In vivo antitumor activity of hydrosoluble derivatives of 7-hydroxycholesterols

Sodium bis-hemisuccinates of 7 beta- and 7 alpha-hydroxycholesterols are moderately water-soluble. They have been tested intraperitoneally against the murine Krebs-II carcinoma, grown as an ascitic tumour, and their action has been compared with that of usual chemotherapeutic drugs, cyclophosphamide, 5-fluoro-uracil, and methotrexate. The hydroxycholesterol derivatives show a faster and stronger activity (life prolongation), and lead to the complete disappearance of the tumour in about 1/3 of the cases, even with one single injection. Similar results have been obtained (on fewer cases) with two other experimental ascitic tumours, the S-180 sarcoma and the ZHC hepatoma. The mechanism of action is not known; it appears to be very different from that of the usual anti-cancer chemotherapeutic agents.     

Genetic relationships among Vietnamese local pigs investigated using genome‐wide SNP markers

Vietnam is one of the most important countries for pig domestication, and a total of 26 local breeds have been reported. In the present study, genetic relationships among the various pig breeds were investigated using 90 samples collected from local pigs (15 breeds) in 15 distantly separated, distinct areas of the country and six samples from Landrace pigs in Hanoi as an out‐group of a common Western breed. All samples were genotyped using the Illumina Porcine SNP60 v2 Genotyping BeadChip. We used 15 160–15 217 SNPs that showed a high degree of polymorphism in the Vietnamese breeds for identifying genetic relationships among the Vietnamese breeds. Principal components analysis showed that most pigs indigenous to Vietnam formed clusters correlated with their original geographic locations. Some Vietnamese breeds formed a cluster that was genetically related to the Western breed Landrace, suggesting the possibility of crossbreeding. These findings will be useful for the conservation and management of Vietnamese local pig breeds.     

Direct shoot formation and plant regeneration from cotyledon explants of rapid-cycling Brassica rapa

Summary An in vitro culture system for direct shoot regeneration from cotyledon explants of rapid-cycling Brassica rapa was developed. Cotyledons from 3-d-old seedlings, when cultured on Murashige and Skoog (MS) medium supplemented with 20 μM N⁶-benzyladenine (BA) and 2 μM α-naphthaleneacetic acid (NAA), regenerated shoots directly at a frequency of 20%. The addition of 2 μM aminoethoxyvinylglycine (AVG) to this medium increased shoot regeneration to 33%, but silver nitrate drastically inhibited shoot regeneration. Shoot regeneration occurred directly, at the petiolar cut ends of cotyledonary explants, between 10 to 17 d in culture. The highest percentage of regeneration (33%) was obtained from 3-d-old seedlings. NAA was the most effective auxin for root induction and development, with 49% of shoots producing roots after 2 wk on medium containing 1.0 μM NAA. Regenerated plantlets were grown to maturity in pots containing peat moss and vermiculite (1:1). These plants were morphologically normal and fertile. With this protocol, over 100 independently derived, flowering R₀ plants were obtained from 40 regenerating cotyledonary explants within 40 d after culture initiation.     

A Novel Gene Controlling the Timing of Courtship Initiation in Drosophila melanogaster

Over the past 35 years, developmental geneticists have made impressive progress toward an understanding of how genes specify morphology and function, particularly as they relate to the specification of each physical component of an organism. In the last 20 years, male courtship behavior in Drosophila melanogaster has emerged as a robust model system for the study of genetic specification of behavior. Courtship behavior is both complex and innate, and a single gene, fruitless (fru), is both necessary and sufficient for all aspects of the courtship ritual. Typically, loss of male-specific Fruitless protein function results in male flies that perform the courtship ritual incorrectly, slowly, or not at all. Here we describe a novel requirement for fru: we have identified a group of cells in which male Fru proteins are required to reduce the speed of courtship initiation. In addition, we have identified a gene, Trapped in endoderm 1 (Tre1), which is required in these cells for normal courtship and mating behavior. Tre1 encodes a G-protein-coupled receptor required for establishment of cell polarity and cell migration and has previously not been shown to be involved in courtship behavior. We describe the results of feminization of the Tre1-expressing neurons, as well as the effects on courtship behavior of mutation of Tre1. In addition, we show that Tre1 is expressed in a sexually dimorphic pattern in the central and peripheral nervous systems and investigate the role of the Tre1 cells in mate identification.     

Identifying outlier loci in admixed and in continuous populations using ancestral population differentiation statistics

Finding genetic signatures of local adaptation is of great interest for many population genetic studies. Common approaches to sorting selective loci from their genomic background focus on the extreme values of the fixation index, F_ST, across loci. However, the computation of the fixation index becomes challenging when the population is genetically continuous, when predefining subpopulations is a difficult task, and in the presence of admixed individuals in the sample. In this study, we present a new method to identify loci under selection based on an extension of the F_ST statistic to samples with admixed individuals. In our approach, F_ST values are computed from the ancestry coefficients obtained with ancestry estimation programs. More specifically, we used factor models to estimate F_ST, and we compared our neutrality tests with those derived from a principal component analysis approach. The performances of the tests were illustrated using simulated data and by re‐analysing genomic data from European lines of the plant species Arabidopsis thaliana and human genomic data from the population reference sample, POPRES.     

Changes in P3b Latency and Amplitude Reflect Expertise Acquisition in a Football Visuomotor Learning Task

Learning is not a unitary phenomenon. Rather, learning progresses through stages, with the stages reflecting different challenges that require the support of specific cognitive processes that reflect the functions of different brain networks. A theory of general learning proposes that learning can be divided into early and late stages controlled by corticolimbic networks located in frontal and posterior brain regions, respectively. Recent human studies using dense-array EEG (dEEG) support these results by showing progressive increases in P3b amplitude (an Event Related Potential with estimated sources in posterior cingulate cortex and hippocampus) as participants acquire a new visuomotor skill. In the present study, the P3b was used to track the learning and performance of participants as they identify defensive football formations and make an appropriate response. Participants acquired the task over three days, and P3b latency and amplitude significantly changed when participants learned the task. As participants demonstrated further proficiency with extensive training, amplitude and latency changes in the P3b continued to closely mirror performance improvements. Source localization results across all days suggest that an important source generator of the P3b is located in the posterior cingulate cortex. Results from the study support prior findings and further suggest that the careful analysis of covert learning mechanisms and their underlying electrical signatures are a robust index of task competency.     

Laser-raman spectra of d-glucose and sucrose in aqueous solution

Laser-Raman spectra of d-glucose in water at various concentrations were recorded below 1700 cm^?1. Assignments of the frequencies of d-glucose were proposed, based on earlier work on the vibrational spectra of this sugar, and determination by other techniques of the anomeric composition of aqueous solutions of d-glucose. The proportions of the anomers found from the ratio of the Raman intensities for the same models of vibrations were similar to those found by other techniques. Assignments of the frequencies for sucrose were proposed, in the light of previous results on d-glucose and d-fructose, and the effect, on their Raman spectra, of the condensation of these two monosaccharides was pointed out.     

Cytotoxic components of Zingiber zerumbet,Curcuma zedoaria and C. domestica

One new and five known compounds, which all showed cytotoxic activity, were isolated from the rhizomes of Zingiber zerumbet. The new compound was 3″,4″-O-diacetylafzelin. The known compounds were zerumbone, zerumbone epoxide, diferuloylmethane, feruloyl-p-coumaroylmethane and di-p-coumaroylmethane. Several substituted cinnamoylmethanes were synthesized and tested for cytotoxic properties. Among these were tricinnamoylmethane and triferuloylmethane. The structures were elucidated mainly by spectroscopic methods and ¹³C NMR data are given.     

The DM-20 proteolipid is a major protein of the brain. It is synthetized in the fetus earlier than the major myelin proteolipid (PLP)

By studying highly purified CNS proteolipids, we have shown that DM-20 proteolipid, which was considered, until now, to be a minor brain proteolipid is, in fact, almost as abundant as the Major Myelin Proteolipid known also as Proteolipid Protein (PLP). DM-20 proteolipid is even the major brain proteolipid in young foetuses. It is only during myelinisation that the "Proteolipid Protein" increases rapidly and becomes equivalent in weight to DM-20 proteolipid. This study raises the question of the particular function of DM-20 proteolipid.