A mixed-methods investigation of health professionals' perceptions of a physiological track and trigger system.

BACKGROUND: Physiological track and trigger systems (PTTSs) regulate the monitoring of patients' vital signs and facilitate the detection and treatment of deteriorating patients. These systems are widely used, although compliance with protocol is often poor. OBJECTIVE: This study aimed to examine the perceptions of a national PTTS among nurses and doctors and to identify the variables that impact on intention to comply with protocol. METHODS: A mixed-methods research design was employed. During the initial qualitative phase, 30 hospital-based nurses and doctors participated in a series of semistructured interviews. During the subsequent quantitative phase, 215 nurses and doctors (24.1% response rate) responded to a questionnaire designed to assess attitudes towards the PTTS and factors that influence adherence to protocol. RESULTS: Interview data revealed largely positive attitudes towards the PTTS but highlighted a number of barriers to its implementation and indicated that it is sometimes a source of tension between doctors and nurses. Quantitative data confirmed the validity of these findings, although nurses appeared to have more positive attitudes towards, and to perceive fewer barriers to, the usage of PTTS than were reported by the participating doctors. CONCLUSIONS: These findings reveal that non-compliance with PTTS protocol is unlikely to be attributable to negative perceptions of PTTSs. Instead, there are a number of barriers to the implementation of the system. These findings suggest that interprofessional training in PTTSs is essential while increased support for PTTS implementation among senior doctors would also yield improved adherence to protocol.

Regulation of human trophoblast migration and invasiveness.

The human placenta is an invasive structure in which highly proliferative, migratory, and invasive extravillous trophoblast (EVT) cells migrate and invade the uterus and its vasculature. Using in vitro propagated normal first-trimester EVT cells and immortalized EVT cells, which share all of the phenotypic and functional characteristics of the normal EVT cells, it has been shown that migration/invasion of human EVT cells is stringently regulated by many growth factors, their binding proteins, extracellular matrix (ECM) components, and some adhesion molecules in an autocrine/paracrine manner at the fetal-maternal interface in human pregnancy. Transforming growth factor beta (TGF-beta), decorin (a proteoglycan in the ECM), and melanoma cell adhesion molecule (Mel-CAM) inhibit, and insulin-like growth factor II (IGF-II), IGF-binding protein 1 (IGFBP-1), and endothelin 1 (ET-1) stimulate EVT cell migration/invasion. Inhibition of EVT cell migration by TGF-beta has been suggested to be due to upregulation of integrins, which make the cells more adhesive to the ECM. Its antiinvasive action is due to an upregulation of tissue inhibitor of matrix metalloprotease 1 (TIMP-1) and plasminogen activator inhibitor (PAI-1) and a downregulation of urokinase-type plasminogen activator (uPA). Molecular mechanisms of inhibition of migration/invasion of EVT cells by decorin and Mel-CAM remain to be identified. IGF-II action has been shown to be mediated by IGF type I receptors (IGF-RII) independently of IGF type I receptors (IGF-RI) and IGFBPs. This action of IGF-II appears to involve inhibitory G proteins and phosphorylation of mitogen-activated protein kinase (MAPK) (extracellular signal-regulated protein kinases 1 and 2 (ERK-1 and ERK-2)). IGFBP-1 stimulation of EVT cell migration appears to occur by binding its Arg-Gly-Asp (RGD) domain to alpha5beta1 integrin, leading to phosphorylation of focal adhesion kinase (FAK) and MAPK (ERK-1 and ERK-2). These studies may improve our understanding of diseases related to abnormal placentation, viz. hypoinvasiveness in preeclampsia and hyperinvasiveness in trophoblastic neoplasms.