Reyerite

Reyerite from the original locality in Greenland has been re-examined using chemical analysis, infra-red absorption, X-ray powder and single-crystal diffraction, and thermal weight-loss curves. The unit cell is trigonal with a 9·74, c 19·04 Å, and the space group is probably P3¯. The unit cell contents are probably best represented as KCa14(Si24O60)(OH)5.5H2O, with some minor replacements. The molecular water is lost reversibly below 400° C. There are indications that the crystal structure is based on Si6O18 rings resembling those in beryl, but linked into sheets by additional tetrahedra.

Reyerite closely resembles truscottite, a mineral found originally in Sumatra, but there are distinct differences, especially in the infra-red pattern. It is not yet certain whether or not the two minerals should be considered as distinct species. Synthetic preparations examined resembled truscottite more closely than reyerite.

What are the mechanisms that enable the reciprocal involvement of seldom heard groups in health and social care research? A rapid realist review protocol

Background: The University College Dublin (UCD) PPI Ignite Connect Network will fundamentally embed public and patient involvement (PPI) in health-related research, education and training, professional practice and administration in UCD’s institutional structures and procedures. A significant focus of the programme of work is on actively engaging and developing long-term reciprocal relationships with seldom heard groups, via our ten inaugural partners. Methods: This rapid realist review will explore what are the mechanisms that are important in actively engaging seldom heard groups in health and social care research.  The review process will follow five iterative steps: (1) clarify scope, (2) search for evidence, (3) appraise primary studies and extract data, (4) synthesise evidence and draw conclusions, and (5) disseminate findings. The reviewers will consult with expert and reference panels to focus the review, provide local contextual insights and develop a programme theory consisting of context–mechanism–outcome configurations. The expert panel will oversee the review process and agree, via consensus, the final programme theory. Review findings will follow the adopted RAMESES guideline and will be disseminated via a report, presentations and peer-reviewed publication. Discussion: The review will update and consolidate evidence on the mechanisms that enable the reciprocal engagement and participation of ‘seldom heard’ groups in health and social care research. Via the expert and reference process, we will draw from a sizeable body of published and unpublished research and grey literature. The local contextual insights provided will aid the development of our programme theories. This new evidence will inform the design and development of the UCD PPI Ignite program focused on ensuring sustained reciprocal partnerships.

Abstract P4-04-06: AZD5363, an AKT inhibitor, significantly inhibits key biomarkers of the AKT pathway and Ki67, in a randomized, placebo, controlled study (STAKT) in human breast cancers

Background: AKT is an important intracellular control point through which Type 1 growth factors and IGFR signal. Mutations in PIK3CA, AKT and PTEN are prevalent in estrogen receptor positive (ER+) breast cancer (BC) and have been implicated in resistance to endocrine therapies. AZD5363 is an inhibitor of AKT 1, 2 and 3 currently in Phase 2 trials for BC and other solid cancers.

Design: The study examined whether AZD5363 impacts on key biomarkers within the AKT pathway and their subsequent effects on Ki67, a marker of tumor proliferation. STAKT is a multi-center, two-stage, double blind, randomized, placebo controlled, biomarker 'window-of-opportunity' trial in women with newly diagnosed, previously untreated ER+ BC who were deemed would require chemotherapy as part of their primary treatment regimen. Stage 1 assessed AZD5363 at a dose of 480mg bd p.o. versus matching placebo. Up to 30 patients per arm were permitted, to allow 12 subjects per arm with evaluable paired biopsies - obtained at baseline, and after 4.5 days of AZD5363 / placebo. Primary endpoint markers were pPRAS40, pGSK3β and Ki67 assessed by immunohistochemistry. pPRAS40 and pGSK3β were assessed by H-scores and measured separately for cytoplasmic (cyto), nuclear (nuc) and total (cyto+nuc) staining. Ki67 was assessed as % positive staining of 500 tumor nuclei. Laboratory staff were blinded to treatment arm and whether the biopsies were taken before or after AZD5363/placebo. Changes in marker expression (both absolute and %) between biopsies were calculated, and compared between the two groups. An ANOVA test was applied for normally distributed data and Wilcoxon Mann-Whitney used if not normally distributed.

Results: 28/36 patients were evaluable with patient & tumor characteristics as follows: 17 received AZD5363 and 11 placebo; the median ages were 48 & 49 years respectively. 27 patients were Caucasian and 1 African-American. Tumors were all ER+. For HER2 status 8 were positive & 9 negative in the AZD5363 treated group compared to 2 & 9 respectively in the placebo group.

For pPRAS40 and pGSK3β cyto was the predominant staining while for Ki67 staining was nuclear. Changes in each marker with associated p-values are shown in the table.

MarkerType of change vs baselineDegree of change in AZD5363 arm (n=17)p-value versus placebo arm (n=11)pPRAS40 (H-score)TotalAbsolute-83.8<0.0001Total%-50.2<0.0001CytoAbsolute-90.0<0.0001Cyto%-55.8<0.0001NucAbsolute+6.90.42Nuc%+8.90.94pGSK3β (H-score)TotalAbsolute-55.30.006Total%-39.00.006CytoAbsolute-53.60.006Cyto%-39.20.006NucAbsolute-2.80.065Nuc%-36.50.058Ki67 (% cells+)Absolute-9.60.031%-29.40.052

Conclusions• AZD5363 for 4.5 days caused highly significant falls in pGSK3β and pPRAS40, key markers of AKT pathway activation

• AZD53643 also caused a significant decline in Ki67 even after only 4.5 days of drug. This is one of the shortest 'window'-studies to report such an early effect on proliferation.

• Placebo controlled 'window' studies of this short duration can provide important evidence of the therapeutic potential early in a drug's development.

Citation Format: Robertson JFR, Coleman RE, Cheung KL, Evans A, Holcombe C, Skene A, Rea D, Ahmed S, Jahan A, Kelly S, Horgan K, Rauchhaus P, Littleford R, Foxley A, Lindemann JPO, Pass M, Rugman P, Deb R, Finlay P, Gee JMW. AZD5363, an AKT inhibitor, significantly inhibits key biomarkers of the AKT pathway and Ki67, in a randomized, placebo, controlled study (STAKT) in human breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-04-06.

Effect of Anticitrullinated Protein Antibody Status on Response to Abatacept or Antitumor Necrosis Factor-α Therapy in Patients with Rheumatoid Arthritis: A US National Observational Study

Objective.

Assess whether baseline anticyclic citrullinated peptide antibodies (anti-CCP) status is associated with treatment response in patients with rheumatoid arthritis (RA) initiating abatacept (ABA) or a tumor necrosis factor-α inhibitor (TNFi).

Methods.

Using the Corrona RA registry, patients were identified who initiated ABA or a TNFi (June 2004–January 2015), had a followup visit 6 months (± 3 mos) after initiation, and anti-CCP measured at or prior to initiation. Primary outcome was mean change in Clinical Disease Activity Index (CDAI) from initiation to 6 months. Treatment response was evaluated based on a typical patient profile (female, aged 57 yrs, body mass index of 30 kg/m2, baseline CDAI of 20, 1 prior biologic, and no comorbidities other than RA). Secondary outcomes included remission and low disease activity.

Results.

There were 566 ABA initiators [anti-CCP+ (≥ 20 units/ml): n = 362; anti-CCP− (< 20 units/ml): n = 204] and 1715 TNFi initiators (anti-CCP+: n = 1113; anti-CCP−: n = 602). Differences between treatment groups included baseline disease duration, CDAI, and prior biologic use. At 6 months, anti-CCP+ ABA initiators were associated with significantly greater CDAI response versus anti-CCP− ABA initiators; no significant difference was observed for TNFi initiators. When considering a typical RA patient profile, CDAI response was greater in anti-CCP+ versus anti-CCP− ABA initiators; anti-CCP+ versus anti-CCP− TNFi initiators were similar. Secondary outcome responses were also greater in anti-CCP+ versus anti-CCP− ABA initiators; TNFi initiators did not differ by anti-CCP status.

Conclusion.

In a US-based clinical practice setting, anti-CCP status was associated with a differential treatment response to ABA, but not TNFi.

Effects of ticagrelor versus clopidogrel on platelet function in fibrinolytic-treated STEMI patients undergoing early PCI

OBJECTIVES

Patients undergoing PCI early after fibrinolytic therapy are at high risk for both thrombotic and bleeding complications. We sought to assess the pharmacodynamic effects of ticagrelor versus clopidogrel in the fibrinolytic-treated STEMI patients undergoing early PCI.

METHODS AND RESULTS

Patients undergoing PCI within 24 hours of tenecteplase (TNK), aspirin, and clopidogrel for STEMI were randomized to receive additional clopidogrel 300 mg followed by 75 mg daily or ticagrelor 180 mg followed by 90 mg twice daily. The platelet reactivity units (PRU) were measured with the VerifyNow Assay before study drug administration (baseline) at 4 and 24 hours post-PCI. The primary end point was PRU ≤208 at 4 hours. A total of 140 patients (74 in ticagrelor and 66 in clopidogrel group) were enrolled. The mean PRU values at baseline were similar for the 2 groups (257.8±52.9 vs 259.5±56.7, P=.85, respectively). Post-PCI, patients on ticagrelor, compared to those on clopidogrel, had significantly lower PRU at 4 hours (78.7±88 vs 193.6±86.5, respectively, P<.001) and at 24 hours (34.5±35.0 and 153.5±75.5, respectively, P<.001). The primary end point was observed in 87.8% (n=65) in the ticagrelor-treated patients compared to 57.6% (n=38) of clopidogrel-treated patients, P<.001.

CONCLUSION

Fibrinolysis-treated STEMI patients who received clopidogrel and aspirin at the time of fibrinolysis and were undergoing early PCI frequently had PRU >208. In this high-risk population, ticagrelor provides more prompt and potent platelet inhibition compared with clopidogrel (Funded by Astra Zeneca; NCT01930591, https://clinicaltrials.gov/ct2/show/NCT01930591).

Identification of biomarkers of response to abatacept in patients with SLE using deconvolution of whole blood transcriptomic data from a phase IIb clinical trial

Objective

To characterise patients with active SLE based on pretreatment gene expression-defined peripheral immune cell patterns and identify clusters enriched for potential responders to abatacept treatment.

Methods

This post hoc analysis used baseline peripheral whole blood transcriptomic data from patients in a phase IIb trial of intravenous abatacept (~10 mg/kg/month). Cell-specific genes were used with a published deconvolution algorithm to identify immune cell proportions in patient samples, and unsupervised consensus clustering was generated. Efficacy data were re-analysed.

Results

Patient data (n=144: abatacept: n=98; placebo: n=46) were grouped into four main clusters (C) by predominant characteristic cells: C1—neutrophils; C2—cytotoxic T cells, B-cell receptor-ligated B cells, monocytes, IgG memory B cells, activated T helper cells; C3—plasma cells, activated dendritic cells, activated natural killer cells, neutrophils; C4—activated dendritic cells, cytotoxic T cells. C3 had the highest baseline total British Isles Lupus Assessment Group (BILAG) scores, highest antidouble-stranded DNA autoantibody levels and shortest time to flare (TTF), plus trends in favour of response to abatacept over placebo: adjusted mean difference in BILAG score over 1 year, −4.78 (95% CI −12.49 to 2.92); median TTF, 56 vs 6 days; greater normalisation of complement component 3 and 4 levels. Differential improvements with abatacept were not seen in other clusters, except for median TTF in C1 (201 vs 109 days).

Conclusions

Immune cell clustering segmented disease severity and responsiveness to abatacept. Definition of immune response cell types may inform design and interpretation of SLE trials and treatment decisions.

Trial registration number

NCT00119678; results.

Simulating topological domains in human chromosomes with a fitting-free model

We discuss a polymer model for the 3D organization of human chromosomes. A chromosome is represented by a string of beads, with each bead being "colored" according to 1D bioinformatic data (e.g., chromatin state, histone modification, GC content). Individual spheres (representing bi- and multi-valent transcription factors) can bind reversibly and selectively to beads with the appropriate color. During molecular dynamics simulations, the factors bind, and the string spontaneously folds into loops, rosettes, and topologically-associating domains (TADs). This organization occurs in the absence of any specified interactions between distant DNA segments, or between transcription factors. A comparison with Hi-C data shows that simulations predict the location of most boundaries between TADs correctly. The model is "fitting-free" in the sense that it does not use Hi-C data as an input; consequently, one of its strengths is that it can - in principle - be used to predict the 3D organization of any region of interest, or whole chromosome, in a given organism, or cell line, in the absence of existing Hi-C data. We discuss how this simple model might be refined to include more transcription factors and binding sites, and to correctly predict contacts between convergent CTCF binding sites.

A window of opportunity for abatacept in RA: is disease duration an independent predictor of low disease activity/remission in clinical practice?

The objective of the study was to examine whether disease duration independently predicts treatment response among biologic-naïve patients with rheumatoid arthritis (RA) initiating abatacept in clinical practice. Using the Corrona RA registry (February 2006–January 2015), biologic-naïve patients with RA initiating abatacept with 12-month (±3 months) follow-up and assessment of disease activity (Clinical Disease Activity Index [CDAI]) at initiation and at 12 months were identified. The primary outcome was mean change in CDAI (ΔCDAI) from baseline to 12 months. Secondary outcomes at 12 months included achievement of low disease activity (LDA; CDAI ≤10 in patients with moderate/high disease activity at initiation) and remission (CDAI ≤2.8 in patients with low, moderate or high disease activity at initiation). Linear and logistic regression analyses were performed to examine the relationship between disease duration and response to abatacept. There were 281 biologic-naïve patients with RA initiating abatacept (disease duration 0–2 years, n = 107; 3–5 years, n = 45; 6–10 years, n = 50; >10 years, n = 79). Increased disease duration was associated with older age (p = 0.047), and the median number of prior conventional disease-modifying antirheumatic drugs used was lowest in the 0- to 2-year duration group (p < 0.001). Mean ΔCDAI (SE) ranged from −10.22 (1.19) for 0–2 years to −4.63 (1.38) for >10 years. In adjusted analyses, shorter disease duration was significantly associated with greater mean ΔCDAI (p = 0.015) and greater likelihood of achieving LDA (p = 0.048). In biologic-naïve patients with RA initiating abatacept, earlier disease (shorter disease duration) was associated with greater ΔCDAI and likelihood of achieving LDA.

Abstract P3-06-03: The short term effects of an AKT inhibitor (AZD5363) on biomarkers of the AKT pathway and anti-tumour activity in a breast cancer paired biopsy study (STAKT trial)

This abstract was withdrawn by the authors.

Liver abscess secondary to an endoscopic tattoo in the colon

Introduction Endoscopic tattooing of colonic lesions has been used safely for their localization. CASE HISTORY We report a 61-year-old female who had left hemicolectomy in 2006 for adenocarcinoma of the left colon (pT3, pN0, M0). Cancer in the transverse colon was discovered during annual colonoscopy surveillance. The lesion was tattooed 5cm proximal to the lesion. Twenty-four days after tattooing, she was admitted to the emergency department with increased levels of inflammatory markers. CT showed an abscess in the left lobe of the liver adjacent to the tattoo site. The abscess was drained under ultrasound guidance. She had antibiotic treatment for 3 weeks and made a full recovery. CONCLUSION Endoscopic tattooing of colonic lesions is safe but this case report highlights the possibility of a rare (but serious) complication that must be taken into consideration.