Rare childhood diseases: how should we respond?

Paradoxically, rare diseases are common, collectively affecting 6-10% of the population and have a huge impact on patients and families, health services, clinicians and the wider community. Accurate data are required to inform clinical practice, government policy and health service planning. We recommend a national approach, similar to that adopted in the USA and Europe, to support research and promote advocacy and equitable access to services for children with rare diseases.

Molecular genotype analysis of Salmonella bovismorbificans

Genotypes were analysed within 30 isolates of Salmonella bovismorbificans from human or bovine salmonellosis and from environmental or food sources. Three clonal evolutionary lines (chromosomal genotypes) were identified on the basis of restriction fragment length polymorphism at the 16S rRNA genes, total protein profiles, and the location and copy number of a Salmonella-specific DNA insertion sequence, IS200. The predominant type was found with and without a 90 kbp plasmid homologous to the spv BC genes of S. typhimurium, and seven plasmid profiles were observed in this chromosomal genotype. This is the first such virulence plasmid to be reported in S. bovismorbificans. One example was found of two other clones which differed substantially from the predominant clone and from each other in chromosomal genotype. These results show that three clonal lines share the antigen profile of S. bovismorbificans, and provide a subtyping scheme for this serovar.

Epidemiological and immunological studies of sweet itch in horses in Israel

A survey of sweet itch in horses in Israel based on a questionnaire to owners reported that 158 of 723 horses (21.8 per cent) had sweet itch lesions. The results indicated that the likelihood of a horse acquiring sweet itch decreased with increasing altitude but no definite association with rainfall zones was evident. Variation in the density of the horse population, however, obscured these observations. In the population surveyed, stallions were more sensitive than mares and pale horses appeared to be less sensitive than dark ones, but the sample size of this latter group was much smaller. Intradermal injection of extracts of Culicoides imicola and Stomoxys calcitrans gave immediate reactions in sensitive horses but delayed reactions were observed only with extracts of C imicola. Sensitivity to extracts of C circumscriptus was also evident in allergic horses. Antibodies to extracts of Culicoides species and Stomoxys species were demonstrable in the serum of normal and allergic horses by the ELISA technique.

Effect of physical training on LDH activity and LDH isozyme pattern in human skeletal muscle

Total lactate dehydrogenase (LDH) activity and LDH isozyme pattern were studied in muscle biopsies obtained from m. vastus lateralis after 1) "aerobic" training performed as interval and extreme distance running, respectively (3 subjects); and 2) "anaerobic" training for two months, carried out as repeated maximal bursts of approximately 1 min running (6 subjects). After the "anaerobic training" no changes in LDH properties could be detected, although running performance improved. The extreme distance running resulted in a decrease in total LDH activity and an increase in relative activity of the heart specific isozymes. A relationship was also shown between the relative activity of these isozymes and the training distance covered. The relatively more aerobic prevailing during distance running as compared to "anaerobic training" were proposed to decrease muscle specific subunits and/or increase synthesis of heart specific subunits in both muscle fiber types. This suggestion was supported by isozyme analysis of lyophilized and dissected single muscle fibres.

LDH isozymes in skeletal muscles of endurance and strength trained athletes

Muscle biopsy samples were obtained from arm and leg muscles of endurance and strength trained athletes, respectively. Total LDH activity as well as occurrence and activity of LDH isozymes were determined. Comparing the results from the athletes with those from non-trained subjects with corresponding fibre compositions, it was found that the endurance athletes had a lower total LDH activity, a higher relative activity of the most heart-specific isozymes. LDH (1 + 2), and, on electrophoretic separation, a complete absence of LDH (4 + 5) in both arm and leg muscles. As compared to the untrained material the strength trained athletes tended to have a higher total LDH activity, a similar distribution of relative isozyme activities, and, in the leg muscles, a strong electrophoretic band corresponding to LDH 5, the most skeletal muscle specific isozyme.