Search PubMedSearch

Biomedical subjects

R Dowling

Publications and source records attributed to R Dowling.

10 recordsLinked to original sources

HLA-class II antigen expression in human heart-lung allografts.

Long-term survival in heart-lung transplantation has ben hindered by the development of bronchiolitis obliterans (OB), which is believed to be a manifestation of chronic rejection of the lung. Since HLA-class II antigens are involved in the rejection response, the distribution of the class II products HLA-DR, HLA-DQ, and HLA-DP were studied in normal lung, and in transplanted lung with and without OB, utilizing frozen-section immunohistochemical techniques. All three allelic products are usually expressed on the epithelial, endothelial, and mesenchymal components of the lung. Sequential transbronchial biopsies from 4 recipients before and concurrent with the diagnosis of OB were stained with serial dilutions of monoclonal antibodies to assess the level of expression of the above class II products. Increased levels of HLA-DR and HLA-DP antigens may be seen on the bronchial and bronchiolar epithelium during OB, but the changes are subtle and complicated by many other variables. Additional studies are needed to confirm these preliminary results.

Bronchiolitis Obliterans

Magnetic resonance imaging in posterior circulation infarction: impact on diagnosis and management.

To compare the diagnostic yield of magnetic resonance imaging (MRI) with computed tomography (CT) in posterior circulation infarction, we used proton MRI with a 0.3 Tesla magnet and a 3rd generation CT scanner in 25 patients. Age-matched controls were compared in a blinded fashion. Seventeen patients (68%) showed relevant pathology on MRI not seen on CT, 11 with normal CT and six with more extensive lesions, chiefly in the brain stem. Evidence of abnormal vertebrobasilar blood flow was seen in 8/25 (32%) of patients, suggested by vascular high intensity signals on MRI. Two tissue and one flow abnormality were seen in the control group. MRI provides additional information concerning infarct site, extent and pathogenesis in posterior circulation infarction.

Adult

Mononuclear cell collection using various techniques.

During the last 15 months, 609 mononuclear cell collections were performed. Lymphocytapheresis and monocytapheresis provides cells for in vitro research studies, investigational transfusion studies and as therapeutic procedures. Automated leukapheresis procedures yields from 1.0-1.5 X 10(9) lymphocytes per liter blood processed. Monocyte yields generally 1/10 of the lymphocyte yields in both lymphocytapheresis and monocytapheresis procedures. Donors had very few reactions, and post collection CBC's showed no significant abnormalities. Mononuclear cell donation appears to have no risk to the normal donor.

Blood Donors

Phase I trial of Staphylococcus aureus Cowan I immunoperfusion.

Staphylococcus aureus Cowan I has shown antitumor activity in in vitro and in animal tumor models. It is hypothesized that this antineoplastic effect results from the interaction of protein A on the cell surface of Cowan I strain S. aureus and immunosuppressive circulating immune complexes. Therefore, we treated five patients with ex vivo plasma immuno-perfusion over killed and fixed S. aureus Cowan I. Toxic effects were marked in all patients and appeared to be related to the plasma volume infused and rate of infusion. Toxic reactions occurred in the cardiovascular, respiratory, and hematopoietic systems. No responses even minimal or transient, were observed in this phase I trial. This toxicity may be reduced if the rate of plasma infusion decreases.

Adult

Use of in vitro assays in selection of compatible platelet donors.

Although HLA-matched platelet transfusions are of value in the support of some alloimmunized thrombocytopenic patients, poor posttransfusion increments can be observed following HLA-matched platelet transfusions and conversely good posttransfusion increments may result after HLA-mismatched platelet transfusions. We have explored the possibility that in vitro assays in addition to HLA typing might better select compatible donors for refractory recipients. Our studies suggested that a platelet migration inhibition assay is predictive of platelet transfusion responses in HLA-compatible and incompatible donor-recipient pairs, while lymphocytotoxicity is predictive of posttransfusion increments only in HLA-incompatible donor-recipient pairs. Granulocytotoxicity, microleukoagglutination, and capillary leukoagglutination showed no value in predicting platelet transfusion increments, either in HLA-compatible or incompatible donor-recipient pairs.

Anemia, Aplastic