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Biomedical subjects

Thomas W McLean

Publications and source records attributed to Thomas W McLean.

14 recordsLinked to original sources

Acute myelogenous leukemia associated with Ollier disease.

Ollier disease is a rare disorder characterized by the presence of multiple enchondromas and a propensity to develop malignancies. We report the case of a 7-year-old Caucasian male with Ollier disease who developed acute myelogenous leukemia (AML). This report describes a patient with Ollier disease and AML and may offer a clue into the genetic pathogenesis of these disorders.

Aminoglycosides↗

Diagnosis of Burkitt lymphoma in pediatric patients by thoracentesis.

The diagnosis of Burkitt lymphoma by thoracentesis has been rarely reported in the literature, particularly in children. From 1995 to 2004, we diagnosed six pediatric patients with mature B-cell neoplasms using thoracentesis as the initial diagnostic procedure. The cytology, immunophenotyping, and cytogenetic results of the pleural fluid cells were consistent with mature B-cell malignancies. We conclude that thoracentesis for the diagnosis of Burkitt lymphoma in children is safe, fast, and accurate. It should be strongly considered as an initial diagnostic procedure for pediatric patients with pleural effusions who are suspected of having B-cell malignancies.

Adolescent↗

Hemophagocytic lymphohistiocytosis complicating influenza A infection.

During the influenza A (H3N2) season of 2003-2004, several influenza-related complications and deaths were reported in children. Hemophagocytic lymphohistiocytosis complicating influenza A infection is very rare. We report a 3-year-old girl who presented with severe pneumonia and hemophagocytic lymphohistiocytosis associated with influenza A infection. Clinicians should be aware of hemophagocytic syndrome as a serious complication of influenza A infection.

Bone Marrow↗

Catheter-related bacteremia due to Roseomonas species in pediatric hematology/oncology patients.

Roseomonas is a newly described genus of pink-pigmented, gram-negative bacteria. Human infections caused by Roseomonas species are very rare. We report two cases of central venous catheter-related bacteremia associated with Roseomonas species (one case with R. gilardii and one with R. fauriae), and review the clinical spectrum of previously reported cases in the literature. Clinicals should be aware that Roseomonas species may cause serious infections in children.

Bacteremia↗

Lifestyle, biomechanical, and bioenergetic complementary therapies in pediatric oncology.

After the diagnosis of cancer in a child is made, many families complement conventional medical care with lifestyle changes including diet, exercise, environment, and mind-body therapies. Biomechanical, bioenergetic, and other therapies are also sometimes sought. These include massage, chiropractic, acupuncture/acupressure, therapeutic touch, Reiki, homeopathy, and prayer. Some of these complementary therapies have well-established roles in cancer therapy for children, whereas others are controversial and require more research.

Child↗

Complementary and alternative medicine therapies in pediatric oncology patients.

Complementary and alternative medicine(CAM) therapies are commonly used by pediatric oncology patients. CAM therapies may be divided into four categories: biochemical, lifestyle, biomechanical, and bioenergetic. Surveys within the past decade estimate the prevalence of CAM use in pediatric oncology to be 31 to 87%, and in many cases the treating physician is unaware of the patients' CAM use. It is thus important to systematically ask patients and their parents about CAM therapies. Reliable resources are available for families and health care providers. Open, respectful communication, even in the absence of evidence, is crucial in both helping and protecting patients, and in avoiding conflicts.

Child↗

Central venous lines in children with lesser risk acute lymphoblastic leukemia: optimal type and timing of placement.

PURPOSE: In pediatric patients with acute lymphoblastic leukemia (ALL), the optimal time for central venous line (CVL) insertion and the optimal type of CVL (internal v external) is unclear. This study was undertaken to compare complication rates between early versus late line insertion, and between internal versus external lines in children with lesser risk ALL. PATIENTS AND METHODS: We performed a retrospective analysis of patients enrolled onto Pediatric Oncology Group (POG) protocol 9201. Data regarding demographics, CVL types and insertion dates, blood counts, and complications were reviewed through week 25 of therapy. RESULTS: Of 697 patients enrolled onto POG protocol 9201, 362 patients had sufficient data for analysis. When compared to late line placement (> day 15 of induction), early CVL placement (</= day 15 of induction) was associated with an increased risk of having a positive blood culture (odds ratio, 2.2; 95% CI, 1.0 to 5.0; P = .05). When compared with internal CVLs ("ports"), external CVLs were associated with a positive blood culture (odds ratio, 3.1; 95% CI, 1.3 to 7.5; P = .01), thrombosis (odds ratio, 3.9; 95% CI, 1.5 to 10.3; P = .006), and CVL removal (odds ratio, 5.6; 95% CI, 2.7 to 11.6; P < .001). CONCLUSION: In pediatric patients with lesser risk ALL, internal lines (ports) should be the preferred CVL type due to a lower risk of infectious and thrombotic complications. In addition, CVLs placed early in induction are associated with a higher risk of positive blood culture than those placed later in induction.

Antineoplastic Combined Chemotherapy Protocols↗

Retinitis following varicella in a vaccinated child with acute lymphoblastic leukemia.

Serious ocular disease following varicella (chickenpox) is rare in children. In addition, retinitis in children with hematologic malignancies may present a difficult diagnostic challenge because infectious retinitis may mimic leukemic involvement of the eye. We report a 7-year-old patient with T-cell acute lymphoblastic leukemia in remission who presented with visual complaints 2 weeks after developing chickenpox. Ophthalmologic evaluation revealed acute retinitis in the right eye. Prolonged therapy with acyclovir resulted in near complete recovery. Early diagnosis of VZV retinopathy and aggressive antiviral treatment is critical to prevent acute and long-term ocular sequelae.

Acyclovir↗

Recent steroid therapy increases severity of varicella infections in children with acute lymphoblastic leukemia.

OBJECTIVE: The varicella-zoster virus (VZV) continues to be a dangerous pathogen to immunocompromised children. Children with acute lymphoblastic leukemia (ALL) are treated with intermittent steroid therapy. This study was undertaken to examine the relationship between steroid therapy for ALL and severity of varicella infection. METHODS: We performed a retrospective review of patients who were on Pediatric Oncology Group Protocol 9201 and had a history of varicella infection. Pediatric Oncology Group 9201 is a phase III study for the treatment of children with lesser risk ALL diagnosed between 1992 and 1999. Cases of varicella were coded 1 to 5 on the basis of severity: grade 1 caused minimal to no symptoms, grade 2 caused mild to moderate symptoms that did not require hospitalization, grade 3 caused symptoms severe enough to require hospitalization and intravenous acyclovir, grade 4 caused severe disease that had complications or that required intensive care, and grade 5 resulted in death. RESULTS: Of 697 enrolled patients, 110 (15.8%) developed primary varicella; 59% of these were male. For analysis, disease grade was dichotomized into nonsevere (grades 1 and 2) and severe (grades 3, 4, and 5). Of the 110 patients, 56 had nonsevere disease; 54 had severe disease, including 2 deaths. Of the patients whose varicella was diagnosed within 3 weeks of receipt of prednisone, 70% had severe infection, whereas only 44% of those who had not received prednisone within 3 weeks had severe infection. The odds ratio for having a severe infection within 3 weeks of prednisone versus >3 weeks is 2.9 (95% confidence interval: 1.1-7.9). By multivariate analysis, older age at ALL diagnosis, years from ALL diagnosis to VZV diagnosis, and VZV diagnosis within the 4-week period of interest (during or within 3 weeks of prednisone therapy) all were independently associated with an increased risk for severe infection. CONCLUSIONS: This study represents the largest study to date of varicella in children with ALL and provides convincing evidence that prednisone therapy during the VZV incubation period significantly increases the risk for developing severe varicella infection. In addition, older age is associated with more severe infection. Despite the varicella vaccine and a dropping incidence of primary infections, VZV remains a dangerous pathogen for pediatric patients with ALL. With the possible exception of induction therapy, patients who are on ALL therapy and are exposed to varicella should have steroid therapy delayed until after the VZV incubation period. These findings may have implications for other diseases that are treated with corticosteroids.

Chickenpox↗

Neuroblastoma in an adult.

Neuroblastoma is extremely rare in adults. Advances in classification and therapy have been recently made by an analysis of pediatric tumors. We present the case of a 39-year-old man who had Stage 1 neuroblastoma with unfavorable histologic features that was treated with surgery only. Neuroblastoma should be considered as a diagnosis for adult patients with a suprarenal mass and, if confirmed, neuroblastoma in adults should be classified and treated according to pediatric guidelines.

Adrenal Gland Neoplasms↗

Medulloblastomas and central nervous system primitive neuroectodermal tumors.

Significant advances in the treatment of medulloblastoma and primitive neuroectodermal tumors have been made in the past three decades. Maximal surgical resection is a mainstay of therapy. However, unlike many other central nervous system neoplasms, medulloblastoma and primitive neuroectodermal tumors are radiation and chemotherapy responsive. Despite this response, the prognosis for patients with these tumors remains variable and is relatively poor in infants and patients with metastatic disease. These tumors most commonly arise in children, thus most clinical trials emphasize the reduction of long-term sequelae, in addition to improving survival. All newly diagnosed patients who are eligible should be offered participation in a clinical trial. If a patient is ineligible or declines consent/assent for a clinical trial, the best current treatment approach is surgical resection, followed by radiation therapy (except for children younger than 3 years) with weekly vincristine. For high-risk patients, 36 Gy of craniospinal irradiation should be delivered plus a boost of 19.8 Gy to the posterior fossa/primary tumor bed and sites of bulk metastatic disease. For average-risk patients, the craniospinal irradiation dose may be lowered to 23.4 Gy plus 32.4 Gy to the posterior fossa/tumor bed. After radiation therapy, intensive multimodal chemotherapy should be used for all patients.

Antineoplastic Agents↗

Religiosity is associated with the use of complementary medical therapies by pediatric oncology patients.

PURPOSE: To determine the prevalence of complementary and alternative medicine (CAM) use in pediatric oncology patients, the types of CAM used, and the factors associated with the use of CAM. PATIENTS AND METHODS: A questionnaire regarding CAM use was administered to patients/families seen in the pediatric oncology clinic at Wake Forest University Baptist Medical Center over a 12-month period. RESULTS: Based on 195 completed questionnaires, 91 (47%) patients reported use of CAM since diagnosis. Among CAM users, the most commonly used CAM therapies were faith healing, megavitamins/minerals, massage, other dietary supplements, relaxation techniques, and herbal medicines/teas. Forty-one percent of CAM users had not discussed CAM use with their physician(s). In bivariate analysis, CAM use was not associated with age at the time of survey, time since diagnosis, sex, race, parental education, or family income. A trend was noted between CAM use and older age at diagnosis. Families who reported themselves to be "very" religious were more likely to use CAM than those that are "somewhat" or "not at all" religious. CONCLUSIONS: Use of CAM is common among pediatric oncology patients and often is not discussed with the treating physician(s). Patients from very religious families are more likely to use CAM.

Child↗

The majority of children and adolescents with acute myeloid leukemia have detectable anti-DT388-GMCSF IgG concentrations, but at concentrations that should not preclude in vivo activity.

PURPOSE: As a novel approach for the treatment of acute myeloid leukemia (AML), the authors are developing a fusion toxin (DT(388)-GMCSF) consisting of a truncated diphtheria toxin (DT(388)) linked to human granulocyte-macrophage colony-stimulating factor (GMCSF). A critical step in the development of DT(388)-GMCSF for clinical use in childhood and adolescent AML is to determine whether children and adolescents have preexisting antibodies to DT(388)-GMCSF due to childhood immunizations against diphtheria toxoid. PATIENTS AND METHODS: Sera from 33 children and adolescents with AML and one with juvenile myelomonocytic leukemia were collected. The median age was 11.8 years. All scheduled diphtheria toxoid vaccinations were current except for the child diagnosed at 4 months of age. Anti-DT(388)-GMCSF antibody concentrations were detected by an enzymoimmunoassay and by an in vitro bioassay. RESULTS: Thirty of 34 (88%) children and adolescents had detectable anti-DT(388)-GMCSF IgG antibody concentrations. The median concentration was 1.5 microg/mL, with a range from undetectable to 191.4 microg/mL. There was a positive correlation between the enzymoimmunoassay and bioassay. There was no difference between the anti-DT(388)-GMCSF IgG concentrations in these children and adolescents with AML and in 43 adults with AML. Preliminary results of the phase 1 trial of DT -GMCSF in adults with AML indicate that patients with baseline anti-DT(388)-GMCSF IgG concentrations of less than 2 microg/mL can achieve circulating DT(388)-GMCSF concentrations and can exhibit antileukemic activity. Twenty-three of 34 (67.6%) children and adolescents had anti-DT(388)-GMCSF IgG concentrations less than 2 microg/mL. CONCLUSIONS: Despite routine diphtheria toxoid vaccinations, most children and adolescents with AML do not have anti-DT -GMCSF IgG concentrations that preclude in vivo activity of DT -GMCSF.

Adolescent↗