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1.
AJNR Am J Neuroradiol ; 43(11): 1575-1581, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36229164

RESUMEN

BACKGROUND AND PURPOSE: Despite advances in molecular imaging, preoperative diagnosis of astrocytomas and oligodendrogliomas can be challenging. In the present study, we assessed whether 7T SWI can be used to distinguish astrocytomas and oligodendrogliomas and whether malignant grading of gliomas is possible. MATERIALS AND METHODS: 7T SWI was performed on 21 patients with gliomas before surgery with optimization for sharp visualization of the corticomedullary junction. Scoring for cortical thickening and displacement of medullary vessels, characteristic of oligodendroglial tumors, and cortical tapering, characteristic of astrocytic tumors, was performed. Additionally, characteristics of malignancy, including thickening of the medullary veins, the presence of microbleeds, and/or necrosis were scored. RESULTS: Scoring for oligodendroglial (highest possible score, +3) and astrocytic (lowest score possible, -3) characteristics yielded a significant difference between astrocytomas and oligodendrogliomas (mean, -1.93 versus +1.71, P < .01). Scoring for malignancy was significantly different among the World Health Organization grade II (n = 10), grade III (n = 4), and grade IV (n = 7) tumors (mean, 0.20 versus 1.38 versus 2.79). Cortical thickening was observed significantly more frequently in oligodendrogliomas (P < .02), with a sensitivity of 71.4% and specificity of 85.7%; observation of tapering of the cortex was higher in astrocytomas (P < .01) with a sensitivity of 85.7% and specificity of 100%. CONCLUSIONS: Visualization of the corticomedullary junction by 7T SWI was useful in distinguishing astrocytomas and oligodendrogliomas. Observation of tapering of the cortex was most sensitive and specific for diagnosing astrocytomas. Reliably predicting malignant grade was also possible by 7T SWI.


Asunto(s)
Astrocitoma , Neoplasias Encefálicas , Glioma , Oligodendroglioma , Humanos , Oligodendroglioma/diagnóstico por imagen , Oligodendroglioma/patología , Neoplasias Encefálicas/patología , Astrocitoma/patología , Glioma/patología , Imagen por Resonancia Magnética
3.
Int J Lab Hematol ; 39(1): 112-117, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27885817

RESUMEN

INTRODUCTION: The prognostic value of serum ferritin level in patients with peripheral T-cell lymphoma (PTCL) remains unknown. METHODS: We retrospectively analyzed clinical data from 78 consecutive patients with newly diagnosed PTCL that were treated with anthracycline-containing regimens between 1998 and 2011. RESULTS: The patients consisted of 50 males and 28 females with a median age of 64 years (range, 16-83 years). The subtypes of PTCL were 39 PTCL, not otherwise specified and 39 angioimmunoblastic T-cell lymphoma (AITL). The median observation period for the surviving patients was 50 months. The overall survival (OS) was poorer in patients with serum ferritin level above the upper normal limit (n = 28), compared with patients with serum ferritin level within normal range (n = 50; 4-year OS: 23% vs. 72%; P < 0.001). In the multivariate analysis, poor performance status (P = 0.006) and elevated serum ferritin level (P = 0.018) were independent risk factors for poor OS. CONCLUSION: Serum ferritin level is a useful prognostic marker for PTCL.


Asunto(s)
Ferritinas/sangre , Linfoma de Células T Periférico/sangre , Linfoma de Células T Periférico/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antraciclinas/administración & dosificación , Supervivencia sin Enfermedad , Femenino , Humanos , Linfoma de Células T Periférico/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tasa de Supervivencia
4.
Transpl Infect Dis ; 17(6): 886-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26426525

RESUMEN

Amoebiasis has rarely been reported in patients undergoing hematopoietic stem cell transplantation, although it is a world-wide infection and extremely common. We present a case of intestinal amoebiasis unexpectedly revealed by colonoscopy after allogeneic bone marrow transplantation from a human leukocyte antigen-mismatched unrelated donor for acute myeloid leukemia arising from chronic myelomonocytic leukemia and successfully treated by metronidazole.


Asunto(s)
Antiprotozoarios/uso terapéutico , Trasplante de Médula Ósea/efectos adversos , Disentería Amebiana/tratamiento farmacológico , Enfermedad Injerto contra Huésped/complicaciones , Metronidazol/uso terapéutico , Disentería Amebiana/etiología , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad
5.
Sci Rep ; 5: 12833, 2015 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-26239746

RESUMEN

We have developed a cryogenic fluorescence microscope system, the core of which is a reflecting objective that consists of spherical and aspherical mirrors. The use of an aspherical mirror allows the reflecting objective to have a numerical aperture (NA) of up to 0.99, which is close to the maximum possible NA of 1.03 in superfluid helium. The performance of the system at a temperature of 1.7 K was tested by recording a three-dimensional fluorescence image of individual quantum dots using excitation wavelengths (λex) of 532 nm and 635 nm. At 1.7 K, the microscope worked with achromatic and nearly diffraction-limited performance. The 1/e(2) radius (Γ) of the point spread function of the reflecting objective in the lateral (xy) direction was 0.212 ± 0.008 µm at λex = 532 nm and was less than 1.2 times the simulated value for a perfectly polished objective. The radius Γ in the axial (z) direction was 0.91 ± 0.04 µm at λex = 532 nm and was less than 1.4 times the simulated value of Γ. The chromatic aberrations between the two wavelengths were one order of magnitude smaller than Γ in each direction.

7.
Stud Mycol ; 76(1): 1-29, 2013 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-24302788

RESUMEN

Phyllosticta is a geographically widespread genus of plant pathogenic fungi with a diverse host range. This study redefines Phyllosticta, and shows that it clusters sister to the Botryosphaeriaceae (Botryosphaeriales, Dothideomycetes), for which the older family name Phyllostictaceae is resurrected. In moving to a unit nomenclature for fungi, the generic name Phyllosticta was chosen over Guignardia in previous studies, an approach that we support here. We use a multigene DNA dataset of the ITS, LSU, ACT, TEF and GPDH gene regions to investigate 129 isolates of Phyllosticta, representing about 170 species names, many of which are shown to be synonyms of the ubiquitous endophyte P. capitalensis. Based on the data generated here, 12 new species are introduced, while epitype and neotype specimens are designated for a further seven species. One species of interest is P. citrimaxima associated with tan spot of Citrus maxima fruit in Thailand, which adds a fifth species to the citrus black spot complex. Previous morphological studies lumped many taxa under single names that represent complexes. In spite of this Phyllosticta is a species-rich genus, and many of these taxa need to be recollected in order to resolve their phylogeny and taxonomy. TAXONOMIC NOVELTIES: New species - Phyllosticta abieticola Wikee & Crous, P. aloeicola Wikee & Crous, P. citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, P. leucothoicola Wikee, Motohashi & Crous, P. mangifera-indica Wikee, Crous, K.D. Hyde & McKenzie, P. neopyrolae Wikee, Motohashi, Crous, K.D. Hyde & McKenzie, P. pachysandricola Wikee, Motohashi & Crous, P. paxistimae Wikee & Crous, P. podocarpicola Wikee, Crous, K.D. Hyde & McKenzie, P. rhaphiolepidis Wikee, C. Nakash. & Crous, P. rubra Wikee & Crous, P. vacciniicola Wikee, Crous, K.D. Hyde & McKenzie; New combinations - P. foliorum (Sacc.) Wikee & Crous, P. philoprina (Berk. & M.A. Curtis) Wikee & Crous; Epitypifications (basionyms) - P. concentrica Sacc., P. cussoniae Cejp, P. owaniana G. Winter; Neotypifications (basionyms) - Phyllosticta cordylinophila P.A. Young, Physalospora gregaria var. foliorum Sacc., Sphaeropsis hypoglossi Mont., Sphaeropsis minima Berk. & M.A. Curtis.

8.
Int J Lab Hematol ; 32(2): 222-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19573175

RESUMEN

We retrospectively investigated 31 myelodysplastic syndrome (MDS) patients receiving myeloablative hematopoietic stem cell transplantation (HCT) and focused on prognostic factors affecting the long-term outcome. Patients were classified according to the French-American-British classification and the HCT-comorbidity index was determined. Cytosine arabinoside or thiotepa combined with cyclophosphamide and total body irradiation was used as myeloablative conditioning in eight and 23 patients respectively. After a follow-up period of 0.8-14.2 years from transplantation (median: 6.4 years), 23 patients were alive in complete remission, and the 5-year overall survival (OS) and disease-free survival (DFS) rates were 79% and 72% respectively. The cumulative nonrelapse mortality (NRM) rate was 22% at 5 years. According to multivariate analysis, > or =20% blasts in the bone marrow and an HCT-comorbidity score > or = 3 were significantly associated with poor OS and DFS. Patients with a high HCT-comorbidity score and male patients receiving transplantation from female donors were significantly more likely to have a higher NRM according to the univariate, but not the multivariate analysis. These data suggest that comorbidity and the tumor burden at the time of transplantation may be useful variables for predicting the outcome in MDS patients receiving myeloablative HCT.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Síndromes Mielodisplásicos/terapia , Adulto , Factores de Edad , Biomarcadores de Tumor/sangre , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento , Carga Tumoral
9.
Radiother Oncol ; 91(1): 120-5, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18992952

RESUMEN

PURPOSE: Phase II studies in laryngeal and bladder carcinoma of accelerated radiotherapy with carbogen and nicotinamide (RT+CON) suggested a therapeutic advantage. Therefore, a randomized phase-III trial of RT+CON in locally advanced bladder carcinoma compared to radiotherapy (RT) alone was undertaken. METHODS: One hundred and sixty-five patients with muscle-invasive transitional cell bladder carcinoma were randomized to RT alone and 168 to RT+CON. This paper reports on compliance and toxicity to nicotinamide (NAM) and carbogen and on early radiation-induced adverse bowel and urinary events. RESULTS: Of those receiving RT+CON, 65-69% accepted all doses of NAM. Sixty-four percent of patients presented Grade 1 NAM toxicity (nausea or vomiting), which was severe in 13%. Compliance to carbogen was 85% and none (32 fractions) and 2% (20 fractions) of patients presented severe toxicity. The highest prevalence of severe radiation acute morbidity was seen for urinary frequency (RT: 18% and RT+CON: 15%) and for diarrhea (RT: 3% and RT+CON: 5%). CONCLUSIONS: There is no indication of an increase in radiation-induced morbidity by combining the tumour radiosensitizers carbogen and nicotinamide with radiotherapy. Late morbidity and treatment outcome will ultimately determine if there is a therapeutic benefit.


Asunto(s)
Dióxido de Carbono/uso terapéutico , Carcinoma de Células Transicionales/radioterapia , Niacinamida/uso terapéutico , Oxígeno/uso terapéutico , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Neoplasias de la Vejiga Urinaria/radioterapia , Anciano , Anciano de 80 o más Años , Dióxido de Carbono/efectos adversos , Carcinoma de Células Transicionales/patología , Fraccionamiento de la Dosis de Radiación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Niacinamida/efectos adversos , Oxígeno/efectos adversos , Fármacos Sensibilizantes a Radiaciones/efectos adversos , Dosificación Radioterapéutica , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/patología
10.
Proc Natl Acad Sci U S A ; 98(20): 11224-9, 2001 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-11553771

RESUMEN

Possible target proteins of chloroplast thioredoxin (Trx) have been investigated in the stroma lysate of spinach chloroplasts. For that purpose, we immobilized a mutant of m-type Trx in which an internal cysteine at the active site was substituted with serine, on cyanogen bromide-activated resin. By using this resin, the target proteins in chloroplast were efficiently acquired when they formed the mixed-disulfide intermediates with the immobilized Trxs. We could acquire Rubisco activase (45 kDa) and 2-Cys-type peroxiredoxin (Prx), which were recently identified as targets of chloroplast Trxs. Glyceraldehyde-3-phosphate dehydrogenase and sedoheputulose 1,7-bisphosphatase, well-known thiol enzymes in the Calvin cycle, also were recognized among the collected proteins, suggesting the method is applicable for our purpose. Furthermore, four proteins were identified from a homology search of the NH(2)-terminal sequence of the acquired proteins: glutamine synthetase, a protein homologous to chloroplast cyclophilin, a homolog of Prx-Q, and the Rubisco small subunit. The Trx susceptibilities of the recombinant cyclophilin and Prx-Q of Arabidopsis thaliana were then examined. The method developed in the present study is thus applicable to investigate the various redox networks via Trxs and the related enzymes in the cell.


Asunto(s)
Cloroplastos/metabolismo , Peroxidasas/metabolismo , Tiorredoxinas/química , Tiorredoxinas/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Arabidopsis/metabolismo , Sitios de Unión , Clonación Molecular , Ciclofilinas/química , Ciclofilinas/metabolismo , Cisteína , Disulfuros/análisis , Glutamato-Amoníaco Ligasa/química , Glutamato-Amoníaco Ligasa/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/química , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Peroxidasas/química , Peroxirredoxinas , Monoéster Fosfórico Hidrolasas/química , Monoéster Fosfórico Hidrolasas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estructura Secundaria de Proteína , Subunidades de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Resinas de Plantas , Ribulosa-Bifosfato Carboxilasa/metabolismo , Serina , Spinacia oleracea/metabolismo
11.
Brain Res Cogn Brain Res ; 11(1): 39-46, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11240110

RESUMEN

The purpose of this study was to determine the relationship between the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and subjective pain estimation when heterotopically painful stimulation was delivered to humans. The noxious electrical conditioning stimuli were applied to the left median nerve in noxious session I and the right median nerve in noxious session II for 10 min. The amplitude of the late component and visual analogue scale (VAS) value were both decreased significantly by conditioning stimuli in both sessions. The maximum decreases in SEP amplitude and VAS value induced by conditioning stimuli were respectively 40.2 and 37.2% in noxious session I and 49.3 and 42.3% in noxious session II. After-effect was observed 5 min after removal of the conditioning stimuli. The rates of decrease were thus nearly the same and independent of the site of conditioning stimulation in noxious sessions I and II. The SEP amplitude was significantly correlated with VAS values. The present study revealed that SEP amplitude and subjective pain intensity estimated by VAS following electrical tooth stimulation can be decreased by noxious stimuli to hand. This finding that heterotopic painful stimulation attenuates experimentally-induced tooth pain suggests a triggering of diffuse noxious inhibitory control (DNIC) with after-effect in trigeminal region.


Asunto(s)
Potenciales Evocados Somatosensoriales/fisiología , Dimensión del Dolor/métodos , Diente/fisiología , Adulto , Condicionamiento Psicológico/fisiología , Estimulación Eléctrica/métodos , Mano/inervación , Humanos , Masculino , Nervio Mediano/fisiología , Inhibición Neural/fisiología , Tiempo de Reacción/fisiología
12.
Biochem J ; 352 Pt 3: 783-8, 2000 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11104686

RESUMEN

Chloroplast ATP synthase is a thiol-modulated enzyme whose DeltamuH(+)-linked activation is strongly influenced by reduction and the formation of a disulphide bridge between Cys(199) and Cys(205) on the gamma subunit. In solubilized chloroplast coupling factor 1 (CF(1)), reduction of the disulphide bond elicits the latent ATP-hydrolysing activity. To assess the regulatory importance of the amino acid residues around these cysteine residues, we focused on the three negatively charged residues Glu(210)-Asp-Glu(212) close to the two cysteine residues and also on the following region from Leu(213) to Ile(230), and investigated the modulation of ATPase activity by chloroplast thioredoxins. The mutant gamma subunits were reconstituted with the alpha and beta subunits from F(1) of the thermophilic bacterium Bacillus PS3; the active ATPase complexes obtained were purified by gel-filtration chromatography. The complex formed with a mutant gamma subunit in which Glu(210) to Glu(212) had been deleted was inactivated rather than activated by reduction of the disulphide bridge by reduced thioredoxin, indicating inverse regulation. This complex was insensitive to the inhibitory CF(1)-epsilon subunit when the mutant gamma subunit was oxidized. In contrast, the deletion of Glu(212) to Ile(230) converted the complex from a modulated state into a highly active state.


Asunto(s)
Cloroplastos/enzimología , Mutación/genética , ATPasas de Translocación de Protón/química , ATPasas de Translocación de Protón/metabolismo , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos/genética , Bacillus/enzimología , Disulfuros/metabolismo , Ditiotreitol/metabolismo , Ditiotreitol/farmacología , Activación Enzimática/efectos de los fármacos , Datos de Secuencia Molecular , Oxidación-Reducción/efectos de los fármacos , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Subunidades de Proteína , ATPasas de Translocación de Protón/genética , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Sustancias Reductoras/metabolismo , Sustancias Reductoras/farmacología , Rotación , Tiorredoxinas/metabolismo , Tiorredoxinas/farmacología
13.
Nihon Rinsho ; 58(8): 1685-8, 2000 Aug.
Artículo en Japonés | MEDLINE | ID: mdl-10944935

RESUMEN

Sleep splint, which is a dental device made of regin, is now widely used for the treatment of obstructive sleep apnea in our country. This device is worn in the mouth at night and makes the upper airway opened during sleep. It enlarges the velopharyngeal space as well as the space at the tongue base and prevents the collapse of the upper airway. This device is a treatment of choice for the patients with mild or moderate types of obstructive sleep apnea who are not treated ordinarily by nasal CPAP. When the patients have nasal obstruction, adenoid hypertrophy, enlarged tonsils, or improper conditions of the teeth, sleep splint is not indicated for those patients. At first, nasal obstruction should be treated, and the adenoids and enlarged tonsils should be removed surgically. The compliance of this treatment is better than that of nasal CPAP, and the major complication of this treatment is almost none.


Asunto(s)
Ferulas Oclusales , Apnea Obstructiva del Sueño/terapia , Humanos , Obstrucción Nasal , Ferulas Oclusales/efectos adversos , Paladar Blando/fisiopatología , Faringe/fisiopatología , Apnea Obstructiva del Sueño/fisiopatología , Lengua/fisiopatología
14.
J Biochem ; 127(5): 931-7, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10788805

RESUMEN

FtsH of Escherichia coli is an essential membrane-integrated ATP-dependent protease. We cloned a gene for an FtsH homolog (T. FtsH) from Thermus thermophilus HB8, expressed it in E. coli, and purified the expressed protein. ATPase activity of T.FtsH was activated by proteins with unfolded structure ( alpha-casein and pepsin), and T.FtsH digested these proteins in an ATP-, Zn(2+)-dependent manner. alpha-Lactalbumin was digested by T.FtsH when it was largely unfolded, but not in its native form. Analysis of the proteolytic products revealed that, in most cases, T.FtsH cleaved the C-terminal side of hydrophobic residues and produced a characteristic set of small peptides (<30 kDa) without releasing a large intermediate. Thus, T.FtsH recognizes the unfolded structure of the proteins and progressively digests them at the expense of ATP. A soluble domain of T.FtsH, which lacked the N-terminal two transmembrane helices, was also prepared but was found to retain neither ATPase nor protease activities. Thus, the membrane segment appeared to be indispensable for these activities of T.FtsH.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas de la Membrana/metabolismo , Metaloendopeptidasas/metabolismo , Pliegue de Proteína , Thermus thermophilus/enzimología , Proteasas ATP-Dependientes , Adenosina Trifosfatasas/genética , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Caseínas/metabolismo , Clonación Molecular , Proteínas de Escherichia coli , Genes Bacterianos , Lactalbúmina/metabolismo , Proteínas de la Membrana/genética , Metaloendopeptidasas/genética , Datos de Secuencia Molecular , Pepsina A/metabolismo , Desnaturalización Proteica , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato , Thermus thermophilus/genética , Zinc
15.
Carbohydr Res ; 325(3): 177-82, 2000 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-10795808

RESUMEN

The conformation of maltose-type oligomers in water and in dimethylsulfoxide (Me2SO) was studied using two-dimensional NMR spectra. In Me2SO all of the oligomers have a 1a-type conformation. In water, they tend to adopt the same conformation, but the oligomers are looser and more flexible than in Me2SO.


Asunto(s)
Amilosa/síntesis química , Glucanos/síntesis química , Glucosa/química , Maltosa/química , Conformación de Carbohidratos , Óxido de Deuterio/química , Espectroscopía de Resonancia Magnética , Agua/química
16.
J Biol Chem ; 275(17): 12388-92, 2000 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-10777521

RESUMEN

Chaperones of Thermus thermophilus cooperate in reactivation of heat-inactivated proteins. The protein, inactivated at a high temperature in a TDnaKJ-GrpE set, recovered its activity during subsequent incubation with TClpB at moderate temperature (Motohashi, K., Watanabe, Y., Yohda, M., and Yoshida, M. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 7184-7189). Here, we report that the addition of chaperonin (Tcpn) at moderate temperature improves the yield of the TDnaKJ-GrpE-ClpB-dependent reactivation. The trap-Tcpn, which binds substrate protein but does not release it, inhibits reactivation severely. Maximum recovery is gained at sub-stoichiometric amounts of each component of TDnaKJ, TGrpE, and TClpB relative to the substrate monomer. These observations indicate that, driven by ATP hydrolysis, TDnaKJ-GrpE-ClpB chaperones catalytically cooperate and release heat-inactivated protein as a non-native, chaperonin-recognizable folding intermediate.


Asunto(s)
Proteínas Bacterianas/fisiología , Chaperoninas/fisiología , Proteínas de Escherichia coli , Proteínas HSP70 de Choque Térmico/fisiología , Proteínas de Choque Térmico/fisiología , Endopeptidasa Clp , Glucosafosfato Deshidrogenasa/metabolismo , Proteínas del Choque Térmico HSP40 , Calor , Chaperonas Moleculares/fisiología , Plásmidos , Unión Proteica , Factores de Tiempo , alfa-Glucosidasas/metabolismo
17.
J Bacteriol ; 182(8): 2200-6, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10735863

RESUMEN

Using a library of genomic DNA from Desulfovibrio vulgaris Miyazaki F, a strict anaerobe, and two synthetic deoxyoligonucleotide probes designed for F-type ATPases, the genes for open reading frames (ORFs) 1 to 5 were cloned and sequenced. The predicted protein sequences of the gene products indicate that they are composed of 172, 488, 294, 471, and 134 amino acids, respectively, and that they share considerable identity at the amino acid level with delta, alpha, gamma, beta, and epsilon subunits found in other F-type ATPases, respectively. Furthermore, a component carrying ATPase activity was partially purified from the cytoplasmic membrane fraction of the D. vulgaris Miyazaki F cells. The N-terminal amino acid sequences of three major polypeptides separated by sodium dodecyl sulfate-12% polyacrylamide gel electrophoresis were identical to those of the products predicted by the sequences of ORF-2, ORF-3, and ORF-4, suggesting that an F-type ATPase is functioning in the D. vulgaris Miyazaki F cytoplasmic membrane. The amount of the F-type ATPase produced in the D. vulgaris Miyazaki F cells is similar to that in the Escherichia coli cells cultured aerobically. It indicates that the enzyme works as an ATP synthase in the D. vulgaris Miyazaki F cells in connection with sulfate respiration.


Asunto(s)
Desulfovibrio vulgaris/genética , ATPasas de Translocación de Protón/genética , Sulfatos/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Desulfovibrio vulgaris/enzimología , Transporte de Electrón , Genes Bacterianos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , ATPasas de Translocación de Protón/aislamiento & purificación
18.
FEBS Lett ; 468(2-3): 189-93, 2000 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-10692584

RESUMEN

Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (Sph-1-P) are known as structurally related bio-active lipids activating platelets through their respective receptors. Although the receptors for LPA and Sph-1-P have been recently identified in various cells, the identification and characterization of ones in platelets have been reported only preliminarily. In this report, we first investigated the distinct modes of LPA and Sph-1-P actions in platelet activation and found that LPA functioned as a much stronger agonist than Sph-1-P, and high concentrations of Sph-1-P specifically desensitized LPA-induced intracellular Ca(2+) mobilization. In order to identify the responsible receptors underlying these observations, we analyzed the LPA and Sph-1-P receptors which might be expressed in human platelets, by RT-PCR. We found for the first time that Edg2, 4, 6 and 7 mRNA are expressed in human platelets.


Asunto(s)
Plaquetas/fisiología , Lisofosfolípidos/farmacología , Neutrófilos/fisiología , Agregación Plaquetaria/efectos de los fármacos , Receptores de Superficie Celular/sangre , Receptores Acoplados a Proteínas G , Esfingosina/análogos & derivados , Plaquetas/efectos de los fármacos , Calcio/sangre , Humanos , Técnicas In Vitro , Células Jurkat , Cinética , Neutrófilos/efectos de los fármacos , Activación Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/fisiología , ARN Mensajero/sangre , Receptores de Superficie Celular/efectos de los fármacos , Receptores de Superficie Celular/genética , Receptores del Ácido Lisofosfatídico , Receptores Lisofosfolípidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Esfingosina/farmacología
19.
J Biol Chem ; 274(48): 33991-4, 1999 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-10567363

RESUMEN

Since the report by Sternweis and Smith (Sternweis, P. C., and Smith, J. B. (1980) Biochemistry 19, 526-531), the epsilon subunit, an endogenous inhibitor of bacterial F(1)-ATPase, has long been thought not to inhibit activity of the holo-enzyme, F(0)F(1)-ATPase. However, we report here that the epsilon subunit is exerting inhibition in F(0)F(1)-ATPase. We prepared a C-terminal half-truncated epsilon subunit (epsilon(DeltaC)) of the thermophilic Bacillus PS3 F(0)F(1)-ATPase and reconstituted F(1)- and F(0)F(1)-ATPase containing epsilon(DeltaC). Compared with F(1)- and F(0)F(1)-ATPase containing intact epsilon, those containing epsilon(DeltaC) showed uninhibited activity; severalfold higher rate of ATP hydrolysis at low ATP concentration and the start of ATP hydrolysis without an initial lag at high ATP concentration. The F(0)F(1)-ATPase containing epsilon(DeltaC) was capable of ATP-driven H(+) pumping. The time-course of pumping at low ATP concentration was faster than that by the F(0)F(1)-ATPase containing intact epsilon. Thus, the comparison with noninhibitory epsilon(DeltaC) mutant shed light on the inhibitory role of the intact epsilon subunit in F(0)F(1)-ATPase.


Asunto(s)
Proteínas/química , ATPasas de Translocación de Protón/antagonistas & inhibidores , Adenosina Trifosfato/metabolismo , Bacillus/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/fisiología , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Hidrólisis , Cinética , Liposomas , Proteínas/aislamiento & purificación , Proteínas/fisiología , ATPasas de Translocación de Protón/química , ATPasas de Translocación de Protón/metabolismo , Factores de Tiempo , Proteína Inhibidora ATPasa
20.
Proc Natl Acad Sci U S A ; 96(13): 7184-9, 1999 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-10377389

RESUMEN

Functional chaperone cooperation between Hsp70 (DnaK) and Hsp104 (ClpB) was demonstrated in vitro. In a eubacterium Thermus thermophilus, DnaK and DnaJ exist as a stable trigonal ring complex (TDnaK.J complex) and the dnaK gene cluster contains a clpB gene. When substrate proteins were heated at high temperature, none of the chaperones protected them from heat inactivation, but the TDnaK.J complex could suppress the aggregation of proteins in an ATP- and TGrpE-dependent manner. Subsequent incubation of these heated preparations at moderate temperature after addition of TClpB resulted in the efficient reactivation of the proteins. Reactivation was also observed, even though the yield was low, if the substrate protein alone was heated and incubated at moderate temperature with the TDnaK.J complex, TGrpE, TClpB, and ATP. Thus, all these components were necessary for the reactivation. Further, we found that TGroEL/ES could not substitute TClpB.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas de Escherichia coli , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Bacterianas/genética , Clonación Molecular , Endopeptidasa Clp , Regulación Bacteriana de la Expresión Génica , Proteínas del Choque Térmico HSP40 , Proteínas HSP70 de Choque Térmico/genética , Proteínas de Choque Térmico/genética , Chaperonas Moleculares/genética , Datos de Secuencia Molecular , Thermus thermophilus
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