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Abstract Objective: To compare the incidence and the histopathological aspect of spontaneous and two induced Mongolian gerbils' models of cholesteatoma: External Auditory Canal (EAC) obliteration model and the Auditory Tube (AT) cauterization model. Methods: Fifty-four ears of 27 animals were divided into EAC obliteration, AT cauterization, and control groups and histologically assessed for cholesteatoma incidence and classification at intervals of 2, 4, 8, and 16 weeks. Results: Cholesteatoma was diagnosed in 30 of the 53 ears evaluated with a significantly higher incidence in groups that received some type of intervention (p < 0.0001). It was not possible to histologically distinguish cholesteatomas of the same stage between the study groups. Conclusion: Although we observed a significant increase in cholesteatoma incidence with the two methods used when compared to the control group, all developed cholesteatomas were apparently identical from a histological point of view.
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Abstract Introduction Cholesteatoma is a disease with significant clinical impact but is incompletely understood. The challenge of performing studies with long-term follow-up in humans is a factor that has restricted the advance of knowledge in this field. Thus, the use of animal models is highly pertinent, and the Mongolian gerbil model has emerged as one of the most useful. Objective The present study aims to evaluate, through serial otoendoscopies, the development and characteristics of pars flaccida retraction pocket and cholesteatoma in Mongolian gerbils after obliteration of the eustachian tube and compare it with the control group. Methods Forty Mongolian gerbils were divided into two groups of 20 animals each. In the intervention group, the animals were followed with serial otoendoscopies after eustachian tube obliteration. In the control group, the animals were only followed through serial otoendoscopies. Results At the end of the 16-week follow-up, cholesteatoma was present in 13 of 38 (34.2%) ears in the intervention group, and in 7 of 34 (20.6%) in the control group (p = 0.197). When we considered cholesteatoma and its potential precursor, pars flaccida retraction pocket, in a combined way, we verified it in 23 of 38 (60.8%) in the intervention group and in 11 of 34 (32.3%) in the control group (p = 0.016). Conclusions Over the 16 weeks of follow-up, serial otoendoscopies enabled us to evaluate the formation and development of pars flaccida retraction pockets and cholesteatomas in Mongolian gerbils and proved to be an excellent diagnostic tool.
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Objective@#To study infection of coxsackievirus A6 (CV-A6) in Mongolian gerbils.@*Methods@#To screen the optimal ages of Mongolian gerbils, five groups with different ages were infected with 1×105 TCID50 dose of CV-A6 XS45 strain by intraperitoneal, and symptom scores of Mongolian gerbils were collected. Then to estimate the dose-effect, three doses of virus were injected to the Mongolian gerbils. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry(IHC) were used to determine virus load and tissues infection in muscle, brain and intestinal tract.@*Results@#Mongolian gerbils infected with 1×105 TCID50 dose CV-A6 consistently exhibited clinical signs, and the morbidity (death) rates of five age groups were up to 100%. There was a positive correlation between the trend of symptom scores changes and ages. The morbidity (death) rates of three doses (1×103 TCID50, 1×104 TCID50, 1×105 TCID50) also were up to 100% in 28 days Mongolian gerbils. The correlation between the trend of symptom scores changes and doses were negative. Virus loads were detected in muscle, brain and intestinal tract of pathogenesis animal. The virus loads of muscle were higher than others. IHC results showed virus infection and cytopathic effects in three tissues.@*Conclusions@#Mongolian gerbils had high susceptibility to CV-A6, and were best for animal model of CV-A6 infection.
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Aims: The aim of this study was to evaluate the effect of fermented cassava leaves used as diet on provitamin A carotenoid bioefficacy. Study Design: Carotenoid analysis of fermented (F) and non-fermented (NF) cassava leaves, feeding Mongolian gerbils with F and NF leaves and β-carotene bioconversion evaluation. Place and Duration of Study: Felix Houphouet-Boigny University, Abidjan (March to August 2015) and University of Wisconsin-Madison, USA (March to June 2016). Methodology: Fermented cassava leaves were fed to Mongolian gerbils (Meriones unguculatus) and compared with non-fermented leaves and controls. Gerbils (32 days old, n = 46) were vitamin A (VA)-depleted for 3 weeks. After depletion, baseline gerbils (n = 6) were killed and remaining gerbils (n = 40) were weight-matched to 4 groups (n = 10/group) in the following treatments: VA-free feed (VA-); non-fermented leaves (NF); fermented leaves (F); and VA-free feed with daily oral doses of retinyl acetate dissolved in oil (VA+). The feeds were prepared using F and NF leaves at 3.53 and 4.27%, respectively, to equalise daily theoretical VA intake at 35 nmol β-carotene/g feed. Serum and livers were analysed using UPLC®. Results: The daily feed intake from the F and NF groups did not differ (4.38 ± 0.40 g). Serum retinol concentrations did not differ among groups, but the VA+ group had higher liver retinol (1.39 ± 0.32 μmol/liver) than the F and NF groups (P < 0.05). The calculated bioconversion factors were 13 and 37 µg β-carotene equivalents to 1 µg retinol for the F and NF groups, respectively. Conclusion: This study showed that the provitamin A carotenoids from small quantities of F and NF leaves were effective at maintaining VA status of gerbils when assessed by liver stores.
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Objective To establish a simple and reliable experimental rodent model sensitive to coxsackievirus A16 ( CVA16) .Methods Mongolian gerbils with different age were selected and inoculated intraperitoneally with live CVA16, and the gerbils were observed daily until 14 days postinoculation to screen for the most optimal ages sensitive to the virus.The dose-dependent symptoms were evaluated and the 50% lethal dose (LD50) was determined.The virus titers were measured in blood and various tissues of CVA 16-infected Mongolian gerbils 3 days post-infecton.Finally, the gerbils were immunized twice with inactivated CVA 16 vaccine at day 1 and day 11, respectively, followed by challenge with the virus with a dose of LD50 at day 14.The gerbils were then observed for another 2 weeks to record their body weight , symptom and mortality rate .Their blood samples were collected from the eyes , and CVA16-specific neutralizing antibodytiters and total antibody titers was checked by microneutralization test and ELISA , respectively .Results Various clinical symptoms, such as inactivity, hind limb weakness, paralysis and even death occurred in gerbils following CAV 16 infection. 7-day-old and 14-day-old gerbils are susceptible to CVA 16 infection whereas 28-day-old gerbils are resistant .The most sensitive and appropriate age is 14-day-old.The 50%lethal dose was determined to be 1×104.5 CCID50.High titers of the virus were confirmed in blood and various tissues of Mongolian gerbils contracted CAV 163 days post-infecton.The survival rate is 87.5%for 14-day-old gerbils preimmunized with two doses of inactivated CVA 16 vaccine and challenged with the virus.The geometric mean titers ( GMTs) of neutralizing antibody was 28.14, and the seroprevalence was 87.5%.Conclusions Mongolian gerbils is sensitive to CVA16 and the virus reproduces actively in Vivo.Thus, it can be used as a reliable small animal model for studies of CVA 16 pathogenesis , vaccine development and drug evaluation .
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Objective To investigate the pathogen infections of Mongolian gerbils raised in a conventional facility,and to provide a basis for the establishment of local standards for pathogen detection in Mongolian gerbils. Methods A total of 16 species of bacteria,11 species of viruses and 8 species of parasites were detected in 30 gerbils raised in a conventional facility, according to the national standards of microorganism and parasite detection in mice and rats. Results Gerbils raised in this conventional facility were infected with lymphocytic choriomeningitis virus(a positive rate of 6. 7%), sendai virus(3. 3%), pneumonia virus of mice(100. 0%), reovirus type III(6. 7%), mouse encephalomyelitis virus(10. 0%), mycoplasma spp.(6. 7%), Tyzzer's organism(6. 7%)and Helicobacter spp. (56.7%),according to our antibody detection results. Meanwhile,the detected positive rate of Pasteurella pneumotropica was 3.3%,Staphylococcus aureus 10.0%,Escherichia coli O115 a,C,K(B)6.7%,Tritrichomonas muris 100.0% and flagellates 100.0%. Conclusions The results of our study provide a reference for the establishment of classification standards for gerbils according to their pathogen and parasite infections.
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The effect of lycopene supplementation on the antioxidant system was investigated by analyzing lipid peroxide levels, glutathione contents, and antioxidant enzyme activities in Mongolian gerbils fed a high fat diet. Gerbils were fed on each experimental diet for 6 weeks; normal diet (NC), normal diet with 0.05% lycopene (NL), high fat diet (HF), and a high fat diet with 0.05% lycopene (HFL). Dietary supplementation of lycopene increased hepatic lycopene level in gerbils fed a normal or high fat diet (P < 0.05). Liver and erythrocyte concentrations of lipid peroxide increased in gerbils fed a high fat diet, whereas lycopene supplementation decreased liver and erythrocyte concentrations of lipid peroxide (P < 0.05). Hepatic total glutathione content was higher in the NL group than that in the NC group (P < 0.05). Total antioxidant status in plasma increased following lycopene supplementation compared with that of the non-lycopene supplemented groups (P < 0.05). Hepatic catalase activity increased following dietary lycopene supplementation (P < 0.05). Superoxide dismutase activity in liver remained unchanged with lycopene supplementation, but erythrocyte superoxide dismutase activity increased in NL group compared with NC group (P < 0.05). Glutathione-S-transferase activity increased in the NL group compared to NC group (P < 0.05). Liver and erythrocyte glutathione peroxidase activity increased significantly in the NL group compared to that in the HF group (P < 0.05). Liver glutathione reductase activity was higher in the NL group than that in the NC group (P < 0.05). These results suggest that lycopene supplementation may be efficient for preventing chronic diseases induced by oxidative stress related to high fat diet.
Subject(s)
Carotenoids , Catalase , Chronic Disease , Diet , Diet, High-Fat , Dietary Supplements , Erythrocytes , Gerbillinae , Glutathione , Glutathione Peroxidase , Glutathione Reductase , Liver , Oxidative Stress , Plasma , Superoxide DismutaseABSTRACT
Los jerbos de Mongolia son roedores utilizados como excelente modelo biológico. A pesar de esto, su clasificación como especie diurna, nocturna o crepuscular no ha sido clara. Los experimentos que se presentan en este artículo evaluaron patrones de alimentación, sueño-actividad y actividad reproductiva y copulativa en condiciones de luz/oscuridad 12:12 en Jerbos de Mongolia. Los resultados de los experimentos sugieren un patrón nocturno de comportamiento en estos roedores.
Mongolian Gerbils are often used as a biological model, but it remains unclear whether these rodents display nocturnal, diurnal, or crepuscular patterns of behavior. The experiments presented below studied patterns of sleep-activity, feeding, and reproductive behavior under 12:12 light dark cycles. All data from these experiments suggest a nocturnal pattern of behavior in these rodents.
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The purpose of this study was to investigate whether sporulated Neospora caninum oocysts, which had been stored for 46 mo in a 2% sulfuric acid solution at 4 degrees C, remain morphologically viable and infective to gerbils (Meriones unguiculatus). Six gerbils were orally inoculated with doses of 400 or 1,200 oocysts. Two mo after inoculation, the animals did not show any clinical signs, had no histological lesions, and were seronegative for N. caninum at 1: 50 in an immunofluorescent antibody test. PCR using the brain from each gerbil did not reveal N. caninum specific DNA. We conclude that oocysts preserved for 46 mo are not infective, despite being morphologically intact.
Subject(s)
Animals , Female , Acids , Brain/parasitology , Cattle/parasitology , Coccidiosis/parasitology , Feces/parasitology , Gerbillinae/parasitology , Neospora/genetics , Oocysts/growth & development , Polymerase Chain Reaction/methods , Refrigeration , VirulenceABSTRACT
Objective To study the changes of antioxidant on ZCLA Mongolian gerbils' sera within different growth period.Methods The gerbils at the age of 1 month,3 months and 24 months were used in the experiment,with each 16(half male and half female),and the sera were collected for determining the MDA,SOD and GSH-Px.Results At the age of 3 months,MDA was the lowest,but GSH-Px was the highest,while the SOD was ascending with growing.Conclusion The changes of GSH-Px showed the direct relation to MDA,while the changes of the SOD was irrespective to the changes of MDA.
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The effects of arginine vasopressin (AVP) on the contents of ir-?-EP and ir-Dyn A1-13 in ischemic brain regions of Mongolian gerbils were observed with radioimmunoassay in this study.The results showed that the contents of ir-?-EP were significantly increased and those of ir-Dyn A1-13 were decreased in ischemic cortex and hypothalamus after injection of AVP into the lateral ventricle. However, the contents of ir-?- EP were markedly decreased and those of ir-Dyn A1-13 were unchanged significantly in the ischemic cortex and hypothalamus after intraventricular infusion of AVP antiserum.