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Biomedical subjects

J M Jason

Publications and source records attributed to J M Jason.

29 records · Page 2Linked to original sources
PubMed1985

HTLV-I antibody status in hemophilia patients treated with factor concentrates prepared from U.S. plasma sources and in hemophilia patients with AIDS.

Serum samples from 85 Austrian hemophilia patients treated with lyophilized factor concentrates prepared from U.S. plasma sources, 24 hemophilia patients from Georgia on a home therapy program with factor concentrates, and 10 U.S. hemophilia patients with acquired immunodeficiency syndrome (AIDS) were analyzed by two different methods for the presence of antibodies to the major internal antigen of human T-cell leukemia virus I (HTLV-I) p24. All but one, a Georgia sample, were negative. The absence of antibody to HTLV-I p24 in the serum of European hemophilia patients, of U.S. hemophilia patients with no symptoms of AIDS, and of U.S. hemophilia patients with AIDS is interpreted as an indication of the lack of ready transmissibility of HTLV-I in lyophilized factor concentrates.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Human T-cell leukemia virus (HTLV-I) p24 antibody in New York City blood product recipients.

Human T-cell leukemia virus (HTLV-I) is known to be associated with certain hematologic malignancies, and a related virus, HTLV-III/LAV, might be the cause of AIDS. Some persons with AIDS have had evidence of HTLV-I infection. Unrelated to these findings, it has been suggested that HTLV-I is transmitted via blood products. We therefore evaluated the serologic status to the HTLV-I core antigen p24 of 48 persons with hemophilia (Hem A) receiving factor concentrate therapy (a group at risk for AIDS), 49 persons with beta-thalassemia major (Thal) receiving frozen packed red blood cells therapy (FPRC), 26 patients with sickle cell anemia (SCA) receiving FPRC, and 18 persons not receiving any blood products. All participants were clinically well; only one had a risk factor other than hemophilia for AIDS, and all were from New York City, an area with a high incidence of AIDS. No Hem A or nontransfused persons had serum antibody to HTLV core p24 antigen; three with Thal and one with SCA were antibody-positive. These results were confirmed by both radioimmunoprecipitation and Western blot techniques. Positive serology did not correlate with any immune findings or quantity of blood products used. These data support that HTLV-I is preferentially transmitted through cellular blood products and that it is an infection for which cellular blood product recipients in at least some areas of the United States are at risk. Concentrate products appear free of transmission risk relative to cellular blood products, but we cannot be certain that this safety is absolute. The public health implications of blood product transmission of HTLV-I merit active, long-term investigation.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Pseudomonas cepacia colonization in patients with cystic fibrosis: risk factors and clinical outcome.

During the period of 1979 to 1983, 38 patients with cystic fibrosis (CF) at the CF center of St. Christopher's Hospital for Children in Pennsylvania developed respiratory tract colonization with Pseudomonas cepacia. Seventeen (45%) of the patients with colonization died. Yearly incidence rates of P. cepacia colonization fluctuated between 1.3% and 6.1%, suggesting an endemic phenomenon. Case-control studies showed that severe underlying CF, use of aminoglycosides, and having a sibling with CF and P. cepacia colonization were significant risk factors for P. cepacia colonization. Once colonized with P. cepacia, patients with CF were likely to be hospitalized longer (P = 0.008) and to die sooner (P = 0.0001) than control patients with CF. Environmental and microbiologic studies did not identify a common source or mode of transmission of P. cepacia among patients. The results of this investigation suggest that P. cepacia colonization of patients with CF was endemic in the hospital, occurred more frequently in those with severe disease, and was associated with adverse clinical outcome.

Adolescent↗
PubMed1985

HTLV-III/LAV antibody status of spouses and household contacts assisting in home infusion of hemophilia patients.

Thirty-four adult and pediatric hemophilia A and B patients and 50 nonhemophilic members belonging to 28 families were enrolled in August 1984 in a study of human T cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV) antibody status and T cell subpopulation numbers. All 50 household contacts, including three spouses of LAV antibody-positive adult hemophiliacs, were immunologically normal and serologically negative with respect to HTLV-III/LAV. Based on Western blot serologic testing of blood samples collected intermittently between July 1981 and August 1984 from 33 representative St Louis hemophiliacs studied during the period from 1981 to 1984, the average time since seroconversion was estimated as 20 months. One spouse of a seropositive hemophiliac and 23 parents of 27 seropositive pediatric hemophiliacs assisted regularly with home infusions. These infusion assistants have collectively experienced 44 person-years of concentrate infusion "exposure" without seroconversion. These results suggest that the likelihood for transmission of HTLV-III/LAV from hemophiliacs to persons assisting in their therapy is extremely low.

Acquired Immunodeficiency Syndrome↗
PubMed1984

In vitro cultivation of nonlymphoid thymic cells: morphological and immunological characterization.

Nonlymphoid thymic elements play an important role in T-lymphocyte development, especially in the development of recognition of transplantation antigens (H-2 in the mouse). Understanding this process will require the isolation and characterization of these cells. A simple technique for the culture of an enriched population of murine thymic epithelium is described. The epithelial nature of these cells is evidenced by their morphology, electron microscopy, and keratin content. Readily distinguishable macrophages comprise a secondary population within these cultures. Antigens encoded in the I-A region of H-2 were found on 70% of thymic epithelial cells and H-2K on 30% of thymic epithelial cells. These antigens were generally present on distinct populations but doubly positive cells were observed. Thymic macrophages were found to have conventional receptors for the Fc fragment of immunoglobulin on their surface and could ingest antibody-coated sheep erythrocytes. Thymic epithelial cells did not have such Fc receptors. A striking observation was that thymic epithelial cells could bind and internalize autologous thymocytes. This selective thymocyte ingestion by thymic epithelium may have important implications in regard to processing of T-lymphocyte precursors.

Animals↗
PubMed1984

Distinctive immunological properties of cultured murine thymic epithelial cells.

Skin painting with chemically reactive haptens induces a hapten-specific state of hypersensitivity that is long lasting and can be transferred to unirradiated recipient mice. A similar state of hapten-specific contact sensitivity can be induced by intravenous immunization with hapten-conjugated cells. Thus far, only two cell types have been described that can perform this function: Langerhans cells of the skin, and splenic dendritic cells. All other types, coupled with hapten, induce either tolerance or a short-lived state of contact hypersensitivity that is readily suppressed, and cannot be transferred to normal recipients. In the present experiments, it was demonstrated that culture-enriched, hapten-coupled thymic epithelial cells can also induce a state of stable contact hypersensitivity identical to that induced by skin painting. This provides evidence that thymic epithelial cells have distinctive properties as antigen-presenting cells in vivo. The relationship of this finding to the postulated role of thymic epithelium in T-cell development is discussed.

Animals↗
PubMed1979

Diagnostic considerations in ataxia-telangiectasia.

13 children with ataxia-telangiectasia were followed for 6 years. Unlike previously reported cases, these patients had progressive, debilitating neurological disease and slight pulmonary or infectious symptoms. Immunological dysfunction was variable and endocrinological defects were absent. Oculomotor findings, alpha-fetoprotein levels, and the incidence of chromosomal breakage were the most consistent parameters in the diagnosis of the condition. This disease should be considered in any patient with chronic ataxia, regardless of immunological findings or whether he has a history of infections.

Ataxia Telangiectasia↗
PubMedDate not supplied

Epidemiologic analysis of a cluster of homicides of children in Atlanta.

Between July 1, 1979, and March 15, 1981, there were 22 unsolved homicides and two unsolved disappearances of Atlanta children. Using epidemiologic methods, we attempted to identify factors that had put children at an increased risk of homicide. That all victims in this cluster were black, killed away from home, and that asphyxiation was overrepresented suggests that the cluster was discrete. The cluster was not homogeneous in relation to location of the victim's area of residence or location of the body; however, the median distance of 9.3 miles from home to body suggests that in some cases a motor vehicle was involved. A neighborhood-based study of the male victims and age- and sex-matched controls showed that victims more often ran errands for money (relative risk, 7.9) and were more often alone on the streets or in shopping centers; therefore, they may have been more approachable than other children in the neighborhood.

Adolescent↗