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A Emery

Publications and source records attributed to A Emery.

15 recordsLinked to original sources
PubMed2006

Development and application of an ethically and epidemiologically advantageous assay for the multi-locus microsatellite analysis of Schistosoma mansoni.

Non-availability of adult worms from living hosts remains a key problem in population genetic studies of schistosomes. Indirect sampling involving passage through laboratory animals presents significant ethical and practical drawbacks, and may result in sampling biases such as bottlenecking processes and/or host-induced selection pressures. The novel techniques reported here for sampling, storage and multi-locus microsatellite analysis of larval Schistosoma mansoni, allowing genotyping of up to 7 microsatellite loci from a single larva, circumvent these problems. The utility of these assays and the potential problems of laboratory passage, were evaluated using 7 S. mansoni population isolates collected from school-children in the Hoima district of Uganda, by comparing the associated field-collected miracidia with adult worms and miracidia obtained from a single generation in laboratory mice. Analyses of laboratory-passaged material erroneously indicated the presence of geographical structuring in the population, emphasizing the dangers of indirect sampling for population genetic studies. Bottlenecking and/or other sampling effects were demonstrated by reduced variability of adult worms compared to their parent field-collected larval samples. Patterns of heterozygote deficiency were apparent in the field-collected samples, which were not evident in laboratory-derived samples, potentially indicative of heterozygote advantage in establishment within laboratory hosts. Genetic distance between life-cycle stages in the majority of isolates revealed that adult worms and laboratory-passaged miracidia clustered together whilst segregating from field miracidia, thereby further highlighting the utility of this assay.

Alleles↗
PubMed1979

Proteolytic denaturation and methods of improving the stability of glucose isomerase preparations.

Evidence is provided in support of proteolytic denaturation of free and immobilized preparations of glucose isomerase from a Bacillus species. A number of methods to improve the stability with respect to proteolysis have been tested and their advantages as well as shortcomings are discussed. These methods include hollow-fiber treatment, gel permeation, thermal treatment, and addition of protease inhibitors. The half-life of the free and the cellulose acetate fiber-entrapped preparations of glucose isomerase can be significantly improved. For example, the hollow-fiber treatment can improve the half-life by an order of magnitude.

Acetates↗
PubMed1976

Characterization of sand as a support for immobilized enzymes.

The potential of sand as a support for immobilized enzymes was investigated by preparing alkylamine sand and devising methods to measure the total number of amine groups present and the fraction available for immobilization of enzymes. Alcohol dehydrogenase (alcohol: NAD oxidoreductase, EC 1.1.1.1.) and lactate dehydrogenase (L-lactate:NAD oxidoreductase, EC 1.1.1.27) were immobilized on alkylamine sand, and the stability of the immobilized protein and dehydrogenase activity was measured. Urease (urea amidohydrolase, EC 3.5.1.5) was also immobilized on sand to test the applicability of these methods to larger scale immobilizations. Results suggest that sand shows promise as a support for immobilized enzymes.

Alcohol Oxidoreductases↗
PubMedDate not supplied

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗
PubMedDate not supplied

European collaboration in research into rare diseases: experience of the European Neuromuscular Centre.

An understanding of the possible causes, prevention and treatment of rare, so-called 'orphan disease' requires collaboration in research between different centres with the sharing of information. In the case of neuromuscular disorders (such as muscular dystrophies or hereditary neuropathies) this has been achieved through European collaborative research encouraged and facilitated by the European Neuromuscular Centre (ENMC). The successful example of ENMC provides a model for the investigation of other rare 'orphan' disorders or even rare problems occurring in common disorders.

Cooperative Behavior↗