Biomedical subjects

S Cheney

Publications and source records attributed to S Cheney.

3 recordsLinked to original sources

PubMed1999

Vairimorpha imperfecta n.sp., a microsporidian exhibiting an abortive octosporous sporogony in Plutella xylostella L. (Lepidoptera: Yponomeutidae).

The microsporidian genus Nosema is characterized by development in direct control with host cell cytoplasm, diplokaryotic nuclei throughout development and disporous sporogony. The genus Vairimorpha exhibits the same features plus an octoporous sporogony producing uninucleate spores in a sporophorous vesicle. A microsporidium from diamondback moth, Plutella xylostella, falls between Nosema and Vairimorpha in that it initiates but fails to complete the octosporous sequence in this host. The name Vairimorpha imperfecta n.sp. is proposed. Merogony is mainly by formation of buds from multinucleate meronts, the buds remaining attached in chains. Diplokaryotic spores measure 4.3 x 2.0 microns (fresh) and have 15.5 coils of the polar tube in 1 rank. The octosporous sporogony is aborted owing to irregular formation of nuclear spindles, incomplete cytoplasmic fission and bizarre deposition of electron-dense episporontal secretions. Phylogenetic analyses of the sequences of the small subunit rRNA genes of V. imperfecta and of several Nosema and Vairimorpha spp. place V. imperfecta in a clade with Nosema spp. from Lepidoptera rather than in the clade containing the more typical species of Vairimorpha. It is suggested that the ancestors of the Vairimorpha/Nosema complex of species exhibited both disporous and octosporous sporogonies, as does the type species of Vairimorpha, Vairimorpha necatrix. It would follow that true Nosema spp. have lost the ability to express an octosporous sequence and that V. imperfecta is in the process of losing it. It is proposed that the genera Nosema and Vairimorpha be placed in the same family Nosematidae Labbé 1899, rather than in separate families and orders as at present.

Animals↗

PubMed1996

The impact of the Medicare Influenza Demonstration Project on influenza vaccination in a county in Massachusetts, 1988-1992.

Influenza and related pneumonia continue to cause significant amounts of morbidity and mortality despite the availability of effective vaccines. Two comparable counties in Massachusetts served as project areas of a national trial to see if reimbursement for immunizing Medicare-B eligible recipients against influenza would increase the use of the vaccine and reduce the costs attributed to related morbidity. Providers of health and social services to elders were recruited to participate in one county. A variety of professional and public education campaigns and media were used to promote influenza immunizations. Laboratory-based surveillance was instituted in both counties to assess the extent of circulating virus in each. Vaccine was made available to medical providers in both counties. While the amount of vaccine used in the comparison county increased by 6% from pre-project time (16,000 to 17,000 doses administered), vaccine use increased 219% in the intervention county (21,250 to 46,494 doses administered). In a post-project survey of participating physicians, 88% of 238 respondents reported administering less than 100 doses of influenza vaccine per year prior to the project. By the end of the project, only 32% administered less than 100 in the previous year. This project demonstrated the need for educating both the provider and the public in order to successfully promote immunizations. It was not clear, however, if reimbursement was a more important factor for promoting influenza immunizations than was universal distribution of free vaccine.

Aged↗

PubMed1978

Nursing legislation.

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Legislation, Nursing↗