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Biomedical subjects

C H Pui

Publications and source records attributed to C H Pui.

337 records · Page 19Linked to original sources
PubMed1983

Sequential changes in platelet function and coagulation in leukemic children treated with L-asparaginase, prednisone, and vincristine.

Coagulation and platelet function in 13 children with acute lymphoblastic leukemia were studied sequentially during a remission induction with L-asparaginase, prednisone, and vincristine. In the first weeks of therapy, which included four doses of L-asparaginase coagulation was characterized by significant decreases in plasma concentrations of plasminogen, antithrombin III alpha 2-macroglobulin, and fibrinogen. All measures gradually returned to normal after complication of L-asparaginase therapy. In the latter part of induction treatment, clotting times, especially partial Thromboplastin time, decreased significantly, while levels of factors V and VIII increased with recovery of platelet counts. At this time, 6 patients had an increased in vitro platelet aggregation response to adenosine diphosphate, and their partial thromboplastin times were significantly shorter than those of patients without increased aggregation. Concurrent abnormalities in coagulation and platelet function may account for the thrombotic complications that develop in some children receiving induction therapy with these agents.

Acute Disease↗
PubMed1983

Normal platelet function after therapy for acute lymphocytic leukemia.

The aggregation responses of platelets from 19 patients who had completed treatment of acute lymphocytic leukemia (ALL) and had remained in remission for two months to 4.8 years were studied both in vitro and in vivo. Responses to 0.5 micro M adenosine diphosphate (ADP), epinephrine, and collagen were all normal. One child had irreversible platelet aggregation to 0.1 micro M ADP, a concentration that only elicited a primary aggregation response from control platelets. The mean platelet-aggregate ratio was normal. We conclude that platelet defects, although a possible late effect of ALL or its chemotherapy, do not occur with any appreciable frequency in long-term survivors.

Adolescent↗
PubMed1982

Acute megakaryoblastic leukaemia associated with intrinsic platelet dysfunction and constitution ring 21 chromosome in a young boy.

A 3-year-old boy with pancytopenia and a paucity of circulating blast cells was found to have acute megakaryoblastic leukaemia. Histopathologic investigation of the bone marrow biopsy disclosed replacement by megakaryoblasts and mild-to-moderate reticulin fibrosis, the megakaryocytic origin of these cells was confirmed by their staining properties and by cross-reactivity with rabbit anti-rat platelet serum. Treatment with adriamycin and cytosine arabinoside induced a complete remission of this otherwise rapidly fatal disease. Before chemotherapy, the patient's platelets showed decreased aggregation in response to thrombin and adenosine diphosphate, as well as a defective thrombin-induced serotonin release reaction. Neither functional defect resolved after remission induction, indicating that the platelets were intrinsically abnormal. Most striking was the finding of a constitution chromosomal defect, a ring No. 21 chromosome, in addition to an abnormal malignant stem line. This appears to be the first reported instance of a constitutional r(21) chromosome associated with acute leukaemia.

Bone Marrow↗
PubMed1982

Hereditary elliptocytosis: morphologic abnormalities during acute hepatitis.

A 10-year-old black girl with hereditary elliptocytosis had a transient increase in hemolysis and unusual red cell morphologic changes during an episode of acute hepatitis. Changes in membrane lipids of these elliptocytes with defective membrane skeletal protein and abnormal distribution of cholesterol may be responsible for this phenomenon.

Acute Disease↗
PubMed1981

Risk factors for hyperglycemia in children with leukemia receiving L-asparaginase and prednisone.

We determined retrospectively the frequency and risk of hyperglycemia in 421 children with leukemia who had received L-asparaginase and prednisone as part of their remission induction therapy. Forty-one patients (9.7%) developed this complication, 39 within one week after the first dose of L-asparaginase. Hyperglycemia resolved in all patients and in 32 before the end of the four-week induction period. Age, obesity, and Down syndrome each had a significant bearing on the frequency of hyperglycemia. Children 10 years of age or older were more likely to develop the complication than were younger children. When more than one factor was present in a child, the risk of hyperglycemia increased significantly. A family history of diabetes mellitus also appeared related to an increased risk of hyperglycemia. Childhood leukemia patients with any of the risk factors identified here should be closely monitored for glucosuria while receiving prednisone and L-asparaginase for remission induction.

Adolescent↗
PubMed1980

Evans syndrome in childhood.

The combination of idiopathic thrombocytopenic purpura and autoimmune hemolytic anemia is rare in childhood. Among 164 instances of ITP and 15 instances of AHA, 11 patients were found to have this combination. Three were found to have systemic lupus erythematosus, one had aplastic anemia, and seven had Evans syndrome. Neutropenia, at times associated with bacterial infections, occurred in four of the latter patients. Unlike most cases of ITP or AHA in childhood, the clinical course of Evans syndrome is usually chronic and relapsing. Treatment including corticosteroids, splenectomy, and immunosuppressive agents has been generally unsatisfactory. In view of the frequent presence of antibodies directed at red blood cells, platelets, neutrophils, and lymphocytes, immunopancytopenia may be a better term for this condition.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Bacillus cereus causing fulminant sepsis and hemolysis in two patients with acute leukemia.

PURPOSE: Hemolysis is so rarely associated with Bacillus cereus sepsis that only two very well documented cases have been reported. This article reports two unusual cases of Bacillus cereus sepsis with massive intravascular hemolysis in patients who had acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: A 20-year-old woman who was 9 weeks pregnant experienced a relapse of ALL. A therapeutic abortion was performed. During week 4 of reinduction the patient had abdominal pain, nausea, and vomiting, with severe neutropenia but no fever. Her condition deteriorated rapidly with cardiovascular collapse, acute massive intravascular hemolysis, and death within hours of the onset of symptoms. Blood cultures were positive for Bacillus cereus. Postmortem histologic examination and cultures revealed Bacillus cereus and Candida albicans in multiple organs. The second patient, a 10-year-old girl, presented with relapsed T-cell ALL. In the second week of reinduction, she had abdominal pain followed by hypotension. Again, no fever was noted. Laboratory studies showed intravascular hemolysis 12 hours after admission. Aggressive support was promptly initiated. Despite disseminated intravascular coagulation; cardiovascular, hepatic, and renal failure; and multiple intracerebral hypodense lesions believed to be infarcts, the patient recovered fully and resumed reinduction therapy. CONCLUSIONS: Bacillus cereus infection can have a fulminant clinical course that may be complicated by massive intravascular hemolysis. This pathogen should be suspected in immunosuppressed patients who experience gastrointestinal symptoms and should not be precluded by the absence of fever, especially if steroids such as dexamethasone are being given. Exchange transfusion may be lifesaving in Bacillus cereus septicemia associated with massive hemolysis.

Adult↗
PubMedDate not supplied

Parvovirus B19 infection in a child with acute lymphoblastic leukemia during induction therapy.

Immunocompromised children, including those undergoing chemotherapy treatment of malignant disease, are at particular risk for infection with parvovirus B19. However, these patients' attenuated immune responses may obscure the serologic and clinical manifestations of the infection. The authors describe a patient undergoing induction therapy for acute lymphoblastic leukemia whose parvovirus B19 infection was identified by the incidental detection of giant pronormoblasts and absence of normal mature erythroid precursors, characteristic of parvovirus infection, on a routine bone marrow examination. Intravenous immunoglobulin was administered and the patient's aplastic anemia resolved completely within 3 weeks. This highlights the importance of alertness to the possibility of parvovirus infection in children with cancer.

Anemia, Aplastic↗
PubMedDate not supplied

Genetic studies in acute lymphoblastic leukemia.

As the long-term event-free survival rate in children with acute lymphoblastic leukemia approaches 80%, emphasis is being placed on risk-directed therapy to prevent over- or undertreatment. It has become apparent that risk assignment based on primary genetic abnormalities is inadequate by itself, and that measurement of early responses to therapy and the extent of minimal residual disease is needed to improve the accuracy of risk classification. Studies to identify genetic polymorphisms with pharmacokinetic and pharmacodynamic significance promise to enhance the discovery of new drugs and to optimize chemotherapy. Recent successes in directing therapy to specific genetic abnormalities demonstrate the feasibility of molecular medicine for the childhood leukemias, and predict the development of highly effective drug regimens with minimal toxicity against normal hematopoietic cells.

Child↗
PubMedDate not supplied

Renal function and methotrexate clearance in children with newly diagnosed leukemia.

STUDY OBJECTIVES: To determine whether glomerular filtration rate (GFR) changes during induction chemotherapy in children with leukemia, and to examine GFR as a determinant of pharmacokinetic variability of methotrexate clearance. DESIGN: Prospective, unblinded observational study in consecutive patients. SETTING: A research hospital. PATIENTS: Thirty-eight children newly diagnosed with acute lymphoblastic leukemia. INTERVENTIONS: The patients received either high-dose methotrexate 1 g/m2 intravenously over 24 hours or low-dose methotrexate 30 mg/m2 orally every 6 hours for six doses; both regimens were followed by an intensive six-drug chemotherapy regimen given over 6 weeks. Glomerular filtration rate was determined in each subject before and at the conclusion of induction therapy. MEASUREMENTS AND MAIN RESULTS: The GFR was determined from 99mTc-DTPA serum clearance in all patients, and methotrexate clearance was estimated from serial serum concentrations in 18 of these children who received high-dose methotrexate. Median values for GFR at diagnosis (131 ml/min/1.73 m2) and after induction therapy (120 ml/min/1.73 m2) were not significantly different (p = 0.26) but were highly variable (range 49-274 ml/min/1.73 m2). Body size, age, and serum creatinine were correlated significantly with GFR at diagnosis. Amphotericin B therapy (6 patients) significantly decreased GFR (p = 0.046) without a corresponding increase in serum creatinine. Methotrexate clearance (58-155 ml/min/m2) was significantly (p = 0.007) correlated with GFR, but GFR accounted for only 37% of the variability of methotrexate clearance. CONCLUSIONS: The GFR was normal but highly variable in these children with leukemia and was significantly altered by amphotericin. Our results explain little of the intersubject variability in methotrexate clearance.

Administration, Oral↗
PubMedDate not supplied

Childhood leukemias--current status and future perspective.

Current chemotherapy will cure at least 65% of children with acute lymphoblastic leukemia (ALL). The major challenge in ALL is to develop effective risk-directed therapy. This approach seeks to improve outcome, through more intensive therapy, for children at high risk of relapse, while reducing the side effects and long-term complications of treatment for those with a high likelihood of cure. The prognosis remains poor for most children with acute myeloid leukemia (AML). Despite the use of intensive chemotherapy and bone marrow transplantation, only 30% to 40% of these patients are long-term survivors. However, research has identified subgroups of patients who will respond well to therapy that is targeted to their specific biologic subtype of AML. Allogeneic bone marrow transplantation remains the only curative treatment for patients with chronic myeloid leukemia. Current efforts focus on improving risk-directed and subtype-specific treatment for the childhood leukemias. Ultimately, it may be possible to target treatments to the specific genetic lesions of leukemic cells.

Child↗