Preservation of endocrine function after Ommaya reservoir insertion in children with cystic craniopharyngioma.

INTRODUCTION: Children with craniopharyngiomas (CP) can experience significant morbidities caused by extensive surgery and/or radiation. Ommaya reservoir insertion (ORI) into cystic CP represents a minimally invasive approach allowing immediate decompression and aims to avoid additional injuries. The purpose of this study was to determine the surgical outcome and relevance of upfront ORI (± intracystic treatment) for preservation of endocrine function. METHODS: We performed a retrospective chart review of children with CP treated at the Hospital for Sick Children between 01/01/2000 and 15/01/2020. Endocrine function was reviewed at the time of initial surgery and throughout follow-up. New endocrinological deficits related to the index procedure were defined as immediate failure (IF), whereas postoperative duration of endocrinological stability (ES) was analyzed using the Kaplan-Meier method. The rate of IF and ES was compared between the treatment groups. RESULTS: Seventy-nine patients were included and had a median age of 8.3 years (range 2.1-18.0 years); 31 were males. Fifty-three patients with upfront surgical treatment, including 29 ORI and 24 gross total or partial resections had sufficient endocrinological follow-up data. Endocrine dysfunction occurring immediately after the index procedure (IF) was observed in 15 patients (62.5%) in the resection group compared to two patients (6.8%) in the ORI group, odds ratio: 0.05 (CI: 0.01-0.26, p < 0.0001). Excluding those with immediate endocrinological deficits, mean ES after ORI was 19.4 months (CI: 11.6-34.2), compared to 13.4 months (CI:10.6-NA) after surgical resection. CONCLUSIONS: Endocrine function was preserved in patients with upfront ORI (± intracystic treatment), which was confirmed as a minimally invasive procedure with an overall low morbidity profile.

Rare Presentation of Supratentorial Primitive Neuroectodermal Tumors Mimicking Bifocal Germ Cell Tumors: 2 Case Reports.

Bifocal pineal and suprasellar tumors have only been described in the context of germ cell tumors in the pediatric age group. We report 2 patients with radiologic findings of bifocal pineal and suprasellar lesions, with a histologic diagnosis of supratentorial primitive neuroectodermal tumor. The absence of diabetes insipidus and other endocrine abnormalities was noteworthy in both cases. This observation challenges previous reports on the pathognomonic value of this clinico-radiologic entity.

Survival benefit for pediatric patients with recurrent ependymoma treated with reirradiation.

PURPOSE: The outcome of recurrent ependymoma in children is dismal. Reirradiation has been proposed as an effective modality for ependymoma at relapse. However, the toxicity and outcome benefits of this approach have not been well established. METHODS AND MATERIALS: We conducted a retrospective population-based study of all patients with recurrent ependymoma treated between 1986 and 2010 in our institution. Demographic, treatment, and outcome data were analyzed for the entire cohort. RESULTS: Of 113 patients with intracranial ependymoma, 47 patients relapsed. At the time of relapse, 29 patients were treated with surgical resection and/or chemotherapy, and 18 patients received full-dose (≥ 54 Gy focal and/or craniospinal) reirradiation with or without surgery at recurrence. Reirradiation was tolerated well with no severe acute complications noticed. Three-year overall survival was 7% ± 6% and 81% ± 12% for nonreirradiated and reirradiated patients, respectively (p < 0.0001). Time to second progression after reirradiation was significantly longer than time to first progression. This surprising phenomenon was associated with improved progression-free survival for tumors with evidence of DNA damage (n = 15; p = 0.002). At a mean follow-up of 3.73 years, only 2/18 patients had endocrine dysfunction, and 1 patient required special education support. However, a decline in intellectual function from pre- to postreirradiation assessment was observed. CONCLUSIONS: Reirradiation is an effective treatment that may change the natural history of recurrent ependymoma in children. However, this change may be associated with increased neurocognitive toxicity. Additional follow-up is needed to determine the risk of late recurrence, secondary radiation-induced tumors, and long-term functional outcome of these patients.

Analysis of long-chain polyprenols using supercritical fluid chromatography and matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

The separation of long-chain polyprenols was successfully achieved using supercritical fluid chromatography (SFC). Each 100-mer greater component was separated using tetrahydrofuran as a mobile phase modifier. The molecular mass distributions derived from SFC analyses agreed with the results of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses. The number-average molecular mass calculated by MALDI-TOF-MS data were also in accord with the results of quantitative 1H-NMR analysis of terminal groups. A combination of SFC and MALDI-TOF-MS analyses is a powerful tool for the elucidation of the complicated structures of natural polyprenols.

The occurrence of geometric polyprenol isomers in the rubber-producing plant, Eucommia ulmoides Oliver.

The chain length and geometric isomerism of polyprenols from Eucommia ulmoides Oliver were analyzed using supercritical fluid chromatography. After intensive effort to establish separation conditions for geometric isomers, a phenyl-bonded silica gel-packed column was found that cleanly separated poly-trans and -cis prenols. The presence of long-chain poly-trans prenols (>9 mers) was confirmed for the first time in plants. Trans isomers were found in the leaf, seed coat, and root, but not in the bark and seed. Poly-trans prenols in this plant may act as intermediates for trans-polyisoprene biosynthesis.

High-resolution analysis of polyprenols by supercritical fluid chromatography.

A high-resolution analysis of polyprenol mixtures was achieved by supercritical fluid chromatography (SFC). The separation of polyprenols was examined on an octadecylsilane-packed column with liquid carbon dioxide as the mobile phase and ethanol as modifier. Using this chromatography system, the resolution of separation (Rs) between octadecaprenol (prenol 18) and nonadecaprenol (prenol 19) was two times higher than that using conventional reversed-phase high-performance liquid chromatography. Our SFC technique allows the advantage of baseline separation of polyprenol samples containing hydrophobic components such as terpenes or fatty acids that are unfavorable for good separation. This method is very useful for the analysis of structurally close polyprenol analogues of rubber plant metabolites.

Analysis of poly(ethyl methacrylate)s by on-line hyphenation of liquid chromatography at the critical adsorption point and nuclear magnetic resonance spectroscopy

Liquid chromatography at the critical adsorption point (LC CAP) with on-line NMR detection (on-line LC CAP NMR) was utilized for analysis of tacticity distribution of stereo-regular poly(ethyl methacrylate)s (PEMAs). The separation of a model PEMA sample composed of four constituents with similar molar masses (Mw = (14-16) x 10(3) g mol-1) differing in their tacticity (rr triad content = 0, 33, 68, and 89%) was achieved by LC CAP with a mixed eluent composed of acetone, acetone-d6, and cyclohexane. The tacticity composition within each peak eluted from the LC CAP column was directly determined by a 750-MHz 1H NMR spectrometer that was used as a real-time detector in the continuous-flow mode. Tacticity distribution in a particular PEMA sample with mm/mr/rr = 2/45/53 and narrow molar mass distribution of Mw/Mn = 1.05 has been revealed by the LC CAP NMR technique.

The fundamentals of applying electrospray ionization mass spectrometry to low mass poly(methyl methacrylate) polymers.

Electrospray ionization (ESI) is capable of ionizing many soluble polymers. The ESI spectra are complex because of overlap of the multiply charged ions of the oligomer distribution, causing current computer transform programs to fail. However, it is possible to determine the origin of the multiply charged ions, making it feasible to write a program designed to transform ESI polymer spectra. To assess the value of such a program for polymer analysis, isolated monodisperse methyl methacrylate (MMA) oligomers (25 and 50 repeat units) were used to determine molar signal response and propensity for fragmentation.The sum of the peak areas for the multiply charged MMA 50-mer was found to be only about 66% of the summed peak areas for the 25-mer for the same molar concentration. However, conversion of the multiply charged peak areas to the singly charged representations, with peak area compression taken into account, gave equal signal responses for the 25-and 50-mers. Signal response variations due to the tacticity of the MMA oligomers were not observed. Fragmentation of the MMA oligomers also was shown not to occur under normal ESI conditions. Therefore, transformation of the polymer spectra to the singly charged molecular ion distribution should allow accurate calculation of average molecular weights, polydispersity, end group mass, and repeat unit mass.