Predictive factors for home deaths among cancer patients in Swedish palliative home care

Five palliative home care teams participated in a prospective Swedish study that included 221 palliative cancer patients. All patients with incurable malignant disease that were admitted and died during 1999 were included. On admission, demographic data were recorded. When patients, despite ongoing home care, were referred to institutional care, doctors and nurses involved were interviewed about the reasons for this. After the patients' death next of kin involved in the care were interviewed according to a questionnaire. Approximately half of the patients died at home. The reasons for referral showed a wide diversity and included both social and psychosocial factors, medical emergencies and problems related to symptom control. A preference for dying at home and not living alone were shown to be the strongest predictors of home death (p = 0.001). However, 35% of patients living alone died at home. Interestingly enough, Karnofsky performance index (KPI) at admission was significantly lower for those dying at home, despite similar mean time of care. The understanding of impending death was significantly more common among the families of those patients dying at home.

Activation of EphA2 kinase suppresses integrin function and causes focal-adhesion-kinase dephosphorylation

Interactions between receptor tyrosine kinases of the Eph family and their ligands, ephrins, are implicated in establishment of organ boundaries and repulsive guidance of cell migration during development, but the mechanisms by which this is achieved are unclear. Here we show that activation of endogenous EphA2 kinase induces an inactive conformation of integrins and inhibits cell spreading, migration and integrin-mediated adhesion. Moreover, EphA2 is constitutively associated with focal-adhesion kinase (FAK) in resting cells. Within one minute after stimulation of EphA2 with its ligand, ephrin-A1, the protein tyrosine phosphatase SHP2 is recruited to EphA2; this is followed by dephosphorylation of FAK and paxillin, and dissociation of the FAK-EphA2 complex. We conclude that Eph kinases mediate some of their functions by negatively regulating integrins and FAK.

Dynamic interaction of PTPmu with multiple cadherins in vivo

There is a growing body of evidence to implicate reversible tyrosine phosphorylation as an important mechanism in the control of the adhesive function of cadherins. We previously demonstrated that the receptor protein tyrosine phosphatase PTPmu associates with the cadherin-catenin complex in various tissues and cells and, therefore, may be a component of such a regulatory mechanism (Brady-Kalnay, S. M., D.L. Rimm, and N.K. Tonks. 1995. J. Cell Biol. 130:977- 986). In this study, we present further characterization of this interaction using a variety of systems. We observed that PTPmu interacted with N-cadherin, E-cadherin, and cadherin-4 (also called R-cadherin) in extracts of rat lung. We observed a direct interaction between PTPmu and E-cadherin after coexpression in Sf9 cells. In WC5 cells, which express a temperature-sensitive mutant form of v-Src, the complex between PTPmu and E-cadherin was dynamic, and conditions that resulted in tyrosine phosphorylation of E-cadherin were associated with dissociation of PTPmu from the complex. Furthermore, we have demonstrated that the COOH-terminal 38 residues of the cytoplasmic segment of E-cadherin was required for association with PTPmu in WC5 cells. Zondag et al. (Zondag, G., W. Moolenaar, and M. Gebbink. 1996. J. Cell Biol. 134: 1513-1517) have asserted that the association we observed between PTPmu and the cadherin-catenin complex in immunoprecipitates of the phosphatase arises from nonspecific cross-reactivity between BK2, our antibody to PTPmu, and cadherins. In this study we have confirmed our initial observation and demonstrated the presence of cadherin in immunoprecipitates of PTPmu obtained with three antibodies that recognize distinct epitopes in the phosphatase. In addition, we have demonstrated directly that the anti-PTPmu antibody BK2 that we used initially did not cross-react with cadherin. Our data reinforce the observation of an interaction between PTPmu and E-cadherin in vitro and in vivo, further emphasizing the potential importance of reversible tyrosine phosphorylation in regulating cadherin function.

A mechanism for trabecular meshwork cell retraction: ethacrynic acid initiates the dephosphorylation of focal adhesion proteins

Ethacrynic acid (ECA) increases aqueous humor outflow facility in human and animal model systems, and causes cellular retraction in cultured trabecular meshwork (TM) cells. ECA-induced retraction, a possible correlate to the opening of spaces in the outflow pathway in vivo, takes place coincident with disruption of cell-cell attachments and actin stress fibers. Tyrosine phosphorylated proteins are located predominantly where actin filaments terminate at sites of cell-to-cell and cell-to-substrate adhesion, and are understood to regulate cellular adhesions and filamentous (F) actin organization in many cell types. In the present study we investigated whether ECA might affect cell adhesions and F-actin in TM cells by altering levels of phosphotyrosine. We analysed levels of phosphotyrosine in cultured human TM and calf pulmonary artery endothelial cells after exposure to ECA. Using immunoflourescence microscopy and antibodies to phosphotyrosinated proteins we found a rapid decrease in phosphotyrosine levels at the focal contacts of cells treated with ECA. Immunoblots of whole cell extracts showed a decrease in phosphotyrosine predominantly in a band running at about 120 kD, with a more subtle decrease in a band about 65 kD. Reprobing the blot with antibodies to pp120 focal adhesion kinase (FAK) or paxillin indicated that the 120 kD band was FAK and the 65 kD band was likely paxillin. Immunoprecipitation of FAK or paxillin and probing the resulting blot with antibodies to phosphotyrosine confirmed that these proteins were rapidly dephosphorylated after ECA addition. Loss of FAK and paxillin proteins in cells was then confirmed using immunofluorescence microscopy. Dephosphorylation of these proteins was detected before the onset of retraction, stress fiber disruption, or complete disruption of focal adhesions. A pure microtubule inhibitor (colchicine), did not cause stress fiber disruption or decrease focal adhesion phosphorylation. We postulate that dephosphorylation of FAK and paxillin by ECA disrupts signaling pathways that normally maintain the stability of the actin cytoskeleton and cellular adhesions, and that this action leads both to cell shape change in culture, and to facility changes in vivo.

Drug treatment of panic disorder: the comparative efficacy of imipramine, alprazolam, and trazodone

Data from 74 patients with panic disorder were evaluated to determine the comparative efficacy of imipramine, alprazolam, and trazodone. All patients were treated with placebo for 3 weeks and were then blindly switched to active treatment for 8 weeks. Both imipramine and alprazolam were highly effective in reducing the symptoms of generalized anxiety, the frequency of panic attacks, and phobic avoidance. However, the time course of these effects differed; alprazolam demonstrated therapeutic properties during the first week, whereas the therapeutic efficacy of imipramine was not clearly apparent until the fourth week of treatment. Relative to imipramine and alprazolam, trazodone was not an effective treatment for panic disorder and was poorly tolerated; only 17 trazodone-treated patients completed at least 4 weeks of treatment, and only 2 patients were considered good or complete responders. These findings support the hypotheses that drugs that are efficacious in the treatment of panic disorders act by altering noradrenergic function and that drugs with primary actions on serotonin function are likely to be less effective treatments. The different time courses of therapeutic action of imipramine and alprazolam indicate that these drugs ameliorate panic anxiety via different mechanisms. The possible therapeutic applications of this observation are discussed.