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T Imagawa

Publications and source records attributed to T Imagawa.

At least 19 recordsLinked to original sources
PubMed2006

Expression of lactate dehydrogenase-A and -B messenger ribonucleic acids in chick glycogen body.

Glucose is a main metabolic substrate in the central nervous system (CNS). Recently, lactate has attracted renewed attention because it plays an important role in the CNS as a metabolic substrate between neurons and astrocytes. Lactate and lactate dehydrogenase (LDH), a key enzyme for lactate and pyruvate interconversion, have been investigated. The glycogen body (GB) is a gelatinous tissue in the dorsal area of the lumbosacral spinal cord in birds. It is composed of uniform cells with high glycogen storage and is thought to be in the astroglia lineage. In this article, we investigated the LDH enzyme activity in embryo GB (embryonic d 12, 14, 16, 17, and 18) and chickens. To detect the subtype of the LDH, mRNA expressions in GB were investigated and compared with those of cerebral cortex and spinal cord. By histochemical observations, LDH enzyme activity was detected in the cytoplasm of GB cells of all embryonic periods after embryonic d 12. In biochemical analysis, the enzymatic activities of the GB were higher than in the cerebral cortex. In the GB the subtype of LDH mRNA was LDM-B only, and in the cerebral cortex and spinal cord, the subtype of LDH mRNA was predominantly LDH-B, and a small amount of LDH-A was found in the chicken and embryo. The LDH-B mRNA expression in GB was detected during all periods of the study (after embryonic d 12). These observations suggest that GB expressed only LDH-B and that GB cells are not lactate-producing cells, like astrocyte, but rather are lactate-consuming cells, similar to neurons in CNS.

Animals↗
PubMed2006

Glomerulonephritis in children with mixed connective tissue disease.

AIMS: Mixed connective tissue disease (MCTD) has overlapping clinical features with systemic lupus erythematosus (SLE). Renal biopsy is necessary for all children with SLE to evaluate the prognosis, because they are at a quite high risk of developing renal complications. Furthermore, lupus nephritis and hypocomplementemia usually precede the appearance of clinical manifestations. Immune complex-mediated nephritis is one of the major complications of MCTD. Juvenile MCTD is known to be associated with a higher risk of nephritis than adult MCTD. However, it is uncertain whether all children with MCTD should be subjected to a renal biopsy, and whether most of those with hypocomplementemia present nephropathy, as in patients with SLE. We examined the histopathological characteristics of juvenile MCTD nephritis, the importance of renal biopsy and the implications of hypocomplementemia in our patients and reported cases of MCTD. MATERIAL AND METHODS: We performed renal biopsy in 11 children with MCTD and found 6 patients with glomerulonephritis. In addition, we studied the frequency and the characteristics of glomerulonephritis in 71 cases of juvenile MCTD (our 11 patients and 60 reported cases). We also analyzed the relationship between hypocomplementemia and pathological features in 41 cases of MCTD nephritis (23 adults, 18 children). RESULTS: 6 of our 11 patients had glomerulonephritis, but of them four had no abnormality in urinalysis at the time of biopsy. In 5 patients renal biopsy showed normal findings. Review of 71 cases of juvenile MCTD showed that of them 28% presented latent asymptomatic nephritis at the time of biopsy. Membranous nephropathy (MN) and mesangial proliferative glomerulonephritis (MPG) were common in MCTD. Interestingly, hypocomplementemia was more frequently observed in patients with MN or mixed form of MN and MPG (MPG/MN) than simple MPG based on our review of 41 cases (p < 0.01). CONCLUSION: A more aggressive indication of renal biopsy should be considered in children with MCTD because of the high incidence of non-clinical nephritis. The hypocomplementemia observed in patients with MCTD suggests the high frequency of glomerulonephritis, including membranous lesions.

Adolescent↗
PubMed2006

[Completion pneumonectomy for pulmonary aspergillosis with hyper immunoglobulin-E syndrome].

A 22-year-old man was admitted to the department of pediatrics of our institute in February 2005, because of pulmonary aspergillosis. He had been diagnosed as hyper immunoglobulin-E syndrome in infancy, and repeated pulmonary infectious desease, such as pulmonary aspergillosis. He received art of right upper lobectomy by pulmonary aspergillosis at the age of 17. In February 2005, he had hemosputum and the chest X-ray showed a giant cavity with niveau in the right lung. In spite of medical treatment by antibiotics and antimycotics, the lesion rapidly increased in size. Therefore, right completion pneumonectomy and omentopexy around the bronchial stump was done. His postoperative course was uneventful.

Adult↗
PubMed2006

[Right atrial blood cyst; report of a case].

A 53-year-old female was admitted to our hospital for examination of an abnormal shadow on chest X-ray. Computed tomography (CT) revealed a large mass of 3 cm in diameter in the right atrium. The mass arose from the right atrial septum and was removed with the interatrial septum. Histological specimen showed a blood cyst contained serous effusion.

Cysts↗
PubMed2005

[Intraoperative frozen section diiagnosis of small peripheral lung adenocarcinoma for limited operation].

Sixty-two cases of peripheral lung adenocarcinoma 2 cm or less in diameter were diagnosed as type A, B, or C according to Noguchi classifications by intraoperative frozen section diagnosis. Four of 19 type A were changed finally to type B by postoperative pathologic examination. Likewise 10 of 34 type B were changed finally to 1 type A, 8 type C, and 1 type D. Three of 9 type C were changed finally to 2 type B and 1 type D. Frozen section diagnosis for small peripheral lung adenocarcinoma has some special problems and limitations. Only cases of type A diagnosed by frozen section diagnosis should be permitted to undergo limited surgical resection.

Adenocarcinoma↗
PubMed2004

Distribution of PCBs, HCHs and DDTs, and their ecotoxicological implications in Bay of Bengal, India.

Analyses of environmentally persistent pollutants like polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, and dichlorodiphenyltrichloroethane (DDT) and its metabolites in seawater and sediment samples collected from six locations along the east coast of India were carried out using High-Resolution Gas Chromatograph with High-Resolution Mass Spectrometer (HRGC-HRMS). Sediment and water from Chennai harbour and Cuddalore fishing harbour contained higher concentration of all the compounds. The highest concentration (6570 pg/g dry weight) of total PCB was found in sediment from Chennai harbour followed by sediments sampled in Chennai (opposite to Cooum River mouth) (505 pg/g), Cuddalore fishing harbour (335 pg/g) and Mandapam (251 pg/g). Concentrations in other locations were two orders of magnitude lower than Chennai harbour. A distinct PCB distribution pattern in sediment was observed between harbours and other locations. Greater concentrations of tetra-, penta- and hexachlorobiphenyls were observed in sediments of harbours and opposite to Cooum river mouth, but in other locations lower chlorinated biphenyls (di, tri and tetra-) were more. In seawater, HCH concentration was greater than DDT, but it was quite opposite in sediments. Elevated levels of DDT in sediment were observed only at highly populated urban locations, reflecting the local usage and input of this pesticide. Based on sediment/water quality criteria/guidelines, some coastal locations of the Bay of Bengal could be designated as being polluted by DDTs and gamma-HCH (lindane), but not by PCBs. This investigation reveals the declining trend on the environmental burden of persistent pesticides in Indian marine environment. Data on the organochlorine concentrations found in this survey can be used as reference levels for future POPs monitoring programme.

Animals↗
PubMed2001

Effects of combustion temperature on PCDD/Fs formation in laboratory-scale fluidized-bed incineration.

Combustion experiments in a laboratory-scale fluidized-bed reactor were performed to elucidate the effects of combustion temperature on PCDD/Fs formation during incineration of model wastes with poly(vinyl chloride) or sodium chloride as a chlorine source and copper chloride as a catalyst. Each temperature of primary and secondary combustion zones in the reactor was set independently to 700, 800, and 900 degrees C using external electric heaters. The PCDD/Fs concentration is reduced as the temperature of the secondary combustion zone increases. It is effective to keep the temperature of the secondary combustion zone high enough to reduce their release during the waste incineration. On the other hand, as the temperature of the primary combustion zone rises, the PCDD/Fs concentration also increases. Lower temperature of the primary combustion zone results in less PCDD/Fs concentration in these experimental conditions. This result is probably related to the devolatilization rate of the solid waste in the primary combustion zone. The temperature decrease slows the devolatilization rate and promotes mixing of oxygen and volatile matters from the solid waste. This contributes to completing combustion reactions, resulting in reducing the PCDD/Fs concentration.

Benzofurans↗
PubMed2001

An isomer prediction model for PCNs, PCDD/Fs, and PCBs from municipal waste incinerators.

Isomer patterns of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzofurans (PCDFs) from municipal waste incinerators (MWIs) were predicted by a model based on symmetry numbers and preferential chlorination positions. Fly ash isomer patterns from five stoker and seven fluidized bed incinerators were compared to validate the prediction model. The isomer patterns of the highly chlorinated PCN homologues from stoker type incinerators were successfully predicted. The relative equilibrium concentrations of tetrachloronaphthalenes (TeCNs), calculated by an ab initio method, cannot explain the field isomer patterns. Formation pathways involving chlorophenol precursor condensation reactions should be examined to see whether these isomer patterns provide a better fit to the field PCDD data. The PCB isomer patterns were fit reasonably well, but this finding could merely be an artifact of the limited data and the large number of isomers. The prediction equations of PCDFs, revised from prior work to include a symmetry number for each isomer, represented the field data patterns for the higher chlorinated isomers very well. Successful prediction of isomer patterns for partial homologue ranges suggests that these patterns are determined by a mechanism governed by Cl-position-specific preferences.

Benzofurans↗
PubMed2001

Polychlorinated naphthalenes, -biphenyls, -dibenzo-p-dioxins, and -dibenzofurans in double-crested cormorants and herring gulls from Michigan waters of the Great Lakes.

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), naphthalenes (PCNs), and biphenyls (PCBs) were measured in eggs of double-crested cormorants and herring gulls collected from Michigan waters of the Great Lakes. Concentrations of PCNs in eggs of double-crested cormorants and herring gulls were in the ranges of 380-2400 and 83-1300 pg/g, wet wt, respectively. Concentrations of 2,3,7,8-substituted PCDDs and PCDFs were 10-200 times less than those of PCNs in eggs whereas those of total PCBs (380-7900 ng/g, wet wt) were 3-4 orders of magnitude greater. While the profile of PCB isomers and congeners between double-crested cormorants and herring gulls was similar, the PCN isomer profile differed markedly between these two species. PCN congeners 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) accounted for greater than 90% of the total PCN concentrations in herring gulls, whereas their contribution to total PCN concentrations in double-crested cormorants ranged from 18 to 40% (mean, 31%). The ratios of concentrations of PCDDs to PCDFs were greater in herring gulls than in double-crested cormorants collected from the same locations, suggesting the ability of the former to metabolize PCDF congeners relatively rapidly. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TEQs) contributed by PCNs in double-crested cormorant and herring gull eggs were 2-3% of the sum TEQs of PCBs, PCDDs, PCDFs, and PCNs. PCB congener 126 (3,3',4,4',5-PeCB) accounted for 57-72% of the total TEQs in double-crested cormorant and herring gull eggs.

Animals↗
PubMed2001

Laterality of the spinocerebellar axons and location of cells projecting to anterior or posterior cerebellum in the chicken spinal cord.

In the cervical and lumbosacral enlargements of the chicken, there are seven spinocerebellar nuclei, the Clarke's column, the spinal border cells, the ventral margin of the ventral horn of both enlargements, and the ventral marginal nucleus in the lumbosacral enlargement. In the present study, we investigated the laterality of spinocerebellar tract axons and the distribution of the spinocerebellar tract neurons projecting into the anterior or posterior part of the cerebellum in these seven nuclei by retrograde transport of wheat germ agglutinin-horseradish peroxidase. The spinocerebellar tract neurons with uncrossed axons were found in the cervical Clarke's column and the cervical spinal border cells, and with crossed ones in the lumbar Clarke's column, lumbar spinal border cells, lumbar lamina IX included in the ventral margin of the ventral horn of the lumbosacral enlargement, and the ventral marginal nucleus. The ventral margin of the ventral horn of the cervical enlargement and lumbar lamina VIII included in the ventral margin of the ventral horn of the lumbosacral enlargement issued spinocerebellar tract axons bilaterally. The spinocerebellar tract neurons of the lumbar spinal border cells and lumbar lamina IX projected to the anterior part of the cerebellum only. And those of the other nuclei projected to both the anterior and posterior parts.

Animals↗
PubMed2001

Expression of angiogenic factors in juvenile rheumatoid arthritis: correlation with revascularization of human synovium engrafted into SCID mice.

OBJECTIVE: Although increased vascularity was noted in early histopathologic studies of juvenile rheumatoid arthritis (JRA) synovium, the available data on angiogenesis in JRA are very limited. The main purposes of this study were to assess expression of the key angiogenic factors in JRA synovium, and to evaluate a SCID mouse model of JRA as an approach to study in vivo regulation of the expression of these factors in JRA. METHODS: RNase protection assay was used to assess the expression of the key angiogenic factors in fresh JRA synovium and in JRA synovial tissue fragments that had been minced and then implanted into SCID mice. Vascularity of the samples was assessed by immunohistochemical staining for von Willebrand factor. Synovial specimens obtained from patients with osteoarthritis (OA) or other noninflammatory arthropathies were used as controls. RESULTS: Detectable levels of messenger RNA for vascular endothelial growth factor and angiopoietin 1 and their respective receptors, as well as endoglin and thrombin receptors, were present in all JRA tissue specimens studied. The levels of expression of these factors in JRA tissues were significantly higher than those in tissues obtained from patients with OA or other noninflammatory arthropathies. Furthermore, increased expression of the key angiogenic factors in the fresh JRA tissues correlated with the exuberant revascularization of JRA minced tissue fragments implanted into SCID mice. This was in sharp contrast to the poor revascularization of implanted OA tissues. CONCLUSION: JRA synovium is characterized by high angiogenic activity. SCID mouse-human JRA synovium chimeras may provide a good approach to study the in vivo regulation of angiogenesis in JRA.

Angiopoietin-1↗
PubMed2001

Comparison of DNA sequence and transactivation activity of open reading frame 62 of Oka varicella vaccine and its parental viruses.

When nucleotide sequences of Oka vaccine and its parental viruses of varicella-zoster virus (VZV) were compared in 5 open reading frames (ORFs) including glycoprotein C (gC) and 4 immediate-early genes, mutations were detected only in gene 62 which is one of the immediate-early genes. Compared with its parental virus, the vaccine virus contained 15 nucleotide substitutions. With the differentiation method using the simplified restriction-enzyme fragment length polymorphism analysis by Nae I and Bss HII, which was established based on the sequence analysis data in this study, the Oka vaccine virus could be distinguished from its parental virus. Studies of the regulatory activities of the ORF62 gene product (IE62) in a transient assay indicate the IE62 of the parental virus had a stronger transactivational activity than that of the vaccine virus against immediate-early, early and late gene promoters. These data suggest that gene 62 might have an important role for attenuation of VZV. This is the first report in which many substitutions of nucleotides in gene 62 of Oka vaccine virus was found, compared with that of Oka parental virus.

Cell Line↗
PubMed2001

Correlation of polychlorinated naphthalenes with polychlorinated dibenzofurans formed from waste incineration.

Isomer composition of polychlorinated naphthalenes (PCNs) was measured for municipal waste incinerator fly ash samples and for emission samples produced from soot and copper-deposit experiments conducted at the United States Environmental Protection Agency (US-EPA). Two types of PCN isomer patterns were identified. One pattern contained specific PCN isomers in which chlorine atoms are substituted as if the peri(alpha-) position were dechlorinated from the higher chlorinated PCNs one by one. In another pattern, the isomers had a tendency for the chlorine atoms to assume successive positions on the naphthalene ring, which may be caused by specifically oriented chlorination. Some of these isomers increased, together with several polychlorinated dibenzofuran (PCDF) and a few polychlorinated dibenzo-p-dioxin (PCDD) isomers. The ratios between some specific PCN, PCDF, and PCDD isomers measured for the fly ash samples agree with those obtained from the soot and copper-deposit experiments. The observations suggest that these isomers were formed possibly from de novo synthesis utilizing the carbon structure contained in soot under the catalytic effect of a copper compound. Typical isomers for PCNs and PCDFs produced from incineration emissions were identified.

Air Pollutants↗
PubMed2001

Formation of PCDF, PCDD, PCB, and PCN in de novo synthesis from PAH: mechanistic aspects and correlation to fluidized bed incinerators.

The difference of polychlorinated dibenzofurans (PCDF) isomer patterns between stoker type incinerators and some fluidized bed incinerators (FBI) is a key to understand the formation mechanisms in both types of incinerators. The total yield and the isomer patterns of PCDF, polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), and polychlorinated benzenes (PCBz) formed via de novo synthesis from polycyclic aromatic hydrocarbons (PAH) indicate that chlorinated aromatics in the FBI are formed as a result of PAH breakdown. The detailed analysis of the isomer patterns of PCDF, PCB and PCN gives a first insight into the transformation mechanism of the PAHs and the sequence of degradation, chlorination and oxygen insertion. The major chlorination takes part at the position of the C-C cleavage during degradation of the PAHs. Further chlorination of the hydrogen position of the former PAH takes part preferably in ortho-position to this chlorination or is directed by incorporated oxygen. A perylene structure in soot is proposed as basis for the observed PCDF pattern in the FBI. Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated phenols (PxCP) were formed in lower concentrations from the de novo experiments indicating an additional formation pathway for these compounds in the FBI.

Benzofurans↗
PubMed2001

MR imaging of murine arthritis using ultrasmall superparamagnetic iron oxide particles.

The objective of this work was to determine the ability of magnetic resonance (MR) imaging with ultrasmall superparamagnetic iron oxide (USPIO) particles to provide quantitative measures of inflammation in autoimmune arthritis. Mice were injected intravenously or intra-articularly with USPIO followed by magnetic resonance and histological assessment of the knee joint. Comparisons were made between MR microimages and histology in naïve mice and mice with collagen-induced arthritis.Following intravenous administration, accumulation of USPIO was observed in the popliteal lymph nodes, but not the joint. Administration of USPIO intra-articularly resulted in signal loss in the joint. The MR signal intensity could be quantified and correlated with iron staining in the synovial lining. A marked increase in USPIO uptake and a corresponding decrease in signal intensity were observed in arthritic, compared to naïve mice. Areas of focal signal loss corresponded to foci of iron staining by histology. These studies may provide a basis for the clinical application of USPIO in arthritis for assessing disease severity and monitoring response to therapy.

Animals↗
PubMed2001

Fine structure of the retino-optic nerve junction in the chicken.

The aim of this study is to investigate a fine structure of the retino-optic nerve junction in the chicken. We especially focused on the myelin sheaths and astrocytes in the intraocular optic nerve (ION) and its adjoining parts. A part of the axons of retinal nerve fiber layer (NFL) were myelinated. Ganglion cell axons were ensheathed by loose myelin in the NFL and by a compact one in the ION and optic nerve (ON). Myelin structure changed from loose type to a compact one within the very narrow NFL-ION junction. Loose myelin forming cells are dark type of oligodendrocytes in the retina. From the most peripheral ON to the choroidal part of ION, astrocytes contained abundant microtubules. The optic nerve around the lamina cribrosa is exposed to mechanical force during eye movement. It is suggested that these microtubules may perform the cytoskeletal function. Astrocytes in the retinal part of ION had longer processes filled with abundant gliofilaments. They may provide the mechanical support for the ganglion cell axons, which are exposed directly to intraocular pressure. Although astrocytes in the retinal level of ION extended their processes into the retina, their soma was never found in the retina.

Animals↗
PubMed2001

Distribution of reticulospinal neurons in the chicken by retrograde transport of WGA-HRP.

To determine the distribution of reticulospinal (RS) neurons in the chicken, WGA-HRP was injected into the cervical or lumbosacral enlargement either unilaterally or bilaterally. The brainstem reticular nuclei sent largely descending fibers to both the spinal enlargements. The mesencephalon (medial and lateral mesencephalic reticular formation) and the rostral pons (nucleus reticularis [n.r.] pontis oralis) project mainly to the cervical enlargement. RS neurons were mainly distributed from the pontomedullary junction to the rostral medulla including n. r. pontis caudalis and pars gigantocellularis, n. r. gigantocellularis, n. r. parvocellularis, n. r. paragigantocellularis, and n. r. subtrigeminalis. It is suggested that the majority of these neurons send axons at least as far as the lumbosacral enlargement. In the lower medulla, RS neurons were distributed in the dorsal and ventral parts of the central nucleus of the medulla.

Animals↗