Chemical RNA labeling without 3' end bias using fluorescent cis-platin compounds.

Recently, fluorescent, monofunctional cis-platin derivatives have been developed to chemically label nucleic acids for use in fluorescent hybridization assays. Here we show by hybridizations to microarrays containing oligonucleotide probes for the 3' ends, middle parts, and 5' ends of mRNAs, that this labeling methodology bypasses the problem of the 3' end bias that is characteristic of the conventional enzymatic oligo(dT)-primed, reverse transcription labeling of mRNAs.

Effect of periodontal treatment on the activity of chitinase in whole saliva of periodontitis patients.

Human salivary chitinase could play a role in the defence against chitin-containing oral pathogens. The activity levels of chitinase in the whole saliva of periodontitis patients were significantly higher than those in saliva from controls. Periodontal treatment for a period of 5-6 months resulted in a three- to fourfold decrease in this enzyme activity. The activity of beta-N-acetylhexosaminidase, which is another enzyme that hydrolyses glycosidic linkages, also decreased as a result of treatment, although to a lesser extent. The decrease in chitinase activity upon treatment of the disease did not correlate with the decrease that was seen in clinical attachment loss and bleeding on probing, and only a weak correlation was observed with the changes in probing pocket depth and plaque index. No correlations were found between the above clinical parameters and the decrease in beta-N-acetylhexosaminidase activity.

Chitinase in whole and glandular human salivas and in whole saliva of patients with periodontal inflammation.

In recent studies the existence of a chitinase in various mammals, like man, was described. The aim of the present study was to find out whether salivas of periodontally healthy and inflamed humans also contain chitinase activity. Chitinase activity, assayed with the substrate 4-methylumbelliferyl-beta-D-N,N',N"-triacetylchitotrioside, was shown to be present in human whole saliva, with an activity level and apparent molecular mass (35 kDa) that were comparable with those of the human serum enzyme. Both lysozyme and beta-N-acetylhexosaminidase could be separated from chitinase by means of Bio-Gel P-100 gel filtration chromatography. The enzyme was also present in glandular saliva of parotid, palatine, submandibular and sublingual glands. The chitinase activity was not of oral epithelial, bacterial or plaque bacterial origin and was not correlated with the activity of salivary amylase. A comparative study of whole salivas of periodontally healthy controls and gingivitis and periodontitis subjects showed that only in the case of periodontitis there was a significant increase of the specific chitinase activity. The latter enzyme showed a gel filtration pattern that was comparable with that of the enzyme from controls. The measured albumin levels in saliva and the absence of correlation between the chitinase activity levels in plasma and saliva from periodontitis patients indicated that the (increased) chitinase activities did not originate from blood leakage to the oral cavity.