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Biomedical subjects

C A Koller

Publications and source records attributed to C A Koller.

At least 37 records · Page 2Linked to original sources
PubMed1992

Treatment of newly diagnosed acute myelogenous leukemia with granulocyte-macrophage colony-stimulating factor (GM-CSF) before and during continuous-infusion high-dose ara-C + daunorubicin: comparison to patients treated without GM-CSF.

We gave 56 patients with newly diagnosed acute myelogenous leukemia (AML) granulocyte-macrophage colony-stimulating factor (GM-CSF) 20 or 125 micrograms/m2 once daily subcutaneously before (for up to 8 days or until GM-CSF-related complications developed) and during, or only during (patients presenting with blast counts greater than 50,000 or other leukemia-related complications) ara-C (1.5 g/m2 daily x 4 by continuous infusion) and daunorubicin (45 mg/m2 daily x 3) chemotherapy. Because results seemed independent of GM-CSF schedule, we compared results in these 56 patients with results in 176 patients with newly diagnosed AML given the same dose and schedule of ara-C without GM-CSF (110 patients ara-C alone, 66 patients ara-C + amsacrine or mitoxantrone). Comparison involved fitting a logistic regression model predicting probability of complete remission (CR) and a Cox regression model to predict survival (most patients in all three studies were dead) with treatment included as a covariate in both analyses. After adjusting for other prognostically significant covariates [presence of an antecedent hematologic disorder, an Inv (16), t(8;21), or abnormalities of chromosomes 5 and/or 7, performance status, age, bilirubin], treatment with ara-C + daunorubicin + GM-CSF was predictive of both a lower CR rate and a lower survival probability. There were no treatment-covariate interactions, suggesting that the negative effect of this GM-CSF treatment regime was not an artifact of some imbalance in patient characteristics. The unadjusted Kaplan-Meier hazard rate of the ara-C + daunorubicin + GM-CSF group was not uniquely high during the initial 4 weeks after start of therapy, but was highest among the three treatment groups throughout weeks 5 to 16, suggesting that the negative effect of this treatment was not caused by acute toxicity. Patients who did not enter CR with this treatment tended to have persistent leukemia rather than prolonged marrow aplasia, suggesting that this treatment and, in particular, GM-CSF may increase resistance of myeloid leukemia cells to chemotherapy. To date, relapse rates are similar in all three groups (P = .43) (as are survival rates once patients are in CR) but much of the remission duration data is heavily censored, unlike the survival data. Our results suggest caution in the use of GM-CSF to sensitize myeloid leukemia cells to daunorubicin + ara-C chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Determination of plicamycin in plasma by radioimmunoassay.

This article describes a method for the determination of plicamycin in plasma by radioimmunoassay. The anti-plicamycin antibody was produced against a plicamycin-bovine serum albumin conjugate prepared by using diazotized p-aminobenzoic acid as a cross-linker. The radiolabeled ligand, 125I-plicamycin, was prepared by the chloramine-T method. The linear plicamycin concentration range was 7-400 ng/ml. The coefficients of variation for intra- and interday variabilities were 7.5 and 15%, respectively. No interference was observed from either the structurally related chromomycin A or concomitantly used drugs hydroxyurea or allopurinol. With this method of testing, plicamycin levels in plasma could be determined in patients receiving small (0.85-1.0 mg/m2) therapeutic plicamycin doses. Preliminary pharmacokinetic data in humans indicate that the plasma drug disappearance curve was biphasic with a mean elimination half-life of 10.6 +/- 1.7 h, total clearance rate of 11.1 +/- 0.4 ml/min/m2, and area under the plasma drug concentration-time curve of 1,289-1,546 ng-h/ml. This assay method is clinically useful for pharmacokinetic studies of plicamycin and may be helpful in the design of rational therapeutic drug trials.

Antibody Specificity↗
PubMed1991

Mithramycin inhibits SP1 binding and selectively inhibits transcriptional activity of the dihydrofolate reductase gene in vitro and in vivo.

The promoter of the human dihydrofolate reductase (DHFR) gene contains two consensus binding sites for the DNA binding protein Sp1. DNAse protection and gel mobility shift assays demonstrate binding of recombinant Sp1 to both decanucleotide Sp1 binding sequences which are located 49 and 14 base pairs upstream of the transcription start site. The more distal of the two binding sites exhibits a somewhat higher affinity for Sp1. The G-C specific DNA binding drug, mithramycin, binds to both consensus sequences and prevents subsequent Sp1 binding. Promoter-dependent in vitro transcription of a DHFR template is selectively inhibited by mithramycin when compared to the human H2b histone gene. A similar effect is also noted in vivo. Mithramycin treatment of MCF-7 human breast carcinoma cells containing an amplified DHFR gene induces selective inhibition of DHFR transcription initiation, resulting in a decline in DHFR mRNA level and enzyme activity. This selective inhibition of DHFR expression suggests that it is possible to modulate the overexpression of the DHFR gene in methotrexate resistant cells.

Base Sequence↗
PubMed1990

Fludarabine therapy in macroglobulinemic lymphoma.

Fludarabine, a fluorinated analogue of adenine, was given to 11 patients with macroglobulinemic lymphoma, all but one having failed prior standard chemotherapy. Five patients (45%) responded with more than a 50% reduction of immunoglobulin M (IgM) tumor mass for a projected median duration of longer than 1 year. The onset of remission was usually slow, with a median tumor halving time of 5.2 months in responding patients, emphasizing the importance of repeated courses of treatment. Fludarabine is an important new agent effective against macroglobulinemic lymphoma, and should be evaluated further in combination with other active modalities.

Adult↗
PubMed1990

Stimulation of myelopoiesis in chronic lymphocytic leukemia and in other lymphoproliferative disorders by recombinant human granulocyte-macrophage colony-stimulating factor.

In an attempt to stimulate granulopoiesis, we administered recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) to 11 patients with lymphoproliferative disorders. Ten patients had neutropenia, six of whom had severe neutropenia (less than 500 neutrophils), including two with agranulocytosis. GM-CSF (60-250 micrograms/m2/day) was administered by continuous intravenous infusion daily for 14 days at 2-week intervals. Significant increases in white blood cell counts (1.3-to 11.7-fold) and neutrophils (1.7- to more than 29-fold) were seen in 10 of 11 patients, including one patient with agranulocytosis. Eosinophils (3.9- to greater than 65-fold) and monocytes (1.3- to 5-fold) increased as well. In contrast, no significant increases were seen in total lymphocytes or in different phenotypic subsets of lymphocytes during treatment. The overall proportion of myeloid and lymphoid elements in bone marrow remained stable. These results indicate that GM-CSF is effective in stimulating myelopoiesis in neutropenic states associated with lymphoproliferative disorders. Further studies will be necessary to determine whether the correction of neutropenia ultimately translates into clinical benefit.

Bone Marrow↗
PubMed1989

Phase II study of low-dose continuous infusion homoharringtonine in refractory acute myelogenous leukemia.

Thirty-one patients with a diagnosis of refractory acute myelogenous leukemia received homoharringtonine as their first (15 patients) or second (16 patients) salvage therapy. Homoharringtonine was given as a continuous infusion of 2.5 mg/m2 daily for 15 to 21 days to 13 patients (schedule 1), and of 3.0 mg/m2 daily for 15 days in 18 patients (schedule 2). Overall, one patient achieved complete remission (3%), and three (10%) had a hematologic improvement with normalization of the marrow and peripheral blood picture except for persistent thrombocytopenia. Six patients (19%) demonstrated prolonged myelosuppression, three (23%) on schedule 1 and three (17%) on schedule 2. Cardiovascular complications were minimal consisting of hypotension in one patient (3%) and supraventricular arrhythmias in two patients (6%). Hyperglycemia was observed in 42% of patients and was significant in 10%. The authors conclude that homoharringtonine, at the dose schedule investigated, has definite but low antileukemic efficacy. The low-dose continuous infusion schedule was associated with prolonged myelosuppression but no serious cardiovascular complications. The role of such therapy in myeloproliferative disorders, especially chronic myelogenous leukemia, deserves consideration.

Adult↗
PubMed1989

Chemotherapy-induced acral erythema: desquamating lesions involving the hands and feet.

Patients receiving very high doses of chemotherapeutic drugs, particularly cytarabine (cytosine arabinoside, ara-C, Cytosar), may develop chemotherapy-induced acral erythema, a painful toxic rash of the palmar surfaces of the hands that progresses to edema, blister formation, and desquamation. In more severe cases, the feet are involved, and they show similar changes. Plastic surgeons may be consulted because of the hand involvement and the clinical resemblance, after desquamation, to a very superficial second-degree burn. In patients who have had bone marrow transplantation, this diagnosis must be distinguished from graft-versus-host reaction--a desquamating skin lesion that can affect a similar anatomical area but that is progressive and productive of serious consequences. Acral erythema appears to be self-limited and requires only supportive treatment.

Adolescent↗
PubMed1989

Mithramycin blocks protein binding and function of the SV40 early promoter.

Specific interactions between DNA and transcription factors are necessary for transcription initiation. These interactions provide a potential target for the selective inhibition of eukaryotic gene expression. Mithramycin is a DNA binding antibiotic which, in the presence of Mg2+, binds G-C containing sequences in the minor groove. The SV40 early promoter contains six G-C decanucleotide sequences, which are binding sites for the transcriptional activating factor, Sp1. Each of the six Sp1 binding sites of this promoter is protected from DNAse 1 digestion by mithramycin binding. Mithramycin binding to the G-C rich sequences in the SV40 early promoter prevents subsequent protein binding to these sequences. The gel retardation of the SV40 early promoter fragment incubated with a HeLa cell extract is completely abrogated by pretreatment of the DNA fragment with mithramycin. The functional significance of mithramycin binding is reflected in the ability of mithramycin to block promoter function. Mithramycin inhibits promoter dependent transcription in an in vitro runoff transcription system in a concentration dependent manner. This suggests that mithramycin prevents transcriptional activation of the SV40 early promoter by blocking binding of transcriptional activating proteins to G-C rich promoter regions.

Base Sequence↗
PubMed1989

Relapse of adult acute myelogenous leukemia isolated in testicle.

Isolated testicular relapse of acute leukemia, although common in children, is rare in adults. A 63-year-old man who had completed induction and intensification chemotherapy presented with unilateral testicular enlargement as the sole manifestation of biopsy-proven acute leukemia relapse. The infiltrative characteristics of acute monocytic leukemia and the anatomic barriers and location of the testicles may have provided a sanctuary from chemotherapy.

Humans↗
PubMed1987

Mithramycin selectively inhibits transcription of G-C containing DNA.

Mithramycin induces a reversible inhibition of cellular RNA synthesis without affecting DNA synthesis. The authors have shown this drug induces myeloid differentiation of HL-60 promyelocytic leukemia cells and is an effective agent in certain patients with chronic granulocytic leukemia. In order to investigate the mechanism by which this drug inhibits RNA synthesis we have compared the effect of mithramycin on RNA synthesis by whole cells, isolated nuclei, and RNA synthesis by isolated E. coli RNA polymerase and eukaryotic RNA polymerase II. Exposure of HL-60 cells to mithramycin at concentrations of 4.6 X 10(-7) m or higher for 48 hours causes an almost immediate inhibition of RNA synthesis (up to 85% at 4 hours) with only modest cytotoxicity at these concentrations. Endogenous RNA synthesis by isolated nuclei can be inhibited by mithramycin only at high concentrations (greater than 10(-5) m), suggesting that mithramycin primarily may inhibit initiation, rather than elongation. Mithramycin inhibits in vitro transcription of salmon sperm DNA by E. coli RNA polymerase at DNA:drug ratios similar to those required for RNA synthesis inhibition in whole cells. Similar DNA binding studies with synthetic oligonucleotides demonstrate that mithramycin is a potent inhibitor of transcription of Poly dG.dC by E. coli RNA polymerase but has no effect on transcription of Poly dA.dT. The rapid inhibition of whole cell and isolated RNA polymerase transcription, and the relative insensitivity of isolated nuclei, suggest mithramycin may interact with specific DNA sequences in order to inhibit the initiation of RNA synthesis in intact cells.

Base Composition↗
PubMed1987

Bordetella bronchiseptica pneumonia in a patient with chronic lymphocytic leukemia.

This case report describes two episodes of pneumonia caused by Bordetella bronchiseptica in a patient with chronic lymphocytic leukemia. There was discrepancy between the in vitro sensitivity testing of the organism and subsequent clinical response to several antimicrobial agents. Human infection with B bronchiseptica is almost always associated with severe underlying disease and contact with an appropriate animal reservoir.

Aged↗
PubMed1987

Molecular analysis of chromosome 22 breakpoints in adult Philadelphia-positive acute lymphoblastic leukaemia.

The Philadelphia (Ph) translocation, t(9:22)(q 34:q11), is found in the majority of patients with chronic myelogenous leukaemia (CML) as well as in approximately 20% of adult acute lymphoblastic leukaemia (ALL) patients. The chromosome 22 breakpoint in CML has been localized within a restricted 5.8 kb segment of DNA known as the breakpoint cluster region (bcr). To investigate the chromosome 22 breakpoint in ALL, we analysed five adult Ph-positive ALL patients for bcr rearrangement. Rearrangement was detected within bcr in two patients. However, in one patient the break occurred 5' to the first exon of bcr and in two patients the bcr region was not involved. We conclude that the identical cytogenetic marker, t(9:22), may yield a different genomic configuration in ALL and CML.

Acute Disease↗
PubMed1986

Preliminary observations on the therapy of the myeloid blast phase of chronic granulocytic leukemia with plicamycin and hydroxyurea.

We observed a dramatic improvement in the peripheral blood counts of a patient in the myeloid blast phase of chronic granulocytic leukemia after plicamycin (mithramycin) therapy of concurrent hypercalcemia. We then treated eight additional patients in the blast phase of chronic granulocytic leukemia with a combination of alternate-day plicamycin and daily hydroxyurea. All six patients with myeloid morphology at the time of blast crisis responded with a return to a chronic phase without an intervening pancytopenic period. Of three patients with lymphoid morphology at the time of treatment, only one responded (this patient had recently relapsed and converted from myeloid to lymphoid morphology). Another patient with nonmyeloid, nonlymphoid blast morphology also did not respond. Continual therapy with the two-drug combination appeared to be necessary, since early relapses were seen in responding patients whose therapy was interrupted. These data are preliminary and will need further confirmation, but they suggest that the combination of alternate-day plicamycin and daily hydroxyurea may be effective in the myeloid blast phase of chronic granulocytic leukemia.

Adult↗
PubMed1986

Response to 2'-deoxycoformycin after failure of interferon-alpha in nonsplenectomized patients with hairy cell leukemia.

Two patients with hairy cell leukemia with massive splenomegaly and severe pancytopenia were treated with recombinant alpha-A interferon (IFN-alpha-2a). There was no significant response to a trial of IFN-alpha-2a (11 and 20 weeks) with respect to blood counts or spleen size. Subsequent treatment with 2'-deoxycoformycin (dCF) for 8 consecutive weeks (4 mg/m2/wk) resulted in normalization of spleen size and a normalization of peripheral blood counts and bone marrow in one patient. The second patient demonstrated a reduction in spleen size and improved blood counts following 9 weeks of dCF therapy but eventually became refractory. This demonstrates that dCF is non-cross-resistant with interferon and confirms the efficacy of dCF in nonsplenectomized patients.

Adult↗
PubMed1985

In vivo differentiation of blast-phase chronic granulocytic leukemia. Expression of c-myc and c-abl protooncogenes.

A patient with chronic granulocytic leukemia in acute blastic transformation was treated with mithramycin, an RNA synthesis inhibitor, after in vitro exposure of her leukemic cells to mithramycin showed differentiation to normal appearing granulocytes. Mithramycin therapy in vivo resulted in a prompt and dramatic hematologic response. Before therapy, the patient's leukemic cells had high levels of transcription of the cellular myc and abl protooncogenes. After initiation of therapy, protooncogene mRNA decreased rapidly. These observations indicate that mithramycin can induce differentiation both in vitro and in vivo and suggest that such changes may be associated with altered oncogene expression.

Adolescent↗
PubMed1983

Adenosine deaminase deficiency with normal immune function. An acidic enzyme mutation.

In most instances, marked deficiency of the purine catabolic enzyme adenosine deaminase results in lymphopenia and severe combined immunodeficiency disease. Over a 2-yr period, we studied a white male child with markedly deficient erythrocyte and lymphocyte adenosine deaminase activity and normal immune function. We have documented that (a) adenosine deaminase activity and immunoreactive protein are undetectable in erythrocytes, 0.9% of normal in lymphocytes, 4% in cultured lymphoblasts, and 14% in skin fibroblasts; (b) plasma adenosine and deoxyadenosine levels are undetectable and deoxy ATP levels are only slightly elevated in lymphocytes and in erythrocytes; (c) no defect in deoxyadenosine metabolism is present in the proband's cultured lymphoblasts; (d) lymphoblast adenosine deaminase has normal enzyme kinetics, absolute specific activity, S20,w, pH optimum, and heat stability; and (e) the proband's adenosine deaminase exhibits a normal apparent subunit molecular weight but an abnormal isoelectric pH. In contrast to the three other adenosine deaminase-deficient healthy subjects who have been described, the proband is unique in demonstrating an acidic, heat-stable protein mutation of the enzyme that is associated with less than 1% lymphocyte adenosine deaminase activity. Residual adenosine deaminase activity in tissues other than lymphocytes may suffice to metabolize the otherwise lymphotoxic enzyme substrate(s) and account for the preservation of normal immune function.

Adenosine Deaminase↗