One year's treatment with propranolol after myocardial infarction: preliminary report of Norwegian multicentre trial.

A prospective, randomised, double-blind study was performed to compare the effects of propranolol and placebo on sudden cardiac death in a high-risk group of patients who survived acute myocardial infarction. Altogether 4929 patients with definite acute myocardial infarction were screened for inclusion: 574 (11.6%) died before randomisation, and 3795 (77%) were excluded. Five hundred and sixty patients aged 35 to 70 years were stratified into two risk groups and randomly assigned treatment with propranolol 40 mg four times a day or placebo. Treatment started four to six days after the infarction. By one year there had been 11 sudden deaths in the propranolol group and 23 in the placebo group (p less than 0.038, two-tailed test analysed according to the "intention-to-treat" principle). Altogether there were 25 deaths in the propranolol group and 37 in the placebo group (P less than 0.12), with 16 and 21 non-fatal reinfarctions respectively. A quarter of the patients were withdrawn from each group. Withdrawal because of heart failure during the first two weeks of treatment was significantly more common among propranolol-treated patients than among the controls, but thereafter the withdrawal rate was the same. The significant reduction in sudden death was comparable with that after alprenolol, practolol, and timolol, which suggests that the mechanism of prevention is beta-blockade rather than any other pharmacological property of the individual drugs.     

No effect of variation in handling on behaviour in a porcine elevated plus-maze - a brief report

The elevated plus-maze is a widely used model of anxiety in rodents and has recently been suggested as a putative model of anxiety or fear in swine. The aim of the present experiment was to examine the effects of a pretest blood sampling procedure on the behaviour of weaned pigs in an elevated plus-maze. Animals in the control group were lifted one-by-one into a transport trolley and moved to the test apparatus, where they were observed for a 5-min period. The treatment group differed from the control group in that these animals were immobilized with a nose snare and a blood sample was extracted from the jugular vein prior to transport to the test room. Behaviour in the porcine elevated plus-maze did not differ significantly between the two handling procedures.     

Behavioural differences between three breed groups of hunting dogs confronted with domestic sheep

When running free in open fields, domestic dogs occasionally display predatory behaviour towards domestic sheep. This has not yet been studied scientifically. The aim of the present study was to investigate the inclination to chase sheep in three breed groups of hunting dogs that are most frequently used in areas with grazing sheep. We studied 41 elkhounds, 29 hare hunting dogs and 68 English setters. Behaviours indicative of motivation for chasing or attacking sheep were examined in three different ways. A path test examined functional traits such as hunting ability, contact willingness, reactivity to sudden noise, and response towards a lone sheep. In a sheep confrontation test, loose-leashed dogs were observed in a fenced enclosure with sheep and given electric shocks through an electronic dog collar if within 1-2m from the sheep. A questionnaire to the dog owners supplied information on their dog's previous experience with sheep and behavioural responses to various types of novel stimuli. No significant sex differences were found. The elkhounds showed the highest interest in a lone sheep in the path test, and displayed the highest initial hunting motivation, the highest percentage of dogs starting a sheep attack, the highest attack severity, and were most frequently given el. shocks. The hare hunting dogs were intermediate, while setters showed the lowest values for these variables. Dogs reported as showing low fearfulness more frequently acted as potential sheep chasers in the tests. Dogs up to 3 years of age showed a more pronounced initial hunting motivation and more frequent attacks than older dogs, although there were no age differences in the number of el. shocks given in the test. The latter may be related to the more frequent abruption of attacks among younger dogs. The main factors predicting a high hunting motivation and attack severity were lack of previous opportunity to chase sheep, low fearfulness towards gunshots and unfamiliar people, and general interest in sheep shown when encountering them. Probability of sheep chasing differed between dog breeds and age groups. Previous experience and certain character traits were indicative of a high predatory motivation towards sheep.     

A cautionary note regarding the use of nutritional L-tryptophan to alter aversion-related behaviour in mice

Nutritional L-tryptophan is reported to have positive effects on the behaviour of several farm animals. The present experiment describes some effects of nutritional L-tryptophan on the aversion-related behaviour of male mice selected for high litter size. The behavioural effects of L-tryptophan were observed in the elevated plus-maze, the light/dark test and a resident-intruder test. The only significant effect was observed in the resident-intruder test, where the total occurrence of exploratory behaviour by the intruder was reduced by L-tryptophan treatment. The present experiment provides a cautionary note advising against supplementation with L-tryptophan to improve animal welfare before the consequences of such treatment are fully understood.     

Influence of prenatal stress on steroidogenesis in gonads of blue foxes

Handling is a source of stress for farm bred blue foxes. The influence of handling during the late gestational period was investigated in 10-day-old male and female blue foxes. Testosterone and estradiol were measured by RIA in the plasma, gonadal homogenates andin vitro incubates, from blue foxes of both sexes. The gonads were incubatedin vitro without or with human chorionic gonadotropin. In cubs of both sexes, the gonad weights and ovarian estradiol production were decreased by stress. The testicular testosterone and ovarian estradiol contents were increased in prenatally stressed cubs as compared to the controls. The testicular content and baselinein vitro production of testosterone were not affected by prenatal stress, but the testicular response to human chorionic gonadotropin was higher in the stressed group. This study suggests that prenatal stress induced by handling pregnant vixens may influence gonadal steroidogenesis and that this effect was more pronounced in female cubs.     

Synthesis, structure, and antimycobacterial activity of 6-[1(3H)-isobenzofuranylidenemethyl]purines and analogs

6-Benzofuryl-, styryl, benzyl, and furfurylpurines as well as 6-[1(3H)-isobenzofuranylidenemethyl]purines have been synthesized and their activities against Mycobacterium tuberculosis (Mtb) determined. Several compounds displayed profound antimycobacterial activity in combination with low toxicity towards mammalian cells. NMR and X-ray crystallography were employed to determine the detailed structures and the results were supported by quantum chemical calculations.     

Protective neutralizing antibodies from human survivors of Crimean-Congo hemorrhagic fever

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The rise of a marine generalist predator and the fall of beta diversity

Determining the importance of physical and biological drivers in shaping biodiversity in diverse ecosystems remains a global challenge. Advancements have been made towards this end in large marine ecosystems with several studies suggesting environmental forcing as the primary driver. However, both empirical and theoretical studies point to additional drivers of changes in diversity involving trophic interactions and, in particular, predation. Moreover, a more integrated but less common approach to the assessment of biodiversity changes involves analyses of spatial β diversity, whereas most studies to date assess only changes in species richness (α diversity). Recent research has established that when cod, a dominant generalist predator, was overfished and collapsed in a northwest Atlantic food web, spatial β diversity increased; that is, the spatial structure of the fish assemblage became increasingly heterogeneous. If cod were to recover, would this situation be reversible, given the inherent complexity and non‐linear dynamics that typify such systems? A dramatic increase of cod in an ecologically similar large marine ecosystem may provide an answer. Here we show that spatial β diversity of fish assemblages in the Barents Sea decreased with increasing cod abundance, while decadal scale changes in temperature did not play a significant role. These findings indicate a reversibility of the fish assemblage structure in response to changing levels of an apex predator and highlight the frequently overlooked importance of trophic interactions in determining large‐scale biodiversity patterns. As increased cod abundance was largely driven by changes in fisheries management, our study also shows that management policies and practices, particularly those involving apex predators, can have a strong effect in shaping spatial diversity patterns, and one should not restrict the focus to effects of climate change alone.     

Phenotypic and genotypic heterogeneity among closely related soil-borne N2 - and N2 O-producing Bacillus isolates harboring the nosZ gene

Little is known about the genetic and phenotypic diversity of Gram-positive denitrifying bacteria. We compared the production of gaseous denitrification products for 14 closely related Bacillus soil isolates at pH 6 and 7 during 48-h batch incubations using a robotic gas-sampling apparatus. Primers targeting the nosZ gene encoding the nitrous oxide reductase were designed to confirm the presence of this gene in the isolates. The variation in the production of gaseous nitrogen products was compared with the genetic variation based on 16S rRNA gene sequences, genomic fingerprinting and nosZ sequences. The nosZ gene was detected in all isolates and all produced N(2) as the dominant end product at pH 7. Production of gaseous nitrogen products was more variable at pH 6, with different levels of NO and N(2) O production among the isolates, although minimal variation was observed among the 16S rRNA and nosZ gene sequences. One isolate was more divergent from the others based on genomic fingerprinting, and had two different nosZ gene copies, which coincided with the highest production of N(2) at pH 7 and the lack of intermediates at pH 6. Overall, our analysis suggests that genetic variation plays a role in the variation in N(2) O and N(2) production, but the variation in activity caused by acidification can be substantially greater than genotypic variation among closely related Bacillus.