Biomedical subjects

T Itou

Publications and source records attributed to T Itou.

At least 19 recordsLinked to original sources

PubMed2006

Molecular epidemiology of rabies from Maranhão and surrounding states in the northeastern region of Brazil.

Although many outbreaks of rabies have been reported in northern Brazil, few epidemiological studies of these outbreaks have been undertaken. In this study, molecular epidemiological analyses were performed using 41 rabies virus samples isolated in the Maranhão (MA), Pará (PA), and Tocantins (TO) states of northeastern Brazil. A 599-bp region of the glycoprotein (G) gene was first amplified from each sample by RT-PCR, then sequenced and subjected to phylogenetic analysis. A phylogenetic tree divided the 41 isolates into two clades: Clade I was associated with terrestrial carnivores and Clade II was associated with vampire bats. The Clade I isolates were further sub-divided into two groups. The first group was closer to carnivore isolates that predominate in central Brazil, whereas the second group more closely resembled wild fox isolates from the northeastern coastal state of Paraíba (PB). MA isolates of Clade II formed an entirely separate group. These results demonstrate that bat- and dog-transmitted rabies occur in northwestern Brazil.

Animals↗

PubMed2006

Genetic and phylogenetic characterization of rabies virus isolates from wildlife and livestock in Paraiba, Brazil.

Thirty-four rabies virus (RV) isolates from foxes (8), insectivore bats (9), cattle (14), sheep (1), a goat (1) and a donkey (1) from Paraiba state, northeastern Brazil, were genetically characterized. Sequences of 890 nts of nucleoprotein (N) genes of these isolates were analyzed and compared with those of other Brazilian isolates characterized earlier. Phylogenetic analysis revealed three genetical lineages of RV co-existing in this region. Each lineage was found to be associated with particular host species and to circulate independently of each other. The first lineage was found in foxes (Dusicyon sp.) and could be discriminated from domestic carnivore isolates from Sao Paulo, Goias and Minas Gerais in the southern and central Brazil. The second lineage was associated with insectivorous bats (Molossus spp.) and differed from vampire bat-associated RV isolates. The third lineage was found in livestock and clustered with vampire bat-associated RV isolates from Sao Paulo, Tocantins, Goias and Matto Grosso. These results indicate that RV of these genetic lineages are cocirculating in the Paraiba state and that livestock in this region are infected with vampire bat-associated RV, suggesting that the vampire bat is the main reservoir of livestock rabies in this region.

Animals↗

PubMed2004

Collapse of charge order in a quasi-one-dimensional organic conductor with a quarter-filled band.

A charge-ordered insulator, (DI-DCNQI)2Ag, with a quasi-one-dimensional quarter-filled band is metallized by pressure. It was found that the charge order melts into a curious metallic state with cubic-temperature dependence of the resistivity, which implies the unprecedented mechanism of the electron-electron scattering. We constructed the pressure-temperature phase diagram, where the melting line has a tricritical point dividing the second-order line at low pressures and the first-order line at high pressures just before it vanishes.

Journal Article↗

PubMed2004

Magnetic-field-induced Mott transition in a quasi-two-dimensional organic conductor.

We investigated the effect of magnetic field on the highly correlated metal near the Mott transition in the quasi-two-dimensional layered organic conductor, kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl, by the resistance measurements under control of temperature, pressure, and magnetic field. It was demonstrated that the marginal metallic phase near the Mott transition is susceptible to the field-induced localization transition of the first order, as was predicted theoretically. The thermodynamic consideration of the present results gives a conceptual pressure-field phase diagram of the Mott transition at low temperatures.

Journal Article↗

PubMed2003

A PPAR agonist improves TNF-alpha-induced insulin resistance of adipose tissue in mice.

Thiazolidinediones (TZDs), agonists for PPARs, have been shown to block the inhibitory effects of TNF-alpha on insulin action using cultured cells. In order to clarify the in vivo effects of TZDs on the inhibition of insulin sensitivity by TNF-alpha, insulin action in muscles and adipose tissues was assessed in the TNF-alpha-overexpression mice model using transplantation of cells secreting the TNF-alpha protein. After the pioglitazone treatment for 4 weeks, glucose uptake, insulin-induced IRS-1 phosphorylation, and lipoprotein lipase mRNA levels were analyzed. Pioglitazone did not ameliorate TNF-alpha-induced hyperinsulinemia in this model, as assessed by the OGTT. Glucose uptake and lipoprotein lipase mRNA levels were decreased by TNF-alpha in adipose tissues from the TNF-alpha-overexpressing mice, and pioglitazone blocked these inhibitions by TNF-alpha. On the other hand, in muscles, pioglitazone did not reverse the effects of TNF-alpha on insulin-induced phosphorylation of IRS-1, glucose uptake, and lipoprotein lipase mRNA levels. Present study revealed the different sensitivities of pioglitazone for the recovery of decreased insulin action in a TNF-alpha-overexpressing model using cell transplantation. These results suggest that the effect of TZDs is dependent on the fat distribution and accumulation in humans.

Adipose Tissue↗

PubMed2003

A low-molecular-weight fraction of bovine colostrum and milk enhances the oxidative burst activity of polymorphonuclear leukocytes.

Bovine colostrum and milk contain many immunomodulatory components. The low-molecular-weight fraction (< 10 kDa) was separated from colostrum and milk by gel filtration chromatography, and its effect on the oxidative burst of bovine polymorphonuclear leukocytes (PMNL) was investigated in vitro. The oxidative burst activity induced by Staphylococcus aureus was considerably enhanced when PMNLs were incubated with this low-molecular-weight fraction. However, phorbol 12-myristate 13-acetate did not trigger a burst after priming with this fraction. The oxidative burst activity enhanced by this fraction was reduced after heating. These results confirmed that a low-molecular-weight substance(s) of less than 10 kDa, present in bovine milk and colostrum, enhances the oxidative burst activity of PMNL.

Animals↗

PubMed2002

d Orbital doping into pi charge-ordered molecular insulator.

A quasi-one-dimensional pi-electron charge-ordered insulator, (DI-DCNQI)2Ag, is metallized by Cu doping into the Ag sites. It is found that with doping the charge gap is diminished and then disorder-induced insulating nature comes up, eventually followed by transition or crossover to a pi-d networked metal. The profile of the charge-gap collapse is consistent with the prediction of the theory highlighting the interplay between electron correlation and disorder. The present doping method is regarded as doping of d orbital, which is different from the conventional charge and/or spin doping developed in cuprates and manganites.

Journal Article↗

PubMed2002

Changes in the prevalence of rotavirus G and P types in diarrheic calves from the Kagoshima prefecture in Japan.

G8 bovine group A rotavirus was the most predominant serotype in calf diarrheal fecal specimens examined between 1995 and 1996 in Japan [Vet. Microbiol. 66 (1999) 301]. To date, no evidence that G8 was the most predominant in the typeable specimens has been observed outside Japan. To investigate whether G8 continues to be as common as G6 and G10, the incidence of the main serotypes was determined in the same area (Kagoshima prefecture) between 1997 and 1998 by reverse transcription-polymerase chain reaction. From a total of 104 rotavirus-positive specimens, we successfully identified G type in 79 (76.0%) and P type in 71 (68.3%). The combination of G and P types varied periodically; in 1995, G10P[11] was most common. The most predominant types changed drastically in 1996, and G8 and mixed P types were the most predominant. A dramatic shift of the most predominant type occurred again in 1997 when G6P[5] was most common. This frequency of G6P[5] also continued in 1998. These results suggest that the serotypes prevailing in certain areas change periodically.

Animals↗

PubMed2002

Alterations of insulin sensitivity by the implantation of 3T3-L1 cells in nude mice. A role for TNF-alpha?

AIMS/HYPOTHESIS: Visceral adipocytes have different functions than those from the subcutaneous fat area. These differences could contribute to the pathological significance of excessive visceral fat accumulation for accompanying insulin resistance and hyperinsulinaemia. This study addresses this hypothesis and describes a unique method to clarify whether the functional differences between visceral and subcutaneous adipocytes depend on their anatomical location. METHODS: 3T3-L1 cells or TNF-alpha overexpressing CHO cells were implanted into subcutaneous fat area or mesenteric area as visceral fat area in athymic mice of BALB/C strain. Then, serum insulin, glucose, TNF-alpha, and several markers of lipid metabolism were measured in the fasting condition. OGTT was also analysed. RESULTS: During the course of glucose loading, the mice which had 3T3-L1 cells implanted into mesenteric area but not into subcutaneous fat area showed remarkably increased serum insulin and TMF-alpha concentrations, compared to the control mice. Moreover, serum insulin concentrations of the mice, implanted with TNF-alpha overexpressing cells into subcutaneous fat area, were apparently higher than that of control mice. CONCLUSION/INTERPRETATION: This method of implanting adipose cells into subcutaneous or visceral fat area showed high TNF-alpha concentration and insulin resistance by the adipose cells in visceral area of nude mice. Furthermore, we found that the functional significance of visceral fat accumulation for TNF-alpha-induced insulin resistance is partly caused by the interaction of adipocytes with surrounding conditions in mesenteric area.

3T3 Cells↗

PubMed2001

Genetic characterization and geographic distribution of rabies virus isolates in Brazil: identification of two reservoirs, dogs and vampire bats.

We analyzed 50 rabies virus samples isolated in Brazil from 12 dogs, 11 cats, 5 vampire bats, 15 cattle, 2 horses, 1 pig, 1 sheep, and 3 humans to investigate the molecular epidemiology of rabies viruses. We sequenced 203 nucleotides on the nucleoprotein gene by direct sequencing of the PCR-amplified products. All the isolates belonged to the genotype 1 and homology of the 203 nucleotides was at least 83.7% among isolates. The main reservoirs were estimated based on the homology of nucleotide sequences. Brazilian rabies virus isolates were clustered into two reservoir groups: dogs and vampire bats. All the dog-related rabies virus isolates showed nucleotide homology greater than 99.0%. Vampire bat-related rabies virus isolates showed nucleotide homology greater than 96.6% and could be further divided into subgroups corresponding to areas where viruses were isolated. These data suggest that circulating rabies variants belong to at least two different genotype clusters in Brazil and that these two clusters are maintained independently among vampire bats and dogs.

Amino Acid Sequence↗

PubMed2001

Molecular cloning and functional expression of bottle-nosed dolphin (Tursiops truncatus) interleukin-1 receptor antagonist.

The bottle-nosed dolphin (Tursiops truncatus) interleukin-1 receptor antagonist IL-1ra cDNA was cloned from mitogen-stimulated peripheral blood mononuclear cells (PBMC) RNA utilizing the reverse transcription-polymerase chain reaction (RT-PCR). The sequence of this cDNA showed that dolphin IL-1ra clones contained open reading frames encoding 177 amino acids. Comparison of the deduced amino acids showed that dolphin IL-1ra sequence shared 87.6, 77.9, 77.4, 77.4, 76.4, and 75.8% similarity with the bovine, rabbit, equine, human, mouse, and rat IL-1ra sequences, respectively. Recombinant glutathione S-transferase (GST) dolphin IL-1ra produced in Escherichia coli (E. coli) was purified. This protein suppressed the cytostatic activity of dolphin IL-1beta on A375S2 cells, indicating that the dolphin IL-1ra cDNA obtained in the present study encodes biologically active dolphin IL-1ra.

Amino Acid Sequence↗

PubMed2001

Molecular cloning and identification of bottle-nosed dolphin p40(phox), p47(phox) and p67(phox).

The bottle-nosed dolphin NADPH oxidase cytosolic components, p40(phox), p47(phox) and p67(phox) cDNA's were cloned from mitogen stimulated peripheral white blood cell mRNA utilizing the reverse transcription-polymerase chain reaction. The sequences of these cDNAs showed that dolphin p40(phox), p47(phox) and p67(phox) clones contained open reading frames encoding predicted polypeptides of 339, 391 and 526 amino acids, respectively. Analysis of the p47(phox) and p67(phox) amino acid sequences showed two potential Src homology three domains and p40(phox) one. Comparison of the deduced amino acids showed that dolphin p40(phox) sequence shared 88.8% similarity with the human p40(phox), that dolphin p47(phox) sequence shared 87.7% similarity with the bovine p47(phox), and that dolphin p67(phox) shared 88.1% similarity with the bovine p67(phox). Western blot analysis using anti-human p40(phox), p47(phox) and p67(phox) antibodies demonstrated that dolphin neutrophil possesses p40(phox), p47(phox) and p67(phox) with similar molecular masses and structures, to each counterpart in human neutrophils, except for the p67(phox) COOH-terminus. These results suggest that dolphin NADPH oxidase cytosolic components have functional activities equivalent to those of human.

Amino Acid Sequence↗

PubMed2001

Oxygen radical generation and expression of NADPH oxidase genes in bottlenose dolphin (Tursiops truncatus) neutrophils.

Oxygen radical generation by stimulation with phorbol myristate acetate (PMA) was evaluated in bottlenose dolphin neutrophils. A Cypridina luciferin analog-dependent chemiluminescent assay demonstrated that dolphin neutrophils generate superoxide by the addition of PMA, and that its superoxide-forming activity is completely suppressed by diphenylene iodonium, a specific inhibitor of NADPH oxidase. These results indicate that dolphin neutrophils possess NADPH oxidase activity. Furthermore, the NADPH oxidase activity (hydrogen peroxide production) in dolphin neutrophils, as well as in human neutrophils, was greater at 37 degrees C than at a lower temperature. RT-PCR with specific primers revealed that dolphin neutrophils expressed the mRNAs of the major NADPH oxidase components, which included membrane-associated flavocytochrome b (gp91(phox) and p22(phox)) and cytosolic factors (p40(phox), p47(phox), and p67(phox)), implying the existence of these protein homologues in dolphin neutrophils.

Animals↗

PubMed2001

Molecular cloning and functional characterization of bottlenose dolphin (Tursiops truncatus) tumor necrosis factor alpha.

Bottlenose dolphin tumor necrosis factor alpha (doTNF-alpha) cDNA was cloned by reverse transcription polymerase chain reaction (RT-PCR) and the nucleic and deduced amino acid sequences were determined. The sequence of the cDNA clones shows that doTNF-alpha has an open reading frame of 699bp encoding 233 amino acids. The nucleic acid sequence of doTNF-alpha indicates 90, 88, 87, and 79% similarity with the cattle, pig, human, and mouse TNF-alpha gene, respectively. Based on the analysis of human and mouse TNF-alpha molecules, doTNF-alpha is processed to a mature protein with 157 amino acids. The 233 amino acids precursor has a hydrophobic region that could serve as a transmembrane domain. The recombinant doTNF-alpha expressed in Escherichia coli as a glutathione S-transferase fusion protein reacted with anti-human TNF-alpha antibody and exerted cytotoxity to the TNF-alpha sensitive murine cell line L929.

Amino Acid Sequence↗

PubMed2001

Promoting effect of colostrum on the phagocytic activity of bovine polymorphonuclear leukocytes in vitro.

Bovine colostrum contains a variety of essential nutrients, antibodies, cytokines, hormones, and growth factors that are important for nutrient supply, host defense, growth and for general neonatal adaptation. We have investigated the effect of bovine colostrum on the phagocytic activity for latex particles by normal peripheral blood polymorphonuclear leukocytes using flow cytometric analysis. The phagocytosis promoting effect was observed in colostrum. The promoting activity showed dose-dependent increase up to 25% at a concentration of colostrum. This activity was maximum in the colostrum obtained at parturition and gradually decreased with the time course of lactation as well as IgG level. Colostrum possessed the higher promoting activity than milk and normal serum. These results indicate that bovine colostrum strongly activates polymorphonuclear leukocyte phagocytosis, suggesting the concernment with development of nonspecific immune system in newborns.

Animals↗

PubMed2001

Analysis of open reading frame 5 in Japanese porcine reproductive and respiratory syndrome virus isolates by restriction fragment length polymorphism.

For the epidemiological survey of porcine reproductive and respiratory syndrome virus (PRRSV) isolated in Japan, the open reading frame (ORF) 5 gene of 37 field isolates in Chiba prefecture from 1991 to 1999 were analyzed by restriction fragment length polymorphism (RFLP). Reverse tanscription-polymerase chain reaction (RT-PCR) amplifying the ORF 5 gene detected 35 field isolates except for 2 isolates. RFLP analysis with MluI, HincII, SacII, HaeIII and MspI demonstrated that 35 field isolates were divided into 14 distinct codes and 34 isolates were distinguished from VR2332-derived modified live PRRSV vaccine, indicating the existence of genetic diversity in PRRSV field isolates in Japan. Only one strain 98-4A had an RFLP pattern identical to the vaccine strain. Nine out of the 35 field isolates (25.7%) had the RFLP code 1-3-2-1-1 and these patterns occurred throughout the examination period. This suggests that these isolates are the prevailing strain of PRRS in Chiba prefecture. RFLP with 5 enzymes demonstrated that various strains existed in the same year, and that there were different codes on the same farm according to the year. These observations indicate that there is a genetic variation among field isolates in very limited regions and some viruses possess the ability to cause their own genomic substitutions within a herd in a short time.

Animals↗

PubMed2001

Detection of rabies virus RNA isolated from several species of animals in Brazil by RT-PCR.

Brain samples from different animal species including humans: five vampire bats, 14 cattle, 12 dogs, 11 cats, two horses, one pig, one sheep and three humans collected from various geographical regions of Brazil were found to be positive for rabies by means of the fluorescent antibody test (FAT) and the mouse inoculation test (MIT). The brain samples were retested for rabies by means of the reverse transcription and polymerase chain reaction (RT-PCR) with 2 primer sets (P1/P2 and RHNI/RHNS3), which amplified full or partial regions on the nucleoprotein (N) gene of the rabies virus, respectively. Brain samples from five vampire bats, 13 cattle, one horse and one sheep failed to yield PCR products when the RHN1/RHNS3 primer pair was used, but all brain samples successfully yielded the products when the P1/P2 primer pair was used. These results suggest that Brazilian rabies virus isolates could be principally divided into two populations according to genetic difference.

Animals↗

PubMed2001

A craniocervical injury-induced syringomyelia caused by central canal dilation secondary to acquired tonsillar herniation. Case report.

The authors report on a 19-year-old man with an acquired tonsillar herniation caused by a craniocervical junction injury in which serial magnetic resonance (MR) images demonstrated patent and isolated segments of the central canal participating in the dilation and then formation of a cervical syrinx. The patient was involved in a motor vehicle accident; he developed tonsillar herniation as a complication of subarachnoid and epidural hemorrhage, predominantly observed around the cisterna magna and upper cervical canal. Repeated MR images obtained over an 11-month period indicated the for mation and acute enlargement of the syrinx. Ten months after the accident, the patient presented with sensory disturbance in both upper extremities and spasticity due to syringomyelia. He underwent craniocervical decompressive surgery and doraplasty, which reduced the size of syringomyelia. The authors postulate that the patent central canal may play a role in determining the location of a syrinx remote from a focus of cerebrospinal fluid obstruction.

Adult↗