A study on the prevalence of and risk factors for neck pain among university academic staff in Hong Kong.

The 1-year prevalence of neck pain and possible risk factors among university academic staff were investigated. Self-administered questionnaires were distributed to all the full-time academic staff in one of the universities in Hong Kong. The 1-year prevalence of neck pain was investigated. The relationship between individual factors, job nature, psychosocial factors, and neck pain were also analyzed. The 1-year prevalence of neck pain among after being an academic staff was 46.7%. A significant association was found between gender and neck pain (p = 0.02). The percentage of female academic staff with neck pain (62%) was higher than that in male staff (38%). This matched the results of other studies, which demonstrated that neck pain was more prevalent in women. There was a significant association between head posture during computer processing and neck pain (p = 0.02). Among those with neck pain during computer processing, 60.5% had a forward head posture. However, a low correlation between psychosocial factors and neck pain was demonstrated (r = 0.343). Academic staff in tertiary institutions could be considered as a high-risk group of job-related neck pain.

Haplotype analysis of the myotonic dystrophy type 1 (DM1) locus in Taiwan: implications for low prevalence and founder mutations of Taiwanese myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is an autosomal dominant neuromuscular disorder caused by a CTG trinucleotide expansion at the DM1 locus. In this study, we investigated the frequency distribution of various CTG repeats in normal alleles and haplotyped the normal and expanded DM1 locus in a group of Taiwanese people. In the 496 normal chromosomes examined, up to 18 alleles with different CTG lengths from 5 to 30 repeats were found and the frequency of (CTG)(>18) alleles was only 1.4% (7/496), predicting a low prevalence of DM1. In addition, there is no absolute association between (CTG)(5-19) alleles and Alu insertion/deletion polymorphism observed on normal chromosomes. All DM1 alleles examined, however, were found to be associated with the Alu insertion. Further detailed genetic analysis demonstrated that at least eight haplotypes, including a new haplotype (L), were present in the Taiwanese population and that all DM1 alleles were with the same haplotype (haplotype A) as that identified in Canadian and Japanese DM1 populations. These findings support the notion that the out-of-Africa DM1 alleles were originated by stepwise expansion from a pool of large-sized normal chromosomes with haplotype A.

The crystal structure of the DNase domain of colicin E7 in complex with its inhibitor Im7 protein.

BACKGROUND: Colicin E7 (ColE7) is one of the bacterial toxins classified as a DNase-type E-group colicin. The cytotoxic activity of a colicin in a colicin-producing cell can be counteracted by binding of the colicin to a highly specific immunity protein. This biological event is a good model system for the investigation of protein recognition. RESULTS: The crystal structure of a one-to-one complex between the DNase domain of colicin E7 and its cognate immunity protein Im7 has been determined at 2.3 A resolution. Im7 in the complex is a varied four-helix bundle that is identical to the structure previously determined for uncomplexed Im7. The structure of the DNase domain of ColE7 displays a novel alpha/beta fold and contains a Zn2+ ion bound to three histidine residues and one water molecule in a distorted tetrahedron geometry. Im7 has a V-shaped structure, extending two arms to clamp the DNase domain of ColE7. One arm (alpha1(*)-loop12-alpha2(*); where * represents helices in Im7) is located in the region that displays the greatest sequence variation among members of the immunity proteins in the same subfamily. This arm mainly uses acidic sidechains to interact with the basic sidechains in the DNase domain of ColE7. The other arm (loop 23-alpha3(*)-loop 34) is more conserved and it interacts not only with the sidechain but also with the mainchain atoms of the DNase domain of ColE7. CONCLUSIONS: The protein interfaces between the DNase domain of ColE7 and Im7 are charge-complementary and charge interactions contribute significantly to the tight and specific binding between the two proteins. The more variable arm in Im7 dominates the binding specificity of the immunity protein to its cognate colicin. Biological and structural data suggest that the DNase active site for ColE7 is probably near the metal-binding site.

The crystal structure of the immunity protein of colicin E7 suggests a possible colicin-interacting surface.

The immunity protein of colicin E7 (ImmE7) can bind specifically to the DNase-type colicin E7 and inhibit its bactericidal activity. Here we report the 1.8-angstrom crystal structure of the ImmE7 protein. This is the first x-ray structure determined in the superfamily of colicin immunity proteins. The ImmE7 protein consists of four antiparallel alpha-helices, folded in a topology similar to the architecture of a four-helix bundle structure. A region rich in acidic residues is identified. This negatively charged area has the greatest variability within the family of DNase-type immunity proteins; thus, it seems likely that this area is involved in specific binding to colicin. Based on structural, genetic, and kinetic data, we suggest that all the DNase-type immunity proteins, as well as colicins, share a "homologous-structural framework" and that specific interaction between a colicin and its cognate immunity protein relies upon how well these two proteins' charged residues match on the interaction surface, thus leading to specific immunity of the colicin.

Crystallization and preliminary X-ray crystallographic analysis of ImmE7 protein of colicin E7.

The ImmE7 protein, which can bind specifically to the DNase colicin E7 and neutralize its bactericidal activity, has been purified and crystallized in two different crystal forms by vapor diffusion method. The orthorhombic crystals belong to space group I222 or I2(1)2(1)2(1) and have unit cell dimensions a = 75.1 A, b = 50.5 A, and c = 45.4 A. The second form is monoclinic space group P2(1) with cell dimensions a = 29.3 A, b = 102.7 A, c = 53.0 A, and beta = 91.5 degrees. The orthorhombic crystals diffract to 1.8 A resolution, and are suitable for high-resolution X-ray analysis.