Structure of the ovaries and oogenesis in Cixius nervosus (Cixiidae), Javesella pellucida and Conomelus anceps (Delphacidae) (Insecta, Hemiptera, Fulgoromorpha)

Ovary organization in representatives of two families of Fulgoromorpha, Cixiidae (Cixius nervosus) and Delphacidae (Javesella pellucida and Conomelus anceps), was examined by light and transmission electron microscopy. Ovaries of studied fulgoromorphans consist of telotrophic ovarioles. From apex to base individual ovarioles have four well defined regions: a terminal filament, tropharium (trophic chamber), vitellarium and pedicel (ovariolar stalk). Tropharia are not differentiated into distinct zones and consist of syncytial lobes containing multiple trophocyte nuclei embedded in a common cytoplasm. Lobes are radially arranged around a branched, cell-free trophic core. Early previtellogenic (arrested) oocytes and prefollicular cells are located at the base of the tropharium. The vitellarium houses linearly arranged developing oocytes each of which is connected to the trophic core by a broad nutritive cord. Each oocyte is surrounded by a single layer of follicular cells that become binucleate at the beginning of vitellogenesis.     

N-terminal brain natriuretic propeptide levels correlate with procalcitonin and C-reactive protein levels in septic patients

The aim of this study was to find the relationship between N-terminal brain natriuretic propeptide (NT-proBNP), procalcitonin (PCT) and C-reactive protein (CRP) plasma concentrations in septic patients. This was a prospective study, performed at Medical University Hospital No. 5 in łódź. Twenty patients with sepsis and severe sepsis were included in the study. N-terminal brain natriuretic propeptide, procalcitonin and C-reactive protein concentrations, and survival were evaluated. In the whole studied group (128 measurements), the mean NT-proBNP, procalcitonin and C-reactive protein concentrations were, respectively: 140.80±84.65 pg/ml, 22.32±97.41 ng/ml, 128.51±79.05 mg/l. The correlations for the NT-proBNP level and procalcitonin and C-reactive protein levels were 0.3273 (p<0.001) and 0.4134 (p<0.001), respectively. NT-proBNP levels correlate with PCT and CRP levels in septic patients. In the survivor subgroup, the mean NT-proBNP plasma concentrations were significantly lower than in the non-survivor subgroup.     

Analysis of 5-methylcytosine in DNA of breast and colon cancer tissues

5-methylcytosine (m(5)C) can be used as a sensitive marker of progress of the tumor formation induced by the oxidative damage reactions. We have analyzed the amount of m(5)C in DNA of patients with breast and colon cancers. Two dimensional thin layer chromatography (TLC) has been used to monitor 5-methylcytosine level in DNA extracted from cancer tissues. The level of methylation of cytosine at C-5 position in DNA from breast cancer patients correlates well with the malignancy of tumors. Interestingly higher amount of m(5)C in DNA for the breast cancer patients treated with different chemotherapeutics was observed. It suggests an activation of DNA methyltransferase as well as a genomic suppression of the DNA repair genes expression. These differences clearly reflect the health condition of patients and support the global analysis of m(5)C in DNA as a good marker for diagnosis of neoplasia in clinical practice.     

Synthesis and antiviral properties of aza-analogues of acyclovir

Aza-analogues of Acyclovir were obtained from N-(2-pivaloyloxyethyl)-N-(pivaloyloxymethyl)-p-toluenesulfonamide via a one-pot base silylation/nucleoside coupling procedure. The antiviral activities of all aza-nucleosides in vitro against a variety of viruses were evaluated. None of these compounds displayed any specific antiviral effects.     

Melatonin and thyroxine response to pollution in white stork nestlings (Ciconia ciconia): aspects of rhythmicity and age

There is growing evidence that ubiquitous environmental contaminants may interfere with vertebrate endocrine systems. The selected endocrine biomarkers are used to indicate the condition of free-ranging populations of wildlife, including avian species. The aim of this study was to determine the impact of environment quality on serum thyroxine (T4) and melatonin (Mel) in white stork nestlings (Ciconia ciconia) living in different locations: small villages in natural areas surrounded by forests and crop fields, near the city and near the copper smelter. We extended our analyses to examine the hormones' day-night changes in conjunction with chicks' age. Total serum T4 and Mel was measured by RIA. T4 level, as a decisive measure of thyroid hormone productivity, was significantly lower in the nestlings exposed to pollutants from the copper smelter. Mel, as a well-known scavenger of free radicals, was elevated in the nestlings in the area near the copper smelter. This study indicates that alteration in T4 and Mel levels could be a useful marker of exposure of nestling wild storks to different toxic substances in field studies. Mel is postulated to be a susceptible defensive molecule as a protective mechanism for organisms.     

A reversible decrease in ribulose 1,5‐bisphosphate carboxylase/oxygenase carboxylation activity caused by the aggregation of the enzyme's large subunit is triggered in response to the exposure of moderate irradiance‐grown plants to low irradiance

Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) is highly regulated in response to fluctuations in the environment, including changes in irradiance. However, no complex data are available on Rubisco regulatory mechanisms triggered in plants which are submitted to moderate–low irradiance shift. Therefore, we investigated in a comprehensive way the changes at the level of amount of Rubisco protein, its structural organization and carboxylase activity of the holoenzyme as triggered by exposure of moderate irradiance‐grown Arabidopsis thaliana plants to low irradiance conditions. An exposure of moderate irradiance‐grown plants to low irradiance for a single photoperiod caused the exclusion of a certain pool of Rubisco under altered conditions owing to oxidative modifications resulting in the formation of protein aggregates involving Rubisco large subunit (LS). As a result, both initial and total Rubisco carboxylase activities were reduced, whereas Rubisco activation state remained largely unchanged. The results of the determination of reactive oxygen species indicated that a moderate/low irradiance transition had stimulated ¹O₂ accumulation and we strongly suggest that Rubisco oxidative modifications leading to formation of aggregates encompassing Rubisco‐LS were triggered by ¹O₂. When moderate irradiance regime was resumed, the majority of Rubisco‐LS containing aggregates tended to be resolubilized, and this allowed Rubisco carboxylation activities to be largely recovered, without changes in the activation state of the enzyme. In the longer term, these results allow us to better understand a complexity of Rubisco regulatory mechanisms activated in response to abiotic stresses and during recovery from the stresses.     

Physiological and antioxidant responses of two accessions of Arabidopsis thaliana in different light and temperature conditions

During their lifetime, plants need to adapt to a changing environment, including light and temperature. To understand how these factors influence plant growth, we investigated the physiological and antioxidant responses of two Arabidopsis accessions, Shahdara (Sha) from the Shahdara valley (Tajikistan, Central Asia) in a mountainous area and Lovvik‐5 (Lov‐5) from northern Sweden to different light and temperature conditions. These accessions originate from different latitudes and have different life strategies, both of which are known to be influenced by light and temperature. We showed that both accessions grew better in high‐light and at a lower temperature (16°C) than in low light and at 23°C. Interestingly, Sha had a lower chlorophyll content but more efficient non‐photochemical quenching than Lov‐5. Sha, also showed a higher expression of vitamin E biosynthetic genes. We did not observe any difference in the antioxidant prenyllipid level under these conditions. Our results suggest that the mechanisms that keep the plastoquinone (PQ)‐pool in more oxidized state could play a role in the adaptation of these accessions to their local climatic conditions.     

The temperature–size rule in a rotifer is determined by the mother and at the egg stage

In most ectotherms, compared with development at low temperatures, development at high temperatures results in the acceleration of maturation, which in turn results in a smaller size (temperature–size rule, TSR). It is not known at which developmental stages this thermal response is determined. We exposed different life stages of the rotifer Lecane inermis to 15, 20, or 25 °C to determine whether the TSR in the F1 generation is governed by the thermal conditions experienced by the mothers (F0 generation) during their development, during egg production, or during the development of the eggs or hatchlings. We found that the adult size was affected by the thermal conditions experienced by the mothers and embryos, but not by the conditions during post-hatching growth. We suggest that the thermal plasticity producing the TSR in rotifers may reflect the joint impacts of a maternal effect and a direct effect of the environment during egg development. The two-point control of the TSR resembles the thermal determination of other biological phenomena, similar to the thermally determined sex determination in ectotherms. Our results contribute not only to better understanding the proximate mechanisms of TSR, but also to comprehending the general biological mechanisms of response to temperature, which is one of the most important ecological factors.     

Essential Oils,Silver Nanoparticles and Propolis as Alternative Agents Against Fluconazole Resistant Candida albicans,Candida glabrata and Candida krusei Clinical Isolates

Development of effective and safe therapeutic treatment of fungal infections remains one of the major challenge for modern medicine. The aim of presented investigation was to analyze the in vitro antifungal activity of selected essential oils, ethanolic extracts of propolis and silver nanoparticles dropped on TiO₂ against azole-resistant C. albicans (n = 20), C. glabrata (n = 14) and C. krusei (n = 10) clinical isolates. Among tested essential oils, the highest activity has definitely been found in the case of the oil isolated from the bark of Cinnamomum cassia, with MIC and MFC values for all tested strains in the range of 0.0006–0.0097 % (v/v) and 0.0012–0.019 % (v/v), respectively. High activity was also observed for the Lemon, Basil, Thyme, Geranium and Clove (from buds) essential oils. Significant differences in fungicidal activity have been observed in the case of four tested propolis samples. Only one of them revealed high activity, with MFC values in the range from 0.156 to 1.25 % (v/v). Satisfactory fungicidal activity, against C. albicans and C. glabrata isolates, was also observed in the case of silver nanoparticles, however C. krusei isolates were mostly resistant. We also revealed that constituents of most of essential oils and propolis as well as silver nanoparticles are not substrates for drug transporters, which belong to the most important factors affecting resistance of Candida spp. clinical isolates to many of conventional antimycotics. To conclude, the results of our investigation revealed that essential oils, propolis and silver nanoparticles represent high potential for controlling and prevention candidiasis.