151
|
Fujita J, Kobari M, Takizawa K, Nakayama N. [A case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism]. Rinsho Shinkeigaku 2000; 40:611-3. [PMID: 11086403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
We report a case of HTLV-1 associated myelopathy (HAM) with pseudopseudohypoparathyroidism (PPHP). A 57-year-old woman, without a history of blood transfusion, was admitted with numbness and pain in her legs. Pain sensation in both legs was reduced and tendon reflexes were exaggerated. She exhibited spastic gait. The diagnosis of HAM was made because of positive antibody for HTLV-1 in blood and CSF. She also had features of Albright syndrome (short stature, round face, and short fourth metatarsals) without abnormal calcium and phosphorus metabolism, leading to the diagnosis of PPHP. Brain CT revealed bilateral calcification of the basal ganglia. Although HAM rarely accompanies pseudohypoparathyroidism (PHP), there are few reported cases of HAM associated with PPHP. The exact mechanism of HAM is not known, but it is thought to involve an immune-related process. Since PHP is considered to induce a state of mild immunosuppression through reduction of 1,25-dihydroxyvitamin D3, it is possible that susceptibility to HAM could be augmented in the presence of PHP. If PPHP should be an incomplete form of PHP, a similar mechanism may be involved in the association of PPHP and HAM.
Collapse
|
152
|
Harada T, Harada C, Nakayama N, Okuyama S, Yoshida K, Kohsaka S, Matsuda H, Wada K. Modification of glial-neuronal cell interactions prevents photoreceptor apoptosis during light-induced retinal degeneration. Neuron 2000; 26:533-41. [PMID: 10839371 DOI: 10.1016/s0896-6273(00)81185-x] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Prolonged or high-intensity exposure to visible light leads to photoreceptor cell death. In this study, we demonstrate a novel pathway of light-induced photoreceptor apoptosis involving the low-affinity neurotrophin receptor p75 (p75NTR). Retinal degeneration upregulated both p75NTR and the high-affinity neurotrophin receptor TrkC in different parts of Müller glial cells. Exogenous neurotrophin-3 (NT-3) increased, but nerve growth factor (NGF) decreased basic fibroblast growth factor (bFGF) production in Müller cells, which can directly rescue photoreceptor apoptosis. Blockade of p75NTR prevented bFGF reduction and resulted in both structural and functional photoreceptor survival in vivo. Furthermore, the absence of p75NTR significantly prevented light-induced photoreceptor apoptosis. These observations implicate glial cells in the determination of neural cell survival, and suggest functional glial-neuronal cell interactions as new therapeutic targets for neurodegeneration.
Collapse
|
153
|
Nakayama N, Lee J, Chiu L. Vascular endothelial growth factor synergistically enhances bone morphogenetic protein-4-dependent lymphohematopoietic cell generation from embryonic stem cells in vitro. Blood 2000; 95:2275-83. [PMID: 10733496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
The totipotent mouse embryonic stem (ES) cell is known to differentiate into cells expressing the beta-globin gene when stimulated with bone morphogenetic protein (BMP)-4. Here, we demonstrate that BMP-4 is essential for generating both erythro-myeloid colony-forming cells (CFCs) and lymphoid (B and NK) progenitor cells from ES cells and that vascular endothelial growth factor (VEGF) synergizes with BMP-4. The CD45(+) myelomonocytic progenitors and Ter119(+) erythroid cells began to be detected with 0.5 ng/mL BMP-4, and their levels plateaued at approximately 2 ng/mL. VEGF alone weakly elevated the CD34(+) cell population though no lymphohematopoietic progenitors were induced. However, when combined with BMP-4, 2 to 20 ng/mL VEGF synergistically augmented the BMP-4-dependent generation of erythro-myeloid CFCs and lymphoid progenitors from ES cells, which were enriched in CD34(+) CD31(lo) and CD34(+) CD45(-)cell populations, respectively, in a dose-dependent manner. Furthermore, during the 7 days of in vitro differentiation, BMP-4 was required within the first 4 days, whereas VEGF was functional after the action of BMP-4 (in the last 3 days). Thus, VEGF is a synergistic enhancer for the BMP-4-dependent differentiation processes, and it seems to be achieved by the ordered action of the 2 factors.
Collapse
|
154
|
Hirano T, Mori T, Kido M, Toide K, Ohura M, Fujiki H, Orito K, Yoshida K, Ikezono K, Sumida T, Nakayama N, Yabuuchi Y. Differential properties of the optical-isomers of pranidipine, a 1,4-dihydropyridine calcium channel modulator. Fundam Clin Pharmacol 2000; 13:650-5. [PMID: 10626752 DOI: 10.1111/j.1472-8206.1999.tb00376.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pranidipine is an optically-active 1,4-dihydropyridine (DHP) voltage-dependent L-type calcium channel inhibitor. Certain enantiomeric pairs display opposite effects, i.e., inhibition and activation of the calcium channel while others exhibit the same qualitative actions. We investigated pranidipine, a new DHP, using a paradigm of vascular smooth muscle reactivity. In isolated rat aorta, depolarized with 80 mM KCl, both isomers of pranidipine caused a right-ward shift of the concentration-contraction curves for extracellular Ca2+. The apparent pA2, values of the S-isomer and R-isomer were 10.03 and 8.36, respectively, providing evidence that the calcium channel blocking action of the S-isomer was 50 times more potent than that of the R-isomer. Antihypertensive actions of these two isomers studied in pentobarbital-anaesthetized spontaneously hypertensive rats, revealed that the S-isomer, at doses of 3-30 microg/kg i.v. decreased blood pressure in a dose-dependent manner, while the R-isomer had no effect on blood pressure at those doses. We conclude that the pair of enantiomers of pranidipine qualitatively display the same Ca2+ channel blocking action and that neither isomer exhibits Bay K 8644-like activation. Pranidipine may be useful in studies on the architecture of the DHP receptor 'pocket'.
Collapse
|
155
|
Tsukamoto K, Kurihara T, Nakayama N, Isogai O, Ito S, Komatsu K, Kanmatsuse K. Pressor responses to serotonin injected into the nucleus tractus solitarius of Sprague-Dawley rats and spontaneously hypertensive rats. Clin Exp Hypertens 2000; 22:63-73. [PMID: 10685725 DOI: 10.1081/ceh-100100062] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Previous studies in rats have shown that injection of nanomoles of serotonin (5-hydroxytryptamine; 5HT) into the nucleus tractus solitarius (NTS) acts on 5HT3 receptors to increase arterial pressure (AP). We investigated the effect of 5HT in Sprague-Dawley (SD) rats and in spontaneously hypertensive rats (SHR). Injection of nanomoles of 5HT into the NTS of chloralose-anesthetized SD rats increased AP. This effect was inhibited by prior injection of 5HT3 receptor antagonist ondansetron. The GABA(A) receptor antagonist bicuculline did not inhibit the effect of 5HT. Bilateral injection of 5HT or ondansetron did not affect the baroreflex sensitivity. Bilateral injection of ondansetron did not alter AP. The pressor effect of 5HT was exaggerated in SHR. These results suggest that stimulation of 5HT3 receptors in the NTS increases AP independently of activation of GABAA receptors and the baroreflex sensitivity. Furthermore, this serotonergic system is supersensitive in the NTS of SHR.
Collapse
|
156
|
Kamiusuki T, Monde T, Nakayama N, Yano K, Yoko T, Konakahara T. Interaction between a Solute Molecule and a Fluorocarbon Bonded Layer in Reversed-Phase High-Performance Liquid Chromatography. J Colloid Interface Sci 1999; 220:123-127. [PMID: 10550249 DOI: 10.1006/jcis.1999.6518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glassesand silica-gel packings modified with fluorocarbon and hydrocarbon silylation agents were prepared to investigate the separation mechanism of a fluorocarbon bonded layer in reversed-phase high-performance liquid chromatography (RP-HPLC). On the hydrocarbon layer the contact angles of benzene (Be) and hexafluorobenzene (FB) decreased with increasing carbon chain length of the modifier, and the mobile phase (MP) was independent of the modifier. The fluorocarbon layer gave a larger contact angle for each liquid than the hydrocarbon layer. The retention factor, k, of Be and FB on hydrocarbon packings increased with decreasing contact angle. It was demonstrated that the separation of Be and FB on hydrocarbon packings is caused by solvophobic interaction between solute molecules and the stationary layer. In contrast, k increased with increasing contact angle at the fluorocarbon layer. The retention of Be and FB on fluorocarbon packings may be attributed to the penetration of the solute molecules from the mobile phase into the fluorocarbon stationary layer. Copyright 1999 Academic Press.
Collapse
|
157
|
Hattori T, Yamakawa H, Nakayama N, Kuroda T, Andoh T, Sakai N, Ohno T, Nishimoto Y, Takeuchi S, Shimizu K. Skull metastasis of Ewing's sarcoma--three case reports. Neurol Med Chir (Tokyo) 1999; 39:946-9. [PMID: 10658458 DOI: 10.2176/nmc.39.946] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three cases of skull metastasis of Ewing's sarcoma were treated. The metastatic lesion was located at the midline of the skull above the superior sagittal sinus in all cases. Surgery was performed in two patients with solitary skull lesions involving short segments of the superior sagittal sinus without remarkable systemic metastasis, resulting in good outcome. The third patient had extensive, multiple tumors involving the superior sagittal sinus which could not be excised, and died due to intracranial hypertension. The surgical indication for skull metastasis of Ewing's sarcoma depends on the location and length of the involved superior sagittal sinus, and general condition.
Collapse
|
158
|
Nakayama N, Shinohara R, Mizou T, Arakawa M, Morimoto C. [The role of discharge coordination nurses in a university hospital--changes in the role with timing of the discharge request]. Gan To Kagaku Ryoho 1999; 26 Suppl 2:382-6. [PMID: 10630253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
UNLABELLED We studied the role of discharge assisting nurses who coordinate discharge planning (DP). The requests for DP were ordered at different periods during the admission. The periods were mainly divided into three phases in which the DP was ordered from the wards, which were type 1: just before discharge, type 2: after the decision to discharge, and type 3: between admission and the decision to discharge. We analyzed 8 cases, DP ordered in the type 3 phase provided the most satisfactory outcome for patients' home lives, since the nurse, other medical staff and patients had sufficient time to prepare and provide the needed services. CONCLUSION It was clarified that type 3 provided the best outcome of discharge planning.
Collapse
|
159
|
Nakada T, Nakayama N, Fujii Y, Kwee IL. Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography. Technical note. J Neurosurg 1999; 90:791-5. [PMID: 10193629 DOI: 10.3171/jns.1999.90.4.0791] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.
Collapse
|
160
|
Nakashima T, Nakayama N, Furuichi M, Kokuzawa J, Murakawa T, Sakai N. Arteriovenous malformation in association with moyamoya disease. Neurosurg Focus 1998; 5:e6. [PMID: 17112209 DOI: 10.3171/foc.1998.5.5.9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The authors report two rare cases of arteriovenous malformation (AVM) associated with moyamoya disease. An AVM, supplied by transdural communicating arteries, was located in the right occipital lobe in one patient who presented with ischemia. The second AVM, which was supplied by basal moyamoya vessels, was located in the posterior part of the left frontal lobe in a patient who developed intracerebral hemorrhage that occupied the left basal ganglion.
A review of the literature revealed a total of 12 AVMs in 11 patients with moyamoya disease including our cases. All AVMs were cerebral and two were supplied by normal cerebral arteries, whereas six AVMs were supplied by basal moyamoya vessels at the base of the brain and four AVMs were supplied by external carotid arteries through the transdural communicating arteries. Every AVM drained into deep or cortical cerebral veins. These findings suggest that the hyperangiogenic character of moyamoya disease occasionally induces the development of acquired arteriovenous shunts that mimic AVM.
Collapse
|
161
|
Taguchi Y, Yamamoto M, Yamate T, Lin SC, Mocharla H, DeTogni P, Nakayama N, Boyce BF, Abe E, Manolagas SC. Interleukin-6-type cytokines stimulate mesenchymal progenitor differentiation toward the osteoblastic lineage. PROCEEDINGS OF THE ASSOCIATION OF AMERICAN PHYSICIANS 1998; 110:559-74. [PMID: 9824538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Cytokines that transduce their signals either through glycoprotein 130 (gp130) homodimers or gp 130/leukemia inhibitory factor (LIF) receptor beta heterodimers are potent inducers of osteoclast development in vitro as well as in vivo; and interleukin (IL)-6 has been recognized as an important pathogenic factor in diseases characterized by increased bone remodeling, such as the osteoporosis of sex steroid deficiency. Based on evidence that the same cytokines can also promote committed osteoblast differentiation and stimulate bone formation in vitro and in vivo and that mesenchymal cell differentiation toward the osteoblast lineage may be a prerequisite for osteoclastogenesis, we have investigated whether gp130 activation can affect the differentiation of uncommitted mesenchymal progenitors. Using as our model murine embryonic fibroblasts (EF), we found that IL-6 or IL-11 in combination with their soluble receptors (sIL-6R or sIL-11R) increased dose-dependently the number of alkaline phosphatase (AP)-positive cells in 3-6-day-long cultures. Moreover, EF cells maintained with IL-6/sIL-6R in the presence of ascorbic acid and beta-glycerophosphate expressed osteocalcin messenger RNA (mRNA) by 2 weeks and formed a matrix containing mineralized collagen fibers by 3 weeks. This prodifferentiation effect was specific for the osteoblastic lineage, as we found no evidence for increased differentiation of chondrocytes, adipocytes, or muscle cells. Unlike IL-6/sIL-6R, LIF, oncostatin M (OSM), and ciliary neurotrophic factor (CNTF) did not promote osteoblastic differentiation of EF cells. This pattern of specificity was accounted for by the finding that EF cells express gp130, but not the ligand-binding subunit of the IL-6 receptor (gp80) nor the LIF receptor beta. These observations add credence to the contention that increased production of gp130-utilizing cytokines and their receptors in pathological conditions like sex steroid deficiency is indeed responsible for not only the increased osteoclastogenesis, but also the increased osteoblastogenesis, and thereby for the increased rate of bone remodeling.
Collapse
|
162
|
Fujii Y, Nakayama N, Nakada T. High-resolution T2-reversed magnetic resonance imaging on a high magnetic field system. Technical note. J Neurosurg 1998; 89:492-5. [PMID: 9724132 DOI: 10.3171/jns.1998.89.3.0492] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Because of the high signal-to-noise (S/N) ratio, T2-weighted images obtained using high-field magnetic resonance (MR) imaging systems can be expected to provide high anatomical and contrast resolution. Furthermore, the improved structural and contrast resolution of these high S/N T2-weighted images can be processed for optimum perceptual resolution through the application of gray-scale reversal and expansion of the gray-scale window, known as T2-reversed (T2R) imaging. In this study, the authors investigated high-resolution T2R MR imaging performed on a high-field (3-tesla) system for its clinical utility in detecting various physiological and pathological conditions.
Collapse
|
163
|
Sakurai A, Oka S, Sekine J, Tanaka H, Nagasawa Y, Numao Y, Masuda S, Hasegawa K, Matsunaga T, Kimura Y, Fukuda K, Nakayama N, Matsumoto K, Akabane T, Shiina A, Kobayashi K, Yaginuma T, Hosoda S. Changes of ischemic heart disease in Utsunomiya, Japan, over 10 years: a survey of primary care physicians. JAPANESE CIRCULATION JOURNAL 1998; 62:675-9. [PMID: 9766706 DOI: 10.1253/jcj.62.675] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A total of 502 patients presenting in Utsunomiya city and its suburbs during a 10-year period were studied to determine the clinical features of ischemic heart disease and to identify coronary risk factors. The male/female ratio was 1.21, but the ratio decreased with increasing age. The duration of chest pain showed a continuous spectrum between angina and infarction, with a short duration of chest pain not being useful for excluding the diagnosis of myocardial infarction. Hypertension was more common than hypercholesterolemia in this study, although the prevalence of the latter increased slightly with time, along with the shift towards a modernized occupational pattern. Smoking was a more important risk factor for ischemic heart disease in younger individuals than in the elderly, and diabetes mellitus was highly associated with the development of myocardial infarction. The incidence of radiologically diagnosed cardiac hypertrophy and aortic calcification decreased over time. These changes may have resulted in part from improved blood pressure control and the development of new anti-hypertensive and cholesterol-lowering agents.
Collapse
|
164
|
Nakayama N. [Diffusion tensor analysis with nuclear magnetic resonance in human central nervous system]. [HOKKAIDO IGAKU ZASSHI] THE HOKKAIDO JOURNAL OF MEDICAL SCIENCE 1998; 73:419-34. [PMID: 9828927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Nuclear magnetic resonance has been used to measure the diffusivity of water molecules. In central nervous system, anisotropic diffusion, which is characterized by apparent diffusion tensor Dapp zeta, is thought to be related to neuronal fiber tract orientation. For precise observation of anisotropic diffusion, it is needed to determine the diagonal and off-diagonal elements of Dapp zeta. Once Dapp zeta is estimated from a series of diffusion weighted images, a tissue's orthotropic principal axes and diffusivity of each direction are determined from eigenvalues and eigenvectors of Dapp zeta. There are several methods to represent anisotropic diffusion with Dapp zeta. Examples are diffusion ellipsoids constructed in each voxel depicting both these principal axes and the mean diffusion length in these directions, trace invariant values and its mapping image, largest eigenvalue, and ratio of largest eigenvalue to the other eigenvalue. In this study, the author investigated practical procedure to analyze diffusion tensor Dapp zeta using both of spin-echo and echo-planer diffusion weighted imagings with 3-tesla magnetic resonance machine in human brain. The ellipsoid representation provided particularly useful information about microanatomy including neuronal fiber tract orientation and molecular mobility reflective of microstructure. Furthermore, in the lesion of Wallerian degeneration, the loss of anisotropy of local apparent diffusion was observed. It is suggested that the function of axons can be observed via degree of anisotropy of apparent diffusion. Consequently, diffusion tensor analysis is expected to be a powerful, noninvasive method capable of quantitative and functional evaluation of the central nervous system.
Collapse
|
165
|
Jodo S, Kobayashi S, Nakajima Y, Matsunaga T, Nakayama N, Ogura N, Kayagaki N, Okumura K, Koike T. Elevated serum levels of soluble Fas/APO-1 (CD95) in patients with hepatocellular carcinoma. Clin Exp Immunol 1998; 112:166-71. [PMID: 9649177 PMCID: PMC1904963 DOI: 10.1046/j.1365-2249.1998.00569.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fas (APO-1/CD95)-mediated apoptosis plays an important role in liver cell destruction in viral hepatitis. Using sandwich ELISA, we measured serum levels of soluble Fas (sFas) in patients with hepatocellular carcinoma (HCC) who were positive for hepatitis B surface antigen (HBsAg) or anti-hepatitis C virus (HCV) antibody. sFas levels were significantly higher in HCC patients (median 4.07 ng/ml; range 0.14-29.18 ng/ml) than levels in age-matched healthy donors (0.29 ng/ml; 0-4.90 ng/ ml) (P < 0.0001) and HBsAg or anti-HCV antibody-positive patients with liver cirrhosis (LC) (2.16 ng/ ml; 0.24-8.39 ng/ml) (P = 0.0015). An arbitrary cut-off level of 3.03 ng/ml (mean + 3 s.d. of controls) revealed the positive frequency of sFas in each group: 1.7% in healthy subjects, 25.9% in LC, and 59.0% in HCC (sensitivity 59.0% and specificity 74.1%). All HCC sera tested contained transmembrane-deleted sFas and some contained another sFas lacking the Fas C-terminal. The positive frequency of either sFas (59.0%) or alpha-fetoprotein (AFP) (57.4%) in HCC patients reached 77.0%. HCC patients with multiple tumour foci (7.53 ng/ml; 1.40-29.18 ng/ml) had significantly higher sFas levels than did patients with a solitary tumour (2.70 ng/ml; 0.14-19.0 ng/ml) (P = 0.003). In all of the sFas-positive patients with a solitary tumour, surgical removal of the tumour reduced sFas levels to the negative in the first post-op week. These findings suggest that sFas may be closely linked with HCC and may be a candidate for a clinical parameter for HCC.
Collapse
|
166
|
Harada T, Harada C, Watanabe M, Inoue Y, Sakagawa T, Nakayama N, Sasaki S, Okuyama S, Watase K, Wada K, Tanaka K. Functions of the two glutamate transporters GLAST and GLT-1 in the retina. Proc Natl Acad Sci U S A 1998; 95:4663-6. [PMID: 9539795 PMCID: PMC22547 DOI: 10.1073/pnas.95.8.4663] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the retina, the glutamate transporter GLAST is expressed in Müller cells, whereas the glutamate transporter GLT-1 is found only in cones and various types of bipolar cells. To investigate the functional role of this differential distribution of glutamate transporters, we have analyzed GLAST and GLT-1 mutant mice. In GLAST-deficient mice, the electroretinogram b-wave and oscillatory potentials are reduced and retinal damage after ischemia is exacerbated, whereas GLT-1-deficient mice show almost normal electroretinograms and mild increased retinal damage after ischemia. These results demonstrate that GLAST is required for normal signal transmission between photoreceptors and bipolar cells and that both GLAST and GLT-1 play a neuroprotective role during ischemia in the retina.
Collapse
|
167
|
Nakayama N, Fang I, Elliott G. Natural killer and B-lymphoid potential in CD34+ cells derived from embryonic stem cells differentiated in the presence of vascular endothelial growth factor. Blood 1998; 91:2283-95. [PMID: 9516126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Differentiation of totipotent mouse embryonic stem (ES) cells to various lymphohematopoietic cells is an in vitro model of the hematopoietic cell development during embryogenesis. To understand this process at cellular levels, differentiation intermediates were investigated. ES cells generated progeny expressing CD34, which was significantly enhanced by vascular endothelial growth factor (VEGF). The isolated CD34+ cells were enriched for myeloid colony-forming cells but not significantly for erythroid colony-forming cells. When cultured on OP9 stroma cells in the presence of interleukin-2 and interleukin-7, the CD34+ cells developed two types of B220+ CD34- lymphocytes: CD3- cytotoxic lymphocytes and CD19+ pre-B cells, and such lymphoid potential was highly enriched in the CD34+ population. Interestingly, the cytotoxic cells expressed the natural killer (NK) cell markers, such as NKR-P1, perforin, and granzymes, classified into two types, one of which showed target specificity of NK cells. Thus, ES cells have potential to generate NK-type cytotoxic lymphocytes in vitro in addition to erythro-myeloid cells and pre-B cells, and both myeloid and lymphoid cells seem to be derived from the CD34+ intermediate, on which VEGF may play an important role.
Collapse
|
168
|
Kuriyama H, Yamashita S, Shimomura I, Funahashi T, Ishigami M, Aragane K, Miyaoka K, Nakamura T, Takemura K, Man Z, Toide K, Nakayama N, Fukuda Y, Lin MC, Wetterau JR, Matsuzawa Y. Enhanced expression of hepatic acyl-coenzyme A synthetase and microsomal triglyceride transfer protein messenger RNAs in the obese and hypertriglyceridemic rat with visceral fat accumulation. Hepatology 1998; 27:557-62. [PMID: 9462657 DOI: 10.1002/hep.510270233] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The liver plays a central role in lipoprotein metabolism. In particular, very-low density lipoprotein (VLDL) is assembled in the hepatocytes and secreted into the blood circulation. The VLDL is then catabolized to low-density lipoprotein by lipoprotein lipase and hepatic triglyceride lipase. Obese subjects, especially those with visceral fat accumulation, are frequently associated with hyperlipidemia, non-insulin-dependent diabetes mellitus (NIDDM), and hypertension. The mechanism of hyperlipidemia in visceral fat obesity has not yet been elucidated. Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model of NIDDM, characterized by obesity with visceral fat accumulation, hyperlipidemia, and late-onset insulin resistance. To elucidate the mechanism of hyperlipidemia observed in OLETF rats, we focused on the production of VLDL by the liver and investigated hepatic messenger RNA (mRNA) levels of microsomal triglyceride transfer protein (MTP), acyl-coenzyme A synthetase (ACS), and apolipoprotein B (apo B), which play important roles in VLDL synthesis and secretion. In 6-week-old OLETF rats, in which insulin resistance had not been manifested, visceral fat weight was already higher and portal free fatty acid (FFA) and VLDL-triglyceride levels were elevated compared with the control rats. Hepatic ACS activity and mRNA levels, and MTP mRNA levels were also increased in OLETF rats, whereas apo B mRNA levels were similar; these results suggest that the enhanced expression of both ACS and MTP genes associated with visceral fat accumulation before developing insulin resistance may be involved in the pathogenesis of hyperlipidemia in obese animal models with NIDDM.
Collapse
|
169
|
Toide K, Man ZW, Asahi Y, Sato T, Nakayama N, Noma Y, Oka Y, Shima K. Glucose transporter levels in a male spontaneous non-insulin-dependent diabetes mellitus rat of the Otsuka Long-Evans Tokushima Fatty strain. Diabetes Res Clin Pract 1997; 38:151-60. [PMID: 9483380 DOI: 10.1016/s0168-8227(97)00101-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Otsuka Long-Evans Tokushima Fatty (OLETF) rats are a new strain of spontaneous non-insulin-dependent diabetes mellitus (NIDDM) models. To evaluate the role of glucose transporters (GLUT) in the development of diabetes in this model, we examined the action of insulin on the translocation of GLUT4 and GLUT1 in isolated adipocytes, and the GLUT4 protein levels in muscles. Long-Evans Tokushima Otsuka (LETO) rats were used as a control strain. In adipocytes, the GLUT4 protein levels in OLETF rats at 30 weeks of age (diabetic stage) were considerably lower than those in LETO rats at the same age. At a pre-diabetic stage (7 weeks), there were no significant differences in GLUT4 protein levels in adipocytes between LETO and OLETF rats. However, the degree of GLUT4 translocation in OLETF rats was lower than that in LETO rats at 7 weeks of age. There were no differences in GLUT1 levels in adipocytes between the two strains. In muscles, the decrease in GLUT4 protein was observed in OLETF rats at 30 weeks of age. Whether such a difference is under the influence of hyperglycemia was also examined using rats rendered diabetic by 70% pancreatectomy. OLETF rats aged 7 weeks were subjected to partial pancreatectomy (Px) and sham pancreatectomy (sham). At 4 weeks after surgery, GLUT4 protein levels in adipose tissues and skeletal muscles were determined. GLUT4 decrease was observed for both tissues of hyperglycemic Px rats compared with euglycemic sham. Moreover, we examined the direct effect of glucose on GLUT4 protein using primary cultured adipocytes of OLETF rats at 5 weeks of age. After 7-day culture with normal (5.6 mmol/l) or high (25 mmol/l) concentrations of glucose, the GLUT4 protein levels in adipocytes decreased at 25 mmol/l glucose compared with 5.6 mmol/l glucose. These findings suggest an early defect in the insulin resistance of OLETF rats probably reflects impaired GLUT4 translocation. The GLUT4 decrease, which occurs later in the process appears to be a consequence, rather than a cause of diabetes in OLETF rats.
Collapse
|
170
|
Yamashita S, Kuriyama H, Ishigami M, Aragane K, Shimomura I, Funahashi T, Nakayama N, Wetterau J, Matsuzawa Y. 4.P.246 Contribution of enhanced hepatic acyl-CoA synthetase and microsomal triglyceride transfer protein to the pathogenesis of hyperlipidemia. Atherosclerosis 1997. [DOI: 10.1016/s0021-9150(97)89774-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
171
|
Tokunaga Y, Nakayama N, Ishikawa Y, Nishitai R, Irie A, Kaganoi J, Ohsumi K, Higo T. Surgical risks of acute cholecystitis in elderly. HEPATO-GASTROENTEROLOGY 1997; 44:671-6. [PMID: 9222669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND/AIMS For the elderly patient, an emergency biliary procedure carries a higher risk than an elective operation. Recently introduced advances in ultrasonography and critical care medicine have affected the clinical risks of surgery for acute cholecystitis in the elderly. This study evaluated the clinical risks of open cholecystectomy for the elderly with acute cholecystitis. MATERIALS AND METHODS During a 10 year period (1985-1994), a total of 145 patients were diagnosed with acute cholecystitis and underwent cholecystectomy. According to their age, the patients were divided into 3 groups (Group A < 59 years of age; Group B between 60-69 years of age; Group C > 70 years of age). The characteristics and the surgical risk factors in open cholecystectomy for the elderly with acute cholecystitis were evaluated. RESULTS The rate of acalculous cholecystitis and choledochal stones were significantly (p < 0.05) high in Group C. Septic complication, gangrenous changes, and positive bile culture were also increased parallel to the increase in age. A noteworthy finding was an incidental carcinoma found in a case in group B and in 3 cases in group C. Hospital stay was significantly longer in Group C than in the other groups due to pre-operative complications and post-operative morbidity. CONCLUSION With respect to increase in elderly patients with acute cholecystitis who present more frequent gangrenous changes and carcinomatous changes as well as high rate of septic complication, successful treatment of these patients is increased when early surgery can be performed on the basis of accurate and prompt diagnosis using imaging modalities and meticulous peri-operative management.
Collapse
|
172
|
Nakakoshi T, Kajiyama M, Fujita N, Nakayama N, Takeichi N, Miyasaka K. Copper concentration in hyperintense hepatocellular carcinomas of Long-Evans cinnamon rats on T1-weighted images. Magn Reson Imaging 1997; 15:689-91. [PMID: 9285808 DOI: 10.1016/s0730-725x(97)00018-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Long-Evans Cinnamon (LEC) rat has abnormal intrahepatic copper accumulation and spontaneously develops hepatocellular carcinomas following hereditary hepatitis. The hepatocellular carcinomas are very similar to human well-differentiated hepatocellular carcinoma in histopathological features and on MR images. Copper is believed to be one of the causes of hyperintensity of hepatocellular carcinomas compared to surrounding non-cancerous tissues on T1-weighted MR image. Eight LEC rats were studied by MR imaging. We measured copper concentrations from the hepatocellular carcinomas and surrounding non-cancerous liver tissues. Signal intensity of hepatocellular carcinomas without cystic areas was iso- to slightly hyperintense relative to surrounding non-cancerous tissues on T1-weighted images. Histopathologically, most of the tumors resembled human highly or well-differentiated hepatocellular carcinomas. Copper concentrations of the hepatocellular carcinomas were lower than the surrounding non-cancerous liver tissues. Copper may not be the cause of increased signal intensity typically observed on T1-weighted images of hepatocellular carcinomas.
Collapse
|
173
|
Monde T, Nakayama N, Yano K, Yoko T, Konakahara T. Adsorption Characteristics of Silica Gels Treated with Fluorinated Silylation Agents. J Colloid Interface Sci 1997; 185:111-8. [PMID: 9056313 DOI: 10.1006/jcis.1996.4546] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Branched-chain polyfluorosilane (monochlorodimethyl[4,4-bis(trifluoromethyl)-5,5,6,6,7,7,7-heptafluoroheptyl)-bonded silica gels were prepared. The surface properties of the silica gels modified with various organic silanes were evaluated by the adsorption density of polar and nonpolar gases calculated from adsorption isotherms of nitrogen, carbon dioxide, and normal butane gases. The polyfluorocarbon-bonded silica gel surface was found to be both hydrophobic and oleophobic in nature, whereas the hydrocarbon-bonded silica gel surface was characterized only as hydrophobic. The trifunctional fluorinated silane provides the silica gel surface with a more hydrophilic nature than the monofunctional silane because of the formation of a denser polymeric coating layer with a larger number of silanols.
Collapse
|
174
|
Nakayama N, Kashiwazaki H, Kobayashi N, Hamada JI, Ogiso Y, Itakura Y, Matsumoto K, Nakamura T, Koike T, Kuzumaki N, Takeichi N. Hepatocyte growth factor and c-met expression in Long-Evans Cinnamon rats with spontaneous hepatitis and hepatoma. Hepatology 1996; 24:596-602. [PMID: 8781331 DOI: 10.1002/hep.510240323] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The Long-Evans Cinnamon (LEC) rat is characterized by the spontaneous onset of acute and chronic hepatitis, followed by occurrence of liver cancer, and is thus able to provide a unique experimental model for human genetical liver disease, Wilson's disease. Hepatocyte growth factor (HGF) is a potent hepatotrophic factor in liver regeneration, and its expression is up-regulated in response to liver injuries. We found that the plasma HGF level in LEC rats rose markedly during the fulminant hepatitis phase, fell during the phase of chronic/cholangiofibrosis, and fluctuated during the hepatoma phase. Immunohistological staining of the liver revealed that the number of HGF-positive cells increased remarkably during the fulminant hepatitis phase, and that many of these cells were localized at the portal triads. Fewer HGF-positive cells were observed during the phase of chronic hepatitis. The surface of the hepatocellular carcinoma (HCC) cells and the cytoplasm of the nonepithelial cells in cancerous liver tissues were HGF-positive. The HGF-messenger RNA (mRNA) level in the liver rose in the fulminant hepatitis phase, fell in the chronic hepatitis phase, and was intermediate or high during the hepatoma phase. The expression of c-met mRNA was strong in the tissues of LEC rats with fulminant hepatitis and, especially, in the cholangiofibrosis tissues. c-met mRNA was also detected in HCCs. These results suggest that the HGF-c-met system may play an important role in the regeneration of hepatocytes as well as in the development of HCC in paracrine or autocrine mechanisms.
Collapse
|
175
|
Nakashima K, Yamashita T, Kashiwagi S, Nakayama N, Kitahara T, Ito H. The effect of sodium bicarbonate on CBF and intracellular pH in man: stable Xe-CT and 31P-MRS. ACTA NEUROLOGICA SCANDINAVICA. SUPPLEMENTUM 1996; 166:96-8. [PMID: 8686453 DOI: 10.1111/j.1600-0404.1996.tb00561.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of sodium bicarbonate on cerebral blood flow (CBF) and intracellular pH were studied in five normal volunteers. CBF and intracellular pH were measured by stable xenon computed tomography and phosphorus-31 magnetic resonance spectroscopy (31P-MRS) respectively. Each patient received 7% sodium bicarbonate (3.5 ml/kg body weight) infused intravenously for 15 minutes. Before and after this injection, CBF intracellular pH and physiological parameters were measured. CBF and PaCO2 were significantly increased. On the other hand, hematocrit and intracellular pH were decreased. These result suggests that three factors are thought to contribute to increase CBF during administration of sodium bicarbonate in humans: 1) arterial dilatation in response to carbon dioxide 2) an decrease of hematocrit 3) intracellular acidosis.
Collapse
|