Enacting ethics: bottom-up involvement in implementing moral case deliberation.

In moral case deliberation (MCD), healthcare professionals meet to reflect upon their moral questions supported by a structured conversation method and non-directive conversation facilitator. An increasing number of Dutch healthcare institutions work with MCD to (1) deal with moral questions, (2) improve reflection skills, interdisciplinary cooperation and decision-making, and (3) develop policy. Despite positive evaluations of MCD, organization and implementation of MCD appears difficult, depending on individuals or external experts. Studies on MCD implementation processes have not yet been published. The aim of this study is to describe MCD implementation processes from the perspective of nurses who co-organize MCD meetings, so called 'local coordinators'. Various qualitative methods were used within the framework of a responsive evaluation research design. The results demonstrate that local coordinators work hard on the pragmatic implementation of MCD. They do not emphasize the ethical and normative underpinnings of MCD, but create organizational conditions to foster a learning process, engagement and continuity. Local coordinators indicate MCD needs firm back-up from management regulations. These pragmatic action-oriented implementation strategies are as important as ideological reasons for MCD implementation. Advocates of clinical ethics support should pro-actively facilitate these strategies for both practical and ethical reasons.

Client participation in moral case deliberation: a precarious relational balance.

Moral case deliberation (MCD) is a form of clinical ethics support in which the ethicist as facilitator aims at supporting professionals with a structured moral inquiry into their moral issues from practice. Cases often affect clients, however, their inclusion in MCD is not common. Client participation often raises questions concerning conditions for equal collaboration and good dialogue. Despite these questions, there is little empirical research regarding client participation in clinical ethics support in general and in MCD in particular. This article aims at describing the experiences and processes of two MCD groups with client participation in a mental healthcare institution. A responsive evaluation was conducted examining stakeholders' issues concerning client participation. Findings demonstrate that participation initially creates uneasiness. As routine builds up and client participants meet certain criteria, both clients and professionals start thinking beyond 'us-them' distinctions, and become more equal partners in dialogue. Still, sentiments of distrust and feelings of not being safe may reoccur. Client participation in MCD thus requires continuous reflection and alertness on relational dynamics and the quality of and conditions for dialogue. Participation puts the essentials of MCD (i.e., dialogue) to the test. Yet, the methodology and features of MCD offer an appropriate platform to introduce client participation in healthcare institutions.

Homo- and heterotetrameric architecture of the epithelial Ca2+ channels TRPV5 and TRPV6.

The molecular assembly of the epithelial Ca(2+) channels (TRPV5 and TRPV6) was investigated to determine the subunit stoichiometry and composition. Immunoblot analysis of Xenopus laevis oocytes expressing TRPV5 and TRPV6 revealed two specific bands of 75 and 85-100 kDa, corresponding to the core and glycosylated proteins, respectively, for each channel. Subsequently, membranes of these oocytes were sedimented on sucrose gradients. Immuno blotting revealed that TRPV5 and TRPV6 complexes migrate with a mol. wt of 400 kDa, in line with a tetrameric structure. The tetrameric stoichiometry was confirmed in an electrophysiological analysis of HEK293 cells co-expressing concatemeric channels together with a TRPV5 pore mutant that reduced Cd(2+) sensitivity and voltage-dependent gating. Immuno precipitations using membrane fractions from oocytes co-expressing TRPV5 and TRPV6 demonstrated that both channels can form heteromeric complexes. Expression of all possible heterotetrameric TRPV5/6 complexes in HEK293 cells resulted in Ca(2+) channels that varied with respect to Ca(2+)-dependent inactivation, Ba(2+) selectivity and pharmacological block. Thus, Ca(2+)-transporting epithelia co-expressing TRPV5 and TRPV6 can generate a pleiotropic set of functional heterotetrameric channels with different Ca(2+) transport kinetics.

A slow outward current and a hypoosmolality induced anion conductance in embryonic chicken osteoclasts.

In this paper we report on a hypoosmolality induced current, I(osmo), in embryonic chicken osteoclasts, which could only be studied when blocking a simultaneously active, unidentified slow outward current, I(slo). I(slo) was observed in all of the examined cells when both the intracellular and extracellular solutions contained sodium as the major cation and no potassium. The current was outwardly rectifying and activated at membrane potentials more positive than -44 +/- 12 mV (n = 31). The time to half activation of the current was also voltage dependent and was 350 ms at Vm = +80 mV, and 78 ms at Vm = +120 mV. The current did not inactivate during periods up to 5 s. Extracellular 4-AP (5 mM), TEA (5 mM) and Ba2+ (1 mM), blockers of K+ conductances in chicken osteoclasts, did not influence I(slo). However, I(slo) was inhibited by 50 microM extracellular verapamil, which allowed us to study I(osmo) in isolation. Exposure of the osteoclasts to hypotonic solution resulted in the development of a depolarization activated I(osmo). It developed after a 1-min delay and reached its maximum within 10 minutes. Half-maximal activation occurred after 4.4 +/- 0.9 min (n = 9). The current activated within a few ms upon depolarization and did not inactivate during at least 5 sec. I(osmo) reversed around the calculated Nernst potential for Cl- (E(Cl) = +7.3 mV and V(rev) = +5.4 +/- 3.6 mV, n = 9). The underlying conductance, G(osmo) exhibited moderate outward rectification around 0 mV in symmetrical Cl- solutions. Ion substitution experiments showed that G(osmo) is an anion conductance with P(Cl) approximately = P(F) > P(gluc) >> P(Na). I(osmo) was blocked by 0.5 mM SITS but 50 microM verapamil, 5 mM TEA, 5 mM 4-AP, 1 mM Ba2+, 50 microM cytochalasin D and 0.5 mM alendronate did not have any effect on the current. Cl- currents have been implicated in charge neutralization during osteoclastic acid secretion for bone resorption. The present results imply that osmolality may be a factor controlling this charge neutralization.

The effects of glutamate on membrane potential and discharge rate of suprachiasmatic neurons.

The suprachiasmatic nucleus (SCN) is a major pacemaker for circadian rhythms in mammals. Photic entrainment of the circadian pacemaker is mediated by the retinohypothalamic tract (RHT). Most likely, excitatory amino acids function as neurotransmitters in this pathway. We have now investigated the effect of glutamate on the membrane potential of cultured SCN cells of the rat with the aid of the patch clamp technique. It was found that 1 mM glutamate depolarizes the cells by about +44 mV. In spontaneously active neurons, the glutamate induced depolarization caused either an increase in discharge or a depolarization block. We then investigated the effect of 1 mM glutamate on SCN discharge in the acutely prepared hypothalamic slice of the hamster. In most cells glutamate induced an increase in discharge whilst in a few cells discharge was suppressed. Both series of experiments indicate that glutamate in the used dosage was effective and its effect reversible. The data are discussed with respect to the failure of 1 mM glutamate injections to mimic the effect of light on the circadian activity rhythm of the hamster.

Ionic channels and membrane hyperpolarization in human macrophages.

Microelectrode impalement of human macrophages evokes a transient hyperpolarizing response (HR) of the membrane potential. This HR was found to be dependent on the extracellular concentration of K+ but not on that of Na+ or Cl-. It was not influenced by low temperature (12 degrees C) or by 0.2 mM ouabain, but was blocked by 0.2 mM quinine or 0.2 mM Mg2+-EGTA. These findings indicate that the HR in human macrophages is caused by the activation of a K+ (Ca2+) conductance. Two types of ionic channels were identified in intact cells by use of the patch-clamp technique in the cell-attached-patch configuration, low and high-conductance voltage-dependent K+ channels. The low-conductance channels had a mean conductance of 38 pS with Na+-saline and 32 pS with K+-saline in the pipette. The high-conductance channels had a conductance of 101 and 114 pS with Na+- and K+-saline in the pipette, respectively. Cell-attached patch measurements made during evocation of an HR by microelectrode penetration showed enhanced channel activity associated with the development of the HR. These channels were also high-conductance channels (171 pS with Na+- and 165 pS K+-saline in the pipette) and were voltage dependent. They were, however, active at less positive potentials than the high-conductance K+ channels seen prior to the microelectrode-evoked HR. It is concluded that the high-conductance voltage-dependent ionic channels active during the HR in human macrophages contribute to the development of the HR.