Preliminary Survey of Ectoparasites and Associated Pathogens from Norway Rats in New York City.

The Norway rat (Rattus norvegicus) is a reservoir of many zoonotic pathogens and lives in close proximity to humans in urban environments. Human infection with rodent-borne disease occurs either directly through contact with a rat or its excreta, or indirectly via arthropod vectors such as fleas and ticks. Here, we report on the diversity and abundance of ectoparasitic arthropod species and associated pathogenic bacteria from 133 Norway rats trapped over a 10-mo period in Manhattan, New York, NY. Norway rats were host to the tropical rat mite [Ornithonyssus bacoti (Hirst)], the spiny rat mite (Laelaps echidnina Berlese), Laelaps nuttalli Hirst, the spined rat louse [Polyplax spinulosa (Burmeister)], and the Oriental rat flea [(Xenopsylla cheopis) (Rothschild)], with an average of 1.7 species per individual. A flea index of 4.1 X. cheopis was determined, whereas previous studies in New York City reported 0.22 fleas per rat. Multiple species of pathogenic Bartonella were identified from Oriental rat fleas that were related to Bartonella tribocorum, Bartonella rochalimae, and Bartonella elizabethae. However, no evidence of Yersinia pestis or Rickettsia spp. infection was detected in fleas. The identification of multiple medically important ectoparasite species in New York City underscores the need for future efforts to fully characterize the diversity and distribution of ectoparasites on Norway rats, and assess the risk to humans of vector-borne disease transmission.

Incorporation of antigens from Mannheimia haemolytica culture supernatant, and recombinant bovine C3d into ISCOM matrix using neutravidin-biotin interaction.

The aim of this study was to incorporate antigens from Mannheimia haemolytica culture supernatant, and an immune modulatory molecule, recombinant bovine C3d (rBoC3d), into immune stimulating complexes (ISCOMs) using neutravidin-biotin interaction. Biotinylated ISCOM matrix was generated using a commercial kit. The biotinylated ISCOM matrix was incubated with neutravidin and then centrifuged in a sucrose density gradient. The rBoC3d was expressed as an in vivo biotinylated protein and with a c-Myc tag (EQKLISEEDL) engineered to facilitate detection. The neutravidin-coated ISCOM matrix was incubated with biotinylated antigens from M. haemolytica culture supernatants and rBoC3d. To test the association among the neutravidin-coated ISCOM matrix, biotinylated antigens and rBoC3d, an analytical sucrose density gradient (10-40%, w/w) was performed. The experimental formulations were run in SDS-PAGE gels under reducing conditions. For Western immunoblot analysis, polyclonal bovine antiavidin, monoclonal anti-c-Myc, monoclonal antileukotoxin, and anti-GS60 antibodies were used to detect the presence of neutravidin, rBoC3d, leukotoxin, and GS60 antigens, respectively. By taking advantage of the biotin-neutravidin interaction, not only leukotoxin but also the recombinant immunomodulatory molecule, rBoC3d, was incorporated into ISCOM particles.

Genome-wide pharmacogenetic investigation of a hepatic adverse event without clinical signs of immunopathology suggests an underlying immune pathogenesis.

One of the major goals of pharmacogenetics is to elucidate mechanisms and identify patients at increased risk of adverse events (AEs). To date, however, there have been only a few successful examples of this type of approach. In this paper, we describe a retrospective case-control pharmacogenetic study of an AE of unknown mechanism, characterized by elevated levels of serum alanine aminotransferase (ALAT) during long-term treatment with the oral direct thrombin inhibitor ximelagatran. The study was based on 74 cases and 130 treated controls and included both a genome-wide tag single nucleotide polymorphism and large-scale candidate gene analysis. A strong genetic association between elevated ALAT and the MHC alleles DRB1(*)07 and DQA1(*)02 was discovered and replicated, suggesting a possible immune pathogenesis. Consistent with this hypothesis, immunological studies suggest that ximelagatran may have the ability to act as a contact sensitizer, and hence be able to stimulate an adaptive immune response.

PRO_SELECT: combining structure-based drug design and combinatorial chemistry for rapid lead discovery. 1. Technology.

This paper describes a novel methodology, PRO_SELECT, which combines elements of structure-based drug design and combinatorial chemistry to create a new paradigm for accelerated lead discovery. Starting with a synthetically accessible template positioned in the active site of the target of interest, PRO_SELECT employs database searching to generate lists of potential substituents for each substituent position on the template. These substituents are selected on the basis of their being able to couple to the template using known synthetic routes and their possession of the correct functionality to interact with specified residues in the active site. The lists of potential substituents are then screened computationally against the active site using rapid algorithms. An empirical scoring function, correlated to binding free energy, is used to rank the substituents at each position. The highest scoring substituents at each position can then be examined using a variety of techniques and a final selection is made. Combinatorial enumeration of the final lists generates a library of synthetically accessible molecules, which may then be prioritized for synthesis and assay. The results obtained using PRO_SELECT to design thrombin inhibitors are briefly discussed.

MOLMAKER: de novo generation of 3D databases for use in drug design.

A program, MOLMAKER, is described which, in conjunction with a 2D-3D conversion program and 3D database software, can generate de novo 3D databases to aid in drug design. MOLMAKER is based upon graph-theoretical techniques for vertex degree set generation and constructive enumeration of molecular graphs. The generated molecular graphs are then functionalised in a probabilistic manner but in accordance with various constraints specified by the user. The resulting connection tables can be converted into 3D structures by commercial software and loaded into a 3D database for pharmacophore searching. The utility of MOLMAKER is illustrated by two examples of interest from the recent scientific literature: the design of novel protein kinase C agonists and of a bridging ligand for cyclophilin-calcineurin.

Protein fold recognition by threading: comparison of algorithms and analysis of results.

Optimal sequence threading can be used to recognize members of a library of protein folds which are closely related in 3-D structure to the native fold of an input test sequence, even when the test sequence is not significantly homologous to the sequence of any member of the fold library. The methods provide an alignment between the residues of the test sequence and the residue positions in a template fold. This alignment optimizes a score function, and the predicted fold is the highest scoring member of the library of folds. Most score functions contain a pairwise interaction energy term. This, coupled with the need to introduce gaps into the alignment, means that the optimization problem is NP hard. We report a comparison between two heuristic optimization algorithms used in the literature, double dynamic programming and an iterative algorithm based on the so-called frozen approximation. These are compared in terms of both the ranking of likely folds and the quality of the alignment produced.

Research note: the use of the Birleson Depression Scale with a non-clinical sample of boys.

Attempts have been made to develop self-rating scales to assess depression in children. One of these scales, the Birleson Self-rating Scale, was administered to a non-clinical sample of boys which was larger, and covered a wider age-range, than Birleson's own non-clinical group. A comparison is made with Birleson's findings, and in addition data from the administration of the scale to a group of boys aged 13 to 18 years is presented.

Screening the newborn for Duchenne muscular dystrophy: parents' views.

KIE: A short report is provided of an interview survey of 69 parents of boys suffering from Duchenne muscular dystrophy to determine their views of neonatal screening and their experiences at the time of diagnosis. Most of the parents favored screening in the neonatal period or in early infancy, and most of them expressed dissatisfaction with present delays, methods of disclosure, and subsequent support.^ieng

Diagnosis of Duchenne muscular dystrophy: experiences of parents of sufferers.

Sixty nine parents of boys suffering from Duchenne muscular dystrophy were interviewed at home. The interview explored the parents' experiences at the time of their son's diagnosis. Many families had experienced distressing delays (average 2.5 years) between the time they first became aware of symptoms and the time of the diagnosis. On only 18 occasions were both parents told of the diagnosis together. One third of the parents were "not satisfied" with the way the diagnosis had been communicated. Parents want to know as soon as possible if there is something wrong with their child. They should be told the diagnosis together and in private. Full information should be given and a series of contacts should be arranged.