Experimental cholesteatoma: a comparison between spontaneous and induced models

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.

Mongolian Gerbils as a Model for the Study of Cholesteatoma: Otoendoscopic as a Diagnostic Tool

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.

Efecto de la isquemia cerebral permanente sobre la fascia dentada del hipocampo en gerbils / Effect of the permanent cerebral ischemia on the dentate fascia of the gerbils hypocampus

Se realizó un estudio prospectivo y experimental, a partir de la inducción de un trauma isquémico cerebral permanente, mediante sección de la carótida derecha, en 24 gerbils de Mongolia, procedentes del Centro Nacional para la Producción de Animales de Laboratorio, con vistas a identificar los posibles cambios en las poblaciones de neuronas de la fascia dentada del hipocampo durante la isquemia. Los resultados revelaron que la isquemia cerebral permanente produce destrucción progresiva y total de las neuronas en la fascia dentada durante las primeras 72 horas del proceso isquémico y muestra 3 momentos durante su evolución con características específicas para cada uno, así como cambios en las proporciones entre las neuronas en proceso de muerte celular, las aparentemente sanas y aquellas con diferentes cantidades de nucléolos en la zona dañada por el proceso isquémico.

A prospective and experimental study was carried out, from the induction of a permanent cerebral ischemic trauma, by means of a cut to the right carotid vein, in 24 gerbils from Mongolia, obtained from the National Center for Laboratory Animals Production, with the aim of identifying the possible changes in the neurons populations of the hypocampus dentate fascia during ischemia. The results revealed that the permanent cerebral ischemia produces progressive and total destruction of the neurons in the dentate fascia during the first 72 hours of the ischemic process and it shows 3 moments during its course, each of them with specific characteristics, as well as changes in the proportions among the neurons during cellular death, those apparently healthy and those with different quantities of nucleolous in the area damaged by the ischemic process.

Study of coxsackievirus A6 infection in Mongolian gerbils / 中华实验和临床病毒学杂志

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.

Fermentation of Cassava Leaves Improves Provitamin A Carotenoid Bioefficacy in Mongolian gerbils (Meriones unguculatus)

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.

Investigation of pathogen infections in Mongolian gerbils raised in a conventional facility / 中国比较医学杂志

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.

Establishment of an animal model for coxsackievirus A16 infection related immunological evaluation / 中国比较医学杂志

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 .

Preliminary study of intervention in effect of Bushen Huoxue recipe on calcification of lumbar vertebra cartilage endplate of the aging gerbils / 中国骨伤

<p><b>OBJECTIVE</b>To study the effect of Bushen Huoxue decoction on calcification of cartilage endplate in lumbar vertebrae.</p><p><b>METHODS</b>Six healthy male gerbils with 2-month-old were selected as normal control group, and 24 7-month-old healthy male gerbils were fed to 12-month-old to establish the aged gerbil model. Thirty gerbils were randomly divided into five groups as follow: the normal control group (=6), model group (=6, normal saline 4 ml/kg, intragastric 30 d), Bushen Huoxue low dose group(=6, 1.9× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), Bushen Huoxue middle dose group(=6, 3.8× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), Bushen Huoxue high dose group(=6, 7.6× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), the intervention group administered for 1.36 g from 7-month-old age, 30 d. The animals were sacrificed at the age of 2 months in the normal control group and 12 months of age in the other groups. The morphology of the lumbar vertebral cartilage endplate, the area of vascular bud, the ratio of non-calcified/calcified layer were analysis by HE chromosome visual method. The expression of type X collagen and BMPs in cartilage endplates were detected by rabbit monoclonal immunohistochemical staining.</p><p><b>RESULTS</b>The relative area of the vascular buds cartilage endplate measurements showed that compared with the model group, middle dose group and normal control group increased (<0.05), high and low dose groups all had different degrees of increase, but no statistical significance(>0.05). The ratio of cartilage endplate thickness of non-calcified/calcified showed that compared with the model group, Bushen Huoxue middle dose, normal control group increased, with statistical significance(<0.05), and high and low dose groups all had different degrees of increase, but there were no statistical significance(>0.05). Compared with the model group, the expression of type X collagen in the cartilage endplate of the normal group, the Bushen Huoxue low, middle and high dose groups decreased, and had statistical significance(<0.01); compared with the model group, the expression of BMPs in the normal group, Bushen Huoxue middle dose group increased, with statistically significant(<0.01), while the high and low dose groups increased in different degrees, but there was no statistical significance(>0.05).</p><p><b>CONCLUSIONS</b>Bushen Huoxue prescription can delay the calcification of cartilage endplate in the process of aging, suggesting that it can be used as a preventive medicine for early disc degeneration.</p>

Neurovestibular Compensation following Ototoxic Lesion and Labyrinthectomy

Abstract Introduction Unilateral labyrinthectomy and intra-tympanic gentamycin have been employed in the treatment of Ménière's disease, but the efficacy of these techniques has not been well established. Objective The objective of this study is to measure the time course of recovery from a unilateral labyrinthectomy either after ipsilateral topical treatment with gentamicin to the inner ear or without the previous insult. Methods Twenty-nine adult Mongolian gerbils were randomized into two experimental groups. Group 1 (n=17) received a right ear gentamicin drug-induced lesion by unilateral labyrinthectomy (UL). Group 2 (n=12) only received a right unilateral labyrinthectomy lesion. We measured the horizontal vestibulo-ocular responses in gerbils before and after the lesion. The gerbils received an angular acceleration stimulus and their eye movements were recorded. Results The gentamicin lesion resulted in a quicker recovery. Experimental groups underwent a similar time course of recovery. Statistical analysis showed no significant difference between the two groups. Both groups displayed adaptation to the lesion by day 21, but long-term compensation did not completely revert to the original pre-lesion state. Conclusions In a lesion requiring both static and dynamic compensation as in UL, the need for a static compensation may alter pre-existing compensation from a previous dynamic insult and require a new compensation. A previous lesion and adaptation is not preserved for a second lesion and the subject has to re-compensate. Therefore, surgical treatment in Meniere's disease such as UL can be considered without prior gentamicin treatment. Static and dynamic compensations do not appear to be as independent as previous studies have suggested.

Lycopene supplementation suppresses oxidative stress induced by a high fat diet in gerbils

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.

PATRONES DE ALIMENTACIÓN, SUEÑO Y ACTIVIDAD REPRODUCTIVA EN JERBOS DE MONGOLIA (Meriones unguiculatus) / PATTERNS OF FEEDING, SLEEP AND REPRODUCTIVE BEHAVIOR IN MONGOLIAN GERBILS (Meriones unguiculatus)

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.

Effects of Tadalafil on the Cerebral Ischemia-induced Apoptotic Neuronal Cell Death in Motor Cortex of Gerbils / 대한남성과학회지

PURPOSE: Cerebral ischemia leads to neuronal cell death, and eventually causes neurological impairments. Tadalafil is a long-acting phosphodiesterase type-5 (PDE-5) inhibitor, and it has been used for the treatment of erectile dysfunction. In the present study, we investigated whether tadalafil has the protective effect on apoptotic neuronal cell death in the motor cortex following transient global ischemia in gerbils. MATERIALS AND METHODS: For this study, Mongolian gerbils were used for the experimental animals, and transient global ischemia was induced to the gerbils by occlusion of both common carotid arteries for 7 min. Gerbils were randomly divided into five groups (n=8 in each group): the sham-operation group, the cerebral ischemia-induced group, the cerebral ischemia-induced and 0.1 mg/kg tadalafil-treated group, the cerebral ischemia-induced and 1 mg/kg tadalafil-treated group, the cerebral ischemia-induced and 10 mg/kg tadalafil-treated group. Tadalafil-treated groups received tadalafil orally once a day for a 7 consecutive days, starting one day after surgery. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspase-3 were performed for the detection of apoptotic neuronal cell death in the motor cortex. RESULTS: The number of TUNEL-positive cells was 21.45+/-3.69/section in the sham-operation group, 771.66+/-97.25/section in the cerebral ischemia-induced group, 688.44+/-81.35/section in the cerebral ischemia-induced and 0.1 mg/kg tadalafil-treated group, 295.66+/-36.34/section in the cerebral ischemia-induced and 1 mg/kg tadalafil-treated group, and 198.47+/-25.25/section in the cerebral ischemia-induced and 10 mg/kg tadalafil-treated group. In the present results, induction of ischemic injury increased apoptotic neuronal cell death in the motor cortex of gerbils. However, tadalafil treatment suppressed the cerebral ischemia-induced apoptotic neuronal cell death in the motor cortex as dose-dependently. CONCLUSIONS: Here in this study, we showed that tadalafil has protective effect on the cerebral ischemia-induced apoptotic neuronal cell death, and thus this drug may facilitate the recovery following ischemic cerebral injury.

Ocular lesions in gerbils (Meriones unguiculatus) infected with low larval burden of Toxocara canis: observations using indirect binocular ophthalmoscopy / Lesões oculares em gerbils (Meriones unguiculatus) infectados com baixo número de larvas do Toxocara canis: observações com oftalmoscopia binocular indireta

To study the frequency of ocular lesions in 30 gerbils infected with 100 embryonated eggs of Toxocara canis, indirect binocular ophthalmoscopy was performed 3, 10, 17, 24, 31 and 38 days after infection. All the animals presented larvae in the tissues and 80 percent presented ocular lesions. Hemorrhagic foci in the choroid and retina were present in 92 percent of the animals with ocular lesions. Retinal exudative lesions, vitreous lesions, vasculitis and retinal detachment were less frequent. Mobile larvae or larval tracks were observed in four (13.3 percent) animals. Histological examination confirmed the ophthalmoscopic observations, showing that the lesions were focal and sparse. In one animal, there was a larva in the retina, without inflammatory reaction around it. The results demonstrated that gerbils presented frequent ocular lesions after infection with Toxocara canis, even when infected with a small number of embryonated eggs. The lesions observed were focal, consisting mainly of hemorrhages with signs of reabsorption or inflammation in different segments of eye, and differing from the granulomatous lesions described in ocular larva migrans in humans.

Para verificar a freqüência de lesões oculares em 30 gerbils infectados com 100 ovos larvados de Toxocara canis foi realizada a oftalmoscopia binocular indireta nos dias 3, 10, 17, 24, 31 e 38 após a infecção.Todos os animais apresentavam larvas nos tecidos e 80 por cento apresentavam lesões oculares, dos quais 92 por cento tinham lesões hemorrágicas focais na coróide e na retina. Lesões exudativas da retina, lesões do vítreo, vasculite e descolamento da retina foram menos freqüentes. Larva móvel ou traços de larva em quatro (13,3 por cento) animais. O estudo histológico confirmou as observações da oftalmoscopia, mostrando que as lesões eram focais e esparsas. Em um animal havia uma larva na retina, sem reação inflamatória em torno dela. Os resultados demonstraram que os gerbils apresentam freqüentes lesões oculares após infecção com o Toxocara canis mesmo quando infectados com pequeno número de ovos larvados. As lesões observadas eram focais, principalmente focos de hemorragia com sinais de reabsorção ou focos de inflamação nos diferentes segmentos do olho, diferentes das lesões granulomatosas descritas na larva migrans ocular humana.

Loss of infectivity of Neospora caninum oocysts maintained for a prolonged time

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.

Changes of Antioxidant Activities on Z:ZCLA Mongolian Gerbils' Sera within Different Growth Period / 医学研究杂志

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.

Protective effects of penehyclidine hydrochloride on transient forebrain ischemia reperfusion injury in gerbils / 中国临床药理学与治疗学

AIM:To study the protective effects of penehyclidine hydrochloride(PHC) on transient forebrain ischemia reperfusion injury in gerbils.METHODS:The model of transient forebrain ischemia reperfusion was established in gerbils by bilateral carotid artery clamping.The effects of PHC on neurological function scores and the morphous of hippocampal pyramidal neuron of gerbils were observed after receiving transient forebrain ischemia reperfusion.SOD activities and contents of MDA in the hippocampus and cortex of gerbils were measured.RESULTS:In the groups of PHC(0.08),(0.24)(mg?kg~(-1)) and atropine,the stroke index was decreased,compared with the ischemia-reperfusion group after the gerbils received transient forebrain ischemia reperfusion for six hours.PHC could reduce the degree of injury in hippocampal pyramidal neuron after ischemia reperfusion for three days.CONCLUSION: PHC has protective effects on transient forebrain ischemia reperfusion injury in gerbils.

Effects of Buyang Huanwu Decoction and Radix Astragali On Astrocytes in Gerbils with Cerebral Ischemia and Reperfusion Injury / 广州中医药大学学报

[Objective] To study the effects of Buyang Huanwu Decoction and Radix Astragali on astrocytes in gerbils with cerebral ischemia and reperfusion injury. [Methods] Gerbils model of cerebral ischemia was set up by occlusion of bilateral common carotid arteries. The dynamic expression of glial fibrillary acidic protein (GFAP) were determined by immunohistochemical method in reperfusion for 24 and 48 hours after 15 minutes of cerebral ischemia. [Results] Positive expression of GFAP reached a peak in reperfusion for 24 hours and was decreased by Buyang Huanwu Decoction and Radix Astragali. Positive GFAP expression was attenuated in reperfusion for 48 hours and enhanced by Buyang Huanwu Decoction and Radix Astragali increased the expression. [ Conclusion ] The regulatory effect of Buyang Huanwu Decoction and Radix Astragali on astrocytes may be one of its mechanisms in repairing nervous function after cerebral ischemia.

The Effects of brain ischemia induced by bilateral carotid artery occlusion on microcirculation of the cerebral cortex of mongolian gerbil

BACKGROUND AND PURPOSE: The present study was carried out to investigate transient arteriolar vasospasm following reperfusion in the gerbil as an ischemic model and relationship between vasospasm and the changes of morphologic, physiologic and regional blood flow. METHODS: The transient arteriolar vasospasm was observed under the microscope. All gerbils were perfusion fixed and ischemic neuronal damage was checked in the CA1 subfield of the dorsal hippocampus. Metabolic parameters were serially measured during the occlusion and after recirculation, and cerebral blood flow was measured with a laser Doppler flowmetry. RESULTS: 1. Among the 18 gerbils with BCAO(bilateral carotid artery occlusion) for 2 minutes, 8 gerbils showed vasospasm after reopening, namely post-ischemic vasospasm, and 10 gerbils did not show vasospasm. 2. In all animals, metabolic parameters showed decreased PaCO2 and high pH just after the occlusion but increased PaCO2 and lowered pH following the recirculation. BCAO caused marked increase in systemic blood pressure but it returned to preischemic levels following the recirculation. 3. In all animals, BCAO caused marked decrease of cerebral blood flow compared to preischemic levels immediately following the occlusion but it returned to preischemic levels following the recirculation. And it took some longer the onset and duration of the transient increase in blood volume after reopening in the animals with vasospasm than those without vasospasm. 4. There was no morphological neuronal damage in the hippocampal CA1 subfield, at 1, 3, 7 days following 2-minute ischemic insult. CONCLUSION: The present study confirmed that BCAO in gerbils resulted in forebrain ischemia caused transient cortical vasospasm in the gerbil. But there was no close relationship between vasospasm and the changes of morphologic, physiologic and regional blood flow.

Free radicals in delayed neuronal damage and prevention / 中国病理生理杂志

In the present study, Mongolian gerbil was used to make delayed neuronal damage (IND) animal model. In 6 different brain regions, 5 kinds of biochemical indexes in the aspect of free radical metabolism were measured at 7 time phases during ischemia and reperfusion. The results showed that, after transient cerebral ischemia and during reperfusion, some unique changes appeared tn hippocampal CA1 sector, which were characterized by the persistent increase of free radical content and persistent decrease of the Mn-SOD activity. The fluctuating changes could be seen in Cu, Zn-SOD activity and lipid peroxide content. There were no significant changes in the brain regions other than CA1 sector. It is concluded that the disturbance of free radical metabolism play a key role in the occur. fence of DND. It was also observed that Aniracetam, Helicid and Nieardipine had some control effects to a certatn extent on the free radical disturbance above in hippocampal CA1 sector of DND animals.

The Effect of Arginine Vasopressin on ?-endorphin and Dynorphin A_(1-13) Contents in Cerebral Ischemic Regions of Mongolian gerbils / 第二军医大学学报

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.