Rapid speciation via the evolution of pre-mating isolation in the Iberá Seedeater.

Behavioral isolation can catalyze speciation and permit the slow accumulation of additional reproductive barriers between co-occurring organisms. We illustrate how this process occurs by examining the genomic and behavioral bases of pre-mating isolation between two bird species (Sporophila hypoxantha and the recently discovered S. iberaensis) that belong to the southern capuchino seedeaters, a recent, rapid radiation characterized by variation in male plumage coloration and song. Although these two species co-occur without obvious ecological barriers to reproduction, we document behaviors indicating species recognition by song and plumage traits and strong assortative mating associated with genomic regions underlying male plumage patterning. Plumage differentiation likely originated through the reassembly of standing genetic variation, indicating how novel sexual signals may quickly arise and maintain species boundaries.

Genotoxic effects of Roundup Full II® on lymphocytes of Chaetophractus villosus (Xenarthra, Mammalia): In vitro studies.

In Argentina, Chaetophractus villosus has a wide distribution that overlaps with agricultural areas where soybean is the predominant crop. In such areas the pesticide Roundup Full II® (RU) is widely applied. The genotoxic effect of its active ingredient glyphosate (RU is 66.2% glyphosate) on the peripheral blood lymphocytes of C. villosus was tested over a range of concentrations (280, 420, 560, 1120 µmol/L). Culture medium without glyphosate served as negative control, while medium containing mitomycin C served as positive control. Genetic damage was characterized in terms of the percentage of cells with chromosome aberrations (CA), the mean number of sister chromatid exchanges (SCE) per cell, and the modification of cell proliferation kinetics via the calculation of the replication index. Significant increases (p < 0.0001) were seen in the CA frequency and the mean number of SCEs per cell compared to negative controls at all the RU concentrations tested. Chromatid breaks, the only form of CA observed, under the 560 µmol/L RU conditions and in presence of mitomycin C were four to five times more common than at lower concentrations, while no viable cells were seen in the 1120 µmol/L treatment. The mean number of SCEs per cell was significantly higher under the 280 µmol/L RU conditions than the 420 or 560 µmol/L RU conditions; cells cultivated in the presence of MMC also showed significantly more SCEs. All the RU concentrations tested (except in the 1120 µmol/L RU treatment [no viable cells]) induced a significant reduction in the replication index (p < 0.0001). The present results confirm the genotoxic effects of RU on C. villosus lymphocytes in vitro, strongly suggesting that exposure to RU could induce DNA damage in C. villosus wildlife.

Chaetophractus villosus as a sentinel organism: Baseline values of mitotic index, chromosome aberrations and sister chromatid exchanges.

Sentinel species are useful tools for studying the deleterious effects of xenobiotics on wildlife. The large hairy armadillo (Chaetophractus villosus) is the most abundant and widely distributed mammal in Argentina. It is a long-lived, omnivorous, burrowing species, with fairly restricted home ranges. To evaluate the level of spontaneous genetic damage in this mammal, we determined the baseline values of several genotoxicity biomarkers. The study included 20 C. villosus adults of both sexes from eight pristine localities within its geographic distribution range. Genotoxicity analysis was performed on 72-h lymphocyte cultures, using mitomycin C as positive control. We obtained the baseline values of mitotic index (MI=10.52±0.30 metaphases/total cells, n=20), chromosome aberrations (CA=0.13±0.22, n=20), sister chromatid exchanges (SCE)=6.55±0.26, n=6) and replication index (RI=1.66, n=6). MI and CA did not show significant differences (P>0.05) among localities or between sexes. No significant differences in MI, CA, SCE, and RI (P>0.05) were found between values from the pristine localities and historical data. There were significant differences in CA, SCE, and RI (P<0.05) between lymphocyte cultures from pristine localities and those exposed to mitomycin C. We propose the large hairy armadillo as a sentinel organism for environmental biomonitoring of genotoxic chemicals due to its abundance, easy manipulation, well-known biology, the fact that it is usually exposed to different mixtures and concentrations of environmental contaminants, and the baseline values of genetic damage characterized by MI, CA, SCE and RI as biomarkers.

Native Joint Septic Arthritis: Epidemiology, Clinical Features, and Microbiological Causes in a New Zealand Population.

OBJECTIVE: To determine the epidemiology, clinical features, and microbiology of adult native joint septic arthritis in Canterbury, New Zealand, over a 5-year period in individuals with and without an underlying rheumatic disorder. METHODS: Patients with native joint septic arthritis were identified retrospectively and classified by Newman's criteria. The clinical characteristics were described and comparisons made between those with and without underlying rheumatic disease. RESULTS: Two hundred forty-eight cases of native joint septic arthritis (mean age 60, range 16-97 yrs) were identified with an overall incidence rate of 12.0/100,000/year (95% CI 10.6-13.6). Yearly incidence increased with age to a maximum of 73.4/100,000 in those > 90 years of age. Septic arthritis was iatrogenic in 16.9% of cases while 27% had an underlying inflammatory arthritis including gout (14.9%), calcium pyrophosphate disease (8.5%), and rheumatoid arthritis (4%). Few patients were taking immunosuppressant therapy, with just 1 taking a biological agent. Staphylococcus aureus was the most commonly identified organism. Those with underlying inflammatory arthritis were significantly older (73.6 yrs vs 55.6 yrs; p < 0.001), more likely to be female (55.2% vs 26.0%; p < 0.001), and to have septic polyarthritis (16.4% vs 4.4%; p = 0.002). The 30-day mortality was 2%, increasing to 6% at 90 days. CONCLUSION: The incidence of septic arthritis in Canterbury, New Zealand, is higher than in previous studies. Crystal arthropathy commonly coexisted with infection although autoimmune arthritis and immunosuppression was less of a factor than anticipated.

Imiquimod: a review.

BACKGROUND AND OBJECTIVE: Imiquimod (Aldara) is an immune response modifier used primarily to treat anogenital warts. Imiquimod induces cytokines and enhances cell-mediated cytolytic antiviral activity in vivo. It exhibits antiviral and antitumor effects; however, it does not exhibit direct antiviral effects in vitro. By inducing cytokines, such as interferon a, imiquimod stimulates both the innate immune response and the cellular arm of acquired immunity. Currently, imiquimod is approved for use in the treatment of external genital and perianal warts in adults. CONCLUSION: Beyond its established use, there are case reports and preliminary studies suggesting the effectiveness of imiquimod 5% cream in the treatment of nongenital human papillomavirus warts, molluscum contagiosum, actinic keratosis, basal cell carcinoma, squamous cell carcinoma, Bowen's disease, nongenital human papillomavirus infection, and vulvar intraepithelial neoplasia.

Nonpsoriatic uses of calcipotriol.

BACKGROUND: Calcipotriol is a synthetic vitamin D3 analog that binds to vitamin D receptors in epidermal cells. In vitro studies have shown that calcipotriol stimulates terminal cell differentiation and has antiproliferative effects. In vivo, calcipotriol has been shown to reduce the number of cycling epidermal cells. Calcipotriol also has less effect on calcium metabolism than calcitriol, which is the natural, bioactive, 1,25-dihydroxyvitamin D3. OBJECTIVE: These properties make calcipotriol an ideal candidate for the topical treatment of hyperproliferative skin disorders. While it has been approved for topical use in psoriasis, its potential for use in other dermatological disorders has not yet been fully investigated. CONCLUSION: This survey of the literature suggests that calcipotriol may show promise in the treatment of other conditions involving abnormal keratinization and hyperproliferation of epidermal cells. While some of these disorders are rare, and therefore difficult to study, further study into the nonpsoriatic uses of calcipotriol may be rewarding.