140 research outputs found

    The formation of [M–H]+ ions in N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione derivatives during atmospheric pressure photoionization mass spectrometry

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    RATIONALE The formation of ions during atmospheric pressure photoionization (APPI) mass spectrometry in the positive mode usually provides radical cations and/or protonated species. Intriguingly, during the analysis of some N-alkyl-substituted thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives synthesized in our laboratory, unusual [M–H]+ ion peaks were observed. In this work we investigate the formation of [M–H]+ ions observed under APPI conditions. METHODS Multiple experimental parameters, including the type of ionization source, the composition of the solvent, the type of dopant, the infusion flow rate, and the length of the alkyl side chain were investigated to determine their effects on the formation of [M–H]+ ions. In addition, a comparison study of the gas-phase tandem mass spectrometric (MS/MS) fragmentation of [M + H]+ vs [M–H]+ ions and computational approaches were used. RESULTS [M–H]+ ions were observed under APPI conditions. The type of dopant and the length of the alkyl chain affected the formation of these ions. MS/MS fragmentation of [M–H]+ and [M + H]+ ions exhibited completely different patterns. Theoretical calculations revealed that the loss of hydrogen molecules from the [M + H]+ ions is the most favourable condition under which to form [M–H]+ ions. CONCLUSIONS [M–H]+ ions were detected in all the TPD derivatives studied here under the special experimental conditions during APPI, using a halogenated benzene dopant, and TPD containing substituted N-alkyl side chains with a minimum of four carbon atoms. Density functional theory calculations showed that for [M–H]+ ions to be formed under these conditions, the loss of hydrogen molecules from the [M + H]+ ions is proposed to be necessary

    Comparison of DC Bead-irinotecan and DC Bead-topotecan drug eluting beads for use in locoregional drug delivery to treat pancreatic cancer

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    DC Bead is a drug delivery embolisation system that can be loaded with doxorubicin or irinotecan for the treatment of a variety of liver cancers. In this study we demonstrate that the topoisomerase I inhibitor topotecan hydrochloride can be successfully loaded into the DC Bead sulfonate-modified polyvinyl alcohol hydrogel matrix, resulting in a sustained-release drug eluting bead (DEBTOP) useful for therapeutic purposes. The in vitro drug loading capacity, elution characteristics and the effects on mechanical properties of the beads are described with reference to our previous work with irinotecan hydrochloride (DEBIRI). Results showed that drug loading was faster when the solution was agitated compared to static loading and a maximum loading of ca. 40–45 mg topotecan in 1 ml hydrated beads was achievable. Loading the drug into the beads altered the size, compressibility moduli and colour of the bead. Elution was shown to be reliant on the presence of ions to perform the necessary exchange with the electrostatically bound topotecan molecules. Topotecan was shown by MTS assay to have an IC50 for human pancreatic adenocarcinoma cells (PSN-1) of 0.22 and 0.27 lM compared to 28.1 and 19.2 lM for irinotecan at 48 and 72 h, respectively. The cytotoxic efficacy of DEBTOP on PSN-1 was compared to DEBIRI. DEPTOP loaded at 6 & 30 mg ml-1, like its free drug form, was shown to be more potent than DEBIRI of comparable doses at 24, 48 & 72 h using a slightly modified MTS assay. Using a PSN-1 mouse xenograft model, DEBIRI doses of 3.3–6.6 mg were shown to be well tolerated (even with repeat administration) and effective in reducing the tumour size. DEBTOP however, was lethal after 6 days at doses of 0.83–1.2 mg but demonstrated reasonable efficacy and tolerability (again with repeat injection possible) at 0.2–0.4 mg doses. Care must therefore be taken when selecting the dose of topotecan to be loaded into DC Bead given its greater potency and potential toxicity

    European Organization for Research and Treatment of Cancer (EORTC) open label phase II study on glufosfamide administered as a 60-minute infusion every 3 weeks in recurrent glioblastoma multiforme

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    Background: Glufosfamide is a new alkylating agent in which the active metabolite of isophosphoramide mustard is covalently linked to β-d-glucose to target the glucose transporter system and increase intracellular uptake in tumor cells. We investigated this drug in a multicenter prospective phase II trial in recurrent glioblastoma multiforme (GBM). Patients and methods: Eligible patients had recurrent GBM following surgery, radiotherapy and no more than one prior line of chemotherapy. Patients were treated with glufosfamide 5000 mg/m2 administered as a 1-h intravenous infusion. Treatment success was defined as patients with either an objective response according to Macdonald's criteria or 6 months progression-free survival. Toxicity was assessed with the Common Toxicity Criteria (CTC) version 2.0. Results: Thirty-one eligible patients were included. Toxicity was modest, the main clinically relevant toxicities being leukopenia (CTC grade >3 in five patients) and hepatotoxicity (in three patients). No responses were observed; one patient (3%; 95% confidence interval 0 to 17%) was free from progression at 6 months. Pharmacokinetic analysis showed a 15% decrease in area under the curve and glufosfamide clearance in patients treated with enzyme-inducing antiepileptic drugs, but no effect of these drugs on maximum concentration and plasma half-life. Conclusion: Glufosfamide did not show significant clinical antitumor activity in patients with recurrent GB

    Orthopaedic health status of horses from 8 riding schools - a pilot study

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    <p>Abstract</p> <p>Background</p> <p>Orthopaedic injury is the most common reason for lameness and wastage in sport and leisure horses. Studies on racehorses have shown differences in injury risk between trainers and training strategies. The aim was to study between riding school variation in orthopaedic health status by clinical examination and horses age, and control for change of examiner, in schools with previous high (n = 4) and low (n = 4) insurance utilisation.</p> <p>Methods</p> <p>Horses (n = 99) at 8 riding schools were examined for conformation, movement in all gaits, standing flexion tests and palpation by two veterinary surgeons (in some schools only one). Indexes of findings were created for total health, movements, limbs, conformation and back palpation.</p> <p>Results</p> <p>Logistic regression analyses showed that findings increased with age (walk, trot, canter, conformation left hind limb, palpation fore limbs, hooves and flexion tests) or decreased with age (conformation right fore limb). Significant differences in findings were found between riding schools and examiner for seven and eight criteria each (partly overlapping). Increasing indexes were significantly associated with one examiner (total health, movements, back palpation), increasing age (total health, movements) or more time at the school (limbs). The back palpation index was highest at 5 < 8 years since acquisition.</p> <p>Conclusion</p> <p>The age distribution differed markedly between riding schools and age affected several types of findings. This, combined with the two opposite groups of insurance use, shows that schools with low insurance utilisation had previously been able to "avoid" using the insurance, maybe even on similar types of cases if these were more promptly/differently handled indicating differential coverage of disease data in the insurance database. The examiner effect was clearly demonstrated. For some findings, the amount of clinical observations differed by school, even when examiner and age was adjusted for. Most findings were of minor importance, including slight movement irregularities. Orthopaedic status varies between riding schools. We hypothesize that this is associated with management factors that warrant further study.</p

    European Organization for Research and Treatment of Cancer (EORTC) open label phase II study on glufosfamide administered as a 60-minute infusion every 3 weeks in recurrent glioblastoma multiforme

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    BACKGROUND: Glufosfamide is a new alkylating agent in which the active metabolite of isophosphoramide mustard is covalently linked to beta-D-glucose to target the glucose transporter system and increase intracellular uptake in tumor cells. We investigated this drug in a multicenter prospective phase II trial in recurrent glioblastoma multiforme (GBM). PATIENTS AND METHODS: Eligible patients had recurrent GBM following surgery, radiotherapy and no more than one prior line of chemotherapy. Patients were treated with glufosfamide 5000 mg/m(2) administered as a 1-h intravenous infusion. Treatment success was defined as patients with either an objective response according to Macdonald's criteria or 6 months progression-free survival. Toxicity was assessed with the Common Toxicity Criteria (CTC) version 2.0. RESULTS: Thirty-one eligible patients were included. Toxicity was modest, the main clinically relevant toxicities being leukopenia (CTC grade >3 in five patients) and hepatotoxicity (in three patients). No responses were observed; one patient (3%; 95% confidence interval 0 to 17%) was free from progression at 6 months. Pharmacokinetic analysis showed a 15% decrease in area under the curve and glufosfamide clearance in patients treated with enzyme-inducing antiepileptic drugs, but no effect of these drugs on maximum concentration and plasma half-life. CONCLUSION: Glufosfamide did not show significant clinical antitumor activity in patients with recurrent GBM

    First-line, fixed-duration nivolumab plus ipilimumab followed by nivolumab in clinically diverse patient populations with unresectable stage III or IV melanoma: Checkmate 401

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    PURPOSE: To address the paucity of data in patients with historically poor outcomes, we conducted the single-arm phase IIIb CheckMate 401 study to evaluate the safety and efficacy of nivolumab plus ipilimumab followed by nivolumab monotherapy in clinically diverse patient populations with advanced melanoma. METHODS: Treatment-naive patients with unresectable stage III-IV melanoma received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks (four doses) followed by nivolumab 3 mg/kg (240 mg following a protocol amendment) once every 2 weeks for ≤ 24 months. The primary end point was the incidence of grade 3-5 select treatment-related adverse events (TRAEs). Overall survival (OS) was a secondary end point. Outcomes were evaluated in subgroups defined by Eastern Cooperative Oncology Group performance status (ECOG PS), brain metastasis status, and melanoma subtype. RESULTS: In total, 533 patients received at least one dose of study drug. Grade 3-5 select TRAEs affecting the GI (16%), hepatic (15%), endocrine (11%), skin (7%), renal (2%), and pulmonary (1%) systems occurred in the all-treated population; similar incidence rates were observed across all subgroups. At 21.6 months\u27 median follow-up, 24-month OS rates were 63% in the all-treated population, 44% in the ECOG PS 2 subgroup (including patients with cutaneous melanoma only), 71% in the brain metastasis subgroup, 36% in the ocular/uveal melanoma subgroup, and 38% in the mucosal melanoma subgroup. CONCLUSION: Nivolumab plus ipilimumab followed by nivolumab monotherapy was tolerable in patients with advanced melanoma and poor prognostic characteristics. Efficacy was similar between the all-treated population and patients with brain metastases. Reduced efficacy was observed in patients with ECOG PS 2, ocular/uveal melanoma, and/or mucosal melanoma, highlighting the continued need for novel treatment options for these difficult-to-treat patients

    Current Welfare Problems Facing Horses in Great Britain as Identified by Equine Stakeholders

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    Despite growing concerns about the welfare of horses in Great Britain (GB) there has been little surveillance of the welfare status of the horse population. Consequently we have limited knowledge of the range of welfare problems experienced by horses in GB and the situations in which poor welfare occurs. Thirty-one in-depth interviews were conducted with a cross -section of equine stakeholders, in order to explore their perceptions of the welfare problems faced by horses in GB. Welfare problems relating to health, management and riding and training were identified, including horses being under or over weight, stabling 24 hours a day and the inappropriate use of training aids. The interviewees also discussed broader contexts in which they perceived that welfare was compromised. The most commonly discussed context was where horses are kept in unsuitable environments, for example environments with poor grazing. The racing industry and travellers horses were identified as areas of the industry where horse welfare was particularly vulnerable to compromise. Lack of knowledge and financial constraints were perceived to be the root cause of poor welfare by many interviewees. The findings give insight into the range of welfare problems that may be faced by horses in GB, the contexts in which these may occur and their possible causes. Many of the problems identified by the interviewees have undergone limited scientific investigation pointing to areas where further research is likely to be necessary for welfare improvement. The large number of issues identified suggests that some form of prioritisation may be necessary to target research and resources effectively

    First-Line, Fixed-Duration Nivolumab Plus Ipilimumab Followed by Nivolumab in Clinically Diverse Patient Populations With Unresectable Stage III or IV Melanoma: CheckMate 401

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    PURPOSE To address the paucity of data in patients with historically poor outcomes, we conducted the single-arm phase IIIb CheckMate 401 study to evaluate the safety and efficacy of nivolumab plus ipilimumab followed by nivolumab monotherapy in clinically diverse patient populations with advanced melanoma. METHODS Treatment-naive patients with unresectable stage III-IV melanoma received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg once every 3 weeks (four doses) followed by nivolumab 3 mg/kg (240 mg following a protocol amendment) once every 2 weeks for ≤24 months. The primary end point was the incidence of grade 3-5 select treatment-related adverse events (TRAEs). Overall survival (OS) was a secondary end point. Outcomes were evaluated in subgroups defined by Eastern Cooperative Oncology Group performance status (ECOG PS), brain metastasis status, and melanoma subtype. RESULTS In total, 533 patients received at least one dose of study drug. Grade 3-5 select TRAEs affecting the GI (16%), hepatic (15%), endocrine (11%), skin (7%), renal (2%), and pulmonary (1%) systems occurred in the all-treated population; similar incidence rates were observed across all subgroups. At 21.6 months' median follow-up, 24-month OS rates were 63% in the all-treated population, 44% in the ECOG PS 2 subgroup (including patients with cutaneous melanoma only), 71% in the brain metastasis subgroup, 36% in the ocular/uveal melanoma subgroup, and 38% in the mucosal melanoma subgroup. CONCLUSION Nivolumab plus ipilimumab followed by nivolumab monotherapy was tolerable in patients with advanced melanoma and poor prognostic characteristics. Efficacy was similar between the all-treated population and patients with brain metastases. Reduced efficacy was observed in patients with ECOG PS 2, ocular/uveal melanoma, and/or mucosal melanoma, highlighting the continued need for novel treatment options for these difficult-to-treat patients
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