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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

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

Electron microscopic studies on the occurrence of activated neutrophils in peripheral blood of children with acute leukemias.

Peripheral blood (PB) cells are examined to assess cellular maturity and the degree of bone marrow abnormality in children with acute leukemias. During the ultrastructural assessments of PB cells in these children, we noted a frequent occurrence of activated neutrophils. This phenomenon had not been reported previously. We here report for the first time the identification of activated neutrophils in PB of children with acute leukemias. To examine the impact of activated neutrophils, we compared two groups of children including 18 with acute lymphoblastic leukemia (ALL) and 7 with acute myelogenous leukemia (AML) by an ultrastructural leukocyte count method. Many cases (50%) showed more than 30% activated neutrophils per total neutrophil count in PB. Activated neutrophils were elongated or amoeboid-shaped cells ranging from 13-18 microns in greater diameter with a decreased number of granules in the cytoplasm. A significantly higher rate of activated neutrophils was observed in ALL as compared with AML (median: 42.97% vs. 10.64%). Non-leukemic hospitalized (n =3) and healthy (n = 3) control cases showed a median rate of 3.32% activated neutrophils in PB. These findings reveal that a significantly high rate of activated neutrophils occurs in PB of children with ALL which may be exploited in the diagnostic assessment of children with acute leukemias.

Child↗
PubMed2004

Clinically mild encephalitis/encephalopathy with a reversible splenial lesion.

OBJECTIVE: To clarify whether patients with clinical diagnoses of encephalitis/encephalopathy with a reversible lesion in the splenium of the corpus callosum (SCC) share common clinical features. METHODS: Possible encephalitis/encephalopathy patients with a reversible isolated SCC lesion on MRI were collected retrospectively. Their clinical, laboratory, and radiologic data were reviewed. RESULTS: Fifteen encephalitis/encephalopathy patients with a reversible isolated SCC lesion were identified among 22 patients referred for this study. All 15 patients had relatively mild clinical courses. Twelve of the 15 patients had disorders of consciousness. Eight patients had seizures, and three of them received antiepileptic drugs. All 15 patients clinically recovered completely within 1 month (8 patients within a week) after the onset of neurologic symptoms. The SCC lesion was ovoid in six patients; it extended irregularly from the center to the lateral portion of SCC in the other eight patients. Homogeneously reduced diffusion was seen in all seven patients who underwent diffusion-weighted imaging. There was no enhancement in the five patients so examined. The SCC lesion had completely disappeared in all patients at follow-up MRI exams between 3 days and 2 months after the initial MRI (within 1 week in eight patients). CONCLUSION: The clinical features among the affected patients were nearly identical, consisting of relatively mild CNS manifestations and complete recovery within 1 month.

Adolescent↗
PubMed2004

Dissecting aneurysm of the posterior communicating artery.

A 36-year-old male presented with an extremely rare dissecting aneurysm of the posterior communicating artery manifesting as severe occipital headache. Magnetic resonance (MR) imaging revealed a partially thrombosed aneurysm of the right posterior communicating artery and angiography showed the pearl and string sign. Three months later, repeat angiography showed that the aneurysm was completely thrombosed and the posterior communicating artery was occluded. Magnetic resonance (MR) imaging showed an intimal flap. These neuroradiological findings demonstrated that the aneurysm was a dissecting aneurysm of the right posterior communicating artery. He was discharged with no neurological deficit.

Adult↗
PubMed2004

Postischemic administration of Sendai virus vector carrying neurotrophic factor genes prevents delayed neuronal death in gerbils.

Sendai virus (SeV) vector-mediated gene delivery of glial cell line-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) prevented the delayed neuronal death induced by transient global ischemia in gerbils, even when the vector was administered several hours after ischemia. Intraventricular administration of SeV vector directed high-level expression of the vector-encoded neurotrophic factor genes, which are potent candidates for the treatment of neurodegenerative diseases. After occlusion of the bilateral carotid arteries of gerbils, SeV vector carrying GDNF (SeV/GDNF), NGF (SeV/NGF), brain-derived neurotrophic factor (SeV/BDNF), insulin-like growth factor-1 (SeV/IGF-1) or vascular endothelial growth factor (SeV/VEGF) was injected into the lateral ventricle. Administration of SeV/GDNF, SeV/NGF or SeV/BDNF 30 min after the ischemic insult effectively prevented the delayed neuronal death of the hippocampal CA1 pyramidal neurons. Furthermore, the administration of SeV/GDNF or SeV/NGF as late as 4 or 6 h after the ischemic insult also prevented the death of these neurons. These results indicate that SeV vector-mediated gene transfer of neurotrophic factors has high therapeutic potency for preventing the delayed neuronal death induced by transient global ischemia, and provides an approach for gene therapy of stroke.

Animals↗
PubMed2004

Roles of major oligosaccharides on Cry j 1 in human immunoglobulin E and T cell responses.

BACKGROUND: We have demonstrated that carbohydrates in Cry j 1, the major allergen of Cryptomeria japonica pollen, play a major role in promoting Cry j 1-specific Th2 response. However, little is known as to whether the carbohydrates directly participate in allergic responses. OBJECTIVE: We sought to determine whether Cry j 1-related oligosaccharides function as IgE and/or T cell epitopes. In addition, the regulatory effect of Cry j 1-related oligosaccharide on Cry j 1-specific T cell responses was investigated. METHODS: Two monovalent oligosaccharides largely found on Cry j 1, Manalpha1-6(Manalpha1-3)(Xylbeta1-2)Manbeta1-4GlcNAcbeta1-4(Fucalpha1-3)GlcNAc (M3FX), and GlcNAcbeta1-2Manalpha1-6(GlcNAcbeta1-2Manalpha1-3)(Xylbeta1-2)Manbeta1-4GlcNAcbeta1-4(Fucalpha1-3)GlcNAc (GN2M3FX) were prepared. Manalpha1-2Manalpha1-6(Manalpha1-2Manalpha1-3)Manalpha1-6(Manalpha1-2Manalpha1-2Manalpha1-3)Manbeta1-4GlcNAcbeta1-4GlcNAc (M9A) was used as control. Competitive inhibition ELISA for Cry j 1-specific IgE was performed using these oligosaccharides as inhibitors. In addition, T cell lines specific for Cry j 1 or purified protein derivative of Mycobacterium tubecurosis (PPD) were established, and cellular responses against these oligosaccharides were investigated in the presence or absence of the respective antigens. RESULTS: Overall, neither M3FX nor GN2M3FX displayed inhibitory effect on the binding between IgE and Cry j 1. In addition, M3FX did not by itself stimulate Cry j 1 or PPD-specific T cells. However, M3FX significantly inhibited Cry j 1-induced proliferation and IL-4 production in Cry j 1-specific T cells. Such an inhibitory effect was not seen in PPD-specific T cell responses. CONCLUSION: These results suggest that Cry j 1-related oligosaccharides are not major epitopes for IgE or T cells. However, these oligosaccharides have a novel potential to inhibit Cry j 1-specific T cell responses selectively.

Adolescent↗
PubMed2003

Observation of arterial and venous thrombus formation by scanning and transmission electron microscopy.

BACKGROUND: In order to examine the process of thrombosis formation in artery and vein, the reactions of the arterial and venous endothelial surfaces were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in the photothrombosis model. MATERIALS AND METHODS: Thirty-nine rats were divided into the following 4 groups: 1) Sham group (n = 5) without illumination, 2) group A (n = 10) irradiated for 1 min, 3) group B (n = 10) irradiated for 5 min, 4) group C (n = 14) irradiated for 10 min at the level of the left common carotid artery and internal jugular vein. RESULTS: SEM provided no evidence of damage or adhesion of blood platelets to the endothelium of either the artery or vein in shams or group A animals. In group B, evidence of damage to endothelial cell membrane (e.g., plasmalemmal pits, crater-like structures associated with tears between endothelial cells, and decreased number of microvilli) was obtained in the arterial wall but not in the vein. In group C, there was extensive or widespread adhesion of blood platelets and other cells, tears between arterial endothelial cells, and a decrease in the number of microvilli in the artery but not in the vein (p < 0.05). CONCLUSIONS: Cell membrane injuries, tears between the endothelial cells, and endothelial detachment occur before adhesion of blood platelets and thrombus formation in the blood vessel occlusion model by photochemical reaction. These changes occur significantly earlier in the artery than in the vein.

Animals↗
PubMed2003

Crystallization of a large single crystal of cubic insulin for neutron protein crystallography.

The growth of a large single crystal of cubic porcine insulin for characterization of hydrogen and hydration in cubic insulin crystals by neutron diffraction analysis is reported. Growth in D2O was investigated based on the phase diagram for cubic insulin to determine appropriate growth conditions, and a large single crystal was then successfully grown by a dialysis method to a size of 4.0 x 4.0 x 1.3 mm3. Neutron diffraction analysis of the cubic insulin crystals was carried out using a single-crystal diffractometer at the JRR-3M reactor of the Japan Atomic Energy Research Institute. In preliminary analysis, Npi appears to be protonated and Ntau deprotonated in His5 in the B-chain, whereas both Npi and Ntau are protonated in His10.

Crystallization↗
PubMed2003

Novel bioluminescent assay of alkaline phosphatase using adenosine-3'-phosphate-5'-phosphosulfate as substrate and the luciferin-luciferase reaction and its application.

This paper describes a novel bioluminescent assay of alkaline phosphatase (ALP) utilizing ATP-sulfurylase and the luciferin-luciferase reaction. The principle governing the assay is as follows. Adenosine-3'-phosphate-5'-phosphosulfate, which serves as the substrate for ALP, is hydrolyzed enzymatically to produce adenosine-5'-phosphosulfate (APS). APS is converted into ATP by ATP-sulfurylase in the presence of pyrophosphate. The ATP produced is detected by the luciferin-luciferase reaction. The measurable range was 1 zmol to 100 fmol/assay and the detection limit at blank+3 SD was 10 zmol/assay. The coefficient of variation (CV, n=5) was examined at each point of the standard curve; the mean CV percentage was 4.47% (n=6). This assay system was applied to enzyme immunoassay of human chorionic gonadotropin and allele-specific PCR enzyme-linked immunosorbent assay of verotoxin gene using ALP as the label enzyme; 10(-2) mIU/mL hCG in urine and 5 pg of Escherichia coli O157 DNA could be assayed directly and with high sensitivity by the proposed method.

Adenosine Phosphosulfate↗
PubMed2003

Risk factors for the occurrence of chronic subdural haematomas after neurosurgical procedures.

Chronic subdural haematoma (CSDH) is a rare clinical complication of neurosurgical procedures. CSDH occurs sporadically after aneurysm clipping surgery and revascularisation surgery but the risk factors are not known. The present study reviewed 6613 consecutive neurosurgical procedures performed from January 1987 to July 2001, and identified 621 cases of CSDH. Fifty of these 621 cases had a past history of neurological disorders treated by neurosurgery. This study evaluated these 50 cases in order to elucidate the clinical and radiological characteristics of CSDH after neurosurgery and to investigate the etiology for identifying in the risk factors of CSDH as a postoperative complication. The incidence of CSDH after neurosurgery was 0.8% (50/6613). Twenty-seven of the 50 patients with a past history of neurosurgery had undergone aneurysm clipping surgery. The incidence after clipping surgery was 2.4%. Twelve of these 27 cases also underwent ventriculoperitoneal shunting. Three patients had postoperative CSDH after arachnoid cyst opening and/or shunting. The incidence was highest at 7.5%. Three patients had postoperative CSDH after brain tumour surgery. The incidence was low at 0.4%. However, the ventricular cerebrospinal fluid (CSF) space was opened during tumour removal in 2 of these 3 patients. Communication of the subarachnoid space to the subdural space is considered to be one of the causative factors and excessive CSF shunting facilitates formation of CSDH after neurological surgery. Repair of arachnoid tearing during neurosurgery and avoidance of excessive CSF shunting may reduce the risk of CSDH after neurosurgery.

Adult↗
PubMed2003

Dural arteriovenous fistula of the transverse sinus with concomitant ipsilateral meningioma.

A 69-year-old female complained of headache and tinnitus. Computed tomography, magnetic resonance imaging, and angiography showed a tumour in the right transverse sinus extending to the transverse-sigmoid sinus junction, a dural arteriovenous fistula (AVF), and right transverse-sigmoid sinus thrombosis with the downstream from the right sigmoid sinus involved by the tumour. Right external carotid angiography showed the tumour to be supplied by many branches of the right occipital artery, the posterior branches of the middle meningeal artery, and the posterior auricular artery, and the dural AVF fed by the occipital artery and the meningeal branches of the right vertebral artery. She underwent surgery via a combined right supra- and infratentorial approach. The tumour had invaded and blocked the right transverse sinus, which was resected. After surgery the patient was free of headache and tinnitus was diminished. Histological examination found that the tumour was a fibrous meningioma and that the orifice of the vein at the transverse sinus was blocked by the tumour. Serial follow-up cerebral angiography 2 months after surgery showed no change in the AVF, but 9 months after surgery confirmed disappearance of the AVF. This AVF was caused by occlusion of the right transverse sinus by the meningioma and was an acquired lesion.

Aged↗
PubMed2003

Germinoma in the fourth ventricle.

A 33-year-old male presented with trigeminal, abducens, and facial nerve pareses associated with cerebellar signs. Magnetic resonance imaging showed a homogeneously enhanced mass occupying the lower half of the fourth ventricle and attached to the floor of the fourth ventricle. The mass was subtotally removed. The histological diagnosis was pure germinoma. Neuro-imaging cannot distinguish germinoma in the fourth ventricle from ependymoma. Germinoma in the fourth ventricle is extremely rare and requires histological differentiation from ependymoma to determine the indications for adjuvant irradiation and/or chemotherapy.

Adult↗
PubMed2003

Orbital cystic neurinoma.

A 64-year-old woman presented with a 6-month history of exophthalmus of her right eye. She had no neurological deficit except for the exophthalmus and numbness in the right side of her forehead (frontal nerve territory). Neuro-imaging demonstrated a cystic mass in the right orbit. The tumour was totally removed by microsurgical transcranial surgery. The histological diagnosis was neurinoma. The origin of the tumour was considered to be the frontal nerve. Only two other cases of orbital cystic neurinoma have been reported. This rare clinical entity should be included in the differential diagnosis of a cystic mass in the orbit.

Cysts↗
PubMed2003

Growth inhibition through activation of peroxisome proliferator-activated receptor gamma in human oesophageal squamous cell carcinoma.

Peroxisome proliferator-activated receptor gamma (PPARgamma) heterodimerises with retinoid X receptor alpha (RXRalpha) and is thought to be a novel therapeutic target for human malignancies. We evaluated the ability of troglitazone (TRO) alone or in combination with 9-cis retinoic acid (9CRA), ligands of PPARgamma and RXRalpha, respectively, to inhibit the growth of oesophageal squamous cell carcinoma (OSCC). All 10 tested OSCC cell lines of a KYSE series expressed PPARgamma and RXRalpha at both the mRNA and protein levels. In four tested cell lines, TRO inhibited growth, and a synergistic effect was observed with simultaneous 9CRA application. In KYSE 270 cells, a luciferase reporter assay showed that the simultaneous application of TRO and 9CRA to the cells increased the relative luciferase activity approximately 20-fold compared with the controls without TRO or 9CRA application. In this cell line, flow cytometry demonstrated that combined treatment with TRO and 9CRA greatly increased the sub-G1 phase, and Hoechst 33342/propidium iodide (PI) staining showed that apoptotic cell death was mainly induced through ligand treatment. In addition, implanted tumours in nude mice showed significant inhibition of tumour growth when treated with TRO. These results suggest that the PPARgamma/RXRalpha heterodimer may be a new therapeutic target for OSCC.

Alitretinoin↗
PubMed2003

Successful treatment of natural killer (NK) cell leukemia following a long-standing chronic active Epstein-Barr virus (CAEBV) infection with allogeneic bone marrow transplantation.

The optimal treatment for natural killer (NK) cell leukemia after chronic active Epstein-Barr virus (CAEBV) infection has not been determined. A 15-year-old boy presented with NK cell leukemia following CAEBV infection for 5 years. The peripheral blood and BM had an increased number of CD3(-)CD56(+) large granular lymphocytes and a monoclonal integration of the EBV genome was detected. Chemotherapy was not sufficiently effective to control the disease. Allogeneic BMT from an HLA-identical sister was performed using a conditioning regimen consisting of total body irradiation, cyclophosphamide and thiotepa. The patient is disease-free with a perfect performance status 24 months after BMT. This is the first report to show that allogeneic BMT is potentially able to cure NK cell leukemia after CAEBV infection.

Adolescent↗
PubMed2003

Influence of transplanted dose of CD56+ cells on development of graft-versus-host disease in patients receiving G-CSF-mobilized peripheral blood progenitor cells from HLA-identical sibling donors.

We investigated effects of variations in the cellular composition of G-CSF-mobilized peripheral blood progenitor cell (G-PBPC) allografts on clinical outcomes of allogeneic PBPC transplantation. We retrospectively analyzed transplanted doses of various immunocompetent cells from 27 HLA-identical sibling donors in relation to engraftment, incidence of graft-versus-host disease (GVHD), and survival. Significant variability was documented in both absolute numbers and relative proportions of CD34+, CD2+, CD3+, CD4(high)+, CD4+25+, CD8(high)+, CD19+, CD56+, and CD56+16+ cells contained in these allografts. Stepwise Cox regression analysis revealed that the CD56+ cell dose was significantly inversely correlated with the incidence of GVHD. Thus, there was a significantly higher incidence of grade II acute GVHD in patients receiving a lower CD56+16+ cell dose (hazard ratio (HR) 0.0090; 95% confidence interval (CI), <0.00001-3.38; P=0.031), a higher incidence of chronic GVHD in those receiving allografts with a lower CD56+16+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.0007; P=0.0035), and a higher incidence of extensive chronic GVHD in those receiving allografts with a lower CD56+ to CD34+ ratio (HR <0.00001; 95% CI <0.00001-0.053; P=0.0083). These results suggest that CD56+ cells in G-PBPC allografts from HLA-identical sibling donors may play an important role in preventing the development of GVHD.

Adult↗
PubMed2003

Attenuation of ganglioside GM1 accumulation in the brain of GM1 gangliosidosis mice by neonatal intravenous gene transfer.

A single intravenous injection with 4 x 10(7) PFU of recombinant adenovirus encoding mouse beta-galactosidase cDNA to newborn mice provided widespread increases of beta-galactosidase activity, and attenuated the development of the disease including the brain at least for 60 days. The beta-galactosidase activity showed 2-4 times as high a normal activity in the liver and lung, and 50 times in the heart. In the brain, while the activity was only 10-20% of normal, the efficacy of the treatment was distinct. At the 30th day after the injection, significant attenuation of ganglioside GM1 accumulation in the cerebrum was shown in three out of seven mice. At the 60th day after the injection, the amount of ganglioside GM1 was above the normal range in all treated mice, which was speculated to be the result of reaccumulation. However, the values were still definitely lower in most of the treated mice than those in untreated mice. In the histopathological study, X-gal-positive cells, which showed the expression of exogenous beta-galactosidase gene, were observed in the brain. It is noteworthy that neonatal administration via blood vessels provided access to the central nervous system because of the incompletely formed blood-brain barrier.

Adenoviridae↗
PubMed2003

Characterization of a mosquitocidal Bacillus thuringiensis serovar sotto strain isolated from Okinawa, Japan.

AIMS: To characterize the mosquitocidal activity of parasporal inclusions of the Bacillus thuringiensis serovar sotto strain 96-OK-85-24, for comparison with two well-characterized mosquitocidal strains. METHODS AND RESULTS: The strain 96-OK-85-24 significantly differed from the existing mosquitocidal B. thuringiensis strains in: (1) lacking the larvicidal activity against Culex pipiens molestus and haemolytic activity, and (2) SDS-PAGE profiles, immunological properties and N-terminal amino acid sequences of parasporal inclusion proteins. CONCLUSIONS: It is clear from the results that the strain 96-OK-85-24 synthesizes a novel mosquitocidal Cry protein with a unique toxicity spectrum. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of the occurrence of a mosquitocidal B. thuringiensis strain with an unusual toxicity spectrum, lacking the activity against the culicine mosquito.

Amino Acid Sequence↗