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Biomedical subjects

A F List

Publications and source records attributed to A F List.

At least 55 records · Page 3Linked to original sources

Predominance of chromosome 5 deletions in myeloid neoplasia associated with solid tumors managed by surgical excision.

To assess potential differences in genetic predisposition to myeloid neoplasia, we evaluated the karyotypes and reviewed results of cytogenetic studies on bone marrow specimens from six patients with myelodysplastic syndrome, or acute myeloid leukemia, and a history of solid tumor managed solely by surgical resection. Structural or numerical deletions of chromosome 5 were identified in each of four patients with abnormal marrow karyotypes. Constitutional karyotypes were normal in two patients studied with clonal marrow chromosome abnormalities. Review of previously reported cases of myeloid neoplasia following resection of solid tumors disclosed a preponderance of chromosome 5 deletions. Predisposition to specific chromosome loss may influence genetic expression of disease in solid tumor patients developing hematologic malignancy.

Acute Disease↗

Multidrug resistance in acute leukemia: a conserved physiologic function.

Native resistance to conventional chemotherapy remains an important cause of treatment failure in the adult acute leukemias. Delineation of cellular mechanisms of drug resistance therefore represents a prerequisite to the development of more effective treatment strategies. The multidrug resistance (MDR) phenotype represents one such mechanism of resistance with direct clinical relevance. This phenotype occurs normally in certain mammalian tissues, and is detectable in tumor cell lines selected for resistance to naturally occurring antineoplastics. The mdr1 gene or its glycoprotein product, P-glycoprotein, is detected with high frequency in secondary acute myeloid leukemia (AML) and poor-risk subsets of acute lymphoblastic leukemia. In prospective studies in AML, MDR overexpression is an independent determinant of response to treatment and overall survival with conventional-dose induction regimens. Investigations of mdr1 regulation in normal hematopoietic elements has shown a pattern which corresponds to its regulation in acute leukemia, explaining the linkage of mdr1 to specific cellular phenotypes. Therapeutic trials are now in progress to test the ability of various MDR-reversal agents to restore chemotherapy sensitivity in high-risk acute leukemias.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Recurrent hemorrhagic choroidal detachment associated with disseminated intravascular coagulation.

We report the case of a patient with recurrent hemorrhagic choroidal detachments after combined cataract and filtering surgery associated with exacerbation of chronic disseminated intravascular coagulation (DIC). It was postulated that the formation and drainage of the hemorrhagic choroidal detachments induced thrombin generation and consequently coagulation factor and platelet consumption. Fibrinolysis resulted in the release of fibrin-degradation products (FDP). Consumption of clotting factors and platelets combined with FDP release may result in decompensation of a chronic DIC state and cause a bleeding diathesis. This case shows the need for complete hematologic evaluation of patients with hemostatic abnormalities.

Aged↗

Myelodysplastic transformation of polycythemia vera: case report and review of the literature.

We report a case of refractory anemia with excess blasts (RAEB) developing in a 67-year old man with a history of polycythemia vera; results of cytogenetic and immunophenotyping studies are described. In this report the clinical, cytogenetic and hematologic features of myelodysplasia complicating polycythemia vera are reviewed. Results of immunophenotyping and cytogenetic studies, and the preponderance of cases developing after myelosuppressive therapy suggest that in the majority of cases myelodysplasia is treatment-related.

Aged↗

Malignant thymoma associated with peripheral T-cell lymphocytosis.

Three cases of peripheral T-cell lymphocytosis associated with thymoma are described. Each patient had a malignant, predominantly lymphocytic thymoma with resolution of lymphocytosis upon treatment of the epithelial neoplasm. These findings suggest that lymphocytosis complicating thymoma is a paraneoplastic phenomenon and is not part of the neoplastic process.

Adult↗

A phase I trial of 14-day continuous intravenous infusion mitoxantrone.

Based on clinical evidence that prolonged exposure to anti-neoplastic agents may ameliorate dose-limiting toxicity while facilitating anti-tumor activity, we conducted a phase I trial of 14-day continuous intravenous infusion mitoxantrone. Study objectives were to: (1) determine the maximally tolerated dose for phase II trials; (2) determine the incidence and severity of side effects; and (3) study the pharmacokinetics of continuous infusion mitoxantrone. Sixteen patients with drug-resistant advanced cancers were entered into the trial. Three or more patients were treated at each dose level (1.0, 1.25, and 1.5 mg/m2/day) for a total of 33 courses (mean 2.1 courses/patient, range, 1-4). Courses were repeated every 4 weeks. The maximally tolerated dose (MTD) was found to be 1.5 mg/m2/day. At this dose four of six patients had grade III or IV leukopenia (mean WBC nadir 1900/microliters, range, 800-3600/microliters). Other toxicities were grade I or II stomatitis (two patients), grade I diarrhea (one patient), and grade I nausea (one patient). Renal and hepatic toxicity were not observed. No alopecia or infectious complications occurred. Pharmacokinetic studies were performed using high-performance liquid chromatography (HPLC). Steady-state plasma levels at the 1.5 mg/m2/day dose were reached by 48 h, with a mean steady-state plasma concentration of 3.2 +/- 0.7 ng/ml, mean total body clearance of 340 +/- 79 ml/min/m2, and mean area under the plasma disappearance curve (AUC) of 955 +/- 185 micrograms h/l. No responses were observed, although no patients with mitoxantrone-sensitive tumors were treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Expression of the multidrug resistance gene product (P-glycoprotein) in myelodysplasia is associated with a stem cell phenotype.

Previous studies have indicated relative resistance to chemotherapy in the myelodysplastic syndromes (MDS) and associated acute leukaemia. To determine if multidrug resistance may contribute to chemoresistance in these disorders, we studied bone marrow specimens for P-glycoprotein expression (P-GP) by immunocytochemical staining with monoclonal antibodies reactive with cytoplasmic (C219) or surface epitopes (MRK16) of P-GP. Forty-five case specimens from 43 patients were studied, including 32 cases of primary MDS, seven cases of acute myeloid leukaemia (AML) following MDS, and six therapy-related haematological disorders. Cytogenetic analysis was available on 36 specimens. Two staining patterns were detected: (1) cytoplasm and plasma membrane, and (2) staining restricted primarily to the nuclear-cytoplasmic junction. P-GP was detected in seven (22%) cases of primary MDS, four (57%) cases of AML evolving from MDS, and five (83%) cases of therapy-related haematological disorders. Expression of P-GP was restricted to blasts and leukaemic monocytes, and was otherwise absent from terminally differentiated blood cells. Analysis of the relation between P-GP expression and reactivity with the human progenitor cell antigen CD34, revealed a highly significant association (P = 0.001). P-GP reactivity was distributed equally among normal and abnormal karyotypes and did not correlate with specific cytogenetic abnormalities. These findings indicate that multidrug resistance in MDS and karyotypically-related haematological disorders is closely linked to a stem cell phenotype and may contribute to chemoresistance in these disorders.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Acute myelofibrosis: response to recombinant human interferon alpha-2a.

Acute myelofibrosis is a rare myeloproliferative syndrome characterized by bone marrow proliferation of atypical megakaryocytes, poor response to conventional leukemic therapy, and a fulminant clinical course. Because alpha interferon exhibits potent antiproliferative effects against megakaryocyte progenitors and human fibroblast cell lines, we treated two patients with acute myelofibrosis or the related syndrome of acute myelodysplasia with myelofibrosis with recombinant human interferon alpha-2a. Patient 1 received a 12-week course of interferon alpha (1-6 x 10(6) IU/d) after failure of two cytarabine-based chemotherapy regimens. Interferon administration resulted in prompt improvement in symptoms, stabilization of leukocyte count, and a reduction in circulating blast forms. Primary treatment with interferon (1-3 x 10(6) IU/d x 4 weeks) in patient 2 produced complete hematologic recovery with restoration of marrow cellularity and reduced marrow fibrosis. Our findings suggest that interferon alpha may have significant activity in the treatment of patients with acute myelofibrosis.

Acute Disease↗

Spinal cord toxicity complicating treatment with cisplatin and etoposide.

Neurologic toxicity occurring in patients treated with cisplatin chemotherapy is limited primarily to peripheral neuropathy and ototoxicity. Lhermitte's sign, electric-like paresthesias precipitated by cervical spine flexion, has recently been described as a self-limited complication in cisplatin-treated patients. We report the development of Lhermitte's sign accompanied by cervical motor neuropathy, dorsal column myelopathy, and sensory neuropathy in a patient treated with cisplatin and etoposide for small cell lung cancer. Persistence of the neurologic deficit suggests that potentially irreversible spinal cord toxicity may complicate treatment with this chemotherapy combination.

Aged↗

The myelodysplastic syndromes: biology and implications for management.

Since the initial efforts to characterize the myelodysplastic syndromes in 1976, an extensive body of information has accumulated defining biologic features and the relation to clinical aspects of disease. While the pathogenesis of these disorders remains incompletely understood, laboratory investigations indicate that they are clonal disorders affecting hematopoietic stem cells characterized by a progressive imbalance between self-renewal and differentiation. Despite karyotypic resemblance to acute myeloid leukemia, fundamental biologic differences may underly the disappointing results achieved to date with intensive chemotherapy. The recent availability of recombinant hematopoietic growth factors for use in clinical trials has shown that the maturation defect in many instances can be overcome with administration of lineage-restricted recombinant hematopoietins. Routine use of these promising agents must await results of randomized clinical trials to determine the impact of prolonged treatment on leukemic evolution and disease-related morbidity.

Bone Marrow Transplantation↗

Primary brain lymphoma in the immunocompetent host: relation to Epstein-Barr virus.

Epstein-Barr virus has been implicated in the pathogenesis of primary brain lymphoma in patients with congenital or acquired immunodeficiency states. To examine its role in central nervous system (CNS) lymphoma in the immunocompetent host, Epstein-Barr virologic studies were performed in six consecutive cases seen at our institutions. Virus DNA sequences were detected in only one of three tumor specimens studied by Southern blot hybridization. Serologic studies from the entire cohort disclosed past virus infection; however, antibody reactivity to virus-specific antigens in cerebrospinal fluid was limited to the patient harboring genome-positive tumor. Immunologic studies revealed hyperimmunoglobulin-E (range, 720 to 1040 micrograms/ml) in each of four patients tested. Our findings suggest that Epstein-Barr virus is an infrequent pathogen in nonimmunosuppressed patients with primary CNS lymphoma. Abnormalities in isotype-specific regulation of IgE production are common in such patients and may have pathogenetic implications.

Aged↗

Primary lymphoma of the central nervous system. A report of 20 cases and a review of the literature.

Twenty patients with primary non-Hodgkin's lymphoma of the central nervous system (CNS) were seen at Vanderbilt and its affiliated hospitals between 1974 and 1986. Histologically, the most common subtypes were large, noncleaved cell lymphoma and immunoblastic lymphoma of B cells. However, multiple histologies were identified. Lesions most commonly involved the frontal lobes and/or deep nuclei. Positive cerebrospinal fluid cytology was rare at initial presentation. Seventeen patients were treated with surgical biopsy or resection followed by whole brain radiotherapy at a median dose of 5,000 cGy (range: 3,000-5,600 cGy). Seven patients have been followed for less than 12 months since diagnosis. Of the remaining patients, 7 (54%) survived at least 1 year. The extent of surgery performed, dose of radiotherapy administered, subclass of lymphoma diagnosed, or location(s) of involvement within the CNS did not influence survival. Treatment rarely caused a dramatic improvement in performance status despite objective signs of response. New treatment strategies are needed to improve the management of these tumors.

Adult↗

Thrombosis associated with procainamide-induced lupus anticoagulant.

A predisposition to thrombosis in patients with procainamide-induced lupus anticoagulants is previously unrecognized. We describe two patients treated with procainamide who experienced acute thromboembolic events temporally associated with development of the lupus anticoagulant. One patient had a deep venous thrombosis and pulmonary embolism, while the other patient had a cerebrovascular accident. In both patients, coagulation parameters corrected with interruption of procainamide therapy. We suggest that thrombosis may complicate treatment with procainamide in patients who develop the lupus anticoagulant.

Aged↗