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Toshihiko Kikuchi

Publications and source records attributed to Toshihiko Kikuchi.

13 recordsLinked to original sources
PubMed2006

Development of a microsatellite marker set applicable to genome-wide screening of cynomolgus monkeys (Macaca fascicularis).

To develop a microsatellite marker set applicable to genome-wide screening of cynomolgus monkeys (Macaca fascicularis), 148 microsatellite markers were selected from the human genome database. The polymorphisms and inheritance of PCR products were determined by screening twenty unrelated monkeys and by analysis of three families, respectively. As a result, 106 primers (72%) gave PCR products of the size expected for humans and rhesus monkeys. Among these products, polymorphism and single-gene inheritance in cynomolgus monkeys was observed for 66 markers (62%). The average number of alleles at the 66 polymorphic loci was 5.86 (range 2-10), and average heterozygosity was 0.63 (range 0.10-0.88). This is the first report of microsatellite markers for cynomolgus monkeys. Chromosomal mapping of these markers is now in progress.

Animals↗
PubMed2006

Developmental order driving the relationship between executive functions and theory of mind: a case study.

Several studies have suggested there is a developmental link between executive functions and theory of mind. However, the developmental order driving the relationship is not well understood. The main reason is that the development of executive function parallels the development of theory of mind in normally developing children. In this paper, a case (H.Y.) is reported. H.Y. had lived in a persistent vegetative state for 6 years after encephalitis at the age of 10. He showed a developmental order driving the relationship between executive functions and theory of mind. These findings are consistent with recent suggestions that development of executive function might be important as a predecessor of either the ability to understand false beliefs or the ability to express that understanding.

Adult↗
PubMed2005

Survey of captive cynomolgus macaque colonies for SRV/D infection using polymerase chain reaction assays.

The exogenous simian type D retroviruses (SRV/Ds) are prevalent in macaque monkeys and sometimes cause immunodeficiency with anemia, weight loss, and persistent unresponsive diarrhea. SRV/D isolates are classified as subtypes 1 to 6, and the entire sequences of the gag region of SRV/D-1, -2, and -3 and SRV/D-Tsukuba (SRV/D-T) have been determined. We designed specific primers in the gag region of SRV/D-T that enabled us to directly detect by polymerase chain reaction (PCR) SRV/D-T proviral DNA sequences in DNA extracted from whole blood. Using this assay and another PCR assay that detects multiple SRV/D subtypes, we performed a survey for SRV/D infection in our specific pathogen-free (SPF) and conventional colonies at Tsukuba Primate Center (TPC). In the SPF colony, no SRV/D signal was detected in any animal. On the other hand, SRV/D-T was detected in 11 of 49 animals (22.5%) in the conventional colony. SRV/D-T was the only SRV/D subtype detected. Consequently, SRV/D-T is the major SRV/D subtype present in cynomolgus monkeys at TPC.

Animals↗
PubMed2004

Isolation and characterization of a new simian retrovirus type D subtype from monkeys at the Tsukuba Primate Center, Japan.

Exogenous type D simian retroviruses (SRV/D) are prevalent in captive and feral populations of various macaque monkeys. Thus far, five subtypes of SRV/Ds have been reported, three of which (SRV-1, -2 and -3) have been molecularly characterized. Two SRV/D strains (N27 and T150) were isolated from seropositive cynomolgus macaques at the Tsukuba Primate Center (TPC) in Japan, showing clinical signs of SRV/D infection, including anemia and persistent unresponsive diarrhea. Electron microscopy demonstrated that both SRV/D isolates have a virion morphology typical of type D retrovirus. The SRV/D N27 and T150 isolates were essentially the same based on sequence analysis. From homology analysis of the entire gag sequence, the N27 isolate is closely related to the other known SRV/Ds but is distinct from the three molecularly characterized SRV/Ds. Thus, we have tentatively designated the N27 and T150 viruses isolated from TPC cynomolgus macaques as SRV/D-Tsukuba (SRV/D-T).

Amino Acid Sequence↗
PubMed2004

Endocochlear potential and endolymphatic K+ changes induced by gap junction blockers.

OBJECTIVE: To examine the effects of gap junction blockers on the endocochlear potential (EP) and endolymphatic potassium concentration ([K(+)](e)). MATERIAL AND METHODS: The EP and [K(+)](e) were monitored using double-barreled ion-selective microelectrodes in the second turn of the guinea pig cochlea during perilymphatic perfusion. RESULTS: When the perilymphatic scalae of the cochlea were perfused with artificial perilymph containing 10 mM n-heptanol the EP was decreased by -8.8+/-1.4 mV (n=10), and this was accompanied by a decline in the [K(+)](e) of -6.7+/-2.1 mM (n=6). Perilymphatic application of 10 mM hexanol also produced declines in both the EP and [K(+)](e). In control studies, perilymphatic perfusion with 10 mM ethanol showed no remarkable changes in either the EP or [K(+)](e). Anoxia during perfusion with heptanol resulted in the generation of a negative EP, similar to the situation in controls. CONCLUSIONS: A decline in the EP together with a lowering of [K(+)](e) induced by long-chain n-alkanols, which act as gap junction blockers, may be explained by an interruption in potassium ion transport related to a gap junction dysfunction.

Alcohols↗
PubMed2003

Surgical treatment of subperiosteal abscess of the orbit: Sendai's ten-year experience.

OBJECTIVE: One of the common complications of acute infection of the paranasal sinus is cellulitis of the orbit. This is secondary to the spread of infection through the very thin bony wall between the ethmoid sinuses and the orbit, the roof of the orbit in frontal sinusitis, and the floor of the orbit in maxillary sinusitis. When the infection does not penetrate the periorbita, it dissects under the periosteum and forms subperiosteal abscess. METHODS: We experienced 10 patients with subperiosteal abscess for 10 years from 1992 to 2002 that required surgical drainage. The age of the patients ranged from 4 to 76 years including five males and five females. RESULTS: Successful and safe drainage of the abscess with endoscopic sinus surgery was obtained in four patients while six patients required external surgery. The selection of the surgical approach depended upon the localization of abscess in the orbit. Five of the seven patients with visual disturbance resulted in a complete recovery of vision after surgery. However, there was no improvement of visual acuity in the other two patients who had already shown severe damage of vision prior to treatment. CONCLUSION: Ocular symptoms such as exophthalmos, double vision, and ptosis subsided completely in all patients. It is suggested that prompt diagnosis and surgical drainage before severe loss of visual acuity rescue or recover the vision.

Abscess↗
PubMed2003

Expression of glutamate transporter GLAST in the developing mouse cochlea.

The immunohistochemical localization of glutamate transporter GLAST in the developing mouse cochlea was studied at different ages between 0 and 30 days after birth (DAB). In the adult mouse cochlea, intense GLAST-like immunoreactivity was found in the supporting cells adjacent to the inner hair cells of the organ of Corti, the type II and suprastrial fibrocytes of the cochlear lateral wall, the fibrocytes of the spiral limbus and the satellite cells surrounding the spiral ganglion cells. At 0 DAB, weak GLAST-like immunoreactivity was found in the supporting cells around the immature inner hair cells. Immature fibrocytes in the cochlea were also positively immunostained. At 3 DAB, weak immunostaining of GLAST appeared in the immature satellite cells in the spiral ganglion. The GLAST-like immunoreactivity in the supporting cells around the inner hair cells, in the fiborocytes in the spiral ligament and the spiral limbus and in the satellite cells in the spiral ganglion increased progressively during the second postnatal week, and reached the adult level at 15 DAB. This time course correlates with the electrophysiological onset and maturation of the mouse auditory function, which is mediated by glutamatergic neurotransmission. These results suggest that the expression of GLAST may be needed for the efficient removal and metabolism of the released glutamate in the cochlea and may play important roles in the onset and maturation of the auditory system.

Amino Acid Transport System X-AG↗
PubMed2002

Late-onset hearing loss in a mouse model of DFN3 non-syndromic deafness: morphologic and immunohistochemical analyses.

Recently, we reported that homozygous males and females of a mouse model of DFN3 non-syndromic deafness generated by the deletion of Brn-4 transcription factor showed profound deafness due to severe alterations in the cochlear spiral ligament fibrocytes from the age of 11 weeks, whereas no hearing loss was recognized in young female heterozygotes. It is known that a part of obligate female carriers of DFN3 showed progressive hearing loss. In the present study, we examined the late-onset effect of Brn-4 deficiency on the hearing organ of the mouse. About one third of heterozygous female mice revealed late-onset profound deafness at the age of 1 year. Furthermore, in these deafened heterozygotes, characteristic abnormalities in Reissner's membrane attachment and type II fibrocytes in the suprastrial zone became evident under light microscope, similar to homozygous female mice. A significant reduction in the immunoreactivity of connexin 26 (Cx26), connexin 31 (Cx31), Na,K-ATPase and Na-K-Cl cotransporter in the spiral ligament fibrocytes was observed in aged heterozygotes showing late-onset profound deafness. The late-onset phenotype observed in heterozygous mutant mice, being consistent with the progressive deafness observed in human female heterozygotes, may be explained by alterations of the ion transport systems in the spiral ligament fibrocytes.

Age of Onset↗
PubMed2002

Comparative immunohistochemical localizations of aquaporin-1 and aquaporin-4 in the cochleae of three different species of rodents.

The species-specific difference of the immunohistochemical localization of aquaporin-1 (AQP1) and aquaporin-4 (AQP4) was investigated in the cochleae of the 3 different species of rodents, including guinea pig, mouse and Mongolian gerbil. In the guinea pig cochlea, intense AQP1-like immunoreactivity was present in the type III fibrocytes in the spiral ligament and the mesenchymal cells just below the basilar membrane. Immunostaining was also found in some type IV fibrocytes in the spiral ligament, fibrocytes in the spiral limbus and mesenchymal cells lining the perilymphatic space against the bony otic capsule. In contrast, no remarkable immunostaining was found in the basilar membrane of the mouse cochlea. The medial part of the Reissner's membrane was positively immunostained with anti-AQP1 antibody only in the mouse cochlea. In the gerbil cochlea, AQP1-like immunoreactivity was weak compared with the other 2 species. AQP4 was found in the cochlear supporting cells, including Claudius cells, Hensen's cells and inner sulcus cells of the 3 rodent species. AQP4 was also expressed in some interdental cells of the spiral limbus. Weak immunoreactivity was also found in the root cells only in the upper turns of the guinea pig cochlea. In contrast, no detectable immunoreactivity was found in the root cells of the other 2 species. The results obtained in the present study provide the first evidence for the existence of the species differences in the expression of the AQP1 and AQP4 proteins in the rodent cochlea.

Animals↗
PubMed2002

Endoscopic sinus surgery in cases of cholesterol granuloma of the maxillary sinus.

Cholesterol granuloma is usually associated with middle ear disease and is very rare in the paranasal sinuses. We report a case of cholesterol granuloma originating in the maxillary sinus of a 52-year-old female. Endoscopic sinus surgery was performed on the left maxillary sinus, and the cholesterol granuloma was successfully removed by the middle meatal antrostomy. Light microscopic examination showed granulomatous tissue with typical cholesterol clefts, multinucleated foreign body giant cells, small areas of hemorrhage, hemosiderin-laden macrophages and plasma cells. We also describe the details of the endoscopic surgical techniques employed in the treatment of this disorder.

Cholesterol↗
PubMed1996

A Ferromagnetic Interaction between Cu(2+) Centers through a [CrO(4)](2-) Bridge: Crystal Structures and Magnetic Properties of [{Cu(acpa)}(2)(&mgr;-MO(4))] (M = Cr, Mo) (Hacpa = N-(1-Acetyl-2-propyridene)(2-pyridylmethyl)amine).

The reaction of [Cu(acpa)](+) with [MO(4)](2)(-) (Hacpa = N-(1-acetyl-2-propyridene)(2-pyridylmethyl)amine and M = Cr and Mo) in water-methanol or water-acetonitrile solution affords dinuclear copper(II) complexes with metalate bridges, [{Cu(acpa)}(2)(&mgr;-CrO(4))].4CH(3)OH.4H(2)O (1) and [{Cu(acpa)}(2)(&mgr;-MoO(4))].4H(2)O (2), respectively. The crystal structures and the magnetic properties have been studied. Complexes 1 and 2 are isomorphous and the structures are made up of discrete dimers in which two copper(II) ions are bridged by the [MO(4)](2)(-) anion. The coordination geometry about the copper(II) ions is square planar with a N(2)O chelate group from acpa and an oxygen atom from [MO(4)](2)(-). Magnetic susceptibility measurements for 1 revealed that a ferromagnetic interaction between copper(II) ions is propagated through the [CrO(4)](2)(-) bridge and the coupling constant (2J) was evaluated to be 14.6(1) cm(-)(1) (H = -2JS(1).S(2)). In 2, two copper(II) ions bridged by [MoO(4)](2)(-) anion are antiferromagnetically coupled with the 2J value of -5.1(4) cm(-)(1). The ferromagnetic interaction in 1 is explained by means of the orbital topology of frontier orbitals. Crystal data: 1, monoclinic, space group P2(1)/m, a = 8.349(2) Å, b = 17.616(3) Å, c = 10.473 Å, beta = 107.40(2) degrees, Z= 2; 2, monoclinic, space group P2(1)/m, a = 8.486(2) Å, b = 18.043(3) Å, c = 9.753(2) Å, beta = 95.82(2) degrees, Z = 2.

Journal Article↗