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Biomedical subjects

Takeshi Fukuda

Publications and source records attributed to Takeshi Fukuda.

At least 37 records · Page 2Linked to original sources
PubMed2005

Postoperative cerebral hyperperfusion associated with impaired cognitive function in patients undergoing carotid endarterectomy.

OBJECT: Cognitive impairment occurs in 20 to 30% of patients following carotid endarterectomy (CEA). The purpose of the present study was to determine whether postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing that procedure. METHODS: Cerebral blood flow (CBF) was measured using single-photon emission computerized tomography scanning before and immediately after CEA and on the 3rd postoperative day in 92 patients with ipsilateral internal carotid artery stenosis of 70% or greater. Hyperperfusion post-CEA was defined as a 100% increase or greater in CBF compared with preoperative values. Neuropsychological testing was also performed preoperatively and at the 1-, 3-, and 6-month follow-up examinations. At the 1-month postoperative neuropsychological assessment, 11 patients (12%) displayed evidence of cognitive impairment. In addition, the incidence of postoperative cognitive impairment in patients with post-CEA hype perfusion (seven [58%] of 12 patients) was significantly higher than that in patients without post-CEA hyperperfusion (four [5%] of 80 patients; p < 0.0001). A logistic regression analysis demonstrated that post-CEA hyperperfusion was the only significant independent predictor of postoperative cognitive impairment. Of the seven patients in whom post-CEA hyperperfusion and cognitive impairment were identified 1 month postoperatively, four (including three patients with hyperperfusion syndrome) remained cognitively impaired at the 3- and 6-month follow-up examinations. CONCLUSIONS: Postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing CEA. Furthermore, the development of hyperperfusion syndrome is associated with the persistence of postoperative cognitive impairment.

Aged↗
PubMed2005

Cerebral hyperperfusion following carotid endarterectomy: diagnostic utility of intraoperative transcranial Doppler ultrasonography compared with single-photon emission computed tomography study.

BACKGROUND AND PURPOSE: Cerebral hyperperfusion syndrome is a rare but serious complication of carotid endarterectomy (CEA). The aim of the present study was to determine whether intraoperative blood flow velocity (BFV) monitoring in the middle cerebral artery (MCA) by using transcranial Doppler ultrasonography (TCD) could be used as a reliable technique to detect cerebral hyperperfusion following CEA by comparing findings with those of brain single photon emission CT (SPECT). METHODS: Intraoperative BFV monitoring was attempted in 67 patients undergoing CEA for treatment of ipsilateral internal carotid artery (ICA) stenosis (> or =70%). Cerebral blood flow (CBF) was also assessed using SPECT, which was performed before and immediately after CEA. RESULTS: Intraoperative BFV monitoring was achieved in 60 patients. Of the 60 patients, post-CEA hyperperfusion (CBF increase > or =100%, compared with preoperative values) was observed in six patients. The sensitivity, specificity, and positive predictive value of the BFV increases immediately after declamping of the ICA for detecting post-CEA hyperperfusion was 100%, 94% and 67%, respectively, with a cut-off point 2.0-fold that of preclamping BFV. The sensitivity and specificity of the BFV increases at the end of the procedure for detecting post-CEA hyperperfusion were 100% for both parameters, with cut-off points of 2.0- to 2.2-fold BFV of preclamping value. Hyperperfusion syndrome developed in two patients with post-CEA hyperperfusion, but intracerebral hemorrhage did not occur. In one of these two patients, BFV monitoring was not possible because of failure to obtain an adequate bone window. CONCLUSION: Intraoperative MCA BFV monitoring by using TCD is a less reliable method to detect cerebral hyperperfusion following CEA than postoperative MCA BFV monitoring, provided adequate monitoring can be achieved.

Aged↗
PubMed2005

[Legionnaires' disease with acute renal failure caused by Legionella pneumophilla serogroup 4].

A 77-year-old man who had fever and chest pain was admitted to a neighboring hospital on a diagnosis of pneumonia. Chest X-ray film finding deteriorated despite treatment with 2 g cefotaxime per day. Because of accompanying acute renal failure, he was transferred to our hospital. Hemodialysis with intravenous administration of erythromycin and meropenem resulted in recovery from acute renal failure, and his general condition improved. Because of liver dysfunction, erythromycin was changed to pazufloxacin. Although he was negative for Legionella urinary antigen determined with a rapid assay kit, Binax NOW, his serum titer for Legionella pneumophila serogroup 4 was elevated. Finally, a diagnosis of Legionnaires' disease caused by Legionella pneumophila serogroup 4 was established.

Acute Kidney Injury↗
PubMed2004

Highly versatile organostibine mediators for living radical polymerization.

A new versatile method for conducting living radical polymerization has been developed in which organostibines induce consecutive group-transfer radical reactions with alkenes. The method has been successfully applied, for the first time, to the controlled polymerization of both conjugated and unconjugated vinyl monomers, and the desired polymers with predetermined molecular weight and low polydispersity index were obtained in excellent yields. This characteristic feature of this method is exemplified in the first synthesis of block copolymers composed of conjugated and unconjugated monomers, which would be of great importance as functional smart organic nanomaterials.

Journal Article↗
PubMed2004

Leukotriene D4 stimulates collagen production from myofibroblasts transformed by TGF-beta.

BACKGROUND: Airway remodeling has an important role in the pathogenesis of bronchial asthma. Many mediators that influence the pathophysiology of bronchial asthma, especially cysteinyl leukotrienes (CysLTs) and TGF-beta1, are involved in airway remodeling. OBJECTIVE: To know whether TGF-beta1 alters fibroblast responsiveness to CysLTs, we examined the effects of leukotriene (LT) D4 on collagen production from fibroblasts and from myofibroblasts transformed by TGF-beta1. We also examined whether TGF-beta1 upregulates CysLT1 receptor (CysLT1R) expression in fibroblasts. METHODS: Concentrations of procollagen in the human fetal lung fibroblast (HFL) 1 cell supernatant were measured by using an enzyme immunoassay kit in the presence or absence of various concentrations of LTD4, TGF-beta1, CysLT1R antagonist, or some combination of these. The mRNA expression of CysLT1R and alpha-smooth muscle actin as a marker of myofibroblasts was measured by means of real-time PCR. Furthermore, protein expression of CysLT1R on fibroblasts was measured by means of flow cytometric analysis. RESULTS: TGF-beta1 stimulated collagen production from HFL-1 cells, but LTD4 alone did not. LTD4 in combination with TGF-beta1 increased collagen production compared with TGF-beta1 alone. Real-time PCR showed that stimulation with TGF-beta1 significantly upregulated CysLT1R and alpha-smooth muscle actin mRNA expression in HFL-1 cells. CONCLUSIONS: LTD4 increased collagen production by upregulating CysLT1R induced by TGF-beta1. In the TGF-beta-rich milieu, activated myofibroblasts expressing CysLT1R can respond to CysLTs and produce large amounts of extracellular matrix, thereby contributing to airway remodeling. These data suggest that treatment with leukotriene receptor antagonists might prevent airway remodeling in patients with asthma.

Cell Division↗
PubMed2004

Intracerebral hemorrhage after carotid endarterectomy associated with asymptomatic perioperative cerebral ischemia detected by cerebral perfusion imaging: case report.

BACKGROUND: Risk factors for intracerebral hemorrhage following carotid endarterectomy (CEA) include perioperative cerebral ischemia, postoperative cerebral hyperperfusion, and postoperative anticoagulation therapy, and at least 2 of these risk factors are typically present in the context of intracerebral hemorrhage (ICH). CASE DESCRIPTION: A 75-year-old man with severe bilateral cervical internal carotid artery stenosis and a minor stroke resulting in left motor weakness underwent a right CEA. The operation was uneventful, and the patient did not experience new neurologic deficits upon recovery from anesthesia. Brain single photon emission computed tomography (SPECT) obtained immediately after CEA showed a perfusion defect in the right parietal lobe and absence of cerebral hyperperfusion. A computed tomography (CT) scan showed no new abnormal findings. Aspirin therapy was instituted postoperatively. On the second postoperative day, the patient experienced abrupt worsening of left hemiparesis, and subsequent CT imaging demonstrated a hematoma in the right parietal lobe. Cerebral hyperperfusion was absent on repeat SPECT. CONCLUSION: Perioperative cerebral ischemia can result in intracerebral hemorrhage after CEA even in the absence of cerebral hyperperfusion and/or anticoagulation therapy. Further, cerebral perfusion imaging performed immediately after CEA is a useful modality for the identification of occult cerebral ischemia or hyperperfusion that may lead to intracerebral hemorrhage.

Aged↗
PubMed2004

Photosynthetic electron transport differentially regulates the expression of superoxide dismutase genes in liverwort, Marchantia paleacea var. diptera.

Liverwort, Marchantia paleacea var. diptera, contains Mn-superoxide dismutase (Mn-SOD) in mitochondria, Fe-SOD in chloroplast and CuZn-SOD in cytosol. An Mn-SOD gene (MpMnSOD) was isolated from the liverwort. Using this clone together with the liverwort Fe-SOD and CuZn-SOD genes as probes, the expression of three SOD genes was investigated. Under heterotrophic conditions, the transcript of three SOD genes was accumulated light independently. On the other hand, under photoautotrophic conditions, the transcript levels of Fe-SOD and Mn-SOD increased in the light while that of CuZn-SOD decreased. The reverse occurred in the dark. In contrast to the transcript level, the activity of the three SODs was barely affected by light. The transcription inhibitor, cordycepin, inhibited either the light-promoted accumulation of Fe-SOD and Mn-SOD transcript or the light-induced reduction of the CuZn-SOD transcript. Photosynthetic electron transport inhibitors, DCMU and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, inhibited the photo-response in three SOD genes. These results suggest that the transcript abundance of three SOD genes in liverwort is regulated by photosynthetic electron transport but the mechanism regulating the transcript abundance of the CuZn-SOD gene is different from that of the Fe-SOD and Mn-SOD genes.

Amino Acid Sequence↗
PubMed2004

Pretreatment with the free radical scavenger edaravone prevents cerebral hyperperfusion after carotid endarterectomy.

OBJECTIVE: Cerebral hyperperfusion syndrome after carotid endarterectomy (CEA) is a rare but potentially devastating complication. The purpose of the present study, which was not a randomized controlled trial but a case cohort study with historical control, was to determine whether pretreatment with a novel free radical scavenger, edaravone, could prevent occurrence of cerebral hyperperfusion after CEA. METHODS: Fifty patients with ipsilateral internal carotid artery stenosis (>/=70%) underwent CEA with administration of edaravone before internal carotid artery clamping. Preoperative cerebral blood flow and cerebrovascular reactivity (CVR) to acetazolamide were assessed with single-photon emission computed tomography (SPECT). Cerebral blood flow also was measured immediately after CEA and on the 3rd postoperative day. RESULTS: Cerebral hyperperfusion (cerebral blood flow increase >/=100% compared with preoperative values) was revealed by SPECT performed immediately after CEA in only one patient (2%), who also exhibited reduced preoperative CVR. The incidence of post-CEA hyperperfusion as revealed by SPECT in the control group (51 CEA patients without administration of edaravone) was significantly higher (16%) (P = 0.0310, control versus treatment group). In addition, in a subgroup of patients with reduced preoperative CVR, the incidence of post-CEA hyperperfusion as revealed by SPECT in the edaravone group (7%) was significantly lower than that in the control group (67%) (P = 0.0029). Logistic regression analysis demonstrated that reduced preoperative CVR and absence of pretreatment with edaravone were significant independent predictors of post-CEA hyperperfusion as revealed by SPECT. CONCLUSION: Pretreatment with edaravone can prevent occurrence of cerebral hyperperfusion after CEA.

Aged↗
PubMed2004

[The effects of bakumondo-to (mai-men-dong-tang) on asthmatic and non-asthmatic patients with increased cough sensitivity].

UNLABELLED: Some patients with bronchial asthma (BA) have increased throat sensitivity. In some instances, it is envisaged that this may result in increased coughing or wheezing. Bakumondo-to is a traditional herbal medicine that is well known to reduce coughing in patients with BA and chronic bronchitis. AIM: The present study was conducted to investigate the effect of Bakumondo-to on cough sensitivity in patients with BA and non-asthmatic (non-BA) conditions. The effect on respiratory tract inflammation was also examined. METHODS: We examined 21 BA and 22 non-BA subjects whose cough threshold for capsaicin was less than 3.9 microM. We prepared 1000, 500, 250, 125, 62.5, 31.2, 15.6, 7.80, 3.90, 1.95, 0.98, and 0.49 microM solutions. Cough thresholds to a concentration of inhaled capsaicin solution causing 5 or more coughs was measured before treatment and after 2 months or more of treatment with Bakumondo-to (9 g/day, TJ-29). The number of eosinophils in the peripheral blood, the sputum eosinophil ratio, and the ECP level in the serum were also measured before and after treatment. RESULTS: 1. Bakumondo-to significantly improved the cough threshold value in 76% of patients with BA and in 82% with non-BA conditions. 2. Bakumondo-to was more effective in reducing cough sensitivity to capsaicin in BA than in non-BA conditions. 3. While Bakumondo-to did not significantly reduce the sputum eosinophil count, its effectiveness in suppressing cough was greatest in patients whose sputum eosinophil count was > or = 2%. It remains to be established whether Bakumondo-to inhibits eosinophil activation. Our results suggest that Bakumondo-to is an effective therapeutic preparation for cough hypersensitivity accompanying chronic cough disease, especially in cases of severe allergic inflammation.

Adult↗
PubMed2003

Prostaglandin D2 reinforces Th2 type inflammatory responses of airways to low-dose antigen through bronchial expression of macrophage-derived chemokine.

PGD2, a lipid mediator released from mast cells, is known to participate in allergic reactions. However, the mechanism by which PGD2 contributes to such reactions remains unclear. We established a novel experimental model of asthma that permitted direct assessment of the role of PGD2 in airway inflammation. Antigen-sensitized mice were exposed to aerosolized prostaglandin D2 (PGD2) 1 d before challenge with low-dose aerosolized antigen. Not only the numbers of eosinophils, lymphocytes, and macrophages but also the levels of IL-4 and IL-5 in bronchoalveolar lavage fluid were higher in PGD2-pretreated mice than in control mice. The expression of macrophage-derived chemokine (MDC), a chemoattractant for Th2 cells, was greater in PGD2-pretreated mice than in control. Injection of anti-MDC antibody into PGD2-pretreated mice markedly inhibited inflammatory cell infiltration as well as Th2 cyto-kine production after antigen challenge. These results indicate that PGD2 accelerates Th2 type inflammation by induction of MDC. Our results suggest that this mechanism may play a key role in the development of human asthma and that MDC might be a target molecule for therapeutic intervention.

Animals↗
PubMed2003

Mechanism-based invention of high-speed living radical polymerization using organotellurium compounds and azo-initiators.

Kinetic analysis reveals the existence of two competing pathways in the organotellurium-mediated living radical polymerization (TERP) at elevated temperature. The rate-determining step, namely, the thermal dissociation process, could be bypassed by the addition of conventional radical initiators, and the polymerization proceeded at low temperature by the degenerative transfer-mediated polymerization. The polymerization conditions are applicable to a variety of vinyl monomers, and the desired polymers form in a highly controlled manner.

Journal Article↗
PubMed2003

Up-regulation of cysteinyl leukotriene 1 receptor by IL-13 enables human lung fibroblasts to respond to leukotriene C4 and produce eotaxin.

Cysteinyl leukotrienes (CysLTs) play an important role in eosinophilic airway inflammation. In addition to their direct chemotactic effects on eosinophils, indirect effects have been reported. Eotaxin is a potent eosinophil-specific chemotactic factor produced mainly by fibroblasts. We investigated whether CysLTs augment eosinophilic inflammation via eotaxin production by fibroblasts. Leukotriene (LT)C(4) alone had no effect on eotaxin production by human fetal lung fibroblasts (HFL-1). However, LTC(4) stimulated eotaxin production by IL-13-treated fibroblasts, thereby indirectly inducing eosinophil sequestration. Unstimulated fibroblasts did not respond to LTC(4), but coincubation or preincubation of fibroblasts with IL-13 altered the response to LTC(4). To examine the mechanism(s) involved, the expression of CysLT1R in HFL-1 was investigated by quantitative real-time PCR and flow cytometry. Only low levels of CysLT1R mRNA and no CysLT1R protein were expressed in unstimulated HFL-1. In contrast, stimulation with IL-13 at a concentration of 10 ng/ml for 24 h significantly up-regulated both CysLT1R mRNA and protein expression in HFL-1. The synergistic effect of LTC(4) and IL-13 on eotaxin production was abolished by CysLT1R antagonists pranlukast and montelukast. These findings suggest that IL-13 up-regulates CysLT1R expression, which may contribute to the synergistic effect of LTC(4) and IL-13 on eotaxin production by lung fibroblasts. In the Th2 cytokine-rich milieu, such as that in bronchial asthma, CysLT1R expression on fibroblasts might be up-regulated, thereby allowing CysLTs to act effectively and increase eosinophilic inflammation.

Cell Line↗
PubMed2003

Effects of CD80 and CD86 on cytokine production in patients with wasp-venom allergy who receive venom immunotherapy.

Several studies have provided evidence that activation of antigen-specific T cells requires interactions between CD28 on T cells and its ligands, CD80 and CD86, on antigen-presenting cells (APCs). However, the effects of CD80 and CD86 on cytokine production in patients with Hymenoptera venom allergy who receive venom immunotherapy remain unclear. We examined the effects of CD80 and CD86 on Th1- and Th2-cytokine production before and after venom immunotherapy in patients with wasp-venom allergy. Peripheral blood mononuclear cells (PBMCs) were isolated from patients with wasp-venom allergy before and after three months of venom immunotherapy. CD4+ T cells and monocytes were isolated as APCs from PBMCs and were cocultured with wasp venom in the presence of anti-CD80 or -CD86 blocking antibodies. Interleukin (IL)-4, IL-10, and interferon (IFN)-gamma were measured by enzyme-linked immunosorbent assay. The expression of CD80 and CD86 on CD14+ PBMCs was detected by fluorescence-activated cell-sorter analysis. The expression of CD86, but not that of CD80, on CD14+ PBMCs cocultured with venom increased after three months of venom immunotherapy, but not before venom immunotherapy. Blockade of CD86 reduced IL-10 production after three months of venom immunotherapy. IL-10 production promoted by CD86 costimulation may be involved in the mechanism of venom immunotherapy in patients with venom allergy.

Antigens, CD↗
PubMed2003

Production of TARC and MDC by naive T cells in asthmatic patients.

The helper (Th)2 cell-attracting chemokines thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) are ligands for the chemokine receptor CCR4. A number of cellular sources of TARC and MDC have been identified, including not only macrophages, dendritic cells, and natural killer cells, but also bronchial epithelial cells. Recent studies report that TARC and MDC may serve as pivotal chemokines for the development of Th2-dominated experimental allergen-induced asthma. This study was designed to assess TARC and MDC production by CD4+ T cells, including naive T cells and memory/effector T cells, purified from peripheral blood mononuclear cells in patients with asthma. Asthmatic subjects included in this study had mild asthmatic symptoms, positive skin test responses to house dust mite allergen, and elevated level of Dermatophagoides farinae immunoglobulin E in the sera. CD4+ T cells--CD45RA+ CD4+ T cells--as naive T cells and CD45RO+ CD4+ T cells--as memory/effector T cells--were purified by negative selection from peripheral blood mononuclear cells obtained from asthmatic patients (n = 6) and healthy controls (n = 6). These cells and established Th1/Th2 cell lines were then cultured in the presence of both anti-CD3 and -CD28 antibodies. After 48 hr of incubation, concentrations of TARC, MDC, interleukin (IL)-4, IL-5, and interferon-gamma in the supernatants were measured by enzyme-linked immunoadsorbent assay. Reverse transcriptase-polymerase chain reaction was performed to analyze mRNA expression of TARC and MDC. Our results clearly showed that TARC and MDC were produced by activated CD45RA+ CD4+ T cells rather than by activated CD45RO+ CD4+ T cells, and the levels of these chemokines in the asthmatic patients were higher than those in the healthy controls. Furthermore, these chemokines production by Th2 cell lines were greater than those by Th1 cell lines, but the level were smaller than those by naive T cells. Our studies suggest that TARC and MDC are produced by naive T cells rather than by memory/effector T cells, including Th2 cells, in asthmatic patients, and these chemokines were produced at modest levels in any T-cell populations from healthy controls. Taken together, naive T cells in asthma have a peculiar function to produce TRAC and MDC, which contribute to local migration of Th2 cells into lung and lymphoid tissues, along with a function as precursor for memory/effector T cell. This novel function of naive T cells may be implicated in the development of asthma.

Adult↗
PubMed2003

A phase II study of radiotherapy after hyperbaric oxygenation combined with interferon-beta and nimustine hydrochloride to treat supratentorial malignant gliomas.

Hypoxic cells play a key role in the radioresistance of malignant glioma. Interferon-beta, ACNU as nimustine hydrochloride and radiotherapy (IAR) is a common therapy for malignant glioma in Japan. Since hyperbaric oxygenation (HBO) increases oxygen pressure in glioma tissue, we applied a modified IAR therapy, radiotherapy after HBO combined with interferon-beta and ACNU (HBO/IAR therapy), for supratentorial malignant gliomas. Daily radiation therapy was completed within 15 min after HBO. We assessed HBO/IAR with respect to toxicity, response rates and the time of tumor progression (TTP). We also examined the incidence of responses by some prognostic factors before HBO/IAR, namely, age, Karnofsky performance scale (KPS), histological type, tumor size, tumor site and operation type. Of 39 patients who participated in this study, 35 underwent a complete schedule of HBO/IAR therapy in which toxicity was permissible. Thirty patients (76.9%) either maintained or increased KPS during HBO/IAR with a mean duration of 68 +/- 14 days. The response rates (CR + PR%) for glioblastoma, anaplastic astrocytoma and overall were 50%, 30% and 43%, respectively. The incidence of therapeutic responses among all prognostic factors before HBO/IAR did not significantly differ. Median TTP for patients with glioblastoma, patients with anaplastic astrocytoma, and overall were 38, 56 and 43 weeks, respectively. The present study suggested that HBO/IAR therapy could be applied to especially patients with poor prognostic factors, because of its short treatment period, its permissible toxicity and identical response to patients with good prognostic factors.

Adult↗