Heredity of low back pain in a young population: a classical twin study.

Important genetic influence on intervertebral disc degeneration has been shown previously. However, the role of the disc in pain production is not clear and the genetic influence on the development of the symptoms of low back pain is largely unknown. Therefore, data on lifetime prevalence of low back pain from the young cohort in The Danish Twin Registry (aged 12-41) were analyzed with respect to heredity. Casewise concordance rates, odds ratios, tetrachoric correlation coefficients and biometric liability models were estimated in relation to gender and age. Finally, age-adjusted heritability of liability estimates were obtained. Both concordance rates and odds ratios show significant genetic influence on the liability to develop low back pain. Also, tetrachoric correlation coefficients show genetic influence, but this is not statistically significant for all age groups. The biometric modeling demonstrates shared environment to be a strong component in the youngest age group (12-15), but not above age 15, and it also demonstrates some non-additive genetic effects in the older age groups. Age-adjusted heritability of liability is estimated to 44% (37-50) for males and 40% (34-46) for females aged 16 to 41. Thus, the various analyses all demonstrate significant genetic influence on the liability to low back pain. The shared environment is an important component until age 15. After age 15, this component is unimportant. As people grow older, the effect of the non-shared environment increases and non-additive genetic effects become more evident, indicating an increasing degree of genetic interaction as age increases.     

Noise and the classical musician.

OBJECTIVES--To test the hypothesis that noise exposure may cause hearing loss in classical musicians. DESIGN--Comparison of hearing levels between two risk groups identified during the study by measuring sound levels. SETTING--Symphony orchestra and occupational health department in the west Midlands. MAIN OUTCOME MEASURES--Hearing level as measured by clinical pure tone audiometry. RESULTS--Trumpet and piccolo players received a noise dose of 160% and 124%, respectively, over mean levels during part of the study. Comparison of the hearing levels of 18 woodwind and brass musicians with 18 string musicians matched for age and sex did not show a significant difference in hearing, the mean difference in the hearing levels at the high (2, 4, and 8 KHz) audiometric frequencies being 1.02 dB (95% confidence interval -2.39 to 4.43). CONCLUSIONS--This study showed that there is a potential for occupational hearing loss in classical orchestral musicians.     

I-conotoxin superfamily revisited.

The I-conotoxin superfamily (I-Ctx) is known to have four disulfide bonds with the cysteine arrangement C-C-CC-CC-C-C, and the members inhibit or modify ion channels of nerve cells. Recently, Olivera and co-workers (FEBS J. 2005; 272: 4178-4188) have suggested that the previously described I-Ctx should now be divided into two different gene superfamilies, namely, I1 and I2, in view of their having two different types of signal peptides and exhibiting distinct functions. We have revisited the 28 entries presently grouped as I-Ctx in UniProt Swiss-Prot knowledgebase, and on the basis of in silico analysis have divided them into I1 and I2 superfamilies. The sequence analysis has provided a framework for in silico annotation enabling us to carry out computer-based functional characterization of the UniProtKB/TrEMBL entry Q59AA4 from Conus miles and to predict it as a member of the I2 superfamily. Furthermore, we have predicted the mature toxin of this entry and have proposed that it may be an inhibitor of voltage-gated potassium channels.     

Average heterozygosity revisited.

The estimate of heterozygosity and proportion of polymorphic loci for 33 red blood cell loci has been updated by the elimination of some loci of questionable status and the addition of data on 33 loci. The new figures for heterozygosity and proportion of polymorphic loci, .105 and .283, respectively, are based on 60 red blood cell loci of European origin populations. These values are less than those calculated by Lewontin in 1967, and furthermore they do not appear to be reaching an asymptote. At the present time, the red blood cell data and allozyme data for European populations have similar estimates of heterozygosity and proportion of polymorphic loci.     

Therapeutic peptides revisited.

After a roller coaster ride of successes and failures, new discovery technologies and advances in manufacturing promise a brighter future for peptides in human therapy.