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1.
Oceanology (Wash D C) ; 62(1): 139-141, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35310928

RESUMEN

The paper presents brief results of comprehensive studies of the water area of the Tatar Strait and Sea of Japan obtained on cruise 61 of the R/V "Akademik Oparin" in November-December 2020. The bottom relief and geophysical and gas-geochemical fields were refined, and new features of the geochemistry and mineralogy of bottom sediments were revealed.

2.
Folia Morphol (Warsz) ; 73(3): 353-8, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25242249

RESUMEN

BACKGROUND: The aim of this study was to establish standards for determining sex from fragmentary and complete femurs in a Korean population. MATERIALS AND METHODS: The statistical analysis of 12 variables (6 about breadth and 6 about length) based on 100 Korean femurs (from 50 males and 50 females) showed that all variables have significant sex differences. RESULTS: The most accurate discriminant variable was the condylar breadth parallel with epicondylar breadth (87.6% accuracy). In contrast, the transverse shaft diameter was not a discriminant variable for sex determination (67.0% accuracy). Breadth-related variables were generally more accurate than length-related variables. Three variables (vertical diameter of the neck [VDN], medial epicondylarlength [MCL], and condylar breadth [CB]) were selected from stepwise analysis fordiscriminating sex (93.5% accuracy). The discriminating equation was as follows: 0.171 × VDN + 0.172 × MCL + 0.128 × CB2 - 21.471. CONCLUSIONS: The results of this study are helpful for determining sex, even if a femur is found in a fragmented condition in the field.

3.
J Nanosci Nanotechnol ; 11(2): 1397-400, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21456197

RESUMEN

We applied the scanning probe lithographic technique to a graphite patterning in air and analyzed the patterned sample with the lateral force microscopy and Raman spectroscopy. The local electric field generated from a tip caused either etching or oxidization depending on the electric field intensity in air. We have found that the frictional force between the tip and local oxidized graphite surface was increased remarkably from lateral force analysis. Also, it was found that the graphene layer was peeled from the graphite surface in the etching process, which could be a potential tool as a top-down nano-fabrication process for the graphene nano device without contamination.

4.
Br J Cancer ; 100(2): 298-304, 2009 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-19127259

RESUMEN

This prospective study was conducted with the Korean Cancer Study Group to evaluate the efficacy and safety of cetuximab combined with modified FOLFOX6 (mFOLFOX6) as first-line treatment in recurrent or metastatic gastric cancer and to identify potential predictive biomarkers. Patients received cetuximab 400 mg m(-2) at week 1 and 250 mg m(-2) weekly thereafter until disease progression. Oxaliplatin (100 mg m(-2)) and leucovorin (100 mg m(-2)) were administered as a 2-h infusion followed by a 46-h continuous infusion of 5-fluorouracil (2400 mg m(-2)) every 2 weeks for a maximum of 12 cycles. Biomarkers potentially associated with efficacy were analysed. Among 38 evaluable patients, confirmed response rate (RR) was 50.0% (95% CI 34.1-65.9). Median time-to-progression (TTP) was 5.5 months (95% CI 4.5-6.5) and overall survival (OS) 9.9 months. Eleven patients having tumour EGFR expression by immunohistochemistry with low serum EGF and TGF-alpha levels showed a 100% RR compared to 37.0% in the remaining 27 patients (P<0.001). Moreover, ligand level increased when disease progressed in seven out of eight patients with EGFR expression and low baseline ligand level. No patient exhibited EGFR amplification or K-ras mutations. Gastric cancer patients with EGFR expression and low ligand levels had better outcomes with cetuximab/mFOLFOX6 treatment.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/análisis , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Gástricas/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales Humanizados , Cetuximab , Femenino , Fluorouracilo/administración & dosificación , Humanos , Leucovorina/administración & dosificación , Neoplasias Hepáticas/química , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Estadificación de Neoplasias , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino , Neoplasias Peritoneales/química , Neoplasias Peritoneales/secundario , Pronóstico , Estudios Prospectivos , Neoplasias Gástricas/química , Neoplasias Gástricas/patología , Tasa de Supervivencia , Resultado del Tratamiento
5.
Neuroscience ; 152(3): 609-17, 2008 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-18313230

RESUMEN

This study aimed to clarify changes in the spatial expressions of types 1, 2 and 3 ryanodine receptors (RyR1, RyR2 and RyR3) in the cerebellum of a Ca(2+) channel alpha(1A) subunit mutant, rolling mouse Nagoya. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) revealed that the mRNA signal levels of RyR1 and RyR3 were altered in the rolling cerebellum, which exhibited lower densities of RyR1 bands and higher densities of RyR3 bands than in the control cerebellum. Quite consistent with the RT-PCR results, the staining intensity of RyR1 and RyR3 was altered in the rolling cerebellum. RyR1 immunostaining appeared in somata and the proximal dendrites of Purkinje cells, and the staining intensity of both subcellular regions was equally lower in all cerebellar lobules of rolling mice than in those of controls. Although RyR3 immunostaining appeared in the dendrites of granule cells, more intense RyR3 staining in rolling mice than in controls was uniformly observed throughout all cerebellar lobules. The present study further examined co-localizations of ryanodine receptor subtypes and voltage-gated Ca(2+) channel alpha(1) subunits in the rolling cerebellum. Somatodendritic RyR1 immunostaining in Purkinje cells overlapped with either a mutated Ca(2+) channel alpha(1A) subunit (P/Q-type), or a Ca(2+) channel alpha(1C) subunit (L-type; dihydropyridine receptor) immunostaining. Immunostaining of these alpha(1) subunits also emerged in granule cells. Those results suggest non-region-related alterations in RyR1 and RyR3 expressions in the rolling mouse cerebellum. Such expressional changes in ryanodine receptor subtypes may be involved in Ca(2+) channel alpha(1A) subunit gene mutation, and may alter regulation of intracellular Ca(2+) concentrations in cerebellar cortical neurons.


Asunto(s)
Ataxia Cerebelosa/metabolismo , Corteza Cerebelosa/metabolismo , Neuronas/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Animales , Canales de Calcio Tipo L/genética , Canales de Calcio Tipo L/metabolismo , Canales de Calcio Tipo Q/genética , Canales de Calcio Tipo Q/metabolismo , Señalización del Calcio/genética , Ataxia Cerebelosa/genética , Ataxia Cerebelosa/fisiopatología , Corteza Cerebelosa/patología , Corteza Cerebelosa/fisiopatología , Dendritas/metabolismo , Dendritas/patología , Predisposición Genética a la Enfermedad/genética , Masculino , Ratones , Ratones Mutantes Neurológicos , Neuronas/patología , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Células de Purkinje/metabolismo , Células de Purkinje/patología , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Canal Liberador de Calcio Receptor de Rianodina/genética , Transmisión Sináptica/genética
6.
Cancer Res ; 54(15): 4150-4, 1994 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-7913412

RESUMEN

Taxol, a microtubule-stabilizing agent, has been shown to have antineoplastic activity against various tumors. In addition, it has been shown that taxol resembles bacterial lipopolysaccharide in its ability to activate macrophages. Recently we have shown that lipopolysaccharide induces the expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) in murine B-cell lines. In light of the similarity of taxol and lipopolysaccharide in their effects on macrophages, we tested whether taxol could also induce the expression of GM-CSF in B-cell lines. In the present study we used the murine B-lymphoma cell line M12.4.1. In unstimulated cells, no GM-CSF mRNA was detected, whereas in taxol-stimulated stimulated cells at a concentration of 30 microM, GM-CSF mRNA was induced 4-8 h after stimulation. This induction of GM-CSF mRNA was down-regulated by 10 ng/ml of interleukin 4. Actinomycin D chase experiments revealed that interleukin 4 did not affect the half-life of the taxol-induced GM-CSF cytoplasmic mRNA, nor did it alter GM-CSF gene transcription. Polymerase chain reaction analysis of nuclear RNA, utilizing probes specific for sequences in the first intron of GM-CSF, indicated that taxol enhances accumulation of nuclear precursor RNA and that interleukin 4 decreases this accumulation. The present study shows a novel activity of taxol in inducing the release of the hematopoietic growth factor GM-CSF from B-cells. Since GM-CSF is known to recruit macrophages and enhance their cytotoxicity against tumor cells, our observations suggest that part of the known antitumor activity of taxol may be due to synergistic effects of GM-CSF activity together with direct cytotoxic actions through microtubule stabilization.


Asunto(s)
Núcleo Celular/metabolismo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/biosíntesis , Interleucina-4/farmacología , Linfoma de Células B/metabolismo , Paclitaxel/farmacología , ARN Mensajero/biosíntesis , Animales , Secuencia de Bases , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Semivida , Lipopolisacáridos/farmacología , Ratones , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Células Tumorales Cultivadas
7.
J Mol Biol ; 271(3): 342-8, 1997 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-9268663

RESUMEN

The KpnAI restriction-modification (R-M) system has been identified in Klebsiella pneumoniae strain M5a1. The restriction gene of KpnAI was first cloned into pBR322 using an r-m+ M5a1 derivative and phage SBS for screening. Subsequently, an adjacent DNA fragment showing modification activity was cloned into pUC19. A total of 7.2 kb DNA sequencing data revealed three open reading frames, corresponding to hsdR, hsdM and hsdS genes of type I R-M systems. The predicted hsdR, hsdM and hsdS-coded peptides shared 95%, 98% and 44% identity, respectively, with the corresponding peptides of the recently identified StySBLI system, a prototype of the type ID family. This high homology suggests that KpnAI is also a member of the type ID family. The KpnAI system seems to be the first type I system identified in Klebsiella species.


Asunto(s)
Enzimas de Restricción-Modificación del ADN/genética , Klebsiella pneumoniae/enzimología , Clonación Molecular , Escherichia coli , Genes Bacterianos , Prueba de Complementación Genética , Klebsiella pneumoniae/genética , Péptidos/química , Mapeo Restrictivo , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/genética
8.
FASEB J ; 15(13): 2390-400, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11689464

RESUMEN

The effectiveness of catalytic RNAs (ribozymes) should be increased when they are colocalized to the same intracellular compartment as their RNA targets. We colocalized ribozymes with their mRNA targets in an animal model by using the discrete RNA localization signals present in the 3' untranslated regions (UTRs) of Drosophila bicoid and oskar mRNAs. These signals have been fused to a lacZ mRNA target and hammerhead ribozymes targeted against lacZ. Ribozyme efficacy was first assessed by an oligodeoxyribonucleotide-based assay to identify the most accessible sites for ribozyme interaction on native lacZ transcripts in ovary extracts. The most accessible sequence was used for the design and in vivo testing of a hammerhead ribozyme. When the ribozyme and target with synonymous 3' UTRs were expressed in the same ovaries, colocalization could be indirectly demonstrated by in situ hybridization. Colocalized ribozyme and target mRNAs resulted in a two- to threefold enhancement of ribozyme function compared with noncolocalized transcripts. This study provides the first demonstration of functional ribozyme target colocalization in an animal model.


Asunto(s)
Proteínas de Drosophila , Drosophila/genética , Oocitos/metabolismo , ARN Catalítico/metabolismo , ARN Mensajero/metabolismo , Regiones no Traducidas 3'/genética , Regiones no Traducidas 3'/metabolismo , Animales , Animales Modificados Genéticamente , Secuencia de Bases , Femenino , Proteínas de Homeodominio/genética , Hibridación in Situ , Proteínas de Insectos/genética , Operón Lac/genética , Masculino , Datos de Secuencia Molecular , Ovario/metabolismo , Plásmidos/genética , ARN Catalítico/genética , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transactivadores/genética , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismo
9.
Leukemia ; 17(7): 1375-83, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12835727

RESUMEN

The aim of this study was to evaluate the potential of tumor-necrosis-factor-related apoptosis-inducing ligand TRAIL to eradicate leukemia cell lines, while sparing normal hematopoietic stem cells. Human Jurkat and Molt-4 cell lines were used to optimize the purging process in umbilical cord blood (UCB) mononuclear cells. The Jurkat cell line was TRAIL sensitive and TRAIL-resistant Molt-4 cell line became sensitive after being treated with TRAIL and a low dose of doxorubicin (0.1 micro M), but UCB mononuclear cells remained resistant. DR4 expression was increased when Jurkat cells were treated with TRAIL, and DR5 expression increased after exposing Molt-4 cells to TRAIL plus a low dose of doxorubicin for 24 h. The expression of DR4 and DR5 in UCB mononuclear cells was unchanged after treatment with TRAIL, a low-dose doxorubicin, or TRAIL plus a low dose of doxorubicin. In TRAIL-sensitive Jurkat cells, caspases 8, 9, 3, and 7 were activated by TRAIL treatment and activation of caspases was augmented by TRAIL plus a low dose of doxorubicin than TRAIL or a low dose of doxorubicin alone in Molt-4 cells. Experiments involving mixture of UCB mononuclear cells and Jurkat or Molt-4 cells showed a marked eradication of leukemia cells and the limiting dilution assay demonstrated an eradication rate of more than 4 logs after 24 h incubation with 100 ng/ml of TRAIL in Jurkat cells. In the case of Molt-4 cells, the eradication rate was about 3 logs when TRAIL was used in combination with a low dose of doxorubicin. No significant decrease in the number of granulocyte-macrophage colony-forming unit) (CFU-GM) colonies was detected when UCB mononuclear cells were treated with TRAIL in combination with a low dose of doxorubicin. These results suggest that TRAIL offers the possibility of being used as an ex vivo purging agent for autologous transplantation in hematologic malignancies.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia/patología , Glicoproteínas de Membrana/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Proteínas Reguladoras de la Apoptosis , Caspasas/efectos de los fármacos , Caspasas/metabolismo , Doxorrubicina/farmacología , Evaluación Preclínica de Medicamentos , Sangre Fetal/efectos de los fármacos , Trasplante de Células Madre Hematopoyéticas/normas , Humanos , Glicoproteínas de Membrana/uso terapéutico , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Receptores del Factor de Necrosis Tumoral/análisis , Ligando Inductor de Apoptosis Relacionado con TNF , Trasplante Autólogo , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/uso terapéutico
10.
Endocrinology ; 140(5): 2134-44, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10218964

RESUMEN

Insulin-like growth factor (IGF)-II plays an important role in fetal growth and development. IGFs are potent mitogens for a variety of cancer cells. A paracrine/autocrine role of IGF-II in the growth of breast and prostate cancer cells has been suggested. To test the role of IGF-II in cancer cell growth, hammerhead ribozymes targeted to human IGF-II RNA were constructed. Single (R)- and double (RR)-ribozymes were catalytically active in vitro whereas mutant ribozymes (M or MM) did not cleave IGF-II RNA. RR was more active than R. In human prostate cancer PC-3 cells, both R and RR similarly suppressed IGF-II messenger RNA (mRNA) levels (approximately 40%) compared with the level in parental or M-expressing PC-3 cells. Polymerase II and III promoter-driven R similarly suppressed IGF-II mRNA levels. Suppression of IGF-II mRNA levels by R was associated with suppression of IGF-II protein levels. R- (or RR-) expressing PC-3 cells did not grow under serum-starved conditions and showed prolonged doubling times in the presence of 10% FCS compared with those of parental or M-expressing cells. These results substantiated that IGF-II plays a critical role in prostate cancer cell growth.


Asunto(s)
Factor II del Crecimiento Similar a la Insulina/genética , Neoplasias de la Próstata/genética , ARN Catalítico/química , ARN Catalítico/metabolismo , ARN/metabolismo , Secuencia de Bases , Catálisis , División Celular , Expresión Génica , Humanos , Cinética , Masculino , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Regiones Promotoras Genéticas , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , ARN Polimerasa III/genética , ARN Mensajero/metabolismo , Relación Estructura-Actividad , Células Tumorales Cultivadas
11.
Gene ; 167(1-2): 59-62, 1995 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-8566812

RESUMEN

A unique DNA restriction-modification (R-M) system has been identified in the GM236 strain of Klebsiella pneumoniae using the newly isolated phage, SBS. The system was designated KpnBI. The gene (hsdRKpnBI) complementing the restriction activity of the KpnBI system was cloned in pBR322. The nucleotide sequence of the cloned DNA revealed one open reading frame (ORF) of 3035 bp. Analysis of the deduced amino-acid sequence shows seven helicase motifs which are common to the restriction (R) subunit of both type-I and type-III R-M systems. Computer analysis (Dendrogram) of the R polypeptide of KpnBI suggests a closer relationship to EcoR124/3I, a member of type-IC family, than to other representative type-I and type-III systems.


Asunto(s)
Enzimas de Restricción del ADN/genética , Enzimas de Restricción-Modificación del ADN/genética , Genes Bacterianos , Klebsiella pneumoniae/enzimología , Secuencia de Aminoácidos , Clonación Molecular , Klebsiella pneumoniae/genética , Datos de Secuencia Molecular , Filogenia , Mapeo Restrictivo
12.
Gene ; 255(2): 235-44, 2000 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-11024283

RESUMEN

We examined whether the antiviral effect of an HIV-1 Rev-binding aptamer [RBE(apt)] could be enhanced by a ribozyme directed against the HIV-1 env gene, and whether the antiviral activity was affected by different promoters. The efficacy of the aptamer and ribozyme DNAs was tested in HeLa cells co-transfected with the HIV-1 proviral clones, HXBDeltaBgl or pNL4-3, using transferrin-lipoplexes. The RBE(apt) and anti-env ribozyme genes were inserted into the pTZU6+27 plasmid, or constructed under the control of the human cytomegalovirus (CMV) or Rous sarcoma virus (RSV) promoters. The parental vector plasmids were used as controls. Co-transfection of the pTZU6+27 RBE(apt) plasmid with HXBDeltaBgl, or pNL4-3, at a weight ratio of 5:1, inhibited p24 production by 70 and 45%, respectively. The RSV RBE(apt) plasmid co-transfected with either HIV clone, at the same weight ratio, reduced viral production by 88%. The addition of the anti-env ribozyme to the RSV RBE(apt) did not enhance its antiviral activity. When the constructs were under the control of the CMV promoter, the expression of the HIV plasmids was very low and was independent of the presence of the RBE(apt). Thus, the effect of the RBE(apt) was strongly dependent on the promoter of the tested construct. The anti-HIV activity of the CMV RBE(apt) construct was non-specific, because co-transfection with either pCMV. SPORT-betagal or pCMVlacZ significantly suppressed HIV production from the HIV proviral clones. The reduction in p24 could not be attributed to the non-specific toxicity of the transfection procedure. Transfection of acutely HIV-infected HeLa-CD4 cells with pCMV.SPORT-betagal reduced the p24 level by 35%, while the expression of the U6 RBE(apt) did not affect p24 production. The suppression of HIV production from the HIV proviral clones by the CMV promoter constructs in the co-transfection assays may be explained by competition for transcription factors (TFs) between HIV and CMV promoters. This observation points to the potential for misleading results in co-transfections involving CMV constructs and HIV.


Asunto(s)
Citomegalovirus/genética , Productos del Gen rev/metabolismo , Oligonucleótidos/metabolismo , Regiones Promotoras Genéticas/genética , Replicación Viral/genética , Fármacos Anti-VIH/metabolismo , Línea Celular , ADN Recombinante , Regulación de la Expresión Génica , Productos del Gen env/metabolismo , Proteína p24 del Núcleo del VIH/genética , Proteína p24 del Núcleo del VIH/metabolismo , VIH-1/genética , VIH-1/metabolismo , Células HeLa , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Oligonucleótidos/genética , Plásmidos/genética , Unión Proteica , ARN Catalítico/genética , ARN Catalítico/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Virus 40 de los Simios/genética , Transfección , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismo , Productos del Gen rev del Virus de la Inmunodeficiencia Humana
13.
Gene ; 165(1): 31-8, 1995 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-7489912

RESUMEN

Arbitrarily primed polymerase chain reactions (AP-PCR) were used to amplify polymorphic DNA fragments from the genomes of a variety of geographic isolates of Leishmania donovani (Ld). From the latter, five polymorphic DNA fragments were cloned and sequence analysis identified 15 unique clones. Northern blot analysis showed that 13 of the 15 clones hybridized to transcribed RNAs isolated from Ld. Eight of these 13 AP-PCR clones specifically hybridized to Ld RNAs that were differentially expressed in promastigote and 'amastigote' cells. Comparative Northern analysis of four differentially expressed AP-PCR clones indicated that two clones, LdS-14-14 and LdI-9-7, were expressed in Ld and several other Leishmania species. However, RNAs corresponding to two other AP-PCR clones, LdE-6-1 and LdI-9-5, were detected only in members of the Ld complex, and not in L. major (Lm) or L. tropica (Lt). Comparative Southern blot analysis of the LdS-14-14 locus revealed numerous restriction-fragment length polymorphisms (RFLP) distinguishing Lm and Lt from the Ld isolates and L. infantum. However, the LdS-14-14 loci were mapped to similar-sized chromosomes observed among all Old World Leishmania species tested, indicating that localized nucleotide divergence, not chromosomal rearrangement, was responsible for altered Southern blot patterns. These results demonstrate that AP-PCR is a very useful method for identifying expressed gene sequences in organisms of relatively low-complexity genomes. Interestingly, the majority of these sequences identified in this study correspond to differentially expressed genes.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Genes Protozoarios , Leishmania donovani/genética , Animales , Secuencia de Bases , Mapeo Cromosómico , Expresión Génica , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa
14.
FEBS Lett ; 423(2): 235-8, 1998 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-9512364

RESUMEN

The transactivation potential of Nm23-H1, a homolog of c-myc transcription factor Nm23-H2/PuF was assessed in yeast as a fusion protein with the DNA binding domains (DBDs) of GAL4 and LexA. The C-terminal half of Nm23-H1 exhibited strong transactivation of the reporter genes, LacZ and Leu2 carrying GAL4 and LexA upstream activating sequences (UASs), whereas the full-length Nm23-H1 and its N-terminal did not. Similar results were also obtained with Nm23-H2/PuF transactivating the reporter genes only by the C-terminus fused to GAL4 and LexA DBDs. Hence, our results suggested a possible regulatory role of the N-termini of Nm23 isotypes upon transactivation.


Asunto(s)
Proteínas de Unión al GTP Monoméricas , Nucleósido-Difosfato Quinasa , Proteínas de Saccharomyces cerevisiae , Factores de Transcripción/genética , Activación Transcripcional/genética , Proteínas Bacterianas/genética , Proteínas de Unión al ADN , Regulación de la Expresión Génica , Genes Reporteros/genética , Humanos , Operón Lac/genética , Nucleósido Difosfato Quinasas NM23 , Proteínas/genética , ARN Largo no Codificante , Proteínas Recombinantes de Fusión/genética , Serina Endopeptidasas/genética , Factores de Transcripción/metabolismo , Transferasas , Proteínas Supresoras de Tumor
15.
Neurology ; 47(2): 331-9, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8757001

RESUMEN

Malformations of neuronal migration such as lissencephaly (agyria-pachygyria spectrum) are well-known causes of mental retardation and epilepsy that are often genetic. For example, isolated lissencephaly sequence and Miller-Dieker syndrome are caused by deletions involving a lissencephaly gene in chromosome 17p13.3, while many other malformation syndromes have autosomal recessive inheritance. In this paper, we review evidence supporting the existence of two distinct X-linked malformations of neuronal migration. X-linked lissencephaly and subcortical band heterotopia (XLIS) presents with sporadic or familial mental retardation and epilepsy. The brain malformation varies from classical lissencephaly, which is observed in males, to subcortical band heterotopia, which is observed primarily in females. The XLIS gene is located in chromosome Xq22.3 based on the breakpoint of an X-autosomal translocation. Bilateral periventricular nodular heterotopia (BPNH) usually presents with sporadic or familial epilepsy with normal intelligence, primarily in females, although we have evaluated two boys with BPNH and severe mental retardation. The gene for BPNH has been mapped to chromosome Xq28 based on linkage studies in multiplex families and observation of a subtle structural abnormality in one of the boys with BPNH and severe mental retardation.


Asunto(s)
Encéfalo/patología , Ligamiento Genético , Neuronas/patología , Cromosoma X , Adulto , Encéfalo/anomalías , Preescolar , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Linaje
16.
Mol Biochem Parasitol ; 81(1): 27-40, 1996 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-8892303

RESUMEN

Genome plasticity has been hypothesized to be a driving force behind parasite speciation. We have evaluated divergence in single and low-copy genes in terms of locus organization, chromosomal localization and gene expression in Leishmania infantum, L. major, L. tropica and three widely divergent geographic isolates of L. donovani. Seventeen genes of low to moderate copy number (1-4 copies/haploid genome) were analyzed to identify restriction fragment length polymorphisms (RFLPs) providing heritable markers distinguishing Old World (OW) leishmanias. These RFLP markers were conserved in parasite isolates from primary infections demonstrating their utility as diagnostic tools. The species designations established by RFLP analysis of field isolates was confirmed by use of monoclonal antibodies. All 17 genes were present in each OW leishmania analyzed except LSIP (A45), which was absent from L. infantum. The 17 genes were found to be distributed among 9 distinct chromosomes. However, in spite of variations in chromosome karyotypes among the various OW leishmanias, individual gene probes localized to a similar sized chromosome from each isolate. These observations coupled with a molecular tree derived from RFLP data suggest that the OW leishmanias comprise a monophyletic lineage, with species associated with cutaneous disease exhibiting the greatest level of divergence. Data from this study supports previous observations that species causing cutaneous and visceral disease have diverged primarily by nucleotide substitutions. Such nucleotide divergence may not only lead to changes in protein function and antigenicity, but may also alter gene regulation programs as exemplified by the finding that the LdI-9-5 and LdE-6-1 genes were expressed only in visceralizing leishmanias.


Asunto(s)
Genes Protozoarios , Leishmania/genética , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/parasitología , Animales , Anticuerpos Monoclonales , Secuencia de Bases , Secuencia Conservada , ADN Protozoario/genética , Evolución Molecular , Marcadores Genéticos , Variación Genética , Leishmania/inmunología , Leishmania/aislamiento & purificación , Leishmania donovani/genética , Leishmania infantum/genética , Leishmania major/genética , Leishmania tropica/genética , Datos de Secuencia Molecular , Familia de Multigenes , Polimorfismo de Longitud del Fragmento de Restricción , Especificidad de la Especie
17.
Mol Biochem Parasitol ; 81(1): 53-64, 1996 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-8892305

RESUMEN

Calreticulin has been implicated in multiple cell functions. Recently, we have shown that both human and simian calreticulin are RNA binding proteins and that their binding activity is due to phosphorylation. To demonstrate that the RNA binding property of calreticulin is an intrinsic part of this multi-functional molecule and is evolutionarily conserved, we isolated and characterized the calreticulin gene from the unicellular parasite, Leishmania donovani. Amino acid sequence homology between human and Leishmania calreticulin (L. d. cal) is limited, but like the human homologue, L. d. cal binds Ca+2, can be phosphorylated in vitro and binds certain RNA sequences in a phosphorylation-dependent manner. Unlike human calreticulin, L. d. cal is glycosylated and its binding to endogenous Leishmania RNA is phosphorylation-independent. The binding of L. d. cal to Leishmania RNA suggests that the RNA binding activity of calreticulin has remained evolutionarily conserved.


Asunto(s)
Proteínas de Unión al Calcio/genética , Genes Protozoarios , Leishmania donovani/genética , Proteínas Protozoarias/genética , Proteínas de Unión al ARN/genética , Ribonucleoproteínas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión/genética , Proteínas de Unión al Calcio/metabolismo , Calreticulina , Secuencia Conservada , Cartilla de ADN/genética , Evolución Molecular , Glicoproteínas/genética , Glicoproteínas/metabolismo , Humanos , Leishmania donovani/metabolismo , Datos de Secuencia Molecular , Fosforilación , Proteínas Protozoarias/metabolismo , Proteínas de Unión al ARN/metabolismo , Ribonucleoproteínas/metabolismo , Homología de Secuencia de Aminoácido
18.
J Biochem ; 118(4): 796-801, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8576095

RESUMEN

A novel type of sulfotransferase, arylsulfate sulfotransferase [EC 2.8.2.22], was purified to homogeneity from Haemophilus K-12, a mouse intestinal bacterium. The purified enzyme (M(r) 290,000) is composed of four subunits (M(r) 70,000). The best donor substrate was 4-methylumbelliferyl sulfate, followed by beta-naphthyl sulfate, p-nitrophenyl sulfate (PNS), and alpha-naphthyl sulfate. The best acceptor substrate was alpha-naphthol, followed by phenol and resorcinol. The apparent Km for PNS using phenol as an acceptor and that for phenol and resorcinol. The apparent Km for PNS using phenol as an acceptor and that for phenol using PNS as a donor substrate were determined to be 0.095 and 0.71 mM, respectively. One of the reaction products, p-nitrophenol inhibited the enzyme noncompetitively with respect to PNS, but competitively with respect to alpha-naphthol. The Ki values of PNP for PNS and alpha-naphthol were 0.89 and 0.12 mM, respectively. The other reaction product, alpha-naphthyl sulfate, inhibited the enzyme competitively with respect to PNS, but non-competitively with respect to alpha-naphthol. The Ki values of alpha-naphthyl sulfate for PNS and for alpha-naphthol were 2.72 and 1.7 mM. These results suggest that the sulfate transfer reaction proceeds according to a ping pong bi bi mechanism.


Asunto(s)
Arilsulfotransferasa/aislamiento & purificación , Haemophilus/enzimología , Intestinos/microbiología , Animales , Arilsulfotransferasa/metabolismo , Unión Competitiva , Ratones , Especificidad por Sustrato
19.
Cardiol Clin ; 9(3): 523-34, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1913731

RESUMEN

The prevention, management, and prognosis of patients with transient ischemic attack or stroke caused by extracranial cerebrovascular disease depend on the underlying pathophysiologic mechanisms involved. Atherosclerotic vascular disease is the predominant pathophysiologic mechanism. Management of this entity remains controversial and should be individualized. Recent data have clearly confirmed that carotid endarterectomy is better than medical therapy. Patients with a critically tight carotid stenosis appropriate in location to their symptoms are considered for carotid endarterectomy. This procedure should be performed only in the setting of excellent neuroradiologic support and surgical expertise, however, with a cumulative complication risk of less than 3%. Intimal dissection appears to be associated with a good prognosis with or without treatment. However, patients with symptoms should receive short-term therapy with antiplatelet or anticoagulant agents to prevent distal embolization. Corticosteroids are the drugs of choice for treatment of patients with extracranial arteritis. The presence of fibromuscular dysplasia in the cerebrovascular system has not proved to be a definitive risk for stroke or transient ischemic attack.


Asunto(s)
Enfermedades de las Arterias Carótidas/complicaciones , Arteria Subclavia , Arteria Vertebral , Anciano , Arteriosclerosis/complicaciones , Arteritis/complicaciones , Enfermedades de las Arterias Carótidas/etiología , Trastornos Cerebrovasculares/etiología , Displasia Fibromuscular/complicaciones , Humanos , Ataque Isquémico Transitorio/etiología , Persona de Mediana Edad , Enfermedades Vasculares/complicaciones , Enfermedades Vasculares/diagnóstico
20.
J Drug Target ; 5(4): 247-59, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9713975

RESUMEN

We examined whether HIV-1 gene expression could be inhibited by the anti-HIV Rev-binding aptamer [RBE(apt)], and whether the antiviral effect of the aptamer could be enhanced by a ribozyme directed against the HIV-1 env gene. Since cationic liposomes are relatively safe and non-immunogenic for in vivo gene delivery, we tested the effectiveness of the aptamer and ribozyme DNAs in HeLa cells, using Lipofectin reagent in a transient transfection assay. To increase the transfection efficiency, lipofectin was mixed with transferrin before subsequent addition of DNA. Co-transfection of HeLa cells with the RBE(apt) and the proviral HIV clone, HXBdeltaBgl, resulted in inhibition of virus production. Specific inhibition of viral p24 production following co-transfection of the RBE(apt) and HIV proviral DNAs was observed. These data provide strong support for the use of in vitro evolved ligands as potential anti-HIV agents. The addition of the anti-env ribozyme to the aptamer construct did not further enhance the antiviral activity, suggesting either that we had reached the limits of inhibition in this assay, or that the ribozyme was not able to access its target site with Rev bound to the RBE aptamer. The observed inhibition of p24 production could not be attributed to the non-specific toxicity of the transfection procedure, because no difference in viability was observed between the RBE(apt)- and the vector control-treated cells. All of the aptamer-ribozyme constructs as well as the RBE(apt) were similarly effective.


Asunto(s)
Productos del Gen rev/metabolismo , VIH-1/genética , ARN Catalítico/genética , Receptores del VIH/metabolismo , Secuencia de Bases , Cationes , Portadores de Fármacos , Regulación Viral de la Expresión Génica , Productos del Gen env/genética , Productos del Gen rev/genética , Proteína p24 del Núcleo del VIH/biosíntesis , VIH-1/fisiología , Células HeLa , Humanos , Ligandos , Liposomas , Conformación de Ácido Nucleico , Plásmidos , ARN Catalítico/química , Transfección , Replicación Viral/genética , Productos del Gen rev del Virus de la Inmunodeficiencia Humana
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