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1.
Biochim Biophys Acta ; 1833(5): 1006-16, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23328083

RESUMEN

Sphingosine kinase 1 (SPHK1) overexpression in malignant cells has been reported. Mouse Friend cells showed higher SPHK1 but not SPHK2 expression compared with other mouse cell lines. A Sphk1 promoter analysis demonstrated the region between -53bp and the first exon as the minimal promoter. Further promoter truncation revealed the importance of a MYB-binding site. EMSA using this region as the probe demonstrated one band containing c-MYB protein, and its intensity decreased during erythroid differentiation with hexamethylane bisacetamide (HMBA), a potent inducer of erythroid differentiation of Friend cells. ChIP assay also revealed in vivo binding of c-MYB. c-MYB overexpression and siRNA for c-Myb affected SPHK1 expression, confirming the important regulatory role of c-MYB in SPHK1 expression. HMBA reduced c-MYB expression rapidly. Induced differentiation by HMBA caused a marked and rapid reduction of SPHK1 mRNA, protein and enzyme activity leading to the rapid decrease of cellular sphingosine 1-phosphate level. Moreover, terminally differentiated cells did not resume SPHK1 expression. Compared with original Friend cells, stable overexpression of wild-type SPHK1 showed higher cell proliferation, resistance to cell death by serum depletion. Interestingly, HMBA-induced differentiation of these cells was delayed but not completely suppressed. In contrast, SPHK inhibitor and its siRNA inhibited cell growth and enhanced HMBA-induced differentiation significantly, suggesting that SPHK1 delayed HMBA-induced differentiation by its cell proliferation-promoting activity. Effects of pertussis toxin, a G-protein-coupled receptor inhibitor, and S1P receptor antagonist on Friend cell growth and differentiation were negligible, suggesting the importance of the intracellular SPHK1/S1P signaling in Friend cells.


Asunto(s)
Diferenciación Celular/genética , Fosfotransferasas (Aceptor de Grupo Alcohol) , Proteínas Proto-Oncogénicas c-myb , Receptores de Lisoesfingolípidos , Animales , Línea Celular , Regulación hacia Abajo , Humanos , Ratones , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-myb/genética , Proteínas Proto-Oncogénicas c-myb/metabolismo , ARN Mensajero/genética , ARN Interferente Pequeño , Receptores de Lisoesfingolípidos/antagonistas & inhibidores , Receptores de Lisoesfingolípidos/genética , Receptores de Lisoesfingolípidos/metabolismo , Transducción de Señal
2.
Leukemia ; 23(7): 1270-7, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19212333

RESUMEN

Although oncogenic functions and the clinical significance of Wilms tumor 1 (WT1) have been extensively studied in acute leukemia, the regulatory mechanism of its transcription still remains to be determined. We found a significant correlation among the amounts of WT1, GATA-1 and GATA-2 mRNAs from leukemia and solid tumor cell lines. Overexpression and small interfering RNA (siRNA) transfection experiments of GATA-1 and GATA-2 showed that these GATA transcription factors could induce WT1 expression. Promoter analysis showed that the 5' promoter did not explain the different WT1 mRNA levels between cell lines. The 3' enhancer, especially the distal sites out of six putative GATA binding sites located within the region, but not the intron 3 enhancer, were essential for the WT1 mRNA level. Electrophoretic mobility shift assay (EMSA) showed both GATA-1 and GATA-2 bound to these GATA sites. Besides acute leukemia cell lines, solid tumor cell lines including, TYK-nu-cPr also showed a high level of WT1 mRNA. We showed that GATA-2 expression is a determinant of WT1 mRNA expression in both TYK-nu-cPr cells and HL60 cells without GATA-1 expression. Taken together, these results suggest that GATA-1 and/or GATA-2 binding to a GATA site of the 3' enhancer of WT1 played an important role in WT1 gene expression.


Asunto(s)
Elementos de Facilitación Genéticos , Factor de Transcripción GATA1/metabolismo , Factor de Transcripción GATA2/metabolismo , Genes del Tumor de Wilms , Leucemia/genética , Transcripción Genética , Enfermedad Aguda , Secuencia de Bases , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Cartilla de ADN , Ensayo de Cambio de Movilidad Electroforética , Factor de Transcripción GATA1/genética , Factor de Transcripción GATA2/genética , Humanos , Intrones , Leucemia/patología , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Interferente Pequeño , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
3.
Oncogene ; 27(46): 6023-33, 2008 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-18574469

RESUMEN

Sphingosine kinase 1 (SPHK1) is overexpressed in solid tumors and leukemia. However, the mechanism of SPHK1 overexpression by oncogenes has not been defined. We found that v-Src-transformed NIH3T3 cells showed a high SPHK1 mRNA, SPHK1 protein and SPHK enzyme activity. siRNA of SPHK1 inhibited the growth of v-Src-NIH3T3, suggesting the involvement of SPHK1 in v-Src-induced oncogenesis. v-Src-NIH3T3 showed activations of protein kinase C-alpha, signal transducers and activators of transcription 3 and c-Jun NH(2)-terminal kinase. Their inhibition suppressed SPHK1 expression in v-Src-NIH3T3, whereas their overexpression increased SPHK1 mRNA in NIH3T3. Unexpectedly, the nuclear run-on assay and the promoter analysis using 5'-promoter region of mouse SPHK1 did not show any significant difference between mock- and v-Src-NIH3T3. Furthermore, the half-life of SPHK1 mRNA in mock-NIH3T3 was nearly 15 min, whereas that of v-Src-NIH3T3 was much longer. Examination of two AU-rich region-binding proteins, AUF1 and HuR, that regulate mRNA decay reciprocally, showed decreased total AUF1 protein associated with increased tyrosine-phosphorylated form and increased serine-phosphorylated HuR protein in v-Src-NIH3T3. Modulation of AUF1 and HuR by their overexpression or siRNA revealed that SPHK1 mRNA in v-Src- and mock-NIH3T3 was regulated reciprocally by these factors. Our results showed, for the first time, a novel mechanism of v-Src-induced SPHK1 overexpression.


Asunto(s)
Proteína Oncogénica pp60(v-src)/fisiología , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Estabilidad del ARN/fisiología , Proteínas de Unión al ARN/fisiología , Animales , Antígenos de Superficie/genética , Antígenos de Superficie/metabolismo , Antígenos de Superficie/fisiología , Línea Celular Transformada , Proliferación Celular/efectos de los fármacos , Proteínas ELAV , Proteína 1 Similar a ELAV , Regulación Enzimológica de la Expresión Génica , Semivida , Ribonucleoproteína Nuclear Heterogénea D0 , Ribonucleoproteína Heterogénea-Nuclear Grupo D/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo D/metabolismo , Ribonucleoproteína Heterogénea-Nuclear Grupo D/fisiología , Ratones , Modelos Biológicos , Células 3T3 NIH , Proteína Oncogénica pp60(v-src)/antagonistas & inhibidores , Proteína Oncogénica pp60(v-src)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Estabilidad del ARN/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/farmacología , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Secuencias Reguladoras de Ácido Ribonucleico/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología , Transfección
4.
Int J Hematol ; 87(3): 266-75, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18283525

RESUMEN

We recently reported increased sphingosine kinase 1 (SPHK1) and decreased neutral sphingomyelinase 2 (NSMase2) gene expression in myelodysplastic syndromes and acute leukemia. This alteration is supposed to change the cellular sphingolipid metabolites; however, positive correlations were observed between daunorubicin (DA)-IC50 and the SPHK1 message but not between DA-IC50 and NSMase2 messages, when 16 different leukemia cell lines were used to analyze the relationship between gene expressions and chemosensitivity against DA. Using two cell lines with either the highest or lowest SPHK1 expression, cellular ceramides and sphingosine 1-phosphate (S1P) were quantified by liquid chromatography/mass spectrometry. Increased ceramide was observed in DA-sensitive, but not in DA-resistant cell lines treated with low doses of DA. Upon DA treatment, S1P decreased more in the sensitive cell lines than in resistant cell lines. A SPHK inhibitor recovered the DA sensitivity of DA-resistant cells. The modulation of SPHK1 gene expression by either overexpression or using siRNA affected the DA sensitivity of representative cell lines. Results clearly show that SPHK1 is both a good marker to predict the DA sensitivity of leukemia cells and a potential therapeutic target for leukemia with high SPHK1 expression, and suggest that the sphingolipid rheostat plays a significant role in DA-induced cytotoxicity.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Daunorrubicina/farmacología , Resistencia a Antineoplásicos/fisiología , Leucemia/tratamiento farmacológico , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Biomarcadores/sangre , Línea Celular Tumoral , Perfilación de la Expresión Génica , Humanos , Lisofosfolípidos/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/efectos de los fármacos , Esfingosina/análogos & derivados , Esfingosina/metabolismo
5.
Oncogene ; 26(12): 1802-10, 2007 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-16964281

RESUMEN

It was reported that short interfering RNA (siRNA) of EWS/Fli-1 downregulated phospholipase D (PLD)2 in Ewing's sarcoma (EWS) cell line, suggesting that PLD2 is the target of aberrant transcription factor, EWS/Fli-1. Here, we further investigated the regulation of PLD2 gene expression by EWS/Fli-1 and Fli-1 in another EWS cell line, and also in EWS/Fli-1- or Fli-1-transfected cell line. EWS/Fli-1- or Fli-1-overexpressed cells showed higher PLD2 but not PLD1 protein expression and enhanced cell proliferation as compared to mock transfectant. The treatment of these cells with 1-butanol or siRNA of PLD2 inhibited cell growth, suggesting the pivotal role of PLD in cell growth promotion. PLD2 but not PLD1 mRNA level was also increased in EWS/Fli-1 or Fli-1-transfectants. After determining the transcription initiation points, we cloned the 5' promoter of both PLD1 and PLD2 and analysed promoter activities. Results showed that EWS/Fli-1 and Fli-1 increase PLD2 gene expression by binding to an erythroblast transformation-specific domain (-126 to -120 bp from the transcription initiation site) of PLD2 promoter, which is the minimal and most powerful region. Electrophoresis mobility shift assay using truncated proteins showed that both DNA-binding domain and trans-activating domain were necessary for the enhanced gene expression of PLD2.


Asunto(s)
Proteínas de Microfilamentos/fisiología , Proteínas de Fusión Oncogénica/fisiología , Fosfolipasa D/genética , Regiones Promotoras Genéticas , Proteína Proto-Oncogénica c-fli-1/fisiología , Receptores Citoplasmáticos y Nucleares/fisiología , Secuencia de Bases , Línea Celular , Cartilla de ADN , Ensayo de Cambio de Movilidad Electroforética , Humanos , Inmunoprecipitación , Proteínas de Microfilamentos/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Unión Proteica , Proteína Proto-Oncogénica c-fli-1/metabolismo , Proteína EWS de Unión a ARN , Receptores Citoplasmáticos y Nucleares/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transactivadores , Transfección
7.
J Neurochem ; 95(4): 940-9, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16135093

RESUMEN

Sphingosine kinase (SPHK) is known to exert an anti-apoptic role in various cells and cell lines. We previously reported that human brain is rich in SPHK1 (Murate et al. 2001). After showing a high expression of SPHK1 in rat brain, we examined the gene expression mechanism using nerve growth factor (NGF)-stimulated rat PC12 cells. With RT-PCR, we found that both rat brain and PC12 utilized exon 1d mostly out of eight untranslated first exons. NGF induced an increase in SPHK enzyme activity and protein about double those in PC12 cells, and NGF-induced SPHK1 mRNA was three times higher than in the control. The minimal 5' promoter was determined, and TrkA specific inhibitor K252a inhibited the NGF-induced promoter activity of SPHK1. The truncation or mutation of putative transcription factor-binding motifs revealed that one specificity protein 1 (Sp1) binding motif of the 5' region of exon 1d is prerequisite. Electrophoresis mobility shift assay confirmed the promoter analysis, indicating increased Sp1 protein binding to this motif after NGF treatment. Chromatin immunoprecipitation assay also showed the binding of Sp1 and the promoter region in vivo. These results suggest the signal transduction pathway from NGF receptor TrkA to transcription factor Sp1 protein binding to the promoter Sp1-like motif in NGF-induced rat SPHK1 gene expression.


Asunto(s)
Regulación de la Expresión Génica/fisiología , Expresión Génica/efectos de los fármacos , Factor de Crecimiento Nervioso/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Factor de Transcripción Sp1/fisiología , Animales , Western Blotting/métodos , Encéfalo/metabolismo , Carbazoles/farmacología , Inmunoprecipitación de Cromatina/métodos , Ensayo de Cambio de Movilidad Electroforética/métodos , Inhibidores Enzimáticos/farmacología , Exones , Expresión Génica/fisiología , Regulación de la Expresión Génica/efectos de los fármacos , Alcaloides Indólicos , Luciferasas/metabolismo , Mutagénesis/fisiología , Células PC12 , Feocromocitoma/patología , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Regiones Promotoras Genéticas/fisiología , Unión Proteica/efectos de los fármacos , Unión Proteica/fisiología , ARN Mensajero/metabolismo , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Transfección/métodos
8.
Aliment Pharmacol Ther ; 21 Suppl 2: 2-9, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15943840

RESUMEN

BACKGROUND: The epidemiology and pathophysiology of non-erosive gastro-oesophageal reflux disease differs from erosive gastro-oesophageal reflux disease. There is a possibility that non-erosive gastro-oesophageal reflux disease treatment requires a different regimen/approach but it is not yet acknowledged. AIM: To investigate the efficacy of famotidine and omeprazole in the treatment of gastro-oesophageal reflux disease, especially non-erosive gastro-oesophageal reflux disease. PATIENTS AND METHODS: A randomized, open-label trial was conducted. Fifty-four gastro-oesophageal reflux disease patients were assigned to treatment with famotidine at a dosage of 20 mg twice daily; or omeprazole, 20 mg once daily, for a period of 8 weeks. The Short Form-36 Health Survey and Gastrointestinal Symptom Rating Scale administered at baseline and after 8 weeks of treatment as well as a symptom questionnaire were conducted daily. RESULTS: Short Form-36 revealed that gastro-oesophageal reflux disease has severe impact on health-related quality of life. Thirty-nine subjects (77%) were endoscopically diagnosed as non-erosive gastro-oesophageal reflux disease. The mean Gastrointestinal Symptom Rating Scale abdominal pain, and indigestion score of non-erosive gastro-oesophageal reflux disease significantly improved in famotidine-treated patients (P < 0.05), but not in the omeprazole. There was no significant change regarding improved heartburn symptoms of non-erosive gastro-oesophageal reflux disease between treatments in the daytime or night-time. CONCLUSION: Famotidine and omeprazole were both effective in improving symptoms of gastro-oesophageal reflux disease, particularly non-erosive gastro-oesophageal reflux disease.


Asunto(s)
Antiulcerosos/administración & dosificación , Famotidina/administración & dosificación , Reflujo Gastroesofágico/tratamiento farmacológico , Omeprazol/administración & dosificación , Análisis de Varianza , Quimioterapia Combinada , Femenino , Pirosis/etiología , Humanos , Masculino , Persona de Mediana Edad , Calidad de Vida , Encuestas y Cuestionarios , Resultado del Tratamiento
9.
Int J Paediatr Dent ; 12(6): 433-7, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12452986

RESUMEN

A case of dense bone island in a girl aged 10 years, 1 month old is presented. The lesion was asymptomatic and was an incidental finding on a radiograph taken for another purpose. Nine months after the patient's first visit, an obvious inclination of adjacent teeth was identified. The size and density of the lesion had increased by 10 and 7%, respectively. As the patient was still in adolescence, the lesion may increase in size and density, potentially resulting in further problems such as increased inclination of the adjacent teeth. In addition, the presence of the lesion may complicate any future orthodontic treatment. The lesion should be kept under observation until its growth ceases.


Asunto(s)
Enfermedades Mandibulares/diagnóstico por imagen , Osteosclerosis/diagnóstico por imagen , Densidad Ósea , Niño , Femenino , Humanos , Maloclusión/etiología , Enfermedades Mandibulares/complicaciones , Osteosclerosis/complicaciones , Radiografía
10.
J Dent Res ; 81(6): 376-9, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12097427

RESUMEN

A blood isolate of Streptococcus mutans strain TW871 shows relatively low homology with MT8148, a reference oral isolate strain, and lacks the serotype-specific polysaccharide antigen, suggesting that other cell-surface structures correlate with cariogenicity. We compared cariogenicity of TW871 with MT8148 (serotype c) and blood isolate TW964 (serotype f) in rats. Strain TW871 showed significantly lower cariogenicity than MT8148 or TW964 and expressed significantly lower sucrose-independent cellular adhesion to saliva-coated hydroxyapatite and dextran-binding activity than strain MT8148. Strains TW871 and TW964 showed a defect in the gbpA gene by Southern hybridization analysis, while sequencing analysis revealed gbpC variation in TW871. These results suggest that variation in GbpC may alter cellular adherence properties and can be correlated with the cariogenicity of S. mutans in this strain.


Asunto(s)
Adhesión Bacteriana/genética , Proteínas Bacterianas/genética , Proteínas Portadoras/genética , Caries Dental/microbiología , Glucanos/metabolismo , Streptococcus mutans/genética , Streptococcus mutans/patogenicidad , Secuencia de Aminoácidos , Análisis de Varianza , Animales , Bacteriemia/sangre , Proteínas Bacterianas/fisiología , Southern Blotting , Western Blotting , Proteínas Portadoras/fisiología , Niño , Durapatita/metabolismo , Endocarditis Bacteriana/sangre , Variación Genética , Humanos , Lectinas , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Ratas , Ratas Sprague-Dawley , Análisis de Secuencia de ADN , Especificidad de la Especie , Organismos Libres de Patógenos Específicos , Streptococcus mutans/clasificación , Streptococcus mutans/inmunología , Virulencia
11.
J Clin Pediatr Dent ; 26(3): 275-7, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-11990051

RESUMEN

The primary molars received calcium hydroxide pulpotomy with or without the electrocoagulation procedure. Teeth were evaluated clinically and radiographically at 6, 12, and 24 months after treatment. There was no statistically significant difference in success rate between calcium hydroxide pulpotomies, with and without the electrocoagulation procedure, either clinically or radiographically. These results indicate that a pulpotomy with calcium hydroxide is an effective treatment for cariously exposed pulp in primary molars and electrocoagulation can extend its indication.


Asunto(s)
Hidróxido de Calcio/uso terapéutico , Caries Dental/terapia , Recubrimiento de la Pulpa Dental , Electrocoagulación , Pulpotomía/métodos , Diente Primario/patología , Niño , Preescolar , Coronas , Exposición de la Pulpa Dental/terapia , Dentina Secundaria/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Cementos de Ionómero Vítreo , Técnicas Hemostáticas , Humanos , Masculino , Diente Molar/diagnóstico por imagen , Diente Molar/patología , Radiografía , Estadística como Asunto , Resorción Dentaria/diagnóstico por imagen , Resorción Dentaria/etiología , Diente Primario/diagnóstico por imagen , Resultado del Tratamiento
12.
Eur J Oral Sci ; 109(5): 330-4, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11695754

RESUMEN

Four out of 522 streptococcal isolates from the peripheral blood of patients with bacteremia exhibited typical properties of Streptococcus mutans in terms of sucrose-dependent adhesion, expression of glucosyltransferases, fermentation profiles of sugars, the presence of surface protein antigen, and DNA-DNA hybridization. Two strains were determined as serotype f and e by immunodiffusion, whereas the other two isolates did not react with the specific antiserum to S. mutans serotype c. e. or f of the eight different serotypes of mutans streptococci. The latter two untypable isolates, however, expressed a new antigenic determinant that was different from serotype c/e/f specificity as revealed by immunodiffusion. Analysis of the cell wall polysaccharides revealed very low contents of glucose in the untypable isolates. Furthermore, Southern blot analysis demonstrated that the untypable strains lacked at least one gene corresponding to a glucose-adding enzyme. These results indicate that the serologically untypable nature is due to the loss of glucosidic residue from the serotype-specific polysaccharide antigens of S. mutans.


Asunto(s)
Bacteriemia/microbiología , Infecciones Estreptocócicas/microbiología , Streptococcus mutans/clasificación , Antígenos Bacterianos/análisis , Antígenos de Superficie/análisis , Adhesión Bacteriana , Fenómenos Bioquímicos , Bioquímica , Southern Blotting , Pared Celular/química , ADN Bacteriano/genética , Ensayo de Inmunoadsorción Enzimática , Epítopos/análisis , Epítopos/clasificación , Femenino , Fermentación , Genes Bacterianos/genética , Glucosa/análisis , Glucosa/genética , Glucosiltransferasas/análisis , Humanos , Inmunodifusión , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Fenotipo , Polisacáridos Bacterianos/análisis , Polisacáridos Bacterianos/genética , Ramnosa/análisis , Ramnosa/genética , Serotipificación , Streptococcus mutans/enzimología , Streptococcus mutans/genética , Sacarosa/metabolismo
13.
J Dent Res ; 80(7): 1672-7, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11597030

RESUMEN

Streptococcus mutans produces 3 types of glucosyltransferase (GTF), whose cooperative action is considered to be essential for its cellular adherence to the tooth surface. However, the precise mechanisms for synthesizing adhesive glucans and the specific roles of each GTF in cellular adherence to smooth surfaces have not been elucidated. In the present study, seven types of isogenic mutants of S. mutans MT8148 lacking GTFB, GTFC, and/or GTFD activities were constructed by inactivation of the genes encoding GTFB, GTFC, and/or GTFD. Furthermore, recombinant GTFB, GTFC, and GTFD were prepared from Escherichia coli cells harboring recombinant plasmids containing each of the gtf genes. Using these GTF-deficient mutants and rGTFs, we reconstituted sucrose-dependent adherence of S. mutans resting cells and examined the role of each GTF in vitro. The highest level of sucrose-dependent adherence was found at the ratio of 20 rGTFB:1 rGTFC:4 rGTFD in both the resting cells of GTF-deficient mutants and insoluble glucan synthesized by rGTFs. Moreover, when rGTFC and rGTFD were both present at concentrations of 1.5 mU and 6 mU, respectively, the insoluble glucan synthesized from sucrose by the rGTFs showed a high level of adhesiveness to smooth surfaces, even without rGTFB. These results suggest that the presence of all three GTFs at the optimum ratio is necessary for sucrose-dependent adherence of S. mutans, and that GTFC and GTFD may play significant roles in the synthesis of adhesive and insoluble glucan from sucrose.


Asunto(s)
Adhesión Bacteriana/fisiología , Proteínas Bacterianas/metabolismo , Glucosiltransferasas/metabolismo , Streptococcus mutans/enzimología , Glucanos/biosíntesis , Glucosiltransferasas/genética , Mutagénesis Sitio-Dirigida , Proteínas Recombinantes/metabolismo , Sacarosa/metabolismo
14.
J Gastroenterol ; 36(8): 544-51, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11519833

RESUMEN

PURPOSE: An imbalance in helper T-cell type 1 (Th1) and type 2 (Th2) cytokines is suggested to play an important role in the pathogenesis of chronic viral infections, but this issue is not resolved in patients with hepatitis C virus (HCV) infection. The aim of this study was to clarify the relationship between the balance of Th1 and Th2 cytokines and liver damage. METHODS: We investigated cytokine levels in the peripheral blood and liver tissue of patients with chronic HCV infection (n = 59) by three different methods; we used flow cytometry to detect intracellular cytokines, and we measured cytokine titers in sera and in the supernatants of lymphocyte cultures with enzyme-linked immunosorbent assays (ELISAs). RESULTS: In both CD4+ and CD8+ cells, interferon (IFN) gamma-producing cell populations increased, while there was no difference in interleukin (IL)-10 production, indicating a shift to a Th1 cytokine profile with the progression of liver disease. With respect to the ratio of IFN-gamma to IL-10, a correlation was found in CD4+ cells between peripheral blood and liver tissue (r = 0.98; P = 0.0011). Th1 cytokine was predominant in intrahepatic CD4+ cells, while it was predominant in peripheral blood CD8+ cells. CONCLUSIONS: These findings indicate a correlation between dominant Th1 response and disease activity and progression. In addition, we suggest that intrahepatic CD4+ T cells play a pathogenetic role in the hepatic injury of HCV infection.


Asunto(s)
Hepatitis C Crónica/inmunología , Linfocinas/sangre , Células TH1/inmunología , Células Th2/inmunología , Anciano , Recuento de Linfocito CD4 , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Citometría de Flujo/métodos , Hepacivirus/inmunología , Hepatitis C Crónica/patología , Humanos , Interferón gamma/sangre , Interleucina-10/sangre , Masculino , Persona de Mediana Edad
15.
ASDC J Dent Child ; 68(1): 63-6, 32, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11324411

RESUMEN

Supernumerary teeth and hypodontia can be regarded as opposite developmental phenomena. An eight-year-old girl presented a concomitant occurrence of a supernumerary tooth and two congenitally missing teeth. The supernumerary tooth was found in the left maxillary incisor region, while the left second premolar in the maxilla and the left lateral incisor in the mandible were congenitally missing. The supernumerary tooth showed a similar color and morphology to those of the maxilla lateral incisor, and the lateral incisor on the mesial side was diagnosed as a supernumerary tooth from dental age, eruption time, and mesiodistal crown dimension. The supernumerary incisor was guided labially to cure an anterior cross-bite, and the lateral incisor, canine, and first premolar were guided distally to compensate for the space left by the congenitally missing left second premolar.


Asunto(s)
Anodoncia/diagnóstico por imagen , Diente Premolar/anomalías , Incisivo/anomalías , Diente Supernumerario/diagnóstico por imagen , Determinación de la Edad por los Dientes , Diente Premolar/diagnóstico por imagen , Niño , Femenino , Humanos , Incisivo/diagnóstico por imagen , Incisivo/patología , Maloclusión/terapia , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Odontometría , Corona del Diente/patología , Erupción Dental
16.
Int J Paediatr Dent ; 11(6): 452-5, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11759106

RESUMEN

A radicular cyst arising from the primary second molar and causing displacement of the permanent successor to the lower border of the mandible, with accompanying buccal expansion, was examined clinically and radiographically. Extraction of the primary molar and extirpation of the cyst led to uneventful healing. The primary molar had received pulp treatment with therapeutic agents approximately 1.5 years prior to the patient's first visit. The relationship between pulp treatment and rapid growth of the radicular cyst is discussed.


Asunto(s)
Enfermedades Mandibulares/etiología , Diente Molar/patología , Quiste Radicular/etiología , Tratamiento del Conducto Radicular/efectos adversos , Diente Primario/patología , Antiinfecciosos Locales/efectos adversos , Hidróxido de Calcio/efectos adversos , Niño , Humanos , Hidrocarburos Yodados/efectos adversos , Masculino , Radiografía Panorámica , Materiales de Obturación del Conducto Radicular/efectos adversos
17.
J Oral Pathol Med ; 29(9): 460-2, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11016689

RESUMEN

Craniometaphyseal dysplasia (CMD) is a very rare genetic disorder of bone remodeling caused by osteoclast dysfunction. The clinical and radiographical features of oral findings are presented in a sporadic case of CMD in a child (age 10 years, 7 months). An intraoral examination showed severe malocclusions, including anterior crossbite and deep bite. Furthermore, a radiographic examination showed increased radiopacity of the maxilla and mandibular bones due to hyperostosis and sclerosis of the jaw. There was no root resorption of the canines or molars in the primary dentition, although root formation of the permanent teeth was proceeding. Dental age was calculated to be approximately 1 year, 4 months younger than his chronological age. The eruption speed of the permanent lateral incisors after the gingival emergence was shown to be within normal values, and we discuss whether the canines and premolars in the permanent dentition could erupt or not.


Asunto(s)
Anomalías Craneofaciales/fisiopatología , Erupción Dental , Niño , Anomalías Craneofaciales/complicaciones , Humanos , Hiperostosis/etiología , Enfermedades Maxilomandibulares/etiología , Masculino , Maloclusión/etiología , Resorción Radicular , Esclerosis/etiología , Exfoliación Dental
18.
Gene ; 256(1-2): 1-11, 2000 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-11054529

RESUMEN

We isolated the full-length human ameloblastin (AMBN) cDNA clone using reverse transcription-polymerase chain reaction (RT-PCR) methods. Sequence analysis of the AMBN cDNA revealed an open reading frame of 1341bp encoding a 447-amino-acid protein. Comparison with pig, cattle, rat, and mouse AMBN sequences showed a high amino acid sequence similarity and led to the identification of a novel 78bp (26 amino acids) insert resulting from internal sequence duplication. By DNA analysis of a human genomic clones, the AMBN gene was shown to consist of 13 exons and a novel 78bp segment, which proved to comprise two small exons. Human ameloblastomas express AMBN transcripts that contain some mutations.


Asunto(s)
Proteínas del Esmalte Dental/genética , Genes/genética , Ameloblastoma/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN/química , ADN/genética , ADN Complementario/química , ADN Complementario/genética , Exones , Regulación Neoplásica de la Expresión Génica , Humanos , Intrones , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico
19.
J Periodontal Res ; 35(5): 301-9, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11005158

RESUMEN

The present immunohistochemical study was designed to investigate the alteration in the expression level of calbindin D28k in the periodontal ligament of the rat molar in response to changes in occlusal force to clarify the physiological role(s) of this protein in the ligament. In normal periodontal ligament of the lower first molar, immunoreactivity for calbindin D28k was found in the spindle-shaped cells, presumably fibroblasts, at the alveolar portion of the ligament at the distal side of the mesial root and mesial side of the distal root. Following the overload of occlusal force to the upper first molar by bite-raising, the number and immunoreactivity of the positive cells in the periodontal ligament of the lower first molar increased gradually. A more significant increase was detected at 7 d following the bite-raising compared to the normal animals. When occlusal force was removed by the extraction of the upper first molar, the expression level of calbindin D28k in the periodontal ligament of the lower first molar rapidly decreased, however a subsequent gradual increase was recognized. Statistical analysis of the spatial immunoreactivity of calbindin D28k in the periodontal ligament was performed and showed statistically significant differences. The present results suggest that calbindin D28k may play important roles in the homeostasis and cytoprotection of the periodontal fibroblasts against occlusal force.


Asunto(s)
Fuerza de la Mordida , Ligamento Periodontal/metabolismo , Proteína G de Unión al Calcio S100/biosíntesis , Proteína G de Unión al Calcio S100/fisiología , Análisis de Varianza , Animales , Calbindina 1 , Calbindinas , Análisis del Estrés Dental , Fibroblastos/metabolismo , Inmunohistoquímica , Masculino , Mandíbula , Diente Molar , Ligamento Periodontal/citología , Ratas , Ratas Sprague-Dawley , Estadísticas no Paramétricas
20.
Arch Oral Biol ; 45(8): 639-45, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10869475

RESUMEN

Cacao bean husk extract (CBH) was examined for inhibitory effects on the caries-inducing properties of mutans streptococci in vitro and on caries development in specific pathogen-free Sprague-Dawley rats infected with mutans streptococci. CBH reduced the growth rate of almost all oral streptococci examined, which resulted in the reduction of acid production. Furthermore, insoluble glucan synthesis by the glucosyltransferases from Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 was significantly inhibited by CBH. Hence, the sucrose-dependent cell adherence of mutans streptococci was also depressed by CBH. The administration of CBH in drinking water resulted in significant reductions of caries development and dental plaque accumulation in rats infected with either Strep. sobrinus 6715 or Strep. mutans MT8148R, and the minimum cariostatic concentration was 1.0 mg/ml. These results indicate that CBH possesses powerful anticariogenic potential.


Asunto(s)
Cacao/uso terapéutico , Cariostáticos/uso terapéutico , Caries Dental/prevención & control , Fitoterapia , Estructuras de las Plantas/uso terapéutico , Análisis de Varianza , Animales , Adhesión Bacteriana/efectos de los fármacos , Caries Dental/microbiología , Placa Dental/prevención & control , Análisis Factorial , Glucanos/metabolismo , Glucosiltransferasas/antagonistas & inhibidores , Masculino , Extractos Vegetales/uso terapéutico , Polisacáridos Bacterianos/metabolismo , Ratas , Ratas Sprague-Dawley , Solubilidad , Organismos Libres de Patógenos Específicos , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/enzimología , Streptococcus mutans/crecimiento & desarrollo , Streptococcus sobrinus/efectos de los fármacos , Streptococcus sobrinus/enzimología , Streptococcus sobrinus/crecimiento & desarrollo , Sacarosa/metabolismo , Abastecimiento de Agua
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