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Biomedical subjects

A H Ragab

Publications and source records attributed to A H Ragab.

At least 19 recordsLinked to original sources
PubMed1995

The Third Intergroup Rhabdomyosarcoma Study.

PURPOSE: The ultimate goal of the Third Intergroup Rhabdomyosarcoma Study (IRS-III, 1984 to 1991) was to improve treatment outcome in children with rhabdomyosarcoma through clinical trials comparing risk-based protocols of surgery and multiagent chemotherapy, with or without irradiation. PATIENTS AND METHODS: One thousand sixty-two previously untreated, eligible patients who were entered onto the study after surgery were randomized or assigned to treatment by clinical group (I through IV), histology (unfavorable or favorable), and site of the primary tumor. Initial responses, progression-free survival (PFS), and survival (S) were the end points used in comparisons between randomized groups and between patients treated in IRS-III and IRS-II (1978 to 1984). RESULTS: The overall outcome of therapy in IRS-III was significantly better than in IRS-II (5-year PFS, 65% +/- 2% v 55% +/- 2%; P < .001 by stratified testing). Patients with group I favorable-histology tumors fared as well on a 1-year regimen of vincristine and dactinomycin (VA), as did a comparable group treated with VA plus cyclophosphamide (C) (5-year PFS, 83% +/- 3% v 76% +/- 4%; P = .18). Results for patients with group II favorable-histology tumors, excluding orbit, head, and paratesticular sites, were inconclusive regarding the benefit from addition of doxorubicin (ADR) to VA. Patients with group III tumors, excluding those in special pelvic, orbit, and other selected nonparameningeal head sites, fared much better on the more intensive regimens of IRS-III than on pulsed VAC or VAC-VADRC in IRS-II (5-year PFS estimates, 62% +/- 3% v 52% +/- 3%; P < .01); however, there were no significant differences in outcome among the groups treated in IRS-III. Patients with metastatic disease at diagnosis (clinical group IV) did not benefit significantly from the more complex therapies evaluated in IRS-III. CONCLUSION: Intensification of therapy for most patients in IRS-III, using a risk-based study design, significantly improved treatment outcome overall. The largest gain from this strategy was realized in patients with gross residual tumor after biopsy (clinical group III). It was also possible to decrease therapy for selected patient subsets without compromising survival.

Adolescent↗
PubMed1994

Characterization of a myeloperoxidase mRNA(+) acute lymphoblastic leukemia cell line (EU-1/ALL) established from a child with an apparent case of ALL.

A myeloid-antigen-positive acute lymphoblastic leukemia (My+ALL) cell line (EU-1) was established from the bone marrow cells of a child with apparent ALL. By morphology, cytochemistry and fluorescent-antibody phenotyping, EU-1 cells appeared to be lymphoblastic (L1 morphology, TdT+, CD10+, CD19+). However, by a sensitive immunocytochemical assay, EU-1 cells additionally displayed several myeloid antigens (CD13, CD14, CD33) not detected by flow-cytometry. Furthermore, EU-1 cells were cytochemically and immunocytochemically negative for myeloperoxidase (MPO) but positive for MPO mRNA by Northern blot analysis. After incubation with dimethylsulfoxide (DMSO), myeloid cell surface antigens were detected on EU-1 cells by flow cytometry, and a marked decrease in MPO mRNA expression was observed. These results demonstrate that EU-1 is a unique ALL cell line representing a significant subset of pediatric ALL patients who also express myeloid antigens and have poor prognosis.

Adolescent↗
PubMed1993

Alveolar rhabdomyosarcoma with the t(2;13): cytogenetic findings and clinicopathologic correlations.

We describe here the clinical and pathologic features associated with a specific translocation, t(2;13), in alveolar rhabdomyosarcoma. Tumor specimens from 14 patients with a t(2;13)-positive alveolar rhabdomyosarcoma were studied for cytogenetic-clinicopathologic correlations. Three patients had occult primary tumors; nine patients had primary tumors of the trunk (mediastinal, pelvic, or rectal). The presence of the t(2;13) was ascertained from examination of tumor involved bone marrow in ten patients who had widespread metastatic disease at the time of diagnosis. Marrow involvement was so extensive in three cases that they were initially diagnosed as acute leukemia. Response to therapy was poor, with only five patients achieving a complete response. Twelve patients have died of their disease at a median survival time of 6 months from diagnosis and one is living with recurrent disease; only one patient survives free of disease.

Adolescent↗
PubMed1993

Phase I trial of paclitaxel in children with refractory solid tumors: a Pediatric Oncology Group Study.

PURPOSE: A phase I study was performed to describe the principal toxicities and identify the maximum-tolerated dose (MTD) of Taxol (paclitaxel; Bristol-Myers Squibb Co, Wallingford, CT) in children with therapy-resistant solid tumors. Additionally, the pharmacokinetic disposition of Taxol in children was studied, and preliminary evidence of the activity of Taxol against pediatric solid tumors was assessed. PATIENTS AND METHODS: Twenty-four-hour continuous infusions of Taxol were administered every 21 days to children (median age, 12 years; range, 2 to 22) with refractory solid tumors. Doses ranged from 200 to 420 mg/m2, there was no intrapatient dose escalation. RESULTS: A total of 62 courses of Taxol were administered to 31 patients. Two patients developed acute anaphylaxis during their second infusion of taxol at doses of 200 mg/m2 and 350 mg/m2, respectively. No other allergic reactions were documented. Myelosuppression occurred at all dose levels, but was of short duration (< or = 7 days) and did not appear to increase with consecutive courses or at higher dosage levels. A stocking-and-glove peripheral neuropathy became evident at doses > or = 290 mg/m2. Dose-limiting neurotoxicity occurred at 420 mg/m2 and comprised a significant fine-motor and peripheral neuropathy in one patient, and a tonic-clonic seizure in another. End-of-infusion plasma concentrations ranged from 0.40 to 6.4 mumol/L, and were not found to be dose-dependent over the range of doses studied. A complete response was documented in one patient, partial response in two, and minimal response in one for an overall response rate of 13%. CONCLUSION: Neurotoxicity was dose-limiting when Taxol was administered by 24-hour continuous infusion to pediatric patients with relapsed solid tumors. In this population, the recommended dose for phase II trials is 350 mg/m2/d.

Adolescent↗
PubMed1993

Second malignant neoplasms in children treated for rhabdomyosarcoma. Intergroup Rhabdomyosarcoma Study Committee.

PURPOSE: This study was performed to determine the incidence and risk factors involved in the development of a second malignant neoplasm (SMN) after treatment of primary rhabdomyosarcoma (RMS) in patients enrolled onto Intergroup Rhabdomyosarcoma Studies I and II (IRS I and II). PATIENTS AND METHODS: There were 1,770 patients with primary RMS entered onto IRS I and II between 1972 and 1984. They were treated with chemotherapy and, in most instances, radiotherapy according to randomized or assigned regimens based on clinical grouping. Median follow-up time for these patients was 8.4 years. Incidence density (ID) was calculated for each study and for treatment and age groups. The 10-year cumulative incidence was estimated for each study. RESULTS: Twenty-two SMNs have been reported through 1991. The most common tumor type was a bone sarcoma followed by acute nonlymphoblastic leukemia (ANLL). The median time to the development of an SMN was 7 years (range, 1 11/12 to 15 9/12 years). The 10-year cumulative incidence rate was 1.7% for both studies. ID and cumulative incidence estimates were highest for patients who received both an alkylating agent and radiotherapy. The majority of patients for whom family histories were available had either neurofibromatosis themselves or a family history that suggested the Li-Fraumeni syndrome (LFS). CONCLUSION: The results of this study suggest that genetic abnormalities play a prominent role in the development of an SMN after therapy for a primary RMS. Chemotherapy with an alkylating agent and radiotherapy play significant roles in the development of an SMN compared with patients who received only one of these therapeutic modalities.

Adolescent↗
PubMed1993

Effects of IL-7 on human lymphocytes.

Interleukin-7 (IL-7) is known as a growth factor for pre B-cell and mature T-cells in human. But in leukemic cells, IL-7 effect is variously reported. To investigate the effect of IL-7 on the cells of childhood acute leukemia we used 3H-Thymidine assay. Twelve Acute lymphoblastic leukemia (ALL), seven T-ALL and three Acute myelogenous leukemia (AML) were involved in this study. Two out of twelve ALL and three out of seven T-ALL bone marrow (BM) cells were stimulated by IL-7 in 3H-Thymidine incorporation. In normal and AML BM cells, IL-7 had no stimulatory activity as in various leukemic cell lines. Two normal peripheral blood T-cells responded to IL-7 dose dependently. We have seen the effect of IL-7 to stimulate T-lineage cells but, for precise conclusion, further study using more purified samples will be needed.

Adolescent↗
PubMed1993

Expression of myeloperoxidase mRNA by leukemic cells from childhood acute lymphoblastic leukemia.

The frequency of acute lymphoblastic leukemia (ALL) expressing the myeloperoxidase (MPO) gene and other myeloid-associated characteristics was determined in 26 (20 B-lineage, six T-lineage) children at diagnosis. All cases were diagnosed as ALL by standard morphological and cytochemical criteria. In the 26 cases, leukemic blast cells from four B-lineage and two T-lineage ALL patients were simultaneously expressing myeloid-associated antigens. By Northern blot analysis, MPO mRNA was detected in leukemic cells from five out of six cases expressing both lymphoid and myeloid antigens, and from four out of 16 B-lineage and one out of four T-lineage ALL without myeloid antigens. There was no detectable MPO protein or enzymatic activity in the leukemic cells of these cases as examined by immunocytochemistry and cytochemistry. MPO mRNA expression in ALL cells was significantly associated with age < 1 year: leukemic blast cells from all five infant ALL patients expressed MPO mRNA, compared to five out of 21 ALL patients > 1 year of age whose leukemic cells were MPO mRNA(+) (p < 0.01). These results suggest that MPO gene transcription in the absence of translation may characterize a recently described subset of pediatric ALL patients who also express myeloid markers, and may serve as a useful marker for this entity.

Adolescent↗
PubMed1992

Characterization and molecular analysis of nondisjunction in 18 cases of trisomy 21 and leukemia.

We recently began a cytogenetic and molecular study of nondisjunction in leukemic Down syndrome individuals to determine whether the mechanism by which the extra chromosome 21 originates predisposes the individual to leukemia. In the present report, we summarize our observations on 18 patients with trisomy 21 and acute or transient leukemia, including 11 patients with acute lymphocytic leukemia, three with acute myeloid leukemia, one with B-cell lymphoma, one with acute megakaryoblastic leukemia, and two with transient leukemia. Results of DNA marker studies of the parental origin of the extra chromosome 21 indicated that 16 of the 18 cases (89%) were maternally derived, a percentage similar to that seen among nonleukemic Down syndrome patients. We noted that most leukemic Down syndrome patients had one locus or more in which parental heterozygosity was maintained in the trisomic individual, indicating a meiotic rather than a mitotic origin for the trisomy.

Adolescent↗
PubMed1992

A phase II trial of continuous-infusion 6-mercaptopurine for childhood leukemia.

A phase II pediatric trial of a continuous intravenous infusion of 6-mercaptopurine (6MP) in patients with refractory leukemia was performed. The dosing schedule, 50 mg m-2 h-1 for 48 h, was based on the results of a previous phase I trial of this approach. Among the 40 children treated for acute lymphoblastic leukemia (ALL), all of whom had received prior therapy with oral 6MP, 1 complete and 1 partial response were achieved. No response was observed in 17 patients with refractory acute nonlymphocytic leukemia (ANLL). Reversible hepatotoxicity, the primary dose-limiting toxicity, was observed in approximately 50% of cases. Mucositis was encountered infrequently and was usually not severe. 6MP given on the present continuous intravenous infusion schedule overcomes the limited and variable bioavailability of oral 6MP but shows limited activity as induction agent in children with recurrent ALL.

Adolescent↗
PubMed1992

Phase I study of recombinant human interleukin-2 for pediatric malignancies: feasibility of outpatient therapy. A Pediatric Oncology Group Study.

Published data indicate that when recombinant interleukin-2 (rIL-2) is administered to children as a 15-min i.v. bolus, doses of 18 x 10(6) IU/m2 are poorly tolerated, requiring intensive care unit (ICU) management of IL-2-induced hypotension. We administered rIL-2 as a 1- or 2-h i.v. infusion to 11 children with malignancies refractory to conventional therapy. IL-2 was given every Monday/Wednesday/Friday for 3 weeks. Four children received 12 x 10(6) IU/m2/dose, four received 18 x 10(6) IU/m2/dose, and three received 24 x 10(6) IU/m2/dose (1 Cetus Unit = 6 IU). Fever, chills, flushing, nausea, vomiting, transient weight gain, and oliguria were observed at all three dose levels (not dose-limiting toxicities). Cardiovascular toxicity was significantly reduced compared to the bolus regimen. Mild hypotension was observed at all three dose levels; however, there was no severe dose-limiting hypotension. Because of reduced cardiovascular toxicity, IL-2 was safely administered on an outpatient basis. This regimen induced marginal transient increases in natural killer cell activity and lymphokine-activated killer cell activity. No measurable clinical tumor response was observed in any of the 11 children. The maximum-tolerated dose has not been reached. This regimen allows for a considerable cost reduction (outpatient care instead of ICU care) and safety, making further clinical trials on the use of IL-2 in children more feasible.

Adolescent↗
PubMed1992

Treatment of children with progressive or recurrent brain tumors with carboplatin or iproplatin: a Pediatric Oncology Group randomized phase II study.

PURPOSE: The Pediatric Oncology Group (POG) conducted a randomized phase II study to evaluate the activity of carboplatin and iproplatin in children with progressive or recurrent brain tumors. PATIENTS AND METHODS: The study was designed to evaluate the activity of these agents and to compare the toxicities associated with their use. Treatment consisted of carboplatin 560 mg/m2 at 4-week intervals or iproplatin 270 mg/m2 at 3-week intervals. RESULTS: The major toxicity observed was myelosuppression, particularly thrombocytopenia, for both agents. Ototoxicity (grade 1 or 2) was seen in 2.5% of patients treated with carboplatin and 1.3% of patients treated with iproplatin. The majority of patients with low-grade astrocytic neoplasms treated with carboplatin (nine of 12 patients) or iproplatin (eight of 12 patients) demonstrated tumor response or prolonged stable disease that persisted off-therapy. The duration of stable disease produced by carboplatin was particularly striking, ranging from 2 months to 68 + months (median, 40 + months). Neither drug demonstrated appreciable activity in the treatment of medulloblastoma (two of 26 responses to carboplatin, one of 14 responses to iproplatin), ependymoma (two of 17 responses to carboplatin, none of seven responses to iproplatin), high-grade glioma (two of 19 responses to carboplatin, one of 14 responses to iproplatin), or brain-stem tumors (one of 23 responses to carboplatin, none of 14 responses to iproplatin). CONCLUSION: Carboplatin is active against low-grade gliomas. Further evaluation of the role of carboplatin in the preirradiation treatment of children with low-grade gliomas of the optic pathway is currently underway in a clinical trial.

Adolescent↗
PubMed1992

Expression of myeloid-associated and lymphoid-associated cell-surface antigens in acute myeloid leukemia of childhood: a Pediatric Oncology Group study.

PURPOSE: Although the expression of both myeloid- and lymphoid-associated cell-surface antigens in acute myeloid leukemia (AML) has been described, the clinical significance of such antigen expression remains unknown in the pediatric population. We sought to define an antibody panel for optimal diagnostic antigenic analysis and to test associations among antigen expression and a number of clinical features at presentation and prognosis in pediatric AML. PATIENTS AND METHODS: We reviewed the extensive immunophenotypic analysis performed at the time of diagnosis on 132 assessable patients registered on a single Pediatric Oncology Group AML protocol between 1984 and 1988. RESULTS: Eighty-eight percent of patients were identified by testing for expression of CD33 and CD13. Overall, 61% of patients expressed at least one lymphoid-associated antigen, most commonly CD4, CD7, or CD19. Expression of CD5, CD10, CD20, or CD22, commonly detected in T- or B-lineage pediatric acute lymphoid leukemia (ALL), was uncommon; coexpression of multiple lymphoid-associated antigens was also uncommon. Expression of the monocyte-associated antigen CD14 correlated with French-American-British (FAB) M4 or M5 morphology. Otherwise, no correlation between antigen expression and FAB classification was noted. None of the myeloid, lymphoid, natural-killer (NK), or progenitor-associated antigens were associated with significant differences in the likelihood of remission induction or event-free survival when expressor versus nonexpressor groups were compared. CONCLUSIONS: The distribution of cell-surface antigen expression in pediatric acute leukemia usually permitted the discrimination of AML from ALL by using a limited panel of antibodies. Although the expression of lymphoid-associated antigens was common, such expression did not seem to be associated with an adverse prognosis in pediatric AML.

Acute Disease↗
PubMed1992

The effect of recombinant GM-CSF and G-CSF on the bone marrow cells of children with acute lymphoblastic leukemia.

Colony stimulating factors (CSFs) are glycoprotein hormones that regulate growth and differentiation of hematopoietic progenitor cells. Their use to stimulate granulocyte precursors during periods of neutropenia in patients with acute myeloid leukemia (AML) is limited by their concomitant stimulation of the proliferation of myeloblasts. The effects of these agents on leukemic lymphoblasts is not entirely known. We have investigated the in vitro effects of granulocyte-CSF (G-CSF) and granulocyte/macrophage-CSF (GM-CSF) on leukemic cells from children with acute lymphoblastic leukemia (ALL). DNA synthesis of bone marrow cells from 22 children with ALL, either at diagnosis or in relapse, was examined with and without CSFs. Proliferative potential was also tested in a clonogenic assay with 13 bone marrow specimens. These factors did not stimulate the growth of ALL cells in either assay. Our results indicate that G-CSF and GM-CSF should be able to stimulate granulocyte proliferation without enhancing leukemic proliferation during periods of neutropenia in children with ALL.

Bone Marrow↗
PubMed1991

Effect of tumor necrosis factor-alpha on the proliferation of leukemic cells from children with B-cell precursor-acute lymphoblastic leukemia (BCP-ALL): studies of primary leukemic cells and BCP-ALL cell lines.

The effect of recombinant tumor necrosis factor-alpha (rTNF-alpha) on the primary leukemic blasts and leukemic cell lines derived from children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) was studied. The proliferation of leukemic cells from the bone marrow of 11 of 13 patients (seven at diagnosis, four in relapse) and from the 697 (BCP-ALL) cell line was significantly inhibited by rTNF-alpha at the lowest dose tested (0.1 ng/mL), as measured by 3H-TdR uptake. The degree of inhibition was variable, ranging from 17% to 78%. Furthermore, a dose-dependent inhibitory effect was observed, with approximately 70% mean inhibition of DNA synthesis detected when cells from 12 of 13 patients were incubated with 100 ng/mL of rTNF-alpha for 3 days. In contrast, rTNF-alpha did not inhibit another BCP-ALL cell line (EU-1/ALL) established recently in our laboratory. Studies indicated that the TNF-alpha gene was expressed by the primary leukemic blasts of one TNF-resistant case in his third relapse and by EU-1 cells. Also, TNF-alpha protein was detected by Western blot analysis and enzyme-linked immunoabsorbent assay in the supernatant of EU-1 cells; this is the first report of TNF production by a BCP-ALL cell lines. The production of TNF-alpha mRNA and protein was not detected in the 697 cell line and in the primary leukemic blasts from six patients (four at diagnosis, two in relapse) whose leukemic cells were inhibited by TNF. The partially purified TNF-alpha obtained from the EU-1 cell line also suppressed the proliferation of TNF-sensitive primary leukemic cells, and this inhibitory activity was abolished by an anti-TNF-alpha specific antibody. Our results demonstrate that TNF-alpha is an inhibitor of in vitro proliferation of BCP-ALL cells from most patients. The TNF-resistant leukemic cells from a few patients and the EU-1 cell line express TNF mRNA, suggesting that the induction of TNF gene expression is associated with the development of TNF resistance.

Blotting, Western↗
PubMed1991

Clinical characteristics and treatment outcome of children with acute lymphocytic leukemia and Down's syndrome. A Pediatric Oncology Group study.

Of 2947 children with acute lymphocytic leukemia (ALL), treated during three consecutive studies of the Pediatric Oncology Group (1974-1986), 52 (1.8%) had Down's Syndrome (DS). Comparison of clinical and laboratory characteristics showed no significant differences in leukocyte count, racial distribution, sex ratio, platelet count, incidence of mediastinal mass, lymphadenopathy or hepatosplenomegaly, or percentage of blood or bone marrow blasts for children with ALL with or without Down's Syndrome (DS-ALL or NDS-ALL, respectively). However, children with DS-ALL were slightly older at the time of presentation and had higher hemoglobin values. The relative frequency of each major immunophenotype (early pre-B, pre-B, T, or B) was also comparable for patients with or without DS. For this report, treatment regimens were categorized as either conventional (no consolidation therapy) or intensive. Cox regression analysis revealed that the presence of DS, a higher leukocyte count, black race, or age older than 10 years was independently associated with a poorer event-free survival (EFS) for children treated with conventional chemotherapy. However, for the cohort of children who received intensive chemotherapy, DS was no longer an independent risk factor. In fact, event-free survival (EFS) was markedly improved to a level comparable with that observed in the children diagnosed as having NDS-ALL. On the other hand, serious toxicity, requiring interruption of treatment, was significantly more frequent in the intensively treated children with DS compared with similarly treated patients with NDS-ALL, although deaths resulting from toxicity occurred infrequently.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Phase II trial of mitoxantrone in acute lymphocytic leukemia of childhood. A Pediatric Oncology Group study.

Thirty children with refractory acute lymphocytic leukemia (ALL) were treated with mitoxantrone, 8 mg/m2/day, for 5 days. Three children received a second course of the drug 3 to 4 weeks later. All but two patients had received prior anthracycline therapy. There were 2 complete responses, 4 early deaths, and 24 patients with persistent leukemia. Of the 21 patients with circulating blasts at the start of mitoxantrone who did not achieve remission, 16 (76%) had complete clearance of their peripheral blood blasts. Although all patients developed profound neutropenia (less than 100 per mm-3), mucosal and hepatic toxicities were uncommon and mild. Mitoxantrone has moderate activity in childhood ALL and should be considered for further trials in less heavily pretreated patients.

Adolescent↗
PubMed1991

In vitro enhancement of natural killer cell activity against herpesvirus-infected targets in patients with acute lymphocytic leukemia.

The present study was carried out to determine whether natural killer (NK) activity against virus-infected target cells could be enhanced in peripheral blood lymphocytes (PBL) taken from patients with acute lymphocytic leukemia. Nonspecific cell-mediated killing of heterologous herpesvirus-infected B lymphoblastoid targets could be enhanced by pretreating PBL with interferons-alpha or -gamma, or with interleukin-2. NK activity was substantially enhanced over that of untreated cells, and virtually all cytolytic activity was attributable to CD16+ NK cells. Pretreatment of PBL with a combination of cytokines resulted in additive, but never synergistic enhancement of NK activity. The results suggest that cytokine therapy may provide a useful means for treating severe varicella zoster infections in immunocompromised children.

Cell Line, Transformed↗