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J L Wagner

Publications and source records attributed to J L Wagner.

At least 91 records · Page 5Linked to original sources
PubMed1984

Radioimmunoassay for anaphylatoxins: a sensitive method for determining complement activation products in biological fluids.

Activation of the blood complement system generates bioactive fragments called anaphylatoxins. The three anaphylatoxins C3a, C4a, and C5a are released during "classical pathway" activation while only C3a and C5a are released when the "alternative pathway" of complement is activated. Radioimmunoassays were designed to individually detect and quantitate the activation fragments C3a, C4a, and C5a in biological fluids without interference from the precursor molecules C3, C4, and C5. Kinetics of complement activation in fresh human serum exposed to the activators zymosan, heat-aggregated immunoglobulin, or cobra venom factor were monitored using the radioimmunoassay technique. For the first time, activation of components C3, C4, and C5 was followed simultaneously in a single serum sample. Analysis of the patterns and extent of anaphylatoxin formation during activation in serum may be used to screen for deficiencies or defects in the complement cascade. Levels of the anaphylatoxins in freshly drawn serum were much higher than levels detected in EDTA-plasma. Detection limits of anaphylatoxins in plasma are governed by background levels of 152 +/- 69, 155 +/- 33, and 5.4 +/- 6.6 ng/ml for C3a, C4a, and C5a, respectively. Detection of low-level complement activation in patient's blood, urine, or synovial fluid, using anaphylatoxin formation as an indicator, may prove useful in signaling numerous forms of inflammatory reactions. The demonstration of anaphylatoxins in clinical samples is being recognized as a valuable diagnostic tool in monitoring the onset of immune disease.

Anaphylatoxins↗
PubMed1984

Prospective reimbursement and the diffusion of new technologies in hospitals.

This paper presents new evidence on the effects of prospective hospital reimbursement on the diffusion of new medical technologies in American hospitals. The probability, speed, and extent of adoption of five specific new technologies in six states, three with prospective reimbursement and three without, are examined using the results of a hospital survey conducted by the American Hospital Association for this study in 1980. The analysis demonstrates the influence of prospective reimbursement on the diffusion of new technologies. It is clear as well that these effects depend upon the specific attributes of the prospective reimbursement program and the characteristics of the technologies themselves.

Capital Expenditures↗
PubMed1984

Healing of fractures with freeze-dried cortical bone plates. Comparison with compression plating.

The healing of fractures of the radius with internal fixation by stainless-steel compression plates was compared with fractures fixed with freeze-dried bone-plate allografts. Fractures fixed with metallic plates gained slightly less than half the biomechanical strength of the contralateral control bone and healed without noticeable external callus formation. Bone-plated fractures regained three-fourths of the biomechanical strength of controls and healed by forming an external callus. Bone-plate allografts were eventually incorporated in the host bone. Allograft plates were vascularized and remodeled into cancellous bone in the process of incorporation in the host bones.

Animals↗
PubMed1983

The feasibility of economic evaluation of diagnostic procedures.

This paper reviews the principles of cost-benefit and cost-effectiveness analysis as they are applied to diagnostic procedures. These medical procedures present particularly thorny problems to those who would subject them to economic evaluation. Five specific problem areas encountered in attempting to apply economic evaluation to diagnostic procedures are discussed in detail. They are: defining homogeneous patient groups for analysis; specifying the relevant diagnostic alternatives; measuring diagnostic accuracy; measuring diagnostic costs; and specifying the measured outcomes of the diagnostic process. The economic evaluation literature on two diagnostic procedures--the skull X-ray and computed tomographic (CT) scanning is reviewed within the context of a model of economic evaluation. Two studies were found to successfully apply the principles of economic evaluation to CT scanning; none were found for skull X-rays. The most common approaches to evaluating the usefulness of these procedures, and the limitations of these approaches, are summarized.

Cost-Benefit Analysis↗
PubMed1981

Murine cytomegalovirus infection: hematological, morphological, and functional study of lymphoid cells.

Mice were studied for 3 to 4 months after murine cytomegalovirus (MCMV) infection. Serial hematological parameters were evaluated. It was found that MCMV infection of mice were accompanied by the appearance of many atypical lymphocytes similar to those seen in association with the hematological features of mononucleosis associated with human CMV infection. Certain functions of splenocytes were studied in infected and uninfected animals during the 4 months after MCMV infection. Three periods were identifiable by the functional response of splenocytes during the course of MCMV infection. The initial phase was characterized by an elevated response of splenocytes to a T cell mitogen and a B cell mitogen (phytohemagglutinin and lipopolysaccharide, respectively). The intermediate phase was marked by productive virus replication in the salivary gland, injury to lymphoid elements, a depressed response of splenocytes to mitogens (phytohemagglutinin and lipopolysaccharide), and decreased humoral splenocytes to phytohemagglutinin stimulation was again increased, and a nonproductive latent infection was established. Study by scanning electron microscopy of splenocytes during the course of infection revealed morphological changes which were correlated with functional alterations.

Animals↗
PubMed1980

Fatal Yersinia pseudotuberculosis infection in captive bushbabies.

Fatal Yersinia pseudotuberculosis infection was diagnosed in 3 bushbabies (Galago crassicaudatus) in a large prosimian colony. The clinical signs were diarrhea, dyspnea, hyperthermia, dehydration, and lethargy. Histologically, the disease was characterized by lesions of ulcerative enterocolitis, necrotizing hepatitis, splenitis, lymphadenitis, and nonsuppurative pneumonitis.

Animals↗
PubMed1979

Reimbursement shapes market for technology.

Methods of reimbursing health care providers affect their decisions about adoption and use of new medical technologies, but how they can elicit good decisions is unclear.

Capital Expenditures↗
PubMed1979

Spontaneous cholangiocarcinoma in a ring-tailed lemur (Lemur catta).

A cholangiocarcinoma in the liver with metastasis to the regional lymph nodes was found in a male ring-tailed lemur (Lemur catta). The liver was partially replaced by a gray-white, coarsely lobulated mass. Microscopically, the tumor consisted of well circumscribed lobules of anaplastic, low cuboidal cells occasionally arranged in duct-like structures. The tumor did not involve the gallbladder.

Adenoma, Bile Duct↗
PubMedDate not supplied

Cost-effectiveness of screening for common cancers.

Consideration of cost-effectiveness has guided public and insurers' decisions about preventive services for almost 20 years. Legislative decisions on coverage of specific cancer screening tests under Medicare and Medicaid have traditionally followed studies of their cost-effectiveness. This paper reviews the principles of cost-effectiveness analysis in health care. Cost-effectiveness analysis is a stylized form of investment analysis, where the returns on the investment are measured in improvements in health rather than in dollars and consider society as a whole as the relevant investor. Cost-effectiveness studies of screening for two common cancers, cervical and colorectal, illustrate the strengths and weaknesses of cost-effectiveness analysis. Dependence on models of the disease process, which may be sketchy, and uncertainty about costs and benefits of screening are inherent in the methodology. Although economic evaluations of both cervical and colorectal cancer screening have found them to be relatively cost-effective compared with doing nothing, such studies have not resolved the uncertainty about the best screening strategy for either disease. With cervical cancer, new evidence about the relationship between human papilloma virus and high-grade neoplasia suggests the need for new models of the disease process that can support additional cost-effectiveness analyses. Colorectal cancer screening models must be validated against new information from recent randomized clinical trials. Despite uncertainty and contradictions in existing studies of screening for both diseases, investment models force clinicians and decision-makers to consider all important consequences for health care costs and outcomes.

Colorectal Neoplasms↗
PubMedDate not supplied

Organization of the canine major histocompatibility complex: current perspectives.

The dog is a valuable model for studying several human diseases as well as one of the most important models for organ transplantation. Important to understanding the pathophysiology or development of some of these diseases is an understanding of the canine major histocompatibility complex (MHC) or dog leukocyte antigen (DLA). Initial characterization of the DLA involved primarily cellular, serological, and biochemical analyses. Later a molecular analysis of the DLA region was begun. There are at least four complete class I genes: DLA-88, DLA-12, DLA-64, and DLA-79. DLA-88 is highly polymorphic, with more than 40 alleles obtained from an examination of 50 mixed breed dogs. The other class I loci are less polymorphic, with fewer than 12 alleles each. In the class II region there is one complete DRB gene called DLA-DRB1 with at least 24 alleles and one full-length DQB gene, DLA-DQB1, with 20 alleles characterized to date. DLA-DQA is less polymorphic with nine alleles and DLA-DRA appears monomorphic. Two highly polymorphic canine microsatellite markers, one located in the class I region and one located in the class II region, can be used to identify DLA-matched and -mismatched dogs within families for organ transplantation experiments. Future projects include mapping the DLA region by pulsed-field gel electrophoresis and using a recently constructed canine bacterial artificial chromosome (BAC) library to search for new genes within the DLA. The dog has been a useful model for understanding several human diseases such as gluten-sensitive enteropathy (Hall and Batt 1990), rheumatoid arthritis (Halliwell et al. 1972), narcolepsy (Tafti et al. 1996), and systemic lupus erythematosus (Lewis and Schwartz 1971, Teichner et al. 1990), as well as an important model for solid organ and hematopoietic stem cell transplantation (Storb and Deeg 1985). Much of the impetus behind efforts to characterize the canine MHC comes from its importance in transplantation. In spite of the dog's importance in studying human disease and in immunology, molecular analysis of the DLA has lagged behind that of the mouse and human as well as several agricultural animals.

Animals↗