Gene loss and silencing in Tragopogon miscellus (Asteraceae): comparison of natural and synthetic allotetraploids.

Whole-genome duplication (polyploidisation) is a widespread mechanism of speciation in plants. Over time, polyploid genomes tend towards a more diploid-like state, through downsizing and loss of duplicated genes (homoeologues), but relatively little is known about the timing of gene loss during polyploid formation and stabilisation. Several studies have also shown gene transcription to be affected by polyploidisation. Here, we examine patterns of gene loss in 10 sets of homoeologues in five natural populations of the allotetraploid Tragopogon miscellus that arose within the past 80 years following independent whole-genome duplication events. We also examine 44 first-generation synthetic allopolyploids of the same species. No cases of homoeologue loss arose in the first allopolyploid generation, but after 80 years, 1.6% of homoeologues were lost in natural populations. For seven homoeologue sets we also examined transcription, finding that 3.4% of retained homoeologues had been silenced in the natural populations, but none in the synthetic plants. The homoeologue losses and silencing events found were not fixed within natural populations and did not form a predictable pattern among populations. We therefore show haphazard loss and silencing of homoeologues, occurring within decades of polyploid formation in T. miscellus, but not in the initial generation.

Residential proximity to industry and adverse birth outcomes.

We studied birth statistics in women living at varying proximity to major steel and petrochemical industries in Teesside, UK. We found no evidence to support the hypothesis that living close to these major industries led to adverse birth outcomes.

Does living near a constellation of petrochemical, steel, and other industries impair health?

OBJECTIVES: To investigate concern that local industrial air pollution in Teesside, England, was causing poor health, several areas there were compared with parts of the City of Sunderland. METHODS: Populations in similar social and economic circumstances but varying in their proximity to major industries were compared. Study populations lived in 27 housing estates in Teesside and Sunderland, north east England, with some data from subsets of estates. The estates were aggregated into zones (designated as A, B, and C in Teesside where A is closest to and C furthest from industry, and S in Sunderland). Zone S provided a reference area. The hypothesis was that a health gradient both within Teesside (A > B > C) and between Teesside and Sunderland (ABC > S) would indicate a possible health effect of local industrial air pollution. Data presented were: mortality (1981-91) from 27 housing estates; population self completion questionnaire survey data (1993, 9115 subjects) from 15 housing estates; and general practitioner (GP) consultation data (1989-94) from 2201 subjects in 12 Teesside estates. RESULTS: The populations in the four zones were comparable for indicators including smoking habits, residential histories, and unemployment. All cause and cause specific mortalities were high compared with England and Wales. Mortality in all Teesside zones (ABC) combined was mostly higher than in zone S. In people aged 0-64, lung cancer and respiratory disease showed gradients with highest mortality in areas closest to industry (A > B > C and ABC > S). The association was clearest for lung cancer in women (0-64 years old, trend across zones ABC, p = 0.07, directly standardised rate ratio relative to zone S was 169 (95% confidence interval (95% CI) 116-122)). There were no important, consistent gradients in the hypothesised direction between zones in consultation rates in general practice, and self reported respiratory and nonrespiratory health including asthma. CONCLUSIONS: There was no clear evidence that living close to industry was associated with morbidity, including asthma, or for most measures of mortality. For lung cancer in women the gradients indicated a health effect of local industrial air pollution. In the age group 0-64 observed gradients in lung cancer in men and mortality from respiratory disease in men and women were consistent with the study hypothesis, although not significant. The reasons for the different patterns at different ages, and between men and women, remain a puzzle.

Clinical trial in post-addicts with oxilorphan (levo-BC-2605): a new narcotic antagonist.

Oxilorphan (levo-BC-2605) is a new, long-acting, narcotic antagonist that has agonist properties. Twenty-one (21) heroin addicts in Los Angeles were detoxified and given at least one oral dose of oxilorphan. Only three (14.3%) patients took daily doses for 14 days, which was the maximal time allowed for oxilorphan administration in this study. The remainder discontinued oxilorphan because of subjective side effects or for unknown reasons. Side effects most responsible for dropouts were dysphoria, insomnia, weakness, hallucinations, nausea, drowsiness and anorexia. Oxilorphan provided 24-hour protection with a single, oral dose, but subjective side effects encountered during inductiolinical trials with oxilorphan should be attempted with other addict populations to fully determine its potential therapeutic value.