Application of a poly(4-styrenesulfonate) liquid binding layer for measurement of Cu2+ and Cd2+ with the diffusive gradients in thin-films technique.

A diffusive gradients in thin films (DGT) technique for measuring Cd and Cu is described using, for the first time, a liquid phase binding layer and a dialysis membrane diffusive layer. The binding phase was a 0.020 M solution of poly(4-styrenesulfonate) (PSS) polyelectrolyte using a specially designed DGT deployment device.

Evaluation of the diffusive gradient in a thin film technique for monitoring trace metal concentrations in estuarine waters.

Monitoring trace metal concentrations in dynamic estuarine waters is not straightforward. This study demonstrated that important information could be obtained from intensive sampling of physicochemical parameters and trace metal concentrations, in the Gold Coast Broadwater, Australia. A regular pattern of variation in Cu and Ni concentrations was related to the movement of water passed point sources with tidal flows, rather than due to conventional estuarine mixing of end-member waters.

Recent strategies in the search for new anti-influenza therapies.

Influenza is a highly contagious, acute upper respiratory tract disease caused by influenza virus, a member of the Orthomyxoviridae family. The viral particles have two surface antigens, haemagglutinin and sialidase (neuraminidase) that extensively decorate the surface of the virus and have been implicated in viral attachment and fusion, and the release of virion progeny, respectively. The receptor for haemagglutinin is the terminal sialic acid residue of host cell surface sialyloligosaccharides, while sialidase catalyses the hydrolysis of terminal sialic acid residues from sialyloligosaccharides.

Adenosine-mediated early preconditioning in mouse: protective signaling and concentration dependent effects.

Objectives: Signaling in adenosine-mediated preconditioning is controversial. We examined roles of mitochondrial (mito) K(ATP) channels, protein kinase C (PKC) and nitric oxide (NO).

Methods: Langendorff perfused C57/Bl6 mouse hearts were subjected to 20 min ischemia and 45 min reperfusion.

Effects of A1 adenosine receptor overexpression on normoxic and post-ischemic gene expression.

Objectives: To identify potential molecular genetic determinants of cardiovascular ischemic tolerance in wild-type and transgenic hearts overexpressing A(1) adenosine receptors (A(1)ARs).

Methods: cDNA microarrays were used to explore expression of 1824 genes in wild-type hearts and ischemia-tolerant mouse hearts overexpressing A(1)ARs.

Results: Overexpression of A(1)ARs reduced post-ischemic contractile dysfunction, limited arrhythmogenesis, and reduced necrosis by approximately 80% in hearts subjected to 30 min global ischemia 60 min reperfusion.

Pyruvate-dependent preconditioning and cardioprotection in murine myocardium.

1. Whether pyruvate inhibits or can actually initiate myocardial preconditioning is unclear and whether pyruvate provides protection via its action as a 'cosubstrate' with glucose or via alternative mechanisms also remains controversial. We examined effects of a high concentration of pyruvate (10 mmol/L) alone or with 15 mmol/L glucose in mouse hearts subjected to 20 min ischaemia and 30 min reperfusion.

Adenosine receptor subtypes mediating coronary vasodilation in rat hearts.

Adenosine receptor-mediated coronary vasodilation was studied in isolated hearts from young (1-2 months) and mature (12-18 months) Wistar rats. The nonselective agonist 5'-N-ethylcarboxamidoadenosine (NECA) induced biphasic concentration-dependant dilation with similar potencies in both age groups (p < 0.05).

Receptor and non-receptor-dependent mechanisms of cardioprotection with adenosine.

The relative roles of mitochondrial (mito) ATP-sensitive K(+) (mitoK(ATP)) channels, protein kinase C (PKC), and adenosine kinase (AK) in adenosine-mediated protection were assessed in Langendorff-perfused mouse hearts subjected to 20-min ischemia and 45-min reperfusion. Control hearts recovered 72 +/- 3 mmHg of ventricular pressure (50% preischemia) and released 23 +/- 2 IU/g lactate dehydrogenase (LDH). Adenosine (50 microM) during ischemia-reperfusion improved recovery (149 +/- 8 mmHg) and reduced LDH efflux (5 +/- 1 IU/g).

Coronary function and adenosine receptor-mediated responses in ischemic-reperfused mouse heart.

Objectives: To assess the impact of ischemia-reperfusion (I/R) on coronary function, and the role of endogenous adenosine in modifying post-ischemic vascular function in asanguinous hearts.

Methods: Vascular function was studied in Langendorff perfused mouse hearts subjected to 20-25-min ischemia and 30-min reperfusion.

Results: Ischemia altered the dependence of flow on work-rate observed in normoxic hearts, and inhibited reflow by mechanisms additional to diastolic compression.

Australian hospital generalist and critical care nurses' perceptions of doctor-nurse collaboration.

Previous researchers have indicated that collaborative practice between doctors and nurses results in positive effects on patient care, health-care costs and provider satisfaction. Despite these benefits, collaborative practice appears to be the exception, rather than the dominant pattern, within health care. A collaborative relationship cannot evolve if individuals do not value and respect others' competencies.

Adherence of Burkholderia pseudomallei cells to cultured human epithelial cell lines is regulated by growth temperature.

We have investigated the adherence of Burkholderia pseudomallei, cultured under a number of different conditions, to six human epithelial cell lines. While several complex medium compositions had relatively little effect on adherence, growth at 30 degrees C was found to significantly increase adherence to all cell lines relative to that of cultures grown at 37 degrees C (P < 0.001).

Effects of A(3) adenosine receptor activation and gene knock-out in ischemic-reperfused mouse heart.

Objectives: To characterize effects of A(3) adenosine receptor (A(3)AR) activation and gene knock-out on responses to ischemia-reperfusion in mouse heart.

Methods: Perfused hearts from wild-type and A(3)AR gene knock-out (A(3)AR KO) mice were subjected to 20 min ischemia and 30 min reperfusion. Functional responses were assessed and changes in energy metabolism and cytosolic pH monitored via 31P-NMR spectroscopy.

Adenosine-mediated cardioprotection in ischemic-reperfused mouse heart.

We investigated the roles of A1, A2A, or A3 receptors and purine salvage in cardioprotection with exogenous adenosine, and tested whether A2A -mediated reductions in perfusion pressure modify post-ischemic recovery. Treatment with 10(-5) or 5 x 10(-5) M adenosine improved contractile recovery from 20 min ischemia 45 min reperfusion in isolated mouse hearts. Protection was attenuated by adenosine kinase inhibition (10(-5) M iodotubercidin) and receptor antagonism (5 x 10(-5) M 8-rho-sulfophenyltheophylline, 8-SPT).

Functional properties and responses to ischaemia-reperfusion in Langendorff perfused mouse heart.

Despite minimal model characterisation Langendorff perfused murine hearts are increasingly employed in cardiovascular research, and particularly in studies of myocardial ischaemia and reperfusion. Reported contractility remains poor and ischaemic recoveries variable. We characterised function in C57/BL6 mouse hearts using a ventricular balloon or apicobasal displacement and assessed responses to 10-30 min global ischaemia.

5'-Adenosine monophosphate and adenosine metabolism, and adenosine responses in mouse, rat and guinea pig heart.

We examined myocardial 5'-adenosine monophosphate (5'-AMP) catabolism, adenosine salvage and adenosine responses in perfused guinea pig, rat and mouse heart. MVO(2) increased from 71+/-8 microl O(2)/min per g in guinea pig to 138+/-17 and 221+/-15 microl O(2)/min per g in rat and mouse. VO(2)/beat was 0.

Synthesis and biological evaluation of sialylmimetics as rotavirus inhibitors.

Rotaviruses cause severe gastroenteritis in infants and are estimated to be responsible for over 600 000 deaths annually, primarily in developing countries. The development of potential inhibitors of this virus is therefore of great interest, particularly since the safety and efficacy of rotaviral vaccines has recently been questioned. This study describes the synthesis of a variety of compounds that can be considered as mimetics of N-acetylneuraminic acid thioglycosides and the subsequent in vitro biological evaluation of these sialylmimetics as inhibitors of rotaviral infection.

Cardioprotection with adenosine metabolism inhibitors in ischemic-reperfused mouse heart.

Objectives: To characterize the 'anti-ischemic' effects of adenosine metabolism inhibition in ischemic-reperfused myocardium.

Methods: Perfused C57/B16 mouse hearts were subjected to 20 min ischemia 40 min reperfusion in the absence or presence of adenosine deaminase inhibition (50 microM erythro-2-(2-hydroxy-3-nonyl)adenine; EHNA) adenosine kinase inhibition (10 microM iodotubercidin; IODO), or 10 microM adenosine. Hearts overexpressing A(1) adenosine receptors (A(1)ARs) were also studied.

Cohesion among nurses: a comparison of bedside vs. charge nurses' perceptions in Australian hospitals.

Aim: This study examines the extent to which hospital nurses view their working environment in a positive sense, working as a cohesive group.

Background: Despite the fact that nursing in Australia is now considered a profession, it has been claimed that nurses are an oppressed group who use horizontal violence, bullying and aggression in their interactions with one and other.

Methods: After ethical approval, a random sample of 666 nurses working directly with patients and all 333 critical care nurses employed in three large tertiary Australian hospitals were invited to participate in the study in the late 1990s.

Age-related changes in adenosine-mediated relaxation of coronary and aortic smooth muscle.

We tested whether adenosine mediates nitric oxide (NO)-dependent and NO-independent dilation in coronary and aortic smooth muscle and whether age selectively impairs NO-dependent adenosine relaxation. Responses to adenosine and the relatively nonselective analog 5'-N-ethylcarboxamidoadenosine (NECA) were studied in coronary vessels and aortas from immature (1-2 mo), mature (3-4 mo), and moderately aged (12-18 mo) Wistar and Sprague-Dawley rats. Adenosine and NECA induced biphasic concentration-dependent coronary vasodilation, with data supporting high-sensitivity (pEC(50) = 5.

Factors influencing job valuation: a comparative study of critical care and non-critical care nurses.

This study sought to identify the relationship between three predictor variables, perceived collaboration with medical staff, autonomy and independent actions and an outcome, the value hospital nurses placed on their work. In total 189 critical care and 366 non-critical care nurses completed a mailed survey. Critical care nurses perceived themselves to have a more collaborative relationship with the medical staff, described performing actions independent of medical orders more frequently and perceived their jobs to have more value than non-critical care nurses.

Intrinsic A(1) adenosine receptor activation during ischemia or reperfusion improves recovery in mouse hearts.

We assessed the role of A(1) adenosine receptor (A(1)AR) activation by endogenous adenosine in the modulation of ischemic contracture and postischemic recovery in Langendorff-perfused mouse hearts subjected to 20 min of total ischemia and 30 min of reperfusion. In control hearts, the rate-pressure product (RPP) and first derivative of pressure development over time (+dP/dt) recovered to 57 +/- 3 and 58 +/- 3% of preischemia, respectively. Diastolic pressure remained elevated at 20 +/- 2 mmHg (compared with 3 +/- 1 mmHg preischemia).

Cardioprotection by K(ATP) channels in wild-type hearts and hearts overexpressing A(1)-adenosine receptors.

We studied the role of mitochondrial ATP-sensitive K(+) (K(ATP)) channels in modifying functional responses to 20 min global ischemia and 30 min reperfusion in wild-type mouse hearts and in hearts with approximately 250-fold overexpression of functionally coupled A(1)-adenosine receptors (A(1)ARs). In wild-type hearts, time to onset of contracture (TOC) was 303 +/- 24 s, with a peak contracture of 89 +/- 5 mmHg. Diastolic pressure remained elevated at 52 +/- 6 mmHg after reperfusion, and developed pressure recovered to 40 +/- 6% of preischemia.

A high-throughput assay for rat liver golgi and Saccharomyces cerevisiae-expressed murine CMP-N-acetylneuraminic acid transport proteins.

Rat liver Golgi and Saccharomyces cerevisiae-expressed CMP-Neu5Ac transport protein were reconstituted in phosphatidylcholine liposomes and transport of CMP-Neu5Ac into these proteoliposomes was determined. The separation of transported substrate from free substrate was performed using Multiscreen minicolumns loaded with Sephadex G-50 resin (fine). The CMP-Neu5Ac transport characteristics of the rat liver Golgi and S.