Biomedical subjects

K Shimizu

Publications and source records attributed to K Shimizu.

At least 19 recordsLinked to original sources

PubMed2007

Germ line transformation of the silkworm, Bombyx mori, using the transposable element Minos.

We investigated the use of Minos as a vector for transgenesis in the silkworm, Bombyx mori. We first constructed a vector plasmid with the green fluorescent protein (GFP) gene fused with the silkworm cytoplasmic actin gene (A3) promoter, and a helper plasmid with the Minos transposase gene controlled by the same A3 promoter. Injection of the vector and helper plasmid DNA into silkworm eggs produced transgenic animals in the following generation. The efficiency of transgenic silkworm production using this method was much lower than that obtained using piggyBac-mediated germ line transformation. However, >40-fold increase in the efficiency of producing transgenic silkworms was obtained using an in vitro synthesized source of Minos transposase mRNA. We conclude that the Minos transposon is a useful vector for construction of transgenic silkworms, particularly when in vitro synthesized mRNA is used. This is the first report showing that Minos can be used as a vector for germ-line transformation in lepidopteran insects.

Actins↗

PubMed2006

Down-regulation of an inhibitor of cell growth, transmembrane protein 34 (TMEM34), in anaplastic thyroid cancer.

PURPOSE: Ansaplastic thyroid cancer (ATC) is one of the most lethal malignancies, but the carcinogenic mechanism of ATC has not been clarified. Recently, we performed a cDNA microarray analysis and identified transmembrane protein 34 (TMEM34) that down-regulated in anaplastic thyroid cancer cell lines (ACL)s as compared to normal thyroid tissues. METHODS: To investigate the role of TMEM34 in ATC carcinogenesis, we examined expression levels of TMEM34 in ACLs as well as differentiated thyroid cancers (DTC)s and normal human tissues. To explore the effect of TMEM34 in ATC development, cell-growth assays with KTA2 cells were performed. RESULTS: Expression of TMEM34 was down-regulated in all 11 ACLs, as compared to either normal thyroid tissues or cell lines derived from papillary or follicular thyroid cancers. TMEM34 was expressed ubiquitously in normal human tissues tested. Transfection of TMEM34 into KTA2 cells led to inhibition of cell growth. CONCLUSIONS: Our findings suggest that TMEM34 might be a tumor suppressor gene, associated with the development of ATC from DTC.

Carcinoma↗

PubMed2006

Change in the cross-sectional area of a patellar tendon graft after anterior cruciate ligament reconstruction.

The purpose of this study was to clarify the change in the cross-sectional area (CSA) of a patellar tendon graft after anterior cruciate ligament (ACL) reconstruction, and its relationship with postoperative knee laxity. Forty patients (25 men and 15 women) were included in this study. Intraoperative CSA measurements were performed with an instrumented areamicrometer, while a magnetic resonance imaging (MRI) evaluation was utilized for the assessment postoperatively. For intraoperative measurement, the average CSA of a 10-mm wide patellar tendon graft was 32.3 +/- 7.0 mm2, while the average CSA measured at follow-up (mean: 14.8 months) was 48.8 mm2, showing a significant mean increase ratio of 49.4%. This value corresponded to 115% of the native ACL. The average CSA measured in 30 patients at 6 months was 49.7 mm2, almost equal to the value at the final follow-up (49.8 mm2) in the same patient group. Among potentially influential factors, postoperative notch width (available space for the ACL graft) had significant correlation with the CSA of the graft at follow-up. Finally, both intra- and postoperative CSA values did not correlate with postoperative knee laxity, indicating that a bigger graft does not guarantee a better laxity.

Adolescent↗

PubMed2006

Actions anchored by concepts: defective action comprehension in semantic dementia.

OBJECTIVE: To study the ability of patients with semantic dementia to understand actions, in order to examine the contribution of semantic memory to action comprehension. METHODS: The ability to comprehend symbolic and instrumental actions was assessed in 6 patients with semantic dementia and 10 healthy controls. The patients were also given the imitation test of meaningful and meaningless actions. RESULTS: In all patients with semantic dementia, comprehension of both symbolic and instrumental actions was defective. The comprehension of symbolic actions was more impaired than that of instrumental actions. Their ability to imitate other's actions was well preserved. CONCLUSION: This study showed that comprehension of action was impaired in semantic dementia, suggesting that semantic memory has an important role in comprehension of human action.

Aged↗

PubMed2006

Observation and control of transverse energy-transport barrier due to the formation of an energetic-electron layer with sheared ExB flow.

Off-axis electron-cyclotron heating in an axisymmetric barrier mirror produces a cylindrical layer with energetic electrons, which flow through the central cell and into the end region. The layer, producing a localized bumped ambipolar potential Phi(C), forms a strong shear of radial electric fields E(r) and peaked vorticity with the direction reversal of E(r)xB sheared flow near the Phi(C) peak. Intermittent vortexlike turbulent structures near the layer are suppressed in the central cell by this actively produced transverse energy-transport barrier; this results in T(e) and T(i) rises surrounded by the layer.

Journal Article↗

PubMed2006

International uniform response criteria for multiple myeloma.

New uniform response criteria are required to adequately assess clinical outcomes in myeloma. The European Group for Blood and Bone Marrow Transplant/International Bone Marrow Transplant Registry criteria have been expanded, clarified and updated to provide a new comprehensive evaluation system. Categories for stringent complete response and very good partial response are added. The serum free light-chain assay is included to allow evaluation of patients with oligo-secretory disease. Inconsistencies in prior criteria are clarified making confirmation of response and disease progression easier to perform. Emphasis is placed upon time to event and duration of response as critical end points. The requirements necessary to use overall survival duration as the ultimate end point are discussed. It is anticipated that the International Response Criteria for multiple myeloma will be widely used in future clinical trials of myeloma.

Humans↗

PubMed2006

Oesophageal squamous cell carcinoma may develop within a background of accumulating DNA methylation in normal and dysplastic mucosa.

BACKGROUND: Oesophageal squamous cell carcinoma (OSCC) often arises from preceding dysplastic lesions in the oesophageal epithelium. However, the molecular changes occurring in premalignant lesions are not well understood. An epigenetic change is an example of OSCC that may occur within the epithelium. AIM: To investigate the methylation status of multiple promoters in cancer-derived DNA, as well as in the background epithelium of OSCC, including dysplastic lesions and non-neoplastic mucosa. The normal epithelium from patients without cancer was also examined. The findings were correlated with the mutational status of p53. PATIENTS AND METHODS: 56 patients with advanced OSCC, 21 patients with intraepithelial neoplasia (IEN), 56 patients with a background of non-neoplastic epithelium, adjacent to the OSCC, and 42 normal control epithelia from healthy volunteers were studied. The promoter methylation status of SFRP1, SFRP2, DCC, APC, p16(INK4a), p14(ARF), MINT1, MINT2, MINT31, CACNA1G, COX2, DAPK, hMLH1 and MGMT was examined by methylation-specific single polymerase chain reaction or combined bisulphite restriction analysis. The mutation of p53 by direct sequencing was assessed. RESULTS: DNA methylation was observed in OSCC and in its background epithelium. The frequency of CpG island methylation increased from a baseline level in the background non-neoplastic epithelium, through IEN, to advanced OSCC. However, mutations in p53 were almost exclusively observed in IEN and OSCC. More extensive DNA methylation was seen in the neoplastic lesions (OSCC or IEN) having a p53 mutation than in those with wild-type p53. CONCLUSION: DNA methylation is present at low levels in the non-neoplastic oesophageal epithelium and appears to contribute to the progression of the dysplasia-carcinoma sequence in OSCC carcinogenesis.

Adult↗

PubMed2006

Cyclooxygenase-2 mediates the development of cortical spreading depression-induced tolerance to transient focal cerebral ischemia in rats.

We examined the role of cyclooxygenase-2 in the development of ischemic tolerance induced by cortical spreading depression against transient, focal brain ischemia. Cortical spreading depression was continuously induced for 2 h with topical KCl (13+/-1 depolarizations/2 h) in male Wistar rats. At 1, 2, 3, 4, and 5 days following recovery, the middle cerebral artery was transiently occluded for 120 min. Four days later, the animals were killed and infarct volume was determined. Additionally, cyclooxygenase-2 levels in the cerebral cortex and 15 deoxy-Delta(12, 14) PGJ2 levels in cerebrospinal fluid were determined at these times with Western blotting and immunoassay, respectively. Infarct volume was reduced compared with non-cortical spreading depression control animals (274.3+/-15.3 mm3) when cortical spreading depression was performed 3 and 4 days before middle cerebral artery occlusion (163.9+/-14.2 mm3, 154.9+/-14.2 mm3) but not at 1, 2 and 5 days (280.4+/-17.3 mm3, 276.3+/-16.9 mm3 and 268.5+/-17.3 mm3). Cyclooxygenase-2 levels increased most dramatically starting at 2 days, peaked at 3 days, and started to return toward baseline at 4 days after cortical spreading depression. 15 Deoxy-Delta(12, 14) PGJ2 levels increased from 134.7+/-83 pg/ml at baseline to 718+/-98 pg/ml at 3 days. Administration of N-[2-cyclohexyloxy-4-nitrophenyl] methanesulphonamide (10 mg/kg, i.v.), a selective cyclooxygenase-2 inhibitor, at 1 h prior to middle cerebral artery occlusion in cortical spreading depression preconditioned animals did not affect infarct volume (162.6+/-62.1 mm3). However, administration of N-[2-cyclohexyloxy-4-nitrophenyl] methanesulphonamide given three times prior to middle cerebral artery occlusion prevented the reduced infarct volume induced by cortical spreading depression preconditioning (272.9+/-63.2 mm3). Administration of L-nitro-arginine methyl ester (4 mg/kg, i.v.) prior to cortical spreading depression blocked increases in cyclooxygenase-2 normally seen at 3 and 4 days. We conclude that NO-mediated cyclooxygenase-2 upregulation by cortical spreading depression protects the brain against ischemic damage.

Animals↗

PubMed2006

Serum levels of 8-isoprostane, a marker of oxidative stress, are elevated in patients with systemic sclerosis.

OBJECTIVE: To determine serum levels and clinical correlation of 8-isoprostane, which is produced in vivo through free radical-catalysed peroxidation of arachidonic acid and reflects oxidative stress, in patients with systemic sclerosis (SSc). METHODS: Serum 8-isoprostane levels from 32 patients with diffuse cutaneous SSc (dSSc) and 25 patients with limited cutaneous SSc (lSSc) were examined by enzyme-linked immunosorbent assay. RESULTS: Serum 8-isoprostane levels were elevated in dSSc and lSSc patients by 75-fold compared with normal controls (n=32). Serum 8-isoprostane levels correlated negatively with pulmonary function, such as percentage vital capacity and diffusion capacity for carbon monoxide, and correlated positively with renal vascular damage determined by colour flow Doppler ultrasonography. Serum 8-isoprostane levels also correlated positively with serum levels of IgG and anti-agalactosyl IgG autoantibody. CONCLUSION: Increased 8-isoprostane levels correlated with the severity of pulmonary fibrosis, the extent of renal vascular damage and immunological abnormalities in SSc, suggesting that enhanced oxidative stress is related to the development of SSc.

Adult↗

PubMed2006

Transoral anterior approach for extensive anterior decompression at the C3 vertebra level in a patient with severe atlantoaxial vertical subluxation and rheumatoid arthritis.

STUDY DESIGN: We report a successful extensive transoral anterior decompression for an elderly patient with myelopathy and occipitalgia due to severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with rheumatoid arthritis (RA). OBJECTIVE: To describe the treatment of an exceptional pathological condition involving severe vertical subluxation. SETTING: University-affiliated hospital in Gifu, Japan. METHODS: A 73-year-old woman was referred to our clinic because of myelopathy and occipitalgia due to severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with RA. Plain radiographs revealed severe atlantoaxial vertical subluxation and sagittal magnetic resonance (MR) imaging revealed severe compression of the spinal cord at the level of the C2/3 disc space due to both posterior subluxation of C2 and rheumatoid pannus at the C2/3 disc space. As MR images demonstrated that the C2/3 disc space was located just behind the retropharyngeal wall, we performed successful anterior decompression from C2 to C3 via the standard transoral approach without mandibular osteotomy. RESULTS: The patient has been followed for 4 years and her symptoms are currently much improved without further surgical treatment. CONCLUSIONS: The present case illustrates that severe atlantoaxial vertical subluxation and posterior subluxation of the axis associated with RA can be treated successfully by anterior decompression of C2 and C3 via the standard transoral approach.

Aged↗

PubMed2006

Role of prostaglandin D2 and E2 terminal synthases in chronic rhinosinusitis.

BACKGROUND: Prostaglandin (PG)D(2) and E(2), two major cyclooxygenase (COX) products, are generated by PGD(2) synthase (PGDS) and PGE(2) synthase (PGES), respectively, and appear to mediate airway inflammation. OBJECTIVE: We sought to determine the role of PGDS and PGES in the pathophysiology of chronic rhinosinusitis (CRS). METHODS: The study examined the expression of PGDS and PGES in nasal polyps of 22 CRS patients. As controls, uncinate process mucosae were obtained from 12 CRS patients not having nasal polyps and five subjects without sinusitis. Immunohistochemistry and quantitative real-time PCR were used to evaluate the expression. RESULTS: Both PGDS and PGES were detected in nasal polyps by immunohistochemistry. Significantly greater levels of PGDS mRNA and lesser levels of PGES mRNA were observed in the nasal polyps as compared with uncinate process mucosae, and an inverse correlation between PGDS and PGES expression was observed. Levels of PGDS mRNA in nasal polyps were positively correlated with degree of infiltration by EG2+ eosinophils, whereas the levels of PGES were inversely correlated. Significantly increased levels of PGDS and conversely decreased levels of PGES were observed in asthmatics as compared with non-asthmatics. In addition, PGDS and PGES levels were positively and inversely correlated with the radiological severity of sinusitis, respectively. CONCLUSIONS: These results suggest that PGDS and PGES display an opposite and important role in the pathophysiology of CRS such as polyp formation, and more specifically, a biased expression of these synthases might contribute to the development of CRS by affecting eosinophilic inflammation.

Adolescent↗

PubMed2006

Detection of a 5' end subgenome of hepatitis C virus terminating at nucleotide 384 in patients' plasma and liver tissues.

Quadri and Negro [Dig Liver Dis 2001; 33: 480] reported greater distribution of 5' end genomic RNA of hepatitis C virus (HCV) over its 3' end in the liver of patients with recurrent hepatitis C after liver transplantation. We not only confirmed their results by quantifying the 5' end subgenomes in various specimens by using dilution and real-time polymerase chain reaction methods, but also discovered that such subgenomes terminated at nucleotide (nt) 384 of the viral genome or in its immediate upstream. The subgenomes in the plasma uniformly, with a few exceptions, ended at this position, while those in the liver more heterogeneously at various points upstream of nt 384. Subgenome populations ending some points in the downstream of nt 384 were not detected. The amount of the 5' end subgenome, while fluctuating during the clinical course of the patients, exceeded that of the longer sized HCV genomes which included the intact genome, and, when the relative ratio of the 5' end subgenome increased, the amount of longer sized HCV RNA tended to decrease, suggesting a suppressive effect of the 5' end subgenome on viral replication.

Alanine Transaminase↗

PubMed2006

Prognostic significance of CDC25B expression in gliomas.

BACKGROUND: CDC25B is a cell-cycle regulatory protein, which is considered to be related to tumorigenesis and progression of tumours. AIMS: To elucidate the role of CDC25B in glioma, the expression of CDC25B and the association of the CDC25B expression with the clinicopathological parameters were investigated. METHODS: Fifty seven gliomas, which included 21 low-grade astrocytomas, 17 anaplastic astrocytomas and 19 glioblastomas, were studied. Protein expressions of CDC25B were evaluated by immunohistochemical methods. Semiquantitative and real-time RT-PCR analyses for the expression of CDC25B mRNA were also carried out. Disease-free survival (DFS) data were analysed by using the Kaplan-Meier method. RESULTS: High expression of CDC25B was identified in 18 of the 19 glioblastomas, in 10 of the 17 anaplastic astrocytomas, but not in any of the 21 low-grade astrocytomas. The CDC25B mRNA expression increased with the rise in histological grade. Increased CDC25B expression was correlated significantly with a shorter period of DFS, as shown by multivariate analysis. CONCLUSIONS: Patients with an unfavourable clinical outcome are characterised by the increased expression of CDC25B in their glioma samples. Useful clinical information, especially on its relevance as a prognostic indicator, is provided by the evaluation of CDC25B expression in gliomas.

Adult↗

PubMed2006

Upper airway obstruction caused by ingestion of concentrated acetic acid.

We report a case of rapidly progressive severe upper airway obstruction in a small child caused by accidental ingestion of 80% acetic acid. Emergency cricothyrotomy was necessary after both endotracheal intubation and bag-valve-mask ventilation were not possible. Although intubation was eventually achieved, a tracheostomy was necessary. Toxin spilled over the anterior chest and abdomen caused third degree skin burns which required grafting. Mild liver dysfunction was observed. Complete recovery occurred.

Acetic Acid↗

PubMed2006

[Aortic valve replacement for calcified aortic valve and annulus with ultrasonic decalcification].

UNLABELLED: We conducted ultrasonic decalcification on calcified annulus in patients with aortic stenosis (AS) using an ultrasonic operator, Sonopet (UST 2001) prior to aortic valve replacement (AVR). We studied the reliability of this method. SUBJECT AND METHOD: From January 2002 to August 2005, AVR was conducted for AS using the Sonopet in 45 patients, comprising of 18 male and 27 female subjects. The mean age was 73.3 +/- 9.7. RESULT: Artificial valves were successfully inserted at the intra-annular level in 37 patients and at the supra-annular level in 8 patients without conducting annular enlargement. In the patients with narrow annuli of less than 19 mm (23 patients), the preoperative mean annular diameter was 18.2 +/- 1.0 mm, but significantly larger artificial valves with an average diameter of 19.3 +/- 1.5 mm (p=0.003) were successfully inserted. CONCLUSION: AVR was proved to be safe and easy by previous ultrasonic decalcification of the annuls using the Sonopet. This method was very useful because it required no enlargement of aortic annulus.

Aged↗

PubMed2006

[Off-pump coronary artery bypass in high-risk patients].

In this study, 110 consecutive patients who had undergone off-pump coronary artery bypass (OPCAB) in the past 2 years were evaluated for early results of OPCAB. Patients were classified as a high-risk group (H group: 68 patients consisting of 46 men and 22 women) and a low-risk group (L group: 42 patients consisting of 31 men and 11 women), respectively, and were evaluated for the early operative results. No differences were noted between the H and L groups in the mean number of bypass grafts (2.9 +/- 0.9 in the H group, 2.9 +/- 0.9 in the L group), the rates of complete revascularization (85% in the H group, 93% in the L group), those of various graft materials bypassed, or those of sequential bypass. In all patients, we were able to undergo coronary revascularization by the aortic no-touch technique using arterial grafts exclusively. In the H group, 1 patient (1.5%) died in hospital, but no patients developed cerebral infarction postoperatively, and the frequency of complications was similar to that in the L group. The results of OPCAB for high-risk patients were good, and it was suggested that OPCAB using in situ arterial grafts was very useful particularly in patients with cerebrovascular diseases.

Aged↗

PubMed2006

[Lung cancer associated with bulla found during an operation of pneumothorax; report of a case].

A 50-year-old man was admitted to our hospital because of dyspnea. His chest X-ray and computed tomography (CT) showed right pneumothorax and multiple bullae. His pneumothorax was drained with a chest tube, however, because of a persistent air leak, bullectomy was performed 18 days after the occurrence of pneumothorax. Intraoperatively, we found a palpable tumor in the bulla approximately 10 mm in diameter and resected it with the bullae. Histologically, the tumor was diagnosed as a large cell carcinoma.

Blister↗

PubMed2005

Predicting hydration free energies of neutral compounds by a parametrization of the polarizable continuum model.

A parametrization of the polarizable continuum model (PCM) is presented having the experimental hydration free energies of 215 neutral molecules as target. The cavitation and dispersion contributions were based on the Tuñon-Silla-Pascual-Ahuir (Tuñon; et al. Chem. Phys. Lett. 1993, 203, 289) and Floris-Tomasi (Floris, F.; Tomasi, J. J. Comput. Chem. 1989, 10, 616) expressions, respectively. Both the polar and nonpolar contributions were evaluated on the same solvent-excluding molecular surface that used unscaled Bondi atomic radii. The parametrization was provided for the HF, Xalpha, LSDA, B3LYP, and mPW1PW91 methods at the 6-31G(d) basis set, and the results are in fair agreement with the experimental data. For the sake of comparison, the PCM(UAHF) and our parametrization (PCM2), both at HF level, have produced DeltaG(PCM(UAHF)) = aDeltaGexp (a = 1.02 +/- 0.02, r = 0.945, sd = 0.987, Ftest = 1778) and DeltaG(PCM2) = aDeltaGexp (a = 0.95 +/- 0.02, r = 0.952, sd = 0.843, Ftest = 2070), respectively. The mean absolute deviations from experimental data were 0.67 and 0.68 kcal/mol for PCM(UAHF) and PCM2, respectively.

Journal Article↗