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K Ihara

Publications and source records attributed to K Ihara.

At least 19 recordsLinked to original sources
PubMed2007

Low-grade central osteosarcoma mimicking fibrous dysplasia: a report of two cases.

Low-grade central osteosarcoma is an unusual variant of conventional osteosarcoma. We present here two rare cases of low-grade central osteosarcoma resembling fibrous dysplasia. A 24-year-old woman diagnosed as fibrous dysplasia was treated with intra-lesional excision and curettage of the tumor but tumor recurred at 4 months after surgery. Distal femoral en-bloc resection was performed followed by arthroplasty with mega-prosthesis of the knee. A 57-year-old man diagnosed as central osteosarcoma was treated with wide excision of the tumor, followed by reconstruction with the vascularized fibula graft combined with an autogenous irradiated bone graft. Because of the difficulty in distinguishing low-grade central osteosarcoma from a benign lesion, open biopsy is needed to obtain a large tumor sample. Careful clinical and pathological evaluation is required to obtain a definite diagnosis. The treatment of low-grade central osteosarcoma is en-block resection with wide surgical margins.

Adult↗
PubMed2006

A new navigation system based on cephalograms and dental casts for oral and maxillofacial surgery.

Intraoperative navigation systems help surgeons to accurately carry out preoperative plans without injuring anatomically important structures. A system is evaluated that uses cephalograms instead of computed tomographic (CT) scans to create images. Three-dimensional (3D) dental casts provide registration between imaging data and the patient. Cephalograms are widely employed in orthognathic and oral and maxillofacial surgery and expose patients to lower doses of radiation than CT. The system uses a dental cast to register the operation field to a pair of frontal and lateral cephalograms. The cast is transformed to 3D data with a laser scanner and a programme that runs on a personal computer. 3D data describing the dental cast, cephalograms and the oral and maxillofacial region of the patient are integrated with specialized software. The optical tracking system for navigation uses charged-coupled-device (CCD) video cameras and light-emitting diodes (LEDs). Two CCD video cameras follow the 3D coordinates of LED assemblies attached to the head, lower jaw and a handpiece. Errors occurring when a dental cast was transformed to 3D data ranged from 0.08 to 0.21 mm. Mean errors were 0.71 mm (0.21-1.09 mm) for the right maxillary central incisor, 0.62 mm (0.04-1.69 mm) for the right maxillary 2nd molar and 1.02 mm (0.23-1.47 mm) for the left maxillary 2nd molar. This surgical navigation system is sufficiently accurate for use in oral and maxillofacial surgery.

Humans↗
PubMed2006

Phenotypic and genetic analyses of T-cell-mediated immunoregulation in patients with Type 1 diabetes.

AIMS: To investigate the contribution of regulatory T cells and co-stimulatory molecules in CD4(+) T cells to the development of Type 1 diabetes (T1D). METHODS: Twelve patients with T1D, nine patients with systemic lupus erythematosus (SLE), and 12 age-matched healthy control subjects participated. We analysed the proportions of CD25(+)CD4(+) T cells and natural killer T cells (NKT cells), and the expression levels of Foxp3, CTLA-4, CD28, ICOS, PD-1 and BTLA in peripheral blood mononuclear cells and purified CD4(+) T cells. RESULTS: There were no significant differences in the proportions of CD25(+) CD4(+) T cells or NKT cells among the three groups. PD-1 expression levels of peripheral CD4(+) T cells from T1D patients were significantly lower than those from healthy control subjects (P = 0.00066). In contrast, PD-1 expression levels were similar in SLE patients and healthy control subjects. The expression levels of Foxp3, CTLA-4, CD28, ICOS and BTLA were similar in the three groups. CONCLUSIONS: Decreased expression of the PD-1 gene in CD4(+) T cells may contribute to the development and/or maintenance of autoimmune T1D. As the population studied was small and heterogeneous, further studies are required to confirm the findings.

Adolescent↗
PubMed2006

Association study of polymorphisms in SOCS family genes with type 1 diabetes mellitus.

Suppressors of cytokine signalling (SOCS) proteins play important roles in the negative regulation of cytokine signal. We first searched for polymorphisms in SOCS-1, SOCS-3 and SOCS-5 genes, and examined the association of the polymorphisms with type 1 diabetes (T1D). As a result, we did not find any significant associations between SOCS genes and T1D.

Case-Control Studies↗
PubMed2006

Persistent diffusion abnormalities in the brain stem of three children with mitochondrial diseases.

We report 2 children (patients 1 and 2) with Kearns-Sayre syndrome and 1 (patient 3) with Leigh syndrome, who underwent serial diffusion-weighted MR imaging (DWI) studies for 2.8 (patient 1), 4.2 (patient 2), and 1.0 years (patient 3). The DWI revealed the persistent hyperintense signals in the pontine and mesencephalic tegmenta. The apparent diffusion coefficient in the affected regions remained constantly low, suggesting that cytotoxic edema and spongiform degenerations may compose these brain stem lesions.

Basal Ganglia↗
PubMed2005

A case of hyperinsulinism/hyperammonaemia syndrome with reduced carbamoyl-phosphate synthetase-1 activity in liver: a pitfall in enzymatic diagnosis for hyperammonaemia.

We report a patient who was first diagnosed as having congenital carbamoyl-phosphate synthetase-1 (CPS-1) deficiency on the basis of significantly low CPS-1 activity in the liver at 1 year of age. We then started therapy against hyperammonaemia with little effect and, at the age of 15 years, we analysed the GLUD1 gene and found a previously reported gain-of-function mutation in the gene, resulting in a change of her diagnosis to hyperinsulinism/hyperammonaemia (HI/HA) syndrome. This case demonstrates that low CPS-1 activity in liver, however significant it might be, does not always come from a primary CPS-1 deficiency and that we have to take into consideration the possibility of a secondary CPS-1 deficiency, such as HI/HA syndrome.

Adolescent↗
PubMed2004

Femoral reconstruction by single, folded or double free vascularised fibular grafts.

We reviewed 17 patients for a mean of 25 months period after free vascularised fibular transfer to reconstruct massive bone defect or recalcitrant nonunion of the femur. There were 11 cases of posttraumatic nonunion and six patients had a large bony defect following resection of bone tumour. Ten patients underwent double or folded and seven patients underwent single vascularised fibula graft transfer. Mean bony defect of the femur was 6.5 cm and mean length of grafted fibula was 15 cm. Revision surgery due to postoperative vascular complications was required in five cases. Twenty-three out of 24 (96%) vascularised fibulas were transferred successfully. The resultant outcome was successful in 15 out of 16 (94%) patients with confirmed bone union. Stress fracture occurred in three inlay fibula grafts. Hypertrophic change of the fibula graft was significantly noted in inlay grafts as compared to onlay grafts. All patients could walk without brace at a mean of 11 months postoperatively. Donor-site morbidity was minimum. Vascularised fibula grafting is a reliable and safe reconstructive procedure for massive femur defects. Folded or double fibula grafts cannot prevent stress fractures and the key point is to rigidly stabilise the femur in an anatomically aligned position.

Adolescent↗
PubMed2004

Changes in coagulation condition, cytokine, adhesion molecule after repair of type A aortic dissection.

OBJECTIVE: Because residual dissection often exists even after the repair of a type A dissection, we evaluated coagulation conditions, cytokine levels, and adhesion molecule levels in mid-term follow up after repair of type A dissections. METHODS: Thrombin-antithrombin III complex (TAT), D-dimer, soluble interleukin-2 receptor (sIL-2R), soluble intercellular adhesion molecule (sICAM)-1, and type III procollagen peptide (PIIIP) were measured in 12 patients (mean age=63 years) following the repair of a type A aortic dissection at 6-82 months after repair (median=33 months). RESULTS: In the chronic phase, TAT and D-dimer were significantly higher in patients following the repair of a type A dissection compared to healthy controls (TAT; 12+/-8 vs. 2.5+/-1.2 ng/ml, P = 0.0001, D-dimer; 779+/-1384 vs. 104+/-46 U/ml, P = 0.0001). Cytokine was significantly higher in the affected patients (sIL-2R; 556+/-205 vs. 398+/-132 U/ml, P = 0.003, sICAM-1; 255+/-131 vs. 211+/-48 ng/ml, P = 0.136). Collagen turnover (PIIIP) showed a significantly higher value in the affected patients (0.80+/-0.32, vs. 0.58+/-0.13 U/ml, P = 0.002). sIL-2R, sICAM-1 and PIIIP showed a negative correlation with the follow-up period (sIL-2R; r = -0.733, P = 0.0067, sICAM-1; r = -0.61, P = 0.035, PIIIP; r = -0.692, P = 0.0126). We found a positive correlation between aortic size and TAT (r = 0.644, P = 0.0238, n = 12) as well as with D-dimer (r = -0.7831, P = 0.0106, n = 12) and TAT showed significantly higher values in the residual dissection group compared to those without residual dissection (16.6+/-7.9 vs. 7.45+/-4.75 ng/ml, P = 0.035). CONCLUSION: Hypercoagulation conditions continued even after repair. Both TAT and D-dimer would be good indices for following up patients having repaired aortic dissections. Furthermore, cytokine, adhesion molecules, and collagen turnover would return to a stable state unless impairment and expansion of the vessel wall occurred.

Adult↗
PubMed2003

Hypertrophy of vascularized bone isograft in rats treated with cyclosporine A.

The aim of this study was to investigate the effects of cyclosporine A (CsA) on vascularized tibio-fibula isograft between 12-week-old male Lewis rats. After transplantation, 45 rats were randomly allocated to one of the following 7 treatment groups: (1) 4-week vehicle (n = 5), (2) 4-week CsA (n = 5), (3) 8-week vehicle (n = 10), (4) 8-week CsA (n = 10), (5) 4-week CsA followed by 4-week vehicle (n = 5), (6) 16-week vehicle (n = 5), or (7) 4-week CsA followed by 12-week vehicle (n = 5). In soft X-ray and micro-computed tomography examination, hypertrophic change of the grafted bones was apparent in the 4- and 8-week CsA groups. Mineral apposition rate and bone formation rate of the grafted bones in the 4-week CsA group were markedly higher than those in the 4-week vehicle group. In the 4- and 8-week CsA groups, however, bone mineral density (BMD) of the grafted bones was lower and strength of the reconstructed bones was weaker than the 4- and 8-week vehicle groups. Urinary deoxypyridinoline (DPD) level was higher in the 4- and 8-week CsA groups than in the 4- and 8-week vehicle groups. The group of 4-week CsA followed by 4-week vehicle had a level of urinary DPD equal to the 8-week vehicle group, but their BMD of the grafted bones was lower and strength of the reconstructed bones was weaker than the 8-week vehicle group. By contrast, the group of 4-week CsA followed by 12-week vehicle had BMD of the grafted bones and strength of the reconstructed bones similar to the 16-week vehicle group. These findings demonstrate that short-term CsA treatment induces hypertrophic change of vascularized bone graft with high-turnover bone loss, and strength of the reconstructed bone is gradually restored after the cessation of CsA treatment.

Amino Acids↗
PubMed2003

Th1 and Th1-inducing cytokines in Salmonella infection.

Thl and Thl-inducing cytokines and T cell responses were investigated in human salmonellosis. Serum IFN-gamma, IL-12 and IL-18 levels were increased significantly in patients with salmonellosis. The increase in serum IL-15 and IL-18 levels was more significant and prolonged in patients with the systemic form of salmonellosis than in those with the gastroenteric form. The serum IFN-gamma level was correlated significantly with IL-12 and IL18 levels, and the IL-15 level was correlated significantly with IL-18. Upon stimulation with Salmonella in vitro, mononuclear cells from salmonellosis patients produced significantly higher amounts of IFN-gamma and IL-12 compared with those from healthy controls. Anti-IL-12 moAb or anti-IL18 MoAb significantly inhibited Salmonella-induced IFN-gamma production in vitro. gamma delta T cells expressed significantly higher levels of IFN-gamma mRNA in salmonellosis patients than in healthy controls. The results suggest that Th1-inducing cytokines appear to be involved in the in vivo response against Salmonella infection, promoting IFN-gamma production by alpha beta and gamma delta T cells which plays a protective role against Salmonella.

Adolescent↗
PubMed2002

Effects of cerivastatin on vascularized allogenic bone transplantation in rats treated with cyclosporine A.

The aim of the present study was to investigate the effects of oral cerivastatin (0.1 mg/kg/day) on vascularized allogenic transplanted bone that is treated with cyclosporine A (CsA) (10 mg/kg/day) and on vascularized isogenic transplanted bone that is not treated with CsA. Allogenic transplantation was performed on 12-week-old male DA rats with the major histocompatibility antigen (MHC) RT1a (as the donor) and age-matched male Lewis rats with MHC RT1l (as the recipient), and isogenic transplantation was performed on 12-week-old male Lewis rats. After transplantations, 20 rats (10 rats in each transplantation) were randomized into four groups to receive the following treatment for 16 weeks: (1) CsA plus cerivastatin vehicle or (2) CsA plus cerivastatin in the allogenic transplanted rats, and (3) CsA vehicle plus cerivastatin vehicle or (4) CsA vehicle plus cerivastatin in the isogenic transplanted rats. Bone biochemical markers, mineral density, and strength were measured at the end of the study period. Serum levels of osteocalcin (OC) and parathyroid hormone (PTH) and urinary deoxypyridinoline (DPD) level were higher in the allogenic transplanted rats than in the isogenic transplanted rats. In the allogenic transplanted rats, the cerivastatin treatment decreased urinary DPD levels, but not serum OC nor PTH levels. Furthermore, the cerivastatin treatment improved bone mineral density of the allogenic transplanted bones and bone strength of the allogenic reconstructed bones. In contrast, no effect of the cerivastatin treatment was observed in the isogenic transplanted rats. These results suggest that the cerivastatin treatment improves CsA-induced high-turnover osteopenia mainly through the inhibition of bone resorption.

Amino Acids↗
PubMed2002

Effects of vitamin D analog, 22-oxa-1,25-dihydroxyvitamin D(3), on bone reconstruction by vascularized bone allograft.

We previously reported that vascularized bone allograft using immunosuppressants, such as cyclosporine A (CsA), is one approach for reconstruction of large bone defects in both experimental animals (Microsurgery 15:663; 1994) and clinically in humans (Lancet 347:970, 1996). Because immunosuppressive agents such as CsA induce significant side effects, including bone loss, other therapeutic agents supporting successful vascularized bone allografts have been sought after. We investigated the effects of 22-oxa-1,25-dihydroxyvitamin D(3) (OCT) on vascularized bone allograft, and compared its effects with CsA. Twelve-week-old DA rats with the major histocompatibility antigen (MHC) RT-1(a) were used as donors and age-matched Lewis rats with MHC RT-1(l) used as recipients. Allografted bones in rats treated with vehicle were rejected completely. Soft X-ray examination demonstrated that administration of OCT (0.5 microg/kg per day) for 12 weeks after bone graft induced bone union as effective as treatment for 12 weeks with CsA (10 mg/kg per day). Transplanted bones in OCT-treated rats showed higher bone mineral density than that in CsA-treated rats. Histologically, transplanted bones in OCT-treated rats at 12 weeks were nonvital, but these bones united with recipient vital bones. After cessation of 12 week treatment with OCT, new bone formation occurred around the grafted nonvital bones during a 9 month period. Transplanted bones in CsA-treated rats were vital and formed union with recipient bones, whereas cortical bones became thin when compared with nonvital bones in OCT-treated rats. Urinary deoxypyridinoline levels in rats treated with CsA were significantly higher than levels in rats treated with OCT, suggesting accelerated bone resorption in CsA-treated rats. These results suggest that OCT exerts an anabolic action on bone reconstruction by allogeneic bone transplantation.

Amino Acids↗
PubMed2002

Polymorphisms of transforming growth factor-beta1 and transforming growth factor-beta1 type II receptor genes are associated with acute graft-versus-host disease in children with HLA-matched sibling bone marrow transplantation.

The aim of this study was to determine whether the gene polymorphisms of Th1/Th2 and immunoregulatory cytokines were associated with aGVHD in Japanese children receiving allogeneic bone marrow transplantation (allo BMT). We investigated polymorphisms of genes encoding interleukin (IL)-4, IL-4 receptor (IL-4 R), IL-10, transforming growth factor (TGF)-beta1, TGF-beta1 type II receptor (TGF-beta1 RII), interferon (IFN)-gamma, IFN-gamma type 2 receptor (IFN-gamma R2), and IFN regulatory factor (IRF)-1. Sixty-seven patients were treated with allo BMT from HLA-identical siblings, and aGVHD was observed in 38. TGF-beta1 codon 10 leucine (Leu) /proline (Pro) polymorphism in donors was associated with the development of aGVHD. Patients having donors with the Pro allele had aGVHD more frequently than those without Pro allele (30/45 vs 8/20, odds ratio = 3.00; P = 0.04). TGF-beta1 RII 1167 C/T polymorphism in recipients was also associated with the development of aGVHD. The incidence was significantly higher in recipients with T allele than in those without T allele (21/27 vs 16/35, odds ratio = 4.16; P = 0.01). In conclusion, genetic backgrounds of TGF-beta1 and TGF-beta1 RII may be involved in the development of aGVHD in HLA-matched sibling BMT in Japanese children.

Acute Disease↗
PubMed2002

Association study between CD30 and CD30 ligand genes and type 1 diabetes in the Japanese population.

CD30-CD30 ligand (CD30L) signal transduction appears to protect against autoimmune diabetes by preventing expansion of autoreactive T cells and suppressing Th1-cytokine response. The purpose of this study was to determine whether CD30 or CD30L genes serve as a novel susceptibility gene for type 1 diabetes in humans. We screened CD30 and CD30L genes for polymorphisms in Japanese patients with type 1 diabetes and control subjects. Then, association studies were performed between each of the identified polymorphisms and type 1 diabetes. Direct-sequencing analysis of the CD30 and CD30L genes revealed four polymorphisms: one in the CD30 gene (-201G/A from the transcription start site), and three in the CD30L gene [CA repeat in the promoter, 276G/A in the exon 3, -73T/C in the intron 3 (IVS3 -73T/C)]. Association studies revealed no association between the CD30 and CD30L genes and type 1 diabetes in the whole population. In the female and male subpopulations, however, the frequency of (CA)(9) allele of the CD30L gene promoter or T allele of IVS3 -73T/C polymorphism in the CD30L gene was slightly higher in female patients with type 1 diabetes than that in control females. In conclusion, we could not find significant association between CD30 or CD30L genes and type 1 diabetes, but (CA)(9) allele in the promotor or T allele of -73T/C in intron 3 in CD30L gene might play a minor role in the pathogenesis of type 1 diabetes, only in the Japanese female population.

Adolescent↗
PubMed2001

Quick quantitative analysis of gene dosages associated with prognosis in neuroblastoma.

The amplification of the N-myc gene and a gain of the chromosome 17q arm correlate with an unfavorable outcome in patients with neuroblastoma. In this study, we determined the gene dosage of the N-myc gene (located at 2p24) and Survivin gene (located at 17q25) using the p53 gene (located at 17p13) as the internal control gene by the TaqMan polymerase chain reaction (PCR)-based gene dosage analysis in 25 neuroblastoma samples. Based on the assumption that the gene dosages of each gene of a normal individual lymphocytes are 1.0, 11 of the 25 cases with a corrected gene dosage of N-myc (N-myc/p53) of more than 2.0 had a more unfavorable prognosis than the 14 cases with a N-myc gene dosage of less than 2.0 (5-year survival rate: 18 vs. 71%, P<0.01). Ten of 25 cases with a corrected Survivin gene dosage (Survivin/p53) of more than 2.0 had a more unfavorable prognosis than the 15 cases with a Survivin gene dosage of less than 2.0 (5-year survival rate: 10 vs. 67%, P<0.01). This quantitative PCR system is considered to be useful for quickly and accurately evaluating the degree of malignancy of neuroblastoma in order to select the optimal treatment.

Child↗
PubMed2001

Human biotin-containing subunit of 3-methylcrotonyl-CoA carboxylase gene (MCCA): cDNA sequence, genomic organization, localization to chromosomal band 3q27, and expression.

3-Methylcrotonyl-CoA carboxylase (MCCase; EC 6.4.1.4) is a mitochondrial biotin enzyme and plays an essential role in the catabolism of leucine and isovalerate in animals, bacterial species, and plants. MCCase consists of two subunits, those that are biotin-containing and non-biotin-containing. The genes responsible for these subunits have been isolated in soybean, Arabidopsis thaliana, and tomatoes, but not in mammals. In humans, MCCase deficiency has been thought to be a rare metabolic disease, but the number of patients with MCCase deficiency appears to be increasing with a wide range of clinical presentations, some that result in a lethal condition and others that are asymptomatic. In this report, we have isolated and carried out chromosomal mapping of the gene for the biotin-containing subunit (A subunit) of the human MCCase gene, MCCA. The cDNA predicts an open reading frame coding for a 725-amino-acid protein with mitochondrial signal peptide, biotin carboxylase, and biotin-carrier domains. The gene is composed of at least 19 exons and covers more than 70 kb of sequence on band q27 of chromosome 3. MCCA was abundantly expressed in mitochondria-rich organs, such as the heart, skeletal muscles, kidney, and liver. In exon 13, we observed a His/Pro polymorphism at codon 464 (an A to C transition at nucleotide position 1391 in the cDNA sequence). Then, we determined the DNA sequences of the 5' untranslated region and entire coding regions in two patients with MCCase deficiency, but no sequence substitution was detected, suggesting that the gene mutations might be in the non-biotin-containing subunit (B subunit) gene, MCCB, in these patients.

Amino Acid Sequence↗