Streptococcus salivarius is an early colonizer of human oral and nasopharyngeal epithelia, and strain K12 has reported probiotic effects. An emerging paradigm indicates that commensal bacteria downregulate immune responses through the action on NF-kappaB signaling pathways, but additional mechanisms underlying probiotic actions are not well understood. Our objective here was to identify host ge...

PURPOSE The aim of this study was to develop a validated, reliable, and minimally invasive technique for diagnosing limbal stem cell deficiency (LSCD) by immunocytochemical detection of conjunctival and corneal keratins on epithelial cells collected by impression cytology (IC). METHODS After validation of labeling techniques on a cohort of 10 healthy control patients, keratins K12, K13, and K...

AIMS To determine whether dosing with bacteriocin-producing Streptococcus salivarius following an antimicrobial mouthwash effects a change in oral malodour parameters and in the composition of the oral microbiota of subjects with halitosis. MATERIALS AND RESULTS Twenty-three subjects with halitosis undertook a 3-day regimen of chlorhexidine (CHX) mouth rinsing, followed at intervals by the us...

Tumor cells expressing the herpes simplex virus type 1 thymidine kinase (HSV-tk) gene are killed by nucleoside analogues such as ganciclovir (GCV). GCV affects not only the cells expressing HSV-tk but also neighboring cells that do not express the gene; this phenomenon commonly is called "bystander effect." GCV metabolites transfer via gap junctional intercellular communication (GJIC) accounts ...

As the first stage in investigating the genetic basis of natural variation in Escherichia coli, the gene(s) conferring the ability to use sucrose as a carbon and energy source (given the symbol sac+) was transferred from a wild strain to K12, which does not use sucrose. The sac+ region was transferred by two different methods. On both occasions it took a chromosomal location at minute 50.5 on t...

PURPOSE To evaluate the expression patterns of cytokeratin (K) 12, 13, and 19 in normal epithelium of the human ocular surface to determine whether K13 could be used as a marker for conjunctival epithelium. METHODS Total RNA was isolated from the human conjunctiva and central cornea. Those transcripts that had threefolds or higher expression levels in the conjunctiva than the cornea were iden...

There exists extensive evidence that people learn positively about themselves. We build on this finding to develop a model of team formation in the workplace. We show that learning positively about oneself systematically undermines the formation of teams. Agents becoming overconfident tend to ask for an excessive share of the group outcome. Positive learning generates divergence in workers' bel...

In this review, most of the information presented will be derived from studies with Escherichia coli K-12 (E. coli) and its related bacteriophages, simply because more is known about methylation in these organisms than in any other. The two methylated bases that have been detected in E. coli are 6-methyladenine (6-meAde) and 5-methylcytosine (7, 18). Since little is known about the biological f...

This study of galactose-induced galactose transport in Escherichia coli K12 showed that in most strains two transport systems having the properties of “galactose permease” and “P-methyl galactoside permease” are responsible for the observed transport. Several strains contain only the galactose transport system but still grow normally on galactose. The regulation of this system was shown to be v...

A rapid and efficient method for plasmid transformation of Klebsiella pneumoniae M5a1 and Escherichia coli K12 has been developed. The method, which uses a freeze-thaw cycle in the presence of CaCl2 to facilitate DNA uptake, is substantially more efficient for K. pneumoniae M5a1 than the conventional transformation procedure for E. coli. The simplicity and speed of the method makes it very attr...