Affinity chromatography of embryonic inducing factors on heparin-Sepharose

Mesoderm-inducing factors were extracted from chicken embryos and partially purified by chromatography on DEAE-cellulose. The DEAE-cellulose eluate was applied to heparin-Sepharose. Most of the proteins are not bound to heparin. The adsorbed proteins were eluted with a linear NaCl gradient. In totipotent gastrula ectoderm of amphibians the eluted proteins induce the differentiation of muscle and notochord as well as of large masses of renal tubules and blood cells. A possible relationship to fibroblast growth factors and angiogenesis factor is discussed.     

Photoprotective effect of vitamins A and E on polyamine and oxygenated free radical metabolism in hairless mouse epidermis

The purpose of this study was to confirm the photoprotective effect on skin of vitamins A and E, due to inhibition of polyamine synthesis and production of free radicals. These variables were measured in the lumbar epidermis of the female hairless mouse subjected to UVA + B irradiation. Polyamines were assayed in epidermal homogenate by HPLC, and production of oxygenated free radicals was determined by spectrofluorometric assay of malonyl dialdehyde. It was determined that butyl-hydroxy-toluene and vitamin E inhibited production of free radicals (56% and 60%, respectively) and caused a significant reduction in polyamine biosynthesis (P less than 0.01), whereas the inhibitory effect of malonyl dialdehyde induced by vitamin A (30%) had no associated effect on polyamine metabolism.     

In situ adsorption for enhanced alkaloid production byCatharanthus roseus

Summary A significant fraction (10–40%) of the indole alkaloids produced byCatharanthus roseus was observed to be secreted into the medium. When a neutral polymeric resin, known to adsorb these alkaloids, was added to the cultivation medium, the accumulation of total indole alkaloids and the specific alkaloids, ajmalicine and serpentine were stimulated. Sorbent addition was also observed to result in increased ratios of ajmalicine to serpentine, which suggests the potential of using in situ adsorption to direct metabolism toward a specific product or intermediate within a given pathway.     

The Association between Regional Environmental Factors and Road Trauma Rates: A Geospatial Analysis of 10 Years of Road Traffic Crashes in British Columbia,Canada

BackgroundBritish Columbia, Canada is a geographically large jurisdiction with varied environmental and socio-cultural contexts. This cross-sectional study examined variation in motor vehicle crash rates across 100 police patrols to investigate the association of crashes with key explanatory factors.MethodsEleven crash outcomes (total crashes, injury crashes, fatal crashes, speed related fatal crashes, total fatalities, single-vehicle night-time crashes, rear-end collisions, and collisions involving heavy vehicles, pedestrians, cyclists, or motorcyclists) were identified from police collision reports and insurance claims and mapped to police patrols. Six potential explanatory factors (intensity of traffic law enforcement, speed limits, climate, remoteness, socio-economic factors, and alcohol consumption) were also mapped to police patrols. We then studied the association between crashes and explanatory factors using negative binomial models with crash count per patrol as the response variable and explanatory factors as covariates.ResultsBetween 2003 and 2012 there were 1,434,239 insurance claim collisions, 386,326 police reported crashes, and 3,404 fatal crashes. Across police patrols, there was marked variation in per capita crash rate and in potential explanatory factors. Several factors were associated with crash rates. Percent roads with speed limits ≤ 60 km/hr was positively associated with total crashes, injury crashes, rear end collisions, and collisions involving pedestrians, cyclists, and heavy vehicles; and negatively associated with single vehicle night-time crashes, fatal crashes, fatal speeding crashes, and total fatalities. Higher winter temperature was associated with lower rates of overall collisions, single vehicle night-time collisions, collisions involving heavy vehicles, and total fatalities. Lower socio-economic status was associated with higher rates of injury collisions, pedestrian collisions, fatal speeding collisions, and fatal collisions. Regions with dedicated traffic officers had fewer fatal crashes and fewer fatal speed related crashes but more rear end crashes and more crashes involving cyclists or pedestrians. The number of traffic citations per 1000 drivers was positively associated with total crashes, fatal crashes, total fatalities, fatal speeding crashes, injury crashes, single vehicle night-time crashes, and heavy vehicle crashes. Possible explanations for these associations are discussed.ConclusionsThere is wide variation in per capita rates of motor vehicle crashes across BC police patrols. Some variation is explained by factors such as climate, road type, remoteness, socioeconomic variables, and enforcement intensity. The ability of explanatory factors to predict crash rates would be improved if considered with local traffic volume by all travel modes.     

Long-term study (1974-1998) of seasonal changes in the phytoplankton in Lake Geneva: a multi-table approach

The monitoring of Lake Geneva began after one decade of eutrophicationand has provided a uniform set of phytoplankton data. This studyaimed to define the mean annual pattern of the seasonal successionsof phytoplankton species, and to determine whether inter-annualdistortions in this seasonal structure occur. We analysed the25 annual patterns using the STATIS multi-table method. Thephytoplankton successions in the first part of the year fittedwell with the pattern predicted by the Plankton Ecology Group(PEG) model. But the temporal evolution in the summer phytoplanktoncommunity differed from the PEG model, and was subject to between-yearsdifferences. We identified three homogeneous periods for theannual patterns: 1974–1985, 1986–1991 (except 1988)and 1992–1996 (including 1988). During the first period,phytoplankton succession followed the reference annual pattern,the typical autumnal community was missing during the secondperiod, and this autumn community developed earlier during thethird period. This study reflects the good ability of the phytoplanktoncommunity of Lake Geneva to resist both inter-annual fluctuationsand brutal shifts in the annual functioning of the system. Webelieve these shifts resulted from a gradual change in environmentalparameters, including the deepening of the phosphorus-depletedlayer and a change in its timing as a result of the long-termmeteorological changes.     

Towards a modular synthesis of well-defined chitooligosaccharides: synthesis of the four chitodisaccharides

The total chemical synthesis of the four well-defined chitodisaccharides is described using N-trichloroacetyl (TCA) and N-benzyloxycarbonyl (Z) as C-2 protecting groups for acetamido and free amino groups, respectively. The synthesis is carried out according to a strategy that paves way to the elaboration of various homo- and hetero-chitooligosaccharides, with perfect control of the number and the position of GlcN and GlcNAc units along the oligomer chain.     

Genetic variation at the porcine MYF-5 gene locus. Lack of association with meat production traits

The number of muscle fibers at birth appears to determine the maximal lean meat growth capacity in pigs and in cattle. Development of muscle fibers is regulated by the MyoD gene family consisting of MyoD1, myf-5, myf-6, and myogenin. Myf-5 is expressed in proliferating myoblasts. Here we report the genomic sequence of the porcine myf-5 gene with three microsatellites and two RFLPs located close to the coding sequences. Two of the microsatellites are located in the promoter region. The allelic distribution differs between breeds and selection lines. In two GY selection lines, 1216 pigs of two-generation families were genotyped for the HinfI RFLP, which was segregating in the GY breed. The other polymorphic loci are physically linked to this RFLP locus, and therefore the results can be extrapolated to these loci. Statistical analysis revealed no association with birth weight, growth rate, weight at slaughter age, carcass meat weight, and backfat thickness. Thus, in this study myf-5 did not explain genetic variation in meat (muscle) development in pigs. Received: 9 July 1998 / Accepted: 22 September 1998