[Trend of the selenium supply of cattle in Germany, Austria, Switzerland, and Denmark. Retrospective analysis of serum samples of the years 2006-2015]. / Trend der Selenversorgung beim Rind in den Ländern Österreich, Schweiz, Deutschland und Dänemark. Retrospektive Analyse von Serumproben aus den Jahren 2006-2015.

OBJECTIVE: An optimal selenium supply of cattle is essential, because an insufficiency can lead to health disorders and reduced performance. The aim of the study was to retrospectively evaluate the selenium supply of cattle in Germany, Austria, Switzerland, and Denmark. MATERIAL AND METHODS: Serum samples from 45  068 cattle with unknown clinical status originating from countries all across Europe, which had been sent by veterinarians to the IDEXX Laboratory Ludwigsburg, Germany, between January 1st, 2006 and June 30th, 2015, were routinely analyzed for the selenium concentration by means of Inductively Coupled Plasma Mass Spectrometry. A total of 40  949 samples (30  462 from Germany, 4004 from Austria, 3232 from Switzerland, 3251 from Denmark) were included in the evaluation. Results were categorized as follows: 50-150 µg/l: sufficient supply, < 50 µg/l: supply too low, > 150 µg/l: supply too high. RESULTS: During the observation period, a generalized trend towards a decreasing selenium supply was clear. Denmark showed the best selenium supply (77.4% of samples indicating a sufficient supply); however, even in this country a tendency towards a deterioration was seen. A very poor situation with a strongly decreasing selenium supply was observed in Austria, followed by Germany (38% and 30% of samples, respectively, indicating an undersupply). For Switzerland, a constantly poor selenium supply was found (49% of samples indicating an undersupply). CONCLUSION AND CLINICAL RELEVANCE: Due to the ongoing trend of a selenium undersupply in cattle herds, it is recommended to control the serum selenium concentration annually and supplement this trace element via mineral food when necessary.

[Differences in the selenium supply of cattle across Europe]. / Saisonale und überregionale Unterschiede im Selenversorgungsstatus von Rindern.

OBJECTIVE: Evaluation of differences in the selenium supply of cattle across Europe. MATERIAL AND METHODS: A total of 35,722 serum samples from cattle throughout Europe (unknown clinical status), which had been sent by veterinarians to the IDEXX Vet Med Lab Ludwigsburg, Germany between January 1st, 2006, and June 30th, 2013, were analyzed routinely for the selenium concentration using ICP-analysis. RESULTS: The collective data of the selenium concentration in cattle serum display seasonal variations, with a lower concentration during summer when compared to the winter. In recent years, the selenium supply has decreased. The farm size, husbandry conditions, economic situation, soil selenium concentration and the countries' specific feeding together play a key role in the selenium supply of the herd. Hungary and the Scandinavian countries Sweden and Denmark show the best selenium supply in Europe. A very poor situation exists in France and Luxembourg (> 50% of the cattle samples are undersupplied). CONCLUSION AND CLINICAL RELEVANCE: An optimal selenium supply for cattle is very important; a trace element deficiency can cause negative health effects and impair herd performance. The selenium concentration varies considerably, depending upon feeding and husbandry conditions. Therefore, a serum selenium analysis in cattle is essential and should be performed annually.

Apoptosis is initiated by myocardial ischemia and executed during reperfusion.

Ischemia/reperfusion leading to myocyte cell death has been reported as either necrotic or apoptotic or a combination of both. The importance of necrosis is well established but the role of apoptosis and the time of initiation are still unknown. Normothermic global ischemia of either 45 or 90 min duration followed by 6 h of reperfusion were induced in isolated canine hearts. After 45 min of ischemia, left ventricular function and adenine nucleotide (AN) content had recovered during reperfusion indicating reversible injury. DNA fragmentation determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) was absent as was the 85 kDa fragment of poly-(ADP-ribose) polymerase (PARP). After 90 min of ischemia, electron microscopy indicated necrotic cell death in 90% of myocytes. Recovery of function and AN content during reperfusion was minimal. At the end of ischemia, caspase-3 was activated in 30% of all myocytes and PARP 85 kDa fragments were present by Western blot, indicating initiation of the apoptotic cascade. Lamin-B(1)labeling was significantly reduced from 90% in myocytes in control and ischemia to 30% in early reperfusion. Completion of apoptosis seen by TUNEL was evident in late reperfusion (7.6% of myocytes and 8.3% of non-myocytes). Experiments with 6 h ischemia without reperfusion showed absence of DNA fragmentation. We conclude that apoptotic cell death is initiated by ischemia but that reperfusion is needed for completion of the apoptotic cascade. Furthermore, it is concluded that cell death in acute global ischemia followed by reperfusion occurs predominantly by necrosis and that apoptosis is of minor importance in this pathophysiological situation.

Cardiomyocyte apoptosis in acute and chronic conditions.

Myocytes can die by necrosis or by apoptosis and the characteristics of both kinds of cell death are so typical that a differentiation can be made by histological and molecular-biological methods using electron microscopy, dUTP labeling with fluorescence or peroxidase staining (TUNEL) and the DNA laddering method. However, the problem of quantification of apoptotic cells has not been completely solved because of lack of standardization as well as uncritical use and interpretation of the TUNEL method. Equally, quantification of apoptotic cells is not optimal until now because of three reasons: methodological (overinterpretation of results, no differentiation between myocytes and non-myocytes), experimental (global or regional acute ischemia, chronic conditions such as heart failure or hibernating myocardium), and interpretation (unknown time period for the completion of apoptosis). This problem is reflected in the large differences in incidence of apoptosis reported. Our own data show that in dog myocardium made globally ischemic for 90 min, 8% of the myocytes showed a positive staining for apoptosis (TUNEL method) after 6 h of reperfusion. Despite these results the question of reperfusion injury and the influence of apoptosis still remains open, because it can not be excluded until now that the apoptotic process is initiated during the ischemic period. Studies in hibernating myocardium and chronic heart failure show a similar situation, because of a wide variation of numbers of apoptotic cells and the limited possibility to investigate human tissue. There is no doubt that apoptosis plays an important role in chronic pathophysiological situations such as heart failure and hibernating myocardium but the importance of apoptosis in the acute situation of ischemia/reperfusion still has to be clarified.