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Procedure Alone (procedure + alone)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Payment For Risk: Constant Beta Vs.

FINANCIAL REVIEW, Issue 2 2002
Dual-Beta Models
Fama and French's (1992) assertion that investors receive premium payments for risk associated with the book value to market price (BE/ME) and size and not for holding beta risk has sparked a lively debate concerning risk factors that are priced in the market. Howton and Peterson (1998) use a dual-beta model to test the Fama and French conclusions. They conclude that the significant relationship between beta and returns depends on the use of the dual-beta model. This work, however, ignores the results reported by Pettengill, Sundaram, and Mathur (PSM, 1995). PSM find a significant relation between a constant risk beta and returns when data are segmented between up and down markets, but do not consider the impact of size and BE/ME. In this paper we show that the PSM (1995) market segmentation procedure alone provides a sufficient condition to identify a significant relation between beta and returns in the presence of size and BE/ME. Dual market betas may be relevant in explaining risk and return. However, the market segmentation procedure of PSM (1995) is the critical condition for finding a significant relationship between returns and betas. [source]

Internal Sinus Manipulation (ISM) Procedure: A Technical Report

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2007
Jason M. Yamada DDS
ABSTRACT Background, The sinus augmentation procedure has facilitated dental implant treatment in the posterior maxilla where there is insufficient bone for implant placement. A modified Caldwell-Luc, lateral window technique can be applied in most cases needing sinus augmentation in order to create a larger bone volume. However, treatment morbidity can be a concern, especially in the form of postoperative swelling due to surgical trauma. Vertical augmentation using osteotomes has also been selected as a choice of treatment due to less invasive surgery and less postoperative trauma. Although the osteotome technique enables the surgeon to raise the sinus membrane internally through an implant osteotomy site, the quantity and predictability of bone augmentation can be limiting due to the elasticity of the Schneiderian sinus membrane, difficulty of the membrane to separate from the floor as well as the inability to have direct tactile access to "peel" the membrane off of the floor. Purpose, The objective of this report is to present a new, minimally invasive sinus augmentation technique, called the Internal Sinus Manipulation (ISM) procedure, which has been developed to facilitate sinus floor augmentation while reducing treatment morbidity and yet have direct tactile access to raise the membrane off of the sinus floor. Surgical Technique, Access to the Schneiderian sinus membrane is achieved without perforation of the membrane through a conventional osteotomy drilling procedure alone or combined with osteotome technique, followed by reflection of the membrane utilizing special ISM instrumentation and bone graft procedure laterally and vertically through the osteotomy site. A planned implant is then placed. Conclusion, The Internal Sinus Manipulation procedure can be used as an alternative treatment modality for sinus augmentation as compared to the external lateral window technique while reducing postoperative morbidity for the patients who need implant treatment in posterior maxillary areas. [source]

Bone formation by enamel matrix proteins and xenografts: an experimental study in the rat ramus

CLINICAL ORAL IMPLANTS RESEARCH, Issue 2 2005
Nikolaos Donos
Abstract: The aim of this study was to evaluate whether the use of enamel matrix proteins with or without the use of deproteinized bovine bone influences bone formation when used as an adjunct to guided bone regeneration (GBR). Twenty rats, divided into four groups of five animals each, were used in this study. Group A1: A hemispherical PTFE capsule was placed empty on the lateral aspect of the mandibular ramus (GBR). At the contralateral side of the jaw, the capsule was filled with an enamel matrix derivative (EMD) before its placement. The healing period was 60 days. Group A2: The animals were treated in the same manner as in Group A1 but with a healing period of 120 days. Group B1: The animals were treated in the same manner as in Group A1 with the difference that deproteinized bovine bone mineral (DBBM) particles were packed in the capsule. At the contralateral side of the jaw, the capsule was filled with a mixture of EMD and DBBM. The healing period was 60 days. Group B2: The same treatment as in B1 but with a healing period of 120 days. The histological analysis revealed that in Groups A1 and A2 newly formed bone was covering a significant part of the empty capsules (GBR). The use of EMD in the capsule did not offer any added benefit to the use of the capsule alone in terms of new bone formation. At Groups B1 and B2, the presence of DBBM and/or EMD did not positively affect the amount of new bone formation. It can be suggested that neither the application of EMD nor the use of DBBM or the combination of EMD and DBBM results in enhanced amounts of bone formation in comparison with the GBR procedure alone. Résumé Le but de cette étude a été d'évaluer si l'utilisation des protéines de la matrice amélaire avec ou sans l'utilisation d'os bovin déprotéiné influençait la formation osseuse lorsqu'il était utilisé comme complément à la régénération osseuse guidée (GBR). Vingt rats divisés en groupe de cinq ont servi lors de cette étude. Le groupe A1 : une caspule hémisphérique en téflon a été placée vide sur la face latérale de la branche montante mandibulaire (GBR). Du côté contralatéral de la mandibule, une capsule remplie de dérivés de la matrice amélaire (EMD) a été saturée avant son placement. La période de guérison a été de 60 J. Le groupe A2 : les animaux ont été traités de la même manière que dans le groupe A1 mais avec une période de guérison de 120 J. Le groupe B1 : les animaux ont été traités de la même manière que dans le groupe A1 avec la différence que les particules d'os déprotéiné (DBBM) ont été placées dans la capsule. Dans le côté contralatéral de la mandibule, les capsules ont été remplies avec un mélange d'EMD-DBBM. La période de guérison était de 60 J. Le groupe B2 : le même traitement que B1 mais avec une période de guérison de 120 J. L'analyse histologique a révélé que dans les groupes A1 et A2 de l'os néoformé recouvrait une partie significative des capsules (GBR). L'utilisation de EMD dans la capsule n'ajoutait aucune amélioration à l'utilisation de la capsule seule en tant que néoformation osseuse. Dans les groupes B1 et B2, la présence de DBBM et de EMD ou des deux ne changeait pas de manière positive la quantité de nouvel os formé. Ni l'application de EMD ni l'utilisation de DBBM ou d'une combinaison EMD-DBBM ne résulte en une augmentation des quantités de formation osseuse comparée au processus de GBR utilisé seul. Zusammenfassung Das Ziel dieser Studie war, auszuwerten, ob Schmelzmatrixproteine mit oder ohne Verwendung von deproteiniertem bovinem Knochen die Knochenbildung beeinflussen, wenn sie als Zusatz bei der gesteuerten Knochenregeneration (GBR) verwendet werden. Zwanzig Ratten, aufgeteilt in 4 Gruppen mit je 5 Tieren, wurden für die Studie verwendet. Gruppe A1: Eine halbkugelförmige PTFE-Kapsel wurde leer auf die laterale Fläche des Unterkiefer Ramus platziert. Auf der gegenüberliegenden Seite wurde die Kapsel vor der Platzierung mit Schmelzmatrixproteinderivat (EMD) gefüllt. Die Heilungszeit betrug 60 Tage. Gruppe A2: Die Tiere wurden auf die gleiche Art behandelt wie in Gruppe A1, aber die Heilungszeit betrug 120 Tage. Gruppe B1: Die Tiere wurden behandelt wie in Gruppe A1 mit dem Unterschied, dass deproteinierte bovine Knochenpartikel (DBBM) in die Kapsel gepackt wurden. Auf der gegenüberliegenden Seite des Kiefers wurde die Kapsel mit einem Gemisch aus EMD und DBBM gefüllt. Die Heilungszeit betrug 60 Tage. Gruppe B2: Es wurden die selben Behandlungen wie in Gruppe B1 durchgeführt, aber die Heilungszeit betrug 120 Tage. Die histologische Analyse zeigte, dass in den Gruppe A1 und A2 neugebildeter Knochen einen signifikanten Anteil der leeren Kapseln bedeckte (GBR). Der Einsatz von EMD in der Kapsel ergab gegenüber der leeren Kapsel keinen zusätzlichen Nutzen bezüglich Bildung von neuem Knochen. Bei den Gruppen B1 und B2 hatte der Einsatz von DBBM und/oder EMD keinen positiven Effekt auf die Menge an neu gebildetem Knochen. Es kann angenommen werden, dass weder die Applikation von EMD noch die Verwendung von DBBM oder einer Kombination EMD und DBBM im Vergleich zum GBR Verfahren allein zu einer geseigerten Knochenbildung führt. Resumen La intención de este estudio fue evaluar si el uso de proteína de la matriz del esmalte con o sin el uso de hueso bovino desproteinizado influye en la formación de hueso cuando se usa junto a regeneración ósea guiada (GBR). En este estudio se usaron veinte Ratas divididas en 4 grupos de 5 animales cada uno. Grupo A1: Se colocó una capsula hemiesférica vacía en el aspecto lateral de la rama mandibular (GBR). En el lado contralateral de la mandíbula, la capsula se rellenó con un derivado de la matriz del esmalte (EMD) antes de su colocación. El periodo de cicatrización fue de 60 días. Grupo A2: Los animales se trataron de la misma manera que en el grupo A1 pero con un periodo de cicatrización de 120 días. Grupo B1: Los animales se trataron en el mismo modo que en el grupo A1 con la diferencia que las cápsulas se rellenaron de partículas de hueso bovino desproteinizado (DBBM). En el lado contralateral de la mandíbula, la cápsula se rellenó con una mezcla de EMD y DBBM. El periodo de cicatrización fue de 60 días. Grupo B2: El mismo tratamiento que en B1 pero con 120 días de cicatrización. El análisis histológico reveló que en los grupos A1 y A2 un hueso neoformado cubría una parte significativa de las cápsulas vacías (GBR). El uso de EMD en la cápsula no ofreció ningún beneficio adicional al uso de la cápsula por si sola en términos de formación de nuevo hueso. En los grupos B1 y B2, la presencia de DBBM y/o EDM no afectó positivamente a la cantidad de hueso neoformado. Se puede sugerir que ni la aplicación de EMD o el uso de DBBM o la combinación de EMD y DBBM resultaron en cantidades mejoradas de formación de hueso en comparación con el procedimiento de GBR por si solo. [source]

Costs and Insurance Coverage Associated with Permanent Mechanical Cardiac Assist/Replacement Devices in the United States

JOURNAL OF CARDIAC SURGERY, Issue 4 2001
Roger W. Evans Ph.D.
Each year over 50,000 persons in the United States could potentially benefit from some form of permanent cardiac replacement or assistance. Approximately 7000 of these persons get on the waiting list for a transplant, and 2300 are transplanted. About 2000 patints are reportedly exposed to a mechanical cardiac assist device, most often as a bridge to transplant. The majority of persons who might benefit from cardiac replacement are never referred for treatment and, thus, the number of deaths on the waiting list is a misleading indicator of access to transplantation and overall patient mortality. The total economic burden associated with coronary artery disease and congestive heart failure now exceeds $140 billion each year, with approximately $700 million directly spent on heart transplant procedures alone. If a viable total artificial heart is devised to replace a failed heart, or a ventriular assist system to permanently assist a failing heart, direct aggregate expenditures alone are likely to be somewhere between $5.4 and $24.0 billion annually. Based on individual patient care costs, as well as aggregate national expenditures, insurers will be reluctant to pay for the permanent use of such devices, even though cost is reportedly not a consideration in coverage decisions. Today, medical benefits and added value are concepts that will shape the coverage determination process, as will increasingly liberal policies regarding payment for treatment costs in relationship to clinical trials. Nonetheless, resource allocation and rationing decisions loom large as strange "characters at play" on an international economic "stage," while being "directed" by worldwide health care needs. [source]