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Biomedical subjects

C H Pui

Publications and source records attributed to C H Pui.

At least 307 records · Page 17Linked to original sources
PubMed1986

Urolithiasis in childhood acute leukemia and nonHodgkin's lymphoma.

Ureteral calculi were found in 5 children who were receiving or had recently completed remission induction therapy for acute leukemia or lymphoma. All 5 patients had abdominal or back pain and 3 had gross hematuria. The diagnosis of urolithiasis was suggested by excretory urograms that showed obstructive uropathy (4 patients) and by computerized tomography scans that demonstrated ureterovesical obstruction (1 patient with acute renal failure and anuria). With a single exception the calculi were not associated with urinary tract infections. Chemical analyses in the 2 patients tested indicated that the stones were composed of calcium, in contrast to the uric acid and xanthine compositions of stones in earlier studies of patients with leukemia or lymphoma. Factors that might have predisposed our patients to calculi formation include corticosteroid therapy, immobilization owing to bed rest and urinary alkalization. Other possible contributing factors were urinary stasis (2 patients) and a familial tendency for renal calculi to develop. There was no evidence of idiopathic hypercalciuria in either patient tested. Prompt detection of urolithiasis in children undergoing induction chemotherapy for a malignant disease may avoid potentially serious consequences from urinary tract obstruction.

Adolescent↗
PubMed1986

Use of the automatic interaction detector method to identify patient characteristics related to methotrexate clearance.

Systemic methotrexate (MTX) clearance was determined in 108 children who received 15 courses of MTX, 1000 mg/m2 iv over 24 hours, as a component of therapy for acute lymphocytic leukemia. The median MTX clearance was used as the representative value for each patient, and these values ranged from 44.7 to 132.1 ml/min/m2 (X = 78.4 ml/min/m2). The automatic interaction detector approach was used to determine the patient characteristics that correlated with MTX clearance. Characteristics examined were sex, age, estimated creatinine clearance, SGPT, and body surface area. The initial splits were based on creatinine clearance, and mean MTX clearances in three subgroups (50 to 100, 100 to 150, and greater than 150 ml/min/m2) were 73.1, 78.3, and 90.5 ml/min/m2, respectively. For patients with the slowest creatinine clearance, abnormal SGPT concentrations (greater than 35 IU/L) were associated with slower MTX clearance (77.6 vs. 67.8 ml/min/m2). In the latter subgroup, boys had faster clearance than girls (77.4 vs. 60.9 ml/min/m2). These results demonstrate that for children with normal serum creatinine concentrations, interpatient variability in MTX clearance can partly be explained by measures of renal and hepatic function, which indicates that the observed variability in MTX clearance is not totally random.

Adolescent↗
PubMed1986

Lack of pathogenetic role of proteins C and S in thrombosis associated with asparaginase-prednisone-vincristine therapy for leukaemia.

Plasma levels of protein C and protein S antigens were measured in eight children who developed thrombosis following asparaginase-prednisone-vincristine treatment for acute lymphoblastic leukaemia and in nine similarly treated children without this complication. Protein C antigen levels were below normal in three of the eight patients with thrombosis and in three of the nine patients without the complication (P = 0.38). Low protein S antigen levels were found in five of six patients with thrombosis and in two of seven patients without thrombosis (P = 0.10). Plasma factor IX and factor X antigen levels, other vitamin K dependent factors, were also measured in the two groups of patients. In general, reduced levels of protein C, protein S or both antigens (anticoagulant vitamin K dependent proteins) were associated with reduced levels of factor IX, factor X, or both of these factors (procoagulant vitamin K dependent clotting proteins). The ratios of protein C and protein S antigens to each other and to factor IX and factor X antigens did not differ between the two groups. Thus, there is no clear evidence that reduced levels of protein C and (or) protein S cause thrombosis in leukaemia patients treated with this drug combination.

Adolescent↗
PubMed1986

Results of treatment of advanced-stage Burkitt's lymphoma and B cell (SIg+) acute lymphoblastic leukemia with high-dose fractionated cyclophosphamide and coordinated high-dose methotrexate and cytarabine.

To address the problem of historically poor results in the treatment of children with advanced-stage Burkitt's lymphoma and B cell (SIg+) acute lymphoblastic leukemia (ALL), an intensive chemotherapy regimen was devised using the most effective single agents in high-dose short courses. Treatment commenced with a fractionated schedule of intravenous (IV) cyclophosphamide (300 mg/m2 every 12 hours for six doses) followed immediately by Adriamycin (50 mg/m2) and vincristine (1.5 mg/m2) with combined intrathecal (IT) methotrexate and cytarabine. Predictably, this treatment produced virtually complete disappearance of all tumor and profound myelosuppression. Immediately on hematologic recovery, IV high-dose methotrexate (1,000 mg/m2 over 24 hours) followed by IV cytarabine (400 mg/m2 over the next 48 hours) was administered with leucovorin rescue and repeated IT treatments. The treatment sequence described above is repeated four times, with the dose of cytarabine doubled in succeeding courses, up to 3,200 mg/m2. The entire planned therapy required approximately 24 weeks. Since 1981, we treated a total of 29 children with this approach, 19 of whom had massive unresectable intraabdominal tumor. According to initial extent of disease, 17 were classified as stage III, four as stage IV non-Hodgkin's lymphoma (NHL), and eight as B cell ALL. Eight of the 12 patients with stage IV NHL or B cell ALL had initial involvement of the CNS. Twenty-seven of 29 patients (93%) attained a complete remission. Fourteen of 17 stage III NHL patients remain disease free, for periods ranging from 3+ months to 4 1/2+ years. The actuarial estimate of the proportion of stage III patients remaining disease free at 2 years is 81%. Results in patients with initial involvement of the CNS and/or marrow are much less favorable, with only two of ten patients who attained remission apparently being cured. In addition to stage, the initial serum lactic dehydrogenase (LDH) level emerged as a prognostic indicator, higher levels (over 1,000 IU/L) being associated with the worst prognosis (P less than .05). Major toxicity consisted of severe hematopoietic suppression and febrile episodes associated with neutropenia. We conclude that this treatment is highly effective for advanced-stage Burkitt's tumors in children free of initial CNS involvement.

Actuarial Analysis↗
PubMed1986

The clinical and biological correlates of coagulopathy in children with acute leukemia.

We determined the clinical and biological correlates of coagulopathy in a large series of patients with untreated childhood acute leukemia. Twenty-five of 805 children with acute lymphoblastic leukemia (ALL) (3.1%) and 27 of 195 with acute myeloid leukemia (AML) (13.8%) met any two of three requirements for a coagulation disorder: fibrinogen level less than 150 mg/dL; fibrin degradation products greater than 10 micrograms/mL; and prolongation of prothrombin time (PT) greater than 12 seconds, activated partial thromboplastin time (PTT) greater than 45 seconds, or thrombin time (TT) greater than 18 seconds. Patients with ALL complicated by abnormal coagulation were more likely to be boys and to have a T-cell immunophenotype, a high leukocyte count, a mediastinal mass, leukemic involvement of the CNS, hepatosplenomegaly, and L2 blast cell morphology. These features were highly interrelated, with only T-cell markers and CNS involvement achieving independent significance in a multivariate logistic regression model. Hepatomegaly, blast cell morphological subtype (French-American-British [FAB] M3, M4, and M5) and age less than 2 years were each associated with coagulopathy in patients with AML, although age failed to retain importance after logistic regression analysis. The presence of coagulopathy at diagnosis of ALL did not influence the rate of remission induction (P = .55). By contrast, only 14 of 27 children with coagulopathy at diagnosis of AML achieved a complete remission (CR), compared with 129 of 168 other patients who lacked this complication (P = .003). After multivariate analysis, coagulopathy remained independently associated with failure to attain remission in AML (P = .02). Fatal hemorrhagic complications arising in the CNS or lungs accounted for nine of the 13 induction failures in this group. The presence or absence of coagulopathy had no discernible influence on treatment outcome among patients with either ALL or AML who attained a CR. Laboratory evidence of a coagulation defect may be useful in identifying patients with AML who have a greater risk of induction failure and, hence, require close surveillance and intensive replacement therapy to prevent fatal hemorrhagic complications.

Blood Coagulation Disorders↗
PubMed1986

Cytogenetic features and serum lactic dehydrogenase level predict a poor treatment outcome for children with pre-B-cell leukemia.

Leukemic cells from 89 (24%) of 369 children with newly diagnosed acute lymphoblastic leukemia (ALL) were found to have a pre-B immunophenotype. By comparison with blasts having the common ALL phenotype, the pre-B cells were more likely to have a DNA index less than 1.16 (P = 0.02), a pseudodiploid karyotype (P less than 0.001), and a chromosomal translocation (P = 0.001). Increased serum lactic dehydrogenase levels (P = 0.001) were also characteristic of pre-B ALL; otherwise, the clinical and laboratory features of the two groups were similar. A nonrandom chromosomal translocation, t(1;19)(q23;p13.3), was identified in blast cells from 16 (23%) of the 70 patients with pre-B ALL and adequate chromosome banding studies; different translocations were found in 11 of the remaining patients. The presence of any chromosomal translocation in the pre-B group was significantly related to a higher leukocyte count, an increased level of serum lactic dehydrogenase, an increased percentage of S-phase cells, black race, and a blast cell DNA index less than 1.16. Four presenting features were found to confer an increased risk of treatment failure among pre-B patients: pseudodiploidy, chromosomal translocation, black race, and higher serum lactic dehydrogenase level. In a multivariate analysis, pseudodiploidy emerged as the strongest factor for predicting relapse in pre-B ALL. The frequent association of chromosomal abnormalities of known adverse prognostic significance and high serum lactic dehydrogenase levels with pre-B-cell ALL explains, at least in part, the poor treatment outcome reported for children with this subtype of leukemia.

Adolescent↗
PubMed1986

Shifts in blast cell phenotype and karyotype at relapse of childhood lymphoblastic leukemia.

Analyses of bone marrow blast cells collected at diagnosis and relapse from 68 children with acute lymphoblastic leukemia (ALL) demonstrated changes in the expression of cell markers in one-fourth of the patients. Loss of the common ALL antigen (CALLA) was a frequent change, occurring in 8 of the 51 cases initially classified as common or pre-B ALL. The HLA-DR antigen was either acquired or lost in 5 of the 68 cases, terminal deoxynucleotidyl transferase was lost in 6 of 25 cases, and reactivity of the T10 antigen with monoclonal antibodies was increased in 6 of 17 cases of non-T cell ALL. Conversion to acute nonlymphoblastic leukemia, so-called lineage switch, was noted in two cases of common ALL and one of pre-B ALL, coinciding with the loss of CALLA. Results of chromosomal analyses in cases with a loss of CALLA implicated several mechanisms in the observed phenotypic changes. In six cases, including each instance of lineage switch, the original karyotype had been replaced by an entirely different abnormal karyotype, suggesting clonal selection or induction of a second malignancy. In another case, the evidence suggested clonal evolution. Our findings demonstrate that sequential phenotypic and cytogenetic studies may yield valuable insights into the mechanisms of leukemic recurrence and may have implications for treatment selection.

Adolescent↗
PubMed1985

Bone marrow necrosis in children with malignant disease.

The authors reviewed the case records of 1419 children with acute leukemia and other types of malignant disease involving the bone marrow to define the clinical and laboratory features associated with marrow necrosis as well as the prognostic significance of this complication. Only seven patients were found to have this abnormality: four with newly diagnosed acute lymphoblastic leukemia (ALL), one with relapsed ALL, and two with disseminated neuroblastoma. All patients presented with severe bone pain, bone tenderness, and fever. Levels of serum lactic dehydrogenase were uniformly increased, being especially high in patients with ALL. There was no evidence of severe infection or disseminated intravascular coagulation, complications that have been causally related to marrow necrosis. Four of the five children with ALL remain in complete remission for 10+ to 48+ months. Both patients with neuroblastoma are off therapy, in remission, for 9+ to 15+ months. In contrast to earlier reports, bone marrow necrosis does not appear to confer a poor prognosis in children with malignancy.

Bone Marrow↗
PubMed1985

Elective testicular biopsy during chemotherapy for childhood leukaemia is of no clinical value.

The clinical value of early detection of testicular leukaemia was assessed by elective wedge biopsy during the 12th or 18th month of therapy in children with acute lymphoblastic leukaemia. Biopsy samples were taken in 106 of 238 consecutively treated boys who attained complete remission; only 1 had occult disease. Samples were also taken in 2 boys with testicular leukaemia at diagnosis as soon as they achieved complete remission, and in 14 others at the end of therapy; none showed evidence of leukaemic infiltration. 13 boys, including the 1 with biopsy-confirmed occult disease, had a testicular relapse; 6 of these patients had had negative biopsy findings 12-28 months before relapse. These results indicate that elective testicular biopsy during therapy for childhood leukaemia is of no benefit clinically. They also suggest that routine use of end-of-therapy testicular biopsy should be re-evaluated, since frequency of testicular relapse is low, therapy is effective, and negative biopsy findings do not preclude eventual relapse.

Adolescent↗
PubMed1985

Clinical and biologic correlates of insulin binding by leukemia lymphoblasts.

The percentage of total 125I-labeled insulin specifically bound to lymphoblasts was measured in 46 children with leukemia. Among 35 children with newly diagnosed acute lymphoblastic leukemia (ALL), specific insulin binding ranged from 0.09 to 14.8% per 10(6) blasts. A lower level of insulin binding was correlated with T-cell surface markers (P less than 0.003), higher hemoglobin level (P less than 0.005), presence of a mediastinal mass (P less than 0.01), lower glucocorticoid receptor level (P less than 0.02), higher platelet count (P less than 0.04), age less than 2 or greater than 10 yr (P less than 0.05), white blood cell count greater than or equal to 100 X 10(3)/mm3 (P less than 0.06) and higher labeling index (P less than 0.07). It was not correlated with the presence of central-nervous-system disease, FAB classification, or sex. With a follow-up of 24 to 33 + months, insulin binding was not correlated with treatment outcome. Six patients with relapsed ALL and three with acute nonlymphoblastic leukemia showed insulin binding levels similar to those in newly diagnosed ALL patients. Blasts from one patient with B-cell ALL and one with chronic myelogenous leukemia were characterized by lower insulin binding, while lymphoblasts from a patient with T-cell lymphoma bound insulin at marginally detectable levels. In vitro studies with IM-9, NALM-1 and NALM-16 cell lines showed that changes in insulin binding caused by dexamethasone treatment were not correlated with hormone-induced cell death. Although study of insulin binding by malignant lymphoid cells may be important in understanding the biology of leukemic cells, it does not appear to have any obvious clinical utility.

Adolescent↗
PubMed1985

Differing complications of hyperleukocytosis in children with acute lymphoblastic or acute nonlymphoblastic leukemia.

We assessed the frequency and outcome of complications associated with hyperleukocytosis in children who had received remission induction therapy for either acute lymphoblastic leukemia (ALL) or acute nonlymphoblastic leukemia (ANLL). Among 234 consecutive patients with a leukocyte count of 100 X 10(9)/L or greater at diagnosis, the frequency of early death was significantly higher in those with ANLL (23% v 5% for patients with ALL, P less than .001). The risk of early death increased with increasing leukocyte count, especially when it exceeded 300 X 10(9)/L in patients with ANLL (P less than .001). Intracerebral hemorrhage occurred in eight (11%) of the ANLL patients and accounted for six of the 17 early deaths; in all but two instances, the complication was associated with coagulopathy. Respiratory failure, presumably from pulmonary leukostasis, resulted in six other early deaths in ANLL patients. By contrast, intracerebral hemorrhage occurred in only two of the ALL patients (1.2%); both had normal coagulation studies, but leukocyte counts greater than 400 X 10(9)/L. Severe metabolic derangements from blast cell lysis accounted for three of the eight early deaths among patients with ALL. Leukapheresis or exchange transfusion effectively lowered the leukocyte counts of all 15 patients who received the procedures. Either method may be preferable to emergency cranial irradiation for preventing the complications of hyperleukocytosis in children with acute leukemia.

Acute Disease↗
PubMed1985

Unexpectedly severe toxicity from intensive early treatment of childhood lymphoblastic leukemia.

In early 1984, we treated 13 consecutive patients with acute lymphoblastic leukemia (ALL) using an induction regimen of rapidly rotated combinations of prednisone, vincristine, asparaginase, teniposide (VM-26), cytosine arabinoside, and high-dose methotrexate (MTX) followed by leucovorin rescue. The intent of this clinical trial, designated Total Therapy Study XI, is to test the hypothesis that greater initial leukemia cell kill will decrease opportunities for the development of drug-resistant mutants, with resultant improvement in the length of disease-free survival. Five patients experienced life-threatening gastrointestinal toxicity within three weeks of the start of treatment. One died. Three other patients had severe abdominal pain, abdominal distention, diarrhea, and weight loss, but not gastrointestinal bleeding. In the remaining five patients, toxicity was rapidly reversible, and each child was able to complete the planned course of chemotherapy. The study was then amended to switch high-dose MTX from the induction phase to the consolidation phase, allowing at least one week for mucosal recovery. Among the next 28 patients who were treated, none showed evidence of severe gastrointestinal toxicity. Patients now receive high-dose MTX alone as consolidation therapy and are tolerating it adequately. Drug timing should be examined critically when intensified multiple-agent regimens are being devised for initial treatment of ALL.

Adolescent↗
PubMed1985

Clinical relevance of lymphoblast biological features in children with acute lymphoblastic leukemia.

Improvements in therapy for childhood acute lymphoblastic leukemia (ALL) have led us to reevaluate the prognostic significance of lymphoblast characteristics at diagnosis. From application of univariate and multivariate statistical methods, we determined the relationship of five blast cell features to treatment outcome in 250 patients who were enrolled in two clinical trials at this center from May 1979 through April 1982. Karyotype ploidy, lymphoblast morphology, and immunophenotype were each significantly related to prognosis as measured by time to failure, while periodic acid-Schiff reactivity and glucocorticoid receptor number lacked prognostic implication for this patient population. In addition, clinical features of initial WBC count, age, and race were also significant independent variables in predicting treatment response. By multivariate analysis, both ploidy and morphology contributed prognostic information to a clinical model based on WBC count, age, and race. If the model was adjusted for impact of ploidy, however, French-American-British morphology no longer contributed additional prognostic information. Our findings suggest that many traditional biological features used to estimate prognosis in ALL can be discarded in favor of clinical features (leukocyte count, age, and race) and cytogenetics (ploidy) for planning of future clinical trials.

Adolescent↗