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Biomedical subjects

R K Oldham

Publications and source records attributed to R K Oldham.

At least 163 records · Page 9Linked to original sources
PubMed1983

Biological response modifiers.

It is clear that the rate of change in biology is rapidly accelerating. This is most apparent in the BRM area with respect to the development of new cancer therapies. New surgical approaches are being developed, and new forms of delivery for therapeutic radiation are now available. Radiosensitizers are now also being tested. Similarly, new chemotherapeutic agents and new methods of utilizing existing drugs are being developed. However, the use of BRM either alone or in combination with these other modalities is the area of greatest change and can be expected to be a major factor in achieving a greater understanding of cancer biology and a greater therapeutic specificity in the treatment of cancer patients in this decade (2, 65). Given the new technology of the 1980's, this is an exciting time. It is hoped that sufficient resources will be available to support continuing efforts to develop biologicals into effective anticancer agents. The rapidly advancing technologies of computers, cell fusion, and genetic engineering are all interrelated through the underpinnings of molecular biology to offer us unparalleled opportunities in biological research. These opportunities should translate into more effective treatments for cancer in this decade.

Adjuvants, Immunologic↗
PubMed1983

Guinea pig line 10 hepatocarcinoma model: characterization of monoclonal antibody and in vivo effect of unconjugated antibody and antibody conjugated to diphtheria toxin A chain.

Monoclonal antibodies were raised against the guinea pig line 10 (L10) hepatocarcinoma, and an IgG1-producing hybridoma (D3) was selected for further study. D3 is a true monoclonal antibody as demonstrated by two-dimensional gel electrophoresis. Radioimmunoassays on live cells revealed no cross-reactivity with normal tissues or with the line 1 hepatocarcinoma which was used as a control. Membrane immunofluorescence assays demonstrated similar specificity. Immunoperoxidase staining of cryostat sections of tumor and normal tissues of both adult animals and fetuses showed that the D3 monoclonal antibody reacted primarily with the L10 tumor, but some cross-reactivity with smooth muscle, placenta, fetal skeletal muscle, and fetal liver was also demonstrated. Radioimmunoprecipitation of detergent extracts of iodinated L10 cells showed that the antigen is present on the cell surface as a dimer of Mr 290,000 (unit size, Mr 148,000). Therapy studies with unconjugated D3 antibody demonstrated a minor dose-dependent effect on tumor growth. D3 antibody conjugated to the A chain of diphtheria toxin (10(-7) M) was cytotoxic to 100% of L10 cells in vitro. Animals treated with a single 1-mg i.v. injection of this immunoconjugate on Day 7 following the intradermal injection of 10(5) tumor cells demonstrated a highly significant inhibition of tumor growth compared to control animals and those treated with unconjugated antibody.

Animals↗
PubMed1983

Determination of the optimal human cell lines for development of human hybridomas.

Six human cell lines were compared with each other and with murine myeloma NS-1 as to their sensitivity to HAT medium and their ability to form hybrids with human lymphocytes, secret monoclonal immunoglobulin, clone, and maintain detectable levels of monoclonal immunoglobulin secretion for a period of time after fusion. Fusion efficiencies varied from 0 to 50%, and the incidence of immunoglobulin secretion ranged between 1 and 78% of the hybrids. Immunoglobulin secretion of cloned hybrids varied from 0.8 to 1.6 micrograms/ml/10(6) cells among the human-human hybrids and was 2.4 micrograms/ml/10(6) cells by the human-mouse hybrid. Among the lines tested, UC729-6 and HF2 appeared optimal for pursuing further studies with human-human hybridomas. In addition, although only a small percentage of hybrids were produced with HMy2, a very high percentage secreted immunoglobulin, so that this line also warrants further investigation to improve the efficiency of hybrid formation. Implications for specific monoclonal antibody production and for therapy of leukemias and lymphomas by anti-idiotype antibodies are discussed.

Animals↗
PubMed1983

Effects of recombinant interferon-alpha on immune function in cancer patients.

Patients with a variety of malignancies were treated in phase I clinical trials of recombinant leukocyte A interferon (IFL-rA) schedules consisting of either twice-daily doses for 28 days (48 patients) or three times weekly for 28 days (86 patients). Extensive monitoring of several immune functions was done on these patients, with rigorously standardized assays and determination of inherent variability of function for each individual. The assays performed were natural killer (NK) cell cytotoxicity, monocyte cytostatic activity, lymphoproliferative responses to concanavalin A (con A) and mixed leukocyte culture, and an analysis of changes in leukocyte populations as determined using a panel of monoclonal antibodies and flow cytometry. No appreciable increase in NK activity was observed on any of the treatment regimens, and an unexpected observation was the depression of activity in a substantial proportion (30%) of patients. In contrast, monocyte function, as measured in an assay of growth inhibition of tumor target cells, was found to be elevated in 70% of the patients. Lymphoproliferative responses were depressed in most patients in response to both con A and the mixed leukocyte culture. Cell surface marker studies revealed an increase in the percentage of OKT10 positive cells in the majority of patients studied and a transient increase in cells reacting with the antibody MO2. The data have been analyzed in terms of their relationship to dose and schedule of administration, and the depression of NK activity was shown to be greatest at the highest doses and more frequent schedule of administration.

Clinical Trials as Topic↗
PubMed1983

Changes in immune function in patients receiving natural leukocyte interferon.

Highly purified human lymphoblastoid interferon derived from virus-stimulated Namalwa cells was administered daily by 6-h i.v. infusion or i.m. injection to 40 patients with a variety of disseminated malignancies refractory to standard therapy. Each patient received escalating doses of 0.1-50 X 10(6) U for up to 5 weeks. Extensive monitoring for changes in various immune functions revealed no sustained elevation in natural killer cell activity, elevated monocyte-mediated antitumor cytostatic activity in approximately 30% of the patients, and depressed lymphoproliferative responses to mitogens and mixed leukocyte culture.

Cytotoxicity, Immunologic↗
PubMed1983

Depression of natural killer cytotoxicity after in vivo administration of recombinant leukocyte interferon.

One hundred thirty-four patients with a variety of malignancies were treated in two phase I clinical trials of recombinant leukocyte A interferon (IFL-rA) produced by recombinant DNA methodology. IFL-rA was given by intra-muscular injection either twice daily or three times weekly for 28 days. Extensive monitoring of natural killer (NK) cell cytotoxicity was done on these patients with rigorously standardized assays and determination of the inherent variability of NK function for each individual. Interferon, as used in these two treatment regimens, failed to produce an appreciable increase in NK activity; in the majority of patients, there was no significant change in NK activity from the pretreatment baseline levels. An unexpected finding was the depression of NK activity in 30% of the patients. The data have been analyzed in terms of their possible relationship to dose and schedules of IFL-rA administration and to antitumor response.

Analysis of Variance↗
PubMed1983

Localization of 111In- and 125I-labeled monoclonal antibody in guinea pigs bearing line 10 hepatocarcinoma tumors.

A murine monoclonal antibody (D3) with demonstrated specificity for the guinea pig line 10 hepatocarcinoma (L10) was radiolabeled with either 125I or 111In and used to image dermal tumors in vivo. In one set of experiments, L10 tumors were established middorsally in one group of animals, and the similarly derived, antigenically distinct line 1 tumor was established in another group of animals. In spite of background imaging of liver, kidney, and spleen, L10 tumors were visualized clearly. Incorporation of radiolabel was demonstrated to predominate in the L10 tumor. In a separate set of experiments, L10 and line 1 tumors were established in contralateral thighs in the same animals. L10 tumors were visualized clearly, and tissue uptake of radiolabel was demonstrated to reside predominantly in the L10 tumor.

Animals↗
PubMed1982

A multiple-dose phase I trial of recombinant leukocyte A interferon in cancer patients.

Eighty-one patients with a variety of refractory disseminated malignant neoplasms have been treated in the first multiple fixed-dose phase I trial of recombinant leukocyte A interferon (IFL-rA). Each patient received IFL-rA by intramuscular injection, three times weekly for 28 days. Dosages were escalated in different patients from 1 to 136 x 10(6) units per injection. The toxic reactions seen with IFL-rA resembled those of nonrecombinant leukocyte interferon and included fever, chills, fatigue, anorexia, myalgia, headache, occasional nausea and vomiting, and dose-dependent reversible leukopenia and hepatic transaminase elevations. The pharmacokinetics of IFL-rA were also comparable with nonrecombinant leukocyte interferon. Objective evidence of antitumor activity was seen in non-Hodgkin's lymphoma, chronic lymphocytic leukemia, Hodgkin's disease, breast cancer, and melanoma, indicating that IFL-rA, the first genetically engineered biological response modifier available for testing in cancer patients, is biologically active in vivo.

Anorexia↗
PubMed1982

Endodermal sinus tumor of the mediastinum.

Endodermal sinus tumor (EST) of the mediastinum is a rare germ-cell neoplasm affecting mainly young adult males. Ten patients with EST were treated with a multimodality approach that included surgery, chemotherapy, and radiotherapy. All patients had relapses after achieving a transient response except one who is still in complete remission more than five years following the diagnosis of the disease. Optimal therapy for this neoplasm has yet to be discovered. The disease is a subset of extragonadal germ cell tumors which appears to be lethal in most cases, particularly when the primary tumor is unresectable. The first case of five-year disease-free survival is described.

Adolescent↗
PubMed1982

Immunological studies in a double blind randomized trial comparing intrapleural BCG against placebo in patients with resected stage I non-small cell lung cancer.

Immunological data were obtained during the course of a randomized trial comparing intrapleural BCG plus oral isoniazid (INH) with intrapleural saline plus oral placebo after resection of stage I non-small cell lung cancer. Immunological testing with a variety of assays was carried out with good standardization among six collaborating laboratories and with good reproducibility within each laboratory. Those patients with larger tumors tended to have higher initial white cell counts. The percentage of lymphocytes in the differential was greatest in those with non-squamous cancer histology. Otherwise, no associations were found between initial immunologic parameters and baseline variables. The main effect of BCG/INH therapy was to cause statistically significant increases in purified protein derivative (PPD) skin test induration and PPD in vitro blastogenesis compared with controls. Other skin tests and in vitro assays increased more in the saline/placebo control group, but these treatment differences were usually not statistically significant. Initial white count and neutrophil count elevations were found to be associated with increased risk of recurrence. Even after adjustment for treatment and tumor stage, initial neutrophil count elevation was associated with increased risk of recurrence. Surprisingly, a low 29 degrees C T cell rosette index was associated with a decreased risk of recurrence, though the differences were minimal. Serial immunological tests were carried out to evaluate their potential for monitoring disease recurrence. White count elevations continued to be significantly associated with increased risk of recurrence, but more follow-up data are needed before other associations can be assessed.

BCG Vaccine↗
PubMed1982

Randomized study of high-dose versus low-dose methotrexate in the treatment of extensive small cell lung cancer.

Forty patients with extensive small cell lung cancer randomly received either high-dose or low-dose methotrexate with leucovorin rescue in combination with cycles of cyclophosphamide, doxorubicin, and vincristine alternating with cycles of VP-16, vincristine, and hexamethylmelamine. Nineteen patients were treated with the high-dose methotrexate regimen, and 21 received the low-dose methotrexate treatment protocol; both treatment groups were similar in median age, performance status and spread of disease. Response rates (74 percent for high-dose therapy; 67 percent for low-dose therapy), median survival (nine months versus nine months), and overall survival were similar for the two treatment groups. Myelosuppression was equivalent in both treatment groups but moderate to severe mucositis developed more often when patients were treated with the high-dose methotrexate regimen as compared with low-dose methotrexate therapy (p less than 0.001). Central nervous system recurrences developed after three patients received high-dose methotrexate therapy. This study indicates that when used with other antineoplastic agents, high-dose methotrexate therapy does not improve the remission rate or survival nor does it decrease central nervous system metastasis in patients with small cell lung cancer when compared with standard doses of methotrexate; high-dose methotrexate is associated with greater cost and toxicity.

Carcinoma, Small Cell↗