The Impact of Element–Element Interactions on Antioxidant Enzymatic Activity in the Blood of White Stork (Ciconia ciconia) Chicks

The aim of this work was to determine interrelationships among macroelements Na, K, Ca, Mg, and Fe, microelements Zn, Cu, Mn, and Co, and toxic heavy metals Pb and Cd in the blood of white stork Ciconia ciconia, during postnatal development, in different Polish environments, and their impact on the activity of antioxidant enzymes. We considered the content of thiobarbituric acid-reactive substances (TBARSs), i.e., malondialdehyde (MDA), and activity of superoxide dismutase (SOD), catalase (CAT), ceruloplasmine (CP), glutathione peroxidase (GPx), and glutathione reductase (GR). Blood samples were collected from storks developing at Odra meadows (Kłopot; southwestern Poland). They were compared with blood of chicks from several suburban sites located 20 km away from Zielona Góra (0.1 million inhabitants; southwestern Poland) and near Głogów, where a copper smelter is situated. We also conducted research in the Pomeranian region (Cecenowo; northern Poland). We collected blood samples via venipuncture of the brachial vein of chicks in 2005–2007. They were retrieved from the nest and placed in individual ventilated cotton sacks. The blood was collected using a 5-ml syringe washed with ethylenediaminetetraacetic acid (EDTA). We found significant interactions between macro- and microelements and enzymatic activity and TBARS products. We noticed the predominance of Cd and Pb participation in element–enzyme interactions. Simultaneously, we found interrelationships between cadmium and Na, K, Ca, Mg, and Fe and the activity of antioxidant enzymes SOD, CAT, CP, GR, and TBARS products in the blood of white stork chicks. In the case of lead these relationships were not numerous and they were significant for Ca, Mg, Cu, Mn, and Co. Correlations with enzymes were significant for Pb-CAT and Pb-TBARS. We noted that activities of most enzymes (SOD, CAT, CP, GR) and TBARS products are determined by their interactions with physiological elements Na, Ca, Mg, Fe, and Zn and toxic heavy metals. White stork chicks ranged in age from 17 to 59 days. Concentrations of elements in the blood were age related. Among enzymes, only SOD, CAT, and GPx were age related. Young storks differed in the case of element concentration (except for Ca, Zn, and Cd) and enzymatic activity. We found that significant element–element interaction/enzyme activity predominated in the case of physiological elements and toxic metals, which we explain by the intensive and prevailing access of toxic metals in redox reactions. This causes changes in the priority of these metals, reflected by their influence on the enzymatic activity of antioxidant enzymes. The content of Cd and Pb in blood of young storks from different regions tends to affect the lipid peroxidation process negatively. However, in many cases we observed an increase in enzymatic activity with an increase in heavy metals. This indicates the changes in oxidative stress intensity in chicks in response to environmental differentiation. The increase in lipoperoxidation modifies antioxidant enzyme activity and causes changes in SOD, CAT, CP, GPx, and GR activity in chicks from various regions, principally increases in enzyme activity in chicks from polluted environments and suburbs. We suggest that the source of heavy metals in chicks’ blood might be used as a biological test system of adaptation to oxidative stress. We also report that a high level of heavy metals is accompanied by increased lipid peroxidation. Thus young storks are probably significantly susceptible to environmental conditions. They demonstrated initiation of lipoperoxidation and oxidative modification of proteins that coincide with chemical elements, as a possible antioxidant defense system.     

The actin cytoskeleton differentially regulates platelet alpha-granule and dense-granule secretion

Stimulation of platelets with strong agonists results in centralization of cytoplasmic organelles and secretion of granules. These observations have led to the supposition that cytoskeletal contraction facilitates granule release by promoting the interaction of granules with one another and with membranes of the open canalicular system. Yet, the influence of the actin cytoskeleton in controlling the membrane fusion events that mediate granule secretion remains largely unknown. To evaluate the role of the actin cytoskeleton in platelet granule secretion, we have assessed the effects of latrunculin A and cytochalasin E on granule secretion. Exposure of platelets to low concentrations of these reagents resulted in acceleration and augmentation of agonist-induced alpha-granule secretion with comparatively modest effects on dense granule secretion. In contrast, exposure of platelets to high concentrations of latrunculin A inhibited agonist-induced alpha-granule secretion but stimulated dense granule secretion. Incubation of permeabilized platelets with low concentrations of latrunculin A primed platelets for Ca(2+)- or guanosine triphosphate (GTP)-gamma-S-induced alpha-granule secretion. Latrunculin A-dependent alpha-granule secretion was inhibited by antibodies directed at vesicle-associated membrane protein (VAMP), demonstrating that latrunculin A supports soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein-dependent membrane fusion. These results indicate that the actin cytoskeleton interferes with platelet exocytosis and differentially regulates alpha-granule and dense granule secretion.     

Dissemination of Misinformative and Biased Information about Prostate Cancer on YouTube

YouTube is a social media platform with more than 1 billion users and >600 000 videos about prostate cancer. Two small studies examined the quality of prostate cancer videos on YouTube, but did not use validated instruments, examine user interactions, or characterize the spread of misinformation. We performed the largest, most comprehensive examination of prostate cancer information on YouTube to date, including the first 150 videos on screening and treatment. We used the validated DISCERN quality criteria for consumer health information and the Patient Education Materials Assessment Tool, and compared results for user engagement. The videos in our sample had up to 1.3 million views (average 45 223) and the overall quality of information was moderate. More videos described benefits (75%) than harms (53%), and only 50% promoted shared decision-making as recommended in current guidelines. Only 54% of the videos defined medical terms and few provided summaries or references. There was a significant negative correlation between scientific quality and viewer engagement (views/month p = 0.004; thumbs up/views p = 0.015). The comments section underneath some videos contained advertising and peer-to-peer medical advice. A total of 115 videos (77%) contained potentially misinformative and/or biased content within the video or comments section, with a total reach of >6 million viewers.

Phytoremediation of Cadmium by Native Plants Grown on Mining Soil

The Gümüsköy mining area is located about 25 km west of Kutahya and is the largest silver deposit in Turkey. The present study investigated translocation and accumulation of cadmium (Cd) from the soil into 11 native plants. Plant and soil samples were collected from the field, and Cd concentrations were analyzed by inductively coupled plasma mass spectroscopy. Mean Cd values in the soil, root, and shoot of native plants in the study area were 82.8?±?5, 55.4?±?6, and 43.5?±?4 mg kg^??1, respectively. Plants were separated into several groups according to the enrichment coefficients for shoot and root values of plants. These groups showed Carduus nutans and Phlomis could be potentially bioaccumulator plants useful for phytoremediation of mining soils contaminated by Cd.     

Subcellular distribution of 3 functional platelet SNARE proteins: human cellubrevin,SNAP-23, and syntaxin 2

Morphologic studies have demonstrated a process by which alpha-granule contents are released from platelets. Studies aimed at defining the molecular mechanisms of this release have demonstrated that SNARE proteins are required for alpha-granule secretion. These observations raise the possibility that morphologic features of alpha-granule secretion may be influenced by the subcellular distribution of SNARE proteins in the platelet. To evaluate this possibility, we analyzed the subcellular distribution of 3 functional platelet SNARE proteins-human cellubrevin, SNAP-23, and syntaxin 2. Exposure of streptolysin O-permeabilized platelets to antihuman cellubrevin antibody inhibited Ca(++)-induced alpha-granule secretion by approximately 50%. Inhibition of alpha-granule secretion by antihuman cellubrevin was reversed by a blocking peptide. Syntaxin 2 and SNAP-23 have previously been demonstrated to mediate platelet granule secretion. The subcellular localization of the 3 SNARE proteins was determined by ultrastructural studies, using a pre-embedding immunonanogold method, and by immunoblot analysis of subcellular fractions. Immunonanogold localization demonstrated that approximately 80% of human cellubrevin in resting platelets was localized to platelet granule membranes. In contrast, SNAP-23 localized predominantly to plasma membrane, whereas syntaxin 2 was more evenly distributed among membranes of alpha-granules, the open canalicular system, and plasma membrane. Thus, each of these SNARE proteins has a distinct subcellular distribution in platelets, and each of these membrane compartments demonstrates a unique SNARE protein composition. This distribution provides a basis for several characteristics of alpha-granule secretion that include homotypic alpha-granule fusion and the fusion of alpha-granules with the open canalicular system and plasma membrane.     

The distribution pattern of ERα expression,ESR1 genetic variation and expression of growth factor receptors: association with breast cancer prognosis in Russian patients treated with adjuvant tamoxifen

Identification of additional biomarkers associated with ER genomic and nongenomic pathways could be very useful to distinguish patients who will benefit from tamoxifen treatment. The aim of this study was to analyze the prognostic significance of the distribution pattern of ERα expression, ESR1 gene single-nucleotide polymorphisms and expression levels of growth factor receptors in Russian hormone receptor-positive breast cancer patients treated with adjuvant tamoxifen. Formalin-fixed paraffin-embedded tumor tissue samples from 97 patients were examined for the distribution pattern of ERα expression, as well as for EGFR and TGF-βR1 expression by immunohistochemistry. Genotypes for ESR1 +30T>C (rs2077647) and ESR1 2014G>A (rs2228480) were analyzed using a TaqMan assay. Progression-free survival (PFS) was used as an endpoint for the survival analyses. We found that patients with the heterogeneous distribution of ERα expression had poor prognosis on tamoxifen treatment (P = 0.021). We identified a high EGFR expression in patients who developed distant metastasis or recurrence during tamoxifen treatment (a tamoxifen-resistant group—TR) in contrast to the distant metastasis-free patients (a tamoxifen-sensitive group—TS) (80.0 vs. 41.9 %, respectively, P = 0.009). Carriers of the ESR12014A mutant allele were more prevalent among the TR patients compared to the TS patients (26.3 vs. 8.0 %, respectively, P = 0.009). EGFR expression and the distribution pattern of ERα expression were associated with the response to tamoxifen by both univariate and multivariate logistic regression analyses. The presence of these markers either alone or in combination was correlated with the worse PFS for all patients. Analysis of the distribution pattern of ERα expression and the EGFR status in tumor tissue may be valuable for patient selection for tamoxifen adjuvant therapy.