Cuspal Shape Alterations by Bmp4 Directing Cell Proliferation and Apoptosis.

The enamel knot (EK), located at the center of cap stage tooth germs, is a transitory cluster of nondividing epithelial cells. The EK acts as a signaling center that provides positional information for tooth morphogenesis and regulates the growth of tooth cusps. To identify species-specific cuspal patterns, this study analyzed the cellular mechanisms in the EK that were related to bone morphogenetic protein (Bmp), which plays a crucial role in cell proliferation and apoptosis. To understand the cellular mechanisms in the EK, the differences between 2 species showing different cuspal patterning, mouse (pointy bunodont cusp) and gerbil (flat lophodont cusp), were analyzed with quantitative reverse transcriptase polymerase chain reaction and immunofluorescent staining. Based on these, we performed protein-soaked bead implantation on tooth germs of the 2 different EK regions and compared the cellular behavior in the EKs of the 2 species. Many genes related with cell cycle, cell apoptosis, and cell proliferation were involved in BMP signaling in the EK during tooth development. A comparison of the cell proliferation and apoptosis associated with Bmp revealed distinctive patterns of the cellular mechanisms. Our findings indicate that the cellular mechanisms, such as cell proliferation and apoptosis, in the EK are related to Bmp4 and play an important role in tooth morphogenesis.

Comparative Mitogenome Analysis of Gerbils and the Mitogenome Phylogeny of Gerbillinae (Rodentia: Muridae).

To enrich the mitogenomic database of Gerbillinae (Rodentia: Muridae), mitogenomes of three gerbils from different genera, Meriones tamariscinus (16,393 bp), Brachiones przewalskii (16,357 bp), and Rhombomys opimus (16,352 bp), were elaborated and compared with those of other gerbils in the present study. The three gerbil mitogenomes consisted of 2 ribosomal RNA genes, 13 protein-coding genes (PCGs), 22 transfer RNA genes, and one control region. Here, gerbil mitogenomes have shown unique characteristics in terms of base composition, codon usage, non-coding region, and the replication origin of the light strand. There was no significant correlation between the nucleotide percentage of G + C and the phylogenetic status in gerbils, and between the GC content of PCGs and the leucine count. Phylogenetic relationships of the subfamily Gerbillinae were reconstructed by 7 gerbils that represented four genera based on concatenated mitochondrial DNA data using both Bayesian Inference and Maximum Likelihood. The phylogenetic analysis indicated that M. tamariscinus was phylogenetically distant from the genus Meriones, but has a close relationship with R. opimus. B. przewalskii was closely related to the genus Meriones rather than that of R. opimus.

Advances in research on the biology of the desert rodent Gerbillus tarabuli: a review.

Selection of the appropriate species and strain of laboratory animals are among the scientist's major concerns. Tarabul's gerbil (Gerbillus tarabuli) is a small, seasonally breeding, desert rodent native to Africa. Despite its unique biological features, which make it an ideal model candidate for biomedical research, only a few reports have used it in research. Hence, the present review aims to provide more data about this species, covering all aspects of its biology, such as taxonomy, morphology, anatomy, ecology, wildlife biology, molecular biology, physiology, neurobiology, genetics, reproduction, development, evolutionary biology, and conservation biology, and covers current progress in exploration of G. tarabuli, discussing its valuable characteristics, which are widely useful for research in various fields. This review paper is destined for biologists, scientists, mammologists, zoologists, academics, and students.

Prenatal and pubertal exposure to 17α-ethinylestradiol disrupts folliculogenesis and promotes morphophysiological changes in ovaries of old gerbils (Meriones unguiculatus).

17α-Ethinylestradiol is an endocrine-disrupting chemical that make up most contraceptive pills and can be found in the environment. Exposure to ethinylestradiol in different development periods may promote changes in morphophysiological parameters of reproductive and endocrine organs. Considering that the effects of low doses (15 µg/kg/day) of ethinylestradiol in ovaries from 12-month-old female gerbils (Meriones unguiculatus) were investigated. Four experimental groups used were control (without treatment), EE/PRE (treated from the 18th to the 22nd gestational day), EE/PUB (treated from the 42nd to the 49th day of life), and EE/PRE-PUB (treated in the both periods). The animals were euthanized at 12 months. Testosterone and 17ß-estradiol levels were measured. The ovaries were stained with Hematoxylin and Eosin, Periodic Acid Schiff, and Gomori's Trichome. The follicles, corpus luteum, interstitial gland, lipofuscin, ovarian epithelium, and tunica albuginea were analyzed. Estradiol was higher in EE/PRE and EE/PUB groups, while testosterone was higher only in EE/PUB group. The main changes in follicle count occurred in EE/PUB and EE/PRE-PUB groups, with higher primordial follicle count and lower maturation of follicles. The corpus luteum was more evident in EE/PRE group. No differences were found in atretic follicles count. A higher area occupied by interstitial gland cells and lipofuscin deposit in these cells was noted in EE/PUB and EE/PRE-PUB groups. Higher epithelium height and thicker tunic albuginea were showed in treated groups. These results suggest that exposure to doses of EE2 in prenatal and pubertal periods of the development leads to morphological changes in senile ovaries.

Research-Relevant Conditions and Pathology of Laboratory Mice, Rats, Gerbils, Guinea Pigs, Hamsters, Naked Mole Rats, and Rabbits.

Animals are valuable resources in biomedical research in investigations of biological processes, disease pathogenesis, therapeutic interventions, safety, toxicity, and carcinogenicity. Interpretation of data from animals requires knowledge not only of the processes or diseases (pathophysiology) under study but also recognition of spontaneous conditions and background lesions (pathology) that can influence or confound the study results. Species, strain/stock, sex, age, anatomy, physiology, spontaneous diseases (noninfectious and infectious), and neoplasia impact experimental results and interpretation as well as animal welfare. This review and the references selected aim to provide a pathology resource for researchers, pathologists, and veterinary personnel who strive to achieve research rigor and validity and must understand the spectrum of "normal" and expected conditions to accurately identify research-relevant experimental phenotypes as well as unusual illness, pathology, or other conditions that can compromise studies involving laboratory mice, rats, gerbils, guinea pigs, hamsters, naked mole rats, and rabbits.

Camouflage accuracy in Sahara-Sahel desert rodents.

Camouflage helps animals to hide from predators and is therefore key to survival. Although widespread convergence of animal phenotypes to their natural environment is well-established, there is a lack of knowledge about how species compromise camouflage accuracy across different background types in their habitat. Here we tested how background matching has responded to top-down selection by avian and mammalian predators using Sahara-Sahel desert rodents in North Africa. We show that the fur colouration of several species has become an accurate match to different types of desert habitats. This is supported by a correlation analysis of colour and pattern metrics, investigation of animal-to-background similarities at different spatial scales and is confirmed by modelling of two predator vision systems. The background match was closest across large (or global) spatial scales, suggesting a generalist camouflage tactic for many background types. Some species, may have a better match to the background over small (or focal) spatial scales, which could be the result of habitat choices or differential predation. Nevertheless, predicted discrimination distances of fur colouration were virtually indistinguishable for mammalian and low for avian vision model, which implies effective camouflage. Our study provides one of the best documented cases of multilevel camouflage accuracy in geographically widespread taxa. We conclude that background matching has become an effective and common adaptation against predatory threat in Sahara-Sahelian desert rodents.

Molecular assessment of Bartonella in Gerbillus nanus from Saudi Arabia reveals high levels of prevalence, diversity and co-infection.

Bartonellae bacteria are associated with several re-emerging human diseases. These vector-borne pathogens have a global distribution, yet data on Bartonella prevalence and diversity in the Arabian Peninsula are limited. In this study we assessed the Bartonella infection status of the Baluchistan gerbil (Gerbillus nanus), a species associated with pastoral communities throughout the Middle East region, using a multi-gene PCR screening approach. The results demonstrated that 94 (68.1%) of the 138 gerbils trapped on a monthly basis, over a period of one year, were PCR-positive. Sequencing of the gltA gene region confirmed the presence of four discrete Bartonella lineages (I-IV) and high levels of co-infection (33.0%). Each of the four lineages, varied in overall abundance (7.5%-47.9%) and had discernible seasonal peaks. Bartonella status was significantly correlated with ectoparasite presence, but not with sex, nor with season. Statistical analyses further revealed that co-infected individuals had a significantly higher relative body condition. Multi-locus sequence analysis (MLSA) performed with a concatenated dataset of three genetic loci (gltA, nuoG, and rpoB), 1452 nucleotides (nt) in length confirmed that lineage IV, which occurred in 24 PCR-positive animals (25.5%), is most closely related to zoonotic B. elizabethae. The remaining three lineages (I-III) formed a monophyletic clade which, on the basis of gltA was shown to contain bartonellae from diverse Gerbillinae species from the Middle East, suggestive of a gerbil-associated species complex in this region. Lineage I was identical to a Candidatus B. sanaae strain identified previously in Bushy-tailed jirds (Sekeetamys calurus) from Egypt, wherease MLSA indicate that lineages II and III are novel. The high levels of infection and co-infection, together with the presence of multiple Bartonella lineages indicate that Gerbillus nanus is likely a natural reservoir of Bartonella in the Arabian Peninsula.

[Dynamics of F1 antibody responses to Yersinia pestis infection in Rhombomys opimus].

Objective: To observe the dynamics of antibody response in great gerbils infected with Yersinia pestis in experiment. Method: A total of 211 great gerbils were captured in the southern margin of plague natural focus of Junggar Basin of the Xinjiang Uygur Autonomous Region in 2011. Among them, there were 167 great gerbils without infection of Y. pestis and 44 great gerbils infected by Y.pestis. Y.pestis No. 2504 was employed for this experimental strain, which was strong toxic strain with negativity in the reduction experiment of nitrate. 35 great gerbils without the infection of Y. pestis were divided randomly and averagely into 7 groups including 6 experimental groups and 1 control group. Great gerbils in the 1st to 6th experimental groups were exposed first with 1 × 10(6)-1 × 10(11) CFU/ml of bacterial fluid with 10 times of gradient dilution; groin areas of great gerbils in the control group were injected subcutaneously with physiological saline; and the amount of infection was all 1 ml. 17 great gerbils infected with Y. pestis and the first detection of F1-antibody titer in 1∶256-1∶4 096 were grouped according to F1-antibody titer: group 1∶4 096 (n=4), group 1∶2 048 (n=4), group 1∶1 024 (n=3), group 1∶512 (n=3) and group 1∶256 (n=3); and blood in caudal regions was collected in asepsis for the detection of F1-antibody, with a total of 5 times. 9 great gerbils which were selected from the remaining great gerbils infected with Y. pestis and detected F1-antibody negative 2 times were exposed 1×10(6) CFU/ml of bacterial fluid for the second infection, with the amount of infection being 1 ml. Blood in caudal regions of great gerbils after the first and second infection were collected for the detection of plague F1-antibody on the 3rd, 5th, 7th, 15th, 30th, 60th, 90th and 120th day after infection. Declined regression models for great gerbils' antibodies were established with unary linear regression equation; declined change diagrams for the antibodies were drawn to observe the declined F1-antibody after great gerbils were exposed to Y. pestis. Results: In great gerbils with the first infection of Y. pestis, antibodies were detected in the 1 × 10(6)-1 × 10(8) CFU/ml of group on the 30th, 15th and 15th day, respectively; the positive rates of antibody were 1/4, 3/4 and 4/5, respectively; the group 1×10(7) and 1× 10(8) CFU/ml reached to the highest antibody titer with 1∶256 on the 120th day; antibodies were revealed in the group 1×10(9), 1×10(10) and 1×10(11) CFU/ml from the 5th to 7th day when the seroconversion of all antibodies was observed; group 1×10(11) CFU/ml reached to the highest antibody titer on the 120th day with 1∶4 096. In the great gerbils with the second exposure to Y.pestis, positive antibodies were detected on the 3rd day with the positive rate being 2/9; and the highest antibody titer with 1∶2 048 was noted on the 90th day. Unary linear regression equation of declined F1 antibody of great gerbils was y=0.045x- 0.321 (F=115.40, P< 0.001), and the shortest duration for F1-antibody titer declining from 1∶4 096 to 0 was 140 d and the longest duration 200 d. Conclusion: Great gerbils infected with the high concentration of Y. pestis fluid show shorter duration in producing F1-antibody, the antibody positive rate is also higher, and the highest antibody titer can reach 1∶4 096. The great gerbils could hold the plague F1 antibodies for a long time which was about 140 to 200 days from the highest titer.

Dynamics of F1 antibody responses to Yersinia pestis infection in Rhombomys opimus / 中华预防医学杂志

Objective@#To observe the dynamics of antibody response in great gerbils infected with Yersinia pestis in experiment.@*Method@#A total of 211 great gerbils were captured in the southern margin of plague natural focus of Junggar Basin of the Xinjiang Uygur Autonomous Region in 2011. Among them, there were 167 great gerbils without infection of Y. pestis and 44 great gerbils infected by Y.pestis. Y.pestis No. 2504 was employed for this experimental strain, which was strong toxic strain with negativity in the reduction experiment of nitrate. 35 great gerbils without the infection of Y. pestis were divided randomly and averagely into 7 groups including 6 experimental groups and 1 control group. Great gerbils in the 1st to 6th experimental groups were exposed first with 1 × 106-1 × 1011 CFU/ml of bacterial fluid with 10 times of gradient dilution; groin areas of great gerbils in the control group were injected subcutaneously with physiological saline; and the amount of infection was all 1 ml. 17 great gerbils infected with Y. pestis and the first detection of F1-antibody titer in 1∶256-1∶4 096 were grouped according to F1-antibody titer: group 1∶4 096 (n=4), group 1∶2 048 (n=4), group 1∶1 024 (n=3), group 1∶512 (n=3) and group 1∶256 (n=3); and blood in caudal regions was collected in asepsis for the detection of F1-antibody, with a total of 5 times. 9 great gerbils which were selected from the remaining great gerbils infected with Y. pestis and detected F1-antibody negative 2 times were exposed 1×106 CFU/ml of bacterial fluid for the second infection, with the amount of infection being 1 ml. Blood in caudal regions of great gerbils after the first and second infection were collected for the detection of plague F1-antibody on the 3rd, 5th, 7th, 15th, 30th, 60th, 90th and 120th day after infection. Declined regression models for great gerbils' antibodies were established with unary linear regression equation; declined change diagrams for the antibodies were drawn to observe the declined F1-antibody after great gerbils were exposed to Y. pestis.@*Results@#In great gerbils with the first infection of Y. pestis, antibodies were detected in the 1 × 106-1 × 108 CFU/ml of group on the 30th, 15th and 15th day, respectively; the positive rates of antibody were 1/4, 3/4 and 4/5, respectively; the group 1×107 and 1× 108 CFU/ml reached to the highest antibody titer with 1∶256 on the 120th day; antibodies were revealed in the group 1×109, 1×1010 and 1×1011 CFU/ml from the 5th to 7th day when the seroconversion of all antibodies was observed; group 1×1011 CFU/ml reached to the highest antibody titer on the 120th day with 1∶4 096. In the great gerbils with the second exposure to Y.pestis, positive antibodies were detected on the 3rd day with the positive rate being 2/9; and the highest antibody titer with 1∶2 048 was noted on the 90th day. Unary linear regression equation of declined F1 antibody of great gerbils was y=0.045x- 0.321 (F=115.40, P< 0.001), and the shortest duration for F1-antibody titer declining from 1∶4 096 to 0 was 140 d and the longest duration 200 d.@*Conclusion@#Great gerbils infected with the high concentration of Y. pestis fluid show shorter duration in producing F1-antibody, the antibody positive rate is also higher, and the highest antibody titer can reach 1∶4 096. The great gerbils could hold the plague F1 antibodies for a long time which was about 140 to 200 days from the highest titer.

The complete mitochondrial genome of Meriones libycus (Rodentia: Cricetidae) and its phylogenetic analysis.

Meriones libycus belongs to the genus Meriones in Gerbillinae, its complete mitochondrial genome is 16,341 bp in length. The heavy strand contains 32.8% A, 13.1% G, 25.3% C, 28.8% T, protein-coding genes approximately accounting for 69.54%. Results of phylogenetic analysis showed that M. libycus and Meriones unguiculatus were clustered together, and it was consistent with that of primary morphological taxonomy. This study verifies the evolutionary status of M. libycus in Meriones at the molecular level. The mitochondrial genome would be a significant supplement for the gene pool of Rodentia and the conclusion of phylogenetic analysis could be an important molecular evidence for the classification of Gerbillinae.

The complete mitochondrial genome of Meriones meridianus (Rodentia: Cricetidae) and its phylogenetic analysis.

Meriones meridianus belongs to the genus Meriones in Gerbillinae. Total length of complete mitochondrial genome of M. meridianus is 16,376 bp and the heavy strand contains 32.8% A, 13.1% G, 25.3% C and 28.8% T. Sequences of protein-coding genes are 11,341 bp in length, accounting for 69.25%, approximately. Results of phylogenetic analysis shown that M. meridianus and Meriones unguiculatus were clustered in a single branch. This conclusion would be an important data for relevant studies about the genus Meriones, and mitochondrial genome would be an important supplement for the gene pool of Rodentia. It would play a pivotal role in researches about phylogeography and proteomics involving M. meridianus as well.

Evaluation and establishment of Mongolian gerbil model of long-term infection of Helicobacter pylori with highly-expressed thioredoxin-1 gene / 北京大学学报(医学版)

Objective:To establish a Mongolian gerbils model by long-term infection of Helicobacter py-lori (Hp) with highly-expressed thioredoxin-1 (Trx1 ) gene and to investigate the histopathological findings of gastric mucosa in Mongolian gerbils.Methods:In this study,75 healthy male Mongolian ger-bils were randomly divided into 3 groups:Hp with highly-expressed Trx1 gene group (n =30),Hp with lowly-expressed Trx1 gene group (n =30),and control group (n =15).The animals underwent gastric perfusion of Hp suspension once a week for 5 weeks.The animals were sacrificed at the end of 4,20, 34,48,70,and 90 weeks after inoculation for detecting Hp colonization by rapid urease test and War-thin-Starry silver staining and histological examination,respectively.Results:(1)The Mongolian gerbil model of long-term infection of Hp with highly-expressed Trx1 gene and lowly-expressed Trx1 gene were successfully established.(2)The macroscopic mucosal lesions,including erythema,uneven,erosion, nodules,etc.could be observed in experimental groups.The severity of lesions and the time when lesions occurred in Hp with highly-expressed Trx1 gene group were heavier/earlier than that in Hp with lowly-ex-pressed Trx1 gene group.(3)Histopathologically,the gastric mucosa of Hp with highly-expressed Trx1 gene group showed the mild dysplastic hyperplasia of epithelial cells 34 weeks after the Hp inoculation, and the time was in the 48th week in Hp with lowly-expressed Trx1 gene group.At the end of the 90th week after Hp inoculation,the gastric adenocarcinoma could be detected in the two experimental groups (71.4% vs.42.8%).The difference between the two experimental groups did not reach statistical sig-nificance (P =0.592),which might be due to the small sample capacity and /or short observation time. In addition,there were 2 cases with severe epithelial dysplastic hyperplasia in Hp with highly-expressed Trx1 gene group,and only 3 cases with moderate epithelial dysplastic hyperplasia in Hp with lowly-ex-pressed Trx1 gene group.The uninfected control animals showed no abnormal findings throughout the en-tire observation period.Conclusion:Hp with highly-expressed /lowly-expressed Trx1 gene colonizes stab-ly in the glandular gastric mucosa of Mongolian gerbils.The histological changes after infection are similar to those of the Hp infected human being,and Hp with highly-expressed Trx1 gene cause the injury of gas-tric mucosa and the occurrence of gastric adenocarcinoma.Trx1 maybe the virulence factor that partici-pates in the pathogenesis of gastric cancer and Hp expressing high levels of Trx1 should be highly toxic for gastric diseases in China.

Effects of Helicobacter pylori on the expression of catalytic subunit of the DNA-dependent protein kinase and Ku70/Ku80 heterodimer in gastric mucosa epithelial cells in vivo and in vitro / 中华消化杂志

Objective To explore the effects of Helicobacter pylori (H.pylori) on the expression of catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs) and Ku70/Ku80 heterodimer in gastric mucosa epithelial cells in vivo and in vitro.Methods After treated with H.pylori for one,three,six,12 and 24 hours,the expressions of DNA-PKcs and Ku70/Ku80 heterodimer in gastric epithelial cells (GES) 1 and gastric adenocarinoma cells (AGS) were detected by Western blot.Mongolian gerbils were gavaged with H.pylori,and were sacrificed after infected for six and 12 months.The gastric mucosa tissues were taken for immunohistochemistry to detect the expressions of DNA-PKcs and Ku70/Ku80 heterodimer at protein level.The data were analyzed by t test and chi-square test.Results After H.pylori infection for one hour,the relative quantity of the expression of DNA-PKcs in GES-1 was 1.16±0.09,which was higher than that of non infected group (1.04±0.31) and the difference was statistically significant (t=4.67,P＜0.05).After infected by H.pylori for one,three,six,12 and 24 hours,the relative quantities of the expressions of Ku70/Ku80 heterodimer in GES-1 were 1.58±0.32,1.84±0.40,1.97±0.35,3.72±1.42 and 3.74±1.56,respectively,all were higher than that of non infected group (1.24±0.31) and the differences were statistically significant (t=3.57,4.20,5.03,8.11 and 8.14,all P＜0.05).The relative quantities of the expressions of Ku70/Ku80 heterodimer in AGS were 4.69 ± 0.87,3.67 ± 0.67,2.41±0.24,1.35±0.35 and 1.32±0.10 after H.pylori infected for one,three,six,12 and 24 hours,respectively,all were lower than that of no H.pylori infected group (4.84 ± 0.76) and the differences were statistically significant (t=34.13,27.68,19.81,4.47 and 5.69,all P＜0.05).In Mongolian gerbil models,DNA-PKcs did not express in H.pylori negative group (0/25),the total positive rate of H.pylori infected group was 98.1％ (53/54),the difference between the two groups was statistically significant (x2 =74.55,P＜0.01).The total positive rate of Ku70/Ku80 heterodimer in H.pylori negative group was 92.0％ (23/25) and in H.pylori infected group was 68.5％ (37/54),the difference between the two groups was statistically significant (x2=5.16,P＜0.05).Conclusion H.pylori infection affected cellular DNA damage repair through changing the expression of DNA-PKcs and Ku70/Ku80 heterodimer in gastric mucosa in vivo and in vitro,which may cause gastric mucosal lesions.

Monitoring results and epidemic analysis of gerbil plague in northern Ningxia in 2009 / 中国地方病学杂志

Objective To analyze gerbil plague in northern Ningxia and the monitoring results,to master the plague epidemic dynamics,and to provide the basis for developmenting countermeasures.Methods Monitoring data of gerbil plague focus in northern Ningxia were collect in 2009,counted main host density,rate of dye fleas,flea body index and bacteriology,serology detect and analyzed the epidemic situation.Results An average density of main host was 1.74/hm2,the average rate of infected fleas was 28.60％,and the average rat body flea index was 0.76.Monitoring found 4 plagues from rat plague epidemic,plague bacteria were found in 16 strains,of which gerbils inspection bacteria 10 strains,Meriones unguiculatus 2 strains,the same type cheopis 2 strains,and bald disease fleas 2 strains.Indirect hemagglutination (IHA) was used to test 529 copies of samples,2 copies were found positive,and hemagglutination-positive rate was 0.38％; eight copies were examined by reverse indirect hemagglutination(RIHA),7 material were found positive,and hemagglutination-positive rate was 87.50％.Conclusions In recent years,the disease is active among animals in gerbil plague focus Ningxia.The density of rodents is higher,and local plague epidemic is found in rats.Monitoring efforts should be strengthened and scope of monitoring should be expanded.We should pay close attention to the epidemic dynamics,control the prevalence and spread of animal disease,and prevent the occurrence of human plague.

Preconditioning with L-alanyl-L-glutamine in a Mongolian Gerbil model of acute cerebral ischemia/reperfusion injury / Pré-condicionamento com L-alanil-L-glutamina em modelo de isquemia/reperfusão cerebral aguda em Gerbils da Mongólia

PURPOSE: To investigate the effect of L-alanyl-L-glutamine (L-Ala-Gln) preconditioning in an acute cerebral ischemia/reperfusion (I/R) model in gerbils. METHODS: Thirty-six Mongolian gerbils (Meriones unguiculatus), (60-100g), were randomized in 2 groups (n=18) and preconditioned with saline 2.0 ml (Group-S) or 0.75g/Kg of L-Ala-Gln, (Group-G) administered into the femoral vein 30 minutes prior to I/R. Each group was divided into three subgroups (n=6). Anesthetized animals (urethane, 1.5g/Kg, i.p.) were submitted to bilateral occlusion of common carotid arteries during 15 minutes. Samples (brain tissue and arterial blood) were collected at the end of ischemia (T0) and after 30 (T30) and 60 minutes (T60) for glucose, lactate, myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), glutathione (GSH) assays and histopathological evaluation. RESULTS: Glucose and lactate levels were not different in studied groups. However glycemia increased significantly in saline groups at the end of the reperfusion period. TBARS levels were significantly different, comparing treated (Group-G) and control group after 30 minutes of reperfusion (p<0.05) in cerebral tissue. Pretreatment with L-Ala-Gln promoted a significant increase in cerebral GSH contents in Group-G at T30 (p<0.001) time-point compared with Group-S. At T30 and T60, increased levels of GSH occurred in both time-points. There were no group differences regarding MPO levels. Pyknosis, presence of red neurons and intracellular edema were significantly smaller in Group-G. CONCLUSION: Preconditioning with L-Ala-Gln in gerbils submitted to cerebral ischemia/reperfusion reduces oxidative stress and degeneration of the nucleus (pyknosis) and cell death (red neurons) in the cerebral tissue.

OBJETIVO: Investigar o efeito do pré-condicionamento com L-alanil-L-glutamina (L-Ala-Gln) em gerbils submetidos à isquemia/reperfusão (I/R) cerebral aguda. MÉTODOS: Trinta e seis gerbils (Meriones unguiculatus) (60-100g) foram divididos em dois grupos (n=18) e pré-condicionados com 2,0 ml de soro fisiológico (Grupo-S) ou 0.75g/kg de L-Ala-Gln, (Grupo-G), administrados na veia femoral 30 minutos antes da I / R. Cada grupo foi dividido em três subgrupos (n=6).Animais anestesiados com uretano, 1.5g/kg, ip, foram submetidos à oclusão bilateral das artérias carótidas comuns, durante 15 minutos. Amostras (tecido cerebral e sangue arterial) foram coletadas no final da isquemia (T0) e após 30 (T30) e 60 minutos (T60) para a aferição das concentrações de glicose, lactato, mieloperoxidase (MPO), substâncias reagentes ao ácido tiobarbitúrico (TBARS), glutationa (GSH) e avaliação histopatológica. RESULTADOS: As concentrações de glicose e lactato não foram diferentes nos grupos estudados; a glicemia aumentou significativamente no Grupo-S ao final da reperfusão. Concentrações de TBARS no tecido cerebral foram significativamente diferentes, comparando os Grupos G e S, no T30 (p <0,05). O pré-tratamento com L-Ala-Gln promoveu um aumento significativo de GSH cerebral no Grupo-G comparado ao Grupo-S no T30 (p <0,001). Houve aumento das concentrações de GSH no T30 e T60 no Grupo-G. Não houve diferenças quanto as concentrações de MPO. Picnose, presença de neurônios vermelhos e edema intracelular foram significativamente menores no Grupo-G. CONCLUSÃO: O pré-condicionamento com L-Ala-Gln em gerbils submetidos à isquemia/reperfusão cerebral reduz o estresse oxidativo, a degeneração nuclear (picnose) e morte celular (neurônios vermelhos) no tecido cerebral.

Meriones libycus is the main reservoir of zoonotic cutaneous leishmaniasis in south Islamic Republic of Iran

A study was made in rural regions around Neiriz city, Fars province in the south of the Islamic Republic of Iran during 2002-03 to further investigate a new focus of zoonotic cutaneous leishmaniasis. Meriones libycus was the dominant rodent [100% of 65 rodents collected] and 4.6% were naturally infected with the amastigote form of Leishmania spp. Promasigotes were identified as L. major. This confirms M. libycus as the main reservoir host of zoonotic cutaneous leishmaniasis in southern parts of the country

Characterization of Leishmania infection in rodents from endemic areas of the Islamic Republic of Iran

Between 1991-2000, Leishmania species were isolated and characterized by isoenzyme and molecular analysis from rodents caught in various parts of the Islamic Republic of Iran. In areas endemic for cutaneous leishmaniasis, parasites were observed by direct microscopy in smears from 18.6% of 566 specimens. L. major was isolated from 4 species: Rhombomys opimus, Meriones libycus, Tatera indica and Mer. hurrianae. L. turanica was isolated from R. opimus for the first time in this country. In endemic areas of visceral leishmaniasis, parasites were observed in liver and spleen from 13.7% of 504 rodents. Two species were positive on culture; promastigotes isolated from Mer. persicus were characterized as L. donovani zymodeme LON50 and from Mesocricetus auratus as L. infantum LON49

Long-term administration of vitamin A and the process of spermatogenesis

The effect of retinoids on spermatogenesis in adult male gerbils [Gerbillus cheesemani] was studied using light and electron microscopy. Treatment with either 13-cis-retinoic acid or retinol acetate was given for 6 weeks and their effects were compared with controls. It was found that 13-cis-retinoic acid induced almost complete cessation of spermatogenesis and produced alterations in the cytoplasm of Leydig cells. No differences were seen in the testis of animals treated with retinol acetate compared with controls using light microscopy but it appeared to produce noticeable ultrastructural changes in Leydig cells. The changes observed were reversed 12 weeks after stopping treatment. Caution should be exercised regarding the use of dietary retinoids in the prevention of cancer

The effect of high concentration oxygen to the lipid peroxidation of the gerbils subjected to cerebral ischemia and reperfusion / 中国病理生理杂志

Exposure of gerbils 120 min to a high concentration oxygen (HCO)atmosphere after 60 min cerebral ischemia resulted in a marked increase in cerebral malondialdehyde (MDA, 4.39?0.26 nmol/mg protein). Much less cerebral MDA was among the other groups (2.63?0.50 nmol/mg protein in sham-operated controls; 3.07?0.52 nmol/mg protein in gerbils exposed to HCO without ischemia; 2.96?0.41nmol/mg protein in ger. bils subjected to 60 min ischemia; 2.79?0.59nmol/mg protein in gerbils subjected to 60 min ischemia and 120 min reperfusion). The contents of cerebral water, sodium, increassd after 60 mln cerebral ischemia. The contents of TXB_2 increased, 6-Keto-PGF_(1?) decreased, the elevation of cerebral water and sodium were more obvious after 120 min repefusion following ischemia. There was no difference in these items except for MDA between the reperfusion groups within air and within HCO.The authors proposed the mechanism that HCO elevates the contents of cerebral MDH might be due to abnormal function of election transport chain of mitochondria.