Photodynamic properties of tungsten iodide clusters incorporated into silicone: A2[M6I8L6]@silicone

The light-induced antibacterial and antifungal properties of A₂[M₆I₈L₆] with M = Mo and W, A = organic cation, L = ligand have been studied. The photoactive compounds (TBA)₂[W₆I₈(C₇H₇SO₃)₆] and (TBA)₂[W₆I₈(COOCF₃)₆] have been incorporated into a permeable silicone matrix and were measured for their application in the decomposition of multi-resistant bioactive species (hospital germs) such as S. aureus and P. aeruginosa as well as fungi. In addition, we present a new high volume synthesis route for these types of cluster compounds departing from the soluble compound W₆I₂₂.

The light-induced antibacterial and antifungal properties of A₂[M₆I₈L₆] with M = Mo and W, A = organic cation, L = ligand have been studied.     

Frequency-dependent breakdown of wave propagation into fibrillatory conduction across the pectinate muscle network in the isolated sheep right atrium

Atrial fibrillation (AF) may result from stationary reentry in the left atrium (LA), with fibrillatory conduction toward the right atrium (RA). We hypothesize that periodic input to the RA at an exceedingly high frequency results in disorganized wave propagation, compatible with fibrillatory conduction. Simultaneous endocardial and epicardial optical mapping (di-4-ANEPPS) was performed in isolated, coronary-perfused sheep RA. Rhythmic pacing of Bachmann's bundle allowed well-controlled and realistic conditions for LA-driven RA. Pacing at increasingly higher frequencies (2.0 to 6.0 Hz) led to increasing delays in activation distal to major branching sites of the crista terminalis and pectinate bundles, culminating in spatially distributed intermittent blockade at or above approximately 6.5 Hz. At this "breakdown frequency," the direction of RA propagation became completely variable from beat to beat and thus transformed into fibrillatory conduction. Such frequency-dependent changes were independent of action potential duration. Rather, the spatial boundaries between proximal and distal frequencies correlated well with branch sites of the pectinate musculature. Thus, there exists a breakdown frequency in the sheep RA below which activity is periodic throughout the atrium and above which it is fibrillation-like. The data are consistent with the ideas that during AF, high-frequency activation initiated in the LA undergoes fibrillatory conduction toward the RA, and that sink-to-source effect at branch points of the crista terminalis and pectinate muscles is important in determining the complexity of the arrhythmia.     

Engineering biological structures of prescribed shape using self-assembling multicellular systems

Self-assembly is a fundamental process that drives structural organization in both inanimate and living systems. It is in the course of self-assembly of cells and tissues in early development that the organism and its parts eventually acquire their final shape. Even though developmental patterning through self-assembly is under strict genetic control it is clear that ultimately it is physical mechanisms that bring about the complex structures. Here we show, both experimentally and by using computer simulations, how tissue liquidity can be used to build tissue constructs of prescribed geometry in vitro. Spherical aggregates containing many thousands of cells, which form because of tissue liquidity, were implanted contiguously into biocompatible hydrogels in circular geometry. Depending on the properties of the gel, upon incubation, the aggregates either fused into a toroidal 3D structure or their constituent cells dispersed into the surrounding matrix. The model simulations, which reproduced the experimentally observed shapes, indicate that the control parameter of structure evolution is the aggregate-gel interfacial tension. The model-based analysis also revealed that the observed toroidal structure represents a metastable state of the cellular system, whose lifetime depends on the magnitude of cell-cell and cell-matrix interactions. Thus, these constructs can be made long-lived. We suggest that spherical aggregates composed of organ-specific cells may be used as "bio-ink" in the evolving technology of organ printing.     

Chronic purulent otitis media

This lecture reviews up-to-date information on the classification, etiology, pathogenesis, clinical features, diagnostics, surgical and conservative treatment of chronic purulent otitis media. It is maintained that surgical intervention including sanative and reconstructive procedures as well as hearing improvement measures is currently the preferred approach to the treatment of the disease in question. Special attention is given to different variants of sanative surgery in combination with tympanoplasty. The author emphasizes that the conservative therapy of chronic otitis media has the objective to eliminate exacerbation of the chronic process and does not substitute the surgical treatment.     

Phase II trial of dose-dense doxorubicin plus gemcitabine followed by paclitaxel plus carboplatin in patients with advanced urothelial carcinoma and impaired renal function

BACKGROUND: Cisplatin-based therapy is standard in patients with advanced urothelial carcinoma but a large proportion are ineligible due to renal impairment. The safety and activity of a dose-dense carboplatin-based regimen in this patient population were explored. METHODS: Patients with advanced urothelial carcinoma who were ineligible for cisplatin were eligible based on at least 1 of the following: 1) serum creatinine >1.5 mg/dL; 2) creatinine clearance of >30 mL/min/1.73 m(2) and <60 mL/min/1.73 m(2); and/or 3) prior nephrectomy. Patients received treatment with doxorubicin plus gemcitabine every other week x 5 cycles followed by paclitaxel plus carboplatin weekly x 12 cycles. RESULTS: Twenty-five patients were treated. Myelosuppression was the major toxicity, with 28% of patients experiencing grade 3-4 neutropenia; there were only 2 (8%) episodes of febrile neutropenia. Grade > or = 3 nonhematologic toxicities were infrequent with the exception of grade > or = 3 thrombotic episodes in 4 (16%) patients. There were 5 complete responses and 9 partial responses for an overall response rate of 56% (95% confidence interval [CI]: 35%-76%). The median survival was 15 months (95% CI: 11-30). At a median follow-up for survivors of 45 months, 7 (28%) patients are disease-free. CONCLUSIONS: Dose-dense sequential chemotherapy is tolerable and active in patients with urothelial carcinoma and renal impairment. Prolonged disease-free survival is achievable in a subset of patients with primary unresectable disease or lymph-node only metastases treated with carboplatin-based therapy +/- surgical consolidation. Randomized trials are needed to define the optimal regimen in patients with advanced urothelial carcinoma and renal impairment.     

In Situ Laser-Induced Fabrication of a Ruthenium-Based Microelectrode for Non-Enzymatic Dopamine Sensing

In this paper, we propose a fast and simple approach for the fabrication of the electrocatalytically active ruthenium-containing microstructures using a laser-induced metal deposition technique. The results of scanning electron microscopy and electrical impedance spectroscopy (EIS) demonstrate that the fabricated ruthenium-based microelectrode had a highly developed surface composed of 10 μm pores and 10 nm zigzag cracks. The fabricated material exhibited excellent electrochemical properties toward non-enzymatic dopamine sensing, including high sensitivity (858.5 and 509.1 μA mM⁻¹ cm⁻²), a low detection limit (0.13 and 0.15 μM), as well as good selectivity and stability.