1. Center of Gynecology and Obstetrics, Faculty of Medicine, Justus Liebig University Giessen, 35392 Giessen, Germany
2. Department of Biochemistry, University of Nairobi, Nairobi P.O. Box 30197-00100, Kenya
3. Department of Health Sciences, Kirinyaga University, Kerugoya P.O. Box 143-10300, Kenya
4. Institute for Veterinary Physiology and Biochemistry, School of Veterinary Medicine, Justus Liebig University Giessen, 35392 Giessen, Germany