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Biomedical subjects

R M May

Publications and source records attributed to R M May.

137 records · Page 8Linked to original sources
PubMedDate not supplied

Herd immunity to helminth infection and implications for parasite control.

Despite much research on immunological responses to helminth parasites, knowledge of the dynamic interplay between levels of herd immunity in humans and the rates of exposure, establishment and mortality of parasites remains limited. We describe here a simple mathematical model for the population dynamics of helminth infections which mirrors the development of a degree of acquired immunity within populations which are genetically heterogeneous with respect to immunological responsiveness. We interpret observed patterns in the age-specific intensity of infection and attempt to understand the possible effects of control measures based on chemotherapy and vaccination. Mass chemotherapy can, in some circumstances, reduce the level of herd immunity such that average worm burdens in the adult age classes rise above their precontrol levels. When certain individuals or groups are predisposed to heavy infection, selective or targeted drug treatment can have significantly greater impact than mass or random application. Conversely, model predictions suggest that effective parasite control by vaccination (if and when vaccines become available) is difficult to achieve in communities that are genetically heterogeneous in their ability to mount protective responses to infection.

Age Factors↗
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Vaccination and herd immunity to infectious diseases.

An understanding of the relationship between the transmission dynamics of infectious agents and herd immunity provides a template for the design of effective control programmes based on mass immunization. Mathematical models of the spread and persistence of infection provide important insights into the problem of how best to protect the community against disease.

Age Factors↗
PubMedDate not supplied

Transmission dynamics of HIV infection.

Simple mathematical models of the transmission dynamics of human immunodeficiency virus help to clarify some of the essential relations between epidemiological factors, such as distributed incubation periods and heterogeneity in sexual activity, and the overall pattern of the AIDS epidemic. They also help to identify what kinds of epidemiological data are needed to make predictions of future trends.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Using flowcharts in policy development: reporting abuse and neglect of patients.

Reports of abuse, both domestic and institutional, are increasingly common. A myriad of statutes and rules govern when and how incidents of abuse are reported. It is incumbent upon medical centers to establish policies that clearly outline the responsibility of all staff members to identify and report suspected abuse and neglect. This article presents a summary of a comprehensive hospital policy on identifying and responding to all types of suspected or witnessed abuse and neglect of patients. It also illustrates how multidisciplinary teams and flowcharts can be useful in developing and implementing policy in complicated areas that involve many players, rules, and regulations.

Data Collection↗
PubMedDate not supplied

Cytoimmunologic monitoring after heart and heart-lung transplantation.

The ability of cytoimmunologic monitoring to detect acute rejection in heart and heart-lung transplant recipients was assessed. Seventeen heart and nine heart-lung transplant patients treated with cyclosporine as the primary immunosuppressive agent were monitored after operation. Seventeen acute rejection episodes occurred in the heart-only recipients and 12 in the combined heart-lung recipients. These acute rejection reactions were accompanied by increased numbers of "activated" lymphocytes in all but one case, providing cytoimmunologic monitoring a sensitivity of 100% in the heart-lung recipients and 94% in the heart recipients. The specificity was, however, low (68% in the heart recipients and 55% in the heart-lung recipients). Seventy-two percent of the false-positive results were associated with viral infections, particularly cytomegalovirus infections.

Adolescent↗