Seasonal increase in sea temperature triggers pancreas disease outbreaks in Norwegian salmon farms.

Pancreas disease (PD) is a viral disease causing negative impacts on economy of salmon farms and fish welfare. Its transmission route is horizontal, and water transport by ocean currents is an important factor for transmission. In this study, the effect of temperature changes on PD dynamics in the field has been analysed for the first time. To identify the potential time of exposure to the virus causing PD, a hydrodynamic current model was used. A cohort of salmon was assumed to be infected the month it was exposed to virus from other infective cohorts by estimated water contact. The number of months from exposure to outbreak defined the incubation period, which was used in this investigation to explore the relationship between temperature changes and PD dynamics. The time of outbreak was identified by peak in mortality based on monthly records from active sites. Survival analysis demonstrated that cohorts exposed to virus at decreasing sea temperature had a significantly longer incubation period than cohorts infected when the sea temperature was increasing. Hydrodynamic models can provide information on the risk of being exposed to pathogens from neighbouring farms. With the knowledge of temperature-dependent outbreak probability, the farmers can emphasize prophylactic management, avoid stressful operations until the sea temperature is decreasing and consider removal of cohorts at risk, if possible.

An integrated, temporal study of the behavioural, electrophysiological and neuropathological consequences of murine prion disease.

We have conducted an integrated study of ME7 prion disease by examining the electrophysiological and neuropathological features of hippocampal slices from behaviourally characterised C57Bl/6J mice 12, 14, 16, 18, 20 and 24 weeks after intracerebral micro-injection of ME7 or normal brain homogenate. We describe the pathogenesis of ME7 as a three-stage process. STAGE ONE: PrPSc deposition, synaptic pathology and abnormal synaptic plasticity. STAGE TWO: Onset of behavioural changes, exemplified by an increase in open-field activity, enhancement of the slow AHP and development of vacuolation. Membrane depolarisation is also an early feature, but its exact timing remains to be confirmed. STAGE THREE: Clinical disease, substantial neurodegeneration and further disruption of the action potential profile. We suggest that the mechanisms underlying the electrophysiological changes of Stages one and two may provide novel approaches to treatment of prion disease, and that those seen in Stage three may be relevant to neurodegenerative diseases more generally.

Stability of intralipid fat emulsion in amino acid solutions.

The stability of the fat emulsion Intralipid 20% depends to a great extent on the electric-repulsive forces between the fat particles. The negative charge of the fat particles (zeta-potential) in Intralipid 20% was measured in large bags containing three different commercially available amino acid solutions, two of which had electrolytes. In each case, the electronegativity was not great enough to give the solution adequate stability. When arginine and methionine were added to Intralipid, an increase in pH resulted in more of an electronegative zeta-potential. Varying the concentration of arginine did not affect the zeta-potential the same as changing the pH of the mixture. Thus, a high pH and, to a lesser extent, the quantities of amino acids appear to be important factors in increasing the electrostability of Intralipid.

Colonic haemorrhage in diverticular disease--diagnosis and treatment.

A retrospective review of acute diverticular disease in 230 patients revealed that 46 had presented with haemorrhage. The symptoms, investigations and outcome in these 46 cases are reported and the optimum management of profuse colonic haemorrhage is discussed.

New aspects in the treatment of water hemlock poisoning.

A man inadvertently ate a whole root of the highly poisonous water hemlock (Cicuta virosa L.) plant. The chief symptoms were convulsions, unconsciousness, reddish tinted cyanosis, dilated pupils and marked metabolic acidosis. The patient survived due to treatment with haemodialysis, haemoperfusion, forced diuresis and artificial ventilation. The cicutoxin molecule size was calculated and it was found to be dialysable.

New method for administration of hydrochloric acid in metabolic alkalosis.

In a new method for peripheral intravenous infusion of hydrochloric acid the HCl is buffered in an aminoacid solution and infused with a fat emulsion. The aminoacids and the fat emulsions are stable in the presence of HCl, and the transfusion set is resistant to the chemical actin of 0.15 mol/l HCl. Two case-reports show that HCl can be administered safely through a peripheral vein.