RESUMEN
Ribosomal proteins (RPs) play important roles in modulating the MDM2-p53 pathway. However, less is known about the upstream regulators of the RPs. Here, we identify SPIN1 (Spindlin 1) as a novel binding partner of human RPL5/uL18 that is important for this pathway. SPIN1 ablation activates p53, suppresses cell growth, reduces clonogenic ability, and induces apoptosis of human cancer cells. Mechanistically, SPIN1 sequesters uL18 in the nucleolus, preventing it from interacting with MDM2, and thereby alleviating uL18-mediated inhibition of MDM2 ubiquitin ligase activity toward p53. SPIN1 deficiency increases ribosome-free uL18 and uL5 (human RPL11), which are required for SPIN1 depletion-induced p53 activation. Analysis of cancer genomic databases suggests that SPIN1 is highly expressed in several human cancers, and its overexpression is positively correlated with poor prognosis in cancer patients. Altogether, our findings reveal that the oncogenic property of SPIN1 may be attributed to its negative regulation of uL18, leading to p53 inactivation.
Asunto(s)
Carcinogénesis/genética , Proteínas de Ciclo Celular/genética , Proteínas Asociadas a Microtúbulos/genética , Fosfoproteínas/genética , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Ribosómicas/genética , Proteína p53 Supresora de Tumor/genética , Animales , Carcinogénesis/metabolismo , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Células Cultivadas , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Células HEK293 , Humanos , Ratones , Proteínas Asociadas a Microtúbulos/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Ribosómicas/metabolismo , Subunidades Ribosómicas Grandes de Eucariotas/genética , Subunidades Ribosómicas Grandes de Eucariotas/metabolismo , Transducción de Señal/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
This article describes a method of in-office fabrication of an occlusal device for treatment of bruxism patients seeking a less costly alternative to laboratory-processed splints. This technique eliminates the need for mounted casts and the expense and delay associated with commercial laboratory involvement. It also minimizes patient and operator exposure to acrylic resin monomer and high temperatures associated with its polymerization reaction by use of a light-polymerized blue urethane dimethacrylate resin.
Asunto(s)
Bruxismo/terapia , Ferulas Oclusales , Diseño de Aparato Ortodóncico/métodos , Humanos , Factores de TiempoRESUMEN
STATEMENT OF PROBLEM: Removable partial denture frameworks are complex castings fabricated from high-shrinkage alloys. This may result in difficulty in achieving accurate fit. PURPOSE: The purpose of this study was to evaluate which component(s) of the clasp assembly contact the abutment tooth clinically. MATERIAL AND METHODS: New and existing frameworks with at least 1 conventional prepared occlusal rest were evaluated for fit. The spacing between the bottom of each of the rests of the 50 clasp assemblies and the corresponding rest seat were recorded with vinyl polysiloxane. The fit of each rest was determined with the use of a dial caliper by measuring, in micrometers, the thickness of the record between the rest and the bottom of the rest seat. The Kennedy classification was also recorded. A 2-sample t test was used to evaluate the difference in fit between tooth-tissue supported and tooth-supported designs (alpha=.05). RESULTS: The average space between the rest and prepared rest seat was 193 +/- 203 microm, with a range of 0 to 828 mum. Twenty tooth-tissue frameworks had an average space of 136 +/- 160 microm and 30 tooth-supported frameworks had an average space of 230 +/- 222 microm. The 2-sample t test showed no significant difference for fit between tooth-tissue supported and tooth-supported frameworks (P=.1081). Twenty-four percent of rests had contact in the prepared rest seat. CONCLUSION: The majority of rests evaluated did not contact the intended surfaces.
Asunto(s)
Pilares Dentales , Retención de Prótesis Dentales/métodos , Diseño de Dentadura , Dentadura Parcial Removible , HumanosRESUMEN
As an adjunct to infection control in dental impression procedures, several manufacturers have incorporated disinfectants into irreversible hydrocolloid impression materials. However, these compounds have been shown to be tissue irritants and capable of producing allergic reactions. An anonymous, self-administered questionnaire was distributed to 56 second-year dental students who had used an irreversible hydrocolloid containing a quaternary ammonium compound as an antimicrobial (Jeltrate Plus) to make impressions during a summer preclinical occlusion course. Within the limitations of this report, the incorporation of a quaternary ammonium compound into an irreversible hydrocolloid impression material resulted in a greater incidence of dermal and mucosal irritation.
Asunto(s)
Materiales de Impresión Dental/efectos adversos , Desinfectantes/efectos adversos , Mucosa Bucal/efectos de los fármacos , Piel/efectos de los fármacos , Adulto , Queilitis/inducido químicamente , Coloides/efectos adversos , Dermatitis Irritante/etiología , Dermatitis Profesional/etiología , Humanos , Irritantes/efectos adversos , Persona de Mediana Edad , Compuestos Orgánicos/efectos adversos , Compuestos de Amonio Cuaternario/efectos adversos , Estomatitis/inducido químicamenteRESUMEN
No single occlusal morphology, scheme, or material will successfully treat all patients. Many patients have been treated, both successfully and unsuccessfully, using widely varying theories of occlusion, choices of posterior tooth form, and restorative materials. Therefore, experience has demonstrated that there is no one righ r way to restore the occlusion of all patients. Partially edentulous patients have many and varied needs. Clinicians must understand the healthy physiologic gnathostomatic system and properly diagnose what is or may become pathologic. Henderson [3] stated that the occlusion of the successfully treated patient allows the masticating mechanism to carry out its physiologic functions while the temporomandibular joints, the neuromuscular mechanism, the teeth and their supporting structures remain in a good state of health. Skills in diagnosis and treatment planning are of utmost importance in treating these patients, for whom the clinician's goals are not only an esthetic and functional restoration but also a lasting harmonious state. Perhaps this was best state by DeVan [55] more than 60 years ago in his often-quoted objective. "The patient's fundamental need is the continued meticulous restoration of what is missing, since what is lost is in a sense irretrievably lost." Because it is clear that there is no one method, no one occlusal scheme, or one material that guarantees success for all patients, recommendations for consideration when establishing or reestablishing occlusal schemes have been presented. These recommendations must be used in conjunction with other diagnostic and technical skills.
Asunto(s)
Oclusión Dental , Dentadura Parcial Removible , Oclusión Dental Balanceada , Diseño de Dentadura , Humanos , Registro de la Relación Maxilomandibular , Arcada Parcialmente Edéntula/fisiopatología , Arcada Parcialmente Edéntula/rehabilitación , Planificación de Atención al Paciente , Diente ArtificialRESUMEN
The guidelines recommended in the literature for the convergence angle of a crown preparation vary from 3 to 24 degrees. There is a lack of guidelines on techniques to achieve a specific axial inclination. The purpose of this article was to present a practical technique, with a diamond rotary cutting instrument of known axial inclination, to determine the diamond rotary cutting instrument angulations required to achieve the desired axial inclination of a preparation.