omega-Hydroxylation of leukotriene B4 (LTB4) has been reported in human and rodent polymorphonuclear leukocytes; preliminary information indicates that this metabolism is cytochrome P-450 dependent. Therefore, these studies were initiated to characterize the cytochrome P-450-dependent metabolism of LTB4 in other tissues. LTB4 was metabolized by rat hepatic microsomes to two products, 20-hydroxy...

These findings could be interpreted as implying that the enhancement by carcinogens in vitro of hamster hepatic microsomal biphenyl 2-hydroxylase (McPherson ‘et al., 19746) is mediated through an effect on the microsomal membrane rather than via direct specific conformational modification of the biphenyl 2-hydroxylase enzyme itself. In an attempt to differentiate between the soluble and microso...

A potent inhibitor of microsomal mixed-function oxidation reactions in insects had previously been isolated and partially purified from the gut contents of Prodenia eridania and shown to be associated with proteinase activity. Incubation of rat liver microsomal fraction with low concentrations of this inhibitor led to solubilization of NADPH-cytochrome c reductase, which was paralleled by the i...

Policy change has eroded the entitlement of UK residents to free state-provided health care, with a resulting rise in the use of the private sector. This paper examines the choice between public and private health care. It models the use of private health care as a function of its costs and benefits relative to state care and no care. The results indicate a difference between users of private c...

Public confidence in clinical trials has been eroded by data suppression, misrepresentation and manipulation. Although various attempts have been made to achieve universal trial registration- e.g., Declaration of Helsinki, WHO clinical Trial Registry Platform (WHO ICTRP), the International Committee of Medical Journal Editors requirement- they have not succeeded, probably because they lack the ...

There is significant archaeological evidence marking the collapse of the Shijiahe culture in the middle reaches of the Yangtze River in China during the late Neolithic Period. However, the causes for this cultural collapse remain unclear. Our sedimentary records from a 3.3 m long profile and 76 phytolith and charcoal samples from the Tanjialing archaeological sites provide records of interactio...

In the Axelrod's model of cultural dissemination, we consider the mobility of cultural agents through the introduction of a density of empty sites and the possibility that agents in a dissimilar neighborhood can move to them if their mean cultural similarity with the neighborhood is below some threshold. While for low values of the density of empty sites, the mobility enhances the convergence t...

New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Fo...