Attentional modulation of the auditory steady-state response across the cortex.

Selective auditory attention allows us to focus on relevant sounds within noisy or complex auditory environments, and is essential for the processing of speech and music. The auditory steady-state response (ASSR) has been proposed as a neural measure for tracking selective auditory attention, even within continuous and complex soundscapes. However, the current literature is inconsistent on how the ASSR is influenced by selective attention, with findings based primarily on attention being directed to either ear rather than to sound content. In this experiment, a mixture of melody streams was presented to both ears identically (diotically) as we examined if selective auditory attention to sound content influences the ASSR. Using magnetoencephalography (MEG), we assessed the stream-specific ASSRs from three frequency-tagged melody streams when attention was directed between each melody stream, based on their respective pitch and timing. Our main results showed that selective attention enhances the ASSR power of an attended melody stream by 14% at a general sensor level. This ability to readily capture attentional changes in a stimuli-precise manner makes the ASSR a useful tool for studying selective auditory attention, especially in complex auditory environments. As a secondary aim, we explored the distribution of cortical ASSR sources and their respective attentional modulation using a distributed source model of the ASSR activity. Notably, we uncovered the existence of ASSR attentional modulation outside the temporal cortices. Across-subject averages of the attentional enhancement over the cortical surface suggest that frontal regions show up to ~80% enhancement, while temporal and parietal cortices were enhanced by 20-25%. Importantly, this work advocates a novel 'beyond the temporal cortex' perspective on ASSR modulation and also serves as a template for future studies to precisely pin-point which cortical sites are more susceptible to ASSR attentional modulation.

Prevention of relapse/recurrence in major depression by mindfulness-based cognitive therapy.

This study evaluated mindfulness-based cognitive therapy (MBCT), a group intervention designed to train recovered recurrently depressed patients to disengage from dysphoria-activated depressogenic thinking that may mediate relapse/recurrence. Recovered recurrently depressed patients (n = 145) were randomized to continue with treatment as usual or, in addition, to receive MBCT. Relapse/recurrence to major depression was assessed over a 60-week study period. For patients with 3 or more previous episodes of depression (77% of the sample), MBCT significantly reduced risk of relapse/recurrence. For patients with only 2 previous episodes, MBCT did not reduce relapse/recurrence. MBCT offers a promising cost-efficient psychological approach to preventing relapse/recurrence in recovered recurrently depressed patients.

Plasma levels of antioxidant vitamins, selenium, total sulfhydryl groups and oxidative products in ischemic-stroke patients as compared to matched controls in Taiwan.

The possible involvement of oxidative damage and antioxidant protection has been suggested in the pathogenesis of stroke which is the second-leading cause of death in Taiwan. In this study we investigated the relationship between ischemic stroke and plasma status of antioxidants and oxidative products. Plasma levels of vitamin A, alpha-tocopherol, carotenoids, selenium (Se), total SH groups (T-SH), thiobarbituric acid-reactive substances (TBARS) and protein carbonyl, a marker of protein damage, were determined in ischemic-stroke patients (n = 36, blood sampled within 24 hrs after the clinical event) in comparison with 21 matched controls. The cholesterol-adjusted carotenoids and vitamin E were significantly lower (P < 0.05) in the plasma of ischemic-stroke patients than those of the controls. TBARS were higher (P < 0.05) in the patients than in the controls but Se, T-SH and protein carbonyls were not significantly different between the two groups. Separation of the patients into small-artery ischemic stroke (SAIS, n = 17) and large-artery ischemic stroke (LAIS, n = 19) groups revealed that both carotenoids/cholesterol and vitamin E/cholesterol ratios were significantly lower in both LAIS and SAIS groups than the controls (n = 21) while vitamin A/cholesterol was not different among the three groups. TBARS were only significantly higher in the LAIS group. The results demonstrated that, within 24 hrs after the clinical event, the acute-ischemic stroke patients had lowered levels of cholesterol-adjusted carotenoids and alpha-tocopherol but elevated levels of TBARS in the plasma as compared to the matched controls. It remains to be resolved as to whether enhanced lipid peroxidation is a cause or a result of lowered antioxidants in ischemic stroke.

The search for HLA-matched donors: a summary of HLA-A*, -B*, -DRB1/3/4/5* alleles and their association with serologically defined HLA-A, -B, -DR antigens.

This report summarizes data obtained from several large studies including the WHO HLA Nomenclature Committee, the International Cell Exchange, UCLA, the British Society for Histocompatibility and Immunogenetics Rare Cell Exchange and the National Marrow Donor Program and individual laboratories aimed at identifying a serologic type for specific HLA-A,-B,-DRB allelic products. Alleles that are poorly characterized at the serologic level are indicated and an approach is suggested for obtaining the information needed to clarify their serologic typing. The tables provided will be useful in guiding searches for an unrelated donor in which patient and/or potential donors are typed either by serology or by DNA-based methods and will provide a "dictionary" of potential equivalents between HLA "types" obtained by the two methods.

The effect of transcutaneous electrical nerve stimulation (TENS) on autonomic cardiovascular reflexes.

Transcutaneous electrical nerve stimulation (TENS) has been shown to have an anti-ischaemic effect in patients with angina and peripheral vascular disease that appears to be additional to any analgesic action. The mechanism for this anti-ischaemic effect is not known but it is possible that TENS interferes with the autonomic responses to ischaemia. To determine if TENS has any direct action on autonomic reflexes we have assessed the effect of high frequency TENS on a variety of standard tests of autonomic cardiovascular reflexes in 10 normal subjects. Tests were done on four consecutive days at the same time and TENS therapy or placebo was randomly allocated on 2 days each. Results of the tests were assessed by one person 'blinded' to the randomization order. These showed that TENS was associated with a significant reduction in the rise of the diastolic blood pressure (21.8 +/- 2.3 v. 17.6 +/- 17 mmHg; p < 0.05) during isometric exercise, using sustained Handgrip. There was no significant effect discernible on the changes of heart rate and blood pressure during the Valsalva manoeuvre, cold face stimulus or head-up tilt. Transcutaneous electrical nerve stimulation appears, therefore, to have a mild inhibitory action on those reflexes mediated predominantly by the sympathetic nervous system and this is more apparent when the stimulation may be greater, as during isometric exercise.

The efficacy of different umbilical cord care regimens: an in vitro study on their drying and antimicrobial effect.

BACKGROUND: Topical regimens have been used for umbilical cord care for different purposes, but their drying efficacy has rarely been statistically analyzed. We designed an in vitro study with six regimens to determine which one can achieve the best drying and antimicrobial effects in umbilical cord care. METHODS: Twenty-seven umbilical cords were resected when babies were born. Each cord was cut into seven segments in appropriate length and randomly labeled to seven groups. Six regimens including 75% alcohol, 90% alcohol, tincture povidone-iodine, aqua povidone-iodine, Chinese herbs, and one powder agent (M) were used topically on six groups of umbilical cords once daily. The control group received no treatment. Daily weight of the cords was recorded for 7 days, and bacterial culture was performed on the sixth day. RESULTS: All study groups presented similar algebraic functional relationship between weight change and time. The drying effect occurred mostly within the first 3 days (weight loss 88.6%), especially on the first day (62.1%). Mean ratio of the final weight/initial weight was 10.2%. Significant day-by-day weight loss was noted from day 1 to day 5 (p < 0.001). Both aqua and tincture povidone-iodine groups showed not only satisfied drying effect but also significantly better antimicrobial effect than other groups. CONCLUSIONS: Povidone-iodine has both good drying and antimicrobial effects in umbilical cord care. As the topical use of povidone-iodine has been reported to relate to transient neonatal hypothyroidism, we suggest it to be used only as a good substitute if there are signs of umbilical cord infection.

Is intramuscular mivacurium an alternative to intramuscular succinylcholine?

BACKGROUND: Mivacurium's rapid onset and short duration of action in children suggests that intramuscular administration might treat laryngospasm and facilitate tracheal intubation without producing prolonged paralysis. Accordingly, the authors measured the neuromuscular effects of intramuscular mivacurium in anesthetized infants and children. METHODS: Twenty unpremedicated infants and children (3 months to 5 yr of age) were anesthetized with nitrous oxide and halothane and permitted to breathe spontaneously. When anesthetic conditions were stable, mivacurium was injected into the quadriceps or deltoid muscle. Minute ventilation and adductor pollicis twitch tension were measured. The initial mivacurium dose was 250 micrograms/kg and was increased (to a maximum of 800 micrograms/kg, at which dose the trial was ended) or decreased according to the response of the previous patient, the goal being to bracket the dose producing 80-90% twitch depression within 5 min of drug administration. RESULTS: No patient achieved > 80% twitch depression within 5 min of mivacurium administration. Peak twitch depression was 90 +/- 13% (mean +/- SD) for infants and 88 +/- 15% for children at 15.0 +/- 4.6 min and 18.4 +/- 6.4 min, respectively. Ventilatory depression (a 50% decrease in minute ventilation or a 10-mmHg increase in end-tidal carbon dioxide tension) occurred at 9.0 +/- 4.4 min in nine infants and 13.6 +/- 7.5 min in 10 children; ventilatory depression did not develop in one infant given a dose of 350 micrograms/kg. Time to peak twitch depression or ventilatory depression was not faster with larger doses. CONCLUSIONS: Although ventilatory depression preceded twitch depression, both occurred later with intramuscular mivacurium than would be expected after intravenous mivacurium or intramuscular succinylcholine. The authors speculate that the onset of intramuscular mivacurium is too slow to treat laryngospasm or to facilitate routine tracheal intubation in infants or children, despite administration of large doses.

Assessment and training of clinical interviewing skills: analogue analysis and field replication.

Two studies were conducted to assess the train clinical interviewing skills. In Experiment 1, eight university practicum students ("therapists") and either role played or volunteer "clients" were audiotaped during simulated interviews. Following the collection of baseline data on both therapist and client responses, training was provided by way of written materials, classroom instruction and practice, and quizzes. Results of a multiple baseline design across subjects showed improvements in therapists' interviewing skills and subsequent increases in client responding. Experiment 2 replicated and extended the research to a hospital outpatient clinic, in which therapists interviewed the parents of children with behavior problems. In addition, four months following the completion of Experiment 2, follow-up data collected during a maintenance condition showed continued high levels of therapist and client behavior. Finally, a panel of expert peers indicated that each response category was judged highly relevant to the behavioral assessment process.