Biomedical subjects

O Fujimori

Publications and source records attributed to O Fujimori.

At least 19 recordsLinked to original sources

PubMed2001

Age-dependent changes in HCNP-related antigen expression in the human hippocampus.

Hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from the young rat hippocampus, enhances the cholinergic phenotype development of the medial septal nucleus in vitro. In this study, we examined the HCNP-antigen distribution and the age-related changes in the number of positive cells in the hippocampus (obtained at autopsy from 74 subjects with no known neurological disorders). Immunohistochemical assay revealed that the immunopositive cells were GABAergic neurons and oligodendrocytes. They were first identified in the fetus at around 25 to 30 weeks and their number increased rapidly with advancing postconceptional age to reach maximal at the perinatal stage and in early postnatal life; it then decreased to the adult level by 10 years old. These results suggest that HCNP-related antigen may play important roles in the development and/or differentiation of the human hippocampus.

Adolescent↗

PubMed2001

Muscarinic cholinergic and glutamatergic reciprocal regulation of expression of hippocampal cholinergic neurostimulating peptide precursor protein gene in rat hippocampus.

Hippocampal cholinergic neurostimulating peptide, an undecapeptide originally isolated from the hippocampus of young rats, enhances acetylcholine synthesis in rat medial septal nucleus in vitro. Hippocampal cholinergic neurostimulating peptide is derived from the N-terminal region of its 21-kmol.wt precursor protein. The highest expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is in hippocampal pyramidal neurons. In an in vitro rat hippocampal slice, preparation in which electrical stimulation could be delivered to the Schaffer collateral-CA1 pyramidal cell synapse, semi-quantitative non-radioisotopic in situ hybridization, demonstrated that expression of the hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA is regulated by neuronal activity. Selective inhibition with pharmacological agents revealed that the constitutive hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA level can be up-regulated by D-(-)-2-amino-5-phosphono-valeric acid, and that activity-dependent transcription can be inhibited by tetrodotoxin, nifedipine, 6-cyano-7-nitroquinoxaline-2,3-dione, and scopolamine, but not by mecamylamine. These results indicate that septal cholinergic neurons and hippocampal glutamatergic neurons exert a reciprocal influence over the expression of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA in the hippocampus, and that the activity-dependent and constitutive expressions of hippocampal cholinergic neurostimulating peptide precursor protein messenger RNA may be regulated by different routes, involving calcium influx via L-type Ca(2+) channels and N-methyl-D-aspartate receptors.

Androgen-Binding Protein↗

PubMed2001

Electron microscopic cytochemical studies of anionic sites in the rat spleen.

The distribution patterns of the intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of endothelial cells (ECs) in blood vessels and reticular cells (RCs) in the splenic cord of the rat spleen were studied by an electron microscopic cytochemical method using polyethyleneimine (PEI) as a cationic probe. Spleens from adult male rats were perfusion-fixed with 0.5% glutaraldehyde -4% paraformaldehyde containing 0.05% cetylpyridinium chloride and then perfused with 0.5% PEI at pH 7.4. On the free surfaces (glycocalyx of the plasma membrane) of the ECs examined, distinct PEI-positive reactions were observed in blood vessels, such as trabecular arteries, central arteries, arterial capillaries, pulp veins and trabecular veins. These PEI-positive electron-dense substances in the trabecular arteries, central arteries, and trabecular veins took the shape of a band of 170-250 nm in thickness. On the other hand, the corresponding ultrastructure of the ECs lining the splenic sinuses and the RCs in the splenic cord showed exceedingly weak PEI reactions. The PEI-reactive deposits were significantly thinner than those in the above blood vessels. As the thickness of the electron-dense substances can be related to the density of the negative charge, these results suggest that there is a high intensity of negative charge on the free surfaces (glycocalyx of the plasma membrane) of ECs in blood vessels where blood cells and plasma pass into the red pulp or are discharged from the red pulp. In contrast, the splenic sinuses and RCs, which are the main components of the red pulp, contain weakly negative-charged sites. This may contribute to the microcirculation of the splenic blood vessels and elucidate the possible physiological functions of the spleen, such as blood storage.

Animals↗

PubMed2000

Lectin histochemistry of the canine anal glands.

The distribution and selectivity of complex carbohydrates in the canine anal glands were studied by means of lectin histochemistry, using PO-labeled lectins. The secretory epithelium of the anal glands and the excretory duct system exhibited large amounts of mainly neutral glycoproteins with various terminal sugars (alpha-D-mannose, beta-N-acetyl-D-glucosamine, alpha-N-acetyl-D-galactosamine, alpha-D-galactose, alpha-L-fucose, N-acetyl-neuraminic acid). Distinctly prominent in the secretion were alpha-L-fucose residues. This relatively hydrophobic sugar may in particular modify or control the viscoelastic properties of the anal gland mucus, so that a stable mucous coat of the rather dry faeces can be formed. In addition, it was obvious that the major part of the excretory duct system is also involved in secretion production, and that the essential function of the saccular dilatations of the excretory ducts is to ensure secretion maturation.

Acetylgalactosamine↗

PubMed1998

Histochemical analysis of sialic acids in the epididymis of the rat.

A variety of sialic acids contained in the rat epididymis were histochemically examined by means of lectin and pre-lectin methods by light microscopy. Epididymides from adult male Sprague-Dawley rats were fixed in Bouin's fluid and routinely embedded in paraffin wax. Hydrated sections were subjected either to the lectin methods using biotinylated Limax flavus, Sambucus nigra, Sambucus sieboldiana or Maackia amurensis lectins or to the selective periodate oxidation-phenylhydrazine-thiocarbohydrazide-silver protein-physical development technique with or without saponification. The present results revealed that principal cells in the initial segment and caput contain sialic acid linked to alpha2,6-galactose/N-acetylgalactosamine, whereas those in the corpus and cauda include the sialic acid alpha2,3-galactose sequence. Narrow and clear cells involve all the types of sialic acids examined. Basal and halo cells mainly contain sialic acid alpha2,3-galactose. 8- And/or 9-O-acetylated sialic acids were predominantly distributed in principal cells of the initial segment and proximal caput. These findings are taken to indicate that various sialic acids in the epididymis could participate in different physiological functions characteristic of the regions in this organ.

Animals↗

PubMed1998

Histochemical studies on sialic acids in the epididymis during post-natal development of the rat.

A variety of sialic acids contained in the rat epididymis during post-natal development were examined by means of lectin and carbohydrate histochemistry. Epididymides from male Sprague-Dawley rats on post-natal days 14, 21, 30, 39, 49, 56 and 70 were fixed in Bouin's fluid and embedded routinely in paraffin wax. Hydrated sections were subjected either to the lectin methods using biotinylated Sambucus sieboldiana lectin or Maackia amurensis lectin or to the selective periodate oxidation-phenylhydrazine-thiocarbohydrazide-silver protein-physical development technique with or without saponification. The results revealed that sialic acids appeared in the epididymal epithelium at day 14, followed by particular distribution patterns corresponding to cell differentiation during days 21-39. High-level O-acetylation of sialic acids was observed in the principal cells of the initial segment and proximal caput after day 39. These results suggest that sialic acids with different linkages and O-acetylation become adult in distribution at the 'differentiation' period under the influence of androgen, before spermatozoa reach the epididymal lumen. Such carbohydrates may be correlated, at least in part, with sperm-binding sialoproteins, which increase dramatically during the window between days 21 and 39.

Animals↗

PubMed1998

Effects of a triple enzyme digestion method on a diamine reaction for glycosaminoglycans of the rat aorta in electron microscopy.

Effects of a triple enzyme digestion method using glycosaminoglycans-degrading enzymes upon a diamine reaction have been tested for electron microscopic histochemical detection of glycosaminoglycans in extracellular matrix of the rat aorta. The triple enzyme digestion method consists of a sequence of chondroitinase B, testicular hyaluronidase and heparitinase. The results obtained by the present experimental and control studies indicated that dermatan sulfates, chondroitin sulfates (A and/or C) or heparan sulfates were apparently observed in various ultrastructural features of aortic extracellular matrix, such as bundle of collagen fibers and soluble matrix of interstitial space. Particularly, we found that both heparan sulfates and chondroitin sulfates (A and/or C) were detected in association with the basal lamina of smooth muscle cells and the external surface of elastic lamina, and in the latter heparan sulfates were frequently recognized as a mass, whereas chondroitin sulfates (A and/or C) were found intermittently along the external surface of elastic lamina. This suggests that the triple enzyme digestion method which combines the glycosaminoglycans-degrading enzymes with the diamine reaction can be postulated to represent efficient and useful technique for precise electron microscopic histochemical detection of the glycosaminoglycans in the extracellular matrix of the rat aorta.

Animals↗

PubMed1997

Cataractogenesis and lipid peroxidation in newborn rats treated with buthionine sulfoximine: preventive actions of melatonin.

The purpose of this study was to examine the influence of exogenously administered melatonin on cataract formation and lipid peroxidation in newborn rats treated with buthionine sulfoximine (BSO), a drug which inhibits the rate-limiting enzyme in glutathione (GSH) synthesis, gamma-glutamylcysteine synthase, thereby depleting animals of their stores of the important intracellular antioxidant, GSH. BSO (3 mmol/kg BW) was given for three consecutive days beginning on postnatal day 2; melatonin (4 mg/kg) was injected daily beginning on postnatal day 2 and continuing until the animals were killed (either day 9 or day 17 after birth). None of the control animals (rats treated with neither BSO nor with melatonin) developed lenticular opacification during the observation period. In the BSO-treated rats, 16 of 18 animals (89%) had observable cataracts when they were examined. In rats that received both BSO and melatonin, the incidence of cataracts was highly significantly decreased, i.e., only 3 of 18 rats (7%) had observable cataracts. In addition to cataracts, the level of lipid peroxidation products (malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA)) was examined in the lens, brain, liver, lung, and kidney of control and experimental animals. In BSO-treated rats, the lens, kidney, and lung exhibited increased levels of MDA plus 4-HDA relative to those measured in the control rats; these increases were reversed in the BSO-treated rats who were injected with melatonin daily. While BSO administration did not increase basal levels of MDA plus 4-HDA in either the brain or liver, melatonin reduced levels of lipid peroxidation products below those measured in the control rats (at 17 days after birth). The changes induced by melatonin are consistent with the free-radical scavenging and antioxidative properties of this indole.

Animals↗

PubMed1997

Lectin-binding glycoconjugates in the subfornical organ of the rat.

In the rat subfornical organ (SFO), lectin-binding glycoconjugates were histochemically examined by 9 biotinylated lectins using a streptavidin-biotin peroxidase system. The strong or moderate binding of Canavalia ensiformis (Con A), Lens culinaris (LCA) and Phaseolus vulgaris erythroagglutinin (ePHA) indicated overall distributions of high mannose, intermediate, hybrid N-linked, and non-bisected, bi/triantennate N-linked complex oligosaccharides in the rat SFO. Nonsialylated terminal N-acetylglucosamines were detected throughout this organ, as revealed by its stainabilities with Triticum vulgaris (WGA) and Limax flavus (LFA). In this organ, Ricinus communis (RCA-1) specifically bound to vessel-associated structures, whereas Arachis hypogaea (PNA) reacted with selected neurons in the central and rostral regions of this organ. Dolichos biflorus (DBA) and Ulex europaeus (UEA-1) did not stain any histologic structures in the rat SFO. The results obtained in this study provide a basis for comprehensive analyses of glycoconjugates in the rat SFO.

Animals↗

PubMed1996

Distribution of hippocampal cholinergic neurostimulating peptide (HCNP) immunoreactivity in the central nervous system of the rat.

Hippocampal cholinergic neurostimulating peptide (HCNP), an undecapeptide isolated from the hippocampal tissue of young rats, enhances the cholinergic development in explant cultures of medial septal nuclei. This report concerns the distribution of HCNP immunoreactivity in the central nervous system (CNS) of 11- and 28-day-old Wistar rats; two affinity-purified anti HCNP antibodies were used. Immunoblot analyses of extracts of different regions of the brain revealed a single 23 kDa band that corresponded to the presumed HNCP precursor protein. Immunostaining of the various CNS structures of the 28-day-old rats was more intense than in those of 11-day-old animals. HCNP immunoreactivity was detected in neurons as well as in glia cells, particularly oligodendroglia. The perikarya of neurons in the cerebral cortex, hippocampus, limbic cortex, caudate, putamen, arcuate nucleus of hypothalamus, trigeminal subnuclei, rostroventrolateral reticular nucleus and dorsal horn of the spinal cord were positively stained. In addition, nerve fibers and terminals in the hypothalamic subnuclei, zona incerta, thalamic subnucleus, caudate, putamen, locus coeruleus, trigeminal subnuclei, dorsal motor nucleus of the vagus, dorsal horn of the spinal cord and intermediolateral column also displayed HCNP immunoreactivity. These observations would suggest that HCNP and its related molecules may have multifunctional roles in the CNS.

Animals↗

PubMed1996

Distribution of hippocampal cholinergic neurostimulating peptide (HCNP)-like immunoreactivity in organs and tissues of young Wistar rats.

This report concerns the distribution of the hippocampal cholinergic neurostimulating peptide (HCNP) in tissues and organs of 11-day-old Wistar rats. HCNP, originally isolated and purified from the hippocampus of young rats, is an undecapeptide (acetyl-Ala-Ala-Asp-Ile-Ser-Gln-Trp-Ala-Gly-Pro-Leu). HCNP distribution was investigated by using immunohistochemical techniques, employing an affinity-purified rabbit antibody that specifically recognizes HCNP and its 21-kDa precursor protein. Positively stained cells were detected in a variety of tissues and organs, including salivary gland, small intestine, colon, pancreas, bronchiole, adrenal gland, testis, as well as several others. The nerve fibres around blood vessels of almost all organs expressed HCNP. Our results suggest that HCNP or its precursor, or both, may have a specific function not only in the central nervous system, but also in the peripheral nervous system, and possibly in certain specialized duct and gland cells as well.

Amino Acid Sequence↗

PubMed1996

Possible implication of hippocampal cholinergic neurostimulating peptide (HCNP)-related components in Hirano body formation.

We have previously demonstrated that hippocampal cholinergic neurostimulating peptide (HCNP)-related components accumulate in almost all Hirano bodies in Sommer's sector of the hippocampus of elderly individuals, and that the number of HCNP-positive Hirano bodies is greater in patients with Alzheimer's disease. Although Hirano bodies occur preferentially in the neuronal processes of the stratum pyramidale of the hippocampus, they can be seen occasionally as small inclusions, intermingled with neurofibrillary tangles and in association with senile plaques. Here we show that the small inclusions are also recognized by an anti-HCNP antibody, and by using immunoelectron microscopy demonstrate that these HCNP-positive inclusions, intermingled with tau protein-positive neurofibrillary tangles and beta-amyloid-positive senile plaques are indeed Hirano bodies. These findings strongly suggest that HCNP-related components may be involved in Hirano body formation.

Aged↗

PubMed1996

Histochemical analysis of acidic glycoconjugates in the endothelium lining the splenic blood vessels in the rat.

An electron microscopic analysis with specific histochemical stainings for acidic glycoconjugates was carried out to examine the endothelium lining blood vessels of the rat spleen. Histochemical staining performed was the postembedding high or low iron diaminethiocarbohydrazide-silver protein-physical development (HID or LID-TCH-SP-PD) method, with or without prior digestion with acidic glycoconjugate-degrading enzymes, such as heparitinase, testicular hyaluronidase, chondroitinase B and neuraminidase. The results indicated that the acidic glycoconjugates in the basal lamina of the endothelial cells lining the four types of blood vessel (central arteries, arterial capillaries, splenic sinuses and pulp veins) were heparan sulfate, chondroitin sulfate A and/or C, chondroitin sulfate B and sialic acid residues. In the endothelial cells lining the central arteries, arterial capillaries and pulp veins, the surface coat of the luminal plasma membrane included heparan sulfate, chondroitin sulfate A and/or C, chondroitin sulfate B and sialic acid residues, whereas the corresponding ultrastructure of the splenic sinuses was devoid of detectable amounts of acidic glycoconjugates. This suggests that such characteristic histochemical features of the endothelium in the four types of the splenic blood vessel can be related to the possible physiological functions of the spleen.

Animals↗

PubMed1995

Accumulation of hippocampal cholinergic neurostimulating peptide (HCNP)-related components in Hirano bodies.

We have previously isolated from the hippocampus of young rats a novel peptide termed 'hippocampal cholinergic neurostimulating peptide' (HCNP) which specifically enhances the cholinergic activity of the septohippocampal system in vitro. Cloning and base sequence analysis of HCNP-specific cDNA from rat and human cDNA libraries revealed that the 1.1 kDa peptide aligns at the N-terminal region of its 21 kDa precursor protein. An affinity-purified rabbit antibody to rat HCNP prepared by us recognizes the C-terminal domain of the peptide, while an antibody against human HCNP binds to a large portion of the peptide. In this report we show that both antibodies react with HCNP-related components present in the soluble cytosol fraction of human brain tissue. Immunohistochemical examination of human nervous system tissues from elderly individuals revealed that Hirano bodies in Sommer's sector of the hippocampus were specifically stained by anti-HCNP antibodies. The number of HCNP-positive Hirano bodies was greater in patients with Alzheimer's disease than in normal, age-matched individuals. The immunohistochemical results were substantiated by immunoelectron microscopy. The present findings indicate that HCNP-related components accumulate in Hirano bodies, suggesting that patients who bear these inclusions may have a disturbance of the septo-hippocampal cholinergic system, considered to be of importance for learning and memory formation.

Aged↗

PubMed1995

A new histochemical method for detection of sialic acids using a physical development procedure.

We have established an efficient histochemical method for demonstration of sialic acids in light microscopy. The method consists of a selective periodate oxidation-phenylhydrazine blockade and a thiocarbohydrazide-silver protein sequence followed by a physical development procedure. From the results obtained by the present experimental and control studies in tissue sections from a series of rat and mouse organs, such as stomach, duodenum, colon, liver, sublingual gland, lung, and kidney, the specificity and sensitivity of the method were sufficient. In the tissues tested, sialic acids were visualized as distinct brownish and blackish reaction products. Comparisons of the new method with the periodic acid-phenylhydrazine-Schiff (PA-P-S) or selective periodate oxidation-Schiff (PA*-S) method employed hitherto have confirmed that the new method reported here is higher in efficiency and visibility of reaction products than the latter two methods.

Animals↗

PubMed1995

Carbohydrate cytochemistry of the endothelium lining the splenic blood vessels in the rat.

In the endothelial cells lining the rat splenic blood vessels, neutral carbohydrates were studied by means of combined periodic acid-thiocarbohydrazide-silver protein (PA-TCH-SP) and alpha-amylase digestion methods. In the endothelial cells lining the central and follicular arteries of the spleen, the neutral glycoconjugate-containing surface coat of the luminal plasma membrane and related pinocytotic invaginations and vesicles in the apical cytoplasm were strikingly distinguished, as compared with those in the cells lining the splenic sinuses. In contrast, cytoplasmic glycogen particles in the sinus endothelial cells were apparently larger in amount than those in the arteriolar endothelial cells. Such cytochemical variations of neutral carbohydrates with the arteriolar and venous vessels of the rat spleen were discussed with special reference to varying cytophysiological functions of the endothelial cells with the different segments of the splenic blood vessels.

Animals↗

PubMed1994

Histochemical analysis of glycoproteins in the unicellar glands in the epidermis of an Indian freshwater fish Mastacembelus pancalus (Hamilton).

The unicellular glands in the epidermis of the Indian freshwater fish Mastacembelus pancalus consist of three types of mucous cells and sacciform cells. The histochemical properties of their secretory glycoproteins have been analysed by means of a battery of histochemical methods. These included methods for the identification and simultaneous visualization of oxidizable vicinal diols, O-acyl sugars, O-sulphate esters and sialic acid residues with or without side-chain O-acyl variants. Four general classes of glycoproteins (GPs) were identified. These included (i) GPs with O-sulphate esters and oxidizable vicinal diols, (ii) GPs with oxidizable vicinal diols and sialic acid residues with or without O-acyl substitution at C7, (iii) GPs mainly with O-sulphate esters, low moieties of GPs with oxidizable vicinal diols, O-acyl sugars and sialic acid residues with side-chain O-acyl variant predominantly at C8 (or which are di- or tri-substituted) or C9 and in traces of sialic acid residues without O-acyl substitution or with O-acyl substitution at C7, and (iv) GPs with traces of oxidizable vicinal diols, O-acyl sugars and sialic acid residues with O-acyl substitution at C8 (or which are di- or tri-substituted) or C9. The physiological significances of these GP classes and their release on the surface of the epidermis are discussed with special reference to their role in lubrication, protection and inhibition of the invasion and proliferation of pathogenic microorganisms in the epidermis, as adapted to the peculiar mode of life of the fish.

Animals↗

PubMed1994

Dual staining methods for carbohydrates using lectin-gold silver techniques.

Three dual staining methods were established for the histochemical detection of saccharide residues and acidic groupings of carbohydrates in light microscopy. The first method consisted of combined lectin-gold silver (LT-G-S) and alcian blue (AB) pH 1.0 techniques, whereas the second staining technique was composed of LT-G-S and AB pH 2.5 procedures. These two techniques were found to color saccharide residues and acidic groupings of carbohydrates in black and blue shades respectively, which exhibited a high contrast between the both. The third methods, LT1-G-S-LT2-PO-DAB techniques, yielded reaction products of blackish and yellowish brown shades, which represented the localizations of two different saccharide residues in one and the same section. According to the results of the experimental and control procedures, the present three dual staining methods are believed to be reliable, reproducible and unusually useful for light microscopic histochemical studies on acidic and non-acidic carbohydrates.

Animals↗