Synthesis of Dolichols in Candida albicans Is Co-Regulated with Elongation of Fatty Acids

Protein glycosylation requires dolichyl phosphate as a carbohydrate carrier. Dolichols are α-saturated polyprenols, and their saturation in S. cerevisiae is catalyzed by polyprenyl reductase Dfg10 together with some other unknown enzymes. The aim of this study was to identify such enzymes in Candida. The Dfg10 polyprenyl reductase from S. cerevisiae comprises a C-terminal 3-oxo-5-alpha-steroid 4-dehydrogenase domain. Alignment analysis revealed such a domain in two ORFs (orf19.209 and orf19.3293) from C. albicans, which were similar, respectively, to Dfg10 polyprenyl reductase and Tsc13 enoyl-transferase from S. cerevisiae. Deletion of orf19.209 in Candida impaired saturation of polyprenols. The Tsc13 homologue turned out not to be capable of saturating polyprenols, but limiting its expression reduce the cellular level of dolichols and polyprenols. This reduction was not due to a decreased expression of genes encoding cis-prenyltransferases from the dolichol branch but to a lower expression of genes encoding enzymes of the early stages of the mevalonate pathway. Despite the resulting lower consumption of acetyl-CoA, the sole precursor of the mevalonate pathway, it was not redirected towards fatty acid synthesis or elongation. Lowering the expression of TSC13 decreased the expression of the ACC1 gene encoding acetyl-CoA carboxylase, the key regulatory enzyme of fatty acid synthesis and elongation.     

Changes in Polar Metabolites Content during Natural and Methyl-Jasmonate-Promoted Senescence of Ginkgo biloba Leaves

The present study clarified changes in the contents of polar metabolites (amino acids, organic acids, saccharides, cyclitols, and phosphoric acid) in leaf senescence in Ginkgo biloba with or without the application of methyl jasmonate (JA-Me) in comparison with those in naturally senescent leaf blades and petioles. The contents of most amino acids and citric and malic acids were significantly higher in abaxially, and that of myo-inositol was lower in abaxially JA-Me-treated leaves than in adaxially JA-Me-treated and naturally senescent leaves. The levels of succinic and fumaric acids in leaves treated adaxially substantially high, but not in naturally senescent leaves. In contrast, sucrose, glucose, and fructose contents were much lower in leaf blades and petioles treated abaxially with JA-Me than those treated adaxially. The levels of these saccharides were also lower compared with those in naturally senescent leaves. Shikimic acid and quinic acid were present at high levels in leaf blades and petioles of G. biloba. In leaves naturally senescent, their levels were higher compared to green leaves. The shikimic acid content was also higher in the organs of naturally yellow leaves than in those treated with JA-Me. These results strongly suggest that JA-Me applied abaxially significantly enhanced processes of primary metabolism during senescence of G. biloba compared with those applied adaxially. The changes in polar metabolites in relation to natural senescence were also discussed.     

The Effectiveness of the Methane Drainage of the Rock-Mass with a Parallel Ventilation Heading during Longwall Mining

Methane drainage is used in Polish coal mines in order to reduce mine methane emission as well as to keep methane concentration in mine workings at safe levels. This article describes the method of methane drainage used in longwall 2 in seam 506. In Poland, coal seams are frequently mined in difficult conditions of very high methane hazard. Under such situations, methane is drained by means of parallel ventilation headings. This paper shows the influence of a specific ventilation system on the drainage efficiency at longwall 2 in seam 506. At this longwall, measurements of methane emission and the efficiency of drained methane were conducted. They consisted in gauging methane concentration, air velocity, absolute air pressure and the amount of methane removed via a drainage system. Experimental data were used to estimate the variations in absolute methane-bearing capacity, ventilation air methane and most importantly, to gauge the efficiency of methane drainage.     

Experiences from the implementation of a urine separation system: Goals,planning, reality

Over the last decade it has been ever increasing interest in developing alternative sanitary systems, which would be more sustainable than a conventional one is. In Sweden urine separation has been considered a promising approach towards increasing recycling of wastewater nutrients. Full scale trials are carried out and examined. This paper presents a study on implementation of urine separation system in urban environment. Technical and non-technical aspects of system performance are evaluated; system's interference with existing infrastructure is examined. Benefits and losses connected to urine separation system are analysed not only from environmental perspective but also system's owner point of view.     

Thermal stripping of supramolecular structures: C60 nanorods

The investigated ionic C60 derivative self-assembles into nanorods. When the functional side groups are removed by heating the nanorods to 623 K, they retain their shape. Utilization of lithographic markers allows the study of identical nanostructures before and after heat treatment by dynamic mode atomic force microscopy. Various independent techniques, including Raman spectroscopy and mass spectroscopy demonstrate that the shape-preserving mechanism is a thermal-stripping process, stabilizing the original supramolecular morphology. The latter implies two coherent sub-processes: detachment of the side groups and oligopolymerization running in parallel, eventually yielding rod-shaped C60 polymers. Synthesizing fullerenic polymers in this way can lead to several applications.     

Effect of gamma-radiation and microwave heating of wheat grain on some starch properties in irradiated grain as well as in grain of the next generation crops

Grains of the Polish winter wheat variety Begra were subjected to gamma-radiation (grain harvested in 1996) within the dose range of 0.05-10 kGy and microwave heating (grain harvested in 1997) from 28 degrees C to 98 degrees C. Later the grains were divided into two parts, the first was used for direct analyses after treatment. The second part was sown on the experimental fields. The obtained crop was described as the first generation and divided into two parts. One part was destined to determination of starch properties and the second part was sown in order to obtain the second generation crop. The same pattern was conducted in order to achieve the third generation crop. gamma-Irradiation directly applied on the wheat grain reduced statistically significant falling number values and gelatinisation enthalpy (deltaH) of the grain treated by 5 and 10 kGy. Calculated linear regression correlation coefficient between the falling number values and the gelatinisation enthalpy was equal to 0.94 (p < or = 0.001) and showed that these two starch characteristics are well correlated in the case of directly irradiated wheat grain. The falling number values, peak temperatures (Tp) and gelatinisation enthalpy (deltaH), in three generations of wheat grain crop studied, did not show any statistically significant differences as a result of indirect effect of gamma-irradiation. Microwave direct heating of wheat grain to 98 degrees C caused a statistically significant increase in the falling number value and decrease in starch gelatinisation power expressed by the enthalpy of gelatinisation (deltaH). The statistically significant changes in the falling number values, slight changes in the peak temperatures (Tp) and enthalpy of gelatinisation (deltaH) were found in all three generation crops as an indirect effect of microwave heating.     

Determination of Terpene Profiles in Potential Superfruits

The aim of this work was to characterize and compare the profiles of volatile terpenes in four potential superfruits. These profiles were determined using headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography linked to time-of-flight mass spectrometry. The proposed technique allowed the separation and identification of 79 terpenes present in cape gooseberry, crabapple, cherry silver berry, and scarlet hawthorn. The preliminary compound identification was based on the analysis of deconvoluted mass spectra and a comparison of the calculated linear retention indices with their values reported in the scientific literature. The compound identification was performed using the available standards. Also, a semi-quantitative total ion chromatogram-based analysis was performed. The richest terpene profile was identified in cape gooseberry (62 terpenes), where the terpene fraction constituted about 14% of total volatile fraction.     

3-MCPD: A Worldwide Problem of Food Chemistry

3-Monochloropropane-1,2-diol (3-MCPD) is a heat-induced food contaminant that has been widely investigated for decades. This paper presents an overview of current knowledge about 3-MCPD, including its formation routes, occurrence in various foodstuffs, analytical approach, toxicological aspects, and future research perspectives. So far, 3-MCPD was determined in its free and bound form in thermally treated foods, edible oils and fats, and infant foods including human breast milk. Contaminants in infant foods and human breast milk were highlighted in this paper as a serious problem as they can pose a potential hazard for infants. The analytical approach of 3-MCPD determination has been modified for over a decade. Nowadays, the method based on determining the derivative of this compound by using gas chromatography and mass spectrometry is widely used. However, there is still a big need for developing new methods that would produce repeatable results. Some of the toxicologic aspects associated with 3-MCPD still remain unknown. A number of studies on the carcinogenicity and genotoxicity of 3-MCPD were carried out on rodents; however, no clinical studies on humans have been reported so far. Moreover, both detrimental effect on kidneys and antifertility activity have been widely reported. The knowledge of 3-MCPD absorption into body fluids and tissues and its metabolic pathways is based on sometimes conflicting data derived from different studies. In conclusion, although a lot of research has been carried out on 3-MCPD, there is still a need for further research in this area.     

Accumulation of Anthocyanins in Detached Leaves of Kalanchoë blossfeldiana: Relevance to the Effect of Methyl Jasmonate on This Process

Accumulation of anthocyanins in detached leaves and in excised stems of Kalanchoë blossfeldiana kept under natural light conditions in the presence or absence of methyl jasmonate (JA-Me) was investigated. When the abaxial surface of detached leaves was held lower than the adaxial surface (the normal or natural position) under natural light conditions, anthocyanins were not accumulated on the abaxial side of the leaves. In contrast, when the adaxial surface of detached leaves was held lower than the abaxial surface (inverted position), anthocyanins were highly accumulated on the abaxial side of the leaves. These phenomena were independent of the growth stage of K. blossfeldiana as well as photoperiod. Application of JA-Me in lanolin paste significantly inhibited anthocyanin accumulation induced on the abaxial side of detached leaves held in an inverted position in a dose-dependent manner. Anthocyanin accumulation in the excised stem in response to natural light was also significantly inhibited by JA-Me in lanolin paste. Possible mechanisms of anthocyanin accumulation on the abaxial side of detached K. blossfeldiana leaves held in an inverted position under natural light conditions and the inhibitory effect of JA-Me on this process are described. The accompanying changes in the content of primary metabolites and histological analyses were also described.     

Additive Interactions between Betulinic Acid and Two Taxanes in In Vitro Tests against Four Human Malignant Melanoma Cell Lines

The incidence of melanoma is steadily increasing worldwide. Melanoma is the most lethal skin cancer, and new therapeutic methods are being sought. Our research aimed to investigate the cytotoxic and antiproliferative effects of betulinic acid in vitro, used alone and in combination with taxanes (paclitaxel, docetaxel) in four melanoma cell lines. Isobolographic analysis allowed us to assess the interactions between these compounds. Betulinic acid had no cytotoxic effect on normal human keratinocyte HaCaT cells; the amount of LDH released by them was significantly lower compared to melanoma cell lines. The present study shows that betulinic acid significantly inhibits the growth of melanoma cell lines in vitro. The IC50 values of betulinic acid ranged from 2.21 µM to 15.94 µM against the four melanoma lines. Co-treatment of betulinic acid with paclitaxel or docetaxel generated desirable drug–drug interactions, such as an additive and additive with a tendency to synergy interactions.