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BackgroundPartnership type is a determinant of STI risk; yet, it is poorly and inconsistently recorded in clinical practice and research. We identify a novel, empirical-based categorisation of partnership type, and examine whether reporting STI diagnoses varies by the resulting typologies.MethodsAnalyses of probability survey data collected from 15 162 people aged 16–74 who participated in Britain's third National Survey of Sexual Attitudes and Lifestyles were undertaken during 2010–2012. Computer-assisted self-interviews asked about participants' ≤3 most recent partners (N=14 322 partners/past year). Analysis of variance and regression tested for differences in partnership duration and perceived likelihood of sex again across 21 ‘partnership progression types’ (PPTs) derived from relationship status at first and most recent sex. Multivariable regression examined the association between reporting STI diagnoses and partnership type(s) net of age and reported partner numbers (all past year).ResultsThe 21 PPTs were grouped into four summary types: ‘cohabiting’, ‘now steady’, ‘casual’ and ‘ex-steady’ according to the average duration and likelihood of sex again. 11 combinations of these summary types accounted for 94.5% of all men; 13 combinations accounted for 96.9% of all women. Reporting STI diagnoses varied by partnership-type combination, including after adjusting for age and partner numbers, for example, adjusted OR: 6.03 (95% CI 2.01 to 18.1) for men with two ‘casual’ and one ‘now steady’ partners versus men with one ‘cohabiting’ partner.ConclusionsThis typology provides an objective method for measuring partnership type and demonstrates its importance in understanding STI risk, net of partner numbers. Epidemiological research and clinical practice should use these methods and results to maximise individual and public health benefit.

We describe the development of cell-permeable β-secretase inhibitors that demonstratively inhibit the production of the secreted amino terminal fragment of an artificial amyloid precursor protein in cell culture. In addition to potent inhibition in a cell-based assay (IC50 < 100 nM), these inhibitors display impressive selectivity against other biologically relevant aspartyl proteases.

This paper explores the relationship between spatial structure and spatial interaction at the intraurban level. To examine this relationship an experimental framework is designed based on the application of a doubly constrained entropy-type gravity model to journey-to-work data for twenty-four Canadian urban areas. The study demonstrates that distance-decay exponents are strongly influenced by geographic structure and the geometry of origins and destinations. As such, both the influence of map pattern and the friction of distance should be explicitly incorporated into spatial interaction models. The paper also explores the impact of city size and the nature of the economic base of the urban area upon distance-decay exponents.

The metabolism and covalent binding of 4-ipomeanol (IPO), a pulmonary toxin, were investigated in pulmonary cells isolated from rabbit. 3H-labeled IPO was incubated with freshly, isolated, intact alveolar type II cells (83% purity), nonciliated bronchiolar epithelial (Clara) cells (77% purity) and alveolar macrophages (greater than 90% purity). Covalent binding of radioactive material to type II and Clara cells was observed by autoradiography and by a biochemical method. IPO binding to cells was almost totally prevented by 1 mM piperonyl butoxide, an inhibitor of the cytochrome P-450-dependent metabolism of IPO. No covalent binding was observed with alveolar macrophages in the presence or absence of piperonyl butoxide. The maximal rates of enzyme-mediated covalent binding of IPO to protein were greater in the Clara cells (135 pmol/10(6) cells/min) than in the type II cells (13 pmol/10(6) cells/min). Incubation of either sonicated Clara or type II cell fractions with [3H]IPO, glutathione and NADPH (20 min, 37 degrees C) resulted in the formation of two distinct radiolabeled glutathione conjugates.

An investigation of several pathways for xenobiotic metabolism in rat lung cells was carried out using enriched fractions of alveolar type II cells (80% purity) and Clara cells (50% purity) which had been prepared from either untreated (control) rats or animals which had been treated with beta-naphthoflavone. Monooxygenase activities (7-ethoxycoumarin deethylase; aryl hydrocarbon [benzo(a)pyrene] hydroxylase) and activities of conjugating enzymes (glutathione transferase; glucuronosyl transferase) were found to be much higher in fractions enriched in Clara cells than in either the crude cell digest or in fractions enriched in type II cells. This was also found to be true for epoxide hydrolase activity. beta-Naphthoflavone treatment of animals was found to increase the monooxygenase and glucuronosyl transferase activities in all cell fractions, but no effect was seen on either glutathione transferase or epoxide hydrolase activity, each of which was extremely low in type II cells.

In a carefully conducted experiment pupils of certain schools in Cleveland are tuning in on arithmetic. Good results have already been noted. The greatest advantage, in the view of the superintendent, is that the very best instruction can be shared by every classroom.