Ethical issues in the diagnostic genetic testing process

The diagnostic genetic testing process has certain unique ethical features and deserves special consideration. The purpose of this study was to determine through empirical research, using focussed interview, what ethical issues are involved in the diagnostic genetic testing process. This article describes views and perceptions of adult patients, parents of child patients and various personnel groups (n=30). The ethical issues were analysed classified into three main categories: a) personnel characteristics, including personality, professional skills, morals and values; b) realization of ethical principles in the examination process, with subcategories of knowledge, autonomy, data protection and equity; and c) consequences of genetic testing, including patients' control over their own lives, manifestation of heterogeneity and outlook on the world. Problematic ethical issues in all three main categories were described in a more many-sided way by parents and personnel than by adult patients. In the future, attention should be paid to the content areas highlighted by the study, in both clinical practice and further studies.     

An unknown mechanism promotes somatic incompatibility in Ceratobasidium bicorne

Strains of Ceratobasidium bicorne (anamorph uninucleate Rhizoctonia), causing root dieback in nursery-grown conifer seedlings, were fruited in the laboratory and the pairing interactions among sibling, single-basidiospore progeny were investigated. No mating reactions were observed. Instead, a high frequency of somatic incompatibility was observed in progeny pairings, indicated by a killing reaction in hyphal anastomosis and by formation of a demarcation line. The F1 progeny also could be fruited, and the level of somatic incompatibility within the F2 progeny remained high, even if lower than in the F1 progeny. The interaction types in pairings within a family of progeny were similar in all respects to those between field isolates, indicating that the species is homothallic. The uninucleate condition of vegetative cells and the basidial characteristics would indicate homokaryotic fruiting, but the possibility of pseudohomothallism remains. We currently are not able to provide an explanation for the mechanism promoting somatic incompatibility in this species, but it seems likely that the classic heterogenic model of somatic incompatibility recognized in basidiomycetes is not applicable here. Alternative mechanisms are discussed.     

Reproductive allocation in Daphnia exposed to toxic cyanobacteria

We investigated experimentally how resources were allocated to reproduction in Daphnia pulex and Daphnia longispina when varying levels of toxic Microcystis were added to higher quality food. We used multiple regression models to estimate mean offspring size and clutch size in relation to maternal size and clutch number, and analysed effects of treatments on residuals from the models. We also measured variation in per offspring investment. At a high cyanobacterial level, D.pulex was virtually unable to reproduce. At a lower level, D.pulex produced small clutches. However, the regression model residuals indicated that the presence of cyanobacteria increased the portion of available resources allocated to reproduction. The observed allocation may be a means to maximize reproduction under diminished longevity. Effects on mean offspring size were marginal in D.pulex but variation in per offspring investment sometimes decreased in cyanobacterial exposures. Daphnia longispina was affected by a higher cyanobacterial level only, where offspring sized was reduced. Deviations from the regression model indicated that effects on maternal size alone do not explain this effect. Clutch size residuals and per offspring investment were unaffected by treatments in D.longispina. The observed responses differ from theoretical models on reproductive allocation under food imitation.      

Phenothiazines and structurally related compounds as inhibitors of adenosylmethionine decarboxylase: effects on the purified enzyme

The effects of chlorpromazine, imipramine, thioridazine, chlorprothixene, amitriptyline, desipramine and triflupromazine on adenosylmethionine decarboxylase purified from rat liver have been studied. The compounds caused competitive inhibition of the enzyme at 10(-5) - 10(-3) M concentrations. For chlorprothixene and triflupromazine the inhibition was linear, while the other drugs showed increasing, nonlinear inhibition at higher concentrations. Apparent Ki's for the compounds were between 6.8 X 10(-5) M (for chlorprothixene) and 6.4 X 10(-4) M (for desipramine). Inhibition of 50% under optimal assay conditions was achieved between drug concentrations of 1.3 X 10(-4) M (thioridazine) and 1.3 X 10(-3) M (imipramine).     

Developmental changes in mouse brain polyamine metabolism

Mouse brain ornithine decarboxylase (ODC) activity is high at the time of birth, whereas S-adenosyl-l-methionine decarboxylase (SAM-DC) activity is low. ODC activity, and putrescine, spermidine and spermine concentrations decline rapidly during postnatal development to the low level characteristic of mature brains, while SAM-DC activity behaves in the opposite manner. The fluctuations in mouse brain polyamine metabolism are in accord with those found in the rat. The apparentK _m values of ODC and SAM-DC for their substrates decline parallel with the decrease of substrate and product concentrations during ontogeny suggesting substrate and/or product dependent regulation of polyamine synthesis in the developing brain.     

Diurnal levels of polyamines and activities of ornithine andS-adenosyl-l-methionine decarboxylases in mouse brain

The levels of putrescine and spermine in mouse brain were rather constant at different times of day, as were the activities of ornithine andS-adenosyl-l-methionine decarboxylases. Contrary to an earlier report, the level of spermidine was found to be relatively constant. A possibly significant feature in the present results was the steady decline during the light period and rise during darkness of cerebral spermidine and spermine levels, the differences between maximum and minimum being about 15% for both compounds.     

Ethical issues in the diagnostic genetic testing process

The diagnostic genetic testing process has certain unique ethical features and deserves special consideration. The purpose of this study was to determine through empirical research, using focussed interview, what ethical issues are involved in the diagnostic genetic testing process. This article describes views and perceptions of adult patients, parents of child patients and various personnel groups (n = 30). The ethical issues were analysed classified into three main categories: a) personnel characteristics, including personality, professional skills, morals and values; b) realization of ethical principles in the examination process, with subcategories of knowledge, autonomy, data protection and equity; and c) consequences of genetic testing, including patients' control over their own lives, manifestation of heterogeneity and outlook on the world. Problematic ethical issues in all three main categories were described in a more many‐sided way by parents and personnel than by adult patients. In the future, attention should be paid to the content areas highlighted by the study, in both clinical practice and further studies.     

Characterization of the ascomycetes Therrya fuckelii and T. pini fruiting on Scots pine branches in Nordic countries

The relative frequency of Therrya fuckelii and T. pini fruiting on dead branches of Scots pine was investigated in southern Norway by examining lightning-damaged and wind-fallen trees, randomly collected branches and Nordic herbarium collections of these ascomycetes representing the order Rhytismatales. Ascus, ascospore, and subhymenium characteristics were used as criteria for species identification, while a sequence analysis of ITS rDNA gene cluster was performed to compare the relatedness of the species to each other and to corresponding fungal sequences available at the NCBI GenBank Sequence Database. In a few cases, the two Therrya species co-occurred on the same branch, but in general, whether field or herbarium material, T. fuckelii was clearly more common than T. pini. Within the Nordic countries, both species occurred throughout the natural distribution area of Scots pine. The ITS rDNA sequence of T. pini strains was 91% similar to T. fuckelii strains, the differences locating both within the internal transcribed spacers ITS1 and ITS2 and the 5.8 S rDNA gene. More variation in the ITS1-5.8S-ITS2 sequence was observed among T. pini than T. fuckelii samples; genetic implications of this finding are discussed. Upon sequence analysis, we discovered that a T. pini sequence has been deposited in the NCBI GenBank under a false identity. We emphasize the importance of co-examining strains that originate from mature fruit bodies with fully developed morphologic features as reference samples.