Is callose a barrier for lead ions entering <Emphasis Type="Italic">Lemna minor</Emphasis> L. root cells?

Plants have developed a range of strategies for resisting environmental stresses. One of the most common is the synthesis and deposition of callose, which functions as a barrier against stress factor penetration. The aim of our study was to examine whether callose forms an efficient barrier against Pb penetration in the roots of Lemna minor L. exposed to this metal. The obtained results showed that Pb induced callose synthesis in L. minor roots, but it was not deposited regularly in all tissues and cells. Callose occurred mainly in the protoderm and in the centre of the root tip (procambial central cylinder). Moreover, continuous callose bands, which could form an efficient barrier for Pb penetration, were formed only in the newly formed and anticlinal cell walls (CWs); while in other CWs, callose formed only small clusters or incomplete bands. Such an arrangement of callose within root CWs inefficiently protected the protoplast from Pb penetration. As a result, Pb was commonly present inside the root cells. In the light of the results, the barrier role of callose against metal ion penetration appears to be less obvious than previously believed. It was indicated that induction of callose synthesis is not enough for a successful blockade of the stress factor penetration. Furthermore, it would appear that the pattern of callose distribution has an important role in this defence strategy.     

Antiproliferative activity of salinomycin and its derivatives

Antiproliferative activity of seven amides and one benzotriazole ester derivative of salinomycin, a polyether ionophore antibiotic, with recently reported antibacterial activity, are herein described. Salinomycin and the majority of derivatives exhibit potent antiproliferative activity against the drug-resistant cancer cell lines. Moreover almost all derivatives show stronger activity against LoVo/DX cell line than that of unmodified salinomycin.     

Organelle evolution: Paulinella breaks a paradigm

It is commonly assumed that transformations of endosymbionts into organelles are exceptionally rare evolutionary events because of hypothetical difficulties in the origin of an import apparatus for nuclear-encoded, organelle-targeted proteins along with their targeting signals. A challenge to this view comes from recent studies of protein import into the cyanobacterial endosymbionts/organelles of Paulinella chromatophora.     

Long-term changes in numbers of geese stopping over and wintering in south-western Poland

South-western Poland belongs to the key staging areas for geese in Europe, supporting some 100000 birds in recent years. We compared goose counts conducted in the 1970s, 1990s and during 2009–2011 in this region, and linked the findings to the recent assessments of trends in the flyway-populations. Numbers increased several dozen times between the first two counts and have stabilized to the present. More than 14% of the flyway Tundra Bean Goose (Anser fabalis rossicus) stopped over in SW Poland on passage. Smaller numbers of White-fronted Goose (A. albifrons), Greylag Goose (A. anser), and four other rarer species, have all increased since the 1970s. The likely factors responsible for these changes are mild weather conditions, increased availability of large water bodies and shifts in winter ranges of particular species. Temporal mismatch between SW Poland and the total flyways in Bean and White-fronted Geese was recorded when we compared the long-term and the short-term population trends. Increasing reports of other species in SW Poland match the general tendencies in Europe. These data document that regional trends are not a simple reflection of those in flyways as a whole. To understand changes in goose populations a re-established international count network is desired.     

Enzymatic antioxidant system in the cestode Hymenolepis diminuta after chronic infection of the rat

Background

The aim of the present paper was to describe the enzymatic antioxidant system in Hymenolepis diminuta collected from rats exposed to chronic cestode invasion.

Methodology

We dissected different tissues of H. diminuta (immature proglottids, genital primordia, hermaphroditic proglottids, early uterus, and gravid uterus) and studied activity of: superoxide dismutases (SOD1 and SOD2), catalase (CAT), glutathione peroxidases (non-Se-dependent GSHPx and Se-dependent GSHPx), glutathione-S-transferase (GST) and glutathione reductase (GSHR), and oxidative stress markers ?? reduced glutathione (GSH), and the lipid peroxidation level (TBARS).

Results

We demonstrated changes in antioxidant enzyme activities and levels of oxidative stress markers in different tissues of the parasite. The levels of TBARS and GSH indicate that oxidative stress occurred in tissues located proximal to the intestine wall. Activity of SOD1 was high in all parts of H. diminuta, but the GST activity was the highest of all studied antioxidant enzymes. SOD2 activity differed significantly in various parts of H. diminuta. Significant differences were observed for nonSeGSHPx and activity of other GSH-dependent enzymes was generally similar in all the tissues.

Conclusions

Our results show that the enzymatic antioxidant system of H. diminuta, allows the parasite to adapt and live under conditions of chronic oxidative stress. It suggests an oxidative-antioxidative balance during interactions between parasite and host.     

Endozoochorous dispersal of alien and native plants by two palearctic avian frugivores with special emphasis on invasive giant goldenrod <Emphasis Type="Italic">Solidago gigantea</Emphasis>

The role of frugivorous birds in dispersal of the seeds of fleshy-fruited plants is well understood, but other groups of birds like granivores and omnivores can also act as vectors, especially in the process of non-standard dispersal. In this study we examined the role of two widely distributed birds (the Eurasian Blackbird, Turdus merula, and the Black Redstart, Phoenicurus ochruros) in seed dispersal. We analyzed the content of 279 droppings of the Black Redstart collected between July and October and 85 droppings of the Eurasian Blackbird collected during January. In total we found 366 seeds, representing 11 plant taxa, in the faecal samples; 93% of the seeds belonged to fleshy-fruited species. The most numerous were two native taxa, Sambucus racemosa/nigra, in summer and autumn, Crataegus monogyna in winter, and one alien species Morus alba, which is dispersed in summer. We also found seeds of four dry-fruited species; the most interesting of which was the presence of anemochorous seeds of Solidago gigantea (a highly invasive alien species). The seeds were found only in droppings of the Eurasian Blackbird. Considering the obtained results the need for further studies on bird-plant interactions should be a priority.     

Dependence between Cu concentration in the liver,kidneys and skeletal muscles of canine females

The aim of the investigations was the determination of the Cu contents in the liver, kidneys and skeletal muscles of canine females. Material for research was collected post mortem from 45 animals aged 1 to 18 years coming from the Warsaw area. The effect of the health state, age and life conditions on the distribution of copper in the investigated organs was estimated. That element was determined using the method of inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the liver, the average Cu contents amounted to 24.04 mg kg⁻¹ wet weight, in kidneys to 2.90 mg kg⁻¹ wet weight and in muscles to 0.94 mg kg⁻¹ wet weight. The highest values of copper content in particular tissues and organs were noted in the group of animals with neoplastic changes. In respect to the animal age the highest mean values of the copper content were noted in the oldest animals. They amounted to 30.97 mg kg⁻¹ in the liver, 3.34 mg kg⁻¹ in kidneys and 1.18 mg kg⁻¹ wet weight in muscles. Considering life conditions of the dogs it was observed that the higher mean values in all the investigated organs occurred in dogs coming from the urban areas.     

Analysis of O6-methylguanine-DNA methyltransferase methylation status in sporadic colon polyps

Background/aimThe aim of our study was to check how MGMT methylation status together with known factors influenced the risk of colon cancer development.Materials and methodsWe examined patients with colon polyps. Information concerning gender, age, lifestyle, diet, anthropometry and medical information, including cancer and family history of cancer, was analyzed. Polymorphism variety of MGMT gene was investigated in another study. Genetic analysis for MGMT methylation assessment was performed for polyp tissue samples from 143 patients.ResultsPositive methylation MGMT status was found in 55 patients. There was no correlation between gender and MGMT methylation status (p = 0.43). We did not find correlation between patients younger and older than 60 (p = 0.87). There was no correlation between smoking and MGMT methylation status (p = 0.36). We did not find correlation between BMI and MGMT methylation status (p = 0.86). We did not find correlation between MGMT methylation status and colon cancer in familial history (p = 0.45).ConclusionOur study showed no correlations between methylation status of MGMT polymorphisms and clinical features like age, gender, polyp localization, smoking status, or obesity. It has been shown previously that MGMT methylation status may show nonspecific methylation in colon polyps. Gene methylation status in adenoma tissues has also been associated by other authors with the adenoma's size, histology, and degree of atypia. In our study, we evaluated the gene methylation status in colon polyps and found no association with adenoma characteristics. The present study showed no correlation for MGMT methylation in polyps in different regions of colon.     

Long-term follow-up in adult patients with low-grade glioma (WHO II) postoperatively irradiated. Analysis of prognostic factors

AimTo report the long-term follow-up of a cohort of adult patients with LGG post-operatively irradiated in one institution, and to identify prognostic factors for progression free survival.BackgroundThere is little consensus about the optimal treatment for low-grade glioma (LGG), and the clinical management of LGG is one of the most controversial areas in neurooncology. Radiation therapy is one option for treatment of patients with LGG, whereas other options include postoperative observation.Materials and methodsBetween 1975 and 2005, 180 patients with LGG (WHO II) received postoperative irradiation after non radical (subtotal or partial) excision. Patients had to be 18 years of age or older, and have histologic proof of supratentorial fibrillary (FA), protoplasmic (PA) or gemistocytic astrocytoma (GA). Radiotherapy was given within 3–10 weeks after surgery. Treatment fields were localized and included the preoperative tumor volume, with a 1–2 cm margin, treated to a total dose of 50–60 Gy in 25–30 fractions over 5–6 weeks.ResultsActuarial ten-year progression free survival (APFS) in the whole group was 19%. The worse prognosis was observed in patients with GA. Ten-year APFS rates for GA, PA and FA were 10%, 18% and 22%, respectively.ConclusionThe findings from our long-term cohort of 180 patients with LGG confirmed by uni- and multivariate analysis demonstrated that only astrocytoma histology significantly determined the prognosis. The best survival was observed in patients with the fibrillary variant, and the worst for the gemistocytic one.