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1.
J Comp Physiol B ; 188(4): 683-694, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29594459

RESUMEN

Hepcidin is the key regulator of iron homeostasis in the body. Iron storage disease (hemochromatosis) is a frequent cause of liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus), but reasons underlying this condition are unknown. Hereditary hemochromatosis in humans is due to deficiency of hepcidin or resistance to the action of hepcidin. Here, we investigated the role of hepcidin in iron metabolism in one species of pteropodid bat that is prone to iron storage disease [Egyptian fruit bat (with and without hemochromatosis)], one species of pteropodid bat where iron storage disease is rare [straw-colored fruit bat (Eidolon helvum)], and one species of bat with a natural diet very high in iron, in which iron storage disease is not reported [common vampire bat (Desmodus rotundus)]. Iron challenge via intramuscular injection of iron dextran resulted in significantly increased liver iron content and histologic iron scores in all three species, and increased plasma iron in Egyptian fruit bats and straw-colored fruit bats. Hepcidin mRNA expression increased in response to iron administration in healthy Egyptian fruit bats and common vampire bats, but not in straw-colored fruit bats or Egyptian fruit bats with hemochromatosis. Hepcidin gene expression significantly correlated with liver iron content in Egyptian fruit bats and common vampire bats, and with transferrin saturation and plasma ferritin concentration in Egyptian fruit bats. Induction of hepcidin gene expression in response to iron challenge is absent in straw-colored fruit bats and in Egyptian fruit bats with hemochromatosis and, relative to common vampire bats and healthy humans, is low in Egyptain fruit bats without hemochromatosis. Limited hepcidin response to iron challenge may contribute to the increased susceptibility of Egyptian fruit bats to iron storage disease.


Asunto(s)
Quirópteros/metabolismo , Hemocromatosis/metabolismo , Hepcidinas/genética , Complejo Hierro-Dextran/farmacología , Hierro/metabolismo , Hígado/efectos de los fármacos , Animales , Femenino , Hemocromatosis/veterinaria , Hígado/metabolismo , Masculino
2.
Res Vet Sci ; 96(1): 111-7, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24295741

RESUMEN

Hemochromatosis, or iron storage disease, has been associated with significant liver disease and mortality in captive Egyptian fruit bats (Rousettus aegyptiacus). The physiologic basis for this susceptibility has not been established. In humans, a deficiency or resistance to the iron regulatory hormone, hepcidin has been implicated in the development of hereditary hemochromatosis. In the present study, we compared the coding sequence of the hepcidin gene in eight species of bats representing three distinct taxonomic families with diverse life histories and dietary preferences. Bat hepcidin mRNA encoded a 23 amino acid signal peptide, a 34 or 35 amino acid pro-region, and a 25 amino acid mature peptide, similar to other mammalian species. Differences in the sequence of the portion of the hepcidin gene that encodes the mature peptide that might account for the increased susceptibility of the Egyptian fruit bat to iron storage disease were not identified. Variability in gene sequence corresponded to the taxonomic relationship amongst species.


Asunto(s)
Quirópteros/metabolismo , Variación Genética/fisiología , Hemocromatosis/veterinaria , Hepcidinas/metabolismo , Filogenia , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Quirópteros/genética , ADN/química , ADN/genética , Predisposición Genética a la Enfermedad , Variación Genética/genética , Hemocromatosis/genética , Hemocromatosis/metabolismo , Hepcidinas/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/veterinaria , Alineación de Secuencia , Análisis de Secuencia de ADN
3.
Insect Mol Biol ; 19 Suppl 2: 47-62, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20482639

RESUMEN

Aphids exhibit unique attributes, such as polyphenisms and specialized cells to house endosymbionts, that make them an interesting system for studies at the interface of ecology, evolution and development. Here we present a comprehensive characterization of the developmental genes in the pea aphid, Acyrthosiphon pisum, and compare our results to other sequenced insects. We investigated genes involved in fundamental developmental processes such as establishment of the body plan and organogenesis, focusing on transcription factors and components of signalling pathways. We found that most developmental genes were well conserved in the pea aphid, although many lineage-specific gene duplications and gene losses have occurred in several gene families. In particular, genetic components of transforming growth factor beta (TGFbeta) Wnt, JAK/STAT (Janus kinase/signal transducer and activator of transcription) and EGF (Epidermal Growth Factor) pathways appear to have been significantly modified in the pea aphid.


Asunto(s)
Áfidos/crecimiento & desarrollo , Áfidos/genética , Genes de Insecto , Secuencia de Aminoácidos , Animales , Áfidos/patogenicidad , Tipificación del Cuerpo/genética , Femenino , Eliminación de Gen , Duplicación de Gen , Genes Homeobox , Genoma de los Insectos , Proteínas de Insectos/genética , Masculino , Datos de Secuencia Molecular , Pisum sativum/parasitología , Filogenia , Receptores Citoplasmáticos y Nucleares/genética , Homología de Secuencia de Aminoácido , Transducción de Señal/genética , Factores de Transcripción/genética
4.
Insect Mol Biol ; 19 Suppl 2: 187-200, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20482650

RESUMEN

The pea aphid (Acyrthosiphon pisum) is the first whole genome sequenced insect with a hemimetabolic development and an emerging model organism for studies in ecology, evolution and development. The insect steroid moulting hormone 20-hydroxyecdysone (20E) controls and coordinates development in insects, especially the moulting/metamorphosis process. We, therefore present here a comprehensive characterization of the Halloween genes phantom, disembodied, shadow, shade, spook and spookiest, coding for the P450 enzymes that control the biosynthesis of 20E. Regarding the presence of nuclear receptors in the pea aphid genome, we found 19 genes, representing all of the seven known subfamilies. The annotation and phylogenetic analysis revealed a strong conservation in the class of Insecta. But compared with other sequenced insect genomes, three orthologues are missing in the Acyrthosiphon genome, namely HR96, PNR-like and Knirps. We also cloned the EcR, Usp, E75 and HR3. Finally, 3D-modelling of the ligand-binding domain of Ap-EcR exhibited the typical canonical structural scaffold with 12 alpha-helices associated with a short hairpin of two antiparallel beta-strands. Upon docking, 20E was located in the hormone-binding groove, supporting the hypothesis that EcR has a role in 20E signalling.


Asunto(s)
Áfidos/genética , Áfidos/metabolismo , Ecdisteroides/biosíntesis , Genes de Insecto , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Áfidos/crecimiento & desarrollo , Sitios de Unión , Clonación Molecular , Ecdisterona/biosíntesis , Genoma de los Insectos , Proteínas de Insectos/química , Insectos/genética , Insectos/metabolismo , Ligandos , Modelos Moleculares , Pisum sativum/parasitología , Filogenia , Conformación Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Citoplasmáticos y Nucleares/química , Receptores de Esteroides/química , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Transducción de Señal/genética
5.
J Chromatogr B Biomed Sci Appl ; 758(1): 81-6, 2001 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-11482738

RESUMEN

Using GC-MS, we studied urinary organic acids in 20 Japanese patients with peroxisomal disorders, including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy, and single deficiency of peroxisomal beta-oxidation enzymes. Non-ketotic dicarboxylic aciduria with elevated sebacate/adipate molar ratio was observed in 19 of the 20 patients. Elevation of 2-hydroxysebacate and epoxydicarboxylic acids were seen in 13 and 18, respectively. Tyrosyluria was remarkable in all patients. In two ZS patients, we tracked the time course from birth to infancy, and all the above stated findings were detected, except for one sample. Urinary organic acid analysis is indeed useful for screening subjects with peroxisomal disorders.


Asunto(s)
Ácidos/orina , Cromatografía de Gases y Espectrometría de Masas/métodos , Trastorno Peroxisomal/diagnóstico , Humanos , Lactante , Recién Nacido , Trastorno Peroxisomal/orina
6.
J Chromatogr B Biomed Sci Appl ; 758(1): 87-94, 2001 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-11482739

RESUMEN

There are several organic acid disorders that require information on alpha-ketoacids, such as maple syrup urine disease or alpha-ketoadipic acidemia. The recovery, stability and diagnostic availability of alpha-ketoacids in dried urine filter paper analyzed by GC-MS with oxime-trimethylsilyl derivatization was studied for organic acidemia screening. The recovery of all nine types of alpha-ketoacids tested, but for phenylpyruvate, 2-ketoadipate, and p-OH-phenylpyruvate, from filter paper samples was acceptable. The stability of pyruvate, branched-chain alpha-ketoacids, alpha-ketoadipate and alpha-ketoglutarate was stable for at least 28 days, although some alpha-ketoacids such as succinylacetone were unstable. It indicated it was difficult to diagnose only tyrosinemia type 1 among nine specimens from organic acidemia patients tested. The method could be applied to global organic acidemia screening.


Asunto(s)
Ácidos/sangre , Adipatos/sangre , Cromatografía de Gases y Espectrometría de Masas/métodos , Enfermedad de la Orina de Jarabe de Arce/diagnóstico , Adipatos/orina , Humanos , Enfermedad de la Orina de Jarabe de Arce/sangre , Enfermedad de la Orina de Jarabe de Arce/orina , Papel , Estándares de Referencia , Reproducibilidad de los Resultados
7.
J Infect Dis ; 183(7): 1031-7, 2001 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-11237827

RESUMEN

Twenty-three human T lymphotropic virus type I (HTLV-I) seroconverters were identified among 1120 HTLV-I-seronegative adults followed up for 11 years in an area of Japan endemic for HTLV-I. The geometric mean titer of anti-HTLV-I was 1:453 in the first year after seroconversion; the titer of each subject did not change significantly during 2-10 years of follow-up. HTLV-I proviral DNA load was quantified in 15 seroconverters, and a broad range of levels was observed-from <10 to >1000 copies/10(5) peripheral blood mononuclear cells. However, there was no obvious change in HTLV-I proviral DNA load over several years within individual subjects. Therefore, both proviral DNA load and humoral response in adult HTLV-I seroconverters were shown to stabilize within a few years after initial infection. In addition, 1 subject tested positive for HTLV-I proviral DNA before antibody seroconversion, which suggests the existence of a window period in community-acquired infection.


Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por HTLV-I/inmunología , Virus Linfotrópico T Tipo 1 Humano/inmunología , Provirus/inmunología , Anciano , Estudios de Cohortes , Servicios de Salud Comunitaria , ADN Viral/análisis , Femenino , Infecciones por HTLV-I/sangre , Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Humanos , Japón , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Provirus/genética , Provirus/aislamiento & purificación , Población Rural , Carga Viral
8.
J Chromatogr B Biomed Sci Appl ; 746(1): 63-73, 2000 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11048741

RESUMEN

A simplified, sensitive screening method for organic acidemias by gas chromatography-mass spectrometry using urease/direct preparations and tert.-butyldimethylsilylation (TBDMS) instead of trimethylsilylation (TMS) is described. We compiled GC-MS data on TBDMS derivatives, including methylene unit values, and quantifying and confirming ions, for use in the automated data system we developed. Quantification using [M-57]+ ions by mass chromatography was more sensitive, and the coefficient variation was smaller, compared with TMS derivatives. We confirmed the usefulness of this system, analyzing urine specimens from 53 patients with 15 different disorders.


Asunto(s)
Ácidos/sangre , Cromatografía de Gases y Espectrometría de Masas/métodos , Errores Innatos del Metabolismo/sangre , Compuestos de Organosilicio/química , Adolescente , Automatización , Niño , Preescolar , Humanos , Lactante , Recién Nacido
9.
J Chromatogr B Biomed Sci Appl ; 746(1): 75-82, 2000 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11048742

RESUMEN

Children with fructose-1,6-diphosphatase (FDPase) deficiency often experience life threatening episodes such as ketotic hypoglycemia. We report here a rapid, simplified and sensitive method to analyze glycerol-3-phosphate (G3P) and glycerol in urine, that can be used to detect FDPase deficiency. We used the urease/direct preparation and gas chromatography-mass spectrometry in the selected-ion monitoring mode, enabling detection of G3P and glycerol level in normal controls. Using this approach, FDPase deficiency can be more easily diagnosed and differentiated from glycerol kinase deficiency or glycerol infusion patients. To date, diagnosis has been essentially based on the assay of enzymes in the liver. The proposed non-invasive method provides a clinically significant diagnostic tool that may help prevent episodic attacks.


Asunto(s)
Fructosa-Bifosfatasa/orina , Cromatografía de Gases y Espectrometría de Masas/métodos , Errores Innatos del Metabolismo/diagnóstico , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Errores Innatos del Metabolismo/orina , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Ureasa/metabolismo
10.
Ryumachi ; 40(3): 627-32, 2000 Jun.
Artículo en Japonés | MEDLINE | ID: mdl-10920688

RESUMEN

A 29-year-old woman experienced Raynaud's phenomenon, swelling of her fingers, eruptions on her face, and muscle weakness in 1990. She was diagnosed as having mixed connective tissue disease (MCTD) and was treated with prednisolone (PSL) for 3 years. Most of her complaints disappeared after the treatment. In March 1997, she experienced fever, erythema, and lymphadenopathy. Although she was treated with PSL (20 mg/day) again, muscle weakness, mental disturbance, and recto-urinary disturbance appeared. When she was re-admitted to our hospital, increased levels of muscle-derived enzymes and positivity of anti-RNP antibody were found. High signal areas in her cerebrum were shown by magnetic resonance imaging, and slow and spike pattern was shown by electroencephalography. Hypoperfusion of the cerebral blood flow was suggested on single photon emission computed tomography. The number of mononuclear cells, amount of protein and level of interleukin-6 were found to be elevated in her cerebrospinal fluid (CSF). Her neurological manifestations were diagnosed as being due to MCTD, and showed characteristics similar to those of systemic lupus erythematosus. She was treated with PSL (60 mg/day) followed by steroid pulse therapy. Because the response to this treatment was partial, oral administration of cyclophosphamide (CPM) (100 mg/day) was added. Muscle weakness and neurological abnormalities as well as abnormal laboratory findings gradually improved over the following two months. We conclude that the treatment with CPM combined with PSL may be useful, when neurological manifestations of MCTD are serious and resistant to conventional therapy.


Asunto(s)
Enfermedades del Sistema Nervioso Central/etiología , Ciclofosfamida/administración & dosificación , Inmunosupresores/administración & dosificación , Lupus Eritematoso Sistémico/etiología , Enfermedad Mixta del Tejido Conjuntivo/complicaciones , Prednisolona/administración & dosificación , Adulto , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Quimioterapia Combinada , Femenino , Humanos , Lupus Eritematoso Sistémico/tratamiento farmacológico , Enfermedad Mixta del Tejido Conjuntivo/tratamiento farmacológico , Quimioterapia por Pulso , Resultado del Tratamiento
11.
Early Hum Dev ; 58(1): 41-55, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10785335

RESUMEN

A simplified method for organic acidemia screening using GC/MS, the urease/direct method, is now available. To establish a practical screening system for organic acidemias, we studied the usefulness of dried urine filter paper (filter paper urine) and the application of a personal computer-based system of automated metabolic profiling and interpretation (automated system) that we earlier developed. In a comparison of filter paper urine with liquid urine, creatinine levels ranging from 4.6 to 122.5 mg/dl, showed an excellent correlation (r=0.9554), when the volumes of blotted urine and distilled water soaked were the same. Recovery of all 17 compounds except for citrate was similar between liquid and filter paper urine. CV values of 22 compounds tested ranged from 5.5 to 22.4% in the liquid urine, and from 7.7 to 29.8% in the filter paper urine. The CV values in stable isotope dilution analysis were much smaller in all nine compounds tested. As to the stability of compounds, the percentage changes to values at day 0 were within about +/-25% on day 28. We compiled GC/MS data, including methylene unit values, quantifying and confirming ions of 163 different organic acids and others, to use the automated system. We analyzed specimens from 55 patients with 17 different metabolic disorders. In 54 of the 55 specimens, the correct diagnosis was successfully indicated. Neonatal mass screening for organic acidemias warrants ongoing attention using this simplified method and filter paper urine.


Asunto(s)
Acidosis/diagnóstico , Errores Innatos del Metabolismo/diagnóstico , Tamizaje Neonatal/métodos , Acidosis/orina , Adolescente , Autoanálisis , Niño , Preescolar , Estudios de Evaluación como Asunto , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Lactante , Recién Nacido , Masculino , Errores Innatos del Metabolismo/orina , Técnica de Dilución de Radioisótopos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
12.
Mod Rheumatol ; 10(3): 165-8, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24383595

RESUMEN

Abstract A 36-year-old male patient with dermatomyo-sitis (DM) associated with rapidly progressive interstitial pneumonia (IP) was successfully treated by high-dose intravenous immunoglobulin (IVIG). He suffered from myopathy, skin lesions, and IP. In spite of the treatment with a high-dose corticosteroid, IP progressed rapidly. Then high-dose intravenous immunoglobulin (20 g/day, 4 days) was administered. The skin lesions, myopathy, and pulmonary lesions improved. High-dose IVIG was considered to be a relatively safe and effective treatment for progressive IP associated with DM.

13.
Southeast Asian J Trop Med Public Health ; 30 Suppl 2: 174-80, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-11400763

RESUMEN

Gas chromatography mass spectrometry (GC/MS) is widely used in diagnosis of organic acidemias. However, GC/MS has not yet become a routine laboratory test, because of the complexity in interpretation of GC/MS data. We developed a personal computer-based system of automated metabolic profiling and disease detection for the screening of organic acidemias by GC/MS. The data were processed after the GC/MS analysis of urinary organic acids. In this system, 130 kinds of metabolites and 25 disorders of organic acids were enrolled for the search and detection, respectively. Metabolites were identified with methylene unit values (MU). target ions (Q- and C-ions) and their intensity ratios, and semiquantified by peak relative area (%) of the Q-ions to that of an internal standard. Metabolites whose values exceeded the cutoff of the control table were flagged as abnormal. The diseases or pathological condition were automatically evaluated by combination of the abnormal compounds. In this system, index metabolites were categorized into three groups. "AND, "OR" and "NO". The groups, "AND" and "OR" comprised essential and optional compounds, respectively, for the specific diagnosis. The third group, "NO", included compounds which must be absent to reach a diagnosis. We compiled data of MU values and mass spectrum of 130 kinds of index metabolites, and tested the usefulness of this system by analysis of 74 patients with 19 kinds of diseases. In all cases, at least a correct diagnosis could be found among the disease names outputted. We have successfully applied this to a pilot neonatal screening by GC/MS in our regional area, and acylglycine analysis by the stable isotope dilution method with tert-butyldimethylsilyl derivatization. With our system, many people can attend for screening programs using GC/MS.


Asunto(s)
Errores Innatos del Metabolismo de los Aminoácidos/diagnóstico , Diagnóstico por Computador , Cromatografía de Gases y Espectrometría de Masas , Urinálisis/métodos , Aminoácidos/orina , Humanos
14.
Rinsho Ketsueki ; 39(8): 565-73, 1998 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-9785974

RESUMEN

To clarify the efficacy of modern intensive chemotherapy for ALL patients with unfavorable features, we compared the time to failure and initial clinical features of children who relapsed in the bone marrow or combined sites, as documented by early CCLSG studies (H811 and H851; 1981-1987) and later studies (H874 and H/HH911; 1987-1993) concerning high-risk ALL patients. In the later studies patients outcomes with new intensive regimens employing early intensification and reinduction therapy were apparently better than those of patients in the early studies with conventional regimens. When we compared the number of relapsed patients based on duration of first remission, we found that the improved outcomes for patients in the later studies were due to a decrease in the number who relapsed 7-36 months after the start of treatment (intermediate relapse), and that the percentage of those who relapsed within the first 6 months of therapy (early relapse) was higher. Patients with high initial WBC counts tended to relapse much earlier than those with low initial WBC counts. However, in the later studies, patients with high WBC counts often relapsed after the termination of therapy (late relapse). These results suggest that the intensive chemotherapy regimens used in the later studies can prevent the development of drug resistant leukemic clones, except in extremely high-risk patients likely to relapse within the first 6 months of therapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Médula Ósea/etiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Niño , Preescolar , Femenino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Recurrencia , Riesgo , Factores de Tiempo
15.
Biochem Biophys Res Commun ; 231(3): 852-5, 1997 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-9070909

RESUMEN

We characterized the properties of the interaction between synapsin I and calspectin using purified proteins. The binding assay in the native state using antibodies specific to the tail region of synapsin I revealed that the binding is a high affinity with Kd of 9 nM, which is almost comparable to that of synapsin I to synaptic vesicles and to F-actin. We demonstrated that the head-middle region of synapsin I binds the NH2-terminal domain of beta subunit of calspectin, which also contains an actin binding site. Furthermore, the interaction was significantly inhibited by phosphorylation of synapsin I by cAMP-dependent protein kinase or by Ca2+, calmodulin-dependent protein kinase II. These properties of the interaction between synapsin I and calspectin may help understanding of its modulatory roles in neurotransmitter release.


Asunto(s)
Proteínas de Unión a Calmodulina/química , Sinapsinas/química , Animales , Proteínas Portadoras/química , Bovinos , Corteza Cerebral/química , Proteínas de Microfilamentos/química , Proteínas del Tejido Nervioso/química , Fosfoproteínas/química , Fosforilación , Pruebas de Precipitina , Unión Proteica , Relación Estructura-Actividad
16.
J Biol Chem ; 269(26): 17656-62, 1994 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-8021276

RESUMEN

Identification of annexin VI-binding proteins is essential to elucidate the physiological functions of annexin VI. Here, we developed the methods to identify an annexin VI-binding protein and characterized the binding. Annexin VI bound to about 14 species of proteins in the whole homogenate of rat forebrain, when examined with 125I-annexin VI using blots of SDS-polyacrylamide gels. The binding was Ca(2+)-dependent and specific for phosphatidylserine (PS) and phosphatidic acid. A line of evidence indicates that the binding of annexin VI to its target proteins is a protein-protein interaction. One of annexin VI-binding proteins with M(r) 240,000 was enriched in the cytoskeletal fraction and was identified as calspectin (brain spectrin or fodrin). When the binding was examined with purified calspectin in the native state, the Ca2+ affinity (KCa) was 7.6 microM, and the affinity for annexin VI (Kd) was 68 nM. Annexin VI bound to beta subunit of calspectin, but not to alpha subunit. The binding site was localized to the NH2-terminal domain of beta subunit, which contains an actin-binding site and exhibits striking homology with the NH2-terminal regions of dystrophin and alpha-actinin. When the effect of annexin VI on the interaction between F-actin and calspectin was examined by low shear viscometry, annexin VI inhibited the F-actin cross-linking activity of calspectin in a Ca2+/PS-dependent manner. Cosedimentation assay showed that annexin VI dissociates calspectin from F-actin in the presence of Ca2+ and PS. These results suggest that annexin VI can dissociate and redistribute calspectin in a Ca2+/phospholipid-dependent manner under the plasma membrane and that annexin VI may be involved in the regulation of the membrane skeleton of neuronal cells in response to Ca2+.


Asunto(s)
Anexina A6/metabolismo , Encéfalo/metabolismo , Proteínas de Unión a Calmodulina/metabolismo , Proteínas Portadoras/metabolismo , Proteínas de Microfilamentos/metabolismo , Espectrina/metabolismo , Actinas/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Calcio/metabolismo , Bovinos , Datos de Secuencia Molecular , Fosfolípidos/metabolismo , Ratas
17.
Ultrasound Med Biol ; 14 Suppl 1: 163-74, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3055589

RESUMEN

For breast tissue characterization, three acoustic parameters, integrated attenuation coefficient(IAC), frequency-dependent attenuation coefficient(FDAC) and instantaneous frequency(IF), were estimated in vitro and processed to make images of these parameters for resected human breast specimens. Experimental system with a 5 MHz center frequency was used and the same estimating and imaging system was connected with a clinical diagnostic device with a 7.5 MHz annular array probe (Aloca SSD 270) for in vivo type studies. To estimate these parameters, fast Fourier transform and spectral difference method were adopted for IAC and FDAC and the Hilbert transform for IF. Large statistical variances were found in the estimated values of these parameters. These dispersions of data may be due to insufficient size and tissue heterogeneity of the breast specimens. Additional miscellaneous problems may be involved. However, all of these can be, in part, overcome by averaging procedures. The significance of estimating and imaging these parameters for breast tissue characterization was discussed.


Asunto(s)
Enfermedades de la Mama/patología , Mama/patología , Ultrasonografía/métodos , Acústica , Anciano , Presentación de Datos , Femenino , Humanos , Microcomputadores , Persona de Mediana Edad , Análisis Espectral , Ultrasonografía/instrumentación
20.
Suicide Life Threat Behav ; 11(1): 17-30, 1981.
Artículo en Inglés | MEDLINE | ID: mdl-7233479

RESUMEN

The uniquely intense stress due to the Examination Hell (shiken jigoku) not only generates a basic drive for Japan's economic success but also contributes to a high rate of young people's suicide. This paper discusses the major factors in the intensity of Japanese stress on both institutional and psychological levels. The social structural factors which convert stress to suicide are analyzed in terms of weak ego; restraint on aggression; a lack of social resources; and views of life, death and suicide. Japanese views of life, death and suicide are treated in terms of Absolute phenomenalism, the original form of Shintoism, to which Buddhism and Confucianism have been adjusted in Japan. Japanese phenomenalism affects suicide through its three aspects: animism, present-time oriented small groupism, and the absolute acceptance of the established social order. Confusion and conflict since World War II have increased anomic suicides; however, elements of fatalistic suicide (due to excessive formal or informal social regulations) and altruistic suicide (due to excessive formal or informal social regulations) and altruistic suicide (due to strong social integration) are evident. Suicide is still a highly institutionalized adjustment mechanism in Japan.


Asunto(s)
Psicología del Adolescente , Suicidio/psicología , Adolescente , Adulto , Agresión/psicología , Niño , Preescolar , Conducta Competitiva , Dependencia Psicológica , Evaluación Educacional , Ego , Familia , Femenino , Humanos , Japón , Acontecimientos que Cambian la Vida , Masculino , Madres/psicología , Religión , Estrés Psicológico , Suicidio/epidemiología
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