8 research outputs found
Practitioners Speak Out
The agricultural economy of Iowa is undergoing rapid changes. The trend seems to be toward larger economic units and more specialization. The livelihood of the large animal practitioner is dependent on the economics of the agricultural community. Being concerned with the role of the large animal practitioner in the agri-business industry of Iowa, it was decided to send out a questionnaire to various practitioners in the state
A Canadian paediatric brain tumour consortium (CPBTC) phase II molecularly targeted study of imatinib in recurrent and refractory paediatric central nervous system tumours
PURPOSE:
To evaluate the safety, efficacy and pharmacokinetics of imatinib in children with recurrent or refractory central nervous system (CNS) tumours expressing KIT and/or PDGFRA.
METHODS:
Nineteen patients aged 2-18 years, with recurrent or refractory CNS tumours expressing either of the target receptors KIT and/or PDGFRA (by immunohistochemistry) were eligible. Participants received imatinib orally at a dose of 440 mg/m(2)/day and toxicities and tumour responses were monitored. Serial blood and cerebrospinal fluid samples for pharmacokinetics were obtained in a subset of consenting patients. Frozen tumour samples were analysed retrospectively for KIT and PDGFRA gene amplification in a subset of patients for whom samples were available.
RESULTS:
Common toxicities were lymphopaenia, neutropaenia, leucopaenia, elevated serum transaminases and vomiting. No intratumoural haemorrhages were observed. Although there were no objective responses to imatinib, four patients had long-term stable disease (SD) (38-104 weeks). Our results suggest a possible relationship between KIT expression and maintenance of SD with imatinib treatment; KIT immunopositivity was seen in only 58% (11/19) of study participants overall, but in 100% of patients with SD at 38 weeks. All patient tumours showed PDGFRA expression. Pharmacokinetic data showed a high interpatient variability, but corresponded with previously reported values.
CONCLUSIONS:
Imatinib at 440 mg/m(2)/day is relatively safe in children with recurrent CNS tumours, but induced no objective responses. Demonstration of SD in previously progressing patients (KIT-expressing) suggests cytostatic activity of imatinib.info:eu-repo/semantics/publishedVersio
Practitioners Speak Out
The agricultural economy of Iowa is undergoing rapid changes. The trend seems to be toward larger economic units and more specialization. The livelihood of the large animal practitioner is dependent on the economics of the agricultural community. Being concerned with the role of the large animal practitioner in the agri-business industry of Iowa, it was decided to send out a questionnaire to various practitioners in the state.</p
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Soluble Epoxide Hydrolase Derived Linoleic Acid Oxylipins, Small Vessel Disease Markers, and Neurodegeneration in Stroke
Background Cerebral small vessel disease is associated with higher ratios of soluble-epoxide hydrolase derived linoleic acid diols (12,13-dihydroxyoctadecenoic acid [DiHOME] and 9,10-DiHOME) to their parent epoxides (12(13)-epoxyoctadecenoic acid [EpOME] and 9(10)-EpOME); however, the relationship has not yet been examined in stroke. Methods and Results Participants with mild to moderate small vessel stroke or large vessel stroke were selected based on clinical and imaging criteria. Metabolites were quantified by ultra-high-performance liquid chromatography-mass spectrometry. Volumes of stroke, lacunes, white matter hyperintensities, magnetic resonance imaging visible perivascular spaces, and free water diffusion were quantified from structural and diffusion magnetic resonance imaging (3 Tesla). Adjusted linear regression models were used for analysis. Compared with participants with large vessel stroke (n=30), participants with small vessel stroke (n=50) had a higher 12,13-DiHOME/12(13)-EpOME ratio (β=0.251, P=0.023). The 12,13-DiHOME/12(13)-EpOME ratio was associated with more lacunes (β=0.266, P=0.028) but not with large vessel stroke volumes. Ratios of 12,13-DiHOME/12(13)-EpOME and 9,10-DiHOME/9(10)-EpOME were associated with greater volumes of white matter hyperintensities (β=0.364, P<0.001; β=0.362, P<0.001) and white matter MRI-visible perivascular spaces (β=0.302, P=0.011; β=0.314, P=0.006). In small vessel stroke, the 12,13-DiHOME/12(13)-EpOME ratio was associated with higher white matter free water diffusion (β=0.439, P=0.016), which was specific to the temporal lobe in exploratory regional analyses. The 9,10-DiHOME/9(10)-EpOME ratio was associated with temporal lobe atrophy (β=-0.277, P=0.031). Conclusions Linoleic acid markers of cytochrome P450/soluble-epoxide hydrolase activity were associated with small versus large vessel stroke, with small vessel disease markers consistent with blood brain barrier and neurovascular-glial disruption, and temporal lobe atrophy. The findings may indicate a novel modifiable risk factor for small vessel disease and related neurodegeneration
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Integrated (epi)-Genomic Analyses Identify Subgroup-Specific Therapeutic Targets in CNS Rhabdoid Tumors
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype
Integrated (epi)-Genomic Analyses Identify Subgroup-Specific Therapeutic Targets in CNS Rhabdoid Tumors
We recently reported that atypical teratoid rhabdoid tumors (ATRTs) comprise at least two transcriptional subtypes with different clinical outcomes; however, the mechanisms underlying therapeutic heterogeneity remained unclear. In this study, we analyzed 191 primary ATRTs and 10 ATRT cell lines to define the genomic and epigenomic landscape of ATRTs and identify subgroup-specific therapeutic targets. We found ATRTs segregated into three epigenetic subgroups with distinct genomic profiles, SMARCB1 genotypes, and chromatin landscape that correlated with differential cellular responses to a panel of signaling and epigenetic inhibitors. Significantly, we discovered that differential methylation of a PDGFRB-associated enhancer confers specific sensitivity of group 2 ATRT cells to dasatinib and nilotinib, and suggest that these are promising therapies for this highly lethal ATRT subtype