Activation levels, EEG, and behavioural responses

Fifteen male alcoholic patients, who were divided into 3 different groups and treated for 3 weeks with placebo, phenobarbital or diazepam, were examined once a week in 3 different states of activation, varying from relaxation to moderate and high demand attention. Frequency-analyzed EEG recording, pulse rate, drug plasma levels, mood and performance were evaluated. The aim of this paper was to find an explanation in the EEG for responding correctly or in a non-adequate way to stimuli. Based on the activation theory of vigilant behaviour, the EEG recordings of the first examination were analyzed before, during and after the presentation of specific stimuli and related to 4 types of responses (hit, miss, false response, correct rejection) to ascertain whether prestimulus patterns were connected with different types of behavioural poststimulus responses. The EEG patterns were found to be dependent on the type of drug administered as well as on the complexity of the task performed. In all 3 treatment groups, low EEG changes before stimulus onset seemed to be the necessary condition for adequate behavioural responses. A high variability between time-points seemed to indicate a subvigilant state which led to non-adequate responses and possibly to internally induced stimuli in the vigilance test to overcome this state. In the stress phase, however, the missed responses were possibly due to selective attention to the simultaneously appearing non-relevant stimuli. The conclusion must be drawn that, at least in alcoholic patients in the acute withdrawal phase, the EEG prior to and during the stimulus presentation plays a decisive role in determining the type of emerging behavioural response: the differential high variability of the EEG is response-specific, whereas the actual power values depend on the medication given and the task performed.     

Association of TNF haplotypes with asthma, serum IgE levels, and correlation with serum TNF-alpha levels

Both biochemical and genetic evidence have implicated the genes for TNF-alpha (TNFA) and lymphotoxin-alpha (LTA) in atopic asthma. Here, we report for the first time the association of their genotypes and haplotypes with atopic asthma in Indian populations. We genotyped seven single nucleotide polymorphisms, encompassing the two genes, in patients and control subjects in two independent cohorts. Serum TNF-alpha levels of selected individuals were measured and correlated with genotypes and haplotypes. The A allele of the TNFA-863C > A polymorphism was associated with reduced risk of asthma (P = 0.002 and 0.007 in Cohorts A and B, respectively), reduced TsIgE levels (P = 0.0024 and P = 0.0029 in Cohorts A and B, respectively), and reduced serum TNF-alpha levels (P < 0.05). A marginal association was also observed for LTA_NcoI polymorphism with asthma and TsIgE levels. Furthermore, analysis using HAPLO. STATS showed significant differences in the major haplotype frequencies (> 3%) between patients and control subjects (P = 0.002 and P = 0.006 for Cohorts A and B, respectively). Individually, the haplotype GATCCG was the most frequent in patients (P = 0.0029 and P = 0.0025 for Cohorts A and B, respectively), and was associated with high TsIgE and serum TNF-alpha levels, whereas AACACG was the most frequent in the control subjects (P = 0.0032 and P = 0.022 for Cohorts A and B, respectively), and was associated with low TsIgE and serum TNF-alpha levels. We also report here that the C > A substitution at position -863 of the TNFA influences the binding of nuclear proteins in electrophoretic mobility shift assay experiments. Thus, the TNFA-863C > A polymorphism in the promoter region of TNFA may influence TNF-alpha expression and affect TsIgE levels and susceptibility to asthma.     

Sleep, brain energy levels, and food intake

Background

The feeling of hunger and feeding, a wake–state-dependent behavior, is regulated by specific centers within the hypothalamus. While paraventricular nucleus (PVN), arcuate nucleus (ARC), and dorso- and ventromedial hypothalamus (DMH/VMH) regulate feeding, the lateral hypothalamus (LH) is associated both with feeding and wake/REM sleep regulation. In order to examine the effects of sleep and wakefulness on food intake and body weight, we also measured hypothalamic ATP concentrations, which are known to be involved in feeding behavior and sleep–wake regulation.

Methods

In rats, food intake and body weight was measured during a 24-h light–dark cycle and during 6 h of sleep deprivation (SD) performed by gentle handling. Tissue samples from the PVN, ARC/DMH/VMH, and LH were collected after 6 h of SD and from time-matched diurnal controls. ATP was measured by luciferin-luciferase bioluminescence assay.

Results

Across the 24-h light–dark period, rats consumed approximately 28.13±4.48 g of food and gained 5.22±1.65 g with a positive correlation between food intake and body weight. During SD, while food intake increased significantly +147.31±6.13%, they lost weight significantly (–93.29±13.64%) when compared to undisturbed controls. SD resulted in a significant decrease in ATP levels only in LH (–44.60±21.13%) with no change in PVN, ARC/DMH/VMH region when compared with undisturbed controls.

Conclusion

The results indicate a strong overall correlation between ATP concentrations in the LH and individual food intake and suggest a sleep–wake dependent neuronal control of food intake and body weight.     

Association between increased levels of TNF-alpha, decreased levels of prealbumin and retinol-binding protein, and disease outcome

We determined whether there is an association between tumor necrosis factor-alpha (TNF-alpha), undernutrition [prealbumin (PA) <160 mg/L, retinol binding protein (RBP) <30 mg/L], disease stage, outcome (death or survival), and race in children with leukemia. TNF-alpha, PA, and RBP were measured in 52 patients (0.8 to 17 years old): 18 African Americans, 34 whites; 27 newly diagnosed (ND), and 25 in clinical remission (CR). Mean levels of TNF-alpha were higher in patients than in 46 healthy children (p < 0.05), but were not different between ND and CR groups. Mean acute phase proteins (APP) were different among groups: ND > CR > controls (p < 0.05). Mean levels of PA and RBP were lower in patients than in controls (p < 0.051, and tended to be higher in CR than in ND patients. African-American patients had lower concentrations of TNF-alpha, PA, and RBP but higher APP than white patients (p < 0.05). CR patients and African-American patients who died tended to have higher levels of TNF-alpha and APP, but lower PA and RBP than those who survived. A higher percentage of ND African Americans (45%) than of ND whites (13%) died. Results suggest that undernutrition and inflammation in CR patients and African Americans were associated with poor survival, and that ND African Americans have a poorer outcome than whites independently of TNF-alpha levels.     

Dominance,plasma testosterone levels,and testis size in house mice artificially selected for high activity levels

Male house mice (Mus domesticus) from four replicate lines selectively bred for high voluntary wheel-running behavior were compared with four random-bred control lines with respect to dominance, testis size, and plasma testosterone level. Behavior was measured with a tube apparatus in which focal mice encountered a standard opponent from an inbred strain, and positions of mice were scored over a 10-min period; the test was replicated the following day. Blood samples were taken from undisturbed mice 1 week prior to testing (baseline condition) and immediately after the first tube test; plasma testosterone was measured by enzyme immunoassay with chromatography. As compared with control lines, mice from selected lines tended to be smaller in body mass, to have larger testes, and were significantly less likely to advance towards their opponent during the second tube-test encounter. However, no significant differences in either baseline or post-encounter testosterone levels were detected. Significant differences in body mass, relative testis size, position during the first tube-test encounter, and baseline testosterone were found among the replicate lines within linetype, which indicates founder effects, random genetic drift, unique mutations, and/or multiple responses to selection. At the level of individual variation (residuals from nested analysis of covariance models), an inverse relationship between baseline testosterone and advancing in the tube test was observed, and the relationship was stronger during the second test day. This unexpected result may reflect an alternate coping strategy.     

Intraduodenal neuropeptide levels,but not plasma levels,vary in a cyclic fashion with the migrating motor complex

The neurohormonal control of the migrating motor complex (MMC) is not fully understood. The hypothesis of the present study was that neuropeptide levels might vary with the different phases of the MMC and that a similar variation might be found in the secretions of the gastrointestinal tract. Thus, plasma and intraduodenal concentrations of vasoactive intestinal peptide (VIP), somatostatin (SOM), substance P (SP) and neurokinin A (NKA) were determined by radioimmunoassay every 10 min during two complete MMC cycles in eight male subjects. For comparison, plasma motilin (MOT) concentrations were measured. Plasma concentrations of MOT (mean peak value ± SEM; 39 ± 6 pmol L^?1), but none of the neuropeptides studied, showed a cyclic variation in plasma with the different phases of the MMC. Peak intraduodenal concentrations of VIP (79 ± 23 pmol L^?1),?SOM (2437 ± 432 pmol L^?1) and SP (718 ± 326 pmol L^?1) occurred at or at the time point before the onset of phase III of the MMC. No such correlation was observed for NKA. These results demonstrate that intraduodenal but not plasma concentrations of the neuropeptides VIP, SOM and SP show an association with phase III of the MMC. The biological relevance of this finding is yet unclear, but the results raise the possibility that gut neuropeptides may regulate fasting motility through a luminal release.     

Cerebrospinal fluid levels of amitriptyline, nortriptyline, imipramine and desmethylimipramine. Relationship to plasma levels and treatment outcome

Fifty-five (55) depressed patients were treated with amitriptyline (AMI) or imipramine (IMI). Concentrations of AMI, IMI, and their metabolites, nortriptyline (NT) and desmethylimipramine (DMI), were measured in cerebrospinal fluid (CSF) and plasma at steady state by gas chromatography mass spectrometry (GC/MS). Highly significant correlations between CSF and plasma levels of AMI, NT, IMI, and DMI were found (r greater than 0.75; P less than 0.0001 in all cases). There were no significant sex, diagnostic subgroup, or geographic difference in any of the drug parameters measured. An evaluation of the relationship between CSF levels of drug variables and clinical response showed essentially no significant correlations between these various parameters. The results obtained do not support the concept of a 'therapeutic window' for levels of plasma NT in AMI-treated patients. Furthermore, the highly significant correlations between CSF and plasma compartments in terms of drug and metabolite levels would argue against the need to measure CSF levels of these parameters in clinical practice. Plasma level measurements should be equally informative, and simpler to obtain.     

Relationship between lipoprotein(a) levels, oxidative stress, and blood pressure levels in patients with essential hypertension

High plasma levels of lipoprotein(a) [Lp(a)] are considered a risk factor for the development of coronary artery disease. In vitro experiments have shown that oxidized Lp(a) is able to impair the arterial endothelium-dependent dilation, thus suggesting a possible role of Lp(a) in the genesis of essential hypertension. The aim of our work was to investigate the correlation of blood pressure levels with plasma Lp(a) concentration, apo(a) isoform size, and peroxidative stress in patients with essential hypertension. The study was performed in 54 untreated hypertensive patients whose blood pressure was monitored for 24 h by ambulatory blood pressure monitoring. Lp(a) concentration was measured by a double monoclonal antibody-based enzyme immunoassay demonstrated to be insensitive to apo(a) size heterogeneity. Apo(a) isoforms were determined by a high-resolution SDS-agarose gel electrophoresis followed by immunoblotting. A significant correlation was found between Lp(a) levels and the night-time systolic and diastolic pressures (r=0.32, P<0.05, and r=0.30, P<0.05, respectively), as well as with the mean night-time fall in systolic and diastolic blood pressures (r=0.28, P<0.05 and r=0.29, P<0.05, respectively). These relationships were further potentiated when peroxidative stress data were taken into consideration (r=0.37 and r=0.40, P<0.01 for the night-time systolic and diastolic pressures, respectively and r=0.34 and r=0.38, P<0.01 for the night-time fall in systolic and distolic blood pressures, respectively). Apo(a) isoform size did not affect these relationships. Our data suggest that Lp(a) and peroxidative stress may be involved as cofactors in essential hypertension, with a mechanism that remains to be elucidated. Received: 16 July 2001 / Accepted: 15 September 2001     

Design of carcinogenicity studies, dose selection, route, blood levels, transformation

The results of subacute toxicity tests are the information most commonly used for setting doses for carcinogenicity studies. However, since diet composition is important in regard to tumor incidence, knowledge of the effect of various doses of the compound on the nutritional composition and quality of the diet of the animals on test is also important. It is also important to determine if any of the doses administered in the study exceed the ability of the species under study to excrete it in a manner which is approximately the same as that seen at lower doses. Similarly, it is important to determine if the higher doses administered lead to the formation of metabolites not seen at lower doses which are more nearly equivalent to those to which humans are or will be exposed. The compound under test should, if possible, be administered by the same route by which human exposure occurs or is anticipated to occur. Because of potential difficulties in the interpretation of the results, gastric intubation is, in general, the least desirable method of administration. In selecting the most appropriate animal species to be used in a carcinogenicity study, consideration should be given to the use of the species and strain of experimental animal that is most biologically and metabolically similar to humans, if such data are available.     

The perceptive,mnemic, and semantic levels of subjective representation

Three levels of the representation of signals are reviewed in this article: the immediate (perceptive) level, the level of preservation of traces (the mnemic), and the level of symbolic representation (semantic). Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 43, No. 2, pp. 228–231, March–April, 1993.     

Sleep quality,cortisol levels,and behavioral regulation in toddlers

This study examines the association between nighttime sleep characteristics and cortisol levels and how these variables relate to aspects of children's temperament and behavior. Twenty‐seven healthy children, aged 12–36 months, attending group childcare settings, participated in the study. Each child's sleep was measured at home with actigraphy over three nights. Saliva samples were collected by the mothers at bedtime and within 30 min of awakening. In addition, both the mother and the daycare teacher rated the child's behavioral difficulties and negative emotionality. It was found that children with more fragmented sleep displayed higher awakening cortisol levels compared to children with more efficient sleep. Moreover, elevated awakening cortisol levels were correlated with teachers' ratings of internalizing behavior and negative emotionality. These preliminary findings suggest that awakening cortisol may serve as a useful index of adrenocortical reactivity in young children, signaling a disturbance in physiological regulation, and underscore the need for more research pertaining to the dynamic associations between sleep and HPA‐axis across the 24‐hr period. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52: 44–53, 2010     

Salivary cortisol and DHEA levels in the Korean population: age-related differences, diurnal rhythm, and correlations with serum levels

PURPOSE: The primary objective of this study was to examine the changes of basal cortisol and DHEA levels present in saliva and serum with age, and to determine the correlation coefficients of steroid concentrations between saliva and serum. The secondary objective was to obtain a standard diurnal rhythm of salivary cortisol and DHEA in the Korean population. MATERIALS AND METHODS: For the first objective, saliva and blood samples were collected between 10 and 11 AM from 359 volunteers ranging from 21 to 69 years old (167 men and 192 women). For the second objective, four saliva samples (post-awakening, 11 AM, 4 PM, and bedtime) were collected throughout a day from 78 volunteers (42 women and 36 men) ranging from 20 to 40 years old. Cortisol and DHEA levels were measured using a radioimmunoassay (RIA). RESULTS: The morning cortisol and DHEA levels, and the age- related steroid decline patterns were similar in both genders. Serum cortisol levels significantly decreased around forty years of age (p < 0.001, when compared with people in their 20s), and linear regression analysis with age showed a significant declining pattern (slope=-2.29, t=-4.297, p < 0.001). However, salivary cortisol levels did not change significantly with age, but showed a tendency towards decline (slope=-0.0078, t=-0.389, p=0.697). The relative cortisol ratio of serum to saliva was 3.4-4.5% and the ratio increased with age (slope=0.051, t=3.61, p < 0.001). DHEA levels also declined with age in saliva (slope=-0.007, t=-3.76, p < 0.001) and serum (slope=-0.197 t=-4.88, p < 0.001). In particular, DHEA levels in saliva and serum did not start to significantly decrease until ages in the 40s, but then decreased significantly further at ages in the 50s (p < 0.001, when compared with the 40s age group) and 60s (p < 0.001, when compared with the 50 age group). The relative DHEA ratio of serum to saliva was similar throughout the ages examined (slop=0.0016, t=0.344, p=0.73). On the other hand, cortisol and DHEA levels in saliva reflected well those in serum (r=0.59 and 0.86, respectively, p < 0.001). The highest salivary cortisol levels appeared just after awakening (about two fold higher than the 11 AM level), decreased throughout the day, and reached the lowest levels at bedtime (p < 0.001, when compared with PM cortisol levels). The highest salivary DHEA levels also appeared after awakening (about 1.5 fold higher than the 11 AM level) and decreased by 11 AM (p < 0.001). DHEA levels did not decrease further until bedtime (p=0.11, when compared with PM DHEA levels). CONCLUSION: This study showed that cortisol and DHEA levels change with age and that the negative slope of DHEA was steeper than that of cortisol in saliva and serum. As the cortisol and DHEA levels in saliva reflected those in serum, the measurement of steroid levels in saliva provide a useful and practical tool to evaluate adrenal functions, which are essential for clinical diagnosis.     

Low levels of estradiol facilitate,whereas high levels of estradiol impair,working memory performance on the radial arm maze

Previous investigations of estradiol's effects on learning and memory yielded equivocal results. This study was designed to determine whether these inconsistencies were due to dose-dependent effects of estradiol on different memory processes. Ovariectomized female rats were injected daily with estradiol benzoate (EB; 0.32, 1.00, or 5.00 microg) or vehicle. Approximately 3 hr after injection, rats were run on a hippocampus-dependent working/reference memory version of the radial arm maze. Total number of working (WME), reference, and combined working/reference memory errors were scored. Compared with vehicle, 1.00 or 5.00 microg EB (high physiological) impaired performance by increasing the number of WME, whereas 0.32 microg EB (low physiological) facilitated performance by decreasing the number of WME. Taken together, these data demonstrate a dose-dependent effect of EB on working memory.     

Lactoferrin,lysozyme, and β2-Microglobulin levels in cerebrospinal fluid

The CSF levels of lactoferrin, lysozyme, and ₂-microglobulin ( ₂ ) were measured in patients with evident, probable, or possible inflammatory CNS reactions and compared to those found in neurologically apparently healthy patients. Patients with viral CNS infections had significantly raised ₂ and lysozyme levels but normal lactoferrin levels, indicating a local activation of lymphocytes and monocytes but not of granulocytes. Patients with bacterial CNS infections had significantly raised levels of all three cell markers, but the increase of lysozyme and lactoferrin was relatively more pronounced than that of ₂ , indicating that the inflammatory response to bacterial agents is dominated by monocytes and granulocytes. Patients with primary or secondary malignant brain tumors were characterized by a moderate increase of ₂ and a considerable increase in both lysozyme and lactoferrin, i.e., the same protein pattern as observed in bacterial CNS infection. The lysozyme levels were moderately increased in half the patients with benign cerebral tumors while the levels of ₂ and lactoferrin were normal, indicating that benign and malignant brain tumors induce different local inflammatory CNS reactions. Half the patients with pituitary gland adenoma had elevated ₂ and lysozyme levels but normal lactoferrin levels, suggesting that immunological mechanisms are associated with the adenoma development. Patients with MS had moderately but significantly raised CSF levels of ₂ and lysozyme and a third of them also had raised levels of lactoferrin, a protein pattern suggesting a low-active inflammatory process in CNS involving mononuclears and granulocytes. A similar protein pattern was found in Guillain-Barré syndrome. In cerebrosarcoidosis we noted considerably increased lysozyme and ₂ but normal lactoferrin levels, consistent with the idea that the sarcoid granuloma mass is dominated by monocytic inflammatory cells. The data obtained indicate a clinical value of lactoferrin, lysozyme, and ₂ as differential indices of inflammatory cell reactions taking place in various CNS processes.     

Aging and serum immunoglobulin E levels, immediate skin tests, RAST

The changes of the serum IgE levels, specific immediate skin-test responses, and RAST measurements with age were evaluated. A total of 331 unrelated individuals were studied, consisting of 166 subjects with ragweed allergic rhinitis and/or asthma, 67 with idiopathic (intrinsic) asthma, and 98 who appeared in good health with no clinical evidence of atopic diseases. All subjects were evaluated by history and physical examination, intradermal skin testing to the common aeroallergens, measurements of IgE antibody to common aeroallergens with the RAST, and serum IgE levels. Results demonstrated a significant decrease in serum IgE levels with aging in atopic individuals. This decline was exponential in character. In addition, a tendency for RAST and immediate type skin-test responses for selected antigens and histamine to decrease with age was observed.