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Biomedical subjects

J D Buckley

Publications and source records attributed to J D Buckley.

At least 55 records · Page 3Linked to original sources
PubMed1994

Chemotherapy for induction of remission of childhood acute myeloid leukemia followed by marrow transplantation or multiagent chemotherapy: a report from the Childrens Cancer Group.

PURPOSE: In an effort to evaluate the usefulness of bone marrow transplantation, the Childrens Cancer Group (CCG) initiated a multiinstitutional study comparing bone marrow transplantation versus chemotherapy after successful induction of remission for previously untreated children and young adults with acute myeloid leukemia. PATIENTS AND METHODS: From 1979 to 1983, 508 patients were entered onto this study and 490 were treated. After induction, patients with an HLA mixed leukocyte culture (MLC)-compatible sibling underwent bone marrow transplantation. Patients not eligible for bone marrow transplantation were eligible for randomization to two chemotherapy maintenance regimens. All patients undergoing bone marrow transplantation were conditioned with cyclophosphamide and total-body irradiation (TBI). Methotrexate was used to prevent or modify graft-versus-host disease (GVHD). RESULTS: Three hundred eighty-one patients achieved bone marrow remission (78%). Eighty-nine patients had an HLA/MLC-compatible sibling donor and were eligible for bone marrow transplantation, and 252 had no match. Comparison of survival estimates for patients eligible for transplantation versus not eligible at 3 years (52% v 41%), 5 years (50% v 36%), and 8 years (47% v 34%) showed a significant difference in favor of bone marrow transplantation (P < .05). Disease-free survival (DFS) demonstrated similar results. Application of a cure model to the results showed a better outcome for those eligible for transplantation (P = .04). Patients randomized between the two chemotherapy regimens did not show any significant difference between those treated with a continuous maintenance versus a cyclic regimen (P = .16). CONCLUSION: Children and young adults who successfully achieved a remission with multiple-agent chemotherapy who had an HLA/MLC-compatible donor and were thus eligible for an allogeneic bone marrow transplant had better survival than those not eligible for transplantation.

Acute Disease↗
PubMed1994

Treatment of newly diagnosed children and adolescents with acute myeloid leukemia: a Childrens Cancer Group study.

PURPOSE: The objectives of this study were to determine if the addition of etoposide, thioguanine, and dexamethasone to daunorubicin and cytarabine (five-drug regimen) during induction would improve remission induction rates and survival of children with acute myeloid leukemia (AML) when compared with the standard regimen of cytarabine and daunorubicin (7 + 3) and whether allogeneic bone marrow transplantation (BMT) or intensive chemotherapy consolidation with or without maintenance would give a superior outcome. PATIENTS AND METHODS: A total of 591 assessable children with AML entered Childrens Cancer Group (CCG) trial 213 between January 1986 and February 1989. The status of patients as of September 1, 1992 forms the basis of this report. The results were compared with previous AML studies. RESULTS: The projected survival rate of all patients at 5 years is 39% (event-free survival [EFS] rate, 31%), which is superior to that of the prior CCG study (P = .01). The induction rate was 79% for 7 + 3 and 76% for the five-drug regimen (not significant). Comparisons of BMT to chemotherapy favored BMT, but these differences do not always reach statistical significance (eg, 5-year disease-free survival [DFS] rate, 46% v 38% [P = .06] with donor available and 54% v 37% [P = .002] if treated according to protocol intent). No benefit for maintenance therapy was found and, in some comparisons, it was inferior to discontinuation of therapy (5-year survival rate, 46% v 68%, P < .01). CONCLUSION: The 5-year EFS rate of patients with AML is 31% and has improved. The five-drug induction regimen is no better than standard induction, BMT appears superior to chemotherapy, and maintenance therapy was not beneficial.

Adolescent↗
PubMed1994

Epidemiological characteristics of childhood acute lymphocytic leukemia. Analysis by immunophenotype. The Childrens Cancer Group.

While a number of epidemiological studies of childhood acute lymphocytic leukemia (ALL) have been conducted, separate analysis of risk factors for ALL subtypes has generally not been possible. We report the results of an analysis of data obtained from parents of children with ALL (and a control group of children without cancer), linked to a clinical database. Cases were classified into four ALL subtypes, and odds ratios (OR) were determined for each subtype for a broad range of factors. Numerous significant associations were found, some across all subtypes and others that were subtype-specific. Factors with elevated and/or significant ORs included: (i) for common ALL (n = 286): Down syndrome; family history (FH) of bone/joint diseases; postnatal jaundice; birthweight; MMR vaccination; exposure to gases and insecticides; and parental occupational exposure to insecticides. (ii) for pre-B ALL (n = 38): FH of gastrointestinal, hematological or bone/joint diseases, or allergy; cat ownership; exposure to solvents, fumes, petroleum products, cleaning agents and farm animals; and parental exposure to farm animals, fumes and solvents; (iii) for T-cell ALL (n = 158): FH of gastrointestinal disorders, maternal age, male gender, and parental occupational exposure to metals; (iv) for null-cell ALL (n = 65): FH of congenital heart disorders; measles; and parental occupational exposure to fumes, metals or solvents. This analysis should be considered as a hypothesis-generating process for future case-control interview studies.

Adolescent↗
PubMed1993

Relation between maternal diet and subsequent primitive neuroectodermal brain tumors in young children.

BACKGROUND: It has been hypothesized that a high dietary intake of nitrosamines and their precursors, nitrites and nitrates, is a risk factor for brain tumors. Vitamins C and E inhibit the formation of nitrosamines and thus may be protective. METHODS: We conducted a case-control study of maternal diet and the risk of primitive neuroectodermal tumors of the brain in children. The case patients were under the age of six years at diagnosis in 1986 to 1989. The controls were selected by random-digit telephone dialing and were matched for age and race to 166 case patients. Telephone interviews with the mothers included questions on the frequency of consumption of alcohol, vitamin and mineral supplements, and 53 foods during pregnancy. RESULTS: Significant protective trends were observed for vegetables (odds ratio for the highest quartile group for intake relative to the lowest, 0.37; P for trend = 0.005), fruits and fruit juices (odds ratio, 0.28; P = 0.003), vitamin A (odds ratio, 0.59; P = 0.03), vitamin C (odds ratio, 0.42; P = 0.009), nitrate (odds ratio, 0.44; P = 0.002), and folate (odds ratio, 0.38; P = 0.005). A nonsignificant trend of increasing risk was observed for nitrosamine (odds ratio, 1.65; P = 0.15). The use of iron (odds ratio, 0.43; P = 0.004), calcium (odds ratio, 0.42; P = 0.05), and vitamin C (odds ratio, 0.35; P = 0.04) supplements at any time during the pregnancy and the use of multivitamins during the first six weeks (odds ratio, 0.56; P = 0.02) were associated with decreased risk. In multivariate analyses, folate, early multivitamin use, and iron supplements generally remained protective. CONCLUSIONS: These results do not support the hypothesis that nitrosamines have a role in the development of primitive neuroectodermal tumors in young children, but they do suggest that certain other aspects of maternal diet can influence the risk.

Astrocytoma↗
PubMed1993

Purity of factor VIII concentrates and serial CD4 counts. The Transfusion Safety Study Group.

Whether expensive high-purity factor VIII concentrates are required to slow CD4 decline in HIV-infected haemophiliacs is controversial. We examined CD4 counts among such cases treated with intermediate-purity and high-purity factor VIII. 36 subjects treated with high-purity concentrate for 6 months or more had a smaller decline in CD4 than 72 matched controls on intermediate-purity concentrate (two-sided p = 0.08). In a more complex analysis with 226 subjects, CD4 counts declined 3% less per 6 months with high-purity material than with intermediate product (p = 0.04). Thus concentrate purity may affect rate of CD4 change.

CD4-Positive T-Lymphocytes↗
PubMed1993

Young adults 16-21 years of age at diagnosis entered on Childrens Cancer Group acute lymphoblastic leukemia and acute myeloblastic leukemia protocols. Results of treatment.

BACKGROUND: Scant data are available on event-free survival (EFS) for young adults with leukemia who were 16-21 years of age at diagnosis. In acute lymphoblastic leukemia (ALL), it is well recognized that children have a better EFS compared with adults, whereas for acute myelocytic leukemia (AML), EFS results seem to be similar. To determine the appropriate treatment for young adults with leukemia, outcome data are essential. METHODS: Young adults entered on the Childrens Cancer Group (CCG) 100 series ALL protocols and the CCG 213 AML protocol were analyzed for EFS and survival. Prognostic factors for EFS also were determined. RESULTS: The actuarial EFS for 143 young adults with ALL treated on the CCG 100 series ALL protocols was 64 +/- 4% at 4 years and 59 +/- 4% at 6 years. The major adverse prognostic feature was leukocyte counts greater than 50,000/microliters. The actuarial EFS for 79 young adults with AML entered on CCG 213 was 32.2 +/- 5.3% at 2 years and 28.6 +/- 5.3% at 3 years. CONCLUSIONS: Young adults with ALL treated on CCG protocols have a 6-year EFS of approximately 60%. This is similar to the EFS for patients 10-15+ years of age at diagnosis treated on the same protocols and better than EFS results reported from most adult trials. Young adults with AML had a slightly inferior outcome compared with younger children.

Adolescent↗
PubMed1993

Family history of cancer and seizures in young children with brain tumors: a report from the Childrens Cancer Group (United States and Canada).

The occurrence of cancer and neurological disorders in first- and second-degree relatives of children in the United States and Canada diagnosed with brain tumor before age six was investigated. A pair-matched case-control study with 155 astrocytoma and 166 primitive neuroectodermal tumor (PNET) cases was performed. Cases were identified through the Childrens Cancer Group. Controls were selected by random-digit dialing and matched to cases on age, race, and telephone area code and exchange. Childhood cancers were more common in PNET relatives compared with the general population (standardized incidence ratio [SIR] = 2.5, 95 percent confidence interval [CI] 1.1-4.8, P = 0.02) and with control relatives (odds ratio [OR] = 3.0, CI = 0.5-30, P = 0.29). For astrocytoma, nonsignificant excesses of brain tumor, leukemia/lymphoma, and childhood cancer occurred among case relatives compared with control relatives, but not compared with the general population. Astrocytoma cases were significantly more likely than controls to have a relative with seizures (OR = 2.5, CI = 1.2-4.9, P = 0.009), especially childhood seizures (OR = 3.4, CI = 1.2-12, P = 0.02), epilepsy (OR = 3.0, CI = 0.9-13, P = 0.08), and febrile convulsions (OR = 4.5, CI = 0.9-43, P = 0.07). A family history of stroke was not a risk factor for either type of brain tumor. These results suggest that some childhood brain tumors may result from a genetic susceptibility and that some risk factors may affect childhood astrocytoma and PNET differently.

Adult↗
PubMed1993

Lactate disposal in resting trained and untrained forearm skeletal muscle during high intensity leg exercise.

At a given oxygen uptake (VO2) and exercise intensity blood lactate concentrations are lower following endurance training. While decreased production of lactate by trained skeletal muscle is the commonly accepted cause, the contribution from increased lactate removal, comprising both uptake and metabolic disposal, has been less frequently examined. In the present study the role of resting skeletal muscle in the removal of an arterial lactate load (approximately 11 mmol.l-1) generated during high intensity supine leg exercise (20 min at approximately 83% maximal oxygen uptake) was compared in the untrained (UT) and trained (T) forearms of five male squash players. Forearm blood flow and the venoarterial lactate concentration gradient were measured and a modified form of the Fick equation used to determine the relative contributions to lactate removal of passive uptake and metabolic disposal. Significant lactate uptake and disposal were observed in both forearms without any change in forearm VO2. Neither the quantity of lactate taken up [UT, 344.2 (SEM 118.8) mumol.100 ml-1; T, 330.3 (SEM 85.3) mumol.100 ml-1] nor the quantity disposed of [UT, 284.0 (SEM 123.3) mumol.100 ml-1, approximately 83% of lactate uptake; T, 300.8 (SEM 77.7) mumol.100 ml-1, approximately 91% of lactate uptake] differed between the two forearms. It is concluded that while significant lactate disposal occurs in resting skeletal muscle during high intensity exercise the lower blood lactate concentrations following endurance training are unlikely to result from an increase in lactate removal by resting trained skeletal muscle.

Adult↗
PubMed1993

Impact of high-dose cytarabine and asparaginase intensification on childhood acute myeloid leukemia: a report from the Childrens Cancer Group.

PURPOSE: The purpose of this review was to determine the impact of high-dose cytarabine and asparaginase intensification, administered shortly after remission induction, on the outcome of childhood acute myeloid leukemia (AML). MATERIALS AND METHODS: Three consecutive Childrens Cancer Group (CCG) trials of acute myeloid leukemia, CCG 251 (1979 to 1983), CCG 213P (1983 to 1985), and CCG 213 (1985 to 1989) with a total of 1,294 patients, were reviewed and provide the basis of this report. RESULTS: CCG 213P demonstrated the importance of dose interval, in that two courses of cytarabine and asparaginase administered at 7-day intervals gave superior 5-year survival rates (58% v 41% from the end of induction, P < .04) to the same therapy administered at 28-day intervals. CCG 213 showed that there was no advantage to the maintenance therapy used for patients who received two courses of cytarabine and asparaginase at 7-day intervals (5-year survival, 68% [no maintenance] v 44% [maintenance] from the end of consolidation, P < .01). Inclusion of the 7-day interval cytarabine/asparaginase intensification was accompanied by an overall improvement in 5-year survival rates from diagnosis when compared with historical controls (CCG 213, 36% v CCG 251, 29%, P < .02) although other differences between these studies could also be responsible for the improvement seen. CONCLUSION: High-dose cytarabine and asparaginase intensification eliminated the benefit of prolonged maintenance therapy in childhood AML and was accompanied by an overall improvement in survival.

Acute Disease↗
PubMed1993

Outcome of BMT during first complete remission of AML: a comparison of two sequential studies by the Children's Cancer Group.

One hundred and fifty children with AML in first remission were treated with allogeneic BMT in two sequential studies of the Childrens Cancer Group. The absence of differences in baseline variables justified comparison between the two studies. In the initial study (CCG-251), patients received GVDH prophylaxis with MTX alone (17 doses over 102 days). In an attempt to diminish the morbidity and mortality of acute GVDH, a second study (CCG-213) employed stronger GVHD prophylaxis with 6 months of CYA and short-course MTX (four doses over 11 days). Outcome was compared between these two non-randomized populations of children with AML transplanted in first remission. Augmented GVHD prophylaxis substantially diminished treatment-related mortality from 31% to 11% (p = 0.0033), but this effect was counterbalanced by an increase in the relapse risk from 22% to 35% (p = 0.29). Event-free survival at 2 years was 54% on CCG-251 and 59% on CCG-213 (p = 0.21). We observed a marginal diminution of relapse risk among patients with chronic GVHD compared with those without chronic GVHD (19% vs. 35%, respectively; p = 0.10). No anti-leukemic effect of acute GVHD was observed.

Adult↗
PubMed1992

Expression of lymphoid-associated cell surface antigens by childhood acute myeloid leukemia cells lacks prognostic significance.

The prognostic significance of cell surface antigens associated with lymphoid and myeloid lineage differentiation on the blasts of children with acute myeloid leukemia (AML) was evaluated. Leukemic blasts from 176 patients enrolled on Childrens Cancer Study Group Protocol 213 determined to have AML by standard morphologic and cytochemical criteria were immunophenotyped. Cell surface antigens associated with myeloid differentiation were found on blasts from 88.1% of patients (CD15, 44%; CD33, 65%; CD36, 53%; glycoprotein Ib, 9.3%). However, blasts from 30.7% of patients expressed surface antigens thought to be specific for lymphoid lineage differentiation (CD2, 9.4%; CD5, 2.7%; CD19, 34.5%; CD20, 0.8%). In addition, CD34, a glycoprotein found on immature cells of both myeloid and lymphoid lineages, was expressed on the blast cells of 48.2% of patients. With the exception of the lymphoid lineage nonspecific antigen CD4, no correlation was found between white blood cell count at diagnosis, age, and French-American-British morphology, and the expression of any of the lymphoid- or myeloid-associated cell surface antigens studied. Nor was the expression of these antigens prognostically significant with respect to response to induction therapy, death during induction, survival, event-free survival, or survival/event-free survival following remission induction. Multivariate analysis showed that CD4 expression was not an independent predictor of outcome. Thus, this prospective study suggests that expression of lymphoid-associated cell surface antigens as well as myeloid-associated antigens by childhood AML blasts lacks prognostic significance.

Adolescent↗
PubMed1992

Expression of myeloid differentiation antigens in acute nonlymphocytic leukemia: increased concentration of CD33 antigen predicts poor outcome--a report from the Childrens Cancer Study Group.

Ninety-eight cryopreserved specimens of acute nonlymphocytic leukemia (ANLL) cells obtained at initial diagnosis of children enrolled on the Childrens Cancer Study Group 251 protocol (CCG 251) were examined by indirect immunofluorescence using four monoclonal antibodies to myeloid differentiation antigens. The relationship between the level of differentiation of ANLL cells as determined by their antigen phenotype and the clinical outcome of treatment, including complete remission (CR) rate, survival, and event-free survival, was evaluated. Most leukemic specimens were determined to express the CD33 antigen (L4F3), a 67-kD protein. Because the level of differentiation of normal myeloid cells is reflected by the concentration of the CD33 antigen expressed, samples were categorized as CD33-bright (immature) versus CD33-dull (mature). Patients with CD33-bright leukemic blasts had a marginally inferior CR rate to those with CD33-dull blasts (P = 0.08). With respect to survival and event-free survival, there was a significantly inferior outcome in the CD33-bright patients (P = 0.04 and P = 0.06, respectively). Reactions of ANLL with anti-CD15 antibody (1G10), anti-CD36 antibody (5F1), or anti-CD17 antibody (T5A7) did not predict clinical outcome. This study indicates that patients whose ANLL blasts displayed the CD33 antigen in an amount associated with immature myeloid cells experienced a worse outcome than patients with ANLL blasts that expressed a phenotype associated with more mature cells.

Antibodies, Monoclonal↗
PubMed1992

The CCSG prospective study of venous access devices: an analysis of insertions and causes for removal.

This is an interval analysis of the 2-year prospective multicenter Childrens Cancer Study Group study of 1,141 chronic venous access devices in 1,019 children with cancer. Device type was external catheter (EC) 72%, totally implantable (TID) 28%, and did not differ for diagnosis or age except more double-lumen devices in bone marrow transplant protocols (77%) and more TIDs in children less than 1 year old (17.7%). Insertion characteristics evaluated in 1,078 (95%) were: operating room placement 99%; general anesthesia 98%; cutdown 67%; percutaneous 33%; atrial position 50%, caval position 50%; and perioperative antibiotics 48%. Vein entry was the external jugular 33%, internal jugular 22%, subclavian 35%, cephalic 7%, and saphenous 3%. Insertion was difficult or very difficult in only 10% and operative complications occurred in only 0.7%. Degree of difficulty bore no relationship to device type or patient age. The reasons for removal in 736 devices (67%) were due to complications in 39%, of which infections were the most frequent. There was some variance between centers ranging from 8.5% to 31% for infection; 2.8% to 24% for dislodgment; and 0% to 13% for occlusion. ECs had a higher risk of dislodgment; elective removals were more frequent in TIDs; there was no difference in infection as a cause for removal between ECs and TIDs. Dislodgment was associated with the shortest distance of the cuff to the skin exit (mean, 4 cm): less than or equal to 2 cm, 49%; greater than 2 cm, 28% (P = .009) and occurred most frequently in the younger patient (18.9%, 0 to 1 years; 0.5%, greater than 8 years.

Adolescent↗
PubMed1992

The aetiology of cancer in the very young.

Epidemiological studies of cancer in young children have implicated a number of environmental factors, which need to be studied in more detail, but it is probably fair to say that the main benefit of these studies has come from the negative findings, which have served to exclude (or at least place an upper limit on the role of) potential risk factors. Our inability to identify environmental causes could mean either that the environment does not substantially affect cancer incidence in young children, or that we are simply not looking in the right places. Most attention has naturally been focused on the known and suspected environmental carcinogens and mutagens. Based on the data summarised in this paper, one possibility is that the most important mutagen is endogenous: 5-methyl-cytosine. If so, factors increasing cancer risk could be those which increase the rate of spontaneous deamination, or impair the efficiency of the excision repair enzymes, or regulate the processes of CpG methylation and demethylation. These factors could still be classed as mutagens in their own right, since they would lead to an increase in uncorrected point mutations, but they would be distinctive in a number of ways. Firstly, since the role of methylation in bacteria is very different from that in eukaryotic cells the Ames mutagenicity assay could not be relied upon to detect methylation-mediated mutagens. Furthermore the risk may be highly age dependent, reflecting changes in methylation patterns with growth and cellular differentiation. Agents which disrupted the imprinting process in the testis would not be detectable by animal carcinogenicity tests unless specifically looked for.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1991

From gene to carcinogen: a rapidly evolving field in molecular epidemiology.

Chemical and physical carcinogens leave footprints of their activities on DNA because of the patterns of base changes they induce. Additionally, the conversion of 5-methylcytosine to thymine in CpG sequences leads to a characteristic mutation which can be used to estimate the contribution of endogenous processes to human mutations. Knowledge of the pattern mutations found in genes commonly mutated in human cancer, such as the p53 tumor suppressor gene, allows for predictions to be made on the likelihood of an exogenous DNA-damaging agent being involved. Working from gene to carcinogen is likely to have a profound impact on our understanding of the origins of human cancer.

Carcinogens↗
PubMed1991

Successful reinduction therapy with amsacrine and cyclocytidine in acute nonlymphoblastic leukemia in children. A report from the Childrens Cancer Study Group.

Amsacrine (AMSA) and cyclocytidine were studied as retrieval therapy in 122 pediatric patients with acute nonlymphoblastic leukemia (ANLL). Patients either failed to achieve sustained initial remissions or were in relapse. Induction therapy consisted of intravenous (IV) AMSA (75 mg/m2) from days 1 to 5 and subcutaneous cyclocytidine (600 mg/m2) from days 1 to 7. Maintenance therapy consisted of IV etoposide (VP-16) (100 mg/m2) for 5 days and IV AMSA (100 mg/m2) on day 1. Of 122 patients, 109 were evaluable. There were 13 early deaths. Ninety-six patients received adequate therapy defined as completion of two courses of therapy. Of these 96 patients, 52 achieved complete remission. Fifteen of 33 patients who failed initial induction achieved complete remission. Eighteen of 39 patients who were resistant to anthracyclines had complete responses. There was no direct evidence of AMSA-induced cardiotoxicity. Remission duration was 28 days to 3 or more years (median, 98 days). AMSA and cyclocytidine were effective retrieval therapy for patients who were in relapse or unresponsive to frontline therapy. Duration of remission was short (median, 98 days).

Adolescent↗