Biomedical subjects

I Tooyama

Publications and source records attributed to I Tooyama.

103 records · Page 6Linked to original sources

PubMed1991

Acidic fibroblast growth factor-like immunoreactivity in brain of Alzheimer patients.

Localization of acidic fibroblast growth factor (aFGF)-like immunoreactivity was examined in postmortem human brain tissue of Alzheimer and age-matched control cases using a rabbit polyclonal antibody specific for aFGF. In control cases, a small number of glial cells were stained very weakly in white but not in gray matter. In Alzheimer cases, some astrocytes were strongly stained for aFGF in both gray and white matter. These intensely staining cells were frequently observed surrounding senile plaques, but represented a small proportion of the total astrocytic population. The present study suggests that aFGF may be upregulated in areas of Alzheimer pathology.

Aged↗

PubMed1991

Phylogenetic study of serotonin-immunoreactive structures in the pancreas of various vertebrates.

The distribution pattern of serotonin (5HT) in the pancreas was studied immunohistochemically by using a 5HT monoclonal antibody in various vertebrates including the eel, bullfrog, South African clawed toad, turtle, chicken, mouse, rat, guinea-pig, cat, dog and human. In all species examined, except the bullfrog, 5HT-like immunoreactivity was observed in nerve fibers, in endocrine cells, or in both. Positive nerve fibers were found in the eel, turtle, mouse, rat and guinea-pig. These fibers ran mainly along the blood vessels and partly through the gap between the exocrine glands. In the eel and guinea-pig, positive fibers invaded the pancreatic islet. Occasionally, these positive fibers were found adjacent to the surface of both exocrine and endocrine cells, suggesting a regulatory role of 5HT in pancreatic function. 5HT-positive endocrine cells were observed in the pancreas of all species except for the bullfrog and rat. In the eel and in mammals such as the mouse, guinea-pig, cat, dog and human, 5HT-positive cells were mainly observed within the pancreatic islet. In the South African clawed toad, turtle and chicken, the positive cells were mainly in the exocrine region. The present study indicates that the distribution patterns of 5HT in the pancreas varies considerably among different species.

Amphibians↗

PubMed1991

Light and electron microscopy of neuropeptide Y-containing nerves in human liver, gallbladder, and pancreas.

Neuropeptide Y-containing nerve fibers were identified by light and electron microscopic immunocytochemistry in the human liver, gallbladder, and pancreas. In the liver, neuropeptide Y-containing nerve fibers were distributed richly in Glisson's sheath and were prominent around the walls of the interlobular vein, interlobular hepatic artery, and hepatic bile duct. The fibers also formed a dense network surrounding the hepatocytes. The nerve terminals were found close to the endothelial cells of blood vessels, as well as being distributed in Disse's space, where they appeared to terminate. Occasionally these terminals contacted directly the membrane of a hepatocyte. In the gallbladder, neuropeptide Y fibers were found in each layer, with an especially dense network in the lamina propria. The fibers also ran close to the epithelium and parallel to the muscle bundles. Blood vessels throughout the gallbladder were well supplied with such nerve fibers. In the pancreas, neuropeptide Y fibers were found mainly near blood vessels and partly in gaps between exocrine glands, seeming to terminate on certain endocrine cells. Nerve terminals were located in the vascular walls and adjacent to the surface of exocrine acinar cells. These studies provide a basis for correlating the neuropeptide Y distribution with pharmacological and physiological studies in humans.

Gallbladder↗

PubMed1991

Production of antisera to acidic fibroblast growth factor and their application to immunohistochemical study in rat brain.

Antisera against acidic fibroblast growth factor purified from bovine brain were produced in rabbits and used for immunohistochemical study of the rat brain. When examined in an immunospot assay using a nitrocellulose membrane, the best antibody was capable of detecting 80 fmol of acidic fibroblast growth factor but failed to react even with up to 5 pmol of basic fibroblast growth factor. Using this antiserum, the immunohistochemical distribution of acidic fibroblast growth factor was examined in rat brain. Acidic fibroblast growth factor-like immunoreactivity was localized mainly in a subpopulation of ependymal cells and tanycytes, as well as in some glial cells. Positive ependymal cells were observed throughout the walls of ventricles, including the third ventricle and cerebral aqueduct. Immunoreactive processes of tanycytes were found extending from the ventral wall of the third ventricle to the brain parenchyma and surface. The most intense immunostaining was observed in circumventricular organs such as the organum vasculosum laminalis terminalis and the subfornical organ. Particularly in the latter organ, there was an extremely dense plexus of immunoreactive fibers and processes around the wall of capillaries. The present results suggest that the effects of acidic fibroblast growth factor on brain functions may be exerted through the circumventricular organs and/or ependymal cells.

Animals↗

PubMed1991

[A case of schwannomatosis--clinical, pathological and biochemical studies].

A case of schwannomatosis is described, including clinical, pathological and biochemical features. A 16-year-old male patient was admitted because of multiple subcutaneous tumors without family history. No café au lait spots were found. Magnetic resonance images (MRI) revealed multiple tumors of cranial and spinal nerves. The tumors in the scalp, right forearm and left spinal nerve at the level of C5 were excised out surgically. The pathological study of all tumor specimens showed a typical appearance of schwannoma with Antoni A and B tissues but not that of neurofibroma. Electrophoretic study of the extract from the tumor detected a basic protein at a molecular weight of 18.5 KD, which has been reported to be a tumor marker protein of benign schwannoma. From these findings, this patient had the features of schwannomatosis, clearly distinguished from those of neurofibromatosis.

Adolescent↗

PubMed1990

Choline acetyltransferase immunopositive neurons in the lateral septum.

A small cluster of choline acetyltransferase (ChAT)-positive neurons was identified immunohistochemically in rat and monkey brain in the ventral portion of the lateral septal nucleus. These multipolar neurons were smaller and much less intensely staining than the medial septal nucleus ChAT-immunopositive group.

Animals↗

PubMed1990

Reactive microglia express class I and class II major histocompatibility complex antigens in Alzheimer's disease.

Expression of major histocompatibility complex (MHC) class I (HLA-A,B,C) and class II (HLA-DR) antigens was studied in postmortem brain tissue of Alzheimer's disease and age-matched control cases. Monoclonal antibodies to class I antigens stained reactive microglia weakly to moderately and vascular endothelial cells strongly in Alzheimer's gray and white matter. Capillaries were also stained strongly in control brains, but only a few positively stained microglia could be observed in white matter. In Alzheimer cases, HLA-DR positive reactive microglia were more numerous and more strongly staining than MHC class I positive reactive microglia but many cells appeared to express both classes of antigen. Rare large cells of uncertain origin also stained positively for class I. Double immunostaining established that MHC class I positive cells were a separate population from glial fibrillary acidic-protein-positive astrocytes.

Antibodies, Monoclonal↗

PubMed1990

Isolation of glutamyltaurine from bovine brains and proof of its gamma-linkage by the B/E linked scan SIMS technique.

We isolated a glutamyltaurine from bovine brains and determined its structure as gamma-glutamyltaurine (gamma-Glu-Tau; glutaurine) by use of a new mass spectrometric technique [B/E linked scan sputtered ion mass spectrometry (SIMS)], which we have recently shown to be useful for distinguishing the gamma- from the alpha-isomer of glutamyl-dipeptides. Neither the alpha-isomer of glutamyltaurine nor any aspartyltaurines could be detected in bovine brain.

Animals↗

PubMedDate not supplied

Immunohistochemical study of alpha 2 macroglobulin receptor in Alzheimer and control postmortem human brain.

Localization of the alpha 2 macroglobulin receptor (alpha 2MR) was studied in postmortem human brain tissue of Alzheimer disease (AD) and age-matched control cases with a monoclonal antibody (A2MR alpha 2) to the receptor. In control cases alpha 2MR was detected in neurons, glia, and some capillaries. Neuronal staining was most conspicuous in the hippocampus and entorhinal cortex. In AD, alpha 2MR immunoreactivity was enhanced. The staining intensity of some neurons was increased, as was the number of positive glial cells. In addition, senile plaques, tangles, and dystrophic neurites were strongly stained. These results suggest that alpha 2MR is involved in AD pathology.

Aged↗

PubMedDate not supplied

Effects of fibroblast growth factors and platelet-derived growth factor on food intake in rats.

In the present study, the relations between acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), platelet-derived growth factor (PDGF), and food intake were studied. When aFGF-, bFGF-, and PDGF-like activity in cerebrospinal fluid (CSF) was examined by bioassay, the activity of those factors significantly increased in postfeeding CSF, compared to prefeeding CSF. Injections of aFGF, bFGF, aFGF (synthetic amino-terminal peptide of aFGF), and PDGF into the third cerebral ventricle decreased food intake, and injections of anti-aFGF, anti-bFGF, and anti-aFGF antibodies into the lateral hypothalamus (LHA) increased food intake. The activity of LHA glucose-sensitive neurons was inhibited by electrophoretic application of aFGF. These results suggest that aFGF, bFGF and PDGF have in vivo physiological roles in the central nervous system, distinct from those as mitogens.

Animals↗

PubMedDate not supplied

Effect of acidic fibroblast growth factor on basal forebrain cholinergic neurons in senescence-accelerated mice.

We examined the effects of chronic administration of acidic fibroblast growth factor (aFGF) on memory and choline acetyltransferase (ChAT) immunoreactivity in the forebrain of senescence-accelerated mice (SAMP8 strain). Subcutaneous injection of aFGF (aFGF group) or saline vehicle (saline group) once a week into SAMP8 was begun at three weeks after birth and continued for nine months. In the passive avoidance test, the retained latency was significantly longer in the aFGF group than in the saline group. In the Morris test, the mean latency to climb on a platform was significantly shorter in the aFGF group than in the saline group. The number of ChAT-positive neurons in the forebrain septum was greater in the aFGF group than in the saline group, and was at the level of that in the control mouse strain (SAMR1). The intensity of ChAT staining in the aFGF group appeared slightly weaker than in SAMR1 but significantly stronger than in the saline group. The results indicate that the effect of aFGF on memory function in SAMP8 may be related to the preservation of function in septal cholinergic cells.

Aging↗

PubMedDate not supplied

Correlation of the expression level of C1q mRNA and the number of C1q-positive plaques in the Alzheimer Disease temporal cortex. analysis of C1q mrna and its protein using adjacent or nearby sections.

We compared the expression level of C1q mRNA and the number of C1q-positive plaques in adjacent or nearby brain sections from Alzheimer disease (AD) and control cases. Small blocks of temporal cortex were fixed with 4% paraformaldehyde for 2 days at 4 degrees C. After cryoprotection with solutions containing 10-20% glycerol and 2% dimethylsulfoxide, 40-microm sections were cut from the tissue blocks. A section from each case was stained by immunohistochemistry using a C1q antibody, while RNA was purified from adjacent or nearby sections using a combination of proteinase K pretreatment followed by extraction using Trizol reagent. The expression of C1q B chain mRNA was analyzed in these samples by the reverse-transcription polymerase chain reaction (RT-PCR). The intensities of the PCR products were measured by an image analyzer. The expression of C1q B chain mRNA was significantly more abundant in AD than in control cases (p < 0.05). Immunohistochemical analysis showed that C1q protein was localized in senile plaques in the AD brain. The number of C1q-positive plaques correlated with the expression level of C1q gene (p < 0.05). The present results suggest that C1q protein in senile plaques originates is endogenously produced in the AD brain.

Aged↗

PubMedDate not supplied

Fate of (D-Ala2)-deltorphin-I-like immunoreactive neurons in 6-hydroxydopamine lesioned rat brain.

The use of a polyclonal antiserum specific to C-terminal tetrapeptide amide of (D-Ala2)deltorphin-I, a naturally occurring amphibian skin opioid peptide, has already demonstrated the presence of immunoreactive neurons in rat midbrain. Double immunostaining identified these neurons as a subpopulation of the mesencephalic dopaminergic neurons that were also tyrosine hydroxylase-immunopositive and calbindin-D28kD- negative, namely, the neurons predominantly affected in Parkinson disease. We followed the fate of these neurons after a monolateral injection of 6-hydroxy-dopamine into rat brain. Almost all the immunopositive neurons and their nigrostriatal, mesolimbic and mesocortical projections on the side ipsilateral to the lesion disappeared. Only a few scattered immunopositive neurons within the substantia nigra, pars compacta, and those of supramammillary nucleus remained unaffected. The consistent overlap of dopamine and this new molecule provides a further key to identifying the mammalian counterpart of these amphibian skin opioid peptides.

Animals↗