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1.
JAR Life ; 12: 100-104, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38186668

RESUMEN

Background: Frailty increases the risk of falling, hospitalization, and premature death, necessitating practical early-detection tools. Objectives: To examine the discriminative ability of KinectTM-based stepping parameters for identifying frailty phenotype. Design: Population-based cross-sectional study. Setting: Eighteen neighborhoods near Tokyo Metropolitan Institute for Geriatrics and Gerontology, Itabashi, Tokyo, Japan. Participants: In total, 563 community-dwelling older adults aged ≥75 years without mobility limitations, neurological disease, or dementia were included. Measurements: Step number (SN) and knee total movement distance (KMD) during a 20-s stepping test were evaluated using the KinectTM infrared depth sensor. Results: The number (%) of participants with frailty were 51 (9.1). The area under the receiver operating characteristic curves (95% confidence interval) of a parameter consisting of SN and KMD for frailty was 0.72 (0.64, 0.79). Conclusions: Stepping parameters evaluated using KinectTM provided acceptable ability in identifying frailty phenotype, making it a practical screening tool in primary care and home settings.

2.
J Frailty Aging ; 8(4): 186-191, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31637404

RESUMEN

BACKGROUND: With increasing interest in addressing quality of life of older individuals, tests such as the Functional Independence Measure (FIM) are widely used measures of infirmity and burden of care. However, these scales are largely qualitative and especially problematic when assessing movement-based tasks. While effective, reliable analysis of human movement is technically complicated and expensive; an infrared depth sensor is potentially a low-cost, portable devise which may provide a quantitative aspect to clinical testing. OBJECTIVE: to assess the utility of the KinectTM sensor in providing an objective evaluation of human movement using an oft measured ADL (chair stand). DESIGN: Cross-sectional study. SETTING: Community, geriatric day-care center in Japan. PARTICIPANTS: Men (n=136) and women (n=266) between 50 and 93 years of age, consisting of healthy (HE; n=312) and physically frail (FR; n= 90) individuals. MEASUREMENTS: Subjects completed two trials of the chair stand, conducted without assistance. Trials were timed and recorded with KinectTM v2. Coronal plane angle (CPA) was determined by a line transecting the shoulder-center and waist relative to the vertical axis and was used to assess quality of the chair stand movement pattern. RESULTS: Age, height, and body mass were not different between groups. CPA was significantly greater in FR (29.3 ± 8.3°) than HE (19.5 ± 6.5°). CPA and age were significantly related (r=0.148, p<0.01). An optimal threshold for CPA identifying frailty was determined by a receiver-operator characteristic curve with a CPA of 23.1° providing the greatest combination of sensitivity (79%) and specificity (73%). CONCLUSION: During the chair stand, frail older adults adopted a forward lean position (increased CPA) compared to healthy older adults. This compensatory posture appears to facilitate torso rotation while reducing lower-limb muscular effort during standing. As such, CPA serves as an indicator of reduced lower-body function in older, frail adults.


Asunto(s)
Evaluación Geriátrica/métodos , Rendimiento Físico Funcional , Equilibrio Postural , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Anciano Frágil , Humanos , Japón , Masculino , Persona de Mediana Edad
3.
J Econ Entomol ; 103(6): 2034-41, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21309223

RESUMEN

The sterile insect technique (SIT) is widely used to suppress or eradicate target pest insect populations. Although the effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females, the use of gamma radiation to induce sterility negatively impacts reproductive cells as well as somatic cells. Consequently, sterilization by irradiation drastically diminishes mating performance over time. In the current study, we evaluated the effect of irradiation dose intensity on fertility, mating propensity, and mating competitiveness in sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae), for 16 d after irradiation. Although the mating propensity of males irradiated with 200 Gy, the dose currently used to induce complete sterility of C. f. elegantulus in the SIT program in Okinawa Prefecture, was equal to that of nonirradiated weevils for the first 6 d, the mating propensity of males irradiated with doses between of 75 and 150 Gy was maintained for the first 12 d. The potential fertilization ability of weevils was highly depressed compared with the control weevils, even in those treated with 75 Gy. Mating performance was severely compromised in weevils that were irradiated with a dose of 100 Gy or more. These results demonstrate that partial sterilization can be highly advantageous in eradication programs for the sweetpotato weevil. We discuss the advantages of the application of partial irradiation in insect eradication programs.


Asunto(s)
Rayos gamma , Longevidad/efectos de la radiación , Control Biológico de Vectores , Conducta Sexual Animal/efectos de la radiación , Gorgojos/efectos de la radiación , Animales , Conducta Competitiva , Femenino , Infertilidad Masculina/etiología , Masculino
4.
J Econ Entomol ; 101(4): 1198-203, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18767728

RESUMEN

The sterile insect technique (SIT) is widely used for suppressing or eradicating target pest insect populations. The effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females. Irradiation is the effective manner to sterilize mass-reared insects. The negative impacts of this procedure are not limited to damage on reproductive cells. Gamma-radiation damages the epithelial tissue of midgut, which affects the alimentation in insects. Irradiated males alter their mating behavior over time because of the depression of metabolic activity by sterilization. In this study, we evaluated the male mating performance and sexually compatibility of irradiated male Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae) with a 200-Gy dose, as currently used in the SIT program in Okinawa Prefecture, throughout 16 d after irradiation in the laboratory. The mating ability of irradiated males did not differ from that of control males for about a week. However, the mating ability of irradiated male drastically decreased thereafter. We consider that irradiated male C. formicarius elegantulus with a 200-Gy dose had no major effect on male mating behavior approximately for a week after irradiation.


Asunto(s)
Rayos gamma , Control Biológico de Vectores , Conducta Sexual Animal/efectos de la radiación , Gorgojos/efectos de la radiación , Animales , Femenino , Fertilidad/efectos de la radiación , Masculino
5.
Leukemia ; 22(5): 971-9, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18401414

RESUMEN

We examined the involvement of sphingosine kinase-1 (SphK1), which governs the ceramide/sphingosine-1-phosphate balance, in susceptibility to imatinib of either sensitive or resistant chronic myeloid leukemia cells. Imatinib-sensitive LAMA84-s displayed marked SphK1 inhibition coupled with increased content of ceramide and decreased pro-survival sphingosine-1-phosphate. Conversely, no changes in the sphingolipid metabolism were observed in LAMA84-r treated with imatinib. Overcoming imatinib resistance in LAMA84-r with farnesyltransferase or MEK/ERK inhibitors as well as with cytosine arabinoside led to SphK1 inhibition. Overexpression of SphK1 in LAMA84-s cells impaired apoptosis and inhibited the effects of imatinib on caspase-3 activation, cytochrome c and Smac release from mitochondria through modulation of Bim, Bcl-xL and Mcl-1 expression. Pharmacological inhibition of SphK1 with F-12509a or its silencing by siRNA induced apoptosis of both imatinib-sensitive and -resistant cells, suggesting that SphK1 inhibition was critical for apoptosis signaling. We also show that imatinib-sensitive and -resistant primary cells from chronic myeloid leukemia patients can be successfully killed in vitro by the F-12509a inhibitor. These results uncover the involvement of SphK1 in regulating imatinib-induced apoptosis and establish that SphK1 is a downstream effector of the Bcr-Abl/Ras/ERK pathway inhibited by imatinib but upstream regulator of Bcl-2 family members.


Asunto(s)
Apoptosis , Proteínas de Fusión bcr-abl/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Fosfotransferasas (Aceptor de Grupo Alcohol)/fisiología , Piperazinas/farmacología , Pirimidinas/farmacología , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis , Benzamidas , Benzoquinonas/farmacología , Resistencia a Antineoplásicos , Humanos , Mesilato de Imatinib , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal
6.
Leukemia ; 20(1): 95-102, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16281067

RESUMEN

We examined the involvement of sphingosine kinase-1, a critical regulator of the sphingolipid balance, in susceptibility to antineoplastic agents of either sensitive or multidrug-resistant acute myeloid leukemia cells. Contrary to parental HL-60 cells, doxorubicin and etoposide failed to trigger apoptosis in chemoresistant HL-60/Doxo and HL-60NP16 cells overexpressing MRP1 and MDR1, respectively. Chemosensitive HL-60 cells displayed sphingosine kinase-1 inhibition coupled with ceramide generation. In contrast, chemoresistant HL-60/ Doxo and HL-60/VP16 had sustained sphingosine kinase-1 activity and did not produce ceramide during treatment. Enforced expression of sphingosine kinase-1 in chemosensitive HL-60 cells resulted in marked inhibition of apoptosis that was mediated by blockade of mitochondrial cytochrome c efflux hence suggesting a control of apoptosis at the pre-mitochondrial level. Incubation with cell-permeable ceramide of chemoresistant cells led to a sphingosine kinase-1 inhibition and apoptosis both prevented by sphingosine kinase-1 over-expression. Furthermore, F-12509a, a new sphingosine kinase inhibitor, led to ceramide accumulation, decrease in sphingosine 1-phosphate content and caused apoptosis equally in chemosensitive and chemoresistant cell lines that is inhibited by adding sphingosine 1-phosphate or overexpressing sphingosine kinase-1. F-12509a induced classical apoptosis hallmarks namely nuclear fragmentation, caspase-3 cleavage as well as downregulation of antiapoptotic XIAP, and release of cytochrome c and SMAC/Diablo.


Asunto(s)
Resistencia a Múltiples Medicamentos , Leucemia Mieloide/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Enfermedad Aguda , Apoptosis/efectos de los fármacos , Benzoquinonas/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Ceramidas/biosíntesis , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Etopósido/farmacología , Células HL-60 , Humanos , Leucemia Mieloide/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/farmacología , Interferencia de ARN/fisiología , Receptores de Lisoesfingolípidos/metabolismo
7.
Phys Rev Lett ; 87(11): 112301, 2001 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-11531515

RESUMEN

Two-particle interferometry of positive kaons is studied in Pb+Pb collisions at mean transverse momenta approximately 0.25 and 0.91 GeV/c. A three-dimensional analysis was applied to the lower p(T) data, while a two-dimensional analysis was used for the higher p(T) data. We find that the source-size parameters are consistent with the m(T) scaling curve observed in pion-correlation measurements in the same collisions, and that the duration time of kaon emission is consistent with zero within the experimental sensitivity.

8.
J Antibiot (Tokyo) ; 54(5): 415-20, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11480884

RESUMEN

In the course of our screening for inhibitors of sphingosine kinase, we found two active compounds in a culture broth of a fungus, Zopfiella inermis SANK 15183. The structures of the compounds, named S-15183a and b, were elucidated by a combination of spectroscopic analyses to be new azaphilone-type metabolites. S-15183a and b inhibited sphingosine kinase from rat liver with IC50 values of 2.5 and 1.6 microM, respectively. S-15183a also inhibited endogenous SPH kinase activity in intact platelets.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Hongos Mitospóricos/química , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Esfingosina/química , Esfingosina/farmacología , Plaquetas/efectos de los fármacos , Plaquetas/enzimología , Sistema Libre de Células , Inhibidores Enzimáticos/aislamiento & purificación , Fermentación , Humanos , Hidrogenación , Espectroscopía de Resonancia Magnética , Hongos Mitospóricos/crecimiento & desarrollo , Hongos Mitospóricos/metabolismo , Espectrometría de Masa Bombardeada por Átomos Veloces , Esfingosina/análogos & derivados , Esfingosina/aislamiento & purificación , Especificidad por Sustrato
9.
Proc Natl Acad Sci U S A ; 98(2): 575-80, 2001 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-11136233

RESUMEN

Mutations in several genes encoding transcription factors of the hepatocyte nuclear factor (HNF) cascade are associated with maturity-onset diabetes of the young (MODY), a monogenic form of early-onset diabetes mellitus. The ability of the orphan nuclear receptor small heterodimer partner (SHP, NR0B2) to modulate the transcriptional activity of MODY1 protein, the nuclear receptor HNF-4alpha, suggested SHP as a candidate MODY gene. We screened 173 unrelated Japanese subjects with early-onset diabetes for mutations in this gene and found five different mutations (H53fsdel10, L98fsdel9insAC, R34X, A195S, and R213C) in 6 subjects as well as one apparent polymorphism (R216H), all present in the heterozygous state. Interestingly, all of the subjects with the mutations were mildly or moderately obese at onset of diabetes, and analysis of the lineages of these individuals indicated that the SHP mutations were associated with obesity rather than with diabetes. Therefore, an additional group of 101 unrelated nondiabetic subjects with early-onset obesity was screened for mutations in the SHP gene. Two of the previously observed mutations (R34X and A195S) and two additional mutations (R57W and G189E) were identified in 6 subjects, whereas no mutations were identified in 116 young nondiabetic lean controls (P = 0.0094). Functional studies of the mutant proteins show that the mutations result in the loss of SHP activity. These results suggest that genetic variation in the SHP gene contributes to increased body weight and reveal a pathway leading to this common metabolic disorder in Japanese.


Asunto(s)
Proteínas de Unión al ADN , Diabetes Mellitus Tipo 2/genética , Obesidad/genética , Receptores Citoplasmáticos y Nucleares/genética , Adolescente , Adulto , Edad de Inicio , Sustitución de Aminoácidos , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Peso al Nacer/genética , Peso Corporal/genética , Niño , Cromosomas Humanos Par 1/genética , Comorbilidad , Análisis Mutacional de ADN , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/etnología , Femenino , Regulación de la Expresión Génica , Genes Dominantes , Genes Recesivos , Predisposición Genética a la Enfermedad , Factor Nuclear 4 del Hepatocito , Heterocigoto , Humanos , Hiperinsulinismo/epidemiología , Hiperinsulinismo/etnología , Hiperinsulinismo/genética , Japón/epidemiología , Escala de Lod , Masculino , Persona de Mediana Edad , Mutación Missense , Obesidad/epidemiología , Obesidad/etnología , Linaje , Fosfoproteínas/fisiología , Mutación Puntual , Polimorfismo Genético , Factores de Transcripción/fisiología , Activación Transcripcional , Transfección , Células Tumorales Cultivadas
10.
Obstet Gynecol ; 96(5 Pt 2): 826-8, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11094224

RESUMEN

BACKGROUND: Myomatous erythrocytosis syndrome (erythrocytosis associated with a uterine myoma) has multiple proposed etiologies, one of which is altered erythropoietin production. CASE: A 28-year-old woman, gravida 0, para 0, presented with a solitary, degenerated uterine myoma that was 34-36 weeks' gestational size and erythrocytosis. After GnRH agonist treatment and myomectomy, the tumor was analyzed by reverse transcription-polymerase chain reaction. Specific erythropoietin primer with erythropoietin messenger RNA was noted. CONCLUSION: Erythropoietin production by myomata might cause erythrocytosis in myomatous erythrocytosis syndrome.


Asunto(s)
Leiomioma/complicaciones , Policitemia/complicaciones , Neoplasias Uterinas/complicaciones , Adulto , Eritropoyetina/metabolismo , Femenino , Expresión Génica , Humanos , Leiomioma/metabolismo , Leiomioma/patología , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patología
11.
J Antibiot (Tokyo) ; 53(8): 753-8, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11079796

RESUMEN

In the course of our screening for inhibitors of sphingosine kinase, we found a series of active compounds in a culture broth of a novel marine bacterium, SANK 71896. The structures of the compounds, named B-5354a, b and c, were elucidated by a combination of spectroscopic analyses to be new esters of 4-amino-3-hydroxybenzoic acid with long-chain unsaturated alcohols. B-5354a, b and c inhibit sphingosine kinase activity with IC50 values of 21, 58 and 38 microm, respectively.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Bacterias Gramnegativas/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , para-Aminobenzoatos , Ácido 4-Aminobenzoico/química , Ácido 4-Aminobenzoico/aislamiento & purificación , Ácido 4-Aminobenzoico/farmacología , Animales , Sistema Libre de Células , Inhibidores Enzimáticos/aislamiento & purificación , Fermentación , Bacterias Gramnegativas/clasificación , Concentración 50 Inhibidora , Estructura Molecular , Ratas , Microbiología del Agua
12.
J Antibiot (Tokyo) ; 53(8): 759-64, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11079797

RESUMEN

B-5354c is a new inhibitor of sphingosine kinase from a novel marine bacterium, SANK 71896. Kinetic study revealed that B-5354c inhibits sphingosine kinase with a Ki value of 12/microM. The inhibition is noncompetitive with respect to sphingosine. The compound also inhibits sphingosine-1-phosphate formation in human platelets. Experiments using synthetic derivatives of B-5354c indicate that all the three functional groups, i.e., the long unsaturated aliphatic chain, 4-amino and 3-hydroxyl groups are necessary to inhibit sphingosine kinase.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , para-Aminobenzoatos , Ácido 4-Aminobenzoico/química , Ácido 4-Aminobenzoico/farmacología , Animales , Plaquetas/efectos de los fármacos , Plaquetas/enzimología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Bacterias Gramnegativas/metabolismo , Humanos , Concentración 50 Inhibidora , Cinética , Ratas , Relación Estructura-Actividad , Especificidad por Sustrato
13.
Phys Rev Lett ; 85(13): 2681-4, 2000 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-10991207

RESUMEN

The invariant cross section as a function of transverse momentum for antideuterons produced in 158A GeV/c per nucleon Pb+Pb central collisions has been measured by the NA44 experiment at CERN. This measurement, together with a measurement of antiprotons, allows for the determination of the antideuteron coalescence parameter. The extracted coalescence radius is found to agree with the deuteron coalescence radius and radii determined from two particle correlations.

14.
Arch Virol ; 145(5): 905-20, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10881678

RESUMEN

Infection with measles virus induces a transient immunosuppression, which occasionally results in fatal opportunistic infections. To obtain fundamental information about the mechanism, we examined peripheral blood mononuclear cells (PBMC) from acute measles patients aged from infants to 35 years old, obtained at various times from incubation periods to 103 days after onset of rash, for the number of lymphocyte subsets by flowcytometry. The data were analyzed for relationships between aging of the patients and the severity of immunosuppression. In classical measles cases, infected lymphocytes detected as a minor population during the incubation period disappeared soon after onset of rash, whereas in the cases of serious illness, the infected cells persisted longer after the rash. At the onset of rash, remarkable lymphopenia had already occurred in all measles cases with reduction in cell numbers of CD4+ T cells, CD8+ T cells, B cells, neutrophils, and monocytes. In contrast, natural killer (NK) cells were increased in number and activated, which might be a response compensatory for the lymphopenia. Apoptosis-associated molecules such as CD95(Fas) and TNF-related apoptosis-inducing ligand-receptor (TRAIL-R) were highly expressed on the cell surface of most surviving non-infected lymphocytes, and DNA fragmentation was also observed upon incubation in vitro. These results suggested that the profound lymphopenia was primarily due to extended death of non-infected blood cells caused by apoptosis. The severity and duration of the lumphopenia were age-dependent; less severe in young children whereas much severer in infants under one year of age as well as adolescents and adults. From these results, it was suggested that remarkable lymphopenia due to apoptosis of uninfected cells is one of the principal causes for immunosuppression induced by measles virus infection, and is correlated with the age-dependent severity of the disease.


Asunto(s)
Linfocitos/patología , Linfopenia/sangre , Linfopenia/etiología , Sarampión/sangre , Sarampión/complicaciones , Enfermedad Aguda , Adolescente , Adulto , Factores de Edad , Anticuerpos Antivirales/sangre , Apoptosis , Niño , Preescolar , Humanos , Tolerancia Inmunológica , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Lactante , Células Asesinas Naturales/inmunología , Linfocitos/inmunología , Linfocitos/virología , Linfopenia/inmunología , Sarampión/inmunología , Virus del Sarampión/inmunología , Virus del Sarampión/aislamiento & purificación , Factores de Tiempo
15.
J Antibiot (Tokyo) ; 53(5): 459-66, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10908108

RESUMEN

In the course of our screening for inhibitors of sphingosine kinase, we found an active compound from a culture broth of a discomycete, Trichopezizella barbata SANK 25395. The structure of the compound, named F-12509A, was elucidated by a combination of spectroscopic analyses, to be a new sesquiterpene quinone consisting of a drimane moiety and a dihydroxybenzoquinone. Enzyme kinetic analyses showed that F-12509A inhibits sphingosine kinase activity in a competitive manner with respect to sphingosine, with a Ki value of 18 microM.


Asunto(s)
Ascomicetos/metabolismo , Benzoquinonas/farmacología , Inhibidores Enzimáticos/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Animales , Benzoquinonas/química , Benzoquinonas/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Cinética , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Microsomas/efectos de los fármacos , Microsomas/enzimología , Ratas , Ratas Wistar , Especificidad por Sustrato
16.
FEBS Lett ; 473(1): 81-4, 2000 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-10802064

RESUMEN

Sphingosine kinase catalyzes the phosphorylation of sphingosine to form sphingosine 1-phosphate (SPP), a novel lipid mediator with both intra- and extracellular functions. Based on sequence identity to murine sphingosine kinase (mSPHK1a), we cloned and characterized the first human sphingosine kinase (hSPHK1). The open reading frame of hSPHK1 encodes a 384 amino acid protein with 85% identity and 92% similarity to mSPHK1a at the amino acid level. Similar to mSPHK1a, when HEK293 cells were transfected with hSPHK1, there were marked increases in sphingosine kinase activity resulting in elevated SPP levels. hSPHK1 also specifically phosphorylated D-erythro-sphingosine and to a lesser extent sphinganine, but not other lipids, such as D,L-threo-dihydrosphingosine, N, N-dimethylsphingosine, diacylglycerol, ceramide, or phosphatidylinositol. Northern analysis revealed that hSPHK1 was widely expressed with highest levels in adult liver, kidney, heart and skeletal muscle. Thus, hSPHK1 belongs to a highly conserved unique lipid kinase family that regulates diverse biological functions.


Asunto(s)
Lisofosfolípidos , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Clonación Molecular , Citosol/enzimología , Perfilación de la Expresión Génica , Humanos , Membranas Intracelulares/enzimología , Cinética , Ratones , Datos de Secuencia Molecular , Fosforilación/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Fosfotransferasas (Aceptor de Grupo Alcohol)/química , ARN Mensajero/análisis , ARN Mensajero/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Esfingolípidos/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Esfingosina/farmacología , Especificidad por Sustrato , Transfección
17.
J Biol Chem ; 275(26): 19513-20, 2000 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-10751414

RESUMEN

Sphingosine-1-phosphate (SPP) has diverse biological functions acting inside cells as a second messenger to regulate proliferation and survival, and extracellularly, as a ligand for G protein-coupled receptors of the endothelial differentiation gene-1 subfamily. Based on sequence homology to murine and human sphingosine kinase-1 (SPHK1), which we recently cloned (Kohama, T., Oliver, A., Edsall, L. , Nagiec, M. M., Dickson, R., and Spiegel, S. (1998) J. Biol. Chem. 273, 23722-23728), we have now cloned a second type of mouse and human sphingosine kinase (mSPHK2 and hSPHK2). mSPHK2 and hSPHK2 encode proteins of 617 and 618 amino acids, respectively, both much larger than SPHK1, and though diverging considerably, both contain the conserved domains found in all SPHK1s. Northern blot analysis revealed that SPHK2 mRNA expression had a strikingly different tissue distribution from that of SPHK1 and appeared later in embryonic development. Expression of SPHK2 in HEK 293 cells resulted in elevated SPP levels. d-erythro-dihydrosphingosine was a better substrate than d-erythro-sphingosine for SPHK2. Surprisingly, d, l-threo-dihydrosphingosine was also phosphorylated by SPHK2. In contrast to the inhibitory effects on SPHK1, high salt concentrations markedly stimulated SPHK2. Triton X-100 inhibited SPHK2 and stimulated SPHK1, whereas phosphatidylserine stimulated both type 1 and type 2 SPHK. Thus, SPHK2 is another member of a growing class of sphingolipid kinases that may have novel functions.


Asunto(s)
Fosfotransferasas (Aceptor de Grupo Alcohol)/química , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Células 3T3 , Secuencia de Aminoácidos , Animales , Línea Celular , Clonación Molecular , Secuencia Conservada , ADN Complementario/metabolismo , Bases de Datos Factuales , Detergentes/farmacología , Relación Dosis-Respuesta a Droga , Humanos , Concentración de Iones de Hidrógeno , Riñón/enzimología , Cinética , Ratones , Datos de Secuencia Molecular , Fosfolípidos/farmacología , Fosforilación , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Sales (Química)/farmacología , Homología de Secuencia de Aminoácido , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Esfingosina/farmacología , Especificidad por Sustrato , Distribución Tisular
18.
Horm Res ; 54(1): 49-52, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11182636

RESUMEN

We have characterized HLA and insulin autoantibodies in a Japanese female patient with insulin autoimmune syndrome. Serological HLA typing demonstrated the patient had HLA-DR4, and DNA typing showed she had HLA-DRB1*0401 which has not been reported in patients with insulin autoimmune syndrome in Japan. A single binding affinity of insulin autoantibodies was demonstrated by Scatchard analysis and immunoglobulin class of insulin autoantibodies was exclusively IgG-kappa. HLA-DRB1*0406 is strikingly associated with patients with insulin autoimmune syndrome who have polyclonal insulin autoantibodies. The present report demonstrated the first Japanese patient with insulin autoimmune syndrome carrying HLA-DRB1*0401 who was revealed to have monoclonal insulin autoantibodies. The present results indicate that HLA molecules are the major determinants of polyclonal insulin autoantibodies and monoclonal insulin autoantibodies in insulin autoimmune syndrome.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Antígenos HLA-DR/genética , Anticuerpos Insulínicos/sangre , Anciano , Anciano de 80 o más Años , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/diagnóstico , Femenino , Cadenas HLA-DRB1 , Prueba de Histocompatibilidad , Humanos , Hipoglucemia/etiología , Inmunoglobulina A/sangre , Inmunoglobulina M/sangre , Insulina/sangre , Japón , Valores de Referencia , Síndrome
19.
J Cell Biol ; 147(3): 545-58, 1999 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-10545499

RESUMEN

Sphingosine-1-phosphate (SPP) is a bioactive lipid that has recently been identified as the ligand for the EDG family of G protein-coupled cell surface receptors. However, the mitogenic and survival effects of exogenous SPP may not correlate with binding to cell-surface receptors (Van Brocklyn, J.R., M.J. Lee, R. Menzeleev, A. Olivera, L. Edsall, O. Cuvillier, D.M. Thomas, P.J.P. Coopman, S. Thangada, T. Hla, and S. Spiegel. 1998. J. Cell Biol. 142:229-240). The recent cloning of sphingosine kinase, a unique lipid kinase responsible for the formation of SPP, has provided a new tool to investigate the role of intracellular SPP. Expression of sphingosine kinase markedly increased SPP levels in NIH 3T3 fibroblasts and HEK293 cells, but no detectable secretion of SPP into the medium was observed. The increased sphingosine kinase activity in NIH 3T3 fibroblasts was sufficient to promote growth in low- serum media, expedite the G(1)/S transition, and increase DNA synthesis and the proportion of cells in the S phase of the cell cycle with a concomitant increase in cell numbers. Transient or stable overexpression of sphingosine kinase in NIH 3T3 fibroblasts or HEK293 cells protected against apoptosis induced by serum deprivation or ceramide elevation. N,N-Dimethylsphingosine, a competitive inhibitor of sphingosine kinase, blocked the effects of sphingosine kinase overexpression on cell proliferation and suppression of apoptosis. In contrast, pertussis toxin did not abrogate these biological responses. In Jurkat T cells, overexpression of sphingosine kinase also suppressed serum deprivation- and ceramide-induced apoptosis and, to a lesser extent, Fas-induced apoptosis, which correlated with inhibition of DEVDase activity, as well as inhibition of the executionary caspase-3. Taken together with ample evidence showing that growth and survival factors activate sphingosine kinase, our results indicate that SPP functions as a second messenger important for growth and survival of cells. Hence, SPP belongs to a novel class of lipid mediators that can function inside and outside cells.


Asunto(s)
División Celular , Supervivencia Celular , Lisofosfolípidos , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Receptores Acoplados a Proteínas G , Sistemas de Mensajero Secundario , Esfingosina/análogos & derivados , Animales , Apoptosis/efectos de los fármacos , Caspasa 3 , Inhibidores de Caspasas , Caspasas/metabolismo , División Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citosol/metabolismo , ADN/biosíntesis , Activación Enzimática/efectos de los fármacos , Humanos , Ratones , Péptido Hidrolasas/metabolismo , Toxina del Pertussis , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Factor de Crecimiento Derivado de Plaquetas/farmacología , Receptores de Superficie Celular/antagonistas & inhibidores , Receptores de Superficie Celular/metabolismo , Receptores Lisofosfolípidos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sistemas de Mensajero Secundario/efectos de los fármacos , Esfingosina/antagonistas & inhibidores , Esfingosina/genética , Esfingosina/metabolismo , Esfingosina/farmacología , Transfección , Factores de Virulencia de Bordetella/farmacología , Receptor fas/metabolismo
20.
J Interferon Cytokine Res ; 18(10): 863-9, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9809622

RESUMEN

Leustroducsin B (LSN-B), a novel colony-stimulating factor (CSF) inducer, has been shown to have various biologic activities in vivo. To compare the CSF-inducing activity of LSN-B in vitro with that of the well-known cytokine inducer, interleukin-1beta (IL-1beta), bacterial lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA), we measured granulocyte (G)-CSF and granulocyte-macrophage (GM)-CSF levels that were induced with the stimuli in several mesenchymal cells. The results indicated that each stimulant displayed a different profile in the induction of G-CSF and GM-CSF. Next, to investigate if LSN-B induces cytokines other than G-CSF and GM-CSF, we characterized cytokines that were induced with LSN-B from bone marrow stromal cells (BMSCs). The results showed that a variety of cytokines, including G-CSF and GM-CSF, were induced in both clonal and primary BMSCs. From these results, we speculate that LSN-B induces cytokine production via a regulatory pathway distinct from that of IL-1beta, LPS, or PMA and that this signaling of LSN-B might lead to the production of a variety of cytokines in BMSCs. In addition, from our in vitro and in vivo results, we speculate that the biologic activities of LSN-B in vivo might be based on its own cytokine-inducing activity even though the target cell type of LSN-B in vivo remains to be determined.


Asunto(s)
Antibacterianos/farmacología , Citocinas/biosíntesis , Mesodermo/efectos de los fármacos , Línea Celular , Factor Estimulante de Colonias de Granulocitos/biosíntesis , Factor Estimulante de Colonias de Granulocitos y Macrófagos/biosíntesis , Humanos , Lactonas/farmacología , Mesodermo/citología , Mesodermo/metabolismo , Compuestos Organofosforados/farmacología , Pironas , Transducción de Señal/efectos de los fármacos
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