Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

Fas (CD95/Apo-1) ligand is a potent inducer of apoptosis and one of the major killing effector mechanisms of cytotoxic T cells. Thus, Fas ligand activity has to be tightly regulated, involving various transcriptional and post-transcriptional processes. For example, preformed Fas ligand is stored in secretory lysosomes of activated T cells, and rapidly released by degranulation upon reactivation. In this study, we analyzed the minimal requirements for activation-induced degranulation of Fas ligand. T cell receptor activation can be mimicked by calcium ionophore and phorbol ester. Unexpectedly, we found that stimulation with phorbol ester alone is sufficient to trigger Fas ligand release, whereas calcium ionophore is neither sufficient nor necessary. The relevance of this process was confirmed in primary CD4(+) and CD8(+) T cells and NK cells. Although the activation of protein kinase(s) was absolutely required for Fas ligand degranulation, protein kinase C or A were not involved. Previous reports have shown that preformed Fas ligand co-localizes with other markers of cytolytic granules. We found, however, that the activation-induced degranulation of Fas ligand has distinct requirements and involves different mechanisms than those of the granule markers CD63 and CD107a/Lamp-1. We conclude that activation-induced degranulation of Fas ligand in cytotoxic lymphocytes is differently regulated than other classical cytotoxic granule proteins.

Social Work as Laboratory for Normative Professionalisation

In most Western countries, the professional status of social workers is instable and insecure. Of course, most Western countries are themselves instable, ridden with feelings of insecurity and in search of reassurance and promises of control. But social work hardly lends itself as a projection screen for visions of professional control and efficiency in the face of insecurity. On the contrary: within the present cultural and political climate, social work connotes primarily with unpopular social problems, with people unable to cope adequately with the competitiveness and the rate of change of post-industrial societies, that is to say: it connotes more with dependency and helplessness then with autonomy and control. Moreover, whereas public discourse in most Western country is dominated by a neo-liberal perspective and the intricate network of economic, managerial, consumerist and military metaphors connected with it, social work still carries with it a legacy of 'progressive politics' increasingly labeled as outdated and inadequate. Although the values of solidarity and social justice connected with this 'progressive heritage' certainly have not faded away completely, the loudest and most popular voices on the level of public discourse keep underscoring the necessity to adapt to the 'realities' of present-day postindustrial societies and their dependence on economic growth, technological innovation and the dynamics of an ever more competitive world-market. This 'unavoidable' adaptation involves both the 'modernization' and progressive diminishment of 'costly' welfare-state arrangements and a radical reorientation of social work as a profession. Instead of furthering the dependency of clients in the name of solidarity, social workers should stimulate them to face their own responsibilities and help them to function more adequately in a world where individual autonomy and economic progress are dominant values. This shift has far-reaching consequences for the organization of the work itself. Efficiency and transparency are the new code words, professional autonomy is dramatically limited and interventions of social workers are increasingly bound to 'objective' standards of success and cost-effectiveness.

Fulfilled and missed requirements for online reservation systems: an empirical investigation of Austrian and Swiss hotels

Temporal data are a core element of a reservation. In this paper we formulate 10 requirements and 14 sub-requirements for handling temporal data in online hotel reservation systems (OHRS) from a usability viewpoint. We test the fulfillment of these requirements for city and resort hotels in Austria and Switzerland. Some of the requirements are widely met; however, many requirements are fulfilled only by a surprisingly small number of hotels. In particular, numerous systems offer options for selecting data which lead to error messages in the next step. A few screenshots illustrate flaws of the systems. We also draw conclusions on the state of applying software engineering principles in the development of Web pages.

Normative MR Cervical Spinal Canal Dimensions

Purpose To provide normal values of the cervical spinal canal and spinal cord dimensions in several planes with respect to spinal level, age, sex, and body height. Materials and Methods This study was approved by the institutional review board; all individuals provided signed informed consent. In a prospective multicenter study, two blinded raters independently examined cervical spine magnetic resonance (MR) images of 140 healthy volunteers who were white. The midsagittal diameters and areas of spinal canal and spinal cord, respectively, were measured at the midvertebral levels of C1, C3, and C6. A multivariate general linear model described the influence of sex, body height, age, and spinal level on the measured values. Results There were differences for sex, spinal level, interaction between sex and level, and body height, while age had significant yet limited influence. Normative ranges for the sagittal diameters and areas of spinal canal and spinal cord were defined at C1, C3, and C6 levels for men and women. In addition to a calculation of normative ranges for a specific sex, spinal level, age, and body height data, data for three different height subgroups at 45 years of age were extracted. These results show a range of the spinal canal dimensions at C1 (from 10.7 to 19.7 mm), C3 (from 9.4 to 17.2 mm), and C6 (from 9.2 to 16.8 mm) levels. Conclusion : The dimensions of the cervical spinal canal and cord in healthy individuals are associated with spinal level, sex, age, and height. © RSNA, 2013 Online supplemental material is available for this article.