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Biomedical subjects

S Telles

Publications and source records attributed to S Telles.

At least 19 recordsLinked to original sources
PubMed2001

Improved performance in the Tower of London test following yoga.

Twenty girls between 10 and 13 years of age, studying at a residential school were randomly assigned to two groups. One group practiced yoga for one hour fifteen minutes per day, 7 days a week, while the other group was given physical training for the same time. Time for planning and for execution and the number of moves required to complete the Tower of London task were assessed for both groups at the beginning and end of a month. These three assessments were separately tested in increasingly complex tasks requiring 2-moves, 4-moves and 5-moves. The pre-post data were compared using the Wilcoxon paired signed ranks test. The yoga group showed a significant reduction in planning time for both 2-moves and 4-moves tasks (53.9 and 59.1 percent respectively), execution time in both 4-moves and 5-moves tasks (63.7 and 60.3 percent respectively), and in the number of moves in the 4-moves tasks (20.9 percent). The physical training group showed no change. Hence yoga training for a month reduced the planning and execution time in simple (2-moves) as well as complex tasks (4, 5-moves) and facilitated reaching the target with a smaller number of moves in a complex task (4-moves).

Child↗
PubMed2001

Improvement in hand grip strength in normal volunteers and rheumatoid arthritis patients following yoga training.

The present study aimed at assessing the effects of a set of yoga practices on normal adults (n = 37), children (n = 86), and patients with rheumatoid arthritis (n = 20). An equal number of normal adults, children, and patients with rheumatoid arthritis who did not practice yoga were studied under each category, forming respective control groups. Yoga and control group subjects were assessed at baseline and after varying intervals, as follows, adults after 30 days, children after 10 days and patients after 15 days, based on the duration of the yoga program, which they attended, which was already fixed. Hand grip strength of both hands, measured with a grip dynamometer, increased in normal adults and children, and in rheumatoid arthritis patients, following yoga, but not in the corresponding control groups, showing no re-test effect. Adult female volunteers and patients showed a greater percentage improvement than corresponding adult males. This gender-based difference was not observed in children. Hence yoga practice improves hand grip strength in normal persons and in patients with rheumatoid arthritis, though the magnitude of improvement varies with factors such as gender and age.

Adolescent↗
PubMed2000

Oxygen consumption and respiration following two yoga relaxation techniques.

The present study was conducted to evaluate a statement in ancient yoga texts that suggests that a combination of both "calming" and "stimulating" measures may be especially helpful in reaching a state of mental equilibrium. Two yoga practices, one combining "calming and stimulating" measures (cyclic meditation) and the other, a "calming" technique (shavasan), were compared. The oxygen consumption, breath rate, and breath volume of 40 male volunteers (group mean +/- SD, 27.0 +/- 5.7 years) were assessed before and after sessions of cyclic meditation (CM) and before and after sessions of shavasan (SH). The 2 sessions (CM, SH) were 1 day apart. Cyclic meditation includes the practice of yoga postures interspersed with periods of supine relaxation. During SH the subject lies in a supine position throughout the practice. There was a significant decrease in the amount of oxygen consumed and in breath rate and an increase in breath volume after both types of sessions (2-factor ANOVA, paired t test). However, the magnitude of change on all 3 measures was greater after CM: (1) Oxygen consumption decreased 32.1% after CM compared with 10.1% after SH; (2) breath rate decreased 18.0% after CM and 15.2% after SH; and (3) breath volume increased 28.8% after CM and 15.9% after SH. These results support the idea that a combination of yoga postures interspersed with relaxation reduces arousal more than relaxation alone does.

Adult↗
PubMed2000

A review of mind/body therapies in the treatment of musculoskeletal disorders with implications for the elderly.

BACKGROUND: A comprehensive, but not systematic, review of the research on complementary and alternative treatments, specifically mind/body techniques, on musculoskeletal disease was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and provide a rationale for future research carrying the theme of "successful aging." METHODS: Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet as well as interviews conducted with practitioners and the elderly. Mind/body practices evaluated were: social support, cognitive-behavioral therapy, meditation, the placebo effect, imagery, visualization, spiritual/energy healing, music therapy, hypnosis, yoga, tai chi, and qigong. Studies published after 1990 were the priority, but when more recent literature was scarce, other controlled studies were included. RESULTS: Mind/body techniques were found to be efficacious primarily as complementary treatments for musculoskeletal disease and related disorders. Studies provided evidence for treatment efficacy but most apparent was the need for further controlled research. CONCLUSIONS: Reviewers found a dearth of randomized controlled research conducted in the US. There is a lack of studies with which to determine appropriate dosage and understand the mechanisms by which many of the practices work. Anecdotal evidence, some controlled research, clinical observation, as well as the cost effectiveness and lack of side effects of the mind/body treatments make further investigation a high priority.

Aged↗
PubMed2000

Effect of yoga training on maze learning.

The performance in a maze learning task was assessed in adults of either sex (n = 31) before and after 30 days of yoga training and in an age and gender matched control group of subjects who did not receive training in yoga. Subjects were blind folded and used the dominant hand to trace the path in a wooden pencil maze. At each assessment, subjects were given 5 trials, without a gap between them. Performance was based on the time taken to complete the maze and the number of blind alleys taken. The time and error scores of Trial 1 were significantly less after yoga (two-factor ANOVA, Tukey test). Repeating trials significantly decreased time scores at Trial 5 versus Trial 1, for both groups on Day 1 and for the control group on Day 30. Hence the yoga group showed improved performance in maze tracing at retest 30 days later, which may be related to this group being faster learners and also the effect of yoga itself. Yoga training did not influence maze learning, based on the performance in 5 repeat trials.

Adult↗
PubMed1999

Factors influencing changes in tweezer dexterity scores following yoga training.

Yoga has already been shown to improve perceptual-motor skills, but the factors which influence its effects are not well defined. This study correlates age, gender, and motivation to learn yoga with the performance in a dexterity task following yoga. Tweezer dexterity was recorded in eighty subjects belonging to four groups. Two groups were given a month of yoga training. One group consisted of subjects who had volunteered to join for the training and the other group were deputed for the training as part of their job. The two remaining groups did not receive yoga training and were selected to match the respective groups receiving yoga, for age and sex, but not for their motivation to learn yoga. The test involved using a tweezer to place metal pins in evenly spaced holes in a metal plate within four minutes. Following yoga the scores of the volunteers who learnt yoga increased significantly, whereas there was no change in scores of deputed subjects and non-yoga groups. For reasons described in detail, factors such as age and gender did not appear to contribute to the difference in performance. Hence motivation to learn yoga appeared to influence the magnitude of increase.

Adult↗
PubMed1999

Yoga training and motor speed based on a finger tapping task.

A finger tapping task was used to assess motor speed (MS) of both hands in 53 adults and 152 children before and after yoga training and in 38 adults of a non-yoga (control) group. All subjects were right hand dominant. The 30-second tapping speed (TS) test was considered as three time intervals, i.e. 0-10 second (TS1), 10-20 seconds (TS2) and 20-30 seconds (TS3). There was a significant (Student's t-test) increase in all three TS values following 10 days of yoga in children and 30 days of yoga in adults. However for both groups at baseline and final assessments, TS2 and TS3 were significantly lower than TS1. Hence the TS was increased after yoga training during the first 10-seconds of the test but not during the next 20 seconds. These results suggest an increase in motor speed for repetitive finger movements following yoga training, but not in strength or endurance, as the increase was not sustained over 30 sec.

Adolescent↗
PubMed1999

Sudomotor sympathetic hypofunction in Down's syndrome.

General sympathetic dysfunction has been proposed as an explanation for the inability to reach normal heightened attention in Down's syndrome (DS). The present study on 15 DS subjects (group average age +/- SD, 14.3 +/- 3.6 years; 11 males) and in an equal number of age- and gender-matched normal subjects (NS), evaluated activity in different subdivisions of the sympathetic nervous system. DS subjects had (i) lower skin conductance levels (i.e., lower sudomotor sympathetic activity) and (ii) higher heart rates than NS. In response to auditory stimuli, DS subjects showed abnormal SSR responses (also indicating sudomotor sympathetic activity) but normal cutaneous vasoconstriction. Hence the results suggest that sympathetic dysfunction in DS is restricted to the sudomotor subdivision, activity of which has been associated with attention and recognition.

Adolescent↗
PubMed1998

Zinc diffusion through lipid bilayers.

Zinc diffusion across liposome bilayers was measured for a set of phosphatidylcholines. These lipids were sonicated to form small unilamellar vesicles in the presence of the metallochromic indicator antipyrylazo III. This chelator sequentially forms two complexes with zinc ion. The rate constant for the first complex formation is shown to increase linearly with zinc concentration. The slope of this line, a [Zn2+]-independent, second-order rate constant, varies with changes in phosphatidylcholine properties. The rate constant is little affected by changes in fluidity as estimated from the reduced temperature [Tr = (Texperimental-Tc)/Tc]. In contrast, the rate constant is directly dependent on lipid oxidation as measured by either a thiobarbituric acid test or a spectrophotometric determination of conjugate dienes. We estimate that zinc diffusion stimulated by lipid oxidation can approach rates observed in hepatocyte zinc transport.

Coloring Agents↗
PubMed1998

Differences between congenitally blind and normally sighted subjects in the P1 component of middle latency auditory evoked potentials.

Auditory evoked potentials (0 to 100 msec. range) were recorded two times for 9 congenitally blind children (age = 14.1 yr. +/- 1.4 yr) and 9 age-matched children with normal vision. The groups' peak latency and amplitude of the P1 wave were compared. The peak latency was significantly lower for the congenitally blind than for the normally sighted on a two-factor analysis of variance. Since the P1 wave is thought to correspond to either the ascending reticular activating system or the primary auditory cortex, these results suggest that information processing at these neural levels may occur more efficiently in the blind.

Analysis of Variance↗
PubMed1998

Shorter latencies of components of middle latency auditory evoked potentials in congenitally blind compared to normal sighted subjects.

A previous study which reported shorter latencies of the Nb component of AEP-MLRs in congenitally blind compared to normal sighted subjects, formed the basis for the present study. The blind subjects had received a rehabilitation program from the age of 4 years onwards, which may have influenced auditory function. Hence the present study was designed to compare the AEP MLRs of normal sighted subjects with age-matched blind subjects who had not undergone early rehabilitation. Auditory evoked potentials (0 to 100 ms. range) were recorded in 10 congenitally blind subjects (average age = 22.4 +/- 4.9 yrs.) and an equal number of age-matched subjects with normal vision. There were two repetitions per subject. The peak latencies of both the Pa (maximum positive peak between Na and 35 ms.) and Nb (maximum negative peak between 38 and 52 ms.) waves was significantly shorter in congenitally blind compared to normal sighted subjects. Since the Pa and Nb waves are believed to be generated by the superior temporal cortex (Heschl's gyrus), it appears that processing at this neural level occurs more efficiently in the blind. Also, in spite of the absence of an early rehabilitation program the present subjects showed the same auditory changes as those reported earlier.

Adaptation, Physiological↗
PubMed1998

Effect of two selected yogic breathing techniques of heart rate variability.

The heart rate variability (HRV) is an indicator of the cardiac autonomic control. Two spectral components are usually recorded, viz. high frequency (0.15-0.50 Hz), which is due to vagal efferent activity and a low frequency component (0.05-0.15 Hz), due to sympathetic activity. The present study was conducted to study the HRV in two yoga practices which have been previously reported to have opposite effects, viz, sympathetic stimulation (kapalabhati, breathing at high frequency, i.e., 2.0 Hz) and reduced sympathetic activity (nadisuddhi, alternate nostril breathing). Twelve male volunteers (age range, 21 to 33 years) were assessed before and after each practice on separate days. The electrocardiogram (lead I) was digitized on-line and off-line analysis was done. The results showed a significant increase in low frequency (LF) power and LF/HF ratio while high frequency (HF) power was significantly lower following kapalabhati. There were no significant changes following nadisuddhi. The results suggest that kapalabhati modifies the autonomic status by increasing sympathetic activity with reduced vagal activity. The study also suggests that HRV is a more useful psychophysiological measure than heart rate alone.

Adult↗
PubMed1998

Autonomic changes while mentally repeating two syllables--one meaningful and the other neutral.

Autonomic and respiratory variables were recorded in 12 volunteers in three types of sessions (1). Before, during and after a test period of mentally repeating a meaningful syllable 'OM' (MOM session) (2). A similar session except that the test period was spent mentally repeating a neutral work, 'one' (COM session) (3). A session with non-targeted thinking (NT session). The subjects were familiar with both syllables, and had been meditating on 'OM' for 20 days. During the test periods of both MOM and COM sessions the rate of respiration (RR) and heart rate (HR) decreased significantly [(two factor ANOVA (RR), paired t test (RR. HR)]. Compared to the pre period. Mental repetition of 'OM' (but not 'one') caused a significant decrease in skin resistance level (SRL) (paired t test). This was taken to mean that the subject recognized the significance of the syllable. No significant change occurred during NT sessions.

Adult↗
PubMed1998

A review of mind-body therapies in the treatment of cardiovascular disease. Part 1: Implications for the elderly.

BACKGROUND: A review of research on complementary and alternative treatments, specifically mind-body techniques, was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and to provide a rationale for future research concerning successful aging. METHODS: Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet, and interviews conducted with practitioners. All studies since 1990 that examined mind-body treatments of cardiovascular disorders in the elderly were included. Mind-body practices evaluated were social support, cognitive-behavioral treatment, meditation, the placebo effect, hope, faith, imagery, spiritual healing, music therapy, hypnosis, yoga, t'ai chi, qigong and aikido. Studies conducted after 1990 were a priority, but when more recent literature was scarce, other studies using randomized, controlled trials were included. RESULTS: Mind-body techniques were found to be efficacious primarily as complementary and sometimes as stand-alone alternative treatments for cardiovascular disease-related conditions. Studies provided evidence for treatment efficacy, but the need for further controlled research was evident. CONCLUSIONS: Reviewers found only a handful of randomized, controlled research studies conducted in the United States. As a result, there is a lack of replicated studies with which to determine appropriate treatment dosage and the mechanisms by which many of the practices work. Compelling anecdotal evidence, the presence of some controlled research, overall cost effectiveness, and the lack of side effects resulting from mind-body treatments make further investigation a high priority.

Aged↗
PubMed1997

Comparison of changes in autonomic and respiratory parameters of girls after yoga and games at a community home.

The heart rate, breathing rate, and skin resistance were recorded for 20 community home girls (Home group) and for 20 age-matched girls from a regular school (School group). The former group had a significantly higher rate of breathing and a more irregular breath pattern known to correlate with high fear and anxiety, than the School group. Skin resistance was significantly lower in the School group, which may suggest greater arousal, 28 girls of the Home group formed 14 pairs, matched for age and duration of stay in the home. Subjects of a pair were randomly assigned to either yoga or games groups. For the former emphasis was on relaxation and awareness, whereas for the latter increasing physical activity was emphasized. At the end of an hour daily for six months both groups showed a significant decrease in the resting heart rate relative to initial values (Wilcoxon paired-sample rest), and the yoga group showed a significant decrease in breath rate, which appeared more regular but no significant increase in the skin resistance. These results suggest that a yoga program which includes relaxation, awareness, and graded physical activity is a useful addition to the routine of community home children.

Affective Symptoms↗
PubMed1997

Yoga breathing through a particular nostril increases spatial memory scores without lateralized effects.

Uninostril breathing facilitates the performance on spatial and verbal cognitive tasks, said to be right and left brain functions, respectively. Since hemispheric memory functions are also known to be lateralized, the present study assessed the effects of uninostril breathing on the performance in verbal and spatial memory tests. School children (N = 108 whose ages ranged from 10 to 17 years) were randomly assigned to four groups. Each group practiced a specific yoga breathing technique: (i) right nostril breathing, (ii) left nostril breathing, (iii) alternate nostril breathing, or (iv) breath awareness without manipulation of nostrils. These techniques were practiced for 10 days. Verbal and spatial memory was assessed initially and after 10 days. An age-matched control group of 27 were similarly assessed. All 4 trained groups showed a significant increase in spatial test scores at retest, but the control group showed no change. Average increase in spatial memory scores for the trained groups was 84%. It appears yoga breathing increases spatial rather than verbal scores, without a lateralized effect.

Adolescent↗
PubMed1997

Middle latency auditory evoked potentials in congenitally blind and normal sighted subjects.

Middle latency auditory evoked potentials were recorded in two groups of ten subjects each, viz, congenitally blind (CB) and age-matched subjects with normal vision (NV). The age range for both groups was 13 to 16 years. The CB group subjects had peripheral deficits, with absence of visual evoked responses. The peak latency of the Nb wave (the maximum negativity between 38 and 48 ms) was significantly lower in the CB group compared to NV group (p < .05, one-tailed, two factor ANOVA, Tukey test). In addition to these recordings from the vertex, recordings were also made from occipital areas, to test whether the visual cortex contributes to information processing at primary auditory cortical levels in the blind, as was reported in earlier studies on the generation of potentials during auditory selective attention. No such effect was observed. Hence, it appears that in blind subjects changes in generators of auditory middle latency evoked potentials are mainly related to latency, rather than to scalp distribution of these components.

Acoustic Stimulation↗