K+ channel mutations in adrenal aldosterone-producing adenomas and hereditary hypertension

Endocrine tumors such as aldosterone-producing adrenal adenomas (APAs), a cause of severe hypertension, feature constitutive hormone production and unrestrained cell proliferation; the mechanisms linking these events are unknown. We identify two recurrent somatic mutations in and near the selectivity filter of the potassium (K(+)) channel KCNJ5 that are present in 8 of 22 human APAs studied. Both produce increased sodium (Na(+)) conductance and cell depolarization, which in adrenal glomerulosa cells produces calcium (Ca(2+)) entry, the signal for aldosterone production and cell proliferation. Similarly, we identify an inherited KCNJ5 mutation that produces increased Na(+) conductance in a Mendelian form of severe aldosteronism and massive bilateral adrenal hyperplasia. These findings explain pathogenesis in a subset of patients with severe hypertension and implicate loss of K(+) channel selectivity in constitutive cell proliferation and hormone production.     

Building and destroying social capital: The case of cooperative movements in Denmark and Poland

Social capital, measured as the level of trustamong people, may be regarded as a newproduction factor alongside the traditionalones of human and physical capital. Withappropriate levels of social capital,monitoring and transaction costs can be savedand thus economic growth stimulated. Vialinking social capital to rural development andcomparing the cases of agricultural cooperativemovements in Denmark and Poland, this paperidentifies possible roots of building socialcapital and suggests that social capital wasbuilt through a lengthy process in bothcountries during the 19th century. However,the comparison of the present level of socialcapital indicates that the level of socialcapital is significantly higher in Denmark thanin Poland. The paper concludes that the reasonfor this difference is the fact that theoriginal accumulation of social capital inPoland was destroyed by the communist regime.     

Iron Poisoning in Piglets Autopsy Findings in Experimental and Spontaneous Cases

An account is given of the autopsy findings in 78 piglets which died from iron poisoning. They belonged to an experimental series which included a further 6 piglets that also died but will not be accounted for here. The experiment was designed to study why iron treatment causes occasional deaths among piglets. The results will be reported in full elsewhere (Tollerz, in press).In 63 piglets, the sows had been fed special experimental diets, and in 8 piglets from a field case where deaths occurred after conventional iron treatment to prevent anaemia, the predominant autopsy finding was waxy degeneration of the skeletal muscles, which appeared irrespective of whether iron dextran or iron dextrin was injected intramuscularly, or whether ferrofumarate or ferous sulphate was given orally. Only one piglet had slight heart-muscle degeneration, and hydropericardium was not present.The remaining 7 piglets received ferrous sulphate orally, which resulted in catarrhal to necrotizing gastroenteritis. Three of these piglets had waxy degeneration of the skeletal muscles, but in the other 4 the musculature was intact, which indicates another mechanism of toxicity than that in the cases of muscle degeneration.     

Varietal differences in accumulation of ochratoxin a in barley and wheat cultivars after inoculation of Penicillium verrucosum

The natural content of ochratoxin A in grain samples of 6 barley, 2 bread wheat and 1 durum wheat cultivars varied from <0.1 to 0.4 ng/g grain. Samples of the analysed cultivars were surface sterilized and kept in humidity chambers at 20°C and water activity (a_w) 0.75 or a_w 0.85 for 8 days. For both environments, the resulting grain equilibrium water content varied between cultivars of both barley and wheat, attributable to agronomic traits. The samples were then inoculated with Penicillium verrucosum and incubated for up to 23 weeks. With time, all cultivars had increasing ochratoxin A content, with maximum content in different barley cultivars ranging from 34 to 630 ng/g grain for a_w 0.75, and 39 to 260 000 ng/g for a_w 0.85. Corresponding values for the wheat cultivars were 25 to 2 300 ng/g and 650 to 5 200 ng/g. Significant varietal differences in ochratoxin A accumulation were observed for barley (P < 0.0001), attributable to equilibrium water content, amylose content and natural ochratoxin A, and for wheat (P < 0.0001), attributable to protein content and natural ochratoxin A. Barley ‘SW 1306 95/1203’ and ‘SW 906129 Waxy’, and wheat ‘SW 39103’ accumulated significantly less ochratoxin A than the other cultivars.     

Stores of exchangeable base cations and aluminium in Lysimeters previously treated with sulphuric acid or NPK with and without irrigation

Lysimeters consisting of intact soil cores, including field- and ground-layer vegetation, from a sandy podzol were treated with irrigation water, H₂SO₄ or NPK and combinations thereof. The acid and fertilizer applications corresponded to 100 kg H₂SO₄ per ha annually and a total of 360 kg N per ha, respectively. Precipitation and leachates from the lysimeters were analyzed for main chemical constituents during a 6-year-period. There-after the experiment was terminated and the cores were fractionated into appropriate vegetation and soil strata. Chemical analyses of the soil revealed a significant increase of exchangeable aluminium in the B- and B/C-horizons due to H₂SO₄ application, accompanied by a decrease of magnesium in the same horizons.The fertilizer caused a net depletion of magnesium in the B- and B/C-horizons mainly due to high levels of replacing cations other than magnesium and correspondingly high levels of mobile anions.Budget calc.ulations indicated increased weathering of magnesium and calciu acid treatment. There were also indications of a calcium adsorption from the irrigation water.H⁺ activity estimated from pH measuremetns in 0.001 M CaCl₂, had increased in the A₀-horizon, in lysimeters treated with sulphuric acid, probably an effect of aluminium hydrolysis. There was a slight in activity in the A₀-horizon of the fertilized lysimeters.     

Studies of Transferrin Polymorphism in Swedish Cattle Using Agarose Gel Electrophoresis

The polymorphic transferrin picture in the sera from 894 Swedish cattle was investigated with an agarose gel electrophoresis technique. The serum transferrin bands in the electrophoresis pattern were first identified by labelling with ⁵⁹Fe. Six existing phenotypes based on the alleles Tf^A, Tf^D and Tf^E could be detected. The frequencies of transferrin types and transferrin alleles are presented, and it is concluded that there are great differences in the frequencies between the Swedish Red and White and the Swedish Friesian.     

When counting cattle is not enough: multiple perspectives in agricultural and veterinary research

A traditional approach in agricultural and veterinary research is focussing on the biological perspective where large cattle-databases are used to analyse the dairy herd. This approach has yielded valuable insights. However, recent research indicates that this knowledge-base can be further increased by examining agricultural and veterinary challenges from other perspectives. In this paper we suggest three perspectives that may supplement the biological perspective in agricultural and veterinary research; the economic-, the managerial-, and the social perspective. We review recent studies applying or combining these perspectives and discuss how multiple perspectives may improve our understanding and ability to handle cattle-health challenges.     

Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds

Background

Bovine babesiosis is regarded as a limited health problem for Norwegian cows, and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with Babesia divergens and B.venatorum have been described. The objective of this study was to determine whether birds can introduce Babesia-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring.

Methods

Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003, 2004 and 2005. The presence of Babesia was detected in the nymphs of Ixodes ricinus by real-time PCR. Positive samples were confirmed using PCR, cloning and phylogenetic analyses.

Results

Of 512 ticks examined, real-time PCR revealed five to be positive (1.0%). Of these, four generated products that indicated the presence of Babesia spp.; each of these were confirmed to be from Babesia venatorum (EU1). Two of the four B. venatorum-positive ticks were caught from birds having an eastern migratory route (P< 0.001).

Conclusions

Birds transport millions of ticks across the North Sea, the Skagerrak and the Kattegat every year. Thus, even with the low prevalence of Babesia-infected ticks, a substantial number of infected ticks will be transported into Norway each year. Therefore, there is a continuous risk for introduction of new Babesia spp. into areas where I. ricinus can survive.     

Temporal changes in abundance and composition of ammonia-oxidizing bacterial and archaeal communities in a drained peat soil in relation to N<Subscript>2</Subscript>O emissions

Purpose  

Boreal peat soils comprise about 3% of the terrestrial environments, and when drained, they become sources of the greenhouse gas nitrous oxide (N₂O). Ammonia oxidation can result in N₂O emissions, either directly or by fuelling denitrification, but we know little about the ecology of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in peat soils. Our aim was to determine temporal alterations in abundance and composition of these communities in a drained and forested peat soil in relation to N₂O emissions and ammonia oxidation activity.