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Biomedical subjects

I Behar

Publications and source records attributed to I Behar.

11 recordsLinked to original sources
PubMed1992

The effects of pyridostigmine bromide on visual performance.

The effects of pyridostigmine bromide (PB) on selected visual functions were measured on four healthy aviator candidates. Following a pretreatment day during which baseline measurements were completed, subjects were administered currently recommended doses (30 mg, t.i.d.) of PB for 3 d during which their visual functions were assessed using a repeated measures design. Spatial resolution ability was evaluated with high and low contrast visual acuity charts and contrast sensitivity charts at three luminance levels. Dark adaptation was evaluated by measuring visual thresholds for 40 min after a standardized retinal photopigment bleach. Also, refractive error and several oculomotor functions (lateral phoria, fusional vergence, accommodative amplitude, and pupil size) were measured. On days that the subjects ingested PB, only refractive error and pupil diameter were significantly different, and these only minimally. We conclude that the use of PB at doctrinal doses will not significantly compromise an aviator's visual ability.

Accommodation, Ocular↗
PubMed1987

The effect of cycloplegia on the visual contrast sensitivity function.

Contrast sensitivity assessment is one of several emergent techniques being considered for inclusion in a visual standards test battery for the Army, particularly for the evaluation of Army aviators. Since a cycloplegic refraction is required for initial selection of candidates for Class I and Class IA flying duty, it is important to determine what effect, if any, cycloplegia has on the contrast sensitivity function. There were 12 subjects tested, all officers in preparation for flight training who had passed a recent Class I flight physical. Contrast sensitivity functions were obtained under normal ambient conditions and in the presence of a glare source both under manifest and cycloplegic conditions. Cycloplegia produced a small reduction in contrast sensitivity under normal ambient conditions, and a greater reduction under glare conditions. For both conditions, the cycloplegia effect was greater for the higher spatial frequency gratings than for the lower.

Aerospace Medicine↗
PubMed1985

[Chemical composition and biological properties of Erythraea centaurium Rafn].

The steroidic fraction from the ethereal extract of the aereal parts of Erythraea centaurium Rafn. has showed the presence of the following sterols: beta-sitosterol, stigmasterol, campesterol, brassicasterol and delta 7 stigmastenol, isolated by H.P.L.C. and identified by G.L.C., 1H-N.M.R. and MS. Then the free amino-acids from the aqueous extract of E. centaurium were determined.

Amino Acids↗
PubMed1984

Steroidal glycosides of Tamus communis.

From the rhizomes of T. Communis two steroidal glycosides were isolated and identified as dioscin [diosgenin bis-alpha-L-rhamnopyranosyl (1----2 and 1----4) -beta-D-glucopyranoside] and gracillin [diosgenin-alpha-L-rhamnopyranosyl (1----2)-beta-D-glucopyranosyl (1----3)-beta-D-glucopyranoside] by 1H and 13C NMR spectroscopy, MS (FAB) and chemical evidences. It is interesting to note that this is the first report of the occurrence of dioscin and gracillin in the rhizomes of T. communis.

Diosgenin↗