Biomedical subjects

S Furukawa

Publications and source records attributed to S Furukawa.

At least 37 records · Page 2Linked to original sources

PubMed2003

Washout measurement of radioisotope implanted by radioactive beams in the rabbit.

Washout of 10C and 11C implanted by radioactive beams in brain and thigh muscle of rabbits was studied. The biological washout effect in a living body is important in the range verification system or three-dimensional volume imaging in heavy ion therapy. Positron emitter beams were implanted in the rabbit and the annihilation gamma-rays were measured by an in situ positron camera which consisted of a pair of scintillation cameras set on either side of the target. The ROI (region of interest) was set as a two-dimensional position distribution and the time-activity curve of the ROI was measured. Experiments were done under two conditions: live and dead. By comparing the two sets of measurement data, it was deduced that there are at least three components in the washout process. Time-activity curves of both brain and thigh muscle were clearly explained by the three-component model analysis. The three components ratios (and washout half-lives) were 35% (2.0 s), 30% (140 s) and 35% (10 191 s) for brain and 30% (10 s), 19% (195 s) and 52% (3175 s) for thigh muscle. The washout effect must be taken into account for the verification of treatment plans by means of positron camera measurements.

Animals↗

PubMed2003

Voxel-based analysis of MRI reveals anterior cingulate gray-matter volume reduction in posttraumatic stress disorder due to terrorism.

MRI studies using the manual tracing method have shown a smaller-than-normal hippocampal volume in patients with posttraumatic stress disorder (PTSD). However, these studies have yielded inconsistent results, and brain structures other than the hippocampus have not been well investigated. A recently developed, fully automated method called voxel-based morphometry enables an exploration of structural changes throughout the brain by applying statistical parametric mapping to high-resolution MRI. Here we first used this technology in patients with PTSD. Participants were 9 victims of the Tokyo subway sarin attack with PTSD and 16 matched victims of the same traumatic event without PTSD. The voxel-based morphometry showed a significant gray-matter volume reduction in the left anterior cingulate cortex (ACC) in trauma survivors with PTSD compared with those without PTSD. The severity of the disorder was negatively correlated with the gray-matter volume of the left ACC in PTSD subjects. There were no significant differences in other gray-matter regions or any of the white-matter regions between two groups. The present study demonstrates evidence for structural abnormalities of ACC in patients with PTSD. Together with previous functional neuroimaging studies showing a dysfunction of this region, the present findings provide further support for the important role of ACC, which is pivotally involved in attention, emotional regulation, and conditioned fear, in the pathology of PTSD.

Adult↗

PubMed2003

Cerebral imaging by magnetic resonance imaging and single photon emission computed tomography in systemic lupus erythematosus with central nervous system involvement.

OBJECTIVE: To assess the significance of magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) abnormalities in patients with systemic lupus erythematosus (SLE). METHODS: Forty-four patients with SLE were retrospectively analysed. Patients were classified into three groups [1 and 2: patients with central nervous system (CNS) manifestations before and after starting high-dose steroid therapy, respectively; 3: patients without CNS manifestations. MRI was performed in all 44 patients and SPECT in 31. RESULTS: Abnormal findings in MRI were found in 19 patients. MRI abnormalities were significantly more frequent in patients with CNS manifestations than in those without [71 vs 17%, odds ratio (OR) 11.9, confidence interval (CI) 2.8-49.9, P=0.0003]. After the initiation of steroid therapy, patients with CNS manifestations also had an increased frequency of abnormal MRI. No correlation was found between SPECT findings and CNS manifestations. However, patients with CNS manifestations after starting steroids showed a markedly increased frequency of abnormal MRI and SPECT compared with those without CNS manifestations (80 vs 7%; OR 56, CI 4.4-719, P=0.0003). The positive predictive value of abnormality in both techniques in developing CNS manifestations after starting steroids was 89%. CONCLUSION: MRI findings correlated with CNS manifestations in SLE. Where there is a high suspicion of CNS involvement, the combination of MRI and SPECT may be useful in predicting CNS manifestations after starting steroid therapy.

Adolescent↗

PubMed2003

Materno-fetal coordination of stress-induced Fos expression in the hypothalamic paraventricular nucleus during pregnancy.

This study investigates whether maternal stress during pregnancy induces maternal and fetal hypothalamic paraventricular nucleus (PVN) neuronal activation and the effects of maternal stress on fetal hypothalamic and PVN brain-derived neurotrophic factor (BDNF) expression. Pregnant rats were exposed to three types of maternal stress with varying severity (restraint, forced walking and immobilization) for 30 min on gestational day 21. Severity of stress was assessed by measurement of maternal plasma corticosterone 30 min following the stimulus. Maternal plasma corticosterone increased in each stress response group (immobilization>forced walking>restraint). Further, the expression of Fos protein, a marker of neuronal activation, increased in the fetal and maternal PVN in direct relation to the severity of stress treatments. Forced walking and immobilized stress, but not restraint stress, significantly increased BDNF expression in the fetal hypothalamus.These findings suggest that the fetal hypothalamic-pituitary-adrenal (HPA) response following maternal stress mirrors maternal HPA activation. In addition, BDNF may play a role in protecting fetal brain neurons from damage caused by severe stress.

Animals↗

PubMed2003

Pharmacologic pre-conditioning and controlled reperfusion prevent ischemia-reperfusion injury after 30 minutes of hypoxia/ischemia in porcine hearts.

BACKGROUND: Hearts from non-heart-beating organ donors are not transplanted because of risk of ischemia-reperfusion injury. We tested whether pharmacologic pre-conditioning with adenosine and the Na(+)/H(+) exchanger inhibitor, cariporide, combined with controlled reperfusion, would prevent injury in porcine hearts that had sustained 30 minutes of hypoxia/ischemia in closed-chest animals. METHODS: Hearts from Yorkshire pigs (100 kg) were studied in 3 groups. Group 1 (control) hearts were surgically removed while beating. Group 2 hearts were harvested from animals made hypoxic by discontinuing mechanical ventilation for 30 minutes. Group 3 hearts were hypoxic as in Group 2, but these animals received adenosine (40 mg) and cariporide (400 mg) 10 minutes before stopping ventilation. Cardiac function in all groups was assessed ex vivo in a working heart apparatus in which pressure and flow measurements were made over 3 hours. Controlled reperfusion in Group 3 hearts used leukocyte-depleted blood perfusate containing free radical scavengers. Myocardial injury was assessed on the basis of perfusate creatine phosphokinase activity and histopathologically determined injury score. RESULTS: Groups 1 and 3 hearts could be resuscitated to perform work equivalently during the entire reperfusion period and showed positive responses to increases in pre-load and norepinephrine. Group 2 hearts could not perform work. After 3 hours, Group 2 hearts showed significantly higher creatine phosphokinase and histopathologic injury scores compared to with Groups 1 and 3, which were not significantly different from each other. CONCLUSIONS: Pharmacologic pre-conditioning and controlled reperfusion effectively protect non-beating porcine hearts from injury after 30 minutes of hypoxia/ischemia in situ.

Adenosine↗

PubMed2003

Pranlukast inhibits NF-kappa B activation in human monocytes/macrophages and T cells.

BACKGROUND: Pranlukast is a leukotriene 1 (LT1) receptor antagonist and is effective against bronchial asthma. Pranlukast inhibits contraction of the tracheal muscle, and thereby antagonizes the binding of LTC4, LTD4 and LTE4. However, the action of pranlukast on monocytes/macrophages and T cells is unknown. OBJECTIVE: We examined whether or not pranlukast inhibits TNF-alpha-induced activation of nuclear transcription factor NF-kappa B, a factor that is essential for the expression of proinflammatory cytokines, on human monocytic 1.3% dimethylsulphoxide (DMSO)-differentiated U-937 cells, which have cysteinyl LT1 (CysLT1) receptors on their membranes, and T cells (Jurkat), which do not. METHODS: We examined whether or not LTC4, LTD4 or LTE4 induced NF-kappa B activation in 1.3% DMSO-differentiated U-937 cells by Western blotting. The inhibitory effects of pranlukast and MK-571, which is an LTD4 receptor-selective antagonist, on TNF-alpha-induced NF-kappa B activation was evaluated by Western blotting and flow cytometry, and those on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) production in peripheral blood mononuclear cells (PBMC) were evaluated by enzyme-linked immunosorbent assaying. RESULTS: LTC4, LTD4 or LTE4 did not induce NF-kappa B activation in 1.3% DMSO-differentiated U-937 cells. Western blotting demonstrated that 10-5 M pranlukast inhibits NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells by about 40% & 30%, respectively. Flow cytometry demonstrated that pranlukast and MK-571 inhibit NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells in a dose-related manner. Moreover, 10-5 M pranlukast and MK-571 inhibited LPS-induced IL-6 production in PBMC by about 65% and 15%, respectively. CONCLUSION: Pranlukast and MK-571 partially inhibited NF-kappa B activation in 1.3% DMSO-differentiated U-937 and Jurkat cells, and IL-6 release in PBMC. These findings are consistent with the idea that, independently of CysLT1 receptor antagonism, micromolar concentrations of pranlukast suppress the production of proinflammatory cytokines via inhibition of NF-kappa B activation in monocytes/macrophages and T cells, but the contribution of this effect to the anti-inflammatory activity of pranlukast at oral therapeutic doses in asthmatic patients is unclear.

Chromones↗

PubMed2003

CTLA-4 (CD152) expression in peripheral blood T cells in Kawasaki disease.

Kawasaki disease (KD) is an acute febrile illness of early childhood caused by vasculitis. Whether or not peripheral blood T cells are activated in acute KD remains uncertain, as some reports have presented evidence of peripheral blood T cell activation, whereas others suggest that the level of peripheral blood T cell activation is low during acute KD. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4, CD152) is a surface molecule of activated T cells. We therefore investigated intracellular CTLA-4 expression in the peripheral blood T cells of patients with acute KD as a marker of T cell activation. We collected blood samples from 20 patients with KD and six with Epstein-Barr virus infectious mononucleosis (EBV-IM) who were admitted to our hospital, as well as 13 healthy children. We determined the intracellular expression of CTLA-4 in T cells by flow cytometry. We demonstrated that the intracellular expression of CTLA-4 is up-regulated in peripheral blood CD3+ T cells, CD4+ T cells and CD8+ T cells at the early part of the acute stage in KD. However, the mean percentages of intracellular T cells expressing CTLA-4 in EBV-IM patients were about fourfold higher than those in T cells from patients with acute KD. Our results suggested that the level of activation of peripheral blood T cells is very low during acute KD.

Abatacept↗

PubMed2003

NF-kappaB activation in peripheral blood mononuclear cells in neonatal asphyxia.

Neonatal asphyxia results in hypoxic-ischaemic encephalopathy. Previous studies have demonstrated that brain hypoxia and ischaemia lead to the production of proinflammatory cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and IL-6. Transcription factor NF-kappaB is essential for the expression of these cytokines. We examined whether or not NF-kappaB is activated in peripheral mononuclear cells (PBMC) in neonatal asphyxia by flow cytometry. In addition, we examined the relationship between NF-kappaB activation in PBMC and the neurological prognosis. Flow cytometry analysis demonstrated that the level of NF-kappaB activation in CD14+ monocytes/macrophages of the patients with asphyxia who had neurological sequelae was significantly higher than in the controls, and in the patients with asphyxia who survived (31.7 +/- 7.2%versus 2.5 +/- 0.9%, P = 0.008, and versus 1.6 +/- 1.4%, P = 0.014, respectively). Our findings suggest that NF-kappaB activation in peripheral blood CD14+ monocytes/macrophages in neonatal asphyxia is important for predicting the subsequent neurological sequelae.

Asphyxia Neonatorum↗

PubMed2003

Mechanism of the inactivation of bacterial spores by reciprocal pressurization treatment.

AIMS: The mechanism of the inactivation of Bacillus subtilis spores by reciprocal pressurization (RP) was unclear. Therefore, the mechanism was investigated. METHODS AND RESULTS: To investigate the effects of RP and continuous pressurization (CP) treatments on the inactivation and injury of B. subtilis spores, spores were treated at 25, 35, 45 and 55 degrees C under 200, 300 and 400 MPa. RP treatment was effective in injuring and inactivating spores. Scanning electron microscopy and transmission electron microscopy observation showed that spores treated by RP treatment were more morphologically and structurally changed than the ones treated by CP treatment. There were significant differences between the release of dipicolinic acid (pyridine-2,6-dicarboxylic acid) by RP and CP treatments. From this result, it was concluded that the core fraction was released into the spore suspension. CONCLUSIONS: The mechanism of RP treatment is believed to work as follows: hydrostatic pressure treatment initiated germination of bacterial spores, and the repeated rapid decompression caused disruption, injury and inactivation of the germinated spores. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicated that the physical injury of bacterial spores was effective to inactivate the bacterial spores through the disruption of spores and leakage of their contents.

Bacillus subtilis↗

PubMed2003

Bilateral multiple pulmonary metastases in a patient with double advanced cancer of the head and neck.

A case of advanced gingival cancer is described. The cancer invaded into the mandible and skin of the cheek and was associated with cervical lymph node metastases, mediastinal lymph node metastases, and bilateral multiple pulmonary metastases. The patient received neoadjuvant chemoradiotherapy and local immunotherapy, followed by curative surgery for the primary and neck lesions. Histopathological examination of the primary cancer and the upper and middle cervical nodes (n = 7) indicated a diagnosis of squamous cell carcinoma. Sections of the lower cervical nodes (n = 5) revealed well-differentiated thyroid carcinoma, suggesting that the mediastinal and pulmonary lesions were of thyroid origin. After total thyroidectomy and mediastinal dissection followed by treatment with radioiodine, the multiple pulmonary nodules disappeared. There has been no evidence of recurrent tumour for 5 years.

Adult↗

PubMed2002

Tuning of electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron-correlation by doping of Co(III) ions, [Ni(1-x)Co(x)(Chxn)(2)Br]Br(2).

We have succeeded in synthesizing the Ni(III) complexes doped by Co(III) ions, [Ni(1-x)Co(x)(chxn)(2)Br]Br(2) (x = 0, 0.043, 0.093, and 0.118) by using an electrochemical oxidation method. The single-crystal reflectance spectrum of x = 0.118 shows an intense CT band about 0.5 eV, which is lower than that of [Ni(chxn)(2)Br]Br(2) (1.3 eV). The single-crystal electrical conductivities at room temperature of these compounds increase with increase of the amounts of doping of Co(III) ions. In the ESR spectra, peak-to-peak line widths DeltaH(pp) at room temperature change about 600 G in [Ni(chxn)(2)Br]Br(2) to 200 G in x = 0.118. Such a large x dependence of DeltaH(pp) seems to be ascribed to the increasing contribution from the increasing Curie spins which have smaller line width. Therefore, we have tuned the electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron correlations by doping of Co(III) ions.

Journal Article↗

PubMed2002

The relationship of psychopathology and hyperhidrosis.

BACKGROUND: Hyperhidrosis is a common yet poorly understood disease that is often exacerbated by emotional stress. While a psychiatric explanation of causality is frequently offered, there is little evidence to support or reject the view that the condition is primarily an anxiety-based disorder. OBJECTIVES: To quantify objectively the degree of psychopathology in patients with hyperhidrosis. METHODS: Forty-two patients diagnosed as having hyperhidrosis were examined prior to endoscopic sympathectomies. All patients took the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and State-Trait Anxiety Inventory (STAI) before surgery. Results were compared with established norms. RESULTS: The group scored well within established norms on both psychometric measures. On scales measuring anxiety, depression and conversion phenomena, 88% of the MMPI-2 profiles lacked elevations, and 86% of the patients lacked elevations on the STAI State and Trait Anxiety scales. Personality variables were not associated with postsurgical outcome. CONCLUSIONS: Most individuals suffering from essential hyperhidrosis lack overt psychopathology. While some patients subjectively describe symptoms of anxiety, mild depression and social isolation, these complaints appear often to be in reaction to or superimposed upon an organic disease process and not the primary cause of their condition.

Adolescent↗

PubMed2002

Lung herniation as an anatomic consequence of pneumonectomy.

BACKGROUND: Pneumonectomy causes an overdistention of the remaining lung as an adaptive response. Excessive lung herniation occasionally causes serious lung dysfunction. METHODS: Twenty-seven patients were selected from 152 patients who underwent pneumonectomy for lung cancer between 1990 and 1998. Complete resections were accomplished; no recurrence was observed for 3 years in these 27 patients. To evaluate the extent of herniation, the Lung Herniation Index (LHI) was developed and defined as the sum of proportions of the maximal transverse length of the remaining lung divided by the transverse length of the thoracic cavity, measured at the level of the aortic arch and the inferior pulmonary vein on chest computed tomography. Sequential changes in LHI were compared between groups. RESULTS: Changes in LHI did not differ between groups delineated on the basis of an FEV1 of 70 % (p = 0.45) and RV/TLC of 40 % (p = 0.99). Patients with a low body mass index (BMI) (< 20 kg/m(2)), however, showed a significantly greater degree of lung herniation than those with a high BMI (> or = 20 kg/m(2)) (p < 0.05). CONCLUSIONS: Concomitant COPD has no effect on lung herniation. Some preventive procedure should be considered for patients with low BMI.

Adult↗

PubMed2002

Human masticatory muscle volume and zygomatico-mandibular form in adults with mandibular prognathism.

Although several investigators have reported associations between masticatory muscles and skeletal craniofacial form, there is no agreement on the association. We tested the hypothesis that masticatory muscle volume correlates with the size and form of the adjacent local skeletal sites. For this purpose, we investigated the morphological association of the cross-sectional area and volume of temporal and masseter muscles with zygomatico-mandibular skeletal structures using computerized tomography (CT) in 25 male adults with mandibular prognathism. Muscle variables significantly correlated with widths of the bizygomatic arch and temporal fossa but not with the cranium width. Masseter volume significantly correlated with cross-sectional areas of the zygomatic arch and mandibular ramus. Masseter orientation was almost perpendicular to the zygomatic arch and mandibular antegonial region. The zygomatic arch angle significantly correlated with the antegonial angle. The results of the study suggest that the masticatory muscles exert influence on the adjacent local skeletal sites.

Adolescent↗

PubMed2002

Development of a simulator for ozone/UV reactor based on CFD analysis.

A new CFD (Computational Fluid Dynamics) simulator for an O3/UV reactor where ozone dissolved water flows under the irradiation of UV, has been developed by combining a fluid dynamics model with a complex radical reaction model. The radical reaction model used in this simulator was found to be reasonable, because the results obtained from the simulation of a completely stirred tank reactor (CSTR) system were in good agreement with the experimental results, e.g., the concentrations of total organic carbon (TOC), hydrogen peroxide and dissolved ozone obtained from a lab-scale CSTR. Furthermore, by using this CFD simulator, the distributions of substances such as hydroxyl radical (OH*) and hydrogen peroxide in the O3/UV reactor have been investigated. These distributions showed that this CFD simulator was considered to be reasonable. In addition, the simulation results suggested that conventional reactors were not optimized.

Computer Simulation↗

PubMed2001

Transforming growth factor-beta1 enhances expression of brain-derived neurotrophic factor and its receptor, TrkB, in neurons cultured from rat cerebral cortex.

The effects of transforming growth factor (TGF)-beta1 on expression of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, TrkB, in neurons cultured from the cerebral cortex of 18-day-old embryonic rats were examined. BDNF mRNA was significantly increased from 24-48 hr after the TGF-beta1 treatment over 20 ng/ml. Accumulation of BDNF protein in the culture medium was also potentiated by TGF-beta1, although the intracellular content of BDNF was nearly unchanged. The enhancement of BDNF mRNA expression was suppressed by the co-presence of decorin, a small TGF-beta-binding proteoglycan that inhibits the biological activities of TGF-betas. mRNA expression of full-length TrkB, the bioactive high-affinity receptor for BDNF, was also upregulated after treatment with TGF-beta1. These observations suggest that: 1) TGF-beta1 potentiates BDNF/TrkB autocrine or local paracrine system; and 2) the neurotrophic activity of TGF-beta1 is partly responsible for the BDNF induced by TGF-beta1 itself. To test this latter possibility, we examined the neuronal survival activity of TGF-beta1 with or without K252a, a selective inhibitor of Trk family tyrosine kinases. TGF-beta1 significantly enhanced neuronal survival, but the co-presence of K252a completely suppressed the activity, demonstrating the involvement of Trk receptor signaling in TGF-beta1-mediated neuronal survival in cultured rat cortical neurons. These results seem to be in line with recent findings by other investigators that some neurotrophic factors including BDNF require TGF-betas as a cofactor to exert their neurotrophic activities.

Animals↗

PubMed2001

Phase III trial of high- vs. low-dose-rate interstitial radiotherapy for early mobile tongue cancer.

PURPOSE: Early mobile tongue cancer can be controlled with interstitial radiotherapy (ISRT). We carried out a Phase III trial to compare the treatment results of low-dose-rate (LDR) ISRT and high-dose-rate (HDR) ISRT for early mobile tongue cancer. METHODS AND MATERIALS: From April 1992 through October 1996, 59 patients with cancer of the early mobile tongue were registered in this Phase III study. Eight patients were excluded from the evaluation because of violations of the requirements for this study. Of 51 eligible patients, 26 patients were treated with LDR-ISRT (70 Gy/4-9 days) and 25 patients with HDR-ISRT (60 Gy/10 fractions/1 week). For the hyperfractionated HDR-ISRT, the time interval between 2 fractions was more than 6 h. RESULTS: Five-year local control rates of the LDR and HDR groups were 84% and 87% respectively. Nodal metastasis occurred in 6 patients in each group. Five-year nodal control rates of the LDR and HDR groups were 77% and 76%, respectively. CONCLUSION: Hyperfractionated HDR-ISRT for early mobile tongue cancer has the same local control compared with continuous LDR-ISRT. Hyperfractionated HDR-ISRT is an alternative treatment for continuous LDR-ISRT.

Adult↗

PubMed2001

Thiopental inhibits NF-kappaB activation in human glioma cells and experimental brain inflammation.

Thiopental is one of the intravenous anesthetics used widely. Several reports have demonstrated that thiopental inhibits the immune responses. We investigated whether or not thiopental inhibits the production of tumor necrosis factor-alpha (TNF-alpha) induced by lipopolysaccharide (LPS) in human glioma cells (A-172). Moreover, we determined whether or not thiopental modulates activation of the transcription factor NF-kappaB, a factor that regulates expression of the genes that code for proinflammatory cytokines in A-172 cells and in experimental murine brain inflammation. Thiopental inhibited TNF-alpha production induced by LPS in A-172 cells. Electrophoretic mobility shift assays demonstrated that thiopental inhibited NF-kappaB activation induced by LPS in A-172 cells. In experimental murine brain inflammation induced by intracerebroventricular injection of LPS, intraperitoneal injection of thiopental inhibited NF-kappaB activation. Western blot analysis indicated that this inhibition was linked to preservation of IkappaBalpha protein expression in A-172 cells. The chloramphenicol acetyltransferase assay revealed that NF-kappaB-dependent reporter gene expression was suppressed in A-172 cells exposed to thiopental. These findings are consistent with the idea that thiopental exerts antiinflammatory effects in cultured cells and experimental murine brain inflammation, through suppression of TNF-alpha production via inhibition of NF-kappaB activation.

Anesthetics, Intravenous↗