SAR study of 4-arylazo-3,5-diamino-1-pyrazoles: identification of small molecules that induce dispersal of biofilms.

By screening of a collection of 50 000 small-molecule compounds, we recently identified 4-arylazo-3,5-diamino-1-pyrazoles as a novel group of anti-biofilm agents. Here, we report a SAR study based on 60 analogues by examining ways in which the pharmacophore can be further optimized, for example, substitutions in the aryl ring. The SAR study revealed the very potent anti-biofilm compound 4-(2-(2-fluorophenyl)hydrazineylidene)-5-imino-4,5-dihydro-1-pyrazol-3-amine ().

Interfacial electrochemical electron transfer processes in bacterial biofilm environments on Au(111).

We have studied Streptococcus mutans (S. mutans) biofilm growth and growth inhibition on Au(111)-surfaces using atomic force microscopy (AFM) and interfacial electrochemistry of a number of redox probe molecules. AFM of the biofilm growth and growth inhibition on both mica and Au(111)-surfaces was followed by sampling at given times, drying the samples naturally, and imaging.

Comparison of computational methods for the identification of cell cycle-regulated genes.

Motivation: DNA microarrays have been used extensively to study the cell cycle transcription programme in a number of model organisms. The Saccharomyces cerevisiae data in particular have been subjected to a wide range of bioinformatics analysis methods, aimed at identifying the correct and complete set of periodically expressed genes.

Results: Here, we provide the first thorough benchmark of such methods, surprisingly revealing that most new and more mathematically advanced methods actually perform worse than the analysis published with the original microarray data sets.

Coronavirus 3CLpro proteinase cleavage sites: possible relevance to SARS virus pathology.

Background: Despite the passing of more than a year since the first outbreak of Severe Acute Respiratory Syndrome (SARS), efficient counter-measures are still few and many believe that reappearance of SARS, or a similar disease caused by a coronavirus, is not unlikely. For other virus families like the picornaviruses it is known that pathology is related to proteolytic cleavage of host proteins by viral proteinases. Furthermore, several studies indicate that virus proliferation can be arrested using specific proteinase inhibitors supporting the belief that proteinases are indeed important during infection.

Physiological responses of KT2442 to phosphate starvation.

The physiological responses of KT2442 to phosphate starvation were examined with respect to cell morphology, qualitative demonstration of the accumulation of the intracellular storage component poly-3-hydroxyalkanoate (PHA), cellular ATP and ribosome content, and the rate of total protein synthesis. Upon prolonged incubation under phosphate-limiting conditions, the number of viable cells decreased by two to three orders of magnitude during the first 3 weeks. However, after this decline, viability of the cultures remained remarkably constant for many weeks.