Biological response modifiers.
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Acetylmuramyl-Alanyl-Isoglutamine↗
Biomedical subjects
J W Clark
Publications and source records attributed to J W Clark.
Interleukin 2 and lymphokine-activated killer cell therapy: analysis of a bolus interleukin 2 and a continuous infusion interleukin 2 regimen.
Several groups have described the efficacy of interleukin 2 (IL-2) plus lymphokine-activated killer (LAK) cells in the treatment of cancer patients with significant response rates noted in patients with renal cell cancer and malignant melanoma; however, the optimum regimen remains undefined. The Biological Response Modifiers Program of the National Cancer Institute conducted two consecutive Phase I/II studies evaluating the toxicity and clinical efficacy of different methods of IL-2 and LAK cell therapy. In the first trial, we modified the standard Rosenberg regimen by decreasing the duration of priming in an attempt to reduce the toxicity related to this phase of the therapy and thereby administer more IL-2 doses with the LAK cells. In the second trial, we used a continuous i.v. infusion IL-2 regimen and altered both the leukapheresis procedure and the LAK cell culture techniques based on our in vitro and preclinical studies suggesting that 2-day LAK cells were superior. Thirty cancer patients received i.v. bolus IL-2 at 100,000 units/kg every 8 h for 3 days during priming and for 5 days during LAK cell administration. A second group of 22 cancer patients received IL-2 by continuous i.v. infusion at 3 x 10(6) units/m2 for 5 days during priming and an additional 5 days of IL-2 with the LAK cell phase of the treatment. The timing of the start of the leukapheresis procedures, their duration and number, and the LAK cell culture techniques differed in the two trials. Overall, 52 patients with various cancers were treated. The toxicities associated with each regimen were similar to those seen in other IL-2 plus LAK cell trials. Four patients (one each with melanoma and diffuse large cell lymphoma and two with renal cell cancer) exhibited partial responses lasting 2, 4, 10, and 15+ mo. Serial tumor biopsies from treated patients demonstrated that therapy can produce a marked mononuclear cell infiltrate and an increase in HLA-DR expression on tumor cells. There was no difference in the overall response rate between the two regimens, but toxicity was less with continuous i.v. infusion IL-2. The 5-day continuous i.v. infusion regimen resulted in significantly higher rebound lymphocytosis, cell yield from leukapheresis, and number of LAK cells harvested from culture.
Adolescent↗
Exacerbation of symptoms of autoimmune disease in patients receiving alpha-interferon therapy.
The occurrence of autoimmune disease in patients receiving alpha-interferon (alpha-IFN) therapy has been reported in several studies; these include autoimmune thyroiditis, thrombocytopenia, anemia, exacerbation of psoriasis, and the occurrence of sarcoidosis. The primary mechanism presumably is the emergence of autoantibodies to various structural proteins or receptors. Two studies have recently shown that a significant percentage of patients treated with recombinant alpha-interferon (r alpha-IFN) do form autoantibodies. The authors report six additional cases of development or exacerbation of autoimmune phenomena in patients receiving alpha-IFN therapy. Five of these patients developed symmetric polyarthropathies and the sixth had thyroiditis. The presence of a history of underlying autoimmune disease or baseline serologic abnormalities in five of these patients, including the patient who developed thyroiditis, suggests that alpha-IFN treatment can lead to the exacerbation of an underlying subclinical autoimmune process.
Adult↗
Recombinant human granulocyte-macrophage colony-stimulating factor in patients with advanced malignancy: a phase Ib trial.
We evaluated the toxic, hematopoietic, and immunomodulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF). The rHuGM-CSF was administered at doses up to 50 micrograms/kg by daily 2-hour intravenous infusions to 11 patients with advanced malignancy. It induced dose-related increases in cells of the myeloid series, but it had no significant effect on reticulocyte or platelet counts. Bone marrow cellularity increased with higher doses of rHuGM-CSF, but there was a dose-related decrease in the number of colony-forming units--granulocyte-monocyte--and colony-forming units--granulocyte-erythrocyte-monocyte-megakaryocyte--per 10(5) bone marrow cells. The rHuGM-CSF caused transient increased expression of CD11b and CD16 on granulocytes but increased expression of HLA-DR and decreased expression of the high-affinity Fc receptor on monocytes and no change in monocyte production of H2O2. Thus, rHuGM-CSF has potent effects on granulocyte, eosinophil, and monocyte numbers in the peripheral blood and bone marrow. In addition, it enhances the expression of monocyte and granulocyte activation-associated surface markers.
Antigens, Differentiation↗
Low- versus high-dose interferon alfa-2a in relapsed indolent non-Hodgkin's lymphoma.
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Adult↗
Immunomodulatory properties and toxicity of interleukin 2 in patients with cancer.
We performed a phase Ia/Ib study of interleukin 2 (IL2) in patients with cancer. Single doses of IL2 from 10(3) units/m2 to 10(7) units/m2 were well tolerated but failed to induce significant immunological changes. Chronic IL2 treatment for 5 days out of 7 for 3 weeks was well tolerated at doses below 10(7) units/m2 and was accompanied by significant immunological changes. Following chronic treatment with intramuscular injections of IL2 at 1 x 10(6) units/m2, we observed augmentation of peripheral blood natural killer activity and induction of peripheral blood LAK activity. Induction of LAK activity was most evident when IL2 was included in the cytotoxicity assay. There was a marked increase in the number of peripheral blood mononuclear cells bearing the Leu-19 marker in association with the observed increases in natural killer and LAK activity. A small percentage of Leu-19+ cells coexpressed CD3. There was heterogeneous expression of the low affinity Fc receptor (CD16). In vivo induced Leu-19+ cells could be divided into two populations, dim and bright, based on the intensity of fluorescent staining with antibodies to Leu-19. The majority of Leu-19 bright cells were CD16- while the majority of Leu-19 dim cells were CD16+. In addition, the intensity of CD16 staining was higher for Leu-19 dim cells than for Leu-19 bright cells. Increases in the amounts of CD38 and CD8 antigens were also observed. Significant increases in serum levels of the soluble IL2 receptor were observed during treatment. One partial remission was noted in a woman with non-Hodgkin's lymphoma.
Cell Line↗
Experiments in artificial psychology: conditioning of asynchronous neural network models.
An asynchronous model for the dynamics of neural networks admits learning behaviors characteristic of classical and operant conditioning provided that appropriate plasticity algorithms are chosen. Stimulus generalization and discrimination can also be observed. Studies of such psychological phenomena are carried out by computer simulation of networks with designated sensory, association, and motor neurons, and the results are compared to those for live subjects. Various prescriptions for plasticity are investigated, including those corresponding to reward, punishment, and unlearning routines. These are characterized by their effect on network stability as quantified by a newly proposed stability measure.
Animals↗
T-cell subsets in healthy teenagers: transition to the adult phenotype.
Little is known about the normal range and variability of T-cell subsets in older children. We analyzed peripheral blood mononuclear cell subsets in 112 healthy children, ages 12-19 years (mean +/- SD: 15.4 +/- 1.9 years), using monoclonal antibodies and flow cytometry. The study population included 28 blacks and 84 whites, with 59 boys and 53 girls. The mean +/- SD cell subset values were: CD3+ T cells, 74.0 +/- 7.8%; CD4+ helper-inducer T cells, 46.8 +/- 6.9%; CD8+ suppressor-cytotoxic T cells, 27.3 +/- 5.7%; CD4:CD8 helper:suppressor ratio, 1.81 +/- 0.57; CD16+ natural killer cells, 4.4 +/- 3.1%; CD19+ B cells, 10.0 +/- 5.3%; CD14+ monocytes, 20.0 +/- 6.5%; and HLA-DR cells, 15.4 +/- 4.8%. Overall, boys had a higher proportion of HLA-DR+ cells than girls, attributable to an increase in CD19+ B cells. Blacks tended to have a higher proportion of HLA-DR+ cells than whites, apparently due to an increase in activated T cells. Detailed analysis by age group revealed a striking transition in the pattern of CD4+ and CD8+ cell populations. The CD4:CD8 ratio, higher in boys than girls for ages 12-16, was reversed to the "adult" pattern in 17-19 year olds, with a higher CD4:CD8 ratio in girls. These data provide important baseline values for healthy children and stress the importance of establishing normative ranges for pediatric subjects separately from adults.
Adolescent↗
A model of the muscarinic receptor-induced changes in K(+)-current and action potentials in the bullfrog atrial cell.
A model is formulated for characterizing the behavior of the acetylcholine (ACh)-sensitive K+ membrane channel (muscarinic channel) in bullfrog atrial myocytes. Parameters of the muscarinic current model are chosen in fit available data from the literature on bullfrog atrial myocytes (3, 4, 45). This model is subsequently incorporated into a large mathematical model of the bullfrog myocyte that is based on quantitative whole-cell voltage clamp data (40). Simulations are conducted on the active atrial cell model in bathing media containing ACh at different concentrations to explore the effect of this muscarinic channel on the electrical behavior of the myocyte. The model predicts a progressive shortening of the action potential with increasing [ACh], as well as an indirect influence of the muscarinic K+ current on the other membrane currents of the atrial cell. Interpretation of the simulation results provides suggestions for the probable mechanisms underlying the shortening of the action potential due to activity of the muscarinic channel. Specifically, the model predicts that with an increase in ACh concentration: (a) the outward muscarinic current, IK,ACh(t), increases in magnitude but shortens in duration; (b) the calcium current, ICa(t), may increase in magnitude, but when it does so it decreases in duration compared with the control conditions; (c) the intracellular Ca2+ concentration [Ca2+]i waveform during the action potential decreases in both magnitude and duration. Because the contractile activity of the cell is controlled by the [Ca2+]i waveform, the model predicts a decrease in contractile strength with an increase in ACh concentration in the bathing medium; i.e., a negative inotropic effect.
Action Potentials↗
Routes to chaos in a model of a bursting neuron.
Chaotic regimens have been observed experimentally in neurons as well as in deterministic neuronal models. The R15 bursting cell in the abdominal ganglion of Aplysia has been the subject of extensive mathematical modeling. Previously, the model of Plant and Kim has been shown to exhibit both bursting and beating modes of electrical activity. In this report, we demonstrate (a) that a chaotic regime exists between the bursting and beating modes of the model, and (b) that the model approaches chaos from both modes by a period doubling cascade. The bifurcation parameter employed is the external stimulus current. In addition to the period doubling observed in the model-generated trajectories, a period three "window" was observed, power spectra that demonstrate the approaches to chaos were generated, and the Lyaponov exponents and the fractal dimension of the chaotic attractors were calculated. Chaotic regimes have been observed in several similar models, which suggests that they are a general characteristic of cells that exhibit both bursting and beating modes.
Animals↗
A phase I-II trial of continuous-infusion cisplatin, continuous-infusion 5-fluorouracil, and VP-16 in colorectal carcinoma.
Twenty-nine evaluable patients with colorectal adenocarcinoma were treated in a phase I-II trial of combination chemotherapy with a 72-h continuous infusion of cisplatin (CDDP) and 5-fluorouracil (5-FU) with an infusion of VP-16 given at 24 and 48 h after the start of therapy. There were five (17 +/- 14%) partial responses lasting 2-6 months (median, 3). Three of these responses occurred among the 10 previously untreated patients. The toxicity of this regimen was pronounced. Four of eight patients with severe neutropenia required hospitalization for infections, two of which were life-threatening; one of six patients with severe thrombocytopenia had a life-threatening hemorrhagic complication; and four patients experienced severe, dose-limiting fatigue. These complications occurred principally with CDDP and VP-16 at doses above 27.5 mg/m2/day and 110 mg/m2/dose, respectively. Mucositis occurred in six patients and limited the dose of 5-FU to 1,300 mg/m2/day. Although the response rate appeared to be high in previously untreated patients, the minimal palliative benefit of treatment and the brief duration of the responses do not compensate for the toxicity observed.
Adenocarcinoma↗
A mathematical model of a bullfrog cardiac pacemaker cell.
Previous models of cardiac cellular electrophysiology have been based largely on voltage-clamp measurements obtained from multicellular preparations and often combined data from different regions of the heart and a variety of species. We have developed a model of cardiac pacemaking based on a comprehensive set of voltage-clamp measurements obtained from single cells isolated from one specific tissue type, the bullfrog sinus venosus (SV). Consequently, sarcolemmal current densities and kinetics are not influenced by secondary phenomena associated with multicellular preparations, allowing us to realistically simulate processes thought to be important in pacemaking, including the Na(+)-K+ pump and Na(+)-Ca2+ exchanger. The membrane is surrounded extracellularly by a diffusion-limited space and intracellularly by a limited myoplasmic volume containing Ca2(+)-binding proteins (calmodulin, troponin). The model makes several predictions regarding mechanisms involved in pacing. 1) Primary pacemaking cannot be attributed to any single current but arises from both the lack of a background K+ current and a complex interaction between Ca2+, delayed-rectifier K+, and background leak currents. 2) Ca2+ current displays complex behavior and is important during repolarization. 3) Because of Ca2+ buffering by myoplasmic proteins, the Na(+)-Ca2+ exchanger current is small and has little influence on action potential repolarization but may modulate the maximum diastolic potential. 4) The Na(+)-K+ pump current does not play an active role in repolarization but is of sufficient size to modulate the rate of diastolic depolarization. 5) K+ accumulation and Ca2+ depletion may occur in the extracellular spaces but play no role in either the diastolic depolarization or repolarization of a single action potential. This model illustrates the importance of basing simulations on quantitative measurements of ionic currents in myocytes and of including both electrogenic transporter mechanisms and Ca2+ buffering by myoplasmic Ca2(+)-binding proteins.
Animals↗
A mathematical model of electrophysiological activity in a bullfrog atrial cell.
We have developed a model of cardiac atrial electrical activity based on voltage-clamp measurements obtained from single cells isolated from the bullfrog atrium. These measurements have allowed us to simulate a number of processes thought to be important in action potential initiation, repolarization, and the excitation-contraction (EC) coupling process. In this atrial model, the cell membrane contains both channel-mediated (Na+, Ca2+, inward rectifier K+, delayed rectifier K+, linear background leak) and transporter-mediated (Na(+)-K+ pump, Na(+)-Ca2+ exchanger, Ca2+ pump) currents. The cell is surrounded extracellularly by a diffusion-limited space. The intracellular volume contains Ca2(+)-binding proteins (calmodulin, troponin). The model makes several important predictions. 1) Incomplete inactivation of the Ca2+ current provides an inward current the maintains the plateau of the action potential. 2) Activation of the delayed rectifier K+ current initiates repolarization. 3) Due to Ca2+ buffering by myoplasmic proteins the Na(+)-Ca2+ exchanger current is relatively small and has little influence on repolarization. 4) The Na(+)-K+ pump current does not play a major role in repolarization. 5) K+ accumulation and Ca2+ depletion may occur in the extracellular spaces. 6) Modulation of EC coupling is governed by interactions between the myoplasmic Ca2(+)-binding proteins; specifically, the inotropic "positive staircase effect" may be explained by interactions between Ca2+ and Mg2+ at a competitive binding site on troponin. When considered in conjunction with the results of our model of primary pacemaking in the sinus venosus [Rasmusson et al., Am. J. Physiol. 259 (Heart Circ. Physiol. 28): H352-H369, 1990], this atrial model shows how the presence or absence of certain transmembrane currents can change action potential characteristics and consequently alter the relative influence of the various transporter-mediated and channel-mediated currents.
Action Potentials↗
Intraperitoneal lymphokine-activated killer-cell and interleukin-2 therapy for malignancies limited to the peritoneal cavity.
Autologous lymphokine-activated killer (LAK) cells and recombinant human interleukin-2 (rIL-2) were administered intraperitoneally (IP) to 24 patients with malignancies limited to the peritoneal space. Ten patients had ovarian cancer, 12 had colorectal cancer, and one patient each had endometrial carcinoma and primary small-bowel adenocarcinoma. All ovarian cancer patients, three of twelve colorectal cancer patients, and one patient with endometrial carcinoma had received prior therapy. Patients received IL-2 100,000 U/kg every 8 hours intravenously (IV) for 3 days, and 2 days later underwent daily leukapheresis for 5 days. LAK cells were generated in vitro by incubating the peripheral blood mononuclear cells in IL-2 for 7 days and were then administered IP daily for 5 days through a Tenckhoff catheter (Davol, Inc, Cranston, RI) together with IL-2 25,000 U/kg IP every 8 hours. All but one patient completed at least one cycle of therapy. Toxic side effects included minor to moderate hypotension, fever, chills, rash, nausea, vomiting, abdominal pain and distension, diarrhea, oliguria, fluid retention, thrombocytopenia, and minor elevations of liver function tests; all of these rapidly improved after discontinuation of IL-2. One patient had a grand mal seizure, and one suffered a colonic perforation; these were felt to be treatment-related. IP fibrosis developed in 14 patients and limited repeated cyclic administration of this therapy in five patients. Two of 10 (20%) ovarian cancer patients and five of 12 (42%) colorectal cancer patients had laparoscopy- or laparotomy-documented partial responses. We conclude that LAK cells and rIL-2 can be administered IP to cancer patients, resulting in moderate to severe short-term toxicity and modest therapeutic efficacy. Further investigation of this form of adoptive immunotherapy modified to address the problem of IP fibrosis and with lower IP IL-2 doses is justified by these initial results.
Adult↗
Toxicity, immunogenicity, and tumor radioimmunodetecting ability of two human monoclonal antibodies in patients with metastatic colorectal carcinoma.
Two human immunoglobulin M (IgM) monoclonal antibodies (MoAbs), 16.88 and 28A32, which react with cytoplasmic (28A32 and 16.88) or cell surface (28A32) determinants on human colon carcinoma cells, were administered intravenously to 26 patients with metastatic colorectal carcinoma to determine if they could localize to sites of metastatic disease, if they had any antitumor or toxic effects, and to determine whether they would elicit an antihuman MoAb response. Serial scans showed tumor uptake of radioisotope in 12 of 16 patients receiving 131I-labeled 28A32 and in nine of 12 patients receiving 131I-labeled 16.88. No antitumor effects were seen with either antibody. No antibody-related toxic effects were observed following administration of 16.88, but two patients developed localized urticarial reactions following injection with antibody 28A32. No patient developed an antibody response to 16.88. Anti-28A32 reactivity was found in five of 12 (42%) normal sera and in seven of 23 (30%) patients before receiving any antibody. Following administration of 28A32, a low titer (1:10 dilution) of anti-28A32 developed in four patients with no preexisting antibody, a decrease in the preexisting titer was seen in three other patients, the titer remained constant in one patient, and no anti-28A32 was ever detected in six patients. In most cases, anti-28A32 activity was lost at dilutions greater than 1:10 and did not appear to affect antibody half-life in the serum or whole body retention of the antibody. We conclude that these human IgM MoAbs are capable of localizing at sites of disease in vivo, are nontoxic, and are poorly immunogenic in humans. Further studies to determine the specificity of targeting and to improve the delivery of antibody to sites of tumor are indicated.
Antibodies, Monoclonal↗
Treatment of hairy cell leukemia with alternating cycles of pentostatin and recombinant leukocyte A interferon: results of a phase II study.
Fifteen patients with hairy cell leukemia (HCL) were treated with deoxycoformycin (pentostatin; dCF) (4 mg/m2 intravenous [IV] every week x 3) and recombinant interferon-alpha 2a (rIFN-alpha 2a) (3 x 10(6) units subcutaneously [SC] daily x 4 weeks) in alternating months for a total of 14 months. Eleven patients had undergone splenectomy; four had received prior systemic therapy with chlorambucil and/or steroids. All 15 are evaluable for toxicity and peripheral blood response, while 14 are assessable for bone marrow response. Toxicity was tolerable with grade 3 or 4 nausea and vomiting in three patients, neutropenic fevers in five, transient but significant depression in eight, and localized cutaneous herpes zoster in four. Circulating hairy cells were undetectable by the end of the first month in 10 of 13 patients, and by the end of the second month in the other three. Fourteen patients had bilateral bone marrow biopsies performed at baseline after 6 months of treatment, at the end of treatment (14 months), and at 6-month intervals during follow-up. Before treatment, all patients had hypercellular marrows with hairy cels replacing normal marrow elements; all showed at least a 95% clearing of their hairy cell infiltrate by 6 months of therapy. However, small collections of residual hairy cells could be detected intermittently on at least one side of bilateral samples in all patients. All patients have completed treatment with a median duration of follow-up off therapy of 27 months (range, 15 to 31 months). To date, all peripheral counts and serum soluble interleukin-2 receptor (sIL2R) levels remain stable, and no patient has had progression of the hairy cell infiltrate in the bone marrow. Although no patient achieved a pathologic complete response, alternating monthly cycles of dCF and rIFN-alpha 2a produced durable partial remissions (PRs) in all patients. Continued follow-up is required to determine the length of such remissions.
Adult↗
Biological response modifiers.
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Adjuvants, Immunologic↗
Intraperitoneal lymphokine-activated killer cell/interleukin-2 therapy in patients with intra-abdominal cancer: immunologic considerations.
Lymphokine-activated killer (LAK) cells and interleukin-2 (IL-2) were administered by the ip route to patients with intra-abdominal malignancies. Pharmacokinetic studies of IL-2 revealed 10- to 100-fold higher concentrations of IL-2 in peritoneal fluid versus serum. Ip levels of IL-2 were maintained well above those required to generate and maintain LAK cells in vitro. LAK cell activity was detectable in the peritoneal fluid for the duration of each treatment cycle and did not disappear until IL-2 was discontinued. Detection of interferon-gamma (IFN-gamma) in the peritoneal fluid of all patients was consistent with production in situ by activated lymphocytes. In some patients, low but detectable levels of IFN-gamma were also found in the serum. In vivo activation of monocytes in the peritoneal fluid as measured by in vitro production of hydrogen peroxide was documented in the majority of patients. Neither interleukin-1 nor tumor necrosis factor-alpha was detected in the peritoneal fluid. We found no correlation between the presence or levels of IL-2, IFN-gamma, or LAK cell lytic activity in peritoneal fluid or serum and response or nonresponse to therapy.
Abdominal Neoplasms↗