intact type Ⅳ secretion system. METHODS： Mongolian ge...AIM： To investigate whether chronic H pylori infection has the potential to induce pancreatitis in the Mongolian gerbil model, and whether it is dependent on an intact type Ⅳ secretion system. METHODS： Mongolian gerbils were infected with wild type （WT） H pylori type Ⅰ strain B128 or its isogenic mutant B128 △cag γ （defective type Ⅳ secretion）. After seven months of infection, H pylori was reisolated from antrum and corpus and Hpylori DNA was analyzed by seminested polymerase chain reaction （PCR）. Inflammation and histological changes were documented in the gastric antrum, corpus, and pancreas by immunohistochemistry. Cytokine mRNA, gastric pH, plasma gastrin, amylase, lipase, and glucose levels were determined. RESULTS： The H pylori infection rate was 95%. Eight infected animals, but none of the uninfected group, developed transmural inflammation and chronic pancreatitis. Extensive interstitial fibrosis and inflammation of the pancreatic lobe adjacent to the antrum was confirmed by trichrome stain, and immuno-histochemically. Pro-inflammatory cytokine mRNA was significantly increased in the antral mucosa of all infected gerbils. In the corpus, only cytokine levels of WT-infected animals andthose developing transmural inflammation and pancreatitis were significantly increased. Levels of lipase, but not glucose or amylase levels, were significantly reduced in the pancreatitis group. H pylori DNA was detected in infected antral and corpus tissue,but not in the pancreas CONCLUSION： H pylori infection is able to induce chronic pancreatitis in Mongolian gerbils independently of the type Ⅳ secretion system, probably by an indirect mechanism associated with a penetrating ulcer.展开更多
AIM: The cag pathogenicity island (PAI) is one of potential virulence determinants of Helicobacter pylori. The Mongolian gerbil is a suitable experimental animal for the screening of virulence factors of H pylori.METH...AIM: The cag pathogenicity island (PAI) is one of potential virulence determinants of Helicobacter pylori. The Mongolian gerbil is a suitable experimental animal for the screening of virulence factors of H pylori.METHODS: Five-week-old Mongolian gerbils were inoculated with a standard H pylori strain (ATCC 43504)possessing the cag PAI or a clinical isolate lacking the genes' cluster (OHPC-0002). The animals were killed at 2, 4, 8, 24 and 48 wk after inoculation (n = 5 each), and macroscopic and histopathological findings in the stomachs were compared.RESULTS: In gerbils infected with ATCC 43504, a more severe degree of infiltration of polynuclear and mononuclear cells and lymphoid follicles was observed from 4 wk after inoculation compared to gerbils infected with OHPC-0002 especially in the antrum and transitional zone from the fundic to pyloric gland area. In addition,glandular atrophy, intestinal metaplasia, gastric ulcer and hyperplastic polyps were noted in gerbils infected with ATCC 43504, whereas only mild gastric erosions occurred in those infected with OHPC-0002.CONCLUSION: Our results indicate that the cag PAI could be directly involved in gastric immune and inflammatory responses in the Mongolian gerbils, leading to a more advanced gastric disease.展开更多
Objective： To setup an animal model of gastric carcinogenesis by Helicobacter pylori （Hp） for basic, prevention and therapeutic research of Hp-related diseases. Methods： 22 young male Mongolian gerbils were admini...Objective： To setup an animal model of gastric carcinogenesis by Helicobacter pylori （Hp） for basic, prevention and therapeutic research of Hp-related diseases. Methods： 22 young male Mongolian gerbils were administrated with suspension of Hp strain TN2 by intragastric garage for 5 consecutive times （4×10^8 CFU/time, 1 time/4 days）. 10 male gerbils were used as negative control. Two infected gerbils were killed at 10, 20, and 30 weeks, respectively, after inoculation to monitor the development of gastric lesions. Other animals were killed at 40 experimental weeks. Pathological changes of glandular stomach were examined histologically. Results： Gastric intraepithelial neoplasias （GIN） and low-grade dysplasias were observed only in the pyloric antrum of Hp-treated gerbils （3 and 2 ones, respectively）, but not in control group （5/13 vs. 0/10, P〈0.04）. High incidence of chronic active gastritis and chronic atrophic gastritis were observed in Hp-treated animals （10/13, 76.9%）. Low incidence of chronic atrophic gastritis was also detected in negative control gerbils （3/10, 30%; P〈0.04）. Conclusion： Hp inoculation could induce chronic inflammation and malignant lesions of the glandular stomach of Mongolian gerbils conveniently.展开更多
Background:The nest flea index of Meriones unguiculatus is a critical indicator for the prevention and control of plague,which can be used not only to detect the spatial and temporal distributions of Meriones unguicul...Background:The nest flea index of Meriones unguiculatus is a critical indicator for the prevention and control of plague,which can be used not only to detect the spatial and temporal distributions of Meriones unguiculatus,but also to reveal its cluster rule.This research detected the temporal and spatial distribution characteristics of the plague natural foci of Mongolian gerbils by body flea index from 2005 to 2014,in order to predict plague outbreaks.Methods:Global spatial autocorrelation was used to describe the entire spatial distribution pattern of the body flea index in the natural plague foci of typical Chinese Mongolian gerbils.Cluster and outlier analysis and hot spot analysis were also used to detect the intensity of clusters based on geographic information system methods.The quantity of M.unguiculatus nest fleas in the sentinel surveillance sites from 2005 to 2014 and host density data of the study area from 2005 to 2010 used in this study were provided by Chinese Center for Disease Control and Prevention.Results:The epidemic focus regions of the Mongolian gerbils remain the same as the hot spot regions relating to the body flea index.High clustering areas possess a similar pattern as the distribution pattern of the body flea index indicating that the transmission risk of plague is relatively high.In terms of time series,the area of the epidemic focus gradually increased from 2005 to 2007,declined rapidly in 2008 and 2009,and then decreased slowly and began trending towards stability from 2009 to 2014.For the spatial change,the epidemic focus regions began moving northward from the southwest epidemic focus of the Mongolian gerbils from 2005 to 2007,and then moved from north to south in 2007 and 2008.Conclusions:The body flea index of Chinese gerbil foci reveals significant spatial and temporal aggregation characteristics through the employing of spatial autocorrelation.The diversity of temporary and spatial distribution is mainly affected by seasonal variation,the human activity and natural factors.展开更多
Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is sup...Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is suppressed in overweight Mongolian gerbils(Meriones unguiculatus).In the study,16 overweight(body mass:90.8-127.6 g)and 16 lean gerbils(body mass:60.5-77.7 g)were randomly selected from a total of 174 male gerbils(body mass range:55.8-144.7 g).Half of the overweight and lean males were injected with sterile saline;the others were immunochallenged(IC)with phytohaemagglutinin and keyhole limpet hemocyanin to assess cellular and humoral immunity,respectively.Body fat mass,wet and dry spleen mass,leukocyte counts,blood glucose levels and serum leptin levels were significantly higher in the overweight gerbils than in the lean gerbils.However,phytohemagglutinin response indicative of cellular immunity and immunoglobulin G concentrations was significantly lower in the IC overweight gerbils than in the IC lean gerbils.These results indicate that cellular and humoral immunity are impaired in the overweight gerbils.Excessive body fat mass,higher leukocyte counts and serum leptin levels imply that overweight gerbils are in a low grade inflammatory state.展开更多
AIM： To evaluate the optimal intervention point of a selective cyclooxygenase-2 （COX-2） inhibitor, Celecoxib, for inhibiting Helicobacter pylori （H pylori-associated gastric carcinogenesis in Mongolian gerbils （...AIM： To evaluate the optimal intervention point of a selective cyclooxygenase-2 （COX-2） inhibitor, Celecoxib, for inhibiting Helicobacter pylori （H pylori-associated gastric carcinogenesis in Mongolian gerbils （MGs）.METHODS： One hundred and twelve MGs were divided into six groups （A-F）. One hundred gerbils were inoculated with H pylor/（groups A-E）. Twelve gerbils were inoculated with vehicle broth only （group F）. After 4 wk, they were given N＇-methyl-N＇ -nitro-N-nitroso-guanidine （MNNG） （50 μg/mL） in the drinking water for 20 wk. in groups B-E, the animals were given the stock Celecoxib （10 mg/kg per day） diet from the 21st, 31st, 21st and 41st week respectively. The periods of administering Celecoxib were 30, 20, 20, and 15 wk respectively. On the 51st week, the animals were sacrificed for histological examination. Local PCNA expression was examined by the immunohistochemistry method. The expression of COX-2 protein was assessed by Western Blot. Analysis used the 2 test. The difference was regarded as significant when P value was less than 0.05. RESULTS： Seventeen percent （17/100） of H pyloriinfected MGs developed gastric cancer. All of these lesions were well-differentiated adenocarcinoma. The incidence rates of adenocarcinoma in groups A-F were 40%, 0%, 0%, 20%, 25%, and 0% respectively. The inflammatory scores were higher in group B than in other groups. There was no inflammatory response noted in group F. Celecoxib treatment resulted in a significant reduction in the proliferation of H pyloriinfected mucosal cells （groups B, C and D） （P 〈 0.01）. The expression of COX-2 protein was significantly attenuated in the groups which were Celecoxib-treated for more than 20 wk （groups B, C, D）. The groups treated with Celecoxib had a significantly lower rate of advanced gastric cancer （34% vs 75%, P 〈 0.001） There were no sudden deaths in any of the groups. CONCLUSION： Short-term treatment with Celecoxib has an anti-carcinogenic effect, and resulted in less severe inflammation and inhibited the invasive degree of gastric cancer.展开更多
Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by mis...Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.展开更多
Although various animal models have been developed to clarify gastric carcinogenesis, apparent mechanism of gastric cancer was not clarified in recent years. Since the recognition of the pathogenicity of Helocobacter ...Although various animal models have been developed to clarify gastric carcinogenesis, apparent mechanism of gastric cancer was not clarified in recent years. Since the recognition of the pathogenicity of Helocobacter pylori（H pylori）, several animal models with H pylori infection have been developed to confirm the association between Hpylori and gastric cancer. Nonhuman primate and rodent models were suitable for this study. Japanese monkey model revealed atrophic gastritis and p53 mutation after long-term infection of Hpylori. Mongolian gerbil model showed the development of gastric carcinoma with H pylori infection alone, as well as with combination of chemical carcinogens, such as N-methyl- N-nitrosourea and N-methyl-N-nitro-N＇-nitrosoguanidine. The histopathological changes of these animal models after H pylori inoculation are closely similar to those in human beings with Hpylori infection. Eradication therapy attenuated the development of gastric cancer in Hpylori- infected Mongolian gerbil. Although several features of animal models differ from those seen in human beings, these experimental models provide a starting point for further studies to clarify the mechanism of gastric carcinogenesis as a result of Hpylon infection and assist the planning of eradication therapy to prevent gastric carcinoma.展开更多
Ambient temperature considerably affects the physiology and behavior of mammals.Thermosensory and thermoregulatory abilities play an important role in the response to changing ambient temperature in endotherms.However...Ambient temperature considerably affects the physiology and behavior of mammals.Thermosensory and thermoregulatory abilities play an important role in the response to changing ambient temperature in endotherms.However,the molecular mechanisms of behavioral thermoregulation remain poorly understood.Transient receptor potential vanilloid-1(TRPV1)is activated by changes in ambient temperature and is involved in acute thermoregulation.Here,we aimed to determine whether TRPV1 is involved in behavioral thermoregulation in wild rodents by conducting 2 experiments.In the first,42 adult Mongolian gerbils(Meriones unguiculatus;14 per treatment)were randomly assigned to 3 housing temperatures(4,23,and 36℃for 4 weeks.In the second,20 gerbils(10 per treatment)were randomly injected with capsaicin(TRPV1 agonist)or AMG517(TRPV1 antagonist).The results showed a significant decrease in food intake and non-shivering thermogenesis in the gerbils housed at 36℃.Additionally,there was a significant increase in the preference of gerbils housed at 4℃ to low temperatures.The expression of TRPV1 protein in the brown adipose tissue(BAT)and liver was significantly positively correlated with that of protein kinase A(PKA).The expression of TRPV1 and PKA proteins in the BAT was positively correlated with the temperature preference of the gerbils.The gerbils injected with capsaicin preferred significantly lower temperatures than the control group gerbils.These findings suggest that TRPV1 and PKA are involved in behavioral thermoregulation in Mongolian gerbils.展开更多
Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands o...Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.展开更多
The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial...The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2021YFF0702402National Natural Science Foundation of China,Grant/Award Number:32070531。
文摘Background:The Mongolian gerbil is an excellent laboratory animal for preparing the cerebral ischemia model due to its inherent deficiency in the circle of Willis.However,the low incidence and unpredictability of symptoms are caused by numerous complex variant types of the circle.Additionally,the lack of an evaluation system for the cer-ebral ischemia/reperfusion(I/R)model of gerbils has shackled the application of this model.Methods:We created a symptom-oriented principle and detailed neurobehavioral scoring criteria.At different time points of reperfusion,we analyzed the alteration in locomotion by rotarod test and grip force score,infarct volume by triphenyltetrazo-lium chloride(TTC)staining,neuron loss using Nissl staining,and histological charac-teristics using hematoxylin-eosin(H&E)straining.Results:With a successful model rate of 56%,32 of the 57 gerbils operated by our method harbored typical features of cerebral I/R injury,and the mortality rate in the male gerbils was significantly higher than that in the female gerbils.The suc-cessfully prepared I/R gerbils demonstrated a significant reduction in motility and grip strength at 1 day after reperfusion;formed obvious infarction;exhibited typi-cal pathological features,such as tissue edema,neuronal atrophy and death,and vacuolated structures;and were partially recovered with the extension of reperfu-sion time.Conclusion:This study developed a new method for the unilateral common carotid artery ligation I/R model of gerbil and established a standardized evaluation system for this model,which could provide a new cerebral I/R model of gerbils with more practical applications.
文摘AIM: To investigate the effectiveness of 4 d' anti-Helicobacter pylori therapy on the H pylori-infected Mongolian gerbils based on physiological and pathological changes. METHODS: We used 6-wk-old male gerbils orally inoculated with H pylori (ATCC43504, 2×108 CFU/mL). Seven weeks after H pylori inoculation, the animals of study group received 4 d' anti-H pylori triple therapy (H pylori-eradicated group). Seven days later, all animals of the H pylori-eradicated and control groups (H pylori-infected & H pylori-uninfected groups) were sacrificed. We examined gastric mucosal lesions macroscopically, studied gastritis microscopically and determined the stomach weight ratio, myeloperoxidase (MPO) activity and prostaglandin (PG) E2 level. RESULTS: The results showed that both macroscopic and histological gastric damages were significantly less in H pylori-eradicated group than H pylori-infected group. Stomach weight ratio, MPO activity and PGE2 levels were significantly higher in H pylori-infected group than those in the other two groups. CONCLUSION: Four days' anti-H pylori therapy was effective in the improvement of H pylori-induced gastric lesions in Mongolian gerbils.
基金Supported by grants from the Deutsche Forschungsgemeinschaft (SFB576) to RH and (RI 972/3-1) to GRthe Federal Ministry of Education and Research (BMBF) (NGFN-2) to RHby US Public Health Service Grants P01 DK062041 and R01DK45729 to JLM
文摘AIM： To investigate whether chronic H pylori infection has the potential to induce pancreatitis in the Mongolian gerbil model, and whether it is dependent on an intact type Ⅳ secretion system. METHODS： Mongolian gerbils were infected with wild type （WT） H pylori type Ⅰ strain B128 or its isogenic mutant B128 △cag γ （defective type Ⅳ secretion）. After seven months of infection, H pylori was reisolated from antrum and corpus and Hpylori DNA was analyzed by seminested polymerase chain reaction （PCR）. Inflammation and histological changes were documented in the gastric antrum, corpus, and pancreas by immunohistochemistry. Cytokine mRNA, gastric pH, plasma gastrin, amylase, lipase, and glucose levels were determined. RESULTS： The H pylori infection rate was 95%. Eight infected animals, but none of the uninfected group, developed transmural inflammation and chronic pancreatitis. Extensive interstitial fibrosis and inflammation of the pancreatic lobe adjacent to the antrum was confirmed by trichrome stain, and immuno-histochemically. Pro-inflammatory cytokine mRNA was significantly increased in the antral mucosa of all infected gerbils. In the corpus, only cytokine levels of WT-infected animals andthose developing transmural inflammation and pancreatitis were significantly increased. Levels of lipase, but not glucose or amylase levels, were significantly reduced in the pancreatitis group. H pylori DNA was detected in infected antral and corpus tissue,but not in the pancreas CONCLUSION： H pylori infection is able to induce chronic pancreatitis in Mongolian gerbils independently of the type Ⅳ secretion system, probably by an indirect mechanism associated with a penetrating ulcer.
文摘AIM: The cag pathogenicity island (PAI) is one of potential virulence determinants of Helicobacter pylori. The Mongolian gerbil is a suitable experimental animal for the screening of virulence factors of H pylori.METHODS: Five-week-old Mongolian gerbils were inoculated with a standard H pylori strain (ATCC 43504)possessing the cag PAI or a clinical isolate lacking the genes' cluster (OHPC-0002). The animals were killed at 2, 4, 8, 24 and 48 wk after inoculation (n = 5 each), and macroscopic and histopathological findings in the stomachs were compared.RESULTS: In gerbils infected with ATCC 43504, a more severe degree of infiltration of polynuclear and mononuclear cells and lymphoid follicles was observed from 4 wk after inoculation compared to gerbils infected with OHPC-0002 especially in the antrum and transitional zone from the fundic to pyloric gland area. In addition,glandular atrophy, intestinal metaplasia, gastric ulcer and hyperplastic polyps were noted in gerbils infected with ATCC 43504, whereas only mild gastric erosions occurred in those infected with OHPC-0002.CONCLUSION: Our results indicate that the cag PAI could be directly involved in gastric immune and inflammatory responses in the Mongolian gerbils, leading to a more advanced gastric disease.
文摘Objective： To setup an animal model of gastric carcinogenesis by Helicobacter pylori （Hp） for basic, prevention and therapeutic research of Hp-related diseases. Methods： 22 young male Mongolian gerbils were administrated with suspension of Hp strain TN2 by intragastric garage for 5 consecutive times （4×10^8 CFU/time, 1 time/4 days）. 10 male gerbils were used as negative control. Two infected gerbils were killed at 10, 20, and 30 weeks, respectively, after inoculation to monitor the development of gastric lesions. Other animals were killed at 40 experimental weeks. Pathological changes of glandular stomach were examined histologically. Results： Gastric intraepithelial neoplasias （GIN） and low-grade dysplasias were observed only in the pyloric antrum of Hp-treated gerbils （3 and 2 ones, respectively）, but not in control group （5/13 vs. 0/10, P〈0.04）. High incidence of chronic active gastritis and chronic atrophic gastritis were observed in Hp-treated animals （10/13, 76.9%）. Low incidence of chronic atrophic gastritis was also detected in negative control gerbils （3/10, 30%; P〈0.04）. Conclusion： Hp inoculation could induce chronic inflammation and malignant lesions of the glandular stomach of Mongolian gerbils conveniently.
基金The research was supported by the Innovation Project of State Key Laboratory of Resources and Environment Information System(Grant No.088RA90BYA)the Ministry of Science and Technology of China(Grant No.2016YFC1201301).
文摘Background:The nest flea index of Meriones unguiculatus is a critical indicator for the prevention and control of plague,which can be used not only to detect the spatial and temporal distributions of Meriones unguiculatus,but also to reveal its cluster rule.This research detected the temporal and spatial distribution characteristics of the plague natural foci of Mongolian gerbils by body flea index from 2005 to 2014,in order to predict plague outbreaks.Methods:Global spatial autocorrelation was used to describe the entire spatial distribution pattern of the body flea index in the natural plague foci of typical Chinese Mongolian gerbils.Cluster and outlier analysis and hot spot analysis were also used to detect the intensity of clusters based on geographic information system methods.The quantity of M.unguiculatus nest fleas in the sentinel surveillance sites from 2005 to 2014 and host density data of the study area from 2005 to 2010 used in this study were provided by Chinese Center for Disease Control and Prevention.Results:The epidemic focus regions of the Mongolian gerbils remain the same as the hot spot regions relating to the body flea index.High clustering areas possess a similar pattern as the distribution pattern of the body flea index indicating that the transmission risk of plague is relatively high.In terms of time series,the area of the epidemic focus gradually increased from 2005 to 2007,declined rapidly in 2008 and 2009,and then decreased slowly and began trending towards stability from 2009 to 2014.For the spatial change,the epidemic focus regions began moving northward from the southwest epidemic focus of the Mongolian gerbils from 2005 to 2007,and then moved from north to south in 2007 and 2008.Conclusions:The body flea index of Chinese gerbil foci reveals significant spatial and temporal aggregation characteristics through the employing of spatial autocorrelation.The diversity of temporary and spatial distribution is mainly affected by seasonal variation,the human activity and natural factors.
基金This study was supported by grants to DHW from the National Science and Technology Ministry Project(No.2007BC109103)the National Natural Science Foundation of China(30625009).
文摘Animal immunity is usually impaired in obesity.We know little about the effect of being overweight or obese on the immune function of wild rodents.The present study is aimed to test the hypothesis that immunity is suppressed in overweight Mongolian gerbils(Meriones unguiculatus).In the study,16 overweight(body mass:90.8-127.6 g)and 16 lean gerbils(body mass:60.5-77.7 g)were randomly selected from a total of 174 male gerbils(body mass range:55.8-144.7 g).Half of the overweight and lean males were injected with sterile saline;the others were immunochallenged(IC)with phytohaemagglutinin and keyhole limpet hemocyanin to assess cellular and humoral immunity,respectively.Body fat mass,wet and dry spleen mass,leukocyte counts,blood glucose levels and serum leptin levels were significantly higher in the overweight gerbils than in the lean gerbils.However,phytohemagglutinin response indicative of cellular immunity and immunoglobulin G concentrations was significantly lower in the IC overweight gerbils than in the IC lean gerbils.These results indicate that cellular and humoral immunity are impaired in the overweight gerbils.Excessive body fat mass,higher leukocyte counts and serum leptin levels imply that overweight gerbils are in a low grade inflammatory state.
基金Supported by A grant from Kaohsiung Medical University (Q096014)Kaohsiung Municipal Hsiao-Kang Hospital (kmhk-96-005, kmhk-95-005)
文摘AIM： To evaluate the optimal intervention point of a selective cyclooxygenase-2 （COX-2） inhibitor, Celecoxib, for inhibiting Helicobacter pylori （H pylori-associated gastric carcinogenesis in Mongolian gerbils （MGs）.METHODS： One hundred and twelve MGs were divided into six groups （A-F）. One hundred gerbils were inoculated with H pylor/（groups A-E）. Twelve gerbils were inoculated with vehicle broth only （group F）. After 4 wk, they were given N＇-methyl-N＇ -nitro-N-nitroso-guanidine （MNNG） （50 μg/mL） in the drinking water for 20 wk. in groups B-E, the animals were given the stock Celecoxib （10 mg/kg per day） diet from the 21st, 31st, 21st and 41st week respectively. The periods of administering Celecoxib were 30, 20, 20, and 15 wk respectively. On the 51st week, the animals were sacrificed for histological examination. Local PCNA expression was examined by the immunohistochemistry method. The expression of COX-2 protein was assessed by Western Blot. Analysis used the 2 test. The difference was regarded as significant when P value was less than 0.05. RESULTS： Seventeen percent （17/100） of H pyloriinfected MGs developed gastric cancer. All of these lesions were well-differentiated adenocarcinoma. The incidence rates of adenocarcinoma in groups A-F were 40%, 0%, 0%, 20%, 25%, and 0% respectively. The inflammatory scores were higher in group B than in other groups. There was no inflammatory response noted in group F. Celecoxib treatment resulted in a significant reduction in the proliferation of H pyloriinfected mucosal cells （groups B, C and D） （P 〈 0.01）. The expression of COX-2 protein was significantly attenuated in the groups which were Celecoxib-treated for more than 20 wk （groups B, C, D）. The groups treated with Celecoxib had a significantly lower rate of advanced gastric cancer （34% vs 75%, P 〈 0.001） There were no sudden deaths in any of the groups. CONCLUSION： Short-term treatment with Celecoxib has an anti-carcinogenic effect, and resulted in less severe inflammation and inhibited the invasive degree of gastric cancer.
文摘Tyrosinase is encoded by the Tyr (c or albino) locus and is the key enzyme in pigment biosynthesis. Loss of function of this enzyme caused by gene mutation results in albinism. Most cases of albinism are caused by missense mutations of tyrosinase. Albino mutations in Tyr have been identified in various animals, including human, mouse, rat, rabbit, cattle, cat, and ferret, but not in gerbil. We created two new gerbil strains: MON/Num/a (inbred agouti phenotype) and MON/Num/c (albino phenotype). Here, we report that four nucleotide substitutions in the Tyr gene caused two missense mutations in amino acids in the albino gerbil: a G-to-A mutation at position 204 in exon 1 caused R77H, and A-to-G at position 1392 and G-to-T at position 1393 in exon 5 caused Q473R. The substitution at position 1408 in exon 5 was silent. These missense mutations are conserved in all albino phenotypes we tested. Therefore, we suggest that these mutations are responsible for albinism in gerbil.
文摘Although various animal models have been developed to clarify gastric carcinogenesis, apparent mechanism of gastric cancer was not clarified in recent years. Since the recognition of the pathogenicity of Helocobacter pylori（H pylori）, several animal models with H pylori infection have been developed to confirm the association between Hpylori and gastric cancer. Nonhuman primate and rodent models were suitable for this study. Japanese monkey model revealed atrophic gastritis and p53 mutation after long-term infection of Hpylori. Mongolian gerbil model showed the development of gastric carcinoma with H pylori infection alone, as well as with combination of chemical carcinogens, such as N-methyl- N-nitrosourea and N-methyl-N-nitro-N＇-nitrosoguanidine. The histopathological changes of these animal models after H pylori inoculation are closely similar to those in human beings with Hpylori infection. Eradication therapy attenuated the development of gastric cancer in Hpylori- infected Mongolian gerbil. Although several features of animal models differ from those seen in human beings, these experimental models provide a starting point for further studies to clarify the mechanism of gastric carcinogenesis as a result of Hpylon infection and assist the planning of eradication therapy to prevent gastric carcinoma.
基金This work was supported by the National Natural Science Foundation of China(No.31970417 and 31772461)to DHWthe State Key Laboratory of Integrated Management of Pest Insects and Rodents(Grant No.IPM2004).
文摘Ambient temperature considerably affects the physiology and behavior of mammals.Thermosensory and thermoregulatory abilities play an important role in the response to changing ambient temperature in endotherms.However,the molecular mechanisms of behavioral thermoregulation remain poorly understood.Transient receptor potential vanilloid-1(TRPV1)is activated by changes in ambient temperature and is involved in acute thermoregulation.Here,we aimed to determine whether TRPV1 is involved in behavioral thermoregulation in wild rodents by conducting 2 experiments.In the first,42 adult Mongolian gerbils(Meriones unguiculatus;14 per treatment)were randomly assigned to 3 housing temperatures(4,23,and 36℃for 4 weeks.In the second,20 gerbils(10 per treatment)were randomly injected with capsaicin(TRPV1 agonist)or AMG517(TRPV1 antagonist).The results showed a significant decrease in food intake and non-shivering thermogenesis in the gerbils housed at 36℃.Additionally,there was a significant increase in the preference of gerbils housed at 4℃ to low temperatures.The expression of TRPV1 protein in the brown adipose tissue(BAT)and liver was significantly positively correlated with that of protein kinase A(PKA).The expression of TRPV1 and PKA proteins in the BAT was positively correlated with the temperature preference of the gerbils.The gerbils injected with capsaicin preferred significantly lower temperatures than the control group gerbils.These findings suggest that TRPV1 and PKA are involved in behavioral thermoregulation in Mongolian gerbils.
基金supported by National Key Basic Research and Development Program of China(No.2007CB109105).
文摘Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.
基金supported by the National Nature Science Foundation of China(81401102 to Liju Luan)National Nature Science Foundation of China(31571091 to Mingliang Pu)the National Basic Research Program of China(2016CB351806 to Mingliang Pu)
文摘The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.
