Measurement of the small-signal gain and saturation intensity of a XeF discharge laser.

An optical oscillator-amplifier series driven by a Blumlein discharge has been fabricated and optimized for measuring the small-signal gain and saturation intensity of a XeF (B ? X) laser at 352 nm. Pressure dependence of the gain and the saturation property of the laser have been investigated.

Detection of Mycoplasma pneumoniae-DNA within diseased gingiva by in situ hybridization using a biotin-labeled probe.

Isolation of Mycoplasma pneumoniae was accomplished in gingival biopsies of four patients exhibiting chronic inflammatory periodontal disease using in situ hybridization with biotin-labeled DNA probes. The distribution of the M. pneumoniae organisms was mainly cytoplasmic and evenly spread around the nuclei of connective tissue cells. Controls of nondisease sites in the same patients showed no infection with M. pneumoniae. Since M. pneumoniae is the only Mycoplasma known to be pathogenic, their role in the pathogenesis of periodontal disease needs further study.