Synergistic effects of dietary iron and omega-3 fatty acid levels on survival of farmed Atlantic salmon, Salmo salar L., during natural outbreaks of furunculosis and cold water vibriosis.

The present study demonstrates that farmed Atlantic salmon, Salmo salar, health is positively and significantly affected by synergistic effects between very long-chain polyunsaturated fatty acids of the n-3 family eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) and iron, where positive effects of high dietary levels of EPA/DHA are enhanced when combined with low levels of iron. Based on cumulative mortalities in the different experimental groups, relative percentage of survival (RPS) for the high EPA/DHA-low iron group was 70% during an outbreak of furunculosis and 96% during an outbreak of cold water vibriosis compared with the controls. A non-additive effect between EPA/DHA and iron was confirmed by statistical analyses that revealed a significant effect of EPA/DHA alone and an interaction of iron with EPA/DHA. Liver cell cultures treated with EPA/DHA revealed that the synergistic effect could be related to an EPA/DHA dependent regulation of mRNA for proteins important for transport (transferrin) and storage (ferritin) of iron in the salmon. In keeping with this finding, the transcriptional down-regulation of iron metabolism in vitro was reflected in decreased in vivo iron stores with increasing levels of dietary EPA/DHA. Hence, to avoid overloading of the iron transport/storage-systems resulting in increased susceptibility to bacterial infections, high levels of dietary EPA/DHA should be accompanied by low levels of dietary iron.

Effect of K-diformate in starter diets on acidity, microbiota, and the amount of organic acids in the digestive tract of piglets, and on gastric alterations.

The aim of this investigation was to study the effect of K-diformate on the intraluminal pH, microbial composition in digesta and feces, organic acids along the digestive tract, and alterations of the gastric epithelium of pigs. Pigs (n = 36) weaned at 28 d of age were allotted to two groups and fed without (control diet) or with 1.8% supplemental K-diformate. Fecal samples were taken from the rectum on d 0, 1, 3, 5, 7, 14, 21, and 28 postweaning. Half of the animals from each group were killed on d 7 and the other half on d 29 postweaning. Growth performance was not different for both groups (P > or = 0.73). The gastric epithelium was not negatively affected by K-diformate (P = 0.25). Potassium-diformate decreased (P < or = 0.04) or tended to decrease (P < or = 0.10) the counts of total anaerobic bacteria, lactic acid bacteria, and yeasts in feces and digesta samples from the stomach, distal small intestine, cecum, and middle segment of the colon. The pH along the gastrointestinal tract of piglets was not affected by K-diformate (P > or = 0.30). On d 7, the concentration of lactic acid along the gastrointestinal tract was similar with both diets (P = 0.15). On d 29, the concentrations of lactic acid tended to be lower along the small intestine (P < or = 0.08) and the stomach (P = 0.11) of the pigs fed K-diformate. Formic acid in digesta was detected at significant levels only in the distal segment of the small intestine of the control pigs (from 4 to 11 mmol/kg of wet digesta), whereas considerable amounts were measured in the stomach (from 23 to 40 mmol/kg of wet digesta) and all segments of the small intestine (from 7 to 25 mmol/kg of wet digesta) in the K-diformate-fed pigs on both days. On d 7, pigs fed the K-diformate diet had a tendency (P < or = 0.08) to have higher concentrations of organic acids (acetic + propionic + butyric) in the digesta of the distal small intestine, cecum, and proximal colon. On d 29, both groups had similar concentrations of these acids, irrespective of the segment of the gastrointestinal tract (P = 0.95). Our study showed that the addition of K-diformate to a starter diet for piglets decreased total anaerobic bacteria, lactic acid bacteria, coliforms, and yeasts in feces and in digesta from various segments of the gastrointestinal tract, without affecting the gastric or intestinal pH.

Effect of dietary formates on growth performance, carcass traits, sensory quality, intestinal microflora, and stomach alterations in growing-finishing pigs.

Three experiments were conducted to evaluate the effect of adding salts of formic acid to diets for growing-finishing pigs. In Exp. 1, 72 pigs (23.1 kg and 104.5 kg initial and final BW) were used to evaluate the effect of Ca/Na-formate and K-diformate on performance and carcass traits. Treatments were organized in a 2 x 3 factorial arrangement with two feeding regimens (limit and semi-ad libitum feeding) and three diets (control, .85% Ca/Na-formate, and .8% K-diformate). No significant feeding regime x diet interaction was found. The K-diformate diet increased overall ADG of pigs compared with the control and Ca/Na-formate diets, but had no effect on ADFI or gain/feed (G/F) ratio. Neither K-diformate nor Ca/Na-formate had any effect on carcass lean or fat content. In Exp. 2, 10 limit-fed pigs (24.3 kg and 85.1 kg initial and final BW) were used to study the effect of K-diformate on performance and sensory quality of pork. Adding .8% K-diformate to diets increased ADG (P < .13) and G/F (P < .04), but had no effect on sensory quality of the pork or content of formate in liver, kidney, or muscle tissue of pigs. In Exp. 3, 96 limit-fed pigs (27.1 kg and 105 kg initial and final BW) were used to determine the effect of adding K-diformate to diets on performance, carcass traits, and stomach keratinization and(or) lesions. Adding K-diformate (0, .6, or 1.2%) to diets increased ADG and ADFI (linear P < .01). The K-diformate reduced the percentage of carcass fat (linear P < .03) and fat area in the cutlet (linear P < .09) and increased percentage lean in the ham (linear P < .01), flank (linear P < .02), loin (linear P < .09), and neck and shoulder (linear P < .09). The K-diformate had no negative effect on stomach alterations. In Exp. 3, the concentration of coliform bacteria in the gastrointestinal tract was evaluated in eight control and eight 1.2% K-diformate-fed pigs. The K-diformate reduced the number of coliforms in the duodenum (P < .03), jejunum (P < .02), and rectum (P < .10) of pigs. In conclusion, K-diformate improved growth performance and carcass quality of growing-finishing pigs, whereas Ca/Na-formate had no effect. K-diformate had no adverse effect on sensory quality of pork or on stomach alteration scores.

Thallium-201 as an agent for myocardial imaging studies.

The increasing use of thallium-201 (201Tl) in myocardial imaging studies during the last two decades, has justified a re-examination of the metabolism of this metal compound. It was found that about 4% of an injected dose was rapidly distributed to the healthy human myocardium, which is in agreement with previous reports. Apparent similarities exist between the transport of ionic thallium and potassium through cell membranes. Upon clinical use, myocardial perfusion scintigraphy is routinely carried out after i.v. administration of the agent. It is generally accepted that the rapid myocardial extraction of circulating 201Tl, during the initial 30 min. depends upon an unimpaired blood perfusion; whereas the prolonged uptake/redistribution during the next 3 h reflects myocardial viability. In the present paper, the reliability of 201Tl scintigraphy to disclose insufficient myocardial perfusion is illustrated by the examination of biological samples from patients, that were also studied by the classical coronary angiographic technique, the two methods showed an acceptable degree of agreement.

[Thallium scintigraphy in the diagnosis of coronary disease]. / Thalliumscintigrafi i diagnostisering av koronar hjertesykdom.

A retrospective analysis was performed in 371 patients who underwent stress thallium scintigraphy over a three-year period. The patient-group was highly selected. The majority had normal or uninterpretable exercise EKG. The purpose was to assess the clinical value of thallium scintigraphy, and to determine the accuracy of the test compared with coronary arteriography for diagnosis of coronary artery disease in 108 of the patients who had undergone cardiac catheterisation. For 79 patients (73%), the scintigraphic results were in complete accordance with the coronary arteriograms. Furthermore, critical review of the arteriograms showed discrete stenosis of less than 50% in another 12 of the patients with abnormal scans. This yields an overall diagnostic accuracy of 84%. The authors discuss some limitations of the method and possible causes of "false" perfusion defects. The results of the analysis are consistent with earlier reports, and emphasize thallium scintigraphy as a valuable diagnostic tool in coronary heart disease.