Is there a relationship between the overhead press and split jerk maximum performance? Influence of sex

The aims of this study were to (I) determine the differences and relationship between the overhead press and split jerk performance in athletes involved in weightlifting training, and (II) explore the magnitude of these differences in one-repetition maximum (1RM) performances between sexes. Sixty-one men (age: 30.4 ± 6.7 years; height: 1.8 ± 0.5 m; body mass 82.5 ± 8.5 kg; weightlifting training experience: 3.7 ± 3.5 yrs) and 21 women (age: 29.5 ± 5.2 yrs; height: 1.7 ± 0.5 m; body mass: 62.6 ± 5.7 kg; weightlifting training experience: 3.0 ± 1.5 yrs) participated. The 1RM performance of the overhead press and split jerk were assessed for all participants, with the overhead press assessed on two occasions to determine between-session reliability. The intraclass correlation coefficients (ICC) and 95% confidence intervals showed a high reliability for the overhead press ICC = 0.98 (0.97 – 0.99). A very strong correlation and significant differences were found between the overhead press and split jerk 1RM performances for all participants (r = 0.90 [0.93 – 0.85], 60.2 ± 18.3 kg, 95.7 ± 29.3 kg, p ≤ 0.001). Men demonstrated stronger correlations between the overhead press and split jerk 1RM performances (r = 0.83 [0.73-0.90], p ≤ 0.001) compared with women (r = 0.56 [0.17-0.80], p = 0.008). These results provide evidence that 1RM performance of the overhead press and split jerk performance are highly related, highlighting the importance of upper-limb strength in the split jerk maximum performance

Progress towards cloning the cystic fibrosis gene.

Genetic linkage analysis with polymorphic DNA markers (restriction fragment length polymorphisms: RFLPS) has allowed the assignment of the cystic fibrosis (CF) locus to the long arm of chromosome 7, within the region of band q31. Two of these markers, MET and D7S8, are tightly linked to the disease locus. Although recent data suggest that they are located on opposite sides of CF, the two can be separated by as much as 5 centimorgans. To obtain a better description of the CF locus and, eventually, to identify the affected gene, additional DNA markers are required to connect MET and D7S8, physically. We have screened the flow-sorted chromosome-7-specific library and thus far isolated 28 new probes from the 7q31 region by DNA hybridization analysis that uses a series of somatic cell hybrids containing various portions of human chromosome 7. Together with the previously identified markers, MET, D7S8, D7S13 and D7S16, these new markers should provide a fine genetic and physical map for the chromosomal region surrounding CF. DNA segments can then be sequentially cloned by chromosome walking from points closest to the CF locus and examined for genes that are preferentially expressed in tissues known to be affected in the disease.link_to_subscribed_fulltex

The role of the immune system beyond the fight against infection

The immune system was identified as a protective factor during infectious diseases over a century ago. Current definitions and textbook information are still largely influenced by these early observations, and the immune system is commonly presented as a defence machinery. However, host defence is only one manifestation of the immune system’s overall function in the maintenance of tissue homeostasis and system integrity. In fact, the immune system is integral part of fundamental physiological processes such as development, reproduction and wound healing, and a close crosstalk between the immune system and other body systems such as metabolism, the central nervous system and the cardiovascular system is evident. Research and medical professionals in an expanding range of areas start to recognise the implications of the immune system in their respective fields. This chapter provides a brief historical perspective on how our understanding of the immune system has evolved from a defence system to an overarching surveillance machinery to maintain tissue integrity. Current perspectives on the non-defence functions of classical immune cells and factors will also be discusse