Genetic variability in G2 and F2 region between biological clones of human respiratory syncytial virus with or without host immune selection pressure

Human respiratory syncytial virus (HRSV) is an important respiratory pathogens among children between zero-five years old. Host immunity and viral genetic variability are important factors that can make vaccine production difficult. In this work, differences between biological clones of HRSV were detected in clinical samples in the absence and presence of serum collected from children in the convalescent phase of the illness and from their biological mothers. Viral clones were selected by plaque assay in the absence and presence of serum and nucleotide sequences of the G2 and F2 genes of HRSV biological clones were compared. One non-synonymous mutation was found in the F gene (Ile5Asn) in one clone of an HRSV-B sample and one non-synonymous mutation was found in the G gene (Ser291Pro) in four clones of the same HRSV-B sample. Only one of these clones was obtained after treatment with the child's serum. In addition, some synonymous mutations were determined in two clones of the HRSV-A samples. In conclusion, it is possible that minor sequences could be selected by host antibodies contributing to the HRSV evolutionary process, hampering the development of an effective vaccine, since we verify the same codon alteration in absence and presence of human sera in individual clones of BR-85 sample.

Changes in growth, essential oil yield and composition of geranium (Pelargonium graveolens L.) as affected by growing media.

BACKGROUND: Using proper growing medium is known to be an effective way to improve crop growth and yield. However, the effects of growing media on geranium essential oil have scarcely ever been examined in detail. In this research, the effects of different growing media (soil, sand, pumice, perlite and perlite + cocopeat) on growth, oil yield and composition of geranium were studied. RESULTS: Growth was significantly improved in soilless-grown plants compared with soil-grown plants. Oil yield of soilless-grown plants (except for pumice) was about threefold higher than that of soil-grown plants. The increase in oil yield was correlated with higher leaf dry weight (r² = 0.96), as oil content was not affected. The citronellol/geranium ratio of oil was clearly affected by growing media, ranging from 5:1 in soil culture to 3:1 in soilless culture. The latter is acceptable for perfumery. CONCLUSION: Compared with soil, soilless media could produce higher yields of high-quality geranium oil that fits market requirements. Growth, oil yield and composition of plants grown in sand (a cheap and abundant growing medium) were not significantly different from those of plants grown in perlite and perlite + cocopeat.

Social rank and inhalant drug use: the case of lança perfume use in São Paulo, Brazil.

BACKGROUND: Lanca perfume (chloroform/ether) is an inhalant used mainly by higher social class students in Brazil. In light of the social and epidemiological features of lanca use, supply, and distribution, this investigation tests hypotheses about the degree to which use of inhalant lanca might be occurring in clusters, consistent with social sharing and diffusion, and might show a direct association with social rank even within the relatively privileged social context of private schools in a large mega-city of Latin America. METHODS: Epidemiologic self-report survey data were from a large representative sample of urban post-primary private school students in São Paulo city, Brazil, in 2008. Newly incident lanca use was studied, first with estimates of clustering from the alternating logistic regressions (ALR) and then with conditional logistic regressions to probe into the hypothesized direct social rank association. RESULTS: ALR disclosed a clustering of newly incident lanca users within private school classrooms (pairwise odds ratio (PWOR)=2.1; 95% CI=1.3, 3.3; p=0.002) as well as clusters of recently active lanca use (PWOR=1.9; 95% CI=1.1, 3.3; p=0.02). Occurrence of lanca use within private school classrooms was directly associated with social rank (odds ratio (OR)=0.2; 95% CI=0.1, 0.8; p=0.03 in the contrast of lowest socio-economic status (SES) versus highest SES strata within classrooms). Thereafter, study of other drugs disclosed similar patterns. CONCLUSIONS: The clustering estimates are consistent with concepts of person-to-person sharing of lanca within private school classrooms as well as other dynamic processes that might promote lanca clusters in this context. An observed direct association with social rank is not specific to lanca use. Direct SES estimates across a broad profile of drug compounds suggests causal processes over and above the more specific initially hypothesized social rank gradients in the lanca diffusion process. A novel facet of the evidence is greater occurrence of drug use among the higher social rank private school students, which should be of interest in the social science community.

Flower scents from the Pacific.

For a long time, exotic scents from the islands of the South Pacific have universally been appreciated. Most frequently, fragrant flowers (e.g., frangipani, jasmine sambac, tiaré, pua kenikeni) are used locally for ornamental purposes such as flower garlands (leis). Despite their powerful and delightful fragrance, very few of these flowers have been commercially employed in this part of the world for perfume manufacturing. Creative perfumers are nevertheless strongly interested to better understand these fragrances and to use them, either genuine or artificially reconstituted. Analytical results on the fragrance of these flowers are reported, together with some economical considerations.