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J T Casper

Publications and source records attributed to J T Casper.

At least 73 records · Page 4Linked to original sources
PubMed1983

Prospective clinical trial of a human tumor cloning system.

A prospective clinical trial was performed to evaluate the usefulness of a human tumor cloning system for selecting single-agent chemotherapy for patients with advanced cancers. Six hundred four single-agent trials were performed in the 470 patients whose tumors were submitted for drug sensitivity testing. Only 246 of these 604 trials (41%) could be directed by the cloning system results because of inadequate tumor growth and other difficulties. In these 246 prospective trials, there was a 60% true positive and an 85% true negative rate for predicting for response or lack of response of an individual patient's tumor to the single agent. There was also a relationship between the percentage of decrease in survival of tumor colony-forming units and the probability of a clinical response of the patient's tumor to the same drug used in vivo. Despite these encouraging findings, work to improve tumor growth and additional prospective clinical trials of the system are needed before the system can be recommended for routine clinical use.

Breast Neoplasms↗
PubMed1983

In vitro enhancement of peripheral blood mononuclear cell natural killer activity following short term incubation with fetal calf serum.

This study demonstrates that short term incubation of blood mononuclear cells (MC) in heterologous sera enhances their natural killer (NK) but not their antibody dependent killer (K) activity, and confirms that NK stimulation is not related to blastogenesis. MC were obtained from healthy donors and incubated with RPMI 1640 supplemented with various serum sources. NK and K activity of incubated vs. fresh MC against SK-N-SH, Chang or Raji cell line targets were compared in a 4-hr 51Cr release assay. A significant (p less 0.01) increase in NK cytotoxicity was detected when MC were incubated with fetal calf serum (FCS) or human AB serum (ABS) at 37 degrees C. When a more sensitive NK target cell (K-562) was used only the cells incubated in FCS demonstrated increased NK cytotoxicity. Augmentation of NK cell activity by FCS was not related to blastogenesis, mitosis, natural antibodies against lymphocytes or target cells, immunoglobulin complexes or alterations in MC OKT4 and OKT8 subpopulations. In contrast to NK activity, K cytotoxicity was not increased after incubation at 37 degrees C in FCS or ABS, and it was depressed in IPT (p less than 0.05). Thus FCS is capable of stimulating NK cell activity against human tumor cell lines in less in less than 24 hr.

Animals↗
PubMed1982

Association between HLA-D region antigens and disease-free survival in childhood non-T, non-B acute lymphocytic leukemia.

The frequency of three serologically defined HLA-D region antigens--DR, MB, and MT--was determined in a group of 74 children with non-T, non-B acute lymphocytic leukemia (ALL). Statistically, there were no significant differences in the frequency of any antigen in these ALL patients as compared with a panel of 85 normal controls. However, significant differences in HLA-DR frequencies were observed between patients who relapsed or who remained disease-free during a 30-mo period of chemotherapy. An increased incidence of relapse was associated with DR5, while disease-free remission during chemotherapy was associated with DR7. Life table analysis also demonstrated that DR5 was significantly associated with a decrease in disease-free survival in these patients. These data suggest that HLA-associated genetic factors may influence the responses of ALL patients to chemotherapy.

Adolescent↗
PubMed1979

99mTc-methylene diphosphonate imaging in neural crest tumors.

Thirteen patients with neural crest tumors were each studied with a radionuclide skeletal survey, a radiographic skeletal survey, and an iliac crest bone marrow aspiration. The RN skeletal survey proved to be more accurate that the radiographic skeletal survey in: 1) detecting the primary tumor; 2) demonstrating bony metastatic disease; and 3) evaluating response to therapy. The overall accuracy of the RN skeletal survey in detecting metastatic disease correlated with the results of bone marrow aspiration both in the initial detection of metastatic disease and the evaluation of response during therapy.

Bone Neoplasms↗
PubMed1979

Shifts in expression of cell membrane phenotypes in childhood lymphoid malignancies at relapse.

To determine if cell membrane phenotypes change under the selective pressures of therapy we have conducted a prospective study of 54 children with lymphoid malignancies of T-like, B-like, common, and null cell types. Membrane phenotypes were determined at diagnosis in all patients and again 1-24 mo later in 18 children who either failed induction therapy or had one or more relapses. In 7 patients the cells tested were from relapse sites different than those of the original diagnoses. The data indicate that at relapse most children with lymphoid neoplasias had the same cell membrane phenotype as established at diagnosis, and suggest that the site of relapse did not affect the expression of cell surface markers. However, there were three exceptions: (1) a child initially diagnosed as having null cell acute lymphocytic leukemia had 90% T-antigen-positive blasts in her second-relapse bone marrow; (2) only membrane IgM was present on relapse blasts from a B-cell lymphoma that had both membrane IgM and IgD before initiation of treatment; (3) at diagnosis, bone marrow blasts from a child with T-like leukemia expressed both T antigen and E receptors, but at relapse, bone marrow and pleural fluid cells expressed only T antigens. We postulate that these phenotype shifts may be due to selective effects of therapy on cells at different stages of differentiattion.

Adolescent↗
PubMed1977

Computerized evaluation of electroencephalographic changes accompanying exchange transfusion in Reye's syndrome.

The EEGs of 7 children with Reye's syndrome (fatty liver and encephalopathy) were continuously recorded on magnetic tape for times ranging from 12 to 80 h. During these times the major therapy consisted of exchange blood transfusions. The tapes were automatically processed on a LINC-8 computer using a peak-detection algorithm. The main parameters investigated were the delta and theta indices, the mean EEG frequency, the mean peak-to-peak amplitude, and the frequency versus amplitude characteristics of the delta waves. In 5 patients who responded to therapy, a marked decrease in the delta activity and an increase in mean frequency were noted subsequent to exchange transfusions. In all 5 cases the delta waves exhibited a similar pattern of decreasing amplitude and increasing frequency following therapy. However, in 2 patients with a fatal outcome, no favorable EEG response was observed during treatment, and a simultaneous decline in both delta frequency and delta amplitude was noted as the clinical condition worsened. The results of this study indicate that continuous EEG monitoring in Reye's syndrome may be an important clinical adjunct in evaluating the effectiveness of exchange transfusion therapy and in signaling the need for further treatment.

Adolescent↗
PubMed1977

Acute lymphoblastic leukemia (ALL) antigens detected with antisera to E rosette-froming and non-E rosette-forming ALL blasts.

Based on the presence or absence of erythrocyte receptors(E) a T cell marker, acute lymphocytic leukemia (ALL), can be divided into E+ALL and E-ALL. We studied cell surface antigens on blasts from 12 children with untreated ALL: eight with E-ALL and four with E+ALL. Heterologous antisera were raised against thymus cells, E+ and E-ALL blasts, appropriately absorbed and tested by immunofluorescence and a radiolabeled antibody assay with normal and leukemic lymphoid cells. By both methods, anti-thymus and anti-E+ALL sera reacted with human thymocytes. Specific binding of anti-E+ALL serum to T antigens was indicated by the fact that a single absorption with thymocytes abolished its binding to allogenic thymocytes, and the reactivity of anti-E+ALL serum with thymus, blood and bone marrow lymphocytes was similar to that of anti-thymus serum. After exhaustive absorption with blood leukocytes, anti-E+ALL and E-ALL sera were negative against normal lymphocytes and bone marrow cells from children with ALL in remission. Anti-thymus and anti-E+ALL sera reacted with blasts from patients with E+ALL, but not with E-ALL. In contrast, anti-E+ALL serum reacted with 40 to 96% of blasts from all children with E-ALL, whereas of the four patients with E+ALL, two were negative and two had the lowest percentage of immunofluorescent cells (10 to 22%). These results were confirmed with the radiolabeled antibody assay. Patients with active E-ALL had cells bearing E-ALL antigen(s) in the peripheral blood and bone marrow, but the number of immunofluorescent cells was lower in blood. Cells reactive with anti-E-ALL serum did not react with thymus cells, blood lymphocytes, remission bone marrow cells, Raji cells, PWM and PHA-induced blasts and CLL cells bearing mIg (uk). These data suggest that the antigen detected on E-ALL blasts by anti-E-ALL serum is neither a HLA-related nor a cell differentiation antigen. Thus, by using antiserum to E+ALL blasts, we have confirmed the presence of a T cell-specific antigen(s) on E+ALL cells. This antiserum did not recognize other leukemia-associated antigens common to E+ and E-ALL. We have also demonstrated an antigen(s) which is regularly expressed on E-ALL blasts and is either not detectable or is present in a lower proportion of E+ALL blasts.

Age Factors↗