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J Belasco

Publications and source records attributed to J Belasco.

18 recordsLinked to original sources
PubMed2007

NF1 plexiform neurofibroma growth rate by volumetric MRI: relationship to age and body weight.

OBJECTIVE: To longitudinally analyze changes in plexiform neurofibroma (PN) volume in relation to age and body growth in children and young adults with neurofibromatosis type 1 and inoperable, symptomatic, or progressive PNs, using a sensitive, automated method of volumetric MRI analysis. METHODS: We included patients 25 years of age and younger with PNs entered in a natural history study or in treatment trials who had volumetric MRI over > or =16 months. RESULTS: We studied 49 patients (median age 8.3 years) with 61 PNs and a median evaluation period of 34 months (range 18 to 70). The PN growth rates varied among patients, but were constant within patients. Thirty-four patients (69%) experienced > or =20% increase in PN volume during the observation period. PN volume increased more rapidly than body weight over time (p = 0.026). Younger patients had the most rapid PN growth rate. CONCLUSIONS: Volume increase of plexiform neurofibromas is a realistic and meaningful trial endpoint. In most patients plexiform neurofibroma growth rate exceeded body growth rate. The youngest patients had the fastest plexiform neurofibroma growth rate, and clinical drug development should be directed toward this population. Age stratification for clinical trials for plexiform neurofibromas should be considered.

Aging↗
PubMed2000

Two primary osteosarcomas in a patient with Rothmund-Thomson syndrome.

Rothmund-Thomson syndrome is an autosomal recessive disorder characterized by poikilodermatous skin changes that develop in infancy. Associated manifestations include juvenile cataracts, sparse hair, short stature, skeletal defects, dystrophic nails and teeth, and hypogonadism. An increased incidence of malignancy, including osteosarcoma, has been reported in patients with Rothmund-Thomson syndrome. The molecular basis of the disorder is not known. This report describes a patient with Rothmund-Thomson syndrome in whom two primary osteosarcomas developed 12 years apart. The presentation, diagnosis, and treatment of osteosarcoma in this patient with Rothmund-Thomson syndrome are described. Cytogenetic and molecular analysis of peripheral blood and skin fibroblasts had low level mosaicism for trisomy of chromosomes 2 and 8. Although several patients have been described with mosaic trisomy 8 and i(2q) (mosaic isochromosome for the long arm of chromosome 2), the patient described here is the first to have mosaic trisomy for the entire chromosomes 2 and 8. The cytogenetic findings in this patient are consistent with an underlying defect in chromosomal stability.

Bone Neoplasms↗
PubMed1998

Emergent/urgent therapeutic irradiation in pediatric oncology: patterns of presentation, treatment, and outcome.

PURPOSE: We reviewed all pediatric cases referred for emergent/urgent therapy (requiring treatment within 48 hours) to identify frequency, patterns of presentation, and efficacy of therapy. We defined five categories of emergent/urgent therapy based on irradiated site and/or signs: Group I, spinal cord compression; Group II, respiratory compromise; Group III, infradiaphagmatic distress; Group IV, intracranial signs; Group V, pain. MATERIALS AND METHODS: From 2/1/88-3/1/ 94, 104 children with 115 problems were referred by specialists at the Children's Hospital of Philadelphia. Diagnosis, nature of the emergency, and response were examined. Responses were categorized as complete resolution, improvement or stabilization, and progression. RESULTS: The 104 children represented 12% of referrals during the study period. The most common tumors were CNS PNET and gliomas (20%); and neuroblastoma (20%). Forty-five problems occurred with newly diagnosed tumors and 70 after progression. Ninety-one episodes were managed with radiation therapy and 24 with other modalities. Patients with spinal cord/cauda equina (n = 33) compression improved (55%) or stabilized (30%). Patients with respiratory compromise from thoracic (n = 14) or abdominal (n = 5) disease had a response rate of 72%. Eight patients in group III had a 66% response. In Group IV (n = 16), 63% had complete responses and 19% had stabilization. Group V (n = 15) patients had a complete or partial response of 93%. CONCLUSION: Approximately 10% of children referred for radiation therapy required emergent/urgent treatment. Eighty percent of patients achieved stabilization or showed improvement in signs and symptoms, indicating that radiotherapy is a valuable and reliable component of multimodal care in such situations.

Adolescent↗
PubMed1993

Total-body irradiation and autologous bone marrow transplant in the treatment of high-risk Ewing's sarcoma and rhabdomyosarcoma.

PURPOSE: In an effort to improve outcome in patients with metastatic or high-risk localized Ewing's sarcoma family of tumors (ESF) and rhabdomyosarcoma (RMS), we explored the role of consolidation therapy with total-body irradiation (TBI) plus autologous bone marrow transplantation (ABMT). PATIENTS AND METHODS: Ninety-one patients were entered onto one of three consecutive protocols from 1981 to 1986. Induction therapy consisted of four or five cycles of vincristine, doxorubicin, and cyclophosphamide (VAdriaC); in the earlier series, patients received one or two cycles with dactinomycin instead of doxorubicin. Irradiation of the primary site was used for local control. Patients who attained a complete response (CR) to induction therapy were eligible for consolidation with 8 Gy TBI plus VAdriaC and ABMT. RESULTS: Nineteen patients were ineligible for consolidation after failing to achieve or maintain a CR following induction therapy; all 19 are dead of disease. Seven eligible patients elected to forgo consolidation; three of seven are long-term event-free survivors. Sixty-five patients received consolidation therapy; 20 of 65 are long-term event-free survivors. A local control rate of 83% was achieved using radiation therapy as the primary modality of local control. Patients with metastatic disease at diagnosis fared substantially worse than did patients with localized tumors (6-year event-free survival [EFS] rate, 14% v 38%; two-sided P [P2] = .008). CONCLUSIONS: Consolidation of patients with metastatic or high-risk localized pediatric sarcomas with 8 Gy TBI plus ABMT has failed to improve the outcome of this group of patients. Metastatic disease at diagnosis continues to confer the poorest prognosis. New therapeutic strategies are needed to consolidate more effectively the remissions that can be achieved in the majority of these patients.

Adolescent↗
PubMed1991

Chromosome 7 abnormalities in children with Down syndrome and preleukemia.

Three children, two boys and one girl, with Down syndrome (DS) who presented with preleukemia and loss of all or part of chromosome 7 were studied. Initial presentation, with cytopenias and less than 25% blasts in the bone marrow, was between 13 and 30 months of age. Progression to acute nonlymphocytic leukemia occurred 1-8 months after initial presentation. The morphologic type was megakaryoblastic in two, and undifferentiated in one. Two children achieved remission with intensive therapy, and one continues in remission off therapy; the other child died in remission of accidental causes. The third child died of respiratory distress and leukemia after no intervention was chosen. These cases represent the first examples of chromosome 7 abnormalities associated with DS and leukemia, and suggest differences from the "monosomy 7" syndrome seen in children without DS.

Child, Preschool↗
PubMed1991

Adjuvant chemotherapy of high-grade osteosarcoma of the extremity. Updated results of the Multi-Institutional Osteosarcoma Study.

The Multi-Institutional Osteosarcoma Study (MIOS) was designed to determine whether intensive multiagent adjuvant chemotherapy improves the outcome of patients with nonmetastatic high-grade osteosarcoma of the extremity as compared with concurrent controls. After definitive surgery of the primary tumor, patients were randomly assigned to immediate adjuvant chemotherapy or to observation without adjuvant treatment. Updated results of this trial indicate that the projected six-year event-free survival for the control group is 11% compared to 61% for the chemotherapy group (p less than 0.001). Similar results were observed in patients who declined randomization but who were followed according to the treatment arms of the protocol. When randomized and nonrandomized patients are pooled according to assigned treatment, a survival advantage favoring those patients treated with immediate adjuvant chemotherapy is apparent. An analysis of prognostic factors among patients receiving immediate adjuvant chemotherapy reveals that elevation of the serum lactic dehydrogenase at diagnosis is the factor most predictive of adverse outcome. Location of the primary site in the tibia confers a favorable prognosis. The authors conclude that the natural history of high-grade osteosarcoma of the extremity has not changed over the past two decades. The administration of immediate adjuvant chemotherapy has a significant favorable impact on event-free survival and should be recommended for all such patients.

Adult↗
PubMed1988

Preliminary results of treatment of Ewing's sarcoma of bone in children and young adults: six months of intensive combined modality therapy without maintenance.

Thirty-one previously untreated patients with Ewing's sarcoma were treated with an intensive chemotherapy program of vincristine, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and cyclosphosphamide (VADRIAC) in combination with radiation therapy to the primary site (greater than 50 Gy) and bone metastases (45 to 50 Gy). An intensified regimen with one further cycle of chemotherapy (VADRIAC), total body irradiation (TBI), and autologous bone marrow transplantation was given to patients with primary tumors of the pelvis, humerus, femur, and chest wall without metastases and to all patients with metastases at diagnosis. Patients with primary tumors of the distal extremity and other sites without metastases at diagnosis were treated on a less intensive chemotherapy regimen of VADRIAC without the intensification. Therapy was completed within 6 to 7 months in all patients. Thirteen patients had metastatic disease at diagnosis; only two of these had the lung as the sole site of metastatic disease. Eighteen patients had no evidence of metastatic disease at diagnosis: ten of these patients had tumors that arose in central axis and proximal extremity sites, and eight had tumors that arose in distal extremity and other sites. Thirty of the 31 patients achieved a complete remission, although two patients underwent amputation: one before chemotherapy and radiation and one after chemotherapy and radiation because of persistent local disease. Seventeen remain in their first complete remission at a median time on study of 30 months and a median time after completion of therapy of 24 months. Fourteen patients have relapsed (13) or progressed (1): ten in metastatic sites and four in the primary site. One patient had persistent local disease after radiation requiring amputation. Nine of the 13 patients with metastatic disease at diagnosis have relapsed compared with five of the 18 patients without metastatic disease. For the entire group, the actuarial survival is 78% (65% to 87%) at 30 months, and the actuarial disease-free survival is 58% (46% to 69%) at 30 months.

Adolescent↗
PubMed1987

Pediatric phase I trial and pharmacokinetic study of trimetrexate.

Trimetrexate, a new nonclassical antifolate, was evaluated in a phase I trial in children with refractory cancer including nine with acute leukemia and 21 with solid tumors. The drug was administered as an i.v. bolus injection weekly for three doses, and courses were repeated every 28 days. The dose ranged from 35 to 145 mg/m2. Thirty patients who received a total of 33 courses were evaluable for toxicity, including 19 who were evaluable for hematological toxicity. The maximally tolerated dose for patients with a solid tumor and leukemia was 110 mg/m2. The dose-limiting toxicities were myelosuppression, mucositis and a pruritic, diffuse maculopapular rash. Other side effects observed included transient, mild elevations of serum transaminases, mild nausea and vomiting, and a local phlebitis at the site of injection at higher dose levels. A single patient with delayed drug clearance had evidence of renal toxicity with a transient increase in serum creatinine. The pharmacokinetics of trimetrexate were studied in 25 patients over the entire dose range. There was considerable interpatient variability in total drug clearance (range 9.2 to 215 ml/min/m2) and half-life (2.1 to 20 h). There was a suggestion of a correlation between plasma concentration at 24 h and the development of hematological toxicity at the highest dose level. Trimetrexate was cleared primarily by biotransformation with renal clearance accounting for only 10% of total clearance. Two metabolites of trimetrexate which inhibit the enzyme dihydrofolate reductase were identified in the urine. One of these appears to be a glucuronide conjugate.

Adolescent↗
PubMed1987

Biological consequences of segmental alterations in mRNA stability: effects of deletion of the intercistronic hairpin loop region of the Rhodobacter capsulatus puf operon.

It has been proposed that intercistronic stem and loop structures located in the puf operon of the photosynthetic bacterium Rhodobacter capsulatus account for segmental differences in transcript stability and consequently, the differential expression of the B870 and reaction center (RC) proteins encoded by puf. We report here that deletion of these structures leads to a failure to detect as discrete fragments the B870-encoding 0.49 kb and 0.50 kb mRNA segments located upstream from the site of the hairpins. The absence of these stable transcript fragments is associated with altered stoichiometry of the B870 and RC pigment-protein complexes in the bacterial intracytoplasmic membrane and a decreased rate of cell growth under photosynthetic conditions. These results support the view that the hairpin loop structures of the puf intercistronic region function in vivo to impede exoribonucleolytic degradation of upstream mRNA and establish that segmental variations in mRNA stability have a biologically important role in regulating the expression of puf operon genes.

Base Sequence↗
PubMed1987

Treatment of peripheral neuroepithelioma in children and young adults.

Seventeen patients with peripheral neuroepithelioma were treated with an intensive chemotherapy regimen of vincristine, Adriamycin (Adria Laboratories, Columbus, OH), and cyclophosphamide (VADRIAC) in combination with radiation therapy. Fifteen patients with stage III (seven) or stage IV (eight) at presentation were treated on a more intensive regimen including total body irradiation (TBI) (8 Gy). Two patients with stage I (one) or II (one) disease received a less intensive chemotherapy regimen of VADRIAC. Therapy was completed within 6 to 7 months in all patients. The disease arose in the chest wall in 12 patients, pelvis in three patients, and extremity in two patients. Sixteen of the 17 (94%) patients achieved a complete remission. With a median follow-up of 18 months, ten patients remain in complete remission with an actuarial survival of 68% and an actuarial relapse-free survival of 56% at 12 months. On the basis of our initial experience with this tumor, we believe that peripheral neuroepithelioma is a chemoresponsive and radioresponsive tumor.

Adolescent↗
PubMed1986

Incidence, presentation, and outcome of spinal cord disease in children with systemic cancer.

During a 40-month period, in 24 of 643 (4%) newly diagnosed patients with systemic cancer younger than 18 years of age (range: 3 months to 17 years) spinal cord disease developed. Patients with spinal cord disease included 21 children with metastatic spinal cord compression, two with treatment-related transverse myelopathies, and one with an anterior spinal artery stroke. Spinal cord disease occurred in 13 of 102 children (12%) with sarcomas, six of 82 (7%) with neuroblastomas, and four of 94 (4%) with lymphomas. Spinal cord compression occurred as the presenting sign of malignancy in six children (four with sarcomas and two with lymphomas). In the remaining 15 patients, cord compression occurred a median of 13 months after initial diagnosis, and in four patients it occurred at the time of first relapse. Symptoms of metastatic cord compression included back pain in 17 patients (80%), weakness in 14 (67%), sphincter dysfunction in 12 (57%), and sensory abnormalities in three (14%). Findings on plain radiographs of the spine were abnormal in only seven of 20 patients with cord compression, and myelography was needed to differentiate compression from other causes of spinal cord disease. Treatment included high-dose corticosteroids followed by operation (seven patients) or radiotherapy (14 patients). After treatment, nine of 15 nonambulatory patients became ambulatory, and five of 10 incontinent patients regained sphincter control. None of the patients with nonmetastatic spinal cord disease had a satisfactory outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Phase I and clinical pharmacological study of mercaptopurine administered as a prolonged intravenous infusion.

The bioavailability of oral mercaptopurine (MP) is poor, and plasma levels following p.o. dosing are highly variable. In an attempt to circumvent these problems, we conducted a Phase I trial and clinical pharmacological study of MP administered as a prolonged i.v. infusion. An infusion rate of 50 mg/sq m/h, which was designed to achieve therapeutic drug levels in plasma, was used in all patients. The infusion duration was escalated in 12-h increments. Thirty-eight patients were evaluated. The dose-limiting toxicity was mucositis. Other reversible toxicities were myelosuppression and hepatotoxicity. An infusion duration of 48 h was found to be safe, unassociated with dose-limiting toxicity. Objective responses were seen in five patients. The mean plasma steady-state MP concentration achieved was 6.9 microM with little interpatient variability seen. Allopurinol coadministration had no effect on the plasma pharmacokinetics of i.v. MP. However, allopurinol did alter the urinary metabolite pattern, decreasing thiouric acid and increasing MP and thioxanthine levels. The steady-state cerebrospinal fluid:plasma ratio for MP was 0.27, suggesting that this approach may be of value in the treatment of central nervous system cancer. MP can be safely administered as a 48-h i.v. infusion at a dose rate which reliably achieves MP levels associated with optimal antileukemic activity in vitro.

Drug Evaluation↗
PubMed1981

Phase II evaluation of mitomycin C (MMC) in children with refractory solid tumors using the single high-intermittent-dose schedule.

Nine evaluable patients with refractory solid tumors received mitomycin C as a single intravenous injection at a dose of 20 mg/m2 at 6- to 8-week intervals. Toxicity was tolerable. One patient with Wilms' tumor had a transient decrease in liver size. Pharmacokinetic data on three patients have suggested that the disposition of mitomycin C were comparable to those obtained in adults.

Adolescent↗
PubMedDate not supplied

Wilms' tumor.

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Child↗