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Biomedical subjects

E Ikeda

Publications and source records attributed to E Ikeda.

At least 37 records · Page 2Linked to original sources
PubMed2000

Choledochal stenosis and lithiasis caused by penetration and migration of surgical metal clips.

A 71-year-old woman, who had undergone laparoscopic cholecystectomy 1 year previously at our hospital, presented with abdominal pain, high fever, and jaundice. She was diagnosed with choledochal stenosis caused by migration of the clips that were used at the previous operation. At reoperation, the common bile duct was successfully dissected, including the stenotic site, where a metal clip was found to be penetrating the duct wall. The stenotic site was sufficiently resected, when a black-brown gallstone was found proximally to the stenosis. Interestingly, the stone was found to contain two metal clips, which were considered to have migrated into the bile duct and to have acted as a nidus for stone formation. The common bile duct was reconstructed by direct end-to-end anastomosis. Surgeons must exercise caution in the use of metal clips, keeping in mind the potential risk of clip migration.

Aged↗
PubMed2000

Lateral ventricular meningioma encapsulated by the dura-like membrane.

The first case of a ventricular meningioma that was encapsulated by the dura-like membrane is reported. Magnetic resonance imaging (MRI) showed a heterogeneous mass with a low intensity rim in the trigone of the right lateral ventricle of a 63-year-old male. Histological examination revealed that the tumor was a transitional meningioma encapsulated by a thick dura-like membrane. Moreover, abundant clusters of the dura-like connective tissue existed in the tumor, indicating that both the dura-like capsule and the dura-like clusters in the tumor were created by the tumor cells.

Dura Mater↗
PubMed2000

Expression of vascular endothelial growth factor and its receptors correlates closely with formation of the plexiform lesion in human pulmonary hypertension.

The pulmonary vasculature exhibits various morphological changes in patients with pulmonary hypertension (PH). Among them, the plexiform lesion is one of the most characteristic vascular lesions, although nothing is known about the molecular mechanisms of its formation. In the present study, the expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific angiogenic mitogen, and its receptors, fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing receptor (KDR), in the lungs of five cases with PH, were examined. By in situ hybridization, VEGF expression was found in modified smooth muscle cells inside the plexiform lesions as well as in medial smooth muscle cells of the arteries adjacent to the lesions. The expression of Flt-1 mRNA was observed in endothelial cells of the arteries adjacent to the plexiform lesions, while KDR mRNA was expressed in the endothelial cells inside the plexiform lesions. VEGF was immunolocalized to the endothelial cells expressing its receptors as well as the modified smooth muscle cells producing VEGF. These results demonstrate that VEGF and its receptors are upregulated with a close correlation to the plexiform lesions, and suggest that VEGF expressed by smooth muscle cells may activate the endothelial cells to form the plexiform lesions.

Adolescent↗
PubMed2000

Experimental lung transplantation using non-penetrating vascular clips for anastomosis of the pulmonary artery.

BACKGROUND: Reliable and rapid anastomosis is critical in lung transplantation. The purpose of this study is to show the appropriateness of sutureless anastomosis of the pulmonary artery using a nonpenetrating vascular clipping device. METHODS: The left lung was excised and the cranial lobe was transplanted autologously in 9 dogs. The anastomosis of the left main pulmonary artery (PA) (1 cm) was performed using a vascular clipping system. RESULTS: PA anastomosis was performed in 7 dogs in 8 to 13 minutes. The endovascular surface of the anastomotic site was smooth, and passage of silicone rubber through the anastomosis was good 14 or 28 days after surgery. Microscopic examination of the anastomotic sites showed excellent healing without evidence of intimal hyperplasia. CONCLUSIONS: The vascular clipping system facilitates anastomosis of the PA in lung transplant surgery.

Anastomosis, Surgical↗
PubMed2000

Reduction of vesicular acetylcholine transporter in beta-amyloid protein-infused rats with memory impairment.

The aim of this study was to investigate spatial memory and quantitative acetylcholine transporter autoradiography using a high-sensitivity imaging plate system in rats treated with beta-amyloid protein, a model of Alzheimer's disease. An eight-arm radial maze was used to evaluate spatial memory. The performance of the eight-arm radial maze task was impaired in beta-amyloid protein-treated rats. In the parietal cortex, [3H]-vesamicol binding to the vesicular acetylcholine transporter was significantly lower in beta-amyloid protein-treated rats than in vehicle-treated rats, and was significantly correlated with the mean number of correct selections in the maze task of the first 5 days in the post-operative state. These results indicate that the reduction in [3H]-vesamicol binding to vesicular acetylcholine transporter is related to memory impairment induced by beta-amyloid protein. Beta-amyloid protein-infused rats with spatial memory impairment may be useful for the development of new radiolabelled vesamicol analogues for the objective evaluation of Alzheimer's disease.

Alzheimer Disease↗
PubMed2000

Importance of interleukin-8 in the development of reexpansion lung injury in rabbits.

Reexpansion of a collapsed lung induces increased microvascular permeability leading to reexpansion pulmonary edema (REPE). This study was designed to prove the hypothesis that local overproduction of interleukin-8 (IL-8) induces inflammatory cell accumulation which leads to the induction of REPE. Initially, we examined the detailed characteristics of a rabbit model of REPE in association with IL-8 production and its mRNA expression. The lung tissue to plasma ratio of radiolabeled albumin (T/P ratio), the lung wet to dry ratio, and bronchoalveolar lavage (BAL) neutrophil counts were significantly increased in the reexpanded lung. IL-8 concentrations and mRNA expression were significantly increased in the reexpanded lung homogenate. Immunohistochemically, alveolar macrophages (AMs) and epithelial cells in the reexpanded lung and AMs in the collapsed lung were positive for IL-8. Second, we examined the effect of pretreatment with a specific monoclonal anti-IL-8 antibody (Ab) or control IgG on the development of REPE. The T/P ratio and BAL neutrophil counts were conspicuously decreased by pretreatment with anti-IL-8 Ab, but not with control IgG. On a histopathological study, lung injury and leukocyte infiltration were attenuated by the pretreatment with anti-IL-8 Ab. In conclusion, IL-8 production is enhanced in the reexpanded lung, and contributes to the development of REPE. The pretreatment with anti-IL-8 antibody may be useful as a novel protective therapy for this disease.

Animals↗
PubMed2000

Primary osteosarcoma of the sphenoid bone with extensive periosteal extension--case report.

A 28-year-old male presented with a primary osteosarcoma of the sphenoid bone with extensive periosteal extension manifesting as severe headache and right exophthalmos. Computed tomography (CT) and magnetic resonance imaging revealed an anterior middle cranial fossa tumor extending into both the orbit and the extracranial space. However, roentgenography and CT with bone windows showed no marked osteolytic changes of the sphenoid bone. Total removal of the tumor was performed via the orbitozygomatic approach. Surgery revealed that the tumor had extended periosteally without macroscopic bone destruction, but no obvious abnormalities of the skull. The histological diagnosis was osteosarcoma. The patient was treated with chemotherapy and radiation therapy, but died of tumor recurrence 10 months after the surgery.

Adult↗
PubMed2000

Angiotensin II-stimulated vascular endothelial growth factor expression in bovine retinal pericytes.

PURPOSE: Angiotensin II (AII) has been shown to play a role in many vascular diseases. In the study described, the effect of AII on vascular endothelial growth factor (VEGF) expression and related intracellular signaling mechanism was investigated in bovine retinal microcapillary pericytes. METHODS: Cultured bovine retinal microvascular endothelial cells and pericytes were prepared. VEGF expression was determined by Northern blot analysis and immunoprecipitation assay. Cell proliferation was assessed by DNA content growth assay. Reporter gene studies were performed to identify the AII responsible transcription-activating region of VEGF gene. RESULTS: Angiotensin II induced a significant increase in VEGF mRNA in a time- and dose-dependent manner. Angiotensin II type I receptor antagonist inhibited this effect. Angiotensin II activates the transcription of VEGF gene without changing the mRNA half-life, and the AII responsible region was found in the 5'-flanking region of the VEGF gene. Angiotensin II also increased the expression of c-fos and c-jun mRNA, and antisense oligonucleotides against c-Fos blocked the AII-induced VEGF mRNA expression. The conditioned media of AII-stimulated pericyte cultures had a growth-promoting effect on endothelial cells, and this effect was inhibited almost completely by VEGF neutralizing antibody. CONCLUSIONS: These findings suggest that AII might induce angiogenic activity through a paracrine function of VEGF in retinal microvascular cells.

Angiotensin II↗
PubMed2000

Coexpression of VEGF receptors VEGF-R2 and neuropilin-1 in proliferative diabetic retinopathy.

PURPOSE: To elucidate vascular endothelial growth factor (VEGF)-mediated pathogenesis of fibrovascular proliferation in diabetic retinopathy. METHODS: Fibrovascular tissues were obtained at vitrectomy from 22 cases with proliferative diabetic retinopathy. The half-divided tissues were processed for reverse transcription-polymerase chain reaction (RT-PCR) analysis to examine the expression of VEGF isoforms and their receptors. Paraffin sections of the other half were used for immunohistochemistry for CD34, glial fibrillary acidic protein and VEGF, and in situ hybridization for VEGF. RESULTS: RT-PCR analysis demonstrated the expression of VEGF receptors VEGF-R1, VEGF-R2, and neuropilin-1 in 12, 14, and 14 of 22 cases, respectively. Notably, VEGF-R2 and neuropilin-1 were simultaneously expressed in the identical 14 tissues. The isoform VEGF121 was constitutively expressed in all the tissues examined, whereas the expression of VEGF165 was confined to the 7 tissues that also expressed VEGF-R2 and neuropilin-1. The vascular density of fibrovascular tissues evaluated by immunohistochemistry for CD34 was significantly higher in the cases with the expression of VEGF-R2 and neuropilin-1 than in those without their expression (P < 0.01), whereas VEGF-R1 expression had no such relationship with the vascular density. The fibrovascular tissues that expressed VEGF165 together with VEGF-R2 and neuropilin-1 were found in significantly younger patients (P < 0.01). In situ hybridization and immunohistochemical studies demonstrated that glial cells in the fibrovascular tissues express and produce VEGF. CONCLUSIONS: Coexpression of VEGF-R2 and neuropilin-1 is suggested to facilitate fibrovascular proliferation in diabetic retinopathy.

Adult↗
PubMed2000

Behçet's disease in Japan and in Great Britain: a comparative study.

Behçet's disease (BD) is an important cause of visual morbidity throughout the world, but shows striking differences in racial predilection. Despite important advances in the therapeutic management of acute intraocular inflammation, the long-term impact of these new strategies on visual outcome of BD and their efficacy in different ethnic groups is unknown. A comparative study of patient characteristics, clinical ocular features and inflammatory score, and current therapy was undertaken on all patients fulfilling the International Study Group criteria for Behçet's disease and the Behçet's Disease Research Committee of Japan, who attended the Uveitis Clinics of Moorfields Eye Hospital (n=19) and Kurume University School of Medicine (KUS) (n=35) during a continuous consecutive four-week period. Japanese patients were significantly older (43.2+/-11.8 years) than the patients seen in London (35.4+/-8. 9 years). There was a predominance of male patients in both groups. All patients seen in KUS were Japanese, while the patients in London included 12 Caucasians, five Middle Eastern, one African, and one Asian. No significant differences were seen between the two populations in the duration of systemic disease or systems affected by the disease, such as mouth ulcers, genital ulcers, skin lesions including erythema nodosum, or arthritis. The duration of ocular disease was similar in both centres: around seven years. There was, however, a significant difference in the number of eyes with active anterior uveitis (59.7% KUS vs 18.4% London (chi-square: 5.4; p=0.006)) and/or posterior uveitis (31.3% KUS vs 18.4% London (chi-square: 5.42; p<0.02)). No significant differences were found in the number of eyes with optic disc swelling or optic atrophy and in each centre the number of eyes with vision greater than 6/9 or worse than 6/60 were the same. The treatment schedules were very different between the two centres. More patients were treated with topical steroids in Japan (68.7% KUS vs 10.5% London (chi-square: 30.5; p=0.001), but a similar number used concomitant intraocular pressure-lowering agents. More patients received systemic steroids in London (84.2% London vs 17% KUS (chi-square: 20.25; p<0.001)). Three patients received systemic steroids alone, five had prednisolone and cyclosporin, four had prednisolone and azathioprine, and four had triple therapy with prednisolone, cyclosporin, and azathioprine. Only one patient used colchicine. Cyclosporin use was similar in London and KUS (47.4% and 42.8%, respectively). In Japan, three patients used prednisolone alone and three tacrolimus (FK506). In addition, two patients, who were on steroids alone, took colchicine as well. More patients in Japan had undergone surgery for cataract and glaucoma (chi-square: 4.0; p=0.045). In KUS, seven of 67 eyes had cataract surgery. A further three eyes had visually significant cataract and two eyes had undergone glaucoma surgery. In contrast, no patients in London had undergone any surgery up to and including this period.

Administration, Topical↗
PubMed1999

Two distinct mechanisms operate in the reactivation of heat-denatured proteins by the mitochondrial Hsp70/Mdj1p/Yge1p chaperone system.

The yeast mitochondrial Hsp70, Ssc1p, functions as a molecular chaperone with its partner proteins, Mdj1p (DnaJ homologue) and Yge1p (GrpE homologue). We have purified a mature form of Ssc1p from yeast mitochondria and those of Mdj1p and Yge1p from Escherichia coli overexpresser cells. With these purified components of the mitochondrial Hsp70 chaperone system, we have succeeded in reconstituting their chaperone functions in the protection of firefly luciferase against thermal damage in vitro. Heat-denatured luciferase is prevented from irreversible aggregation and is maintained in a refolding-competent state by Ssc1p and/or Mdj1p at 42 degreesC. Luciferase denatured at 42 degreesC is actively reactivated by Ssc1p, Mdj1p and/or Yge1p after lowering the temperature to 25 degreesC. The reactivation process of heat-denatured luciferase shows two-phase kinetics. The slow refolding process requires either Ssc1p or Mdj1p at 42 degreesC but the presence of Ssc1p, Mdj1p and Yge1p, and ATP hydrolysis, is essential at 25 degreesC. The slow refolding of luciferase involves multiple rounds of formation and dissociation of the complex between luciferase and Mdj1p/Ssc1p. On the other hand, the fast refolding process is most enhanced when luciferase is incubated with Ssc1p alone at 42 degreesC, and it requires neither the assistance of Mdj1p and Yge1p nor ATP hydrolysis. We have observed a similar two-pathway reactivation of heat-denatured luciferase by the bacterial Hsp70 and the yeast cytosolic Hsp70 systems.

Adenosine Triphosphate↗
PubMed1999

Expression and tissue localization of membrane-type 1, 2, and 3 matrix metalloproteinases in human astrocytic tumors.

Three different membrane-type matrix metalloproteinases (MT1-, MT2-, and MT3-MMPs) are known to activate in vitro the zymogen of MMP-2 (pro-MMP-2, progelatinase A), which is one of the key MMPs in invasion and metastasis of various cancers. In the present study, we have examined production and activation of pro-MMP-2, expression of MT1-, MT2-, and MT3-MMPs and their correlation with pro-MMP-2 activation, and localization of MMP-2, MT1-MMP, and MT2-MMP in human astrocytic tumors. The sandwich enzyme immunoassay demonstrates that the production levels of pro-MMP-2 in the anaplastic astrocytomas and glioblastomas are significantly higher than that in the low-grade astrocytomas (P<0.05 and P<0.01, respectively), metastatic brain tumors (P<0.05), or normal brains (P<0.01). Gelatin zymography indicates that the pro-MMP-2 activation ratio is significantly higher in the glioblastomas than in other astrocytic tumors (P<0.01), metastatic brain tumors (P<0.01), and normal brains (P<0.01). The quantitative reverse transcription polymerase chain reaction analyses demonstrate that MT1-MMP and MT2-MMP are expressed predominantly in glioblastoma tissues (17/17 and 12/17 cases, respectively), and their expression levels increase significantly as tumor grade increases. MT3-MMP is detectable in both astrocytic tumor and normal brain tissues, but the mean expression level is approximately 50-fold lower compared with that of MT1-MMP and MT2-MMP in the glioblastomas. The activation ratio of pro-MMP-2 correlates directly with the expression levels of MT1-MMP and MT2-MMP but not MT3-MMP. In situ hybridization indicates that neoplastic astrocytes express MT1-MMP and MT2-MMP in the glioblastoma tissues (5/5 cases and 5/5 cases, respectively). Immunohistochemically, MT1-MMP and MT2-MMP are localized to the neoplastic astrocytes in glioblastoma samples (17/17 cases and 12/17 cases, respectively), which are also positive for MMP-2. In situ zymography shows gelatinolytic activity in the glioblastoma tissues but not in the normal brain tissues. These results suggest that both MT1-MMP and MT2-MMP play a key role in the activation of pro-MMP-2 in the human malignant astrocytic tumors and that the gelatinolytic activity is involved in the astrocytic tumor invasion.

Adenocarcinoma↗
PubMed1999

Axonal and perikaryal involvement in chronic inflammatory demyelinating polyneuropathy.

OBJECTIVES: To assess the extent of loss of myelinated nerve fibres and spinal motor neuron loss in chronic inflammatory demyelinating polyneuropathy (CIDP), a clinicopathological study was conducted on biopsied sural nerves and necropsied spinal cords from patients with CIDP. METHODS: The myelinated fibre pathology of 71 biopsied sural nerves and motor neuron pathology of nine necropsied spinal cords at L4 levels in patients with CIDP were quantitatively and immunohistochemically assessed. RESULTS: Myelinated nerve fibre density was significantly diminished to 65.4% of the control values (p <0.0001), correlating inversely with the extent of segmental demyelination and remyelination (r = -0.43, p < 0.0005) and duration of illness (r = -0.31, p < 0.01). Numbers of large spinal motor neurons in CIDP were variably but significantly diminished (range from 46.0 to 97.6% of the age matched control value (p < 0.005)), and reactive astrogliosis was evident in the ventral horn in CIDP. The frequency of ventral horn neurons exhibiting central chromatolysis and the accumulation of phosphorylated high molecular weight neurofilament protein was significantly higher in CIDP than in controls (p<0.01 and p<0.05). CONCLUSIONS: The loss of nerve axons and spinal motor neurons is common in CIDP, and extensive in some cases. These neuronal and axonal losses may influence the functional prognosis in CIDP.

Adolescent↗
PubMed1999

Cytogenetic aberrations detected by flow cytometry and fluorescence in situ hybridization in colorectal cancers: two cytogenetic pathways in colorectal carcinogenesis.

We measured DNA content by flow cytometry and determined the number of chromosomes 7, 17 and 18 by fluorescence in situ hybridization using DNA probes in 38 sporadic colorectal adenocarcinomas including 14 early cancers. Based on DNA ploidy and the copy number of chromosome 18, colorectal cancers were divided into two groups. In early cancers (mucosal and submucosal adenocarcinomas), monosomy 18 with DNA hypotriploidy was detected exclusively in 6 sessile tumors without adenoma portions. Seven of the remaining 8 tumors in which adenoma portions coexisted manifested disomy 18 and DNA diploidy or near diploidy. These tumors were considered to occur along the adenoma-carcinoma sequence. In contrast, monosomy 18 was accompanied by DNA diploidy or near diploidy in advanced cancers penetrating the muscularis propria. In advanced cancers, DNA hypertriploidy was linked with disomy 18 and chromosomes 7 and 17 were trisomic or tetrasomic. Observations indicate at least two different cytogenetic pathways in colorectal carcinogenesis. According to these findings, two thirds of advanced cancers were estimated to originate from adenoma, and the others were not.

Adenoma↗
PubMed1999

[A report of two cases suggesting positive influence of pregnancy on uveitis activity].

BACKGROUND: Little is known about the influence of pregnancy on uveitis activity. We report two cases suggesting a favorable influence of pregnancy on the clinical course of uveitis. CASE: A 30-year-old woman who was three months pregnant was suspected Vogt-Koyanagi-Harada disease based on the systemic symptoms and ocular findings of iritis and multi-focal serous retinal detachment. She was positive to human leukocyte antigen (HLA)-DR 4. She was treated only with topical corticosteroids. One month later, the retinal detachment disappeared. Six month later, a healthy baby was born. The fundus of both eyes took on a sunset glow appearance and there has been no recurrence of uveitis. The other case was a 23-year-old woman with Behçet's disease who had several episodes of uveitis in a year even on tacrolimus. Because of pregnancy, all systemic drugs including tacrolimus were discontinued since then. Interestingly, the frequency of uveitis was remarkably decreased during the pregnancy. A normal healthy baby was born. The uveitis has almost completely disappeared since parturition until now. CONCLUSION: It is considered that the increase of intrinsic hormone, especially corticosteroid, and some other factors with pregnancy may give the suppressive influence on uveitis in our cases.

Adult↗
PubMed1999

Multiple rheumatoid papules characteristic of the early stage of rheumatoid vasculitis.

The rheumatoid papule has recently been described as the skin manifestation of rheumatoid arthritis (RA). The papules represent leukocytoclastic vasculitis and necrobiosis clinicopathologically. We report a 59-year-old Japanese woman with multiple recurrent rheumatoid papules located on the bilateral extensor forearms in correlation with the level of RA activity and as a cutaneous manifestation of rheumatoid vasculitis. These papules appeared prior to other cutaneous manifestations. It was suggested that rheumatoid papules represent the early stage of rheumatoid vasculitis and that they are a reliable early clinical marker of rheumatoid vasculitis.

Arthritis, Rheumatoid↗
PubMed1999

Age-related changes in the cerebral distribution of 99mTc-ECD from infancy to adulthood.

UNLABELLED: Although cerebral blood flow in infants differs from that in older individuals, the distribution of 99mTc-ethyl cysteinate dimer (ECD) in infants has not been well studied. This study compared 99mTc-ECD distribution in infants and children with that in young adults. METHODS: 99mTc-ECD SPECT was performed on 37 patients suspected of having epilepsy, ranging in age from 3 mo to 26 y. The patients were divided into two age-matched groups, a drug-free group (n = 19) and a drug-taking group (n = 18), according to their anticonvulsant medication status at the time of examination. 99mTc-ECD (100-740 MBq) was injected interictally, and SPECT data were acquired using a triple-head gamma camera. Mean whole-brain counts were obtained from 10 sequential SPECT images. Regions of interest were set bilaterally on five areas of the cerebral cortex and on the basal ganglia, thalamus and cerebellum. The brain perfusion index (BPI) was obtained as a ratio of the mean counts in each region of interest to the mean whole-brain counts. The relationship between BPI and age in each region in the drug-free and drug-taking groups was analyzed separately and together using linear regression. The relationship between five patient age groups (<1 y, n = 4; 1-4 y, n = 9; 5-9 y, n = 8; 10-15 y, n = 7; >15 y, n = 9) and BPI in each region was also examined using multiple comparison analyses. RESULTS: Significant positive correlations between BPI and age in the frontal cortex and cerebellum were confirmed in the drug-free group. Anticonvulsant drugs did not affect the regression lines of BPI in the frontal cortex and cerebellum. Significant differences in BPI between age groups were seen in the parietal cortex, frontal cortex, occipital cortex, basal ganglia, thalamus and cerebellum in all patients. CONCLUSION: Age-related changes in cerebral 99mTc-ECD distribution were confirmed and found to be unaffected by the administration of anticonvulsant drugs. 99mTc-ECD uptake in children and infants is different from cerebral blood flow glucose metabolism as previously reported, especially in the cerebellum.

Adolescent↗