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Biomedical subjects

R A Larson

Publications and source records attributed to R A Larson.

At least 145 records · Page 8Linked to original sources
PubMed1987

A clinical and pharmacokinetic study of mitoxantrone in acute nonlymphocytic leukemia.

Twenty-two patients with relapsed or refractory acute leukemia received 31 treatment courses of mitoxantrone (10 to 12 mg/m2/d) as a one-hour infusion for five days. Seven of the 13 patients who had greater than or equal to 95% reduction in the leukemia cell mass, calculated using the bone marrow examination on day 6, achieved a complete remission (CR). These remissions lasted up to 14 months without additional therapy. There were no CRs among the 18 patients who had less than 95% cytoreduction by day 6. The sequential addition of 5-azacytidine (200 mg/m2/d) for three days in those patients with residual disease on day 6 provided little additional benefit. Nonhematological toxicity from mitoxantrone was mild, although fever and infection were common. A new high-performance liquid chromatography (HPLC) assay was used to describe the clinical pharmacokinetics of mitoxantrone. Neither clinical response nor toxicity was strongly correlated with the peak plasma mitoxantrone concentration on the first day (mean +/- SD, 510 +/- 206 ng/mL), nor the area under the concentration-time curve (484 +/- 229 ng X h/mL), nor the systemic clearance (405 +/- 124 mL/min/m2). Mitoxantrone causes rapid cytoreduction in acute nonlymphocytic leukemia (ANLL), but the optimal dose and schedule remain to be determined.

Acute Disease↗
PubMed1987

Acute nonlymphocytic leukemia following etoposide and cisplatin combination chemotherapy for advanced non-small-cell carcinoma of the lung.

Combination chemotherapy is frequently used in the therapy of advanced non-small-cell lung cancer (NSCLC), but late complications are rarely recognized because of the short survival of most patients. Of 119 patients with advanced NSCLC treated with cisplatin and other drugs, four patients developed acute nonlymphocytic leukemia (ANLL). All four patients received etoposide and cisplatin with or without vindesine. Leukemia was diagnosed at 13, 19, 28, and 35 months after start of treatment. Three patients had morphologic and/or cytogenetic features of acute leukemia with significant monoblastic involvement; the fourth patient had trilineage dysplasia and cytogenetic abnormalities more commonly associated with therapy-related leukemia. Detailed analysis of the subgroup who survived longer than 1 year (24 patients) suggests that high cumulative doses of etoposide are leukemogenic; the median etoposide dose was 6,795 mg/m2 (first year only) in the four leukemic patients compared with 3,025 mg/m2 in the 20 nonleukemic patients (P less than .01). The rate of ANLL was 0.30 per person-year after the first year (95% confidence limits 0.11 to 0.90), with a cumulative risk of 15% +/- 11% at 2 years, and 44% +/- 24% at 2.5 years. We conclude that high doses of etoposide are potentially leukemogenic, and can induce a syndrome with features of acute monoblastic leukemia de novo that is distinct from other secondary leukemias.

Acute Disease↗
PubMed1987

Acral lividosis--a sign of myeloproliferative diseases. Hyperleukocytosis syndrome in chronic myelogenous leukemia.

Acral ischemia with lividity is a well-described dermatologic sign in the myeloproliferative diseases polycythemia vera and essential thrombocythemia. It has not previously been reported as a sign of chronic myelogenous leukemia (CML). We suggest the term acral lividosis to describe this clinical entity in patients with any myeloproliferative disease. We propose that the pathophysiology of acral lividosis in CML involves occlusion of small blood vessels of the skin by large, nondeformable myeloblasts, a process that has been shown histologically to occur in other organs in patients with CML. This process, called leukostasis, occurs in patients with CML who have over 50.0 X 10(9)/L (50,000/mm3) circulating myeloblasts. Patients manifest cardiorespiratory and central nervous system compromise, a clinical constellation known as the hyperleukocytosis syndrome. Acral lividosis occurred in a patient with CML in whom nearly every organ demonstrated leukostasis on autopsy.

Adult↗
PubMed1987

Association of a chromosomal 3;21 translocation with the blast phase of chronic myelogenous leukemia.

An identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints in bands 3q26 and 21q22, t(3;21)(q26;q22), was found in three male patients with the blast phase of chronic myelogenous leukemia (CML). The abnormality was clonal in all three patients and was always accompanied by either a standard or variant 9;22 translocation resulting in a Philadelphia chromosome (Ph1). In two cases, the t(3;21) was the only abnormality other than a t(9;22) in the primary clone. Serial studies of one patient demonstrated that the t(3;21) occurred as a result of clonal evolution near the time of development of the blast phase. We have not observed the t(3;21) in greater than 500 patients with CML in the chronic phase. Thus, the t(3;21) is a new recurring cytogenetic abnormality associated with the blast phase of CML.

Adult↗
PubMed1986

Studies of the human c-myb gene and its product in human acute leukemias.

The myb gene is the transforming oncogene of the avian myeloblastosis virus (AMV); its normal cellular homolog, c-myb, is conserved across a broad span of evolution. In humans, c-myb is expressed in malignant hematopoietic cell lines and in primary hematopoietic tumors. Partial complementary DNA clones were generated from blast cells of patients with acute myelogenous leukemia. The sequences of the clones were compared to the c-myb of other species, as well as the v-myb of AMV. In addition, the carboxyl terminal region of human c-myb was placed in an expression vector to obtain protein for the generation of antiserum, which was used to identify the human c-myb gene product. Like v-myb, this protein was found within the nucleus of leukemic cells where it was associated with the nuclear matrix. These studies provide further evidence that c-myb might be involved in human leukemia.

Aspartate Carbamoyltransferase↗
PubMed1986

Evidence for the involvement of GM-CSF and FMS in the deletion (5q) in myeloid disorders.

By in situ chromosomal hybridization, the GM-CSF and FMS genes were localized to human chromosome 5 at bands q23 to q31, and at band 5q33, respectively. These genes encode proteins involved in the regulation of hematopoiesis, and are located within a chromosome region frequently deleted in patients with neoplastic myeloid disorders. Both genes were deleted in the 5q-chromosome from bone marrow cells of two patients with refractory anemia and a del(5)(q15q33.3). The GM-CSF gene alone was deleted in a third patient with acute nonlymphocytic leukemia (ANLL) who has a smaller deletion, del(5)(q22q33.1). Leukemia cells from a fourth patient who has ANLL and does not have a del(5q), but who has a rearranged chromosome 5 that is missing bands q31.3 to q33.1 [ins(21;5)(q22;q31.3q33.1)] were used to sublocalize these genes; both genes were present on the rearranged chromosome 5. Thus, the deletion of one or both of these genes may be important in the pathogenesis of myelodysplastic syndromes or of ANLL.

Anemia, Refractory↗
PubMed1986

Clinical and cytogenetic correlations in 63 patients with therapy-related myelodysplastic syndromes and acute nonlymphocytic leukemia: further evidence for characteristic abnormalities of chromosomes no. 5 and 7.

Clinical, histologic, and cytogenetic features in 63 patients with a therapy-related myelodysplastic syndrome (t-MDS) or acute nonlymphocytic leukemia (t-ANLL) following cytotoxic chemotherapy or radiotherapy for a previous disease were analyzed. Eleven patients had received only radiotherapy for the primary disorder. In most cases, high doses had been administered to treatment ports that included the pelvic or spinal bone marrow. Twenty-one patients had received only chemotherapy for their primary disease, all for more than 1 year and all but one with an alkylating agent, either alone or in combination with other drugs. Thirty-one patients had received both radiotherapy and chemotherapy, either concurrently or sequentially. A clonal chromosomal abnormality was observed in marrow or blood cells from 61 of the 63 patients (97%). Fifty-five patients (87%) had a clonal abnormality of chromosomes no. 5 and/or 7 consisting of loss of all or part of the long arm of the chromosome. The critical chromosome region that was consistently deleted in all 17 patients with del(5q) comprised bands q23 to q32. In addition to nos. 5 and 7, five other chromosomes (no. 1, 4, 12, 14, and 18) were found to be nonrandomly involved. Both t-MDS and t-ANLL are late complications of cytotoxic therapies that have distinctive clinical and histologic features and are associated with characteristic aberrations of chromosomes no. 5 and 7. It seems likely that these two chromosomes contain genes involved in the pathogenesis of these hematopoietic neoplasms.

Acute Disease↗
PubMed1986

Hypochlorous acid-activated carbon: an oxidizing agent capable of producing hydroxylated polychlorinated biphenyls.

Granular activated carbon (GAC), in the presence of dilute aqueous hypochlorite solutions typical of those used in water treatment, was converted to a reagent capable of carrying out free-radical coupling reactions and other oxidations of dilute aqueous solutions of phenols. The products included biphenyls with chlorine and hydroxyl substitution (hydroxylated polychlorinated biphenyls). For example, 2,4-dichlorophenol, a common constituent of wastewaters and also natural waters treated with hypochlorite, was converted to 3,5,5'trichloro-2,4'-dihydroxybiphenyl and several related compounds in significant amounts. It is possible that these products pose more of a health hazard than either the starting phenols or the unhydroxylated polychlorinated biphenyl derivatives.

Carbon↗
PubMed1986

Acute myelomonocytic leukemia with abnormal eosinophils and inv(16) or t(16;16) has a favorable prognosis.

Inv(16)(p13q22) and t(16;16)(p13;q22) are recurring chromosomal rearrangements which juxtapose the metallothionein gene cluster at 16q22 with other DNA sequences from 16p13. We have studied 20 men and 13 women who had acute nonlymphocytic leukemia; 27 patients had an inv(16) and six patients had a t(16;16). Eight patients also had trisomy 22, and four had trisomy 8. All but two patients had the unique morphologic features of acute myelomonocytic leukemia with abnormal eosinophils (M4Eo). In one patient with M4 leukemia, abnormal eosinophils were not observed in the marrow. A second patient had acute monocytic leukemia, plus abnormal eosinophils. Eosinophils constituted 1% to 46% (median, 6%) of the bone marrow cells, and in all but a single patient, the eosinophils exhibited distinctly abnormal morphology. Twenty-five patients have had a complete remission (78% of treated patients). Nine patients have remained in remission longer than 24 months. No patient had symptoms of central nervous system (CNS) disease at diagnosis, and none had CNS leukemic mass lesions at any time. Treatment with high-dose cytarabine may have provided prophylactic CNS therapy. Four additional patients with chromosomal rearrangements involving a breakpoint at 16q22 but not at 16p13 have had different morphological features and different clinical courses. Thus, the juxtaposition of genes at 16p13 and 16q22, which occurs both in the inv(16) and the t(16;16), results in a specific subset of acute nonlymphocytic leukemia that has a favorable prognosis.

Chromosome Banding↗
PubMed1986

Prognostic implications of morphology and karyotype in primary myelodysplastic syndromes.

Forty-nine patients with primary myelodysplastic syndromes (MDS) were subclassified according to French-American-British (FAB) Cooperative Group criteria. Eight patients had acquired idiopathic sideroblastic anemia (AISA), ten had chronic myelomonocytic leukemia (CMMoL), 14 had refractory anemia (RA), nine had refractory anemia with excess blasts (RAEB), and five had refractory anemia with excess blasts in transformation (RAEB-T); three patients could not be subclassified. The actuarial median survival for patients with AISA or with RA had not been reached at 60 months of follow-up. The median survival times for patients with CMMoL, RAEB, and RAEB-T were 25, 21, and 16 months, respectively. The percentages of patients with each subtype who developed ANLL were none in AISA, 20% in CMMoL, 7% in RA, 56% in RAEB, and 40% in RAEB-T. Patients with CMMoL had a poor prognosis independent of transformation to acute nonlymphocytic leukemia (ANLL), whereas patients with RAEB and RAEB-T had a high incidence of transformation and short survival times. Clonal chromosomal abnormalities were present in bone marrow cells from 19 patients at the time of diagnosis, and two others developed an abnormal karyotype at the time of leukemic transformation. The most frequent abnormalities, including initial and evolutionary changes, were trisomy 8 (9 patients), deletion of 5q (4 patients), and deletion of 20q (4 patients). The median survival times were 32 months for patients with an abnormal karyotype, and 48 months for those with a normal karyotype (P = 0.2). Specific chromosomal abnormalities were not associated with particular histologic subtypes; however, a high percentage of patients with RAEB and RAEB-T had an abnormal clone (89% and 80%, respectively). The percentages of patients with clonal abnormalities were 13% for AISA, 20% for CMMoL, and 29% for RA. The MDS transformed to ANLL in 42% of patients with an abnormal karyotype, compared to 10% of those with an initially normal karyotype (P less than .01). Among patients with RA, RAEB, and RAEB-T, the risk of leukemic transformation was confined to those with an abnormal karyotype (P less than .01). Thus, in the present study, morphology and karyotype combined were the best indicators of outcome in patients with MDS.

Adolescent↗
PubMed1985

Low-dose cytosine arabinoside (Ara-C) therapy in the myelodysplastic syndromes and acute leukemia.

Twenty-two patients with either a myelodysplastic syndrome or acute nonlymphocytic leukemia were treated with 10-21 days of subcutaneous cytosine arabinoside (Ara-C) (5-10 mg/m2 every 12 hours). There were two complete remissions and ten partial responses. Clinically significant improvements in peripheral blood counts persisted for periods of 8 weeks to greater than 21 weeks. Responses were seen even in patients who had previously proven refractory to conventional induction regimens or high-dose Ara-C. The toxicity, however, was considerable. Nearly all patients developed significant thrombocytopenia. Platelet and red cell transfusion support was required in many cases. The response to low-dose Ara-C therapy seen in patients with the leukemic and myelodysplastic disorders may be mediated by the induction of cell differentiation or a direct cytotoxic effect on a sensitive population of cells. Low-dose Ara-C may provide an alternative therapy in the selected patient with acute nonlymphocytic leukemia or a myelodysplastic syndrome.

Acute Disease↗
PubMed1985

'Golden tongue' syndrome caused by Ramichloridium schulzeri.

A 54-year-old woman entered the hospital for induction chemotherapy for acute lymphocytic leukemia. On hospital day 23, while the patient was neutropenic, an erosive lesion appeared on the left side of the tongue. During the next several days the lesion extended over the dorsum of the tongue and was golden orange. Surface scrapings were obtained; the involved site underwent a biopsy and was cultured. Branching septate mycelia of varying diameters were seen on microscopic examination of direct mounts and a biopsy specimen of the tongue. Eight to ten colonies of a fungus grew out in culture. The fungus was golden orange on Sabouraud's glucose agar and brown-gray on corn-meal agar, and was identified as Ramichloridium schulzeri. The lesion regressed during the next two weeks while the patient received amphotericin B therapy and showed an increased granulocyte count. This case seems to be the first authenticated infection caused by this uncommonly encountered soil saprophyte.

Amphotericin B↗