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Biomedical subjects

R Harris

Publications and source records attributed to R Harris.

At least 595 records · Page 33Linked to original sources
PubMed1973

Active immunotherapy used alone for maintenance of patients with acute myeloid leukaemia.

A total of 32 patients suffering from acute myeloid leukaemia were initially treated with daunorubicin and cytosine arabinoside, and eight who achieved full remission were given a brief cytoreduction course of cyclophosphamide and thioguanine. Of these eight patients seven were then actively immunized with 10 irradiated allogeneic acute myeloid leukaemia cells and B.C.G. at weekly intervals. Six of these patients have survived in apparent good health for more than one year. Bone marrow changes suggestive of relapse were used as an indication for further short courses of chemotherapy, and except on single occasions in two different patients clinical relapse has been prevented. The average duration of first (bone marrow) remission appears to be comparable with the best achieved in trials using regular chemotherapy for maintenance, though criteria for determining relapse may be different. The rate of reinduction of remissions (bone marrow) in this series was high, with a subsequent increase in overall survival time. Possible explanations for the high rate of reinduction include, firstly, the effects of active immunization with specific leukaemia antigen; secondly, non-specific adjuvant effect; thirdly, avoidance of drug resistance; and, fourthly, early diagnosis of relapse by frequent bone marrow examinations.

Adolescent↗
PubMed1973

Immunological studies in acute myeloid leukaemia: PHA responsiveness and serum inhibitory factors.

Sera from 16 of 20 patients with AML at some stage of the disease inhibited the in vitro PHA transformation of normal lymphocytes assessed by measuring the rate of DNA synthesis after 67-70 hours; 42% of pretreatment sera were inhibitory. Inhibitory activity was overcome at PHA concentrations 2-3 times greater than the concentration which allowed maximum discrimination between NHS and leukaemia sera.PHA transformation of washed lymphocytes obtained from AML patients before treatment and when receiving induction or consolidation (cytoreductive) chemotherapy was reduced only when cultures contained a high proportion of primitive cells. Even in primitive cell contaminated cultures significant responses to PHA could be measured if conditions were modified to prevent increasing acidity.Reports of reduced in vitro immunological reactions in pretreatment and poor prognosis patients may therefore be due to the presence of primitive cells in culture, and in treated patients to the failure of chemotherapy to reduce the circulating primitive cell count. Serum inhibitory factors may have a significant immunosuppressive effect in vivo, but the accurate assessment of the role of immune mechanisms in AML should attempt the measurement of specific immunity.

Culture Techniques↗