Fructan and its relationship to abiotic stress tolerance in plants

Numerous studies have been published that attempted to correlate fructan concentrations with freezing and drought tolerance. Studies investigating the effect of fructan on liposomes indicated that a direct interaction between membranes and fructan was possible. This new area of research began to move fructan and its association with stress beyond mere correlation by confirming that fructan has the capacity to stabilize membranes during drying by inserting at least part of the polysaccharide into the lipid headgroup region of the membrane. This helps prevent leakage when water is removed from the system either during freezing or drought. When plants were transformed with the ability to synthesize fructan, a concomitant increase in drought and/or freezing tolerance was confirmed. These experiments indicate that besides an indirect effect of supplying tissues with hexose sugars, fructan has a direct protective effect that can be demonstrated by both model systems and genetic transformation

Degradation of haloaromatic compounds

An ever increasing number of halogenated organic compounds has been produced by industry in the last few decades. These compounds are employed as biocides, for synthetic polymers, as solvents, and as synthetic intermediates. Production figures are often incomplete, and total production has frequently to be extrapolated from estimates for individual countries. Compounds of this type as a rule are highly persistent against biodegradation and belong, as "recalcitrant" chemicals, to the class of so-called xenobiotics. This term is used to characterise chemical substances which have no or limited structural analogy to natural compounds for which degradation pathways have evolved over billions of years. Xenobiotics frequently have some common features. e.g. high octanol/water partitioning coefficients and low water solubility which makes for a high accumulation ratio in the biosphere (bioaccumulation potential). Recalcitrant compounds therefore are found accumulated in mammals, especially in fat tissue, animal milk supplies and also in human milk. Highly sophisticated analytical techniques have been developed for the detection of organochlorines at the trace and ultratrace level

Telomerase in relation to expression of p53, c-Myc and estrogen receptor in ovarian tumours

Telomerase activity and its subunits (hTERC, hTERT mRNA) were evaluated in ovarian tumours in relation to the expression of p53, c-Myc and estrogen receptor (ER). Furthermore, relations between telomerase activity, hTERC and hTERT with known clinicopathologic prognostic factors and survival in patients with malignant tumours was investigated. Telomerase activity was determined with TRAP, hTERC and hTERT with RT-PCR, while p53, c-Myc and ER expression with immunohistochemistry. Telomerase activity and hTERT mRNA were more frequently observed in malignant ovarian tumours compared to borderline and benign tumours, whereas hTERC was present in all tumour types. p53 and c-Myc were more frequently detected in malignant compared to borderline and benign tumours. Telomerase activity was positively related to hTERT mRNA, p53 and c-Myc expression, but not to hTERC and ER expression. In malignant tumours, hTERC levels were related to tumour stage, while telomerase activity and hTERT mRNA expression were not related to any clinicopathologic feature. Tumour stage, differentiation grade, residual tumour after first laparotomy and presence of ascites were related to. (progression free) survival, whereas telomerase activity or its subunits were not. In conclusion, these data suggest that p53 expression (e.g. p53 mutation) as well as c-Myc expression may have a role in regulation of telomerase activity in ovarian tumours