Perspectives on safety culture

Overviewing selected elements from the literature, this paper locates the notion of safety culture within its parent concept of organisational culture. A distinction is drawn between functionalist and interpretive perspectives on organisational culture. The terms ‘culture’ and ‘climate’ are clarified as they are typically applied to organisations and to safety. A contrast is drawn between strategic top down and data-driven bottom up approaches to human factors as an illustrative aspect of safety. A safety case study is used to illustrate two measurement approaches. Key issues for future study include valid measurement of safety culture and developing methods to adequately represent mechanisms through which safety culture might influence, and be influenced by, other safety factors

The influence of adrenergic stimulation on sex differences in left ventricular twist mechanics

Background. Sex differences in LV mechanics exist at rest and during acute physiological stress. Differences in cardiac autonomic and adrenergic control may contribute to sex differences in LV mechanics and LV hemodynamics. Accordingly, this study aimed to investigate sex differences in LV mechanics with altered adrenergic stimulation achieved through post handgrip exercise ischemia (PEI) and ß1-adrenergic receptor (AR) blockade. Methods and Results. 20 males (23±5 yr) and 20 females (22±3 yr) were specifically matched for LV length (males: 8.5±0.5 cm, females: 8.2±0.6 cm, p=0.163), and 2-dimensional speckle-tracking echocardiography was used to assess LV structure and function at baseline, during PEI and following administration of 5mg bisoprolol (ß1-AR antagonist). During PEI, LV end-diastolic volume and stroke volume were increased in both groups (p<0.001), as was end-systolic wall stress (p<0.001). LV twist and apical rotation weren’t altered from baseline or different between the sexes, however basal rotation increased in males (p=0.035). During ß1-AR blockade, LV volumes were unchanged but blood pressure and heart rate were reduced in both groups (p<0.001). LV apical rotation (p=0.036) and twist (p=0.029) were reduced in males with ß1-AR blockade but not females, resulting in lower apical rotation (males: 6.8±2.1º, females: 8.8±2.3º, p=0.007) and twist (males: 8.6±1.9º, females: 10.7±2.8º, p=0.008), and slower untwisting velocity (males: 68.2±22.1º⋅s-1, females: 82.0±18.7º⋅s-1, p=0.046) compared to females. Conclusions. LV twist mechanics are reduced in males compared to females during reductions to adrenergic stimulation, providing preliminary evidence that LV twist mechanics may be more sensitive to adrenergic control in males than in females

Cardiac troponin I levels in canine pyometra

BACKGROUND: Myocardial injury may contribute to unexpected deaths due to pyometra. To detect myocardial damage, measurement of cardiac troponin I (cTnI) is currently the most sensitive and specific method. The aims of the present study were to evaluate presence of myocardial damage in canine pyometra by analysis of cTnI, to explore whether myocardial injury was associated with systemic inflammatory response syndrome (SIRS) and to evaluate whether other clinical or laboratory parameters were associated with cTnI increase. METHODS: Preoperative plasma levels of cTnI were investigated in 58 female dogs with pyometra and 9 controls. The value of physical examination findings, haematological, serum biochemical and pro-inflammatory (CRP and TNF-α) parameters as possible predictors of increased cTnI levels was also evaluated. RESULTS: Seven dogs with pyometra (12%) and one control dog (11%) had increased levels of cTnI. In the pyometra group, the levels ranged between 0.3–0.9 μg l(-1 )and in the control dog the level was 0.3 μg l(-1). The cTnI levels did not differ significantly between the two groups. No cardiac abnormalities were evident on preoperative physical examinations. Four of the pyometra patients died within two weeks of surgery, of which two were examined post mortem. In one of these cases (later diagnosed with myocarditis and disseminated bacterial infection) the cTnI levels increased from 0.9 μg l(-1 )preoperatively to 180 μg l(-1 )the following day when also heart arrhythmia was also detected. The other patient had cTnI levels of 0.7 μg l(-1 )with no detectable heart pathology post mortem. CTnI increase was not associated with presence of SIRS. There was a trend for the association of cTnI increase with increased mortality. No preoperative physical examination findings and few but unspecific laboratory parameters were associated with increased cTnI levels. CONCLUSION: Increased cTnI levels were observed in 12% of the dogs with pyometra. The proportions of dogs with cTnI increase did not differ significantly in the pyometra group compared with the control group. CTnI increase was not associated with presence of SIRS. A trend for association of cTnI increase and mortality was observed. Preoperative physical examination findings and included laboratory parameters were poor predictors of increased cTnI levels

Female Sex Worker Social Networks and STI/HIV Prevention in South China

Reducing harm associated with selling and purchasing sex is an important public health priority in China, yet there are few examples of sustainable, successful programs to promote sexual health among female sex workers. The limited civil society and scope of nongovernmental organizations circumscribe the local capacity of female sex workers to collectively organize, advocate for their rights, and implement STI/HIV prevention programs. The purpose of this study was to examine social networks among low-income female sex workers in South China to determine their potential for sexual health promotion.Semi-structured interviews with 34 low-income female sex workers and 28 health outreach members were used to examine how social relationships affected condom use and negotiation, STI/HIV testing and health-seeking behaviors, and dealing with violent clients. These data suggested that sex worker's laoxiang (hometown social connections) were more powerful than relationships between women selling sex at the same venue in establishing the terms and risk of commercial sex. Female sex workers from the same hometown often migrated to the city with their laoxiang and these social connections fulfilled many of the functions of nongovernmental organizations, including collective mobilization, condom promotion, violence mitigation, and promotion of health-seeking behaviors. Outreach members observed that sex workers accompanied by their laoxiang were often more willing to accept STI/HIV testing and trust local sexual health services.Organizing STI/HIV prevention services around an explicitly defined laoxiang social network may provide a strong foundation for sex worker health programs. Further research on dyadic interpersonal relationships between female sex workers, group dynamics and norm establishment, and the social network characteristics are needed

Cardiac Performance with Chronic Hypoxia: Mechanisms regulating stroke volume

When humans are exposed to high altitude hypoxia for a sustained period, the cardiac stroke volume is reduced. The changes in cardiac performance seen at high altitude are a result of complex and concomitant changes in preload, afterload and contractility, although the precise mechanisms underpinning the decrease in stroke volume are not known despite being of scientific interest for over fifty years. In this review, we briefly revisit the seminal work performed in the area before focusing on recent developments that have applied mechanistic experimental models and novel imaging technologies to further understand why stroke volume is decreased in chronic hypoxia. First, the review focuses on systolic contractile function before considering the role of diastolic function and ventricular filling

FoxP3+ T regulatory cells in cancer : prognostic biomarkers and therapeutic targets

T Regulatory cells (Tregs) can have both protective and pathological roles. They maintain immune homeostasis and inhibit immune responses in various diseases, including cancer. Proportions of Tregs in the peripheral blood of some cancer patients increase by five-to ten-folds, compared to those in healthy individuals. Tregs contribute to cancer development and progression by suppressing T effector cell functions, thereby compromising tumor killing and promoting tumor growth. Highly immunosuppressive Tregs express upregulated levels of the transcription factor, Forkhead box protein P3 (FoxP3). Elevated levels of FoxP3+ Tregs within the tumor microenvironment (TME) showed a positive correlation with poor prognosis in various cancer patients. Despite the success of immunotherapy, including the use of immune checkpoint inhibitors, a significant proportion of patients show low response rates as a result of primary or acquired resistance against therapy. Some of the mechanisms which underlie the development of therapy resistance are associated with Treg suppressive function. In this review, we describe Treg contribution to cancer development/progression, and the mechanisms of Treg-mediated immunosuppression. We discuss the prognostic significance of FoxP3+ Tregs in different cancers and their potential use as prognostic biomarkers. We also describe potential therapeutic strategies to target Tregs in combination with other types of immunotherapies aiming to overcome tumor resistance and improve clinical outcomes in cancer patients. Overall, understanding the prognostic significance of FoxP3+ Tregs in various cancers and their contribution to therapeutic resistance could help in the development of more effective targeted therapeutic strategies to enhance the clinical outcomes in cancer patients

Deformation echocardiography and left ventricular function

La dysfonction ventriculaire gauche reste sous-diagnostiquée en pratique clinique actuelle car les paramètres conventionnels d’échographie ne sont pas suffisamment sensibles pour détecter des modifications fines de la fonction cardiaque. L’introduction récente de l’échocardiographie de suivi des marqueurs acoustiques (speckle tracking echocardiography) a permis par ses capacités descriptives de la mécanique cardiaque, de revisiter la contraction cardiaque et, de ce fait, de proposer une nouvelle approche échographique de l’évaluation de la fonction ventriculaire gauche.<p><p>A travers trois études, nous avons montré que l’analyse des indices de déformation permet d’objectiver des modifications de fonction ventriculaire gauche indétectables en échocardiographie conventionnelle dans des situations complexes à fraction d’éjection conservée, en dépit de l’augmentation modérée de la fréquence cardiaque qui leur est associée. Les situations que nous avons étudiées sont les suivantes :l’adaptation physiologique à l’hypoxie au niveau de la mer et en altitude, et les situations pathologiques que sont le syndrome de mal d’altitude chronique, et la cardiomyopathie associée à l’ataxie de Friedreich.<p><p>L’intégration de nos résultats et des informations disponibles dans la littérature permet de suggérer que l’utilisation de toutes les ressources offertes par l’échocardiographie de suivi des marqueurs acoustiques permet d’améliorer l’évaluation de la fonction cardiaque au-delà de la fraction d’éjection, en offrant une meilleure identification de situations pathologiques mais également une meilleure compréhension de situations physiologiques et pathologiques. <p><p>L’utilisation généralisée des indices de déformation pour l’évaluation de la fonction ventriculaire gauche en pratique clinique connaît néanmoins d’importantes limitations que nous abordons dans la discussion de ce travail. Au terme d’investigations complémentaires et de standardisation de la technique, l’incorporation d’un algorithme d’évaluation échographique de la fonction cardiaque à FEVG conservée combinant les paramètres échographiques conventionnels et les indices de déformation pourra être évalué de façon prospective pour sa translation en pratique clinique, avec pour finalité la proposition d’une définition mieux adaptée de l’insuffisance cardiaque à FEVG conservée.<p>Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe