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Biomedical subjects

G Pearson

Publications and source records attributed to G Pearson.

At least 109 records · Page 6Linked to original sources
PubMed1970

Differential reactivity of human serums with early antigens induced by Epstein-Barr virus.

Inoculation of 64-10 or Raji cultures with Epstein-Barr virus derived from the HRI-K clone of the P3J Burkitt's lymphoma line caused abortive infections in most of the lymphoblastoid cells with synthesis of "early antigens" but few, if any, capsids. Antibodies to early antigens were detected by indirect immunofluorescence in serums of many patients with infectious mononucleosis, Burkitt's lymphoma, or nasopharyngeal carcinoma. These antibodies were rarely present in other serums even though some of them showed high titers of antibodies to Epstein-Barr virus when assayed on EB3 Burkitt tumor cells; they also prevented synthesis of early antigens, provided the serums were mixed with the virus prior to inoculation. Antibodies to early antigens possibly reflect current or recent disease processes that are associated with the virus.

Antigen-Antibody Reactions↗
PubMed1969

Relation between Epstein-Barr viral and cell membrane immunofluorescence in Burkitt tumor cells. 3. Comparison of blocking of direct membrane immunofluorescence and anti-EBV reactivities of different sera.

Sera from patients with Burkitt's lymphoma (BL), infectious mononucleosis (IM), carcinoma of the postnasal space (Ca PNS), and various controls were investigated for antibodies against the Epstein-Barr virus (EBV) by immunofluorescence on acetone-fixed smears (5) and for antibodies against the distinctive antigenic sites expressed on the surface of viable lymphoblastoid cells within EBV-carrying culture lines (1). The latter were studied by the blocking of direct membrane staining with FITC-conjugated Mutua serum. This serum has been derived from a Burkitt's lymphoma patient in long-term regression after chemotherapy and is free from detectable isoantibodies. It has been used previously as a standard of reference to demonstrate the presence of the membrane antigen(s) on all lines derived from BL biopsies and leukocytes from IM patients. It was found that 102 of 279 (37%) of the sera tested had high anti-EBV titers (>==80) and high membrane-blocking (Bl > 0.5) activity, 124 of 279 (44%) of the sera were low in both tests, 22 of 279 (8%) had low EBV titers (<==80), in spite of a high blocking index, and 31 of 279 (11%) of the sera were low in blocking activity (<0.5), in spite of a high EBV titer. The two tests thus gave concordant results with 81% and discordant with 19% of the sera. The majority of sera from BL patients were high in both tests. IM sera also showed a relationship between the two antibody activities but, in general, both activities were lower than in BL cases. Ca PNS sera seemed to fall into two main groups: (a) high anti-EBV, high blocking or (b) low anti-EBV, low blocking. Control sera, including four isoantisera, showed predominantly low reactivities in both tests.

Antigens↗
PubMed1969

Relation between Epstein-Barr viral and cell membrane immunofluorescence in Burkitt tumor cells. IV. Differentiation between antibodies responsible for membrane and viral immunofluorescence.

Previous reports (1, 2) have established that the expression of certain distinctive membrane antigen(s) on the surface of Burkitt's lymphoma (BL) and infectious mononucleosis (IM) cells is dependent on the presence of Epstein-Barr virus (EBV) in the cell line. The investigations reported here provide evidence that antibodies directed against EBV antigens, as revealed by the immunofluorescence test on acetone-fixed smears (8), and the membrane reactive antibodies, although often present in the same serum, are nevertheless distinctly different. Absorption of Mutua serum, the standard reference serum for demonstrating membrane antigen(s) on BL and IM cells, with BL cells completely removed anti-membrane activity without significantly affecting the anti-EBV antibody titer. Furthermore, sera were found which contained one type of antibody but not the other. Sera with high anti-membrane but low anti-EBV activity were found among relatives of BL patients. These sera reacted with the membranes of EBV-carrying BL and IM cells in essentially the same way, i.e., against the same spectrum of target cells, as the EBV-positive Mutua serum. They were unable to block the membrane reactivity of FITC-conjugated Mutua serum, however. In some cases they showed weak but incomplete blocking. One such EBV-negative, membrane-positive BL relative serum (Robert) was conjugated with FITC and used for direct staining of BL and IM cells. Again, this conjugate reacted against the same target cell spectrum as a Mutua conjugate, but its reactivity was completely blocked by a number of Burkitt patients' sera, although unconjugated Robert serum did not block the Mutua-conjugate. A number of other membrane-positive BL relative sera also failed to block Mutua, but completely blocked the Robert conjugate. A number of Swedish and African control sera and an isoantiserum gave no blocking against Robert conjugate. It therefore appears that the Mutua conjugate contains at least two antibody specificities against the EBV-determined membrane antigens. One, but not the other, is shared with the antibody specificity present in Robert's serum and a number of other sera from relatives of BL patients.

Antigens↗
PubMed1968

Relation between Epstein-Barr viral and cell membrane immunofluorescence of Burkitt tumor cells. I. Dependence of cell membrane immunofluorescence on presence of EB virus.

A comparison was made of the immunofluorescence tests for detection of cell membrane and Epstein-Barr virus antigens in cells from Burkitt tumor biopsies or continuous cultures derived therefrom. On the whole, cell membrane fluorescence in established lines appeared to depend not only upon the presence of EBV but to a considerable degree also upon the extent of the persistent viral infection. There was no constant relationship, however, between the results of the two tests and exceptions to the rule were noted. These observations indicate that different antigens are involved in the two tests. Biopsy cells in general and young cultures may reveal strong MIF activity but few, if any, EBV-positive cells. The reverse, the presence of relatively large numbers of EBV antigen-containing cells in the absence of significant MIF reactions, was also noted on occasion in a few established cultures. The possible interpretations of these findings have been discussed.

Antigens↗
PubMed1968

Relation between Epstein-- Barr viral and cell membrane immunofluorescence in Burkitt tumor cells. II. Comparison of cells and sera from patients with Burkitt's lymphoma and infectious mononucleosis.

Blastoid cell cultures derived from leukocytes of patients in the acute stage of infectious mononucleosis (IM) and harboring Epstein-Barr (EB) virus in at least 1% of the cells were found to possess antigens in their membranes which presently are indistinguishable from those detected in Burkitt's lymphoma (BL) cells by the techniques employed. It was noted that, in the course of IM, antibodies are formed which react in indirect immunofluorescence tests with membrane antigens of live cells from Burkitt tumor lines as well as from IM leukocyte cultures, including an autochthonous line in the case of one patient. Sets of sera from IM patients were tested which included a serum collected weeks to years before onset of illness. In the majority of these the pre-IM serum failed to react in membrane immunofluorescence (MIF) tests with any of several Burkitt tumor cell lines employed, but in some cases the presera reacted with cells of some but not others of the lines. Possible explanations for these discrepant results have been discussed. The antibodies involved in the MIF test are evidently distinct from those responsible for the EBV and heterophile reactions. Maximal MIF activity is attained long after the other two antibodies have reached maximal titers and antibodies to EBV and membrane antigens seem to persist for years whereas the heterophile reaction turns negative within a few months.

Antibodies↗
PubMedDate not supplied

Nuclear magnetic resonance spectroscopy of plasma for the detection of head and neck cancer.

The plasma of 15 normal volunteers, four patients with benign head and neck disease, and 12 patients with biopsy proven head and neck malignancies were evaluated using water-suppressed nuclear magnetic resonance (NMR) spectroscopy. While the mean full width at half height (HHLW) of the NMR spectra showed a significant difference between groups (P less than .05), the predictive value of a positive test was only 57% the sensitivity was only 33%, and individual values in all groups demonstrated considerable overlap. The mean HHLW of the control group was 38.5 Hz +/- 3.5 compared with 35.2 Hz +/- 4.7 for the cancer group and 35.0 Hz +/- 10 for the benign disease group. This method was not able to distinguish patients with malignancy from those with benign disease or controls. Its use as a specific screening method for head and neck malignancy cannot be recommended.

Adult↗
PubMedDate not supplied

Restorative index.

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DMF Index↗
PubMedDate not supplied

Nurses, physicians, and pharmacists: their knowledge of hazards of medications.

At a major tertiary care teaching hospital, random samples of 100 nurses, 102 physicians, and all of the hospital's 14 pharmacists were tested on their knowledge of the hazards of medications. The 25-question examination was generated by way of a rigorous validating procedure and was self-administered by the practitioners. Based on a perfect examination score of 100, the group mean scores of the nurses, physicians, and pharmacists were 72.3, 81.3 and 85.1, respectively. A one-way analysis of variance demonstrated that the difference in knowledge among the three groups of practitioners was significant (p less than .001). Pairwise (Scheffe) contrast tests revealed that the difference in knowledge between the physicians and nurses, and the pharmacists and nurses was significant; the nurses proved to be the least knowledgeable of the three practitioner groups. The nurses' scores were analyzed by years of nursing experience, type of educational preparation, hospital service affiliation, and hospital shift. A one-way analysis of variance revealed that there was a significant difference in nurses: knowledge by hospital shift (p less than .05). A posteriori contrast tests (Scheffe) indicated that the group mean score of the day shift nurses (mean = 75.6) was significantly different than the average of the evening and night shift nurses' scores (mean = 69.9).

Cognition↗