72 research outputs found
Long-term safety in patients with recurrent ovarian cancer treated with niraparib versus placebo: Results from the phase III ENGOT-OV16/NOVA trial
OBJECTIVE: Niraparib is a poly(ADP-ribose) polymerase (PARP) inhibitor approved for use in heavily pretreated patients and as maintenance treatment in patients with newly-diagnosed or recurrent ovarian cancer following a response to platinum-based chemotherapy. We present long-term safety data for niraparib from the ENGOT-OV16/NOVA trial. METHODS: This multicenter, double-blind, randomized, controlled phase III trial evaluated the efficacy and safety of niraparib for the treatment of recurrent ovarian cancer. Patients were randomly assigned 2:1 to receive either once-daily niraparib 300 mg or placebo. Two independent cohorts were enrolled based on germline BRCA mutation status. The primary endpoint was progression-free survival, reported previously. Long-term safety data were from the most recent data cutoff (September 2017). RESULTS: Overall, 367 patients received niraparib 300 mg once daily. Dose reductions due to TEAEs were highest in month 1 (34%) and declined every month thereafter. Incidence of any-grade and grade ≥ 3 hematologic and symptomatic TEAEs was also highest in month 1 and subsequently declined. Incidence of grade ≥ 3 thrombocytopenia decreased from 28% (month 1) to 9% and 5% (months 2 and 3, respectively), with protocol-directed dose interruptions and/or reductions. Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) were reported in 2 and 6 niraparib-treated patients, respectively, and in 1 placebo patient each. Treatment discontinuations due to TEAEs were <5% in each month and time interval measured. CONCLUSION: These data demonstrate the importance of appropriate dose reduction according to toxicity criteria and support the safe long-term use of niraparib for maintenance treatment in patients with recurrent ovarian cancer. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01847274
Pol II phosphorylation regulates a switch between transcriptional and splicing condensates
The synthesis of pre-mRNA by RNA polymerase II (Pol II) involves the formation of a transcription initiation complex, and a transition to an elongation complex. The large subunit of Pol II contains an intrinsically disordered C-terminal domain that is phosphorylated by cyclin-dependent kinases during the transition from initiation to elongation, thus influencing the interaction of the C-terminal domain with different components of the initiation or the RNA-splicing apparatus. Recent observations suggest that this model provides only a partial picture of the effects of phosphorylation of the C-terminal domain. Both the transcription-initiation machinery and the splicing machinery can form phase-separated condensates that contain large numbers of component molecules: hundreds of molecules of Pol II and mediator are concentrated in condensates at super-enhancers, and large numbers of splicing factors are concentrated in nuclear speckles, some of which occur at highly active transcription sites. Here we investigate whether the phosphorylation of the Pol II C-terminal domain regulates the incorporation of Pol II into phase-separated condensates that are associated with transcription initiation and splicing. We find that the hypophosphorylated C-terminal domain of Pol II is incorporated into mediator condensates and that phosphorylation by regulatory cyclin-dependent kinases reduces this incorporation. We also find that the hyperphosphorylated C-terminal domain is preferentially incorporated into condensates that are formed by splicing factors. These results suggest that phosphorylation of the Pol II C-terminal domain drives an exchange from condensates that are involved in transcription initiation to those that are involved in RNA processing, and implicates phosphorylation as a mechanism that regulates condensate preference
Existence and multiplicity of positive periodic solutions for a class of higher-dimension functional differential equations with impulses
AbstractThis paper deals with the existence of multiple periodic solutions for n-dimensional functional differential equations with impulses. By employing the Krasnoselskii fixed point theorem, we obtain some easily verifiable sufficient criteria which extend previous results
Informing evaluation of a smartphone application for people with acquired brain injury: a stakeholder engagement study
Background
Brain in Hand is a smartphone application (app) that allows users to create structured diaries with problems and solutions, attach reminders, record task completion and has a symptom monitoring system. Brain in Hand was designed to support people with psychological problems, and encourage behaviour monitoring and change. The aim of this paper is to describe the process of exploring the barriers and enablers for the uptake and use of Brain in Hand in clinical practice, identify potential adaptations of the app for use with people with acquired brain injury (ABI), and determine whether the behaviour change wheel can be used as a model for engagement.
Methods
We identified stakeholders: ABI survivors and carers, National Health Service and private healthcare professionals, and engaged with them via focus groups, conference presentations, small group discussions, and through questionnaires. The results were evaluated using the behaviour change wheel and descriptive statistics of questionnaire responses.
Results
We engaged with 20 ABI survivors, 5 carers, 25 professionals, 41 questionnaires were completed by stakeholders. Comments made during group discussions were supported by questionnaire results. Enablers included smartphone competency (capability), personalisation of app (opportunity), and identifying perceived need (motivation). Barriers included a physical and cognitive inability to use smartphone (capability), potential cost and reliability of technology (opportunity), and no desire to use technology or change from existing strategies (motivation). The stakeholders identified potential uses and changes to the app, which were not easily mapped onto the behaviour change wheel, e.g. monitoring fatigue levels, method of logging task completion, and editing the diary on their smartphone.
Conclusions
The study identified that both ABI survivors and therapists could see a use for Brain in Hand, but wanted users to be able to personalise it themselves to address individual user needs, e.g. monitoring activity levels. The behaviour change wheel is a useful tool when designing and evaluating engagement activities as it addresses most aspects of implementation, however additional categories may be needed to explore the specific features of assistive technology interventions, e.g. technical functions
MGMT promoter hypermethylation and K-RAS, PTEN and TP53 mutations in tamoxifen-exposed and non-exposed endometrial cancer cases
background: Tamoxifen has anti-oestrogenic and anti-tumour activity in the breast, but is oestrogenic and carcinogenic in the endometrium. It can induce experimental tumours by both hormonal and DNA-damaging mechanisms, but its carcinogenic mode of action in human endometrium remains unclear. methods: We investigated whether an epigenetic mechanism, involving promoter hypermethylation of the gene for the DNA repair enzyme MGMT (O6-methylguanine DNA methyltransferase), was associated with K-RAS, TP53 and PTEN mutations in endometrial tumours from women treated with tamoxifen (TAM, n=30) or unexposed to the drug (EC, n=38). results: There were significant (PA, occurred in small numbers in both groups. TP53 mutations were of mainly A>G, C>T and indel modifications in both groups, but more frequent in TAM cases. PTEN mutations dominated in EC tumours and were of the type that has large impact on protein function, such as indel or nonsense mutations. These observations alongside the mutational spectrum in PTEN suggest that the malignancies arise from different backgrounds, hence pointing to an effect of tamoxifen. Both groups displayed MGMT promoter hypermethylation. This coincided with mutations more frequently in the TAM (78%) than in the EC (50%) group, even though there were significantly (P<0.05) fewer mutations and methylations in TAM cases. conclusions: Although the difference in coincidence did not reach significance with the current sample size, the findings suggest that epigenetic processes may play a role in the way tamoxifen induces endometrial cancer
Re-examination of the Controversial Coexistence of Traumatic Brain Injury and Posttraumatic Stress Disorder: Misdiagnosis and Self-Report Measures
The coexistence of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) remains a controversial issue in the literature. To address this controversy, we focused primarily on the civilian-related literature of TBI and PTSD. Some investigators have argued that individuals who had been rendered unconscious or suffered amnesia due to a TBI are unable to develop PTSD because they would be unable to consciously experience the symptoms of fear, helplessness, and horror associated with the development of PTSD. Other investigators have reported that individuals who sustain TBI, regardless of its severity, can develop PTSD even in the context of prolonged unconsciousness. A careful review of the methodologies employed in these studies reveals that investigators who relied on clinical interviews of TBI patients to diagnose PTSD found little or no evidence of PTSD. In contrast, investigators who relied on PTSD questionnaires to diagnose PTSD found considerable evidence of PTSD. Further analysis revealed that many of the TBI patients who were initially diagnosed with PTSD according to self-report questionnaires did not meet the diagnostic criteria for PTSD upon completion of a clinical interview. In particular, patients with severe TBI were often misdiagnosed with PTSD. A number of investigators found that many of the severe TBI patients failed to follow the questionnaire instructions and erroneously endorsed PTSD symptoms because of their cognitive difficulties. Because PTSD questionnaires are not designed to discriminate between PTSD and TBI symptoms or determine whether a patient's responses are accurate or exaggerated, studies that rely on self-report questionnaires to evaluate PTSD in TBI patients are at risk of misdiagnosing PTSD. Further research should evaluate the degree to which misdiagnosis of PTSD occurs in individuals who have sustained mild TBI
O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction
Background: The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) confers resistance to alkylating agents. Several methods have been applied to its analysis, with methylation-specific polymerase chain reaction (MSP) the most commonly used for promoter methylation study, while immunohistochemistry (IHC) has become the most frequently used for the detection of MGMT protein expression. Agreement on the best and most reliable technique for evaluating MGMT status remains unsettled. The aim of this study was to perform a systematic review and meta-analysis of the correlation between IHC and MSP. Methods A computer-aided search of MEDLINE (1950-October 2009), EBSCO (1966-October 2009) and EMBASE (1974-October 2009) was performed for relevant publications. Studies meeting inclusion criteria were those comparing MGMT protein expression by IHC with MGMT promoter methylation by MSP in the same cohort of patients. Methodological quality was assessed by using the QUADAS and STARD instruments. Previously published guidelines were followed for meta-analysis performance. Results Of 254 studies identified as eligible for full-text review, 52 (20.5%) met the inclusion criteria. The review showed that results of MGMT protein expression by IHC are not in close agreement with those obtained with MSP. Moreover, type of tumour (primary brain tumour vs others) was an independent covariate of accuracy estimates in the meta-regression analysis beyond the cut-off value. Conclusions Protein expression assessed by IHC alone fails to reflect the promoter methylation status of MGMT. Thus, in attempts at clinical diagnosis the two methods seem to select different groups of patients and should not be used interchangeably
A novel clinical trial recruitment strategy for women's cancer
Objective To address a deficiency in clinical trial and research enrollment in gynecologic cancer studies, we launched a paper based patient research registry. To improve registry enrollment, we transitioned to an online registry and trial matching mechanism to aid women in accessing open studies. Methods Utilizing a validated verification platform, we designed a web-based registry and trial matching mechanism for women over age 18. Participants completed a questionnaire to provide information for trial matching. A focus group of registry participants was held 9 months after the start of the study to evaluate barriers to participation. Results A total of 322 women were enrolled in the online registry over a 14 month period which was a 4.3 fold increase over the paper-based registry (p < 0.0001). Two hundred and sixty three (82%) women were matched to at least one study. Fifteen percent (39/263) of those eligible for studies went on to enroll. The online enrollment rate to studies was not different from that observed in the paper-based registry (26/172, p = 0.934), however, the web-based registry linked participants to subsequent studies 27% more rapidly (68 (+/- 98) days vs. 93 (+/- 81) days for the paper-based registry, p = 0.017). Focus group participants identified areas for improvement. Conclusion Web-based patient driven registry provides dramatic improvement in the number of participants enrolled and the time to trial linkage compared to a paper based registry at a single institution. Further studies of barriers to research participation are necessary to improve on this model
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Erratum: "a novel clinical trial recruitment strategy for women's cancer" (Gynecologic Oncology (2015) 138 (445-448))
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