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Biomedical subjects

J Eddy

Publications and source records attributed to J Eddy.

15 recordsLinked to original sources

Dideoxyinosine in children with symptomatic human immunodeficiency virus infection.

BACKGROUND: 2',3'-Dideoxyinosine (ddl) is a dideoxynucleoside with potent activity in vitro against the human immunodeficiency virus (HIV). In initial clinical trials in adults, ddl showed evidence of antiretroviral activity with little hematologic toxicity. METHODS: We conducted a phase I-II study in 43 children with symptomatic (CDC class P-2) HIV infection. Of these children, 16 (median age, 10 years) had previously received zidovudine, and 27 (median age, 2.6 years) had not. ddl was administered orally in three divided doses totalling 60, 120, 180, 360, or 540 mg per square meter of body-surface area per day for 24 weeks. Eight of the 43 patients did not complete 24 weeks of ddl: 6 died, 1 was withdrawn because of progressive disease, and the other because of toxicity. RESULTS: After oral administration, ddl was rapidly absorbed, although its bioavailability varied greatly among patients. Pancreatitis developed in two children, one receiving ddl at each of the two highest doses. The median CD4 cell count in 38 patients with paired counts increased from 0.218 x 10(9) per liter (218 per cubic millimeter) at base line to 0.327 x 10(9) per liter (327 per cubic millimeter) after 20 to 24 weeks (P = 0.001). Those with CD4 cell counts above 0.1 x 10(9) per liter (100 per cubic millimeter) at base line were significantly more likely to improve in this respect. The median levels of p24 antigen (in 27 patients with detectable levels at entry) declined from 272 pg per milliliter at base line to 77 pg per milliliter at 20 to 24 weeks (P = 0.005). The plasma concentration of ddl correlated significantly with both the degree of decline in the p24 antigen and the degree of improvement in IQ score. Improvement in clinical and immunologic measures occurred in both the previously untreated patients and in those who had been treated with zidovudine. CONCLUSIONS: Dideoxyinosine was well tolerated and showed promising antiretroviral activity in HIV-infected children. The correlation between the clinical response and the plasma concentration of ddl indicates that bioavailability is an important consideration in the use of ddl to treat HIV infection and that individualized pharmacokinetic monitoring and dose adjustment may be important for optimal activity.

Administration, Oral

Direct intralymphatic injection of radiolabeled 111In-T101 in patients with cutaneous T-cell lymphoma.

Direct intralymphatic administration of radiolabeled monoclonal antibody in targeting antigen-bearing lymphoma cells in regional lymph nodes of patients with cutaneous T-cell lymphoma was evaluated. Seven consecutive patients undergoing staging lymphangiography received intralymphatic infusions of 111In-T101 to evaluate lymph node involvement. This procedure was accomplished without significant complication. The 111In-T101 rapidly distributed throughout the regional lymphatic compartment and passed into the systemic circulation. Tumor-bearing sites in the inguinal-femoral lymph nodes retained from 0.42 to 4.8% of the injected dose of radiolabeled antibody. Three patients were upstaged to Stage IVA based on tumor involvement found after radiolymphoscintigraphy-directed biopsy of groin lymph nodes, selected because of intense radioactivity by gamma camera imaging. Compared with previously reported s.c. antibody administration, there was a marked reduction in the radioactive exposure of normal tissues at the injection sites in the lower extremities. Direct intralymphatic delivery of 111In-T101 appears to be a feasible, efficient method for delivering therapeutic doses of radiolabeled antibody.

Adult

Brain growth and cognitive improvement in children with human immunodeficiency virus-induced encephalopathy after 6 months of continuous infusion zidovudine therapy.

The ventricular area at the level of the foramen of Monro was measured from axial x-ray computed tomography (CT) scans obtained prior to and 6 months after the initiation of continuous infusion of zidovudine (ZDV) in eight children with human immunodeficiency virus-induced encephalopathy. Evidence of moderate to severe central atrophy was present on initial CT scans (p less than 0.05). Ventricular area and ventricular brain area ratio (VBR) decreased after ZDV therapy in seven of eight children (mean decrease of 21.5 and 20%, respectively, p less than 0.05). The degree of decrease in VBR correlated with reductions in cerebrospinal fluid (CSF) protein concentration (r = 0.93, p less than 0.01), but not lymphocyte T4 or T8 counts. Intelligence quotients (IQs) improved in all seven children tested (mean improvement of 17.7%, p less than 0.01) and correlated significantly with reductions in CSF protein concentration (r = -0.85, p = 0.003). The magnitude of IQ changes was not significantly correlated with the magnitude of changes in ventricular area. We conclude that the cognitive improvement of HIV encephalopathy seen after 6 months of continuous infusion of ZDV is accompanied by reduction in brain atrophy and decreased CSF protein, suggesting an ameliorating effect of ZDV on the pathogenesis of AIDS encephalopathy in children.

AIDS Dementia Complex

Effect of continuous-infusion zidovudine therapy on neuropsychologic functioning in children with symptomatic human immunodeficiency virus infection.

Neuropsychologic function was assessed in 13 children with symptomatic human immunodeficiency virus disease (Centers for Disease Control Class P2), ranging in age from 14 months to 12 years. Before the initiation of treatment, eight patients were classified as having encephalopathy. Psychologic tests were administered both before and after 6 and 12 months of continuous-infusion azidothymidine (AZT; zidovudine) treatment. After 6 months of treatment a significant increase of 15.5 (+/- 3.3) IQ points was demonstrated in general cognitive functioning (p less than 0.001). Follow-up for 10 of these patients indicated that after 12 months of AZT therapy, they had maintained their gains in IQ points. Improvements in adaptive behavior after 6 months of therapy, assessed with a standardized interview, paralleled the findings on the IQ data. No significant differences in the amount of change was observed for the different subgroups. The magnitude of these improvements could not be explained by practice effects, environmental changes, or general improvement in physical state. We conclude that neuropsychologic function was significantly improved with continuous infusion AZT treatment.

AIDS Dementia Complex

Impairment of neutrophil chemotactic and bactericidal function in children infected with human immunodeficiency virus type 1 and partial reversal after in vitro exposure to granulocyte-macrophage colony-stimulating factor.

Because polymorphonuclear neutrophils are the most important component of host defense against bacteria, we assessed their function in 13 children with asymptomatic and 12 with symptomatic infection with human immunodeficiency virus type 1 (HIV-1), and compared their values with healthy adult control values. The functions assessed were (1) chemotaxis, (2) bacterial phagocytosis, (3) superoxide generation, and (4) bactericidal activity. Chemotaxis of polymorphonuclear neutrophils toward the chemoattractant N-formylmethionyl leucyl phenylalanine (FMLP) was significantly decreased in symptom-free infected children compared with control subjects (p less than 0.0001), but was increased in children with symptomatic infection (p less than 0.025). Bactericidal activity of the neutrophils against Staphylococcus aureus was defective in 8 of 12 children with asymptomatic infection (p = 0.016), and in 8 of 9 children with symptomatic infection (p less than 0.00001). Superoxide generation by polymorphonuclear neutrophils on stimulation with FMLP and phagocytosis of S. aureus were normal. Serum from patients with symptomatic HIV-1 infection was not as efficient in low concentrations as normal serum in the ability to opsonize S. aureus. The in vitro bactericidal defect was partially corrected by granulocyte-macrophage colony-stimulating factor (GM-CSF). The results suggest that both cellular (neutrophils) and humoral defects contribute to the increased incidence of bacterial infections in HIV-1-infected children, and that GM-CSF may improve the defective bactericidal activity of polymorphonuclear neutrophils in these patients.

Adolescent

Safety and tolerance of intermittent intravenous and oral zidovudine therapy in human immunodeficiency virus-infected pediatric patients. Pediatric Zidovudine Phase I Study Group.

Thirty-five children with symptomatic human immunodeficiency virus infection were enrolled in a 12-week, three-center phase I study of intravenous and oral zidovudine therapy. At enrollment the children ranged in age from 5 months to 13 years, with a median age of 3 1/2 years. Twenty-one children (60%) had acquired immunodeficiency syndrome and 14 (40%) had the related complex; 20 children had less than 0.5 10(9) CD4+ lymphocytes per liter (less than 500 cells/mm3) at entry. Zidovudine was administered in one of three escalating dose regimens. One or two months of intravenous treatment with zidovudine every 6 hours was followed by orally administered drug on the same schedule; zidovudine was infused at 80, 120, or 160 mg/m2/dose, and the oral dose was one and one-half times the intravenous dosage. Adverse events were similar to those observed in adults. Neutropenia (absolute neutrophil count less than 0.75 10(9)/L (750 cells/mm3] occurred in nine patients. The median neutrophil count fell from 2.50 10(9)/L at entry to 1.72 10(9)/L at the end of the study. Anemia requiring transfusion occurred in seven 10(9)/L at the end of the study. Anemia requiring transfusion occurred in seven patients; the median hemoglobin level among nontransfused patients decreased from an entry value of 108 to 105 gm/L (10.8 to 10.5 gm/dl). Dosage adjustments were made in 15 patients, in 12 because of anemia or neutropenia. No patients required permanent discontinuation of zidovudine because of toxic effects. Positive effects included a faster-than-anticipated rate of weight gain, decreased hepatosplenomegaly, and lowering of the total IgG and IgM concentrations toward more normal values. Zidovudine appears to be safe and to have manageable toxic effects in children.

AIDS-Related Complex

Dideoxycytidine alone and in an alternating schedule with zidovudine in children with symptomatic human immunodeficiency virus infection.

OBJECTIVE: To determine whether a short course of 2',3'-dideoxycytidine (ddC) could provide safe antiretroviral activity in children with symptomatic human immunodeficiency virus infection and whether it could be used with azidothymidine (AZT, zidovudine). The goal was to maintain uninterrupted antiretroviral therapy while sparing AZT-related myelosuppression and ddC-related neuropathy. METHODS: In a pilot study, we evaluated four dosage levels of ddC--0.015, 0.02, 0.03, and 0.04 mg/kg, given orally every 6 hours--in 15 children between 6 months and 13 years of age with Centers for Disease Control P2 (i.e., symptomatic) human immunodeficiency virus infection. Thirteen patients had not had any prior antiretroviral therapy; two patients had received and benefited from AZT, but dose-limiting neutropenia had developed. At each dosage level, ddC was given for 8 consecutive weeks and then stopped. After a 30-day rest, a schedule of ddC for 1 week was followed by 3 weeks of AZT therapy (180 mg/m2 every 6 hours); this alternating schedule was repeated for as long as tolerated. Age-appropriate psychometric testing was performed before the start of ddC therapy and after 8 weeks. RESULTS: During the 8 weeks of therapy with ddC alone, no neutropenia or anemia was observed; 6 of 9 patients had decreases in p24 antigen levels, and 8 of 15 had an increased CD4 cell count. At the 0.04 mg/kg level, a rash developed in three patients; mild mouth sores developed in 9 of 15 patients. On the alternating ddC/AZT schedule, no neuropathy was observed. CONCLUSIONS: 2',3'-Dideoxycytidine has antiretroviral activity in some children and appears to be safe for short intervals. Longer courses of ddC at lower dosage levels, and schedules integrating ddC into combination regimens, deserve to be explored.

Acquired Immunodeficiency Syndrome

The pharmacokinetics of zidovudine administered by continuous infusion in children.

STUDY OBJECTIVE: To define the pharmacokinetics of zidovudine (azidothymidine) in children with human immunodeficiency virus infection. DESIGN: Plasma, urine, and cerebrospinal fluid were obtained following a single 80 mg/m2 body surface dose infused over 1 hour (n = 9), and during a continuous infusion of 0.5 (n = 3), 0.9 (n = 8), 1.4 (n = 7), or 1.8 (n = 3) mg/kg body weight per hour. SETTING: Outpatient clinic and inpatient ward of the Pediatric Branch of the National Cancer Institute. PATIENTS: Twenty-one children (seventeen boys) ranging in age from 14 months to 12 years with symptomatic human immunodeficiency virus infection who were being treated on a phase I-II study of continuous intravenous infusion zidovudine. MEASUREMENTS AND MAIN RESULTS: Zidovudine disappearance following bolus administration was rapid and biexponential with half-lives of 9.6 and 92 minutes, and a total clearance of 705 +/- 330 mL/min.m2. Zidovudine remained above 1 mumol/L, the optimal virostatic concentration in vitro, for only 1.5 hours. In contrast, with continuous infusion steady-state plasma zidovudine concentrations (Css) were maintained above 1 mumol/L continuously, even at the lowest infusion rate. At steady state the ratio of cerebrospinal fluid zidovudine concentration to plasma was 24% +/- 9%. Patients who developed severe neutropenia (absolute neutrophil count less than 0.5 X 10(9)/L) on the continuous infusion regimen had significantly higher plasma Css. Six of eight had a Css greater than 3.0 mumol/L. CONCLUSIONS: Pharmacokinetic parameters show that continuous infusion is better than an intermittent schedule in maintaining minimal virostatic concentrations of the drug with a lower daily dose.

Acquired Immunodeficiency Syndrome

Pharmacokinetics of zidovudine administered intravenously and orally in children with human immunodeficiency virus infection.

Zidovudine pharmacokinetics were determined in 16 children with human immunodeficiency virus infection who were being treated intravenously and orally on an intermittent schedule (every 6 hours). The intravenous doses studied were 80 (n = 3), 120 (n = 4), and 160 (n = 5) mg/m2/dose, infused over 1 hour. Fourteen patients were monitored after an oral dose of zidovudine at 120 (n = 2), 180 (n = 7), or 240 (n = 5) mg/m2/dose. Zidovudine was assayed with a reverse-phase high-pressure liquid chromatography method. Zidovudine disappearance after intravenous administration was rapid and biexponential, with half-lives of 14 and 90 minutes and a total clearance of 641 +/- 161 ml/min/m2. The volume of distribution at steady state was 45 +/- 28 L/m2. These pharmacokinetics parameters are very similar to those reported in adults. When administered orally, zidovudine was rapidly absorbed. The fraction of the oral dose that was bioavailable was 0.68 +/- 0.25, so that a 50% increment in the dose, in the conversion from intravenous to oral administration, resulted in plasma zidovudine concentrations after oral dosing that were nearly identical to those achieved with the 1-hour intravenous infusion. However, a dose of 180 mg/m2 given orally every 6 hours maintained plasma zidovudine concentrations in the target range of 1 mumol/L for less than half of the dosing interval. Other schedules, routes of administration, or oral drug formulations may have to be considered if sustained continuous exposure to micromolar zidovudine concentrations is desired.

Acquired Immunodeficiency Syndrome

Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study.

Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

Acquired Immunodeficiency Syndrome

Response to thoracic radiotherapy in patients with small cell carcinoma of the lung after failure of combination chemotherapy.

Chest radiotherapy was given to 23 patients with small cell carcinoma of the lung after development of progressive intrathoracic tumor on chemotherapeutic regimens. Treatment schedules were variable, with a median dose of 3,200 rad (32 Gy) in 10 fractions. Objective tumor regression within the radiation portal was observed in 12 patients (52%). Only 3/12 responders did not develop clinically detectable local tumor recurrence before death. Actuarial median time to local tumor progression was 2.5 months in responding and 3.5 months in nonresponding patients. Relapse of intrathoracic small cell carcinoma despite combination chemotherapy was not effectively treated by chest irradiation in the doses utilized. If sustained local palliation is required in this population, higher doses of radiation should be considered.

Carcinoma, Small Cell