A chemotaxonomic survey of kaurene derivatives in the genus Alepidea (Apiaceae)

Lipophilic extracts from the roots of 16 species of Alepidea were studied by GC-MS for the presence of kaurenoic acids, dehydrokaurenoic acids, kaurenic lactones, hydroxykaurenoic acids and other kaurene derivatives. Various mixtures of these compounds are present in yields of up to 11.8% dry wt. in the rhizomes and roots. Two different isomers of kaurenoic acid occur in Alepidea, the one as a major compound in all the species, the other as a major compound only in some of them. The first isomer is clearly a useful chemical marker for the genus Alepidea, but the apparent chemical dichotomy is not obviously correlated with morphological patterns. Alepidea amatymbica, however, is part of a morphologically isolated group within the genus and also differs from other species in its chemical complexity and in the unique presence of kaurenoic lactones.     

Identification of Medicare Recipients at Highest Risk for Clostridium difficile Infection in the US by Population Attributable Risk Analysis

Background

Population attributable risk percent (PAR%) is an epidemiological tool that provides an estimate of the percent reduction in total disease burden if that disease could be entirely eliminated among a subpopulation. As such, PAR% is used to efficiently target prevention interventions. Due to significant limitations in current Clostridium difficile Infection (CDI) prevention practices and the development of new approaches to prevent CDI, such as vaccination, we determined the PAR% for CDI in various subpopulations in the Medicare 5% random sample.

Methods

This was a retrospective cohort study using the 2009 Medicare 5% random sample. Comorbidities, infections, and healthcare exposures during the 12 months prior to CDI were identified. CDI incidence and PAR% were calculated for each condition/exposure. Easy to identify subpopulations that could be targeted from prevention interventions were identified based on PAR%.

Findings

There were 1,465,927 Medicare beneficiaries with 9,401 CDI cases for an incidence of 677/100,000 persons. Subpopulations representing less than 15% of the entire population and with a PAR% ≥ 30% were identified. These included deficiency anemia (PAR% = 37.9%), congestive heart failure (PAR% = 30.2%), fluid and electrolyte disorders (PAR% = 29.6%), urinary tract infections (PAR% = 40.5%), pneumonia (PAR% = 35.2%), emergent hospitalization (PAR% = 48.5%) and invasive procedures (PAR% = 38.9%). Stratification by age and hospital exposures indicates hospital exposures are more strongly associated with CDI than age.

Significance

Small and identifiable subpopulations that account for relatively large proportions of CDI cases in the elderly were identified. These data can be used to target specific subpopulations for CDI prevention interventions.     

Specifically deuterated and tritiated auxins

Regiospecific syntheses of monodeuterated and monotritiated natural auxin (indole- 3-acetic acid), a synthetic auxin (naphthalene-1-acetic acid) and a photoaffinity labeling auxin (5-azidoindole-3-acetic acid) are described. These syntheses provide benzene-ring tritiated auxins for use in reversible and covalent binding studies.     

Persistent measles virus infection of a clonal line of neuroblastoma: Effect on neural differentiation

Murine neuroblastoma cells, chronically infected with measles virus were examined for changes in neural-specific function and structure as well as cellular growth and macromolecular synthesis. When exposed to neural differentiation-inducing culture conditions, neurite formation and acetylcholinesterase activity are significantly increased in control cultures but not in persistently infected cells. Infected cultures manifest a more rapid doubling time, but depressed RNA and protein synthesis at saturation densities. Higher concentrations of papavarine, a cyclic 3′–5′ AMP phosphodiesterase inhibitor, result in selective death of persistently infected cells.     

Ultrastructural Study of Long-Term Measles Infection in Cultures of Hamster Dorsal-Root Ganglion

The morphogenesis of the Edmonston strain of measles is described in cultures of hamster dorsal-root ganglion maintained for as long as 63 days postinoculation. The patterns observed confirmed those previously reported in both neural and non-neural tissue. However, in the present tissue, the development of viral material could be followed chronologically within different cell types such as neurons and Schwann cells. Active replication was visualized up to 63 days postinoculation. The appearance of cytoplasmic nucleocapsid preceded that of intranuclear nucleocapsid, the latter occurring after 14 days. These intranuclear inclusions were formed after the transformation of the nucleoli into bizarre pleomorphic bodies which eventually segregated into clumps of nucleocapsid. These intranuclear inclusions mimic those seen in subacute sclerosing panencephalitis, now known to be etiologically related to a measles-like virus.     

Experimental allergic encephalomyelitis in the guinea pig: Variation in peripheral blood lymphocyte responsiveness to myelin basic protein during disease development

Peripheral blood lymphocytes (PBL) from guinea pigs with experimental allergic encephalomyelitis (EAE) induced by sensitization with bovine whole white matter, proliferated in vitro upon exposure to bovine myelin basic protein (B-MBP). The degree of the response increased with clinical severity. PBL from EAE-sensitized guinea pigs which failed to develop clinical disease did not respond to B-MBP. PBL from complete Freund's adjuvant-sensitized and nonsensitized normal guinea pigs were not responsive to B-MBP. EAE-sensitized animals displaying clinical signs of disease showed concanavalin A (Con A) responsiveness which paralleled that of B-MBP. Animals that did not develop EAE demonstrated Con A responses similar to those of control guinea pigs. Thus, in this acute autoimmune demyelinating condition, PBL responsiveness to B-MBP might provide a monitor of disease development.