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Biomedical subjects

T Taguchi

Publications and source records attributed to T Taguchi.

At least 19 recordsLinked to original sources
PubMed2007

Use of the AO hook-plate for treatment of unstable fractures of the distal clavicle.

INTRODUCTION: We used a new internal fixative implant, the AO clavicle hook-plate, for treatment of unstable fractures of the distal clavicle. This study describes the operative procedure and the clinical results obtained, as well as discussion of the advantages and problems encountered. PATIENTS AND METHODS: Fifteen consecutive patients with unstable fractures of the distal clavicle (Neer type II) were treated using AO clavicle hook-plates. The average age of patients was 47 years and there were 13 males and 2 females. The mean follow-up period was 15.5 months. Plain radiographs of clavicles were used to assess bony union. Functional recovery of the shoulder joint was assessed using the Constant-Murley scoring system. RESULTS: All fractures eventually achieved solid bony union within 4 months after surgery. Thirteen patients (87%) showed hook migration into the acromion. Clinical results were excellent with a mean Constant-Murley score of 89 points at final follow-up. CONCLUSION: AO clavicle hook-plates are useful fixative implants for unstable fractures of the distal clavicle. Static fixation was achieved and physiotherapy can be started immediately after surgery. Early removal of the implant is recommended however because hooks inserted under the acromion migrated into the bone in most cases.

Adult↗
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 case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion.

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

Anaplastic Lymphoma Kinase↗
PubMed2006

Effect of pulse duration on resonant heating of laser-irradiated argon and deuterium clusters.

We study the effect of pulse duration on the heating of single van der Waals bound argon and deuterium clusters by a strong laser field using a two-dimensional (2D) electrostatic particle-in-cell (PIC) code in the range of laser-cluster parameters such that kinetic as well as hydrodynamic effects are active. Heating is dominated by a collisionless resonant absorption process that involves energetic electrons transiting through the cluster. A size-dependent intensity threshold defines the onset of this resonance [T. Taguchi, Physical Review Letters, 92, 20 (2004)]. It is seen that increasing the laser pulse duration lowers this intensity threshold and the energetic electrons take multiple laser periods to transit the cluster instead of one laser period. Our simulations also show that strong electron heating is accompanied by the generation of a high-energy peak in the ion energy distribution function. We also calculate the yield of thermonuclear fusion neutrons from exploding deuterium clusters using the PIC model with periodic boundary conditions that allows for the interaction of ions from neighboring clusters.

Journal Article↗
PubMed2006

HIV-1 Vpr induces ATM-dependent cellular signal with enhanced homologous recombination.

An ATM-dependent cellular signal, a DNA-damage response, has been shown to be involved during infection of human immunodeficiency virus type-1 (HIV-1), and a high incidence of malignant tumor development has been observed in HIV-1-positive patients. Vpr, an accessory gene product of HIV-1, delays the progression of the cell cycle at the G2/M phase, and ATR-Chk1-Wee-1, another DNA-damage signal, is a proposed cellular pathway responsible for the Vpr-induced cell cycle arrest. In this study, we present evidence that Vpr also activates ATM, and induces expression of gamma-H2AX and phosphorylation of Chk2. Strikingly, Vpr was found to stimulate the focus formation of Rad51 and BRCA1, which are involved in repair of DNA double-strand breaks (DSBs) by homologous recombination (HR), and biochemical analysis revealed that Vpr dissociates the interaction of p53 and Rad51 in the chromatin fraction, as observed under irradiation-induced DSBs. Vpr was consistently found to increase the rate of HR in the locus of I-SceI, a rare cutting-enzyme site that had been introduced into the genome. An increase of the HR rate enhanced by Vpr was attenuated by an ATM inhibitor, KU55933, suggesting that Vpr-induced DSBs activate ATM-dependent cellular signal that enhances the intracellular recombination potential. In context with a recent report that KU55933 attenuated the integration of HIV-1 into host genomes, we discuss the possible role of Vpr-induced DSBs in viral integration and also in HIV-1 associated malignancy.

Ataxia Telangiectasia Mutated Proteins↗
PubMed2006

Evaluation of a new caries detecting dye for primary and permanent carious dentin.

OBJECTIVE: This study evaluated the clinical efficacy of a new caries detecting dye using a laser fluorescence device (DIAGNOdent). METHOD: Primary and permanent teeth with dentin caries were stained with Caries Check (CC), containing 1% acid red in polypropylene glycol (MW=300) or Caries Detector (CD), containing 1% acid red in propylene glycol (MW=76). Primary-CC, primary-CD, permanent-CC and permanent-CD groups were prepared. In the CC groups, stained dentin was completely removed. In the CD groups, pink-stained dentin was retained according to the manufacturers' instructions. Cavities before and after caries removal were measured with the DIAGNOdent. Data were analyzed using ANOVA and Fisher's PLSD multiple comparison test at alpha=0.05. Regression analyses were performed between DIAGNOdent readings and scores obtained from the clinical parameters. RESULTS: For all groups, there were no significant differences in the DIAGNOdent readings before treatment. The DIAGNOdent readings after caries removal were: primary-CC (16.0+/-17.6), primary-CD (9.6+/-5.2), permanent-CC (11.0+/-7.0) and permanent-CD (7.1+/-3.8). Significant differences were identified between the permanent-CC and primary-CD, and permanent-CC and permanent-CD subgroups but not for the primary subgroups. Correlation coefficients between DIAGNOdent readings and clinical parameters were low. CONCLUSIONS: When dentin stained with Caries Check was completely removed, the DIAGNOdent readings were higher than those recorded when palely-stained pink dentin was retained with the Caries Detector, with significant difference observed for the permanent teeth. Caries Check may be used clinically to avoid excessive removal of caries-affected or sound dentin in permanent teeth but not in primary teeth.

Child↗
PubMed2006

Microkeratome assisted deep lamellar keratoprosthesis.

AIMS: To establish a keratoprosthesis (Kpro) surgical technique that maintains an intact superficial corneal layer. METHODS: A manual microkeratome (Moria LSK-1) was used to create a 130 mum flap of approximately 10 mm diameter in the right eye of Japanese white rabbits. The stoma beneath the flap area was dissected before the removal of a 5.0 mm stromal disc. A 5.0 mm collagen I immobilised poly(vinyl alcohol) (COL-PVA) disc was placed on the exposed posterior stroma close to Descemet's membrane. The flap was repositioned and fixed using 10-0 nylon sutures, which were removed 2 days following surgery. The corneas were followed clinically by slit lamp microscopy and photographs. Rabbits were sacrificed after 6 months, and the transplanted corneas were examined histologically by haematoxylin and eosin staining and immunohistochemistry against vimentin and alpha-smooth muscle actin (alpha-SMA). RESULTS: The transplanted COL-PVA discs remained transparent throughout the study, with no complications related to the flap or overlying epithelium. The interface between COL-PVA and Descemet's membrane remained clear without signs of opacification caused by scarring or cellular deposition. Pathology revealed the intact COL-PVA polymer in the posterior stroma, with minimal cellular infiltration along the anterior and posterior interfaces. Immunohistology shows vimentin and alpha-SMA staining at levels comparable to lamellar keratoplasty control. CONCLUSIONS: Microkeratome assisted deep lamellar keratoprosthesis may be a safe technique for the transplantation of artificial hydrogels for therapeutic purposes.

Animals↗
PubMed2006

Concurrent chemoradiotherapy with carboplatin and uracil-ftegafur in patients with stage two (T2 N0 M0) squamous cell carcinoma of the glottic larynx.

This study aimed to evaluate the efficacy and toxicity of concurrent chemoradiotherapy as a primary treatment modality for larynx preservation in patients with stage two squamous cell carcinoma (SCC) of the glottic larynx. Between February 2000 and August 2003, a total of 20 patients received concurrent chemoradiotherapy. Carboplatin was given intravenously once a week during the period of radiotherapy. The weekly carboplatin dose was based on the area under the curve 1 to 1.25. Uracil-ftegafur (UFT) was given in a daily oral dose of 300 mg as tegafur. Radiotherapy was delivered five days a week using a once-daily fractionation of 2.0 Gray (Gy), to a total dose of 66-72 Gy. The three-year overall survival rate with larynx preservation was 100 per cent. Concurrent chemoradiotherapy with carboplatin and UFT for stage two SCC of the glottic larynx was safe and effective in improving local control with larynx preservation.

Adult↗
PubMed2006

Spontaneous rupture of sacrococcygeal teratoma associated with acute fetal anemia.

Sacrococcygeal teratoma (SCT) is the most common congenital tumor, with affected fetuses having a high risk of perinatal complications and death. We report a case of a fetus with an SCT that developed acute anemia due to spontaneous rupture of the tumor in utero. The fetus was referred at 25 weeks' gestation for evaluation of a large solid and cystic mass in the sacral region. There were no signs of hydrops or placentomegaly. At 33 weeks' gestation, loss of variability in the fetal heart rate pattern was recorded. Doppler ultrasonography showed increased middle cerebral artery peak systolic velocity, suggesting fetal anemia. Markedly bloody amniotic fluid, with 82% hemoglobin F, was observed on amniocentesis, suggesting rupture of the SCT with active fetal bleeding. An emergency Cesarean section was performed. At delivery, the tumor was bleeding actively and the neonatal hemoglobin concentration was 3.1 g/dL. There were no findings of hemorrhage or necrosis within the tumor. The neonate received a blood transfusion, and surgical resection of the tumor was carried out on the first day after delivery. Postoperatively, the baby did well. We suggest that fetal SCTs run the risk of inducing acute fetal anemia due to intrauterine hemorrhage of the tumor, a finding which could lead to an earlier and more appropriate management of this condition.

Acute Disease↗
PubMed2006

Association between the HER2 expression and histological differentiation in Wilms tumor.

Human epidermal growth factor receptors (HER) play a critical role in the branching morphogenesis of renal tubules. In the current study, we analyzed the expression of HER2 in Wilms tumor and assessed the role of this gene in the tumorgenesis of Wilms tumor. During the period from 1960 to 2005, 40 patients with Wilms tumor were treated in our department. Twenty-four of those patients (except those with clear cell sarcoma of the kidney and malignant rhabdoid tumor of the kidney) were collected and assessed. The histological component of each Wilms tumor was divided into three categories (epithelial, blastemal, and mesenchymal) and the extent of HER2 protein expression was analyzed immunohistochemically. The normal kidney tissue accompanied with 12 cases of Wilms tumor was also examined. In the normal kidney, HER2 showed a strong immunoreactivity in the cell membranes of the collecting tubules and in the endothelial cells. Of 24 cases, 15 cases showed an epithelial component, while 24 cases had a blastemal component and 21 cases had a mesenchymal component, respectively. Among the 15 specimens with epithelial cell differentiation, eight (53.3%) showed HER2 immunoreactive epithelial cells. HER2 immunoreactive blastemal cells were present in 11 (45.8%) of 24 specimens with blastemal cells. On the other hand, only 3 (14.3%) of 21 specimens containing mesenchymal cells showed HER2 immunoreactivity. These results suggest that the extent of HER2 expression is associated with epithelial differentiation in Wilms tumor. These histological findings may therefore help to explain the development of Wilms tumor from the standpoint of histological differentiation.

Child↗
PubMed2006

Purinergic receptor ligands stimulate pro-opiomelanocortin gene expression in AtT-20 pituitary corticotroph cells.

Although recent studies have suggested that purinergic receptors are expressed in the anterior pituitary gland, their involvement in the regulation of pituitary hormone gene expression is not completely understood. In the present study, we examined the expression of purinergic receptors and the effects of purinergic receptor ligands on pro-opiomelanocortin (POMC) gene expression, in AtT20 mouse corticotroph cells. We identified the expression of most of the purinergic receptor subtypes (A1, A2, P2X1, 3-7, P2Y1, 2, 4) mRNAs, analysed by the reverse transcriptase-polymerase chain reaction. We also found that adenosine and ATP, two representative and endogenous agonists of A1-3 and P2X/P2Y receptors, respectively, stimulated the 5'-promoter activity of the POMC gene in a dose- and time-related manner. When these ligands were simultaneously used with corticotrophin-releasing hormone (CRH), effects that were more than additive were observed, suggesting an enhancing role of these compounds in CRH-mediated adrenocorticotrophic hormone (ACTH) synthesis. These ligands also stimulated the expression of transcription factors involved in the regulation of the POMC gene, but did not enhance ACTH secretion. Finally, the positive effect of adenosine as well as CRH was completely inhibited by the protein kinase A inhibitor H89, whereas that of ATP was not influenced, indicating that different intracellular signalling pathways mediate these effects. Altogether, our results suggest a stimulatory role for these purinergic receptor ligands in the regulation of POMC gene expression in corticotroph cells. Because adenosine and ATP are known to be produced within the pituitary gland, it is possible they may be acting in an autocrine/paracrine fashion.

Adenosine↗
PubMed2006

Suppressive effects of dehydroepiandrosterone and the nuclear factor-kappaB inhibitor parthenolide on corticotroph tumor cell growth and function in vitro and in vivo.

Dehydroepiandrosterone (DHEA) is believed to have an anti-tumor effect, as well as anti-inflammatory, antioxidant, and anti-aging effects. To clarify the possible inhibitory action of DHEA on pituitary tumor cells, we tested the effects of DHEA, alone or in combination with the nuclear factor-kappaB (NF-kappaB) inhibitor parthenolide (PRT), on AtT20 corticotroph cell growth and function both in vitro and in vivo. We found that, in vitro, DHEA and PRT had potent inhibitory effects on pro-opiomelanocortin and NF-kappaB-dependent gene expression. They also suppressed the transcription activity of survivin, a representative anti-apoptotic factor, and induced apoptosis in this cell line. Furthermore, using BALB/C nude mice with xenografts of AtT20 cells in vivo, we found that the combined administration of DHEA and PRT significantly attenuated tumor growth and survivin expression. The treatment also decreased the elevated plasma corticosterone levels and ameliorated the malnutrition induced by tumor growth. Altogether, these results suggested that combined treatments of DHEA and PRT potently inhibit the growth and function of corticotroph tumor cells both in vitro and in vivo. This effect may, at least partly, be caused by the suppressive effects of these compounds, such as survivin and other inhibitor of apoptosis proteins, on NF-kappaB-mediated gene transcription.

Adjuvants, Immunologic↗
PubMed2006

[Surgical treatment for stage IV lung cancer].

OBJECTIVE: To find out the optimal surgical indication in stage IV lung cancer patients, we evaluated them retrospectively. METHODS & RESULTS: From 1975 to 2005, 62 patients without multiple metastases were operated at our hospital. The most common histological type was adenocarcinoma (67.7%). The metastatic lesions were lung (33.9%), brain (24.2%), liver, bone, adrenal gland and so on. The overall survival rate of stage IV lung cancer was 10.4% at 5-year. Five-year survival for patients with lung or brain metastasis who had no lymph node metastasis were significantly more superior than those with lymph node metastasis (p=0.0389, 0.0021). Four of 62 patients had 5-year survival. Two were lung and the others were brain and adrenal gland metastasis without lymph node metastasis. CONCLUSION: Stage IV lung cancer with lung or brain or adrenal gland metastasis without lymph node metastasis should be resected.

Adenocarcinoma↗
PubMed2005

Effects of lithium on endolymph homeostasis and experimentally induced endolymphatic hydrops.

There is evidence to suggest that water homeostasis in the inner ear is regulated via the vasopressin (VP)-aquaporin 2 (AQP2) system in the same fashion as in the kidney. The VP-AQP2 system in the kidney is well known to be inhibited by lithium, resulting in polyuria due to a decrease in reabsorption of water in the collecting duct of the kidney. Therefore, lithium is also likely to inhibit the VP-AQP2 system in the inner ear, and consequently exert some influence on inner ear fluid homeostasis. In this study, we investigated the effects of lithium on AQP2 expression in the rat inner ear, and on the cochlear fluid volume in hydropic ears of guinea pigs. A quantitative PCR study revealed that lithium reduced AQP2 mRNA expression in the cochlea and endolymphatic sac. Lithium application also decreased the immunoreactivity of AQP2 in the cochlea and endolymphatic sac. In a morphological study, lithium intake significantly reduced endolymphatic hydrops dose-dependently. These results indicate that lithium acts on the VP-AQP2 system in the inner ear, consequently producing a dehydratic effect on the endolymphatic compartment.

Animals↗
PubMed2005

Characterization of new monoclonal antibodies against porcine lymphocytes: molecular characterization of clone 7G3, an antibody reactive with the constant region of the T-cell receptor delta-chains.

A battery of mouse monoclonal antibodies (mAbs) reactive with porcine peripheral blood (PB) leukocytes was generated. Among the mAbs, 6F10 was found to react probably with cluster of differentiation (CD)8 alpha-chain, while 7G3 and 3E12 were found to recognize gammadelta T-cells, as revealed by two-color flow cytometric and immunoprecipitation studies. 7G3 was shown to react with the constant (C) region of the T-cell receptor (TCR) delta-chain by the following facts: (1) 7G3 immunoprecipitated full-length TCR delta-chain protein fused with glutathione S-transferase (GST) produced by Esherichia coli and (2) 7G3 reacted with TCR delta-chain expressing Cos-7 cells transfected with either full-length or N-terminal deleted mutant cDNA, but did not react with Cos-7 cells transfected with C-terminal deleted mutant TCR delta-chain cDNA. All three mAbs produced high-quality immunostaining results on frozen sections, revealing a distinct distribution of gammadelta T-cells and CD8(+) cells. This report precisely characterizes mAbs against porcine TCR for the first time, facilitating molecular biological investigations of the porcine immune system.

Amino Acid Sequence↗