ABSTRACT
The ring-stage susceptibility assay was modified to quantify the susceptibilities of multiple strains of control and delayed-clearance phenotype (DCP) Plasmodium falciparum strains to seven endoperoxide antimalarial drugs. The susceptibility of all of the DCP lines to six of the drugs was lower than that of the controls. In contrast, DCP parasites did not show reduced susceptibility to the synthetic endoperoxide drug OZ439. These data show that it is possible to circumvent emerging artemisinin resistance with a modified endoperoxide drug.
Subject(s)
Antimalarials/pharmacology , Artemisinins/pharmacology , Drug Resistance/drug effects , Plasmodium falciparum/drug effects , Adamantane/analogs & derivatives , Adamantane/pharmacokinetics , Adamantane/pharmacology , Antimalarials/administration & dosage , Antimalarials/pharmacokinetics , Artemether , Artemisinins/administration & dosage , Artemisinins/pharmacokinetics , Dose-Response Relationship, Drug , Heterocyclic Compounds, 1-Ring/administration & dosage , Heterocyclic Compounds, 1-Ring/pharmacokinetics , Heterocyclic Compounds, 1-Ring/pharmacology , Inactivation, Metabolic , Lethal Dose 50 , Microbial Sensitivity Tests , Peroxides/administration & dosage , Peroxides/pharmacokinetics , Peroxides/pharmacology , Spiro Compounds/administration & dosage , Spiro Compounds/pharmacokinetics , Spiro Compounds/pharmacologyABSTRACT
BACKGROUND: Current data on the use of irreversible electroporation (IRE) in the treatment of prostate cancer (PCa) is limited. We aim to evaluate the safety, short-term functional and oncological outcomes of focal IRE in low-intermediate risk PCa. METHODS: Between February 2013 and May 2014, 32 consecutive men underwent IRE at a single centre. Patients with low-intermediate risk PCa who had not received previous PCa treatment were included for analysis. The tumour was ablated using 3-6 electrodes, ensuring a minimum 5-mm safety margin around the visible magnetic resonance imaging (MRI) lesion. Follow-up included recording Clavien complications, Expanded Prostate Cancer Index Composite (EPIC) questionnaires (baseline, 1.5, 3, 6 months), 6-month multi-parametric MRI (mp-MRI) and 7-month biopsy. Findings on mp-MRI and biopsy were sub-divided into infield, adjacent or outfield of the treatment zone. RESULTS: Twenty-five men were included for final analysis. Safety follow-up revealed one Clavien Grade 3 complication and five Grade 1 complications. Functional follow-up confirmed no significant change in American Urological Association urinary symptom score, sexual or bowel function. Infield, there were no suspicious findings on mp-MRI (n=24) or biopsy (n=21) in all patients. Adjacent to the treatment zone, five (21%) had suspicious findings on mp-MRI with four (19%) proving to be significant on biopsy. Outfield, there were two (8%) with suspicious findings on mp-MRI and one (5%) significant finding on biopsy. For the five patients with significant findings on follow-up biopsy, one is awaiting repeat IRE, one had radical prostatectomy and three remained on active surveillance. CONCLUSIONS: In selected patients with low-intermediate risk PCa, focal IRE appears to be safe with minimal morbidity. There were no infield recurrences and 76% of patients were histologically free of significant cancer at 8 months. Almost all recurrences were adjacent to the treatment zone, and this was addressed by widening the treatment margins.
