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Biomedical subjects

K Tanimoto

Publications and source records attributed to K Tanimoto.

At least 19 recordsLinked to original sources
PubMed2006

Computer-aided system for measuring the mandibular cortical width on dental panoramic radiographs in identifying postmenopausal women with low bone mineral density.

INTRODUCTION: Mandibular inferior cortical width manually measured on dental panoramic radiographs may be useful for identifying postmenopausal women with low skeletal bone mineral density (BMD). Automatic measurement of cortical width may enable us to identify a large number of postmenopausal women with suspected low skeletal BMD. The purposes of this study were to develop a computer-aided system for measuring mandibular cortical width on dental panoramic radiographs and clarify the diagnostic efficacy of this system. METHODS: Panoramic radiographs of 100 postmenopausal women who had had BMD assessments of the lumbar spine and the femoral neck were used in this study. Experienced oral radiologist determined the position of the mental foramen on 100 digitized dental panoramic radiographs. After determination of the mental foramen, mandibular cortical width below the mental foramen was measured automatically with a computer-aided system by identifying the area of interest, enhancing the original image, determining inner and outer margins of the cortex, and selecting an appropriate point. Cortical width measured by this system was compared with BMD of the lumbar spine and the femoral neck. RESULTS: There were statistically significant correlation between cortical width measured by the computer-aided system and spinal BMD (r=0.50) and femoral neck BMD (r=0.54). These correlations were similar with those between cortical width by manual measurement and skeletal BMD. Sensitivity and specificity for identifying postmenopausal women with low spinal BMD by the computer-aided system were about 88.0% and about 58.7%, respectively. Those for identifying postmenopausal women with low femoral neck BMD by this system were about 87.5% and about 56.3%, respectively. CONCLUSION: Our results suggest that our computer-aided system may be useful for identifying postmenopausal women with low skeletal BMD.

Aged↗
PubMed2006

Bone marrow transplantation from unrelated donors for patients with adult T-cell leukaemia/lymphoma.

Adult T-cell leukaemia/lymphoma (ATLL) is a highly aggressive haematological malignancy. More than 40 cases of ATLL treated by allogeneic bone marrow transplantation (BMT) from sibling donors have been reported, while there have been only a few cases of unrelated BMT for treatment of this disease. We began performing allogeneic BMT from unrelated donors in 1999 to improve the outcome of ATLL patients with no suitable sibling donors. Eight ATLL patients underwent unrelated BMT; five received the conventional conditioning regimen consisting of cyclophosphamide and total body irradiation, while three received a reduced-intensity preparative regimen. Two patients died due to encephalopathy of unknown aetiology on days 10 and 35, and one patient died due to progression of ATLL 25 months after BMT. Five patients are currently alive and disease-free at a median of 20 months after BMT. Proviral human T-lymphotropic virus type-I (HTLV-I) DNA load in peripheral blood mononuclear cells (PBMCs) was assessed in four cases before and after BMT. HTLV-I proviral DNA load was reduced significantly after transplantation. Unrelated BMT is feasible for treatment of ATLL. Further studies in a larger number of cases are required to determine the optimal conditioning regimen and stem cell source.

Bone Marrow Transplantation↗
PubMed2006

Diagnostic performance of general dental practitioners after lecture in identifying post-menopausal women with low bone mineral density by panoramic radiographs.

OBJECTIVES: Mandibular cortical erosion detected on panoramic radiographs may be useful for identifying post-menopausal women with low skeletal bone mineral density (BMD). The purposes of this study were to calculate the diagnostic performance of general dental practitioners (GDPs) who attended a lecture on identifying post-menopausal women with low BMD from findings on panoramic radiographs and to evaluate the influence of GDPs' age on diagnostic performance. METHODS: After a 1 h lecture, 111 GDPs were asked to classify the mandibular cortex (normal or eroded) on panoramic radiographs obtained from 100 post-menopausal women who have had skeletal BMD assessment. Low BMD was defined as a BMD T score of -1.0 or less. Diagnostic performance was analysed by comparing two groups classified by mandibular cortex (women with normal cortex and women with any eroded cortex) with those classified by BMD (women with normal BMD and women with low BMD). RESULTS: The mean sensitivity, specificity, positive predictive value, negative predictive value, accuracy and likelihood ratio for a positive risk result were 73.0% (95% confidence interval [CI]; 71.3 to 74.7%), 49.0% (95% CI; 46.4 to 51.5%), 66.9% (95% CI; 66.0 to 67.8%), 57.0% (95% CI; 55.8 to 58.2%), 62.9% (95% CI; 62.1 to 63.7%) and 1.51 (95% CI; 1.44 to 1.58), respectively. GDPs' age did not influence diagnostic performance. CONCLUSIONS: Our results suggest that 73.0% of women who had low skeletal BMD can be identified by GDPs after a lecture on the use of panoramic radiographs as an aid in diagnosing low BMD; however, the diagnostic performance may not be influenced by GDPs' age.

Adult↗
PubMed2005

Naturally arising CD4+CD25+ regulatory T cells suppress the expansion of colitogenic CD4+CD44highCD62L- effector memory T cells.

Naturally arising CD4+CD25+ regulatory T (T(R)) cells have been shown to prevent and cure murine T cell-mediated colitis. However, their exact mechanism of controlling colitogenic memory CD4+ T cells in in vivo systems excluding the initial process of naive T cell activation and differentiation has not been examined to date. Using the colitogenic effector memory (T(EM)) CD4+ cell-mediated colitis model induced by adoptive transfer of colitogenic CD4+CD44(high)CD62L(-) lamina propria (LP) T cells obtained from colitic CD4+CD45RB(high) T cell-transferred mice, we have shown in the present study that CD4+CD25+ T(R) cells are able not only to suppress the development of colitis, Th1 cytokine production, and the expansion of colitogenic LP CD4+ T(EM) cells but also to expand these cells by themselves extensively in vivo. An in vitro coculture assay revealed that CD4+CD25+ T(R) cells proliferated in the presence of IL-2-producing colitogenic LP CD4+ T(EM) cells at the early time point (48 h after culture), followed by the acquisition of suppressive activity at the late time point (96 h after culture). Collectively, these data suggest the distinct timing of the IL-2-dependent expansion of CD4+CD25+ T(R) cells and the their suppressive activity on colitogenic LP CD4+ T(EM) cells.

Adoptive Transfer↗
PubMed2005

Long-term follow-up results of no initial therapy for ocular adnexal MALT lymphoma.

BACKGROUND: The majority of lymphomas in the ocular adnexa are low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma). Although radiotherapy is the most frequently applied management, cataract and dry eye are problematic complications. PATIENTS AND METHODS: Between 1973 and 2003, the clinical features of 36 patients with ocular adnexal MALT lymphoma with no symptoms who were managed with no initial therapy after biopsy or surgical resection were retrospectively analyzed. RESULTS: The median patient age was 63 years (range 22-84) and all patients had stage I disease, consisting of 31 unilateral cases and five bilateral cases. With a median follow-up of 7.1 years, 25 (69%) did not require treatment. The median time until the initiation of treatment in the remaining 11 patients (31%) was 4.8 years. Six patients (17%) died, and among them only two (6%) died due to progressive lymphoma. Seventeen patients (47%) progressed, but histologic transformation was recognized in only one (3%). The estimated overall survival rates of the 36 patients after 5, 10 and 15 years were 94%, 94% and 71%, respectively. CONCLUSIONS: In selected patients with ocular adnexal MALT lymphoma, no initial therapy might be an acceptable approach, because 70% of patients remained untreated at a median of 8.6 years, and their survival was comparable to that of reports on immediate therapy.

Adult↗
PubMed2005

The metabolism of hyaluronan in cultured rabbit growth plate chondrocytes during differentiation.

Hyaluronan (HA) is one of the major extracellular matrix components in cartilage. In addition to the biomechanical functions, HA has various important roles in the differentiation of chondrocytes. The purpose of this study was to clarify the nature of HA synthesis during chondrocyte differentiation. Growth plate chondrocytes were isolated from rabbit ribs and cultured in chondrocyte differentiation medium. The amount of HA and HA synthase (HAS) mRNA levels were analyzed for each stage of chondrocyte differentiation by means of high-performance liquid chromatography (HPLC) and real-time PCR, respectively. The distribution of HA in cultured chondrocytes was observed by histochemical staining. The amount of HA, ranging widely in size, was increased substantially during the hypertrophic stage. The expression levels of HAS2 and HAS3 mRNAs were low during the matrix-forming stage. HAS2 mRNA level was substantially enhanced at the pre-hypertrophic stage, whereas HAS3 mRNA level exhibited a slight increase. HAS1 mRNA was not detected. The intensity of HA staining was high around the hypertrophic chondrocytes. These results suggest that HA metabolism in chondrocyte differentiation is regulated by the selective expression of HASs, and HAS2 and the related large size-HA may have a certain association with the hypertrophic changes of chondrocytes.

Animals↗
PubMed2005

A vancomycin-dependent VanA-type Enterococcus faecalis strain isolated in Japan from chicken imported from China.

AIMS: The characterization of KC122.1, which is a vancomycin-dependent VRE (Vancomycin-resistant enterococci) (Enterococcus faecalis) and the first case in Japan of a VRE isolate obtained from chicken meat imported from China. METHODS AND RESULTS: PCR amplification of vanA, vanS and ddl gene and direct sequencing of the PCR products were performed. KC122.1 was a VanA-type VRE showing high-level vancomycin resistance and low-level teicoplanin resistance, and its vanS gene had three point mutations. The ddl gene of KC122.1 was sequenced and two changes were found at the ninth codon (GCC-GAC) and the stop codon (TAA-CAA). The latter change was also found in the laboratory strain E. faecalis FA2-2. CONCLUSIONS: Three point mutations in vanS resulted in high-level vancomycin resistance and low-level teicoplanin resistance. The change at the ninth codon resulted in the inactivation of the ddl gene and vancomycin-dependent growth. An eight amino acid extension at the C-terminal did not impair the function of the D-Ala : D-Ala ligase. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first example of the isolation of VRE from chicken meat imported from China and the first vancomycin-dependent VRE from a nonhuman source.

Animals↗
PubMed2005

Genetic contribution of the tumour necrosis factor (TNF) B + 252*2/2 genotype, but not the TNFa,b microsatellite alleles, to systemic lupus erythematosus in Japanese patients.

The contribution of the tumour necrosis factor (TNF) B + 252 (TNFB) dimorphism and microsatellite polymorphisms of TNFa and TNFb to the pathogenesis of systemic lupus erythematosus (SLE) was studied in Japanese patients. The TNFB dimorphism was determined using the restriction fragment length polymorphism (RFLP) method with NcoI digestion followed by specific polymerase chain reaction (PCR) amplification. TNFa and TNFb microsatellite polymorphisms were determined using the DNA sequencer and GeneScan program (Applera Corporation, Foster City, CA) followed by specific PCR amplification. HLA-DRB1*15 typing was carried out by the PCR-sequence specific conformational polymorphism (SSCP) method. In SLE, the allele frequency of TNFB*2 significantly increased (68.9%, P < 0.05) and the genotype frequency of TNFB*2/2 also increased (52.8%, P < 0.05). TNFB*2 showed no significant linkage disequilibrium with HLA-DRB1*1501. The prevalence of TNFa13 and TNFb4 showed very slight increases, but these increases were not significant. An association analysis indicated that TNFB*2/2 conferred greater, or at least equal, susceptibility to SLE in Japanese patients in comparison with HLA-DRB1*1501. The TNFB*2/2 genotype may contribute additively with DRB1*1501 to SLE in Japanese patients. No association was observed between auto-antibodies and TNF. TNFB*2 is a genetic marker for SLE in Japanese patients, while TNFa and TNFb microsatellites are not associated with SLE.

Alleles↗
PubMed2005

Cyclic mechanical strain regulates the PTHrP expression in cultured chondrocytes via activation of the Ca2+ channel.

The association between mechanical stimulation and chondrocyte homeostasis has been reported. However, the participation of PTHrP (parathyroid-hormone-related protein) in the mechano-regulation of chondrocyte metabolism remains unclear. We determined whether mechanical stimulation of chondrocytes induces the expression of PTHrP and, further, whether the mechano-modulation of PTHrP is dependent on the maturational status of chondrocytes. Cyclic mechanical strain was applied to rat growth plate chondrocytes at the proliferating, matrix-forming, and hypertrophic stages at 30 cycles/min. Cyclic mechanical strain significantly increased PTHrP mRNA levels in chondrocytes at the proliferating and matrix-forming stages only. The induction of PTHrP was dependent on loading magnitude at the proliferating stage. Using specific ion channel blockers, we determined that mechano-induction of PTHrP was inhibited by nifedipine, a Ca2+ channel blocker. These results suggest that mechanical induction of PTHrP possibly provides the environment for greater chondrocyte replication and matrix formation that would subsequently affect cartilage formation.

Animals↗
PubMed2005

Metastatic retinoblastoma of the maxilla and mandible.

Metastatic retinoblastoma of the jaws is very rare. We present a 4-year-old boy with metastatic retinoblastoma that involved both the maxilla and mandible simultaneously. Enhanced CT indicated bone-destructive masses with partially non-enhanced area and enhanced margin in the right maxilla and left mandible. MRI showed well-delineated masses that were isointense on T(1) weighted images and hyperintense on T(2) weighted images. Four weeks after chemotherapy and bone marrow transplantation, the size of lesions remarkably decreased. The patient died 19 months later with extensive tumour metastases despite additional chemotherapy. In this case, the dental crypt of a permanent tooth was considered the potential target through which retinoblastoma metastasized to the jaws.

Child, Preschool↗
PubMed2004

Recommendation of modified classification for odontogenic carcinomas.

Primary squamous cell carcinoma (SCC) derived from odontogenic epithelium is diagnosed as primary intraosseous carcinoma (PIOC). The term "intraosseous" means the bone marrow spaces. Odontogenic cells, however, exist not only in the bone marrow space but also in the periodontal space and the subepithelial soft tissue space. In our survey for 36 SCC lesions of odontogenic origin, many lesions involved two or all of the three spaces. There was only one lesion which involved the bone marrow space alone. In some cases, the extent of the early lesions was restricted around the tooth or at a part of the alveolar crest. The possibility of a SCC of odontogenic origin arising in the periodontal and the subepithelial soft tissue spaces was suggested. We proposed the term "Odontogenic SCC" to replace "PIOC".

Carcinoma↗
PubMed2004

Utility of urinary pyridinoline and deoxypyridinoline ratio for diagnosis of osteoarthritis at temporomandibular joint.

BACKGROUND: Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) collagen cross-links are known markers of bone and cartilage turnover that are found in urine in various diseases. The present study was designed to quantify Pyr and Dpyr levels in urine of patients with osteoarthritis (OA) of the temporomandibular joint (TMJ), and to evaluate whether their concentrations are related to specific pathologic findings in the TMJ. METHODS: Urine samples were obtained from 12 patients with OA of the TMJ and 16 asymptomatic controls, and following appropriate preparation, analyzed by high-performance liquid chromatography (HPLC) and fluorescence spectroscopy for Pyr and Dpyr. RESULTS: The urinary concentration of Pyr and the Pyr to Dpyr (Pyr/Dpyr) ratio were significantly higher (P < 0.05) in OA patients than in the controls (182.2 +/- 86.5 pmol/ml vs. 115.6 +/- 27.9 pmol/ml and 4.00 +/- 1.53 pmol/ml vs. 2.86 +/- 0.97 pmol/ml, respectively). However, the Pyr/Dpyr ratio was not associated with any specific clinical or radiographic findings. CONCLUSION: These findings suggest that the level of Pyr and the Pyr/Dpyr ratio in urine may be a useful diagnostic indicator for intra-articular pathologic changes during TMJ OA.

Adult↗
PubMed2004

Effects of TGF-beta on hyaluronan anabolism in fibroblasts derived from the synovial membrane of the rabbit temporomandibular joint.

Hyaluronan (HA) synthesis in the synovial membrane is affected by various chemical mediators. It is hypothesized that transforming growth factor-beta 1 (TGF-beta 1) would be a mediator to modulate HA synthesis in cultured synovial membrane fibroblasts of the temporomandibular joint (TMJ). Fibroblasts were extracted from the TMJ synovial membrane of four-week-old Japanese white rabbits. The amount of HA and expression levels of HA synthase (HAS) mRNAs induced by TGF-beta 1 treatment were analyzed by means of high-performance liquid chromatography and real-time polymerase chain-reaction, respectively. Both medium and large amounts of HA were enhanced by the stimulation of TGF-beta 1. HAS2 mRNA expression was enhanced 13-fold after six-hour stimulation with TGF-beta 1 (10 ng/mL), whereas HAS3 mRNA expression was not changed significantly. These results suggest that TGF-beta 1 enhances the expression of HAS2 mRNA in the TMJ synovial membrane fibroblasts and may contribute to the production of high-molecular-weight HA in the joint fluid.

Animals↗
PubMed2003

Diagnostic points and possible origin of osteomyelitis in synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome: a radiographic study of 77 mandibular osteomyelitis cases.

OBJECTIVES: To find diagnostic points and to identify the origin of osteomyelitis in synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome. METHODS: Fifty-two patients with mandibular suppurative osteomyelitis and 25 patients with mandibular osteomyelitis in SAPHO syndrome were included in the study. Radiographic patterns of the lesion, types of periosteal reaction and the presence of external bone resorption and bone enlargement were investigated in each case and compared between the two entities. RESULTS: Suppurative osteomyelitis demonstrated an osteolytic pattern and a lamellated type of periosteal reaction, whereas SAPHO syndrome revealed a mixed-pattern, solid-type periosteal reaction, external bone resorption and bone enlargement. CONCLUSIONS: Radiographic examination is suggested to be convenient and a useful diagnostic method of differentiating osteomyelitis in SAPHO syndrome from suppurative osteomyelitis. The periosteum is suspected to be the original site of osteomyelitic lesions in SAPHO syndrome.

Acquired Hyperostosis Syndrome↗
PubMed2003

Mechanical stimuli enhances the expression of RGD-CAP/betaig-h3 in the periodontal ligament.

RGD-CAP, a member of the fasciclin family, is expressed in the periodontal ligament (PDL). Since the PDL is continually subjected to mechanical forces from such orofacial functions as mastication, biting, speech and swallowing, the mechanical stimuli is thought to be associated with the expression of RGD-CAP. Furthermore, the adhesive functions of RGD-CAP may contribute to the maintenance or regeneration of PDL architecture. The objective of this study was to examine whether mechanical stimuli modulate the expression of RGD-CAP in the human PDL, and to examine the effects of recombinant RGD-CAP on the adhesion of PDL cells. During experimental tooth movement, the expression of RGD-CAP was significantly enhanced in the PDL. In vitro experiments with cultured PDL cells showed that the expression of RGD-CAP mRNA was significantly enhanced by mechanical tensile force of 15.4kPa for 48h. The induction of RGD-CAP mRNA, meanwhile, was completely inhibited by cycloheximide which is an inhibitor of protein synthesis. Furthermore, neutralising antibody against TGF-beta also suppressed the mechanical induction of RGD-CAP. The adhesion of cultured PDL cells onto plates coated with recombinant RGD-CAP increased significantly compared with the controls. These findings suggest that RGD-CAP, induced by TGF-beta expressed in response to mechanical stimuli, plays an important role in modulating the homeostasis of PDL.

Blotting, Western↗
PubMed2003

Association between craniofacial growth and urinary bone metabolic markers (pyridinoline, deoxypyridinoline) in growing rats.

Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are intermolecular cross-links of mature collagen and reflect the bone turnover. The purpose of this study was to elucidate the association between craniofacial growth and urinary Pyr and Dpyr levels. Lateral cephalograms and 24-hour urine were taken for 7 male rats from 5 to 20 wks old. The urinary Pyr and Dpyr were quantified by high-performance liquid chromatography. The neurocranium and upper viscerocranium exhibited significant increases in size, with the maximum rate at around 6 wks old. The mandible presented more substantial growth, with the maximum change at 8 wks old. The urinary Pyr and Dpyr levels gradually increased and reached the maximum at 8 wks old. No prominent association was found between neurocranial growth and urinary levels of pyridinium cross-links, whereas Pyr and Dpyr levels exhibited similar time-dependent metabolic changes to mandibular growth. In conclusion, it is shown that urinary pyridinium cross-links may be useful for the prediction of mandibular growth.

Age Factors↗
PubMed2003

Detection of vascular disease risk in women by panoramic radiography.

Low bone mineral density and rapid bone loss of the skeleton are associated with mortality risk from vascular diseases in post-menopausal women. Panoramic radiographic measurements are considered as indicators of skeletal bone mineral density or bone turnover. We hypothesize that such measurements may be associated with vascular disease risk in post-menopausal women. Associations of mandibular cortical shape and width on panoramic radiographs with skeletal bone mineral density and risk factors related to vascular diseases were investigated in 87 post-menopausal women. Cortical shape was associated with skeletal bone mineral density, low-density lipoprotein cholesterol, apolipoprotein B, resting heart rate, and endothelial dysfunction. Cortical width was associated with skeletal bone mineral density, low-density lipoprotein cholesterol, and apolipoprotein A1. Dentists may be able to refer women with increased risk of vascular diseases, as well as low bone mineral density, to medical professionals for further examination by panoramic findings.

Absorptiometry, Photon↗