Dissociation between sympathetic-adrenal and pituitary-adrenal responses to an achievement situation characterized by high controllability: Comparison between type A and type B males and females

Type A and Type B university students of both sexes performed a choice-reaction task that was designed to allow each subject to perform at his/her preferred pace and to maintain control over the stimulus rate throughout a period of sustained work. Type As selected faster stimulus rates, and coped more effectively with their total work load than did Type Bs with their lesser load. The superior achievement of the Type A group was not reflected in self-reports of subjective arousal, nor in physiological arousal indices, e.g. heart rate, and catecholamine and cortisol excretion. Comparison between sexes (Type A and Type B persons) showed that males reported exerting significantly more effort than females and, accordingly, secreted significantly more adrenaline. A common characteristic of all groups was the dissociation between sympathetic-adrenal and pituitary-adrenal arousal, catecholamine output increasing and cortisol output decreasing in response to the achievement demands. The rise in catecholamine output was interpreted in terms of the mobilization of effort induced by the task, and the decrease of cortisol in terms of the high level of personal control in performing the task.     

Cardiovascular responses to intermittent noise in type A and B female subjects

Heart-rate and blood pressure measurements allowed analysis of cardiovascular responses (CVRs) to an intermittent pink noise in 9 Type A (coronary prone) and 8 Type B (non-prone) female subjects (Ss). If all Ss are sorted out in sensible, moderately sensible and poorly sensible subgroups, according to similarity in evolution of their heart rates and by completely identifying their heart rate reactivity, results of the analysis do not cross-check those of the behavioral A/B distinction. Although 7 out of 8 B Ss cluster in the moderately sensible subgroup, and although sensible Ss are all of Type A, A Ss are distributed almost equally in the 3 categories, and provide all varieties of CVR responses. Diversity of A Ss for CVR has no relationship with their scores on the Bortner scale.     

Physiological responses of type A and type B men during cognitive performance

Twenty male medical students classified as Type A or Type B solved a Concept Identification (CI) problem while measurements were taken on cardiovascular and somatic activity. The As produced significantly more overall electromyogram (EMG) activity and greater vasomotor activity than the Bs at baseline and during the task. Both Type As and Bs showed significantly higher levels of Heart Rate (HR), systolic and diastolic blood pressures, skin conductance, frontal EMG, and lower levels of vasomotor activity during work on the problem than during pre- and post-problem baselines. Type As showed significant negative correlations between total errors during CI and level of vasomotor activity, and between postsolution response latency and skin conductance. Type Bs showed a strong positive association between presolution response time and heart rate that did not hold for the As. The As appear to have shown sympathetic activation associated with quality of problem-solving performance, while the B's showed a relationship that suggested an impaired efficiency of performance associated with cardiac activation.     

Ethnic differences in cardiovascular responses to laboratory stress: A comparison between asian and white americans

Compared to other ethnic groups, Asian Americans show significantly lower rates of cardiovascular disease (CVD). We tested the hypothesis that Asian Americans would show reduced cardiovascular responses to laboratory stressors than Caucasians. Forty-three Asians (18 men, 25 women) and 77 Caucasians (36 men, 41 women) with a mean age of 24 years (SD = 3.93) participated in a stress reactivity protocol consisting of four tasks (speech, serial subtraction, mirror tracing, handgrip) while heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured. Asian Americans demonstrated overall lower reactivity across tasks for SBP F(1,117 = 7.48, p < .01) and a trend toward lower HR response F(1,117 = 3.18, p < .10). A significant ethnicity by task interaction was observed for HR reactivity F(3,351 = 2.94, p < .05) such that Caucasians showed greater responses for the subtraction task.     

A comparison of bezafibrate and clofibrate in type II B and type IV hyperlipoproteinemia

In 36 patients with primary hyperlipoproteinemia of type II B or IV the effect of bezafibrate, a new derivate of clofibrate, has been compared with the effect of clofibrate. In an open cross-over-study the effect of 1.5 g clofibrate p.d. has been compared with that of 450 mg bezafibrate p.d. for several months. The effect of bezafibrate on plasma triglyceride concentration and plasma cholesterol concentration was more pronounced than that of clofibrate. This difference was statistically significantly only in the concentration of plasma triglycerides of type IV patients. It is obvious that the difference between bezafibrate and clofibrate would have been more pronounced if the dose of bezafibrate had been in the optimal range. Serious side-effects caused by bezafibrate could not be observed.     

A T-cell subpopulation committed to help B cells for immune responses restricted to IgM type.

Immune responses againt bovine serum albumin by chicken were dependent upon thymus-derived cells. Thirty-five of seventy chickens that had been neonatally thymectomized and subsequently immunized with bovine serum albumin produced IgM antibodies, but not IgG antibodies, against the antigen. T cells (IgM-T cells) of such chickens were able to help B cells to produce IgM antibody responses but were not able to help them to switch IgM- to IgG-antibody responses. Helper activity of the IgM-T cells was much less susceptible to the cytotoxic effect of anti-thymus cell serum and complement than was that of normal T cells. The introduction of the IgM-T cells into normal chickens at the same time as the initiation of immunization of the chickens did not affect immune responses by them at all, indicating the absence of suppressor T cells in the IgM-T cell preparations. Injection of chicken thymus factor into immunodeficient chickens transplanted with normal B cells and IgM-T cells developed the capability to help B cells to switch IgM- to IgG-antibody responses. On the basis of these findings the authors propose the existence of helper T cells which are characterized by peripheralization in early periods of ontogeny, the possession of helper activity for only IgM-antibody responses, the lack of helper activity for the switch from IgM- to IgG-antibody responses and relative insusceptibility to the cytotoxic effect of anti-thymus cell serum and complement.     

Evidence for viral hepatitis other than type A or type B among persons in Costa Rica.

In studies of hepatitis in an endemic zone in Costa Rica, 103 patients were examined for antibodies against hepatitts A by the immune-adherence assay, for hepatitis B antigen and its antibody by radioimmunoassay and passive hemagglutination, respectively, and for antibodies against cytomegalovirus by complement fixation. Twelve cases were encountered in which both Type A and Type B hepatitis could be excluded on the basis of serologic testing. In all but one of these 12 patients, cytomegalovirus infection was also excluded. The patients had not had blood transfusions and available evidence pointed to person-to-person transmission. The illness in these patients was evidently neither hepatitis A nor hepatitis B and qualifies for consideration as the still hypothetical third type of hepatitis ("C"?).     

iNKT‐cell help to B cells: A cooperative job between innate and adaptive immune responses

T‐cell help to B lymphocytes is one of the most important events in adaptive immune responses in health and disease. It is generally delivered by cognate CD4⁺ T follicular helper (T_FH) cells via both cell‐to‐cell contacts and soluble mediators, and it is essential for both the clonal expansion of antibody (Ab)‐secreting B cells and memory B‐cell formation. CD1d‐restricted invariant natural killer T (iNKT) cells are a subset of innate‐like T lymphocytes that rapidly respond to stimulation with specific lipid antigens (Ags) that are derived from infectious pathogens or stressed host cells. Activated iNKT cells produce a wide range of cytokines and upregulate costimulatory molecules that can promote activation of dendritic cells (DCs), natural killer (NK) cells, and T cells. A decade ago, we discovered that iNKT cells can help B cells to proliferate and to produce IgG Abs in vitro and in vivo. This adjuvant‐like function of Ag‐activated iNKT cells provides a flexible set of helper mechanisms that expand the current paradigm of T‐cell–B‐cell interaction and highlights the potential of iNKT‐cell targeting vaccine formulations.     

Performance and physiological responses of type A and type B individuals during a cognitive and perceptual-motor task

A total of 36 male individuals, 18 classified as Type A and 18 as Type B performed a cognitive (tonal memory) and a perceptual-motor (simulated race car driving) task along with a secondary reaction time (RT) task. Heart rate (HR), skin temperature, and skin conductance (SC) were measured. Multiple linear regression analysis revealed that tracking was related to Jenkins Activity Survey indicating superior performance for those scoring high in overall Type A behavior and low in the H sub-scale (hard driving, competitive behavior). Persons scoring high in the S scale (speed and impatience) and low in the H scale performed better in the short-term memory task. Type A subjects had higher HR and performed better (faster RTs and higher scores) than Type Bs, but only while engaged in the cognitive task. The Type As also had higher SCs than Bs, although they were not differentiated according to task. Sub-scale patterns may have important implications for refining the Type A behavior concept.     

A comparison of methods for quantifying training load: relationships between modelled and actual training responses

Purpose

To assess the validity of methods for quantifying training load, fitness and fatigue in endurance athletes using a mathematical model.

Methods

Seven trained runners ( $\dot{V}$ O₂max: 51.7 ± 4.5 mL kg^?1 min^?1, age: 38.6 ± 9.4 years, mean ± SD) completed 15 weeks of endurance running training. Training sessions were assessed using a heart rate (HR), running pace and rating of perceived exertion (RPE). Training dose was calculated using the session-RPE method, Banisters TRIMP and the running training stress score (rTSS). Weekly running performance (1,500-m time trial), fitness (submaximal HR, resting HR) and fatigue [profile of mood states, heart rate variability (HRV)] were measured. A mathematical model was applied to the training data from each runner to provide individual estimates of performance, fitness and fatigue. Correlations assessed the relationships between the modelled and actual weekly performance, fitness and fatigue measures within each runner.

Results

Training resulted in 5.4 ± 2.6 % improvement in 1,500-m performance. Modelled performance was correlated with actual performance in each subject, with relationships being r = 0.70 ± 0.11, 0.60 ± 0.10 and 0.65 ± 0.13 for the rTSS, session-RPE and TRIMP input methods, respectively. There were moderate correlations between modelled and actual fitness (submaximal HR) for the session-RPE (?0.43 ± 0.37) and TRIMP (?0.48 ± 0.39) methods and moderate-to-large correlations between modelled and actual fatigue measured through HRV indices for both session-RPE (?0.48 ± 0.39) and TRIMP (?0.59 ± 0.31) methods.

Conclusions

These findings showed that each of the training load methods investigated are appropriate for quantifying endurance training dose and that submaximal HR and HRV may be useful for monitoring fitness and fatigue, respectively.     

Ionic currents underlying difference in light response between type A and type B photoreceptors

In Hermissenda crassicornis, the memory of light associated with turbulence is stored as changes in intrinsic and synaptic currents in both type A and type B photoreceptors. These photoreceptor types exhibit qualitatively different responses to light and current injection, and these differences shape the spatiotemporal firing patterns that control behavior. Thus the objective of the study was to identify the mechanisms underlying these differences. The approach was to develop a type B model that reproduced characteristics of type B photoreceptors recorded in vitro, and then to create a type A model by modifying a select number of ionic currents. Comparison of type A models with characteristics of type A photoreceptors recorded in vitro revealed that type A and type B photoreceptors have five main differences, three that have been characterized experimentally and two that constitute hypotheses to be tested with experiments in the future. The three differences between type A and type B photoreceptors previously characterized include the inward rectifier current, the fast sodium current, and conductance of calcium-dependent and transient potassium channels. Two additional changes were required to produce a type A photoreceptor model. The very fast firing frequency observed during the first second after light onset required a faster time constant of activation of the delayed rectifier. The fast spike adaptation required a fast, noninactivating calcium-dependent potassium current. Because these differences between type A and type B photoreceptors have not been confirmed in comparative experiments, they constitute hypotheses to be tested with future experiments.     

Neuroendocrine responses of type A individuals to exercise

Ten Type A and 10 Type B individuals exercised for 20 minutes on a bicycle ergometer at 40%, 60%, and 80% of maximal capacity to determine if differences in neuroendocrine reactivity exist. Pre-exercise plasma concentrations of beta-endorphin and epinephrine were similar for Type As and Type Bs. Pre-exercise plasma levels of norepinephrine tended to be higher for the Type As (p less than 0.07). Post-exercise plasma epinephrine concentrations were similar for As and Bs for all trials. The 40% and 60% trials resulted in no differences in post-exercise norepinephrine and beta-endorphin levels for the Type As and Bs. Conversely, the 80% trials resulted in significantly greater norepinephrine and beta-endorphin concentrations for the Type As (p less than 0.05). Plasma serotonin levels at rest and during exercise were always lower for the Type As (p less than 0.05). These results suggest that our Type As had a greater neuroendocrine response to high-intensity exercise than our Type Bs. The greater reactivity and analgesia may allow the Type A person to suppress feelings of fatigue, thus enduring higher levels of exertion for longer periods of time.     

A comparison of T cell responses to glycoprotein B (gB-1) of herpes simplex virus type 1 and its non-glycosylated precursor protein, pgB-1.

The ability of non-glycosylated precursor glycoprotein B (pgB) to induce T cell responses in herpes simplex virus (HSV) infected mice was compared with fully glycosylated glycoprotein B (gB) and with whole virus. pgB was as effective as gB in priming for virus- and glycoprotein-specific T cells. pgB could also re-stimulate virus or glycoprotein primed cells in vitro as efficiently as gB. In addition, priming with pgB protected mice against a lethal challenge with HSV type 1 (HSV-1) and could induce the early in vivo production of IL-2 and IL-3 in infected mice. In all of these responses, pgB was as effective as gB. Thus, the carbohydrate side chains on gB do not appear to be necessary for T cell recognition of this protein.     

A comparison of similar ionic responses to gamma-aminobutyric acid and acetylcholine

1. Fast Na+-, Cl-, and K+-Conductance increase responses to gamma-aminobutyric acid (GABA) show times to peak similar to the comparable ionic responses to acetylcholine (ACh). 2. On some identified neurons, both putative transmitters elicit responses due to the same conductance change. For example, in cell R2 both substances cause an increase in Cl- conductance. Receptors for GABA and ACh on R2 do not cross desensitize and therefore are distinct. The ACh but not the GABA response is blocked by alpha-bungarotoxin and strychnine. 3. In R2 both responses reverse at -58 mV, and the Cl- ionophore (for both responses) appears to be partially permeant to propionate and isethionate, but impermeant to acetate, sulfate, and methylsulfate. 4. The Cl- responses but not the Na+ responses to both ACh and GABA are blocked by both picrotoxin and bicuculline, the classical GABA antagonists. 5. These results are compatible with the hypothesis that the ionophores associated with receptors to different neurotransmitters but mediating the same ionic conductance change have many common properties and may, in fact, be identical. Bicuculline and picrotoxin may be specific blockers of the Cl- ionophore, not the GABA receptor.     

The comparison of allergic responses to Dermatophagoides farinae between bronchial asthma and allergic rhinitis

The allergic responses of 52 bronchial asthma patients who exhibited a positive bronchoprovocation test with house dust and 50 allergic rhinitis patients who had positive RAST results to Dermatophagoides farinae (D. farinae) were studied, including the measurement of D. farinae-specific IgE using D. farinae-RAST, total IgE and skin reactivity to D. farinae and house dust. A comparison between the allergic rhinitis group in which methacholine PC20 was more than 4.66 mg/mL and the allergic rhinitis group which presented negative results in the methacholine bronchial challenge test, indicated that there were significant differences in skin test reactivity and the ratio of specific IgE to total IgE (P less than .05). The allergic responses we observed were not different between the allergic rhinitis group in which methacholine PC20 was less than 4.66 mg/mL (asthmatic range of methacholine PC20) and the allergic rhinitis group in which methacholine PC20 was more than 4.66 mg/mL. When comparing the bronchial asthma group which showed positive results in D. farinae-RAST and the allergic rhinitis group in which methacholine PC20 was less than 4.66 mg/mL, significant differences were noted in total IgE level (P less than .05). These findings suggest that the development of bronchial asthma in patients with allergic rhinitis might be predicted by measuring the degree of bronchial hyperreactivity and their allergic responses.     

Vestibular-evoked electromyographic responses in soleus: a comparison between click and galvanic stimulation

The aim of this study was to demonstrate, if possible, vestibulospinal reflex responses in soleus using a stimulus known to be capable of exciting vestibular afferents, namely 100-dB (NHL) clicks. We were able to show short-latency electromyographic (EMG) responses after clicks in five of eight normal subjects, and then we compared these responses with those after transmastoid galvanic stimulation (12 normal subjects). Stimulation of the side towards which the head was rotated (i.e. the side facing backwards) with either clicks or the cathode (anode applied to the opposite side) gave an initial excitatory response in soleus, while click or cathodal stimulation of the opposite side (i.e. the side facing forwards) gave an initial inhibitory response. Onset latencies and modulation with changes in postural task were identical for both click- and galvanic-evoked responses. In addition, there was a significant correlation between the amplitudes of the responses in soleus after click and galvanic stimulation (R ²=0.72). These similarities suggest that the earliest reflex responses in soleus after clicks and galvanic stimulation may be mediated by a common central pathway. In contrast, there was no correlation between the amplitudes of responses evoked by 100-dB clicks in soleus and those evoked by the same stimulus in the sternocleidomastoid. We conclude that vestibular activation by clicks can evoke reflex responses in lower-limb muscles and these responses have similar characteristics to the earliest responses evoked by galvanic vestibular stimulation.     

A comparison of four ultraviolet sources to alter graft-versus-host responses

Graft-versus-host disease (GVHD) is a major contributor to the morbidity and mortality associated with allogeneic bone marrow transplantation. Direct ultraviolet B (UVB) irradiation of bone marrow and spleen cell allografts in mice using broadband lamps is known to abolish alloreactive responses which would normally cause GVHD. Using a histoincompatible murine model, we have extended these observations by comparing the physical spectrum of four UV sources (the Philips TUV8W, TL12 and TL01, and the Spectronics XX15B) with in vitro assessment of bone marrow progenitor cell damage and suppression of lymphocyte proliferation and in vivo comparison of the effect on GVHD of the TL12 and XX15B and on the rate of engraftment with the TL12. At doses of uv found to abolish lymphocyte proliferation (2.5, 7, 12 and 1000 J m(-2) with the TUV8W, XX15B, TL12 and TL01 lamps) colony-forming unit granulocyte-macrophage (CFU-GM) proliferation was reduced to 81%, 71%, 79% and 62%, respectively. At an optimal dose found to suppress GVHD (100 J m(-2) integrated radiant energy from 200-320 nm for the TL12 and XX15B) CFU-GM proliferation showed a reduction of 98% with the XX15B and 86% with the TL12. At this radiant energy with the TL12, the rate of bone marrow engraftment was impaired with 72% marrow cellularity at 2 weeks, decreasing to 48% after 200 J m(-2). Our results with this model demonstrate that broadband UVB irradiation of bone marrow permits transplantation across a major histocompatibility barrier. Furthermore we have provided in vitro evidence that narrowband UVB or UVC might potentially be applied to this model.     

Type A and type B behaviour patterns, task type and sensitivity to noise

The present study examined sensitivity to noise in subjects with Type A and Type B behaviour patterns as a function of the type of task being performed. Twenty Type A and 20 Type B subjects, selected by means of Bortner's scale (French version), were exposed to steadily increasing noise levels (68-110 dBA) while performing two tasks. The first was simple (crossing out) and the second was more complex (memorizing nonsense syllables). There was no difference between the groups on the simple task, but on the more complex task Type A and Type B subjects reacted differently, the former maintaining their level of tolerance while the latter lowered theirs. High investment and the desire to succeed may lead Type A subjects to ignore the acoustic environment and/or to deny the aversive aspects of noise as cognitive strategies for coping with stress.     

A comparison of chloramphenicol and ampicillin as bactericidal agents for Haemophilus influenzae type B.

In tests of bactericidal action against H. influenzae type b strains isolated from patients with meningitis, chloramphenicol was found to be far more reliable than ampicillin in dealing with large inocula, and more rapidly effective against both large and relatively small inocula. These findings provide a laboratory explanation for the somewhat better record of chloramphenicol as an agent for treatment of haemophilus meningitis.