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A BOLD-fMRI study of cerebra activation induced by injection of algesic chemical substances into the anesthetized rat forepaw
2008
Asanuma, T.(Hokkaido Univ., Sapporo (Japan)) | Yasui, H. | Sato, M. | Inanami, O. | Kuwabara, M.
This study was performed to examine whether the brain activities induced by noxious algesic chemical substances in anesthetized animals could be detected by blood oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI). Multislice gradient echo images of the primary somatosensory cortex were obtained using a 7.05 T superconducting system and a one-turned surface coil centered over the primary somatosensory cortex of the 1.0%-isoflurane-anesthetized rat. The Z-score t-map of BOLD signals and its time-course analysis revealed that subcutaneous injection of formalin into the left forepaw immediately induced an early response in the contralateral primary sensory cortex lasting for a few minutes, followed by a late response until 20 min after stimulation. In contrast, injection of capsaicin into the left forepaw evoked only the early response. Furthermore, pretreatment with morphine completely abolished these responses induced by the chemical algesic substances. Thus BOLD-fMRI is a useful method to analyze the brain activities of painful stimulation in anesthetized animals.
Show more [+] Less [-]Downregulation of male-specific cytochrome P450 by profenofos
2008
Moustafa, G.G.(Hokkaido Univ., Sapporo (Japan)) | Ibrahim, Z.S. | Ahmed, M.M. | Ghoneim, M.H. | Sakamoto, K.Q. | Ishizuka, M. | Fujita, S.
The health hazards of individual organophosphorus insecticides have been characterized by their acute toxicity, mainly by investigating their cholinesterase inhibition. However, the chronic effects of most of these toxicants on the drug-metabolizing enzymes have not been investigated. Profenofos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) is an organophosphorus pesticide widely used in cotton cultivation. In the present study, we investigated the effect of profenofos on male-specific cytochrome P450 (CYP) enzymes in adult Wistar rats. We orally administered 17.8 mg/kg body weight, twice weekly for 65 days. Profenofos downregulated levels of hepatic and testicular CYP2C11 and CYP3A2 mRNA and protein expression. Testicular aromatase (CYP19A) mRNA was decreased in the profenofos-treated rats compared to controls. Overall, the present study suggests that profenofos acts as an endocrine disruptor of male-specific CYP enzymes and affects testosterone concentration, which implicates its deleterious effects on animal or human males chronically exposed to organophosphorus pesticide.
Show more [+] Less [-]Protection by Nigella sativa against carbon tetrachloride-induced downregulation of hepatic cytochrome p450 isozymes in rats
2008
Ibrahim, Z.S.(Hokkaido Univ., Sapporo (Japan)) | Ishizuka, M. | Soliman, M. | ElBohi, K. | Sobhy, W. | Muzandu, K. | Elkattawy, A.M. | Sakamoto, K.Q. | Fujita, S.
Nigella sativa (family Ranunculaceae ) is an annual plant that has been traditionally used on the Indian subcontinent and in Middle Eastern countries. In this study, we investigated the effect of N. sativa oil on the drug-metabolizing cytochrome P450 (CYP) enzymes and whether it has a protective effect against the acute hepatotoxicity of CCl4. Intraperitoneal injection of rats with CCl4 drastically decreased CYP2E1, CYP2B, CYP3A2, CYP2C11, and CYP1A2 mRNA and protein expressions. Oral administration of 1 ml/kg N. sativa oil every day for one week prior to CCl4 injection alleviated CCl4-induced suppression of CYP2B, CYP3A2, CYP2C11, and CYP1A2. Moreover, CCl4 increased iNOS and TNFalpha mRNA, while N. sativa oil administration for one week prior to CCl4 injection downregulated the CCl4-induced iNOS mRNA and up-regulated IL-10 mRNA. These results indicate that N. sativa oil administration has a protective effect against the CCl4-mediated suppression of hepatic CYPs and that this protective effect is partly due to the downregulation of NO production and up-regulation of the anti-inflamnatory IL-10.
Show more [+] Less [-]Genetic and antigenic analyses of a Puumala virus isolate as a potential vaccine strain
2008
Daud, N.H.A.(Hokkaido Univ., Sapporo (Japan)) | Kariwa, H. | Tkachenko, E. | Dzagurnova. T. | Medvedkina, O. | Tkachenko, P. | Ishizuka, M. | Seto, T. | Miyashita, D. | Sanada, T. | Nakauchi, M. | Yoshii, K. | Maeda, A. | Yoshimatsu, K. | Arikawa, J. | Takashima, I.
Puumala virus (PUUV), a causative agent of hemorrhagic fever with renal syndrome (HFRS), is prevalent in Europe and European Russia. No vaccine has been developed for PUUV-associated HFRS, primarily because of the low viral yield in cultured cells. A PUUV strain known as DTK/Ufa-97 was isolated in Russia and adapted for growth in Vero E6 cells maintained in serum-free medium. The DTK/Ufa-97 strain produced a higher viral titer in serum-free medium, suggesting that it may prove useful in the development of an HFRS vaccine. When PUUV-infected Vero E6 cells were grown in serum-free medium, the DTK/Ufa-97 strain yielded more copies of intracellular viral RNA and a higher viral titer in the culture fluid than did the Sotkamo strain. Phylogenetic analysis revealed that PUUVs can be classified into multiple lineages according to geographical origin, and that the DTK/Ufa-97 strain is a member of the Bashkiria-Saratov lineage. The deduced amino acid sequences of the small, medium, and large segments of the DTK/Ufa-97 strain were 99.2% to 100%, 99.3% to 99.8%, and 99.8% identical, respectively, to those of the Bashkirian PUUV strains and 96.9%, 92.6%, and 97.4% identical, respectively, to those of the Sotkamo strain, indicating that the PUUVs are genetically diverse. However, DTK/Ufa-97 and other strains of PUUV exhibited similar patterns of binding to a panel of monoclonal antibodies against Hantaan virus. In addition, diluted antisera (i.e., ranging from 1:160 to 1:640) specific to three strains of PUUV neutralized both homologous and heterologous viruses. These results suggest that the DTK/Ufa-97 strain is capable of extensive growth and is antigenically similar to genetically distant strains of PUUV.
Show more [+] Less [-]Polymorphism in MRL and AKR mice Sry: A candidate gene for the appearance of testicular oocyte
2008
Otsuka, S.(Hokkaido Univ., Sapporo (Japan)) | Konno, A. | Hashimoto, Y. | Sasaki, N. | Endoh, D. | Kon, Y.
Although mammals produce either sperm or eggs depending on their sex, newborn MRL/MpJ male mice contain oocytes within their testes. In our previous study, the testicular oocyte appears as early as day 0 afterbirth and has morphological characteristics as an oocyte such as zona pellucida and follicular epithelial cells. Based on the observation of F1 between MRL/MpJ and C57BL/6, one of the genes causing the appearance of testicular oocyte exists on the Y chromosome. In the present study, we found testicular oocytes within newborn AKR mice. We have also analyzed the Sry genes from several inbred mouse strains and identified a shortened glutamine repeat near the C-terminal region that is unique to MRL and AKR. These results suggest that polymorphism of glutamine repeat within SRY correlates with the appearance of testicular oocyte and this phenotype is derived from AKR, one of the original strains of MRL mice.
Show more [+] Less [-]Immunohistochemical localization of the estrogen receptor alpha (ERalpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) during pregnancy
2008
Yanagawa, Y.(Hokkaido Univ., Sapporo (Japan)) | Matsuura, Y. | Suzuki, M. | Katagiri, S. | Tsubota, T.
Information on steroid hormone receptor distribution in the uterus is essential to understand the roles of their ligands in pregnancy. This study examined the spatio-temporal localization of estrogen receptor alpha (ERalpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) to determine the estrogen and progesterone action site during pregnancy. Ovaries and uteri were collected from 21 pregnant sika deer with single fetus and two corpora lutea, ranging from Day 20 to Day 207 of pregnancy. In addition, genital organs were also collected from three sika deer whose gestational status was unknown: one female had only one developing corpus luteum: =Day 4 (metestrus) and two females had two corpora lutea, one of which was at the developing stage equivalent to diestrus or early pregnancy: Day 7 (diestrus). Staining of ERalpha and PR was clear in all cell types during metestrus. During diestrus, the presence of ERalpha was also clear in deep glandular epithelium, stroma and myometrium, whereas it was suppressed in luminal epithelium and shallow glandular epithelium. Staining of PR was suppressed in luminal epithelium but was detectable in other cell types. Staining of ERalpha in all cell types and PR in luminal epithelium and glandular epithelium became undetectable by Day 28. PR was presented in stroma and myometrium throughout pregnancy. The distribution pattern of ERalpha and PR was different during diestrus from that in a ruminant. This could be attributed to estrogen secretion from the maturing and ovulating follicles in the presence of developed corpus luteum.
Show more [+] Less [-]Roles of the hypocretin/orexins in the regulation of sleep and wakefulness
2008
Terao, A.(Hokkaido Univ., Sapporo (Japan)) | Haruyama, T. | Kimura, K.
Hypocretin/orexin is produced exclusively in the dorsal and lateral hypothalamus but its projection is widespread within the brain and plays important roles. In this paper, we review the independent discoveries of the hypocretin/orexin peptides, the neuroanatomy of this system, and the link to the sleep disorder narcolepsy that has led to the idea that this system plays a crucial role in the regulation of sleep and wakefulness.
Show more [+] Less [-]Establishment of a laboratory colony of taiga tick Ixodes persulcatus for tick-borne pathogen transmission studies
2008
Konnai, S.(Hokkaido Univ., Sapporo (Japan)) | Saito, Y. | Nishikado, H. | Yamada, S. | Imamura, S. | Mori, A. | Ito, T. | Onuma, M. | Ohashi, K.
Ixodes persulcatus Schulze (I. persulcatus) is distributed in Russia and Far East Asia including Japan, and has been implicated as the vector of several human pathogens. In particular, I. persulcatus acts as the only tick vector for human lyme borreliosis in Japan. In order to elucidate the mechanism of transmission of I. persulcatus-borne pathogens, we developed a laboratory colony of I. persulcatus. Ticks were fed on Syrian hamster and engorged ticks that had dropped off the animals were collected and maintained to allow them to molt. Tick rearing was performed in incubator at 20degC with 95% relative humidity and 12-hour light/dark photo-period regimen. We found out that adult females fed for 8+-2 days and had a pre-oviposition period lasting for 7+-2 days. The minimum egg incubation period was 1 month with the hatched larvae feeding for 3+-1 days and molting to nymphs 3-4 months thereafter. Meanwhile, the nymphs fed for 4+-1 days and molted to adult 2-3 months thereafter. For future analysis of gene expression profiles in I. persulcatus, we cloned and sequenced the actin gene (a housekeeping gene), and found that it is 92.7% to 98.6% homologous to the published sequences of related ixodid ticks. This laboratory colony of I. persulcatus will facilitate investigations on the role of tick-derived molecules on the transmission of I. persulcatus-borne pathogens and will be important for identification of potential anti-tick vaccine and acaricide target molecules.
Show more [+] Less [-]Expression of alpha-hemoglobin stabilizing protein and cellular prion protein in a subclone of murine erythroleukemia cell line MEL
2008
Otsuka, Y.(Hokkaido Univ., Sapporo (Japan)) | Ito, D. | Katsuoka, K. | Arashiki, N. | Komatsu, T. | Inaba, M.
alpha-Hemoglobin stabilizing protein (AHSP) functions as the erythroid-specific molecular chaperon for alpha-globin. AHSP gene expression has been reported to be downregulated in hematopoietic tissues of animals suffering from prion diseases though the mechanism remains to be clarified. Herein, we demonstrate that MELhipod8 cells, a subclone of murine erythroleukemia (MEL) cells, have prion protein (PrPsup(C)) on the cell surface and have highly inducible expression of the AHSP and alpha- and beta-globin genes, resembling the expression pattern of the PrP and AHSP genes in bipotential erythroid- and megakaryocyte-lineage cells followed by erythroid differentiation in normal erythropoiesis. Moreover, MELhipod8 cells exhibit greater effective erythroid differentiation with a population of hemoglobinized normoblast-like cells than that observed for the parental MEL cells. These findings suggest that MELhipod8 cells could provide a mechanism for downregulation of the AHSP gene in prion diseases.
Show more [+] Less [-]Comparative study of the citrus pulp to cause acute rumen lactic acidosis in cattle | Avaliação do potencial da polpa cítrica em provocar acidose láctica ruminal aguda em bovinos Full text
2008
Raimundo Alves Barrêto Júnior | Antonio Humberto Hamad Minervino | Frederico A. Mazzocca Lopes Rodrigues | Alexandre Coutinho Antonelli | Maria Claudia Araripe Sucupira | Clara Satsuki Mmori | Enrico Lippi Ortolani
With the aim to evaluate the risk of citrus pulp to induce acute rumen lactic acidosis (ARLA), 15 rumen cannulated cattle didn't adapted to concentrates were randomly allocated in 3 groups: G1- CONTROL - group fed only the basal diet; G2 - SUCROSE animals with ARLA induced by rumen administration of sucrose; G3 CITRUS PULP animals received citrus pulp into rumen (1.65% of BW). Blood and rumen samples were drawn throughout the next 24 h to determine pH, lactic acid concentration and the packet cell volume, blood base excess. Clinical signs were also recorded and food intake followed by the next 7 days. Sucrose caused a systemic and ruminal acidosis and characteristic ARLA signs such as, apathy, dehydration, diarrhea and tachycardia, while citrus pulp gave rise to mild and brief rumen acidosis, reaching the lowest pH (5.35) at the 6th h, without any changing in the blood pH and any typical clinical sign, but temporary reduction in the rumination and excretion of semi liquid feces. Appetite was fully recovered after two and seven days in the pulp and sucrose group, respectively. These results showed that citrus pulp may be used as a feedstuff for cattle with low risk to cause ARLA. | Com o objetivo de avaliar o potencial da polpa cítrica (PC) em provocar acidose láctica ruminal aguda (ALRA), 15 bovinos com peso médio de 160 kg providos de cânula ruminal não-adaptados à dieta contendo concentrado foram alocados aleatoriamente em três grupos: CONTROLE animais receberam apenas a dieta basal; SACAROSE animais receberam sacarose diretamente no rumem a fim de provocar ALRA; POLPA - grupo que recebeu subitamente alta quantidade de PC no rúmen (equivalente a 1,65% do peso corporal). Em vários tempos no decorrer de 24 horas, após administração dos substratos, foram determinados o volume globular, pH, excesso de bases (BE) e lactato total no sangue e pH e concentração de ácido láctico total no conteúdo ruminal. Exame clínico foi realizado no decorrer do 1º dia e o consumo de alimento acompanhado nos próximos sete dias. A administração de sacarose provocou um característico quadro de ALRA com o desenvolvimento de acidose ruminal e sistêmica, apatia, desidratação, diarréia e taquicardia. Por outro lado, a polpa cítrica produziu discreta e temporária acidose ruminal, atingindo na 6ª hora o pH ruminal mais baixo (5,35), sem provocar acidose sistêmica e quadro clínico mais evidente de ALRA, com exceção de uma diminuição temporária na ruminação e eliminação de fezes semilíquidas. A regularização do apetite ocorreu após dois dias no grupo com PC e sete dias no grupo com sacarose. Tais resultados indicam que a polpa cítrica pode ser utilizada na alimentação de bovinos com baixo risco de provocar ALRA.
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