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Biomedical subjects

S P O'Neill

Publications and source records attributed to S P O'Neill.

14 recordsLinked to original sources
PubMed1991

Large-scale purification of inactivated hepatitis A virus by centrifugation in non-ionic gradients.

Formalin-inactivated hepatitis A virus (HAV) can be purified for vaccine preparation by centrifugation in Renografin-76 (diatrizoate meglumine and diatrizoate sodium) gradients. Both continuous-flow rate-zonal and isopycnic methods were used for the separation of a major antigen component from minor antigen and host protein. The major antigen component, which appeared to contain complete virions by electron microscopy, could be recovered from gradients and accounted for approximately one third of the total antigen in the starting material. The HAV-specific purified antigen could be enriched 200-300-fold by either centrifugation procedure. The purified HAV antigen, when adsorbed to alum and inoculated into mice, was found to be highly immunogenic.

Antigens, Viral↗
PubMed1985

Identification and typing of herpes simplex virus types 1 and 2 by monoclonal antibodies, sensitivity to the drug (E)-5-(2-bromovinyl)-2'-deoxyuridine, and restriction endonuclease analysis of viral DNA.

With development of antiviral drugs, the need to identify a virus as to drug sensitivity becomes increasingly of importance. The compound (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) has been shown to be much more inhibitory to the replication of herpes simplex virus type 1 (HSV-1) and varicella-zoster virus as opposed to herpes simplex virus type 2 (HSV-2). We have typed over 170 isolates, using an immunofluorescent technique and sensitivity to the drug BVDU. These results were then compared to the typing of isolates by analysis of viral DNA after restriction endonuclease digestion (EcoRI). Without exception the results were in agreement between the monoclonal antibody results and sensitivity to the drug BVDU. Furthermore, the typing with monoclonal antibodies was also in excellent agreement with the DNA analysis. Only those isolates inhibited with BVDU showed DNA characteristics of HSV-1 and reacted only with the S-200 antibody. On the other hand, those isolates which reacted with the monoclonal antibody S-141 were insensitive to BVDU, and again this was in agreement with the DNA analysis. These results could provide the basis for developing a diagnostic test using the two monoclonal antibodies to type either isolates or direct smears and to use the results as a basis for possible drug therapy.

Antibodies, Monoclonal↗
PubMed1983

Quantitation of haptens by homogeneous immunoprecipitation. 2. Centrifugal analysis for tobramycin, phenobarbital, and theophylline in serum.

Our homogeneous immunoprecipitation inhibition assay (Clin. Chem. 28:659-661, 1982) is applied here to tobramycin, phenobarbital, and theophylline. Only 10-50 microL of test sample is needed. No sample treatment, dilution, or extraction is required. A test serum sample is simultaneously mixed with a drug conjugate and its specific antiserum in a centrifugal analyzer. The subsequent reaction and the measurement are completed in 3 min. Within-run and between-run CVs for clinically relevant concentrations were well below 10%. Results for patients' samples correlated well with those by enzyme immunoassay.

Anti-Bacterial Agents↗
PubMed1982

Quantitation of haptens by homogeneous immunoprecipitation. 1. Automated analysis of gentamicin in serum.

A new homogeneous immunoprecipitation inhibition assay has been developed to quantitate concentrations of hapten in human serum or plasma without the use of radioactive isotopes, enzymes, fluorescent markers, or laser nephelometers. This immunoprecipitation is based on spectrophotometric measurement of the inhibition by free hapten of the precipitating reaction between antihapten antibody and polyhaptenic antigen. The immunoprecipitation analysis of the antibiotic gentamicin in human serum is reported here. A serum test sample is mixed with gentamicin-human serum albumin polyhaptenic conjugate and rabbit antiserum to gentamicin on a centrifugal analyzer, and the subsequent reaction monitored for 3 min. No sample dilution or pretreatment is required. The within-run and between-run coefficients of variation are well below 10%. The results on patients' test samples correlate well with those obtained by commercially available radioimmunoassay and enzyme immunoassay kits.

Antigen-Antibody Complex↗
PubMed1982

Homogeneous nonisotopic assay for phenytoin evaluated.

We evaluated a new homogeneous immunoprecipitation assay for phenytoin in human serum. No sample dilution or pretreatment is required. The new method is based on spectrophotometry of the inhibition by free phenytoin of the precipitating reaction between anti-phenytoin antibody and a phenytoin-human serum albumin conjugate. A serum test sample is simultaneously mixed with the phenytoin-albumin conjugate and rabbit antiserum to phenytoin in a centrifugal analyzer, and the subsequent reaction is monitored at 3 min. Within-run and between-run coefficients of variation were well below 7%. The relation between results for patients' test sample as determined by immunoprecipitation assay (y) and an enzyme immunoassay (x) can be expressed as y = 1.10x + 1.1 (r = 0.966, n = 66).

Evaluation Studies as Topic↗
PubMed1979

Interaction of hepatitis B surface antigen with polymerized human serum albumin.

HBsAg binds to a solid-phase adsorbent consisting of polymerized human serum albumin (HSA) on glass particles. Both AD and AY antigenic subtypes of hepatitis B surface antigen (HBsAg) display this interaction. In either case, the binding to polymerized HSA is reduced in the presence of human serum, suggesting significant attachment of serum components at the locations on HBsAg particles where polymerized HSA binds. The temperature dependence of the interaction goes through a maximum above room temperature, in contrast to the increasing reaction with temperature of the HBsAg--anti-HBs antibody system. The interaction between HBsAg and polymerized HSA is discussed in relation to previous findings of HSA polymers and anti-polymerized albumin antibodies in hepatic patients. A mechanism for production of an autoimmune, antialbumin antibody condition, in association with hepatitis B virus infection is proposed.

Antibody Specificity↗
PubMed1978

Radioimmunoassay for hepatitis B surface antigen and antibody using a two-component immunoadsorbent.

A solid-phase radioimmunoassay is described for detection of hepatitis B surface antigen and antibody. The assay uses a two-site (antigen and antibody) immunoadsorbent capable of binding antigen and antibody. Antigen is detected by enhanced binding of [125U]antibody through sandwich formations of antibody--antigens--[125I]antibody on the immunoadsorbent. Antibody presence is revealed by inhibition of [125I]antibody binding.

Antibodies, Viral↗
PubMed1976

Hapten concentrations in the circulation of animals actively immunized with hapten-protein conjugates.

Animals immunized with hapten-protein conjugates subsequently circulate high concentrations of hapten bound by antibody. The levels of hapten detected are capable of significantly reducing antibody titer in the sera immunized animals. In the case of steroid-protein conjugates, the main source of increased plasma steroid concentration is the immunizing conjugate, although a contribution from increased host secretion may also occur. The results for rabbits immunized with digoxin-BSA indicate that the appearance of circulating digoxin followed the appearance of circulating antibody to digoxin. Appearance of digoxin in circulation appears to coincide with the operation of the immune response and may be related to macrophage activity. Similar conclusions are drawn from results obtained for circulating morphine in the serum of a sheep immunized with morphine-BSA. Injected hapten-protein antigens are probably processed by macrophage to produce low molecular weight haptenic fragments which are maintained in circulation for prolonged periods in the form of antibody-hapten complexes.

Animals↗