Calcium oscillations and waves during IgE receptor crosslinking.
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Adenosine↗
Biomedical subjects
B Hayes
Publications and source records attributed to B Hayes.
The effect of sampling condition on children's productions of consonant clusters.
An investigation was conducted to compare the effects of single word and connected speech sampling conditions on the production of consonant clusters. Speech samples were obtained from 40 children with speech sound impairments who were aged 3 years: 6 months to 5 years. The children's productions of 36 commonly occurring consonant clusters were compared across the two sampling conditions. Overall children's productions were more similar than different. Differences between the sampling conditions were apparent for three of the eight phonological processes studied, namely, cluster reduction, final consonant deletion, and epenthesis. Of 12 fine phonetic variations, only aspirated stops showed a significant difference between the sampling conditions. There was a wide range of individual variation.
Child Language↗
Dynamics of electroencephalographic sleep spindles and slow wave activity in men: effect of sleep deprivation.
Recent developments in the understanding of the neurophysiological mechanisms underlying electroencephalographic (EEG) slow waves and sleep spindles imply an inverse relationship between these two EEG activities. The interrelationship between slow wave activity (0.75-4.5 Hz) and sleep-spindle activity (12-15 Hz) in electroencephalograms recorded in nine male subjects, during nocturnal baseline sleep and during recovery sleep from 40 h of wakefulness, was analyzed by power spectral analysis based on the fast Fourier transform and by transient patterns detection algorithms. Both techniques revealed that spindle activity was highest in sleep stage 2, increased over consecutive non-rapid-eye-movement sleep (non-REM sleep) episodes and was suppressed during recovery sleep. In contrast, slow wave activity decreased over consecutive non-REM sleep episodes and was enhanced during recovery sleep. Analysis of the dynamics of spindle and slow-wave activity within non-REM sleep episodes demonstrated that in the initial 20% of these episodes both spindle activity and slow wave activity increased, whereafter slow wave activity continued to increase but the average amplitude of spindles and total spindle activity, but not spindle density, decreased. At the end of non-REM sleep episodes the reverse pattern was observed. Sleep deprivation induced a more rapid rise of both spindle and slow wave activity in the very beginning of sleep. These data demonstrate that when averaged per sleep episode or non-REM sleep episode an inverse relationship between SWA and spindle activity exists but that in the initial and final part of non-REM sleep episodes the association between these two activities is positive. This biphasic relationship is discussed with reference to the hypothesis that the transition from sleep spindles to slow waves is dependent on a progressive hyperpolarization of thalamo-cortical neurons.
Adult↗
Neonatal surgery: intensive care unit versus operating room.
The critically ill neonate with a surgical condition requires transfer to an operating room (OR), a process which may be associated with significant morbidity. In an effort to reduce such morbidity, we performed surgery on critically ill neonates in a designated area of our neonatal intensive care unit (NICU) over the past 4 years and have compared the outcome for infants operated on within the NICU with infants operated on in the OR over the same period. There were 81 procedures performed in the NICU compared with 112 in the OR. Infants operated on in the NICU had lower birthweights (1,758 g v 2,457 g), lower gestational ages (31.3 weeks v 35.8 weeks), and lower presurgical weights (2,118 g v 2,922 g) (all P < .0001). In addition, infants operated on in the NICU had a greater severity of illness with 78% requiring mechanical ventilation versus 26% for the OR group (P < .0001) with a higher presurgical FiO2 (.43 v .31, P = .005), and a higher presurgical mean airway pressure (8.0 cm H2O v 6.2 cm H2O) for infants requiring mechanical ventilation. The overall mortality was higher in the NICU group (14% v 2%), reflecting their underlying prematurity, illness, and anomalies. There was only one surgically related death, which occurred in the NICU group. There was no significant difference in culture-proven sepsis, length of surgery, change in weight, temperature, blood pressure, heart rate, FiO2, mean airway pressure, or oxygen index associated with surgery, but there was a significantly higher incidence of hyperthermia with a temperature of greater than 37.5 degrees C in the OR group (17.8% v 3.7%, P = .002). Our experience suggests that surgical procedures can be performed in the NICU for the unstable critically ill neonate with a morbidity comparable to that seen in the OR. Further experience is needed to compare the risks and benefits of this approach.
Critical Illness↗
Use of psychometric measures and nonorganic signs testing in detecting nomogenic disorders in low back pain patients.
The effect of financial compensation on responses to psychometric testing was studied in 231 chronic back pain patients. Item by item comparison of responses to two tests, readministered within 4 hours, yielded inconsistency scores. These inconsistency scores, along with scores on other psychometric measures and on Waddell's nonorganic signs test, of a group of 97 patients anticipating or receiving financial compensation (AFC), and a group of 134 patients not receiving or anticipating financial compensation (non-AFC) were compared. The AFC group had significantly higher mean scores than did the non-AFC group on the inconsistency measures, on almost all psychometric tests and on nonorganic signs. Almost all non-AFC subjects scored "0" on nonorganics, whereas 83% of AFC subjects scored "2" or higher. Prediction analysis revealed that the nonorganics score alone can predict AFC/non-AFC status; 90% of subjects were correctly classified. The inconsistency scores correctly classified 78%. Together, they correctly classified 93%. It was concluded that nonorganic scores and inconsistency scores (as defined by the investigators) distinguish between, and can predict membership in AFC and non-AFC groups. The significantly higher inconsistency scores obtained by the AFC group suggest that these psychometric test results are unreliable and hence invalid for this group.
Adult↗
Speech naturalness and prolonged-speech treatments for stuttering: further variables and data.
It is well known that unusual speech quality may result from stuttering treatments that are based on prolonged speech. However, empirical information concerning the speech quality associated with those treatments is lacking. The present study was designed to contribute such empirical information. Results indicated that speech quality assessments of posttreatment clients, using Martin, Haroldson, and Triden's (1984) speech naturalness scale, gave similar results regardless of whether they were based on monologues or conversations. The speech quality of those clients remained stable at the conclusion of their treatment program. Further, there was a significant, positive correlation between pretreatment speech measures and measures of speech naturalness made after the establishment of stutter-free speech. The subjects whose pretreatment stuttering was the most severe had posttreatment speech naturalness scores that were more than two scale values worse than the subjects whose pretreatment stuttering was the least severe. Speech naturalness scale scores are presented for nonstutterers and posttreatment stutterers and these data are compared with existing findings.
Adolescent↗
European Standardisation Committee on Anaesthetic Equipment.
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Anesthesiology↗
Prolonged periodic breathing: significance in sleep studies.
Periodic breathing (PB) is a pattern of breathing that is frequently recognized in infants being studied for possible sleep apnea. Infants presenting to a sleep laboratory over a 3 1/2-year period who had evidence on their initial study of prolonged (greater than 15% of total sleep time) PB were prospectively studied in an effort to determine the significance of this pattern of breathing. Of the 331 infants studied, 40 demonstrated prolonged PB. Sixteen of these infants, who were of 37 weeks' gestation or greater at birth and did not receive pharmacologic therapy, were studied on at least two occasions (group 1). Of the remaining 24 infants, 11 were treated with methylxanthines by their attending physician (group 2), and 13 did not return for sequential studies (group 3). All infants who were of less than 37 weeks' gestation at birth were separately evaluated (group 4). For group 1, who were studied at a mean age of 15 postnatal weeks, there was a mean of 36.4% periodicity which decreased on the second study to 18.0%. By the fourth study, this had decreased to 9.2%. In group 2, there was a mean of 41.3% periodicity during the first study which decreased to 6.4% on the second study. Infants of group 3 had a mean of 31.4% PB on their initial study and the premature infants, group 4, had 30.1% PB. All infants showed a decrease in PB with sequential studies and no infant was known to have died of sudden infant death syndrome or any other disorder in the first year of life.(ABSTRACT TRUNCATED AT 250 WORDS)
Humans↗
Novel area serving binocular vision in the retinae of procellariiform seabirds.
Procellariiforms are pelagic seabirds which fly close to the sea surface and feed either by taking items from the surface or by shallow diving. The retinal ganglion cells in five species (Manx shearwater, Puffinus puffinus, Kerguelen petrel, Pterodroma brevirostris, great shearwater, Puffinus gravis, broad-billed prion, Pachyptila vittata, and common diving petrel, Pelecanoides urinatrix) were examined by Nissl staining and also by silver staining in the case of the common diving petrel. In all five species, a well-defined region in the dorsotemporal retina, close to the ora, was identified. This region is characterized by the presence of ganglion cells which are both regularly arrayed and larger than those found in the rest of the retina. These cells also have a large dendritic field of sparsely branched dendrites with much dendritic overlap between cells, thick axons, and dendrites confined to the proximal inner plexiform layer. Morphologically, they appear similar to the alpha cells of the retina in cats. It is suggested that the region containing these cells should be regarded as a retinal area, and the name area giganto cellularis is proposed. In the Manx shearwater, it is found that this novel area projects visually into the binocular field below the bill. Unlike previously described areas in avian retinae, it seems that this novel area is not concerned with high spatial resolution. It may function in the detection of objects on the sea surface and/or be concerned with the detection of the actual sea surface as a bird flies low over it.
Animals↗
The accuracy of patients' understanding of the bases for their medical condition.
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Humans↗
Neuroleptic malignant syndrome: a case for electroconvulsive therapy.
A case of prolonged and refractory neuroleptic malignant syndrome was treated successfully with electroconvulsive therapy. Neuroleptic malignant syndrome and its treatment are reviewed.
Adult↗
Congenital retinal folds in Sheffield-Wistar rats.
Retinal folds are described in male rats of a Wistar-derived strain, which occasionally shows microphthalmia and cataract. The less severe lesions mainly affect the outer retinal layers and contain microretinal detachment, cell rosettes, phagocytic cells and lipid debris. More severe folds involve all the retinal layers, exhibit subretinal haemorrhage, and photoreceptor outer segment debris throughout the lesion and on the vitreal surface. The lesions are discussed in relation to previous observations of retinal folds.
Animals↗
Determinants of daytime sleepiness in obstructive sleep apnea.
To investigate determinants of daytime sleepiness in obstructive sleep apnea syndrome (OSAS), we studied 100 unselected OSAS patients by nocturnal polygraphic recording and the Multiple Sleep Latency Test (MSLT). Data obtained were submitted to three types of analysis. Respiratory disturbance index, oxygen saturation indices, body mass index, and total nocturnal sleep time did not significantly correlate with daytime sleepiness, as measured by the MSLT. Analysis of subgroups based on weight and degree of alertness also showed a nonsignificant correlation with daytime sleepiness. The best predictor of the excessive daytime sleepiness (EDS) frequently found in OSAS patients was the nocturnal polygraphic recording of the sleep disturbances and sleep structure anomalies that reflect the brain's overall dysfunction in OSAS. Understanding why an electroencephalogram arousal response occurs during sleep in association with abnormal breathing and how this response can become blunted may help us to better predict the development of EDS.
Body Weight↗
Heat and moisture exchangers in artificial ventilation. An experimental study of the effect of gas leakage.
The effect of gas leakage around an uncuffed tracheal tube on the performance of Heat and Moisture Exchangers (HME) was examined experimentally. Such leaks were shown to cause measurable decreases in the humidity output and efficiency of HME. The magnitude of the decrease in humidity output was shown to be dependent upon the proportion of expired volume which was leaked, and on the inspired volume. Other factors are discussed.
Equipment Failure↗
Ion-induced DNA structure change in nucleosomes.
Physical methods have been used to study calcium binding to the nucleosome core particle. Equilibrium dialysis of Ca2+ and spectroscopic analysis of a Ca2+ analogue show that the ion binds tightly to the particles, resulting in a significant change of DNA circular dichroism. This suggests that base stacking may be altered as a result of Ca2+ binding. In the presence of Ca2+, the absorbance and fluorescence properties of methylene blue (MB), a DNA-specific intercalator, confirm that the dye binds tightly to nucleosomes by intercalation. However, secondary changes occur which suggest that the MB binding site is altered as a result of Ca2+ binding. Triplet state anisotropy decay and triplet lifetime quenching both show that in the Ca2+-nucleosome complex, methylene blue is capable of wobbling over a substantial angular range at its binding site. To explain these data, it is proposed that Ca2+ binding to nucleosomes causes DNA to fold by means of a series of sharp bends (kinks). The properties of bound MB are best explained if it is presumed that the intercalator binds tightly to such kinked sites in the nucleosome. On the basis of these observations, we discuss the possibility that multivalent ion concentration in the nucleus is high enough that the smooth to kinked helix equilibrium may be near to its midpoint. Near such a midpoint, the secondary structure of DNA in the nucleosome might prove to be sensitive to effector molecule binding and to site-specific variation of DNA or histone composition within genes.
Animals↗
Narcolepsy, cataplexy, heart rate, and blood pressure.
Seven narcoleptic patients had serial measurements of blood pressure taken during nocturnal sleep over a period of 2 or 3 successive nights. Blood pressure was measured using a Doppler system with a cuff that automatically inflates every 15 min. There was no difference in the blood pressure measurements throughout the night compared with normal control subjects. Blood pressure followed the patterns of normal nocturnal variation; there was a nonsignificant increase in REM sleep compared with stage 3-4 NREM sleep. Studies of heart rate immediately preceding cataplectic attacks were inconclusive in identifying cardiovascular changes preceding muscle weakness.
Adult↗
Viloxazine hydrochloride in narcolepsy: a preliminary report.
Twenty-three narcoleptic subjects participated in a single-blind drug study with placebo-viloxazine hydrochloride (100 mg/day). One woman discontinued the study because of nausea and headaches during the treatment period. The remaining 22 subjects were polygraphically monitored during baseline, The remaining 22 subjects were polygraphically monitored during baseline, placebo intake, viloxazine treatment, and placebo intake following 48 h of drug withdrawal. Symptoms and side effects were evaluated subjectively and objectively. Except for the subject who discontinued the study, viloxazine was well tolerated, particularly in elderly subjects. The drug had an inhibitory effect on REM sleep, cataplexy, and other auxiliary symptoms. While there is no objective evidence that it heightens alertness, patients reported fewer sleep attacks.
Adult↗
Diabetic autonomic dysfunction, blood pressure, and sleep.
We measured serially the blood pressure of 7 normal controls and 11 Type I insulin-dependent and 6 Type II non-insulin-dependent diabetic patients during sleep. All subjects underwent 2 or 3 nights of monitoring during which blood pressure was measured with an arteriosonde, a Doppler-type system with a cuff that automatically inflates every 15 minutes. All 7 normal controls, 3 of 11 Type I, and all 6 Type II diabetic patients had normal results from bedside tests of autonomic function. The Type I patients had abnormal systolic blood pressure measurements throughout the night. Unlike normal controls and Type II diabetics, their blood pressure did not rise progressively in the early morning hours. During rapid eye movement (REM) sleep, their blood pressure measurements were significantly higher and lower than values measured during non-REM sleep, in sharp contrast to those in the other two groups, whose REM sleep-related blood pressure values were slightly above the preceding non-REM sleep measurements.
Adult↗