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Biomedical subjects

T Kikuchi

Publications and source records attributed to T Kikuchi.

At least 37 records · Page 2Linked to original sources
PubMed2003

Multiple muscles in the AMD quail can be "cross-corrected" of pathologic glycogen accumulation after intravenous injection of an [E1-, polymerase-] adenovirus vector encoding human acid-alpha-glucosidase.

BACKGROUND: Previously, in murine models of acid maltase deficiency (AMD), we demonstrated that intravenous administration of an improved adenovirus (Ad) vector encoding human acid alpha glucosidase (hGAA) resulted in liver transduction, followed by high-level hepatocyte-mediated secretion of hGAA into the plasma space. The hGAA secreted by the liver was taken up and targeted to muscle cell lysosomes. The levels of hGAA achieved by this approach resulted in clearance of lysosomal glycogen accumulations; in some muscle tissues the effect was prolonged (>6 months). We next wished to demonstrate whether this approach could be generalized across divergent species. To accomplish this goal, we determined whether a similar approach would also result in efficacy, but in a quail model of AMD. METHODS: An [E1-, E2b-]Ad vector encoding hGAA was intravenously injected into AMD quails. At several time points thereafter, plasma, liver, and multiple muscle tissues were assayed for evidence of hGAA gene expression, liver-mediated hGAA secretion, uptake of hGAA by skeletal muscles, and evidence of glycogen correction in AMD skeletal muscles. These results were compared with those obtained from mock-injected AMD or wild-type quails. RESULTS: Intravenous [E1-, E2b-]Ad/hGAA vector injection resulted in high-level liver transduction and hepatic secretion of precursor forms of hGAA. The hepatically secreted hGAA was found to not only be efficiently taken up by cardiac and skeletal muscles, but was also proteolytically cleaved and processed equivalently to the quail-GAA protein detected in wild-type quails. The observations suggest that the signals regulating muscle cell uptake (but not proteolytic cleavage) of lysosomal enzymes are conserved and recognized across divergent species of vertebrates. Importantly, once localized to skeletal muscle lysosomes, the hGAA was able to effectively clear the glycogen accumulations present in AMD quail muscles. CONCLUSIONS: Adenovirus-mediated transduction of the hGAA gene, followed by hepatic secretion, uptake, and cross-correction of the pathologic glycogen accumulation noted in multiple muscles of both the AMD mouse and AMD quail, adds support to the notion that gene transfer strategies (Ad-mediated or other agents) targeting liver tissues with the hGAA gene are likely to be highly efficacious in humans affected by AMD.

Adenoviridae↗
PubMed2003

Tissue engineering of the intervertebral disc with cultured annulus fibrosus cells using atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS scaffold).

The objective of the study was to investigate the regeneration of intervertebral discs after laser discectomy using tissue engineering procedures. Annulus fibrosus (AF) cells from the intervertebral discs of Japanese white rabbits were cultured in an atelocollagen honeycomb-shaped scaffold with a membrane seal (ACHMS scaffold), to produce a high-density, three-dimensional culture for up to 3 weeks. Although the DNA content in the scaffold increased at a lower rate than that in the monolayer culture, expression of type II collagen and glycosaminoglycan accumulation in the scaffold were at higher levels than in the monolayer. The AF cells that had been cultured in the scaffold for 7 days were allografted into the lacunae of intervertebral discs of recipients (40 rabbits, 14-16 weeks old; average weight, 3.2 kg), whose nucleus pulposus (NP) had been vaporised with an ICG dye-enhanced laser. The allografted cultured AF cells survived and produced hyaline-like cartilage. Furthermore, the narrowing of the intervertebral disc space of the cell-containing scaffold insertion groups was significantly inhibited after 12 post-operative weeks.

Animals↗
PubMed2003

Squamous cell carcinoma developing in a 12-year-old boy with nonHallopeau-Siemens recessive dystrophic epidermolysis bullosa.

We report a 12-year-old boy with nonHallopeau-Siemens recessive dystrophic epidermolysis bullosa (nHS-RDEB) who developed two skin lesions of squamous cell carcinoma (SCC) on the left foot. The incidence of SCC in nHS-RDEB is much lower than in the HS-RDEB subtype. Furthermore, this boy is the youngest among 92 previously described patients with DEB to develop SCC. This study emphasizes the importance of vigilance in monitoring the possible development of SCC in DEB patients regardless of age or clinical severity.

Age of Onset↗
PubMed2003

Rapid remission of severe pruritus from angiolymphoid hyperplasia with eosinophilia by pulsed dye laser therapy.

A 48-year-old Japanese woman with angiolymphoid hyperplasia with eosinophilia (ALHE) was successfully treated with a flashlamp pulsed dye laser (585 nm, 450 micros pulse duration). The lesion was severely pruritic and had been enlarging slowly for 2 years but was resistant to conventional therapies, including topical, intralesional, and systemic corticosteroid, and cryotherapy. The severe pruritus immediately improved after the first treatment using the pulsed dye laser. The erythema and papules gradually improved without scarring and this was followed by further five treatments over approximately a 4-month interval. No clinical recurrences have been observed 1 year after completion of the treatment. We think that pulsed dye laser therapy is an effective treatment for ALHE in both Japanese as well as Caucasian patients. Pulsed dye laser therapy is also helpful in reducing the pruritus in ALHE patients.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed2003

Cot/Tpl2 is essential for RANKL induction by lipid A in osteoblasts.

Lipopolysaccharide (LPS) is a pathogenic factor that increases bone resorption in periodontal diseases. LPS treatment of osteoblasts was shown to induce the receptor activator of NF-kappa B ligand (RANKL), an essential secretory or membrane-bound factor for osteoclast function, in a manner dependent on extracellular signal-regulated kinase (ERK) activation. However, the mechanisms regulating this process remained unknown. Here, we show that RANKL mRNA induction and ERK activation, when treated with synthetic lipid A (an active center of LPS), were markedly reduced in mouse osteoblasts lacking Cot/Tpl2, which was recently recognized as an essential kinase for the induction of TNF-alpha by LPS in macrophages. In contrast, c-Jun N-terminal kinase (JNK), p38 kinase, Raf-1, and NF-kappa B were normally activated in cot/tpl2-/- osteoblasts. These findings indicate that Cot/Tpl2 is essential for LPS-induced ERK activation and RANKL induction in osteoblasts.

Animals↗
PubMed2002

Quantitative and rapid detection of the trichloroethylene-degrading bacterium Methylocystis sp. M in groundwater by real-time PCR.

We developed a method based on real-time PCR for the specific and rapid enumeration of a trichloroethylene-degrading methanotroph, Methylocystis sp. M, with the aim of monitoring the strain in groundwater. A primer set designed from the nucleotide sequence of the mmoC gene of a soluble methane monooxygenase (sMMO) gene cluster from Methylocystis sp. M was specific to amplify the DNA region from the strain and no PCR products were amplified with the sMMO gene clusters from six other methanotroph strains. The real-time PCR reliably quantified Methylocystis sp. M over at least five orders of magnitude (5x10(6) to 5x10(2 )cells/PCR tube, or 2x10(8) to 2x10(4 )cells/ml). Five cells of Methylocystis sp. M per PCR tube (2x10(2 )cells/ml) were detectable when the cells were suspended in distilled water. The concomitant presence of other methanotrophs in samples did not affect the reliability of enumeration; and recovery of the cells with a membrane filter enabled us to quantify cells of the strain in groundwater. This quantification procedure was completed within 3 h, including preparation time of environmental samples. We conclude that real-time PCR using the mmoC primer set can be used practically to analyze the behavior of Methylocystis sp. M at bioremediation sites.

DNA, Bacterial↗
PubMed2002

DNA methylation and histone deacetylation associated with silencing DAP kinase gene expression in colorectal and gastric cancers.

Death-associated protein kinase is a positive regulator of programmed cell death induced by interferon gamma. To investigate the role of epigenetic inactivation of death-associated protein kinase in gastrointestinal cancer, we examined the methylation status of the 5' CpG island of the death-associated protein kinase gene. Methylation of the 5' CpG island was detected in 3 of 9 colorectal and 3 of 17 gastric cancer cell lines, while among primary tumours, it was detected in 4 of 28 (14%) colorectal and 4 of 27 (15%) gastric cancers. By contrast, methylation of the edge of the CpG island was detected in virtually every sample examined. Death-associated protein kinase expression was diminished in four cell lines that showed dense methylation of the 5' CpG island, and treatment with 5-aza-2'-deoxycitidine, a methyltransferase inhibitor, restored gene expression. Acetylation of histones H3 and H4 in the 5' region of the gene was assessed by chromatin immunoprecipitation and was found to correlate directly with gene expression and inversely with DNA methylation. Thus, aberrant DNA methylation and histone deacetylation of the 5' CpG island, but not the edge of the CpG island, appears to play a key role in silencing death-associated protein kinase expression in gastrointestinal malignancies.

Apoptosis Regulatory Proteins↗
PubMed2002

Adeno-associated virus-mediated transfer of human acid maltase gene results in a transient reduction of glycogen accumulation in muscle of Japanese quail with acid maltase deficiency.

Glycogen storage disease type II (GSD II), Pompe's disease, is caused by the deficiency of acid alpha-D-glucosidase (GAA) in lysosome and is the most common form of GSD in Taiwan. Most cases are the infantile form. The disease is relentless and most patients die of cardiac failure and respiratory tract infection in the first year of life. At present, no treatment has been proved effective for this fatal disease. The applicability of enzyme replacement therapy is under investigation. However, high price and transient efficiency are the major problems to be solved. Accordingly, gene therapy by viral method has been conducted. In this study we constructed a plasmid that contained 5'-shortened BglII-NotI fragment human GAA cDNA, downstream of CMV promoter and bovine growth hormone polyadenylation signal, as well as AAV ITR region. When fibroblasts obtained from GSD II patients were cultured and infected with rAAV-GAA, the GAA activity of the fibroblasts increased four- to five-fold. Using acid maltase deficient (AMD) Japanese quail as the animal model, rcAAV-GAA 0.1 ml per site (1 x 10(9)-10) particles), totally 10 different sites to make 1 ml (1 x 10(1)0-11) particles), was injected into unilateral deep pectoral muscle of AMD quails. Medium (hepes) was only injected in the same way into the contralateral deep pectoral muscle to serve as control. Four days after injection, PAS staining showed disappearance of the glycogenosomes with regeneration of myocytes surrounding the intramuscular injected area as compared with the contralateral muscle of the same birds. Using anti-GAA monoclonal antibody, GAA was demonstrated on the regenerated myocytes by immunohistochemical staining and absent on the contralateral muscle of the same birds. Nevertheless, T lymphocytes infiltration was noted in both the rcAAV-GAA and hepes (medium) injected muscles and more prominent in the rcAAV-GAA-injected site. Functional evaluation demonstrated that wing flapping movement improved with wide flapping in the rAAV-GAA injected side, but not in the counterpart. Unfortunately, these histochemical and functional improvements faded away in 14 days, probably due to destruction of rcAAV by cell-mediated immunity of infiltrated T cells. Taken together, the present study suggests that rAAV can enter either human or quail cells and express and effectively reduce the glycogen accumulation in the skeletal muscle of AMD quails. These preliminary results are similar to these of low-dose rGAA replacement therapy. The mechanisms underlying the induction of cell-mediated immunity are unknown. How to elevate the number of packaged AAV, enhance the infectivity of AAV and reduce cell-mediated immunity must be solved in the future.

Animals↗
PubMed2002

Localization of the muscular dystrophy AM locus using a chicken linkage map constructed with the Kobe University resource family.

A chicken linkage map, constructed with the Kobe University (KU) resource family, was used to locate the genetic locus for muscular dystrophy of abnormal muscle type (AM). The KU resource family is a backcross pedigree with 55 offspring produced from the mating of a White Leghorn F-line (WL-F) male and a hybrid female produced from a cross between the WL-F male and a female of the Fayoumi OPN line who was homozygous for the AM gene. In total, 872 loci were genotyped on the pedigree; 749 (86%) were informative and mapped to 38 linkage groups. These informative loci included 649 AFLPs, 93 MS, three functional genes, the AM locus, sex phenotype, and two red blood cell loci. The remaining 123 markers were unlinked. Nineteen of the 38 KU linkage groups were assigned to macrochromosomes 1-8 and 11 microchromosomes including chromosome W, while 19 linkage groups were unassigned. The total map was 3569 cM in length, with an average marker interval of 4.8 cM. The AM locus was mapped 130 cM from the distal end of chromosome 2q.

Animals↗
PubMed2002

A new deletion mutation in bovine Claudin-16 (CL-16) deficiency and diagnosis.

Bovine claudin-16/paracellin-1 (CL-16/PCLN-1) deficiency is an autosomal recessive disorder caused by a 37-kb deletion mutation containing the first four exons of the CL-16 gene, which leads to the absence of the CL-16 transcript (type-1 mutation). A PCR-based DNA test for the CL-16 mutation (type-1) was used to screen a herd of Wagyu cattle. A recent report suggested that affected cattle can be bred by dams diagnosed as normal, suggesting the presence of a new mutation in the CL-16 locus. We identified the new mutation as a 56-kb deletion containing exon-1 to -4 and 21-bp of exon-5 of CL-16, and refer to this as a type-2 mutation. A DNA test for specific for this mutation was then established.

Animals↗
PubMed2002

Kinetics of the nucleoside triphosphate hydrolase of Toxoplasma gondii in mice with acute and chronic toxoplasmosis.

The kinetics of the nucleoside triphosphate hydrolase (NTPase) of Toxoplasma gondii was examined using an avidin-biotin sandwich-ELISA (ABS-ELISA) based on an anti-NTPase monoclonal antibody, 6C6. The RH and ME49 strains of the parasite were used to produce acute and chronic infections in mice, respectively. In the acute model, detectable serum concentrations of NTPase were observed from day 1 post-infection and gradually increased until the death of the mice. They were associated with parasitaemia (as estimated by bioassay). No anti-T. gondii antibody could be detected at any time. In the chronic model, in which 20 T. gondii ME49 cysts were given to each mouse per os, the NTPase concentration generally increased from day 3, peaked between days 7 and 14 and then declined. However, one of the four mice used still had a high serum concentration of NTPase on day 35. Again, detectable NTPase concentrations occurred when the mice had parasitaemias. Antibody to T. gondii was detected from day 7 (IgM) or 10 (IgG) and brain cysts were observed from day 14. Since detectable serum concentrations of NTPase appear to be associated with parasitaemia in both acute and chronic toxoplasmosis, the ABS-ELISA of the enzyme may make a useful diagnostic tool.

Acid Anhydride Hydrolases↗
PubMed2001

Glycosaminoglycan accumulation in primary culture of rabbit intervertebral disc cells.

STUDY DESIGN: With the heterogeneity of the intervertebral disc as the focus, intervertebral discs from normal young rabbits were separated into nucleus pulposus (NP), inner anulus fibrosus (IAF), and outer anulus fibrosus (OAF) zones. Disc cells from each zone were isolated and propagated under monolayer and within agarose gel culture. The metabolism of these cultured disc cells was examined in terms of glycosaminoglycan (GAG) accumulation. OBJECTIVES: The object was to study the metabolism of disc cells derived from each zone and characterize them on the basis of GAG accumulation and composition. SUMMARY OF BACKGROUND DATA: It has been shown that three-dimensional culture systems, such as within-agarose gels or in alginate beads, permit long-term maintenance of the articular chondrocyte phenotype in vitro. However, little has been reported on how the metabolism of intervertebral disc cells, especially GAG accumulation, is affected by different culture conditions. METHODS: Cells from each zone were subjected to monolayer or three-dimensional culture for up to 12 days. GAG accumulation in the different culture systems was analyzed using chemical, histologic, and immunohistologic methods. Differences of GAG and DNA content among NP, IAF, and OAF cells were statistically evaluated by analysis of variance. The data of keratin sulfate content in three-dimensional culture were compared with that in monolayer culture using nonparametric Mann-Whitney U test. RESULTS: Monolayer culture revealed that increases in GAG content were significantly higher in IAF cells than in OAF cells. However, in three-dimensional culture GAG content was similar in the two groups. AF cells in three-dimensional cultures showed immunohistochemical localization of chondroitin sulfate and keratan sulfate, suggesting the existence of pericellular matrix. High performance liquid chromatography confirmed the expression of keratan sulfate in cultured cells. CONCLUSIONS: GAG accumulation in cultures of cells from different zones of the intervertebral disc varied according to the culture conditions used. The importance of choosing the appropriate culture systems to meet the objectives of a study should be emphasized.

Analysis of Variance↗
PubMed2001

Intratumoral administration of low doses of an adenovirus vector encoding tumor necrosis factor alpha together with naive dendritic cells elicits significant suppression of tumor growth without toxicity.

Although tumor necrosis factor alpha (TNF-alpha) is a potent cytokine with a myriad of innate immune antitumor properties, systemic administration of TNF-alpha is associated with significant toxicity, limiting the use of the TNF-alpha protein as an antitumor therapeutic. On the basis of the knowledge that dendritic cells (DCs) play a central role in initiating antitumor adaptive immune responses, we hypothesized that intratumoral administration of low doses of an adenovirus encoding TNF-alpha (AdTNF-alpha) together with syngeneic DCs would act synergistically to suppress preexisting tumors. As a model, four different tumor cell lines, all resistant in vitro to the TNF-alpha protein, were implanted in syngeneic mice, and established tumors received intratumor AdTNF-alpha alone or in combination with DCs. At high doses (10(9) PFU), AdTNF-alpha alone suppressed tumor growth, but was associated with systemic toxicity. A 100-fold lower AdTNF-alpha concentration (10(7) PFU) or high doses of the control vector AdNull had no systemic toxicity, but also minimal suppression of tumor growth. In contrast, local administration of the low dose (10(7) PFU) of AdTNF-alpha in combination with syngeneic DCs (AdTNF-alpha + DCs) elicited marked tumor suppression without toxicity. Administration of AdTNF-alpha + DCs into tumors elicited tumor-specific cytotoxic T cells and protected animals against subsequent challenge with the same tumor, suggesting that AdTNF-alpha + DC therapy induced tumor-specific adaptive immune host responses. Consistent with this concept, studies with syngeneic knockout mice showed that MHC class I molecules on DCs as well as CD8(+) T cells were necessary for the antitumor effect of intratumor AdTNF-alpha + DCs. These data demonstrate that the combination of intratumoral administration of the TNF-alpha cDNA together with naive DCs can evoke tumor suppression without systemic toxicity, providing a new paradigm for the use of TNF-alpha as antitumor therapy.

Adenoviridae↗
PubMed2001

Molecular cloning and characterization of human PTB-like protein: a possible retinal autoantigen of cancer-associated retinopathy.

Human homologue of polypyrimidine tract binding protein (PTB), a possible autoantigen for cancer-associated retinopathy (CAR), was isolated from a human retinal cDNA library. This homologue, named PTB-like protein (PTBLP), encodes a 532 amino acid residue and has a 75% homology to the human PTB. The human PTBLP had four RNA recognition motifs (RRMs) and had a RNA binding ability. There are four splicing variants in PTBLP. The CAR serum recognized the full length form of PTBLP and the antigenic determinant was localized within 12 amino acids of the C-terminal region. The sequence was included in the fourth RRM sequence.

Amino Acid Sequence↗
PubMed2001

Loss of Uch-L1 and Uch-L3 leads to neurodegeneration, posterior paralysis and dysphagia.

Altered function of the ubiquitin pathway has been implicated in the etiology of neurodegeneration. For example, gracile axonal dystrophy (gad) mutant mice, which harbor a deletion within the gene encoding ubiquitin C-terminal hydrolase L1 (Uch-L1), display sensory ataxia followed by posterior paralysis and lethality. We previously showed that mice homozygous for a targeted deletion of the related Uch-L3 gene are indistinguishable from wild-type. To assess whether the two hydrolases have redundant function, we generated mice homozygous for both Uch-L1gad and Uch-L3Delta3-7. The double homozygotes weigh 30% less than single homozygotes and display an earlier onset of lethality, possibly due to dysphagia, a progressive loss in the ability to swallow food. This is consistent with histological analysis that revealed axonal degeneration of the nucleus tractus solitarius (NTS) and area postrema (AP) of the medulla. The NTS is essential for central nervous system control of swallowing. The double homozygotes also display a more severe axonal degeneration of the gracile tract of the medulla and spinal cord than had been observed in Uch-L1gad single homozygotes. In addition, degeneration of dorsal root ganglia cell bodies was detected in both the double homozygotes and Uch-L3Delta3-7 single homozygotes. Given that both Uch-L1gad and Uch-L3Delta3-7 single homozygotes display distinct degenerative defects that are exacerbated in the double homozygotes, we conclude that Uch-L1 and Uch-L3 have both separate and overlapping functions in the maintenance of neurons of the gracile tract, NTS and AP. This study is the first to successfully document dysphagia in the mouse and is a potentially valuable resource for understanding human neurodegenerative disorders that cause swallowing defects.

Animals↗
PubMed2001

Immunolocalization of voltage-gated potassium channel Kv3.1b subunit in the cochlea.

Immunohistochemical localization of voltage-gated potassium channel Kv3.1b subunit was studied in the cochlea. Intense Kv3.1b-like immunoreactivity was present in the type I, type III, type IV and suprastrial fibrocytes of the cochlear lateral wall. Immunostaining was also found in the interdental cells and the fibrocytes of the spiral limbus and in the supralimbal dark cells. K+ ions, which play a pivotal role in the mechanosensory transduction process in the inner ear, are recycled via gap junctional networks in the cochlea. These results suggest that the voltage-gated potassium channel, containing Kv3.1b, in the cochlear lateral wall fibrocytes may control the intracellular potential and play an important role in regulating the potassium ion recycling mechanism via gap junctions in the inner ear.

Acetic Acid↗
PubMed2001

Alteration of rCBF in Alzheimer's disease patients with delusions of theft.

We investigated the neural substrate of the delusion of theft in patients with Alzheimer's disease (AD). Nine AD patients with only one type of delusion (delusions of theft) and nine age, cognitive function-matched AD patients without any type of delusions were selected from 334 consecutive outpatients of Ehime University Hospital. All subjects underwent (99m)Tc-HMPAO SPECT scanning, and SPECT images were analyzed by Statistical Parametric Mapping (SPM). AD patients with delusions of theft showed significant hypoperfusion in the right medial posterior parietal region compared to patients without delusions. Our data suggest that attention impairment or lack of awareness of illness caused by right parietal dysfunction might play a role in producing the delusion of theft.

Age Factors↗