Abbie Chapman Johnson

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Eclampsia, defined as unexplained seizure in a woman with preeclampsia, is a life-threatening complication of pregnancy with unclear etiology. Magnesium sulfate (MgSO4) is the leading eclamptic seizure prophylactic, yet its mechanism of action remains unclear. Here, we hypothesized severe preeclampsia is a state of increased seizure susceptibility due to(More)
Rats were exposed to toluene by inhalation (1400 ppm, 16 h/d, 8 days) and sacrificed for morphological investigations at 3 and 5 days after the start of the exposure, and 4 days and 6 weeks after the end of the exposure. The cochleae were removed and prepared for light microscopy and scanning electron microscopy. After 3 days of toluene exposure no loss of(More)
The effects of chronic toluene exposure on central neurons were examined using syngeneic grafts into the anterior chamber of the eye. Young adult albino rats with intraocular brain transplants inhaled toluene (1000 ppm) for 9 weeks starting at the time of transplantation, or from Week 8 to 17 after the graft was placed in oculo. Control animals were exposed(More)
Toluene is a widely used organic solvent causing loss of auditory sensitivity in rats and presumably in humans. Also, the hearing loss in humans occupationally exposed to noise has been reported to be aggravated by simultaneous exposure to solvents. The aim of the present investigation was to study the effects of toluene, alone or in combination with other(More)
Rats were exposed to toluene (1000 ppm, 16 h/d, 5 d/w, 2 w), or noise (100 dB Leq, 10 h/d, 7 d/w, 4 w) or toluene followed by noise. Auditory function was tested by brainstem audiometry using a 1/3 octave filtered sine wave stimulus at the frequencies 1.6, 3.15, 6.3, 12.5 and 20.0 kHz. A high-frequency auditory impairment was observed after exposure to(More)
Rats were exposed to noise (100 dB Leq, 10 h/d, 7 d/w, 4 w), or to toluene (1,000 ppm, 16 h/d, 7 d/w, 2 w), or to noise followed by toluene. Auditory sensitivity was tested before exposure, and 1 to 4 weeks after exposure, by brainstem audiometry using a 1/3-octave filtered sine wave stimulus at the frequencies 1.6, 3.15, 6.3, 12.5 and 20.0 kHz. Some(More)
Rats were exposed to toluene by inhalation (1400 ppm, 16 h/d, 8 days) and the auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOEs) were used as measures of the auditory sensitivity. These measurements were made before the exposure to toluene, 3 and 5 days after the start of the exposure and 4 days after the end of the(More)
Pigmented rats were exposed to toluene (1000 ppm, 21 h/day) for 6 or 11 weeks. The function of the vestibulo- and opto-oculomotor systems was tested one month after the end of the exposure by recording of nystagmus, induced by vestibular or optokinetic stimuli. The eye movements were recorded by a magnetic search coil technique. The optokinetic gain in the(More)
Eclampsia, clinically defined as unexplained seizure in a woman with preeclampsia, is a life threatening complication unique to the pregnant state. However, a subpopulation of women with seemingly uncomplicated pregnancies experience de novo seizure without preeclamptic signs or symptoms, suggesting pregnancy alone may predispose the brain to seizure. Here,(More)
Male pigmented rats (n = 36) were exposed to toluene and/or ethanol (1000 p.p.m. toluene in the inhaled air 21 hr/day, and 5.7-8.0% ethanol in the drinking water continuously) during 8 weeks. Electrophysiological recordings were made 1 week after the exposure. Auditory sensitivity (auditory brainstem response) was reduced only after exposures including(More)