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Biomedical subjects

K Miwa

Publications and source records attributed to K Miwa.

At least 19 recordsLinked to original sources
PubMed2006

Evidence for white matter disruption in traumatic brain injury without macroscopic lesions.

BACKGROUND: Non-missile traumatic brain injury (nmTBI) without macroscopically detectable lesions often results in cognitive impairments that negatively affect daily life. AIM: To identify abnormal white matter projections in patients with nmTBI with cognitive impairments using diffusion tensor magnetic resonance imaging (DTI). METHODS: DTI scans of healthy controls were compared with those of 23 patients with nmTBI who manifested cognitive impairments but no obvious neuroradiological lesions. DTI was comprised of fractional anisotropy analysis, which included voxel-based analysis and confirmatory study using regions of interest (ROI) techniques, and magnetic resonance tractography of the corpus callosum and fornix. RESULTS: A decline in fractional anisotropy around the genu, stem and splenium of the corpus callosum was shown by voxel-based analysis. Fractional anisotropy values of the genu (0.47), stem (0.48), and splenium of the corpus callosum (0.52), and the column of the fornix (0.51) were lower in patients with nmTBI than in healthy controls (0.58, 0.61, 0.62 and 0.61, respectively) according to the confirmatory study of ROIs. The white matter architecture in the corpus callosum and fornix of patients with nmTBI were seen to be coarser than in the controls in the individual magnetic resonance tractography. CONCLUSIONS: Disruption of the corpus callosum and fornix in patients with nmTBI without macroscopically detectable lesions is shown. DTI is sensitive enough to detect abnormal neural fibres related to cognitive dysfunction after nmTBI.

Adolescent↗
PubMed2006

Experimental signature of medium modifications for rho and omega mesons in the 12 GeV p+A reactions.

The invariant mass spectra of e+e- pairs produced in 12 GeV proton-induced nuclear reactions are measured at the KEK Proton Synchrotron. On the low-mass side of the meson peak, a significant enhancement over the known hadronic sources has been observed. The mass spectra, including the excess, are well reproduced by a model that takes into account the density dependence of the vector meson mass modification, as theoretically predicted.

Journal Article↗
PubMed2006

Conversion of elective laparoscopic to open cholecystectomy between 1993 and 2004.

BACKGROUND: Laparoscopic cholecystectomy (LC) is the standard treatment for symptomatic gallbladder disease. The identification of factors that reliably predict the likely need to convert LC to an open procedure would provide short-term benefits in terms of patient education and postoperative expectations. METHODS: Between 1993 and 2004, 1179 elective LCs were attempted from a total of 1339 elective cholecystectomies. The change in conversion rate between 1993-1999 and 2000-2004 was analysed. Factors predictive of higher risk for conversion were also identified. RESULTS: Eighty-nine LCs (7.5 per cent) required conversion. Gallbladder wall thickness and a history of common bile duct (CBD) stones, treated by preoperative endoscopic sphincterotomy, were predictors of conversion. The proportion of patients who underwent LC was the same in 1993-1999 (87.5 per cent) and 2000-2004 (88.8 per cent), but the conversion rate increased significantly from 5.3 to 10.6 per cent in these two time intervals. In addition, the proportion of patients with a history of CBD stones rose significantly, from 6.4 per cent in 1993-1999 to 11.0 per cent in 2000-2004. CONCLUSION: The conversion rate increased over the 12-year interval of the study. A history of preoperative endoscopic sphincterotomy and a thickened gallbladder wall contributed to the likelihood of conversion.

Adolescent↗
PubMed2006

Development of serum IgM antibodies against superantigens of Staphylococcus aureus and Streptococcus pyogenes in Kawasaki disease.

To serologically determine the association of microbial superantigens and the pathogenesis of Kawasaki disease (KD), we conducted a case-control study. Serum IgG and IgM antibodies against staphylococcal enterotoxin A (SEA), SEB, SEC, toxic shock syndrome toxin-1 (TSST-1), and streptococcal pyrogenic exotoxin A (SPEA) were measured by an enzyme-linked immunosorbent assay in 293 serum samples from 65 KD patients on clinical days 1-28 and 120 control samples. The administration of immunoglobulin products, which contain high concentrations of IgG antibodies against all the superantigens, directly elevated antitoxin IgG antibodies in KD patients. In contrast, antitoxin IgM antibodies were not detected in immunoglobulin products. Actually, we found a significant elevation of IgM antibodies against SEA in KD patients in the first (median titre: 0.020, P < 0.01 versus control), second (0.024, P < 0.001), third (0.030, P < 0.001) and fourth (0.038, P < 0.001) weeks, compared to the controls (0.015). Significant differences of IgM antibodies were also true for SEB, TSST-1, and SPEA throughout the first to fourth weeks, and for SEC throughout the second to fourth weeks. The prevalence of KD patients having high IgM titres (> mean + 2SD of control values) to the 5 superantigens was increased with the clinical weeks, and reached 29-43% of KD subjects at the fourth week. This is the first study that describes kinetics of IgM antibodies against superantigens and clarifies the serological significance throughout the clinical course of KD. Our results suggest that multiple superantigens involve in the pathogenesis of KD.

Antibodies, Bacterial↗
PubMed2006

Aldose reductase gene is associated with diabetic macroangiopathy in Japanese Type 2 diabetic patients.

AIMS: The aldose reductase (AR) gene, a rate-limiting enzyme of the polyol pathway, has been investigated as a candidate gene in determining susceptibility to diabetic microangiopathy. However, the association of the AR gene with diabetic macroangiopathy has not been investigated. Therefore, the present study was conducted to determine whether genetic variations of AR may determine susceptibility to diabetic macroangiopathy. METHODS: There were 378 Type 2 diabetic patients enrolled in this study. A single nucleotide polymorphism in the promoter region (C-106T) was genotyped and the AR protein content of erythrocytes measured by ELISA. RESULTS: There were no significant differences in genotypic or allelic distribution in patients with or without ischaemic heart diseases, but there was a significant increase in the frequency of the CT + TT genotype and T allele in patients with stroke (P = 0.019 and P = 0.012). The erythrocyte AR protein content was increased in patients with the CT and TT genotype compared with those with the CC genotype. After adjustment for age, duration of diabetes, body mass index, systolic blood pressure, HbA1c, and serum creatinine, triglycerides, and total cholesterol in multivariate logistic-regression models, the association between this AR genotype and stroke remained significant. CONCLUSIONS: Our results suggest that the CT or TT genotype of the AR gene might be a genetic marker of susceptibility to stroke in Type 2 diabetic patients. This observation might contribute to the development of strategies for the prevention of stroke in Type 2 diabetic patients.

Adult↗
PubMed2006

[Huge mediastinal mature teratoma with combined resection of adjacent structures; report of a case].

We report a case of a 64-year-old woman with an anterior mediastinal tumor on a chest computed tomography (CT) before operation of uterine cancer. After the radical surgery and a chemotherapy for uterine cancer, surgical resection of mediastinal tumor was performed in July 2005 because of gradually progression in tumor size. Under the median sternotomy, the tumor revealed intensive adhesion to the right lung and the left brachiocephalic vein. We performed a complete resection of the tumor with combined resection of adherent parts of them. The tumor was 9 x 8 cm in size, containing with yellow cream-like fluid and hair. Histologically, the tumor was diagnosed as a mature teratoma with the tissue of bone, digestive tract epithelium, bronchial epithelium and so on. In benign teratoma, it is not rare to perforate to the adjacent structures. So, we concluded if the mediastinal teratoma was suspected, long-term observation had the risk for adhesion and perforation to adjacent tissue, and in case of operation, we should keep in mind the possibility of combined resection of involved organs.

Brachiocephalic Veins↗
PubMed2005

Near-threshold diffractive psi-meson photoproduction from the proton.

Photoproduction of a phi meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections at t = -|t|min do not increase smoothly as Egamma increases but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that phi mesons are photoproduced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.

Journal Article↗
PubMed2005

Production of the neutron-rich hypernucleus 10LambdaLi in the (pi-,K+) double charge-exchange reaction.

In order to produce a neutron-rich Lambda hypernucleus for the first time, we carried out an experiment by utilizing the (pi-,K+) double charge-exchange reaction on a 10B target. We observed the production of a 10LambdaLi hypernucleus. The cross section for the Lambda bound region was found to be 11.3+/-1.9 nb/sr with the 1.2 GeV/c incident momentum, which is compared with the 10LambdaB hypernucleus production cross section, 7.8+/-0.3 microb/sr, in the (pi+,K+) reaction with a 1.05 GeV/c incident momentum beam.

Journal Article↗
PubMed2005

Multiple organ failure caused by end-stage liver disease successfully treated with living donor liver transplantation using perioperative percutaneous cardiopulmonary support: a case report.

A 54-year-old female diagnosed with primary biliary cirrhosis (PBC) 10 years earlier was referred for a living donor liver transplant (LDLT). During her workup, she developed pulmonary edema and respiratory failure due to aspiration pneumonia, which required artificial ventilation. The PaO2/FiO2 (P/F) ratio at that time was 60. Although continuous hemodiafiltration (CHDF) and plasma exchange (PE) were initiated, improvement in the P/F ratio was limited to 133. As transplantation was the only approach to save this patient, we performed LDLT using a right lobe graft aided by percutaneous cardiopulmonary support (PCPS). The graft weight was 650 g and the graft weight/recipient weight ratio was 1.6%. During LDLT, the patient's cardiopulmonary function was stable with PCPS, and the surgical procedure was completed without complications. Following the surgery, she continued to have high-end inspiratory pressure and progressed to the chronic phase of adult respiratory distress syndrome (ARDS). We treated her with low-dose steroid therapy and she improved gradually. The patient was weaned off mechanical ventilation and was discharged approximately 25 weeks after LDLT. In the condition of cardiac or respiratory failure, cadaveric liver transplantation using plasmapheresis is contraindicated because of the associated high mortality rate. Our case suggests that if infections are controlled, a patient with multiple organ failure (MOF) due to end-stage liver disease might be successfully treated with LDLT aided by plasmapheresis and PCPS.

Cardiopulmonary Resuscitation↗
PubMed2005

Inhibition of ets, an essential transcription factor for angiogenesis, to prevent the development of abdominal aortic aneurysm in a rat model.

The pathophysiology of abdominal aortic aneurysms (AAA) is considered to be complicated. As matrix degradation contributes to the progression of AAA, the destruction and degradation of elastin fibers caused by an increase in matrix metalloproteinases (MMPs) plays a pivotal role in the development of AAA. Although ets, an essential transcription factor for angiogenesis, regulates MMPs, the role of ets in the development of AAA has not yet been clarified. Thus, we evaluated the role of ets in a rat AAA model using a decoy strategy. Transfection of ODN into AAA was performed by transient aortic perfusion of elastase and by wrapping the AAA in a delivery sheet containing decoy ODN. The inhibitory effect of ets decoy ODN on ets binding activity was confirmed by gel mobility shift assay. MMPs expression was decreased in the aorta transfected with ets decoy ODN as compared to scrambled decoy ODN. Also, ultrasound study demonstrated that elastase-induced aneurismal dilation was significantly suppressed by transfection of ets decoy ODN at 4 weeks after treatment as compared to scrambled decoy ODN. Moreover, the destruction of elastin fibers was inhibited in the aorta transfected with ets decoy ODN, accompanied by a reduction of MMPs expression. An inhibitory effect of decoy ODN on MMP expression was confirmed by ex vivo experiments showing that transfection of decoy ODN into an organ culture of human aorta resulted in significant inhibition of the secretion of both MMP-1 and MMP-9. Here, we demonstrated that ets may play a pivotal role in the progression of AAA through the activation of MMPs in a rat model. Ets might be a potential target to develop pharmacotherapy/gene therapy to treat AAA through the inhibition of MMPs.

Animals↗
PubMed2005

Relationship of lipoprotein lipase and hepatic triacylglycerol lipase activity to serum adiponectin levels in Japanese hyperlipidemic men.

OBJECTIVE: The aim of this study was to determine how lipoprotein lipase (LPL) and hepatic triacylglycerol lipase (HTGL) activity relate to serum adiponectin levels. RESEARCH DESIGN AND METHODS: Fifty-five hyperlipidemic Japanese men were recruited for this study. LPL and HTGL activity in post-heparin plasma (PHP) was measured using Triton X-100 emulsified-[14C] triolein. The remaining activity in the presence of 1M NaCl was defined as HTGL activity. Serum adiponectin levels were determined by an enzyme-linked immunosorbent assay system. RESULT: LPL activity had a positive relationship with HDL2, but had no relation with HDL3, while HTGL had positive relationship with HDL3, but had no relationship with HDL2. LPL activity showed a positive relationship [r = 0.345, p = 0.010] to serum adiponectin levels, while and HTGL activity showed an inverse relationship [r = - 0.365 p = 0.006]. Multiple regression analysis with LPL and HTGL as dependent variables and age, BMI, serum adiponectin and the homeostasis model assessment of insulin resistance (HOMA-IR) as independent variables showed LPL and HTGL's association to adiponectin did not persist after adjustments for these covariants. However, the association of LPL activity to HOMA-IR was found to persist after adjustments of age, BMI, and serum adiponectin. CONCLUSIONS: There was a co-linearity between insulin sensitivity and adiponectin as well as insulin sensitivity and LPL/HTGL activity.

Aged↗
PubMed2004

Intravascular ultrasound findings of coronary wall morphology in a patient with pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is an inherited disorder characterised by progressive calcification of the elastic fibres in the skin, eye, and cardiovascular system. Recently, mutations in the ATP binding cassette transporter gene (ABCC6) were identified as cause of this disease. Although patients with PXE often have coronary artery disease, little is known about the process and the mechanism of coronary artery disease in PXE. In this report, intravascular ultrasound (IVUS) imaging was performed in a female patient with PXE seven years after the onset of skin lesion to assess the coronary wall morphology in detail. IVUS showed a unique five layer appearance without acoustic shadowing along the vessel wall observed in the angiographically normal portion. These findings may reflect the earlier stage of coronary artery disease caused by PXE before calcification of the internal elastic laminae.

Angioid Streaks↗
PubMed2004

Discrepancy between lesion distributions on methionine PET and MR images in patients with glioblastoma multiforme: insight from a PET and MR fusion image study.

OBJECTIVE: To examine (11)C-methyl methionine (MET) accumulation on positron emission tomographic (PET) imaging of glioblastoma multiforme to determine the distribution of metabolic abnormality compared with magnetic resonance imaging (MRI). METHODS: Contemporaneous MRI was superimposed on corresponding MET-PET images in 10 patients with newly diagnosed glioblastoma multiforme before treatment. Differences between the extended area of MET accumulation on PET imaging (MET area), the gadolinium (Gd) enhanced area on T1 weighted images (Gd area), and the abnormal high signal intensity area on T2 weighted images (T2-high area) were assessed. RESULTS: The MET area was larger than the Gd area and included the entire Gd area. The discrepancy in volume between the MET and Gd areas became greater with increasing tumour diameter. On average, 58.6% of the MET area was located within the Gd area, 90.1% within 10 mm outside the Gd area, 98.1% within 20 mm, and 99.8% within 30 mm. A newly developed Gd area had emerged in five of the 10 cases up to the time of study. In three of the five cases this was in the MET area even after complete surgical resection of the Gd area on the initial MRI; in the remaining two it originated in the residual Gd area after surgery. In all cases, the T2-high area was larger than the MET area. The MET area extended partly beyond the T2-high area in nine cases, and was completely within it in one. CONCLUSIONS: Glioblastoma multiforme cells may extend over the Gd area and more widely with increasing tumour size on Gd-MRI. The T2-high area includes the greater part of the tumour but not its entire area. The methods reported may be useful in planning surgical resection, biopsy, or radiosurgery.

Adult↗
PubMed2003

Quantitative evaluation of metastases in axillary lymph nodes of breast cancer.

We have established a highly sensitive and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method to detect axillary lymph node metastases of breast cancer. Amplifying cytokeratin 19 (CK19) mRNA transcripts using real-time TaqMan PCR made it possible to quantify axillary metastatic burden. Metastases in 358 axillary lymph nodes obtained from 23 breast cancers of 22 patients were investigated by conventional haematoxylin and eosin (H&E) staining, immunohistochemical staining and quantitative RT-PCR assay. The detection rates of axillary lymph node metastasis using H&E staining, immunohistochemistry and RT-PCR assay were 4.5, 5.9 and 13.1%, respectively. RT-PCR assay was the most sensitive of these three methods for detecting lymph node metastases. Cytokeratin 19 mRNA expression values of both histologically and immunohistochemically positive lymph nodes were significantly higher than the values for lymph nodes judged to be negative by both histological and immunohistochemical methods (P<0.0001), and those of histologically negative, but immunohistochemically positive lymph nodes were significantly higher than the values for lymph nodes judged to be negative by both histological and immunohistochemical methods (P<0.0001). Furthermore, metastatic rates of sentinel nodes were higher than the rates of nonsentinel lymph nodes as measured by all three methods. These results indicate that quantitative RT-PCR assay is a sensitive and reliable method for detecting lymph node metastasis. Furthermore, quantification of metastases in sentinel lymph nodes by quantitative RT-PCR assay may be useful to assess the entire axillary burden of breast cancer patients.

Adult↗
PubMed2003

Beam-polarization asymmetries for the p(gamma-->, K+)Lambda and p(gamma-->, K+)Sigma(0) reactions for E(gamma)=1.5-2.4 GeV.

Beam polarization asymmetries for the p(gamma-->,K+)Lambda and p(gamma-->,K+)Sigma(0) reactions are measured for the first time for E(gamma)=1.5-2.4 GeV and 0.6<cos((theta(c.m.)(K+))<1.0 by using linearly polarized photons at the Laser-Electron-Photon facility at SPring-8 (LEPS). The observed asymmetries are positive and gradually increase with rising photon energy. The data are not consistent with theoretical predictions based on tree-level effective-Lagrangian approaches. Including the new results in the development of the models is, therefore, crucial for understanding the reaction mechanism and to test the presence of baryon resonances which are predicted in quark models but are thus far undiscovered.

Journal Article↗
PubMed2003

Micrometastases in sentinel nodes of gastric cancer.

The sentinel node (SN) is the first lymph node in the lymphatic basin to be affected by metastasis from the primary tumour and is used to predict the status of the remaining nodes in the basin. We succeeded in detecting SNs of clinically early gastric cancers by intraoperative injection of a blue dye around the tumour. In the study presented here, multiple-marker reverse transcription-polymerase chain reaction (RT-PCR) was used to detect micrometastases in SNs and results were compared with those obtained with conventional histology. Expressions of cytokeratin-18 (CK-18), carcinoembryonic antigen (CEA), human telomerase reverse transcriptase (hTRT) and MUC-1 in SNs were determined by RT-PCR and Southern blot assay. Of the 213 SNs obtained from 35 cases of gastric cancer, eight nodes (3.8%) from five patients contained metastases that could be identified by conventional histology. However, CK-18 mRNA was expressed in 15 (7.0%), CEA in 12 (5.6%), hTRT in 10 (4.7%), and MUC-1 in 12 (5.6%) nodes, with at least one mRNA marker expressed in 25 nodes (11.7%) obtained from six patients. In the five patients with nodal metastases identified by conventional histology, two had metastases in both SNs and non-SNs. And, in the 30 patients without nodal metastases identified by conventional histology, one patient with micrometastases in the SNs identified by RT - PCR and Southern blot assay also had metastases in non-SNs as identified by serial sectioning and immunostaining of CK-18. All additional metastases were detected in non-SNs located in the same lymphatic basin as the previously detected SNs. This suggests that lymph node dissection of early-stage gastric cancer in the lymphatic basin may be mandatory even for patients without histologically detectable metastases in SNs.

Adenocarcinoma↗
PubMed2003

Evidence for a narrow S = +1 baryon resonance in photoproduction from the neutron.

The gamman-->K(+)K(-)n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed at 1.54+/-0.01 GeV/c(2) with a width smaller than 25 MeV/c(2) and a Gaussian significance of 4.6sigma. The strangeness quantum number (S) of the baryon resonance is +1. It can be interpreted as a molecular meson-baryon resonance or alternatively as an exotic five-quark state (uuddsmacr;) that decays into a K+ and a neutron. The resonance is consistent with the lowest member of an antidecuplet of baryons predicted by the chiral soliton model.

Journal Article↗