Using of chicken antibodies for metallothionein detection in human blood serum and cadmium‐treated tumour cell lines after dot‐ and electroblotting

Metallothionein (MT) is a low‐molecular mass protein playing an essential role in homeostasis of heavy metal ions. Its relation with formation and progression of a tumour disease is discussed in this article. Here, we propose a new methodological approach for visualization of MT on PVDF membranes after dot‐ and electroblotting by using a commercial mouse monoclonal antibody E9 and polyclonal chicken antibodies. The optimized procedure was as follows. We dotted 1 μL sample volume on PVDF membrane and let it to dry. Then, we blocked the membrane surface with 2% BSA in PBS for 30 min. After that, the membrane was incubated in chicken primary antibody (diluted 1:500), washed, and incubated in rabbit‐anti‐chicken secondary antibody conjugated with horseradish peroxidase. To visualize the interaction, we used 3‐aminoethyl‐9‐carbazole. Under these conditions, we estimated detection limit as 3 pg of MT per 1 μL. The optimal approach was further utilized for detection of MT level in two human fibroblast cell lines and in blood serum obtained from children with medulloblastoma. The results were in good agreement with differential pulse voltammetry‐Brdicka reaction.     

Enumeration of order preserving maps

Three results are obtained concerning the number of order preserving maps of an n-element partially ordered set to itself. We show that any such ordered set has at least 2 ^2n/3 order preserving maps (and 2 ² in the case of length one). Precise asymptotic estimates for the numbers of self-maps of crowns and fences are also obtained. In addition, lower bounds for many other infinite families are found and several precise problems are formulated.Supported by ONR Contract N00014-85-K-0769.Supported by NSF Grant DMS-9011850.Supported by NSERC Grants 69-3378 and 69-0259.     

Preparation and structural characterization of RuS2 nanoislands on Au(111)

Among all the transition metal sulfides, ruthenium sulfide (RuS2) has been shown to be the most active catalyst for the hydrodesulfuriztion processes. Using X-ray photoemission spectroscopy (XPS) and scanning tunneling microscopy (STM), we have found a novel approach for the preparation of RuS2 nanoislands on an Au(111) substrate. Chemical vapor deposition of Ru3(CO)12 leads to metallic Ru nanoclusters on the gold substrate. Although sulfidation has not been observed on extended Ru (0001) surface, Ru nanoclusters react with S2, forming ruthenium sulfide. While the majority of the sulfide is in the form of nanosized clusters that aggregate into clustered islands, a small fraction of the sulfide is seen as flat islands. When Ru3(CO)12 was deposited on a sulfur-modified gold substrate at elevated temperature, flat islands of ruthenium sulfide are formed exclusively. The flat islands are single-layer RuS2 nanocrystals with a (111) surface termination which exhibits an ordered array of sulfur vacancies. On such RuS2 (111) surfaces, excess sulfur is stable at low temperature and induces surface reconstruction, and desorbs at high temperature. The RuS2(111)/Au system provides an excellent model system for ruthenium sulfide catalysts.     

Die Wirkung von Flüssigkeitsdämpfen auf den Geigerschen Spitzenzähler

Ohne Zusammenfassung

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A bisphosphonate monoamide analogue of DOTA: a potential agent for bone targeting

A new macrocyclic DOTA-like ligand (BPAMD) for bone imaging and therapy containing a monoamide bis(phosphonic acid) bone-seeking group was designed and synthesized. Its lanthanide(III) complexes were prepared and characterized by 1H and 31P NMR spectroscopy. The Gd(III)-BPAMD complex was investigated in detail by 1H and 17O relaxometric studies to inspect parameters relevant for its potential application as an MRI contrast agent. Sorption experiments were conducted with Gd(III) and Tb(III) complexes using hydroxyapatite (HA) as a model of bone surface. Very effective uptake of the Gd-BPAMD complex by the HA surface was observed in NMR experiments. Radiochemical studies with the (160Tb-BPAMD)-HA system proved the sorption to be remarkably fast and strong on one hand and fully reversible on the other hand. The strong (Gd-BPAMD)-HA interaction was also supported by 1H NMRD measurements in the presence of a hydroxyapatite slurry, which showed an increase of the rotational correlation time upon adsorption of the complex on the HA surface, resulting in a significant relaxivity enhancement. The amide-bis(phosphonate) moiety is the only factor responsible for the binding of the complex to HA.