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Biomedical subjects

C F Von Reyn

Publications and source records attributed to C F Von Reyn.

7 recordsLinked to original sources

Cytokine profiles in immunocompetent persons infected with Mycobacterium avium complex.

To evaluate the immunologic factors that contribute to protection against Mycobacterium avium complex (MAC), cytokine production by peripheral blood mononuclear cells (PBMC) from human immunodeficiency virus-negative persons with pulmonary MAC (MAC patients) and healthy control subjects with a delayed hypersensitivity skin test response to M. avium sensitin (MAS-positive control subjects) was measured. In MAC patients, mycobacterium-stimulated PBMC produced higher concentrations of interleukin (IL)-10 but lower concentrations of interferon (IFN)-gamma, IL-12, and tumor necrosis factor (TNF)-alpha, compared with PBMC from MAS-positive control subjects. Immunolabeling for intracellular IL-10 revealed that this cytokine was produced by both monocytes and T cells. Alveolar macrophages produced TNF-alpha and IL-10 in response to MAC, which suggests that these cytokines are produced in the lungs of patients with pulmonary disease caused by this pathogen. Our findings suggest that IFN-gamma, TNF-alpha, and IL-12 contribute to protection against MAC, whereas IL-10 is immunosuppressive.

Adult↗

Timing is everything.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗

In vitro cellular and cytokine responses to mycobacterial antigens: application to diagnosis of tuberculosis infection and assessment of response to mycobacterial vaccines.

Mycobacterial infection leads to the development of specific cell-mediated immune responses that have been measured clinically by assessing delayed-type hypersensitivity with Mantoux skin testing. Several characteristics of Mantoux skin testing for tuberculosis infection can make the procedure inaccurate, inconvenient, and sometimes misleading. It is also a poor predictor of immunity to tuberculosis in bacille Calmette-Gúerin vaccinees, yet decisions to revaccinate often are based on skin test responses after initial immunization. Skin testing with other mycobacterial antigens has similar limitations. In vitro assessment of cellular immunity to mycobacteria offers multiple, potential advantages over skin testing and has become technically feasible in recent years. Measurement of the effector functions that comprise cell-mediated immunity (eg, cytokine secretion and cytotoxicity) rather than cutaneous delayed-type hypersensitivity responses is more likely to reflect meaningfully specific mycobacterial immunity and, therefore, provide a means for determining mycobacterial immunity after immunization. Eliminating the variability in placement and interpretation inherent in skin testing could provide a more stable foundation for comparative studies in populations and improve decision making for individuals. Finally, in vitro testing permits the use of discrete mycobacterial antigens instead of crude protein preparations, allowing greater specificity in the detection of infection as well as assessment of responses to defined candidate vaccine antigens. Several studies have compared skin testing with in vitro proliferation of lymphocytes stimulated by mycobacterial antigens for the detection of Mycobacterium tuberculosis infection. Preliminary veterinary and human studies suggest that in vitro assessment of gamma-interferon production in response to mycobacterial antigens can be used to detect prior infection with organisms of the M tuberculosis complex. Streamlined techniques for in vitro testing of cellular immunity may allow its practical adoption in the clinical setting and lead to its use as a replacement for Mantoux skin testing.

Antigens, Bacterial↗

AIDS--A global perspective. Global epidemiology.

A total of 62,811 cases of the acquired immunodeficiency syndrome (AIDS) have been reported to the World Health Organization from throughout the world. Extensive epidemiologic studies have shown that human immunodeficiency virus (HIV) infections are transmitted by three routes: sexual, parenteral and perinatal. Three geographic patterns of transmission have been defined. In pattern I, transmission occurs predominantly among homosexual and bisexual men and urban intravenous drug abusers; transmission via blood products has been controlled; the male:female sex ratio is 10:1 or more; population HIV seroprevalence is low, and perinatal transmission is uncommon (for instance, United States, western Europe). In pattern II, transmission is predominantly heterosexual and perinatal; transmission via blood products exists but is being reduced; unsterile needles and other skin-piercing instruments cause some parenteral transmission (magnitude not known); the male:female sex ratio is 1:1, and population seroprevalence often exceeds 1% (central Africa, Haiti). In pattern III, AIDS cases are just being documented and are generally due to sexual exposure abroad or imported blood products (Middle East, Asia).

Acquired Immunodeficiency Syndrome↗

Infective endocarditis: an analysis based on strict case definitions.

Strict case definitions were applied to 123 clinically diagnosed cases of infective endocarditis. Cases were categorized as definite (19), probable (44), or possible (41) endocarditis or were rejected (19). Compared to other published studies, our patients had an advanced mean age (57), high incidence of underlying valvular disease (66%), short mean duration of symptoms (27 days), and 15% mortality, the lowest reported for a large series. Most cases were caused by viridans streptococci, Staphylococcus aureus, or enterococci; Enterobacteriacae were absent, and negative cultures infrequent (5%). Subgroups included nosocomial endocarditis (13%), usually with underlying valvular disease and invasive procedures; prosthesis endocarditis (12%); and cases requiring cardiac surgery (18%). Deaths were caused by heart failure, neurologic events, or superinfection. Strict definitions are useful in managing suspect cases, and are essential in comparing clinical studies. Early recognition and treatment should be the focus of efforts to reduce mortality from endocarditis.

Adolescent↗