Salmon gill poxvirus disease in Atlantic salmon fry as recognized by improved immunohistochemistry also demonstrates infected cells in non-respiratory epithelial cells.

Gill diseases cause serious losses in farming of Atlantic salmon and the number of agents involved increases. Salmon gill poxvirus (SGPV) and the gill disease in causes where SGPV apparently was the only disease-causing agent were initially characterized. Recently, it was further shown that SGPV can be a common denominator in widely different multifactorial gill diseases. Here, we present the challenge of diagnosing gill disease with SGPV in salmon fry of 0,3-5 grams. Apoptosis of gill lamellar epithelial cells and hemophagocytosis was also observed in fry similar to findings in smolts and grow-out fish. Using our newly developed immunohistochemistry method, we further demonstrate that some of the apoptotic epithelial cells covering the oral cavity were positive for SGPV. Thus, SGPV is not restricted to respiratory epithelium alone and may infect the fish at very early life stages. Furthermore, as the cases examined here are from Norway, Faroe Island and Scotland, we show that SGPV is more widespread than previously reported.

Impact of profile haemodialysis on intra-/extracellular fluid shifts and the release of vasoactive hormones in elderly patients on regular dialysis treatment.

In 15 patients with end-stage renal failure and proven coronary heart disease, profile haemodialysis with decreasing ultrafiltration rate and hyperionic, decreasing dialysate solute concentration was compared with conventional, extracorporeal bicarbonate haemodialysis (Na+D = 138 mmol/l). Body fluid distribution and the release of vasoactive hormones (plasma renin activity, aldosterone, norepinephrine, epinephrine, and atrial natriuretic peptide) were investigated. Haemodialysis with constant ultrafiltration rate and constant dialysate composition (A) was followed by two dialysis profiles: decreasing ultrafiltration rate (B) and additional hyperionic, decreasing dialysate sodium concentration (C). In all 15 patients, the dialysis procedures (A) - (C) were used for 2 weeks each with six sessions, the last being taken for investigation. Body fluid distribution was calculated. In patients with serum sodium above 136 mmol/l, the conventional dialysis (A) as well as the Uf profile (B) showed a net fluid shift from extracellular volume (ECV) to intracellular volume (ICV). Using the profile with hyperionic, decreasing Na+D (C), the reverse fluid shift with decreasing ICV was achieved not only in those with serum Na+ <136 mmol/l, but also in those with serum Na+ > or = 136 mmol/l. The release of vasoactive hormones decreased already at profile haemodialysis (B) compared with (A) and was further reduced in (C). These results would suggest, profile dialyses B and C to have less impact on the cardiovascular system in elderly patients assuming higher patient comfort compared with the standard dialysis procedure. A higher benefit was obtained in C compared with B, presumably due to the additional prevention of the ICV shift and plasma volume depletion in patients with initial serum sodium > or = 136 mmol/l using transiently hyperionic Na+D. These results show that in elderly patients, hyperionic profile haemodialysis (Na+D > Na+S) had less impact on cardiovascular regulation than conventional bicarbonate dialysis.

Fluid-shift during computer-modulated profile hemodialysis (CMP-HD).

Computer-modulated profile hemodialysis was examined for patients' comfort and fluid-shift. Fifteen patients were studied after two weeks of dialysis with each of the following profiles: A): constant ultrafiltration (UF) and dialysate sodium (138 mmol/l); B): decreasing UF; C): decreasing UF and decreasing high dialysate sodium (starting 10% above serum-sodium, with a gradual reduction to 138 mmol/l in the fourth hour). Patients with a calculated increase of intracellular volume (ICV) during dialysis had more complaints after dialysis than the others. ICV decreased in all patients with low serum-sodium (less than 136 mmol/l) during all profiles, whereas in patients with higher sodium, only profile C led to a decrease of ICV. However, interdialytic weight gain increased about 75% in patients with low serum-sodium under profile C. The sodium profile could help in preventing imbalance without side effects in patients with high sodium.

Influence of computer-modulated profile haemodialysis on cardiac arrhythmias.

To reduce hamodialysis-induced ventricular arrhythmias, each of 15 patients (age 66.9 +/- 6.2 years) with end-stage renal disease and cardiac irregularities was treated subsequently with four different computer-modulated bicarbonate haemodialysis profiles (A-D) for 2 weeks respectively: (A) constant UF, dialysate Na (138 mmol/l) and K (2 mmol/l); (B) decreasing UF, otherwise as (A); (C) decreasing UF and Na (starting with 10% higher than serum Na), otherwise as (A); (D) decreasing UF and Na, adapted K to achieve a maximal reduction of serum K of only 15%/h. Cardiac monitoring was done by 11 h ECG. Only in haemodialysis profile D a distinct reduction of ventricular extrasystoles during and after haemodialysis was obtained. It was accompanied by an improvement in the Lown classification. In addition, a weak but highly predictive correlation between the number of ventricular extrasystoles in the last hour of dialysis and the difference between pre- and post-dialysis potassium concentration in the serum could be established (r = 0.37; P less than 0.004). Computer-modulated potassium profile haemodialysis is a useful tool to reduce the number and severity of ventricular extrasystoles.