Enrichment of dissolved metal(loid)s and microbial organic matter during transit of a historic mine drainage system.

Water quality degradation by decommissioned mining sites is an environmental issue recognized globally. In the Ore mountains of Central Europe, a wide array of contaminants is released by abandoned under- and aboveground mining sites threatening the quantity and quality of surface and groundwater resources. Here, we focus on the less-explored internal pollution processes within these mines involving organic carbon and microorganisms in trace metal(loid)s mobilization processes. Over an 18-month period, we conducted hydrological and biogeochemical monitoring at the Reiche Zeche mine, a former lead-zinc-silver mine, in Germany, reaching 230 meters below ground, well below the critical zone. Our results show strong seasonal fluctuations in water availability, concentrations of metal(loid)s, pH, and dissolved organic matter (DOM) components across multiple depths. Excess metal(loid) presence during high flow conditions indicated mobilization behavior deviating from conservative dilution. Our findings reveal strong positive correlations between metal(loid) variability and pH (0.894), and between metal(loid) variability and the DOM fluorescent component C2 (-0.910), a proxy for microbial activity. Accordingly, the microbial processes may significantly contribute to the observed metal(loid) composition and fluxes. By elucidating the intricate roles of hydrological and biogeochemical factors in trace metal(loid) mobilization, our research offers a comprehensive framework for improving mine water management and remediation, potentially informing global environmental policies and sustainable mining practices.

Analytical and toxicological aspects of nanomaterials in different product groups: Challenges and opportunities.

The widespread integration of engineered nanomaterials into consumer and industrial products creates new challenges and requires innovative approaches in terms of design, testing, reliability, and safety of nanotechnology. The aim of this review article is to give an overview of different product groups in which nanomaterials are present and outline their safety aspects for consumers. Here, release of nanomaterials and related analytical challenges and solutions as well as toxicological considerations, such as dose-metrics, are discussed. Additionally, the utilization of engineered nanomaterials as pharmaceuticals or nutraceuticals to deliver and release cargo molecules is covered. Furthermore, critical pathways for human exposure to nanomaterials, namely inhalation and ingestion, are discussed in the context of risk assessment. Analysis of NMs in food, innovative medicine or food contact materials is discussed. Specific focus is on the presence and release of nanomaterials, including whether nanomaterials can migrate from polymer nanocomposites used in food contact materials. With regard to the toxicology and toxicokinetics of nanomaterials, aspects of dose metrics of inhalation toxicity as well as ingestion toxicology and comparison between in vitro and in vivo conclusions are considered. The definition of dose descriptors to be applied in toxicological testing is emphasized. In relation to potential exposure from different products, opportunities arising from the use of advanced analytical techniques in more unique scenarios such as release of nanomaterials from medical devices such as orthopedic implants are addressed. Alongside higher product performance and complexity, further challenges regarding material characterization and safety, as well as acceptance by the general public are expected.

Nanomaterials: certain aspects of application, risk assessment and risk communication.

Development and market introduction of new nanomaterials trigger the need for an adequate risk assessment of such products alongside suitable risk communication measures. Current application of classical and new nanomaterials is analyzed in context of regulatory requirements and standardization for chemicals, food and consumer products. The challenges of nanomaterial characterization as the main bottleneck of risk assessment and regulation are presented. In some areas, e.g., quantification of nanomaterials within complex matrices, the establishment and adaptation of analytical techniques such as laser ablation inductively coupled plasma mass spectrometry and others are potentially suited to meet the requirements. As an example, we here provide an approach for the reliable characterization of human exposure to nanomaterials resulting from food packaging. Furthermore, results of nanomaterial toxicity and ecotoxicity testing are discussed, with concluding key criteria such as solubility and fiber rigidity as important parameters to be considered in material development and regulation. Although an analysis of the public opinion has revealed a distinguished rating depending on the particular field of application, a rather positive perception of nanotechnology could be ascertained for the German public in general. An improvement of material characterization in both toxicological testing as well as end-product control was concluded as being the main obstacle to ensure not only safe use of materials, but also wide acceptance of this and any novel technology in the general public.

mRNA expression and protein distribution of the unspliced tenascin-C isoform in prostatic adenocarcinoma.

The inclusion or omission of the alternatively spliced region in the tenascin-C (Tn-C) mRNA gives rise to the large (Tn-C(L)) or small (Tn-C(S)) variant, respectively. Tn-C(L) is thought to be a typical component of provisional extracellular matrices (ECMs) and is expressed during tumour stroma remodelling in cancer. Tn-C(L) mRNA expression and protein distribution have been studied in 44 prostatic adenocarcinomas using RNA/RNA in situ hybridization supplemented by reverse transcriptase-polymerase chain reaction (RT-PCR), and immunohistochemistry (clone BC-2). While the Tn-C(L) protein was demonstrated within tumour stroma, Tn-C(L) mRNA expression was mainly observed in carcinoma cells, regardless of the histological grade of the tumour. Carcinoma cells containing Tn-C(L) mRNA were particularly localized at the tumour invasion front. Tn-C(L) mRNA was also identified in benign prostatic hyperplasia, where it was present exclusively in the basal cell layer, and in prostatic intraepithelial neoplasia in which there was partial loss of positive basal cells and increasing positivity of luminal cells. Furthermore, newly formed tumour blood vessels and inflammatory and stromal cells take part in the expression of Tn-C(L) and are involved in the formation of a provisional tumour matrix. It is concluded that deposits of Tn-C(L) indicate rebuilding processes in non-neoplastic as well as in neoplastic prostatic tissues. In respect of the Tn-C(L) synthesis in budding prostatic carcinoma cells, the results demonstrate that tumour cells can directly produce the ECM components of carcinoma stroma, creating conditions that facilitate the process of invasion.

Near-infrared fluorescence imaging of HER-2 protein over-expression in tumour cells.

The aim of this study was to evaluate in vitro and in vivo imaging of HER-2-over-expressing tumours using near-infrared optical imaging. A fluorochrome probe was designed by coupling Cy5.5 to anti-HER-2 antibodies. Cells over-expressing (SK-BR-3 cells) or normally expressing (PE/CA-PJ34 cells) the HER-2 protein were incubated with the probe. After removing unbound probe molecules, fluorescence intensities were determined (a.u.: arbitrary units). Cells were additionally investigated using FACS and laser scanning microscopy. The probe was also injected intravenously into tumours bearing SK-BR-3 ( n=3) or PE/CA-PJ34 ( n=3). Whole-body fluorescence images were generated and analysed. The incubation of SK-BR-3 cells with the probe led to higher fluorescence intensities [2,133 (+/-143) a.u.] compared to controls [975 (+/-95) a.u.]. The results from FACS and immunocytochemical analysis were in agreement with these findings. A distinct dependency between the fluorescence intensity and the cell number used in the incubations was detected. In vivo, the relative fluorescence intensities in SK-BR-3 tumours were higher than in PE/CA-PJ34 tumours at 16-24 h after probe application. HER-2-over-expressing tumours were depictable in their original size. Labelling of HER-2 with Cy5.5 is suitable for in vitro and in vivo detection of HER-2-over-expressing tumour cells.

Differential in vivo and in vitro expression of ED-B+ fibronectin in adult human hematopoiesis.

Fibronectin in general is involved in adhesion and maturation of the erythroid lineage, in megakaryopoiesis and in the differentiation of human multipotent hematopoietic progenitor cells. However, little information exists about the expression of the oncofetal fibronectin isoform containing the ED-B domain (ED-B+ fn) in adult human hematopoiesis. The study was aimed to analyze the ED-B+ fn expression in normal human bone marrow cells by immunocytochemistry, flow cytometry and reverse-transcriptase polymerase chain reaction. The in vivo results were compared to ED-B+ fn expression in human long-term bone marrow cultures (LTBMC), cytokine supported expansion cultures of CD34+ peripheral blood progenitor cells (PBPC) and in leukemic cell lines with megakaryocytic characteristics (K562, CMK). ED-B+ fn protein was immunocytochemically demonstrated in normal bone marrow megakaryocytes as well as in megakaryocytic progenitor/precursor cells generated ex vivo from PBPC but we failed to detect ED-B+ fn mRNA. It was strongly expressed in LTBMC (RNA and protein). Analysis of human bone marrow mononuclear cells by flow cytometry and confocal microscopy revealed only cytoplasmic ED-B+ fn. The SCF/TPO induced megakaryocytic differentiation of ED-B+ fn negative CMK cells is associated with an increase of large megakaryocytes followed by an intracellular accumulation of ED-B+ fn mRNA and protein. We conclude that in normal human hematopoiesis ED-B+ fn protein expression and intracellular accumulation is restricted to differentiation of megakaryocytes. Low-abundant synthesis, intracellular accumulation and failure of membrane exposure might be due to a function during early events of wound healing (formation of a platelet-rich provisional extracellular matrix).

Immunohistochemical demonstration of the gamma2 chain of laminin-5 in urinary bladder urothelial carcinoma. Impact for diagnosis and prognosis.

The heterotrimeric molecule laminin-5 (Ln-5) represents a main protein of the epithelial adhesions complex. It links the basement membrane (BM) with the hemidesmosomes of the basal urothelial cells. The study was aimed to evaluate invasion associated changes of the epithelial adhesion complex in urothelial carcinoma (UC) monitored by immunohistochemical demonstration of the Ln-5 gamma2 chain. For correlation to UC phenotype and patients outcome, a semiquantitative immunohistochemical analysis of 100 routinely processed paraffin embedded samples (non-invasive and invasive UC) using the antibody D4B5 specific for the Ln-5 gamma2 chain was performed. An increased risk of death is associated with an increased Ln-5 loss from BM (P=0.001), an increase of stroma deposition (P=0.001), as well as an increase of cellular retention of Ln-5 protein (P=0.001) (Kruskal-Wallis test). As shown in multivariate analysis, in addition to tumor stage the cellular retention of Ln-5 is the most important prognostic parameter. In consequence, the modulation of Ln-5 is recommended as a diagnostic marker of invasive UC phenotype.