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1.
Rev Sci Instrum ; 93(2): 023301, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-35232164

ABSTRACT

In high-frequency pulsed magnets, such as kickers in particle accelerators, it is essential to reduce eddy currents that could be induced in the magnet core during excitation not to distort and attenuate the magnetic field pulse. A novel iron lamination scheme with additional interlaminar insulation is proposed for the magnet core of such pulsed magnets. A laminated steel sheet core is formed by alternately stacking thin steel and insulation sheets. For application to matched kicker magnets for accelerators, test magnets with the new and conventional iron lamination were designed, assembled, and extensively evaluated. The pulsed magnetic field waveforms of two test magnets with the new lamination successfully matched to below 0.1% over the entire pulse duration, which was significantly better than those with the conventional lamination. Among the applications of the developed high-frequency pulsed magnets, beam injection kickers for the coming next generation light sources and future colliders, where suppression of the transient stored-beam oscillation during beam injection is crucial, are considered to be promising.

2.
Rev Sci Instrum ; 90(5): 054703, 2019 May.
Article in English | MEDLINE | ID: mdl-31153263

ABSTRACT

The high-accuracy alignment of magnets is a key issue in the development of next-generation light-source rings. To obtain adequate dynamic apertures, the magnets must be aligned to an accuracy of 10 µm or better. Recently, a new technique that utilizes a vibrating wire has attracted attention for this purpose as it can directly determine with high resolution the magnetic centers in a series of multipole magnets on a straight section between bending magnets. In conventional vibrating-wire alignment techniques, wire sag, which causes alignment errors, is determined from the theoretical catenary curve. By contrast, in the present study, we have measured the sag profiles of various wires in the longitudinal direction to micrometer-order accuracy. We concluded that we can reduce deviations of the actual wire sag from the theoretical curve by choosing a suitable wire. By setting up a test bench of a vibrating-wire alignment system for a series of multipole magnet on a straight section, we have achieved the total error of the magnetic-center measurements of micrometer-order in the standard deviation. Moreover, two systematic error factors, the drift of the magnetic centers due to thermal deformations of the magnets after they are excited and the change in the magnetic centers due to reassembly of the magnets after installing the vacuum chamber, are included in practical magnet alignments. We have experimentally investigated these error factors using the test bench.

3.
Horm Metab Res ; 47(4): 253-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25105541

ABSTRACT

Advanced glycation end products (AGEs) decrease adiponectin expression and suppress insulin signaling in cultured adipocytes through the interaction with a receptor for AGEs (RAGE) via oxidative stress generation. We have recently found that high-affinity DNA aptamer directed against AGE (AGE-aptamer) prevents the progression of experimental diabetic nephropathy by blocking the harmful actions of AGEs in the kidney. This study examined the effects of AGE-aptamer on adipocyte remodeling, AGE-RAGE-oxidative stress axis, and adiponectin expression in fructose-fed rats. Although AGE-aptamer treatment by an osmotic mini pump for 8 weeks did not affect serum insulin levels, it significantly decreased average fasting blood glucose and had a tendency to inhibit body weight gain in fructose-fed rats. Furthermore, AGE-aptamer significantly suppressed the increase in adipocyte size and prevented the elevation in AGEs, RAGE, and an oxidative stress marker, 8-hydroxydeoxyguanosine (8-OHdG), levels in adipose tissues of fructose-fed rats at 14-week-old, while it restored the decrease in adiponectin mRNA levels. Our present study suggests that AGE-aptamer could improve glycemic control and prevent adipocyte remodeling in fructose-fed rats partly by suppressing the AGE-RAGE-mediated oxidative stress generation. AGE-aptamer might be a novel therapeutic strategy for fructose-induced metabolic derangements.


Subject(s)
Adipocytes/pathology , Aptamers, Nucleotide/administration & dosage , Blood Glucose/analysis , Fructose/administration & dosage , Glycation End Products, Advanced/antagonists & inhibitors , Receptor for Advanced Glycation End Products/antagonists & inhibitors , Adipocytes/drug effects , Adiponectin/genetics , Animals , Cell Size/drug effects , Diet , Gene Expression/drug effects , Glycation End Products, Advanced/genetics , Insulin Resistance , Male , Oxidative Stress/drug effects , Rats , Rats, Wistar , Real-Time Polymerase Chain Reaction , Weight Gain/drug effects
4.
Climacteric ; 18(3): 426-30, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25340263

ABSTRACT

Advanced glycation endproducts (AGEs) and their receptor (RAGE) play a role in vascular complications in diabetes. We have previously shown that 17ß-estradiol at 10 nmol/l, a nearly identical plasma concentration to that during mid-pregnancy, up-regulates RAGE expression in endothelial cells. The finding might suggest the involvement of 17ß-estradiol in the deterioration of vascular complications in diabetes during pregnancy. However, the effects of the selective estrogen receptor modulator, bazedoxifene, on oxidative and inflammatory reactions in AGEs-exposed endothelial cells remain unknown. In this study, we addressed the issue. Ten nmol/l 17ß-estradiol increased RAGE and monocyte chemoattractant protein-1 (MCP-1) gene and protein expression in human umbilical vein endothelial cells (HUVECs), both of which were blocked by 10 nmol/l bazedoxifene. Bazedoxifene at 10 nmol/l also significantly inhibited the AGEs-induced superoxide generation, RAGE and MCP-1 gene and protein expression in HUVECs. The present study suggests that blockade of the AGEs-RAGE axis by bazedoxifene might be a novel therapeutic target for preventing vascular damage in diabetes, especially in postmenopausal women.


Subject(s)
Chemokine CCL2/metabolism , Human Umbilical Vein Endothelial Cells/metabolism , Indoles/administration & dosage , Receptor for Advanced Glycation End Products/metabolism , Selective Estrogen Receptor Modulators/administration & dosage , Superoxides/chemistry , Cells, Cultured , Chemokine CCL2/genetics , Humans , Oxidative Stress/drug effects , Receptor for Advanced Glycation End Products/genetics
5.
Cell Death Dis ; 5: e1215, 2014 May 08.
Article in English | MEDLINE | ID: mdl-24810051

ABSTRACT

Phospholipase C (PLC) is a key enzyme in phosphoinositide turnover. Among 13 PLC isozymes, PLCδ1 and PLCδ3 share high sequence homology and similar tissue distribution, and are expected to have functional redundancy in many tissues. We previously reported that the simultaneous loss of PLCδ1 and PLCδ3 caused embryonic lethality because of excessive apoptosis and impaired vascularization of the placenta. Prenatal death of PLCδ1/PLCδ3 double-knockout mice hampered our investigation of the roles of these genes in adult animals. Here, we generated PLCδ1/PLCδ3 double-knockout mice that expressed PLCδ1 in extra-embryonic tissues (cDKO mice) to escape embryonic lethality. The cDKO mice were born at the expected Mendelian ratio, which indicated that the simultaneous loss of PLCδ1 and PLCδ3 in the embryo proper did not impair embryonic development. However, half of the cDKO mice died prematurely. In addition, the surviving cDKO mice spontaneously showed cardiac abnormalities, such as increased heart weight/tibial length ratios, impaired cardiac function, cardiac fibrosis, dilation, and hypertrophy. Predating these abnormalities, excessive apoptosis of their cardiomyocytes was observed. In addition, siRNA-mediated simultaneous silencing of PLCδ1 and PLCδ3 increased apoptosis in differentiated-H9c2 cardiomyoblasts. Activation of Akt and protein kinase C (PKC) θ was impaired in the hearts of the cDKO mice. siRNA-mediated simultaneous silencing of PLCδ1 and PLCδ3 also decreased activated Akt and PKCθ in differentiated-H9c2 cardiomyoblasts. These results indicate that PLCδ1 and PLCδ3 are required for cardiomyocyte survival and normal cardiac function.


Subject(s)
Apoptosis , Cardiomyopathies/enzymology , Myocytes, Cardiac/enzymology , Phospholipase C delta/deficiency , Animals , Cardiomegaly/enzymology , Cardiomegaly/genetics , Cardiomegaly/pathology , Cardiomyopathies/genetics , Cardiomyopathies/pathology , Cardiomyopathies/physiopathology , Cell Differentiation , Cell Line , Cell Survival , Enzyme Activation , Fibrosis , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Genetic Predisposition to Disease , Isoenzymes/metabolism , Mice , Mice, Knockout , Myocytes, Cardiac/pathology , Phenotype , Phospholipase C delta/genetics , Protein Kinase C/metabolism , Protein Kinase C-theta , Proto-Oncogene Proteins c-akt/metabolism , RNA Interference , Rats , Time Factors , Transfection
6.
Dentomaxillofac Radiol ; 41(6): 460-5, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22116121

ABSTRACT

OBJECTIVES: The aims of this study were (1) to assess the validity of limited cone beam CT (CBCT) in detecting the distribution of bifid mandibular canals in the retromolar region by comparing its findings with those of panoramic radiography and spiral CT imaging, and (2) to confirm the contents of such canals depicted on limited CBCT images by using gross anatomical and histological methods. METHODS: Bilateral bifid mandibular canals of a Japanese cadaver were investigated. The canals depicted on panoramic radiography, spiral CT and limited CBCT images were compared. Cross-sectional limited CBCT images of these canals were compared with gross anatomical sections of the mandible and their contents were confirmed histologically. RESULTS: The spiral CT and limited CBCT images showed the bilateral bifid mandibular canals in the retromolar region whereas the panoramic radiographs indicated the presence of only the left bifid mandibular canal. The canal distribution was more distinct in the limited CBCT images than in the spiral CT images and the cross-sectional limited CBCT images were consistent with the gross anatomical sections. Histologically, the canals contained several nerve bundles and arteries among which the largest nerve and artery were of a similar size. CONCLUSION: Limited CBCT is valuable for assessing the distribution of bifid mandibular canals. It is clinically significant to accurately localize a bifid mandibular canal of the retromolar region because it contains a nerve bundle and artery.


Subject(s)
Cone-Beam Computed Tomography , Mandible/anatomy & histology , Mandible/diagnostic imaging , Cadaver , Humans , Radiography, Panoramic , Tomography, Spiral Computed
7.
Water Sci Technol ; 62(8): 1859-64, 2010.
Article in English | MEDLINE | ID: mdl-20962401

ABSTRACT

In order to assess the effects of climate change on flood disasters in urban areas, we applied a two dimensional finite element hydrodynamic model (2D-FEM) to simulate flood processes for the case analysis of levee breach caused by Kathleen Typhoon on 16 September 1947 in Kurihashi reach of Tone River, upstream of Tokyo area. The purpose is to use the model to simulate flood inundation processes under the present topography and land-use conditions with impending extreme flood scenarios due to climate change for mega-urban areas like Tokyo. Simulation used 100 m resolution topographic data (in PWRI), which was derived from original LiDAR (Light Detection and Ranging) data, and levee breach hydrographic data in 1947. In this paper, we will describe the application of the model with calibration approach and techniques when applying for such fine spatial resolution in urban environments. The fine unstructured triangular FEM mesh of the model appeared to be the most capable of introducing of constructions like roads/levees in simulations. Model results can be used to generate flood mapping, subsequently uploaded to Google Earth interface, making the modeling and presentation process much comprehensible to the general public.


Subject(s)
Disaster Planning/methods , Floods , Hydrodynamics , Models, Theoretical , Rivers , Computer Simulation , Tokyo , Urbanization
8.
Curr Mol Med ; 10(3): 317-20, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20236050

ABSTRACT

Pigment epithelium-derived factor (PEDF) is reported to play a protective role against diabetic vascular complications through its anti-oxidative properties. However, since a commercially available kit is not suitable for measurement of serum PEDF in humans, kinetics and regulation of serum PEDF are not known in these devastating disorders. Therefore, we developed a simple, specific and reliable method for measurement of serum PEDF in humans using a competitive enzyme-linked immunosorbent assay (ELISA) system. Assay linearity was shown intact with 50~300-fold dilution of urea-pretreated serum by phosphate-buffered saline. The recovery ratio of added recombinant human PEDF in serum was 94.2 +/- 1.7 %. Inter- and intra-assay coefficient of variations of the ELISA were 4.7 and 7.3 %, respectively. When we measured serum PEDF levels in a general population, PEDF levels were elevated in proportion to the accumulation of the number of the components of the metabolic syndrome. Further, the percent changes in serum levels of PEDF during 1-year observational periods were positively correlated with those of body mass index (BMI) in patients with type 2 diabetes. In addition, PEDF mRNA levels in cultured adipocytes were increased in parallel to the BMI values of subjects from which adipocytes were derived, especially in omental adipocytes. These observations suggest that PEDF is generated from adipose tissues and could be increased as a counter-system against vascular cell damage in humans. PEDF may be one of the useful biomarkers for vascular injury in high-risk patients.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Eye Proteins/blood , Nerve Growth Factors/blood , Serpins/blood , Biomarkers/blood , Enzyme-Linked Immunosorbent Assay/instrumentation , Enzyme-Linked Immunosorbent Assay/standards , Eye Proteins/genetics , Female , Humans , Male , Metabolic Syndrome/blood , Nerve Growth Factors/genetics , Oxidative Stress , Reference Standards , Renal Insufficiency/blood , Sensitivity and Specificity , Serpins/genetics
9.
Water Sci Technol ; 58(1): 73-81, 2008.
Article in English | MEDLINE | ID: mdl-18653939

ABSTRACT

This paper aims to elucidate retention characteristics of some pharmaceuticals and personal care products (PPCPs), and endocrine disrupting chemicals (EDCs), by two polyamide low pressure reverse osmosis (LPRO) membranes. Feed solution pH did not have an influence on rejections of undissociated solutes, which was most likely governed by adsorption, size exclusion and diffusion simultaneously. Size exclusion was presumably dominant, especially with tight membranes (UTC-70U). Rejections of the solutes with low dipole moment (<1.0 debye) decreased with increasing octanol-water partition coefficient (K(ow)). The solutes with large K(ow) values were most likely adsorbed on membrane and subsequently passed through it resulting in larger diffusion coefficient (D(p)). The rejections decreased with increasing D(p) values irrespective of their dipole moments. Rejections of solutes with comparatively larger dipole moments might be dominated by diffusion and/or convection rather than their hydrophobicity. However, rejections of solutes with hydroxyl and carboxyl functional groups by UTC-60 increased with solution pH. More than 80% rejections were obtained for degree of dissociation (alpha)>0.5. Electrostatic repulsion played a key role for rejection of dissociated solutes, especially by loose LPRO membranes. Therefore, assessing the dissociation degree at desired pH values can be a key step to obtain an insight of rejection mechanisms by polyamide membranes.


Subject(s)
Endocrine Disruptors/isolation & purification , Pharmaceutical Preparations/isolation & purification , Waste Disposal, Fluid/methods , Water Purification/methods , Adsorption , Chromatography, Gel , Equipment Design , Household Products/analysis , Humans , Hydrogen-Ion Concentration , Membrane Potentials , Osmosis , Ultrafiltration/methods , Urban Population , Waste Disposal, Fluid/instrumentation , Water Pollutants, Chemical/isolation & purification , Water Supply/standards
10.
Article in English | MEDLINE | ID: mdl-17584148

ABSTRACT

Diabetic nephropathy is a leading cause of end-stage renal failure, which could account for disabilities and high mortality rates in patients with diabetes. Diabetic nephropathy seems to occur as a result of an interaction between metabolic and hemodynamic factors, which activate common pathways that lead to renal damage. Recent large prospective clinical studies have shown that intensive glucose control reduces microvascular complications effectively among patients with diabetes, and the renin-angiotensin system (RAS) is also an important target for both metabolic and hemodynamic derangements in diabetic nephropathy. High glucose, via various mechanisms such as increased production of oxidative stress and advanced glycation end products (AGEs), activation of the RAS and protein kinase C (PKC), and stimulation of the polyol pathway, elicits vascular inflammation and alters gene expression of growth factors and cytokines, thereby it might be involved in the development and progression of diabetic nephropathy. Therefore, to develop novel therapeutic strategies that specifically target these metabolic and hemodynamic derangements is desired for patients with diabetic nephropathy. In this review, we discuss the molecular mechanisms of diabetic nephropathy and review the promising therapeutic targets for this devastating disorder.


Subject(s)
Diabetic Nephropathies/drug therapy , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/therapeutic use , Animals , Blood Circulation/physiology , Blood Glucose/metabolism , Cytokines/physiology , Diabetic Nephropathies/physiopathology , Glycation End Products, Advanced/metabolism , Humans , Intercellular Signaling Peptides and Proteins/physiology , Peroxisome Proliferator-Activated Receptors/metabolism , Peroxisome Proliferator-Activated Receptors/physiology
11.
Clin Nephrol ; 67(4): 255-9, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17474563

ABSTRACT

We report a case of tubulointerstitial nephritis and uveitis (TINU syndrome) with full type Fanconi syndrome. A 32-year-old woman presented with fatigue, anorexia and weight loss. Laboratory findings showed anemia, polyclonal hypergammaglobulinemia and moderate renal dysfunction. Tubular function abnormalities were normoglycemic glucosuria, panaminoaciduria, phosphaturia and kaliuresis leading to hypokalemia. Renal tubular acidosis and hypouricemia were also evident. Serum antistreptolysin O titer was high. Ocular symptoms (bilateral anterior uveitis) emerged soon after admission. Renal biopsy showed diffuse tubulointerstitial infiltration by lymphocytes and plasma cells without granuloma. Treatment with systemic steroids was given and renal function, and ocular symptom returned to normal with 3 months. Although tubular abnormalities involving TINU syndrome has already been reported, the disease associated with full type Fanconi syndrome has rarely been seen, and systemic steroid may be beneficial in reducing the development of tubulointerstitial injury.


Subject(s)
Fanconi Syndrome/diagnosis , Nephritis, Interstitial/diagnosis , Uveitis/diagnosis , Acute Disease , Adult , Anti-Inflammatory Agents/therapeutic use , Diagnosis, Differential , Fanconi Syndrome/complications , Fanconi Syndrome/drug therapy , Female , Humans , Nephritis, Interstitial/complications , Nephritis, Interstitial/drug therapy , Prednisolone/therapeutic use , Uveitis/complications , Uveitis/drug therapy
12.
Diabetologia ; 50(6): 1315-26, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17415547

ABSTRACT

AIMS/HYPOTHESIS: Plasminogen activator inhibitor-1 (PAI-1, also known as serpin peptidase inhibitor, clade E [nexin, plasminogen activator inhibitor type 1], member 1 [SERPINE1]) plays a pathogenetic role in renal fibrosis. It is upregulated in experimental and human diabetic nephropathy. These studies assessed the effect of PAI-1 deficiency and overproduction on renal disease in experimental diabetes. MATERIALS AND METHODS: Diabetes was induced by injection of streptozotocin in 6-week-old PAI-1-deficient mice, transgenic mice overexpressing Pai-1 and control mice. Animals were killed after 24 weeks of diabetes or after observation alone. RESULTS: Pai-1 mRNA was upregulated in kidneys from genetically normal mice with diabetes and in non-diabetic Pai-1 transgenic mice. PAI-1 was not further increased in kidneys from Pai-1 transgenic mice with diabetes. Diabetes-associated albuminuria and glomerular injury, as well as renal alpha-smooth muscle actin production, were ameliorated in diabetic PAI-1-deficient mice, an amelioration associated with attenuated increases in renal matrix metallopeptidase-2 expression and activity. Diabetic Pai-1 transgenic mice did not develop increased albuminuria or glomerular injury, but the tubulointerstitial area was modestly enhanced. In addition to the findings in diabetic mice, abnormalities also developed in 30-week-old PAI-1-deficient and Pai-1 transgenic mice without diabetes. PAI-1 deficiency resulted in increased tubulointerstitial area, TGFB1 protein and alpha-smooth muscle actin. Non-diabetic 30-week-old Pai-1 transgenic mice developed similar renal abnormalities and increased matrix metallopeptidase-2 activity, together with a modest increase in serum glucose and HbA(1c). CONCLUSIONS/INTERPRETATION: These results demonstrate that endogenous PAI-1 deficiency protects mice from glomerular injury in longer term diabetes and that endogenous PAI-1 maintains normal renal interstitial structure in ageing not associated with diabetes.


Subject(s)
Diabetes Mellitus, Experimental/physiopathology , Diabetic Nephropathies/genetics , Plasminogen Activator Inhibitor 1/genetics , Animals , Crosses, Genetic , Diabetes Mellitus, Experimental/pathology , Diabetic Nephropathies/pathology , Diabetic Nephropathies/prevention & control , Immunohistochemistry , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Plasminogen Activator Inhibitor 1/deficiency , RNA, Messenger/genetics , Serum Albumin/metabolism
13.
Exp Clin Endocrinol Diabetes ; 115(2): 69-84, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17318765

ABSTRACT

Diabetic nephropathy (DN), the most common cause of end stage renal disease in developed nations, is thought to result from interactions between metabolic and haemodynamic factors. Specific metabolically driven, glucose dependent pathways are activated within diabetic renal tissues. These pathways induce oxidative stress, polyol pathway flux, hexosamine flux and accumulation of advanced glycated end-products (AGEs). Haemodynamic factors are also implicated in the pathogenesis of DN and include elevations of systemic and intraglomerular pressure and activation of various vasoactive hormone pathways including the renin-angiotensin aldosterone system (RAAS), endothelin and urotensin. These altered hemodynamics act independently and in concert with metabolic pathways, to activate intracellular second messengers such as protein kinase C (PKC) and MAP kinase (MAPK), nuclear transcription factors such as nuclear factor-kappaB (NF-kappaB) and various growth factors such as the prosclerotic cytokines, transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF) and the angiogenic, permeability enhancing growth factor, vascular endothelial growth factor, VEGF. Ultimately these molecular mechanisms lead to increased renal albumin permeability, and extracellular matrix accumulation, which results in increasing proteinuria, glomerulosclerosis and tubulointerstitial fibrosis. In the past, the treatment of diabetic nephropathy has focused on control of hyperglycemia and the interruption of the RAAS with certain anti-hypertensive agents. Newer novel targets, some of which are linked to glucose dependent pathways, appear to be a major focus of new therapies directed against the development and progression of renal damage as a result of diabetes. It is likely that resolution of diabetic nephropathy will require synergistic therapies to target multiple mediators of this disease.


Subject(s)
Blood Circulation/physiology , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/physiopathology , Aldehyde Reductase/physiology , Animals , Cytokines/physiology , Glycation End Products, Advanced/physiology , Humans , Metabolic Networks and Pathways , Models, Biological , Oxidative Stress/physiology , Renin-Angiotensin System/physiology , Second Messenger Systems/physiology , Vasoconstriction/physiology , Vasodilation/physiology
14.
Science ; 292(5518): 920-3, 2001 May 04.
Article in English | MEDLINE | ID: mdl-11340203

ABSTRACT

Several phospholipase C (PLC) isoforms have been found in male and female mammalian gametes, and splicing isoforms of PLCdelta4 are predominantly expressed in testis. Here we report that male mice in which the PLCdelta4 gene had been disrupted either produced few small litters or were sterile. In vitro fertilization studies showed that insemination with PLCdelta4-/- sperm resulted in significantly fewer eggs becoming activated and that the calcium transients associated with fertilization were absent or delayed. PLCdelta4-/- sperm were unable to initiate the acrosome reaction, an exocytotic event required for fertilization and induced by interaction with the egg coat, the zona pellucida. These data demonstrate that PLCdelta4 functions in the acrosome reaction that is induced by the zona pellucida during mammalian fertilization.


Subject(s)
Acrosome/enzymology , Fertilization , Isoenzymes/metabolism , Type C Phospholipases/metabolism , Zona Pellucida/physiology , Acrosome Reaction , Animals , Calcium/metabolism , Calcium Signaling , Epididymis/enzymology , Female , Gene Targeting , Inositol Phosphates/metabolism , Isoenzymes/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Ovum/physiology , Phospholipase C delta , Sperm Capacitation , Sperm Injections, Intracytoplasmic , Spermatozoa/enzymology , Spermatozoa/metabolism , Testis/enzymology , Type C Phospholipases/genetics
15.
Biol Reprod ; 64(5): 1338-49, 2001 May.
Article in English | MEDLINE | ID: mdl-11319137

ABSTRACT

Injection of a porcine cytosolic sperm factor (SF) or of a porcine testicular extract into mammalian eggs triggers oscillations of intracellular free calcium ([Ca(2+)](i)) similar to those initiated by fertilization. To elucidate whether SF activates the phosphoinositide (PI) pathway, mouse eggs or SF were incubated with U73122, an inhibitor of events leading to phospholipase C (PLC) activation and/or of PLC itself. In both cases, U73122 blocked the ability of SF to induce [Ca(2+)](i) oscillations, although it did not inhibit Ca(2+) release caused by injection of inositol 1,4,5-triphosphate (IP(3)). The inactive analogue, U73343, had no effect on SF-induced Ca(2+) responses. To determine at the single cell level whether SF triggers IP(3) production concomitantly with a [Ca(2+)](i) rise, SF was injected into Xenopus oocytes and IP(3) concentration was determined using a biological detector cell combined with capillary electrophoresis. Injection of SF induced a significant increase in [Ca(2+)](i) and IP(3) production in these oocytes. Using ammonium sulfate precipitation, chromatographic fractionation, and Western blotting, we determined whether PLCgamma1, PLCgamma2, or PLCdelta4 and/or its splice variants, which are present in sperm and testis, are responsible for the Ca(2+) activity in the extracts. Our results revealed that active fractions do not contain PLCgamma1, PLCgamma2, or PLCdelta4 and/or its splice variants, which were present in inactive fractions. We also tested whether IP(3) could be the sensitizing stimulus of the Ca(2+)-induced Ca(2+) release mechanism, which is an important feature of fertilized and SF-injected eggs. Eggs injected with adenophostin A, an IP(3) receptor agonist, showed enhanced Ca(2+) responses to CaCl(2) injections. Thus, SF, and probably sperm, induces [Ca(2+)](i) rises by persistently stimulating IP(3) production, which in turn results in long-lasting sensitization of Ca(2+)-induced Ca(2+) release. Whether SF is itself a PLC or whether it acts upstream of the egg's PLCs remains to be elucidated.


Subject(s)
Adenosine/analogs & derivatives , Biological Factors/pharmacology , Calcium/metabolism , Phosphatidylinositols/metabolism , Adenosine/pharmacology , Alternative Splicing , Animals , Blotting, Western , Calcium Chloride/pharmacology , Cytosol/chemistry , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Estrenes/pharmacology , Female , Inositol 1,4,5-Trisphosphate/biosynthesis , Inositol 1,4,5-Trisphosphate/pharmacology , Isoenzymes/metabolism , Male , Microinjections , Oocytes/metabolism , Pyrrolidinones/pharmacology , Semen/chemistry , Swine , Testis/chemistry , Tissue Extracts/pharmacology , Type C Phospholipases/antagonists & inhibitors , Type C Phospholipases/genetics , Type C Phospholipases/metabolism , Xenopus
16.
J Cell Biol ; 152(3): 471-82, 2001 Feb 05.
Article in English | MEDLINE | ID: mdl-11157975

ABSTRACT

We identified a novel adaptor protein that contains a Src homology (SH)3 domain, SH3 binding proline-rich sequences, and a leucine zipper-like motif and termed this protein WASP interacting SH3 protein (WISH). WISH is expressed predominantly in neural tissues and testis. It bound Ash/Grb2 through its proline-rich regions and neural Wiskott-Aldrich syndrome protein (N-WASP) through its SH3 domain. WISH strongly enhanced N-WASP-induced Arp2/3 complex activation independent of Cdc42 in vitro, resulting in rapid actin polymerization. Furthermore, coexpression of WISH and N-WASP induced marked formation of microspikes in Cos7 cells, even in the absence of stimuli. An N-WASP mutant (H208D) that cannot bind Cdc42 still induced microspike formation when coexpressed with WISH. We also examined the contribution of WISH to a rapid actin polymerization induced by brain extract in vitro. Arp2/3 complex was essential for brain extract-induced rapid actin polymerization. Addition of WISH to extracts increased actin polymerization as Cdc42 did. However, WISH unexpectedly could activate actin polymerization even in N-WASP-depleted extracts. These findings suggest that WISH activates Arp2/3 complex through N-WASP-dependent and -independent pathways without Cdc42, resulting in the rapid actin polymerization required for microspike formation.


Subject(s)
Actins/metabolism , Adaptor Proteins, Signal Transducing , Carrier Proteins/metabolism , Cytoskeletal Proteins , Muscle Proteins , Nerve Tissue Proteins/metabolism , cdc42 GTP-Binding Protein/metabolism , Actin-Related Protein 2 , Actin-Related Protein 3 , Amino Acid Sequence , Animals , Blotting, Northern , Blotting, Western , Brain Chemistry , Carrier Proteins/chemistry , Carrier Proteins/genetics , Cattle , Cell Line , Cell Surface Extensions/metabolism , Culture Media, Serum-Free , GRB2 Adaptor Protein , Genes, Reporter , Humans , Leucine Zippers , Molecular Sequence Data , Polymers/metabolism , Protein Binding , Proteins/metabolism , Rats , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Wiskott-Aldrich Syndrome , Wiskott-Aldrich Syndrome Protein, Neuronal , src Homology Domains
17.
Jpn Heart J ; 41(4): 527-33, 2000 Jul.
Article in English | MEDLINE | ID: mdl-11041104

ABSTRACT

A 16-year-old Japanese male diagnosed with congestive heart failure (CHF) due to dilated cardiomyopathy was treated by conventional intensive treatment such as intravenous infusion of diuretics, catecholamines, and phosphodiesterase inhibitors with vasodilators. However, he developed a low output syndrome with appearances of hyponatremia and hypochloremia. As a consequence, intravenous infusion of carperitide (synthetic atrial natriuretic peptide) was added to the therapy. Thereafter his symptoms and hemodynamic parameters promptly and dramatically improved without significant diuresis, and this amelioration persisted for more than 20 days without drug intolerance. This outcome suggests that use of carperitide may be a safe and efficacious means to reduce cardiac preload without hypotension and tachycardia in patients with refractory CHF in whom intensive treatment has already been performed.


Subject(s)
Atrial Natriuretic Factor/therapeutic use , Bronchodilator Agents/therapeutic use , Cardiomyopathy, Dilated/complications , Diuretics/therapeutic use , Heart Failure/drug therapy , Heart Failure/physiopathology , Hemodynamics/drug effects , Peptide Fragments/therapeutic use , Adolescent , Drug Resistance, Multiple , Heart Failure/etiology , Humans , Infusions, Intravenous , Male
18.
Clin Nephrol ; 53(6): 479-82, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10879669

ABSTRACT

A 68-year-old male was admitted for interstitial pneumonia associated with scleroderma. High-dose methylprednisolone was administered for treatment of the pneumonitis. Two weeks later, anemia, thrombocytopenia and progressive increase in BUN, creatinine and LDH were observed. Although the blood pressure remained normotensive, renal biopsy showed thrombosis of the polar arterioles and glomerular capillaries. The affected interlobular artery included concentric intimal thickening and thrombosis in the lumen. Our findings suggested that the antecedent use of high-dose corticosteroids is involved in precipitating normotensive renal crisis. Corticosteroids should be used in low doses and with great caution in scleroderma patients.


Subject(s)
Anemia, Hemolytic/chemically induced , Glucocorticoids/adverse effects , Lung Diseases, Interstitial/drug therapy , Methylprednisolone/adverse effects , Renal Insufficiency/chemically induced , Scleroderma, Systemic/complications , Aged , Anemia, Hemolytic/pathology , Blood Pressure , Glucocorticoids/administration & dosage , Humans , Kidney/pathology , Lung Diseases, Interstitial/complications , Male , Methylprednisolone/administration & dosage , Renal Insufficiency/pathology
20.
J Cell Biol ; 149(7): 1455-72, 2000 Jun 26.
Article in English | MEDLINE | ID: mdl-10871285

ABSTRACT

The dynamic properties of the cell cortex and its actin cytoskeleton determine important aspects of cell behavior and are a major target of cell regulation. GAP43, myristoylated alanine-rich C kinase substrate (MARCKS), and CAP23 (GMC) are locally abundant, plasmalemma-associated PKC substrates that affect actin cytoskeleton. Their expression correlates with morphogenic processes and cell motility, but their role in cortex regulation has been difficult to define mechanistically. We now show that the three proteins accumulate at rafts, where they codistribute with PI(4,5)P(2), and promote its retention and clustering. Binding and modulation of PI(4, 5)P(2) depended on the basic effector domain (ED) of these proteins, and constructs lacking the ED functioned as dominant inhibitors of plasmalemmal PI(4,5)P(2) modulation. In the neuron-like cell line, PC12, NGF- and substrate-induced peripheral actin structures, and neurite outgrowth were greatly augmented by any of the three proteins, and suppressed by DeltaED mutants. Agents that globally mask PI(4,5)P(2) mimicked the effects of GMC on peripheral actin recruitment and cell spreading, but interfered with polarization and process formation. Dominant negative GAP43(DeltaED) also interfered with peripheral nerve regeneration, stimulus-induced nerve sprouting and control of anatomical plasticity at the neuromuscular junction of transgenic mice. These results suggest that GMC are functionally and mechanistically related PI(4,5)P(2) modulating proteins, upstream of actin and cell cortex dynamics regulation.


Subject(s)
Actins/metabolism , Calmodulin-Binding Proteins , Cell Membrane/metabolism , Cytoskeletal Proteins/metabolism , Cytoskeleton/metabolism , GAP-43 Protein/metabolism , Intracellular Signaling Peptides and Proteins , Membrane Proteins , Nerve Tissue Proteins , Phosphatidylinositol 4,5-Diphosphate/metabolism , Proteins/metabolism , Animals , Bradykinin/metabolism , Bradykinin/pharmacology , Cell Membrane/ultrastructure , Cytoskeletal Proteins/genetics , Cytoskeleton/ultrastructure , GAP-43 Protein/genetics , Hippocampus/metabolism , Hippocampus/ultrastructure , Mice , Mutation/physiology , Myristoylated Alanine-Rich C Kinase Substrate , Nerve Regeneration/drug effects , Nerve Regeneration/physiology , Neurites/metabolism , Neurites/ultrastructure , Neuromuscular Junction/drug effects , Neuromuscular Junction/metabolism , Neuromuscular Junction/ultrastructure , Neurons/metabolism , Neurons/ultrastructure , PC12 Cells , Peripheral Nerves/drug effects , Peripheral Nerves/metabolism , Peripheral Nerves/ultrastructure , Phosphatidylinositols/metabolism , Protein Structure, Tertiary/physiology , Proteins/genetics , Rats , Subcellular Fractions
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