Genetic variation in 16S-23S rDNA internal transcribed spacer regions and the possible use of this genetic variation for molecular diagnosis of Bacteroides species.

The structural variation in 16S-23S rDNA internal transcribed spacer regions (ITS) among Bacteroides species was assessed by PCR amplification and sequencing analysis, and its possible use for molecular diagnosis of these species was evaluated. Ninety strains of the genus Bacteroides, including the species B. distasonis, B. eggerthii, B. fragilis, B. ovatus, B. thetaiotaomicron, B. uniformis and B. vulgatus, produced one to three ITS amplification products with sizes ranging from 615 to 810 bp. Some Bacteroides strains could be differentiated at species level on the basis of ITS amplification patterns and restriction fragment length polymorphism (RFLP) analysis using a four-nucleotide-recognizing enzyme, Msp I. The results of sequence analysis of ITS amplification products revealed genes for Ile-tRNA and Ala-tRNA in all strains tested. The nucleotide sequence, except for that in tRNA-coding regions, was highly variable and characteristic for each species, but a common sequence among B. fragilis, B. thetaiotaomicron and B. ovatus was observed. A digoxigenin-labeled oligonucleotide probe (named FOT1), which was designed from this conserved sequence, specifically hybridized to the ITS amplification products from B. fragilis, B. thetaiotaomicron and B. ovatus. These results suggest that the ITS region is a useful target for the development of rapid and accurate techniques for identification of Bacteroides species.

Prevention of cystoid macular edema after lens extraction by topical indomethacin (III) radioimmunoassay measurement of prostaglandins in the aqueous during and after lens extraction procedures.

The amounts of Prostaglandin (PG) E and F2alpha in the aqueous humor were measured by radioimmunoassay techniques before and immediately after intracapsular and extracapsular cataract extractions. We found that: 1. The levels of PG E and PG F2alpha are elevated by cataract extraction. 2. The elevated levels of PGs can all be prevented by preoperative applications of topical indomethacin. 3. No differences in the amounts of PGs biosynthesized during intracapsular and extracapsular lens extraction were found. 4. In some cases, the levels of PG E were still elevated one week after surgery. These findings were used as the basis for our attempts to define the causes of cystoid macular edema (CME) following lens extractions.

Prostaglandins released into human burn blister fluid.

Acidic lipids were isolated from human burn blister fluid and the presence of prostaglandins E and F compounds was demonstrated by the thin-layer chromatography. Prostaglandins E1, E2 and F2alpha were identified and quantitatively determined by radioimmunoassay and by gas-liquid chromatography/mass spectrometry. Analyses on burn blister fluid obtained from 35 patients with skin burn indicated an extensive release of prostaglandins into the blister after burn injury in a few hours. The high levels of prostaglandins in burn blister fluid decreased gradually during 24 hours after burn.