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Biomedical subjects

Richard J Pollack

Publications and source records attributed to Richard J Pollack.

6 recordsLinked to original sources

A travel medicine guide to arthropods of medical importance.

Guidance has been offered to clinicians so they might better educate and advise travelers how to protect themselves, and evaluate complaints by travelers once they have returned. Any biting arthropod may cause direct injury, and the bite of just one infectious vector can be enough to prove fatal to the unprotected. Travelers and travel medicine practitioners should familiarize themselves with the vectors and vector-borne agents likely to been countered corresponding to the traveler's specific itinerary, accommodations, and planned activities, and devise a rational strategy to reduce risk.

Animals↗

A readily constructed lard-can trap for sampling host-seeking mosquitoes.

Although lard-can traps have been used for sampling host-seeking mosquitoes for at least a half-century, the materials from which they originally were constructed no longer are available. We therefore devised a method for constructing such devices from parts available in the ventilation industry. These traps, baited with birds and mounted near the tops of trees, were employed to monitor the host-seeking activity of Culex spp. mosquitoes. Lard-can traps, constructed in this manner, are economical and sturdy and effectively sample the Culex mosquitoes that appear to perpetuate West Nile virus in North America.

Animals↗

Transcriptome identification of putative genes involved in protein catabolism and innate immune response in human body louse (Pediculicidae: Pediculus humanus).

Genomics information relating to human body lice is surprisingly scarce, and this has constrained studies of their physiology, immunology and vector biology. To identify novel body louse genes, we used engorged adult lice to generate a cDNA library. Initially, 1152 clones were screened for inserts, edited for removal of vector sequences and base pairs of poor quality, and viewed for splicing variations, gene families and polymorphism. Computational methods identified 506 inferred open reading frames including the first predicted louse defensin. The inferred defensin aligns well with other insect defensins and has highly conserved cysteine residues, as are known for other defensin sequences. Two cysteine and five serine proteinases were categorized according to their inferred catalytic sites. We also discovered seven putative ubiquitin-pathway genes and four iron metabolizing deduced enzymes. Finally, glutathione-S-transferases and cytochrome P450 genes were among the detoxification enzymes found. Results from this first systematic effort to discover human body louse genes should promote further studies in Phthiraptera and lice.

Amino Acid Sequence↗

A component of maize pollen that stimulates larval mosquitoes (Diptera: Culicidae) to feed and increases toxicity of microbial larvicides.

To explain how larval Anopheles arabiensis Patton feed effectively in the turbid water in which they frequently develop, we determined whether an extractable component of maize, Zea mays L., pollen enhances feeding by these mosquitoes. Maturing maize produces a copious amount of wind-borne pollen that is nutritious enough and produced over a sufficient period to support the development of at least one generation of anopheline mosquitoes. Larval An. arabiensis readily ingest the contents of maize pollen or the intact pollen grains themselves. An aqueous extract of maize pollen markedly accelerates the rate at which larval An. arabiensis ingest inert particles and strongly enhances the effectiveness of Bti against larval An. arabiensis. We conclude that the ability of larval anopheline mosquitoes to feed on maize pollen in turbid water is enhanced by the release from these pollen grains of a water-soluble phagostimulatory component (or components), which may be used to increase ingestion of microbial entomotoxins.

Animals↗

Enhancement of development of larval Anopheles arabiensis by proximity to flowering maize (Zea mays) in turbid water and when crowded.

To determine whether proximity to flowering maize enhances the development of larval anopheline mosquitoes breeding in turbid water and when crowded, we evaluated the development of larval Anopheles arabiensis under various conditions of turbidity, larval density, and proximity to pollen-shedding maize in simulated breeding puddles in a malaria-endemic site. In naturally formed puddles, water turbidity, as well as larval density, increased as the rainy season progressed. In sites remote from flowering maize, more pupae developed and the resulting adults were larger in relatively clear water than in turbid water, and larval crowding inhibited development. In close proximity to flowering maize, however, larval development was little affected by water turbidity and larval crowding. Larvae of this member of the African An. gambiae complex of mosquitoes develop readily in turbid water and when crowded, provided that their breeding sites are located where maize pollen is abundant.

Animals↗