Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 96
Filter
1.
J Phys Chem A ; 115(16): 3917-23, 2011 Apr 28.
Article in English | MEDLINE | ID: mdl-21241060

ABSTRACT

Highly nonlinear pump fluence dependence was observed in the ultrafast one-color pump-probe responses excited by 38 fs pulses resonant with the E(22) transition in a room-temperature solution of (6,5) carbon nanotubes. The differential probe transmission (ΔT/T) at the peak of the pump-probe response (τ = 20 fs) was measured for pump fluences from ∼10(13) to 10(17) photons/pulse cm(2). The onset of saturation is observed at ∼2 × 10(15) photons/pulse cm(2) (∼8 × 10(5) excitons/cm). At pump fluences >4 × 10(16) photons/pulse cm(2) (∼1.6 × 10(6) excitons/cm), ΔT/T decreases as the pump fluence increases. Analogous signal saturation behavior was observed for all measured probe delays. Despite the high exciton density at saturation, no change in the E(22) population decay rate was observed at short times (<300 fs). The pump probe signal was modeled by a third-order perturbation theory treatment that includes the effects of inhomogeneous broadening. The observed ΔT/T signal is well-fit by a pump-fluence-dependent dephasing rate linearly dependent on the number of excitons created by the pump pulse. Therefore, the observed nonlinear pump intensity dependence is attributed to the effects of quasi-elastic exciton-exciton interactions on the dephasing rates of single carbon nanotubes. The low fluence total dephasing time is 36 fs, corresponding to a homogeneous width of 36 meV (290 cm(-1)), and the derived E(22) inhomogeneous width is 68 meV (545 cm(-1)). These results are contrasted with photon-echo-derived parameters for the E(11) transition.


Subject(s)
Electrons , Nanotubes, Carbon/chemistry , Thermodynamics , Time Factors
2.
J Phys Chem B ; 115(18): 5201-11, 2011 May 12.
Article in English | MEDLINE | ID: mdl-21090793

ABSTRACT

We report a femtosecond transient absorption spectroscopic study on the (6, 5) single-walled carbon nanotubes and the (7, 5) inner tubes of a dominant double-walled carbon nanotube species. We found that the dynamics of exciton relaxation probed at the first transition-allowed state (E(11)) of a given tube type exhibits a markedly slower decay when the second transition-allowed state (E(22)) is excited than that measured by exciting its first transition-allowed state (E(11)). A linear intensity dependence of the maximal amplitude of the transient absorption signal is found for the E(22) excitation, whereas the corresponding amplitude scales linearly with the square root of the E(11) excitation intensity. Theoretical modeling of these experimental findings was performed by developing a continuum model and a stochastic model with explicit consideration of the annihilation of coherent excitons. Our detailed numerical simulations show that both models can reproduce reasonably well the initial portion of decay kinetics measured upon the E(22) and E(11) excitation of the chosen tube species, but the stochastic model gives qualitatively better agreement with the intensity dependence observed experimentally than those obtained with the continuum model.


Subject(s)
Nanotubes, Carbon/chemistry , Absorption , Algorithms , Kinetics , Semiconductors
3.
Nano Lett ; 10(5): 1589-94, 2010 May 12.
Article in English | MEDLINE | ID: mdl-20405819

ABSTRACT

We report on light emission from biased metallic single-wall carbon nanotube (SWNT), multiwall carbon nanotube (MWNT) and few-layer graphene (FLG) devices. SWNT devices were assembled from tubes with different diameters in the range 0.7-1.5 nm. They emit light in the visible spectrum with peaks at 1.4 and 1.8 eV. Similar peaks are observed for MWNT and FLG devices. We propose that this light emission is due to phonon-assisted radiative decay from populated pi* band states at the M point to the Fermi level at the K point. Since for most carbon nanotubes as well as for graphene the energy of unoccupied states at the M point is close to 1.6 eV, the observation of two emission peaks at approximately 1.6 +/- approximately 0.2 eV could indicate radiative decay under emission or absorption of optical phonons, respectively.


Subject(s)
Crystallization/methods , Electrochemistry/methods , Graphite/chemistry , Luminescent Measurements/methods , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Macromolecular Substances/chemistry , Materials Testing , Metals/chemistry , Molecular Conformation , Particle Size , Photons , Surface Properties
4.
Med Sci Sports Exerc ; 33(9): 1415-22, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11528327

ABSTRACT

BACKGROUND: Supplementation with propionyl-L-carnitine (PLC) may be of use in improving the exercise capacity of people with peripheral arterial disease. METHODS: After a 2-wk exercise familiarization phase, seven subjects displaying intermittent claudication were studied over a 12-wk period consisting of three 4-wk phases, baseline (B), supplementation (S), and placebo (P). PLC was supplemented at 2 g x d(-1), and subjects were blinded to the order of supplementation. Unilateral calf strength and endurance were assessed weekly. Walking performance was assessed at the end of each phase using an incremental protocol, during which respiratory gases were collected. RESULTS: Although there was not a significant increase in maximal walking time ( approximately 14%) in the whole group, walking time improved to a greater extent than the individual baseline coefficient of variation in four of the seven subjects. The changes in walking performance were correlated with changes in the respiratory exchange ratio both at steady state (r = 0.59) and maximal exercise (r = 0.79). Muscle strength increased significantly from 695 +/- 198 N to 812 +/- 249 N by the end of S. Changes in calf strength from B to S were modestly related to changes in walking performance (r = 0.56). No improvements in calf endurance were detected throughout the study. CONCLUSIONS: These preliminary data suggest that, in addition to walking performance, muscle strength can be increased in PAD patients after 4 wk of supplementation with propionyl-L-carnitine.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Carnitine/analogs & derivatives , Carnitine/pharmacology , Exercise/physiology , Intermittent Claudication/drug therapy , Peripheral Vascular Diseases/complications , Walking/physiology , Adult , Aged , Aged, 80 and over , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Carnitine/administration & dosage , Female , Humans , Male , Middle Aged , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiology , Peripheral Vascular Diseases/drug therapy , Physical Endurance , Single-Blind Method , Treatment Outcome
5.
Phys Rev Lett ; 87(27 Pt 1): 272301, 2001 Dec 31.
Article in English | MEDLINE | ID: mdl-11800873

ABSTRACT

The parity-violating longitudinal analyzing power, A(z), has been measured in pvectorp elastic scattering at an incident proton energy of 221 MeV. The result obtained is A(z) = [0.84+/-0.29(stat)+/-0.17(syst)]x10(-7). This experiment is unique in that it selects a single parity violating transition amplitude (3P2 - 1D2) and consequently directly constrains the weak meson-nucleon coupling constant h(pp)(rho). When this result is taken together with the existing pvectorp parity violation data, the weak meson-nucleon coupling constants h(pp)(rho) and h(pp)(omega) can, for the first time, both be determined.

7.
Bone Marrow Transplant ; 20(7): 543-51, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9337055

ABSTRACT

A single institutional pilot study was conducted in which 12 poor-risk neuroblastoma (NB) patients were uniformly treated with multi-agent induction chemotherapy followed by myeloablative consolidation chemotherapy and unpurged peripheral blood stem cell (PBSC) rescue. In addition to using standard criteria for evaluating response to induction chemotherapy, tumor cell contamination of the peripheral blood and/or bone marrow was analyzed in seven patients by immunocytology using a panel of five anti-NB monoclonal antibodies. Seven patients had morphologic evidence of bone marrow disease at the time of diagnosis, and two additional patients had tumor cells detected in bone marrow samples by immunocytology prior to the second cycle of chemotherapy. After three cycles of chemotherapy, two of the 12 patients continued to have evidence of bone marrow disease. Samples from 29 PBSC harvests collected from nine patients were also analyzed for the presence of contaminating tumor cells by immunocytology. In each case, the stem cells were found to be free of tumor. Eleven of the 12 patients underwent myeloablative therapy and PBSC rescue; five patients remain alive without disease progression, 28+ to 53+ months from diagnosis, and six patients have developed recurrent disease. We conclude that PBSCs can be successfully harvested from children with NB, and used for hematopoietic reconstitution following myeloablative chemotherapy. However, more effective therapy for poor-risk NB patients is still urgently needed.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Brain Neoplasms/therapy , Hematopoietic Stem Cell Transplantation , Neuroblastoma/therapy , Adult , Child, Preschool , Combined Modality Therapy , Female , Hematopoietic Stem Cell Mobilization , Humans , Infant , Male , Pilot Projects , Transplantation, Autologous , Treatment Outcome
8.
Horm Res ; 48(2): 88-92, 1997.
Article in English | MEDLINE | ID: mdl-9251926

ABSTRACT

We report the treatment of a 14-year-old Indian boy with acanthosis nigricans and hyperinsulinaemia with metformin in an attempt to improve his skin lesions. Oral metformin was used for 6 months with assessment of insulin status during an intravenous glucose tolerance test and hyperinsulinaemic-euglycaemic clamping before and after treatment. The first-phase insulin response reduced from 19,593 to 5,410 pmol/l/min (normal 1,900-13,400), and the second-phase insulin response improved from 59,120 to 34,020 pmol/l/min (normal 2,900-18,100). During hyperinsulinaemic-euglycaemic clamping hepatic glucose production was normally suppressed prior to therapy, but peripheral glucose remained abnormally low, 152 and 138% of basal (expected 199%). The acanthosis nigricans remained unaltered but over this period puberty progressed and his body mass index increased. We conclude that, in this patient, metformin had a minimal effect on the hyperinsulinism and none on the acanthosis nigricans in the relatively short term, but further studies in more patients over longer time intervals are warranted.


Subject(s)
Acanthosis Nigricans/drug therapy , Blood Glucose/analysis , Hyperinsulinism/drug therapy , Hypoglycemic Agents/therapeutic use , Metformin/therapeutic use , Acanthosis Nigricans/complications , Acanthosis Nigricans/pathology , Administration, Oral , Adolescent , Blood Glucose/drug effects , Glucose Clamp Technique , Glucose Tolerance Test , Humans , Hyperinsulinism/complications , Hypoglycemic Agents/administration & dosage , Male , Metformin/administration & dosage , Puberty/physiology
9.
Ann Thorac Surg ; 60(5): 1454-5, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8526658

ABSTRACT

Approximately 10% of all cases of Ewing's sarcoma arise from a rib. Conventional management has included chest wall resection (3 or more ribs) and radiation therapy. These forms of therapy have led to complications such as scoliosis and local deformity. The addition of radiation therapy can result in damage to the lung and adjacent viscera and also potentiate pulmonary restrictive disease. Between 1971 and 1978, 9 patients were treated with surgery, radiation therapy, and combination chemotherapy (three- or four-drug regimen). Only 2 patients (22%) survive. Since 1979, 14 patients were entered into a new protocol consisting of sequential induction chemotherapy, followed by delayed surgical resection whenever feasible. Three patients had complete resection of their primary lesion at onset. Initially, 7 patients had either biopsy (N = 4) or incomplete chest wall resection N = 3). All 4 patients with biopsy only at diagnosis had excellent responses to induction chemotherapy, allowing delayed resection of the involved rib without chest wall resection. Overall, 12 of 14 patients (86%) treated since 1979 survive, with only 2 receiving radiation therapy for residual disease in the primary rib site.


Subject(s)
Bone Neoplasms/history , Ribs , Sarcoma, Ewing/history , Bone Neoplasms/therapy , Combined Modality Therapy , Follow-Up Studies , History, 20th Century , Humans , Sarcoma, Ewing/therapy , Survival Analysis
10.
Med Pediatr Oncol ; 24(3): 176-80, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7838039

ABSTRACT

This prospective study was designed to estimate the response rates and to compare two drug pairs, cyclophosphamide/doxorubicin (Cy/A) and cisplatin/teniposide (P1/VM) in previously untreated patients with disseminated neuroblastoma > 12 months of age at diagnosis. Estimated complete clinical response rates after five courses of therapy were 13% (70 patients) and 22% (64 patients) for Cy/A and P1/VM, respectively (P = 0.17). After surgical removal of residual tumors in patients with partial response, the complete response rates were 27% and 34% (P = 0.50), respectively. The overall CR/PR rates after induction and surgery were 59% and 73% (P = 0.077). There was no significant difference in event free survival (P = 0.48) or survival (P = 0.40). Five year survival on the two arms were 14% (SE = 5%) and 12% (SE = 4%), respectively. Toxicity was significant but manageable. The Cy/A arm had significantly higher hematopoietic toxicity but significantly lower GI toxicity. Significant allergic reactions were seen with the P1/VM arm, none in the Cy/A arm. Given the activity of these two regimens, further therapy with a combination of these regimens is suggested.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neuroblastoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Child , Child, Preschool , Cisplatin/administration & dosage , Cisplatin/adverse effects , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Disease-Free Survival , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Humans , Infant , Neoplasm Metastasis , Neuroblastoma/mortality , Neuroblastoma/pathology , Prognosis , Prospective Studies , Remission Induction , Survival Rate , Teniposide/administration & dosage , Teniposide/adverse effects , United States
11.
J Clin Oncol ; 12(8): 1616-20, 1994 Aug.
Article in English | MEDLINE | ID: mdl-8040674

ABSTRACT

PURPOSE: Children less than 1 year of age with metastatic neuroblastoma NB are at high risk of death. The need to identify new and effective chemotherapy agents is clear. A study was conducted by the Pediatric Oncology Group (POG) to determine the efficacy and safety of administering two courses of a single phase II agent before conventional treatment as a means to evaluate new agents in this setting. PATIENTS AND METHODS: One hundred seventy-three eligible patients more than 1 year of age with disseminated neuroblastoma received two courses of one of the following: ifosfamide (IFOS) 2 g/m2/d for 4 days intravenously (IV) plus mesna; carboplatin (CARB) 560 mg/m2 i.v. over 1 hour; iproplatin (CHIP) 325 mg/m2 IV over 2 hours; or epirubicin (EPIR) 90 mg/m2 i.v. push. Following evaluation for response and toxicity, eligible patients were randomized to receive either cisplatin 90 mg/m2 i.v. on day 1, etoposide 200 mg/m2 i.v. on day 3, cyclophosphamide 150 mg/m2/d orally on days 7 to 13, doxorubicin 35 mg/m2 i.v. on day 14 (CECA), or cisplatin 40 mg/m2 IV on days 1 to 5 and etoposide 200 mg/m2 i.v. on days 2 to 4 alternating at 3-week intervals with cyclophosphamide 150 mg/m2/d orally on days 1 to 7 and doxorubicin 35 mg/m2 IV on day 8 (HDP/VP/CA). An additional 86 patients were randomized to receive either CECA or HDP/VP/CA without initial phase II therapy. RESULTS: After phase II therapy, only 20% of patients experienced grade 3/4 hematopoietic toxicity. No toxic deaths occurred. Objective response rates (partial responses [PRs] plus minor responses [MRs]) following IFOS, CARB, CHIP, and EPIR were 70%, 77%, 67%, and 26%, respectively. Following phase III treatment, there was no statistically significant difference in rates of complete response (CR)/PR or progressive disease (PD), or in time to PD of patients who participated in the phase II window versus those who received only CECA or HDP/VP/CA. CONCLUSION: IFOS, CARB, and CHIP are efficacious in neuroblastoma, are well tolerated, and should be incorporated into primary treatment regimens. Combination regimens using these agents may be possible, since most repeat courses were given within 2 weeks. Administering phase II therapy to untreated patients with high-risk tumors provides a unique and sensitive method to assess new agents without compromising patient outcome.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neuroblastoma/drug therapy , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carboplatin/administration & dosage , Child , Child, Preschool , Drug Administration Schedule , Epirubicin/administration & dosage , Female , Humans , Ifosfamide/administration & dosage , Infant , Male , Neuroblastoma/mortality , Neuroblastoma/pathology , Neutropenia/chemically induced , Organoplatinum Compounds/administration & dosage , Remission Induction
12.
Dig Dis Sci ; 37(2): 187-92, 1992 Feb.
Article in English | MEDLINE | ID: mdl-1735334

ABSTRACT

Intestinal dysmotility may be an important factor contributing to various gastrointestinal complications associated with cystic fibrosis. Motilin, enteroglucagon, neurotensin, and peptide YY may each play a role as endocrine hormones influencing gastrointestinal motor activity. Fasting children with cystic fibrosis (N = 8) and controls (N = 18) received a liquid nutrient test meal (fat 4 g/100 ml, protein 4 g/100 ml, carbohydrate 20 g/100 ml, 125 kcal/100 ml; 200 ml/m2) containing lactulose (5 g/100 ml), and the plasma concentrations of these peptides were studied. Mouth-to-cecum transit time was simultaneously studied using the breath H2 technique. Fasting levels of peptide YY and the postprandial response of all four peptides were significantly increased in those with cystic fibrosis. In repeat studies on those with cystic fibrosis after a period of altered pancreatic enzyme supplementation, no significant changes in peptide concentrations were observed. A rise in breath H2 permitting estimation of mouth-to-cecum transit time was noted in 17 control subjects (70-220 min, median 140). In contrast, a rise occurred in only two with cystic fibrosis after low-dose enzyme (70 and 180 min), and four after high-dose enzyme replacement (120-230 min, median 155). Altered gut hormone secretion may play a role in the pathophysiology of intestinal dysmotility in patients with cystic fibrosis.


Subject(s)
Cystic Fibrosis/blood , Hydrogen/analysis , Neuropeptides/blood , Adolescent , Breath Tests , Child , Cystic Fibrosis/physiopathology , Fasting/blood , Fasting/physiology , Food , Gastrointestinal Motility/physiology , Glucagon-Like Peptides/blood , Humans , Motilin/blood , Neurotensin/blood , Peptide YY , Peptides/blood
13.
Cancer ; 68(9): 1999-2006, 1991 Nov 01.
Article in English | MEDLINE | ID: mdl-1913549

ABSTRACT

The authors report the clinicopathologic and neuroimaging findings in ten children with primary abdominal or thoracic neuroblastoma who relapsed in the central nervous system (CNS) without evidence of concurrent intracranial extension from adjacent bone, dura, or dural sinus metastases. At diagnosis, the patients ranged in age from 0.3 to 4.5 years (median, 2 years). Their times to CNS relapse ranged from 2 to 34 months from diagnosis. In seven patients the relapse occurred from 1 to 14 months after elective discontinuation of therapy. In four patients, the CNS relapse was the primary (isolated) adverse event. Four patients could not be treated at the time of relapse, and they died within 7 days of progressive CNS disease. In the remaining group, craniospinal irradiation with or without administration of a platinum compound and an epipodophyllotoxin caused complete CNS remissions lasting 4, 5, 16, and 62+ months. Neuroimaging and autopsy findings indicated that cerebrospinal fluid is the major pathway for neuraxis dissemination by neuroblastoma cells. There was no evidence of dural penetration in any patient. The possibility of relapse in the neuraxis should be considered for any patient with neuroblastoma who had neurologic deterioration. A combination of craniospinal radiation and administration of a platinum compound and an epipodophyllotoxin will induce complete responses in some patients with neuraxis involvement by neuroblastoma, but the risk of subsequent failure outside the CNS remains high.


Subject(s)
Abdominal Neoplasms , Central Nervous System Neoplasms/secondary , Neuroblastoma/secondary , Thoracic Neoplasms , Abdominal Neoplasms/pathology , Antineoplastic Combined Chemotherapy Protocols , Central Nervous System Neoplasms/diagnostic imaging , Central Nervous System Neoplasms/pathology , Central Nervous System Neoplasms/therapy , Child, Preschool , Combined Modality Therapy , Cranial Irradiation , Diagnostic Imaging , Female , Humans , Infant , Magnetic Resonance Imaging , Male , Neoplasm Recurrence, Local , Neuroblastoma/diagnostic imaging , Neuroblastoma/pathology , Neuroblastoma/therapy , Remission Induction , Thoracic Neoplasms/pathology , Tomography, X-Ray Computed
14.
J Clin Oncol ; 9(9): 1599-608, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1831494

ABSTRACT

To gauge the impact of intensified therapy on the survival of infants (younger than 1 year, n = 129) and children (greater than or equal to 1 year of age, n = 275) with neuroblastoma, we analyzed the results of eight successive clinical trials comparing various combinations of antineoplastic drugs, surgery, and radiotherapy. Changes in treatment did not affect the survival of children with involved noncontiguous lymph nodes or distant metastatic disease until the combination of cisplatin and teniposide (CDDP/VM26) was added to a basic regimen of cyclophosphamide and doxorubicin (CTX/DOX). The resulting 4-year survival was 28% +/- 5% (SE) compared with 7% +/- 2% for previous treatments (P less than .001 by the log-rank test). The 4-year survival of infants with metastatic disease was improved by administering CTX/DOX to all patients, reserving CDDP/VM26 for those whose disease was resistant to the former combination: 82% +/- 6% versus 45% +/- 8% in earlier studies; P less than .001. In the subset of infants whose tumors had disseminated to bone or bone marrow at diagnosis, this therapeutic approach increased the probability of long-term survival from 48% +/- 10% to 85% +/- 9% (P = .01). The small group of children over 1 year of age with localized unresectable tumors also fared significantly better with the switch to CTX/DOX chemotherapy (4-year survival, 93% +/- 7% v 42% +/- 13%; P = .02). Multivariate analysis indicated that young age, limited-disease stage, nonadrenal primary site, and intensified treatment were independent predictors of a more favorable outcome. We conclude that substantial advances in the treatment of neuroblastoma have occurred over the past 25 years at this institution. The current overall 4-year survival probability of 57% +/- 4% compares favorably with estimates for most other common solid tumors of childhood.


Subject(s)
Neuroblastoma/therapy , Age Factors , Analysis of Variance , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Child , Child, Preschool , Combined Modality Therapy , Humans , Infant , Meta-Analysis as Topic , Neuroblastoma/mortality , Neuroblastoma/secondary , Prognosis , Survival Rate
16.
Cancer ; 65(3): 439-45, 1990 Feb 01.
Article in English | MEDLINE | ID: mdl-2297634

ABSTRACT

Seventy-six patients with classic high-grade osteosarcoma of an extremity received adjuvant chemotherapy by two protocols, initiated in 1972 and 1977, respectively, after appropriate amputations. Chemotherapy consisted of high-dose methotrexate, doxorubicin, and cyclophosphamide. Dose intensity of high-dose methotrexate and doxorubicin was greater for the patients treated with the protocol initiated in 1977. The proportion of long-term disease-free survivors on the two protocols are 46% and 56%. A better outcome (P = 0.042) was seen for the latter group, which received more intensive chemotherapy. Overall, metastases developed in 35 patients; in 19 who were receiving chemotherapy and in 16 after chemotherapy. The outcome for these two protocols, compared with two control groups that were given no chemotherapy or ineffective chemotherapy (biweekly vincristine and cyclophosphamide), confirms the results of controlled studies that showed an advantage of adjuvant chemotherapy after amputation for osteosarcoma.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bone Neoplasms/therapy , Extremities , Osteosarcoma/therapy , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bone Neoplasms/mortality , Bone Neoplasms/secondary , Child , Child, Preschool , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Lung Neoplasms/secondary , Male , Neoplasm Recurrence, Local , Osteosarcoma/mortality , Osteosarcoma/secondary , Prospective Studies , Thoracotomy
17.
J Clin Oncol ; 7(6): 754-60, 1989 Jun.
Article in English | MEDLINE | ID: mdl-2715805

ABSTRACT

One hundred seventy-seven children and young adults with various malignant neoplasms were prospectively tested for hearing loss after they had received cisplatin (n = 146), cranial irradiation (n = 18), or both (n = 13). Adequate renal function, no history of treatment with ototoxic drugs other than cisplatin, and availability for repeated audiometric testing were requirements for enrollment. Substantial hearing loss, defined as a hearing threshold of 50 dB or greater, was noted in only 11% of the cohort on tests conducted at the common speech frequencies (500 to 3,000 Hz). About half the patients had substantial deficits at higher frequencies (4,000 to 8,000 Hz). The probability of substantial hearing loss was directly related to the cumulative dose of cisplatin. In nonirradiated patients tested at the speech frequencies, there was a negligible risk of substantial deficits over the dose range of 90 to 360 mg/m2. As the dose increased to 720 mg/m2, the risk increased to 22%. In irradiated patients who later received cisplatin, cumulative drug doses as low as 270 mg/m2 were associated with a high probability of substantial hearing loss, suggesting potentiation of ototoxicity when these therapies are used together. Hearing acuity was either not affected or only minimally decreased in the irradiation-only group. Younger age, prior irradiation, and the presence of a CNS tumor each contributed significantly to the severity of hearing deficits at given cisplatin dose levels. We conclude that early increases in hearing threshold at a stimulus frequency of 4,000 Hz indicate probable subsequent deficits at lower frequencies, especially in young children with CNS tumors who have received cranial irradiation. The probability charts derived from this analysis should provide a useful tool for predicting hearing loss in the speech frequencies.


Subject(s)
Cisplatin/adverse effects , Hearing Loss/etiology , Neoplasms/drug therapy , Adolescent , Adult , Age Factors , Child , Child, Preschool , Cisplatin/administration & dosage , Cohort Studies , Hearing/drug effects , Hearing/radiation effects , Hearing Tests , Humans , Infant , Neoplasms/radiotherapy , Probability , Prospective Studies
18.
Cancer ; 63(6): 1211-4, 1989 Mar 15.
Article in English | MEDLINE | ID: mdl-2917322

ABSTRACT

Ganglioneuroma may occur spontaneously or after therapy for neuroblastoma. This lesion may be metastatic or unresectable in the primary site. The rarity of this situation and lack of understanding of the biology of this benign condition may lead to extensive, potentially life-threatening attempts at surgical resection or the futile use of chemotherapy or radiotherapy to try to cause regression or control growth. The authors present here several cases which demonstrate the multiple presentations of ganglioneuroma and the potential problems which may arise in their management.


Subject(s)
Cell Transformation, Neoplastic/pathology , Ganglioneuroma/pathology , Neuroblastoma/pathology , Abdominal Neoplasms/pathology , Bone Neoplasms/pathology , Child , Child, Preschool , Female , Ganglioneuroma/secondary , Ganglioneuroma/therapy , Humans , Infant , Infant, Newborn , Maxillary Neoplasms/pathology , Neuroblastoma/secondary , Neuroblastoma/therapy , Pelvic Neoplasms/pathology
19.
Semin Oncol ; 16(1 Suppl 3): 51-5, 1989 Feb.
Article in English | MEDLINE | ID: mdl-2495567

ABSTRACT

A phase-II study of ifosfamide with mesna, given intravenously daily for five days by bolus injection, has demonstrated the activity of ifosfamide against a spectrum of childhood malignant solid tumors. Ifosfamide presently is being investigated in alternative phase-I schedules, daily times three or every other day times three with the aim of delivering comparable amounts of ifosfamide without increasing toxicity--specifically, neurotoxicity. Additionally, response following ifosfamide treatment is being evaluated for previously untreated children with osteosarcoma and rhabdomyosarcoma after 6 weeks of treatment, and for previously untreated patients with Ewing's sarcoma after 9 weeks of treatment with ifosfamide/VP-16 (etoposide) given in combination.


Subject(s)
Ifosfamide/therapeutic use , Mercaptoethanol/analogs & derivatives , Mesna/administration & dosage , Neoplasms/drug therapy , Adolescent , Child , Child, Preschool , Drug Evaluation , Humans , Ifosfamide/adverse effects , Infant , Remission Induction , Sarcoma/drug therapy
20.
Cancer Chemother Pharmacol ; 24 Suppl 1: S24-7, 1989.
Article in English | MEDLINE | ID: mdl-2503257

ABSTRACT

Ifosfamide/mesna was given to 97 patients who had malignant solid tumors diagnosed before they were 21 years of age. Patients received 1.6 g/m2 ifosfamide daily x 5, given i.v. over 15 min, followed by 400 mg/m2 i.v. mesna at 15 min and 4 and 6 h after ifosfamide. Responses were noted in patients with osteosarcoma, Ewing's sarcoma, rhabdomyosarcoma and other soft-tissue sarcomas, rhabdoid tumor, neuroblastoma, Wilms' tumor, primitive neuroectodermal tumor, retinoblastoma, germ-cell tumors, and B-cell lymphoma. Toxicity included mild to moderate nausea and vomiting, transient, reversible myelosuppression, transient elevations of serum blood urea nitrogen (BUN) and creatinine and liver enzymes, infections, and self-limiting neurotoxicity characterized by changes in mental status, motor dysfunction, cranial nerve palsy, cerebellar dysfunction, and seizures. Neurotoxic symptoms were generally seen in patients who had previously received cisplatin. Ifosfamide is an important alkylating agent that should be combined with other agents in phase II and III trials. Alternate dose schedules should also be investigated.


Subject(s)
Ifosfamide/therapeutic use , Neoplasms/drug therapy , Adolescent , Child , Child, Preschool , Drug Evaluation , Drug Therapy, Combination , Humans , Ifosfamide/adverse effects , Infant , Infusions, Intravenous , Mesna/administration & dosage , Remission Induction , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...