1 Buprenorphine is a highly lipophilic derivative of oripavine. In rodent antinociceptive assays (writhing, tail pressure), buprenorphine had an action which was rapid in onset and of long duration; it was 25‐40 times more potent than morphine after parenteral injection and 7‐10 times more potent after oral administration. 2 The log dose‐response relationship for buprenorphine was curvilinear in mouse and rat tail flick tests with the antinociceptive effect decreasing at higher, non‐toxic doses. 3 Tolerance developed to the antinociceptive activity of buprenorphine in mice. 4 No signs of abstinence were observed on naloxone challenge or after abrupt withdrawal in monkeys receiving buprenorphine chronically for one month. 5 Buprenorphine antagonized the antinociceptive actions of morphine in mouse and rat tail flick tests but was an ineffective antagonist in the rat tail pressure test. 6 Buprenorphine precipitated signs of abstinence in morphine‐dependent mice and monkeys but not in morphine‐dependent rats. 7 Buprenorphine produced Straub tails in mice. This effect was not antagonized when the animals were pretreated with naloxone. However, in the rat tail pressure test high doses of diprenorphine antagonized established antinociceptive effects of buprenorphine. 8 It is concluded that buprenorphine represents a definite advance in the search for a narcotic antagonist analgesic of low physical dependence potential.

This paper aims to examine the information requirements and the importance of various types of information for potential students when selecting a university. Using data from 306 pupils studying at various schools in England, Scotland and Northern Ireland seven broad information categories relating to university selection have been identified. It also revealed that the ranking of the various types of information required and the importance of this information is relatively similar.

Buprenorphine is a mixed agonist-antagonist with high affinity at both mu and kappa opiate receptors. Its pharmacological profile is determined primarily by partial agonism at mu-receptors and unusually slow kinetics at these receptors. Its intrinsic activity is such that in nearly all clinical situations it is as effective an analgesic as morphine with considerably longer duration and much more favourable acute safety. In long-term dosing studies in rodents and primates buprenorphine did not produce the manifestations of physical dependence when treatment was stopped. In self-administration studies in the same species only limited levels of reinforcing efficacy were demonstrated when compared with the opiates. In human former opiate addicts the limited potential of buprenorphine to produce psychological dependence was confirmed as was the favourable physical dependence profile. Some misuse of buprenorphine has been reported in 3 of the 29 countries in which buprenorphine is marketed despite its wide clinical acceptance, particularly as the sublingual formulation.

No abstract

733potential, steep towards the Pb 2+ ions, flat towards the unoccupied center of the elementary cell. Our investigations do not show a difference in the potentials towards the nearest F-neighbours ((110) and (100) directions), but these potentials are clearly steeper than in the (l 1 l) directions towards the center of the elementary cell.Our investigations demonstrate that elastic X-ray diffraction data allow refinements of anharmonic temperature factors up to sixth order for the Pb 2+ ions. These temperature factors and the corresponding p.d.f. maps allow the determination of one-particle potentials, which can be used to study the thermal vibrations of the Pb 2+ ions in arbitrary directions. AbstractThe charge density in ~-A1203 has been refined with respect to X-ray structure factors [complete spheres for both Mo Ka and Ag Kt~ radiations with (sin 0/2)m,x = 1.19 and 1.495,/k -~ respectively] and electric-fieldgradient tensors at both atomic sites, using Hirshfeldtype deformation functions. Atomic charges from a x refinement are + 1.32 (5) for AI and -0.88 (8) e for O. The charge distribution of O is polarized towards the four A1 neighbours, and metal-metal bonds are clearly absent. Quadrupole coupling constants and asymmetry parameters of the field-gradient tensors cannot be determined from the structure factors. They define the quadrupolar deformations near the atomic centers, and the X-ray data define the charge density between the atoms. The orientational parameters of the tensors and the signs of their largest eigenvalues can be qualitatively retrieved from the X-ray data. The 0567-7394/82/050733-07501.00 refinement of anisotropic secondary-extinction parameters may, however, destroy this information. Refinement with respect to the field gradients affects mainly the quadrupolar deformation terms, and has little influence on the X-ray scale factor (i.e. monopolar terms) and computed electrostatic fields (i.e. dipolar terms). Properties of the charge density with different angular symmetries are thus only weakly correlated.