University of Graz

About: University of Graz is a education organization based out in Graz, Steiermark, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 17934 authors who have published 37489 publications receiving 1110980 citations. The organization is also known as: Carolo Franciscea Graecensis & Karl Franzens Universität.

Antibodies to merkel cell polyomavirus T antigen oncoproteins reflect tumor burden in merkel cell carcinoma patients.

Abstract: Merkel cell polyomavirus (MCPyV) is a common infectious agent that is likely involved in the etiology of most Merkel cell carcinomas (MCC). Serum antibodies recognizing the MCPyV capsid protein VP1 are detectable at high titer in nearly all MCC patients and remain stable over time. Although antibodies to the viral capsid indicate prior MCPyV infection, they provide limited clinical insight into MCC because they are also detected in more than half of the general population. We investigated whether antibodies recognizing MCPyV large and small tumor-associated antigens (T-Ag) would be more specifically associated with MCC. Among 530 population control subjects, these antibodies were present in only 0.9% and were of low titer. In contrast, among 205 MCC cases, 40.5% had serum IgG antibodies that recognize a portion of T-Ag shared between small and large T-Ags. Among cases, titers of T-Ag antibodies fell rapidly (! 8-fold per year) in patients whose cancer did not recur, whereas they rose rapidly in those with progressive disease. Importantly, in several patients who developed metastases, the rise in T-Ag titer preceded clinical detection of disease spread. These results suggest that antibodies recognizing T-Ag are relatively specifically associated with MCC, do not effectively protect against disease progression, and may serve as a clinically useful indicator of disease status. Cancer Res; 70(21); 8388‐97. ©2010 AACR.

Impact of TASK-1 in Human Pulmonary Artery Smooth Muscle Cells

Abstract: The excitability of pulmonary artery smooth muscle cells (PASMC) is regulated by potassium (K+) conductances. Although studies suggest that background K+ currents carried by 2-pore domain K+ channels are important regulators of resting membrane potential in PASMC, their role in human PASMC is unknown. Our study tested the hypothesis that TASK-1 leak K+ channels contribute to the K+ current and resting membrane potential in human PASMC. We used the whole-cell patch-clamp technique and TASK-1 small interfering RNA (siRNA). Noninactivating K+ current performed by TASK-1 K+ channels were identified by current characteristics and inhibition by anandamide and acidosis (pH 6.3), each resulting in significant membrane depolarization. Moreover, we showed that TASK-1 is blocked by moderate hypoxia and activated by treprostinil at clinically relevant concentrations. This is mediated via protein kinase A (PKA)-dependent phosphorylation of TASK-1. To further confirm the role of TASK-1 channels in regulation of resting membrane potential, we knocked down TASK-1 expression using TASK-1 siRNA. The knockdown of TASK-1 was reflected by a significant depolarization of resting membrane potential. Treatment of human PASMC with TASK-1 siRNA resulted in loss of sensitivity to anandamide, acidosis, alkalosis, hypoxia, and treprostinil. These results suggest that (1) TASK-1 is expressed in human PASMC; (2) TASK-1 is hypoxia-sensitive and controls the resting membrane potential, thus implicating an important role for TASK-1 K+ channels in the regulation of pulmonary vascular tone; and (3) treprostinil activates TASK-1 at clinically relevant concentrations via PKA, which might represent an important mechanism underlying the vasorelaxing properties of prostanoids and their beneficial effect in vivo.

Perception of store attributes and overall attitude towards grocery retailers: The role of shopping motives

Abstract: Motivational forces are commonly accepted to have a key influencing role in the explanation of shopping behaviour. In retailing research, shopping motives are a field of research that has received considerable attention, often in combination with motivation-based shopper taxonomies. While personal shopping motives and perceived shopping alternatives are often considered independent inputs into a choice model, we argue that shopping motives influence the perception of retail store attributes as well as the attitude towards retail stores. An empirical study, which was carried out in Germany with 560 grocery shoppers as respondents to test these assumptions, showed that the influence of shopping motives is much more profound on the attitude towards retail stores than towards the perception of store attributes, which might be explained by different levels of abstraction and, consequently, subjectivity in the interpretation of these stimuli.

The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera.

Abstract: The essential oils of Artemisia afra Jacq., Artemisia abyssinica Schultz-Bip. and Juniperus procera Hoechst ex Endl. were examined for their potential radical scavenging activities. First a rapid evaluation of antioxidants was made using a TLC screening method. The abilities of the volatile oils to act as nonspecific donors for hydrogen atoms or electrons were checked in the diphenylpicrylhydrazyl assay. Oils from all three species showed positive results and were examined further. The oils of A. afra and J. procera were also effective hydroxyl radical scavenging agents when assessed in the deoxyribose degradation assay, whilst oils from A. abyssinica exhibited a paradoxical effect. In the in vitro assay for non-enzymatic lipid peroxidation in liposomes, the oils of A. afra and J. procera also displayed antioxidant potential. It was not possible to measure the effect of A. abyssinica oil in this system because certain components, e.g. alk-2-enals, interfered with the assay. The compounds that contribute to the radical scavenging activities of A. afra and J. procera were identified and then assessed for their effects in the various test systems. Finally, the qualitative and quantitative compositions of the essential oils were studied by GC-MS.