Physics, Bible Used to Reexamine if Heaven Is Hotter than Hell

S

Effect of specific inhibition of gamma-glutamyl transpeptidase on amino acid uptake by mammary gland of the lactating rat

AbstractWe showed [Biochem. J. (1981) 194, 99–102] that inhibition of γ-glutamyl transpeptidase in vivo with serine-borate decreases amino acid uptake by mammary gland. However, doubts arose about the validity of this inhibitor in metabolic studies because it must be used in very large amounts. New Inhibitors have been isolated, like anthglutin and acivicin, which are effective at low concentrations in vivo. Here, we show that treatment of lactating rats with these substances decreases the transpeptidase activity and the amino acid uptake by the gland. These results support the hypothesis that the γ-glutamyl cycle functions as an amino acid transport system in mammary gland

Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells

Background: Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O 2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. Material and Methods: One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. Results: Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ ml of thermolysine for 40 minutes and sonicating the culture for one minute. Conclusions: Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agent

Application of mesenchymal stem cells in bone regenerative procedures in oral implantology. A literature review

Objective: The aim of this work was to review de literature about the role of mesenchymal stem cells in bone regenerative procedures in oral implantology, specifically, in the time require to promote bone regeneration. Study Desing: A bibliographic search was carried out in PUBMED with a combination of different key words. Animal and human studies that assessed histomorphometrically the influence of mesenchymal stem cells on bone regeneration procedures in oral implantology surgeries were examined. Reults: - Alveolar regeneration: Different controlled histomorphometric animal studies showed that bone regeneration is faster using stem cells seeded in scaffolds than using scaffolds or platelet rich plasma alone. Human studies revealed that stem cells increase bone regeneration. - Maxillary sinus lift: Controlled studies in animals and in humans showed higher bone regeneration applying stem cells compared with controls. - Periimplantary bone regeneration and alveolar distraction: Studies in animals showed higher regeneration when stem cells are used. In humans, no evidence of applying mesenchymal stem cells in these regeneration procedures was found. Conclusion: Stem cells may promote bone regeneration and be useful in bone regenerative procedures in oral implantology, but no firm conclusions can be drawn from the rather limited clinical studies so far performed

Obtención y caracterización de células madre de pulpa dental humanas e interacción con β-fosfato tricálcico

OBJETIVOS Objetivo general: Obtener células madre de pulpa dental, optimizar el método de obtención y de cultivo de estas células, y estudiar su interacción con el biomaterial β-fosfato tricálcico. Objetivos específicos: 1- Obtener células madre de pulpa dental. 2- Optimizar el método de obtención de células madre de pulpa dental. 3- Caracterizar células madre de pulpa dental usando microscopía confocal. 4- Estudiar el crecimiento de células madre de pulpa dental a distintas presiones de O2 para optimizar su cultivo. 5- Estudiar la adhesión y el crecimiento de células madre de pulpa dental sobre el biomaterial β-fosfato tricálcico. MATERIAL Y MÉTODOS Se realizó un estudio prospectivo, in vitro, no controlado. Los dientes fueron extraídos por odontólogos de la Unidad de Cirugía de la Clínica Odontológica de la Facultad de Medicina y Odontología de la Universidad de Valencia, entre Mayo de 2008 y Marzo de 2012. Para obtener células madre de pulpa dental: 1- Se seccionó la pulpa dental mecánicamente con una hoja de bisturí nº10. 2- Se recogieron los fragmentos y se realizó la digestión de estos con 2 mg/mL de colagenasa tipo I durante 90 minutos (Método A) en condiciones de 37°C, 5% CO2 y 3% O2 Se centrifugó a 1000 g durante 2 minutos y se recogió el precipitado y cultivó en medio de cultivo completo a 37°C, 5% CO2 y 3% O2. En base a este protocolo se realizaron 8 protocolos más con distintos agentes digestivos, disgregantes o combinándolos. Se estudió el rendimiento para la obtención y el tiempo mínimo necesario para obtener las células. También se caracterizaron las células con marcadores de superficie, se cultivaron a distintas presiones de oxígeno y se realizazó una curva de crecimiento. Por último, se estudió la ahesión y crecimiento de CMPD a β- fosfato tricálcico. RESULTADOS Se obtuvieron CMPD con todos los métodos menos con la fragmentación mecánica de la pulpa. Las células fueron positivas para los marcadores de superficie de células mesenquimales y negativos para los de células hematopoyéticas. Las CMPD proliferaron más en condiciones tisulares de O2 (3%) que en condiciones ambientales (21%) y fueron capaces de proliferar sobre el biomaterial de regeneración ósea biomaterial β-fosfato tricálcico. CONCLUSIONES 1- En nuestro grupo hemos obtenido células madre de pulpa dental, permitiéndonos así, determinar las condiciones óptimas para su aislamiento y cultivo. 2- De todos los métodos empleados para su obtención, la digestión de la pulpa con EDTA, colagenasa/dispasa, termolisina y sonicación, fue el que demostró mayor velocidad de aislamiento de las células. 3- Las células obtenidas de la pulpa dental fueron positivas para los marcadores CD-133, Oct4, Nestin, Stro-1, demostrando sus características de células madre mesenquimales. Además fueron negativas para el marcador de células madre hematopoyéticas CD-45. El marcador CD-34 fue positivo en un caso y negativo en otro. 4- Las células madre de pulpa dental mostraron una tasa de proliferación mayor al ser cultivadas bajo condiciones fisiológicas de O2 (3%) que bajo condiciones ambientales (21% O2). 5- Las células madre de pulpa dental tienen la capacidad de adherirse y proliferar sobre el biomaterial de regeneración ósea β-fosfato tricálcic

Correcting loss of a papilla following orthodontic space opening (Atherton's patch) through implant supported rehabilitation. A case report

The objective of this case report is to describe a surgical and prosthetic technique to create a lost papilla following orthodontic space opening (Atherton`Ls patch) through implant supported rehabilitation. A switching platform implant was used to replace a left maxillary canine in a unitary interdental edentulous ridge with Atherton'Ls patch in the distal area of the upper lateral left incisor. The radiographic study revealed correct level of the interproximal bone of the adjacent teeth. A mucoperiosteal flap with crest incision and sulcular extension to the adjacent teeth was made. Special attention was paid to correct position of the implant and the distance (. 1.5 mm) between the platform and the roots of the adjacent teeth. A submerged technique was used. Tissue modeling through provisional crown was performed in order to create an ideal emergence profile with total papilla fill recorded at the Atherton'Ls patch area. Final screw retained CAD-CAM zirconia structure was place. Final follow up was performed 2 years after provisional crown placement, and total fill of both papilla, including at Atherton'Ls patch area, was recorded

Dos fuentes para una etnohistoria de la música en Venezuela

En este artículo se revisan dos textos de la historiografía musical venezolana,por ser pioneros en la investigación arqueológica y antropológica como fuentes parael conocimiento de la historia de la música en Venezuela: Die guajiro indianer EineEthnographische Skizze (1870) de Adolfo Ernst y Contribución al estudio de la músicaen Venezuela (1939) de José Antonio Calcaño. Se realiza un ejercicio de revisión de laliteratura historiográfica musical desde una perspectiva analítica que los valoriza comofuentes para una etnohistoria, punto de partida para emprender otros trabajos similaresque ayuden a entender este universo; si bien no fueron concebidos con una expresa intencionalidadetnohistórica, se internan en áreas que son propias de lo que se considerahoy ámbito de la etnohistoria

Influence of perforation of the sinus membrane on the survival rate of implants placed after direct sinus lift : literature update

The aim of this paper was to review the procedures adopted when a perforation of the sinus membrane takes place during a direct sinus lift for filling with bone graft; and the survival of implants in those cases in which perforation of the sinus membrane occurred. A bibliographical search in PUBMED was carried out of articles published from 1997 to 2008, with the key words ?sinus perforation? and ?membrane perforation?. All articles specifying the two following criteria were included: (a) procedure in the case of perforation of the sinus membrane during direct sinus lift; and (b) the number and survival rate of implants placed in direct sinus lift with perforated and non perforated membrane. Six articles fulfilled the inclusion criteria. In all the articles the sinus lift was continued when a perforation of the sinus membrane took place. In maxillary sinus lift procedures with perforation of the membrane a 88.6% implant survival rate was obtained, and in maxillary sinus lifts with intact membrane the survival rate rose to 98%. In case of small perforation of the sinus membrane, it is possible to continue with the procedure; there is no consensus on the procedure when a perforated membrane is to be repaired, but the method of choice according to the majority of authors is to use a resorbable membrane. In the case of large perforation, there is no consensus either, although the majority of authors choose to abandon the procedure. The survival of the implants diminishes when they are placed in sinus lifts with perforated membrane