Resistance to antiparasitic drugs: the role of molecular diagnosis.

Chemotherapy is central to the control of many parasite infections of both medical and veterinary importance. However, control has been compromised by the emergence of drug resistance in several important parasite species. Such parasites cover a broad phylogenetic range and include protozoa, helminths and arthropods.

Sustainable coccidiosis control in poultry production: the role of live vaccines.

The development of new methods of administering coccidiosis vaccines has facilitated their use in the hatchery and thereby improved prospects for the economic vaccination of broilers. The acquisition of protective immunity to Eimeria species is boosted by further exposure to infection after vaccination. Factors that affect the reproductive efficiency of non-attenuated and attenuated vaccines are considered and the key role that oocyst production plays in establishing and maintaining uniform immunity in a flock of chickens is discussed.

Impact of landscape management on the genetic structure of red squirrel populations.

Landscape management practices that alter the degree of habitat fragmentation can significantly affect the genetic structure of animal populations. British red squirrels use "stepping stone" patches of habitat to move considerable distances through a fragmented habitat. Over the past few decades, the planting of a large conifer forest has connected groups of forest fragments in the north of England with those in southern Scotland.

Modelling host cell availability and the crowding effect in Eimeria infections.

Within-host mathematical models of Eimeria maxima and Eimeria praecox infections of the chicken are presented and used to investigate the role of host cell availability as a possible determinant of the so-called 'crowding effect'; whereby the fecundity of the parasites decreases as infectious dose increases. Assumptions about the number of available host cells, the average lifespan of these cells and the age structure within the host-cell population were made and mathematical models were constructed and combined with experimental data to test whether these conditions could reproduce the crowding effect in the two species. Experimental data demonstrated that crowding during in vivo infections was apparent following very low infectious doses, but none of the models could adequately reproduce crowding at the same doses while maintaining realistic estimates of the dynamics of the enterocyte pool.

Mapping and expression of microneme genes in Eimeria tenella.

Microneme organelles are located at the apical tip of invading stages of all apicomplexan parasites and they contain proteins that are critical for parasite adhesion to host cells. In this paper, we have utilised the process of oocyst sporulation in Eimeria tenella to investigate the timing of expression of components of the microneme organelle, at both mRNA and protein levels. Two time-course studies showed that there is a high level of synchrony in the sporulation process, especially during the time period when sporozoites are formed.

Bexarotene metabolism in rat, dog, and human, synthesis of oxidative metabolites, and in vitro activity at retinoid receptors.

The metabolism of bexarotene, a rexinoid recently approved in the United States for treatment of cutaneous T-cell lymphoma, was studied using liver slices from untreated rats and dogs, liver microsomes from untreated and pretreated rats, and pooled human liver microsomes. Metabolite profiles were examined in bile and plasma from rats and dogs, and plasma from humans treated with bexarotene. Four metabolites, racemic 6-hydroxy-bexarotene, racemic 7-hydroxy-bexarotene, 6-oxo-bexarotene, and 7-oxo-bexarotene, were synthesized and their binding to, and transactivation of retinoid receptors were examined.

Successful VATS ligation of a large anomalous branch producing IMA steal syndrome after MIDCAB.

The occurrence of a flow "steal phenomenon" from a large branch of the internal mammary artery (IMA) is rare and its pathogenesis is still controversial. We describe a case of a patent large anomalous left IMA branch which produced recurrent angina 3 years post MIDCAB. Transcatheter coil obliteration of the vessel produced symptomatic relief.

A genetic linkage map of the apicomplexan protozoan parasite Eimeria tenella.

Apicomplexan protozoan parasites have complex life cycles that involve phases of asexual and sexual reproduction. Some genera have intermediate insect hosts, for example, Plasmodium spp. (the cause of malaria), but related genera such as Eimeria spp.

9-cis-Retinoic acid suppresses mammary tumorigenesis in C3(1)-simian virus 40 T antigen-transgenic mice.

Retinoids have been investigated as potential agents for the prevention and treatment of human cancers. These compounds play an important role in regulating cell growth, differentiation, and apoptosis. 9-cis-Retinoic acid (9cRA) is a naturally occurring ligand with a high affinity for both the retinoic acid receptors and the retinoid X receptors.

A survey of genes in Eimeria tenella merozoites by EST sequencing.

A study of about 500 expressed sequence tags (ESTs), derived from a merozoite cDNA library, was initiated as an approach to generate a larger pool of gene information on Eimeria tenella. Of the ESTs, 47.7% had matches with entries in the databases, including ribosomal proteins, metabolic enzymes and proteins with other functions, of which 14.

Comparative fermentation studies of industrial strains belonging to four species of solvent-producing clostridia.

Industrial and culture collection strains of solvent-producing clostridia, classified as Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharobutylicum, and Clostridium saccharoperbutylacetonicum were utilised in a comparative study of fermentation performance in a laboratory fermentation medium, a molasses fermentation medium, and a maize fermentation medium under standardised culture conditions. At least one representative strain was selected from each of the sub-groups within the four species. Preliminary evaluations were first undertaken for the three different fermentation media to determine the most appropriate media formulations, carbohydrate concentrations, and culture conditions for comparison of the solvent-producing ability of these strains.

Bacteriophage infections in the industrial acetone butanol (AB) fermentation process.

The reported incidence and effects of bacteriophage infections occurring in the industrial acetone butanol (AB) fermentation processes operated in the USA, Japan, and Puerto Rico during the earlier part of the twentieth century is reviewed. The growth characteristics and solvent-producing ability of a lysogenic strain of Clostridium madisonii isolated from a phage infection in Puerto Rico was determined in molasses fermentation medium. The host strain harbours a large lysogenic phage belonging to the Siphoviridae and the growth rate of the lysogenic strain was found to be slower than the non-lysogenic parent strain and exhibited reduced solvent production.

The genome of Eimeria spp., with special reference to Eimeria tenella--a coccidium from the chicken.

Eimeria spp. contain at least four genomes. The nuclear genome is best studied in the avian species Eimeria tenella and comprises about 60 Mbp DNA contained within ca.

Immunological aspects of infections with Eimeria maxima: A short review.

Eimeria maxima is one of the seven species of protozoan parasites that cause intestinal coccidiosis in chickens. Discovered and first described exactly 70 years ago, the parasite has some unique features that both distinguish it from the other members of the genus and make it of relevance to the world's poultry industry. Of special interest is the balanced immunological relationship that E.

False-positive maintenance of self-injurious behavior by access to tangible reinforcers.

Results of a functional analysis indicated that the hand mouthing of a woman with developmental disabilities was maintained by multiple sources of control (sensory stimulation and access to a leisure item). Further assessment revealed that access to several other items also produced high rates of hand mouthing. However, direct observation conducted in the woman's home indicated that none of these items was delivered contingent upon hand mouthing.

GENETIC BASIS OF A BETWEEN-ENVIRONMENT TRADE-OFF INVOLVING RESISTANCE TO CADMIUM IN DROSOPHILA MELANOGASTER.

In a replicated, laboratory, natural selection experiment Drosophila melanogaster populations were maintained for 20 generations either on unpolluted medium or on polluted medium containing cadmium chloride at a concentration of 80 μg/ml. Lines maintained on polluted medium evolved resistance. In comparison with unpolluted lines, their juvenile survivorship increased from 35% to 46%, developmental period decreased from 13.

Characterisation of a Cryptosporidium parvum-specific cDNA clone and detection of parasite DNA in mucosal scrapings of infected mice.

A cDNA library was constructed using total RNA extracted from oocysts and sporozoites of the protozoan parasite Cryptosporidium parvum. The expression library was screened with an anti-C. parvum antiserum and a clone, Cp3.

A HPLC method for the determination of 9-cis retinoic acid (ALRT1057) and its 4-oxo metabolite in human plasma.

A HPLC method was developed and validated for the quantitation of 9-cis-retinoic acid (ALRT1057) and its major metabolite, 4-oxo-9-cis-retinoic acid (LG100182) in human plasma. Samples were buffered and extracted with methyl-tert-butyl-ether. The analytes and an I.

Effects of retinoid treatment of rats on hepatic microsomal metabolism and cytochromes P450. Correlation between retinoic acid receptor/retinoid x receptor selectivity and effects on metabolic enzymes.

Retinoids are compounds that bind to and activate one or more retinoid receptors to elicit various physiological responses. There are two families of retinoid receptors, i.e.

Mapping the genome of Eimeria tenella: use of a yeast artificial chromosome library as the basis for a physical map.

Efforts to derive a physical map of the genome of Eimeria tenella are being made to complement genetic mapping and to assist in the production of an integrated map. A large insert library of DNA from the Houghton (H) reference strain of E. tenella has been constructed in yeast artificial chromosomes (YACs).

Oxidative metabolism of a rexinoid and rapid phase II metabolite identification by mass spectrometry.

LGD1069 (Targretin), a retinoid "X" receptor-selective ligand, or rexinoid, is in clinical trials for treating cancer. Biologically-active oxidized LGD1069 metabolites have been observed in patient plasma samples, making corresponding structural characterizations necessary. Formation of multiple metabolite isomers in vivo has created technical challenges in metabolite structural analysis; however, mass spectrometry (MS) was able to pinpoint two sites of Phase I metabolism.

Does functional communication training compete with ongoing contingencies of reinforcement? An analysis during response acquisition and maintenance.

We examined the effectiveness of functional communication training (FCT) in reducing self-injurious behavior (SIB) and in shaping an alternative (communicative) response while SIB continued to be reinforced. Following a functional analysis of 3 individuals' SIB, we attempted to teach an alternative response consisting of a manual sign to each individual, using the reinforcer that maintained SIB. When FCT was implemented without extinction.

Life-time problem drinking and psychiatric co-morbidity among Ontario women.

Women problem drinkers in the community, aged 15-64 years, with and without life-time psychiatric co-morbidity were compared to examine the association of this co-morbidity with alcohol consumption patterns, course and chronicity of problem drinking, treatment service utilization and other substance use and misuse. The women problem drinkers were also compared with non-problem drinkers on substance use patterns and utilization of services. The study employs data from the Mental Health Supplement to the Ontario Health Survey, a province-wide household population study.