Warfarin therapy in atrial fibrillation: assessment of patient knowledge of risks and benefits

Patients with atrial fibrillation are at an increased risk for stroke, and many benefits from anticoagulation. Despite the emergence of direct oral anticoagulants, many patients continue to rely on warfarin for their anticoagulation due to logistical, pharmacokinetic, clinical, or patient preference issues. Previous work has suggested that outcomes of warfarin therapy are related to patient education/knowledge. We assessed knowledge of indications, benefits, and complications of warfarin therapy in 99 randomly selected patients enrolled in the Warfarin Anticoagulation Clinic at the Mayo Clinic in Florida who were taking warfarin for non-valvular atrial fibrillation. Patients were labeled as 'knowledgeable' or 'not knowledgeable' regarding warfarin therapy according to the results of a cross-sectional questionnaire. The majority of patients in both the knowledgeable and not knowledgeable groups displayed understanding that they were taking warfarin for atrial fibrillation (valvular vs non-valvular atrial fibrillation was not an included answer choice). However, there was a clear lack of knowledge amongst patients with atrial fibrillation in both groups about their stroke risk while on and off warfarin, and their risk of major bleeding or adverse events related to their warfarin therapy. There was only a significant difference between the two groups regarding their knowledge of what increases or decreases the risk of bleeding while on warfarin. There was no major difference between the groups with regards to demographic and medical characteristics, except that 'not knowledgeable' patients tended to have more peripheral vascular disease, ulcer disease, and moderate-severe renal disease compared to 'knowledgeable' patients.

Hepatic iron overload identified by magnetic resonance imaging-based T2* is a predictor of non-diagnostic elastography

Background

Magnetic resonance elastography (MRE) is a non-invasive test used to assess liver stiffness and fibrosis in chronic liver disease, which includes systemic iron overload. However, iron deposition by itself is associated with technical failure of MRE of the liver which necessitates the use of invasive liver biopsy as an alternative monitoring method for these patients. T2*-weighted magnetic resonance imaging (T2*) is a reliable modality to asses for hepatic as well as total body iron overload. Therefore, we aimed to determine a cutoff value on the T2* reading at which MRE would no longer provide accurate stiffness measurements in patients with iron overload.

Methods

Ninety-five patients with iron overload who underwent MRE at our institution, between 2010 and 2017 were reviewed retrospectively. We compared T2* values between patients with adequate elastography (N=63) versus those with non-diagnostic elastography (N=32). We additionally examined the ability of T2* to predict the likelihood of non-diagnostic elastography by estimating area under the ROC curve (AUC).

Results

T2* was significantly different between patients with and without an adequate elastography (P<0.0001) and predicted occurrence of non-diagnostic elastography with an AUC of 0.95. All patients with a non-diagnostic elastography had a T2* value below 20 milliseconds (ms), and correspondingly 55% of the patients with a T2* value below 20 ms had a non-diagnostic elastography. The subgroups of patients with a T2* value ≤10, ≤8, and ≤6 ms, had a higher likelihood of non-diagnostic elastography (87%, 92%, and 95%, respectively).

Conclusions

T2* can be used to accurately predict which patients are most likely to have a non-diagnostic elastography reading. T2* of 20 ms or lower reflects a higher likelihood of non-diagnostic elastography.

NOTCH signaling specifies arterial-type definitive hemogenic endothelium from human pluripotent stem cells

NOTCH signaling is required for the arterial specification and formation of hematopoietic stem cells (HSCs) and lympho-myeloid progenitors in the embryonic aorta-gonad-mesonephros region and extraembryonic vasculature from a distinct lineage of vascular endothelial cells with hemogenic potential. However, the role of NOTCH signaling in hemogenic endothelium (HE) specification from human pluripotent stem cell (hPSC) has not been studied. Here, using a chemically defined hPSC differentiation system combined with the use of DLL1-Fc and DAPT to manipulate NOTCH, we discover that NOTCH activation in hPSC-derived immature HE progenitors leads to formation of CD144⁺CD43⁻CD73⁻DLL4⁺Runx1 + 23-GFP⁺ arterial-type HE, which requires NOTCH signaling to undergo endothelial-to-hematopoietic transition and produce definitive lympho-myeloid and erythroid cells. These findings demonstrate that NOTCH-mediated arterialization of HE is an essential prerequisite for establishing definitive lympho-myeloid program and suggest that exploring molecular pathways that lead to arterial specification may aid in vitro approaches to enhance definitive hematopoiesis from hPSCs.

It is unclear whether arterial specification is required for hematopoietic stem cell formation. Here, the authors use a chemically defined human pluripotent stem cell (hPSC) differentiation system to show the role of NOTCH signaling in forming arterial-type hemogenic endothelial cells.

A human VE-cadherin-tdTomato and CD43-green fluorescent protein dual reporter cell line for study endothelial to hematopoietic transition

Human embryonic stem cell line WA01 was genetically modified using zinc-finger nucleases and the PiggyBac/transponson system to introduce a fluorescence reporter for VE-cadherin (VEC; tdTomato) and CD43 (eGFP). Phenotypic and functional assays for pluripotency revealed the modified hES cell reporter lines remained normal. When the cells were differentiated into hematoendothelial lineages, either by directed differentiation or direct reprogramming, flow cytometric and fluorescence microscopy showed that VEC+ endothelial cells express tdTomato and CD43+ hematopoietic progenitors express eGFP.

Ecosystem-based adaptation in marine ecosystems of tropical Oceania in response to climate change

Tropical Oceania, including Melanesia, Polynesia, Micronesia and northern Australia, is one of the most biodiverse regions of the world. Climate change impacts have already occurred in the region and will become one of the greatest threats to biodiversity and people. Climate projections indicate that sea levels will rise in many places but not uniformly. Islands will warm and annual rainfall will increase and exhibit strong decadal variations. Increases in global atmospheric CO2 concentration are causing ocean acidification, compromising the ability of organisms such as corals to maintain their calcium carbonate skeletons. We discuss these climate threats and their implications for the biodiversity of several ecosystems (coral reefs, seagrass and mangroves) in the region. We highlight current adaptation approaches designed to address these threats, including efforts to integrate ecosystem and community-based approaches. Finally, we identify guiding principles for developing effective ecosystem-based adaptation strategies. Despite broad differences in governance and social systems within the region, particularly between Australia and the rest of the Pacific, threats and planning objectives are similar. Ensuring community awareness and participation are essential everywhere. The science underpinning ecosystem-based adaptation strategies is in its infancy but there is great opportunity for communicating approaches and lessons learnt between developing and developed nations in tropical Oceania.

Impact of brain metastases on health care costs in metastatic breast cancer: A multinational study

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Background: Incidence of brain metastases (BM) are thought to be particularly high among patients with ErbB2+ (HER2+) breast cancer and have been associated with a poor survival prognosis. A previous study identified such patients as a considerable financial burden for health systems in Germany and France when compared to metastatic breast cancer (MBC) without BM. The objective of this study was to extend that analysis to estimate health care costs in Italy, Spain and the UK. Methods: Patient treatment histories, including drugs, specialist visits, procedures, inpatient stays etc, were collected retrospectively from a panel of oncologists for women with MBC across Italy, Spain and the UK, last seen by the responding oncologist during Q3-Q4 2006 or Q3-Q4 2007. To identify ErbB2+ patients they all had to have received/were receiving trastuzumab (TZ) for MBC. Patients were sampled so as to ensure the collection contained a minimum of 50 cases with BM and 200 histories overall (remainder controls). All costs within the observation period (initiation of TZ to date last seen) were calculated from a payer's perspective for patients who had developed BM and those who had not. Linear stepwise regression took into account potential confounding of time related covariates. Results: The study included 268 Italian (146 cases), 215 Spanish (126 cases) and 243 UK patients (103 cases). BM diagnosis was associated with significantly more expensive treatment histories than those patients without. Service costs such as radiotherapy and hospital visits were found to be key drivers for these differences (p<.001). Conclusions: The significantly greater cost associated with treatment of BMs in ErbB2+ MBC patients from Italy, Spain and the UK is consistent with results from identical French and German analyses. Therapies that reduce the incidence of BMs may therefore decrease the overall financial burden of ErbB2+ MBC.

[Table: see text]

[Table: see text]

Gastroesophageal reflux

Gastroesophageal reflux is common in infants and generally resolves spontaneously within the first year of life as the lower esophageal sphincter mechanism matures. The reflux is only considered a "disease" (GERD) when it becomes symptomatic or causes pathological consequences. GERD is commonly associated with esophageal atresia and there is a high incidence in neurologically impaired children; in both groups conservative treatment is notoriously ineffective. The diagnosis of GER is made on upper gastrointestinal contrast studies, endoscopy and pH monitoring. Medical management comprises antacids, reduction of gastric acid production and prokinetic agents. The indications for antireflux surgery include an established esophageal stricture, associated anatomical defect and failure of medical therapy. Apnoeic episodes secondary to documented GER in the infant, constitute an absolute indication for early surgery.

Social care's impact on emergency medicine: a model to test

Mainly in response to the policy drive to avoid unnecessary acute hospital admissions and delayed discharge on social grounds, there has been a gradual development of social work services attached to emergency departments (EDs) in the UK. In the absence of a clearly articulated evidence base or debate about the roles of ED attached social workers, a model of ED based social work practice and indicative supporting evidence is presented. It is argued that social workers may be able to contribute to the efficiency and effectiveness of hospital services while providing a key point of access to social care services. A number of obstacles remain to the implementation of this model of service, including the narrow focus of current social care practice, the hours that a social work service is normally provided, chronic under-funding, and continuing perverse incentives in the health and social care system. More systematic evidence in the UK context is needed to support the case for change.

Assessment of mechanism of acquired skewed X inactivation by analysis of twins

Skewed X-chromosome inactivation in peripheral blood granulocytes becomes more frequent with increasing age, affecting up to half of those over 75 years old. To investigate the mechanisms underlying this phenomenon, X-inactivation profiles in 33 monozygotic and 22 dizygotic elderly twin pairs were studied. Differential methylation-sensitive restriction enzyme cutting at a hypervariable locus in the human androgen receptor gene (HUMARA) was studied on purified granulocytes using T cells as controls. A large genetic effect on skewed granulocytic X inactivation was shown (P <.05); heritability was estimated to be 0.68. A minor part (SD.0151 relative allele frequency [ie, larger/smaller] units) of the observed variance is due to experimental error. A further contributor to acquired skewing is stochastic asymmetric stem cell division, which was modeled and shown as unlikely to account for a substantial part of variance. Two monozygotic twin pairs had X-inactivation ratios skewed markedly in opposite directions, evidence for a further stochastic mechanism, suggestive of a single overrepresented clone. In conclusion, all 3 suggested mechanisms contribute to acquired X inactivation but the dominant mechanism is genetic selection. The observed proportion of putatively clonal hematopoiesis is similar to the lifetime incidence of hematopoietic stem cell malignancy consistent with the concept that clonal hematopoiesis precedes stem cell malignancy.

The public awareness of aphasia: an international survey

We surveyed 929 shoppers in Exeter (England), Louisiana (USA) and Sydney (Australia) to determine what they knew of aphasia. Between 10% and 18% said they had heard of aphasia but only between 1.5% and 7.6% had even some basic knowledge of aphasia. We found that more females knew something about aphasia than males and that older people were more likely to have heard of it, although those with some knowledge were significantly younger. Informants had heard of aphasia mainly through their work or the media and were mainly professionals like teachers, nurses, therapists, managers and administrators, followed by a retired/student group. We found some differences in awareness levels in the different locations we sampled. Results have implications for targeting awareness raising and campaigning.

Complement activation in platelet concentrates is surface-dependent and modulated by the platelets

Activation of platelets during storage may contribute to the loss of function and viability known as the platelet storage lesion. We investigated the role of complement activation as a possible mediator of the platelet storage lesion. We studied platelet bags stored up to 5 days under standard blood bank conditions and monitored the generation of several complement activation fragments from both the classical and alternative pathways. To assess the role of noncellular artificial surfaces in the activation of complement, parallel bags were prepared containing platelet-poor plasma. The levels of C4d and C3a increased steadily over time in storage, as did the level of the inactivated membrane attack complex SC5b-9. Generation of C4d, C5a, and SC5b-9 was greater in the absence of platelets than when platelets were present in the container. C5a levels in both groups were low and remained so during storage, suggesting that the C5a generated became surface associated. Using flow cytometry we detected C3 and C3a, but not C9, on the platelet surface. The percentage of C3-positive platelets peaked at the third day of storage; by day five platelet-associated C3 had declined. Decay accelerating factor expression on the platelet surface increased with time in storage and in parallel with CD63 expression. Based on the C4d levels, complement activation proceeded via the classical pathway; minimal generation of the alternative pathway activation fragment. Bb was seen in either the presence or absence of platelets. As an indirect measure of the activation of C1, the functional level of C1 esterase inhibitor (C1INH) was determined. C1INH levels declined over time in storage in bags containing only plasma; however, in the presence of platelets, the levels remained constant presumably because of release of C1INH from the alpha-granules of activated platelets.

Four distinct regulatory regions of the cut locus and their effect on cell type specification in Drosophila

The cut gene in Drosophila is necessary in at least one cell type, the external sensory organs, for proper cell type specification and morphogenesis. It is also expressed in a variety of other tissues, where its function is less well characterized. Previous work has demonstrated that mutations affecting all the tissues map in the transcribed and translated portion of the gene, while mutations that are tissue specific in their effects map in the 140 kb upstream of the most 5' exon known. Within that 140 kb, the mutations fall into four subregions, two of which contain mutations affecting unique sets of tissues and the other two of which contain mutations that affect a third set. Our examination of the defects of mutants, their complementation behavior, and their effect on the distribution of the cut protein in embryos, alters the picture in three important ways. First, some mutations convert the cells of the Malpighian tubules into what appear to be gut cells, suggesting that cut is necessary for cell type specification and morphogenesis in a variety of tissues. Second, mutations in each of the four subregions in the 140 kb of upstream DNA cause a different set of phenotypes, suggesting that the regulatory region contains at least four separate units with different tissue specific functions. And third, mutations have now been identified that map in the transcribed and translated portion of the gene but that have tissue specific effects.