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Biomedical subjects

P Waldron

Publications and source records attributed to P Waldron.

13 recordsLinked to original sources
PubMed2003

Study group funding.

Explore the source record for details and available documents.

Education, Dental, Continuing↗
PubMed1999

Interferon treatment of chronic active hepatitis C during therapy of acute lymphoblastic leukemia.

Due to concerns that antineoplastic therapy produces prolonged decrease in immune function, interferon treatment of chronic active hepatitis C (CAHC) has been used only at one year or longer after the end of cancer therapy. We report the experience of an 11-year-old who developed symptomatic CAHC at the start of maintenance therapy for testicular relapse of acute lymphoblastic leukemia (ALL). Significant dose reduction of maintenance therapy did not improve the tolerance of antileukemic treatment. In an effort to improve his liver disease and to deliver effective antileukemic therapy, interferon alpha and an alternative maintenance therapy regimen for ALL were initiated. The patient tolerated the combined therapy well. Interferon therapy was continued for 27 months, which was three months from the end of antineoplastic therapy. At that time serum transaminase values were normal, and no HCV viral genome was detectable. Viral genome was detected 10 months later. The combined effects of interferon and antineoplastic therapy resulted in myelosuppression requiring dose reduction of both treatments. The patient remains asymptomatic and with no evidence of recurrent leukemia more than six years from diagnosis of relapse. The effect on the status of this patient's CAHC was similar to that reported among leukemic patients who underwent an interferon course more than one year from the end of antineoplastic therapy. Interferon treatment of CAHC can be given concomitantly with antineoplastic therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

ABO hemolytic disease of the newborn: a unique constellation of findings in siblings and review of protective mechanisms in the fetal-maternal system.

Two siblings born 6 years apart presented with similar findings of hepatosplenomegaly, dermal hematopoiesis, hemoglobinuria, and increased platelet consumption, but only moderate anemia and normal serum bilirubin. ABO incompatibility was identified, and other causes were excluded. A review of the current understanding of mechanisms that promote and prevent antibody-mediated hemolysis in the fetus is reviewed. Due to the low ratio of observed to expected significant clinical events among ABO incompatible mother-infant pairs, and the multiplicity of mechanisms that diminish hemolysis, we speculate that severe ABO hemolytic disease of the newborn occurs when there is a specific failure in one of these preventive mechanisms.

ABO Blood-Group System↗
PubMed1994

Malignant rhabdoid tumor of the kidney: involvement of chromosome 22.

Cytogenetic and molecular studies have demonstrated that involvement of 22q is a non-random finding in malignant rhabdoid tumors (MRTs) of the brain. We present an MRT of the kidney with the karyotype 47,XY, + i(1)(q10), der(8)t(8;22)(q12;q11.2),der(22)t(8;22)(q23 or q24.1;q11.2). This unbalanced reciprocal translocation was confirmed by fluorescence in situ hybridization (FISH) with chromosome-specific paints for chromosomes 8 and 22. Molecular analysis demonstrated a partial deletion of 22q in the BCR region at q11.2, strengthening the suspicion that this is a critical region for the initiation or progression of these highly malignant neoplasms. Establishing non-random cytogenetic changes in MRTs arising from the kidney may be of value in distinguishing these rare, but often fatal tumors from other renal neoplasms that mimic them histologically. The similarity in cytogenetic and molecular abnormalities between renal and extra-renal MRTs argues against the concept that extra-renal MRTs are only representative of a rhabdoid phenotype, rather than being true rhabdoid tumors.

Child, Preschool↗
PubMed1994

Cytosine arabinoside and mitoxantrone treatment of relapsed or refractory childhood leukemia: initial response and relationship to multidrug resistance gene 1.

The objective of this study was to determine the response rate and toxicity of high-dose cytosine arabinoside (AC) and mitoxantrone (M) in relapsed or refractory childhood acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) and to correlate response with the expression of the multidrug resistance gene 1 (mdr1). Twenty-nine patients were treated with AC 1.0 g/m2 infused over 2 h every 12 h for eight doses (days 1-4) and M 12 mg/m2 infused over 1 h (days 3-6). Mdr1 expression was determined by a polymerase chain reaction (pcr) assay. Ten of 15 patients (67%) with AML obtained a complete remission (CR) of 3 to 30+ months duration. Eight of 14 (57%) ALL patients obtained a CR of 1 to 23+ months duration. The major toxicities were hematopoietic and infectious. Seventy-nine per cent of patients developed a documented infection during induction. Mdr1 did not correlate with a lower induction rate. This AC/M regimen is active in childhood AML and ALL.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Clonal remission in childhood acute myeloid leukemia is an infrequent event.

Acute myeloid leukemia (AML) is a heterogeneous group of diseases that differ in pattern of both remission and lineage involvement. The observation that hematopoiesis remains clonal in some patients with AML in complete clinical remission suggests that the acute phase may develop from a clinically unrecognized preleukemic clone. To investigate the characteristics and significance of clonal remissions in childhood AML, we used X-chromosome-linked polymorphisms to study granulocytes obtained from pediatric female patients in complete clinical remission. Remission granulocytes from only one of 17 evaluable patients were clonally derived, suggesting that clonal remission is an infrequent event in childhood AML.

Acute Disease↗
PubMed1982

Cognitive tempo and cognitive level relationships among mentally retarded children.

The purpose of this investigation was to ascertain predictive relationships between and within cognitive tempo and cognitive level characteristics of 33 moderately retarded junior high school children. The Matching Familiar Figures Test was used to establish cognitive tempo characteristics and the Essential Math and Language Skills Inventory was used to determine cognitive level characteristics. A multiple regression analysis indicated no significant predictive relationship from elements of cognitive tempo to elements of cognitive level. Elements of cognitive level, however, could predict elements of cognitive tempo. Implications for future research were discussed. Cross-validation on a larger sample is required.

Adolescent↗
PubMedDate not supplied

Tonsillectomy, adenoidectomy, and myringotomy in sickle cell disease: perioperative morbidity. Preoperative Transfusion in Sickle Cell Disease Study Group.

PURPOSE: To compare the rates of perioperative morbidity of patients with sickle cell anemia who were randomly assigned to 2 preoperative transfusion regimens and to identify predisposing factors for perioperative complications. PATIENTS AND METHODS: Investigators at 36 centers enrolled 118 patients who were scheduled to have elective surgery and agreed to randomization between 2 preoperative transfusion regimens. Forty-seven subjects were enrolled but not randomized, including 20 who were not transfused before surgery. Perioperative management was based on a prescribed care plan. RESULTS: Tonsillectomy and/or adenoidectomy (TA) were performed on 136 persons, and 29 had myringotomy as their primary procedure. There were no differences in the frequency of complications between the randomized groups. The serious, non-transfusion complication rates for randomized patients were 32% (34 of 107) for TA and 36% (4 of 11) for myringotomy. A history of pulmonary disease was a predictor of postoperative sickle cell-related events for patients undergoing TA surgery. CONCLUSIONS: The more intensive transfusion regimen did not result in fewer perioperative complications. The high frequency of complications emphasizes the need for anticipatory management of persons undergoing TA. A history of pulmonary disease identifies patients at increased risk for sickle cell-related events after TA surgery. Patients undergoing myringotomy have a low frequency of sickle cell-related events but a significant frequency of other serious perioperative complications.

Adenoidectomy↗