Isolation and characterization of cDNAs encoding beta A2- and beta A4-crystallins: heterologous interactions in the predicted beta A4-beta B2 heterodimer

Except for the two acidic chains, beta A2 and beta A4, the primary structures of all bovine beta-crystallins have previously been elucidated, either by direct protein sequencing or prediction from cDNA sequencing. Both beta A2 and beta A4 were found to be synthesized in half-year-old calf lenses and are therefore likely to be present in a cDNA bovine library constructed from mRNA isolated from lenses of that age. A large number of cDNA clones was screened with all available crystallin, actin, vimentin and lens membrane protein MP26 probes and finally with a randomly primed mRNA probe. Clones positive for the latter, but negative for known lens proteins, were isolated and sequenced. beta A2, comprising 197 aa, and beta A4, comprising 209 aa, were identified. Both proteins have a conserved two-domain structure and an N-terminal extension which is variable. A three-dimensional model of the structure of beta A4 was made based on the coordinates of one subunit from the beta B2 dimer which has recently been solved using x-ray diffraction techniques. The resulting heterodimer structure, together with the compiled bovine beta-crystallin sequences, was used to indicate those regions of the sequences which distinguish acidic from basic beta-crystallins with a view to defining structural features necessary for subunit recognition in beta-crystallin aggregates. With the aid of the present data, the complete evolutionary tree of the bovine beta-crystallin family has been constructed, which confirms the early separation of the genes encoding the three acidic and the three basic beta-crystallins.     

Multi-centre parallel arm randomised controlled trial to assess the effectiveness and cost-effectiveness of a group-based cognitive behavioural approach to managing fatigue in people with multiple sclerosis

Background  

Fatigue is one of the most commonly reported and debilitating symptoms of multiple sclerosis (MS); approximately two-thirds of people with MS consider it to be one of their three most troubling symptoms. It may limit or prevent participation in everyday activities, work, leisure, and social pursuits, reduce psychological well-being and is one of the key precipitants of early retirement. Energy effectiveness approaches have been shown to be effective in reducing MS-fatigue, increasing self-efficacy and improving quality of life. Cognitive behavioural approaches have been found to be effective for managing fatigue in other conditions, such as chronic fatigue syndrome, and more recently, in MS. The aim of this pragmatic trial is to evaluate the clinical and cost-effectiveness of a recently developed group-based fatigue management intervention (that blends cognitive behavioural and energy effectiveness approaches) compared with current local practice.     

The Keen of Hamar,Shetland: A general survey and a census of some of the rarer plant taxa

Summary

Distribution and population size of six of the rarer plant species on the Keen of Hamar, including the endemic Cerastium arcticum ssp. edmondstonii, are presented. Changes in populations over recent years are described. The part of the Keen designated a National Nature Reserve includes many of the important geomorphological and botanical features of the site but excludes considerable numbers of rarities including most of the C. arcticum. Possible threats to the site and the need to enlarge the NNR are discussed.     

The effects of fertilization on part of the Keen of Hamar Serpentine,Shetland

Summary

Winter feeding of stock has caused eutrophication of the lower part of the Keen of Hamar. A nutrient addition experiment is reported which shows that grass cover of the serpentine debris increased greatly following phosphorus fertilization. Long-term observations have shown a substantial increase in grass cover over c. 35% of the lower part of the Keen and in one limited area the complete elimination of a rare species. It is suggested that the effects of eutrophication are likely to persist indefinitely and that it poses a major threat to this habitat and its rare plant species, although it seems that the site could be restored by removal of newly accumulated soil.     

Preliminary X-ray crystallographic study of the principal subunit of the lens structural protein,bovine β-crystallin

A principal subunit of the β-crystallins has been isolated and crystallized from bovine lens. The crystals are orthorhombic with unit cell dimensions $\text{a = 154·2}\text{A}\text{?}\text{, b = 165·2}\text{A}\text{?}\text{and}\text{c = 78·4}\text{A}\text{?}$, corresponding to two dimers of molecular weight 46,400 in the asymmetric unit. The crystals are pseudo-tetragonal, thus indicating that the pair of dimers are related by an approximate crystallographic dyad.