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Biomedical subjects

A Penne

Publications and source records attributed to A Penne.

6 recordsLinked to original sources

Medical treatment of senile cataract: clinical investigation of bendazac-lysine using objective and subjective methods.

A modified Zeiss slit lamp coupled with a digital image-processing system was used to evaluate objectively changes in lens transparency over 1 year at 4-month intervals in 150 eyes of 92 patients affected by early senile cataract. A total of 59 patients were treated daily with 1.5 g bendazac-lysine, and 33 patients constituted the control group. At follow-up, visual acuity was also tested using Snellen letter charts at variable contrast to provide an additional parameter closer to traditional methods. Results indicate that the minimal angle of resolution at 10% contrast (MAR10) and the mean gray-level value of the lens image obtained by retroillumination (MLR) are sensitive to early changes in lens transparency. Using MAR10 as a parameter, the control group showed a significant, progressive worsening of the lens status over 12 months, whereas the treated group exhibited no significant changes. MRL indicated the same behaviour as MAR10, although lens damage was detected later in the control group. The results show that bendazac-lysine may delay the formation of lens opacities.

Aged

Incremental binocular amplitude of the pattern visual evoked potential during the first five months of life: electrophysiological evidence of the development of binocularity.

The amplitude of the pattern visual evoked potential (VEP) of a binocular stimulus has been shown to be generally larger than the VEP obtained monocularly. There is evidence that this effect can be considered an electrophysiological index of fusion. To study how binocular vision develops in infancy we evaluated the incremental binocular amplitude (IBA) in three infants in a longitudinal investigation during the first five months of life. The stimuli were phase-alternating square-wave gratings with spatial and temporal parameters chosen to be appropriate for neonates. IBA was defined as the percentage increment of the largest binocular response compared with the monocular response. In the first two months of life IBA values were near zero, that is, no summation occurred. Between the second and third month IBA values rose markedly and after the third month its value was greater than 100%, demonstrating binocular facilitation. Thus in the first two months of life the eyes do not seem to cooperate as in adults. By the second and third month the binocular pattern VEP reflects an increasing binocular interaction. Other studies of the development of stereopsis have also found evidence of binocularity at similar ages.

Aging

Neurophysiological and CSF immunological study of 19 patients affected by acute idiopatic optic neuritis.

We studied 19 patients affected by acute idiopatic optic neuritis (ON), with neurophysiological tests: visual (VEP), somatosensory (SSEP), acoustic (ABR) evoked potentials and study of the blink reflex (BR), and with cerebrospinal fluid (CSF) examination, in order to detect "silent" lesions in the central nervous system (CNS) and/or immunological alterations, suggestive of multiple sclerosis (MS). The percentage of cases with at least one altered CSF IgG parameter (IgG index, IgG synthesis/day and IgG oligoclonal bands) has been higher than that of cases with one or more altered neurophysiological tests, regardless of the apparently intact eye VEP. If we also included this last test, the 2 percentages become identical. The validity of these tests in predicting the evolution of ON in MS is discussed.

Acute Disease

Evidence that 2-phenylpyrazolo[4,3-c]-quinolin-3(5H)-one antagonises pharmacological, electrophysiological and biochemical effects of diazepam in rats.

The effects of the acute administration of 2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one on diazepam-induced behaviour and electrophysiological activity were studied in rat. The compound, in doses of 5-10 mg/kg (i.p.), which per se did not induce alterations in spontaneous locomotor activity, antagonised the sedative effect induced by 5-10 mg/kg (i.p.) of diazepam. The injection of diazepam in rats, induced a profound reduction in the first negative wave of the recording of the visual evoked potential used as a sensitive electrophysiological test, in vivo. 2-Phenylpyrazolo[4,3-c]quinolin-3(5H)-one (10 mg/kg, i.p.) caused a recovery of the amplitude of the first negative wave within a few minutes. This result was confirmed by the finding that 2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one, injected acutely in rats, pretreated with diazepam exhibited the capacity to antagonise the binding of [3H]diazepam determined in vitro on synaptic membrane preparations from cortex. The comparison of the pattern of the visual-evoked potential, recorded after the injection of 2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one (50 mg/kg) with the patterns recorded after the injection of ethyl-8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazolo(1,5a) (1,4)benzodiazepine-3-carboxylate (50 mg/kg) and ethyl-beta-carboline-3-carboxylate and 1-methyl-beta-carboline demonstrated that 2-phenylpyrazolo[4,3-c]quinolin-3(5H)-one is devoid of intrinsic activity.

Animals

Pattern reversal visually evoked potentials in general anesthesia.

Various authors have tried to determine visual acuity both electrophysiologically (Sokol, 1976 and 1978; Marg et al., 1976; Maffei and Fiorentini, 1977) and with psychophysical methods (Teller et al., 1974; Banks and Salapatek, 1976; Atkinson et al., 1976) in awake children. Our experiments try to verify the possibility of assessing visual acuity in children under Ethrane anesthesia. We conclude that under Ethrane anesthesia VEPs produced by phase-alternating square-wave gratings do not allow a fine assessment of visual acuity. Gross indications of visual acuity can however be obtained.

Adolescent