Heterosexual transmission of HIV.
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Female↗
Biomedical subjects
S Brody
Publications and source records attributed to S Brody.
Speaking from the heart: cardiovascular components of stress rating changes and the relative reactivity of physiological and psychological variables.
The first part of the experiment compared the relative reactivity of various cardiovascular measurements and self-reported assessment of mental arithmetic, an active coping stress task. It was found that the self-reported stress rating was more responsive (student's t = 9.4) than the physiological measurements. Among the cardiovascular indices, heart rate was the most responsive (student's t = 6.5), followed by the interval between R-wave and the maximal systolic pressure (student's t = 5.0). The second part of the study used a multiple regression to examine the cardiovascular components of change in stress rating following mental arithmetic. Both resting (psychophysiological "trait" variables) and change under stress (psychophysiological "state" variables) were used to predict change in stress rating. Stress rating increase were associated with greater maximal systolic pressure rate of rise (finger dP/dt) at baseline and less heart rate increase during mental arithmetic, yielding a multiple r of 0.67. The dual autonomic nature of active coping stress response is discussed. The shortcomings of using a correlate of a correlate are noted.
Adult↗
Slow cortical potential biofeedback and the startle reflex.
The negativity of slow cortical potentials (SCP) of the surface EEG is a measure of brain excitability, correlating with motor and cognitive preparation. Self-control of SCP positivity has been shown to reduce seizure activity. Following SCP biofeedback from a central EEG electrode position, subjects gained bidirectional control over their SCP. The current study used a modified feedback methodology, and found a positive relationship between negativity and magnitude of EMG startle response (a measure of cortical and subcortical arousal, particularly aversive response disposition). Greater success in SCP differentiation was associated with self-report of less relaxation during negativity training.
Adult↗
A simplified approach to the restoration of a maxillary single tooth implant.
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Composite Resins↗
Behavioral and psychophysiological predictors of self-monitored 19 month blood pressure change in normotensives.
Selected demographic, behavioral and psychophysiological variables (sex of the subject, exercise, coffee and cigarette consumption, baroreceptor stimulation-dependent pain dampening, initial blood pressure, body mass index, daily stress rating, reactivity to mental stress as measured by change in stress rating and heart rate and blood pressure from resting to mental arithmetic conditions) were entered into a stepwise multiple-regression equation to predict changes of oscillometrically self-measured tonic blood pressure in 80 normotensives over a 19 month period. The prediction equation (r = 0.55) associated increases in diastolic blood pressure with baseline diastolic blood pressure, more baroreceptor stimulation-dependent pain inhibition, and less heart rate change during mental arithmetic. There were no significant predictors of systolic changes, and no sex differences. Results are discussed in terms of the learned model of hypertension.
Adult↗
Baroreceptor stimulation: pain perception and sensory thresholds.
Baroreceptor activity has been implicated in the modulation of pain. Sensory detection thresholds and pain ratings were measured in a group of 28 men during carotid baroreceptor manipulation with the PRES (phase-related external suction) neck suction technique. Brief, cardiac phase-related electrical impulses were delivered intracutaneously to the finger. The results indicate that minimum baroreceptor activity was associated with more severe pain, but had no effect on sensory detection threshold. The results are discussed in terms of the learned model of hypertension.
Adult↗
Circadian rhythms in microorganisms.
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Animals↗
Traditional ideology, stress, and psychotherapy use.
I examined the relationship of traditional ideology, a characterological and cultural variable, and life stress and symptoms of depression to an openness to the use of psychotherapy. American college students (N = 150) completed several questionnaires; the results showed that despite higher levels of symptoms of depression among traditionals, a strong negative relationship existed between traditional ideology and attitudes toward and use of psychotherapy. Stressful life events, symptoms of depression, social desirability scores, and religious behaviour were unrelated to attitudes toward and use of psychotherapy.
Adult↗
Reduced pain during baroreceptor stimulation in patients with symptomatic and silent myocardial ischaemia.
OBJECTIVE: Baroreceptor activation has been shown to reduce pain, and the accumulation of such pain reduction has been implicated in the operant learning (under certain circumstances) of hypertension. The current study is an examination of differences in the pain dampening effects of baroreceptor activity in patients with symptomatic and asymptomatic myocardial ischaemia. The objective was to determine whether there are differences between patients with symptomatic and silent myocardial ischaemia with respect to their antinociceptive response to baroreceptor stimulation, and, if so, whether these differences could be related to the absence of angina pectoris pain in patients with silent myocardial ischaemia. METHODS: Sensory detection and electrical pain thresholds were compared in nine symptomatic and 10 asymptomatic patients with replicable myocardial ischaemia during PRES (phase related external suction) carotid baroreceptor manipulation in which the pressure inside a neck cuff was phase locked in time to the R wave of the ECG and negative pressure was applied during either systole or diastole. Tourniquet pain thresholds were also determined. RESULTS: It was found that (1) external baroreceptor manipulation had no effect on detection thresholds; (2) painful stimuli were judged by both symptomatic and asymptomatic patients as less intense when delivered during maximum baroreceptor activity; (3) symptomatic and asymptomatic patients did not differ in their sensory detection thresholds; and (4) asymptomatic patients had significantly higher ischaemic (tourniquet) pain thresholds than symptomatic patients. CONCLUSIONS: The results indicate that baroreceptor activity can modify the intensity of painful stimuli. The degree to which baroreceptor manipulation affects pain does not appear to differ between patients with painful and silent myocardial ischaemia. Thus the baroreceptor dependent pain inhibition effects seems not to be responsible for the higher ischaemic pain threshold found in the silent myocardial ischaemia group.
Electric Stimulation↗
A responsible geezer's analysis of the Clinton health proposal.
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Aged↗
Emotional qualities of odors and their influence on the startle reflex in humans.
Recent human and animal research suggests that the startle reflex might serve as a psychophysiological indicator of the emotional valence of foreground stimulation. The present experiment was designed to evaluate the emotional effects of positive and negative odorant stimuli. We examined the effects of continuous hydrogen sulphide (H2S) and vanillin stimulation on the magnitude of the acoustic startle reflex (measured at the M. orbicularis oculi) and on ratings of subjective valence in 16 healthy subjects. In accordance with the view that odors have emotional qualities, we found that H2S, a presumed negative foreground stimulus, significantly enhanced the startle-reflex amplitude relative to neutral air stimulation, whereas vanillin, a positive foreground stimulus, tended to reduce the reflex amplitude compared with neutral air stimulation. Both odorant stimuli were rated as equally intense by the subjects, and heart rate and electrodermal activity were not affected differentially by the two odorants.
Acoustic Stimulation↗
Effects of PRES baroreceptor stimulation on thermal and mechanical pain threshold in borderline hypertensives and normotensives.
Prior studies have noted a pain relieving effect of baroreceptor stimulation and of higher tonic blood pressure in animals and humans. The present study used a new technique for the controlled, noninvasive stimulation of human carotid baroreceptors (PRES). PRES baroreceptor manipulation was delivered to both normotensive subjects (n = 11) and medication-free labile hypertensive subjects (n = 10) during both thermal and mechanical pain. Consistent with prior research, hypertensives had a higher threshold for thermal pain than did normotensives. PRES baroreceptor manipulation had no significant effect on thermal pain threshold for either group. For the mechanical pain model, the opposite results were obtained; group pain thresholds did not differ, but there was a significant PRES baroreceptor stimulation effect of increasing pain threshold for both groups. Results are discussed in terms of specific features of the stimuli, dampening of pain in hypertensives, and adaptation to pain.
Adult↗
Classical conditioning of pain responses.
Classical conditioning is involved in the acquisition of chronic pain. The present study investigated whether experimental pain responses can be conditioned using auditory stimuli in a differential trace conditioning paradigm. 16 healthy subjects served as paid volunteers. The UCS was an intracutaneous electrical stimulus applied to the left middle-finger (10 ms duration). Tones of 1000 and 1400 Hz (both 80 dB SPL, 50 ms) were used as CS+ and CS-, respectively. A trace conditioning paradigm was used with an 800 ms interval between CS and UCS. Somatosensory event related potentials (SEP) and auditory event related potentials (AEP) were recorded from 29 electrode sites. Subjective pain reports were measured with an adjective list that allowed a detailed description of subjects' sensations elicited by painful and auditory stimuli. Data revealed significant differences of the subjective sensations between the CS+ and CS-, but no differences in the amplitudes and latencies of the P50, N100, P200, and P300 AEP components. No changes in the topographical organization of the CS+ and CS- were found. A significant differential negativity in the brain sites responsible for processing the UCS was obtained, which is attributed to the anticipation of the UCS after CS+ presentation.
Acoustic Stimulation↗
Mitochondrial cardiolipin in diverse eukaryotes. Comparison of biosynthetic reactions and molecular acyl species.
Cardiolipin, a unique dimeric phospholipid of bacteria and mitochondria, can be synthesized by two alternative pathways discovered in rat and Escherichia coli, respectively. In mitochondrial preparations from fungi (Saccharomyces cerevisiae, Neurospora crassa), higher plants (Phaseolus aureus), molluscs (Mytilus edulis) and mammals (rat liver, bovine adrenal gland), cardiolipin was synthesized from CDP-diacylglycerol and phosphatidylglycerol, suggesting a common eukaryotic mechanism of cardiolipin formation which is in contrast to the prokaryotic biosynthesis from two molecules of phosphatidylglycerol. All mitochondrial cardiolipin synthases were inhibited by lysophosphatidylglycerol, were insensitive to N-ethylmaleimide and required divalent cations, although they had different cation specificities. The molecular species of cardiolipin from rat liver, bovine heart, S. cerevisiae and N. crassa were analysed by high-performance liquid chromatography of the derivative 1,3-bis[3'-sn-phosphatidyl]-2-benzoyl-sn-glycerol dimethyl ester. Cardiolipins from these organisms contained mainly monounsaturated or diunsaturated chains with 16 or 18 carbon atoms, resulting in a relatively homogeneous distribution of double bonds and carbon numbers among the four acyl positions. About half of the molecular species were symmetrical, i.e. they combined two identical diacylglycerol moieties. In N. crassa, the same species pattern was found at growth temperatures of 25 degrees C and 37 degrees C. Tentative molecular models were created for the most abundant molecular species and subjected to energy minimization. Geometric data, derived from these models, suggested similarities in the gross structure of the major cardiolipin species from different sources.
Adrenal Glands↗
Blood pressure changes validate phase related external suction, a controlled method for stimulation of human baroreceptors.
Phase related external suction (PRES), a new controlled method for manipulating activity in human baroreceptors, applies precisely timed bursts of suction and pressure within the cardiac cycle through an external neck cuff. Seven healthy adult men participated in 32 pseudo-random trials of baroreceptor stimulation and inhibition. Blood pressure was assessed both intra-arterially and with a noninvasive device. In the present study, PRES baroreceptor stimulation elicited invasively measured blood pressure decreases of about 2.5 mmHg (0.33 kPa) and heart rate decreases of about 5 beats,min-1, while baroreceptor inhibition increased invasively measured blood pressure by about 1.5 mmHg (0.20 kPa) and heart rate about 2.5 beats.min-1. It was concluded that PRES is an effective method for baroreceptor manipulation with weaker size effect but better control of nonspecific factors in human subjects than other baroreceptor manipulation techniques. The noninvasive blood pressure measurement device was less sensitive to experimental variation than was the invasive device.
Adult↗
Cigarette smoking, blood lipids, and baroreceptor-modulated nociception.
Activation of arterial blood pressure has been shown to influence higher central nervous activity. In animals, induction of sleep-like states and increases of seizure and pain thresholds in response to baroreceptor stimulation have been reported. In certain human groups, mechanical stimulation of the carotid baroreceptors also increases pain thresholds. The present paper examines the hypothesis that smokers show baroreceptor dependent antinociception as compared to non-smokers. It is speculated that one effect which rewards smoking is the nicotine induced phasic blood pressure increase which leads to baroreceptor stimulation and dampens pain perception. One hundred and twenty subjects were investigated using a recently developed mechanical baroreceptor stimulation technique and an electrical pain stimulus. The group of heavy smokers showed the predicted effect: their pain thresholds were enhanced during conditions of increased baroreceptor activity as compared to the control condition. The group of medium, light and non-smokers, however, did not show this effect. Neither blood lipid levels nor diastolic or systolic blood pressure paralleled the group differences on baroreceptor dependent antinociception. In heavy smokers, the nicotine induced phasic blood pressure increases might have baroreceptor dependent pain dampening effects, which might be among the reinforcing qualities of smoking.
Adult↗
Effects of smoking on thermal pain threshold in deprived and minimally-deprived habitual smokers.
This study examined the antinociceptive effects of smoking in nine habitual smokers under deprived (12 h) and minimally-deprived (< 30 min) conditions. Pain threshold for thermal stimuli, heart rate, blood pressure and ratings of mood, arousal, dominance and well-being were assessed before and after smoking a cigarette. Over-all, smoking affected all measured variables in the expected direction, leading to increased physiological activity, elevated pain threshold and improved mood. However, most of these effects depended on the deprivation status of the subjects, such that smoking after deprivation increased pain threshold whereas smoking after minimal deprivation did not. Pain threshold before smoking was the same for both groups. Deprived subjects had lower pre-smoke diastolic blood pressure, heart rate, and arousal levels, which rose to equal minimally-deprived subjects' scores after smoking.
Adult↗