Biomedical subjects

K Hänecke

Publications and source records attributed to K Hänecke.

7 recordsLinked to original sources

PubMed2001

Flexible working time systems--the process of design and implementation.

Examples of the design and implementation processes of flexible working time systems are derived from a counselling project in North Rhine-Westphalia, Germany. The practical cases shown represent a diversity of variable or flexible working time systems according to different branches and different anticipated aims to reach with flexibility. For companies flexibility should improve or at least consolidate their economic situation, and for employees flexibility should result in a beneficial effect on health, family and social life. Three examples of counselling practice are reported in this paper, each case representing a different approach to flexibility in working time. To avoid overtime an industrial production plant expanded the weekly operating time without increasing the employees working time. For this purpose shifts off had to be planned. To provide a continuous service one department of a service company changed from duty on call to regular shifts on weekends. Responsibility in handling the new working times was assigned to the team. In an old people's home working times were designed according to the irregular demands throughout the day, in combining full and part-time jobs adequately.

Choice Behavior↗

PubMed1998

Accident risk as a function of hour at work and time of day as determined from accident data and exposure models for the German working population.

OBJECTIVES: Recent studies indicate that accident risk may be a function of hour at work and time of day. Further evidence was sought for these assumptions, along with the answer to the question of whether the risk of accident can be conceived as an interaction between hours at work and time of day. METHODS: Data on more than 1.2 million accidents for the year 1994 were provided, all listed according to the time of day and hour at work. Since information about how long each day and at what time of day people work is not available in Germany, different exposure models had to be estimated. For estimating the risk of having an accident relative accident risks were calculated from the ratio of accident frequencies to the exposure data. RESULTS: An exponentially increasing accident risk was observed beyond the 9th hour at work. The relative accident risks differed considerably according to the respective exposure model with regard to time of day. A highly significant interaction effect was found for hour at work by time of day, the percentage of accidents at different hours at work varying according to the particular time of day when work is started. For the 3 "traditional" shiftwork starting times, it was shown that, with later starting times, the relative accident risk increased dramatically beyond the 8th hour at work. CONCLUSIONS: Since the results clearly indicate that there are time-related effects on occupational accident risk, more detailed analyses are called for. More elaborated exposure models should be used to assess the efficiency of work schedules with extended workhours, especially under shiftwork conditions. The results also indicate the necessity of recording and providing adequate data bases for such analyses.

Accidents, Occupational↗

PubMed1997

The C-terminal domain of the human EP4 receptor confers agonist-induced receptor desensitization in a receptor hybrid with the rat EP3beta receptor.

Prostaglandin E2 receptors (EPR), which belong to the family of heterotrimeric G protein-coupled ectoreceptors with seven transmembrane domains, can be classified into four subtypes according to their ligand binding and G protein coupling specificity. Of these, EP3betaR is coupled to Gi, whereas EP4R is coupled to Gs. EP4R, in contrast to EP3betaR, shows agonist-induced desensitization. The C-terminal domain and the third intracellular loop of these receptors have been implicated in G protein coupling specificity and desensitization. Here, receptor hybrids consisting of the main portion of rat EP3betaR and either the C-terminal domain or the third intracellular loop of human EP4R were used to study the contribution of the respective receptor domains to G protein coupling and desensitization. Neither the EP4R C-terminal domain nor the EP4R third intracellular loop alone was sufficient to change the coupling specificity of the rEP3hEP4 receptor hybrids from Gi to Gs or to confer additional Gs coupling. However, the EP4R C-terminal domain but not the third intracellular loop was necessary and sufficient to mediate rapid agonist-induced, second messenger-independent desensitization in the Gi-coupled hybrid receptors.

Alprostadil↗

PubMed1997

The C-terminal domain of the Gs-coupled EP4 receptor confers agonist-dependent coupling control to Gi but no coupling to Gs in a receptor hybrid with the Gi-coupled EP3 receptor.

Prostaglandin E2 receptors (EPR) belong to the family of G-protein-coupled receptors with 7 transmembrane domains. They form a family of four subtypes, which are linked to different G-proteins. EP1R are coupled to Gq, EP2 and EP4R to Gs and EP3R to Gi. Different C-terminal splice variants of the bovine EP3R are coupled to different G-proteins. A mouse EP3R whose C-terminal domain had been partially truncated no longer showed agonist-induced Gi-protein activation and was constitutively active. In order to test the hypothesis that the C-terminal domain confers coupling specificity of the receptors on the respective G-proteins, a cDNA for a hybrid rEP3hEP4R, containing the N-terminal main portion of the Gi-coupled rat EP(3beta)R including the 7th transmembrane domain and the intracellular C-terminal domain of the Gs-coupled human EP4R, was generated by PCR. HEK293 cells transiently transfected with the chimeric rEP3hEP4R cDNA expressed a plasma membrane PGE2 binding site with a slightly lower Kd value for PGE2 but an identical binding profile for receptor-specific ligands as cells transfected with the native rat EP(3beta)R. In HepG2 cells stably transfected with the chimeric rEP3hEP4R cDNA PGE2 did not increase cAMP formation characteristic of Gs coupling but attenuated the forskolin-stimulated cAMP synthesis characteristic of Gi coupling. This effect was inhibited by pre-treatment of the cells with pertussis toxin. Thus, the hybrid receptor behaved both in binding and in functional coupling characteristics as the native rat EP(3beta)R. Apparently, the intracellular C-terminal domain did not confer coupling specificity but coupling control, i.e. allowed a signalling state of the receptor only with agonist binding.

Animals↗

PubMed1994

Molecular cloning and expression of a prostaglandin E2 receptor of the EP3 beta subtype from rat hepatocytes.

Rat hepatocytes have previously been reported to possess prostaglandin E2 receptors of the EP3-type (EP3-receptors) that inhibit glucagon-stimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP3 beta receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95% homology to the EP3 beta receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE2 with an apparent Kd of 15 nM. PGE2 > PGF2 alpha > PGD2 competed for [3H]PGE2 binding sites as did the EP3 receptor agonists M&B 28767 = sulprostone > misoprostol but not the EP1 receptor antagonist SC 19220. In stably transfected CHO cells M&B 28767 > sulprostone = PGE2 > misoprostol > PGF2 alpha inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP3 beta receptor of rat hepatocytes closely resemble those of the EP3 beta receptor of mouse mastocytoma.

Amino Acid Sequence↗

PubMed1994

Prostaglandin F2 alpha and D2 release from primary Ito cell cultures after stimulation with noradrenaline and ATP but not adenosine.

Rat liver Ito cells were cultured for 24 hr with 20% newborn calf serum. Stimulation with the sympathetic neurotransmitter noradrenaline (0.1 mumol/L to 1 mmol/L) led to a dose-dependent increase in prostaglandin F2 alpha release and a slightly smaller enhancement of prostaglandin D2 production. Prostaglandin F2 alpha and prostaglandin D2 synthesis was highest in the first 30 sec after stimulation. Stimulation with the possible cotransmitter ATP (10 mumol/L and 1 mmol/L ATP) also enhanced both prostaglandin F2 alpha and prostaglandin D2 release strongly. The release was highest again during the first 30 sec. Stimulation with noradrenaline and ATP simultaneously did not increase the effects of noradrenaline or ATP alone. Adenosine had no effect on prostaglandin production. The effects of noradrenaline were inhibited specifically by the alpha 1-adrenoreceptor antagonist prazosin but not by the p1-purinoreceptor antagonist 8-phenyltheophylline. The effects of ATP were not antagonized by the inhibitors. Because the metabolic actions of sympathetic hepatic nerves can be inhibited by inhibitors of prostanoid synthesis and mimicked by prostaglandins F2 alpha and D2, and because the Ito cells are well innervated, our results permit the conclusion that Ito cells could be involved in the nervous signal chain: During sympathetic nerve action the neurotransmitter noradrenaline and the cotransmitter ATP cause increases in prostaglandin F2 alpha and prostaglandin D2 release from Ito cells within 30 to 60 sec by way of alpha 1 and p2 receptors, respectively. The released prostaglandins then activate glycogenolysis in the hepatocytes proper.

Adenosine↗

PubMed1988

Common free time of family members under different shift systems.

The amount and the chronological position of common free time of fathers under different shift systems with their children of different ages is analysed for reasons for explaining deficiencies in the school career of children of shiftworking fathers. It is shown that the amount of common free time is interactively determined by the particular form of the fathers' shift schedules and the timetables of their children. Shiftworkers have smaller amounts of common free time at their disposal for contacts with schoolgoing children than dayworkers, but within the group of shiftworkers the amount of common free time explains only a small proportion of the variance in the shiftworkers, evaluations of their interpersonal relations to their children.

Journal Article↗