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Biomedical subjects

N J Winick

Publications and source records attributed to N J Winick.

29 records · Page 2Linked to original sources
PubMed1993

Subacute measles encephalitis in the young immunocompromised host: report of two cases diagnosed by polymerase chain reaction and treated with ribavirin and review of the literature.

Two young patients with subacute measles encephalitis are described: a 20-year-old male hemophiliac infected with human immunodeficiency virus (HIV) and a 4-year-old girl with acute leukemia. Both patients were afebrile and had persistent focal seizures and slurred speech beginning 2 and 7 months, respectively, after the onset of uncomplicated acute measles. The diagnosis of subacute measles encephalitis was established by demonstration of paramyxovirus nucleocapsid on electron microscopy of brain tissue in one case and by detection of measles virus genome with the polymerase chain reaction in both. Treatment of the HIV-infected man with intravenous ribavirin was begun when the patient lost consciousness after several weeks of seizures; he died. The girl with leukemia was treated early after the onset of symptoms and recovered after a 15-week course. Review of 31 previously published cases revealed a typical clinical presentation. Cerebrospinal fluid (CSF) analysis, electroencephalography, measurement of measles antibody in serum and CSF, and computed tomography of the brain were not helpful in the diagnosis of subacute measles encephalitis. In contrast, histologic examination of brain tissue proved useful in establishing the diagnosis. On the basis of our experience and our literature review, we conclude that histologic and polymerase chain reaction studies of brain tissue are required for the early diagnosis of subacute measles encephalitis and that therapy with intravenous ribavirin is effective when administered early.

Adult↗
PubMed1993

Secondary acute myeloid leukemia in children with acute lymphoblastic leukemia treated with etoposide.

PURPOSE: To describe the occurrence of secondary acute myeloid leukemia (AML) in children with acute lymphoblastic leukemia (ALL) treated with etoposide (VP-16). PATIENTS AND METHODS: Two hundred five consecutive children with early B-lineage ALL were treated according to the Dallas/Fort Worth (DFW) protocol between January 1986 and July 1, 1991. Therapy included a four-drug induction followed by consolidation and continuation phases of nightly oral mercaptopurine (6-MP) and repetitive courses of divided-dose oral methotrexate (dMTX) and asparaginase (L-asp). Three doses of VP-16 and cytarabine (Ara-C) were given during consolidation and later, during continuation, two doses were given 3 to 4 days apart, every 9 weeks. Intrathecal (IT) chemotherapy was given throughout the treatment period. RESULTS: Two hundred three of the 205 patients entered remission. Only eight of these 203 children have had a bone marrow relapse (ALL). However, 10 other children have developed secondary AML 23 to 68 months following the diagnosis of ALL. Overall event-free survival (EFS) at 4 years is 79.3% +/- 5.1%, with a risk of secondary AML at 4 years of 5.9% +/- 3.2%. CONCLUSION: This experience provides strong evidence for a link between epipodophyllotoxin therapy and secondary AML since none of these children received alkylating agent therapy or irradiation. This serious complication raises concern as to the appropriate use of epipodophyllotoxins in the treatment of childhood ALL.

Acute Disease↗
PubMed1993

Treatment of CNS relapse in children with acute lymphoblastic leukemia: A Pediatric Oncology Group study.

PURPOSE: To assess the efficacy and toxicity of chemotherapy and cranial radiation for the treatment of children with acute lymphoblastic leukemia (ALL) following first isolated CNS relapse. PATIENTS AND METHODS: One hundred twenty children were treated on Pediatric Oncology Group (POG) protocol 8304. All children had received prophylactic CNS therapy during their initial treatment. The treatment protocol included a four-drug reinduction and six weekly doses of triple intrathecal therapy (TIT). Cranial radiation, 24 Gy, was followed by monthly TIT. Systemic consolidation and maintenance therapy included 6-week cycles of mercaptopurine/methotrexate (6MP/MTX) and vincristine/cyclophosphamide (VCR/CTX), with randomization to intervening pulses of prednisone/doxorubicin (PDN/DOX) or teniposide (VM26)/cytarabine (Ara-C) for a total of 88 weeks. RESULTS: All 120 patients achieved a second complete remission. There have been 61 protocol failures. Thirty-five patients had a bone marrow relapse, four with simultaneous CNS involvement and one with concurrent testicular leukemia. Thirteen patients had a second isolated CNS relapse, 10 a testicular relapse, and two relapsed in other sites. One patient died in remission. Overall event-free survival (EFS) at 4 years was 46% +/- 7%. The toxicity associated with this protocol was minimal except for leukoencephalopathy, which occurred in 20 (17%) patients. The treatment comparison between VM26/Ara-C or PDN/DOX pulses showed a trend toward superior EFS (P = .12) in favor of VM-26/Ara-C. CONCLUSION: To date, this represents the largest series of patients with ALL treated uniformly for an isolated CNS relapse. Since marrow relapse remains the primary site of failure, future protocols must intensify systemic therapy.

Adolescent↗
PubMed1992

Frequency and diversity of p53 mutations in childhood rhabdomyosarcoma.

The p53 gene was examined in primary or metastatic tumors from six patients with rhabdomyosarcoma (RMS) and in five RMS cell lines by screening methods including single-strand conformation polymorphism analysis, the RNase protection assay, sequencing of complementary DNA subclones, and Southern blotting. Six original tumors were of embryonal histology, four alveolar, and one mixed. p53 mutations were identified in four of the six tumors or cell lines derived from tumors with embryonal histology and in one of the four with alveolar histology. Consistent with p53 allele loss, each mutation was found in the homo- or hemizygous state. One tumor showed a G to C transversion at p53 codon 213 (arginine to proline), and another showed deletion of the entire gene. The p53 mutations in cell lines included a codon 248 C to T transition (arginine to tryptophan) in RD and a codon 280 A to T transversion (arginine to serine) in RH30. The cell line CTR contained a 4-base pair deletion at codons 219/220 in exon 6 with resultant frame shift and premature termination in exon 7. These data support the role of diverse types of p53 mutations in the pathogenesis and/or progression of a significant proportion of cases of childhood RMS.

Adolescent↗
PubMed1992

Unexpected acute neurologic toxicity in the treatment of children with acute lymphoblastic leukemia.

BACKGROUND: Our current protocol for treatment of childhood acute lymphoblastic leukemia (ALL) was designed to assess the efficacy of methotrexate (MTX) plus L-asparaginase and of etopisode (VP-16) plus cytarabine (ARA-C) during intensive consolidation and continuation therapies and to determine the feasibility of intensifying MTX therapy by the use of divided oral doses of MTX. The protocol was associated with unexpected acute neurotoxicity. There are few reports of such toxic effects during therapy for ALL. PURPOSE: This report describes these toxic effects and outlines our successful approach to the problem. METHODS: The standard four-drug induction regimen consisted of vincristine, L-asparaginase, daunorubicin, and prednisone. In consolidation therapy, oral MTX was given in divided doses (dMTX) of 25 mg/m2 every 6 hours four times daily in four weekly courses concomitant with weekly triple intrathecal therapy--MTX, ARA-C, and hydrocortisone--plus one dose of leucovorin 24 hours after triple intrathecal therapy. Consolidation treatment ended with three daily doses of intravenous VP-16 and ARA-C. The first 16 months of continuation therapy included 6-week cycles of dMTX and L-asparaginase, both given every other week for 5 weeks, with 6-mercaptopurine nightly, and then two doses of VP-16 plus ARA-C and one dose of triple intrathecal therapy. RESULTS: Twenty-five of the 138 patients evaluated had acute neurotoxicity. Ten of the first 72 experienced a seizure or episode of transient neurological deficit 9-11 days following the administration of intravenous ARA-C, VP-16, and triple intrathecal therapy. Despite discontinuation of intrathecal ARA-C, which eliminated simultaneous intravenous and intrathecal treatment with ARA-C, acute neurotoxicity was observed in six previously unaffected patients and six of 42 patients treated after the elimination of intrathecal ARA-C. Therefore, as a second amendment, oral leucovorin was given 24 and 36 hours after dMTX and intrathecal MTX in continuation therapy. No acute neurotoxicity has been seen in 24 patients subsequently entered in the study. CONCLUSION: These findings suggest that folate replacement due to administration of leucovorin modulated MTX toxicity and/or modified an interaction among VP-16, ARA-C, intrathecal therapy, and the central nervous system.

Adolescent↗
PubMed1987

Methotrexate (MTX) concentration in tumors following low-dose MTX.

Methotrexate (MTX) is a folate analog competitive with reduced folates for cellular transport and metabolism. Since the normal plasma folate concentration is only 10(-8) M, we tested the possibility that there may be a saturable uptake of MTX by proliferating tumor tissue at plasma MTX concentrations of only 10(-7) to 10(-6) M. Patients with advanced malignancies, refractory to accepted therapy, were given low-dose oral MTX (30-60 mg/m2 total dose in four to eight divided doses). Tumor tissue was biopsied 18-24 h after the last oral dose of MTX. The concentrations of MTX and its polyglutamated derivatives were measured in these samples. Forty-eight percent of the drug in the tumor samples was present as a polyglutamated derivative.

Administration, Oral↗
PubMed1987

Folate and methotrexate polyglutamate tissue levels in rhesus monkeys following chronic low-dose methotrexate.

Methotrexate (MTX), a mainstay in the treatment of acute lymphoblastic leukemia, is associated with both hepatic and neurologic toxicity. Like a folate, MTX is metabolized to polyglutamated derivatives (MTXGlun) with long intracellular half-lives. These metabolites may contribute to MTX toxicity through a direct effect on cellular metabolism or indirectly through a perturbation of folate homeostasis. To better define the effects of chronic MTX treatment, tissue levels of MTX, MTXGlun, and folate were measured in three monkeys treated with weekly intramuscular MTX for 1 year. Greater than 80% of the total tissue MTX found was in the form of polyglutamated derivatives. Most of these derivatives were MTXGlu3-5 but Glu6-7 were easily detectable. Total tissue folates were measured in liver, kidney, brain and testis with MTX treated animals having a 90% loss of total folate in brain tissue. This is of special interest since inborn errors of folate metabolism are often associated with severe neurologic abnormalities.

Animals↗
PubMedDate not supplied

Epstein-Barr virus lymphoproliferative disorder in children with leukemia: case report and review of the literature.

PURPOSE: The purpose of this study is to report a case of Epstein-Barr virus-related lymphoproliferative disorder (EBV-related LPD) in a child with leukemia and present a review of literature on the subject. PATIENTS AND METHODS: A 6-year-old boy with acute lymphoblastic leukemia (ALL) undergoing maintenance chemotherapy presented with fever, abdominal pain, and vomiting. Imaging studies revealed multiple mass lesions in the liver, kidneys, and lungs. Liver biopsy was obtained. Immunocytochemistry for T and B lymphocytes and in situ hybridization for evidence of latent EBV infection was performed. RESULTS: Hepatic portal tracts were infiltrated with lymphocytes, monocytes, eosinophils, and large atypical mononuclear cells. Both T and B lymphocytes were present, but the large atypical cells were of B origin and were positive for latent EBV infection. Chemotherapy was discontinued, and the patient was treated with intravenous gammaglobulin, interferon, and acyclovir. He had an excellent response and has been free of disease for 19 months. CONCLUSION: EBV-related LPD can complicate the course of patients with ALL in remission. The clinical findings and diagnosis in patients with ALL are similar to other immunocompromised patients. Withdrawal of chemotherapy and treatment with immune modulators should be strongly considered.

Child↗
PubMedDate not supplied

Immune recovery in children with malignancy after cessation of chemotherapy.

PURPOSE: To study longitudinally the extent and recovery of cellular and humoral immune alterations in children with cancer after completion of their therapy. PATIENTS AND METHODS: Using standard immune assays, cellular and humoral immunity was measured in 43 infants and children with cancer at completion of therapy and every 3 months thereafter for 1 year. There were 17 patients with acute lymphoblastic leukemia, 9 with Hodgkin disease, and 17 with solid nonhematopoietic tumors. All children had received standard childhood immunizations before diagnosis of cancer. Immune assays performed included circulating lymphocyte subpopulations, in vitro antigen-induced responses, and total concentrations of serum immunoglobulin G (IgG), IgM, IgA, and IgG subclasses, and specific antibodies against diphtheria, tetanus, pertussis, and poliovirus types I, II, and III. RESULTS: At completion of therapy, the majority of patients had low circulating lymphocyte subpopulations and antigen-induced responses. Serum antibody concentrations were low in up to 89% of patients regardless of the underlying malignancy. Although improvement occurred during the year of follow-up, 35 of 43 (81%) patients continued to exhibit one or more immune abnormalities 9 to 12 months after cessation of chemotherapy. Younger patients had more persistent alterations. Other risk factors studied (including gender, duration of therapy, and underlying malignancy) did not correlate with the severity of the immune defects. With the exception of poliovirus antibodies, specific antibody titers against common childhood vaccine antigens were deficient at completion of therapy and 9 to 12 months later in a substantial proportion of patients. CONCLUSION: Children with malignancy have persistent specific and nonspecific immune alterations 9 to 12 months after cessation of chemotherapy. The clinical implications of these in vitro observations are unclear and require further evaluation.

Adolescent↗
PubMedDate not supplied

Evidence for negative feedback of extracellular methotrexate on blasts of acute lymphoblastic leukemia in vitro.

STUDY OBJECTIVE: To explore the value of high-dose methotrexate (MTX). SUBJECTS: Blast cells from 15 patients with acute lymphoblastic leukemia. INTERVENTIONS: We compared uptake and polyglutamation of [3H]-MTX by freshly isolated leukemic blasts in vitro after 24-hour exposure to 1, 10, and 50 microM [3H]-MTX. MEASUREMENTS AND MAIN RESULTS: Mean MTX uptake (pmol/10(6) cells) was 0.78 +/- 0.19, 2.3 +/- 0.54, and 5.9 +/- 1.9, respectively, and mean polyglutamation was 82%, 66%, and 46%. Consequently, mean MTX polyglutamates were 0.68 +/- 0.18, 1.5 +/- 0.47, and 2.2 +/- 0.67 pmol/10(6) cells. Three of 15 patient samples had no detectable polyglutamation of MTX at 50 microM but MTX polyglutamates were detectable at 1 microM. Two of these three had a decrease in MTX polyglutamates at 10 versus 1 microM. In eight precursor B cell samples there was a significant difference in median MTX polyglutamates at 1 versus 10 microM but not 10 versus 50 microM. CONCLUSION: Increasing extracellular MTX concentrations may be counterproductive for some patients with acute lymphoblastic leukemia. If MTX polyglutamates are important for efficacy, optimal delivery of MTX may have to be determined by individual metabolism rather than by targeting a specific drug concentration.

Antimetabolites, Antineoplastic↗