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K Woodward

Publications and source records attributed to K Woodward.

4 recordsLinked to original sources
PubMed1991

Differential auditory processing continues during sleep.

Auditory evoked potentials (AEPs) were used to examine selective stimulus processing in sleep. In waking, repetitive stimuli generate exogenous P1, N1 and P2 components of the auditory evoked potential (AEP). Deviant stimuli generate endogenous cognitive components including the mismatch negativity (MMN), N2 and P3 components. We examined long-latency auditory evoked potentials elicited by repetitive and deviant stimuli during waking and stage II-IV sleep to assess whether stimulus deviance is detected during sleep. The waking P1, N1b and P2 had maximal amplitudes at fronto-central scalp sites, with additional peaks (N1a, N1c) at temporal sites. Deviant tones generated a frontal maximal MMN, and complex novel tones generated an additional P3 component maximal at centro-parietal sites. During stages II-IV sleep N1a, b, c amplitudes were reduced. During stage II sleep all stimuli generated increased P2 amplitudes and a late negative component (N340). Deviant stimuli generated greater P2 and N340 amplitudes than frequent stimuli in stage II sleep, as well as an additional P420 component. In stage III-IV sleep the P420 was absent and the AEP was dominated by a negativity of long duration whose amplitude increased in response to deviant stimuli. These data indicate that auditory evoked activity changes from wakefulness to sleep. The differential response to deviant sounds observed during waking and all sleep stages supports the theory that selective processing of auditory stimuli persists during sleep.

Adolescent↗
PubMed1987

Diagnosing gonorrhea. A comparison of standard and rapid techniques.

A timely and accurate technique for diagnosing gonorrhea is necessary if prompt therapy is to be instituted. We screened 567 adolescents who presented for routine gynecologic care or for specific gynecologic or urologic problems. Each patient was tested by standard culture, Gonozyme (Abbott Labs), and Gram's stain. One hundred five patients (18.5%) had an ELISA immunoassay or culture evidence of infection. Overall sensitivity was 90% for Gonozyme and 56% for Gram's stain (females 41%, males 94%). Overall specificity was 97% for Gonozyme and 99% for Gram's stain. No increase in sensitivity of either test was found in women with signs of upper genital tract involvement. The predictive value of a negative Gonozyme was 98% and 85% for a positive result compared to Gram's stain values of 99% and 95%, respectively. Overall clinical efficacy was 96% for Gonozyme and 93% for Gram's stain. Gonozyme, although a sensitive and specific test, has a limited role in the diagnosis of gonorrhea. Gram's stain, although more limited in women, may serve as a useful adjunct in diagnosing gonorrhea.

Adolescent↗