Biomedical subjects

V D Miletic

Publications and source records attributed to V D Miletic.

3 recordsLinked to original sources

PubMed1995

Complement-immunoglobulin interactions.

Normal circulating immunoglobulin may control complement binding to targets and thereby the manifestations of autoimmune disease. Molecular analysis of IgG and IgM mutants suggests that C1q binding by IgG utilizes a core Glu-X-Lys-X-Lys motif (where X is any amino acid). Additional amino acids, particularly homologous proline residues at position 331 in IgG and 436 in IgM, appear critical for classical pathway initiation. Glycosylation of IgG heavy chain is important in C1q binding, as well as glycosylation of IgA heavy chain for alternative pathway initiation. Additional recent evidence suggests an important role for C3 in antigen presentation. The data also raise the possibility that C3 plays a significant role in the intracellular antigen processing pathway.

Animals↗

PubMed1994

Identification of gliadin presence in pharmaceutical products.

Celiac disease is characterized by hypersensitivity to the alcohol-soluble wheat proteins called gliadins. Total avoidance of gliadin is the lifelong treatment for such patients. However, wheat gliadins are often present as impurities in industrial starch commonly used in the preparation of different pharmaceutical products. Therefore, some drugs might contain gliadin, which can be dangerous for sensitive patients if taken in large amounts or used permanently. The purpose of this study was to develop a sensitive, reliable assay that is specific for the detection of gliadins in pharmaceutical products. Gliadins were extracted here using sodium dodecyl sulfate rather than 70% ethyl alcohol, which has been the traditional solvent. This gliadin extract was utilized in a dot-blot assay that incorporated an antigliadin antibody developed in rabbit and labeled with peroxidase. 4-Chloro-1-naphthol was used as a peroxidase-specific substrate. Isolated wheat gliadin was used as the positive control. Dilution experiments showed that the lower level of sensitivity for the assay was in the range of 0.0045 mg/ml of gliadin, which is a concentration level lower than that suggested for a gluten-free diet. The assay developed here revealed that 71.2% of 59 prescription and nonprescription drugs tested contained gliadin in the amount detected by our dot-blot assay. The prescription drugs tested were among the top 50 most frequently dispensed in U.S. community pharmacies. The nonprescription drugs were among those that constitute the largest sales in the United States. The results showed that the simple dot-blot assay developed here can be used for pharmaceutical testing performed either by hospital laboratories or by patients themselves.

Blotting, Western↗

PubMed1993

Complement activation in stored platelet concentrates.

Activation of platelets during preparation and/or storage of platelet concentrates in plastic containers at room temperature has recently been recognized. Many different biologic causes of this activation have been postulated. Activated complement, as a multi-enzyme system, is one of the possible sources of molecules leading to platelet activation. To detect complement activation, functional complement activity and the generation of complement-derived ligands were investigated in platelet concentrate supernatant plasma during 5 days of storage at room temperature. Hemolytic tests for functional classical and alternative pathway activity were used, as was the kinetic test for complement-mediated inhibition of immune complex precipitation. The presence of C3 activation products (C3, C3c, C3dg) was investigated in plasma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting procedures and on platelets by immunofluorescence. Activation of complement was evident during storage, and C3c and C3d fragments were clearly demonstrated in plasma. The amount of C3d fragments on platelets gradually rose during the first 3 days of storage. At the end of 5 days of storage, the platelets became C3d negative. There are two possible mechanisms of C3d disappearance--shedding and/or further degradation of C3d fragments. Those results indicated that complement activation and the generation of complement-dependent ligand-receptor interaction may be mechanisms for platelet activation in concentrates stored at room temperature.

Binding Sites, Antibody↗