Tuesday, February 26, 2008

The Chemist that dreamt of Ouroboros



August KekulĂ© (September 7, 1829 – July 13, 1896)

Sunday, February 17, 2008

Stop drinking coffee and go to bed early for better reproductive success?

The effects of male age on sperm DNA damage in healthy non-smokers

Author(s): Schmid TE (Schmid, T. E.), Eskenazi B (Eskenazi, B.), Baumgartner A (Baumgartner, A.), Marchetti F (Marchetti, F.), Young S (Young, S.), Weldon R (Weldon, R.), Anderson D (Anderson, D.), Wyrobek AJ (Wyrobek, A. J.)
Source: HUMAN REPRODUCTION Volume: 22 Issue: 1 Pages: 180-187 Published: 2007
Times Cited: 4 References: 64
Abstract: BACKGROUND: The trend for men to have children at older age raises concerns that advancing age may increase the production of genetically defective sperm, increasing the risks of transmitting germ-line mutations. METHODS: We investigated the associations between male age and sperm DNA damage and the influence of several lifestyle factors in a healthy non-clinical group of 80 non-smokers (mean age: 46.4 years, range: 22-80 years) with no known fertility problems using the sperm Comet analyses. RESULTS: The average percentage of DNA that migrated out of the sperm nucleus under alkaline electrophoresis increased with age (0.18% per year, P = 0.006), but there was no age association for damage measured under neutral conditions (P = 0.7). Men who consumed > 3 cups coffee per day had similar to 20% higher percentage tail DNA under neutral but not alkaline conditions compared with men who consumed no caffeine (P = 0.005). CONCLUSIONS: Our findings indicate that (i) older men have increased sperm DNA damage associated with alkali-labile sites or single-strand DNA breaks and (ii) independent of age, men with substantial daily caffeine consumption have increased sperm DNA damage associated with double-strand DNA breaks. DNA damage in sperm can be converted to chromosomal aberrations and gene mutations after fertilization, increasing the risks of developmental defects and genetic diseases among offspring.
Document Type: Article
Language: English
Author Keywords: ageing; caffeine; Comet; DNA damage; sperm
KeyWords Plus: CHROMATIN-STRUCTURE ASSAY; COMET ASSAY; PATERNAL-AGE; SEMEN QUALITY; CHROMOSOMAL-ABERRATIONS; SPONTANEOUS MUTATION; ANTIOXIDANT INTAKE; CIGARETTE-SMOKING; OXIDATIVE STRESS; MOUSE ZYGOTES
Addresses: Wyrobek, AJ (reprint author), Lawrence Berkeley Lab, Life Sci Div, Berkeley, CA USA
Univ Calif Berkeley, Sch Publ Hlth, Berkeley, CA USA
Univ Bradford, Dept Biomed Sci, Bradford, W Yorkshire England
Publisher: OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
Subject Category: Obstetrics & Gynecology; Reproductive Biology
IDS Number: 120EA
ISSN: 0268-1161
DOI: 10.1093/humrep/del338