Amendment the surface structure and optical properties of Makrofol LT by low energy oxygen ion bombardment.

Ion beam bombardment is a powerful technique to improve the surface properties of polymeric materials without changing the bulk properties. Herein, Makrofol LT films were bombarded with low energy of oxygen ions at different fluences ranging from 11 × 1017 to 44 × 1017 ions/cm2. X-ray diffraction, FTIR spectroscopy, surface-roughness tester, ultraviolet-visible spectroscopy, and Fluorescence spectroscopy were used to examine the change in the structure, chemical functional groups, alteration in surface roughness parameters, and photo-physical properties. The obtained results evidenced that the ordering and disordering structure of bombarded Makrofol LT films were influenced by ion beam irradiation according to the ion fluence. The FTIR spectroscopy of functional group examination revealed the possibility of the presence of sp2-carbon clusterization and amorphization. The surface roughness parameters increase as the ion fluences increase. Optical measurements exhibit a shift of absorption-edge towards the visible zone that correlated to the surface damage and the creation of CC bonds. The fluorescence spectra exhibit that the yield intensities decrease with increasing ion fluences. This refers to improvement in the radiative-recombination rate relative to non-radiative recombination. This is attributable to the growth of clusters, the increase of density states of the surface, and the increase in the surface roughness of the bombarded samples.

Malignant fibrous histiocytoma and other fibrohistiocytic tumors in pediatric patients: the St. Jude Children's Research Hospital experience.

BACKGROUND: Malignant fibrous histiocytoma (MFH) is a controversial entity. In the current study, the authors reviewed their institutional experience with these tumors to characterize their clinical features in pediatric patients and assess the impact of surgical resection on outcome. METHODS: The records of the 28 patients who were diagnosed with MFH or MFH variants of soft tissue between January 1971 and December 2000 were reviewed and the tumors were reclassified according to the World Health Organization guidelines. RESULTS: Seventeen patients had MFH; 10 patients had angiomatoid fibrous histiocytoma (FH), and 1 patient had a plexiform fibrohistiocytic tumor. The median age of patients at the time of diagnosis was 7.3 years. The most common primary tumor site was the extremity (n = 14). Metastatic disease (to the lung) was present in only three patients, each of whom had MFH. Of the 17 MFH tumors, 13 were high grade, 8 were invasive, and 6 measured > 5 cm. All angiomatoid FH tumors and the plexiform fibrohistiocytic tumor were noninvasive, and 10 measured < or = 5 cm. Surgical treatment was comprised of wide local excision with clear margins (n = 18), amputation (n = 3), excision with positive or indeterminate surgical margins (n = 4), partial resection (n = 2), or biopsy only (n = 1). Primary reexcision was performed for 21 patients. The 5-year survival and event-free survival (EFS) estimates for patients with MFH were 76.5% +/- 11.2% and 70.6% +/- 12.1%, respectively; the 5-year survival and EFS estimates were 100% +/- 0% for patients with angiomatoid FH or plexiform fibrohistiocytic tumor. Compared with partial resection or excision, wide local excision or amputation was found to have a positive impact on the probability of EFS in patients with localized disease (P = 0.008). All four patients with metastatic or unresectable MFH had died by the time of last follow-up. CONCLUSIONS: MFH should be distinguished from angiomatoid FH and plexiform fibrohistiocytic tumors, both of which are less aggressive. Wide local excision is the treatment of choice, regardless of the histology or grade of the tumor. Patients with metastatic or unresectable MFH appear to have a poor outcome and would benefit from more effective therapies.

Pharmacokinetics and pharmacodynamics of oral etoposide in children with relapsed or refractory acute lymphoblastic leukemia.

PURPOSE: To study the pharmacokinetics and pharmacodynamics of once- versus twice-daily oral etoposide in children with relapsed or refractory acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Fifty-eight patients were randomly assigned to etoposide at 50 mg/m(2)/d with once- versus twice-daily doses for 22 days. On day 8, vincristine, asparaginase, and dexamethasone were started. Etoposide pharmacokinetics and pharmacodynamics were studied for 47, 28, and 26 patients on day 1, 8, and 22, respectively, of remission reinduction therapy. RESULTS: Of 48 patients with pharmacokinetic data, 42 (87.5%) achieved complete remission, three (6.3%) failed to achieve remission, and three (6.3%) died during induction. Median etoposide day 8 area under concentration-time curve (AUC) and cumulative AUC tended to be greater (P =.06 and P =.07, respectively) in patients (n = 23) who achieved complete remission (24 and 522 micro mol/L x h, respectively) than in patients (n = 3) who did not (14 and 303 micro mol/L x h, respectively). Three of eight patients with plasma concentrations exceeding 1.7 micro M (1 micro g/mL) for more than 8 hours daily, compared with one of 20 patients with concentrations exceeding 1.7 micro M for