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Biomedical subjects

T Deguchi

Publications and source records attributed to T Deguchi.

At least 19 recordsLinked to original sources
PubMed2006

Brain-derived neurotrophic factor-immunoreactive primary sensory neurons in the rat trigeminal ganglion and trigeminal sensory nuclei.

Immunohistochemistry for brain-derived neurotrophic factor (BDNF) was performed on the rat trigeminal ganglion (TG). The immunoreactivity (IR) was detected in 46% of TG neurons. These neurons were mostly small- or medium-sized (range, 149.7-1246.3 microm2; mean +/- SD = 373.4 +/- 151.6 microm2). A double immunofluorescence method also revealed that 54% of BDNF-immunoreactive (IR) neurons were immunoreactive for calcitonin-gene-related peptide. In addition, 93% of BDNF-IR TG neurons contained vanilloid receptor subtype 1. However, the co-expression of BDNF and vanilloid receptor 1-like receptor was very rare (less than 1%). In the trigeminal sensory nuclei, laminae II of the medullary dorsal horn was abundant in presumed BDNF-IR axon terminals. Such profiles were also detected in the dorsolateral part of the subnucleus oralis. The retrograde tracing and immunohistochemical methods demonstrated that BDNF-IR was common among cutaneous TG neurons (47%) but not tooth pulp TG neurons (13%). The present study indicates that BDNF-IR TG neurons have unmyelinated axons and project to the superficial medullary dorsal horn. It is likely that BDNF-containing neurons in both the trigeminal and spinal sensory systems have similarities in morphology and function. However, the content of BDNF in TG neurons probably depends on their peripheral targets. BDNF seems to convey nociceptive cutaneous input to the trigeminal sensory nuclei.

Animals↗
PubMed2006

Adenoviral-mediated overexpression of membrane-bound human FasL and human decoy Fas protect pig islets against human CD8+ CTL-mediated cytotoxicity.

Pig islets are considered to be most suitable source of islets for xenotransplantation into patients with type 1 diabetes mellitus. However, cellular rejection, especially CD8+ CTL-mediated cytotoxicity, remains a formidable barrier preventing long-term xenograft survival. Our previous study demonstrated that human CD8+ CTLs were highly detrimental to xenograft cells and that this strong cytotoxicity of human CTLs was mediated mainly by the Fas/FasL apoptotic pathway. Furthermore, we exploited novel methods for inhibiting human CD8+ CTL-mediated xenocytotoxicity with overexpression of membrane-bound human FasL and human decoy Fas antigen in xenografted cells. In the present study, we assessed the cytoprotective effects of these novel inhibitory molecules overexpressed by an adenoviral-mediated system in pig islets. Isolated pig islets were transfected with adenovirus vector encoding either human decoy Fas or membrane-bound human FasL genes. Thirty percent to 60% of transfected pig islets expressed these molecules producing 60% to 88% suppression of CTL killing compared with parental pig islets. These data indicated that pig islet grafts isolated from transgenic pigs with either membrane-bound human FasL or human decoy Fas antigen genes may control the innate cellular response to xenografts, and creating a window of opportunity to facilitate xenograft survival.

Adenoviridae↗
PubMed2006

A novel strategy for preventing human CD8+ cytotoxic T lymphocyte-mediated cytotoxicity against pig endothelial cells by overexpression of pig cellular FLICE-like inhibitory protein (c-FLIP) gene.

Human CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity in xenograft recipients is an important obstacle for successful xenotransplantation of pig organs into humans. In our previous study, we demonstrated that xenocytotoxicity of human CD8+ CTL detrimental to pig endothelial cells (PEC) is mediated mainly by the Fas/FasL apoptotic pathway. Furthermore, we developed new methods to prevent this CTL killing by extracellular remodeling using overexpression of human decoy Fas antigen and membrane-bound human FasL on pig xenograft cells. The cellular FLICE-inhibitory protein (c-FLIP), a caspase-8 inhibitor that lacks the cysteine domain, is a negative regulator of death receptor-mediated apoptosis. c-FLIP proteins exist as long (c-FLIP(L)) and short (c-FLIPs) splice variants, both capable of protecting cells from death receptor-mediated apoptosis. In this report, we have demonstrated that both pig c-FLIPs and pig c-FLIP(L) significantly inhibit human CD8+ CTL-mediated xenocytotoxicity toward stably transfected PEC, although the expression level of pig Fas antigen on cell surface was not changed. These data suggested that intracellular remodeling with overexpression of pig c-FLIP in xenograft cells may decrease the innate cellular responses against xenografts, facilitating long-term xenograft survival.

Animals↗
PubMed2006

Increase of galanin in trigeminal ganglion during tooth movement.

It is known that nerve fibers containing neuropeptides such as galanin increase in the periodontal ligament during experimental tooth movement. However, the origin of galanin-containing nerve fibers in the periodontal ligament remains unclear. This study was conducted to examine our hypothesis that the increased galanin nerve fibers have a sensory neuronal origin, and that the peptide is associated with pain transmission and/or periodontal ligament remodeling during experimental tooth movement. In control rats, galanin-immunoreactive trigeminal ganglion cells were very rare and were observed predominantly in small ganglion cells. After 3 days of experimental tooth movement, galanin-immunoreactive trigeminal ganglion cells significantly increased, and the most marked increase was observed at 5 days after experimental tooth movement. Furthermore, their cell size spectrum also significantly changed after 3 and 5 days of movement: Medium-sized and large trigeminal ganglion cells began expressing, and continued to express, galanin until 14 days after experimental tooth movement. These findings suggest that the increase of galanin in the periodontal ligament during experimental tooth movement at least partially originates from trigeminal ganglion neurons and may play a role in pain transmission and/or periodontal remodeling.

Animals↗
PubMed2006

Expression of clusterin, XIAP and survivin, and their changes by camptothecin (CPT) treatment in CPT-resistant PC-3 and CPT-sensitive LNCaP cells.

AIM: Clusterin and IAPs (inhibitor of apoptosis proteins), such as survivin and XIAP, are known to be related to chemo-resistance in several cancer cells. In the current study, we investigated their expression levels in human prostate cancer cell lines, LNCaP and PC-3 which are sensitive and resistant to camptothecin (CPT), topoisomerase I inhibitor, respectively. METHODS: LNCaP and PC-3 cells were cultured in the presence of CPT, cell death was evaluated using Hoechst 33342 and propidium iodide (PI) double staining. The expression of clusterin, XIAP and survivin on mRNA and protein levels was investigated by semi-quantitative RT-PCR and Western blotting, respectively. RESULTS: Our data showed that 24 h treatment of LNCaP cells with 0.5 and 3.0 microM CPT resulted in higher number of apoptotic cells, than that in PC-3 cells. Western blot analysis revealed that the clusterin level in PC-3 cells was 5-fold higher than that in LNCaP cells. In contrast, XIAP expression level in PC-3 cells was lower than that in LNCaP cells, and survivin levels were similar in these two cell lines. Treatment with 0.5 and 3.0 microM CPT resulted in the reduced survivin and XIAP expression in both cell lines, while clusterin expression remained unchanged in LNCaP cells, but was increased in PC-3 cells. CONCLUSION: The results suggest that clusterin may take a greater part in CPT-resistance than survivin and XIAP in PC-3 cells.

Antineoplastic Agents, Phytogenic↗
PubMed2005

In vitro activity of fluoroquinolones against Mycoplasma genitalium and their bacteriological efficacy for treatment of M. genitalium-positive nongonococcal urethritis in men.

We investigated the minimum inhibitory concentrations of some fluoroquinolones for Mycoplasma genitalium and their bacteriological efficacy in the treatment of M. genitalium-positive nongonococcal urethritis. In vitro, levofloxacin was less active than gatifloxacin, tosufloxacin, and sparfloxacin. In vivo, the bacteriological efficacy of gatifloxacin was superior to that of levofloxacin or tosufloxacin.

Fluoroquinolones↗
PubMed2003

The use of small titanium screws for orthodontic anchorage.

The use of conventional dental implants for orthodontic anchorage is limited by their large size. The purpose of this study was to quantify the histomorphometric properties of the bone-implant interface to analyze the use of small titanium screws as an orthodontic anchorage and to establish an adequate healing period. Overall, successful rigid osseous fixation was achieved by 97% of the 96 implants placed in 8 dogs and 100% of the elastomeric chain-loaded implants. All of the loaded implants remained integrated. Mandibular implants had significantly higher bone-implant contact than maxillary implants. Within each arch, the significant histomorphometric indices noted for the "three-week unloaded" healing group were: increased labeling incidence, higher woven-to-lamellar-bone ratio, and increased osseous contact. Analysis of these data indicates that small titanium screws were able to function as rigid osseous anchorage against orthodontic load for 3 months with a minimal (under 3 weeks) healing period.

Analysis of Variance↗
PubMed2003

Galanin-immunoreactive nerve fibers in the periodontal ligament during experimental tooth movement.

Neuropeptides have been suggested to play a role in pain transmission during orthodontic tooth movement. We examined this hypothesis by examining the effect of orthodontic tooth movement on the expression of galanin (GAL)-immunoreactive (ir) nerve fibers in the periodontal ligament (PDL) of one mesial root (MR) and two distal roots (DRs) of the rat maxillary first molar. In control rats, GAL-ir fibers were very rare in the PDL. One day after the insertion of the elastic band, the number of GAL-ir fibers increased, becoming most numerous at 3 days. From 5 to 28 days, GAL-ir fibers tended to decrease. Electron microscopic observation showed that all of the GAL-ir fibers were unmyelinated. These findings suggest that GAL-containing nerve fibers in the PDL may play an important role in the response of the tissue to experimental tooth movement.

Analysis of Variance↗
PubMed2001

Gyration radius of a circular polymer under a topological constraint with excluded volume.

It is nontrivial whether the average size of a ring polymer should become smaller or larger under a topological constraint. Making use of some knot invariants, we numerically evaluate the mean-square radius of gyration for ring polymers having a fixed knot type, where the ring polymers are given by self-avoiding polygons consisting of freely jointed hard cylinders. We obtain plots of the gyration radius versus the number of polygonal nodes for the trivial, trefoil, and figure-eight knots. We discuss possible asymptotic behaviors of the gyration radius under the topological constraint. In the asymptotic limit, the size of a ring polymer with a given knot is larger than that of no topological constraint when the polymer is thin, and the effective expansion becomes weak when the polymer is thick enough.

Journal Article↗
PubMed2001

Reciprocal expression of CD38 and CD34 by adult murine hematopoietic stem cells.

The effects of activation of adult murine stem cells on their expression of CD38 were studied using a murine transplantation model. First, the published finding that the majority of long-term engrafting cells from normal adult steady-state marrow are CD38(+) was confirmed. Next, it was determined that the majority of stem cells activated in vivo by injection of 5-fluorouracil (5-FU) or mobilized by granulocyte colony-stimulating factor are CD38(-). Stem cells that were activated in culture with interleukin-11 and steel factor were also CD38(-). Previous studies have shown that expression of CD34 by adult stem cells is also modulated by in vivo or in vitro activation. To determine whether there is reciprocal expression of CD38 and CD34, 4 populations of post-5-FU marrow cells were analyzed. The majority of the stem cells were in the CD38(-)CD34(+) fraction. However, secondary transplantation experiments indicated that when the bone marrow reaches steady state, the majority of the stem cells become CD38(+)CD34(-). In addition, the minority populations of CD34(+) stem cells that occur in steady-state bone marrow are CD38(-). This reversible and reciprocal expression of CD38 and CD34 by murine stem cells may have implications for the phenotypes of human stem cells.

ADP-ribosyl Cyclase↗
PubMed2001

Temporal changes in the distribution and number of macrophage-lineage cells in the periodontal membrane of the rat molar in response to experimental tooth movement.

In order to evaluate the possible role of macrophages in the remodelling of periodontal tissue in response to tooth movement, temporal changes in the number and distribution of macrophage-lineage cells in the periodontal membrane of the rat molar tooth after experimental tooth movement were examined immunohistochemically using four anti-rat monoclonal antibodies: ED1 (anti-monocyte/macrophage-lineage cells and dendritic cells), ED2 (anti-resident macrophages), KI-M2R (anti-tissue macrophages), and OX6 (anti-class II molecules). The right maxillary first molar tooth of Wistar rats was moved mesially by a closed-coil spring for 1, 3, 5, or 7 days. Sham-treated rats wearing an inactivated appliance for each experimental period and entirely untreated rats were used as controls. Alternate horizontal serial cryostat sections were cut and incubated with antibodies to ED1, ED2, KI-M2R, and OX6. In addition, cells immunopositive for each monoclonal antibody in the periodontal membrane during tooth movement were analysed on the tension and pressure sides. In the control rats, large numbers of cells positively stained with each monoclonal antibody were distributed throughout the periodontal membrane surrounding the distobuccal root. At 1 day after experimental tooth movement, the number of immunopositive cells obtained with all four monoclonal antibodies decreased as compared with those of the control on the mesial/pressure side. During the later experimental time periods, ED1- and OX6-positive cells in the periodontal membrane of this side were significantly increased in number compared with controls, whereas the density and distribution pattern of cells positive with ED2 or KI-M2R remained unchanged. On the mesial/pressure side, which underwent hyalinization, a marked accumulation of OX6- and ED1-reactive cells, but not of ED2- or KI-M2R-reactive cells, was frequently observed in the area of the hyalinized tissue at 5-7 days after the start of tooth movement. On the distal/tension side, no particular change in the distribution of immunopositive cells obtained with any antibody was detected throughout the experimental periods, with the exception that there was a significant increase in the number of ED1-positive cells and in of OX6-positive cells at 1 and 7 days, respectively, after the start of tooth movement. These results suggest that after the start of tooth movement OX6- and ED1-positive cells, which are mostly exudative macrophages, but not ED2- and KI-M2R-positive cells, i.e., resident macrophages, may be actively engaged in bone resorption and the remodelling of tissues on the pressure side of the periodontal membrane.

Animals↗
PubMed2001

Pathologic significance of Staphylococcus saprophyticus in complicated urinary tract infections.

OBJECTIVES: To determine the pathologic significance of Staphylococcus saprophyticus in complicated urinary tract infections. METHODS: We performed a retrospective analysis of specimens demonstrating this organism based on a survey of 9980 urine specimens cultured in our clinic during an 11-year period. Forty-two specimens from 34 patients were positive for S. saprophyticus. RESULTS: S. saprophyticus was isolated in 13 women without underlying urologic disease, and their symptoms were compatible with acute cystitis or acute pyelonephritis. S. saprophyticus was isolated from 7 men and 14 women with underlying urologic disease. In most of these 21 patients, S. saprophyticus was thought not to be a true uropathogen but rather a colonizer, because the isolated organism was usually low in numbers and found with a low degree of pyuria, and the hosts were usually asymptomatic. However, 2 patients demonstrating S. saprophyticus colonization developed sepsis after urologic surgery. CONCLUSIONS: Although this organism is pathogenic in certain circumstances, suggesting the necessity of preoperative antimicrobial elimination, it is usually a colonizer in complicated urinary tract infections.

Adult↗
PubMed2001

In vivo selection of Pseudomonas Aeruginosa with decreased susceptibilities to fluoroquinolones during fluoroquinolone treatment of urinary tract infection.

OBJECTIVES: To present a case of fluoroquinolone treatment failure in urinary tract infection caused by Pseudomonas aeruginosa, accompanied by in vivo selection of the post-treatment isolate that showed decreased susceptibilities to fluoroquinolones, and to report fluoroquinolone resistance mechanisms in the post-treatment isolate. METHODS: A patient with urinary tract infection was treated with a suboptimal dose of a fluorinated quinolone, gatifloxacin. P. aeruginosa strains were isolated before and after fluoroquinolone treatment. The pretreatment and post-treatment isolates were examined for relatedness by arbitrarily primed polymerase chain reaction. For these isolates, the minimum inhibitory concentration of antimicrobial agents was determined and mutations in the target genes (gyrA and parC) and regulatory genes (mexR and nfxB) for drug efflux pumps were analyzed. RESULTS: Failure of fluoroquinolone treatment of urinary tract infection was observed. The post-treatment isolate, which was assumed to be isogenic to the pretreatment isolate, exhibited fourfold to 16-fold increases in the MIC of fluoroquinolones. In this isolate, a new mutation, not observed in the pretreatment isolate, was found only in the gyrA gene, resulting in an amino acid change of aspartic acid to asparagine in codon 87 of GyrA. CONCLUSIONS: The P. aeruginosa isolate that was initially susceptible to fluoroquinolones showed decreased susceptibility to fluoroquinolones after treatment with a suboptimal dose of one fluoroquinolone. In the post-treatment isolate, the alteration of GyrA would be responsible for the decreased susceptibility to fluoroquinolones. We should be aware that inappropriate use of fluoroquinolones could select such a strain harboring a quinolone resistance-associated alteration of DNA gyrase.

Aged↗
PubMed2001

Morphology of the temporomandibular joint in skeletal class iii symmetrical and asymmetrical cases: a study by cephalometric laminography.

The aetiology of asymmetric growth in the mandible is not well understood. Previous studies have indicated that the functional lateral shift of the mandible in the period of prepubertal growth may translate to a true skeletal asymmetry, exclusively in skeletal Class III malocclusion. This asymmetry develops more characteristic features during the pubertal and post-pubertal growth periods. Early correction of a functional lateral shift of the mandible is recommended. The purpose of this study was to examine the relationship between the morphology of the temporomandibular joints and asymmetry in skeletal Class III malocclusion in adult female patients. Cephalometric and laminographic findings in 36 asymmetric skeletal Class III patients with a lateral shift of mandible (group 3) were compared to those of 25 symmetric skeletal Class I patients (group 1) and the same number of symmetric skeletal Class III malocclusions (group 2). All the patients had received no orthodontic treatment. The results showed that the TMJ of the side to which the mandible shifted showed a significantly narrower and shorter shape of the condyle head, smaller superior condylar space, and steeper eminence than those of the unshifted side.

Adolescent↗
PubMed2001

Craniofacial morphology of Japanese girls with Class II division 1 malocclusion.

OBJECTIVE: To identify the craniofacial features of Japanese girls with Class II division 1 malocclusions. METHOD: One hundred and ninety lateral cephalometric radiographs were analysed, and the subjects whose age ranged from 7 years 6 months to 15 years 10 months were divided into three groups by their dentition: middle mixed dentition, late mixed dentition, and early permanent dentition. The mean values of 5 linear and 16 angular cephalometric parameters were compared with established Japanese Class I control values. RESULTS: Japanese girls with Class II division 1 malocclusion had a significantly small S-N-B angle (p < 0.001), short mandibular ramus (p < 0.05-0.001), and a large mandibular plane angle (p < 0.05-0.001). CONCLUSION: Japanese girls with Class II division 1 malocclusion had a high-angle facial pattern associated with the short mandibular ramus.

Adolescent↗
PubMed2001

Association of Mycoplasma genitalium persistence in the urethra with recurrence of nongonococcal urethritis.

BACKGROUND: Most patients with recurrent symptomatic nongonococcal urethritis receive negative test results for Chlamydia trachomatis and Ureaplasma urealyticum, and the cause of such recurrence usually is unknown. GOAL: To assess the association of Mycoplasma genitalium with recurrent nongonococcal urethritis. STUDY DESIGN: In this study, 72 men with nongonococcal urethritis were treated with levofloxacin. Before and after treatment, symptoms and signs were assessed and first-pass urine was examined for C trachomatis, M genitalium, U urealyticum, and Mycoplasma hominis by polymerase chain reaction-based assays. RESULTS: In 6 of 45 men who had no symptoms and no evidence of inflammation after treatment, nongonococcal urethritis recurred. Of these 6 men, 5 had positive test results for M genitalium before levofloxacin treatment, which remained positive afterward. After the second treatment for recurrent nongonococcal urethritis, one man was still had a positive test result for the mycoplasma and experienced a subsequent recurrence. CONCLUSIONS: This study suggests that the persistence of M genitalium in the urethra may be associated with recurrence of nongonococcal urethritis.

Adolescent↗