Monitoring Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention

Dual antiplatelet therapy with aspirin and thienopyridines is the cornerstone in the treatment of patients with acute coronary syndrome (ACS) and in those undergoing PCI with stent-implantation.However, the magnitude of on-treatment platelet reactivity is not uniform among individuals, due to a multifactorial origin including clinical, pharmacologic and genetic factors. Clopidogrel is a prodrug that requires conversion by hepatic P450 isoenzymes to its active metabolite. Most of the clopidogrel (85%) is hydrolyzed by carboxylase to an inactive carboxylic acid metabolite, whereas the remaining 15% is transformed rapidly into its active metabolite that is able to exert its antiplatelet response by irreversibly inhibiting the binding of adenosinediphosphate (ADP) to the P2Y12 receptor. Recently, paraoxonase-1 (PON1) was identified as the crucial enzyme in clopidogrel bioactivation. Consistent findings across multiple investigations support the association between a lower degree of platelet inhibition, i.e. a high on-treatment platelet reactivity (HPR), and an increased risk for the occurrence of thrombo-ischemic events (Table 1).9-14,14,15,15-27 Multiple factors have been associated with high on-treatment platelet reactivity, among which genetic polymorphisms of cytochrome P450 and of the P2Y12 receptor as well as and drug-drug interactions. Consequently, the monitoring of the magnitude of platelet reactivity has gained widespread attention

The relationship between the perception of own locus of control and aggression of adolescent boys

Aggression is increasingly seen in most parts of South African society. Aggressive behaviour of boys in secondary school often results from frustrations caused by perceived high expectations of others regarding the role, locus of control, and personality of boys. Locus of control plays an important role in a person’s perception concerning a situation and possible reactions to what is happening, or should be happening. A 56-item questionnaire, based on Rotter’s “Locus of control” questionnaire, and the DIAS Scale were used. The questionnaire was completed by 440 boys in Grades 9, 10, and 11. Various factor, item and differential statistical analyses were conducted. Three constructs were identified, i.e. physical, verbal, and indirect aggression. Results indicated that locus of control has a significant influence on verbal and indirect aggression. The differential analysis indicated that contextual variables (language of tuition, age, and grade) play a significant, but not substantial, role in aggression. Furthermore, boys with an internal locus of control are significantly and substantially less aggressive than boys with an external locus of control, with respect to physical, verbal and indirect aggression

A Network Perspective on Corporate Entrepreneurship:How Workplace Relationships Influence Entrepreneurial Behavior

Organizations often struggle to maintain or rekindle an entrepreneurial flair, which makes them vulnerable when circumstances change. Corporate entrepreneurship is a process that stimulates entrepreneurial behavior, enabling organizations to respond to changing circumstances, pursue new opportunities, and secure their long-term viability. Prior research has suggested several models that capture the corporate entrepreneurship process and identify a range of factors that stimulate or stifle entrepreneurial behavior. These models greatly improved our understanding of corporate entrepreneurship, but they do not explicitly acknowledge the social context of organizations and employees. In this dissertation, I develop and test a theoretical framework that provides a network perspective on corporate entrepreneurship (the NPCE framework). The NPCE framework shows when and why the social context plays a decisive role in the corporate entrepreneurship process. The results of three empirical studies provide support for the NPCE framework and demonstrate that the social context can evoke entrepreneurial and conservative behavior. The key implication of this finding for future corporate entrepreneurship research is that the omission of the social context leads to an incomplete understanding of the corporate entrepreneurship process

Verbal interaction in mathematics lessons in Anglophone Cameroon.

In 2 volsAvailable from British Library Document Supply Centre- DSC:DX177236 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Analise van stilistiese en strukturele tegnieke in die laat periode van Robert Muczynski met spesifieke verwysing na sy klavierwerk Desperate Measures (1994)

This dissertation discusses the stylistic and structural properties seen in the late compositional period of Polish-American composer Robert Muczynski. The focus falls mainly on his last piano composition, Desperate Measures. The development of musical style in the USA, the creation and development of neo-classicism alongside several stylistic aspects of Muczynski’s music are amongst the topics investigated in the literature review. In the next chapter the possible periodisation of Muczynski’s oeuvre is discussed with emphasis on the identification of a late period. In chapters 3 and 4 a more detailed discussion of Muczynski’s overall style is presented together with a thorough analysis of his use of form structure and his use of stylistic aspects respectively in his composition Desperate Measures. The dissertation is concluded with the researcher’s definition of Muczynski’s late period as well as a discussion of form structural and stylistic elements in Desperate Measures seen as an example of a composition from said period. With the completion of this dissertation the researcher hopes to increase interest in Muczynski’s music in South Africa and to introduce the composer’s work to a larger group of listeners and performers.Dissertation (MMus (Performing Arts))--University of Pretoria, 2019.MusicMMus (Performing Arts)Unrestricte

Change or stability? A meta-analysis of organizational responses to social and historical performance feedback

Performance feedback theory (PFT) proposes that performance shortfalls trigger problemistic search followed by strategic change. However, empirical studies report inconsistent results, suggesting that organizational responses depend on the type of feedback considered and the pathways through which firms attempt to restore performance. To reconcile these conflicting findings, we conducted a meta-analysis of 74 performance feedback studies and integrated PFT with regulatory focus theory to explain when and how organizations respond to performance shortfalls. Our findings show that historical shortfalls (comparisons with a firm's past performance) are associated with strategic change, whereas social shortfalls (comparisons with peers) lead to stability through increased R&amp;D intensity. We also demonstrate that strategic change and R&amp;D intensity represent distinct behavioral outcomes of the feedback process that vary independently rather than unfolding in a fixed sequence. These findings advance PFT by highlighting the differentiated impact of feedback types and provide practical insights for managers seeking to assess the performance of their firms.</p

Duration of dual antiplatelet therapy in acute coronary syndrome

Despite a large volume of evidence supporting the use of dual antiplatelet therapy in patients with acute coronary syndrome, there remains major uncertainty regarding the optimal duration of therapy. Clinical trials have varied markedly in the duration of therapy, both across and within trials. Recent systematic reviews and meta-analyses suggest that shorter durations of dual antiplatelet therapy are superior because the avoidance of atherothrombotic events is counterbalanced by the greater risks of excess major bleeding with apparent increases in all-cause mortality with longer durations. These findings did not show significant heterogeneity according to whether patients had stable or unstable coronary heart disease. Moreover, the potential hazards and benefits may differ when applied to the general broad population of patients encountered in everyday clinical practice who have markedly higher bleeding and atherothrombotic event rates. Clinicians lack definitive information regarding the duration of therapy in patients with acute coronary syndrome and risk scores do not appear to be sufficiently robust to address these concerns. We believe that there is a pressing need to undertake a broad inclusive safety trial of shorter durations of therapy in real world populations of patients with acute coronary syndrome. The clinical evidence would further inform future research into strategies for personalised medicine

Is platelet inhibition due to thienopyridines increased in elderly patients, in patients with previous stroke and patients with low body weight as a possible explanation of an increased bleeding risk?

Background The TRITON-TIMI 38 study has identified three subgroups of patients with a higher risk of bleeding during treatment with the thienopyridine prasugrel: patients with a history of stroke or transient ischaemic attack (TIA), patients ≥75 years and patients with a body weight <60 kg. However, the underlying pathobiology leading to this increased bleeding risk remains to be elucidated. The higher bleeding rate may be due to a stronger prasugrelinduced inhibition of platelet aggregation in these subgroups. The aim of the present study was to determine whether on-treatment platelet reactivity is lower in these risk subgroups as compared with other patients in a large cohort on the thienopyridine clopidogrel undergoing elective coronary stenting. Methods A total of 1069 consecutive patients were enrolled. On-clopidogrel platelet reactivity was measured in parallel by light transmittance aggregometry, the Verify- Now®P2Y12 assay and the PFA-100 collagen/ADP cartridge. Results Fourteen patients (1.5%) had a prior history of stroke or TIA, 138 patients (14.5%) were older than 75 years and 30 patients (3.2%) had a body weight <60 kg. Age ≥75 years and a history of stroke were independent predictors of a higher on-treatment platelet reactivity. In contrast, a body weight <60 kg was significantly associated with a lower on-treatment platelet reactivity. Conclusion In two high-risk subgroups for bleeding, patients ≥75 years and patients with previous stroke, onclopidogrel platelet reactivity is increased. In contrast, in patients with a low body weight, on-clopidogrel platelet reactivity is decreased, suggesting that a stronger response to a thienopyridine might only lead to more bleeds in patients with low body weight

Chronic substance use and self-harm in a primary health care setting

Background: Chronic substance use (CSU) is associated with health problems, including selfharm, placing a significant burden on health care resources and emergency departments (EDs). This is problematic in low- and middle-income countries like South Africa (SA), where primary care facilitates and emergency departments (EDs) are often poorly resourced. Aim: To investigate the epidemiology of CSU and self-harm and to consider the implications for primary health care service delivery and suicide prevention in SA. Methods: Data were collected from 238 consecutive self-harm patients treated at the emergency department (ED) of an urban hospital in SA. The data were analysed using bivariate and multivariate analyses. Results: Approximately 37% of self-harm patients reported CSU. The patients in the CSU subgroup, compared to other self-harm patients, were more likely to be men (odds ratio[OR] = 8.33, 95% confidence interval [CI] = 3.19–20.9, p < 0.001), to have self-harmed by inflicting damage to their body tissue OR = 4.45, 95% CI = 1.77–11.2, p < 0.01) and to have a history of self-harm (OR = 3.71, 95% CI = 1.44–9.54, p = 0.007). A significantly smaller proportion of CSU patients, compared to other self-harm patients, were referred for psychiatric assessment (OR = 8.05, 95% CI = 4.16–15.7, p < 0.001). Conclusion: The findings of this study confirm that CSU is associated with greater service utilisation and repetition of self-harm among patients in primary health care settings. Treating self-harm as the presenting problem within primary care settings does not necessarily ensure that patients receive the care that they need. It might be helpful to include psychiatric assessments and screening for CSU as an integral component of care for self-harm patients who present in primary health care settings

Substance use and self-harm: a cross-sectional study of the prevalence, correlates and patterns of medical service utilisation among patients admitted to a South African hospital

Abstract Background Substance use is a potentially modifiable risk factor for suicidal behaviour. Little is known about the epidemiology of substance use among self-harm patients in South Africa. This study set out to collect epidemiological data about the prevalence, correlates, and patterns of medical service utilisation among self-harm patients who used substances at the time of self-injury. Methods Data from 238 consecutive self-harm patients treated at an urban hospital in South Africa were analysed using bivariate and multivariate statistics. Results Approximately 20% of patients reported substance use at the time of self-harm. When compared to other self-harm patients, higher rates of patients who had used substances: had depressed levels of consciousness on admission; utilised more medical resources and required longer hospital admissions; cited relationship difficulties and financial concerns as reasons for their self-harm; reported a previous episode of self-harm; and intended to die as a result of their injuries. Although the observed differences were not statistically significant (p > 0.05), the proportional differences were congruent with international literature. Conclusion Acute use of substances among self-harm patients warrants more focused research and clinical attention particularly in the context of reducing utilisation of scarce medical resources