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I Nakanishi

Publications and source records attributed to I Nakanishi.

At least 19 recordsLinked to original sources
PubMed2003

Sporadic Creutzfeldt-Jakob disease with MM1-type prion protein and plaques.

The authors report a 75-year-old woman with atypical sporadic Creutzfeldt-Jakob disease (CJD) characterized by MM1-type prion protein (PrP) (methionine homozygosity at codon 129 in the PrP gene and type-1 protease-resistant PrP) and PrP plaques. This patient is the first case of sporadic CJD with plaque-forming MM1-type PrP, suggesting either a shared prion strain with the plaque-forming subset of dural graft-associated CJD or shared host genetic factors that are unrelated to the PrP genotype.

Aged↗
PubMed2002

Clinicopathological study of involvement of granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor in non-lymphohematopoietic malignant tumors accompanied by leukocytosis.

Involvement of granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF) in non-lymphohematopoietic malignant tumors accompanied by leukocytosis was clinicopathologically investigated. Among 1,778 autopsy cases in the last 20 years, 485 lesions of 439 cases with non-lymphohematopoietic malignant tumors accompanied by leukocytosis with a white blood cell count of 10,000/mm3 or greater during the course were immunohistologically examined for G-CSF and GM-CSF. Three (0.7%) and two cases (0.5%) were G-CSF- and GM-CSF-positive, respectively. GM-CSF mRNA was confirmed by using non-fixed cryopreserved tumor tissues in one case positive for GM-CSF. G-CSF-positive cases were large cell carcinoma of the lung, adenocarcinoma of the colon, and adenocarcinoma of the stomach, and GM-CSF-positive cases were spindle cell carcinoma of the lung and malignant thymoma. In the case with stomach carcinoma, the primary lesion showing moderately differentiated adenocarcinoma was negative, but the lung metastatic lesion showing less differentiated adenocarcinoma was G-CSF-positive. The survival period was six months or less in four out of five positive cases. The highest white blood cell count in five CSF-positive cases was markedly elevated: 29,400-103,500/mm3 (mean: 59,700/mm3). In four cases, excluding one case which may have been markedly affected by chemotherapy, the bone marrow showed hyperplasia, and the number of the granulocyte series cells significantly increased. There were three cases (0.7%) negative for both G-CSF and GM-CSF, although they showed marked leukocytosis (60,000/mm3 or higher) which were higher than the mean count of CSF-positive cases and was not observed in autopsy cases with non-tumorous diseases. Other stimulating factors may be involved in the development of leukocytosis in such cases.

Bone Marrow↗
PubMed2001

Collagen remodeling and cardiac dysfunction in patients with hypertrophic cardiomyopathy: the significance of type III and VI collagens.

BACKGROUND: The relationship between the extent of myocardial interstitial fibrosis, the percentage of each type of collagen, and cardiac function in patients with hypertrophic cardiomyopathy (HC) has not been established. HYPOTHESIS: The study aimed to establish that increases in some types of collagen may correlate with cardiac dysfunction. METHODS: Mallory-Azan staining and immunohistochemical staining by the avidin-biotin-complex (ABC) method using anticollagen antibodies were performed on the myocardial biopsy specimens in 35 patients with HC, and the percentage and type of collagen present was determined. Left ventricular (LV) function was evaluated by cardiac catheterization and ventriculography. RESULTS: The percentage of myocardial interstitial fibrosis correlated highly with indices of LV diastolic and systolic function. The amount of type III collagen correlated significantly with the peak negative dp/dt, the rapid filling volume/stroke volume, and the ejection fraction (EF). Significant correlations also were noted between the amount of type VI collagen and peak negative dp/dt, peak positive dp/dt, and EF. Type I collagen did not correlate with any of the LV function indices, and type IV collagen correlated only with peak ejection rate. Type V collagen did not accumulate substantially in the myocardial interstitium. CONCLUSIONS: The progression of myocardial interstitial fibrosis in the HC heart adversely impacts both the diastolic and systolic function of the LV. Increases in the percentage of type III and VI collagen correlate with cardiac dysfunction.

Adolescent↗
PubMed2001

Tumour necrosis factor-alpha provokes upregulation of alpha2beta1 and alpha5beta1 integrins, and cell migration in OST osteosarcoma cells.

OST cells enhance the induction of matrix metalloproteinase (MMP)-9 by tumour necrosis factor (TNF)-alpha and the corresponding metastasis to lungs in vivo (Kawashima et al., 1994). We focused on the adhesive and migratory properties of OST cells, and investigated the expression of integrins in OST cells stimulated by TNFalpha in vitro. OST cells potentiated not only adhesion to the extracellular matrix (ECM) but also the migration on ECM. On competitive reverse transcription-polymerase chain reaction (RT-PCR) analyses, the amounts of alpha2 (4.9-fold), alpha5 (1.2-fold) and alpha(v) (4.9-fold) were upregulated by TNFalpha at the transcriptional level. Alpha-5 showed a slight increase by flow cytometry; however, alpha2 and alphav integrins remained unchanged at the protein level. Immunofluorescence study disclosed integrins of alpha2beta1 and alpha5beta1 were much clustered at cell processes by TNFalpha stimulation, probably related to increased cell adhesion and migration. Therefore, the upregulation of alpha2beta1 and alpha5beta1 integrins seems to contribute to tumour invasion and metastatic potential.

Cell Adhesion↗
PubMed2001

Effect of vagal afferent conditioning on trigeminal motor neuron activity associated with tooth-pulp-evoked jaw-opening reflex.

To clarify the vagal afferent modifying effect on the neurons constituting the nociceptive jaw-opening reflex (JOR), we conducted extracellular recording of trigeminal motor nucleus (TMN) neuron activity in pentobarbital-anesthetized rats. Of 12 TMN neuron responses evoked by tooth pulp (TP) stimulation, 10 were suppressed by vagal afferent conditioning (83%). The mean time of the suppressive effect on the TMN neurons paralleled that found with the digastric electromyogram (dEMG), and maximal inhibition of both TMN neuronal spikes and the dEMG amplitude were observed at a 50-ms conditioning-test interval. The ratio of inhibition was approximately 38%. Seven of 12 units were activated antidromically by digastric muscle stimulation (1-3 mA, 0.1 ms, 2 Hz) and fulfilled the criteria for antidromic activation. Vagal afferent conditioning stimulation had no effect on the antidromic TMN neuronal responses to digastric muscle stimulation. These results suggest that suppression of the TP-evoked JOR in response to vagal afferent stimulation in rats is the result of an inhibitory effect on the sensory neurons rather than on the motor neurons.

Journal Article↗
PubMed2000

Structure of porcine pancreatic elastase complexed with FR901277, a novel macrocyclic inhibitor of elastases, at 1.6 A resolution.

Human leukocyte elastase (HLE) is a serine protease that contributes to tissue destruction in various disease states-for example, in emphysema. FR901277 is a natural product isolated from the culture filtrate of Streptomyces resistomicificus and is a potent inhibitor of both HLE and porcine pancreatic elastase (PPE). FR901277 consists of four normal amino acids and three unusual amino acids, and is a unique bicyclic peptide compound. The crystal structure of PPE complexed with FR901277 has been determined at 1.6 A resolution. The Ogamma atom of Ser-195 in PPE did not form a covalent bond with FR901277, but formed a hydrogen bond with the Nvarepsilon atom of His-57. On the other hand, the portion from L-Orn(1) through dehydroxyThr(3) in FR901277 formed an antiparallel beta-sheet structure with the backbone of the active site in PPE. The S4 through S2' binding subsites in PPE were all occupied by the hydrophobic side chains of the inhibitor molecule. Especially, the ethylidene moiety of FR901277 occupied the S1 specific pocket, indicating a CH/pi interaction. In addition, the isopropyl side chain of L-Val(7) was located at the enzyme surface between the S2 and S1' pockets with several van der Waals contacts. However, the amino acid (4) residue was not involved in a significant interaction with PPE. Comparison of inhibitor structures in different environments showed that FR901277 has a highly rigid bicyclic framework; however, it can slightly change its conformation according to the circumstances. The binding mode of FR901277 at the active site of PPE was directly applicable to that in HLE, after consideration of induced fit. The structure of the PPE-FR901277 complex provided much information regarding potential sites for modification of the physicochemical properties of FR901277.

Amides↗
PubMed2000

Urine levels of CD46 (membrane cofactor protein) are increased in patients with glomerular diseases.

Soluble membrane cofactor protein (MCP, CD46) has not been detected by conventional ELISA in human urine. Here, we established a highly sensitive assay method for determination of urinary MCP (uMCP) using monoclonal antibody-coated paramagnetic beads. This method enabled us to detect less than 0.05 ng/ml of purified membrane and recombinant soluble MCP, a sensitivity 10-fold higher than that of conventional ELISA. In normal subjects, the levels of uMCP were <0. 05 ng/ml. The levels of uMCP were elevated in patients with IgA nephropathy and more prominently in patients with rapidly progressive glomerulonephritis. The levels of uMCP were correlated significantly with those of serum MCP (sMCP) and N-acetyl-beta-glucosaminidase and nonsignificantly with those of beta(2)-microglobulin, total urine protein, or serum creatinine. The properties of uMCP were inconsistent with those of the reported sMCP, since uMCP showed three bands on SDS-PAGE/immunoblotting with molecular mass profiles different from those of sMCP. uMCP exhibited factor I cofactor activity for cleavage of C3b comparable to that of sMCP. The origin of uMCP, however, remains to be determined. These results, taken together with the parameter correlation profiles, suggested that uMCP is secreted or produced secondary to tubular or glomerular damage. The physiological role and clinical significance of uMCP are now within the scope of our investigation by establishment of this assay.

Acetylglucosaminidase↗
PubMed2000

Characterization of bacterial orofacial infections using a new murine model.

We devised a new murine orofacial infection model using bacteria from odontogenic infection origins and characterized the experimental infections. In this model, bacteria were injected into the submandible of mice. Streptococcus constellatus and Peptostreptococcus micros produced a single abscess at the injection site and their abscess-forming and lethal abilities were low: the median abscess-forming dose (AF(50)) of S. constellatus and P. micros were 10(8.5-10.7)and 10(10.2-10.6)cfu/mouse, and their median lethal dose (LD(50)) were >11 and 10(10.6-11)cfu/mouse, respectively. Prevotella oralis and Fusobacterium nucleatum produced multiple abscesses and their abscess-forming and lethal abilities were strong: AF(50)of P. oralis and F. nucleatum were 10(6.0-6.4)and 10(7. 0-8.7)cfu/mouse, and their LD(50)were 10(7.0-7.7)and 10(8.3-9. 9)cfu/mouse, respectively. LD(50)of P. intermedia and P. gingivalis were 10(9.4->11)and 10(8.9-9.1)cfu/mouse, respectively. Prevotella intermedia and Porphyromonas gingivalis generated a necrotizing lesion, which progressed rapidly. We conclude that this murine model could reflect human orofacial odontogenic infections and is useful to investigate the pathogenicity of causative bacteria of such infections.

Abscess↗
PubMed2000

Modulation of collagen synthesis by tumor necrosis factor alpha in cultured vascular smooth muscle cells.

Collagen synthesis in vascular smooth muscle cells (SMCs) after exposure to tumor necrosis factor alpha (TNF-alpha) was investigated using a culture system. The synthesis of collagenase-digestible proteins (CDP) and noncollagenous proteins (NCP) was evaluated by the [3H]proline incorporation. It was shown that TNF-alpha markedly suppresses the incorporation of [3H]proline into both CDP and NCP in confluent cultures of SMCs but not in sparse cultures of the cells. Such a marked suppression by TNF-alpha was not observed in confluent bovine aortic endothelial cells and human fibroblastic IMR-90 cells. In confluent SMCs, the synthesis of CDP was more strongly inhibited by TNF-alpha than that of NCP. When the CDP synthesis was stimulated by transforming growth factor beta, TNF-alpha suppressed the stimulation in both confluent and sparse SMCs. Human SMCs synthesized types I, III, IV and V collagens; TNF-alpha markedly decreased the relative proportion of types IV and V. It was therefore suggested that TNF-alpha modulates the collagen synthesis by SMCs depending on their cell density and modifies the formation of atherosclerotic lesions.

Animals↗
PubMed2000

Early treatment with corticosteroids ameliorates proteinuria, proliferative lesions, and mesangial phenotypic modulation in adult diffuse proliferative IgA nephropathy.

Diffuse proliferative immunoglobulin A (IgA) nephropathy has the potential risk for end-stage renal disease. However, treatment of IgA nephropathy has not been well established. To determine whether early treatment with corticosteroids ameliorates the proliferative lesions of diffuse proliferative IgA nephropathy, we conducted a prospective, randomized, controlled trial. Inclusion criteria were as follows: duration of abnormal urinalysis results less than 36 months, proteinuria less than 1.5 g/d of protein, serum creatinine level less than 1.5 mg/dL, and mesangial cell proliferation or matrix accumulation involving more than 50% of glomeruli. Twenty-one patients were randomly assigned to two groups: the corticosteroid group and the antiplatelet group. After 1 year of treatment, repeated renal biopsy was performed in 19 patients. We evaluated glomerular filtration rate, blood pressure, proteinuria, and histological parameters, including light microscopic findings and staining of alpha-smooth muscle actin (alphaSMA), as a marker of myofibroblast-like cells and fibronectin EDA (EDA-FN) as an indicator of renal fibrosis. After 1 year of treatment, proteinuria significantly decreased in the corticosteroid group. Histological findings, such as mesangial cell proliferation, mesangial matrix accumulation, and cellular crescents, showed significant improvement in the corticosteroid group but not in the antiplatelet group. Expression of alphaSMA in glomeruli significantly decreased in the corticosteroid group but not in the antiplatelet group. EDA-FN did not change in either group. We conclude that early treatment with corticosteroids for adult diffuse proliferative IgA nephropathy is effective in reducing renal injury.

Adult↗
PubMed2000

1H-NMR determination of the solution structure and absolute configuration of FR134043, a novel inhibitor of human leukocyte elastase.

FR134043 is a semisynthetic disulfonated derivative of the natural product FR901277, is isolated from the culture filtrate of Streptomyces resistomicificus and has potent inhibitory activity against human leukocyte elastase. Although the chemical structure of FR134043 was determined to be a unique bicyclic peptide-like compound consisting of seven amino acids by using several spectroscopic analytical methods, the chiralities of three centers were unknown. A simple simulated annealing protocol to determine the structure was applied to the eight possible stereoisomers, and the one that best satisfied the NOE distance constraints was determined to be the true stereoconfiguration of FR134043. The solution structure showed that all Calpha atoms existed in the L configuration and six of the seven side chains were located towards the outside of the bicyclic framework, even though most of them are highly hydrophobic moieties. The simulated annealing calculation described here is a frequently used method for the determination of the solution structure of peptides or small proteins. We show here that it is also applicable to the determination of the absolute configuration of macrocyclic compounds produced from natural sources.

Heterocyclic Compounds↗
PubMed2000

A case of atypical granular cell tumor of the neurohypophysis.

A case of granular cell tumor (GCT) arising in the neurohypophysis of a 63-year-old woman is reported. The tumor consisted of ovoid, polygonal or spindle-shaped cells in a sheet-like or fascicular arrangement. Its abundant cytoplasm contained granules positive for diastase-resistant periodic acid-Schiff reaction. Ultrastructurally, the tumor cells contained numerous polymorphic lysosomes of various densities. Immunohistochemically, the tumor cells were positive for S-100 protein, glial fibrillary acidic protein and Leu7, suggesting that the tumor originated from pituicytes that were thought to be modified astrocytes in the neurohypophysis and its stalk. The granular cells showed nuclear atypia, pleomorphism and increased mitotic activity. Therefore, the present tumor was considered as a histologically atypical GCT. Interestingly, proliferating cell nuclear antigen, Ki-67 and p53 were stained in a few tumor cells of this case. These findings indicate that the present tumor had a malignant potential.

Biomarkers, Tumor↗
PubMed2000

Microvascular angiogenesis and apoptosis in the survival of free fat grafts.

OBJECTIVES/HYPOTHESIS: Autologous fat is an ideal material for augmentation in plastic surgery because of its minimal tissue reaction and easy availability, but its long-term graft survival is somewhat unpredictable. This study was conducted to determine how fat grafts get their vascular supply from the recipient bed and why they keep reducing in volume and weight. STUDY DESIGN: Experimental study using animal models. METHODS: The expression of vascular endothelial growth factor (VEGF) in grafted fat tissue was examined by using immunohistochemical staining, and apoptotic cell death in the grafted fat was studied by using terminal deoxynucleotidyl transferase (TdT)-mediated deoxy-uridine triphosphate (dUTP)-biotin nick end-labeling method. Twenty-five Wistar rats were used as models of free fat grafts. Fat tissue taken from inguinal fat pads was grafted to the back skin with an 18-gauge needle injection. RESULTS: The weight of the injected fat was significantly reduced on the 180th day compared with the original weight (32% +/- 10%). VEGF+ cells were observed in fibrous connective tissue of the grafts on days 7 and 30 but not after day 90. Apoptotic cells were also observed on days 7 and 30. CONCLUSIONS: Angiogenic factors including VEGF started to revascularize the graft around day 7, and the extent of the vasculature was not reduced after the revascularization. In addition to necrosis in the graft's early stages, apoptosis induced by many factors in the graft's environment is also, at least in part, a cause of long-term volume reduction of the fat graft. Thus clinical application of angiogenic factors such as VEGF to fat grafts and control of apoptosis may contribute to improvements in fat-grafting techniques.

Adipose Tissue↗
PubMed2000

Hydroxylation of nitrated naphthalenes with KO2/crown ether.

Superoxide radical anion (O2*-), generated by KO2/crown ether, is effective for hydroxylation of nitronaphthalenes. When mono- and di-nitronaphthalenes are treated with KO2/crown ehter, hydroxylation results at the electron-deficient site caused by the electron withdrawing effect of the substituted nitro group. Kinetic experiments suggest that the hydroxylation proceeds by two different mechanisms dependent on the first one-electron reduction potential of nitronaphthalenes.

Ethers, Cyclic↗
PubMed2000

[Reactive species responsible for biological actions of photoexcited fullerenes].

Fullerene (C60, C70, etc.) is an effective photosensitizer and its utilization as a pharmacophore for photo-chemotherapy of tumors has received considerable attention. We developed a method to solubilize fullerenes into water with polyvinylpyrrolidone (PVP) as a detergent. By using thus prepared aqueous fullerene solutions, we have clarified a series of biological activities of fullerene under photoirradiation which include DNA-cleavage, hemolysis, mutagenicity, cancer-initiation, and cell-toxicity. A newly synthesized C60 derivative with an acridine moiety as a DNA-chelating function showed much more effective DNA-cleaving activity in the presence of NADH. Visible-light irradiation of PVP-solubilized C60 in water in the presence of NADH as a reductant and molecular oxygen resulted in the formation of O2.-, which was detected by the EPR spin-trapping method. Formation of O2.- was also evidenced by the direct observation of a characteristic signal of O2.- by the use of a low-temperature EPR technique at 77 K. On the other hand, no formation of 1O2 was observed by the use of TEMP as a 1O2 trapping agent. No near-IR luminescence of 1O2 was also observed in the aqueous C60/PVP/O2 system. These results suggest that photoinduced bioactivities of the PVP-solubilized fullerene are caused not by 1O2, but by reduced oxygen species (O2.-, .OH) which are generated by the electron-transfer reaction of C60.- with molecular oxygen.

Animals↗
PubMed2000

Immunohistochemical and in situ hybridization studies of choline acetyltransferase in large motor neurons of the human spinal cord.

The localization of choline acetyltransferase (ChAT) protein and mRNA was investigated in large motor neurons of the lumbar spinal cord of 10 autopsied individuals without neurological diseases, by immunohistochemistry and in situ hybridization. In the immunohistochemistry using 20 serial tissue sections with a total thickness of 80 microm, about approximately 58-85% (average 67%) of the large motor neurons (30 microm and more in somal minimal diameter) in the ventral horn were stained with the anti-human ChAT antibody. In the positive neurons, most immunoreactive products were observed focally in the perikarya. Occasionally, the perikarya of some neurons were stained diffusely. In situ hybridization with a single 4 microm-thick tissue section showed that almost all large motor neurons had positive signals (approximately 93-100%, average 98%), which were distributed diffusely in the perikarya. The positivity rate in the in situ hybridization was higher than that in the immunohistochemistry for all 10 cases. These results indicate that ChAT mRNA is transcribed in almost all large motor neurons in the ventral horn of the human spinal cord, but ChAT protein cannot always be detected in the cytoplasm by immunohistochemistry.

Choline O-Acetyltransferase↗
PubMed2000

The distribution of cholinergic neurons in the human central nervous system.

Choline acetyltransferase (ChAT), the enzyme responsible for the biosynthesis of acetylcholine, is presently the most specific marker for identifying cholinergic neurons in the central and peripheral nervous systems. The present article reviews immunohistochemical and in situ hybridization studies on the distribution of neurons expressing ChAT in the human central nervous system. Neurons with both immunoreactivity and in situ hybridization signals of ChAT are observed in the basal forebrain (diagonal band of Broca and nucleus basalis of Meynert), striatum (caudate nucleus, putamen and nucleus accumbens), cerebral cortex, mesopontine tegmental nuclei (pedunculopontine tegmental nucleus, laterodorsal tegmental nucleus and parabigeminal nucleus), cranial motor nuclei and spinal motor neurons. The cerebral cortex displays regional and laminal differences in the distribution of neurons with ChAT. The medial septal nucleus and medial habenular nucleus contain immunoreactive neurons for ChAT, which are devoid of ChAT mRNA signals. This is probably because there is a small number of cholinergic neurons with a low level of ChAT gene expression in these nuclei of human. Possible connections and speculated functions of these neurons are briefly summarized.

Animals↗