523 research outputs found

    Generation of a poor prognostic chronic lymphocytic leukemia-like disease model: PKC subversion induces up-regulation of PKC II expression in B lymphocytes

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    Overwhelming evidence identifies the microenvironment as a critical factor in the development and progression of chronic lymphocytic leukemia, underlining the importance of developing suitable translational models to study the pathogenesis of the disease. We previously established that stable expression of kinase dead protein kinase C alpha in hematopoietic progenitor cells resulted in the development of a chronic lymphocytic leukemia-like disease in mice. Here we demonstrate that this chronic lymphocytic leukemia model resembles the more aggressive subset of chronic lymphocytic leukemia, expressing predominantly unmutated immunoglobulin heavy chain genes, with upregulated tyrosine kinase ZAP-70 expression and elevated ERK-MAPK-mTor signaling, resulting in enhanced proliferation and increased tumor load in lymphoid organs. Reduced function of PKCα leads to an up-regulation of PKCβII expression, which is also associated with a poor prognostic subset of human chronic lymphocytic leukemia samples. Treatment of chronic lymphocytic leukemia-like cells with the selective PKCβ inhibitor enzastaurin caused cell cycle arrest and apoptosis both in vitro and in vivo, and a reduction in the leukemic burden in vivo. These results demonstrate the importance of PKCβII in chronic lymphocytic leukemia-like disease progression and suggest a role for PKCα subversion in creating permissive conditions for leukemogenesis

    The COMMAND trial of cognitive therapy for harmful compliance with command hallucinations (CTCH) : a qualitative study of acceptability and tolerability in the UK

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    Objectives To explore service user experiences of a 9-month cognitive behavioural therapy for command hallucinations in the context of a randomised controlled trial including their views on acceptability and tolerability of the intervention. Design Qualitative study using semistructured interviews. Setting The study took place across three sites: Birmingham, Manchester and London. Interviews were carried out at the sites where therapy took place which included service bases and participants’ homes. Participants Of 197 patients who consented to the trial, 98 received the Cognitive Behavior Therapy for Command Hallucinations (CTCH) intervention; 25 (15 males) of whom were randomly selected and consented to the qualitative study. The mean age of the sample was 42 years, and 68% were white British. Results Two superordinate themes were identified: participants’ views about the aspects of CTCH they found most helpful; and participants’ concerns with therapy. Helpful aspects of the therapy included gaining control over the voices, challenging the power and omniscience of the voices, following a structured approach, normalisation and mainstreaming of the experience of voices, and having peer support alongside the therapy. Concerns with the therapy included anxiety about completing CTCH tasks, fear of talking back to voices, the need for follow-up and ongoing support and concerns with adaptability of the therapy. Conclusions Interpretation: CTCH was generally well received and the narratives validated the overall approach. Participants did not find it an easy therapy to undertake as they were challenging a persecutor they believed had great power to harm; many were concerned, anxious and occasionally disappointed that the voices did not disappear altogether. The trusting relationship with the therapist was crucial. The need for continued support was expressed

    Anon-Pass: Practical Anonymous Subscriptions

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    We present the design, security proof, and implementation of an anonymous subscription service. Users register for the service by providing some form of identity, which might or might not be linked to a real-world identity such as a credit card, a web login, or a public key. A user logs on to the system by presenting a credential derived from information received at registration. Each credential allows only a single login in any authentication window, or epoch. Logins are anonymous in the sense that the service cannot distinguish which user is logging in any better than random guessing. This implies unlinkability of a user across different logins. We find that a central tension in an anonymous subscription service is the service provider’s desire for a long epoch (to reduce server-side computation) versus users’ desire for a short epoch (so they can repeatedly “re-anonymize” their sessions). We balance this tension by having short epochs, but adding an efficient operation for clients who do not need unlinkability to cheaply re-authenticate themselves for the next time period. We measure performance of a research prototype of our pro- tocol that allows an independent service to offer anonymous access to existing services. We implement a music service, an Android-based subway-pass application, and a web proxy, and show that adding anonymity adds minimal client latency and only requires 33 KB of server memory per active user

    Admission to hospital following head injury in England: Incidence and socio-economic associations

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    BACKGROUND: Head injury in England is common. Evidence suggests that socio-economic factors may cause variation in incidence, and this variation may affect planning for services to meet the needs of those who have sustained a head injury. METHODS: Socio-economic data were obtained from the UK Office for National Statistics and merged with Hospital Episodes Statistics obtained from the Department of Health. All patients admitted for head injury with ICD-10 codes S00.0–S09.9 during 2001–2 and 2002–3 were included and collated at the level of the extant Health Authorities (HA) for 2002, and Primary Care Trust (PCT) for 2003. Incidence was determined, and cluster analysis and multiple regression analysis were used to look at patterns and associations. Results: 112,718 patients were admitted during 2001–2 giving a hospitalised incidence rate for England of 229 per 100,000. This rate varied across the English HA's ranging from 91–419 per 100,000. The rate remained unchanged for 2002–3 with a similar magnitude of variation across PCT's. Three clusters of HA's were identified from the 2001–2 data; those typical of London, those of the Shire counties, and those of Other Urban authorities. Socio-economic factors were found to account for a high proportion of the variance in incidence for 2001–2. The same pattern emerged for 2002–3 at the PCT level. The use of public transport for travel to work is associated with a decreased incidence and lifestyle indicators, such as the numbers of young unemployed, increase the incidence. CONCLUSION: Head injury incidence in England varies by a factor of 4.6 across HA's and PCT's. Planning head injury related services at the local level thus needs to be based on local incidence figures rather than regional or national estimates. Socio-economic factors are shown to be associated with admission, including travel to work patterns and lifestyle indicators, which suggests that incidence is amenable to policy initiatives at the macro level as well as preventive programmes targeted at key groups

    AKT/mTORC2 inhibition activates FOXO1 function in CLL cells reducing B cell receptor-mediated survival

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    Purpose: To determine whether inhibition of mechanistic target of rapamycin (mTOR) kinase-mediated signaling represents a valid therapeutic approach for chronic lymphocytic leukemia (CLL). Experimental Design: Stratification of mTOR activity was carried out in primary CLL patient samples and an aggressive CLL-like mouse model. The potency of dual mTOR inhibitor AZD8055 to induce apoptosis in primary CLL cells was assessed in the presence/absence of B cell receptor (BCR) ligation. Furthermore, we addressed the molecular and functional impact of dual mTOR inhibition in combination with BTK inhibitor ibrutinib. Results: Differential regulation of basal mTORC1 activity was observed in poor prognostic CLL samples, with elevated p4EBP1T37/46 and decreased p70S6 kinase activity, suggesting that dual mTORC1/2 inhibitors may exhibit improved response in poor prognostic CLL compared with rapalogs. AZD8055 treatment of primary CLL cells significantly reduced CLL survival in vitro compared with rapamycin, preferentially targeting poor prognostic subsets and overcoming BCR-mediated survival advantages. Furthermore, AZD8055, and clinical analog AZD2014, significantly reduced CLL tumor load in mice. AKT substrate FOXO1, while overexpressed in CLL cells of poor prognostic patients in LN biopsies, peripheral CLL cells, and mouse-derived CLL-like cells, appeared to be inactive. AZD8055 treatment partially reversed FOXO1 inactivation downstream of BCR crosslinking, significantly inhibiting FOXO1T24 phosphorylation in an mTORC2-AKT-dependent manner, to promote FOXO1 nuclear localization, activity and FOXO1-mediated gene regulation. FOXO1 activity was further significantly enhanced on combining AZD8055 with ibrutinib. Conclusions: Our studies demonstrate that dual mTOR inhibitors show promise as future CLL therapies, particularly in combination with ibrutinib

    Submacular Choroid Thickness Increases During Long-Duration Spaceflight

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    The Spaceflight Associated Neuro-ocular Syndrome (SANS) is characterized by the development of optic disc edema, choroidal folds, cotton-wool spots, globe flattening, and/or refractive error changes greater than or equal to 0.75D during long-duration spaceflight to the International Space Station (ISS). It is hypothesized that these findings result from the headward fluid shift that occurs due to weightlessness. We can induce a headward fluid shift on Earth using positional changes and on ISS due to weightlessness. Lower-body negative pressure (LBNP) is used to reverse the headward fluid shift by drawing fluid into the lower body and can be used on Earth and on ISS

    Neurocognitive function in HIV infected patients on antiretroviral therapy

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    OBJECTIVE To describe factors associated with neurocognitive (NC) function in HIV-positive patients on stable combination antiretroviral therapy. DESIGN We undertook a cross-sectional analysis assessing NC data obtained at baseline in patients entering the Protease-Inhibitor-Monotherapy-Versus-Ongoing-Triple therapy (PIVOT) trial. MAIN OUTCOME MEASURE NC testing comprised of 5 domains. Raw results were z-transformed using standard and demographically adjusted normative datasets (ND). Global z-scores (NPZ-5) were derived from averaging the 5 domains and percentage of subjects with test scores >1 standard deviation (SD) below population means in at least two domains (abnormal Frascati score) calculated. Patient characteristics associated with NC results were assessed using multivariable linear regression. RESULTS Of the 587 patients in PIVOT, 557 had full NC results and were included. 77% were male, 68% Caucasian and 28% of Black ethnicity. Mean (SD) baseline and nadir CD4+ lymphocyte counts were 553(217) and 177(117) cells/µL, respectively, and HIV RNA was <50 copies/mL in all. Median (IQR) NPZ-5 score was -0.5 (-1.2/-0) overall, and -0.3 (-0.7/0.1) and -1.4 (-2/-0.8) in subjects of Caucasian and Black ethnicity, respectively. Abnormal Frascati scores using the standard-ND were observed in 51%, 38%, and 81%, respectively, of subjects overall, Caucasian and Black ethnicity (p<0.001), but in 62% and 69% of Caucasian and Black subjects using demographically adjusted-ND (p = 0.20). In the multivariate analysis, only Black ethnicity was associated with poorer NPZ-5 scores (P<0.001). CONCLUSIONS In this large group of HIV-infected subjects with viral load suppression, ethnicity but not HIV-disease factors is closely associated with NC results. The prevalence of abnormal results is highly dependent on control datasets utilised. TRIAL REGISTRY ClinicalTrials.gov, NCT01230580

    Pharmacokinetics, safety and tolerability of olaparib and temozolomide for recurrent glioblastoma: results of the phase I OPARATIC trial

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    Background: The poly(ADP-ribose) polymerase (PARP) inhibitor olaparib potentiated radiation and temozolomide chemotherapy in pre-clinical glioblastoma models but brain penetration was poor. Clinically, PARP inhibitors exacerbate the hematological side-effects of temozolomide. The OPARATIC trial was conducted to measure penetration of recurrent glioblastoma by olaparib, and assess the safety and tolerability of its combination with temozolomide. Methods: Pre-clinical pharmacokinetic studies evaluated olaparib tissue distribution in rats and tumor-bearing mice. Adult patients with recurrent glioblastoma received various doses and schedules of olaparib and low-dose temozolomide in a 3+3 design. Suitable patients received olaparib prior to neurosurgical resection; olaparib concentrations in plasma, tumour core and tumour margin specimens were measured by mass spectrometry. A dose expansion cohort tested tolerability and efficacy of the recommended phase II dose (RP2D). Radiosensitizing effects of olaparib were measured by clonogenic survival in glioblastoma cell lines. Results: Olaparib was a substrate for multi-drug resistance protein-1 and showed no brain penetration in rats but was detected in orthotopic glioblastoma xenografts. Clinically, olaparib was detected in 71/71 tumor core specimens (27 patients, median 496nM) and 21/21 tumor margin specimens (9 patients, median 512.3nM). Olaparib exacerbated TMZ-related hematological toxicity, necessitating intermittent dosing. RP2D was olaparib 150mg (3 days/week) with TMZ 75mg/m2 daily for 42 days. Fourteen (36%) of 39 evaluable patients were progression-free at 6 months. Olaparib radiosensitized six glioblastoma cell lines at clinically relevant concentrations of 100 and 500 nM. Conclusions: Olaparib reliably penetrates recurrent glioblastoma at radiosensitizing concentrations, supporting further clinical development and highlighting the need for better pre-clinical models
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