Radioimmunoassay for leukotriene E4. Use for determination of total sulfidopeptide-leukotriene release from rat gastric mucosa

A conjugate of leukotriene (LT) E4 and bovine serum albumin (BSA) was prepared by covalently linking the free amino group of the hapten to the protein using dimethyl pimelindiimidate (DMP) as coupling reagent. Anti-LTE4 antibodies were raised in rabbits immunized with the conjugate. Binding of [3H]LTE4 to the antibodies is inhibited by 50% with 0.63 ng LTE4, while the relative cross-reaction of LTC4 and LTD4 is 46.3% and 12.6%, respectively. Using the radioimmunoassay release of sulfidopeptide-LT (SP-LT) from rat gastric mucosa incubated in vitro was determined after quantitative enzymatic conversion of SP-LT to LTE4. It could be demonstrated that this method is suitable for determination of SP-LT in biological material.     

Short-term effects of controlled mating and selection on the genetic variance of honeybee populations

Directional selection in a population yields reduced genetic variance due to the Bulmer effect. While this effect has been thoroughly investigated in mammals, it is poorly studied in social insects with biological peculiarities such as haplo-diploidy or the collective expression of traits. In addition to the natural adaptation to climate change, parasites, and pesticides, honeybees increasingly experience artificial selection pressure through modern breeding programs. Besides selection, many honeybee breeding schemes introduce controlled mating. We investigated which individual effects selection and controlled mating have on genetic variance. We derived formulas to describe short-term changes of genetic variance in honeybee populations and conducted computer simulations to confirm them. Thereby, we found that the changes in genetic variance depend on whether the variance is measured between queens (inheritance criterion), worker groups (selection criterion), or both (performance criterion). All three criteria showed reduced genetic variance under selection. In the selection and performance criteria, our formulas and simulations showed an increased genetic variance through controlled mating. This newly described effect counterbalanced and occasionally outweighed the Bulmer effect. It could not be observed in the inheritance criterion. A good understanding of the different notions of genetic variance in honeybees, therefore, appears crucial to interpreting population parameters correctly.Subject terms: Bioinformatics, Genetic models, Quantitative trait, Animal breeding, Genetic variation     

A Sorrow Shared is a Sorrow Halved: The Search for Empathetic Understanding of Family Members of a Person with Early-Onset Dementia

In this article, I explore how family members of a person with early-onset dementia in the Netherlands attempt to achieve empathetic understanding from significant others, and the barriers they encounter in the process. Based on qualitative interviews, I show that the type of relationship shapes the choices people have to communicate their suffering and their expectations regarding the reactions of others. This article builds on theoretical work on empathy and problematises the notion of shared experiences. It focuses on empathy between family members and significant others, arguing that empathetic understanding between these people is a field of study thus far insufficiently explored.     

cAMP-dependent protein kinase I, a unique allosteric enzyme

cAMP-dependent protein kinases are known to be activated by dissociation. There are two types of these enzymes in the mammalian cytosol with similar catalytic subunits but regulatory subunits. With enzymes of type I, ATP counteracts the activation by cAMP. Recent studies of the binding sites of these enzymes for these ligands are reviewed.