Heparin Mimic Material Derived from Cellulose Nanocrystals.

This study analyzes and evaluates the use of cellulose nanocrystals (CNCs), stiff nanosized natural materials that have been modified to mimic heparin. These CNCs are simple polysaccharides with a similar backbone structure to heparin, which when modified reduces coagulation and potentially the long-term effects of solution-based anticoagulants. Thus, CNCs represent an ideal foundation for generating materials biocompatible with blood. In this study, we developed a biocompatible material that inhibits blood clotting through surface functionalization to mimic heparin. Surface chemistry of CNCs was modified from "plain" CNCs (70 mmol SO3-/kg) to 500 mmol COO-/kg (TEMPO-oxidized CNCs) and 330 mmol SO3-/kg CNCs (sulfonated CNCs). Platelet adherence and blood assays show that changes in functionalization reduce coagulation. By utilizing and modifying CNCs reactive functional groups, we create a material with unique and favorable mechanical properties while also reducing clotting.

Elimination of the fibrinogen integrin αMß2-binding motif improves renal pathology in mice with sickle cell anemia.

Sickle cell anemia (SCA) is caused by a point mutation in the ß-globin gene that leads to devastating downstream consequences including chronic hemolytic anemia, episodic vascular occlusion, and cumulative organ damage resulting in death. SCA patients show coagulation activation and inflammation even in the absence of vascular occlusion. The coagulation factor fibrinogen is not only central to hemostasis but also plays important roles in pathologic inflammatory processes, in part by engaging neutrophils/macrophages through the αMß2 integrin receptor. To determine whether fibrin(ogen)-mediated inflammation is a driver of SCA-associated pathologies, hematopoietic stem cells from Berkeley sickle mice were transplanted into homozygous Fibγ390-396A mice that express normal levels of a mutant form of fibrin(ogen) that does not engage αMß2 Fibγ390-396A mice with SCA displayed an impressive reduction of reactive oxygen species (ROS) in white blood cells (WBCs), decreased circulating inflammatory cytokines/chemokines, and significantly improved SCA-associated glomerular pathology highlighted by reduced glomerulosclerosis, inflammatory cell infiltration, ischemic lesions, mesangial thickening, mesangial hypercellularity, and glomerular enlargement. In addition, Fibγ390-396A mice with SCA had improved glomerular protective responses and podocyte/mesangial transcriptional signatures that resulted in reduced albuminuria. Interestingly, the fibrinogen γ390-396A mutation had a negligible effect on cardiac, lung, and liver functions and pathologies in the context of SCA over a year-long observation period. Taken together, our data support that fibrinogen significantly contributes to WBC-driven inflammation and ROS production, which is a key driver of SCA-associated glomerulopathy, and may represent a novel therapeutic target against irreversible kidney damage in SCA.

Workplace continuing education for nurses caring for hospitalised older people.

AIMS AND OBJECTIVES: To develop, implement and evaluate a workplace continuing education programme about nursing care of hospitalised older people. BACKGROUND: The healthcare system cannot rely solely upon nurses' prelicensure education to prepare them to meet the evolving needs of hospitalised older patients. Over the past decade, there has been a dramatic rise in the proportion of older people in hospitals, yet many nurses do not have specialised knowledge about the unique care needs of this population. DESIGN: A multimethod pre-to post-design was employed. METHODS: Between September 2013 and April 2014, data were collected via surveys, focus groups and interviews. Thirty-two Registered Nurses initially enrolled in the programme of which 22 completed all data points. Three managers also participated in interviews. One-way repeated-measures ANOVAs were conducted to evaluate the effect of the programme and change over time. Qualitative data were analysed using thematic analysis. RESULTS: Survey results indicated improvements in perceptions about nursing care of older people but no changes in knowledge. Themes generated from the qualitative data focused on participants' experiences of taking part in the programme and included: (i) relevance of content and delivery mode, (ii) value of participating in the programme and (iii) continuing education in the context of acute care. CONCLUSIONS: This study illustrated the potential role of workplace continuing education in improving care for hospitalised older people, particularly the potential to change nurses' perceptions about this population. Nurses prefer learning opportunities that are varied in delivery of educational elder-focused content and accessible at work. Organisational leaders need to consider strategies that minimise potential barriers to workplace continuing education. IMPLICATIONS FOR PRACTICE: Workplace continuing education can play a key role in improving quality of care for hospitalized older adults and ought to be a priority for employers planning education for nurses.

Plasminogen Deficiency Delays the Onset and Protects from Demyelination and Paralysis in Autoimmune Neuroinflammatory Disease.

Multiple sclerosis (MS) is a neuroinflammatory, demyelinating disease of the CNS. Fibrinogen deposition at sites of blood-brain barrier breakdown is a prominent feature of neuroinflammatory disease and contributes to disease severity. Plasminogen, the primary fibrinolytic enzyme, also modifies inflammatory processes. We used a murine model of MS, experimental autoimmune encephalomyelitis (EAE), to evaluate the hypothesis that the loss of plasminogen would exacerbate neuroinflammatory disease. However, contrary to initial expectations, EAE-challenged plasminogen-deficient (Plg-) mice developed significantly delayed disease onset and reduced disease severity compared with wild-type (Plg+) mice. Similarly, pharmacologic inhibition of plasmin activation with tranexamic acid also delayed disease onset. The T-cell response to immunization was similar between genotypes, suggesting that the contribution of plasminogen was downstream of the T-cell response. Spinal cords from EAE-challenged Plg- mice demonstrated significantly decreased demyelination and microglial/macrophage accumulation compared with Plg+ mice. Although fibrinogen-deficient mice or mice with combined deficiencies of plasminogen and fibrinogen had decreased EAE severity, they did not exhibit the delay in EAE disease onset, as seen in mice with plasminogen deficiency alone. Together, these data suggest that plasminogen and plasmin-mediated fibrinolysis is a key modifier of the onset of neuroinflammatory demyelination.SIGNIFICANCE STATEMENT Multiple sclerosis is a severe, chronic, demyelinating disease. Understanding the pathobiology related to the autoreactive T-cell and microglial/macrophage demyelinating response is critical to effectively target therapeutics. We describe for the first time that deficiency of plasminogen, the key fibrinolytic enzyme, delays disease onset and protects from the development of the paralysis associated with a murine model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Administration of a widely used, pharmacologic inhibitor of plasminogen activation, tranexamic acid, also delays the onset of neuroinflammation associated with EAE.

Limiting prothrombin activation to meizothrombin is compatible with survival but significantly alters hemostasis in mice.

Thrombin-mediated proteolysis is central to hemostatic function but also plays a prominent role in multiple disease processes. The proteolytic conversion of fII to α-thrombin (fIIa) by the prothrombinase complex occurs through 2 parallel pathways: (1) the inactive intermediate, prethrombin; or (2) the proteolytically active intermediate, meizothrombin (fIIa(MZ)). FIIa(MZ) has distinct catalytic properties relative to fIIa, including diminished fibrinogen cleavage and increased protein C activation. Thus, fII activation may differentially influence hemostasis and disease depending on the pathway of activation. To determine the in vivo physiologic and pathologic consequences of restricting thrombin generation to fIIa(MZ), mutations were introduced into the endogenous fII gene, resulting in expression of prothrombin carrying 3 amino acid substitutions (R157A, R268A, and K281A) to limit activation events to yield only fIIa(MZ) Homozygous fII(MZ) mice are viable, express fII levels comparable with fII(WT) mice, and have reproductive success. Although in vitro studies revealed delayed generation of fIIa(MZ) enzyme activity, platelet aggregation by fII(MZ) is similar to fII(WT) Consistent with prior analyses of human fIIa(MZ), significant prolongation of clotting times was observed for fII(MZ) plasma. Adult fII(MZ) animals displayed significantly compromised hemostasis in tail bleeding assays, but did not demonstrate overt bleeding. More notably, fII(MZ) mice had 2 significant phenotypic advantages over fII(WT) animals: protection from occlusive thrombosis after arterial injury and markedly diminished metastatic potential in a setting of experimental tumor metastasis to the lung. Thus, these novel animals will provide a valuable tool to assess the role of both fIIa and fIIa(MZ) in vivo.

Factors influencing nurses' readiness to care for hospitalised older people.

AIMS AND OBJECTIVES: To gain a better understanding of nurses' perspectives on factors that influence their readiness to provide appropriate care for hospitalised older people. BACKGROUND: Hospitals have consistently been criticised for failing to address the unique, complex needs of older people. Research suggests that multiple issues have led to this situation, including a lack of educational preparation for nurses, limited attention to environmental factors, and an absence of organisational preparedness that ensures hospitals are adapted to meet the needs of older people. DESIGN: An exploratory, qualitative approach was used. METHODS: Forty-one Registered Nurses participated (24 point-of-care nurses; 17 organisational leaders). Six focus groups and one individual interview were conducted. Thematic data analysis was employed to generate the main study findings. RESULTS: An overarching theme of 'Poor Fit' emerged. While participants identified the shifting needs of patients towards more complex and relational care, the broader organisational and societal contexts were, largely, unchanging. This resulted in nurses recognising the factors needed to be ready to care for older patients and their families, but working in hospitals that were not suited to these needs. CONCLUSIONS: The findings identify factors at the point-of-care, the organisational level, and in broader societal attitudes that shape nurses' readiness to care for hospitalised older people. However, many of these factors are modifiable and care for older people could be improved through quality improvement initiatives and nursing leadership. This study offers insight into ways to re-imagine nursing care that can be responsive to older people's complex needs in hospitals. IMPLICATIONS FOR PRACTICE: With a growing contingent of hospitalised older people, it is imperative that nurses, who comprise the largest workforce in this setting, be included in the planning and delivery of healthcare services to ensure readiness to meet the needs of this population.

Genetic diminution of circulating prothrombin ameliorates multiorgan pathologies in sickle cell disease mice.

Sickle cell disease (SCD) results in vascular occlusions, chronic hemolytic anemia, and cumulative organ damage. A conspicuous feature of SCD is chronic inflammation and coagulation system activation. Thrombin (factor IIa [FIIa]) is both a central protease in hemostasis and a key modifier of inflammatory processes. To explore the hypothesis that reduced prothrombin (factor II [FII]) levels in SCD will limit vaso-occlusion, vasculopathy, and inflammation, we used 2 strategies to suppress FII in SCD mice. Weekly administration of FII antisense oligonucleotide "gapmer" to Berkeley SCD mice to selectively reduce circulating FII levels to ∼10% of normal for 15 weeks significantly diminished early mortality. More comprehensive, long-term comparative studies were done using mice with genetic diminution of circulating FII. Here, cohorts of FII(lox/-) mice (constitutively carrying ∼10% normal FII) and FII(WT) mice were tracked in parallel for a year following the imposition of SCD via hematopoietic stem cell transplantation. This genetically imposed suppression of FII levels resulted in an impressive reduction in inflammation (reduction in leukocytosis, thrombocytosis, and circulating interleukin-6 levels), reduced endothelial cell dysfunction (reduced endothelial activation and circulating soluble vascular cell adhesion molecule), and a significant improvement in SCD-associated end-organ damage (nephropathy, pulmonary hypertension, pulmonary inflammation, liver function, inflammatory infiltration, and microinfarctions). Notably, all of these benefits were achieved with a relatively modest 1.25-fold increase in prothrombin times, and in the absence of hemorrhagic complications. Taken together, these data establish that prothrombin is a powerful modifier of SCD-induced end-organ damage, and present a novel therapeutic target to ameliorate SCD pathologies.

Synthesis and anticoagulant activity of polyureas containing sulfated carbohydrates.

Polyurea-based synthetic glycopolymers containing sulfated glucose, mannose, glucosamine, or lactose as pendant groups have been synthesized by step-growth polymerization of hexamethylene diisocyanate and corresponding secondary diamines. The obtained polymers were characterized by gel permeation chromatography, nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. The nonsulfated polymers showed similar results to the commercially available biomaterial polyurethane TECOFLEX in a platelet adhesion assay. The average degree of sulfation after reaction with SO3 was calculated from elemental analysis and found to be between three and four -OSO3 groups per saccharide. The blood-compatibility of the synthetic polymers was measured using activated partial thromboplastin time, prothrombin time, thrombin time, anti-IIa, and anti-Xa assays. Activated partial thromboplastin time, prothrombin time, and thrombin time results indicated that the mannose and lactose based polymers had the highest anticoagulant activities among all the sulfated polymers. The mechanism of action of the polymers appears to be mediated via an anti-IIa pathway rather than an anti-Xa pathway.

Evaluation of a symptom-triggered protocol approach to the management of alcohol withdrawal syndrome in older adults.

OBJECTIVES: To evaluate whether implementation of symptom-triggered administration of a benzodiazepine protocol reduces the severity (total cumulative dose), duration, and complications of alcohol withdrawal syndrome (AWS). DESIGN: Retrospective health record review. SETTING: Tertiary care center in Vancouver, Canada. PARTICIPANTS: Individuals aged 70 and older admitted to the Acute Care for Elders and Acute Medicine Unit wards with diagnostic codes for AWS from 2008 to 2012. MEASUREMENTS: Median duration and cumulative dose of benzodiazepine treatment, number of severe AWS complications, severe benzodiazepine-associated adverse effects, and need for adjunct therapy. RESULTS: Thirty-three participants in the preprotocol group and 30 in the protocol-implemented group met the inclusion criteria. Median duration of benzodiazepine treatment decreased from 96 hours (interquartile range (IQR) 72-120 hours) in the preprotocol period to 48 hours (IQR 0-108 hours; P=.04), and median cumulative benzodiazepine dose administered decreased from 9 mg (IQR 5-19.8 mg) to 3 mg (IQR 0-10 mg; P=.001). Statistically significantly lower incidence of severe AWS complications (P=.007) and adjunct therapy use (P=.02) was seen in the protocol-implemented group. CONCLUSION: A symptom-triggered protocol for dosing of benzodiazepine therapy in the management of AWS in individuals aged 70 and older significantly reduced the total duration of benzodiazepine use, cumulative benzodiazepine dose, and use of adjunctive medications in the treatment of AWS.

Thrombin drives tumorigenesis in colitis-associated colon cancer.

The established association between inflammatory bowel disease and colorectal cancer underscores the importance of inflammation in colon cancer development. On the basis of evidence that hemostatic proteases are powerful modifiers of both inflammatory pathologies and tumor biology, gene-targeted mice carrying low levels of prothrombin were used to directly test the hypothesis that prothrombin contributes to tumor development in colitis-associated colon cancer (CAC). Remarkably, imposing a modest 50% reduction in circulating prothrombin in fII+/- mice, a level that carries no significant bleeding risk, dramatically decreased adenoma formation following an azoxymethane/dextran sodium sulfate challenge. Similar results were obtained with pharmacologic inhibition of prothrombin expression or inhibition of thrombin proteolytic activity. Detailed longitudinal analyses showed that the role of thrombin in tumor development in CAC was temporally associated with the antecedent inflammatory colitis. However, direct studies of the antecedent colitis showed that mice carrying half-normal prothrombin levels were comparable to control mice in mucosal damage, inflammatory cell infiltration, and associated local cytokine levels. These results suggest that thrombin supports early events coupled to inflammation-mediated tumorigenesis in CAC that are distinct from overall inflammation-induced tissue damage and inflammatory cell trafficking. That prothrombin is linked to early events in CAC was strongly inferred by the observation that prothrombin deficiency dramatically reduced the formation of very early, precancerous aberrant crypt foci. Given the importance of inflammation in the development of colon cancer, these studies suggest that therapeutic interventions at the level of hemostatic factors may be an effective means to prevent and/or impede colitis-associated colon cancer progression.

Geriatric emergency nurses: addressing the needs of an aging population.

INTRODUCTION: Older adults account for up to 14.5% of ED visits. Presentation of older adults can differ from younger adults. Emergency visits by older adults that are characterized by comorbidity, cognitive and functional impairment, and complex social issues. In addition, older adults present with subtle, atypical symptoms making diagnosis and discharge more challenging. The purpose of this study was to describe an innovative geriatric emergency nurse role that has been implemented to address the unique needs of older adults in the emergency department. METHODS: This was an exploratory, descriptive study. The study sample was comprised of two groups: Geriatric Emergency Nurses (N=5) and key informants (N=15). The study was based at a tertiary hospital in Vancouver, Canada. Data was collected using semi-structured interviews. Data were analyzed using thematic analysis. RESULTS: The findings are organized into three sections: defining the role and its functions; a collaborative relationship: fitting in to the larger emergency department; and recommendations for future role development. CONCLUSION: Findings from the study have led to further considerations about the role in relation to communication about older patients both within the emergency department and with community stakeholders. We also discuss the importance of this role in relation to the continuum of care and recognizing the central role of the emergency department as a place for intervention. Lastly, we consider the need for further integration of gerontological knowledge and expertise within the emergency department beyond a specialized role.

Colitis-associated cancer is dependent on the interplay between the hemostatic and inflammatory systems and supported by integrin alpha(M)beta(2) engagement of fibrinogen.

A link between colitis and colon cancer is well established, but the mechanisms regulating inflammation in this context are not fully defined. Given substantial evidence that hemostatic system components are powerful modulators of both inflammation and tumor progression, we used gene-targeted mice to directly test the hypothesis that the coagulation factor fibrinogen contributes to colitis-associated colon cancer in mice. This fundamental provisional matrix protein was found to be an important determinant of colon cancer. Fibrinogen deficiency resulted in a dramatic diminution in the number of colonic adenomas formed following azoxymethane/dextran sodium sulfate challenge. More detailed analyses in mice expressing a mutant form of fibrinogen that retains clotting function, but lacks the leukocyte integrin receptor alpha(M)beta(2) binding motif (Fibgamma(390-396A)), revealed that alpha(M)beta(2)-mediated engagement of fibrin(ogen) is mechanistically coupled to local inflammatory processes (e.g., interleukin-6 elaboration) and epithelial alterations that contribute to adenoma formation. Consistent with these findings, the majority of Fibgamma(390-396A) mice developed no discernable adenomas, whereas penetrance was 100% in controls. Furthermore, the adenomas harvested from Fibgamma(390-396A) mice were significantly smaller than those from control mice and less proliferative based on quantitative analyses of mitotic indices, suggesting an additional role for fibrin(ogen) in the growth of established adenomas. These studies show, for the first time, a unique link between fibrin(ogen) and the development of inflammation-driven malignancy. Given the importance of antecedent inflammation in the progression of numerous cancers, these studies suggest that therapies targeting fibrin(ogen)-alpha(M)beta(2) interactions may be useful in preventing and/or treating this important subset of malignancies.

Genetic elimination of prothrombin in adult mice is not compatible with survival and results in spontaneous hemorrhagic events in both heart and brain.

Mice carrying a conditional prothrombin knockout allele (fII(lox)) were established to develop an experimental setting for exploring the importance of thrombin in the maintenance of vascular integrity, the inflammatory response, and disease processes in adult animals. In the absence of Cre-mediated recombination, homozygous fII(lox/lox) mice or compound heterozygous mice carrying one fII(lox) allele and one constitutive-null allele were viable. Young adults exhibited neither spontaneous bleeding events nor diminished reproductive success. However, the induction of Cre recombinase in fII(lox) mice using the poly I:C-inducible Mx1-Cre system resulted in the rapid and near-complete recombination of the fII(lox) allele within the liver, the loss of circulating prothrombin, and profound derangements in coagulation function. Consistent with the notion that thrombin regulates coagulation and inflammatory pathways, an additional early consequence of reducing prothrombin was impaired antimicrobial function in mice challenged with Staphylococcus aureus peritonitis. However, life expectancy in unchallenged adults genetically depleted of prothrombin was very short ( approximately 5-7 days). The loss of viability was associated with the development of severe hemorrhagic events within multiple tissues, particularly in the heart and brain. Unlike the constitutive loss of either clotting or platelet function alone, the conditional loss of prothrombin is uniformly not compatible with maintenance of hemostasis or long-term survival.