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Biomedical subjects

R Montemayor

Publications and source records attributed to R Montemayor.

15 recordsLinked to original sources
PubMed2001

Augmented rod bipolar cell function in partial receptor loss: an ERG study in P23H rhodopsin transgenic and aging normal rats.

Physiological consequences of early stages of photoreceptor degeneration were examined in heterozygous P23H rhodopsin transgenic (Tg) and in aging normal Sprague-Dawley rats. Rod photoreceptor and rod bipolar (RB) cell function were estimated with maximum value and sensitivity parameters of P3 and P2 components of the electroretinogram. In both Tg and aging normal rats, the age-related rate of decline of P3 amplitude was steeper than that of the P2 amplitude. Tg rats showed greater than normal sensitivity of the rods. A new model of distal RB pathway connectivity suggested photoreceptor loss could not be the sole cause of physiological abnormalities; there was an additional increase of post-receptoral sensitivity. We propose that changes at rod-RB synapses compensate for the partial loss of rod photoreceptors in senescence and in early stages of retinal degeneration.

Aging↗
PubMed1997

[Severe syndrome of ovarian hyperstimulation. Incidence, value of criteria of risk factors and preventive methods].

Statistical analysis; square Chi test, Pearson, were practiced, from 1994 to 1996. There were 368 hyperstimulated cycles; three SHOS cases without risk factors and 28 cases with risk factors without SHOS. Risk factors presented were: average seric estradiol 6643.59 +/- 2320 pg/ ml; average follicles: 26.6 +/- 6.9; ovules recuperated by aspiration: 19.32 +/- 9.1. There were five groups according to preventive methods: albumin (13 patients, coasting (one patient); albumin-coasting (11 pacientes); albumin-embryo freezing (3 patients); embryo freezing (one patient). None of the patients presented SHOS.

Analysis of Variance↗
PubMed1995

Effects of mellow and frenetic music and stimulating and relaxing scents on walking by seniors.

Previous research has yielded an inconclusive picture of the effects of music and scent on walking. Few laboratory studies have detected a beneficial effect of music; olfactory research has shown performance is positively affected for repetitive tasks but not yet on walking. The influence of these two types of stimuli in efficiency of exercise among seniors was assessed by measuring distance walked on an indoor course. Using a 3 x 3 factorial design [mellow music in 4:4 time, frenetic music in 2:8 time, and white noise by stimulating, relaxing, and control scent conditions], each of 20 volunteers from a senior center received nine randomized, 90-sec. exercise trials. Walking distance was reduced by mellow music but unaffected by stimulating music; there was no effect of scent.

Aged↗
PubMed1994

Mellow and frenetic antecedent music during athletic performance of children, adults, and seniors.

Previous research has yielded a contradictory picture of the effects of music on athletic performance. While athletes frequently report using music while training or during or before an event, laboratory studies have generally not detected a beneficial effect of music. The influence of music, judged mellow and frenetic, played before exercise was assessed by measuring stationary bicycle mileage. 60 volunteers from three age groups (child, adult, and senior) and with two levels of prior activity (high and low) were subjects. Each participant received three randomized 2-min. exercise trials, each preceded by 1-min. exposure to mellow music, frenetic music, or white noise. Mileage in both music conditions was significantly higher than that during the white-noise control trial except among the senior subjects. No significant differences between frenetic and mellow music were noted.

Adolescent↗
PubMedDate not supplied

Anatomical study of the blood supply to the skin in rhytidectomy.

This study was undertaken to evaluate the blood supply to the facelift flap by identifying the perforating arteries in the anterior facial region, which is preserved during the undermining of the flap. We have called this medial zone the pedicle area of the flap. Eleven pairs of musculocutaneous perforator arteries supplying the facelift flap were identified, all of them emerging from three main arterial trunks: the facial, the superficial temporal, and the ophthalmic arteries. A rich anastomotic network connected all the vessels; however, we were able to group this network into five basic forms including the ipsilateral and contralateral external and internal carotid arteries. We found these anastomotic links to be constant. We propose that this anatomical feature of the face provides for adequate blood supply even when certain regions have been altered by previous dissection, injury, or congenital deformity. This study confirms previous anatomical findings but also adds specific information regarding the blood supply to the facelift flap that will allow this procedure to be carried out with maximum safety and effectiveness.

Arteries↗