Spectroscopic identification of benign (follicular adenoma) and cancerous lesions (follicular thyroid carcinoma) in thyroid tissues.

Thyroid follicular nodules are quite common in the population, however only a small proportion is malignant. Thyroid cancer differs from adenoma by features of cellular atypia, angioinvasiveness and possibility of metastasis via blood vessels mainly in the lungs and bones. Pathomorphological examination of the postoperative material plays a significant role in the diagnosis of cystic thyroid lesions. De facto, there is no possibility to determine with certainty whether the lesion is benign or malignant before surgery, therefore new methods are being sought to meet clinical needs. The study aimed to investigate if Fourier-transform infrared spectroscopy (FTIR) spectroscopy and Raman spectroscopy combined with multidimensional analysis can be a useful tool in distinguishing between thyroid adenomas and carcinomas. The obtained results indicate quantitative and qualitative alterations within proteins and fats derived from patients' tissues samples. Raman spectroscopy additionally shows significant changes in the amount of tissue collagen due to the pathogenic process. In the spectra of the second FTIR derivative, shifts of vibrations corresponding to the ß-sheet and α-helix structure are observed towards the lower rates of wave numbers in the case of neoplastic tissues. Using the leave-one-out cross-validation, sensitivity and specificity calculated with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA) clearly shows the possibility to distinguish between pathologically changed and normal thyroid tissue as well as differentiate follicular thyroid adenoma (FTA) from widely invasive follicular thyroid carcinoma (WI-FTC) tissues.

How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the evolution of life on Earth.

One of the former definitions of "obligate anaerobiosis" was based on three main criteria: 1) it occurs in organisms, so-called obligate anaerobes, which live in environments without oxygen (O2), 2) O2-dependent (aerobic) respiration, and 3) antioxidant enzymes are absent in obligate anaerobes. In contrast, aerobes need O2 in order to grow and develop properly. Obligate (or strict) anaerobes belong to prokaryotic microorganisms from two domains, Bacteria and Archaea. A closer look at anaerobiosis covers a wide range of microorganisms that permanently or in a time-dependent manner tolerate different concentrations of O2 in their habitats. On this basis they can be classified as obligate/facultative anaerobes, microaerophiles and nanaerobes. Paradoxically, O2 tolerance in strict anaerobes is usually, as in aerobes, associated with the activity of the antioxidant response system, which involves different antioxidant enzymes responsible for removing excess reactive oxygen species (ROS). In our opinion, the traditional definition of "obligate anaerobiosis" loses its original sense. Strict anaerobiosis should only be restricted to the occurrence of O2-independent pathways involved in energy generation. For that reason, a term better than "obligate anaerobes" would be O2/ROS tolerant anaerobes, where the role of the O2/ROS detoxification system is separated from O2-independent metabolic pathways that supply energy. Ubiquitous key antioxidant enzymes like superoxide dismutase (SOD) and superoxide reductase (SOR) in contemporary obligate anaerobes might suggest that their origin is ancient, maybe even the beginning of the evolution of life on Earth. It cannot be ruled out that c. 3.5 Gyr ago, local microquantities of O2/ROS played a role in the evolution of the last universal common ancestor (LUCA) of all modern organisms. On the basis of data in the literature, the hypothesis that LUCA could be an O2/ROS tolerant anaerobe is discussed together with the question of the abiotic sources of O2/ROS and/or the early evolution of cyanobacteria that perform oxygenic photosynthesis.

Influence of salicylic acid pretreatment on seeds germination and some defence mechanisms of Zea mays plants under copper stress.

The study was focused on the influence of salicylic acid (SA) on maize seeds germination and on some physiological and biochemical processes in maize plants growing in the hydroponic culture under copper (Cu) stress. A significant influence of SA pretreatment on the advanced induction of the maize seeds metabolic activity and the level of the endogenous SA in germinated seeds and developing roots have been stated. Although, the ability of maize seeds to uptake SA and accumulate it in the germinated roots was confirmed, the growth inhibition of Cu-stressed maize seedlings was not ameliorated by SA seeds pretreatment. Cu-stressed plants exhibited a decrease in the photosynthetic pigment concentration and the increase in non-photochemical quenching (NPQ) - an indicator of an excess energy in PSII antenna assemblies lost as a heat. The amelioration effect of SA application was found only for carotenoids content which increased in stressed plants. It was also shown that maize roots growing in stress conditions significantly differed in the chemical composition in comparison to the roots of control plants, but the SA pretreatment did not affect these differences. On the other hand, it was found that SA seed pretreatment significantly influenced the ability of stressed plants to accumulate copper in the roots. It was stated that a higher level of exogenous SA application led to a lower accumulation of Cu ions in maize roots. Cu-stressed plants exhibited higher oxidative stress in roots than in leaves which was manifested as an increase in the concentration of hydrogen peroxide due to stress factor application. We observed an increase in catalase (CAT) activity in leaves of Cu-stressed plants which corresponded with a lower H2O2 content when compared with roots where the hydrogen peroxide level was higher, and the inhibition of the CAT activity was found. Furthermore, we found that the SA seed pretreatment led to a decrease in the H2O2 content in the roots of the Cu-stressed plants, but it did not influence the H2O2 level in leaves. The increase in hydrogen peroxide content in the roots of Cu-stressed plants correlated with a higher activity of the MnSODI and MnSODII isoforms. It was found that SA pretreatment caused a decrease in MnSODII activity accompanied by the decrease in H2O2 concentration. Achieved results indicated also that the changes in the chemical composition of the root tissue under copper stress constituted protection mechanisms of blocking copper flow into other plant organs. However, it might be assumed that the root tissue remodelling under Cu stress did not only prevent against the Cu ions uptake but also limited the absorption of minerals required for the normal growth leading to the inhibition of the plant development.