Light-induced trigeminal sensitization without central visual pathways: another mechanism for photophobia.

PURPOSE: The authors investigated whether trigeminal sensitization occurs in response to bright light with the retina disconnected from the rest of the central nervous system by optic nerve section. METHODS: In urethane-anesthetized rats, trigeminal reflex blinks were evoked with air puff stimuli directed at the cornea in darkness and at three different light intensities. After normative data were collected, the optic nerve was lesioned and the rats were retested. In an alert rat, reflex blinks were evoked by stimulation of the supraorbital branch of the trigeminal nerve in the dark and in the light. RESULTS: A 9.1 × 10(3) µW/cm(2) and a 15.1 × 10(3) µW/cm(2) light significantly enhanced the magnitude of reflex blinks relative to blinks evoked by the same trigeminal stimulus when the rats were in the dark. In addition, rats exhibited a significant increase in spontaneous blinking in the light relative to the blink rate in darkness. After lesioning of the optic nerve, the 15.1 × 10(3) µW/cm(2) light still significantly increased the magnitude of trigeminal reflex blinks. CONCLUSIONS: Bright lights increase trigeminal reflex blink amplitude and the rate of spontaneous blinking in rodents. Light can modify trigeminal activity without involving the central visual system.

Women's opinions about routine HIV testing during pregnancy: implications for the opt-out approach.

The 1995 United States Public Health Service (USPHS) recommendation regarding HIV testing for pregnant women was revised in 2003 calling for routine HIV testing for pregnant women with patient notification. Routine testing (opt-out screening) offers women the opportunity to decline HIV testing but eliminates the requirement of pretest counseling and separate written consent. To assess women's opinions about the opt-out approach to HIV testing during pregnancy, a cross-sectional survey was conducted in May-June 2004 at 14 geographically diverse clinics funded by Ryan White CARE Act (RWCA) Part C and Part D agreements. Of 853 women respondents to the one-page, self-completed survey questionnaire, 90% agreed with routine HIV testing and 91% reported being comfortable with testing, demonstrating that the large majority of women agree with and support HIV testing as a part of routine prenatal care. Women's opinions were associated with HIV testing status, e.g., 76% of women who had never been tested for HIV thought HIV testing should be part of a routine pregnancy check-up as compared with women who were HIV-negative (93%) or HIV-positive (90%) (chi(2) = 31.3943, p < 0.0001). Comfort with HIV testing was associated with higher HIV knowledge. Approximately half of the respondents indicated that HIV tests are different from other tests and that women need more information prior to testing. Results demonstrated clear consensus in support of routine testing. Increased efforts to disseminate resources to providers coupled with providers' effective communication of information to pregnant women can build on the support that women have conveyed for HIV testing during pregnancy.