) Increase in plasma adenosine during brain ischemia in man: a study during transient ischemic attacks, and stroke. Brain Res Bull

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genotypes in [85 females have an immunological advantage over the ADA 2-1 males of the same age. The above premises, and the negligible, not statisti- cally significant reduction of the ADA 2-1 genotype in females in the 80–85 age group point to the marginal relevance of ADA activity in the pathways that influence longevity in this gender. More generally, these notions are in line with the published evidence that variability of genetic factors contributes to determining the phenotype much more in males than in females and that female longevity is less dependent than male longevity on hereditary factors (Bellizzi et al. 2005; De Luca et al. 2001; Ivanova et al. 1998; Passarino et al. 2006; Tan et al. 2001).

Thus, it is likely that males and females follow different routes to attain longevity and that female longevity has a lower genetic component with respect to males. The better life-style and more favourable environmental factors which have characterised western society over the last century may have then benefited women more than males and, consequently, further reduced the genetic component of female longevity (Guralnik et al. 2000; Montesanto et al.

stitution results in the adenosine deaminase (ADA) genetic polymorphism (ADA

allozyme): occurrence on different chromosomal backgrounds and apparent intra- genic crossover. Ann Hum Genet

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) ATS/ERS task force on exhaled breath condensate: exhaled breath condensate: methodological recommen- dations and unresolved questions. Eur Respir J

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Husza´r E, Horva´th I, Bara´t E, Herjavecz I, Bo¨szo¨rme´nyi-Nagy G, Kollai M (

) Elevated circulating adenosine level potentiates antigen-induced immediate bronchospasm and bronchoconstrictor mediator release in sensitized guinea pigs. J Allergy Clin Immunol

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Ivanova R, He´non N, Lepage V, Charron D, Vicaut E, Scha¨chter F (

) HLA-DR alleles display sex-dependent effects on survival and discriminate between individual and familial longevity. Hum Mol Genet

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Kameoka J, Tanaka T, Nojima Y, Schlossman SF, Morimoto C (

) Direct association of adenosine deaminase with T cell activation antigen, CD

Science

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Laghi Pasini F, Guideri F, Picano E, Parenti G, Petersen C, Varga A, Di Perri T (

) Increase in plasma adenosine during brain ischemia in man: a study during transient ischemic attacks, and stroke. Brain Res Bull

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In conclusion, the data presented here provide new evidence for a relevant biological role of adenosine deaminase, adding another piece to the complex puzzle of genetic and environmental factors involved in control of lifespan expectancy in humans.

Acknowledgments We thank Cynthia L. Pon and Claudio O. Gualerzi for checking the English.

Conflict of interest None declared.

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