Influence of the extraction mode on the yield of some furanocoumarins from Pastinaca sativa fruits

Analysis of plant material is an important task in chemotaxonomical investigations, in search of plants with pharmacological activity or in standardisation of plant drugs. The choice of optimal conditions for the analysis of plant material and effect of extraction method on the yield of furanocoumarins from Pastinaca sativa fruits were examined. The following extraction methods were used in experiments: exhaustive extraction in Soxhlet apparatus, ultrasonification (USAE) at 25 and 60 degrees C, microwave-assisted solvent extraction in open and closed system (MASE) and accelerated solvent extraction (ASE). In most cases, the yield of furanocoumarins was highest by use of ASE method as well as by ultrasonification at 60 degrees C.     

Fluorescence methods (VistaCam iX proof and DIAGNODent pen) for the detection of occlusal carious lesions in teeth recovered from archaeological context

Diagnosis of occlusal enamel caries in archaeologically derived collections remains a controversial problem because the accumulation of contaminants in fissures can interfere with diagnosis. Certain novel light‐induced fluorescence methods, such as the DIAGNODent pen 2190 (DD) and VistaCam iX Proof (VC), have been used to detect dental caries in clinical settings. In this study, the abilities of DD and VC to detect initial enamel caries in archaeologically derived material is determined and compared with those of other methods (visual inspection, X‐ray, histology, and micro‐CT). Dental material encompassing the remains of 58 individuals, including a total of 380 teeth from each of three historical periods: modern Islamic (AD 1850–1950), Islamic (AD 600–1200) and late Roman (AD 200–400), obtained from two archaeological sites (Terqa and Tell Masaikh) located in the Middle Euphrates valley (Syria), were analyzed. VC was found to have excellent sensitivity (98), while DD obtained lower sensitivity (76) in detecting dental caries in its early stages. The results obtained by VC and micro‐CT, considered the most reliable imaging technique, were not statistically significant (P = 0.3068). By contrast, results obtained by DD and micro‐CT results, and DD and VC results were statistically significant (P < 0.0001, P = 0.0015, respectively). However the presence of dirt, stain, calculus, and plaque in the pits and fissures of the occlusal surface compromise correct diagnosis of caries by VC and DD. Consequently, for teeth recovered from archaeological contexts where staining, calculus and plaque are present, the best solution remains micro‐CT. Am J Phys Anthropol 154:525–534, 2014. © 2014 Wiley Periodicals, Inc.     

Cytology and fertility of viable hybrids of Nicotiana tabacum L. cv. TB-566 with N. alata Link et Otto

A vigorous hybrid (N. tabacum cv. TB-566 tetra x N. alata) x N. alata was obtained by backcrossing a partly viable sesquidiploid hybrid N. tabacum cv. TB-566 tetra x N. alata to N. alata. The hybrid was a 35-chromosome near-amphihaploid with a pair of N. alata chromosomes in disomic condition. It was completely self- and cross-sterile and formed from 7 to 8 bivalents in pollen mother cells. By using stem pith culture, polyploidized regenerants were obtained from the 35-chromosome hybrid with somatic chromosome numbers from 65 to 70. These regenerants showed fairly regular meiosis with the number of bivalents in pollen mother cells ranging from 27.3 to 30.4. Irregularities in meiosis included a high number of univalents, aberrant tetrads, and a high frequency of micronuclei. The percentage of acetocarmine-stainable pollen ranged from 22.1 to 78.4. A 66-chromosome regenerant showed fairly regular meiosis and was self-fertile but could not be backcrossed to N. tabacum. This barrier seems to be caused by genic imbalance rather than irregularities of meiotic divisions. Hence transfer programs based on the introgression of entire linkage groups (sexual and somatic hybridization) seem to be of little use in the case of that species.     

The optimality of the standard genetic code assessed by an eight-objective evolutionary algorithm

Background

The standard genetic code (SGC) is a unique set of rules which assign amino acids to codons. Similar amino acids tend to have similar codons indicating that the code evolved to minimize the costs of amino acid replacements in proteins, caused by mutations or translational errors. However, if such optimization in fact occurred, many different properties of amino acids must have been taken into account during the code evolution. Therefore, this problem can be reformulated as a multi-objective optimization task, in which the selection constraints are represented by measures based on various amino acid properties.

Results

To study the optimality of the SGC we applied a multi-objective evolutionary algorithm and we used the representatives of eight clusters, which grouped over 500 indices describing various physicochemical properties of amino acids. Thanks to that we avoided an arbitrary choice of amino acid features as optimization criteria. As a consequence, we were able to conduct a more general study on the properties of the SGC than the ones presented so far in other papers on this topic. We considered two models of the genetic code, one preserving the characteristic codon blocks structure of the SGC and the other without this restriction. The results revealed that the SGC could be significantly improved in terms of error minimization, hereby it is not fully optimized. Its structure differs significantly from the structure of the codes optimized to minimize the costs of amino acid replacements. On the other hand, using newly defined quality measures that placed the SGC in the global space of theoretical genetic codes, we showed that the SGC is definitely closer to the codes that minimize the costs of amino acids replacements than those maximizing them.

Conclusions

The standard genetic code represents most likely only partially optimized systems, which emerged under the influence of many different factors. Our findings can be useful to researchers involved in modifying the genetic code of the living organisms and designing artificial ones.

     

Assessment of potential application of binary mixtures of 2,4-d with novel aminophosphonates

A series of new aminoalkane- and aminofluorenephosphonates was synthesized for agrochemical application. The particular compounds had different alkyl substituents at the carbon, nitrogen and phosphorus atoms. Their pesticidal activity was checked by applying various experimental methods. These included the measurements of compounds' potency: to inhibit growth of cucumber and germination of white mustard seeds, to influence on the membrane potential of algae and to damage human erythrocyte membranes resulting in hemolysis. All the aminophosphonates were also used in equimolar binary mixtures with the well-known herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), to check, if using such mixtures, the biological efficiencies found for particular compounds could be enhanced due to interactions between aminophosphonates and 2,4-D. The results demonstrated, that depending on the structural features of the compounds, the final effects differed from antagonistic, through additive to the most promising synergistic ones. However, the type of interaction between 2,4-D and the compounds studied found in different experiments was somewhat different. In order to estimate those effects various statistical methods were used (toxic unit method, isobole method).     

Evidence for an increased distribution range of Dermacentor reticulatus in south-west Poland

The expansion of Dermacentor reticulatus to new geographical areas has been observed in several countries in Europe, including Poland and it’s neighbors. In 2011 and 2012, a total of 148 host-seeking D. reticulatus ticks were collected after flagging the vegetation in Lower Silesia, south-western Poland. Tick monitoring was conducted in mixed and deciduous forest, on meadows, in river valleys and ecotones between forested and grassy areas. The ornate dog ticks were found in 10 out of 33 sites located in five districts: Legnica, Wroclaw, ?roda ?l?ska, Lubin and Boleslawiec County. All sites where D. reticulatus ticks were found are located to the south-west of the Odra River. The greatest distance between these disconnected localities was approximately 90 km. It seems that at present the southern boundary of the range is Wroclaw district. This study indicates that D. reticulatus can be ranked as a typical element of the fauna in Lower Silesia in southwestern Poland.     

Long-term effects of dietary glycemic index on adiposity, energy metabolism, and physical activity in mice

A high-glycemic index (GI) diet has been shown to increase adiposity in rodents; however, the long-term metabolic effects of a low- and high-GI diet have not been examined. In this study, a total of 48 male 129SvPas mice were fed diets high in either rapidly absorbed carbohydrate (RAC; high GI) or slowly absorbed carbohydrate (SAC; low GI) for up to 40 wk. Diets were controlled for macronutrient and micronutrient content, differing only in starch type. Body composition and insulin sensitivity were measured longitudinally by DEXA scan and oral glucose tolerance test, respectively. Food intake, respiratory quotient, physical activity, and energy expenditure were assessed using metabolic cages. Despite having similar mean body weights, mice fed the RAC diet had 40% greater body fat by the end of the study and a mean 2.2-fold greater insulin resistance compared with mice fed the SAC diet. Respiratory quotient was higher in the RAC group, indicating comparatively less fat oxidation. Although no differences in energy expenditure were observed throughout the study, total physical activity was 45% higher for the SAC-fed mice after 38 wk of feeding. We conclude that, in this animal model, 1) the effect of GI on body composition is mediated by changes in substrate oxidation, not energy intake; 2) a high-GI diet causes insulin resistance; and 3) dietary composition can affect physical activity level.     

A survey of metronidazole and vancomycin resistance in strains of Clostridium difficile isolated in Warsaw, Poland

The drug of choice used to treat Clostridium difficile-associated diarroea (CDAD) are metronidazole and vancomycin. Information about emergence of antimicrobial resistance among C. difficile strains to metronidazole and intermediate resistance to vancomycin in some countries are alarming. This study was performed to determine the susceptibility to metronidazole and vancomycin of 193 C. difficile strains isolated in our diagnostic laboratory between year 1998 and 2003 from patients adults and children suffering from CDAD. Among these strains, 142 produced toxin A and B (TcdA(+)TcdB(+)), 43 only B (TcdA(-)TcdB(+)) and 8 were nontoxigenic. We have not observed any differences in susceptibility to metronidazole and vancomycin between all C. difficile strains under investigation (toxinogenic and non-toxinogenic). Resistance to metronidazole and vancomycin was not observed.