RESUMEN
Enamel is the highly mineralized outer layer of teeth; the cells responsible for enamel formation are ameloblasts. Local hypoxia and hypoxia inducible factor (HIF) in embryonic tissues are important to promote normal organogenesis. However, hypoxic state in tooth germs and the roles of HIF in ameloblast differentiation have not been understood. The aim of this study is to clarify the role of HIF in ameloblast differentiation during tooth germ development. We found that tooth germs were under hypoxia and HIF-1α and HIF-2α were expressed in tooth germs in embryonic mice. Then, we used HIF inhibitors to evaluate the function of HIF during tooth germ development. The HIF-2α inhibitor significantly decreased the size of tooth germs in organ culture, while the HIF-1α inhibitor did not apparently affect the size of tooth germs. The HIF-2α inhibitor enhanced the expression of amelogenin, a marker of ameloblast differentiation, in the tooth germs in organ culture and rat dental epithelial SF2 cells. Moreover, we found that the HIF-2α inhibitor-stimulating amelogenin expression was regulated by hes-related family basic helix-loop-helix transcription factor with YRPW motif 2(Hey2) in SF2 cells. These findings suggest that the HIF-2α-Hey2 axis plays an important role in ameloblast differentiation during tooth germ development.
Asunto(s)
Ameloblastos , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Odontogénesis , Proteínas Represoras , Animales , Ratones , Ratas , Ameloblastos/metabolismo , Amelogenina/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Hipoxia/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismoRESUMEN
A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.
RESUMEN
OBJECTIVE: Nasal T/natural killer cell lymphomas (NTCL) are highly prevalent among Oriental populations. However the characteristic immunophenotype of NTCL is still controversial and it can be difficult to make a firm histologic diagnosis of malignancy. Therefore, 14 cases of NTCL in patients from southern Japan were evaluated for clinicopathological features and immunophenotypic status. Furthermore, the genetic variations in the latent membrane protein 1 (LMP-1) gene of Epstein-Barr virus (EBV)-related NTCL were evaluated. METHODS: Biopsy specimens were fixed in formalin and embedded in paraffin before examination using in situ hybridization for EBV-encoded RNA-1 (EBER-1) as well as immunohistochemical staining for CD3, CD3epsilon, CD4, CD8, CD43, CD45RA, and CD45RO. To detect genetic variations, single-strand conformation polymorphism (SSCP) analysis and DNA sequencing were applied. RESULTS: Clinically, 14 cases were divided into two groups. The first group consisting of eight patients showed good prognosis. The other group consisting of six patients showed poor prognosis. The vast majority of neoplastic cells in NTCL were EBER-1 positive. These cells did not express CD4, CD8, or CD45RA, but often expressed CD43 and CD45RO. In addition, they were negative for CD3 when stained with a mouse monoclonal antibody but stained for CD3epsilon when a rabbit polyclonal was used. The 3'-terminal of LMP-1 gene of seven cases were amplified and all of them have 30 base pair (bp) deletion. CONCLUSION: NTCL are a heterogeneous mix of cell types although EBV-associated NTCL in patients from southern Japan appear to originate from natural killer cells rather than T cells, and also prognosis is variable and not always poor. The ability to make a firm diagnosis can be enhanced through the combined use of in situ hybridization and immunohistochemistry. High prevalence of the 30-bp deletions of the LMP-1 gene in EBV-related NTCL may also reflect the prevalence of the deletion variant in the normal population in Japan.
Asunto(s)
Infecciones por Virus de Epstein-Barr/complicaciones , Células Asesinas Naturales/virología , Linfoma de Células T/virología , Neoplasias Nasofaríngeas/virología , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/metabolismo , Femenino , Eliminación de Gen , Expresión Génica/genética , Humanos , Inmunohistoquímica , Hibridación in Situ , Células Asesinas Naturales/metabolismo , Linfoma de Células T/genética , Linfoma de Células T/metabolismo , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , ARN Viral/genética , Proteínas de la Matriz Viral/genética , Proteínas de la Matriz Viral/metabolismoRESUMEN
We evaluated the apnea index (AI), the oxygen saturation above 95% (SA95), the lowest oxygen saturation (LSAT), and snoring before and after laser-assisted uvulopalatoplasty (LAUP) in 106 patients with obstructive sleep apnea syndrome (n=59) or snoring (n=47). Type 1 LAUP was performed in 42 patients and type 2 LAUP in 64 patients. A 50% or greater reduction in AI was observed in 15 patients (35.7%) who underwent type 1 LAUP and 37 patients (57.8%) who underwent type 2 LAUP. Snoring was diminished in 18 (51.4%) of 35 patients who underwent type 1 LAUP and 30 (55.6%) of 54 patients who underwent type 2 LAUP. SA95 and LSAT showed no difference. No serious complications such as significant bleeding, postoperative episodes of asphyxia, nasopharyngeal stenosis, or nasal regurgitation were observed. LAUP was an effective outpatient treatment.
