PubMed Health⌕ Search

Biomedical subjects

J Keefe

Publications and source records attributed to J Keefe.

12 recordsLinked to original sources
PubMed1992

Clinical use of injectable bovine collagen: a decade of experience.

Bovine collagen has long been recognized as a safe, highly biocompatible material. In 1981 and 1985, two injectable fibrillar suspensions of purified bovine dermal collagen, Zyderm and Zyplast collagen implant, were commercially launched in the USA for use in soft tissue contour irregularities. Since that time more than 750 000 patients have been treated with Zyderm and/or Zyplast collagen implants internationally. Adverse reactions to bovine collagen implants occur in a small percentage of treated patients. The most prevalent adverse reaction is localized hypersensitivity at treatment sites, occurring in 3% of skin tested patients and 1 to 2% of the treated patients. These reactions resolve with time as the implant material is resorbed by the host. Circulating antibodies to bovine collagen can be demonstrated in the sera of a majority of patients (90-100%) with local hypersensitivity. These antibodies are specific for bovine collagen and do not cross react with human type I, II or III collagen. Although the presence of a humoral immune response to bovine collagen can be associated with localized symptoms of hypersensitivity, antibodies to bovine collagen can also be demonstrated in the absence of any clinical manifestation.

Animals↗
PubMed1990

Immune responses to allogeneic and xenogeneic implants of collagen and collagen derivatives.

Whereas xenogeneic collagen has provided a safe and effective biomaterial for numerous medical applications, there are few instances in which data permit the correlation of the immunologic profile of well-defined devices with their clinical sequelae. A major exception is the use of injectable bovine dermal collagen for soft-tissue contour correction. The low incidence of hypersensitivity has been studied in the context of clinical efficacy and safety with several devices. The findings indicate that such immunity usually results in the manifestation of local symptoms of dermal inflammation at sites of treatment that resolve as the implant is resorbed by the host. In contrast, more immunogenic hemostatic agents may elicit a more frequent or vigorous immune response that is not clinically visible or relevant in that application. Recent experiences with collagen-based devices for the repair and regeneration of bone have also demonstrated that the presence of immunity to their collagenous or non-collagenous components does not necessarily predict adverse clinical sequelae. Indeed, numerous specific data indicate that this immunity can exist as an epiphenomenon with no effect on osteogenesis. To get a true composite picture of biocompatibility, significant steps must be taken to characterize biomaterials properly and to ensure that immunologic, clinical, histologic, and other pertinent laboratory data are viewed in relation to one another and not in isolation.

Antibodies↗
PubMed1986

A new advancement in noninvasive electrophysiology: a standard laboratory stimulator pulse coupled with an implanted pacemaker.

A new device for coupling the pulse from a standard laboratory stimulator to commercially available implanted pacemakers for use in noninvasive electrophysiology testing has been developed. When programmed to an electrophysiology mode, a 37 kHz carrier wave, generated by the programmer, maintains communication with the implanted pacemaker. Stimuli generated from a standard lab stimulator cause a break in the carrier wave and an output from the pacemaker. Cycle lengths as short as 127 msec can be attained. In addition to standard electrophysiology testing, this noninvasive electrophysiological technique can be used to fibrillate the heart to test the efficacy of automatic implantable cardioverter/defibrillators.

Electric Stimulation↗
PubMed1984

Radiology manager: the critical link in hospital-physician joint ventures.

Mounting capitalization obstacles and growing competition require hospitals to explore nontraditional avenues in acquiring and offering services. This first of a two-article series outlines the reasons behind the increasing popularity of hospital-physician joint venture agreements for diagnostic imaging equipment, and the contributions radiology administrators should make in the formation of such enterprises.

Administrative Personnel↗
PubMed1983

Managing DRGs: knowing what to cut--and when.

Medicare's new DRG prospective reimbursement is based upon a methodology diametrically opposed to the incentives of its traditional retrospective, cost-based system. The agreement to a phase-in period for DRGs, with reimbursements based on both the cost-based and DRG-based methodologies for three years, creates a fundamental conflict and unique managerial challenge for radiology and other hospital administrators. It means they must know both what to cut under DRGs and when to cut them during and after the phase-in.

Costs and Cost Analysis↗