Effects of a lecithin and catalase containing semen extender and a second dilution with different enhancing buffers on the quality of cold-stored canine spermatozoa.

In the present study, a diluent containing 0.8% lecithin (Minitube®, Tiefenbach, G) for the cold storage of canine semen was compared to a Tris-egg yolk extender (TRIS-EY) containing 20% egg yolk. For this purpose, aliquots of 10 mixed ejaculates (main fractions) were either diluted with TRIS-EY or with three lecithin extenders containing 0.8% lecithin with or without catalase and tyrosine. All samples were examined by computer assisted sperm analysis (CASA), chlortetracycline assay (CTC) and flow cytometry, sperm chromatin structure assay (SCSA) and zona pellucida binding assay (ZBA). Samples were then cold stored for 8 d and examinations repeated at days 3 and 8. Measurement in the CASA were repeated daily and prior to measurement, each sample was diluted with each of 4 enhancers with or without acetylcarnitine. The use of an enhancer proved to be essential for all extenders and after 8 d of cooling, progressive motility (P) and viability (V) still averaged > 70% and > 80% with the lecithin extenders containing additives, whereas with TRIS-EY and without additives it was significantly lower (P < 0.05). The percentage of capacitated spermatozoa did not differ between extender groups and there was no significant increase in acrosome reactions (AR) within 3 d. The chromatin status of cells was not changed by cooling within 8 d. The ZBA showed that with additives, significantly more spermatozoa bound to oocytes when a lecithin extender with additives was used (P < 0.05). In conclusion, the 0.8% lecithin extender containing catalase, conserved P and V during 8 d of cold storage better than the TRIS-EY extender, however, only when an enhancer was used; addition of acetylcarnitine to the enhancer did not further improve semen quality. The here introduced lecithin extender / enhancer combination is a useful tool for prolonged storage of cooled semen with excellent longevity and binding ability; addition of tyrosine to the extender did not improve semen quality.

Quantitative EEG in young diabetics.

The aim of this study was to investigate the influence of metabolic control on quantitative electroencephalographic (EEG) abnormalities in young diabetic patients. We compared quantitative EEGs of 44 insulin-dependent diabetic patients with age-matched controls. Furthermore, differences in EEG variables of diabetic patients and controls were correlated with the age of onset and duration of diabetes, hemoglobin A1c concentrations, and episodes with severe hypoglycemia. We found a correlation between high values of hemoglobin A1c and decreased relative power of the alpha band. Patients with previous ketoacidotic episodes had increased relative power of the delta/theta band and decreased relative power of the alpha band. Patients with hemoglobin A1c values less than 8.5% exhibited slowing of background activity compared with normal controls. We conclude that metabolic control influences the EEG and that improvement of glucose metabolism is an important factor in avoiding EEG abnormalities in young diabetic patients.