PubMed Health⌕ Search

Biomedical subjects

H A Levin

Publications and source records attributed to H A Levin.

11 recordsLinked to original sources

Provider-based Medicare risk contracting and subcontracting: opportunities and risks for provider sponsored organizations.

Provider sponsored organizations (PSOs) are increasingly acquiring the risk for the management of Medicare Risk patients by accepting capitation directly from the Health Care Financing Administration (HCFA) or through contracts with HMOs or other organizations contracting with HCFA. The Medicare population and the requirements that the federal administration has put into place with respect to risk contracting are unique and demand specific responses on the part of the PSO for a contract to be successful. The PSO is cautioned to understand the actuarial risk, the clinical uniqueness of the Medicare beneficiary, Medicare reimbursement regulatory requirements, utilization management needs, and necessary reporting before entering into a contractual arrangement. This article attempts to describe some of the more common issues a provider organization must consider.

Capitation Fee↗

Analysis of a claims database for the identification of patients with carcinoma of the breast.

To develop and optimize algorithms for the identification of newly diagnosed and treated cases of women with carcinoma of the breast, an analysis was performed of cases identified from the claims database of a large health maintenance organization (U.S. Healthcare). An initial algorithm was developed from the patterns of claims which suggested common clinical presentations of carcinoma of the breast, and the positive predictive value was 88% (411/469). To attempt to improve upon the positive predictive value, multiple modifications of the initial algorithm were performed. The best identified modification of the initial algorithm yielded a positive predictive value of 93% (400/432) with a loss of only 3% (11/411) of the true positive cases. These results demonstrate that logic-based algorithms can be used as a valid and efficient method of identifying large numbers of cases from claims data with specific clinical characteristics. The best algorithm identified provides a powerful and accurate tool to perform health care analysis and research on large populations of women with newly diagnosed and treated carcinoma of the breast.

Adult↗

Thrombocytopenia associated with gold therapy. Observations on the mechanism of platelet destruction.

Severe thrombocytopenia developed in a patient with rheumatoid arthritis during gold therapy. Increased numbers of marrow megakaryocytes, shortened 51Cr-labeled platelet survival and platelet phagocytosis by splenic macrophages indicated that thrombocytopenia was due to excessive platelet destruction. Aurothiomalate disodium antigenicity was demonstrated by increased lymphocyte blastogenesis, and accentuation of blood and splenic leukocyte migration in the presence of the gold salt. In vitro splenic immunoglobulin G (IgG) production was markedly increased, and a significant portion of the culture-produced IgG attached specifically to homologous platelets and platelet membranes. Serum antiplatelet antibodies could not be demonstrated, nor could it be shown that gold enhanced the binding of splenic-synthesized IgG to platelets. The data indicate an immunologic mechanism for gold-associated thrombocytopenia and permit speculation as to possible ways in which unidentified antigens may be involved in the pathogenesis in idiopathic thrombocytopenic purpura.

Antigens↗

A new era.

Explore the source record for details and available documents.

Adolescent↗

The compartmentalization of antigen-reactive lymphocytes in desensitized guinea pigs.

A single injection of epsilon,DNP-Lys(7-10) can render previously sensitized guinea pigs specifically unreactive to subsequent intradermal challenge with that antigen. Antigen-reactive lymphocytes, as assayed by macrophage-migration in-inhibition or thymidine incorporation, were depleted from the peritoneal exudates of those animals. In contrast, it was intriguing to find that lymph node lymphocytes from such animals responded normally in the antigen-induced thymidine incorporation assay. These studies demonstrate a compartmentalization of antigen-reactive lymphocytes in desensitized animals which may account for the short-lived nature of this phenomenon.

Animals↗

Antigen recognition and antibody specificity. Carrier specificity and genetic control of anti-dinitrophenyl-oligolysine antibody.

The exact specifiicity of anti-DNP antibody produced by Hartley guinea pigs immunized with a series of defined alpha,DNP and epsilon,DNP-oligolysines was studied by fluorescence quenching. All responder animals made anti-DNP antibody which recognized the precise chain length, +/- 1 lysyl residue, of the DNP-oligolysines used to induce the immune response as measured by an increase in binding energy (-DeltaF degrees ) for that antigen. The ability of the immune system to detect the smallest possible change in oligolysine chain length suggests that the anti-hapten antibody-forming cell possesses a highly specific recognition system for carrier conformation. When DNP-oligolysines are incorporated in an adjuvant containing M. tuberculosis H37Rv, both responder and nonresponder produce anti-DNP antibody, but only the responder develops delayed skin sensitivity. In addition to their failure to develop delayed hypersensitivity, nonresponders produced anti-DNP oligolysine antibody which did not show the increase in -DeltaF degrees for the immunizing antigen characteristic of responder antibody. These observations support a local environment hypothesis for antigen recognition at the level of the anti-hapten antibody-forming cell and suggest that the polylysine gene exerts its control at the same cell.

Animals↗

Supine or recline.

Explore the source record for details and available documents.

Anesthesia, Dental↗